Polarizing plate and method of manufacturing the same

Abstract

A polarizing plate having a curved shape comprising a curved substrate, a photoalignment film, and a polarizer in this order, wherein the polarizer is composed of a cured polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound having at least one polymerizable group and a dichroic pigment, and wherein the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces in one direction with respect to the plane direction of the curve of the curved substrate on which the polarizer is stacked.

Description

Technology Field

[0001] The present invention relates to a polarizing plate having a curved shape and a method for manufacturing said polarizing plate. Background Technology

[0002] Polarizing plates comprising a polarizer are used as components for various articles in a wide range of fields, including liquid crystal display devices, organic EL display devices using organic light-emitting diodes (OLEDs), as well as sunglasses and lens filters. Conventionally, as such polarizing plates, a polarizing plate having a configuration in which a protective layer, such as a triacetylcellulose film, is laminated with an adhesive layer interposed on at least one surface of a polarizer in which a compound exhibiting dichroism, such as iodine or a dichroic dye, is adsorbed and oriented on a polyvinyl alcohol-based resin film is widely used (e.g., Patent Document 1). Prior art literature

[0003] Japanese Published Patent Application No. 2008-527401 The problem to be solved

[0004] Recently, as the applications of polarizing plates have increased across various fields, it has become necessary to form polarizing plates on articles with a curved shape rather than a flat shape, depending on the application. However, when forming a polarizing plate with a curved shape, if a film-type polarizing plate as described in Patent Document 1 is used, wrinkles or deformation are prone to occur when laminated to the curved surface. This not only results in defects in appearance and optical properties but may also cause a decrease in adhesion to the surface on which the polarizing plate is laminated. The occurrence of wrinkles or deformation when using such a film-type polarizing plate, and the problems arising therefrom, are particularly likely to become pronounced when forming a polarizing plate on a three-dimensional curved surface rather than a flat surface.

[0005] The present invention aims to provide a polarizing plate having a curved shape with excellent lamination properties with respect to the lamination surface. means of solving the problem

[0006] The inventors, as a result of careful consideration to solve the above problem, have completed the present invention. That is, the present invention includes the following embodiments.

[0007] [1] A polarizing plate having a curved shape, comprising a curved substrate, a light alignment film and a polarizer in this order,

[0008] The above polarizer is composed of a cured product of a polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound having at least one polymerizable group and a dichroic pigment, and

[0009] A polarizing plate in which the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces in one direction with respect to the plane direction of the curved surface of the curved substrate on which the polarizer is stacked.

[0010] [2] A polarizing plate described in [1] above, having a three-dimensional curved shape.

[0011] [3] A polarizing plate described in [1] or [2] above, having a curved shape that is lens-like.

[0012] [4] Formula (1) :

[0013] 20 mm ≤ R ≤ 300 mm (1)

[0014] [In Equation (1), R represents the radius of curvature of the part with the smallest curvature in the polarizer]

[0015] A polarizing plate described in any one of [1] to [3] above, satisfying the above.

[0016] [5] A polarizing plate described in any one of [1] to [4], wherein the polarizer additionally includes a leveling agent.

[0017] [6] A polarizing plate described in any one of [1] to [5] above, in which the dichroic pigment is an azo pigment.

[0018] [7] A polarizer described in any one of [1] to [6], in which the polarizer exhibits a Bragg peak in X-ray analysis measurements.

[0019] [8] An elliptical polarizer comprising a polarizer described in any one of [1] to [7] above and a phase difference layer having a quarter-wave plate function.

[0020] [9] (a) A process for forming a photo-alignment film on a curved substrate,

[0021] (b) a process of forming a coating of a polymerizable liquid crystal composition comprising at least one polymerizable liquid crystal compound and a dichroic pigment on a photoalignment film, and,

[0022] (c) A process comprising forming a polarizer by phase transitioning the polymerizable liquid crystal compound included in the polymerizable liquid crystal composition into a smectic liquid crystal phase, and then polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state.

[0023] A method for manufacturing a polarizing plate having a curved shape, wherein the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces in one direction with respect to the plane direction of the curved surface of the curved substrate on which the polarizer is stacked.

[0024]

[10] A flexible image display device having an elliptical polarizer as described in [8] above.

[0025]

[11] A flexible image display device described in

[10] above, having additionally a window and a touch panel touch sensor. Effects of the invention

[0026] According to the present invention, a polarizing plate having a curved shape with excellent lamination properties with respect to the laminated surface can be provided. Specific details for implementing the invention

[0027] Hereinafter, embodiments of the present invention will be described in detail. Furthermore, the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made within a scope that does not impede the spirit of the invention.

[0028] The polarizer of the present invention comprises a curved substrate, a photoalignment film, and a polarizer in this order. Since the photoalignment film and the polarizer are laminated on the curved substrate, the polarizer of the present invention is a polarizer having a curved shape in at least a portion thereof.

[0029] In the present invention, a curved shape refers to a shape having a curvature greater than 0, and includes a curved shape that is a quaternary surface and a three-dimensional curved shape. A quaternary surface refers to a surface that can be unfolded into a plane without stretching or contracting each part of the surface, and examples of curved shapes include a surface corresponding to part or all of a cylindrical surface, an elliptical surface, a cone surface, and an elliptical cone surface, and may be a convex curved shape or a concave curved shape. A three-dimensional curved shape refers to a curved shape that does not hold in the deformation of a plane, that is, a curved shape that is not a quaternary surface, and examples of three-dimensional curved shapes include a surface corresponding to part or all of a sphere or an elliptical sphere, a surface corresponding to part or all of a curved shape whose cross-section forms a parabola or a hyperbola, and may be a convex curved shape or a concave curved shape. In addition, the polarizing plate of the present invention may have a curved shape in at least a part thereof, may have a shape that combines a planar shape and a curved shape, or the entire polarizing plate may have a curved shape. Furthermore, the curved shape included in the polarizing plate may be either a curved shape that is a former surface or a three-dimensional curved shape, a combination of a curved shape that is a former surface and a three-dimensional curved shape, or a combination of a curved shape that is a former surface and / or a three-dimensional curved shape and a planar shape.

[0030] The polarizer constituting the polarizer of the present invention is composed of a cured product of a polymerizable liquid crystal composition, and even for substrates with three-dimensional curved shapes where it is difficult to laminate film-type polarizers, such as polyvinyl alcohol resin films adsorbing dichroic pigments that are widely used as conventional polarizers, it becomes possible to easily form a polarizer while maintaining a high orientation order along the curved shape. For this reason, when the curved shape included in the polarizer is a three-dimensional curved shape that cannot be obtained by unfolding a planar film, the effects of the present invention can be achieved more significantly. Accordingly, in one embodiment of the present invention, the polarizer of the present invention includes a three-dimensional curved shape.

[0031] In one embodiment of the present invention, the curved shape of the polarizing plate is preferably a lens shape. A lens-shaped curved shape refers to a curved shape in which the curvature is constant in all directions on the curved surface. Examples of lens-shaped curved shapes include a sphere, an elliptical sphere, a hemisphere, a semi-elliptical sphere, and may be a convex lens shape or a concave lens shape. The polarizing plate of the present invention can provide a lens-shaped polarizing plate with excellent external characteristics and optical characteristics because it has excellent stackability of polarizers with respect to the stacking surface and can suppress the occurrence of wrinkles or deformation in each layer constituting the polarizing plate.

[0032] In one embodiment of the present invention, the polarizing plate of the present invention preferably satisfies Equation (1).

[0033] 20 mm ≤ R ≤ 300 mm (1)

[0034] [In Equation (1), R represents the radius of curvature of the part with the smallest curvature in the polarizer.]

[0035] Equation (1) means that the radius of curvature at the gentlest curve of the polarizing plate is 20 mm or more and 300 mm or less. The polarizing plate of the present invention can realize high stackability of polarizers formed on a curved substrate even when having a curved shape with relatively large curvature. For this reason, the radius of curvature R of the part with the smallest curvature in the polarizing plate of the present invention (hereinafter simply referred to as "radius of curvature R") may be, for example, 250 mm or less, or 200 mm or less. Furthermore, the radius of curvature R is more preferably 25 mm or more, and even more preferably 30 mm or more. If the radius of curvature R is greater than or equal to the above lower limit, stackability is more easily improved.

[0036] In the polarizer of the present invention, the radius of curvature R' of the portion with the largest curvature (hereinafter also simply referred to as "radius of curvature R'") is preferably 10 mm or more, more preferably 15 mm or more, even more preferably 20 mm or more, particularly preferably 25 mm or more, and particularly more preferably 30 mm or more. If the radius of curvature R' is greater than or equal to the lower limit above, it is easier to further improve the lamination and adhesion of the polarizer to be laminated as a cured layer (coating layer) of the polymerizable liquid crystal composition, and it is easier to obtain a polarizer that is less likely to cause delamination or lifting of the polarizer, which is the cured layer. Since the polarizer of the present invention can realize high lamination of the polarizer formed on the curved substrate even when having a curved shape with a relatively large curvature, the radius of curvature R' may be, for example, 250 mm or less, 200 mm or less, or 150 mm or less.

[0037] In addition, when the curved shape included in the polarizer is a shape having the same curvature in all directions of the curve, such as a curved shape on a lens, the radius of curvature R'' is typically greater than or equal to the lower limit of the radius of curvature R'' and less than or equal to the upper limit of the radius of curvature R.

[0038] The polarizing plate of the present invention is a polarizing plate having a curved shape on at least a part thereof, and includes a curved substrate as a substrate for laminating a photoalignment film and a polarizer. In the present invention, a curved substrate refers to a substrate having a surface on which at least a part is curved, and the entire surface of the substrate may be curved. The curved substrate typically has the same curved shape as described above as the curved shape of the polarizing plate of the present invention.

