Composition for forming polarizing film and polarizing film

Abstract

To provide a polarizing film-forming composition which allows for forming a polarizing film which offers high adhesion to an alignment film and is difficult to peel off from the alignment film.SOLUTION: A polarizing film-forming composition is provided, comprising a reactive additive having both a polymerizable group and an active hydrogen reactive group, and a dichroic dye having a polymerizable group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming a polarizing film, a polarizing film, an optical laminate having the polarizing film, and methods for producing the polarizing film and the optical laminate. [Background technology]

[0002] In various image display panels such as liquid crystal display panels and organic electroluminescence (organic EL) display panels, a polarizing plate is attached to an image display element such as a liquid crystal cell or an organic EL display element. A known example of such a polarizing plate is one in which a protective layer such as a triacetyl cellulose film is laminated, via an adhesive layer, on at least one side of a polarizing film formed by adsorbing and aligning a dichroic compound such as iodine or a dichroic dye on a polyvinyl alcohol-based resin film.

[0003] In recent years, with the demand for thinner image display panels, there has been a demand for thinner polarizing plates that constitute the image display panels. Coating-type polarizing plates have been proposed as one type of thin polarizing plate. For example, Patent Document 1 discloses a polarizing plate having a polarizing film containing a polymerizable liquid crystal polymer and a dichroic dye. Furthermore, Patent Document 2 discloses a composition that can form a polarizing film, which contains a polymerizable liquid crystal compound exhibiting a smectic phase and a liquid crystal compound exhibiting dichroism. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-83843 [Patent Document 2] Japanese Patent Application Publication No. 2019-172987 Summary of the Invention [Problem to be solved by the invention]

[0005] Polarizing plates used in image display panels and the like are often used in the form of an optical laminate having an alignment film on at least one surface of a polarizing film. However, according to studies by the present inventors, it has been found that peeling may occur between the polarizing film and the alignment film in such an optical laminate.

[0006] Therefore, an object of the present invention is to provide a composition for forming a polarizing film that can form a polarizing film that has high adhesion to an alignment film and is unlikely to peel off from the alignment film. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention provides the following preferred embodiments. [1] A composition for forming a polarizing film, comprising a reactive additive having both a polymerizable group and an active hydrogen-reactive group, and a dichroic dye having a polymerizable group. [2] The composition for forming a polarizing film according to [1], further comprising a liquid crystal compound having a polymerizable group. [3] The following formula: {(A)+(B)} / (C)≧0.7 (A): Mass of dichroic dye having a polymerizable group (B): Mass of liquid crystal compound having a polymerizable group (C): Total mass of dichroic dye and liquid crystal compound The composition for forming a polarizing film according to [2], which satisfies the above. [4] The composition for forming a polarizing film according to any one of [1] to [3], further comprising a non-liquid crystal compound having a polymerizable group. [5] The composition for forming a polarizing film according to [4], wherein the non-liquid crystal compound has 3 to 6 polymerizable groups. [6] The composition for forming a polarizing film according to any one of [1] to [5], wherein the polymerizable group in the dichroic dye is a (meth)acryloyl group. [7] The composition for forming a polarizing film according to any one of [1] to [6], wherein the polymerizable group in the reactive additive is a (meth)acryloyl group. [8] The composition for forming a polarizing film according to [4] or [5], wherein the polymerizable group in the non-liquid crystal compound is a (meth)acryloyl group. [9] The composition for forming a polarizing film according to any one of [1] to [8], wherein the content of the reactive additive is 2 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the dichroic dye having a polymerizable group.

[10] A polarizing film which is a cured product of the polarizing film-forming composition according to any one of [1] to [9].

[11] A polarizing film formed from a cured product of the polarizing film-forming composition according to any one of [1] to [9], wherein a dichroic dye having a polymerizable group and / or a polymer thereof is oriented in a direction horizontal to the plane of the polarizing film.

[12] A polarizing film formed from a cured product of the composition for forming a polarizing film according to any one of [2] to [9], wherein a liquid crystal compound having a polymerizable group and / or a polymer thereof is oriented in a direction horizontal to the plane of the polarizing film.

[13] The polarizing film according to any one of

[10] to

[12] , which exhibits a Bragg peak in X-ray diffraction measurement.

[14] The polarizing film according to any one of

[10] to

[13] , which has a thickness of 0.1 to 10 μm.

[15] An optical laminate having an alignment film on at least one surface of the polarizing film according to any one of

[10] to

[14] .

[16] An optical laminate comprising an alignment film on one side of the polarizing film according to any one of

[10] to

[14] and a transparent thin film on the other side.

[17] The optical laminate according to either

[15] or

[16] , wherein the alignment film is an alignment film having a hydroxyl group.

[18] The optical laminate according to either

[15] or

[16] , wherein the alignment film has a poly(meth)acryloyl structure or a polysilazane structure.

[19] The optical laminate according to

[18] , wherein the alignment film further comprises a transparent substrate having an active hydrogen group on the side opposite to the polarizing film.

[20] The optical laminate according to

[18] or

[19] , wherein the alignment film has a thickness of 0.01 μm or more and 0.2 μm or less.

[21] A circularly polarizing plate comprising the optical laminate according to any one of

[15] to

[20] and a retardation film.

[22] A flexible panel comprising the circularly polarizing plate according to

[21] . 〔twenty three〕 (1) a step of applying the composition for forming a polarizing film according to any one of [1] to [9] onto a substrate having an alignment function; and (2) a step of curing the polarizing film-forming composition applied to the substrate; A method for producing a polarizing film, comprising: 〔twenty four〕 (a) forming an alignment film on a substrate; and (b) forming a polarizing film according to any one of

[10] to

[14] on an alignment film; A method for producing an optical laminate, comprising:

[25] The method for producing the optical laminate according to

[24] , further comprising the step of (c) forming a transparent thin film on the polarizing film. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a composition for forming a polarizing film that can form a polarizing film that has high adhesion to an alignment film and is unlikely to peel off from the alignment film. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0010] [Polarizing film forming composition] The polarizing film-forming composition of the present invention is a composition that forms a polarizing film upon curing, and contains at least a reactive additive having both a polymerizable group and an active hydrogen-reactive group, and a dichroic dye having a polymerizable group.

[0011] <Reactive additives> The polarizing film-forming composition of the present invention contains a reactive additive having both a polymerizable group and an active hydrogen-reactive group (hereinafter, also referred to simply as "reactive additive"), and thereby can form a polarizing film that has high adhesion to an alignment film. This effect is believed to be achieved because the polymerizable group and the active hydrogen-reactive group of the reactive additive bond to the polymerizable group of the dichroic dye in the polarizing film and the active hydrogen group of the alignment film, respectively, allowing the reactive additive to act as a linking agent that connects the polarizing film and the alignment film.

[0012] In the present invention, the polymerizable group means a group that is involved in a polymerization reaction. In the present invention, the polymerizable group is preferably a photopolymerizable group rather than a thermally polymerizable group. Examples of polymerizable groups in the reactive additive include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, (meth)acryloyl, (meth)acryloyloxy, oxiranyl, and oxetanyl groups. Among these, preferred polymerizable groups are (meth)acryloyl, (meth)acryloyloxy, vinyloxy, oxiranyl, and oxetanyl groups, more preferably (meth)acryloyl and (meth)acryloyloxy groups, and even more preferably (meth)acryloyloxy groups, from the viewpoint of ease of reaction control. The polymerizable groups in these reactive additives may be of one type alone or a combination of two or more types. In the present invention, "(meth)acryloyl" refers to methacryloyl and acryloyl.

[0013] The number of polymerizable groups contained in the reactive additive is not particularly limited and may be, for example, 1 to 20, but from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film, the number of polymerizable groups is preferably 2 or more, more preferably 2 to 15. When the reactive additive has two or more polymerizable groups, the polymerizable groups may be the same or different.

[0014] In the present invention, the "active hydrogen-reactive group" in the reactive additive refers to a group that is reactive with a group having active hydrogen (active hydrogen group), such as a carboxyl group (-COOH), a hydroxyl group (-OH), or an amino group (-NH). Examples of the active hydrogen-reactive group in the reactive additive include an epoxy group, a glycidyl group, an isocyanate group, a thioisocyanate group, an alkoxysilyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, and a maleic anhydride group. These active hydrogen-reactive groups may be used alone or in combination of two or more. Among these, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film, a preferred active hydrogen-reactive group is at least one active hydrogen-reactive group selected from the group consisting of an epoxy group, a glycidyl group, an isocyanate group, and an alkoxysilyl group. An alkoxysilyl group or an isocyanate group is more preferred, and an isocyanate group is even more preferred. Examples of the alkoxysilyl group include a trimethoxysilyl group, a triethoxysilyl group, a tripropoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a methoxydimethylsilyl group, etc. Among these, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film, preferred alkoxysilyl groups are a trimethoxysilyl group and a triethoxysilyl group, and a more preferred alkoxysilyl group is a trimethoxysilyl group.

[0015] The number of active hydrogen reactive groups contained in the reactive additive is not particularly limited and may be, for example, 1 to 20, but from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film, the number is preferably 2 or more, more preferably 2 to 10, and even more preferably 2 to 5. When the reactive additive has two or more active hydrogen reactive groups, the active hydrogen reactive groups may be the same or different.

[0016] In one embodiment of the present invention, the reactive additive is, from the viewpoints of easy reaction control and easy improvement of adhesion of the resulting polarizing film to the alignment film, preferably a compound having both at least one polymerizable group selected from the group consisting of a vinyl group and a (meth)acryloyl group and at least one active hydrogen-reactive group selected from the group consisting of an epoxy group, a glycidyl group, an isocyanate group, and an alkoxysilyl group, more preferably a compound having a (meth)acryloyl group and an isocyanate group or a compound having a (meth)acryloyl group and an alkoxysilyl group, and even more preferably a compound having a (meth)acryloyl group and an isocyanate group.

[0017] Specific examples of reactive additives include compounds having a (meth)acryloyl group and an epoxy group, such as methacryloxyglycidyl ether and acryloxyglycidyl ether; compounds having a (meth)acryloyl group and an oxetane group, such as oxetane acrylate and oxetane methacrylate; compounds having a (meth)acryloyl group and a lactone group, such as lactone acrylate and lactone methacrylate; compounds having a vinyl group and an oxazoline group, such as vinyloxazoline and isopropenyloxazoline; compounds having a (meth)acryloyl group and an isocyanate group, such as isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate; compounds having a (meth)acryloyl group and an alkoxysilyl group, such as 3-acryloyloxypropyltrimethoxysilane and 3-methacryloyloxypropylmethyldimethoxysilane, and oligomers of these compounds. Other specific examples of reactive additives include compounds having a vinyl group or vinylene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride. These reactive additives may be used alone or in combination of two or more. Specific reactive additives include methacryloxyglycidyl ether, acryloxyglycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyloxazoline, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, 3-acryloyloxypropyltrimethoxysilane, and oligomers thereof.

[0018] The content of the reactive additive is preferably 2 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the dichroic dye having a polymerizable group, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film. The content of the reactive additive is more preferably 5 parts by mass or more, even more preferably 15 parts by mass or more, and particularly preferably 30 parts by mass or more, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film. The content of the reactive additive is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, from the viewpoint of easily improving the alignment of the resulting polarizing film. The content of the reactive additive is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.9 parts by mass or more, and even more preferably 1 part by mass or more, relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, from the viewpoint of easily improving the alignment of the resulting polarizing film. In the present invention, the solid content of the composition for forming a polarizing film refers to the total amount of components excluding a solvent, which may be contained in the composition for forming a polarizing film, if any.

