TWI870782B - Elliptical polarizing plate - Google Patents

Abstract

The present invention provides an elliptical polarizing plate having excellent processing characteristics without defects such as waving on a cut end face even if cutting is performed.

The present invention relates to an elliptical polarizing plate having a polarizing layer, a λ/4 retardation layer, a vertically aligned liquid crystal cured layer, and a reinforcing layer; wherein the vertically aligned liquid crystal cured layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound oriented in a direction perpendicular to the plane of the liquid crystal cured layer, the film thickness of the vertically aligned liquid crystal cured layer is 3 μm or less, and the interlayer distance between the vertically aligned liquid crystal cured layer and the reinforcing layer is 5 μm or less.

Description

Elliptical polarizing plate

The present invention relates to an elliptical polarizing plate that can be used in a display, etc., and an organic EL display device including the elliptical polarizing plate.

In recent years, with the diversification of displays, there is a demand for thinner elliptical polarizers. As one method for thinning elliptical polarizers, it is known to change the phase difference plate used in the elliptical polarizer from a stretched phase difference plate to a phase difference plate formed by a liquid crystal cured film obtained by curing a polymerizable liquid crystal compound in an aligned state. For example, Patent Document 1 discloses a circular polarizer with an optical compensation function that combines a horizontally aligned λ/4 phase difference plate formed by a liquid crystal cured film and a phase difference plate formed by a liquid crystal cured film having anisotropy (also called anisotropy) in the film thickness direction.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2015-163935

However, in order to make the liquid crystal cured film contained in the elliptical polarizing plate thinner, it is formed by forming the liquid crystal cured film on the substrate, transferring it to the polarizing plate, and then peeling off the substrate. However, the mechanical strength of the liquid crystal cured film after peeling off the substrate is insufficient. Therefore, if the liquid crystal cured film formed on the substrate is transferred to the polarizing plate alone to obtain an elliptical polarizing plate, when the obtained film is cut into the size of the product that meets the purpose, defects such as wavy undulations may occur on the cut end surface.

Therefore, the purpose of the present invention is to provide an elliptical polarizing plate that does not produce defects such as wavy undulations on the cut end surface even when cut and has good processing characteristics, and an organic EL display device including the elliptical polarizing plate.

The inventor of the present invention has completed the present invention as a result of his/her efforts to solve the above-mentioned problems. That is, the present invention includes the following.

[1] An elliptical polarizing plate comprising a polarizing layer, a λ/4 phase difference layer, a vertically aligned liquid crystal curing layer and a reinforcing layer, wherein the vertically aligned liquid crystal curing layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound aligned in a vertical direction relative to the plane of the liquid crystal curing layer, and the film thickness of the vertically aligned liquid crystal curing layer is less than 3 μm.

Here, the interlayer distance between the vertically aligned liquid crystal curing layer and the reinforcing layer is, for example, less than 5 μm.

[2] An elliptical polarizing plate as described in [1], wherein the thickness of the reinforcing layer is 1 to 10 μm.

[3] An elliptical polarizing plate as described in [1] or [2], wherein the λ/4 phase difference layer is a horizontally aligned liquid crystal curing layer, and the horizontally aligned liquid crystal curing layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound that is aligned in a horizontal direction relative to the plane of the liquid crystal curing layer.

[4] An elliptical polarizing plate as described in any one of [1] to [3], which comprises a polarizing layer, a λ/4 phase difference layer, a vertically aligned liquid crystal curing layer, and a reinforcing layer in sequence.

[5] An elliptical polarizing plate as described in any one of [1] to [3], which comprises a polarizing layer, a vertically aligned liquid crystal curing layer, a reinforcing layer, and a λ/4 phase difference layer in sequence.

[6] An elliptical polarizing plate as described in any one of [1] to [3], which comprises a polarizing layer, a reinforcing layer, a vertically aligned liquid crystal curing layer, and a λ/4 phase difference layer in sequence.

[7] An elliptical polarizing plate as described in any one of [1] to [6], wherein the reinforcing layer comprises at least one selected from the group consisting of acrylic resin, epoxy resin, oxetane resin, urethane resin and melamine resin.

[8] An elliptical polarizing plate as described in any one of [1] to [7], which has an alignment layer with a thickness of 5 μm or less between the vertically aligned liquid crystal curing layer and the reinforcing layer, wherein the alignment layer is a layer composed of a compound containing Si, C and O as constituent elements.

[9] An elliptical polarizer as described in any one of [1] to [8], wherein the difference in the average in-plane refractive index at a wavelength of 550 nm between adjacent layers is less than 0.20.

[10] An elliptical polarizing plate as described in any one of [1] to [9], wherein, with respect to the λ/4 phase difference layer, in the refractive index ellipse formed by the λ/4 phase difference layer, in the range of wavelength λ=400 to 700nm, the following relationship exists,

nxQ(λ)>nyQ(λ)≒nzQ(λ) [where nxQ(λ) represents the principal refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction parallel to the phase difference layer plane; nyQ(λ) represents the refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction parallel to the phase difference layer plane and orthogonal to the direction of the aforementioned nxQ(λ); nzQ(λ) represents the refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction perpendicular to the phase difference layer plane];

And satisfy the following relationships (1) to (3),

ReQ(450)/ReQ(550)≦1.00 (1)

1.00≦ReQ(650)/ReQ(550) (2)

100nm≦ReQ(550)≦160nm (3)

[In the formula, ReQ(450) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=450nm, ReQ(550) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=550nm, ReQ(650) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=650nm, and the in-plane phase difference value ReQ(λ) of the λ/4 phase difference layer for light with a wavelength of λ(nm) is

ReQ(λ)=(nxQ(λ)-nyQ(λ))×dQ, where dQ represents the thickness of the λ/4 phase difference layer].

[11] An elliptical polarizer as described in any one of [1] to [10], wherein, with respect to the vertically aligned liquid crystal curing layer, in the refractive index ellipse formed by the vertically aligned liquid crystal curing layer, in the range of wavelength λ=400 to 700nm, the following relationship exists,

nzV(λ)>nxV(λ)≒nyV(λ)

[In the formula, nzV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer for light with a wavelength of λ(nm) in a direction perpendicular to the plane of the liquid crystal curing layer; nxV(λ) represents the maximum refractive index of the refractive index ellipse formed by the liquid crystal curing layer for light with a wavelength of λ(nm) in a direction parallel to the plane of the liquid crystal curing layer; nyV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer for light with a wavelength of λ(nm) in a direction parallel to the plane of the liquid crystal curing layer and orthogonal to the direction of nxV; however, in the case of nxV(λ)=nyV(λ), nxV(λ) represents the refractive index in any direction parallel to the plane of the liquid crystal curing layer]; and the following relationships (4) to (6) are satisfied,

RthV(450)/RthV(550)≦1.00 (4)

1.00≦RthV(650)/RthV(550) (5)

-120nm≦RthV(550)≦-50nm (6)

[In the formula, RthV(450) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=450nm, RthV(550) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=550nm, RthV(650) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=650nm, and the phase difference value RthV(λ) in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ(nm) is

RthV(λ)=[(nxV(λ)+nyV(λ))/2-nzV(λ)]×dV; Here, in the refractive index ellipse formed by the liquid crystal curing layer, nzV(λ) represents the principal refractive index in the direction perpendicular to the plane of the liquid crystal curing layer at a wavelength of λ(nm), and "(nxV(λ)+nyV(λ))/2" represents the average refractive index in the plane of the liquid crystal curing layer at a wavelength of λ(nm); dV represents the thickness of the liquid crystal curing layer].

[12] An organic EL display device comprising an elliptical polarizing plate as described in any one of [1] to [11].

[13] An organic EL display device comprising an elliptical polarizing plate as described in any one of [1] to [12].

The elliptical polarizing plate of the present invention will not produce defects such as wavy shapes on the cut end surface even if it is cut, and has good processing characteristics.

1,10,100: elliptical polarizing plate

2: Polarizing layer

3: Adhesive layer

4:λ/4 phase difference layer

5: Orientation layer

6: Vertically aligned liquid crystal hardened layer

7: Vertical alignment layer

8: Reinforcement layer

Figure 1 is a schematic cross-sectional view showing an example of the layer structure of the elliptical polarizing plate of the present invention.

Figure 2 is a schematic cross-sectional view showing an example of the layer structure of the elliptical polarizing plate of the present invention.

Figure 3 is a schematic cross-sectional view showing an example of the layer structure of the elliptical polarizing plate of the present invention.

The elliptical polarizing plate of the present invention has a polarizing layer, a λ/4 phase difference layer, a vertically aligned liquid crystal curing layer and a reinforcing layer, and the stacking order of each layer can be appropriately selected. In a preferred embodiment, each layer is stacked in the following order. Polarizing layer, λ/4 phase difference layer, vertically aligned liquid crystal curing layer, reinforcing layer; polarizing layer, vertically aligned liquid crystal curing layer, reinforcing layer, λ/4 phase difference layer; polarizing layer, reinforcing layer, vertically aligned liquid crystal curing layer, λ/4 phase difference layer.

An example of the layer structure of the elliptical polarizing plate of the present invention stacked in this order is shown in Figures 1 to 3, but the present invention is not limited to this aspect.

The elliptical polarizing plate 1 shown in FIG. 1 sequentially comprises a polarizing layer 2, an adhesive layer 3, a λ/4 phase difference layer 4, an alignment layer 5, an adhesive layer 3, a vertical alignment liquid crystal curing layer 6, a vertical alignment layer 7, and a reinforcing layer 8. The elliptical polarizing plate 10 shown in FIG. 2 sequentially comprises a polarizing layer 2, an adhesive layer 3, a vertical alignment liquid crystal curing layer 6, a vertical alignment layer 7, a reinforcing layer 8, an adhesive layer 3, a λ/4 phase difference layer 4, and an alignment layer 5. The elliptical polarizing plate 100 shown in FIG. 3 sequentially comprises a polarizing layer 2, an adhesive layer 3, a reinforcing layer 8, a vertical alignment layer 7, a vertical alignment liquid crystal curing layer 6, an adhesive layer 3, a λ/4 phase difference layer 4, and an alignment layer 5. The elliptical polarizing plates 1, 10, and 100 are bonded together in such a way that the absorption axis of the polarizing layer 2 is substantially 45° with respect to the slow axis (optical axis) of the λ/4 phase difference layer 4. In addition, the polarizing layer 2 may have a transparent protective film on one side of the polarizing plate (the side opposite to the adhesive layer 3). In this specification, the so-called substantially 45° is usually in the range of 45°±5°.

[Reinforcement layer]

The elliptical polarizing plates 1, 10 and 100 of the present invention have a reinforcing layer 8, and the reinforcing layer 8 has a function of reinforcing the layers (particularly the vertical alignment liquid crystal curing layer 6) included in the elliptical polarizing plates. In the elliptical polarizing plates 1, 10 and 100, even if the vertical alignment liquid crystal curing layer 6 is a thin film, the reinforcing layer 8 can still fully reinforce the strength of the vertical alignment liquid crystal curing layer 6. If the distance between the vertical alignment liquid crystal curing layer 6 and the reinforcing layer 8 is small, the strength of the vertical alignment liquid crystal curing layer 6 can be more fully reinforced. Therefore, the processing characteristics of the elliptical polarizing plates are improved, and the defects of the cut end surface can be effectively suppressed or prevented. Furthermore, in this specification, the so-called "interlayer distance" refers to the shortest distance between the vertically aligned liquid crystal curing layer 6 and the reinforcing layer 8, and the so-called "processing characteristics" refers to the characteristics that can suppress or prevent the generation of defects such as wavy undulations on the cut end surface when cutting the elliptical polarizing plate.

The interlayer distance between the vertical alignment liquid crystal curing layer 6 and the reinforcing layer 8 is, for example, 5 μm or less, preferably 3 μm or less, more preferably 1.5 μm or less, still more preferably 1.0 μm or less, still more preferably 500 nm or less, and particularly preferably 300 nm or less. If there is no vertical alignment layer 7, the interlayer distance is 0 nm. The lower limit of the interlayer distance is necessarily determined by the film thickness of the layer between the vertical alignment liquid crystal curing layer 6 and the reinforcing layer 8 (the film thickness of the vertical alignment layer 7 in the embodiment of FIGS. 1 to 3), so there is no particular limitation, but it is preferably 1 nm or more. When the interlayer distance is below the upper limit, the reinforcing layer 8 can more fully reinforce the vertically aligned liquid crystal curing layer 6, and can show good processing characteristics. Therefore, when cutting the elliptical polarizing plate, no defects such as wavy undulations will occur on the cut end surface. Moreover, the shorter the interlayer distance, the easier it is for the reinforcing layer 8 to contribute to the reinforcement of the vertically aligned liquid crystal curing layer 6, so there is a tendency to improve processing characteristics.

The reinforcing layer 8 is composed of a material capable of reinforcing the strength of the vertically aligned liquid crystal curing layer 6, for example, at least one selected from the group consisting of acrylic resin, epoxy resin, cyclobutane oxide resin, urethane resin and melamine resin. Among them, from the perspective of easily forming a reinforcing layer 8 with high curability and high reinforcement, it is preferably composed of at least one selected from the group consisting of acrylic resin, epoxy resin, cyclobutane oxide resin, urethane resin and melamine resin, and more preferably at least one selected from the group consisting of acrylic resin and urethane resin.

The reinforcing layer 8 is preferably a hardened material of a hardening composition including a hardening material that hardens with heat or light. The curable material of the reinforcement layer 8 composed of acrylic resin can be exemplified by: monofunctional (meth)acrylates, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate; polyfunctional (meth)acrylates, such as ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trihydroxymethylpropane triacrylate, trihydroxymethylethane triacrylate, tetrahydroxymethylmethane triacrylate, tetrahydroxymethylmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, Dipentatriol pentaacrylate, dipentatriol hexaacrylate, 3-(acryloyloxyethyl) trimer isocyanate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trihydroxymethylpropane trimethacrylate, trihydroxymethylethane trimethacrylate, tetrahydroxymethylmethane trimethacrylate, tetrahydroxymethylmethane tetramethacrylate, pentaglycerol trimethacrylate, pentatriol trimethacrylate, pentatriol tetramethacrylate, glycerol trimethacrylate, dipentatriol trimethacrylate, dipentatriol tetramethacrylate, dipentatriol pentamethacrylate, dipentatriol hexamethacrylate, 3-(methacryloyloxyethyl) trimer isocyanate, etc. (Meth)acrylates can be used alone or in combination of two or more. (Meth)acrylates can be appropriately selected from the viewpoints of suppressing curling caused by heating during and after curing, improving processing characteristics, and ensuring sufficient reinforcement of the reinforcing layer 8. Moreover, from the same viewpoint, they can be mixed with epoxy resins, cyclohexane resins, amine resins, melamine resins, etc. Furthermore, in this specification, acrylates and methacrylates are sometimes collectively referred to as (meth)acrylates, and acrylic acid and methacrylic acid are sometimes collectively referred to as (meth)acrylic acid.

The curable material of the reinforcing layer 8 composed of an amine resin may be, for example, an amine (meth)acrylate that is a reaction product of (meth)acrylic acid and/or (meth)acrylate, polyol, and diisocyanate. Specifically, the amine (meth)acrylate can be produced by preparing a hydroxy (meth)acrylate having at least one hydroxyl group in the molecule from (meth)acrylic acid and/or (meth)acrylate and polyol, and reacting it with diisocyanate. The amine (meth)acrylate can be used alone or in combination of two or more.

The aforementioned (meth)acrylate may be a chain or cyclic alkyl ester of (meth)acrylate. Specific examples thereof include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, and cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate. The aforementioned polyol is a compound having at least two hydroxyl groups in the molecule. For example, ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,3-pentanediol, neopentyl glycol ester of hydroxyl neopentanoic acid, , cyclohexanedihydroxymethyl, 1,4-cyclohexanediol, spiroglycol, tricyclodecanedihydroxymethyl, hydrogenated bisphenol A, ethylene oxide added bisphenol A, propylene oxide added bisphenol A, trihydroxymethyl ethane, trihydroxymethyl propane, glycerol, 3-methylpentane-1,3,5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, etc.

