TW202241980A - Composition for forming photo-alignment film, photo-alignment film, laminate and polarizing element capable of forming a photo-alignment film with good adhesion to a substrate and having an improved liquid stability - Google Patents

Abstract

The present invention provides a composition for forming a photo-alignment film, and the composition for forming a photo-alignment film can form a photo-alignment film with good adhesion to a substrate and has an improved liquid stability. The composition for forming a photo-alignment film of the present invention includes a photo-alignment polymer having a photoreactive group, a silane coupling agent, an acid and a solvent.

Description

Composition for forming photoalignment film, photoalignment film, laminate, and polarizing element

The invention relates to a composition for forming an optical alignment film, an optical alignment film, a laminate and a polarizing element.

A polarizing element comprising a laminate of a photoalignment film and a polarizing film laminated on a base material is known, and it is known that the photoalignment film of the polarizing element is formed from a photoalignment film containing a photoreactive group that undergoes a dimerization reaction It is formed by coating a substrate with a composition (Patent Document 1). With regard to such a laminate, attempts have been made to further improve the adhesion between the photoalignment film and the substrate, and to further suppress peeling. For example, Patent Document 2 discloses a liquid crystal alignment agent that can form a liquid crystal alignment film with good adhesion to a substrate, is suitable for retardation films, and includes a photoalignment polymer and a silane compound. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-102479 [Patent Document 2] Japanese Patent Laid-Open No. 2014-123091

[Problem to be solved by the invention]

However, for the composition for forming an optical alignment film as described above, in addition to the good adhesion between the optical alignment film obtained from the composition and the substrate, further improvement in the liquid stability of the composition for forming an optical alignment film is required. sex.

Therefore, an object of the present invention is to provide a composition for forming a photoalignment film, which can form a photoalignment film with good adhesion to a substrate and has improved liquid stability. [Technical means to solve the problem]

The inventors of the present invention conducted intensive research to solve the above-mentioned problems, and found that a composition for forming a photo-alignment film comprising a photo-alignment polymer having a photoreactive group, a silane coupling agent, an acid, and a solvent can solve the above-mentioned problems, The present invention has thus been accomplished. That is, the present invention includes the following preferred aspects.

[1] A composition for forming a photoalignment film, comprising a photoalignment polymer having a photoreactive group, a silane coupling agent, an acid, and a solvent. [2] The composition as described in [1], wherein the photo-alignment polymer has a photoreactive group that undergoes a dimerization reaction. [3] The composition as described in [1] or [2], wherein the photo-alignment polymer is a (meth)acrylic polymer. [4] The composition according to any one of [1] to [3], wherein the photo-alignment polymer further has a carboxyl group. [5] The composition according to any one of [1] to [4], wherein the weight average molecular weight of the photo-alignment polymer is not less than 10,000 and not more than 1,000,000. [6] The composition according to any one of [1] to [5], wherein the silane coupling agent has at least one group selected from the group consisting of primary amine groups and secondary amine groups. [7] The composition according to any one of [1] to [6], wherein the content of the silane coupling agent is not less than 0.5 parts by mass and not more than 30 parts by mass relative to 100 parts by mass of the photo-alignment polymer. [8] The composition according to any one of [1] to [7], wherein the acid contains at least one selected from the group consisting of formic acid, toluenesulfonic acid, acrylic acid and acetic acid. [9] The composition according to any one of [1] to [8], wherein the molar ratio of the acid to the silane coupling agent is 1 to 50. [10] A photoalignment film obtained by curing the composition described in any one of [1] to [9]. [11] A laminate comprising a substrate and the photo-alignment film as described in [10]. [12] The laminate described in [11], wherein the film thickness of the base material is not less than 1 μm and not more than 20 μm. [13] A polarizing element comprising a substrate, the photo-alignment film as described in [10], and a polarizing film. [14] The polarizing element described in [13], which has a thickness of not less than 1 μm and not more than 10 μm. [Effect of Invention]

According to the present invention, it is possible to provide a photoalignment film-forming composition capable of forming a photoalignment film with good adhesion to a substrate and having improved liquid stability.

Embodiments of the present invention will be described in detail below. In addition, the scope of the present invention is not limited to the embodiment described here, and various changes can be made in the range which does not deviate from the summary of this invention.

[Photoalignment Film Forming Composition] The composition for forming a photo-alignment film of the present invention includes a photo-alignment polymer having a photoreactive group, a silane coupling agent, an acid and a solvent.

[Photoalignment Polymer] The photo-alignment polymer of the present invention has a photoreactive group. The so-called photoreactive group refers to a group that generates liquid crystal alignment ability by irradiating light (light irradiation). Specifically, those related to photoreactions as sources of liquid crystal alignment ability, such as alignment induction or isomerization reaction of polymer molecules by irradiation with light, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, can be exemplified. base. As the photoreactive group, it is preferably a group having an unsaturated bond, especially a double bond, preferably having a group selected from a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond) , a base of at least one of the group consisting of nitrogen-nitrogen double bond (N=N bond) and carbon-oxygen double bond (C=O bond). The photoreactive group which a photoalignment polymer has may be 1 type, and may be 2 or more types.

As the photoreactive group having a C=C bond, for example, a vinyl group, a polyene group, a stilbene group, a styrylpyridinyl group, a styrylpyridinium group, a chalcone group, and a cinnamon group Acyl group, etc. As a photoreactive group which has a C=N bond, the group which has structures, such as an aromatic Schiff base and an aromatic hydrazone, is mentioned, for example. As the photoreactive group having an N=N bond, for example, azophenyl group, azonaphthyl group, aromatic heterocyclic azo group, disazo group, formazan group, and azobenzene group with The basis of structure, etc. As a photoreactive group which has a C=O bond, a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group etc. are mentioned, for example. These groups may have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, halogenated alkyl and the like. Among them, from the viewpoint of excellent alignment and reactivity, the photoalignment polymer preferably has a photoreactive group that undergoes a dimerization reaction or a photocrosslinking reaction, and more preferably has a photoreactive group that undergoes a dimerization reaction. base.

The so-called dimerization reaction refers to an addition reaction between two groups due to the action of light, typically a reaction in which a ring structure is formed. The dimerization-reactive group is a group containing a carbon-carbon double bond (C=C bond) or a carbon-oxygen double bond (C=O bond) that causes a dimerization reaction by light irradiation, and for example, : A group having a cinnamyl structure, a group having a chalcone structure, a group having a coumarin structure, a group having a benzophenone structure, a group having an anthracene structure, etc. Among them, the group having a cinnamoyl structure and the group having a chalcone structure are preferable, and the group having a cinnamoyl structure is more preferable in terms of easy control of reactivity and excellent alignment restriction force during photoalignment. . Furthermore, it is also advantageous in terms of easily obtaining a photo-alignment film having a low amount of polarized light irradiation required for photo-alignment and having excellent thermal stability and temporal stability, which has the above-mentioned structure.

In the present invention, a photo-alignment polymer is preferable in terms of easily obtaining a photo-alignment film composition having good adhesion to a substrate and having improved liquid stability. In order to have a photoreactive group that undergoes a dimerization reaction at the end of the polymer side chain, it is more preferable to include a group with a cinnamyl structure or a group with a chalcone structure at the end of the polymer side chain, and it is more preferable to have a group with a chalcone structure at the end of the polymer side chain. The end of the polymer side chain contains a group having a cinnamyl structure. Regarding the photo-alignment polymer, for example, a polymer having a structure represented by the following formula (A1') and/or a structure represented by the formula (A1'') in the side chain (hereinafter, these collectively referred to as "photo-alignment polymer (A)").

[式(A1')及式(A1'')中， k表示0或1。 L ¹表示單鍵或-O-。 L ²表示單鍵、-O-、-COO-、-OCO-、-N=N-、-CH=CH-或-CH ₂-。 R ¹、R ²及R ³分別獨立地表示氫原子、鹵素原子、鹵化烷基、鹵化烷氧基、氰基、硝基、烷基、烷氧基、芳基、烯丙氧基、烷氧基羰基、羧基、磺酸基、胺基或羥基，該羧基及該磺酸基可與鹼金屬離子形成鹽。 R ⁴表示氫原子、烷基或苯基。 *表示對聚合物主鏈之鍵結鍵] [chemical 1]

[In formula (A1') and formula (A1''), k represents 0 or 1. L ¹ represents a single bond or -O-. L ² represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH- or -CH ₂ -. R ¹ , R ² and R ³ independently represent hydrogen atom, halogen atom, halogenated alkyl, halogenated alkoxy, cyano, nitro, alkyl, alkoxy, aryl, allyloxy, alkoxy Carbonyl group, carboxyl group, sulfonic acid group, amino group or hydroxyl group, the carboxyl group and the sulfonic acid group can form a salt with an alkali metal ion. R ⁴ represents a hydrogen atom, an alkyl group or a phenyl group. *Indicates a bond to the polymer backbone]

In formula (A1') and formula (A1''), if L ² is a single bond, -O-, -COO-, -OCO-, -N=N-, -C=C- and -CH ₂ - Either one makes it easy to manufacture the photo-alignment polymer (A).

In formula (A1') and formula (A1''), if R ¹ , R ² and R ³ are each independently an alkyl group with 1 to 4 carbons or an alkoxy group with 1 to 4 carbons, it is easy to obtain Since it is easy to form a photo-alignment film with good adhesion to the base material and has improved liquid stability, the composition for a photo-alignment film is preferable. Examples of the alkyl groups represented by R ¹ , R ² and R ³ include methyl, ethyl, and butyl groups, and examples of the alkoxy groups include methoxy, ethoxy, and butoxy groups.

