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

Abstract

The invention relates to a liquid crystal alignment agent with good reliability and low liquid crystal contact angle, a liquid crystal alignment film and a liquid crystal display element. The liquid crystal alignment agent comprises: 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 a polyamic acid polymer, a polyimide polymer, a polyimide-based block copolymer or a combination of the polyamic acid polymer, the polyimide polymer and the polyimide-based block copolymer; the polysiloxane (B) is prepared by reacting polysiloxane (b1) containing an isocyanate group with a compound (b2), and the polysiloxane (b1) containing the isocyanate group is prepared by carrying out polycondensation on 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. Background 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, or polysiloxane.

[0003] In recent years, new technologies such as polymer-stable alignment (PSA) have been proposed to control the alignment of liquid crystal molecules in liquid crystal display elements. 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. Under the condition of applying voltage, the liquid crystal molecules are tilted, and then the liquid crystal cell is irradiated with light, thereby causing the photopolymerizable component to polymerize, thereby controlling the alignment of 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 containing (meth)acryloyl groups and photopolymerizable components such as polyimide or polyimide 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), comprising a first polymer (A1), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamic acid polymers, polyimide polymers, polyimide block copolymers or combinations thereof; Polysiloxane (B), 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): E 1 It is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms substituted with or unsubstituted with 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, E 1 Some of the hydrogen atoms in the alkyl and alkoxy groups are substituted or unsubstituted; L 0 For single bond, , or ,in Representative and E 1 At the junction; L 1 It is a single bond, and the carbon number is 1 to 20. It is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group represented by the following formula (V-1) or formula (V-2): Equation (V-1) Equation (V-2) in Represents the bond with Z; and when L 1 When it is a single bond, L 0 Z 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(Ra ) c (OR b ) 4-c Formula (VI-1) In formula (VI-1): R a It 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, an isocyanate group having 1 to 10 carbon atoms, and at least one R a It contains isocyanate groups with 1 to 10 carbon atoms; when R a For complex numbers, each R a Same or different; R b Represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; when R b For complex numbers, each R b 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) represented by formula (II). Equation (II) In formula (II): R 15 Indicates freedom of choice , , , , and The group formed; and R 16 The organic group represented by formula (II-1): Equation (II-1) in: R 17 Indicates hydrogen, fluorine, or methyl; R 18 R 19 and R 20 Each independently represents a single bond. , , , , , Or alkyl groups having 1 to 3 carbon atoms; R 21 Is it freedom to choose? and The group formed; in: R 23 and R 24 Each can independently represent hydrogen, fluorine, or methyl; R 22 It is a group composed 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, -OCH2F, -OCHF2 and -OCF3; a represents an integer of 1 or 2; g, m, and i each independently represent integers from 0 to 4; Let 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 R 17 R 18 R 19 R 20 R 21 R 23 or R 24 When there are multiple, each can be the same or different.

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

[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 imidization rate 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 that includes the liquid crystal alignment film. Detailed Implementation

[0016] This disclosure provides a liquid crystal alignment agent comprising: Polymer (A), comprising a first polymer (A1), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamic acid polymers, polyimide polymers, polyimide block copolymers or combinations thereof; Polysiloxane (B), 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): E 1 It is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms substituted with or unsubstituted with 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, E 1 Some of the hydrogen atoms in the alkyl and alkoxy groups are substituted or unsubstituted; L 0 For single bond, , or ,in Representative and E 1 At the junction; L 1 It is a single bond, and the carbon number is 1 to 20. It is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group represented by the following formula (V-1) or formula (V-2): Equation (V-1) Equation (V-2) in Represents the bond with Z; and when L 1 When it is a single bond, L 0 Z 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.

[0018] Polymer (A) First polymer (A1) 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 polyamic acid polymers, polyimide polymers, polyimide-based 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, ethanetetracarboxylic 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, benzyl tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl sulfone 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 sulfone 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-Tetrahydrofurantetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxy-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-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxy-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-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 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; A 2 and A 3 They may be the same or different, and each may independently represent a hydrogen atom or an alkyl group. Specific examples of tetracarboxylic dianhydrides 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; A 5 and A 6 These can be the same or different, and each can independently represent 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'-biphenyl sulfone tetracarboxylic dianhydride, compounds represented by formula (I-1), or combinations of the above compounds.

