JP7166049B2 - Elliptical polarizer - Google Patents

Description

The present invention relates to an elliptically polarizing plate. The present invention also relates to a display device having an elliptically polarizing plate and a method for manufacturing the elliptically polarizing plate.

Optical films such as polarizing plates and retardation plates are used in flat panel displays (FPDs). As such a polarizing plate, a polarizing plate comprising a protective film and a polarizing layer in which a dichroic dye such as iodine is oriented and adsorbed on a polyvinyl alcohol resin film is widely used. As a retardation plate, a retardation plate obtained by stretching a cycloolefin-based resin film, a polycarbonate-based resin film, or a triacetylcellulose-based resin film is widely known. Along with the recent trend toward thinner films, thin-film polarizing plates and retardation plates produced by coating a substrate with a composition containing a polymerizable liquid crystal compound have been developed. For example, Patent Document 1 discloses a retardation film exhibiting reverse wavelength dispersion, and Patent Document 2 discloses a polarizing layer exhibiting high polarization performance. Further, in order to further reduce the film thickness, for example, Patent Document 3 has developed a technique of forming a polarizing layer and a retardation film via a protective layer. These polarizing layer and retardation layer are often laminated together and used as an elliptically polarizing plate.

Japanese translation of PCT publication No. 2010-537955 Japanese Patent Publication No. 2013-101328 Japanese Patent Publication No. 2014-63143

However, conventional elliptically polarizing plates obtained in this manner have problems in that the polarizing layer has alignment defects and optical axis deviation. The orientation defect of the polarizing layer impairs the function as an elliptically polarizing plate at the defective portion. Further, the optical axis deviation impairs the function as an elliptically polarizing plate.
As a result of studies by the present inventors, it was found that a polarizing plate in which orientation defects and optical axis misalignment are suppressed can be provided.
An object of the present invention is to provide an elliptically polarizing plate in which orientation defects and optical axis misalignment of the polarizing layer are suppressed.

That is, the present invention provides the following [1] to [13].
[1] An elliptical polarizing plate in which an orientation layer A, a retardation layer, an orientation layer B and a polarizing layer are provided in this order on a transparent substrate,
The optical axes of the polarizing layer and the retardation layer are not in a substantially parallel relationship,
The retardation layer is a film composed of a polymer of a polymerizable liquid crystal compound,
The alignment layer B is a film having a thickness of 80 nm to 800 nm,
The polarizing layer is a film in which a dichroic dye is dispersed and aligned in a film composed of a polymer of a polymerizable liquid crystal compound.
Elliptical polarizer.
[2] The elliptically polarizing plate according to [1], wherein the average refractive indices of the transparent substrate, orientation layer A, retardation layer, orientation layer B and polarizing layer are all in the range of 1.4 to 1.7.
[3] The elliptically polarizing plate of [1] or [2], wherein the difference in refractive index between adjacent layers is 0.2 or less.
[4] The elliptically polarizing plate according to any one of [1] to [3], wherein the angle formed by the optical axes of the polarizing layer and the retardation layer is in the range of 40° to 50°.
[5] The elliptically polarizing plate according to any one of [1] to [4], wherein both the alignment layer A and the alignment layer B are photo-alignment films.
[6] The elliptically polarizing plate according to any one of [1] to [5], wherein the alignment layer A and the alignment layer B are photo-alignment films containing cinnamoyl groups.
[7] The elliptically polarizing plate according to any one of [1] to [6], wherein the alignment layer A and alignment layer B are photo-alignment films containing a resin having a weight average molecular weight of 20,000 to 50,000.
[8] The elliptically polarizing plate according to any one of [1] to [7], wherein the polarizing layer is a film composed of a polymer in a smectic liquid crystal state.
[9] The elliptically polarizing plate according to any one of [1] to [8], wherein the dichroic dye is an azo dye.
[10] The elliptically polarizing plate according to any one of [1] to [9], wherein the retardation layer satisfies all of the following formulas.
100 nm<Re(550)<160 nm (1)
Re(450)/Re(550)≤1.0 (2)
1.00≦Re(650)/Re(550) (3)
(Re(450), Re(550), and Re(650) represent in-plane retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.)
[11] A liquid crystal display device comprising the elliptically polarizing plate according to any one of [1] to [10].
[12] An organic EL display device comprising the elliptically polarizing plate according to any one of [1] to [11].
[13] On a transparent substrate,
Step (1) of applying a composition containing an alignment material A and a solvent, drying the composition, and then irradiating polarized UV to form an alignment layer A;
A step (2) of forming a retardation layer by applying a composition containing a polymerizable liquid crystal compound, a polymerization initiator, and a solvent onto the alignment layer A, drying the composition, and then irradiating it with UV to polymerize it in a liquid crystal state. When,
a step (3) of applying a composition containing an alignment material B and a solvent, drying it, and irradiating it with polarized UV to form an alignment layer B;
A polarizing layer is formed by applying a composition containing a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator, and a solvent onto the alignment layer B, drying it, and then irradiating it with UV to polymerize it in a liquid crystal state. A method for producing an elliptically polarizing plate, comprising the step (4).

According to the present invention, it is possible to provide an elliptically polarizing plate in which the optical axis shift and the occurrence of orientation defects in the retardation layer and the polarizing layer are suppressed.

Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the gist of the present invention.

The elliptically polarizing plate of the present invention is an elliptically polarizing plate in which an orientation layer A, a retardation layer, an orientation layer B, and a polarizing layer are provided in this order on a transparent substrate.

[Transparent substrate]
Examples of transparent substrates include glass substrates and film substrates. Film substrates are preferable, and long roll films are more preferable because they can be produced continuously.
Examples of resins constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; and cellulose esters such as cellulose acetate propionate; polyethylene naphthalate; polycarbonates; polysulfones; polyethersulfones; polyetherketones;
Commercially available cellulose ester substrates include "Fujitac Film" (manufactured by Fuji Photo Film Co., Ltd.);
Commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "Arton" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by Nippon Zeon Co., Ltd.) and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such a cyclic olefin resin can be used as a substrate by forming a film by a known method such as a solvent casting method or a melt extrusion method. A commercially available cyclic olefin resin base material can also be used. Examples of commercially available cyclic olefin resin substrates include "Escina" (registered trademark), "SCA40" (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), and "Zeonor Film" (registered trademark) (manufactured by Optes Co., Ltd.). ) and “Arton Film” (registered trademark) (manufactured by JSR Corporation).
As for the thickness of the base material, a thinner one is preferable in terms of practical handling, but if the base material is too thin, the strength tends to decrease and workability tends to be poor. The thickness of the substrate is usually 5 μm to 300 μm, preferably 20 μm to 200 μm.

[Orientation layer A (orientation film for forming a retardation layer)]
First, an alignment layer A is formed on the transparent substrate. The alignment layer A (or referred to as an alignment film A) is a layer having an alignment control force for aligning the polymerizable liquid crystal compound used for forming the retardation layer in a desired direction.
The alignment layer A preferably has solvent resistance so that it does not dissolve when the liquid crystal compound is applied or the like, which will be described later, and also has heat resistance in heat treatment for removing the solvent or for alignment of the polymerizable liquid crystal compound described later. Types of the alignment film include a rubbing alignment film, a photo-alignment film, and a groove alignment film having an uneven pattern or a plurality of grooves on the surface. When applied to a long roll-shaped film, a photo-alignment film in which an alignment regulating force is induced by polarized light irradiation is preferable because the alignment direction can be easily controlled.
Such an alignment film facilitates the alignment of the polymerizable liquid crystal compound. Moreover, various orientations such as horizontal orientation, hybrid orientation, and tilted orientation can be controlled depending on the type of orientation film, rubbing conditions, and light irradiation conditions.
The orientation layer A used to form the retardation layer can use an orientation film described in the orientation layer B described later. Alignment layer B may be the same as alignment layer A or may be different.

The thickness of the alignment layer A is usually in the range of 10 to 10000 nm (0.01 μm to 10 μm), preferably in the range of 80 to 800 nm (0.08 μm to 0.8 μm), more preferably 100 to 500 nm ( 0.1 μm to 0.5 μm). By forming the alignment layer A within this film thickness range, it is possible to suppress alignment defects.
[Retardation layer]

The elliptically polarizing plate of the present invention has an alignment layer A and then a retardation layer. The retardation layer is formed by applying a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as a composition for forming a retardation layer) on the alignment layer A to form a coating layer, and in this coating layer, a polymerizable liquid crystal compound is oriented and polymerized and cured in this state to form a layer composed of a polymer, in terms of thickness reduction and wavelength dispersion characteristics can be arbitrarily designed. Further, the composition used for forming the retardation layer (hereinafter referred to as the composition for forming the retardation layer) includes a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent and an adhesion improver. and so on.

The retardation layer in the elliptical polarizing plate of the present invention is usually formed by applying a retardation layer-forming composition to the alignment layer A formed on the substrate, and polymerizing the composition contained in the optically anisotropic layer-forming composition. It is formed by polymerizing a polar liquid crystal compound. The retardation layer is usually a film having a thickness of 5 μm or less, which is cured while the polymerizable liquid crystal compound is aligned, preferably cured while the polymerizable liquid crystal compound is aligned horizontally with respect to the substrate surface. It is a liquid crystal cured film.

