JP2013228706A - Circularly polarizing plate and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin circularly polarizing plate having superior antireflection capability, a method of manufacturing the same, and a display device equipped with the same.SOLUTION: Provided are a circularly polarizing plate having a liquid crystal phase difference layer formed with a liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound, a phase difference layer comprising a phase difference film formed by stretching a polymer film, and a polarizing layer formed with a polarizing layer forming composition containing a dichroic segment, arranged in the described order, and a method of (continuously) manufacturing the same. Also provided is a display device equipped with the circularly polarizing plate and display elements such as organic EL display elements.

Description

  The present invention relates to a circularly polarizing plate and a manufacturing method thereof.

  A broadband circularly polarizing plate (circularly polarizing plate) used in a liquid crystal display device is usually a polarizing film made of polyvinyl alcohol dyed with iodine, a half-wave plate and a quarter-wave plate, for example, a half-wave plate. In addition, the angle between the slow axis of the quarter-wave plate and the absorption axis of the polarizing film is 15 ° and 75 °, respectively. ing. However, such a circularly polarizing plate is unavoidably increased in total thickness, and is not suitable for a circularly polarizing plate used in a current display device that is required to be thinner. Therefore, an attempt has been made to produce a thin circular polarizing plate by avoiding lamination by bonding and forming either a polarizing film, a half-wave plate or a quarter-wave plate by a coating method. .

  For example, Patent Document 1 describes a circularly polarizing plate in which a polarizer formed using a thermotropic liquid crystalline or lyotropic liquid crystalline substance and a retardation layer (positive wavelength dispersive film) are laminated. .

JP 2009-251288 A

  However, according to the study of the present inventor, the circularly polarizing plate described in Patent Document 1 has been found to have insufficient antireflection performance as a circularly polarizing plate.

The present invention includes the following inventions.
[1] A liquid crystal retardation layer formed from a composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound,
A retardation layer comprising a retardation film formed by stretching a polymer film;
The circularly-polarizing plate provided with the polarizing layer formed from the composition for polarizing layer formation containing a dichroic dye in this order.
[2] The circularly polarizing plate according to [1], wherein the composition for forming a polarizing layer further contains 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 smectic phase liquid crystal state.
[4] The circularly polarizing plate according to any one of [1] to [3], wherein the retardation layer is a half-wave plate and the liquid crystal retardation layer is a quarter-wave plate.
[5] The circularly polarizing plate according to any one of [1] to [4], wherein the polarizing layer has a Bragg peak in X-ray diffraction measurement.
[6] A first alignment layer is provided between the liquid crystal retardation layer and the retardation layer,
The circularly polarizing plate according to any one of [1] to [5], wherein a second alignment layer is provided between the retardation layer and the polarizing layer.
[7] The circularly polarizing plate according to [6], wherein the liquid crystal retardation layer is formed by applying a composition for forming a liquid crystal retardation 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 polarizing layer forming composition containing a dichroic dye to the second alignment layer.
[9] Any one of [6] to [8], wherein the first alignment layer and / or the second alignment layer is formed from a composition for forming an alignment layer containing a photo-induced alignment material. The circularly polarizing plate as described.
[10] A method for producing a circularly polarizing plate comprising the following preparation step, liquid crystal retardation layer forming step and polarizing layer forming step.
Preparation step: a step of preparing a retardation film formed by stretching a polymer film;
Liquid crystal phase difference layer forming step: A liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound is applied to one surface of the phase difference film, and the liquid crystal phase difference layer forming coating film is applied to the liquid crystal phase difference layer. Forming a layer;
Polarizing layer forming step: a step of applying a polarizing layer forming composition containing a dichroic dye to the other surface of the retardation film, and forming a polarizing layer from the applied polarizing layer forming coating film.
[11] A display device comprising the circularly polarizing plate according to any one of [1] to [9] and a display element.
[12] The display device according to [11], comprising a liquid crystal cell, an organic EL element or a touch panel as a display element.

  ADVANTAGE OF THE INVENTION According to this invention, the thin-shaped circularly-polarizing plate excellent in the antireflection performance, the manufacturing method of the said circularly-polarizing plate, and the display apparatus provided with the said circularly-polarizing plate can be provided.

It is a schematic diagram showing the cross-sectional structure of the circularly-polarizing plate of this invention. It is a schematic diagram showing an example of the continuous manufacturing method of the circularly-polarizing plate of this invention. It is a schematic diagram showing the cross-sectional structure of the EL display apparatus using the circularly-polarizing plate of this invention. It is a schematic diagram showing the cross-sectional structure of the EL display apparatus using the circularly-polarizing plate of this invention.

<Circularly polarizing plate>
The circularly polarizing plate of the present invention (hereinafter sometimes referred to as “the present circularly polarizing plate”)
A liquid crystal retardation layer formed from a composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound; and
A retardation layer comprising a retardation film formed by stretching a polymer film;
A polarizing layer formed from a composition for forming a polarizing layer containing a dichroic dye is provided in this order. In the configuration of the present circularly polarizing plate, it is preferable that the retardation phase is a half-wave plate and the liquid crystal retardation layer is a quarter-wave plate. First, the manufacturing method of this circularly-polarizing plate is demonstrated.

FIG. 1 is a schematic diagram showing the configuration of the present circularly polarizing plate. 1A1 relates to the present circularly polarizing plate 100 in which the liquid crystal retardation layer 2, the retardation layer 1, and the polarizing layer 3 are provided in this order.
The configuration of FIG. 1A2 is a preferable configuration of this circularly polarizing plate, in which an alignment layer 2A is provided between the liquid crystal retardation layer 2 and the retardation layer 1, and between the polarizing layer 3 and the retardation layer 1. Each of the alignment layers 3A is related to the present circularly polarizing plate 100 further provided.

<The manufacturing method of this circularly-polarizing plate (Hereinafter, it is called "the manufacturing method.")>
The manufacturing method of this circularly-polarizing plate usually has the following preparatory steps, a liquid crystal retardation layer forming step, and a polarizing layer forming step.
Preparation step: a step of preparing a retardation film formed by stretching a polymer film;
Liquid crystal phase difference layer forming step: A liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound is applied to one surface of the phase difference film, and the liquid crystal phase difference layer forming coating film is applied to the liquid crystal phase difference layer. Forming a layer;
Polarizing layer forming step: A step of applying a polarizing layer forming composition containing a dichroic dye to the other surface of the retardation film, and forming a polarizing layer from the applied polarizing layer forming coating film.

Preparation process:
The retardation film prepared in the preparation process of this manufacturing method is formed by stretching a polymer film. The polymer film is preferably a transparent film capable of transmitting light, particularly visible light. Transparency refers to the property that the transmittance with respect to light rays over a wavelength range of 380 to 780 nm is 80% or more. Examples of the polymer constituting the polymer film include polyolefins such as polyethylene, polypropylene and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylates; polyacrylates; Cellulose esters such as diacetylcellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of easy availability and higher transparency, a polymer film composed of cellulose ester, cyclic olefin resin, and polycarbonate is preferable.

Among these, a polymer film composed of a cyclic olefin resin (hereinafter sometimes referred to as a cyclic olefin resin film) is particularly preferable because it can easily control the retardation.

  Cyclic olefin resin is easily available from the market. Commercially available cyclic olefin-based resins include “Topas” [Ticona (Germany)]; “Arton” [JSR Corporation]; “ZEONOR” and “ZEONEX” [Nippon Zeon Corporation] “Apel” [Mitsui Chemicals, Inc.] and the like. Such a cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by, for example, known film forming means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin film already marketed with the form of a film can also be used. Examples of such commercially available cyclic olefin resin films include “Essina” and “SCA40” [Sekisui Chemical Co., Ltd.]; “Zeonor Film” [Optes Co., Ltd.]; “Arton Film” [JSR Co., Ltd.] ] Etc. are mentioned.