[0039] The curved substrate is not particularly limited as long as it is made of a material capable of forming a desired curved shape, and can be appropriately selected from known materials depending on the desired curved shape, the application of the polarizer, etc. Examples include glass substrates, film substrates, and metal substrates. From the perspective of ease of forming various curved shapes, the curved substrate is preferably made of a glass substrate or a film substrate, and more preferably made of a glass substrate or a resin film substrate. Since the polarizer of the present invention typically constitutes an article requiring light transmission, such as a display device, sunglasses, or a lens filter, without removing the curved substrate, it is preferable that the curved substrate be made of a light-transmitting material in terms of optical properties.

[0040] In addition, in the present invention, a substrate having light transmittance refers to a substrate having the characteristic of being able to transmit light, particularly visible light, and light transmittance refers to a characteristic in which the transmittance for light rays with a wavelength of 380 nm to 780 nm is 80% or more. Also, although it varies depending on the configuration of the polarizer, it is generally preferred to be optically isotropic.

[0041] Examples of transparent substrates include glass substrates and transparent resin film substrates.

[0042] Examples of resins constituting the resin film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; cellulose ester; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide; and polyphenylene oxide. From the perspective of forming a polarizer, a glass substrate or a material having similar hardness is suitable as the substrate.

[0043] The curved member itself, which constitutes an article such as a display device equipped with a polarizing plate of the present invention, may be used as a curved substrate.

[0044] Surface treatments such as corona treatment and plasma treatment, or release treatments such as silicon treatment, may be performed on the surface of the surface substrate. Additionally, hard coating treatment, anti-reflective treatment, anti-static treatment, etc., may be performed on the substrate surface on the side where the polarizer is not laminated.

[0045] The thickness of the curved substrate can be appropriately determined according to the shape of the curve, the material constituting the curved substrate, the use of the polarizer, etc. The entire curved substrate may have the same thickness or may have different thicknesses. The thickness of the curved substrate is, for example, 30 μm to 5 cm, preferably 100 μm to 3.5 cm, and more preferably 500 μm to 3 cm.

[0046] The polarizer constituting the polarizer of the present invention is composed of a cured product of a polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound having at least one polymerizable group and a dichroic pigment. The polarizer composed of the cured product of the polymerizable liquid crystal composition is a coating layer obtained by applying a polymerizable liquid crystal composition onto a surface forming the polarizer, as described below, and polymerizing the polymerizable liquid crystal compound in an oriented state. By forming the polarizer as a coating layer, high stackability of the polarizer can be realized for curved surface shapes having various curvatures. High stackability makes it easier to maintain a high orientation order of the polarizer and easy to exhibit excellent optical properties. Furthermore, in the present invention, "stacking ability" refers to a characteristic in which, when forming a layer such as a polarizer on a surface to be stacked, there are no wrinkles, deformations, or uneven coating in the stacked layer, and lifting or delamination from the surface to be stacked is difficult to occur.

[0047] In a polarizer, the polymerizable liquid crystal compound is oriented such that its absorption axis faces in a single direction along the plane of the curved surface of the curved substrate on which the polarizer is stacked. If the polymerizable liquid crystal compound constituting the polarizer is oriented such that its absorption axis faces in a single direction, the polarizer becomes one with a high degree of orientation order of the polymerizable liquid crystal compound, thereby enabling the acquisition of a polarizing plate with excellent optical properties.

[0048] Here, the statement that the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces a single direction means that, in the case of a curved surface which is a valence plane, the polymerizable liquid crystal compound is oriented such that when the curved surface is unfolded into a plane, the absorption axis of the polarizer faces a single direction on that plane. Furthermore, in the case of a three-dimensional curved surface such as a sphere, the statement means that when the curved surface is viewed from a single direction in a plane, the absorption axis of the polarizer faces a single direction on that plane, and the polymerizable liquid crystal compound is oriented such that the direction of the polarizer's absorption axis faces the same direction as the aforementioned specific single direction across the entire curved surface. In this specification, the statement that the absorption axis of the polarizer faces a single direction means a state in which the direction of the polarizer's absorption axis faces substantially the same direction, and specifically, it means that the misalignment of the polarizer's absorption axis direction in a single curved surface connected as a plane is within 15°.

[0049] In the present invention, the polymerizable liquid crystal compound (hereinafter referred to as "polymerizable liquid crystal compound (A)" included in the polymerizable liquid crystal composition forming a polarizer (hereinafter also referred to as "polymerizable liquid crystal composition (A)") is a compound having at least one polymerizable group. Here, a polymerizable group refers to a group capable of participating in a polymerization reaction by means of an active radical or acid generated from a polymerization initiator. Examples of polymerizable groups having the polymerizable liquid crystal compound (A) include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, a (meth)acryloyl group, an oxiranyl group, an oxetanyl group, etc. Among these, a radical polymerizable group is preferred, a (meth)acryloyl group, a vinyl group, a vinyloxy group is more preferred, and a (meth)acryloyl group is even more preferred.

[0050] In the present invention, it is preferable that the polymerizable liquid crystal compound (A) is a compound exhibiting smectic liquid crystallization. By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallization, a polarizer with a high degree of orientation order can be formed. From the perspective of realizing a higher degree of orientation order, it is more preferable that the liquid crystal state exhibited by the polymerizable liquid crystal compound (A) is a higher-order smectic phase (higher-order smectic liquid crystal state). Here, the higher-order smectic phase refers to the 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, and among these, the smectic B phase, smectic F phase, and smectic I phase are more preferable. The liquid crystallization may be either thermotropic liquid crystal or lyotropic liquid crystal, but thermotropic liquid crystal is preferred in that it allows for dense film thickness control. Also, the polymerizable liquid crystal compound (A) may be a monomer, but may also be an oligomer or a polymer in which the polymerizable group is polymerized.

[0051] As for the polymerizable liquid crystal compound (A), any known polymerizable liquid crystal compound having at least one polymerizable group may be used, but as a polymerizable liquid crystal compound exhibiting smectic liquid crystallization, for example, a compound represented by the following formula (A1) (hereinafter referred to as "polymerizable liquid crystal compound (A1)") may be used.

[0052] U 1 -V 1 -W 1 -(X 1 -Y 1 ) n -X 2 -W 2 -V 2 -U 2 (A1)

[0053] [Essence (A1),

[0054] X 1 and X 2...independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein the hydrogen atom included in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, a C1-4 alkyl group, a C1-4 fluoroalkyl group, a C1-4 alkoxy group, a cyano group, or a nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. provided that X 1 and X 2 At least one of them is a 1,4-phenylene group that may have a substituent or a cyclohexane-1,4-diyl group that may have a substituent.

[0055] Y 1 It is a single bond or a two-linked connector.

[0056] n is 1 to 3, and when n is 2 or greater, multiple X 1 They may be identical or different. X 2 is, multiple X 1 It may be identical to any or all of the above, or different. Also, if n is 2 or greater, multiple Y 1 They may be identical or different. From the perspective of liquid crystallinity, n is preferably 2 or greater.

[0057] U 1 It represents a hydrogen atom or a polymerizable group.

[0058] U 2 represents a polymerizable group.

[0059] W 1 and W 2 It is a single coupling or a two-linker, independently of each other.

[0060] V 1 and V 2...represents an alkanedyl group having 1 to 20 carbon atoms that may independently have substituents, and the -CH2- constituting the alkanedyl group may be substituted with -O-, -CO-, -S-, or -NH-.

[0061] In a polymerizable liquid crystal compound (A1), X 1 and X 2 is, independently of each other, preferably, a 1,4-phenylene group that may have a substituent, or a cyclohexane-1,4-diyl group that may have a substituent, and X 1 and X 2 At least one of them is a 1,4-phenylene group that may have a substituent, or a cyclohexane-1,4-diyl group that may have a substituent, and is preferably a trans-cyclohexane-1,4-diyl group. Optional substituents for the 1,4-phenylene group that may have a substituent, or the cyclohexane-1,4-diyl group that may have a substituent, may include alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, and butyl groups, cyano groups, and halogen atoms such as chlorine and fluorine atoms. Preferably, it is unsubstituted.

[0062] Also, the polymerizable liquid crystal compound (A1) is, among formula (A1), formula (A1-1):

[0063] -(X 1 -Y 1 ) n -X 2 - (A1-1)

[0064] [Among the formulas, X 1 , Y 1 , X 2 and n each represent the same meaning as above.

[0065] It is desirable that the part represented by [hereinafter also referred to as the part structure (A1-1)] has an asymmetric structure, as this makes it easy to exhibit smectic liquid crystallization.

[0066] As for the polymerizable liquid crystal compound (A1) in which the substructure (A1-1) is an asymmetric structure, for example, n is 1 and 1 X 1 and X 2 Examples include polymerizable liquid crystal compounds (A1) having different structures. Also, n is 2 and 2 Y 1 As a compound with the same structure, 2 X 1 These have the same structure, and 1 X 2 These 2 X 1 A polymerizable liquid crystal compound (A1) with a structure different from that of 2 X 1 W in middle 1 X that binds to 1 This, the other party's X 1 and X 2 It has a different structure from, and the other side's X 1 and X 2 Examples also include polymerizable liquid crystal compounds (A1) having identical structures. Additionally, n is 3, and 3 Y 1 As a compound with the same structure, 3 X 1 and 1 X 2 Polymerizable liquid crystal compounds (A1) in which one of them has a structure different from all three other ones can be cited.

