Composition for forming polarizing film and polarizing film

Abstract

The present invention provides 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 pigment having a polymerizable group.

Description

Technical Field

[0001] The present invention relates to a composition for forming a polarizing film, a polarizing film, an optical stack having the polarizing film, and a method for manufacturing the polarizing film and the optical stack. Prior Technology

[0002] A polarizing plate is used in various image display panels, such as liquid crystal display panels and organic electroluminescent (organic EL) display panels, to be bonded onto image display elements such as liquid crystal cells and organic EL display elements. One known polarizing plate is formed by bonding a protective layer, such as a triacetyl cellulose film, to at least one side of a polarizing film in which dichroic compounds such as iodine or dichroic dyes are adsorbed and aligned in a polyvinyl alcohol-based resin film.

[0003] In recent years, with the increasing demand for thinner image display panels, the polarizing plates constituting these panels have also required to be thinner. As one type of thin polarizing plate, coated polarizing plates have been proposed. For example, Patent Document 1 discloses a polarizing plate having a polarizing film containing a polymer of polymeric liquid crystal and a dichroic pigment. Furthermore, Patent Document 2 discloses a composition capable of forming a polarizing film, containing a polymeric liquid crystal compound of a display layer phase and a dichroic liquid crystal compound. [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-83843 [Patent Document 2] Japanese Patent Application Publication No. 2019-172987 Summary of the Invention

[0005] Polarizing plates used in image display panels and the like are often used in the form of optical stacks having an alignment film on at least one side of the polarizing film. However, according to the research of the inventors, it is known that delamination can occur between the polarizing film and the alignment film in such optical stacks.

[0006] Therefore, the object of the present invention is to provide a polarizing film forming composition that can form a polarizing film with high adhesion to the alignment film and is not easily peeled off from the alignment film. [Technical means to solve the problem]

[0007] The inventors conducted in-depth research to solve the above-mentioned problems, and as a result, completed this invention. Specifically, this invention provides the following preferred form. [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 pigment having a polymerizable group. [2] The polarizing film forming composition of [1] further contains a liquid crystal compound having a polymerizable group. [3] The composition for forming a polarizing film as described in [2] satisfies the following formula: {(A)+(B)} / (C)≧0.7 (A): The mass of dichroic pigments containing polymeric groups (B): Mass of liquid crystal compounds containing polymeric groups (C): Total mass of dichroic pigments and liquid crystal compounds. [4] A polarizing film forming composition of 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 as in [4], wherein the non-liquid crystal compound has 3 to 6 polymerizable groups. [6] A composition for forming a polarizing film as described in any of [1] to [5], wherein the polymerizable group in the dichroic pigment is (meth)acrylic. [7] A composition for forming a polarizing film as described in any of [1] to [6], wherein the polymerizable group in the reactive additive is (meth)acrylic. [8] A composition for forming a polarizing film, such as [4] or [5], wherein the polymerizable group in the non-liquid crystal compound is (meth)acrylyl. [9] A composition for forming a polarizing film as described in any one of [1] to [8], wherein the content of the reactive additive is more than 2 parts by mass and less than 200 parts by mass relative to 100 parts by mass of the dichroic pigment having a polymerizable group.

[10] A polarizing film, which is a cured form of a polarizing film forming composition of any one of [1] to [9].

[11] A polarizing film formed from a hardened composition of a polarizing film forming composition of any one of [1] to [9], wherein a dichroic pigment having a polymeric group and / or its polymer is aligned in a horizontal direction relative to the plane of the polarizing film.

[12] A polarizing film formed from a hardened copy of a polarizing film forming composition of any one of [2] to [9], wherein a liquid crystal compound and / or a polymer thereof having polymeric groups are aligned in a horizontal direction relative to the plane of the polarizing film.

[13] The polarizing film of any of

[10] to

[12] shows a Burger peak in X-ray diffraction measurements.

[14] The polarizing film of any of

[10] to

[13] has a thickness of 0.1 to 10 μm.

[15] An optical stack having an alignment film on at least one side of a polarizing film as described in any of

[10] to

[14] .

[16] An optical laminate having an alignment film on one side and a transparent film on the other side of a polarizing film as described in any of

[10] to

[14] .

[17] Optical stacks such as

[15] or

[16] , wherein the alignment film system is an alignment film having hydroxyl groups.

[18] Optical stacks such as

[15] or

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

[19] An optical laminate as in

[18] , wherein the alignment film has a transparent substrate with active hydrogen groups on the opposite side of the polarizing film.

[20] An optical stack such as

[18] or

[19] , wherein the thickness of the alignment film is more than 0.01 μm and less than 0.2 μm.

[21] A circular polarizer having an optical stack and a phase difference film as described in any one of

[15] to

[20] .

[22] A flexible panel having a circular polarizer as in

[21] .

[23] A method for manufacturing a polarizing film, comprising: (1) The step of coating a polarizing film forming composition of any one of [1] to [9] onto a substrate having an alignment function, and (2) Step of curing the composition for forming a polarizing film coated on a substrate.

[24] A method for manufacturing an optical laminate, comprising: (a) The step of forming an alignment film on a substrate, and (b) The step of forming a polarizing film as described in any one of

[10] to

[14] on the alignment film.

[25] The method for manufacturing an optical laminate as described in

[24] further includes (c) the step of forming a transparent film on a polarizing film.

[0008] According to the present invention, a polarizing film forming composition is provided that can form a polarizing film with high adhesion to the alignment film and is not easily peeled off from the alignment film. Implementation

[0009] The embodiments of the present invention will now be described in detail. Furthermore, the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the invention.

[0010] [Composition for forming polarizing film] The polarizing film forming composition of the present invention is a composition that forms a polarizing film by curing, and contains at least a reactive additive having both polymerizable groups and active hydrogen reactive groups, and a dichroic pigment having polymerizable groups.

[0011] <Reactive Additives> The polarizing film forming composition of the present invention contains a reactive additive (hereinafter also simply referred to as "reactive additive") having both polymerizable groups and active hydrogen reactive groups, thereby forming a polarizing film with high adhesion to the alignment film. The reason for this effect is as follows: the polymerizable groups and active hydrogen reactive groups of the reactive additive bond to the polymerizable groups of the dichroic pigment in the polarizing film and the active hydrogen groups of the alignment film, respectively; the reactive additive can function as a binder connecting the polarizing film and the alignment film.

[0012] In this invention, a polymerizable group refers to a group that participates in a polymerization reaction. As a polymerizable group in this invention, a photopolymerizable group is preferred over a thermally polymerizable group. Examples of polymerizable groups in reactive additives include: vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, (meth)acryl, (meth)acryloxy, ethylene oxide, oxetyl, etc. Among these, from the viewpoint of ease of reaction control, preferred polymerizable groups are (meth)acryl, (meth)acryloxy, ethoxy, ethylene oxide, and oxetyl, more preferably (meth)acryl and (meth)acryloxy, and even more preferably (meth)acryloxy. The polymerizable group in these reactive additives can be a single type or a combination of two or more. Furthermore, in this invention, "(meth)acryl" refers to both methacryl and acryloxy.

[0013] There is no particular limitation on the number of polymerizable groups in the reactive additive, for example, it can be 1 to 20. From the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, it is preferable to have 2 or more polymerizable groups, more preferably 2 to 15. When the reactive additive has 2 or more polymerizable groups, these polymerizable groups can be the same or different.

[0014] In this invention, the "active hydrogen reactive group" in the reactive additive refers to a group that is reactive to groups with active hydrogen, such as carboxyl (-COOH), hydroxyl (-OH), and amine (-NH2). Examples of active hydrogen reactive groups in reactive additives include: epoxy groups, glycidyl groups, isocyanate groups, thioisocyanate groups, alkoxysilyl groups, azizolinyl groups, carbodiimide groups, aziridinyl groups, amide groups, maleic anhydride groups, etc. These active hydrogen reactive groups can be a single type or a combination of two or more. From the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, the preferred active hydrogen reactive group is at least one active hydrogen reactive group selected from the group consisting of epoxy group, glycidyl group, isocyanate group and alkoxysilyl group, more preferably alkoxysilyl group or isocyanate group, and even more preferably isocyanate group. Examples of alkoxysilyl groups include trimethoxysilyl, triethoxysilyl, tripropoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethoxyethylsilyl, and methoxydimethylsilyl. Among these, from the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, trimethoxysilyl and triethoxysilyl are preferred, with trimethoxysilyl being the most preferred.

[0015] There is no particular limitation on the number of active hydrogen reactive groups in the reactive additive, for example, it can be 1 to 20. From the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, it is preferable to have 2 or more, more preferably 2 to 10, and even more preferably 2 to 5. When the reactive additive has 2 or more active hydrogen reactive groups, these active hydrogen reactive groups can be the same or different.

[0016] In one embodiment of the present invention, as a reactive additive, from the viewpoint of easily controlling the reaction and easily improving the adhesion between the obtained polarizing film and the alignment film, it is preferable to be a compound having both at least one polymerizable group selected from the group consisting of vinyl and (meth)acrylic groups and at least one active hydrogen reactive group selected from the group consisting of epoxy, glycidyl, isocyanate and alkoxysilyl groups; more preferably, a compound having (meth)acrylic and isocyanate groups, and a compound having (meth)acrylic and alkoxysilyl groups; and even more preferably, a compound having (meth)acrylic and isocyanate groups.

[0017] Specific examples of reactive additives include: compounds containing (meth)acrylamide and epoxy groups, such as methacryloxyglycidyl ether and acrylamide glycidyl ether; compounds containing (meth)acrylamide and oxetane methacrylate, such as oxetane acrylate and oxetane methacrylate; compounds containing (meth)acrylamide and lactone groups, such as lactone acrylate and lactone methacrylate; and vinyl acezoline and isopropenyl acezoline, etc. Compounds having vinyl and acezoline groups; compounds having (meth)acrylic and isocyanate groups, such as methyl isocyanate acrylate, methyl isocyanate methacrylate, ethyl 2-isocyanate acrylate, and ethyl 2-isocyanate methacrylate; compounds having (meth)acrylic and alkoxysilane groups, such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropylmethyldimethoxysilane; and oligomers of these compounds. Other specific examples of reactive additives include compounds having vinyl or vinyl groups and anhydrides, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride. These reactive additives can be a single compound or a combination of two or more. Specific reactive additives include: methacryloxyglycidyl ether, acryloxyglycidyl ether, methyl isocyanate acrylate, methyl isocyanate methacrylate, vinyl methazolin, ethyl 2-isocyanate acrylate, ethyl 2-isocyanate methacrylate, 3-acryloxypropyltrimethoxysilane, and oligomers thereof.

[0018] From the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, the content of the reactive additive is preferably 2 to 200 parts by mass relative to 100 parts by mass of the dichroic pigment with polymerizable groups. Furthermore, from the viewpoint of easily further improving the adhesion between the obtained polarizing film and the alignment film, the content of the reactive additive is more preferably 5 parts by mass or more, more preferably 15 parts by mass or more, and especially preferably 30 parts by mass or more. From the viewpoint of easily improving the alignment of the obtained polarizing film, it 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. Furthermore, regarding the content of the reactive additive, from the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, it is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more, and 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 polarizing film forming composition. Also, from the viewpoint of easily improving the alignment of the obtained polarizing film, it 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. Moreover, in this invention, the so-called solid content of the polarizing film forming composition refers to the total amount of components obtained by removing the solvent contained therein, depending on the circumstances, from the polarizing film forming composition.

[0019] <Dichroic Pigments> The polarizing film forming composition of the present invention contains a dichroic pigment with polymerizable groups, thereby facilitating the formation of a polarizing film with high adhesion to the alignment film. In the present invention, a dichroic pigment refers to a pigment having the property that its absorbance along the long axis of the molecule differs from its absorbance along the short axis. The polymerizable groups in the aforementioned dichroic pigment can generally react with the polymerizable groups in the reactive additive to form bonds.

