KR102458585B1 - Circular polarizing plate and display device - Google Patents

Abstract

[Problem] To provide a thin and broadband circularly polarizing plate and a display device provided with the circularly polarizing plate.
[Solutions] Having a substrate, a retardation layer, and a polarizing layer, the birefringence Δn(λ) of the retardation layer with respect to light having a wavelength of λnm satisfies Equations (1) and (2), and the retardation layer and the polarizing layer Circularly polarizing plate, characterized in that it is a coating layer together, the sum of the thickness of the retardation layer and the polarizing layer is 10 µm or less, and the polarizing layer contains a dichroic dye.
Δn(450)/Δn(550)≤1.00 (1)
1.00≤Δn(650)/Δn(550) (2)

Description

Circular polarizer and display device {CIRCULAR POLARIZING PLATE AND DISPLAY DEVICE}

The present invention relates to a circularly polarizing plate and a display device.

A liquid crystal display device comprising a polarizing film made of polyvinyl alcohol dyed with iodine and a broadband circularly polarizing plate in which a 1/2 wave plate and a 1/4 wave plate are laminated is known. In such a broadband circular polarizer, the angle between the slow axis of the half-wave plate and the absorption axis of the polarizing film and the angle between the slow axis of the quarter-wave plate and the absorption axis of the polarizing film are respectively displaced by 15° or 75°, Since it is necessary to laminate, it is difficult to produce the circularly polarizing plate by roll-to-roll bonding. On the other hand, thickness reduction of a display device is also strongly calculated|required, Therefore, thickness reduction of a circularly polarizing plate is also calculated|required.

Patent Document 1 describes a circularly polarizing plate having a thickness of 130 to 370 µm in which a reverse wavelength dispersibility film and a polarizer obtained by coating a dichroic dye are laminated on a retardation layer. Patent Document 2 describes a circularly polarizing plate having a thickness of 36 to 205 µm in which a polarizer containing a substance of thermotropic liquid crystallinity or lyotropic liquid crystallinity is laminated on a retardation layer.

(Patent Document 1) Patent Document 1: Japanese Patent Laid-Open No. 2006-337892

(Patent Document 2) Patent Document 2: Japanese Patent Laid-Open No. 2009-251288

However, since the circularly polarizing plate described in Patent Document 1 is laminated with two films through an adhesive or an adhesive, it was not sufficiently satisfactory in terms of the simplicity of the manufacturing process and the thickness of the circularly polarizing plate. In the circularly polarizing plate described in Patent Document 2, since the retardation layer showed constant wavelength dispersion, the performance as a broadband circularly polarizing plate was insufficient.

The present invention includes the following inventions.

[1] having a substrate, a retardation layer and a polarizing layer, and the birefringence Δn(λ) of the retardation layer with respect to light having a wavelength of λnm satisfies Equations (1) and (2), and the retardation layer and the polarizing layer are together A coating layer, wherein the sum of the thicknesses of the retardation layer and the polarizing layer is 10 µm or less, and the polarizing layer contains a dichroic dye.

Δn(450)/Δn(550)≤1.00 (1)

1.00≤Δn(650)/Δn(550) (2)

[2] The circularly polarizing plate according to [1], wherein the retardation layer is formed by polymerizing one or more polymerizable liquid crystals.

[3] The circularly polarizing plate according to [1] or [2], wherein the polarizing layer is formed by polymerizing one or more polymerizable liquid crystals.

[4] The circularly polarizing plate according to [2] or [3], wherein the polymerizable liquid crystal is polymerized by irradiation with light.

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

[6] The circularly polarizing plate according to any one of [1] to [5], wherein the retardation layer and the polarizing layer each have a thickness of 5 µm or less.

[7] The circularly polarizing plate according to any one of [1] to [6], wherein a retardation layer, a polarizing layer, or both are formed on an alignment film.

[8] The circularly polarizing plate according to [7], wherein the alignment film is an alignment film to which an alignment regulating force is generated by irradiation with light.

[9] The circularly polarizing plate according to [7] or [8], wherein the thickness of the alignment film is 500 nm or less.

[10] The circularly polarizing plate according to any one of [1] to [9], wherein a retardation layer is formed on a substrate with or without an alignment film, and a polarizing layer is formed on the retardation layer through or without an alignment film. .

[11] The circularly polarizing plate according to any one of [1] to [9], wherein a polarizing layer is formed on a substrate with or without an alignment film, and a retardation layer is formed on the polarizing layer through or without an alignment film. .

[12] The circularly polarizing plate according to [10] or [11], having a protective layer between the polarizing layer and the retardation layer.

[13] In any one of [1] to [9] in which a polarizing layer is formed on one side of the substrate with or without an alignment film, and a retardation layer is formed on the other side of the substrate through or without an alignment film Circularly polarizing plate described.

[14] The circularly polarizing plate according to any one of [1] to [13], further comprising a pressure-sensitive adhesive layer on the surface of the retardation layer or the polarizing layer.

[15] The circularly polarizing plate according to [14], which has a base material, a first alignment film, a polarizing layer, a second alignment film, a retardation layer, and an adhesive layer in this order.

[16] The peel strength (F1) between the substrate and the first alignment layer is the peel strength between the first alignment layer and the polarizing layer (F2), the peel strength between the second alignment layer and the retardation layer (F3), and the retardation layer and the pressure-sensitive adhesive layer The circularly polarizing plate according to [15], which is lower than the peel strength (F4) of

[17] A display device comprising the circularly polarizing plate according to any one of [1] to [16] and a display element.

[18] A display device having a circularly polarizing film, wherein the circularly polarizing film from which the substrate has been removed from the circularly polarizing plate according to any one of [14] to [16] is bonded to the display surface of the display element via an adhesive layer of the circularly polarizing film .

[19] The display device according to [18], wherein the thickness of the circularly polarizing film is 5 µm or more and 15 µm or less.

[20] The display device according to any one of [17] to [19], wherein the display element is a liquid crystal cell, an organic electroluminescent element, or a touch panel.

[21] A display device having a circularly polarizing film in which the circularly polarizing plate according to any one of [14] to [16] is bonded to the display surface of the display element through the pressure-sensitive adhesive layer of the circularly polarizing plate, and the substrate is removed from the circularly polarizing plate manufacturing method.

ADVANTAGE OF THE INVENTION According to this invention, the circularly polarizing plate of a thin and wide band, and the display apparatus provided with this circularly polarizing plate can be provided.

1 is a schematic cross-sectional view of a circularly polarizing plate of the present invention.
2 is a schematic diagram of a liquid crystal display device including a circularly polarizing plate of the present invention.
3 is a schematic diagram of an organic EL display device including the circularly polarizing plate of the present invention.

The substrate is usually a transparent substrate. On the other hand, when the base material of the circularly polarizing plate of the present invention (hereinafter sometimes referred to as the present circularly polarizing plate) is not provided on the display surface of the display element, for example, the circularly polarizing film from which the substrate is removed from the present circularly polarizing plate is used to display the display element. When installing on a surface, the base material may not be transparent. The transparent substrate means a substrate having transparency that can transmit light, particularly visible light, and the transparency refers to a characteristic in which the transmittance with respect to light having a wavelength of 380 to 780 nm is 80% or more. Specific examples of the transparent substrate include a translucent resin substrate. Examples of the resin constituting the translucent resin substrate include polyolefins such as polyethylene and polypropylene; Cyclic olefin resins, such as a norbornene-type polymer; 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; polysulfone; polyether sulfone; polyether ketone; Polyphenylene sulfide and polyphenylene oxide are mentioned. From the viewpoint of availability or transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin, or polycarbonate is preferable.

Cellulose ester is one in which some or all of the hydroxyl groups contained in cellulose are esterified, and can be easily obtained in the market. Moreover, a cellulose-ester base material can also be obtained easily in a market. Commercially available cellulose ester substrates include, for example, "Fuji Tack Film" (Fuji Shashin Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opt Co., Ltd.) etc. are mentioned.

Cyclic olefin resin can be obtained easily in a market. Commercially available cyclic olefin resins include "Topas" [Ticona Corporation (Germany)], "Aton" [JSR Corporation], "ZEONOR" [Nippon Zeon Corporation], "ZEONEX" [Nippon Zeon Co., Ltd.] and "Apel" (manufactured by Mitsui Chemicals Co., Ltd.) are mentioned. Such a cyclic olefin resin can be formed into a film by known means, such as a solvent casting method and a melt extrusion method, for example, and can be used as a base material. Moreover, a commercially available cyclic olefin resin base material can also be used. As a commercially available cyclic olefin resin base material, "Sucina" [Sekisui Chemical Co., Ltd.], "SCA40" [Sekisui Chemical Co., Ltd.], "Zeonoa Film" [Optess Co., Ltd.] and "Aton Film" [JSR Co., Ltd.] is mentioned.

When the cyclic olefin-based resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the content of the structural unit derived from the cyclic olefin is usually 50 mol% or less with respect to all the structural units of the copolymer, preferably 15 to 50 mol%. Examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene and alkyl-substituted styrene. When the cyclic olefin resin is a ternary copolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content of the structural unit derived from the chain olefin is usually 5 to 80 mol% with respect to the total structural units of the copolymer. , The content ratio of the structural unit derived from the aromatic compound having a vinyl group is usually 5 to 80 mol% with respect to the total structural units of the copolymer. Such a terpolymer has the advantage that the usage-amount of an expensive cyclic olefin can be made comparatively small in the manufacture.

Although the properties required for the substrate vary depending on the configuration of the circularly polarizing plate, a substrate having as little retardation as possible is usually preferred. As a base material with retardation property as small as possible, the cellulose-ester film which does not have retardation, such as Zero Tack (Konica Minolta Opt Co., Ltd.) and Z Tack (Fujifilm Co., Ltd.) is mentioned. Moreover, an unstretched cyclic olefin resin base material is also preferable.

In the case of a circularly polarizing plate in which a polarizing layer is formed on a substrate with or without an alignment film, and a retardation layer is formed on a polarizing layer through or without an alignment film, on the surface of the substrate on which the polarizing layer is not formed, Heart coat treatment, antireflection treatment, antistatic treatment, etc. may be applied. Moreover, the hard coat layer may contain additives, such as a ultraviolet absorber, in the range which does not affect performance.

When the thickness of the base material is too thin, the strength is lowered and the workability tends to be inferior. Therefore, it is usually 5 to 300 µm, preferably 20 to 200 µm.

The retardation layer is a coating layer whose birefringence Δn(λ) with respect to light having a wavelength of λnm satisfies Equations (1) and (2). A coating layer means the layer formed by application|coating.