The main chain of the photo-alignment polymer (A) is not particularly limited. As the structure of the monomer units forming the main chain, for example, it may be selected from those represented by formula (M-1) or formula (M-2). (Meth)acrylate unit, (meth)acrylamide unit represented by formula (M-3) or formula (M-4), ethylene represented by formula (M-5) or formula (M-6) In the group consisting of ether unit, methyl styrene unit represented by formula (M-7) or formula (M-8), and vinyl ester unit represented by formula (M-9) or formula (M-10) By. In formulas (M-1) to (M-10), * represents a bond with the structure represented by formula (A1') or formula (A'') or a bond with the following spacer unit. Furthermore, in this specification, the term "main chain of the photo-alignment polymer (A)" refers to the longest molecular chain among the molecular chains of the photo-alignment polymer (A).

[Chem 2]

The main chain of the photo-alignment polymer (A) may be a homopolymer composed of one type of monomer unit, or may be a copolymer composed of two or more types of monomer units. When the main chain of the photo-alignment polymer (A) is a copolymer, it can be any combination of alternating, block, random, and graft.

Moreover, the structure of the monomer unit which forms the main chain of a photoalignment polymer (A) may be the silsesquioxane structure containing the repeating unit represented by following formula (M-11)-(M-16). In formulas (M-11) to (M-16), * represents a bond with the structure represented by formula (A1') or formula (A1'') or a bond with the following spacer unit.

[Chem 3]

In the formulas (M-11) to (M-16), R ⁵ represents an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, or a bond to another silicon atom via an oxygen atom. The alkyl group having 1 to 6 carbon atoms represented by R ⁵ may, for example, be methyl, ethyl, n-propyl, isopropyl or n-butyl, among which methyl and ethyl are preferred. The alkoxy group having 1 to 6 carbon atoms represented by R ⁵ may, for example, be methoxy, ethoxy, n-propoxy, isopropoxy or n-butoxy, among which methyl is preferred. Oxygen, Ethoxy.

In formulas (M-13) and (M-14), Ph represents a divalent benzene ring which may have a substituent (for example, a phenylene group, etc.). In formula (M-16), Cy represents a divalent cyclohexane ring which may have a substituent (for example, cyclohexane-1,4-diyl, etc.). n represents an integer of 1-4.

Among them, the main chain of the photo-alignment polymer (A) is easy to obtain a photo-alignment film composition with good adhesion to the substrate and a composition for a photo-alignment film with good liquid stability. It is preferably a structural unit represented by any one of formulas (M-1) to formula (M-16), more preferably a structural unit represented by any one of formulas (M-1) to (M-10). The structural unit further preferably contains a structural unit selected from the group consisting of (meth)acrylate units and (meth)acrylamide units represented by formulas (M-1) to (M-4). Furthermore, among all the structural units constituting the main chain, for example, a polymer having the largest ratio of structural units selected from the group consisting of (meth)acrylate units and (meth)acrylamide units may be referred to as "" (meth)acrylic polymers". In other words, the photo-alignment polymer in the present invention is preferably a (meth)acrylic polymer.

The monomer structural unit forming the main chain of the photoalignment polymer (A) as represented by any one of formula (M-1) to formula (M-16) can be directly combined with formula (A1') or formula (A1 The bonding of groups represented by '') can also be bonded via an appropriate spacer unit, ie, a linking group. In the case of bonding via a linking group, the linking group includes, for example, a carbonyloxy group (ester bond), an oxygen atom (ether bond), an imide group, a carbonylimide group (amide bond), An iminocarbonylimine group (urethane bond), a divalent aliphatic hydrocarbon group which may have a substituent, a divalent aromatic hydrocarbon group which may have a substituent, and a divalent group obtained by combining these. Specific examples of divalent aromatic hydrocarbon groups that may have substituents include: phenylene, 2-methoxy-1,4-phenylene, 3-methoxy-1,4-phenylene , 2-ethoxy-1,4-phenylene, 3-ethoxy-1,4-phenylene, 2,3,5-trimethoxy-1,4-phenylene, etc. Among them, the linking group is preferably an aliphatic hydrocarbon group, and more preferably an alkanediyl group having 1 to 11 carbon atoms which may have a substituent. Furthermore, as the alkanediyl group, methylene, ethylidene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nine Methylene group, decamethylene group, undecamethylene group, etc., these may be linear or branched. Moreover, this alkanediyl group may have a substituent. The substituent is, for example, an alkoxy group having 1 to 4 carbon atoms.

The structure represented by formula (A1') is preferably a photo-alignment polymer in the form of a structural unit represented by formula (A1-1) (hereinafter sometimes referred to as "structural unit (A1-1)'") (A), in one embodiment of the present invention, the photo-alignment polymer (A) includes a structural unit (A1-1). In addition, the structure represented by the formula (A1'') preferably constitutes photoalignment in the form of a structural unit represented by (A1-2) (hereinafter also referred to as "structural unit (A1-2)") Polymer (A), in one embodiment of the present invention, the photo-alignment polymer (A) includes a structural unit (A1-2).

[chemical 4]

In formula (A1-1) and formula (A1-2), L ¹ , L ² , R ¹ , R ² , R ³ , R ⁴ and k are respectively the same as those in formula (A1') or formula (A1'') above L ¹ , L ² , R ¹ , R ² , R ³ , R ⁴ and k are synonymous, SP ¹ is an alkanediyl group with 1 to 11 carbon atoms that may have a substituent, and the structure represented by M ¹ is the formula (M A structure represented by any one of -1) to formula (M-16).

The photo-alignment polymer (A) may have a carboxyl group in addition to a photoreactive group, especially a photoreactive group that undergoes a dimerization reaction. One embodiment of the photo-alignment polymer (A) having a photoreactive group and a carboxyl group can be a polymer comprising a structural unit (A1-1), and another embodiment can be, for example, a polymer comprising the formula (A1') In addition to the structure represented, the structure represented by the formula (A'') or the structural unit (A1-1) and/or the structural unit (A1-2), it also includes the structural unit represented by the formula (A1-3) (hereinafter , also known as "structural unit (A1-3)") and constitute those. [chemical 5]

In formula (A1-3), 1 represents 0 or 1, and SP ² represents an alkanediyl group having 1 to 11 carbon atoms which may have a substituent. The specific example of SP ² is the same as the specific example of SP ¹ in formula (A1-1) and formula (A1-2), and the structure represented by M ² is any of formula (M-1) to formula (M-16). The structure represented by one.

In formula (A1-3), L ³ represents a single bond or -O-, L ⁴ represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH- or -CH ₂ -. R ⁶ and R ⁷ independently represent a hydrogen atom, an alkyl group having 1 to 4 carbons, or an alkoxy group having 1 to 4 carbons. The alkyl group represented by ^R6 and ^R7 may, for example, be methyl, ethyl or butyl, and the alkoxy group may, for example, be methoxy, ethoxy or butoxy.

When the photoalignment polymer (A) is composed of a structural unit (A1-1) or a structural unit (A1-2) and a structural unit (A1-3), it is preferable to combine the structural unit (A1- 1), when the molar fractions of the structural unit (A1-2) and the structural unit (A1-3) relative to all the structural units constituting the photo-alignment polymer (A) are respectively set to p, q and r ( p+r is 1, q+r is 1), satisfying the relationship of 0.10<p or q≦0.90 and 0.10≦r<0.90. In the photo-alignment polymer containing a structural unit (A1-1), this structural unit (A1-1) may be 1 type, and may be 2 or more types. Also, regarding the photo-alignment polymer (A), as long as it does not significantly impair the alignment ability obtained by light irradiation, it may have other than structural units (A1-1), (A1-2) and Structural units (hereinafter, sometimes referred to as "other structural units").

The photoalignment polymer (A) can be derived from the monomer of the structural unit (A1-1) or the structural unit (A1-2), and the derivation of the structural unit (A1-3) and/or other structural units as required Monomers are produced by polymerization (copolymerization). The method of polymerization (copolymerization) may be a conventionally known method in this field. For example, chain polymerization such as radical polymerization, anionic polymerization, and cationic polymerization, and addition polymerization such as coordination polymerization may be used. Polymerization conditions can be appropriately determined according to the type and amount of monomers used, etc., so that a photo-alignment polymer (A) having a desired molecular weight can be obtained.

The weight average molecular weight (Mw) of the photo-alignment polymer (A) is preferably at least 10,000, more preferably at least 15,000, still more preferably at least 20,000, and more preferably at most 1,000,000, more preferably at most 500,000, and even more preferably Below 250,000. When the weight average molecular weight of the photo-alignment polymer (A) is more than the above-mentioned lower limit, it is easy to form a photo-alignment film with good adhesion with the substrate, and if the weight-average molecular weight is below the above-mentioned upper limit, then there is a photo-alignment film. excellent trend. The weight average molecular weight can be adjusted to not less than the above-mentioned lower limit and Below the above upper limit. The weight average molecular weight of the photo-alignment polymer (A) can be measured by gel permeation chromatography (GPC), for example, and can be calculated|required by standard polystyrene conversion.

In the composition for photoalignment film formation, a polymer (A) may be used individually by 1 type, and may use it in combination of 2 or more types.

The content of the photo-alignment polymer in the photo-alignment film-forming composition is the concentration at which the photo-alignment polymer can be completely dissolved in the solvent, and is not particularly limited, relative to the total mass of the photo-alignment film-forming composition , preferably at least 0.1% by mass, more preferably at least 0.5% by mass, and preferably at most 20% by mass, more preferably at most 10% by mass. When the density|concentration of a photo-alignment polymer is more than the said minimum, the obtained alignment film will not become too thin, and the adhesiveness with a board|substrate will tend to improve. Moreover, when the density|concentration of a photoalignment polymer is below the said upper limit, the viscosity of a composition will become low, and there exists a tendency for the thickness of the coating film of this composition to generate|occur|produce unevenness less easily. In addition, when two or more types of photo-alignment polymers are contained in the composition for photo-alignment film formation, the said content means the total amount of content of two or more types of photo-alignment polymers.

