KR20130111358A - Circular polarizing plate and method of producing the same - Google Patents

Abstract

PURPOSE: A circular polarizing plate and a manufacturing method thereof are provided to reduce the thickness of the circular polarizing plate by forming a polarizer with lyotropic liquid crystal materials. CONSTITUTION: A liquid crystal phase difference layer (2) is made of a composition which includes polymerized liquid crystal compounds. A phase difference layer (1) is composed of a phase difference film. The phase difference film is formed by extending a high polymer film. A polarizing layer (3) is made of a composition which includes dichromatic pigments.

Description

Circular polarizer and its manufacturing method {CIRCULAR POLARIZING PLATE AND METHOD OF PRODUCING THE SAME}

The present invention relates to a circular polarizing plate, a manufacturing method thereof, and the like.

The broadband circular polarizing plate (circular polarizing plate) used in the liquid crystal display device is 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 and 1 / It is manufactured by bonding together and laminating | stacking with an adhesive or an adhesive so that the angle which the slow axis of a four wavelength plate and the absorption axis of a polarizing film make may be 15 degrees and 75 degrees, respectively. However, such a circular polarizing plate cannot be avoided from becoming thick in its total thickness, which is unsuitable for the circular polarizing plate used in current display devices requiring thinner thickness. Thus, attempts have been made to avoid the lamination by bonding and to form a polarizing film, a half wave plate, or a quarter wave plate by a coating method to produce a thin circular polarizing plate.

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

Patent Document 1: Japanese Patent Publication No. 2009-251288

However, according to the examination by the present inventor, the circularly-polarizing plate described in the said patent document 1 turned out to be inadequate antireflection performance as a circularly polarizing plate.

The present invention includes the following inventions.

[1] a liquid crystal retardation layer formed of 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 in which the polarizing layer formed from the composition for polarizing layer formation containing a dichroic dye is provided 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 described in [2], in which the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer shows a smectic 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 can obtain 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 formed 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 the composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound to a first alignment layer.

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

[9] The circularly polarizing plate according to any one of [6] to [8], wherein the first alignment layer and / or the second alignment layer are formed of a composition for forming an alignment layer containing a photoorganic alignment material.

[10] A method for producing a circularly polarizing plate having the following preparation step, liquid crystal retardation layer forming step, and polarizing layer forming step.

Preparation step: preparing a retardation film formed by stretching a polymer film;

Liquid crystal retardation layer forming process: The process of apply | coating the composition for liquid crystal retardation layer containing a polymeric liquid crystal compound to one surface of the said retardation film, and forming a liquid crystal retardation layer with the coating film for liquid crystal retardation layer formation apply | coated;

Polarizing layer formation process: The process of apply | coating the composition for polarizing layer formation containing a dichroic dye to the other surface of the said retardation film, and forming a polarizing layer with the coating film for polarizing layer formation apply | coated.

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

[12] The display device according to [11], which includes a liquid crystal cell, an organic EL element, or a touch panel as a display element.

According to the present invention, it is possible to provide a circular polarizing plate that is thin and excellent in antireflection performance, a manufacturing method of the circular polarizing plate, and a display device having the circular polarizing plate.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the cross-sectional structure of the circularly polarizing plate of this invention.
It is a schematic diagram which shows an example of the continuous manufacturing method of the circularly-polarizing plate of this invention.
3 is a schematic diagram showing a cross-sectional structure of an EL display device using the circular polarizing plate of the present invention.
4 is a schematic diagram showing a cross-sectional structure of an EL display device using the circular polarizing plate of the present invention.

<Circular Polarizer>

The circularly polarizing plate of the present invention (hereinafter referred to as "present circularly polarizing plate" in some cases),

A liquid crystal retardation layer formed of 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 polarizing layer formed from the composition for polarizing layer formation containing a dichroic dye is provided in this order, It is characterized by the above-mentioned. In the structure of this circular polarizing plate, it is preferable that the retardation layer is a half wave plate, and the liquid crystal retardation layer is a quarter wave plate. First, the manufacturing method of this circular polarizing plate is demonstrated.

1 is a schematic diagram showing the configuration of the circular polarizing plate. The configuration of Fig. 1 (A1) relates to the circular 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. 1 (A2) is a preferred configuration of the circular polarizing plate, and the alignment layer 2A is between the liquid crystal retardation layer 2 and the retardation layer 1, and the polarization layer 3 and the retardation layer 1 The present invention relates to the circular polarizing plate 100 in which an alignment layer 3A is further provided.

<The manufacturing method of this circularly polarizing plate (henceforth called "this manufacturing method")>

The manufacturing method of this circular polarizing plate has the following preparation processes, a liquid crystal phase difference layer formation process, and a polarizing layer formation process normally.

Preparation step: preparing a retardation film formed by stretching a polymer film;

Liquid crystal retardation layer forming process: The process of apply | coating the composition for liquid crystal retardation layer containing a polymeric liquid crystal compound to one surface of the said retardation film, and forming a liquid crystal retardation layer with the coating film for liquid crystal retardation layer formation apply | coated;

Polarizing layer formation process: The process of apply | coating the composition for polarizing layer formation containing a dichroic dye to the other surface of the said retardation film, and forming a polarizing layer with the coating film for polarizing layer formation apply | coated.

Preparation process:

The retardation film prepared in the preparation process of the present production method is formed by stretching a polymer film. It is preferable that this polymer film is a film which has transparency which can transmit light, especially visible light. Transparency means the characteristic that the transmittance | permeability with respect to the light ray over wavelength 380-780 nm becomes 80% or more. As a polymer which comprises such a polymer film, For example, Polyolefin, such as polyethylene, a polypropylene, norbornene-type polymer; Cyclic olefin resins; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid ester; Polyacrylic acid ester; Cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfones; Polyether sulfone; Polyether ketones; Polyphenylene sulfide, polyphenylene oxide, etc. are mentioned. The polymer film which consists of a cellulose ester, cyclic olefin resin, and a polycarbonate is preferable at the point which the easiness of acquisition and transparency are higher.

Especially, since it is easy to control retardation, the polymer film (Hereinafter, it may be called cyclic olefin resin film) comprised with cyclic olefin resin is especially preferable.

Cyclic olefin resin is easily available on the market. Commercially available cyclic olefin resins include "Topas" [Ticona (Germany)]; "Aton" [JSR Corporation]; "ZEONOR" and "ZEONEX" (Nippon Xeon Co., Ltd.); "Apel" (made by Mitsui Chemicals, Inc.), etc. are mentioned. Such cyclic olefin resin can be formed into a film (cyclic olefin resin film) by well-known film forming means, such as a solvent casting method and a melt-extrusion method, for example. Moreover, the cyclic olefin resin film already marketed in the form of a film can also be used. As such a commercially available cyclic olefin resin film, "Esshina" and "SCA40" [Sekisuga Chemical Co., Ltd.]; "Zenooa Film" [Optes Co., Ltd.]; "Aton Film" [JSR Corporation] etc. are mentioned.

Cyclic olefin resin is comprised from the polymer, copolymer, etc. of cyclic olefins, such as a norbornene and a polycyclic norbornene-type monomer. The polymer or copolymer of this cyclic olefin may contain the ring-opening part partially and may be hydrogenated. The cyclic olefin resin may be a copolymer of a cyclic olefin with a linear olefin or a vinylated aromatic compound (styrene or the like), for example, in that it does not significantly impair transparency or does not significantly increase hygroscopicity. Moreover, the polar group may introduce | transduce the cyclic olefin resin in the molecule | numerator.

Ethylene, propylene, etc. are mentioned as said linear olefin. Moreover, styrene, (alpha) -methylstyrene, alkyl substituted styrene, etc. are mentioned as said vinylated aromatic compound. The content rate of the structural unit derived from the cyclic olefin in the said copolymer is 50 mol% or less normally with respect to the total structural units of cyclic olefin resin, Preferably it is 15-50 mol%. When the cyclic olefin 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 usually 5 to 80 mol% with respect to the total structural units of the cyclic olefin resin, and vinylation The content rate of the structural unit derived from an aromatic compound is 5-80 mol% normally. The cyclic olefin resin of such a terpolymer has the advantage that the usage-amount of expensive cyclic olefin can be comparatively small when manufacturing the said cyclic olefin resin.

