JP2006268033A - Optical compensation sheet, polarizing plate, and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical compensation sheet capable of maintaining images of high quality even after long-time illumination at high humidity, a polarizing plate equipped with the optical compensation sheet, and a liquid crystal display device. <P>SOLUTION: An optical anisotropic layer containing at least one liquid crystal compound is formed on a stretched polymer film and the retardation satisfies inequalities (A) to (F). Here, (A) 30 nm<Rd(546)<150 nm, (B) 100 nm<Rth(546)<400 nm, (C) 0.5<Re(480)/Re(546)<1, (D) 1.0<Re(628)/Re(546)<2.0, (E) 1.0<Rth(480)/Rth(546)<1.5, and (F) 0.7<Rth(628)/Rth(546)<1.0 (where Re(λ) and Rth(λ) represent in-surface retardation and thickness-directional retardation (nm) at a wavelength λ). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical compensation sheet, a polarizing plate, and a liquid crystal display device.

Liquid crystal display devices are increasingly used year by year as space-saving image display devices with low power consumption. Conventionally, the large viewing angle dependency of an image has been a major drawback of a liquid crystal display device. However, in recent years, a high viewing angle liquid crystal mode of the VA mode has been put into practical use. In demanded markets, the demand for liquid crystal display devices is rapidly expanding.
Accordingly, in the liquid crystal display device, further improvement in the optical compensation capability is demanded for the optical compensation member used for improving the hue, contrast, and viewing angle dependency thereof.
As an optical compensation film for a VA mode liquid crystal display device, a combination of an A plate and a C plate is known to have a particularly high effect of improving the contrast viewing angle.
Furthermore, Patent Document 1 discloses a technique for further improving the contrast and bringing the color in black display closer to gray by performing optical compensation with a polymer film having different wavelength dispersion of in-plane retardation and thickness direction retardation. Has been.
However, the effect of improving the color viewing angle is insufficient with this method, and particularly when displayed for a long time under high temperature and high humidity, there is a problem that the color change becomes large, and improvement has been demanded. .
WO2004 / 068226 A1

An object of the present invention is to provide an optical compensation sheet that can maintain a high-quality image even when lit for a long time under high humidity.
Still another object of the present invention is to provide a polarizing plate and a liquid crystal display device provided with the optical compensation sheet.

  As a result of intensive studies, the present inventors have found that the color change is caused by a wavelength dispersion change. That is, the polymer disclosed in Patent Document 1 is different in the wavelength dispersion of the polarizability anisotropy of the main chain and the wavelength dispersion of the polarizability anisotropy of the side chain. Different wavelength dispersion is realized by retardation in the thickness direction. However, the photoelastic coefficient is inevitably increased, and as a result, there is an adverse effect that a change in retardation is increased when stress is generated in the film. In particular, when the liquid crystal display device is lit for a long time under high humidity, it is serious because a large stress is generated in the optical compensation sheet as the polyvinyl alcohol of the polarizer contracts.

  Instead, the present inventors provide retardation of retardation by providing an optical anisotropy in which a liquid crystalline compound is oriented perpendicular to the stretching direction on a film obtained by stretching a polymer composed of a monomer component having a small intrinsic birefringence. It has been found that a liquid crystal display device can be realized that can realize ideal wavelength dispersion characteristics and has little color change even when lit at a high temperature and high humidity for a long time, and has completed the present invention.

1) An optical compensation sheet having an optically anisotropic layer containing at least one liquid crystal compound on a stretched polymer film, wherein the retardation satisfies the following relationships (A) to (F).
30 nm <Re (546) <150 nm (A)
100 nm <Rth (546) <400 nm (B)
0.5 <Re (480) / Re (546) <1 (C)
1.0 <Re (628) / Re (546) <2.0 (D)
1.0 <Rth (480) / Rth (546) <1.5 (E)
0.7 <Rth (628) / Rth (546) <1.0 (F)
(However, Re (λ) is the in-plane retardation (nm) at wavelength λ, and Rth (λ) is the thickness direction retardation (nm) at wavelength λ).
2) The optical compensation sheet as described in 1) above, wherein the slow axis of the stretched polymer film and the slow axis of the optically anisotropic layer containing the liquid crystal compound are perpendicular to each other.
3) The optical compensation sheet according to 1) or 2), wherein the retardation of the stretched polymer film satisfies the following formulas (G) to (J).
0.95 <Re (480) / Re (546) <1.05 (G)
0.95 <Re (628) / Re (546) <1.05 (H)
0.95 <Rth (480) / Rth (546) <1.05 (I)
0.95 <Rth (628) / Re (546) <1.05 (J)
(However, Re (λ) is the in-plane retardation (nm) at wavelength λ, and Rth (λ) is the thickness direction retardation (nm) at wavelength λ).
4) The optical compensation sheet according to any one of 1) to 3) above, wherein the retardation of the optically anisotropic layer satisfies the following formulas (K) to (N).
1.0 <Re (480) / Re (546) <2.0 (K)
0.5 <Re (628) / Re (546) <1.0 (L)
1.0 <Rth (480) / Rth (546) <2.0 (M)
0.5 <Rth (628) / Rth (546) <1.0 (N)
(However, Re (λ) is the in-plane retardation (nm) at wavelength λ, and Rth (λ) is the thickness direction retardation (nm) at wavelength λ).
5) The stretched polymer film has a photoelastic coefficient of 5 × 10 ⁻¹³ cm ² / dyn (5 × 10 ⁻⁸ cm ² / N) or less, according to any one of 1) to 4) above Optical compensation sheet.
6) The optical compensation sheet according to any one of 1) to 5) above, wherein the stretched polymer film is a cycloolefin polymer film.
7) A polarizing plate comprising a polarizer and two protective films disposed on both sides thereof, wherein at least one protective film is the optical compensation sheet according to any one of 1) to 6) above. A characteristic polarizing plate.
8) A liquid crystal display device having a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein at least one polarizing plate is the polarizing plate described in 7) above.
9) The liquid crystal display device as described in 8) above, wherein the liquid crystal cell is in a VA mode.

  According to the optical compensation sheet of the present invention, it is possible to obtain a liquid crystal display device with little color change even when lit for a long time.

<Stretched polymer film>
First, the stretched polymer film of the present invention (hereinafter also referred to as a specific retardation film) will be described.
<Polymer material>
In the present invention, the polymer used for forming the stretched polymer film is preferably a polymer having a small intrinsic birefringence and a small photoelastic coefficient.
The photoelastic coefficient is preferably 5 × 10 ⁻⁸ cm ² / N or less, more preferably 3 × 10 ⁻⁸ cm ² / N or less.
Among the polymers satisfying the above, a cycloolefin polymer film is particularly preferable.

The cycloolefin polymer preferably used in the present invention is described in detail below.
<Cycloolefin polymer film>
(Cycloolefin-based addition polymer)
In the present invention, the cycloolefin-based polymer used for forming the stretched polymer film is suitable for the structural unit (a) represented by the following general formula (1) and the structural unit (b) represented by the following general formula (2). The cyclic olefin addition polymer contained in a ratio of
General formula (1)

[A ₁ , A ₂ , A ₃ and A _{4 in the} general formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. Is an atom. A _{1 to} A ₄ also include an alkylene group formed from A ₁ and A ₂ , A ₁ and A _3, or A ₂ and A ₄ . r represents an integer of 0-2.

Such a structural unit (a) is formed by addition polymerization of a cyclic olefin compound represented by the following general formula (3) (hereinafter referred to as “specific monomer (A)”).
General formula (3)

[A ₁ , A ₂ , A ₃ and A _{4 in the} general formula (3) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group having 4 to 15 carbon atoms, or a halogen atom. Is an atom. A _{1 to} A ₄ also include an alkylene group and an alkylidene group formed from A ₁ and A ₂ , A ₁ and A _3, or A ₂ and A ₄ . r represents an integer of 0-2. ]

  Specific examples of the “specific monomer (A)” represented by the formula (3) include bicyclo [2.2.1] hept-2-ene and 5-methyl-bicyclo [2.2.1]. Hept-2-ene, 5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-propyl-bicyclo [2.2.1] hept-2-ene, 5-butyl-bicyclo [2. 2.1] Hept-2-ene, 5-pentyl-bicyclo [2.2.1] hept-2-ene, 5-hexyl-bicyclo [2.2.1] hept-2-ene, 5-heptyl- Bicyclo [2.2.1] hept-2-ene, 5-octyl-bicyclo [2.2.1] hept-2-ene, 5-decyl-bicyclo [2.2.1] hept-2-ene, 5-dodecyl-bicyclo [2.2.1] hept-2-ene, 5,6-dimethyl-bicyclo [2.2. ] Hept-2-ene, 5-methyl-5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-phenyl-bicyclo [2.2.1] hept-2-ene, 5-cyclohexyl -Bicyclo [2.2.1] hept-2-ene, 5-cyclooctyl-bicyclo [2.2.1] hept-2-ene, 5-fluoro-bicyclo [2.2.1] hept-2-ene Ene, 5-chloro-bicyclo [2.2.1] hept-2-ene, tricyclo [4.2.015,8] non-2-ene, 1-methyltricyclo [4.2.0. 15,8] nona-2-ene, 6-methyltricyclo [4.2.0.15,8] nona-2-ene, tricyclo [5.2.1.02,6] dec-8-ene, 3-methyltricyclo [5.2.1.02,6] dec-8-ene, 4-methyltricyclo [ .2.1.02,6] dec-8-ene, tricyclo [6.2.1.02,7] undec-9-ene, 1-methyltricyclo [6.2.1.02,7] undeca -9-ene, 3-methyltricyclo [6.2.1.02,7] undec-9-ene, 1-ethyltricyclo [6.2.1.02,7] undec-9-ene, 3 -Ethyltricyclo [6.2.1.02,7] undec-9-ene, tricyclo [8.2.1.02,9] tridec-11-ene, 1-methyltricyclo [8.2.1 .02,9] tridec-11-ene, 5-methyltricyclo [8.2.1.02,9] tridec-11-ene, tetracyclo [4.4.0.12,5.17,10] dodeca -3-ene, 8-methyl-tetracyclo [4.4.0.12,517,10] dodeca- 3-ene, 8-ethyl-tetracyclo [4.4.0.12,517,10] dodec-3-ene, and the like.

  Also, 5-vinyl-bicyclo [2.2.1] hept-2-ene, 5- (1-butenyl) -bicyclo [2.2.1] hept-2-ene, tricyclo [5.2.1. 02,6] deca-3,8-diene, 1-methyltricyclo [5.2.1.02,6] deca-3,8-diene, 1-ethyltricyclo [5.2.1.02, 6] Addition polymerization of a cyclic diolefin compound such as deca-3,8-diene, and then hydrogenate the cyclic olefinically unsaturated bond present in the side chain, so that the structural unit (a) can be obtained. Good.

  Among these “specific monomers (A)”, preferred are bicyclo [2.2.1] hept-2-ene or tricyclo [5.2.1.02,6] dec-8-ene. is there. In tricyclo [5.2.1.02,6] dec-8-ene, there are endo and exo stereoisomers, but in the present invention, the endo isomer is the final one. Therefore, it is preferable to use tricyclo [5.2.1.02,6] dec-8-ene having an endo content of at least 80%. Also, there is a method in which addition-polymerization is performed using endo-form tricyclo [5.2.1.02,6] deca-3,8-diene, and the cyclic olefinically unsaturated bond remaining in the rear side chain is hydrogenated. Likewise preferred. Even in this case, the endo-form content is preferably 80% or more. The cyclic olefin polymer obtained by using these is not only excellent in transparency and heat resistance, but also becomes a polymer having low water absorption, low dielectric property, and high toughness. The “specific monomer (A)” can be used alone or in combination of two or more.

The structural unit (b) represented by the following general formula (2) is an addition polymerization of a cyclic olefin represented by the following general formula (4) (hereinafter referred to as “specific monomer (B)”). Is formed.
General formula (2)

[In General Formula (2), B _{1 to} B ₄ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a halogenated alkyl group, a hydrolyzable silyl group, or — (CH ₂ ). _j represents a polar group represented by X, and at least one of B _{1 to} B ₄ includes a hydrolyzable silyl group or a polar group represented by — (CH ₂ ) _j X. Here, X is —C (O) OR ₁ or —OC (O) R ₂ , and R ₁ and R ₂ are alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups having 1 to 10 carbon atoms, or those A substituent selected from the group consisting of halogen substituents, j is an integer of 0-3. B _{1 to} B ₄ also include an alkylene group formed from B ₁ and B ₃ or B ₂ and B ₄ , and an alkylidenyl group formed from B ₁ and B ₂ or B ₃ and B ₄ . p shows the integer of 0-2.
General formula (4)

[In General Formula (4), B _{1 to} B ₄ are the same as in General Formula (2). p shows the integer of 0-2. ]

  Specific examples of such “specific monomer (B)” include, for example, the following compounds, but the present invention is not limited to these specific examples. 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-butoxycarbonyl-bicyclo [2.2.1] ] Hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-ethoxycarbonyl-bicyclo [2.2.1] hept-2 -Ene, 5-methyl-5-propoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-butoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5 -Ethyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-methyl-5-trifluoromethoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5-me Ru-bicyclo [2.2.1] hept-2-en-5-ylmethylcarboxylate, acrylate-1-methyl-bicyclo [2.2.1] hept-3-ene, methacrylic acid-1- Methyl-bicyclo [2.2.1] hept-3-ene, 5,6-di (methoxycarbonyl) -bicyclo [2.2.1] hept-2-ene, 5,6-di (methoxycarbonyl)- Bicyclo [2.2.1] hept-2-ene, 8-methyl-8-methoxycarbonyl-tetracyclo [4.4.0.12,5.17,10] dodec-3-ene, 8-methyl-8 -Ethoxycarbonyl-tetracyclo [4.4.0.12,5.17,10] dodec-3-ene, 5-trimethoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxychloro Silyl-bicyclo [2. .1] hept-2-ene, 5-methoxychloromethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxychlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-methoxyhydridomethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-dimethoxyhydridosilyl-bicyclo [2.2.1] hept-2-ene, 5-methoxydimethylsilyl-bicyclo [2] 2.1] hept-2-ene, 5-triethoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-diethoxychlorosilyl-bicyclo [2.2.1] hept-2- Ene, 5-ethoxychloromethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-diethoxyhydridosilyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxydimethyl Tylsilyl-bicyclo [2.2.1] hept-2-ene, 5-ethoxydiethylsilyl-bicyclo [2.2.1] hept-2-ene, 5-propoxydimethylsilyl-bicyclo [2.2.1] Hept-2-ene, 5-tripropoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-triphenoxysilyl-bicyclo [2.2.1] hept-2-ene, 5-trimethoxy Silylmethyl-bicyclo [2.2.1] hept-2-ene, 5-dimethylchlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-methyldichlorosilyl-bicyclo [2.2.1] ] Hept-2-ene, 5-trichlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-diethylchlorosilyl-bicyclo [2.2.1] hept-2-ene, 5-ethyldic Rosilyl-bicyclo [2.2.1] hept-2-ene, 5- (2-trimethoxysilyl) ethyl-bicyclo [2.2.1] hept-2-ene, 5- (2-dimethoxychlorosilyl) Ethyl-bicyclo [2.2.1] hept-2-ene, 5- (1-trimethoxysilyl) ethyl-bicyclo [2.2.1] hept-2-ene, 5- (2-trimethoxysilyl) Propyl-bicyclo [2.2.1] hept-2-ene, 5- (1-trimethoxysilyl) propyl-bicyclo [2.2.1] hept-2-ene, 5-triethoxysilylethyl-bicyclo [ 2.2.1] Hept-2-ene, 5-dimethoxymethylsilylmethyl-bicyclo [2.2.1] hept-2-ene, 5-trimethoxypropylsilyl-bicyclo [2.2.1] hept- 2-ene, -Methyl-5- (3-triethoxysilyl) propoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 8-triethoxysilyl-tetracyclo [4.4.0.12, 5.17,10 ] Dodec-3-ene, 8-methyldimethoxysilyl-tetracyclo [4.4.0.12, 5.17,10] dodec-3-ene,

5- [1′-methyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 3 ′ , 4 ′, 4′-tetraphenyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 3 ′, 4 ′, 4′-tetramethyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-phenyl-2 ', 5'-dioxa-1'-silacyclopentyl] -bicyclo [2.2.1] hept-2-ene, 5- [1'-ethyl-2', 5'-dioxa-1'-silacyclopentyl] -Bicyclo [2.2.1] hept-2-ene, 5- [1 ', 3'-dimethyl-2', 5'-dioxa-1'-silacyclopentyl] -bi Chlo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 4′-dimethyl-2 ′, 5′-dioxa-1′-silacyclopentyl] -bicyclo [2.2 .1] Hept-2-ene, 5- [1′-methyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1 '-Ethyl-2', 6'-dioxa-1'-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1 ', 3'-dimethyl-2', 6'- Dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′- Silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1 ′ Silacyclohexyl] methyl-bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-4 ′, 4′-dimethyl-2 ′, 6′-dioxa-1′-silacyclohexyl] ethyl -Bicyclo [2.2.1] hept-2-ene, 5- [1'-phenyl-4 ', 4'-dimethyl-2', 6'-dioxa-1'-silacyclohexyl] -bicyclo [2. 2.1] hept-2-ene, 5- [1′-methyl-4′-phenyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2- Ene, 5- [1′-methyl-4′-spiro-cyclohexyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1 '-Methyl-4'-ethyl-4'-butyl-2', 6'-dioxa-1'-silacyclohexyl] Bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3 ′, 3′-dimethyl-5′methylene-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-phenyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl-3′-phenyl-2 ′, 6′-dioxa-1′-silacyclohexyl] -bicyclo [2.2.1] hept-2-ene, 5- [1′-methyl- 4 ', 4'-dimethyl-2', 6'-dioxa-1'-silacyclohexyl] -7-oxa-bicyclo [2.2.1] hept-2-ene, 5- [1'-methyl-2 ', 6'-dioxa-1'-silacyclohexyl] -7-oxa-bicyclo [2.2.1] hept-2-ene, 5- [1' Methyl-2 ′, 7′-dioxa-1′-silacycloheptyl] -bicyclo [2.2.1] hept-2-ene, 8- [1′-methyl-4 ′, 4′-dimethyl-2 ′ , 6′-dioxa-1′-silacyclohexyl] -tetracyclo [4.4.0.12,517,10] dodec-3-ene, 8- [1′-methyl-2 ′, 6′-dioxa-1 '-Silacyclohexyl] -tetracyclo [4.4.0.12,517,10] dodec-3-ene, 8-methyl-8-carboxymethyl-9-carboxymethyltetracyclo [4.4.0.12, 5. 17, 10] -3-dodecene, and the like. These “specific monomers (B)” can be used alone or in combination of two or more.

  The proportion of the structural unit (b) contained in the cyclic olefin polymer is 5 to 95 mol%, preferably 10 to 90 mol%, more preferably 20 to 80 mol% in all the structural units. If the proportion of the structural unit (b) of the cyclic olefin polymer is too small, the adhesion / adhesion with the polyvinyl alcohol used in the polarizer may be poor. On the other hand, when the ratio is too large, the hygroscopicity is increased and the dimensional stability is inferior. The arrangement of the structural units (b) is not limited in the cyclic olefin polymer, such as random or block, but is preferably random. Furthermore, the cyclic olefin addition polymer containing the structural unit (b) having a reactive substituent such as a hydrolyzable silyl group, an ester group, an acryloyl group, or a methacryloyl group as a side chain substituent uses a crosslinking agent described later. Thus, a film of a cyclic olefin polymer can be made into a crosslinked product.

  A structural unit (c) obtained by addition polymerization of a “specific α-olefin compound” can be further introduced into the cyclic olefin polymer used in the present invention.

  Specific examples of such a “specific α-olefin compound” include ethylene, propylene, 1-butene, 1-hexene, 1-octene, trimethylsilylethylene, triethylsilylethylene, styrene, and the like, preferably ethylene. is there.

  By introducing the repeating unit (c) derived from the “specific α-olefin compound” into the polymer, the glass transition temperature of the cyclic olefin polymer can be controlled. The ratio of the repeating unit (c) contained in the cyclic olefin polymer used in the present invention is 0 to 30 mol%, preferably 0 to 20 mol%. In addition, when the ratio of a repeating unit (c) exceeds 30 mol%, the glass transition temperature of a cyclic olefin type polymer will become low at 170 degrees C or less, and heat resistance may fall and it is unpreferable.

The molecular weight of the cyclic olefin polymer used in the present invention is expressed in terms of polystyrene, the number average molecular weight is 10,000 to 300,000, the weight average molecular weight is 20,000 to 700,000, preferably the number average molecular weight. The average molecular weight is 20,000 to 200,000, the weight average molecular weight is 50,000 to 500,000, more preferably the number average molecular weight is 50,000 to 150,000, and the weight average molecular weight is 100,000 to 300,000. When the number average molecular weight is less than 10,000 and the weight average molecular weight is less than 20,000, the film may be inferior in toughness and easily cracked. On the other hand, when the number average molecular weight exceeds 300,000 and the weight average molecular weight exceeds 700,000, the solution viscosity increases, and the workability of film formation by the solution casting method, the surface of the obtained film, and the like may be deteriorated. .
The glass transition temperature of the cyclic olefin polymer used in the present invention is 180 to 450 ° C., preferably 200 to 400 ° C. in an uncrosslinked state. When the glass transition temperature of the polymer is less than 180 ° C., the heat resistance is insufficient. On the other hand, when it exceeds 450 ° C., the film may not be tough and may be easily broken.

  The cyclic olefin-based polymer used in the present invention mainly uses “specific monomer (A)” and, if necessary, “specific monomer (B)” for crosslinking formation or adhesion / adhesion imparting. And a “specific α-olefin compound” for controlling the glass transition temperature as necessary. Hereinafter, the manufacturing method will be described.

  Examples of the polymerization catalyst include single complex catalysts and multi-component catalysts such as palladium, nickel, cobalt, titanium and zircon listed in the following [1], [2] and [3]. It is not limited.

[1] Single complex catalyst such as Pd, Ni [Pd (CH ₃ CN) ₄ ] [BF ₄ ] ₂ , [Pd (PhCN) ₄ ] [SbF ₆ ], [(η ³ -crotyl) Pd (cycloocta Diene)] [PF ₆ ], [(η ³ -crotyl) Ni (cycloocta-1,5-diene)] [B (3,5- (CF ₃ ) ₂ C ₆ F ₃ ) ₄ ], [(η ³ -Crotyl) Ni (cycloclota-1,5-diene)] [PF ₆ ], [(η ³ -allyl) Ni (cycloclota-1,5-diene)] [B (C ₆ F ₅ ) ₄ ], [( ^{η 3 -crotyl) Ni (cycloocta-} 1,5-diene)] [SbF 6], Toluene · Ni (C 6 F 5) 2, Benzene · Ni (C 6 F 5) 2, mesitylene · Ni (C 6 F ₅ ) ₂ Ethylet her ・ Ni (C ₆ F ₅ ) ₂

[2] Multi-component catalyst di- [mu] -chloro-bis (6-methoxybicyclo [2.2.1] hept-2- by combination of palladium complex having [sigma] or [sigma], [pi] bond and organoaluminum or super strong acid salt A combination of ene-endo-5σ, 2π) Pd and a compound selected from methylalumoxane (abbreviated as MAO), AgSbF ₆ , and AgBF ₄ . A combination of [(η ³ -aryl) PdCl] ₂ and AgSbF ₆ or AgBF ₄ . A combination of [(1,5-cyclooctadiene) Pd (CH ₃ ) Cl], PPh ₃ and NaB [3,5- (CF ₃ ) ₂ C ₆ H ₃ ] ₄ . The combination of etc. is mentioned.

  [3] 1) transition metal compounds selected from nickel compounds, cobalt compounds, titanium compounds or zircon compounds, 2) compounds selected from superacids, Lewis acids and ionic boron compounds, and 3) A multi-component catalyst containing an organoaluminum compound.

1) Transition metal compound 1) -1 Nickel compound, cobalt compound: at least one compound selected from the following group, organic carboxylate of nickel or cobalt, organic phosphite, organic phosphate, organic A compound selected from sulfonates, β-diketone compounds and the like. For example, nickel 2-ethylhexanoate, nickel naphthenate, cobalt naphthenate, nickel oleate, nickel dodecanoate, cobalt dodecanoate, cobalt neodecanoate, nickel dodecylbenzenesulfonate, bis (acetylacetonato) nickel, bis (ethyl Acetoacetate) nickel etc. A compound obtained by modifying the above organic carboxylate of nickel with a super strong acid such as hexafluoroantimonic acid, tetrafluoroboric acid, trifluoroacetic acid, hexafluoroacetone, or the like, a nickel diene or triene coordination complex, for example, Dichloro (1,5-cyclooctadiene) nickel, [(η ³ -crotyl) (1,5-cyclooctadiene) nickel] hexafluorophosphate, and its tetrafluoroborate, tetrakis [3,5-bis (trifluoro) Methyl)] borate complex, 5,9-cyclododecatriene) nickel, bis (norbornadiene) nickel, nickel complex such as bis (1,5-cyclooctadiene) nickel, nickel has atoms such as P, N, O Ligand coordinated complexes, for example bis (triphenylphosphine) nickel dichloro Bis (triphenylphosphine) nickel dibromide, bis (triphenylphosphine) cobalt dibromide, bis [N- (3-t-butylsalicylidene) phenylaminate] nickel, Ni [PhC (O) CH] (Ph), Ni (OC ( C 6 H 4) PPh) (H) (PCy 3), Ni [OC (O) (C 6 H 4) P] (H) (PPh 3), bis (1,5 Reaction product of cyclooctadiene) nickel and PhC (O) CH═PPh ₃ , 6- (i-Pr) ₂ C ₆ H ₃ N═CHC ₆ H ₃ (O) (Anth)] (Ph) (PPh ₃ ) Nickel complexes such as Ni (where Anth is 9-anthracenyl, Ph is phenyl, and Cy is an abbreviation for cyclohexyl).