[Silane coupling agent] In the present invention, as the silane coupling agent, known compounds in this field can be used. Specifically, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)- 3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- Glycidyloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropane Methyldimethoxysilane, 3-Chloropropyltrimethoxysilane, 3-Methacryloxypropyltrimethoxysilane, 3-Mercaptopropyltrimethoxysilane, 3-Glycidyloxysilane Propyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane base silane, etc.

Also, the silane coupling agent may be a polysiloxane oligomer type silane coupling agent. If polysiloxane oligomers are expressed in the form of (monomer) oligomers, examples include: 3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane Silane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer, etc. Copolymer of mercaptopropyl group; mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane Oxysilane copolymer, mercaptomethyltriethoxysilane-tetraethoxysilane copolymer and other copolymers containing mercaptomethyl groups; 3-glycidyloxypropyltrimethoxysilane-tetramethoxysilane copolymer 3-glycidyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidyloxy Propyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyl methyl Dimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane Ethoxysilane-tetraethoxysilane copolymer and other copolymers containing 3-glycidoxypropyl; 3-methacryloxypropyl trimethoxysilane-tetramethoxysilane copolymer, 3 -Methacryloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methyl Acryloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methyl Acryloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3- Copolymers containing methacryloxypropyl groups such as methacryloxypropyl methyldiethoxysilane-tetraethoxysilane copolymer; 3-acryloxypropyltrimethoxysilane- Tetramethoxysilane copolymer, 3-acryloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropyltriethoxysilane-tetramethoxysilane copolymer , 3-acryloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-propene Acyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-acryloxy Copolymers containing acryloxypropyl such as propylmethyldiethoxysilane-tetraethoxysilane copolymer; vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxy Silane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, Vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer Copolymers containing vinyl, such as vinylmethyldiethoxysilane-tetramethoxysilane copolymer, vinylmethyldiethoxysilane-tetraethoxysilane copolymer; 3-aminopropyl Trimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane Copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl Methyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane Copolymers containing amine groups, such as base silane-tetraethoxysilane copolymer, etc. Silane coupling agents may be used alone or in combination of two or more.

In the present invention, among the above-mentioned silane coupling agents, it is preferably a silane coupling agent having at least one functional group selected from the group consisting of primary amine groups, secondary amine groups, and mercapto groups, more preferably a silane coupling agent having a functional group selected from the primary A silane coupling agent with at least one functional group in the group consisting of amine groups and secondary amine groups. By making the silane coupling agent have at least one functional group selected from the group consisting of the above functional groups, it is easy to form a photo-alignment film with good adhesion to the substrate and has improved liquid stability. A composition for forming a photoalignment film. Furthermore, in order to control the reactivity of a silane coupling agent, the said functional group may suitably have a substituent or a protecting group. Examples of silane coupling agents having protective groups include KBE-9103P (ketimine type) and X-12-1172ES (aldimine type) manufactured by Shin-Etsu Chemical Co., Ltd. as amine-protected types. As a thiol-protected type, X-12-1056ES can be mentioned.

Among the above-mentioned silane coupling agents, 3-aminopropyltriethoxysilane, N-2-(aminoethyl )-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3 - Triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane. Such silane coupling agents can also use commercially available compounds, for example: KBE-903, KBM-602, KBM-603, KBM-903, KBE-9103P, KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.) .

The silane coupling agent is contained at a ratio of 0.5 parts by mass or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass relative to 100 parts by mass of the photoalignment polymer in the composition for forming a photoalignment film. It is not less than 3 parts by mass, more preferably not less than 3 parts by mass, more preferably not more than 30 parts by mass, more preferably not more than 25 parts by mass, still more preferably not more than 14 parts by mass. When the content of the silane coupling agent is more than the above lower limit, it is easy to form a photoalignment film with good adhesion to the substrate and to form a composition for forming a photoalignment film with improved liquid stability. When the content of the silane coupling agent is below the above-mentioned upper limit, the alignment of the alignment film formed from the composition for forming a photo-alignment film is likely to become favorable after storage of the composition for forming a photo-alignment film.

[acid] In the present invention, the composition for forming a photoalignment film contains an acid. The acid is particularly useful for improving the liquid stability of the composition for forming a photoalignment film. In the present invention, the acid may be an organic acid or an inorganic acid. Examples of inorganic acids include: acids derived from hydrogen halides (such as hydrochloric acid, hydrobromic acid, etc.), acids derived from halogen oxyacids (such as hypochlorous acid, chlorous acid, perchloric acid, hypobromous acid, etc.) , bromous acid, perbromic acid, etc.), sulfuric acid, nitric acid, phosphoric acid, hexafluorophosphoric acid, chromic acid, boric acid, etc. Examples of organic acids include glycolic acid, carboxylic acid (acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, etc.), sulfonic acid (methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, etc.) etc.), acrylic acid, methacrylic acid, etc. Acids may be used alone or in combination of two or more.

In a preferred embodiment of the present invention, the acid dissociation constant (pKa) of the acid is preferably 5.0 or less, more preferably 4.5 or less, further preferably 4.0 or less. When the pKa of the acid is below the above-mentioned upper limit, it is easy to form a photoalignment film having good adhesion with a substrate, and it is easy to form a photoalignment film forming composition having improved liquid stability. The lower limit of pKa is not particularly limited, but is preferably not less than -5.0, more preferably not less than -4.0, still more preferably not less than -3.0. When the pKa of an acid is more than the said minimum, it becomes easy to suppress the acid corrosion of a manufacturing facility. The pKa of acids can be obtained from materials such as "Chemical Handbook" (Chemical Society of Japan), for example. When the composition for photoalignment film formation contains 2 or more types of acid, it is preferable that at least 1 type satisfies the said pKa.

In the present invention, the boiling point of the acid is preferably 70°C or higher, more preferably 80°C or higher, further preferably 90°C or higher, and preferably 150°C or lower, more preferably 140°C or lower. If the boiling point of the acid is above the above lower limit, it is easy to form a photoalignment film forming composition with good adhesion to the substrate and has improved liquid stability. If the boiling point of the acid is above the above Below the upper limit, it is easy to reduce the residual amount of acid in the photo-alignment film. The boiling point of acid can be obtained from such materials as "Chemical Handbook" (Chemical Society of Japan). When the composition for photoalignment film formation contains 2 or more types of acid, it is preferable that at least 1 type satisfies the said boiling point.

In terms of being easy to form a photo-alignment film-forming composition with good adhesion to the substrate and having improved liquid stability, suitable specific examples of the acid in the present invention are Preferably, at least one selected from the group consisting of formic acid, toluenesulfonic acid, acrylic acid and acetic acid is included.

In the present invention, the molar ratio of the above-mentioned acid to the above-mentioned silane coupling agent (acid [mole]/silane coupling agent [mole]) is preferably 1 or more, more preferably 2 or more, and more preferably 6 or more, Furthermore, it is more preferably 15 or more, and is more preferably 100 or less, more preferably 60 or less, and still more preferably 50 or less. When the molar ratio of the acid to the silane coupling agent is more than the above lower limit, it is easy to form a photoalignment film with good adhesion to the substrate and a composition for forming a photoalignment film with improved liquid stability. Moreover, the alignment of the alignment film formed from this composition for photoalignment film formation becomes favorable easily. If the molar ratio of the acid to the silane coupling agent is below the above upper limit, the remaining amount of the acid in the photo-alignment film can be easily reduced.

According to the research of the inventors of the present invention, it is found that by adding a specific acid, especially an acid with a specific pKa, to the composition for forming a photo-alignment film comprising a photo-alignment polymer, a silane coupling agent, and a solvent, the previous photo-alignment film The liquid stability of the forming composition is easily further improved. The reason is not clear, but it is presumed that by adding a specific acid, the effect of suppressing the side reaction in the composition from impairing the liquid stability of the composition for forming a photoalignment film increases.

[solvent] In the composition for forming a photoalignment film of the present invention, the solvent is a solvent that can dissolve the components contained in the composition for forming a photoalignment film, and is not particularly limited. Specifically, it can be, for example: water; methanol , ethanol, ethylene glycol, isopropanol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether and other alcohol solvents; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ- Butyrolactone, propylene glycol methyl ether acetate and ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone and other ketone solvents; Aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene Wait. These solvents may be used alone or in combination of two or more.

[other ingredients] In the present invention, the composition for forming a photoalignment film may contain arbitrary components in a range that does not significantly impair the properties of the photoalignment film in addition to the above-mentioned components. Examples of such optional components include polymer materials, photosensitizers, and the like.

By using a polymer material, the solution properties of the composition for forming a photoalignment film can be improved. Such a polymer material may, for example, be polyvinyl alcohol, polyimide, or cellulose derivatives. The polymer material may be used alone or in combination of two or more. The content of the polymer material in the composition for forming a photoalignment film (the total amount when plural types are included) is usually 0.1 to 10 parts by mass, preferably 1 to 10 parts by mass, relative to 100 parts by mass of the photoalignment polymer. 8 parts by mass. When the content of the polymer material is within the above range, a composition with excellent coating properties can be obtained.

等𠮿酮化合物(例如2,4-二乙基9-氧硫𠮿

、2-異丙基9-氧硫𠮿

等)、蒽或具有烷基醚等取代基之蒽化合物(例如二丁氧基蒽等)、啡噻𠯤或紅螢烯。光敏劑可單獨使用1種，亦可組合2種以上使用。The photosensitizer can increase the film strength of the photoalignment film. As a photosensitizer, for example, ketone or 9-oxosulfur

Other ketone compounds (such as 2,4-diethyl 9-oxosulfur

, 2-isopropyl 9-oxosulfur 𠮿

etc.), anthracene or anthracene compounds with substituents such as alkyl ethers (such as dibutoxyanthracene, etc.), phenanthrene or rubrene. The photosensitizer may be used alone or in combination of two or more.

