JP2009083308A - Method for producing cyclic olefin film - Google Patents

Abstract

An object of the present invention is to provide a method for producing a cyclic olefin film having appropriate optical characteristics by reducing the in-plane retardation Re and suppressing the occurrence of uneven stripes and scratches.
A method for producing a cyclic olefin film comprising a step of heating a film-like material by conveying the film-like material containing a cyclic olefin-based resin and passing the film-like material through the heating region, the method comprising: A method for producing a cyclic olefin film, characterized in that the elastic modulus of the film-like material at a temperature of 300 MPa to 3000 MPa and a conveying tension of 10 to 50 (N / film 1 m width).
[Selection figure] None

Description

  The present invention relates to a method for producing a cyclic olefin film, and more particularly, to a method for producing a cyclic olefin film having good optical properties with suppressed generation of stripes and scratches.

  The polarizing plate is usually produced by bonding a protective film mainly composed of cellulose triacetate on both sides of a polarizing film in which iodine or a dichroic dye is oriented and adsorbed on polyvinyl alcohol. Cellulose triacetate is widely used as the above-mentioned protective film for polarizing plate because of its characteristics such as toughness, flame retardancy, and high optical isotropy (low retardation value). The liquid crystal display device includes a polarizing plate and a liquid crystal cell. Currently, as described in Patent Document 1, a liquid crystal display device with high display quality is realized by inserting an optical compensation sheet (also referred to as an optical compensation film) between a polarizing plate and a liquid crystal cell. However, the cellulose triacetate film has a large amount of moisture absorption, and therefore has a problem that the dimensional stability is inferior, the optical compensation performance is changed, and the film is easily peeled from the polarizer.

Therefore, there is an attempt to solve the above problem with a film other than cellulose triacetate.
Polycarbonate (PC), polyethylene terephthalate (PET), cyclic olefin-based resin and the like are candidates, but optical properties such as a protective film application for polarizing plates, particularly relatively high Rth values such as VA application (thickness direction) When the retardation value is required, a cyclic olefin resin having a planar polymer structure is suitable (for example, Patent Documents 2 to 4).

However, in the production of a film made of a cyclic olefin-based resin, the film is stretched to obtain desired optical characteristics, and further, heat treatment is performed in the heating region after stretching, and the film is conveyed in the heating region. When the tension at the time is too high, MD draw (force in the film transport direction) relaxes the orientation in the TD direction (stretching direction, direction perpendicular to MD) expressed by stretching, reducing in-plane retardation Re, Unevenness occurs. Further, there is a problem that scratches occur when the tension is too low.
JP-A-8-50206 JP 2003-212927 A Japanese Patent Laid-Open No. 2002-114827 JP 2007-9010 A

  An object of the present invention is to provide a method for producing a cyclic olefin film having an appropriate optical characteristic by overcoming the above-mentioned problems of the prior art, suppressing Re, reducing the occurrence of uneven stripes and scratches.

The present invention has the following configuration.
[1] A method for producing a cyclic olefin film comprising a step of heating a film-like material by conveying the film-like material containing a cyclic olefin-based resin and passing the film-like material through the heating region, A method for producing a cyclic olefin film, characterized in that an elastic modulus of the film-like material at a temperature is 300 MPa to 3000 MPa, and a conveying tension is 10 to 50 (N / film width of 1 m).

[2] When the elastic modulus of the film-like material at the temperature in the heating region is E (MPa) and the film thickness is h (μm), E × h ³ is 1.0 × 10 ⁷ or more and 3.0. × 10 ⁹ or less, when the in-plane retardation of the film-like material before heating is (before Re heat treatment) and the in-plane retardation after heating is (after Re heat treatment), (after Re heat treatment) / ( The method for producing a cyclic olefin film according to the above [1], wherein (before Re heat treatment) is 0.75 or more and 1.0 or less.

[3] The cyclic olefin film contains 1% by mass or more and 35% by mass or less of at least one of the compounds represented by the following general formulas (1) to (5) with respect to the cyclic olefin-based resin. The method for producing a cyclic olefin film according to the above [1] or [2], which is characterized by the following.

In General Formula (1), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. The total number of carbon atoms of R ¹ , R ² and R ³ is 10 or more.
In general formula (2), R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more.
In general formula (3), R ¹¹ represents an aryl group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and at least one of them is an aryl group. Moreover, the alkyl group and the aryl group may each have a substituent.
In the general formula (4), R ²¹ , R ²² and R ²³ each independently represents an alkyl group. Moreover, each alkyl group may have a substituent.
In the general formula (5), R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. X ³¹ , X ³² , X ³³ and X ³⁴ are each a single bond, —CO— and NR ³⁵ — (R ³⁵ represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group). Represents a divalent linking group formed from one or more groups selected from the group consisting of: a, b, c and d are integers of 0 or more, and a + b + c + d is 2 or more. Z ³¹ represents an (a + b + c + d) -valent organic group (excluding a cyclic group).

[4] The cyclic olefin film contains at least one compound having a structure represented by the following general formula (9) or (10) in an amount of 1% by mass to 35% by mass with respect to the cyclic olefin resin. The method for producing a cyclic olefin film as described in [1] or [2] above.

In the general formulas (9) and (10), R ^{41 to} R ⁴⁸ may each independently have a linking group containing a hydrogen atom; a halogen atom; an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. Represents a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group, and R ⁴⁴ are all bonded to one another, whether they are the same atom or group, or different atoms or groups. In addition, a carbocycle or a heterocycle (these carbocycles and heterocycles may have a monocyclic structure, or other rings may be condensed to form a polycyclic structure).

[5] The method for producing a cyclic olefin film according to any one of [1] to [4], wherein the cyclic olefin film has a thickness of 30 μm to 100 μm.

  According to the present invention, it is possible to provide a method for producing a cyclic olefin film having excellent optical properties by suppressing the occurrence of uneven stripes and scratches and the reduction of Re after heat treatment.

Hereinafter, the present invention will be described in detail.
In this specification, “(numerical value 1) to (numerical value 2)” and “(numerical value 1) to (numerical value 2)” mean “(numerical value 1) or more and (numerical value 2) or less”.

First, the cyclic olefin film of the present invention (hereinafter also referred to as a cyclic polyolefin film) will be described.
The cyclic polyolefin film of the present invention has a cyclic olefin resin solution (hereinafter also referred to as a cyclic polyolefin resin solution or a dope) containing at least a cyclic olefin resin (also referred to as a cyclic polyolefin resin or a cyclic polyolefin) on a support. The film is manufactured through a casting process, a process in which the cast dope is made into a film-like product by drying or the like, a stretching process, a drying process after stretching, a winding process, and the like.

(Cyclic polyolefin resin)
In the present invention, the cyclic polyolefin resin represents a polymer resin having a cyclic polyolefin structure.
Examples of the polymer resin having a cyclic olefin structure used in the present invention include (1) a norbornene polymer, (2) a monocyclic olefin polymer, (3) a cyclic conjugated diene polymer, (4
) Vinyl alicyclic hydrocarbon polymers and hydrides of (1) to (4). The polymer resin preferably used in the present invention is an addition (co) polymer cyclic polyolefin containing at least one repeating unit represented by the following general formula (7) and, if necessary, the general formula (6). An addition (co) polymer cyclic polyolefin further comprising at least one or more repeating units. A ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (8) can also be suitably used.

In formula, m represents the integer of 0-4. R ^{1 to} R ⁶ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. A substituted hydrocarbon group having 1 to 10 carbon atoms, — (CH ₂ ) _n COOR ¹¹ , — (CH ₂ ) _n OCOR ¹² , — (CH ₂ ) _n NCO, — (CH ₂ ) _n NO ₂ , — ( _{CH 2) n CN, - (} CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2) n W or X ¹ and Y ^1, Alternatively, (—CO) ₂ O and (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p. D _{3 -p} (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom, —OCOR ¹⁵ or —OR ¹⁶ , p is an integer of 0 to 3), n is an integer of 0 to 10 Show.

By introducing a polarizable large functional group in a substituent ^{X 1 ~X 3, Y 1 ~Y} 3, a thickness direction retardation (Rth) of the film is increased, the expression of the in-plane retardation (Re) The sex can be increased. A film having a high Re developability can increase the Re value by stretching in the film forming process.

  As the norbornene-based addition (co) polymer, those disclosed in JP-A No. 10-7732, JP-A No. 2002-504184, US2004229157A1 or International Publication No. 2004 / 070463A1 may be used. it can. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and conjugated dienes such as ethylene, propylene, butene, butadiene and isoprene; non-conjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. As this norbornene type addition (co) polymer, a commercial item can also be used. Specifically, grades such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C), or APL6015T (Tg145 ° C), which are sold under the trade name of Apel from Mitsui Chemicals, Inc. and have different glass transition temperatures (Tg), are used. There is. Pellets such as TOPAS 8007, 6013, and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

Norbornene polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-1159767 or As disclosed in Japanese Patent Application Laid-Open No. 2004-309979 and the like, it is possible to use a polycyclic unsaturated compound produced by addition polymerization or metathesis ring-opening polymerization and then hydrogenation. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. The This norbornene-based resin may be a commercially available product. Specifically, JSR Co., Ltd. is sold under the trade name of Arton G or Arton F, and ZEONOR from Nippon Zeon Co., Ltd. ) ZF14, ZF16, Zeonex 250, or Zeonex 280 are commercially available and can be used.

  The cyclic polyolefin resin used in the present invention preferably has a mass average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 5,000 to 1,000,000 in terms of polystyrene molecular weight. More preferably, it is 10,000-500,000, and it is further more preferable that it is 50,000-300,000. Moreover, it is preferable that molecular weight distribution (Mw / Mn; Mn is the number average molecular weight measured by GPC) is 10 or less, More preferably, it is 5.0 or less, More preferably, it is 3.0 or less. The glass transition temperature (Tg; measured by DSC) is preferably 50 to 350 ° C, more preferably 80 to 330 ° C, and still more preferably 100 to 300 ° C.

(Additive)
The dope preferably contains at least one of the additives represented by the following general formulas (1) to (5) as an additive together with the cyclic polyolefin resin.

First, the additives of the general formulas (1) and (2) will be described.
In the general formula (1), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Further, the total number of carbon atoms of R ¹ , R ² and R ³ is particularly preferably 10 or more. In the general formula (2), R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. R ⁴
And the total number of carbon atoms of R ⁵ is 10 or more, and each of the alkyl group and aryl group may have a substituent. As the substituent, a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are preferable, and an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are particularly preferable. Further, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and more preferably 6 to 20 (E.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, heptyl, octyl, bicyclooctyl, nonyl, adamantyl, decyl, t-octyl, undecyl, Dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, didecyl) are particularly preferred. As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, triphenylphenyl) are particularly preferable. Although the preferable example of a compound represented by General formula (1) or General formula (2) is shown below, this invention is not limited to these specific examples.

Next, the additive of General formula (3), (4), (5) is demonstrated.
In general formula (3), R ¹¹ represents an aryl group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and at least one of them is an aryl group. Moreover, the alkyl group and the aryl group may each have a substituent.
In the general formula (4), R ²¹ , R ²² and R ²³ each independently represents an alkyl group. Moreover, each alkyl group may have a substituent.
In the general formula (5), R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. X ³¹ , X ³² , X ³³ and X ³⁴ are each a single bond, —CO— and NR ³⁵ — (R ³⁵ is a substituted or unsubstituted aliphatic group,
Or a divalent linking group formed from one or more groups selected from the group consisting of a substituted or unsubstituted aromatic group. a, b, c and d are integers of 0 or more, and a + b + c + d is 2 or more. Z ³¹ represents an (a + b + c + d) -valent organic group (excluding a cyclic group).

In the above general formula (3), R ¹¹ represents an aryl group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and at least one of them is an aryl group. When R ¹² is an aryl group, R ¹³ may be an alkyl group or an aryl group, but more preferably an alkyl group. Here, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and 1 to 12 carbon atoms. Is most preferred. The aryl group preferably has 6 to 36 carbon atoms, and more preferably 6 to 24 carbon atoms.

In the general formula (4), R ²¹ , R ²² and R ²³ each independently represents an alkyl group. Here, the alkyl group may be linear, branched or cyclic. R ²¹ is preferably a cyclic alkyl group, and more preferably at least one of R ²² and R ²³ is a cyclic alkyl group. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 12 carbon atoms. As the cyclic alkyl group, a cyclohexyl group is particularly preferable.

