Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

Abstract

This disclosure relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element with good reliability and low liquid crystal contact angle. The liquid crystal alignment agent comprises: a polymer (A), including a first polymer (A1), which is obtained by reacting a first mixture containing a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamide polymers, polyimide polymers, polyimide-based block copolymers, or combinations thereof; a polysiloxane (B), obtained by reacting an isocyanate-containing polysiloxane (b1) with a compound (b2), wherein the isocyanate-containing polysiloxane (b1) is obtained by polycondensation of a third mixture; and a solvent (C).

Description

Technical Field

[0001] This disclosure relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element, particularly to a liquid crystal alignment agent with good reliability and a low liquid crystal contact angle, a liquid crystal alignment film formed from the above liquid crystal alignment agent, and a liquid crystal display element having the above liquid crystal alignment film. Prior Technology

[0002] Generally, various driving methods have been developed for liquid crystal display (LCD) elements, depending on the electrode structure or the physical properties of the liquid crystal molecules used. Currently known driving methods for LCD elements include: TN or STN type, VA type, and lateral electric field effect (IPS) display technology. These LCD elements are equipped with a liquid crystal alignment film to align the liquid crystal molecules. The material of the liquid crystal alignment film can be, for example, known materials such as polyimide or polyimide, polyester, and polyorganosiloxane.

[0003] In recent years, in order to control the alignment of liquid crystal molecules in liquid crystal display elements, new technologies such as polymer-stable alignment (PSA) have been proposed. For example, Japanese Patent Application Publication No. JP 2003-149647 describes a polymer-stable alignment technology that adds a component with photopolymerizable properties to the liquid crystal layer of a liquid crystal cell, tilts the liquid crystal molecules under an applied voltage, and then irradiates the liquid crystal cell with light, thereby causing the photopolymerizable component to polymerize, thereby controlling the alignment of the liquid crystal molecules.

[0004] However, when using polymer-stabilized alignment technology to control the alignment of liquid crystal molecules, a relatively high amount of light irradiation is required, which leads to defects such as liquid crystal molecule decomposition and deterioration of the properties of the liquid crystal alignment film, resulting in non-uniformity of the display element and deterioration of the panel's durability. On the other hand, if the aforementioned amount of light irradiation is reduced, the response speed of the liquid crystal molecules in the formed liquid crystal display element to voltage changes becomes slower. In order to achieve the predetermined pretilt angle characteristics of the liquid crystal alignment agent used to form the coating with as little light irradiation as possible, and to make the liquid crystal molecules in the formed liquid crystal display element respond quickly to voltage, Japanese Patent Publication No. 2011-118358 discloses the use of a liquid crystal alignment agent containing a polyorganosiloxane such as (meth)acrylic acid and a photopolymerizable component such as poly(meth)acrylic acid or poly(meth)amine to form a liquid crystal alignment film on a substrate. Then, liquid crystal cells are formed on the above substrate, and when a voltage is applied between the substrates, the liquid crystal cells are irradiated with light to obtain a liquid crystal display element.

[0005] However, the reliability and liquid crystal contact angle of the aforementioned liquid crystal alignment agents still need improvement. Therefore, there is an urgent need to propose a liquid crystal alignment agent that has advantages such as good reliability and low liquid crystal contact angle. Summary of the Invention

[0006] This invention discloses a liquid crystal alignment agent obtained by providing a special composition, which has the advantages of good reliability and low liquid crystal contact angle.

[0007] This disclosure provides a liquid crystal alignment agent comprising: Polymer (A) comprises a first polymer (A1) obtained by reacting a first mixture, the first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamide polymers, polyimide polymers, polyimide-based block copolymers, or combinations thereof; Polysiloxane (B) is prepared by reacting isocyanate-containing polysiloxane (b1) with compound (b2), wherein the isocyanate-containing polysiloxane (b1) is obtained by polycondensation of a third mixture; and Solvent (C); The compound (b2) comprises a structure of formula (V): Formula (V) In formula (V): E1 is an alkyl group with 1 to 30 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms substituted or unsubstituted with an alkyl or alkoxy group with 1 to 20 carbon atoms, or a hydrocarbon group with 17 to 51 carbon atoms containing a steroid skeleton. Some of the hydrogen atoms in the alkyl and alkoxy groups of E1 are substituted or unsubstituted. L0 represents a single bond, *1-O-, *1-COO-, or *1-OCO-, where *1 represents the bond with E1; L1 is a single bond, and is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group of formula (V-1) or formula (V-2) with 1 to 20 carbon atoms: Equation (V-1) Equation (V-2) Where *2 represents the bond with Z; and when L1 is a single bond, L0 is a single bond, and Z is a monovalent organic group that reacts with the isocyanate group to form a binding group.

[0008] In some embodiments, the third mixture comprises a silane monomer (b1-1) as shown in formula (VI-1): Si(R a) c(OR b) 4-c formula (VI-1) In formula (VI-1): Ra represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an isocyanate group having 1 to 10 carbon atoms, and at least one Ra contains an isocyanate group having 1 to 10 carbon atoms; when Ra is plural, the Ra groups may be the same or different; Rb represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an amide group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; when Rb is plural, the Rb groups may be the same or different; and c represents an integer from 1 to 3.

[0009] In some embodiments, the silane monomer (b1-1) comprises 3-Isocyanato propyl triethoxy silane or 3-Isocyanato propyl diethoxy methyl silane.

[0010] In some embodiments, the diamine component (a2) comprises the diamine compound (a2-1) shown in formula (II). Equation (II) In formula (II): R 15 indicates free choice , , , , and The group that it forms; and R 16 represents the organic group shown in formula (II-1): Equation (II-1) in: R 17 indicates hydrogen, fluorine, or methyl; R18, R19, and R20 each independently represent a single bond. , , , , , Or alkyl groups having 1 to 3 carbon atoms; R 21 series selection freedom and The group that it forms; in: R 23 and R 24 each independently represent hydrogen, fluorine, or methyl; R 22 is selected from the group consisting of hydrogen, fluorine, alkyl groups having 1 to 12 carbon atoms, fluoroalkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, -OCH 2F, -OCHF 2 and -OCF 3; a represents an integer of 1 or 2; g, m, and i each independently represent integers from 0 to 4; y, h, and x each independently represent integers from 0 to 3, and y + h + x ≥ 2; and z1 and z2 each independently represent 1 or 2; When there are multiple R17, R18, R19, R20, R21, R23 or R24, they can be the same or different.

[0011] In some embodiments, based on the total amount of silane monomer in the third mixture being 1 mol, the amount of silane monomer (b1-1) used is 0.6 mol to 1 mol, and the amount of compound (b2) used is 0.05 mol to 0.5 mol.

[0012] In some embodiments, the amount of polymer (A) used is 100 parts by weight, the amount of polysiloxane (B) used is 1 to 30 parts by weight, and the amount of solvent (C) used is 500 to 3000 parts by weight.

[0013] In some embodiments, the amide content of the polymer (A) is 30% to 80%.

[0014] This disclosure also provides a liquid crystal alignment film formed from the liquid crystal alignment agent.

[0015] This disclosure also provides a liquid crystal display element, which includes the liquid crystal alignment film. Implementation

[0016] This disclosure provides a liquid crystal alignment agent comprising: Polymer (A) comprises a first polymer (A1) obtained by reacting a first mixture, the first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamide polymers, polyimide polymers, polyimide-based block copolymers, or combinations thereof; Polysiloxane (B) is prepared by reacting isocyanate-containing polysiloxane (b1) with compound (b2), wherein the isocyanate-containing polysiloxane (b1) is obtained by polycondensation of a third mixture; and Solvent (C); The compound (b2) comprises a structure of formula (V): Formula (V) In formula (V): E1 is an alkyl group with 1 to 30 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms substituted or unsubstituted with an alkyl or alkoxy group with 1 to 20 carbon atoms, or a hydrocarbon group with 17 to 51 carbon atoms containing a steroid skeleton. Some of the hydrogen atoms in the alkyl and alkoxy groups of E1 are substituted or unsubstituted. L0 represents a single bond, *1-O-, *1-COO-, or *1-OCO-, where *1 represents the bond with E1; L1 is a single bond, and is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group of formula (V-1) or formula (V-2) with 1 to 20 carbon atoms: Equation (V-1) Equation (V-2) Where *2 represents the bond with Z; and when L1 is a single bond, L0 is a single bond, and Z is a monovalent organic group that reacts with the isocyanate group to form a binding group.

[0017] The following is an overview of the components of the liquid crystal alignment agent disclosed herein. [polymer] [(A)] [First Polymer] [(A1)]

[0018] According to the present disclosure, polymer (A) comprises a first polymer (A1), which is prepared by reacting a first mixture. The first mixture comprises a tetracarboxylic dianhydride component (a1) and a diamine component (a2). Specifically, the first polymer (A1) is selected from the group consisting of polyamide polymers, polyimide polymers, polyimide block copolymers, and any combination thereof. Preferably, the first polymer (A1) is a polyimide polymer.

[0019] The tetracarboxylic dianhydride compound (a1) includes at least one of aliphatic tetracarboxylic dianhydride compounds, alicyclic tetracarboxylic dianhydride compounds, aromatic tetracarboxylic dianhydride compounds, tetracarboxylic dianhydride compounds represented by formulas (I-1) to (I-6), or a combination of the above compounds.

[0020] The following are specific examples of aliphatic tetracarboxylic dianhydride compounds, alicyclic tetracarboxylic dianhydride compounds, and aromatic tetracarboxylic dianhydride compounds, but this disclosure is not limited to these specific examples.

[0021] Specific examples of aliphatic tetracarboxylic dianhydrides may include, but are not limited to, ethane tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, or combinations thereof.

[0022] Specific examples of alicyclic tetracarboxylic dianhydrides may include, but are not limited to, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloheptyl-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, or combinations thereof.