The retardation layer cured in a state in which the polymerizable liquid crystal compound is aligned in the horizontal direction with respect to the substrate surface has an in-plane retardation R (λ) for light with a wavelength of λ nm, which is represented by the following formula (1). It preferably satisfies the optical properties, and more preferably satisfies the optical properties represented by the following formulas (1), (2) and (3).
100 nm<Re(550)<160 nm (1)
(In the formula, Re (550) represents an in-plane retardation value (in-plane retardation) for light with a wavelength of 550 nm.)
Re(450)/Re(550)≤1.0 (2)
1.00≦Re(650)/Re(550) (3)
(In the formula, Re (450) is the in-plane retardation value for light with a wavelength of 450 nm, Re (550) is the in-plane retardation value for light with a wavelength of 550 nm, and Re (650) is the in-plane retardation value for light with a wavelength of 650 nm. represents the phase difference value.)
When "Re (450) / Re (550)" of the retardation layer exceeds 1.0, light leakage on the short wavelength side in the elliptically polarizing plate provided with the retardation layer increases, so it is 1.0 or less. is preferably 0.95 or less, and still more preferably 0.92 or less.

The in-plane retardation value of the retardation layer can be adjusted by the thickness of the retardation layer. Since the in-plane retardation value is determined by the following formula (4), in order to obtain the desired in-plane retardation value (Re(λ)), Δn(λ) and the film thickness d should be adjusted. . The thickness of the retardation layer is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation layer can be measured with an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.
Re(λ)=d×Δn(λ) (4)
(Wherein, Re (λ) represents the in-plane retardation value at the wavelength λ nm, d represents the film thickness, and Δn (λ) represents the birefringence at the wavelength λ nm.)

[Polymerizable Liquid Crystal Compound for Retardation Layer Formation]
A polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable functional group, particularly a photopolymerizable functional group. A photopolymerizable functional group is a group that can participate in a polymerization reaction by an active radical generated from a photopolymerization initiator, an acid, or the like. Photopolymerizable functional groups include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferred, and an acryloyloxy group is more preferred. Thermotropic liquid crystals or lyotropic liquid crystals may be used as liquid crystals, but thermotropic liquid crystals are preferred because they allow precise film thickness control. Moreover, the phase order structure in the thermotropic liquid crystal may be either a nematic phase structure or a smectic phase structure.

In the present invention, as the polymerizable liquid crystal compound forming the retardation layer, a compound having the structure of the following formula (I) is particularly preferable in terms of exhibiting the reverse wavelength dispersion described above.

In formula (I), Ar represents a divalent aromatic group, and the divalent aromatic group contains at least one or more of a nitrogen atom, an oxygen atom and a sulfur atom.
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a carbon may be substituted with an alkoxy group, a cyano group or a nitro group having a number of 1 to 4, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group are an oxygen atom or a sulfur atom; Alternatively, it may be substituted with 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 each independently represents an integer of 0 to 3 and satisfies the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, wherein the hydrogen atoms contained in the alkanediyl group may be substituted with a halogen atom, and the alkanediyl group —CH ₂ — included may be substituted with —O— or —Si—.
P ¹ and P ² independently represent a polymerizable group or a hydrogen atom, at least one of which is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenyl group optionally 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; A 1,4-cyclohexyl group optionally 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 substituted with a methyl group -phenyl group, unsubstituted 1,4-phenyl group or unsubstituted 1,4-trans-cyclohexyl group, particularly preferably unsubstituted 1,4-phenyl group or unsubstituted 1,4- It is a trans-cyclohexyl group.
At least one of G ¹ and G ² present in plurality is preferably a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² is more preferably a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, -O-, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a =CR ^b -, or -C≡C-. Here, R ^a and R ^b represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and L ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO- or -OCO-.

B ¹ and B ² are each independently preferably a single bond, —O—, —S—, —CH ₂ O—, —COO— or —OCO—, more preferably a single bond, —O -, -COO-, or -OCO-.

k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, more preferably k=2 and l=2, from the viewpoint of exhibiting reverse wavelength dispersion. It is preferable that k=2 and l=2 because of the symmetrical structure.

E ¹ and E ² are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

Polymerizable groups represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group and oxiranyl group. , and oxetanyl groups.
Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferred, and an acryloyloxy group is more preferred.

Ar preferably has an aromatic heterocycle. Examples of the aromatic heterocyclic ring include furan ring, benzofuran ring, pyrrole ring, thiophene ring, pyridine ring, thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. . Among them, it preferably has a thiazole ring, a benzothiazole ring, or a benzofuran ring, and more preferably has a benzothiazole group.
Moreover, when a nitrogen atom is contained in Ar, the nitrogen atom preferably has a π electron.

In formula (I), the total number Nπ of _π electrons contained in the divalent aromatic group represented by Ar is preferably 10 or more, more preferably 14 or more, and still more preferably 18 or more. Also, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

Examples of aromatic groups represented by Ar include the following groups.

In formulas (Ar-1) to (Ar-20), * represents a linking moiety, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl 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, alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms or carbon represents an N,N-dialkylsulfamoyl group of numbers 2 to 12;

Q ¹ , Q ² and Q ³ each independently represent -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, -CO- or -O-, and R ^2' and R ^3′ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

Y ¹ , Y ² and Y ³ each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group.

W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0-6.

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group. , is preferably a naphthyl group, more preferably a phenyl group. The aromatic heterocyclic group includes a C4-20 group containing at least one heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group. An aromatic heterocyclic group can be mentioned, and a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group are preferable.

Y ¹ , Y ² and Y ³ may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. A polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. A polycyclic aromatic heterocyclic group refers to a condensed polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² 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, an alkoxy group having 1 to 12 carbon atoms, and Z ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

Q ¹ , Q ² and Q ³ are preferably -NH-, -S-, -NR ^2' - and -O-, and R ^2' is preferably a hydrogen atom. Among them, -S-, -O- and -NH- are particularly preferred.

Among formulas (Ar-1) to (Ar-20), formulas (Ar-6) and (Ar-7) are preferable from the viewpoint of molecular stability.
In formulas (Ar-14) to (Ar-20), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is attached and Z ⁰ . Examples thereof include pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, indole ring, quinoline ring, isoquinoline ring, purine ring and pyrrolidine ring. This aromatic heterocyclic group may have a substituent. In addition, Y ¹ , together with the nitrogen atom and Z ⁰ to which it is attached, may be the aforementioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group.

The total content of the polymerizable liquid crystal compound in 100 parts by mass of the solid content of the retardation layer-forming composition is usually 70 parts by mass to 99.5 parts by mass, preferably 80 parts by mass to 99 parts by mass. parts, more preferably 80 to 94 parts by mass. If the total content is within the above range, the orientation of the obtained retardation layer tends to be high. Here, the solid content refers to the total amount of components of the composition excluding the solvent.

[Orientation layer B (orientation film for forming a polarizing layer)]
The elliptically polarizing plate of the present invention has an alignment layer B next to the retardation layer. The alignment layer B is an alignment film for forming a polarizing layer.
The alignment layer B has a solvent resistance that does not dissolve when a composition for forming a polarizing layer described later is applied, etc., and has heat resistance in heat treatment for removing the solvent and for alignment of the polymerizable liquid crystal compound described later. things are preferred. Types of the alignment film include a rubbing alignment film, a photo-alignment film, and a groove alignment film having an uneven pattern or a plurality of grooves on the surface. When applied to a long roll-shaped film, a photo-alignment film in which an alignment regulating force is induced by polarized light irradiation is preferable because the alignment direction can be easily controlled.
Such an alignment film facilitates the alignment of the polymerizable liquid crystal compound. Moreover, various orientations such as horizontal orientation, hybrid orientation, and tilted orientation can be controlled depending on the type of orientation film, rubbing conditions, and light irradiation conditions.

The thickness of the alignment layer B is in the range of 80-800 nm (0.08 μm-0.8 μm), preferably in the range of 100-500 nm (0.1 μm-0.5 μm), more preferably 150 nm (0.8 μm). .15 μm) or more. If the film thickness is smaller than this range, the optic axis of the polarizing layer next to the alignment layer B is deviated from the desired value due to the influence of the layer formed directly under the alignment layer, that is, the retardation layer. Sometimes. On the other hand, if the film thickness is larger than this range, the alignment regulating force may be lowered and an alignment defect may occur in the polarizing layer.

Examples of the oriented polymer used for the rubbed alignment film include polyamides and gelatins having amide bonds, polyimides having imide bonds and their hydrolysates such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, poly Oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic acid esters. Among them, polyvinyl alcohol is preferred. You may combine two or more types of oriented polymers.

A rubbing alignment film is generally formed by coating a substrate with a composition in which an orienting polymer is dissolved in a solvent, removing the solvent to form a coating film, and rubbing the coating film to impart an alignment regulating force. can be done.