  The cyclic olefin resin is composed of a polymer or copolymer of a cyclic olefin such as norbornene or a polycyclic norbornene monomer. The cyclic olefin polymer or copolymer may partially contain a ring-opening portion or may be hydrogenated. Further, the cyclic olefin resin is, for example, a copolymer of a cyclic olefin and a chain olefin or a vinylated aromatic compound (such as styrene) in that the transparency is not significantly impaired or the hygroscopicity is not significantly increased. It may be. The cyclic olefin resin may have a polar group introduced into its molecule.

  Examples of the chain olefin include ethylene and propylene. 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 copolymer is usually 50 mol% or less, preferably 15 to 50 mol% with respect to all the structural units of the cyclic olefin resin. When the cyclic olefin-based resin is a terpolymer obtained from a cyclic olefin, a chain olefin, and a vinylated aromatic compound, the content ratio of the structural unit derived from the chain olefin is that of the cyclic olefin resin. It is 5-80 mol% normally with respect to all the structural units, and the content rate of the structural unit derived from a vinylated aromatic compound is 5-80 mol% normally. Such a terpolymer cyclic olefin resin has the advantage that the amount of expensive cyclic olefin used can be relatively reduced when the cyclic olefin resin is produced.

Examples of a method for producing a retardation film from a polymer film include a method of stretching a polymer film. Examples of the stretching method include the following methods.
A roll (winding body) in which a polymer film is wound around a roll is prepared, the polymer film is continuously unwound from the wound body, and the unwound polymer film is conveyed to a heating furnace. To do.
The set temperature of the heating furnace is usually in the range of glass transition temperature (° C.) to [glass transition temperature +100] (° C.) of the polymer film, preferably glass transition temperature (° C.) to [glass transition temperature +50] ( ℃) range.
In the heating furnace, when stretching in the direction of travel of the polymer film or in the direction perpendicular to the direction of travel, the transport direction and tension are adjusted to incline at an arbitrary angle to perform uniaxial or biaxial stretching. .
The draw ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.
In addition, the method of stretching in an oblique direction is not particularly limited as long as the orientation axis can be continuously inclined to a desired angle, and a known stretching method can be employed. Examples of such a stretching method include the methods described in JP-A-50-83482 and JP-A-2-113920.

What is necessary is just to determine a draw ratio according to the orientation birefringence of resin which comprises a polymer film.
If the retardation value, which is a value obtained by multiplying the birefringence Δn generated by orientation and the thickness d after stretching, is in the range of 200 to 320 nm with reference to the wavelength of 550 nm, the obtained retardation film is a half-wave plate Can be used as
Such a half-wave plate is preferable as the retardation layer of the polarizing plate.

  The thickness of the polymer film is preferably thin because it is a weight that allows practical handling, and sufficient transparency can be secured, but if it is too thin, the strength decreases and the processability is poor. Tend. 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 of the polymer film before stretching and the stretching ratio.

Liquid crystal retardation layer forming process:
The liquid crystal phase difference layer is formed from a liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound, and preferably, by applying the liquid crystal phase difference layer forming composition on the phase difference film. It is formed from the obtained coating film for forming a liquid crystal retardation layer.
Examples of the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal retardation layer include, for example, formula (I), formula (II), formula (III), formula (IV), formula (V), and formula (VI), respectively. And the compounds represented.

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} represents a polymerizable group.
A ^{11 to} A ^{14 each} represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group is 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 nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom. In addition, —CH ₂ — constituting the divalent alicyclic hydrocarbon group may be replaced with —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 are —O—, —S—, —CO—O—, —O—CO—, —O—CO—O—, —CO—NR ¹⁶ —, —NR ¹⁶ —CO—, — CO-, -CS- or a single bond is represented. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B ¹² .about.B ¹⁶ are each _{independently, -C≡C -, - CH 2 -CH} 2 -, - O -, - S -, - C (= O) -, - C (= O) -O- , —O—C (═O) —, —O—C (═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—, —O—C (═O ^{) -CH = CH -, - CR} a = CR b -, - C≡C -, - representing the ^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 each represent an alkanediyl group having 1 to 20 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms. The hydrogen atom contained may be substituted with a halogen atom. In addition, —CH ₂ — constituting the alkanediyl group may be replaced by —O—, —S—, —NH— or —CO—.
F ¹¹ is 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 hydroxy group, a methylol group, a formyl group, a sulfo group. Represents a group (—SO ₃ H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and —CH ₂ — contained in the alkyl group and alkoxy group is replaced by —O—. Also good. ]

The number of carbon atoms 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. More preferably, 5 or 6 is particularly preferable. A ¹¹ is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

The alkanediyl group having 1 to 20 carbon atoms represented by E ¹¹ and ^{E 12,} an alkanediyl group having 1 to 12 carbon atoms and is preferably linear. —CH ₂ — constituting the alkanediyl group having 1 to 12 carbon atoms may be replaced by —O—.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane -1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12- A linear alkanediyl group having 1 to 12 carbon atoms such as a diyl group; —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 — and the like can be mentioned.

［式（Ｐ−１１）〜（Ｐ−１５）中、
Ｒ^１７〜Ｒ^２１はそれぞれ独立に、炭素数１〜６のアルキル基または水素原子を表わす。］ The polymerizable group represented by P ¹¹ and P ¹² is preferably a radically polymerizable group or a cationically polymerizable group in terms of easy polymerization reaction, and is easy to handle and easy to produce a polymerizable liquid crystal compound itself. Therefore, the polymerizable group is preferably a group represented by the following formula (P-11) to formula (P-15).

[In the formulas (P-11) to (P-15),
R ^{17 to} R ²¹ each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

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

P ¹¹ is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group, or an oxetanyl group.
More preferably, the group represented by P ¹¹ -B ^11- is an acryloyloxy group or a methacryloyloxy group.

  Specific examples of the polymerizable liquid crystal compound include “3.8.6 Network (completely cross-linked type)” of “Liquid Crystal Handbook (Edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. October 30, 2000)”, “6 Among the compounds described in "5.1 Liquid Crystal Material b. Polymerizable Nematic Liquid Crystal Material", compounds having a polymerizable group may be mentioned. Different polymerizable liquid crystal compounds may be used in combination as the polymerizable liquid crystal compound contained in the liquid crystal retardation layer forming composition.

Specific examples of the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal retardation layer include, for example, the following formulas (I-1) to (I-4) and formulas (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) To compounds represented by Formula (VI-6). However, k1 and k2 in the formula represent an integer of 2 to 12. These polymerizable liquid crystal compounds are preferable because they are easy to synthesize and are easily available.

The composition for forming a liquid crystal retardation layer contains a solvent that dissolves the polymerizable liquid crystal compound.
As the solvent, a solvent that is sufficiently soluble in the polymerizable liquid crystal compound and is inactive with respect to the polymerization reaction of the polymerizable liquid crystal compound is selected. Examples of such solvents include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene glycol methyl. Ester solvents such as ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; fats such as pentane, hexane and heptane Aromatic hydrocarbon solvents; aromatic hydrocarbon solvents such as toluene and xylene; acetonitrile, etc. Ether solvents such as tetrahydrofuran and dimethoxyethane; nitrile solvents chloroform and chlorinated hydrocarbon solvents such as chlorobenzene; and the like. These solvents may be used alone or in combination.

  The content ratio of the polymerizable liquid crystal compound in the liquid crystal retardation layer forming composition is usually 1 to 70% by mass, preferably 10 to 40% by mass, based on the solid content of the liquid crystal retardation layer forming composition. is there. If the content ratio of the polymerizable liquid crystal compound is within the above range, it is preferable that so-called dripping does not occur during coating and unevenness does not occur in the obtained liquid crystal retardation layer. Solid content here means the total amount of the component remove | excluding the solvent from the composition for liquid-crystal phase difference layer formation. In addition, when several types of polymeric liquid crystal compound is contained in this composition for liquid crystal phase difference layer formation, the total content rate should just be the said range.