Δn(450)/Δn(550)≤1.00 (1)

1.00≤Δn(650)/Δn(550) (2)

The birefringence Δn(λ) is obtained by measuring the retardation and dividing it by the thickness of the retardation layer. Although a specific measuring method is shown in an Example, at this time, the characteristic of a substantially retardation layer can be measured by measuring what was formed into a film on the base material which does not have retardation on the base material itself, such as a glass substrate.

The retardation layer is preferably formed by polymerizing one or more polymerizable liquid crystals (hereinafter, sometimes referred to as polymerizable liquid crystal (A)).

A polymerizable liquid crystal is a compound which has a polymeric group and has liquid crystallinity. The polymerizable group means a group involved in the polymerization reaction, and a photopolymerizable group is preferable. Here, the photopolymerizable group refers to a group capable of participating in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable. The liquid crystal may be either a thermotropic liquid crystal or a lyotropic liquid crystal, and may be either a nematic liquid crystal or a smectic liquid crystal if the thermotropic liquid crystal is classified by order.

Among them, thermotropic nematic liquid crystals are preferable from the viewpoint of film forming easiness, and from the viewpoint of imparting retardation properties represented by the above formulas (1) and (2), the following formula (A) A compound (hereinafter, sometimes referred to as compound (A)) is preferred. The said polymerizable liquid crystal may be used independently and may be combined.

[In formula (A), X ¹ represents an oxygen atom, a sulfur atom, or NR ¹ -. R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

Y ¹ represents a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent or a monovalent aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent.

Q ³ and Q ⁴ are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms which may optionally have a substituent, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent represents a monovalent aromatic hydrocarbon group, a halogen atom, a cyano group, a nitro group, -NR ² R ³ or -SR ² , or Q ³ and Q ⁴ are mutually bonded, and together with the carbon atom to which they are bonded, an aromatic ring or an aromatic ring form a summons R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

D ¹ and D ² are each independently a single bond, -C(=O)-O-, -C(=S)-O-, -CR ⁴ R ⁵ -, -CR ⁴ R ⁵ -CR ⁶ R ⁷ - , -O-CR ⁴ R ⁵ -, -CR ⁴ R ⁵ -O-CR ⁶ R ⁷ -, -CO-O-CR ⁴ R ⁵ -, -O-CO-CR ⁴ R ⁵ -, -CR ⁴ R ⁵ -O-CO-CR ⁶ R ⁷ -, -CR ⁴ R ⁵ -CO-O-CR ⁶ R ⁷ - or NR ⁴ -CR ⁵ R ⁶ - or CO-NR ⁴ -.

R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms.

G ¹ and G ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom or NH-, and the alicyclic hydrocarbon group The constituting methine group may be substituted with a tertiary nitrogen atom.

L ¹ and L ² each independently represent a monovalent organic group, and at least one of L ¹ and L ² has a polymerizable group]

In the compound (A), L ¹ is preferably a group represented by the formula (A1), and L ² is preferably a group represented by the formula (A2).

P ¹ -F ¹ -(B ¹ -A ¹ ) _k -E ¹ - (A1)

P ² -F ² -(B ² -A ² ) _l -E ² - (A2)

[In Formulas (A1) and (A2), B ¹ , B ² , E ¹ and E ² are each independently -CR ⁴ R ⁵ -, -CH ₂ -CH ₂ -, -O-, -S-, -CO-O-, -O-CO-O-, -CS-O-, -O-CS-O-, -CO-NR ¹ -, -O-CH ₂ -, -S-CH ₂ - or provided indicates bonding.

A ¹ and A ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, a sulfur atom or NH- may be substituted, and the methine group constituting the alicyclic hydrocarbon group may be substituted with a tertiary nitrogen atom.

k and l each independently represent an integer of 0-3.

F ¹ and F ² represent a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms.

P ¹ represents a polymerizable group.

P ² represents a hydrogen atom or a polymerizable group.

R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms]

As a preferable compound (A), the compound of Unexamined-Japanese-Patent No. 2011-207765 is mentioned.

As a specific example of a polymerizable liquid crystal, "3.8.6 Network (completely crosslinked type)" and "6.5.1 Liquid crystal material b. A compound having a polymerizable group among the compounds described in "Polymerizable nematic liquid crystal material" is exemplified.

The retardation layer is usually formed by applying a composition containing at least one polymerizable liquid crystal (A) on a substrate, an alignment film or a polarizing layer, and polymerizing the polymerizable liquid crystal (A) in the obtained coating film.

The alignment film in this invention has the orientation control force which liquid-crystal-aligns a polymeric liquid crystal in a desired direction.

It is preferable that the alignment film has solvent resistance that does not dissolve by application of a composition containing a polymerizable liquid crystal or the like, and also has heat resistance in heat treatment for removal of the solvent or alignment of the polymerizable liquid crystal. Examples of such an alignment film include an alignment film and a photo-alignment film containing an alignment polymer.

Examples of the orientation polymer include polyamide and gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, and hydrolyzate thereof. Polyethylenimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters are mentioned. Especially, polyvinyl alcohol is preferable. You may use combining 2 or more types of orientation polymers.

In the alignment film containing the alignment polymer, a composition in which the alignment polymer is dissolved in a solvent (hereinafter, sometimes referred to as an alignment polymer composition) is applied to a substrate and the solvent is removed, or the alignment polymer composition is applied to the substrate, and the solvent is removed And it is obtained by rubbing (rubbing method).

Examples of the solvent include alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether, ethyl acetate, butyl acetate, and ethylene glycol methyl ether acetate. , γ-butyrolactone, propylene glycol methyl ether acetate, ester solvents such as ethyl lactate, ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl isobutyl ketone, pentane, hexane , aliphatic hydrocarbon solvents such as heptane, aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile, ether solvents such as tetrahydrofuran and dimethoxyethane, and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. These solvents may be used independently and may be used in combination of 2 or more type.

The concentration of the orientation polymer in the orientation polymer composition should just be in a range in which the orientation polymer material can be completely dissolved in the solvent, but 0.1 to 20% is preferable in terms of solid content with respect to the solution, and more preferably about 0.1 to 10%.

As the orientation polymer composition, a commercially available orientation film material may be used as it is. Examples of commercially available alignment film materials include Saneva (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optoma (registered trademark, manufactured by JSR Corporation).

As a method of applying the oriented polymer composition to a substrate, a known method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, an applicator method, etc., a printing method such as a flexographic method can be heard When the present circularly polarizing plate is manufactured by a roll-to-roll type continuous manufacturing method to be described later, a printing method such as a gravure coating method, a die coating method or a flexographic method is usually employed as the coating method.

As a method of removing the solvent contained in an orientation polymer composition, the natural drying method, the ventilation drying method, heat drying, the reduced pressure drying method, etc. are mentioned.

In order to provide an orientation regulating force to an orientation film, it can rub as needed (rubbing method).

As a method of imparting an orientation regulating force by a rubbing method, a rubbing roll wound around a rubbing cloth and rotating, applying an orientation polymer composition to a base material and annealing it to make contact with a film of an orientation polymer formed on the base material surface.

The photo-alignment film is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, sometimes referred to as "composition for photo-alignment film formation") to a substrate and irradiating polarized light (preferably polarized UV). is obtained The photo-alignment film is more preferable in that the direction of the orientation regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group means group which raise|generates liquid-crystal orientation ability by irradiating light. Specific examples include groups involved in a photoreaction that is the origin of liquid crystal alignment ability, such as orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction of molecules generated by light irradiation. Among these, groups involved in dimerization reaction or photocrosslinking reaction are preferred from the viewpoint of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond, is preferable, and a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N A group having at least one selected from the group consisting of a bond) and a carbon-oxygen double bond (C=O bond) is particularly preferred.

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group and a cinnamoyl group. Examples of the photoreactive group having a C=N bond include a group having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C=O bond include a benzophenone group, a coumarin group, an anthraquinone group and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, or a halogenated alkyl group.

Among them, a photoreactive group involved in the photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group are preferable from the viewpoint that it is easy to obtain a photo-alignment film having a relatively small amount of polarized light irradiation required for photo-alignment, and excellent thermal stability and aging stability. do. As the polymer having a photoreactive group, one having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

By applying the composition for forming a photo-alignment film on the substrate, the photo-alignment organic layer can be formed on the substrate. Examples of the solvent contained in the composition include the same solvents contained in the alignment polymer composition described above, and may be appropriately selected according to the solubility of the polymer or monomer having a photoreactive group.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be appropriately adjusted depending on the type of polymer or monomer or the target thickness of the photo-alignment film, but is preferably at least 0.2 mass %, 0.3 to 10 The range of mass % is more preferable. As long as the properties of the photo-alignment film are not significantly impaired, the composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer.

The method for applying the composition for forming a photo-alignment film to the substrate includes the same method as the method for applying the alignment polymer composition to the substrate. As a method of removing a solvent from the applied composition for photo-alignment film formation, the method similar to the method of removing a solvent from an orientation polymer composition is mentioned, for example.

In order to irradiate the polarized light, a type in which the solvent is removed from the composition for forming a photo-alignment film applied on the substrate is directly irradiated with polarized UV, or the polarized light is irradiated from the substrate side, and the polarized light is transmitted and irradiated may be used. Moreover, it is especially preferable that the said polarization|polarized-light is substantially parallel light. The wavelength of polarized light to be irradiated is preferably in a wavelength range where the photoreactive group of a polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet rays) having a wavelength in the range of 250 to 400 nm is particularly preferable. Examples of the light source used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, and ultraviolet light lasers such as KrF and ArF, more preferably high-pressure mercury lamps, ultra-high pressure mercury lamps and metal halide lamps. do. These lamps are preferable because the emission intensity of ultraviolet rays having a wavelength of 313 nm is large. Polarized UV can be irradiated by irradiating light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan Thompson or Glan Taylor, or a wire grid type polarizer can be used.

On the other hand, if masking is performed when rubbing or polarized light irradiation, a plurality of regions (patterns) having different directions of liquid crystal alignment can also be formed.

The thickness of the alignment film (the alignment film and the photo-alignment film containing the alignment polymer) is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, still more preferably It ranges from 10 nm to 100 nm.

The composition containing at least one polymerizable liquid crystal (A) used for formation of the retardation layer (hereinafter, may be referred to as composition A) usually contains a solvent, and the solvent is the same as the solvent contained in the above-described alignment polymer composition. thing is mentioned, According to the solubility of a polymeric liquid crystal (A), it can select suitably.