1) -2 titanium compound, zirconium _{compound: [t-BuNSiMe (Me 4} Cp)] TiCl 2, (Me 4 Cp) (O- i Pr 2 C 6 H 3) 2 TiCl, (Me 4 Cp) TiCl 3, (Me ₄ Cp) Ti (OBu) ₃ , [t-BuNSiMeFlu] TiMe ₂ , [t-BuNSiMeFlu] TiCl ₂ Et (Ind) ₂ ZrCl ₂ , Ph ₂ C (Ind) (Cp) ZrCl ₂ , ⁱ Pr (Cp ) (Flu) ZrCl ₂ , ⁱ Pr (3-tert-But-Cp) (Ind) ZrCl ₂ , ⁱ Pr (Cp) (Ind) ZrCl ₂ , Me ₂ Si (Ind) ₂ ZrCl ₂ , Cp ₂ ZrCl ₂ , [Cp is an abbreviation for Cyclopentadiene, Ind is an abbreviation for Indenyl, and Flu is an abbreviation for Fluorenyl. ] Etc. are mentioned.

  2) Compound selected from super strong acid, Lewis acid compound and ionic boron compound: Examples of super strong acid include hexafluoroantimonic acid, hexafluorophosphoric acid, hexafluoroarsenic acid, trifluoroacetic acid, fluorosulfuric acid, trifluoromethanesulfonic acid , Tetrafluoroboric acid, tetrakis (pentafluorophenyl) boric acid, tetrakis [3,5-bis (trifluoromethyl) phenyl] boric acid, p-toluenesulfonic acid, pentafluoropropionic acid and the like. Examples of Lewis acid compounds include complexes of boron trifluoride with ethers, amines, phenols, etc., complexes of aluminum trifluoride ethers, amines, phenols, tris (pentafluorophenyl) borane, tris [3,5 Boron compounds such as bis (trifluoromethyl) phenyl] borane, aluminum compounds such as aluminum trichloride, aluminum tribromide, ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum fluoride, tri (pentafluorophenyl) aluminum , Organic halogen compounds exhibiting Lewis acidity such as hexafluoroacetone, hexachloroacetone, chloranil, hexafluoromethyl ethyl ketone, and other Lewis acidity such as titanium tetrachloride and pentafluoroantimony Such compounds. Examples of the ionic boron compound include triphenylcarbenium tetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis [3,5-bis (trifluoromethyl) phenyl] borate, triphenylcarbeniumtetrakis (2,4 , 6-trifluorophenyl) borate, triphenylcarbenium tetraphenylborate, tributylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-diethylanilinium tetrakis (Pentafluorophenyl) borate, N, N-diphenylanilinium tetrakis (pentafluorophenyl) borate and the like.

  3) Organoaluminum compounds: for example, alkylalumoxane compounds such as methylalumoxane, ethylalumoxane, butylalumoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride, diethylaluminum chloride, diethylaluminum fluoride, ethyl Alkyl aluminum compounds and halogenated alkyl aluminum compounds such as aluminum sesquichloride and ethylaluminum dichloride, or a mixture of the alkylalumoxane compound and the alkylaluminum compound are preferably used.

  The components of the single complex catalyst or multicomponent catalyst are used in the following amounts. Transition metal compounds such as nickel compounds, palladium compounds, cobalt compounds, titanium compounds, and zirconium compounds are 0.02 to 100 millimole atoms per mole of monomer, and organoaluminum compounds are per mole of transition metal compound. 1 to 5,000 mol, and the super strong acid, Lewis acid, and ionic boron compound are 0 to 100 mol with respect to 1 mol atom of the transition metal compound.

  Cyclic olefin polymers use single complex catalysts or multicomponent catalysts composed of the above components, cycloaliphatic hydrocarbon solvents such as cyclohexane, cyclopentane and methylcyclopentane, and aliphatic carbonization such as hexane, heptane and octane. From hydrogen solvents, aromatic hydrocarbon solvents such as toluene, benzene, xylene, mesitylene, halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane, 1,1-dichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, etc. It can be obtained by performing polymerization in a temperature range of -20 to 120 ° C. in a solvent selected from two or more species.

(Cycloolefin ring-opening polymer)
As the cycloolefin polymer according to the present invention, a ring-opening polymer having a repeating unit represented by the following general formulas (5) and (6) can also be preferably used.

[Wherein, m is an integer of 1 or more, p is 0 or an integer of 1 or more, X represents a vinylene group (—CH═CH—) or an ethylene group (—CH ₂ CH ₂ —), and R ₁ -R ₄ each independently represents a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom having 1 to 30 carbon atoms which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. A hydrogen group; or a polar group.
Further, R ₁ and R ₂ , R ₃ and R ₄ or R ₂ and R ₃ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or other ring condensed to form a polycyclic structure. The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

[Wherein Y represents a vinylene group (—CH═CH—) or an ethylene group (—CH ₂ CH ₂ —), and R _{5 to} R ₈ each independently represents a hydrogen atom; a halogen atom; an oxygen atom; A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing a nitrogen atom, a sulfur atom or a silicon atom; or a polar group. Further, R ₅ and R ₆ , R ₇ and R ₈ or R ₆ and R ₇ are bonded to each other, and a carbocyclic or heterocyclic ring having a polycyclic structure by condensing a monocyclic structure or other ring (provided that (Except for the structure represented by the general formula (1)), and the formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]
The polymers of the general formulas (5) and (6) are synthesized as (co) polymers of monomers (hereinafter also referred to as “specific polymers”) shown in the following (A) to (D).
(A) A ring-opening polymer of a compound represented by the following general formula (7) (hereinafter also referred to as “specific monomer D”).
(B) A ring-opening polymer of a specific monomer D and a compound copolymerizable with the specific monomer D (hereinafter also referred to as “copolymerizable monomer”).
(C) A hydrogenated product of the ring-opening polymer (a) or the ring-opening polymer (b).
(D) A compound obtained by cyclization of the ring-opened polymer of (b) or (b) by a Friedel-Craft reaction or a hydrogenated product thereof.

[Wherein, m is an integer of 1 or more, p is 0 or an integer of 1 or more, and R _{1 to} R ₄ are each independently a hydrogen atom; a halogen atom; an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom. A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing; or a polar group. Further, R ₁ and R ₂ , R ₃ and R ₄ or R ₂ and R ₃ are bonded to each other to form a carbocyclic or heterocyclic ring having a monocyclic structure or other ring condensed to form a polycyclic structure. The formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

  The specific polymer uses a compound represented by the following general formula (8) as a copolymerizable monomer (hereinafter also referred to as “specific monomer E”), a specific monomer D, and a specific monomer It is preferable that it is obtained by copolymerizing with the monomer E. According to the specific polymer having such a configuration, the finally obtained specific retardation film has more excellent mechanical properties such as toughness, and is required for the specific retardation film by stretching. It becomes easy to obtain a desired retardation.

[Wherein, R _{5 to} R ₈ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom optionally having a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom] A hydrocarbon group of 1 to 30; or a polar group. Further, R ₅ and R ₆ , R ₇ and R ₈ or R ₆ and R ₇ are bonded to each other, and a monocyclic structure or other ring is condensed with a carbocyclic or heterocyclic ring having a polycyclic structure (provided that (Except for the structure represented by the general formula (5)), and the formed carbocyclic or heterocyclic ring may be an aromatic ring or a non-aromatic ring. ]

  Furthermore, the specific polymer is a ring-opening polymer of the specific monomer D and the specific monomer E, and is a structure derived from the specific monomer D represented by the general formula (5). A unit (hereinafter also referred to as “structural unit d”) and a structural unit derived from the specific monomer E represented by the general formula (6) (hereinafter also referred to as “structural unit e”). It is preferable to have it. The specific polymer having such a configuration is preferable in that a balance between heat resistance and heat processability by stretching or the like can be achieved.

As a halogen atom in General formula (7)-General formula (8), a fluorine atom, a chlorine atom, and a bromine atom are mentioned.
Examples of the hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as methyl group, ethyl group, and propyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; alkenyl groups such as vinyl group, allyl group, and propenyl group. Etc.

Further, the substituted or unsubstituted hydrocarbon group in the general formula (5) to the general formula (8) may be directly bonded to the ring structure, or may be bonded via a linking group. Good.
Examples of the linking group include a divalent hydrocarbon group having 1 to 10 carbon atoms [for example, an alkylene group represented by — (CH ₂ ) q — (wherein q is an integer of 1 to 10)]; oxygen Linking group containing an atom, nitrogen atom, sulfur atom or silicon atom [for example, carbonyl group (—CO—), oxycarbonyl group (—O (CO) —), sulfone group (—SO ₂ —), ether bond (— O-), thioether bond (-S-), imino group (-NH-), amide bond (-NHCO-, -CONH-), siloxane bond (-OSi (R9 8-methyl-8-n-propoxycarbonyltetra) Cyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyl-8-isopropoxycarbonyltetracyclo [4.4.0.12,12,5.17,10]- 3-dodecene, 8-fu Fluoro-8-pentafluoroethyl-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8,9-difluoro-8-heptafluoroiso -Propyl-9-trifluoromethyltetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-chloro-8,9,9-trifluorotetracyclo [4.4.0 .12,5.17,10] -3-dodecene, 8,9-dichloro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene 8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyl-8- (2,2,2-tri Fluoroethoxycarbonyl Tetracyclo [4.4.0.12,5 .17,10] -3-dodecene,

8- (4-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (4-biphenylcarbonyloxyethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (4-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (2-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (2-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (3-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (3-biphenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (1-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (1-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (2-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (2-naphthylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8- (9-anthracenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 8-methyl-8- (9-anthracenylcarbonyloxymethyl) tetracyclo [4.4.0.12,5. 17,10] -3-dodecene, 1,2- (2H, 3H- [1,3] epicyclopenta) -1,2-dihydroacenaphthylene and Diels-Alder adduct of cyclopentadiene However, the specific monomer D is not limited to these compounds. Moreover, these compounds can be used as specific monomer D individually or in combination of 2 or more types.

Among these, preferred compounds having at least one polar group in the molecule, in particular, in the general formula (3), a hydrocarbon group of R ₁ and R ₃ is C1-10 hydrogen atom or a carbon atom, R ₂ and R ₄ correspond to a hydrogen atom or a monovalent organic group, and at least one of R ₂ and R ₄ is a polar group other than a hydrogen atom and a hydrocarbon group, This is preferable because it improves the adhesiveness and adhesiveness.

  Here, the content of the polar group in the obtained specific polymer is determined by a desired function or the like required for the finally obtained specific retardation film, and is not particularly limited. The structural unit derived from the specific monomer D having a polar group in all structural units derived from the monomer a is usually 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more. The whole structural unit derived from the specific monomer D may have a polar group.

Further, as the specific monomer D, in the general formula (7), it is preferable that at least one of R ₂ and R ₄ has a polar group represented by the general formula (9). This is preferable in that the glass transition temperature and water absorption of the coalesce can be easily controlled.

[In the formula, n is an integer of 0 to 5, and R ₁₀ is a monovalent organic group. ]

Specific examples of the monovalent organic group represented by R ₁₀ in the general formula (9) include, for example, alkyl groups such as methyl group, ethyl group, and propyl group; phenyl group, naphthyl group, anthracenyl group, biphenylyl group, and the like. In addition to this, monovalent groups having an aromatic ring such as fluorenes such as diphenylsulfone and tetrahydrofluorene, and a heterocyclic ring such as a furan ring and an imide ring are also included.
Moreover, in General formula (9), n is an integer of 0-5, Preferably it is an integer of 0-2, More preferably, it is 0. The smaller the value of n, the higher the glass transition temperature of the specific polymer obtained, which is preferable. In particular, the specific monomer a having n of 0 is preferable in that its synthesis is easy.
Furthermore, the specific monomer a is preferably one in which an alkyl group is further bonded to the carbon atom to which the polar group represented by the general formula (9) is bonded in the general formula (7). It is possible to achieve a balance between heat resistance and water absorption of the specific polymer. Here, the number of carbon atoms of the alkyl group is preferably 1 to 5, more preferably 1 to 2, and particularly preferably 1.

Moreover, as the specific monomer D, those in which m is 1 and p is 0 in the general formula (7) are preferable in that a specific polymer having a high glass transition temperature is obtained.
Specific examples of the specific monomer E include
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [5.2.1.02,6] dec-8-ene,
Tricyclo [6.2.1.02,7] undec-9-ene,
5-methylbicyclo [2.2.1] hept-2-ene,
5-ethylbicyclo [2.2.1] hept-2-ene,
5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-cyanobicyclo [2.2.1] hept-2-ene,
5-ethylidenebicyclo [2.2.1] hept-2-ene,
5-phenylbicyclo [2.2.1] hept-2-ene,
5- (2-naphthyl) bicyclo [2.2.1] hept-2-ene (α-form and β-form),
5-fluorobicyclo [2.2.1] hept-2-ene,
5-fluoromethylbicyclo [2.2.1] hept-2-ene,
5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-pentafluoroethylbicyclo [2.2.1] hept-2-ene,

5,5-difluorobicyclo [2.2.1] hept-2-ene,
5,6-difluorobicyclo [2.2.1] hept-2-ene,
5,5-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5,5,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,5,6-tris (fluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrafluorobicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5-difluoro-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-fluoro-5-pentafluoroethyl-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5-heptafluoro-iso-propyl-6-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-chloro-5,6,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,6-dichloro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-trifluoromethoxybicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hept-2-ene,
5- (4-Phenylphenyl) bicyclo [2.2.1] hept-2-ene

4- (bicyclo [2.2.1] hept-5-en-2-yl) phenylsulfonylbenzene,
5- (4-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (4-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5- (4-biphenylcarbonyloxypropyl) bicyclo [2.2.1] hept-2-ene,

5-methyl-5- (4-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (2-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (3-biphenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (3-biphenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5- (1-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (1-naphthylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,

5-methyl-5- (1-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-naphthylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (2-naphthylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (2-naphthylcarbonyloxymethyl) methylbicyclo [2.2.1] hept-2-ene,
5- (9-anthracenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
5- (9-anthracenylcarbonyloxyethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5- (9-anthracenylcarbonyloxymethyl) bicyclo [2.2.1] hept-2-ene,
Examples thereof include Diels-Alder adducts of acenaphthylene and cyclopentadiene, but the specific monomer e is not limited to these compounds. These compounds can be used as the specific monomer e alone or in combination of two or more.

The specific polymer obtained by copolymerizing the specific monomer D and the specific monomer E is a copolymerizable monomer other than the specific monomer D and the specific monomer E. It may be copolymerized with the body.
Examples of other copolymerizable monomers include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene. The number of carbon atoms in the cycloolefin is preferably 4-20, and more preferably 5-12. Furthermore, in the presence of unsaturated hydrocarbon polymers having an olefinically unsaturated bond in the main chain such as polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-nonconjugated diene copolymer, polynorbornene, etc. The monomer D and, if necessary, a specific monomer E may be polymerized, and the specific polymer thus obtained is useful as a raw material for a resin having high impact resistance.

  The specific viscosity (ηinh) of the specific polymer measured in chloroform at 30 ° C. is preferably 0.2 to 5 dl / g. More preferably, it is 0.3-4 dl / g, Most preferably, it is 0.5-3 dl / g. If it exceeds 5 dl / g, the solution viscosity becomes too high and the processability may be deteriorated, and if it is less than 0.2 dl / g, the film strength may be lowered.

As the molecular weight of the specific polymer, the number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) is usually 8,000 to 1,000,000, preferably 10,000 to 500. , More preferably 20,000 to 100,000, particularly preferably 30,000 to 100,000, and the weight average molecular weight (Mw) is usually 20,000 to 3,000,000, preferably 30 , 1,000 to 1,000,000, more preferably 40,000 to 500,000, particularly preferably 40,000 to 300,000.
The molecular weight distribution of the specific polymer is such that the above-mentioned Mw / Mn is usually 1.5 to 10, preferably 2 to 8, more preferably 2.5 to 5, particularly preferably 2.5 to 4.5. .

  The glass transition temperature (Tg) of the specific polymer may be changed as appropriate by adjusting the type of the structural unit a and the structural unit b of the specific polymer, the ratio of the structural unit a and the structural unit b, or the addition of an additive. However, it is usually 100 to 250 ° C, preferably 110 to 200 ° C, more preferably 120 to 180 ° C. When Tg is 100 ° C. or lower, the heat distortion temperature is lowered, which may cause a problem in heat resistance, and the optical properties of the finally obtained film may be greatly affected by the temperature. Moreover, when Tg is 250 ° C. or higher, there is a high possibility that the thermoplastic norbornene-based resin is thermally deteriorated when heated to the vicinity of Tg for processing such as stretching.

  In the specific polymer having the structural unit d and the structural unit e, the ratio (D / E) of the specific monomer D to the specific monomer E is preferably D / E = 95 / in molar ratio. 5 to 5/95, more preferably 95/5 to 60/40. If the proportion of the structural unit d is larger than the above range, the effect of improving toughness and desired optical properties may not be expected. Conversely, if the proportion of the structural unit d is smaller than the above range, the glass transition temperature is lowered and the heat resistance is decreased. May cause problems.

  Furthermore, in the specific polymer having the structural unit d and the structural unit e, it is preferable that the ratio (composition ratio) between the structural unit d and the structural unit e in the polymer is small in the entire molecular weight distribution range. Specifically, with respect to the ratio of the specific monomer D and the specific monomer E subjected to the polymerization reaction, the composition ratio at an arbitrary molecular weight is within ± 50%, preferably within ± 30%. More preferably, a more uniform specific retardation film can be obtained by keeping the variation range within ± 20%. Further, by being within such a range, it becomes possible to obtain a more uniform retardation when stretched and oriented.

  In the following, ring-opening copolymerization of specific monomer D and, if necessary, specific monomer E or other copolymerizable monomer, or ring-opening copolymerization of these monomers Then, conditions for producing a specific polymer obtained by hydrogenating the obtained ring-opening copolymer will be described.

Ring-opening polymerization catalyst:
The ring-opening polymerization reaction of the monomer is performed in the presence of a metathesis catalyst.
This metathesis catalyst comprises (a) at least one selected from W, Mo and Re compounds, (b) a Deaming Periodic Table Group IA element (for example, Li, Na, K, etc.), IIA Group element (for example, Mg, Ca, etc.), group IIB elements (eg, Zn, Cd, Hg, etc.), group IIIB elements (eg, B, Al, etc.), group IVA elements (eg, Ti, Zr, etc.) or group IVB elements (eg, Si, Sn, etc.) Pb or the like), which is a catalyst comprising a combination with at least one element selected from at least one of the element-carbon bond or the element-hydrogen bond. In this case, in order to increase the activity of the catalyst, an additive (c) described later may be added.

Representative examples of W, Mo or Re compounds suitable as component (a) include compounds described in JP-A-1-240517 such as WCl ₆ , MoCl ₅ and ReOCl ₃ .
Specific examples of the component (b) include n-C ₄ H ₉ Li, (C ₂ H ₅ ) ₃ Al, (C ₂ H ₅ ) ₂ AlCl, (C ₂ H ₅ ) _1.5 AlCl _1.5 , (C ₂ H ₅₎ AlCl _2, mention may be made of methyl alumoxane, compounds described in JP-a 1-240517 discloses such LiH.
As typical examples of the component (c), alcohols, aldehydes, ketones, amines and the like can be preferably used, and compounds described in JP-A-1-240517 can be further used.

The amount of the metathesis catalyst used is a molar ratio of the component (a) to the specific monomer D and the specific monomer E (hereinafter, both are collectively referred to as “specific monomer”) ( a) Component: The specific monomer is usually in a range of 1: 500 to 1: 50000, preferably in a range of 1: 1000 to 1: 10000.
The ratio of the component (a) to the component (b) is such that “(a) :( b)” is 1: 1 to 1:50, preferably 1: 2 to 1:30 in terms of metal atomic ratio.
The ratio of the component (a) to the component (c) is such that the molar ratio “(c) :( a)” is 0.005: 1 to 15: 1, preferably 0.05: 1 to 7: 1. It is.

Molecular weight regulator:
The molecular weight of the specific polymer can be adjusted depending on the polymerization temperature, the type of catalyst, and the type of solvent. In the present invention, it is preferable to adjust the molecular weight by allowing the molecular weight regulator to coexist in the reaction system. Suitable molecular weight regulators include, for example, α-olefins such as ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and styrene. Of these, 1-butene and 1-hexene are preferred.
These molecular weight regulators can be used alone or in combination of two or more.
The amount of the molecular weight regulator used is 0.005 to 0.6 mol, preferably 0.02 to 0.5 mol, per 1 mol of the specific monomer subjected to the polymerization reaction.

Solvent for ring-opening polymerization reaction:
Examples of the solvent used in the ring-opening polymerization reaction include alkanes such as pentane, hexane, heptane, octane, nonane, decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane; benzene, toluene, xylene Aromatic hydrocarbons such as ethylbenzene and cumene; halogenated hydrocarbon compounds such as chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, chlorobenzene, chloroform, and tetrachloroethylene; ethyl acetate, n-butyl acetate, acetic acid Saturated carboxylic acid esters such as iso-butyl and methyl propionate; and ethers such as dimethoxyethane, dibutyl ether, and tetrahydrofuran, which are used alone There can be used in combination of two or more kinds. Among these, the above aromatic hydrocarbons are preferable.
The amount of the solvent used is such that the solvent: specific monomer (weight ratio) is usually 1: 1 to 10: 1, preferably 1: 1 to 5: 1.

Hydrogenation:
The ring-opening copolymer obtained by the above ring-opening polymerization can be used as a specific polymer as it is, but a hydrogenated product obtained by hydrogenating olefinically unsaturated bonds remaining in the ring-opening copolymer It is preferable to do.
This hydrogenated product has excellent thermal stability, and its characteristics are not easily deteriorated by heating during film formation processing, stretching processing, or use as a product. In such a hydrogenated product, the hydrogenation rate with respect to the olefinically unsaturated bond is 50% or more, preferably 70% or more, more preferably 90% or more, and particularly preferably 98% or more. Moreover, when the ring-opening copolymer subjected to hydrogenation has an aromatic ring in the molecule, it is preferable that the aromatic ring is not substantially hydrogenated after hydrogenation.

  In the hydrogenation reaction, a hydrogenation catalyst is added to an ordinary method, that is, a solution of a ring-opening copolymer, and hydrogen gas at normal pressure to 300 atm, preferably 3 to 200 atm, is added to 0 to 200 ° C., preferably It is performed by operating at 20 to 180 ° C.

As a hydrogenation catalyst, what is used for the hydrogenation reaction of a normal olefinic compound can be used. As this hydrogenation catalyst, a heterogeneous catalyst and a homogeneous catalyst are known. In addition, when hydrogenating a ring-opening polymer having a substituent having an aromatic ring in the molecule, it is preferable to select conditions under which the unsaturated bond of the aromatic ring is not substantially hydrogenated.
Examples of the heterogeneous catalyst include solid catalysts in which noble metals such as palladium, platinum, nickel, rhodium, and ruthenium are supported on a carrier such as carbon, silica, alumina, and titania. In addition, homogeneous catalysts include nickel naphthenate / triethylaluminum, nickel acetylacetonate / triethylaluminum, cobalt octenoate / n-butyllithium, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium. Dichlorotris (triphenylphosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, dichlorocarbonyltris (triphenylphosphine) ruthenium, and the like. The form of the catalyst may be powder or granular.
These hydrogenation catalysts are used in such a ratio that the ring-opening polymer: hydrogenation catalyst (weight ratio) is 1: 1 × 10 −6 to 1: 2.

  Commercial films such as JSR Arton Co., Ltd. and Nippon Zeon Co., Ltd. ZEONOR can also be preferably used as the thermoplastic norbornene resin of the present invention.

(Film production)
In the present invention, a thermoplastic norbornene resin made of a specific polymer can be formed into a film by a melt molding method or a solution casting method (solvent casting method), etc., but the thickness is highly uniform and the surface smoothness is high. However, it is preferable to use a solvent casting method in that an unprocessed film can be obtained. As the solvent casting method, for example, a thermoplastic norbornene resin is dissolved or dispersed in a solvent to prepare a film forming solution containing the thermoplastic norbornene resin at an appropriate concentration. For example, a method of pouring or coating on a suitable carrier, drying it and then peeling it from the carrier.

  When the thermoplastic norbornene resin is dissolved or dispersed in the solvent, the concentration of the thermoplastic norbornene resin is usually 0.1 to 90% by weight, preferably 1 to 50% by weight, more preferably 10 to 35% by weight. %. When this concentration is less than 0.1% by weight, it may be difficult to obtain a pre-processed film having a required thickness, and when the solvent is removed by drying, the solvent may be evaporated. Accordingly, foaming or the like is likely to occur, and it may be difficult to obtain a pre-processed film having good surface smoothness. On the other hand, when the concentration exceeds 90% by weight, the solution viscosity of the film-forming solution becomes too high, and it may be difficult to obtain a film having a uniform thickness and surface condition.

  The viscosity of the film-forming solution is usually 1 to 1,000,000 (mPa · s), preferably 10 to 100,000 (mPa · s), more preferably 100 to 50,000 (mPa · s) at room temperature. s), particularly preferably 1000 to 40,000 (mPa · s).