  The composition for forming a liquid crystal retardation layer preferably contains a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of the polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator is preferable in that the polymerization reaction can be initiated under low temperature conditions. Specifically, a compound that generates an active radical or an acid by the action of light is used as a photopolymerization initiator. Among the photopolymerization initiators, those that generate active radicals by the action of light are more preferable.

  Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

    Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

  Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl). ) Benzophenone and 2,4,6-trimethylbenzophenone.

  Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1 -[4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- ON oligomers.

  Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

  Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxy Naphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6 [2- (5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1 , 3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloro Methyl)- - such as [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available photopolymerization initiator can also be used. Commercially available photopolymerization initiators include “Irgacure 907”, “Irgacure 184”, “Irgacure 651”, “Irgacure 819”, “Irgacure 250”, “Irgacure 369” (Ciba Japan Co., Ltd.); “Sake All BZ”, “Sake All Z”, “Sake All BEE” (Seiko Chemical Co., Ltd.); “Kayacure BP100” (Nippon Kayaku Co., Ltd.); “Kayacure UVI-6992” (Dow); “Adekaoptomer SP-152”, “Adekaoptomer SP-170” (ADEKA); “TAZ-A”, “TAZ-PP” (Nihon Shibel Hegner); and “TAZ-104” (Sanwa) Chemical Corporation).

  In order to form a liquid crystal retardation layer from a liquid crystal retardation layer forming composition, a liquid crystal retardation layer forming composition is applied to a retardation layer made of a retardation film, and a liquid crystal retardation layer forming coating film is formed. Form. In this case, it is preferable to form an alignment layer in advance on the surface of the retardation film on which the retardation layer is to be formed, and form a liquid crystal retardation layer thereon. When a composition for forming a liquid crystal retardation layer is formed on the alignment layer formed on the retardation film to form a coating film for forming a liquid crystal retardation layer, the alignment layer has a desired slow axis due to the action of the alignment layer. A liquid crystal retardation layer can be formed.

  The alignment layer preferably has a solvent resistance that does not dissolve when the composition for forming a liquid crystal retardation layer is applied. In addition, heating for removing the solvent from the coating film for forming a liquid crystal retardation layer formed from the composition for forming a liquid crystal retardation layer and orienting the polymerizable liquid crystal compound in the coating film in a desired direction It is preferable to have heat resistance for the treatment.

  Examples of the alignment polymer contained in the alignment layer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule, and polyamic acid that is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, Mention may be made of polymers such as polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. The orientation polymer may be used alone or in combination.

  An orientation layer can be formed on a retardation film by applying the orientation polymer to the retardation film as a composition for forming an orientation layer dissolved in a solvent. Examples of the solvent included in the composition for forming an alignment layer include those that sufficiently dissolve the alignment polymer from those exemplified as the solvent included in the composition for forming a liquid crystal retardation layer.

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

  Examples of the method for forming the alignment layer on the retardation film include a method of applying an alignment layer forming composition on the retardation film and then annealing. The thickness of the alignment layer thus obtained is usually 10 nm to 10000 nm, preferably 10 nm to 1000 nm.

  In order to impart an alignment regulating force to the alignment layer, rubbing can be performed as necessary (rubbing method). By providing the alignment regulating force, the polymerizable liquid crystal compound can be aligned in a desired direction.

  As a method for imparting alignment regulating force by the rubbing method, for example, a rubbing cloth is wound, a rotating rubbing roll is prepared, and a laminate in which a coating film for forming an alignment layer is formed on a retardation film. There is a method of bringing the coating film for forming the alignment layer into contact with the rotating rubbing roll by placing it on a stage and transporting it toward the rotating rubbing roll.

  The alignment layer is also formed from a photo-induced alignment material that generates alignment regulating force by light irradiation (hereinafter, the alignment layer formed by irradiating the light-induced alignment material with light is referred to as a photo-alignment layer). Sometimes). An alignment layer is formed by forming a photo-alignment-inducing layer from a photo-induced alignment material, irradiating polarized light (preferably, polarized UV), and applying an alignment regulating force to the photo-alignment-inducing layer. Therefore, it is more preferable because the orientation direction of the polymerizable liquid crystal compound can be freely controlled by selecting the direction of polarized light to be irradiated. The photo-induced alignment material includes a polymer or monomer having a photoreactive group. Hereinafter, the composition for forming an alignment layer containing a photo-induced 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 that generates liquid crystal alignment ability when irradiated with light (light irradiation). Specifically, it causes photoreactions that are the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction caused by light irradiation. is there. Among the photoreactive groups, those utilizing a dimerization reaction or a photocrosslinking reaction are preferable because they are excellent in orientation and maintain a liquid crystal state when a polarizing layer is formed. As the photoreactive group capable of causing the above reaction, those having an unsaturated bond, particularly a double bond are preferable, and a carbon-carbon double bond (C═C bond), a carbon-nitrogen double bond (C = N bond), a nitrogen-nitrogen double bond (N = N bond), and a photoreactive group having at least one selected from the group consisting of a carbon-oxygen double bond (C = O bond) are particularly preferable.

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group and a formazan group, and those having a basic structure of azoxybenzene. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.
Among them, a photoreactive group capable of photodimerization is preferable, and a cinnamoyl group and a chalcone group have a relatively small amount of polarized light irradiation necessary for photoalignment, and a photoalignment layer excellent in thermal stability and temporal stability is obtained. It is preferable because it is easily formed. Further, as the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  Examples of the solvent for the composition for forming a photo-alignment layer include those that sufficiently dissolve the photo-induced alignment material from those exemplified as the solvent contained in the composition for forming a liquid crystal retardation layer.

  The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photoalignment layer can be appropriately adjusted depending on the type of the polymer or monomer having the photoreactive group and the thickness of the photoalignment layer to be produced. Expressed in terms of solid content concentration, it is preferably at least 0.2 mass%, particularly preferably in the range of 0.3-10 mass%. In addition, the composition for forming a photo-alignment layer may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer as long as the characteristics of the photo-alignment layer are not significantly impaired.

  Examples of the method for applying the alignment layer forming composition or the photo alignment layer forming composition on the retardation film include spin coating method, extrusion method, gravure coating method, die coating method, bar coating method and applicator. A known method such as a coating method such as a printing method or a printing method such as a flexo method is employed.

Examples of a method for forming a photo-alignment layer from a photo-alignment inducing layer formed by applying a composition for forming a photo-alignment layer on a retardation film include the following methods.
First, the solvent contained in the said coating film is removed by annealing the coating film obtained by apply | coating the composition for photo-alignment layer formation. Appropriate conditions are employed for the temperature and time in the annealing treatment depending on the type of solvent or the like contained in the composition for forming a photo-alignment layer.

  An alignment regulating force can be imparted by irradiating the photo-alignment inducing 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 irradiate polarized light in a direction that is neither horizontal nor perpendicular to the slow axis of the retardation film as the substrate, and is substantially 60 ° or −60 to the slow axis of the retardation film. Irradiation in the direction of ° is preferable.

  The thickness of the alignment layer thus formed is determined such that the total thickness of the circularly polarizing plate does not significantly exceed the range described below, but is usually 10 to 1000 nm. The thickness of the alignment layer can be controlled by the thickness of the coating film formed by applying the alignment layer forming composition. The thickness of the alignment layer is determined by measurement with an interference film thickness meter, a laser microscope, or a stylus thickness meter.

  Subsequently, a liquid crystal retardation layer forming composition is applied on the formed alignment layer. As a coating method, the same thing as what was illustrated as a coating method of the composition for alignment layer formation is mentioned.

