Liquid crystal alignment agent, liquid crystal alignment film, and polymer-dispersed liquid crystal element

Abstract

The purpose of the present invention is to provide a liquid crystal alignment agent which enables the provision of a liquid crystal alignment film in which the adhesiveness between a polymer liquid crystal layer and a base material is high.　Provided is a liquid crystal alignment agent characterized by containing a component (A) mentioned below. Component (A): a polymer component (A) having a structure represented by formula (1) and a structure represented by formula (2). A polymer constituting the polymer component (A) comprises at least one polymer (A) selected from the group consisting of a polyimide precursor and a polyimide that is an imidized product of the polyimide precursor. [Formula 1] (In formula (1), the definition for each symbol is as described in the description.) [Formula 2] (In formula (2), the definition for each symbol is as described in the description.)

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal 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 a liquid crystal 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 the above applications, the ability to block the field of view in a light-scattering state is required. If the adhesion between the polymer liquid crystal layer and the substrate in a light-control element is low, the light scattering properties may change over time, and the function of blocking the field of view may be lost. Therefore, a liquid crystal 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 a liquid crystal alignment agent that provides a liquid crystal alignment film that has high adhesion between a polymer liquid crystal layer and a substrate, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a polymer-dispersed liquid crystal element that includes the liquid crystal alignment film. [Means for solving the problem]

[0008] As a result of intensive research to achieve the above object, the present inventors have found that a liquid crystal aligning agent having the following composition is effective for achieving the above object, and have completed the present invention.

[0009] The present invention is summarized as follows. A liquid crystal aligning agent characterized by containing the following component (A): Component (A): Polymer component (A) having a structure represented by the following formula (1) and a structure represented by the following formula (2), wherein the polymer constituting the polymer component (A) is at least one polymer (A) selected from the group consisting of polyimide precursors and polyimides which are imidized products thereof. [ka] (In formula (1), Y 1 and Y 7 are each independently a single bond, an alkylene group having 1 to 10 carbon atoms, -O-, -S-, -N(R 1 )-, -CON(R 2 )-, -N(R 3 )CO-, -CH2O-, -COO- or -OCO-. 1 , R 2 , R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Y 2 and Y 6 each independently represents an alkylene group having 1 to 10 carbon atoms; Y 3 and Y 5 each independently represents a hydrogen atom or a monovalent organic group; Y 4 represents an oxygen atom or a sulfur atom. * represents a bond. [ka] (In formula (2), Y 1 represents a single bond, -O-, -NH-, -N(CH3)-, -CHO-, -CONH-, -NHCO-, -CON(CH3)-, -N(CH3)CO-, -COO- or -OCO-. Y 3 represents a single bond, -O-, or the group *1-N(R) 2-m (-R'-*2) m (R represents an alkyl group having 1 to 6 carbon atoms, and R' represents an alkylene group having 1 to 6 carbon atoms. *1 and *2 represent bonds, and *1 represents Y 2 and *2 is Y 4 In the above group, m and m in formula (2) are integers of 1 or 2. When m is 1, Y 3 is one Y 4 and when m is 2, Y 3 is two Y 4 (bonded to).) represents -NH-, -N(CH3)-, -CHO-, -CONH-, -NHCO-, -CON(CH3)-, -N(CH3)CO-, -COO- or -OCO-. Y 2 represents a single bond, an alkylene group having 1 to 18 carbon atoms, or an organic group having 6 to 24 carbon atoms and at least one cyclic group selected from the group consisting of a benzene ring, a cyclocyclohexane ring, and a heterocycle, and 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. 2 is a single bond, Y 1 represents a single bond, and Y 3 represents the group "*1-N(-R'-*2)2". Y 4 represents any of the structures represented by the following formulas (2-a) to (2-g). * represents a bond. When m is 2, two Y 4 may be the same or different.)

[0010] [ka] (Y a represents a hydrogen atom or a benzene ring. b represents a single bond, a benzene ring, a cyclohexane ring or a heterocycle. c 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. * represents a bond.) [Effects of the Invention]

[0011] According to the present invention, it is possible to obtain a liquid crystal alignment agent that provides a liquid crystal alignment film that has high light transmittance in a transmitted state and high adhesion between a polymer liquid crystal layer and a substrate, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a polymer dispersed liquid crystal element that includes the liquid crystal 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 liquid crystal aligning agent of the present invention exhibits high adhesion because the photoreactive group incorporated in the liquid crystal aligning agent reacts with the liquid crystal. Furthermore, the photoreactive group and the structure represented by the above formula (1) have little effect of inhibiting alignment, so the liquid crystal alignment film maintains high liquid crystal alignment and exhibits high transmittance in the transmission state. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the liquid crystal aligning agent of the present invention, the liquid crystal alignment film obtained from the liquid crystal aligning agent, and the polymer dispersed liquid crystal element equipped with the liquid crystal alignment film will be described in detail. However, the explanation 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. * represents a bond.

[0013] <Polymer component (A)> The liquid crystal aligning agent of the present invention contains the following component (A) (polymer component (A)). Component (A): Polymer component (A) having a structure represented by the above formula (1) and a structure represented by the above formula (2), provided that the polymer constituting the polymer component (A) is at least one polymer (A) selected from the group consisting of polyimide precursors and polyimides, which are imidized products thereof. 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) containing at least one polymer (A-1) selected from the group consisting of polyimide precursors and polyimides, which are imidized products thereof, each of which has a structure represented by the above formula (1) and a structure represented by the above formula (2) in the same molecule, or (ii) At least one polymer (A-2) selected from the group consisting of polyimide precursors having a structure represented by the above formula (1) and polyimides that are imidized products thereof, and at least one polymer (A-3) selected from the group consisting of polyimide precursors having a structure represented by the above formula (2) and polyimides that are imidized products thereof. 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] Of these, from the viewpoint of more suitably obtaining the effects of the present invention, the polymer component (A) is preferably in the form (i). In the case of (i) above, the total of the repeating units having the structure represented by formula (1) above and the repeating units having the structure represented by formula (2) above is preferably 10 mol % or more, more preferably 15 mol % or more, and even more preferably 20 mol % or more of the repeating units constituting the polyimide precursor and its imidized product, the polyimide.

