WO2016125870A1

WO2016125870A1 - Liquid crystal orienting agent, liquid crystal display element, and method for producing liquid crystal display element

Info

Publication number: WO2016125870A1
Application number: PCT/JP2016/053413
Authority: WO
Inventors: 暁子若林; 耕平後藤; 章吾檜森
Original assignee: 日産化学工業株式会社
Priority date: 2015-02-06
Filing date: 2016-02-04
Publication date: 2016-08-11
Also published as: CN107209423A; TW202043338A; TWI776209B; JP6662306B2; KR20170109604A; KR102502321B1; CN111944542A; TW201634533A; CN107209423B9; TWI707887B; KR20230027326A; JPWO2016125870A1; KR102607979B1; CN107209423B

Abstract

Provided are a liquid crystal orienting agent having good residual DC characteristics, a liquid crystal oriented film, a liquid crystal display element, and a method for manufacturing a liquid crystal display element. The liquid crystal orienting agent is intended for use in a liquid crystal display element obtained by photoirradiation of a liquid crystal cell in which a pair of substrates having conductive films that are coated with a liquid crystal orienting agent and heated to form a coating film are arranged in opposition with the coating films facing across an intervening liquid crystal layer. The liquid crystal orienting agent contains the following component (A), component (B), and an organic solvent. Component (A): at least one polymer selected from the group consisting of polyimide precursors having side chains for causing liquid crystals to orient vertically, and polyimides that are imides of such polyimide precursors. Component (B): at least one polymer selected from the group consisting of polyimide precursors that are reaction products of a diamine component and a tetracarboxylic dianhydride component that contains a tetracarboxylic dianhydride selected from the following equations (1) and (1'), and polyimides that are imides of such polyimide precursors. When component (B) has side chains for causing liquid crystals to orient vertically, the component may be a polymer identical to that of component (A). (j and k are 0 or 1, and x and y are single bonds, carbonyl groups, or the like.)

Description

Liquid crystal aligning agent, liquid crystal display element, and manufacturing method of liquid crystal display element

The present invention relates to a liquid crystal aligning agent, a liquid crystal display element, and a method for manufacturing a liquid crystal display element that can be used for manufacturing a vertical alignment type liquid crystal display element manufactured by irradiating liquid crystal molecules with ultraviolet rays.

In a liquid crystal display element of a method (also referred to as a vertical alignment (VA) method) in which liquid crystal molecules aligned perpendicular to a substrate are responded by an electric field, a voltage is applied to the liquid crystal molecules during the manufacturing process. Some include a step of irradiating with ultraviolet rays.

In such a vertical alignment type liquid crystal display element, a photopolymerizable compound is added to a liquid crystal composition in advance and used together with a vertical alignment film such as polyimide to irradiate ultraviolet rays while applying a voltage to a liquid crystal cell. A PSA (Polymer sustained Alignment) element (see Patent Document 1 and Non-Patent Document 1) is known which has a high response speed of liquid crystal.
Usually, the tilting direction of the liquid crystal molecules in response to the electric field is controlled by a protrusion provided on the substrate, a slit provided in the display electrode, or the like. When a photopolymerizable compound is added to the liquid crystal composition and ultraviolet rays are applied while applying voltage to the liquid crystal cell, a polymer structure in which the tilted direction of the liquid crystal molecules is stored is formed on the liquid crystal alignment film. Therefore, it is said that the response speed of the liquid crystal display element is faster than the method of controlling the tilt direction of the liquid crystal molecules only by the protrusions and slits.

On the other hand, it has been reported that the response speed of the liquid crystal display element is increased by adding the photopolymerizable compound to the liquid crystal alignment film instead of the liquid crystal composition (SC-PVA liquid crystal display) Patent Document 2). Furthermore, in recent years, further high-speed response of PSA type liquid crystal panels has been studied. As such a technique, a monofunctional liquid crystal compound having one or more of an alkenyl group and a fluoroalkenyl group (hereinafter referred to as “a alkenyl group”) , Also referred to as “alkenyl liquid crystal”) has been attempted (see Patent Documents 2 to 5). However, when an alkenyl liquid crystal is introduced into a liquid crystal composition, the voltage holding ratio and DC charge storage characteristics (residual DC characteristics) tend to deteriorate as the reliability decreases (see Patent Documents 6 to 9).