  Next, a dry film is formed by drying and removing the solvent contained in the coating film for forming a liquid crystal retardation layer formed on the alignment layer. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.

  Subsequently, the dry film is irradiated with light to polymerize the polymerizable liquid crystal compound in the dry film to form a liquid crystal retardation layer. The light applied to the dry film is appropriately selected from visible light, ultraviolet light, laser light, or active electron beam according to the type of polymerizable liquid crystal compound or the type of polymerization initiator contained in the dry film and the amount thereof. The Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that apparatuses widely used in the field as photopolymerization apparatuses can be used. Therefore, the kind 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 performed by ultraviolet light.

  The thickness of the liquid crystal retardation layer thus formed is determined so that the total thickness of the circularly polarizing plate does not significantly exceed the range described later, but is usually 0.5 to 5.0 μm. The thickness of the liquid crystal retardation layer is controlled by controlling the thickness of the coating film for forming the liquid crystal retardation layer formed by applying the composition for forming the liquid crystal retardation layer and the birefringence of the polymerizable liquid crystal compound. can do.

Polarizing layer forming process:
Next, a laminate in which the liquid crystal retardation layer and the retardation film are laminated, preferably the retardation film side of the laminate in which the liquid crystal retardation layer, the alignment layer, and the retardation film are laminated (that is, A polarizing layer is formed on the surface opposite to the surface on which the liquid crystal retardation layer is provided.

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

  As said dichroic dye, what has a maximum absorption wavelength ((lambda) MAX) in the range of 300-700 nm is preferable. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, and among them, azo dyes are preferable. Examples of the azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred.

Examples of the azo dye include a compound represented by the formula (1) (hereinafter sometimes referred to as “compound (1)”).
_{^{A 1 (-N = N-A}} 2) p -N = N-A 3 (1)
[In Formula (1),
A ¹ and A ³ are each independently 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. Represents. A ² represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic ring which may have a substituent. Represents a group. p represents an integer of 1 to 4. When p is an integer greater than or equal to ² , several A2 may mutually be same or different. ]

  Examples of the monovalent heterocyclic group include groups in which one hydrogen atom has been removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole and benzoxazole. A group obtained by removing two hydrogen atoms from a heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of the heterocyclic compound are as described above.

As a substituent which the phenyl group, naphthyl group and monovalent heterocyclic group in A ¹ and A ³ and the p-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ² optionally have Is an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; Nitro group; halogen atom; substituted or unsubstituted amino group such as amino group, diethylamino group and pyrrolidino group (substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two This means an amino group in which substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, and the unsubstituted amino group is —NH ₂ .

［式（１−１）〜（１−６）中、
Ｒ^１〜Ｒ²⁰は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜４のアルコキシ基、シアノ基、ニトロ基、置換又は無置換のアミノ基（置換アミノ基及び無置換アミノ基の定義は前記のとおり）、塩素原子又はトリフルオロメチル基を表す。
ｎ１〜ｎ４は、互いに独立に０〜３の整数を表す。
ｎ１が２以上である場合、複数のＲ^２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＲ^６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＲ^９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＲ¹⁴は互いに同一でも異なっていてもよい。］ Of the compounds (1), compounds represented by the following formulas (1-1) to (1-6) are preferable.

[In the formulas (1-1) to (1-6),
R ^{1 to} R ²⁰ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (a substituted amino group and As defined above, the unsubstituted amino group represents a chlorine atom or a trifluoromethyl group.
n1 to n4 each independently represents an integer of 0 to 3.
when n1 is 2 or more, the plurality of R ² may be the same or different from each other;
when n2 is 2 or more, the plurality of R ⁶ may be the same or different from each other;
when n3 is 2 or more, the plurality of R ⁹ may be the same or different from each other;
When n4 is 2 or more, the plurality of R ¹⁴ may be the same as or different from each other. ]

  The polarizing layer forming composition preferably contains a polymerizable liquid crystal compound in addition to the dichroic dye. The definition of the polymerizable liquid crystal compound is the same as the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal retardation layer, but the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer shows a liquid crystal state of a smectic phase. Those exhibiting a liquid crystal state of a higher order smectic phase are more preferable.

  Higher smectic phases are smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase and smectic L phase, among others Smectic B phase, Smectic F phase and Smectic I phase are more preferable. It is particularly preferable that the smectic liquid crystal phase exhibited by the polymerizable liquid crystal compound is a higher order smectic phase because a polarizing layer having a higher degree of alignment order can be formed. In addition, such a polarizing film having a high degree of orientational order can obtain a Bragg peak derived from a higher order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from a plane structure of molecular orientation. According to the polarizing layer forming composition of the present invention, the polarizing film having a periodic interval of 3.0 to 5.0 mm is obtained. Can do.

Examples of the polymerizable liquid crystal compound include the same ones as the polymerizable liquid crystal compound included in the liquid crystal retardation layer forming composition. Preferably, a compound represented by the formula (2) (hereinafter sometimes referred to as “compound (2)”) may be mentioned. The compound (2) is preferable because it easily exhibits a smectic liquid crystal state.
^{U 1 -V 1 -W 1 -X 1} -Y 1 -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (2)
[In 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. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. —CH ₂ — constituting the optionally substituted cyclohexane-1,4-diyl group may be replaced by —O—, —S— or —NR—. R is a C1-C6 alkyl group or a phenyl group.
Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or —CR ^a ═N— is represented. 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 each independently represent a single bond, —O—, —S—, —COO— or —OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or -NH- may be substituted. ]

In the compound (2), as described above, it is preferable that at least ^{two of} X ¹ , X ² and X ³ are 1,4-phenylene groups 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. It is more preferable that the trans-cyclohexane-1,4-diyl group which may have a non-substituted group.

  The 1,4-phenylene group which may have a substituent or the substituent which the cyclohexane-1,4-diyl group optionally has is a C 1 -C 1 such as a methyl group, an ethyl group and a butyl group. 4 alkyl group; cyano group; halogen atom and the like.

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 preferably a polymerizable group. U ¹ and U ² are both preferably a polymerizable group, and more preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. Use of a polymerizable liquid crystal compound having a photopolymerizable group is advantageous in that the compound (2) can be polymerized under a lower temperature condition.

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

In the alkanediyl group having 1 to 20 carbon atoms which may have a substituent represented by V ¹ and V ^2, examples of the alkanediyl group having 1 to 20 carbon atoms include a methylene group, an ethylene group, and propane-1,3. -Diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane Examples include -1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group, and icosane-1,20-diyl group. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably alkanediyl groups having 6 to 12 carbon atoms.
Examples of the substituent optionally contained in the optionally substituted alkanediyl group having 1 to 20 carbon atoms include a cyano group and a halogen atom. The alkanediyl group is unsubstituted. It is preferably an unsubstituted and linear alkanediyl group.

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

  Examples of compound (2) include compounds represented by formulas (2-1) to (2-23). When a specific example of the compound (2) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

The polymerizable liquid crystal compounds contained in the polarizing layer forming composition may be used alone or in combination. When combining, it is preferable that at least 1 type is a compound (2).
The mixing ratio when 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. is there.
In the polymerization of the polarizing layer forming composition, the phase transition temperature of the polymerizable liquid crystal compound contained in the polarizing layer forming composition is obtained in advance, and the polymerizable liquid crystal compound is polymerized under a temperature condition lower than the phase transition temperature. In addition, components other than the polymerizable liquid crystal compound are adjusted. In addition, also when using the mixture of 2 or more types of polymeric liquid crystal composition for the composition for polarizing layer formation, after calculating | requiring the phase transition temperature of the said 2 or more types of polymeric liquid crystal compound, it implemented similarly. To do.