Diisocyanates are compounds with two isocyanate groups (-NCO) in the molecule, and various aromatic, aliphatic or alicyclic diisocyanates can be used. Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diphenyl diisocyanate, xylylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and the nuclear hydrogenation products of diisocyanates having aromatic rings among them.

From the perspective of suppressing curling caused by heating during and after curing, improving processing characteristics, and ensuring sufficient reinforcement of the reinforcing layer 8, urethane (meth)acrylate can be appropriately selected. Moreover, from the same perspective, it can also be mixed with acrylic resin, epoxy resin, cyclohexane resin, melamine resin, etc.

The curable material of the reinforcing layer including epoxy resin may include, for example, aliphatic epoxy compounds, aromatic epoxy compounds, hydrogenated epoxy compounds, aliphatic epoxy compounds, etc.

Alicyclic epoxy compounds are compounds having at least one epoxy group directly bonded to an alicyclic ring in the molecule. Examples thereof include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate, ethylenebis(3,4-epoxycyclohexanecarboxylate), bis(3,4-epoxycyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, diethylene glycol bis(3,4-epoxycyclohexylmethyl ether), and ethylene glycol bis(3,4-epoxycyclohexylmethyl)ether. These alicyclic epoxy compounds can be used alone or in combination of two or more.

Aromatic epoxy compounds are compounds having an aromatic ring and an epoxy group in the molecule. Specific examples thereof include: bisphenol-type epoxy compounds or oligomers thereof such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S; novolac-type epoxy resins such as phenol novolac epoxy resin, cresol novolac epoxy resin, and hydroxybenzaldehyde phenol novolac epoxy resin; polyfunctional epoxy compounds such as glycidyl ether of 2,2',4,4'-tetrahydroxydiphenylmethane and glycidyl ether of 2,2',4,4'-tetrahydroxybenzophenone; polyfunctional epoxy resins such as epoxidized polyvinylphenol, and the like. These aromatic epoxy compounds can be used alone or in combination of two or more.

Hydrogenated epoxy compounds are obtained by hydrogenating the nuclei of the above-mentioned aromatic epoxy compounds. They can be produced by the following method: using a polyol (typically a hydrogenated bisphenol) obtained by selectively hydrogenating an aromatic polyhydroxy compound (typically a bisphenol) belonging to the corresponding aromatic epoxy compound in the presence of a catalyst and under pressure as a raw material, reacting it with epichlorohydrin to form a chlorohydrin ether, and further using a base to perform intramolecular ring closure. These hydrogenated epoxy compounds can be used alone or in combination of two or more.

Aliphatic epoxy compounds include polyglycidyl ethers of aliphatic polyols or their epoxy adducts. Specific examples include diglycidyl ether of neopentyl glycol, diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerol, triglycidyl ether of trihydroxymethylpropane, diglycidyl ether of polyethylene glycol, diglycidyl ether of propylene glycol, polyglycidyl ether of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide, propylene oxide) to aliphatic polyols such as ethylene glycol, propylene glycol, and glycerol. These aliphatic epoxy compounds can be used alone or in combination of two or more.

From the perspective of suppressing curling caused by heating during and after curing, improving processing characteristics, ensuring sufficient reinforcement of the reinforcing layer 8, and adjusting the adhesion with the substrate and the liquid crystal curing layer, the epoxy resin can be appropriately selected. Moreover, from the same perspective, it can also be mixed with acrylic resin, urethane resin, cyclohexane resin, melamine resin, etc.

Examples of the curable material of the reinforcing layer 8 comprising an oxycyclobutane resin include compounds containing at least one oxycyclobutane group in the molecule. Specific examples thereof include 3-ethyl-3-hydroxymethylcyclohexyloxybutane (also called cyclohexyloxybutane alcohol), 2-ethylhexylcyclohexyloxybutane, 1,4-bis[{(3-ethylcyclohexyloxybutane-3-yl)methoxy}methyl]benzene (also called benzyldimethylcyclohexyloxybutane), 3-ethyl-3[{(3-ethylcyclohexyloxybutane-3-yl)methoxy}methyl]cyclohexyloxybutane, 3-ethyl-3-(phenoxymethyl)cyclohexyloxybutane, 3-(cyclohexyloxy)methyl-3-ethylcyclohexyloxybutane, etc.

As for the curable material of the reinforcing layer 8 composed of melamine resin, melamine compounds such as hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, and hexabutoxymethyl melamine can be cited.

The curable composition used to form the reinforcement layer may further include additives such as photopolymerization initiators, thermal polymerization initiators, solvents, polymerization inhibitors, photosensitizers, levelers, antioxidants, chain transfer agents, light stabilizers, adhesives, fillers, flow regulators, plasticizers, defoamers, pigments, antistatic agents, and ultraviolet absorbers.

Regarding the photopolymerization initiator, when using a curable composition that cures by free radical polymerization, such as (meth)acrylate, amine (meth)acrylate as the curable material, a photo free radical polymerization initiator can be used; when using a curable composition that cures by cationic polymerization, such as epoxy compounds, oxycyclobutane compounds as the curable composition, a photo cationic polymerization initiator can be used; when using a curable composition that cures by heat, such as melamine compounds as the curable composition, a thermal polymerization initiator can be used.

化合物等，光陽離子聚合引發劑可舉例如芳香族重氮鹽、芳香族錪鹽、芳香族鋶鹽等的鎓鹽、鐵-芳烴錯合物等。具體而言，可舉例如：Irgacure(註冊商標)907、Irgacure 184、Irgacure 651、Irgacure 819、Irgacure 250、Irgacure 369、Irgacure 379、 Irgacure 127、Irgacure 2959、Irgacure 754、Irgacure 379EG(以上日本BASF股份公司製)；SEIKUOL BZ、SEIKUOL Z、SEIKUOL BEE(以上精工化學股份公司製)；Kayacure BP100(日本化藥股份公司製)；Kayacure UVI-6992(Dow公司製)；ADEKA Optomer SP-152、ADEKA Optomer SP-170、ADEKA Optomer N-1717、ADEKA Optomer N-1919、ADEKA ARKLS NCI-831、ADEKA ARKLS NCI-930(以上ADEKA股份公司製)；TAZ-A、TAZ-PP(以上日本Siber Hegner公司製)及TAZ-104(三和化學公司製)；KAYARAD(註冊商標)系列(日本化藥股份公司製)；CYRACURE UVI系列(Dow Chemical公司製)；CPI系列(SAN-APRO股份公司製)；TAZ、BBI及DTS(以上Midori化學股份公司製)；RHODORSIL(註冊商標)(Rhodia股份公司製)等。光聚合引發劑可單獨使用或組合2種以上使用。光聚合引發劑可配合所使用的材料，適當地選擇使用。 Examples of the photopolymerization initiator include photoradical polymerization initiators and photocationic polymerization initiators. Examples of the photoradical polymerization initiator include benzoin compounds, benzophenone compounds, benzodione ketal compounds, α-hydroxy ketone compounds, α-amino ketone compounds, tris(2-hydroxy-2-one) compounds, and 1,2-dione ketone compounds.

Compounds, etc., and examples of the photo-ion polymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, aromatic stibnium salts, and iron-aromatic complexes. Specifically, for example, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369, Irgacure 379, Irgacure 127, Irgacure 2959, Irgacure 754, Irgacure 379EG (all manufactured by BASF Japan Co., Ltd.); SEIKUOL BZ, SEIKUOL Z, SEIKUOL BEE (all manufactured by Seiko Chemical Co., Ltd.); Kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.); Kayacure UVI-6992 (manufactured by Dow); ADEKA Optomer SP-152, ADEKA Optomer SP-170, ADEKA Optomer N-1717, ADEKA Optomer N-1919, ADEKA ARKLS NCI-831, ADEKA ARKLS NCI-930 (all manufactured by ADEKA Co., Ltd.); TAZ-A, TAZ-PP (all manufactured by Nippon Siber Hegner Co., Ltd.) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.); KAYARAD (registered trademark) series (manufactured by Nippon Kayaku Co., Ltd.); CYRACURE UVI series (manufactured by Dow Chemical Co., Ltd.); CPI series (manufactured by SAN-APRO Co., Ltd.); TAZ, BBI and DTS (all manufactured by Midori Chemical Co., Ltd.); RHODORSIL (registered trademark) (manufactured by Rhodia Co., Ltd.), etc. The photopolymerization initiator can be used alone or in combination of two or more. The photopolymerization initiator can be appropriately selected and used in combination with the materials used.

Since the energy emitted from the light source can be fully utilized and the productivity is good, the photopolymerization initiator preferably has a maximum absorption wavelength of 300nm to 400nm, and more preferably 300nm to 380nm. Among them, α-acetophenone-based polymerization initiators and oxime-based photopolymerization initiators are preferred.

Examples of α-acetophenone-based polymerization initiators include 2-methyl-2-morpholinyl-1-(4-methylthiophenyl)propane-1-one, 2-dimethylamino-1-(4-morpholinylphenyl)-2-benzylbutane-1-one, and 2-dimethylamino-1-(4-morpholinylphenyl)-2-(4-methylphenylmethyl)butane-1-one, and more preferably 2-methyl-2-morpholinyl-(4-methylthiophenyl)propane-1-one and 2-dimethylamino-1-(4-morpholinylphenyl)-2-benzylbutane-1-one. Examples of commercially available α-acetophenone compounds include Irgacure 369, 379EG, 907 (all manufactured by BASF Japan Co., Ltd.) and SEIKUOL BEE (all manufactured by Seiko Chemical Industries, Ltd.).

化合物、肟酯型咔唑化合物，從感度的觀點來看，更佳為肟酯型咔唑化合物。肟酯型咔唑化合物可舉例如1,2-辛烷二酮、1-[4-(苯硫基)-2-(O-苯甲醯基肟)]、乙酮,1-[9-乙基-6-(2-甲基苯甲醯基)-9H-咔唑-3-基]-1-(O-乙醯基肟)等。肟酯型咔唑化合物的市售品可舉例如Irgacure OXE-01、Irgacure OXE-02、Irgacure OXE-03(以上日本BASF股份公司製)、ADEKA Optomer N-1919、ADEKA ARKLS NCI-831(以上ADEKA股份公司製)等。 Oxime-based photopolymerization initiators generate free radicals by light irradiation. The free radicals are suitable for polymerizing the curable composition deep in the layer. In addition, from the perspective of more efficiently carrying out the polymerization reaction deep in the layer, it is preferable to use a photopolymerization initiator that can efficiently utilize ultraviolet rays with a wavelength of 350nm or more. The photopolymerization initiator that can efficiently utilize ultraviolet rays with a wavelength of 350nm or more is preferably three

Compounds and oxime ester carbazole compounds are preferred. From the viewpoint of sensitivity, oxime ester carbazole compounds are more preferred. Examples of oxime ester carbazole compounds include 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime), etc. Examples of commercially available oxime ester carbazole compounds include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (all manufactured by BASF Japan Co., Ltd.), ADEKA Optomer N-1919, ADEKA ARKLS NCI-831 (all manufactured by ADEKA Co., Ltd.), etc.

Examples of thermal polymerization initiators include: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 2,2'-azobis(2-hydroxymethylpropionitrile ) and other azo compounds; organic peroxides such as lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl perbenzoate, isopropyl hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. These thermal polymerization initiators can be used alone or in combination of two or more.

The amount of polymerization initiator added is usually 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass relative to 100 parts by mass of the curable composition. If it is within the above range, the curing reaction can be easily and fully carried out.

The curable material is usually applied to the substrate in a state of being dissolved in a solvent, so the curable material preferably contains a solvent. The solvent is preferably a solvent that can dissolve the curable composition, and preferably a solvent that is inert to the polymerization reaction of the curable material. Examples of the solvent include: alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl Ketone solvents such as isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aliphatic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone, etc. These solvents can be used alone or in combination of two or more. Among them, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents and aromatic hydrocarbon solvents are preferred.

The content of the solvent is preferably 50 to 98 parts by mass, and more preferably 60 to 95 parts by mass, relative to 100 parts by mass of the curable composition. Therefore, the solid component in 100 parts by mass of the composition is preferably 2 to 50 parts by mass. In this range, the viscosity of the curable composition becomes lower, so the thickness of the reinforcing layer becomes roughly uniform, and the reinforcing layer tends to be less prone to unevenness.

The curable composition can be obtained by stirring the curable material and the components other than the curable material such as the additive at a predetermined temperature.

Regarding the reinforcing layer 8, the curable composition can be applied on the substrate, the solvent is removed, and the reinforcing layer 8 is hardened by heating and/or active energy rays.

Examples of the method for coating the curable composition on the substrate (hereinafter referred to as coating method A) include extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, slit coating, micro gravure coating, die coating, inkjet coating, etc. In addition, examples of coating methods include a coating method using a coating machine such as a dip coater, a rod coater, or a rotary coater. Among them, in the case of continuous coating in roll to roll mode, the preferred coating methods are micro-gravure coating, inkjet coating, slit coating, and die head coating.

The method for removing the solvent (hereinafter referred to as solvent removal method A) may include natural drying, ventilation drying, heating drying, reduced pressure drying and a combination of these methods. Of these, natural drying or heating drying is preferred. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, and even more preferably in the range of 50 to 130°C. The drying time is preferably in the range of 10 seconds to 20 minutes, and more preferably in the range of 30 seconds to 10 minutes.

The active energy rays to be irradiated are appropriately selected according to the type of curable composition, the type of photopolymerization initiator when a photopolymerization initiator is included, and the amount thereof. Specifically, for example, one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α rays, β rays, and γ rays can be cited. Among them, ultraviolet light is preferred in terms of the ease of controlling the progress of the polymerization reaction and the ability to use a widely used photopolymerization device in the field, and the type of polymerizable liquid crystal compound is preferably selected in a manner that can be photopolymerized by ultraviolet light.

The light source of the aforementioned active energy line can be, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light in the wavelength range of 380 to 440 nm, a fluorescent lamp for insect traps, a black light lamp, a microwave-excited mercury lamp, a metal halogen lamp, etc.

The ultraviolet irradiation intensity is usually 10 to 3000 mW/cm ² . The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activation of a photo-cationic polymerization initiator or a photo-radical polymerization initiator. The irradiation time is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and even more preferably 0.1 second to 1 minute. When irradiating once or multiple times with such an ultraviolet irradiation intensity, the cumulative light amount is 10 to 3000 mJ/cm ² , preferably 50 to 2000 mJ/cm ² , and more preferably 100 to 1000 mJ/cm ² . When the accumulated light amount is below this range, the curing of the curable composition becomes insufficient, and the processing characteristics of the elliptical polarizing plate may be reduced. On the contrary, when the accumulated light amount is above this range, the elliptical polarizing plate may be colored.

In the case of hardening the hardening composition by heat, the heating temperature is appropriately selected according to the type of hardening material, the type of thermal polymerization initiator when a thermal polymerization initiator is included, and the amount thereof, for example, 50 to 200°C, preferably 50 to 130°C. The heating time is, for example, 10 seconds to 10 minutes, preferably 10 seconds to 5 minutes. Furthermore, in the case of heat drying, drying and hardening can be performed simultaneously.

The thickness of the reinforcing layer 8 is preferably 1 to 10 μm from the viewpoint of reinforcement. When the thickness of the reinforcing layer 8 is greater than the above lower limit, the layers contained in the elliptical polarizing plate, especially the vertically aligned liquid crystal curing layer 6, can be sufficiently reinforced, and good processing characteristics can be exhibited. When the thickness of the reinforcing layer 8 is less than the above upper limit, it is preferred from the viewpoint of thinning the elliptical polarizing plate. The thickness of the reinforcing layer 8 is preferably 1 to 5 μm, more preferably 1 to 3 μm, from the viewpoint of thinning the elliptical polarizing plate, and is preferably 5 to 10 μm, more preferably 7 to 10 μm from the viewpoint of processing characteristics of the elliptical polarizing plate. The film thickness of the reinforcement layer can be measured using an elliptical polarizer or a contact film thickness gauge.