As a method of manufacturing a retardation film from a polymer film, the method of extending | stretching a polymer film is mentioned. Examples of the stretching method include the following methods.

A roll (winding body) in which a polymer film is wound on a roll is prepared, the polymer film is continuously unwound from such a winding body, and the released polymer film is returned to a heating furnace.

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, and preferably, glass transition temperature (° C) to [glass transition temperature +50] ( ° C).

In the said heating furnace, when extending | stretching to the advancing direction or the direction orthogonal to a advancing direction of a polymer film, the conveyance direction and tension are adjusted, it inclines at arbitrary angles, and uniaxial or biaxial stretching is performed.

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

Moreover, the method of extending | stretching in an oblique direction is not specifically limited as long as it can continuously incline an orientation axis | shaft to a desired angle, A well-known extending | stretching method can be employ | adopted. Examples of such stretching methods include methods described in Japanese Patent Application Laid-Open No. 50-83482 and Japanese Patent Laid-Open No. 2-113920.

A draw ratio may be determined according to the orientation birefringence of the resin constituting the polymer film. If the retardation value which is the value which multiplied the birefringent (DELTA) n which generate | occur | produced by the orientation and the thickness d after extending | stretching is a range of 200-320 nm based on wavelength 550nm, the obtained retardation film can be used as a 1/2 wavelength plate.

Such a half wave plate is preferable as a phase difference layer of this polarizing plate.

The thickness of the polymer film is preferably thin in terms of the weight of practical handling and sufficient transparency. However, when the thickness of the polymer film is too thin, the strength tends to be lowered and the workability is inferior. The suitable thickness of a polymer film is 5-300 micrometers normally, Preferably it is 20-200 micrometers, More preferably, it is 20-100 micrometers. The thickness of the retardation film after extending | stretching is determined by the thickness and draw ratio of the polymer film before extending | stretching.

Liquid crystal retardation layer forming process:

The liquid crystal retardation layer is formed of a composition for forming a liquid crystal retardation layer containing a polymerizable liquid crystal compound, and is preferably formed of a coating film for forming a liquid crystal retardation layer obtained by applying the composition for forming a liquid crystal retardation layer on the retardation film. .

As a polymeric liquid crystal compound contained in the composition for liquid crystal retardation layer formation, the compound represented, for example by Formula (I), Formula (II), Formula (III), Formula (IV), Formula (V), and Formula (VI) Can be mentioned.

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

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

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

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

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

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

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

A ^{11 to} A ¹⁴ represent a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with 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 of 6 and the said C1-C6 alkoxy group may be substituted by the fluorine atom. In addition, -CH ₂ -constituting the divalent alicyclic hydrocarbon group may be substituted 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 to} B ¹⁶ are each independently -C≡C-, -CH ₂ -CH _2- , -O-, -S-, -C (= O)-, -C (= O) -O-,- OC (= O)-, -OC (= O) -O-, -N = CH-, -N = N-, -C (= O) -NR ^16- , -NR ¹⁶ -C (= O)- _{, -OCH 2 -, -OCF 2 -} , -CH 2 O-, -CF 2 O-, -CH = CH-C (= O) -O-, -OC (= O) -CH = CH-, - CR ^a = CR ^b- , -C≡C-, -CR ^a = N- or a single bond. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

E ¹¹ and E ¹² represent an alkanediyl group having 1 to 20 carbon atoms, and the hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atom contained in the alkoxy group is substituted with a halogen atom. It may be. In addition, -CH ₂ -constituting the alkanediyl group may be substituted with -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 hydroxyl group, a methylol group, a formyl group, a sulfo 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 the alkoxy group may be substituted with -O-.]

It is preferable that carbon number of the bivalent aromatic hydrocarbon group and bivalent alicyclic hydrocarbon group represented by A <^11> -A <^14> is 3-18, It is more preferable that it is the range of 5-12, Especially it is 5 or 6 desirable. As A ^{11, a} cyclohexane-1,4-diyl group and a 1,4-phenylene group are preferable.

E ¹¹ and E ¹² is an alkanediyl group having 1 to 12 carbon atoms of straight-chain alkanediyl group having 1 to 20 carbon atoms preferable as represented by. -CH ₂ -constituting an alkanediyl group having 1 to 12 carbon atoms may be substituted with -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-diyl group C1-C12 linear alkanediyl groups, such as these; -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.

As the polymerizable group represented by P ¹¹ and P ¹² , since the polymerization reaction is easy, a radical polymerizable group or a cationic polymerizable group is preferable, and since it is easy to handle and the manufacture itself of the polymerizable liquid crystal compound is also easy, It is preferable that group is group represented by following formula (P-11)-a formula (P-15).

[In Formulas (P-11) to (P-15),

R ¹⁷ to R ²¹ each independently represent an alkyl group having 1 to 6 carbon atoms or a hydrogen atom;

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

It is preferable that P <^11> is group represented by Formula (P-14)-a formula (P-20), and a vinyl group, p-stilbene group, an epoxy group, or an oxetanyl group is more preferable.

It is more preferable that the group represented by P ¹¹ -B ¹¹ -is an acryloyloxy group or a methacryloyloxy group.

As a specific example of a polymerizable liquid crystal compound, "3.8.6 network (complete crosslinking type)" of a liquid crystal handbook (Liquid Crystal Handbook Editing Committee edition, October 30, 2000 issuance), "6.5.1 liquid crystal material b . And a compound having a polymerizable group in the compound described in "Polymerizable nematic liquid crystal material". As a polymerizable liquid crystal compound contained in the composition for liquid crystal retardation layer formation, you may use together the other multiple polymerizable liquid crystal compound.

As a specific example of the polymeric liquid crystal compound contained in the composition for liquid crystal retardation layer formation, the following Formula (I-1)-Formula (I-4), Formula (II-1)-Formula (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 formula (VI-) The compound etc. which are respectively represented by 6) are mentioned. However, in formula, k1 and k2 represent the integer of 2-12. Since these polymerizable liquid crystal compounds are easy to synthesize | combine and easy to obtain, they are preferable.

The composition for liquid crystal retardation layer formation contains the solvent which melt | dissolves a polymeric liquid crystal compound.

As said solvent, the solubility with respect to a polymeric liquid crystal compound is sufficient, and what is inert with respect to the polymerization reaction of a polymeric liquid crystal compound is selected. Examples of such a solvent 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; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl 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; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene; Nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; Chlorine-substituted hydrocarbon solvents, such as chloroform and chlorobenzene, etc. are mentioned. These solvents may be individual or may be combined.

The content rate of the polymeric liquid crystal compound in the composition for liquid crystal phase difference layer formation is 1-70 mass% normally with respect to solid content of the composition for liquid crystal phase difference layer formation, Preferably it is 10-40 mass%. When the content rate of a polymerizable liquid crystal compound is in the said range, what is called a drip at the time of coating and since a nonuniformity does not generate | occur | produce in the obtained liquid crystal phase difference layer, it is preferable. Solid content here means the total amount of the component except the solvent in the composition for liquid crystal retardation layer formation. On the other hand, when several types of polymeric liquid crystal compounds are contained in the said liquid crystal phase difference layer forming composition, the sum total content ratio should just be said range.

It is preferable that the composition for liquid crystal retardation layer formation contains a polymerization initiator. The polymerization initiator is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound. As a polymerization initiator, a photoinitiator is preferable at the point which can start a polymerization reaction under low temperature conditions. Specifically, a compound which generates an active radical or an acid by the action of light is used as the photopolymerization initiator. It is more preferable to generate active radicals by the action of light among the photopolymerization initiators.

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

As a benzoin compound, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. are mentioned, for example.

Examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3 ', 4,4'-tetra (tert-butylperoxycar Carbonyl) benzophenone, 2, 4, 6-trimethyl benzophenone, etc. are mentioned.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, and 2-benzyl-2-dimethylamino-1- (4-morph Polynophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydride Hydroxy-2-methyl-1- [4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1- [4- And oligomers of (1-methylvinyl) phenyl] propan-1-one.

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

Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- (4 -Methoxynaphthyl) -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) Tenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine and the like Can be mentioned.