Application of the composition A is usually performed by a known method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, an applicator method, or the like, or a printing method such as a flexographic method. After application|coating, a dry film is normally formed by removing a solvent on the conditions in which the polymeric liquid crystal (A) contained in the obtained coating film does not superpose|polymerize. Examples of the drying method include a natural drying method, a ventilation drying method, heat drying, and a reduced pressure drying method.

The polymerization of the polymerizable liquid crystal (A) can be performed by a known method for polymerizing a compound having a polymerizable functional group. Specific examples include thermal polymerization and photopolymerization, and photopolymerization is preferable from the viewpoint of easiness of polymerization. In the case of polymerizing the polymerizable liquid crystal (A) by photopolymerization, the polymerizable liquid crystal (A) in the dry film obtained by coating and drying the composition A containing the photopolymerization initiator is made into a liquid crystal state, and then the liquid crystal state is maintained. It is preferable to carry out photopolymerization as it is.

Photopolymerization is normally performed by irradiating light to a dry film. The irradiated light is appropriately selected according to the type of the photoinitiator contained in the dry film, the type of the polymerizable liquid crystal (A) (in particular, the type of photopolymerization group of the polymerizable liquid crystal (A)) and the amount thereof, specifically is light selected from the group consisting of visible light, ultraviolet light, and laser light, and an active electron beam. Among them, ultraviolet light is preferable from the viewpoint that it is easy to control the progress of the polymerization reaction and that one widely used in the art can be used as the photopolymerization device, and the polymerizable liquid crystal (A) can be photopolymerized by ultraviolet light. ) or the type of photoinitiator is preferable. In addition, at the time of polymerization, the polymerization temperature can also be controlled by irradiating light while cooling a dry film by an appropriate cooling means. When the polymerizable liquid crystal (A) is polymerized at a lower temperature by employing such a cooling means, a retardation layer can be appropriately formed even if a substrate having relatively low heat resistance is used. During photopolymerization, it is also possible to obtain a patterned retardation layer by masking or developing.

The sum total of the thickness of the retardation layer and the polarizing layer in this circularly polarizing plate is 10 micrometers or less. 0.5 micrometer or more and 9.5 micrometers or less are preferable and, as for the thickness of retardation layer, 1 micrometer or more and 5 micrometers or less are more preferable. 0.5 micrometer or more and 9.5 micrometers or less are preferable, and, as for the thickness of a polarizing layer, 1 micrometer or more and 5 micrometers or less are more preferable. The thickness of the retardation layer and the polarizing layer can be determined by measurement with an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

The polarizing layer contains a dichroic dye. A "dichroic dye" means a dye having a property in which the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different. As long as it has such a property, a dichroic dye is not restrict|limited, A dye may be sufficient and a pigment may be sufficient. Two or more kinds of dyes may be used in combination, two or more kinds of pigments may be used in combination, or dyes and pigments may be used in combination.

The dichroic dye preferably has a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. As such a dichroic dye, an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, and an anthraquinone dye are mentioned, Especially, an azo dye is preferable. As an azo dye, a monoazo dye, a bisazo dye, a trisazo dye, a tetrakis azo dye, and a stilbenazo dye are mentioned, A bisazo dye and a trisazo dye are preferable.

As an azo dye, the compound (Hereinafter, it is called "compound (1)" in some cases) represented by Formula (1) is mentioned.

A ¹ (-N=NA ² ) _p -N=NA ³ (1)

[In formula (1), A ¹ and A ³ independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. A ² represents a 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 or different from each other]

Examples of the monovalent heterocyclic group include a group in which one hydrogen atom is removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienotisol, imidazole, benzoimidazole, oxazole and benzooxazole. Examples of the divalent heterocyclic group include groups in which two hydrogen atoms are removed from the heterocyclic compound.

Substituents optionally having a phenyl group, a naphthyl group and a monovalent heterocyclic group for A ¹ and A ³ , and a p-phenylene group, a naphthalene-1,4-diyl group and a divalent heterocyclic group for A ² include 1 to carbon atoms an alkyl group of 4; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, and a butoxy group; a C1-C4 fluorinated alkyl group, such as a trifluoromethyl group; cyano group; nitro group; halogen atom; A substituted or unsubstituted amino group such as an amino group, a diethylamino group, or a pyrrolidino group (a substituted amino group is an amino group having one or two C1-C6 alkyl groups or two substituted alkyl groups bonded to each other to form an alkyl group having 2 to 8 carbon atoms) It means an amino group forming a candiyl group. The unsubstituted amino group is -NH ₂ ).

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

[In Formulas (1-1) to (1-6), B ¹ to B 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 substitution or an unsubstituted amino group (the definitions of the substituted amino group and the unsubstituted amino group are as described above), a chlorine atom or a trifluoromethyl group.

n1 to n4 each independently represent an integer of 0 to 3.

When n1 is 2 or more, a plurality of B ² may be the same or different from each other,

When n2 is 2 or more, a plurality of B ⁶ may be the same or different from each other,

When n3 is 2 or more, a plurality of B ⁹ may be the same or different from each other,

When n4 is 2 or more, a plurality of B ¹⁴ may be the same or different from each other]

As said anthraquinone pigment|dye, the compound represented by Formula (1-7) is preferable.

[In Formula (1-7), R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

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

As said oxazone dye, the compound represented by Formula (1-8) is preferable.

[In Formula (1-8), R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

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

As said acridine dye, the compound represented by Formula (1-9) is preferable.

[In formula (1-9), R ¹⁶ to R ²³ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

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

In formulas (1-7), (1-8) and (1-9), examples of the alkyl group having 1 to 6 carbon atoms for R ^x include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. , and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group and a naphthyl group.

As said cyanine dye, the compound represented by Formula (1-10), and the compound represented by Formula (1-11) are preferable.

[In formula (1-10), D ¹ and D ² each independently represent a group represented by any one of formulas (1-10a) to (1-10d).

n5 represents an integer of 1 to 3]

[In the formula (2-11), D ³ and D ⁴ each independently represent a group represented by any of the formulas (1-11a) to (1-11h).

n6 represents an integer of 1 to 3]

The polarizing layer is a coating layer. In addition, the polarizing layer contains a composition (hereinafter, sometimes referred to as composition B) containing one or more polymerizable liquid crystals (hereinafter, sometimes referred to as polymerizable liquid crystals (B)) serving as host compounds in addition to a dichroic dye. It is preferable to apply|coat and to form by superposing|polymerizing the polymeric liquid crystal (B) in the obtained coating film.

It is preferable that it is a smectic phase, and, as for the liquid-crystal state in which a polymeric liquid crystal (B) is seen, it is more preferable that it is a higher-order smectic phase from the point that a polarizing layer with a higher degree of orientation order can be manufactured. "Higher Smectic Award" means Smectic B Award, Smectic D Phase, Smectic E Award, Smectic F Award, Smectic G Award, Smectic H Award, Smectic I Award, Smectic J Award, Smectic K phase and smectic L phase, and among these, smectic B phase, smectic F phase and smectic I phase are more preferable. In the polarizing layer having a high degree of orientation order, Bragg peaks derived from higher-order structures such as hexatic phase and crystal phase are obtained in X-ray diffraction measurement. "Bragg peak" means a peak derived from the in-plane periodic structure of molecular orientation, and a polarizing layer having a periodic interval of 3.0 to 5.0 angstroms is preferable.

A polymerizable liquid crystal (B) showing a smectic phase is called a polymerizable smectic liquid crystal compound. Examples of the polymerizable smectic liquid crystal compound include a compound represented by the formula (B) (hereinafter, may be referred to as a compound (B)).

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

[In formula (B), X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. -CH ₂ - constituting the cyclohexane-1,4-diyl group may be substituted with -O-, -S- or -NR-. R represents 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-, a single bond, -N=N-, -CR ^a =CR ^b -, -C≡ C- or CR ^a =N-. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

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

V ¹ and V ² each independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - constituting the alkanediyl group is substituted with -O-, -S- or NH- It's fine to have]

A 1,4-phenylene group in which at least two of X ¹ , X ² and X ³ may have a substituent is preferable.

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

Examples of the substituent optionally included in the 1,4-phenylene group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a butyl group, a cyano group, and a halogen atoms can be mentioned.

Y ¹ 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, preferably a polymerizable group. It is preferable that U< ¹ > and U< ² > together are a polymerizable group, and it is preferable that it is a photopolymerizable group together. The "photopolymerizable group" means a group capable of participating in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later.

The photopolymerizable group represented by U ¹ and the polymerizable group represented by U ² may be different from each other, but they are preferably the same type of group. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable.

Examples of the alkanediyl group represented by V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5 group. -diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group and icosane-1,20-diyl group. V ¹ and V ² are preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

Examples of the substituent optionally included in the alkanediyl group include a cyano group and a halogen atom. The alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted or linear alkanediyl group.

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

As a compound (B), the compound represented by a formula (B-1) - a formula (B-25) is mentioned. When the compound (B) has a cyclohexane-1,4-diyl group, it is preferable that the cyclohexane-1,4-diyl group is a trans body.

Among them, formula (B-2), formula (B-3), formula (B-4), formula (B-5), formula (B-6), formula (B-7), formula (B-8) , at least one selected from the group consisting of compounds represented by formulas (B-13), (B-14), (B-15), (B-16) and (B-17) is preferable. .

The illustrated polymerizable liquid crystals (B) can be used alone or in combination. Moreover, when combining 2 or more types of polymerizable liquid crystal, it is preferable that at least 1 type is a polymerizable liquid crystal (B), and it is more preferable if 2 or more types are a polymerizable liquid crystal (B). By combining, liquid crystallinity can be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature in some cases. The mixing ratio in the case of combining two types of polymeric 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 polymerizable liquid crystal (B) is described, for example, in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or a known method described in Japanese Patent No. 4719156 is produced.

70-99.9 mass % is preferable with respect to solid content of a composition, and, as for the content rate of the polymeric liquid crystal (B) in composition B, 80-99.9 mass % is more preferable. If the content rate of a polymerizable liquid crystal (B) is in the said range, there exists a tendency for the orientation of a polymerizable liquid crystal (B) to become high. Here, "solid content" means the total amount of components excluding volatile components, such as a solvent, in composition B.

Although content of the dichroic dye in composition B can be suitably adjusted according to the kind etc. of a dichroic dye, 0.1 mass part or more and 50 mass parts or less are preferable with respect to 100 mass parts of polymerizable liquid crystal (B), 0.1 mass part 20 mass parts or less are more preferable, and 0.1 mass part or more and 10 mass parts or less are still more preferable. If content of a dichroic dye is in this range, it can superpose|polymerize, without disturbing the orientation of a polymerizable liquid crystal (B). When there is too much content of a dichroic dye, there exists a possibility of inhibiting the orientation of a polymerizable liquid crystal (B).