[0023] Specific examples of aromatic tetracarboxylic dianhydrides may include, but are not limited to, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic dianhydride, benzopyrene tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenylene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenylethane tetracarboxylic dianhydride, 3,3' 4,4'-Dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-Tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-Furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride dianhydride), 3,3',4,4'-perfluoroisopropylidene dianhydride, 3,3',4,4'-diphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-extrin-phenyl-bis(triphenylphthalic acid) dianhydride, m-extrin-phenyl-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis(dehydrated trimellitate) ), propylene glycol-bis(dehydrated trimellitate), 1,4-butanediol-bis(dehydrated trimellitate), 1,6-hexanediol-bis(dehydrated trimellitate), 1,8-octanediol-bis(dehydrated trimellitate), 2,2-bis(4-hydroxyphenyl)propane-bis(dehydrated trimellitate), 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-disideoxy-3-furanyl)-naphtho[1,2] -c]-furan-1,3-dione{(1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione)}, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan-1 3-Diketone, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-diketone, 1,3,3a,4,5,9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-diketone, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,3 ...5-Di(di-side-oxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-di-side-oxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-di-side-oxy-3-furanyl)-naphtho [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 5-(2,5-dioxytetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, and other aromatic tetracarboxylic acid dianhydrides, or combinations thereof.

[0024] The tetracarboxylic acid dianhydride compounds represented by formulas (I-1) to (I-6) are shown below: Formula (I-1) Formula (I-2) Formula (I-3) Formula (I-4) Formula (I-5) Formula (I-6).

[0025] In formula (I-5), A1 represents a divalent group containing an aromatic ring; r represents an integer from 1 to 2; A2 and A3 may be the same or different, and may each independently represent a hydrogen atom or an alkyl group. Specific examples of tetracarboxylic dianhydride compounds represented by formula (I-5) include at least one of the compounds represented by formulas (I-5-1) to (I-5-3): Formula (I-5-1) Formula (I-5-2) Formula (I-5-3).

[0026] In formula (I-6), A4 represents a divalent group containing an aromatic ring; A5 and A6 may be the same or different, and each independently represents a hydrogen atom or an alkyl group. The tetracarboxylic dianhydride compound represented by formula (I-6) is preferably the compound represented by formula (I-6-1): Formula (I-6-1).

[0027] The aforementioned tetracarboxylic acid dianhydride compounds can be used alone or in combination.

[0028] Preferred examples of the tetracarboxylic dianhydride component (a1) include 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, compounds represented by formula (I-1), or combinations of the above compounds.

[0029] Based on a total mole count of 100 moles for the diamine component (a2), the preferred usage range for the tetracarboxylic acid dianhydride component (a1) is 80 to 120 moles, more preferably 85 to 115 moles.

[0030] The diamine component (a2) disclosed herein includes the diamine compound (a2-1) represented by formula (II): Equation (II) In formula (II): R 15 indicates free choice , , , , and The group that it forms; and Equation (II-1) in: R 17 indicates hydrogen, fluorine, or methyl; R18, R19, and R20 each independently represent a single bond. , , , , , Or alkyl groups having 1 to 3 carbon atoms; R 21 series selection freedom and The group that it forms; in: R 23 and R 24 each independently represent hydrogen, fluorine, or methyl; R 22 is selected from the group consisting of hydrogen, fluorine, alkyl groups having 1 to 12 carbon atoms, fluoroalkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, -OCH 2F, -OCHF 2 and -OCF 3; a represents an integer of 1 or 2; g, m, and i each independently represent integers from 0 to 4; y, h, and x each independently represent integers from 0 to 3, and y + h + x ≥ 2; and z1 and z2 each independently represent 1 or 2; When there are multiple R17, R18, R19, R20, R21, R23 or R24, they can be the same or different.

[0031] Specific examples of the diamine compound (a2-1) include at least one of the diamine compounds represented by formulas (II-2) to (II-10), or a combination of the above compounds. Equation (II-2) Equation (II-3) Equation (II-4) Equation (II-5) Equation (II-6) Equation (II-7) Equation (II-8) Equation (II-9) Formula (II-10).

[0032] In formulas (II-2) to (II-10), B 11 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0033] The diamine compounds represented by formulas (II-2) to (II-9) are preferably at least one of the diamine compounds represented by formulas (II-11) to (II-17), or a combination of the above compounds. Equation (II-11) Equation (II-12) Equation (II-13) Equation (II-14) Equation (II-15) Equation (II-16) Equation (II-17).

[0034] The aforementioned diamine compound (a2-1) can be used alone or in combination.

[0035] In the specific example disclosed herein, based on the total amount of diamine component (a2) used being 100 moles, the amount of diamine compound (a2-1) used is 5 to 60 moles, preferably 8 to 50 moles, and more preferably 10 to 40 moles. If the amount of diamine compound (a2-1) used falls within the aforementioned range, the liquid crystal alignment agent has a lower liquid crystal contact angle.

[0036] Preferably, the diamine component (a2) disclosed herein may further comprise other diamine compounds (a2-2).

[0037] The other diamine compound (a2-2) may include, but is not limited to, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 4,4'-diaminoheptane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, and 1,7-diamino-2,5-dimethylheptane. 1,7-Diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylnonane, 2,11-diaminododecane, 1,12-diaminooctadecane, 1,2-bis(3-aminopropoxy)ethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylamine, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene diamine, tricyclic (6.2.1).0 2,7)-Undecenedimethyldiamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylamine, 4,4'-diaminobenzylaniline, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, hexahydro-4,7-methyl-indenedimethyldiamine, 3,3'-diaminobenzophenone, 3,4' -Diaminobenzophenone, 4,4'-Diaminobenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenoxy)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl], 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroanthracene, 9,10-bis(4-aminophenyl)anthracene [9,10-bis(4-aminophenyl)] [anthracene], 2,7-diaminobenzene, 9,9-bis(4-aminophenyl)benzene, 4,4'-methylene-bis(2-chloroaniline), 4,4'-(p-epylphenylisopropylidene)bisaniline, 4,4'-(m-epylphenylisopropylidene)bisaniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene{5-[4-(4-n-pentylcyclohexyl)cyclohexyl] phenylmethylene-1,3-diaminobenzene, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane, or other diamine compounds as shown in formulas (III-1) to (III-24).

[0038] The diamine compounds represented by formula (III-1) are shown below: Equation (III-1).

[0039] In equation (III-1), X6 represents , , , , or X7 represents a monovalent group containing a steroidal group, trifluoromethyl group, fluorine group, alkyl group with 2 to 30 carbon atoms, or a nitrogen-containing cyclic structure derived from pyridine, pyrimidine, triazine, piperidine, and piperazine.

[0040] The diamine compound shown in formula (III-1) above is preferably 2,4-diaminophenyl ethyl formate, 3,5-diaminophenyl ethyl formate, 2,4-diaminophenyl propyl formate, 3,5-diaminophenyl propyl formate, 1-dodecoxy-2,4-diaminobenzene, 1-hexadecoxy-2,4-diaminobenzene, 1-octadecoxy-2,4-diaminobenzene, or the diamine compounds shown in formulas (III-1-1) to (III-1-6) below: Equation (III-1-1) Equation (III-1-2) Equation (III-1-3) Equation (III-1-4) Equation (III-1-5) Equation (III-1-6).

[0041] The diamine compounds represented by formula (III-2) are shown below: Equation (III-2).

[0042] In formula (III-2), X12 represents a hydrogen atom, an acetyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen, and X12 in each repeating unit may be the same or different. X13 is an integer from 1 to 3.

[0043] The diamine compound represented by formula (III-2) is preferably selected from (1) X 13 is 1: p-diaminebenzene, m-diaminebenzene, o-diaminebenzene or 2,5-diaminetoluene, etc.; (2) X 13 is 2:4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl or 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, etc.; (3)X 13 is 3:1,4-bis(4'-aminophenyl)benzene, preferably selected from p-diaminobenzene, 2,5-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl or 1,4-bis(4'-aminophenyl)benzene.

[0044] The diamine compounds represented by formula (III-3) are shown below: Equation (III-3).

[0045] In equation (III-3), X 14 represents an integer from 2 to 12.

[0046] The diamine compounds represented by formula (III-4) are shown below: Equation (III-4).

[0047] In formula (III-4), X 15 represents an integer from 1 to 5. Formula (III-4) is preferably selected from 4,4'-diaminodiphenyl sulfide.

[0048] The diamine compounds represented by formula (III-5) are shown below: Equation (III-5).

[0049] In formula (III-5), X16 and X18 may be the same or different, and respectively represent divalent organic groups, while X17 represents divalent groups derived from nitrogen-containing cyclic structures such as pyridine, pyrimidine, triazine, piperidine and piperazine.

[0050] The diamine compounds represented by formula (III-6) are shown below: Equation (III-6).

[0051] In formula (III-6), X19, X20, X21 and X22 can be the same or different, and can represent hydrocarbon groups with 1 to 12 carbon atoms. X23 represents an integer from 1 to 3, and X24 represents an integer from 1 to 20.

[0052] The diamine compounds represented by formula (III-7) are shown below: Equation (III-7).

[0053] In equation (III-7), X 25 represents Or cyclohexyl, X 26 represents -CH 2-, X 27 represents phenyl or cyclohexyl, and X 28 represents a hydrogen atom or heptyl.

[0054] The diamine compound represented by formula (III-7) is preferably selected from the diamine compounds represented by formulas (III-8-1) to (III-8-2): Equation (III-7-1) Equation (III-7-2).

[0055] Other diamine compounds represented by formulas (III-8) to (III-24) are shown below: Equation (III-8) Equation (III-9) Equation (III-10) Equation (III-11) Equation (III-12) Equation (III-13) Equation (III-14) Equation (III-15) Equation (III-16) Equation (III-17) Equation (III-18) Equation (III-19) Equation (III-20) Equation (III-21) Equation (III-22) Equation (III-23) Equation (III-24).

[0056] In formulas (III-16) to (III-24), X 29 is preferably an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, while X 30 is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0057] The other diamine compound (a2-2) preferably includes, but is not limited to, 1,2-diaminoethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, and 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1 ,3-Diaminobenzene, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane, ethyl 2,4-diaminophenylformate, compounds represented by formula (III-1-1), (III-1-2), (III-1-5), (III-1-6), (III-2-1), (III-2-11), p-diaminobenzene, m-diaminobenzene, o-diaminobenzene, and (III-7-1).

[0058] The other diamine compounds (a2-2) mentioned above can be used alone or in combination.