[Polarizing layer]

The polarizing layer 2 is a layer having a polarizing function. Such a layer may include, for example, a stretched film adsorbed with a dye having absorption anisotropy or a film coated with a dye having absorption anisotropy as a polarizer. The dye having absorption anisotropy may be, for example, a dichroic dye.

The film comprising a stretched film adsorbed with a dye having absorption anisotropy as a polarizer is usually produced by sandwiching a transparent protective film through an adhesive on at least one side of the polarizer, and the polarizer is produced by stretching a polyvinyl alcohol resin film in one axis, dyeing the polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye, treating the polyvinyl alcohol resin film adsorbed with the dichroic dye with a boric acid aqueous solution, and washing with water after the treatment with the boric acid aqueous solution.

Polyvinyl alcohol resins can be obtained by saponifying polyvinyl acetate resins. As for polyvinyl acetate resins, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith can also be used. Other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having ammonium groups, etc.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin can be modified, for example, polyvinyl formal or polyvinyl acetaldehyde modified by aldehydes can be used. The polymerization degree of the polyvinyl alcohol resin is usually about 1000 to 10000, preferably in the range of 1500 to 5000.

The film obtained by forming such a polyvinyl alcohol resin can be used as the embryonic membrane of the polarizing layer 2. The method of forming the polyvinyl alcohol resin into a film is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based embryonic membrane can be set to about 10 to 150 μm, for example.

The one-axis stretching of the polyvinyl alcohol resin film can be performed before, at the same time as, or after dyeing with a dichroic dye. When the one-axis stretching is performed after dyeing, the one-axis stretching can be performed before or during the boric acid treatment. Moreover, the one-axis stretching can also be performed in these multiple stages. During the one-axis stretching, the one-axis stretching can be performed between rollers with different circumferential speeds, or the one-axis stretching can be performed using a hot roller. Moreover, the one-axis stretching can be dry stretching performed in the atmosphere, or wet stretching using a solvent and stretching the polyvinyl alcohol resin film in a swollen state. The stretching ratio is usually about 3 to 8 times.

The polyvinyl alcohol resin film can be dyed with a dichroic dye by, for example, immersing the polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye.

Specifically, dichroic pigments can be iodine or dichroic organic dyes. Examples of dichroic organic dyes include dichroic direct dyes made from disazo compounds such as C.I. Direct Red 39 and dichroic direct dyes made from trisazo, tetrakisazo and other compounds. The polyvinyl alcohol resin film is preferably immersed in water before dyeing.

When iodine is used as a dichroic pigment, a method of dyeing is usually adopted in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide. The iodine content in the aqueous solution is usually about 0.01 to 1 mass part per 100 mass parts of water. Moreover, the potassium iodide content is usually about 0.5 to 20 mass parts per 100 mass parts of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. Moreover, the immersion time in the aqueous solution (dyeing time) is usually about 20 to 1800 seconds.

On the other hand, when a dichroic organic dye is used as a dichroic pigment, a method of dyeing is usually adopted in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing a water-soluble dichroic dye. The content of the dichroic organic dye in the aqueous solution is usually about 1× ^10-4 to 10 parts by mass, preferably about 1× ^10-3 to 1 part by mass, and more preferably about 1× ^10-3 to 1× ^10-2 parts by mass per 100 parts by mass of water. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing auxiliary. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. Moreover, the immersion time (dyeing time) in the aqueous solution is usually about 10 to 1800 seconds.

The boric acid treatment after dyeing with a dichroic pigment can usually be carried out by immersing the dyed polyvinyl alcohol-based resin film in an aqueous boric acid solution. The content of boric acid in the aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. In the case of using iodine as the dichroic pigment, the aqueous boric acid solution preferably contains potassium iodide, and the content of potassium iodide in this case is usually about 0.1 to 15 parts by mass, preferably about 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the aqueous boric acid solution is usually about 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid aqueous solution is usually above 50°C, preferably 50 to 85°C, and more preferably 60 to 80°C.

The polyvinyl alcohol resin film treated with boric acid is usually washed with water. The washing treatment can be performed, for example, by immersing the polyvinyl alcohol resin film treated with boric acid in water. The temperature of the water for the washing treatment is usually about 5 to 40°C. Moreover, the immersion time is usually about 1 to 120 seconds.

After washing, drying treatment is performed to obtain a polarizer. Drying treatment can be performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The time of the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds. Through the drying treatment, the moisture content of the polarizer is reduced to a practical level. The moisture content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is lower than 5% by weight, the flexibility of the polarizer is lost, and the polarizer is damaged or cracked after drying. Moreover, when the moisture content is higher than 20% by weight, the thermal stability of the polarizer may deteriorate.

The thickness of the polarizer obtained by uniaxially stretching the polyvinyl alcohol resin film, dyeing with a dichroic pigment, treating with boric acid, washing with water and drying is preferably 5 to 40 μm.

The film coated with a dye having absorption anisotropy may be, for example, a film obtained by coating a composition containing a dichroic dye having liquid crystal properties or a composition containing a dichroic dye and polymerizable liquid crystal. The film preferably has a protective film on one or both sides. The protective film may be, for example, the same as the substrate described below.

The film coated with the anisotropically absorbing pigment is preferably thin, but if it is too thin, the strength decreases and the processability tends to be poor. The thickness of the film is usually less than 20 μm, preferably less than 5 μm, and more preferably 0.5 to 3 μm.

The aforementioned film coated with a pigment having anisotropic absorption may specifically include a film described in Japanese Patent Publication No. 2012-33249.

The polarizing layer 2 is obtained by depositing a transparent protective film through a bonding agent on at least one side of the polarizer obtained in this way. The transparent protective film is preferably the same transparent film as the substrate described later.

[λ/4 phase difference layer]

The λ/4 phase difference layer 4 is a layer having anisotropy of the refractive index within the film surface. Although the λ/4 phase difference layer 4 can be formed by stretching or shrinking a polymer film, from the perspective of thinning the elliptical polarizing plate, it is preferably formed by polymerizing a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound (also called polymerizable liquid crystal) in an aligned state.

The three-dimensional refractive index ellipse formed by the λ/4 phase difference layer 4 may be biaxial, but preferably uniaxial. The λ/4 phase difference layer 4 is preferably a horizontally aligned liquid crystal curing layer composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound that is aligned in a horizontal direction relative to the plane of the λ/4 phase difference layer.

The horizontally aligned liquid crystal curing layer is a layer in which the optical axis of the polymerizable liquid crystal is aligned in the horizontal direction relative to the plane of the λ/4 phase difference layer. The polymerizable liquid crystal constituting the λ/4 phase difference layer can be a rod-shaped or disc-shaped polymerizable liquid crystal. When the rod-shaped polymerizable liquid crystal is aligned horizontally or vertically relative to the plane of the λ/4 phase difference layer, the optical axis of the polymerizable liquid crystal is consistent with the long axis direction of the polymerizable liquid crystal. When the disc-shaped polymerizable liquid crystal is aligned, the optical axis of the polymerizable liquid crystal exists in a direction orthogonal to the disc plane of the polymerizable liquid crystal.

The refractive indices nx, ny and nz in three directions in the refractive index ellipse formed by the alignment of the polymerizable liquid crystal can be, for example, nx>ny ≒nz (called positive A plate), nx≒ny<nz (called positive C plate), nx<ny≒nz (called negative A plate) or nx≒ny>nz (called negative C plate). nx represents the principal refractive index in the direction parallel to the plane of the λ/4 phase difference layer in the refractive index ellipse formed by the λ/4 phase difference layer. ny represents the refractive index in the direction parallel to the plane of the λ/4 phase difference layer and orthogonal to the direction of nx in the refractive index ellipse formed by the λ/4 phase difference layer. nz represents the refractive index in the direction perpendicular to the plane of the λ/4 phase difference layer in the refractive index ellipse formed by the λ/4 phase difference layer.

The λ/4 phase difference layer 4 can use either rod-shaped polymeric liquid crystal or disc-shaped polymeric liquid crystal, but rod-shaped polymeric liquid crystal is preferred. When the rod-shaped polymeric liquid crystal forms a horizontally aligned liquid crystal curing layer, the λ/4 phase difference layer is a positive A plate.

Regarding the λ/4 phase difference layer 4, in the refractive index ellipse formed by the λ/4 phase difference layer, in the range of wavelength λ=400 to 700nm, there is the following relationship,

nxQ(λ)>nyQ(λ)≒nzQ(λ)

[In the formula, nxQ(λ) represents the principal refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction parallel to the phase difference layer plane; nyQ(λ) represents the refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction parallel to the phase difference layer plane and orthogonal to the direction of the aforementioned nxQ(λ); nzQ(λ) represents the refractive index of the refractive index ellipse formed by the λ/4 phase difference layer for light with a wavelength of λ(nm) in a direction perpendicular to the phase difference layer plane];

And satisfy the following relationships (1) to (3),

ReQ(450)/ReQ(550)≦1.00 (1)

1.00≦ReQ(650)/ReQ(550) (2)

100nm≦ReQ(550)≦160nm (3)

[In the formula, ReQ(450) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=450nm, ReQ(550) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=550nm, ReQ(650) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=650nm, and the in-plane phase difference value ReQ(λ) of the λ/4 phase difference layer for light with a wavelength of λ(nm) is

ReQ(λ)=(nxQ(λ)-nyQ(λ))×dQ, where dQ represents the thickness of the λ/4 phase difference layer].

When the in-plane phase difference value ReQ(550) of the λ/4 phase difference layer 4 exceeds the range of formula (3), the hue of the front side of the display including the elliptical polarizer may become red or blue. The more preferable range of the in-plane phase difference value is 130nm≦ReQ(550)≦150nm. When ReQ(450)/ReQ(550) of the λ/4 phase difference layer exceeds 1.00, the ellipticity of the elliptical polarizer having the λ/4 phase difference layer on the short-wavelength side deteriorates. When the ellipticity of the circular polarizer on the short-wavelength side deteriorates and becomes smaller than 1.0, the function of the circular polarizer as a circular polarizer when viewed from the front on the short-wavelength side is impaired. The [ReQ(450)/ReQ(550)] is preferably 0.75 to 0.92, more preferably 0.77 to 0.87, and even more preferably 0.79 to 0.85.

The in-plane phase difference value of the λ/4 phase difference layer 4 can be adjusted according to the thickness dQ of the λ/4 phase difference layer. The in-plane phase difference value is determined by the above formula ReQ(λ)=(nxQ(λ)-nyQ(λ))×dQ, so to obtain the desired in-plane phase difference value (ReQ(λ): the in-plane phase difference value of the λ/4 phase difference layer at wavelength λ(nm)), the 3D refractive index and the film thickness dQ can be adjusted. Furthermore, the 3D refractive index depends on the molecular structure and orientation state of the polymerizable liquid crystal compound described later.

From the perspective of thin film, the upper limit of the film thickness of the λ/4 phase difference layer 4 is preferably 5μm or less, more preferably 3μm or less, and even more preferably 2.5μm or less. Moreover, the lower limit of the film thickness of the λ/4 phase difference layer 4 is preferably 0.1μm or more, more preferably 0.5μm or more, and even more preferably 0.8μm or more. The film thickness of the λ/4 phase difference layer can be measured using an elliptical polarizer or a contact film thickness meter.

(vertically aligned liquid crystal hardened layer)

The vertical alignment liquid crystal curing layer 6 is a layer composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound in a state of being aligned in a vertical direction relative to the plane of the liquid crystal curing layer. The three-dimensional refractive index ellipse formed by the vertical alignment liquid crystal curing layer 6 may have biaxiality, but preferably has uniaxiality. The vertical alignment liquid crystal curing layer 6 is a vertical alignment liquid crystal curing layer composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound in a state of being aligned in a vertical direction relative to the plane of the vertical alignment liquid crystal curing layer 6. The vertical alignment liquid crystal curing layer 6 is preferably a rod-shaped liquid crystal, and is preferably a positive C plate.

In the case where the vertically aligned liquid crystal curing layer 6 is a positive C plate, the vertically aligned liquid crystal curing layer 6 preferably has the following relationship in the range of wavelength λ=400 to 700nm in the refractive index ellipse formed by the vertically aligned liquid crystal curing layer 6,

nzV(λ)>nxV(λ)≒nyV(λ)

[In the formula, nzV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer in the direction perpendicular to the plane of the liquid crystal curing layer for light with a wavelength of λ(nm). nxV(λ) represents the maximum refractive index of the refractive index ellipse formed by the liquid crystal curing layer in the direction parallel to the plane of the liquid crystal curing layer. nyV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer in the direction parallel to the plane of the liquid crystal curing layer and orthogonal to the direction of nxV. However, in the case of nxV(λ)=nyV(λ), nxV(λ) represents the refractive index in any direction parallel to the plane of the liquid crystal curing layer]; and the following relationships of formulas (4) to (6) are satisfied;

RthV(450)/RthV(550)≦1.00 (4)

1.00≦RthV(650)/RthV(550) (5)

-120nm≦RthV(550)≦-50nm (6)

[In the formula, RthV(450) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=450nm, RthV(550) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=550nm, RthV(650) represents the phase difference value in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=650nm, and the phase difference value RthV(λ) in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ(nm) is

RthV(λ)=[(nxV(λ)+nyV(λ))/2-nzV(λ)]×dV represents; here, in the refractive index ellipse formed by the liquid crystal curing layer, nzV(λ) represents the principal refractive index in the direction perpendicular to the plane of the liquid crystal curing layer at a wavelength of λ(nm), "(nxV(λ)+nyV(λ))/2" represents the average refractive index in the plane of the liquid crystal curing layer at a wavelength of λ(nm); dV represents the thickness of the liquid crystal curing layer].

When the phase difference value RthV(550) in the thickness direction of the vertical alignment liquid crystal curing layer 6 exceeds the range of formula (6), the hue of the display including the elliptical polarizer in the oblique direction may become red or blue. The more preferable range of the phase difference value in the thickness direction is -95nm≦RthV(550)≦-55nm, and the more preferable range is -90nm≦RthV(550)≦-60nm. When "RthV(450)/RthV(550)" of the vertical alignment liquid crystal curing layer exceeds 1.0, the elliptical rate of the elliptical polarizer including the vertical alignment curing layer when viewed from an oblique direction on the short wavelength side deteriorates. When the ellipticity of the circular polarizer on the short wavelength side deteriorates and becomes smaller than 1.0, the function of the circular polarizer on the short wavelength side is impaired. The "RthV(450)/RthV(550)" is preferably 0.75 to 0.92, more preferably 0.77 to 0.87, and even more preferably 0.79 to 0.85.

The phase difference value in the thickness direction of the vertically aligned liquid crystal curing layer 6 can be adjusted according to the thickness dV of the vertically aligned liquid crystal curing layer. The phase difference value in the thickness direction is determined by the above formula RthV(λ)=[(nxV(λ)+nyV(λ))/2-nzV(λ)]×dV. Therefore, to obtain the desired phase difference value in the thickness direction (RthV(λ): the phase difference value in the thickness direction of the vertically aligned liquid crystal curing layer 6 at wavelength λ(nm)), the 3D refractive index and the film thickness dV can be adjusted. Furthermore, the 3D refractive index depends on the molecular structure and alignment state of the polymerizable liquid crystal compound described later.

From the perspective of thin film, the upper limit of the film thickness of the vertically aligned liquid crystal curing layer 6 is preferably 3 μm or less, more preferably 2.5 μm or less, still more preferably 2.0 μm or less, and particularly preferably 1.5 μm or less. Moreover, the lower limit of the film thickness of the vertically aligned liquid crystal curing layer 6 is preferably 0.1 μm or more, more preferably 0.3 μm or more, and still more preferably 0.5 μm or more. The film thickness of the vertically aligned liquid crystal curing layer can be measured using an elliptical polarizer or a contact film thickness meter.

