Alignment film forming material, alignment film, and polymer dispersed liquid crystal element

Abstract

To provide an alignment layer forming material giving an alignment layer having high light transmittance in a transmissive state and high adhesion between a polymer liquid crystal layer and a substrate.SOLUTION: A compound represented by the following formula (C2) or (C3): SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an alignment film forming material, an alignment film, and a polymer dispersed liquid crystal element. [Background technology]

[0002] Polymer dispersed liquid crystal elements do not require polarizing plates, and therefore have the advantage of being able to achieve brighter displays than TN, STN, IPS or VA mode liquid crystal display elements that use conventional polarizing plates. As the element structure is also simple, they are used in optical shutter applications such as light control glass and segment displays such as in watches.

[0003] There are several types of polymer dispersed liquid crystal elements, and for example, a type called NCAP (Nematic Curvilinear Aligned Phase) (Patent Document 1), a type called PDLC (Polymer Dispersed Liquid Crystal) (Patent Document 2, Patent Document 3), a type called PNLC (Polymer Network Liquid Crystal) (Patent Document 4), and a polymer stabilized cholesteric liquid crystal (PSCT: Polymer Stabilized Cholesteric Texture) using cholesteric liquid crystal have been proposed.

[0004] Among these, liquid crystal elements using PDLC or PNLC have been actively studied. Known examples include normal mode polymer dispersed liquid crystal elements (Patent Document 5), in which the liquid crystals orient in random directions when no voltage is applied and become cloudy (light scattering), and when voltage is applied, the liquid crystals align in the direction of the electric field, allowing light to pass through and becoming transparent, and reverse mode polymer dispersed liquid crystal elements (Patent Document 6), in which the liquid crystals are in a transparent state when no voltage is applied and become scattering when voltage is applied. For light-control applications, light-control elements are being considered that include a structure in which a polymer liquid crystal layer in which liquid crystal molecules are encapsulated in a polymer is used as a light-control layer, and the light-control layer is sandwiched on both sides between a pair of glass substrates or plastic substrates on which transparent electrodes made of transparent conductive films are formed, and in some cases an alignment film that aligns the liquid crystal molecules is formed on the surface of the transparent electrodes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 58-501631 [Patent Document 2] Japanese Patent Application Publication No. 2-15236 [Patent Document 3] Japanese Patent Application Publication No. 63-271233 [Patent Document 4] Japanese Patent Application Publication No. Hei 1-198725 [Patent Document 5] International Publication No. 2020 / 184420 [Patent Document 6] International Publication No. 2014 / 133154 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, due to the high light transmittance of the light control element using the polymer liquid crystal layer, its application to light control windows such as sunroofs for automobiles, show windows that can display letters and patterns, and smart windows that are expected to have an infrared blocking effect has been considered. In applications such as those mentioned above, it is necessary to block the view in the light scattering state while ensuring sufficient visibility in the transparent state. Therefore, light-control devices using PDLC or PNLC are required to improve the light transmittance in the transparent state as much as possible more than ever before. Furthermore, if the adhesion between the polymer liquid crystal layer and the substrate in a dimming element is low, the light scattering properties may change over time, and the function of blocking the field of view may be lost. Therefore, an alignment film that has high adhesion between the polymer liquid crystal layer and the substrate is required.

[0007] The present invention has been made to solve the above-mentioned problems, and provides an alignment film forming material that provides an alignment film having high light transmittance in a transmitted state and high adhesion between a polymer liquid crystal layer and a substrate, an alignment film, and a polymer dispersed liquid crystal element equipped with the alignment film. [Means for solving the problem]

[0008] As a result of intensive research conducted by the present inventors to achieve the above object, they discovered that an alignment film-forming material having the following composition is effective in achieving the above object, and thus completed the present invention.

[0009] The present invention is summarized as follows. An alignment film-forming material comprising the following components (A) and (B): Component (A): A polymer component (A) having a carboxy group and a structure represented by the following formula (S), wherein the polymer constituting the polymer component (A) is at least one polymer (A) selected from the group consisting of polyimide precursors, polyimides which are imidized products thereof, and polymers of monomers having polymerizable unsaturated bonds. Component (B): A compound (B) having a molecular weight of 2000 or less, which has in its molecule at least one epoxy group and one group having a polymerizable unsaturated bond, and the epoxy group and the group having a polymerizable unsaturated bond are linked via a divalent organic group having an alkylene group having 4 to 20 carbon atoms. [ka] (X is a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 - (a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1s and A1s each independently have the above definition). J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups having 4 to 40 carbon atoms and aromatic hydrocarbon groups having 6 to 40 carbon atoms, provided that at least one hydrogen atom possessed by the alicyclic hydrocarbon group and aromatic hydrocarbon group is substituted with a substituent selected from the group consisting of a halogen atom, a halogen-atom-containing alkyl group, a halogen-atom-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, and a heteroatom-containing group in which a carbon-carbon bond possessed by any methylene group of the halogen-atom-containing alkyl group, halogen-atom-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted by an oxygen atom. * represents a bond. [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain an alignment film forming material that provides an alignment film having high light transmittance in a transmitted state and high adhesion between a polymer liquid crystal layer and a substrate, an alignment film, and a polymer dispersed liquid crystal element having the alignment film. The mechanism by which the above-described effects of the present invention are obtained is not entirely clear, but the following is thought to be one of the reasons. The alignment film-forming material of the present invention exhibits high adhesion due to the progression of crosslinking between the carboxyl groups of the polymer component (A) and the epoxy groups of the compound (B), as well as the progression of crosslinking between the polymerizable unsaturated bonds of the compound (B) and the polymer liquid crystal layer. By increasing the number of carbon atoms in the alkylene of the compound (B) to 4 or more, hydrophobicity is enhanced, making it easier for the polymerizable unsaturated bond sites to be present at the alignment film interface, resulting in higher adhesion. Furthermore, because the number of polymerizable unsaturated bonds in the compound (B) molecule is small, the alignment film maintains high liquid crystal alignment, resulting in high transmittance in the transmission state. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing an example of a liquid crystal element of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The alignment film forming material, alignment film, and polymer dispersed liquid crystal element having the alignment film of the present invention will be described in detail below. However, the description of the constituent elements described below is an example of one embodiment of the present invention, and the present invention is not limited to these contents. In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0013] <Polymer component (A)> The alignment film-forming material of the present invention contains the following component (A) (polymer component (A)). Component (A): Polymer component (A) having a carboxy group and a structure represented by the above formula (S), provided that the polymer constituting the polymer component (A) is at least one polymer (A) selected from the group consisting of polyimide precursors, polyimides which are imidized products thereof, and polymers of monomers having polymerizable unsaturated bonds. The polymer component means a component made of a polymer, and may be made of one type of polymer or multiple types of polymers. The polymer (A) may be one type or two or more types.

[0014] The polymer component (A) is preferably (i) It contains at least one polymer (A-1) selected from the group consisting of polyimide precursors having a carboxy group and a structure represented by the above formula (S) in the same molecule, polyimides that are imidized therefrom, and polymers of monomers having polymerizable unsaturated bonds, or (ii) it contains at least one polymer (A-2) selected from the group consisting of polyimide precursors having a carboxy group, polyimides that are imidized therefrom, and polymers of monomers having polymerizable unsaturated bonds, and at least one polymer (A-3) selected from the group consisting of polyimide precursors having a structure represented by the above formula (S), polyimides that are imidized therefrom, and polymers of monomers having polymerizable unsaturated bonds. The polymer component (A) may consist of the polymer (A-1), or may consist of the polymer (A-2) and the polymer (A-3). It should be noted that all of the polymers (A-1) to (A-3) are included in the scope of the polymer (A).

[0015] The mode of containing the polymer (A) in the alignment film-forming material can be appropriately selected depending on the application and environment of use, but preferred examples for more suitably achieving the effects of the present invention include the following modes [a] to [c]. [a] An embodiment in which the polymer (A) is at least one selected from the group consisting of polyimide precursors and polyimides that are imidized products thereof. [b] An embodiment in which the polymer (A) contains at least one selected from the group consisting of polyimide precursors and polyimides, which are imidized products thereof, and a polymer of a monomer having a polymerizable unsaturated bond. [c] An embodiment in which the polymer (A) is a polymer of a monomer having a polymerizable unsaturated bond. Of these, from the viewpoint of more suitably obtaining the effects of the present invention, the embodiments [a] and [c] are preferred. In the case of the above [b], the total content of the polyimide precursor and its imidized product, that is, the polyimide, is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on the total amount of the polymer (A) contained in the alignment film-forming material. The upper limit of this content is preferably 99% by mass or less, and even more preferably 97% by mass or less.

[0016] In order to more suitably achieve the effects of the present invention, preferred examples of the polymer component (A) include the following embodiments [a1] to [c2]. [a1] An embodiment containing at least one polymer selected from the group consisting of polyimide precursors having a carboxy group and a structure represented by the above formula (S) in the same molecule, and polyimides which are imidized products thereof. [a2] An embodiment containing at least one polymer selected from the group consisting of polyimide precursors having a carboxy group and polyimides that are imidized products thereof, and at least one polymer selected from the group consisting of polyimide precursors having a structure represented by the above formula (S) and polyimides that are imidized products thereof. [b1] An embodiment containing at least one polymer selected from the group consisting of polyimide precursors having a carboxy group and polyimides that are imidized products thereof, and a polymer of a monomer having a polymerizable unsaturated bond and having a structure represented by the above formula (S). [b2] An embodiment containing at least one polymer selected from the group consisting of polyimide precursors having a structure represented by the above formula (S) and polyimides that are imidized products thereof, and a polymer of a monomer having a polymerizable unsaturated bond with a carboxy group. [c1] An embodiment containing a polymer of a monomer having a polymerizable unsaturated bond, which has a carboxy group and a structure represented by the above formula (S) in the same molecule. [c2] An embodiment containing a polymer of a monomer having a polymerizable unsaturated bond with a carboxy group, and a polymer of a monomer having a polymerizable unsaturated bond having a structure represented by the above formula (S).

[0017] Of these, from the viewpoint of more suitably obtaining the effects of the present invention, the embodiment [a1] or [c1] is preferred. In the case of [a1], the total of the repeating units having a carboxy group and the repeating units having the structure represented by formula (S) is preferably 10 mol % or more of the repeating units constituting the polyimide precursor and its imidized product, the polyimide. The content of the repeating units having the structure represented by formula (S) is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, of the repeating units constituting the polyimide precursor and its imidized product, the polyimide. In the case of [c1] above, the total of the monomer having a carboxy group and a polymerizable unsaturated bond and the monomer having a structure represented by formula (S) and a polymerizable unsaturated bond is preferably 10 mol % or more of the monomer component having a polymerizable unsaturated bond used in synthesizing the polymer. Furthermore, when a monomer having a polymerizable unsaturated bond other than the monomer having a carboxy group and a polymerizable unsaturated bond and the monomer having a structure represented by formula (S) and a polymerizable unsaturated bond is used, the total of the monomer having a carboxy group and a polymerizable unsaturated bond and the monomer having a structure represented by formula (S) and a polymerizable unsaturated bond is preferably 99 mol % or less, more preferably 95 mol % or less, and even more preferably 90 mol % or less.

[0018] Examples of the alicyclic hydrocarbon group having 4 to 40 carbon atoms in the formula (S) include monocyclic alicyclic hydrocarbon groups such as cyclobutane, cyclopentane, cyclohexane, and cyclodecane; and fused polycyclic alicyclic hydrocarbon groups formed by condensing two or more monocyclic alicyclic hydrocarbon groups, such as norbornene, adamantane, and a steroid skeleton. The steroid skeleton has a cyclopentano-perhydrophenanthrene nucleus as its basic skeleton, and the alicyclic ring of the nucleus may have a double bond or a substituent. Examples of the substituent possessed by the alicyclic hydrocarbon group include a halogen atom, a halogen-containing alkyl group, a halogen-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, and a heteroatom-containing group in which a carbon-carbon bond of any methylene group in the halogen-containing alkyl group, halogen-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted by an oxygen atom. However, the alicyclic hydrocarbon group may have a substituent other than these substituents. The halogen atom is preferably a fluorine atom, and the fluorine atom-containing alkyl group is preferably a trifluoromethyl group.