[0020] As a polymerizable group in a dichroic pigment, examples of polymerizable groups that are also used in reactive additives can be cited. Among these, from the viewpoint of ease of reaction control, preferred polymerizable groups are (meth)acrylyl, (meth)acryloxy, ethoxy, ethylene oxide, and oxetyl, more preferably (meth)acrylyl and (meth)acryloxy, and even more preferably (meth)acryloxy. The polymerizable group in a dichroic pigment can be a single type or a combination of two or more types, and preferably a polymerizable group that is the same as the polymerizable group in the reactive additive.

[0021] There is no particular limitation on the number of polymerizable groups in a dichroic pigment; one or more is acceptable. From the viewpoint of easily improving the orientation of the obtained 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] As a dichroic pigment with polymerizable groups, it is preferable to have a dichroic pigment with a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Furthermore, the dichroic pigment with polymerizable groups can be a non-liquid crystal compound, but from the viewpoint of easily improving the alignment of the obtained polarizing film, a liquid crystal compound exhibiting liquid crystal properties is preferred. Moreover, the dichroic pigment with polymerizable groups can be a single type or a combination of two or more types.

[0023] In a preferred embodiment of the present invention, the dichroic pigment having a polymerizable group may be a liquid crystal compound represented by the following formula (2): In equation (2), m represents an integer from 0 to 3; A1, A2, and A3 independently represent divalent aromatic groups that can have substituents; L1 and L2 independently represent single bonds, -CH2-, -CH2CH2-, -O-, -CH2O-, -OCH2-, -CO-, -COO-, -OCO-, -OCOO-, -CRc=CRd-, -C≡C-, -CRc=N-, -CONRc-, -NRcCO- or -N=N-, where Rc and Rd independently represent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms; Z1 represents a polymerizable group, and Z2 represents a hydrogen atom or a polymerizable group; Q1 and Q2 independently represent straight-chain or branched alkyl groups with 1 to 20 carbon atoms that may have substituents, alkenyl groups with 1 to 20 carbon atoms that may have substituents, or alkynyl groups with 1 to 20 carbon atoms that may have substituents. The -CH2- in these alkyl, alkenyl, or alkynyl groups may be replaced with -O-, -S-, or NRe-, where Re represents a hydrogen atom or an alkyl group with 1 to 4 carbon atoms. T1 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, or CONRf- or -NRf-, T2 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -CONRf-, -NRf-, or -NRg-. Here, Rf and Rg independently represent hydrogen atoms or alkyl groups with 1 to 4 carbon atoms. The alkyl group represented by Rg can form a ring with Q1 or Q2. A1-(L1-A2)m-L2-A3 contains at least one structure represented by -AX1-N=N-AX2- (where AX1 and AX2 represent divalent aromatic groups respectively). In the case of T2 being -NRg-, Z2 represents a hydrogen atom. Furthermore, the liquid crystal compound represented by formula (2) can be a single compound or a combination of two or more compounds.

[0024] In equation (2), m represents an integer from 0 to 3, preferably m represents an integer from 1 to 3.

[0025] In equation (2), A1, A2 and A3 independently represent divalent aromatic groups that can have substituents.

[0026] Examples of divalent aromatic groups include 1,4-epenylphenyl, naphth-1,4-diyl, and divalent heterocyclic groups that may have substituents. Examples of divalent heterocyclic groups include groups obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, thiazolyl, and benzothiazolyl. When A2 is a divalent heterocyclic group, it is preferable to have a structure with a molecular bond angle of substantially 180°, and more specifically, a thienothiazole structure formed by the condensation of two 5-membered rings.

[0027] Examples of substituents that can be present in a divalent aromatic group include: alkyl groups with 1 to 4 carbons such as methyl, ethyl, and butyl; alkoxy groups with 1 to 4 carbons such as methoxy, ethoxy, and butoxy; fluorinated alkyl groups with 1 to 4 carbons such as trifluoromethyl; cyano; nitro; halogen atoms such as chlorine and fluorine; and substituted or unsubstituted amino groups such as amino, diethylamino, and pyrrolidinyl (a substituted amino group refers to an amino group having one or two alkyl groups with 1 to 6 carbons, or an amino group having an alkyl dienyllium with 2 to 8 carbons formed by the bonding of two substituted alkyl groups; an unsubstituted amino group is -NH2). Furthermore, examples of alkyl groups with 1 to 6 carbons include: methyl, ethyl, propyl, butyl, pentyl, and hexyl. Examples of alkyldiyl groups with 2 to 8 carbon atoms include: ethane-1,2-diyl, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, and octane-1,8-diyl.

[0028] As a divalent aromatic group that may have substituents, it is preferably an unsubstituted or hydrogen-substituted 1,4-phenyl group with methyl or methoxy groups, or the aforementioned divalent heterocyclic group.

[0029] L1 and L2 independently represent single bonds, -CH2-, -CH2CH2-, -O-, -CH2O-, -OCH2-, -CO-, -COO-, -OCO-, -OCOO-, -CRc=CRd-, -C≡C-, -CRc=N-, -CONRc-, -NRcCO-, or -N=N-. Rc and Rd independently represent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. Examples of alkyl groups having 1 to 4 carbon atoms include methyl, ethyl, propyl, and butyl. L1 and L2 are preferably -COO-, -CH=CH-, -C≡C-, -CONH-, or -N=N-, with -COO-, -OCO-, or N=N- being particularly preferred.

[0030] Z1 is a hydrogen atom or a polymeric group, and Z2 is a hydrogen atom or a polymeric group. When both Z1 and Z2 are polymeric groups, Z1 and Z2 can be of the same type or different types, preferably of the same type, and even more preferably of the same polymeric group. Furthermore, the polymeric group can be in a polymerized state or in an unpolymerized state, preferably in an unpolymerized state.

[0031] Examples of polymerizable groups representing Z1 and Z2 include: vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, (meth)acryl, (meth)acryloxy, ethylene oxide, oxetyl, etc. Among these, from the viewpoint of easy control of the reaction, (meth)acryl, (meth)acryloxy, ethoxy, ethylene oxide, and oxetyl are preferred polymerizable groups, more preferably (meth)acryl and (meth)acryloxy, and even more preferably (meth)acryloxy.

[0032] Q1 and Q2 independently represent straight-chain or branched alkyl groups having 1 to 20 carbon atoms that may have substituents, alkenyl groups having 1 to 20 carbon atoms that may have substituents, or alkyne groups having 1 to 20 carbon atoms that may have substituents, wherein the -CH2- contained in such alkyl, alkenyl, or alkyne groups may be replaced with -O-, -S-, or NRe-.

[0033] Examples of alkyl groups having 1 to 20 carbon atoms include: methylene, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl. Preferred are propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, and tetradecyl. More preferably are butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl.

[0034] Examples of alkenyl groups having 1 to 20 carbon atoms include: vinyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, tadeceneyl, and icoseneyl. More preferably are propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, and tetradecenyl. Even more preferably are butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodeceneyl, and trideceneyl.

[0035] Examples of alkyne groups having 1 to 20 carbon atoms include: alkyne, ...

[0036] Examples of substituents that can be present in the above-mentioned alkyl, alkenyl, or ynyl groups include: cyano; halogen groups such as fluorine, chloro, and bromine. As described above, the alkyl, alkenyl, or ynyl group is preferably an unsubstituted alkyl, alkenyl, or ynyl group, and more preferably an unsubstituted linear alkyl, alkenyl, or ynyl group.

[0037] The Re in the above example represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of alkyl groups having 1 to 4 carbon atoms, as mentioned above, include methyl, ethyl, butyl, etc.

[0038] T1 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, or -CONRf- or -NRf-. T2 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -CONRf-, -NRf-, or -NRg- only when Z2 is a hydrogen atom. Here, Rf and Rg independently represent hydrogen atoms or alkyl groups with 1 to 4 carbon atoms. The alkyl group represented by Rg can form a ring with Q1 or Q2. Among them, A1-(L1-A2)m-L2-A3 contains at least one structure represented by -AX1-N=N-AX2- (where AX1 and AX2 respectively represent divalent aromatic groups). When T2 is -NRg-, Z2 represents a hydrogen atom. As for the divalent aromatic groups represented by AX1 and AX2, examples can be given of groups that are the same as the divalent aromatic groups represented by A1 and A2 mentioned above.

[0039] In one embodiment of the present invention, examples of compounds represented by formula (2) include compounds represented by formulas (2-1) to (2-115) below. The compound represented by formula (2) is preferably a structure containing -AX1 -N=N-AX2 -N=N-AX3 - (where AX1 and AX2 are the same as defined above; AX3 represents a divalent aromatic group). As the divalent aromatic group represented by AX3, groups identical to AX1 and AX2 can be cited. In one embodiment of the present invention, AX1, AX2, and AX3 are preferably divalent aromatic hydrocarbon groups with 6 to 12 carbon atoms, or divalent aromatic heterocyclic groups with 6 to 12 carbon atoms having a sulfur atom or a nitrogen atom. More preferably, at least one of AX1, AX2, and AX3 is a divalent aromatic hydrocarbon group with 6 to 12 carbon atoms, such as phenyl or naphthyl. Furthermore, the compounds represented by formulas (2-1) to (2-115) below may be used in one or in combination of two or more.

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] The compound represented by formula (2) can be manufactured by combining its structure with well-known organic synthesis reactions (such as condensation reaction, esterification reaction, Williamson reaction, Ulmann reaction, Witte reaction, Schiff base formation reaction, benzylation reaction, sage reaction, Suzuki-Miyaura reaction, Negishi reaction, Kumada reaction, Hiyama reaction, Buchwald-Hartwig reaction, Fred-Cleift reaction, Heck reaction, hydroxyl reaction, etc.) as recorded in Method der Organischen Chemie, Organic Reactions, Organic Syntheses, Comprehensive Organic Synthesis, and New Experimental Chemistry Lectures.

[0051] From the viewpoint that the content of the dichroic pigment with polymerizable groups can easily improve the adhesion and dichroic ratio of the obtained polarizing film to the alignment film, it is acceptable to have 1 to 99 parts by mass relative to 100 parts by mass of the solid content of the composition for forming the polarizing film, preferably 2 parts by mass or more, and more preferably 3 parts by mass or more. Furthermore, from the viewpoint that it can easily improve the alignment of the obtained polarizing film, it is preferable to have 80 parts by mass or less, more preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 10 parts by mass or less. Furthermore, the dichroism ratio refers to the ratio of the absorption intensities of two linearly polarized rays that vibrate perpendicularly to each other when incident on the polarizing film. It is defined as the ratio (AV / AH) of absorbance along the extinction axis (measured with perpendicular incidence) to absorbance along the transmission axis. The transmission axis (polarization axis) is the direction of polarization of the component of incident light that passes through the polarizing film, and the extinction axis (absorption axis) is the direction of polarization of the component of incident light that is absorbed by the polarizing film.

[0052] The polarizing film forming composition of the present invention may contain, in addition to the dichroic pigment having polymerizable groups (hereinafter also referred to as the first dichroic pigment), a dichroic pigment without polymerizable groups (hereinafter also referred to as the second dichroic pigment) as long as it does not impair the effect of the present invention.

[0053] The second dichroic pigment can be any pigment that does not impair the effects of the present invention and is not particularly limited. Examples include acridine pigments, cyanine pigments, anthocyanin pigments, naphthalene pigments, azo pigments, and anthraquinone pigments. Among these, azo pigments are preferred. Examples of azo pigments include monoazo pigments, diazo pigments, triazo pigments, tetraazo pigments, and pizoazo pigments, with diazo pigments and triazo pigments being more preferred. The second dichroic pigment can be a single pigment or a combination of two or more.