[0016] (Structure represented by formula (1)) In formula (1), Y 1 and Y 7 are each independently a single bond, an alkylene group having 1 to 10 carbon atoms, -O-, -S-, -N(R 1 )-, -CON(R 2 )-, -N(R 3 )CO-, -CH2O-, -COO- or -OCO-. 1 , R 2 and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Of these, a single bond, -O-, -S-, -COO-, or -OCO- is preferred, and a single bond, -O-, or -S- is more preferred from the viewpoint of obtaining the effects of the present invention favorably.

[0017] In formula (1), Y 2 and Y 6 are each independently an alkylene group having 1 to 10 carbon atoms. Among these, an alkylene group having 1 to 3 carbon atoms is preferred, and the structure may be either linear or branched. Specifically, from the viewpoint of obtaining the effects of the present invention favorably, a methylene group (-CH2-), an ethylene group (-CH2CH2-), a trimethylene group (-(CH2)3-), or an isopropylidene group (-C(CH3)2-) is preferred, which have a free rotation site and a structure with little steric hindrance. In formula (1), Y 3 and Y 5 each independently represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include a monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent group in which a functional group such as -O-, -COO-, -CO-, -NHCO-, -S-, or -NH- has been introduced between the carbon-carbon bonds of the hydrocarbon group, a monovalent aromatic heterocyclic group, and a protecting group that is eliminated by heating and replaced with a hydrogen atom (for example, a tert-butoxycarbonyl group). Of these, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred, with a hydrogen atom being particularly preferred. In formula (1), Y 4represents an oxygen atom or a sulfur atom. Of these, an oxygen atom is preferred from the viewpoint of obtaining the effects of the present invention favorably.

[0018] Preferred specific examples of the structure represented by formula (1) are structures represented by the following formulae (1-1) to (1-12). Among these, structures represented by formulae (1-1), (1-2), (1-4), (1-5), (1-7) and (1-8) are preferred. [ka]

[0019] (Structure represented by formula (2)) In the structure represented by the above formula (2), Y 1 is preferably a single bond, -O-, -CHO-, -CONH-, -CON(CH)- or -COO-, and more preferably a single bond, -O-, -CHO- or -COO- from the viewpoint of ease of synthesis. Y 2 is preferably an alkylene group having 2 to 12 carbon atoms, or an organic group having 6 to 24 carbon atoms and having at least one cyclic group selected from the group consisting of a benzene ring and a cyclohexane ring. 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. Y 2 From the viewpoint of ease of synthesis and achieving the effects of the present invention favorably, alkylene groups having 2 to 12 carbon atoms are more preferred.

[0020] Y 3 is preferably a single bond, —O—, a group —N(—R′-*2)2 (R and R′ are defined as in formula (2)), —NHCO—, —N(CH3)CO—, or —OCO—. From the viewpoint of ease of synthesis, a single bond, —O—, —NHCO—, or —OCO— is more preferred. Y 4is preferably the above formula (2-a), formula (2-b), formula (2-d), or formula (2-e). From the viewpoint of ease of synthesis and achieving the effects of the present invention well, formula (2-a), formula (2-b), or formula (2-e) is more preferred.

[0021] Preferred specific examples of the structure represented by formula (2) are structures represented by the following formulae (2-1) to (2-51). Among them, formulae (2-2) to (2-4), (2-6) to (2-8), (2-10) to (2-12), (2-14) to (2-16), (2-18) to (2-20), (2-22) to (2-24), (2-26) to (2-28), (2-30) to (2-32), (2-34) to (2-36), (2-38) to (2-40), (2-42) to (2-44), or (2-46) to (2-51) are preferred. In the structures represented by the following formulae (2-1) to (2-48) and (2-50) to (2-51), n ​​is more preferably 2 to 12. [ka] [ka] [ka] [ka] [ka]

[0022] (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.

[0023] (Origin of the structure represented by formula (1)) When the polyimide precursor (A) has a structure represented by formula (1), the structure represented by formula (1) may be a structure derived from a tetracarboxylic dianhydride having the structure represented by formula (1) or a derivative thereof, or may be a structure derived from a diamine having the structure represented by formula (1). Alternatively, the terminal of the polyimide precursor may have a structure represented by formula (1), and in this case, the structure represented by formula (1) may be a structure derived from a terminal modifier. The polyimide precursor (A) having the structure represented by formula (1) may be synthesized using a diamine having the structure represented by formula (1). As the diamine having the structure represented by formula (1), it is preferable to use, for example, a diamine represented by the following formula (d1) (also referred to as specific diamine (1)). [ka] In formula (d1), Y A represents an organic group having 10 to 50 carbon atoms and having the structure represented by the formula (1). 1 and A 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. More specifically, as the diamine having the structure represented by formula (1), it is preferable to use a diamine represented by the following formula (1a).