[0019] Examples of the aromatic hydrocarbon group having 6 to 40 carbon atoms in the formula (S) include monocyclic aromatic hydrocarbon groups such as benzene; and fused polycyclic aromatic hydrocarbon groups formed by condensing two or more monocyclic aromatic hydrocarbon groups, such as naphthalene and anthracene. Examples of substituents on the aromatic hydrocarbon group include halogen atoms, halogen-containing alkyl groups, halogen-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, alkenyl groups having 3 to 10 carbon atoms, and heteroatom-containing groups in which a carbon-carbon bond in any methylene group of the halogen-containing alkyl groups, halogen-containing alkoxy groups, alkyl groups, alkoxy groups, and alkenyl groups is interrupted by an oxygen atom. However, the aromatic hydrocarbon group may also have a substituent other than these. The halogen atom is preferably a fluorine atom, and the fluorine-containing alkyl group is preferably a trifluoromethyl group.

[0020] When the formula (S) is a monovalent organic group having two or more groups of at least one type selected from the group consisting of alicyclic hydrocarbon groups having 4 to 40 carbon atoms and aromatic hydrocarbon groups having 6 to 40 carbon atoms, it is sufficient that at least one of the alicyclic hydrocarbon groups or aromatic hydrocarbon groups has a substituent exemplified above (i.e., a substituent selected from the group consisting of a halogen atom, a halogen-atom-containing alkyl group, a halogen-atom-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, and a heteroatom-containing group in which a carbon-carbon bond of any methylene group in the halogen-atom-containing alkyl group, halogen-atom-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted by an oxygen atom), and the other alicyclic hydrocarbon groups or aromatic hydrocarbon groups in the formula (S) may be unsubstituted or may have a substituent other than the above-exemplified substituents.

[0021] More preferred specific examples of the structure represented by the above formula (S) include structures represented by any of the following formulas (S1) to (S2). [ka] (X1 is a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 - (a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1s and A1s each independently have the above definition). G 1 represents a divalent cyclic group selected from divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms and divalent alicyclic hydrocarbon groups having 4 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine atom-containing alkyl group having 1 to 3 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. m is an integer of 1 to 4. When m is 2 or more, a plurality of X 1 , G 1 are each independently defined above. R 1 represents a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms. [ka] (X 2 represents -CONH-, -NHCO-, -O-, -CHO-, -OCH-, -COO- or -OCO-. 2represents a structure having a steroid skeleton, wherein at least one hydrogen atom of the structure having a steroid skeleton is substituted with a substituent selected from the group consisting of a halogen atom, a halogen-atom-containing alkyl group, a halogen-atom-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, and a heteroatom-containing group in which a carbon-carbon bond of any methylene group of the halogen-atom-containing alkyl group, halogen-atom-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted with an oxygen atom.

[0022] In the above formula (S1), G 1 Examples of the divalent cyclic group in the formula (I) include a cyclopropylene group, a cyclohexylene group, and a phenylene group. Any hydrogen atom on these cyclic groups may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine atom-containing alkyl group having 1 to 3 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.

[0023] In the above formula (S2), G 2 Examples of the structure having a steroid skeleton in the formula (I) include a structure containing a cholestanyl group, a cholesteryl group, or a lanostaniyl group.

[0024] Preferred embodiments of formula (S1) include the following formulae (S1-x1) to (S1-x7). [ka]

[0025] In the above formula, X p is -(CH2) a A1 is an oxygen atom or -COO-* (wherein the bond marked with "*" is (CH2)), -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CHO-, -CHOCO-, -COO-, or -OCO-. a2 A2 is an oxygen atom or *-COO- (where the bond marked with "*" is (CH2)a2 a3 is 0 or 1, a1 and a2 are each independently an integer of 1 to 10, and Cy is a 1,4-cyclohexylene group or a 1,4-phenylene group. 1 is a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms.

[0026] A preferred embodiment of the above formula (S2) is the following formula (S2-x). In formula (S2-x), X represents formula (X1), (X2), or (X3), Col represents formula (Col1), (Col2), or (Col3), and G represents formula (G1), (G2), (G3), or (G4). Me represents a methyl group. * represents a bond. [ka]

[0027] (Polyimide precursor) The polymer (A) (hereinafter also referred to as polyimide precursor (A)) which is a polyimide precursor is obtained by reacting a diamine component with a tetracarboxylic acid component. Examples of diamines contained in the diamine component include those described below. The diamines may be used alone or in combination of two or more.

[0028] When the polyimide precursor (A) has a carboxy group, the carboxy group may be a carboxy group derived from a tetracarboxylic dianhydride or a derivative thereof (for example, a carboxy group generated by ring-opening of a tetracarboxylic dianhydride or a derivative thereof), or a carboxy group derived from a carboxy group-containing diamine. The polyimide precursor (A) having a carboxy group may be synthesized using a carboxy group-containing diamine. Examples of carboxy group-containing diamines include 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, and diamines represented by the following formulae (3b-1) to (3b-4). Specific preferred examples of the diamines represented by the above formulas (3b-1) to (3b-4) are 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid. [ka] (In formula (3b-1), A 1 represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -C2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-, and m1 and m2 each independently represent an integer of 0 to 4, and m1 + m2 represents an integer of 1 to 4. In formula (3b-2), m3 and m4 each independently represent an integer of 1 to 5. In formula (3b-3), A 2 represents a linear or branched alkyl group having 1 to 5 carbon atoms, and m5 is an integer of 1 to 5. In formula (3b-4), A 3 and A 4 each independently represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -C2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-, and m6 is an integer of 1 to 4.

[0029] The proportion of the carboxyl group-containing diamine used is preferably 10 to 80 mol %, more preferably 30 to 70 mol %, based on the total diamine components, from the viewpoint of more suitably achieving the effects of the present invention.

[0030] Furthermore, when the polyimide precursor (A) has a structure represented by the above formula (S), the structure represented by the above formula (S) that the polyimide precursor (A) has may be derived from an aromatic diamine (d) having the structure represented by the above formula (S) in its side chain. The polyimide precursor (A) having the structure represented by the above formula (S) may be synthesized using an aromatic diamine (d) having the structure represented by the above formula (S) on its side chain. The proportion of the aromatic diamine (d) having the structure represented by the above formula (S) in its side chain is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, based on the total diamine components, from the viewpoint of more suitably achieving the effects of the present invention.

[0031] The aromatic diamine (d) preferably has at least one benzene ring. Specific examples of the aromatic diamine (d) include diamines represented by the following formula (d1) or formula (d2). [ka] (X is a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -(CH2) m -, -SO2-, -O-(CH2) m -O-, -OC(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -SO2-(CH2) m -, -CONH-(CH2) m -, -CONH-(CH2) m -NHCO- or -COO-(CH2) m represents a divalent organic group of -OCO-. m is an integer of 1 to 8. Y represents a structure represented by the above formula (S). In the above formula (d2), the two Ys may be the same or different.

[0032] Preferred examples of the diamine represented by the above formula (d1) include the following formulas (d1-1) to (d1-6): Preferred examples of the diamine represented by the above formula (d2) include the following formulas (d2-1) to (d2-6): [ka] [ka] (X v1 ~X v4 , X p1 ~X p8 are each independently -(CH2) a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CHO-, -CH2-OCO-, -COO-, or -OCO-; X V5 ~X V6 , X s1 ~X s4 each independently represents -O-, -CH2O-, -OCH2-, -COO- or -OCO-. X a ~X f represents a single bond, -O-, -NH-, -O-(CH2) m -O-, -C(CH3)2-, -CO-, -COO-, -CONH-, -(CH2) m -, -SO2-, -OC(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -NH-(CH2) m -NH-, -SO2-(CH2) m -, -SO2-(CH2) m -SO2-, -CONH-(CH2) m -, -CONH-(CH2) m -NHCO- or -COO-(CH2) m -OCO- represents R v1 ~R v4 , R 1a ~R 1h are each independently, -C n H 2n+1 (n is an integer of 3 to 10), or -OCn H 2n+1 (n is an integer from 3 to 10. m is an integer from 1 to 8.)

[0033] Diamines that can be used in the synthesis of the polyimide precursor (A) may be diamines other than the carboxyl group-containing diamines and aromatic diamines (d) (hereinafter also referred to as other diamines). Examples of the other diamines include the following diamines:

[0034] p-phenylenediamine, m-phenylenediamine, 4-(2-(methylamino)ethyl)aniline, diamines having a photoalignment group such as diamines represented by the following formulas (g-1) to (g-5), 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 1,2-bis(4-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(4-aminophenoxy)benzene 1,3-bis(4-aminophenoxy)benzene, 1,2-bis(4-aminophenoxy)ethane, 1,2-bis(4-amino-2-methylphenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 4-(2-(4-aminophenoxy)ethoxy)-3-fluoroaniline, di(2-(4-aminophenoxy)ethyl)ether, 4-amino-4'-(2-(4-aminophenoxy)ethyl)ether (4-aminophenoxy)ethoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)propane propane, diamines represented by the following formulae (nh-1) to (nh-8), 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine, 1,3-bis(4-aminophenethyl)urea, diamines having a photopolymerizable group at the terminal such as those represented by the following formulae (4b-1) to (4b-12), diamines having a radical initiation function such as those represented by the following formulae (R1) to (R5), 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 9,Diamines having a photosensitizing function that exhibits a sensitizing effect upon irradiation with light, such as 9-bis(4-aminophenyl)fluorene, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, 9-methyl-3,6-diaminocarbazole, 9-ethyl-3,6-diaminocarbazole, and 9-phenyl-3,6-diaminocarbazole, diamines having a heterocycle such as those of the following formulae (z-1) to (z-13), diamines having a diphenylamine skeleton such as those of the following formulae (Dp-1) to (Dp-9), a group "-N(D)-" (D represents a protecting group that is eliminated by heating and replaced with a hydrogen atom, and D is preferably a tert-butoxycarbonyl group) such as those of the following formulae (5-1) to (5-13), or a group "*-LO-D'" (* represents a bond to a nitrogen atom). L represents an alkylene group having 1 to 5 carbon atoms. D' represents a protecting group which is eliminated by heating and replaced with a hydrogen atom. D' is preferably a tert-butoxycarbonyl group. Examples of diamines include diamines having a siloxane bond such as diamines having the following formula (Ds-1), 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, and diamines represented by the following formula (Ds-1), diamines having an oxazoline structure such as diamines represented by the following formulas (Ox-1) to (Ox-2), aliphatic diamines such as 1,1-meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine; and alicyclic diamines such as 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl)cyclohexane. [ka] [ka] [ka] (n1 is an integer between 2 and 12.) [ka] (n2 is an integer between 0 and 12, and n3 is an integer between 2 and 12.) [ka] (In formulas (R3) to (R5), n is an integer of 2 to 6.) [ka] [ka] [ka] [ka] (Boc represents a tert-butoxycarbonyl group.) [ka] [ka]

[0035] Among the above other diamines, from the viewpoint of suitably obtaining the effects of the present invention, it is more preferable to use at least one diamine selected from the group consisting of diamines having the above photoalignment group, diamines having the above photopolymerizable group at the terminal, diamines having the above radical initiation function, and diamines having the above photosensitizing function (hereinafter, these are also collectively referred to as "specific photoreactive diamines").

[0036] In a more preferred embodiment of the present invention, the polyimide precursor (A) is obtained using a diamine component containing the aromatic diamine (d) and the specific photoreactive diamine, and a tetracarboxylic acid component. The total amount of the aromatic diamine (d) and the specific photoreactive diamine is 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, based on the total amount of the diamine component.