[0029] Based on a total molar amount of 100 moles of diamine component (a2), the amount of tetracarboxylic acid dianhydride component (a1) used is preferably 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 freedom of choice , , , , and The group formed; and Equation (II-1) in: R 17 Indicates hydrogen, fluorine, or methyl; R 18 R 19 and R 20 Each independently represents a single bond. , , , , , Or alkyl groups having 1 to 3 carbon atoms; R 21 Is it freedom to choose? and The group formed; in: R 23 and R 24 Each can independently represent hydrogen, fluorine, or methyl; R 22 It is a group composed 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, -OCH2F, -OCHF2 and -OCF3; a represents an integer of 1 or 2; g, m, and i each independently represent integers from 0 to 4; Let 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 R 17 R 18 R 19 R 20 R 21 R 23 or R 24 When there are multiple, each 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.

[0032] 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).

[0033] In equations (II-2) to (II-10), B 11 It is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0034] 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.

[0035] Equation (II-11) Equation (II-12) Equation (II-13) Equation (II-14) Equation (II-15) Equation (II-16) Equation (II-17).

[0036] The aforementioned diamine compound (a2-1) can be used alone or in combination.

[0037] 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.

[0038] Preferably, the diamine component (a2) disclosed herein may further comprise other diamine compounds (a2-2).

[0039] 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, tricyclo(6.2.1.0) 2,74,4'-Undecenedimethyldiamine, 4,4'-Methylenebis(cyclohexylamine), 4,4'-Diaminodiphenylmethane, 4,4'-Diaminodiphenylethane, 4,4'-Diaminodiphenylsulfone, 4,4'-Diaminobenzoylaniline, 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-bridged indene dimethylenediamine, 3,3'-diaminobenzophenone, 3,4'-di... Aminobenzophenone, 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]sulfone, 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).

[0040] The diamine compounds represented by formula (III-1) are shown below: Equation (III-1).

[0041] 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.

[0042] The diamine compound represented by formula (III-1) above is preferably 2,4-diaminophenyl ethyl formate, 3,5-diaminophenyl ethylformate, 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 represented by 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).

[0043] The diamine compounds represented by formula (III-2) are shown below: Equation (III-2).

[0044] In equation (III-2), X 12 The X represents a hydrogen atom, an acyl 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 X in each repeating unit 12 They can be the same or different. X 13 It is an integer from 1 to 3.

[0045] The diamine compound represented by formula (III-2) is preferably selected from (1)X 13 1: p-Diaminebenzene, m-Diaminebenzene, o-Diaminebenzene or 2,5-Diaminetoluene, etc.; (2) X 13 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 The form is 3:1,4-bis(4'-aminophenyl)benzene, more preferably selected from p-diaminobenzene, 2,5-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl or 1,4-bis(4'-aminophenyl)benzene.

[0046] The diamine compounds represented by formula (III-3) are shown below: Equation (III-3).

[0047] In equation (III-3), X 14 Represents integers from 2 to 12.

[0048] The diamine compounds represented by formula (III-4) are shown below: Equation (III-4).

[0049] In equation (III-4), X 15 Represents an integer from 1 to 5. Formula (III-4) is preferably selected from 4,4'-diaminodiphenyl sulfide.

[0050] The diamine compounds represented by formula (III-5) are shown below: Equation (III-5).

[0051] In equation (III-5), X 16 and X 18 They can be the same or different, and each represents a divalent organic group, X 17 It represents a divalent group derived from nitrogen-containing cyclic structures such as pyridine, pyrimidine, triazine, piperidine, and piperazine.

[0052] The diamine compounds represented by formula (III-6) are shown below: Equation (III-6).

[0053] In equation (III-6), X 19 X 20 X 21 and X 22 These can be the same or different, and can represent hydrocarbon groups with 1 to 12 carbon atoms. X 23 Represents integers from 1 to 3, and X 24 Represents integers from 1 to 20.

[0054] The diamine compounds represented by formula (III-7) are shown below: Equation (III-7).

[0055] In equation (III-7), X 25 represent Or extended cyclohexyl, X 26 Represents -CH2-, X 27 Represents phenyl or cyclohexyl, and X 28 It represents a hydrogen atom or a heptyl group.

[0056] 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) below: Equation (III-7-1) Equation (III-7-2).

[0057] 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)

[0058] Equation (III-20) Equation (III-21) Equation (III-22) Equation (III-23) Equation (III-24).

