CN106978195B

CN106978195B - Liquid crystal alignment film, liquid crystal display assembly and manufacturing method thereof

Info

Publication number: CN106978195B
Application number: CN201610976074.8A
Authority: CN
Inventors: 蔡宗沛; 黄菀婷; 邱信融
Original assignee: Chi Mei Corp
Current assignee: Chi Mei Corp
Priority date: 2015-11-17
Filing date: 2016-11-07
Publication date: 2020-12-01
Anticipated expiration: 2036-11-07
Also published as: TW201718708A; CN106978195A; TWI632177B

Abstract

The invention provides a liquid crystal alignment film, a liquid crystal display assembly and a manufacturing method thereof. The liquid crystal alignment film includes a bridge structure represented by formula (1): in the formula (1), T represents an aliphatic, alicyclic or aromatic structure; q represents an organic group containing a photoreactive group; k represents an integer of 1 or more. The liquid crystal alignment film of the invention contains a specific bridging structure, so that the problem of residual unreacted compounds in a liquid crystal layer is solved.

Description

Liquid crystal alignment film, liquid crystal display assembly and manufacturing method thereof

Technical Field

The present invention relates to a liquid crystal alignment film, a liquid crystal display device, and a method for manufacturing the same, and more particularly, to a liquid crystal alignment film capable of forming a liquid crystal display device with less residual polymerizable compound and excellent long-term reliability, a liquid crystal display device having the liquid crystal alignment film, and a method for manufacturing the liquid crystal display device.

Background

With the development of lcd devices in large-scale display specifications, the wide viewing angle technology of lcd panels must be continuously improved and broken through in order to overcome the viewing angle problem under large-scale display. A Multi-domain Vertical Alignment (MVA) lcd panel is a common wide viewing angle technology. The multi-domain vertical alignment type liquid crystal display panel is formed with protrusions in the liquid crystal panel, and the protrusions can limit the direction of the liquid crystal molecules, thereby achieving the display effect of wide viewing angle. However, the multi-domain vertical alignment type lcd panel cannot avoid the problems of insufficient transmittance and contrast due to the protrusions and slow response speed of the liquid crystal molecules.

In recent years, in order to solve the above problems, a technique of Polymer stabilized Alignment type (PSA) has been developed. This technique is to display a pretilt angle characteristic and control the liquid crystal alignment direction by interposing a liquid crystal composition containing a polymerizable compound between a pair of substrates consisting of a substrate having a patterned conductive film and a substrate not having a patterned conductive film or between a pair of substrates consisting of two substrates having patterned conductive films, and irradiating the liquid crystal composition with ultraviolet light while applying a voltage between the conductive films to polymerize the polymerizable compound. The technology can make the conductive film form a specific structure, thereby achieving the effects of expanding the visual angle and speeding up the response of liquid crystal molecules, and solving the problem that the multi-domain vertical alignment type liquid crystal display panel cannot avoid insufficient light transmittance and contrast.

However, in order to polymerize the polymerizable compound, it is necessary to irradiate, for example, 100,000J/m²Since such a large amount of ultraviolet light causes a problem of decomposition of liquid crystal molecules, there is a problem that an unreacted compound which cannot be polymerized even when ultraviolet light is irradiated remains in the liquid crystal layer. The remaining unreacted compounds are bonded to each other in the liquid crystal layer, and the long-term reliability of the panel is not good, so that the degree of practicality cannot be achieved.

Therefore, how to improve the above problems is one of the objectives of active research by those skilled in the art.

Disclosure of Invention

The invention provides a liquid crystal alignment film, a liquid crystal display device and a manufacturing method thereof, wherein the liquid crystal alignment film can form the liquid crystal display device with less polymeric compound residue and good long-term reliability.

The invention provides a liquid crystal alignment film, which comprises a bridging structure represented by a formula (1):

in the formula (1), T represents an aliphatic, alicyclic or aromatic structure; q represents an organic group containing a photoreactive group; k represents an integer of 1 or more.

In an embodiment of the invention, the photoreactive group includes at least one of a vinyl group, a (meth) acrylic group, an anthracene group (anthracenyl group), a cinnamate group (cinnamyl group), a chalcone group (chalconyl group), a coumaryl group (coumarinyl group), a maleimide group (maleimidyl group), or a distyryl group (stilbenyl group).

In an embodiment of the invention, the bridging structure is obtained by performing a radical polymerization reaction on a compound (a) having a maleamic acid group, wherein the compound (a) having a maleamic acid group has 2 or more than 2 maleamic acid groups capable of polymerizing in one molecule.

In an embodiment of the present invention, the radical polymerization reaction occurs on a double bond generated after the dehydration ring-closure reaction of the compound (a) having a maleamic acid group.

In an embodiment of the present invention, the compound (a) having a maleamic acid group is obtained by reacting a maleic anhydride derivative (a1) and a diamine component (a 2).

In an embodiment of the present invention, the diamine component (a2) comprises a diamine compound (a2-1) represented by formula (2):

in the formula (2), R_arepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃) -or-N (CH)₃)CO-。R_bRepresents a linear alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and any of the alkylene groups has a-CH group₂optionally-CF₂-, -CH ═ CH-, or the following substituents, including: -O-, -COO-, -NHCO-, -NH-, a carbocyclic group or a heterocyclic group, wherein when two or more-CH groups₂-when substituted by said substituents, said substituents are not contiguous. R_crepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃)-、-N(CH₃) CO-, carbocyclyl, or heterocyclyl. R_dRepresents vinylphenyl, -CR_e＝CH₂Carbocyclyl, heterocyclyl, or a group represented by the formula R_eRepresents a hydrogen atom or a methyl group which may be substituted by a fluorine atom:

in an embodiment of the present invention, the diamine component (a2) further includes a diamine compound (a2-2) represented by formula (3):

in the formula (3), R₃To represent

Or

R₄Represents an alkylene group having 2 to 30 carbon atoms or an organic group represented by the formula (3-1) containing a steroid group:

in the formula (3-1), R₅Represents a hydrogen atom, a fluorine atom or a methyl group; r₆、R₇Or R₈Each independently represents a single bond,

Or an alkylene group having 1 to 3 carbon atoms; r₉To represent

Wherein R is₁₁And R₁₂Each independently represents a hydrogen atom, a fluorine atom or a methyl group; r₁₀Represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 12 carbon atoms, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, -OCH₂F、-OCHF₂or-OCF₃(ii) a a represents 1 or 2; b. c and d each independently represent an integer of 0 to 4; e. f and g each independently represent an integer of 0 to 3, and e + f + g is not less than 1; h and i each independently represent 1 or 2; when there are more than one R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂In the case of (2), a plurality of R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂Each being the same or different.

In one embodiment of the present invention, the diamine compound (a2-1) is used in an amount of 5 to 70 moles based on 100 moles of the diamine component (a 2).

In one embodiment of the present invention, the diamine compound (a2-2) is used in an amount of 3 to 50 moles based on 100 moles of the diamine component (a 2).

The invention also provides a liquid crystal display assembly which comprises the liquid crystal alignment film.

The invention also provides a manufacturing method of the liquid crystal display assembly, which at least comprises the following steps: the liquid crystal alignment film is formed on a pair of substrates including conductive films. The substrate on which the liquid crystal alignment film is formed is disposed so that the liquid crystal alignment film faces the substrate. A liquid crystal composition is injected between the substrates to form a liquid crystal cell. And applying a voltage between the conductive films and irradiating the liquid crystal cell with light in a state of the applied voltage.

In view of the above, the liquid crystal alignment film of the present invention includes a specific bridge structure, and thus there is no problem of remaining unreacted compounds in the liquid crystal layer. Further, the liquid crystal alignment film of the present invention does not leave unreacted compounds in the liquid crystal layer due to the bridge structure including the organic group containing the photoreactive group, and is excellent in long-term reliability of the panel, and thus is suitable for manufacturing liquid crystal alignment films and liquid crystal display devices.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Detailed Description

In the following, acrylic acid and/or methacrylic acid is represented by (meth) acrylic acid, and acrylate and/or methacrylate is represented by (meth) acrylate; similarly, (meth) acryloyl represents acryloyl and/or methacryloyl.

Liquid crystal alignment film

The invention provides a liquid crystal alignment film, which is formed by a liquid crystal alignment agent. The liquid crystal aligning agent comprises a compound (A) with a maleic amide acid group and a solvent (C). In addition, the liquid crystal aligning agent may further include a polymer (B) and an additive (D), if necessary.