Especially, the deterioration of the residual DC characteristics causes burn-in that leads to the deterioration of the display characteristics (afterimage) of the liquid crystal display element. Conventional methods for improving residual DC are known to promote charge transfer by electrostatic interaction such as salt formation or hydrogen bonding between a carboxy group and a nitrogen-containing aromatic heterocycle. However, at present, there are few knowledges on how to improve the residual DC when using alkenyl liquid crystals (see Patent Documents 10 to 12).

Japanese Unexamined Patent Publication No. 2003-307720 International Publication No. 2009/050869 Japanese Unexamined Patent Publication No. 2010-285499 Japanese Unexamined Patent Publication No. 9-104644 Japanese Unexamined Patent Publication No. 6-108053 European Patent 0-0474-062 US Pat. No. 6,066,268 Japanese Unexamined Patent Publication No. 2014-240486 Japanese Unexamined Patent Publication No. 2014-224260 Japanese Unexamined Patent Publication No. 9-316200 Japanese Unexamined Patent Publication No. 10-104633 Japanese Unexamined Patent Publication No. 8-76128

An object of the present invention is to improve the response speed of a vertical alignment type liquid crystal display device, and further to use a liquid crystal composition containing an electrical property and a residual DC property of the obtained liquid crystal display device, particularly an alkenyl liquid crystal. The present invention provides a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element, and a method for manufacturing a liquid crystal display element that can improve residual DC characteristics.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved, and have completed the present invention having the following gist.

1. A liquid crystal aligning agent applied to a conductive film of a pair of substrates having a conductive film and heated to form a coating film on a liquid crystal cell disposed opposite to the coating film so that the coating film faces the liquid crystal layer. A liquid crystal aligning agent for a liquid crystal display element formed by irradiation and containing the following component (A), component (B), and an organic solvent.
Component (A): at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystal and polyimide which is an imide of the polyimide precursor.
Component (B): a polyimide precursor which is a reaction product of a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride selected from the following formulas (1) and (1 ′) and a diamine component, and the polyimide At least one polymer selected from the group consisting of polyimides that are imidized precursors. However, the component (B) may be the same polymer as the component (A) when it has a side chain for vertically aligning the liquid crystal.

(Wherein j and k are each independently 0 or 1, and x and y are each independently a single bond, carbonyl, ester, phenylene, sulfonyl or amide group.)
2. 2. The liquid crystal aligning agent according to 1, wherein the liquid crystal layer in the liquid crystal display element is a liquid crystal layer containing a liquid crystal compound having an alkenyl liquid crystal.
3. In the above 1 or 2, the content ratio of the component (A) and the component (B) is (A) component: (B) component = X: (10−X) (X = 1 to 9) in mass ratio. The liquid crystal aligning agent of description.
4). The side chain for vertically aligning the liquid crystal in the component (A) is represented by the following formula (a):
4. The liquid crystal aligning agent according to any one of items 1 to 3.

