TWI606278B - Facial polarizer, display device with dnsinging film and manufacturing method thereof - Google Patents

Description

Circular polarizing plate, display device with circular polarizing film and manufacturing method thereof

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

There is known a liquid crystal display device including a wide-band circularly polarizing plate comprising a iodine-dyed polyvinyl alcohol polarizing film, a 1/2 wavelength plate, and a 1/4 wavelength plate. In the wide-band circularly polarizing plate, the angle formed by the retardation axis of the 1/2 wavelength plate and the absorption axis of the polarizing film, and the angle formed by the retardation axis of the 1/4 wavelength plate and the absorption axis of the polarizing film must be formed. Since each layer is offset by 15° or 75°, it is difficult to form the circular polarizing plate by roll-to-roll bonding. On the other hand, the thickness of the display device is also strongly required, and therefore, the circular polarizing plate is required to be thinner.

Patent Document 1 discloses a circularly polarizing plate having a thickness of 130 to 370 μm in which a reverse wavelength dispersible film and a polarizing element obtained by applying a dichroic dye are laminated on a retardation layer. Patent Document 2 discloses a circularly polarizing plate having a thickness of 36 to 205 μm, which is obtained by laminating a polarizing element containing a substance of a thermotropic liquid crystal or a lyotropic liquid crystal on a retardation layer.

[Previous Technical Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-337892

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-251288

However, the circularly polarizing plate disclosed in Patent Document 1 is one in which two films are attached via an adhesive. Since the coating is laminated, the ease of the manufacturing steps and the thickness of the circular polarizing plate are not sufficiently satisfied. The circularly polarizing plate disclosed in Patent Document 2 exhibits a positive wavelength dispersion property due to the phase difference layer, and thus the performance as a wide-band circularly polarizing plate is insufficient.

The invention includes the following invention.

[1] A circularly polarizing plate comprising: a substrate, a retardation layer, and a polarizing layer, wherein the birefringence Δn(λ) of the retardation layer for light having a wavelength of λ nm satisfies the formula (1) and the formula (1) 2) The retardation layer and the polarizing layer are both coating layers, and the total 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).

[2] The circularly polarizing plate of [1], wherein the phase difference layer is formed by polymerizing one or more polymerizable liquid crystals.

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

[4] The circular polarizing plate of [2] or [3], wherein the polymerizable liquid crystal is polymerized by light irradiation.

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

[6] The circularly polarizing plate according to any one of [1] to [5] wherein the thickness of the phase difference layer and the polarizing layer are each 5 μm or less.

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

[8] The circular polarizing plate of [7], wherein the alignment film is an alignment film which generates an alignment restricting force by light irradiation.

[9] The circular polarizing plate of [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 the substrate with or without an alignment film, and a polarizing layer is formed on the retardation layer with 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 the substrate with or without an alignment film, and a phase difference layer is formed on the polarizing layer with or without an alignment film.

[12] The circularly polarizing plate of [10] or [11], wherein a protective layer is included between the polarizing layer and the phase difference layer.

[13] The circularly polarizing plate according to any one of [1] to [9] wherein a polarizing layer is formed on one side of the substrate with or without an alignment film, with or without an alignment film on the other side of the substrate. A phase difference layer is formed.

[14] The circularly polarizing plate according to any one of [1] to [13] wherein the adhesive layer is further included on the surface of the retardation layer or the polarizing layer.

[15] The circular polarizing plate of [14], wherein the substrate, the first alignment film, the polarizing layer, the second alignment film, the retardation layer, and the adhesive layer are sequentially included.

[16] The circular polarizing plate of [15], wherein a peeling strength (F1) of the substrate and the first alignment film is lower than a peeling strength (F2) of the first alignment film and the polarizing layer, and a second alignment film and a retardation layer Peel strength (F3) and peel strength (F4) of the retardation layer and the adhesive layer.

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

[18] A display device with a circularly polarizing film, wherein the circularly polarizing film obtained by removing the substrate from the circular polarizing plate of any one of [14] to [16] is passed through an adhesive layer of the circular polarizing film. It is made up of the display surface of the display element.

[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 single Element, organic electroluminescent element or touch panel.

[21] A method of manufacturing a display device with a circularly polarizing film, wherein the circularly polarizing plate according to any one of [14] to [16] is attached to a display element via an adhesive layer of the circular polarizing plate The surface is displayed and the substrate is removed from the circular polarizer.

According to the present invention, a thin and wide-band circular polarizing plate and a display device including the same can be provided.

1‧‧‧The circular polarizer

2‧‧‧Substrate

3‧‧‧ phase difference layer

4‧‧‧ polarizing layer

5‧‧‧ dichroic pigment

10‧‧‧Liquid crystal display device

11a, 11b‧‧‧ this circular polarizer

12a, 12b‧‧‧ substrate

13‧‧‧Color filters

14‧‧‧Transparent electrode

15‧‧‧Liquid layer

16‧‧‧Interlayer insulating film

17‧‧‧Backlight unit

18‧‧‧Black matrix

19‧‧‧Thin film transistor

20‧‧‧pixel electrode

21‧‧‧Parts

30‧‧‧Organic EL display device

31‧‧‧The circular polarizer

32‧‧‧Substrate

33‧‧‧Interlayer insulating film

34‧‧‧pixel electrode

35‧‧‧Lighting layer

36‧‧‧Cathode electrode

37‧‧‧ Sealing layer

38‧‧‧film transistor

39‧‧‧ blocking wall

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

Fig. 2 is a schematic view showing a liquid crystal display device including the circularly polarizing plate of the present invention.

3(a) and 3(b) are schematic views showing an organic EL display device including a circularly polarizing plate of the present invention.

The substrate is typically a transparent substrate. In addition, when the base material of the circularly polarizing plate of the present invention (hereinafter sometimes referred to as a circular polarizing plate) is not provided on the display surface of the display element, for example, a circularly polarizing film obtained by removing the substrate from the circular polarizing plate. When disposed on the display surface of the display element, the substrate may be non-transparent. The transparent substrate refers to a substrate having transparency to allow light, particularly visible light to pass through, and the term "transparency" refers to a property of a transmittance of light having a wavelength of 380 to 780 nm of 80% or more. As a specific transparent base material, a translucent resin base material is mentioned. Examples of the resin constituting the light-transmitting resin substrate include polyolefins such as polyethylene and polypropylene; a cyclic olefin resin such as an olefin polymer; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; triethylene fluorene cellulose, diacetyl cellulose, acetic acid propionate fiber Cellulose esters such as phthalocyanine; polyethylene naphthalate; polycarbonate; polyfluorene; polyether oxime; polyether ketone; polyphenylene sulfide and polyphenylene ether. From the viewpoint of availability or transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cyclic olefin resin or polycarbonate is preferred.

Any one or all of the hydrocarbon groups contained in the cellulose ester-based cellulose may be easily obtained from the market by esterification. Further, the cellulose ester substrate can also be easily obtained from the market. Examples of the commercially available cellulose ester substrate include "Fujitac Film" (Fuji Film Co., Ltd.); "KC8UX2M", "KC8UY", and "KC4UY" (Konica Minolta Opto).

The cyclic olefin resin can be easily obtained from the market. Examples of the commercially available cyclic olefin-based resin include "Topas" [Ticona (Germany)], "Arton" [JSR (share)], "ZEONOR" [Japan ZEON (share)], "ZEONEX" [Japan ZEON (share)] and "APEL" [Mitsui Chemical (share) manufacturing]. Such a cyclic olefin-based resin can be formed into a substrate by a known method such as a solvent casting method or a melt extrusion method. Further, a commercially available cyclic olefin resin substrate can also be used. As a commercially available cyclic olefin-based resin substrate, "S-SINA" [Sui Shui Chemical Industry Co., Ltd.], "SCA40" [Sekisui Chemical Industry Co., Ltd.], "ZEONOR Film" [Optes] ] and "Arton Film" [JSR (share)].

In the case where the cyclic olefin resin is a copolymer of a cyclic olefin and a chain olefin or a vinyl compound having a vinyl group, the content ratio of the structural unit derived from the cyclic olefin is usually relative to the total structural unit of the copolymer. 50 mol% or less, preferably 15 to 50 mol%. Examples of the chain olefin include ethylene and propylene. Examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene, and alkyl-substituted styrene. In the case where 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 ratio of the structural unit derived from the chain olefin is relative to the total structural unit of the copolymer. Usually, it is 5 to 80 mol%, and 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 unit of the copolymer. Such terpolymers have the advantage of relatively reducing the amount of expensive olefins used in their manufacture.

The characteristics required for the substrate vary depending on the constitution of the circular polarizing plate, and it is generally preferred that the substrate has a phase difference as small as possible. As a substrate with as small a phase difference as possible, it can be listed A cellulose ester film having no phase difference such as ZeroTAC (Konica Minolta Opto Co., Ltd.) or Z-TAC (Fuji Film Co., Ltd.). Further, a cyclic olefin-based resin substrate which is not extended is also preferable.

In the case where a polarizing layer is formed on the substrate with or without the alignment film, and a circularly polarizing plate on which the retardation layer is formed on the polarizing layer with or without the alignment film, the surface of the substrate on which the polarizing layer is not formed may be used. Hard coating treatment, anti-reflection treatment, antistatic treatment, and the like. Further, the hard coat layer may contain an additive such as an ultraviolet absorber in a range that does not affect the performance.

When the thickness of the substrate is too thin, the strength tends to decrease and the workability tends to be deteriorated. Therefore, the thickness is usually 5 to 300 μm, preferably 20 to 200 μm.