[0054] In the case where the composition for forming the polarizing film of the present invention contains a second dichroic pigment in addition to the first dichroic pigment, the content of the first dichroic pigment relative to the total amount of the dichroic pigments (the total amount of the first and second dichroic pigments) is preferably 30% by mass or more, more preferably 60% by mass or more, further preferably 80% by mass or more, and even more preferably 90% by mass or more. If the content of the first dichroic pigment is at or above the above-mentioned lower limit, the ratio of dichroic pigments that can react with the polymerizable groups in the reactive additives becomes higher, thereby making it easier to improve the adhesion between the obtained polarizing film and the alignment film. The above-mentioned upper limit of content is not particularly limited and can be 100% by mass or less.

[0055] Furthermore, when the polarizing film forming composition of the present invention contains a second dichroic pigment in addition to the first dichroic pigment, the total amount of dichroic pigment contained in the polarizing film forming composition (the total amount of the first dichroic pigment and the second dichroic pigment) relative to 100 parts by mass of the solid component of the polarizing film forming composition may, for example, be more than 1 part by mass and less than 99 parts by mass. From the viewpoint of easily improving the dichroic ratio of the obtained polarizing film, it is preferably more than 2 parts by mass, more preferably more than 3 parts by mass. Also, from the viewpoint of easily improving the orientation of the obtained polarizing film, it is preferably less than 80 parts by mass, more preferably less than 50 parts by mass, and even more preferably less than 25 parts by mass, and most preferably less than 10 parts by mass.

[0056] <Liquid Crystal Compounds> From the viewpoint of easily improving the adhesion between the obtained polarizing film and the alignment film, and easily improving the alignment, the polarizing film forming composition of the present invention preferably contains, in addition to reactive additives and dichroic pigments, a liquid crystal compound having polymerizable groups. A liquid crystal compound refers to a compound exhibiting liquid crystal properties. Furthermore, the liquid crystal compound having polymerizable groups in the present invention does not include dichroic pigments having polymerizable groups.

[0057] Examples of polymerizable groups in liquid crystal compounds include groups exemplified as polymerizable groups in reactive additives. Among these, from the viewpoint of easy control of the reaction, preferred polymerizable groups are (meth)acrylyl, (meth)acryloxy, ethoxy, ethylene oxide, and oxetyl, more preferably (meth)acrylyl and (meth)acryloxy, and even more preferably (meth)acryloxy. The polymerizable group in the liquid crystal compound can be a single type or a combination of two or more, preferably the same polymerizable group as the polymerizable group in the reactive additive and the polymerizable group in the dichroic pigment.

[0058] Liquid crystal compounds with polymerizable groups can be thermotropic liquid crystals or lyotropic liquid crystals, but are preferably thermotropic liquid crystals. Furthermore, liquid crystal compounds with polymerizable groups can be thermotropic liquid crystal compounds displaying nematic liquid crystal phases or thermotropic liquid crystal compounds displaying lamellae liquid crystal phases. From the viewpoint of obtaining higher polarization characteristics, the liquid crystal compound with polymerizable groups in this invention is preferably a thermotropic liquid crystal compound displaying a lamellae liquid crystal phase, and more preferably a thermotropic liquid crystal compound displaying a higher-order lamellae liquid crystal phase. More preferably, it is a thermotropic liquid crystal compound displaying a lamellae B phase, lamellae D phase, lamellae E phase, lamellae F phase, lamellae G phase, lamellae H phase, lamellae I phase, lamellae J phase, lamellae K phase, or lamellae L phase, and even more preferably, it is a thermotropic liquid crystal compound displaying a lamellae B phase, a lamellae F phase, or a lamellae I phase. If the liquid crystal phase formed by the liquid crystal compound having polymerizable groups is such a high-order stratified phase, it is easy to obtain a polarizing film with higher polarization performance. Furthermore, such a polarizing film with higher polarization performance yields a Bourger peak originating from a high-order structure such as a hexagonal or crystalline phase in X-ray diffraction measurements. This Bourger peak originates from the periodic structure of molecular alignment, and films with a periodic interval of 3-6 Å can be obtained. From the viewpoint of obtaining higher polarization characteristics, it is preferable when the polarizing film of the present invention contains a polymer of the polymerizable liquid crystal polymerized in a stratified phase state.

[0059] In one embodiment of the present invention, the liquid crystal compound having a polymerizable group may be a compound represented by the following formula (1): In equation (1), X1 and X2 independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be replaced by a halogen atom, an alkyl group with 1 to 4 carbon atoms, a fluoroalkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, a cyano group, or a nitro group. The carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfur atom, or a nitrogen atom. At least one of X1 and X2 is a 1,4-phenyl group that may have substituents or a cyclohexane-1,4-diyl group that may have substituents. n can be 1 to 3. From the perspective of liquid crystal properties, n is preferably 2 or more. When n is 2 or more, X1 and X2 can be the same or different. Y1 are mutually independent linking bases that are either single bonds or divalent; U1 represents a hydrogen atom or a polymeric group; U2 represents a polymerizable group; W1 and W2 are independent linking bases that are either single-bonded or divalent; V1 and V2 independently represent alkadiyl groups with 1 to 20 carbon atoms that can have substituents, wherein the -CH2- group constituting the alkadiyl group can be substituted with -O-, -CO-, -S-, or NH-. In compound (1), W1-(X1-Y1)n-X2-W2 usually does not have the structure represented by -AX1-N=N-AX2-(AX1 and AX2 represent divalent aromatic groups respectively). Furthermore, the compound represented by formula (1) can be used alone or in combination of two or more.

[0060] In the compound represented by formula (1), X1 and X2 independently represent divalent aromatic groups or divalent alicyclic hydrocarbon groups that may have substituents. At least one of X1 and X2 represents a 1,4-epylphenyl group or a cyclohexane-1,4-diyl group that may have substituents. Preferably, X1 and X2 are 1,4-epylphenyl groups or cyclohexane-1,4-diyl groups that may have substituents, and more preferably trans-cyclohexane-1,4-diyl. Examples of substituents that may be present in the 1,4-epylphenyl group or the cyclohexane-1,4-diyl group include alkyl groups with 1 to 4 carbon atoms such as methyl, ethyl, and butyl, cyano groups, and halogen atoms such as chlorine and fluorine atoms; preferably, they are unsubstituted. Furthermore, in equation (1), when n is 2 or more and Y1 has the same structure, it is preferable that at least one of X1 and X2 has a different structure. When n is 2 or more and at least one of X1 and X2 has a different structure, there is a tendency to easily exhibit the properties of a lamellae liquid crystal.

[0061] Y1 is an independent single bond or a divalent linker. The divalent linker is preferably -CH2CH2-, -CH2O-, -CH2CH2O-, -COO-, -OCOO-, -N=N-, -CRa=CRb-, -C≡C-, -CRa=N-, or -CO-NRa-. Ra and Rb independently represent hydrogen atoms or alkyl groups with 1 to 4 carbon atoms. Y1 is more preferably -CH2CH2-, -COO-, or a single bond, and Y2 is more preferably -CH2CH2- or CH2O-. Furthermore, when n is 2 or more in formula (1) and X1 and X2 are all of the same structure, it is preferable that Y1 has a different bonding configuration. When n is 2 or more and Y1 has a different bonding configuration, there is a tendency to exhibit lamellae-type liquid crystal properties.

[0062] U2 is a polymerizable group. U1 is a hydrogen atom or a polymerizable group, preferably a polymerizable group. Preferably, both U1 and U2 are polymerizable groups, and more preferably, both are free radical polymerizable groups. Examples of polymerizable groups include: vinyl, ethoxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, ethylene oxide, oxetyl, etc. Among these, acryloxy, methacryloxy, ethoxy, ethylene oxide, and oxetyl are preferred, and acryloxy is even more preferred. The polymerizable group represented by U1 and the polymerizable group represented by U2 may be different from each other, but are preferably of the same type. Furthermore, the polymerizable group can be in a polymerized state or an unpolymerized state, preferably an unpolymerized state.

[0063] V1 and V2 independently represent alkyldiyl groups with 1 to 20 carbon atoms that may have substituents. The -CH2- group constituting the alkyldiyl group can be substituted with -O-, -CO-, -S-, or NH-. Examples of alkyldiyl groups include: methylene, ethyl, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10-diyl, tetradecane-1,14-diyl, and eicosane-1,20-diyl. V1 and V2 are preferably alkyldiyl groups with 2 to 12 carbon atoms, and more preferably alkyldiyl groups with 6 to 12 carbon atoms.

[0064] Examples of substituents that the alkyl diene may include cyano groups and halogen atoms. The alkyl diene is preferably unsubstituted, and more preferably an unsubstituted straight-chain alkyl diene.

[0065] W1 and W2 are independent linking bases that are either single-bonded or divalent. W1 and W2 are preferably -O-, -S-, -COO-, or -OCOO-, and more preferably single-bonded or -O-.

[0066] As for the liquid crystal compound having a polymerizable group, there is no particular limitation as long as it is a polymeric liquid crystal compound having at least one polymerizable group and exhibiting liquid crystal properties; known polymeric liquid crystal compounds can be used. As a liquid crystal compound having a polymerizable group, a polymeric liquid crystal compound exhibiting lamellar liquid crystal properties is preferred, and a compound exhibiting higher-order lamellar liquid crystal properties is even more preferred. As a structure that readily exhibits lamellar liquid crystal properties, a molecular structure having asymmetry in its molecular structure is preferred; specifically, a polymeric liquid crystal compound having the structure represented by formulas (Aa) to (Ai) and exhibiting lamellar liquid crystal properties is even more preferred. From the viewpoint of readily exhibiting higher-order lamellar liquid crystal properties, a structure represented by any one of formulas (Aa), (Ab), and (Ac) is further preferred, especially a structure represented by formula (Aa) or (Ac). Here, * in the following formulas denotes a bond.

[0067]

[0068] In one embodiment of the present invention, examples of compounds 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 the trans form.

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] Of these, preferably at least one is selected from the group consisting of compounds represented by formulas (1-2), (1-3), (1-4), (1-5), (1-6), (1-7), (1-8), (1-13), (1-14), (1-15), (1-16), and (1-17). A 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 manufactured, for example, by the known methods described in Lub et al. Recl.Trav.Chim.Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

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

[0077] When the polarizing film composition of the present invention contains a liquid crystal compound having a polymerizable group, the total amount of the dichroic pigment having a polymerizable group and the liquid crystal compound having a polymerizable group is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 80 parts by mass or more, and preferably 100 parts by mass or less, more preferably 98 parts by mass or less, and even more preferably 95 parts by mass or less, relative to 100 parts by mass or less. If the total amount of the dichroic pigment having a polymerizable group and the liquid crystal compound having a polymerizable group is above or below the above-mentioned lower limit and below the upper limit, it is easier to improve the alignment of the obtained polarizing film.

[0078] The polarizing film forming composition of the present invention may contain, in addition to the liquid crystal compound having polymerizable groups (hereinafter also referred to as the first liquid crystal compound), a liquid crystal compound without polymerizable groups (hereinafter also referred to as the second liquid crystal compound) as long as it does not impair the effect of the present invention.

[0079] There are no particular limitations on the second liquid crystal compound. For example, compounds represented by formula (1) in which U1 and U2 are both hydrogen atoms can be cited.

[0080] When the composition for forming the polarizing film of the present invention contains a second liquid crystal compound in addition to the first liquid crystal compound, the content of the first liquid crystal compound relative to the total amount of the liquid crystal compounds (the total amount of the first and second liquid crystal compounds) is preferably 30% by mass or more, more preferably 60% by mass or more, further preferably 80% by mass or more, and even more preferably 90% by mass or more. If the content of the first liquid crystal compound is at or above the above-mentioned lower limit, the ratio of liquid crystal compounds that can react with the polymerizable groups in the reactive additives becomes higher, thereby making it easier to improve the adhesion between the obtained polarizing film and the alignment film. The above-mentioned upper limit of content is not particularly limited and can 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 the first liquid crystal compound, the total amount of 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) relative to 100 parts by mass of the solid content of the polarizing film forming composition is, for example, more than 1 part by mass and less than 99 parts by mass, preferably more than 20 parts by mass, more preferably more than 40 parts by mass, more preferably more than 60 parts by mass, more preferably more than 70 parts by mass, even more preferably more than 80 parts by mass, and preferably less than 98 parts by mass, more preferably less than 95 parts by mass.