[0059] In formulas (III-16) to (III-24), X29 is preferably an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, while X30 is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0060] 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).

[0061] The other diamine compounds (a2-2) mentioned above can be used alone or in combination.

[0062] In the specific example disclosed herein, the total amount of the diamine component (a2) used is 100 moles, and the amount of the other diamine compound (a2-2) used is 40 to 95 moles, preferably 50 to 92 moles, and more preferably 60 to 90 moles.

[0063] Second polymer (A2) 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 polyamic acid polymers, polyimide polymers, polyimide-based block copolymers, and any combination thereof. Preferably, the second polymer (A2) is a polyamic acid polymer.

[0064] 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 as the tetracarboxylic dianhydride component (a1), 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.

[0065] Based on a total molar amount of 100 moles of diamine component (a4), the amount of tetracarboxylic acid dianhydride component (a3) ​​used is preferably 80 to 120 moles, more preferably 85 to 115 moles.

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The imidization rate of the polymer (A) can be 30% to 80%, preferably 35% to 80%, and even more preferably 45% to 75%. If the imidization rate of the polymer (A) falls within the above range, the reliability of the prepared liquid crystal alignment agent is better.

[0071] Preparation method of polymer (A) 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 polyamic acid polymers, polyimide polymers, polyimide-based block copolymers, and any combination thereof. The following further describes methods for preparing polyamic acid polymers, polyimide polymers, and polyimide-based block copolymers using the first mixture, taking the first polymer (A1) as an example. 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.

[0072] [Preparation method of polyamic acid polymer] The method for preparing this polyamic acid 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 polyamic acid. Alternatively, the reaction solution is poured into a large amount of lean solvent to obtain a precipitate. The precipitate is then dried under reduced pressure to obtain polyamic acid.

[0073] 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, 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 hexamethylphosphonic 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.

[0074] It is worth noting that in the polycondensation reaction, solvents can be used in combination with appropriate amounts of lean solvents, where the lean solvent will not cause polyamic acid precipitation. Lean solvents can be used alone or in combination, and include, but are 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 dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichlorobenzene; or (6) 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.

[0075] [Preparation method of polyimide polymer] The method for preparing this polyimide polymer involves heating the polyamic acid prepared by the above-described method in the presence of a dehydrating agent and a catalyst. During the heating process, the amic acid functional groups in the polyamic acid can be converted into imide functional groups via a dehydration and ring-closing reaction (i.e., imidization).

[0076] 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 polyamic 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.

[0077] To obtain a better degree of imidization of polyamic acid, 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 imidization reaction is incomplete, thus reducing the degree of imidization of the polyamic acid. 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.

[0078] 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 1 mole of polyamic acid, 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; (2) tertiary amine compounds, such as triethylamine. Based on 1 mole of dehydrating agent used, the amount of catalyst used can be 0.5 mole to 10 moles.

[0079] [Preparation method of polyimide block copolymers] The polyimide-based block copolymer is selected from polyamic acid block copolymers, polyimide block copolymers, polyamic acid-polyimide block copolymers, or any combination of the above polymers.

[0080] 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 polyamic acid and / or at least one polyimide, and may further include a carboxylic anhydride component and a diamine component.

[0081] 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 polyamic acid, 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.

[0082] 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.

[0083] The starting materials are preferably including, but not limited to, (1) two polyamic acids with different terminal groups and different structures; (2) two polyimides with different terminal groups and different structures; (3) polyamic acid and polyimide with different terminal groups and different structures; (4) polyamic acid, 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 polyamic acid; (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) polyamic acid, polyimide, a carboxylic anhydride component, and (7) Two structurally different polyamic acid, carboxylic anhydride and diamine components; (8) Two structurally different polyimide, carboxylic anhydride and diamine components; (9) Two structurally different polyamic acid and diamine components with an anhydride end group; (10) Two structurally different polyamic acid and carboxylic anhydride end group; (11) Two structurally different polyimide and diamine components with an anhydride end group; or (12) Two structurally different polyimide and carboxylic anhydride end group.

[0084] Without affecting the effectiveness of this disclosure, polyamic acid, polyimide, and polyimide-based block copolymers are preferably end-modified polymers after prior molecular weight adjustment. 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 polyamic acid.

[0085] 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.

[0086] Polysiloxane (B) The polysiloxane (B) disclosed herein is prepared by reacting a polysiloxane (b1) containing isocyanate groups with a compound (b2).