[0059] In the specific example disclosed herein, based on the total amount of the diamine component (a2) used being 100 mol, the amount of the other diamine compound (a2-2) used is 40 to 95 mol, preferably 50 to 92 mol, and more preferably 60 to 90 mol. [Second polymer] [(A2)]

[0060] In some embodiments disclosed herein, the polymer (A) further includes a second polymer (A2). The second polymer (A2) is prepared by reacting a second mixture. The second mixture comprises a tetracarboxylic dianhydride component (a3) ​​and a diamine component (a4). Specifically, the second polymer (A2) is selected from the group consisting of polyamide polymers, polyimide polymers, polyimide block copolymers, and any combination thereof. Preferably, the second polymer (A2) is a polyamide polymer.

[0061] The tetracarboxylic dianhydride component (a3) ​​includes at least one of aliphatic tetracarboxylic dianhydride compounds, alicyclic tetracarboxylic dianhydride compounds, aromatic tetracarboxylic dianhydride compounds, and tetracarboxylic dianhydride compounds represented by formulas (I-1) to (I-6), or a combination of the above compounds. Specific examples of the aforementioned aliphatic tetracarboxylic dianhydride compounds, alicyclic tetracarboxylic dianhydride compounds, and aromatic tetracarboxylic dianhydride compounds are all the same as those included in the first mixture, and the tetracarboxylic dianhydride compounds represented by formulas (I-1) to (I-6) are also as described above, and therefore will not be repeated here. Similarly, the tetracarboxylic dianhydride component (a3) ​​can be used alone or in combination with multiple tetracarboxylic dianhydride compounds.

[0062] Based on a total mole count of 100 moles for the diamine component (a4), the preferred usage range for the tetracarboxylic acid dianhydride component (a3) ​​is 80 to 120 moles, more preferably 85 to 115 moles.

[0063] The diamine component (a4) may also be the same as the aforementioned diamine component (a2), that is, it may contain the diamine compound (a2-1) and / or other diamine compounds (a2-2) shown in formula (II), and the diamine compound (a2-1) and / or other diamine compounds (a2-2) may be used alone or in combination. Preferably, the diamine component (a4) contains other diamine compounds (a2-2), or may consist only of other diamine compounds (a2-2).

[0064] In the specific example disclosed herein, based on a total amount of polymer (A) of 100 parts by weight, the amount of the first polymer (A1) used is 40 to 80 parts by weight, preferably 40 to 75 parts by weight, more preferably 45 to 75 parts by weight; and the amount of the second polymer (A2) used is 20 to 60 parts by weight, preferably 25 to 60 parts by weight, more preferably 25 to 55 parts by weight. If the amounts of both the first polymer (A1) and the second polymer (A2) fall within the above ranges, the reliability of the resulting liquid crystal alignment agent is better.

[0065] The weight average molecular weight of the first polymer (A1) can be from 30,000 to 200,000; more preferably from 30,000 to 180,000; and even more preferably from 30,000 to 150,000.

[0066] The weight average molecular weight of the second polymer (A2) can be from 30,000 to 200,000; more preferably from 30,000 to 180,000; and even more preferably from 30,000 to 150,000.

[0067] The amide content of the polymer (A) can be 30% to 80%, more preferably 35% to 80%, and even more preferably 45% to 75%. If the amide content of the polymer (A) falls within the above range, the reliability of the prepared liquid crystal alignment agent is better. [polymer] [(A)] [Preparation method] []

[0068] As previously stated, polymer (A) comprises the first polymer (A1) and may optionally comprise a second polymer (A2). The first polymer (A1) and / or the second polymer (A2) may be selected from the group consisting of polyamide polymers, polyimide polymers, polyimide-based block copolymers, and any combination thereof. The following further describes, using the first polymer (A1) as an example, methods for preparing polyamide polymers, polyimide polymers, and polyimide-based block copolymers using the first mixture. Similarly, the second polymer (A2) can also be prepared using the following methods, only requiring the first mixture to be replaced with the second mixture. [Preparation method of polyamide polymer]

[0069] The method for preparing this polyamide polymer involves first dissolving a first mixture in a solvent, wherein the first mixture comprises a tetracarboxylic acid dianhydride component (a1) and a diamine component (a2), and then carrying out a polycondensation reaction at a temperature of 0°C to 100°C. After reacting for 1 to 24 hours, the reaction solution is subjected to vacuum distillation using an evaporator to obtain polyamide. Alternatively, the reaction solution can be poured into a large amount of lean solvent to obtain a precipitate. The precipitate is then dried under reduced pressure to obtain polyamide.

[0070] The solvent used in the polycondensation reaction may be the same as or different from the solvent in the liquid crystal alignment agent described below, and there are no particular limitations on the solvent used in the polycondensation reaction, as long as it can dissolve the reactants and products. The solvent is preferably including, but not limited to, (1) aprotic polar solvents, such as: N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea or hexamethyl phosphate triamine, etc.; or (2) phenolic solvents, such as: m-cresol, xylenol, phenol or halogenated phenols, etc. Based on the total amount of the first mixture used being 100 parts by weight, the amount of solvent used in the polycondensation reaction is preferably from 200 parts by weight to 2000 parts by weight, and more preferably from 300 parts by weight to 1800 parts by weight.

[0071] It is worth noting that in the polycondensation reaction, a suitable amount of lean solvent can be used in combination, where the lean solvent will not cause polyamide precipitation. The lean solvent can be used alone or in combination, and includes, but is not limited to, (1) alcohols, such as methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, or triethylene glycol; (2) ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; (3) esters, such as methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, or ethylene glycol ethyl ether acetate, etc.; (4) ethers, For example: ethers such as diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether; (5) halogenated hydrocarbons, such as halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichlorobenzene; or (6) hydrocarbons, such as hydrocarbons such as tetrahydrofuran, hexane, heptane, octane, benzene, toluene or xylene or any combination of the above solvents. Based on the amount of the diamine component (a2) used being 100 parts by weight, the amount of lean solvent is preferably 0 to 60 parts by weight, and more preferably 0 to 50 parts by weight. [Preparation method of polyimide polymer]

[0072] The method for preparing this polyimide polymer involves heating the polyamide prepared by the above-described method in the presence of a dehydrating agent and a catalyst. During the heating process, the amide functional groups in the polyamide can be converted into amide functional groups (i.e., amide imidization) via a dehydration and ring-closing reaction.

[0073] The solvent used in the dehydration and ring-closing reaction can be the same as the solvent (C) in the liquid crystal alignment agent, so it will not be described again here. Based on the amount of polyacrylic acid used being 100 parts by weight, the amount of solvent used in the dehydration and ring-closing reaction is preferably 200 to 2000 parts by weight, and more preferably 300 to 1800 parts by weight.

[0074] To obtain a better degree of amide imidization of polyamide, the operating temperature of the dehydration ring-closure reaction is preferably between 40°C and 200°C, more preferably between 40°C and 150°C. If the operating temperature of the dehydration ring-closure reaction is below 40°C, the amide imidization reaction is incomplete, thus reducing the degree of amide imidization of the polyamide. However, if the operating temperature of the dehydration ring-closure reaction is above 200°C, the weight average molecular weight of the resulting polyimide is lower.

[0075] The dehydrating agent used in the dehydration ring-closing reaction can be selected from acid anhydride compounds, specifically, acid anhydride compounds such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. Based on the amount of polyacrylic acid being 1 mole, the amount of dehydrating agent used is 0.01 mole to 20 moles. The catalyst used in the dehydration ring-closing reaction can be selected from (1) pyridine compounds, such as pyridine, trimethylpyridine, or dimethylpyridine; and (2) tertiary amine compounds, such as triethylamine. Based on the amount of dehydrating agent being 1 mole, the amount of catalyst used can be 0.5 moles to 10 moles. [Preparation method of polyimide block copolymer]

[0076] The polyimide-based block copolymer is selected from polyamide block copolymers, polyimide block copolymers, polyamide-polyimide block copolymers, or any combination of the above polymers.

[0077] A preferred method for preparing polyimide-based block copolymers is to first dissolve the starting material in a solvent and then carry out a polycondensation reaction, wherein the starting material includes at least one polyamide and / or at least one polyimide, and may further include a carboxylic anhydride component and a diamine component.

[0078] The carboxylic anhydride and diamine components in the starting material can be the same as the tetracarboxylic dianhydride (a1) and diamine (a2) components used in the method for preparing polyamide, and the solvent used in the polycondensation reaction can be the same as the solvent (C) in the liquid crystal alignment agent described below, which will not be elaborated here.

[0079] Based on the amount of starting material used being 100 parts by weight, the amount of solvent used in the polycondensation reaction is preferably from 200 parts by weight to 2000 parts by weight, and more preferably from 300 parts by weight to 1800 parts by weight. The operating temperature of the polycondensation reaction is preferably from 0°C to 200°C, and more preferably from 0°C to 100°C.

[0080] The starting materials are preferably including, but not limited to, (1) two polyamides with different terminal groups and different structures; (2) two polyimides with different terminal groups and different structures; (3) polyamides and polyimides with different terminal groups and different structures; (4) polyamide, a carboxylic anhydride component, and a diamine component, wherein at least one of the carboxylic anhydride component and the diamine component has a different structure from the carboxylic anhydride component and the diamine component used to form the polyamide; (5) polyimide, a carboxylic anhydride component, and a diamine component, wherein at least one of the carboxylic anhydride component and the diamine component has a different structure from the carboxylic anhydride component and the diamine component used to form the polyimide; (6) polyamide, polyimide, a carboxylic anhydride component, and The diamine component, wherein at least one of the carboxylic anhydride component and the diamine component has a different structure from the carboxylic anhydride component and the diamine component used to form the polyamide or polyimide; (7) two polyamides, carboxylic anhydride components and diamine components with different structures; (8) two polyimides, carboxylic anhydride components and diamine components with different structures; (9) two polyamides and diamine components with anhydride end groups and different structures; (10) two polyamides and carboxylic anhydride components with amino end groups and different structures; (11) two polyimides and diamine components with anhydride end groups and different structures; or (12) two polyimides and carboxylic anhydride components with amino end groups and different structures.