  Among the exemplified compounds (2), the formula (2-2), the formula (2-3), the formula (2-4), the formula (2-6), the formula (2-7), and the formula (2- 8), the compounds represented by formula (2-13), formula (2-14) and formula (2-15) are preferred. These polymerizable liquid crystal compounds can be polymerized by mixing two or more of them, under a temperature condition lower than the phase transition temperature, that is, while sufficiently maintaining the liquid crystal state of the higher order smectic phase. More specifically, these polymerizable liquid crystal compounds can be polymerized under a temperature condition of 70 ° C. or lower, preferably 60 ° C. or lower, while sufficiently maintaining a liquid crystal state of a higher order smectic phase.

  70-99.9 mass% is preferable with respect to solid content of the composition for polarizing layer formation, and, as for the content rate of the polymeric liquid crystal compound in the composition for polarizing layer formation, 90-99.9 mass% is more preferable. If the content rate of a polymeric liquid crystal compound is in the said range, there exists a tendency for the orientation of a polymeric liquid crystal compound to become high. Here, solid content means the total amount of the component remove | excluding the solvent from the composition for polarizing layer formation.

  The polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is, for example, Lub et al. Recl. Trav. Chim. It is manufactured by a known method described in 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 capable of completely dissolving the polymerizable liquid crystal compound and the dichroic dye, and is preferably a solvent inert to the polymerization reaction of the polymerizable liquid crystal compound. The thing similar to the solvent which the said composition for liquid crystal phase difference layer formation contains is mentioned.

  As for content of a solvent, 50-98 mass% is preferable with respect to the total amount of the said composition for polarizing layer formation. In other words, the solid content in the composition for forming a polarizing layer is preferably 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 polarizing layer forming composition and flattening the polarizing layer forming coating film obtained by coating the polarizing layer forming composition. Activators can be mentioned. Preferable leveling agents include a leveling agent having a polyacrylate compound as a main component and a leveling agent having a fluorine atom-containing compound as a main component.

  Leveling agents mainly composed of polyacrylate compounds include “BYK-350”, “BYK-352”, “BYK-353”, “BYK-354”, “BYK-355”, “BYK-358N”, “ BYK-361N ”,“ BYK-380 ”,“ BYK-381 ”,“ BYK-392 ”[BYK Chemie], and the like.

  Leveling agents mainly composed of fluorine atom-containing compounds include "Megafac R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482" and the same "F-483" [DIC Corporation]; "Surflon S-381", "S-382", "S-383", "S-393", "SC-101", "SC" -105 "," KH-40 "and" SA-100 "[AGC Seimi Chemical Co., Ltd.];" E1830 "," E5844 "[Daikin Fine Chemical Laboratory Co., Ltd.];" F-top EF301 "," EF303 " ", EF351" and "EF352" [Mitsubishi Materials Child Kasei Co., Ltd.] and the like.

  When 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 with respect to 100 parts by mass of the polymerizable liquid crystal compound. The amount is 3 parts by mass or less. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound, and the obtained polarizing film tends to be smoother. When the content of the leveling agent with respect to the polymerizable liquid crystal compound exceeds the above range, unevenness tends to occur in the obtained polarizing layer. The polarizing layer forming composition may contain two or more leveling agents.

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

  Examples of the polymerization initiator include those similar to the polymerization initiator contained in the liquid crystal retardation layer forming composition.

  When the composition for forming a polarizing layer contains a polymerization initiator, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer. The content of the polymerization initiator with respect to 100 parts by mass in total is usually 0.1 to 30 parts by mass, preferably 0.5 to 15 parts by mass, and more preferably 0.5 to 8 parts by mass. If the content of the polymerizable initiator is within this range, it can be polymerized without disturbing the orientation 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 contain a photosensitizer. Examples of the photosensitizer include anthracene such as xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone and 2-isopropylthioxanthone); anthracene and anthracene containing an alkoxy group (for example, dibutoxyanthracene). Compounds; phenothiazine, rubrene and the like.

  When the composition for forming a polarizing layer contains 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 accelerated. 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 together. 1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass.

  The composition for forming a polarizing layer may contain a polymerization inhibitor in order to allow the polymerization reaction of the polymerizable liquid crystal compound to proceed stably. The progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

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

  When the composition for forming a polarizing layer contains a polymerization inhibitor, its content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound to be used in combination, the amount of photosensitizer used, etc. It is 0.1-30 mass parts normally with respect to 100 mass parts of liquid crystal compounds, Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. If the content of the polymerization inhibitor is within the above range, it can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound contained in the polarizing layer forming composition, 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, but is usually 0.1 mass with respect to a total of 100 parts by mass of the polymerizable liquid crystal compound. Part to 50 parts by weight, preferably 0.1 part to 20 parts by weight, and more preferably 0.1 part to 15 parts by weight. If the content of the dichroic dye is within this range, it is preferable because the polymerizable liquid crystal compound can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound.

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

  First, a polarizing layer forming composition is applied on a retardation film to form a polarizing layer forming coating film. In this case, it is preferable to previously provide an alignment layer on the surface on which the polarizing layer on the retardation film is to be formed. Examples of the method for forming the alignment layer include the same method as the method for forming the alignment layer described in the description of the liquid crystal retardation layer formation. The alignment layer provided between the polarizing layer and the retardation film is preferably a photo-alignment layer, similar to the alignment layer provided between the liquid crystal retardation layer and the retardation film. The thickness of the alignment layer provided between the polarizing layer and the retardation film is determined such that the total thickness of the circularly polarizing plate does not significantly exceed the range described later, but is usually 10 to 1000 nm. In the present invention, it is necessary to irradiate polarized light so that it is neither horizontal nor perpendicular to the slow axis of the retardation film as a substrate, and is substantially 15 ° or −15 with respect to the slow axis of the retardation film. Irradiation in the direction of ° is preferable.

  Examples of the method for applying the polarizing layer forming composition on the alignment layer include the same methods as those exemplified as the application method for the alignment layer forming composition.

  Next, a dry film is formed by drying and removing the solvent under conditions where the polymerizable liquid crystal compound contained in the polarizing layer-forming coating film is not polymerized. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. Subsequently, it is preferable that the liquid crystal state of the polymerizable liquid crystal composition contained in the dry film is changed to a nematic phase and then the nematic phase is changed to a smectic phase. In order to form a smectic phase via the nematic phase in this way, for example, the polymerizable liquid crystal compound contained in the dry film is heated to a temperature higher than the temperature at which the liquid crystal state of the nematic phase transitions, and then the polymerizable smectic A method in which the liquid crystal compound is cooled to a temperature at which the liquid crystal state of the smectic phase is exhibited is employed.

  When the polymerizable liquid crystal compound in the dry film is changed to a smectic liquid crystal state or a nematic liquid crystal state via a nematic liquid crystal state, the liquid crystal state is controlled by measuring the phase transition temperature of the polymerizable liquid crystal compound. Conditions (heating conditions) can be easily obtained.

  Next, the polymerization process of the polymerizable liquid crystal compound will be described. Here, the composition for forming a polarizing layer contains a photopolymerization initiator, and after the liquid crystal state of the polymerizable liquid crystal compound in the dry film is changed to a smectic phase, the polymerizable property is maintained while maintaining the liquid crystal state of the smectic phase. A method for photopolymerizing the liquid crystal compound will be described in detail. In photopolymerization, the light applied to the dry film includes the type of photopolymerization initiator contained in the dry film, or the type of polymerizable liquid crystal compound (particularly, the type of polymerizable group possessed by the polymerizable liquid crystal compound) and its Depending on the amount, it can be carried out by light or an active electron beam selected from the group consisting of visible light, ultraviolet light and laser light. Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that apparatuses widely used in the field as photopolymerization apparatuses can be used. Therefore, it is preferable to select the type of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the polarizing layer forming composition so that the photopolymerization can be performed with ultraviolet light. Moreover, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a dry film with a suitable cooling means with ultraviolet light irradiation. By adopting such a cooling means, if the polymerizable liquid crystal compound can be polymerized at a lower temperature, there is an advantage that a polarizing layer can be appropriately formed even if a retardation film having relatively low heat resistance is used. . In the photopolymerization, a patterned polarizing layer can be obtained by masking or developing.