[0087] Polysiloxanes containing isocyanate groups (b1) The isocyanate-containing polysiloxane (b1) is a copolymer obtained by polycondensation of a third mixture, preferably a copolymer obtained by hydrolysis and partial condensation.

[0088] 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): R a It 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, an isocyanate group having 1 to 10 carbon atoms, and at least one R a It contains isocyanate groups with 1 to 10 carbon atoms; when R a For complex numbers, each R a Same or different; R b Represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; when R b For complex numbers, each R b Same or different; and c represents an integer from 1 to 3.

[0089] More specifically, when R in equation (VI-1) a When referring to alkyl groups having 1 to 10 carbon atoms, specifically, R a Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, tributyl, n-hexyl, or n-decyl. Also, R a It can also be an alkyl group with other substituents, specifically, R a Examples include trifluoromethyl, 3,3,3-trifluoropropyl, 3-aminopropyl, or 3-mercaptopropyl.

[0090] When R in equation (VI-1) a When representing alkenes with 2 to 10 carbon atoms, specifically, R a For example, vinyl. Also, R a It can also be an alkenyl group with other substituents, specifically, R a For example, it is 3-acryloyloxypropyl or 3-methacryloyloxypropyl.

[0091] When Ra in formula (VI-1) represents an aryl group with 6 to 15 carbon atoms, specifically, R a For example, it can be phenyl, tolyl, or naphthyl. Also, Ra It can also be an aryl group with other substituents, specifically, R a For example, o-hydroxyphenyl, 1-(o-hydroxyphenyl)ethyl, 2-(o-hydroxyphenyl)ethyl or 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyl.

[0092] When R in equation (VI-1) a When representing isocyanate groups with 1 to 10 carbon atoms, specifically, R a For example, 3-isocyanate propyl.

[0093] Additionally, when R in equation (VI-1) b When referring to alkyl groups having 1 to 6 carbon atoms, specifically, R b For example, it can be methyl, ethyl, n-propyl, isopropyl, or n-butyl. When R in formula (VI-1) b When representing an acyl group with 1 to 6 carbon atoms, specifically, R b For example, it is an acetyl group. When R in formula (VI-1) b When representing aryl groups with 6 to 15 carbon atoms, specifically, R b For example, it is phenyl.

[0094] Specific examples of silane monomers (b1-1) include 3-Isocyanatopropyl triethoxy silane and 3-Isocyanatopropyl diethoxy methyl silane.

[0095] Based on the total amount of monomers in the third mixture being 1 mole, the amount of silane monomer (b1-1) used is 0.6 moles to 1 mole, preferably 0.7 moles to 1 mole, and more preferably 0.8 moles to 1 mole. 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.

[0096] The third mixture may also contain other silane monomers (b1-2) represented by formula (VI-2): Si(R h ) f (OR i ) 4-f Formula (VI-2) In equation (VI-2): R h It 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 h Each can be the same or different; R i It is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; When 4-f is a complex number, R i Each is the same or different; and f is an integer from 1 to 3.

[0097] 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 in the aforementioned Ra, and will not be repeated here.

[0098] 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.

[0099] Formula (VI-2-1) Equation (VI-2-2) Formula (VI-2-3) When R in equation (VI-2) i When referring to an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms, specific examples and preferred examples are shown in the aforementioned Rb, and will not be repeated here.

[0100] 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.

[0101] Specific examples of silane compounds having four hydrolyzable groups include tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetran-propoxysilane, tetraisopropoxysilane, tetran-butoxysilane, tetradibutoxysilane, or combinations thereof.

[0102] 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 succinic anhydride (trade name GF-20); 3-(trimethoxysilyl)propyl glutaric anhydride (TMSG); 3-(triethoxysilyl)propyl glutaric anhydride; 3-(triphenoxysilyl)propyl glutaric anhydride; or combinations thereof.

[0103] Specific examples of silane compounds having two hydrolyzable groups include methyldimethoxysilane, methyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyl[2-(perfluoron-octyl)ethyl]dimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiacetoxysilane, di-n-butyldimethoxysilane, or combinations thereof.

[0104] Specific examples of silane compounds having one hydrolyzable group include methoxydimethylsilane, methoxytrimethylsilane, methoxymethyldiphenylsilane, tri-n-butylethoxysilane, or combinations thereof.