  The alkyl group and aryl group in the general formulas (3) and (4) may each have a substituent. Substituents include halogen atoms (for example, chlorine, bromine, fluorine and iodine), alkyl groups, aryl groups, alkoxy groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, acyloxy groups, sulfonylamino groups, A hydroxy group, a cyano group, an amino group and an acylamino group are preferred, more preferably a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a sulfonylamino group and an acylamino group, and particularly preferably an alkyl group and an aryl group. A sulfonylamino group and an acylamino group.

Next, although the preferable example of a compound represented by General formula (3) or (4) is shown below, this invention is not limited to these specific examples.
In addition, the compound attached | subjected with (A-) is a specific example of a compound represented by General formula (3), and the compound attached | subjected with (B-) is represented by General formula (4) This is a specific example.

  Any of the above compounds can be produced by a known method. That is, the compounds of the general formula (3) and the general formula (4) are obtained by dehydration condensation reaction between carboxylic acids and amines using a condensing agent {for example, dicyclohexylcarbodiimide (DCC), etc.], or carboxylic acid chloride derivatives and amines. It can be obtained by a substitution reaction with a derivative.

Next, the compound represented by the general formula (5) will be described in detail.
In the general formula (5), R ³¹ , R ³² , R ³³ and R ³⁴ each represents a hydrogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group, and an aliphatic group Is preferred. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable.

X ³¹ , X ³² , X ³³ and X ³⁴ are each a single bond, —CO— and NR ³⁵ — (R ³⁵ represents a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group; It represents a divalent linking group formed from one or more groups selected from the group consisting of unsubstituted and / or aliphatic groups. The combination of X ³¹ , X ³² , X ³³ and X ³⁴ is not particularly limited, but is more preferably selected from —CO— and —NR ³⁵ —. a, b, c and d are integers of 0 or more, preferably 0 or 1, a + b + c + d is 2 or more, preferably 2 to 8, more preferably 2 to 6, further preferably 2-4. Z ³¹ represents an (a + b + c + d) -valent organic group (excluding a cyclic group). Valence of Z ³¹ is preferably 2 to 8, more preferably 2 to 6, preferably 2 to 4 further 2 or 3 being most preferred. An organic group refers to a group composed of an organic compound.

Moreover, as said general formula (5), Preferably it is a compound represented by the following general formula (5-1).
Formula (5-1): R ³¹¹ -X ³¹¹ -Z ³¹¹ -X ³¹² -R ³¹²

In the general formula (5-1), R ³¹¹ and R ³¹² each represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group, and an aliphatic group is preferable. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable. X ³¹¹ and X ³¹² each independently represent —CONR ³¹³ — or —NR ³¹⁴ CO—, wherein R ³¹³ and R ³¹⁴ represent a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. More preferred are unsubstituted and / or aliphatic groups. Z ³¹¹ is —O—, —S—, —SO—, —SO ₂ —, —CO—, —NR ³¹⁵ — (R ³¹⁵ is a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. Represents an unsubstituted group and / or an aliphatic group, and represents a divalent organic group (excluding a cyclic group) formed from one or more groups selected from an alkylene group and an arylene group. . The combination of Z ³¹¹ is not particularly limited, but is preferably selected from —O—, —S—, —NR ³¹⁵ —, and an alkylene group, more preferably selected from —O—, —S—, and an alkylene group. Most preferably, it is selected from-, -O-, -S- and an alkylene group.

  The general formula (5-1) is preferably a compound represented by the following general formulas (5-2) to (5-4).

In the above general formulas (5-2) to (5-4), R ³²¹ , R ³²² , R ³²³ and R ³²⁴ each represents a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. An aliphatic group is preferred. The aliphatic group may be linear, branched or cyclic, and more preferably cyclic. Examples of the substituent that the aliphatic group and the aromatic group may have include the substituent T described later, but an unsubstituted one is preferable. Z ³²¹ is —O—, —S—, —SO—, —SO ₂ —, —CO—, —NR ³²⁵ — (R ³²⁵ is a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. Represents an unsubstituted group and / or an aliphatic group, and a divalent linking group formed from one or more groups selected from an alkylene group and an arylene group. The combination of Z ³²¹ is not particularly limited, but is preferably selected from —O—, —S—, —NR ³²⁵ —, and an alkylene group, and more preferably selected from —O—, —S—, and an alkylene group. .

Hereinafter, the substituted or unsubstituted aliphatic group will be described.
The aliphatic group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, particularly 6 to 20 carbon atoms. preferable. Specific examples of the aliphatic group include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, t-butyl group, amyl group, isoamyl group, t- Amyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, bicyclooctyl group, adamantyl group, n-decyl group, t-octyl group, dodecyl group, hexadecyl group, octadecyl group, didecyl group, etc. Is mentioned.

Below, said aromatic group is demonstrated.
The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group, and more preferably an aromatic hydrocarbon group. The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, and more preferably 6 to 12 carbon atoms. Specific examples of the aromatic hydrocarbon group include benzene, naphthalene, anthracene, biphenyl, terphenyl, and the like. As the aromatic hydrocarbon group, benzene, naphthalene, and biphenyl are particularly preferable. As the aromatic heterocyclic group, those containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom are preferable. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, Examples thereof include isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, tetrazaindene and the like. As the aromatic heterocyclic group, pyridine, triazine, and quinoline are particularly preferable.

Moreover, the said substituent T is demonstrated in detail below.
Examples of the substituent T include alkyl groups (preferably those having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, and a t-butyl group. , N-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl, cyclohexyl group, etc., alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 2 carbon atoms). For example, a vinyl group, an allyl group, a 2-butenyl group, a 3-pentenyl group, etc.), an alkynyl group (preferably having a carbon number of 2-20, more preferably 2-12, particularly preferably 2-8, For example, propargyl group, 3-pentynyl group, etc.), aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms). For example, a phenyl group, a biphenyl group, a naphthyl group, and the like, an amino group (preferably having a carbon number of 0 to 20, more preferably 0 to 10, particularly preferably 0 to 6, such as an amino group, a methylamino group, and dimethyl). An amino group, a diethylamino group, a dibenzylamino group, etc.), an alkoxy group (preferably having a carbon number of 1-20, more preferably 1-12, particularly preferably 1-8, such as a methoxy group, an ethoxy group, a butoxy group, etc. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms such as a phenyloxy group and a 2-naphthyloxy group), an acyl group (preferably having a carbon number). 1-20, more preferably 1-16, particularly preferably 1-12, such as acetyl, benzoyl, formyl, piva Yl group), an alkoxycarbonyl group (preferably 2-20, more preferably 2-16, particularly preferably 2-12, such as a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably Has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, an acyloxy group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly Preferably they are 2-10, for example, an acetoxy group, a benzoyloxy group, etc., an acylamino group (preferably C2-C20, More preferably, it is 2-16, Most preferably, it is 2-10, for example, an acetylamino group, Benzoylamino group), alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, More preferably, it is 2 to 16, particularly preferably 2 to 12, for example, a methoxycarbonylamino group and the like, and an aryloxycarbonylamino group (preferably having a carbon number of 7 to 20, more preferably 7 to 16, particularly preferably 7 to 12 such as a phenyloxycarbonylamino group, a sulfonylamino group (preferably having a carbon number of 1 to 20, more preferably 1 to 16, particularly preferably 1 to 12, such as a methanesulfonylamino group or a benzenesulfonylamino group). Group), a sulfamoyl group (preferably having a carbon number of 0 to 20, more preferably 0 to 16, particularly preferably 0 to 12, such as a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, a phenylsulfa group. A moyl group), a carbamoyl group (preferably having 1 to 20 carbon atoms, More preferably, it is 1-16, and particularly preferably 1-12. For example, a carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, etc., an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms). 16, particularly preferably 1 to 12, for example, a methylthio group, an ethylthio group, etc.), an arylthio group (preferably having 6 to 20, more preferably 6 to 16, particularly preferably 6 to 12, such as a phenylthio group. Etc.), a sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group. ), A sulfinyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 16, particularly preferably 1 to 12, such as a methanesulfinyl group, a benzenesulfinyl group, etc.), a ureido group (preferably having a carbon number of 1 to 20). More preferably, it is 1-16, Most preferably, it is 1-12, for example, a ureido group, a methylureido group, a phenylureido group etc., a phosphoric acid amide group (preferably C1-C20, more preferably 1-16) , Particularly preferably 1 to 12, such as diethyl phosphoric acid amide and phenyl phosphoric acid amide), a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a cyano group, Sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Rocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom, specifically, for example, an imidazolyl group, a pyridyl group and a quinolyl group. , Furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms). And examples thereof include a trimethylsilyl group and a triphenylsilyl group. These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Preferred examples of the compound represented by the general formula (5) are shown below, but the present invention is not limited to these specific examples.

  It is also preferable to contain at least one compound having a structure represented by the following general formula (9) or (10) as an additive.

一般式（９）および（１０）中、Ｒ⁴¹〜Ｒ⁴⁸は、各々独立に、水素原子；ハロゲン原子
；酸素原子、硫黄原子、窒素原子もしくはケイ素原子を含む連結基を有していてもよい、置換もしくは非置換の炭素原子数１〜３０の炭化水素基；または極性基を表し、Ｒ⁴⁴は全て同一の原子または基であっても、個々異なる原子または基であっても、互いに結合して、炭素環または複素環(これらの炭素環、複素環は単環構造でもよいし、他の環が縮合して多環構造を形成してもよい)を形成してもよい。

In the general formulas (9) and (10), R ^{41 to} R ⁴⁸ may each independently have a linking group containing a hydrogen atom; a halogen atom; an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. Represents a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group, and R ⁴⁴ are all bonded to one another, whether they are the same atom or group, or different atoms or groups. In addition, a carbocycle or a heterocycle (these carbocycles and heterocycles may be monocyclic structures or other rings may be condensed to form a polycyclic structure).

  The general formula (9) is a structural unit obtained from an aromatic vinyl monomer. Specific examples of the aromatic vinyl monomer include styrene; alkyl-substituted styrenes such as α-methylstyrene, β-methylstyrene, and p-methylstyrene; halogen substitution such as 4-chlorostyrene and 4-bromostyrene. Styrenes; hydroxystyrenes such as p-hydroxystyrene, α-methyl-p-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene; vinyl benzyl alcohols; p-methoxystyrene, p- alkoxy-substituted styrenes such as t-butoxystyrene and mt-butoxystyrene; vinylbenzoic acids such as 3-vinylbenzoic acid and 4-vinylbenzoic acid; methyl-4-vinylbenzoate, ethyl-4-vinylbenzoate and the like Vinyl benzoates; 4-vinyl benzyl ester Tate; 4-acetoxystyrene; amidostyrenes such as 2-butylamidostyrene, 4-methylamidostyrene, p-sulfonamidostyrene; 3-aminostyrene, 4-aminostyrene, 2-isopropenylaniline, vinylbenzyldimethylamine Aminostyrenes such as 3-nitrostyrene, nitrostyrenes such as 4-nitrostyrene; cyanostyrenes such as 3-cyanostyrene and 4-cyanostyrene; vinylphenylacetonitrile; arylstyrenes such as phenylstyrene, indenes However, the present invention is not limited to these specific examples. Two or more of these monomers may be used as a copolymerization component. Of these, styrene and α-methylstyrene are preferred because they are easily available industrially and are inexpensive.

  General formula (10) is a structural unit obtained from an acrylate monomer. Examples of the acrylate monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-). , Pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), acrylic acid Nonyl (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2- Hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid (2-methoxyethyl), acrylic acid Phosphoric acid (2-ethoxyethyl) phenyl acrylate, phenyl methacrylate, acrylic acid (2 or 4-chlorophenyl), methacrylic acid (2 or 4-chlorophenyl), acrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), Methacrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), acrylic acid (o or m or p-tolyl), methacrylic acid (o or m or p-tolyl), benzyl acrylate, benzyl methacrylate, phenethyl acrylate, Phenethyl methacrylate, acrylic acid (2-naphthyl), cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid (4-methylcyclohexyl), methacrylic acid (4-methylcyclohexyl), acrylic acid (4-ethylcyclohexyl), methacrylate Examples include luric acid (4-ethylcyclohexyl) and the like, or those obtained by replacing the acrylic acid ester with a methacrylic acid ester, but the present invention is not limited to these specific examples. Two or more of these monomers may be used as a copolymerization component. Of these, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), or those obtained by replacing the acrylate ester with a methacrylate ester are preferred.