The liquid crystal alignment film of the present invention includes a bridge structure represented by formula (1):

The organic group having a photoreactive group is an organic group having a functional group that can react with light by irradiation with ultraviolet light to form a covalent bond, and the structure thereof is not limited as long as it has such an ability. The photoreactive group comprises a vinyl group, a (meth) acrylic group, an anthracene group, a cinnamic group, a chalcone group, a coumarinyl group, a maleimide group, a distyryl group, or a combination thereof. The photoreactive group may be directly bonded to the bridging structure or may be bonded through an appropriate bonding group.

Examples of the photoreactive group include, but are not limited to, groups represented by the following formulae.

-R_a-R_b-R_c-R_dFormula (1-1)

In the formula (1-1), R_arepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃) -, or-N (CH)₃)CO-。

R_bRepresents a linear alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and any of the alkylene groups has a-CH group₂optionally-CF₂-, -CH ═ CH-, or the following substituents, including: -O-, -COO-, -NHCO-, -NH-, a carbocyclic group or a heterocyclic group, wherein when two or more-CH groups₂-when substituted by said substituents, said substituents are not contiguous.

R_crepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃)-、-N(CH₃) CO-, carbocyclyl, or heterocyclyl.

R_dRepresents vinylphenyl, -CR_e＝CH₂Carbocyclyl, heterocyclyl, or a group represented by the formula R_eRepresents a hydrogen atom or a methyl group which may be substituted by a fluorine atom.

When the bridging structure in the liquid crystal alignment film does not have an organic group containing a photoreactive group, the liquid crystal layer of the liquid crystal display module prepared from the liquid crystal alignment film is still prone to have the problem of residual polymerizable compounds after being irradiated by ultraviolet rays.

The bridge structure represented by the formula (1) is obtained by radical polymerization of a compound (a) having a maleamic acid group, which has 2 or more than 2 maleamic acid groups polymerizable in one molecule, and is obtained by reaction of a maleic anhydride derivative (a1) and a diamine component (a 2).

Hereinafter, the compound (A) having a maleamic acid group will be described in detail.

Compound (A) having maleamic acid group

The compound (a) having a maleic amide acid group has 2 or more polymerizable maleic amide acid groups in one molecule, and is obtained by reacting a maleic anhydride derivative (a1) and a diamine component (a 2).

Maleic anhydride derivative (a1)

Specific examples of the maleic anhydride derivative (a1) may include, but are not limited to: maleic anhydride, 2, 3-dimethylmaleic anhydride, 2-methylmaleic anhydride, 2, 3-diethylmaleic anhydride, 2-ethylmaleic anhydride, or combinations thereof. Preferred is maleic anhydride, 2-methylmaleic anhydride or 2-ethylmaleic anhydride, and more preferred is maleic anhydride or 2-methylmaleic anhydride. The maleic anhydride derivative (a1) may be used singly or in combination of two or more.

Diamine component (a2)

The diamine component (a2) includes a diamine compound (a2-1) represented by formula (2) and a diamine compound (a2-2) represented by formula (3). In addition, the diamine component (a2) may also include other diamine compounds (a 2-3).

Diamine Compound (a2-1)

The diamine compound (a2-1) is a compound represented by formula (2).

In the formula (2), R_arepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃) -or-N (CH)₃)CO-。R_aCan be formed by a general organic synthesis method,however, from the viewpoint of ease of synthesis, -CH₂-、-O-、-NH-、-NHCO-、-CH₂O-or-COO-is preferred. R_bRepresents a linear alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and any of the alkylene groups has a-CH group₂optionally-CF₂-, -CH ═ CH-, or the following substituents, including: -O-, -COO-, -NHCO-, -NH-, a carbocyclic group or a heterocyclic group, wherein when two or more-CH groups₂-when substituted by said substituents, said substituents are not contiguous. Preferably, R_bRepresents a linear alkylene group having 1 to 20 carbon atoms, more preferably R_bRepresents a linear alkylene group having 2 to 8 carbon atoms.

The carbocyclyl group may be exemplified by the following structures, but is not limited thereto.

The heterocyclic group may be exemplified by the following structures, but is not limited thereto.

R_crepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃)-、-N(CH₃) CO-, carbocyclyl, or heterocyclyl. Preferably, R_crepresents-CH₂-, -O-, -NH-, -NHCO-, -COO-, -OCO-, carbocyclyl or heterocyclyl, preferred embodiments of the carbocyclyl and heterocyclyl and R_bThe same; more preferably, R_crepresents-CH₂-, -O-, -NH-, -NHCO-, -COO-or-OCO-.

Preferably, R_dRepresents vinylphenyl, -CH ═ CH₂、-C(CH₃)＝CH₂Or a group described below.

In the formula (2), two amino groups (-NH)₂) The bonding position(s) is not particularly limited. Specifically, the bond may be bonded to the 2, 3-position, 2, 4-position, 2, 5-position, 2, 6-position, 3, 4-position, 3, 5-position on the benzene ring relative to the bonding group of the side chain. Among them, from the viewpoint of reactivity in synthesizing a polyamic acid, a2, 4-position, a2, 5-position, or a 3, 5-position is preferable. From the viewpoint of easiness in synthesizing the diamine compound, the 2, 4-position or 3, 5-position is more preferable.

Specific examples thereof include, but are not limited to, the following compounds.

Wherein X represents-C-, -O-, -NHCO-, -CONH-, -COO-, -OCO-or-NH-, and l, m, and n each independently represents an integer of 0 to 20.

The diamine compound (a2-1) may be used singly or in combination of two or more. The diamine compound (a2-1) may be used in an amount of 5 to 70 moles, preferably 10 to 60 moles, more preferably 15 to 50 moles, based on 100 moles of the total amount of the diamine component (a2) used. When the amount of the diamine compound (a2-1) used in the liquid crystal alignment film is within this range, less unreacted polymerizable compound remains in the liquid crystal layer in the liquid crystal display device produced from the liquid crystal alignment film.

Diamine Compound (a2-2)

The diamine compound (a2-2) is a compound represented by formula (3).

In the formula (3), R₃To represent

Or

Or an alkylene group having 1 to 3 carbon atoms; r₉To represent

Wherein R is₁₁And R₁₂Each independently represents a hydrogen atom, a fluorine atom or a methyl group; r₁₀Represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 12 carbon atoms, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, -OCH₂F、-OCHF₂or-OCF₃(ii) a a represents1 or 2; b. c and d each independently represent an integer of 0 to 4; e. f and g each independently represent an integer of 0 to 3, and e + f + g is not less than 1; h and i each independently represent 1 or 2; when there are more than one R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂In the case of (2), a plurality of R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂Each being the same or different.

Specific examples of the diamine compound (a2-2) include, but are not limited to, ethyl 2, 4-diaminophenylformate (2, 4-diaminophenylethyl formate), ethyl 3, 5-diaminophenylformate (3, 5-diaminophenylethyl formate), propyl 2, 4-diaminophenylformate (2, 4-diaminophenylpropyl formate), propyl 3, 5-diaminophenylformate (3, 5-diaminophenylpropyl formate), 1-dodecyloxy-2, 4-diaminobenzene (1-dodecoxy-2, 4-diaminobenzozepine), 1-hexadecyloxy-2, 4-diaminobenzene (1-hexadecyloxy-2, 4-diaminobenzene), 1-octadecyloxy-2, 4-diaminobenzene (1-hexadecyloxy-2, 4-diaminobenzozepine), Compounds represented by formula (3-1-1) to formula (3-1-29), or combinations of the foregoing.

In the formulae (3-1-1) to (3-1-29), R₁₃Represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, R₁₄Represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. In the formulae (3-1-23) to (3-1-26), j represents an integer of 3 to 12.

Among the above diamine compounds (a2-2), 1-dodecyloxy-2, 4-diaminobenzene, 1-hexadecyloxy-2, 4-diaminobenzene, 1-octadecyloxy-2, 4-diaminobenzene, formula (3-1-3), formula (3-1-8) to formula (3-1-15), formula (3-1-19) and formula (3-1-23) are preferable.

The diamine compound (a2-2) may be used singly or in combination of two or more. The diamine compound (a2-2) may be used in an amount of 3 to 50 moles, preferably 5 to 40 moles, more preferably 10 to 30 moles, based on 100 moles of the total amount of the diamine component (a2) used. When the diamine compound (a2-2) is used as the liquid crystal alignment film, the liquid crystal display device manufactured by the liquid crystal alignment film has better long-term reliability.