It is preferable that composition B contains a solvent. In general, since a smectic liquid crystal compound has a high viscosity, the composition containing a solvent is easy to apply, and as a result, it is easy to form a polarizing film in many cases. As a solvent, the same thing as the solvent contained in the above-mentioned orientation polymer composition is mentioned, According to the solubility of a polymerizable liquid crystal (B) and a dichroic dye, it can select suitably.

As for content of a solvent, 50-98 mass % is preferable with respect to the total amount of composition B. In other words, as for the solid content in composition B, 2-50 mass % is preferable.

Composition A and/or composition B preferably contain at least one leveling agent. A leveling agent adjusts the fluidity|liquidity of the composition B, has the function of making the coating film obtained by apply|coating composition B more flat, Specifically, surfactant is mentioned. As a leveling agent, at least 1 sort(s) selected from the group which consists of a leveling agent which has a polyacrylate compound as a main component, and a leveling agent which has a fluorine atom containing compound as a main component is preferable.

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

As a leveling agent containing a fluorine atom-containing compound as a main component, "Megapark (registered trademark) R-08", "R-30", "R-90", "F-410", and "F-411" , East "F-443", East "F-445", East "F-470", East "F-471", East "F-477", East "F-479", East "F-482" and Dong "F-483" [DIC Corporation]; "Sufflon (registered trademark) S-381", "S-382", "S-383", "S-393", "SC-101", "SC-105", "KH-" 40" and "SA-100" [AGC Seimi Chemical Co., Ltd.]; "E1830", "E5844" [Daikin Fine Chemicals Kyusho Co., Ltd.]; "Ftop EF301", "Ftop EF303", "Ftop EF351" and "Ftop EF352&quot;

When the composition A and/or the composition B contains a leveling agent, 0.05 mass parts or more and 5 mass parts or less are preferable with respect to 100 mass parts of polymeric liquid crystal, and, as for the content, 0.05 mass parts or more and 3 mass parts or less are more preferable. . It is easy to horizontally orientate a polymeric liquid crystal as content of a leveling agent is in an above-mentioned range, and there exists a tendency for the polarizing layer obtained to become smoother. When content of the leveling agent with respect to a polymeric liquid crystal is in an above-described range, there exists a tendency for unevenness to not arise easily in the polarizing layer obtained.

Composition A and/or composition B preferably contain at least one polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of the polymerizable liquid crystal (B), and a photopolymerization initiator is preferable from the viewpoint that the polymerization reaction can be initiated under lower temperature conditions. Specifically, a photopolymerization initiator capable of generating active radicals or acids by the action of light is exemplified, and among them, a photopolymerization initiator capable of generating radicals by the action of light is preferable.

Examples of the polymerization initiator include a benzoin compound, a benzophenone compound, an alkylphenone compound, an acylphosphine oxide compound, a triazine compound, an iodonium salt, and a sulfonium salt.

Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether are mentioned as a benzoin compound.

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

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morphopoly). Nophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy -2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1-[4-( and an oligomer of 1-methylvinyl)phenyl]propan-1-one.

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

Examples of the triazine compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4- 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)ethenyl ]-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine can

A commercially available polymerization initiator can be used. Commercially available polymerization initiators include "Irgacure (registered trademark) 907", "Irgacure (registered trademark) 184", "Irgacure (registered trademark) 651", "Irgacure (registered trademark) 819" ", "Irgacure (registered trademark) 250", "Irgacure (registered trademark) 369" (Chiba Japan Co., Ltd.); "Sakeall (registered trademark) BZ", "Sakeall (registered trademark) Z", "Sakeall (registered trademark) BEE" (Seiko Chemical Co., Ltd.); "kayacure (registered trademark) BP100" (Nippon Kayaku Co., Ltd.); "Kayacure (registered trademark) UVI-6992" (manufactured by Dow Corporation); "Adeka Optoma SP-152", "Adeka Optoma SP-170" (ADEKA Corporation); "TAZ-A", "TAZ-PP" (Nippon Shiiber Hegna Co., Ltd.); and "TAZ-104" (Sanwa Chemical).

When the composition A and/or the composition B contains a polymerization initiator, the content thereof can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal contained in the composition, and is 0.1 to 30 parts by mass per 100 parts by mass of the polymerizable liquid crystal. A mass part is preferable, 0.5-10 mass parts is more preferable, and 0.5-8 mass parts is still more preferable. If content of a polymerizable initiator is in this range, it can superpose|polymerize without disturbing the orientation of a polymerizable liquid crystal (B).

When the composition A and/or the composition B contains a photoinitiator, the composition may further contain a photosensitizer. Examples of the photosensitizer include xanthone compounds such as xanthone and thioxanthone (eg, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (eg, dibutoxyanthracene); phenothiazine and rubrene.

When composition A and/or composition B contains a photoinitiator and a photosensitizer, the polymerization reaction of the polymeric liquid crystal contained in the composition can be accelerated|stimulated more. The amount of the photosensitizer to be used can be appropriately adjusted depending on the type and amount of the photoinitiator and the polymerizable liquid crystal, preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal, 0.5-8 mass parts is more preferable.

In order to more stably advance the polymerization reaction of the polymerizable liquid crystal, the composition A and/or the composition B may contain an appropriate amount of a polymerization inhibitor, thereby making it easy to control the degree of progress of the polymerization reaction of the polymerizable liquid crystal.

As the polymerization inhibitor, hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butylcatechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, and other radical supplements ; thiophenols; β-naphthylamines and β-naphthols are mentioned.

When the composition A and/or the composition B contains a polymerization inhibitor, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal, and the amount of the photosensitizer used, etc., with respect to 100 parts by mass of the polymerizable liquid crystal. 0.1-30 mass parts is preferable, 0.5-10 mass parts is more preferable, 0.5-8 mass parts is still more preferable. If content of a polymerization inhibitor is in this range, it can superpose|polymerize without disturbing the orientation of a polymerizable liquid crystal.

A polarizing layer is normally formed by apply|coating the composition B on a base material, an orientation film, or retardation layer, and polymerizing the polymerizable liquid crystal (B) in the obtained coating film. A method of applying the composition is not limited. Examples of the alignment film include those described above.

A dry film is formed by apply|coating the composition B, and drying and removing a solvent under the conditions in which the polymeric liquid crystal (B) contained in the obtained coating film does not superpose|polymerize. Examples of the drying method include a natural drying method, a ventilation drying method, heat drying, and a reduced pressure drying method. When the polymerizable liquid crystal (B) is a polymerizable smectic liquid crystal compound, it is preferable to change the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dry film to a nematic phase (nematic liquid crystal state) and then to transition to the smectic phase. do. In order to form the smectic phase via the nematic phase, for example, the dried film is heated above the temperature at which the polymerizable smectic liquid crystal compound contained in the dry film undergoes phase transition to the liquid crystal state of the nematic phase, and then the polymerizable smectic liquid crystal compound is smectic. The method of cooling to the temperature which shows the liquid-crystal state of a Mectic phase is employ|adopted.

Next, after making the liquid-crystal state of the polymeric liquid crystal (B) in a dry film into a smectic phase, the method of photopolymerizing a polymeric liquid crystal (B) while maintaining the liquid-crystal state of a smectic phase is demonstrated. In the photopolymerization, the light irradiated to the dry film includes the type of photoinitiator contained in the dry film, the type of the polymerizable liquid crystal (B) (in particular, the type of photopolymerization group that the polymerizable liquid crystal (B) has) and the amount thereof. It is appropriately selected according to the light source, and specific examples thereof include light selected from the group consisting of visible light, ultraviolet light, and laser light and active electron beams. Among these, ultraviolet light is preferable at the point that it is easy to control advancing of a polymerization reaction, and the point that what is widely used in this field|area can be used as a photopolymerization apparatus. Therefore, it is preferable to select the kind of the polymerizable liquid crystal (B) or photoinitiator contained in the composition B so that it can be photopolymerized by ultraviolet light. In addition, at the time of polymerization, the polymerization temperature can also be controlled by irradiating light while cooling a dry film by an appropriate cooling means. When the polymerizable liquid crystal (B) is polymerized at a lower temperature by employing such a cooling means, a polarizing layer can be appropriately formed even if a substrate having relatively low heat resistance is used. When photopolymerizing, it is also possible to obtain a patterned polarizing layer by masking or developing.

By photopolymerizing, the polymerizable liquid crystal (B) is polymerized while maintaining a smectic phase, preferably a liquid crystal state of a higher smectic phase, to form a polarizing layer. The polarization layer obtained by polymerization of the polymerizable liquid crystal (B) while maintaining the liquid crystal state of the smectic phase is a conventional host-guest-type polarizing film, i.e., polarized light consisting of a liquid crystal state of a nematic phase, depending on the action of the dichroic dye. Compared with a film|membrane, there exists an advantage that polarization performance is high. Moreover, there exists an advantage of being excellent in intensity|strength compared with the thing which apply|coated only the dichroic dye or a lyotropic liquid crystal.

In the present circularly polarizing plate, the slow axis of the retardation layer and the absorption axis of the polarizing layer are neither parallel nor perpendicular to each other. In order to express a good function as a circularly polarizing plate, it is preferable that the angle which the slow axis of a retardation layer and the absorption axis of a polarizing layer make is substantially 45 degrees.

When manufacturing this circularly polarizing plate, the order of forming a retardation layer and a polarizing layer is arbitrary. After forming the retardation layer on the substrate, a polarizing layer may be formed on the retardation layer. After forming the polarizing layer on the substrate, a retardation layer may be formed on the polarizing layer. A polarizing layer may be formed on one surface of the substrate, and a retardation layer may be formed on the other surface of the substrate. An alignment film may be formed between the substrate and the retardation layer, the substrate and the polarizing layer, and/or the retardation layer and the polarizing layer.

When a polarizing layer is formed on the retardation layer after forming the retardation layer on the substrate, a protective layer may be formed on the retardation layer as needed, and a polarizing layer may be formed on the protective layer. An alignment film may be formed on the protective layer, and a polarizing layer may be formed thereon. Moreover, after forming a polarizing layer on a base material, you may form a protective layer on a polarizing layer, and you may form retardation layer on it. An alignment film may be formed on the protective layer, and a retardation layer may be formed thereon.

The protective layer is usually an acrylic oligomer or polymer composed of polyfunctional acrylate (methacrylate), urethane acrylate, polyester acrylate, epoxy acrylate, etc., polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylpyrrolidone. , starch, methyl cellulose, carboxymethyl cellulose, it is preferably formed of a composition for forming a protective layer containing a solvent and a water-soluble polymer such as sodium alginate.