[0082] <Non-liquid crystal compounds> In addition to reactive additives, dichroic pigments, and liquid crystal compounds as appropriate, the polarizing film forming composition of the present invention may further contain a non-liquid crystal compound having a polymerizable group. 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 obtained polarizing film is easily improved. Examples of polymerizable groups include groups that are the same as those exemplified as polymerizable groups in reactive additives. Among these, from the viewpoint of ease of reaction control, preferred polymerizable groups are (meth)acrylyl, (meth)acryloxy, ethoxy, ethylene oxide, and oxetyl, more preferably (meth)acrylyl and (meth)acryloxy, and even more preferably (meth)acryloxy. The polymerizable group in the non-liquid crystal compound may be a single type or a combination of two or more types, preferably a polymerizable group that is the same as the polymerizable group in the dichroic pigment or liquid crystal compound.

[0083] There is no particular limitation on the number of polymerizable groups in a non-liquid crystal compound; for example, it can be 1 to 20. From the viewpoint of easily improving the film strength of the obtained polarizing film, 2 to 10 groups are preferred, and more preferably 3 to 6 groups. When a non-liquid crystal compound has two or more polymerizable groups, these polymerizable groups can be the same or different from each other.

[0084] The preferred non-liquid crystal compound having a polymerizable group is one that is itself uncolored or does not absorb visible light, is miscible with dichroic pigments having polymerizable groups and, if applicable, liquid crystal compounds having polymerizable groups, and does not hinder the formation of the liquid crystal state displayed by the dichroic pigments having polymerizable groups and, if applicable, the liquid crystal compounds having polymerizable groups. Furthermore, 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 with polymerizable groups include monofunctional (meth)acrylates and polyfunctional (meth)acrylates. Since monofunctional and polyfunctional acrylates are non-liquid crystal compounds with polymerizable groups, they are preferably those that do not possess a liquid crystal structure. Furthermore, monofunctional and polyfunctional acrylates may contain an amino carbamate structure, an amino group structure, an epoxy structure, an ethylene glycol structure, or a polyester structure within their molecules. Moreover, in this invention, the term "(meth)acrylate" refers to both methacrylates and acrylates.

[0086] Examples of monofunctional (meth)acrylates include: alkyl esters of (meth)acrylate with 4 to 16 carbon atoms, β-carboxyalkyl esters of (meth)acrylate with 2 to 14 carbon atoms, alkylated phenyl esters of (meth)acrylate with 2 to 14 carbon atoms, methoxy polyethylene glycol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, and isobutyl esters of (meth)acrylate.

[0087] As a polyfunctional (meth)acrylate, a 2- to 6-functional (meth)acrylate is preferred. Examples of difunctional (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-methylpentyl glycol di(meth)acrylate, etc.

[0088] Examples of 3- to 6-functional acrylates include: trimethylolpropane tri(meth)acrylate; pentaerythritol tri(meth)acrylate; tri(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; reactants of pentaerythritol tri(meth)acrylate with acid anhydrides; reactants of dipentaerythritol penta(meth)acrylate with acid anhydrides; reactants of tripentaerythritol hepta(meth)acrylate with acid anhydrides; and caprolactone-modified acrylates. Trimethylolpropane tri(meth)acrylate; caprolactone-modified pentaerythritol tri(meth)acrylate; caprolactone-modified tri(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 tetra(meth)acrylate Pentylenetetroxide pentamethacrylate; caprolactone-modified pentapentaerythritol hexamethacrylate; caprolactone-modified pentapentaerythritol heptamethacrylate; caprolactone-modified pentapentaerythritol octamethacrylate; the reaction product of caprolactone-modified pentapentaerythritol trimethacrylate and acid anhydride; the reaction product of caprolactone-modified dipentaerythritol pentamethacrylate and acid anhydride; and caprolactone-modified pentapentaerythritol heptamethacrylate and acid anhydride, etc. Furthermore, caprolactone modification refers to the introduction of caprolactone ring-opening forms or ring-opening polymers between the alcohol-derived portion of the (meth)acrylate compound and the (meth)acryloxy group.

[0089] When the polarizing film forming composition of the present invention contains a non-liquid crystal compound having a polymerizable group, the content of the non-liquid crystal compound, from the viewpoint of easily improving the film strength of the obtained polarizing film, 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 polarizing film forming composition. Furthermore, from the viewpoint of easily improving the alignment of the obtained polarizing film, it 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.

[0090] <Polymerization Initiator> The polarizing film forming composition of the present invention may further contain a polymerization initiator. The polymerization initiator is a compound that can initiate the polymerization reaction of compounds containing polymerizable groups (reactive additives and dichroic pigments containing polymerizable groups, and, where appropriate, liquid crystal compounds and non-liquid crystal compounds containing polymerizable groups) contained in the polarizing film forming composition. There are no particular limitations on the polymerization initiator, as long as it is a compound that can initiate the polymerization reaction of compounds containing polymerizable groups; known photopolymerization initiators can be used. Specific examples include photopolymerization initiators that generate active free radicals by light irradiation or photopolymerization initiators that generate acids. Photopolymerization initiators can be used alone or in combination of two or more.

[0091] Examples of photopolymerization initiators that generate active free radicals include: benzoin-based compounds, acetophenone-based compounds, hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, oxime ester-based compounds, phosphine oxide-based compounds, and azo compounds, which are self-destructive photopolymerization initiators; as well as benzophenone-based compounds, phenyl ketone-based compounds, benzoin ether-based compounds, benzoin ketal-based compounds, dibenzocycloheptanone-based compounds, anthraquinone-based compounds, benzoin ketone-based compounds, and 9-oxosulfuron-methyl-2-ethylheptanone-based compounds. Hydrogen-abstracting photopolymerization initiators, including compounds such as halogenated acetophenone compounds, dialkoxyacetophenone compounds, halogenated diimidazole compounds, halogenated tris(II) compounds, and tris(II) compounds. Examples of photopolymerization initiators that produce acids include monazite and strontium salts. Among these photopolymerization initiators, photopolymerization initiators that generate active free radicals by light irradiation are preferred. From the viewpoint of excellent reaction efficiency at low temperatures, self-destructive photopolymerization initiators are preferred, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0092] Examples of benzoin compounds 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-dioxolino-1-(4-methylthiopheno)propane-1-one, 2-benzyl-2-dimethylamino-1-(4-dioxolinophenyl)butane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propane-1-one, 1-hydroxycyclohexylphenyl one, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1-one.

[0094] Examples of oxime ester compounds include: 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-octanedione benzoyl oxime)], acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetylgoxime), etc.

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

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

[0097] Examples of phenyl ketone compounds include: diethoxyacetophenone, 2-methyl-2-dioxolino-1-(4-methylthiopheno)propane-1-one, 2-benzyl-2-dimethylamino-1-(4-dioxolinophenyl)butane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propane-1-one, 1-hydroxycyclohexylphenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1-one.

[0098] Examples of trichloromethyl compounds include: 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-trichloromethyl, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-trichloromethyl, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-trichloromethyl, and 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)] Vinyl]-1,3,5-trisyl, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-trisyl, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)vinyl]-1,3,5-trisyl, 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)vinyl]-1,3,5-trisyl, etc.

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

[0100] When the polarizing film forming composition of the present invention contains a polymerization initiator, the content of the polymerization initiator can be appropriately adjusted according to the type and amount of the polymerizable compound contained in the polarizing film forming composition participating in the polymerization reaction. The content of the polymerization initiator is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the solid content of the polarizing film forming composition, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass.

[0101] <Other Additives> The polarizing film forming composition of the present invention may contain other additives as needed, provided that the effect of the present invention is not impaired. Examples of other additives include: sensitizers, polymerization inhibitors, leveling agents, etc.

[0102] (Sensitizer) The composition for forming the polarizing film may contain a sensitizer. A photosensitizer is preferred as the sensitizer. Examples of such sensitizers include ketone or 9-oxothiophene. ketone compounds (e.g., 2,4-diethyl-9-oxosulfuron) 2-Isopropyl-9-oxosulfur (etc.), anthracene or anthracene compounds with substituents such as alkyl ethers (e.g., dibutoxyanthracene), phenanthrene or fluorene.

[0103] When the composition for forming a polarizing film contains a sensitizer, it promotes the polymerization reaction of the compounds containing polymerizable groups (reactive additives and dichroic pigments containing polymerizable groups, and liquid crystal compounds containing polymerizable groups and non-liquid crystal compounds containing polymerizable groups, depending on the situation) contained in the composition, which easily improves the film strength of the obtained polarizing film.

[0104] When the polarizing film forming composition of the present invention contains a photosensitizer, from the viewpoint that the content of the sensitizer is such that it can promote the polymerization reaction without impairing the orientation of the obtained polarizing film, 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 polarizing film forming composition.

[0105] (Polymerization inhibitor) Examples of polymerization inhibitors include: hydroquinone or hydroquinones with alkyl ethers or other substituents, catechols with alkyl ethers or other substituents such as butylcatechol, pyrogallols, free radical scavengers such as 2,2,6,6-tetramethyl-1-piperidinoxy radicals, thiophenols, β-naphthylamines or β-naphthols, etc.

[0106] When the polarizing film forming composition of the present invention contains a polymerization inhibitor, polymerization can be carried out without disrupting the alignment of the dichroic pigment having polymerizable groups and, depending on the circumstances, the liquid crystal compound having polymerizable groups. When the polarizing film forming composition of the present invention contains a polymerization inhibitor, from the viewpoint that the content of the polymerization inhibitor can allow polymerization without disrupting the alignment of the dichroic pigment having a polymerizable group and the liquid crystal compound having a polymerizable group, which may be present in the case, 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 polarizing film forming composition.

[0107] (Leveling agent) The composition for forming a polarizing film may contain a leveling agent. A leveling agent is an additive that adjusts the flowability of the composition to make the film obtained by coating the composition flatter. Examples of such leveling agents include organic modified polysiloxane oils, polyacrylates, or perfluoroalkyls. Specific examples include: DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Dow Corning Toray), 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 Advanced Materials Japan Ltd.), fluorinert (registered trademark) FC-72, fluorinert FC-40, fluorinert FC-43, fluorinert FC-3283 (all manufactured by Sumitomo 3M), MEGAFAC (registered trademark) R-08, MEGAFAC R-30, MEGAFAC R-90, MEGAFAC F-410, MEGAFAC F-411, MEGAFAC F-443, MEGAFAC F-445, MEGAFAC F-470, MEGAFAC F-477, MEGAFAC F-479, MEGAFAC F-482, MEGAFAC F-483 (all manufactured by DIC), Eftop (trade name) EF301, Eftop EF303, Eftop EF351, Eftop EF352 (all manufactured by Mitsubishi Materials Electronics & Chemicals), Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40, SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade name E1830, trade name E5844 (manufactured by Daikin Precision Chemical Research Institute Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353, and BYK-361N (all manufactured by BM Chemie Co., Ltd.), etc. Among them, polyacrylate-based leveling agents or perfluoroalkyl-based leveling agents are preferred.

[0108] When the polarizing film forming composition of the present invention contains a leveling agent, from the viewpoint of improving alignment and easily making the obtained polarizing film smooth, the solid content of the polarizing film forming composition is preferably 0.01 to 30 parts by weight, more preferably 0.03 to 10 parts by weight, and even more preferably 0.05 to 8.0 parts by weight, relative to 100 parts by weight. Furthermore, the polarizing film forming composition may contain one or more leveling agents.