The concentration of the oriented polymer in the oriented polymer composition may be within a range in which the oriented polymer is completely dissolved in the solvent. The content of the oriented polymer in the oriented polymer composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass.

Orientable polymer compositions are commercially available. Commercially available oriented polymer compositions include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optomer (registered trademark, manufactured by JSR Corporation).

The method for applying the oriented polymer composition includes the same method as the method for applying the composition for forming an optically anisotropic layer, which will be described later. Methods for removing the solvent contained in the oriented polymer composition include natural drying, ventilation drying, heat drying, and vacuum drying.

Examples of the rubbing method include a method in which the coating film is brought into contact with a rubbing roll wound with a rubbing cloth and rotating. A plurality of regions (patterns) with different alignment directions can be formed in the alignment film by masking during the rubbing process.

The photo-alignment film is usually formed by applying a photo-alignment film-forming composition containing a polymer or monomer having a photoreactive group and a solvent onto a substrate or the like, and after removing the solvent, polarized light (preferably, polarized UV). obtained by irradiating The photo-alignment film can arbitrarily control the direction of the alignment regulating force by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group refers to a group that produces alignment ability upon irradiation with light. Specific examples thereof include groups involved in photoreactions that are the origin of alignment ability, such as orientation-inducing reactions, isomerization reactions, photodimerization reactions, photocrosslinking reactions, and photodegradation reactions of molecules caused by light irradiation. The photoreactive group is preferably a group having an unsaturated bond, particularly a double bond, such as carbon-carbon double bond (C=C bond), carbon-nitrogen double bond (C=N bond), nitrogen-nitrogen Groups having at least one selected from the group consisting of a double bond (N=N bond) and a carbon-oxygen double bond (C=O bond) are particularly preferred.

Photoreactive groups having a C═C bond include, for example, vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups and cinnamoyl groups. Examples of the photoreactive group having a C═N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. The photoreactive group having an N=N bond includes, for example, an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Photoreactive groups having a C=O bond include, for example, benzophenone groups, coumarin groups, anthraquinone groups and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

A group involved in a photodimerization reaction or a photocrosslinking reaction is preferable from the viewpoint of excellent orientation. Among them, a photoreactive group that participates in a photodimerization reaction is preferable, and a cinnamoyl group is preferred because the amount of polarized light irradiation required for alignment is relatively small, and a photoalignment film having excellent thermal stability and stability over time can be easily obtained. and chalcone groups are preferred. As a polymer having a photoreactive group, a polymer having a cinnamoyl group having a cinnamic acid structure or a cinnamic acid ester structure at the end of the polymer side chain is particularly preferred.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be adjusted depending on the type of polymer or monomer and the thickness of the desired photo-alignment film, and is at least 0.2% by mass or more. preferably in the range of 0.3 to 10% by mass.

The method of applying the composition for forming a photo-alignment film includes the same method as the method of applying the composition for forming an optically anisotropic layer, which will be described later. The method for removing the solvent from the coated composition for forming a photo-alignment film includes the same method as the method for removing the solvent from the orienting polymer composition.

In order to irradiate polarized light, the composition for forming a photo-alignment film coated on the base material etc. may be directly irradiated with polarized light after removing the solvent. may be irradiated, and polarized light may be transmitted and irradiated. Also, the polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb the light energy. Specifically, UV (ultraviolet rays) with a wavelength in the range of 250 nm to 400 nm is particularly preferred. Examples of the light source for irradiating the polarized light include a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, and an ultraviolet light laser such as KrF or ArF. Among them, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a metal halide lamp are preferable because of their high emission intensity of ultraviolet rays having a wavelength of 313 nm.
Polarized UV can be emitted by passing the light from the light source through a suitable polarizing element. Polarizing elements include polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire grids. Among them, a wire grid type polarizing element is preferable from the viewpoint of large area and resistance to heat.

A plurality of regions (patterns) having different liquid crystal orientation directions can be formed by masking during rubbing or polarized light irradiation.

A groove alignment film is a film having an uneven pattern or a plurality of grooves on its surface. When a polymerizable liquid crystal compound is applied to a film having a plurality of linear grooves arranged at regular intervals, liquid crystal molecules are aligned along the grooves.
As a method for obtaining a grooved alignment film, after exposure through an exposure mask having pattern-shaped slits on the surface of a photosensitive polyimide film, development and rinsing are performed to form an uneven pattern, and a plate having grooves on the surface. A method of forming a UV curable resin layer before curing on a shaped master, transferring the resin layer to a substrate, etc. and then curing it, and a UV curable resin film before curing formed on a substrate, etc. , a method of forming unevenness by pressing a roll-shaped master plate having a plurality of grooves, and then curing the same.

[Polarizing layer]
The elliptically polarizing plate of the present invention has an orientation layer B followed by a polarizing layer. This polarizing layer is formed by applying a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as a "polarizing layer-forming composition") on the alignment layer B, and the dichroic dye and the polymerizable liquid crystal compound are aligned. It can be produced by forming a polarizing layer made of a polymer of a polymerizable liquid crystal compound in . That is, light is anisotropically absorbed by the dichroic dye contained in the liquid crystal compound, thereby absorbing the linearly polarized light component having a plane of vibration parallel to the absorption axis, and absorbing the linearly polarized light component having a plane of vibration perpendicular to the absorption axis. becomes a polarizing plate that transmits Such a polarizing plate is preferable in that the hue can be arbitrarily controlled by the dichroic dye and in that it can be made thinner. In addition, the polarizing layer-forming composition may further include a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, and the like.

The polarizing layer in the elliptically polarizing plate of the present invention is usually formed by coating a polarizing layer-forming composition on an orientation layer B formed on a transparent substrate or the like, and polymerizing the polarizing layer-forming composition contained in the polarizing layer-forming composition. It is formed by polymerizing a polar liquid crystal compound. The polarizing layer is usually a film having a thickness of 5 μm or less, preferably 4 μm or less, more preferably 3 μm or less, which is cured with the polymerizable liquid crystal compound oriented. If the film thickness is greater than this range, the orientation control force of the orientation film is reduced, and orientation defects tend to occur.

In order to obtain polarization characteristics in the XY plane, the polymerizable liquid crystal compound may be cured in a state in which the dichroic dye and the polymerizable liquid crystal compound are aligned horizontally with respect to the surface of the transparent substrate. In order to obtain polarization characteristics in the film thickness direction of the polarizing layer), the polymerizable liquid crystal compound may be cured in a state in which the dichroic dye and the polymerizable liquid crystal compound are vertically aligned with respect to the surface of the transparent substrate. In this case, from the viewpoint of selectivity of polarized light absorption, a cured liquid crystal film in which the polymerizable liquid crystal compound is cured in a smectic liquid crystal phase is preferable, and a cured liquid crystal film in which a polymerizable liquid crystal compound is cured in a high-order smectic liquid crystal phase is more preferable. be. The high-order smectic liquid crystal phases referred to herein are smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase and smectic L phase. Among them, smectic B phase, smectic F phase and smectic I phase are more preferable.

These high-order smectic liquid crystal phases can produce polarizing layers with a higher degree of orientational order. In addition, a polarizing layer produced from a high-order smectic liquid crystal phase having a high degree of orientational order exhibits a Bragg peak derived from a high-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from the surface periodic structure of molecular orientation. According to the composition for forming a polarizing layer according to the present embodiment, a polarizing layer having a periodic spacing of 3.0 to 5.0 Å is obtained. be able to.

Whether or not the polymerizable liquid crystal compound exhibits a nematic liquid crystal phase or a smectic liquid crystal phase can be confirmed, for example, as follows. After the composition for forming a polarizing layer is applied to a base material to form a coating film, the solvent contained in the coating film is removed by heat-treating under conditions in which the polymerizable liquid crystal compound is not polymerized. Subsequently, the coating film formed on the substrate is heated to the isotropic phase temperature, and the liquid crystal phase developed by gradually cooling is inspected by texture observation with a polarizing microscope, X-ray diffraction measurement, or differential scanning calorimetry. do. Whether the polymerizable liquid crystal compound and the dichroic dye are not phase-separated in the nematic liquid crystal phase and the smectic liquid crystal phase can be confirmed, for example, by surface observation with various microscopes or scattering degree measurement with a haze meter.

The optically anisotropic layer obtained by curing the polymerizable liquid crystal compound in a state in which the dichroic dye and the polymerizable liquid crystal compound are horizontally aligned with respect to the surface of the transparent substrate has an absorbance A1 (λ) and the absorbance A2(λ) in the direction perpendicular to the liquid crystal orientation (dichroic ratio) is preferably 7 or more, more preferably 20 or more, and still more preferably 30 or more. The higher this value, the more excellent the absorption selectivity of the polarizing plate. Although it depends on the type of dichroic dye, it is about 5 to 10 in the case of a cured liquid crystal film cured in a nematic liquid crystal phase.