[0067] Y 1 Silver, -CH2CH2-, -CH2O-, -CH2CH2O-, -COO-, -OCOO-, single bond, -N=N-, -CR a =CR b -, -C≡C-, -CR a =N- or -CO-NR a - is desirable. R a and R b represents, independently of each other, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y 1 It is more preferable that it be -CH2CH2-, -COO-, or a single bond, and a plurality of Y 1 If this exists, X 2 Y combining with1 It is more preferable that it be -CH2CH2- or -CH2O-. X 1 and X 2 In the case where all have the same structure, 2 or more Ys with different bonding methods 1 It is desirable for this to exist. Multiple Ys with different combination modes. 1 In the presence of this, smectic liquid crystallization tends to be easily expressed because it results in an asymmetric structure.

[0068] U 2 is a polymerizable group. U 1 It is silver, a hydrogen atom, or a polymerizable group, preferably a polymerizable group. U 1 and U 2 It is preferable that it is a polymerizable group, and it is preferable that it is a radical polymerizable group. As for the polymerizable group, the same as the group previously exemplified as the polymerizable group of the polymerizable liquid crystal compound (A) can be cited. U 1 The polymerizable group represented by and U 2 The polymerizable groups represented by may be different from each other, but it is preferable that they be of the same type, and U 1 and U 2 It is preferable that at least one of the groups is a (meth)acryloyl group, and it is more preferable that both groups are (meth)acryloyl groups. In addition, the polymerizable group may be in a polymerizing state or in an unpolymerized state, but preferably in an unpolymerized state.

[0069] V 1 and V 2 Examples of alkanedyl groups represented by V include methylene groups, ethylene groups, propane-1,3-diyl groups, butane-1,3-diyl groups, butane-1,4-diyl groups, pentane-1,5-diyl groups, hexane-1,6-diyl groups, heptane-1,7-diyl groups, octane-1,8-diyl groups, decane-1,10-diyl groups, tetradecane-1,14-diyl groups, and icosan-1,20-diyl groups. 1 and V 2The is preferably an alkanedyl group having 2 to 12 carbon atoms, and more preferably an alkanedyl group having 6 to 12 carbon atoms.

[0070] The alkandyl group may optionally have substituents such as cyano groups and halogen atoms, but the alkandyl group is preferably unsubstituted, and more preferably an unsubstituted straight-chain alkandyl group.

[0071] W 1 and W 2 Independently, a single bond, -O-, -S-, -COO-, or -OCOO- is preferred, and a single bond or -O- is more preferred.

[0072] As for the polymerizable liquid crystal compound (A), any known polymerizable liquid crystal compound having at least one polymerizable group is not particularly limited, but it is preferable that it exhibit smectic liquid crystallization. For a structure that facilitates the exhibiting of smectic liquid crystallization, it is preferable that it has an asymmetric molecular structure within its molecular structure. Specifically, it is more preferable that the polymerizable liquid crystal compound exhibiting smectic liquid crystallization is a polymerizable liquid crystal compound having the following partial structures (Aa) to (Ai). It is more preferable to have the partial structures (Aa), (Ab), or (Ac) from the perspective of facilitating the exhibiting of higher-order smectic liquid crystallization. Furthermore, in the following (Aa) to (Ai), * indicates a bond loss (single bond).

[0073] [Chemical Formula 1]

[0074]

[0075] As for the polymerizable liquid crystal compound (A), specifically, compounds represented by formulas (A-1) to (A-25) can be cited. When the polymerizable liquid crystal compound (A) has a cyclohexane-1,4-diyl group, it is preferable that the cyclohexane-1,4-diyl group be a trans group.

[0076] [Chemical Formula 2]

[0077]

[0078] [Chemical Formula 3]

[0079]

[0080] [Chemical Formula 4]

[0081]

[0082] [Chemical Formula 5]

[0083]

[0084] [Chemical Formula 6]

[0085]

[0086] Among these, at least one type selected from the group consisting of compounds represented by formulas (A-2), (A-3), (A-4), (A-5), (A-6), (A-7), (A-8), (A-13), (A-14), (A-15), (A-16) and (A-17) is preferred. As for the polymerizable liquid crystal compound (A), one type may be used alone, or two or more types may be used in combination.

[0087] The polymerizable liquid crystal compound (A) can be prepared by a known method described in, for example, Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156, etc.

[0088] In the present invention, the polymerizable liquid crystal composition (A) may include other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound (A). From the perspective of obtaining a polarizing layer with a high degree of orientation order, the ratio of the polymerizable liquid crystal compound (A) to the total mass of all polymerizable liquid crystal compounds included in the polymerizable liquid crystal composition (A) is preferably 51 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more.

[0089] When a polymerizable liquid crystal composition (A) comprises two or more polymerizable liquid crystal compounds (A), at least one of them may be a polymerizable liquid crystal compound (A1), or all of them may be polymerizable liquid crystal compounds (A1). By combining multiple polymerizable liquid crystal compounds, liquid crystal properties may be temporarily maintained even at temperatures below the liquid crystal-crystal phase transition temperature.

[0090] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition (A) is preferably 40 to 99.9 mass% with respect to the solid content of the polymerizable liquid crystal composition (A), more preferably 60 to 99 mass%, and even more preferably 70 to 99 mass%. If the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to increase. Furthermore, in this specification, solid content refers to the total amount of components excluding volatile components such as solvents from the polymerizable liquid crystal composition (A). Likewise, for the polymerizable liquid crystal composition for forming a phase difference layer, etc., it refers to the total amount of components excluding volatile components such as solvents from the composition to be targeted.

[0091] In the present invention, the polymerizable liquid crystal composition (A) forming a polarizer comprises a dichroic pigment. Here, a dichroic pigment refers to a pigment having a property in which the absorbance in the direction of the long axis of the molecule and the absorbance in the direction of the short axis are different. The dichroic pigments that can be used in the present invention are not particularly limited as long as they have the above properties, and may be dyes or pigments. In addition, two or more types of dyes or pigments may be used in combination, a dye and a pigment may be used in combination, one type may be used, or two or more types may be used in combination. In addition, the dichroic pigment may have polymerizable properties and liquid crystal properties.

[0092] As a dichroic pigment, the maximum absorption wavelength (λ) in the range of 300 to 700 nm MAX It is desirable to have ). Examples of such dichroic pigments include acridin pigment, oxazine pigment, cyanine pigment, naphthalene pigment, azo pigment, and anthraquinone pigment.

[0093] Examples of azo dyes include monoazo dyes, bis-azo dyes, tris-azo dyes, tetrakis-azo dyes, and stilbenazo dyes, and bis-azo dyes and tris-azo dyes are preferred, and examples include the compound represented by formula (I) (hereinafter also referred to as “compound (I)”).

[0094] K 1 (-N=NK 2 ) p -N=NK 3 (I)

[0095] [Equation (I), K 1 and K 3 represents, independently, a phenyl group that may have substituents, a naphthyl group that may have substituents, or a monovalent complex ring that may have substituents. K 2 represents a p-phenylene group that may have substituents, a naphthalene-1,4-diyl group that may have substituents, or a divalent complex ring that may have substituents. p represents an integer from 1 to 4. If p is an integer greater than or equal to 2, multiple K 2 They may be identical or different. In the range exhibiting absorption in the visible spectrum, -N=N- bonds may be substituted with -C=C-, -COO-, -NHCO-, or -N=CH- bonds.

[0096] Examples of monovalent complex ring groups include groups obtained by removing one hydrogen atom from complex ring compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. Examples of divalent complex ring groups include groups obtained by removing two hydrogen atoms from the above complex ring compounds.

[0097] K 1 and K 3 The phenyl group, naphthyl group, and monovalent complex ring group in, and K 2 The substituents optionally provided by the p-phenylene group, naphthalene-1,4-diyl group, and divalent complex ring in the above include: an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms having a polymerizable group, an alkenyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 20 carbon atoms having methoxy, ethoxy, butoxy, etc.; an alkoxy group having 1 to 20 carbon atoms having a polymerizable group; a fluoroalkyl group having 1 to 4 carbon atoms having a trifluoromethyl group, etc.; a cyano group; a nitro group; a halogen atom; Examples include substituted or unsubstituted amino groups such as amino groups, diethylamino groups, and pyrrolidino groups (a substituted amino group refers to an amino group having one or two alkyl groups having 1 to 6 carbon atoms, an amino group having one or two alkyl groups having 1 to 6 carbon atoms having a polymerizable group, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms. An unsubstituted amino group is -NH2). In addition, examples of the above polymerizable groups include acryloyl groups, methacryloyl groups, acryloyloxy groups, and methacryloyloxy groups.

[0098] Among the compounds (I), a compound represented by any of the following formulas (I-1) to (I-8) is preferred.

[0099] [Chemical Formula 7]

[0100]

[0101] [Among formulas (I-1) to (I-8),

[0102] B 1 ~ B 30 Each represents, independently, a hydrogen atom, a C1-6 alkyl group, a C1-6 alkenyl group, a C1-4 alkoxy group, a cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of substituted amino groups and unsubstituted amino groups are as above), a chlorine atom, or a trifluoromethyl group.

[0103] n1 to n4 represent integers from 0 to 3 independently of each other.

[0104] If n1 is 2 or more, multiple B 2 They may be identical or different from each other,

[0105] If n2 is 2 or more, multiple B 6 They may be identical or different from each other,

[0106] If n3 is 2 or more, multiple B9s may be identical or different from each other,

[0107] If n4 is 2 or more, multiple B 14 They may be identical or different.

[0108] As the above anthraquinone pigment, a compound represented by formula (I-9) is preferred.

