TW201348762A - Circular polarizing plate and its manufacturing method - Google Patents

Abstract

This invention provides a circular polarizing plate which is thin and has excellent anti-reflection performance, its manufacturing method, and a display device equipped with the circular polarizing plate. This invention provides a circular polarizing plate and its (continuous) manufacturing method and a display device equipped with the circular polarizing plate, an organic EL display element and other display elements. The aforesaid circular polarizing plate is characterized by being sequentially provided with: a liquid crystal phase difference layer formed by a composition for forming a liquid crystal phase difference layer comprising a polymeric liquid crystal compound; a phase difference layer comprising a phase difference film formed by extending the polymeric film; and a polarizing layer formed by a composition for forming a polarizing layer comprising a dichromatic pigment.

Description

Circular polarizing plate and manufacturing method thereof

The present invention relates to a circularly polarizing plate, a method of manufacturing the same, and the like.

A wide-band circular polarizing plate (circular polarizing plate) used in a liquid crystal display device is usually manufactured by using a polarizing film containing iodine-dyed polyvinyl alcohol, a 1⁄2 wavelength plate, and a 1⁄4 wavelength plate. For example, the retardation axis of the 1/2 wavelength plate and the 1/4 wavelength plate and the angle formed by the absorption axis of the polarizing film are 15° and 75°, respectively, and laminated by an adhesive or an adhesive. However, the circular polarizing plate cannot avoid the case where the total thickness thereof is thick, and is not suitable for a circularly polarizing plate used in a current display device which requires further thinning. Therefore, an attempt is made to avoid a laminate due to bonding, and to form a polarizing film, a 1/2 wavelength plate, or a quarter-wave plate by a coating method, and to manufacture a thin circular polarizing plate.

For example, Patent Document 1 discloses a circularly polarizing plate in which a polarizing element formed of a substance having a thermal liquid crystal property or a liquid liquid crystal property and a retardation layer (positive wavelength dispersing film) are laminated.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-251288

However, according to the study by the inventors of the present invention, it has been found that the circularly polarizing plate described in Patent Document 1 has insufficient antireflection performance as a circularly polarizing plate.

The invention includes the following invention.

[1] A circularly polarizing plate comprising: a liquid crystal phase difference layer formed of a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound; and a retardation layer comprising a polymer film extending A retardation film formed; and a polarizing layer formed of a composition for forming a polarizing layer containing a dichroic dye.

[2] The circularly polarizing plate of [1], wherein the composition for forming a polarizing layer further comprises a polymerizable liquid crystal compound.

[3] The circularly polarizing plate according to [2], wherein the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is a compound exhibiting a liquid crystal state of a smectic phase.

[4] The circularly polarizing plate according to any one of [1] to [3] wherein the retardation layer is a 1/2 wavelength plate, and the liquid crystal phase difference layer is a 1/4 wavelength plate.

[5] The circularly polarizing plate according to any one of [1] to [4] wherein the polarizing layer is a Bragg peak obtained in an X-ray diffraction measurement.

[6] The circularly polarizing plate according to any one of [1] to [5] wherein a first alignment layer is provided between the liquid crystal phase difference layer and the retardation layer, and the phase difference layer and the polarized light are A second alignment layer is disposed between the layers.

[7] The circularly polarizing plate of [6], wherein the liquid crystal phase difference layer is formed by applying a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound to the first alignment layer.

[8] The circularly polarizing plate according to [6] or [7], wherein the polarizing layer is formed by applying a composition for forming a polarizing layer containing a dichroic dye to the second alignment layer.

[9] The circularly polarizing plate according to any one of [6], wherein the first alignment layer and/or the second alignment layer is a composition for forming an alignment layer containing a photoinduced alignment material. Former.

[10] A method for producing a circularly polarizing plate, which has the following preparation steps, liquid crystal phase a step of forming a retardation layer and a step of forming a polarizing layer, a preparation step of preparing a retardation film formed by stretching the polymer film, and a step of forming a retardation layer of liquid crystal by coating a surface of the retardation film with a polymerizable liquid crystal compound a liquid crystal phase difference layer forming composition, a step of forming a liquid crystal phase difference layer by coating a coating film for forming a liquid crystal phase difference layer; and a polarizing layer forming step of coating the other surface of the retardation film with two colors A composition for forming a polarizing layer of a dye, a step of forming a polarizing layer from a coating film for forming a polarizing layer.

[11] A display device comprising the circular polarizing plate and the display element according to any one of [1] to [9].

[12] The display device according to [11], comprising a liquid crystal cell, an organic EL (Electroluminescence) element, or a touch panel as a display element.

According to the present invention, it is possible to provide a circular polarizing plate which is thin and has excellent antireflection performance, a method for producing the circular polarizing plate, and a display device including the circular polarizing plate.

1‧‧‧ phase difference layer

2‧‧‧Liquid phase difference layer

2A‧‧‧Alignment layer

3‧‧‧ polarizing layer

3A‧‧‧Alignment layer

30‧‧‧EL display device

33‧‧‧Substrate

34‧‧‧Interlayer insulating film

35‧‧‧pixel electrode

36‧‧‧ organic functional layer

37‧‧‧Cathode electrode

38‧‧‧Drying agent

39‧‧‧ Sealing cover

40‧‧‧film transistor

41‧‧‧ blocking wall

42‧‧‧film sealing film

100‧‧‧this circular polarizer

110‧‧‧ phase difference film

120‧‧‧1st laminate

140‧‧‧2nd layer body

150‧‧‧3rd layer body

210‧‧‧ Volume 1

210A‧‧‧core

211A‧‧‧ Coating device

211B‧‧‧ Coating device

212A‧‧‧Drying device

212B‧‧‧Drying device

213A‧‧‧Lighting device

213B‧‧‧Lighting device

220‧‧‧ Volume 2

220A‧‧‧core

300‧‧‧Auxiliary volume

1(A1) and (A2) are schematic views showing a cross-sectional structure of a circularly polarizing plate of the present invention.

Fig. 2 is a schematic view showing an example of a method for producing a continuous circular polarizing plate of the present invention.

Fig. 3 is a schematic view showing a cross-sectional configuration of an EL display device using the circularly polarizing plate of the present invention.

Fig. 4 is a schematic view showing a cross-sectional configuration of an EL display device using the circularly polarizing plate of the present invention.

<Circular polarizer>

The circularly polarizing plate of the present invention (hereinafter sometimes referred to as "the present polarizing plate") is characterized in that a liquid crystal phase difference layer formed of a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound, a retardation layer including a retardation film formed by extending a polymer film, and a polarizing layer are provided in this order. It is formed of a composition for forming a polarizing layer containing a dichroic dye.

In the configuration of the present circular polarizing plate, it is preferable that the retardation layer is a half-wavelength plate, and the liquid crystal phase difference layer is a quarter-wavelength plate. First, a method of manufacturing the present circular polarizing plate will be described.

Fig. 1 is a schematic view showing the configuration of the present circular polarizing plate. The configuration of Fig. 1 (A1) relates to the present circular polarizing plate 100, which is provided with a liquid crystal phase difference layer 2, a retardation layer 1, and a polarizing layer 3 in this order.

The configuration of Fig. 1 (A2) is a preferred configuration of the circularly polarizing plate, and the polarizing plate 100 is further provided with an alignment layer 2A between the liquid crystal phase difference layer 2 and the retardation layer 1 and a polarizing layer. An alignment layer 3A is provided between the phase difference layer 1 and the phase difference layer 1.

<Manufacturing method of the present circular polarizing plate (hereinafter, sometimes referred to as "this manufacturing method")>

The manufacturing method of the circular polarizing plate generally has the following preparation steps, a liquid crystal phase difference layer forming step, and a polarizing layer forming step.

a preparation step of preparing a retardation film formed by stretching a polymer film; and a liquid crystal phase difference layer forming step of applying a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound on one surface of the retardation film, a step of forming a liquid crystal phase difference layer by coating a liquid crystal phase difference layer forming coating film; and a polarizing layer forming step of applying a polarizing layer forming composition containing a dichroic dye to the other surface of the retardation film And a step of forming a polarizing layer from a coating film for forming a polarizing layer formed by coating.

Preparation step: The retardation film prepared in the preparation step of the present production method is formed by stretching a polymer film. The polymer film preferably has a film that is transparent to light, particularly visible light. The term "transparency" refers to a characteristic that the transmittance of light passing through a wavelength of 380 to 780 nm is 80% or more. Examples of the polymer constituting the polymer film include polyethylene, polypropylene, and Polyolefin such as olefinic polymer; cyclic olefin resin; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; triacetyl cellulose, diethyl cellulose and acetic acid Cellulose esters such as cellulose propionate; polyethylene naphthalate; polycarbonate; polyfluorene; polyether oxime; polyether ketone; polyphenylene sulfide and polyphenylene ether. In terms of easiness of obtaining or higher transparency, a polymer film comprising a cellulose ester, a cyclic olefin resin, or a polycarbonate is preferable.

In particular, a polymer film containing a cyclic olefin resin (hereinafter sometimes referred to as a cyclic olefin resin film) is particularly preferable in terms of easy control of phase difference.