[0037] The polymer component (A) may further have a photopolymerizable group. When the polymer component (A) further has a photopolymerizable group, the effects of the present invention, such as light transmittance in a transmitted state and adhesion between the polymer liquid crystal layer and the substrate, can be further improved. When the polyimide precursor (A) has a photopolymerizable group, the photopolymerizable group of the polyimide precursor (A) may be derived from a diamine having the above-mentioned photopolymerizable group at its terminal. The polyimide precursor (A) having the photopolymerizable group may be synthesized using a diamine having the photopolymerizable group at its terminal. From the viewpoint of more suitably achieving the effects of the present invention, the proportion of the diamine having the above-mentioned photopolymerizable group at its terminal is preferably 5 to 70 mol %, more preferably 10 to 70 mol %, and even more preferably 10 to 50 mol %, based on the total diamine component.

[0038] Tetracarboxylic acid components that can be used in the synthesis of the polyimide precursor (A) include acyclic aliphatic tetracarboxylic acid dianhydrides or derivatives thereof, alicyclic tetracarboxylic acid dianhydrides or derivatives thereof, and aromatic tetracarboxylic acid dianhydrides or derivatives thereof. Among these, tetracarboxylic acid dianhydrides having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure, or derivatives thereof, are preferred. The tetracarboxylic acid component that can be used in the synthesis of the polyimide precursor (A) is preferably a tetracarboxylic acid dianhydride or derivative thereof represented by the following formula (T). Examples of derivatives of the tetracarboxylic acid dianhydrides include tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides. The tetracarboxylic acid dianhydrides or derivatives thereof may be used alone or in combination of two or more. The aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring. Acyclic aliphatic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, they do not necessarily have to be composed of chain hydrocarbon structures only, and may also contain an alicyclic structure or an aromatic ring structure. Alicyclic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an alicyclic structure. However, none of these four carboxy groups are bonded to an aromatic ring. Furthermore, they do not necessarily have to be composed solely of an alicyclic structure; they may also contain a chain hydrocarbon structure or an aromatic ring structure. [ka] (X represents a structure selected from any of the following formulas (x-1) to (x-13).) [ka] (R 1 ~R 4 R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group. 5 and R 6 each independently represents a hydrogen atom or a methyl group. j and k are integers of 0 or 1, and A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group, or an amide group. *1 is a bond bonded to one acid anhydride group, and *2 is a bond bonded to the other acid anhydride group. In the above formula (x-13), the two A2 may be the same or different.

[0039] More preferred examples of the above formula (x-1) include the following formulae (X1-1) to (X1-6), in which * represents a bond.

[0040] [ka]

[0041] Preferred specific examples of the above formulae (x-12) and (x-13) include the following formulae (x-14) to (x-29), where * represents a bond. [ka] [ka]

[0042] Preferred examples of the tetracarboxylic dianhydride represented by the formula (T) or a derivative thereof include tetracarboxylic dianhydrides represented by the formula (T) in which X is represented by the formulas (x-1) to (x-7), (x-11) to (x-13), or a derivative thereof, and more preferred examples of the tetracarboxylic dianhydrides represented by the formula (T) in which X is represented by the formulas (x-1), (x-3), or (x-5), or a derivative thereof.

[0043] The proportion of the tetracarboxylic dianhydride represented by the above formula (T) or a derivative thereof used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, relative to 1 mol of the total tetracarboxylic acid components used.

[0044] <Production of Polyimide Precursor and Polyimide> The polyimide in the polymer (A) of the present invention is an imidized product of the polyimide precursor (A) and is obtained by dehydrating and cyclizing the polyimide precursor (A). Specific examples of the polyimide precursor include polyamic acid and polyamic acid ester.

[0045] (Synthesis of polyamic acid) Polyamic acid is synthesized by reacting a diamine component containing the diamine described above with a tetracarboxylic acid component containing the tetracarboxylic acid dianhydride or a derivative thereof in an organic solvent. The ratio of the tetracarboxylic acid dianhydride and diamine used in the polyamic acid synthesis reaction is preferably such that 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic acid dianhydride are present per equivalent of the amino group of the diamine, and more preferably 0.3 to 1.2 equivalents. As with a typical condensation polymerization reaction, the closer the equivalent of the acid anhydride group of the tetracarboxylic acid dianhydride is to 1 equivalent, the higher the molecular weight of the resulting polyamic acid. The reaction temperature in the synthesis reaction of polyamic acid is preferably −20 to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. The synthesis reaction of polyamic acid can be carried out at any concentration, preferably 1 to 50 mass %, more preferably 5 to 30 mass %. The reaction can be carried out at a high concentration in the early stage, and then a solvent can be added.

[0046] Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. When the polymer has high solubility in the solvent, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents represented by the following formulas [D-1] to [D-3] can be used. [ka] (In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-2], D 2 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D 3 represents an alkyl group having 1 to 4 carbon atoms.

[0047] Specific examples of the solvents represented by the above formulas [D-1] to [D-3] include propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether.

[0048] The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0049] Furthermore, polyimide can be obtained by ring-closing (imidization) the polyimide precursor. The imidization ratio in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization ratio does not necessarily have to be 100% and can be adjusted as desired depending on the application and purpose.

[0050] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor.

[0051] When the polyimide precursor is thermally imidized in a solution, the temperature is 100 to 400° C., preferably 120 to 250° C., and it is preferable to carry out the imidization reaction while removing water produced by the imidization reaction from the system.

[0052] Catalytic imidization of a polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring the mixture at preferably -20 to 250°C, more preferably 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times, more preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is preferably 1 to 50 times, more preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0053] To recover the resulting polyimide precursor or polyimide from a reaction solution of the polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the precipitated polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0054] <End-capping agent> In synthesizing the polyimide precursor or polyimide of the present invention, a terminal-capping polymer may be synthesized using a tetracarboxylic acid component containing the above-mentioned tetracarboxylic dianhydride or its derivative, a diamine component containing the above-mentioned diamine, and an appropriate terminal-capping agent. The terminal-capping polymer has the effect of improving the film hardness of the alignment film obtained by coating and improving the adhesion properties between the sealant and the alignment film. Examples of the terminals of the polyimide precursor or polyimide in the present invention include an amino group, a carboxy group, an acid anhydride group, or a derivative thereof. The amino group, carboxy group, acid anhydride group, or isocyanate group can be obtained by a conventional condensation reaction or by blocking the terminals with the following terminal blocking agents, and the derivatives can be obtained in the same manner, for example, using the following terminal blocking agents.

[0055] Examples of the end-capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonates such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; Examples of the isocyanate include carbonyl compounds; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; and monoisocyanate compounds having an unsaturated bond, such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, and structures represented by the following formulas [1a] to [1d]. [ka] (X 3 represents an alkylene group having 1 to 5 carbon atoms, a benzene ring, or a cyclohexane ring; X 4 represents an alkylene group having 1 to 5 carbon atoms, a benzene ring, or a cyclohexane ring. [ka] (X 5 represents an alkylene group having 1 to 5 carbon atoms, a benzene ring, or a cyclohexane ring; X 6 represents an alkylene group having 1 to 5 carbon atoms, a benzene ring, or a cyclohexane ring.

[0056] The proportion of the end-capping agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0057] (Polymer of a monomer having a polymerizable unsaturated bond) In the polymer of a monomer having a polymerizable unsaturated bond (hereinafter also referred to as polymer (uA)), examples of the monomer having a polymerizable unsaturated bond include (meth)acrylic compounds (including unsaturated carboxylic acids, unsaturated carboxylic acid esters, and unsaturated polycarboxylic acid anhydrides), (meth)acrylic acid amide compounds, aromatic vinyl compounds, conjugated diene compounds, maleimide group-containing compounds, α-methylene-γ-butyrolactone compounds, and vinyl compounds. From the viewpoints of transparency and material strength, polymer (uA) is preferably a polymer of a monomer component containing a (meth)acrylic compound among the above. When synthesizing polymer (uA), the proportion of the (meth)acrylic compound used is preferably 50 mol% or more, more preferably 60 mol% or more, based on the total amount of monomers used in the synthesis. The above-mentioned monomers having a polymerizable unsaturated bond may be used alone or in combination of two or more.

[0058] The polymer (uA) can be obtained, for example, by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. Examples of the polymerization initiator include azo compounds such as 2,2'-azobis(isobutyronitrile) and 2,2'-azobis(2,4-dimethylvaleronitrile). The polymerization initiator is preferably used in an amount of 0.01 to 30 parts by mass per 100 parts by mass of all monomers used in the reaction. The polymerization reaction is preferably carried out in an organic solvent. Examples of organic solvents used in the reaction include alcohols, ethers, ketones, amides, esters, and hydrocarbon compounds, with diethylene glycol ethyl methyl ether and propylene glycol monomethyl ether acetate being preferred. The reaction temperature is preferably 30 to 120°C. The amount of organic solvent (a) used is preferably such that the total amount of monomers (b) used in the reaction is 0.1 to 60% by mass relative to the total amount of the reaction solution (a+b).

[0059] When a polymer having the above-mentioned carboxy group or the structure represented by formula (S) in its side chain is to be incorporated into an alignment film-forming material as polymer (uA), for example, (i) a polymer having an epoxy group in its side chain is synthesized by polymerization using, as at least a part of the raw material, a monomer having an epoxy group and a polymerizable unsaturated bond, and (iii) the polymer containing the epoxy group is then reacted with a carboxylic acid having two or more carboxy groups or a carboxylic acid having the structure represented by formula (S) to obtain the desired polymer (uA). Alternatively, a polymerization method using a monomer having a carboxy group and a polymerizable unsaturated bond or a monomer having the structure represented by formula (S) and a polymerizable unsaturated bond may also be employed.

[0060] When the polymer of the monomer having a polymerizable unsaturated bond has a carboxy group, specific examples of the monomer having a carboxy group and a polymerizable unsaturated bond include carboxy group-containing (meth)acrylate compounds such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, 2-hydroxyethyl(meth)acrylic acid, 2-carboxyethyl(meth)acrylate, 2-carboxypropyl(meth)acrylate, 5-carboxypentyl(meth)acrylate, 2-acryloyloxyethylsuccinic acid, and 2-methacryloyloxyethylsuccinic acid; vinyl group-containing aromatic carboxylic acids such as 4-vinylbenzoic acid; carboxy group-containing maleimides such as 4-maleimidobenzoic acid; and carboxy group-containing (meth)acrylamide compounds such as N-(carboxyphenyl)methacrylamide and N-(carboxyphenyl)acrylamide. The carboxy group contained in the polymer of the monomer having a polymerizable unsaturated bond may be derived from a compound selected from the group consisting of a carboxy group-containing (meth)acrylate compound; a vinyl group-containing aromatic carboxylic acid; a carboxy group-containing maleimide; and a carboxy group-containing (meth)acrylamide compound.

[0061] When the polymer of the monomer having a polymerizable unsaturated bond has a structure represented by the formula (S), a specific example of the monomer having the structure represented by the formula (S) and a polymerizable unsaturated bond includes a compound represented by the following formula (S-mA): [ka] (P represents a (meth)acryloyloxy group, a styryl group, a vinyloxy group (CH2=CH-O-), a maleimide group, or an α-methylene-γ-butyrolactone structure. X and J have the same meanings as X and J in the above formula (S), including preferred embodiments. However, when P is a (meth)acryloyloxy group, a vinyloxy group (CH2=CH-O-), or a maleimide group, X is a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -CON(CH3)-, -COO-, or -((CH2) a1-A1) m1 -(a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1 and A1 each independently have the above definition), and J represents the same group as J in the above formula (S). The structure represented by formula (S) possessed by the polymer of the monomer having a polymerizable unsaturated bond may be derived from a compound selected from the group consisting of compounds represented by formula (S-mA).