The solvent contained in the composition for forming a protective layer includes the same solvents as those described above. Among them, at least one solvent selected from the group consisting of water, an alcohol solvent and an ether solvent dissolves the layer forming the protective layer. It is preferable that there is no Examples of the alcohol solvent include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether. Examples of the ether solvent include ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Among them, ethanol, isopropyl alcohol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferable.

The thickness of the protective layer is usually 20 µm or less. 0.5 micrometer or more and 9.5 micrometers or less are preferable, and, as for the thickness of a protective layer, 1 micrometer or more and 5 micrometers or less are more preferable. The thickness of the protective layer can be determined by measurement with an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

This circularly polarizing plate may further have an adhesive layer on the surface of the retardation layer or polarizing layer formed on the surface of this circularly polarizing plate. Moreover, you may have a primer layer between a retardation layer or a polarizing layer, and an adhesive layer.

The pressure-sensitive adhesive layer is formed of an adhesive, and the pressure-sensitive adhesive usually contains a polymer, and may contain a solvent.

Examples of the polymer include acrylic polymer, silicone polymer, polyester, polyurethane or polyether. Among them, the acrylic pressure-sensitive adhesive containing the acrylic polymer has excellent optical transparency, maintains appropriate wettability and cohesive force, has excellent adhesion, and furthermore, has high weather resistance and heat resistance. Since it is hard to produce peeling problems, such as these, it is preferable.

As the acrylic polymer, (meth)acrylate in which the alkyl group of the ester moiety is an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, or a butyl group (hereinafter, acrylate and methacrylate are collectively referred to as (meth)acrylate, acrylic acid and A copolymer of (meth)acrylic acid and (meth)acrylic monomer having a functional group such as (meth)acrylic acid or hydroxyethyl (meth)acrylate is preferable.

The pressure-sensitive adhesive containing such a copolymer is preferable because it is excellent in adhesiveness and can be peeled off relatively easily without generating glue residue or the like in the display device even when peeling it after bonding to the display device. 25 degrees C or less is preferable and, as for the glass transition temperature of the said acrylic polymer, 0 degrees C or less is more preferable. It is preferable that the weight average molecular weight of such an acrylic polymer is 100,000 or more.

As said solvent, the solvent etc. mentioned as a solvent of the above-mentioned orientation polymer composition are mentioned, for example.

Further, the pressure-sensitive adhesive may contain a light-diffusing agent. The light diffusing agent is for imparting light diffusivity to the pressure-sensitive adhesive layer, and may be fine particles having a refractive index different from that of the polymer included in the pressure-sensitive adhesive layer. can be heard Since the base polymer constituting the pressure-sensitive adhesive layer including the acrylic polymer has a refractive index of about 1.4, the light diffusing agent may be appropriately selected from those having a refractive index of about 1 to 2. The difference in refractive index between the polymer and the light diffusing agent which the pressure-sensitive adhesive contains as an active ingredient is usually 0.01 or more, and it is preferable to set it to 0.01 or more and 0.5 or less from the viewpoint of the brightness and visibility of the liquid crystal display device. It is preferable that the microparticles|fine-particles used as a light-diffusion agent have a spherical shape, and that it is also close to monodisperse, for example, the microparticles|fine-particles whose average particle diameter is in the range of about 2-6 micrometers are used suitably.

The refractive index is measured by the usual minimum declination or Abbe refractometer.

Examples of the fine particles made of the inorganic compound include aluminum oxide (refractive index 1.76) and silicon oxide (refractive index 1.45).

As fine particles made of an organic compound (polymer), for example, melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate/styrene copolymer resin beads (refractive index 1.50 to 1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46), silicone resin beads (refractive index 1.46), and the like.

The blending amount of the light diffusing agent can be appropriately determined in consideration of the haze required for the pressure-sensitive adhesive layer to which it is dispersed, the brightness of the liquid crystal display to which it is applied, and the like. Generally, 3 parts by weight per 100 parts by weight of the resin constituting the pressure-sensitive adhesive layer It is about 30 parts by weight.

The haze value of the pressure-sensitive adhesive layer in which the light-diffusing agent is dispersed is preferably in the range of 20 to 80% from the viewpoint of ensuring the brightness of the liquid crystal display device to which the circularly polarizing plate having the pressure-sensitive adhesive layer is applied and making it difficult to cause blurring or blurring of the display. do. A haze value is a value represented by (diffusion transmittance/total light transmittance) x 100 (%), and is measured according to JISK7105.

The thickness of the pressure-sensitive adhesive layer is determined depending on the adhesive strength and the like, and is not particularly limited, but is usually about 1 to 40 µm. In order to obtain a circularly polarizing plate provided with a thin adhesive layer without impairing characteristics, such as workability and durability, it is preferable that the thickness of an adhesive layer shall be about 3-25 micrometers. In addition, by setting the thickness of the pressure-sensitive adhesive layer to about 3 to 25 µm, brightness when the liquid crystal display device is viewed from the front or from an angle can be maintained, and smearing or blurring of the display can be made difficult to occur.

The primer layer usually contains a transparent resin, and is formed of a transparent resin solution. A primer layer can suppress the defect of a retardation layer or a polarizing layer when forming an adhesive layer. As transparent resin, it is excellent in coatability, and it is preferable that it is excellent in transparency and adhesiveness after primer layer formation.

The solvent for the transparent resin solution includes an aromatic hydrocarbon solvent such as benzene, toluene, and xylene, depending on the solubility of the transparent resin; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and isobutyl acetate; chlorinated hydrocarbon solvents such as methylene chloride, trichloroethylene and chloroform; Although general organic solvents such as alcohol solvents such as ethanol, 1-propanol, 2-propanol, and 1-butanol can be used, when the primer layer is formed using a transparent resin solution containing an organic solvent, the optical properties of the liquid crystal cured film are affected. Since it may affect, it is preferable to form a primer layer using the solution which uses water as a solvent.

An epoxy resin is mentioned as said transparent resin. A one-component curing type may be sufficient as an epoxy resin, and the thing of a 2-component curing type may be sufficient as it. A water-soluble epoxy resin is especially preferable. As the water-soluble epoxy resin, a polyamide epoxy resin obtained by reacting epichlorohydrin with a polyamide polyamine obtained by the reaction of a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid is used. can be heard Commercial products of such polyamide epoxy resin include "Sumirez Resin (registered trademark) 650(30)" and "Sumirez Resin (registered trademark) 675" (registered trademark) sold by Sumika Chemtex Co., Ltd. can

When using a water-soluble epoxy resin as said transparent resin, in order to further improve applicability|paintability, it is preferable to use together other water-soluble resin, such as a polyvinyl alcohol-type resin. Polyvinyl alcohol-based resins are partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, amino group-modified polyvinyl alcohol, such as modified polyvinyl alcohol. An alcohol-based resin is also good. Examples of suitable commercially available polyvinyl alcohol-based resins include "KL-318" (trade name), which is a polyvinyl alcohol containing an anionic group sold by Kuraray Co., Ltd.

When the primer layer is formed with a solution containing a water-soluble epoxy resin, the epoxy resin is preferably in the range of about 0.2 to 1.5 parts by weight based on 100 parts by weight of water. Moreover, when mix|blending a polyvinyl alcohol-type resin in this solution, it is preferable to make the quantity into about 1-6 weight part with respect to 100 weight part of water. The thickness of the primer layer is preferably in the range of about 0.1 to 10 µm.

The method for forming the primer layer is not limited, and various known coating methods such as a direct gravure method, a reverse gravure method, a die coat method, a comma coat method, and a bar coat method can be used.

The pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive to the surface of the retardation layer, the polarizing layer or the primer layer and drying, and applying the pressure-sensitive adhesive to the release-treated surface of the film subjected to the release treatment and drying After forming the pressure-sensitive adhesive layer, it can also be formed by a method of bonding the film having the pressure-sensitive adhesive layer to the surface of the retardation layer, the polarizing layer or the primer layer so that the pressure-sensitive adhesive layer side becomes the bonding surface. It is preferable to previously corona-discharge the primer layer surface on which the adhesive layer is formed. Thereby, the adhesiveness of a primer layer and an adhesive layer can be improved further.

As a method of apply|coating an adhesive, the method similar to that illustrated as a method of apply|coating an orientation polymer composition to a base material is mentioned, for example. Examples of the method for removing the solvent from the applied pressure-sensitive adhesive include the same method as the method for removing the solvent from the oriented polymer composition.

The peeling strength of this circularly polarizing plate which has an adhesive layer on the surface is measured by the following formula.

A 25 mm wide x 200 mm long test piece is cut from this circularly polarizing plate having an adhesive layer on its surface, the adhesive surface is bonded to a glass plate, and then one end of the test piece in the longitudinal direction using a tensile tester (one with a width of 25 mm) side), crosshead speed (gripper movement speed) 200 mm/min in an atmosphere of temperature 23°C and relative humidity of 60% JIS K 6854-1: 1999 「Adhesive-peel adhesion strength test method-Part 1: A 90 degree peel test based on "90 degree peel" is performed.

In a circularly polarizing plate having a substrate, a first alignment film, a polarizing layer, a second alignment film, a retardation layer, and an adhesive layer in this order, the peel strength (F1) between the substrate and the first alignment film is the first alignment film and the polarizing layer. It is preferable when it is lower than peeling strength (F2), the peeling strength (F3) of a 2nd orientation film, and retardation layer, and the peeling strength (F4) of a retardation layer and an adhesive layer. Peeling strength (F1) can be adjusted with a base material and a 1st alignment film.

For example, a substrate having a functional group forming a chemical bond with the alignment layer on the surface tends to have a high peel strength (F1) between the substrate and the first alignment layer. Accordingly, as the substrate for lowering the peel strength (F1), a substrate having few functional groups on the surface is preferable, and a substrate not subjected to surface treatment for forming functional groups on the surface is preferable.

In addition, the alignment layer having a functional group that forms a chemical bond with the substrate tends to have a high peel strength (F1) between the substrate and the first alignment layer. Therefore, as the alignment layer for lowering the peel strength (F1), an alignment layer with few functional groups forming a chemical bond with the substrate is preferable. In addition, in order to lower (F1), it is preferable that the orientation polymer composition or the composition for forming a photo-alignment film does not contain a reagent for crosslinking the substrate and the alignment film, and it is preferable that components such as a solvent for dissolving the substrate are not included. do. When the surface of the substrate is dissolved by the oriented polymer composition or the composition for forming a photo-alignment film, the peel strength (F1) between the substrate and the first alignment film tends to increase.