[0019] <Dichroic dye> The polarizing film-forming composition of the present invention contains a dichroic dye having a polymerizable group, which facilitates the formation of a polarizing film that has high adhesion to an alignment film. In the present invention, the dichroic dye refers to a dye that has different absorbance in the long axis direction and the short axis direction of the molecule. The polymerizable group in the dichroic dye can usually react with and bond to a polymerizable group in a reactive additive.

[0020] Examples of the polymerizable group in the dichroic dye include the groups exemplified as the polymerizable group in the reactive additive. Among these, from the viewpoint of ease of reaction control, preferred polymerizable groups are (meth)acryloyl group, (meth)acryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group, more preferably (meth)acryloyl group and (meth)acryloyloxy group, and even more preferably (meth)acryloyloxy group. The polymerizable group in the dichroic dye may be one type alone or a combination of two or more types, but it is preferably the same polymerizable group as the polymerizable group in the reactive additive.

[0021] The number of polymerizable groups contained in the dichroic dye is not particularly limited as long as it is at least 1. From the viewpoint of easily improving the alignment of the resulting polarizing film, the number of polymerizable groups is preferably 10 or less, for example, 5 or less, more preferably 3 or less, and even more preferably 2 or less.

[0022] The dichroic dye having a polymerizable group is preferably a dichroic dye having a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. The dichroic dye having a polymerizable group may be a non-liquid crystal compound, but is preferably a liquid crystal compound exhibiting liquid crystallinity from the viewpoint of easily improving the alignment of the resulting polarizing film. The dichroic dye having a polymerizable group may be a single type or a combination of two or more types.

[0023] In a preferred embodiment of the present invention, the dichroic dye having a polymerizable group is represented by the following formula (2): [ka] [In formula (2), m represents an integer of 0 to 3; A 1 , A 2 and A 3 each independently represents a divalent aromatic group which may have a substituent; L 1 and L 2are each independently a single bond, -CH2-, -CH2CH2-, -O-, -CH2O-, -OCH2-, -CO-, -COO-, -OCO-, -OCOO-, -CR c =CR d -, -C≡C-, -CR c =N-, -CONR c -, -NR c represents CO- or -N=N-, where R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Z 1 represents a polymerizable group, Z 2 represents a hydrogen atom or a polymerizable group; Q 1 and Q 2 each independently represents a linear or branched alkylene group having 1 to 20 carbon atoms which may have a substituent, an alkenylene group having 1 to 20 carbon atoms which may have a substituent, or an alkynylene group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in these alkylene groups, alkenylene groups, or alkynylene groups is -O-, -S-, or NR e -, where R e represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; T 1 is a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, or -CONR f - or -NR f CO- represents T 2 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -CONR f -, -NR f CO- or -NR g - where R f and R g are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R g The alkyl group represented by Q 1 or Q 2 A may form a ring with 1 -(L 1 -A2 ) m -L 2 -A 3 At least one -A X1 -N=NA X2 -(In the formula, A X1 and A X2 each represents a divalent aromatic group), and T 2 Ga-NR g -Z if 2 represents a hydrogen atom] The liquid crystal compound represented by formula (2) may be one type alone or a combination of two or more types.

[0024] In formula (2), m represents an integer of 0 to 3, and preferably represents an integer of 1 to 3.

[0025] In equation (2), A 1 , A 2 and A 3 each independently represents a divalent aromatic group which may have a substituent.

[0026] Examples of divalent aromatic groups include 1,4-phenylene, naphthalene-1,4-diyl, and optionally substituted divalent heterocyclic groups. Examples of divalent heterocyclic groups include groups obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. 2 When is a divalent heterocyclic group, a structure in which the molecular bond angle is substantially 180° is preferred, and specifically, a thienothiazole structure in which two five-membered rings are fused is more preferred.

[0027] Examples of substituents that the divalent aromatic group may have include alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, and butyl; alkoxy groups having 1 to 4 carbon atoms, such as methoxy, ethoxy, and butoxy; fluorinated alkyl groups having 1 to 4 carbon atoms, such as trifluoromethyl; cyano; nitro; halogen atoms, such as chlorine and fluorine; and substituted or unsubstituted amino groups, such as amino, diethylamino, and pyrrolidino. (A substituted amino group refers to an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or an amino group in which two substituted alkyl groups are bonded to form an alkanediyl group having 2 to 8 carbon atoms. An unsubstituted amino group is -NH.) Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl. Examples of the alkanediyl group having 2 to 8 carbon atoms include an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, and an octane-1,8-diyl group.

[0028] Specifically, the optionally substituted divalent aromatic group is preferably an unsubstituted 1,4-phenylene group or a 1,4-phenylene group in which hydrogen is substituted with a methyl group or a methoxy group, or the above-mentioned divalent heterocyclic group.

[0029] L 1 and L 2 are each independently a single bond, -CH2-, -CH2CH2-, -O-, -CH2O-, -OCH2-, -CO-, -COO-, -OCO-, -OCOO-, -CR c =CR d -, -C≡C-, -CR c =N-, -CONR c -, -NR c represents CO- or -N=N-. c and R d are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group.1 and L 2 is preferably —COO—, —CH═CH—, —C≡C—, —CONH—, or —N═N—, and among these, —COO—, —OCO—, or N═N— is particularly preferred.

[0030] Z 1 is a hydrogen atom or a polymerizable group, and Z 2 is a hydrogen atom or a polymerizable group. 1 and Z 2 When both are polymerizable groups, Z 1 and Z 2 may be the same or different, but are preferably the same type of polymerizable group, and more preferably the same polymerizable group. The polymerizable group may be in a polymerized state or an unpolymerized state, but is preferably in an unpolymerized state.

[0031] Z 1 and Z 2 Examples of the polymerizable group representing the formula (I) include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, a (meth)acryloyl group, a (meth)acryloyloxy group, an oxiranyl group, an oxetanyl group, etc. Among these, from the viewpoint of easy reaction control, preferred polymerizable groups are a (meth)acryloyl group, a (meth)acryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group, more preferably a (meth)acryloyl group and a (meth)acryloyloxy group, and even more preferably a (meth)acryloyloxy group.

[0032] Q 1 and Q 2 each independently represents a linear or branched alkylene group having 1 to 20 carbon atoms which may have a substituent, an alkenylene group having 1 to 20 carbon atoms which may have a substituent, or an alkynylene group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in these alkylene groups, alkenylene groups, or alkynylene groups is -O-, -S-, or NR e - may be substituted.

[0033] Examples of alkylene groups having 1 to 20 carbon atoms include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, octadecylene, nonadecylene, and eicosylene. Among these, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, and tetradecylene groups are preferred, and butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, and tridecylene groups are particularly preferred.

[0034] Examples of the alkenylene group having 1 to 20 carbon atoms include an ethenylene group, a propenylene group, a butenylene group, a pentenylene group, a hexenylene group, a heptenylene group, an octenylene group, a nonenylene group, a decenylene group, an undecenylene group, a dodecenylene group, a tridecenylene group, a tetradecenylene group, a pentadecenylene group, a hexadecenylene group, a heptadecenylene group, an octadecenylene group, a nonadecenylene group, and an eicosenylene group. , propenylene group, butenylene group, pentenylene group, hexenylene group, heptenylene group, octenylene group, nonenylene group, decenylene group, undecenylene group, dodecenylene group, tridecenylene group, and tetradecenylene group are preferred, and butenylene group, pentenylene group, hexenylene group, heptenylene group, octenylene group, nonenylene group, decenylene group, undecenylene group, dodecenylene group, and tridecenylene group are particularly preferred.

[0035] Examples of the alkynylene group having 1 to 20 carbon atoms include an ethynylene group, a propynylene group, a butynylene group, a pentynylene group, a hexynylene group, a heptynylene group, an octynylene group, a nonynylene group, a decynylene group, an undecynylene group, a dodecynylene group, a tridecynylene group, a tetradecynylene group, a pentadecynylene group, a hexadecynylene group, a heptadecynylene group, an octadecynylene group, a nonadecinylene group, and an eicosynylene group. , propynylene group, butynylene group, pentynylene group, hexynylene group, heptynylene group, octynylene group, nonynylene group, decynylene group, undecynylene group, dodecynylene group, tridecynylene group, and tetradecynylene group are preferred, and butynylene group, pentynylene group, hexynylene group, heptynylene group, octynylene group, nonynylene group, decynylene group, undecynylene group, dodecynylene group, and tridecynylene group are particularly preferred.

[0036] Examples of the substituent that the alkylene group, alkenylene group, or alkynylene group may have include a cyano group; and halogeno groups such as a fluoro group, a chloro group, or a bromo group. The alkylene group, alkenylene group, or alkynylene group is preferably an unsubstituted alkylene group, alkenylene group, or alkynylene group, and more preferably an unsubstituted linear alkylene group, alkenylene group, or alkynylene group.

[0037] Above R e represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. As mentioned above, examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, and a butyl group.

[0038] T 1 is a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, or -CONR f - or -NR f CO-. T 2 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -CONR f -, -NR f CO- or Z 2-NR only if is a hydrogen atom g - where R f and R g are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R g The alkyl group represented by Q 1 or Q 2 A may form a ring with 1 -(L 1 -A 2 ) m -L 2 -A 3 At least one -A X1 -N=NA X2 -(In the formula, A X1 and A X2 each represents a divalent aromatic group), and T 2 Ga-NR g -Z if 2 represents a hydrogen atom. X1 and A X2 The divalent aromatic group represented by the formula 1 and A 2 Examples of the divalent aromatic group include the same groups as those represented by the following formula:

[0039] In one embodiment of the present invention, examples of the compound represented by formula (2) include compounds represented by the following formulas (2-1) to (2-115). The compound represented by formula (2) is -A X1 -N=NA X2 -N=NA X3 -(In the formula, A X1 and A X2 are the same as the above definitions. A X3 represents a divalent aromatic group). X3 As the divalent aromatic group represented by A X1 and A X2 In one embodiment of the present invention, A X1 , A X2 and A X3is preferably a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a divalent aromatic heterocyclic group having 6 to 12 carbon atoms and containing a sulfur atom or a nitrogen atom. X1 , A X2 and A X3 At least one of them is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, such as a phenylene group or a naphthylene group. The compounds represented by the following formulae (2-1) to (2-115) may be used alone or in combination of two or more.

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] The compound represented by formula (2) can be produced by appropriately combining, depending on the structure, known organic synthesis reactions described in, for example, Methoden der Organischen Chemie, Organic Reactions, Organic Syntheses, Comprehensive Organic Synthesis, and New Experimental Chemistry Lectures (e.g., condensation reaction, esterification reaction, Williamson reaction, Ullmann reaction, Wittig reaction, Schiff base formation reaction, benzylation reaction, Sonogashira reaction, Suzuki-Miyaura reaction, Negishi reaction, Kumada reaction, Hiyama reaction, Buchwald-Hartwig reaction, Friedel-Crafts reaction, Heck reaction, and aldol reaction).

[0051] The content of the dichroic dye having a polymerizable group may be, for example, 1 to 99 parts by mass, preferably 2 parts by mass or more, and more preferably 3 parts by mass or more, relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film and the dichroic ratio; and from the viewpoint of easily improving the alignment of the resulting polarizing film, the content is preferably 80 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 25 parts by mass or less, and particularly preferably 10 parts by mass or less. The dichroic ratio is the ratio of the absorption intensities of two linearly polarized beams of light that vibrate perpendicularly to each other when they strike a polarizing film. It is defined as the ratio (AV / AH) of the absorbance (AV) along the extinction axis (measured at normal incidence) to the absorbance (AH) along the transmission axis. The transmission axis (polarization axis) refers to the polarization direction of the component of the light incident on the polarizing film that is transmitted through the film, while the extinction axis (absorption axis) refers to the polarization direction of the component of the light incident on the polarizing film that is absorbed by the film.