Other diamine Compound (a2-3)

In addition to the diamine compound (a2-1) and the diamine compound (a2-2), other diamine compounds (a2-3) may be optionally used in combination with the diamine component (a2) of the present invention. Other diamine compounds (a2-3) may include, but are 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' -diaminoheptane, 1, 3-diamino-2, 2-dimethylpropane, 1, 6-diamino-2, 5-dimethylhexane, 1, 7-diamino-2, 5-dimethylheptane, 1, 7-diamino-4, 4-dimethylheptane, 1, 7-diamino-3-methylheptane, 1, 4-diaminobutane, 1, 7-diaminobutane, 1, 6-diaminohexane, 1, 8-diaminoheptane, 1, 9, 1, 9-diamino-5-methylnonane, 2, 11-diaminododecane, 1, 12-diaminooctadecane, 1, 2-bis (3-aminopropoxy) ethane, 4 ' -diaminodicyclohexylmethane, 4 ' -diamino-3, 3 ' -dimethyldicyclohexylamine, 1, 3-diaminocyclohexane, 1, 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadiene diamine, tricyclo [ 6.2.1.0 ]^2，7]Undecene dimethyl diamine, 4 ' -methylene bis (cyclohexylamine), 4 ' -diaminodiphenylmethane, 4 ' -diamineDiphenylethane, 4 ' -diaminodiphenyl sulfone, 4 ' -diaminobenzanilide, 4 ' -diaminodiphenyl ether, 3, 4 ' -diaminodiphenyl ether, 1, 5-diaminonaphthalene, 5-amino-1- (4 ' -aminophenyl) -1, 3, 3-trimethylindane, 6-amino-1- (4 ' -aminophenyl) -1, 3, 3-trimethylindane, hexahydro-4, 7-methanoindenyldimethylenediamine, 3, 3 ' -diaminobenzophenone, 3, 4 ' -diaminobenzophenone, 4 ' -diaminobenzophenone, 2-bis [4- (4-aminophenoxy) phenylformanilide]Propane, 2-bis [4- (4-aminophenoxy) phenyl]Hexafluoropropane, 2-bis (4-aminophenyl) hexafluoropropane, 2-bis [4- (4-aminophenoxy) phenyl]Sulfone, 1, 4-bis (4-aminophenoxy) benzene, 1, 3-bis (3-aminophenoxy) benzene, 9-bis (4-aminophenyl) -10-hydroanthracene, 9, 10-bis (4-aminophenyl) anthracene (9, 10-bis (4-aminophenyl) anthracene), 2, 7-diaminofluorene, 9-bis (4-aminophenyl) fluorene, 4 '-methylene-bis (2-chloroaniline), 4' - (p-phenyleneisopropyl) dianiline, 4 '- (m-phenyleneisopropyl) dianiline, 2' -bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl.]Hexafluoropropane, 4' -bis [ (4-amino-2-trifluoromethyl) phenoxy ] benzene]-octafluorobiphenyl, 5- [4- (4-n-pentylcyclohexyl) cyclohexyl]Phenyl-methylene-1, 3-diaminobenzene (5- [4- (4-n-phenylcyclohexyloxy) cyclohexyloxy)]phenylmethyl-1, 3-diaminobezene) or 1, 1-bis [4- (4-aminophenoxy) phenyl]-4- (4-ethylphenyl) cyclohexane (1, 1-bis [4- (4-aminophenyl) phenyl [)]-4- (4-ethylphenyl) cyclohexane, a compound represented by formula (4-1) to formula (4-23), or a combination of the above compounds.

In the formula (4-1), R₃As described above, and R₁₅Represents a trifluoromethyl group, a fluoro group, or a monovalent group derived from a nitrogen atom-containing cyclic structure such as pyridine, pyrimidine, triazine, piperidine, or piperazine.

In the formula (4-2), R₃As described above, and R₁₆And R₁₇Represents an alicyclic, aromatic or heterocyclic ring group, and R₁₈Represents an alkyl group having 3 to 18 carbon atoms, an alkoxy group having 3 to 18 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, a fluoroalkoxy group having 1 to 5 carbon atoms, a cyano group or a halogen atom.

The other diamine compound (a2-3) represented by the formula (4-2) is preferably selected from compounds represented by the following formulae (4-2-1) to (4-2-5):

in the formula (4-3), R₁₉Represents 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 R in each repeating unit₁₉May be the same or different, and p₁Is an integer of 1 to 3. The other diamine compound (a2-3) represented by the formula (4-3) is preferably selected from (1) when p₁When the ratio is 1: p-diaminobenzene, m-diaminobenzene, o-diaminobenzene, 2, 5-diaminotoluene, or the like; (2) when p is₁When the ratio is 2: 4, 4 ' -diaminobiphenyl, 2 ' -dimethyl-4, 4 ' -diaminobiphenyl, 3 ' -dimethoxy-4, 4 ' -diaminobiphenyl, 2 ' -dichloro-4, 4 ' -diaminobiphenyl, 3 ' -dichloro-4, 4 ' -diaminobiphenyl, 2 ', 5, 5 ' -tetrachloro-4, 4 ' -diaminobiphenyl, 2 ' -dichloro-4, 4 ' -diamino-5, 5 ' -dimethoxybiphenyl, 4 ' -diamino-2, 2 ' -bis (trifluoromethyl) biphenyl, or the like; (3) when p is₁When the ratio is 3: 1, 4-bis (4' -aminophenyl) benzene, and the like. Among them, p-diaminobenzene, 2, 5-diaminotoluene, 4 ' -diaminobiphenyl, 3 ' -dimethoxy-4, 4 ' -diaminobiphenyl are more preferableAnd 1, 4-bis (4' -aminophenyl) benzene.

In the formula (4-4), p₂Is an integer from 2 to 12.

In the formula (4-5), p₃Is an integer of 1 to 5. The formula (4-5) is preferably 4, 4' -diamino-diphenyl sulfide.

In the formula (4-6), R₂₀And R₂₂Are the same or different and each represents a divalent organic group; r₂₁Represents a divalent group derived from a nitrogen atom-containing cyclic structure such as pyridine, pyrimidine, triazine, piperidine or piperazine.

In the formula (4-7), R₂₃、R₂₄、R₂₅And R₂₆Are the same or different and each represents a hydrocarbon group having 1 to 12 carbon atoms; p is a radical of₄Represents an integer of 1 to 3; p is a radical of₅Represents an integer of 1 to 20.

In the formula (4-8), R₂₇Represents an oxygen atom or a cyclohexylene group; r₂₈represents-CH₂-；R₂₉Represents phenylene or cyclohexylene; r₃₀Represents a hydrogen atom or a heptyl group. The other diamine compound (a2-3) represented by the formula (4-8) is preferably selected from those represented by the following formulae (4-8-1) and (4-8-2)The compound of (1):

other diamine compounds (a2-3) represented by the formulae (4-9) to (4-15) are shown below:

in formulae (4-9) to (4-15), R₃₁Preferably an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, R₃₂Preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

Other diamine compounds (a2-3) represented by the formulae (4-16) to (4-23) are shown below:

among the other diamine compounds (a2-3) mentioned above, 1, 2-diaminoethane, 4 ' -diaminodicyclohexylmethane, 4 ' -diaminodiphenylmethane, 4 ' -diaminodiphenyl ether, 5- [4- (4-n-pentylcyclohexyl) cyclohexyl ] phenylmethylene-1, 3-diaminobenzene, 1-bis [4- (4-aminophenoxy) phenyl ] -4- (4-ethylphenyl) cyclohexane, p-diaminobenzene, m-diaminobenzene, o-diaminobenzene, a compound represented by the formula (4-8-1), or a combination of the above-mentioned compounds is preferable.

The other diamine compounds (a2-3) may be used singly or in combination of two or more. The other diamine compound (a2-3) may be used in an amount of 0 to 70 moles, preferably 5 to 60 moles, more preferably 10 to 50 moles, based on 100 moles of the total amount of the diamine component (a2) used.

The method for producing the compound (a) having a maleamic acid group of the present invention is not limited, and the compound (a) is generally obtained by reacting a maleic anhydride derivative (a1) and a diamine component (a2) in an organic solvent. The organic solvent is not particularly limited in kind as long as it can dissolve the reactant. Specific examples of the organic solvent include: n-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, N-methylcaprolactam, γ -butyrolactone, acetone, methyl ethyl ketone, ethylene glycol N-butyl ether, dioxane, tetrahydrofuran, or a combination of the above compounds. The solvent may be used singly or in combination of two or more. The reaction temperature of the maleic anhydride derivative (a1) and the diamine component (a2) is generally 0 to 100 ℃, preferably 0 to 80 ℃, and more preferably 0 to 70 ℃. The reaction time is generally 1 to 5 hours, preferably 2 to 4 hours.