The cyclic olefin resin can be easily obtained from the market. Examples of the commercially available cyclic olefin resin include "Topas" [Ticona Co., Ltd.]; "Arton" [JSR (share)]; "Zeonor (ZEONOR)" and "Zeonex (ZEONEX)" [Japan Zeon] (shares)]; "Apel" [Mitsui Chemicals Co., Ltd.] and so on. The cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by a known film forming method such as a solvent casting method or a melt extrusion method. Further, a cyclic olefin resin film which has been commercially available in the form of a film can also be used. Examples of the commercially available cyclic olefin-based resin film include "S-SINA" and "SCA40" [Sekisui Chemical Industry Co., Ltd.]; "Zeonor Film" [Optronics (share)]; "Arton Film" [JSR (shares)] and so on.

Cyclic olefin resin Alkene or polycyclic drop A polymer or copolymer of a cyclic olefin such as an olefinic monomer. The polymer or copolymer of the cyclic olefin may also partially comprise an open-loop portion, or may be hydrogenated. Further, the cyclic olefin-based resin may be a cyclic olefin and a chain olefin or an ethylated aromatic compound (styrene), for example, in terms of not impairing transparency or not significantly increasing hygroscopicity. Copolymers. Further, the cyclic olefin resin may have a polar group introduced into the molecule.

Examples of the chain olefin include ethylene and propylene. Further, examples of the vinylated aromatic compound include styrene, α-methylstyrene, and alkyl-substituted styrene. The content ratio of the structural unit derived from the cyclic olefin in the above copolymer is usually 50 mol% or less, preferably 15 to 50 mol%, based on the total structural unit of the cyclic olefin resin. When the cyclic olefin resin is a terpolymer obtained from a cyclic olefin, a chain olefin, or an ethylene compound, the content ratio of the structural unit derived from the chain olefin is relative to the cyclic olefin resin. The total structural unit is usually from 5 to 80 mol%, and the content of the structural unit derived from the vinylated aromatic compound is usually from 5 to 80 mol%. The cyclic olefin-based resin of such a terpolymer has an advantage that the amount of the expensive cyclic olefin can be relatively reduced when the cyclic olefin-based resin is produced.

As a method of producing a retardation film from a polymer film, a method of extending a polymer film is exemplified. As a method of extension, the following methods are mentioned, for example.

A roll of a polymer film (wound body) is wound up on a preparation roll, a polymer film is continuously wound up from the take-up body, and the rolled-out polymer film is conveyed to a heating furnace.

The set temperature of the heating furnace is usually set to the range of the glass transition temperature (°C) to the [glass transition temperature +100] (°C) of the polymer film, preferably set to the glass transition temperature (°C) to [glass transition temperature +50 ] (°C) range.

In the heating furnace, when extending in the direction perpendicular to the traveling direction of the polymer film or in the direction orthogonal to the traveling direction, the conveying direction or the tension is adjusted and inclined at an arbitrary angle to perform uniaxial or biaxial stretching.

The magnification of the extension is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.

Further, the method of extending obliquely is not particularly limited as long as the alignment axis can be continuously inclined to a desired angle, and a known extension method can be employed. For example, the method described in Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei.

The stretching ratio may be determined according to the alignment birefringence of the resin constituting the polymer film. The retardation value obtained by multiplying the birefringence Δn generated by the alignment and the thickness d after the extension is a wavelength of 550 nm, and if it is in the range of 200 to 320 nm, the obtained retardation film can be used as a reference. 1/2 wavelength plate.

The 1⁄2 wavelength plate is preferable as the phase difference layer of the present polarizing plate.

The thickness of the polymer film is preferably as thin as possible in terms of the degree of practical treatment and sufficient transparency, but if it is too thin, the strength is lowered and the workability is poor. . The appropriate thickness of the polymer film is usually 5 to 300 μm, preferably 20 to 200 μm, and more preferably 20 to 100 μm. The thickness of the retardation film after stretching is determined by the thickness or the stretching ratio of the polymer film before stretching.

In the liquid crystal phase difference layer forming step, the liquid crystal phase difference layer is formed of a liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound, and is preferably formed by coating a liquid crystal phase difference layer on the retardation film. A film formed by a coating film for forming a liquid crystal phase difference layer obtained by using a composition.

Examples of the polymerizable liquid crystal compound contained in the liquid crystal retardation layer-forming composition include Formula (I), Formula (II), Formula (III), Formula (IV), Formula (V), and Formula (VI). ) Compounds represented separately.

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -B ¹⁶ -E ¹² -B ¹⁷ -P ¹² (I)

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -F ¹¹ (II)

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -E ¹² -B ¹⁷ -P ¹² (III)

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -F ¹¹ (IV)

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -E ¹² -B ¹⁷ -P ¹² (V)

P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -F ¹¹ (VI)

[wherein, P ¹¹ and P ¹² represent a polymerizable group.

A ¹¹ to A ¹⁴ represent a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may also pass through a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitrate The hydrogen group contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted by a fluorine atom. Further, -CH ₂ - constituting the divalent alicyclic hydrocarbon group may be substituted by -O-, -S- or -NR ⁵⁰ -. R ⁵⁰ is an alkyl group having 1 to 6 carbon atoms or a phenyl group.

B ¹¹ and B ¹⁷ represent -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ¹⁶ -, -NR ¹⁶ -CO-, -CO -, -CS- or single button. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

B ¹² to B ¹⁶ each independently represent -C≡C-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, -C(=O)-O-, - OC(=O)-, -OC(=O)-O-, -N=CH-, -N=N-, -C(=O)-NR ¹⁶ -, -NR ¹⁶ -C(=O)- , -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH-,- CR ^a =CR ^b -, -C≡C-, -CR ^a =N- or a single bond. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

E ¹¹ and E ¹² represent an alkanediyl group having 1 to 20 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted by an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group. It can also be substituted by a halogen atom. Further, -CH ₂ - constituting the alkanediyl group may be substituted by -O-, -S-, -NH- or -CO-.

F ¹¹ represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, a methylol group, and a methyl group. And a sulfo group (-SO ₃ H), a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and the -CH ₂ - contained in the alkyl group and the alkoxy group may be substituted by -O-. ]

The carbon number of the divalent aromatic hydrocarbon group and the divalent alicyclic hydrocarbon group represented by A ¹¹ to A ¹⁴ is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, still more preferably 5 or 6. As A ¹¹ , a cyclohexane-1,4-diyl group and a 1,4-phenylene group are preferable.

The alkanediyl group having 1 to 20 carbon atoms represented by E ¹¹ and E ¹² is preferably a linear alkyl group having 1 to 12 carbon atoms. The -CH ₂ - constituting the alkanediyl group having 1 to 12 carbon atoms may also be substituted by -O-.

Specific examples thereof include a methylene group, an ethyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6 group. -diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,9-diyl, decane-1,10-diyl, undecane-1, a linear alkanediyl group having 1 to 12 carbon atoms such as 11-diyl and dodecane-1,12-diyl; -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - and -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - Wait.

The polymerizable group represented by P ¹¹ and P ¹² is preferably a radical polymerizable group or a cationic polymerizable group in terms of a polymerization reaction, and is easy to handle, and the polymerizable liquid crystal compound itself is easy to manufacture. In other words, the polymerizable group is preferably a group represented by the following formula (P-11) to formula (P-15).

In the formulae (P-11) to (P-15), R ¹⁷ to R ²¹ each independently represent an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

Specific examples of the group represented by the formula (P-11) to the formula (P-13) include the groups represented by the following formulas (P-16) to (P-20).

P ^{11 is} preferably a group represented by the formula (P-14) to the formula (P-20), more preferably a vinyl group, a p-nonyl group, an epoxy group or an oxetanyl group.

The group represented by P ¹¹ -B ¹¹ - is further preferably an acryloxy group or a methacryloxy group.

Specific examples of the polymerizable liquid crystal compound include: "3.8.6 Network (completely cross-linked type)" and "6.5" of a liquid crystal handbook (edited by the Liquid Crystal Handbook Compilation Committee, Maruzen (share) issued on October 30, 2000). .1. A compound having a polymerizable group among the compounds described in the "liquid crystal material b. polymerizable nematic liquid crystal material". As the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal phase difference layer, a plurality of different polymerizable liquid crystal compounds may be used in combination.

Specific examples of the polymerizable liquid crystal compound contained in the liquid crystal retardation layer-forming composition include, for example, the following formulas (I-1) to (I-4) and (II-1) to (II-). 4), formula (III-1) to formula (III-26), formula (IV-1) to formula (IV-19), formula (V-1) to formula (V-2), formula (VI-1 The compound represented by the formula (VI-6) and the like. Where k1 and k2 represent an integer from 2 to 12. These polymerizable liquid crystal compounds are preferred because they are easy to synthesize and are easily available.

The composition for forming a liquid crystal phase difference layer contains a solvent which dissolves the polymerizable liquid crystal compound.

As the solvent, the solubility to the polymerizable liquid crystal compound can be selected to be sufficient, and The polymerization reaction of the polymerizable liquid crystal compound is inert. Examples of such a solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate and acetic acid; Ester ester solvents such as butyl ester, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate and ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2- Ketone solvents such as 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; tetrahydrofuran and dimethoxyethane Ether solvent; chlorine-substituted hydrocarbon solvent such as chloroform or chlorobenzene; These solvents may be used singly or in combination.