[0109] Solvent From the viewpoint of facilitating the coating of the composition for forming a polarizing film, the composition for forming a polarizing film of the present invention preferably further contains a solvent. Preferably, the solvent is an organic solvent capable of dissolving the components contained in the composition for forming a polarizing film of the present invention, and more preferably an organic solvent inert to the polymerization reaction. Examples of solvents include: alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, 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 pentyl 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 amine solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinedione. These organic solvents can be used alone or in combination of two or more.

[0110] When the polarizing film forming composition of the present invention contains a solvent, the concentration of the solid component in the polarizing film forming composition of the present invention is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. If the concentration of the solid component is above the above lower limit, the thickness of the obtained polarizing film will not become too thin, and it is easy to obtain the dichroism required for the polarizing film. If it is below the above upper limit, the viscosity of the polarizing film forming composition becomes lower, and there is a tendency for the coating thickness of the composition to be less uneven.

[0111] <Composition for forming polarizing film> In one embodiment of the present invention, when the composition for forming the polarizing film of the present invention also contains a liquid crystal compound in addition to the reactive additives and dichroic pigments, it is preferable to satisfy the following formula (X): {(A)+(B)} / (C)≧0.7 (X) In equation (X), (A) indicates the mass of the dichroic pigment with polymerizable groups in the composition for forming a polarizing film. (B) indicates the mass of the liquid crystal compound with polymerizable groups in the composition for forming a polarizing film. (C) represents the total mass of the dichroic pigment and the total mass of the liquid crystal compound in the composition for forming the polarizing film. Furthermore, regarding the total mass of the dichroic pigment, when the dichroic pigment contains both a first dichroic pigment having polymerizable groups and a second dichroic pigment not having polymerizable groups, it represents the total mass of the first dichroic pigment and the second dichroic pigment. Similarly, regarding the total mass of the liquid crystal compound, when the liquid crystal compound contains both a first liquid crystal compound having polymerizable groups and a second liquid crystal compound not having polymerizable groups, it represents the total mass of the first liquid crystal compound and the second liquid crystal compound.

[0112] When the polarizing film forming composition contains a liquid crystal compound having polymerizable groups, if the polarizing film forming composition of the present invention satisfies formula (X), that is, the ratio {(A)+(B)} / (C) is 0.7 or more, the polymerizable groups of the reactive additive can easily react with the polymerizable groups of the dichroic pigment or the liquid crystal compound, thus easily improving the adhesion between the obtained polarizing film and the alignment film. As for the above ratio {(A)+(B)} / (C), from the viewpoint of easily further improving the adhesion of the obtained polarizing film, it is more preferably 0.8 or more, more preferably 0.9 or more, and even more preferably 0.95 or more, with the upper limit of the above ratio being 1 or less. Furthermore, if the above ratio is 1, the polarizing film forming composition of the present invention may not contain dichroic pigments without polymerizable groups or liquid crystal compounds without polymerizable groups.

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

[0114] The method for manufacturing the polarizing film forming composition of the present invention is not particularly limited. For example, it can be manufactured by uniformly mixing the components constituting the polarizing film forming composition using a mixing and stirring device or the like.

[0115] [Polarizing film] The polarizing film of this invention is a cured form of the polarizing film forming composition of this invention. It can be obtained by polymerizing the polymerizable compounds contained in the composition, namely, reactive additives and dichroic pigments with polymerizable groups, and, depending on the circumstances, liquid crystal compounds with polymerizable groups and non-liquid crystal compounds with polymerizable groups. Furthermore, a polarizing film refers to a film that decomposes unpolarized incident light into two orthogonal polarizing components, allowing one polarizing component to pass through and absorbing the other polarizing component. The axis of the transmitted polarizing component is called the transmission axis, and the axis of the absorbed polarizing component is called the absorption axis.

[0116] The polarizing film of this invention is a cured composition of a polarizing film forming material containing a reactive additive having both polymerizable groups and active hydrogen reactive groups, and a dichroic pigment having polymerizable groups. 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 groups of the reactive additive and the polymerizable groups of the dichroic pigment forming the polarizing film form bonds through a polymerization reaction within the polarizing film; and the active hydrogen reactive groups in the reactive additive can react with the alignment film to form bonds. Furthermore, when the alignment film has a transparent substrate on the opposite side from the polarizing film, the active hydrogen reactive groups of the reactive additive in the polarizing film can also react with the transparent substrate to form bonds, thereby achieving the aforementioned effect. Here, it is believed that the active hydrogen reactive groups in the reactive additive react with the active hydrogen groups in the alignment film or the aforementioned transparent substrate to form bonds. The reason why the reactive groups of active hydrogen within 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 bonds, is believed to be as follows: The polarizing film of the present invention is a coating-type polarizing film. More specifically, the reason is that the polarizing film of the present invention is formed by coating the alignment film with a polarizing film forming composition containing unreacted reactive additives, etc., and then curing the polarizing film forming composition. Therefore, during the curing of the polarizing film forming composition, the polymerizable groups of the reactive additives can react with the polymerizable groups in the dichroic pigment.

[0117] As the polarizing film of the present invention, it is preferably a dichroic pigment having polymerizable groups and / or its polymers aligned in the horizontal direction relative to the plane of the polarizing film. Furthermore, when the polarizing film forming composition of the present invention contains a liquid crystal compound having polymerizable groups, the polarizing film of the present invention is preferably a liquid crystal compound having polymerizable groups and / or its polymers aligned in the horizontal direction relative to the plane of the polarizing film. The polarizing film with alignment properties described above can be obtained by coating a polarizing film forming composition onto a substrate with alignment function as described below, so that the dichroic pigment and the liquid crystal compound are aligned in the horizontal direction relative to the plane of the substrate, and then hardened in the aligned state.

[0118] The polarizing film of the present invention is preferably an alignment film that displays the Bühler peak in X-ray diffraction measurements.

[0119] Regarding the thickness of the polarizing film, from the viewpoint of the alignment of the dichroic pigment with polymerizable groups and, depending on the case, the liquid crystal compound with polymerizable groups, the thickness 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. If the thickness of the polarizing film is above or below the aforementioned lower limit, the dichroic pigment and, depending on the case, the liquid crystal compound are difficult to align in the perpendicular alignment direction, thus making it easier to improve the alignment order. Furthermore, if the thickness of the polarizing film is below the aforementioned upper limit, the dichroic pigment and, depending on the case, the liquid crystal compound are difficult to align randomly, thus making it easier to improve the alignment order. The thickness of the polarizing film can be measured using an interferometer, laser microscope, or stylus-type thickness gauge.

[0120] [Manufacturing Method of Polarizing Film] The polarizing film of the present invention can be formed on a substrate by the following method, which includes: coating the polarizing film forming composition of the present invention on a substrate having an alignment function, and curing the polarizing film forming composition coated on the substrate.

[0121] In one embodiment of the present invention, when the polarizing film forming composition of the present invention contains a solvent, the polarizing film of the present invention can be formed on a substrate by coating the polarizing film forming composition of the present invention on a substrate having an alignment function, and then removing the solvent contained in the composition, thereby hardening the polarizing film forming composition with the solvent removed.

[0122] As a substrate with alignment function, there are no particular limitations as long as it has alignment function; examples include glass substrates and membrane substrates. Membrane substrates are preferred, and from the viewpoint of continuous manufacturing, long, cylindrical membranes are even more preferred. Examples of resins constituting the membrane substrate include: polyethylene, polypropylene, and other polyolefins such as northoene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethyl methacrylate; polyacrylate; cellulose esters such as triacetin, diacetin, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polyurethane; polyether ether; polyetherketone; polyphenylene sulfide and polyphenylene ether; and other resins. In one embodiment of the present invention, the substrate with alignment function can be the following alignment membrane.

[0123] Examples of commercially available cellulose ester substrates include: "Fujitac Film" (manufactured by Fujifilm Inc.); "KC8UX2M", "KC8UY" and "KC4UY" (manufactured by Konica Minolta Opto Inc.). Examples of commercially available cyclic olefin resins include: "Topas" (registered trademark) (manufactured by Ticona Corporation, Germany), "ARTON" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by ZEON Corporation, Japan), and "APEL" (registered trademark) (manufactured by Mitsui Chemicals Co., Ltd.). These cyclic olefin resins can be used to form films using known methods such as solvent casting and melt extrusion, thereby creating substrates. Commercially available cyclic olefin resin substrates can also be used. Examples of commercially available cyclic olefin resin substrates include: "S-SINA" (registered trademark), "SCA40" (registered trademark) (manufactured by Sekisui Chemicals Co., Ltd.), "ZEONOR FILM" (registered trademark) (manufactured by Optes Co., Ltd.), and "ARTON FILM" (registered trademark) (manufactured by JSR Corporation).

[0124] Regarding the thickness of the aforementioned substrate, it is preferable to be thinner from the viewpoint of practical operability, and thicker from the viewpoint of strength or processability. In one embodiment of the present invention, the thickness of the aforementioned substrate is preferably 5 μm to 300 μm, more preferably 20 μm to 200 μm. Furthermore, by transferring a dichroic pigment having polymerizable groups and, where appropriate, a liquid crystal compound having polymerizable groups to the polarizing film obtained by peeling it off from the substrate, a polymer can be transferred to the polarizing film. This allows the polarizing film of the present invention to be applied only to polarizing plates used in image display panels, thereby achieving a further thin-film effect for polarizing plates used in image display panels.

[0125] Methods for coating the polarizing film forming composition of the present invention onto a substrate having alignment function include, for example, extrusion coating, direct gravure coating, reverse gravure coating, capillary (CAP) coating, or die coating; and coating methods using coating machines such as dip coaters, bar coaters, or spin coaters. Among these, in the case of continuous roll-to-roll coating, coating methods such as microgravure coating, inkjet coating, slot coater, or die coating are preferred. In the case of coating monolithic substrates such as glass, spin coating, which offers higher uniformity, is preferred. In the case of roll-to-roll coating, an alignment film forming composition can also be coated onto the substrate to form an alignment film, and then the polarizing film forming composition can be continuously coated onto the obtained alignment film.

[0126] Methods for removing solvents contained in the composition for forming a polarizing film coated on a substrate include: natural drying, ventilation drying, heating drying, and reduced pressure drying. Solvent removal is preferably carried out under conditions where the polymerizable compounds contained in the composition for forming the polarizing film do not polymerize. The drying temperature is preferably 0–250°C, more preferably 20–150°C, and even more preferably 50–130°C. The drying time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. The following compositions for forming photo-alignment films and alignment polymer compositions can also be dried in the same manner.

[0127] The curing of the polarizing film forming composition coated on a substrate is carried out by polymerizing the polymerizable compounds (reactive additives, dichroic pigments, and, depending on the case, liquid crystal compounds and non-liquid crystal compounds) contained in the polarizing film forming composition. The polymerization of the aforementioned polymerizable compounds can be selected according to the type of polymerizable group. If the polymerizable group is photopolymerizable, it can be polymerized by photopolymerization; if the polymerizable group is thermally polymerizable, it can be polymerized and cured by thermal polymerization. The polarizing film of the present invention is preferably polymerized by photopolymerization. When polymerization is carried out by photopolymerization, polymerization can be performed at low temperatures, and it is also easy to manufacture industrially. The light irradiated in the photopolymerization process is appropriately selected according to the type and amount of polymerizable groups in the compounds containing polymerizable groups contained in the polarizing film forming composition. Specific examples include: light or active electron beams selected from one or more of the group consisting of visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, and gamma rays. Among these, ultraviolet light is preferred from the perspective of easy control of the polymerization reaction and its use as a photopolymerization device, which is widely used in this field.

[0128] Examples of light sources for the aforementioned active energy lines include: low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten filament lamps, gallium lamps, excimer lasers, LED (light-emitting diode) light sources that emit light in the wavelength range of 380~440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0129] The intensity of ultraviolet (UV) irradiation is typically 10–3,000 mW / cm². Preferably, the UV irradiation intensity is within the wavelength range effective for activating the photopolymerization initiator. The irradiation time is typically 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. If irradiation is performed once or multiple times at this intensity, the cumulative light intensity is 10–3,000 mJ / cm², preferably 50–2,000 mJ / cm², and more preferably 100–1,000 mJ / cm².