[0024] [ka] In formula (1a), Y 1 ~Y 7 has the same meaning as formula (1), including preferred embodiments. In formula (1a), A 1 and A 2 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0025] Specific examples of the specific diamine (1) include diamines represented by the following formulae (1a-1) to (1a-3). [ka] (In formulas (1a-1) to (1a-3), A 1 ~A 6 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). The specific diamine (1) in the polymer preferably accounts for 20 to 95 mol % of 100 mol % of the diamine component, more preferably 20 to 80 mol %, and even more preferably 20 to 70 mol %. The specific diamine (1) can be used alone or in combination of two or more depending on the solubility of the polymer (A) in a solvent, the coatability of the liquid crystal alignment agent, and the properties of the liquid crystal alignment film, such as the voltage holding ratio and the accumulated charge.

[0026] (Origin of the structure represented by formula (2)) When the polyimide precursor (A) has a structure represented by the above formula (2), the structure represented by formula (2) may be a structure derived from a tetracarboxylic dianhydride having the structure represented by formula (2) or a derivative thereof, or may be a structure derived from a diamine containing the structure represented by formula (2). Alternatively, the terminal of the polyimide precursor may have a structure represented by formula (2), and in this case, the structure represented by formula (2) may be a structure derived from a terminal modifier. The structure represented by formula (2) is more preferably derived from an aromatic diamine having the structure represented by formula (2) in its side chain (hereinafter also referred to as specific diamine (2)). The polyimide precursor (A) having the structure represented by the above formula (2) may be synthesized using the above specific diamine (2).

[0027] The specific diamine (2) preferably has at least one benzene ring. A specific example of the specific diamine (2) is a diamine represented by the following formula (2a). [ka] Y represents the structure represented by the above formula (2), and Y 1 ~Y 4 The definitions and preferred combinations of and m are as in formula (2) above. n represents an integer of 1 to 4, and is preferably 1. When there are multiple Ys, the multiple Ys may be the same or different. Specific examples include diamines represented by the following formulas (2a-1) to (2a-13). [ka] (In formulas (2a-1) to (2a-6), n1 is an integer of 2 to 12.) [ka] (In formulas (2a-8) to (2a-10), n1 is an integer of 1 to 12.) [ka] (In formulas (2a-11) to (2a-13), n1 is an integer of 2 to 12.)

[0028] In order to obtain the effects of the present invention, the specific diamine (2) in the polymer is preferably 5 to 80 mol % relative to 100 mol % of the diamine component, more preferably 5 to 70 mol %, and even more preferably 5 to 50 mol %.

[0029] As the diamine that can be used for synthesizing the polyimide precursor (A), diamines other than the specific diamine (1) and the specific diamine (2) (hereinafter also referred to as "other diamines") may be used. Examples of the other diamines include the following diamines.

[0030] Diamines represented by the following formula (O); diamines having a photoalignment group such as 4,4'-diaminoazobenzene or diaminotolane; diamines having an amide bond such as diamines represented by the following formulas (h-1) to (h-5); 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, and diamines represented by the following formula (dodiamines having at least one nitrogen atom-containing structure (hereinafter also referred to as specific nitrogen atom-containing structure) selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group, and a tertiary amino group (provided that the molecule does not contain an amino group bonded with a protecting group that is eliminated by heating and replaced with a hydrogen atom); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol; 4,4'-diamino-3,3'-dihydroxybiphenyl, 2 ,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, and diamines having a carboxy group such as diamines represented by the following formulas (3b-1) to (3b-4); 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 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; cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diamino diamines having a steroid skeleton such as 2,4-aminobenzoylaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestanyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulae (V-1) to (V-6); diamines having the group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom, preferably a tert-butoxycarbonyl group) such as those represented by the following formulae (5-1) to (5-11); 1,3- Diamines having a siloxane bond, such as bis(3-aminopropyl)tetramethyldisiloxane and diamines represented by the following formula (Ds-1): metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and diamines in which two amino groups are bonded to a group represented by any of formulas (Y-1) to (Y-167) described in WO 2018 / 117239.

[0031] [ka] (Ar represents a divalent benzene ring, biphenyl structure, or naphthalene ring. Two Ar may be the same or different, and any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring may be replaced with a monovalent substituent. p is an integer of 0 or 1. Q2 is -(CH2) n -(n is an integer of 2 to 18), or the -(CH2) n represents a group in which at least a portion of the -CH2- groups in - is replaced with either -O-, -C(=O)-, or -OC(=O)-.

[0032] [ka]

[0033] [ka] (Multiple m's may be the same or different.)

[0034] [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 4each 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.

[0035] [ka] (X v1 ~X v4 , X p1 ~X p2 are each independently -(CH2) a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CHO-, -CHOCO-, -COO-, or -OCO-; X v5 represents -O-, -CHO-, -CHOCO-, -COO-, or -OCO-. a represents a single bond, -O-, -NH-, -O-(CH2) m -O-, -C(CH3)2-, -CO-, -(CH2) m -, -SO2-, -OC(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -SO2-(CH2) m -, -CONH-(CH2) m -, -CONH-(CH2) m -NHCO-, -COO-(CH2) m -OCO-, -CONH-, -NH-(CH2) m -NH- or -SO2-(CH2) m -SO2- (wherein m is an integer of 1 to 6), R v1 ~R v4 , R 1a ~R 1b each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. Two k's may be the same or different. [ka] (Boc represents a tert-butoxycarbonyl group.) [ka]

[0036] The above formula (d o From the viewpoint of enhancing the liquid crystal alignment property, the diamine represented by the following formula (d o -1)~(d o Preferred are diamines represented by the formula (6), 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether. [ka]

[0037] In the diamine represented by the above formula (O), any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring may be replaced with a monovalent substituent. Examples of the monovalent substituent include a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, an alkyloxycarbonyl group having 1 to 10 carbon atoms, a cyano group, and a nitro group.

[0038] As the diamine represented by the above formula (O), from the viewpoint of enhancing the liquid crystal alignment property, a diamine represented by any one of the following formulae (o-1) to (o-16) is preferred.