The content ratio of the polymerizable liquid crystal compound in the composition for forming a liquid crystal phase difference layer is usually from 1 to 70% by mass, preferably from 10 to 40% by mass, based on the solid content of the liquid crystal retardation layer-forming composition. When the content ratio of the polymerizable liquid crystal compound is within the above range, it is preferable that no so-called dripping occurs during coating or that unevenness occurs in the obtained liquid crystal phase difference layer. The solid content component herein refers to the total amount of components obtained by removing the solvent from the composition for forming a liquid crystal phase difference layer. In the case where the liquid crystal phase difference layer-forming composition contains a plurality of polymerizable liquid crystal compounds, the total content ratio thereof may be within the above range.

The liquid crystal phase difference layer forming composition preferably contains a polymerization initiator. The polymerization initiator is a compound which can initiate polymerization of the polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator is preferred in terms of the polymerization initiation reaction under low temperature conditions. Specifically, a compound which generates an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those which generate active radicals by the action of light are more preferred.

Examples of the polymerization initiator include a benzoin compound, a benzophenone compound, a phenylalkyl ketone compound, a decyl phosphine oxide compound, and the like. Compounds, strontium salts and strontium salts.

As the benzoin compound, for example, benzoin, benzoin methyl ether, rest Aromatic ether, benzoin isopropyl ether and benzoin isobutyl ether.

Examples of the benzophenone compound include benzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, and 4-benzylidene-4'-methyldiphenylsulfide. Ether, 3,3',4,4'-tetrakis(t-butylperoxycarbonyl)benzophenone and 2,4,6-trimethylbenzophenone.

Examples of the phenylalkyl ketone compound include diethoxyacetophenone and 2-methyl-2- Lolinyl-1-(4-methylthienyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4- Polinylphenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1 -ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl An oligomer of keto-1-[4-(1-methylvinyl)phenyl]propan-1-one or the like.

Examples of the fluorenylphosphine oxide compound include 2,4,6-trimethylbenzimidyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzylidene)phenylphosphine oxide. .

As three The compound may, for example, be 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-tri , 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-three 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)vinyl]-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-three , 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)vinyl]-1,3,5-three And 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)vinyl]-1,3,5-tri Wait.

A photopolymerization initiator can also be used by a commercial one. Examples of commercially available photopolymerization initiators include "Irgacure 907", "Irgacure 184", "Irgacure 651", "Irgacure 819", "Irgacure 250", and "Irgacure 369" (Ciba Japan). "Seikuol BZ", "Seikuol Z", "Seikuol BEE" (Seiko Chemicals Co., Ltd.); "Kayacure BP100" (Nippon Chemicals Co., Ltd.); "Kayacure UVI-6992" (manufactured by Dow); "Adeka Optomer SP-152", "Adeka Optomer SP-170" (ADEKA (share)); "TAZ-A", "TAZ-PP" (Nihon Siber Hegner); and "TAZ-104" (Sanwa Chemical Company) and so on.

When the liquid crystal phase difference layer is formed from the composition for forming a liquid crystal phase difference layer, the composition for forming a liquid crystal phase difference layer is applied to the retardation layer containing the retardation film to form a coating film for forming a liquid crystal phase difference layer. In this case, it is preferred that an alignment layer is formed on the surface of the retardation film on which the retardation layer is to be formed, and a liquid crystal phase difference layer is formed thereon. When the liquid crystal phase difference layer forming composition is applied onto the alignment layer formed on the retardation film to form a coating film for forming a liquid crystal phase difference layer, the alignment layer can be formed to have a desired retardation. The phase difference liquid crystal phase difference layer.

It is preferable that the alignment layer has solvent resistance which is not dissolved by application of a composition for forming a liquid crystal phase difference layer or the like. Moreover, it is preferable to remove the solvent from the coating film for forming a liquid crystal phase difference layer formed by the composition for forming a liquid crystal phase difference layer, or to align the polymerizable liquid crystal compound in the coating film in a desired direction. The heat treatment has heat resistance.

Examples of the alignment polymer contained in the alignment layer include polyamine or gelatin having a guanamine bond in the molecule, polyimine having a quinone bond in the molecule, and a hydrolyzate which is a hydrolyzate. Amine acid, polyvinyl alcohol, alkyl modified polyvinyl alcohol, polypropylene decylamine, poly A polymer such as azole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylate. Among them, polyvinyl alcohol is preferred. The alignment polymers may be used singly or in combination.

The alignment layer can be formed on the retardation film by applying the alignment polymer to the retardation film in the form of a composition for forming an alignment layer which is dissolved in a solvent. The solvent to be contained in the composition for forming an alignment layer is, for example, a solvent which is included in the composition for forming a liquid crystal phase difference layer, and which dissolves the alignment polymer sufficiently.

As the composition for forming an alignment layer, a commercially available one can also be used. Examples of the commercially available composition for forming an alignment layer include Sunever (registered trademark, manufactured by Nissan Chemical Industries Co., Ltd.), Optomer (registered trademark, manufactured by JSR Co., Ltd.), and the like.

As a method of forming an alignment layer on the retardation film, for example, a composition for forming an alignment layer is applied onto the retardation film, followed by annealing. The thickness of the alignment layer obtained in this manner is usually from 10 nm to 10,000 nm, preferably from 10 nm to 1000 nm.

In order to impart an alignment restriction force to the alignment layer, rubbing (friction method) may be performed as needed. By imparting an alignment limiting force, the polymerizable liquid crystal compound can be aligned in a desired direction.

As a method of imparting the alignment regulating force by the rubbing method, for example, a method of preparing a laminated body in which a coating film for forming an alignment layer is formed on a retardation film is prepared by preparing a rubbing roller that is wound with a rubbing cloth and rotating It is placed on the stage and conveyed to the rotating rubbing roll, whereby the coating film for forming the alignment layer is brought into contact with the rotating rubbing roll.

Further, the alignment layer is also formed of a light-induced alignment material that generates an alignment restricting force by light irradiation (hereinafter, an alignment layer formed by light-illuminating the light-induced alignment material may be referred to as a photo alignment layer). ). The photo-alignment-aligning material is formed into a photo-alignment-inducing layer, and is irradiated with polarized light (preferably polarized ultraviolet (UV)) to impart an alignment regulating force to the photo-alignment-inducing layer, thereby forming an alignment layer. Therefore, by selecting the direction of the polarized light to be irradiated, the alignment direction of the polymerizable liquid crystal compound can be freely controlled, which is more preferable. The light-inducing alignment material comprises a polymer or monomer having a photoreactive group. Hereinafter, a composition for forming an alignment layer containing a photoinduced alignment material and a solvent may be referred to as a composition for forming a photo alignment layer. The photoreactive group refers to a group which generates a liquid crystal alignment ability by irradiation of light (light irradiation). Specifically, a photoreactor which is an origin of liquid crystal alignment ability which generates an alignment induction or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, which are generated by irradiation of light, is generated. Among the photoreactive groups, those having excellent alignment properties and maintaining the liquid crystal state at the time of forming the polarizing layer are preferably those which utilize a dimerization reaction or a photocrosslinking reaction. As the photoreactive group which can cause the reaction as described above, it is preferably one having an unsaturated bond, especially a double bond, and particularly preferably having a carbon-carbon double bond (C=C bond) and a carbon-nitrogen double bond. Key (C=N bond), nitrogen-nitrogen double bond (N=N bond), and carbon-oxygen double bond (C=O bond) A photoreactive group of at least one of the group consisting of.

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyalkenyl group, a decyl group, a carbazolyl group, a heterofluorenyl group, a chalcone group, and a cinnamyl group. Examples of the photoreactive group having a C=N bond include a group having a structure such as an aromatic Schiff base and an aromatic fluorene. Examples of the photoreactive group having an N=N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, or the like, or an oxyazobenzene group. Basic structure. Examples of the photoreactive group having a C=O bond include a benzophenone group, a coumarin group, a fluorenyl group, and a maleimine group. These groups may also have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or a halogenated alkyl group.

Among them, a photoreactive group capable of photodimerization reaction is preferred, and the amount of polarized light required for cinnamyl sulfhydryl and chalcone based on photoalignment is relatively small, and it is easy to obtain thermal stability or excellent stability over time. The light alignment layer is preferred. Further, as the polymer having a photoreactive group, it is particularly preferred that the terminal portion of the side chain of the polymer forms a cinnamic acid structure having a cinnamic acid structure.

The solvent of the composition for forming a photo-alignment layer is exemplified as a solvent which is sufficient to dissolve the photo-induced alignment material among the examples of the solvent contained in the composition for forming a liquid crystal phase difference layer.

The concentration of the photoreactive group-containing polymer or monomer relative to the photo-alignment layer-forming composition can be appropriately adjusted depending on the type of the photoreactive group-containing polymer or monomer or the thickness of the photo-alignment layer to be produced. The solid content concentration is preferably at least 0.2% by mass, and more preferably 0.3 to 10% by mass. Further, the photo-alignment layer-forming composition may contain a polymer material such as polyvinyl alcohol or polyimine or a photosensitizer in a range in which the characteristics of the photo-alignment layer are not significantly impaired.