In order to increase the peel strength (F2), (F3) and (F4), a chemical bond may be formed between the first alignment layer and the polarizing layer, the second alignment layer and the retardation layer, and the retardation layer and the pressure-sensitive adhesive layer.

The circularly polarizing film which has an adhesive layer can be obtained by removing a base material from the circularly-polarizing plate which has an adhesive layer on the surface. Arbitrary methods are mentioned as a method of removing a base material.

The thickness of the circularly-polarizing film which has an adhesive layer is 5 micrometers or more and 15 micrometers or less normally, Preferably they are 5 micrometers or more and 10 micrometers or less. The thickness of the circularly polarizing film with an adhesive layer can be calculated|required by the measurement by an interference film thickness meter, a laser microscope, or a stylus type film thickness meter normally.

Next, the method of continuously manufacturing this circularly polarizing plate is demonstrated. As a suitable method for manufacturing such a continuous circularly polarizing plate, the method by a roll-to-roll type is mentioned.

Specifically, (1) the step of preparing a roll in which the base material is wound around the core,

(2) continuously feeding the substrate from the roll;

(3) a step of continuously forming an alignment film on the substrate;

(4) applying the composition A on the alignment film to continuously form a retardation layer;

(5) a step of continuously forming a protective layer on the retardation layer of the roll obtained in (4) above;

(6) applying an alignment film on the protective layer obtained in (5) above to continuously form;

(7) applying the composition B on the alignment film obtained in (6) above to continuously form a polarizing layer;

(8) the step of bonding the film having the pressure-sensitive adhesive layer on the polarizing layer obtained in the above (7) so that the pressure-sensitive adhesive layer side becomes a bonding surface;

(9) The method of winding up the circularly-polarizing plate obtained continuously around a 2nd core, and performing the process of obtaining a 2nd roll sequentially is mentioned. In addition, you may abbreviate|omit steps (5) and (8) as needed.

In addition, (1a) the step of preparing a roll in which the base material is wound on the core,

(2a) continuously feeding the substrate from the roll;

(3a) a step of continuously forming an alignment film on the substrate;

(4a) applying the composition B on the alignment layer to continuously form a polarizing layer;

(5a) a step of continuously forming a protective layer on the polarizing layer of the roll obtained in (4a) above;

(6a) applying an alignment film on the protective layer obtained in (5a) above to continuously form;

(7a) applying the composition A on the alignment film obtained in the above (6a) to continuously form a retardation layer;

(8a) the step of bonding the film having the pressure-sensitive adhesive layer on the retardation layer obtained in the above (7a) so that the pressure-sensitive adhesive layer side becomes a bonding surface;

(9a) The method of winding up the circularly-polarizing plate obtained continuously to a 2nd core, and performing the process of obtaining a 2nd roll sequentially is also mentioned. In addition, you may abbreviate|omit steps (5a) and (8a) as needed.

In addition, (1b) the step of preparing a roll in which the base material is wound around the core,

(2b) continuously feeding the substrate from the roll;

(3b) continuously forming an alignment film on the substrate;

(4b) applying the composition A on the alignment film to continuously form a retardation layer;

(5b) applying an alignment film to the surface opposite to the retardation layer of the roll obtained in (4b) above and continuously forming it;

(6b) applying the composition B on the alignment film obtained in (5b) above to continuously form a polarizing film;

(7b) The method of winding up the circularly-polarizing plate obtained continuously to a 2nd core, and performing the process of obtaining a 2nd roll sequentially is also mentioned.

In addition, (1c) a step of preparing a roll in which the transparent substrate is wound on the core,

(2c) continuously sending out the transparent substrate from the roll;

(3c) continuously forming an alignment film on the transparent substrate;

(4c) applying a composition containing the composition B on the alignment layer to continuously form a polarizing layer;

(5c) a step of continuously forming an alignment film on the surface opposite to the polarizing layer of the roll obtained in (4c) above;

(6c) applying the composition A on the alignment film obtained in (5c) above to continuously form a retardation layer;

(7c) The method of winding up the circularly-polarizing plate obtained continuously to a 2nd core, and performing the process of obtaining a 2nd roll sequentially is also mentioned.

1 shows a schematic diagram of the present circularly polarizing plate. 1(a) is a circularly polarizing plate in which a base material, a retardation layer, and a polarizing layer are laminated in this order. 1(b) is a circularly polarizing plate in which a base material, a polarizing layer, and a retardation layer are laminated in this order.

This circularly polarizing plate can be used for various display devices. Moreover, the circularly-polarizing plate which has an adhesive layer on the surface can be used for manufacture of various display devices. Specifically, by bonding a circularly polarizing plate having an adhesive layer on its surface to a display surface of a display device through the adhesive layer, a display device having the present circularly polarizing plate can be obtained, and further, by removing the base material, the circularly polarizing light of the present invention A display device having a circularly polarizing film provided with the film can be obtained.

A display device is a device which has a display element, and contains a light emitting element or a light emitting device as a light emitting source. As the display device, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (such as a field emission display device (FED), a surface electric field Emission display device (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg grating light valve (GLV) display device, display with digital micromirror device (DMD)) device) and piezoelectric ceramic displays, etc. The liquid crystal display includes any of a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, a direct view liquid crystal display, and a projection liquid crystal display. These display devices may be a display device that displays a two-dimensional image or a three-dimensional display device that displays a three-dimensional image. It can be effectively used for a display device.

2 is a schematic diagram showing a liquid crystal display device 10 which is one of the display devices of the present invention. The liquid crystal layer 15 is interposed between the two substrates 12a and 12b. A color filter 13 is disposed on the liquid crystal layer 15 side of the substrate 12a. The color filter 13 is arranged at a position facing the pixel electrode 20 with the liquid crystal layer 15 interposed therebetween, and the black matrix 18 is arranged at a position facing the boundary between the pixel electrodes. A transparent electrode 14 covers them. An overcoat layer may be provided between the color filter 13 and the transparent electrode 14 .

The thin film transistor 19 and the pixel electrode 20 are regularly arranged on the liquid crystal layer 15 side of the substrate 12b. The pixel electrode 20 is disposed at a position facing the color filter 13 with the liquid crystal layer 15 interposed therebetween. An interlayer insulating film 16 having a connection hole (not shown) is disposed between the thin film transistor 19 and the pixel electrode 20 .

A glass substrate and a plastic substrate are mentioned as the board|substrate 12a and the board|substrate 12b. When manufacturing the color filter 13 or the thin film transistor 19 formed on these board|substrates, when it is necessary to heat to high temperature, it is preferable that the board|substrate 12a and the board|substrate 12b are glass substrates.

Examples of the thin film transistor 19 include a high-temperature polysilicon transistor formed on a quartz substrate, a low-temperature polysilicon transistor formed on a glass substrate, and an amorphous silicon transistor formed on a glass substrate or a plastic substrate. In order to reduce the size of the liquid crystal display device, a driver IC may be formed on the substrate 12b.

A liquid crystal layer 15 is disposed between the transparent electrode 14 and the pixel electrode 20 . A spacer 21 is formed in the liquid crystal layer 15 to maintain a constant distance between the substrate 12a and the substrate 12b. Alignment films for aligning the liquid crystal compound contained in the liquid crystal layer 15 in a desired direction may be respectively disposed on the surfaces of the layers formed on the substrate 12a and the substrate 12b in contact with the liquid crystal layer 15 .

Each member includes a substrate 12a, a color filter 13 and a black matrix 18, a transparent electrode 14, a liquid crystal layer 15, a pixel electrode 20, an interlayer insulating film 16 and a thin film transistor 19; and the substrate 12b.

This circularly polarizing plate 11a and this circularly polarizing plate 11b are laminated|stacked on the outer side of the board|substrate 12a and the board|substrate 12b with this liquid-crystal layer 15 interposed therebetween. A backlight unit 17 serving as a light emitting source is disposed outside the circularly polarizing plate 11b. The backlight unit 17 includes a light source, a light guide, a reflection plate, a diffusion sheet, and a viewing angle adjustment sheet. As a light source, various light sources, such as an electroluminescent (EL), a cold cathode tube, a hot cathode tube, a light emitting diode (LED), a laser light source, and a mercury lamp, can be used.

3 is a schematic diagram showing an organic EL display device 30 which is one of the display devices of the present invention. The organic EL display device 30 of the present invention shown in FIG. 3A includes the circular polarizing plate 31 and is formed on a substrate 32 on which a pixel electrode 34 is formed through an interlayer insulating film 33 . , the light emitting layer 35 and the cathode electrode 36 are stacked. A circularly polarizing plate 31 viewed opposite to the light emitting layer 35 is disposed with the substrate 32 interposed therebetween. The light emitting layer 35 emits light by applying a positive voltage to the pixel electrode 34 and a negative voltage to the cathode electrode 36 and applying a direct current between the pixel electrode 34 and the cathode electrode 36 . The light emitting layer 35 includes an electron transport layer, a light emitting layer, and a hole transport layer. Light emitted from the light emitting layer 35 passes through the pixel electrode 34 , the interlayer insulating film 33 , the substrate 32 , and the circularly polarizing plate 31 .

In order to manufacture the organic EL display device 30 , the thin film transistor 38 is first formed on the substrate 32 in a desired shape. Then, an interlayer insulating film 33 is formed, and then the pixel electrode 34 is formed and patterned by sputtering. After that, the light emitting layer 35 is laminated.

Next, the circularly polarizing plate 31 is provided on the surface of the substrate 32 opposite to the surface on which the thin film transistor 38 is provided. In that case, the quarter wavelength layer of the present circularly polarizing plate 31 is arranged so as to be on the substrate 32 side.

As the substrate 32, a sapphire glass substrate, a quartz glass substrate, a soda glass substrate, and a ceramic substrate such as alumina; metal substrates such as copper; A plastic substrate etc. are mentioned. Although not shown, a thermally conductive film may be formed on the substrate 32 . Examples of the thermally conductive film include a diamond thin film (DLC, etc.). When the pixel electrode 34 is of a reflective type, light is emitted in a direction opposite to that of the substrate 32 . Therefore, not only transparent materials, but also non-transmissive materials such as stainless steel can be used. The substrate may be formed singly, or may be formed as a laminated substrate by bonding a plurality of substrates with an adhesive. In addition, these board|substrates are not limited to a plate-shaped thing, A film may be sufficient.

As the thin film transistor 38, for example, a polycrystalline silicon transistor or the like may be used. The thin film transistor 38 is provided at the end of the pixel electrode 34, and the size thereof is about 10 to 30 mu m. Meanwhile, the pixel electrode 34 has a size of about 20 μm×20 μm to 300 μm×300 μm.