(Polymerizable liquid crystal composition)

The λ/4 phase difference layer 4 and the vertical alignment liquid crystal curing layer 6 are preferably respectively composed of polymers of a polymerizable liquid crystal composition including a polymerizable liquid crystal compound in an alignment state. The polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable functional group (especially a photopolymerizable functional group). The so-called photopolymerizable functional group refers to a group that can participate in a polymerization reaction through active free radicals, acids, etc. generated from a photopolymerization initiator. Examples of the photopolymerizable functional group include vinyl, vinyloxy, 1-vinyl chloride, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, ethylene oxide, cyclobutylene oxide, etc. Among them, acryloxy, methacryloxy, vinyloxy, ethylene oxide and cyclobutylene oxide are preferred, and acryloxy is more preferred. Liquid crystal properties can be thermotropic or lyotropic. In terms of phase-ordered structure, it can be nematic or smectic.

In the present invention, from the perspective of exhibiting reverse wavelength dispersion, preferably from the perspective of satisfying the relationship between the aforementioned formulas (1) and (2) or (4) and (5), the polymerizable liquid crystal compound is preferably the following formula (I)

表示的化合物。

Represents the compound.

In formula (I), Ar represents a divalent aromatic group which may have a substituent. Here, the so-called aromatic group refers to a group having a planar cyclic structure, and the number of π electrons possessed by the cyclic structure is [4n+2] according to the Huckel law. Here, n represents an integer. In the case of containing heteroatoms such as -N= and -S- and forming a cyclic structure, the case where the non-covalent electron pairs on the heteroatoms satisfy the Huckel law and have aromaticity is also included. The divalent aromatic group preferably contains at least one of nitrogen atoms, oxygen atoms, and sulfur atoms.

^G1 and ^G2 each independently represent a divalent aromatic group or a divalent alicyclic alkyl group. Here, the hydrogen atom contained in the divalent aromatic group or the divalent alicyclic alkyl group may be substituted by a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic alkyl group may be substituted by an oxygen atom, a sulfur atom or a nitrogen atom.

L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.

k and l represent integers from 0 to 3 independently and satisfy the relationship 1≦k+1. Here, in the case of 2≦k+1, ^B1 and ^B2 , ^G1 and ^G2 may be the same as or different from each other.

^E1 and ^E2 each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein the hydrogen atom contained in the alkanediyl group may be substituted by a halogen atom, and the _-CH2- contained in the alkanediyl group may be substituted by -O-, -S-, or -Si-. ^P1 and ^P2 each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

^G1 and ^G2 are each independently preferably 1,4-phenylenediyl which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, 1,4-cyclohexanediyl which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably 1,4-phenylenediyl substituted with methyl, unsubstituted 1,4-phenylenediyl or unsubstituted 1,4-trans-cyclohexanediyl, particularly preferably unsubstituted 1,4-phenylenediyl or unsubstituted 1,4-trans-cyclohexanediyl. Furthermore, it is preferred that at least one of a plurality of ^G1 and ^G2 is a divalent alicyclic hydrocarbon group, and it is more preferred that at least one of ^G1 and ^G2 bonded to ^L1 or ^L2 is a divalent alicyclic hydrocarbon group.

^L1 and ^L2 are each independently preferably a ^single bond, an alkylene group ^having 1 to 4 carbon atoms, -O- ^, -S-, -Ra1ORa2-, -Ra3COORa4-, -Ra5OCORa6-, Ra7OC=OORa8-, -N=N-, ^-CRc = ^CRd- , or ^-C≡C- . Here, ^Ra1 to ^Ra8 are each independently a single bond or an alkylene group having 1 ^to 4 carbon atoms, ^{and Rc} and ^Rd are ^{each an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L1 and L2 are} each independently more preferably a single bond, ^-ORa2-1- , _-CH2- ^, _-CH2CH2- , _-COORa4-1- , or ^-OCORa6-1- . Here, ^Ra2-1 , ^Ra4-1 , and ^Ra6-1 each independently represent a single bond, _{-CH2- ,} or _-CH2CH2- . ^L1 and ^L2 each independently represent a single bond, -O-, _-CH2CH2- , -COO-, _{-COOCH2CH2- ,} or _-OCO- .

^B1 and ^B2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -, -R ^a11 COOR ^a12 -, -R ^a13 OCOR ^a14 -, or -R ^a15 OC=OOR ^a16 -. Here, R ^a9 to R ^a16 are each independently a single bond or an alkylene group having 1 to 4 carbon atoms. ^B1 and ^B2 are each independently more preferably a single bond, -OR ^a10-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a12-1 -, or -OCOR ^a14-1- . Here, R ^a10-1 , R ^a12-1 , and R ^a14-1 are each independently a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. ^B1 and ^B2 are each independently and more preferably a single _{bond, -O-, -CH2CH2- , -COO- , -COOCH2CH2-} , -OCO- or _-OCOCH2CH2- .

From the perspective of showing anti-wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, k+l=4 is better, and k=2 and l=2 are even better. When k=2 and l=2, it is even better because it becomes a symmetrical structure.

^E1 and ^E2 are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

Examples of the polymerizable group represented by ^P1 or ^P2 include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloxy group, a methacryloxy group, an oxirane group, and an oxirane group. Among these, an acryloxy group, a methacryloxy group, a vinyloxy group, an oxirane group, and an oxirane group are preferred, and an acryloxy group is more preferred.

環、嘧啶環、三唑環、三

環、吡咯啉環、咪唑環、吡唑環、噻唑環、苯並噻唑環、噻吩並噻唑環、

唑環、苯並

唑環及啡啉(phenanthroline)環等。該等之中，較佳為具有噻唑環、苯並噻唑環或苯並呋喃環，更佳為具有苯並噻唑環。而且，於Ar包含氮原子的情況，該氮原子較佳具 有π電子。 Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-attracting group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and the like, preferably a benzene ring or a naphthalene ring. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyridine ring, and a pyridine ring.

Ring, pyrimidine ring, triazole ring, tri

ring, pyrroline ring, imidazole ring, pyrazole ring, thiazole ring, benzothiazole ring, thienothiazole ring,

Azole, benzo

Among them, it is preferably a thiazole ring, a benzothiazole ring or a benzofuran ring, and more preferably a benzothiazole ring. Furthermore, when Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

In formula (I), the total number _Nx of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, further preferably 14 or more, and particularly preferably 16 or more. Also, it is preferably 30 or less, more preferably 26 or less, and further preferably 24 or less.

The aromatic group represented by Ar can be exemplified by the following groups.

In formulae (Ar-1) to (Ar-22), the * symbol represents a linking portion, and ^Z0 , ^Z1 , and ^Z2 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylaminesulfonyl group having 1 to 12 carbon atoms, or an N,N-dialkylaminesulfonyl group having 2 to 12 carbon atoms.

^Q1 and ^Q2 each independently represent ^-CR2'R3'- , ^-S- , -NH-, ^-NR2'- , -CO- or -O-, and R2 ^' and R3 ^' each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

^J1 and ^J2 each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an aromatic alkyl group or an aromatic heterocyclic group which may be substituted.

^W1 and ^W2 each independently represent a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer from 0 to 6.

Examples of the aromatic alkyl group in Y ¹ , Y ² and Y ³ include phenyl, naphthyl, anthracenyl, phenanthrenyl, biphenyl and other aromatic alkyl groups having 6 to 20 carbon atoms, preferably phenyl and naphthyl, and more preferably phenyl. Examples of the aromatic heterocyclic group include furanyl, pyrrolyl, thienyl, pyridyl, thiazolyl, benzothiazolyl and other aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom and the like, preferably furanyl, thienyl, pyridyl, thiazolyl, benzothiazolyl.

^Y1 and ^Y2 may be independently substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups. Polycyclic aromatic hydrocarbon groups refer to condensed polycyclic aromatic hydrocarbon groups or groups derived from bicyclic aromatic rings. Polycyclic aromatic heterocyclic groups refer to condensed polycyclic aromatic heterocyclic groups or groups derived from bicyclic aromatic heterocyclic rings.

^Z0 , ^Z1 and ^Z2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms. ^Z0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group. ^Z1 and ^Z2 are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

^Q1 and ^Q2 are preferably -NH-, -S-, ^-NR2'- , or -O-, and R2 ^' is preferably a hydrogen atom. Among them, -S-, -O-, or -NH- is particularly preferred.

Examples of the aromatic group represented by Ar ¹ include a group represented by the following formula (Ar-23).

In formula (Ar-23), *, Z ¹ , Z ² , Q ¹ and Q ² have the same meanings as above, and U ¹ represents a non-metal atom of Groups 14 to 16 which may be bonded to a substituent. Examples of the non-metal atom of Groups 14 to 16 include carbon atoms, nitrogen atoms, oxygen atoms and sulfur atoms, preferably =O, =S, =NR' and =C(R')R'. The substituent R' may be, for example, a hydrogen atom, a halogen atom, an alkyl group, a halogenalkyl group, an alkenyl group, an aromatic group, a cyano group, an amine group, a nitro group, a nitroso group, a carboxyl group, an alkylsulfinyl group having 1 to 6 carbon atoms, an alkylsulfonyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an N-alkylamino group having 1 to 6 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylaminesulfonyl group having 1 to 6 carbon atoms, a dialkylaminesulfonyl group having 2 to 12 carbon atoms, and the like. When the non-metal atom is a carbon atom (C), the two R's may be the same or different from each other.

Among formulas (Ar-1) to (Ar-23), formula (Ar-6) and formula (Ar-7) are preferred from the perspective of molecular stability.

環、嘧啶環、吲哚環、喹啉環、異喹啉環、嘌呤環、吡咯啶環等。該芳香族雜環基可具有取代基。而且，Y¹可與其所鍵結的氮原子及Z⁰一起為前述可被取代的多環系芳香族烴基或多環系芳香族雜環基。可舉例如苯並呋喃環、苯並噻唑環、苯並

唑環等。再者，前述式(I)所表示的化合物可例如根據日本特開2010-31223號公報記載的方法製造。 In formulae (Ar-16) to (Ar-22), ^Y1 may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and ^Z0 . Examples of the aromatic heterocyclic group include those mentioned above as the aromatic heterocyclic group that Ar may have, such as pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrrol ...

The aromatic heterocyclic group may have a substituent. Moreover, ^Y1 together with the nitrogen atom to which it is bonded and ^Z0 may be the aforementioned polycyclic aromatic alkyl group or polycyclic aromatic heterocyclic group which may be substituted. Examples thereof include benzofuran ring, benzothiazole ring, benzo

The compound represented by the above formula (I) can be produced, for example, according to the method described in Japanese Unexamined Patent Publication No. 2010-31223.

The polymerizable liquid crystal compound can be used alone or in combination of two or more. When two or more are used in combination, the content of the compound represented by the above formula (I) is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more, relative to 100 parts by mass of the polymerizable liquid crystal compound.

The polymerizable liquid crystal composition may further include additives such as solvents, photopolymerization initiators, polymerization inhibitors, photosensitizers, leveling agents, adhesion improvers, and dichroic pigments. These additives may be used alone or in combination of two or more.

For example, the content of the polymerizable liquid crystal compound is 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, and more preferably 90 to 98 parts by mass, relative to 100 parts by mass of the solid component of the polymerizable liquid crystal composition. When the content is within the above range, the orientation of the layer tends to increase. Here, the so-called solid component refers to the total amount of the components obtained by removing the solvent from the composition.

The solvent may be any solvent listed in the reinforcement layer. The content of the solvent is preferably 50 to 98 parts by mass, more preferably 70 to 95 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal composition. Therefore, the solid content in 100 parts by mass of the composition is preferably 2 to 50 parts by mass. When the solid content of the composition is less than 50 parts by mass, the viscosity of the composition becomes lower, so the thickness of the layer becomes roughly uniform, and the layer tends to be less uneven. The above solid content can be appropriately determined in consideration of the thickness of the layer to be manufactured.

The photopolymerization initiator may be the photopolymerization initiator exemplified in the reinforcement layer. The amount of the photopolymerization initiator added is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 1 to 15 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. If it is within the above range, the reaction of the polymerizable group is fully carried out and the alignment of the polymerizable liquid crystal compound is not easily disturbed.

By preparing a polymerization inhibitor, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. Examples of the polymerization inhibitor include: hydroquinone and hydroquinones having substituents such as alkyl ethers; butyl catechol and other catechols having substituents such as alkyl ethers; pyrogallols; free radical scavengers such as 2,2,6,6-tetramethyl-1-piperidinyloxy free radicals; thiophenols; β-naphthylamines and β-naphthols. In order not to disturb the alignment of the polymerizable liquid crystal compound and polymerize the polymerizable liquid crystal compound, the content of the polymerization inhibitor is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. The polymerization inhibitor can be used alone or in combination of two or more.

；紅螢烯。光敏劑可單獨使用或組合2種以上使用。相對於聚合性液晶化合物100質量份，光敏劑的含量通常為0.01至10質量份，較佳為0.05至5質量份，更佳為0.1至3質量份。 Furthermore, by using a photosensitizer, the photopolymerization initiator can be made highly sensitive. Examples of the photosensitizer include: oxanthrone, thioxanthrone and other oxanthrone; anthracene and anthracene having a substituent such as an alkyl ether;

; Rubrene. The photosensitizer can be used alone or in combination of two or more. The content of the photosensitizer is generally 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

The so-called leveling agent is an additive that has the function of adjusting the fluidity of the curable composition and making the layer obtained by coating the composition flatter. Examples include polysiloxane-based, polyacrylate-based, and perfluoroalkyl-based leveling agents such as silane coupling agents. Specifically, examples include: DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all of the above are Toray.Dow Corning Corporation); KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KB M-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE-9103, KBM-573, KBM-575, KBE-585, KBM-802, KBM-802, KBM-803, KBE-846, KBE-9007 (all of the above are made by Shin-Etsu Chemical Co., Ltd.); TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of the above are made by Momentive Performance Materials Japan LLC); Fluorinert (registered trademark) FC-72, Fluorinert FC-40, Fluorinert FC-43, Fluorinert FC-3283 (all of the above are manufactured by Sumitomo 3M Co., Ltd.); Megafac (registered trademark) R-08, Megafac R-30, Megafac R-90, Megafac F-410, Megafac F-411, Megafac F-443, Megafac F-445, Megafac F-470, Megafac F-477, Megafac F-479, Megafac F-482, Megafac F-483 (all of the above are manufactured by DIC Co., Ltd.); EFTOP (trade name) EF301, EFTOP EF303, EFTOP EF351, EFTOP EF352 (all of the above are made by Mitsubishi Materials Electronic Chemicals Co., Ltd.); SURFLON (registered trademark) S-381, SURFLON S-382, SURFLON S-383, SURFLON S-393, SURFLON SC-101, SURFLON SC-105, KH-40, SA-100 (all of the above are made by AGC Seimi Chemical Co., Ltd.); trade name E1830, trade name W5844 (made by DAIKIN Fine Chemicals Research Institute Co., Ltd.); BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all trade names: made by BM Chemie Co., Ltd.), etc. Leveling agents can be used alone or in combination of two or more.