As a method of applying the composition for forming an alignment layer or the composition for forming an optical alignment layer to a retardation film, a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, and a dressing are used. Known methods such as a coating method such as a coating method or a printing method such as a soft printing method law.

The method of forming the photoalignment layer by the photoalignment inducing layer formed by coating the composition for forming a photoalignment layer on the retardation film, for example, the following method is mentioned.

First, the coating film obtained by coating the composition for forming a light alignment layer is annealed to remove the solvent contained in the coating film. The temperature and time in the annealing treatment are appropriately determined depending on the type of the solvent or the like contained in the composition for forming the photoalignment layer.

The alignment restriction force can be imparted by irradiating the light-aligning evoked layer after the annealing treatment with polarized light (preferably polarized UV). By such polarized light irradiation, an alignment layer having an alignment regulating force in a desired alignment direction can be obtained. In the present invention, it is necessary to perform polarized light irradiation in a direction in which the retardation axis of the retardation film is not horizontal or non-perpendicular to the substrate, and is preferably substantially 60° with respect to the retardation axis of the retardation film or Irradiation was carried out in the direction of 60°.

The thickness of the alignment layer thus formed is determined such that the total thickness of the circular polarizing plate does not significantly exceed the following range, and is usually 10 to 1000 nm. The thickness of the alignment layer can be controlled by the thickness of the coating film formed by coating the composition for forming an alignment layer. The thickness of the alignment layer can be determined by measurement using an interference film thickness meter, a laser microscope, or a stylus type film thickness meter.

Then, a composition for forming a liquid crystal phase difference layer is applied onto the formed alignment layer. The coating method is the same as that exemplified as the coating method of the composition for forming an alignment layer.

Then, the solvent contained in the coating film for forming a liquid crystal phase difference layer formed by coating on the alignment layer is dried and removed to form a dried film. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.

Then, the dried film is irradiated with light to polymerize the polymerizable liquid crystal compound in the dried film to form a liquid crystal phase difference layer. The light to be irradiated to the dried film is based on the kind of the polymerizable liquid crystal compound contained in the dried film or the type and amount of the polymerization initiator. It is suitably selected from visible light, ultraviolet light, laser light or active electron beam. Among these, ultraviolet light is preferred in terms of the ease of controlling the progress of the polymerization reaction or the use of a wide range of users in the field as a device for photopolymerization. Therefore, the type of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the liquid crystal retardation layer-forming composition is selected so that the polymerization can be carried out by ultraviolet light.

The thickness of the liquid crystal phase difference layer thus formed is determined such that the total thickness of the circularly polarizing plate does not significantly exceed the following range, and is usually 0.5 to 5.0 μm. The thickness of the liquid crystal phase difference layer can be controlled by the thickness of the coating film for forming a liquid crystal phase difference layer formed by coating a composition for forming a liquid crystal phase difference layer or the birefringence of a polymerizable liquid crystal compound. Rate is controlled.

a polarizing layer forming step: secondly, a laminated body having a liquid crystal phase difference layer and a retardation film laminated thereon, preferably a liquid crystal phase difference layer, an alignment layer, and a retardation film layer of the retardation film (ie, A polarizing layer is formed on the opposite side to the surface on which the liquid crystal phase difference layer is provided.

First, a composition for forming a polarizing layer used for forming a polarizing layer will be described. The composition for forming a polarizing layer contains a dichroic dye. The dichroic dye refers to a dye having a property in which the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. As long as it has such a property, the dichroic dye may be a dye which may be a pigment or a mixture of a plurality of compounds.

The dichroic dye preferably has a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Examples of such a dichroic dye include acridine dyes. A pigment, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone pigment, etc., among which an azo dye is preferred. Examples of the azo dye include a monoazo dye, a disazo dye, a trisazo dye, a tetrazo pigment, and a quinone azo dye, and a disazo dye and a trisazo dye are preferable.

The azo dye is, for example, a compound represented by the formula (1) (hereinafter, sometimes referred to as It is "compound (1)").

A ¹ (-N=NA ² ) _p -N=NA ³ (1)

In the formula (1), A ¹ and A ³ each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. A ² represents a para-phenyl group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent or a divalent heterocyclic group which may have a substituent. p represents an integer from 1 to 4. In the case where p is an integer of 2 or more, the plurality of A ^{2 's} may be the same or different from each other. ]

Examples of the monovalent heterocyclic group include quinoline, thiazole, benzothiazole, thienothiazole, imidazole, and benzimidazole. Oxazole and benzo A group in which a hydrogen atom is removed from a heterocyclic compound such as azole. The group after removing two hydrogen atoms from the heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of the heterocyclic compound are as described above.

And a phenyl group, a naphthyl group, and a monovalent heterocyclic group in A ¹ and A ³ , and a substituent which the phenyl group, the naphthalene-1,4-diyl group and the divalent heterocyclic group in A ² have, The alkyl group having 1 to 4 carbon atoms; the alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; the fluoroalkyl group having a carbon number of 1 to 4 such as a trifluoromethyl group; Substituted; nitro; halogen atom; substituted or unsubstituted amine group such as amine group, diethylamino group and pyrrolidinyl group (so-called substituted amino group means 1 or 2 carbon number 1 to 6) The alkyl group of the alkyl group or the two substituted alkyl groups are bonded to each other to form an amine group having a C 2-8 alkanediyl group. The unsubstituted amine group is -NH ₂ ).

Among the compounds (1), preferred are the compounds represented by the following formulas (1-1) to (1-6).

In the formulae (1-1) to (1-6), R ¹ to R ²⁰ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, and a nitrate. A group, a substituted or unsubstituted amine group (substituted amino group and unsubstituted amine group are as defined above), a chlorine atom or a trifluoromethyl group.

N1 to n4 independently represent an integer of 0 to 3.

When n1 is 2 or more, a plurality of R ^{2 's} may be the same or different. When n 2 is 2 or more, a plurality of R ^{6 's} may be the same or different, and when n 3 is 2 or more, the plural R ⁹ may be the same or different from each other, and when n 4 is 2 or more, a plurality of R ¹⁴ may be the same or different from each other. ]

In addition to the dichroic dye, the composition for forming a polarizing layer preferably contains a polymerizable liquid crystal compound. The definition of the polymerizable liquid crystal compound is the same as that of the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal phase difference layer, but the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is preferably a liquid crystal which exhibits a phase of the layer. The state, and further preferably, the liquid crystal state showing the high-order layer phase.

The high-order stratigraphic phase, the stratigraphic column B phase, the smectic phase D phase, the smectic phase E phase, the smectic F phase, the smectic G phase, the smectic H phase, the smectic phase I phase, the smectic phase J phase, the smectic column The K phase and the smectic L phase, and more preferably the smectic B phase, the smectic F phase, and the smectic phase I phase. When the stratifized liquid crystal phase exhibited by the polymerizable liquid crystal compound is such a high-order smectic phase, a polarizing layer having a higher degree of alignment can be formed, which is particularly preferable. Further, such a polarizing film having a high degree of alignment can obtain a Bragg peak derived from a hexagonal phase or a crystal-equivalent high-order structure in an X-ray diffraction measurement. The Bragg peak is a peak derived from the periodic structure of the molecular alignment. According to the composition for forming a polarizing layer of the present invention, a polarizing film having a period of 3.0 to 5.0 Å can be obtained.

The polymerizable liquid crystal compound is the same as the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal phase difference layer. The compound represented by the formula (2) (hereinafter sometimes referred to as "compound (2)")) is preferable. The compound (2) is preferred because it easily exhibits a liquid crystal state of the smectic phase.

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (2)

In the formula (2), X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. Wherein at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. The -CH ₂ - constituting the cyclohexane-1,4-diyl group which may have a substituent may be substituted with -O-, -S- or -NR-. R is an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Y ¹ and Y ² independently of each other represent -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, a single bond, -N=N-, -CR ^a =CR ^b -, -C≡ C- or -CR ^a =N-. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

W ¹ and W ² independently of each other represent a single bond, -O-, -S-, -COO- or -OCOO-.

V ¹ and V ² independently of each other represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group may be substituted with -O-, -S- or -NH-. ]

In the compound (2), as described above, at least two of X ¹ , X ² and X ³ are a 1,4-phenylene group which may have a substituent.

The 1,4-phenylene group which may have a substituent is preferably unsubstituted. The cyclohexane-1,4-diyl group which may have a substituent is preferably a trans-cyclohexane-1,4-diyl group which may have a substituent, and a trans-cyclohexane-1 which may have a substituent More preferably, the 4-diyl group is unsubstituted.

Examples of the 1,4-phenylene group which may have a substituent or the above-mentioned cyclohexane-1,4-diyl group may include alkane having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group. Base; cyano; halogen atom, etc.

Y ^{1 of the} compound (2) is preferably -CH ₂ CH ₂ -, -COO- or a single bond, and Y ^{2 is} preferably -CH ₂ CH ₂ - or -CH ₂ O-.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, and is preferably a polymerizable group. U ¹ and U ^{2 are} preferably all polymerizable groups, and more preferably all of them are photopolymerizable groups. The photopolymerizable group is a group which can participate in a polymerization reaction by an active radical or an acid produced by the following photopolymerization initiator. When a polymerizable liquid crystal compound having a photopolymerizable group is used, it is also advantageous in that the compound (2) can be polymerized under lower temperature conditions.