[0052] The polarizing film-forming composition of the present invention may contain a dichroic dye having no polymerizable group (hereinafter also referred to as a second dichroic dye) in addition to the dichroic dye having a polymerizable group (hereinafter also referred to as a first dichroic dye), as long as the effects of the present invention are not impaired.

[0053] The second dichroic dye is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes. Among these, azo dyes are preferred, and examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred. The second dichroic dye may be used alone or in combination of two or more.

[0054] When the polarizing film-forming composition of the present invention contains a second dichroic dye in addition to a first dichroic dye, the content of the first dichroic dye is preferably 30% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, based on the total amount of dichroic dyes (the total amount of the first dichroic dye and the second dichroic dye). When the content of the first dichroic dye is equal to or greater than the lower limit, the proportion of the dichroic dye that can react with the polymerizable group in the reactive additive increases, which tends to improve the adhesion of the resulting polarizing film to the alignment film. The upper limit of the content is not particularly limited and may be 100% by mass or less.

[0055] Furthermore, when the polarizing film-forming composition of the present invention contains a second dichroic dye in addition to a first dichroic dye as a dichroic dye, the total amount of dichroic dyes contained in the polarizing film-forming composition (the total amount of the first dichroic dye and the second dichroic dye) may be, for example, more than 1 part by mass and not more than 99 parts by mass, relative to 100 parts by mass of the solid content of the polarizing film-forming composition. From the viewpoint of easily increasing the dichroic ratio of the resulting polarizing film, the total amount is preferably more than 2 parts by mass, more preferably more than 3 parts by mass. Furthermore, from the viewpoint of easily increasing the alignment of the resulting polarizing film, the total amount is preferably not more than 80 parts by mass, more preferably not more than 50 parts by mass, even more preferably not more than 25 parts by mass, and particularly preferably not more than 10 parts by mass.

[0056] <Liquid crystal compounds> In addition to the reactive additive and the dichroic dye, the polarizing film-forming composition of the present invention preferably further contains a liquid crystal compound having a polymerizable group, from the viewpoint of easily improving the adhesion of the resulting polarizing film to the alignment film and easily increasing the alignment. The liquid crystal compound refers to a compound that exhibits liquid crystallinity. Note that the liquid crystal compound having a polymerizable group in the present invention does not include a dichroic dye having a polymerizable group.

[0057] Examples of the polymerizable group in the liquid crystal compound include the groups exemplified as the polymerizable group in the reactive additive. Among these, from the viewpoint of easy reaction control, preferred polymerizable groups are (meth)acryloyl group, (meth)acryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group, more preferably (meth)acryloyl group and (meth)acryloyloxy group, and even more preferably (meth)acryloyloxy group. The polymerizable group in the liquid crystal compound may be one type alone or a combination of two or more types, but it is preferable that it is the same polymerizable group as the polymerizable group in the reactive additive and the polymerizable group in the dichroic dye.

[0058] The liquid crystal compound having a polymerizable group may be a thermotropic liquid crystal or a lyotropic liquid crystal, but is preferably a thermotropic liquid crystal. The liquid crystal compound having a polymerizable group may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. In the present invention, the liquid crystal compound having a polymerizable group is preferably a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase, more preferably a thermotropic liquid crystal compound exhibiting a higher-order smectic liquid crystal phase, from the viewpoint of obtaining higher polarization characteristics. Among these, thermotropic liquid crystal compounds exhibiting a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase are more preferred, and thermotropic liquid crystal compounds exhibiting a smectic B phase, a smectic F phase, or a smectic I phase are even more preferred. When the liquid crystal phase formed by a liquid crystal compound having a polymerizable group is a higher-order smectic phase, a polarizing film with higher polarization performance can be easily obtained. Furthermore, such polarizing films with high polarization performance exhibit Bragg peaks derived from higher-order structures such as hexatic and crystalline phases in X-ray diffraction measurements. These Bragg peaks are derived from the periodic structure of molecular orientation, and films with periodic intervals of 3 to 6 Å can be obtained. The polarizing film of the present invention preferably contains a polymer of polymerizable liquid crystal obtained by polymerizing the polymerizable liquid crystal in a smectic phase, from the viewpoint of obtaining higher polarization performance.

[0059] In one embodiment of the present invention, the liquid crystal compound having a polymerizable group is represented by the following formula (1): [ka] [In formula (1), X 1 and X 2represent, independently of each other, a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a 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, with the proviso that X 1 , X 2 at least one of which is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group; n is 1 to 3, and from the viewpoint of liquid crystal properties, n is preferably 2 or more. When n is 2 or more, X 1 , X 2 may be the same or different; Y 1 are, independently of each other, a single bond or a divalent linking group; U 1 represents a hydrogen atom or a polymerizable group; U 2 represents a polymerizable group; W 1 and W 2 are, independently of each other, a single bond or a divalent linking group; V 1 and V 2 each independently represents an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH2- constituting the alkanediyl group may be replaced by -O-, -CO-, -S- or -NH-. Compound (1) may be a compound represented by the formula: 1 -(X 1 -Y 1 ) n -X 2 -W 2 But, -A X1 -N=NA X2 -(A X1 and A X2and each represent a divalent aromatic group.) The compound represented by formula (1) may be used alone or in combination of two or more kinds.

[0060] In the compound represented by formula (1), X 1 , X 2 represent, independently of each other, a divalent aromatic group or a divalent alicyclic hydrocarbon group which may have a substituent, provided that X 1 , X 2 At least one of the X's represents an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group. 1 , X 2 are each independently an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, more preferably a trans-cyclohexane-1,4-diyl group. The optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group may optionally have a substituent, such as an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or a butyl group; a cyano group; or a halogen atom, such as a chlorine atom or a fluorine atom, and preferably unsubstituted. In addition, in formula (1), when n is 2 or more and Y 1 If X is the same structure, 1 , X 2 It is preferable that n is 2 or more and at least one of X 1 , X 2 When at least one of the structures is different, smectic liquid crystallinity tends to be easily exhibited.

[0061] Y 1 are each independently a single bond or a divalent linking group. Divalent linking groups include -CH2CH2-, -CHO-, -CH2CH2O-, -COO-, -OCOO-, -N=N-, and -CR a =CR b -, -C≡C-, -CR a =N- or -CO-NR a - is preferred.a and R b are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 1 is more preferably -CH2CH2-, -COO- or a single bond, and Y 2 is more preferably -CH2CH2- or CH2O-. In addition, in formula (1), n ​​is 2 or more and X 1 , X 2 If all have the same structure, Y 1 It is preferable that n is 2 or more and Y are bonded in different ways. 1 When the bonding modes are different from each other, smectic liquid crystallinity tends to be easily exhibited.

[0062] U 2 is a polymerizable group. 1 is a hydrogen atom or a polymerizable group, preferably a polymerizable group. 1 and U 2 are preferably both polymerizable groups, and both are preferably radically polymerizable groups. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloyloxy group is more preferred. U 1 and a polymerizable group represented by U 2 The polymerizable groups represented by may be different from each other, but are preferably the same type of group. The polymerizable groups may be in a polymerized state or an unpolymerized state, but are preferably in an unpolymerized state.

[0063] V 1 and V 2each independently represents an alkanediyl group having 1 to 20 carbon atoms, which may have a substituent, and -CH2- constituting the alkanediyl group may be replaced with -O-, -CO-, -S-, or NH-. Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, and an icosane-1,20-diyl group. V 1 and V 2 is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0064] Examples of the substituent that the alkanediyl group may optionally have include a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted linear alkanediyl group.

[0065] W 1 and W 2 are each independently a single bond or a divalent linking group. 1 and W 2 is preferably —O—, —S—, —COO— or —OCOO—, and more preferably a single bond or —O—.

[0066] The liquid crystal compound having a polymerizable group is not particularly limited as long as it has at least one polymerizable group and exhibits liquid crystallinity, and known polymerizable liquid crystal compounds can be used. As the liquid crystal compound having a polymerizable group, a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity is preferred, and a compound exhibiting higher-order smectic liquid crystallinity is more preferred. The structure that readily exhibits smectic liquid crystallinity preferably has an asymmetric molecular structure within the molecular structure, and more specifically, a polymerizable liquid crystal compound having a structure represented by the following formulas (Aa) to (Ai) that exhibits smectic liquid crystallinity is more preferred. From the viewpoint of readily exhibiting higher-order smectic liquid crystallinity, a structure represented by any of formulas (Aa), (Ab), and (Ac) is more preferred, and a structure represented by formula (Aa) or (Ac) is particularly preferred. In the following formulas, * represents a bond.

[0067] [ka]

[0068] In one embodiment of the present invention, examples of the compound represented by formula (1) include compounds represented by formulas (1-1) to (1-25). When the compound represented by formula (1) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably in a trans form.

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] Among these, at least one selected from the group consisting of compounds represented by formula (1-2), formula (1-3), formula (1-4), formula (1-5), formula (1-6), formula (1-7), formula (1-8), formula (1-13), formula (1-14), formula (1-15), formula (1-16) and formula (1-17) is preferred. The compound represented by formula (1) may be used alone or in combination of two or more.

[0075] The compound represented by formula (1) can be produced by known methods, for example, as described in Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156.

[0076] When the composition for forming a polarizing film of the present invention contains a liquid crystal compound having a polymerizable group, the content of the liquid crystal compound may be, for example, 1 to 99 parts by mass relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, and is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 60 parts by mass or more, still more preferably 70 parts by mass or more, particularly preferably 80 parts by mass or more, and is preferably 98 parts by mass or less, more preferably 95 parts by mass or less.

[0077] When the composition for a polarizing film of the present invention contains a liquid crystal compound having a polymerizable group, the total amount of the dichroic dye having a polymerizable group and the liquid crystal compound having a polymerizable group is preferably at least 50 parts by mass, more preferably at least 70 parts by mass, and even more preferably at least 80 parts by mass, relative to 100 parts by mass of the solids content of the composition for forming a polarizing film, and is preferably at most 100 parts by mass, more preferably at most 98 parts by mass, and even more preferably at most 95 parts by mass. When the total amount of the dichroic dye having a polymerizable group and the liquid crystal compound having a polymerizable group is at least the above-mentioned lower limit and is at most the above-mentioned upper limit, the orientation of the resulting polarizing film is likely to be improved.

[0078] The composition for forming a polarizing film of the present invention may further contain a liquid crystal compound having no polymerizable group (hereinafter also referred to as a second liquid crystal compound) in addition to the liquid crystal compound having the above-mentioned polymerizable group (hereinafter also referred to as a first liquid crystal compound), as long as the effect of the present invention is not impaired.

[0079] The second liquid crystal compound is not particularly limited, and examples thereof include compounds represented by the formula (1) in which U 1 and U 2 and the like, for example, a compound represented by formula (1) in which both of

[0080] When the polarizing film-forming composition of the present invention contains a second liquid crystal compound in addition to a first liquid crystal compound as liquid crystal compounds, the content of the first liquid crystal compound is preferably 30% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, based on the total amount of liquid crystal compounds (the total amount of the first liquid crystal compound and the second liquid crystal compound). When the content of the first liquid crystal compound is equal to or greater than the above-mentioned lower limit, the proportion of liquid crystal compounds that can react with the polymerizable group in the reactive additive increases, which tends to improve the adhesion of the resulting polarizing film to the alignment film. The upper limit of the content is not particularly limited and may be 100% by mass or less.

[0081] When the polarizing film-forming composition of the present invention contains a second liquid crystal compound in addition to a first liquid crystal compound as liquid crystal compounds, the total amount of the liquid crystal compounds contained in the polarizing film-forming composition (the total amount of the first liquid crystal compound and the second liquid crystal compound) may be, for example, more than 1 part by mass and not more than 99 parts by mass, preferably more than 20 parts by mass, more preferably more than 40 parts by mass, even more preferably more than 60 parts by mass, even more preferably more than 70 parts by mass, particularly preferably more than 80 parts by mass, and is also preferably not more than 98 parts by mass, more preferably not more than 95 parts by mass, per 100 parts by mass of the solid content of the polarizing film-forming composition.