A photoinitiator can also use a commercially available thing. Commercially available photopolymerization initiators include "Irgacure 907", "Irgacure 184", "Irgacure 651", "Irgacure 819", "Irgacure 250", "Irgacure 369" ( Chiba Japan Co., Ltd .; "Seiquiol BZ", "Seiquiol Z", "Seiquiol BEE" (Seiko Chemical Co., Ltd.); "Kayacure BP100" (Nippon Kayaku Co., Ltd.); "Kayakure UVI-6992" (manufactured by Dausa); "ADEKA OPTOMA SP-152", "ADEKA OPTOMA SP-170" (ADEKA Co., Ltd.); "TAZ-A", "TAZ-PP" (Nippon Siebel Heg Screw); And "TAZ-104" (Sanwa Chemical Co., Ltd.).

In order to form a liquid crystal phase difference layer with the composition for liquid crystal phase difference layer forming, the composition for liquid crystal phase difference layer formation is apply | coated to the phase difference layer which consists of retardation films, and the coating film for liquid crystal phase difference layer formation is formed. In this case, it is preferable to form an alignment layer in advance on the surface where the retardation layer on the retardation film is to be formed, and to form a liquid crystal retardation layer thereon. When the composition for liquid crystal phase difference layer formation is apply | coated and the coating film for liquid crystal phase difference layer formation is formed on the orientation layer formed in the retardation film, the liquid crystal phase difference layer which has a desired slow axis can be formed by the action | action of this alignment layer.

It is preferable that the said alignment layer has solvent tolerance of the grade which does not melt | dissolve by apply | coating the composition for liquid crystal retardation layer formation, etc. Moreover, it is preferable to have heat resistance with respect to the heat processing for removing a solvent from the coating film for liquid crystal phase difference layer formation formed from the composition for liquid crystal phase difference layer formation, orienting the polymeric liquid crystal compound in this coating film to a desired direction.

Examples of the alignment polymer included in the alignment layer include polyamides and gelatin having amide bonds in the molecule, polyimides having imide bonds in the molecule, and polyamic acid, polyvinyl alcohol, alkyl modified polyvinyl alcohol, and polyacrylic acid thereof. And polymers such as amide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters. Especially, polyvinyl alcohol is preferable. The oriented polymers may be used alone or in combination.

As an composition for orientation layer formation which melt | dissolved the orientation polymer in a solvent, an orientation layer can be formed in a retardation film by apply | coating to a retardation film. As a solvent which the composition for orientation layer formation contains, the thing which melt | dissolves an oriented polymer enough in what was illustrated as the solvent which the said composition for liquid crystal phase difference layer formation contains, for example is mentioned.

A commercially available thing can also be used as a composition for orientation layer formation. Examples of commercially available compositions for forming an alignment layer include San Eva (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optoma (registered trademark, manufactured by JSR Corporation), and the like.

As a method of forming an orientation layer in retardation film, the method of apply | coating the composition for orientation layer formation on retardation film, for example, and then annealing is mentioned. The thickness of the alignment layer thus obtained is usually 10 nm to 10000 nm, preferably 10 nm to 1000 nm.

In order to provide orientation control force with respect to an orientation layer, rubbing can be performed as needed (rubbing method). By providing an orientation regulation force, a polymeric liquid crystal compound can be oriented in a desired direction.

As a method of imparting the orientation regulating force by the rubbing method, for example, a rubbing cloth is wound and a rotating rubbing roll is prepared, and a laminating roll on which a coating film for forming an alignment layer is formed on a phase difference film is placed on a stage, and the rotating rubbing roll is rotated. By conveying toward the surface, the method of making the coating film for oriented layer formation and the rotating rubbing roll contact is mentioned.

In addition, the alignment layer is also formed of a photoorganic alignment material that generates an alignment regulating force by light irradiation (hereinafter, the alignment layer formed by light irradiation with the photoorganic alignment material may be referred to as a photoalignment layer). The alignment layer is formed by forming a photoalignment organic layer with a photoorganic alignment material, irradiating polarized light (preferably polarized light UV), and applying an orientation regulating force to the photoalignment organic layer. Therefore, since the orientation direction of a polymeric liquid crystal compound can be freely controlled by selecting the direction of polarization to irradiate, it is more preferable. Photoorganic oriented materials include polymers or monomers having photoreactive groups. Hereinafter, the composition for orientation layer formation containing a photoorganic orientation material and a solvent may be called the composition for photoalignment layer formation. A photoreactive group means the group which produces the liquid-crystal orientation ability by irradiating light (light irradiation). Specifically, a photoreaction that causes the origin of liquid crystal alignment capability such as alignment organic or isomerization reaction, dimerization reaction, photocrosslinking reaction or photolysis reaction of molecules generated by irradiation with light is produced. Among these photoreactive groups, those using dimerization reaction or photocrosslinking reaction are preferred in terms of excellent orientation and maintaining a liquid crystal state at the time of polarizing layer formation. As a photoreactive group which can cause the above reaction, it is preferable to have an unsaturated bond, especially a double bond, a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), nitrogen Particular preference is given to photoreactive groups having at least one selected from the group consisting of -nitrogen double bonds (N = N bonds) and carbon-oxygen double bonds (C = O bonds).

Examples of the photoreactive group having a C═C bond include vinyl group, polyene group, stilbene group, stilazole group, stilbazolium group, chalcone group and cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having structures such as aromatic sieve bases and aromatic hydrazones. As a photoreactive group which has N = N bond, what has a basic structure, such as an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bis azo group, a formazan group, and azoxybenzene is mentioned. Examples of the photoreactive group having a C═O bond include benzophenone group, coumarin group, anthraquinone group, maleimide group, and the like. These groups may have substituents, 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 reaction is preferable, and a cinnamoyl group and a chalcone group are preferable because a relatively small amount of polarization irradiation required for photoalignment is obtained, and an optical alignment layer excellent in thermal stability and time stability is easily obtained. Do. More specifically, as the polymer having a photoreactive group, one having a cinnamoyl group in which the terminal portion of the polymer side chain becomes a cinnamic acid structure is particularly preferable.

As a solvent of the composition for photo-alignment layer forming, what melt | dissolves a photoorganic oriented material fully is mentioned among what was illustrated as the solvent which the said liquid crystal phase difference layer forming composition contains.

The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photoalignment layer may be appropriately adjusted according to the type of the polymer or monomer having the photoreactive group or the thickness of the photoalignment layer to be prepared. It is preferable to set it as 0.2 mass% at least, and the range of 0.3-10 mass% is especially preferable. In addition, within the range in which the properties of the photoalignment layer are not significantly impaired, the composition for forming the photoalignment layer may include a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer.

As a method of apply | coating the composition for orientation layer formation or the composition for photo-alignment layer formation on a retardation film, application methods and flexes, such as a spin coating method, the extrusion method, the gravure coating method, the die coating method, the bar coating method, and the applicator method, are mentioned. A well-known method, such as a printing method, such as a small method, is employ | adopted.

As a method of forming a photo-alignment layer with the photo-alignment organic layer formed by apply | coating the composition for photo-alignment layer formation on retardation film, the following methods are mentioned, for example.

First, the solvent contained in the coating film is removed by annealing the coating film obtained by applying the composition for forming the photo-alignment layer. Appropriate conditions are employ | adopted for the temperature and time in such an annealing process according to the kind of solvent etc. which are contained in the composition for photo-alignment layer formation.

An orientation regulation force can be provided by irradiating polarization (preferably polarization UV) to the photo-alignment organic layer after annealing treatment. By such polarization irradiation, the alignment layer which has an orientation regulation force in a desired orientation 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 serving as the substrate, and it is preferable to irradiate in the direction of 60 ° or -60 ° substantially to the slow axis of the retardation film. .

The thickness of the alignment layer thus formed is determined so that the total thickness of the circular polarizing plate does not significantly exceed the range described later, but is usually 10 to 1000 nm. The thickness of such an orientation layer can be controlled by the thickness of the coating film formed by apply | coating the composition for orientation layer formation. The thickness of an alignment layer is calculated | required by the measurement of an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

Next, the composition for liquid crystal phase difference layer formation is apply | coated on the formed orientation layer. Examples of the coating method include the same as those exemplified as the coating method of the composition for forming an alignment layer.

Next, a dry film is formed by drying and removing the solvent contained in the coating film for liquid crystal phase difference layer formation formed by apply | coating on an orientation layer. As a drying method, a natural drying method, a ventilation drying method, a heating drying, a vacuum drying method, etc. are mentioned, for example.