The phase difference layer satisfies the coating layers of the formulas (1) and (2) with respect to the birefringence Δn(λ) of light having a wavelength of λ nm. The coating layer refers to a layer formed by coating.

△n(450)/△n(550)≦1.00 (1)

1.00≦△n(650)/△n(550) (2)

The birefringence Δn(λ) can be obtained by measuring the retardation and dividing by the thickness of the phase difference layer. The specific measurement method is disclosed in the examples. In this case, the properties of the substantially phase difference layer can be measured by measuring a film formed on a substrate having no retardation on the substrate itself such as a glass substrate.

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

The polymerizable liquid crystal is a compound having a polymerizable group and having liquid crystallinity. The polymerizable group means a group which participates in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group which can participate 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 acryloxy group, a methacryloxy group, and an oxirane group ( Oxiranyl), oxetanyl, and the like. Among them, preferred are acryloxy group, methacryloxy group, vinyloxy group, oxirane group and oxetane. The alkyl group is more preferably an acryloxy group. The liquid crystal property may be a thermotropic liquid crystal or a lyotropic liquid crystal. If the thermotropic liquid crystal is classified in order of order, the nematic liquid crystal may be a smectic liquid crystal.

In view of the easiness of film formation, a thermotropic nematic liquid crystal is preferable, and from the viewpoint of imparting phase difference represented by the above formula (1) and the above formula (2), It is preferably a compound represented by the following formula (A) (hereinafter sometimes referred to as a compound (A)). The polymerizable liquid crystals may be used singly or in combination.

[In the 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; and Y ¹ represents a carbon number of 6 to 12 which may have a substituent. a valent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent; and Q ³ and Q ⁴ each independently represent a hydrogen atom and may have a substituent having 1 to 20 carbon atoms An aliphatic hydrocarbon group having a valence of 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, a halogen atom, a cyano group, a nitro group, and -NR ² R ³ or -SR ² , or Q ³ and Q ⁴ are bonded to each other to form an aromatic ring or an aromatic heterocyclic ring together with the bonded carbon atoms; and R ² and R ³ each independently represent a hydrogen atom or a carbon number of 1~ 6 alkyl; D ¹ and D ² each independently represent 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 independently represents an alicyclic hydrocarbon group having a carbon number of 5 to 8, and the methylene group constituting the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom or NH- to form a methine group of the alicyclic hydrocarbon group. It 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]

It is preferable that L ¹ in the compound (A) is 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 the formulae (A1) and (A2), B ¹ , B ² , E ¹ and E ² each independently represent -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 a single bond ; A ¹ and A ² each independently represent an alicyclic hydrocarbon group having a carbon number of 5 to 8 or an aromatic hydrocarbon group having a carbon number of 6 to 18; and the methylene group constituting the alicyclic hydrocarbon group may be through an oxygen atom. a sulfur atom or an NH-substituent, 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 to 3; and F ¹ and F ² represent a carbon number of 1 to 12; a divalent aliphatic hydrocarbon group; P ¹ represents a polymerizable group; P ² represents a hydrogen atom or a polymerizable group; and R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms]

Preferred compounds (A) include the compounds disclosed in JP-A-2011-207765.

Specific examples of the polymerizable liquid crystal include: "3.8.6 Network (completely cross-linked type)" and "6.5.1" of a liquid crystal handbook (edited by the Liquid Crystal Handbook Compilation Committee, Maruzen (share) issued on October 30, 2000). A compound having a polymerizable group among the compounds described in the liquid crystal material b. The polymerizable nematic liquid crystal material.

The retardation layer is usually formed by applying a composition containing one or more kinds of polymerizable liquid crystals (A) onto a substrate, an alignment film or a polarizing layer to polymerize the polymerizable liquid crystal (A) in the obtained coating film. .

The alignment film in the present invention is one in which the polymerizable liquid crystal has an alignment regulating force in the liquid crystal alignment in a desired direction.

The alignment film preferably has solvent resistance which is not dissolved by application of a composition containing a polymerizable liquid crystal, and heat resistance in heat treatment for removing a solvent or aligning a polymerizable liquid crystal. By. Examples of the alignment film include an alignment film containing an alignment polymer and a photo alignment film.

Examples of the alignment polymer include polyamine or gelatin having a guanamine bond in the molecule, polyimine having a quinone bond in the molecule, and polyglycolic acid or polyvinyl alcohol as a hydrolyzate thereof. Alkyl modified polyvinyl alcohol, polypropylene decylamine, poly Oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylates. Among them, polyvinyl alcohol is preferred. It is also possible to use two or more kinds of the alignment polymers in combination.

The alignment film containing an orienting polymer can be usually applied to a substrate by a composition in which an alignment polymer is dissolved in a solvent (hereinafter sometimes referred to as an alignment polymer composition), the solvent is removed, or the alignment is performed. The polymer composition is applied to a substrate, and the solvent is removed to obtain a friction (friction method).

Examples of the solvent include alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl stilbene, butyl sarbuta, and propylene glycol monomethyl ether; ethyl acetate and butyl acetate; Ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, ethyl lactate and other ester solvents, acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl A ketone solvent such as a ketone or methyl isobutyl ketone; an aliphatic hydrocarbon solvent such as pentane, hexane or heptane; an aromatic hydrocarbon solvent such as toluene or xylene; a nitrile solvent such as acetonitrile; tetrahydrofuran or dimethoxyethane; Ether solvent and chlorinated hydrocarbon solvent such as chloroform or chlorobenzene. These solvents may be used singly or in combination of two or more.

The concentration of the alignment polymer in the alignment polymer composition may be a range in which the alignment polymer material can be completely dissolved in the solvent, and is preferably 0.1 to 20% in terms of the solid content of the solution, and further Good is about 0.1 to 10%.

As the alignment polymer composition, a commercially available alignment film material can be used as it is. Examples of the commercially available alignment film material include Sunever (registered trademark, manufactured by Nissan Chemical Industries Co., Ltd.), Optomer (registered trademark, manufactured by JSR Co., Ltd.), and the like.

Examples of the method of applying the alignment polymer composition to the substrate include a coating method such as a spin coating method, an extrusion coating method, a gravure coating method, a die coating method, a bar coating method, and a dressing method. A known method such as a printing method such as a flexographic printing method. In the case where the circular polarizing plate is produced by a continuous manufacturing method in the form of Roll to Roll described later, the coating method generally employs a printing method such as a gravure coating method, a die coating method or a flexographic printing method. .

Examples of the method for removing the solvent contained in the alignment polymer composition include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.

In order to impart an alignment restricting force to the alignment film, rubbing (friction method) can be performed as needed.

As a method of imparting an alignment regulating force by a rubbing method, a method of forming an oriented polymer film formed on a surface of a substrate by applying an alignment polymer composition to a substrate and annealing the film, contact roll A friction roller wound with a rubbing cloth and rotating.

The photo-alignment film is usually applied to a substrate by a composition containing a photoreactive group-containing polymer or a monomer and a solvent (hereinafter sometimes referred to as "photo-alignment film-forming composition"), and is irradiated with polarized light. (preferably polarized UV (polarized ultraviolet light)) is obtained. The light alignment film can be more preferably controlled by arbitrarily controlling the direction of the alignment regulating force by selecting the polarization direction of the polarized light to be irradiated.

The term "photoreactive group" means a group which generates a liquid crystal alignment ability by light irradiation. Specific examples of the photoreaction of the origin of the liquid crystal alignment ability, such as the alignment induction or isomerization reaction, the dimerization reaction, the photocrosslinking reaction, or the photodecomposition reaction, which are generated by light irradiation. Among them, the group participating in the dimerization reaction or the photocrosslinking reaction is preferred in terms of excellent alignment. The photoreactive group is preferably a group having an unsaturated bond, particularly a double bond, and particularly preferably having a carbon-carbon double bond (C=C bond) and a carbon-nitrogen double bond (C=N bond). a group of at least one of a group consisting of a nitrogen-nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyalkenyl group, a decyl group, a styrylpyridyl group, a styryl pyridyl group, a chalcone group, and a cinnamyl group. Examples of the photoreactive group having a C=N bond include a group having a structure such as an aromatic Schiff base or an aromatic fluorene. Examples of the photoreactive group having an N=N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an oxyazobenzene structure. . Examples of the photoreactive group having a C=O bond include a benzophenone group, a coumarin group, a fluorenyl 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, it is preferred that the photoreactive group participating in the photodimerization reaction is preferable in that it is easy to obtain a photoalignment film having a small amount of polarized light irradiation and excellent thermal stability or stability over time. It is a cinnamyl group and a chalcone group. As the polymer having a photoreactive group, it is particularly preferred that the terminal portion of the side chain of the polymer has a cinnamic acid structure having a cinnamic acid structure.

The photoalignment inducing layer can be formed on the substrate by applying the photo-alignment film-forming composition onto the substrate. The solvent contained in the composition may be the same as the solvent contained in the above-mentioned alignment polymer composition, and may be appropriately selected depending on 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 photoalignment film formation can be appropriately adjusted depending on the kind of the polymer or monomer or the target thickness of the photo-alignment film, and is preferably at least 0.2% by mass. More preferably, it is in the range of 0.3 to 10% by mass. The photo-alignment film-forming composition may contain a polymer material such as polyvinyl alcohol or polyimine or a photosensitizer, within a range that does not significantly impair the characteristics of the photo-alignment film.

The method of applying the composition for forming a light alignment film to a substrate is the same as the method of applying the alignment polymer composition to the substrate. The method of removing the solvent from the coated photo-alignment film-forming composition is, for example, the same method as the method of removing the solvent from the self-aligning polymer composition.