  The (co) polymer includes at least one structural unit obtained from an aromatic vinyl monomer represented by the general formula (9) and an acrylate ester monomer represented by the general formula (10). The inclusion is preferred. Further, the other structure constituting the copolymer composition is preferably one having excellent copolymerizability with the monomer, and examples thereof include maleic anhydride, citraconic anhydride, cis-1-cyclohexene-1 , 2-dicarboxylic anhydride, 3-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride, 4-methyl-cis-1-cyclohexene-1,2-dicarboxylic anhydride and the like, acrylonitrile, Nitrile group-containing radical polymerizable monomers such as methacrylonitrile; amide bond-containing radical polymerizable monomers such as acrylamide, methacrylamide, trifluoromethanesulfonylaminoethyl (meth) acrylate; fatty acid vinyls such as vinyl acetate; Chlorine-containing radical polymerizable monomers such as vinyl and vinylidene chloride; 1,3-butadiene; Isoprene, 1,4-dimethyl butadiene and the like can be mentioned conjugated diolefins but the present invention is not limited thereto.

  When the copolymer as described above is used, it is preferable to contain at least 30 mol% of the structural unit represented by the general formula (9) in the copolymer composition. Moreover, it is preferable to contain at least 20 mol% or more of the structural unit represented by the general formula (10). Moreover, it is preferable that the ratio of another copolymerization component is 50 mol% or less.

The weight average molecular weight of the compound having the structure represented by the general formula (9) or (10) is preferably 500 or more and 300,000 or less, and is excellent in compatibility with the binder and transparency of the film after film formation. In order to obtain a film exhibiting good expression of characteristics, it is more preferably 500 or more and 15000 or less, and particularly preferably 500 or more and 5000 or less.
In the present invention, the weight average molecular weight of the compound contained in the cyclic polyolefin film is a value measured by GPC (developing solvent: tetrahydrofuran, polystyrene conversion method).

(Additive synthesis method)
The additives preferably used in the present invention described above can also be synthesized.
For example, the additive of the general formula (1) can be obtained by a condensation reaction of a sulfonyl chloride derivative and an amine derivative. The compound of the general formula (2) can be obtained by oxidation reaction of sulfide or Friedel-Crafts reaction of aromatic compound and sulfonic acid chloride.

(Addition amount of additive)
The amount of the additive represented by the general formulas (1) to (5) preferably used in the present invention described above is preferably 1% by mass or more based on the cyclic polyolefin resin. It is preferable that it is 1-35 mass%, and it is more preferable that it is 20-30 mass%.
If it is in the range of the said addition amount, when the film of this invention is used as a protective film for polarizing plates, it is excellent in polarizing plate bonding suitability, and there is little possibility of peeling after polarizing plate processing.
Moreover, the said additive may be used 1 type or may use 2 or more types. When two or more types are used, the addition amount of two or more types of additives is preferably 1 to 35% by mass, and preferably 20 to 30% by mass, of the total addition amount of the two types. More preferred.

  The compound having the structure represented by the general formula (9) or (10) preferably used in the present invention described above is preferably 1 to 35% by mass of the cyclic polyolefin-based resin. In order to obtain an excellent film exhibiting good optical properties, the content is more preferably 5 to 30% by mass, and particularly preferably 20 to 30% by mass.

  Moreover, the compound which has a structure represented by these general formula (9) or (10) may be used independently, or may mix and use 2 or more types of compounds by arbitrary ratios.

  The total content of the compounds having a structure represented by two or more general formulas (9) or (10) is preferably 1 to 35% by mass of the cyclic polyolefin resin, and is excellent in transparency after film formation. In order to obtain a film exhibiting good expression of optical properties, the content is more preferably 5 to 30% by mass, and particularly preferably 20 to 30% by mass.

(Method of adding additives)
Moreover, these additives may be used independently or may mix and use 2 or more types of additives by arbitrary ratios.
Further, the timing of adding these compounds may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

(Fine particles)
In the present invention, by adding fine particles to the cyclic polyolefin-based resin, the film formation stability and processability of the film can be further improved, and the optical unevenness of the film due to winding crease can be reduced. As fine particles that can be used in the present invention, fine particles of organic or inorganic compounds can be used.

  Inorganic compounds include silicon-containing compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, Preferred are calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate, and more preferred are inorganic compounds and metal oxides containing silicon. That is, in the present invention, a metal oxide or an inorganic silicon compound is preferably used as the fine particles. In the present invention, since the turbidity of the film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the fine particles of zirconium oxide, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  Examples of the organic compound include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, starch and the like, and pulverized and classified products thereof. Alternatively, a polymer compound synthesized by a suspension polymerization method, a polymer compound made spherical by a spray drying method, a dispersion method, or the like can be used.

  The primary average particle diameter of the fine particles is preferably 0.001 μm to 20 μm, more preferably 0.001 μm to 10 μm, and still more preferably 0.002 μm to 1 μm, from the viewpoint of keeping the haze low. Particularly preferably, the thickness is 0.005 μm to 0.5 μm. The measurement of the primary average particle diameter of the fine particles is obtained by the average particle diameter of the particles with a transmission electron microscope. The purchased fine particles are often agglomerated and are preferably dispersed by a known method before use. The secondary particle diameter is preferably 0.2 μm to 1.5 μm by dispersion, and more preferably 0.3 μm to 1 μm. The addition amount of the fine particles is preferably 0.01 parts by mass to 0.3 parts by mass, more preferably 0.05 parts by mass to 0.2 parts by mass with respect to 100 parts by mass of the cyclic polyolefin-based resin, and 0.08 parts by mass to 0.12 parts by mass is most preferred.

When the particles are dispersed, the haze increases and the transparency decreases, so the average particle size is 0.001 μm to 100 It is preferable that it is micrometer, More preferably, it is 0.01 micrometer-10 It is μm, more preferably 0.01 μm to 5 μm.
Further, the content is preferably 0.0001% by mass to 10% by mass in the whole cyclic polyolefin film regardless of the case where the content is dispersed in the form of particles such as spheres and irregular shapes, or in the case of molecular dispersion. More preferably, it is 0.001 mass%-5 mass%, More preferably, it is 0.01 mass%-3 mass%.

  The preferable light transmittance range of the cyclic polyolefin film in the present invention is 88.0% or more, more preferably 89.0% or more, and particularly preferably 90.0% or more. The transmittance was measured at a measurement wavelength of 550 nm using a spectrophotometer (U-3210, Hitachi, Ltd.) at 25 ° C. and 60% RH for a sample of 13 mm × 40 mm.

The method for incorporating the above compound into the film is not particularly limited, but a method of casting a solution containing the cyclic polyolefin resin and the above compound to form a film, and the above compound on the film after casting the cyclic polyolefin resin. Examples thereof include a method of coating the coating liquid containing, a method of casting a multilayer, and the like. In the present invention, the cyclic polyolefin film is produced by one of the following two production methods.
1. A method for producing a cyclic polyolefin film, comprising a step of dissolving or dispersing a cyclic polyolefin resin and at least one compound in a solvent, a step of casting, a step of drying, and a step of winding.
2. A method for producing a cyclic polyolefin film, comprising a step of dissolving a cyclic polyolefin-based resin in a solvent, a step of casting, a step of drying, and a step of winding, wherein at least one of the films after casting A method for producing a cyclic polyolefin film, comprising a step of applying a coating liquid containing at least one compound on the surface.
By manufacturing by either of the above-mentioned two methods, a cyclic polyolefin film suitable as an optical film having excellent flatness and uniformity can be manufactured, which is more preferable.

  In the above method 1, a solution containing a cyclic polyolefin resin and the above compound is cast to form a film. In the case of this method, the compound may be dissolved or dispersed when preparing the cyclic polyolefin resin solution, or the compound solution or dispersion may be added immediately before casting the cyclic polyolefin resin solution. good. In preparing the dispersion, known methods such as a normal stirrer, a soft high-speed stirrer for a homogenizer, a dispersion using a medium such as a ball mill, a paint shaker, and a dyno mill, and an ultrasonic disperser can be used. When the above compound is dispersed in the cyclic polyolefin resin solution, a small amount of a surfactant or polymer usually used as a dispersion aid may be added.

In the above method 2, the “coating liquid” may contain the above compound as a main component. Simply by using a solution or dispersion in which the above compound is dissolved or dispersed in a suitable solvent as a coating solution, the coating solution is formed on the surface of a layer comprising a cyclic polyolefin resin as a main component (that is, a film after casting). May be applied. Moreover, the coating liquid may contain the binder, and the layer containing the said compound may be formed by coating this coating liquid.
The coating solution can be applied to one side or both sides of a layer mainly composed of a cyclic polyolefin resin.

The binder for forming the compound layer is not particularly limited, and may be a lipophilic binder or a hydrophilic binder. As the oleophilic binder, known thermoplastic resins, thermosetting resins, radiation curable resins, reactive resins, and mixtures thereof can be used.
The Tg of the resin is preferably 80 ° C to 400 ° C, more preferably 120 ° C to 350 ° C.
The mass average molecular weight of the resin is preferably 10,000 to 1,000,000, more preferably 10,000 to 500,000. When the above compound is dispersed in the coating solution, the same dispersion method as the above-mentioned method 1 can be used, and a small amount of a surfactant or polymer usually used as a dispersion aid may be added.

Examples of the thermoplastic resin include vinyl chloride / vinyl acetate copolymers, vinyl chloride, copolymers of vinyl acetate and vinyl alcohol, maleic acid and / or acrylic acid, vinyl chloride / vinylidene chloride copolymers, vinyl chloride / Acrylonitrile copolymer, vinyl copolymer such as ethylene / vinyl acetate copolymer, cellulose derivatives such as nitrocellulose, cellulose acetate propionate, cellulose acetate butyrate resin, cyclic polyolefin resin, acrylic resin, polyvinyl acetal resin, Polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene butadiene resin, butadiene resin Rubber-based resins such as Rironitoriru resins, silicone resins, and fluorine resins.
The layer thickness of the layer containing the compound is preferably 0.0001 to 10 μm, more preferably 0.001 to 5 μm, and still more preferably 0.01 to 1 μm.
Further details of the method for producing the cyclic polyolefin film will be described later.

(Other additives)
In the cyclic polyolefin film of the present invention, various additives (for example, deterioration inhibitors, UV inhibitors, peeling accelerators, plasticizers, infrared absorbers, etc.) are added depending on the application in each production process of the film. They can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of an ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration preventing agents are also possible. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the cyclic polyolefin-based resin solution (dope) preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. . Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cyclic polyolefin film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

(Deterioration inhibitor)
In the present invention, known degradation (oxidation) inhibitors such as 2,6-di-t-butyl, 4-methylphenol, 4,4′-thiobis- (6-t-butyl-) are added to the cyclic polyolefin resin solution. 3-methylphenol), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, penta A phenolic or hydroquinone antioxidant such as erythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t It is preferable to add a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite. The antioxidant is added in an amount of 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic polyolefin resin.

(UV absorber)
In the present invention, an ultraviolet absorber can be added to the cyclic polyolefin resin solution from the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal. As an ultraviolet absorber, a wavelength of 370 n
From the viewpoint of excellent liquid crystal display properties with excellent absorbability of ultraviolet rays of m or less, those having less absorption of visible light having a wavelength of 400 nm or more are preferably used. Specific examples of UV absorbers preferably used in the present invention include, for example, hindered phenol compounds, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc. Examples of hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert) -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. Examples of benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6 (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5 -Chlorobenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm by mass in the whole cyclic polyolefin film.

(Plasticizer)
The cyclic polyolefin resin generally has less flexibility than cellulose acetate, and when the film is subjected to bending stress or shear stress, the film is likely to crack. Moreover, when processing as an optical film, a crack is easy to enter into a cutting part and it is easy to generate | occur | produce chips. The generated chips contaminated the optical film and caused optical defects. In order to improve these problems, a plasticizer can be added. Specifically, phthalate ester, trimellitic ester, aliphatic dibasic ester, orthophosphate ester, acetate ester, polyester / epoxidized ester, ricinoleate ester, polyolefin, polyethylene A glycol type compound can be mentioned.

The plasticizer that can be used is preferably selected from compounds having a normal temperature, a normal pressure, a liquid, and a boiling point of 200 ° C. or higher. As specific compound names, the following can be exemplified.
Examples of the aliphatic dibasic acid ester system include dioctyl adipate (230 ° C./760 mmHg), dibutyl adipate (145 ° C./4 mmHg), di-2-ethylhexyl adipate (335 ° C./760 mmHg), dibutyl diglycol adipate (230-240). ° C / 2mmHg), di-2-ethylhexyl azelate (220-245 ° C / 4mmHg), di-2-ethylhexyl sebacate (377 ° C / 760mmHg), etc .; as the phthalate ester system, for example, diethyl phthalate (298 ° C / 760 mmHg), diheptyl phthalate (235 to 245 ° C./10 mm Hg), di-n-octyl phthalate (210 ° C./760 mm Hg), diisodecyl phthalate (420 ° C./760 mm Hg), etc .; Paraffin waxes (average molecular weight 330-600, melting point 45-80 ° C.), liquid paraffins (JIS standard K2231 ISOVG8, VG15, VG32, VG68, VG100, etc.), paraffin pellets (Melting point 56-58 ° C., 58-60 ° C., 60-62 ° C., etc.), chlorinated paraffin, low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene, squalane and the like. it can.