When the composition for forming a photoalignment film contains a photosensitizer, its content (total amount when plural types are included) is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the photoalignment polymer, More preferably, it is 0.3-10 mass parts, More preferably, it is 0.5-8.0 mass parts. If the content of the photosensitizer is within the above range, a composition with enhanced film strength can be obtained.

The composition for photoalignment film formation can be manufactured by the conventionally well-known preparation method, Usually, it can prepare by mixing and stirring the above-mentioned components.

The viscosity of the composition for forming a photoalignment film is preferably 0.1 to 50 mPa･s, more preferably 0.5 to 40 mPa･s, and still more preferably 1 to 30 mPa･s. When the viscosity of the composition for forming a photo-alignment film is within the above-mentioned range, the composition is excellent in handling and coating properties, and it is easy to make the thickness of the obtained photo-alignment film uniform.

[Photoalignment Film] The present invention includes a photoalignment film that is a cured product of the composition for forming a photoalignment film of the present invention, and a laminate including the photoalignment film and a substrate. In the present invention, the photo-alignment film can be obtained, for example, by applying the photo-alignment film-forming composition to the surface of a substrate or the like on which the photo-alignment film is to be formed, drying the solvent, and then irradiating polarized light (preferably polarized light). UV (Ultraviolet, ultraviolet)). In the present invention, the photo-alignment film and the substrate may be laminated via other layers (such as an undercoat layer), but as an aspect of the present invention, the photo-alignment film is preferably adjacent to the substrate.

In the present invention, the substrate preferably has a polar group. Here, in this specification, the term that the base material has a polar group means that the base material has a polar group in the state before the alignment film is formed on the base material. As a polar group, a hydroxyl group, a carboxyl group, an amino group etc. are mentioned, for example. Among them, in terms of the material constituting the base material, or from the viewpoint of the reactivity with the silane coupling agent, which is easily introduced to the surface of the base material by surface modification treatment of the base material, etc. At least one kind of polar group in the group consisting of an amino group, more preferably has a hydroxyl group. By making the substrate before forming the alignment film have the above-mentioned polar group, a bond originating from the reaction of the polar group present in the substrate with silicon contained in the silane coupling agent forming the alignment film is generated, and the substrate and the alignment film are closely bonded. Sex tends to be good. Therefore, in one embodiment of the present invention, there may be a polar group (existing in the substrate) and silicon (in the silane coupling agent) between the substrate and the alignment film constituting the laminated body of the present invention. The Si-O bond of the reaction.

The polar group is preferably present on the surface of the substrate on the side of the laminated alignment film. Such a substrate may be a substrate obtained by using a resin having a polar group such as a vinyl alcohol resin or a cellulose resin as a material, and forming such a substrate into a film, or may be obtained by making a polar group before the precursor group. After the material is formed into a film (precursor film), the precursor group contained in the precursor film is modified into a polar group. Regarding this modification, for example, plasma treatment, laser treatment, ozone treatment, saponification treatment, or flame treatment under vacuum or under atmospheric pressure may, for example, be mentioned. In addition, it may be a substrate with a polymer having a polar group on the surface of a substrate including a material that does not have a polar group or its precursor, or it may be modified to be polar after attaching a polymer with a precursor of a polar group. base material. Furthermore, it may also be obtained by performing graft polymerization by attaching a monomer having a polar group or a polymer having a polar group to the surface of a substrate containing a material having no polar group or its precursor After that, it is reacted by irradiating radiation, plasma, ultraviolet rays, or the like. As a method of attaching a polymer or monomer having a polar group or a precursor of a polar group to the surface of the substrate, for example, a method of applying a solution in which the polymer or monomer is dissolved on the surface of the substrate, etc.

Regarding the above-mentioned substrate, in order to improve the adhesion between the surface of the substrate and the alignment film before or after the above-mentioned modification treatment and the treatment of attaching a polymer or monomer having a polar group or a precursor of a polar group to the surface of the substrate Good, known pretreatment can be performed on the side surface of the laminated alignment film. Such pretreatment may, for example, be corona treatment, plasma treatment, flame treatment or primer treatment. Regarding specific methods and conditions of each treatment, methods and conditions known in the technical field can be appropriately selected according to the intended use or characteristics of the laminate.

The film thickness of the substrate is preferably at least 1 μm, more preferably at least 1.5 μm, more preferably at most 20 μm, more preferably at most 10 μm, and still more preferably at most 5 μm. When the film thickness of the base material is more than the above-mentioned lower limit, processability tends to be excellent, and when the film thickness of the base material is below the above-mentioned upper limit, thinning of the laminate can be easily achieved. The film thickness of a base material can be measured using a laser microscope, a probe contact type film thickness gauge, etc., for example.

In the present invention, the laminate can be obtained, for example, by a method comprising: coating the composition for forming a photoalignment film of the present invention on a substrate; removing the solvent contained in the composition; and removing the The solvent photoalignment film-forming composition was cured.

As a method of applying the composition for forming a photoalignment film on a substrate, a spin coating method, an extrusion coating method, a gravure coating method, a die coating method, a bar coating method, Known methods such as coating methods such as coating methods and printing methods such as flexographic printing methods.

The method of drying and removing the solvent may, for example, be a natural drying method, a ventilation drying method, a heat drying method, or a reduced-pressure drying method. Thereby, a dry coating film is formed. The drying temperature may be, for example, 50 to 200°C, preferably 100°C or higher, more preferably 110°C or higher, further preferably 120°C or higher, and preferably 150°C or lower. If the drying temperature is within the above range, the solvent can be efficiently removed. In addition, the effect of temperature on the photo-alignment film can be suppressed, and the liquid crystal alignment ability exhibited by the photo-alignment film is not easily reduced. The drying time is preferably from 20 seconds to 10 minutes, more preferably from 30 seconds to 5 minutes.

As a method of hardening the composition for photoalignment film formation, polarized light irradiation (preferably polarized light UV irradiation) etc. are mentioned, for example. The photo-alignment film can arbitrarily control the direction of the alignment restriction force by selecting the polarization direction of the irradiated polarized light.

Regarding the method of irradiating polarized light, it may be a form of irradiating polarized light directly to a dry coating film obtained by removing the solvent from the composition for forming a photoalignment film, or irradiating polarized light from the side of the base material on which the dried coating film is formed, A form in which polarized light is transmitted and irradiated. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the irradiated polarized light is preferably within the wavelength range in which the photoreactive group of the polymer forming the photoalignment film can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength of 250 to 400 nm is particularly preferred.

As the light source used for the polarized light irradiation, xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF, ArF, etc. can be cited, and high-pressure mercury lamps, ultra-high pressure mercury lamps, and metal halides are more preferable. lamp. These lamps are preferred due to the greater luminous intensity of ultraviolet light having a wavelength of 313 nm. Polarized light can be irradiated by irradiating light from the above-mentioned light source through an appropriate polarizing element. As the polarizer, polarizers, Glenn-Thompson, Glenn-Taylor and other polarizers and wire-grid polarizers can be used.

In the present invention, the thickness (film thickness) of the photo-alignment film is preferably not less than 10 nm, more preferably not less than 20 nm, and preferably not more than 1000 nm, more preferably not more than 500 nm. When the thickness of the photo-alignment film is more than the above-mentioned lower limit, sufficient alignment-regulating force cannot be obtained, and when the thickness of the photo-alignment film is below the above-mentioned upper limit, thinning can be achieved. The thickness of the photo-alignment film can be measured using, for example, a laser microscope, a probe contact type film thickness gauge, and the like.

The present invention further includes a polarizing element comprising a substrate, the photo-alignment film of the present invention, and a polarizing film.

In the present invention, the polarizing film is not particularly limited. For example, polarized light absorption selection is given by aligning iodine or a dichroic dye to a polyvinyl alcohol (PVA) resin or an aligned liquid crystal. The film of sex.

The iodine PVA polarizing film can be produced, for example, by the following method: the sequential stretching method, in which the PVA in the form of a film is stretched in a heated state, and then dyed with iodine and cross-linked with boric acid; or the simultaneous stretching method, one side is stretched on the Iodine staining in water and cross-linking with boric acid are used to extend the PVA in the form of a film. The elongation ratio at this time is preferably 4 to 8 times, and each molecule is impregnated in the PVA film by successively immersing in an aqueous solution of iodine and an aqueous solution of boric acid. After dyeing, the PVA film is dried to remove moisture, and boric acid crosslinking is performed, whereby a PVA polarizing film can be obtained. Regarding the drying method at this time, it is preferable to carry out by ventilation drying method or infrared drying method, and the temperature is preferably in the range of 40°C to 150°C, more preferably 60°C to 130°C.

A polarizing film in which a dichroic dye is aligned in a liquid crystal can be produced, for example, by mixing a dichroic dye in advance in a layer containing a polymer in an aligned state of a polymerizable liquid crystal compound.