By mixing two or more kinds of dichroic dyes with different absorption wavelengths, polarizing layers with various hues can be produced, and a polarizing layer that absorbs all visible light can be obtained. A polarizing layer having such absorption characteristics can be blackened and can be used in various applications. The polarizing performance of the polarizing layer can be measured using a spectrophotometer. For example, the transmittance (T1) in the direction of the transmission axis (perpendicular to the orientation) and the transmittance (T2) in the direction of the absorption axis (the same direction of orientation) in the wavelength range of 380 nm to 780 nm, which is visible light, are measured with a spectrophotometer using a polarizer. It can be measured by the double beam method using a device with a folder attached. For the polarization performance in the visible light range, the single transmittance and degree of polarization at each wavelength are calculated using the following formulas (Formula 1) and (Formula 2). By performing visibility correction, it is possible to calculate the visibility correction single transmittance (Ty) and the visibility correction polarization degree (Py). In addition, from the transmittance measured in the same manner, the color matching function of the C light source is used to calculate the chromaticities a* and b* in the L*a*b* (CIE) color system, thereby obtaining the hue of the polarizing plate alone. (single hue), a hue obtained by arranging polarizing plates in parallel (parallel hue), and a hue obtained by arranging polarizing plates orthogonally (orthogonal hue) are obtained.
It can be determined that the closer the a* and b* values are to 0, the more neutral the hue.

Single transmittance (%)=(T1+T2)/2 (Formula 1)
Degree of polarization (%) = (T1-T2)/(T1+T2) x 100 (Formula 2)

[Polymerizable liquid crystal compound for forming polarizing layer]
A polymerizable liquid crystal compound is a compound having a polymerizable group and liquid crystallinity. A polymerizable group means a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group that can participate in a polymerization reaction by an active radical generated from a photopolymerization initiator described below, an acid, or the like. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferred, and an acryloyloxy group is more preferred. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal, but a thermotropic liquid crystal is preferred when it is mixed with a dichroic dye, which will be described later.

When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. In the present invention, the polymerizable liquid crystal compound is preferably a smectic liquid crystal compound, more preferably a high-order smectic liquid crystal compound, from the viewpoint of obtaining higher polarization properties. Among them, high-order smectic liquid crystal compounds forming smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase or smectic L phase. Higher order smectic liquid crystal compounds forming a smectic B phase, a smectic F phase or a smectic I phase are more preferred. When the liquid crystal phase formed by the polymerizable liquid crystal compound is these high-order smectic phases, a polarizing layer with higher polarizing performance can be produced. Moreover, a polarizing layer having such a high polarizing performance gives a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from the periodic structure of molecular orientation, and a film having a periodic interval of 3 to 6 Å can be obtained. The polarizing layer used in the present invention preferably contains a polymer of a polymerizable liquid crystal compound polymerized in a smectic phase from the viewpoint of obtaining higher polarizing properties.

Specific examples of such compounds include compounds represented by the following formula (A) (hereinafter sometimes referred to as compound (A)). The polymerizable liquid crystal compound may be used alone or in combination of two or more.

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (A) [in formula (A),
X ¹ , X ² and X ³ each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein the divalent aromatic group or divalent alicyclic A hydrogen atom contained in the hydrocarbon group is substituted with 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. A carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. provided that at least one of X ¹ , X ² and X ³ is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group is.
Y ¹ , Y ² , W ¹ and W ² are each independently a single bond or a divalent linking group.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — It may be substituted with S- or NH-.
U ¹ and U ² independently of each other represent a polymerizable group or a hydrogen atom, at least one of which is a polymerizable group.

In compound (A), at least one of X ¹ , X ² and X ³ is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane- A 1,4-diyl group is preferred. In particular, X ¹ and X ³ are more preferably an optionally substituted cyclohexane-1,4-diyl group, and the cyclohexane-1,4-diyl group is trans-cyclohexane A -1,4-diyl group is more preferred. When it contains a trans-cyclohexane-1,4-diyl group structure, it tends to exhibit smectic liquid crystallinity. Further, optionally substituted 1,4-phenylene group or optionally substituted cyclohexane-1,4-diyl group optionally has a methyl group , an alkyl group having 1 to 4 carbon atoms such as an ethyl group and a butyl group, a cyano group and a halogen atom such as a chlorine atom and a fluorine atom, preferably unsubstituted.

Y ¹ and Y ² are each independently a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a =CR ^b -, - C≡C— or CR ^a =N— is preferred, and R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ¹ and Y ² are more preferably -CH ₂ CH ₂ -, -COO-, -OCO- or a single bond, and more preferably Y ¹ and Y ² are different from each other. When Y ¹ and Y ² are different from each other, smectic liquid crystallinity tends to develop.

W ¹ and W ² are each independently preferably a single bond, —O—, —S—, —COO— or OCO—, and are more preferably each independently a single bond or —O—.

The alkanediyl groups having 1 to 20 carbon atoms represented by V ¹ and V ² include methylene group, ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, butane-1,4 -diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane -1,14-diyl group and icosane-1,20-diyl group. V ¹ and V ² are preferably C 2-12 alkanediyl groups, more preferably straight-chain C 6-12 alkanediyl groups. The straight-chain alkanediyl group having 6 to 12 carbon atoms improves crystallinity and tends to exhibit smectic liquid crystallinity.
Examples of substituents optionally possessed by the optionally substituted alkanediyl group having 1 to 20 carbon atoms include a cyano group and a halogen atom such as a chlorine atom and a fluorine atom, and the alkanediyl group is , is preferably unsubstituted, and more preferably an unsubstituted and linear alkanediyl group.

Both U ¹ and U ² are preferably polymerizable groups, more preferably photopolymerizable groups. A polymerizable liquid crystal compound having a photopolymerizable group can be polymerized under a lower temperature condition than a thermally polymerizable group, so it is advantageous in that a polymer can be formed in a state where the liquid crystal has a higher degree of order.

^The polymerizable groups represented by U1 and U2 may be different from ^each other, but are preferably the same. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferred, and a methacryloyloxy group or an acryloyloxy group is more preferred.

Examples of such polymerizable liquid crystal compounds include the following.

Among the exemplified compounds, formula (1-2), formula (1-3), formula (1-4), formula (1-6), formula (1-7), formula (1-8), formula At least one selected from the group consisting of compounds represented by (1-13), formula (1-14) and formula (1-15) is preferred.

The exemplified compound (A) can be used for the polarizing layer either singly or in combination. When two or more polymerizable liquid crystal compounds are combined, at least one is preferably compound (A), and two or more are more preferably compound (A). By combining two or more types of polymerizable liquid crystal compounds, it may be possible to temporarily maintain liquid crystallinity even at temperatures below the liquid crystal-crystal phase transition temperature. The mixing ratio when two types of polymerizable liquid crystal compounds are combined is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50. is.

Compound (A) can be prepared, for example, by Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or a known method described in Japanese Patent No. 4,719,156.

The content of the polymerizable liquid crystal compound in the polarizing layer-forming composition is usually 50 to 99.5 parts by mass, preferably 60 to 99 parts by mass, per 100 parts by mass of the solid content of the polarizing layer-forming composition. , more preferably 70 to 98 parts by mass, still more preferably 80 to 97 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, the orientation tends to be high. Here, the solid content refers to the total amount of components excluding the solvent from the polarizing layer-forming composition.

[Dichroic dye for forming polarizing layer]
A dichroic dye is a dye that has different absorbances in the long-axis direction and the short-axis direction of the molecule. The dichroic dye preferably has a property of absorbing visible light, and more preferably has a maximum absorption wavelength (λMAX) in the range of 380 to 680 nm. Such dichroic dyes include, for example, acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, with azo dyes being preferred. The azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes and stilbene azo dyes, preferably bisazo dyes and trisazo dyes. Dichroic dyes may be used alone or in combination, but in order to obtain absorption in the entire visible light range, it is preferable to combine three or more dichroic dyes, more preferably three or more azo dyes. preferable.

Examples of azo dyes include compounds represented by formula (B) (hereinafter sometimes referred to as "compound (B)").
T ¹ -A ¹ (-N=NA ² ) _p -N=NA ³ -T ² (B)
[In formula (B),
A ¹ and A ² and A ³ each independently represent an optionally substituted 1,4-phenylene group, a naphthalene-1,4-diyl group or an optionally substituted divalent represents a heterocyclic group, A ¹ or/and A ² are 1,4-phenylene groups, T ¹ and T ² are electron-withdrawing groups or electron-releasing groups, and substantially 180 ° position. p represents an integer of 0 to 4; When p is 2, two A ² may be the same or different. ]

Examples of substituents optionally possessed by the 1,4-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ¹ , A ² and A ³ include methyl group, ethyl group and butyl group. C1-C4 alkyl group; C1-C4 alkoxy group such as methoxy group, ethoxy group and butoxy group; C1-C4 fluorinated alkyl group such as trifluoromethyl group; Cyano group; Nitro group halogen atoms such as chlorine atoms and fluorine atoms; substituted or unsubstituted amino groups such as amino groups, diethylamino groups and pyrrolidino groups (substituted amino groups are amino groups having one or two alkyl groups having 1 to 6 carbon atoms; or an amino group in which two substituted alkyl groups are bonded together to form an alkanediyl group having 2 to 8 carbon atoms, and an unsubstituted amino group is —NH ₂ .). Examples of alkyl groups having 1 to 6 carbon atoms include methyl group, ethyl group and hexyl group. Examples of alkanediyl groups having 2 to 8 carbon atoms include ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, and pentane-1,5-diyl group. , hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group and the like. For inclusion in highly ordered liquid crystal structures such as smectic liquid crystals, A ¹ and A ² and A ³ are 1,4-phenylene groups that are unsubstituted or substituted with methyl or methoxy groups for hydrogen, or divalent is preferred, and p is preferably 0 or 1. Above all, p is 1 and at least two of the three structures of A ¹ , A ² and A ³ are 1,4-phenylene groups in terms of both simplicity of molecular synthesis and high performance. more preferred.