The maleic anhydride derivative (a1) and the diamine component (a2) are used in a ratio of generally 0.5 to 2.5, preferably 0.8 to 2.0, more preferably 1.0 to 1.8, based on the molar ratio of the acid anhydride group of the maleic anhydride derivative (a1) to the amino group of the diamine component (a 2).

The compound (A) having a maleamic acid group of the present invention has a weight average molecular weight of 2,500 to 150,000, preferably 3,500 to 100,000, more preferably 4,500 to 80,000 as measured by Gel Permeation Chromatography (GPC) in terms of polystyrene.

Polymer (B)

The polymer (B) of the present invention is at least one polymer selected from the group consisting of polyesters, polyesterimides, polyamideimide acids, polyamideimides, polyamic acid esters, polyamides, and polyimide-based polymers obtained by a polycondensation reaction. Wherein the polyimide polymer comprises polyamic acid (B-1) and/or polyimide (B-2) and/or a polyimide block copolymer (B-3).

The polyimide block copolymer (B-3) comprises a polyamic acid block copolymer (B-3-1) and/or a polyimide block copolymer (B-3-2) and/or a polyamic acid-polyimide block copolymer (B-3-3).

The polyimide block copolymer (B-3) is, for example, a polyamide acid block copolymer (B-3-1) of a1 st polyamide acid block represented by the formula (5-1) and a2 nd polyamide acid block having a different structure;

in the formula, J¹、J²Represent identical or different 4-valent organic radicals; k¹、K²Represent identical or different 2-valent organic groups; j. the design is a square¹、J²When are the same, K¹、K²Are different or vice versa, or J¹、J²And K¹、K²Simultaneously, the two are different; x is the number of¹And y¹Each independently represents an integer of 1 to 2,000, and z represents an integer of 1 to 100.

A polyimide block copolymer (B-3-2) comprising a1 st polyimide block represented by the formula (5-2) and a2 nd polyimide block having a different structure;

in the formula, J³、J⁴Represent identical or different 4-valent organic radicals; k³、K⁴Represent identical or different 2-valent organic groups; j. the design is a square³、J⁴When are the same, K³、K⁴Are different or vice versa, or J³、J⁴And K³、K⁴Simultaneously, the two are different; x is the number of¹And y¹Each independently represents an integer of 1 to 2,000, and z represents an integer of 1 to 100.

And a polyamic acid-polyimide block copolymer (B-3-3) comprising a polyamic acid block represented by the formula (5-3) and a polyimide block.

In the formula, J⁵、J⁶Represent identical or different 4-valent organic radicals; k⁵、K⁶Represent identical or different 2-valent organic groups; j. the design is a square⁵、J⁶When are the same, K⁵、K⁶Are different or vice versa, or J⁵、J⁶And K⁵、K⁶Simultaneously, the two are different; x is the number of¹And y¹Each independently represents an integer of 1 to 2,000, and z represents an integer of 1 to 100.

The polymer (B) of the present invention is preferably a polyimide-based polymer. The tetracarboxylic dianhydride compound and the diamine compound used for the polyimide-based polymer are not particularly limited. Specific examples of the tetracarboxylic dianhydride compound include, but are not limited to, ethaneditetracarboxylic dianhydride, butanetetracarboxylic dianhydride, 1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 2-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, 1, 2,5, 6-cyclohexanetetracarboxylic dianhydride, 3 ', 4, 4' -dicyclohexyltetracarboxylic dianhydride, 1, 2,5, 6-cyclohexanetetracarboxylic dianhydride, Bicycloheptane tetracarboxylic dianhydride, 3 ' -dicyclohexyl-1, 1 ', 2, 2 ' -tetracarboxylic dianhydride, 2,3, 5-tricarboxycyclopentyl acetic dianhydride, 3,5, 6-tricarboxynorbornane-2-acetic dianhydride (3, 5, 6-tricarboxynorbornane-2-acetic dianhydride, 2,3, 4, 5-tetrahydrofuran tetracarboxylic dianhydride, tetracyclo [6.2.1 ]^1，3.0^2，7]Dodecane-4, 5, 9, 10-tetracarboxylic dianhydride, 3, 4-dicarboxy-1, 2,3, 4-tetrahydronaphthalene-1-succinic dianhydride, 1, 3, 3a, 4,5, 9b-hexahydro-5 (tetrahydro-2, 5-bisacetoxy-3-furanyl) -naphtho [1, 2-c ] dianhydride]-furan-1, 3-dione (1, 3, 3a, 4,5, 9b-hexahydro-5- (tetrahydro-2, 5-dioxo-3-furanyl) -naphto [1, 2-c)]-furan-1, 3-dione), 1, 3, 3a, 4,5, 9 b-hexahydro-5-methyl-5 (tetrahydro-2, 5-bisoxy-3-furyl) -naphtho [1, 2-c]-furan-one1, 3-dione, 1, 3, 3a, 4,5, 9 b-hexahydro-5-ethyl-5 (tetrahydro-2, 5-bisacetoxy-3-furanyl) -naphtho [1, 2-c]-furan-1, 3-dione, 1, 3, 3a, 4,5, 9 b-hexahydro-7-methyl-5 (tetrahydro-2, 5-bisoxylo-3-furanyl) -naphtho [1, 2-c]-furan-1, 3-dione, 1, 3, 3a, 4,5, 9 b-hexahydro-7-ethyl-5 (tetrahydro-2, 5-bisoxylo-3-furanyl) -naphtho [1, 2-c]-furan-1, 3-dione, 1, 3, 3a, 4,5, 9 b-hexahydro-8-methyl-5 (tetrahydro-2, 5-bisoxylo-3-furanyl) -naphtho [1, 2-c]-furan-1, 3-dione, 1, 3, 3a, 4,5, 9 b-hexahydro-8-ethyl-5 (tetrahydro-2, 5-bisoxylo-3-furanyl) -naphtho [1, 2-c]-furan-1, 3-dione, 1, 3, 3a, 4,5, 9b-hexahydro-5, 8-dimethyl-5 (tetrahydro-2, 5-bisoxyl-3-furyl) -naphtho [1, 2-c]-furan-1, 3-dione, 5- (2, 5-bisethoxytetrahydrofuryl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic acid dianhydride, bicyclo [2.2.2]-oct-7-ene-2, 3,5, 6-tetracarboxylic dianhydride, bicyclo [3.3.0]Octane-2, 4, 6, 8-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1]Octane-2, 4-dione-6-spiro-3 ' - (tetrahydrofuran-2 ', 5 ' -dione) (3-oxabicyc1o [ 3.2.1)]-octane-2, 4-dione-6-spiro-3 '- (tetrahydrofuran-2', 5 '-dione)), benzopyromellitic dianhydride, 2,3, 3', 4 '-benzophenonetetracarboxylic dianhydride, 3, 3', 4, 4 '-benzophenonetetracarboxylic dianhydride, 2', 3, 3 '-biphenyltetracarboxylic dianhydride, 2,3, 3', 4-biphenyltetracarboxylic dianhydride, 3, 3 ', 4, 4' -biphenylsulfonetetracarboxylic dianhydride, 1, 2,5, 6-naphthalenetetracarboxylic dianhydride, 1, 4,5, 8-naphthalenetetracarboxylic dianhydride, 2,3, 6, 7-anthracenetetracarboxylic dianhydride, 1, 2,5, 6-anthracenetetracarboxylic dianhydride, Bis (3, 4-dicarboxyphenyl) ether dianhydride, bis (3, 4-dicarboxyphenyl) sulfone dianhydride, bis (3, 4-dicarboxyphenyl) methane dianhydride, 2-bis (3, 4-dicarboxyphenyl) propane dianhydride, 1, 1, 1, 3, 3, 3-hexafluoro-2, 2-bis (3, 4-dicarboxyphenyl) propane dianhydride, bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3, 4-dicarboxyphenyl) diphenylsilane dianhydride, 2,3, 4, 5-pyridinetetracarboxylic dianhydride, 2, 6-bis (3, 4-dicarboxyphenyl) pyridine dianhydride, 3, 3 ', 4, 4' -dimethyldiphenylsilane dianhydrideTetracarboxylic dianhydride, 3 ', 4, 4' -tetraphenylsilane tetracarboxylic dianhydride, 1, 2,3, 4-furantetracarboxylic dianhydride, 4, 4 '-bis (3, 4-dicarboxybenzyl) diphenylmethane dianhydride, 4, 4' -bis (3, 4-dicarboxybenzyl) diphenylethane dianhydride, 4, 4 '-bis (3, 4-dicarboxybenzyl) diphenylpropane dianhydride, 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenylmethane dianhydride, 4, 4 '-bis (3, 4-dicarboxyphenoxy) diphenylethane dianhydride, 4, 4' -bis (3, 4-dicarboxyphenoxy) diphenylpropane dianhydride, 4, 4 '-bis (3, 4-dicarboxyphenoxy) diphenylsulfide dianhydride, 1, 2,3, 4, 4-furantetracarboxylic dianhydride, 4' -bis (3, 4-dicarboxyphenyl) diphenylmethane dianhydride, 4, 4, 4 ' -bis (3, 4-dicarboxyphenoxy) diphenylsulfone dianhydride, 3 ', 4, 4 ' -perfluoropropylidenediphthalic acid dianhydride, 3 ', 4, 4 ' -perfluoroisopropylidenediphthalic acid dianhydride, bis (phthalic) phenylphosphine oxide dianhydride (bis (phthalic acid) phenylphosphine oxide dianhydride), bis (phthalic) phenylthiodianhydride (bis (phthalic acid) phenylsulfenxide dianhydride), p-phenylene-bis (triphenylphthalic acid) dianhydride (p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4, 4 ' -diphenyl ether dianhydride, bis (triphenylphthalic acid) -4, 4 ' -diphenylmethane dianhydride, ethylene glycol-bis (anhydrous trimellitate) (maleic anhydride) dianhydride, Propylene glycol-bis (anhydrous trimellitic anhydride ester), 1, 4-butanediol-bis (anhydrous trimellitic anhydride ester), 1, 6-hexanediol-bis (anhydrous trimellitic anhydride ester), 1, 8-octanediol-bis (anhydrous trimellitic anhydride ester), 2-bis (4-hydroxyphenyl) propane-bis (anhydrous trimellitic anhydride ester), tetracarboxylic dianhydride compounds represented by formulae (6-1) to (6-6), or a combination of the above compounds. The above-mentioned compounds may be used singly or in combination of plural kinds.