  The added amount of the plasticizer is 0.5 to 40.0 parts by mass, preferably 1.0 to 30.0 parts by mass, more preferably 3.0 to 100 parts by mass of the cyclic polyolefin resin. 20.0 parts by mass. If the added amount of the plasticizer is less than this, the plastic effect is insufficient and the processability is not improved. On the other hand, the plasticizer may be separated and eluted over time for a long time, which is not preferable because optical unevenness and contamination of other parts occur.

Hereinafter, the manufacturing method of the cyclic polyolefin film of this invention is demonstrated in detail.
The film production method of the present invention is produced by a solution casting method. The solution casting method has a step of casting a cyclic polyolefin resin solution containing at least a cyclic polyolefin resin on a support. The following describes a mode for producing a cyclic polyolefin film containing an additive suitable for the present invention. Such a cyclic polyolefin film is preferably produced by one of the following two production methods among the solution casting methods.
1. A method for producing a cyclic polyolefin film, comprising a step of dissolving or dispersing a cyclic polyolefin resin and at least one compound in a solvent, a step of casting, a step of drying, and a step of winding.
2. A method for producing a cyclic polyolefin film, comprising a step of dissolving a cyclic polyolefin-based resin in a solvent, a step of casting, a step of drying, and a step of winding, wherein at least one of the films after casting A method for producing a cyclic polyolefin film, comprising a step of applying a coating liquid containing at least one compound on the surface.
Moreover, it is preferable to extend | stretch after the said casting process.

  The two production methods 1 and 2 are different in the way the compound is incorporated into the cyclic polyolefin film. In the method 1 described above, the compound is dissolved or dispersed in the same layer with respect to the layer having the cyclic polyolefin resin as a main component, whereas in the method 2, the compound is dissolved in the layer having the cyclic polyolefin resin as a main component. It differs in the point which coats the coating liquid containing a compound. Hereinafter, although it explains in full detail for each process from (the process to melt | dissolve, dope preparation)-(the process to wind up after drying), said 1 manufacturing method is melt | dissolved or disperse | distributed in (the process to melt | dissolve, dope preparation). , Except for the addition, is the same as the production method of 2 above.

(Dissolution process, dope preparation)
First, each material component is dissolved in a solvent described later to prepare a cyclic polyolefin resin solution (dope). As for the preparation of the dope, a method by stirring and dissolving at room temperature, a method of cooling and dissolving by stirring at room temperature to swell the cyclic polyolefin resin and the like, cooling from −20 to −100 ° C., and heating again to 20 to 100 ° C. There are a high temperature dissolution method in which the temperature is higher than the boiling point of the main solvent in a closed container, and a method in which the temperature is increased to a critical point of the solvent at a high temperature and pressure. A cyclic polyolefin resin having good solubility is preferably dissolved at room temperature, but a cyclic polyolefin resin having poor solubility is dissolved by heating in a sealed container. It is more efficient to select as low a temperature as possible for those that are not so badly soluble.

In the present invention, the viscosity of the cyclic polyolefin resin solution is preferably in the range of 1 to 500 Pa · s at 25 ° C. More preferably, it is the range of 5-200 Pa.s. The viscosity was measured as follows. 1 mL of the sample solution was measured with a rheometer (CLS 500) using Steel Cone (both manufactured by TA Instruments) having a diameter of 4 cm / 2 °.
Measurement was started after the sample solution was kept warm at the measurement start temperature until the liquid temperature became constant.

  The solvent used in preparing the dope will be described. In the present invention, the solvent that can be used is not particularly limited as long as the object can be achieved as long as the cyclic polyolefin-based resin and the like can be dissolved, cast, and formed into a film. The solvent used in the present invention is, for example, a solvent selected from a chlorinated solvent such as dichloromethane and chloroform, a chain hydrocarbon having 3 to 12 carbon atoms, a cyclic hydrocarbon, an aromatic hydrocarbon, an ester, a ketone, and an ether. preferable. The ester, ketone and ether may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane and decane. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene, xylene and the like. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. The preferable boiling point of the organic solvent is 35 ° C. or more and 150 ° C. or less. The solvent used in the present invention can be used by mixing two or more kinds of solvents in order to adjust solution properties such as drying property and viscosity. Further, as long as the cyclic polyolefin resin is dissolved in the mixed solvent. It is also possible to add a poor solvent.

  A preferred poor solvent can be appropriately selected depending on the type of polymer used. When a chlorinated organic solvent is used as the good solvent, alcohols can be preferably used. The alcohols may preferably be linear, branched or cyclic, and among them, saturated aliphatic hydrocarbons are preferable. The hydroxyl group of the alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. As the alcohol, fluorine-based alcohol is also used. For example, 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like can also be mentioned. Among the poor solvents, monohydric alcohols have a peeling resistance reducing effect and can be preferably used. Particularly preferred alcohols vary depending on the good solvent to be selected, but considering the drying load, alcohols having a boiling point of 120 ° C. or lower are preferred, monohydric alcohols having 1 to 6 carbon atoms are more preferred, and those having 1 to 4 carbon atoms Alcohols can be used particularly preferably. A particularly preferable mixed solvent for preparing a solution obtained by dissolving a cyclic polyolefin resin or the like is dichloromethane as a main solvent, and one or more alcohols selected from methanol, ethanol, propanol, isopropanol or butanol as a poor solvent. It is a combination to do.

The cyclic polyolefin resin solution is characterized in that a high concentration of dope can be obtained by appropriately selecting the solvent to be used, and the cyclic polyolefin resin having high concentration and excellent stability without depending on the means of concentration. A solution is obtained. Furthermore, in order to make it easy to melt | dissolve, after making it melt | dissolve at a low density | concentration, you may concentrate using a concentration means. The concentration method is not particularly limited. For example, the low-concentration solution is guided between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blade rotating in the circumferential direction, and the temperature between the solution and the solution. A method of obtaining a high-concentration solution while evaporating the solvent by giving a difference (for example, Japanese Patent Laid-Open No. 4-259511), blowing a heated low-concentration solution into the container from the nozzle, and until the solution hits the inner wall from the nozzle In which the solvent is flash evaporated and the solvent vapor is withdrawn from the container and the concentrated solution is withdrawn from the bottom of the container (eg, US Pat. No. 2,541,012, US Pat. No. 2,858,229, US Pat. No. 4,414,341, U.S. Pat. No. 4,504,355, etc.).

  Prior to casting, it is preferable to filter off foreign matters such as undissolved matter, dust, and impurities using a suitable filter medium such as a wire mesh or flannel. For the filtration of the cyclic polyolefin resin solution, a filter having an absolute filtration accuracy of 0.1 μm to 100 μm is used, and a filter having an absolute filtration accuracy of 0.5 μm to 25 μm is preferably used. The thickness of the filter is preferably 0.1 μm to 10 mm, more preferably 0.2 mm to 2 mm. In that case, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.3 MPa or less, further 1.0 MPa or less, and particularly preferably 0.6 MPa or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, and fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics and metals are also preferably used.

  As the method and equipment for producing the cyclic polyolefin film of the present invention, the same solution casting film forming method and solution casting film forming apparatus as those conventionally used for producing cellulose triacetate films are used. The dope (cyclic polyolefin resin solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. Both ends of the obtained web are sandwiched between clips, transported with a tenter and dried, then transported with a roll group of a drying device, dried, and wound up to a predetermined length with a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

The prepared cyclic polyolefin resin solution (dope) is preferably cast on an endless metal support, for example, a metal drum or a metal support (band or belt), and the solvent is evaporated to form a film. The dope before casting is preferably adjusted in concentration so that the amount of cyclic polyolefin is 10 to 35 mass%. The surface of the drum or band is preferably finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 30 ° C. or less, and particularly preferably at a metal support temperature of −50 to 20 ° C.
Further, JP-A Nos. 2000-301555, 2000-301558, 7-032391, JP-A-3-193316, JP-A-5-086212, JP-A-62-237113, JP-A-2-276607. The cellulose acylate film-forming techniques described in JP-A-55-014201, JP-A-2-111511 and JP-A-2-208650 can be applied in the present invention.

(Casting, multistory casting)
The cyclic polyolefin resin solution may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of cyclic polyolefin liquids of two or more layers may be cast.
When casting a plurality of cyclic polyolefin resin solutions, a film is produced while casting and laminating a solution containing cyclic polyolefin from a plurality of casting openings provided at intervals in the traveling direction of the metal support. For example, JP-A-61-158414, JP-A-1-
The methods described in JP-A Nos. 122419 and 11-198285 can be applied.
Further, it may be formed into a film by casting a cyclic polyolefin resin solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245. The methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933 can be used. In addition, a flow of a high-viscosity cyclic polyolefin resin solution described in JP-A-56-162617 is wrapped with a low-viscosity cyclic polyolefin resin solution, and the high-low viscosity cyclic polyolefin resin solution is simultaneously extruded. A polyolefin film casting method may be used. Furthermore, it is also a preferred embodiment that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner solution. Alternatively, the film is formed by peeling the film formed on the metal support using the first casting port and performing the second casting on the side in contact with the metal support surface using the two casting ports. For example, it is a method described in Japanese Patent Publication No. 44-20235. The cyclic polyolefin resin solution to be cast may be the same solution or different cyclic polyolefin resin solutions and is not particularly limited. In order to give a function to a plurality of cyclic polyolefin layers, a cyclic polyolefin resin solution corresponding to the function may be extruded from each casting port. Further, the cyclic polyolefin resin solution may be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a matting agent layer, a UV absorbing layer, a polarizing layer). sell.

In the case of a single-layer liquid, it is necessary to extrude a high-concentration and high-viscosity cyclic polyolefin resin solution in order to obtain the required film thickness. This is likely to cause a problem due to a failure or flatness. As a solution to this, by casting a plurality of cyclic polyolefin resin solutions from a casting port, a highly viscous solution can be extruded onto a metal support at the same time. In addition, it is possible to reduce the drying load by using a thick cyclic polyolefin resin solution, and to increase the production speed of the film.
In the case of co-casting, the inner and outer thicknesses are not particularly limited, but preferably the outer side is preferably 1 to 50% of the total film thickness, and more preferably 2 to 30%. Here, in the case of co-casting with three or more layers, the total thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, a cyclic polyolefin film having a laminated structure can be produced by co-casting the above-described cyclic polyolefin resin solutions having different additive concentrations. For example, a cyclic polyolefin film having a structure of skin layer / core layer / skin layer can be produced. The deterioration inhibitor and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. It is also possible to change the type of deterioration inhibitor and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer may contain a low volatility deterioration inhibitor and / or an ultraviolet absorber so that the core layer is plastic. It is also possible to add an excellent plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Moreover, it is also a preferable aspect to contain a peeling accelerator only in the skin layer on the metal support side. It is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. Further, the viscosity of the solution containing the cyclic polyolefin at the time of casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. It may be smaller than the viscosity.

(Casting)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Alternatively, there is a method using a reverse roll coater that adjusts with a reverse rotating roll, and a method using a pressure die is preferable. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods listed here, it can be carried out by various methods of casting a cellulose triacetate solution known in the art, and by setting each condition in consideration of differences in the boiling point of the solvent used, etc. The same effects as described in the above publication can be obtained. The endlessly running metal support used for producing the cyclic polyolefin film of the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt (which may be called a band) whose surface is mirror-finished by surface polishing. Good) is used. The pressure die used for the production of the cyclic polyolefin film of the present invention may be one or two or more installed above the metal support. Preferably 1 or 2 groups. When two or more units are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps. The temperature of the cyclic polyolefin resin solution used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the processes may be the same, or may be different at various points in the process. If they are different, the temperature may be a desired temperature just before casting.

(Dry)
The drying of the dope on the metal support involved in the production of the cyclic polyolefin film is generally performed by applying hot air from the surface side of the metal support (for example, drum or band), that is, from the surface of the web on the metal support, A method of applying hot air from the back side of the drum or band, a liquid whose temperature is controlled by contacting the liquid from the back side opposite to the dope casting surface of the band or drum, and heating the drum or band by heat transfer to control the surface temperature Although there is a heat transfer method, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 degrees lower than the boiling point of the lowest boiling solvent used. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.

