JP6123563B2 - Circularly polarizing plate and display device - Google Patents

Description

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

  There is known a liquid crystal display device including a broadband circularly polarizing plate in which a polarizing film made of polyvinyl alcohol dyed with iodine, a half-wave plate and a quarter-wave plate are laminated. In such a broadband circularly polarizing plate, the angle formed between the slow axis of the half-wave plate and the absorption axis of the polarizing film and the angle formed between the slow axis of the quarter-wave plate and the absorption axis of the polarizing film are 15 respectively. Since it is necessary to laminate the film by shifting by ° or 75 °, it is difficult to produce the circularly polarizing plate by roll-to-roll bonding. On the other hand, there has been a strong demand for thin display devices, and for this reason, circular polarizing plates are also required to be thin.

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

JP 2006-337892 A JP 2009-251288 A

  However, the circularly polarizing plate described in Patent Document 1 is sufficiently satisfactory in terms of the simplicity of the manufacturing process and the thickness of the circularly polarizing plate because two films are laminated via an adhesive or an adhesive. I didn't get it. The circularly polarizing plate described in Patent Document 2 has insufficient performance as a broadband circularly polarizing plate because the retardation layer exhibits positive wavelength dispersion.

The present invention includes the following inventions.
[1] A substrate, a retardation layer, and a polarizing layer, wherein the birefringence Δn (λ) of the retardation layer with respect to light having a wavelength of λnm satisfies the expressions (1) and (2) A circularly polarizing plate, wherein both the layer and the polarizing layer are coating layers, 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 according to [1], wherein the retardation layer is formed by polymerizing one or more polymerizable liquid crystals.
[3] The circularly polarizing plate according to [1] or [2], wherein the polarizing layer is formed by polymerizing one or more polymerizable liquid crystals.
[4] The circularly polarizing plate according to [2] or [3], wherein the polymerizable liquid crystal is polymerized by light irradiation.
[5] The circularly polarizing plate according to any one of [1] to [4], wherein the polarizing layer is a polarizing layer from which a Bragg peak is obtained in X-ray diffraction measurement.
[6] The circularly polarizing plate according to any one of [1] to [5], wherein each of the retardation layer and the polarizing layer has a thickness of 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 circularly polarizing plate according to [7], wherein the alignment film is an alignment film in which an alignment regulating force is generated by light irradiation.
[9] The circularly polarizing plate according to [7] or [8], wherein the alignment film has a thickness of 500 nm or less.
[10] A retardation layer is formed on a substrate with or without an alignment film, and a polarizing layer is formed on the retardation layer with or without an alignment film [1]. -The circularly-polarizing plate in any one of [9].
[11] A polarizing layer is formed on a substrate with or without an alignment film, and a retardation layer is formed on the polarizing layer with or without an alignment film. [9] The circularly polarizing plate according to any one of [9].
[12] The circularly polarizing plate according to [10] or [11], which has a protective layer between the polarizing layer and the retardation layer.
[13] A polarizing layer is formed on one surface of the substrate with or without an alignment film, and a retardation layer is formed on the other surface of the substrate with or without an alignment film. The circularly polarizing plate according to any one of [1] to [9].
[14] The circularly polarizing plate according to any one of [1] to [13], further having an adhesive layer on the surface of the retardation layer or polarizing layer.
[15] The circularly polarizing plate according to [14], which includes a base material, a first alignment film, a polarizing layer, a second alignment film, a retardation layer, and an adhesive layer in this order.
[16] The peel strength (F1) between the substrate and the first alignment film is the peel strength (F2) between the first alignment film and the polarizing layer, and the peel strength between the second alignment film and the retardation layer ( The circularly polarizing plate according to [15], which is lower than F3) and the peel strength (F4) between the retardation layer and the pressure-sensitive adhesive layer.
[17] A display device comprising the circularly polarizing plate according to any one of [1] to [16] and a display element.
[18] A circularly polarizing film from which the base material has been removed from the circularly polarizing plate according to any one of [14] to [16] is bonded to the display surface of the display element via the adhesive layer of the circularly polarizing film. Display device with circularly polarized film.
[19] The display device according to [18], wherein the circularly polarizing film has a thickness of 5 μm or more and 15 μm or less.
[20] The display device according to any one of [17] to [19], wherein the display element is a liquid crystal cell, an organic electroluminescence element, or a touch panel.
[21] The circularly polarizing plate according to any one of [14] to [16] is bonded to the display surface of the display element via the pressure-sensitive adhesive layer of the circularly polarizing plate, and the substrate is removed from the circularly polarizing plate. A method of manufacturing a display device with a circularly polarizing film to be removed.

  According to the present invention, a thin and broadband circularly polarizing plate and a display device including the circularly polarizing plate can be provided.

It is a cross-sectional schematic diagram of the circularly-polarizing plate of this invention. It is a schematic diagram of the liquid crystal display device containing the circularly-polarizing plate of this invention. It is a schematic diagram of the organic electroluminescence display containing the circularly-polarizing plate of this invention.

  The substrate is usually a transparent substrate. When the substrate of the circularly polarizing plate of the present invention (hereinafter sometimes referred to as the present circularly polarizing plate) is not installed on the display surface of the display element, for example, a circularly polarizing film obtained by removing the substrate from the circularly polarizing plate is used. When installing on the display surface of a display element, a base material does not need to be transparent. The transparent substrate means a substrate having transparency capable of transmitting light, particularly visible light, and the transparency is a characteristic that the transmittance with respect to a light beam having a wavelength of 380 to 780 nm is 80% or more. Say. Specific examples of the transparent substrate include a translucent resin substrate. Examples of the resin constituting the translucent resin base material include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate esters; polyacrylate esters; Examples thereof include cellulose esters such as diacetylcellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of easy availability and transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin or polycarbonate is preferred.

  Cellulose ester is obtained by esterifying a part or all of hydroxyl groups contained in cellulose, and can be easily obtained from the market. Cellulose ester base materials can also be easily obtained from the market. Examples of commercially available cellulose ester base materials include “Fujitack Film” (Fuji Photo Film Co., Ltd.); “KC8UX2M”, “KC8UY” and “KC4UY” (Konica Minolta Opto Co., Ltd.).

  Cyclic olefin resin is easily available from the market. Commercially available cyclic olefin resins include “Topas” [Ticona (Germany)], “Arton” [JSR Corporation], “ZEONOR” [Nippon Zeon Corporation], and “ZEONEX”. [Nippon Zeon Co., Ltd.] and “Apel” [Mitsui Chemicals Co., Ltd.]. Such a cyclic olefin-based resin can be formed into a substrate by forming a film by a known means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin base material marketed can also be used. Commercially available cyclic olefin resin base materials include “Essina” [Sekisui Chemical Co., Ltd.], “SCA40” [Sekisui Chemical Co., Ltd.], “Zeonor Film” [Optes Co., Ltd.], and “Arton Film”. [JSR Corporation].

  When the cyclic olefin-based resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the content ratio of the structural unit derived from the cyclic olefin is the total structural unit of the copolymer. On the other hand, it is usually 50 mol% or less, preferably 15 to 50 mol%. Examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene, and alkyl-substituted styrene. When the cyclic olefin-based 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 that of the copolymer. The content 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, and the content of the structural unit derived from the aromatic compound having a vinyl group is usually 5 to 80 mol%. It is. Such a terpolymer has the advantage that the amount of expensive cyclic olefin used can be relatively reduced in its production.

  Although the characteristics required for the substrate vary depending on the configuration of the circularly polarizing plate, a substrate having as small a retardation as possible is usually preferable. Examples of the base material having as little retardation as possible include cellulose ester films having no phase difference such as zero tack (Konica Minolta Opto Co., Ltd.), Z tack (Fuji Film Co., Ltd.), and the like. Further, an unstretched cyclic olefin resin substrate is also preferable.

  In the case of a circularly polarizing plate in which a polarizing layer is formed on a substrate with or without an alignment film, and a retardation layer is formed on the polarizing layer with or without an alignment film, A hard coat treatment, an antireflection treatment, an antistatic treatment or the like may be performed on the surface of the base material on which no layer is formed. In addition, the hard coat layer may contain additives such as an ultraviolet absorber as long as the performance is not affected.

  If the thickness of the substrate is too thin, the strength tends to decrease and the workability tends to be inferior, so it is usually 5 to 300 μm, preferably 20 to 200 μm.

The retardation layer is a coating layer having a birefringence index Δn (λ) with respect to light having a wavelength of λ nm that satisfies the expressions (1) and (2). A coating layer is a layer formed by application | coating.
Δn (450) / Δn (550) ≦ 1.00 (1)
1.00 ≦ Δn (650) / Δn (550) (2)

  The birefringence Δn (λ) can be obtained by measuring retardation and dividing by the thickness of the retardation layer. Although the specific measuring method is shown in the Examples, in this case, by measuring a film formed on a base material such as a glass substrate that has no retardation in the base material itself, a substantial retardation layer can be measured. Characteristics can be measured.

