Compound, composition for photoalignment film, photoalignment film, layered product, and phase difference film

Abstract

Provided are: a compound (C) that can be used in a composition for a photoalignment film; a composition for a photoalignment film; a photoalignment film; a layered product; and a phase difference film. The compound (C) is: a compound (C1) obtained by reacting a polyfunctional epoxy compound having a molecular weight 2000 or less with a cinnamic acid skeleton-containing compound (B); and a compound (C2) represented by formula (3a-1), formula (3a-2), formula (3b-1), formula (3b-2), formula (3c-1), or formula (3c-2). The compound (C) exhibits high solubility in low-invasive solvents and exhibits good characteristics when used in a photoalignment film.

Description

Compound, composition for photo-alignment film, photo-alignment film, laminate, and retardation film

[0001] The present disclosure relates to a compound, a composition for a photo-alignment film, a photo-alignment film, a laminate, and a retardation film.

[0002] In recent years, retardation films (optically anisotropic films) have been used in various forms in the field of displays (liquid crystal displays, organic electroluminescence displays, etc.). Such retardation films are produced by applying a liquid crystalline compound, a dye, a conductive compound, etc. to an alignment film (or substrate) that has liquid crystal alignment ability, followed by alignment. One known alignment method is photoalignment, in which the alignment film is irradiated (exposed) to light such as ultraviolet light to generate an alignment regulating force in the alignment film and / or change the alignment regulating direction of the alignment film. An alignment film used for photoalignment is called a photoalignment film.

[0003] Patent Documents 1 and 2 disclose cured film-forming compositions that can be used as liquid crystal aligning agents for photo-alignment to provide alignment materials that have excellent solvent resistance and can align polymerizable liquid crystals with high sensitivity. More specifically, Patent Document 1 discloses a cured film-forming composition that contains a reaction product of a polymer having an epoxy group and a cinnamic acid derivative having a specific structure, as well as a crosslinking agent. Patent Document 2 also discloses a cured film-forming composition that contains a polymer obtained using a monomer that is the reaction product of a monomer having an epoxy group and a cinnamic acid derivative having a specific structure, as well as a crosslinking agent.

[0004] International Publication No. WO 2018 / 181356 International Publication No. WO 2018 / 181350

[0005] Photo-alignment films are produced by applying a photo-alignment film composition, which is the raw material for the photo-alignment film, to a substrate made of a resin film such as an acrylic film, a TAC (triacetyl cellulose) film, or a COP (cycloolefin polymer) film and then curing the applied composition. In recent years, there has been a demand for using acrylic films as substrates due to their excellent optical properties and reliability, as well as the potential for reduced manufacturing costs. However, the heat resistance and solvent resistance of acrylic films are lower than those of TAC films and COP films, limiting the solvents that can be used in the photo-alignment film composition applied to the acrylic film. In particular, the polymers and reaction products constituting the cured film-forming compositions used as photo-alignment films as disclosed in Patent Documents 1 and 2 have low solubility in solvents with low boiling points that do not attack acrylic films (hereinafter referred to as "low-invasive solvents" or "low-invasive solvents"). Therefore, when applying these cured film-forming compositions to acrylic films, there is a problem in that solvents with high boiling points and a high risk of attacking acrylic films (hereinafter referred to as "high-invasive solvents" or "high-invasive solvents") must be used as solvents. When a cured film-forming composition is applied onto an acrylic film using a highly aggressive solvent, problems such as whitening or wrinkling of the acrylic film occur, making it difficult to produce a photo-alignment film with good properties, and ultimately a retardation film with good properties.

[0006] In view of the above problems, the present disclosure aims to provide a compound that is highly soluble in a minimally invasive solvent and that can exhibit good properties when used in a photo-alignment film, a composition for a photo-alignment film that includes this compound, a photo-alignment film formed from this composition, a laminate that includes this photo-alignment film and an acrylic film, and a retardation film that includes this photo-alignment film.

[0007] The present disclosure provides: [1] a compound (C1) obtained by reacting a polyfunctional epoxy compound (A) having a molecular weight of 2000 or less with a cinnamic acid skeleton-containing compound (B); [2] the compound (C1) according to the above [1], wherein the polyfunctional epoxy compound (A) is represented by the following formula (1a), formula (1b), or formula (1c), and the cinnamic acid skeleton-containing compound (B) is represented by the following formula (2a); Formula (1a): (In the formula, Ra1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, and R a2 are each independently a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and n is an integer of 3 to 10.) Formula (1b): C(X-R b1 ) m (R b2 ) 4-m (1b) (wherein each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R b1 are each independently an epoxy group or a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and R b2 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a hetero atom and at least one hydrogen atom may be substituted, and m is an integer of 2 to 4.) Formula (1c): R c1 -Y-R c2 (1c) (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH2)2) k -O-, or -(O(CH)(CH)(CH)) k -O-, k is an integer of 1 to 5, and R c1 and R c2 are each independently an epoxy group or a hydrocarbon group having 3 to 10 carbon atoms and an epoxy group.) Formula (2a): (In the formula, R 21 is a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, and R 22 is hydrogen, halogen, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure. 21 or R22 [3] Compound (C2) represented by any one of the following formulas (3a-1), (3a-2), (3b-1), (3b-2), (3c-1) and (3c-2): (In the formula, R a1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, each Za is independently a divalent hydrocarbon group having 2 to 12 carbon atoms which may have a carbocyclic ring, the hydroxyl group bonded to Za is bonded to a carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, and R 23 represents hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure, and n is an integer of 3 to 10. (In the formula, R a1 , Za and n are as defined above, the hydroxyl group bonded to Za is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, R 24 represents hydrogen or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted.) Formula (3b-1): (In the formula, each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted; each Zb is independently a divalent hydrocarbon group having 2 to 12 carbon atoms, a hydroxyl group bonded to Zb is bonded to a carbon adjacent to a carbon bonded to a cinnamic acid skeleton by an oxygen atom; R b2 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R 23 is as defined above, and m is an integer of 2 to 4.) Formula (3b-2): (In the formula, X, Zb, Rb2 , R 24 and m are as defined above, and the hydroxyl group bonded to Zb is bonded to a carbon atom adjacent to the carbon atom bonded to the cinnamic acid skeleton via an oxygen atom.) Formula (3c-1): (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH)) k -O-, or -(O(CH)(CH)(CH)) k -O-, k is an integer of 1 to 5, each Zc is independently a divalent hydrocarbon group having 2 to 10 carbon atoms, and the hydroxyl group bonded to Zc is bonded to a carbon atom adjacent to the carbon atom bonded to the cinnamic acid skeleton via an oxygen atom, and R 23 is as above.) Formula (3c-2): (Wherein, Y, Zc and R 24 is as described above, and the hydroxyl group bonded to Zc is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom.) [4] A composition for a photo-alignment film, comprising the compound according to any one of [1] to [3] above; [5] The composition for a photo-alignment film according to [4] above, further comprising a crosslinking agent; [6] A photo-alignment film formed from the composition for a photo-alignment film according to [5] above; [7] A laminate comprising an acrylic film and the photo-alignment film according to [5] above laminated on the acrylic film; and [8] A retardation film further comprising a liquid crystal compound oriented on the photo-alignment film provided in the laminate according to [7] above.

[0008] According to the present disclosure, it is possible to provide a compound that has high solubility in a minimally invasive solvent and that can exhibit good properties when used in a photo-alignment film, a composition for a photo-alignment film that includes this compound, a photo-alignment film formed from this composition for a photo-alignment film, and a retardation film that includes this photo-alignment film.