[0081] To the extent that it does not affect the effectiveness of this disclosure, polyamide, polyimide, and polyimide-based block copolymers are preferably end-modified polymers whose molecular weight has been adjusted beforehand. Using end-modified polymers can improve the coating performance of liquid crystal alignment agents. End-modified polymers can be prepared by adding a monofunctional compound during the polycondensation reaction of polyamide.

[0082] Specific examples of monofunctional compounds include, but are not limited to: (1) monocarboxylic anhydrides, such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride or n-hexadecyl succinic anhydride; (2) monoamine compounds, such as aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecanylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine or n-eicosylamine; or (3) monoisocyanate compounds, such as phenyl isocyanate or naphthyl isocyanate. [Polysiloxane] [(B)]

[0083] The polysiloxane (B) disclosed herein is prepared by reacting isocyanate-containing polysiloxane (b1) with compound (b2). [Polysiloxanes containing isocyanate groups] [(b1)]

[0084] The isocyanate-containing polysiloxane (b1) is a copolymer obtained by polycondensation of a third mixture, preferably a copolymer obtained by hydrolysis and partial condensation.

[0085] The third mixture contains a silane monomer (b1-1) as shown in formula (VI-1): Si(R a) c(OR b) 4-c formula (VI-1) In formula (VI-1): Ra represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an isocyanate group having 1 to 10 carbon atoms, and at least one Ra contains an isocyanate group having 1 to 10 carbon atoms; when Ra is plural, the Ra groups may be the same or different; Rb represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an amide group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; when Rb is plural, the Rb groups may be the same or different; and c represents an integer from 1 to 3.

[0086] More specifically, when Ra in formula (VI-1) represents an alkyl group having 1 to 10 carbon atoms, Ra is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, tributyl, n-hexyl, or n-decyl. Furthermore, Ra can also be an alkyl group having other substituents, specifically, Ra is, for example, trifluoromethyl, 3,3,3-trifluoropropyl, 3-aminopropyl, or 3-mercaptopropyl.

[0087] When Ra in formula (VI-1) represents an alkenyl group having 2 to 10 carbon atoms, Ra is, for example, a vinyl group. Ra can also be an alkenyl group having other substituents, specifically, Ra is, for example, 3-propenyloxypropyl or 3-methpropenyloxypropyl.

[0088] When Ra in formula (VI-1) represents an aryl group having 6 to 15 carbon atoms, Ra is, for example, a phenyl, tolyl, or naphthyl. Ra can also be an aryl group with other substituents, specifically, Ra is, for example, o-hydroxyphenyl, 1-(o-hydroxyphenyl)ethyl, 2-(o-hydroxyphenyl)ethyl, or 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyl.

[0089] When Ra in formula (VI-1) represents an isocyanate group with 1 to 10 carbon atoms, Ra is, for example, 3-isocyanopropyl.

[0090] Furthermore, when Rb in formula (VI-1) represents an alkyl group having 1 to 6 carbon atoms, specifically, Rb is, for example, methyl, ethyl, n-propyl, isopropyl, or n-butyl. When Rb in formula (VI-1) represents an acetyl group having 1 to 6 carbon atoms, specifically, Rb is, for example, acetyl. When Rb in formula (VI-1) represents an aryl group having 6 to 15 carbon atoms, specifically, Rb is, for example, phenyl.

[0091] Specific examples of silane monomers (b1-1) include 3-Isocyanato propyl triethoxy silane and 3-Isocyanato propyl diethoxy methyl silane.

[0092] Based on the total amount of monomers in the third mixture being 1 mol, the amount of silane monomer (b1-1) used is 0.6 mol to 1 mol, preferably 0.7 mol to 1 mol, and more preferably 0.8 mol to 1 mol. When the amount of silane monomer (b1-1) used falls within the above range, the liquid crystal contact angle of the prepared liquid crystal alignment agent is relatively low.

[0093] The third mixture may further contain other silane monomers (b1-2) represented by formula (VI-2): Si(R h) f(OR i) 4-f equation (VI-2) In formula (VI-2): Rh is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an alkyl group containing an anhydride group; When f is a complex number, R and h are either the same or different; Ri is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acetyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; When 4-f is a complex number, Ri can be the same or different; and f is an integer from 1 to 3.

[0094] When Rh in formula (VI-2) represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, specific examples and preferred examples are shown above as Ra, and will not be repeated here.

[0095] When Rh in formula (VI-2) represents an alkyl group containing an anhydride group, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. Specifically, the alkyl group containing an anhydride group is, for example, ethyl succinic anhydride as shown in formula (VI-2-1), propyl succinic anhydride as shown in formula (VI-2-2), or propyl glutaric anhydride as shown in formula (VI-2-3). It is worth mentioning that the anhydride group is a group formed by intramolecular dehydration of a dicarboxylic acid, wherein the dicarboxylic acid is, for example, succinic acid or glutaric acid. Formula (VI-2-1) Equation (VI-2-2) Formula (VI-2-3)

[0096] When Ri in formula (VI-2) represents an alkyl group having 1 to 6 carbon atoms, a acetyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms, specific examples and preferred examples are shown above as Rb, and will not be repeated here.

[0097] Other silane monomers (b1-2) represented by formula (VI-2) may be used alone or in combination, and the other silane monomers (b1-2) represented by formula (VI-2) comprise compounds having one silicon atom. Compounds having one silicon atom include silane compounds having four hydrolyzable groups, silane compounds having three hydrolyzable groups, silane compounds having two hydrolyzable groups, silane compounds having one hydrolyzable group, or combinations thereof.

[0098] Specific examples of silane compounds having four hydrolyzable groups include tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetran-propoxysilane, tetraisopropoxysilane, tetran-butoxysilane, tetradibutoxysilane, or combinations thereof.

[0099] Specific examples of silane compounds having three hydrolyzable groups include methyltrimethoxysilane (MTMS), methyltriethoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-n-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, and n-butyltriethoxysilane. thoxysilane), n-hexyltrimethoxysilane, n-hexyltriethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-acryoyloxypropyltrimethoxysilane, 3-methylacryloyloxypropyltrimethoxysilane (MPTMS), 3-methylacryloyloxypropyltriethoxysilane, phenyltrimethoxysilane (PTMS), phenyltriethoxysilane,PTES), p-hydroxyphenyltrimethoxysilane, 1-(p-hydroxyphenyl)ethyltrimethoxysilane, 2-(p-hydroxyphenyl)ethyltrimethoxysilane, 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyltrimethoxysilane, trifluoromethyltrimethoxysilane ethyltrimethoxysilane), trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(triphenoxysilyl)propylsuccinic anhydride The following compounds are permitted: propyl succinic anhydride, commercially available from Shin-Etsu Chemical Co., Ltd.: 3-(trimethoxysilyl)propyl succinic anhydride (trade name X-12-967); commercially available from WACKER Corporation: 3-(triethoxysilyl)propyl glutaric anhydride (trade name GF-20); 3-(trimethoxysilyl)propyl glutaric anhydride (TMSG); 3-(triethoxysilyl)propyl glutaric anhydride; 3-(triphenoxysilyl)propyl glutaric anhydride; or combinations thereof.

[0100] Specific examples of silane compounds having two hydrolyzable groups include methyldimethoxysilane, methyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyl[2-(perfluoro-n-octyl)ethyl]dimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, di-n-butyldimethoxysilane, or combinations thereof.

[0101] Specific examples of silane compounds having one hydrolyzable group include methoxydimethylsilane, methoxytrimethylsilane, methoxymethyldiphenylsilane, tri-n-butylethoxysilane, or combinations thereof.

[0102] Other silane monomers (b1-2) with the structure shown in formula (VI-2) are preferably tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, or combinations of the above compounds.

[0103] Based on the total amount of monomers in the third mixture being 1 mol, the amount of silane monomer (b1-2) used is 0 to 0.4 mol, preferably 0 to 0.3 mol, and more preferably 0 to 0.2 mol.

[0104] When the polysiloxane (B) does not use a polysiloxane (b1) containing isocyanate groups, the resulting liquid crystal alignment agent has poor reliability and a high liquid crystal contact angle. [Polysiloxanes containing isocyanate groups] [(b1)] [Preparation method] []

[0105] The polycondensation reaction of isocyanate-containing polysiloxanes (b1) can be formed using conventional methods, such as adding an organic solvent, water, or selectively adding a catalyst to a third mixture, followed by heating at 50°C to 150°C using an oil bath or similar method, with a preferred heating time of 0.5 hours to 120 hours. During heating, the mixture can be stirred or placed under reflux conditions.

[0106] The organic solvents mentioned above are not particularly limited and may be the same as or different from the solvent (C) contained in the liquid crystal alignment agent disclosed herein.

[0107] Specific examples of such organic solvents include hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, diethyl ketone, cyclohexanone, 2-butanone, and 2-hexanone; esters such as ethyl acetate, n-butyl acetate, isoamyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, and ethyl lactate; and ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, and dioxane. Solvents: alcohols such as 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, etc.; amides such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethyltriazolidinyl phosphate, 1,3-dimethyl-2-imidazolidinedione, etc., or combinations of the above organic solvents.

[0108] The above-mentioned organic solvents can be used alone or in combination.

[0109] Based on the third mixture being 100 parts by weight, the amount of organic solvent used is preferably from 10 parts by weight to 1200 parts by weight, more preferably from 30 parts by weight to 1000 parts by weight.

[0110] Based on the fact that the hydrolyzable group of the third mixture is 1 mol, the amount of water used is preferably 0.5 mol to 2 mol.

[0111] There are no particular limitations on the catalyst, but preferably, the catalyst is selected from acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds, or combinations thereof.

[0112] Specific examples of acids include hydrochloric acid, nitric acid, sulfuric acid, fluorine, oxalic acid, phosphoric acid, acetic acid, trifluoroacetic acid, formic acid, polycarboxylic acids, polycarboxylic anhydrides, or combinations thereof.

[0113] Specific examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, or combinations thereof.

[0114] Specific examples of organic bases include primary or secondary organic amines such as ethylamine, diethylamine, piperazine, pipeidine, pyrrolidine, and pyrrole; tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, and diazabicycloundecene; quaternary organic amines such as tetramethylammonium hydroxide; or combinations of the above compounds.