  By performing photopolymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining a liquid crystal state of a smectic phase, preferably a higher-order smectic phase as exemplified above, and a polarizing layer is formed. . A polarizing layer obtained by polymerizing a polymerizable liquid crystal compound while maintaining a smectic phase liquid crystal state has a conventional host-guest type polarizing layer, that is, a nematic phase liquid crystal state in accordance with the action of the dichroic dye. There is an advantage that polarization performance is much higher than that of a polarizing layer obtained by polymerizing a polymerizable liquid crystal compound or the like while being held. Furthermore, there is an advantage that it is excellent in strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

  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 range described later. For example, the thickness is preferably 0.5 μm to 10 μm, and more preferably 1 μm to 5 μm. preferable.

  As described above, the circularly polarizing plate can be manufactured by the manufacturing method described above. However, in the manufacturing method described here, the order of the liquid crystal retardation layer forming step and the polarizing layer forming step may be reversed. The manufacturing method described so far is based on a method in which the preparation step, the liquid crystal retardation layer formation step, and the polarizing layer formation step are performed in this order, but the preparation step, the polarization layer formation step, and the liquid crystal retardation layer formation. Even when the steps are performed in this order, the present circularly polarizing plate can be obtained. The conditions of each process in this case are as already described.

  As mentioned above, although the outline | summary of the manufacturing method of the circularly-polarizing plate in this invention was demonstrated, when manufacturing this circularly-polarizing plate commercially, the method which can manufacture this polarizing plate continuously is calculated | required. A preferred example of such a continuous production method is a method in the RolltoRoll format (hereinafter, sometimes referred to as “continuous present production method”).

As one embodiment of this continuous manufacturing method, for example,
(I) a step of preparing a roll in which the retardation film is wound around the core;
(Ii) a step of continuously feeding out the retardation film from the roll;
(Iii) The process of apply | coating the composition for alignment layer formation on this retardation film, and forming a 1st alignment layer continuously on this retardation film;
(Iv) A step of applying a composition for forming a liquid crystal retardation layer on the first alignment layer formed in (iii) and continuously forming a liquid crystal retardation layer on the first alignment layer;
(V) A step of applying the composition for forming an alignment layer on the surface of the retardation film opposite to the surface on which the liquid crystal retardation layer is formed, and continuously forming a second alignment layer on the retardation film. ;
(Vi) A step of applying a polarizing layer forming composition on the second alignment layer formed in (v), continuously forming a polarizing layer on the second alignment layer, and obtaining this circularly polarizing plate;
(Vii) A step of winding the present circularly polarizing plate obtained continuously around a second core to obtain a second roll.
Hereinafter, this continuous manufacturing method will be described with reference to FIG. 2. In FIG. 2, the details of the formation of the alignment layer corresponding to (iii) and (v) are omitted.

First, the roll 210 in which the retardation film is wound up in (i) is prepared.
In (ii), the retardation film 110 is continuously unwound from the first roll 210. In (iii), a first alignment layer is formed on one side of the retardation film (not shown), and the alignment layer is on one side. The formed first laminated body 120 is obtained.

  Subsequently, in (iv), a liquid crystal retardation layer is formed on the first alignment layer formed in (iii). Specifically, the liquid crystal retardation layer forming composition is applied using a coating apparatus 211A, and a liquid crystal retardation layer forming coating film is formed on the alignment layer. The formed coating film together with the retardation film passes through the drying device 212A, and the solvent and the like are removed. Furthermore, light irradiation is performed by the light irradiation device 213A, and the second stacked body 140 provided with the retardation layer and the liquid crystal retardation layer is obtained.

  Subsequently, in (v), the second alignment layer is formed by forming a second alignment layer (not shown) on the surface opposite to the surface on which the liquid crystal retardation layer of the second stacked body 140 is provided. A third laminated body 150 is obtained.

  On the second alignment layer of the third laminate 150 obtained in (v), a polarizing layer is formed in (vi). Specifically, the polarizing layer forming composition is applied using the coating apparatus 211B to form a polarizing layer forming coating film on the second alignment layer. The formed coating film together with the retardation film passes through the drying device 212B, and the solvent and the like are removed. Furthermore, light irradiation is performed by the light irradiation device 213B, and this circularly polarizing plate 100 in which the liquid crystal retardation layer, the retardation layer, and the polarizing layer are provided in this order is obtained.

  The obtained circularly polarizing plate 100 is wound around a second core to obtain a second roll 220.

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

  The circularly polarizing plate 100 thus obtained is used as a member of a display device that is further cut to a desired size according to the use of the circularly polarizing plate.

The preferred circularly polarizing plate controls the angle formed by the slow axis of the liquid crystal retardation layer, the retardation layer, and the polarizing layer.
With reference to FIG. 1, the preferable aspect of this circularly-polarizing plate 100 is shown. In the present circularly polarizing plate 100, the retardation layer 1 functions as a half-wave plate, and the liquid crystal retardation layer preferably functions as a quarter-wave plate. Of the angles formed by the slow axis of the liquid crystal retardation layer 2 (¼ wavelength plate) with respect to the slow axis of the retardation layer 1 (½ wavelength plate), a small angle (AG2) and the retardation layer Of the angles formed by the absorption axis or transmission axis of the polarizing layer 3 with respect to the slow axis of 1 (1/2 wavelength plate), the smaller angles (AG3) are preferably the following combinations.
A combination in which AG2 is substantially 60 ° and AG3 is substantially −15 °. A combination in which AG2 is substantially 90 ° and AG3 is substantially −22.5 °.

  This circularly polarizing plate can be used for various 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, an electron emission display device (for example, a field emission display device (FED), a surface field emission display device (SED). )), Electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg, display device having a grating light valve (GLV) display device, digital micromirror device (DMD)), and Examples of the liquid crystal display device include a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, and a projection liquid crystal display device. These display devices may be display devices that display a two-dimensional image. And it may be a stereoscopic display apparatus for displaying a three-dimensional image. Can particularly effectively used in a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescent (EL) display device.

  As an example of a display device including the present circularly polarizing plate, an EL display device (hereinafter, referred to as “the present EL display device” in some cases) will be described with reference to FIG. In the EL display device 30, an organic functional layer 36 that is a light source and a cathode electrode 37 are laminated on a substrate 33 on which a pixel electrode 35 is formed. The circularly polarizing plate 100 is disposed on the opposite side of the organic functional layer 36 across the substrate 33. By applying a positive voltage to the pixel electrode 35 and a negative voltage to the cathode electrode 37 and applying a direct current between the pixel electrode 35 and the cathode electrode 37, the organic functional layer 36 emits light. The organic functional layer 36 that is a light emitting source 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 circularly polarizing plate 100. Although the organic EL display device having the organic functional layer 36 will be described, the present invention may be applied to an inorganic EL display device having an inorganic functional layer.

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

  Next, the circularly polarizing plate 100 is provided on the surface of the substrate 33 opposite to the surface on which the thin film transistor 40 is provided. In that case, the retardation layer 2 of the present circularly polarizing plate 100 is disposed on the substrate 33 side.

  Next, members other than the circularly 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; a plastic substrate.
Although not shown, a heat conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (DLC or the like). When the pixel electrode 35 is a reflection type, light is emitted in the opposite direction to the substrate 33. Therefore, not only a transparent material but also a non-permeable material such as stainless steel can be used. A single substrate may be formed, or a plurality of substrates may be bonded together with an adhesive to form a laminated substrate. Further, these substrates are not limited to plate-like ones, and may be films.