The polarized light irradiation may be a form in which the polarizing UV is directly applied to the composition for removing the photo-alignment film formed on the substrate, or may be a form in which the polarized light is irradiated from the substrate side to cause the polarized light to penetrate. . Moreover, the polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength region where the photoreactive group of the photoreactive group or the photoreactive group of the monomer absorbs 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 in the polarized light irradiation include xenon lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and more preferably high pressure mercury lamps, ultrahigh pressure mercury lamps, and metal halide lamps. These lamps are preferred because of the large luminous intensity of ultraviolet rays having a wavelength of 313 nm. The polarized light UV can be irradiated by irradiating light from the above-mentioned light source through an appropriate polarizing element. As the polarizing element, a polarizing filter or a polarizing element such as a Glan Thompson or a Glan Taylor or a wire grid type polarizing element can be used.

Further, when performing rubbing or polarized light irradiation, if a masking is performed, a plurality of regions (patterns) having different directions of liquid crystal alignment may be formed.

The thickness of the alignment film (the alignment film containing the alignment polymer and the photo alignment film) 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, and still more preferably in the range of 10 nm to 100 nm. .

The composition containing one or more types of polymerizable liquid crystals (A) used in the formation of the retardation layer (hereinafter sometimes referred to as composition A) usually contains a solvent, and examples of the solvent include the above-mentioned alignment polymer composition. The solvent contained in the same can be suitably selected according to the solubility of the polymerizable liquid crystal (A).

The coating of the composition A is usually known by a coating method such as a spin coating method, an extrusion coating method, a gravure coating method, a die coating method, a bar coating method, a dressing method, or the like, or a printing method such as a flexographic printing method. The method is carried out. After the application, the dry film is usually formed by removing the solvent under the condition that the polymerizable liquid crystal (A) contained in the obtained coating film is not polymerized. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.

The polymerization of the polymerizable liquid crystal (A) can be carried out by a known method of polymerizing a compound having a polymerizable functional group. Specific examples thereof include thermal polymerization and photopolymerization, and from the viewpoint of easiness of polymerization, photopolymerization is preferred. In the case where the polymerizable liquid crystal (A) is polymerized by photopolymerization, it is preferred to apply a polymerizable liquid crystal (A) in a dried film obtained by applying the composition A containing a photopolymerization initiator and drying it. After the liquid crystal phase is obtained, photopolymerization is carried out while maintaining the liquid crystal state.

Photopolymerization is usually carried out by irradiating light onto a dried film. The light to be irradiated is based on the type of the photopolymerization initiator contained in the dried film, the type of the polymerizable liquid crystal (A) (especially the type of photopolymerizable group which the polymerizable liquid crystal (A) has), and the amount thereof. A suitable selection may be, for example, light selected from the group consisting of visible light, ultraviolet light, and laser light, and an active electron beam. Among them, in terms of easy control of the progress of the polymerization reaction and use as a photopolymerization device in a wide range of users in the field, ultraviolet light is preferred, and photopolymerization by ultraviolet light is preferred. In the manner, the kind of the polymerizable liquid crystal (A) or the photopolymerization initiator is selected. Further, at the time of polymerization, the polymerization temperature may be controlled by light irradiation while cooling the dried film by an appropriate cooling means. When the polymerization of the polymerizable liquid crystal (A) is carried out at a lower temperature by using such a cooling mechanism, the retardation layer can be appropriately formed even if a substrate having low heat resistance is used. When photopolymerizing, it can also be masked or displayed. A patterned phase difference layer is obtained by shadowing or the like.

The total thickness of the phase difference layer and the polarizing layer in the circular polarizing plate is 10 μm or less. The thickness of the retardation layer is preferably 0.5 μm or more and 9.5 μm or less, and more preferably 1 μm or more and 5 μm or less. The thickness of the polarizing layer is preferably 0.5 μm or more and 9.5 μm or less, and more preferably 1 μm or more and 5 μm or less. The thickness of the retardation layer and the polarizing layer can be generally determined by measurement using an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

The polarizing layer contains a dichroic dye. The "dichroic dye" refers to a dye having a property in which the absorbance in the long-axis direction of the molecule is different from the absorbance in the short-axis direction. In the case of such a property, the dichroic dye is not limited and may be a dye or a pigment. Two or more kinds of dyes may be used in combination, or two or more kinds of pigments may be used in combination, and a dye and a pigment may be used in combination.

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

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

A ¹ (-N=NA ² ) _p -N=NA ³ (1)

[In the formula (1), A ¹ and A ³ each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent or a monovalent heterocyclic group which may have a substituent; and A ² represents a substituent which may have a substituent a p-phenylene group, a naphthalene-1,4-diyl group which may have a substituent or a divalent heterocyclic group which may have a substituent; p represents an integer of 1 to 4; and 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: quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, Azole, benzo A heterocyclic compound such as azole removes a group of one hydrogen atom. Examples of the divalent heterocyclic group include a group in which two hydrogen atoms are removed from the above heterocyclic compound.

Examples of the phenyl group, the naphthyl group and the monovalent heterocyclic group in A ¹ and A ³ and the substituent of the phenyl group, the naphthalene-1,4-diyl group and the divalent heterocyclic group in A ² . Examples thereof include an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, and a butoxy group; and a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group. a cyano group; a nitro group; a halogen atom; a substituted or unsubstituted amine group such as an amine group, a diethylamino group or a pyrrolidinyl group (the so-called substituted amine group means having one or two carbon numbers) An amine group of an alkyl group of 1 to 6, or an alkyl group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms; an unsubstituted amine group -NH ₂ ).

Among the compounds (1), a compound represented by any one of the following formulas (1-1) to (1-6) is preferred.

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

The above-mentioned anthraquinone dye is preferably a compound represented by the formula (1-7).

[In the 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 a carbon number of 1 ~4 alkyl or carbon 6 to 12 aryl]

As above The ketone dye is preferably a compound represented by the formula (1-8).

[In the 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 a carbon number of 1 ~4 alkyl or carbon 6 to 12 aryl]

The acridine dye is preferably a compound represented by the formula (1-9).

[In the formula (1-9), R ¹⁶ to R ²³ independently of each other represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom; R ^x represents a carbon number of 1 ~4 alkyl or carbon 6 to 12 aryl]

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

The cyanine dye is preferably a compound represented by the formula (1-10) and a compound represented by the formula (1-11).

[In the formula (1-10), D ¹ and D ² independently represent a group represented by any one of the formulae (1-10a) to (1-10d);

N5 represents an integer from 1 to 3]

[In the formula (2-11), D ³ and D ⁴ represent each other independently of the formula (1-11a) to the formula (1-11h);

N6 represents an integer from 1 to 3]

The polarizing layer is a coating layer. In addition, the polarizing layer is preferably a composition containing one or more polymerizable liquid crystals (hereinafter sometimes referred to as polymerizable liquid crystals (B)) which are main compounds, in addition to the dichroic dye. The composition B) is formed by polymerizing the polymerizable liquid crystal (B) in the obtained coating film.

The liquid crystal state exhibited by the polymerizable liquid crystal (B) is preferably a smectic phase, and in order to produce a polarizing layer having a higher degree of alignment, it is more preferably a high-order layer phase. The term "high-order stratigraphic phase" refers to the layer B phase, the smectic D phase, the smectic phase E phase, the smectic F phase, the smectic G phase, the smectic H phase, the smectic phase I phase, and the smectic phase J phase The smectic K phase and the smectic L phase, and more preferably the smectic B phase, the smectic F phase, and the smectic phase I phase. A polarizing layer with a higher degree of alignment can be X-ray wound A Bulgault peak from a hexagonal phase or a crystalline high-order structure is obtained in the ray measurement. The so-called "Bulegg crest" refers to the peak of the periodic structure of the surface from the molecular alignment, preferably a polarizing layer with a periodic interval of 3.0 to 5.0 Å.

The polymerizable liquid crystal (B) showing the smectic phase is referred to as a polymerizable smectic liquid crystal compound. The polymerizable smectic liquid crystal compound is a compound represented by the formula (B) (hereinafter sometimes 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 the 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; wherein X ¹ , at least one of X ² and X ³ is a 1,4-phenylene group which may have a substituent; -CH ₂ - which constitutes a cyclohexane-1,4-diyl group may be -O-, -S- Or -NR-substituted; R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group; Y ¹ and Y ² independently of each other represent -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, single a bond, -N=N-, -CR ^a =CR ^b -, -C≡C- or CR ^a =N-; R ^a and R ^b independently of each other represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; U ¹ Represents a hydrogen atom or a polymerizable group; U ² represents a polymerizable group; W ¹ and W ² independently represent a single bond, -O-, -S-, -COO- or OCOO-; and V ¹ and V ² independently represent each other; Alkanediyl having 1 to 20 carbon atoms having a substituent, and -CH ₂ - constituting the alkanediyl group may be substituted by -O-, -S- or NH-]

It is preferred that at least two of X ¹ , X ² and X ³ are a 1,4-phenylene group which may have a substituent.

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

Examples of the substituent which the 1,4-phenylene group which may have a substituent or the cyclohexane-1,4-diyl which may have a substituent may have a carbon number of a methyl group, an ethyl group, a butyl group, etc. ~4 alkane Base, cyano and halogen atoms.

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, and is preferably a polymerizable group. It is preferred that both U ¹ and U ² are polymerizable groups, and both of them are preferably photopolymerizable groups. The "photopolymerizable group" means a group which can participate 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 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 acryloxy group, a methacryloxy group, and an oxirane group. Oxetane. Among them, an acryloxy group, a methacryloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloxy group is more preferred.