[0082] <Non-liquid crystal compounds> The polarizing film-forming composition of the present invention may further contain a non-liquid crystal compound having a polymerizable group in addition to the reactive additive, dichroic dye, and optionally a liquid crystal compound. When the polarizing film-forming composition of the present invention further contains a non-liquid crystal compound having a polymerizable group, the film strength of the resulting polarizing film is likely to be improved. Examples of the polymerizable group include the same groups as those exemplified as the polymerizable groups of the reactive additive. Among these, preferred polymerizable groups, from the viewpoint of ease of reaction control, are (meth)acryloyl, (meth)acryloyloxy, vinyloxy, oxiranyl, and oxetanyl groups, more preferably (meth)acryloyl and (meth)acryloyloxy groups, and even more preferably (meth)acryloyloxy groups. The polymerizable group in the non-liquid crystal compound may be a single type or a combination of two or more types, but is preferably the same polymerizable group as the polymerizable group in the dichroic dye or liquid crystal compound.

[0083] The number of polymerizable groups that the non-liquid crystal compound has is not particularly limited and may be, for example, 1 to 20. From the viewpoint of making it easier to increase the film strength of the resulting polarizing film, the number is preferably 2 to 10, and more preferably 3 to 6. When the non-liquid crystal compound has two or more polymerizable groups, the polymerizable groups may be the same as or different from each other.

[0084] The non-liquid crystal compound having a polymerizable group is preferably a compound that does not have coloration or absorption of visible light in itself, has compatibility that allows it to be uniformly mixed with a dichroic dye having a polymerizable group and a liquid crystal compound having a polymerizable group as needed, and does not inhibit the formation of a liquid crystal state exhibited by the dichroic dye having a polymerizable group and a liquid crystal compound having a polymerizable group as needed. The non-liquid crystal compound may be a single compound or a combination of two or more compounds.

[0085] Examples of non-liquid crystal compounds having a polymerizable group include monofunctional (meth)acrylates and polyfunctional (meth)acrylates. Since monofunctional acrylates and polyfunctional acrylates as non-liquid crystal compounds having a polymerizable group are non-liquid crystal, those that do not have a mesogenic structure are preferred. Furthermore, the monofunctional acrylates and polyfunctional acrylates may contain a urethane structure, an amino structure, an epoxy structure, an ethylene glycol structure, or a polyester structure in the molecule. In the present invention, "(meth)acrylate" refers to methacrylate and acrylate.

[0086] Examples of the monofunctional (meth)acrylate include alkyl (meth)acrylates having 4 to 16 carbon atoms, β-carboxyalkyl (meth)acrylates having 2 to 14 carbon atoms, alkylated phenyl (meth)acrylates having 2 to 14 carbon atoms, methoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, and isobornyl (meth)acrylate.

[0087] As the polyfunctional (meth)acrylate, di- to hexafunctional (meth)acrylates are preferred. Examples of bifunctional (meth)acrylates include 1,3-butanediol di(meth)acrylate; 1,6-hexanediol di(meth)acrylate; ethylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate; neopentyl glycol di(meth)acrylate; triethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol diacrylate; bis(acryloyloxyethyl)ether of bisphenol A; ethoxylated bisphenol A di(meth)acrylate; propoxylated neopentyl glycol di(meth)acrylate; ethoxylated neopentyl glycol di(meth)acrylate, and 3-methylpentanediol di(meth)acrylate.

[0088] Examples of tri- to hexafunctional acrylates include trimethylolpropane tri(meth)acrylate; pentaerythritol tri(meth)acrylate; tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate; ethoxylated trimethylolpropane tri(meth)acrylate; propoxylated trimethylolpropane tri(meth)acrylate; pentaerythritol tetra(meth)acrylate; dipentaerythritol penta(meth)acrylate; dipentaerythritol hexa(meth)acrylate; tripentaerythritol tetra(meth)acrylate; Tripentaerythritol penta(meth)acrylate;Tripentaerythritol hexa(meth)acrylate;Tripentaerythritol hepta(meth)acrylate;Tripentaerythritol octa(meth)acrylate;Reaction products of pentaerythritol tri(meth)acrylate with acid anhydrides;Reaction products of dipentaerythritol penta(meth)acrylate with acid anhydrides;Reaction products of tripentaerythritol hepta(meth)acrylate with acid anhydrides;Caprolactone-modified trimethylolpropane tri(meth)acrylate Acrylate;Caprolactone-modified pentaerythritol tri(meth)acrylate;Caprolactone-modified tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate;Caprolactone-modified pentaerythritol tetra(meth)acrylate;Caprolactone-modified dipentaerythritol penta(meth)acrylate;Caprolactone-modified dipentaerythritol hexa(meth)acrylate;Caprolactone-modified tripentaerythritol tetra(meth)acrylate;Caprolactone-modified tripentaerythritol penta(meth)acrylate acrylate; caprolactone-modified tripentaerythritol hexa(meth)acrylate; caprolactone-modified tripentaerythritol hepta(meth)acrylate; caprolactone-modified tripentaerythritol octa(meth)acrylate; a reaction product of caprolactone-modified pentaerythritol tri(meth)acrylate with an acid anhydride; a reaction product of caprolactone-modified dipentaerythritol penta(meth)acrylate with an acid anhydride, and a reaction product of caprolactone-modified tripentaerythritol hepta(meth)acrylate with an acid anhydride.Furthermore, caprolactone-modified means that a ring-opened product or ring-opened polymer of caprolactone is introduced between the alcohol-derived moiety and the (meth)acryloyloxy group of the (meth)acrylate compound.

[0089] When the composition for forming a polarizing film of the present invention contains a non-liquid crystal compound having a polymerizable group, the content of the non-liquid crystal compound is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.8 parts by mass or more, relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoint of easily increasing the film strength of the resulting polarizing film; and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, from the viewpoint of easily increasing the alignment property of the resulting polarizing film.

[0090] <Polymerization initiator> The polarizing film-forming composition of the present invention may further contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of compounds having a polymerizable group contained in the polarizing film-forming composition (the reactive additive and the dichroic dye having a polymerizable group, and the liquid crystal compound having a polymerizable group and the non-liquid crystal compound having a polymerizable group that are optionally contained). The polymerization initiator is not particularly limited as long as it is a compound capable of initiating a polymerization reaction of a compound having a polymerizable group, and known photopolymerization initiators can be used. Specific examples include photopolymerization initiators that generate active radicals upon irradiation with light, and photopolymerization initiators that generate acids. The photopolymerization initiators can be used alone or in combination of two or more.

[0091] Examples of photopolymerization initiators that generate active radicals include self-cleavage type photopolymerization initiators such as benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, and azo compounds, and hydrogen abstraction type photopolymerization initiators such as benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzil ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, and triazine compounds. Examples of photopolymerization initiators that generate an acid include iodonium salts and sulfonium salts. Among these photopolymerization initiators, photopolymerization initiators that generate active radicals upon irradiation with light are preferred, and among these, self-cleavage type photopolymerization initiators are preferred from the viewpoint of excellent reaction efficiency at low temperatures, and acetophenone-based compounds, hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, and oxime ester-based compounds are particularly preferred.

[0092] Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0093] Examples of acetophenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one.

[0094] Examples of oxime ester compounds include 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime).

[0095] Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0096] Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

[0097] Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one.

[0098] Examples of triazine compounds include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine. )-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, 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine, and the like.

[0099] Examples of polymerization initiators include Irgacure 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, and Irgacure 369 (all manufactured by Chiba Japan Co., Ltd.), Seikuol BZ, Seikuol Z, and Seikuol BEE (all manufactured by Seiko Chemical Co., Ltd.), Kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow Chemical), Adeka Optomer SP-152 or Adeka Optomer SP-170 (all manufactured by ADEKA Corporation), TAZ-A and TAZ-PP (manufactured by Nippon SiberHegner), TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.), Esacure One, and Esacure KIP 150 (all manufactured by IGM Commercially available photopolymerization initiators such as those manufactured by Resins Co., Ltd. can also be used.

[0100] When the polarizing film-forming composition of the present invention contains a polymerization initiator, the content of the polymerization initiator may be appropriately adjusted depending on the type and amount of a compound having a polymerizable group that is involved in the polymerization reaction and is contained in the polarizing film-forming composition. The content of the polymerization initiator is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the solid content of the polarizing film-forming composition.

[0101] <Other additives> The polarizing film-forming composition of the present invention may contain other additives as needed, as long as the effects of the present invention are not impaired. Examples of other additives include sensitizers, polymerization inhibitors, and leveling agents.

[0102] (sensitizer) The polarizing film-forming composition may contain a sensitizer. The sensitizer is preferably a photosensitizer. Examples of the sensitizer include xanthone compounds such as xanthone or thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.), anthracene compounds having a substituent such as an alkyl ether (e.g., dibutoxyanthracene, etc.), phenothiazine, and rubrene.

[0103] When the composition for forming a polarizing film contains a sensitizer, the polymerization reaction of the compounds having a polymerizable group contained in the composition (the reactive additive and the dichroic dye having a polymerizable group, and the liquid crystal compound having a polymerizable group and the non-liquid crystal compound having a polymerizable group that are optionally contained) is promoted, which makes it easier to improve the film strength of the resulting polarizing film.

[0104] When the composition for forming a polarizing film of the present invention contains a photosensitizer, the content of the sensitizer is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 8.0 parts by mass relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoint of easily promoting the polymerization reaction without impairing the alignment of the resulting polarizing film.

[0105] (polymerization inhibitor) Examples of the polymerization inhibitor include hydroquinone or hydroquinones having a substituent such as alkyl ether, catechols having a substituent such as alkyl ether, such as butylcatechol, pyrogallols, radical scavengers such as 2,2,6,6-tetramethyl-1-piperidinyloxy radical, thiophenols, β-naphthylamines, and β-naphthols.

[0106] When the polarizing film-forming composition of the present invention contains a polymerization inhibitor, it can be polymerized without disturbing the alignment of the dichroic dye having a polymerizable group and the liquid crystal compound optionally containing a polymerizable group. When the composition for forming a polarizing film of the present invention contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 8.0 parts by mass relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoint of enabling polymerization to be carried out without disturbing the alignment of the dichroic dye having a polymerizable group and the liquid crystal compound optionally contained having a polymerizable group.

[0107] (Leveling agent) The polarizing film-forming composition may contain a leveling agent, which is an additive that adjusts the fluidity of the composition and makes the film obtained by applying the composition flatter, and examples of such leveling agents include organically modified silicone oil-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all manufactured by Momentive Performance Materials) Japan LLC), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Limited), Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479, F-482, F-483 (all manufactured by DIC Corporation), F-top (trade name) EF301, EF303, Examples of suitable leveling agents include EF351 and EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade names E1830 and E5844 (manufactured by Daikin Fine Chemical Research Institute Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353, and BYK-361N (all trade names manufactured by BM Chemie). Among these, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferred.

[0108] When the composition for forming a polarizing film of the present invention contains a leveling agent, the amount thereof is preferably 0.01 to 30 parts by mass, more preferably 0.03 to 10 parts by mass, and even more preferably 0.05 to 8.0 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a polarizing film, from the viewpoints of improving alignment and making it easier to smooth the resulting polarizing film. The composition for forming a polarizing film may contain one or more leveling agents.