Subsequently, light is irradiated to a dry film, the polymerizable liquid crystal compound in a dry film is polymerized, and a liquid crystal phase difference layer is formed. Light irradiated to a dry film is suitably selected from visible light, an ultraviolet light, a laser light, or an active electron beam according to the kind of polymeric liquid crystal compound contained in the dry film, or the kind and quantity of a polymerization initiator. Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and that a device widely used in the field can be used as an apparatus for photopolymerization. Therefore, the kind of polymeric liquid crystal compound and photoinitiator contained in the said liquid crystal retardation layer formation composition are selected so that it may superpose | polymerize by an ultraviolet light.

The thickness of the liquid crystal retardation layer formed in this way is determined so that the total thickness of this circularly polarizing plate may not exceed remarkably the range mentioned later, and is 0.5-5.0 micrometers normally. The thickness of such a liquid crystal retardation layer can be controlled by controlling the thickness of the coating film for forming a liquid crystal retardation layer and the birefringence of the polymerizable liquid crystal compound.

Polarizing Layer Forming Process:

Subsequently, the laminate on which the liquid crystal retardation layer and the retardation film are laminated, preferably on the retardation film side of the laminate on which the liquid crystal retardation layer, the alignment layer and the retardation film are laminated (that is, the surface opposite to the surface on which the liquid crystal retardation layer is provided). A polarizing layer is formed.

First, the composition for polarizing layer formation used for polarizing layer formation is demonstrated. This composition for polarizing layer formation contains a dichroic dye. A dichroic dye means the pigment | dye which has the property which the absorbance in the long axis direction of a molecule | numerator differs from the absorbance in a short axis direction. As long as it has such a property, a dichroic dye may be a dye or a pigment and may be a mixture of several types of compounds.

As said dichroic dye, what has a maximum absorption wavelength ((lambda) MAX) in 300-700 nm is preferable. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes. Among these, azo dyes are preferred. As an azo dye, a monoazo pigment | dye, a bis azo pigment | dye, a tris azo pigment | dye, a tetrakis azo pigment | dye, a stilbenazo pigment | dye, etc. are mentioned, Preferably they are a bis azo pigment | dye and a tris azo pigment | dye.

As an azo dye, the compound (henceforth called "compound (1)") is represented, for example by Formula (1).

A ¹ (-N = NA ² ) _p -N = NA ³ (1)

In formula (1),

A ¹ and A ³ each independently represent a monovalent heterocyclic group which may have a phenyl group which may have a substituent, a naphthyl group which may have a substituent or a substituent. 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 group which may have a substituent. p represents the integer of 1-4. when p is an integer of 2 or more, a plurality of A ² may be the same as or different from each other]

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, benzoimidazole, oxazole and benzoxazole. A group from which two hydrogen atoms have been removed from a heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of such a heterocyclic compound are as described above.

A ¹ and A ³ phenyl group, a naphthyl group and a monovalent heterocyclic group, and A ² p- phenylene group, a naphthalene-1,4-Examples of the substituent group and having a carbon number of 1 to 2. The divalent heterocyclic group optionally in the in An alkyl group of 4; Alkoxy groups having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; C1-C4 alkyl fluoride groups, such as a trifluoromethyl group; Cyano; A nitro group; A halogen atom; A substituted or unsubstituted amino group such as an amino group, a diethylamino group and a pyrrolidino group (a substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two substituted alkyl groups which are mutually bonded to each other and have 2 to 8 carbon atoms); means of the amino group which forms an alkanediyl group. unsubstituted amino group may be mentioned are -NH _2).

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

In 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 definition of a substituted amino group and an unsubstituted amino group is described above. One), a chlorine atom or a trifluoromethyl group.

n1-n4 represent the integer of 0-3 each independently.

When n1 is two or more, some R <^2> may mutually be same or different,

When n2 is two or more, some R <^6> may mutually be same or different,

When n3 is two or more, some R <^9> may mutually be same or different,

when n4 is 2 or more, a plurality of R ¹⁴ may be the same as or different from each other]

The composition for forming a polarizing layer preferably contains a polymerizable liquid crystal compound in addition to a dichroic dye. Although the definition of a polymeric liquid crystal compound is the same as the polymeric liquid crystal compound contained in the composition for liquid crystal retardation layer formation, it is preferable that the polymeric liquid crystal compound contained in the composition for polarizing layer formation shows a smectic-like liquid crystal state, and high-order smectic It is more preferable to show the liquid crystal state of the phase.

Higher order smectic phase is 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 which Smectic B phase, Smectic F phase and Smectic I phase are more preferable. If the smectic liquid crystal phase which a polymerizable liquid crystal compound shows is these higher order smectic phases, since a polarizing layer with higher orientation order can be formed, it is especially preferable. The polarizing film having a high degree of orientation order can obtain Bragg peaks derived from higher order structures such as hexatic phase and crystal phase in X-ray diffraction measurement. The said Bragg peak is a peak derived from the surface periodic structure of molecular orientation, According to the composition for polarizing layer formation of this invention, this polarizing film whose period interval is 3.0-5.0 microseconds can be obtained.

As a polymeric liquid crystal compound, the thing similar to the polymeric liquid crystal compound which the composition for liquid crystal phase difference layer formation contains is mentioned. Preferably, the compound (henceforth called "compound (2)") represented by Formula (2) is mentioned. Compound (2) is preferable because it is easy to show 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 independently represent a cyclohexane-1,4-diyl group which may have a 1,4-phenylene group or a substituent which may have a substituent. Provided that 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 a cyclohexane-1,4-diyl group which may have a substituent may be substituted with -O-, -S-, or -NR-. R is a C1-C6 alkyl group or a phenyl group.

Y ¹ and Y ² are each independently -CH ₂ CH _2- , -CH ₂ O-, -COO-, -OCOO-, single bond, -N = N-, -CR ^a = CR ^b- , -C≡ C- or -CR ^a = N-. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

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

V ¹ and V ² is -CH ₂ that even have a substituent independent of each other represents an alkanediyl group having 1 to 20 carbon atoms of the good, configure the alkanediyl group - is replaced with -O-, -S-, -NH- May be done]

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

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

As a 1, 4- phenylene group which may have a substituent, or the substituent which the said cyclohexane-1, 4- diyl group arbitrarily has, C1-C4 alkyl groups, such as a methyl group, an ethyl group, and a butyl group; Cyano; Halogen atom etc. are mentioned.

Y ¹ of 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 preferably a polymerizable group, and more preferably a photopolymerizable group. A photopolymerizable group means the group which can participate in a polymerization reaction by active radical, acid, etc. which generate | occur | produced from the photoinitiator mentioned later. Use of the polymerizable liquid crystal compound having a photopolymerizable group is also advantageous in that the compound (2) can be polymerized under lower temperature conditions.

In compound (2), although the polymerizable groups of U <^1> and U <^2> may mutually differ, it is preferable that they are the same kind of group. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Especially, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group, and oxetanyl group are preferable, and acryloyloxy group is more preferable.

Examples of the C 1-20 C-candiyl group in the C 1-20 alkanediyl group which may have a substituent represented by V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group and a butane- 1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-di Diary, 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.

Although a cyano group, a halogen atom, etc. are mentioned as a substituent which the C1-C20 alkanediyl group which may have a substituent arbitrarily contains, The said alkanediyl group is preferably unsubstituted, and is unsubstituted and linear alkanediyl group. It is more preferable that is.

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

As compound (2), the compound etc. which are respectively represented by Formula (2-1)-formula (2-23) are mentioned. When the specific example of such a compound (2) has a cyclohexane-1, 4-diyl group, it is preferable that this cyclohexane-1, 4-diyl group is a trans body.

The polymerizable liquid crystal compound contained in the composition for polarizing layer formation may be singly or in combination. When combining, at least 1 sort (s) is preferable.

The mixing ratio in the case of combining two types of polymerizable liquid crystal compounds is 1: 99-50: 50 normally, Preferably it is 5: 95-50: 50, More preferably, it is 10: 90-50: 50.