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] Specific examples of diamines having the above-mentioned specific nitrogen atom-containing structure include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, diamines represented by the following formulae (Dp-1) to (Dp-8), diamines represented by the following formulae (z-1) to (z-13), and diamines having an oxazoline structure such as those represented by the following formulae (Ox-1) to (Ox-2). [ka] [ka] [ka]

[0043] [ka]

[0044] Examples of the tetracarboxylic acid component 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, it is more preferable to use a tetracarboxylic acid dianhydride or derivatives thereof 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. The tetracarboxylic dianhydride or a derivative thereof may have a structure represented by formula (1) or a structure represented by formula (2). The tetracarboxylic acid component that can be used in the synthesis of the polyimide precursor (A) is preferably a tetracarboxylic acid dianhydride represented by the following formula (T) or a derivative thereof. Examples of the derivative of the tetracarboxylic acid dianhydride include a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, and a tetracarboxylic acid dialkyl ester dihalide. The tetracarboxylic acid dianhydride or a derivative thereof may be used alone or in combination of two or more. [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.

[0045] More preferred specific examples of the above formula (x-1) include the following formulae (X1-1) to (X1-6).

[0046] [ka]

[0047] Preferred specific examples of the above formulae (x-12) and (x-13) include the following formulae (x-14) to (x-29). [ka] [ka]

[0048] 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.

[0049] Examples of the tetracarboxylic dianhydride having the structure represented by formula (1) or the structure represented by formula (2) or a derivative thereof include compounds represented by any of the following formulae (ts-1) to (ts-4) and (tv-1) to (tv-4). [ka] (In formulas (ts-3) and (ts-4), Boc represents a tert-butoxycarbonyl group.) [ka] (In formulas (tv-3) and (tv-4), two R, R' and m each independently have the above definition.)

[0050] 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.

[0051] <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.

[0052] (Synthesis of polyamic acid) The synthesis of the polyamic acid is carried out by reacting a diamine component containing the above diamine with a tetracarboxylic acid component containing the above tetracarboxylic dianhydride or a derivative thereof in an organic solvent.

[0053] 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. Furthermore, when the polymer has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, 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 can be used.

[0054] 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.

[0055] 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.

[0056] <Terminal Modifier> In synthesizing the polyimide precursor or polyimide of the present invention, a terminal-modified polymer may be synthesized using a tetracarboxylic acid component containing the above-mentioned tetracarboxylic acid dianhydride or its derivative, and a diamine component containing the above-mentioned diamine, together with an appropriate terminal modifier. The terminal-modified polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by coating and improving the adhesion properties between the sealant and the liquid crystal 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, the carboxy group, the acid anhydride group, or the isocyanate group can be obtained by a conventional condensation reaction or by blocking the terminals with the following terminal modifiers, and the derivatives can be obtained in the same manner, for example, by using the following terminal modifiers.

[0057] Examples of the terminal modifier include acid monoanhydrides 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; Examples of the isocyanate include diester dicarbonates such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride and nicotinic acid chloride; 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; monoisocyanate compounds such as isocyanates having an unsaturated bond, such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate; and isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate.

[0058] The proportion of the terminal modifier 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.

[0059] The molecular weight of the polyimide precursor and polyimide used in the present invention is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000, in terms of weight-average molecular weight (Mw) measured by Gel Permeation Chromatography (GPC), taking into consideration the strength of the resulting liquid crystal alignment film, workability during film formation, and coatability. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number-average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less. The solution viscosity of the polyimide precursor and polyimide, for example, when prepared as a 10% by mass solution, is preferably 10 to 800 mPa·s, 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 the polyimide precursor and polyimide (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0060] (liquid crystal alignment agent) The liquid crystal aligning agent of the present invention contains the above-mentioned polymer component (A) as an essential component, and is preferably prepared by dissolving and containing it in an organic solvent. The blending ratio of the polymer component (A) used in the liquid crystal aligning agent of the present invention is not particularly limited, but for example, the content of the polymer component (A) contained in the liquid crystal aligning agent is 0.1 to 30 mass %, preferably 1 to 10 mass %, based on the liquid crystal aligning agent. The liquid crystal aligning agent of the present invention is preferably used to form a liquid crystal alignment film, more preferably to form a liquid crystal alignment film for a polymer dispersed liquid crystal element.

[0061] The organic solvent contained in the liquid crystal aligning agent 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 lactam solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, etc.;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.

[0062] When the liquid crystal aligning agent of the present invention is applied to a plastic substrate or the like, the organic solvent used in the liquid crystal aligning agent may be composed of a solvent having a boiling point of 190° C. or less at 1 atmospheric pressure. Preferred solvent compositions when composed of a solvent having a boiling point of 190° C. or less at 1 atmospheric pressure 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 4-hydroxy-4-methyl-2-pentanone, cyclopentanone 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 liquid crystal alignment agent.

[0063] The liquid crystal aligning agent of the present invention contains the polymer component (A) as an essential component, 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), at least one crosslinking compound selected from the group consisting of a crosslinking compound (c-1) having at least one substituent selected from an epoxy group, an isocyanate group, an oxetane group, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group, and an alkoxy group, and a crosslinking compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, a compound for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film, a photoradical generator, a photoacid generator, a photobase generator, an ultraviolet absorber, and a light stabilizer.

[0064] The other polymer is not particularly limited, and examples thereof include polyimide precursors other than polymer component (A) and polyimides that are imidized products thereof (for example, at least one polymer selected from the group consisting of polyimide precursors that do not have either the structure represented by the above formula (1) or the structure represented by the above formula (2), and polyimides that are imidized products thereof), polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and the like. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, 2000, 3000 (manufactured by Cray Valley) and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.), a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAN-600 (manufactured by Kuraray Co., Ltd.), and a specific example of poly(vinyl ether-maleic anhydride) copolymers includes Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). 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 liquid crystal aligning agent.