[0109] <Solvent> From the viewpoint of facilitating application of the polarizing film-forming composition of the present invention, the polarizing film-forming composition preferably further contains a solvent. The solvent is preferably an organic solvent that can dissolve the components contained in the polarizing film-forming composition of the present invention, and more preferably an organic solvent that is inert to the polymerization reaction. Examples of solvents include alcoholic solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, or propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, or ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, or methyl isobutyl ketone; non-chlorinated aliphatic hydrocarbon solvents such as pentane, hexane, or heptane; non-chlorinated aromatic solvents such as toluene, xylene, or phenol; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran or dimethoxyethane; chlorinated aliphatic hydrocarbon solvents such as chloroform or chlorobenzene; and amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These organic solvents may be used alone or in combination.

[0110] When the composition for forming a polarizing film of the present invention contains a solvent, the solids concentration of the composition for forming a polarizing film of the present invention is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. When the solids concentration is at least the above-mentioned lower limit, the thickness of the obtained polarizing film is not too thin, and the dichroism required for the polarizing film is easily obtained. When the solids concentration is at most the above-mentioned upper limit, the viscosity of the composition for forming a polarizing film is low, and unevenness in the thickness of the coating film of the composition tends to be less likely to occur.

[0111] <Polarizing film forming composition> In one embodiment of the present invention, when the polarizing film-forming composition of the present invention contains a liquid crystal compound in addition to the reactive additive and the dichroic dye, it preferably satisfies the following formula (X): {(A)+(B)} / (C)≧0.7 (X) In formula (X), (A) represents the mass of the dichroic dye having a polymerizable group in the composition for forming a polarizing film, (B) represents the mass of the liquid crystal compound having a polymerizable group in the composition for forming a polarizing film, (C) represents the total mass of the total amount of dichroic dyes and the total amount of liquid crystal compounds in the polarizing film-forming composition. Note that, when the dichroic dyes include a first dichroic dye having a polymerizable group and a second dichroic dye not having a polymerizable group, the total amount of dichroic dyes represents the total amount of the first dichroic dye and the second dichroic dye. Similarly, when the liquid crystal compounds include a first liquid crystal compound having a polymerizable group and a second liquid crystal compound not having a polymerizable group, the total amount of liquid crystal compounds represents the total amount of the first liquid crystal compound and the second liquid crystal compound.

[0112] When the polarizing film-forming composition of the present invention contains a liquid crystal compound having a polymerizable group, and the polarizing film-forming composition satisfies formula (X), i.e., when the ratio {(A) + (B)} / (C) is 0.7 or greater, the polymerizable group of the reactive additive and the polymerizable group of the dichroic dye or liquid crystal compound can readily react with each other, thereby improving the adhesion of the resulting polarizing film to the alignment film. From the viewpoint of further improving the adhesion of the resulting polarizing film, the ratio {(A) + (B)} / (C) is more preferably 0.8 or greater, even more preferably 0.9 or greater, and particularly preferably 0.95 or greater, with the upper limit of this ratio being 1 or less. Alternatively, the ratio may be 1, and the polarizing film-forming composition of the present invention may be free of a dichroic dye without a polymerizable group and a liquid crystal compound without a polymerizable group.

[0113] The viscosity of the composition of the present invention is preferably 0.1 to 10 mPa·s, more preferably 0.1 to 7 mPa·s, and even more preferably 0.1 to 5 mPa·s, from the viewpoint of easily making the thickness of the resulting polarizing film uniform.

[0114] The method for producing the polarizing film-forming composition of the present invention is not particularly limited, and the composition can be produced, for example, by uniformly mixing the components constituting the polarizing film-forming composition using a mixer or stirrer.

[0115] [Polarizing film] The polarizing film of the present invention is a cured product of the polarizing film-forming composition of the present invention, and can be obtained by polymerizing compounds having a polymerizable group contained in the composition, i.e., a reactive additive and a dichroic dye having a polymerizable group, and optionally a liquid crystal compound having a polymerizable group and a non-liquid crystal compound having a polymerizable group. A polarizing film is a substance that decomposes unpolarized incident light into two orthogonal polarized components, transmits one polarized component, and absorbs the other polarized component. The axial direction of the transmitted polarized component is called the transmission axis, and the axial direction of the absorbed polarized component is called the absorption axis.

[0116] The polarizing film of the present invention is a cured product of a polarizing film-forming composition containing a reactive additive having both a polymerizable group and an active hydrogen-reactive group, and a dichroic dye having a polymerizable group. Therefore, when laminated with an alignment film, it exhibits high adhesion to the alignment film. This effect is believed to be achieved because the polymerizable group of the reactive additive and the polymerizable group of the dichroic dye forming the polarizing film form a bond through a polymerization reaction within the polarizing film, and because the active hydrogen-reactive group in the reactive additive can react with the alignment film to form a bond. Furthermore, when the alignment film has a transparent substrate on the opposite side of the polarizing film, the active hydrogen-reactive group in the reactive additive in the polarizing film can also react with the transparent substrate to form a bond, which is believed to be another reason for the effect. Here, the active hydrogen-reactive group in the reactive additive is believed to react with the active hydrogen-reactive group in the alignment film or the transparent substrate to form a bond. The active hydrogen-reactive group in the polarizing film can react with the alignment film outside the polarizing film or with the transparent substrate on the opposite side of the alignment film to form a bond because the polarizing film of the present invention is a coating-type polarizing film. In detail, the polarizing film of the present invention is formed by applying a polarizing film-forming composition containing an unreacted reactive additive and the like to the alignment film, and then curing the polarizing film-forming composition. Therefore, it is believed that the polymerizable group of the reactive additive can react with the polymerizable group in the dichroic dye when the polarizing film-forming composition is cured.

[0117] In the polarizing film of the present invention, the dichroic dye having a polymerizable group and / or its polymer is preferably oriented in the horizontal direction relative to the plane of the polarizing film. Furthermore, when the composition for forming a polarizing film of the present invention contains a liquid crystal compound having a polymerizable group, the polarizing film of the present invention preferably has the liquid crystal compound having a polymerizable group and / or its polymer oriented in a direction horizontal to the plane of the polarizing film. A polarizing film having the above-described alignment property can be obtained by applying a polarizing film-forming composition onto a substrate having an alignment function, as described below, aligning the dichroic dye and the liquid crystal compound in a direction horizontal to the plane of the substrate, and curing the composition in the aligned state.

[0118] The polarizing film of the present invention is preferably an alignment film that exhibits a Bragg peak in X-ray diffraction measurement.

[0119] The thickness of the polarizing film is preferably 0.1 μm to 10 μm, more preferably 0.3 μm to 5 μm, and even more preferably 0.5 μm to 3 μm, from the viewpoint of the alignment of the dichroic dye having a polymerizable group and the liquid crystal compound optionally containing a polymerizable group. If the thickness of the polarizing film is equal to or greater than the lower limit, the dichroic dye and the liquid crystal compound optionally contained are unlikely to be aligned in the vertical alignment direction, and therefore the alignment order is likely to be improved. On the other hand, if the thickness of the polarizing film is equal to or less than the upper limit, the dichroic dye and the liquid crystal compound optionally contained are unlikely to be aligned randomly, and therefore the alignment order is likely to be improved. The thickness of the polarizing film can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

[0120] [Method for producing polarizing film] The polarizing film of the present invention can be formed on a substrate by a method including the steps of applying the polarizing film-forming composition of the present invention onto a substrate having an alignment function, and curing the polarizing film-forming composition applied onto the substrate.

[0121] In one embodiment of the present invention, when the composition for forming a polarizing film of the present invention contains a solvent, the polarizing film of the present invention may be formed on the substrate by applying the composition for forming a polarizing film of the present invention onto a substrate having an alignment function, then removing the solvent contained in the composition, and curing the composition for forming a polarizing film from which the solvent has been removed.

[0122] The substrate having an alignment function is not particularly limited as long as it has an alignment function, and examples thereof include glass substrates and film substrates. Among these, film substrates are preferred, and long rolled films are more preferred from the viewpoint of continuous production. Examples of resins constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid esters; polyacrylic acid esters; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide, and polyphenylene oxide. In one embodiment of the present invention, the substrate having an alignment function may be an alignment film as described below.

[0123] Examples of commercially available cellulose ester substrates include "Fujitac Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (all manufactured by Konica Minolta Opto, Inc.). Commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona GmbH, Germany), "Arton" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (all manufactured by Zeon Corporation), and "Apel" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such cyclic olefin resins can be formed into a film by known means such as solvent casting or melt extrusion, and used as a substrate. Commercially available cyclic olefin resin substrates can also be used. Commercially available cyclic olefin resin substrates include "S-Cina" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Co., Ltd.), "ZEONORFILM" (registered trademark) (manufactured by Optes Co., Ltd.), and "ArtonFILM" (registered trademark) (manufactured by JSR Corporation).

[0124] The thickness of the substrate is preferably thin from the viewpoint of practical handling, but is preferably thick from the viewpoint of strength and processability. In one embodiment of the present invention, the thickness of the substrate is preferably 5 μm to 300 μm, more preferably 20 μm to 200 μm. Furthermore, by peeling the obtained polarizing film from the substrate and transferring a polymer of the dichroic dye having a polymerizable group and the liquid crystal compound optionally having a polymerizable group to the polarizing film, the polarizing film of the present invention alone can be applied to a polarizing plate used in an image display panel or the like, thereby achieving the effect of further reducing the thickness of the polarizing plate used in an image display panel.

[0125] Examples of methods for applying the polarizing film-forming composition of the present invention to a substrate having an alignment function include extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, or die coating; and methods using a coater such as a dip coater, bar coater, or spin coater. Among these, when applying continuously in a roll-to-roll manner, coating methods such as a microgravure method, inkjet coating, slit coating, and die coating are preferred, and when applying to a sheet of substrate such as glass, spin coating, which provides high uniformity, is preferred. When applying in a roll-to-roll manner, the alignment film-forming composition or the like can be applied to a substrate to form an alignment film, and then the polarizing film-forming composition can be continuously applied onto the resulting alignment film.

[0126] Methods for removing the solvent contained in the polarizing film-forming composition coated on a substrate include natural drying, forced air drying, heat drying, and reduced pressure drying. The solvent is preferably removed under conditions that do not polymerize the compound having a polymerizable group contained in the polarizing film-forming composition. The drying temperature is preferably 0 to 250°C, more preferably 20 to 150°C, and even more preferably 50 to 130°C. The drying time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. The photo-alignment film-forming composition and the alignable polymer composition described below can also be dried in the same manner.

[0127] The polarizing film-forming composition applied to the substrate is cured by polymerizing the compounds having polymerizable groups (the reactive additive and dichroic dye, and optionally the liquid crystal compound and non-liquid crystal compound) contained in the polarizing film-forming composition. The polymerization method for the compound having a polymerizable group may be selected depending on the type of polymerizable group. If the polymerizable group is photopolymerizable, the polarizing film-forming composition can be polymerized and cured by photopolymerization. If the polymerizable group is thermally polymerizable, the polarizing film-forming composition can be polymerized and cured by thermal polymerization. The polarizing film of the present invention is preferably polymerized by photopolymerization. Photopolymerization allows polymerization at low temperatures and facilitates industrial production. The light used in photopolymerization is appropriately selected depending on the type and amount of polymerizable groups in the compound having a polymerizable group contained in the polarizing film-forming composition. Specific examples include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays, and actinic electron beams. Among these, ultraviolet light is preferred from the viewpoint of ease of controlling the progress of the polymerization reaction and from the viewpoint of the availability of photopolymerization devices that are widely used in this field.

[0128] Examples of the light source of the active energy rays include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light in a wavelength range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

[0129] The UV irradiation intensity is usually 10 to 3,000 mW / cm 2 The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating a photopolymerization initiator. The light irradiation time is usually 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 irradiating once or multiple times with such ultraviolet irradiation intensity, the cumulative light amount is 10 to 3,000 mJ / cm. 2 , preferably 50 to 2,000 mJ / cm 2, more preferably 100 to 1,000 mJ / cm 2 is.