[0062] As a monomer for obtaining polymer (uA), a monomer having a polymerizable unsaturated bond other than the above-mentioned monomer having a carboxy group and a polymerizable unsaturated bond and the monomer having a structure represented by formula (S) and a polymerizable unsaturated bond may be used. Examples of the above-mentioned other monomer having a polymerizable unsaturated bond include the following monomers.

[0063] amino group-containing (meth)acrylate compounds such as aminoethyl (meth)acrylate and aminopropyl (meth)acrylate; (meth)acrylamide compounds containing a hydroxymethyl group or an alkoxymethyl group, such as N-hydroxymethyl(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide; compounds having an epoxy skeleton, such as allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 2-methylglycidyl methacrylate, α-ethylglycidyl acrylate, α-n-propylglycidyl acrylate, α-n-butylglycidyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, α-ethyl-6,7-epoxyheptyl acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3,4-epoxycyclohexylmethyl methacrylate, 3-ethenyl-7-oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, and 1,7-octadiene monoepoxide; compounds having an oxetane skeleton, such as 3-(acryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)oxetane, 3-(acryloyloxymethyl)-2-methyloxetane, 3-(methacryloyloxymethyl)-2-methyloxetane, 3-(acryloyloxymethyl)-3-ethyloxetane, and 3-(methacryloyloxymethyl)-3-ethyloxetane; compounds having a nitrogen-containing aromatic heterocycle, such as 2-(2-pyridylcarbonyloxy)ethyl (meth)acrylate, 2-(3-pyridylcarbonyloxy)ethyl (meth)acrylate, and 2-(4-pyridylcarbonyloxy)ethyl (meth)acrylate; (meth)acrylic acid ester compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-propyl-2-adamantyl (meth)acrylate, 8-methyl-8-tricyclodecyl (meth)acrylate, and 8-ethyl-8-tricyclodecyl (meth)acrylate; (Meth)acrylic acid amide compounds such as acrylamide, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide; Vinyl ether compounds such as methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, and vinyl carbazole; aromatic vinyl compounds such as styrene, methylstyrene, chlorostyrene, and bromostyrene; and maleimide group-containing compounds such as maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

[0064] The weight-average molecular weight (Mw) of the polymer contained in the alignment film-forming material, measured by gel permeation chromatography (GPC) in terms of polystyrene, is set appropriately depending on the type of polymer, but is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) in terms of polystyrene measured by GPC, is preferably 15 or less, and more preferably 10 or less. The solution viscosity of the polymer is set appropriately depending on the type of polymer, but for example, polyimide precursors and polyimides, when prepared into a 10% by mass solution, preferably have a solution viscosity of 10 to 800 mPa·s, and more preferably 15 to 500 mPa·s. The solution viscosity (mPa·s) was measured at 25°C using an E-type rotational viscometer for a 10% by mass polymer solution prepared using a good solvent for these polymers (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0065] (Compound (B)) The alignment film-forming material of the present invention contains the following component (B) (compound (B)) (hereinafter also referred to as "specific adhesive compound"). Component (B): A compound (B) having a molecular weight of 2000 or less, which has in its molecule at least one epoxy group and one group having a polymerizable unsaturated bond, and the epoxy group and the group having a polymerizable unsaturated bond are linked via a divalent organic group having an alkylene group having 4 to 20 carbon atoms. The compound (B) may be one type or two or more types. This configuration promotes crosslinking between the carboxyl groups of the polymer component (A) and the epoxy groups of the compound (B), and also promotes crosslinking between the polymerizable unsaturated bonds of the compound (B) and the polymer liquid crystal layer, resulting in high adhesion. Furthermore, by increasing the number of carbon atoms in the alkylene of the compound (B) to 4 or more, the hydrophobicity is enhanced, making it easier for the polymerizable unsaturated bond sites to be present at the alignment film interface, resulting in higher adhesion. Furthermore, since the compound (B) has a small number of polymerizable unsaturated bonds in its molecule, the alignment film maintains high liquid crystal alignment and achieves high transmittance in the transmission state.

[0066] Examples of the group having a polymerizable unsaturated bond include a (meth)acryloyloxy group, a styryl group, a (meth)acrylamide group, a vinyl group, a vinylidene group, a vinyloxy group (CH2=CH-O-), and a maleimide group.

[0067] From the viewpoint of more suitably achieving the effects of the present invention, the compound (B) is preferably a compound represented by the following formula (b). [ka] (m is an integer of 1 to 6, P represents a group having a polymerizable unsaturated bond, and R represents an (m+1)-valent organic group having an alkylene group having 4 to 20 carbon atoms.

[0068] In order to more suitably obtain the effects of the present invention, it is preferable that the above R further contains at least one of an aromatic hydrocarbon group or an alicyclic hydrocarbon group.

[0069] Examples of the (m+1)-valent organic group represented by R in the above formula (b) include a (2k1+1)-valent organic group represented by the following formula (r1), a (k2+1)-valent organic group represented by the following formula (r2), or a (k3+1)-valent organic group represented by the following formula (r3). [ka] (Ak1 and Ak2 represent an alkylene group having 4 to 20 carbon atoms. Ak3 represents a (k3+1)-valent acyclic aliphatic hydrocarbon group having 4 to 20 carbon atoms. A2 and A3 represent an alkylene group having 1 to 10 carbon atoms. Ar1 represents a (2k1+1)-valent aromatic hydrocarbon group or a (2k1+1)-valent alicyclic hydrocarbon group, and Ar2 represents a (k2+1)-valent aromatic hydrocarbon group or a (k2+1)-valent alicyclic hydrocarbon group. L1, L2, L 2’ , L 2’’ , L3, L 3’ each independently represents a single bond, —O—, —CO—, —NH—, —NHCO—, —CONH—, —OCO— or —COO—. k1 is an integer of 1 to 2. k2 and k3 are integers of 1 to 4. m1 and m2 are integers of 1 to 3. i2 and i3 are integers of 0 to 2. Ar1, Ar2, A2, A3, L1, L2, L 2’ , L 2’’ , L3, L 3’ If there are two or more i1, i2, and i3, there are two or more Ar1, Ar2, A2, A3, L1, L2, L 2’ , L 2’’ , L3, L 3’ , i2 and i3 may each independently be the same or different. *1 represents the bond bonded to the glycidyl group, and *2 represents the bond bonded to P.)

[0070] Specific examples of the aromatic hydrocarbon group in Ar1 and Ar2 include benzene, naphthalene, and anthracene. Specific examples of the alicyclic hydrocarbon group in Ar1 and Ar2 include cyclobutane, cyclopentane, cyclohexane, cyclodecane, norbornene, adamantane, and a steroid skeleton. The hydrogen atoms of the aromatic hydrocarbon group and alicyclic hydrocarbon group may be substituted with a substituent. Specific examples of the acyclic aliphatic hydrocarbon group in Ak3 above include alkyl groups having 4 to 20 carbon atoms, such as n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, and decyl; and alkenyl groups having 4 to 20 carbon atoms, such as 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl, from which k3 hydrogen atoms have been removed. The hydrogen atoms of the acyclic aliphatic hydrocarbon group may be substituted with a substituent. Specific examples of the substituent that the above-mentioned aromatic hydrocarbon group, alicyclic hydrocarbon group, and acyclic aliphatic hydrocarbon group may have include a substituent selected from the group consisting of a halogen atom, a halogen atom-containing alkyl group, a halogen atom-containing alkoxy group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a heteroatom-containing group in which a carbon-carbon bond in any methylene group of the above-mentioned halogen atom-containing alkyl group, halogen atom-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted by an oxygen atom.

[0071] The group "-(Ar1-L1)" in the above formula (r1) m1 -" and the group "-(Ar2-L 2’’ ) m2 A preferred specific example of "-" is an organic group represented by the following formula (w). [ka] (m represents an integer of 0 to 2. Ring A and ring A' each independently represent a benzene ring or a cyclohexane ring, and any hydrogen atom on the benzene ring or cyclohexane ring may be substituted with a monovalent organic group. The bonding positions of the benzene ring and cyclohexane ring include the 1,4-positions and the 1,3-positions, and the 1,4-positions are preferred. When there are two or more rings A, the bonding positions may be the same or different. L represents a single bond, -O-, -CO-, -OCO-, or -COO-. *1 and *2 represent a bond, and *2 represents a bond bonding to Ak1 or Ak2. When there are two or more Ls and rings A, the two or more Ls and rings A each independently may be the same or different.)

[0072] Preferred specific examples of the compound represented by the above formula (b) include compounds represented by the following formulas (b-1) to (b-10). [ka]

[0073] More specific examples of the compound represented by the formula (b) include compounds represented by the following formulae (C1) to (C3): The compounds represented by the following formulae (C2) to (C3) are novel compounds not yet published in the literature. [ka]

[0074] The content of the compound (B) contained in the alignment film-forming material of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the polymer component (A).

[0075] (Alignment film forming material) The alignment film-forming material of the present invention contains the above-mentioned polymer component (A) and compound (B) as essential components, and is preferably prepared by dissolving them in an organic solvent. The blending ratio of the polymer component (A) used in the alignment film-forming material of the present invention is not particularly limited, but for example, the content of the polymer component (A) contained in the alignment film-forming material is 0.1 to 30 mass %, preferably 1 to 10 mass %, based on the alignment film-forming material. The alignment film forming material of the present invention is preferably an alignment film forming agent, and more preferably a material for forming an alignment film of a polymer dispersed liquid crystal element (alignment film forming agent for a polymer dispersed liquid crystal element).

[0076] The organic solvent contained in the alignment film-forming material is not particularly limited as long as it can dissolve the polymer, and examples thereof include lactone solvents such as γ-valerolactone and γ-butyrolactone; γ-butyrolactam, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, and N-methoxy Lactam solvents such as N-propyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone; amide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, tetramethylurea, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide;Cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, 2,6-dimethyl-4-heptanone (diisobutyl ketone), methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether Examples of suitable solvents include ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether, propylene glycol diacetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, isoamyl propionate, isoamyl isobutyrate, diisopropyl ether, and diisopentyl ether; carbonate solvents such as ethylene carbonate and propylene carbonate, 1-hexanol, cyclohexanol, 1,2-ethanediol, and 2,6-dimethyl-4-heptanol (diisobutylcarbinol). These may be used alone or in combination of two or more.

[0077] When the alignment film forming material of the present invention is applied to a plastic substrate or the like, the organic solvent used in the alignment film forming material may be composed of a solvent having a boiling point of 190° C. or less at 1 atmosphere. Preferred solvent compositions when composed of a solvent having a boiling point of 190° C. or less at 1 atmosphere include cyclohexanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol monobutyl ether, cyclopentanone and propylene glycol monobutyl ether, cyclohexanone and diethylene glycol monoethyl ether, cyclopentanone and diethylene glycol monoethyl ether, cyclohexanone and diisobutyl ketone, cyclopentanone and diisobutyl ketone, methyl isobutyl ketone and propylene glycol monobutyl ether, methyl ethyl ketone and propylene glycol monoethyl ether, and the like. Examples of solvent compositions include combinations of cyclohexanone and n-butyl acetate, cyclopentanone and n-butyl acetate, 4-hydroxy-4-methyl-2-pentanone and ethylene glycol monobutyl ether, cyclohexanone and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and diethylene glycol diethyl ether, cyclopentanone and diethylene glycol diethyl ether, cyclohexanone and n-butyl acetate, cyclopentanone and n-butyl acetate, 4-hydroxy-4-methyl-2-pentanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol diacetate, or cyclopentanone and propylene glycol diacetate. The type and content of such organic solvents are appropriately selected depending on the coating device, coating conditions, coating environment, etc. of the alignment film-forming material.