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

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

  Of these, thermotropic nematic liquid crystals are preferable from the viewpoint of film formation, and the following formula (A) is used from the viewpoint of imparting the retardation represented by the formula (1) and the formula (2). (Hereinafter, sometimes referred to as compound (A)) is preferred. The polymerizable liquid crystal may be used alone or in combination.

［式（Ａ）中、
Ｘ^１は、酸素原子、硫黄原子またはＮＲ^１−を表わす。Ｒ^１は、水素原子または炭素数１〜４のアルキル基を表わす。
Ｙ^１は、置換基を有していてもよい炭素数６〜１２の１価の芳香族炭化水素基または置換基を有していてもよい炭素数３〜１２の１価の芳香族複素環式基を表わす。
Ｑ^３およびＱ^４は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜２０の１価の脂肪族炭化水素基、炭素数３〜２０の１価の脂環式炭化水素基、置換基を有していてもよい炭素数６〜２０の１価の芳香族炭化水素基、ハロゲン原子、シアノ基、ニトロ基、−ＮＲ^２Ｒ^３または−ＳＲ^２を表わすか、または、Ｑ^３とＱ^４とが互いに結合して、これらが結合する炭素原子とともに芳香環または芳香族複素環を形成する。Ｒ^２およびＲ^３は、それぞれ独立に、水素原子または炭素数１〜６のアルキル基を表わす。
Ｄ^１およびＤ^２は、それぞれ独立に、単結合、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｓ）−Ｏ−、−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−ＣＲ^６Ｒ^７−、−Ｏ−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−Ｏ−ＣＲ^６Ｒ^７−、−ＣＯ−Ｏ−ＣＲ^４Ｒ^５−、−Ｏ−ＣＯ−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−Ｏ−ＣＯ−ＣＲ^６Ｒ^７−、−ＣＲ^４Ｒ^５−ＣＯ−Ｏ−ＣＲ^６Ｒ^７−またはＮＲ^４−ＣＲ^５Ｒ^６−またはＣＯ−ＮＲ^４−を表わす。
Ｒ^４、Ｒ^５、Ｒ^６およびＲ^７は、それぞれ独立に、水素原子、フッ素原子または炭素数１〜４のアルキル基を表わす。
Ｇ^１およびＧ^２は、それぞれ独立に、炭素数５〜８の２価の脂環式炭化水素基を表わし、該脂環式炭化水素基を構成するメチレン基は、酸素原子、硫黄原子またはＮＨ−に置き換っていてもよく、該脂環式炭化水素基を構成するメチン基は、第三級窒素原子に置き換っていてもよい。
Ｌ^１およびＬ^２は、それぞれ独立に、１価の有機基を表わし、Ｌ^１およびＬ^２のうちの少なくとも一つは、重合性基を有する。］

[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.
Y ¹ is an optionally substituted monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms or an optionally substituted monovalent aromatic heterocyclic ring having 3 to 12 carbon atoms. Represents a formula group.
Q ³ and Q ⁴ are each independently a hydrogen atom, an optionally substituted monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent alicyclic group having 3 to 20 carbon atoms. A hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, a halogen atom, a cyano group, a nitro group, —NR ² R ³ or —SR ² ; Alternatively, Q ³ and Q ⁴ are bonded to each other to form an aromatic ring or an aromatic heterocyclic ring together with the carbon atom to which they are bonded. R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
D ¹ and D ² are each independently a single bond, —C (═O) —O—, —C (═S) —O—, —CR ⁴ R ⁵ —, —CR ⁴ R ⁵ —CR ⁶ R ^{7 -, - O-CR 4} R 5 -, - CR 4 R 5 -O-CR 6 R 7 -, - CO-O-CR 4 R 5 -, - O-CO-CR 4 R 5 -, - CR ^{4 R 5 -O-CO-CR} 6 R 7 -, - CR 4 R 5 -CO-O-CR 6 R 7 - or ^NR 4 ^-CR 5 ^{R 6} - or CO-NR ⁴ - represents a.
R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.
G ¹ and G ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, a sulfur atom or NH The methine group constituting the alicyclic hydrocarbon group may be replaced 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. ]

L ¹ in the compound (A) is preferably a group represented by the formula (A1), and L ² is preferably a group represented by the formula (A2).
P ¹ -F ^1- (B ¹ -A ¹ ) _k -E ^1- (A1)
P ² -F ^2- (B ² -A ² ) ₁ -E ^2- (A2)
[In Formula (A1) and Formula (A2),
^{B 1,} B 2, ^{E 1} and ^{E 2} are, each _{^{independently, -CR 4 R 5 -, -}} CH 2 -CH 2 -, - O -, - S -, - CO-O -, - O-CO It represents —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 a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon The methylene group constituting the group may be replaced by an oxygen atom, a sulfur atom or NH-, and the methine group constituting the alicyclic hydrocarbon group is replaced by a tertiary nitrogen atom. Also good.
k and l each independently represents an integer of 0 to 3.
F ¹ and F ² represent a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms.
P ¹ represents a polymerizable group.
P ² represents a hydrogen atom or a polymerizable group.
R ⁴ and R ⁵ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms. ]

  Preferred examples of the compound (A) include compounds described in JP-T-2011-207765.

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

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

The alignment film in the present invention has an alignment regulating force that aligns the polymerizable liquid crystal in a desired direction.
As the alignment film, a film having a solvent resistance that does not dissolve by application of a composition containing a polymerizable liquid crystal, and a heat resistance in heat treatment for removing the solvent or aligning the polymerizable liquid crystal is preferable. Examples of the alignment film include an alignment film containing an alignment polymer and a photo-alignment film.

  Examples of the orientation polymer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule and hydrolyzates thereof, polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, Examples include polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. Two or more orientation polymers may be used in combination.

  The alignment film containing the alignment polymer is usually applied to a substrate with a composition in which the alignment polymer is dissolved in a solvent (hereinafter sometimes referred to as an alignment polymer composition), and the solvent is removed or alignment. It is obtained by applying a functional polymer composition to a substrate, removing the solvent, and rubbing (rubbing method).

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

  The concentration of the orienting polymer in the orienting polymer composition may be within a range in which the orienting polymer material can be completely dissolved in the solvent, but is preferably 0.1 to 20% in terms of solid content with respect to the solution. More preferably, it is about 1 to 10%.

  A commercially available alignment film material may be used as it is as the alignment polymer composition. Examples of commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optmer (registered trademark, manufactured by JSR).

  Examples of methods for applying the alignment polymer composition to the substrate include spin coating methods, extrusion methods, gravure coating methods, die coating methods, bar coating methods, applicator methods and other printing methods, flexographic methods, and other printing methods. Known methods such as When this circularly polarizing plate is produced by a roll to roll type continuous production method described later, a printing method such as a gravure coating method, a die coating method, or a flexo method is usually employed as the coating method.

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

  In order to impart alignment regulating force to the alignment film, rubbing can be performed as necessary (rubbing method).

  As a method for imparting alignment regulating force by the rubbing method, a rubbing cloth was wound, and the orientation polymer composition was applied to the rotating rubbing roll and annealed and formed on the substrate surface. The method of making the film | membrane of an orientation polymer contact is mentioned.

  The photo-alignment film is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter sometimes referred to as “photo-alignment film-forming composition”) to a substrate, and polarizing ( Preferably, it is obtained by irradiation with polarized UV). The photo-alignment film is more preferable in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

  The photoreactive group refers to a group that generates liquid crystal alignment ability when irradiated with light. Specific examples include groups involved in photoreactions that are the origin of liquid crystal alignment ability such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction or photodecomposition reaction caused by light irradiation. Among them, a group involved in the dimerization reaction or the photocrosslinking reaction is preferable in terms of excellent orientation. As the photoreactive group, an unsaturated bond, particularly a group having a double bond is preferable, and a carbon-carbon double bond (C═C bond), a carbon-nitrogen double bond (C═N bond), or a nitrogen-nitrogen two bond. A group having at least one selected from the group consisting of a heavy bond (N═N bond) and a carbon-oxygen double bond (C═O bond) is particularly preferred.

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

  Among them, a photoreactive group involved in the photodimerization reaction is preferable, the amount of polarized light irradiation necessary for photoalignment is relatively small, and a photoalignment film excellent in thermal stability and temporal stability can be easily obtained. A cinnamoyl group and a chalcone group are preferred. As the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

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

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

  Examples of the method for applying the composition for forming a photo-alignment film to a substrate include the same methods as the method for applying the alignment polymer composition to a substrate. Examples of the method for removing the solvent from the applied composition for forming a photo-alignment film include the same method as the method for removing the solvent from the oriented polymer composition.