As the polymerizable liquid crystal compound, for example, a compound represented by the following formula (I) (hereinafter sometimes referred to as "compound (I)) etc. may be mentioned. These polymerizable liquid crystal compounds may be used alone or in combination of two types U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ^A -U ² (I) [in formula (I), X ¹ , X ² and ^X3 each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, where the hydrogen atom contained in the divalent aromatic group or a divalent alicyclic hydrocarbon group can be replaced by a halogen atom, a carbon number 1 The carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group is substituted by an alkyl group with 4 to 4, 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 It can be substituted by an oxygen atom or a sulfur atom or a nitrogen atom. Among them, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group that may have a substituent or a cyclohexane- that may have a substituent 1,4-diyl group. Y ¹ , Y ² , W ¹ and W ² are independently a single bond or a divalent linking group. V ¹ and V ² independently represent one of 1 to 20 carbon atoms that may have a substituent Alkanediyl, the -CH ₂ - constituting the alkanediyl can be substituted by -O-, -S- or -NH-. U ¹ and U ² independently represent polymerizable groups or hydrogen atoms, at least one of which is polymerizable sex base]

In the compound (I), at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. In particular, X ¹ and X ³ are preferably cyclohexane-1,4-diyl which may have substituents, and the cyclohexane-1,4-diyl is further preferably trans-cyclohexane-1 ,4-diradical. In the case of a trans-cyclohexane-1,4-diyl structure, smectic liquid crystallinity tends to be easily exhibited. In addition, examples of substituents that may be optionally substituted for 1,4-phenylene or cyclohexane-1,4-diyl that may have substituents include methyl, ethyl, and butyl. C1-4 alkyl groups, cyano groups, chlorine atoms, fluorine atoms and other halogen atoms. Preferably it is unsubstituted.

Y ¹ and Y ² are preferably independently of each other a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a ═CR ^b -, -C≡C- or -CR ^a =N-, R ^a and R ^b independently represent a hydrogen atom or an alkyl group having 1 to 4 carbons. Y ¹ and Y ² are more preferably -CH ₂ CH ₂ -, -COO-, -OCO- or a single bond, more preferably Y ¹ and Y ² are different bonding modes. When Y ¹ and Y ² have different bonding methods, smectic liquid crystallinity tends to be easily expressed.

W ¹ and W ² are preferably a single bond, -O-, -S-, -COO-, or -OCO- independently of each other, more preferably a single bond or -O- independently of each other.

Examples of the alkanediyl group having ¹ to ²⁰ carbon atoms represented by V1 and V2 include methylene, ethylidene, 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, eicosane-1,20-diyl, etc. V ¹ and V ² are preferably an alkanediyl group having 2 to 12 carbons, more preferably a linear alkanediyl group having 6 to 12 carbons. When the alkanediyl group having 6 to 12 carbon atoms is linear, the crystallinity is improved, and the smectic liquid crystallinity tends to be easily expressed. As the optional substituent of the optionally substituted alkanediyl group having 1 to 20 carbon atoms, a cyano group, a chlorine atom, a halogen atom such as a fluorine atom, etc. are mentioned, and the alkanediyl group is preferably unsubstituted, more preferably Preferable is an unsubstituted straight-chain alkanediyl group.

U ¹ and U ² are preferably both polymerizable groups, more preferably both are photopolymerizable groups. A polymerizable liquid crystal compound having a photopolymerizable group is advantageous in that it can be polymerized under lower temperature conditions.

^The polymeric groups represented by U1 and ^U2 may be different from each other, but are preferably the same. Examples of polymerizable groups include: vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxiranyl , Oxetanyl, etc. Among them, acryloxy, methacryloxy, ethyleneoxy, oxiranyl and oxetanyl are preferred, and acryloxy is more preferred.

Specific examples of the polymerizable liquid crystal compound (I) are described in Japanese Patent Application Laid-Open No. 2017-167517, for example, Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or Japanese Patent Manufactured by the known method described in No. 4719156 etc.

The so-called dichroic dye means a dye that has a property in which the absorbance in the long axis direction and the absorbance in the short axis direction of the molecule are different. The dichroic dyes usable in the present invention are not particularly limited as long as they have the above-mentioned properties, and may be dyes or pigments. In addition, two or more dyes or pigments may be used in combination, respectively, or a dye and a pigment may be used in combination. In addition, the dichroic dye may have polymerizability or liquid crystallinity.

In one aspect of the present invention, the dichroic dye preferably has a maximum absorption wavelength (λ _MAX ) in the range of 300-700 nm. As such a dichroic dye, an acridine dye, a cyanine dye, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone dye, etc. are mentioned, for example. Among them, azo pigments are suitable for making polarizing films with excellent polarizing properties due to their high linearity. Therefore, in one aspect of the present invention, the dichroic dye is preferably an azo dye.

Examples of the azo dyes include monoazo dyes, disazo dyes, trisazo dyes, tetrazo dyes, and stilbene azo dyes, and are preferably disazo dyes and trisazo dyes. About such an azo dye, the compound represented by formula (II) is mentioned, for example. K ¹ (-N=NK ² ) _p -N=NK ³ (II) [In the formula (II), K ¹ and K ³ independently represent a phenyl group that may have a substituent, a naphthyl group that may have a substituent, or A valent heterocyclic group which may have a substituent. K ² represents an optionally substituted p-phenylene group, an optionally substituted naphthalene-1,4-diyl group, or an optionally substituted divalent heterocyclic group. p represents an integer of 1-4. When p is an integer of 2 or more, the plurality of K ² may be the same as or different from each other. In the range showing absorption in the visible light range, -N=N-bonds may be replaced by -C=C-, -COO-, -NHCO-, -N=CH-bonds]

In formula (II), as the monovalent heterocyclic group, for example, it can be exemplified from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, benzoxazole, etc. A base formed by removing one hydrogen atom. The divalent heterocyclic group may, for example, be a group obtained by removing two hydrogen atoms from the above heterocyclic compound.

As the phenyl, naphthyl and monovalent heterocyclic group in K1 and K3 in ^formula ( ^II ), and the p ^- phenylene, naphthalene-1,4-diyl and divalent heterocyclic group in K2 The optional substituents include, for example, an alkyl group having 1 to 20 carbons, an alkyl group having 1 to 20 carbons having a polymerizable group, and an alkenyl group having 1 to 4 carbons; methoxy, ethoxy , butoxy and other alkoxy groups with 1 to 20 carbons, alkoxy groups with polymerizable groups with 1 to 20 carbons; fluorinated alkyl groups with 1 to 4 carbons such as trifluoromethyl; cyano; nitro Halogen atom; substituted or unsubstituted amino groups such as amine group, diethylamino group, pyrrolidinyl group (the so-called substituted amino group refers to an alkyl group with 1 or 2 carbon numbers of 1 to 6 amine group, an amine group having one or two polymerizable alkyl groups with 1 to 6 carbon atoms, or two substituted alkyl groups bonded to each other to form an alkanediyl group with 2 to 8 carbon atoms Amino group. The unsubstituted amino group is -NH ₂ ), etc. As said polymeric group, an acryl group, a methacryl group, an acryloxy group, a methacryloxy group etc. are mentioned.

Specific examples of the azo dye represented by formula (II) include, for example, compounds represented by any one of the following formulas (II-1) to (II-8). These azo dyes may be used alone or in combination of two or more.

[式(II-1)～(II-8)中， B ¹～B ³⁰彼此獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烯基、碳數1～4之烷氧基、氰基、硝基、經取代或未經取代之胺基(經取代之胺基及未經取代之胺基之定義如上所述)、氯原子或三氟甲基。 n1～n4彼此獨立地表示0～3之整數。 於n1為2以上之情形時，複數個B ²可彼此相同，亦可不同， 於n2為2以上之情形時，複數個B ⁶可彼此相同，亦可不同， 於n3為2以上之情形時，複數個B ⁹可彼此相同，亦可不同， 於n4為2以上之情形時，複數個B ¹⁴可彼此相同，亦可不同] [chemical 6]

[In the formulas (II-1) to (II-8), B ¹ to B ³⁰ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkenyl group with 1 to 6 carbons, an alkenyl group with 1 to 4 carbons alkoxy, cyano, nitro, substituted or unsubstituted amino (the definitions of substituted and unsubstituted amino are as above), chlorine atom or trifluoromethyl. n1-n4 mutually independently represent the integer of 0-3. When n1 is ² or more, multiple B2s may be the same or different. When n2 is 2 or more, multiple ^B6s may be the same or different. When n3 is 2 or more , the plurality of B ⁹ may be the same or different, and when n4 is 2 or more, the plurality of B ¹⁴ may be the same or different]

In the present invention, the polarizing element can be manufactured by, for example, the following method. A composition containing a polymerizable liquid crystal compound and a dichroic dye (hereinafter also referred to as "polarizing film-forming composition") diluted with a solvent as the case may be is applied onto the alignment film formed on the substrate by the above method. Then, the polymer of the polymerizable liquid crystal compound in an aligned state including a mixture of the polymerizable liquid crystal compound and the dichroic dye can be obtained by performing polymerization after drying the solvent as needed. Polymerize the polymerizable liquid crystal compound while maintaining the state of aligning the polymerizable liquid crystal compound and the dichroic dye in the horizontal direction, thereby obtaining a liquid crystal cured film that maintains the alignment state, the liquid crystal cured film constitutes a polarizing film, and is made of Substrates, alignment films and polarizers for polarizing films. Furthermore, the composition for forming a polarizing film may also contain components such as a solvent, a polymerization initiator, a photosensitizer, a leveling agent, and a reactive additive. Moreover, about the preparation of the composition for polarizing film formation, and its coating method, the method mentioned in the preparation of an alignment film and its coating method can be illustrated similarly.

From the viewpoint of expressing liquid crystallinity, the content of the polymerizable liquid crystal compound in the composition for forming a polarizing film (the total amount when including multiple types) is relative to the solid content of the composition for forming a polarizing film 100 mass A part is usually 60-99 mass parts, Preferably it is 70-95 mass parts, More preferably, it is 75-90 mass parts. In addition, from the viewpoint of obtaining good light absorption properties, the content of the dichroic dye (the total amount when plural types are included) is usually 100 parts by mass of the solid content of the composition for forming a polarizing film. 1 to 30 parts by mass, preferably 2 to 20 parts by mass, more preferably 3 to 15 parts by mass. In addition, the solid content here means the total amount of the component which removed the solvent from the composition for polarizing film formation.