[0130] [Optical laminate] The present invention also includes an optical laminate having an alignment film on at least one surface of the polarizing film of the present invention. <Alignment film> In the present invention, an alignment film is a film made of a polymer compound and has the ability to align a liquid crystal compound in a desired direction. The alignment film facilitates the alignment of the liquid crystal compound (a dichroic dye having a polymerizable group and / or a liquid crystal compound having a polymerizable group, if present) contained in the polarizing film. The liquid crystal alignment state, such as horizontal alignment, vertical alignment, hybrid alignment, or tilted alignment, varies depending on the properties of the alignment film and the liquid crystal compound, and any combination thereof can be selected. For example, if the alignment film is made of a material that exerts a horizontal alignment as an alignment force, the liquid crystal compound can form horizontal or hybrid alignment, while if the alignment film is made of a material that exerts a vertical alignment, the liquid crystal compound can form vertical or tilted alignment. The terms horizontal, vertical, and the like refer to the direction of the long axis of the aligned liquid crystal compound relative to the plane of the polarizing film. Horizontal alignment refers to an alignment in which the long axis of the aligned liquid crystal compound is parallel to the plane of the polarizing film. Here, "parallel" refers to an angle of 0°±20° relative to the plane of the polarizing film. Vertical alignment means that the long axis of the liquid crystal compound is aligned perpendicular to the plane of the polarizing film. Here, "perpendicular" means 90°±20° relative to the plane of the polarizing film.

[0131] When the alignment film is made of an alignment polymer, the alignment restraining force can be adjusted arbitrarily by changing the surface condition or rubbing conditions, and when it is made of a photoalignment polymer, the alignment restraining force can be adjusted arbitrarily by changing the polarized light irradiation conditions, etc. Furthermore, the liquid crystal alignment can also be controlled by selecting the physical properties, such as the surface tension or liquid crystallinity, of the compound exhibiting liquid crystallinity.

[0132] The alignment film formed on at least one surface of the polarizing film is preferably insoluble in a solvent used when forming the polarizing film on the alignment film, and is heat resistant to the heat treatment for removing the solvent and for aligning the liquid crystal.

[0133] In one embodiment of the present invention, the alignment film is preferably an alignment film having an active hydrogen group. When the alignment film has an active hydrogen group, the active hydrogen group of the alignment film reacts with the active hydrogen reactive group of the reactive additive contained in the polarizing film to form a bond, and the alignment film and the polarizing film are bonded via the reactive additive, which makes it easy to increase the adhesion between the polarizing film and the alignment film, and makes it easy to obtain an optical laminate that is less likely to peel between the polarizing film and the alignment film.

[0134] Examples of active hydrogen groups include groups having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), and an amino group (-NH). These active hydrogen groups may be used alone or in combination of two or more. The active hydrogen groups of the alignment film are preferably selected depending on the active hydrogen-reactive groups of the reactive additive contained in the polarizing film. For example, if the reactive additive in the polarizing film has an isocyanate group as the active hydrogen-reactive group, the alignment film preferably has a hydroxyl group and / or an amino group. If the reactive additive in the polarizing film has an alkoxysilyl group as the active hydrogen-reactive group, the alignment film preferably has a hydroxyl group. In one embodiment of the present invention, the alignment film preferably has a hydroxyl group. In one embodiment of the present invention, the optical laminate preferably has an alignment film having a hydroxyl group formed on at least one surface of a polarizing film containing a reactive additive having an isocyanate group or an alkoxysilyl group, and more preferably has an alignment film having a hydroxyl group formed on at least one surface of a polarizing film containing a reactive additive having an isocyanate group.

[0135] In one embodiment of the present invention, the thickness of the alignment film is preferably 0.01 μm or more from the viewpoint of easily exerting a sufficient alignment control force, and is preferably 0.5 μm or less, more preferably 0.3 μm or less, and even more preferably 0.2 μm or less from the viewpoint of easily making the optical laminate thin.

[0136] In another embodiment of the present invention, the alignment film may be an alignment film that does not have an active hydrogen group. In this case, the alignment film preferably has a transparent substrate having an active hydrogen group on the side opposite the polarizing film. When the alignment film has a transparent substrate having an active hydrogen group on the side opposite the polarizing film, even if the alignment film does not have an active hydrogen group, the active hydrogen reactive group of the reactive additive in the polarizing film can react with the active hydrogen group in the transparent substrate to form a bond. Therefore, the polarizing film and the transparent substrate are bonded via the reactive additive with the alignment film sandwiched between them, which makes it easy to increase the adhesion between the polarizing film and the alignment film, and makes it easy to obtain an optical laminate that is less likely to peel between the polarizing film and the alignment film.

[0137] The transparent substrate having an active hydrogen group is not particularly limited as long as it has an active hydrogen group, and examples thereof include transparent films such as cellulose ester films such as triacetyl cellulose (TAC) films, cycloolefin polymer (COP) films whose surfaces have been modified by corona discharge irradiation, polymethyl methacrylate (PMMA) films whose surfaces have been modified by corona discharge irradiation, and polyethylene terephthalate (PET) films whose surfaces have been modified by corona discharge irradiation.

[0138] In one embodiment of the present invention in which the alignment film has a transparent substrate having active hydrogen groups on the surface opposite to the polarizing film, the thickness of the alignment film is preferably 0.01 μm or more and 0.2 μm or less, more preferably 0.15 μm or less, from the viewpoint of easily improving adhesion between the polarizing film and the alignment film. When the alignment film is as thin as 0.2 μm or less, even if the alignment film does not have active hydrogen groups and it is difficult for the polarizing film and the alignment film to form a bond directly via the reactive additive, the reactive additive in the polarizing film easily forms a bond with the active hydrogen groups in the transparent substrate, and as a result, it is easy to improve adhesion between the polarizing film and the alignment film.

[0139] In one embodiment of the present invention, the alignment film having no active hydrogen group preferably has a poly(meth)acryloyl structure or a polysilazane structure.

[0140] In one embodiment of the present invention, even when the alignment film has an active hydrogen group, the alignment film may have a transparent substrate, more preferably a transparent substrate having an active hydrogen group, on the side opposite to the polarizing film, from the viewpoint of making it easier to enhance the adhesion between the alignment film and the polarizing film.

[0141] In one embodiment of the present invention, examples of the alignment film include an alignment film made of an orientable polymer, a photo-alignment film, a groove alignment film, and a stretched film stretched in the alignment direction. When applied to a long rolled film, a photo-alignment film is preferred because the alignment direction can be easily controlled.

[0142] The alignment film can be obtained by applying an alignment polymer composition containing an alignment polymer and a solvent, or a composition for forming a photo-alignment film containing a polymer or monomer having a photoreactive group and a solvent, onto a substrate, removing the solvent contained in the alignment polymer composition or the composition for forming a photo-alignment film, and then subjecting the alignment polymer composition or the composition for forming a photo-alignment film from which the solvent has been removed to a rubbing treatment or a polarized light irradiation treatment.

[0143] The substrate to which the alignment polymer composition and the photoalignment film-forming composition are applied is not particularly limited, and examples thereof include glass, plastic sheets, plastic films, and light-transmitting films. Examples of light-transmitting films include polyolefin films such as polyethylene, polypropylene, and norbornene-based polymers, polyethylene terephthalate films, polymethacrylate films, polyacrylate films, cellulose ester films such as triacetyl cellulose films, polyethylene naphthalate films, polycarbonate films, polysulfone films, polyethersulfone films, polyetherketone films, polyphenylene sulfide films, and polyphenylene oxide films. The substrate may be a film that has been subjected to corona discharge irradiation and surface modification. The substrate is preferably a transparent substrate, and more preferably a transparent substrate having an active hydrogen group, such as a cellulose ester film such as a triacetyl cellulose film, a cycloolefin polymer film whose surface has been modified by corona discharge irradiation, a polymethyl methacrylate (PMMA) film whose surface has been modified by corona discharge irradiation, or a polyethylene terephthalate (PET) film whose surface has been modified by corona discharge irradiation, from the viewpoint of making it easier to enhance the adhesion between the alignment film and the polarizing film.

[0144] Examples of the oriented polymer contained in the oriented polymer composition include polyamide and gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, and polyamic acid, which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid ester. Among these, polyvinyl alcohol is preferred from the viewpoint of easily improving the adhesion between the polarizing film and the oriented film. These oriented polymers may be used alone or in combination of two or more.

[0145] Examples of solvents contained in the orientable polymer composition include water; alcohol solvents such as 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, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene. These solvents may be used alone or in combination of two or more.

[0146] The concentration of the orienting polymer in the orienting polymer composition may be within a range in which the orienting polymer can be completely dissolved in the solvent, and is preferably 0.1 to 20 mass %, more preferably 0.1 to 10 mass %, calculated as solid content relative to the solution.

[0147] The oriented polymer composition may be a commercially available alignment film material, such as Sunever (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.) or Optomer (registered trademark) (manufactured by JSR Corporation).

[0148] The method for applying the oriented polymer composition to a substrate and the method for removing the solvent contained in the oriented polymer composition can be the same as the method for applying a composition for forming a polarizing film to a substrate and the method for removing the solvent, respectively, in the production of a polarizing film.

[0149] Rubbing methods include a method in which an oriented polymer composition is applied to the diffusion prevention layer and annealed to bring the oriented polymer film formed on the surface of the diffusion prevention layer into contact with a rotating rubbing roll wrapped with a rubbing cloth.

[0150] A photo-alignment film can be obtained by applying a composition (photo-alignment film-forming composition) containing a polymer, oligomer, or monomer having a photoreactive group and a solvent to a substrate, drying to remove the solvent, and then irradiating the substrate with polarized light, preferably polarized UV. Photo-alignment films are preferred because the direction of the alignment control force can be freely controlled by selecting the polarization direction of the polarized light to be irradiated. The polymer or monomer having a photoreactive group contained in the composition for forming a photoalignment film is not particularly limited as long as it has a photoreactive group. However, from the viewpoint of solvent resistance, etc., a polymer with a weight-average molecular weight of 5000 or more is preferred. A photoreactive group is a group that exhibits liquid crystal alignment ability upon irradiation with light. Specifically, it is a group that induces a photoreaction that is the origin of liquid crystal alignment ability, such as molecular alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, upon irradiation with light. Among such photoreactive groups, those that undergo dimerization reaction or photocrosslinking reaction are preferred in terms of excellent alignment ability. As photoreactive groups capable of undergoing such reactions, those having an unsaturated bond, particularly a double bond, are preferred, and groups having at least one bond 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) are more preferred.

[0151] 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, bisazo groups, and formazan groups, as well as groups with an azoxybenzene basic 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 halogenated alkyl groups.

[0152] The solvent contained in the composition for forming a photo-alignment film is preferably one that dissolves the polymer and monomer having a photoreactive group, and examples of such a solvent include the solvents exemplified as the solvent for the alignment polymer composition.

[0153] The concentration of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be adjusted appropriately depending on the type of polymer or monomer having a photoreactive group and the thickness of the photoalignment film to be produced, but is preferably 0.2 mass% or more, and particularly preferably in the range of 0.3 to 10 mass%. Furthermore, the composition for forming a photoalignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer, within a range that does not significantly impair the properties of the photoalignment film.

[0154] The method for applying the composition for forming a photo-alignment film to a substrate may be the same as the method for applying the alignment polymer composition to a substrate. The method for removing the solvent from the applied composition for forming a photo-alignment film may be the same as the method for removing the solvent from the alignment polymer composition.

[0155] The polarized light irradiation method may involve directly irradiating the substrate with polarized light after removing the solvent from the composition for forming a photo-alignment film coated thereon, or irradiating the substrate with polarized light and then transmitting the polarized light. It is particularly preferred that the polarized light be substantially parallel. The wavelength of the polarized light to be irradiated should be within a wavelength range in which the photoreactive group in the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength of 250 to 400 nm is particularly preferred. Examples of light sources used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. High-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferred. These lamps are preferred because of their high emission intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by passing the light from the light source through an appropriate polarizer. Examples of such polarizers include polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire-grid polarizers.