[0105] 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 thereof.

[0106] Based on the total amount of monomers in the third mixture being 1 mole, the amount of silane monomer (b1-2) used is 0 to 0.4 moles, preferably 0 to 0.3 moles, and more preferably 0 to 0.2 moles.

[0107] 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.

[0108] Preparation method of isocyanate-containing polysiloxane (b1) 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.

[0109] 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.

[0110] 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, hexamethylphosphotriamide, 1,3-dimethyl-2-imidazolidinedione, etc., or combinations of the above organic solvents.

[0111] The above-mentioned organic solvents can be used alone or in combination.

[0112] 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.

[0113] The amount of water used is preferably 0.5 to 2 moles, based on the fact that the hydrolyzable group of the third mixture is 1 mole.

[0114] 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.

[0115] 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.

[0116] Specific examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, or combinations thereof.

[0117] 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.

[0118] The amount of catalyst used varies depending on the type, temperature, and other reaction conditions, and can be set appropriately. For example, based on 1 mole of all silane compounds, the amount of catalyst added is 0.01 moles to 5 moles, preferably 0.03 moles to 3 moles, and more preferably 0.05 moles to 1 mole.

[0119] 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 a desiccant such as anhydrous calcium sulfate or molecular sieves to remove the organic solvent, thus obtaining the isocyanate-containing polysiloxane (b1).

[0120] Compound (b2) The compound (b2) contains a structure of formula (V): Formula (V) In formula (V): E 1 It is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms substituted with or unsubstituted with 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, E 1 Some of the hydrogen atoms in the alkyl and alkoxy groups are substituted or unsubstituted; L 0 For single bond, , or ,in Representative and E 1 At the junction; L 1 It is a single bond, and the carbon number is 1 to 20. It is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group represented by the following formula (V-1) or formula (V-2): Equation (V-1) Equation (V-2) in Represents the bond with Z; and when L 1 When it is a single bond, L 0 It is a single bond; Z is a monovalent organic group that reacts with isocyanate groups to form a binding group.

[0121] E in the above formula (V) 1The alkyl group having 1 to 30 carbon atoms may be linear or branched, and for example, may be 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.

[0122] E in the above formula (V) 1 The cycloalkyl group having 3 to 10 carbon atoms may, for example, be cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc. These cycloalkyl groups may or may not be substituted with an alkoxy group having 1 to 20 carbon atoms. Specific examples of alkoxy groups 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 alkoxy groups 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, after the alkyl group is combined with an oxygen atom. 1 The alkyl and alkoxy groups may have at least some of their hydrogen atoms substituted, and the groups used to substitute the hydrogen atoms may be, for example, nitrile groups, fluorine atoms, trifluoromethyl groups, etc.

[0123] E in the above formula (V) 1 The hydrocarbon group containing a steroid skeleton having 17 to 51 carbon atoms may, for example, be a group represented by formulas (S-1) to (S-3), wherein L representing the above groups and formula (V) 0 The key junction.

[0124] Equation (S-1) Equation (S-2) Equation (S-3) Ideally, E 1 It 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.

[0125] L in the above formula (V) 1 The alkyl group having 1 to 20 carbon atoms, for example, can be a group obtained by removing one hydrogen atom from each of the aforementioned alkyl groups having 1 to 30 carbon atoms.

[0126] In the above formula (V), Z is preferably a carboxyl group.

[0127] The compound represented by formula (V) is preferably a compound represented by formulas (V-3) to (V-10): Equation (V-3) Equation (V-4) Equation (V-5) Equation (V-6) Equation (V-7) Equation (V-8) Equation (V-9) Equation (V-10).

[0128] 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.

[0129] 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.

[0130] 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').

[0131] 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.

[0132] Based on the total amount of monomers in the third mixture being 1 mole, the amount of compound (b2) used is 0.05 moles to 0.5 moles, preferably 0.1 moles to 0.45 moles, but more preferably 0.2 moles to 0.4 moles. 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.

[0133] 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.

[0134] Preparation method of polysiloxane (B) 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.

[0135] 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.

[0136] The aforementioned organic salts may 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.

[0137] 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] 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, tetraphenylphosphonium tetraphenylborate, etc.[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; and latent curing accelerators such as Lewis acids and Bronsted acidsalts that undergo high-temperature dissociation and thermal cationic polymerization.