The solvent used for the composition for polarizing film formation can be suitably selected according to the solubility, etc. of the polymerizable liquid crystal compound and dichroic dye to be used. Specifically, the same solvents as those exemplified above as the usable solvent of the composition for forming an alignment film can be mentioned. A solvent may be used individually by 1 type, and may use it in combination of 2 or more types. The content of the solvent is preferably from 100 to 1900 parts by mass, more preferably from 150 to 900 parts by mass, based on 100 parts by mass of the solid content of the composition for forming a polarizing film.

The polymerization initiator used in the composition for forming a polarizing film is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound, and is preferably a photopolymerization initiator in that the polymerization reaction can be initiated at a lower temperature. agent. Specifically, a photopolymerization initiator capable of generating active radicals or acids by the action of light is exemplified, and among them, a photopolymerization initiator capable of generating free radicals by the action of light is preferable. A polymerization initiator can be used individually or in combination of 2 or more types.

系化合物、鹵代苯乙酮系化合物、二烷氧基苯乙酮系化合物、鹵代聯咪唑系化合物、鹵代三𠯤系化合物、三𠯤系化合物等。 產生酸之光聚合起始劑可使用錪鹽及鋶鹽等 As the photopolymerization initiator, known photopolymerization initiators can be used. For example, photopolymerization initiators that generate active radicals include self-cleavage photopolymerization initiators and hydrogen abstraction photopolymerization initiators. Self-cleavage type photopolymerization initiators can use self-cleavage type benzoin-based compounds, acetophenone-based compounds, hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, oxime ester-based compounds, acyl phosphine oxide-based compounds, azo compounds, etc. In addition, as the hydrogen abstraction type photopolymerization initiator, a hydrogen abstraction type benzophenone type compound, a benzoin ether type compound, a benzyl ketal type compound, a dibenzocycloheptanone type compound, an anthraquinone type compound, and a ketone type compound can be used. series compounds, 9-oxosulfur

series compounds, halogenated acetophenone series compounds, dialkoxyacetophenone series compounds, halogenated biimidazole series compounds, halogenated trioxetine series compounds, trioxetine series compounds, etc. Photopolymerization initiators that generate acid can use odonium salts and permeic salts, etc.

Among them, from the viewpoint of preventing the pigment from dissolving, the reaction at low temperature is preferable, and from the viewpoint of the reaction efficiency at low temperature, a self-cleavage type photopolymerization initiator is preferable, and an acetophenone-based compound is particularly preferable. , Hydroxyacetophenone-based compounds, α-aminoacetophenone-based compounds, oxime ester-based compounds.

The content of the polymerization initiator in the composition for forming a polarizing film is preferably from 1 to 10 parts by mass, more preferably from 1 to 8 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound.

As for the photosensitizer used in the composition for forming a polarizing film, the same photosensitizer as exemplified above as the photosensitizer that can be used for the composition for forming an alignment film can be mentioned. The photosensitizer may be used alone or in combination of two or more. The content of the photosensitizer is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 10 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

The leveling agent used in the composition for forming a polarizing film has the function of adjusting the fluidity of the composition for forming a polarizing film and making the coating film obtained by coating the composition for forming a polarizing film more flat. Specifically, A surfactant may, for example, be mentioned. The leveling agent is preferably at least one selected from the group consisting of a leveling agent mainly composed of a polyacrylate compound and a leveling agent mainly composed of a compound containing a fluorine atom. A leveling agent can be used individually or in combination of 2 or more types.

When the composition for forming a polarizing film contains a leveling agent, the content is preferably from 0.05 to 5 parts by mass, more preferably from 0.05 to 3 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound.

The reactive additives used in the composition for forming a polarizing film can generally improve the adhesion of the polarizing film. As a reactive additive, it is preferable to have a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule. Furthermore, the so-called "active hydrogen reactive group" here refers to a group that is reactive to a group having active hydrogen such as carboxyl group (-COOH), hydroxyl group (-OH), amine group (-NH ₂ ), which represents Examples are glycidyl group, oxazoline group, carbodiimide group, aziridine group, imide group, isocyanate group, thioisocyanate group, maleic anhydride group and the like. The number of carbon-carbon unsaturated bonds and active hydrogen reactive groups in the reactive additive is usually 1-20, preferably 1-10.

It is preferable that at least 2 active hydrogen reactive groups exist in the reactive additive, and in this case, the active hydrogen reactive groups present in plural may be the same or different.

The carbon-carbon unsaturated bond of the reactive additive may be a carbon-carbon double bond or a carbon-carbon triple bond, or a combination thereof, but is preferably a carbon-carbon double bond. Among them, regarding the reactive additives, it is preferred that the vinyl and/or (meth)acrylic groups contain carbon-carbon unsaturated bonds. Furthermore, it is preferable that the active hydrogen reactive group is at least one reactive additive selected from the group consisting of epoxy group, glycidyl group and isocyanate group, more preferably has an acrylic group and isocyanate group reactive additives.

Specific examples of reactive additives include: compounds having (meth)acrylic and epoxy groups such as methacryloxyglycidyl ether or acryloxyglycidyl ether; Compounds with (meth)acrylic and oxetanyl groups such as esters or oxetane methacrylates; lactone acrylates or lactone methacrylates with (meth)acrylic and internal Ester-based compounds; compounds with vinyl and oxazoline groups such as vinyl oxazoline or isopropenyl oxazoline; isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-acrylic acid Oligomers of compounds having (meth)acrylic acid groups and isocyanato groups, such as isocyanatoethyl ester and 2-isocyanatoethyl methacrylate, etc. Moreover, the compound etc. which have a vinyl group, a vinylidene group, and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride, are mentioned. Among them, preferred are methacryloxy glycidyl ether, acryloxy glycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate , 2-isocyanatoethyl methacrylate and oligomers of the above compounds, particularly preferably isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate and oligomers of the above compounds.

When the composition for forming a polarizing film contains a reactive additive, the content of the reactive additive is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound.

A polarizing film is formed by polymerizing a liquid crystal substance while maintaining a liquid crystal state. The polymerization method may be appropriately selected from photopolymerization, thermal polymerization, and the like according to the type of polymerizable group. In the case of polymerization by photopolymerization, polymerization can be performed at low temperature and industrial production is easy, so in one aspect of the present invention, photopolymerization is preferable as the polymerization method. In photopolymerization, the light irradiated to the dry coating film may vary depending on the type of the polymerizable liquid crystal compound etc. The kind of the starter and the amount thereof are appropriately selected. Specific examples thereof include one or more active energy rays and active electron beams selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. Among them, ultraviolet light is preferred in terms of the ease of controlling the progress of the polymerization reaction and the fact that the photopolymerization device can be used by a wide range of users in this field, and it is preferable to pre-preferably use a method that can perform photopolymerization by ultraviolet light. The types of the polymerizable liquid crystal compound and the polymerization initiator contained in the composition for forming a polarizing film are selected. In addition, during polymerization, the polymerization temperature can also be controlled by irradiating light while cooling the dried coating film by an appropriate cooling method. During photopolymerization, a patterned polarizing film can also be obtained by performing masking, development, etc.

As the light source of the above-mentioned active energy rays, for example, 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 Emitting Diode) light source with a wavelength range of 380-440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc.

The ultraviolet irradiation intensity is usually 10 to 3,000 mW/cm ² . The intensity of ultraviolet irradiation is preferably an intensity within a wavelength range effective for activation of the polymerization initiator. The time for irradiating light is usually 0.1 second to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and still more preferably 10 seconds to 1 minute. If the ultraviolet radiation is irradiated once or multiple times at such an intensity of ultraviolet radiation, the cumulative light intensity is 10-3,000 mJ/cm ² , preferably 50-2,000 mJ/cm ² , more preferably 100-1,000 mJ/cm ² .

The thickness of the polarizing element including the substrate, the alignment film, and the polarizing film (preferably the polarizing element composed of the substrate, the alignment film, and the polarizing film) can be appropriately determined according to the purpose of the optical laminate incorporating the polarizing element, etc., However, it is preferably at least 1 μm, more preferably at least 2 μm, and more preferably at most 10 μm, more preferably at most 9 μm. If the thickness of the polarizing element is within the above-mentioned range, ultra-thinning can also be easily handled. The thickness of the polarizing element can be measured using an interference film thickness meter, a laser microscope, or a probe contact film thickness meter.

A photoalignment film with desired alignment confining force can be produced from the composition for forming a photoalignment film of the present invention. Therefore, the composition for forming a photoalignment film of the present invention can be used to align various liquid crystal compounds in a desired direction. Therefore, for example, a retardation film obtained by polymerizing a polymerizable liquid crystal compound may be formed on a photoalignment film formed from the composition for forming a photoalignment film of the present invention instead of the polarizing film. [Example]

Hereinafter, although this invention is demonstrated further concretely based on an Example and a comparative example, this invention is not limited to a following example. "%" and "parts" in the examples mean % by mass and parts by mass, respectively, unless otherwise specified.

(1) Preparation of composition for forming photo-alignment film Synthesis example 1: Synthesis of photo-alignment polymer 1 Photo-alignment polymer 1 includes the following structural units. [Photoalignment Polymer 1] [Chemical 7]

[Synthesis scheme of photoalignment polymer 1] [Chem. 8]

[Synthesis of compound (a1-1-1)] 50 g (258 mmol) of ferulic acid were dissolved in 360 g of methanol. 10 g of sulfuric acid was added to the obtained solution at room temperature, and after heating up until the solvent refluxed, it was made to react under reflux for 2 hours. After cooling the obtained reaction solution, 150 g of ice and 150 g of water were added. The supernatant liquid was removed by decantation, and 150 g of 5 degreeC water was added and crystallized. The obtained white crystals were filtered. Furthermore, the white crystal obtained by filtration was washed with 1 M sodium bicarbonate aqueous solution and water, and vacuum-dried to obtain 22.2 g of compound (a1-1-1). The yield was 83% based on ferulic acid.