[0078] The alignment film-forming material of the present invention contains the above-mentioned polymer component (A) and compound (B) as essential components, but may contain other components as necessary. Examples of such other components include polymers other than the polymer constituting the polymer component (A) (hereinafter also referred to as "other polymers"); crosslinkable compounds other than the compound (B) described above, such as crosslinkable compounds (c-1) having one or more substituents selected from the group consisting of epoxy groups, isocyanate groups, oxetane groups, cyclocarbonate groups, blocked isocyanate groups, hydroxy groups, and alkoxy groups; and crosslinkable compounds other than the compound (B) described above, such as crosslinkable compounds (c-2) having a polymerizable unsaturated group; functional silane compounds; metal chelate compounds; curing accelerators; surfactants; antioxidants; sensitizers; preservatives; compounds for adjusting the dielectric constant or electrical resistance of the alignment film; alignment additives (excluding the compound (B) described above); photoradical generators; photoacid generators; photobase generators; ultraviolet absorbers; and light stabilizers.

[0079] When the crosslinkable compound (c-1) has an epoxy group, particularly preferred examples include compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, and bis(N,N-diglycidyl-4-aminocyclo bis(N,N-diglycidylaminomethyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, and isocyanurate compounds such as triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.).

[0080] The above are examples of the crosslinkable compound, and the present invention is not limited to these. The crosslinkable compound used in the alignment film-forming material of the present invention may be one type or a combination of two or more types. The content of the crosslinkable compound in the alignment film-forming material of the present invention is 0.1 to 50 parts by mass, or 1 to 50 parts by mass, or 1 to 30 parts by mass, relative to 100 parts by mass of all polymer components.

[0081] The other polymers are not particularly limited, and examples thereof include polyimide precursors that do not have either a carboxy group or the structure represented by the above formula (S), polyimides that are imidized products thereof, polymers of monomers having polymerizable unsaturated bonds, polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, and poly(styrene-phenylmaleimide) derivatives. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, 2000, 3000 (manufactured by Cray Valley) and GSM301 (manufactured by Gifu Shellac Co., Ltd.), a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAN-600 (manufactured by Kuraray), and a specific example of poly(vinyl ether-maleic anhydride) copolymers includes GANTREZ AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by ISP Japan Co., Ltd.) Note that two or more of the other polymers may be used in combination. When other polymers are used, the proportion of the other polymers used is preferably 50% by mass or less, more preferably 0.1 to 40% by mass, and even more preferably 0.1 to 30% by mass, based on the total amount of polymers contained in the alignment film-forming material.

[0082] Preferred specific examples of the crosslinkable compounds (c-1) and (c-2) include compounds represented by the following formulas (CL-1) to (CL-16). [ka] [ka] (n2 represents an integer from 1 to 10. m2 represents an integer from 1 to 10.)

[0083] Examples of compounds for adjusting the dielectric constant and electrical resistance include monoamines having a nitrogen-containing aromatic heterocycle, such as 3-picolylamine. When using a monoamine having a nitrogen-containing aromatic heterocycle, the amount is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the alignment film-forming material.

[0084] Preferred specific examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Examples of functional silane compounds include silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. When a functional silane compound is used, its amount is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the alignment film-forming material.

[0085] A preferred example of the alignment additive is a compound (also referred to as a specific compound Ad) having a molecular weight of 2000 or less, in which an alignment side chain structure is bonded, directly or via a linking group, to one structure selected from the group consisting of formulas (p-1) to (p-12) below. The alignment side chain structure preferably contains at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocycle, or a steroid skeleton. By introducing the specific compound Ad, it is possible to improve the transparency and scattering properties of a liquid crystal element that switches between a transparent state and a scattering state of the liquid crystal. [ka]

[0086] B A represents a hydrogen atom or a benzene ring. B ~B D Each of the symbols independently represents an alkyl group having 1 to 5 carbon atoms. * represents a bond.

[0087] A preferred specific example of the specific compound Ad is a compound represented by the following formula (ad). [ka] (P represents one structure selected from the group consisting of the above formulas (p-1) to (p-12). When P is one of the above formulas (p-1) to (p-3), L1 represents -(CH2) k1 -O- (k1 is an integer of 1 to 12), When P is (p-4) to (p-11), it is a single bond or -(CH2) k1 -O- (k1 is an integer of 1 to 12), When P is the above formula (p-12), -L-(CH2) k1 -O- (L represents a single bond, -O-, -CHO-, -CONH-, -NHCO-, -CON(CH)-, -N(CH)CO-, -COO- or -OCO-; k1 represents an integer of 1 to 12). C1 represents a cyclohexylene group or a phenylene group. L2 is a single bond, -(CH2) c represents - (c is an integer of 1 to 15), -O-, -CHO-, -COO- or -OCO-. Among these, a single bond, -COO- or -OCO- is preferred in terms of availability of raw materials and ease of synthesis. n is an integer of 1 to 4. Among these, 1 or 2 is preferred from the viewpoint of the optical properties of the liquid crystal device. R represents an alkyl group having 1 to 18 carbon atoms, a fluorine atom-containing alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or a fluorine atom-containing alkoxy group having 1 to 18 carbon atoms. Of these, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms is preferred. An alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms is more preferred. When there are two or more C1 and L2, the two or more C1 and L2 may be independently the same or different.

[0088] The proportion of the specific compound Ad used in the alignment film-forming material is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and particularly preferably 1 to 10 parts by mass, per 100 parts by mass of the polymer component (A) in terms of the optical properties of the liquid crystal device. Furthermore, the specific compound Ad can be used alone or in combination of two or more types, depending on the properties.

[0089] Specific examples of the photoradical generator, photoacid generator, and photobase generator include the compounds described on pages 54 to 56 of International Publication No. 2014 / 171493 (published October 23, 2014). Among them, it is preferable to use a photoradical generator in view of adhesion between the liquid crystal layer and the alignment film of the liquid crystal element.

[0090] Examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as titanium dioxide, cerium oxide, zinc oxide, and iron oxide, and organic ultraviolet absorbers such as benzotriazoles, triazines, and benzophenones. Among these, triazine ultraviolet absorbers are preferred. Hydroxyphenyltriazine ultraviolet absorbers are more preferred as the triazine ultraviolet absorber. Examples of the hydroxyphenyltriazine ultraviolet absorber include 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4-bis[2-hydroxy-4-butoxyphenyl]-1,3,5-triazine. Preferred examples thereof include 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, etc. These may be used alone or in combination of two or more.

[0091] Examples of the light stabilizer include hindered amine light stabilizers (HALS). The hindered amine light stabilizer is preferably a hindered amine light stabilizer having a reactive functional group. The reactive functional group is not particularly limited as long as it has photoreactivity, and preferred examples thereof include functional groups having an ethylenic double bond such as a (meth)acryloyl group, a vinyl group, and an allyl group, and at least one selected from these is preferred. Of these, a (meth)acryloyl group is preferred. Preferred examples of the hindered amine light stabilizer having such a reactive functional group include 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine), and the like.

[0092] The solids concentration of the alignment film-forming material (the ratio of the total mass of the alignment film-forming material to the total mass of the alignment film-forming material, excluding the organic solvent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably in the range of 1 to 10% by mass. The preferred solids concentration range varies depending on the method used to apply the alignment film-forming material to the substrate. For example, when using a spin coating method, a solids concentration in the range of 1.5 to 4.5% by mass is particularly preferred. When using a printing method, a solids concentration in the range of 3 to 9% by mass is particularly preferred, thereby resulting in a solution viscosity in the range of 12 to 50 mPa·s. When using an inkjet method, a solids concentration in the range of 1 to 5% by mass is particularly preferred, thereby resulting in a solution viscosity in the range of 3 to 15 mPa·s.

[0093] (Alignment film / liquid crystal element) The alignment film of the present invention is obtained from the alignment film-forming material. The alignment film of the present invention can be used as a liquid crystal alignment film for horizontal alignment or vertical alignment, but is suitable for PDLC or PNLC liquid crystal elements. The liquid crystal element of the present invention is provided with the alignment film.

[0094] The liquid crystal element of the present invention is a liquid crystal element having a dimming layer, the essential component of which is a polymer-liquid crystal composite containing a polymer phase and a liquid crystal phase, between a pair of electrode-equipped substrates with electrode surfaces arranged opposite each other. Here, the polymer-liquid crystal composite is formed by polymerization of a polymerizable compound contained in the light-controlling layer-forming material described later, and is preferably a polymer-dispersed liquid crystal in which liquid crystal is dispersed in a polymer. FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal element of the present invention, and the liquid crystal element (100) comprises a pair of substrates consisting of a first substrate (11) and a second substrate (17), transparent electrodes (12) and (16) provided on the first substrate (11) and the second substrate (17), respectively, liquid crystal alignment films (13) and (15) formed on the transparent electrodes (12) and (16), respectively, and a light control layer (14) arranged between the liquid crystal alignment films (13) and (15). The light-controlling layer (14) is a layer that has the function of changing the transparency depending on the state of an electric field applied by the transparent electrodes (12) and (16). The thickness of the light-controlling layer (14) is preferably 1 to 30 μm, more preferably 1 to 20 μm, and even more preferably 1 to 15 μm, from the viewpoint of controlling the alignment state of the liquid crystal material and suitably exhibiting the light-controlling function. The light-controlling layer (14) is formed from a polymer-dispersed liquid crystal, the essential component of which is a polymer-liquid crystal composite containing a polymer phase and a liquid crystal phase. The polymer-dispersed liquid crystal is not particularly limited, but examples include a transparent polymer material in which droplets of liquid crystal molecules are dispersed (PDLC), a polymer network liquid crystal (PNLC) in which a polymer resin network is formed in a continuous layer of liquid crystal molecules, and a polymer-stabilized cholesteric liquid crystal (PSCT) using cholesteric liquid crystal molecules. Below, we will explain an example in which the light-controlling layer (14) is formed from the PDLC. Furthermore, the liquid crystal element of the present invention is any one of the above liquid crystal elements, characterized in that the light-controlling layer can be controlled to a light-scattering state or a light-transmitting state by an external electric field. More preferably, it is a normal mode polymer dispersed liquid crystal element that is in a cloudy (light scattering) state when no voltage is applied and is in a transparent state when voltage is applied, allowing light to pass through, or a reverse mode polymer dispersed liquid crystal element that is in a transparent state when no voltage is applied and is in a scattering state when voltage is applied. The liquid crystal device of the present invention can be produced, for example, by a method including the following steps (1) to (4). When the liquid crystal device of the present invention is a guest-host type light-adjusting device, it can be produced by a method in which a dye described below is contained in the liquid crystal composition. The alignment film only needs to be formed on at least one of the pair of substrates, and may be formed on either one or both sides.

[0095] (1) A step of applying an alignment film forming material to one or both of a pair of electrode-equipped substrates. The alignment film-forming material of the present invention is applied to one side of an electrode-attached substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, spin coating method, printing method, or inkjet method. The substrate is not particularly limited as long as it is highly transparent. Glass substrates, silicon nitride substrates, and film substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly(alicyclic olefin, preferably cycloolefin polymer), acrylic resins such as polymethyl methacrylate, polyolefin resins such as polypropylene (PP), and cellulose-based resins such as triacetyl cellulose can also be used. The above-mentioned film substrates are preferred when the liquid crystal device is used as a light-control window, etc. Furthermore, in reflective liquid crystal devices, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a light-reflective material such as aluminum can be used for the electrode. From the viewpoint of simplifying the process, it is preferable to use a substrate on which an ITO (Indium Tin Oxide) electrode, an IZO (Indium Zinc Oxide) electrode, an IGZO (Indium Gallium Zinc Oxide) electrode, an organic conductive film, or the like is formed for driving the liquid crystal. (2) Baking the coating After applying the alignment film-forming material, preheating (pre-baking) is preferably performed first to prevent dripping of the applied alignment film-forming material. The pre-baking temperature is preferably 30 to 150°C, more preferably 40 to 130°C, and particularly preferably 50 to 120°C. The pre-baking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes, and even more preferably 1 to 5 minutes. To completely remove the solvent, a further heating (post-baking) step may be performed. The post-baking temperature is preferably 80 to 190°C, more preferably 120 to 180°C. The post-baking time is preferably 5 to 30 minutes, more preferably 5 to 20 minutes. The film thus formed has a thickness of 1 to 1,000 nm, preferably 5 to 1,000 nm, and more preferably 10 to 1,000 nm.