[0009] Hereinafter, a detailed description will be given of an embodiment of the present invention (hereinafter, simply referred to as an "embodiment"). However, the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0010] In this specification, the terms "(meth)acrylic" and "(meth)acrylate" are general terms for "methacrylic" and "acrylic", "methacrylate" and "acrylate", respectively.

[0011] <Compound (C)> According to a first embodiment of the present disclosure, compound (C) is provided. Compound (C) is a collective term for compounds (C1) and (C2) described below. Compound (C) is a compound that has high solubility in low-invasive solvents and can exhibit good properties when used in a photo-alignment film. Compound (C) is a compound with a relatively low molecular weight (chemical formula weight) that has a hydroxyl group, and has high solubility in low-invasive solvents such as alcohol-based solvents.

[0012] Compound (C1) According to a first aspect of the first embodiment of the present disclosure, compound (C1) is provided. Compound (C1) is a compound obtained by reacting a multifunctional epoxy compound (A) having a molecular weight of 2000 or less with a cinnamic acid skeleton-containing compound (B). The structure of compound (C1) is derived from the multifunctional epoxy compound (A) and the cinnamic acid skeleton-containing compound (B). The specific structure of compound (C1) is typically the same as that of compound (C2) described below, but may differ from that of compound (C2) depending on the types of multifunctional epoxy compound (A) and cinnamic acid skeleton-containing compound (B) used in the production of compound (C1). In other words, compound (C1) represents a broader range of compounds including compound (C2).

[0013] (Multifunctional Epoxy Compound (A)) The multifunctional epoxy compound (A) is a compound having a molecular weight of 2000 or less and two or more epoxy groups. The epoxy groups of the multifunctional epoxy compound (A) react with the hydroxyl groups (including OH groups constituting carboxyl groups) of the cinnamic acid skeleton-containing compound (B), producing a compound (C) having two or more cinnamic acid skeletons per molecule. The molecular weight of the multifunctional epoxy compound (A) indicates the so-called formula weight, and is distinguished from the weight-average molecular weight (Mw) and the number-average molecular weight (Mn). In other words, the multifunctional epoxy compound (A) is not an aggregate of polymers with different degrees of polymerization. However, the multifunctional epoxy compound (A) may be an aggregate of compounds having a common basic structure and different numbers of epoxy groups. In this case, the molecular weight of the multifunctional epoxy compound (A) is an average value according to the proportion of each multifunctional epoxy compound (A) contained therein. From the viewpoint of solubility, the molecular weight of the polyfunctional epoxy compound (A) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less. From the viewpoint of reactivity with the cinnamic acid skeleton-containing compound (B) (hereinafter also simply referred to as "reactivity"), the number of epoxy groups in the polyfunctional epoxy compound (A) is preferably 2 or more and 15 or less, more preferably 2 or more and 10 or less, and even more preferably 2 or more and 8 or less, for example, 3 or more and 8 or less, 6 or more and 8 or less, 3 or more and 6 or less, or 3 or more and 4 or less.

[0014] The polyfunctional epoxy compound (A) is preferably a compound (1a) to (1c) represented by the following formulas (1a) to (1c), from the viewpoints of the solubility of the resulting compound (C1) in a less aggressive solvent (hereinafter, also simply referred to as "solubility") and the reactivity with the cinnamic acid skeleton-containing compound (B).

[0015] [Compound (1a)] (In the formula, R a1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, and R a2 are each independently a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and n is an integer of 3 to 10.

[0016] In the compound (1a), from the viewpoint of reactivity, Ra1 is preferably a linear alkyl group having 1 to 6 carbon atoms, more preferably a linear alkyl group having 1 to 4 carbon atoms, still more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a linear alkyl group having 1 or 2 carbon atoms.

[0017] R in formula (1a) a2 In the formula (I), examples of the hydrocarbon group having 3 to 12 carbon atoms and having an epoxy group include a linear or branched alkyl group having 1 to 6 carbon atoms and having an epoxy group, and a linear or branched alkyl group having 1 to 6 carbon atoms and having an alicyclic epoxy group. Among these, from the viewpoint of reactivity, a linear alkyl group having 1 to 6 carbon atoms and having an epoxy group, and a linear alkyl group having 1 to 6 carbon atoms and having an alicyclic epoxy group are preferred. a2 Preferred examples of the alkyl group include a linear alkyl group having 1 to 4 carbon atoms and having an epoxy group, a linear alkyl group having 1 to 3 carbon atoms and having an epoxy group, a glycidyl group, a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 8 carbon atoms, a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 6 carbon atoms, and a linear alkyl group having 1 to 3 carbon atoms and having an alicyclic epoxy group having 5 to 6 carbon atoms.

[0018] In this specification, the number of carbon atoms in a "hydrocarbon group having 3 to 12 carbon atoms and having an epoxy group" used in describing a "hydrocarbon group" or a "divalent hydrocarbon group" includes all carbon atoms constituting the epoxy group, etc. On the other hand, the number of carbon atoms in a "linear or branched alkyl group having 1 to 6 carbon atoms and having an epoxy group" used in describing an "alkyl group" or an "alkylene group" does not include carbon atoms constituting the epoxy group, etc.

[0019] In this specification, the term "alicyclic epoxy group" refers to an epoxy group formed by bonding one oxygen atom to two adjacent carbon atoms on the ring of an alicyclic hydrocarbon compound.

[0020] In formula (1a), n is preferably 3 to 8, more preferably 3 to 6, and even more preferably 3 to 4, from the viewpoint of coatability (hereinafter also simply referred to as "coatability") of a liquid crystalline compound, a dye, a conductive compound, or the like to be coated onto a photo-alignment film obtained from compound C1.

[0021] In one embodiment, compound (1a) is a compound represented by formula (1a) in which R a1 is a linear alkyl group having 1 to 4 carbon atoms, and R a2 is a linear alkyl group having 1 to 6 carbon atoms and having an epoxy group, or a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 8 carbon atoms, and n is a compound in which n is 3 to 6.

[0022] In another embodiment, compound (1a) is a compound represented by formula (1a) in which R a1 is a linear alkyl group having 1 to 3 carbon atoms, and R a2 is a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 8 carbon atoms, preferably a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 6 carbon atoms, and n is a compound in which n is 3 to 6.

[0023] Specific examples of compound (1a) include 2,4,6,8-tetramethyl-2,4,6,8-tetrakis[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]cyclotetrasiloxane, and the like.

[0024] Commercially available products of compound (1a) include KR-470 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0025] [Compound (1b)] C(X-R b1 ) m (R b2 ) 4-m (1b) (wherein each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R b1 are each independently an epoxy group or a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and R b2are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, and m is an integer of 2 to 4.

[0026] In X of compound (1b), the divalent hydrocarbon group having 1 to 10 carbon atoms, in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, is preferably a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom is substituted with a nitrogen atom, an oxygen atom, or a sulfur atom, from the viewpoints of solubility and reactivity, more preferably an alkylene group having 1 to 10 carbon atoms in which at least one carbon atom is substituted with an oxygen atom, still more preferably an alkylene group having 1 to 6 carbon atoms in which at least one carbon atom is substituted with an oxygen atom, and particularly preferably an alkyleneoxy group having 1 to 4 carbon atoms containing one or more methyleneoxy groups, ethyleneoxy groups, or propyleneoxy groups. When a hydrogen atom is substituted, the substituent can be selected from halogen, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

[0027] R in formula (1b) b1 In the above, examples of the hydrocarbon group having 3 to 12 carbon atoms and having an epoxy group include a linear or branched alkyl group having 1 to 6 carbon atoms and having an epoxy group, and a linear or branched alkyl group having 1 to 6 carbon atoms and having an alicyclic epoxy group. Among these, from the viewpoint of reactivity, R b1 As R, an epoxy group, a linear alkyl group having 1 to 6 carbon atoms and an epoxy group, or a linear alkyl group having 1 to 6 carbon atoms and an alicyclic epoxy group is preferred. b1As examples of the alkyl group, an epoxy group, a linear alkyl group having 1 to 4 carbon atoms and having an epoxy group, a linear alkyl group having 1 to 3 carbon atoms and having an epoxy group, a glycidyl group, a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 8 carbon atoms, a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 6 carbon atoms, a linear alkyl group having 1 to 3 carbon atoms and having an alicyclic epoxy group having 5 to 6 carbon atoms, and the like are preferably used.