[0115] The amount of catalyst used varies depending on the type, temperature, and other reaction conditions, and can be set appropriately. For example, based on the fact that all silane compounds are 1 mol, the amount of catalyst added is 0.01 mol to 5 mol, preferably 0.03 mol to 3 mol, and more preferably 0.05 mol to 1 mol.

[0116] From a stability perspective, after the polymerization condensation reaction is complete, it is preferable to wash the organic solvent layer fractionated from the reaction solution with water. When performing this washing, it is preferable to use water containing a small amount of salt, such as an aqueous solution of approximately 0.2% by weight of ammonium nitrate. Washing can continue until the water layer becomes neutral. Then, the organic solvent layer is dried as needed using desiccants such as anhydrous calcium sulfate or molecular sieves to remove the organic solvent, thus obtaining the isocyanate-containing polysiloxane (b1). [Compound] [(b2)]

[0117] The compound (b2) comprises a structure of formula (V): Formula (V) In formula (V): E1 is an alkyl group with 1 to 30 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms substituted or unsubstituted with an alkyl or alkoxy group with 1 to 20 carbon atoms, or a hydrocarbon group with 17 to 51 carbon atoms containing a steroid skeleton. Some of the hydrogen atoms in the alkyl and alkoxy groups of E1 are substituted or unsubstituted. L0 represents a single bond, *1-O-, *1-COO-, or *1-OCO-, where *1 represents the bond with E1; L1 is a single bond, and is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group of formula (V-1) or formula (V-2) with 1 to 20 carbon atoms: Equation (V-1) Equation (V-2) Where *2 represents the bond with Z; and when L1 is a single bond, L0 is a single bond; Z is a monovalent organic group that reacts with isocyanate groups to form a binding group.

[0118] The alkyl group with 1 to 30 carbon atoms described in E1 of formula (V) above can be linear or branched, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, dibutyl, tributyl, n-pentyl, 3-methylbutyl, 2-methylbutyl, 1-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 3,3-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 1,2-dimethylbutyl, 1,1-dimethylbutyl, n-heptyl, 5-methylhexyl, 4-methylhexyl, 3-methylhexyl, 2-methylhexyl, 1-methylhexyl, 4,4-dimethylpentyl, 3 4-Dimethylpentyl, 2,4-Dimethylpentyl, 1,4-Dimethylpentyl, 3,3-Dimethylpentyl, 2,3-Dimethylpentyl, 1,3-Dimethylpentyl, 2,2-Dimethylpentyl, 1,2-Dimethylpentyl, 1,1-Dimethylpentyl, 2,3,3-Trimethylbutyl, 1,3,3-Trimethylbutyl, 1,2,3-Trimethylbutyl, n-Octyl, 6-Methylheptyl, 5-Methylheptyl, 4-Methylheptyl, 3-Methylheptyl, 2-Methylheptyl, 1-Methylheptyl, 2-Ethylhexyl, n-Nonyl, n-Decyl, n-Undecyl, n-Dodecyl, n-Tetaneyl, n-Tetradecyl, n-Decanyl, n-Hexadecyl, n-Hexadecanyl, n-Octadecyl, n-Nondecyl, etc.

[0119] The cycloalkyl group with 3 to 10 carbon atoms described in E 1 of formula (V) above can be, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc. These cycloalkyl groups may be substituted with or without an alkoxy group having 1 to 20 carbon atoms. Specific examples of the alkoxy group having 1 to 20 carbon atoms can be found in the specific examples given in the description of alkyl groups having 1 to 30 carbon atoms above. Specific examples of the alkoxy group having 1 to 20 carbon atoms can be found in the alkyl group of the specific examples given in the description of alkyl groups having 1 to 30 carbon atoms above, which is a group formed by combining an oxygen atom. The alkyl group and alkoxy group described in E 1 may have at least some of their hydrogen atoms substituted, and the group used to substitute the hydrogen atoms can be, for example, a nitrile group, a fluorine atom, a trifluoromethyl group, etc.

[0120] The hydrocarbon group containing a steroid skeleton with 17 to 51 carbons described in E 1 of formula (V) above can be, for example, the group shown in formulas (S-1) to (S-3) below, where *5 represents the bond between the above group and L 0 of formula (V). Equation (S-1) Equation (S-2) Equation (S-3)

[0121] Preferably, E1 can be selected from a group consisting of alkyl groups having 1 to 20 carbon atoms, fluoroalkyl groups having 1 to 20 carbon atoms, groups of formula (S-1) above, and groups of formula (S-3) above.

[0122] The alkyl group with 1 to 20 carbon atoms mentioned in formula (V) above can, for example, be a group obtained by removing one hydrogen atom from each of the aforementioned alkyl groups with 1 to 30 carbon atoms.

[0123] In the above formula (V), Z is preferably a carboxyl group.

[0124] The compound represented by formula (V) above is preferably a compound represented by formulas (V-3) to (V-10) below: Equation (V-3) Equation (V-4) Equation (V-5) Equation (V-6) Equation (V-7) Equation (V-8) Equation (V-9) Equation (V-10).

[0125] In equations (V-3) to (V-10), u is an integer from 1 to 5, v is an integer from 1 to 18, w is an integer from 1 to 20, k is an integer from 1 to 5, p is 0 or 1, q is an integer from 1 to 18, r is an integer from 0 to 18, and j is an integer from 1 to 18. s and t are each independently an integer from 0 to 2. However, s and t are not both 0.

[0126] Preferably, in equation (V-3), v is an integer from 1 to 18, but more preferably an integer from 1 to 12. In equation (V-4), w is preferably an integer from 5 to 20, but more preferably from 10 to 18. In equation (V-5), w is preferably an integer from 1 to 17, but more preferably from 3 to 12. In equation (V-6), w is preferably an integer from 1 to 15, but more preferably from 1 to 8. In equation (V-10), w is preferably an integer from 1 to 15, but more preferably from 1 to 8. In equations (V-7) and (IV-6), r is preferably an integer from 0 to 15, but more preferably from 0 to 8. In equation (V-8), q is preferably an integer from 1 to 12, but more preferably from 1 to 5. In the above formula (V-10), j can preferably be an integer from 1 to 15, but it is even better to use an integer from 1 to 8.

[0127] Of the above compounds, at least one of formulas (V-4) to (V-7), (V-9), and (V-10) is preferred. Specifically, formulas (V-1') to (V-8') are preferred: Equation (V-1') Equation (V-2') Equation (V-3') Equation (V-4') Equation (V-5') Equation (V-6') Equation (V-7') Equation (V-8').

[0128] When the polysiloxane (B) is not used with compound (b2), the resulting liquid crystal alignment agent has poor reliability and a high liquid crystal contact angle.

[0129] Based on the total amount of monomers in the third mixture being 1 mol, the amount of compound (b2) used is 0.05 mol to 0.5 mol, preferably 0.1 mol to 0.45 mol, but more preferably 0.2 mol to 0.4 mol. If the amount of compound (b2) used falls within the above range, the liquid crystal contact angle of the prepared liquid crystal alignment agent is lower.

[0130] Based on the amount of polymer (A) used being 100 parts by weight, the amount of polysiloxane (B) used being 1 to 30 parts by weight, preferably 1 to 28 parts by weight, but more preferably 1 to 25 parts by weight. [Polysiloxane] [(B)] [Preparation method] []

[0131] The polysiloxane (B) used in this disclosure can be synthesized by reacting the above-mentioned isocyanate-containing polysiloxane (b1) with compound (b2) in the presence of a catalyst.

[0132] As a catalyst, well-known compounds such as organic salts or hardening accelerators that promote the reaction between epoxides and acid anhydrides can be used.

[0133] The aforementioned organic salts can include primary or secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine, and pyrrole; tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, and diazabicycloundecene; and quaternary organic amines such as tetramethylammonium hydroxide. Among these organic amines, tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, and 4-dimethylaminopyridine, or quaternary organic amines such as tetramethylammonium hydroxide, are preferred.

[0134] Specific examples of the aforementioned hardening accelerators include tertiary amines such as benzyl dimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, cyclohexyl dimethylamine, and triethanolamine; 2-methylimidazole, 2-n-heptylimidazole, 2-n-alkylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1-(2-cyanoethyl)-2-methylimidazole, 1-(2-cyanoethyl)-2-5-n-undecylimidazole, 1-(2- 1-(2-Cyanoethyl)-2-phenylimidazolium, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 2-phenyl-4,5-di(hydroxymethyl)imidazolium, 1-(2-cyanoethyl)-2-phenyl-4,5-di[(2'-cyanoethoxy)methyl]imidazolium, 1-(2-cyanoethyl-2-undecylimidazolium phenyltriphenyltrioxide, 1-(2-cyanoethyl)-2-phenylimidazolium phenyltriphenyltrioxide, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazolium phenyltriphenyltrioxide, 2, Imidazole compounds such as 4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-S-triazine, 2,4-diamino-6-(2'-n-undecylimidazol)ethyl-S-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]ethyl-S-triazine, 2-methylimidazolium triisocyanate adducts, 2-phenylimidazolium triisocyanate adducts, and 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-S-triazine triisocyanate adducts; organophosphorus compounds such as diphenylphosphine, triphenylphosphine, and triphenyl phosphite; benzyl triphenyl phosphonium chloride. 1,8-diazabicyclo[5.4] quaternary phosphonium salts including tetra-n-butylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, tetra-n-butylphosphonium-O,O-diethylphosphonium dithiosulfate, tetra-n-butylphosphonium benzotriazolate, tetra-n-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate, and tetraphenylphosphonium tetraphenylborate;[0] Diazabicyclic olefins such as undecene-7 or its organic acid salts; organometallic compounds such as zinc octanoate, tin octanoate, and aluminum acetylacetone complex; quaternary ammonium salts such as tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride; boron compounds such as boron trifluoride and triphenyl borate; metal halide compounds such as zinc chloride and tin tetrachloride; high-melting-point dispersible latent curing accelerators such as dicyandiamide or amine-epoxy resin adducts; microcapsule-type latent curing accelerators in which the surface of the above-mentioned imidazole compounds, organophosphorus compounds, or quaternary phosphonium salts is coated with polymer; amine salt type latent curing accelerators; latent curing accelerators such as Lewis acid salts and Bronsted acid salts that are high-temperature dissociative thermo-cationic polymerization type; and other latent curing accelerators. .