Divalent heterocyclic groups include groups obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole and benzoxazole. When ^A2 is a divalent heterocyclic group, it preferably has a structure in which the molecular bond angle is substantially 180°. Structure is more preferred.

T ¹ and T ² are electron-withdrawing groups or electron-releasing groups, preferably different structures, T ¹ is an electron-withdrawing group and T ² electron-releasing group, or T ¹ is an electron-releasing group and T ² electron-withdrawing group A group relationship is more preferable. Specifically, T ¹ and T ² are each independently one or more of 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 alkyl group having 1 to 6 carbon atoms, or An amino group having two amino groups, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, or a trifluoromethyl group is preferable, and among them, a highly ordered smectic liquid crystal. In order to be included in the liquid crystal structure, it is necessary to have a structure with a smaller excluded volume of molecules. An amino group having one or two alkyl groups of up to 6, or an amino group in which two substituted alkyl groups are bonded together to form an alkanediyl group having 2 to 8 carbon atoms are preferred.

Examples of such azo dyes include the following.

In formulas (2-1) to (2-6),
B ¹ to B ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (substituted amino group and The definition of unsubstituted amino group is as described above), chlorine atom or trifluoromethyl group.
n1 to n4 each independently represent an integer of 0 to 3;
When n1 is ² or more, the plurality of B2 may be the same or different,
When n2 is 2 or more, 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 ^B14 may be the same or different.

As the anthraquinone dye, a compound represented by formula (2-7) is preferable.

[In formula (2-7),
R ¹ to R ⁸ each independently represent a hydrogen atom, —R ^x , —NH ₂ , —NHR ^x , —NR ^x ₂ , —SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

As the oxazine dye, a compound represented by formula (2-8) is preferable.

[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.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

As the acridine dye, a compound represented by formula (2-9) is preferable.

[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.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

In formula (2-7), formula (2-8) and formula (2-9), the alkyl group having 1 to 4 carbon atoms represented by R ^x includes a methyl group, an ethyl group, a propyl group and a butyl group. , pentyl group and hexyl group, and the aryl group having 6 to 12 carbon atoms includes phenyl group, toluyl group, xylyl group and naphthyl group.

As the cyanine dye, a compound represented by formula (2-10) and a compound represented by formula (2-11) are preferable.

ｎ５は１～３の整数を表す。］ [In formula (2-10),
D ¹ and D ² each independently represent a group represented by any one of formulas (2-10a) to (2-10d).

n5 represents an integer of 1-3. ]

ｎ６は１～３の整数を表す。］ [In formula (2-11),
D ³ and D ⁴ each independently represent a group represented by any one of formulas (2-11a) to (2-11h).

n6 represents an integer of 1-3. ]

The content of the dichroic dye (the total amount when multiple types are included) is usually 1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound from the viewpoint of obtaining good light absorption characteristics, It is preferably 2 to 20 parts by mass, more preferably 3 to 15 parts by mass. If the content of the dichroic dye is less than this range, light absorption will be insufficient, resulting in insufficient polarizing performance.

[Angle Formed by Polarizing Layer and Retardation Layer]
In the elliptically polarizing plate of the present invention, the optic axes of the polarizing layer and the retardation layer are substantially parallel, that is, the optic axis of the polarizing layer and the optic axis of the retardation layer are substantially in the plane of the elliptically polarizing plate. The optical axis of the polarizing layer and the optical axis of the retardation layer intersect within the plane of the elliptically polarizing plate, rather than in a non-intersecting relationship. The angle formed by the optic axis of the polarizing layer and the optic axis of the retardation layer that intersect each other is preferably 40 to 50°, and preferably 41 to 49, as the angle formed by the slow axis of the retardation layer and the absorption axis of the polarizing layer. °, more preferably 43 to 47°, particularly preferably substantially 45°, ideally 45°. When the angle formed by the slow axis of the retardation layer and the absorption axis of the polarizing layer is within the above range, the ellipticity is improved. .

[solvent]
The solvent is preferably a solvent capable of completely dissolving the polymerizable liquid crystal compound used in forming the retardation layer or the polarizing layer, and is preferably inert to the polymerization reaction of the polymerizable liquid crystal compound.
Examples of solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ - ester solvents such as butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane. 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; Examples include amide solvents such as pyrrolidone and 1,3-dimethyl-2-imidazolidinone. These solvents may 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 in 100 parts by weight of the composition is preferably 50 parts by weight to 98 parts by weight, more preferably 70 parts by weight to 95 parts by weight. 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 50 parts by mass or less, the viscosity of the composition becomes low, so that the thickness of the film containing the polymerizable liquid crystal compound becomes substantially uniform, and the film containing the polymerizable liquid crystal compound becomes uneven. tends to be difficult. The solid content can be appropriately determined in consideration of the thickness of the film containing the polymerizable liquid crystal compound to be produced.

[Photoinitiator]
A polymerization initiator is a compound capable of initiating a polymerization reaction such as a polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator that generates radicals by light irradiation is more preferable.
Examples of photopolymerization initiators include benzoin compounds, benzophenone compounds, benzylketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, triazine compounds, iodonium salts and sulfonium salts. Specifically, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369, Irgacure 379, Irgacure 127, Irgacure 2959, Irgacure 754, Irgacure 379EG (above, BASF Japan Corporation ), Seikuol BZ, Seikuol Z, Seikuol BEE (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 Arkles NCI-831, Adeka Arkles NCI-930 (manufactured by ADEKA Co., Ltd.), TAZ-A, TAZ -PP (manufactured by Nihon SiberHegner Co., Ltd.) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).
The composition for forming the retardation layer or the composition for forming the polarizing layer contains at least one type of photopolymerization initiator, preferably one type or two types.

Since the photopolymerization initiator can fully utilize the energy emitted from the light source and is excellent in productivity, the maximum absorption wavelength is preferably 300 nm to 380 nm, more preferably 300 nm to 360 nm. Acetophenone-based polymerization initiators and oxime-based photopolymerization initiators are preferred.

α-Acetophenone compounds include 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutane-1 -one and 2-dimethylamino-1-(4-morpholinophenyl)-2-(4-methylphenylmethyl)butan-1-one and the like, more preferably 2-methyl-2-morpholino-1-( 4-methylsulfanylphenyl)propan-1-one and 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one and the like. Commercially available α-acetophenone compounds include Irgacure 369, 379EG and 907 (manufactured by BASF Japan Ltd.) and Seikuol BEE (manufactured by Seiko Kagaku Co., Ltd.).

The oxime-based photopolymerization initiator generates methyl radicals upon irradiation with light. Polymerization of the polymerizable liquid crystal compound in the deep portion of the film containing the polymerizable liquid crystal compound preferably proceeds due to this methyl radical. From the viewpoint of more efficiently progressing the polymerization reaction in the deep part of the film containing the polymerizable liquid crystal compound, it is preferable to use a photopolymerization initiator capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more. Triazine compounds and oxime ester-type carbazole compounds are preferable as photopolymerization initiators capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more, and oxime ester-type carbazole compounds are more preferable from the viewpoint of sensitivity. Oxime ester-type carbazole compounds include 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl )-9H-carbazol-3-yl]-1-(O-acetyloxime) and the like. Commercially available oxime ester-type carbazole compounds include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (manufactured by BASF Japan Ltd.), Adeka Optomer N-1919, and Adeka Arkles NCI-831 (manufactured by BASF Japan Ltd.). , manufactured by ADEKA Corporation) and the like.

The amount of the photopolymerization initiator added is usually 0.1 parts by mass to 30 parts by mass, preferably 1 part by mass to 20 parts by mass, more preferably 3 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. Parts by mass to 18 parts by mass. Within the above range, the reaction of the polymerizable group proceeds sufficiently and the alignment of the polymerizable liquid crystal compound is less likely to be disturbed.

By adding a polymerization inhibitor, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. Examples of polymerization inhibitors include hydroquinones having substituents such as hydroquinone and alkyl ethers; catechols having substituents such as alkyl ethers such as butyl catechol; pyrogallols, 2,2,6,6-tetramethyl-1- Radical scavengers such as piperidinyloxy radicals; thiophenols; β-naphthylamines and β-naphthols. In order to polymerize the polymerizable liquid crystal compound without disturbing the orientation of the polymerizable liquid crystal compound, the content of the polymerization inhibitor is usually 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. Yes, preferably 0.5 to 5 parts by mass, more preferably 0.5 to 3 parts by mass.