[0028] R in formula (1b) b2 In the above, examples of the hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a hetero atom and at least one hydrogen atom may include a linear alkyl group having 1 to 10 carbon atoms, a linear alkoxy group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom may be substituted. Among these, from the viewpoint of reactivity, R b2 The alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 1 to 6 carbon atoms, and even more preferably a linear alkyl group having 1 to 4 carbon atoms. When hydrogen is substituted, the substituent can be selected from halogen, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and the like.

[0029] In formula (1b), m is 2 to 4, but from the viewpoint of reactivity, m is preferably 3 to 4, and more preferably 4.

[0030] In one embodiment, compound (1b) is a compound represented by formula (1b), wherein each X is independently an alkylene group having 1 to 10 carbon atoms in which one carbon atom is substituted with an oxygen atom (O); and R b1 are each independently an epoxy group, a glycidyl group, or a linear alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group having 5 to 8 carbon atoms, and m is 4.

[0031] In another embodiment, compound (1b) is a compound represented by formula (1b), wherein each X is independently an alkylene group having 1 to 10 carbon atoms in which one carbon atom is substituted with an oxygen atom (O), and R b1 are each independently an epoxy group, a glycidyl group, or a linear alkyl group having 1 to 4 carbon atoms and an alicyclic epoxy group having 5 to 8 carbon atoms; R b2 are each independently hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a linear hydroxyalkyl group having 1 to 4 carbon atoms, and m is 2 or 3.

[0032] Specific examples of compound (1b) include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, pentaerythritol tetraglycidyl ether, trimethylolpropane triglycidyl ether, and neopentyl glycol diglycidyl ether.

[0033] Commercially available products of compound (1b) include Denacol EX-212L (manufactured by Nagase ChemteX Corporation), Showfree (registered trademark) PETG (manufactured by Resonac Corporation), Denacol EX-321L (manufactured by Nagase ChemteX Corporation), and other corresponding Denacol (registered trademark) EX series (manufactured by Nagase ChemteX Corporation).

[0034] [Compound (1c)] R c1 -Y-R c2 (1c) (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH2)2) k -O-, or -(O(CH)(CH)(CH)) k -O-, k is an integer of 1 to 5, and R c1 and R c2 are each independently an epoxy group or a hydrocarbon group having an epoxy group and having 3 to 10 carbon atoms.

[0035] In terms of solubility and reactivity, the divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond in Y of formula (1c) is preferably a linear alkylene group having 1 to 9 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms and at least one ester bond, or a phenylene group having two ester bonds (e.g., -O-CO-Ph-CO-O-). k -O-, or -(O(CH)(CH)(CH)) k Also preferred are embodiments in which k is —O— and k is an integer of 1 to 5, an integer of 1 to 3, or 1.

[0036] R in formula (1c) c1 and R c2 In the above, examples of the hydrocarbon group having 3 to 10 carbon atoms and having an epoxy group include a linear or branched alkyl group having 1 to 4 carbon atoms and having an epoxy group, and a linear or branched alkyl group having 1 to 4 carbon atoms and having an alicyclic epoxy group. Among these, from the viewpoint of reactivity, R c1 and R c2 are each independently preferably an epoxy group, a linear alkyl group of 1 to 3 carbon atoms having an epoxy group, or a linear alkyl group of 1 to 2 carbon atoms having an alicyclic epoxy group of 5 to 8 carbon atoms, and more preferably an epoxy group, a glycidyl group, or a linear alkyl group of 1 to 3 carbon atoms having an alicyclic epoxy group of 5 or 6 carbon atoms.

[0037] In one embodiment, compound (1c) is a compound represented by formula (1c), wherein Y is a linear alkylene group having 1 to 3 carbon atoms and having at least one ester bond, and R c1 and R c2 are each independently an epoxy group, a linear alkyl group having 1 to 3 carbon atoms and having an epoxy group, or a linear alkyl group having 1 to 2 carbon atoms and having an alicyclic epoxy group having 5 or 6 carbon atoms.

[0038] In another embodiment, compound (1c) is a compound represented by formula (1c), wherein Y is a phenylene group having two ester bonds, and R c1 and Rc2 are each independently an epoxy group, a linear alkyl group having 1 to 3 carbon atoms and having an epoxy group, or a linear alkyl group having 1 to 2 carbon atoms and having an alicyclic epoxy group having 5 or 6 carbon atoms.

[0039] Specific examples of compound (1c) include phthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and resorcinol glycidyl ether.

[0040] Commercially available products of compound (1c) include Celloxide 2021P (manufactured by Daicel Corporation) and the corresponding Denacol (registered trademark) EX series (manufactured by Nagase ChemteX Corporation).

[0041] (Cinnamic Acid Skeleton-Containing Compound (B)) The cinnamic acid skeleton-containing compound (B) is a compound containing a cinnamic acid skeleton in the molecule. As described above, the hydroxyl group of the cinnamic acid skeleton-containing compound (B) reacts with the epoxy group of the polyfunctional epoxy compound (A), thereby producing a compound (C1) having a cinnamic acid skeleton, and photoalignment properties can be imparted to the compound (C1). The cinnamic acid skeleton refers to a structure represented by the following formula (2a'):

[0042] (In the formula, * represents a bond or a corresponding substituent in each formula described below.)

[0043] The cinnamic acid skeleton-containing compound (B) is not particularly limited as long as it is a compound containing a cinnamic acid skeleton in the molecule. From the viewpoint of providing a photo-alignment film having a high alignment control ability, the cinnamic acid skeleton-containing compound (B) is preferably a compound (2a) represented by the following formula (2a):

[0044] [Compound 2a] (In the formula, R 21 is a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, and R 22is hydrogen, halogen, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure. 21 or R 22 is a hydroxyl group and the other is not a hydroxyl group.)

[0045] In the compound (2a), when the group is not a hydroxyl group, R 21 is preferably an alkoxy group having 1 to 6 carbon atoms.

[0046] In compound (2a), R 22 As described above, when not a hydroxyl group, is hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure. Here, examples of halogen include fluorine, chlorine, bromine, and iodine, with fluorine or chlorine being preferred. Furthermore, when hydrogen is substituted, the substituent can be selected from halogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or the like.

[0047] R in formula (2a) 22 The "alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted" in the above formula may be linear or branched, and is, for example, preferably an unsubstituted linear alkoxy group having 1 to 6 carbon atoms, more preferably an unsubstituted linear alkoxy group having 1 to 4 carbon atoms, and even more preferably an unsubstituted linear alkoxy group having 1 to 3 carbon atoms.