In the compound (2), the polymerizable groups of U ¹ and U ² may be different from each other, but are preferably the same kinds of groups. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloxy group, a methacryloxy group, and an oxypropyl group. Oxetanyl and the like. Among them, an acryloxy group, a methacryloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloxy group is more preferable.

Examples of the alkanediyl group having 1 to 20 carbon atoms in the alkanediyl group having 1 to 20 carbon atoms which may have a substituent represented by V ¹ and V ² include a methylene group, an ethylidene group, and a propane-1,3. -diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7 - Diyl, octane-1,8-diyl, decane-1,10-diyl, tetradecane-1,14-diyl and eicosane-1,20-diyl and the like. V ¹ and V ^{2 are} preferably an alkanediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms.

Examples of the substituent which the alkanediyl group having 1 to 20 carbon atoms which may have a substituent has may be a cyano group or a halogen atom, but the alkanediyl group is preferably unsubstituted, more preferably unsubstituted and Linear alkanediyl.

W ¹ and W ² are preferably each a single bond or -O- independently of each other.

The compound (2) includes a compound represented by the formula (2-1) to the formula (2-23), and the like. In the case where the specific example of the compound (2) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

The polymerizable liquid crystal compound contained in the composition for forming a polarizing layer may be used alone or in combination. In the case of combination, at least one of the compounds (2) is preferred.

The mixing ratio in the case of combining two kinds of polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50.

The polymerization system of the composition for forming a polarizing layer determines the phase transition temperature of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer in advance so as to be lower than the phase transition temperature. The method of polymerizing the polymerizable liquid crystal compound under temperature conditions is carried out by adjusting components other than the polymerizable liquid crystal compound. In the case where a mixture of two or more kinds of polymerizable liquid crystal compositions is used in the composition for forming a polarizing layer, the phase transition temperature of the mixture of the two or more kinds of polymerizable liquid crystal compounds is also determined.

Among the exemplified compounds (2), preferred are formula (2-2), formula (2-3), formula (2-4), formula (2-6), formula (2-7), and formula. (2-8), a compound represented by the formula (2-13), the formula (2-14), and the formula (2-15). When two or more kinds of these polymerizable liquid crystal compounds are mixed, the polymerization can be carried out under a temperature condition lower than the phase transition temperature, that is, a liquid crystal state in which the smectic phase of the smectic phase is sufficiently maintained. More specifically, the polymerizable liquid crystal compound can be polymerized by sufficiently maintaining the liquid crystal state of the higher order layer phase at a temperature of 70 ° C or lower, preferably 60 ° C or lower.

The content ratio of the polymerizable liquid crystal compound in the composition for forming a polarizing layer is preferably from 70 to 99.9% by mass, and more preferably from 90 to 99.9% by mass, based on the solid content of the composition for forming a polarizing layer. When the content ratio of the polymerizable liquid crystal compound is within the above range, the alignment property of the polymerizable liquid crystal compound tends to be high. Here, the solid content component refers to the total amount of components after removing the solvent from the composition for forming a polarizing layer.

The polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is produced, for example, by a known method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156.

The composition for forming a polarizing layer preferably contains a solvent.

The solvent is preferably a solvent which completely dissolves the polymerizable liquid crystal compound and the dichroic dye, and is preferably a solvent which is inert to the polymerization reaction of the polymerizable liquid crystal compound, and specific examples thereof include a phase difference from the liquid crystal. The composition for layer formation contains the same solvent.

The content of the solvent is preferably from 50 to 98% by mass based on the total amount of the composition for forming a polarizing layer. In other words, the solid content component in the composition for forming a polarizing layer is preferably from 2 to 50% by mass.

The composition for forming a polarizing layer preferably contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the composition for forming a polarizing layer and further flattening the coating film for forming a polarizing layer obtained by applying the composition for forming a polarizing layer, and examples thereof include a surfactant. . Preferred leveling agents include a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component.

As a leveling agent containing a polyacrylate compound as a main component, "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-" 358N", "BYK-361N", "BYK-380", "BYK-381" and "BYK-392" [BYK Chemie].

Examples of the leveling agent containing a fluorine atom-containing compound as a main component include "Megafac R-08", "Megafac R-30", "Megafac R-90", "Megafac F-410", and "Megafac F- 411", "Megafac F-443", "Megafac F-445", "Megafac F-470", "Megafac F-471", "Megafac F-477", "Megafac F-479", "Megafac F-482" And "Megafac F-483" [DIC (share)]; "Surflon S-381", "Surflon S-382", "Surflon S-383", "Surflon S-393", "Surflon SC-101", "Surflon SC-105", "KH-40" and "SA-100" [AGC Seimi Chemical (share)]; "E1830", "E5844" [Dakin Precision Chemical Research Institute (share)]; "Eftop EF301" , "Eftop EF303", "Eftop EF351" and "Eftop EF352" [Mitsubishi Materials Electronic Chemicals (share)].

In the case where the composition for forming a polarizing layer contains a leveling agent, the content thereof is usually 0.3 parts by mass or more and 5 parts by mass or less, preferably 0.5 parts by mass or more and 3 parts by mass or less based on 100 parts by mass of the polymerizable liquid crystal compound. the following. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound tends to be aligned horizontally, and the obtained polarizing film tends to be smoother. When the content of the leveling agent relative to the polymerizable liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing layer. Further, the polarizing layer-forming composition may contain two or more kinds of leveling agents.

The composition for forming a polarizing layer preferably contains a polymerization initiator. The polymerization initiator is a compound which can start the polymerization reaction of the polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator is preferred in terms of starting the polymerization reaction under low temperature conditions. Specifically, a compound which generates an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those which generate active radicals by the action of light are more preferred.

The polymerization initiator is the same as the polymerization initiator contained in the composition for forming a liquid crystal phase difference layer.

In the case where the composition for forming a polarizing layer contains a polymerization initiator, the content thereof can be appropriately adjusted depending on the kind and amount of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer, relative to the polymerizable liquid crystal compound. The total amount of the polymerization initiator is usually 0.1 to 30 parts by mass, preferably 0.5 to 15 parts by mass, more preferably 0.5 to 8 parts by mass, based on 100 parts by mass. When the content of the polymerizable initiator is within this range, it can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound, which is preferable.

When the composition for forming a polarizing layer contains a photopolymerization initiator, the composition for forming a polarizing layer may further contain a photosensitizer. As the photosensitizer, for example, Ketone and 9-oxosulfur Wait Ketone compounds (for example, 2,4-diethyl 9-oxosulfur 2-isopropyl 9-oxosulfur And other compounds such as anthracene and alkoxy-containing anthracene (eg, dibutoxyanthracene, etc.); And red fluorene and the like.

When the composition for forming a polarizing layer is a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is further promoted. The content of the photosensitizer can be appropriately adjusted according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal compound to be used, and is usually 0.1 to 30 parts by mass, preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the total of the polymerizable liquid crystal compound. It is 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass.

In order to stably carry out the polymerization reaction of the polymerizable liquid crystal compound, the polarizing layer is formed. The composition may also comprise a polymerization inhibitor. The degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

Examples of the polymerization inhibitor include hydroquinone, alkoxy-containing hydroquinone, alkoxy-containing catechol (for example, butyl catechol), pyrogallol, and the like. A radical scavenger such as 2,2,6,6-tetramethyl-1-piperidinyloxy radical; thiophenols; β-naphthylamines and β-naphthols.

In the case where the composition for forming a polarizing layer contains a polymerization inhibitor, the content thereof can be appropriately adjusted depending on the kind and amount of the polymerizable liquid crystal compound to be used in combination, the amount of the photosensitizer used, and the like, with respect to the mass of the polymerizable liquid crystal compound 100. The portion is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass. When the content of the polymerization inhibitor is within the above range, it can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer, which is preferable.

The content of the dichroic dye in the composition for forming a polarizing layer can be appropriately adjusted according to the type of the dichroic dye, and is usually 0.1 parts by mass or more and 50 parts by mass based on 100 parts by mass of the total of the polymerizable liquid crystal compound. Hereinafter, it is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 15 parts by mass or less. When the content of the dichroic dye is within this range, the polymerizable liquid crystal compound can be polymerized without disturbing the alignment of the polymerizable liquid crystal compound, which is preferable.

Next, a method of forming a polarizing layer on the retardation film, preferably on the alignment layer, using the composition for forming a polarizing layer will be described.

First, a composition for forming a polarizing layer is applied onto a retardation film to form a coating film for forming a polarizing layer. In this case, it is preferred to provide an alignment layer on the surface of the retardation film on which the polarizing layer is to be formed. The method for forming the alignment layer is the same as the method for forming the alignment layer described in the description of formation of the liquid crystal phase difference layer. The alignment layer provided between the polarizing layer and the retardation film is the same as the alignment layer provided between the liquid crystal phase difference layer and the retardation film, and is preferably an optical alignment layer. Aligned between the polarizing layer and the retardation film The thickness is determined so that the total thickness of the circular polarizing plate does not significantly exceed the following range, and is usually 10 to 1000 nm. In the present invention, it is necessary to perform polarized light irradiation so as not to be horizontal or non-perpendicular to the retardation axis of the retardation film, preferably 15° or -15 with respect to the retardation axis of the retardation film. Irradiation in the direction of °.