A wiring electrode of the thin film transistor 38 is provided on the substrate 32 . The wiring electrode has a low resistance and has a function of electrically connecting to the pixel electrode 34 to suppress the resistance value low. Generally, the wiring electrode is made of Al, Al, a transition metal (except Ti), Ti or nitride. Those containing any 1 type or 2 or more types of titanium (TiN) are used.

An interlayer insulating film 33 is provided between the thin film transistor 38 and the pixel electrode 34 . The interlayer insulating film 33 is formed by sputtering or vacuum deposition of an inorganic material such as silicon oxide such as SiO ₂ and silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), photoresist, polyimide, and acrylic. Any one may be sufficient as long as it has insulation, such as a coating film of resin-type materials, such as resin.

Ribs 39 are formed on the interlayer insulating film 33 . The ribs 39 are disposed at the periphery of the pixel electrode 34 (between adjacent pixels). As a material of the rib 39, an acrylic resin, polyimide resin, etc. are mentioned. The thickness of the ribs 39 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, the EL element comprising the pixel electrode 34 , the light emitting layer 35 , and the cathode electrode 36 will be described. The light emitting layer 35 has at least one hole transport layer and a light emitting layer, respectively, and has, for example, 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 34 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO ₂ , and In ₂ O ₃ , and ITO and IZO are particularly preferable. The thickness of the pixel electrode 35 may be at least a certain thickness capable of sufficiently performing hole injection, and is preferably set to about 10 to 500 nm.

The pixel electrode 34 can be formed by a vapor deposition method (preferably a sputtering method). The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr, and Xe or a mixed gas thereof may be used.

As a constituent material of the cathode electrode 36, for example, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn and Zr may be used. In order to improve operational stability, it is preferable to use the alloy system of two-component or three-component selected from the exemplified metal elements. Examples of the alloy system include Ag·Mg (Ag: 1 to 20 at%), Al·Li (Li: 0.3 to 14 at%), In·Mg (Mg: 50 to 80 at%), and Al·Ca (Ca: 5). -20 at%) and the like.

The cathode electrode 36 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 1-500 nm or more.

The hole injection layer has a function of facilitating injection of holes from the pixel electrode 34, and the hole transport layer has a function of transporting holes and blocking electrons, and is also called a charge injection layer or a charge transport layer.

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

As the light emitting layer 35, light emission from singlet excitons (fluorescence) is used, light emission from triplet excitons is used (phosphorescence), light emission from singlet excitons (fluorescence) is used, and light emission from triplet excitons is used (fluorescence). Phosphorescence), those formed by organic substances, those formed by organic substances and those formed by inorganic substances, those containing high molecular weight materials, low molecular weight materials, high molecular weight materials and low molecular weight materials, etc. Available. However, it is not limited to this, The light emitting layer 35 using various well-known objects for EL elements can be used for the organic electroluminescent display device 30. As shown in FIG.

A desiccant (not shown) is disposed in the space between the cathode electrode 36 and the sealing layer 37 . This is because the light emitting layer 35 is weak against humidity. Deterioration of the light emitting layer 35 is prevented by absorbing moisture by the desiccant.

The organic EL display device 30 of the present invention shown in FIG. 3(b) has the circular polarizing plate 31 and is formed on the substrate 32 on which the pixel electrode 34 is formed through the interlayer insulating film 33. The light emitting layer 35 and the cathode electrode 36 are stacked. A sealing layer 37 is formed on the cathode electrode, and the circularly polarizing plate 31 viewed opposite to the substrate 32 is disposed. The light emitted from the light emitting layer 35 passes through the cathode electrode 36 , the sealing layer 37 , and the circularly polarizing plate 31 .

Example

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

Example 1

[Preparation of the composition for forming a retardation layer]

The following components were mixed, and the composition for phase difference layer formation was obtained by stirring the obtained mixture at 80 degreeC for 1 hour.

Compound A1 and Compound A2 were synthesized by the method described in Japanese Patent Application Laid-Open No. 2010-31223.

Compound A1 (80 parts):

Compound A2 (20 parts):

Polymerization initiator (6 parts): 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals)

Leveling agent (0.1 part): polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)

Solvent: mixed solvent of o-xylene (300 parts) and cyclopentanone (130 parts)

[Preparation of composition for photo-alignment film formation]

The following components were mixed, and the composition for photo-alignment film formation was obtained by stirring the obtained mixture at 80 degreeC for 1 hour.

Optical Orientation Materials (Part 5):

Solvent (95 parts): cyclopentanone

[Preparation of a composition for forming a polarizing layer]

The following components were mixed, and the composition for polarizing layer formation was obtained by stirring the obtained mixture at 80 degreeC for 1 hour. Compound B1 and Compound B2 were synthesized by the method described in Japanese Patent No. 4719156.

Compound B1 (Compound (B-6); 75 parts)

Compound B2 (Compound (B-7); 25 parts)

dichroic pigment;

Bisazo compound (1-1-1) 2.5 parts

Bisazo compound (1-1-2) 2.5 parts

Bisazo compound (1-4-1) 2.5 parts

polymerization initiator; 6 parts of 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals)

leveling agent; 1.5 parts of polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)

solvent; 250 parts of cyclopentanone

[Measurement of phase transition temperature]

The obtained composition for polarizing layer formation was apply|coated on glass, it dried, and produced the sample for a measurement. As a result of confirming the phase transition temperature by observation of the texture by a polarizing microscope, the phase transition from 108° C. to the nematic phase and from 101° C. to the smectic A phase at 76° C. A phase transition to Smectic B phase was confirmed, respectively.

[Preparation of a composition for forming a pressure-sensitive adhesive]

The following components were mixed at 55 degreeC in nitrogen atmosphere, and the acrylic resin was obtained.

70 parts of butyl acrylate

20 parts of methyl acrylate

Acrylic acid 1.0 part

Initiator: 0.2 parts of azobisisobutyronitrile

Solvent (80 parts): ethyl acetate

Further, 0.5 parts of Colonate L (75% ethyl acetate solution of the trimethylolpropane adduct of tolylene diisocyanate, the number of isocyanate groups in one molecule: 3, manufactured by Nippon Urethane Kogyo Co., Ltd.) 0.5 parts, silane coupling agent X-12-981 ( 0.5 part of Shin-Etsu Silicone Co., Ltd. product) was mixed, and finally, ethyl acetate was added so that total solid content concentration might be 10 %, and it was set as the composition for adhesive formation. The obtained composition for forming a pressure-sensitive adhesive is applied to the release-treated surface of a release-treated polyethylene terephthalate film (manufactured by Lintech Co., Ltd.) so that the thickness after drying is 10 µm using an applicator, dried at 100° C. for 1 minute, and has a pressure-sensitive adhesive Film (1) was obtained.

[Manufacture of circularly polarizing plate]

1. Formation of alignment film for polarizing layer

As the transparent base film, KC4UY (TAC film, manufactured by Konica Minolta Co., Ltd.), which is a cellulose-based film, was used. The said composition for photo-alignment film formation was apply|coated on this film by the bar-coating method, and it heat-dried in 60 degreeC drying oven for 1 minute. The obtained dry film was subjected to polarization UV irradiation treatment to form a first alignment film. Polarization UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). In addition, the polarization direction of the polarized UV was made to be 0° with respect to the slow axis of the retardation layer.

2. Formation of a polarizing layer

The composition for forming a polarizing layer was apply|coated by the bar-coating method on the formed 1st alignment film, After heating and drying for 1 minute in 120 degreeC drying oven, it cooled to room temperature. A polarizing layer was formed by irradiating the dried film with ultraviolet rays at an exposure dose of 1200 mJ/cm 2 (based on 365 nm) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). It was 1.8 micrometers when the thickness of the obtained polarizing layer was measured with the laser microscope (OLS3000 by Olympus Corporation).

3. Formation of a protective layer

On the formed polarizing layer, 50 parts of dipentaerythritol hexaacrylate (Aronix M-403 manufactured by Toagosei Co., Ltd.), 50 parts of acrylate resin (Evecryl 4858 manufactured by Daicel UCB Co., Ltd.) and 2-methyl-1[4 A solution (composition for forming a protective layer) prepared by dissolving 3 parts of -(methylthio)phenyl]-2-morpholinopropan-1-one (Irgacure 907; manufactured by Chiba Specialty Chemicals) in 250 parts of isopropanol is applied. It apply|coated by the coating method, and it heat-dried for 1 minute in 50 degreeC drying oven. A protective layer was formed on the polarizing layer by irradiating the obtained dry film with ultraviolet rays at an exposure dose of 400 mJ/cm 2 (based on 365 nm) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.).

4. Formation of alignment film for retardation layer

On the formed protective layer, the composition for forming a photo-alignment film was applied by a bar coating method, and dried by heating in a drying oven at 60°C for 1 minute. The obtained dry film was subjected to polarization UV irradiation treatment to form a second alignment film. Polarization UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). In addition, the polarization direction of polarization|polarized-light UV was performed so that it might become 45 degrees with respect to the absorption axis of a polarizing layer.

5. Formation of retardation layer

On the formed 2nd alignment film, the composition for phase difference layer formation was apply|coated by the bar-coating method, after heating and drying for 1 minute in 120 degreeC drying oven, it cooled to room temperature. A retardation layer was formed by irradiating the obtained dry film with ultraviolet rays with an exposure amount of 1000 mJ/cm 2 (based on 365 nm) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). It was 2.0 micrometers when the thickness of the obtained retardation layer was measured with the laser microscope (OLS3000 by Olympus Corporation).

In this way, a broadband circularly polarizing plate could be produced. The total thickness of this circularly polarizing plate was measured by a contact-type film thickness meter and found to be 45 µm.

[Evaluation of circularly polarizing plate]

1. X-ray diffraction measurement

About the obtained polarizing layer, X-ray-diffraction measurement was performed with the X-ray-diffraction apparatus X'Pert PRO MPD (made by Spectris Corporation). Using Cu as a target, X-rays generated under the conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV are passed through a fixed divergence slit 1/2° in the rubbing direction (in advance, obtain the rubbing direction of the alignment film under the polarization layer) , and the measurement was performed by scanning in 2θ = 0.01671° steps in the scanning range of 2θ = 4.0 to 40.0°. As a result, a sharp diffraction peak with a peak full width at half maximum (FWHM) = about 0.29° was obtained in the vicinity of 2θ = 20.12°. In addition, the same result was obtained also when the measurement was carried out by making X-rays incident in the direction perpendicular to the rubbing. The order period (d) obtained at the peak position was about 4.4 Å, indicating that a structure reflecting the higher-order smectic phase was formed.