[0048] R in formula (2a) 22Examples of the "hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure" in the above formula include an alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, a cycloalkyl group having 3 to 8 carbon atoms in which at least one hydrogen atom may be substituted, an aromatic hydrocarbon group having 6 to 12 carbon atoms in which at least one hydrogen atom may be substituted, and a hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which has at least one ester bond and at least one cyclic structure. The alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted may be linear or branched. For example, an unsubstituted linear alkyl group having 1 to 6 carbon atoms is preferred, an unsubstituted linear alkyl group having 1 to 4 carbon atoms is more preferred, and an unsubstituted linear alkyl group having 1 to 3 carbon atoms is even more preferred. Furthermore, the cycloalkyl group having 3 to 8 carbon atoms in which at least one hydrogen atom may be substituted is preferably a cyclohexyl group in which at least one hydrogen atom may be substituted. As the aromatic hydrocarbon group having 6 to 12 carbon atoms in which at least one hydrogen atom may be substituted, a phenyl group in which at least one hydrogen atom may be substituted is preferred. As the hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom may be substituted and which has at least one ester bond and at least one cyclic structure, for example, -O-CO-Ph-R 22’ , -CO-O-Ph-R 22’ (In the formula R 22’ is a halogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms).

[0049] Specific examples of compound (2a) include: Among these, 4-methylcinnamic acid, 4-ethylcinnamic acid, 4-methoxycinnamic acid, 4-ethoxycinnamic acid, etc. are preferably used.

[0050] The above-mentioned cinnamic acid skeleton-containing compound (B) can be synthesized by appropriately combining standard methods in organic chemistry.

[0051] (Method for producing compound (C1)) Compound (C1) can be produced by reacting a polyfunctional epoxy compound (A) and a cinnamic acid skeleton-containing compound (B) as raw materials. The reaction is not particularly limited, and typically, compound (C1) can be produced by mixing the polyfunctional epoxy compound (A) and the cinnamic acid skeleton-containing compound (B) in the same vessel and heating the mixture.

[0052] Compound (C2) According to a second aspect of the first embodiment of the present disclosure, there is provided a compound (C2) represented by any one of the above-mentioned formulas (3a-1), (3a-2), (3b-1), (3b-2), (3c-1), and (3c-2). Hereinafter, compound (C2) represented by formula (3a-1) will be referred to as compound (3a-1), and the same applies to those represented by the other formulas.

[0053] (Compound (3a-1)) (In the formula, R a1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, each Za is independently a divalent hydrocarbon group having 2 to 12 carbon atoms which may have a carbocyclic ring, the hydroxyl group bonded to Za is bonded to a carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, and R 23 represents hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure, and n is an integer from 3 to 10.

[0054] In the compound (3a-1), from the viewpoint of reactivity, R a1 is preferably a linear alkyl group having 1 to 6 carbon atoms, more preferably a linear alkyl group having 1 to 4 carbon atoms, still more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a linear alkyl group having 1 or 2 carbon atoms.

[0055] In Za of formula (3a-1), examples of the divalent hydrocarbon group having 2 to 12 carbon atoms and which may have a carbocyclic ring include a linear or branched alkylene group having 1 to 6 carbon atoms and a linear or branched alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms. Of these, from the viewpoint of reactivity, a linear alkylene group having 1 to 6 carbon atoms and a linear alkylene group having 1 to 6 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms are preferred. Furthermore, Za is preferably a linear alkylene group having 1 to 4 carbon atoms, a linear alkylene group having 1 to 3 carbon atoms, a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms, a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, a linear alkylene group having 1 to 3 carbon atoms, a linear alkylene group having 5 to 8 carbon atoms, a linear alkylene group having 5 to 6 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, or a linear alkylene group having 1 to 3 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms.

[0056] In formula (3a-1), n ​​is preferably 3 to 8, more preferably 3 to 6, and even more preferably 3 to 4, from the viewpoint of the coatability (hereinafter simply referred to as "coatability") of a liquid crystalline compound, a dye, a conductive compound, or the like to be applied onto a photo-alignment film obtained from compound C1.

[0057] In compound (3a-1), R 23 As described above, when not a hydroxyl group, is hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure. Here, examples of halogen include fluorine, chlorine, bromine, and iodine, with fluorine or chlorine being preferred. Furthermore, when hydrogen is substituted, the substituent can be selected from halogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or the like.

[0058] R in formula (3a-1) 23The "alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted" in the above formula may be linear or branched, and is, for example, preferably an unsubstituted linear alkoxy group having 1 to 6 carbon atoms, more preferably an unsubstituted linear alkoxy group having 1 to 4 carbon atoms, and even more preferably an unsubstituted linear alkoxy group having 1 to 3 carbon atoms.

[0059] R in formula (3a-1) 23 Examples of the "hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure" in the above formula include an alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, a cycloalkyl group having 3 to 8 carbon atoms in which at least one hydrogen atom may be substituted, an aromatic hydrocarbon group having 6 to 12 carbon atoms in which at least one hydrogen atom may be substituted, and a hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which has at least one ester bond and at least one cyclic structure. The alkyl group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted may be linear or branched. For example, an unsubstituted linear alkyl group having 1 to 6 carbon atoms is preferred, an unsubstituted linear alkyl group having 1 to 4 carbon atoms is more preferred, and an unsubstituted linear alkyl group having 1 to 3 carbon atoms is even more preferred. Furthermore, the cycloalkyl group having 3 to 8 carbon atoms in which at least one hydrogen atom may be substituted is preferably a cyclohexyl group in which at least one hydrogen atom may be substituted. As the aromatic hydrocarbon group having 6 to 12 carbon atoms in which at least one hydrogen atom may be substituted, a phenyl group in which at least one hydrogen atom may be substituted is preferred. As the hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom may be substituted and which has at least one ester bond and at least one cyclic structure, for example, -O-CO-Ph-R 23’ , -CO-O-Ph-R 23’ (In the formula R 22’ is a halogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms).

[0060] (Compound (3a-2)) (In the formula, R a1 , Za and n are as defined above, the hydroxyl group bonded to Za is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, R 24 is hydrogen or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted.

[0061] In compound (3a-2), R a1 The preferred embodiments of R, Za, and n are the same as those described above. 24 are preferably each independently an alkoxy group having 1 to 6 carbon atoms.

[0062] (Compound (3b-1)) (In the formula, each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted; each Zb is independently a divalent hydrocarbon group having 2 to 12 carbon atoms, a hydroxyl group bonded to Zb is bonded to a carbon adjacent to a carbon bonded to a cinnamic acid skeleton by an oxygen atom; R b2 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R 23 is as defined above, and m is an integer of 2 to 4.

[0063] In X of formula (3b-1), the divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted. From the viewpoints of solubility and reactivity, a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom is substituted with a nitrogen atom, oxygen atom, or sulfur atom is preferred, an alkylene group having 1 to 10 carbon atoms in which at least one carbon atom is substituted with an oxygen atom is more preferred, an alkylene group having 1 to 6 carbon atoms in which at least one carbon atom is substituted with an oxygen atom is even more preferred, and an alkyleneoxy group having 1 to 4 carbon atoms containing one or more methyleneoxy groups, ethyleneoxy groups, and propyleneoxy groups is particularly preferred. When a hydrogen atom is substituted, the substituent can be selected from a halogen, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

[0064] In Zb of formula (3b-1), examples of the divalent hydrocarbon group having 2 to 12 carbon atoms include a linear or branched alkylene group having 2 to 6 carbon atoms and a linear or branched alkylene group having 1 to 6 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms. Of these, from the viewpoint of reactivity, a linear alkylene group having 2 to 6 carbon atoms and a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms are preferred. Furthermore, as Zb, a linear alkylene group having 2 to 4 carbon atoms, a linear alkylene group having 2 to 3 carbon atoms, an ethylene group, a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms, a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, a linear alkylene group having 1 to 3 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, and the like are preferably used.