[0138] Preferred examples of curing accelerators are quaternary ammonium salts including tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride.

[0139] Preferred examples of curing accelerators are quaternary ammonium salts including tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride.

[0140] 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.

[0141] 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.

[0142] The polysiloxane (B) disclosed herein has a weight average molecular weight of 2,000 to 20,000; more preferably 3,000 to 18,000; and even more preferably 5,000 to 15,000.

[0143] 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 without reacting with them. Preferably, it is the same solvent used in the synthesis of polyamic acid as described above. At the same time, the lean solvent used in the synthesis of the polyamic acid can also be used.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] Compounds with at least two epoxy 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 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.

[0150] 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.

[0151] Silane compounds with functional groups can be used alone or in combination.

[0152] 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.

[0153] 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.

[0154] Method for manufacturing liquid crystal alignment agents 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.

[0155] 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.

[0156] Manufacturing method of liquid crystal alignment film and liquid crystal display element This disclosure also provides a liquid crystal alignment film formed from the aforementioned liquid crystal alignment agent.

[0157] This disclosure also provides a liquid crystal display element comprising the aforementioned liquid crystal alignment film.

[0158] The liquid crystal alignment film disclosed herein is formed using the above-described modulated liquid crystal alignment agent. Furthermore, the liquid crystal display element disclosed herein has a liquid crystal alignment film formed from the above-described liquid crystal alignment agent. The operating mode of the liquid crystal display element is not particularly limited, but a vertical alignment type is preferred.

[0159] 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 a voltage to the liquid crystal cell.

[0160] [Step 1: Coating Formation] 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 coating of the liquid crystal alignment agent can be performed 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 the patterned transparent conductive film can be achieved, for example, by first forming an unpatterned transparent conductive film and then using a photo-etching pattern forming method, and using a mask with a predetermined pattern from the formation of the transparent conductive film. When applying liquid crystal alignment agents, in order to ensure good adhesion between the substrate surface and the transparent conductive film and the coating, a pretreatment such as coating with functional silane compounds or functional titanium compounds can be performed on the surface of the substrate to form the coating.

[0161] 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, and even 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 acid structure through thermal 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.

[0162] The heating step following the application of the liquid crystal alignment agent removes the organic solvent, thus forming a liquid crystal alignment film. At this point, the polymer contained in the liquid crystal alignment agent disclosed herein includes polyamic acid, or an imide polymer having an imide structure and an amic acid structure. Subsequently, the formed coating is further heated, causing the polymer to undergo a dehydration and ring-closing reaction to form an imidized 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.

[0163] [Step 2: Construction of Liquid Crystal Cells] 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.

[0164] The first method is the conventional method (vacuum injection). First, two substrates are placed opposite each other, forming a gap (cell gap) between the opposing liquid crystal alignment films. The two substrates are then bonded together with an adhesive. Liquid crystal compound and photopolymerizable compound are injected into and filled into the cell gap defined by the substrate surfaces and the adhesive. The injection hole is then sealed to obtain a liquid crystal cell.

[0165] The second method is called One Drop Filling (ODF). A UV-curable adhesive, for example, is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed. 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 of 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, thereby creating liquid crystal cells. Regardless of which method is 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.

[0166] As the aforementioned adhesive, an 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 improve the response speed of the PSA mode liquid crystal display device, an alkenyl liquid crystal, which is a monofunctional liquid crystal compound having one alkenyl or fluoroalkenyl group, is preferably used. The alkenyl liquid crystal can be a conventional alkenyl liquid crystal, such as compounds shown in formulas (L1-1) to (L1-9).

[0167]

[0168] The photopolymerizable compound can be a compound having functional groups such as acryloyl, methacryl, or vinyl groups that are capable of free radical polymerization. From a reactivity point of view, a compound having at least two functional groups selected from acryloyl and methacryl groups is preferred. Furthermore, from the viewpoint of maintaining the alignment stability of the 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 rings 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.

[0169] [Step 3: Exposure Step] 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.