In the formula, R₄₁And R₄₃Each independently represents a 2-valent organic group containing an aromatic ring, R₄₂And R₄₄Each independently represents a hydrogen atom or an alkyl group, R being present in plural₄₂And R₄₄May be the same or different, respectively.

These compounds may be used singly or in admixture of plural.

Among the above tetracarboxylic dianhydride compounds, 1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 2,3, 4-cyclopentanetetracarboxylic dianhydride, 2,3, 5-tricarboxycyclopentylacetic dianhydride, 3, 4-dicarboxy-1, 2,3, 4-tetrahydronaphthalene-1-succinic dianhydride, pyromellitic dianhydride, 3 ', 4, 4' -diphenylsulfone tetracarboxylic dianhydride are preferred.

Specific examples of the diamine compound used in the polymer (B) of the present invention are the same as those exemplified for the compound (A) having a maleamic acid group, and are not described again.

In the polymer (B) of the invention, the polyamic acid (B-1) is obtained by polycondensing a tetracarboxylic dianhydride compound and a diamine compound. Wherein the acid anhydride group of the tetracarboxylic dianhydride compound is 0.2 to 2 equivalents, preferably 0.8 to 1.2 equivalents, based on 1 equivalent of the amino group of the diamine compound.

In the polycondensation reaction of the polyamic acid (B-1), the reaction temperature of the tetracarboxylic dianhydride compound and the diamine compound in the organic solvent is generally-20 to 150 ℃, preferably 0 to 100 ℃. The organic solvent is not particularly limited as long as it can dissolve the reaction product and the product. Specific examples of the organic solvent include, but are not limited to: aprotic polar solvents such as N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, tetramethylurea, and hexamethylphosphoric triamide; phenol solvents such as m-cresol, xylenol, phenol, and halogenated phenols. The organic solvent may be used singly or in combination of two or more.

In the above organic solvent, an appropriate amount of a poor solvent such as: alcohols, ketones, esters, ethers, halogenated hydrocarbons, and the like. Specific examples of lean solvents include, but are not limited to: methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1, 4-butanediol, triethylene glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, 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, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane, 1, 2-dichloroethane, 1, 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, and the like. The lean solvent may be used singly or in combination.

The polyamic acid (B-1) can be obtained by pouring the reaction solution of the polyamic acid (B-1) obtained above into a large amount of a poor solvent to obtain a precipitate, drying the precipitate under reduced pressure or distilling the reaction solution under reduced pressure with an evaporator. Further, the polyamic acid (B-1) is dissolved again in the organic solvent and then precipitated with a poor solvent, or distilled under reduced pressure with an evaporator, and the above-mentioned processes are repeated one or more times to obtain a purified polyamic acid (B-1).

In the polymer (B) of the present invention, the polyimide (B-2) is obtained by subjecting the polyamic acid (B-1) to dehydration ring-closure (imidization).

The imidization treatment of the polyamic acid (B-1) may be, for example: polyamic acid (B-1) is dissolved in an organic solvent and heated in the presence of a dehydrating agent and an imidization catalyst to effect a dehydration ring-closure reaction. The temperature for the imidization is generally 40 to 200 ℃, preferably 80 to 150 ℃. Specific examples of the dehydrating agent to be used include, but are not limited to, acid anhydride-based compounds such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride, and the amount of the dehydrating agent to be used is preferably from 0.01 to 20 moles based on 1 mole of polyamic acid (B-1). Specific examples of the imidization catalyst include, but are not limited to, tertiary amines such as pyridine, collidine, lutidine, triethylamine, etc., and the amount of the imidization catalyst to be used is 1 mole, preferably 0.5 to 10 moles, based on the dehydrating agent. Specific examples of the solvent used for the imidization treatment include those listed in the polycondensation reaction of the polyamic acid (B-1), and will not be described herein again.

The resultant polyimide (B-2) reaction solution may be further processed in the same manner as in the purification method of the polyamic acid (B-1) to obtain a purified polyimide (B-2).

In the polymer (B) of the present invention, the polyimide-based block copolymer (B-3) includes, depending on the kind of the monomer: polyamic acid block copolymer (B-3-1), polyimide block copolymer (B-3-2), and polyamic acid-polyimide block copolymer (B-3-3). The polyimide-based block copolymer (B-3) is obtained by further subjecting a compound selected from the group consisting of a polyamic acid (B-1), a polyimide (B-2), a tetracarboxylic dianhydride compound and a diamine compound to a polycondensation reaction in an organic solvent. Examples of the choice of compounds are: 2 polyamic acids (B-1) having different terminal groups and different structures; 2 types of polyimides (B-2) having different terminal groups and different structures; polyamic acid (B-1) and polyimide (B-2) having different terminal groups and different structures; polyamic acid (B-1), tetracarboxylic dianhydride compound and diamine compound, wherein at least one of tetracarboxylic dianhydride compound and diamine compound has different structures with the tetracarboxylic dianhydride compound and diamine compound used in the condensation reaction of polyamic acid (B-1); a polyimide (B-2), a tetracarboxylic dianhydride compound and a diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and the diamine compound has a different structure from the tetracarboxylic dianhydride compound and the diamine compound used in the condensation reaction of the polyimide (B-2); polyamic acid (B-1) and polyimide (B-2), and a tetracarboxylic dianhydride compound and a diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and the diamine compound has a different structure from the tetracarboxylic dianhydride compound and the diamine compound used in the condensation reaction of polyamic acid (B-1) and polyimide (B-2); 2 kinds of polyamide acid (B-1) and tetracarboxylic dianhydride compound and diamine compound with different structures; 2 kinds of polyimide (B-2) with different structures, a tetracarboxylic dianhydride compound and a diamine compound; 2 kinds of polyamide acid (B-1) and diamine compound with end group as acid anhydride group and different structure; 2 kinds of polyamic acid (B-1) and tetracarboxylic dianhydride compounds with different structures and end groups of amino groups; 2 kinds of polyimide (B-2) and diamine compounds having different structures in which the terminal group is an acid anhydride group; 2 kinds of polyimide (B-2) having an amino group as a terminal group and having a different structure, a tetracarboxylic dianhydride compound, and the like.

In the polycondensation of the polyimide-based block copolymer (B-3), the reaction temperature is generally from 0 to 200 ℃, preferably from 0 to 100 ℃. Specific examples of the solvent to be used include those exemplified in the polycondensation reaction of the polyamic acid (B-1), and will not be described herein.

The resulting reaction solution of the polyimide-based block copolymer (B-3) can be further processed in the same manner as the purification method of the polyamic acid (B-1) to obtain a purified polyimide-based block copolymer (B-3).