[0065] R in formula (3b-1) b2In the above, examples of the hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a hetero atom and at least one hydrogen atom may include a linear alkyl group having 1 to 10 carbon atoms, a linear alkoxy group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom may be substituted. Among these, from the viewpoint of reactivity, R b2 The alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 1 to 6 carbon atoms, and even more preferably a linear alkyl group having 1 to 4 carbon atoms. When hydrogen is substituted, the substituent can be selected from halogen, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and the like.

[0066] In the compound (3b-1), from the viewpoint of having a high alignment control ability of the resulting photo-alignment film, R 23 are each independently an alkoxy group having 1 to 6 carbon atoms. From the viewpoint of reactivity, m is preferably 2 to 4, more preferably 3 or 4, and even more preferably 4.

[0067] (Compound (3b-2)) (In the formula, X, Zb, R b2 , R 24 and m are as defined above, and the hydroxyl group bonded to Zb is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom.

[0068] In compound (3b-2), X, Zb, R b2 , R 24 The preferred embodiments of and m are the same as those described above.

[0069] (Compound (3c-1)) (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH)) k -O-, or -(O(CH)(CH)(CH)) k-O-, k is an integer of 1 to 5, each Zc is independently a divalent hydrocarbon group having 2 to 10 carbon atoms, and the hydroxyl group bonded to Zc is bonded to a carbon atom adjacent to the carbon atom bonded to the cinnamic acid skeleton via an oxygen atom, and R 23 is as above.)

[0070] In terms of solubility and reactivity, the divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond in Y of formula (3c-1) is preferably a linear alkylene group having 1 to 9 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms and at least one ester bond, or a phenylene group having two ester bonds (e.g., -O-CO-Ph-CO-O-). k -O-, or -(O(CH)(CH)(CH)) k Also preferred are embodiments in which k is —O— and k is an integer of 1 to 5, an integer of 1 to 3, or 1.

[0071] In Zc of formula (3c-1), examples of the divalent hydrocarbon group having 2 to 10 carbon atoms include a linear or branched alkylene group having 2 to 6 carbon atoms and a linear or branched alkylene group having 1 to 2 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms. Of these, from the viewpoint of reactivity, a linear alkylene group having 2 to 4 carbon atoms and a linear alkylene group having 1 to 2 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms are preferred. Furthermore, as Zc, a linear alkylene group having 2 to 4 carbon atoms, a linear alkylene group having 2 to 3 carbon atoms, an ethylene group, a linear alkylene group having 1 to 2 carbon atoms and a carbocyclic ring having 5 to 8 carbon atoms, a linear alkylene group having 1 to 4 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, a linear alkylene group having 1 to 3 carbon atoms and a carbocyclic ring having 5 to 6 carbon atoms, and the like are preferably used.

[0072] In compound (3c-1), R 23 The preferred embodiments of each of the above are the same as those described above.

[0073] (Compound (3c-2)) Formula (3c-2): (Wherein, Y, Zc and R24 is as defined above, and the hydroxyl group bonded to Zc is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton via an oxygen atom.

[0074] In compound (3c-2), Y, Zc, and R 24 The preferred embodiments of each of the above are the same as those described above.

[0075] <Method for producing compound (C2)> The compound (C2) may be produced from any raw material or by any production method, as long as it has a structure corresponding to each of the above formulae, and can be produced by applying known methods in materials and organic chemistry.

[0076] <Composition for photo-alignment film> According to a second embodiment of the present disclosure, there is provided a composition for a photo-alignment film, comprising the compound C of the first embodiment. The amount of the compound C of the first embodiment in the composition for a photo-alignment film is not particularly limited, but from the viewpoint of easily forming a photo-alignment film of a thickness generally used as a photo-alignment film, it is usually preferably about 1 to 80 mass %, more preferably about 5 to about 70 mass %, and even more preferably about 7 to about 70 mass %, relative to the total weight excluding the solvent from the composition for a photo-alignment film (total amount of solids).

[0077] In addition to the compound C, the photo-alignment film composition may optionally contain components typically contained in polymerizable compositions that undergo polymerization by light and heat, such as crosslinkers, resins (polymers), adhesion improvers, catalysts, organic solvents (solvents), photo- and thermal polymerization initiators, and surfactants. The content of these optional components is not particularly limited, but typically, based on the total weight (total solids content) of the photo-alignment film composition excluding the solvent, the crosslinker is preferably contained in an amount of about 1 to about 50% by mass, the resin in an amount of about 1 to about 80% by mass, the adhesion improver in an amount of about 1 to about 10% by mass, the catalyst in an amount of about 1 to about 10% by mass, the photo- and thermal polymerization initiator in an amount of about 1 to about 10% by mass, and the surfactant in an amount of about 0.1 to about 5% by mass. In particular, from the viewpoint of the ability to form a crosslinked structure, the content of the crosslinker is more preferably about 10 to 40% by mass, and even more preferably about 20 to 35% by mass. The amount of solvent contained in the photo-alignment film composition is preferably about 70 to about 99% by mass, based on the total weight of the photo-alignment film composition.

[0078] Crosslinking Agent Any of the crosslinking agents commonly used in this field can be used as a crosslinking agent that can be incorporated into the photo-alignment film composition. Specific examples of such crosslinking agents include methylol compounds, polyfunctional thiol compounds, and polyfunctional (meth)acrylates. Specific examples of these photo-thermal polymerization initiators include those described in International Publication No. 2021 / 2564282. These crosslinking agents may be used alone or in combination of two or more.

[0079] <<Polymer>> The composition for a photo-alignment film according to the present disclosure may contain a polymer. When the composition for a photo-alignment film contains a polymer, it becomes easier to form a photo-alignment film. Polymers that can be incorporated into the composition for a photo-alignment film are not particularly limited, and examples thereof include polymers having a linear or branched structure, such as (meth)acrylic polymers, polyamic acids, polyimides, polyvinyl alcohols, polyesters, polyester polycarboxylic acids, polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyalkyleneimines, polyallylamine, celluloses (cellulose or derivatives thereof), phenol novolac resins, and melamine formaldehyde resins, as well as cyclic polymers such as cyclodextrins.

[0080] Among these polymers, from the viewpoint of high reactivity with a crosslinking agent when a crosslinking agent is contained and easy production of a photo-alignment film with good properties, it is preferable to include acrylic polymers, cyclodextrins, celluloses, polyether polyols, polyester polyols, polycarbonate polyols, and polycaprolactone polyols. Specific examples of these polymers include those described as "component (C)" in the above-mentioned Patent Documents 1 and 2.

[0081] <<Adhesion Improver>> The composition for a photo-alignment film according to the present disclosure may contain an adhesion improver. When the composition for a photo-alignment film contains a monomer, the adhesion between the resulting photo-alignment film and a coating such as a liquid crystalline compound, a dye, or a conductive compound can be improved. The adhesion improver that can be incorporated into the composition for a photo-alignment film is not particularly limited, and examples thereof include a compound having a hydroxy group and a (meth)acrylic group, a compound having an N-alkoxymethyl group and a (meth)acrylic group, and a polymer having an N-alkoxymethyl group and a (meth)acrylic group.