[0065] 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.) When the crosslinkable compounds (c-1) and (c-2) are used, the total amount thereof 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 liquid crystal alignment agent.

[0066] Examples of compounds for adjusting the dielectric constant or electrical resistance include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. When using a monoamine having a nitrogen atom-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 liquid crystal aligning agent.

[0067] 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, 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 liquid crystal aligning agent.

[0068] 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 liquid crystal alignment film of the liquid crystal element.

[0069] 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 benzotriazole-based, triazine-based, and benzophenone-based ultraviolet absorbers. Of these, triazine-based ultraviolet absorbers are preferred.

[0070] 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.

[0071] The solid content of the liquid crystal aligning agent (the ratio of the total mass of the components other than the organic solvent in the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably in the range of 1 to 10 mass%. The preferred range of solid content varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solid content of 1.5 to 4.5 mass% is particularly preferred. When using a printing method, a solid content of 3 to 9 mass% is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solid content of 1 to 5 mass% is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s.

[0072] (Liquid crystal alignment film, liquid crystal element) The liquid crystal alignment film of the present invention is obtained from the liquid crystal aligning agent. The liquid crystal alignment film of the present invention can be used for horizontal alignment type or vertical alignment type liquid crystal alignment film, but is suitable for PDLC or PNLC type liquid crystal elements. The liquid crystal element of the present invention is provided with the liquid crystal alignment film.

[0073] 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. In any of the above liquid crystal elements, 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 liquid crystal 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.

[0074] (1) A step of applying a liquid crystal alignment agent to one or both of a pair of electrode-equipped substrates. The liquid crystal aligning agent 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, and poly(alicyclic olefin) 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, opaque substrates such as silicon wafers can be used for only one side of the substrate. In this case, light-reflecting materials such as aluminum can also be used for the electrodes. From the perspective of process simplification, it is preferable to use substrates formed with ITO (indium tin oxide) electrodes, IZO (indium zinc oxide) electrodes, IGZO (indium gallium zinc oxide) electrodes, organic conductive films, etc. for liquid crystal drive. (2) Baking the coating After applying the liquid crystal aligning agent, preliminary heating (pre-baking) is preferably performed first for the purpose of preventing dripping of the applied liquid crystal aligning agent. 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. A heating (post-baking) step may be further 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 thickness of the film thus formed is 1 to 1,000 nm, preferably 5 to 1,000 nm, and more preferably 10 to 1,000 nm.

[0075] The coating film formed in the above step (2) can be used as a liquid crystal 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.

[0076] 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.

[0077] (3) Step of placing a photochromic layer forming material A pair of electrode-equipped substrates, one or both of which have a liquid crystal 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 liquid crystal 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 to contact the film surface, and the injection hole is then sealed.

[0078] 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 a liquid crystal alignment film has been formed, and the above-mentioned dimming layer-forming material is then dropped onto several predetermined locations on the liquid crystal alignment film surface. The other substrate is then attached so that the liquid crystal 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.

[0079] 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.

[0080] (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.

[0081] (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. The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystal properties within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase. The liquid crystal composition may further contain additives to improve the liquid crystal alignment property, such as photopolymerizable monomers having a polymerizable group as described below, optically active compounds (e.g., S-811 manufactured by Merck Ltd.), antioxidants, ultraviolet absorbers, dyes, antifoaming agents, polymerization initiators, or polymerization inhibitors. Examples of the positive liquid crystal include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, and MLC-7081 manufactured by Merck. Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029 manufactured by Merck. In addition, in the PSA mode, MLC-3023 manufactured by Merck is an example of a liquid crystal containing a compound having a polymerizable group.

[0082] (Polymerizable compound component) In PDLC type liquid crystal elements and PNLC type liquid crystal elements, the material for forming the light control layer preferably contains a polymerizable compound component. As the polymerizable compound constituting the polymerizable compound component, it is preferable to use a radical polymerization type polymerizable compound (monomer) and its oligomer. It is also possible to use a polymer obtained by polymerizing these monomers. 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 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 alcohols 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. monofunctional (meth)acrylate compounds having a hydroxyl group; 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. 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), 2,2,3,3,4,4-hexafluoropentanediol-1,5-di(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 (for example, "NK Ester TMPT" manufactured by Shin-Nakamura Kogyo Co., Ltd.), pentaerythritol tri(meth)acrylate (for example, "NK Ester A-TMMT" manufactured by Shin-Nakamura Kogyo Co., Ltd.), pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetraacrylate (for example, "NK Ester A-TMMT" manufactured by Shin-Nakamura Kogyo Co., Ltd.), Examples of the (meth)acrylate compound 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.In addition to the compounds described above, monofunctional polymerizable compounds, bifunctional polymerizable compounds, and polyfunctional polymerizable compounds described on pages 58 to 60 of WO 2015 / 012368, or compounds described in paragraphs

[0195] to

[0205] of WO 2018 / 159302 can also be used.

[0083] The polymerizable compound may be an ionic polymerizable compound. Specific examples include melamine derivatives and benzoguanamine derivatives, 1,3,5-tris(methoxymethoxy)benzene, 1,2,4-tris(isopropoxymethoxy)benzene, 1,4-bis(sec-butoxymethoxy)benzene, and 2,6-dihydroxymethyl-p-tert-butylphenol, as described on pages 14 and 15 of International Publication No. 2014 / 171493 (published October 23, 2014), and compounds containing epoxy or isocyanate groups, as described on pages 15 and 16 of International Publication No. 2014 / 171493 (published October 23, 2014).