[0135] Preferred examples of curing accelerators are quaternary ammonium salts including tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride.

[0136] Preferred examples of curing accelerators are quaternary ammonium salts including tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride.

[0137] The reaction temperature is preferably from 0°C to 200°C, and more preferably from 50°C to 150°C. The reaction time is preferably from 0.1 hours to 50 hours, and more preferably from 0.5 hours to 20 hours.

[0138] The synthesis reaction of polysiloxane (B) can be carried out in the presence of an organic solvent, as needed. The organic solvent is not particularly limited and may be the same as or different from the organic solvent used in the preparation of epoxy-containing polysiloxane (b1) and the solvent (C) contained in the liquid crystal alignment agent disclosed herein. Preferred examples of the aforementioned organic solvents are 2-butanone, 2-hexanone, methyl isobutyl ketone, n-butyl acetate, or combinations thereof.

[0139] The weight average molecular weight of the polysiloxane (B) disclosed herein is 2,000 to 20,000; more preferably 3,000 to 18,000; and even more preferably 5,000 to 15,000.

[0140] The solvent used in the liquid crystal alignment agent disclosed herein is not particularly limited, as long as it can dissolve the polymer (A), polysiloxane (B) and any other components and does not react with them. Preferably, it is the same solvent used in the synthesis of polyacrylic acid as described above. At the same time, the lean solvent used in the synthesis of the polyacrylic acid can also be used.

[0141] Specific examples of solvent (C) include, but are not limited to, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, or N,N-dimethylformamide or N,N-dimethylacetamide. Solvent (C) can be used alone or in combination.

[0142] The amount of polymer (A) used is 100 parts by weight, and the amount of solvent (C) used is 500 to 3000 parts by weight, preferably 800 to 3000 parts by weight, and even more preferably 800 to 2500 parts by weight.

[0143] Without affecting the effectiveness of this disclosure, the liquid crystal alignment agent may also selectively contain additives (D), wherein additives (D) include compounds having at least two epoxy groups, silane compounds having functional groups, or combinations thereof.

[0144] Compounds having at least two epoxy groups include, but are not limited to, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromonepentyl glycol diglycidyl ether, 1,3,5,6-tetracyclooxypropyl-2,4-hexanediol, N,N,N',N'-tetracyclooxypropyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane, 3-(N,N-diglycidyl)aminopropyltrimethoxysilane, or combinations of the above compounds.

[0145] Compounds with at least two epoxy groups can be used alone or in combination.

[0146] Based on the amount of polymer (A) used being 100 parts by weight, the amount of compound having at least two epoxy groups used may be from 0 to 40 parts by weight, and preferably from 0.1 to 30 parts by weight.

[0147] Specific examples of silane compounds having functional groups include, but are not limited to, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyldimethoxysilane, and 3-ureidopropyltrimethoxysilane. silane), 3-ureopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triacryldecane, 10-triethoxysilyl-1,4,7-triacryldecane, 9-trimethoxysilyl-3,6-di Acrylonitrile acetate, 9-triethoxysilyl-3,6-diacrylonitrile acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(ethylene oxide)-3-aminopropyltrimethoxysilane, N-bis(ethylene oxide)-3-aminopropyltriethoxysilane, or combinations thereof.

[0148] Silane compounds with functional groups can be used alone or in combination.

[0149] Based on the amount of polymer (A) used being 100 parts by weight, the amount of silane compound having functional groups used may be 0 to 10 parts by weight, and preferably 0.5 to 10 parts by weight.

[0150] Based on the total amount of polymer (A) used being 100 parts by weight, the amount of additive (D) used is preferably from 0.5 parts by weight to 50 parts by weight, and more preferably from 1 part by weight to 45 parts by weight. [Manufacturing Method of Liquid Crystal Alignment Agent] []

[0151] The method for preparing the liquid crystal alignment agent disclosed herein is not particularly limited and can be prepared using a general mixing method. For example, the polymer (A) prepared as described above and the polysiloxane (B) are first mixed uniformly to form a mixture. Then, a solvent (C) is added at a temperature of 0°C to 200°C, and an additive (D) is selectively added. Finally, the mixture is continuously stirred with a stirring device until dissolved. Alternatively, it is preferable to add the solvent (C) at a temperature of 20°C to 60°C.

[0152] At 25°C, the viscosity of the liquid crystal alignment agent disclosed herein is typically 15 cps to 35 cps, preferably 17 cps to 33 cps, and even more preferably 20 cps to 30 cps. [Manufacturing method of liquid crystal alignment film and liquid crystal display element] []

[0153] This disclosure also provides a liquid crystal alignment film, which is formed from the aforementioned liquid crystal alignment agent.

[0154] This disclosure also provides a liquid crystal display element comprising the aforementioned liquid crystal alignment film.

[0155] The liquid crystal alignment film disclosed herein is formed using the aforementioned modulated liquid crystal alignment agent. Furthermore, the liquid crystal display element disclosed herein has a liquid crystal alignment film formed from the aforementioned liquid crystal alignment agent. The operating mode of the liquid crystal display element is not particularly limited, but a vertical alignment type is preferred.

[0156] The method for manufacturing the liquid crystal alignment film and liquid crystal display element disclosed herein may include: a first step of coating the liquid crystal alignment agent disclosed herein onto the conductive film of a pair of substrates having conductive films, and then heating the substrates to form a coating film; a second step of arranging the pair of substrates with the coating film formed opposite each other to construct a liquid crystal cell; and a third step of irradiating the pair of substrates having conductive films with light under the condition of applying voltage. [Step 1: Coating Formation]

[0157] In this step, two substrates with patterned transparent conductive films are used as a pair. The liquid crystal alignment agent disclosed herein is coated onto the surface of each substrate with the transparent conductive film. Preferably, the liquid crystal alignment agent is coated using lithography, spin coating, roll coating, or inkjet printing. The substrate referred to herein can be, for example, float glass, soda glass, or other glass; or a transparent plastic substrate such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin). The transparent conductive film on the substrate surface can be an NESA film (a registered trademark of PPG Industries, Inc.) formed from tin oxide (SnO2) or an ITO film formed from indium oxide and tin oxide (In2O3-SnO2). The formation of patterned transparent conductive films can be achieved, for example, by first forming an unpatterned transparent conductive film and then using a photo-etching patterning method, and using a mask with a predetermined pattern from the formation of the transparent conductive film. When coating liquid crystal alignment agents, to ensure good adhesion between the substrate surface and the transparent conductive film and the coating, a pretreatment with functional silane compounds, functional titanium compounds, etc., can be performed on the surface of the substrate where the coating is formed.

[0158] After coating the liquid crystal alignment agent, a pre-bake is preferably performed to prevent dripping. The pre-bake temperature can be from 30°C to 200°C, preferably from 40°C to 150°C, but more preferably from 40°C to 100°C. The pre-bake time can be from 0.25 minutes to 10 minutes, preferably from 0.5 minutes to 5 minutes. Afterwards, the solvent is completely removed, and the substrate is sintered (post-bake) to form the necessary polymer and amide structure through thermal amide imidization. The post-bake temperature can be from 80°C to 300°C, preferably from 120°C to 250°C. The post-bake time can be from 5 minutes to 200 minutes, preferably from 10 minutes to 100 minutes. Therefore, the thickness of the formed film can be from 0.001 μm to 1 μm, preferably from 0.005 μm to 0.5 μm.

[0159] The heating step following the application of the liquid crystal alignment agent removes the organic solvent, thereby forming a liquid crystal alignment film. At this time, the polymer contained in the liquid crystal alignment agent disclosed herein includes polyamide, or a amide polymer having both an amide structure and an amide structure. Subsequently, the formed coating is further heated, causing the polymer to undergo a dehydration and ring-closing reaction to form an amide-modified coating. The coating formed by the above method can be used directly as a liquid crystal alignment film, or it can be subjected to a predetermined friction treatment. [Step 2: Construction of Liquid Crystal Cells]

[0160] In this step, two substrates having the aforementioned liquid crystal alignment film are provided, and a liquid crystal layer containing a liquid crystal compound and a photopolymerizable compound is disposed between the two opposing substrates to form a liquid crystal cell. Examples of methods for manufacturing liquid crystal cells include the following two methods.

[0161] The first method is a conventional method (vacuum injection method). First, two substrates are placed opposite each other, forming a gap (cell gap) between the oppositely placed liquid crystal alignment films. The two substrates are then bonded together with an adhesive. Liquid crystal compound and photopolymerizable compound are injected into the cell gap defined by the substrate surface and the adhesive to fill the gap. The injection hole is then sealed to obtain a liquid crystal cell.

[0162] The second method is called One Drop Filling (ODF). On one of two substrates with a liquid crystal alignment film, a UV-curable adhesive is applied to a predetermined location. Next, a mixture of a liquid crystal compound and a photopolymerizable compound is dropped onto the predetermined location of the liquid crystal alignment film. The liquid crystal alignment film is then placed opposite the liquid crystal alignment film on the other substrate, and the two substrates are bonded together, allowing the liquid crystal to diffuse across the entire surface of the substrates. The entire substrate is then irradiated with UV light to harden the adhesive, thus creating liquid crystal cells. Regardless of the method used, after forming the liquid crystal cells, the substrate is heated to the temperature at which the liquid crystal compound becomes isotropic, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal filling.

[0163] As the aforementioned adhesive, epoxy resin containing alumina spheres can be used as both a hardener and a spacer. The liquid crystal compound is preferably a nematic liquid crystal with negative dielectric anisotropy, such as dicyanophenyl liquid crystal, pyridazinyl liquid crystal, Schiff base liquid crystal, azodicarbonyl liquid crystal, biphenyl liquid crystal, phenylcyclohexyl liquid crystal, terphenyl liquid crystal, etc. Furthermore, to achieve a faster response speed in the PSA mode liquid crystal display device, an alkenyl liquid crystal is preferably used, which is a monofunctional liquid crystal compound having one alkenyl or fluoroalkenyl group. The alkenyl liquid crystal can be a conventional alkenyl liquid crystal, such as compounds shown in formulas (L1-1) to (L1-9).