[0082] Among these adhesion improvers, from the viewpoint of reactivity and the fact that they are unlikely to inhibit the alignment control force, preferred examples include polyfunctional acrylates containing hydroxy groups, compounds having one (meth)acrylic group and one or more hydroxy groups, compounds having at least one polymerizable group containing a C═C double bond in the molecule and at least one N-alkoxymethyl group, etc. More specific examples of these adhesion improvers include those described as "adhesion improving components" in the above-mentioned Patent Documents 1 and 2, respectively.

[0083] <<Catalyst>> The composition for a photo-alignment film of the present disclosure may contain a catalyst. When the composition for a photo-alignment film contains a catalyst, the thermal curing reaction during the formation of the photo-alignment film can be accelerated. The catalyst is not particularly limited, but examples thereof include sulfonic acid group-containing compounds, hydrochloric acid or its salts, acids, and thermal acid generators. In particular, compounds that thermally decompose at temperatures of about 80°C to 250°C during pre-baking or post-baking to generate an acid are preferred. Specific examples of catalysts include those described as "crosslinking catalysts" in Patent Documents 1 and 2.

[0084] As the organic solvent that can be blended into the composition for photo-alignment film, any organic solvent commonly used in this field can be used, and examples of such organic solvents include toluene, ethylbenzene, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol methyl ether, dibutyl ether, acetone, methyl ethyl ketone, methanol, ethanol, propanol, 2-propanol, 1-methoxy-2-propanol, cyclohexane, cyclopentanone, methylcyclohexane, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, methoxybutyl acetate, N-methylpyrrolidone, dimethylacetamide, etc. Any of these can be used alone, or two or more can be used in combination.

[0085] As organic solvents that can be incorporated into the composition for photo-alignment films, those with a boiling point of 100°C or less and / or alcohol-based solvents are preferred, from the viewpoint of being less invasive to the acrylic film when an acrylic film is used as the substrate and being able to effectively prevent the acrylic film from whitening or wrinkling. Examples of such organic solvents include acetaldehyde (boiling point: about 21°C), propylene oxide (boiling point: about 33.9°C), diethyl ether (boiling point: about 34.6°C), pentane (boiling point: about 36.1°C), dichloromethane (boiling point: about 39.75°C), carbon disulfide (boiling point: about 46.5°C), acetone (boiling point: about 56°C), methyl acetate (boiling point: about 57°C), chloroform (boiling point: about 61.2°C), methanol (boiling point: about 64.7°C), tetrahydrofuran (boiling point: about 66°C), hexane (boiling point: about 68.74°C), trifluoroacetic acid (boiling point: about 72°C), ethyl acetate (boiling point: about 77°C), ethanol (boiling point: about 78.3°C), absolute ethanol (99.5) (boiling point: about 78.3°C), methyl ethyl ketone (boiling point : about 79.6 ° C), methyl propionate (boiling point: about 80 ° C), benzene (boiling point: about 80.1 ° C), cyclohexane (boiling point: about 80.7 ° C), acetonitrile (boiling point: about 81.6 ° C), 2-propanol (boiling point: about 82.3 ° C), tert-butyl alcohol (boiling point: about 82.4 ° C), 1,2-dichloroethane (boiling point: about 83.5 ° C), 1,2-dimethoxyethane (boiling point: about 85.2 ° C), trichloroethylene (boiling point: about 87.2 ° C), triethylamine (boiling point: about 89.7 ° C), allyl alcohol (boiling point: about 97 ° C), 1-propanol (boiling point: about 97.2 ° C), heptane (boiling point: about 98.4 ° C), ethyl propionate (boiling point: about 99 ° C), 2-butanol (boiling point: about 99.5 ° C), and the like. The content of the preferred solvent in the solvent contained in the composition for a photo-alignment film is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 100% by mass.

[0086] Photo-thermal polymerization initiators that can be incorporated into the photo-alignment film composition include, for example, organic peroxides, α-aminoketone-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzophenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, triazine-based photopolymerization initiators, and other polymerization initiators. Specific examples of these photo-thermal polymerization initiators include those described in WO 2021 / 2564282. These photo-thermal polymerization initiators may be used alone or in combination of two or more.

[0087] <<Surfactant>> As a surfactant that can be blended into the composition for photo-alignment film, any surfactant commonly used to form a film of uniform thickness can be used. Examples of surfactants that can be blended into the composition for photo-alignment film include anionic surfactants, nonionic surfactants, cationic surfactants, alkyl betaines, amphoteric surfactants, and other surfactants. More specific examples of these surfactants include those described in, for example, WO 2021 / 2564282. These surfactants may be used alone or in combination of two or more.

[0088] Other Components In addition, components typically contained in polymerizable compositions that undergo polymerization by light and heat include silane coupling agents, such as alkoxysilane compounds, and polyfunctional compounds including hydrazides, carbodiimides, and acetoacetone.

[0089] The composition for a photo-alignment film of the present disclosure obtained in this manner can be applied to a substrate, and after the solvent is distilled off as necessary, the composition can be irradiated with linearly polarized light to form a photo-alignment film.

[0090] <Photo-Alignment Film> According to a third embodiment of the present disclosure, a photo-alignment film formed from the composition for a photo-alignment film is provided. The photo-alignment film can be produced, for example, by applying the composition for a photo-alignment film to a substrate, distilling off the solvent as necessary, and then irradiating the resulting composition with linearly polarized light. Furthermore, after application to the substrate, the composition for a photo-alignment film may be subjected to a heat treatment such as pre-baking, in which heat is applied to the composition for a photo-alignment film before irradiating with linearly polarized light, or post-baking, in which heat is applied to the composition for a photo-alignment film after irradiating with linearly polarized light. The composition for a photo-alignment film according to the present disclosure can produce a photo-alignment film with excellent properties even at a relatively low temperature for these heat treatments, such as 120°C or less, further 100°C or less, and particularly 90°C or less.

[0091] Examples of substrate materials include glass, resin, and metal. Examples of glass include quartz glass, alkali glass, and alkali-free glass. Examples of resin include acrylic resin, polyimide, polyamide, polyvinyl alcohol, triacetyl cellulose, polyethylene terephthalate, cycloolefin polymer, polyethylene, polycarbonate, polystyrene, and polytrifluorochloroethylene. Examples of metal include iron, aluminum, and copper.

[0092] From the viewpoints of excellent optical properties and reliability, and the possibility of reducing manufacturing costs, it is preferable to use an acrylic film made of acrylic resin as the substrate. Any acrylic film available can be used.

[0093] The composition for a photo-alignment film may be applied by any method generally known in the art, such as spin coating, bar coding, die coating, screen printing, or spray coating.

[0094] The drying step for distilling off the solvent may be carried out by any method commonly used in this field, and is not particularly limited as long as a resin layer film is formed. For example, the drying step may be carried out using a hot air dryer, a hot plate, or a far-infrared heater. The drying step may also serve as a pre-bake step, and the pre-bake step may also serve as a drying step.

[0095] The linearly polarized light can be irradiated onto the photo-alignment film either perpendicularly or obliquely, but is preferably irradiated from the perpendicular direction.

[0096] As used herein, linearly polarized light refers to light in which the plane containing the vibration direction of the electric field (or magnetic field) is specified as a single plane. Linearly polarized light can be obtained by using a polarizing filter or a polarizing prism with light from a light source. The light to be irradiated is not particularly limited, as long as it is an irradiation light capable of imparting photo-alignment ability to the liquid crystal layer to the photo-alignment site upon irradiation, such as infrared light, visible light, ultraviolet light (near ultraviolet light, far ultraviolet light, etc.), X-rays, or charged particle beams (e.g., electron beams, etc.). However, the irradiation light typically has a wavelength of 200 nm to 500 nm, and from the viewpoint of efficiency, near ultraviolet light of 300 nm to 350 nm is preferred. Examples of light sources include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps. The wavelength range of the ultraviolet light or visible light obtained from such light sources may be limited using an interference filter or a color filter.