[0170] The light irradiation can be 1000 J / m. 2 Above to less than 100,000 J / m 2 The optimal value is 1000 J / m 2 Up to 50,000 J / m 2 For example, it is known that 100,000 J / m is required when manufacturing PSA-mode liquid crystal display elements. 2 The light irradiation intensity is less than 100,000 J / m², however, the liquid crystal display element disclosed herein can utilize light irradiation intensity less than 100,000 J / m². 2 Even less than 50,000 J / m 2 By controlling the amount of light irradiated, liquid crystal display elements with predetermined pretilt angle characteristics can be obtained, and the manufacturing cost of liquid crystal display elements can be reduced. 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] Preparation of polymer (A) [First polymer (A1)] <Synthesis example A1-1> 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 imidization reaction. After the reaction was complete, the reaction solution was poured into 1500 mL of water to precipitate the polymer. The obtained polymer was then filtered, washed with methanol, and filtered three times. It was then placed in a vacuum oven and dried at 60 °C to obtain polymer (A1-1).

[0175] <Synthetic Examples A1-2 to A1-8> 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 acid 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 imidization reaction was changed, as shown in Table 1.

[0176] [Second polymer (A2)] <Synthesis Example A2-1> 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 until dissolved at room temperature. Next, 0.05 mol of a3-1 (as shown in Table 2) and 20 g of NMP were added, and the mixture was reacted 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 mixture was washed with methanol and filtered three times. It was then placed in a vacuum oven and dried at 60 °C to obtain polymer (A2-1).

[0177] <Synthetic Examples A2-2 to A2-4> 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 or diamine compound were changed, as shown in Table 2.

[0178] Table 1:

[0179] Table 2:

[0180] Tables 1 and 2: a1-1 Benzymite dicarboxylic acid dianhydride a1-2 1,2,3,4-cyclobutanetetracarboxylic dianhydride a1-3 2,3,5-Tricarboxycyclopentylacetic anhydride a2-1-1

[0181] a2-1-2

[0182] a2-1-3

[0183] 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 Benzymium tetracarboxylic 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 polysiloxane (B) <Synthetic Example B-1> A stirrer, condenser, and thermometer were installed on a 500 mL three-necked flask. Then, 1.00 mol 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.

[0184] Next, 0.50 mol 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).

[0185] <Synthetic Examples B-2 to B-6 and Comparative Synthetic Examples B'-1 and B'-2> 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).

[0186] Table 3-1:

[0187] Table 3-2:

[0188] In Tables 3-1 and 3-2: b1-1-1 3-Isocyanate-propyltriethoxysilane b1-1-2-3-Isocyanate-propyldiethoxymethylsilane MTMS (methyltrimethoxysilane) DMDMS (dimethyldimethoxysilane) PTMS (phenyltrimethoxysilane) PTES (phenyltriethoxysilane) ECETS 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane PGME (Propylene Glycol Monomethyl Ether) MIBK (Methylisobutylketone) TEA (triethylamine) b2-1

[0189] b2-2

[0190] b2-3

[0191] Preparation of liquid crystal alignment agents, liquid crystal alignment films and liquid crystal display elements <Example 1> 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.

[0192] The liquid crystal alignment agent was evaluated by various tests, and the results are shown in Table 4-1.

[0193] <Examples 2 to 11 and Comparative Examples 1 and 2> Examples 2 to 11 and Comparative Examples 1 and 2 were prepared using the same procedures 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.

[0194] Table 4-1:

[0195] Table 4-2:

[0196] In Tables 4-1 and 4-2: C-1 N-methyl-2-pyrrolidone C-2 Ethylene glycol n-butyl ether C-3N,N-Dimethylacetamide D-1 N,N,N',N'-Tetracyclooxypropyl-4,4'-Diaminodiphenylmethane D-2 N,N-Epoxypropyl-p-Epoxypropoxyaniline Evaluation method [Imidification rate] The imidization rate refers to the percentage of imide rings calculated based on the sum of the number of ammonium functional groups and the number of imide rings in a polymer.

[0197] The detection method involves drying the polymer components of the synthesized examples under reduced pressure, dissolving them in a suitable deuteration solvent, such as deuterated dimethyl sulfoxide, using tetramethylsilane as a reference substance, and measuring at room temperature (e.g., 25°C). 1 The imidization rate (%) can be obtained from the results of 1H-Nuclear magnetic resonance (1H-NMR) using the following formula.

[0198]

[0199] Δ1: The peak area produced by the chemical shift of NH protons near 10 ppm; Δ2: Peak area of ​​other protons; α: The ratio of one proton of the NH group in the precursor (polyamic acid) of the polymer composition to the number of other protons.