The method of applying the composition for forming a polarizing layer to the alignment layer is the same as the method exemplified as the coating method of the composition for forming an alignment layer.

Then, the solvent is dried and removed under the condition that the polymerizable liquid crystal compound contained in the coating film for forming a polarizing layer is not polymerized, thereby forming a dried film. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. Then, it is preferred that the nematic phase is transferred to a smectic phase after the liquid crystal state of the polymerizable liquid crystal composition contained in the dried film is a nematic phase. In order to form the smectic phase through the nematic phase, for example, the method is as follows: heating to a temperature at which the polymerizable liquid crystal compound phase contained in the dried film is transferred to a liquid crystal state of the nematic phase, and then cooling to the polymerizable layer type The liquid crystal compound shows the temperature of the liquid crystal state of the layer phase.

When the polymerizable liquid crystal compound in the dried film is in a smectic liquid crystal state or is formed into a smectic liquid crystal state via a nematic liquid crystal state, the phase transition temperature of the polymerizable liquid crystal compound can be easily measured. The conditions (heating conditions) for controlling the liquid crystal state are obtained.

Next, the polymerization step of the polymerizable liquid crystal compound will be described. Here, the method of forming the polarizing layer forming composition contains a photopolymerization initiator, and the liquid crystal state of the polymerizable liquid crystal compound in the dried film is a smectic phase, and the liquid crystal state of the smectic phase is maintained. The polymerizable liquid crystal compound is photopolymerized. In the photopolymerization, the light to be irradiated to the dry film may be based on the type of the photopolymerization initiator contained in the dried film or the type of the polymerizable liquid crystal compound (especially the polymerizable group of the polymerizable liquid crystal compound). The species and the amount thereof are suitably carried out using light or an active electron beam selected from the group consisting of visible light, ultraviolet light, and laser light. Among these, it is easy to control Ultraviolet light is preferred in terms of the progress of the polymerization reaction or the use of a wide range of users in the field as a device for photopolymerization. Therefore, it is preferred to select the type of the polymerizable liquid crystal compound or the photopolymerization initiator contained in the composition for forming a polarizing layer by photopolymerization using ultraviolet light. Further, at the time of polymerization, the drying film may be cooled by irradiation with ultraviolet light by an appropriate cooling means, whereby the polymerization temperature is controlled. When the polymerization of the polymerizable liquid crystal compound can be carried out at a lower temperature by using such a cooling means, there is an advantage that the polarizing layer can be appropriately formed even if the retardation film is used in a relatively low heat resistance. Further, in the case of photopolymerization, a patterned polarizing layer can also be obtained by masking or developing.

By carrying out the photopolymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining the smectic phase, preferably in a liquid crystal state as exemplified as the higher order smectic phase, to form a polarizing layer. The polarizing layer obtained by polymerizing the liquid crystal compound to maintain the liquid crystal state of the smectic phase has the following advantages: with the action of the above dichroic dye, the polarizing performance is much higher than that of the previous host-guest type polarizing layer, that is, A polarizing layer obtained by polymerizing a polymerizable liquid crystal compound or the like while maintaining a liquid crystal state of a nematic phase. Further, there is an advantage that the strength is excellent as compared with the case of applying only a dichroic dye or to a liquid crystal.

The thickness of the polarizing layer thus formed is determined so that the total thickness of the circularly polarizing plate does not significantly exceed the following range. For example, it is preferably in the range of 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less.

As described above, the present polarizing plate can be produced by the above-described manufacturing method. However, in the present manufacturing method described herein, the order of the liquid crystal phase difference layer forming step and the polarizing layer forming step may be reversed. The present manufacturing method described above is formed by sequentially performing a preparation step, a liquid crystal phase difference layer forming step, and a polarizing layer forming step, but the preparation step, the polarizing layer forming step, and the liquid crystal phase difference layer formation are sequentially performed. The step can also obtain the circular polarizing plate. The conditions and the like of each step in this case are as described.

Hereinabove, the outline of the manufacturing method of the circularly polarizing plate in the present invention has been described in the commercial When the present polarizing plate is manufactured, a method of continuously producing the polarizing plate can be achieved. As a preferable example of such a continuous production method, a method of using a roll-to-roll type (hereinafter, referred to as "the present manufacturing method of continuity") may be mentioned.

As one embodiment of the manufacturing method of continuity, for example, (i) a step of preparing a roll of a retardation film on a winding core; (ii) a step of continuously feeding the retardation film from the roll; (iii) applying a composition for forming an alignment layer on the retardation film, and continuously forming a first alignment layer on the retardation film; (iv) coating the first alignment layer formed in (iii) a liquid crystal phase difference layer forming composition, a step of continuously forming a liquid crystal phase difference layer on the first alignment layer; (v) coating a surface of the retardation film opposite to a surface on which the liquid crystal phase difference layer is formed, a composition for forming a wiring alignment layer, a step of continuously forming a second alignment layer on the retardation film; (vi) applying a composition for forming a polarizing layer on the second alignment layer formed in (v), a step of continuously forming a polarizing layer on the second alignment layer to obtain the circular polarizing plate; (vii) a step of winding the continuously obtained circular polarizing plate on the second core to obtain the second volume.

Hereinafter, the manufacturing method of the continuity will be described with reference to Fig. 2, but in the figure, the details of the formation of the alignment layers corresponding to (iii) and (v) are omitted.

First, a roll 210 having a retardation film is prepared in (i).

(ii) the retardation film 110 is continuously wound out from the first roll 210, and the first alignment layer (not shown) is formed on one surface of the retardation film in (iii), and the alignment layer is formed on one side. The first layered body 120.

Then, in (iv), a liquid crystal phase difference layer is formed on the first alignment layer formed by (iii). Specifically, the composition for forming a liquid crystal phase difference layer is applied using a coating device 211A, and a coating film for forming a liquid crystal phase difference layer is formed on the alignment layer. Formation of the above coating The film is passed through a drying device 212A together with the retardation film to remove a solvent or the like. Further, light irradiation is performed by the light irradiation device 213A, and the second layered body 140 provided with the retardation layer and the liquid crystal phase difference layer is obtained.

Then, in (v), a second alignment layer (not shown) is formed on the surface of the second layered body 140 opposite to the surface on which the liquid crystal phase difference layer is provided, and the third layer on which the second alignment layer is formed is obtained. The laminate 150.

On the second alignment layer of the third layered body 150 obtained in (v), a polarizing layer is formed in (vi). Specifically, the composition for forming a polarizing layer is applied using a coating device 211B, and a coating film for forming a polarizing layer is formed on the second alignment layer. The formed coating film is passed through a drying device 212B together with the retardation film to remove a solvent or the like. Further, light irradiation is performed by the light irradiation device 213B, and the circular polarizing plate 100 in which the liquid crystal phase difference layer, the retardation layer, and the polarizing layer are sequentially provided is obtained.

The obtained circular polarizing plate 100 is wound up on the second core to obtain a second roll 220.

The total thickness of the circular polarizing plate is suitable for a display device which is required to be thin. The total thickness is usually 20 to 200 μm, preferably 20 to 100 μm.

The circular polarizing plate 100 thus obtained is further used in the form of a member of a display device cut to a desired size according to the use of the present circular polarizing plate.

Preferably, the circular polarizing plate controls the angle formed by the liquid crystal phase difference layer, the retardation layer, and the retardation axis of the polarizing layer.

Referring to Fig. 1, a preferred aspect of the present circular polarizing plate 100 is shown. In the present polarizing plate 100, it is preferable that the retardation layer 1 functions as a half-wavelength plate, and the liquid crystal phase difference layer functions as a quarter-wavelength plate. Further, the retardation axis of the liquid crystal phase difference layer 2 (1/4 wavelength plate) is smaller than the angle formed by the retardation axis of the phase difference layer 1 (1/2 wavelength plate) (AG2), and the polarizing layer The smaller angle (AG3) of the angle formed by the absorption axis or the transmission axis of 3 with respect to the retardation axis of the phase difference layer 1 (1/2 wavelength plate) is preferably the following combination.

. The combination of AG2 is substantially 60° and AG3 is substantially -15°.

. The combination of AG2 is substantially 90° and AG3 is substantially -22.5°

The circular polarizing plate can be used for a wide variety of display devices. A display device is a device having a display element, and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, and an electron emission display device (for example, a field emission display device (FED), and a surface field emission display. Device (SED), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (such as grating light valve (GLV) display device, digital micromirror device (DMD)) A display device), a piezoelectric ceramic display, etc. The liquid crystal display device includes any one of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, an intuitive liquid crystal display device, and a projection type liquid crystal display device. The display device may be a display device for displaying a two-dimensional image, or a stereoscopic display device for displaying a three-dimensional image. In particular, it can be effectively used for an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL). A display device for a display device.