[0156] If masking is performed during rubbing or polarized light irradiation, a plurality of regions (patterns) with different liquid crystal alignment directions can be formed.

[0157] <Transparent thin film> The optical laminate of the present invention may further include a transparent thin film. In one embodiment of the present invention, the optical laminate preferably includes an alignment film on one side of the polarizing film and a transparent thin film on the other side. The transparent thin film is not particularly limited and may be, for example, a resin film. Examples of the resin constituting the resin film include water-soluble polymers and photocurable resins. Examples of water-soluble polymers include polyacrylamide-based polymers; polyvinyl alcohol; and vinyl alcohol-based polymers such as ethylene-vinyl alcohol copolymers and (meth)acrylic acid or its anhydride-vinyl alcohol copolymers; carboxyvinyl-based polymers; polyvinylpyrrolidone; starches; sodium alginate; or polyethylene oxide-based polymers. Examples of photocurable resins include acrylic resins, urethane-based resins, acrylic urethane-based resins, epoxy-based resins, and silicone-based resins.

[0158] The thickness of the transparent thin film is preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm, and even more preferably 0.5 to 3 μm.

[0159] [Method for producing optical laminate] The optical laminate of the present invention can be produced by a method including a step of forming an alignment film on a substrate, preferably on the above-mentioned transparent substrate, more preferably on a transparent substrate having an active hydrogen group, and a step of forming a polarizing film on the alignment film, and in some cases, can be produced by a method further including a step of forming a transparent thin film on the polarizing film formed on the alignment film.

[0160] [Circular polarizer] The present invention also encompasses a circular polarizing plate comprising the optical laminate of the present invention and a retardation film. A circular polarizing plate is a functional layer having the function of transmitting only right- or left-handed circularly polarized light components by laminating a λ / 4 retardation plate on a linear polarizing plate. The circular polarizing plate of the present invention may comprise a retardation film on either side of the optical laminate of the present invention. In the present invention, it is preferable to achieve complete circular polarization across all wavelengths, but this is not necessarily required in practice, and therefore the circular polarizing plate of the present invention also encompasses an elliptically polarizing plate.

[0161] In one embodiment of the present invention, the retardation film is preferably a retardation film whose birefringence Δn(λ) with respect to light having a wavelength of λ nm exhibits retardation properties represented by the following formulas (1-1), (2-1), and (3): Δn(450) / Δn(550)≦1.00 (1-1) 1.00≦Δn(650) / Δn(550) (2-1) 120≦Re(550)≦180 (3)

[0162] In the formula, Δn(450), Δn(550), and Δn(650) represent birefringence at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

[0163] The birefringence Δn(λ) is obtained by measuring the in-plane retardation and dividing it by the thickness of the retardation film. That is, the retardation film is preferably a retardation film exhibiting retardation properties represented by the following formulas (1) and (2) and the above formula (3). Re(450) / Re(550)≦1.00 (1) 1.00≦Re(650) / Re(550) (2)

[0164] Re(450), Re(550), and Re(650) represent the in-plane retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

[0165] The thickness of the retardation film is not particularly limited and may be, for example, 100 μm or less, and from the viewpoint of thinning the display, it is preferably 0.5 μm to 20 μm, more preferably 1 μm to 3 μm. Examples of such a very thin retardation film having a thickness of 1 μm to 3 μm include a polymer film obtained by curing polymerizable liquid crystal in an aligned state.

[0166] The circularly polarizing plate of the present invention can be used in various display panels (or display devices). A display panel is a device or panel having a display element, and includes a light-emitting element or a light-emitting device as a light source. Examples of display panels include liquid crystal display panels, organic electroluminescence (EL) display panels, inorganic electroluminescence (EL) display panels, touch panel display panels, electron emission display panels (e.g., field emission display panels (FEDs) and surface field emission display panels (SEDs)), electronic paper (display panels using electronic ink or electrophoretic elements), plasma display panels, projection display panels (e.g., grating light valve (GLV) display panels and display panels having digital micromirror devices (DMDs)) and piezoelectric ceramic displays. Liquid crystal display panels include transmissive liquid crystal display panels, semi-transmissive liquid crystal display panels, reflective liquid crystal display panels, direct-view liquid crystal display panels and projection liquid crystal display panels. These display panels may be display panels that display two-dimensional images or stereoscopic display panels that display three-dimensional images. In particular, the circularly polarizing plate of the present invention can be effectively used for liquid crystal display panels and organic electroluminescence (EL) display panels.

[0167] In one embodiment of the present invention, the display panel is preferably a flexible panel, and the present invention also encompasses a flexible panel comprising the circular polarizer of the present invention.

[0168] By transferring the circularly polarizing plate of the present invention to the above-mentioned various display panels, preferably flexible panels, and using the same, it is possible to impart a uniform circularly polarizing plate to the above-mentioned various display panels without being significantly affected by the state of the area to be transferred, such as the state of steps or uneven structures. [Example]

[0169] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" in the examples mean % by mass and parts by mass, respectively. First, the dichroic dyes and polymerizable liquid crystal compounds used in the examples and comparative examples will be shown.

[0170] <Dichroic dye> Dichroic dye (2-1): [ka] Dichroic dye (2-2): [ka] Dichroic dye (A-4): [ka] Dichroic dye (B-5): [ka]

[0171] The dichroic dyes (2-1) and (2-2) were synthesized according to the method described in JP-A-2019-172987. As the dichroic dyes (A-4) and (B-5), the dichroic dyes described in JP-A-2013-101328 were used.

[0172] <Liquid crystal compounds> Polymerizable liquid crystal compound (1-6): [ka] Polymerizable liquid crystal compound (1-8): [ka]

[0173] The polymerizable liquid crystal compound (1-6) and the polymerizable liquid crystal compound (1-8) were synthesized according to the method described in JP-A-2019-172987.

[0174] <Evaluation of Adhesion> The adhesion between the polarizing film and the alignment film in the optical laminates obtained in the Examples and Comparative Examples was evaluated by the following method.

[0175] (peel test) A 25 mm wide piece of Scotch tape (registered trademark, manufactured by Nichiban) was applied to each of the front and back surfaces of the obtained optical laminate, with a length of 30 mm, and a 90° peel test was performed on both the front and back surfaces. A sample in which no peeling occurred between the alignment film and the polarizing film, a B sample in which partial peeling occurred between the alignment film and the polarizing film, and a C sample in which complete peeling occurred between the alignment film and the polarizing film were evaluated. The test results are shown in Table 1.

[0176] (Cross-hatch test) The adhesion between the alignment film and the polarizing film in the obtained optical laminate was evaluated by a crosshatch test (JIS "checkerboard adhesion test") in accordance with JIS D0202-1988. A 10x10 grid was created at 2mm intervals on the transparent thin film surface of the optical laminate, penetrating all the way to the alignment film, to create a grid. An adhesive tape (25mm wide, manufactured by Nichiban) was completely attached to the grid surface. The adhesive tape was then peeled off at a 90° angle relative to the surface. The number of squares remaining without peeling was rated as A for ≥ 90 / 100, B for ≥ 80 / 100, and C for ≤ 79 / 100. Regarding the peeled squares, X-ray photoelectron spectroscopy (XPS) was used to confirm that the peeled interface was between the alignment film and the polarizing film. The test results are shown in Table 1.

[0177] Example 1 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 1 for forming a polarizing film. Dichroic dye (2-1): 4.0 parts Reactive additive: LALOMER LR9000 (manufactured by BASF Japan): 2.0 parts [ka] Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Polymerization initiator: 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals): 6 parts Leveling agent: polyacrylate compound (BYK-361N; manufactured by BYK-Chemie): 1.2 parts Solvent: xylene: 450 parts

[0178] (Production of optical laminate) 1. Formation of alignment layer A 2% by mass aqueous solution of polyvinyl alcohol (Polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied by bar coating onto a triacetyl cellulose (TAC) film (KC8UX2M, manufactured by Konica Minolta, Inc.) cut to a size of 80 x 80 mm, and the coating was dried to form a dried coating film with a thickness of 0.1 μm. Subsequently, the surface of the obtained dried coating film was subjected to a rubbing treatment to form an alignment film with alignment control power. The rubbing treatment was carried out using a semi-automatic rubbing device (product name: LQ-008, manufactured by Joyo Engineering Co., Ltd.) with a cloth (product name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) under the conditions of a pressing depth of 0.15 mm, a rotation speed of 500 rpm, and a speed of 16.7 mm / s.

[0179] 2. Formation of polarizing film The polarizing film-forming composition 1 was applied onto the alignment film by bar coating, and the coating was dried by heating in an oven at 120°C for 1 minute, and then quickly cooled to room temperature to form a dried coating film of the polarizing film-forming composition 1 on the alignment film. In the dried coating film, the liquid crystal state of the dichroic dye and liquid crystal compound contained therein was a smectic B phase. Next, ultraviolet light was irradiated using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) at an exposure dose of 2400 mJ / cm. 2The dried coating film was irradiated with light of 365 nm (reference wavelength), whereby the dichroic dye and the liquid crystal compound contained in the dried coating film were polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing film was formed from the dried coating film. The thickness of the polarizing film was measured using a laser microscope (OLS3000, manufactured by Olympus Corporation) and found to be 2.3 μm.

[0180] 3. X-ray Diffraction Measurement X-ray diffraction measurements were performed on the resulting polarized film using an X'Pert PRO MPD X-ray diffractometer (Spectris, Inc.). Using a Cu target, X-rays were generated at an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV. The X-rays were incident from the rubbing direction (the rubbing direction of the alignment film underneath the polarized film was determined in advance) through a fixed divergence slit of 1 / 2°. Scanning was performed over the 2θ range of 4.0 to 40.0° in 2θ = 0.01671° steps. A sharp diffraction peak with a peak full width at half maximum (FWHM) of approximately 0.312° was observed near 2θ = 20.08°. Similar results were obtained with the incident light perpendicular to the rubbing direction. The order period (d) determined from the peak position was approximately 4.42 Å, indicating the formation of a highly smectic phase.

[0181] 4. Fabrication of Optical Laminates The surface of the resulting polarizing film was then subjected to a corona treatment, and an aqueous solution (viscosity: 92 cP) containing 7 parts of a carboxyl group-modified polyvinyl alcohol (Kuraray Poval KL318, manufactured by Kuraray Co., Ltd.) and 3.5 parts of a water-soluble polyamide epoxy resin (Sumirez Resin 650, obtained from Sumika Chemtex Co., Ltd., an aqueous solution with a solids concentration of 30% by mass) as a thermal crosslinker was then applied to the corona-treated surface by a spin coater, and dried at 80°C for 5 minutes to form a transparent thin film with a thickness of 1 μm on the polarizing film.

[0182] <Example 2> (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 2 for forming a polarizing film. Dichroic dye (2-2): 4.0 parts Reactive additive; LALOMER LR9000: 2.0 parts Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: xylene: 450 parts

[0183] (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 2 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0184] Example 3 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 3 for forming a polarizing film. Dichroic dye (2-2): 4.0 parts Reactive additive: LALOMER LR9000 (manufactured by BASF): 1.0 part Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Non-liquid crystal compound: dipentaerythritol hexaacrylate (DPHA): 1.0 part Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: xylene: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 3 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0185] <Examples 4 and 5> Compositions 4 and 5 for forming a polarizing film were prepared in the same manner as in Example 2, except that the amount of the reactive additive was changed as shown in Table 1. Optical laminates were prepared and evaluated in the same manner as in Example 1, except that compositions 4 and 5 were used instead of composition 1 for forming a polarizing film.