[0109] [Chemical Formula 8]

[0110]

[0111] [In food (I-9),

[0112] R1~ R 8 Silver, independently, hydrogen atoms, -R x , -NH2, -NHR x , -NR x 2, -SR x or represents a halogen atom.

[0113] R xrepresents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0114] As the above oxazone pigment, a compound represented by formula (I-10) is preferred.

[0115] [Chemical Formula 9]

[0116]

[0117] [In the food (I-10),

[0118] R 9 ~ R 15 is, independently of each other, hydrogen atoms, -R x , -NH2, -NHR x , -NR x 2, -SR x or represents a halogen atom.

[0119] R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0120] As the acridine pigment above, a compound represented by formula (I-11) is preferred.

[0121] [Chemical Formula 10]

[0122]

[0123] [In the food (I-11),

[0124] R 16 ~ R 23 Silver, independently, hydrogen atoms, -R x , -NH2, -NHR x , -NR x 2, -SR x or represents a halogen atom.

[0125] R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0126] In Equations (I-9), (I-10), and (I-11), R xExamples of alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, propyl groups, butyl groups, pentyl groups, and hexyl groups, and examples of aryl groups having 6 to 12 carbon atoms include phenyl groups, toluyl groups, xylyl groups, and naphthyl groups.

[0127] As the above cyanine pigments, the compound represented by formula (I-12) and the compound represented by formula (I-13) are preferred.

[0128] [Chemical Formula 11]

[0129]

[0130] [In the food (I-12),

[0131] D 1 and D 2 It represents a group that is independently represented by any of equations (I-12a) to (I-12d).

[0132] [Chemical Formula 12]

[0133]

[0134] n5 represents an integer from 1 to 3.

[0135] [Chemical Formula 13]

[0136]

[0137] [In the food (I-13),

[0138] D 3 and D 4 It represents a group that is independently represented by any of equations (I-13a) to (1-13h).

[0139] [Chemical Formula 14]

[0140]

[0141] n6 represents an integer from 1 to 3.

[0142] Among these dichroic pigments, azo pigments are desirable for the production of polarizers with excellent polarization performance because they have high linearity. Accordingly, in one embodiment of the present invention, the dichroic pigment included in the composition for forming a polarizing layer that forms a polarizer is preferably an azo pigment.

[0143] In the present invention, the weight average molecular weight of the dichroic pigment is typically 300 to 2000, and preferably 400 to 1000.

[0144] In one embodiment of the present invention, the dichroic pigment included in the polymerizable liquid crystal composition (A) forming a polarizer is preferably hydrophobic. If the dichroic pigment is hydrophobic, the compatibility between the dichroic pigment and the polymerizable liquid crystal compound is improved, and the dichroic pigment and the polymerizable liquid crystal compound form a uniform phase state, thereby obtaining a polarizer having a high degree of orientation order. Furthermore, in the present invention, a hydrophobic dichroic pigment refers to a pigment having a solubility of 1 g or less in 100 g of water at 25 ℃.

[0145] The content of the dichroic pigment in the polymerizable liquid crystal composition (A) can be appropriately determined according to the type of dichroic pigment used, but is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.1 to 12 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound. If the content of the dichroic pigment is within the above range, it is difficult to disrupt the orientation of the polymerizable liquid crystal compound, and a polarizer having a high degree of orientation order can be obtained.

[0146] In the present invention, the polymerizable liquid crystal composition (A) for forming a polarizer may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound, and a photopolymerization initiator is preferred in that it can initiate a polymerization reaction under lower temperature conditions. Specifically, a photopolymerization initiator capable of generating active radicals or acids by the action of light may be used, and among these, a photopolymerization initiator that generates radicals by the action of light is preferred. The polymerization initiator may be used alone or in combination of two or more types.

[0147] As photopolymerization initiators, known photopolymerization initiators may be used, and for example, photopolymerization initiators that generate active radicals include self-cleaving type photopolymerization initiators and hydrogen pulling type photopolymerization initiators.

[0148] As a self-cleavage type photopolymerization initiator, self-cleavage type benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. may be used. In addition, as a hydrogen-pulling type photopolymerization initiator, hydrogen-pulling type benzophenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosuverone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetphenone compounds, dialcoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, triazine compounds, etc. may be used.

[0149] Iodonium salts and sulfonium salts, etc., can be used as acid-generating photopolymerization initiators.

[0150] Among these, a reaction at a low temperature is desirable from the perspective of preventing the dissolution of the pigment, and a self-cleaving type photopolymerization initiator is desirable from the perspective of reaction efficiency at a low temperature, and in particular, acetophenone-based compounds, hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, and oxime ester-based compounds are preferred.

[0151] Specifically, the following can be cited as photopolymerization initiators.

[0152] Benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether;

[0153] Hydroxyacetophenone compounds such as oligomers of 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-hydroxycyclohexylphenylketone, and 2-hydroxy-2-methyl-1-〔4-(1-methylvinyl)phenyl〕propan-1-one;

[0154] α-aminoacetophenone compounds such as 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one;

[0155] Oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanol, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime);

[0156] Acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide;

[0157] Benzophenone compounds such as benzophenone, o-methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone;

[0158] Dialcocyacetophenone compounds such as diethoxyacetophenone;

[0159] 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 Triazine compounds such as 2,4-bis(trichloromethyl)-6-〔2-(3,4-dimethoxyphenyl)ethenyl〕-1,3,5-triazine. The photopolymerization initiator may be appropriately selected, for example, in relation to the polymerizable liquid crystal compound included in the polymerizable liquid crystal composition (A) from the above photopolymerization initiator.

[0160] In addition, commercially available photopolymerization initiators may be used. Commercially available photopolymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, and 369, 379, 127, 754, OXE01, OXE02, OXE03 (manufactured by BASF); Omnirad BCIM, Esacure 1001M, Esacure KIP160 (manufactured by IDM Resins BV); Shakeall (registered trademark) BZ, Z, and BEE (manufactured by Seiko Chemical Co., Ltd.); Kayacure (registered trademark) BP100 and UVI-6992 (manufactured by Dow Chemical Corporation); Examples include ADEKA Optoma SP-152, N-1717, N-1919, SP-170, ADEKA Acruz NCI-831, ADEKA Acruz NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A, and TAZ-PP (manufactured by Nippon Siebbelhegner Co., Ltd.); and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).

[0161] The content of the polymerization initiator in the polymerizable liquid crystal composition (A) is preferably 1 to 10 parts by mass, more preferably 1 to 8 parts by mass, even more preferably 2 to 8 parts by mass, and particularly preferably 4 to 8 parts by mass, with respect to 100 parts by mass of the polymerizable liquid crystal compound. If the content of the polymerization initiator is within the above range, the polymerization reaction of the polymerizable liquid crystal compound can be carried out without significantly disturbing the orientation of the polymerizable liquid crystal compound.

[0162] In the present invention, the polymerization rate of the polymerizable liquid crystal compound is preferably 60% or more, more preferably 65% ​​or more, and even more preferably 70% or more from the perspective of line contamination or handling during manufacturing.

[0163] In the present invention, it is preferable that the polarizer includes a leveling agent. That is, the polymerizable liquid crystal composition (A) for forming the polarizer preferably includes a leveling agent. The leveling agent has the function of adjusting the fluidity of the polymerizable liquid crystal composition (A) and making the coating film obtained by applying the polymerizable liquid crystal composition (A) flatter. Since the polarizer includes a leveling agent, it is difficult to cause non-uniformity in application even on curved surfaces of various shapes, particularly curved surfaces with relatively large curvature, and a smooth polarizer is obtained, which can be advantageous for improving the appearance and optical properties of the polarizer.

[0164] Specifically, surfactants may be used as leveling agents, and at least one selected from the group consisting of leveling agents with a polyacrylate compound as the main component and leveling agents with a fluorine atom-containing compound as the main component is preferred. Leveling agents may be used alone or in combination of two or more types.

[0165] Examples of leveling agents having polyacrylate compounds as the main component include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N", "BYK-361N", "BYK-380", "BYK-381", and "BYK-392" (BYK Chemie).

[0166] Leveling agents having fluorine atom-containing compounds as the main component include, for example, "Megapac (registered trademark) R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482", and "F-483" (DIC Corp.); "Surfron (registered trademark) S-381", "S-382", "S-383", "S-393", "SC-101", "SC-105", "KH-40", and "SA-100" (AGC Seimi Chemical Corp.); Examples include "E1830", "E5844" (Daikin Fine Chemical Research Institute Inc.); "F-Top EF301", "F-Top EF303", "F-Top EF351" and "F-Top EF352" (Mitsubishi Materials Electronics Co., Ltd.).

[0167] When the polymerizable liquid crystal composition (A) contains a leveling agent, the content thereof is preferably 0.05 to 5 parts by mass and more preferably 0.05 to 3 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound. If the content of the leveling agent is within the above range, it is easy to orient the polymerizable liquid crystal compound, and non-uniformity is less likely to occur, and a smoother polarizer tends to be obtained.

[0168] The polymerizable liquid crystal composition (A) may contain additives other than leveling agents. Examples of other additives include polymerizable non-liquid crystal compounds, photosensitizers, antioxidants, release agents, stabilizers, coloring agents such as bluening agents, flame retardants, and lubricants. When the polymerizable liquid crystal composition (A) contains other additives, the content of the other additives is preferably greater than 0% and less than or equal to 20 mass% with respect to the solid content of the polymerizable liquid crystal composition (A), and more preferably greater than 0% and less than or equal to 10 mass%.