As an example of a display device including the present circular polarizing plate, an EL display device (hereinafter sometimes referred to as "the present EL display device") will be described with reference to FIG. In the EL display device 30, an organic functional layer 36 and a cathode electrode 37, which are light-emitting sources, are stacked on a substrate 33 on which the pixel electrodes 35 are formed. The circular polarizing plate 100 is placed on the substrate 33 and disposed opposite to the organic functional layer 36. A positive voltage is applied to the pixel electrode 35, a negative voltage is applied to the cathode electrode 37, and a direct current is applied between the pixel electrode 35 and the cathode electrode 37, whereby the organic functional layer 36 emits light. The light source, that is, the organic functional layer 36, includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, and the present circular polarizing plate 100. The organic EL display device having the organic functional layer 36 will be described, and it can also be applied to an inorganic EL display device having an inorganic functional layer.

When the present EL display device 30 is manufactured, first, the thin film transistor 40 is formed on the substrate 33 in a desired shape. Then, the interlayer insulating film 34 is formed into a film, and then the pixel electrode 35 is formed into a film by sputtering to be patterned. Thereafter, the organic functional layer 36 is laminated.

Then, the circular polarizing plate 100 is provided on the opposite surface of the surface of the substrate 33 on which the thin film transistor 40 is provided. In this case, the phase difference layer 2 of the circular polarizing plate 100 is disposed on the side of the substrate 33.

Next, members other than the circular polarizing plate 100 of the EL display device 30 will be briefly described.

Examples of the substrate 33 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate, and a ceramic substrate such as alumina; a metal substrate such as copper; and a plastic substrate. Although not shown, a thermally conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (such as DLC (Diamond-like carbon)). When the pixel electrode 35 is of a reflective type, light is emitted in the opposite direction of the substrate 33. Therefore, not only a transparent material but also a non-transmissive material such as stainless steel can be used. The substrate may be formed singly or in the form of a laminated substrate by bonding a plurality of substrates with an adhesive. Moreover, these substrates are not limited to a plate shape, and may be a film.

As the thin film transistor 40, for example, a polycrystalline germanium transistor or the like may be used. The thin film transistor 40 is provided at the end of the pixel electrode 35 and has a size of about 10 to 30 μm. Further, the size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

A wiring electrode of the thin film transistor 40 is provided on the substrate 33. The wiring electrode has a low resistance and has a function of electrically connecting to the pixel electrode 35 and suppressing a low resistance value. Generally, the wiring electrode is made of Al, Al, and a transition metal (excluding Ti), Ti or titanium nitride (TiN). One or more of them.

An interlayer insulating film 34 is provided between the thin film transistor 40 and the pixel electrode 35. The interlayer insulating film 34 is formed by sputtering or vacuum deposition to form an inorganic material such as cerium oxide or tantalum nitride such as SiO ₂ or a cerium oxide layer formed of SOG (spin-coated glass), a photoresist, or a poly Any one of the coating film of a resin material such as a quinone imine or an acrylic resin may have insulation properties.

A barrier wall 41 is formed on the interlayer insulating film 34. The barrier wall 41 is disposed on the pixel electrode 35 The peripheral part (between adjacent pixels). Examples of the material of the barrier rib 41 include an acrylic resin and a polyimide resin. The thickness of the barrier rib 41 is preferably 1.0 μm or more and 3.5 μm, and more preferably 1.5 μm or more and 2.5 μm or less.

Next, an EL element including a pixel electrode 35 which is a transparent electrode, an organic functional layer 36 which is a light source, and a cathode electrode 37 will be described. The organic functional layer 36 has at least one layer of a hole transport layer and a light-emitting layer, and has, for example, an electron injection transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer in this order.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO (Indium Gallium Zinc Oxide), ZnO, SnO _{2 ,} and In ₂ O ₃ . Good for ITO or IZO. The thickness of the pixel electrode 35 may have a thickness sufficient for hole injection, and is preferably about 10 to 500 nm.

The pixel electrode 35 can be formed by an evaporation method (preferably, a sputtering method). The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr or Xe or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 37, for example, a metal element such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, or Zr may be used, but the electrode is improved. For the activation stability, it is preferred to use an alloy system selected from two or three of the metal elements exemplified. As the alloy system, for example, Ag is preferred. Mg (Ag: 1~20at%), Al. Li (Li: 0.3~14at%), In. Mg (Mg: 50~80at%) and Al. Ca (Ca: 5 to 20 at%) and the like.

The cathode electrode 37 is formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35. The hole transport layer has a function of transmitting holes and a function of blocking electrons, and is also called a charge injection layer or a charge transport layer.

Thickness of the light-emitting layer, thickness of the hole injection layer and the hole transport layer, and electrons The thickness of the injection transport layer is not particularly limited, and is preferably about 5 to 100 nm depending on the formation method. Various organic compounds can be used in the hole injection layer or the hole transport layer. When a hole is injected into the transport layer, the light-emitting layer, and the electron injecting and transporting layer, a vacuum thin film method can be used in terms of forming a homogeneous film.

As the organic functional layer 36 which is a light-emitting source, those who emit light (fluorescence) from singlet excitons, those that emit light from triplet excitons (phosphorescence), and those that use light from singlet excitons can be used. a layer of light), a layer formed by light emission (phosphorescence) from a triplet exciton, a person formed of an organic substance, a layer formed of an organic substance, a layer formed of an inorganic substance, a material of a polymer, a material of a low molecule, and a material Polymer materials and low molecular materials. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials can be used for the EL display device 30 as an EL element.

A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing cover 39. The reason for this is that the organic functional layer 36 cannot withstand moisture. The desiccant 38 absorbs moisture to prevent deterioration of the organic functional layer 36.

4 is a schematic view showing a cross-sectional configuration of another aspect of the EL display device 30. The EL display device 30 has a sealing structure using a film sealing film 42, and light can be obtained from the opposite surface of the array substrate.

As the film sealing film 42, a DLC film in which DLC (Diamond-Like Carbon) is vapor-deposited on a film using an electrolytic capacitor is preferable. The DLC film has a characteristic of poor moisture permeability and high moisture resistance. Further, a DLC film or the like may be formed by directly vapor-depositing the surface of the cathode electrode 37. Further, the resin film and the metal film may be laminated in a plurality of layers to form the film sealing film 41.

In the present EL display device including the circular polarizing plate 100, since the circular polarizing plate 100 has extremely excellent antireflection performance, it has no black display color when viewed from a bright place, and is excellent as a display device.

[Examples]

Hereinafter, the present invention will be described in further detail by way of examples. "%" in the example and "Parts" are % by mass and parts by mass unless otherwise specified.

Example 1 [Preparation of Composition (1) for Liquid Crystal Phase Difference Layer Formation]

The following components were mixed and stirred at 80 ° C for 1 hour to obtain a liquid crystal retardation layer-forming composition (1).

Polymeric liquid crystal compound: trade name LC-242 100 parts manufactured by BASF

Polymerization initiator: 2-methyl-1-[4-(methylthio)phenyl]-2- Tropicpropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals Co., Ltd.) 3 parts

Solvent: cyclopentanone 250 parts

[Preparation of Composition (1) for Photoalignment Layer Formation]

The following components were mixed and stirred at 80 ° C for 1 hour to obtain a composition (1) for photoalignment layer formation.

Light-induced alignment material: 5 parts

Solvent: cyclopentanone 95 parts

[Preparation of Composition (1) for Polarizing Layer Formation]

The following components were mixed and stirred at 80 ° C for 1 hour to obtain a composition for forming a polarizing layer containing a dichroic dye.

Polymerizable liquid crystal compound: Compound (2-6) 75 parts

Compound (2-7) 25 parts

Dichroic pigment: dichroic pigment (1-1-1) 2.5 parts

Dichroic pigment (1-1-2) 2.5 parts

Dichroic pigment (1-3-1) 2.5 parts

Polymerization initiator: 2-dimethylamino-2-benzyl-1-(4- Polinylphenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals Co., Ltd.) 6 parts

Leveling agent: polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) 1.5 parts

Solvent: cyclopentanone 250 parts

[Measurement of phase transition temperature]

The composition for forming a polarizing layer (1) was applied onto a glass and dried to prepare a sample, and the phase transition temperature was confirmed by texture observation using a polarizing microscope. The dried film obtained by the composition for forming a polarizing layer (1) was cooled to 140 ° C and then cooled, and then phase-transformed into a nematic phase at 108 ° C, and phase-transformed into a layer A phase at 101 ° C at 76 ° C. The lower phase is transferred into a layer B phase.

[Manufacture of this circular polarizer] 1. Formation of the second alignment layer

As the retardation film, a 1/2 wavelength plate (Zeonor Film, Japan Zeon Co., Ltd., in-plane retardation value: 270 nm) which is a uniaxially stretched film of a cyclic olefin resin is used.

The composition for light-aligning layer formation (1) was applied to the retardation film by a bar coating method, and dried by heating in a drying oven at 60 ° C for 1 minute. The obtained light alignment evoked layer is irradiated with polarized light UV to form a photoalignment layer. The polarized UV system was irradiated with a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ. Further, the polarization direction of the polarized UV is performed so as to be 15° with respect to the retardation axis of the retardation layer including the retardation film.