色素、花青色素、萘色素、偶氮色素及蒽醌色素等，其中較佳為偶氮色素。偶氮色素可舉例如單偶氮色素、雙偶氮色素、三偶氮色素、四偶氮色素及二苯乙烯偶氮色素等，較佳為雙偶氮色素及三偶氮色素。二色性色素可單獨或組合，為了在可見光全部區域得到吸收，較佳為組合3種以上的二色性色素，更佳為組合3種以上的偶氮色素。 Relative to 100 parts by weight of the polymerizable liquid crystal compound, the content of the leveling agent is preferably 0.01 to 5 parts by weight, and more preferably 0.05 to 3 parts by weight. When the content of the leveling agent is within the above range, the resulting layer has a smoother tendency, so it is better. The so-called dichroic pigment refers to a pigment having the property that the absorbance of the molecule in the long axis direction is different from the absorbance in the short axis direction. The dichroic pigment is preferably one that has the property of absorbing visible light, and more preferably one that has a maximum absorption wavelength (λMAX) in the range of 380 to 680nm. Such dichroic pigments can be exemplified by acridine pigments,

Pigments, cyanine pigments, naphthalene pigments, azo pigments and anthraquinone pigments, among which azo pigments are preferred. Azo pigments include monoazo pigments, disazo pigments, triazo pigments, tetraazo pigments and stilbene azo pigments, among which disazo pigments and triazo pigments are preferred. Dichroic pigments can be used alone or in combination. In order to absorb light in the entire visible range, it is preferred to combine three or more dichroic pigments, and it is more preferred to combine three or more azo pigments.

Azo dyes include, for example, compounds represented by the following formula (II) (hereinafter sometimes referred to as "compound (II)").

T ¹ -A ¹ (-N=NA ² ) _p -N=NA ³ -T ² (II) [In formula (II), A ¹ , A ² and A ³ each independently represent a 1,4-phenylene group which may have a substituent, a naphthalene-1,4-diyl group or a divalent heterocyclic group which may have a substituent, T ¹ and T ² are electron-attracting groups or electron-releasing groups, and are located at positions substantially 180° with respect to the azo bonding plane. p represents an integer from 0 to 4. When p is 2 or more, each A ² may be the same as or different from each other. In the range showing absorption in the visible light region, the -N=N- bond may be substituted by a -C=C-, -COO-, -NHCO- or -N=CH- bond]

The optional substituents of the 1,4-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ¹ , A ² and A ³ include alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl and butyl groups; alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy and butoxy groups; fluoroalkyl groups having 1 to 4 carbon atoms such as trifluoromethyl groups; cyano groups; nitro groups; halogen atoms such as chlorine atoms and fluorine atoms; substituted or unsubstituted amino groups such as amino groups, diethylamino groups and pyrrolidinyl groups (the so-called substituted amino groups refer to amino groups having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or amino groups having 2 substituted alkyl groups bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms. The unsubstituted amino group is -NH ₂ ). Furthermore, examples of the alkyl groups having 1 to 6 carbon atoms include methyl, ethyl and hexyl groups. Examples of the alkanediyl group having 2 to 8 carbon atoms include ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, etc. In order to be included in a highly ordered liquid crystal structure such as a smectic liquid crystal, A ¹ , A ² and A ³ are preferably 1,4-phenylene or a divalent heterocyclic group which is unsubstituted or in which hydrogen is substituted with a methyl group or a methoxy group, and p is preferably 0 or 1. Among them, it is more preferred that p is 1 and at least two of the three structures of A ¹ , A ² and A ³ are 1,4-phenylene, in terms of both the simplicity of molecular synthesis and high performance.

唑及苯並

唑中除去2個氫原子而得的基。於A²為2價雜環基的情況，較佳係分子鍵結角度實質上成為180°的結構，具體而言，更佳係2個5員環稠合而成的苯並噻唑、苯並咪唑、苯並

唑結構。 The divalent heterocyclic group may be selected from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole,

Azoles and benzo

In the case where ^A2 is a divalent heterocyclic group, it is preferably a structure in which the molecular bonding angle is substantially 180°. Specifically, it is more preferably benzothiazole, benzimidazole, benzotriazole, etc., which are formed by condensing two 5-membered rings.

azole structure.

^T1 and ^T2 are electron-attracting groups or electron-releasing groups, preferably different structures, more preferably ^T1 is an electron-attracting group and ^T2 is an electron-releasing group or ^T1 is an electron-releasing group and ^T2 is an electron-attracting group. Specifically, ^T1 and ^T2 are preferably independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group having an alkanediyl group having 2 to 8 carbon atoms formed by two substituted alkyl groups bonded to each other, or a trifluoromethyl group. In order to be included in a highly ordered liquid crystal structure such as a lamellar liquid crystal, a structure with a smaller molecular exclusion volume is required, and therefore, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group having an alkanediyl group having 2 to 8 carbon atoms formed by two substituted alkyl groups bonded to each other are preferred.

Such azo dyes can be exemplified as follows.

In formulas (2-1) to (2-6),

^B1 to ^B20 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of the substituted amino group and the unsubstituted amino group are the same as above), a chlorine atom or a trifluoromethyl group. From the viewpoint of obtaining high polarization performance, ^B2 , ^B6 , ^B9 , ^B14 , ^B18 and ^B19 are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

n1 to n4 represent integers from 0 to 3 independently.

When n1 is greater than 2, the plurality of ^B2s may be the same or different;

When n2 is greater than 2, the plurality of ^B6 may be the same or different;

When n3 is 2 or more, the plurality of ^B9 may be the same or different;

When n4 is 2 or more, the plurality of B ¹⁴ may be the same or different.

The aforementioned anthraquinone pigment is preferably a compound represented by formula (2-7).

[In formula (2-7), ^R1 to ^R8 each independently represent a hydrogen atom, ^-Rx , _-NH2 , ^-NHRx , ^{-NRx2 , -SRx} _or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aromatic group having 6 to 12 carbon atoms]

色素較佳為式(2-8)所表示的化合物。 aforementioned

The pigment is preferably a compound represented by formula (2-8).

[In formula (2-8), R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aromatic group having 6 to 12 carbon atoms]

The aforementioned acridine dye is preferably a compound represented by formula (2-9).

[In formula (2-9),

R ¹⁶ to R ²³ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aromatic group having 6 to 12 carbon atoms]

The alkyl group having 1 to 4 carbon atoms represented by R ^x in formula (2-7), formula (2-8) and formula (2-9) may be methyl, ethyl, propyl, butyl, pentyl and hexyl, and the aromatic group having 6 to 12 carbon atoms may be phenyl, tolyl and xylyl.

The aforementioned anthocyanin pigment is preferably a compound represented by formula (2-10) and a compound represented by formula (2-11).

[In formula (2-10),

^D1 and ^D2 each independently represent a group represented by any one of Formula (2-10a) to Formula (2-10d).

n5 represents an integer from 1 to 3]

[In formula (2-11),

^D3 and ^D4 each independently represent a group represented by any one of Formula (2-11a) to Formula (2-11h).

n6 represents an integer from 1 to 3]

From the perspective of obtaining good light absorption characteristics, the content of the dichroic dye (the total amount if multiple types are included) is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 3 to 15 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the dichroic dye is less than this range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained. When it is more than this range, the alignment of the liquid crystal molecules may be hindered.

The polymerizable liquid crystal composition can be obtained by stirring the polymerizable liquid crystal compound and the components other than the polymerizable liquid crystal compound such as the additive at a predetermined temperature.

The λ/4 phase difference layer 4 and the vertical alignment liquid crystal curing layer 6 are preferably formed on an alignment layer that provides alignment control. In more detail, the λ/4 phase difference layer 4 can be obtained by coating the aforementioned polymerizable liquid crystal composition on the alignment layer 5, then removing the solvent, and curing the polymerizable liquid crystal composition containing the polymerizable liquid crystal compound in the alignment state by heating and/or active energy rays. The vertical alignment liquid crystal curing layer 6 can be obtained by coating the aforementioned polymerizable liquid crystal composition on the vertical alignment layer 7, then removing the solvent, and curing the polymerizable liquid crystal composition containing the polymerizable liquid crystal compound in the alignment state by heating and/or active energy rays.

The method of coating the polymerizable liquid crystal composition on the alignment layer 5 or the vertical alignment layer 7 may be, for example, the coating method A illustrated in the item of the reinforcing layer. The method of removing the solvent may be, for example, the solvent removal method A illustrated in the item of the reinforcing layer. The active energy ray to be irradiated is appropriately selected according to the type of the polymerizable liquid crystal compound, the type of the photopolymerization initiator in the case of including the photopolymerization initiator, and the amount thereof. The active energy ray and its light source may use those illustrated in the item of the reinforcing layer. Moreover, in the case of irradiating the polymerizable liquid crystal composition with ultraviolet rays, the ultraviolet ray irradiation intensity, irradiation time, and accumulated light amount may also be used within the range illustrated in the item of the reinforcing layer. When the accumulated light amount is below the range described above, the curing of the polymerizable liquid crystal compound becomes insufficient, and the reinforcement property is insufficient. On the contrary, when the accumulated light amount is above the range described above, the elliptical polarizing plate is colored.

[Orientation layer]

The alignment layer 5 has an alignment control force that allows the polymerizable liquid crystal compound to align in a predetermined direction. For example, if the alignment layer 5 is a material that exhibits a horizontal alignment control force as the alignment control force, the polymerizable liquid crystal compound can form a horizontal alignment or a mixed alignment. If it is a material that exhibits a vertical alignment control force, the polymerizable liquid crystal compound can form a vertical alignment or a tilted alignment. Moreover, since the polymerizable liquid crystal compound contained in the vertical alignment liquid crystal hardening layer 6 forms a vertical alignment, the vertical alignment layer 7 is composed of a material that exhibits a vertical alignment control force. The alignment control force can be arbitrarily adjusted by the type, surface state, friction conditions, etc. of the alignment layer. In the case of being formed by a photoalignable polymer, it can be arbitrarily adjusted by polarized light irradiation conditions, etc. Moreover, the liquid crystal alignment can be controlled by selecting the surface tension, liquid crystal properties, and other physical properties of the polymerizable liquid crystal compound.

The alignment layer 5 or the alignment layer 7 preferably has solvent resistance so as not to be dissolved by coating of the polymerizable liquid crystal composition, and has heat resistance in the heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound.

The horizontal alignment layer that exhibits the alignment control force to align the λ/4 phase difference layer 4 in the horizontal direction can be, for example, a friction alignment layer, a photo alignment layer, and a groove alignment layer having a concave-convex pattern and multiple grooves on the surface. For example, in the case of application in a long roll film, the photo alignment layer is preferred in terms of the ease of controlling the alignment direction.

The rubbing alignment layer can usually be formed by coating a composition including an aligning polymer and a solvent (hereinafter also referred to as a rubbing alignment layer forming composition) on a substrate, removing the solvent to form a coating film, and rubbing the coating film to impart alignment control force.

唑、聚伸乙基亞胺、聚苯乙烯、聚乙烯吡咯啶酮、聚丙烯酸及聚丙烯酸酯類。該等配向性聚合物可單獨使用或組合2種以上使用。 Examples of the alignment polymer include polyamides having amide bonds, gelatins, polyamides having imide bonds and their hydrolyzates, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, poly

The aligning polymers may be used alone or in combination of two or more.

The concentration of the alignment polymer in the composition for forming the friction alignment layer can be within the range that the alignment polymer is completely dissolved in the solvent. The content of the alignment polymer is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the composition.

The composition for forming the friction alignment layer can be obtained from the market. Examples of commercially available products include SUNEVER (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), OPTOMER (registered trademark, manufactured by JSR Corporation), etc.

The solvent used may be, for example, the solvents listed in the reinforcement layer. The method for coating the friction alignment layer forming composition on the substrate may be, for example, the aforementioned coating method A, and the method for removing the solvent may be, for example, the aforementioned solvent removal method A.

The friction treatment method may be, for example, a method of bringing the aforementioned coated film into contact with a friction roller that is wound with a rubbing cloth and rotates. During the friction treatment, if masking is performed, multiple regions (patterns) with different orientation directions can be formed on the orientation film.

The photo-alignment layer is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (also called a photo-alignment layer forming composition) to a substrate, removing the solvent, and then irradiating with polarized light (preferably polarized UV). The photo-alignment layer can arbitrarily control the direction of the alignment control force by selecting the polarization direction of the irradiated polarized light.

The so-called photoreactive group refers to a group that generates alignment ability by light irradiation. Specifically, it can be a group that participates in the origin of the alignment ability, such as the alignment induction reaction, isomerization reaction, photodimerization reaction, photocrosslinking reaction or photodecomposition reaction of the molecule generated by light irradiation. The photoreactive group is preferably a group having an unsaturated bond (especially a double bond), and is particularly preferably a group having at least one selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond).

基(formazan)及具有氧偶氮苯結構的基。具有C=O鍵的光反應性基可舉例如二苯甲酮基、香豆素基、蒽醌基及馬來醯亞胺基。該等基可具有烷基、烷氧基、芳香基、烯丙氧基、氰基、烷氧基羰基、羥基、磺酸基、鹵烷基等取代基。 Examples of photoreactive groups having a C=C bond include vinyl, polyene, distyryl, stilbazole, stilbazolium, chalcone, and cinnamyl. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azophenyl, azonaphthyl, aromatic heterocyclic azo, bisazo, and methyl azo.

The photoreactive group having a C=O bond may include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aromatic group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, or a halogen alkyl group.

The groups participating in the photodimerization reaction or the photocrosslinking reaction are preferred in terms of good alignment. Among them, the photoreactive groups participating in the photodimerization reaction are preferred, and the cinnamic acid group and the chalcone group are preferred in terms of the fact that the polarized light irradiation required for alignment is small and it is easy to obtain a photoalignment layer with good thermal stability and stability over time. The polymer having the photoreactive group is particularly preferred to have a cinnamic acid group that will become a cinnamic acid structure or a cinnamate structure at the end of the side chain of the polymer.

The content of the polymer or monomer having a photoreactive group can be adjusted according to the type of polymer or monomer and the thickness of the intended photo-alignment layer. It is preferably at least 0.2 parts by mass, and more preferably in the range of 0.3 to 10 parts by mass, relative to 100 parts by mass of the composition for forming the photo-alignment layer.

The solvent used may be, for example, the solvents listed in the reinforcement layer. The method for coating the photo-alignment layer-forming composition on the substrate may be, for example, the aforementioned coating method A, and the method for removing the solvent may be, for example, the aforementioned solvent removal method A.

The irradiation of polarized light may be, for example, a form of direct irradiation of polarized light obtained by removing the solvent from the composition for forming the photo-alignment layer coated on the substrate. Moreover, the polarized light is preferably substantially parallel light. The wavelength of the irradiated polarized light may be a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the range of 250 to 400 nm is particularly preferred. The light source for irradiating the polarized light may be, for example, a xenon lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halogen lamp, KrF, ArF and other ultraviolet lasers. Among them, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halogen lamps are preferred because of their high luminous intensity in ultraviolet light with a wavelength of 313nm. Polarized UV can be irradiated by passing light from the aforementioned light source through a suitable polarizing element. Examples of polarizing elements include polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire grids. Among them, wire grid-type polarizing elements are preferred from the perspective of large area and heat resistance.

Furthermore, if shielding is performed during rubbing or polarized light irradiation, multiple regions (patterns) with different liquid crystal alignment directions can be formed.

The groove alignment layer is a film with a concave-convex pattern or multiple grooves on the film surface. When a polymerizable liquid crystal compound is applied to a film with multiple linear grooves arranged at equal intervals, the liquid crystal molecules are aligned along the direction of the grooves.

Methods for obtaining the groove alignment layer include, for example, forming a concave-convex pattern by exposing a photosensitive polyimide film surface through an exposure mask having a slit in a pattern shape, developing and washing after exposure; forming a layer of a UV curable resin before curing on a plate-shaped master having grooves on the surface, transferring the formed resin layer to a substrate and curing it; and forming a concave-convex pattern by pressing a roller-shaped master having a plurality of grooves on a film of UV curable resin before curing formed on a substrate, and then curing it.

The vertical alignment layer that exhibits the alignment control force that makes the vertical alignment liquid crystal curing layer 6 align in the vertical direction is preferably made of a material that reduces the surface tension of the alignment layer surface. Such materials include, for example, the above-mentioned alignment polymers, such as polyimide, polyamide, polyamides, polyamides of their hydrolyzates, fluorine-based polymers such as perfluoroalkyl and silane compounds, and polysiloxane compounds obtained by condensation reaction. The vertical alignment layer can be obtained by coating a composition containing such a material and a solvent such as the solvent exemplified in the item of the reinforcing layer (hereinafter also referred to as a composition for forming a vertical alignment layer) on a substrate, removing the solvent, and then applying heat to the coating film.