  Solvents used for the preparation of the film forming liquid include aromatic solvents such as benzene, toluene and xylene, cellosolve solvents such as methyl cellosolve, ethyl cellosolve and 1-methoxy-2-propanol, diacetone alcohol, acetone and cyclohexanone. Ketone solvents such as methyl ethyl ketone, 4-methyl-2-pentanone, cyclohexanone, ethyl cyclohexanone and 1,2-dimethylcyclohexane, ester solvents such as methyl lactate and ethyl lactate, 2,2,3,3-tetrafluoro- Examples thereof include halogen-containing solvents such as 1-propanol, methylene chloride and chloroform, ether solvents such as tetrahydrofuran and dioxane, and alcohol solvents such as 1-pentanol and 1-butanol.

  In addition to the above solvents, the SP value (solubility parameter) is usually 10-30 (MPa1 / 2), preferably 10-25 (MPa1 / 2), more preferably 15-25 (MPa1 / 2), especially When a solvent in the range of preferably 15 to 20 (MPa1 / 2) is used, a processed film having good surface uniformity and optical properties can be obtained.

  Said solvent can be used individually or in combination of 2 or more types. When two or more solvents are used in combination, the SP value range of the obtained mixed solvent is preferably within the above range. At this time, the SP value of the mixed solvent can be determined from the weight ratio of each solvent constituting the mixed solvent. For example, in a mixed solvent obtained from two types of solvents, the SP value of each solvent and their values When the weight fraction is W1 and W2 and the SP value is SP1 and SP2, the SP value of the mixed solvent can be calculated by the formula: SP value = W1 · SP1 + W2 · SP2.

In the case of using a mixed solvent as a solvent in the film forming liquid, it is possible to obtain a pre-processed film having a light diffusion function by combining a good solvent and a poor solvent with respect to the thermoplastic norbornene resin. it can. Specifically, when the SP value of the thermoplastic norbornene resin is SPx, the SP value of the good solvent of the thermoplastic norbornene resin is SPy, and the SP value of the poor solvent of the thermoplastic norbornene resin is SPz, SPx and SPy Is preferably 7 or less, more preferably 5 or less, particularly preferably 3 or less, and the difference between SPx and SPz is preferably 7 or more, more preferably 8 or more, and particularly preferably 9 or more. And the difference between SPz is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more, so that a light diffusion function can be imparted to the resulting pre-processed film. The specific retardation film can have a light diffusion function.
The proportion of the poor solvent in the mixed solvent is preferably 50% by weight or less, more preferably 30% by weight or less, particularly preferably 15% by weight or less, and most preferably 10% by weight or less. The difference between the boiling point of the poor solvent and the boiling point of the good solvent is preferably 1 ° C. or higher, more preferably 5 ° C. or higher, particularly preferably 10 ° C. or higher, and most preferably 20 ° C. or higher. It is preferably higher than the boiling point of the good solvent.

The temperature at which the thermoplastic norbornene-based resin is dissolved or dispersed in the solvent may be room temperature or high, and by sufficiently stirring, a film-forming solution in which the thermoplastic norbornene-based resin is uniformly dissolved or dispersed can be obtained. Moreover, coloring agents, such as a dye and a pigment, can be suitably added to a film formation liquid as needed, and, thereby, the colored film before processing can be obtained.
Moreover, you may add a leveling agent to a film formation liquid for the purpose of improving the surface smoothness of the film before processing obtained. As such leveling agents, various ones can be used if they are general, and specific examples thereof include fluorine-based nonionic surfactants, special acrylic resin leveling agents, silicone leveling agents and the like. .

As a carrier for forming the liquid layer of the film forming liquid, it is possible to use a metal drum, a steel belt, a polyester film made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a belt made of polytetrafluoroethylene, or the like. it can. As a method for applying the film forming liquid, a method using a die or a coater, a spray method, a brush coating method, a roll coating method, a spin coating method, a dipping method, or the like can be used.
Moreover, the thickness and surface smoothness of the pre-processed film obtained can also be controlled by apply | coating a film forming liquid repeatedly.

When a polyester film is used as the carrier, a surface-treated film may be used.
As a surface treatment method, a hydrophilic treatment method generally performed, for example, a method of laminating an acrylic resin or a sulfonate group-containing resin by coating or lamination, or a hydrophilic property of the film surface by corona discharge treatment or the like. The method etc. which improve are mentioned.

  In the solvent casting method, a specific method for removing the solvent in the liquid layer is not particularly limited, and a commonly used drying treatment method, for example, a method of passing through a drying furnace by a large number of rollers is used. However, if bubbles are generated as the solvent evaporates in the drying process, the properties of the specific retardation film finally obtained are significantly deteriorated. To avoid this, the drying process is performed in two or more stages. It is preferable to control the temperature or the air volume in each step.

  The amount of residual solvent in the pre-processed film thus obtained is usually 10% by weight or less, preferably 5% by weight or less, more preferably 1% by weight or less, and particularly preferably 0.5% by weight or less. Here, when the residual solvent amount in the film before processing exceeds 10% by weight, the dimensional change with time is large when the specific retardation film obtained by stretching the film before processing is actually used. It is not preferable. Further, the residual solvent lowers the glass transition temperature and lowers the heat resistance, which is not preferable.

  Moreover, in order to perform the extending | stretching process mentioned later suitably, it may be necessary to adjust the residual solvent amount in the film before a process suitably within the said range. Specifically, the amount of residual solvent in the film before processing is usually 10 to 0.1% by weight, preferably 5 to 0.1% by weight, in order to stably and uniformly express the phase difference in the film by stretching and orientation treatment. %, More preferably 1 to 0.1% by weight. By leaving a trace amount of solvent in the pre-processed film, the stretching and orientation treatment may be facilitated or the retardation may be easily controlled.

In the present invention, the thickness of the film before processing is usually 1 to 500 μm (1,000 to 500,000 nm), preferably 1 to 300 μm (1,000 to 300,000 nm), more preferably 1 to 200 μm (1,000). ˜200,000), most preferably 1 to 100 μm (1,000 to 100,000 nm). When this thickness is less than 1 μm, it becomes difficult to substantially handle the unprocessed film. On the other hand, when the thickness is 500 μm or more, when the pre-processed film is wound up in a roll shape, a so-called “wrapping” may be attached and handling in post-processing or the like may be difficult.
The thickness distribution of the film before processing is usually within ± 20%, preferably within ± 10%, more preferably within ± 5%, particularly preferably within ± 3% with respect to the average value. The thickness variation per cm is usually 10% or less, preferably 5% or less, more preferably 1% or less, and particularly preferably 0.5% or less. By controlling the thickness distribution of the unprocessed film within the above range, it is possible to prevent the occurrence of retardation unevenness when the stretching and orientation treatment is performed on the unprocessed film.

Specific examples of the stretching method for producing the specific retardation film include known uniaxial stretching methods and biaxial stretching methods.
That is, by the horizontal uniaxial stretching method by the tenter method, the compression stretching method between rolls, the longitudinal uniaxial stretching method using two sets of rolls with different circumferences, or the biaxial stretching method combining the horizontal uniaxial and the longitudinal uniaxial, the inflation method A stretching method or the like can be used.
In the case of the uniaxial stretching method, the stretching speed is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, more preferably 100 to 1,000% / min, particularly preferably. Is 100-500% / min.
In the case of the biaxial stretching method, stretching may be performed in two directions at the same time, or the stretching may be performed in a direction different from the first stretching direction after uniaxial stretching. At this time, the intersecting angle of the two stretching axes for controlling the shape of the refractive index ellipsoid of the stretched film is not particularly limited because it is determined by desired characteristics, but is usually in the range of 120 to 60 degrees. is there. The stretching speed may be the same or different in each stretching direction, and is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, and more preferably 100 to 1,000% / min, particularly preferably 100 to 500% / min.

The treatment temperature in the stretching alignment treatment is not particularly limited, but is usually Tg ± 30 ° C., preferably Tg ± 15 ° C., more preferably Tg, based on the glass transition temperature Tg of the thermoplastic norbornene resin used. It is in the range of −5 ° C. to Tg + 15 ° C. By setting the treatment temperature within the above range, it is possible to suppress the occurrence of phase difference unevenness, and control of the refractive index ellipsoid is facilitated, which is preferable.
The draw ratio is not particularly limited because it is determined by desired properties, but is usually 1.01 to 10 times, preferably 1.03 to 5 times, and more preferably 1.03 to 3 times. When the draw ratio is 10 times or more, it may be difficult to control the phase difference.

  The stretched film may be cooled as it is, but is heat set by holding it in a temperature atmosphere of Tg-20 ° C. to Tg for at least 10 seconds, preferably 30 seconds to 60 minutes, more preferably 1 minute to 60 minutes. It is preferable to do. As a result, a stable retardation film can be obtained with little change over time in the retardation of transmitted light.

The dimensional shrinkage due to heating of the specific retardation film is usually 10% or less, preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less when heated at 100 ° C. for 500 hours. .
In order to make the dimensional shrinkage rate in the above range, in addition to selection of the raw material of the thermoplastic norbornene resin, for example, the specific monomer a, the specific monomer b or other copolymerizable monomer, cast It is possible to control by the method and the stretching method.
In addition, the dimensional shrinkage ratio due to heating of the pre-processed film in a state where the stretch orientation treatment has not been performed is usually 5% or less, preferably 3% or less, more preferably 1% when heating at 100 ° C. is performed for 500 hours. Hereinafter, it is particularly preferably 0.5% or less.

  The film stretched as described above gives a phase difference to transmitted light due to the orientation of molecules by stretching. This phase difference is determined by the type of thermoplastic norbornene resin used as a raw material, It can be controlled by adjusting the magnification, the stretching temperature or the thickness of the film before stretching (film before processing). For example, as for the draw ratio, even if the film has the same thickness before drawing, the absolute value of the retardation of transmitted light tends to increase as the draw ratio increases. A film that imparts a retardation to transmitted light can be obtained. In addition, as for the thickness of the film before stretching (film before processing), even if the stretching ratio is the same, the larger the thickness of the film before stretching, the larger the absolute value of the phase difference given to transmitted light tends to increase. By changing the thickness of the film before stretching, a retardation film that imparts a desired retardation to transmitted light can be obtained. In addition, with respect to the stretching treatment temperature, the lower the stretching temperature, the greater the absolute value of the retardation of the transmitted light. Therefore, by changing the stretching temperature, a retardation film that gives the desired retardation to the transmitted light is obtained. be able to.

  Moreover, in order to adjust the thickness of a specific phase difference film, it can control by adjusting the thickness of a film before a process, a draw ratio, etc. Specifically, for example, the thickness of the retardation film can be reduced by reducing the thickness of the film before processing or increasing the draw ratio.

In such a specific retardation film, the number of bright spots when converted per 1 m ² on the film surface is 10 or less, preferably 7 or less, more preferably 5 or less, and particularly preferably 3 Hereinafter, it is most preferably 0 or 1.
Here, the “bright spot” is a partial light leakage that is confirmed with the naked eye when the specific retardation film is sandwiched between crossed Nicols polarizing plates, and usually has an outer diameter of 1 μm or more (circular shape). If it is, the diameter is measured, and if it is other shape, the length in the longitudinal direction is measured.
Of course, depending on the required performance, a smaller one may be measured as a bright spot. Such bright spots are considered to be caused by partial unevenness of the phase difference in a minute region. That is, when there are foreign objects, bubbles, etc. in the film before processing, even if they are in a size that cannot be confirmed with the naked eye, when the stretch process is performed, stress concentrates on the portions where foreign objects, bubbles, etc. exist, It is considered that the phase difference in the stress concentrated portion may be different from the phase difference in the peripheral portion, and light leaks due to the difference in the phase difference.

Further, in the specific retardation film, the number of foreign matters when converted per 1 m ² on the film surface is preferably 10 or less, more preferably 5 or less, particularly preferably 3 or less, and most preferably 0. Or it is set to 1.
The term “foreign matter” as used herein substantially prevents light transmission when light is transmitted through the specific retardation film. When such a foreign substance is present in the specific retardation film, the transmitted light intensity is affected, and when used in a liquid crystal display element or the like, there is a possibility of causing pixel omission or deterioration of characteristics.
The size of the foreign matter to be measured is usually an outer diameter of 1 μm or more (the diameter if it is circular, the length in the longitudinal direction if it is of other shapes), but depending on the required performance Something smaller than this may be measured as a foreign object.

(Film retardation)
The retardation of the stretched polymer film in the present invention obtained by the above steps preferably satisfies the following formulas (A1), (B1), and (G) to (J).
30 nm <Re (546) <400 nm (A1)
30 nm <Rth (546) <400 nm (B1)
0.95 <Re (480) / Re (546) <1.05 (G)
0.95 <Re (628) / Re (546) <1.05 (H)
0.95 <Rth (480) / Rth (546) <1.05 (I)
0.95 <Rth (628) / Re (546) <1.05 (J)
Formula (A1) is more preferably 40 nm <Re (546) <300 nm, and most preferably 40 nm <Re (546) <200 nm.
Formula (B1) is more preferably 50 nm <Rth (546) <300 nm, most preferably 70 nm <Rth (546) <250 nm. Formula (G) is more preferably 0.98 <Re (480) / Re (546) <1.02.
By setting the wavelength dispersion of retardation within the above range, an optical compensation sheet having a large effect of improving contrast and color can be obtained.

  In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at a wavelength λ, respectively. Re (λ) is measured in KOBRA 21ADH (manufactured by Oji Scientific Instruments) by making light having a wavelength of λ nm incident in the normal direction of the film. Rth (λ) is 10 degrees from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH) and the tilt axis (rotation axis). In step, light of wavelength λ nm is incident from each inclined direction and measured at 11 points, and KOBRA 21ADH calculates based on the measured retardation value, the assumed average refractive index, and the input film thickness value. Here, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). KOBRA 21ADH calculates nx, ny, and nz by inputting these assumed values of average refractive index and film thickness. Nz = (nx-nz) / (nx-ny) is further calculated from the calculated nx, ny, and nz.

(Photoelasticity)
The stretched polymer film according to the present invention preferably has a photoelastic coefficient of 5 × 10 ⁻⁸ cm ² / N or less, more preferably 4 × 10 ⁻⁸ cm ² / N, and even more preferably 3 × 10 ⁻⁸ cm ² / N. (5 × 10 ⁻¹³ cm ² / dyn). By setting the photoelastic coefficient of the stretched polymer film within the above range, there is an effect that the retardation change of the optical compensation film can be reduced when the stretched polymer film is exposed to high temperature and high humidity while being incorporated in the polarizing plate. In addition, when using the optical compensation film of the present invention having an optically anisotropic layer on a stretched polymer film as a protective film for a polarizing plate, the photoelastic coefficient of the two protective films disposed at both ends of the polarizer is When they are different from each other, the photoelastic coefficient of the protective film used on the liquid crystal cell side is preferably smaller than the photoelastic coefficient of the air-side protective film. The photoelastic coefficient can be obtained by an ellipsometer (Shimadzu Corporation).

(Moisture permeability)
The moisture permeability is calculated as the amount of moisture (g) that evaporates in 24 hours per 1 m ^{2 of} area by measuring the moisture permeability of each sample in accordance with the method described in JIS Z 0208. The moisture permeability of the polarizing plate protective film is a film physical property closely related to the durability of the polarizing plate. It is known that a polarizer in which polyvinyl alcohol is dyed with iodine promotes deterioration of polarization performance due to decolorization of iodine. In order to remove moisture by drying during the production of the polarizing plate, it is preferable to lower the moisture permeability. On the other hand, when the polarizing plate is produced, it is preferable that the moisture permeability is low because the entry of moisture from the outside is suppressed.
Therefore, in order to satisfy the conflicting requirements, the polarizing plate protective film needs to have an appropriate water permeability. Accordingly, the moisture permeability at 60 ° C. and 90% RH 24 hr of the stretched polymer film to be attached to the polarizer as the protective film for the polarizing plate is preferably 1 g / m ² or more and 1000 g / m ² or less, and 10 g / m ² or more and 700 g / m ^2. More preferred are:

(Equilibrium moisture content)
The moisture content of the film can be evaluated by measuring the equilibrium moisture content at a constant temperature and humidity. Equilibrium moisture content is calculated by measuring the moisture content of the sample that has reached equilibrium after it has been left at 25 ° C and 80% RH temperature and humidity for 24 hours, and dividing the moisture content (g) by the sample mass (g). It is a thing.
The stretched polymer film according to the present invention has an equilibrium water content at 25 ° C. and 80% RH of preferably 0.01% by mass to 2% by mass, and more preferably 0.01% by mass to 1% by mass.

(Film surface treatment)
The stretched polymer film according to the present invention has a surface to ensure adhesion between the polarizer and the optically anisotropic layer or the alignment layer provided between the optically anisotropic layer and the stretched polymer film according to the present invention. It is preferable that the surface is hydrophilized.
As the surface treatment method, for example, the adhesive layers described in JP-A-2000-24167, JP-A-10-130402, JP-A-2002-148436, JP-A-2002-90546, JP-A-2001-350017 are used. Hydrophilicity can also be imparted by a method of providing, or surface treatment such as corona discharge treatment described in JP-A-2001-350018.

(Optically anisotropic layer)
Next, the optically anisotropic layer in the present invention will be described in detail.
The optically anisotropic layer in the present invention preferably contains at least one liquid crystalline compound. The liquid crystal compound is preferably a rod-like liquid crystal compound or a discotic liquid crystal compound.
Moreover, it is preferable that the liquid crystalline compound in the present invention has absorption on the longer wavelength side than the monomer unit constituting the stretched polymer film. Thereby, the wavelength dispersion of retardation of the optical compensation sheet can be controlled to a desired pattern. The preferable range of the absorption maximum of the liquid crystalline compound in the present invention is 200 nm or more and 370 nm or less, more preferably 220 nm or more and 350 nm or less, and most preferably 240 nm or more and 330 nm or less. If the absorption maximum is too long, the bottom of absorption is in the visible range, and the optical compensation sheet is yellowish, which is not preferable.

  The optically anisotropic layer in the present invention is preferably formed by aligning a liquid crystalline compound using an alignment film and fixing the alignment state. In order to fix the alignment state of the liquid crystal compound, the liquid crystal compound preferably has a polymerizable group.

(Bar-shaped liquid crystalline compounds)
First, the rod-like liquid crystalline compound used in the optically anisotropic layer in the present invention will be described.
Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferred. Not only a low molecular liquid crystal compound but also a polymer liquid crystal compound can be used. The rod-like liquid crystalline compound having a low molecular polymerizable group which is particularly preferably used is a rod-like liquid crystalline compound of the following formula (I).

(I) Q1-L1-Cy1-L2- (Cy2-L3) n-Cy3-L4-Q2
In the formula, Q1 and Q2 are each independently a polymerizable group, L1, and L4 are each independently a divalent linking group, L2 and L3 are each independently a single bond or a divalent linking group, Cy1, Cy2 and Cy3 are divalent cyclic groups, and n is 0, 1 or 2.

The polymerizable rod-like liquid crystal compound will be further described below.
In the formula (I), Q1 and Q2 are each independently a polymerizable group. The polymerization reaction of the polymerizable group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

L1 and L4 are each independently a divalent linking group. L 1 and L 4 are each independently a divalent linkage selected from the group consisting of —O—, —S—, —CO—, —NR 2 —, a divalent chain group, a divalent cyclic group, and combinations thereof. A group is preferred. R2 is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom.
The example of the bivalent coupling group which consists of a combination is shown below. Here, the left side is coupled to Q (Q1 or Q2), and the right side is coupled to Cy (Cy1 or Cy3).

L-1: —CO—O—divalent chain group—O—
L-2: —CO—O—divalent chain group —O—CO—
L-3: —CO—O—divalent chain group —O—CO—O—
L-4: -CO-O-divalent chain group -O-divalent cyclic group-
L-5: —CO—O—divalent chain group—O—divalent cyclic group—CO—O—
L-6: -CO-O-divalent chain group -O-divalent cyclic group -O-CO-
L-7: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-
L-8: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-CO-O-
L-9: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-O-CO-
L-10: —CO—O—divalent chain group—O—CO—divalent cyclic group—
L-11: -CO-O-divalent chain group-O-CO-divalent cyclic group-CO-O-
L-12: -CO-O-divalent chain group -O-CO-divalent cyclic group -O-CO-
L-13: —CO—O—Divalent chain group—O—CO—Divalent cyclic group—Divalent chain group—
L-14: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-CO-O-
L-15: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-O-CO-
L-16: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—
L-17: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -CO-O-
L-18: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -O-CO-
L-19: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—divalent chain group—
L-20: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-CO-O-
L-21: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-O-CO-

The divalent chain group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group. An alkylene group, a substituted alkylene group, an alkenylene group and a substituted alkenylene group are preferred, and an alkylene group and an alkenylene group are more preferred.
The alkylene group may have a branch. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom.
The alkenylene group may have a branch. The alkenylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkenylene part of the substituted alkenylene group is the same as the above alkenylene group. Examples of the substituent include a halogen atom.
The alkynylene group may have a branch. The alkynylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include a halogen atom.
Specific examples of the divalent chain group include ethylene, trimethylene, propylene, butamethylene, 1-methyl-butamethylene, pentamethylene, hexamethylene, octamethylene, 2-butenylene, 2-butynylene and the like.

The definition and examples of the divalent cyclic group are the same as those of Cy1, Cy2 and Cy3 described later.
R2 is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom.

  In the formula (I), L2 and L3 are each independently a single bond or a divalent linking group. L 2 and L 3 are each independently a divalent linkage selected from the group consisting of —O—, —S—, —CO—, —NR 2 —, a divalent chain group, a divalent cyclic group, and combinations thereof. It is preferably a group or a single bond. R2 is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group or a hydrogen atom. Preferably, it is a hydrogen atom. The divalent chain group and the divalent cyclic group have the same definitions as L1 and L4.

  In the formula (I), n is 0, 1 or 2. When n is 2, the two L3s may be the same or different, and the two Cy2s may be the same or different. n is preferably 1 or 2, and more preferably 1.

In formula (I), Cy1, Cy2 and Cy3 are each independently a divalent cyclic group.
The ring contained in the cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring.
The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring.
The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.
As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. The cyclic group having a pyrimidine ring is preferably pyrimidine-2,5-diyl.
The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. An alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms And an acylamino group having 2 to 6 carbon atoms.

  Examples of the polymerizable liquid crystal compound represented by the formula (I) are shown below. The present invention is not limited to these.

  Discotic liquid crystalline compounds are known in various literatures (for example, C. Destrade et.al., Mol. Cryst. Vol. 71, page 111 (1981); edited by the Chemical Society of Japan, Quarterly Chemical Review, No. 22, Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et.al., Angew. Chem. Soc. Chem., Comm., Page 1794 (1985); J. Zhang et.al., J. Am. Chem. Soc., Vol. 116, page 2655 (1994)). The discotic liquid crystalline compound that is preferably used in the optically anisotropic layer is also described in JP-A-8-50286.

  The optically anisotropic layer is composed of a liquid crystal compound and, if necessary, a polymerization initiator, an average inclination angle adjusting agent, and optional additives (eg, plasticizer, monomer, surfactant, alignment temperature lowering agent, chiral agent). It can form by apply | coating the coating liquid containing this on an alignment film.

(Polymerization initiator)
The aligned liquid crystalline compound can be fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred.
Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).

The amount of the photopolymerization initiator used is preferably in the range of 0.01 to 20% by mass, more preferably in the range of 0.5 to 5% by mass, based on the solid content of the coating solution.
Light irradiation for the polymerization of the liquid crystalline compound is preferably performed using ultraviolet rays.
The irradiation energy is preferably in the range of 20 mJ / cm ² to 50 J / cm ^2, more preferably in the range of 20 to 5000 mJ / cm ^2, and still more preferably in the range of 100 to 800 mJ / cm ² . In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

(Average tilt angle control agent)
In the optically anisotropic layer of the present invention, the average tilt angle of the liquid crystal compound can be adjusted by a compound having a specific surface activity.
Examples of the compound that lowers the average inclination angle include a lower fatty acid ester of cellulose, a fluorine-containing surfactant, or a compound having a 1,3,5-triazine ring.

(Lower fatty acid ester of cellulose)
The “lower fatty acid” in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. The number of carbon atoms is preferably 2 to 5, and more preferably 2 to 4. A substituent (eg, hydroxy) may be bonded to the fatty acid. Two or more kinds of fatty acids may form an ester with cellulose. Examples of lower fatty acid esters of cellulose include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose hydroxypropionate, cellulose acetate propionate and cellulose acetate butyrate. Cellulose acetate butyrate is particularly preferred. The degree of butyrylation of cellulose acetate butyrate is preferably 30% or more, and more preferably 30 to 80%. The degree of acetylation of cellulose acetate butyrate is preferably 30% or less, and more preferably 1 to 30%. The lower fatty acid ester of cellulose is used in an amount of 0.01 to 1% by weight of the amount of the liquid crystal compound.
The amount used is preferably 0.1 to 1% by weight, more preferably 0.3 to 0.9% by weight, based on the amount of the liquid crystal compound.

  The compound having a 1,3,5-triazine ring is preferably a compound represented by the following formula (III).

In the formula, X ¹ , X ² and X ³ are each independently a single bond, —NR— (R is an alkyl group having 1 to 30 carbon atoms or a hydrogen atom), —O— or —S—. And R ³¹ , R ³² and R ³³ are each independently an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. The compound represented by the formula (III) is particularly preferably a melamine compound. In the melamine compound, in the formula (III), X ¹ , X ² or X ³ is —NR—, or X ¹ , X ² or X ³ is a single bond, and R ³¹ , R ³² and R 3 ³³ is a heterocyclic group having a free valence on the nitrogen atom. The melamine compound will be described in more detail with reference to the following formula (IV). R in —NR— is particularly preferably a hydrogen atom. R ³¹ , R ³² and R ³³ are particularly preferably an aryl group.