  For example, a polycrystalline silicon transistor may be used as the thin film transistor 40. 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. The size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

  On the substrate 33, wiring electrodes of the thin film transistor 40 are provided. The wiring electrode has a low resistance and has a function of suppressing resistance by being electrically connected to the pixel electrode 35. In general, the wiring electrode includes Al, Al and transition metals (except for Ti), Ti or Those containing any one or more of titanium nitride (TiN) are used.

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 of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), a photoresist, a polyimide. In addition, any film may be used as long as it has insulating properties, such as a coating film of a resin material such as an acrylic resin.

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

  Next, an EL element including a pixel electrode 35 that is a transparent electrode, an organic functional layer 36 that is a light emission source, and a cathode electrode 37 will be described. Each of the organic functional layers 36 includes at least one hole transport layer and a light emitting layer, and sequentially includes, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO _2, and In ₂ O _3. ITO and IZO are particularly preferable. The pixel electrode 35 only needs to have a certain thickness or more that can sufficiently inject holes, 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 and Xe, or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 37, for example, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, and Zr may be used. In order to improve the operational stability of the electrode, it is preferable to use a two-component or three-component alloy system selected from the exemplified metal elements. Examples of the alloy system include Ag · Mg (Ag: 1 to 20 at%), Al·Li (Li: 0.3 to 14 at%), In · Mg (Mg: 50 to 80 at%), and Al · Ca (Ca: 5 to 20 at%) is preferable.
The cathode electrode 37 is formed by vapor deposition or sputtering. The thickness of the cathode electrode 37 is 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, and the hole transport layer has a function of transporting holes and a function of blocking electrons. Also called transport layer.
The thickness of the light-emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection / transport layer are not particularly limited and may vary depending on the formation method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. For the formation of the hole injecting and transporting layer, the light emitting layer and the electron injecting and transporting layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

  Examples of the organic functional layer 36 that is a light emission source include those that use light emission (fluorescence) from singlet excitons, those that use light emission (phosphorescence) from triplet excitons, and those from singlet excitons. Including those using luminescence (fluorescence) and those using triplet excitons (phosphorescence), those formed with organic matter, those formed with organic matter and those formed with inorganic matter , A high molecular material, a low molecular material, a high molecular material and a low molecular material, and the like can be used. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials for EL elements can be used for the EL display device 30.

  A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing lid 39. This is because the organic functional layer 36 is vulnerable to humidity. Moisture is absorbed by the desiccant 38 to prevent the organic functional layer 36 from deteriorating.

FIG. 4 is a schematic diagram showing a cross-sectional configuration of another aspect of the EL display device 30. This EL display device 30 has a sealing structure using a thin film sealing film 42, and can also obtain emitted light from the opposite surface of the array substrate.
As the thin film sealing film 42, it is preferable to use a DLC film obtained by evaporating DLC (diamond-like carbon) on a film of an electrolytic capacitor. The DLC film has a characteristic that moisture permeability is extremely poor, and has high moisture-proof performance. Further, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. Further, the thin film sealing film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

  The EL display device provided with the circularly polarizing plate 100 has an excellent antireflection performance because the circularly polarizing plate 100 does not have a black display color when observed in a bright place and has characteristics as a display device. It will be excellent.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and parts by mass.

重合開始剤；
２−メチル−１−[４−(メチルチオ)フェニル]−２−モリフォリノプロパン−１−オン
（イルガキュア９０７；チバ スペシャルティケミカルズ社製） ３部
溶剤；シクロペンタノン ２５０部 Example 1
[Preparation of liquid crystal retardation layer forming composition (1)]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a liquid crystal retardation layer forming composition (1).
Polymerizable liquid crystal compound; trade name LC-242 manufactured by BASF Corporation 100 parts

A polymerization initiator;
2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) 3 parts Solvent; 250 parts of cyclopentanone

溶剤；シクロペンタノン ９５部 [Preparation of composition (1) for forming photo-alignment layer]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a composition (1) for forming a photo-alignment layer.

Photo-induced alignment material; 5 parts

Solvent: 95 parts of cyclopentanone

化合物（２−７） ２５部

二色性色素；
二色性色素（１−１−１） ２．５部

二色性色素（１−１−２） ２．５部

二色性色素（１−３−１） ２．５部

重合開始剤；
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９；チバ スペシャルティケミカルズ社製） ６部
レベリング剤；
ポリアクリレート化合物（ＢＹＫ−３６１Ｎ；ＢＹＫ−Ｃｈｅｍｉｅ社製）
１．５部
溶剤；シクロペンタノン ２５０部 [Preparation of polarizing layer forming composition (1)]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a polarizing layer forming composition containing a dichroic dye.
Polymerizable liquid crystal compound;
Compound (2-6) 75 parts

Compound (2-7) 25 parts

Dichroic dyes;
Dichroic dye (1-1-1) 2.5 parts

Dichroic dye (1-1-2) 2.5 parts

Dichroic dye (1-3-1) 2.5 parts

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

(Measurement of phase transition temperature)
The polarizing layer forming composition (1) was applied to glass and dried to prepare a sample, and the phase transition temperature was confirmed by texture observation with a polarizing microscope. The dried film obtained from the composition for forming a polarizing layer (1) was heated to 140 ° C., and at the time of cooling, the phase transitioned to the nematic phase at 108 ° C., the phase transition to the smectic A phase at 101 ° C., 76 Phase transition to smectic B phase at ℃.

[Manufacture of this circularly polarizing plate]
1. Formation of Second Alignment Layer A half-wave plate (Zeonor film, Nippon Zeon Co., Ltd., in-plane retardation value Ro: 270 nm), which is a uniaxially stretched film of a cyclic olefin resin, was used as the retardation film.
On the retardation film, the composition (1) for forming a photo-alignment layer was applied by a bar coating method, and dried by heating in a drying oven at 60 ° C. for 1 minute. The obtained light distribution-inducing layer was irradiated with polarized UV to form a photo-alignment layer. Polarized UV was irradiated using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.) Under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ. The polarization direction of the polarized UV was set to 15 ° with respect to the slow axis of the retardation layer made of the retardation film.

2. Formation of Polarizing Layer A polarizing layer-forming composition (1) is applied onto the second alignment layer by a bar coating method, heated and dried in a 120 ° C. drying oven for 1 minute, and then cooled to room temperature to form a dry film. Obtained. Using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.), The obtained dried film was irradiated with ultraviolet rays having an exposure amount of 1200 mJ / cm ² (365 nm standard) to form a polarizing layer, and polarized light A layered retardation film (1) was obtained. The thickness of the polarizing layer at this time was 1.9 μm as measured by a laser microscope (OLS3000 manufactured by Olympus Corporation).

3. Formation of first alignment layer On the surface opposite to the polarizing layer of the obtained retardation film with a polarizing layer (1), the composition for forming a photoalignment layer (1) was applied by a bar coating method, Heat drying in a drying oven for 1 minute. Thereafter, the obtained photo-alignment inducing layer was irradiated with polarized UV to form a photo-alignment layer. Polarized UV was irradiated under the same conditions as the second alignment layer. The polarization direction of the polarized UV was 60 ° with respect to the slow axis of the retardation layer made of the retardation film (in this case, the absorption axis of the polarizing film was −15 °).

4). Formation of Retardation Layer A liquid crystal retardation layer forming composition (1) is applied onto the first alignment layer by a bar coating method, heated and dried in a drying oven at 50 ° C. for 1 minute, and then cooled to room temperature. A dry film was obtained. Using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), an ultraviolet ray having an exposure amount of 500 mJ / cm ² (365 nm standard) is irradiated to the obtained dry film to form a liquid crystal retardation layer. This circularly-polarizing plate (1) was obtained. The thickness of the retardation layer at this time was 1.0 μm when measured with a laser microscope (OLS3000 manufactured by Olympus Corporation). It was 46 micrometers when the total thickness of this circularly-polarizing plate (1) was measured with the contact-type film thickness meter.