The polymerization of the composition for forming a polarizing layer obtains a phase transition temperature of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer in advance, and other than the polymerizable liquid crystal compound so that the polymerizable liquid crystal compound is polymerized under the temperature transition temperature. Adjust the ingredients. On the other hand, also when using the mixture of 2 or more types of polymeric liquid crystal compositions for the composition for polarizing layer formation, after performing the phase transition temperature of the mixture of 2 or more types of polymeric liquid crystal compounds, it performs in the same way.

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

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. When the content ratio of the polymerizable liquid crystal compound is in the above range, the orientation of the polymerizable liquid crystal compound tends to be increased. Here, solid content means the total amount of the component except the solvent in the composition for polarizing layer formation.

The polymerizable liquid crystal compound included in the composition for forming a polarizing layer is, for example, Lub et al. Recl. Trav. Chim. It is produced by the 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 which is inert to the polymerization reaction of the polymerizable liquid crystal compound. As a specific example, the composition for liquid crystal phase difference layer formation The same thing as this containing solvent 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, 2-50 mass% of solid content in the composition for polarizing layer formation is preferable.

It is preferable that the composition for polarizing layer formation contains a leveling agent. This leveling agent has a function which adjusts the fluidity | liquidity of the composition for polarizing layer formation, and has a function which makes flat the coating film for polarizing layer formation obtained by apply | coating the composition for polarizing layer formation, Surfactant etc. are mentioned. As a preferable leveling agent, the leveling agent which has a polyacrylate compound as a main component, the leveling agent which has a fluorine atom containing compound as a main component, etc. are mentioned.

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

Leveling agents mainly composed of fluorine atom-containing compounds include "mega park R-08", copper "R-30", copper "R-90", copper "F-410", copper "F-411", copper "F -443 ", East" F-445 ", East" F-470 ", East" F-471 ", East" F-477 ", East" F-479 ", East" F-482 "and East" F- 483 "[DIC Corporation]; "Suplon S-381", "S-382", "S-383", "S-393", "SC-101", "SC-105", "KH-40" and " SA-100 "[AGC Seiko Chemical Co., Ltd.]; "E1830", "E5844" [Daikin Fine Chemicals Gensho Co., Ltd.]; "E-top EF301", the "EF303", the "EF351", and the "EF352" [Missubishi Material Alden Shigase Co., Ltd.] etc. are mentioned.

When the composition for polarizing layer formation contains a leveling agent, the content is 0.3 mass part or more and 5 mass parts or less normally with respect to 100 mass parts of polymeric liquid crystal compounds, Preferably they are 0.5 mass part or more and 3 mass parts or less. When content of a leveling agent exists in the said range, it is easy to horizontally align a polymeric liquid crystal compound, and there exists a tendency for the polarizing film obtained to become smoother. When content of the leveling agent with respect to a polymeric liquid crystal compound exceeds the said range, there exists a tendency for a nonuniformity to arise easily in the polarizing layer obtained. In addition, the said composition for polarizing layer formation may contain two or more types of leveling agents.

It is preferable that the composition for polarizing layer formation contains a polymerization initiator. The polymerization initiator is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound. As a polymerization initiator, a photoinitiator is preferable at the point which can start a polymerization reaction under low temperature conditions. Specifically, a compound which generates an active radical or an acid by the action of light is used as the photopolymerization initiator. Among these photoinitiators, it is more preferable to generate active radicals by the action of light.

As a polymerization initiator, the same thing as the polymerization initiator which the composition for liquid crystal retardation layer formation contains is mentioned.

When the composition for forming a polarizing layer contains a polymerization initiator, the content thereof may be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound included in the composition for forming a polarizing layer, but the total of 100 parts by mass of the polymerizable liquid crystal compound Content of the polymerization initiator with respect to is 0.1-30 mass parts normally, Preferably it is 0.5-15 mass parts, More preferably, it is 0.5-8 mass parts. When content of a polymeric initiator is in this range, since it can superpose | polymerize without disturbing the orientation of a polymeric liquid crystal compound, it is preferable.

When the composition for polarizing layer formation contains a photoinitiator, the composition for polarizing layer formation may contain a photosensitizer. As a photosensitizer, For example, xanthone compounds, such as xanthone and thioxanthone (for example, 2, 4- diethyl thioxanthone, 2-isopropyl thioxanthone, etc.); Anthracene compounds such as anthracene and an alkoxy group-containing anthracene (eg, dibutoxyanthracene, etc.); Phenothiazine, rubrene, and the like.

When the composition for polarizing layer formation contains a photoinitiator and a photosensitizer, the polymerization reaction of the polymeric liquid crystal compound contained in the composition for polarizing layer formation is promoted more. Although content of such a photosensitizer can be suitably adjusted according to the kind and quantity of the photoinitiator and polymeric liquid crystal compound used together, it is 0.1-30 mass parts normally with respect to 100 mass parts of total polymerizable liquid crystal compounds, Preferably Is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts.

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

Examples of the polymerization inhibitor include radicals such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butylcatechol, etc.), pyrogallol, and 2,2,6,6-tetramethyl-1-piperidinyloxy radicals. Supplements; Thiophenols; (beta) -naphthylamine, (beta) -naphthol, etc. are mentioned.

When the composition for forming a polarizing layer contains a polymerization inhibitor, the content thereof may be appropriately adjusted depending on the kind and amount of the polymerizable liquid crystal compound used in combination, the amount of the photosensitizer used, and the like, but 100 parts by mass of the polymerizable liquid crystal compound. It is 0.1-30 mass parts normally with respect to, Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. When content of a polymerization inhibitor is in the said range, since it can superpose | polymerize without disturbing the orientation of the polymeric liquid crystal compound contained in the composition for polarizing layer formation, it is preferable.

Although content of the dichroic dye in the composition for polarizing layer formation can be adjusted suitably according to the kind of dichroic dye, etc., it is 0.1 mass part or more and 50 mass parts or less normally with respect to a total of 100 mass parts of a polymeric liquid crystal compound, Preferably they are 0.1 mass part or more and 20 mass parts or less, More preferably, they are 0.1 mass part or more and 15 mass parts or less. If content of a dichroic dye is in this range, since the said polymeric liquid crystal compound can be polymerized without disturbing the orientation of a polymeric liquid crystal compound, it is preferable.

Next, the method of forming a polarizing layer on retardation film, Preferably, an orientation layer using the composition for polarizing layer formation is demonstrated.

First, the composition for polarizing layer formation is apply | coated on retardation film, and the coating film for polarizing layer formation is formed. In this case, it is preferable to provide an alignment layer in advance on the surface on which the polarizing layer on the retardation film is to be formed. As a formation method of such an orientation layer, the method similar to the formation method of the orientation layer demonstrated by description of liquid crystal phase difference layer formation is mentioned. As for the alignment layer formed between a polarizing layer and retardation film, a photo-alignment layer is preferable like the alignment layer provided between a liquid crystal retardation layer and a retardation film. Although the thickness of the orientation layer provided between a polarizing layer and retardation film is determined so that the total thickness of this circularly polarizing plate may not significantly exceed the range mentioned later, it is 10-1000 nm normally. In this invention, it is necessary to irradiate polarization irradiated horizontally or vertically with respect to the slow axis of the retardation film which is a board | substrate, and it is preferable to irradiate in the direction of 15 degrees or -15 degrees substantially with respect to the slow axis of a retardation film.

As a method of apply | coating the composition for polarizing layer formation on an orientation layer, the method similar to what was illustrated as a coating method of the composition for orientation layer formation is mentioned.

Next, a dry film is formed by drying and removing a solvent on the conditions which the polymerizable liquid crystal compound contained in the coating film for polarizing layer formation does not superpose | polymerize. As a drying method, a natural drying method, a ventilation drying method, a heating drying, a vacuum drying method, etc. are mentioned, for example. Next, after making the liquid crystal state of the polymeric liquid crystal composition contained in a dry film into a nematic phase, it is preferable to transfer this nematic phase to a smectic phase. Thus, in order to form a smectic phase via a nematic phase, the polymeric liquid crystal compound contained in a dry film, for example, is heated above the temperature which phase-transfers into the liquid crystal state of a nematic phase, and then the said polymeric smectic liquid crystal compound is a smectic phase The method of cooling to the temperature which shows a liquid crystal state is employ | adopted.