(Peeling)
When peeling off a dry-dried film-like material (the film-like material does not contain much residual solvent at this time, it is also referred to as film below) from the metal support, if the peel resistance (peeling load) is large, The film is irregularly stretched in the film direction, resulting in uneven optical anisotropy. In particular, when the peeling load is large, a portion stretched stepwise in the film forming direction and a portion unstretched are alternately generated, resulting in a distribution in retardation. When loaded in a liquid crystal display device, the line or strip becomes uneven. In order not to cause such a problem, it is preferable to set the peeling load of the film to 0.25 N or less per 1 cm of the film peeling width. The peeling load is more preferably 0.2 N / cm or less, further preferably 0.15 N or less, and particularly preferably 0.10 N or less. When the peeling load is 0.2 N / cm or less, even in a liquid crystal display device in which unevenness is likely to appear, no unevenness due to peeling is observed, which is particularly preferable. As a method for reducing the peeling load, there are a method of adding a release agent as described above and a method of selecting a solvent composition to be used.
The peel load is measured as follows. The dope is dropped on a metal plate having the same material and surface roughness as the metal support of the film forming apparatus, spread to a uniform thickness using a doctor blade, and dried. Cut the film with a cutter knife with a uniform width, peel off the tip of the film by hand and pinch it with a clip connected to the strain gauge, and measure the load change while pulling up the strain gauge in an oblique 45 degree direction. The volatile content in the peeled film is also measured. The same measurement is performed several times by changing the drying time, and the peeling load at the same time as the residual volatile content at the peeling in the actual film forming process is determined. As the peeling speed increases, the peeling load tends to increase, and it is preferable to measure at a peeling speed close to the actual peeling speed.
A preferable residual volatile content at the time of peeling is 5% by mass to 60% by mass. 10 mass%-50 mass% are still more preferable, and 20 mass%-40 mass% are especially preferable. Peeling with a high volatile content is preferable because the drying rate can be increased and the productivity is improved. On the other hand, when the volatile content is high, the strength and elasticity of the film are small, and the film is cut or stretched against the peeling force. Further, the self-holding power after peeling is poor, and deformation, wrinkles and nicks are likely to occur. It also causes distribution in retardation.

(Extension process)
When the cyclic polyolefin film of the present invention is stretched, it is preferably carried out in a state where the solvent still remains in the film immediately after peeling. The purpose of stretching is (1) to obtain a film having excellent flatness without wrinkles and deformation, and (2) to increase the in-plane retardation of the film. When stretching is performed for the purpose of (1), stretching is performed at a relatively high temperature, and stretching is performed at a low magnification from 1% to 10% at most. A stretch of 2% to 5% is particularly preferred. When stretching for the purposes of both (1) and (2), or only for the purpose of (2), stretching is performed at a relatively low temperature and a stretching ratio of 5% to 150%.

  The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. The birefringence of the optical compensation film for a VA liquid crystal cell or OCB liquid crystal cell is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction.

(After drying)
Next, the stretched film is dried by using a drying apparatus that alternately conveys the film through rolls arranged in a staggered manner. As a drying means, hot air is generally blown on both sides of the film, but there is also a means of heating by applying microwaves instead of the wind. Drying too rapidly tends to impair the flatness of the finished film. Drying at a high temperature is preferably performed from about 8% by mass or less of the residual solvent. Throughout, the temperature in the normal heating region is preferably 40 to 250 ° C, more preferably 70 to 180 ° C, and further preferably 100 to 140 ° C. If the temperature is too high, the film will stretch between the rolls, or wrinkles will occur at the contact area with the roll, causing unevenness, and if the temperature is too low, drying will take time and productivity will deteriorate.
The preferred time for post-drying is 3 to 50 minutes, more preferably 9 to 30 minutes.

In the post-drying step of the present invention, the conveying tension of the cyclic olefin film during drying is preferably 10 to 50 N / film width 1 m, more preferably 15 to 45 N / film width 1 m, and 20 to 40 N / film width 1 m. Most preferably, it is conveyed by If the conveying tension is too high, the orientation in the TD direction (conveying direction, direction perpendicular to MD) expressed by stretching of the film is relaxed, and Re is reduced or uneven stripes occur. On the other hand, if the tension is too low, a scratch is generated at the contact portion with the roll, and the surface condition is deteriorated.
Further, Re fluctuations, streaks, and scratches are greatly affected by the elastic modulus of the film-like material at the temperature in the heating region, and the elastic modulus of the film-like material is preferably 300 to 3000 MPa, and preferably 500 to 2800 MPa. Is more preferable, and is most preferably 1000 to 2500 MPa. The film-like product in the post-drying has a small amount of residual solvent and is close to a completed cyclic olefin film. Therefore, the elastic modulus is almost the same as that of the cyclic olefin film.

Furthermore, when the elastic modulus of the film-like material at the temperature in the heating region of the present invention is E (MPa) and the film thickness is h (μm), E × h ³ is 1.0 × 10 ⁷ or more and 3.0 ×. is preferably 10 ⁹ or less, more preferably 6.0 × 10 ⁷ or more 1.0 × 10 ⁹ or less. By controlling E × h ³ in this way, the retardation change can be suppressed to a low level.

When the in-plane retardation before post-drying of the cyclic olefin film is (before Re heat treatment) and the in-plane retardation after post-drying is (after Re heat treatment), (after Re heat treatment) / (before Re heat treatment) is 0. It is preferably from .75 to 1.0, and more preferably from 0.85 to 1.0.

  In the roll drying, when the aspect ratio of the pass roll span and the film width is X, 0.9 ≦ X ≦ 1.6, preferably 1 ≦ X ≦ 1.6, and more preferably 1.2 ≦ X ≦. The range is 1.6. If the aspect ratio is too small, the film extends between the rolls. Here, the span of a pass roll refers to the distance between the central axis of a pass roll and the central axis of the next pass roll. Two or more pass rolls are enough, but when there are three or more pass rolls, the shortest distance between the pass rolls is taken as the pass roll span.

(Winding process)
Moreover, after drying this at the time of roll drying, both ends are trimmed, and after embossing (knurling is imparted), it is wound up. The residual solvent in the film thus dried is preferably 0% to 5%, more preferably 0% to 3%, still more preferably 0% to 2%, particularly preferably 0% to 1%. . Further, after drying in the present invention, both ends are trimmed and wound up. A preferable width is 0.5 m to 5 m, more preferably 0.7 m to 3 m, and still more preferably 1 m to 2 m. The preferred winding length is 300 m to 30000 m, more preferably 500 m to 10000 m, and still more preferably 1000 m to 7000 m.

The thickness of the finished (after drying) cyclic polyolefin film of the present invention varies depending on the purpose of use, but is usually in the range of 20 to 500 μm, preferably in the range of 30 to 100 μm, particularly for liquid crystal display devices, 35 to 100 μm. It is preferable that
The thickness of the film may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like. The width of the cyclic polyolefin film obtained as described above is preferably 0.5 m to 3 m, more preferably 0.6 m to 2.5 m, and still more preferably 0.8 m to 2.2 m. If the width of the film is 0.5 m or more, the productivity is not reduced, and if it is 3 m or less, the web handling property is not deteriorated or the optical uniformity of the film is not reduced. This is preferable because undesirable phenomena such as streaks do not occur. The length is preferably 100 m to 10000 m per roll, more preferably 500 m to 7000 m, and still more preferably 1000 m to 6000 m. If the film length is 100 m or more, there is no reduction in productivity due to an increase in the frequency of roll exchange, and if it is 10000 m or less, the web handling property is not deteriorated, and the optical uniformity of the film is further reduced. Is preferable because no undesirable phenomenon such as twisting or streaking occurs in the film. When winding, knurling is preferably applied to at least one end, the width is 3 mm to 50 mm, more preferably 5 m to 30 mm, and the height is 0.5 to 500 μm, more preferably 1 to 200 μm. This may be a single push or a double push. The variation in the Re value over the entire width is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation of the Rth value is preferably ± 10 nm, and more preferably ± 5 nm. Further, it is preferable that the variation in the Re value and the Rth value in the length direction is also within the range of the variation in the width direction.

(Optical characteristics of cyclic polyolefin film)
Other preferred optical properties of the cyclic polyolefin film of the present invention vary depending on the application of the film. It describes in each item mentioned later about the case of a protective film use for polarizing plates, and the case of an optical compensation film use.

The cyclic polyolefin film of the present invention achieves desired optical characteristics by appropriately adjusting the process conditions such as the structure of cyclic polyolefin resin used, the type and amount of additives, stretch ratio, residual volatile content at the time of peeling, etc. can do.
In this specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth (λ) is Re (λ) with the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis) (in the absence of the slow axis, any direction in the film plane) Is measured at a total of 6 points by entering light of wavelength λ nm from the inclined direction in 10 degree steps from the normal direction to 50 degrees on one side with respect to the film normal direction of KOBRA 21ADH is calculated based on the retardation value, the assumed average refractive index, and the input film thickness value. The retardation value is measured from any two directions using the slow axis as the tilt axis (rotary axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotational axis), and the value Rth can also be calculated from the following formulas (1) and (2) based on the assumed average refractive index and the input film thickness value. Here, as the assumed value of the average refractive index, 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). The KOBRA 21ADH calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

  Here, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.

Rth = ((nx + ny) / 2−nz) × d −−− Formula (2)
At this time, an average refractive index n is required as a parameter, and a value measured by an Abbe refractometer (“Abbe Refractometer 2-T” manufactured by Atago Co., Ltd.) was used.
In the present invention, unless otherwise specified, the retardation is a value when λ = 590 nm.

  Next, a polarizing plate having the above-described cyclic polyolefin film of the present invention, a protective film for a polarizing plate and an optical compensation film, and a polarizing plate having the protective film for a polarizing plate will be described.

(Retardation film-optical compensation film)
When a cyclic polyolefin film is used as a retardation film, the range of Re and Rth varies depending on the type of retardation film, and there are various needs. It is preferably used as an optical compensation film. The optical compensation film of the present invention may be the cyclic polyolefin film of the present invention itself or may have other constituent layers described below. Moreover, it is desirable to contain a substituent having a large polarizability at an appropriate ratio in the molecule.

(Protective film for polarizing plate)
When the cyclic polyolefin film of the present invention is used as a protective film for a polarizing plate, the in-plane retardation (Re) is preferably 5 nm or less, and more preferably 3 nm or less. The thickness direction retardation (Rth) is preferably 50 nm or less, more preferably 35 nm or less, and particularly preferably 10 nm or less.
The protective film for polarizing plate of the present invention may be the cyclic polyolefin film itself of the present invention or may have other constituent layers described later.

(Polarizer)
The polarizing plate usually has a polarizer and two transparent protective films disposed on both sides thereof. And the polarizing plate of this invention uses the protective film for polarizing plates of this invention as both or one protective film. When the protective film for polarizing plates of the present invention is used only on one side, a normal cellulose acetate film or the like may be used for the other protective film. Examples of the polarizer include an iodine polarizer, a dye polarizer using a dichroic dye, and a polyene polarizer. The iodine-based polarizer and the dye-based polarizer are generally produced using a polyvinyl alcohol (PVA) film. 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. Can do.

  When the cyclic polyolefin film of the present invention is used as a protective film for a polarizing plate and a retardation film, the film is subjected to a surface treatment as described below, and then the film-treated surface and a polarizer are bonded together using an adhesive. Is preferred. The polarizing plate is composed of a polarizer and a protective film that protects both surfaces of the polarizer, and is further constructed by laminating a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

The method of bonding the polarizing plate protective film of the present invention to the polarizer is preferably bonded so that the transmission axis of the polarizer matches the slow axis of the polarizing plate protective film of the present invention. In addition, when the polarizing plate produced under polarizing plate crossed Nicols was evaluated, the orthogonal accuracy between the slow axis of the protective film for polarizing plate of the present invention and the absorption axis of the polarizer (axis orthogonal to the transmission axis) is It was found that when the angle was larger than 1 °, the polarization degree performance under the polarizing plate crossed Nicols was reduced and light leakage occurred. In this case, when combined with a liquid crystal cell, sufficient black level and contrast cannot be obtained. Therefore, the deviation between the direction of the main refractive index nx of the protective film for a polarizing plate of the present invention and the direction of the transmission axis of the polarizing plate is preferably within 1 °, preferably within 0.5 °.
UV3100PC (manufactured by Shimadzu Corporation) can be used to measure the single plate transmittance TT, parallel transmittance PT, and orthogonal transmittance CT of the polarizing plate. In the measurement, measurement is performed in the range of 380 nm to 780 nm, and the average value of 10 measurements can be used for both single plate, parallel and orthogonal transmittance.