[0097] The photo-alignment film according to the third embodiment of the present disclosure can impart liquid crystal alignment ability to the alignment film with lower irradiation energy than conventional photo-alignment films. Therefore, the irradiation energy varies depending on the film thickness, but for example, for a thickness of 1 μm, it is usually about 1 mJ / cm 2 ~500 mJ / cm 2 and preferably about 1 to 100 mJ / cm 2 is.

[0098] If a photomask is used when irradiating linearly polarized light, it is possible to generate a patterned alignment ability of liquid crystals or the like in the photo-alignment film in two or more different directions. Specifically, after applying and drying the composition for a photo-alignment film of the present disclosure, a photomask is placed thereon and linearly polarized light is irradiated to impart alignment ability only to the exposed portion, and by changing the direction and repeating this process multiple times as necessary, it is possible to generate a patterned alignment ability in multiple directions.

[0099] The thickness of the photo-alignment film of the present disclosure is preferably in the range of about 10 nm to about 500 nm, more preferably about 100 nm to about 500 nm, and even more preferably about 100 to about 200 nm.

[0100] A retardation material is applied onto the photo-alignment film of the present disclosure obtained in this manner, and then heated to the phase transition temperature of the liquid crystal to turn the retardation material into a liquid crystal state. By photo-curing the liquid crystal, various optically anisotropic films such as a retardation film, a viewing angle improving film, a brightness improving film, and a polarizing film can be obtained.

[0101] <Retardation Film> According to a fourth embodiment of the present disclosure, a retardation film is provided in which a liquid crystalline compound is further aligned on the photo-alignment film. The retardation film is a film having different refractive indices in the X-axis direction and the Y-axis direction, which are perpendicular to the Z-axis direction (film thickness direction), and in which differences occur in the speed of waves vibrating in the X-, Y-, and Z-axis directions when light travels through the film. The retardation film can be obtained by applying a retardation material to the photo-alignment film, heating the material to the phase transition temperature of the liquid crystal to turn the material into a liquid crystal state, and then photo-curing the material.

[0102] The retardation material is not particularly limited as long as it is a polymerizable liquid crystal material, and a material containing a liquid crystal monomer having a polymerizable group, which is commonly used in the technical field, particularly a material containing a polyfunctional monomer having two or more ethylenically unsaturated bonds in one molecule, is preferably used. Such polymerizable liquid crystal materials include those having orientations such as horizontal alignment, cholesteric alignment, vertical alignment, and hybrid alignment, and can be used according to the required retardation. The polymerizable liquid crystal material may be used alone or in combination of two or more types as necessary.

[0103] 《Polyfunctional Monomer》 Examples of polyfunctional monomers having two or more ethylenically unsaturated bonds in one molecule include polyfunctional (meth)acrylate monomers, polyfunctional (meth)acrylamide monomers, polyfunctional vinyl monomers, and polyfunctional allyl monomers. Specific examples of these polyfunctional monomers include those described in WO 2021 / 2564282.

[0104] Other Components The solvent, photopolymerization initiator, crosslinking agent, surfactant, etc. that can be used in the retardation material can be the same as those used in the production of the above-mentioned photo-alignment film composition. In addition, the above-mentioned method for applying the photo-alignment film composition can be used in applying the retardation material.

[0105] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to the following examples.

[0106] The chemicals used in this example are listed below along with their abbreviations. <Multifunctional Epoxy Compounds (A)> a1: Alicyclic epoxy group-containing cyclic siloxane compound (trade name: KR-470, manufactured by Shin-Etsu Chemical Co., Ltd.) a2: 1,3-bis(oxiran-2-ylmethoxy)-2,2-bis[(oxiran-2-ylmethoxy)methyl]propane (PETG) (trade name: Showfree (registered trademark) PETG, manufactured by Resonac Corporation) a3: 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (trade name: Celloxide 2021P, manufactured by Daicel Corporation) a4: 1,6-hexanediol diglycidyl ether (trade name: Denacol EX-212, manufactured by Nagase ChemteX Corporation) a5: Trimethylolpropane triglycidyl ether (trade name: Denacol EX-321, manufactured by Nagase ChemteX Corporation) <Multifunctional Epoxy Polymers (A')> a'1: polymer having an epoxy group (trade name: EHPE3150, manufactured by Daicel Corporation) <Cinnamic acid skeleton-containing compound (B)> b1: 4-methoxycinnamic acid <Crosslinking agent (D)> methoxymethyl-type melamine compound (trade name: Nikalac MW-30, manufactured by Sanwa Chemical Co., Ltd.) <Acrylic monomer> 2-hydroxyethyl methacrylate (2-HEMA) (manufactured by Osaka Organic Chemical Industry Ltd.) <Catalyst (F)> f1: p-toluenesulfonic acid monohydrate (p-TSA) <Solvent (G)> g1: propylene glycol monomethyl ether (PGME) g2: methanol g3: n-propanol g4: i-propanol g5: ethanol

[0107] Synthesis Example 1: Preparation of Acrylic Resin (e1) A four-necked round-bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer was charged with 1,183.0 parts by mass of 2-HEMA, 3,549.2 parts by mass of PGME, and 79.1 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN) as a polymerization initiator. The contents were heated with stirring, and the internal temperature was raised to 60°C to initiate the reaction. The reaction was continued for approximately 7 hours to obtain approximately 4,800 parts by mass of a solution containing p-(2-HEMA) (Mw: 35,000), a homopolymer of 2-HEMA (acrylic resin (e1): (meth)acrylic polymer). PGME was added so that the concentration of the resulting acrylic resin (e1) was 25% by mass, and in the following examples, a 25% by mass PGME solution of this acrylic resin (e1) was used.

[0108] <Production Example 1: Preparation of retardation material> A retardation material having a solid content concentration of 20 mass % was obtained by mixing 7.6 g of polymerizable liquid crystal LC242 (manufactured by BASF Corporation), 0.4 g of Irgacure OXE-01 (manufactured by BASF Corporation) as a polymerization initiator, 0.01 g of BYK-361N (manufactured by BYK Corporation) as a leveling agent, and cyclopentanone as a solvent.

[0109] Example 1 Synthesis of Compound (C) and Solubility Evaluation Example 1-1 30 parts by mass of KR-470, 27.6 parts by mass of 4-methoxycinnamic acid, and 58.7 parts by mass of PGME were charged into a four-necked round-bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer. 1.2 parts by mass of triphenylphosphine was added as a catalyst, and the contents were heated with stirring until the internal temperature was raised to 100°C to initiate the reaction. The reaction was continued for approximately 30 hours, yielding 117 parts by mass of a solution containing compound (C-1) represented by the following formula. PGME was added so that the concentration of the resulting compound (C-1) was 40% by mass, and a 40% by mass PGME solution of compound (C-1) was used in the following examples.

[0110] Examples 1-2 to 1-5, Comparative Example 1-1 Compounds (C-2) to (C-5) according to Examples 1-2 to 1-5, and compound (C'-1) according to Comparative Example 1-1, and their PGME solutions were obtained in the same manner as in Example 1-1, except that the compositions were as shown in Table 1 below. The structures of each compound are shown below.