  The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. A linear alkyl group is preferred to a branched alkyl group. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 2 to 30 carbon atoms, still more preferably 4 to 30 carbon atoms, and most preferably 6 to 30 carbon atoms. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy). The alkenyl group is preferably a chain alkenyl group rather than a cyclic alkenyl group. A linear alkenyl group is preferable to a branched chain alkenyl group. The alkenyl group preferably has 2 to 30 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 4 to 30 carbon atoms, and most preferably 6 to 30 carbon atoms. The alkenyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy).

  The aryl group is preferably phenyl or naphthyl, and particularly preferably phenyl. The aryl group may have a substituent. Examples of the substituent include a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxycarbonyl group, Aryloxycarbonyl group, sulfamoyl, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamido group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio group, alkenyl A thio group, an arylthio group and an acyl group are included. The alkyl group has the same definition as the alkyl group described above. The alkyl part of the alkoxy group, the acyloxy group, the alkoxycarbonyl group, the alkyl-substituted sulfamoyl group, the sulfonamide group, the alkyl-substituted carbamoyl group, the amide group, the alkylthio group and the acyl group is the same as the alkyl group described above. The alkenyl group has the same definition as the alkenyl group described above. The alkenyl part of the alkenyloxy group, acyloxy group, alkenyloxycarbonyl group, alkenyl-substituted sulfamoyl group, sulfonamide group, alkenyl-substituted carbamoyl group, amide group, alkenylthio group and acyl group is the same as the alkenyl group described above. Examples of the aryl group include phenyl, α-naphthyl, β-naphthyl, 4-methoxyphenyl, 3,4-diethoxyphenyl, 4-octyloxyphenyl and 4-dodecyloxyphenyl. Examples of the aryloxy group, acyloxy group, aryloxycarbonyl group, aryl-substituted sulfamoyl group, sulfonamido group, aryl-substituted carbamoyl group, amide group, arylthio group, and acyl group are the same as the above examples of the aryl group.

When X ¹ , X ² or X ³ is —NR—, —O— or —S—, the heterocyclic group preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably N, S or O, and particularly preferably N. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety. When X ¹ , X ² or X ³ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. In addition, the heterocyclic group may have a hetero atom other than the nitrogen atom (eg, O, S). The heterocyclic group may have a substituent.
Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety. Examples of heterocyclic groups having free valences on nitrogen atoms are shown below.

At least one of R ³¹ , R ³² and R ³³ preferably contains an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group. Further, at least one of R ³¹ , R ³² and R ³³ preferably has a polymerizable group as a substituent. The compound having a 1,3,5-triazine ring preferably has at least two polymerizable groups. The polymerizable group is preferably located at the end of R ³¹ , R ³² or R ³³ . By introducing a polymerizable group into a compound having a 1,3,5-triazine ring, an optically anisotropic compound in a state where the compound having a 1,3,5-triazine ring and a discotic liquid crystalline molecule are polymerized. It can be included in the sex layer. R ³¹ , R ³² or R ³³ having a polymerizable group as a substituent is represented by the following formula (Rp).

(Rp) -L5 (-P) n
In the formula, L5 is an (n + 1) -valent linking group; P is a polymerizable group; and n is an integer of 1 to 5. In the formula (Rp), the (n + 1) -valent linking group (L5) is an alkylene group, an alkenylene group, an n + 1-valent aromatic group, a divalent heterocyclic residue, -CO-, -NR- (R is carbon. It is preferably a linking group in which at least two groups selected from the group consisting of an alkyl group having 1 to 30 atoms or a hydrogen atom), —O—, —S— and —SO ₂ — are combined. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The aromatic group preferably has 6 to 10 carbon atoms. An example of L5 in the formula (Rp) is shown below. (If the X ^1, X ² or X ³ of a single bond, directly to 1,3,5-triazine ring) left X ^1, coupled to X ² or X ³ of the formula (III), and right (L53 It binds to n polymerizable groups (P) in .about.L59. AL represents an alkylene group or alkenylene group, Hc represents a divalent heterocyclic residue, and AR represents an aromatic group. The alkylene group, alkenylene group, heterocyclic residue and aromatic group may have a substituent (eg, alkyl group, halogen atom).

L51: -AL-O-CO-
L52: -AL-O-
L53: -AR (-O-AL-O-CO-) n
L54: -AR (-O-AL-O-) n
L55: -AR (-O-CO-AL-O-CO-) n
L56: -AR (-CO-O-AL-O-CO-) n
L57: -AR (-O-CO-AR-O-AL-O-CO-) n
_{L58: -AR (-NR-SO 2} -AL-O-CO-) n
_{L59: -AR (-SO 2 -NR-} AL-O-CO-) n

  As the polymerizable group (P) in the formula (Rp), the following structures can be preferably used.

  The polymerizable group (P) is preferably an unsaturated polymerizable group (P1, P2, P3, P7, P8, P15, P16, P17) or an epoxy group (P6, P18). More preferably, it is most preferably an ethylenically unsaturated polymerizable group (P1, P7, P8, P15, P16, P17). In the formula (Rp), n is an integer of 4 to 12. Specific numbers are determined according to the type of liquid crystal compound.

  Specific examples of compounds having a 1,3,5-triazine ring (excluding melamine compounds) are shown below.

TR-1: R ³¹ , R ³² , R ³³ :-( CH ₂ ) ₉ -O-CO-CH = CH ₂
TR-2: R ³¹ , R ³² , R ³³ :-( CH ₂ ) ₄ —CH═CH— (CH ₂ ) ₄ —O—CO—CH═CH ₂
^{TR-3: R 31, R} 32 :-( CH 2) 9 -O-CO-CH = CH 2; R 33 :-( CH 2) 12 -CH 3
^{TR-4: R 31, R} 32 :-( CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 33 :-( CH 2) 12 -CH 3
^{TR-5: R 31 :-( CH} 2) 9 -O-CO-CH = CH 2; R 32, R 33 :-( CH 2) 12 -CH 3
^{TR-6: R 31 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 32, R 33 :-( CH 2) 12 -CH 3
^{TR-7: R 31, R} 32 :-( CH 2) 4 -O-CO-CH = CH 2; R 33 :-( CH 2) 12 -CH 3
^{TR-8: R 31 :-( CH} 2) 4 -O-CO-CH = CH 2; R 32, R 33 :-( CH 2) 12 -CH 3
TR-9: R ³¹ , R ³² , R ³³ :-( CH ₂ ) ₉ -O-EpEt
TR-10: R ³¹ , R ³² , R ³³ :-( CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -O-EpEt
TR-11: R ³¹ , R ³² :-( CH ₂ ) ₉ -O-EpEt; R ³³ :-( CH ₂ ) ₁₂ -CH ₃
TR-12: R ³¹ , R ³² , R ³³ :-( CH ₂ ) ₉ -O-CH = CH ₂
^{TR-13: R 31, R} 32 :-( CH 2) 9 -O-CH = CH 2; R 33 :-( CH 2) 12 -CH 3
(Ii) EpEt: Epoxyethyl

^{TR-14: X 1, X} 2, X 3: -O-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CO-CH = CH 2
^{TR-15: X 1, X} 2, X 3: -O-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 9 -O-CO-CH = CH ₂
^{TR-16: X 1, X} 2, X 3: -O-; R 32, R 35, R 38: -O- (CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH ₂
^{TR-17: X 1, X} 2, X 3: -O-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 4 -CH = CH- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{TR-18: X 1, X} 2, X 3: -O-; R 31, R 33, R 34, R 36, R 37, R 39: -O- (CH 2) 9 -O-CO-CH = CH ₂
^{TR-19: X 1, X} 2, X 3: -O-; R 31, R 32, R 33, R 34, R 35, R 36, R 37, R 38, R 39: -O- (CH 2 ) ₉ -O-CO-CH = CH ₂
^{TR-20: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CO-CH = CH 2
TR-21: X ¹ , X ² : —O—; X ³ : —NH—; R ³² , R ³⁵ : —O— (CH ₂ ) ₄ —O—CO—CH═CH ₂ ; R ³⁸ : —O -(CH ₂ ) ₁₂ -CH ₃
^{TR-22: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-CO-CH = CH 2; R 37, R 38 : -O- (CH ₂ ) ₁₂ -CH ₃
TR-23: X ¹ , X ² : —O—; X ³ : —NH—; R ³² , R ³⁵ : —O— (CH ₂ ) ₄ —O—CO—CH═CH ₂ ; R ³⁸ : —O -CO- (CH ₂ ) ₁₁ -CH ₃
TR-24: X ¹ : -O-; X ² , X ³ : -NH-; R ³¹ , R ³³ : -O- (CH ₂ ) ₁₂ -CH ₃ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
TR-25: X ¹ : —O—; X ² , X ³ : —NH—; R ³¹ , R ³² : —O— (CH ₂ ) ₆ —O—CO—CH═CH ₂ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₁₁ -CH ₃
TR-26: X ¹ : —O—; X ² , X ³ : —NH—; R ³¹ , R ³² , R ³³ : —O— (CH ₂ ) ₆ —O—CO—CH═CH ₂ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₁₁ -CH ₃

TR-27: X ¹ , X ² : —NH—; X ³ : —S—; R ³² , R ³⁵ : —O— (CH ₂ ) ₉ —O—CO—CH═CH ₂ ; R ³⁸ : —O -CO- (CH ₂ ) ₁₁ -CH ₃
^{TR-28: X 1, X} 2: -NH-; X 3: -S-; R 31, R 32, R 34, R 35: -O- (CH 2) 9 -O-CO-CH = CH 2 ; R ³⁸ : -O-CO- (CH ₂ ) ₁₁ -CH ₃
TR-29: X ¹ , X ² : —NH—; X ³ : —S—; R ³² , R ³⁵ : —O— (CH ₂ ) ₄ —CH═CH— (CH ₂ ) ₄ —O—CO— CH = CH ₂ ; R ³⁸ : -O-CO- (CH ₂ ) ₁₁ -CH ₃
^{TR-30: X 1, X} 2: -NH-; X 3: -S-; R 31, R 32, R 34, R 35: -O- (CH 2) 4 -CH = CH- (CH 2) ₄ -O-CO-CH = CH ₂ ; R ³⁸ : -O-CO- (CH ₂ ) ₁₁ -CH ₃
^{TR-31: X 1, X} 2: -NH-; X 3: -S-; R 31, R 33, R 34, R 36: -O- (CH 2) 9 -O-CO-CH = CH 2 ; R ³⁸ : -O-CO- (CH ₂ ) ₁₁ -CH ₃
^{TR-32: X 1, X} 2: -NH-; X 3: -S-; R 31, R 32, R 33, R 34, R 35, R 36: -O- (CH 2) 9 -O- CO-CH = CH ₂ ; R ³⁸ : -O-CO- (CH ₂ ) ₁₁ -CH ₃
^{TR-33: X 1, X} 2: -O-; X 3: -S-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CO-CH = CH 2
^{TR-34: X 1, X} 2: -O-; X 3: -S-; R 32, R 35: -O- (CH 2) 4 -O-CO-CH = CH 2; R 38: -O -(CH ₂ ) ₁₂ -CH ₃
^{TR-35: X 1, X} 2: -O-; X 3: -S-; R 32, R 35: -O- (CH 2) 4 -O-CO-CH = CH 2; R 37, R 38 : -O- (CH ₂ ) ₁₂ -CH ₃
TR-36: X ¹ , X ² : -O-; X ³ : -S-; R ³² , R ³⁵ : -O- (CH ₂ ) ₄ -O-CO-CH = CH ₂ ; R ³⁸ : -O -CO- (CH ₂ ) ₁₁ -CH ₃
TR-37: X ¹ : -O-; X ² , X ³ : -S-; R ³¹ , R ³³ : -O- (CH ₂ ) ₁₂ -CH ₃ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
TR-38: X ¹ : —O—; X ² , X ³ : —S—; R ³¹ , R ³² : —O— (CH ₂ ) ₆ —O—CO—CH═CH ₂ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₁₁ -CH ₃
TR-39: X ¹ : -O-; X ² , X ³ : -S-; R ³¹ , R ³² , R ³³ : -O- (CH ₂ ) ₆ -O-CO-CH = CH ₂ ; R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₁₁ -CH ₃

^{TR-40: X 1, X} 2, X 3: -S-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CO-CH = CH 2
^{TR-41: X 1, X} 2, X 3: -S-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 9 -O-CO-CH = CH ₂
^{TR-42: X 1, X} 2, X 3: -S-; R 32, R 35, R 38: -O- (CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH ₂
^{TR-43: X 1, X} 2, X 3: -S-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 4 -CH = CH- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{TR-44: X 1, X} 2, X 3: -S-; R 31, R 33, R 34, R 36, R 37, R 39: -O- (CH 2) 9 -O-CO-CH = CH ₂
^{TR-45: X 1, X} 2, X 3: -S-; R 31, R 32, R 33, R 34, R 35, R 36, R 37, R 38, R 39: -O- (CH 2 ) ₉ -O-CO-CH = CH ₂
^{TR-46: X 1, X} 2: -S-; X 3: -NH-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CO-CH = CH 2
TR-47: X ¹ , X ² : —S—; X ³ : —NH—; R ³² , R ³⁵ : —O— (CH ₂ ) ₄ —O—CO—CH═CH ₂ ; R ³⁸ : —O -(CH ₂ ) ₁₂ -CH ₃
^{TR-48: X 1, X} 2: -S-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-CO-CH = CH 2; R 37, R 38 : -O- (CH ₂ ) ₁₂ -CH ₃
^{TR-49: X 1, X} 2: -S-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-CO-CH = CH 2; R 38: -O -CO- (CH ₂ ) ₁₁ -CH ₃
TR-50: X ¹ : -O-; X ² : -NH-; X ³ : -S-; R ³¹ , R ³³ : -O- (CH ₂ ) ₁₂ -CH ₃ ; R ³⁵ : -O- ( CH ₂ ) ₉ -O-CO-CH = CH ₂ ; R ³⁸ : -O- (CH ₂ ) ₁₂ -CH ₃
TR-51: X ¹ : -O-; X ² : -NH-; X ³ : -S-; R ³¹ , R ³² : -O- (CH ₂ ) ₆ -O-CO-CH = CH ₂ ; R ³⁵ : -O- (CH ₂ ) ₁₁ -CH ₃ ; R ³⁸ : -O- (CH ₂ ) ₁₂ -CH ₃
TR-52: X ¹ : -O-; X ² : -NH-; X ³ : -S-; R ³¹ , R ³² , R ³³ : -O- (CH ₂ ) ₆ -O-CO-CH = CH ₂ ; R ³⁵ : -O- (CH ₂ ) ₁₁ -CH ₃ ; R ³⁸ : -O- (CH ₂ ) ₁₂ -CH ₃

^{TR-53: X 1, X} 2, X 3: -O-; R 32, R 35, R 38: -O- (CH 2) 9 -O-EpEt
^{TR-54: X 1, X} 2, X 3: -O-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 9 -O-EpEt
^{TR-55: X 1, X} 2, X 3: -O-; R 32, R 35, R 38: -O- (CH 2) 4 -CH = CH- (CH 2) 4 -O-EpEt
^{TR-56: X 1, X} 2, X 3: -O-; R 31, R 32, R 34, R 35, R 37, R 38: -O- (CH 2) 4 -CH = CH- (CH ₂ ) ₄ -O-EpEt
^{TR-57: X 1, X} 2, X 3: -O-; R 31, R 33, R 34, R 36, R 37, R 39: -O- (CH 2) 9 -O-EpEt
^{TR-58: X 1, X} 2, X 3: -O-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CH = CH 2
TR-59: X ¹ , X ² : -O-; X ³ : -NH-; R ³² , R ³⁵ , R ³⁸ : -O- (CH ₂ ) ₉ -O-EpEt
^{TR-60: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-EpEt; R 38: -O- (CH 2) ₁₂ -CH ₃
^{TR-61: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-EpEt; R 37, R 38: -O- ( CH ₂ ) ₁₂ -CH ₃
^{TR-62: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35: -O- (CH 2) 4 -O-EpEt; R 38: -O-CO- (CH ₂ ) ₁₁ -CH ₃
TR-63: X ¹ : —O—; X ² , X ³ : —NH—; R ³¹ , R ³³ : —O— (CH ₂ ) ₁₂ —CH ₃ ; R ³⁵ , R ³⁸ : —O— (CH ₂ ) ₉ -O-EpEt
TR-64: X ¹ : -O-; X ² , X ³ : -NH-; R ³¹ , R ³² : -O- (CH ₂ ) ₆ -O-EpEt; R ³⁵ , R ³⁸ : -O- ( CH ₂ ) ₁₁ -CH ₃
^{TR-65: X 1, X} 2: -O-; X 3: -NH-; R 32, R 35, R 38: -O- (CH 2) 9 -O-CH = CH 2
(Ii) R not defined: unsubstituted (hydrogen atom)
EpEt: Epoxy ethyl

  The compound having a 1,3,5-triazine ring is preferably a melamine compound represented by the following formula (IV).

In the formula, R ⁴¹ , R ⁴³ and R ⁴⁵ are each independently an alkyl group having 1 to 30 carbon atoms or a hydrogen atom, and R ⁴² , R ⁴⁴ and R ⁴⁶ are each independently an alkyl group, alkenyl A group, an aryl group or a heterocyclic group, or R ⁴¹ and R ⁴² , R ⁴³ and R ⁴⁴ or R ⁴⁵ and R ⁴⁶ are combined to form a heterocyclic ring. R ⁴¹ , R ⁴³ and R 45 are preferably an alkyl group having 1 to 20 carbon atoms or a hydrogen atom, more preferably an alkyl group having 1 to 10 carbon atoms or a hydrogen atom, It is more preferably an alkyl group having a number of 1 to 6 or a hydrogen atom, and most preferably a hydrogen atom. R ⁴² , R ⁴⁴ and R ⁴⁶ are particularly preferably an aryl group. The definitions and substituents of the alkyl group, alkenyl group, aryl group and heterocyclic group are the same as the definitions and substituents of each group described in the formula (III). The heterocyclic ring formed by combining R ⁴¹ and R ⁴² , R ⁴³ and R ⁴⁴ or R ⁴⁵ and R ⁴⁶ is the same as the heterocyclic group having a free valence on the nitrogen atom described in the above formula (III). .

At least one of R ⁴² , R ⁴⁴ and R ⁴⁶ preferably contains an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group. In addition, at least one of R ⁴² , R ⁴⁴ and R ⁴⁶ preferably has a polymerizable group as a substituent. The melamine compound preferably has at least two polymerizable groups. The polymerizable group is preferably located at the terminal of R ⁴² , R ⁴⁴ and R ⁴⁶ . By introducing a polymerizable group into the melamine compound, it can be included in the optically anisotropic layer in a state where the melamine compound and the liquid crystalline compound are polymerized. R ⁴² , R ⁴⁴ and R ⁴⁶ having a polymerizable group as a substituent are the same as the group represented by the aforementioned formula (Rp).

  Specific examples of the melamine compound are shown below.

MM-1: R ⁴³ , R ⁴⁴ , R ⁵³ , R ⁵⁴ , R ⁶³ , R ⁶⁴ : -O- (CH ₂ ) ₉ -CH ₃
^{MM-2: R 43, R} 44, R 53, R 54, R 63, R 64: -O- (CH 2) 11 -CH 3 MM-3: R 43, R 44, R 53, R 54, R ⁶³ , R ⁶⁴ : -O- (CH ₂ ) ₁₅ -CH ₃
MM-4: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₉ -CH ₃
MM-5: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₁₅ -CH ₃
MM-6: R ⁴³ , R ⁵³ , R ⁶³ : -O-CH ₃ ; R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₁₇ -CH ₃
MM-7: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -CO-O- (CH ₂ ) ₁₁ -CH ₃
^{MM-8: R 44, R} 54, R 64: -SO 2 -NH- (CH 2) 17 -CH 3
MM-9: R ⁴³ , R ⁵³ , R ⁶³ : -O-CO- (CH ₂ ) ₁₅ -CH ₃
MM-10: R ⁴² , R ⁵² , R ⁶² : -O- (CH ₂ ) ₁₇ -CH ₃
^{MM-11: R 42, R} 52, R 62: -O-CH 3; R 43, R 53, R 63: -CO-O- (CH 2) 11 -CH 3
MM-12: R ⁴² , R ⁵² , R ⁶² : -Cl; R ⁴³ , R ⁵³ , R ⁶³ : -CO-O- (CH ₂ ) ₁₁ -CH ₃
^{MM-13: R 42, R} 52, R 62: -O- (CH 2) 11 -CH 3; R 45, R 55, R 65: -SO 2 -NH-iso-C 3 H 7
^{MM-14: R 42, R} 52, R 62: -Cl; R 45, R 55, R 65: -SO 2 -NH- (CH 2) 15 -CH 3
^{MM-15: R 42, R} 46, R 52, R 56, R 62, R 66: -Cl; R 45, R 55, R 65: -SO 2 -NH- (CH 2) 19 -CH 3
^{MM-16: R 43, R} 54: -O- (CH 2) 9 -CH 3; R 44, R 53, R 63, R 64: -O- (CH 2) 11 -CH 3
MM-17: R ⁴⁴ : -O- (CH ₂ ) ₁₁ -CH ₃ ; R ⁵⁴ : -O- (CH ₂ ) ₁₅ -CH ₃ ; R ⁶⁴ : -O- (CH ₂ ) ₁₇ -CH ₃
^{MM-18: R 42, R} 45, R 52, R 55, R 62, R 65: -O-CH 3; R 44, R 54, R 64: -NH-CO- (CH 2) 14 -CH 3
^{MM-19: R 42, R} 45, R 52, R 55, R 62, R 65: -O- (CH 2) 3 -CH 3; R 44, R 54, R 64: -O- (CH 2) ₁₅ -CH ₃
^{MM-20: R 42, R} 52, R 62: -NH-SO 2 - (CH 2) 15 -CH 3; R 44, R 45, R 54, R 55, R 64, R 65: -Cl
^{MM-21: R 42, R} 43, R 52, R 53, R 62, R 63: -F; R 44, R 54, R 64: -CO-NH- (CH 2) 15 -CH 3; R 45 , R ⁴⁶ , R ⁵⁵ , R ⁵⁶ , R ⁶⁵ , R ⁶⁶ : -Cl
^{MM-22: R 42, R} 52, R 62: -Cl; R 44, R 54, R 64: -CH 3; R 45, R 55, R 65: -NH-CO- (CH 2) 12 -CH _Three
MM-23: R ⁴² , R ⁵² , R ⁶² : -OH; R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -CH ₃ ; R ⁴⁵ , R ⁵⁵ , R ⁶⁵ : -O- (CH ₂ ) ₁₅ -CH ₃
^{MM-24: R 42, R} 45, R 52, R 55, R 62, R 65: -O-CH 3; R 44, R 54, R 64 :-( CH 2) 11 -CH 3
^{MM-25: R 42, R} 52, R 62: -NH-SO 2 -CH 3; R 45, R 55, R 65: -CO-O- (CH 2) 11 -CH 3
^{MM-26: R 42, R} 52, R 62: -S- (CH 2) 11 -CH 3; R 45, R 55, R 65: -SO 2 -NH 2

MM-27: R ⁴³ , R ⁴⁴ , R ⁵³ , R ⁵⁴ , R ⁶³ , R ⁶⁴ : -O- (CH ₂ ) ₁₂ -O-CO-CH = CH ₂
MM-28: R ⁴³ , R ⁴⁴ , R ⁵³ , R ⁵⁴ , R ⁶³ , R ⁶⁴ : -O- (CH ₂ ) ₈ -O-CO-CH = CH ₂
^{MM-29: R 43, R} 44, R 53, R 54, R 63, R 64: -O-CO- (CH 2) 7 -O-CO-CH = CH 2
MM-30: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -CO-O- (CH ₂ ) ₁₂ -O-CO-C (CH ₃ ) = CH ₂
MM-31: R ⁴³ , R ⁴⁴ , R ⁵³ , R ⁵⁴ , R ⁶³ , R ⁶⁴ : -O-CO-p-Ph-O- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{MM-32: R 42, R} 44, R 52, R 54, R 62, R 64: -NH-SO 2 - (CH 2) 8 -O-CO-CH = CH 2; R 45, R 55, R ⁶⁵ : -Cl
^{MM-33: R 42, R} 52, R 62: -NH-SO 2 -CH 3; R 45, R 55, R 65: -CO-O- (CH 2) 12 -O-CO-CH = CH 2
MM-34: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂

^{MM-35: R 43, R} 44, R 53, R 54, R 63, R 64: -O- (CH 2) 9 -O-CO-CH = CH 2
MM-36: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{MM-37: R 43, R} 44, R 53, R 54, R 63, R 64: -O- (CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2
^{MM-38: R 43, R} 45, R 53, R 55, R 63, R 65: -O- (CH 2) 9 -O-CO-CH = CH 2
MM-39: R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁶³ , R ⁶⁴ , R ⁶⁵ : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
^{MM-40: R 44, R} 54: -O- (CH 2) 4 -O-CO-CH = CH 2; R 64: -O- (CH 2) 9 -O-CO-CH = CH 2
MM-41: R ⁴⁴ , R ⁵⁴ : -O- (CH ₂ ) ₄ -O-CO-CH = CH ₂ ; R ⁶⁴ : -O- (CH ₂ ) ₁₂ -CH ₃
MM-42: R ⁴⁴ , R ⁵⁴ : -O- (CH ₂ ) ₄ -O-CO-CH = CH ₂ ; R ⁶³ , R ⁶⁴ : -O- (CH ₂ ) ₁₂ -CH ₃
^{MM-43: R 44, R} 54: -O- (CH 2) 4 -O-CO-CH = CH 2; R 63, R 64: -O-CO- (CH 2) 11 -CH 3
MM-44: R ⁴³ , R ⁴⁵ : -O- (CH ₂ ) ₁₂ -CH ₃ ; R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
MM-45: R ⁴³ , R ⁴⁴ : -O- (CH ₂ ) ₆ -O-CO-CH = CH ₂ ; R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₁₁ -CH ₃
MM-46: R ⁴³ , R ⁴⁴ , R ⁴⁵ : -O- (CH ₂ ) ₆ -O-CO-CH = CH ₂ ; R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₁₁ -CH ₃
(Ii) R not defined: unsubstituted (hydrogen atom)
p-Ph: p-phenylene