The polarizing plate durability test can be performed as follows in two types of forms in which (1) only the polarizing plate and (2) the polarizing plate are attached to glass via an adhesive. For the measurement of only the polarizing plate, two orthogonal and the same ones are prepared and measured so that the polarizing plate protective film is sandwiched between the two polarizers. Two samples (approx. 5 cm × 5 cm) are prepared by attaching a polarizing plate on glass so that the protective film for polarizing plate is on the glass side. In single-plate transmittance measurement, the sample is set with the film side facing the light source. Each of the two samples is measured, and the average value is taken as the transmittance of the single plate. The preferable range of polarization performance is 40.5 ≦ TT ≦ 45, 32 ≦ PT ≦ 39.5, and CT ≦ 1.5 in the order of single plate transmittance TT, parallel transmittance PT, and orthogonal transmittance CT, respectively. More preferable ranges are 41.0 ≦ TT ≦ 44.5, 34 ≦ PT ≦ 39.0, and CT ≦ 1.3.
In the polarizing plate durability test, it is preferable that the amount of change before and after the test is small. For example, with respect to the degree of polarization of a polarizing plate, two polarizing plates are placed in crossed Nicols at 60 ° C. and 90% RH, and the light transmittance after 500 hours has passed compared to the transmittance before the test. Can evaluate sex.
Rate of change in transmittance, that is, {(light transmittance at crossed Nicols after polarizing plate durability test) − (light transmittance at crossed Nicols before polarizing plate durability test)} / (before polarizing plate durability test) The light transmittance at the time of crossed Nicols) × 100 (%) is preferably as small as possible, and is preferably 5% or less.

(Surface treatment of cyclic polyolefin film)
The protective film for polarizing plate of the present invention is preferably subjected to a surface treatment on the surface of the cyclic polyolefin film in order to improve the adhesion with the polarizer. As for the surface treatment, any method may be used as long as the adhesiveness can be improved. Preferred examples of the surface treatment include glow discharge treatment, ultraviolet irradiation treatment, corona treatment and flame treatment. The glow discharge treatment here refers to so-called low temperature plasma that occurs under low pressure gas. In the present invention, plasma treatment under atmospheric pressure is also preferable. The details of the glow discharge treatment are described in US Pat. No. 3,462,335, US Pat. No. 3,761,299, US Pat. No. 4,072,769, and British Patent No. 891469. A method described in Japanese Patent Publication No. 59-556430 is also used in which the gas composition generated in the vessel is made only when the polyester support itself undergoes a discharge treatment after the discharge starts. In addition, the method described in Japanese Patent Publication No. 60-16614, in which the discharge temperature is set to 80 ° C. or more and 180 ° C. or less when the vacuum glow discharge treatment is performed, is also applicable.

The degree of vacuum during the glow discharge treatment is preferably 0.5 Pa to 3000 Pa, more preferably 2 Pa to 300 Pa. The voltage is preferably between 500V and 5000V, more preferably between 500V and 3000V. The discharge frequency to be used is from direct current to several thousand MHz, more preferably 50 Hz to 20 MHz, and further preferably 1 KHz to 1 MHz. The discharge treatment intensity is preferably 0.01 KV · A · min / m ^{2 to 5} KV · A · min / m ² , more preferably 0.15 KV · A · min / m ^{2 to 1} KV · A · min / m ² . is there.

In the present invention, it is also preferable to perform an ultraviolet irradiation method as the surface treatment. For example, it can be carried out by the processing methods described in JP-B 43-2603, JP-B 43-2604, and JP-B 45-3828. The mercury lamp is a high-pressure mercury lamp made of a quartz tube and preferably has an ultraviolet wavelength of 180 to 380 nm. As for the method of ultraviolet irradiation, a high pressure mercury lamp with a dominant wavelength of 365 nm can be used as long as the surface temperature of the protective film rises to around 150 ° C. in terms of the performance of the support. When low-temperature treatment is required, a low-pressure mercury lamp having a dominant wavelength of 254 nm is preferable. It is also possible to use an ozone-less high-pressure mercury lamp and a low-pressure mercury lamp. Regarding the amount of processed light, the greater the amount of processed light, the better the adhesive strength between the thermoplastic saturated alicyclic structure-containing polymer resin film and the polarizer, but there is a problem that the film becomes colored and becomes brittle as the amount of light increases. appear. Accordingly, a high pressure mercury lamp for a 365nm main wavelength, irradiation dose 20mJ / cm ² ~10000mJ / cm ² C., more preferably ^{50mJ / cm 2 ~2000mJ / cm 2} . In the case of low-pressure mercury lamp for a 254nm main wavelength, the irradiation light intensity 100mJ / cm ² ~10000mJ / cm ² C., more preferably ^{300mJ / cm 2 ~1500mJ / cm 2} .

Furthermore, in the present invention, it is also preferable to perform a corona discharge treatment as the surface treatment. For example, it can be carried out by the processing methods described in JP-B-39-12838, JP-A-47-19824, JP-A-48-28067, and JP-A-52-42114. As the corona discharge treatment apparatus, a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, a VETAPHON type treatment machine, or the like can be used. The treatment can be performed at normal pressure in air. The discharge frequency during the treatment is 5 KV to 40 KV, more preferably 10 KV to 30 KV, and the waveform is preferably an AC sine wave. The gap transparent lance between the electrode and the dielectric roll is 0.1 mm to 10 mm, more preferably 1.0 mm to 2.0 mm. The discharge is processed above a dielectric support roller provided in the discharge zone, and the treatment amount is 0.34 KV · A · min / m ^{2 to} 0.4 KV · A · min / m ² , more preferably 0.344 KV. A · min / m ^{2 to} 0.38 KV · A · min / m ² .

In the present invention, it is also preferable to perform a flame treatment as the surface treatment. The gas used may be natural gas, liquefied propane gas, or city gas, but the mixing ratio with air is important. This is because the effect of surface treatment by flame treatment is considered to be brought about by plasma containing active oxygen, and the point is how much plasma activity (temperature) and oxygen are important properties of flame. is there. The governing factor of this point is the gas / oxygen ratio. When the reaction is carried out without excess or deficiency, the energy density is the highest and the plasma activity is increased. Specifically, the preferable mixing ratio of natural gas / air is 1/6 to 1/10, preferably 1/7 to 1/9 in volume ratio. In the case of liquefied propane gas / air, 1/14 to 1/22, preferably 1/16 to 1/19, and in the case of city gas / air, 1/2 to 1/8, preferably 1/3 to 1. / 7. The flame treatment amount is 1 Kcal / m ^{2 to} 50 Kcal / m ² , more preferably 3 Kcal / m ^{2 to 20} Kcal / m ² . The distance between the tip of the burner inner flame and the film is 3 cm to 7 cm, more preferably 4 cm to 6 cm. The burner nozzle shapes are: Flynburner (USA) ribbon type, Wise (USA) multi-hole type, Aerogen (UK) ribbon type, Kasuga Electric (Japan) staggered multi-hole type, Koike Oxygen ( Japan) is preferred. The backup roll that supports the film for the flame treatment is a hollow roll, and is preferably cooled at a constant temperature of 20 ° C. to 50 ° C. by cooling with cooling water.

  As for the degree of surface treatment, the preferred range varies depending on the type of surface treatment and the type of cyclic polyolefin, but as a result of the surface treatment, the contact angle of the surface of the protective film subjected to the surface treatment with pure water is less than 50 ° It is preferable that The contact angle is more preferably 25 ° or more and less than 45 °. When the contact angle with the pure water on the surface of the protective film is in the above range, the adhesive strength between the protective film and the polarizing film becomes good.

(adhesive)
When laminating a polarizer made of a polyvinyl alcohol film and a surface-treated cyclic polyolefin film as a protective film for a polarizing plate, an adhesive containing a water-soluble polymer is preferably used. Water-soluble polymers preferably used for the adhesive include N-vinylpyrrolidone, acrylic acid, methacrylic acid, maleic acid, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, vinyl alcohol, methyl vinyl ether, vinyl acetate. , Acrylamide, methacrylamide, diacetone acrylamide, vinyl imidazole and other homopolymers or copolymers having ethylenically unsaturated monomers as constituents, polyoxyethylene, polyoxypropylene, poly-2-methyloxazoline, methylcellulose, hydroxy Examples include ethyl cellulose, hydroxypropyl cellulose, gelatin, and the like. Of these, PVA and gelatin are preferred in the present invention.

  The preferable PVA characteristics when PVA is used for the adhesive are the same as the preferable characteristics of the PVA used for the polarizer. In the present invention, it is preferable to use a crosslinking agent in combination. Examples of the cross-linking agent preferably used in combination with PVA as an adhesive include boric acid, polyvalent aldehyde, polyfunctional isocyanate compound, polyfunctional epoxy compound, and the like, but boric acid is particularly preferred in the present invention. When gelatin is used for the adhesive, so-called lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, gelatin derivatives and modified gelatin can be used. Of these gelatins, lime-processed gelatin and acid-processed gelatin are preferably used. When gelatin is used for the adhesive, the crosslinking agent preferably used in combination is an active halogen compound (2,4-dichloro-6-hydroxy-1,3,5-triazine and its sodium salt) and an active vinyl compound ( 1,3-bisvinylsulfonyl-2-propanol, 1,2-bisvinylsulfonylacetamido) ethane, bis (vinylsulfonylmethyl) ether or vinyl polymers having a vinylsulfonyl group in the side chain), N-carbamoylpyridinium salts ((1-morpholinocarbonyl-3-pyridinio) methanesulfonate, etc.) and haloamidinium salts (1- (1-chloro-1-pyridinomethylene) pyrrolidinium 2-naphthalenesulfonate, etc.). In the present invention, an active halogen compound and an active vinyl compound are particularly preferably used.

  When the above-mentioned crosslinking agent is used in combination, the preferred addition amount of the crosslinking agent is 0.1 parts by mass or more and less than 40 parts by mass with respect to 100 parts by mass of the water-soluble polymer in the adhesive. 5 parts by mass or more and less than 30 parts by mass. It is preferable to apply an adhesive to at least one surface of the protective film or the polarizer to form an adhesive layer, and to bond the adhesive film. Is preferably bonded to the surface of the polarizer. The thickness of the adhesive layer is preferably 0.01 μm to 5 μm, particularly preferably 0.05 μm to 3 μm after drying.

(Antireflection layer)
It is preferable to provide a functional layer such as an antireflection layer on the transparent protective film disposed on the opposite side of the polarizing plate from the liquid crystal cell. In particular, in the present invention, at least a light scattering layer and a low refractive index layer are laminated in this order on the transparent protective film, or a medium refractive index layer, a high refractive index layer, and a low refractive index layer are formed on the transparent protective film. An antireflection layer laminated in order is preferably used. That is, it is preferable to use a transparent protective film as the transparent support on which the antireflection layer is laminated. Preferred examples thereof are described below.

  A preferred example of an antireflection layer in which a light scattering layer and a low refractive index layer are provided on a transparent protective film will be described. It is preferable that mat particles are dispersed in the light scattering layer. The light scattering layer may have both antiglare properties and hard coat properties, and may be a single layer or may be composed of a plurality of layers, for example, 2 to 4 layers.

The antireflection layer has an uneven surface shape with a center line average roughness Ra of 0.08 to 0.40 μm, a 10-point average roughness Rz of 10 times or less of Ra, an average mountain valley distance Sm of 1 to 100 μm, and an uneven depth. Designed so that the standard deviation of the height of the convex part from the part is 0.5 μm or less, the standard deviation of the average mountain valley distance Sm with respect to the center line is 20 μm or less, and the surface with the inclination angle of 0 to 5 degrees is 10% or more. By doing so, sufficient anti-glare properties and a visually uniform matte feeling are achieved, which is preferable.
Further, the ratio of the minimum value and the maximum value of the reflectance within the range of a ^* value −2 to 2, b ^* value −3 to 3, and 380 nm to 780 nm under the light source C is 0.5. By being -0.99, the color of reflected light becomes neutral, which is preferable. Moreover, it is preferable that the b ^* value of the transmitted light under the C light source is 0 to 3 because the yellow color of white display when applied to a display device is reduced.
In addition, when a 120 μm × 40 μm grid is inserted between the surface light source and the antireflection layer and the luminance distribution is measured on the film, the standard deviation of the luminance distribution is 20 or less. Glare when applying a film is reduced, which is preferable.