Furthermore, by using a photosensitizer, the sensitivity of the photopolymerization initiator can be increased. Examples of photosensitizers include xanthones such as xanthone and thioxanthone; anthracenes having substituents such as anthracene and alkyl ether; phenothiazine; and rubrene. Examples of photosensitizers include xanthones such as xanthone and thioxanthone; anthracenes having substituents such as anthracene and alkyl ether; phenothiazine; and rubrene. The content of the photosensitizer is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the polymerizable liquid crystal compound. 3 parts by mass.

[Leveling agent]
The leveling agent is an additive that has the function of adjusting the fluidity of the composition and making the film obtained by coating the composition more flat. Alkyl-based leveling agents can be used. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all from Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all from Momentive Performance Materials Japan G.K.) ), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M), Megafac (registered trademark) R-08 , R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479, F-482 , F-483 (all manufactured by DIC Corporation), F-top (trade name) EF301, EF303, EF351, EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surflon (registered Trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.) , trade names E1830, E5844 (manufactured by Daikin Fine Chemicals Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all trade names: manufactured by BM Chemie), etc. mentioned. Among them, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferred.

The content of the leveling agent in the composition for forming the retardation layer and the composition for forming the polarizing layer used in the present invention is preferably 0.01 part by mass to 5 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound, 0.1 to 3 parts by mass is more preferable. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound can be easily horizontally aligned, and the obtained film containing the polymerizable liquid crystal compound tends to be smoother, which is preferable. The retardation layer-forming composition and the polarizing layer-forming composition used in the present invention may contain two or more leveling agents.

[Adhesive]
Examples of adhesives for bonding the polarizing layer and the retardation layer or the retardation layer and the display device include pressure-sensitive adhesives, drying-hardening adhesives, and chemical reaction adhesives. Examples of chemically reactive adhesives include active energy ray-curable adhesives. As the adhesive between the polarizing layer and the retardation layer, an adhesive layer formed from a pressure-sensitive adhesive, a drying-hardening adhesive, or an active energy ray-curable adhesive is preferable, and is indicated as a retardation layer. As the adhesive between devices, an adhesive layer formed from a pressure-sensitive adhesive or an active energy ray-curable adhesive is preferred.

A pressure-sensitive adhesive usually contains a polymer and may contain a solvent.
Polymers include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, and the like. Among them, acrylic pressure-sensitive adhesives containing acrylic polymers have excellent optical transparency, moderate wettability and cohesive strength, excellent adhesiveness, high weather resistance and heat resistance, and are resistant to heat. It is preferable because it is less likely to float or peel off under humidified conditions.

Examples of acrylic polymers include (meth)acrylates in which the alkyl group of the ester moiety is an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, or a butyl group (hereinafter, acrylates and methacrylates are collectively referred to as (meth)acrylates and acrylic acid and methacrylic acid may be collectively referred to as (meth)acrylic acid), and (meth)acrylic acid and hydroxyethyl (meth)acrylate having functional groups such as (meth) Copolymers with acrylic monomers are preferred.

The pressure-sensitive adhesive containing such a copolymer has excellent adhesiveness, and can be removed relatively easily without causing adhesive residue or the like on the display device even when it is removed after being attached to the display device. is possible. The glass transition temperature of the acrylic polymer is preferably 25°C or lower, more preferably 0°C or lower. The weight average molecular weight of such acrylic polymer is preferably 100,000 or more.

Examples of the solvent include the solvents exemplified above as the solvent. The pressure-sensitive adhesive may contain a light diffusing agent. The light diffusing agent is an additive that imparts light diffusing properties to the pressure-sensitive adhesive, and may be fine particles having a refractive index different from the refractive index of the polymer contained in the pressure-sensitive adhesive. Light diffusing agents include fine particles made of inorganic compounds and fine particles made of organic compounds (polymers). Since many of the polymers contained as active ingredients in the adhesive, including acrylic polymers, have a refractive index of about 1.4 to 1.6, the light diffusing agent whose refractive index is 1.2 to 1.8 It is preferable to select them appropriately. The refractive index difference between the polymer contained as an active ingredient in the pressure-sensitive adhesive and the light diffusing agent is usually 0.01 or more, and preferably 0.01 to 0.2 from the viewpoint of the brightness and displayability of the display device. The microparticles used as the light diffusing agent are preferably spherical microparticles, more preferably microparticles close to monodisperse, and more preferably microparticles having an average particle diameter of 2 μm to 6 μm. The refractive index is measured by the common minimum deviation method or Abbe refractometer.
Fine particles made of inorganic compounds include aluminum oxide (refractive index: 1.76) and silicon oxide (refractive index: 1.45). Examples of fine particles 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 ~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 silicone Resin beads (refractive index 1.46) and the like can be mentioned. The content of the light diffusing agent is usually 3 to 30 parts by mass with respect to 100 parts by mass of the polymer.
The thickness of the pressure-sensitive adhesive is determined according to its adhesive strength and the like, and is not particularly limited, but is usually 1 μm to 40 μm. The thickness is preferably 3 μm to 25 μm, more preferably 5 μm to 20 μm, from the viewpoint of workability, durability, and the like. By setting the thickness of the adhesive layer formed from the adhesive to 5 μm to 20 μm, brightness is maintained when the display device is viewed from the front or obliquely, and blurring and blurring of the displayed image are suppressed. can be made difficult.

[Dry-hardening adhesive]
The drying-hardening adhesive may contain a solvent.
The dry-hardening adhesive contains a polymer of a monomer having a protic functional group such as a hydroxyl group, a carboxyl group, or an amino group and an ethylenically unsaturated group, or a urethane resin as a main component, and furthermore, a polyvalent Examples include compositions containing cross-linking agents or curing compounds such as aldehydes, epoxy compounds, epoxy resins, melamine compounds, zirconia compounds, and zinc compounds. Polymers of monomers having a protic functional group such as a hydroxyl group, a carboxyl group, or an amino group and an ethylenically unsaturated group include ethylene-maleic acid copolymers, itaconic acid copolymers, acrylic acid copolymers, and acrylamide. Copolymers, saponified products of polyvinyl acetate, polyvinyl alcohol resins, and the like can be mentioned.

Polyvinyl alcohol resins include polyvinyl alcohol, partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. mentioned. The content of the polyvinyl alcohol-based resin in the water-based adhesive is usually 1-10 parts by mass, preferably 1-5 parts by mass, per 100 parts by mass of water.

Examples of urethane resins include polyester-based ionomer-type urethane resins.
The polyester-based ionomer-type urethane resin referred to here is a urethane resin having a polyester skeleton, and is a resin into which a small amount of an ionic component (hydrophilic component) has been introduced. Since the ionomer-type urethane resin is emulsified in water to form an emulsion without using an emulsifier, it can be used as a water-based pressure-sensitive adhesive. When using a polyester-based ionomer-type urethane resin, it is effective to blend a water-soluble epoxy compound as a cross-linking agent.

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

The thickness of the adhesive layer formed from the drying-hardening adhesive is usually 0.001 μm to 5 μm, preferably 0.01 μm to 2 μm, more preferably 0.01 μm to 0.5 μm. be. If the pressure-sensitive adhesive layer formed from the drying-hardening adhesive is too thick, the optically anisotropic layer tends to have poor appearance.

[Active energy ray-curable adhesive]
The active energy ray-curable adhesive may contain a solvent. An active energy ray-curable adhesive is an adhesive that is cured by being irradiated with an active energy ray.
The active energy ray-curable adhesive includes a cationic polymerizable adhesive containing an epoxy compound and a cationic polymerization initiator, a radically polymerizable adhesive containing an acrylic curing component and a radical polymerization initiator, and an epoxy compound. An adhesive containing both a cationic polymerizable curing component such as an acrylic compound and a radically polymerizable curing component such as an acrylic compound, and further containing a cationic polymerization initiator and a radical polymerization initiator, and these polymerization initiators Examples include an adhesive that is cured by irradiating an electron beam without being exposed.

Among them, a radically polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator, and a cationically polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator. preferable. Examples of acrylic curing components include (meth)acrylates such as methyl (meth)acrylate and hydroxyethyl (meth)acrylate, and (meth)acrylic acid. The active energy ray-curable adhesive containing an epoxy compound may further contain a compound other than the epoxy compound. Examples of compounds other than epoxy compounds include oxetane compounds and acrylic compounds.
Examples of radical polymerization initiators include the photopolymerization initiators described above. Commercially available cationic polymerization initiators include "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" (manufactured by Midori Chemical Co., Ltd.), "Adeka Optomer" series (manufactured by ADEKA Corporation), "RHODORSIL" (registered trademark) (manufactured by Rhodia Corporation), etc. be done. The content of the radical polymerization initiator and the cationic polymerization initiator is usually 0.5 parts by mass to 20 parts by mass, preferably 1 part by mass to 15 parts by mass, with respect to 100 parts by mass of the active energy ray-curable adhesive. Department.