[0096] The coating film formed in the above step (2) can be used as an alignment film as it is, but the coating film may also be subjected to an alignment ability imparting treatment, such as a rubbing treatment in which the coating film is rubbed in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton, or a photoalignment treatment in which the coating film is irradiated with polarized or unpolarized radiation.

[0097] In the photo-alignment treatment, the radiation to be irradiated onto the coating film can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, the radiation may be irradiated from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these. When irradiating with unpolarized radiation, the irradiation direction is an oblique direction.

[0098] (3) Step of placing a photochromic layer forming material A pair of electrode-equipped substrates, one or both of which have an alignment film formed thereon, is prepared as described above, and a light-controlling layer-forming material is placed between the two substrates arranged opposite each other. Specifically, the following three methods can be used. The first method is a method in which two substrates are arranged opposite each other with a gap (cell gap) between them so that the alignment films face each other, and is called a vacuum injection method. In PDLC-type liquid crystal elements and PNLC-type liquid crystal elements, the cell gap is preferably 1 to 100 μm, more preferably 2 to 50 μm, and even more preferably 5 to 20 μm. Next, the peripheries of the two substrates are bonded together using a sealant, and a light-controlling layer-forming material containing a liquid crystal composition, a polymerizable compound component, and optionally a polymerization initiator is injected into the substrate surfaces and the cell gap defined by the sealant, bringing the material into contact with the film surface, and the injection hole is then sealed.

[0099] The second method is called the ODF (One Drop Fill) method. For example, a UV-curable sealant is applied to a predetermined location on one of two substrates on which an alignment film has been formed, and the above-mentioned light-controlling layer-forming material is then dropped onto several predetermined locations on the alignment film surface. The other substrate is then attached so that the alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant.

[0100] Furthermore, a third method is a technique called a roll-to-roll method. Specifically, the light-controlling layer-forming material is applied to the film surface of the first electrode-attached substrate on the side where the transparent conductive film is provided, and then the first electrode-attached substrate is bonded to the film surface of the second glass substrate on which the transparent conductive film is provided so that the light-controlling layer-forming material is in contact with the film surface, thereby achieving a uniform thickness. The composite composition used in the present invention can be applied by any known or commonly used method, such as an applicator method, a bar coating method, a roll coating method, a direct gravure coating method, a reverse gravure coating method, an inkjet method, a die coating method, or a cap coating method. In any of these methods, it is desirable to further heat the liquid crystal composition used to a temperature at which it assumes an isotropic phase and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling.

[0101] (Light control layer forming material) The photochromic layer-forming material of the present invention contains a liquid crystal composition, a polymerizable compound component, and, if necessary, a polymerization initiator. The photochromic layer-forming material may further contain, if necessary, an alignment additive, an anisotropic dye, an ultraviolet absorber, a light stabilizer, and a chain transfer agent. The content of the liquid crystal composition in the photochromic layer-forming material is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 60 parts by mass or more, per 100 parts by mass of the photochromic layer-forming material. It is also preferably 90 parts by mass or less, and more preferably 80 parts by mass or less. The content of the polymerizable compound component is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, per 100 parts by mass of the photochromic layer-forming material. It is also preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

[0102] (Liquid Crystal Composition) Examples of liquid crystal compounds constituting the liquid crystal composition include nematic liquid crystals and smectic liquid crystals, with nematic liquid crystals being preferred, including Schiff-base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, and cubane liquid crystals. These liquid crystals may also be used in combination with cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonaate, and cholesteryl carbonate; chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck); and ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate. As the liquid crystal composition, various compositions such as those disclosed in JP-A Nos. 2007-009120 and 2011-246411 can be used. When used as a normal mode polymer dispersed liquid crystal element, positive type liquid crystal molecules exhibiting positive dielectric anisotropy are used as the liquid crystal composition, whereas when used as a reverse mode polymer dispersed liquid crystal element, negative type liquid crystal molecules exhibiting negative dielectric anisotropy are used as the liquid crystal composition.

[0103] (Polymerizable compound component) In PDLC-type liquid crystal elements and PNLC-type liquid crystal elements, the material for forming the light-controlling layer preferably contains a polymerizable compound component. As the polymerizable compound constituting the polymerizable compound component, a radically polymerizable polymerizable compound (monomer) and its oligomer are preferably used. Polymers obtained by polymerizing these monomers can also be used. Specific examples include (meth)acryloyl group-containing phosphate ester compounds, monofunctional (meth)acrylate compounds, bifunctional (meth)acrylate compounds, and trifunctional or higher functional (meth)acrylate compounds. Examples include monofunctional polymerizable compounds, bifunctional polymerizable compounds, and polyfunctional polymerizable compounds described on pages 58 to 60 of International Publication No. 2015 / 012368 (published January 29, 2015). Examples of (meth)acryloyl group-containing phosphate ester compounds include 2-(meth)acryloyloxyethyl acid phosphate (for example, "Light Ester P-1M" and "Light Acrylate P-1A" manufactured by Kyoeisha Chemical Co., Ltd.), bis(2-(meth)acryloyloxyethyl) acid phosphate (for example, "Light Ester P-2M" and "Light Acrylate P-2A" manufactured by Kyoeisha Chemical Co., Ltd., "KAYAMER PM-21" manufactured by Nippon Kayaku Co., Ltd.), and triacryloyloxyethyl phosphate (for example, "Viscoat #3PA" manufactured by Osaka Organic Chemical Industry Co., Ltd.), and other phosphate group-containing ethylenically unsaturated compounds having three or more ethylenically unsaturated groups. Preferred specific examples of the monofunctional (meth)acrylate compound include monofunctional (meth)acrylate compounds having an alicyclic structure such as isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate; and monofunctional (meth)acrylates having an alcoholic hydroxyl group such as 2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and partially ethoxylated 2-hydroxy(meth)acrylate. Acrylate compounds: monofunctional (meth)acrylate compounds having an epoxy group such as glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-n-propyl glycidyl (meth)acrylate, α-n-butyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4,5-epoxypentyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 6,7-epoxypentyl (meth)acrylate, α-ethyl 6,7-epoxypentyl (meth)acrylate, β-methylglycidyl (meth)acrylate, and 3,4-epoxycyclohexyl (meth)acrylate, or the compounds exemplified as the monomer for obtaining the polymer (uA) above. Preferred specific examples of bifunctional (meth)acrylate compounds and trifunctional or higher functional (meth)acrylate compounds include diethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 4,4'-biphenyl di(meth)acrylate, dicyclopentanyl di(meth)acrylate, glycerol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and hydroxypivalic acid-modified neopentyl glycol di(meth)acrylate (e.g., "KAYARAD HX-220" and "KAYARAD HX-620, etc.), 2,2,3,3,4,4-hexafluoropentanediol-1,5-dimethyl(meth)acrylate, or bifunctional (meth)acrylate compounds having a urethane bond (for example, bifunctional (meth)acrylate compounds having a urethane bond and an alicyclic structure, such as "EBECRYL 230," "EBECRYL 270," and "EBECRYL 9270," manufactured by Daicel-Allnex Corporation); trimethylolpropane tri(meth)acrylate ("NK Ester TMPT," manufactured by Shin-Nakamura Kogyo Co., Ltd.), pentaerythritol tri(meth)acrylate ("NK Ester A-TMMT," manufactured by Shin-Nakamura Kogyo Co., Ltd.), pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetraacrylate ("NK Ester TMPT," manufactured by Shin-Nakamura Kogyo Co., Ltd.), Examples of suitable (meth)acrylate compounds include tri- or higher functional (meth)acrylate compounds such as dipentaerythritol hexa(meth)acrylate (e.g., "NK Ester A-DPH" manufactured by Shin-Nakamura Kogyo Co., Ltd.), dipentaerythritol monohydroxypenta(meth)acrylate (e.g., "NK Ester A-DPH" manufactured by Shin-Nakamura Kogyo Co., Ltd.), and oligomers thereof.

[0104] The polymerizable compound may also be an ionic polymerizable compound, specifically a compound having at least one crosslinking group selected from the group consisting of a hydroxy group, a hydroxyalkyl group, and a lower alkoxyalkyl group. Specific examples include melamine derivatives and benzoguanamine derivatives described on pages 14 and 15 of WO 2014 / 171493 (published on October 23, 2014), 1,3,5-tris(methoxymethoxy)benzene, 1,2,4-tris(isopropoxymethoxy)benzene, 1,4-bis(sec-butoxymethoxy)benzene, 2,6-dihydroxymethyl-p-tert-butylphenol, and compounds containing epoxy or isocyanate groups described on pages 15 and 16 of WO 2014 / 171493 (published on October 23, 2014).

[0105] When an ionic polymerizable compound is used, an ionic initiator that generates an acid or base when exposed to ultraviolet light can be incorporated to promote the polymerization reaction. Specific examples include the ionic initiators described on pages 16 and 17 of International Publication No. 2014 / 171493 (published October 23, 2014).

[0106] (Polymerization initiator) The photochromic layer-forming material preferably contains a radical initiator (also called a polymerization initiator) that generates radicals when exposed to ultraviolet light in order to promote the polymerization reaction of the polymerizable compound, particularly the radical polymerization of the polymerizable compound. Specific examples include benzoin and its alkyl ethers, benzil ketals, acetophenones, acylphosphine oxides, benzophenones, aminobenzophenones, and the radical initiators described on pages 13 and 14 of International Publication WO 2014 / 171493 (published October 23, 2014). Examples of the acetophenone include hydroxyacetophenone, aminoacetophenone, dialkoxyacetophenone, and halogenated acetophenone. Examples of commercially available photopolymerization initiators include Irgacure (registered trademark) 907 (2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane), Irgacure 651 (2,2-dimethoxy-2-phenylacetophenone), Irgacure 369 (1-(4-morpholinophenyl)-2-(dimethylamino)-2-benzyl-1-butanone), Irgacure 184, and Omnirad 184 (1-hydroxycyclohexylphenyl ketone) manufactured by IGM Resins. The proportion of the polymerization initiator used is preferably in the range of 0.01 to 5 parts by mass per 100 parts by mass of the light-controlling layer-forming material. The photopolymerization initiators can be used alone or in combination of two or more. The radical initiators can also be used alone or in combination of two or more depending on their properties.

[0107] (Orientation additive) Examples of the alignment additive to be added to the light-controlling layer-forming material include the alignment additives to be contained in the alignment film-forming material described above, including the preferred ones. That is, the compounds of the specific compound Ad described above can be mentioned. From the viewpoint of the optical properties of the element, the amount of the alignment additive used in the light-controlling layer-forming material is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 30 parts by mass, and particularly preferably 1 to 20 parts by mass, relative to 100 parts by mass of the light-controlling layer-forming material. Two or more types of alignment additives can be used in combination.

[0108] (anisotropic dyes) The light-controlling layer-forming material may further contain an anisotropic dye (also called a dichroic dye or a dichroic pigment). The term "anisotropic dye" refers to a substance capable of anisotropically absorbing light in at least a part or all of the visible light region, for example, a wavelength range of 400 to 700 nm. The type of anisotropic dye is not particularly limited, and for example, a black dye or a color dye can be used. As such anisotropic dye, various known dyes such as those disclosed in JP-A-2007-009120 and JP-A-2011-246411 can be used. The blending ratio of the anisotropic dye can be, for example, 0.01 to 5 parts by mass per 100 parts by mass of the material for forming the light-controlling layer, but the above ratio can be changed as necessary.