MM-47: R ⁴⁶ , R ⁵⁶ , R ⁶⁶ : —SO ₂ —NH— (CH ₂ ) ₁₅ —CH ₃ ; R ⁴⁸ , R ⁵⁸ , R ⁶⁸ : —O— (CH ₂ ) ₁₁ —CH ₃
^{MM-48: R 45, R} 55, R 65: -SO 2 -NH- (CH 2) 17 -CH 3
MM-49: R ⁴⁶ , R ⁵⁶ , R ⁶⁶ : -SO ₂ —NH— (CH ₂ ) ₁₅ —CH ₃
^{MM-50: R 45, R} 55, R 65: -O- (CH 2) 17 -CH 3; R 47, R 57, R 67: -SO 2 -NH-CH 3
MM-51: R ⁴³ , R ⁵³ , R ⁶³ : -O- (CH ₂ ) ₁₅ -CH ₃
MM-52: R ⁴¹ , R ⁵¹ , R ⁶¹ : -O- (CH ₂ ) ₁₇ -CH ₃
^{MM-53: R 46, R} 56, R 66: -SO 2 -NH-Ph; R 48, R 58, R 68: -O- (CH 2) 11 -CH 3
^{MM-54: R 45, R} 55, R 65: -O- (CH 2) 21 -CH 3; R 47, R 57, R 67: -SO 2 -NH-Ph
MM-55: R ⁴¹ , R ⁵¹ , R ⁶¹ : -p-Ph- (CH ₂ ) ₁₁ -CH ₃
MM-56: R ⁴⁶ , R ⁴⁸ , R ⁵⁶ , R ⁵⁸ , R ⁶⁶ , R ⁶⁸ : —SO ₂ —NH— (CH ₂ ) ₇ —CH ₃
MM-57: R ⁴⁶ , R ⁵⁶ , R ⁶⁶ : -SO ₂ —NH— (CH ₂ ) ₁₀ —O—CO—CH═CH ₂ ; R ⁴⁸ , R ⁵⁸ , R ⁶⁸ : —O— (CH ₂ ) ₁₂ -CH ₃
^{MM-58: R 45, R} 55, R 65: -O- (CH 2) 12 -O-CO-CH = CH 2; R 47, R 57, R 67: -SO 2 -NH-Ph
MM-59: R ⁴³ , R ⁵³ , R ⁶³ : -O- (CH ₂ ) ₁₆ -O-CO-CH = CH ₂
(Ii) R not defined: unsubstituted (hydrogen atom)
Ph: Phenyl
p-Ph: p-phenylene

MM-60: R ⁴⁵ , R ⁵⁵ , R ⁶⁵ : -NH-CO- (CH ₂ ) ₁₄ -CH ₃
MM-61: R ⁴² , R ⁵² , R ⁶² : -O- (CH ₂ ) ₁₇ -CH ₃
MM-62: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -O- (CH ₂ ) ₁₅ -CH ₃
^{MM-63: R 45, R} 55, R 65: -SO 2 -NH- (CH 2) 15 -CH 3
^{MM-64: R 43, R} 53, R 63: -CO-NH- (CH 2) 17 -CH 3; R 44, R 54, R 64: -OH
^{MM-65: R 45, R} 55, R 65: -O- (CH 2) 15 -CH 3; R 46, R 56, R 66: -SO 2 -NH- (CH 2) 11 -CH 3
MM-66: R ⁴⁷ , R ⁵⁷ , R ⁶⁷ : -O- (CH ₂ ) ₂₁ -CH ₃
MM-67: R ⁴⁴ , R ⁵⁴ , R ⁶⁴ : -Op-Ph- (CH ₂ ) ₁₁ -CH ₃
MM-68: R ⁴⁶ , R ⁵⁶ , R ⁶⁶ : -SO ₂ —NH— (CH ₂ ) ₁₅ —CH ₃
^{MM-69: R 43, R} 53, R 63: -CO-NH- (CH 2) 17 -CH 3; R 44, R 54, R 64: -O- (CH 2) 12 -O-CO-CH = CH ₂
MM-70: R ⁴⁵ , R ⁵⁵ , R ⁶⁵ : —O— (CH ₂ ) ₈ —O—CO—CH═CH ₂ ; R ⁴⁶ , R ⁵⁶ , R ⁶⁶ : —SO ₂ —NH— (CH ₂ ) ₁₁ -CH ₃
MM-71: R ⁴³ , R ⁴⁶ , R ⁵³ , R ⁵⁶ , R ⁶³ , R ⁶⁶ : -SO ₂ -NH- (CH ₂ ) ₈ -0-CO-CH = CH ₂
(Ii) R not defined: unsubstituted (hydrogen atom)
p-Ph: p-phenylene

MM-72: R ⁴¹ , R ⁴³ , R ⁴⁵ : -CH ₃
MM-73: R ⁴¹ , R ⁴³ , R ⁴⁵ : -C ₂ H ₅
MM-74: R ⁴¹ , R ⁴³ : -C ₂ H ₅ ; R ⁴⁵ : -CH ₃
MM-75: R ⁴¹ , R ⁴³ , R ⁴⁵ :-( CH ₂ ) ₃ -CH ₃

MM-76: R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₉ -O-CO-CH = CH ₂
MM-77: R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -O-CO-CH = CH ₂
MM-78: R ⁴² , R ⁴⁴ :-( CH ₂ ) ₉ -O-CO-CH = CH ₂ ; R ⁴⁶ :-( CH ₂ ) ₁₂ -CH ₃
^{MM-79: R 42, R} 44 :-( CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 46 :-( CH 2) 12 -CH 3
^{MM-80: R 42 :-( CH} 2) 9 -O-CO-CH = CH 2; R 44, R 46 :-( CH 2) 12 -CH 3
^{MM-81: R 42 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 44, R 46 :-( CH 2) 12 -CH 3
MM-82: R ⁴² , R ⁴⁴ :-( CH ₂ ) ₄ -O-CO-CH = CH ₂ ; R ⁴⁶ :-( CH ₂ ) ₁₂ -CH ₃
^{MM-83: R 42 :-( CH} 2) 4 -O-CO-CH = CH 2; R 44, R 46 :-( CH 2) 12 -CH 3
MM-84: R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₉ -O-EpEt
MM-85: R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -O-EpEt
MM-86: R ⁴² , R ⁴⁴ :-( CH ₂ ) ₉ -O-EpEt; R ⁴⁶ :-( CH ₂ ) ₁₂ -CH ₃
MM-87: R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₉ -O-CH = CH ₂
MM-88: R ⁴² , R ⁴⁴ :-( CH ₂ ) ₉ -O-CH = CH ₂ ; R ⁴⁶ :-( CH ₂ ) ₁₂ -CH ₃
(Ii) EpEt: Epoxyethyl

MM-89: R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ :-( CH ₂ ) ₉ -CH ₃
MM-90: R ⁴¹ , R ⁴³ , R ⁴⁵ : -CH ₃ ; R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₁₇ -CH ₃
MM-91: R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ :-( CH ₂ ) ₇ -CH ₃ ; R ⁴⁵ , R ⁴⁶ :-( CH ₂ ) ₅ -CH ₃
MM-92: R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ : -CyHx
MM-93: R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ :-( CH ₂ ) ₂ —OC ₂ H ₅
MM-94: R ⁴¹ , R ⁴³ , R ^{45: -CH} ₃ ; R ⁴² , R ⁴⁴ , R ⁴⁶ :-( CH ₂ ) ₁₂ -O-CO-CH = CH ₂
MM-95: R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ :-( CH ₂ ) ₈ -O-CO-CH = CH ₂
(Ii) CyHx: cyclohexyl

  A melamine polymer may be used as the melamine compound. The melamine polymer is preferably synthesized by a polymerization reaction between a melamine compound represented by the following formula (V) and a carbonyl compound.

In the formula, R ⁷¹ , R ⁷² , R ⁷³ , R ⁷⁴ , R ⁷⁵ and R ⁷⁶ are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. The definitions and substituents of the alkyl group, alkenyl group, aryl group and heterocyclic group are the same as the definitions and substituents of each group described in the formula (III). The polymerization reaction between the melamine compound and the carbonyl compound is the same as the method for synthesizing a normal melamine resin (eg, melamine formaldehyde resin). A commercially available melamine polymer (melamine resin) may be used. The molecular weight of the melamine polymer is preferably 2,000 or more and 400,000 or less.

At least one of R ⁷¹ , R ⁷² , R ⁷³ , R ⁷⁴ , R ⁷⁵ and R ⁷⁶ preferably contains an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group. Moreover, it is preferable that at least one of R ⁷¹ , R ⁷² , R ⁷³ , R ⁷⁴ , R ⁷⁵ and R ⁷⁶ has a polymerizable group as a substituent. The polymerizable groups are preferably located at the end of ^{R 71, R 72, R 73} , R 74, R 75 and R ^76. By introducing a polymerizable group into the melamine polymer, it can be included in the optically anisotropic layer in a state where the melamine polymer and the liquid crystal compound are polymerized. R ⁷¹ , R ⁷² , R ⁷³ , R ⁷⁴ , R ⁷⁵ and R ⁷⁶ having a polymerizable group as a substituent are the same as the group represented by the above formula (Rp). The polymerizable group may be introduced into one of the carbonyl compound (R ⁷¹ , R ⁷² ) and the melamine compound (R ⁷³ , R ⁷⁴ , R ⁷⁵ , R ⁷⁶ ). When the melamine compound has a polymerizable group, the carbonyl compound is preferably a compound having a simple chemical structure such as formaldehyde. When the carbonyl compound has a polymerizable group, a compound having a simple chemical structure such as (unsubstituted) melamine is preferably used as the melamine compound.

  Examples of carbonyl compounds having a polymerizable group are shown below.

CO-1: R ⁷² : -H; R ⁸² : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
CO-2: R ⁷² : -H; R ⁸¹ , R ⁸² : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
CO-3: R ⁷² : -H; R ⁸² : -O- (CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{CO-4: R 72: -H} ; R 81, R 82: -O- (CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2
^{CO-5: R 72: -H} ; R 81, R 83: -O- (CH 2) 9 -O-CO-CH = CH 2
^{CO-6: R 72: -H} ; R 81, R 82, R 83: -O- (CH 2) 9 -O-CO-CH = CH 2
CO-7: R ⁷² : -CH ₃ ; R ⁸² : -O- (CH ₂ ) ₉ -O-CO-CH = CH ₂
^{CO-8: R 72 :-( CH} 2) 11 -CH 3; R 82: -O- (CH 2) 4 -O-CO-CH = CH 2
^{CO-9: R 72 :-( CH} 2) 9 -O-CO-CH = CH 2; R 82: -O- (CH 2) 4 -O-CO-CH = CH 2
CO-10: R ⁷² :-( CH ₂ ) ₉ -O-CO-EpEt; R ⁸² : -O- (CH ₂ ) ₄ -O-CO-CH = CH ₂
^{CO-11: R 72 :-( CH} 2) 4 -O-CO-CH = CH 2; R 81, R 83: -O- (CH 2) 12 -CH 3
(Ii) R not defined: unsubstituted (hydrogen atom)
EpEt: Epoxy ethyl

^{CO-12: R 81, R} 82, R 83, R 84: -O- (CH 2) 6 -O-CO-CH = CH 2
^{CO-13: R 82, R} 83: -O- (CH 2) 9 -O-CO-CH = CH 2
(Iii) Undefined R: unsubstituted (hydrogen atom)

^{CO-14: R 71 :-( CH} 2) 9 -O-CO-CH = CH 2; R 72: -H
^{CO-15: R 71 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 72: -H
^{CO-16: R 71 :-( CH} 2) 9 -O-CO-CH = CH 2; R 72: -CH 3
^{CO-17: R 71 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 72: -CH 3
^{CO-18: R 71 :-( CH} 2) 9 -O-CO-CH = CH 2; R 72: -Ph
^{CO-19: R 71 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2; R 72: -Ph
^{CO-20: R 71 :-( CH} 2) 4 -O-CO-CH = CH 2; R 72 :-( CH 2) 9 -O-CO-CH = CH 2
^{CO-21: R 71 :-( CH} 2) 4 -O-CO-CH = CH 2; R 72 :-( CH 2) 12 -CH 3
CO-22: R ⁷¹ :-( CH ₂ ) ₉ -O-EpEt; R ⁷² : -H
^{CO-23: R 71 :-( CH} 2) 4 -CH = CH- (CH 2) 4 -O-EpEt; R 72: -H
CO-24: R ⁷¹ , R ⁷² :-( CH ₂ ) ₉ -O-EpEt
^{CO-25: R 71, R} 72 :-( CH 2) 9 -O-CO-CH = CH 2
^{CO-26: R 71, R} 72 :-( CH 2) 4 -CH = CH- (CH 2) 4 -O-CO-CH = CH 2
(註) Ph: Phenyl
EpEt: Epoxy ethyl

  Examples of melamine polymers having a polymerizable group on the melamine compound side are shown below.

^{MP-1: R 73, R} 75, R 76: -CH 2 -NH-CO-CH = CH 2; R 74: -CH 2 -NH-CO- (CH 2) 8 -CH 3
^{MP-2: R 71: -CH} 3; R 73, R 75, R 76: -CH 2 -NH-CO-CH = CH 2; R 74: -CH 2 -NH-CO- (CH 2) 8 - CH ₃
MP-3: R ⁷¹ , R ⁷² : -CH ₃ ; R ⁷³ , R ⁷⁵ , R ⁷⁶ : -CH ₂ -NH-CO-CH = CH ₂ ; R ⁷⁴ : -CH ₂ -NH-CO- (CH ₂ ) ₈ -CH ₃
^{MP-4: R 71: -Ph} ; R 73, R 75, R 76: -CH 2 -NH-CO-CH = CH 2; R 74: -CH 2 -NH-CO- (CH 2) 8 -CH _Three
MP-5: R ⁷³ , R ⁷⁶ : -CH ₂ —NH—CO—CH═CH ₂ ; R ⁷⁴ : —CH ₂ —NH—CO— (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ — CH ₃ ; R ⁷⁵ : -CH ₂ -O-CH ₃
MP-6: R ⁷³ , R ⁷⁶ : —CH ₂ —NH—CO—CH═CH ₂ ; R ⁷⁴ : —CH ₂ —NH—CO— (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ — CH ₃ ; R ⁷⁵ : -CH ₂ -OH
^{MP-7: R 73, R} 76: -CH 2 -NH-CO-C 2 H 5; R 74: -CH 2 -NH-CO- (CH 2) 16 -CH 3; R 75: -CH 2 - O-CH ₃
^{MP-8: R 73, R} 76: -CH 2 -NH-CO-C 2 H 5; R 74: -CH 2 -NH-CO- (CH 2) 16 -CH 3; R 75: -CH 2 - OH
MP-9: R ⁷³ , R ⁷⁶ : —CH ₂ —O—CO—CH═CH ₂ ; R ⁷⁴ : —CH ₂ —O—CO— (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ — CH ₃ ; R ⁷⁵ : -CH ₂ -O-CH ₃
MP-10: R ⁷³ , R ⁷⁶ : —CH ₂ —O—CO—CH═CH ₂ ; R ⁷⁴ : —CH ₂ —O—CO— (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ — CH ₃ ; R ⁷⁵ : -CH ₂ -OH
MP-11: R ⁷³ , R ⁷⁶ : —CH ₂ —O—CO— (CH ₂ ) ₇ —CH═CH— (CH ₂ ) ₇ —CH ₃ ; R ⁷⁴ : —CH ₂ —NH—CO— (CH ₂ ) ₇ -CH = CH- (CH ₂ ) ₇ -CH ₃ ; R ⁷⁵ : -CH ₂ -O-CH ₃
^{MP-12: R 73, R} 76: -CH 2 -O-CO- (CH 2) 7 -CH = CH- (CH 2) 7 -CH 3; R 74: -CH 2 -NH-CO- (CH ₂ ) ₇ -CH = CH- (CH ₂ ) ₇ -CH ₃ ; R ⁷⁵ : -CH ₂ -OH
^{MP-13: R 73, R} 74, R 75, R 76: -CH 2 -O- (CH 2) 11 -O-CO-CH = CH 2
^{MP-14: R 73, R} 75, R 76: -CH 2 -NH-CO-CH = CH 2; R 74: -CH 2 -O- (CH 2) 16 -CH 3
(Ii) R not defined: unsubstituted (hydrogen atom)
Ph: Phenyl

(Fluorine-containing surfactant)
The optically anisotropic layer according to the present invention can align the liquid crystalline compound stably and uniformly by adding a fluorine-containing surfactant.
The fluorine-containing surfactant used in the present invention is composed of a hydrophobic group containing a fluorine atom, a nonionic, anionic, cationic or amphoteric hydrophilic group and an optionally provided linking group. The fluorine-containing surfactant composed of one hydrophobic group and one hydrophilic group is represented by the following formula (II).

(II) Rf-L3 -Hy
In which Rf is a monovalent hydrocarbon residue substituted with a fluorine atom; L3 is a single bond or a divalent linking group; and Hy is a hydrophilic group. Rf in the formula (II) functions as a hydrophobic group. The hydrocarbon residue is preferably an alkyl group or an aryl group. The alkyl group preferably has 3 to 30 carbon atoms, and the aryl group preferably has 6 to 30 carbon atoms. Some or all of the hydrogen atoms contained in the hydrocarbon residue are substituted with fluorine atoms. It is preferable to substitute 50% or more of the hydrogen atoms contained in the hydrocarbon residue with fluorine atoms, more preferably 60% or more, more preferably 70% or more, and more preferably 80% or more. Most preferred is substitution. The remaining hydrogen atoms may be further substituted with other halogen atoms (eg, chlorine atom, bromine atom). An example of Rf is shown below.

Rf1: n-C ₈ F ₁₇ −
_{Rf2: n-C 6 F 13} -
_{Rf3: Cl- (CF 2 -CFCl)} 3 -CF 2 -
_{Rf4: H- (CF 2) 8} -
_{Rf5: H- (CF 2) 10} -
_{Rf6: n-C 9 F 19} -
RF7: pentafluorophenyl _{Rf8: n-C 7 F 15} -
_{Rf9: Cl- (CF 2 -CFCl)} 2 -CF 2 -
_{Rf10: H- (CF 2) 4} -
_{Rf11: H- (CF 2) 6} -
_{Rf12: Cl- (CF 2) 6} -
Rf13: C ₃ F ₇ −

In the formula (II), the divalent linking group is an alkylene group, an arylene group, a divalent heterocyclic residue, -CO-, -NR- (R is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. ), —O—, —SO ₂ —, and combinations thereof, and is preferably a divalent linking group. Examples of L3 in formula (II) are shown below. The left side is bonded to the hydrophobic group (Rf), and the right side is bonded to the hydrophilic group (Hy). AL represents an alkylene group, AR represents an arylene group, and Hc represents a divalent heterocyclic residue. In addition, the alkylene group, the arylene group, and the divalent heterocyclic residue may have a substituent (eg, an alkyl group).

L0: Single bond L31: —SO ₂ —NR—
L32: -AL-O-
L33: -CO-NR-
L34: -AR-O-
_{L35: -SO 2 -NR-AL-} CO-O-
L36: -CO-O-
_{L37: -SO 2 -NR-AL-} O-
L38: -SO ₂ -NR-AL-
L39: -CO-NR-AL-
L40: -AL1 -O-AL2-
L41: -Hc-AL-
_{L42: -SO 2 -NR-AL1 -O} -AL2 -
L43: -AR-
_{L44: -O-AR-SO 2} -NR-AL-
_{L45: -O-AR-SO 2} -NR-
L46: -O-AR-O-

  Hy in the formula (II) is any of a nonionic hydrophilic group, an anionic hydrophilic group, a cationic hydrophilic group, or a combination thereof (an amphoteric hydrophilic group). Nonionic hydrophilic groups are particularly preferred. Examples of Hy in formula (II) are shown below.

_{Hy1 :-( CH 2 CH 2 O)} n -H (n is 5 to 30 integer)
_{Hy2 :-( CH 2 CH 2 O)} n -R1 (n is 5 to 30 integer, R1 is an alkyl group having 1 to 6 carbon atoms)
Hy3: — (CH ₂ CHOHCH ₂ ) n —H (n is an integer of 5 to 30)
Hy4: -COOM (M is a hydrogen atom, an alkali metal atom or a dissociated state)
Hy5: -SO ₃ M (M is a hydrogen atom, an alkali metal atom or dissociated state)
_{Hy6 :-( CH 2 CH 2 O)} n -CH 2 CH 2 CH 2 -SO 3 M (n is 5 to 30 integer, M is a hydrogen atom or an alkali metal atom)
Hy7: -OPO (OH) _{2
Hy8: -N + (CH 3)} 3 · X- (X is a halogen atom)
Hy9: -COONH ₄

  Nonionic hydrophilic groups (Hy1, Hy2, Hy3) are preferred, and hydrophilic groups (Hy1) made of polyethylene oxide are most preferred. Specific examples of the fluorine-containing surfactant represented by the formula (II) will be shown with reference to the above examples of Rf, L3 and Hy.

FS-1: Rf1-L31 ( R = C 3 H 7) -Hy1 (n = 6)
FS-2: Rf1-L31 ( R = C 3 H 7) -Hy1 (n = 11)
FS-3: Rf1-L31 ( R = C 3 H 7) -Hy1 (n = 16)
FS-4: Rf1-L31 ( R = C 3 H 7) -Hy1 (n = 21)
FS-5: Rf1-L31 ( R = C 2 H 5) -Hy1 (n = 6)
FS-6: Rf1-L31 ( R = C 2 H 5) -Hy1 (n = 11)
FS-7: Rf1-L31 ( R = C 2 H 5) -Hy1 (n = 16)
FS-8: Rf1-L31 ( R = C 2 H 7) -Hy1 (n = 21)
FS-9: Rf2-L31 ( R = C 3 H 7) -Hy1 (n = 6)
FS-10: Rf2-L31 ( R = C 3 H 7) -Hy1 (n = 11)
FS-11: Rf2-L31 ( R = C 3 H 7) -Hy1 (n = 16)
FS-12: Rf2-L31 ( R = C 3 H 7) -Hy1 (n = 21)
FS-13: Rf3-L32 ( AL = CH 2) -Hy1 (n = 5)
FS-14: Rf3-L32 ( AL = CH 2) -Hy1 (n = 10)
FS-15: Rf3-L32 ( AL = CH 2) -Hy1 (n = 15)
FS-16: Rf3-L32 ( AL = CH 2) -Hy1 (n = 20)
FS-17: Rf4-L33 ( R = C 3 H 7) -Hy1 (n = 7)
FS-18: Rf4-L33 ( R = C 3 H 7) -Hy1 (n = 13)
FS-19: Rf4-L33 ( R = C 3 H 7) -Hy1 (n = 19)
FS-20: Rf4-L33 ( R = C 3 H 7) -Hy1 (n = 25)
FS-21: Rf5-L32 ( AL = CH 2) -Hy1 (n = 11)

FS-22: Rf5-L32 ( AL = CH 2) -Hy1 (n = 15)
FS-23: Rf5-L32 ( AL = CH 2) -Hy1 (n = 20)
FS-24: Rf5-L32 ( AL = CH 2) -Hy1 (n = 30)
FS-25: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 11)
FS-26: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 17)
FS-27: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 23)
FS-28: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 29)
FS-29: Rf1-L35 ( R = C 3 H 7, AL = CH 2) -Hy1 (n = 20)
FS-30: Rf1-L35 ( R = C 3 H 7, AL = CH 2) -Hy1 (n = 30)
FS-31: Rf1-L35 ( R = C 3 H 7, AL = CH 2) -Hy1 (n = 40)
FS-32: Rf1-L36-Hy1 (n = 5)
FS-33: Rf1-L36-Hy1 (n = 10)
FS-34: Rf1-L36-Hy1 (n = 15)
FS-35: Rf1-L36-Hy1 (n = 20)
FS-36: Rf7-L36-Hy1 (n = 8)
FS-37: Rf7-L36-Hy1 (n = 13)
FS-38: Rf7-L36-Hy1 (n = 18)
FS-39: Rf7-L36-Hy1 (n = 25)
FS-40: Rf1-L0-Hy1 (n = 6)