The polymer (B) of the present invention has a weight average molecular weight of 2,000 to 200,000, preferably 3,000 to 100,000, more preferably 4,000 to 50,000 in terms of polystyrene as measured by gel permeation chromatography.

The polymer (B) may be used in an amount of 3 to 100 parts by weight, preferably 10 to 80 parts by weight, more preferably 15 to 60 parts by weight, based on 100 parts by weight of the compound (A) having a maleamic acid group. When the liquid crystal alignment film contains the polymer (B), the liquid crystal display component prepared by the liquid crystal alignment film has better long-term reliability.

Solvent (C)

The solvent (C) of the liquid crystal aligning agent of the present invention can be selected from the solvents used in the above-mentioned process for preparing the compound (A) having a maleamic acid group and the polymer (B), and will not be described herein again. The amount of the solvent (C) is 500 to 5,000 parts by weight, preferably 800 to 4,000 parts by weight, more preferably 1,000 to 3,000 parts by weight, based on 100 parts by weight of the compound (A) having a maleamic acid group.

Additive (D)

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound or an epoxy compound in a range not to impair the desired physical properties. Specific examples of the functional silane-containing compound include, but are not limited to: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane (3-uredopropyltrimethoxysilane), 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1, 4, 7-triazodecane, 10-triethoxysilyl-1, 4, 7-triazodecane, 9-trimethoxysilyl-3, 6-diazacyclononyl acetate, 9-triethoxysilyl-3, 6-diazacyclononyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, n-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, or combinations of the foregoing.

Specific examples of epoxy compounds 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-dibromoneopentyl glycol diglycidyl ether, 1, 3,5, 6-tetracyclooxypropyl-2, 4-hexanediol, N, N, N ', N ' -tetracyclooxypropyl-m-xylylenediamine, 1, 3-bis (N, N-diepoxylaminomethyl) cyclohexane, N, N, N ', N ' -tetracyclooxypropyl-4, 4 ' -diaminodiphenylmethane, 3- (N-allyl-N-epoxypropyl) aminopropyltrimethoxysilane, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1, 6-dibromoneopentyl glycol diglycidyl ether, 1, 3,5, 6-tetracyclooxypropyl-2, 4-hexanediol, N, N ', N ' -tetracyclooxypropyl-m-xylylenediamine, 1, 3- (N, N-diepoxypropyl) aminopropyltrimethoxysilane, or combinations of the foregoing.

The additive (D) may be used in an amount of 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight, based on 100 parts by weight of the compound (a) having a maleamic acid group.

Method for preparing liquid crystal aligning agent

The liquid crystal aligning agent of the present invention includes a compound (a) having a maleamic acid group and a solvent (C), and a polymer (B) or an additive (D) may be further added. The liquid crystal aligning agent is prepared by dissolving a compound (A) having a maleic acid amide group, a polymer (B) and an additive (D) in a solvent (C) and mixing them uniformly, wherein the temperature for preparing the aligning agent is generally 0 to 200 ℃, preferably 0 to 100 ℃.

Formation of liquid crystal alignment film

The liquid crystal alignment agent is coated on a substrate, and then dehydration ring closure and free radical polymerization are carried out to obtain the liquid crystal alignment film.

First, the liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a transparent conductive film by a method such as a roll coating method, a spin coating method, a printing method, or an ink-jet method (ink-jet). Among them, a printing method is preferable. Then, the coated surface is subjected to a heat treatment to form a coating film on the liquid crystal aligning agent.

Specific examples of the substrate include, but are not limited to: glasses such as alkali-free glass, soda lime glass, hard glass (pyrex glass), and quartz glass; a plastic transparent substrate of polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, or the like.

The heat treatment for forming the liquid crystal alignment film includes a pre-bake treatment (pre-bake) after coating the liquid crystal alignment agent, the pre-bake treatment can volatilize the organic solvent to form a coating film, and the heat treatment temperature is generally 30 to 150 ℃, preferably 50 to 120 ℃, and more preferably 60 to 100 ℃. The pre-baking treatment may be performed for any time from 0.1 minute to 30 minutes, preferably from 0.5 minute to 15 minutes, and more preferably from 1 minute to 5 minutes.

After the coating film is formed, post-bake treatment (post-bake) is further performed to simultaneously perform dehydration ring closure (imidization) and radical polymerization reaction, thereby forming an imidized alignment film coating film. The post-baking treatment temperature is generally 100 to 350 ℃, preferably 120 to 280 ℃, more preferably 150 to 250 ℃. The post-baking treatment may be performed for any time from 5 minutes to 240 minutes, preferably from 10 minutes to 100 minutes, and more preferably from 20 minutes to 90 minutes. The heating may be performed by a generally known method, for example, a hot plate, a hot air circulating furnace or an infrared furnace.

In the process of forming the liquid crystal alignment film of the present invention, the ultraviolet irradiation may be performed first, and then the post-heating process may be performed. The liquid crystal aligning agent may also contain a photo-polymerization initiator or a thermal-polymerization initiator as required.

Wherein, the dehydration ring-closure (imidization) reaction is to form a maleimide group by imidizing a maleamic acid group, and the specific example of the reaction is shown in the reaction formula (1):

the radical polymerization is a polymerization reaction of a compound containing a double bond of C ═ C, such as a compound containing maleimide groups, to form a bridged structure. And the radical polymerization reaction occurs at a double bond generated after dehydration ring-closure reaction of the compound (A) having a maleamic acid group. Specific examples of the reaction are shown in the following reaction formula (2):

specific examples of the imidized alignment film obtained by the cyclodehydration (imidization) and radical polymerization are alignment films having a bridge structure represented by the following formula.

Method for manufacturing liquid crystal display module

The liquid crystal display device of the present invention can be manufactured according to the following method.

First, the liquid crystal alignment films as described above are formed on a pair of substrates including conductive films, respectively, the substrates on which the liquid crystal alignment films are formed are arranged in such a manner that the liquid crystal alignment films face each other, and a liquid crystal composition is injected between the substrates to form liquid crystal cells, and then a voltage is applied between the conductive films, and the liquid crystal cells are irradiated with light in a state where the voltage is applied. Finally, a polarizing plate is attached to the outer surface of the liquid crystal cell, thereby obtaining the liquid crystal display module of the present invention. The substrate used is the same as the substrate used in the formation of the liquid crystal alignment film, and is not described herein again.

As the conductive film, a transparent conductive film such as SnO₂Formed NESA film of In₂O₃-SnO₂An ITO film formed, and the like. The conductive film is preferably a patterned conductive film divided into a plurality of regions. When the conductive film structure is formed and voltage is applied between the conductive films, the pretilt angle direction of the liquid crystal molecules in each area can be changed by applying different voltage to each area, so that the visual angle property can be further improved.

The following 2 methods can be exemplified for producing liquid crystal cells.

The first method is currently available. First, 2 substrates were arranged to face each other with a gap (cell gap) therebetween, and the respective liquid crystal alignment films were opposed to each other, and peripheral portions of the 2 substrates were bonded together with a sealant, and a liquid crystal was injected into the cell gap defined by the substrate surface and the sealant, and then the injection hole was sealed, thereby manufacturing a liquid crystal cell.

The second method is a method called odf (one Drop fill) method. For example, an ultraviolet-curable sealing material is applied to a predetermined position on one of 2 substrates on which a liquid crystal alignment film is formed, liquid crystal is dropped on the liquid crystal alignment film surface, the other substrate is attached to face the liquid crystal alignment film, and then ultraviolet light is irradiated to the entire surface of the substrate to cure the sealing material, thereby producing a liquid crystal cell.

Among them, as the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers (spacers) is exemplified.

As the liquid crystal composition, a polymerizable compound may be added to a nematic liquid crystal having negative dielectric anisotropy, for example, a liquid crystal such as a dicyanobenzene-based liquid crystal, a pyridazine-based liquid crystal, a schiff-base-based liquid crystal, an azoxy-based liquid crystal, a biphenyl-based liquid crystal, or a phenylcyclohexane-based liquid crystal, and a generally known compound may be used as the polymerizable compound, and the type of the polymerizable compound is not particularly limited, and examples thereof include a compound having an acryloyl group and a liquid crystal skeleton. In addition, a polymerizable compound and a polymerization initiator may be added to the liquid crystal in combination. The amount of the polymerizable compound added is generally 0.1 to 1% by weight.

The applied voltage may be, for example, a direct current or an alternating current of 5V to 50V.