[0109] (UV absorber / light stabilizer) The light-controlling layer-forming material may further contain an ultraviolet absorber or light stabilizer. Specific examples of the ultraviolet absorber or light stabilizer include the exemplified compounds described above. The content of the ultraviolet absorber is preferably 0.1 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, and even more preferably 0.3 to 1.5 parts by mass, relative to 100 parts by mass of the liquid crystal composition. The content of the light stabilizer is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass, and even more preferably 3 to 6 parts by mass, relative to 100 parts by mass of the liquid crystal composition.

[0110] (chain transfer agent) The light-controlling layer-forming material may further contain a chain transfer agent. Preferred examples of the chain transfer agent include butanediol dithiogluconate, pentaerythritol tetrakis(3-mercaptobutyrate), and triethylene glycol dimercaptan. This prevents the degree of crosslinking of the polymer phase from becoming too high, which makes the liquid crystal material more responsive to an electric field and enables low-voltage driving. The content of the chain transfer agent is preferably from 0.05 to 30 parts by mass, and more preferably from 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymerizable compound component.

[0111] (4) A step of polymerizing the light-controlling layer-forming material to form a light-controlling layer containing a polymer phase and a liquid crystal phase. Methods for polymerizing the photochromic layer-forming material of the present invention include a method of irradiating with active energy rays and a thermal polymerization method. Among these, the polymerization of the photochromic layer-forming material is preferably carried out by irradiating with ultraviolet light. Another example of a method for ultraviolet light irradiation is a method in which ultraviolet light is irradiated through one of a pair of electrode-equipped substrates. Examples of light sources for the ultraviolet light irradiation device include metal halide lamps and high-pressure mercury lamps. In this case, the wavelength of the ultraviolet light is preferably 250 to 400 nm. Of these, 310 to 370 nm is preferred. The intensity of the ultraviolet light irradiation can be appropriately determined by experiments or the like, and the end point may be determined by the concentration of the unreacted polymerizable compound in the liquid crystal composition or the like. The appropriate amount of UV light is 0.05J / cm 2 More than 1.0 J / cm is preferable, and 1.0 J / cm is particularly preferable. 2 That's all. The ultraviolet irradiation intensity is 1mW / cm 2 or more is preferable, and in order to complete the polymerization of the polymerizable compound, 20 mW / cm 2 The ultraviolet irradiation time is preferably 1 to 3600 seconds, more preferably 60 to 3600 seconds, and even more preferably 60 to 1800 seconds. During the ultraviolet irradiation, a voltage may be applied between the electrodes, or no voltage may be applied between the electrodes.

[0112] The ultraviolet treatment and the heat treatment may be carried out simultaneously, or the heat treatment may be carried out after the ultraviolet treatment. The temperature during the heat treatment is preferably 20 to 120°C, and more preferably 30 to 100°C.

[0113] The alignment film-forming material of the present invention is also preferably used for a liquid crystal display element (hereinafter also referred to as a PSA type liquid crystal display element) which comprises a pair of substrates each having an electrode and a liquid crystal layer therebetween, and which is manufactured through a process of disposing a liquid crystal composition between the pair of substrates, the liquid crystal composition containing a polymerizable compound which is polymerized by at least one of active energy rays and heat, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. The alignment film-forming material of the present invention may also be used for a liquid crystal display element (hereinafter also referred to as an SC-PVA mode type liquid crystal display element) which comprises a pair of substrates each having an electrode and a liquid crystal layer therebetween, and which is manufactured by disposing an alignment film between the pair of substrates, the alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat, and applying a voltage between the electrodes.

[0114] The liquid crystal element of the present invention is suitable for use in transportation equipment and machinery such as automobiles, trains, and aircraft, specifically, as an optical shutter element for light-controlling windows and rearview mirrors that control light transmission and blocking. In particular, due to its excellent transparency when no voltage is applied and its excellent scattering properties when voltage is applied, when the liquid crystal element is used in a vehicle's glass window, it can achieve higher light capture efficiency at night and better glare prevention than conventional reverse-type elements. This can further improve driving safety and passenger comfort. Furthermore, when the liquid crystal element is fabricated on a film substrate and attached to a vehicle's glass window, the reliability of the element is higher than that of conventional reverse-type elements. In other words, defects and degradation caused by poor adhesion between the liquid crystal layer and the vertical alignment film are less likely to occur. In addition, the liquid crystal element of the present invention can be used as a light guide plate for display devices such as LCDs (Liquid Crystal Displays) and OLEDs (Organic Light-emitting Diodes), or as a backing plate for transparent displays using these displays. Specifically, when used as a backing plate for a transparent display, the liquid crystal element of the present invention can be combined with the transparent display and used to suppress light from entering from the backside when a screen is displayed on the transparent display. As a result, the liquid crystal element enters a scattering state when a voltage is applied when a screen is displayed on the transparent display, thereby making the screen display clearer. After the screen display is finished, the liquid crystal element enters a transparent state when no voltage is applied. Furthermore, the alignment film-forming material of the present invention can be used as a liquid crystal alignment film for retardation films, liquid crystal alignment films for scanning antennas and liquid crystal array antennas, or for other applications such as protective films for color filters, gate insulating films for flexible displays, and substrate materials. [Example]

[0115] The present invention will be specifically described below with reference to examples, but the present invention should not be construed as being limited to these examples. The abbreviations of the compounds and the methods for measuring the respective properties are as follows.

[0116] (liquid crystal) L1: Sb-323010 (negative LCD, manufactured by Champagne) (polymerizable compound) R1: Isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., IBXA) R2: A compound component represented by the following formula [R2] (KAYARAD HX-220, manufactured by Nippon Kayaku Co., Ltd.; m and n are integers such that the sum of m and n is 2, and may be a mixture containing multiple compounds). R3: A compound component represented by the following formula [R3] (KAYARAD HX-620, manufactured by Nippon Kayaku Co., Ltd.; m' and n' are integers such that the sum of m' and n' is 4, and may be a mixture containing multiple compounds). R4: A compound component represented by the following formula [R4] (ethoxylated pentaerythritol tetraacrylate, NK Ester ATM-35E, manufactured by Shin-Nakamura Chemical Co., Ltd.; a, b, c, and d are integers such that the sum of a, b, c, and d is 35, and may be a mixture containing multiple compounds). R5: Pentaerythritol tetrakis(3-mercaptobutyrate) (Showa Denko K.K., Karenz MT PE1) R6: A compound represented by the following formula [R6] [ka] (Photoradical initiator) P1: 1-hydroxycyclohexyl phenyl ketone (IGM Resins, Omnirad 184)

[0117] (diamine) A1: 3,5-diaminobenzoic acid A2: 1,3-Diamino-4-{4-[trans-4-(trans-4-n-pentylcyclohexyl)cyclohexyl]phenoxy}benzene A3: 3,5-diaminobenzoic acid = 2-methacryloyloxyethyl (corresponding to the diamine having a terminal photopolymerizable group described above)

[0118] [ka]

[0119] (Tetracarboxylic acid dianhydride) B1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride B2: Bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride [ka] (amine compounds)

[0120] A4: 3-aminomethylpyridine [ka]

[0121] (additives) C1 to C3: Compounds represented by the following formulas (C1) to (C3) (specific adhesive compounds) (corresponding to component (B) of the present invention) D1 to D3: Compounds represented by the following formulas (D1) to (D3) (comparative compounds) [ka]

[0122] [ka]

[0123] (Methacrylic monomer) E1 to E3: Compounds represented by the following formulae (E1) to (E3): [ka]

[0124] (solvent) NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether CHN: Cyclohexanone PGME: Propylene glycol monomethyl ether DMSO: dimethyl sulfoxide MeCN: acetonitrile

[0125] "Molecular weight measurement of polyimide polymers" Measurement was carried out using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101, manufactured by Showa Denko KK) and columns (KD-803 and KD-805 in series, manufactured by Showa Denko KK) as follows. Column temperature: 50℃ Eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·HO) 30 mmol / L, phosphoric acid anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L) Flow rate: 1.0mL / min Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0126] "Measurement of imidization rate of polyimide polymers" 20 mg of polyimide powder was placed in an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (Kusano Scientific Co., Ltd.)), and 0.53 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05 wt% TMS (tetramethylsilane) mixture) was added. The solution was sonicated to completely dissolve it. Proton NMR at 500 MHz was measured using an NMR spectrometer (JNW-ECA500, JEOL Datum Co., Ltd.). The imidization ratio was calculated using the integrated peak value of this proton and the integrated peak value of the proton derived from the NH group of the amic acid, which appeared around 9.5 to 10.0 ppm, according to the following equation: Imidization rate (%) = (1 - α x / y) x 100 (x is the integrated value of the proton peak derived from the NH group of the amic acid, y is the integrated value of the peak of the reference proton, and α is the ratio of the number of reference protons to one NH group proton of the amic acid in the case of polyamic acid (imidization rate 0%).)

[0127] "Synthesis of additives C1 to C3" The compound represented by formula (C1) was synthesized by the synthesis method described in WO 2015 / 012341. Formulae (C2) to (C3) are novel compounds not previously disclosed in literature, and their synthesis methods are described in detail below.

[0128] <1 H-NMR Measurement Equipment: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (BRUKER) 500MHz. Solvent: deuterated dimethyl sulfoxide ([D6]-DMSO). Standard substance: tetramethylsilane (TMS).

[0129] <Additive Synthesis Example 1: Synthesis of [C2]> [ka]

[0130] A 200 mL four-neck flask was charged with 4'-[6-(2-methacryloyloxy)hexyloxy]biphenyl-4-carboxylic acid (19.1 g, 50 mmol), epichlorohydrin (23.1 g, 250 mmol), tetrabutylammonium chloride (2.1 g, 7.5 mmol), and DMSO (60 g) and stirred at 80 °C. After completion of the reaction, the reaction system was poured into ethyl acetate (300 g). The organic layer was washed with purified water (1000 g) and concentrated to obtain [C2-1] (23.7 g). [C2-1] was used directly in the next step without isolation or purification.

[0131] A 500 mL four-neck flask was charged with [C2-1] (23.7 g) obtained above, potassium carbonate (10.4 g, 75 mmol), dibutylhydroxytoluene (11.0 mg, 0.05 mmol), and MeCN (200 g), and the mixture was stirred at 80°C. After the reaction was completed, the precipitate was filtered off, and the filtrate was concentrated. The obtained crude product was isolated by silica gel column chromatography (chloroform:heptane = 4:1 (volume ratio)) to obtain [C2] (13.5 g, two-stage yield: 61%, white solid). 1 The results of H-NMR are shown below, and it was confirmed that the obtained solid was the desired [C2]. 1H-NMR(500MHz,[D6]-DMSO):δ(ppm)=8.02-8.03(d,2H),7.79-7.81(d,2H),7.69 -7.70(d,2H),7.04-7.05(d,2H),6.02(s,1H),5.67(s,1H),4.65-4.67(d,1H),4. 09-4.12(m,3H),4.01-4.04(m,2H),3.35-3.36(m,1H),2.85-2.86(m,1H),2.75-2 .76(m,1H),1.88(s,3H),1.73-1.76(m,2H),1.64-1.66(m,2H),1.41-1.48(m,4H)

[0132] <Additive synthesis example 2: Synthesis of [C3]> [ka]

[0133] A 200 mL four-neck flask was charged with 4-[trans-4-[[6-[(2-methyl-1-oxo-2-propen-1-yl)oxy]hexyl]oxy]cyclohexyl]benzoic acid (19.4 g, 50 mmol), epichlorohydrin (23.1 g, 250 mmol), tetrabutylammonium chloride (2.1 g, 7.5 mmol), and DMSO (60 g) and stirred at 80 °C. After completion of the reaction, the reaction mixture was poured into ethyl acetate (300 g). The organic layer was washed with purified water (1000 g) and concentrated to obtain [C3-1] (25.0 g). [C3-1] was used directly in the next step without isolation or purification.