  In order to irradiate polarized light, it is possible to irradiate polarized light from the substrate side and transmit the polarized light even in the form of irradiating polarized UV directly to the composition from which the solvent is removed from the composition for forming a photo-alignment film applied on the substrate. It is also possible to irradiate. The polarized light is particularly 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 polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferable. Examples of the light source used for the polarized irradiation include xenon lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and the like. High pressure mercury lamps, ultra high pressure mercury lamps and metal halides. A lamp is more preferred. These lamps are preferable because of high emission intensity of ultraviolet rays having a wavelength of 313 nm. By irradiating light from the light source through an appropriate polarizer, polarized UV light can be irradiated. As such a polarizer, a polarizing prism such as a polarizing filter, Glan-Thompson, or Granteller, or a wire grid type polarizer can be used.

  Note that a plurality of regions (patterns) having different liquid crystal alignment directions can be formed by performing masking during rubbing or polarized light irradiation.

  The thickness of the alignment film (alignment film containing alignment polymer and photoalignment 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. It is in the range of 10 nm to 100 nm.

  The composition containing one or more polymerizable liquid crystals (A) used for forming the retardation layer (hereinafter sometimes referred to as “composition A”) usually contains a solvent. The thing similar to the solvent contained in a polymer composition is mentioned, According to the solubility of polymeric liquid crystal (A), it can select suitably.

  The application of the composition A is usually performed by a known method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, an applicator method, or a printing method such as a flexo method. Is done by. After the application, a dry film is usually formed by removing the solvent under conditions where the polymerizable liquid crystal (A) contained in the obtained coating film is not polymerized. Examples of the drying method include natural drying, ventilation drying, heat drying, and reduced pressure drying.

  Polymerization of the polymerizable liquid crystal (A) can be performed by a known method for polymerizing a compound having a polymerizable functional group. Specific examples include thermal polymerization and photopolymerization, and photopolymerization is preferred from the viewpoint of ease of polymerization. When the polymerizable liquid crystal (A) is polymerized by photopolymerization, the polymerizable liquid crystal (A) in the dry film obtained by applying and drying the composition A containing the photopolymerization initiator is brought into a liquid crystal phase state, It is preferable to carry out photopolymerization while maintaining the liquid crystal state.

  Photopolymerization is usually carried out by irradiating the dry film with light. As the light to be irradiated, depending on the type of photopolymerization initiator contained in the dry film, the type of polymerizable liquid crystal (A) (particularly the type of photopolymerizable group possessed by the polymerizable liquid crystal (A)) and the amount thereof, Specific examples include light selected from the group consisting of visible light, ultraviolet light, and laser light, and active electron beams. Among them, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that a photopolymerization apparatus widely used in this field can be used, so that photopolymerization can be performed by ultraviolet light. It is preferable to select the type of the polymerizable liquid crystal (A) and the photopolymerization initiator. Further, at the time of polymerization, the polymerization temperature can be controlled by irradiating light while cooling the dry film by an appropriate cooling means. By employing such a cooling means, if the polymerizable liquid crystal (A) is polymerized at a lower temperature, the retardation layer can be appropriately formed even if the substrate has a relatively low heat resistance. During the photopolymerization, a patterned retardation layer can be obtained by masking or developing.

  In this circularly polarizing plate, the total thickness of the retardation layer and the polarizing layer 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 from 0.5 μm to 9.5 μm, and more preferably from 1 μm to 5 μm. The thickness of the retardation layer and the polarizing layer can be usually determined by measurement with an interference film thickness meter, a laser microscope or a stylus thickness meter.

  The polarizing layer contains a dichroic dye. The “dichroic dye” means a dye having a property that the absorbance in the major axis direction of the molecule is different from the absorbance in the minor axis direction. The dichroic dye is not limited as long as it has such properties, and may be a dye or a pigment. Two or more dyes may be used in combination, two or more pigments may be used in combination, or a dye and a pigment may be used in combination.

  The dichroic dye preferably has a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, and among them, azo dyes are preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, and a stilbene azo dye, and a bisazo dye and a trisazo dye are preferable.

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

  Examples of the monovalent heterocyclic group include groups in which one hydrogen atom has been removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. Examples of the divalent heterocyclic group include groups in which two hydrogen atoms have been removed from the heterocyclic compound.

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

［式（１−１）〜（１−６）中、
Ｂ^１〜Ｂ^２０は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜４のアルコキシ基、シアノ基、ニトロ基、置換または無置換のアミノ基（置換アミノ基および無置換アミノ基の定義は前記のとおり）、塩素原子またはトリフルオロメチル基を表わす。
ｎ１〜ｎ４は、互いに独立に０〜３の整数を表わす。
ｎ１が２以上である場合、複数のＢ^２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＢ^６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＢ^９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＢ¹⁴は互いに同一でも異なっていてもよい。］
Among the compounds (1), compounds represented by any of the following formulas (1-1) to (1-6) are preferable.

[In the formulas (1-1) to (1-6),
B ^{1 to} B ²⁰ each 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, a nitro group, a substituted or unsubstituted amino group (a substituted amino group and The definition of an unsubstituted amino group is as described above), and represents a chlorine atom or a trifluoromethyl group.
n1 to n4 each independently represents an integer of 0 to 3.
when n1 is 2 or more, the plurality of B ² may be the same as or different from each other;
when n2 is 2 or more, the plurality of B ⁶ may be the same as or different from each other;
when n3 is 2 or more, the plurality of B ⁹ may be the same as or different from each other;
When n4 is 2 or more, the plurality of B ¹⁴ may be the same as or different from each other. ]

［式（１−７）中、
Ｒ^１〜Ｒ^８は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１〜４のアルキル基または炭素数６〜１２のアリール基を表わす。］ As the anthraquinone dye, a compound represented by the formula (1-7) is preferable.

[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 an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（１−８）中、
Ｒ^９〜Ｒ^１５は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１〜４のアルキル基または炭素数６〜１２のアリール基を表わす。］ As the oxazone dye, a compound represented by the formula (1-8) is preferable.

[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 an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（１−９）中、
Ｒ^１６〜Ｒ^２３は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘまたはハロゲン原子を表わす。
Ｒ^ｘは、炭素数１〜４のアルキル基または炭素数６〜１２のアリール基を表わす。］
式（１−７）、式（１−８）および式（１−９）において、Ｒ^ｘの炭素数１〜６のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基およびヘキシル基が挙げられ、炭素数６〜１２のアリール基としては、フェニル基、トルイル基、キシリル基およびナフチル基が挙げられる。 As the acridine dye, a compound represented by the formula (1-9) is preferable.

[In 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, the -SR ^x, or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]
In formula (1-7), formula (1-8) and formula (1-9), the alkyl group having 1 to 6 carbon atoms of R ^x is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group. And a hexyl group, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

［式（１−１０）中、
Ｄ^１およびＤ^２は、互いに独立に、式（１−１０ａ）〜式（１−１０ｄ）のいずれかで表される基を表わす。

ｎ５は１〜３の整数を表わす。］

［式（２−１１）中、
Ｄ^３およびＤ^４は、互いに独立に、式（１−１１ａ）〜式（１−１１ｈ）のいずれかで表される基を表わす。

ｎ６は１〜３の整数を表わす。］ As the cyanine dye, a compound represented by the formula (1-10) and a compound represented by the formula (1-11) are preferable.

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

n5 represents an integer of 1 to 3. ]

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

n6 represents an integer of 1 to 3. ]

  The polarizing layer is a coating layer. The polarizing layer contains a composition (hereinafter referred to as composition) containing at least one polymerizable liquid crystal (hereinafter sometimes referred to as polymerizable liquid crystal (B)) that becomes a host compound in addition to the dichroic dye. It is preferably formed by coating 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 more preferably a higher order smectic phase in that a polarizing layer having a higher degree of alignment order can be produced. “High-order smectic phase” means smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase and smectic L phase. Of these, a smectic B phase, a smectic F phase, and a smectic I phase are more preferable. A polarizing layer having a high degree of orientational order can obtain a Bragg peak derived from a higher order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The “Bragg peak” means a peak derived from a plane periodic structure of molecular orientation, and a polarizing layer having a periodic interval of 3.0 to 5.0 mm is preferable.

The polymerizable liquid crystal (B) exhibiting a smectic phase is referred to as a polymerizable smectic liquid crystal compound. Examples of the polymerizable smectic liquid crystal compound include a compound represented by the formula (B) (hereinafter sometimes referred to as the 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. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. —CH ₂ — constituting the cyclohexane-1,4-diyl group may be replaced by —O—, —S— or —NR—. R represents a C1-C6 alkyl group or a phenyl group.
Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or CR ^a ═N— is represented. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
U ¹ represents a hydrogen atom or a polymerizable group.
U ² represents a polymerizable group.
W ¹ and W ² each independently represent a single bond, —O—, —S—, —COO— or OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or NH- may be substituted. ]

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

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

  As the substituent that the optionally substituted 1,4-phenylene group or optionally substituted cyclohexane-1,4-diyl group has, a methyl group, an ethyl group, C1-C4 alkyl groups, such as a butyl group, a cyano group, and a halogen atom are mentioned.