  The optical properties of the antireflection layer are such that the specular reflectance is 2.5% or less, the transmittance is 90% or more, and the 60 ° glossiness is 70% or less, so that reflection of external light can be suppressed and visibility is improved. Therefore, it is preferable. In particular, the specular reflectance is more preferably 1% or less, and most preferably 0.5% or less. Haze 20% to 50%, internal haze / total haze value (ratio) is 0.3 to 1, haze value after formation of low refractive index layer from haze value up to light scattering layer is within 15%, comb width Prevents glare on a high-definition LCD panel by setting the transmitted image sharpness at 0.5 mm to 20% to 50% and the transmittance ratio of the vertical transmitted light / at a 2 degree tilt from the vertical to 1.5 to 5.0. Reduction of blurring of characters and the like is achieved, which is preferable.

(Low refractive index layer)
The refractive index of the low refractive index layer of the antireflection layer is preferably 1.20 to 1.49, more preferably 1.30 to 1.44. Furthermore, the low refractive index layer preferably satisfies the following mathematical formula from the viewpoint of reducing the reflectance.
(M / 4) λ × 0.7 <n1d1 <(m / 4) λ × 1.3
In the formula, m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 nm to 550 nm.

The material for forming the low refractive index layer will be described below.
The low refractive index layer preferably contains a fluorine-containing polymer as a low refractive index binder. The fluorine polymer is preferably a fluorine-containing polymer that is crosslinked by heat or ionizing radiation with a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 ° to 120 °, and a sliding angle of pure water of 70 ° or less. When the antireflection layer is attached to an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo, preferably 500 gf or less, more preferably 300 gf or less, and more preferably 100 gf or less. Most preferred. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch, preferably 0.3 GPa or more, more preferably 0.5 GPa or more.

  Examples of the fluorine-containing polymer used in the low refractive index layer include hydrolysis and dehydration condensate of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). And a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components.

  Specific examples of the fluorine-containing monomer include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2, 2-dimethyl-1, 3-dioxole, etc. ), A part of (meth) acrylic acid or a fully fluorinated alkyl ester derivative (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) or M-2020 (manufactured by Daikin)), a complete or partially fluorinated vinyl ether, and the like. Perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

As structural units for imparting crosslinking reactivity, structural units obtained by polymerization of monomers having a self-crosslinkable functional group in the molecule in advance such as glycidyl (meth) acrylate and glycidyl vinyl ether, carboxyl groups, hydroxy groups, amino groups Obtained by polymerization of a monomer having a sulfo group or the like (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) And a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into these structural units by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group) And the like.

  In addition to the above-mentioned fluorine-containing monomer units and structural units for imparting crosslinking reactivity, monomers not containing fluorine atoms can be copolymerized as appropriate from the viewpoints of solubility in solvents and film transparency. There are no particular limitations on the monomer units that can be used in combination, such as olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), Methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether) , Cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tert-butylacrylamide, N-cyclohexyl acetate) Ruamido etc.), methacrylamides, and acrylonitrile derivatives. As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the above polymer.

(Light scattering layer)
The light scattering layer is formed for the purpose of contributing to the film light diffusibility due to surface scattering and / or internal scattering, and hard coat properties for improving the scratch resistance of the film. Therefore, it is formed to contain a binder for imparting hard coat properties, matte particles for imparting light diffusibility, and inorganic fillers for increasing the refractive index, preventing cross-linking shrinkage, and increasing the strength as necessary. The The thickness of the light scattering layer is preferably 1 μm to 10 μm, more preferably 1.2 μm to 6 μm, from the viewpoint of imparting hard coat properties and curling generation and suppression of deterioration of brittleness.

  The binder of the scattering layer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure. As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable. In order to make the binder polymer have a high refractive index, the monomer structure contains an aromatic ring, at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms. You can also choose.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1, 2, 3- Rhohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), modified ethylene oxide, vinylbenzene and derivatives thereof (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1, 4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4'-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles, and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and then ionizing radiation or heat is applied. The antireflection layer can be formed by curing by the polymerization reaction. As these photo radical initiators, known ones can be used.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and then subjected to a polymerization reaction by ionizing radiation or heat. Curing can form an antireflection layer.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

For the purpose of imparting antiglare properties, the light scattering layer contains matte particles having an average particle size of 1 μm to 10 μm, preferably 1.5 μm to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting antiglare properties. It is preferred that
As specific examples of the mat particles, inorganic particles such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, cross-linked acrylic particles, polystyrene particles, cross-linked styrene particles, melamine resin particles, and benzoguanamine resin particles are preferable. Can be mentioned. Of these, crosslinked styrene particles, crosslinked acrylic particles, crosslinked acrylic styrene particles, and silica particles are preferable. The shape of the mat particles can be either spherical or irregular.

Two or more kinds of mat particles having different particle diameters may be used in combination. It is possible to impart anti-glare properties with mat particles having a larger particle size and to impart other optical characteristics with mat particles having a smaller particle size.

  Furthermore, the particle size distribution of the mat particles is most preferably monodisperse, and the particle sizes of the particles are preferably closer to each other. For example, when a particle having a particle size of 20% or more than the average particle size is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less, more preferably 0.1% of the total number of particles. Or less, more preferably 0.01% or less. Matt particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and fine particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The mat particles are preferably matte particle amount of the formed light-scattering layer ^{10mg / m 2 ~1000mg / m 2} , more preferably contained in the light scattering layer so as to 100mg / m ² ~700mg / m ² The The particle size distribution of the mat particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

The light scattering layer is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, in addition to the above mat particles, in order to increase the refractive index of the layer. Thus, it is preferable that an inorganic filler having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less is contained.
Conversely, in order to increase the refractive index difference from the mat particles, it is also preferable to use a silicon oxide in order to keep the refractive index of the layer low in the light scattering layer using the high refractive index mat particles. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler to be used in the light scattering _{layer, TiO 2, ZrO 2, Al} 2 O 3, In 2 O 3, ZnO, SnO 2, Sb 2 O 3, ITO and SiO ₂ and the like. TiO ₂ and ZrO ₂ are particularly preferable from the viewpoint of increasing the refractive index. The surface of the inorganic filler is preferably subjected to silane coupling treatment or titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used. The amount of these inorganic fillers added is preferably 10% to 90% of the total mass of the light scattering layer, more preferably 20% to 80%, and particularly preferably 30% to 75%. In addition, since such a filler has a particle size sufficiently smaller than the wavelength of light, scattering does not occur, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

  The bulk refractive index of the mixture of binder and inorganic filler in the light scattering layer is preferably 1.48 to 2.00, more preferably 1.50 to 2.00, and still more preferably 1.50 to 1.0. 80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  In order to ensure surface uniformity such as coating unevenness, drying unevenness, point defects, etc., the light scattering layer should be coated with either a fluorine-based surfactant or a silicone-based surfactant, or both for forming an antiglare layer. It is preferable to contain in a composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antireflection layer appears with a smaller addition amount. The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity.

Next, an antireflection layer in which a middle refractive index layer, a high refractive index layer, and a low refractive index layer are laminated in this order on a transparent protective film will be described.
An antireflection layer comprising at least a middle refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) in order on the substrate is designed to have a refractive index satisfying the following relationship. It is preferable.
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 Further, a hard coat layer is provided between the transparent support and the medium refractive index layer. Also good. Furthermore, it may be composed of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer (for example, JP-A-8-122504, JP-A-8-110401, JP-A-10-300902, JP 2002-243906, JP 2000-11706, etc.). Other functions may be imparted to each layer, for example, an antifouling low refractive index layer or an antistatic high refractive index layer (eg, JP-A-10-206603, JP-A-2002). -243906 publication etc.) etc. are mentioned.
The haze of the antireflection layer is preferably 5% or less, more preferably 3% or less. The strength of the film 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.

(High refractive index layer and medium refractive index layer)
The antireflective layer having a high refractive index is preferably composed of a curable film containing at least an ultrafine particle of an inorganic compound having a high refractive index having an average particle diameter of 100 nm or less and a matrix binder.
The inorganic compound fine particles having a high refractive index include inorganic compounds having a refractive index of 1.65 or more, preferably those having a refractive index of 1.9 or more. Examples thereof include oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and composite oxides containing these metal atoms.
In order to obtain such ultrafine particles, the surface of the particles is treated with a surface treatment agent (for example, silane coupling agents, etc .: JP-A-11-295503, JP-A-11-153703, JP-A-2000-9908). , Anionic compounds or organometallic coupling agents: Japanese Patent Application Laid-Open No. 2001-310432, etc., and a core-shell structure with high refractive index particles as a core (Japanese Patent Application Laid-Open Nos. 2001-166104, 2001-310432, etc.) And specific dispersants (for example, JP-A No. 11-153703, US Pat. No. 6,210,858, JP-A No. 2002-2776069, etc.) and the like.

Examples of the material forming the matrix include conventionally known thermoplastic resins and curable resin films.
Furthermore, a polyfunctional compound-containing composition having at least two radically polymerizable and / or cationically polymerizable groups, and a composition containing an organometallic compound having a hydrolyzable group and a partial condensate thereof. At least one composition selected is preferred. For example, the composition as described in Unexamined-Japanese-Patent No. 2000-47004, 2001-315242, 2001-31871, 2001-296401 etc. is mentioned.
A curable film obtained from a colloidal metal oxide obtained from a hydrolyzed condensate of metal alkoxide and a metal alkoxide composition is also preferred. For example, it describes in Unexamined-Japanese-Patent No. 2001-293818.

  The refractive index of the high refractive index layer is generally 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 thickness is preferably 5 nm to 10 mμ, more preferably 10 nm to 1 μm.

(Low refractive index layer)
The low refractive index layer is formed by sequentially laminating on the high refractive index layer. The refractive index of the low refractive index layer is preferably 1.20 to 1.55, more preferably 1.30 to 1.50.
The low refractive index layer is preferably constructed as an outermost layer having scratch resistance and antifouling properties. As means for greatly improving the scratch resistance, imparting slipperiness to the surface is effective, and conventionally known thin film layer means such as introduction of silicone or introduction of fluorine can be applied.
The refractive index of the fluorine-containing compound is preferably 1.35 to 1.50. More preferably, it is 1.36-1.47. The fluorine-containing compound is preferably a compound containing a crosslinkable or polymerizable functional group containing fluorine atoms in the range of 35 to 80% by mass. For example, paragraph numbers [0018] to [0026] of Japanese Patent Application Laid-Open No. 9-222503, paragraph numbers [0019] to [0030] of Japanese Patent Application Laid-Open No. 11-38202, and paragraph numbers of Japanese Patent Application Laid-Open No. 2001-40284. [0027] to [0028], JP-A 2000-284102, and the like.
The silicone compound is a compound having a polysiloxane structure, preferably containing a curable functional group or a polymerizable functional group in the polymer chain and having a crosslinked structure in the film. For example, reactive silicone (eg, Silaplane (manufactured by Chisso Corporation), silanol group-containing polysiloxane (Japanese Patent Laid-Open No. 11-258403, etc.) and the like can be mentioned.

The crosslinking or polymerization reaction of the fluorine-containing and / or siloxane polymer having a crosslinking or polymerizable group is carried out at the same time or after the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer and the like. It is preferable to carry out by light irradiation or heating.
Also preferred is a sol-gel cured film in which an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent are cured by a condensation reaction in the presence of a catalyst.
For example, a polyfluoroalkyl group-containing silane compound or a partially hydrolyzed condensate thereof (Japanese Patent Laid-Open Nos. 58-142958, 58-147483, 58-147484, Japanese Patent Laid-Open Nos. 9-157582, 11) -106704 and the like), silyl compounds containing a poly "perfluoroalkyl ether" group which is a fluorine-containing long chain group (Japanese Patent Application Laid-Open Nos. 2000-117902, 2001-48590, 2002-53804). Etc.) and the like.

The low refractive index layer has an average primary particle diameter of 1 nm to 150 nm such as a filler (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as an additive other than the above. Low refractive index inorganic compounds, organic fine particles described in paragraphs [0020] to [0038] of JP-A-11-3820, etc.), silane coupling agents, slip agents, surfactants, and the like can be contained.
When the low refractive index layer is positioned below the outermost layer, the low refractive index layer may be formed by a vapor phase method (vacuum deposition method, sputtering method, ion plating method, plasma CVD method, etc.). The coating method is preferable because it can be manufactured at a low cost. The film thickness of the low refractive index layer is preferably 30 nm to 200 nm, more preferably 50 nm to 150 nm, and most preferably 60 nm to 120 nm.

(Other layers of antireflection layer)
Further, a hard coat layer, a forward scattering layer, a primer layer, an antistatic layer, an undercoat layer, a protective layer, and the like may be provided.