[0134] A 500 mL four-neck flask was charged with [C3-1] (25.0 g) obtained above, potassium carbonate (10.4 g, 75 mmol), dibutylhydroxytoluene (11.0 mg, 0.05 mmol), and MeCN (250 g), and the mixture was stirred at 80°C. After the reaction was completed, the precipitate was filtered off, and the filtrate was concentrated. The obtained crude product was isolated by silica gel column chromatography (ethyl acetate:heptane = 1:5 (volume ratio)) to obtain [C3] (12.7 g, two-stage yield: 57%, pale yellow liquid solid). 1The results of H-NMR are shown below, and it was confirmed that the obtained solid was the desired [C3]. 1 H-NMR(500MHz,[D6]-DMSO):δ(ppm)=7.89-7.91(d,2H),7.39-7.40(d,2H),6.01-6.02(m,1H),5.6 7-5.68(m,1H),4.61-4.64(d,1H),4.06-4.10(m,3H),3.41-3.43(t,2H),3.31-3.34(m,1H),3.24- 3.28(m,1H),2.83-2.84(t,1H),2.72-2.73(m,1H),2.56-2.61(m,1H),2.05-2.09(m,2H),1.88(s, 3H),1.80-1.83(d,2H),1.59-1.65(m,2H),1.46-1.54(m,4H),1.33-1.35(m,4H),1.23-1.30(m,2H)

[0135] "Synthesis of polyimide polymers" <Synthesis Example 1> B2 (5.35 g, 21.4 mmol), A2 (3.72 g, 8.6 mmol), and A1 (3.04 g, 20.0 mmol) were mixed in NMP (36.3 g) and reacted at 80°C for 5 hours, after which B1 (1.28 g, 6.5 mmol) and NMP (3.86 g) were added and reacted at 40°C for 6 hours to obtain a polyamic acid solution with a resin solids concentration of 25.0 mass%. The resulting polyamic acid solution (20.0 g) was diluted to 6% by mass with NMP, and then acetic anhydride (4.50 g) and pyridine (3.30 g) were added as imidization catalysts and reacted at 90°C for 3 hours. The reaction solution was poured into methanol (400 mL), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (1). The imidization rate of this polyimide was 80%, and the number average molecular weight was 19,600 and the weight average molecular weight was 49,100. <Synthesis Example 2> B1 (3.30 g, 16.8 mmol), A2 (5.17 g, 11.9 mmol), and A3 (1.35 g, 5.1 mmol) were mixed in NMP (39.3 g) and reacted at 25°C for 24 hours to obtain a polyamic acid solution (2) with a resin solids concentration of 20.0 mass%. The polyamic acid solution (2) has a carboxy group, a structure represented by the above formula (S), and a photopolymerizable group. The carboxy group is derived from B1, the structure represented by the above formula (S) is derived from A2, and the photopolymerizable group is derived from A3. <Synthesis Example 3> B1 (3.30 g, 16.8 mmol), A2 (5.17 g, 11.9 mmol), and A1 (0.78 g, 5.1 mmol) were mixed in NMP (37.0 g) and reacted at 25°C for 24 hours to obtain a polyamic acid solution (3) with a resin solids concentration of 20.0 mass%. "Synthesis of methacrylic polymers" <Synthesis Example 4> E1 (2.44 g, 6.80 mmol), E2 (0.40 g, 1.70 mmol), and E3 (0.73 g, 8.50 mmol) were dissolved in CHN (21.0 g). The mixture was degassed using a diaphragm pump and the pressure was restored with nitrogen. Then, AIBN (0.14 g, 0.85 mmol) was added as a polymerization initiator, and the mixture was degassed again and the pressure was restored with nitrogen. The mixture was then reacted at 60°C for 13 hours to obtain a solution of methacrylic polymer (1).

[0136] "Production of alignment film forming materials" The following describes an example of the preparation of an alignment film-forming material, which is also used for the preparation and evaluation of a liquid crystal device.

[0137] Example 1 NMP (11.3 g) was added to the polyimide powder (1) (2.0 g) obtained in Synthesis Example 1, and the mixture was stirred at 70°C for 24 hours to dissolve the powder. A4 (2.0 g of a 5.0 mass% NMP solution) was added to this solution, and the mixture was stirred at 70°C for 15 hours to obtain a polyimide solution (1). Specific adhesion compound C1 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added to this polyimide solution, and the mixture was stirred at 25°C for 2 hours to obtain an alignment film-forming material (1). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Example 2> To the polyimide solution (1) (15.3 g) described in Example 1, specific adhesion compound C2 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added, and the mixture was stirred at 25° C. for 2 hours to obtain an alignment film-forming material (2). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed that it was a homogeneous solution. Example 3 To the polyimide solution (1) (15.3 g) described in Example 1, specific adhesion compound C3 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added, and the mixture was stirred at 25° C. for 2 hours to obtain an alignment film-forming material (3). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed that it was a homogeneous solution. Example 4 To the polyimide solution (1) (15.3 g) described in Example 1, specific adhesion compound C1 (0.2 g), D3 (0.2 g), NMP (9.3 g), and BCS (25.0 g) were added, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (4). This alignment film-forming material showed no abnormalities such as turbidity or precipitation, and was confirmed to be a homogeneous solution.

[0138] <Example 5> Specific adhesion compounds C1 (0.12 g), D3 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain an alignment film-forming material (5). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed that it was a homogeneous solution. Example 6 Specific adhesion compounds C2 (0.12 g), D3 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (6). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. Example 7 Specific adhesion compounds C3 (0.12 g), D3 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (7). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. Example 8 Specific adhesion compound C1 (0.2 g), D3 (0.1 g), NMP (14.7 g), and BCS (25.0 g) were added to polyamic acid solution (2) (10 g) obtained in Synthesis Example 2, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (8). This alignment film-forming material showed no abnormalities such as turbidity or precipitation, and was confirmed to be a homogeneous solution.

[0139] <Comparative Example 1> NMP (9.7 g) and BCS (25.0 g) were added to the polyimide solution (1) (15.3 g) described in Example 1, and the mixture was stirred at 25° C. for 2 hours to obtain an alignment film-forming material (9). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed that the solution was homogeneous. <Comparative Example 2> Comparative compound D1 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added to polyimide solution (1) (15.3 g) described in Example 1, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (10). This alignment film-forming material showed no abnormalities such as turbidity or precipitation, and was confirmed to be a homogeneous solution. <Comparative Example 3> Comparative compound D2 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added to polyimide solution (1) (15.3 g) described in Example 1, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (11). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Comparative Example 4> Comparative compound D3 (0.2 g), NMP (9.5 g), and BCS (25.0 g) were added to polyimide solution (1) (15.3 g) described in Example 1, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (12). This alignment film-forming material showed no abnormalities such as turbidity or precipitation, and was confirmed to be a homogeneous solution.

[0140] <Comparative Example 5> CHN (5.2 g) and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4 and stirred at room temperature to obtain an alignment film-forming material (13). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Comparative Example 6> Comparative compound D1 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (14). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Comparative Example 7> Comparative compound D2 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (15). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed that it was a homogeneous solution. <Comparative Example 8> Comparative compound D3 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (16). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Comparative Example 9> Comparative compounds D2 (0.12 g), D3 (0.12 g), CHN (5.2 g), and PGME (16.8 g) were added to the solution (8.0 g) of methacrylic polymer (1) obtained in Synthesis Example 4, and the mixture was stirred at room temperature to obtain alignment film-forming material (17). No abnormalities such as turbidity or precipitation were observed in this alignment film-forming material, and it was confirmed to be a homogeneous solution. <Comparative Example 10> Comparative compound D3 (0.1 g), NMP (14.9 g), and BCS (25.0 g) were added to polyamic acid solution (3) (10 g) obtained in Synthesis Example 3, and the mixture was stirred at 25° C. for 2 hours to obtain alignment film-forming material (18). This alignment film-forming material showed no abnormalities such as turbidity or precipitation, and was confirmed to be a homogeneous solution.

[0141] The compositions of the alignment film-forming materials obtained in the examples and comparative examples are shown in Table 1. The numbers in parentheses for the specific adhesive compound and the comparative compound indicate the content (parts by mass) relative to 100 parts by mass of the respective polymers. [Table 1]

[0142] <Preparation of light-controlling layer-forming material (A)> R1 (0.90 g), R2 (1.50 g), R3 (1.50 g), R4 (0.30 g), R5 (0.30 g), and R6 (0.50 g) were mixed and stirred at 25° C. for 6 hours to prepare a polymerizable compound solution. Then, the prepared polymerizable compound solution, L1 (4.0 g), and P1 (0.10 g) were mixed and stirred at 25° C. for 6 hours to obtain a light-controlling layer-forming material (A).

[0143] "Fabrication of liquid crystal elements and evaluation of their optical properties" The alignment film-forming material of the above Examples or Comparative Examples was pressure-filtered through a membrane filter with a pore size of 1 μm to prepare a liquid crystal device. Specifically, this alignment film-forming material was applied using a bar coater to the ITO surface of a PET (polyethylene terephthalate) substrate (length: 150 mm, width: 150 mm, thickness: 0.2 mm) with an ITO electrode that had been washed with pure water. The material was then heated on a hot plate at 100°C for 5 minutes and then at 120°C for 2 minutes in a heat-circulating clean oven to obtain an ITO substrate with an alignment film having a thickness of 100 nm. Two ITO substrates with the resulting alignment film were prepared, and a 6 μm-thick spacer was applied to the alignment film surface of one of the substrates. The above-mentioned dimming layer-forming material (A) was then dropped onto the spacer-coated alignment film surface of the substrate using the ODF method. The substrate was then bonded to the other substrate so that the alignment film interface faced each other, yielding a pre-processed liquid crystal device.

[0144] This untreated liquid crystal element was irradiated with ultraviolet light using an ultraviolet irradiation device with an ultraviolet light-emitting diode as the light source at a wavelength of 365 nm, an ultraviolet illuminance of 4 mW, and an irradiation time of 250 seconds. The temperature inside the irradiation device was controlled at 25°C. This resulted in a liquid crystal element (reverse type element).

[0145] "Evaluation of optical properties (transparency and scattering properties)" The transparency when no voltage was applied was evaluated by measuring the haze (cloudiness, also called HAZE) of the liquid crystal element when no voltage was applied. Specifically, the haze was measured using a BYK haze-gardi (manufactured by Tetsutani Co., Ltd.) measuring device. The evaluation was made such that the lower the haze, the better the evaluation, i.e., the transparency. The scattering characteristics when a voltage was applied were evaluated by applying 48V AC to the liquid crystal element and measuring the haze under the same conditions as above. The evaluation was based on the fact that the higher the haze, the better the scattering characteristics. The evaluation results of the optical properties are shown in Table 2.

[0146] "Evaluation of adhesion between liquid crystal layer and alignment film" The fabricated liquid crystal element was measured using a small tabletop testing machine EZ-SX manufactured by Shimadzu Corporation. The lower substrate was fixed to the stage, and then the edge of the upper substrate was fixed and the upper substrate was pulled upward to measure the peel strength (N / 25mm) at which the liquid crystal layer and the alignment film peeled off. The higher this value, the better the evaluation, i.e., the adhesion. The results of the adhesion evaluation are shown in Table 2. [Table 2]

[0147] As shown in Table 2, the examples using an alignment film-forming material containing polymer component (A) and a specific adhesion compound have improved adhesion between the liquid crystal layer and the alignment film and also have better optical properties than the comparative examples using an alignment film-forming material that does not contain either polymer component (A) or a specific adhesion compound. [Explanation of symbols]

[0148] 11 First base material 12, 16 Transparent electrode 13, 15 Liquid crystal alignment film 14 Photochromic Layer 17 Second base material 100 Liquid crystal element

[0149] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-005941 filed on January 18, 2021, and the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-096763 filed on June 9, 2021 are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

[Claim 1] A compound represented by the following formula (C2) or (C3): 【Chemistry 1】

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