[0164] The photopolymerizable compound can be a compound having functional groups such as acrylonitrile, methacryl, or vinyl that are capable of free radical polymerization. From a reactivity point of view, a compound having at least two functional groups selected from acrylonitrile and methacryl is preferred. Furthermore, from the viewpoint of maintaining the alignment stability of liquid crystal molecules, the photopolymerizable compound serves as the liquid crystal framework, and a compound having at least two rings selected from cyclohexane and benzene is preferred. Alternatively, conventional photopolymerizable compounds can be used. The amount of the photopolymerizable compound used is preferably 0.1% to 0.5% of the total weight of the liquid crystal compound. The thickness of the liquid crystal layer is preferably 1 μm to 5 μm. [Step 3: Exposure Step]

[0165] After constructing the liquid crystal cells, a voltage is applied between the conductive films of the substrates, and light is simultaneously applied. The applied voltage can be, for example, a direct current (DC) or alternating current (AC) of 5V to 50V. Furthermore, the irradiated light can be, for example, ultraviolet light and visible light containing wavelengths from 150 nm to 800 nm, but ultraviolet light containing wavelengths from 300 nm to 400 nm is preferred. The light source for the irradiation can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonant lamp, a xenon lamp, an excimer laser, etc. In addition, the light source can be used in conjunction with filters, diffraction gratings, etc., to obtain ultraviolet light within the aforementioned preferred wavelength range.

[0166] The light irradiation intensity can range from 1000 J / m² to less than 100,000 J / m², preferably from 1000 J / m² to 50,000 J / m². For example, conventional manufacturing of PSA-mode liquid crystal display elements requires a light irradiation intensity of 100,000 J / m². However, the liquid crystal display element disclosed herein can utilize irradiation intensity less than 100,000 J / m², or even less than 50,000 J / m², to produce a liquid crystal display element with a predetermined pretilt angle characteristic and reduce the manufacturing cost of the liquid crystal display element. Furthermore, it can also suppress the degradation of electrical properties and the degradation of the reactivity of liquid crystal molecules caused by strong light irradiation.

[0167] Then, by attaching the polarizing plate to the outer surface of the liquid crystal cell, the liquid crystal display element disclosed herein can be obtained. The polarizing plate can be exemplified by a polarizing film called "H film" which is extended and aligned with polyvinyl alcohol and absorbs iodine solution, and a protective film of cellulose acetate sandwiched in between, forming a polarizing plate.

[0168] The liquid crystal display element disclosed herein can be used in various devices, such as watches, portable game consoles, word processors, laptops, navigation systems, cameras, PDAs, digital cameras, mobile phones, smartphones, various screens, LCD TVs, electronic billboards, and other display devices.

[0169] The following examples illustrate this disclosure in detail, but it is not intended to imply that this disclosure is limited to the content disclosed in these examples. [polymer] [(A)] [Preparation] [] [First polymer (A1)] <Synthesis Example A1-1>

[0170] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 0.0025 mol of a2-1-1, 0.025 mol of a2-2-1, 0.0225 mol of a2-2-2 (as shown in Table 1), and 80 g of NMP were added to the flask, and stirred at room temperature until dissolved. Next, 0.05 mol of a1-1 (as shown in Table 1) and 20 g of NMP were added. After reacting at room temperature for 6 hours, 97 g of NMP, 0.05 mol of acetic anhydride, and 0.1 mol of pyridine were added, and the temperature was raised to 120 °C and stirred continuously for 2 hours to carry out the acetylation reaction. After the reaction was complete, the reaction solution was poured into 1500 mL of water to allow the polymer to precipitate. Then, the obtained polymer was filtered, and the washing and filtration with methanol were repeated three times. The polymer was then placed in a vacuum oven and dried at 60°C to obtain polymer (A1-1). <Synthetic Examples A1-2 to A1-8>

[0171] Synthetic Examples A1-2 to A1-8 were prepared using the same steps as Synthetic Example A1-1, except that the type and amount of the tetracarboxylic dianhydride compound or diamine compound were changed, the amount of dehydrating agent and catalyst for the dehydration ring-closing reaction were changed, and the temperature of the acetylation reaction was changed, as shown in Table 1. [Second polymer (A2)] <Synthesis Example A2-1>

[0172] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 0.025 mol of a4-1, 0.025 mol of a4-2, and 80 g of N-methyl-2-pyrrolidone (NMP) were added to the flask and stirred at room temperature until dissolved. Next, 0.05 mol of a3-1 (as shown in Table 2) and 20 g of NMP were added, and the reaction was carried out at room temperature for 2 hours. After the reaction was complete, the reaction solution was poured into 1500 mL of water to allow the polymer to precipitate. The obtained polymer was then filtered, and the washing and filtration were repeated three times with methanol. The polymer was then dried in a vacuum oven at 60 °C to obtain polymer (A2-1). <Synthetic Examples A2-2 to A2-4>

[0173] Synthetic Examples A2-2 to A2-4 were prepared using the same steps as Synthetic Example A2-1, except that the type and amount of the tetracarboxylic dianhydride compound or diamine compound were changed, as shown in Table 2. Table 1: Ingredients (Unit: mole%) Synthesis example A1-1 A1-2 A1-3 A1-4 A1-5 A1-6 A1-7 A1-8 Tetracarboxylic acid dianhydride component (a1) a1-1 100 60 100 a1-2 100 60 100 100 a1-3 100 40 40 diamine component (a2) diamine compounds (a2-1) a2-1-1 5 60 3 a2-1-2 20 10 70 20 a2-1-3 40 Other diamine compounds (a2-2) a2-2-1 50 60 40 50 50 60 a2-2-2 45 50 40 47 20 a2-2-3 20 20 a2-2-4 10 10 Enylimine content (%) 53 62 76 82 93 66 83 0 aceimide ratio parameter Acetic anhydride (mole) 0.05 0.06 0.075 0.08 0.09 0.06 0.08 0 Pyridine (mole) 0.1 0.12 0.14 0.15 0.2 0.12 0.15 0 Temperature (°C) 120 120 120 120 105 120 120 0 Table 2: Ingredients (Unit: mole%) Synthesis example A2-1 A2-2 A2-3 A2-4 Tetracarboxylic dianhydride component (a3) a3-1 100 a3-2 100 50 a3-3 100 50 Diamine component (a4) a4-1 50 50 50 a4-2 50 60 50 a4-3 50 a4-4 40 Enylimine content (%) 0 0 0 0 Tables 1 and 2: a1-1 Benzyltetracarboxylic acid dianhydride a1-2 1,2,3,4-Cyclobutanetetracarboxylic Anhydride a1-3 2,3,5-Tricarboxycyclopentylacetic anhydride a2-1-1 a2-1-2 a2-1-3 a2-2-1 p-Diaminebenzene a2-2-2 4,4'-Diaminodiphenyl ether a2-2-3 4,4'-Diaminodiphenylmethane a2-2-4 2,2'-Dimethyl-4,4'-Diaminobiphenyl a3-1 Benzyltetracarboxylic acid dianhydride a3-2 1,2,3,4-Cyclobutanetetracarboxylic Anhydride a3-3 2,3,5-Tricarboxycyclopentylacetic anhydride a4-1 p-Diaminebenzene a4-2 4,4'-Diaminodiphenyl ether a4-3 4,4'-Diaminodiphenylmethane a4-4 2,2'-Dimethyl-4,4'-Diaminobiphenyl [Preparation of polysiloxanes] [(B)] <Synthetic Example B-1>

[0174] A stirrer, condenser, and thermometer were installed on a 500 mL three-necked flask. Then, 1.00 moles of b1-1-1 (as shown in Table 3-1) and 600 g of propylene glycol monomethyl ether (PGME) were added to the flask. Triethylamine (TEA) aqueous solution (20 g TEA / 200 g H₂O) was added over 30 minutes with stirring at room temperature. Next, the three-necked flask was immersed in a 30°C oil bath and stirred for 30 minutes. The oil bath temperature was then increased to 90°C over 30 minutes. When the internal temperature of the solution reached 75°C, heating and stirring were continued for 6 hours to induce polycondensation. After the reaction was complete, the organic layer was removed and washed with a 0.2 wt% ammonium nitrate aqueous solution to obtain a solution of isocyanate-containing polysiloxane.

[0175] Next, 0.50 moles of b2-2 (as shown in Table 3-2) and 0.2 g of curing accelerator UCAT 18X ​​(manufactured by SAN-APRO) were added to a solution of polysiloxane containing isocyanate groups. Then, a three-necked flask was immersed in an oil bath at 30°C and stirred for 10 minutes. The oil bath temperature was then increased to 115°C over 30 minutes. Once the internal temperature of the solution reached 100°C, heating and stirring were continued for 24 hours. After the reaction was complete, the organic layer was removed, washed with water, and dried with magnesium sulfate to remove the solvent, yielding polysiloxane (B-1). <Synthetic Examples B-2 to B-6 and Comparative Synthetic Examples B'-1 and B'-2>

[0176] Synthetic Examples B-2 to B-6 and Comparative Synthetic Examples B'-1 and B'-2 were prepared using the same steps as Synthetic Example B-1, with the difference being that the types and amounts of reactants, catalysts and solvents, reaction temperature and polycondensation time of the polysiloxane (B) were changed (as shown in Tables 3-1 and 3-2). Table 3-1: Polysiloxane (B) Step 1 Polysiloxanes containing isocyanate groups (b1) Silane monomer (b1-1) (mol) Other silane monomers (b1-2) (mol) Solvent (g) Catalyst (g) reaction temperature (°C) Polycondensation time (Hour) b1-1-1 b1-1-2 MTMS DMDMS PTMS PTES ECETS PGME MIBK water TEA B-1 1.00 600 200 20 75 6 B-2 0.90 0.10 600 200 20 75 6 B-3 0.80 0.20 600 200 20 75 6 B-4 0.70 0.10 0.20 600 200 20 70 6.5 B-5 0.60 0.20 0.20 800 250 22 80 6 B-6 0.50 0.50 600 200 250 25 85 5 B'-1 0.70 0.20 0.10 600 200 20 75 6 B'-2 1.00 800 250 twenty two 80 6 Table 3-2: Polysiloxane (B) Step 2 Compound (b2) (mol) Hardening accelerator (g) reaction temperature (°C) Polycondensation time (Hour) b2-1 b2-2 b2-3 UCAT 18X B-1 0.50 0.2 100 twenty four B-2 0.40 0.2 100 twenty four B-3 0.10 0.2 100 twenty four B-4 0.20 0.2 120 twenty four B-5 0.05 0.15 110 twenty four B-6 0.10 0.3 130 twenty two B'-1 - - - B'-2 0.10 0.2 100 twenty four In Tables 3-1 and 3-2: b1-1-1 3-Isocyanate-propyltriethoxysilane b1-1-2 3-Isocyanate-propyldiethoxymethylsilane MTMS Methyltrimethoxysilane DMDMS dimethyldimethoxysilane PTMS Phenylacetyltrimethoxysilane PTES Phenylacetoxysilane ECETS 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (2-(3,4-epoxycyclohexyl) ethyltrimethoxy silane) PGME Propylene glycol monomethyl ether MIBK Methylisobutylketone TEA Triethylamine b2-1 b2-2 b2-3 [Preparation of liquid crystal alignment agents, liquid crystal alignment films, and liquid crystal display elements] [] <Example 1>

[0177] Weigh 40 parts by weight of polymer (A1-1), 60 parts by weight of polymer (A2-1), 1 part by weight of polysiloxane (B-1), and 1500 parts by weight of N-methyl-2-pyrrolidone (C-1), and stir continuously with a stirrer at room temperature until dissolved to form the liquid crystal alignment agent of Example 1.