[Synthesis of compound (b1-1-1)] 25 g (120 mmol) of compound (a1-1-1) was dissolved in 250 g of dimethylacetamide. To the obtained solution were added 33.19 g (240 mmol) of potassium carbonate and 1.99 g (12 mmol) of potassium iodide. 6-Chlorohexanol was added dropwise to the obtained dispersion liquid, stirred at room temperature for 1 hour, and then stirred at 70° C. for 8 hours. The obtained reaction solution was filtered to remove insoluble matter. 200 g of methyl isobutyl ketone and 300 g of water were added to the filtrate, stirred, left still, liquid-separated, and the organic layer was recovered. 200 g of water was added to the recovered organic layer, and the water washing operation of stirring, standing still and liquid separation was repeated twice. The solvent was removed from the recovered organic layer by distillation under reduced pressure using an evaporator to obtain a crude product of compound (b1-1-1).

[Synthesis of compound (c1-1-1)] All the crude product of the above-mentioned compound (b1-1-1) was dissolved in 185 g of ethanol. 92 g of water and 14.41 g (360 mmol) of sodium hydroxide were added to the obtained solution, and stirred at 80° C. for 1 hour. After cooling the reaction solution to about 3°C, the pH was adjusted to 2 by adding 2 M hydrochloric acid aqueous solution while keeping the temperature below 5°C. The white precipitate precipitated by the acid was collected by filtration, washed twice with a mixed solution of 100 g of water and 80 g of methanol, and then vacuum-dried to obtain 30.4 g of compound (c1-1-1). The yield was 86% based on compound (a1-1-1).

[Synthesis of compound (M1-1-1)] 27.46 g (93 mmol) of compound (c1-1-1) were dissolved in 280 g of chloroform. To the obtained solution, 2.06 g of BHT (di-tert-butylhydroxytoluene) and 37.73 g (373 mmol) of triethylamine were added as a polymerization inhibitor, followed by stirring under ice-cooling. 29.26 g (260 mmol) of methacryl chloride was added dropwise to the reaction solution, kept below 5°C, and stirred for 5 hours. 5.7 g of dimethylaminopyridine and 190 g of water were added to the obtained reaction solution, followed by stirring at room temperature for 12 hours. After standing still, the organic layer was recovered, 100 g of 2 N hydrochloric acid aqueous solution was added to the organic layer, and a series of cleaning operations of stirring, standing still, and liquid separation were repeated twice. The organic layer was recovered, 300 g of n-heptane was added, and the precipitated crystals were collected by filtration. After washing twice with a mixed solvent containing 100 g of water and 80 g of methanol, it was vacuum-dried to obtain 22.0 g of compound (M1-1-1). The yield was 65% based on compound (c1-1-1).

[Synthesis of Photoalignment Polymer 1] Add 1.00 g (2.76 mmol) of compound (M1-1-1) and 10 g of tetrahydrofuran to the Schlenk tube, after deoxygenation, while blowing nitrogen gas, add 2.27 mg of azobisisobutyronitrile (AIBN) , stirred at 60°C for 72 hours. The obtained reaction solution was added to 200 g of toluene. The precipitate was collected by filtration, washed with heptane, and vacuum-dried to obtain 0.75 g of photo-alignment polymer 1 . The yield was 75% based on compound (M1-1-1). According to GPC measurement, the molecular weight of the obtained photo-alignment polymer 1 shows that the number average molecular weight is 28200, the weight average molecular weight is about 51300, the Mw/Mn is 1.82, and the monomer content is 0.5%.

光配向性聚合物2 [化10]

光配向性聚合物3 Synthesis Examples 2 and 3: Synthesis of Photo-Alignment Polymer 2 and Photo-Alignment Polymer 3 By the method described in Macromolecules, Vol. 39, No. 26, 9357 (2006), photo-alignment polymers with the following structures were synthesized Sexual polymer 2 and photoalignment polymer 3. Furthermore, the numerical values marked in parentheses in the following structural formulas represent the mole fractions of each structural unit of the photo-alignment polymer 2 and photo-alignment polymer 3 relative to all the structural units. [chemical 9]

Photoalignment Polymer 2 [Chem. 10]

Photoalignment Polymer 3

光配向性聚合物4 Synthesis Example 4: Synthesis of Photo-Alignment Polymer 4 According to the synthesis method of photo-alignment polymer 2 and photo-alignment polymer 3 above, photo-alignment polymer 4 with the following structure was prepared. Furthermore, the numerical values marked in the parentheses in the following structural formula represent the mole fraction of each structural unit of the photo-alignment polymer 4 relative to all structural units. [chemical 11]

photoalignment polymer 4

The weight average molecular weights of the polymers were about 100,000 for the polymer 2, about 90,000 for the polymer 3, and about 95,000 for the polymer 4 in terms of polystyrene.

Mix 2 parts of the above-made photo-alignment polymer (any one of photo-alignment polymers 1 to 4) and 98 parts of o-xylene, and stir the mixture at 80° C. for 1 hour, thereby A polymer solution is obtained. Hereinafter, the polymer solution containing polymer 1, the polymer solution containing polymer 2, the polymer solution containing polymer 3, and the polymer solution containing polymer 4 are referred to as polymer solution 1 and polymer solution 2, respectively. , polymer solution 3 and polymer solution 4.

(2) Production of photoalignment film-forming compositions and laminates Example 1 To the polymer 1 solution, 10 parts by mass of KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by mass of the polymer, and the molar ratio to KBE-903 was 5 [mol/mol ] of formic acid to prepare a composition for forming a photoalignment film.

(3) Production of polarizing film-forming composition The following components were mixed, and it stirred at 80 degreeC for 1 hour, and the composition for polarizing film formation was obtained. Furthermore, the following polymeric liquid crystal compounds and dichroic dyes were prepared by the methods described in the Examples of Japanese Patent Application Laid-Open No. 2013-101328, respectively.

･75 parts of polymerizable liquid crystal compound represented by formula (A-6) [Chem. 12]

･25 parts of polymerizable liquid crystal compound represented by formula (A-7) [Chem. 13]

･2.8 parts of the following dichroic pigment (1) [chemical 14]

･2.8 parts of the following dichroic pigment (2) [Chemical 15]

･2.8 parts of the following dichroic pigment (3) [Chemical 16]

･Polymerization initiator: 6 parts of 2-dimethylamino-2-benzyl-1-(4-𠰌linylphenyl)butan-1-one (Irgacure 369, Ciba Specialty Chemicals Co., Ltd. manufacture) ･Leveling agent: 1.2 parts of polyacrylate compound (BYK-361N, manufactured by BYK-Chemie)

･溶劑：250份之環戊酮 ･Compound B-2: 2 parts of a compound having the following structure (trade name: Laromer (registered trademark) LR-9000; manufactured by BASF Corporation) [Chem. 17]

･Solvent: 250 parts of cyclopentanone

(4) Production of acrylic resin film Based on the description of Japanese Patent Laid-Open No. 2020-56835, an acrylic resin film was produced. 90 parts of multifunctional acrylate monomer (ethylene oxide (12) dipentaerythritol hexaacrylate ("NK ESTER A-DPH-12E" manufactured by Shin Nakamura Chemical Co., Ltd.), 10 parts of amine group Formate acrylate polymer (urethane acrylate ("Ultraviolet UV-3310B" manufactured by Japan Synthetic Chemical Industry Co., Ltd.), 3 parts of free radical polymerization initiator (phenyl bis(2,4 ,6-trimethylbenzoyl)phosphine oxide ("Irgacure 819" manufactured by BASF)) and 10 parts of solvent (methyl ethyl ketone) were mixed and stirred at 50°C for 4 hours to obtain Composition for forming an acrylic resin layer. After performing corona treatment on the release-treated surface of a release-treated polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Corporation) (release film) , the composition for forming an acrylic resin layer was coated by a bar coating method (#2 30 mm/sec), and the exposure amount was 500 mJ using a UV irradiation device (SPOT CURE SP-7, manufactured by Ushio Electric Co., Ltd.). /cm ² (based on 365 nm) ultraviolet rays irradiate the film layer of the resin layer forming composition, thereby obtaining a release film with an acrylic resin layer attached to the resin layer formed on the surface of the release film. The acrylic resin layer The thickness is 1.5 μm.

(5) Production of polarizing element The acrylic resin film as the base material was cut into a square of 10 cm x 10 cm. In order to introduce polar groups to the surface of the base material, a corona treatment device (AGF-B10, Kasuga Electric Co., Ltd. manufacturing), treated once under the conditions of power 0.3 kW and processing speed 3 m/min. The above-mentioned photoalignment film-forming composition was applied to the corona-treated surface using a bar coater, dried at 80° C. for 1 minute, and polarized UV irradiation equipment (SPOT CURE SP-7 with polarizing element unit, Ushio Electric Co., Ltd.), polarized UV exposure was performed with a cumulative light amount of 100 mJ/cm ² to form a photo-alignment film. The thickness of the obtained photo-alignment film was measured using an ellipsometer M-220 (manufactured by JASCO Corporation), and the result was 40 nm.

After applying the composition for forming a polarizing film on the obtained photo-alignment film using a bar coater, it was dried for 1 minute in a drying oven set at 120°C.

Thereafter, using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Electric Co., Ltd.), irradiate (under a nitrogen atmosphere; wavelength: 365 nm; cumulative light intensity at a wavelength of 365 nm: 1000 mJ/cm ² ) ultraviolet rays, borrow In this way, a polarizing film aligned with a polymerizable liquid crystal compound and a dichroic dye is formed, and a laminate (1) comprising a substrate/photoalignment film/polarizing film is obtained. At this time, the thickness of the polarizing element was measured with an ellipsometer, and the result was 2.0 μm.

Embodiment 2-9 A composition for forming a photoalignment film and a laminate were prepared in the same manner as in Example 1 except that the amount of acid added to the composition for forming a photoalignment film was changed to that described in Table 1.