[0186] Example 6 In the same manner as in Example 2, a composition 2 for forming a polarizing film was prepared. An optical laminate was produced and evaluated in the same manner as in Example 1, except that the alignment film was formed as follows.

[0187] Formation of alignment film (Preparation of composition for forming alignment film) The following components were mixed, and the mixture was stirred at 80° C. for 1 hour to obtain a composition for forming an alignment film. Photo-alignable polymer: Part 2 o-xylene: 98 parts The photoalignment polymer is a polymer having the following formula described in JP-A-2013-033249: [ka] The polymer (number average molecular weight: about 28,000) represented by the following formula was used.

[0188] (Formation of alignment film) A TAC film (KC8UX2M, manufactured by Konica Minolta, Inc.) cut to a size of 80 x 80 mm was used as the substrate. After subjecting the surface of the substrate to a corona treatment, the composition for forming an alignment film was applied to the substrate and dried at 120°C to obtain a dried coating film. Polarized UV was irradiated onto this dried coating film to form an alignment film with a thickness of 0.2 µm. The polarized UV treatment was carried out using a UV irradiation device (SPOT CURE SP-7, manufactured by Ushio Inc.) with an intensity of 100 mJ / cm2 measured at a wavelength of 365 nm. 2 The experiment was carried out under the following conditions.

[0189] Example 7 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain composition 7 for forming a polarizing film. Dichroic dye (2-2): 4.0 parts Reactive additive: Karenz AOI (2-isocyanatoethyl acrylate, manufactured by Showa Kako Co., Ltd.): 2.0 parts Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: xylene: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 7 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0190] Example 8 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain composition 8 for forming a polarizing film. Dichroic dye (2-2): 40 parts Reactive additive: LALOMER LR9000 (manufactured by BASF Japan): 2.0 parts Polymerizable liquid crystal compound (1-6): 45 parts Polymerizable liquid crystal compound (1-8): 15 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: chloroform: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 8 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0191] Example 9 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain composition 9 for forming a polarizing film. Dichroic dye (2-2): 13 parts Dichroic dye (A-4): 27 parts Reactive additive: LALOMER LR9000 (manufactured by BASF Japan): 2.0 parts Polymerizable liquid crystal compound (1-6): 45 parts Polymerizable liquid crystal compound (1-8): 15 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: chloroform: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 9 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0192] Example 10 A composition for forming a polarizing film 10 was prepared in the same manner as in Example 2, except that the amount of the reactive additive was changed as shown in Table 1. Each optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 10 for forming a polarizing film was used instead of composition 1 for forming a polarizing film. Example 11 (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 11 for forming a polarizing film. Dichroic dye (2-2): 4.0 parts Reactive additive: KBM-5103 (3-acryloyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.): 2.0 parts Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: xylene: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 11 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0193] <Comparative Example 1> (Preparation of composition for forming polarizing film) The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 12 for forming a polarizing film. Dichroic dye (2-1): 4.0 parts Polymerizable liquid crystal compound (1-6): 75 parts Polymerizable liquid crystal compound (1-8): 25 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: xylene: 450 parts

[0194] (Production of optical laminate) 1. Formation of alignment layer A 50 × 50 mm glass substrate was used as the base material, and a 2% by mass aqueous solution of polyvinyl alcohol (Polyvinyl alcohol 1000 fully saponified, manufactured by Wako Pure Chemical Industries, Ltd.) was applied to the glass substrate by spin coating, and the coating was dried to form a film with a thickness of 100 nm. Subsequently, the surface of the obtained film was subjected to a rubbing treatment to form an alignment layer. The rubbing treatment was carried out using a semi-automatic rubbing device (product name: LQ-008, manufactured by Joyo Engineering Co., Ltd.) with a cloth (product name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) under the conditions of a pressing depth of 0.15 mm, a rotation speed of 500 rpm, and a speed of 16.7 mm / s.

[0195] 2. Formation of polarizing film The polarizing film-forming composition 12 was applied onto the alignment film by spin coating, and the coating was dried by heating on a hot plate at 120°C for 3 minutes, and then quickly cooled to room temperature to form a dried coating film of the polarizing film-forming composition 11 on the alignment film. In the dried coating film, the liquid crystal state of the polymerizable liquid crystal compound contained therein was a smectic B phase. Next, ultraviolet light was irradiated using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) at an exposure dose of 2400 mJ / cm. 2The dried coating film was irradiated with light of 365 nm (reference wavelength), whereby the polymerizable liquid crystal compound contained in the dried coating film was polymerized while maintaining the liquid crystal state of the polymerizable liquid crystal composition, and a polarizing film was formed from the dried coating film. The thickness of the polarizing film was measured using a laser microscope (OLS3000, manufactured by Olympus Corporation) and found to be 1.7 μm.

[0196] In "3. X-ray diffraction measurement" and "4. Preparation of optical laminate," an optical laminate was prepared in the same manner as in Example 1 and evaluated.

[0197] <Comparative Example 2> A polarizing film-forming composition 13 was prepared in the same manner as in Comparative Example 1, except that the dichroic dye was changed to (2-2), and an optical laminate was produced and evaluated in the same manner as in Example 1.

[0198] <Comparative Example 3> An optical laminate was produced and evaluated in the same manner as in Comparative Example 2, except that a triacetyl cellulose (TAC) film (KC8UX2M, manufactured by Konica Minolta, Inc.) was used as the substrate.

[0199] <Comparative Example 4> The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition 14 for forming a polarizing film. Dichroic dye (A-4): 27 parts Dichroic dye (B-5): 13 parts Reactive additive: LALOMER LR9000 (manufactured by BASF Japan): 2.0 parts Polymerizable liquid crystal compound (1-6): 45 parts Polymerizable liquid crystal compound (1-8): 15 parts Polymerization initiator: Irgacure 369: 6 parts Leveling agent: BYK-361N: 1.2 parts Solvent: chloroform: 450 parts (Production of optical laminate) An optical laminate was produced and evaluated in the same manner as in Example 1, except that composition 14 for forming a polarizing film was used instead of composition 1 for forming a polarizing film.

[0200] [Table 1]

[0201] As shown in Table 1, it was confirmed that the optical laminates obtained in Examples 1 to 11 had high adhesion between the polarizing film and the alignment film. In contrast, the optical laminates obtained in Comparative Examples 1 to 4 had insufficient adhesion between the polarizing film and the alignment film.

Claims

1. the liquid crystal compound includes a reactive additive having both a polymerizable group and an active hydrogen-reactive group, a dichroic dye having a polymerizable group, and a liquid crystal compound having a polymerizable group, provided that the liquid crystal compound having a polymerizable group does not include the dichroic dye having a polymerizable group; the reactive additive has 2 to 10 active hydrogen reactive groups; the polymerizable group of the reactive additive is a (meth)acryloyl group, and the active hydrogen-reactive group of the reactive additive is an isocyanate group; The dichroic dye having a polymerizable group is represented by the following formula (2): 【Chemistry 1】 [In formula (2), m represents an integer of 0 to 3; A 1 , A 2 and A 3 each independently represent a divalent aromatic group which may have a substituent; L 1 and L 2 each independently represent a single bond, —CH 2 —, —CH 2 CH 2 —, —O—, —CH 2 O—, —OCH 2 —, —CO—, —COO—, —OCO—, —OCOO—, —CR c ═CR d —, —C≡C—, —CR c ═N—, —CONR c —, —NR c CO—, or —N═N—, where R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Z 1 represents a (meth)acryloyloxy group, Z 2 represents a hydrogen atom or a (meth)acryloyloxy group; Q 1 and Q 2 each independently represent a linear or branched alkylene group having 1 to 20 carbon atoms which may have a substituent, an alkenylene group having 1 to 20 carbon atoms which may have a substituent, or an alkynylene group having 1 to 20 carbon atoms which may have a substituent, and —CH 2 — contained in these alkylene groups, alkenylene groups, or alkynylene groups may be substituted with —O—, —S—, or NR e —, where R e represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; T 1 represents a single bond, —O—, —S—, —CO—, —COO—, —OCO—, —OCOO—, —CONR f —, or —NR f CO—; T 2 represents a single bond, —O—, —S—, —CO—, —COO—, —OCO—, —OCOO—, —CONR f —, —NR f CO—, or —NR g —; R f and R g each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; the alkyl group represented by R g may form a ring with Q 1 or Q 2 ; and A 1 -(L 1 -A 2 ) m -L 2 -A 3 represents at least one of —A X1 -N═N-A X2 — (wherein A X1 and A X2 and each represent a divalent aromatic group, and when T 2 is —NR g —, Z 2 represents a hydrogen atom. is a liquid crystal compound represented by the liquid crystal compound having a polymerizable group is a thermotropic liquid crystal compound exhibiting high-order smectic liquid crystallinity, The polarizing film-forming composition, wherein the content of the reactive additive is 5 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the dichroic dye having a polymerizable group.

2. The following formula: {(A)+(B)} / (C)≧0.7 (A): Mass of dichroic dye having a polymerizable group (B): Mass of liquid crystal compound having a polymerizable group (C): Total mass of dichroic dye and liquid crystal compound The composition for forming a polarizing film according to claim 1 , which satisfies the above formula:

3. The composition for forming a polarizing film according to claim 1 or 2, further comprising a non-liquid crystal compound having a polymerizable group.

4. 4. The composition for forming a polarizing film according to claim 3, wherein the non-liquid crystal compound has 3 to 6 polymerizable groups.

5. 5. The composition for forming a polarizing film according to claim 3, wherein the polymerizable group in the non-liquid crystal compound is a (meth)acryloyl group.

6. A polarizing film which is a cured product of the composition for forming a polarizing film according to any one of claims 1 to 5.

7. A polarizing film formed from a cured product of the composition for forming a polarizing film according to any one of claims 1 to 5, wherein a dichroic dye having a polymerizable group and / or a polymer thereof is oriented in a direction horizontal to a plane of the polarizing film.

8. A polarizing film formed from a cured product of the composition for forming a polarizing film according to claim 1, wherein a liquid crystal compound having a polymerizable group and / or a polymer thereof is oriented in a direction horizontal to the plane of the polarizing film.

9. 9. The polarizing film according to claim 6, which exhibits a Bragg peak in X-ray diffraction measurement.

10. The polarizing film according to any one of claims 6 to 9, which has a thickness of 0.1 to 10 µm.

11. An optical laminate comprising an alignment film on at least one surface of the polarizing film according to any one of claims 6 to 10.

12. An optical laminate comprising an alignment film on one side of the polarizing film according to any one of claims 6 to 10 and a transparent thin film on the other side.

13. The optical laminate according to claim 11 or 12, wherein the alignment film has a hydroxyl group.

14. 13. The optical laminate according to claim 11, wherein the alignment film has a poly(meth)acryloyl structure or a polysilazane structure.

15. The optical laminate according to claim 14 , wherein the alignment film further comprises a transparent substrate having an active hydrogen group on the surface opposite to the polarizing film.

16. 16. The optical laminate according to claim 14, wherein the alignment film has a thickness of 0.01 μm or more and 0.2 μm or less.

17. A circularly polarizing plate comprising the optical laminate according to any one of claims 11 to 16 and a retardation film.

18. A flexible panel comprising the circular polarizer according to claim 17.

19. (1) a step of applying the composition for forming a polarizing film according to any one of claims 1 to 5 onto a substrate having an alignment function; and (2) A step of curing the polarizing film-forming composition applied to the substrate; A method for producing a polarizing film, comprising:

20. (a) forming an alignment film on a substrate; and (b) forming the polarizing film according to any one of claims 6 to 10 on the alignment film; A method for producing an optical laminate, comprising:

21. The method for producing an optical laminate according to claim 20 , further comprising the step (c) of forming a transparent thin film on the polarizing film.

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