When the polymeric liquid crystal compound in a dry film is made into a smectic liquid crystal state or a smectic liquid crystal state via a nematic liquid crystal state, the conditions which control a liquid crystal state by measuring the phase transition temperature of the polymeric liquid crystal compound (heating conditions ) Can be easily obtained.

Next, the superposition | polymerization process of a polymeric liquid crystal compound is demonstrated. Here, after containing a photoinitiator in the composition for polarizing layer formation, making the liquid crystal state of the polymeric liquid crystal compound in a dry film into a smectic phase, the method of photopolymerizing the said polymeric liquid crystal compound with this smectic phase liquid crystal state maintained This will be described in detail. In photopolymerization, the light irradiated to a dry film is suitably according to the kind of photoinitiator contained in the dry film, the kind of polymeric liquid crystal compound (especially the kind of polymeric group which a polymeric liquid crystal compound has), and its quantity. It can carry out with the light selected from the group which consists of visible light, an ultraviolet light, and a laser beam, or an active electron beam. Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and that a device widely used in the field can be used as an apparatus for photopolymerization. Therefore, it is preferable to select the kind of polymeric liquid crystal compound and photoinitiator contained in the said composition for polarizing layer formation so that photopolymerization may be carried out by ultraviolet light. In addition, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a dry film with suitable cooling means with ultraviolet light irradiation. When employ | adopting such a cooling means can superpose | polymerize a polymeric liquid crystal compound at low temperature, there exists also an advantage that a polarizing layer can be formed suitably even if the thing with comparatively low heat resistance is used for retardation film. On the other hand, when photopolymerization, the patterned polarizing layer can also be obtained by masking, image development, or the like.

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 smectic phase as already exemplified, and a polarizing layer is formed. The polarizing layer obtained by superposing | polymerizing with a polymeric liquid crystal compound maintaining the liquid crystal state of a smectic phase is accompanied with the action of the said dichroic dye, and maintains the conventional host guest type polarizing layer, ie, the nematic liquid crystal state. There exists an advantage that polarization performance is much higher compared with the polarizing layer obtained by superposing | polymerizing a polymeric liquid crystal compound etc. In addition, there is an advantage that the strength is excellent as compared with the application of only a dichroic dye or a lyotropic liquid crystal.

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

As mentioned above, although this circular polarizing plate can be manufactured by this manufacturing method demonstrated, in this manufacturing method demonstrated here, the order of a liquid crystal phase difference layer forming process and a polarizing layer forming process may be reversed. Although this manufacturing method demonstrated so far is based on the method of performing a preparation process, a liquid crystal phase difference layer formation process, and a polarizing layer formation process in this order, a preparation process, a polarizing layer formation process, and a liquid crystal phase difference layer formation process are performed in this order. Even if it did, this circular polarizing plate can be obtained. The conditions and the like of each step in this case are as described above.

As mentioned above, although the outline | summary of the manufacturing method of the circular polarizing plate in this invention was demonstrated, when manufacturing this circular polarizing plate commercially, the method which can manufacture this polarizing plate continuously is calculated | required. As a suitable example of such a continuous manufacturing method, the method by a roll to roll type (henceforth "continuous this manufacturing method") is mentioned.

As one embodiment of the continuous production process, for example

(i) preparing the roll in which the retardation film is wound around the core;

(ii) sending the retardation film continuously from the roll;

(iii) applying the composition for forming an alignment layer on the retardation film to continuously form a first alignment layer on the retardation film;

(iv) applying the composition for liquid crystal retardation layer formation on the first alignment layer formed in (iii) to continuously form a liquid crystal retardation layer on the first alignment layer;

(v) applying a composition for forming an alignment layer to a surface opposite to a surface on which the liquid crystal retardation layer of the retardation film is formed, and continuously forming a second alignment layer on the retardation film;

(vi) process of apply | coating the composition for polarizing layer formation on the 2nd orientation layer formed in (v), forming a polarizing layer continuously on a 2nd orientation layer, and obtaining this circularly polarizing plate;

(vii) The process of winding this circularly obtained polarizing plate obtained continuously in a 2nd core and obtaining a 2nd roll.

Hereinafter, although this continuous manufacturing method is demonstrated with reference to FIG. 2, detailed description is abbreviate | omitted about formation of the orientation layer corresponding to (iii) and (v) in the same figure.

First, the roll 210 in which the retardation film is wound in (i) is prepared.

(ii) continuously disengages the retardation film 110 from the first roll 210, and forms a first alignment layer (not shown) on one side of the retardation film in (iii) to align it on one side. The layered first laminate 120 can be obtained.

Subsequently, in (iv), the liquid crystal phase difference layer is formed on the 1st orientation layer formed in (iii). Specifically, the composition for liquid crystal phase difference layer formation is apply | coated using the coating apparatus 211A, and the coating film for liquid crystal phase difference layer formation is formed on the said orientation layer. The formed coating film passes through the drying apparatus 212A together with the retardation film to remove the solvent and the like. Moreover, light irradiation is performed by the light irradiation apparatus 213A, and the 2nd laminated body 140 in which the retardation layer and the liquid crystal phase difference layer were formed can be obtained.

Next, in (v), the 3rd laminated body in which the 2nd alignment layer was formed (not shown) on the surface opposite to the surface in which the liquid crystal phase difference layer of the 2nd laminated body 140 was provided, and the 2nd alignment layer was formed ( 150).

The polarizing layer is formed in (vi) on the 2nd orientation layer of the 3rd laminated body 150 obtained by (v). Specifically, the composition for polarizing layer formation is apply | coated using the coating device 211B, and the coating film for polarizing layer formation is formed on a 2nd orientation layer. The formed coating film passes through the drying apparatus 212B together with the retardation film to remove the solvent and the like. Moreover, light irradiation is performed by the light irradiation apparatus 213B, and this circularly polarizing plate 100 provided with the liquid crystal retardation layer, the retardation layer, and the polarizing layer in this order can be obtained.

The obtained circular polarizing plate 100 can be wound around a second core to obtain a second roll 220.

The total thickness of the circular polarizing plate is suitable for a display device requiring thinning. Such total thickness is normally 20-200 micrometers, and it is preferable if it is 20-100 micrometers.

The circular polarizing plate 100 thus obtained is also used as a member of a display device cut to a desired dimension according to the use of the circular 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 circular polarizing plate 100 is shown. In the circular polarizing plate 100, it is preferable that the retardation layer 1 functions as a half wave plate, and the liquid crystal retardation layer functions as a quarter wave plate. The smaller angle AG2 and the phase difference layer 1 among the angles formed by the slow axis of the liquid crystal phase difference layer 2 (1/4 wave plate) with respect to the slow axis of the phase difference layer 1 (1/2 wave plate). The smaller angle AG3 among the angles formed by the absorption axis or transmission axis of the polarizing layer 3 with respect to the slow axis of the (1/2 wave plate) is preferably the following combination, respectively.

Combination with AG2 substantially 60 ° and AG3 substantially -15 °

Combination where AG2 is substantially 90 ° and AG3 is substantially -22.5 °

The circular polarizing plate can be used for various display devices. The 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. As the display device, for example, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (for example, an electric 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 (e.g., display device with a grating light valve (GLV) display device, digital micromirror device (DMD)), and piezoelectric And a ceramic display, etc. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, a projection liquid crystal display device, and the like. The display apparatus which displays a two-dimensional image may be sufficient, and the stereoscopic display apparatus which displays a three-dimensional image may be sufficient. As can be effectively used in the luminescent (EL) display device or an inorganic electroluminescence (EL) display device of the display device.

As an example of the display device provided with the circular polarizing plate, an EL display device (hereinafter referred to as "this EL display device" in some cases) will be described with reference to FIG. 3. In the EL display device 30, an organic functional layer 36 and a cathode electrode 37 serving as light emitting sources are stacked on a substrate 33 on which a pixel electrode 35 is formed. The circularly polarizing plate 100 is disposed opposite to the organic functional layer 36 with the substrate 33 therebetween. The organic functional layer 36 emits light 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 as a light emitting source is composed of an electron transporting layer, a light emitting layer, a hole transporting layer, and the like. Light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, and the circular polarizing plate 100. Although the organic electroluminescence display which has the organic functional layer 36 is demonstrated, you may apply to the inorganic electroluminescence display which has an inorganic functional layer.