2. Formation of polarizing layer

The polarizing layer-forming composition (1) was applied onto the second alignment layer by a bar coating method, and dried by heating in a drying oven at 120 ° C for 1 minute, and then cooled to room temperature to obtain a dried film. Using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), the obtained dried film was irradiated with ultraviolet light having an exposure amount of 1200 mJ/cm ² (365 nm basis) to form a polarizing layer, and a phase difference of the polarizing layer was obtained. Membrane (1). The thickness of the polarizing layer at this time was measured by a laser microscope (OLS3000, manufactured by Olympus Co., Ltd.), and found to be 1.9 μm.

3. Formation of the first alignment layer

The photo-alignment layer-forming composition (1) was applied to the surface of the retardation film (1) with the polarizing layer obtained on the opposite side of the polarizing layer by a bar coating method, and dried by heating in a drying oven at 60 ° C. minute. Thereafter, the obtained light alignment evoked layer is subjected to a polarized UV irradiation treatment to form a photoalignment layer. The polarized UV is irradiated under the same conditions as the second alignment layer described above. The polarization direction of the polarized UV is 60° with respect to the retardation axis of the retardation layer including the retardation film (in this case, the absorption axis of the polarizing film is -15°).

4. Formation of phase difference layer

The liquid crystal phase difference layer-forming composition (1) was applied onto the first alignment layer by a bar coating method, and dried by heating in a drying oven at 50 ° C for 1 minute, and then cooled to room temperature to obtain a dried film. The obtained dried film was irradiated with ultraviolet rays having an exposure amount of 500 mJ/cm ² (365 nm basis) to form a liquid crystal phase difference layer, and a circular polarizing plate was obtained by using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.). (1). The thickness of the retardation layer at this time was measured by a laser microscope (OLS3000, manufactured by Olympus Co., Ltd.), and it was 1.0 μm. The total thickness of the circular polarizing plate (1) was measured by a contact type film thickness meter and found to be 46 μm.

[Evaluation of this circular polarizing plate (1)] 1. X-ray diffraction measurement

The polarizing layer of the circular polarizing plate (1) was subjected to X-ray diffraction measurement using an X-ray diffraction apparatus X'Pert PRO MPD (manufactured by Spectris Co., Ltd.). Using Cu as a target, the X-ray generated under the conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV is self-friction direction via a fixed divergence slit 1/2° (predetermining the friction of the alignment layer under the polarizing layer in advance) Direction) Incident, stepping in the range of 2θ=4.0~40.0° in the range of 2θ=0.01671° Scanning and measurement were carried out, and as a result, a steep diffraction peak (Prague peak) of a full width at half maximum (FWHM) = about 0.29 ° was obtained in the vicinity of 2θ = 20.12 °. Also, the same result can be obtained from the incidence of the alignment in the vertical direction. The order period (d) obtained from the peak position is about 4.4 Å, and it is understood that a structure reflecting the high-order layer phase is formed.

2. Determination of reflectivity

In order to confirm the usefulness of the circular polarizing plate (1), the reflectance was measured in the following manner. The liquid crystal phase difference layer side of the produced circular polarizing plate (1) and the reflecting plate (mirror aluminum plate) were bonded together using an adhesive to prepare a measurement sample.

Using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation), the reflectance of the reflected light was measured by measuring the light in the range of 400 to 700 nm from the normal direction of the sample at a range of from 120 to 700 nm in a step of 2 nm. When the reflectance of the circular polarizing plate (1) was not bonded and only the reflecting plate was placed, the reflectance was set to 100% and compared, and as a result, the reflectance of any wavelength in the range of 400 to 700 nm was 1 to 10%. Full anti-reflection properties are obtained across the left and right across the visible light.

Example 2

In the same manner as in the first embodiment, a photoalignment layer is formed on one surface of the retardation film (the polarization direction of the polarized UV is 60° with respect to the retardation axis of the retardation film), and a liquid crystal phase difference layer is formed on the photoalignment layer. . Thereafter, a photoalignment layer is formed on a surface of the retardation film with a liquid crystal phase difference opposite to the liquid crystal phase difference (the polarization direction of the polarized UV is 15° with respect to the retardation axis of the retardation film), and the photoalignment layer is formed on the photoalignment layer. Further, a polarizing layer is formed to form a circular polarizing plate (2).

The total thickness of the circular polarizing plate (2) was measured by a contact type film thickness meter and found to be 46 μm.

In the same manner as in the first embodiment, the circular polarizing plate (2) was bonded to the reflecting plate using an adhesive to measure the reflectance, and as a result, the reflectance at any wavelength of the light in the range of 400 to 700 nm was about 1 to 10%. Full anti-reflective properties are obtained across the entire spectrum of visible light.

Comparative example 1

In the same manner as in the first embodiment, a 1/4 wavelength plate (Zeonor Film, Japan Zeon Co., Ltd., in-plane retardation value: 138 nm) which is a uniaxially stretched film of a cyclic olefin resin is used as the retardation film. Forming a photoalignment layer on one side of the retardation film (the polarization direction of the polarized UV is 45° with respect to the retardation axis of the retardation film), and forming a polarizing layer on the photoalignment layer to form a circular polarizing plate (3) .

In the same manner as in Example 1, the circular polarizing plate (3) was bonded to the reflecting plate using an adhesive to measure the reflectance. As a result, the light of 500 to 600 nm was excellent in reflectance of about 1 to 10%. However, the light reflectance of 400 to 500 nm and 600 to 700 nm is 10% or more, and the reflected light is blue-violet, and sufficient anti-reflection function cannot be obtained.

Reference example 1

A iodine-PVA (polyvinyl alcohol) polarizing plate (a thickness of 105 μm manufactured by Sumikalan Sumitomo Chemical Co., Ltd.) as a polarizing plate was cut into pieces of 100 × 100 mm so that the absorption axis became 0°. The 1/2 wavelength plate used was cut into pieces of 100 × 100 mm in such a manner that the slow phase axis became 15°, and the quarter wave plate used in Comparative Example 1 was cut into 100 × 100 mm in such a manner that the slow phase axis became 75°. In the small piece, each film was bonded one by one with an acrylic adhesive (film thickness: 25 μm) so as to be a polarizing plate + a half-wave plate + a quarter-wave plate, and a circular polarizing plate (4) was produced.

In the same manner as in Example 1, the circular polarizing plate (4) was bonded to the reflecting plate using an adhesive to measure the reflectance, and as a result, the reflectance at any wavelength of the light in the range of 400 to 700 nm was about 1 to 10%. Full anti-reflective properties are obtained across the entire visible light range. However, the total thickness was measured by a contact type film thickness meter, and as a result, it was 240 μm, which was about 5 times the thickness of the circular polarizing plate (1).

[Industrial availability]

The circularly polarizing plate (this circular polarizing plate) of the present invention is useful for an organic EL display device or the like.

1‧‧‧ phase difference layer

2‧‧‧Liquid phase difference layer

2A‧‧‧Alignment layer

3‧‧‧ polarizing layer

3A‧‧‧Alignment layer

100‧‧‧this circular polarizer

Claims (12)

A circularly polarizing plate is provided with a liquid crystal phase difference layer formed of a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound, and a phase difference layer including a phase formed by extending a polymer film. a poor film; and a polarizing layer formed of a composition for forming a polarizing layer containing a dichroic dye. The circularly polarizing plate of claim 1, wherein the composition for forming a polarizing layer further comprises a polymerizable liquid crystal compound. The circularly polarizing plate of claim 2, wherein the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is a compound exhibiting a liquid crystal state of a column phase. The circularly polarizing plate according to any one of claims 1 to 3, wherein the phase difference layer is a 1/2 wavelength plate, and the liquid crystal phase difference layer is a 1/4 wavelength plate. The circularly polarizing plate according to any one of claims 1 to 4, wherein the polarizing layer is obtained by obtaining a Bragg peak in an X-ray diffraction measurement. The circularly polarizing plate according to any one of claims 1 to 5, wherein a first alignment layer is provided between the liquid crystal phase difference layer and the retardation layer, and between the retardation layer and the polarizing layer is provided The second alignment layer. The circularly polarizing plate of claim 6, wherein the liquid crystal phase difference layer is formed by applying a composition for forming a liquid crystal phase difference layer containing a polymerizable liquid crystal compound onto the first alignment layer. The circularly polarizing plate of claim 6 or 7, wherein the polarizing layer is formed by applying a composition for forming a polarizing layer containing a dichroic dye to the second alignment layer. The circularly polarizing plate according to any one of claims 6 to 8, wherein the first alignment layer and/or the second alignment layer are a combination of alignment layer formation comprising a light-induced alignment material. The person formed by the object. A method for producing a circularly polarizing plate, comprising: a preparation step, a liquid crystal phase difference layer forming step, and a polarizing layer forming step, and a preparation step of: preparing a retardation film formed by extending a polymer film; forming a liquid crystal phase difference layer a step of applying a liquid crystal phase difference layer-forming composition containing a polymerizable liquid crystal compound to one surface of the retardation film, and forming a liquid crystal phase difference layer from the applied coating film for forming a liquid crystal phase difference layer; The forming step is a step of applying a composition for forming a polarizing layer containing a dichroic dye to the other surface of the retardation film, and forming a polarizing layer from the applied coating film for forming a polarizing layer. A display device comprising the circular polarizing plate and the display element according to any one of claims 1 to 9. A display device according to claim 11, comprising a liquid crystal cell, an organic EL element, or a touch panel as a display element.