[Evaluation of this circularly polarizing plate (1)]
1. X-ray diffraction measurement X-ray diffraction measurement was performed on the polarizing layer of the circularly polarizing plate (1) using an X-ray diffractometer X'Pert PRO MPD (Spectris Co., Ltd.). X-rays generated under the conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV using Cu as a target are rubbed through a fixed divergence slit 1/2 ° (the rubbing direction of the alignment layer below the polarizing layer in advance) Ask for.
), And scanning was performed in steps of 2θ = 0.01671 ° in a scanning range of 2θ = 4.0 to 40.0 °, and as a result, a peak half-value width (about 2θ = 20.12 °) was obtained. A sharp diffraction peak (Bragg peak) of (FWHM) = about 0.29 ° was obtained. In addition, the same result was obtained even when incident from the vertical direction of alignment. The order period (d) obtained from the peak position is about 4.4 mm, and it was found that a structure reflecting a higher-order smectic phase was formed.

2. Measurement of reflectance In order to confirm the usefulness of the present circularly polarizing plate (1), the reflectance was measured as follows. The liquid crystal phase difference layer side of this produced circularly-polarizing plate (1) and the reflection plate (mirror surface aluminum plate) were bonded using an adhesive to prepare a measurement sample.
Using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation), light in the wavelength range of 400 to 700 nm is incident on the measurement sample in a normal direction of 12 ° in 2 nm steps, and the reflectance of the reflected light is measured. did. When the reflectance at the time of measuring by arranging only the reflector without attaching the circularly polarizing plate (1) is 100%, the light in the range of 400 to 700 nm is 1 to 10% at any wavelength. A sufficient antireflection characteristic was obtained over the entire visible light range.

Example 2
In the same manner as in Example 1, a photo-alignment layer (the polarization direction of polarized UV is 60 ° with respect to the slow axis of the phase-difference film) is formed on one surface of the retardation film, and a liquid crystal is formed on the photo-alignment layer. A retardation layer was formed. Thereafter, a photo-alignment layer (the polarization direction of polarized UV is 15 ° with respect to the slow axis of the phase difference film) is formed on the surface opposite to the liquid crystal phase difference of the phase difference film with liquid crystal phase difference, and the photo-alignment is performed. A polarizing layer was further formed on the layer to produce this circularly polarizing plate (2).
It was 46 micrometers when the total thickness of this circularly-polarizing plate (2) was measured with the contact-type film thickness meter.
When this circularly polarizing plate (2) was bonded to a reflector using an adhesive in the same manner as in Example 1 and the reflectance was measured, light in the range of 400 to 700 nm was 1 to 10 at any wavelength. %, And sufficient antireflection characteristics were obtained over the entire visible light range.

Comparative Example 1
As the retardation film, a quarter wave plate (Zeonor film, Nippon Zeon Co., Ltd., in-plane retardation value Ro: 138 nm), which is a uniaxially stretched film of a cyclic olefin resin, was used. A photo-alignment layer (the polarization direction of polarized UV is 45 ° with respect to the slow axis of the phase-difference film) is formed on one surface of the phase difference film, and a polarizing layer is further formed on the photo-alignment layer to form a circularly polarizing plate (3) was produced.
The circularly polarizing plate (3) was bonded to the reflector plate using an adhesive in the same manner as in Example 1, and the reflectance was measured. As a result, the light of 500 to 600 nm had a good reflection of about 1 to 10%. It was rate. However, the light of 400 to 500 nm and 600 to 700 nm has a reflectance of 10% or more, and the reflected light is bluish purple, so that a sufficient antireflection function cannot be obtained.

Reference example 1
As a polarizing plate, an iodine-PVA polarizing plate (Sumikaran manufactured by Sumitomo Chemical Co., Ltd., thickness: 105 μm) was cut into small pieces of 100 × 100 mm so that the absorption axis was 0 °, and the half-wave plate used in Example 1 was delayed. Cut into small pieces of 100 × 100 mm so that the axis is 15 °, cut the quarter-wave plate used in Comparative Example 1 into small pieces of 100 × 100 mm so that the slow axis is 75 °, and cut each film. A circularly polarizing plate (4) was produced by laminating sheets using an acrylic pressure-sensitive adhesive (film thickness: 25 μm) so as to be a polarizing plate + ½ wavelength plate + 1/4 wavelength plate.
When the circularly polarizing plate (4) was bonded to the reflector using an adhesive in the same manner as in Example 1 and the reflectance was measured, the light in the range of 400 to 700 nm was 1 to 10 at any wavelength. %, And sufficient antireflection characteristics were obtained over the entire visible light range. However, when the total thickness was measured by a contact-type film thickness meter, it was 240 μm, which was about 5 times the thickness of this circularly polarizing plate (1).

  The circularly polarizing plate (this circularly polarizing plate) of the present invention is useful for organic EL display devices and the like.

DESCRIPTION OF SYMBOLS 1 Phase difference layer 2 Liquid crystal phase difference layer 2A Orientation layer 3 Polarization layer 3A Orientation layer 100 This circular polarizing plate 110 Phase difference film 120 1st laminated body 140 2nd laminated body 150 3rd laminated body 210 1st roll 210A Core 220 Second roll 220A Core 211A, 211B Coating device 212A, 212B Drying device 213A Light irradiation device 213B Light irradiation device 300 Auxiliary roll 30 EL display device 33 Substrate 34 Interlayer insulating film 35 Pixel electrode 36 Organic functional layer 37 Cathode electrode 38 Desiccant 39 Sealing lid 40 Thin film transistor 41 Rib 42 Thin film sealing film

Claims (12)

A liquid crystal retardation layer formed from a composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound; and
A retardation layer comprising a retardation film formed by stretching a polymer film;
The circularly-polarizing plate provided with the polarizing layer formed from the composition for polarizing layer formation containing a dichroic dye in this order.   The circularly polarizing plate according to claim 1, wherein the composition for forming a polarizing layer further contains a polymerizable liquid crystal compound.   The circularly polarizing plate according to claim 2, wherein the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is a compound showing a liquid crystal state of a smectic phase.   The circularly polarizing plate according to claim 1, wherein the retardation layer is a half-wave plate and the liquid crystal retardation layer is a quarter-wave plate.   The circularly polarizing plate according to claim 1, wherein the polarizing layer has a Bragg peak in X-ray diffraction measurement. A first alignment layer is provided between the liquid crystal retardation layer and the retardation layer;
The circularly polarizing plate according to claim 1, wherein a second alignment layer is provided between the retardation layer and the polarizing layer.   The circularly polarizing plate according to claim 6, wherein the liquid crystal retardation layer is formed by applying a composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound to the first alignment layer.   The circularly polarizing plate according to 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 is formed from a composition for forming an alignment layer containing a photo-induced alignment material. . The manufacturing method of the circularly-polarizing plate which has the following preparatory processes, a liquid crystal phase difference layer formation process, and a polarizing layer formation process.
Preparation step: a step of preparing a retardation film formed by stretching a polymer film;
Liquid crystal phase difference layer forming step: A liquid crystal phase difference layer forming composition containing a polymerizable liquid crystal compound is applied to one surface of the phase difference film, and the liquid crystal phase difference layer forming coating film is applied to the liquid crystal phase difference layer. Forming a layer;
Polarizing layer forming step: a step of applying a polarizing layer forming composition containing a dichroic dye to the other surface of the retardation film, and forming a polarizing layer from the applied polarizing layer forming coating film.   A display apparatus provided with the circularly-polarizing plate in any one of Claims 1-9, and a display element.   The display apparatus of Claim 11 provided with a liquid crystal cell, an organic EL element, or a touch panel as a display element.

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