(Hard coat layer)
The hard coat layer is provided on the surface of the transparent support in order to impart physical strength to the transparent protective film provided with the antireflection layer. In particular, it is preferably provided 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 a light and / or heat curable compound. As the curable functional group, a photopolymerizable functional group is preferable, and the organometallic compound containing a hydrolyzable functional group is preferably an organic alkoxysilyl compound.
Specific examples of these compounds are the same as those exemplified for the high refractive index layer. Specific examples of the constituent composition of the hard coat layer include those described in JP-A Nos. 2002-144913, 2000-9908, and WO 00/46617.
The high refractive index layer can also serve as a hard coat layer. In such a case, it is preferable to form fine particles dispersed in the hard coat layer using the method described for the high refractive index layer.

The hard coat layer can also serve as an antiglare layer containing particles having an average particle size of 0.2 μm to 10 μm and imparted with an antiglare function (antiglare function).
The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 μm to 10 μm, more preferably 0.5 μm to 7 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.

(Antistatic layer)
When an antistatic layer is provided, it is preferable to impart conductivity with a volume resistivity of 10 ⁻⁸ Ωcm ⁻³ or less. The use of hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc. can give a volume resistivity of 10 ⁻⁸ Ωcm ⁻³ , but it depends on temperature and humidity. However, there is a problem that sufficient conductivity cannot be secured at low humidity. Therefore, a metal oxide is preferable as the antistatic layer material. Some metal oxides are colored, but if these metal oxides are used as the antistatic layer material, the entire film is colored, which is not preferable. Zn, Ti, Al, In, Si, Mg, Ba, Mo, W, or V can be given as the metal that forms the metal oxide without coloring, and a metal oxide containing this as a main component should be used. preferable. Specific examples include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₃ , MgO, BaO, MoO ₃ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, TiO ₂ and SnO ₂ are preferable. Examples of containing different atoms include, for example, additives such as Al and In for ZnO, addition of Sb, Nb and halogen elements for SnO ₂ , and addition of Nb and TA for TiO ₂ . Addition is effective. Furthermore, as described in Japanese Examined Patent Publication No. 59-6235, a material in which the above metal oxide is attached to other crystalline metal particles or fibrous materials (for example, titanium oxide) may be used. The volume resistance value and the surface resistance value are different physical values and cannot be simply compared. However, in order to ensure the conductivity of 10 ⁻⁸ Ωcm ⁻³ or less in the volume resistance value, the antistatic layer However, it is sufficient that the surface resistance value is approximately 10 ⁻¹⁰ Ω / □ or less, more preferably 10 ⁻⁸ Ω / □. The surface resistance value of the antistatic layer needs to be measured as a value when the antistatic layer is the outermost layer, and can be measured in the middle of forming the laminated film described in this specification.

  Next, the liquid crystal display device of the present invention having at least one of the cyclic polyolefin film, the polarizing plate protective film, the optical compensation film, and the polarizing plate will be described.

(Liquid crystal display device)
The cyclic polyolefin film of the present invention, the optical compensation film having the film, and the polarizing plate using the film can be used for liquid crystal cells and liquid crystal display devices in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Frequency Liquid Crystal), OCB (Optically QuantNW).
ed), HAN (Hybrid Aligned Nematic), and ECB (Electrically Controlled Birefringence) have been proposed. Of these, the IPS mode, ECB mode, OCB mode or VA mode can be preferably used.

(IPS liquid crystal display device and ECB liquid crystal display device)
The cyclic polyolefin film of the present invention is particularly advantageously used as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having IPS mode and ECB mode liquid crystal cells, or as a protective film for a polarizing plate. . In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules parallel to the substrate surface in the absence of voltage. In these embodiments, the polarizing plate using the cyclic polyolefin film of the present invention contributes to widening the viewing angle and improving the contrast.

(OCB type liquid crystal display device)
The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between an upper portion and a lower portion of the liquid crystal cell. OCB mode liquid crystal cells are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are aligned symmetrically between the upper part and the lower part of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

(VA type liquid crystal display device)
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied.
The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech.Papers 28) (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) Liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (1998)) and (4) SURVAIVAL mode liquid crystal cells (announced at LCD International 98).
The VA mode liquid crystal display device includes a liquid crystal cell and two polarizing plates disposed on both sides thereof. The liquid crystal cell carries a liquid crystal between two electrode substrates. In one aspect of the transmissive liquid crystal display device of the present invention, the optical compensation film of the present invention is disposed between the liquid crystal cell and one polarizing plate, or between the liquid crystal cell and both polarizing plates. Place two in between.
In another aspect of the transmissive liquid crystal display device of the present invention, an optical compensation film having the cyclic polyolefin film of the present invention is used as a transparent protective film of a polarizing plate disposed between a liquid crystal cell and a polarizer. That is, the transparent protective film of the polarizing plate can also serve as an optical compensation film. The above optical compensation film may be used only for the transparent protective film (between the liquid crystal cell and the polarizer) of one polarizing plate, or between the polarizing plates (between the liquid crystal cell and the polarizer). The above optical compensation film may be used for the two transparent protective films. When the optical compensation film is used only for one polarizing plate, it is particularly preferable to use it as a protective film for the liquid crystal cell side of the backlight side polarizing plate of the liquid crystal cell. For bonding to the liquid crystal cell, the cyclic polyolefin film of the present invention is preferably on the VA cell side. The other protective film may be a commonly used cellulose acylate film. For example, 40 μm to 80 μm are preferable, and examples include, but are not limited to, commercially available KC4UX2M (40 μm manufactured by Konica Capto), KC5UX (60 μm manufactured by Konica Capto), TD80 (80 μm manufactured by Fujifilm), and the like.

  In an OCB mode liquid crystal display device or a TN liquid crystal display device, an optical compensation film is used to expand the viewing angle. As the optical compensation film for OCB cell, a film provided with an optically anisotropic layer in which a discotic liquid crystal is hybrid-aligned and fixed on an optically uniaxial or biaxial film is used. As the optical compensation film for TN cell, a film in which an optical anisotropic layer in which a discotic liquid crystal is fixed in a hybrid orientation is fixed on a film having optical isotropy or an optical axis in the thickness direction. The cyclic polyolefin film of the present invention is also useful for producing the optical compensation film for OCB cell and the optical compensation film for TN cell.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example.

<Synthesis of Cyclic Polyolefin Polymer P-1>
100 parts by mass of purified toluene and 100 parts by mass of norbornene carboxylic acid methyl ester were charged into a reaction kettle. Next, ethylhexanoate-Ni 25 mmol% (based on monomer mass) dissolved in toluene, tri (pentafluorophenyl) boron 0.225 mol% (based on monomer mass), and triethylaluminum 0.25 mol% (based on monomer mass) dissolved in toluene ) Was charged into the reaction kettle. The reaction was allowed to proceed for 18 hours at room temperature with stirring. After completion of the reaction, the reaction mixture was put into excess ethanol to produce a polymer precipitate. The cyclic polyolefin polymer (P-1) obtained by purifying the precipitate was dried at 65 ° C. for 24 hours by vacuum drying.

  The obtained polymer was dissolved in tetrahydrofuran and measured for molecular weight by gel permeation chromatography. The number average molecular weight in terms of polystyrene was 79,000 and the weight average molecular weight was 205,000. The refractive index of the obtained polymer measured by Abbe's refractometer was 1.52.

[Example 1]
The following composition was put into a mixing tank and 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 to prepare a dope for film formation.

P-1 100 parts by mass Dichloromethane 326 parts by mass Methanol 28.4 parts by mass

Next, film formation was performed by a solution film formation method using the production line 1 shown in FIG.
First, the cyclic olefin resin solution was cast on a mirror surface stainless steel support of a casting band 900 set at 15 ° C. through a casting die 200. After peeling off the coating film with a residual solvent of 100% by mass, the soft film was conveyed by a tenter 700 at 80 ° C. in the volatile space 700a and 20 ° C. at the cooling space 700b.
At this time, the conveyance tension of the film-like material on the upstream side 12a in the post-drying (heating) region, the drying temperature (unit; C) was set as shown in Table 1.

[Examples 2 to 30, Comparative Examples 1 to 8]
In the same manner as in Example 1, films of Examples 2 to 30 were produced with the composition, film thickness, transport tension, and drying temperature shown in Table 1. Moreover, the film of Comparative Examples 1-8 was produced exactly the same.

The elastic modulus of each film obtained was measured using an elastic modulus measuring device (Orientec RHEOVIBRON DDV-
01FP), and the sample width was 1 cm and the strain rate was 1 mm / min. The elastic modulus of the film-like material in the post-drying region is almost the same as the elastic modulus of this film.
Further, the obtained film was stretched 1.4 times in the width direction.

  Further, the in-plane retardation (before Re heat treatment) before post-drying of the obtained film and the in-plane retardation (after Re heat treatment) after post-drying were measured by the above methods, and (after Re heat treatment) / (Re heat treatment) Before).

The number of scratches per 1 m × 1 m of the obtained stretched film was visually counted and evaluated according to the following criteria. In practical use, if it is Δ or more, there is no problem.
◎: No scratches ○: Scratches 1 to 3 △: Scratches 3 to 10 ×: 10 or more

  The evaluation results are shown in Table 1.

  In Table 1, ARTON is F5023 and ZEONOR has a product number of 1600. Manufacturers and molecular weights of other additives are as follows.

  As can be seen from Table 1, according to the production method of the present invention, a cyclic olefin film with little change in in-plane retardation Re before and after the heat treatment and few scratches can be obtained.

It is the schematic which shows a production line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Drying chamber 11 In soft film drying area | region 12 In post-drying area | region 12a Upstream side 12b Downstream side 100 Polymer solution adjustment apparatus 200 Casting die 400 Stripping roll 500 Winding apparatus 700 Tenter 700a Volatilization space 700b Cooling space 800 Roll 801 Tensile meter 810 Motor 820 Control unit 900 Casting band 910 Driving drum 920 Driven drum 930 Belt

Claims (5)

  A method for producing a cyclic olefin film comprising a step of heating a film-like material by conveying the film-like material containing a cyclic olefin-based resin and passing the film-like material through the heating region, wherein the film at the temperature in the heating region A method for producing a cyclic olefin film, wherein the elastic modulus of the film-like material is 300 MPa to 3000 MPa, and the conveying tension is 10 to 50 (N / film 1 m width). When the elastic modulus of the film-like material at the temperature in the heating region is E (MPa) and the film thickness is h (μm), E × h ³ is 1.0 × 10 ⁷ or more and 3.0 × 10 ⁹ or less. When the in-plane retardation of the film-like material before heating is (before Re heat treatment) and the in-plane retardation after heating is (after Re heat treatment), (after Re heat treatment) / (before Re heat treatment) The method for producing a cyclic olefin film according to claim 1, wherein is from 0.75 to 1.0. The cyclic olefin film contains at least one of the compounds represented by the following general formulas (1) to (5) in an amount of 1% by mass to 35% by mass with respect to the cyclic olefin resin. The manufacturing method of the cyclic olefin film of 1 or 2.

In General Formula (1), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. The total number of carbon atoms of R ¹ , R ² and R ³ is 10 or more.
In general formula (2), R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more.
In general formula (3), R ¹¹ represents an aryl group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and at least one of them is an aryl group. Moreover, the alkyl group and the aryl group may each have a substituent.
In the general formula (4), R ²¹ , R ²² and R ²³ each independently represents an alkyl group. Moreover, each alkyl group may have a substituent.
In the general formula (5), R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aromatic group. X ³¹ , X ³² , X ³³ and X ³⁴ are each a single bond, —CO— and NR ³⁵ — (R ³⁵ represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group). Represents a divalent linking group formed from one or more groups selected from the group consisting of: a, b, c and d are integers of 0 or more, and a + b + c + d is 2 or more. Z ³¹ represents an (a + b + c + d) -valent organic group (excluding a cyclic group). The cyclic olefin film contains at least one compound having a structure represented by the following general formula (9) or (10) in an amount of 1% by mass to 35% by mass with respect to the cyclic olefin resin. The manufacturing method of the cyclic olefin film of Claim 1 or 2.

In the general formulas (9) and (10), R ^{41 to} R ⁴⁸ may each independently have a linking group containing a hydrogen atom; a halogen atom; an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. Represents a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group, and R ⁴⁴ are all bonded to one another, whether they are the same atom or group, or different atoms or groups. In addition, a carbocycle or a heterocycle (these carbocycles and heterocycles may have a monocyclic structure, or other rings may be condensed to form a polycyclic structure).   The thickness of a cyclic olefin film is 30 micrometers-100 micrometers, The manufacturing method of the cyclic olefin film in any one of Claims 1-4 characterized by the above-mentioned.

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