When a silane compound is used in the vertical alignment layer, from the perspective of easily reducing surface tension and easily improving adhesion with the adjacent layer, it is preferred that at least the vertical alignment layer 7 is a layer composed of a compound containing Si and C as constituent elements, and a silane compound can be used appropriately. When at least the vertical alignment layer 7 is composed of a compound containing Si and C as constituent elements, the adhesion with the adjacent layer can be improved, and the processing characteristics of the formed elliptical polarizer can be improved.

The silane compound can be applied to the polysiloxane system such as the above-mentioned silane coupling agent, for example: vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tris(2-methoxyethoxy) silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxy silane, N-(2-aminoethyl)-3-aminopropyltrimethoxy silane, 3-aminopropyltriethoxy silane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-butylpropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane, etc.

The silane compound may be a polysiloxane monomer or a polysiloxane oligomer (polymer). When the polysiloxane oligomer is expressed in the form of a (monomer)-(monomer) copolymer, for example, copolymers containing butylpropyl groups such as 3-butylpropyltrimethoxysilane-tetramethoxysilane copolymer, 3-butylpropyltrimethoxysilane-tetraethoxysilane copolymer, 3-butylpropyltriethoxysilane-tetramethoxysilane copolymer and 3-butylpropyltriethoxysilane-tetraethoxysilane copolymer can be cited; copolymers containing methyl groups, such as methyltrimethoxysilane-tetramethoxysilane copolymers, methyltrimethoxysilane-tetraethoxysilane copolymers, methyltriethoxysilane-tetramethoxysilane copolymers, and methyltriethoxysilane-tetraethoxysilane copolymers; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymers, 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymers; 3-Methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-Methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-Methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-Methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-Methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer Copolymers containing methacryloyloxypropyl such as acryloyloxypropyl methyldiethoxysilane-tetramethoxysilane copolymer and 3-methacryloyloxypropyl methyldiethoxysilane-tetraethoxysilane copolymer; 3-acryloyloxypropyl trimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyl trimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyl triethoxysilane 3-acryloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer and 3-acryloxypropylmethyldiethoxysilane Silane-tetraethoxysilane copolymers and other copolymers containing acryloxypropyl; vinyl trimethoxysilane-tetramethoxysilane copolymers, vinyl trimethoxysilane-tetraethoxysilane copolymers, vinyl triethoxysilane-tetramethoxysilane copolymers, vinyl triethoxysilane-tetraethoxysilane copolymers, vinyl methyl dimethoxysilane-tetramethoxysilane copolymers, vinyl methyl Copolymers containing vinyl groups such as dimethoxysilane-tetraethoxysilane copolymers, vinylmethyldiethoxysilane-tetramethoxysilane copolymers and vinylmethyldiethoxysilane-tetraethoxysilane copolymers; 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymers, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymers, 3-aminopropyltriethoxysilane-tetramethoxysilane Copolymers containing amino groups, such as 3-aminopropyltriethoxysilane-tetraethoxysilane copolymers, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymers, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymers, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymers, and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymers. Silane compounds can be used alone or in combination of two or more. In addition, in the case of using it as a leveling agent, a silane coupling agent can also be used.

Among them, silane compounds having an alkyl group at the molecular end are preferred, and silane compounds having an alkyl group with 3 to 30 carbon atoms are more preferred.

In a preferred embodiment of the present invention, a vertical alignment layer 7 having a film thickness of 5 μm or less is provided between the vertical alignment liquid crystal curing layer 6 and the reinforcing layer 8. The vertical alignment layer 7 is a layer composed of a compound containing Si, C and O as constituent elements. From the viewpoint of improving the adhesion with the adjacent layer and the coating property of the composition for forming the vertical alignment liquid crystal curing layer 6, the vertical alignment layer 7 is preferably composed of a compound containing Si, C and O as constituent elements, and a silane compound can be suitably used. The substituent containing a C atom bonded to a Si atom of the silane compound forming the vertical alignment layer 7 is preferably an alkyl group or an alkoxy group, and the number of carbon atoms is preferably 1 to 30, more preferably 2 to 25, and even more preferably 3 to 20. That is, the ratio of Si element to C element (Si/C, molar ratio) is preferably 0.03 to 1.00, more preferably 0.04 to 0.50, and even more preferably 0.05 to 0.33. When the Si/C ratio is above the lower limit, the coating property of the composition for forming the vertically aligned liquid crystal curing layer 6 is improved, and when the Si/C ratio is below the upper limit, the adhesion with the adjacent layer can be improved.

The solvent used may be, for example, the solvent exemplified in the item of the reinforcing layer 8. The method of coating the vertical alignment layer forming composition on the substrate may be, for example, the aforementioned coating method A, and the method of removing the solvent may be, for example, the aforementioned solvent removal method A.

The composition for forming the alignment layer, i.e., the horizontal alignment layer forming composition such as the aforementioned rubbing alignment layer forming composition, the aforementioned optical alignment layer forming composition, and the aforementioned vertical alignment layer forming composition, may contain, in addition to the solvent, additives such as the same additives contained in the polymerizable liquid crystal composition.

From the perspective of thin film, the film thickness of the alignment layer 5 and the vertical alignment layer 7 is preferably less than 1 μm, more preferably less than 0.5 μm, and more preferably less than 0.3 μm. Moreover, the film thickness of the alignment layer 5 and the vertical alignment layer 7 is preferably more than 1 nm, more preferably more than 5 nm, more preferably more than 10 nm, and particularly preferably more than 30 nm. The film thickness of the alignment layer 5 and the vertical alignment layer 7 can be measured using an elliptical polarizer or a contact film thickness meter.

[Adhesive]

Adhesives include pressure-sensitive adhesives, dry-curing adhesives, and chemical reaction adhesives. Chemical reaction adhesives include active energy ray-curing adhesives.

Pressure-sensitive adhesives usually contain polymers and may also contain solvents. Examples of polymers include acrylic polymers, silicone polymers, polyesters, polyurethanes, or polyethers. Among them, acrylic adhesives containing acrylic polymers are preferred because they have good optical transparency, appropriate wettability, cohesiveness, good adhesion, high weather resistance, and heat resistance, and are not prone to floating or peeling under heating or humidification conditions.

The acrylic polymer is preferably a copolymer of a (meth)acrylate ester in which the alkyl group of the ester part is an alkyl group with 1 to 20 carbon atoms such as methyl, ethyl or butyl, and a (meth)acrylic monomer having a functional group such as (meth)acrylic acid or hydroxyethyl (meth)acrylate.

The pressure-sensitive adhesive containing such a copolymer is preferred because it has good adhesion and can be easily removed without producing adhesive residues on the transfer body even when it is removed after being attached to the transfer body. The glass transition temperature of the acrylic polymer is preferably below 25°C, more preferably below 0°C. The mass average molecular weight of such an acrylic polymer is preferably above 100,000.

Solvents include, for example, the solvents listed as the above-mentioned solvents. The pressure-sensitive adhesive may contain a light diffuser. The light diffuser is an additive that imparts light diffusion to the adhesive, and may be microparticles having a refractive index different from that of the polymer contained in the adhesive. Examples of light diffusers include microparticles composed of inorganic compounds and microparticles composed of organic compounds (polymers). Most polymers contained in adhesives as active ingredients, including acrylic polymers, have a refractive index of about 1.4 to 1.6, so it is better to appropriately select from light diffusers with a refractive index of 1.2 to 1.8. The difference in refractive index between the polymer and the light diffuser contained in the adhesive as an active ingredient is usually 0.01 or more, and preferably 0.01 to 0.2 from the perspective of the brightness and display performance of the display device. The microparticles used as the light diffuser are preferably spherical microparticles and nearly monodispersed microparticles, and more preferably microparticles with an average particle size of 2 to 6μm. The refractive index is measured by the general minimum deviation angle method or Abbe refractometer.

Examples of microparticles made of inorganic compounds include aluminum oxide (refractive index 1.76) and silicon oxide (refractive index 1.45). Examples of microparticles made of organic compounds (polymers) include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate/styrene copolymer resin beads (refractive index 1.50 to 1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46), and polysilicone resin beads (refractive index 1.46). The content of the light diffuser is usually 3 to 30 parts by mass relative to 100 parts by mass of the polymer.

The thickness of the pressure-sensitive adhesive is determined by its adhesion, etc., so there is no special restriction, and it is usually 1μm to 40μm. From the perspective of processability, durability, etc., the thickness is preferably 3μm to 25μm, and more preferably 5μm to 20μm. By setting the thickness of the adhesive layer formed by the adhesive to 5μm to 20μm, the brightness of the display device when viewed from the front and from an oblique direction can be maintained, and it is not easy to cause bleeding and blurring of the displayed image.

Dry curing adhesives may contain solvents. Examples of dry curing adhesives include polymers or amine resins containing monomers having protic functional groups such as hydroxyl, carboxyl or amine groups and ethylenically unsaturated groups as main components, and compositions containing crosslinking agents or curing compounds such as polyaldehydes, epoxy compounds, epoxy resins, melamine compounds, zirconium oxide compounds and zinc compounds. Examples of polymers containing monomers having protic functional groups such as hydroxyl, carboxyl or amine groups and ethylenically unsaturated groups include ethylene-maleic acid copolymers, itaconic acid copolymers, acrylic acid copolymers, acrylamide copolymers, saponified polyvinyl acetate, and polyvinyl alcohol resins.

Polyvinyl alcohol resins include polyvinyl alcohol, partially saponified polyvinyl alcohol, completely saponified polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, acetylacetyl-modified polyvinyl alcohol, hydroxymethyl-modified polyvinyl alcohol, and amino-modified polyvinyl alcohol. The content of polyvinyl alcohol resin in water-based adhesives is usually 1 to 10 parts by mass, preferably 1 to 5 parts by mass, relative to 100 parts by mass of water.

Examples of amine resins include polyester-based ionomer amine resins. Here, the polyester-based ionomer amine resin refers to an amine resin having a polyester skeleton and into which a small amount of ionic components (hydrophilic components) are introduced. Such ionomer amine resins do not use emulsifiers and are emulsified in water to form latex, so they can be used as water-based adhesives. When using polyester-based ionomer amine resins, it is effective to prepare a water-soluble epoxy compound as a crosslinking agent.

Examples of epoxy resins include polyamide polyamines obtained by reacting polyalkylene polyamines such as diethylenetriamine or triethylenetetramine with dicarboxylic acids such as adipic acid, and polyamide epoxy resins obtained by reacting with epichlorohydrin. Examples of commercially available polyamide epoxy resins include "Sumirez resin (registered trademark) 650" and "Sumirez resin 675" (produced by Sumika Chemtex Co., Ltd.), "WS-525" (produced by Japan PMC Co., Ltd.), etc. When preparing epoxy resins, the amount of epoxy resin added is usually 1 to 100 parts by mass, preferably 1 to 50 parts by mass, relative to 100 parts by mass of polyvinyl alcohol resin.

The thickness of the adhesive layer formed by the dry curing adhesive is usually 0.001 to 5μm, preferably 0.01 to 2μm, and more preferably 0.01 to 0.5μm. When the thickness of the adhesive layer formed by the dry curing adhesive is too thick, it is easy to become poor in appearance.

Active energy ray-curable adhesives may contain solvents. The so-called active energy ray-curable adhesives refer to adhesives that are cured by irradiation with active energy rays. Examples of active energy ray-curable adhesives include cationic polymerizable adhesives containing epoxy compounds and cationic polymerization initiators, free radical polymerizable adhesives containing acrylic curing components and free radical polymerization initiators, adhesives containing both cationic polymerizable curing components such as epoxy compounds and free radical polymerizable curing components such as acrylic compounds and further containing cationic polymerization initiators and free radical polymerization initiators, and adhesives that do not contain these polymerization initiators and are cured by irradiation with electron beams, etc.

Among them, preferred are free radical polymerizable active energy ray-curable adhesives containing acrylic curing components and photo-radical polymerization initiators, and cationic polymerizable active energy ray-curable adhesives containing epoxy compounds and photo-cationic polymerization initiators. Examples of acrylic curing components include (meth)acrylates such as methyl (meth)acrylate and hydroxyethyl (meth)acrylate, and (meth)acrylic acid. Active energy ray-curable adhesives containing epoxy compounds may further contain compounds other than epoxy compounds. Examples of compounds other than epoxy compounds include cyclohexane compounds and acrylic compounds.

The photoradical polymerization initiator and the photocationic polymerization initiator may be, for example, the photoradical polymerization initiator and the photocationic polymerization initiator mentioned above. The content of the radical polymerization initiator and the cationic polymerization initiator is usually 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass, relative to 100 parts by mass of the active energy ray-curable adhesive.

Active energy ray-curing adhesives may contain ion scavengers, antioxidants, chain transfer agents, adhesion promoters, thermoplastic resins, fillers, flow regulators, plasticizers, and defoaming agents.

In this specification, the so-called active energy rays are defined as energy rays that can decompose compounds that can produce active species to produce active species. Such active energy rays can be exemplified by visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays and electron beams, preferably ultraviolet rays and electron beams. The preferred ultraviolet irradiation conditions are the same as those for the polymerization of the aforementioned polymerizable liquid crystal compound.

[Elliptical polarizing plate]

The elliptical polarizing plates 1, 10 and 100 of the present invention have a layer distance of less than 5 μm between the vertically aligned liquid crystal curing layer 6 and the reinforcing layer 8, so the vertically aligned liquid crystal curing layer 6 of the film is fully reinforced, which can suppress or prevent defects such as wavy undulations on the cut end surface. Therefore, they can be applied to display applications.

In the elliptical polarizer of the present invention, the reinforcing layer 8, the alignment layer 5 and the vertical alignment layer 7 are preferably layers having isotropy (also called isotropic) of three-dimensional refractive index.

The film thickness of the elliptical polarizing plates 1, 10 and 100 of the present invention is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 30 to 100 μm. When the film thickness of the elliptical polarizing plate is above the above lower limit, it is advantageous from the perspective of processing characteristics, and when the film thickness of the elliptical polarizing plate is below the above upper limit, it is advantageous from the perspective of thin filmization.

The elliptical polarizing plates 1, 10 and 100 of the present invention preferably have an in-plane average refractive index difference of 0.20 or less at a wavelength of 550 nm in each adjacent layer. When the in-plane average refractive index difference is below the above upper limit, the reflection at the interface between the layers becomes smaller. Furthermore, the in-plane average refractive index can be measured according to the method described in the embodiment.

[Manufacturing method of elliptical polarizing plate]

The elliptical polarizing plate 1 shown in FIG. 1 can be obtained by separately forming a laminate A of a polarizing layer 2, a λ/4 phase difference layer 4 and an alignment layer 5, and a laminate B of a vertical alignment liquid crystal curing layer 6, a vertical alignment layer 7 and a reinforcing layer 8, and then bonding them together via an adhesive layer 3. For example, a laminate A is formed on a substrate, wherein an alignment layer 5 and a λ/4 phase difference layer 4 are sequentially stacked, and a laminate B is formed on a substrate, wherein a reinforcing layer 8, a vertical alignment layer 7 and a vertical alignment liquid crystal curing layer 6 are sequentially stacked. A polarizing layer 2 is attached to the λ/4 phase difference layer 4 side of the laminate A via an adhesive layer 3 so that the absorption axis of the polarizing layer 2 and the slow axis of the λ/4 phase difference layer 4 form an angle of 45°. Only the substrate is peeled off to produce a laminate C. Then, the alignment layer 5 side of the laminate C is bonded to the vertical alignment liquid crystal curing layer 6 side of the laminate B via the adhesive layer 3, and only the substrate is peeled off, thereby manufacturing the elliptical polarizing plate 1.