Examples 10-17 Except changing the addition amount of the silane coupling agent in the composition for forming a photoalignment film to that described in Table 1, the composition for forming a photoalignment film and a laminate were prepared in the same manner as in Example 4.

Example 18 A composition for forming a photoalignment film and a laminate were prepared in the same manner as in Example 1 except that p-toluenesulfonic acid was used as the acid, and the molar ratio of the acid to the silane coupling agent was set to 3.

Example 19 A composition for forming a photoalignment film and a laminate were prepared in the same manner as in Example 1 except that acrylic acid was used as the acid, and the molar ratio of the acid to the silane coupling agent was set to 22.

Example 20 Except having used acetic acid as an acid, it carried out similarly to Example 19, and produced the composition for photoalignment film formation, and a laminated body.

Example 21 Except having used the polymer solution 2 instead of the polymer solution 1, it carried out similarly to Example 3, and produced the composition for photoalignment film formation, and a laminated body.

Example 22 Except having used the polymer solution 3 instead of the polymer solution 1, it carried out similarly to Example 3, and produced the composition for photoalignment film formation, and a laminated body.

Example 23 Except having used polymer solution 4 instead of polymer solution 1, it carried out similarly to Example 3, and produced the composition for photoalignment film formation, and a laminated body.

Comparative example 1 Except not adding a silane coupling agent and an acid, it carried out similarly to Example 1, and produced the composition for photoalignment film formation, and a laminated body.

Comparative example 2 Except not adding an acid, it carried out similarly to Example 1, and produced the composition for photoalignment film formation, and a laminated body.

Comparative example 3 Except having used the polymer solution 2 instead of the polymer solution 1, it carried out similarly to the comparative example 2, and produced the composition for photoalignment film formation, and a laminated body.

Comparative example 4 Except having used the polymer solution 3 instead of the polymer solution 1, it carried out similarly to the comparative example 2, and produced the composition for photoalignment film formation, and a laminated body.

Comparative Example 5 Except having used polymer solution 4 instead of polymer solution 1, it carried out similarly to the comparative example 2, and produced the composition for photoalignment film formation, and a laminated body.

(6) Evaluation (6)-1. Liquid stability of composition for forming photoalignment film The liquid stability of the composition for photoalignment films was evaluated as follows. After producing the photoalignment film-forming composition, fill it in a brown bottle, store it statically at 25°C, and pass a predetermined time (1 hour, 2 hours, 3 hours, 1 day, 5 days, and 7 days) from the production Thereafter, the presence or absence of cloudiness and precipitates was visually confirmed, and the liquid stability was evaluated in accordance with the following criteria. 〇: No cloudiness (even if illuminated with light, cloudiness cannot be confirmed) △: Slightly cloudy (white cloudiness can be confirmed when irradiated with light) ×: White turbidity (White turbidity can be confirmed even without irradiating light)

(6)-2. Adhesion between substrate and alignment film Adhesion between the substrate (acrylic resin film) and the photo-alignment film in the obtained laminate was evaluated by the following cross-cut test. (cross cut test) Adhesion between the photoalignment film and the acrylic resin film in the obtained laminate was evaluated by a cross-hatch test ("checkerboard adhesion test" in JIS) based on JIS D0202-1988. On the surface of the acrylic resin film of the 10 cm×10 cm laminated body, draw 10×10 checkerboard-like scratches penetrating through the acrylic resin film and the photo-alignment film every 2 mm to make a checkerboard grid. Make the adhesive tape (25 mm in width, manufactured by Miqibang) fully adhere to the checkerboard surface made by the institute. Then, the adhesive tape was peeled off in the direction of 90° with respect to the surface. The number of grids remaining without peeling was measured, and the adhesiveness was evaluated according to the following criteria. 〇: 50 or more remain. Δ: 10 or more and 49 or less remain. ×: less than 9 pieces. Furthermore, for the peeled checkerboard, it was confirmed by X-ray photoelectron spectroscopy (XPS) that the peeling interface was between the photoalignment film and the substrate.

(6) Whether there is any misalignment after -3.7 days An alignment film was formed from the photo-alignment film-forming composition 7 days after production, and a laminate was produced by the same procedure as above using the alignment film. The obtained laminate of 10 cm×10 cm was mounted on a backlight device, observed visually, and judged by the following criteria. 〇: No misalignment. Δ: Defective alignment was partially generated. ×: Defective alignment occurred on the entire surface.

Table 1 shows the evaluation results of the photo-alignment film-forming compositions and laminates obtained in Examples and Comparative Examples. In Table 1, SC agent represents silane coupling agent, and bp represents boiling point. In addition, the addition amount of a silane coupling agent represents the mass part with respect to 100 mass parts of photoalignment polymers. In the table, "-" in the evaluation results indicates that no evaluation was performed.

[Table 1] photoalignment polymer SC agent acid Adhesion between substrate and photo-alignment film liquid stability With or without malalignment type Amount added (parts by mass) type pKa bp Amount added (acid/SC agent) [mol]/[mol] 1 hour 2 hours 3 hours 1 day 5 days 7 days Comparative example 1 Polymer 1 not added - not added - - - x 〇 〇 〇 〇 〇 〇 〇 Comparative example 2 3-Aminopropyltriethoxysilane (KBE-903) 10.0 not added - - - 〇 x - - - - - - Example 1 formic acid 3.8 101 5 〇 〇 〇 x - - - - Example 2 14 〇 〇 〇 〇 〇 x - - Example 3 19 〇 〇 〇 〇 〇 〇 〇 〇 Example 4 twenty four 〇 〇 〇 〇 〇 〇 〇 〇 Example 5 29 〇 〇 〇 〇 〇 〇 〇 〇 Example 6 34 〇 〇 〇 〇 〇 〇 〇 〇 Example 7 38 〇 〇 〇 〇 〇 〇 〇 〇 Example 8 43 〇 〇 〇 〇 〇 〇 〇 〇 Example 9 48 〇 〇 〇 〇 〇 〇 〇 〇 Example 10 1.0 twenty four △ 〇 〇 〇 〇 〇 〇 〇 Example 11 2.5 twenty four △ 〇 〇 〇 〇 〇 〇 〇 Example 12 5.0 twenty four 〇 〇 〇 〇 〇 〇 〇 〇 Example 13 7.5 twenty four 〇 〇 〇 〇 〇 〇 〇 〇 Example 14 12.5 twenty four 〇 〇 〇 〇 〇 〇 〇 〇 Example 15 15.0 twenty four 〇 〇 〇 〇 〇 〇 〇 △ Example 16 22.5 twenty four 〇 〇 〇 〇 〇 〇 〇 △ Example 17 25.0 twenty four 〇 〇 〇 〇 〇 〇 〇 △ Example 18 10.0 p-Toluenesulfonic acid -2.8 140 3 〇 〇 〇 〇 〇 〇 〇 〇 Example 19 10.0 acrylic acid 4.4 141 twenty two 〇 〇 〇 △ △ x - - Example 20 10.0 Acetic acid 4.8 118 twenty two 〇 〇 〇 △ x - - - Comparative example 3 Polymer 2 10.0 not added - - - 〇 x - - - - - x Example 21 10.0 formic acid 3.8 101 19 〇 〇 〇 〇 〇 〇 〇 〇 Comparative example 4 Polymer 3 10.0 not added - - - 〇 x - - - - - x Example 22 10.0 formic acid 3.8 101 19 〇 〇 〇 〇 〇 〇 〇 〇 Comparative Example 5 Polymer 4 10.0 not added - - - 〇 x - - - - - x Example 23 10.0 formic acid 3.8 101 19 〇 〇 〇 〇 〇 〇 〇 〇

It can be seen that compared with Comparative Example 1 which does not contain a silane coupling agent and no acid, the photo-alignment film formed from the photo-alignment film-forming composition of Examples 1-20 has good adhesion to the substrate. Moreover, it turned out that the liquid stability of the composition for photoalignment film formation of Examples 1-23 was improved compared with Comparative Examples 2-5 which contained a silane coupling agent but did not contain an acid.

Claims (14)

A composition for forming a photo-alignment film, which contains a photo-alignment polymer with a photoreactive group, a silane coupling agent, an acid and a solvent. The composition according to claim 1, wherein the photo-alignment polymer has a photoreactive group that undergoes a dimerization reaction. The composition according to claim 1 or 2, wherein the photo-alignment polymer is a (meth)acrylic polymer. The composition according to any one of claims 1 to 3, wherein the photo-alignment polymer further has a carboxyl group. The composition according to any one of claims 1 to 4, wherein the weight average molecular weight of the photo-alignment polymer is not less than 10,000 and not more than 1,000,000. The composition according to any one of claims 1 to 5, wherein the above-mentioned silane coupling agent has at least one group selected from the group consisting of primary amine groups and secondary amine groups. The composition according to any one of claims 1 to 6, wherein the content of the silane coupling agent is 0.5 to 30 parts by mass relative to 100 parts by mass of the photo-alignment polymer. The composition according to any one of claims 1 to 7, wherein the above-mentioned acid contains at least one selected from the group consisting of formic acid, toluenesulfonic acid, acrylic acid and acetic acid. The composition according to any one of claims 1 to 8, wherein the molar ratio of the above-mentioned acid to the above-mentioned silane coupling agent is not less than 1 and not more than 50. A photo-alignment film formed by hardening the composition according to any one of claims 1 to 9. A laminate comprising a base material and the photo-alignment film according to claim 10. The laminate according to claim 11, wherein the film thickness of the substrate is not less than 1 μm and not more than 20 μm. A polarizing element, comprising a base material, an optical alignment film as claimed in claim 10, and a polarizing film. The polarizing element according to claim 13, which has a thickness of not less than 1 μm and not more than 10 μm.