FS-41: Rf1-L0-Hy1 (n = 11)
FS-42: Rf1-L0-Hy1 (n = 16)
FS-43: Rf1-L0-Hy1 (n = 21)
FS-44: Rf1-L31 ( R = C 3 H 7) -Hy2 (n = 7, R1 = C 2 H 5)
FS-45: Rf1-L31 ( R = C 3 H 7) -Hy2 (n = 13, R1 = C 2 H 5)
FS-46: Rf1-L31 ( R = C 3 H 7) -Hy2 (n = 20, R1 = C 2 H 5)
FS-47: Rf1-L31 ( R = C 3 H 7) -Hy2 (n = 28, R1 = C 2 H 5)
FS-48: Rf8-L32 ( AL = CH 2) -Hy1 (n = 5)
FS-49: Rf8-L32 ( AL = CH 2) -Hy1 (n = 10)
FS-50: Rf8-L32 ( AL = CH 2) -Hy1 (n = 15)
FS-51: Rf8-L32 ( AL = CH 2) -Hy1 (n = 20)
FS-52: Rf1-L37 ( R = C 3 H 7, AL = CH 2 CH 2) -Hy3 (n = 5)
FS-53: Rf1-L37 ( R = C 3 H 7, AL = CH 2 CH 2) -Hy3 (n = 7)
FS-54: Rf1-L37 ( R = C 3 H 7, AL = CH 2 CH 2) -Hy3 (n = 9)
FS-55: Rf1-L37 ( R = C 3 H 7, AL = CH 2 CH 2) -Hy3 (n = 12)
FS-56: Rf9-L0-Hy4 (M = H)
FS-57: Rf3-L0-Hy4 (M = H)
FS-58: Rf1-L38 ( R = C 3 H 7, AL = CH 2) -Hy4 (M = K)
FS-59: Rf4-L39 ( R = C 3 H 7, AL = CH 2) -Hy4 (M = Na)

FS-60: Rf1-L0-Hy5 (M = K)
FS-61: Rf10-L40 ( AL1 = CH 2, AL 2 = CH 2 CH 2) -Hy5 (M = Na)
FS-62: Rf11-L40 ( AL1 = CH 2, AL 2 = CH 2 CH 2) -Hy5 (M = Na)
FS-63: Rf5-L40 ( AL1 = CH 2, AL 2 = CH 2 CH 2) -Hy5 (M = Na)
FS-64: Rf1-L38 ( R = C 3 H 7, AL = CH 2 CH 2 CH 2) -Hy5 (M = Na)
FS-65: Rf1-L31 ( R = C 3 H 7) -Hy6 (n = 5, M = Na) FS-66: Rf1-L31 (R = C 3 H 7) -Hy6 (n = 10, M = Na)
FS-67: Rf1-L31 ( R = C 3 H 7) -Hy6 (n = 15, M = Na)
FS-68: Rf1-L31 ( R = C 3 H 7) -Hy6 (n = 20, M = Na)
FS-69: Rf1-L38 ( R = C 2 H 5, AL = CH 2 CH 2) -Hy7
FS-70: Rf1-L38 ( R = H, AL = CH 2 CH 2 CH 2) -Hy8 (X = I)
FS-71: Rf11-L41 (below _{Hc, AL = CH 2 CH 2} CH 2) -Hy6 (M is dissociated)

FS-72: Rf1-L42 ( R = C 3 H 7, AL1 = CH 2 CH 2, AL2 = CH 2 CH 2 CH 2) -Hy6 (M = Na)
FS-73: Rf12-L0-Hy5 (M = Na)
FS-74: Rf13-L43 (AR = o-phenylene) -Hy6 (M = K)
FS-75: Rf13-L43 (AR = m-phenylene) -Hy6 (M = K)
FS-76: Rf13-L43 (AR = p-phenylene) -Hy6 (M = K)
FS-77: Rf6-L44 ( R = C 2 H 5, AL = CH 2 CH 2) -Hy5 (M = H)
FS-78: Rf6-L45 ( AR = p- _{phenylene, R = C 2 H 5)} -Hy1 (n = 9)
FS-79: Rf6-L45 ( AR = p- _{phenylene, R = C 2 H 5)} -Hy1 (n = 14)
FS-80: Rf6-L45 ( AR = p- _{phenylene, R = C 2 H 5)} -Hy1 (n = 19)
FS-81: Rf6-L45 ( AR = p- _{phenylene, R = C 2 H 5)} -Hy1 (n = 28)
FS-82: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 5)
FS-83: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 10)
FS-84: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 15)
FS-85: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 20)

  A fluorine-containing surfactant having two or more hydrophobic groups or hydrophilic groups containing fluorine atoms may be used. Examples of the fluorine-containing surfactant having two or more hydrophobic groups or hydrophilic groups are shown below.

  FS-86: n1 + n2 = 12, FS-87: n1 + n2 = 18, FS-88: n1 + n2 = 24

  FS-89: n1 + n2 = 20, FS-90: n1 + n2 = 30, FS-91: n1 + n2 = 40

  FS-92: n = 5, FS-93: n = 10, FS-94: n = 15, FS-95: n = 20

  Two or more fluorine-containing surfactants may be used in combination. As for the surfactant, various documents (eg, Hiroshi Horiguchi “New Surfactant” Sankyo Publishing (1975), MJ Schick, Nonionic Surfactants, Marcell Dekker Inc., New York, (1967), Japanese Patent Laid-Open No. 7-13293. Gazette). The fluorine-containing surfactant is used in an amount of 2 to 30% by weight based on the amount of discotic liquid crystalline molecules. The amount used is preferably 3 to 25% by weight, more preferably 5 to 10% by weight, based on the amount of discotic liquid crystalline molecules.

  Two or more kinds of compounds having 1,3,5-triazine ring (including melamine compounds and melamine polymers) may be used in combination. The compound having a 1,3,5-triazine ring is used in an amount of 0.01 to 20% by weight of the amount of the liquid crystal compound. The amount used is preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, based on the amount of the liquid crystal compound.

  The optically anisotropic layer is formed by coating on the stretched polymer film or the alignment film according to the present invention. As a solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of organic solvents include amides (eg, dimethylformamide), sulfoxides (eg, dimethylsulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, chloroform, dichloromethane) ), Esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination. The coating liquid can be applied by a known method (eg, curtain coating method, extrusion coating method, roll coating method, spin coating method, dip coating method, print coating method, spray coating method, slide coating method). It is preferable to form the optically anisotropic layer by continuous coating. Curtain coating, roll coating and slide coating are suitable for continuous application.

  The thickness of the optically anisotropic layer is preferably 0.5 to 100 μm, and more preferably 0.5 to 30 μm.

(Alignment film)
The alignment film has a function of determining the alignment direction of the liquid crystalline compound contained in the optically anisotropic layer.
The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably formed by polymer rubbing treatment. The rubbing treatment is preferably performed in a direction substantially perpendicular to the slow axis of the stretched polymer film. Thereby, it is possible to make the slow axis of a stretched polymer film and the slow axis of an optically anisotropic layer orthogonal.

The polymer is preferably polyvinyl alcohol. Particularly preferred is a modified polyvinyl alcohol to which a hydrophobic group is bonded. Since the hydrophobic group has an affinity with the liquid crystalline compound of the optically anisotropic layer, the liquid crystalline compound can be uniformly aligned by introducing the hydrophobic group into polyvinyl alcohol. The hydrophobic group is bonded to the main chain terminal or side chain of polyvinyl alcohol.
The hydrophobic group is preferably an aliphatic group having 6 or more carbon atoms (preferably an alkyl group or an alkenyl group) or an aromatic group.
When a hydrophobic group is bonded to the main chain terminal of polyvinyl alcohol, it is preferable to introduce a linking group between the hydrophobic group and the main chain terminal. Examples of the linking group include —S—, —C (CN) R ¹ —, —NR ² —, —CS—, and combinations thereof. R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably an alkyl group having 1 to 6 carbon atoms).

When a hydrophobic group is introduced into the side chain of polyvinyl alcohol, a part of the acetyl group (—CO—CH ₃ ) of the vinyl acetate unit of polyvinyl alcohol is substituted with an acyl group (—CO—R) having 7 or more carbon atoms. ³ ). R ³ is an aliphatic group or an aromatic group having 6 or more carbon atoms.
Commercially modified polyvinyl alcohol (eg, MP103, MP203, R1130, manufactured by Kuraray Co., Ltd.) may be used.
The saponification degree of the (modified) polyvinyl alcohol used for the alignment film is preferably 80% or more. The degree of polymerization of (modified) polyvinyl alcohol is preferably 200 or more.
The rubbing treatment is performed by rubbing the surface of the alignment film several times in a certain direction with paper or cloth. It is preferable to use a cloth in which fibers having uniform length and thickness are uniformly planted.
Note that the alignment state of the liquid crystalline compound can be maintained even if the alignment film is removed after aligning the liquid crystalline compound of the optically anisotropic layer with the alignment film. That is, the alignment film is indispensable in the production of the optical compensation sheet in order to align the liquid crystalline compound, but is not essential in the produced optical compensation sheet.
In the case where the alignment film is provided between the stretched polymer film and the optical anisotropy, an adhesive layer (undercoat layer) may be further provided between the stretched polymer film and the alignment film.

  In the optically anisotropic layer of the present invention, the average tilt angle of the liquid crystalline compound can be adjusted by an alignment layer containing a modified polyvinyl alcohol described in JP-A No. 2000-155216.

(Retardation of optically anisotropic layer)
In the present invention, Re (546) of the optically anisotropic layer is preferably from 10 nm to 300 nm, and more preferably from 30 nm to 250 nm. Rth (546) is preferably 10 nm or more and 300 nm or less, and preferably 30 nm or more and 250 nm or less.

Furthermore, the optically anisotropic layer in the present invention preferably satisfies the following formulas (K) to (N).
1.0 <Re (480) / Re (546) <2.0 (K)
0.5 <Re (628) / Re (546) <1.0 (L)
1.0 <Rth (480) / Rth (546) <2.0 (M)
0.5 <Rth (628) / Rth (546) <1.0 (N)
Formula (K) is more preferably 1.02 <Re (480) / Re (546) <1.50, and more preferably 1.05 <Re (480) / Re (546) <1.30. .
The formula (L) is more preferably 0.75 <Re (628) / Re (546) <0.98.
The formula (M) is more preferably 1.02 <Rth (480) / Rth (546) <1.50, and more preferably 1.05 <Rth (628) / Rth (546) <1.30. .
By adjusting the retardation within the above range, an optical compensation sheet having a high contrast and a small color change can be obtained.

<Retardation of optical compensation sheet>
The optical compensation sheet of the present invention has an optically anisotropic layer on a stretched polymer film, and is arranged so that the slow axis of the stretched polymer film and the slow axis of the optically anisotropic layer are perpendicular to each other.
By arranging in this way, there is an effect that the wavelength dispersion of Re of the optical compensation sheet becomes smaller as the wavelength is shorter.

The retardation of the optical compensation sheet of the present invention preferably satisfies the relationship of the following formula.
30 nm <Re (546) <150 nm (A)
100 nm <Rth (546) <400 nm (B)
0.5 <Re (480) / Re (546) <1 (C)
1.0 <Re (628) / Re (546) <2.0 (D)
1.0 <Rth (480) / Rth (546) <1.5 (E)
0.7 <Rth (628) / Rth (546) <1.0 (F)
In Formula (A), 35 nm <Re (546) <120 nm is preferable, and 40 nm <Re (546) <100 nm is more preferable.
In the formula (B), 110 nm <Rth (546) <350 nm is preferable, and 120 nm <Rth (546) <300 nm is more preferable.
In the formula (C), 0.6 <Re (480) / Re (546) <0.95 is preferable, and 0.7 <Re (480) / Re (546) <0.9 is more preferable.
In the formula (D), 1.0 <Re (628) / Re (546) <1.50 is preferable, and 1.02 <Re (628) / Re (546) <1.30 is more preferable.
In the formula (E), 1.00 <Rth (480) / Rth (546) <1.30 is preferable, and 1.01 <Rth (480) / Rth (546) <1.20 is more preferable.
In the formula (F), 0.8 <Rth (628) / Rth (546) <1.0 is preferable, and 0.85 <Rth (628) / Rth (546) <0.99 is more preferable.
By adjusting the retardation of the optical compensation sheet within the above range, it is possible to reduce the color change due to the viewing angle of the liquid crystal display device.

<Preparation of polarizing plate>
Next, a polarizing plate including the optical compensation sheet of the present invention will be described with reference to the drawings.
FIG. 1A schematically shows a cross-sectional view of a general polarizing plate, and is configured by bonding protective films 1 and 3 to both ends of a polarizer 2. On the other hand, FIG. 1 (B) is a schematic cross-sectional view showing an example of the case where the optical compensation sheet of the present invention is used as a protective film for a polarizing plate. The optical compensation sheet (the optically anisotropic layer 3 and the stretched polymer film 4) of the present invention is bonded to the surface so that the stretched polymer film 4 is on the polarizer side.

(Protective film)
The polarizing plate of the present invention preferably has two protective films, one on each side of the polarizer, and at least one is the optical compensation sheet of the present invention.
The protective film (transparent support) used on the other surface of the polarizer in the present invention is a polymer film produced from norbornene resin, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyarylate, polysulfone, cellulose acylate, etc. And is most preferably a cellulose acylate film.

(Polarizer)
Next, the polarizer used for the polarizing plate of the present invention will be described.
The polarizer of the present invention is preferably composed of polyvinyl alcohol (PVA) and a dichroic molecule. However, as described in JP-A-11-248937, PVA and polyvinyl chloride are dehydrated and dechlorinated. Polyvinylene-based polarizers in which a polyene structure is generated and oriented can also be used.

PVA is a polymer material obtained by saponifying polyvinyl acetate, but may contain components copolymerizable with vinyl acetate such as unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, and vinyl ethers. . In addition, modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.
The saponification degree of PVA is not particularly limited, but is preferably 80 to 100 mol%, particularly preferably 90 to 100 mol% from the viewpoint of solubility and the like. The degree of polymerization of PVA is not particularly limited, but is preferably 1000 to 10,000, and particularly preferably 1500 to 5000.
The syndiotacticity of PVA is preferably 55% or more for improving durability as described in Japanese Patent No. 2978219, but 45 to 52.5% described in Japanese Patent No. 3317494 is also preferably used. it can.

After PVA is formed into a film, it is preferable to introduce a dichroic molecule to constitute a polarizer. As a method for producing a PVA film, a method of forming a film by casting a stock solution in which a PVA resin is dissolved in water or an organic solvent is generally preferably used. The concentration of the polyvinyl alcohol-based resin in the stock solution is usually 5 to 20% by mass, and a PVA film having a thickness of 10 to 200 μm can be produced by forming this stock solution by casting. The PVA film can be produced with reference to Japanese Patent No. 3342516, Japanese Patent Application Laid-Open No. 09-328593, Japanese Patent Application Laid-Open No. 2001-302817, and Japanese Patent Application Laid-Open No. 2002-144401.
The degree of crystallinity of the PVA film is not particularly limited. However, in order to reduce the average crystallinity (Xc) of 50 to 75% by mass described in Japanese Patent No. 3251073 and the in-plane hue variation, Japanese Patent Application Laid-Open No. 2002-2005 A PVA film having a crystallinity of 38% or less described in No. 236214 can be used.

The birefringence (Δn) of the PVA film is preferably small, and a PVA film having a birefringence of 1.0 × 10 ⁻³ or less described in Japanese Patent No. 3342516 can be preferably used. However, as described in JP-A No. 2002-228835, in order to obtain a high degree of polarization while avoiding cutting during stretching of the PVA film, the birefringence of the PVA film may be set to 0.002 or more and 0.01 or less. Alternatively, as described in JP-A-2002-060505, the value of (nx + ny) / 2-nz may be 0.0003 or more and 0.01 or less. The retardation (in-plane) of the PVA film is preferably from 0 nm to 100 nm, and more preferably from 0 nm to 50 nm. The Rth (film thickness direction) of the PVA film is preferably 0 nm or more and 500 nm or less, and more preferably 0 nm or more and 300 nm or less.

In addition, the polarizing plate of the present invention includes a PVA film having a 1,2-glycol bond amount of 1.5 mol% or less described in Japanese Patent No. 3021494, 5 μm or more described in JP-A No. 2001-316492. PVA film having 500 or less optical foreign matter per 100 cm ² , PVA film having a hot water cutting temperature spot of 1.5 ° C. or less in the TD direction of the film described in JP-A-2002-030163, and glycerin A PVA film formed from a solution obtained by mixing 1 to 100 parts by mass of a trivalent to hexavalent polyhydric alcohol such as the above or a mixture of 15% by mass or more of a plasticizer described in JP-A-06-289225. It can be preferably used.

  Although the film thickness before extending | stretching of a PVA film is not specifically limited, 1 micrometer-1 mm are preferable and 20-200 micrometers is especially preferable from a viewpoint of stability of film holding | maintenance and the uniformity of extending | stretching. As described in JP-A-2002-236212, a thin PVA film in which the stress generated when stretching 4 to 6 times in water is 10 N or less may be used.

Dichroic molecule I ₃ ^- or I ₅ ^- can be preferably used an iodine ion or a dichroic dye higher such. In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions are described in “Applications of Polarizing Plates” by Nagata Ryo, CMC Publishing and Industrial Materials, Vol. 28, No. 7, p. 39-p. As described in 45, PVA can be produced by immersing PVA in a solution obtained by dissolving iodine in an aqueous potassium iodide solution and / or an aqueous boric acid solution and adsorbing and orienting the PVA.

  When a dichroic dye is used as the dichroic molecule, an azo dye is preferable, and a bisazo dye and a trisazo dye are particularly preferable. The dichroic dye is preferably a water-soluble dye. For this reason, a hydrophilic substituent such as a sulfonic acid group, an amino group or a hydroxyl group is introduced into the dichroic molecule, so that a free acid, an alkali metal salt, an ammonium salt or an amine is introduced. It is preferably used as a salt.

Specific examples of such dichroic dyes include, for example, CIDirect Red 37, Congo Red (CI Direct Red 28), CIDirect Violet 12, CIDirect Blue 90, CIDirect Blue 22, CIDirect Blue 1, CIDirect Blue 151, CIDirect Green 1st benzidine series, CIDirect Yellow 44, CIDirect Red 23, CIDirect Red 79 etc. diphenylurea series, CIDirect Yellow 12 etc. stilbene series, CIDirect Red,
Examples thereof include dinaphthylamine series such as 31 and J acid series such as CIDirect Red 81, CIDirect Violet 9 and CIDirect Blue 78.
Besides this, CIDirect Yellow 8, CIDirect Yellow 28, CIDirect Yellow 86, CIDirect Yellow 87, CIDirect Yellow 142, CIDirect Orange 26, CIDirect Orange 39, CIDirect Orange 72, CIDirect Orange 106, CIDirect Orange 107, CIDirect Red 2, CIDirect Red Red 39, CIDirect Red 83, CIDirect Red 89, CIDirect Red 240, CIDirect Red 242, CIDirect Red 247, CIDirect Violet 48, CIDirect Violet 51, CIDirect Violet 98, CIDirect Blue 15, CIDirect Blue 67, CIDirect Blue 71, CIDirect,
Blue 98, CIDirect Blue 168, CIDirect Blue 202, CIDirect Blue 236, CIDirect Blue 249, CIDirect Blue 270, CIDirect Green 59, CIDirect Green 85, CIDirect Brown 44, CIDirect Brown 106, CIDirect Brown 195, CIDirect Brown 210, CIDirect Brown 223 CIDirect Brown 224, CIDirect Black 1, CIDirect Black 17, CIDirect Black 19, CIDirect Black 54, and the like are further disclosed in Japanese Patent Laid-Open Nos. 62-70802, 1-161202, 1-172906, and 1-. The dichroic dyes described in JP-A Nos. 172907, 1-183602, 1-248105, 1-265205, and 7-261024 can also be preferably used. In order to produce dichroic molecules having various hues, two or more of these dichroic dyes may be blended. When a dichroic dye is used, the adsorption thickness may be 4 μm or more as described in JP-A No. 2002-082222.

If the content of the dichroic molecule in the film is too small, the degree of polarization is low, and if it is too large, the single-plate transmittance is lowered. Therefore, the polyvinyl alcohol polymer constituting the film matrix is usually used. On the other hand, it is adjusted in the range of 0.01% by mass to 5% by mass.
A preferable film thickness of the polarizer is preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm. The ratio between the thickness of the polarizer and the thickness of the protective film described later is 0.01 ≦ A (polarizer film thickness) / B (protective film thickness) ≦ 0.16 described in JP-A No. 2002-174727. A range is also preferable.
The crossing angle between the slow axis of the protective film and the absorption axis of the polarizer may be any value, but is preferably parallel or an azimuth angle of 45 ± 20 °.

<Polarizing plate manufacturing process>
Next, the manufacturing process of the polarizing plate of this invention is demonstrated.
The production process of the polarizing plate in the present invention is preferably composed of a swelling process, a dyeing process, a hardening process, a stretching process, a drying process, a protective film bonding process, and a post-bonding drying process. The order of the dyeing step, the hardening step, and the stretching step may be arbitrarily changed, or several steps may be combined and performed simultaneously. Further, as described in Japanese Patent No. 3331615, washing with water after the hardening step can be preferably performed.

  In the present invention, it is particularly preferable to sequentially perform the swelling process, the dyeing process, the hardening process, the stretching process, the drying process, the protective film bonding process, and the drying process after bonding in the order described. An on-line surface inspection step may be provided during or after the above-described steps.

The swelling step is preferably carried out only with water, but as described in JP-A-10-153709, in order to stabilize optical performance and avoid wrinkling of the polarizing plate substrate in the production line, polarized light is used. It is also possible to manage the degree of swelling of the polarizing plate substrate by swelling the plate substrate with an aqueous boric acid solution.
Moreover, although the temperature and time of a swelling process can be defined arbitrarily, 10 to 60 degreeC and 5 to 2000 second are preferable.
For the dyeing step, the method described in JP-A-2002-86554 can be used. Further, as a dyeing method, not only immersion but any means such as application or spraying of iodine or a dye solution can be used. Further, as described in JP-A No. 2002-290025, iodine concentration, dye bath temperature, draw ratio in the bath, and a method of dyeing while stirring the bath liquid in the bath may be used.

When high-order iodine ions are used as the dichroic molecule, in order to obtain a high-contrast polarizing plate, it is preferable to use a solution in which iodine is dissolved in an aqueous potassium iodide solution in order to obtain a high-contrast polarizing plate. In this case, iodine in the iodine-potassium iodide aqueous solution is preferably 0.05 to 20 g / l, potassium iodide is 3 to 200 g / l, and the mass ratio of iodine and potassium iodide is preferably 1 to 2000. The dyeing time is preferably 10 to 1200 seconds, and the liquid temperature is preferably 10 to 60 ° C. More preferably, iodine is 0.5 to 2 g / l, potassium iodide is 30 to 120 g / l, the mass ratio of iodine and potassium iodide is 30 to 120, dyeing time is 30 to 600 seconds, and liquid temperature is 20-50 degreeC is good.
Further, as described in Japanese Patent No. 3145747, boron compounds such as boric acid and borax may be added to the dyeing solution.

  In the hardening step, it is preferable to immerse in the crosslinking agent solution or apply the solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the hardening process can be performed in several steps.

  As the cross-linking agent, those described in US Reissue Patent No. 232897 can be used, and as described in Japanese Patent No. 3357109, a polyhydric aldehyde may be used as a cross-linking agent in order to improve dimensional stability. However, boric acids are most preferably used. When boric acid is used as a crosslinking agent used in the hardening step, metal ions may be added to the boric acid-potassium iodide aqueous solution. Zinc chloride is preferred as the metal ion, but as described in JP 2000-35512 A, zinc halides such as zinc iodide, zinc sulfates, zinc acetates and the like are used instead of zinc chloride. You can also.

  In the present invention, it is preferable to prepare a boric acid-potassium iodide aqueous solution to which zinc chloride has been added, and perform dura- tion by immersing the PVA film. Boric acid is preferably 1 to 100 g / l, potassium iodide is 1 to 120 g / l, zinc chloride is preferably 0.01 to 10 g / l, hardening time is preferably 10 to 1200 seconds, and liquid temperature is preferably 10 to 60 ° C. . More preferably, boric acid is 10 to 80 g / l, potassium iodide is 5 to 100 g / l, zinc chloride is 0.02 to 8 g / l, hardening time is 30 to 600 seconds, and liquid temperature is 20 to 50 ° C is preferable.

  For the stretching step, a longitudinal uniaxial stretching method as described in US Pat. No. 2,454,515, or a tenter method as described in JP-A-2002-86554 can be preferably used. A preferable draw ratio is 2 times or more and 12 times or less, and more preferably 3 times or more and 10 times or less. Moreover, the relationship between the draw ratio, the thickness of the original fabric and the thickness of the polarizer is described in JP-A No. 2002-040256 (polarizer film thickness / raw film thickness after bonding of protective film) × (total draw ratio). > 0.17 or the relationship between the width of the polarizer when leaving the final bath and the width of the polarizer when bonding the protective film is 0.80 ≦ (protective film pasting) described in JP-A-2002-040247 It is also possible to preferably satisfy the following condition: polarizer width at the time / width of the polarizer when leaving the final bath) ≦ 0.95.

  As the drying step, a method known in JP-A-2002-86554 can be used, but a preferable temperature range is 30 ° C. to 100 ° C., and a preferable drying time is 30 seconds to 60 minutes. Further, as described in Japanese Patent No. 3148513, heat treatment is performed so that the fading temperature in water is 50 ° C. or higher, or as described in Japanese Patent Laid-Open Nos. 07-325215 and 07-325218. Aging in a temperature and humidity controlled atmosphere can also be preferably performed.

  A protective film bonding process is a process of bonding the both surfaces of the above-mentioned polarizer which went out of the drying process with two protective films. A method of bonding with a pair of rolls is preferably used so that the adhesive liquid is supplied immediately before bonding and the polarizer and the protective film are overlapped. In addition, as described in JP-A-2001-296426 and JP-A-2002-86554, the moisture content of the polarizer at the time of bonding is adjusted in order to suppress the groove-like unevenness of the record due to the stretching of the polarizer. It is preferable to do. In the present invention, a moisture content of 0.1% to 30% is preferably used.