As the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800nm, preferably ultraviolet rays including light having a wavelength of 300 to 400nm, can be used. Examples of the light source for the irradiation light include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The ultraviolet light in the preferred wavelength range can be obtained by a method of using the light source in combination with, for example, a color filter, a diffraction grating, or the like.

The dose of light irradiation is preferably 1,000J/m²Above and less than 100,000J/m²More preferably 1,000 to 50,000J/m². When a liquid crystal display module of a PSA mode known in the past is manufactured, 100,000J/m is required²The amount of light irradiation. However, in the method of the present invention, even if the light irradiation amount is 50,000J/m²Hereinafter, it is further 10,000J/m²In the following, a good liquid crystal display device can be obtained, which contributes to reduction of the manufacturing cost of the liquid crystal display device.

Examples of the polarizing plate to be attached to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a polarizing film called "H film" obtained by stretching and aligning polyvinyl alcohol while absorbing iodine with a protective film of cellulose acetate, and a polarizing plate formed by the H film itself.

The invention will be further described in the following examples, but it should be understood that these examples are illustrative only and should not be construed as limiting the practice of the invention.

Synthesis example of Compound (A) having maleic acid amide group

Synthesis examples A-1 to A-12 of the Compound (A) having a maleamic acid group are described below:

synthesis example A-1

A four-necked flask having a capacity of 500 ml was equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer, and nitrogen gas was introduced thereinto. Then, in a four-necked flask, 3.95 g (0.015 mol) of a diamine compound Da1 (abbreviated as a2-1-1), 2.82 g (0.0075 mol) of 1-octadecyloxy-2, 4-diaminobenzene (abbreviated as a2-2-1) and 50 g of tetrahydrofuran (hereinafter abbreviated as THF) were charged and stirred at room temperature until dissolved. Then, 2.81 g (0.025 mol) of 2-methylmaleic anhydride (referred to as a1-1 for short) was added thereto and reacted at room temperature for 3 hours, after the reaction was completed, the reaction solution was filtered, and the solid obtained by the filtration was repeatedly washed with THF and filtered three times, and then placed in a vacuum oven and dried at 60 ℃ to obtain compound (A-1) having a maleamic acid group.

Synthesis examples A-2 to A-12 and comparative Synthesis examples A-13 to A-15

Synthesis examples A-2 to A-12 and comparative Synthesis examples A-13 to A-15 Compounds (A-2) to (A-15) having a maleamidic acid group were prepared in the same procedure as in Synthesis example A-1, respectively, and they were different in that: the kind of the monomer and the amount thereof used were changed (as shown in Table 1).

The compounds corresponding to the abbreviations in table 1 are shown below.

Component for short

a 1-12-methylmaleic anhydride

a1-2 maleic anhydride

a 1-32-ethylmaleic anhydride

a 1-42, 3-dimethylmaleic anhydride

a2-1-1

a2-1-2

a2-1-3

a2-1-4

a 2-2-11-octadecyloxy-2, 4-diaminobenzene

a2-2-2

a2-2-3

R₁₄: pentyl radical

a2-2-4

R₁₄: propyl radical

a 2-3-1-p-diaminobenzene

a 2-3-24, 4' -diaminodiphenylmethane

a 2-3-34, 4' -diaminodiphenyl ether

a 2-3-41, 3-diaminocyclohexane

Synthesis example of Polymer (B)

Synthesis examples B-1 to B-3 of the polymer (B) are described below:

synthesis example B-1

A four-necked flask having a capacity of 500 ml was equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer, and nitrogen gas was introduced thereinto. Then, in a four-necked flask, 20.0 g (0.1 mol) of 4, 4' -diaminodiphenyl ether and 180 g of N-methylpyrrolidone (hereinafter abbreviated as NMP) were charged and stirred at room temperature until dissolved. Then 10.9 g (0.05 mol) of pyromellitic dianhydride, 9.8 g (0.05 mol) of cyclobutanetetracarboxylic dianhydride and 50 g of NMP were added to react at room temperature for 6 hours, after the reaction was completed, the reaction solution was poured into 1500 ml of water to precipitate the polymer, and the polymer obtained by filtration was washed with methanol and filtered three times, and then placed in a vacuum oven to be dried at 60 ℃ to obtain the polymer (B-1).

Synthesis example B-2

A four-necked flask having a capacity of 500 ml was equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer, and nitrogen gas was introduced thereinto. Then, in a four-necked flask, 10.8 g (0.1 mol) of p-diaminobenzene and 100 g of NMP were added and stirred at room temperature until dissolved. Then, 33.0 g (0.11 mol) of 3, 4-dicarboxy-1, 2,3, 4-tetrahydronaphthalene-1-succinic dianhydride and 60 g of NMP were added and reacted at room temperature for 6 hours, and after the reaction was completed, 97 g of NMP, 2.55 g of acetic anhydride and 19.75 g of pyridine were added and heated to 60 ℃ and stirred for 2 hours to effect imidization. After the reaction, the reaction solution was poured into 1500 ml of water to precipitate a polymer, and the polymer obtained by filtration was repeatedly washed with methanol and filtered three times, and then placed in a vacuum oven to be dried at 60 ℃ to obtain a polymer (B-2).

Synthesis example B-3

A four-necked flask having a capacity of 500 ml was equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer, and nitrogen gas was introduced thereinto. Then, 3 g of the polymer (B-1) obtained in Synthesis example B-1 and 17 g of NMP were charged into a four-necked flask, and the mixture was stirred at room temperature until dissolved. Then, 3 g of the polymer (B-2) obtained in Synthesis example B-2 and 17 g of NMP were added and reacted at 60 ℃ for 6 hours, and after the reaction was completed, the reaction mixture was poured into 1500 ml of water to precipitate the polymer, and the polymer obtained by filtration was washed with methanol and filtered three times, and then placed in a vacuum oven and dried at 60 ℃ to obtain the polymer (B-3).

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display device

Examples 1 to 15 and comparative examples 1 to 5 of the liquid crystal aligning agent, the liquid crystal alignment film, and the liquid crystal display device are described below.

Example 1

a. Liquid crystal aligning agent

The liquid crystal aligning agent of example 1 was prepared by dissolving 100 parts by weight of the compound (a-1) having a maleamic acid group obtained in synthesis example 1 in 2000 parts by weight of N-methyl-2-pyrrolidone (C-1) and 1000 parts by weight of ethylene glycol N-butyl ether (C-2), and stirring the solution at room temperature using a stirring apparatus until the solution was completely dissolved.

b. Liquid crystal alignment film and liquid crystal display assembly

Using the liquid crystal aligning agent obtained above, a liquid crystal display module was produced in the following order. First, a liquid crystal alignment agent was spin-coated on each of two glass substrates having ITO electrodes in a slit-like (slit) pattern with a Line/Space (Line/Space) of 5 μm each. Then, pre-baking was performed on a hot plate at a temperature of 80 ℃ for 2 minutes, and post-baking was performed in a circulating oven at a temperature of 230 ℃ for 15 minutes, thereby forming the liquid crystal alignment film of example 1.

For the two glass substrates with the liquid crystal alignment film formed thereon, one of the two glass substrates was coated with a hot-press adhesive, the other was sprayed with a spacer (spacer) of 4 μm, and then the two glass substrates were bonded together, and then hot-press bonding was performed at a temperature of 150 ℃ under a pressure of 10kg with a hot press. Then, a liquid crystal injector (manufactured by shimadzu, model number ALIS-100X-CH) was used to inject a liquid crystal (manufactured by Merck, model number MLC 6883) having negative dielectric anisotropy, in which 0.1 wt% of 4, 4' -biphenylene methacrylate was added to the liquid crystal as a polymerizable compound, and then the liquid crystal injection port was sealed with an ultraviolet curing adhesive and cured by irradiation with ultraviolet light. Then, an ac power of 20V was applied between the two ITO electrodes, and ultraviolet rays of 30J were irradiated while the liquid crystal was in a driven state, so that the liquid crystal display device of example 1 was obtained. The liquid crystal display device of example 1 was evaluated in the following measurement and evaluation methods, and the results are shown in table 2.

Examples 2 to 15 and comparative examples 1 to 3

The liquid crystal aligning agents, the liquid crystal alignment films, and the liquid crystal display devices of examples 2 to 15 and comparative examples 1 to 3 were respectively prepared in the same steps as example 1, and they were different in that: the kinds of the components and the amounts thereof used were changed as shown in Table 2. The liquid crystal display devices obtained in examples 2 to 15 and comparative examples 1 to 3 were evaluated in the following evaluation manner, and the results are shown in Table 2.