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

The substituent which the alkanediyl group has may be a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted and linear alkanediyl group.

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

The compound (B) includes a compound represented by the formula (B-1) to the formula (B-25). When the compound (B) is a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

Preferably, it is selected from the group consisting of formula (B-2), formula (B-3), formula (B-4), formula (B-5), and formula (B-6), formula (B-7), formula (B-8), formula (B-13), formula (B-14), formula (B-15), formula (B-16) and formula ( B-17) At least one of the group consisting of the compounds represented.

The polymerizable liquid crystals (B) exemplified may be used singly or in combination. In the case where two or more kinds of polymerizable liquid crystals are combined, at least one of them is a polymerizable liquid crystal (B), and more preferably two or more types are polymerizable liquid crystals (B). By using them in combination, the liquid crystallinity may be maintained for a while even at a temperature lower than the liquid crystal-crystalline phase transition temperature. The mixing ratio in the case of combining two kinds of polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50.

The polymerizable liquid crystal (B) can be produced, for example, by a known method disclosed in Lub et al. Recl. TraV. Chim. Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

The content ratio of the polymerizable liquid crystal (B) in the composition B is preferably from 70 to 99.9% by mass, more preferably from 80 to 99.9% by mass, based on the solid content of the composition. When the content ratio of the polymerizable liquid crystal (B) is within the above range, the alignment property of the polymerizable liquid crystal (B) tends to be high. Here, the "solid content component" means the total amount of components of the volatile component such as a solvent removed from the composition B.

The content of the dichroic dye in the composition B can be appropriately adjusted according to the type of the dichroic dye, etc., and is preferably 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal (B). It is preferably 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 10 parts by mass or less. When the content of the dichroic dye is within this range, the polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal (B). When the content of the dichroic dye is too large, the alignment of the polymerizable liquid crystal (B) is hindered.

Composition B preferably contains a solvent. Since the viscosity of the smectic liquid crystal compound is generally high, the composition containing a solvent is easily applied, and as a result, formation of a polarizing film is likely to be easy. The solvent is the same as the solvent contained in the above-mentioned alignment polymer composition, and can be appropriately selected depending on the solubility of the polymerizable liquid crystal (B) and the dichroic dye.

The content of the solvent is preferably from 50 to 98% by mass based on the total amount of the composition B. In other words, the solid content in the composition B is preferably from 2 to 50% by mass.

Composition A and/or Composition B preferably contains more than one leveling agent. The leveling agent has a function of adjusting the fluidity of the composition B and making the coating film obtained by coating the composition B flatter, and specifically, a surfactant. The leveling agent is preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a compound containing a fluorine atom as a main component.

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

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

When the composition A and/or the composition B contains a leveling agent, the content thereof is preferably 0.05 parts by mass or more and 5 parts by mass or less, more preferably 0.05 parts by mass or more, based on 100 parts by mass of the polymerizable liquid crystal. 3 parts by mass or less. If the content of the leveling agent is within the above range, then There is a tendency that the polymerizable liquid crystal is easily aligned horizontally and the obtained polarizing layer becomes smoother. When the content of the leveling agent with respect to the polymerizable liquid crystal is within the above range, the obtained polarizing layer tends to be less likely to be uneven.

Composition A and/or Composition B preferably contains more than one polymerization initiator. The polymerization initiator is preferably a photopolymerization initiator in terms of starting a polymerization reaction of the polymerizable liquid crystal (B) at a lower temperature. Specific examples thereof include a photopolymerization initiator which can generate an active radical or an acid by the action of light. Among them, a photopolymerization initiator which generates a radical by the action of light is preferred.

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

As the benzoin compound, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether can be mentioned.

Examples of the benzophenone compound include benzophenone, methyl ortho-benzoylbenzoate, 4-phenylbenzophenone, and 4-benzylidene-4'-methyldiphenyl sulfide. 3,3',4,4'-tetra(t-butylcarbonyl)benzophenone and 2,4,6-trimethylbenzophenone.

As the phenylalkyl ketone compound, diethoxyacetophenone and 2-methyl-2- can be mentioned. Lolinyl-1-(4-methylthienyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4- Polinylphenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane- 1-ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2- An oligomer of methyl-1-[4-(1-methylphenyl)phenyl]propan-1-one.

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

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

A polymerization initiator can be used by a commercial one. As a commercially available polymerization initiator, "Irgacure (registered trademark) 907", "Irgacure (registered trademark) 184", "Irgacure (registered trademark) 651", "Irgacure (registered trademark) 819", "Irgacure" (registered trademark) 250", "Irgacure (registered trademark) 369" (Ciba Japan); "Seikuol (registered trademark) BZ", "Seikuol (registered trademark) Z", "Seikuol (registered trademark) BEE" ( Seiko Chemical Co., Ltd.; "kayacure (registered trademark) BP 100" (Nippon Chemical Co., Ltd.); "kayacure (registered trademark) UVI-6992" (manufactured by Dow); "ADEKA Optomer SP-152", " ADEKA Optomer SP-170" ("ADEKA"); "TAZ-A", "TAZ-PP" (Nihon Siber Hegner); 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 depending on the kind and amount of the polymerizable liquid crystal contained in the composition, and is 100 parts by mass based on the polymerizable liquid crystal. It is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. When the content of the polymerizable initiator is within this range, the polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal (B).

In the case where the composition A and/or the composition B contains a photopolymerization initiator, the composition may further contain a photosensitizer. As the photosensitizer, there can be mentioned: oxalyl ketone, 9-oxygen sulphide Isotonic ketone compound (eg 2,4-diethyl-9-oxosulfide) 2-isopropyl-9-oxosulfur Anthracene, an alkoxy-containing anthracene (eg, dibutoxyanthracene, etc.); And red fluorene.

When the composition A and/or the composition B contains a photopolymerization initiator and a photosensitizer, the polymerization reaction of the polymerizable liquid crystal contained in the composition can be further promoted. Photosensitizer The amount of the photopolymerization initiator and the amount of the polymerizable liquid crystal and the amount thereof can be appropriately adjusted, and it is 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. More preferably 0.5 to 8 parts by mass.

In order to carry out the polymerization reaction of the polymerizable liquid crystal more stably, the composition A and/or the composition B may contain an appropriate amount of the polymerization inhibitor, whereby the degree of progress of the polymerization reaction of the polymerizable liquid crystal can be easily controlled.

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

In the case where the composition A and/or the composition B contains a polymerization inhibitor, the content thereof can be appropriately adjusted depending on the kind and amount of the polymerizable liquid crystal, the amount of the photosensitizer used, and the like, and is 100 parts by mass based on the polymerizable liquid crystal. It is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. When the content of the polymerization inhibitor is within this range, the polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal.

The polarizing layer is usually formed by applying the composition B onto a substrate, an alignment film or a retardation layer to polymerize the polymerizable liquid crystal (B) in the obtained coating film. The method of applying the composition is not limited. The alignment film may be the same as the above.

In the coating composition B, the solvent is dried and removed under the condition that the polymerizable liquid crystal (B) contained in the obtained coating film is not polymerized, thereby forming a dried film. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. When the polymerizable liquid crystal (B) is a polymerizable smectic liquid crystal compound, it is preferred that the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dried film is a nematic phase (nematic liquid crystal state). After that, it is transferred to the smectic phase. In order to form a smectic phase via a nematic phase, for example, a method of heating and drying the coating to a temperature at which a polymerizable smectic liquid crystal compound phase contained in the dried film is transferred to a liquid crystal state of a nematic phase may be employed, and then Cooling to a polymeric layer The liquid crystal compound displays the temperature of the liquid crystal state of the layer phase.

Next, a method of photopolymerizing the polymerizable liquid crystal (B) in a liquid crystal state in which the layer phase of the layer is maintained after the liquid crystal state of the polymerizable liquid crystal (B) in the dried film is a smectic phase will be described. In the photopolymerization, the light to be irradiated to the dried film may be based on the type of the photopolymerization initiator contained in the dried film or the type of the polymerizable liquid crystal (B) (especially the polymerizable liquid crystal (B). The type of the photopolymerizable group and the amount thereof are appropriately selected, and specific examples thereof include light or an active electron beam selected from the group consisting of visible light, ultraviolet light, and laser light. Among these, ultraviolet light is preferred in terms of easy control of the progress of the polymerization reaction or use as a photopolymerization device in a wide range of users in the field. Therefore, it is preferred to preliminarily select the type of the polymerizable liquid crystal (B) or the photopolymerization initiator contained in the composition B by photopolymerization by ultraviolet light. Further, at the time of polymerization, the polymerization temperature may be controlled by light irradiation while cooling the dried film by an appropriate cooling means. When the polymerization of the polymerizable liquid crystal (B) is carried out at a lower temperature by using such a cooling mechanism, the polarizing layer can be appropriately formed even if a substrate having low heat resistance is used. In the photopolymerization, the patterned polarizing layer can also be obtained by masking or developing.

By photopolymerization, the polymerizable liquid crystal (B) is polymerized in a liquid crystal state in which the smectic phase is maintained, preferably in the high-order smectic phase, to form a polarizing layer. The polarizing layer obtained by polymerizing the polymerizable liquid crystal (B) in a liquid crystal state in which the layer phase is maintained is accompanied by the action of the dichroic dye, and the polarizing film of the liquid crystal state containing the nematic phase of the previous guest-type polarizing film. Compared, it has the advantage of higher polarization performance. Further, it has an advantage of being excellent in strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

The retardation axis of the phase difference layer and the absorption axis of the polarizing layer in the circular polarizing plate may be parallel to each other or may be straight. In order to exhibit a good function as a circularly polarizing plate, the angle formed by the retardation axis of the retardation layer and the absorption axis of the polarizing layer is preferably substantially 45°.