[0169] The polymerization reaction of a polymerizable liquid crystal compound can be further promoted by incorporating a photosensitizer into a polymerizable liquid crystal composition (A). Examples of photosensitizers include xanthone compounds such as xanthones and thioxanthones (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxycyanthracene, etc.); phenothiazines and rubrene, etc. Photosensitizers may be used alone or in combination of two or more types.

[0170] When the polymerizable liquid crystal composition (A) includes a photosensitizer, the content thereof can be appropriately determined according to the type and amount of the polymerization initiator and the polymerizable liquid crystal compound, but 0.1 to 30 parts by mass is preferred, 0.5 to 10 parts by mass is more preferred, and 0.5 to 8 parts by mass is even more preferred per 100 parts by mass of the polymerizable liquid crystal compound.

[0171] The polymerizable liquid crystal composition (A) can be prepared by a conventionally known method for preparing a composition for forming a polarizer, and can typically be prepared by mixing and stirring a polymerizable liquid crystal compound, a dichroic pigment, and, if necessary, a polymerization initiator and the additives mentioned above. In addition, since compounds exhibiting smectic liquid crystal properties generally have high viscosity, viscosity adjustment may be performed by adding a solvent in order to improve the applicability of the polymerizable liquid crystal composition (A) and facilitate the formation of a polarizer.

[0172] The solvent used in the polymerizable liquid crystal composition (A) can be appropriately selected depending on the solubility of the polymerizable liquid crystal compound and dichroic pigment used. Specifically, examples include alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. These solvents may be used alone or in combination of two or more types. The content of the solvent is preferably 100 to 1900 parts by mass, more preferably 150 to 900 parts by mass, and even more preferably 180 to 600 parts by mass, based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition (A).

[0173] In the present invention, it is preferable that the polarizer be a polarizer with a high degree of orientational order. A polarizer with a high degree of orientational order yields Bragg peaks derived from higher-order structures, such as hexatic or crystalline phases, in X-ray diffraction measurements. A Bragg peak refers to a peak derived from a plane-period structure of molecular orientation. Therefore, it is preferable that the polarizer constituting the polarizer of the present invention exhibits Bragg peaks in X-ray diffraction measurements. That is, in the polarizer constituting the polarizer of the present invention, it is preferable that the polymerizable liquid crystal compound or its polymer be oriented such that the polarizer exhibits Bragg peaks in X-ray diffraction measurements, and it is more preferable that the molecules of the polymerizable liquid crystal compound are oriented in a "horizontal orientation" such that they are oriented in the direction of light absorption. In the present invention, a polarizer having a plane-period spacing of molecular orientation of 3.0 to 6.0 Å is preferred. A high degree of orientation order exhibiting Bragg peaks can be achieved by controlling the type of polymerizable liquid crystal compound used, the type and amount of dichroic pigment, and the type and amount of polymerization initiator.

[0174] A polarizer can be obtained by a method comprising, for example, forming a film of a polymerizable liquid crystal composition (A) on a photoalignment film formed on a curved substrate, removing a solvent from the film, phase transitioning a polymerizable liquid crystal compound into a liquid crystal phase (smectic phase), and polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal phase.

[0175] As a method for applying a polymerizable liquid crystal composition (A) onto a photoalignment film, it is preferable to adopt a coating method such as spin coating, spraying, or dip coating, in order to avoid causing non-uniformity in coating even on curved surfaces with relatively large curvature or concave shapes, and to obtain a uniform coating film of the polymerizable liquid crystal composition (A).

[0176] Next, a dried film is formed by removing the solvent by drying, etc., under conditions where the polymerizable liquid crystal compound included in the film obtained from the polymerizable liquid crystal composition (A) does not polymerize. Examples of drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying.

[0177] In addition, to phase transition the polymerizable liquid crystal compound into a liquid phase, the temperature is raised above the temperature at which the polymerizable liquid crystal compound transitions into a liquid phase, and then lowered, thereby phase transitioning the polymerizable liquid crystal compound into a liquid phase (smectic phase). This phase transition may be carried out after the removal of the solvent from the coating film, or simultaneously with the removal of the solvent.

[0178] By polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal state of the polymerizable liquid crystal compound, a polarizer is formed as a cured product of the polymerizable liquid crystal composition (A). Photopolymerization is preferred as the polymerization method. In photopolymerization, the light irradiated onto the dried film is appropriately selected according to the type of polymerizable liquid crystal compound contained in the dried film (in particular, the type of polymerizable group possessed by the polymerizable liquid crystal compound), the type of polymerization initiator, and the amount thereof. Specific examples include one or more active energy rays or active electron rays selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. Among these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction and can use a photopolymerization device that is widely used in the field, and it is preferable to select the type of polymerizable liquid crystal compound or polymerization initiator contained in the polymerizable liquid crystal composition (A) so that photopolymerization is possible by ultraviolet light. In addition, during polymerization, the polymerization temperature can be controlled by irradiating light while cooling the dried film with an appropriate cooling means. During photopolymerization, a patterned polarizing layer can be obtained by performing masking or developing.

[0179] Examples of light sources for the above active energy lines include, for instance, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, LED light sources emitting light in a wavelength range of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc.

[0180] The ultraviolet irradiation intensity is typically 10 to 3,000 mW / cm². The ultraviolet irradiation intensity is preferably an intensity in a wavelength range effective for activating the polymerization initiator. The time for irradiating light is typically 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. When irradiated once or multiple times with such ultraviolet irradiation intensity, the integrated amount of light is 10 to 3,000 mJ / cm², preferably 50 to 2,000 mJ / cm², and more preferably 100 to 1,000 mJ / cm².

[0181] By performing photopolymerization, the polymerizable liquid crystal compound is polymerized while maintaining a liquid crystal state, particularly a smectic phase, preferably a higher-order smectic phase, and a polarizer is formed. The polarizer obtained by polymerizing the polymerizable liquid crystal compound while maintaining a smectic liquid crystal state has the advantage of having high polarization performance compared to a conventional host-guest type polarizing film, that is, a polarizing layer formed in a nematic liquid crystal state, in conjunction with the action of the dichroic dye. In addition, it also has the advantage of having excellent strength compared to a coating of only a dichroic dye or a lyotropic liquid crystal.

[0182] The thickness of the polarizer can be appropriately selected according to the applied display device, preferably a film of 0.1 to 5 μm, more preferably 0.3 to 4 μm, and even more preferably 0.5 to 3 μm. If the film thickness of the polarizer is greater than or equal to the lower limit, it is easy to prevent the necessary light absorption from being obtained, and if it is less than or equal to the upper limit, it is easy to suppress the occurrence of alignment defects caused by a decrease in the alignment regulating force by the photo-alignment film.

[0183] When forming a polarizer, by applying a polymerizable liquid crystal composition (A) on an alignment film, it becomes easier to align the polymerizable liquid crystal compound and the dichroic pigment in a desired direction. The polarizer of the present invention uses a photoalignment film as an alignment film. By using a photoalignment film that allows the direction of the alignment regulating force to be arbitrarily controlled by selecting the polarization direction of the irradiated polarization, it is easy to obtain a high-quality alignment film by controlling the alignment angle with high precision, even in curved shapes where it is difficult to form an alignment film equipped with an alignment regulating force by physically changing the surface of an alignment film such as a rubbing alignment film, which is conventionally widely used as an alignment film, for example, curved surfaces with large curvature or concave curved surfaces, thus enabling the formation of a polarizer with higher alignment precision. In order to suppress the reduction of the alignment regulating force by the photoalignment film and sufficiently increase the alignment precision, in the polarizer of the present invention, the polarizer is typically laminated adjacent to the photoalignment film.

[0184] A photoalignment film is obtained by applying a composition (hereinafter referred to as a "composition for forming a photoalignment film") comprising a polymer, oligomer, or monomer having a photoreactive group (hereinafter also referred to as "polymer having a photoreactive group, etc.") and a solvent onto a curved substrate and irradiating it with polarized light (preferably polarized UV). If the polymer, etc. included in the composition for forming a photoalignment film has a reactive group (e.g., (meth)acryloyl group) identical to the polymerizable group of the polymerizable liquid crystal compound included in the polymerizable liquid crystal composition (A), the adhesion between the photoalignment film and the polarizer tends to be improved, which can be advantageous in suppressing the occurrence of lifting or delamination of the polarizer in a curved polarizer.

[0185] A photoreactive group refers to a group that induces liquid crystal orientation ability upon light irradiation. Specifically, it may include a group involved in photoreactions that are the origin of liquid crystal orientation ability, such as molecular orientation induction, isomerization, dimerization, photocrosslinking, or photodecomposition reactions, which occur due to light irradiation. Among these, a group involved in dimerization or photocrosslinking is preferred in that it exhibits excellent orientation. As a photoreactive group, a group having an unsaturated bond, particularly a double bond, is preferred, and a group having at least one selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond) is particularly preferred.

[0186] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azobenzene groups, azonaphthalene groups, aromatic heterocyclic azo groups, bis-azo groups, forma groups, and groups having an azoxybenzene structure. Examples of photoreactive groups having a C=O bond include benzophenone groups, coumarin groups, anthraquinone groups, and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and alkyl halide groups.

[0187] Among these, cinnamoyl groups and chalcone groups are preferred because they facilitate obtaining a photo-aligned film with excellent thermal stability and time-dependent stability, and the amount of polarized light irradiation required for photo-alignment is relatively low. Among polymers having photo-reactive groups, it is particularly preferable to have a cinnamoyl group in which the terminal portion of the polymer side chain forms a cinnamic acid structure.