[0084] When an ionic polymerizable compound is used, an ionic initiator that generates an acid or a base when exposed to ultraviolet light can be introduced to promote the polymerization reaction. Specific examples of such an ionic initiator include those described on pages 16 and 17 of International Publication No. 2014 / 171493 (published October 23, 2014).

[0085] (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.

[0086] (Orientation additive) Examples of the alignment additive added to the light-controlling layer-forming material include the compounds described in

[0049] of JP-A-2019-065230. 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.

[0087] (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.

[0088] (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.

[0089] (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.

[0090] (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 irradiation intensity of ultraviolet light 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.

[0091] 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.

[0092] The liquid crystal aligning agent 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 is manufactured through a process of disposing a liquid crystal composition containing a polymerizable compound which is polymerized by at least one of active energy rays and heat between the pair of substrates, 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 liquid crystal aligning agent of the present invention may also be used in 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 a liquid crystal alignment film between the pair of substrates and containing a polymerizable group which is polymerized by at least one of active energy rays and heat, and applying a voltage between the electrodes.

[0093] 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 effects from external light 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 deterioration caused by poor adhesion between the liquid crystal layer and the liquid crystal 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 back when displaying a screen on the transparent display. As a result, the liquid crystal element enters a scattering state when a voltage is applied when displaying a screen on the transparent display, thereby making the screen display clearer. After the screen display has ended, the liquid crystal element enters a transparent state when no voltage is applied. Furthermore, the liquid crystal aligning agent 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]

[0094] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the physical properties are as follows:

[0095] (solvent) NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether (acid dianhydride) CA-1: A compound represented by the following formula (CA-1): (diamine) DA-1 to DA-4: Compounds represented by the following formulas (DA-1) to (DA-4), respectively [ka] (additives) s-1: 3-aminopropyltriethoxysilane (liquid crystal) L1: MLC-3018 (Merck) (polymerizable compound) R1: Isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., IBXA) R2: Polyethylene glycol #200 diacrylate (NK Ester A-200, manufactured by Shin-Nakamura Chemical Co., Ltd.) R3: A compound component represented by the following formula [R3] (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). R4: Pentaerythritol tetrakis(3-mercaptobutyrate) (Showa Denko K.K., Karenz MT PE1) [ka] (Photoradical initiator) P1: 1-hydroxycyclohexyl phenyl ketone (IGM Resins, Omnirad 184)

[0096] <Viscosity measurement> The viscosity of the solution was measured at 25°C using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24). <Molecular weight measurement> The molecular weight was measured using a room temperature GPC (gel permeation chromatography) device, and the number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalent values. GPC apparatus: GPC-101 (Showa Denko K.K.), columns: GPC KD-803 and GPC KD-805 (Showa Denko K.K.) in series, column temperature: 50°C, 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: 1.0 mL / 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.).

[0097] [Synthesis of polyamic acid] <Synthesis Example 1> DA-1 (2.01 g, 7.03 mmol), DA-2 (2.11 g, 14.1 mmol), DA-3 (4.20 g, 14.1 mmol), DA-4 (0.489 g, 1.85 mmol), and NMP (69.9 g) were added to a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube and dissolved by stirring at room temperature. CA-1 (6.82 g, 34.8 mmol) and NMP (17.5 g) were then added and stirred at room temperature for 16 h to obtain a 15% solution of polyamic acid (PAA-1) (viscosity: 227 mPa s). The Mn of this polyamic acid (PAA-1) was 7,928 and the Mw was 19,535.

[0098] <Synthesis Example 2> DA-1 (1.91 g, 6.66 mmol), DA-2 (2.00 g, 13.3 mmol), DA-3 (3.97 g, 13.3 mmol), DA-4 (0.978 g, 3.70 mmol), and NMP (70.1 g) were added to a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube and dissolved by stirring at room temperature. CA-1 (6.82 g, 34.8 mmol) and NMP (17.5 g) were then added and stirred at room temperature for 16 hours to obtain a 15% solution of polyamic acid (PAA-2) (viscosity: 227 mPa s). The Mn of this polyamic acid (PAA-2) was 8,338 and the Mw was 20,024.

[0099] <Synthesis Example 3> DA-1 (1.70 g, 5.92 mmol), DA-2 (1.78 g, 11.8 mmol), DA-3 (3.53 g, 11.8 mmol), DA-4 (1.96 g, 7.40 mmol), and NMP (70.6 g) were added to a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube and dissolved by stirring at room temperature. CA-1 (6.89 g, 35.1 mmol) and NMP (17.6 g) were then added and stirred at room temperature for 16 hours to obtain a 15% solution of polyamic acid (PAA-3) (viscosity: 186 mPa s). The Mn of this polyamic acid (PAA-3) was 8,313 and the Mw was 19,113.

[0100] <Synthesis Example 4> DA-1 (8.59 g, 30.0 mmol), DA-2 (9.01 g, 60.0 mmol), DA-3 (17.9 g, 60.0 mmol), DA-4 (26.4 g, 100 mmol), and NMP (496 g) were added to a 500 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube and dissolved by stirring at room temperature. CA-1 (48.5 g, 247 mmol) and NMP (124 g) were then added and stirred at 40 °C for 16 h to obtain a 15% solution of polyamic acid (PAA-4) (viscosity: 204 mPa s). The Mn and Mw of this polyamic acid (PAA-4) were 11,007 and 25,807, respectively.