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

Subsequently, the circularly polarizing plate 100 is provided on the surface opposite to the surface on which the thin film transistor 40 of the substrate 33 is provided. In that case, the phase difference layer 2 of the circular polarizing plate 100 is disposed so as to be on the substrate 33 side.

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

Examples of the substrate 33 include ceramic substrates such as sapphire glass substrate, quartz glass substrate, soda glass substrate, and alumina; Metal substrates such as copper; Plastic substrates; Although not shown, a thermally conductive film may be formed on the substrate 33. Examples of the thermal conductive film include diamond thin films (DLC and the like). When the pixel electrode 35 is a reflective type, light is emitted in a direction opposite to the substrate 33. Therefore, not only a transparent material but also a non-transmissive material, such as stainless steel, can be used. The substrate may be formed singly or may be formed as a laminated substrate by joining a plurality of substrates with an adhesive. In addition, these board | substrates are not limited to what is plate-shaped, A film may be sufficient.

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

Wiring electrodes of the thin film transistor 40 are provided on the substrate 33. The wiring electrode has a low resistance and has a function of electrically connecting with the pixel electrode 35 to suppress the resistance value. Generally, the wiring electrode has Al, Al and transition metals (except Ti), Ti or nitride. Any one or two or more kinds of titanium (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 evaporating inorganic materials such as silicon oxide and silicon nitride such as SiO ₂ , a silicon oxide layer formed of SOG (spin on glass), photoresist, polyimide, acrylic resin, and the like. Any one may be used as long as it has insulation such as a coating film of a resin-based material.

The ribs 41 are formed on the interlayer insulating film 34. The rib 41 is disposed at the periphery (between adjacent pixels) of the pixel electrode 35. Examples of the material of the ribs 41 include acrylic resins and polyimide resins. The thickness of the ribs 41 is preferably 1.0 µm or more and 3.5 µm, and more preferably 1.5 µm or more and 2.5 µm or less.

Next, an EL element including the pixel electrode 35 serving as a transparent electrode, the organic functional layer 36 serving as a light emitting source, and the cathode electrode 37 will be described. The organic functional layer 36 has at least one hole transport layer and a light emitting layer, respectively, and has an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer in sequence.

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 , but ITO and IZO are particularly preferable. The thickness of the pixel electrode 35 should just have a thickness more than a fixed enough to perform hole injection, and it is preferable to set it as about 10-500 nm.

The pixel electrode 35 can be formed by vapor deposition (preferably sputtering). It does not restrict | limit especially as a sputter gas, What is necessary is just to use inert gas, such as Ar, He, Ne, Kr, and Xe, or mixed gas.

As the constituent material of the cathode electrode 37, 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, it is preferable to use a two- or three-component alloy system selected from the illustrated 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 -20 at%), etc. are preferable.

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

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

The thickness of the light emitting layer, the thickness obtained by adding the hole injection layer and the hole transporting layer, and the thickness of the electron injection transporting layer are not particularly limited, and vary depending on the formation method, but are preferably about 5 to 100 nm. Various organic compounds can be used for the hole injection layer and the hole transport layer. The vacuum evaporation method can be used in that a homogeneous thin film can be formed for formation of a hole injection transport layer, a light emitting layer, and an electron injection transport layer.

As the organic functional layer 36 as a light emitting source, it is possible to use light emission from the singlet excitons (fluorescence), to use light emission from the triplet excitons (phosphorescence), to use light emission from the singlet excitons (fluorescence) and to triplet. Including those utilizing luminescence (phosphorescence) from excitons, those formed by organic matter, those formed by organic matter and those formed by inorganic matter, materials of polymers, materials of low molecules, materials of polymers and materials of low molecules It may be used to include. However, the present invention is not limited to this, and the organic functional layer 36 using various known materials for EL elements can be used for the present 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 weak in humidity. Moisture is absorbed by the desiccant 38 to prevent deterioration of the organic functional layer 36.

4 is a schematic view showing a cross-sectional structure of another embodiment of the EL display device 30. This EL display device 30 has a sealing structure using the thin film sealing film 42, and can emit light from the opposite side of the array substrate.

As the thin film sealing film 42, it is preferable to use a DLC film in which DLC (diamond like carbon) is deposited on a film of an electrolytic capacitor. DLC membrane has the characteristic that the water permeability is very bad, and high moisture-proof performance. A DLC film or the like may also be formed by directly depositing the surface of the cathode electrode 37. In addition, a thin film sealing film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

The present EL display device with the circular polarizing plate 100 has the excellent anti-reflection performance because the circular polarizing plate 100 has excellent anti-reflection performance, so that the black display is not colored when observed at a spot, and the characteristics as the display device are not. It becomes excellent.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. In the examples, "%" and "parts" are% by mass and parts by mass unless otherwise specified.

Example 1

[Preparation of the composition (1) for liquid crystal retardation layer formation]

The composition (1) for liquid crystal retardation layer formation was obtained by mixing the following components and stirring at 80 degreeC for 1 hour.

Polymerizable liquid crystal compounds; 100 parts of LC-242 BASF company make

Polymerization initiator; 3-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (irgacure 907; manufactured by Chiba Specialty Chemicals Co., Ltd.)

solvent; 250 parts cyclopentanone

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

The following component was mixed and stirred at 80 degreeC for 1 hour, and the composition (1) for optical orientation layer formation was obtained.

Mineral organic oriented materials; Part 5

solvent; 95 cyclopentanones

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

The following component was mixed and stirred at 80 degreeC for 1 hour, and the composition for polarizing layer formation containing a dichroic dye was obtained.

Polymerizable liquid crystal compounds; 75 parts of compounds (2-6)

25 parts of compound (2-7)

Dichroic dyes; 2.5 parts of dichroic dyes (1-1-1)

2.5 parts of dichroic dyes (1-1-2)

2.5 parts of dichroic dyes (1-3-1)

Polymerization initiator; 6 parts of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (irgacure 369; Chiba Specialty Chemicals Co., Ltd.)

Leveling agents; 1.5 parts of polyacrylate compounds (BYK-361N; manufactured by BYK-Chemie)

solvent; 250 parts cyclopentanone

[Measurement of Phase Transition Temperature]

The composition (1) for polarizing layer formation was apply | coated and dried on glass, the sample was produced, and the phase transition temperature was confirmed by the observation of the texture by a polarizing microscope. After raising the temperature to 140 degreeC, the dry film obtained from the composition (1) for polarizing layer formation phase-transforms into a nematic phase at 108 degreeC, phase-transforms into a smectic A phase at 101 degreeC, and is 76 degreeC. Phase changed to Smectic B.

[Manufacture of this circularly polarizing plate]

1. Formation of the second alignment layer

As the retardation film, a half wave plate (zeonoa film, Nippon Xeon Co., Ltd., in-plane retardation value Ro: 270 nm) which is a uniaxially stretched film of cyclic olefin resin was used.

The composition (1) for photo-alignment layer formation was apply | coated by the bar coat method on the said retardation film, and it heat-dried for 1 minute in 60 degreeC drying oven. Polarization UV was irradiated to the obtained photo-alignment organic layer, and the photo-alignment layer was formed. Polarized UV was irradiated under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). In addition, the polarization direction of polarization UV was performed so that it might become 15 degrees with respect to the slow axis of the retardation layer which consists of retardation films.

2. Formation of Polarizing Layer

The composition (1) for polarizing layer formation was apply | coated by the bar coat method on the 2nd orientation layer, and it heated and dried in 120 degreeC drying oven for 1 minute, cooled to room temperature, and obtained the dry film. Using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), ultraviolet rays having an exposure dose of 1200 mJ / cm 2 (365 nm standard) were irradiated to the obtained dry film to form a polarizing layer, thereby forming a polarizing layer. Obtained retardation film (1) was obtained. It was 1.9 micrometers when the thickness of the polarizing layer at this time was measured with the laser microscope (OLS3000 by Olympus Corporation).

3. Formation of the first alignment layer

The composition for photo-alignment layer formation (1) was apply | coated by the bar coat method on the surface opposite to the polarizing layer of the retardation film (1) which has the obtained polarizing layer, and it heat-dried for 1 minute in 60 degreeC drying oven. . Thereafter, polarization UV was irradiated to the obtained photoalignment organic layer to form a photoalignment layer. Polarized UV was irradiated under the same conditions as the second alignment layer. The polarization direction of polarization UV was performed so that it might become 60 degrees (at this time, the absorption axis of a polarizing film is -15 degrees) with respect to the slow axis of the retardation layer which consists of retardation films.