The elliptical polarizing plate 10 shown in FIG. 2 can be manufactured by separately manufacturing the polarizing layer 2, the aforementioned laminate A, and the aforementioned laminate B, and bonding the polarizing layer 2 to the vertically aligned liquid crystal curing layer 6 side of the laminate B through the adhesive layer 3, and only peeling off the substrate to manufacture the laminate D. Then, the reinforcing layer 8 side of the laminate D can be bonded to the λ/4 phase difference layer 4 side of the laminate A through the adhesive layer 3 so that the absorption axis of the polarizing layer 2 is substantially 45° relative to the slow axis (optical axis) of the λ/4 phase difference layer 4, and only peeling off the substrate to manufacture.

The elliptical polarizing plate 100 shown in FIG. 3 can be manufactured by separately manufacturing the polarizing layer 2, the aforementioned laminate A, and the aforementioned laminate B, bonding the λ/4 phase difference layer 4 side of the laminate A to the vertically aligned liquid crystal curing layer 6 side of the laminate B via the adhesive layer 3, and peeling off the substrates of both to manufacture the laminate E. Then, the reinforcing layer 8 side of the laminate E is bonded to the polarizing layer 2 via the adhesive layer 3 so that the absorption axis of the polarizing layer 2 is substantially 45° relative to the slow axis (optical axis) of the λ/4 phase difference layer 4.

(Base material)

The substrate may be, for example, a glass substrate or a film substrate. From the viewpoint of processability, a film substrate is preferred, and from the viewpoint of continuous production, a long roll film is more preferred. The resin constituting the film substrate may be, for example, polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide and polyphenylene ether. The bonding surface of the substrate with the adhesive layer may be subjected to a plasma treatment such as a polysilicone treatment. Commercially available cellulose ester substrates include, for example, "FUJITAC FILM" (manufactured by FUJIFILM Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (manufactured by Konica Minolta Optical Co., Ltd.). Such resins can be made into films by known means such as solvent casting and melt extrusion to form substrates.

Examples of commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona Corporation (sole proprietorship)), "ARTON" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by ZEON Corporation) and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Commercially available cyclic olefin resin substrates may be used. Examples of commercially available cyclic olefin resin substrates include "Escena" (registered trademark), "SCA40" (registered trademark) (both manufactured by Sekisui Chemical Industries, Ltd.), "ZEONOR FILM" (registered trademark) (manufactured by OPTES Co., Ltd.), and "ARTON FILM" (registered trademark) (manufactured by JSR Co., Ltd.).

The substrate preferably has a thickness that is easy to stack and peel. The thickness of such a substrate is usually 5 to 300 μm, preferably 10 to 150 μm.

[Other forms of elliptical polarizing plates]

Although the elliptical polarizers 1, 10 and 100 shown in Figures 1 to 3 include an adhesive layer 3, an alignment layer 5 and a vertical alignment layer 7, the elliptical polarizer of the present invention only needs to have a polarizing layer, a λ/4 phase difference layer, a vertical alignment liquid crystal curing layer and a reinforcing layer, and may also include layers other than these, such as other alignment liquid crystal curing layers, protective layers, etc.

Other oriented liquid crystal curing layers include the positive A plate, positive C plate, negative A plate, negative C plate, etc. listed in the λ/4 phase difference layer.

In a preferred embodiment, the other oriented liquid crystal curing layer has the optical properties represented by formula (6), preferably the optical properties represented by formula (6-1). The in-plane phase difference value Re(550) can be adjusted by the same method as the in-plane phase difference value adjustment method of the above-mentioned λ/4 phase difference layer.

200nm<Re(550)<320nm (6)

265nm<Re(550)<285nm (6-1)

Furthermore, the Re(450)/Re(550) of other oriented liquid crystal curing layers can be greater than 1.00 or less than 1.00. From the perspective of increasing the elliptical ratio of the elliptical polarizing plate, the closer the ReQ(450)/ReQ(550) of the λ/4 phase difference layer 4, the better. For Re(650)/Re(550), the value closer to the ReQ(650)/ReQ(550) of the λ/4 phase difference layer 4 is also better.

The film thickness of other oriented liquid crystal curing layers is preferably 0.5μm to 5.0μm, more preferably 2.0μm to 4.5μm.

The protective layer is preferably formed by the following protective layer forming composition, which usually contains acrylic oligomers or polymers composed of multifunctional acrylates (methacrylates), amine acrylates, polyester acrylates, epoxy acrylates, etc., polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl pyrrolidone, starches, methyl cellulose, carboxymethyl cellulose, sodium alginate and other water-soluble polymers and solvents.

The solvent contained in the composition for forming the protective layer may be, for example, the same solvent as the solvent exemplified in the item of the polymerizable liquid crystal composition, wherein at least one solvent selected from the group consisting of water, alcohol solvents and ether solvents is preferred in terms of not dissolving the layer forming the protective layer. Alcohol solvents may be, for example, methanol, ethanol, butanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether. Ether solvents may be, for example, ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Among them, ethanol, isopropanol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferred.

The film thickness of the protective layer is 0.1μm to 10μm, preferably 0.3μm to 5.0μm.

The elliptical polarizing plate of the present invention may be formed by laminating each layer with an adhesive as shown in FIGS. 1 to 3, or may be directly laminated without an adhesive. The method of laminating each layer may be, for example, laminating each layer on a substrate, laminating the layers with an adhesive, and then peeling off the substrate; or peeling off the substrate and laminating the layers with an adhesive. Furthermore, the method of directly laminating each layer or the method of laminating the layers on the substrate may use the same method as the method of forming each layer on the substrate described above. Furthermore, before laminating the layers on the substrate and bonding the layers together via an adhesive, surface treatment such as corona treatment or plasma treatment may be performed on the surface of the substrate or the surface of each layer.

[Display device]

The elliptical polarizing plate of the present invention can be used in a display device. The so-called display device is a device having a display mechanism and including a light-emitting element or a light-emitting device as a light source. Examples of the display device include a liquid crystal display device, an organic electroluminescent (EL) display device, an inorganic electroluminescent (EL) display device, a touch panel display device, an electron emission display device (field emission display device (FED, etc.), a surface field emission display device (SED)), an electronic paper (a display device using electronic ink or an electrophoretic element), a plasma display device, a projection display device (a grating valve (GLV) display device, a display device having a digital micromirror device (DMD), etc.), and a piezoelectric ceramic display. Liquid crystal display devices include any of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection liquid crystal display device. Such display devices may be display devices that display 2D images, or may be stereoscopic display devices that display 3D images. In particular, the display device having the elliptical polarizing plate of the present invention is preferably an organic EL display device and a touch panel display device, and is particularly preferably an organic EL display device. The present invention also includes an organic EL display device having the elliptical polarizing plate of the present invention.

Preferred embodiments of the organic EL display device of the present invention include, for example, a device in which the reinforcing layer 8 of the elliptical polarizing plate shown in FIG. 1 is bonded to the organic EL panel via an adhesive, or a device in which the alignment layer 5 of the elliptical polarizing plate shown in FIG. 2 or FIG. 3 is bonded to the organic EL panel via an adhesive.

[Implementation example]

The present invention is described in more detail below through examples. In addition, "%" and "parts" in the examples refer to mass % and mass parts unless otherwise specified. In addition, the polymer films, devices and measurement methods used in the following examples are as follows.

‧The corona treatment device used is AGF-B10 manufactured by Kasuga Electric Co., Ltd.

‧Corona treatment can be appropriately carried out when the composition is applied to the substrate. Use the above-mentioned corona treatment device and perform it once under the conditions of output 0.3kW and treatment speed 3m/min.

‧The polarized UV irradiation device used was SPOT CURE SP-9 with a polarizer unit manufactured by Ushio Electric Co., Ltd.

‧The high-pressure mercury lamp used was Unicure VB-15201BY-A manufactured by Ushio Electric Co., Ltd.

‧The in-plane phase difference value Re(λ) was measured using KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd.

‧The phase difference value Rth(λ) in the thickness direction and the film thickness are measured using an elliptoscope M-220 manufactured by JASCO Corporation or a contact-type film thickness meter (MH-15M, Counter TC101, MS-5C manufactured by Nikon Corporation). In addition, the Si/C ratio is calculated by elemental analysis of the vertical alignment layer 7, measurement of surface constituent elements using X-ray photospectroscopy, or when the structural formula of the compound used in the formation of the vertical alignment layer 7 is completely known, it can be calculated from the structural formula.

(Implementation Example 1)

The elliptical polarizing plate 1 having the layer structure shown in FIG. 1 is manufactured as follows.

[Manufacturing of polarizing layer 2]

A polyvinyl alcohol film with an average degree of polymerization of about 2400, a saponification degree of more than 99.9 mol%, and a thickness of 75 μm was immersed in pure water at 30°C, and then immersed in an aqueous solution with a mass ratio of iodine/potassium iodide/water of 0.02/2/100 at 30°C for iodine dyeing (iodine dyeing step). Then, the polyvinyl alcohol film that had undergone the iodine dyeing step was immersed in an aqueous solution with a mass ratio of potassium iodide/boric acid/water of 12/5/100 at 56.5°C for boric acid treatment (boric acid treatment step). The polyvinyl alcohol film that had undergone the boric acid treatment step was washed with pure water at 8°C and dried at 65°C to obtain a polarizer with iodine adsorption oriented to polyvinyl alcohol (thickness after stretching was 27 μm). At this time, stretching is performed in the iodine dyeing step and the boric acid treatment step. The total stretching ratio of such stretching is 5.3 times. The obtained polarizer is bonded to the saponified triacetyl cellulose film (KC4UYTAC 40μm manufactured by Konica Minolta) using a clamping roller through a water-based adhesive. While maintaining the tension of the obtained bond at 430N/cm, it is dried at 60°C for 2 minutes to obtain a polarizing layer with a triacetyl cellulose film as a protective film on one side. Furthermore, the aforementioned water-based adhesive is prepared by adding 3 parts of carboxyl-modified polyvinyl alcohol (manufactured by Kuraray, "Kuraray Poval KL318") and 1.5 parts of water-soluble polyamide epoxy resin (manufactured by Sumika Chemtex, "Sumirez resin 650", an aqueous solution with a solid content concentration of 30%) to 100 parts of water.

The optical properties of the obtained polarizing layer 2 were measured. The measurement was carried out using a spectrophotometer ("V7100", manufactured by JASCO Corporation) with the surface of the polarizer of the obtained polarizing layer as the incident surface. The absorption axis of the polarizing layer was consistent with the stretching direction of polyvinyl alcohol. The visual sensitivity corrected monomer transmittance of the obtained polarizing layer was 42.1%, the visual sensitivity corrected polarization was 99.996%, the monomer hue a was -1.1, and the monomer hue b was 3.7.

[Preparation of composition (a) for forming the alignment layer 5 for forming the λ/4 phase difference layer 4]

5 parts of the photo-alignment material of the following structure (weight average molecular weight: 30000) and 95 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to obtain a composition (a) for forming an alignment layer 5 for forming a λ/4 phase difference layer 4.

[Preparation of the composition for forming the λ/4 phase difference layer 4 and the composition for forming the vertically aligned liquid crystal curing layer 6]

To the mixture of the polymerizable liquid crystal compound A and the polymerizable liquid crystal compound B shown below in a mass ratio of 90:10, 1.0 part of a leveling agent (F-556; manufactured by DIC Corporation) and 6 parts of 2-dimethylamino-2-benzyl-1-(4-morpholinylphenyl)butane-1-one ("Irgacure 369 (Irg369)", manufactured by BASF Corporation of Japan) as a polymerization initiator were added.

Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration became 13%, and the mixture was stirred at 80°C for 1 hour to obtain a composition for forming a λ/4 phase difference layer 4 and a composition for forming a vertically aligned liquid crystal curing layer 6.

The polymerizable liquid crystal compound A is produced using the method described in Japanese Patent Publication No. 2010-31223. Furthermore, the polymerizable liquid crystal compound B is produced according to the method described in Japanese Patent Publication No. 2009-173893. The molecular structures of each are shown below.

[Polymerizable liquid crystal compound A]

[Polymerizable liquid crystal compound B]

[Manufacturing of a laminate A consisting of a substrate, an alignment layer 5 and a λ/4 phase difference layer 4]

The composition for forming an alignment layer (a) was applied on a cycloolefin polymer film (COP) (ZF-14-50, 50 μm thick) manufactured by ZEON Co., Ltd. of Japan using a bar coater, dried at 80°C for 1 minute, and exposed to polarized UV light using a polarized UV irradiation device ("SPOT CURE SP-9", manufactured by Ushio Electric Co., Ltd.) at a wavelength of 313 nm and an accumulated light dose of 100 mJ/cm ² and an axis angle of 45°. The thickness of the resulting alignment layer 5 was measured using an elliptical polarizer and was 100 nm.

Then, the composition for forming the λ/4 phase difference layer 4 was applied to the alignment layer 5 using a bar coater, dried at 120°C for 1 minute, and then irradiated with ultraviolet light (in a nitrogen atmosphere, the accumulated light amount at a wavelength of 365nm: 500mJ/ ^cm2 ) using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) to form the λ/4 phase difference layer 4, thereby obtaining a laminate A composed of the substrate, the alignment layer 5, and the λ/4 phase difference layer 4. The film thickness of the λ/4 phase difference layer 4 of the laminate A was measured using an elliptical polarizer and was 2.3μm.

[Preparation of a composition (b) for forming a vertical alignment layer for forming a vertical alignment liquid crystal curing layer]

The silane coupling agent "KBE-3103" manufactured by Shin-Etsu Chemical Co., Ltd. was dissolved in a mixed solvent in which ethanol and water were mixed in a ratio of 9:1 (mass ratio) to obtain a vertical alignment layer forming composition (b) having a solid content of 0.5% for forming a vertical alignment liquid crystal curing layer.

[Preparation of a composition for forming a reinforcing layer 8 including an acrylic resin]

A reinforcing layer-forming composition containing an acrylic resin was prepared by dissolving 50 parts of dipentatriol hexaacrylate (ARONIX M-403, a multifunctional acrylate manufactured by Toagosei Co., Ltd.), 50 parts of an acrylic resin (EBECRYL 4858, manufactured by Daicel UCB Co., Ltd.), and 3 parts of 2-methyl-1-[4-(methylthio)phenyl]-2-oxolinylpropane-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals Co., Ltd.) in 250 parts of isopropyl alcohol to prepare a solution.

[Manufacturing of a laminate B consisting of a substrate, a reinforcing layer 8, an alignment layer 7 and a vertically aligned liquid crystal curing layer 6]

A reinforcing layer-forming composition containing an acrylic resin was applied to a release-treated polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Co., Ltd., hereinafter referred to as a "separator") manufactured by ZEON Co., Ltd. of Japan using a bar coater, dried at 50°C for 1 minute, and then irradiated with ultraviolet rays (in a nitrogen atmosphere, the accumulated light amount at a wavelength of 365 nm: 500 mJ/ ^cm2 ) using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) to form a reinforcing layer 8 containing an acrylic resin. The film thickness of the obtained reinforcing layer 8 was measured to be 10 μm using a contact film thickness meter. Then, the vertical alignment layer forming composition (b) was applied on the reinforcing layer 8 using a bar coater and dried at 80° C. for 1 minute to obtain the vertical alignment layer 7. The film thickness of the obtained vertical alignment layer 7 was measured using an elliptical polarizer and was found to be 50 nm.

Furthermore, a composition for forming a vertically aligned liquid crystal curable layer 6 was applied to the vertically aligned layer 7 using a bar coater, dried at 120°C for 1 minute, and then irradiated with ultraviolet rays (in a nitrogen atmosphere, the accumulated light amount at a wavelength of 365 nm: 500 mJ/cm ² ) using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) to form a vertically aligned liquid crystal curable layer 6, thereby obtaining a laminate B composed of a substrate, a reinforcing layer 8, an alignment layer 7, and a vertically aligned liquid crystal curable layer 6. The film thickness of the vertically aligned liquid crystal curable layer 6 of the laminate B was measured using an elliptical polarizer and was found to be 1.2 μm. Furthermore, the interlayer distance between the reinforcing layer 8 and the vertical alignment liquid crystal curing layer 6 is 50 nm. Furthermore, the constituent element ratio of the vertical alignment layer 7 is Si/C=0.33.