  The adhesive between the polarizer and the protective film is not particularly limited, and examples thereof include PVA resin (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. PVA resin is preferable. The thickness of the adhesive layer is preferably 0.01 to 5 μm, and particularly preferably 0.05 to 3 μm after drying.

Moreover, in order to improve the adhesive force of a polarizer and a protective film, it is preferable to perform adhesion after surface-treating the protective film to make it hydrophilic. The surface treatment method is not particularly limited, and a known method such as a saponification method using an alkaline solution or a corona treatment method can be used. Further, an easy-adhesion layer such as a gelatin undercoat layer may be provided after the surface treatment. As described in JP-A-2002-267839, the contact angle of the protective film surface with water is preferably 50 ° or less.
The drying conditions after bonding are in accordance with the method described in JP-A-2002-86554, but the preferred temperature range is 30 ° C. to 100 ° C., and the preferred drying time is 30 seconds to 60 minutes. It is also preferable to perform aging in an atmosphere with temperature and humidity control as described in JP-A-07-325220.

Element content in the polarizer, iodine 0.1 to 3.0 g / m ^2, boron 0.1 to 5.0 g / m ^2, potassium 0.1~2.00g / m ^2, zinc 0-2. It is preferably 00 g / m ² . Further, the potassium content may be 0.2% by mass or less as described in JP-A No. 2001-166143, and the zinc content in the polarizer is described in JP-A No. 2000-035512. It is good also as 0.04 mass%-0.5 mass%.

  As described in Japanese Patent No. 3323255, in order to increase the dimensional stability of the polarizing plate, an organic titanium compound and / or an organic zirconium compound is added and used in any of the dyeing process, stretching process and hardening process And at least 1 type of compound chosen from the organic titanium compound and the organic zirconium compound can also be contained. A dichroic dye may be added to adjust the hue of the polarizing plate.

<Characteristics of polarizing plate>
(1) Transmittance and degree of polarization The preferred single plate transmittance of the polarizing plate of the present invention is 42.5% or more and 49.5% or less, more preferably 42.8% or more and 49.0% or less. A preferable range of the degree of polarization defined by Formula 4 is 99.900% or more and 99.999% or less, and more preferably 99.940% or more and 99.995% or less. A preferable range of the parallel transmittance is 36% or more and 42% or less, and a preferable range of the orthogonal transmittance is 0.001% or more and 0.05% or less. The preferable range of the dichroic ratio defined by the following formula 5 is 48 or more and 1215 or less, and more preferably 53 or more and 525 or less.

  The above-described transmittance is defined by the following formula based on JISZ8701.

  Here, K, S (λ), y (λ), and τ (λ) are as follows.

S (λ): spectral distribution of standard light used for color display y (λ): color matching function in XYZ system
τ (λ): Spectral transmittance

The iodine concentration and the single plate transmittance may be within the ranges described in JP-A No. 2002-258051.
The parallel transmittance may be small in wavelength dependency as described in Japanese Patent Application Laid-Open Nos. 2001-083328 and 2002-022950. The optical characteristics when the polarizing plates are arranged in crossed Nicols may be in the range described in Japanese Patent Application Laid-Open No. 2001-091736, and the relationship between parallel transmittance and orthogonal transmittance is disclosed in Japanese Patent Application Laid-Open No. 2002-174728. It may be within the range described.

  As described in Japanese Patent Application Laid-Open No. 2002-221618, the standard deviation of the parallel transmittance every 10 nm when the light wavelength is between 420 and 700 nm is 3 or less, and the light wavelength is between 420 and 700 nm. The minimum value of (parallel transmittance / orthogonal transmittance) every 10 nm may be 300 or more.

  The parallel transmittance and the orthogonal transmittance at a wavelength of 440 nm of the polarizing plate, the parallel transmittance, the parallel transmittance and the orthogonal transmittance at a wavelength of 550 nm, and the parallel transmittance and the orthogonal transmittance at a wavelength of 610 nm are disclosed in JP-A No. 2002-258042 and JP-A No. 2002-80442. The range described in 2002-258043 can also be preferably performed.

(2) Hue The hue of the polarizing plate of the present invention is preferably evaluated using the lightness index L ^* and the chromaticness index a ^* and b ^* in the L ^* a ^* b ^* color system recommended as a CIE uniform perceptual space. Is done.
L ^* , a ^* , and b ^* are defined by Equation 6 using X, Y, and Z described above.

Here, X ₀ , Y ₀ , and Z ₀ represent tristimulus values of the illumination light source. In the case of the standard light C, X ₀ = 98.072, Y ₀ = 100, Z ₀ = 118.225, and the standard light D _In the case of ₆₅ , X ₀ = 95.045, Y ₀ = 100, and Z ₀ = 108.892.

A preferable range of a ^* of the single polarizing plate is −2.5 or more and 0.2 or less, and more preferably −2.0 or more and 0 or less. A preferable range of b ^* of the single polarizing plate is 1.5 or more and 5 or less, and more preferably 2 or more and 4.5 or less. The preferable range of a ^* of the parallel transmitted light of the two polarizing plates is −4.0 to 0, and more preferably −3.5 to −0.5. A preferable range of b ^* of parallel transmitted light of the two polarizing plates is 2.0 or more and 8 or less, and more preferably 2.5 or more and 7 or less. The preferred range of a ^* of the orthogonally transmitted light of the two polarizing plates is from −0.5 to 1.0, and more preferably from 0 to 2. The preferable range of b ^* of the orthogonally transmitted light of the two polarizing plates is −2.0 or more and 2 or less, and more preferably −1.5 or more and 0.5 or less.

The hue may be evaluated by the chromaticity coordinates (x, y) calculated from the aforementioned X, Y, and Z. For example, the chromaticity (x _p , y _p ) of the parallel transmitted light of the two polarizing plates And the chromaticity (x _c , y _c ) of the orthogonal transmitted light are within the ranges described in JP-A Nos. 2002-214436, 2001-166136 and 2002-169024, and the relationship between hue and absorbance is It can also be preferably performed within the range described in JP-A-2001-311827.

(3) Viewing angle characteristics When a polarizing plate is placed in crossed Nicol and light with a wavelength of 550 nm is incident, when vertical light is incident, from a azimuth of 45 degrees with respect to the polarization axis, 40 degrees with respect to the normal line It is also preferable that the transmittance ratio and the xy chromaticity difference when the light is incident at an angle of within the range described in Japanese Patent Application Laid-Open Nos. 2001-166135 and 2001-166137. Further, as described in JP-A-10-068817, the light transmittance (T ₀ ) in the vertical direction of the polarizing plate laminate having the crossed Nicols arrangement and the light transmission in the direction inclined by 60 ° from the normal line of the laminate. The ratio (T ₆₀ / T ₀ ) to the rate (T ₆₀ ) is 10000 or less, or as described in JP-A No. 2002-139625, the polarizing plate is at an arbitrary angle from the normal to an elevation angle of 80 degrees. When natural light is incident, the transmittance difference of transmitted light within a wavelength range of 20 nm within the wavelength range of 520 to 640 nm of the transmission spectrum is set to 6% or less, or a film described in JP-A-08-248201 It is also preferable that the brightness difference of the transmitted light at an arbitrary place 1 cm above is within 30%.

(4) Durability
(4-1) Damp heat durability It is preferable that the light transmittance and the change rate of the polarization degree before and after leaving in an atmosphere of 60 ° C. and 95% RH for 500 hours are 3% or less based on absolute values. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less based on the absolute value. Further, as described in JP-A-07-0777608, it is also preferred that the degree of polarization after standing at 80 ° C. and 90% RH for 500 hours is 95% or more and the single transmittance is 38% or more.

(4-2) Dry durability It is preferable that the light transmittance and the rate of change of the degree of polarization before and after standing in a dry atmosphere at 80 ° C. for 500 hours are also 3% or less based on absolute values. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value.

(4-3) Other durability Further, as described in JP-A-06-167611, the shrinkage after standing at 80 ° C. for 2 hours is reduced to 0.5% or less, or the both sides of the glass plate are crossed. The x and y values after leaving the Nicol-arranged polarizing plate laminate in an atmosphere of 69 ° C. for 750 hours are within the ranges described in JP-A-10-068818, or an atmosphere of 80 ° C. and 90% RH. the change in spectral intensity ratio of the 105 cm ^-1 and 157cm ^-1 after 200 hours standing processing by Raman spectroscopy at medium, it is also preferable to fall within the range as described in JP-a-08-094834 and JP-a-09-197127 It can be carried out.

(5) Orientation degree The higher the degree of orientation of PVA, the better the polarization performance, but the preferred order parameter value is 0.2 to 1.0 as calculated by means such as polarized Raman scattering and polarized light FT-IR. It is. Further, as described in JP-A-59-133509, the difference between the orientation coefficient of the polymer segment in the entire amorphous region of the polarizer and the orientation coefficient of the occupied molecule (0.75 or more) is at least 0.7. 15, the orientation coefficient of the amorphous region of the polarizer is 0.65 to 0.85, as described in JP-A No. 04-204907, and the higher order iodine ions of I ₃ ^- and I _5- It is also preferable to set the degree of orientation to 0.8 to 1.0 as an order parameter value.

(6) Other characteristics As described in JP-A-2002-006133, the contraction force in the absorption axis direction per unit width when heated at 80 ° C. for 30 minutes is set to 4.0 N / cm or less. As described in 2002-236213, when the polarizing plate was placed under heating conditions of 70 ° C. for 120 hours, both the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarization axis direction of the polarizing plate were It is also preferable to make it within ± 0.6%, or to set the moisture content of the polarizing plate to 3% by mass or less as described in JP-A-2002-090546. Further, as described in JP-A No. 2000-249832, the surface roughness in the direction perpendicular to the stretching axis is set to 0.04 μm or less based on the center line average roughness, or described in JP-A No. 10-268294. The refractive index n ₀ in the transmission axis direction is preferably made larger than 1.6, or the relationship between the thickness of the polarizing plate and the thickness of the protective film is preferably within the range described in JP-A-10-111411. be able to.

<Functionalization of polarizing plate>
The polarizing plate of the present invention is combined with an optical film having functional layers such as an antireflection film, a brightness enhancement film, a hard coat layer, a forward scattering layer, and an antiglare (antiglare) layer for improving the visibility of the display. Also good.

(Antireflection film)
The polarizing plate of the present invention can be used in combination with an antireflection film. For the anti-reflection film, either a film having a reflectance of about 1.5% only by applying a single layer of a low refractive index material such as a fluorine-based polymer, or a film having a reflectance of 1% or less using multilayer interference of a thin film is used. it can. In the present invention, a structure in which a low refractive index layer and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer and a middle refractive index layer) is laminated on a transparent support is preferably used. The In addition, Nitto Technical Report, vol. 38, no. 1, may, 2000, pages 26 to 28 and JP-A No. 2002-301783 can also be preferably used.
The refractive index of each layer satisfies the following relationship.

The refractive index of the high refractive index layer> The refractive index of the medium refractive index layer> The refractive index of the transparent support> The refractive index of the low refractive index layer. The transparent support used for the antireflection film is used for the protective film for the polarizer described above. A transparent polymer film can be preferably used.

  The refractive index of the low refractive index layer is 1.20 to 1.55, preferably 1.30 to 1.50. The low refractive index layer is preferably used as an outermost layer having scratch resistance and antifouling properties. In order to improve the scratch resistance, it is also preferable to impart slipperiness to the surface using a material containing a silicone group or fluorine.

Examples of the fluorine-containing compound include paragraphs [0018] to [0026] of JP-A-9-222503, paragraphs [0019] to [0030] of JP-A-11-38202, and JP-A-2001-40284. The compounds described in paragraph Nos. [0027] to [0028] and JP-A No. 2000-284102 can be preferably used.
The silicone-containing compound is preferably a compound having a polysiloxane structure, but reactive silicone (eg, Silaplane (manufactured by Chisso Corporation), silanol group-containing polysiloxane at both ends (Japanese Patent Laid-Open No. 11-258403), etc. An organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent may be cured by a condensation reaction in the presence of a catalyst (Japanese Patent Laid-Open No. 58-142958). Gazettes, 58-147483, 58-147484, JP-A-9-157582, 11-106704, JP-A-2000-117902, 2001-48590, 2002-2002. 53804).
The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as fillers (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as additives other than the above. And a low refractive index inorganic compound, organic fine particles described in paragraphs [0020] to [0038] of JP-A-11-3820), silane coupling agents, slip agents, surfactants, and the like are also preferably included. be able to.

The low refractive index layer may be formed by a vapor phase method (vacuum vapor deposition method, sputtering method, ion plating method, plasma CVD method, etc.), but is preferably formed by a coating method because it can be manufactured at low cost. . As the coating method, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, and micro gravure can be preferably used.
The film thickness of the low refractive index layer is preferably 30 to 200 nm, more preferably 50 to 150 nm, and most preferably 60 to 120 nm.

The medium refractive index layer and the high refractive index layer preferably have a constitution in which ultrafine particles of high refractive index having an average particle size of 100 nm or less are dispersed in a matrix material. Inorganic compound fine particles having a high refractive index include inorganic compounds having a refractive index of 1.65 or more, for example, oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and metal atoms thereof. A composite oxide or the like can be preferably used.
Such ultrafine particles may be obtained by treating the particle surface with a surface treatment agent (silane coupling agent, etc .: JP-A Nos. 11-295503, 11-153703, 2000-9908, anionic compounds or (Organic metal coupling agent: JP-A-2001-310432, etc.), core-shell structure with high refractive index particles as a core (JP-A-2001-166104, etc.) No. 153703, Patent No. US62010858B1, Japanese Patent Laid-Open No. 2002-27776069, etc.).

As the matrix material, conventionally known thermoplastic resins, curable resin films, and the like can be used, but JP-A-2000-47004, 2001-315242, 2001-31871, and 2001-296401. It is also possible to use a curable film obtained from a polyfunctional material described in a gazette or the like or a metal alkoxide composition described in JP-A-2001-293818 or the like.
The refractive index of the high refractive index layer is preferably 1.70 to 2.20. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.
The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70.

  The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. Further, the strength of the film is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K5400.

(Brightness enhancement film)
The polarizing plate of the present invention can be used in combination with a brightness enhancement film. The brightness enhancement film has a function of separating circularly polarized light or linearly polarized light, and is disposed between the polarizing plate and the backlight, and reflects or scatters one circularly polarized light or linearly polarized light back to the backlight side. Re-reflected light from the backlight part partially changes the polarization state and partially transmits when re-entering the brightness enhancement film and the polarizing plate, so the light utilization rate is improved by repeating this process. The front luminance is improved to about 1.4 times. As the brightness enhancement film, an anisotropic reflection system and an anisotropic scattering system are known, and both can be combined with the polarizing plate of the present invention.

In the anisotropic reflection system, a brightness enhancement film having anisotropy in reflectance and transmittance is known by laminating a uniaxially stretched film and an unstretched film in multiple layers and increasing the refractive index difference in the stretching direction. Multilayer film systems using the principle of dielectric mirrors (described in the specifications of WO95 / 17691, WO95 / 17692, WO95 / 17699) and cholesteric liquid crystal systems (European Patent No. 606940A2, Japanese Patent Laid-Open No. Hei 8- No. 271731) is known. DBEF-E, DBEF-D, and DBEF-M (all manufactured by 3M) are used as multi-layer brightness enhancement films using the principle of dielectric mirrors, and NIPOCS (Nitto Denko Corporation) as a cholesteric liquid crystal brightness enhancement film. )) Is preferably used in the present invention. For NIPOCS, see Nitto Giho, vol. 38, no. 1, may, 2000,
Reference can be made to pages 19-21.

  Further, in the present invention, positive numbers described in the specifications of WO97 / 32223, WO97 / 32224, WO97 / 32225, WO97 / 32226 and JP-A-9-274108 and 11-174231 are described. It is also preferable to use in combination with an anisotropic scattering type brightness enhancement film obtained by uniaxially stretching by blending an intrinsic birefringent polymer and a negative intrinsic birefringent polymer. As the anisotropic scattering system brightness enhancement film, DRPF-H (manufactured by 3M) is preferable.

(Other functional optical films)
The polarizing plate of the present invention is further combined with a functional optical film provided with a hard coat layer, a forward scattering layer, an antiglare (antiglare) layer, a gas barrier layer, a slipping layer, an antistatic layer, an undercoat layer, a protective layer and the like. It is also preferable to use it. These functional layers are also preferably used in combination with each other in the same layer as the antireflection layer in the above-mentioned antireflection film or the optically anisotropic layer in the viewing angle compensation film. These functional layers can be used by providing either one side or both sides of the polarizer side and the surface opposite to the polarizer (more air side surface).

[Hard coat layer]
The polarizing plate of the present invention is preferably combined with a functional optical film in which a hard coat layer is provided on the surface of a transparent support in order to impart mechanical strength such as scratch resistance. When the hard coat layer is applied to the above-described antireflection film, it is particularly preferable to provide it between the transparent support and the high refractive index layer.
The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of the curable compound by light and / or heat. The curable functional group is preferably a photopolymerizable functional group, and the hydrous functional group-containing organometallic compound is preferably an organic alkoxysilyl compound. As specific constitutional compositions of the hard coat layer, for example, those described in JP-A Nos. 2002-144913, 2000-9908 and WO0 / 46617 can be preferably used.
The film thickness of the hard coat layer is preferably 0.2 to 100 μm.
The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

  As the material for forming the hard coat layer, a compound containing an ethylenically unsaturated group or a compound containing a ring-opening polymerizable group can be used, and these compounds can be used alone or in combination. Preferred examples of the compound containing an ethylenically unsaturated group include ethylene glycol diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol. Polyacrylates of polyols such as hexaacrylate; epoxy acrylates such as diacrylate of bisphenol A diglycidyl ether, diacrylate of hexanediol diglycidyl ether; obtained by reaction of polyisocyanate and hydroxyl group-containing acrylate such as hydroxyethyl acrylate Examples of preferred compounds include urethane acrylates. Moreover, as a commercially available compound, EB-600, EB-40, EB-140, EB-1150, EB-1290K, IRR214, EB-2220, TMPTA, TMPTMA (above, Daicel UCB Co., Ltd. product), UV -6300, UV-1700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like.

  Preferred examples of the compound containing a ring-opening polymerizable group include ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, glycerol triglycidyl ether as glycidyl ethers. Triglycidyl trishydroxyethyl isocyanurate, sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, polyglycidyl ether of phenol novolac resin, etc. Celoxide 2021P, Celoxide 2081 GT-301, Epolide GT-401, EHPE3150CE (above, Oxetane, OXT-121, OXT-221, OX-SQ, PNOX-1009 (above, manufactured by Toagosei Co., Ltd.), etc. Can be mentioned. In addition, a polymer of glycidyl (meth) acrylate or a copolymer of a monomer that can be copolymerized with glycidyl (meth) acrylate may be used for the hard coat layer.

  In the hard coat layer, fine particles of oxide such as silicon, titanium, zirconium, and aluminum are used to reduce curing shrinkage of the hard coat layer, improve adhesion to the substrate, and reduce curling of the hard coat treated article of the present invention. It is also preferable to add crosslinked fine particles such as crosslinked fine particles such as polyethylene, polystyrene, poly (meth) acrylic acid esters, polydimethylsiloxane, etc., and fine organic particles such as fine crosslinked rubber particles such as SBR and NBR. These crosslinked fine particles preferably have an average particle size of 1 nm to 20000 nm. Further, the shape of the crosslinked fine particles can be used without particular limitation, such as a spherical shape, a rod shape, a needle shape, or a plate shape. The addition amount of the fine particles is preferably 60% by volume or less, more preferably 40% by volume or less of the hard coat layer after curing.

  In the case of adding the inorganic fine particles described above, since the affinity with the binder polymer is generally poor, it contains a metal such as silicon, aluminum, titanium, and the alkoxide group, carboxylic acid group, sulfonic acid group, phosphonic acid group, etc. It is also preferable to perform a surface treatment using a surface treatment agent having a functional group of

  The hard coat layer is preferably cured using heat or active energy rays. Among them, active energy rays such as radiation, gamma rays, alpha rays, electron rays, and ultraviolet rays are more preferred, and safety and productivity are improved. In view of the above, it is particularly preferable to use an electron beam or an ultraviolet ray. In the case of curing with heat, in consideration of the heat resistance of the plastic itself, the heating temperature is preferably 140 ° C. or lower, more preferably 100 ° C. or lower.

[Forward scattering layer]
The forward scattering layer is used to improve the viewing angle characteristics (hue and luminance distribution) in the vertical and horizontal directions when the polarizing plate of the present invention is applied to a liquid crystal display device. In the present invention, a configuration in which fine particles having different refractive indexes are dispersed in a binder is preferable. The construction of JP-A No. 199809, JP-A No. 2002-107512 or the like which defines the haze value as 40% or more can be used. In addition, in order to control the viewing angle characteristics of haze, the polarizing plate of the present invention is also preferably used in combination with “Lumisty” described in Sumitomo Chemical's technical report “Photofunctional Films” on pages 31-39. be able to.

[Anti-glare layer]
The antiglare (antiglare) layer is used to scatter reflected light and prevent reflection. The antiglare function is obtained by forming irregularities on the outermost surface (display side) of the liquid crystal display device. The haze of the optical film having an antiglare function is preferably 3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%.
The method for forming irregularities on the film surface is, for example, a method of forming irregularities on the film surface by adding fine particles (for example, JP-A No. 2000-271878), relatively large particles (particle size 0.05-2 μm). ) Is added in a small amount (0.1 to 50% by mass) (for example, Japanese Patent Application Laid-Open Nos. 2000-281410, 2000-95893, 2001-100004, and 2001). No. 281407, etc.), a method of physically transferring the uneven shape onto the film surface (for example, as an embossing method, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401) Etc.) can be preferably used.

<Liquid crystal display device>
Next, a liquid crystal display device in which a polarizing plate including the optical compensation sheet of the present invention is preferably used will be described with reference to the drawings.

FIG. 2 is a schematic view showing an example of a liquid crystal display device provided with the optical compensation sheet of the present invention.
2, the liquid crystal display device includes a liquid crystal cell and a pair of polarizing plates 1 and 14 disposed on both sides of the liquid crystal cell. A color filter may be disposed between the liquid crystal cell and the polarizing film. When used as a transmission type, a cold cathode or hot cathode fluorescent tube, or a backlight having a light emitting diode, field emission element, or electroluminescent element as a light source is disposed on the back surface. In the case of use as a reflection type, only one polarizing plate is required on the observation side, and a reflection film is provided on the back surface of the liquid crystal cell or the inner surface of the lower substrate of the liquid crystal cell. Of course, it is also possible to provide a front light using the light source on the liquid crystal cell observation side.

  In the present invention, at least one of the polarizing plates is a laminate of a transparent protective film, a polarizing film, a transparent protective film, and an optically anisotropic layer. Since the optical compensation sheet of the present invention can function as a protective film on one side of the polarizing film, the transparent protective film, the polarizing film, and the optical compensation sheet of the present invention (stretched polymer film and optically anisotropic layer) are laminated in this order. The integrated polarizing plate is preferable. In the liquid crystal display device, the transparent protective film, the polarizing film, and the optical compensation sheet (stretched polymer film and optically anisotropic layer) of the present invention are preferably laminated in this order from the outside of the device (the side far from the liquid crystal cell). . The liquid crystal display device includes an image direct view type, an image projection type, and a light modulation type. The present invention is effective for an active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as TFT or MIM. Of course, it is also effective in a passive matrix liquid crystal display device typified by STN mode called time-division driving.

(VA mode)
The liquid crystal display device of the present invention is preferably in the VA mode.
In the VA mode, the dielectric anisotropy between the upper and lower substrates is negative, and a liquid crystal having Δn = 0.0813 and Δε = −4.6 is rubbed to provide a director indicating the alignment direction of the liquid crystal molecules, a so-called tilt angle is about Create at 89 °. The thickness d of the liquid crystal layer 7 is set to 3.5 μm. Here, the brightness during white display changes depending on the size of the product Δnd of the thickness d and the refractive index anisotropy Δn. Therefore, in order to obtain the maximum brightness, it is set to be in the range of 0.2 to 0.5 μm.

  The absorption axis 2 of the upper polarizing plate 1 of the liquid crystal cell and the absorption axis 15 of the lower polarizing plate 14 are stacked approximately orthogonally. A transparent electrode (not shown) is formed inside each alignment film of the substrate 5 and the substrate 8, but in a non-driving state where no driving voltage is applied to the electrodes, the liquid crystal molecules in the liquid crystal layer 7 As a result, the polarization state of the light passing through the liquid crystal panel is hardly changed. That is, the liquid crystal display device realizes an ideal black display in the non-driven state. On the other hand, in the driving state, the liquid crystal molecules are inclined in a direction parallel to the substrate surface, and the light passing through the liquid crystal panel changes the polarization state by the inclined liquid crystal molecules. In other words, in the liquid crystal display device, white display is obtained in the driving state.

Here, since an electric field is applied between the upper and lower substrates, a liquid crystal material having a negative dielectric anisotropy is used so that liquid crystal molecules respond perpendicularly to the electric field direction. When an electrode is disposed on one substrate and an electric field is applied in a lateral direction parallel to the substrate surface, a liquid crystal material having a positive dielectric anisotropy is used.
In addition, in the VA mode liquid crystal display device, the addition of a chiral material generally used in the TN mode liquid crystal display device is rarely used to degrade the dynamic response characteristics, but in order to reduce alignment defects. Sometimes added.