2. Measurement of reflectance

In order to confirm the usefulness of the circularly polarizing plate, the reflectance was measured as follows. The retardation layer of the produced circularly polarizing plate and the reflective plate (mirror surface aluminum plate) were bonded together using the adhesive, and the measurement sample was prepared.

Using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation), light in the wavelength range of 400 to 700 nm is incident in 2 nm steps in a direction normal to the measurement sample at 12°, and the reflectance of the reflected light is measured. did. If the reflectance is calculated as 100% when the reflectance is measured by placing only the reflector without bonding the circular polarizing plate, the reflectance of light in the wavelength range of 400 to 700 nm is about 1 to 10%, sufficient antireflection properties over the entire visible light range was found to be obtainable.

Example 2

In the same manner as in Example 1, a first alignment film (polarization direction of polarized UV is 45° with respect to the long side of the base film) was formed on one side of the transparent base film, and a retardation layer was formed on the photo-alignment film. After forming a protective layer on the retardation layer, a second alignment layer (polarization direction of polarized UV is 0° with respect to the long side of the base film) is formed, and a polarizing layer is further formed on the photo-alignment layer to produce a circularly polarizing plate did.

In the same manner as in Example 1, the reflectance was measured by bonding the transparent base film and the reflecting plate of the produced circularly polarizing plate using an adhesive, and the reflectance of light having a wavelength in the range of 400 to 700 nm was about 1 to 10%, over the entire visible light spectrum. It was found that sufficient antireflection properties could be obtained.

Example 3

Example 1 except that compound (B-14) was used in place of compound (B-6) as polymerizable liquid crystal compound B1, and compound (B-17) was used in place of compound (B-7) as polymerizable liquid crystal compound B2, respectively. A circularly polarizing plate was manufactured in the same manner as described above.

As in Example 1, the reflectance was measured by bonding the retardation layer and the reflecting plate of the produced circular polarizing plate using an adhesive, and the reflectance of light having a wavelength in the range of 400 to 700 nm is about 1 to 10%, sufficient throughout the visible light. It was found that anti-reflection properties could be obtained.

Comparative Example 1

As the retardation film, a quarter-wave plate (Zeonoa Film, Nippon Zeon Co., Ltd., in-plane retardation value Ro: 138 nm), which is a uniaxially stretched film of a cyclic olefin resin, was used as the retardation film, and in the same manner as in Example 1, the retardation film was A first alignment film (polarization direction of polarization UV is 45° with respect to the slow axis of the retardation film) was formed on one surface, and a polarizing layer was further formed on the first alignment film to prepare a circularly polarizing plate.

As in Example 1, the produced circularly polarizing plate was bonded to the reflecting plate using an adhesive to measure the reflectance. The reflectance of light with a wavelength of 500 to 600 nm is a good reflectance of about 1 to 10%, but at a wavelength of 400 to 500 nm. It can be seen that the reflectance of light and the reflectance of light having a wavelength of 600 to 700 nm are more than 10%, and the reflected light is blue-violet, so that sufficient antireflection function cannot be obtained.

Comparative Example 2

As a polarizing plate, an iodine-PVA polarizing plate (105 µm thick, manufactured by Sumikaran Sumitomo Chemical Co., Ltd.) was cut into small pieces of 100×100 mm so that the absorption axis was 0°. The 1/2 wave plate used in Example 1 was cut into small pieces of 100×100 mm so that the slow axis was 15°. The 1/4 wave plate used in Comparative Example 1 was cut into small pieces of 100×100 mm so that the slow axis was 15°. Each of the cut out films was sheet-wafer-bonded using an acrylic adhesive (25 micrometers in film thickness) so that it might become a polarizing plate+1/4 wave plate+1/2 wave plate, and the circularly polarizing plate was produced.

As in Example 1, the produced circularly polarizing plate was bonded to the reflecting plate using an adhesive to measure the reflectance, and the reflectance of light having a wavelength in the range of 400 to 700 nm is about 1 to 10%, sufficient antireflection properties over the entire visible light was found to be obtained, but the total thickness of the circularly polarizing plate was measured by a contact-type film thickness meter, and as a result, it was 240 μm, which was about 5 times the total thickness of the circularly polarizing plate of Example 1.

Example 4

A circularly polarizing plate was manufactured in the same manner as in Example 1 except that a polyethylene terephthalate film was used instead of the KC4UY (TAC film, manufactured by Konica Minolta Co., Ltd.), which is a cellulose-based film as a substrate. On the retardation layer of this circularly-polarizing plate, the film (1) with an adhesive was bonded together, and the circularly-polarizing plate which has an adhesive layer was obtained. This sample was cut to a size of 40 mm x 40 mm, the film of the film with the bonded adhesive was peeled off, pressed to a reflective plate (mirror aluminum plate), and the substrate was slowly removed to obtain a reflective plate with a circularly polarizing film . The thickness of the circularly polarizing film comprising the first alignment layer, the polarizing layer, the protective layer, the second alignment layer, the retardation layer and the pressure-sensitive adhesive layer was 14.7 μm.

The peel strength (F1) between the substrate and the first alignment layer is the peel strength between the first alignment layer and the polarizing layer (F2), the peel strength between the second alignment layer and the retardation layer (F3), and the peel strength between the retardation layer and the pressure-sensitive adhesive layer Since it was lower than (F4), peeling arose between the base material and the 1st alignment film, and the base material was able to be removed.

When the reflectance was measured in the same manner as in Example 1, it was found that the reflectance of light having a wavelength in the range of 400 to 700 nm was about 1 to 10%, and sufficient antireflection properties could be obtained over the entire visible light range. Since this antireflection principle is the same principle as the reflection of external light in the metal electrode of the organic EL display, it is suitably used for the organic EL display as well.

The circularly polarizing plate of the present invention has sufficient performance as a broadband circularly polarizing plate, and its thickness can satisfy thinning of a display device, and its manufacturing process is also simple. Moreover, the display device provided with the circularly polarizing plate of this invention can achieve thickness reduction.

1: This circularly polarizing plate 2: Substrate
3: retardation layer 4: polarizing layer
5: dichroic dye 10: liquid crystal display device
11a, 11b: this circularly polarizing plate 12a, 12b: substrate
13: color filter 14: transparent electrode
15: liquid crystal layer 16: interlayer insulating film
17: backlight unit 18: black matrix
19: thin film transistor 20: pixel electrode
21: spacer 30: organic EL display device
31: this circularly polarizing plate 32: substrate
33: interlayer insulating film 34: pixel electrode
35: light emitting layer 36: cathode electrode
37: sealing layer 38: thin film transistor
39: rib

Claims (21)

It has a substrate, a retardation layer, and a polarizing layer,
The birefringence Δn (λ) of the retardation layer with respect to light having a wavelength of λ nm satisfies Equations (1) and (2),
The retardation layer and the polarizing layer are both a coating layer,
The polarizing layer contains an azo dye,
The sum of the thicknesses of the retardation layer and the polarizing layer is 10 µm or less, and
The polarizing layer contains a dichroic dye represented by the following formula,
a protective layer between the polarizing layer and the retardation layer;
The thickness of the protective layer is 1 μm or more and 5 μm or less,
The protective layer is formed of a composition for forming a protective layer containing a water-soluble polymer,
A circularly polarizing plate, characterized in that the polarizing layer is formed by polymerizing one or more polymerizable smectic liquid crystal compounds.
Δn(450)/Δn(550)≤1.00 (1)
1.00≤Δn(650)/Δn(550) (2)
A ¹ (-N=NA ² ) _p -N=NA ³
[wherein, A ¹ and A ³ each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. A ² represents a 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 or different.] The circularly polarizing plate according to claim 1, wherein the retardation layer is formed by polymerizing one or more polymerizable liquid crystals. The circularly polarizing plate according to claim 1, wherein the polymerizable smectic liquid crystal compound is polymerized by irradiation with light. The circularly polarizing plate according to claim 2, wherein the polymerizable liquid crystal is polymerized by irradiation with light. The circularly polarizing plate according to claim 1 or 2, wherein the polarizing layer is a polarizing layer capable of obtaining a Bragg peak in X-ray diffraction measurement. The circularly polarizing plate according to claim 1 or 2, wherein the retardation layer and the polarizing layer each have a thickness of 5 µm or less. The circularly polarizing plate according to claim 1 or 2, wherein the retardation layer, the polarizing layer, or both of them are formed on the alignment film. The circularly polarizing plate according to claim 7, wherein the alignment layer is an alignment layer in which an alignment regulating force is generated by irradiation with light. The circularly polarizing plate according to claim 7, wherein the alignment layer has a thickness of 500 nm or less. The circularly polarizing plate according to claim 1 or 2, wherein the retardation layer is formed on the substrate through or without the alignment film, and the polarizing layer is formed on the retardation layer through or without the alignment film. The circularly polarizing plate according to claim 1 or 2, wherein a polarizing layer is formed on the substrate with or without an alignment film, and a retardation layer is formed on the polarizing layer through or without an alignment film. delete The circularly polarizing plate according to claim 1 or 2, wherein a polarizing layer is formed on one side of the substrate through or without an alignment film, and a retardation layer is formed on the other side of the substrate through or without an alignment film. The circularly polarizing plate according to claim 1 or 2, further comprising a pressure-sensitive adhesive layer on the surface of the retardation layer or the polarizing layer. The circularly polarizing plate according to claim 14, comprising a substrate, a first alignment layer, a polarizing layer, a protective layer, a second alignment layer, a retardation layer, and an adhesive layer in this order. The method according to claim 15, wherein the peel strength (F1) between the substrate and the first alignment layer is the peel strength (F2) between the first alignment layer and the polarizing layer, the peel strength between the second alignment layer and the retardation layer (F3), and the retardation layer A circularly polarizing plate lower than the peeling strength (F4) of the pressure-sensitive adhesive layer. A display device comprising the circularly polarizing plate according to claim 1 or 2 and a display element. A display device having a circularly polarizing film in which the circularly polarizing film from which the substrate is removed from the circularly polarizing plate according to claim 14 is bonded to a display surface of a display element through an adhesive layer of the circularly polarizing film. The display device of claim 18 , wherein the circularly polarizing film has a thickness of 5 μm or more and 15 μm or less. The display device according to claim 17, wherein the display element is a liquid crystal cell, an organic electroluminescent element, or a touch panel. 15. A method of manufacturing a display device having a circularly polarizing film, wherein the circularly polarizing plate according to claim 14 is bonded to a display surface of a display element through an adhesive layer of the circularly polarizing plate, and the substrate is removed from the circularly polarizing plate.

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