[0111]

[0112]

[0113] Evaluation of Solubility in Minimally Invasive Solvents The solubility of each compound obtained in Example 1 above in each solvent was measured. The results are shown in Table 1. The solubility of each compound was measured by adding 0.1 g of a 40% by mass PGME solution of each compound dropwise to 10 g of each solvent at room temperature and mixing. The upper limit concentration at which no insoluble matter was visually observed and a homogeneous solution was formed was defined as the solubility of each compound. For example, if no insoluble matter was observed when 0.1 g of each compound was dissolved in a 40% by mass PGME solution, but insoluble matter was observed when 0.2 g of the compound was dissolved, the solubility would be 0.4% by mass. Solubility of 5% by mass or more was evaluated as ○, and solubility of less than 5% by mass was evaluated as ×.

[0114] Example 2: Preparation of Composition for Photo-Alignment Film, Fabrication and Evaluation of Photo-Alignment Film and Retardation Film (120°C) The components were mixed under light shielding according to the formulations shown in Table 2 below to prepare compositions for photo-alignment films according to each Example and Comparative Example. Using these compositions for photo-alignment films, photo-alignment films and retardation films were fabricated at a pre-bake temperature of 120°C, and the following evaluations were performed using the resulting photo-alignment films and retardation films. Details of the fabrication method and each test are shown below, and the results are shown in Table 2. Note that, as shown in the above Example, compound (C'-1) according to Comparative Example 2-1 is difficult to dissolve in a low-invasive solvent. Therefore, in this Example, solvents with high contents of PGME and methanol were also tested, and in order to standardize the evaluation conditions, a TAC film was used as the substrate to which each composition for photo-alignment film was applied.

[0115] (Method for producing a photo-alignment film) Each of the compositions for a photo-alignment film obtained above was applied to a TAC film using a spin coater to a thickness of about 100 nm. After that, it was dried at 120°C for 2 minutes using a hot plate, and then linearly polarized UV light was irradiated at 10 to 40 mJ / cm. 2 The photo-alignment films according to the examples and comparative examples were manufactured by irradiating the substrate with light.

[0116] (Method of Producing Retardation Film) The retardation material obtained in Production Example 1 was applied to the photo-alignment film of each Example and Comparative Example using a spin coater to a thickness of about 1 μm. Then, alignment was performed at 120° C., and unpolarized UV light was then applied at 500 mJ / cm. 2 The retardation films according to the examples and comparative examples were prepared by irradiation.

[0117] (Evaluation) [Appearance of photo-alignment film] The appearance of each photo-alignment film obtained was visually observed and evaluated according to the following criteria: Appearance is colorless and transparent: A Appearance is colored or cloudy: C

[0118] [Appearance when retardation material is applied] The appearance of each retardation film obtained was visually observed and evaluated according to the following criteria: Appearance is colorless and transparent: A Appearance is colored or cloudy: C

[0119] [Visual Inspection Under Crossed Nicols] Each of the obtained retardation films was observed under a polarizing microscope (device name: BX53, manufactured by Olympus Corporation) equipped with two orthogonal polarizing plates, and evaluated according to the following criteria: No light leakage: A Slight spot light leakage: B Light leakage: C

[0120]

[0121] Example 3 Preparation of Composition for Photo-Alignment Film, Fabrication and Evaluation of Photo-Alignment Film and Retardation Film (90° C.) A composition for an alignment film was prepared, and a photo-alignment film and a retardation film were fabricated and evaluated according to the compositions shown in Table 3 below, in the same manner as in Example 2, except that the pre-bake temperature was set to 90° C. The results are shown in Table 3.

[0122]

Claims

1. A compound (C1) obtained by reacting a polyfunctional epoxy compound (A) having a molecular weight of 2000 or less with a compound (B) containing a cinnamic acid skeleton.

2. Compound (C1) according to claim 1, wherein the polyfunctional epoxy compound (A) is represented by the following formula (1a), formula (1b), or formula (1c), and the cinnamic acid skeleton-containing compound (B) is represented by the following formula (2a): Formula (1a): (In the formula, R a1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, and R a2 are each independently a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and n is an integer of 3 to 10.) Formula (1b): C(X-R b1 ) m (R b2 ) 4-m (1b) (wherein each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R b1 are each independently an epoxy group or a hydrocarbon group having 3 to 12 carbon atoms and an epoxy group, and R b2 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a hetero atom and at least one hydrogen atom may be substituted, and m is an integer of 2 to 4.) Formula (1c): R c1 -Y-R c2 (1c) (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH2)2) k -O-, or -(O(CH)(CH)(CH)) k -O-, k is an integer of 1 to 5, and R c1 and R c2 are each independently an epoxy group or a hydrocarbon group having 3 to 10 carbon atoms and an epoxy group.) Formula (2a): (In the formula, R 21 is a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, and R 22 is hydrogen, halogen, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure. 21 or R 22 is a hydroxyl group and the other is not a hydroxyl group.) 3. A compound (C2) represented by any one of the following formulas (3a-1), (3a-2), (3b-1), (3b-2), (3c-1) and (3c-2): Formula (3a-1): (In the formula, R a1 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, each Za is independently a divalent hydrocarbon group having 2 to 12 carbon atoms which may have a carbocyclic ring, the hydroxyl group bonded to Za is bonded to a carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, and R 23 represents hydrogen, halogen, an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted, or a hydrocarbon group having 2 to 20 carbon atoms in which at least one hydrogen atom may be substituted, which may have at least one ester bond, and which may have at least one cyclic structure, and n is an integer of 3 to 10. (In the formula, R a1 , Za and n are as defined above, the hydroxyl group bonded to Za is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton by an oxygen atom, R 24 represents hydrogen or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom may be substituted.) Formula (3b-1): (In the formula, each X is independently a divalent hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted; each Zb is independently a divalent hydrocarbon group having 2 to 12 carbon atoms, a hydroxyl group bonded to Zb is bonded to a carbon adjacent to a carbon bonded to a cinnamic acid skeleton by an oxygen atom; R b2 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms in which at least one carbon atom may be substituted with a heteroatom and at least one hydrogen atom may be substituted, R 23 is as defined above, and m is an integer of 2 to 4.) Formula (3b-2): (In the formula, X, Zb, R b2 , R 24 and m are as defined above, and the hydroxyl group bonded to Zb is bonded to a carbon atom adjacent to the carbon atom bonded to the cinnamic acid skeleton via an oxygen atom.) Formula (3c-1): (wherein Y is a divalent hydrocarbon group having 2 to 10 carbon atoms and at least one ester bond, -O-Ph-O-, -(O(CH)) k -O-, or -(O(CH)(CH)(CH)) k -O-, k is an integer of 1 to 5, each Zc is independently a divalent hydrocarbon group having 2 to 10 carbon atoms, and the hydroxyl group bonded to Zc is bonded to a carbon atom adjacent to the carbon atom bonded to the cinnamic acid skeleton via an oxygen atom, and R 23 is as above.) Formula (3c-2): (Wherein, Y, Zc and R 24 is as defined above, and the hydroxyl group bonded to Zc is bonded to the carbon adjacent to the carbon bonded to the cinnamic acid skeleton via an oxygen atom.

4. A composition for a photo-alignment film, comprising the compound according to claim 1 or 3.

5. The composition for a photo-alignment film according to claim 4, further comprising a crosslinking agent.

6. A photo-alignment film formed from the composition for a photo-alignment film according to claim 5.

7. A laminate comprising an acrylic film and the photo-alignment film according to claim 5 laminated on the acrylic film.

8. A retardation film in which a liquid crystal compound is further aligned on the photo-alignment film provided in the laminate according to claim 7.

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