[0130] [Optical stack] The present invention also includes an optical stack in which at least one side of the polarizing film of the present invention has an alignment film. <Alignment film> In this invention, the alignment film system comprises a film of polymeric compounds, referring to a film having an alignment-restricting force that aligns the liquid crystal displaying compound in a desired direction. The alignment film facilitates the liquid crystal alignment of the liquid crystal displaying compound (dichroic pigments with polymeric groups and / or, depending on the situation, liquid crystal compounds with polymeric groups) contained in the polarizing film. The states of liquid crystal alignment, such as horizontal alignment, vertical alignment, mixed alignment, and tilted alignment, vary depending on the properties of the alignment film and the liquid crystal displaying compound, and any combination thereof can be selected. For example, if the alignment film system is a material exhibiting horizontal alignment as an alignment-restricting force, the liquid crystal displaying compound can form a horizontal or mixed alignment; if it is a material exhibiting vertical alignment, the liquid crystal displaying compound can form a vertical or tilted alignment. The terms "horizontal," "vertical," etc., refer to the direction of the long axis of the liquid crystal displaying compound when the polarizing film plane is used as a reference. Horizontal alignment refers to the alignment of the long axis of a liquid crystal compound in a direction parallel to the plane of the polarizing film. Here, "parallel" means an angle of 0° ± 20° relative to the plane of the polarizing film. Vertical alignment refers to the alignment of the long axis of a liquid crystal compound in a direction perpendicular to the plane of the polarizing film. Here, "vertical" means an angle of 90° ± 20° relative to the plane of the polarizing film.

[0131] As an alignment constraint force, when the alignment film is formed from an alignment polymer, it can be arbitrarily adjusted by surface conditions or friction conditions; when it is formed from a photoalignment polymer, it can be arbitrarily adjusted by polarized light irradiation conditions, etc. Furthermore, the alignment of liquid crystals can also be controlled by selecting the surface tension or liquid crystal properties of the compound that displays liquid crystal properties.

[0132] As an alignment film formed on at least one side of a polarizing film, it is preferably insoluble in the solvent used when forming the polarizing film on the alignment film, and also has heat resistance in the heat treatment used for solvent removal or liquid crystal alignment.

[0133] In one embodiment of the present invention, the alignment film is preferably an alignment film having active hydrogen groups. When the alignment film has active hydrogen groups, the active hydrogen groups of the alignment film react with the active hydrogen reactive groups of the reactive additive contained in the polarizing film to form bonds. In this way, the alignment film and the polarizing film are bonded through the reactive additive, which makes it easier to improve the adhesion between the polarizing film and the alignment film, and makes it easier to obtain an optical laminate that is not easily peeled off between the polarizing film and the alignment film.

[0134] Examples of active hydrogen groups include carboxyl groups (-COOH), hydroxyl groups (-OH), and amino groups (-NH2). These active hydrogen groups can be a single type or a combination of two or more. The active hydrogen groups in the alignment film are preferably selected based on the reactive hydrogen groups of the reactive additives contained in the polarizing film. For example, if the reactive additives in the polarizing film have isocyanate groups as active hydrogen groups, the alignment film preferably has hydroxyl and / or amino groups; if the reactive additives in the polarizing film have alkoxysilyl groups as active hydrogen groups, the alignment film preferably has hydroxyl groups. In one embodiment of the present invention, the alignment film is preferably an alignment film containing hydroxyl groups. In one embodiment of the present invention, the optical laminate is preferably formed on at least one side of a polarizing film containing a reactive additive having an isocyanate group or an alkoxysilyl group, and more preferably formed on at least one side of a polarizing film containing a reactive additive having an isocyanate group, and ...

[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 exhibiting sufficient alignment confinement force, and 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 thinning the optical stack.

[0136] In another embodiment of the present invention, the alignment film may be an alignment film without active hydrogen groups. In this case, the alignment film preferably has a transparent substrate with active hydrogen groups on the opposite side of the polarizing film. When the alignment film has a transparent substrate with active hydrogen groups on the opposite side of the polarizing film, even if the alignment film does not have active hydrogen groups, the active hydrogen reactive groups of the reactive additive in the polarizing film and the active hydrogen groups in the transparent substrate can react to form bonds. Therefore, the polarizing film and the transparent substrate are bonded by the reactive additive while the alignment film is sandwiched in the middle, which easily improves the adhesion between the polarizing film and the alignment film and makes it easy to obtain an optical laminate that is not easily peeled off between the polarizing film and the alignment film.

[0137] As a transparent substrate with active hydrogen groups, it is not particularly limited as long as it has active hydrogen groups. Examples include: cellulose ester films such as triacetyl cellulose (TAC) films, cyclic olefin polymer (COP) films whose surfaces are modified by corona discharge irradiation, polymethyl methacrylate (PMMA) films whose surfaces are modified by corona discharge irradiation, and polyethylene terephthalate (PET) films whose surfaces are modified by corona discharge irradiation.

[0138] In one embodiment of the present invention, where the alignment film has a transparent substrate with active hydrogen groups on the opposite side to the polarizing film, the thickness of the alignment film is preferably 0.01 μm to 0.2 μm, and more preferably 0.15 μm or less, from the viewpoint of easily improving the adhesion between the polarizing film and the alignment film. If the thickness of the alignment film is as thin as 0.2 μm or less, even if the alignment film does not have active hydrogen groups and the polarizing film and the alignment film cannot directly form bonds through reactive additives, the reactive additives in the polarizing film can easily form bonds with the active hydrogen groups in the transparent substrate. As a result, the adhesion between the polarizing film and the alignment film is easily improved.

[0139] In one embodiment of the present invention, the alignment film without active hydrogen groups is preferably a poly(meth)acrylic acid-based structure or a polysilazane structure.

[0140] In one embodiment of the present invention, even when the alignment film is an alignment film with active hydrogen groups, from the viewpoint of easily improving the adhesion between the alignment film and the polarizing film, the alignment film may also have a transparent substrate on the opposite side of the polarizing film, more preferably a transparent substrate with active hydrogen groups.

[0141] In one embodiment of the present invention, examples of alignment films include alignment films containing alignment polymers, photoalignment films, groove alignment films, and extended films extending in the alignment direction. In the case of application to long, cylindrical films, photoalignment films are preferred in terms of the ease of controlling the alignment direction.

[0142] Alignment films can be obtained by coating an alignment polymer composition containing an alignment polymer and a solvent, or a photoalignment film forming composition containing a polymer or monomer with a photoreactive group and a solvent, onto a substrate, removing the solvent contained in the alignment polymer composition or photoalignment film forming composition, and then subjecting the solvent-removed alignment polymer composition or photoalignment film forming composition to rubbing treatment or polarized light irradiation treatment.

[0143] There are no particular limitations on the substrates for coating alignment polymer compositions and photoalignment film forming compositions; examples include glass, plastic sheets, plastic films, and light-transmitting films. Examples of light-transmitting films include: polyolefin films such as polyethylene, polypropylene, and norethene-based polymers; polyethylene terephthalate films; polymethacrylate films; polyacrylate films; cellulose ester films such as triacetin cellulose films; polyethylene naphthalate films; polycarbonate films; polyurethane films; polyether ether films; polyetherketone films; polyphenylene sulfide films; or polyphenylene ether films. The above-mentioned substrates can be those whose surfaces have been modified by corona discharge irradiation. The aforementioned substrate is preferably a transparent substrate. From the viewpoint of easily improving the adhesion between the alignment film and the polarizing film, it is more preferably a transparent substrate with active hydrogen groups, such as a cellulose ester film like triacetyl cellulose film, a cyclic olefin polymer film whose surface is modified by corona discharge irradiation, a polymethyl methacrylate (PMMA) film whose surface is modified by corona discharge irradiation, or a polyethylene terephthalate (PET) film whose surface is modified by corona discharge irradiation.

[0144] Examples of directional polymers included in directional polymer compositions include: polyamides and gelatin having intramolecular amide bonds; polyimides having intramolecular imine bonds and their hydrolysates such as polyamide acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyazole, polyethylimide, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylate. Among these, polyvinyl alcohol is preferred from the viewpoint of easily improving the adhesion between the polarizing film and the directional film. These directional polymers can be used alone or in combination of two or more.

[0145] Examples of solvents that can be used in oriented polymer compositions include: water; alcohols such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl pentyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbons such as pentane, hexane, and heptane; aromatic hydrocarbons such as toluene and xylene; nitrile solvents such as acetonitrile; ethers such as tetrahydrofuran and dimethoxyethane; and chlorinated hydrocarbons such as chloroform and chlorobenzene. These solvents can be used alone or in combination of two or more.

[0146] The concentration of the directional polymer in the directional polymer composition is only required to be within the range where the directional polymer can be completely dissolved in the solvent, and is preferably 0.1 to 20% by mass relative to the solid content of the solution, more preferably 0.1 to 10% by mass.

[0147] The alignment polymer composition can be directly used with commercially available alignment membrane materials. Examples of commercially available alignment membrane materials include Sunever (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.) and Optomer (registered trademark) (manufactured by JSR Corporation).

[0148] The methods for coating an orientation polymer composition onto a substrate and for removing the solvent contained in the orientation polymer composition can be exemplified by methods similar to those used in the manufacture of polarizing films, namely, coating a polarizing film forming composition onto a substrate and removing the solvent.

[0149] As a friction method, one example is the following: a film of oriented polymer formed on the surface of an anti-diffusion layer by coating an oriented polymer composition onto an anti-diffusion layer and annealing it is brought into contact with a friction roller wound with a friction cloth and rotating.

[0150] Photoalignment films can be obtained by coating a composition (a composition for forming a photoalignment film) containing a polymer, oligomer, or monomer with photoreactive groups and a solvent onto a substrate, drying to remove the solvent, and then irradiating with polarized light, preferably ultraviolet (UV) light. Photoalignment films are superior in that the direction of the alignment constraint force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light. The polymer or monomer containing a photoreactive group 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, a polymer with a weight average molecular weight of 5000 or more is preferred. A photoreactive group refers to a group that generates liquid crystal alignment ability upon irradiation. Specifically, it is a photoreaction that, upon irradiation, generates a molecular alignment-inducing or isomerizing reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, thus becoming the origin of liquid crystal alignment ability. Among these photoreactive groups, those that induce dimerization or photocrosslinking reactions are preferred in terms of superior alignment properties. As a photoreactive group capable of generating the above reactions, it is preferred to have unsaturated bonds, especially double bonds, and more preferably a group having at least one selected from the group consisting of carbon-carbon double bonds (C=C), carbon-nitrogen double bonds (C=N), nitrogen-nitrogen double bonds (N=N), and carbon-oxygen double bonds (C=O).

[0151] Examples of photoreactive groups with C=C bonds include vinyl, polyenyl, linyl, linazolyl, stilbazonium, chalcone, and cinnamyl. Examples of photoreactive groups with C=N bonds include groups with aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups with N=N bonds include azophenyl, azonaphthyl, aromatic heterocyclic azo, diazo, and formazanyl, or those with an azobenzene oxide as their basic structure. Examples of photoreactive groups with C=O bonds include benzophenone, coumarin, anthraquinone, and maleic anthracene diimide. These groups may have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, and halogenated alkyl groups.

[0152] The solvent contained in the composition for forming a photo-alignment film is preferably a solvent that dissolves polymers and monomers having photoreactive groups. Examples of such solvents include solvents used in alignment polymer compositions.

[0153] The concentration of the polymer or monomer with photoreactive groups in the composition for forming the photoalignment film can be appropriately adjusted according to the type of polymer or monomer with photoreactive groups or the thickness of the photoalignment film to be manufactured, preferably 0.2% by mass or more, and more preferably in the range of 0.3% to 10% by mass. Furthermore, the composition for forming the photoalignment film may contain polymeric materials such as polyvinyl alcohol or polyimide, or photosensitizers, within a range that does not significantly impair the properties of the photoalignment film.