Y ¹ is preferably —CH ₂ CH ₂ —, —COO— or a single bond, and Y ² is preferably —CH ₂ CH ₂ — or CH ₂ O—.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, preferably a polymerizable group. U ¹ and U ² are preferably both polymerizable groups, and both are preferably photopolymerizable groups. The “photopolymerizable group” means a group that 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, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

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

  Examples of the substituent that the alkanediyl group optionally has include a cyano group and a halogen atom. The alkanediyl group is preferably unsubstituted, and is an unsubstituted and linear alkanediyl group. Is more preferable.

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

  Examples of the compound (B) include compounds represented by formula (B-1) to formula (B-25). When the compound (B) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

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

  The exemplified polymerizable liquid crystal (B) can be used alone or in combination. When two or more kinds of polymerizable liquid crystals are combined, at least one kind is preferably a polymerizable liquid crystal (B), and more preferably two or more kinds are a polymerizable liquid crystal (B). In combination, the liquid crystallinity may be temporarily maintained even at a temperature lower than the liquid crystal-crystal phase transition temperature. When mixing two kinds of polymerizable liquid crystal compounds, the mixing ratio is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50. It is.

  Polymerizable liquid crystal (B) can be prepared by, for example, Lub et al. Trav. Chim. It is manufactured by a known method described in Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

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

  The content of the dichroic dye in the composition B can be adjusted as appropriate according to the type of the dichroic dye, but is 0.1 to 50 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal (B). Or less, more preferably 0.1 part by mass or more and 20 parts by mass or less, and further preferably 0.1 part 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 performed without disturbing the orientation of the polymerizable liquid crystal (B). When there is too much content of a dichroic pigment | dye, there exists a possibility of inhibiting the orientation of polymeric liquid crystal (B).

  Composition B preferably contains a solvent. In general, a smectic liquid crystal compound has a high viscosity, so that a composition containing a solvent is easy to apply, and as a result, it is often easy to form a polarizing film. As a solvent, the thing similar to the solvent contained in the above-mentioned orientation polymer composition is mentioned, It can select suitably according to the solubility of polymeric liquid crystal (B) and a dichroic dye.

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

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

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

  Leveling agents mainly composed of fluorine atom-containing compounds include “Megafac (registered trademark) R-08”, “R-30”, “R-90”, “F-410”, and “F”. -411 "," F-443 "," F-445 "," F-470 "," F-471 "," F-477 "," F-479 "," F- 482 "and" F-483 "[DIC Corporation];" Surflon (registered trademark) S-381 "," S-382 "," S-383 "," S-393 "," "SC-101", "SC-105", "KH-40" and "SA-100" [AGC Seimi Chemical Co., Ltd.]; "E1830", "E5844" [Daikin Fine Chemical Laboratory Co., Ltd.]; F-top EF301 "," F-top EF303 "," F-top EF 51 "and" Eftop EF352 "[Mitsubishi Materials Electronic Chemicals Co., Ltd.] and the like.

  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 with respect to 100 parts by mass of the polymerizable liquid crystal, and 0.05 parts by mass. More preferred is 3 parts by mass or less. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal, and the obtained polarizing layer tends to be smoother. When the content of the leveling agent with respect to the polymerizable liquid crystal is within the above range, unevenness tends not to occur in the obtained polarizing layer.

  It is preferable that the composition A and / or the composition B contain one or more polymerization initiators. The polymerization initiator is a compound capable of initiating a polymerization reaction of the polymerizable liquid crystal (B), and a photopolymerization initiator is preferable in that the polymerization reaction can be initiated under a lower temperature condition. Specific examples include photopolymerization initiators that can generate active radicals or acids by the action of light. Among these, photopolymerization initiators that generate radicals by the action of light are preferred.

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

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

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

  Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane. -1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1- [ 4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propan-1-one An oligomer is mentioned.

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

  As triazine compounds, 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2 -(5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1,3 , 5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- [ - (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available thing can be used for a polymerization initiator. Commercially available polymerization initiators include “Irgacure (registered trademark) 907”, “Irgacure (registered trademark) 184”, “Irgacure (registered trademark) 651”, “Irgacure (registered trademark) 819”, “Irgacure (registered trademark)” "Registered Trademark) 250", "Irgacure (Registered Trademark) 369" (Ciba Japan Co., Ltd.); Seika Chemical Co., Ltd.); “Kayacure (registered trademark) BP100” (Nippon Kayaku Co., Ltd.); “Kayacure (registered trademark) UVI-6992” (manufactured by Dow); “Adekaoptomer SP-152 "Adekaoptomer SP-170" (ADEKA); "TAZ-A", "TAZ-PP" Siber Hegner Ltd.); and "TAZ-104" (Sanwa Chemical Co., Ltd.).

  When composition A and / or composition B contains a polymerization initiator, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal contained in the composition. 0.1-30 mass parts is preferable with respect to mass parts, 0.5-10 mass parts is more preferable, and 0.5-8 mass parts is still more preferable. When the content of the polymerizable initiator is within this range, the polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal (B).

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

  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 accelerated. The amount of the photosensitizer used can be appropriately adjusted according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal, and is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal. 0.5-10 mass parts is more preferable, and 0.5-8 mass parts is still more preferable.

  In order to allow the polymerization reaction of the polymerizable liquid crystal to proceed more stably, the composition A and / or the composition B may contain an appropriate amount of a polymerization inhibitor, whereby the degree of progress of the polymerization reaction of the polymerizable liquid crystal. It becomes easy to control.

  As polymerization inhibitors, radical scavengers such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, etc. Thiophenols; β-naphthylamines and β-naphthols.

  When the composition A and / or the composition B contains a polymerization inhibitor, the content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal and the amount of the photosensitizer used. 0.1-30 mass parts is preferable with respect to 100 mass parts of crystalline liquid crystal, 0.5-10 mass parts is more preferable, 0.5-8 mass parts is further more preferable. When the content of the polymerization inhibitor is within this range, the polymerization can be performed without disturbing the alignment of the polymerizable liquid crystal.

  A polarizing layer is normally formed by apply | coating the composition B on a base material, an oriented film, or a phase difference layer, and polymerizing the polymeric liquid crystal (B) in the obtained coating film. The method for applying the composition is not limited. Examples of the alignment film include the same ones as described above.

  The composition B is applied, and the solvent is dried and removed under the condition that the polymerizable liquid crystal (B) contained in the obtained coating film is not polymerized, whereby a dry film is formed. Examples of the drying method include natural drying, ventilation drying, heat drying, and reduced pressure drying. When the polymerizable liquid crystal (B) is a polymerizable smectic liquid crystal compound, the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dry film is preferably changed to a nematic phase (nematic liquid crystal state) and then transferred to the smectic phase. In order to form a smectic phase via a nematic phase, for example, the dry film is heated to a temperature above the temperature at which the polymerizable smectic liquid crystal compound contained in the dry film transitions to the liquid crystal state of the nematic phase, and then the polymerizable smectic. A method in which the liquid crystal compound is cooled to a temperature at which the liquid crystal state of the smectic phase is exhibited is employed.

  Next, a method for photopolymerizing the polymerizable liquid crystal (B) while maintaining the liquid crystal state of the smectic phase after the liquid crystal state of the polymerizable liquid crystal (B) in the dry film is changed to a smectic phase will be described. In the photopolymerization, the light applied to the dry film includes the type of photopolymerization initiator contained in the dry film, the type of the polymerizable liquid crystal (B) (in particular, the photopolymerization group of the polymerizable liquid crystal (B). Type) and the amount thereof are appropriately selected. Specific examples thereof include light selected from the group consisting of visible light, ultraviolet light, and laser light, and active electron beams. Among these, ultraviolet light is preferable in that the progress of the polymerization reaction can be easily controlled, and that a photopolymerization apparatus widely used in this field can be used. Therefore, it is preferable to select the kind of the polymerizable liquid crystal (B) and the photopolymerization initiator contained in the composition B so that the photopolymerization can be performed with ultraviolet light. Further, at the time of polymerization, the polymerization temperature can be controlled by irradiating light while cooling the dry film by an appropriate cooling means. If the polymerizable liquid crystal (B) is polymerized at a lower temperature by employing such a cooling means, a polarizing layer can be appropriately formed even if a substrate having a relatively low heat resistance is used. In the photopolymerization, a patterned polarizing layer can be obtained by masking or developing.