  The features of the VA mode are high-speed response and high contrast. However, the contrast is high in the front, but there is a problem that it is deteriorated in the oblique direction. During black display, the liquid crystal molecules are aligned perpendicular to the substrate surface. When observed from the front, the liquid crystal molecules have almost no birefringence, so the transmittance is low and a high contrast can be obtained. However, when observed obliquely, birefringence occurs in the liquid crystal molecules. Further, the crossing angle of the upper and lower polarizing plate absorption axes is 90 ° perpendicular to the front, but is larger than 90 ° when viewed from an oblique direction. Because of these two factors, leakage light occurs in the oblique direction, and the contrast is lowered. In order to solve this, an optical compensation sheet is arranged.

  In addition, the liquid crystal molecules are tilted during white display, but the birefringence of the liquid crystal molecules when viewed from an oblique direction differs between the tilt direction and the opposite direction, resulting in differences in luminance and color tone. In order to solve this, a structure called a multi-domain in which one pixel of a liquid crystal display device is divided into a plurality of regions is employed.

[Multi-domain]
For example, in the VA system, the viewing angle characteristics are averaged by inclining liquid crystal molecules into different regions within one pixel by applying an electric field. In order to divide the orientation within one pixel, the electrode is provided with slits or protrusions to change the direction of the electric field or to bias the electric field density. In order to obtain a uniform viewing angle in all directions, the number of divisions may be increased, but a substantially uniform viewing angle can be obtained by dividing into four or eight or more. In particular, it is preferable that the polarizing plate absorption axis is set at an arbitrary angle when dividing into eight.

  In addition, liquid crystal molecules are difficult to respond at the alignment boundary. For this reason, in normally black display, since black display is maintained, a reduction in luminance becomes a problem. Therefore, it is possible to reduce the boundary region by adding a chiral agent to the liquid crystal material.

  Examples of the present invention will be described below, but the present invention is not limited thereto. In the following examples, “part” means “part by mass”.

[Example 1]
<Preparation of optical compensation sheet A-1>
(Preparation of stretched polymer film A-1)
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-5
―――――――――――――――――――――――――――――――――
Cyclic polyolefin: 150 parts by weight of ARTON-G Liquid paraffin: Daphne Oil CP68 (Idemitsu Kosan Co., Ltd.) 15 parts by weight Dichloromethane 450 parts by weight Surfactant RZ-13 0.7 parts by weight ――――――――― ―――――――――――――――――――――――

界面活性剤ＲＺ−１３
iso−Ｃ₈ Ｈ₁₇−Ｃ₆ Ｈ₄ −Ｏ−（ＣＨ₂ ＣＨ₂ Ｏ）₃ −（ＣＨ₂ ）₂ ＳＯ₃ Ｎａ

Surfactant RZ-13
_{iso-C 8 H 17 -C 6} H 4 -O- (CH 2 CH 2 O) 3 - (CH 2) 2 SO 3 Na

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-5
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle diameter of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 83 parts by mass Cyclic polyolefin solution D-5 10 parts by mass ――――――――――――――― ―――――――――――――――――

100 parts by mass of the cyclic polyolefin solution D-5 and 1.35 parts by mass of the fine particle dispersion M-5 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried at 120 ° C.
Furthermore, the film is heated to 1700C in the tenter, and the film is stretched 1.7 times in the direction perpendicular to the conveying direction, and then cooled in an atmosphere of 90C for 1 minute, and further cooled at room temperature. And it was taken out from the tenter to obtain a stretched polymer film (A-1). The thickness was 63 μm.
Re (480) / Re (546) was 1.01, and Re (628) / Re (546) was 0.99. Rth (480) / Rth (546) was 1.00, and Rth (628) / Rth (546) was 1.00. The photoelastic coefficient of the stretched polymer film A-1 was 2 × 10 ⁻⁸ cm ² / N.

(Coating of adhesion-imparting layer)
On both surfaces of the stretched polymer film (A-1) obtained above, a coating liquid having the following composition was applied so as to have a dry film thickness of 0.3 μm, and a hydrophobic cellulose ester-containing layer (DAC-containing layer) was formed. Formed.

(Composition of coating solution)
Cellulose diacetate (DAC: Acetate Flakes L-AC, Daicel Chemical Industries)
(Made in 5 mass% acetone solution) 50 ml
40 ml of ethyl acetate
10 ml of methanol
Aerosil R-972 (manufactured by Nippon Aerosil Co., Ltd .: prepared by dispersing so that the average particle size is 0.3 μm in the layer) 1 g

(Formation of alignment layer)
On one surface of the stretched polymer film (A-1) coated with the adhesion-imparting layer, a coating solution having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 90 ° C. for 150 seconds.
Next, rubbing treatment was performed on the formed film in the direction of 90 ° with the stretching direction of the stretched polymer film (A-1) (almost coincident with the slow axis).

────────────────────────────────────
Alignment film coating solution composition
────────────────────────────────────
The following modified polyvinyl alcohol 20 parts by mass Water 360 parts by mass Methanol 120 parts by mass Glutaraldehyde (crosslinking agent) 1.0 part by mass─────────────────────── ─────────────

(Preparation of optically anisotropic layer)
On the alignment film, a coating solution having the following composition was applied by 23.1 ml / m ² with a # 6 wire bar coater. This was attached to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the liquid crystalline compound. Next, UV irradiation was performed for 1 minute using a 120 W / cm high pressure mercury lamp at 90 ° C. to polymerize the liquid crystalline compound. Then, it stood to cool to room temperature.

─────────────────────────────────────
Optically anisotropic layer coating composition ─────────────────────────────────────
Rod-like liquid crystalline compound I-6 100 parts by mass Crosslinkable group-containing polymer (1) 0.7 part by weight Fluoropolymer (Megafac F-780-F, manufactured by Dainippon Ink & Chemicals, Inc.)
0.5 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 2.9 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 part by mass Methyl ethyl ketone 262 parts by mass ──────────────────────────────────

Re (480) / Re (546) of the optically anisotropic layer was 1.11 and Re (628) / Re (546) was 0.95. Rth (480) / Rth (546) was 1.11 and Rth (628) / Rth (546) was 0.95.
The slow axis of the stretched polymer film A-1 and the slow axis of the optically anisotropic layer were arranged so as to be orthogonal to each other.

[Example 2]
<Preparation of optical compensation sheet A-2>
(Preparation of stretched polymer film A-2)
100 parts by mass of the cyclic polyolefin solution D-5 and 1.35 parts by mass of the fine particle dispersion M-5 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried at 120 ° C.
Further, the film was heated to 1700C in a tenter, and the film was stretched 1.5 times in the direction perpendicular to the conveying direction, and then cooled while maintaining this state for 1 minute in an atmosphere of 90C. The cooled polymer film (A-2) was obtained by cooling and taking out from the tenter. The thickness was 69 μm.
Re (480) / Re (546) was 1.01, and Re (628) / Re (546) was 0.99. Rth (480) / Rth (546) was 1.00, and Rth (628) / Rth (546) was 1.00. The photoelastic coefficient of the stretched polymer film A-1 was 1 × 10 ⁻⁸ cm ² / N.
The slow axis of the stretched polymer film A-2 and the slow axis of the optically anisotropic layer were arranged so as to be orthogonal.

(Film surface treatment)
Kasuga Denki Co., Ltd. corona discharge was applied to both surfaces of the stretched polymer film (A-2) under conditions of 12 W · min / m ² to impart hydrophilicity.

(Formation of alignment layer)
On the surface of the stretched polymer film (A-2), a coating solution having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 90 ° C. for 150 seconds.
Next, rubbing treatment was performed on the formed film in the direction of 90 ° with the stretching direction of the stretched polymer film (A-2) (almost coincident with the slow axis).

────────────────────────────────────
Alignment film coating solution composition ─────────────────────────────────────
The following modified polyvinyl alcohol 20 parts by weight Water 360 parts by weight Methanol 120 parts by weight Glutaraldehyde (crosslinking agent) 1.0 part by weight ─────────────────────── ─────────────

(Preparation of optically anisotropic layer)
On the alignment film, 15.4 ml / m ² of a coating solution having the following composition was applied using a # 4 wire bar coater. This was attached to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the liquid crystalline compound. Next, UV irradiation was performed for 1 minute using a 120 W / cm high pressure mercury lamp at 90 ° C. to polymerize the liquid crystalline compound. Then, it stood to cool to room temperature.

────────────────────────────────────
Optically anisotropic layer coating composition ─────────────────────────────────────
Rod-like liquid crystalline compound I-1 100 parts by mass Crosslinkable group-containing polymer (1) 0.7 part by weight Fluorine-based polymer (Megafac F-780-F, manufactured by Dainippon Ink and Co., Ltd.)
0.5 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 2.9 parts by mass Sensitizer (KayaCure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 part by mass Methyl ethyl ketone 253 parts by mass ─────────────────────────────────

  The optically anisotropic layer had Re (480) / Re (546) of 1.05 and Re (628) / Re (546) of 0.97. Rth (480) / Rth (546) was 1.05, and Rth (628) / Rth (546) was 0.97.

[Comparative Example 1]
<Preparation of optical compensation sheet B-1>
(Preparation of cellulose acylate film B-1)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution B.

―――――――――――――――――――――――――――――――――
Cellulose acylate solution B composition ―――――――――――――――――――――――――――――――――
Cellulose acylate with acetylation degree 1.0 and propionylation degree 1.4
100.0 parts by mass Triphenyl phosphate (plasticizer) 9.0 parts by mass Ethylphthalylethyl glycolate (plasticizer) 3.5 parts by mass Methylene chloride (first solvent) 362.0 parts by mass Ethanol (second solvent) ) 100.0 parts by mass ―――――――――――――――――――――――――――――――――

<Preparation of matting agent solution>
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent solution.

――――――――――――――――――――――――――――――――
Matting agent solution composition ――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd. 2.0 parts by mass Methylene chloride (first solvent) 75.0 parts by mass Ethanol (second solvent) 12.7 parts by mass Cellulose acylate solution B 10.3 parts by mass ――――――――――――――――――――――――――――――――

<Preparation of additive solution>
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an ultraviolet absorber solution.

―――――――――――――――――――――――――――――――
UV absorber solution composition ―――――――――――――――――――――――――――――――
UV absorber (A) 4.0 parts by weight UV absorber (B) 2.0 parts by weight Methylene chloride (first solvent) 75.2 parts by weight Ethanol (second solvent) 11.2 parts by weight ――――――――――――――――――――――――――

UV absorber (A)

UV absorber (B)

  1.3 parts by weight of the above matting agent solution and 6.0 parts by weight of the UV absorber solution are filtered and mixed by an in-line mixer, and 92.7 parts by weight of cellulose acylate solution B is further added and mixed by an in-line mixer. Then, it was cast using a band casting machine. The film was peeled off from the band with a residual solvent content of 36% by mass, stretched to 40% with a tenter at an ambient temperature of 130 ° C., and then held at 140 ° C. for 30 seconds. The residual solvent content at the start of stretching was 15% by mass. Thereafter, the clip was removed and dried at 130 ° C. for 40 minutes to produce a cellulose acylate film. The resulting cellulose acylate film had a residual solvent amount of 0.1% by mass and a film thickness of 90 μm.

(Alkaline treatment of film)
Cellulose acylate film B-1 was immersed in a 2.3 mol / L aqueous sodium hydroxide solution at 55 ° C. for 3 minutes. It wash | cleaned in the room temperature water-washing bath, and neutralized using 0.05 mol / L sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C.
Thus, the optical compensation sheet B-1 of the comparative example was produced.

[Comparative Example 2]
<Preparation of optical compensation sheet B-2>
(Preparation of cellulose acylate film B-2)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution C.

―――――――――――――――――――――――――――――――――
Cellulose acylate solution C composition ―――――――――――――――――――――――――――――――――
Cellulose acylate with acetylation degree 1.1 and propionylation degree 1.5
100.0 parts by mass Triphenyl phosphate (plasticizer) 9.0 parts by mass Ethylphthalyl ethyl glycolate (plasticizer) 3.5 parts by mass Methylene chloride (first solvent) 362.0 parts by mass Ethanol (second solvent) ) 100.0 parts by mass ―――――――――――――――――――――――――――――――――

<Preparation of matting agent solution>
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent solution.

――――――――――――――――――――――――――――――――
Matting agent solution composition ――――――――――――――――――――――――――――――――
Silica particles having an average particle diameter of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd. 2.0 parts by mass Methylene chloride (first solvent) 75.0 parts by mass Ethanol (second solvent) 12.7 parts by mass Cellulose acylate solution C 10.3 parts by mass ――――――――――――――――――――――――――――――――

<Preparation of additive solution>
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an ultraviolet absorber solution.

―――――――――――――――――――――――――――――――
UV absorber solution composition ―――――――――――――――――――――――――――――――
UV absorber (A) 4.0 parts by weight UV absorber (B) 2.0 parts by weight Methylene chloride (first solvent) 75.2 parts by weight Ethanol (second solvent) 11.2 parts by weight ――――――――――――――――――――――――――

  1.3 parts by weight of the above matting agent solution and 6.0 parts by weight of the UV absorber solution are filtered and mixed by an in-line mixer, and 92.7 parts by weight of cellulose acylate solution B is further added and mixed by an in-line mixer. Then, it was cast using a band casting machine. The film was peeled off from the band with a residual solvent content of 36% by mass, and stretched to 20% with a tenter at an ambient temperature of 130 ° C., and then held at 140 ° C. for 30 seconds. The residual solvent content at the start of stretching was 15% by mass. Thereafter, the clip was removed and dried at 130 ° C. for 40 minutes to produce a cellulose acylate film. The resulting cellulose acylate film had a residual solvent amount of 0.1% by mass and a film thickness of 96 μm.

(Alkaline treatment of film)
Cellulose acylate film B-2 was immersed in an aqueous 1.5 N sodium hydroxide solution at 55 ° C. for 3 minutes. It wash | cleaned in the room temperature water-washing tub, and neutralized using 0.1 N sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. Thus, the optical compensation sheet B-2 of the comparative example was produced.

<Measurement of film properties>
(Measurement of optical properties)
Re and Rth were measured at 25 ° C. and 60% RH using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). The measurement wavelengths were 480 nm, 546 nm, and 628 nm.

(Measurement of photoelastic modulus)
The film was cut into 3.5 cm × 12 cm, Re was measured for each load of no load, 250 g, 500 g, 1000 g, and 1500 g, and the photoelastic modulus was calculated from the slope of the straight line of the Re change with respect to the stress. The measurement wavelength was 630 nm.

  Table 1 shows the measurement results of film properties.

Example 3
<Preparation of polarizing plate>
(Saponification treatment of stretched polymer film)
A commercially available cellulose acylate film (Fujitac TD80) was immersed in a 1.5 mol / L aqueous sodium hydroxide solution at 55 ° C. for 1 minute. It wash | cleaned in the room temperature water-washing bath, and neutralized using 0.05 mol / L sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C.

(Creating a polarizer)
A polyvinyl alcohol film having a polymerization degree of 1700 and a thickness of 39 μm was swelled in a 30 ° C. hot water bath, and then stretched about 4 times in a 30 ° C. dyeing bath composed of an aqueous solution of iodine and potassium iodide. Next, the film was stretched in a 50 ° C. crosslinking bath containing boric acid and potassium iodide so that the total draw ratio was 5.5 times, and crosslinked. This was immersed in an aqueous solution of potassium iodide at 35 ° C. for 10 seconds to adjust the hue. Further, it was washed with water and dried to obtain a polarizer having a thickness of 18 μm. The water content of this polarizer was 14%. The birefringence (Δn) at a wavelength of 900 nm was 0.0482, the transmittance was 43%, and the degree of polarization was 99.9%.

  In addition, the birefringence was calculated | required by calculating | requiring a phase difference value ((DELTA) nd) with the wavelength light of 900 nm using the parallel Nicol rotation method, and dividing by thickness d (nm).

  The transmittance is a Y value measured using a spectrophotometer (Murakami Color Research Laboratory, DOT-3) and corrected for visibility using a JIS Z8701 two-degree field of view (C light source).

  The degree of polarization is obtained by measuring the transmittance (H90) obtained by superimposing the transmittance (H0) when two identical polarizers are superposed so that the polarization axes are parallel to each other. And was calculated from the following formula. The polarized light transmittance (H0) and the orthogonal transmittance (H90) are Y values corrected for visibility. Polarization degree (%) = √ {(H0−H90) / (H0 + H90)} × 100

(Preparation of adhesive)
10 parts of polyester urethane (Mitsui Takeda Chemicals, Takelac XW-74-C154) and 1 part of isocyanate crosslinking agent (Mitsui Takeda Chemicals, Takenate WD-725) are dissolved in water and the solid content is 20%. A solution adjusted to 1 was prepared. This was used as an adhesive.

(Preparation of polarizing plate 1)
After the adhesive solution is applied to both sides of the polarizer, the optical compensation sheet A-1 prepared in Example 1 and the saponified Fuji Tac TD80 prepared above are bonded together so as to sandwich the polarizer. The plate 1 was dried and cured in an oven at 40 ° C. for 72 hours to prepare the polarizing plate 1. The optical compensation sheet A-1 was bonded so that the optical anisotropy was on the air side. The polarizing plate obtained had a transmittance of 42% and a polarization degree of 99.9%.

(Preparation of polarizing plate 2)
After the adhesive solution is applied to both surfaces of the polarizer, the optical compensation sheet A-2 prepared in Example 2 and the saponified Fuji Tac TD80 prepared above are bonded together so as to sandwich the polarizer. The plate 2 was dried and cured in an oven at 40 ° C. for 72 hours to prepare the polarizing plate 2. The optical compensation sheet A-2 was bonded so that the optical anisotropy was on the air side. The polarizing plate obtained had a transmittance of 41% and a polarization degree of 99.9%.

[Comparative Example 3]
(Preparation of polarizing plate 3)
In the same manner as in Example 3, the optical compensation sheet film B-1 produced in Comparative Example 1 and the saponified Fuji Tac TD80 produced above were bonded together with a polarizer sandwiched between them, and 72 in a 40 ° C. oven. The polarizing plate 3 was produced by drying for hours. The polarizing plate obtained had a transmittance of 43% and a degree of polarization of 99.9%.

(Preparation of polarizing plate 4)
In the same manner as in Example 3, the optical compensation sheet film B-2 prepared in Comparative Example 2 and the saponified Fuji Tac TD80 prepared above were bonded together so as to sandwich the polarizer, and the film was 72 in an oven at 40 ° C. Curing was performed for a time to prepare a polarizing plate 4. The polarizing plate obtained had a transmittance of 42% and a polarization degree of 99.9%.

[Example 4]
The liquid crystal display device of FIG. 3 was produced. That is, an upper polarizing plate, a VA mode liquid crystal cell (upper substrate, liquid crystal layer, lower substrate) and a lower polarizing plate were laminated from the observation direction (upper), and a backlight light source was further arranged. In the following example, a commercially available polarizing plate (HLC2-5618) is used for the upper polarizing plate, and polarizing plates 1 to 4 are used for the lower polarizing plate.

<Production of liquid crystal cell>
The liquid crystal cell has a cell gap between substrates of 3.6 μm, and a liquid crystal material having negative dielectric anisotropy (“MLC6608”, manufactured by Merck & Co., Inc.) is dropped and sealed between the substrates. Was formed. The retardation of the liquid crystal layer (that is, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn) was 275 nm. The liquid crystal material was aligned so as to be vertically aligned.

A commercially available super high contrast product (HLC2-5618 manufactured by Sanlitz Co., Ltd.) is used for the upper polarizing plate of the liquid crystal display device (FIG. 3) using the vertical alignment type liquid crystal cell, and Example 3 is used for the lower polarizing plate. The liquid crystal display device 1 is produced by attaching the polarizing plate 1 produced in step 1 to the viewer side and the backlight side one by one through an adhesive so that the optical compensation sheet (A-1) is on the liquid crystal cell side. did. The crossed nicols were arranged so that the transmission axis of the polarizing plate on the observer side was in the vertical direction and the transmission axis of the polarizing plate on the backlight side was in the horizontal direction.

[Comparative Example 4]
A liquid crystal display device 2 was also produced for the polarizing plate 3 in the same manner as in Example 4.

<Evaluation of color change>
The liquid crystal display device produced in Example 4 and Comparative Example 4 was measured for the change in front color immediately after being lit in an environment of 30 ° C. and 80% RH and after being lit for 500 hours by Ezcontrast manufactured by ELDIM, and on the xy chromaticity diagram. The absolute values Δx and Δy of the color change at γ were obtained.
The results are shown in Table 2.

  From the results shown in Table 2, it was found that the polarizing plate using the optical compensation sheet of the present invention is preferable because it has little color change even when it is lit for a long time when incorporated in a liquid crystal display device.

[Example 5]
[Production and evaluation of VA liquid crystal display device 2]
1% by weight of octadecyldimethylammonium chloride (coupling agent) was added to a 3% by weight aqueous solution of polyvinyl alcohol. This was spin-coated on a glass substrate with an ITO electrode, heat-treated at 160 ° C., and then rubbed to form a vertical alignment film. The rubbing treatment was performed in opposite directions on the two glass substrates. Two glass substrates were opposed to each other so that the cell gap (d) was 5 μm. A liquid crystal compound (Δn: 0.08) mainly composed of ester and ethane was injected into the cell gap to prepare a vertically aligned liquid crystal cell. The product of Δn and d was 400 nm.

  The polarizing plate 2 produced above was stuck on both surfaces of the produced vertical alignment liquid crystal cell using the adhesive sheet so that the optical compensation sheet (A-2) side might become a cell side, and the liquid crystal display device 3 was produced.

[Comparative Example 5]
In the same manner as in Example 5, the above-prepared polarizing plate 4 was attached to both surfaces of a vertically aligned liquid crystal cell using an adhesive sheet, to produce a liquid crystal display device 4.

<Evaluation of color change>
The change in color of the liquid crystal display produced in Example 5 and Comparative Example 5 immediately after lighting in an environment of 30 ° C. and 80% RH and after lighting for 1000 hours was measured by Ezcontrast manufactured by ELDIM, and on the xy chromaticity diagram. The absolute values Δx and Δy of the color change were obtained.
The results are shown in Table 3.

  From the results shown in Table 3, it was found that the polarizing plate using the optical compensation sheet of the present invention is preferable because it has little color change even when it is lit for a long time when incorporated in a liquid crystal display device.

It is the schematic which shows the example of the polarizing plate of this invention. It is the schematic which shows the example of the liquid crystal display device of this invention. 6 is a schematic diagram illustrating a configuration example of a liquid crystal display device of Example 4. FIG.

Explanation of symbols

1, 1a, 3 Protective film 2 Polarizer 3 Optical anisotropic layer 4 Stretched polymer film
1 ... Upper polarizing plate
2 ... Upper polarizing plate absorption axis
3 ... 1st optical anisotropic layer
4 .. direction of slow axis of the first optically anisotropic layer
5 ... Electrode substrate on liquid crystal cell
6 ... Upper substrate orientation control direction
7 Liquid crystal layer
8 LCD panel lower electrode substrate
9 ... Lower substrate orientation control direction
10 ... 2nd optically anisotropic layer 1
11 ... 2nd optically anisotropic layer 1 slow axis direction
12 ... 2nd optical anisotropic layer 2
13 ... 2nd optically anisotropic layer 2 Slow axis direction
14 ... Lower polarizing plate
15 ... Direction of absorption axis of lower polarizing plate

Claims (9)

An optical compensation sheet having an optically anisotropic layer containing at least one liquid crystal compound on a stretched polymer film, wherein the retardation satisfies the following relationships (A) to (F).
30 nm <Re (546) <150 nm (A)
100 nm <Rth (546) <400 nm (B)
0.5 <Re (480) / Re (546) <1 (C)
1.0 <Re (628) / Re (546) <2.0 (D)
1.0 <Rth (480) / Rth (546) <1.5 (E)
0.7 <Rth (628) / Rth (546) <1.0 (F)
(However, Re (λ) is in-plane retardation (nm) at wavelength λ, and Rth (λ) is retardation in the thickness direction at wavelength λ (nm).)   2. The optical compensation sheet according to claim 1, wherein the slow axis of the stretched polymer film and the slow axis of the optically anisotropic layer containing the liquid crystal compound are orthogonal to each other. 3. The optical compensation sheet according to claim 1, wherein the retardation of the stretched polymer film satisfies the following formulas (G) to (J).
0.95 <Re (480) / Re (546) <1.05 (G)
0.95 <Re (628) / Re (546) <1.05 (H)
0.95 <Rth (480) / Rth (546) <1.05 (I)
0.95 <Rth (628) / Re (546) <1.05 (J)
(However, Re (λ) is in-plane retardation (nm) at wavelength λ, and Rth (λ) is retardation in the thickness direction at wavelength λ (nm).) The optical compensation sheet according to any one of claims 1 to 3, wherein the retardation of the optically anisotropic layer satisfies the following formulas (K) to (N).
1.0 <Re (480) / Re (546) <2.0 (K)
0.5 <Re (628) / Re (546) <1.0 (L)
1.0 <Rth (480) / Rth (546) <2.0 (M)
0.5 <Rth (628) / Rth (546) <1.0 (N)
(However, Re (λ) is in-plane retardation (nm) at wavelength λ, and Rth (λ) is retardation in the thickness direction at wavelength λ (nm).) 5. The optical compensation sheet according to claim 1, wherein the stretched polymer film has a photoelastic coefficient of 5 × 10 ⁻¹³ cm ² / dyn (5 × 10 ⁻⁸ cm ² / N) or less. .   6. The optical compensation sheet according to claim 1, wherein the stretched polymer film is a cycloolefin polymer film.   A polarizing plate comprising a polarizer and two protective films disposed on both sides thereof, wherein at least one protective film is the optical compensation sheet according to any one of claims 1 to 6. Polarizer.   A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein at least one polarizing plate is the polarizing plate according to claim 7.   The liquid crystal display device according to claim 8, wherein the liquid crystal cell is in a VA mode.

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