[0188] The number average molecular weight of the polymer having photoreactive groups forming the photoalignment film is preferably 20,000 to 100,000, more preferably 22,000 or more, even more preferably 25,000 or more, and even more preferably 90,000 or less, and even more preferably 80,000 or less. If the number average molecular weight of the polymer having photoreactive groups is within the above range, the adhesion to the layer adjacent to the photoalignment film is easily improved, and a polarizing plate in which a curved substrate and a polarizer are laminated with good adhesion through the photoalignment film can be obtained. The number average molecular weight of the polymer having photoreactive groups can be controlled by the amount of monomer used in the composition for forming the photoalignment film, the type and amount of polymerization initiator, etc.

[0189] In addition, the “number average molecular weight of a polymer having a photoreactive group” mentioned here is substantially equivalent to the number average molecular weight of the polymer constituting the cured photoalignment film, and can be calculated by measuring the cured photoalignment film itself using a measuring instrument such as gel permeation chromatography.

[0190] A photo-alignment-inducing layer can be formed by applying a composition for forming a photo-alignment film, for example, onto a curved substrate. As for the solvent included in the composition, the same as the solvent previously exemplified as a solvent that can be used when forming a polarizer may be cited, and it may be appropriately selected according to the solubility of a polymer having a photoreactive group, etc.

[0191] The content of a polymer having a photoreactive group in the composition for forming a photoalignment film can be appropriately adjusted depending on the type of polymer or the thickness of the intended photoalignment film, but it is preferable to have at least 0.2 mass% with respect to the mass of the composition for forming a photoalignment film, and a range of 0.3 to 10 mass% is more preferable. Within a range where the properties of the photoalignment film are not significantly impaired, the composition for forming a photoalignment film may include polymer materials such as polyvinyl alcohol or polyimide or a photosensitizer.

[0192] A method for applying a composition for forming a photoalignment film onto a curved substrate and a method for removing a solvent from the applied composition for forming a photoalignment film may include the same method as applying a polymerizable liquid crystal composition (A) onto a photoalignment film and removing a solvent from the formed film.

[0193] Polarized light irradiation may be performed by directly irradiating polarized UV light onto a composition for forming a photoalignment film coated on a curved substrate from which the solvent has been removed, or by irradiating polarized light from the curved substrate side and transmitting the polarized light. Furthermore, it is particularly preferable that the polarized light be substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which photoreactive groups, such as polymers having photoreactive groups, can absorb light energy. Specifically, UV (ultraviolet) light in the wavelength range of 250 to 400 nm is particularly preferred. Light sources used for polarized light irradiation may include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferred. Among these, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are preferred because they have a high emission intensity of ultraviolet light at a wavelength of 313 nm. Polarized UV can be irradiated by passing light from the above light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as a Glen Thomson or Glen Taylor, or a wire grid type polarizer can be used.

[0194] In addition, if masking is performed when polarizing irradiation, multiple regions (patterns) with different liquid crystal alignment directions may be formed.

[0195] The thickness of the photoalignment film is preferably 10 to 5000 nm, more preferably 10 to 1000 nm, and even more preferably 30 to 300 nm. When the thickness of the photoalignment film is within the above range, good adhesion to the interface with the polarizer or the interface with the curved substrate can be exhibited, and an orientation regulating force can be exerted, and a polarizer can be formed with a high orientation order.

[0196] The polarizer of the present invention may include layers other than a curved substrate, a photoalignment film, and a polarizer, to the extent that it does not affect the effects of the present invention. Such other layers may include, for example, a protective layer intended to protect or reinforce the polarizer, a hard coat layer, a primer layer, or a pressure-sensitive adhesive layer.

[0197] The polarizing plate of the present invention is, for example,

[0198] (a) A process for forming a photo-alignment film on a curved substrate,

[0199] (b) a process of forming a coating of a polymerizable liquid crystal composition comprising at least one polymerizable liquid crystal compound and a dichroic pigment on a photoalignment film, and,

[0200] (c) A process of forming a polarizer by phase-transitioning the polymerizable liquid crystal compound included in the above polymerizable liquid crystal composition into a smectic liquid crystal phase, and then polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state.

[0201] It can be manufactured by a method including.

[0202] The above processes (a), (b), and (c) can each be carried out according to the methods described in the preceding paragraph as a method for forming a photoalignment film on a curved substrate, a method for forming a coating of a polymerizable liquid crystal composition (A), and a method for forming a polarizer from a coating of a polymerizable liquid crystal composition (A).

[0203] The present invention also targets an elliptical polarizer comprising a polarizer of the present invention and a phase difference layer having a quarter-wave plate function.

[0204] In the elliptical polarizer of the present invention, the phase difference layer is preferably a coating layer, and more preferably a cured product of a polymerizable liquid crystal composition comprising at least one polymerizable liquid crystal compound. If the phase difference layer is a coating layer, wrinkles or deformation are less likely to occur in the curved phase difference layer, and it is easier to form a phase difference layer capable of exhibiting high optical properties.

[0205] In the present invention, a phase difference layer having a quarter-wave plate function is the following formula (2):

[0206] 100 nm ≤ Re (550) ≤ 170 nm (2)

[0207] [In Equation (2), Re(λ) represents the in-plane phase difference value of the phase difference layer at wavelength λ nm]

[0208] It refers to a layer that satisfies the above equation (2). By satisfying the above equation (2), it becomes a phase difference layer that functions as a λ / 4 plate, and when an elliptical polarizer containing the phase difference layer is applied to an organic EL display device, etc., the effect of improving the front reflection color (effect of suppressing coloration) is likely to be increased. A more preferred range for the in-plane phase difference value of the phase difference layer is 130 nm ≤ Re (550) ≤ 150 nm.

[0209] Also, the phase difference layer is given by the following equations (3) and (4):

[0210] Re (450) / Re (550) ≤ 1.00 (3)

[0211] 1.00 ≤ Re (650) / Re (550) (4)

[0212] [In the formula, Re(λ) represents the in-plane phase difference value of the phase difference layer at wavelength λ nm]

[0213] It is desirable to satisfy [the following]. When the phase difference layer satisfies equations (3) and (4), the phase difference layer exhibits so-called inverse wavelength dispersion, in which the in-plane phase difference value at short wavelengths becomes smaller than the in-plane phase difference value at long wavelengths. An elliptical polarizer having such a phase difference layer tends to have excellent frontal color when mounted on an organic EL display device, etc. From the perspective of improving inverse wavelength dispersion and further enhancing the effect of improving the reflection color in the frontal direction of the elliptical polarizer, Re (450) / Re (550) is preferably 0.70 or higher, more preferably 0.78 or higher, and also preferably 0.92 or lower, more preferably 0.90 or lower, even more preferably 0.87 or lower, particularly preferably 0.86 or lower, and even more particularly preferably 0.85 or lower. Also, Re (650) / Re (550) is preferably 1.01 or higher, more preferably 1.02 or higher.

[0214] The above in-plane phase difference value can be adjusted by the film thickness d of the phase difference layer. Since the in-plane phase difference value is determined by the equation Re(λ) = (nx(λ) - ny(λ)) × d (where d represents the thickness of the target phase difference layer, nx represents the principal refractive index at wavelength λ nm in a direction parallel to the plane of the phase difference layer in the refractive index ellipsoid formed by the phase difference layer, and ny represents the refractive index at wavelength λ nm in a direction parallel to the plane of the phase difference layer and also orthogonal to the direction of nx in the refractive index ellipsoid formed by the phase difference layer), to obtain the desired in-plane phase difference value (Re(λ): in-plane phase difference value of the phase difference layer at wavelength λ (nm), the three-dimensional refractive index and the film thickness d need to be adjusted.

[0215] In the present invention, the polymerizable liquid crystal compound for forming the phase difference layer can be appropriately selected from polymerizable liquid crystal compounds conventionally known in the field of phase difference films, depending on the desired optical properties.

[0216] A polymerizable liquid crystal compound is a liquid crystal compound having polymerizable groups. Generally, polymerizable liquid crystal compounds include polymerizable liquid crystal compounds that exhibit positive wavelength dispersibility and polymerizable liquid crystal compounds that exhibit reverse wavelength dispersibility, wherein the polymer (cured product) obtained by polymerizing the polymerizable liquid crystal compound alone in a state oriented in a specific direction. In the present invention, only one type of polymerizable liquid crystal compound may be used, or a mixture of both types of polymerizable liquid crystal compounds may be used.

[0217] Examples of polymerizable liquid crystal compounds capable of forming a phase difference layer in the present invention include, for instance, the polymerizable liquid crystal compound described in Japanese Patent Publication No. 2011-207765.

[0218] A phase difference layer can be obtained by applying a polymerizable liquid crystal composition for forming a phase difference layer (hereinafter also referred to as "polymerizable liquid crystal composition (B)"), comprising a polymerizable liquid crystal compound, a solvent, and additives such as a polymerization initiator and a leveling agent as needed, onto a substrate or an alignment film, drying the film, and then aligning the polymerizable liquid crystal compound in the polymerizable liquid crystal composition (B), and subsequently polymerizing the polymerizable liquid crystal compound by light irradiation while maintaining the alignment state.

[0219] The solvent, polymerization initiator, and additives constituting the polymerizable liquid crystal composition (B) may be the same as those previously exemplified as the solvent, polymerization initiator, and additives that can be used in the polymerizable liquid crystal composition (A) that forms a polarizer.

[0220] From the perspective of easily imparting the desired orientation restriction force with high precision to various curved shapes, it is preferable that the alignment film used to form the phase difference layer be an optical alignment film. The optical alignment film or the method for forming the phase difference layer on the optical alignment film may be the same as the optical alignment film, method, and conditions exemplified in the method for forming a polarizer, and can be appropriately selected depending on the desired orientation restriction force or the configuration of the phase difference layer.