[0178] The liquid crystal alignment agent was evaluated by various tests, and the results are shown in Table 4-1. <Examples 2 to 11 and Comparative Examples 1 and 2>

[0179] Examples 2 to 11 and Comparative Examples 1 and 2 were prepared using the same steps as in Example 1, except that the types and amounts of the polymer, polysiloxane, solvent, and additives were changed, as shown in Tables 4-1 and 4-2. The liquid crystal alignment agents were evaluated using various tests, and the results are shown in Tables 4-1 and 4-2. Table 4-1: Ingredients Unit: parts by weight Example 1 2 3 4 5 6 7 polymer (A) A1-1 40 A1-2 50 50 A1-3 60 A1-4 70 A1-5 80 A1-6 50 A1-7 A1-8 A2-1 60 20 A2-2 50 50 50 A2-3 40 A2-4 30 Polysiloxane (B) B-1 1 B-2 5 5 B-3 10 B-4 20 B-5 30 B-6 5 Polysiloxane (B') B'-1 B'-2 solvent (C) C-1 1500 2000 2000 1000 2000 2000 C-2 500 1500 C-3 500 additive (D) D-1 1 D-2 1 Evaluation Project Trust ◎ ◎ ◎ ◎ ◎ ◎ ◎ LCD contact angle ◎ ◎ ◎ ◎ ◎ ○ ○ Table 4-2: Ingredients Unit: parts by weight Example Comparative example 8 9 10 11 1 2 polymer (A) A1-1 A1-2 30 50 50 A1-3 90 A1-4 A1-5 A1-6 A1-7 60 A1-8 40 A2-1 60 A2-2 70 50 50 A2-3 40 10 A2-4 Polysiloxane (B) B-1 1 B-2 5 B-3 10 10 B-4 B-5 B-6 Polysiloxane (B') B'-1 5 B'-2 5 solvent (C) C-1 2000 1500 2000 2000 2000 2000 C-2 C-3 additive (D) D-1 D-2 Evaluation Project Trust ◎ ○ ○ ○ ╳ ╳ LCD contact angle ○ ◎ ◎ ◎ ╳ ╳ Tables 4-1 and 4-2: C-1 N-Methyl-2-pyrrolidone C-2 Ethylene glycol n-butyl ether C-3 N,N-Dimethylacetamide D-1 N,N,N',N'-Tetracyclooxypropyl-4,4'-Diaminodiphenylmethane D-2 N,N-Epoxypropyl-p-epoxypropoxyaniline [Evaluation Method] [] [[] [Acetimation rate] []]

[0180] The amide ratio refers to the percentage of amide rings calculated based on the sum of the number of amide functional groups and the number of amide rings in a polymer.

[0181] The detection method involves drying the polymer components of the synthesized example under reduced pressure, dissolving them in a suitable deuteration solvent, such as deuterated dimethyl silane, using tetramethylsilane as a reference substance, and measuring the 1H-Nuclear magnetic resonance (1H-NMR) results at room temperature (e.g., 25°C). The amide imidization rate (%) can then be calculated using the following formula. Δ1: The peak area produced by the chemical shift of the NH proton near 10 ppm; Δ2: Peak area of ​​other protons; α: The ratio of one proton of the NH group to the number of other protons in the precursor (polyacrylic acid) of the polymer composition. [[] [Reliability] []]

[0182] The liquid crystal alignment agents of the examples and comparative examples were used to prepare liquid crystal alignment films, and liquid crystal display elements having the liquid crystal alignment films were fabricated. The liquid crystal display elements were placed in an environment with a temperature of 65°C and a relative humidity of 85% for reliability testing. After 120 hours, the voltage holding rate of the liquid crystal display elements was measured using an electrical measuring machine (Model 6254, manufactured by TOYO Corporation). The test conditions were as follows: a 4-volt voltage was applied for 2 milliseconds, and after a 1667-millisecond interval, the voltage holding rate was measured 1667 milliseconds after the application was removed. The results were evaluated according to the following criteria: ◎: Voltage retention rate > 98% ○: 95% < Voltage retention rate ≤ 98% △: 90% < Voltage retention rate ≤ 95% ╳: Voltage retention rate ≤ 90% [[] [Liquid crystal contact angle] []]

[0183] The aforementioned liquid crystal alignment agent was coated onto the transparent electrode surface of a glass substrate with an electrode structure on an ITO surface using a liquid crystal alignment film printing machine (manufactured by Nippon Shin-Kobo Co., Ltd.). A pre-baking treatment was then performed by heating at 80°C for 1 minute on a hot plate to remove the solvent. Subsequently, a post-baking treatment was performed by heating at 200°C for 10 minutes on a hot plate to form a coating with an average film thickness of 800 Å. 7 μl of MLC-2038 liquid crystal (manufactured by Merck) was dropped onto the substrate and left for 30 seconds. The contact angle was then measured using a contact angle measuring device (DropMaster 700, manufactured by Kyowa Interface Chemicals) using the θ / 2 method, with the measurement standards as follows: ◎:LCD contact angle ≤13° ○:13°<LCD contact angle≤15° △:15°<LCD contact angle≤18° ╳: Liquid crystal contact angle>18°.

[0184] The above embodiments are merely illustrative of the principles and effects of this disclosure and are not intended to limit the scope of this disclosure. Modifications and variations made to the above embodiments by those skilled in the art will not depart from the spirit of this disclosure. The scope of this invention should be as set forth in the following claims.

Claims

1. A liquid crystal alignment agent, comprising: a polymer (A), comprising a first polymer (A1), the first polymer (A1) being prepared by reacting a first mixture, the first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamide polymers, polyimide polymers, polyimide-based block copolymers, or combinations thereof; a polysiloxane (B), prepared by reacting an isocyanate-containing polysiloxane (b1) with a compound (b2), wherein the isocyanate-containing polysiloxane (b1) is a copolymer obtained by polycondensation of a third mixture, the third mixture comprising a silane monomer (b1-1), the silane monomer (b1-1) comprising 3-isocyanopropyltriethoxysilane or 3-isocyanopropyldiethoxymethylsilane; and a solvent (C); in, Compound (b2) comprises the structure of formula (V): Formula (V) In formula (V): E1 is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms substituted with or unsubstituted by an alkyl or alkoxy group having 1 to 20 carbon atoms, or a hydrocarbon group having 17 to 51 carbon atoms containing a steroid skeleton, wherein some hydrogen atoms of the alkyl and alkoxy groups of E1 are substituted or unsubstituted; L0 is a single bond, *1-O-, *1-COO-, or *1-OCO-, where *1 represents the bond with E1; L1 is a single bond, an alkyl group having 1 to 20 carbon atoms ... or a group having 1 to 20 carbon atoms, an alkyl group having 1 to 2 Where *2 represents the bond with Z; and when L1 is a single bond, L0 is a single bond, and Z is a carboxyl group that reacts with the isocyanate group to form a binding group; the amount of the polymer (A) used is 100 parts by weight, the amount of the polysiloxane (B) used is 1 to 30 parts by weight, and the amount of the solvent (C) used is 500 to 3000 parts by weight.

2. The liquid crystal alignment agent as claimed in claim 1, wherein the diamine component (a2) comprises a diamine compound (a2-1) of formula (II), wherein: R15 represents a group selected from , , , , and ; and R16 represents an organic group of formula (II-1): wherein: R17 represents hydrogen, fluorine, or methyl; R18, R19, and R20 each independently represent a single bond, alkyl, fluoroalkyl, or alkyl group having 1 to 3 carbon atoms; R21 is selected from the group consisting of -OCH2F, -OCHF2, and -OCF3; wherein: R23 and R24 each independently represent hydrogen, fluorine, or methyl; R22 is selected from the group consisting of hydrogen, fluorine, alkyl group having 1 to 12 carbon atoms, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, -OCH2F, -OCHF2, and -OCF3; a represents an integer of 1 or 2; g, m, and i each independently represent an integer of 0 to 4; y, h, and x each independently represent an integer of 0 to 3, and y+h+x≧2; and z1 and z2 each independently represent 1 or 2; when there are multiple R17, R18, R19, R20, R21, R23, or R24, they may each be the same or different.

3. The liquid crystal alignment agent as claimed in claim 1, wherein, Based on the total amount of silane monomer in the third mixture being 1 mol, the amount of silane monomer (b1-1) used being 0.6 mol to 1 mol, and the amount of compound (b2) used being 0.05 mol to 0.5 mol.

4. The liquid crystal alignment agent as claimed in claim 1, wherein, The amide content of the polymer (A) is 30% to 80%.

5. A liquid crystal alignment film formed from any one of claims 1 to 4.

6. A liquid crystal display element comprising the liquid crystal alignment film described in claim 5.

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