  By performing photopolymerization, the polymerizable liquid crystal (B) is polymerized while maintaining the liquid crystal state of a smectic phase, preferably a higher order smectic phase, and a polarizing layer is formed. A polarizing layer obtained by polymerizing the polymerizable liquid crystal (B) while maintaining a smectic phase liquid crystal state is a conventional host-guest type polarizing film, that is, a nematic phase liquid crystal due to the action of the dichroic dye. There is an advantage that the polarization performance is high as compared with the polarizing film made of a state. Furthermore, there is an advantage that it is excellent in strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

  In the present circularly polarizing plate, the slow axis of the retardation layer and the absorption axis of the polarizing layer are neither parallel to nor orthogonal. In order to exhibit a good function as a circularly polarizing plate, it is preferable that the angle formed by the slow axis of the retardation layer and the absorption axis of the polarizing layer is substantially 45 °.

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

  After forming the retardation layer on the substrate, when forming the polarizing layer on the retardation layer, if necessary, a protective layer is formed on the retardation layer, and the polarizing layer is formed on the protective layer. It may be formed. An alignment film may be formed on the protective layer, and a polarizing layer may be formed thereon. Moreover, after forming a polarizing layer in a base material, you may form a protective layer on a polarizing layer and may form a phase difference layer on it. An alignment film may be formed on the protective layer, and a retardation layer may be formed thereon.

  The protective layer is usually an acrylic oligomer or polymer comprising polyfunctional acrylate (methacrylate), urethane acrylate, polyester acrylate, epoxy acrylate, etc., polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl pyrrolidone, starches, methylcellulose, carboxy It is preferably formed from a composition for forming a protective layer containing a water-soluble polymer such as methyl cellulose and sodium alginate and a solvent.

  Examples of the solvent contained in the protective layer-forming composition include the same solvents as described above, and among them, at least one solvent selected from the group consisting of water, alcohol solvents and ether solvents forms the protective layer. This is preferable in that the layer is not dissolved. 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. Of these, ethanol, isopropyl alcohol, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferable.

  The thickness of the protective layer is usually 20 μm or less. 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 be usually determined by measurement using an interference film thickness meter, a laser microscope or a stylus thickness meter.

This circularly polarizing plate may further have a pressure-sensitive adhesive layer on the surface of the retardation layer or polarizing layer formed on the surface of the circularly polarizing plate. Moreover, you may have a primer layer between a phase difference layer or a polarizing layer, and an adhesive layer.
The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive, and the pressure-sensitive adhesive usually contains a polymer and may contain a solvent.

  Examples of the polymer include acrylic polymers, silicone polymers, polyesters, polyurethanes, and polyethers. Among them, acrylic pressure-sensitive adhesives containing acrylic polymers are excellent in optical transparency, maintain appropriate wettability and cohesion, have excellent adhesion, and have high weather resistance, heat resistance, etc. It is preferable because peeling problems such as floating and peeling are unlikely to occur under humidifying conditions.

Examples of the acrylic polymer include (meth) acrylates (hereinafter collectively referred to as (meth) acrylates) in which the alkyl group in the ester portion is an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, or a butyl group. Acrylate, acrylic acid and methacrylic acid are collectively referred to as (meth) acrylic acid.), And (meth) acrylic monomers having a functional group such as (meth) acrylic acid or hydroxyethyl (meth) acrylate; These copolymers are preferred.
The pressure-sensitive adhesive containing such a copolymer is excellent in adhesiveness, and it is relatively easy to cause no adhesive residue on the display device when it is peeled off after being bonded to the display device. Since it can peel, it is preferable. The glass transition temperature of the acrylic polymer is preferably 25 ° C. or lower, and more preferably 0 ° C. or lower. The weight average molecular weight of such an acrylic polymer is preferably 100,000 or more.

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

  The pressure-sensitive adhesive may contain a light diffusing agent. The light diffusing agent is for imparting light diffusibility to the pressure-sensitive adhesive layer, and may be fine particles having a refractive index different from that of the polymer contained in the pressure-sensitive adhesive layer. The light diffusing agent is made of an inorganic compound. Examples thereof include fine particles and fine particles composed of an organic compound (polymer). Since the base polymer constituting the pressure-sensitive adhesive layer including the acrylic polymer exhibits a refractive index of about 1.4, the light diffusing agent can be appropriately selected from those having a refractive index of about 1-2. Good. The refractive index difference between the polymer and the light diffusing agent contained as an active ingredient in the pressure-sensitive adhesive is usually 0.01 or more, and from the viewpoint of the brightness and visibility of the liquid crystal display device, 0.01 to 0.5. Is preferable. The fine particles used as the light diffusing agent are preferably spherical and those close to monodisperse. For example, fine particles having an average particle diameter in the range of about 2 to 6 μm are preferably used.

  The refractive index is measured by a general minimum deviation method or Abbe refractometer.

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

  Examples of the fine particles made of an organic compound (polymer) include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate / styrene copolymer resin beads (refractive index). 1.50), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46) ) And silicone resin beads (refractive index 1.46).

  The blending amount of the light diffusing agent is appropriately determined in consideration of the haze value required for the pressure-sensitive adhesive layer in which it is dispersed, the brightness of the liquid crystal display device to which it is applied, etc. The amount is about 3 to 30 parts by weight with respect to 100 parts by weight of the resin constituting the agent layer.

  The haze value of the pressure-sensitive adhesive layer in which the light diffusing agent is dispersed ensures the brightness of the liquid crystal display device to which the circularly polarizing plate provided with the pressure-sensitive adhesive layer is applied, and also makes it difficult to cause bleeding and blurring of the display image. Therefore, it is preferable to be in the range of 20 to 80%. The haze value is a value represented by (diffuse transmittance / total light transmittance) × 100 (%), and is measured according to JIS ° K ° 7105.

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

  The primer layer usually contains a transparent resin and is formed from a transparent resin solution. The primer layer can suppress defects in the retardation layer or the polarizing layer when forming the pressure-sensitive adhesive layer. As the transparent resin, those having excellent coating properties and excellent transparency and adhesion after forming the primer layer are preferable.

  The solvent of the transparent resin solution includes aromatic hydrocarbon solvents such as benzene, toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethyl acetate, isobutyl acetate and the like, depending on the transparent solubility. Ester solvent; Chlorinated hydrocarbon solvent such as methylene chloride, trichloroethylene, chloroform, etc .; General organic solvents such as ethanol, 1-propanol, 2-propanol, 1-butanol and other alcohol solvents can be used. When the primer layer is formed using a transparent resin solution containing, the optical properties of the liquid crystal cured film may be affected. Therefore, it is preferable to form the primer layer using a solution containing water as a solvent.

  An example of the transparent resin is an epoxy resin. The epoxy resin may be a one-component curable type or a two-component curable type. A water-soluble epoxy resin is particularly preferable. As a water-soluble epoxy resin, a polyamide epoxy resin obtained by reacting epichlorohydrin with a polyamide polyamine obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid. Is mentioned. Examples of commercially available polyamide epoxy resins include Sumire Resin (registered trademark) 650 (30) and Sumire Resin (registered trademark) 675 (registered trademark) sold by Sumika Chemtex Co., Ltd.

  When a water-soluble epoxy resin is used as the transparent resin, it is preferable to use another water-soluble resin such as a polyvinyl alcohol resin in order to further improve the coating property. Polyvinyl alcohol resins are modified polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. Alcohol-based resin may be used. Examples of suitable commercially available polyvinyl alcohol resins include KL-318 (trade name), which is an anionic group-containing polyvinyl alcohol sold by Kuraray Co., Ltd.

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

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

  The pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive to the surface of the retardation layer, polarizing layer or primer layer and drying it. After forming the pressure-sensitive adhesive layer by coating and drying, a method of bonding this film with the pressure-sensitive adhesive layer to the surface of the retardation layer, polarizing layer or primer layer so that the pressure-sensitive adhesive layer side becomes the bonding surface Can also be formed. The primer layer surface on which the pressure-sensitive adhesive layer is formed is preferably subjected to corona discharge treatment in advance. Thereby, the adhesiveness of a primer layer and an adhesive layer can further be improved.

  Examples of the method for applying the pressure-sensitive adhesive include the same methods as those exemplified as the method for applying the orientation polymer composition to the substrate. Examples of the method for removing the solvent from the applied pressure-sensitive adhesive include the same method as the method for removing the solvent from the oriented polymer composition.