Active energy ray-curable adhesives further contain ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow control agents, plasticizers, antifoaming agents, and the like. may

As used herein, the active energy ray is defined as an energy ray capable of decomposing a compound that generates active species to generate active species. Such active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays and electron beams, with ultraviolet rays and electron beams being preferred. Preferred ultraviolet irradiation conditions are the same as those for the polymerization of the polymerizable liquid crystal compound described above.

[Refractive index of each layer of laminate]
When another layer B is laminated directly under a certain layer A, if the refractive index of layer A is n _A and the refractive index of layer B is n _B , when light is incident on layer A from a direction perpendicular to The interface reflectance between layers A and B is expressed by the following equation (K).

Interface reflectance (%) = (n _A - n _B ) ² / (n _A + n _B ) ² × 100 (K)

Therefore, when the refractive index difference between adjacent layers in the laminate is large, the loss due to interfacial reflection increases. In an elliptically polarizing plate composed of a laminate, the difference in refractive index between adjacent layers is preferably 0.20 or less, more preferably 0.15 or less, and 0.10 or less in order to reduce the effect of loss due to interfacial reflection. It is even more preferable to have

[Method for producing polarizing layer or retardation layer]
Hereinafter, the polarizing layer or retardation layer of the invention may be referred to as an optically anisotropic layer. Moreover, the composition for forming a polarizing layer or the composition for forming a retardation layer may be referred to as the composition for forming an optically anisotropic layer. The manufacturing methods of the polarizing layer and the retardation layer may be the same or different.

[Application of Composition for Forming Optically Anisotropic Layer]
An optically anisotropic layer can be formed by applying the composition for forming an optically anisotropic layer onto the above-mentioned transparent substrate or alignment film. Methods for applying the composition for forming an optically anisotropic layer onto a substrate include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, a micro gravure method, a die coating method, An ink jet method and the like can be mentioned. Moreover, the method of apply|coating using coaters, such as a dip coater, a bar coater, a spin coater, etc. are mentioned. Among them, when applying continuously in a Roll to Roll format, a micro gravure method, an inkjet method, a slit coating method, or a die coating method is preferable. A spin-coating method with a high is preferred. In the case of roll-to-roll coating, the substrate is coated with a composition for forming a photo-alignment film or the like to form an alignment film, and the composition for forming an optically anisotropic layer is continuously applied on the resulting alignment film. can also be applied to

[Drying of Optically Anisotropic Layer-Forming Composition]
Drying methods for removing the solvent contained in the optically anisotropic layer-forming composition include, for example, air drying, ventilation drying, heat drying, reduced pressure drying, and a combination thereof. Among them, natural drying or heat drying is preferable. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, even more preferably in the range of 50 to 130°C. The drying time is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes. The composition for forming a photo-alignment film and the aligning polymer composition can also be dried in the same manner.

[Polymerization of polymerizable liquid crystal compound]
As a method for polymerizing the polymerizable liquid crystal compound, photopolymerization is preferable. Photopolymerization is carried out by irradiating an active energy ray to a laminate obtained by coating a substrate or an alignment film with a composition for forming an optically anisotropic layer containing a polymerizable liquid crystal compound. As the active energy ray to be irradiated, the type of polymerizable liquid crystal compound contained in the dry film (especially the type of photopolymerizable functional group possessed by the polymerizable liquid crystal compound), and the photopolymerization initiator when a photopolymerization initiator is included. are appropriately selected according to the types and amounts thereof. Specifically, 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 used. Among them, ultraviolet light is preferable in that the progress of the polymerization reaction can be easily controlled and a photopolymerization apparatus that is widely used in the art can be used. It is preferable to select the type of the polar liquid crystal compound.

Examples of the light source of the active energy ray include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and wavelength ranges. LED light sources, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc., which emit light in the range of 380 to 440 nm can be used.

The ultraviolet irradiation intensity is usually 10 mW/cm ² to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably in the wavelength region effective for activating the cationic polymerization initiator or the radical polymerization initiator. The time for light irradiation is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, still more preferably 0.1 seconds. ~1 minute. When irradiated once or multiple times with such an irradiation intensity of ultraviolet rays, the integrated amount of light is usually 10 mJ/cm ² to 3,000 mJ/cm ² , preferably 50 mJ/cm ² to 2,000 mJ/cm ² , more preferably. 100 mJ/cm ² to 1,000 mJ/cm ² . If the integrated amount of light is below this range, curing of the polymerizable liquid crystal compound will be insufficient. Conversely, if the integrated amount of light is above this range, the elliptically polarizing plate including the optically anisotropic layer may be colored.

[Display device]
The present invention can provide a display device including the retardation plate of the present invention as one embodiment. Further, the display device may include the elliptically polarizing plate according to the embodiment.
The display device is a device having a display mechanism, and includes a light-emitting element or a light-emitting device as a light source. Examples of display devices include liquid crystal displays, organic electroluminescence (EL) displays, inorganic electroluminescence (EL) displays, touch panel displays, electron emission displays (field emission displays (FED, etc.), surface field emission displays). (SED)), electronic paper (display device using electronic ink or electrophoretic element), plasma display device, projection display device (grating light valve (GLV) display device, display device having digital micromirror device (DMD) etc.) and piezoelectric ceramic displays.
The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, a projection liquid crystal display device, and the like. These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images. In particular, an organic EL display device and a touch panel display device are preferable as the display device having the retardation layer and the polarizing layer according to the present invention.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. "%" and "parts" in Examples and Comparative Examples are "% by mass" and "parts by mass" unless otherwise specified.
The polymer films, devices and measurement methods used in Examples 1-6 and Comparative Examples 1-2 are as follows.
・ZF-14 manufactured by Nippon Zeon Co., Ltd. was used as the cycloolefin polymer (COP) film.
・AGF-B10 manufactured by Kasuga Denki Co., Ltd. was used as the corona treatment device.
- The corona treatment was performed once under the conditions of an output of 0.3 kW and a treatment speed of 3 m/min using the above corona treatment apparatus.
・SPOT CURE SP-7 with a polarizer unit manufactured by Ushio Inc. was used as a polarized UV irradiation device.
- LEXT manufactured by Olympus Corporation was used as a laser microscope.
- Unicure VB-15201BY-A manufactured by Ushio Inc. was used as the high-pressure mercury lamp.
・The in-plane retardation value and the axial angles of the retardation layer and the polarizing layer were measured using KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd.
・The optical properties of the polarizing layer were measured using UV-3150 manufactured by Shimadzu Corporation.
・The film thickness was measured using an ellipsometer M-220 manufactured by JASCO Corporation.

[Preparation of compositions for forming alignment layers A and B]
5 parts of a photo-alignable material having the following structure and 95 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80° C. for 1 hour to form alignment layers A and B. got The weight average molecular weight of the photo-alignment material used for the alignment layer A is 30000, and the molecular weight of the photo-alignment material used for the alignment film B is as shown in Table 1.

重合性液晶化合物Ａは、特開２０１０－３１２２３号公報に記載の方法で製造した。 ポリアクリレート化合物の量は、重合性液晶化合物Ａ１００部に対して０．０１部とした。
重合開始剤として、重合性液晶化合物Ａ１００部に対して、２－ジメチルアミノ－２－ベンジル－１－（４－モルホリノフェニル）ブタン－１－オン（イルガキュア３６９（Ｉｒｇ３６９）；ＢＡＳＦジャパン株式会社製）を６部添加した。
更に、固形分濃度が１３％となるようにＮ－メチル－２－ピロリドン（ＮＭＰ）を溶剤として添加し、８０℃で１時間攪拌することにより、位相差層形成用組成物を得た。 [Preparation of composition for forming retardation layer]
A polymerizable liquid crystal compound A having the following structure, a polyacrylate compound (leveling agent) (BYK-361N; manufactured by BYK-Chemie), and the following polymerization initiator are mixed as components to obtain a composition for forming a retardation layer. rice field.
Polymerizable liquid crystal compound A

Polymerizable liquid crystal compound A was produced by the method described in JP-A-2010-31223. The amount of the polyacrylate compound was 0.01 parts per 100 parts of the polymerizable liquid crystal compound A.
As a polymerization initiator, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369 (Irg369); manufactured by BASF Japan Ltd.) for 100 parts of the polymerizable liquid crystal compound A. was added in 6 parts.
Furthermore, N-methyl-2-pyrrolidone (NMP) was added as a solvent so that the solid content concentration was 13%, and the mixture was stirred at 80° C. for 1 hour to obtain a composition for forming a retardation layer.

[Preparation of Composition for Forming Polarizing Layer]
A composition for forming a polarizing layer was obtained by mixing the following components and stirring at 80° C. for 1 hour. As the dichroic dye, an azo dye described in Examples of JP-A-2013-101328 was used. Polymerizable liquid crystal compounds represented by formulas (1-6) and (1-7) were produced according to the method described in lub et al., Recl.Trav.Chim.Pays-Bas, 115, 321-328 (1996). .