[0221] The thickness of the phase difference layer can be appropriately selected depending on the display device to which it is applied, but from the perspective of adhesion and thinning, it is preferably 0.1 to 5 μm, more preferably 0.2 to 4 μm, and even more preferably 0.4 to 3 μm.

[0222] The elliptical polarizer of the present invention is preferably formed such that a phase difference layer is directly formed on the polarizer of the present invention with an alignment layer interposed therebetween, or such that a polarizer is formed on a phase difference layer formed on a curved substrate with an alignment layer interposed therebetween, with a photo-alignment layer interposed therebetween. Instead of laminating the polarizer and the phase difference layer, which are manufactured separately, for example, by interposing a point adhesive layer, a phase difference layer is formed by applying a polymerizable liquid crystal composition (B) onto a curved polarizer, or a polarizer is formed by applying a polymerizable liquid crystal composition (A) onto a curved substrate on which the phase difference layer is formed. By doing so, when the polarizer and the phase difference layer of the present invention are laminated, the occurrence of wrinkles or deformation on the laminated surface of the curved shape is suppressed, thereby obtaining an elliptical polarizer with excellent external characteristics and optical characteristics. Accordingly, the elliptical polarizer of the present invention preferably does not include a point adhesive layer between the polarizer and the phase difference layer.

[0223] When stacking the polarizer and the phase difference layer of the present invention, it is preferable to stack them such that the ground axis (optical axis) of the phase difference layer and the absorption axis of the polarizer are substantially 45°. By stacking them such that the ground axis (optical axis) of the phase difference layer and the absorption axis of the polarizer are substantially 45°, the function of an elliptical polarizer can be obtained. Furthermore, substantially 45° is typically a range of 45 ± 5°.

[0224] The polarizing plate and elliptical polarizing plate of the present invention can be used in various display devices such as liquid crystal display devices or organic EL display devices, as well as in sunglasses, lens filters, etc. When using the polarizing plate and / or elliptical polarizing plate of the present invention for the above various applications, the polarizing plate and / or elliptical polarizing plate of the present invention, which is manufactured separately, may be mounted on various articles, or the polarizing plate and / or elliptical polarizing plate of the present invention may be manufactured by making the member constituting the various articles into a curved substrate and mounted as a component of the various articles.

[0225] The flexible image display device having an elliptical polarizer according to the present invention preferably further comprises a window and a touch panel touch sensor. The flexible image display device is, for example, composed of a laminate for the flexible image display device and an organic EL display panel, wherein the laminate for the flexible image display device is positioned on the viewing side relative to the organic EL display panel and configured to be foldable. The laminate for the flexible image display device may include, in addition to the elliptical polarizer of the present invention described above, a window, a touch panel touch sensor, etc. The stacking order thereof is arbitrary, but it is preferable that they be stacked in the order of a window, an elliptical polarizer, and a touch panel touch sensor from the viewing side, or in the order of a window, a touch panel touch sensor, and an elliptical polarizer.

[0226] It is desirable that an elliptical polarizer is present on the visible side of the touch panel touch sensor, as this makes it difficult to see the pattern of the touch panel touch sensor, thereby improving the visibility of the displayed image. Each component can be laminated using an adhesive, a pressure-sensitive adhesive, etc. Additionally, the laminate for the flexible image display device may have a light-blocking pattern formed on at least one surface of any one of the window, the elliptical polarizer, and the touch panel touch sensor.

[0227] A window is positioned on the viewing side of a flexible image display device and serves to protect other components from external impacts or environmental changes such as temperature and humidity. Conventionally, glass has been used as such a protective layer, but the window in a flexible image display device is not rigid and hard like glass, but has flexible characteristics. The window may be made of a flexible transparent substrate and may include a hard coating layer on at least one surface.

[0228] The above transparent substrate preferably has a visible light transmittance of 70% or more, and more preferably has a visible light transmittance of 80% or more. Any transparent polymer film may be used as the above transparent substrate. Among these, polyamide films, polyamideimide films or polyimide films, polyester films, olefin films, acrylic films, and cellulose films having excellent transparency and heat resistance are preferred. It is also preferable to disperse inorganic particles such as silica, organic fine particles, rubber particles, etc., within the polymer film.

[0229] The thickness of the above transparent substrate is preferably 5 to 200 μm, more preferably 20 to 100 μm.

[0230] A hard coat layer may be formed on at least one surface of the transparent substrate constituting the window. The thickness of the hard coat layer is not particularly limited and, for example, may be 2 to 100 μm. If the thickness of the hard coat layer is within the above range, it is easy to secure sufficient impact resistance, scratch resistance, and bending resistance.

[0231] The hard coat layer described above can be formed by curing a hard coat forming composition comprising a reactive material that forms a cross-linked structure by irradiating active energy rays or thermal energy, but curing by active energy rays is preferred. Active energy rays are defined as energy rays capable of decomposing compounds that generate active species to generate active species. Examples of active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, and electron beams, and ultraviolet rays are particularly preferred. The hard coat forming composition described above typically contains at least one compound of a radical polymerizable compound and a cation polymerizable compound, and a polymerization initiator. The radical polymerizable compound, the cation polymerizable compound, and the polymerization initiator are not particularly limited and may include those known in the past. The hard coat composition described above may further include one or more selected from the group consisting of solvents and additives. The above solvent may be any solvent known in the field of optical films as a solvent for a composition for forming a hard coat, provided that it is capable of dissolving or dispersing the above polymerizable compound or polymerization initiator. Examples of the above additives include inorganic particles, leveling agents, stabilizers, surfactants, antistatic agents, lubricants, antifouling agents, etc.

[0232] A touch panel touch sensor is used as an input means. Various types of touch panel touch sensors have been proposed, such as resistive, surface acoustic wave, infrared, electromagnetic induction, and capacitive methods, and any of these methods is acceptable. Among them, the capacitive method is preferred. A capacitive touch panel touch sensor is divided into an active area and an inactive area located at the outer edge of the active area. The active area is an area corresponding to the area where a screen is displayed on the display panel (display area), where a user's touch is detected, and the inactive area is an area corresponding to the area where a screen is not displayed on the display device (non-display area). The touch panel touch sensor may include a substrate having flexible characteristics; a sensing pattern formed in the active area of ​​the substrate; and each sensing line formed in the inactive area of ​​the substrate to be connected to an external driving circuit via the sensing pattern and a pad portion.

[0233] The substrate having flexible characteristics, the sensing pattern, and each sensing line are not particularly limited, and materials applicable in the relevant technical field can be selected for each.

[0234] As a substrate having flexible properties, for example, a substrate composed of the same material as the transparent substrate of the window can be used. For the substrate of the touch panel touch sensor, it is desirable for the toughness to be 2,000 MPa % or higher in terms of suppressing cracks in the touch panel touch sensor, and it is more desirable for the toughness to be 2,000 MPa % to 30,000 MPa %. Here, toughness is defined as the area under the curve to the fracture point in the stress (MPa)-strain (%) curve obtained through a tensile test of a polymer material.

[0235] Each layer (window, elliptical polarizer, touch panel touch sensor) forming the laminate for the flexible image display device can be formed by a pressure-sensitive adhesive. As the pressure-sensitive adhesive, general-purpose adhesives such as water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent volatilizing adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic-curing adhesives, active energy-curing adhesives, curing agent-mixed adhesives, heat-melting adhesives, pressure-sensitive adhesives (pressure-sensitive adhesives), and re-wetting adhesives can be used. Among these, water-based solvent volatilizing adhesives, active energy-curing adhesives, and pressure-sensitive adhesives are preferably used. The thickness of the pressure-sensitive adhesive layer can be appropriately adjusted according to the required adhesive strength, etc., but is typically 0.01 μm to 500 μm, preferably 0.1 μm to 300 μm. When multiple pressure-sensitive adhesive layers exist in the laminate for the flexible image display device described above, the type and thickness of the pressure-sensitive adhesive constituting each pressure-sensitive adhesive layer may be the same or different.

[0236] Examples

[0237] The present invention will be explained in more detail below through examples and comparative examples. In the examples and comparative examples, “%” and “parts” refer to “mass%” and “mass parts”, respectively, unless otherwise specifically stated.

[0238] 1. Example 1

[0239] (1) Preparation of a composition for forming an alignment film

[0240] A composition for forming a photoalignment film was obtained by mixing the following components and stirring the resulting mixture at 80°C for 1 hour.

[0241] · Polymers having the photoreactive groups shown below (number average molecular weight approx. 28,000) Part 2

[0242] [Chemical Formula 15]

[0243]

[0244] · Solvent: o-xylene 98 parts

[0245] (2) Preparation of a composition for forming a polarizer

[0246] A composition for forming a polarizer was obtained by mixing the following components and stirring at 80°C for 1 hour.

[0247] For the dichroic pigments, the following dichroic pigments (1), dichroic pigment (2), and dichroic pigment (3), as described in the example of Japanese Patent Publication No. 2013-101328, were used.

[0248] · 75 parts of polymerizable liquid crystal compounds represented by formula (1-6)

[0249] [Chemical Formula 16]

[0250]

[0251] · 25 parts of polymerizable liquid crystal compounds represented by formula (1-7)

[0252] [Chemical Formula 17]

[0253]

[0254] · Dichroic pigments shown below (1) 2.8 parts

[0255] [Chemical Formula 18]

[0256]

[0257] · Dichroic pigments shown below (2) 2.8 parts

[0258] [Chemical Formula 19]

[0259]

[0260] · Dichroic pigments shown below (3) 2.8 parts

[0261] [Chemical Formula 20]

[0262]

[0263] · Polymerization Initiator: 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals) 6 parts

[0264] · Leveling agent: Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) 1.2 parts

[0265] · Solvent: Cyclopentanone 250 parts

[0266] (3) Manufacturing of polarizing plates

[0267] A substrate that had undergone corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) on the surface of a glass concave lens (SLB-30-50N manufactured by Opto Sigma Co., Ltd.) was used as a curved substrate. After applying the above composition for forming a photoalignment film to the corona-treated surface using a spin coater, the mixture was dried for 1 minute in a drying oven set to 120°C to obtain a photoalignment film. A photoalignment film was formed on the photoalignment film by using a polarizing UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) to irradiate the lens with polarizing UV light at an integrated light amount of 50 mJ / cm² (based on 313 nm).