In the case of manufacturing the circular polarizing plate, the order of forming the retardation layer and the polarizing layer is Any order. After the retardation layer is formed on the substrate, a polarizing layer is formed on the retardation layer. After the polarizing layer is formed on the substrate, a retardation layer is formed on the polarizing layer. A polarizing layer may be formed on one side of the substrate, and a retardation layer may be formed on the other side of the substrate. An alignment film may also 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 retardation layer is formed on a substrate and a polarizing layer is formed on the retardation layer, 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 also be formed on the protective layer to form a polarizing layer thereon. Further, after the polarizing layer is formed on the substrate, a protective layer is formed on the polarizing layer, and a retardation layer is formed thereon. An alignment film may also be formed on the protective layer to form a phase difference layer thereon.

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

The solvent contained in the composition for forming a protective layer may be the same as the above solvent, and at least one solvent selected from the group consisting of water, an alcohol solvent and an ether solvent does not dissolve the layer forming the protective layer. In terms of aspects, it is better. 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, preferred are ethanol, isopropanol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate.

The thickness of the protective layer is usually 20 μm or less. The thickness of the protective layer is preferably 0.5 μm or more and 9.5 μm or less, and more preferably 1 μm or more and 5 μm or less. The thickness of the protective layer can usually be determined by measurement using an interference film thickness meter, a laser microscope or a stylus film thickness meter.

The circular polarizing plate can form a phase difference layer or a polarizing layer on the surface of the circular polarizing plate. The surface in turn has an adhesive layer. Further, an undercoat layer may be provided between the retardation layer or the polarizing layer and the adhesive layer.

The adhesive layer is formed from a self-adhesive agent, and the adhesive usually contains a polymer and may also contain a solvent.

Examples of the polymer include an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyether, and the like. Among them, the acrylic-based pressure-sensitive adhesive containing an acrylic polymer is excellent in optical transparency, maintains moderate wettability, cohesive force, and excellent adhesion, and further has high weather resistance and heat resistance, and is heated or It is preferable that the peeling problem such as bulging or peeling is hard to occur under the conditions of humidification.

The acrylic polymer is preferably a (meth) acrylate having an alkyl group having a carbon number of 20 or less, such as a methyl group, an ethyl group or a butyl group (hereinafter, an acrylate or a methacrylic acid is sometimes used). The esters are collectively referred to as (meth)acrylic acid esters, and the acrylic acid and methacrylic acid are collectively referred to as (meth)acrylic acid) and (meth)acrylic acid or (meth)acrylic acid hydroxyethyl ester and the like having a functional group (meth)acrylic acid. a copolymer of monomers.

The adhesive containing such a copolymer is excellent in adhesion, and it is preferable since it is bonded to a display device and does not cause a paste residue on the display device during peeling, and can be easily peeled off. The glass transition temperature of the acrylic polymer is preferably 25 ° C or lower, more preferably 0 ° C or lower. The weight average molecular weight of such an acrylic polymer is preferably 100,000 or more.

Examples of the solvent include a solvent exemplified as a solvent of the above-mentioned alignment polymer composition.

Further, the adhesive may also contain a light diffusing agent. The light diffusing agent is used to impart light diffusing property to the adhesive layer, and may be a fine particle having a refractive index different from that of the polymer contained in the adhesive layer. Examples of the light diffusing agent include fine particles containing an inorganic compound. Or a microparticle containing an organic compound (polymer). The base polymer comprising the above-mentioned acrylic polymer constituting the adhesive layer exhibits a refractive index of about 1.4, and thus acts as light diffusion. The agent may be appropriately selected from the group having a refractive index of about 1 to 2. The refractive index difference between the polymer contained in the adhesive as an active ingredient and the light diffusing agent is usually 0.01 or more, and from the viewpoint of brightness and visibility of the liquid crystal display device, it is preferably 0.01 or more and 0.5 or less. The fine particles used as the light diffusing agent are preferably spherical and close to monodisperse. For example, fine particles having an average particle diameter in the range of about 2 to 6 μm can be preferably used.

The refractive index can be measured by a usual minimum declination method or an Abbe refractometer.

Examples of the fine particles containing the inorganic compound include alumina (refractive index of 1.76) and cerium oxide (refractive index of 1.45).

Further, examples of the fine particles containing the organic compound (polymer) include melamine beads (refractive index of 1.57), polymethylmethacrylate beads (refractive index of 1.49), and methyl methacrylate/styrene copolymer. Resin beads (refractive index 1.50~1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refraction) Rate 1.46) and polyoxyxene beads (refractive index 1.46).

The amount of the light diffusing agent can be appropriately determined in consideration of the haze value required for the adhesive layer to be dispersed or the brightness of the liquid crystal display device to which it is applied, and is usually 3 to 30 parts by weight with respect to 100 parts by weight of the resin constituting the adhesive layer. About the weight.

The fog value of the adhesive layer dispersed by the light diffusing agent is preferably set to 20~ from the viewpoint of ensuring the brightness of the liquid crystal display device using the circular polarizing plate having the adhesive layer and displaying the image as being less likely to cause flaws or blurring. 80% range. The value represented by the haze value (diffuse transmittance / total light transmittance) × 100 (%) was measured in accordance with JIS K 7105.

The thickness of the pressure-sensitive adhesive layer is not particularly limited as long as it is determined according to the adhesion force or the like, and is usually about 1 to 40 μm. In order to obtain a circularly polarizing plate having a thin adhesive layer without impairing properties such as workability and durability, the thickness of the adhesive layer is preferably about 3 to 25 μm. Further, by setting the thickness of the adhesive layer to about 3 to 25 μm, it is possible to maintain the brightness when the liquid crystal display device is viewed from the front or when viewed from the oblique direction, and the display image is less likely to be bounced or blurred.

The undercoat layer is usually formed of a transparent resin solution, which is a transparent resin. The undercoat layer can suppress defects of the retardation layer or the polarizing layer when the adhesive layer is formed. The transparent resin is preferably excellent in coatability and excellent in transparency and adhesion after formation of the undercoat layer.

According to the transparent solubility, the solvent of the transparent resin solution may be an aromatic hydrocarbon solvent such as benzene, toluene or xylene; a ketone solvent such as acetone, methyl ethyl ketone or methyl isobutyl ketone; ethyl acetate or acetic acid; An ester solvent such as isobutyl ester; a chlorinated hydrocarbon solvent such as dichloromethane, trichloroethylene or chloroform; or an organic solvent such as an alcohol solvent such as ethanol, 1-propanol, 2-propanol or 1-butanol, but if used When the transparent resin solution containing an organic solvent forms an undercoat layer, the optical characteristics of the liquid crystal cured film may be affected. Therefore, it is preferred to form a primer layer using a solution using water as a solvent.

An epoxy resin is mentioned as said transparent resin. The epoxy resin may be a one-liquid hardening type or a two-liquid hardening type. It is especially preferred as a water soluble epoxy resin. The water-soluble epoxy resin may, for example, be a polyamine obtained by reacting a polyalkyleneamine such as diethyltriamine or tris-ethyltetramine with a dicarboxylic acid such as adipic acid. Polyamine, a polyamide resin obtained by reacting with epichlorohydrin. As a commercial item of the polyamine epoxy resin, "Sumirez Resin (registered trademark) 650 (30)" or "Sumirez Resin (registered trademark) 675" (registered trademark) sold by Sumika Chemtex Co., Ltd. Wait.

When a water-soluble epoxy resin is used as the transparent resin, in order to improve coatability, it is preferred to use another water-soluble resin such as a polyvinyl alcohol-based resin in combination. The polyvinyl alcohol-based resin may be, for example, partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, ethyl acetylated modified polyvinyl alcohol, hydroxymethyl-modified polyvinyl alcohol, amine-based modified A modified polyvinyl alcohol-based resin of polyvinyl alcohol. A commercially available product of a polyvinyl alcohol-based resin, such as "KL-318" (trade name) which is an anionic group-containing polyvinyl alcohol sold by Kuraray Co., Ltd., may be mentioned.

In the case where the undercoat layer is formed from 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. Again, in When the polyvinyl alcohol-based resin is blended in the solution, the amount thereof is preferably about 1 to 6 parts by weight based on 100 parts by weight of water. The thickness of the undercoat layer is preferably in the range of about 0.1 to 10 μm.

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

The adhesive layer can be formed by applying the above-mentioned adhesive to the surface of the retardation layer, the polarizing layer or the undercoat layer and drying it, or by releasing the film by the release treatment. After applying an adhesive on the surface and drying to form an adhesive layer, the film with the adhesive layer is attached to the retardation layer, the polarizing layer or the undercoat layer in such a manner that the adhesive layer side becomes a bonding surface. Formed by the method of the surface. It is preferred to subject the surface of the undercoat layer forming the adhesive layer to a corona discharge treatment in advance. Thereby, the adhesion between the undercoat layer and the adhesive layer can be further improved.

Examples of the method of applying the pressure-sensitive adhesive include the same methods as those exemplified as the method of applying the alignment polymer composition to the substrate. The method of removing the solvent from the applied adhesive agent is, for example, the same method as the method of removing the solvent from the self-aligning polymer composition.

The peeling strength of the present circular polarizing plate having an adhesive layer on the surface can be measured by the following manner.