The peel strength of the present circularly polarizing plate having a pressure-sensitive adhesive layer on the surface is measured as follows.
A test piece having a width of 25 mm and a length of about 200 mm is cut from the circularly polarizing plate having a pressure-sensitive adhesive layer on the surface, and the pressure-sensitive adhesive surface is bonded to a glass plate. JIS K 6854-1: 1999 “Adhesive-peeling” at one end in the length direction (one side of 25 mm width), at an ambient temperature of 23 ° C. and a relative humidity of 60%, with a crosshead speed of 200 mm / min. A 90 ° peel test is performed in accordance with “Adhesion strength test method—Part 1: 90 degree peeling”.
The peel strength (F1) between the base material and the first alignment film in the circularly polarizing plate having the base material, the first alignment film, the polarizing layer, the second alignment film, the retardation layer and the pressure-sensitive adhesive layer in this order is More than the peel strength (F2) between the first alignment film and the polarizing layer, the peel strength (F3) between the second alignment film and the retardation layer, and the peel strength (F4) between the retardation layer and the pressure-sensitive adhesive layer. Low is preferable. The peel strength (F1) can be adjusted by the substrate and the first alignment film.
For example, a substrate having a functional group that forms a chemical bond with the alignment film on the surface tends to increase the peel strength (F1) between the substrate and the first alignment film. Therefore, as a base material for reducing the peel strength (F1), a base material having a small number of functional groups on the surface is preferable, and a base material that has not been subjected to a surface treatment for forming a functional group on the surface is preferable.
Moreover, the alignment film having a functional group that forms a chemical bond with the base material tends to increase the peel strength (F1) between the base material and the first alignment film. Therefore, as the alignment film for reducing the peel strength (F1), an alignment film having few functional groups that form a chemical bond with the substrate is preferable. In order to reduce (F1), it is preferable that the alignment polymer composition or the composition for forming a photo-alignment film does not contain a reagent that crosslinks the substrate and the alignment film. It is preferred that no components such as solvents are dissolved. When the substrate surface is dissolved by the alignment polymer composition or the photoalignment film forming composition, the peel strength (F1) between the substrate and the first alignment film tends to increase.
In order to increase the peel strength (F2), (F3), and (F4), the first alignment film and the polarizing layer, the second alignment film and the retardation layer, and the retardation layer and the adhesive layer A chemical bond may be formed between them.

By removing the substrate from the circularly polarizing plate having the pressure-sensitive adhesive layer on the surface, a circularly polarizing film having the pressure-sensitive adhesive layer is obtained. Arbitrary methods are mentioned as a method of removing a base material.
The thickness of the circularly polarizing film having the pressure-sensitive 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 pressure-sensitive adhesive layer can be usually determined by measurement with an interference film thickness meter, a laser microscope, or a stylus thickness meter.

  Then, the method to manufacture this circularly-polarizing plate continuously is demonstrated. As a suitable method for producing such a circularly polarizing plate continuously, a method using a Roll to Roll format can be mentioned.

In particular,
(1) a step of preparing a roll in which the base material is wound around the core;
(2) a step of continuously feeding the base material from the roll;
(3) a step of continuously forming an alignment film on the substrate;
(4) A step of 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 phase difference layer of the roll obtained in (4),
(6) A step of applying an alignment film on the protective layer obtained in the above (5) and continuously forming it,
(7) The process of apply | coating the composition B on the orientation film obtained by said (6), and forming a polarizing layer continuously,
(8) A step of bonding the film with the pressure-sensitive adhesive layer on the polarizing layer obtained in (7) so that the pressure-sensitive adhesive layer side becomes a bonding surface,
(9) The method of winding the circularly-polarizing plate obtained continuously on the 2nd core, and performing the process of obtaining a 2nd roll in order is mentioned. Steps (5) and (8) may be omitted as necessary.

Also,
(1a) a step of preparing a roll in which the substrate is wound around the core;
(2a) a step of continuously feeding the base material from the roll;
(3a) a step of continuously forming an alignment film on the substrate;
(4a) A step of applying the composition B on the alignment film and continuously forming a polarizing layer;
(5a) a step of continuously forming a protective layer on the polarizing layer of the roll obtained in (4a),
(6a) A step of applying an alignment film on the protective layer obtained in (5a) above and continuously forming the alignment layer;
(7a) A step of applying the composition A on the alignment film obtained in (6a) and continuously forming a retardation layer,
(8a) A step of bonding the film with the pressure-sensitive adhesive layer on the retardation layer obtained in (7a) so that the pressure-sensitive adhesive layer side becomes a bonding surface,
(9a) The method of winding the circularly-polarizing plate obtained continuously on the 2nd core, and performing the process of obtaining a 2nd roll in order is also mentioned. Steps (5a) and (8a) may be omitted as necessary.

Also,
(1b) a step of preparing a roll in which the substrate is wound around the core;
(2b) a step of continuously feeding the base material from the roll;
(3b) a step of continuously forming an alignment film on the substrate;
(4b) A step of applying the composition A on the alignment film and continuously forming a retardation layer;
(5b) A step of applying an alignment film on the surface opposite to the phase difference layer of the roll obtained in (4b), and continuously forming the film,
(6b) A step of applying the composition B on the alignment film obtained in (5b) and continuously forming a polarizing film;
(7b) The method of winding up the circularly-polarizing plate obtained continuously on the 2nd core, and performing the process of obtaining a 2nd roll in order is also mentioned.

Also,
(1c) a step of preparing a roll in which the transparent substrate is wound around the core;
(2c) a step of continuously feeding the transparent substrate from the roll;
(3c) a step of continuously forming an alignment film on the transparent substrate;
(4c) A step of applying a composition containing the composition B on the alignment film and continuously forming a polarizing layer;
(5c) a step of continuously forming an alignment film on the surface opposite to the polarizing layer of the roll obtained in (4c),
(6c) A step of applying the composition A on the alignment film obtained in (5c) and continuously forming a retardation layer,
(7c) The method of winding up the circularly-polarizing plate obtained continuously on the 2nd core, and performing the process of obtaining a 2nd roll in order is also mentioned.

  In FIG. 1, the schematic of this circularly-polarizing plate is shown. FIG. 1A shows a circularly polarizing plate in which a base material, a retardation layer, and a polarizing layer are laminated in this order. FIG. 1B shows a circularly polarizing plate in which a base material, a polarizing layer, and a retardation layer are laminated in this order.

This circularly polarizing plate can be used for various display devices. Moreover, the circularly-polarizing plate which has an adhesive layer on the surface can be used for manufacture of various display apparatuses. Specifically, a circularly polarizing plate having a pressure-sensitive adhesive layer on its surface is bonded to the display surface of the display device via the pressure-sensitive adhesive layer, whereby a display device provided with the circularly polarizing plate is obtained. By removing the substrate, a display device with a circularly polarizing film provided with the circularly polarizing film of the present invention can be 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. As the display device, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (for example, a field emission display device (FED), a surface field emission display device) (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (eg, grating light valve (GLV) display device, display device having digital micromirror device (DMD)) The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct view liquid crystal display device, and a projection liquid crystal display device. These display devices include a table for displaying a two-dimensional image. It may be a device or a three-dimensional display device that displays a three-dimensional image, and particularly effectively used for a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device. it can.

  FIG. 2 is a schematic diagram showing a liquid crystal display device 10 which is one of the display devices of the present invention. The liquid crystal layer 15 is sandwiched between 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 facing the pixel electrode 20 across the liquid crystal layer 15, and the black matrix 18 is disposed at a position facing the boundary between the pixel electrodes. A transparent electrode 14 covers them. An overcoat layer may be provided between the color filter 13 and the transparent electrode 14.

  Thin film transistors 19 and pixel electrodes 20 are regularly arranged on the liquid crystal layer 15 side of the substrate 12b. The pixel electrode 20 is disposed at a position facing the color filter 13 across the liquid crystal layer 15. 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. When manufacturing the color filter 13 and the thin film transistor 19 formed on these substrates, the substrate 12a and the substrate 12b are preferably glass substrates when it is necessary to heat to a high temperature.

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

  A liquid crystal layer 15 is disposed between the transparent electrode 14 and the pixel electrode 20. Spacers 21 are formed in the liquid crystal layer 15 in order to keep the distance between the substrate 12a and the substrate 12b constant. Of the layers formed on the substrate 12a and the substrate 12b, 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 in contact with the liquid crystal layer 15.

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

  The circularly polarizing plate 11a and the circularly polarizing plate 11b are stacked on the outside of the substrate 12a and the substrate 12b with the liquid crystal layer 15 interposed therebetween. A backlight unit 17 serving as a light source is disposed outside the circularly polarizing plate 11b. The backlight unit 17 includes a light source, a light guide, a reflection plate, a diffusion sheet, and a viewing angle adjustment sheet. As a light source, various light sources, such as electroluminescence (EL), a cold cathode tube, a hot cathode tube, a light emitting diode (LED), a laser light source, 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. 3A includes the circularly polarizing plate 31, and a light emitting layer is formed on a substrate 32 on which a pixel electrode 34 is formed via an interlayer insulating film 33. 35 and the cathode electrode 36 are laminated. The circularly polarizing plate 31 is disposed on the side opposite to the light emitting layer 35 with the substrate 32 interposed therebetween. By applying a positive voltage to the pixel electrode 34 and a negative voltage to the cathode electrode 36 and applying a direct current between the pixel electrode 34 and the cathode electrode 36, the light emitting layer 35 emits 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 circular polarizing plate 31.