[0154] As a method for coating a photoalignment film forming composition onto a substrate, a method similar to that for coating an alignment polymer composition onto a substrate can be cited. As a method for removing solvent from a self-coated photoalignment film forming composition, a method similar to that for removing solvent from a self-alignment polymer composition can be cited.

[0155] As a method of irradiating polarized light, it can be in the form of directly irradiating the photo-alignment film formed from a composition coated on a substrate by removing the solvent, or in the form of irradiating the substrate with polarized light, allowing the polarized light to pass through. Furthermore, the polarized light is preferably substantially parallel light. The wavelength of the irradiated polarized light is preferably in the wavelength range where the photoreactive groups of the polymer or monomer having photoreactive groups can absorb light energy. Specifically, it is preferably UV (ultraviolet light) in the wavelength range of 250-400 nm. Examples of light sources used in this polarized irradiation include: xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, KrF, ArF, and other ultraviolet lasers, with high-pressure mercury lamps, ultra-high-pressure mercury lamps, or metal halide lamps being more preferred. The luminous intensity of ultraviolet light with a wavelength of 313 nm from these lamps is relatively high and preferred. Polarized light can be irradiated by passing light from the above-mentioned light sources through a suitable polarizing element. As the polarizing element, a polarizing filter or a polarizing prism or wire grid type polarizing element such as Glan-Thompson or Glan-Taylor can be used.

[0156] Furthermore, if shielding is applied during rubbing or polarized light irradiation, multiple regions (patterns) with different liquid crystal alignment directions can also be formed.

[0157] <Transparent film> The optical laminate of the present invention can further have a transparent film. In one embodiment of the present invention, the optical laminate preferably has an alignment film on one side of the polarizing film and a transparent film on the other side. There are no particular limitations on the transparent film; for example, it can be a resin film. Examples of resins constituting the resin film include water-soluble polymers and photocurable resins. Examples of water-soluble polymers include: polyacrylamide polymers; polyvinyl alcohol, ethylene-vinyl alcohol copolymers, (meth)acrylic acid or its anhydride-vinyl alcohol copolymers, etc.; carboxyvinyl polymers; polyvinylpyrrolidone; starches; sodium alginate; or polyethylene oxide polymers. Examples of photocurable resins include: acrylic resins, urethane resins, urethane acrylate resins, epoxy resins, and polysiloxane resins.

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

[0159] [Manufacturing Method of Optical Laminates] The optical laminate of the present invention can be manufactured by a method comprising the following steps: forming an alignment film on a substrate, preferably the aforementioned transparent substrate, and more preferably a transparent substrate having active hydrogen groups; forming a polarizing film on the alignment film; and, depending on the circumstances, being manufactured by a method further comprising the following steps: forming a transparent thin film on the polarizing film formed on the alignment film.

[0160] [Circular polarizing plate] This invention also includes a circular polarizer having the optical stack and retardation film of this invention. The circular polarizer is a functional layer that allows only right-handed or left-handed circularly polarized light components to pass through by stacking a λ / 4 retardation film on a linear polarizer. The circular polarizer of this invention may have a retardation film on either side of the optical stack. In this invention, it is preferable to achieve fully circularly polarized light across all wavelengths, but this is not always necessary in practice; therefore, the circular polarizer of this invention also includes a luminous polarizer.

[0161] In one embodiment of the present invention, the phase retardation film is preferably a phase retardation film that displays the phase retardation property of the birefringence Δn(λ) of light with wavelength λ nm as expressed by the following equations (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 that exhibits the retardation characteristics expressed by equations (1), (2) and (3) above. 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 delay at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

[0165] There is no particular limitation on the thickness of the retardation film; for example, it can be less than 100 μm. From the viewpoint of making displays thinner, it is preferable to be 0.5 μm to 20 μm, and more preferably 1 μm to 3 μm. Examples of such very thin retardation films with a thickness of 1 μm to 3 μm include polymer films that are cured in a state where polymeric liquid crystals are aligned.

[0166] The circular polarizing plate of this invention can be used in various display panels (or display devices). A display panel refers to a device or panel having display elements, including light-emitting elements or light-emitting devices as light sources. Examples of display panels include: liquid crystal display panels, organic electroluminescent (EL) display panels, inorganic electroluminescent (EL) display panels, touch panel display panels, electron emission display panels (e.g., field emission display panels (FED), surface conduction electron emission display panels (SED), electronic paper (display panels using electronic ink or electrophoretic elements), plasma display panels, projection display panels (e.g., grating light valve imaging system (GLV) display panels, display panels with digital micromirror devices (DMD)), and piezoelectric ceramic displays. Liquid crystal display panels also include any of transmissive liquid crystal display panels, transflective liquid crystal display panels, reflective liquid crystal display panels, direct-viewing liquid crystal display panels, and projection liquid crystal display panels. These display panels can be display panels for displaying two-dimensional images or stereoscopic display panels for displaying three-dimensional images. In particular, the circular polarizer of the present invention can be effectively used in liquid crystal display panels and organic electroluminescent (EL) display panels.

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

[0168] If the circular polarizing plate of the present invention is transferred to the above-mentioned display panels, preferably flexible panels, the state of the transfer area, such as step difference or uneven structure, can be largely unaffected, and a uniform circular polarizing plate can be applied to the above-mentioned display panels. [Example]

[0169] The present invention will be further described in detail below based on embodiments and comparative examples, but the present invention is not limited to the following embodiments. Unless otherwise specified, "%" and "parts" in the examples represent mass % and mass parts, respectively. First, the dichroic pigments and polymeric liquid crystal compounds used in the embodiments and comparative examples are disclosed.

[0170] <Dichroic Pigments> Dichroic pigments (2-1): Dichroic pigments (2-2): Dichroic pigment (A-4): Dichroic pigment (B-5):

[0171] The dichroic pigments (2-1) and (2-2) were synthesized according to the method described in Japanese Patent Application Publication No. 2019-172987. The dichroic pigments (A-4) and (B-5) are the dichroic pigments described in Japanese Patent Application Publication No. 2013-101328.

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

[0173] The polymeric liquid crystal compounds (1-6) and (1-8) were synthesized according to the method described in Japanese Patent Application Publication No. 2019-172987.

[0174] <Evaluation of Close Contact> The following method was used to evaluate the adhesion between the polarizing film and the alignment film in the optical stacks obtained in the embodiments and comparative examples.

[0175] (Peeling test) A 25 mm wide Sellotape (manufactured by Nichiban) with a length of 30 mm was attached to the front and back sides of the obtained optical laminate, respectively. A 90° peel test was performed on both the front and back sides. No peeling occurred between the alignment film and the polarizing film, designated as A; partial peeling occurred, designated as B; and complete peeling occurred, designated as C. The test results are shown in Table 1.

[0176] (Crosshatch experiment) The adhesion between the alignment film and the polarizing film in the obtained optical laminate was evaluated using the cross-scribing test (JIS "Checkerboard Adhesion Test") according to JIS D0202-1988. A 10×10 checkerboard pattern was created by cutting 2 mm intervals through the alignment film onto the transparent film surface of the optical laminate. Adhesive tape (25 mm wide, manufactured by Nichiban) was then completely adhered to the created checkerboard surface. The tape was then peeled off at a 90° angle relative to the surface. Based on the number of remaining checkerboard patterns after undone removal, those ≥90 / 100 were designated as A, those ≥80 / 100 as B, and those ≤79 / 100 as C. Furthermore, X-ray photoelectron spectroscopy (XPS) was used to confirm that the removal interface of the removed checkerboard patterns was between the alignment film and the polarizing film. The experimental results are shown in Table 1.

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

[0178] (Fabrication of optical laminates) 1. Formation of alignment films A 2% by mass aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was coated onto a triacetin cellulose (TAC) membrane (KC8UX2M, manufactured by Konica Minolta) cut to 80×80 mm using a rod coating method. The coating was then dried to form a dry coating film with a thickness of 0.1 μm. Subsequently, the surface of the obtained dry coating film was subjected to a friction treatment to form an alignment film with alignment restraint force. The friction treatment was performed using a semi-automatic friction device (trade name: LQ-008, manufactured by Changyang Institute of Technology Co., Ltd.) with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.) under the conditions of an indentation 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 coated onto the alignment film using a rod coating method. After drying in an oven at 120°C for 1 minute, it was rapidly cooled to room temperature, forming a dried coating film derived from the polarizing film forming composition 1 on the alignment film. The dichroic pigment and liquid crystal compound contained in the dried coating film were in a lamellar B phase liquid crystal state. Subsequently, the dried coating film was irradiated with ultraviolet light at an exposure dose of 2400 mJ / cm² (365 nm reference) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), thereby causing the dichroic pigment and liquid crystal compound contained in the dried coating film to polymerize while maintaining the liquid crystal state of the polymerizable liquid crystal composition, forming a polarizing film from the dried coating film. The thickness of the polarizing film at this time was measured using a laser microscope (OLS3000 manufactured by Olympus Co., Ltd.), and the result was 2.3 μm.

[0180] 3. X-ray diffraction measurement X-ray diffraction measurements were performed on the obtained polarizing film using an X'Pert PRO MPD (manufactured by Spectris Corporation). X-rays generated using Cu as a target and with an X-ray tube current of 40 mA and a tube voltage of 45 kV were incident through a fixed divergence slit of 1 / 2° from the friction direction (the friction direction of the alignment film beneath the polarizing film was determined beforehand). The measurement was performed in 2θ = 0.01671° steps within the scanning range of 2θ = 4.0–40.0°. A steep diffraction peak with a full width at half maximum (FWHM) of approximately 0.312° was obtained near 2θ = 20.08°. Similar results were obtained from incident radiation perpendicular to the friction direction. The order period (d) obtained from the peak position was approximately 4.42 Å, indicating the formation of a structure reflecting higher-order layered phases.

[0181] 4. Fabrication of optical laminates After corona treatment of the obtained polarizing film surface, an aqueous solution (viscosity: 92 cP) containing 7 parts of carboxyl-modified polyvinyl alcohol [Kuraray Poval KL318 manufactured by Kuraray (stock)] and 3.5 parts of water-soluble polyamide epoxy resin [Sumirez Resin 650 (30% by mass aqueous solution of solids content) obtained from Sumika Chemtex (stock)] as a thermal crosslinking agent was spin-coated onto the corona-treated surface. The aqueous solution was dried at 80°C for 5 minutes to form a transparent film with a thickness of 1 μm on the polarizing film.

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

[0183] (Fabrication of optical laminates) An optical laminate was fabricated in the same manner as in Example 1, except that polarizing film forming composition 2 was used instead of polarizing film forming composition 1, and the results were evaluated.

[0184] <Example 3> (Preparation of a composition for forming a polarizing film) The following components are mixed and stirred at 80°C for 1 hour to obtain composition 3 for forming a polarizing film. Dichroic pigment (2-2): 4.0 parts Reactive additive; LALOMER LR9000 (manufactured by BASF): 1.0 part Polymerizable liquid crystal compounds (1-6): 75 parts Polymerizable liquid crystal compounds (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 (Fabrication of optical laminates) An optical laminate was fabricated in the same manner as in Example 1, except that polarizing film forming composition 3 was used instead of polarizing film forming composition 1, and the results were evaluated.

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

[0186] <Example 6> Composition 2 for forming polarizing film was prepared in the same manner as in Example 2. Except for the alignment film being formed in the manner described below, the optical stack was fabricated in the same manner as in Example 1 and evaluated.

[0187] Formation of alignment film (Preparation of compositions for alignment film formation) The following components are mixed and stirred at 80°C for 1 hour to obtain a composition for alignment film formation. Photoalignment polymer: 2 parts o-xylene: 98 parts As the aforementioned photoalignment polymer, the polymer represented by the following formula described in Japanese Patent Application Publication No. 2013-033249 (number average molecular weight: approximately 28,000) is used. .