A test piece having a width of 25 mm and a length of about 200 mm is cut from the circular polarizing plate having an adhesive layer on the surface, and the adhesive surface is attached to the glass plate, and then the tensile tester is used to sandwich the longitudinal direction of the test piece. One end (one side of 25 mm wide), at a temperature of 23 ° C and a relative humidity of 60%, at a crosshead speed (clamp moving speed) of 200 mm/min, according to JIS K 6854-1:1999 "Adhesive-peeling density" The 90° peel test of the strength test method - Part 1: 90 degree peeling.

Substituting substrate, first alignment film, polarizing layer, second alignment film, retardation layer And the peeling strength (F1) of the substrate and the first alignment film in the circular polarizing plate of the adhesive layer is preferably lower than the peeling strength (F2) of the first alignment film and the polarizing layer, and the phase difference between the second alignment film and the second alignment film The peel strength (F3) of the layer and the peel strength (F4) of the retardation layer and the adhesive layer. The peel strength (F1) can be adjusted by the substrate and the first alignment film.

For example, in a substrate having a functional group that forms a chemical bond with an alignment film on the surface, the peel strength (F1) of the substrate and the first alignment film tends to be high. Therefore, as the substrate which lowers the peel strength (F1), a substrate having a small number of functional groups on the surface is preferable, and a substrate which is not subjected to surface treatment for forming a functional group on the surface is preferable.

Further, the alignment film having a functional group that forms a chemical bond with the substrate tends to have a higher peel strength (F1) between the substrate and the first alignment film. Therefore, as an alignment film which lowers the peeling strength (F1), it is preferable that the alignment film which forms a chemical bond with a base material is few. Further, in order to lower (F1), it is preferred that the alignment polymer composition or the photo-alignment film-forming composition does not contain a reagent for crosslinking the substrate and the alignment film, and further preferably does not contain a dissolution substrate. The solvent and other ingredients. When the surface of the substrate is dissolved by the composition for forming the alignment polymer composition or the photo-alignment film, the peel strength (F1) of the substrate and the first alignment film tends to increase.

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

A circular polarizing film having an adhesive layer is obtained by removing the substrate from a circular polarizing plate having an adhesive layer on the surface. As a method of removing a base material, any method is mentioned.

The thickness of the circularly polarizing film having an adhesive layer is usually 5 μm or more and 15 μm or less, preferably 5 μm or more and 10 μm or less. The thickness of the circularly polarizing film having the adhesive layer can be generally determined by measurement using an interference film thickness meter, a laser microscope or a stylus type film thickness meter.

Next, a method of continuously manufacturing the present circular polarizing plate will be described. As a preferred method for continuously producing a circularly polarizing plate, a method in the form of a Roll to Roll can be cited.

Specifically, a method of sequentially performing the following steps: (1) preparing a step of winding a substrate around a roll of a core, (2) a step of 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, and continuously forming a retardation layer (5) a step of continuously forming a protective layer on the retardation layer of the roll obtained in the above (4), and (6) a step of applying an alignment film on the protective layer obtained in the above (5), and continuously forming, ( 7) a step of coating the composition B on the alignment film obtained in the above (6), continuously forming a polarizing layer, and (8) on the polarizing layer obtained in the above (7), the adhesive layer side is a bonding surface In the same manner, the step of bonding the film with the adhesive layer is attached, and (9) the step of winding the continuously obtained circular polarizing plate on the second core to obtain the second roll.

Furthermore, steps (5) and (8) may be omitted as needed.

Further, a method of sequentially performing the steps of: (1a) preparing a substrate for winding a roll of a core, (2a) for continuously feeding the substrate from the roll, and (3a) for the substrate may be mentioned. a step of continuously forming an alignment film, (4a) coating composition B on the alignment film, continuously forming a polarizing layer, and (5a) continuously forming a protective layer on the polarizing layer of the roller obtained in the above (4a) a step of (6a) coating an alignment film on the protective layer obtained in the above (5a), forming a continuous process, and (7a) coating the composition A on the alignment film obtained in the above (6a) to continuously form a phase difference In the step of layer, (8a) is carried out on the retardation layer obtained in the above (7a), and the step of bonding the film with the adhesive layer is carried out in such a manner that the adhesive layer side becomes a bonding surface, and (9a) is continuously obtained. The circular polarizing plate is wound around the second core to obtain the second roller.

Furthermore, steps (5a) and (8a) may be omitted as needed.

Further, a method of sequentially performing the steps of: (1b) preparing a substrate for winding a roll of a core, (2b) for continuously feeding the substrate from the roll, and (3b) for the substrate may be mentioned. a step of continuously forming an alignment film, (4b) coating the composition A on the alignment film, and continuously forming a phase difference layer, (5b) opposite to the phase difference layer of the roller obtained in the above (4b) a step of applying an alignment film thereon, continuously forming, (6b) coating the composition B on the alignment film obtained in the above (5b), continuously forming a polarizing film, and (7b) winding the circular polarizing plate continuously obtained On the second core, the step of obtaining the second roll is obtained.

Further, a method of sequentially performing the steps of: (1c) preparing a transparent substrate wound around a roll of a core, (2c) a step of continuously feeding the transparent substrate from the roll, and (3c) a step of continuously forming an alignment film on a transparent substrate, (4c) applying a composition containing the composition B on the alignment film, continuously forming a polarizing layer, and (5c) a roll obtained in the above (4c) a step of continuously forming an alignment film on the opposite surface of the polarizing layer, (6c) a step of coating the composition A on the alignment film obtained in the above (5c), continuously forming a phase difference layer, and (7c) continuously obtaining circularly polarized light. The step of winding the sheet on the second core to obtain the second roll.

Fig. 1 is a schematic view showing the circular polarizing plate. Fig. 1(a) is a circularly polarizing plate laminated in the order of a substrate, a retardation layer, and a polarizing layer. Figure 1 (b) is a substrate, a polarizing layer, and a phase difference layer A circular polarizing plate laminated in sequence.

The circular polarizing plate can be used for various display devices. Further, a circularly polarizing plate having an adhesive layer on its surface can be used for the manufacture of various display devices. Specifically, a circular polarizing plate having an adhesive layer on the surface thereof is attached to the display surface of the display device via the adhesive layer, thereby obtaining a display device including the circular polarizing plate, and further removing the substrate. A display device with a circularly polarizing film having the circularly polarizing film of the present invention was obtained.

A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL, electroluminescence) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, and an electron emission display device (for example, a field emission display device (FED, Field Emission Display), surface conduction electron emission display (SED, Surface-conduction Electron-emitter Display), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg gate) a light valve imaging system (GLV, Grating Light Valve) display device, a display device having a digital micro mirror device (DMD, Digital Micro-mirror device), a piezoelectric ceramic display, etc. The liquid crystal display device includes a transmissive liquid crystal display device Any of a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, an intuitive liquid crystal display device, and a projection type liquid crystal display device. The display device may be a display device for displaying a two-dimensional image, or A stereoscopic display device for displaying a three-dimensional image, which can be used particularly effectively for an organic electroluminescent (EL) display device or an inorganic electro-optic (EL) Shown in the display means.

Fig. 2 is a schematic view showing a liquid crystal display device 10 which is one of the display devices of the present invention. The liquid crystal layer 15 is sandwiched 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 disposed at a position opposed to the pixel electrode 20 via the liquid crystal layer 15, and the black matrix 18 is disposed at a position facing the boundary between the pixel electrodes. The transparent electrode 14 is covered with the same. A protective layer is provided between the color filter 13 and the transparent electrode 14.

The thin film transistor 19 and the pixel electrode 20 are arranged regularly 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 via 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.

Examples of the substrate 12a and the substrate 12b include a glass substrate and a plastic substrate. In the case where the color filter 13 or the thin film transistor 19 formed on the substrate is to be heated at a high temperature, the substrate 12a and the substrate 12b are preferably glass substrates.

Examples of the thin film transistor 19 include a high-temperature polycrystalline germanium transistor formed on a quartz substrate, a low-temperature polycrystalline germanium transistor formed on a glass substrate, and an amorphous germanium transistor formed on a glass substrate or a plastic substrate. In order to achieve miniaturization 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. In order to keep the distance between the substrate 12a and the substrate 12b fixed, the spacer 21 can be formed in the liquid crystal layer 15. An alignment film for aligning the liquid crystal compound contained in the liquid crystal layer 15 in a desired direction may be disposed on the surface of the layer formed on the substrate 12a and the substrate 12b in contact with the liquid crystal layer 15.

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

The circular polarizing plate 11a and the central polarizing plate 11b are laminated on the outer side of the substrate 12a and the substrate 12b sandwiching the liquid crystal layer 15. A backlight unit 17 as a light source is disposed outside the local 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 the light source, various light sources such as an electroluminescence (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.

Fig. 3 is a schematic view 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. 3(a) is provided with a circular polarizing plate 31. On the substrate 32 on which the pixel electrode 34 is formed via the interlayer insulating film 33, the light-emitting layer 35 and the cathode electrode 36 are laminated. The circular polarizing plate 31 is disposed on the opposite side of the substrate 32 from the light-emitting layer 35. By applying a positive voltage to the pixel electrode 34, a negative voltage is applied to the cathode electrode 36, and a direct current is applied between the pixel electrode 34 and the cathode electrode 36 to cause the light-emitting layer 35 to emit light. The light emitting layer 35 includes an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the light-emitting layer 35 passes through the pixel electrode 34, the interlayer insulating film 33, the substrate 32, and the present circular polarizing plate 31.

In order to manufacture the organic EL display device 30, a thin film transistor 38 is first formed on the substrate 32 in a desired shape. Further, the interlayer insulating film 33 is formed into a film, and then the pixel electrode 34 is formed into a film by sputtering to pattern it. Thereafter, the light-emitting layer 35 is laminated.