The compounds corresponding to the abbreviations in table 2 are shown below.

Component for short

A-1 Compound having maleamidyl group (A-1)

A-2 Compound having maleamidyl group (A-2)

A-3 Compound having maleamidyl group (A-3)

A-4 Compound having maleamidyl group (A-4)

A-5 Compound having maleamidyl group (A-5)

A-6 Compound having maleamidyl group (A-6)

A-7 Compound having maleamidyl group (A-7)

A-8 Compound having maleamidyl group (A-8)

A-9 Compound having maleamidyl group (A-9)

A-10 Compound having maleamidyl group (A-10)

A-11 Compound having maleamidyl group (A-11)

A-12 Compound having maleamidyl group (A-12)

A-13 Compound having maleamidyl group (A-13)

A-14 Compound having maleamidyl group (A-14)

A-15 Compound having maleamidyl group (A-15)

B-1 Polymer (B-1)

B-2 Polymer (B-2)

B-3 Polymer (B-3)

C-1N-methyl-2-pyrrolidone

C-2 ethylene glycol n-butyl ether

C-3N, N-dimethylacetamide

C-4 gamma-butyrolactone

D-1N, N, N ', N ' -Tetraepoxypropyl-4, 4 ' -diaminodiphenylmethane

D-2N, N, N ', N' -Tetraepoxypropyl-m-xylene diamine

D-33-aminopropyltriethoxysilane

< evaluation mode >

a. Residue of polymerizable compound

A10V AC voltage having a frequency of 60 Hz was applied between the electrodes of the liquid crystal display modules of examples and comparative examples, and the liquid crystal display modules were irradiated with 100,000J/m²Ultraviolet light (ultraviolet light irradiation machine model is KN-SH48K 1; light energy industry manufacturing). Next, the Liquid crystal layer was taken out, and the residual amount (γ) of the polymerizable compound was measured by High Performance Liquid Chromatography (HPLC).

Evaluation criteria for the residual polymerizable compound are as follows.

◎：γ＜500ppm

○：500ppm≤γ＜800ppm

△：800ppm≤γ＜1000ppm

×：γ≤1000ppm

b. Long term reliability

An AC voltage of 10V having a frequency of 60 Hz was applied between the electrodes of the liquid crystal display modules of examples and comparative examples, and the liquid crystal display modules were irradiated with 30,000J/m²Ultraviolet light (ultraviolet light irradiation machine model is KN-SH48K 1; light energy industry manufacturing). Next, the center point of the liquid crystal display element was measured by the crystal rotation method using He-Ne laser using a liquid crystal evaluating apparatus (center precision system, model OMS-CM4RD) according to the method described in "T.J.Scheffer, et al., J.appl.Phys., vol.19, 2013 (1980)"A first pretilt (P1) may be measured. Then, after the liquid crystal display device was left in an oven at 60 ℃ for 200 hours, the same position was measured to obtain a second pretilt angle (P2). Finally, the long-term reliability R is calculated by the following formula (1):

r (°) ═ P1-P2| formula (1)

Evaluation criteria for long-term reliability are as follows.

◎：R＜1.0

○：1.0≤R＜1.5

△：1.5≤R＜2.0

×：R＞2.0

< evaluation results >

As is apparent from table 2, the liquid crystal display devices (comparative examples 1 to 5) having no bridge structure represented by formula (1) had a problem of residual polymerizable compound, as compared with the liquid crystal display devices (examples 1 to 15) produced from the liquid crystal alignment film having a bridge structure represented by formula (1).

In addition, when the diamine compound (a2-1) is used in an amount of 5 to 70 moles (examples 1 to 7, 9 to 11, and 13 to 15) based on 100 moles of the total amount of the diamine component (a2) used, a liquid crystal display device having less unreacted polymerizable compound remaining in the liquid crystal layer can be obtained.

When the diamine component (a2) contains the diamine compound (a2-2) represented by the formula (3) (example 1, example 2, example 4, example 6 to example 9, example 12 and example 13), the long-term reliability of the liquid crystal display device is more excellent.

In addition, when the liquid crystal alignment film contains the polymer (B) (examples 5, 9, 11, and 14), the long-term reliability of the liquid crystal display device is better.

In summary, the liquid crystal alignment film of the present invention includes a specific bridging structure, so that there is no problem of residual unreacted compounds in the liquid crystal layer. Furthermore, the liquid crystal alignment film of the present invention does not leave unreacted compounds in the liquid crystal layer due to the bridging structure of the organic group containing the photoreactive group, and has no problem of poor long-term reliability, so that it is suitable for manufacturing liquid crystal alignment films and liquid crystal display devices.

Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited to the embodiments, and various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A liquid crystal alignment film, comprising a bridge structure represented by formula (1):

in the formula (1), T represents an aliphatic, alicyclic or aromatic structure; q represents an organic group containing a photoreactive group, which is a group represented by formula (1-1); k represents an integer of 1 or more;

-R_a-R_b-R_c-R_dformula (1-1)

In the formula (1-1), R_arepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃) -or-N (CH)₃)CO-；

R_bRepresents a linear alkylene group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom, and any of the alkylene groups has a-CH group₂optionally-CF₂-, -CH ═ CH-, or a substituent selected from: -O-, -COO-, -NHCO-, -NH-, carbocyclyl, or heterocyclyl, wherein when two are presentof-CH₂-when substituted by said substituents, said substituents are not adjacent;

R_crepresents-CH₂-、-O-、-NH-、-N(CH₃)-、-CONH-、-NHCO-、-CH₂O-、-COO-、-OCO-、-CON(CH₃)-、-N(CH₃) CO-, carbocyclyl, or heterocyclyl;

R_drepresents-CR_e＝CH₂Or a group represented by the following structural formula, R_eRepresents a hydrogen atom or a methyl group which may be substituted by a fluorine atom:

2. the liquid crystal alignment film according to claim 1, wherein the bridging structure is obtained by radical polymerization of a compound (A) having a maleamic acid group, and the compound (A) having a maleamic acid group has 2 or more than 2 maleamic acid groups polymerizable in one molecule.

3. The liquid crystal alignment film according to claim 2, wherein the radical polymerization reaction occurs at a double bond generated after the dehydration ring-closure reaction of the compound (A) having a maleamic acid group.

4. The liquid crystal alignment film according to claim 2, wherein the compound (A) having a maleamic acid group is obtained by reacting a maleic anhydride derivative (a1) and a diamine component (a 2).

5. The liquid crystal alignment film according to claim 4, wherein the diamine component (a2) comprises a diamine compound (a2-1) represented by formula (2):

in the formula (2), R_a、R_b、R_cAnd R_dIs defined as in claim 1_a、R_b、R_cAnd R_dThe same definition is applied.

6. The liquid crystal alignment film according to claim 4, wherein the diamine component (a2) further comprises a diamine compound (a2-2) represented by formula (3):

in the formula (3), R₃represents-O-),

Or

in the formula (3-1),

R₅represents a hydrogen atom, a fluorine atom or a methyl group;

R₆、R₇or R₈Each independently represents a single bond, -O-, or,

Or an alkylene group having 1 to 3 carbon atoms;

R₉to represent

Wherein R is₁₁And R₁₂Each independently represents a hydrogen atom, a fluorine atom or a methyl group;

R₁₀represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 12 carbon atoms, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, -OCH₂F、-OCHF₂or-OCF₃；

a represents 1 or 2;

b. c and d each independently represent an integer of 0 to 4;

e. f and g each independently represent an integer of 0 to 3, and e + f + g is not less than 1;

h and i each independently represent 1 or 2;

when there are more than one R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂In the case of (2), a plurality of R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Or R₁₂Each being the same or different.

7. The liquid crystal alignment film according to claim 5, wherein the diamine compound (a2-1) is used in an amount of 5 to 70 moles based on 100 moles of the diamine component (a 2).

8. The liquid crystal alignment film according to claim 6, wherein the diamine compound (a2-2) is used in an amount of 3 to 50 moles based on 100 moles of the diamine component (a 2).

9. A liquid crystal display element comprising the liquid crystal alignment film according to any one of claims 1 to 8.

10. A method of manufacturing a liquid crystal display module, comprising:

forming liquid crystal alignment films according to any one of claims 1 to 8 on a pair of substrates including conductive films, respectively;

disposing the substrate on which the liquid crystal alignment film is formed so that the liquid crystal alignment film faces the substrate;

injecting a liquid crystal composition between the substrates to form a liquid crystal cell; and

applying a voltage between the conductive films, and irradiating the liquid crystal cell with light in a state where the voltage is applied.