[0268] The composition for forming a polarizer was applied to the obtained photoalignment film using a spin coater, and then dried for 1 minute in a drying oven set to 110°C. After that, ultraviolet light was irradiated using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Electric Co., Ltd.) (under a nitrogen atmosphere, wavelength: 365 nm, integrated light intensity at wavelength 365 nm: 1000 mJ / cm²) to form a polarizer in which a polymerizable liquid crystal compound and a dichroic pigment were oriented, and a polarizing plate consisting of a curved substrate / photoalignment film / polarizer was obtained.

[0269] Regarding the obtained polarizer, it was confirmed that it has polarization performance by arranging it so that it is para-Nicol and cross-Nicol beyond a separate polarizer prepared by the method described in paragraph

[0321] of Japanese Patent Publication No. 2015-163935.

[0270] (4) Evaluation of stacked state

[0271] The lamination state of the obtained polarizer was checked visually. The results are shown in Table 1.

[0272] ○ : No wrinkles or uneven application are observed.

[0273] △ : Slight uneven application is observed.

[0274] × : Multiple wrinkles are observed.

[0275] 2. Example 2

[0276] A polarizer comprising a curved substrate, a photoalignment film, and a polarizer was obtained in the same manner as in Example 1, except that a substrate on which a corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) was performed on the surface of a glass concave lens (SLB-30-70N manufactured by Opto Sigma Co., Ltd.) was performed was used as the curved substrate. In the same manner as in Example 1, it was confirmed that the polarization performance was present, and the stacking state was evaluated. The results are shown in Table 1.

[0277] 3. Example 3

[0278] A polarizer comprising a curved substrate, a photoalignment film, and a polarizer was obtained in the same manner as in Example 1, except that a substrate on which a corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) was performed on the surface of a glass concave lens (SLB-30-100N manufactured by Opto Sigma Co., Ltd.) was performed was used as the curved substrate. In the same manner as in Example 1, it was confirmed that the polarization performance was present, and the stacking state was evaluated. The results are shown in Table 1.

[0279] 4. Example 4

[0280] A polarizer comprising a curved substrate, a photoalignment film, and a polarizer was obtained in the same manner as in Example 1, except that a substrate on which a corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) was performed on the surface of a glass concave lens (SLB-30-200N manufactured by Opto Sigma Co., Ltd.) was performed was used as the curved substrate. In the same manner as in Example 1, it was confirmed that the polarization performance was present, and the stacking state was evaluated. The results are shown in Table 1.

[0281] 5. Example 5

[0282] A polarizer comprising a curved substrate, a photoalignment film, and a polarizer was obtained in the same manner as in Example 1, except that a substrate having been corona-treated (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) on the surface of a glass convex lens (SLB-30-70P manufactured by Opto Sigma Co., Ltd.) was used as the curved substrate. In the same manner as in Example 1, it was confirmed that it possessed polarization performance, and the stacking state was evaluated. The results are shown in Table 1.

[0283] 6. Example 6

[0284] A polarizer comprising a curved substrate, a photoalignment film, and a polarizer was obtained in the same manner as in Example 1, except that a substrate having been corona-treated (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) on the surface of a glass convex lens (SLB-30-200P manufactured by Opto Sigma Co., Ltd.) was used as the curved substrate. In the same manner as in Example 1, it was confirmed that it possessed polarization performance, and the stacking state was evaluated. The results are shown in Table 1.

[0285] 7. Comparative Example 1

[0286] (1) Manufacturing of iodine PVA type polarizer

[0287] A polyvinyl alcohol film with a thickness of 30 μm (average degree of polymerization of about 2400, degree of saponification of 99.9 mol% or more) was uniaxially stretched by about 5 times by dry stretching, and then immersed in pure water at 40°C for 40 seconds while maintaining the tension. After that, a dyeing treatment was performed by immersing it in an aqueous dyeing solution with a mass ratio of iodine / potassium iodide / water of 0.044 / 5.7 / 100 at 28°C for 30 seconds. Next, it was immersed in an aqueous boric acid solution with a mass ratio of potassium iodide / boric acid / water of 11.0 / 6.2 / 100 at 70°C for 120 seconds. Next, after washing with pure water at 8°C for 15 seconds, the polarizer was dried at 60°C for 50 seconds and then at 75°C for 20 seconds while being held under a tension of 300 N / m, thereby obtaining a polarizer with a thickness of 12 μm in which iodine is adsorbed and oriented on a polyvinyl alcohol film.

[0288] A water-based adhesive was injected between the obtained polarizer and a cycloolefin film (ZF14 manufactured by Nippon Zeon Co., Ltd.) and laminated using a nip roll. The obtained laminate was dried at 60°C for 2 minutes while maintaining the tension of the laminate at 430 N / m to obtain an iodine PVA type polarizer having a cycloolefin film as a protective film on one side. In addition, the water-based adhesive was prepared by adding 3 parts of carboxyl group modified polyvinyl alcohol (Curarepoval KL318; manufactured by Curare Co., Ltd.) and 1.5 parts of water-soluble polyamide epoxy resin (Sumiresin 650; manufactured by Sumika Chemtex Co., Ltd., aqueous solution with a solid content concentration of 30%) to 100 parts of water.

[0289] A polarizer consisting of a curved substrate, an adhesive layer, and an iodine PVA type polarizer was obtained by performing the same procedure as in Example 3, except that the above iodine PVA type polarizer and the curved substrate used in Example 3 were bonded together with an adhesive (25 μm) manufactured by Lintec. In the same manner as in Example 1, it was confirmed that the polarizing performance was present, and the laminated state was evaluated. The results are shown in Table 1.

[0290] 8. Comparative Example 2

[0291] On the curved substrate used in Example 3, a 2 mass% aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industry Co., Ltd.) (composition for forming an alignment film) was applied by spin coating, and after drying, a film with a thickness of 100 nm was formed. Subsequently, an attempt was made to produce an alignment film by performing the following rubbing treatment on the surface of the obtained film, but due to the shape of the curved substrate, the rubbing treatment could not be performed sufficiently. In addition, the rubbing treatment was performed using a semi-automatic rubbing device (product name: LQ-008 type, manufactured by Joyo Engineering Co., Ltd.) and a cloth (product name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.) under conditions of an indentation amount of 0.15 mm, a rotation speed of 500 rpm, and 16.7 mm / s.

[0292] A composition for forming a polarizer was applied to the rubbing alignment film obtained by the above rubbing treatment in the same manner as in Example 1, and drying and polymerization were performed to obtain a polarizer comprising a curved substrate, a rubbing alignment film, and a polarizer. As in Example 1, the polarization performance was checked, and it was found to have no polarization performance. In addition, the stacking state was evaluated. The results are shown in Table 1.

[0293]

Claims

Claim 1 An elliptical polarizer comprising a polarizer having a curved shape including a curved substrate, a photoalignment film, and a polarizer in this order, and a phase difference layer having a quarter-wave plate function, wherein Equation (1): 20 mm ≤ R ≤ 300 mm (1) [wherein Equation (1) R represents the radius of curvature of the part with the smallest curvature in the polarizer], wherein the polarizer is composed of a cured product of a polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound having at least one polymerizable group and a dichroic pigment, wherein the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces in one direction with respect to the plane direction of the curve of the curved substrate on which the polarizer is stacked, and wherein the polarizer is not included in a point adhesive layer between the polarizer and the phase difference layer. Claim 2 In claim 1, an elliptical polarizer having a three-dimensional curved shape. Claim 3 In claim 1, an elliptical polarizer having a curved shape that is lens-like. Claim 4 An elliptical polarizer according to claim 1, wherein the polarizer further comprises a leveling agent. Claim 5 In claim 1, an elliptical polarizer in which the dichroic pigment is an azo pigment. Claim 6 In claim 1, an elliptical polarizer in which the polarizer exhibits a Bragg peak in X-ray analysis measurements. Claim 7 (a) a process of forming a photoalignment film on a curved substrate; (b) a process of forming a coating of a polymerizable liquid crystal composition comprising at least one polymerizable liquid crystal compound and a dichroic pigment on the photoalignment film; and (c) a process of forming a polarizer by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state after phase transitioning the polymerizable liquid crystal compound included in the polymerizable liquid crystal composition into a smectic liquid crystal state; and a process of forming a phase difference layer having a quarter-wave plate function, wherein the polymerizable liquid crystal compound is oriented such that the absorption axis of the polarizer faces in one direction with respect to the plane direction of the curve of the curved substrate on which the polarizer is stacked, and there is no point adhesive layer between the polarizer and the phase difference layer, and satisfies Equation (1): 20 mm ≤ R ≤ 300 mm (1) [wherein R represents the radius of curvature of the part with the smallest curvature in the polarizer]. Claim 8 A flexible image display device having an elliptical polarizer as described in any one of claims 1 to 6. Claim 9 A flexible image display device having additionally a window and a touch panel touch sensor in claim 8. Claim 10 delete Claim 11 delete

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