Then, the circular polarizing plate 31 is provided on the opposite surface of the substrate 32 from the surface on which the thin film transistor 38 is disposed. In this case, the 1/4 wavelength layer of the circular polarizing plate 31 is disposed on the substrate 32 side.

Examples of the substrate 32 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate, a ceramic substrate such as alumina, a metal substrate such as copper, and a plastic substrate. A thermally conductive film may be formed on the substrate 32, but is not shown. Examples of the thermally conductive film include a diamond thin film (DLC, Diamond like carbon, etc.). When the pixel electrode 34 is of a reflective type, the light is directed in the opposite direction to the substrate 32. Therefore, not only a transparent material but also a non-penetrating material such as stainless steel can be used. The substrate may be formed singly, or a plurality of substrates may be bonded to each other to form a laminated substrate. Moreover, these substrates are not limited to a plate shape, and may be a film.

As the thin film transistor 38, for example, a polycrystalline germanium transistor or the like may be used. The thin film transistor 38 is provided at the end of the pixel electrode 34 and has a size of about 10 to 30 μm. Further, the size of the pixel electrode 34 is 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 to a low level. Generally, the wiring electrode can be made of Al, Al, and a transition metal (excluding Ti), Ti or nitride. Any one or more of titanium (TiN).

An interlayer insulating film 33 is provided between the thin film transistor 38 and the pixel electrode 34. In the interlayer insulating film 33, an inorganic material such as cerium oxide or tantalum nitride such as SiO ₂ is formed by sputtering or vacuum deposition, and cerium oxide formed by SOG (spin-on-glass) is used. Any one of the coating film of a resin material such as a photoresist, a polyimide, an acrylic resin, or an acrylic resin may have any insulating property.

A barrier wall 39 is formed on the interlayer insulating film 33. The barrier rib 39 is disposed at a peripheral portion of the pixel electrode 34 (between adjacent pixels). Examples of the material of the barrier rib 39 include an acrylic resin and a polyimide resin. The thickness of the barrier rib 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, an EL element including 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 layer of a hole transport layer and a light-emitting layer, for example, an electron injection transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer.

Examples of the pixel electrode 34 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO _{2 ,} and In ₂ O ₃ , and more preferably ITO or IZO. The thickness of the pixel electrode 35 may be a thickness equal to or more than a predetermined size sufficient for hole injection, and is preferably 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 or Xe or a mixed gas thereof can be used.

As a constituent material of the cathode electrode 36, for example, a metal element such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn or Zr may be used, in order to improve the action of the electrode. For stability, it is preferred to use an alloy system selected from two or three of the exemplified metal elements. As the alloy system, for example, 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: 5~20at%) and so on.

The cathode electrode 36 can be formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 36 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

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

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

As the light-emitting layer 35, those who emit light (fluorescence) from singlet excitons, those who use light from triplet excitons (phosphorescence), those that use self-single-state excitons (fluorescence), and the like can be used. Materials for light-emitting (phosphorescence) of triplet excitons, materials formed by organic substances, materials including those formed by organic substances and those formed by inorganic substances, polymer materials, low molecular materials, those containing polymer materials and low molecular materials, etc. . However, the light-emitting layer 35 using various materials known as EL elements can be used in the organic EL display device 30.

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

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

[Examples]

Hereinafter, the present invention will be described in further detail by way of examples. In the examples, "%" and "parts" are used to indicate the mass % and mass parts.

Example 1 [Preparation of Composition for Forming Phase Difference Layer]

The following components were mixed, and the resulting mixture was stirred at 80 ° C for 1 hour to obtain a composition for forming a retardation layer.

The compound A1 and the compound A2 are synthesized by the method disclosed in Japanese Laid-Open Patent Publication No. 2010-31223.

Compound A1 (80 parts):

Compound A2 (20 parts):

Polymerization initiator (6 parts): 2-dimethylamino-2-benzyl-1-(4- Phenylphenyl)butan-1-one

(Irgacure 369; Ciba 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 Photoalignment Film Formation]

The following components were mixed, and the resulting mixture was stirred at 80 ° C for 1 hour to obtain a composition for forming a photo-alignment film.

Light aligning material (5 parts):

Solvent (95 parts): cyclopentanone

[Preparation of Composition for Polarizing Layer Formation]

The following components were mixed, and the resulting mixture was stirred at 80 ° C for 1 hour to obtain a composition for forming a polarizing layer. Compound B1 and Compound B2 were synthesized by the method disclosed 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: 2-dimethylamino-2-benzyl-1-(4- Phenylphenyl)butan-1-one

(Irgacure369; manufactured by Ciba Specialty Chemicals Co., Ltd.) 6 copies

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

Solvent: cyclopentanone 250 parts

[Measurement of phase transition temperature]

The obtained composition for forming a polarizing layer was applied onto a glass and dried to prepare a sample for measurement. When the phase transition temperature was confirmed by texture observation by a polarizing microscope, the temperature was raised to 140 ° C, and when the temperature was lowered, the phase transition to the nematic phase was confirmed at 108 ° C, and the phase was confirmed at 101 ° C. The phase transition of the layer A phase confirmed the phase transition to the layer B phase at 76 °C.

[Preparation of a composition for forming an adhesive]

The following components were mixed at 55 ° C in a nitrogen atmosphere to obtain an acrylic resin.

70 parts of butyl acrylate

20 parts of methyl acrylate

Acrylic acid 1.0 part

Starting agent: azobisisobutyronitrile 0.2 parts

Solvent (80 parts): ethyl acetate

Further, Coronate L (75% ethyl acetate solution of toluene diisocyanate trimethylolpropane adduct, 3 isocyanate groups in 1 molecule, manufactured by Japan Polyurethane Industry Co., Ltd.), 0.5 part of decane coupling agent In the case of 0.5 parts of X-12-981 (manufactured by Shin-Etsu Silicones Co., Ltd.), ethyl acetate was added as a composition for forming an adhesive, so that the total solid content concentration was 10%. Using the applicator, the obtained adhesive-forming composition was applied to a release-treated polyethylene terephthalate film (manufactured by Lintec Co., Ltd.) for release treatment so that the thickness after drying became 10 μm. The surface was dried at 100 ° C for 1 minute to obtain a film (1) with an adhesive.

[Manufacture of circular polarizer]

1. Formation of alignment film for polarizing layer

KC4UY (TAC film, manufactured by Konica Minolta Co., Ltd.) as a cellulose film was used as a transparent substrate film. The photo-alignment film-forming composition was applied onto the film by a bar coating method, and dried by heating in a drying oven at 60 ° C for 1 minute. The obtained dried film was subjected to a polarized UV irradiation treatment to form a first alignment film. The polarized UV treatment was carried out under the conditions of a density of 100 mJ measured at a wavelength of 365 nm using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO Co., Ltd.). Further, the polarization direction of the polarized UV is performed with respect to the retardation axis of the phase difference layer of 0°.

2. Formation of polarizing layer

The composition for forming a polarizing layer was applied onto the formed first alignment film by a bar coating method, and dried by heating in a drying oven at 120 ° C for 1 minute, and then cooled to room temperature. The dried film was irradiated with ultraviolet rays at a exposure amount of 1200 mJ/cm ² (365 nm basis) using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO Co., Ltd.), thereby forming a polarizing layer. The thickness of the obtained polarizing layer was measured by a laser microscope (OLS 3000 manufactured by Olympus Co., Ltd.), and it was 1.8 μm.

3. Formation of protective layer

By coating the polarizing layer by bar coating method, 50 parts of dipentaerythritol hexaacrylate (manufactured by ARONIX M-403 East Asia Synthetic Co., Ltd.) and acrylate resin (limited by Ebecryl 4858 Daicel-UCB) Made by the company) 50 parts and 2-methyl-1[4-(methylthio)phenyl]-2- 3 parts of a solution prepared by dissolving 250 parts of isopropyl alcohol (protective layer-forming composition), which is dissolved in 250 parts of isopropanol, and dried by heating in a drying oven at 50 ° C. 1 minute. The obtained dried film was irradiated with ultraviolet rays at a exposure amount of 400 mJ/cm ² (365 nm basis) using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO Co., Ltd.) to form a protective layer on the polarizing layer.

4. Formation of alignment film for phase difference layer

The photo-alignment film-forming composition was applied onto the formed protective layer by a bar coating method, and dried by heating in a drying oven at 60 ° C for 1 minute. The obtained dried film was subjected to a polarized UV irradiation treatment to form a second alignment film. The polarized UV treatment was carried out under the conditions of a density of 100 mJ measured at a wavelength of 365 nm using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO Co., Ltd.). Further, the polarization direction of the polarized UV was performed at 45° with respect to the absorption axis of the polarizing layer.

5. Formation of phase difference layer

The phase difference layer forming composition was applied onto the formed second alignment film by a bar coating method, and dried by heating in a drying oven at 120 ° C for 1 minute, and then cooled to room temperature. The obtained dried film was irradiated with ultraviolet rays having an exposure amount of 1000 mJ/cm ² (365 nm basis) using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO Co., Ltd.) to form a retardation layer. The thickness of the obtained phase difference layer was measured by a laser microscope (OLS 3000 manufactured by Olympus Co., Ltd.), and it was 2.0 μm.

In this way, a wide-band circular polarizer can be produced. The total thickness of the circularly polarizing plate was measured by a contact type film thickness meter and found to be 45 μm.