７５部

２５部 Polymerizable liquid crystal compound:

75 copies

25 copies

化合物（１－５） ２．５部

化合物（１－１６） ２．５部

Dichroic dye 1:
Polyazo dye; Compound (1-8) 2.5 parts

Compound (1-5) 2.5 parts

Compound (1-16) 2.5 parts

polymerization initiator;
2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts leveling agent;
Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
1.2 parts solvent; o-xylene 250 parts

[Example 1]
[Production of Retardation Layer]
On COP film (ZF-14-50) manufactured by Nippon Zeon Co., Ltd., the composition for forming alignment layer A was applied with a bar coater, dried at 80 ° C. for 1 minute, and a polarized UV irradiation device (SPOT CURE SP-7; (manufactured by Ushio Inc.), polarized UV exposure was performed at an integrated light amount of 100 mJ/cm ² at an axis angle of 45°. The film thickness of the resulting alignment layer A was measured with an ellipsometer and found to be 100 nm.
Subsequently, on the alignment layer A, the previously prepared retardation layer-forming composition was applied using a bar coater and dried at 120° C. for 1 minute, followed by a high-pressure mercury lamp (Unicure VB-15201BY-A, Ushio Inc.) was used to irradiate ultraviolet rays from the side of the retardation layer on which the composition was applied (in a nitrogen atmosphere, an integrated amount of light at a wavelength of 313 nm: 500 mJ/cm ² ). A laminate including a retardation layer was formed.
Subsequently, the laminate including the obtained retardation layer was treated once under the conditions of an output of 0.3 kW and a treatment speed of 3 m/min using a corona treatment apparatus (AGF-B10, manufactured by Kasuga Denki Co., Ltd.). . A composition for forming an alignment layer B was applied to the corona-treated surface by a bar coater, dried at 80° C. for 1 minute, and then using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.). Polarized UV exposure was performed at an axial angle of 90° with an integrated light dose of 100 mJ/cm ² . When the film thickness of the resulting alignment layer B was measured with an ellipsometer, it was 150 nm.
After applying the composition for forming a polarizing layer using a bar coater, by drying for 1 minute in a drying oven set at 120 ° C., a dry coating film in which the polymerizable liquid crystal compound and the dichroic dye are oriented was obtained. After naturally cooling this dry coating film to room temperature, a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.) is used to irradiate ultraviolet rays (under nitrogen atmosphere, wavelength: 365 nm, integrated light intensity at wavelength 365 nm: 1000 mJ/cm ² ) to obtain an elliptically polarizing plate including a retardation layer and a polarizing layer, in which a polarizing layer was produced by polymerizing a polymerizable liquid crystal compound.

[Measurement of retardation value of elliptically polarizing plate]
When the in-plane retardation value of the obtained elliptically polarizing plate was measured at a wavelength of 450 nm, a wavelength of 550 nm, and a wavelength of 650 nm, the retardation value at each wavelength was Re (450) = 116 nm, Re (550) = 140 nm, Re (650)=144 nm, and the relationship between the in-plane retardation values is as follows.
Re(450)/Re(550)=0.83
Re(650)/Re(550)=1.03
(In the formula, Re (450) is the in-plane retardation value for light with a wavelength of 450 nm, Re (550) is the in-plane retardation value for light with a wavelength of 550 nm, and Re (650) is the in-plane retardation value for light with a wavelength of 650 nm. represents the phase difference value.)
That is, the retardation layer A had optical properties represented by the following formulas (1) to (3).
100 nm<Re(550)<160 nm (1)
Re(450)/Re(550)≤1.0 (2)
1.00≦Re(650)/Re(550) (3)
The slow axis direction of the retardation layer was 45°, and the absorption axis angle of the polarizing layer was 0°. Ideally, the angle formed by the slow axis of the retardation plate used in the circularly polarizing plate and the absorption axis of the polarizing plate should be 45°. It was found that the angle formed by the axes was 45° and no axial displacement occurred.

[Measurement of degree of polarization and single transmittance]
The degree of polarization and single transmittance of the obtained elliptically polarizing plate were measured as follows. The transmittance in the direction of the transmission axis (T ¹ ) and the transmittance in the direction of the absorption axis (T ² ) were measured using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a polarizer-equipped folder set. It was measured in a wavelength range of 380 to 680 nm in 2 nm steps by a beam method. Using the following formulas (p) and (q), calculate the single transmittance and degree of polarization at each wavelength. When the transmittance (Ty) and the visibility correction polarization degree (Py) were calculated, the single transmittance was 42% and the polarization degree was 97%.
Single transmittance (%) = (T ¹ + T ² )/2 (p)
Degree of polarization (%) = {(T ¹ −T ² )/(T ¹ +T ² )}×100 (q)

[Refractive index of elliptically polarizing plate]
The refractive index of each layer was measured according to JIS K7142 using a refractometer (“multi-wavelength Abbe refractometer DR-M4” manufactured by Atago Co., Ltd.), and the results were as follows.
Base material ... 1.53
Alignment film A ... 1.55
Retardation layer ... 1.62
Alignment film B...1.55
Polarizing layer: 1.54

[Examples 2 to 6]
An elliptical polarizing plate was prepared in the same manner as in Example 1 except that the thickness of the alignment layer B was adjusted by changing the thickness of the wire bar when the photo-alignment material was applied by a bar coater when the alignment layer B was formed. was made.

[Comparative Examples 1 and 2]
In the same manner as in Example 1, except that the thickness of the polarizing layer B was adjusted by changing the thickness of the wire bar when applying the photo-alignment material with a bar coater during the formation of the alignment layer B, a retardation layer was formed. and a circularly polarizing plate including a polarizing layer.

Table 1 shows the results of measuring the optical properties of the polarizing layers described in the above Examples and Comparative Examples.

The elliptically polarizing plates of Examples could be produced without the occurrence of misalignment of the axis of the polarizing layer and occurrence of orientation defects.

Claims (13)

An elliptical polarizing plate in which an orientation layer A, a retardation layer, an orientation layer B and a polarizing layer are provided in this order on a transparent substrate,
The optical axes of the polarizing layer and the retardation layer are not in a substantially parallel relationship,
The retardation layer is a film composed of a polymer of a polymerizable liquid crystal compound,
The alignment layer B is an alignment layer for forming a polarizing layer and is a film having a thickness of 150 nm to 800 nm,
The retardation layer and the alignment layer B are arranged adjacent to each other,
The polarizing layer is an elliptically polarizing plate in which a dichroic dye is oriented in a film composed of a polymer of a polymerizable liquid crystal compound, which is a thermotropic liquid crystal compound. 2. The elliptically polarizing plate according to claim 1, wherein the average refractive indices of the transparent substrate, the orientation layer A, the retardation layer, the orientation layer B and the polarizing layer are all in the range of 1.4 to 1.7. 3. The elliptically polarizing plate according to claim 1, wherein the difference in refractive index between adjacent layers is 0.2 or less. The elliptically polarizing plate according to any one of claims 1 to 3, wherein the angle formed by the optical axes of the polarizing layer and the retardation layer is in the range of 40° to 50°. 5. The elliptically polarizing plate according to claim 1, wherein both the alignment layer A and the alignment layer B are photo-alignment films. 6. The elliptically polarizing plate according to claim 1, wherein the alignment layer A and the alignment layer B are photo-alignment films containing cinnamoyl groups. The elliptically polarizing plate according to any one of claims 1 to 6, wherein the alignment layer A and the alignment layer B are photo-alignment films containing a resin having a weight average molecular weight of 20,000 to 50,000. The elliptically polarizing plate according to any one of claims 1 to 7, wherein the polarizing layer is a film composed of a polymer in a smectic liquid crystal state. The elliptically polarizing plate according to any one of claims 1 to 8, wherein the dichroic dye is an azo dye. The elliptically polarizing plate according to any one of claims 1 to 9, wherein the retardation layer satisfies all of the following formulas.
100 nm<Re(550)<160 nm (1)
Re(450)/Re(550)≤1.0 (2)
1.00≦Re(650)/Re(550) (3)
(Re(450), Re(550), and Re(650) represent in-plane retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.) A liquid crystal display comprising the elliptically polarizing plate according to any one of claims 1 to 10. An organic EL display device comprising the elliptically polarizing plate according to any one of claims 1 to 11. on a transparent substrate,
Step (1) of applying a composition containing an alignment material A and a solvent, drying the composition, and then irradiating polarized UV to form an alignment layer A;
A step (2) of forming a retardation layer by applying a composition containing a polymerizable liquid crystal compound, a polymerization initiator and a solvent onto the alignment layer A, drying and then irradiating UV to polymerize the composition in a liquid crystal state; ,
A step (3) of applying a composition containing an alignment material B and a solvent onto the retardation layer , drying the composition and then irradiating it with polarized UV to form an alignment layer B;
A composition containing a polymerizable liquid crystal compound that is a thermotropic liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent is applied onto the alignment layer B, dried and then irradiated with UV to polymerize in a liquid crystal state. A step (4) of forming a polarizing layer in
has
The alignment layer B is a film having a thickness of 150 nm to 800 nm,
A method for producing an elliptically polarizing plate.