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

  Next, the circularly polarizing plate 31 is provided on the surface of the substrate 32 opposite to the surface on which the thin film transistor 38 is provided. In that case, the quarter wavelength layer of the circularly 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 and a ceramic substrate such as alumina; a metal substrate such as copper; a plastic substrate. Although not shown, a heat conductive film may be formed on the substrate 32. Examples of the thermally conductive film include a diamond thin film (DLC or the like). When the pixel electrode 34 is of a reflective type, light is emitted in the direction opposite to the substrate 32. Therefore, not only a transparent material but also a non-permeable material such as stainless steel can be used. A single substrate may be formed, or a plurality of substrates may be bonded together with an adhesive to form a laminated substrate. Further, these substrates are not limited to plate-like ones, and may be films.

  As the thin film transistor 38, for example, a polycrystalline silicon transistor 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. The size of the pixel electrode 34 is about 20 μm × 20 μm to 300 μm × 300 μm.

  On the substrate 32, a wiring electrode of the thin film transistor 38 is provided. The wiring electrode has a low resistance and has a function of being electrically connected to the pixel electrode 34 to suppress the resistance value. Generally, the wiring electrode includes Al, Al and transition metals (except for Ti), Ti or One containing one or more of titanium nitride (TiN) is used.

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

  A rib 39 is formed on the interlayer insulating film 33. The rib 39 is disposed in the peripheral portion (between adjacent pixels) of the pixel electrode 34. Examples of the material of the rib 39 include acrylic resin and polyimide resin. The thickness of the rib 39 is preferably 1.0 μm or more and 3.5 μm, more preferably 1.5 μm or more and 2.5 μm or less.

  Next, an EL element composed of the pixel electrode 34, the light emitting layer 35, and the cathode electrode 36 will be described. Each of the light emitting layers 35 includes at least one hole transport layer and a light emitting layer, and sequentially includes, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer.

Examples of the pixel electrode 34 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO _2, and In ₂ O _3, and ITO and IZO are particularly preferable. The pixel electrode 35 only needs to have a certain thickness or more that can sufficiently inject holes, and is preferably about 10 to 500 nm.

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

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

  The cathode electrode 36 is formed by vapor deposition or sputtering. The thickness of the cathode electrode 37 is 0.1 nm or more, preferably 1 to 500 nm or more.

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

  The thickness of the light-emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection / transport layer are not particularly limited and vary depending on the formation method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. For the formation of the hole injecting and transporting layer, the light emitting layer and the electron injecting and transporting layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

  As the light emitting layer 35, those using light emission (fluorescence) from singlet excitons, those using light emission (phosphorescence) from triplet excitons, and light emission (fluorescence) from singlet excitons. Including those using and light emission from triplet excitons (phosphorescence), those formed by organic matter, those including those formed by organic matter and those formed by inorganic matter, high A molecular material, a low molecular material, a material including a high molecular material and a low molecular material, or the like can be used. However, it is not limited to this, The light emitting layer 35 using various well-known things for EL elements can be used for 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 light emitting layer 35 is vulnerable to humidity. Water is absorbed by the desiccant to prevent the light emitting layer 35 from deteriorating.

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

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

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

Compound A1 and Compound A2 were synthesized by the method described in JP 2010-31223 A.
Compound A1 (80 parts):

Compound A2 (20 parts):

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

溶剤（９５部）：シクロペンタノン [Preparation of composition for forming photo-alignment film]
The following components were mixed, and the resulting mixture was stirred at 80 ° C. for 1 hour to obtain a composition for forming a photoalignment film.
Photo-alignment material (5 parts):

Solvent (95 parts): Cyclopentanone

化合物Ｂ２（化合物（Ｂ−７）；２５部）

二色性色素；
ビスアゾ化合物（１−１−１） ２．５部

ビスアゾ化合物（１−１−２） ２．５部

ビスアゾ化合物（１−４−１） ２．５部

重合開始剤；
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９；チバ スペシャルティケミカルズ社製） ６部
レベリング剤；
ポリアクリレート化合物（ＢＹＫ−３６１Ｎ；ＢＹＫ−Ｃｈｅｍｉｅ社製）
１．５部
溶剤；シクロペンタノン ２５０部 [Preparation of composition for forming polarizing 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 polarizing layer. Compound B1 and Compound B2 were synthesized by the method described in Japanese Patent No. 4719156.
Compound B1 (Compound (B-6); 75 parts)

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

Dichroic dyes;
Bisazo compound (1-1-1) 2.5 parts

Bisazo compound (1-1-2) 2.5 parts

Bisazo compound (1-4-1) 2.5 parts

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

[Measurement of phase transition temperature]
The obtained polarizing layer forming composition was applied onto glass and dried to prepare a measurement sample. When the phase transition temperature was confirmed by texture observation using a polarizing microscope, the phase transition to the nematic phase at 108 ° C. and the phase transition to the smectic A phase at 101 ° C. were 76 ° C. after the temperature was raised to 140 ° C. Thus, a phase transition to a smectic B phase was confirmed.

[Preparation of composition for forming an adhesive]
The following components were mixed at 55 ° C. under a nitrogen atmosphere to obtain an acrylic resin.
Butyl acrylate 70 parts Methyl acrylate 20 parts Acrylic acid 1.0 part Initiator: Azobisisobutyronitrile 0.2 part Solvent (80 parts): Ethyl acetate Further Coronate L (tolylene diisocyanate tri 75% ethyl acetate solution of methylolpropane adduct, 0.5 parts of isocyanate group in one molecule, manufactured by Nippon Polyurethane Industry Co., Ltd.) 0.5 part, silane coupling agent X-12-981 (manufactured by Shin-Etsu Silicone Co., Ltd.) 0.5 parts was mixed, and finally ethyl acetate was added so that the total solid content concentration was 10% to obtain a pressure-sensitive adhesive forming composition. The obtained pressure-sensitive adhesive forming composition was applied to a release-treated surface of a release-treated polyethylene terephthalate film (manufactured by Lintec Corporation) using an applicator so that the thickness after drying was 10 μm, It dried at 100 degreeC for 1 minute, and obtained the film (1) with an adhesive.

[Manufacture of circularly polarizing plates]
1. Formation of Alignment Film for Polarizing Layer KC4UY (TAC film, manufactured by Konica Minolta, Inc.), which is a cellulose-based film, was used as a transparent substrate film. On the film, the composition for forming a photo-alignment film was applied by a bar coating method and dried by heating in a drying oven at 60 ° C. for 1 minute. The obtained dried film was subjected to polarized UV irradiation treatment to form a first alignment film. The polarized UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.). The polarization direction of the polarized UV was set to 0 ° with respect to the slow axis of the retardation layer.

2. Formation of Polarizing Layer A composition for forming a polarizing layer was applied onto the formed first alignment film by a bar coating method, heated and dried in a drying oven at 120 ° C. for 1 minute, and then cooled to room temperature. Using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.), The polarizing film was formed by irradiating the dry film with ultraviolet rays at an exposure amount of 1200 mJ / cm ² (365 nm standard). It was 1.8 micrometers when the thickness of the obtained polarizing layer was measured with the laser microscope (OLS3000 by Olympus Corporation).

3. Formation of Protective Layer On the formed polarizing layer, 50 parts of dipentaerythritol hexaacrylate (Aronix M-403, manufactured by Toagosei Co., Ltd.), 50 parts of acrylate resin (Eveacryl 4858, manufactured by Daicel UC Corporation) and 2-methyl-1 A solution prepared by dissolving 3 parts of [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by Ciba Specialty Chemicals) in 250 parts of isopropanol (composition for forming a protective layer) ) Was applied by a bar coating method and dried by heating in a drying oven at 50 ° C. for 1 minute. By irradiating the obtained dried film with ultraviolet rays at an exposure amount of 400 mJ / cm ² (365 nm standard) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), A protective layer was formed.

4). Formation of Alignment Film for Retardation Layer On the formed protective layer, the composition for forming a photo-alignment film was applied by a bar coating method and dried by heating in a drying oven at 60 ° C. for 1 minute. The resulting dried film was subjected to polarized UV irradiation treatment to form a second alignment film. The polarized UV treatment was performed under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by USHIO INC.). The polarization direction of the polarized UV was 45 ° with respect to the absorption axis of the polarizing layer.

5. Formation of Retardation Layer On the formed second alignment film, a composition for forming a retardation layer was applied by a bar coating method, heated and dried in a drying oven at 120 ° C. for 1 minute, and then cooled to room temperature. A retardation layer is formed by irradiating the obtained dried film with ultraviolet rays having an exposure amount of 1000 mJ / cm ² (365 nm standard) using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.). did. It was 2.0 micrometers when the thickness of the obtained retardation layer was measured with the laser microscope (OLS3000 by Olympus Corporation).

  Thus, a broadband circularly polarizing plate could be produced. It was 45 micrometers when the total thickness of this circularly-polarizing plate was measured with the contact-type film thickness meter.