[Evaluation of circular polarizer]

X-ray diffraction measurement

The obtained polarizing layer was subjected to X-ray diffraction measurement by an X-ray diffraction apparatus X'Pert PRO MPD (manufactured by Spectris Co., Ltd.). The X-ray generated by using Cu as a target at an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV is self-friction direction via a fixed divergence slit 1/2° (predetermined in the rubbing direction of the alignment film under the polarizing layer) The incidence was measured by scanning in the range of 2θ=0.01 to 40.0° in the scanning range 2θ=4.0~40.0°. As a result, a steep diffraction peak of a full width at half maximum (FWHM) = about 0.29 ° was obtained in the vicinity of 2θ = 20.12 °. Further, the same result was obtained in the case where X-rays were incident from the rubbing perpendicular direction. The order period (d) obtained from the peak position is about 4.4 Å, and it is known that a structure reflecting the columnar phase of the high-order layer is formed.

2. Determination of reflectivity

In order to confirm the usefulness of the circularly polarizing plate, the reflectance was measured in the following manner. A measurement sample was prepared by laminating a phase difference layer of a circularly polarizing plate made of an adhesive and a reflecting plate (mirror aluminum plate).

Using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation), light having a wavelength in the range of 400 to 700 nm was incident on the measurement sample at a range of 12° from the normal direction in a step of 2 nm, and the reflectance of the reflected light was measured. When the reflectance when the non-bonded circularly polarizing plate is placed only on the reflecting plate and is measured by 100%, and the reflectance is calculated, the reflectance of light having a wavelength in the range of 400 to 700 nm is about 1 to 10%, and it is known that visible light is visible. Full anti-reflection properties are obtained throughout the region.

Example 2

In the same manner as in Example 1, a first alignment film was formed on one surface of the transparent substrate film (the polarization direction of the polarized UV was 45° with respect to the long side of the substrate film) on the photoalignment film. A phase difference layer is formed. After the protective layer is formed on the retardation layer, a second alignment film is formed (the polarization direction of the polarized UV is 0° with respect to the long side of the base film), and a polarizing layer is formed on the optical alignment film to form a circularly polarizing plate.

In the same manner as in the first embodiment, the transparent base film and the reflecting plate of the circularly polarizing plate produced by the adhesive were bonded together, and the reflectance was measured. As a result, the reflectance of the light having a wavelength in the range of 400 to 700 nm was 1 to 10 About %, it is known that sufficient anti-reflection characteristics are obtained for the entire visible light region.

Example 3

In addition to the use of the compound (B-14) in place of the compound (B-6) as the polymerizable liquid crystal compound B1, and the use of the compound (B-17) in place of the compound (B-7) as the polymerizable liquid crystal compound B2, and Example 1 In the same manner, a circular polarizing plate was produced.

In the same manner as in the first embodiment, the phase difference layer and the reflecting plate of the circularly polarizing plate produced by using an adhesive were measured for reflectance, and as a result, the reflectance of light having a wavelength in the range of 400 to 700 nm was about 1 to 10%. It can be seen that sufficient anti-reflection properties are obtained for the entire visible light region.

Comparative example 1

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

In the same manner as in the first embodiment, the produced circular polarizing plate was bonded to the reflecting plate by using an adhesive, and the reflectance was measured. As a result, the reflectance of light having a wavelength of 500 to 600 nm was about 1 to 10%. However, the reflectance of light having a wavelength of 400 to 500 nm and the reflectance of light having a wavelength of 600 to 700 nm are 10% or more, and the reflected light is blue-violet, and it is understood that a sufficient anti-reflection function is not obtained.

Comparative example 2

An iodine-PVA polarizing plate (supplied by Sumikalan Sumitomo Chemical Co., Ltd., thickness: 105 μm) was cut into a 100 × 100 mm piece as a polarizing plate so that the absorption axis became 0°. The 1/2 wavelength plate used in Example 1 was cut into pieces of 100 × 100 mm so that the slow phase axis became 15°. The quarter-wave plate used in Comparative Example 1 was cut into pieces of 100 × 100 mm so that the slow phase axis became 15°. An acrylic adhesive (film thickness: 25 μm) was used, and each of the cut films was bonded to each other by a polarizing plate + a quarter-wave plate + a 1/2 wavelength plate to prepare a circularly polarizing plate.

In the same manner as in the first embodiment, the prepared polarizing plate was bonded to a reflecting plate by an adhesive to measure the reflectance, and as a result, the reflectance of light having a wavelength in the range of 400 to 700 nm was about 1 to 10%. The anti-reflection property was obtained in all of the visible light, 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 produced in the same manner as in Example 1 except that a polyethylene terephthalate film was used instead of KC4UY (TAC film, manufactured by Konica Minolta Co., Ltd.) as a cellulose film. A film (1) with an adhesive is attached to the retardation layer of the circular polarizing plate to obtain a circularly polarizing plate having an adhesive layer. The sample was cut to a size of 40 mm × 40 mm, and the film to which the adhesive film was attached was peeled off, pressed against a reflecting plate (mirror aluminum plate), and the substrate was slowly removed, thereby obtaining a circular polarizing film. Reflector. The thickness of the above circular polarizing film including the first alignment film, the polarizing layer, the protective layer, the second alignment film, the retardation layer, and the adhesive layer was 14.7 μm.

The peel strength (F1) of the substrate and the first alignment film is lower than the peel strength (F2) of the first alignment film and the polarizing layer, the peel strength (F3) of the second alignment film and the retardation layer, and the phase difference layer and the adhesive Since the peel strength (F4) of the layer is such that peeling occurs between the substrate and the first alignment film to remove the substrate.

The reflectance was measured in the same manner as in Example 1. As a result, the reflectance of light having a wavelength in the range of 400 to 700 nm was about 1 to 10%, and it was found that sufficient antireflection characteristics were obtained for the entire visible light region. This anti-reflection principle is the same as the external light reflection in the metal electrode of the organic EL display, and thus can be equally preferably used for an organic EL display.

[Industrial availability]

The circularly polarizing plate of the present invention has sufficient performance as a wide-band circularly polarizing plate, and the thickness thereof can also satisfy the thinning of the display device, and the manufacturing steps thereof are also simple. Moreover, the display device including the circularly polarizing plate of the present invention can be made thinner.

1‧‧‧The circular polarizer

2‧‧‧Substrate

3‧‧‧ phase difference layer

4‧‧‧ polarizing layer

5‧‧‧ dichroic pigment

Claims (19)

A circular polarizing plate comprising: a substrate, a retardation layer, and a polarizing layer, wherein the birefringence Δn(λ) of the retardation layer for light having a wavelength of λ nm satisfies the formulas (1) and (2), The retardation layer and the polarizing layer are both coating layers, and the total thickness of the retardation layer and the polarizing layer is 10 μm or less. The polarizing layer contains a dichroic dye, and the polarizing layer is polymerized by polymerizing one or more kinds of polymerizable liquid crystals. Formed, and the retardation layer is formed by polymerizing one or more polymerizable liquid crystals, Δn (450) / Δn (550) ≦ 1.00 (1) 1.00 ≦ Δn (650) / Δn (550) (2). The circularly polarizing plate of claim 1, wherein the polymerizable liquid crystal is polymerized by light irradiation. The circular polarizing plate of claim 1, wherein the polarizing layer is obtained by obtaining a polarizing layer of a Böhler wave peak in an X-ray diffraction measurement. The circular polarizing plate of claim 1, wherein the thickness of the phase difference layer and the polarizing layer are respectively 5 μm or less. The circular polarizing plate of claim 1, wherein the phase difference layer, the polarizing layer or both are formed on the alignment film. The circular polarizing plate of claim 5, wherein the alignment film is an alignment film that generates an alignment restricting force by light irradiation. The circular polarizing plate of claim 5, wherein the thickness of the alignment film is 500 nm or less. The circularly polarizing plate of claim 1, wherein the retardation layer is formed on the substrate with or without the alignment film, and the polarizing layer is formed on the retardation layer with or without the alignment film. The circularly polarizing plate of claim 1, wherein the polarizing layer is formed on the substrate with or without the alignment film, and the retardation layer is formed on the polarizing layer with or without the alignment film. The circular polarizing plate of claim 8 or 9, wherein a protective layer is included between the polarizing layer and the phase difference layer. The circular polarizing plate of claim 1, wherein the polarizing layer is formed on one side of the substrate with or without the alignment film, and the retardation layer is formed on the other side of the substrate with or without the alignment film. The circular polarizing plate of claim 1, wherein the surface of the phase difference layer or the polarizing layer further comprises an adhesive layer. The circular polarizing plate of claim 12, wherein the substrate, the first alignment film, the polarizing layer, the second alignment film, the phase difference layer and the adhesive layer are sequentially included. The circular polarizing plate of claim 13, wherein the peeling strength (F1) of the substrate and the first alignment film is lower than the peeling strength (F2) of the first alignment film and the polarizing layer, and the peeling strength of the second alignment film and the retardation layer (F3) and the peel strength (F4) of the retardation layer and the adhesive layer. A display device comprising the circularly polarizing plate and the display element according to any one of claims 1 to 14. A display device with a circularly polarizing film, which is obtained by removing a substrate from a circularly polarizing plate according to any one of claims 12 to 14, and a circular polarizing film is attached to the display via an adhesive layer of the circular polarizing film. The display surface of the component is the result. The display device of claim 16, wherein the thickness of the circularly polarizing film is 5 μm or more and 15 μm or less. The display device according to any one of claims 15 to 17, wherein the display element is a liquid crystal cell, an organic electroluminescence element or a touch panel. A manufacturing method of a display device with a circularly polarizing film, which is characterized in that the circularly polarizing plate according to any one of claims 12 to 14 is attached to the display surface of the display element via an adhesive layer of the circular polarizing plate, and The substrate is removed from the circular polarizing plate.