[0101] <Synthesis Example 5> DA-1 (2.12 g, 7.40 mmol), DA-2 (2.22 g, 14.8 mmol), DA-3 (4.42 g, 14.8 mmol), and NMP (69.6 g) were added to a 100 mL four-neck flask equipped with a mechanical stirrer and a nitrogen inlet tube and dissolved by stirring at room temperature. CA-1 (6.60 g, 33.7 mmol) and NMP (17.4 g) were then added and stirred at room temperature for 16 hours to obtain a 15% solution of polyamic acid (PAA-5) (viscosity: 210 mPa s). The Mn of this polyamic acid (PAA-5) was 7,397 and the Mw was 19,724.

[0102] [Preparation of liquid crystal alignment agent] Example 1 NMP (34.8 g), BCS (30.0 g), and s-1 (1 mass% NMP solution, 7.20 g) were added to the solution (48.0 g) of polyamic acid (PAA-1) obtained in Synthesis Example 1, and the mixture was stirred at room temperature for 3 hours to obtain a liquid crystal alignment agent (AL-1).

[0103] <Examples 2 to 4, Comparative Example 1> Liquid crystal aligning agents (AL-2) to (AL-5) were obtained by carrying out the same operation as in Example 1, except that the type of polyamic acid used was changed as shown in Table 1. [Table 1]

[0104] [Preparation of Liquid Crystal Composition] <Preparation of liquid crystal composition (positive type / normal type)> R1 (1.5 g), R2 (1.5 g), R3 (1.5 g), and R4 (0.5 g) were mixed and stirred at 25° C. for 6 hours to prepare a polymerizable compound solution. Then, the prepared polymerizable compound solution (5.0 g), P1 (0.25 g), L1 (7.0 g), and 7.5 μm bead spacers (0.04 g) were mixed and stirred at 25° C. for 8 hours to obtain liquid crystal composition (1).

[0105] [Preparation of LCD device for adhesion evaluation] First, two glass substrates with ITO electrodes on the entire surface were prepared for each type of liquid crystal alignment agent. The substrates were 30 mm x 40 mm and 1.1 mm thick, and a 35 nm thick ITO electrode was formed on the entire surface of the substrate. Next, the liquid crystal alignment agents (AL-1) to (AL-5) obtained above were filtered through a 1.0 μm pore size filter and then spin-coated onto the ITO surface of the prepared electrode-attached substrate. The resulting coating was dried on a hot plate at 80 °C for 2 minutes and then baked in an infrared oven at 230 °C for 20 minutes to form a 100 nm thick coating film, yielding a polyimide film. The polyimide film was then rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, indentation depth: 0.4 mm), followed by ultrasonic cleaning in pure water for 1 minute, water droplets removed by air blowing, and dried at 80 °C for 10 minutes to obtain a substrate with a liquid crystal alignment film. At this time, the rubbing treatment was carried out so that the rubbing direction was in the short side direction of one ITO substrate and in the long side direction of the other. The short side of this ITO substrate with a liquid crystal alignment film was cut so as to divide the substrate into two, obtaining two sets of ITO substrates with a liquid crystal alignment film measuring 15 mm x 40 mm. The liquid crystal composition (1) described above was dropped onto the surface of the liquid crystal alignment film of the substrate that had been rubbed in the short side direction, and then the substrates that had been rubbed in the long side direction were bonded together so that the liquid crystal alignment film interfaces of the substrates facing each other and the rubbing directions were in opposite directions (i.e., the substrates were perpendicular to each other), thereby obtaining a liquid crystal display element before treatment. This liquid crystal display element before treatment was subjected to illuminance of 4 mW / cm. 2 The liquid crystal cell was irradiated with ultraviolet light equivalent to 1000 mJ for 250 seconds using an LED light. The temperature inside the irradiation device was controlled at 25°C while irradiating the liquid crystal cell with ultraviolet light. In this way, a liquid crystal display element for evaluating adhesion was obtained. All of the liquid crystal display elements equipped with liquid crystal alignment films obtained from the liquid crystal alignment agents (AL-1) to (AL-5) of Examples 1 to 4 and Comparative Example 1 exhibited uniform liquid crystal alignment. In Comparative Example 2, a liquid crystal display element was produced in the same manner as above, without using a liquid crystal alignment agent.

[0106] [Adhesion evaluation] Adhesion evaluation was performed using a desktop precision universal testing machine (AGS-X 500N) (Shimadzu Corporation). Specifically, after fixing the edges of the upper and lower substrates of the obtained cell, the overlapping portion of both substrates was pressed from above at a speed of 5 mm per second, and the pressure (mN) during peeling was measured. The evaluation was based on the fact that the higher the peel strength value, the better the adhesion, i.e., the better the evaluation. The results are shown in Table 2. [Table 2] As shown in Table 2, the examples using a liquid crystal alignment agent containing a polyamic acid having a structure represented by formula (1) and a structure represented by formula (2) have better adhesion than the comparative examples using a liquid crystal alignment agent that does not contain it.