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

2. Measurement of reflectance In order to confirm the usefulness of the circularly polarizing plate, the reflectance was measured as follows. The retardation layer of the produced circularly polarizing plate and the reflector (mirror surface aluminum plate) were bonded using an adhesive to prepare a measurement sample.
Using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation), light in the wavelength range of 400 to 700 nm is incident on the measurement sample from 12 ° in the normal direction in steps of 2 nm, and the reflectance of the reflected light. Was measured. When the reflectance is calculated assuming that the reflectance when only the reflector is arranged without bonding the circularly polarizing plate is 100%, the reflectance of light having a wavelength in the range of 400 to 700 nm is about 1 to 10%. Thus, it was found that sufficient antireflection characteristics can be obtained over the entire visible light range.

Example 2
In the same manner as in Example 1, a first alignment film (the polarization direction of polarized UV is 45 ° with respect to the long side of the substrate film) is formed on one surface of the transparent substrate film. A retardation layer was formed. After forming the protective layer on the retardation layer, a second alignment film (the polarization direction of polarized UV is 0 ° with respect to the long side of the base film) is formed, and a polarizing layer is further formed on the photo-alignment film Thus, a circularly polarizing plate was produced.

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

Example 3
As the polymerizable liquid crystal compound B1, the compound (B-14) is used instead of the compound (B-6), and as the polymerizable liquid crystal compound B2, the compound (B-17) is used instead of the compound (B-7). A circularly polarizing plate was produced in the same manner as in Example 1 except that.

  Similarly to Example 1, when the reflectance was measured by bonding the retardation layer of the produced circularly polarizing plate and the reflector using an adhesive, the reflectance of light having a wavelength in the range of 400 to 700 nm was as follows. It was about 1 to 10%, and it was found that sufficient antireflection characteristics were obtained over the entire visible light range.

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

  In the same manner as in Example 1, when the reflectance was measured by bonding the prepared circularly polarizing plate to the reflector using an adhesive, the reflectance of light having a wavelength of 500 to 600 nm was as good as about 1 to 10%. 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 bluish purple, so that a sufficient antireflection function is provided. I knew that I couldn't get it.

Comparative Example 2
As a polarizing plate, an iodine-PVA polarizing plate (Sumikaran, Sumitomo Chemical Co., Ltd., thickness: 105 μm) was cut into small pieces of 100 × 100 mm so that the absorption axis was 0 °. The half-wave plate used in Example 1 was cut into small pieces of 100 × 100 mm so that the slow axis was 15 °. The quarter wavelength plate used in Comparative Example 1 was cut into small pieces of 100 × 100 mm so that the slow axis was 15 °. Each cut-out film was bonded to a single sheet using an acrylic pressure-sensitive adhesive (film thickness: 25 μm) so as to be a polarizing plate + 1/4 wavelength plate + 1/2 wavelength plate to prepare a circularly polarizing plate.

  Similarly to Example 1, the produced circularly polarizing plate was bonded to a reflector using an adhesive and the reflectance was measured. The reflectance of light having a wavelength in the range of 400 to 700 nm was 1 to 10%. Although it was found that sufficient antireflection characteristics were obtained over the entire visible light range, the total thickness of the circularly polarizing plate was measured with a contact-type film thickness meter and found to be 240 μm. It was about 5 times the total thickness of the polarizing plate.

Example 4
A circularly polarizing plate was produced in the same manner as in Example 1 except that a polyethylene terephthalate film was used in place of KC4UY (TAC film, manufactured by Konica Minolta Co., Ltd.), which is a cellulose film, as a substrate. A film (1) with an adhesive was bonded onto the retardation layer of this circularly polarizing plate to obtain a circularly polarizing plate having an adhesive layer. This sample is cut into a size of 40 mm x 40 mm, the attached film with adhesive is peeled off, pressure-bonded to a reflector (mirror surface aluminum plate), and the substrate is slowly removed, thereby circularly polarizing film An attached reflector was obtained. The thickness of the circularly polarizing film comprising the first alignment film, the polarizing layer, the protective layer, the second alignment film, the retardation layer and the pressure-sensitive adhesive layer was 14.7 μm.
The peel strength (F1) between the substrate and the first alignment film is the peel strength (F2) between the first alignment film and the polarizing layer, the peel strength (F3) between the second alignment film and the retardation layer, and Since it was lower than the peel strength (F4) between the retardation layer and the pressure-sensitive adhesive layer, peeling occurred between the substrate and the first alignment film, and the substrate could be removed.

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

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

1 circularly polarizing plate 2 base material 3 retardation layer 4 polarizing layer 5 dichroic dye 10 liquid crystal display devices 11a and 11b circularly polarizing plates 12a and 12b substrate 13 color filter 14 transparent electrode 15 liquid crystal layer 16 interlayer insulating film 17 back Light unit 18 Black matrix 19 Thin film transistor 20 Pixel electrode 21 Spacer 30 Organic EL display device 31 Circularly polarizing plate 32 Substrate 33 Interlayer insulating film 34 Pixel electrode 35 Light emitting layer 36 Cathode electrode 37 Sealing layer 38 Thin film transistor 39 Rib

Claims (21)

A retardation layer and a polarizing layer, wherein a birefringence index Δn (λ) of the retardation layer with respect to light having a wavelength of λ nm satisfies the expressions (1) and (2), and the retardation layer and the polarizing layer The layers are both coating layers, the total thickness of the retardation layer and the polarizing layer is 10 μm or less, and the polarizing layer has two or more types of dichroism having a maximum absorption wavelength in the range of 300 to 700 nm . A circularly polarizing plate containing a dye so that the reflectance of light having a wavelength in the range of 400 to 700 nm is 10% or less .
Δn (450) / Δn (550) ≦ 1.00 (1)
1.00 ≦ Δn (650) / Δn (550) (2)   The circularly polarizing plate according to claim 1, wherein the retardation layer is formed by polymerizing one or more polymerizable liquid crystals.   The circularly polarizing plate according to claim 1 or 2, wherein the polarizing layer is formed by polymerizing one or more polymerizable liquid crystals.   The circularly polarizing plate according to claim 2 or 3, wherein the polymerizable liquid crystal is polymerized by light irradiation.   The circularly polarizing plate according to any one of claims 1 to 4, wherein the polarizing layer is a polarizing layer capable of obtaining a Bragg peak in X-ray diffraction measurement.   The circularly polarizing plate according to claim 1, wherein each of the retardation layer and the polarizing layer has a thickness of 5 μm or less.   The circularly polarizing plate according to claim 1, wherein the retardation layer, the polarizing layer, or both are formed on the alignment film.   The circularly polarizing plate according to claim 7, wherein the alignment film is an alignment film in which an alignment regulating force is generated by light irradiation.   The circularly polarizing plate according to claim 7 or 8, wherein the alignment film has a thickness of 500 nm or less.   The retardation layer is formed on the substrate with or without an alignment film, and the polarizing layer is formed on the retardation layer with or without an alignment film. The circularly-polarizing plate in any one.   The polarizing layer is formed on the substrate with or without an alignment film, and the retardation layer is formed on the polarizing layer with or without an alignment film. The circularly polarizing plate according to crab.   The circularly polarizing plate according to claim 10 or 11, further comprising a protective layer between the polarizing layer and the retardation layer.   A polarizing layer is formed on one surface of the substrate with or without an alignment film, and a retardation layer is formed on the other surface of the substrate with or without an alignment film. The circularly-polarizing plate in any one of 1-9.   Furthermore, the circularly-polarizing plate in any one of Claims 1-13 which has an adhesive layer on the surface of a phase difference layer or a polarizing layer.   The circularly-polarizing plate of Claim 14 which has a base material, a 1st alignment film, a polarizing layer, a 2nd alignment film, a phase difference layer, and an adhesive layer in this order.   The peel strength (F1) between the substrate and the first alignment film is the peel strength (F2) between the first alignment film and the polarizing layer, the peel strength (F3) between the second alignment film and the retardation layer, and The circularly-polarizing plate of Claim 15 lower than the peeling strength (F4) of a phase difference layer and an adhesive layer.   A display apparatus provided with the circularly-polarizing plate in any one of Claims 1-16, and a display element.   The circularly-polarizing film in which the circularly-polarizing film from which the base material was removed from the circularly-polarizing plate in any one of Claims 14-16 was bonded to the display surface of the display element through the adhesive layer of this circularly-polarizing film. A display device.   The display device according to claim 18, wherein the circularly polarizing film has a thickness of 5 μm to 15 μm.   The display device according to any one of claims 17 to 19, wherein the display element is a liquid crystal cell, an organic electroluminescence element, or a touch panel.   The circularly polarizing plate according to any one of claims 14 to 16 is attached to a display surface of a display element through an adhesive layer of the circularly polarizing plate, and the substrate is removed from the circularly polarizing plate. Manufacturing method of display device.

Images