[Re measurement of λ/4 phase difference layer 4 and vertically aligned liquid crystal curing layer 6]

The in-plane phase difference values (Re1(λ) and Re2(λ)) of the λ/4 phase difference layer 4 and the vertical alignment liquid crystal curing layer 6 manufactured by the above method were measured by a measuring machine ("KOBRA-WPR", manufactured by Oji Testing Instruments Co., Ltd.) after confirming that the COP film belonging to the substrate has no phase difference. The results of measuring the phase difference value ReQ(λ) at each wavelength are ReQ(450)=119nm, ReQ(550)=140nm, ReQ(650)=146nm, and ReQ(450)/ReQ(550)=0.85.

[Measurement of Rth of Vertically Aligned Liquid Crystal Hardened Layer 6]

The thickness direction phase difference value (RthV(λ)) of the vertical alignment liquid crystal hardening layer 6 manufactured by the above method is measured by bonding the vertical alignment liquid crystal hardening layer 6 to glass via an adhesive layer 3 (pressure-sensitive adhesive 15μm manufactured by Lintec Corporation), peeling off the separator belonging to the substrate, and making a sample for measurement. After confirming that there is no phase difference between the alignment layer 7 and the reinforcing layer 8, the incident angle of light on the sample is changed by an elliptical polarizer. In addition, the average refractive index at the wavelength λ of 450nm and 550nm is measured using a refractometer ("Multi-wavelength Abbe Refractometer DR-M4" manufactured by Atago Co., Ltd.). The RthV calculated from the obtained film thickness, average refractive index and the measurement results of the elliptical polarizer are RthV(450)=-60nm, RthV(550)=-70nm, and RthV(450)/RthV(550)=0.85.

[Manufacturing of elliptical polarizing plate 1]

After the surface coated with the polymerizable liquid crystal composition of the λ/4 phase difference layer 4 of the laminate A is subjected to a corona treatment, the polarizing layer 2 manufactured as above and the λ/4 phase difference layer 4 of the laminate A are attached to each other via an adhesive layer 3 (15 μm pressure-sensitive adhesive manufactured by Lintec) so that the angle between the absorption axis of the polarizing layer 2 and the slow axis of the λ/4 phase difference layer 4 becomes 45°. Only the substrate is peeled off to produce a laminate C. Then, after the vertical alignment liquid crystal curing layer 6 of the laminate B is subjected to a corona treatment, the alignment layer 5 of the laminate C is bonded to the vertical alignment liquid crystal curing layer 6 of the laminate B via an adhesive layer 3 (pressure-sensitive adhesive 15μm manufactured by Lintec), and only the substrate is peeled off to produce an elliptical polarizing plate 1.

[Difference in in-plane average refractive index of each layer]

Each layer was coated on glass according to the above method, and the average refractive index of each layer was calculated using a refractometer ("Multi-wavelength Abbe Refractometer DR-M4" manufactured by Atago Co., Ltd.) or an elliptical polarizer, and the difference in the average refractive index within the plane of each layer was confirmed to be less than 0.2.

[Observation of the cut end surface]

Place the obtained elliptical polarizing plate on a cutting pad, cut a 3cm×3cm square with a cutter, and visually observe the end surface with a 10x magnifying glass to check whether there are defects such as undulation and cracks. Perform the same operation 3 times, and set X if a defect is observed even once, and set ○ if no defect is observed. The results are recorded in Table 1.

(Examples 2 and 3)

Except for changing the film thickness of the reinforcing layer 8 to that shown in Table 1, an elliptical polarizing plate was prepared in the same manner as in Example 1, and the cut end surface was observed.

(Implementation Example 4)

An elliptical polarizing plate was prepared in the same manner as in Example 1 except that 0.5 wt% of polyimide ("SUNEVER SE-610", manufactured by Nissan Chemical Industries, Ltd.), 72.3 wt% of N-methyl-2-pyrrolidone, 18.1 wt% of 2-butoxyethanol, 9.1 wt% of ethylcyclohexane and 0.01 wt% of DPHA (manufactured by Shin-Nakamura Chemical) were mixed to prepare a composition (b) for forming a vertical alignment layer, and the film thickness of the reinforcing layer 8 was set to 5 μm. The cut end face was observed. The results are shown in Table 1. The film thickness of the vertical alignment layer 7 was measured by an elliptical polarizer to be 0.5 μm. Accordingly, the interlayer distance between the reinforcement layer 8 and the vertically aligned liquid crystal curing layer 6 is 0.5μm.

(Example 5)

As shown below, except for changing the composition for forming the reinforcing layer 8 and the manufacturing method of the reinforcing layer 8, an elliptical polarizing plate was prepared in the same manner as in Example 1, and the cut end surface was observed. The results are shown in Table 1.

[Preparation of a composition for forming a reinforcing layer 8 including an epoxy resin]

Mix 80 parts of 3,4-epoxycyclohexanecarboxylic acid 3,4-epoxycyclohexylmethyl ester, 20 parts of 2-ethylhexyl epoxypropyl ether, 2.25 parts of CPI-100P manufactured by SAN-APRO, and 2.25 parts of propylene carbonate to prepare a composition for forming the reinforcing layer 8 containing an epoxy resin.

[Manufacturing of a laminate B consisting of a substrate, a reinforcing layer 8, an alignment layer 7 and a vertically aligned liquid crystal curing layer 6 (manufacturing of the reinforcing layer 8 only)]

On the separator subjected to release treatment, a reinforcing layer 8-forming composition containing epoxy resin was applied using a bar coater, dried at 50°C for 1 minute, and then irradiated with ultraviolet rays (in a nitrogen atmosphere, cumulative light quantity at a wavelength of 365 nm: 400 mJ/cm ² ) using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) to form a reinforcing layer 8 containing epoxy resin. The film thickness of the obtained reinforcing layer 8 was measured with a contact film thickness meter and was 5 μm.

(Implementation Example 6)

As shown below, except for changing the composition for forming the reinforcing layer 8 and the manufacturing method of the reinforcing layer 8, an elliptical polarizing plate was prepared in the same manner as in Example 1, and the cut end surface was observed. The results are shown in Table 1.

[Preparation of a composition for forming a reinforcing layer 8 including an urethane resin]

A solution was prepared by dissolving 100 parts of an acrylic resin (EBECRYL 4858, manufactured by Daicel UCB Co., Ltd.) and 3 parts of 2-methyl-1-[4-(methylthio)phenyl]-2-oxolinylpropane-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) in 250 parts of isopropyl alcohol to obtain a composition for forming a reinforcing layer 8 containing an amine resin.

[Manufacturing of a laminate B consisting of a substrate, a reinforcing layer 8, an alignment layer 7 and a vertically aligned liquid crystal curing layer 6 (manufacturing of the reinforcing layer 8 only)]

On the separator subjected to release treatment, a composition for forming a reinforcing layer 8 containing an urethane resin was applied using a bar coater, dried at 50°C for 1 minute, and then irradiated with ultraviolet rays (in a nitrogen atmosphere, the accumulated light amount at a wavelength of 365 nm: 400 mJ/cm ² ) using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) to form a reinforcing layer 8 containing an urethane resin. The film thickness of the obtained reinforcing layer 8 was measured with a contact film thickness meter and was 5 μm.

(Examples 7 to 9)

Except for changing the film thickness of the reinforcing layer 8 and changing the manufacturing method of the elliptical polarizing plate to the following, the elliptical polarizing plate 10 having the layer structure shown in FIG. 2 is manufactured in the same manner as in Example 1, and the cut end surface is observed.

[Manufacturing method of elliptical polarizing plate 10]

First, after the vertical alignment liquid crystal cured layer 6 of the laminate B is subjected to a corona treatment, the vertical alignment liquid crystal cured layer 6 of the laminate B is attached to the polarizing layer 2 obtained above via an adhesive layer 3 (15 μm pressure-sensitive adhesive manufactured by Lintec), and the substrate is peeled off to produce a laminate D. Then, after applying a corona treatment to the polymerizable liquid crystal composition coating surface of the λ/4 phase difference layer 4 of the laminate A, the reinforcing layer 8 of the laminate D and the λ/4 phase difference layer 4 of the laminate A are attached via an adhesive layer 3 (15μm pressure-sensitive adhesive manufactured by Lintec) so that the absorption axis of the polarizing layer 2 is substantially 45° relative to the slow axis (optical axis) of the λ/4 phase difference layer 4, and the substrate is peeled off to produce an elliptical polarizing plate 10.

(Examples 10 to 12)

Except for changing the film thickness of the reinforcing layer 8 and changing the manufacturing method of the elliptical polarizing plate to the following, the elliptical polarizing plate 100 having the layer structure shown in FIG. 3 is manufactured in the same manner as in Example 1, and the cut end surface is observed.

[Manufacturing method of elliptical polarizing plate 100]

First, after the λ/4 phase difference layer 4 of the laminate A and the vertically aligned liquid crystal curing layer 6 of the laminate B are subjected to coma treatment, the λ/4 phase difference layer 4 of the laminate A and the vertically aligned liquid crystal curing layer 6 of the laminate B are bonded together via an adhesive layer 3 (15μm pressure-sensitive adhesive manufactured by Lintec), and the substrate of the laminate B is peeled off to produce the laminate E. Then, the reinforcing layer 8 of the laminate E and the polarizing layer 2 are bonded together through an adhesive layer 3 (pressure-sensitive adhesive 15 μm manufactured by Lintec) so that the absorption axis of the polarizing layer 2 is substantially 45° relative to the slow axis (optical axis) of the λ/4 phase difference layer 4, and then the substrate contained in the laminate A is peeled off to produce an elliptical polarizing plate 100.

(Comparison Example 1)

Except for omitting the step of making the reinforcement layer, the elliptical polarizing plate was made in the same way as in Example 1, and the cut end surface was observed.

(Comparison Example 2)

Except for omitting the step of making the reinforcement layer, the elliptical polarizing plate was made in the same way as in Examples 7 to 9, and the cut end surface was observed.

The following shows the results of the observation of the cut end surface for the embodiment and the comparative example. In addition, in Table 1, the interlayer distance refers to the interlayer distance between the vertically aligned liquid crystal curing layer 6 and the reinforcing layer 8.

[Table 1]

The elliptical polarizing plates of Examples 1 to 12 can be processed without producing defects such as undulations and cracks during cutting, and are elliptical polarizing plates with good processing characteristics.

1: Elliptical polarizing plate

2: Polarizing layer

3: Adhesive layer

4:λ/4 phase difference layer

5: Orientation layer

6: Vertically aligned liquid crystal hardened layer

7: Vertical alignment layer

8: Reinforcement layer

Claims (9)

An elliptical polarizing plate, which sequentially comprises a polarizing layer, an adhesive layer, a λ/4 phase difference layer, an adhesive layer, a vertically aligned liquid crystal curing layer, a reinforcing layer and an adhesive layer, wherein the vertically aligned liquid crystal curing layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound that is aligned in a vertical direction relative to the plane of the liquid crystal curing layer, and the film thickness of the vertically aligned liquid crystal curing layer is less than 3μm. An elliptical polarizing plate comprises a polarizing layer, an adhesive layer, a reinforcing layer, a vertically aligned liquid crystal curing layer, an adhesive layer and a λ /4 phase difference layer in sequence, wherein the vertically aligned liquid crystal curing layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound aligned in a vertical direction relative to the plane of the liquid crystal curing layer, and the film thickness of the vertically aligned liquid crystal curing layer is less than 3 μm. An elliptical polarizing plate as described in item 1 or 2 of the patent application, wherein the interlayer distance between the vertically aligned liquid crystal curing layer and the reinforcing layer is less than 5 μm. An elliptical polarizing plate as described in item 1 or 2 of the patent application, wherein the λ/4 phase difference layer is a horizontally aligned liquid crystal curing layer, and the horizontally aligned liquid crystal curing layer is composed of a polymer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound that is aligned in a horizontal direction relative to the plane of the liquid crystal curing layer. The elliptical polarizing plate as described in item 1 or 2 of the patent application scope, wherein the reinforcing layer comprises at least one selected from the group consisting of acrylic resin, epoxy resin, cyclobutane resin, urethane resin and melamine resin. An elliptical polarizing plate as described in item 1 or 2 of the patent application, wherein the difference in the average refractive index in the plane at a wavelength of 550nm between adjacent layers is less than 0.20. An elliptical polarizing plate as described in item 1 or 2 of the patent application, wherein, with respect to the λ/4 phase difference layer, in the refractive index ellipse formed by the λ/4 phase difference layer, in the range of wavelength λ=400 to 700nm, the following relationship exists: nxQ(λ)>nyQ(λ)≒nzQ(λ) wherein nxQ(λ) represents the principal refractive index in the direction parallel to the plane of the phase difference layer for light of wavelength λ(nm) in the refractive index ellipse formed by the λ/4 phase difference layer; nyQ(λ) ReQ(450)/ReQ(550)≦1.00 (1) 1.00≦ReQ(650)/ReQ(550) (2) 100nm≦ReQ(550)≦160nm (3) In the formula, ReQ(450) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=450nm, ReQ(550) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=550nm, and ReQ(650) represents the in-plane phase difference value of the λ/4 phase difference layer for light with a wavelength of λ=650nm. The in-plane phase difference value ReQ(λ) of the λ/4 phase difference layer for light with a wavelength of λ(nm) is expressed by ReQ(λ)=(nxQ(λ)-nyQ(λ))×dQ, where dQ represents the thickness of the λ/4 phase difference layer. As described in item 1 or 2 of the patent application, the elliptical polarizer, with respect to the vertically aligned liquid crystal curing layer, has the following relationship in the range of wavelength λ=400 to 700nm in the refractive index ellipse formed by the vertically aligned liquid crystal curing layer: nzV(λ)>nxV(λ)≒nyV(λ) wherein nzV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer in a direction perpendicular to the plane of the liquid crystal curing layer for light of wavelength λ(nm); nxV(λ) represents the refractive index of the refractive index ellipse formed by the liquid crystal curing layer for light of wavelength λ(nm); nyV(λ) represents the maximum refractive index for light of wavelength λ(nm) in a direction parallel to the plane of the liquid crystal curing layer; nyV(λ) represents the refractive index for light of wavelength λ(nm) in a direction parallel to the plane of the liquid crystal curing layer and orthogonal to the direction of nxV in the refractive index ellipse formed by the liquid crystal curing layer; however, in the case of nxV(λ)=nyV(λ), nxV(λ) represents the refractive index in any direction parallel to the plane of the liquid crystal curing layer; and the following relationships (4) to (6) are satisfied: RthV(450)/RthV(550)≦1.00 (4) 1.00≦RthV(650)/RthV(550) (5) -120nm≦RthV(550)≦-50nm (6) Wherein, RthV(450) represents the phase difference in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=450nm, RthV(550) represents the phase difference in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=550nm, RthV(650) represents the phase difference in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ=650nm, and RthV(λ) represents the phase difference in the thickness direction of the liquid crystal curing layer for light with a wavelength of λ(nm). It is expressed as RthV(λ)=[(nxV(λ)+nyV(λ))/2-nzV(λ)]×dV; here, in the refractive index ellipse formed by the liquid crystal curing layer, nzV(λ) represents the principal refractive index in the direction perpendicular to the plane of the liquid crystal curing layer at a wavelength of λ(nm), "(nxV(λ)+nyV(λ))/2" represents the average refractive index in the plane of the liquid crystal curing layer at a wavelength of λ(nm); dV represents the thickness of the liquid crystal curing layer. An organic EL display device having an elliptical polarizing plate as described in any one of items 1 to 8 of the patent application scope.

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