[0107] In addition, the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-022822, filed on February 16, 2021, are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent comprising the following component (A): Component (A): Polymer component (A) having a structure represented by the following formula (1) and a structure represented by the following formula (2), wherein the polymer constituting the polymer component (A) is at least one polymer (A) selected from the group consisting of polyimide precursors and polyimides that are imidized products thereof. 【Chemistry 1】 (In formula (1), Y １ and Y ７ are each independently a single bond, an alkylene group having 1 to 10 carbon atoms, —O—, —S—, —N(R １ ) -, -CON(R ２ ) -, -N(R ３ )CO—, —CH ２ represents -O-, -COO- or -OCO-. １ , R ２ , R ３ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Y ２ and Y ６ each independently represents an alkylene group having 1 to 10 carbon atoms; Y ３ and Y ５ each independently represents a hydrogen atom or a monovalent organic group; Y ４ represents an oxygen atom or a sulfur atom. * represents a bond. 【Chemistry 2】 (In formula (2), Y １ is -NH-, -N(CH ３ ) -, -CH ２ O-, -CONH-, -NHCO-, -CON(CH ３ ) -, -N(CH ３ ) represents CO—, —COO— or —OCO—. Y ３ represents a single bond, —O—, a group “*1-N(R) ２－ｍ (-R'-*2) ｍ (R represents an alkyl group having 1 to 6 carbon atoms, and R' represents an alkylene group having 1 to 6 carbon atoms. *1 and *2 represent bonds, and *1 represents Y ２ and *2 is Y ４ In the above group, m and m in formula (2) are integers of 1 or 2. When m is 1, Y ３ is one Y ４ and when m is 2, Y ３ is two Y ４ bonded to.)), -NH-, -N(CH ３ ) -, -CH ２ O-, -CONH-, -NHCO-, -CON(CH ３ ) -, -N(CH ３ ) represents CO—, —COO— or —OCO—. Y ２ represents a single bond, an alkylene group having 2 to 18 carbon atoms, or an organic group having 6 to 24 carbon atoms and at least one cyclic group selected from the group consisting of a benzene ring, a cyclocyclohexane ring, and a heterocycle, and 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. ２ is a single bond, Y １ represents a single bond, and Y ３ represents the group *1-N(-R''-*2) 2 , where R'' represents an alkylene group having 2 to 6 carbon atoms. Y ４ represents any of the structures represented by the following formulas (2-a) to (2-g). * represents a bond. When m is 2, two Y ４ may be the same or different.) 【Transformation 3】 (Y ａ represents a hydrogen atom or a benzene ring. ｂ represents a single bond, a benzene ring, a cyclohexane ring or a heterocycle. ｃ 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. * represents a bond.)

2. The polymer component (A) has a structure represented by the formula (1) and a structure represented by the formula (2) in the same molecule, and is selected from the group consisting of a polyimide precursor and a polyimide that is an imidized product thereof. The liquid crystal aligning agent according to claim 1, comprising at least one polymer (A-1).

3. The liquid crystal aligning agent according to any one of claims 1 to 2, wherein the structure represented by the formula (1) is a structure represented by any one of the following formulas (1-1) to (1-12): 【Chemistry 4】 (* represents a bond.)

4. The structure represented by the formula (2) is a structure represented by any one of the following formulas (2-25) to (2-48), (2-51), the liquid crystal aligning agent according to any one of claims 1 to 3. 【Transformation 5】 【Transformation 6】

5. When the polyimide precursor has a structure represented by formula (1), the structure represented by formula (1) possessed by the polyimide precursor is derived from a diamine represented by the following formula (d1): The liquid crystal aligning agent according to any one of claims 1 to 4. 【Transformation 7】 (In formula (d1), Y Ａ represents an organic group having 10 to 50 carbon atoms and having the structure represented by the formula (1). １ and A ２ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

6. The liquid crystal aligning agent according to claim 5, wherein the diamine represented by the formula (d1) is a diamine represented by the following formula (1a): 【Transformation 8】 (In formula (1a), Y １ ~Y ７ is the same as formula (1), and A １ and A ２ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

7. The polyimide precursor is obtained using a diamine component containing the diamine represented by the formula (d1), and the content of the diamine represented by the formula (d1) is 20 to 95 mol% in 100 mol% of the diamine component. The liquid crystal aligning agent according to claim 5 or 6.

8. When the polyimide precursor has a structure represented by the formula (2), the structure represented by the formula (2) possessed by the polyimide precursor is derived from an aromatic diamine having the structure represented by the formula (2) in a side chain. The liquid crystal aligning agent according to any one of claims 1 to 7.

9. The liquid crystal aligning agent according to claim 8, wherein the aromatic diamine having the structure represented by formula (2) in a side chain is derived from a diamine represented by the following formula (2a): 【Chemistry 9】 (Y represents a structure represented by the above formula (2), and n represents an integer of 1 to 4. When there are multiple Ys, the multiple Ys may be the same or different.)

10. The polyimide precursor is obtained using a diamine component containing an aromatic diamine having a structure represented by the formula (2) in a side chain, and the content of the aromatic diamine having a structure represented by the formula (2) in a side chain is 5 to 80 mol% in 100 mol% of the diamine component. The liquid crystal aligning agent according to claim 8 or 9.

11. The liquid crystal aligning agent according to any one of claims 1 to 10, wherein the polyimide precursor is obtained using a tetracarboxylic dianhydride represented by the following formula (T) or a derivative thereof: 【Chemistry 10】 (X represents a structure selected from any of the following formulas (x-1) to (x-13).) 【Chemistry 11】 (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; A １ and A ２ each independently represents 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), ２ may be the same or different.)

12. The liquid crystal aligning agent according to any one of claims 1 to 11, which is used to form a liquid crystal alignment film of a polymer dispersed liquid crystal element.

13. The liquid crystal aligning agent according to any one of claims 1 to 12, further comprising at least one additive selected from the group consisting of a crosslinkable compound, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, a compound for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film, a photoradical generator, a photoacid generator, a photobase generator, an ultraviolet absorber and a light stabilizer.

14. A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of claims 1 to 13.

15. A liquid crystal device comprising the liquid crystal alignment film according to claim 14.

16. A polymer dispersed liquid crystal element comprising the liquid crystal alignment film according to claim 15.

17. A method for producing a polymer dispersed liquid crystal element, comprising the following steps (1) to (4): (1) A step of applying the liquid crystal aligning agent according to any one of claims 1 to 13 to one or both of a pair of electrode-attached substrates. (2) A step of baking the coating film formed on the substrate in (1) above. (3) Step of disposing a light-controlling layer-forming material (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.

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