[0188] (Formation of alignment film) Using an 80×80 mm TAC film (KC8UX2M, manufactured by Konica Minolta Co., Ltd.) as a substrate, the surface of the substrate was corona treated, and the above-mentioned alignment film forming composition was coated onto the substrate. The coating was then dried at 120°C to obtain a dry coating. The dried coating was then irradiated with polarized UV light to form an alignment film with a thickness of 0.2 μm. The polarized UV treatment was performed using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) at an intensity of 100 mJ / cm² measured at a wavelength of 365 nm.

[0189] <Example 7> (Preparation of a composition for forming a polarizing film) The following components are mixed and stirred at 80°C for 1 hour to obtain composition 7 for polarizing film formation. Dichroic pigment (2-2): 4.0 parts Reactive additive; Karenz AOI (ethyl 2-isocyanate acrylate, manufactured by Showa Chemical Co., Ltd.): 2.0 parts Polymerizable liquid crystal compounds (1-6): 75 parts Polymerizable liquid crystal compounds (1-8): 25 parts Polymerization initiator; Irgacure 369: 6 parts Leveling agent; BYK-361N: 1.2 parts Solvent; Xylene: 450 parts (Fabrication of optical laminates) An optical laminate was fabricated in the same manner as in Example 1, except that polarizing film forming composition 7 was used instead of polarizing film forming composition 1, and the results were evaluated.

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

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

[0192] <Example 10> Except for changing the amount of reactive additives as described in Table 1, the polarizing film forming composition 10 was prepared in the same manner as in Example 2. Optical laminates were fabricated in the same manner as in Example 1, except that polarizing film forming composition 10 was used instead of polarizing film forming composition 10, and the results were evaluated. <Example 11> (Preparation of a composition for forming a polarizing film) The following components are mixed and stirred at 80°C for 1 hour to obtain composition 11 for forming a polarizing film. Dichroic pigment (2-2): 4.0 parts Reactive additive; KBM-5103 (3-Acryloyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.): 2.0 parts Polymerizable liquid crystal compounds (1-6): 75 parts Polymerizable liquid crystal compounds (1-8): 25 parts Polymerization initiator; Irgacure 369: 6 parts Leveling agent; BYK-361N: 1.2 parts Solvent; Xylene: 450 parts (Fabrication of optical laminates) An optical laminate was fabricated in the same manner as in Example 1, except that a polarizing film forming composition 11 was used instead of a polarizing film forming composition 11, and the laminate was evaluated.

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

[0194] (Fabrication of optical laminates) 1. Formation of alignment films Using a 50×50 mm glass substrate as the base material, a 2% by mass aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was coated onto the glass substrate by spin coating. The coating was then 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 film. The friction treatment was performed using a semi-automatic friction device (trade name: LQ-008, manufactured by Changyang Institute of Technology Co., Ltd.) with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.) under the conditions of an indentation 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 coated onto the alignment film using a spin coating method. After drying on a heating plate at 120°C for 3 minutes, it was rapidly cooled to room temperature, forming a dry coating of the polarizing film forming composition 11 on the alignment film. The polymeric liquid crystal compound contained in the dry coating is in a lamellae B phase liquid crystal state. Subsequently, the dry coating was irradiated with ultraviolet light using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.) at an exposure dose of 2400 mJ / cm2 (365 nm reference), thereby causing the polymeric liquid crystal compound contained in the dry coating to polymerize while maintaining the liquid crystal state of the polymeric liquid crystal composition, thus forming a polarizing film from the dry coating. The thickness of the polarizing film at this time was measured using a laser microscope (OLS3000 manufactured by Olympus Co., Ltd.), and the result was 1.7 μm.

[0196] "3. X-ray diffraction measurement" and "4. Fabrication of optical laminates" were carried out by fabricating optical laminates in the same manner as in Example 1 and then evaluating them.

[0197] <Comparative Example 2> Except for changing the dichroic pigment to (2-2), the polarizing film forming composition 13 was prepared in the same manner as in Comparative Example 1, and an optical laminate was fabricated in the same manner as in Example 1 for evaluation.

[0198] <Comparative Example 3> Except for using triacetyl cellulose (TAC) membrane (KC8UX2M, manufactured by Konica Minolta) as the substrate, an optical laminate was fabricated in the same manner as in Comparative Example 2 and evaluated.

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

[0200] [Table 1] dichroic pigment Reactive additives Liquid crystal compounds Non-liquid crystal compounds {(A)+(B)} / (C) Tightness Peel test Cross-line test Example 1 (2-1) 4.0 copies LR9000 2.0 copies (1-6) 75 copies (1-8) 25 copies - 1 A B Example 2 (2-2) 4.0 copies LR9000 2.0 copies (1-6) 75 copies (1-8) 25 copies - 1 A B Example 3 (2-2) 4.0 copies LR9000 1.0 copy (1-6) 75 copies (1-8) 25 copies DPHA 1.0 copy 1 A A Example 4 (2-2) 4.0 copies LR9000 0.08 copies (1-6) 75 copies (1-8) 25 copies - 1 B B Example 5 (2-2) 4.0 copies LR9000 4.0 copies (1-6) 75 copies (1-8) 25 copies - 1 A B Example 6 (2-2) 4.0 copies LR9000 2.0 copies (1-6) 75 copies (1-8) 25 copies - 1 A B Example 7 (2-2) 4.0 copies Karenz AOI 2.0 copies (1-6) 75 copies (1-8) 25 copies - 1 B B Example 8 (2-2) 40 copies LR9000 2.0 copies (1-6) 45 copies (1-8) 15 copies - 1 A B Example 9 (A-4) 27 copies (2-2) 13 copies LR9000 2.0 copies (1-6) 45 copies (1-8) 15 copies - 0.73 A B Example 10 (2-2) 4.0 copies LR9000 8.0 copies (1-6) 75 copies (1-8) 25 copies - 1 A A Example 11 (2-2) 4.0 copies KBM-5103 2.0 copies (1-6) 75 copies (1-8) 25 copies - 1 B B Comparative Example 1 (2-1) 4.0 copies - (1-6) 75 copies (1-8) 25 copies - 1 C C Comparative Example 2 (2-2) 4.0 copies - (1-6) 75 copies (1-8) 25 copies - 1 C C Comparative Example 3 (2-2) 4.0 copies - (1-6) 75 copies (1-8) 25 copies - 1 C C Comparative Example 4 (A-4) 27 copies (B-5) 13 copies LR9000 2.0 copies (1-6) 45 copies (1-8) 15 copies - 0.6 C C

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

Claims

1. A composition for forming a polarizing film, comprising a reactive additive having both a polymerizable group and an active hydrogen reactive group, a dichroic pigment having a polymerizable group, and a dichroic pigment without a polymerizable group, wherein the reactive additive functions as a binder connecting the polarizing film and the alignment film, and the dichroic pigment having a polymerizable group accounts for 30% to 100% by mass of the total amount of dichroic pigment, and the dichroic pigment without a polymerizable group accounts for 2% to 80% by mass of the total amount of dichroic pigment, wherein the dichroic pigment having a polymerizable group is a liquid crystal compound represented by the following formula (2): [In formula (2), m represents an integer from 0 to 3; A1, A2, and A3 independently represent divalent aromatic groups that may have substituents;] L1 and L2 independently represent single bonds, -CH2-, -CH2CH2-, -O-, -CH2O-, -OCH2-, -CO-, -COO-, -OCO-, -OCOO-, -CRc=CRd-, -C≡C-, -CRc=N-, -CONRc-, -NRcCO-, or -N=N-. Here, Rc and Rd independently represent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. Z1 represents a polymerizable group, and Z2 represents a hydrogen atom or a polymerizable group. Q1 and Q2 independently represent straight-chain or branched alkyl groups having 1 to 20 carbon atoms that may have substituents, alkylene groups having 1 to 20 carbon atoms that may have substituents, or alkylyn groups having 1 to 20 carbon atoms that may have substituents. The -CH2- in these alkyl, alkylene, or alkylyn groups may be replaced with -O-, -S-, or NRe-, where Re represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. T1 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, or CONRf- or -NRfCO-; T2 represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -CONRf-, -NRfCO-, or -NRg-. Here, Rf and Rg independently represent hydrogen atoms or alkyl groups with 1 to 4 carbon atoms. The alkyl group represented by Rg can form a ring with Q1 or Q2. A1-(L1-A2)m-L2-A3 contains at least one structure represented by -AX1-N=N-AX2- (where AX1 and AX2 represent divalent aromatic groups, respectively). When T2 is -NRg-, Z2 represents a hydrogen atom.

2. The polarizing film forming composition of claim 1, further comprising a liquid crystal compound having a polymerizable group.

3. The polarizing film forming composition of claim 2 satisfies the following formula: {(A)+(B)} / (C)≧0.7 (A): mass of dichroic pigment having polymerizable groups (B): mass of liquid crystal compound having polymerizable groups (C): total mass of dichroic pigment and liquid crystal compound.

4. The polarizing film forming composition of any one of claims 1 to 3, further comprising a non-liquid crystal compound having a polymerizable group.

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

6. The composition for forming a polarizing film as claimed in any one of claims 1 to 3, wherein the polymerizable group in the dichroic dye is (meth)acrylic.

7. The composition for forming a polarizing film as claimed in any one of claims 1 to 3, wherein the polymerizable group in the reactive additive is (meth)acrylic.

8. The composition for forming a polarizing film as claimed in claim 4, wherein the polymerizable group in the non-liquid crystal compound is (meth)acrylic.

9. The composition for forming a polarizing film according to any one of claims 1 to 3, wherein the content of the reactive additive is more than 2 parts by mass and less than 200 parts by mass relative to 100 parts by mass of the dichroic pigment having a polymerizable group.

10. A polarizing film, which is a cured form of the polarizing film forming composition of any one of claims 1 to 9.

11. A polarizing film formed from a cured copy of a polarizing film forming composition of any one of claims 1 to 9, wherein a dichroic pigment having polymerizable groups and / or its polymers are aligned in a horizontal direction relative to the plane of the polarizing film.

12. A polarizing film formed from a cured copy of a polarizing film forming composition of any one of claims 2 to 9, wherein a liquid crystal compound and / or a polymer thereof having polymeric groups are aligned in a horizontal direction relative to the plane of the polarizing film.

13. The polarizing film of any of the requests 10 to 12, which shows a Burger peak in X-ray diffraction measurements.

14. The polarizing film of any one of the claims 10 to 12 has a thickness of 0.1 to 10 μm.

15. An optical laminate having an alignment film on at least one side of a polarizing film as claimed in any one of claims 10 to 14.

16. An optical laminate having an alignment film on one side and a transparent film on the other side of a polarizing film as claimed in any one of claims 10 to 14.

17. The optical laminate of claim 15 or 16, wherein the alignment film is an alignment film having hydroxyl groups.

18. The optical stack of claim 15 or 16, wherein the alignment film has a poly(meth)acrylic acid structure or a polysilazane structure.

19. The optical laminate of claim 18, wherein the alignment film has a transparent substrate with active hydrogen groups on the opposite side of the polarizing film.

20. The optical laminate of claim 18, wherein the thickness of the alignment film is more than 0.01 μm and less than 0.2 μm.

21. A circular polarizer having an optical stack and a retardation film as claimed in any one of claims 15 to 20.

22. A flexible panel having a circular polarizer as claimed in claim 21.

23. A method for manufacturing a polarizing film, comprising: (1) coating a polarizing film forming composition of any one of claims 1 to 9 onto a substrate having an alignment function, and (2) curing the polarizing film forming composition coated onto the substrate.

24. A method for manufacturing an optical laminate, comprising: (a) forming an alignment film on a substrate, and (b) forming a polarizing film as claimed in any one of claims 10 to 14 on the alignment film.

25. The method for manufacturing an optical laminate as claimed in claim 24, further comprising (c) the step of forming a transparent thin film on a polarizing film.