4. Formation of Retardation Layer

On the 1st orientation layer, the composition (1) for liquid crystal retardation layer formation was apply | coated by the bar coat method, and it heat-dried in 50 degreeC drying oven for 1 minute, cooled to room temperature, and obtained the dry film. Using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), ultraviolet rays having an exposure dose of 500 mJ / cm 2 (365 nm standard) were irradiated onto the obtained dry film to form a liquid crystal phase difference layer. The polarizing plate 1 was obtained. It was 1.0 micrometer when the thickness of the retardation layer at this time was measured by the laser microscope (Olympus Co., Ltd. OLS3000). It was 46 micrometers when the total thickness of this circular polarizing plate 1 was measured with the contact film thickness meter.

[Evaluation of this Circularly Polarizing Plate 1]

1. X-ray diffraction measurement

The X-ray diffraction measurement was performed about the polarizing layer of this circularly polarizing plate 1 using the X-ray-diffraction apparatus X 'Pert PRO MPD (made by Specitors Co., Ltd.). Using the Cu as a target, the X-ray generated under the condition of 40 mA of X-ray tube current and 45 kV of X-ray tube voltage was obtained by rubbing direction (preliminarily, the rubbing direction of the alignment layer under the polarizing layer) through the fixed divergence slit 1/2 °. And a scanning diffraction peak (FWHM) = approximately 0.29 ° around 2θ = 20.12 °, and measured by scanning in 2θ = 0.01671 ° steps in the scan range 2θ = 4.0 to 40.0 °. Peak). Moreover, the equivalent result was obtained also in incidence from the orientation perpendicular direction. The order period (d) obtained from the peak position was about 4.4 Hz, and it was found that a structure reflecting the higher order smectic phase was formed.

2. Measurement of reflectance

In order to confirm the usefulness of this circular polarizing plate 1, the reflectance was measured as follows. The liquid crystal phase difference layer side and the reflecting plate (mirror surface aluminum plate) of the produced this circularly-polarizing plate 1 were bonded together using the adhesive, and the measurement sample was prepared.

Using a spectrophotometer (UV-3150 manufactured by Shimadzu Seisakusho Co., Ltd.), light having a wavelength in the range of 400 to 700 nm was incident from the normal direction 12 ° to the measurement sample in 2 nm steps to reflect the reflected light. Measured. When reflectance was measured at 100% when only the reflecting plate was placed without measuring the circularly polarizing plate 1, the light in the range of 400 to 700 nm was 1 to 10% at any wavelength, which was sufficient for the entire visible light. Antireflection characteristics could be obtained.

Example 2

In the same manner as in Example 1, an optical alignment layer (the polarization direction of polarized UV is 60 ° with respect to the slow axis of the retardation film) is formed on one surface of the retardation film, and a liquid crystal retardation layer is formed on the optical alignment layer. Formed. Then, on the surface opposite to the liquid crystal retardation layer of the retardation film having a liquid crystal retardation layer, an optical alignment layer (polarization direction of the polarization UV is 15 ° to the slow axis of the retardation film) is formed, and on the optical alignment layer The polarizing layer was further formed and the circular polarizing plate 2 was produced.

It was 46 micrometers when the total thickness of this circular polarizing plate 2 was measured with the contact film thickness meter.

The circular polarizing plate 2 was bonded to the reflecting plate using an adhesive in the same manner as in Example 1, and the reflectance thereof was measured. As a result, light in the range of 400 to 700 nm was 1 to 10% at any wavelength, which was sufficient for the entire visible light. Antireflection characteristics could be obtained.

Comparative Example 1

As the retardation film, a retardation film was prepared in the same manner as in Example 1 using a quarter wave plate (Zenooa film, Nippon Xeon Co., Ltd., in-plane retardation value Ro: 138 nm) which is a uniaxially stretched film of cyclic olefin resin. An optical orientation layer (the polarization direction of polarization UV was 45 degrees with respect to the slow axis of a retardation film) was formed in one surface of the, and the polarization layer was further formed on the optical orientation layer, and the circular polarizing plate 3 was produced.

When the circularly polarizing plate 3 was bonded in the same manner as in Example 1 and bonded to the reflecting plate using an adhesive, the reflectance was measured. As a result, light of 500 to 600 nm was good reflectance of about 1 to 10%. However, the light of 400 to 500 nm and 600 to 700 nm had a reflectance of 10% or more, and the reflected light was bluish purple, and a sufficient antireflection function could not be obtained.

Reference Example 1

As a polarizing plate, an iodine-PVA polarizing plate (105 micrometers of Sumitoran Sumitomo Chemical Co., Ltd. thickness) was cut out into small pieces of 100x100 mm so that an absorption axis might be 0 degrees, and the 1/2 wavelength plate used in Example 1 was used Cut the film into 100 × 100 mm small pieces so that the slow axis is 15 °, and cut the quarter wave plate used in Comparative Example 1 into small pieces of 100 × 100 mm so that the slow axis is 75 °. The circularly-polarizing plate 4 was produced by laminating single sheets using an acrylic pressure-sensitive adhesive (film thickness of 25 µm) so as to be a polarizing plate +1/2 wavelength plate +1/4 wavelength plate.

When the circularly polarizing plate 4 was bonded to the reflecting plate by using an adhesive in the same manner as in Example 1, the reflectance was measured, and the light in the range of 400 to 700 nm was 1-10% at any wavelength, and sufficient reflection was made over the entire visible light. Preventive properties could be obtained. However, when the total thickness was measured by the contact film thickness meter, it was 240 micrometers, about 5 times the thickness of this circular polarizing plate 1.

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

1: retardation layer 2: liquid crystal retardation layer
2A: alignment layer 3: polarizing layer
3A: alignment layer 100: present circularly polarizing plate
110: retardation film 120: first laminate
140: second laminate 150: third laminate
210: first roll 210A: core
220: second roll 220A: core
211A and 211B: coating device 212A and 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 of 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 in which the polarizing layer formed from the composition for polarizing layer formation containing a dichroic dye is provided in this order. The circularly polarizing plate of claim 1, wherein the composition for forming a polarizing layer further comprises a polymerizable liquid crystal compound. The circularly polarizing plate according to claim 2, wherein the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer is a compound exhibiting a smectic liquid crystal state. The circularly polarizing plate according to any one of claims 1 to 3, 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 any one of claims 1 to 4, wherein the polarizing layer can obtain a Bragg peak in X-ray diffraction measurement. The first alignment layer according to any one of claims 1 to 5, wherein a first alignment layer is provided between the liquid crystal retardation layer and the retardation layer.
The circularly polarizing plate is further provided with a second alignment layer between the retardation layer and the polarizing layer. The circularly polarizing plate of Claim 6 in which a liquid crystal phase difference layer is formed by apply | coating the composition for liquid crystal phase difference layer formation containing a polymeric liquid crystal compound to a 1st orientation layer. The circularly polarizing plate of Claim 6 or 7 in which a polarizing layer is formed by apply | coating the composition for polarizing layer formation containing a dichroic dye to a 2nd orientation layer. The circularly polarizing plate according to any one of claims 6 to 8, wherein the first alignment layer or the second alignment layer or both are formed of a composition for forming an alignment layer containing a photoorganic alignment material. The manufacturing method of the circularly polarizing plate which has the following preparation processes, a liquid crystal phase difference layer formation process, and a polarizing layer formation process.
Preparation step: preparing a retardation film formed by stretching a polymer film;
Liquid crystal retardation layer forming process: The process of apply | coating the composition for liquid crystal retardation layer containing a polymeric liquid crystal compound to one surface of the said retardation film, and forming a liquid crystal retardation layer with the coating film for liquid crystal retardation layer formation apply | coated;
Polarizing layer formation process: The process of apply | coating the composition for polarizing layer formation containing a dichroic dye to the other surface of the said retardation film, and forming a polarizing layer with the coating film for polarizing layer formation apply | coated. The display apparatus provided with the circularly-polarizing plate of any one of Claims 1-9, and a display element. The display device according to claim 11, comprising a liquid crystal cell, an organic EL element, or a touch panel as a display element.

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