[0200] [Reliability] 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, with a span of 1667 milliseconds. The voltage holding rate was measured 1667 milliseconds after the application was removed, and evaluated according to the following criteria: ◎: Voltage retention rate > 98% ○: 95% < Voltage retention rate ≤ 98% △: 90% < Voltage retention rate ≤ 95% X: Voltage retention rate ≤ 90% [Liquid crystal contact angle] The aforementioned liquid crystal alignment agent was coated onto the transparent electrode surface of a glass substrate with an electrode structure on the 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: ◎: Liquid crystal contact angle ≤13° ○: 13°<LCD contact angle≤15° △: 15°<LCD contact angle≤18° ╳: Liquid crystal contact angle >18°.

[0201] 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 do 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: Polymer (A), comprising a first polymer (A1), the first polymer (A1) being prepared by reacting a first mixture comprising a tetracarboxylic dianhydride component (a1) and a diamine component (a2), wherein the first polymer (A1) is selected from polyamic acid polymers, polyimide polymers, polyimide block copolymers or combinations thereof; Polysiloxane (B), prepared by reacting isocyanate-containing polysiloxane (b1) with compound (b2), wherein the isocyanate-containing polysiloxane (b1) is a copolymer obtained by polycondensation of a third mixture; and Solvent (C); in, The compound (b2) contains a structure of formula (V): Formula (V) In formula (V): E 1 It is an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms substituted with or unsubstituted with 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, E 1 Some of the hydrogen atoms in the alkyl and alkoxy groups are substituted or unsubstituted; L 0 For single bond, , or ,in Representative and E 1 At the junction; L 1 It is a single bond, and the carbon number is 1 to 20. It is an alkyl group, phenyl group, biphenyl group, cyclohexyl group, dicyclohexyl group, or a group represented by the following formula (V-1) or formula (V-2): Equation (V-1) Equation (V-2) in Represents the bond with Z; and when L 1 When it is a single bond, L 0 Z is a single bond, and Z is a monovalent organic group that reacts with the isocyanate group to form a binding group.

2. The liquid crystal alignment agent as described in claim 1, wherein, 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): R a It 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, an isocyanate group having 1 to 10 carbon atoms, and at least one R a It contains isocyanate groups with 1 to 10 carbon atoms; when R a For complex numbers, each R a Same or different; R b Represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms; when R b For complex numbers, each R b Same or different; and c represents an integer from 1 to 3.

3. The liquid crystal alignment agent as described in claim 2, wherein, The silane monomer (b1-1) contains 3-isocyanopropyltriethoxysilane or 3-isocyanopropyldiethoxymethylsilane.

4. The liquid crystal alignment agent according to claim 1, wherein the diamine component (a2) comprises the diamine compound (a2-1) represented by formula (II). Equation (II) In formula (II): R 15 Indicates freedom of choice , , , , and The group formed; and R 16 The organic group represented by formula (II-1): Equation (II-1) in: R 17 Indicates hydrogen, fluorine, or methyl; R 18 R 19 and R 20 Each independently represents a single bond. , , , , , Or alkyl groups having 1 to 3 carbon atoms; R 21 Is it freedom to choose? and The group formed; in: R 23 and R 24 Each can independently represent hydrogen, fluorine, or methyl; R 22 It is a group composed 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, -OCH2F, -OCHF2 and -OCF3; a represents an integer of 1 or 2; g, m, and i each independently represent integers from 0 to 4; Let 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 R 17 R 18 R 19 R 20 R 21 R 23 or R 24 When there are multiple, each can be the same or different.

5. The liquid crystal alignment agent as described in claim 2, wherein, Based on the total amount of silane monomer in the third mixture being 1 mole, the amount of silane monomer (b1-1) used being 0.6 moles to 1 mole, and the amount of compound (b2) used being 0.05 moles to 0.5 moles.

6. The liquid crystal alignment agent as described in claim 1, wherein, Based on the use of polymer (A) in an amount of 100 parts by weight, polysiloxane (B) in an amount of 1 to 30 parts by weight, and solvent (C) in an amount of 500 to 3000 parts by weight.

7. The liquid crystal alignment agent as described in claim 1, wherein, The imidization rate of the polymer (A) is 30% to 80%.

8. A liquid crystal alignment film formed from the liquid crystal alignment agent according to any one of claims 1 to 7.

9. A liquid crystal display element comprising the liquid crystal alignment film as described in claim 8.

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