(L, m and n each independently represents an integer of 0 or 1, R ¹ represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, —NHCO—, —CONH. -Or an alkylene-ether group having 1 to 3 carbon atoms, R ² , R ³ and R ⁴ each independently represents a phenylene group, a fluorine-containing phenylene group or a cycloalkylene group, and R ⁵ is a hydrogen atom , An alkyl group having 2 to 24 carbon atoms, a fluorine-containing alkyl group having 2 to 24 carbon atoms, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent heterocycle, or a monovalent cyclic substituent comprising the same. Represents.)
5. 5. A liquid crystal alignment film having a thickness of 5 to 300 nm obtained from the liquid crystal aligning agent according to any one of 1 to 4 above.
6). 6. A liquid crystal display device comprising the liquid crystal alignment film as described in 5 above.
7). The liquid crystal aligning agent containing the following (A) component, (B) component, and an organic solvent is apply | coated on this electrically conductive film of a pair of board | substrate which has an electrically conductive film, respectively, Then, this is heated and a coating film is formed. A second step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed to face each other with the coating film facing each other through a liquid crystal layer, and the liquid crystal cell. A method for manufacturing a liquid crystal display element, comprising a third step of irradiating light.
Component (A): at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystal and polyimide which is an imidized product of this polyimide precursor.
Component (B): a polyimide which is a reaction product of a tetracarboxylic dianhydride component containing at least one tetracarboxylic dianhydride selected from the group consisting of the following formulas (1) and (1 ′) and a diamine At least one polymer selected from the group consisting of a precursor and a polyimide which is an imidized product of this polyimide precursor. However, the component (B) may be the same polymer as the component (A) when it has a side chain for vertically aligning the liquid crystal.

(Wherein j, k, x and y are as described above.)
8). 8. The method for producing a liquid crystal display element according to 7 above, wherein the liquid crystal layer is a liquid crystal layer containing a liquid crystalline compound having an alkenyl liquid crystal.
9. 9. The method for producing a liquid crystal display element according to 7 or 8 above, wherein the ultraviolet irradiation amount is 1 to 50 J / cm ² .
10. 10. The method for producing a liquid crystal display element according to any one of 7 to 9, wherein the liquid crystal display element is a vertical alignment type display element.

According to the present invention, it is possible to provide a vertical alignment type liquid crystal display element in which the response speed of the liquid crystal is fast and the residual DC is small.

The liquid crystal aligning agent used for the manufacturing method of this invention is a liquid crystal aligning agent for vertical alignment type liquid crystal display elements containing the said (A) component, (B) component, and an organic solvent. However, the component (B) may be the same polymer as the component (A).
In the present invention, the liquid crystal alignment agent is a solution for producing a liquid crystal alignment film, and the liquid crystal alignment film is a film for aligning liquid crystals in a predetermined direction, in the present invention, in the vertical direction. .

[(A) component]
The liquid crystal aligning agent of the present invention comprises, as component (A), at least one heavy selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystals and a polyimide that is an imidized product of this polyimide precursor. Contains coalescence.

<Side chains that align liquid crystal vertically>
The side chain for vertically aligning the liquid crystal is not limited as long as the liquid crystal can be aligned vertically with respect to the substrate. For example, a long-chain alkyl group, a group having a ring structure or a branched structure in the middle of a long-chain alkyl group, a steroid group, a group in which some or all of hydrogen atoms of these groups are replaced with fluorine atoms, and the like can be mentioned. The side chain that vertically aligns the liquid crystal may be directly bonded to the main chain of polyamic acid or polyimide, or may be bonded through an appropriate bonding group. Examples of the side chain for vertically aligning the liquid crystal include those represented by the following formula (a).

(In the formula (a), l, m and n each independently represents an integer of 0 or 1, and R ¹ represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, —NHCO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms, and R ² , R ³ , and R ⁴ each independently represent a phenylene group, a fluorine-containing phenylene group, or a cycloalkylene group. R ⁵ is a hydrogen atom, an alkyl group having 2 to 24 carbon atoms, a fluorine-containing alkyl group having 2 to 24 carbon atoms, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent heterocyclic ring, or a combination thereof. Represents a monovalent macrocyclic substituent.)

R ¹ in the above formula (a) is preferably —O—, —COO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms from the viewpoint of ease of synthesis.

R ² , R ³ and R ⁴ in formula (a) are l, m, n, R ² and R shown in Table 1 below from the viewpoint of ease of synthesis and ability to align liquid crystals vertically. A combination of ³ and R ⁴ is preferred.

When at least one of l, m and n is 1, R ⁵ in formula (a) is preferably a hydrogen atom, an alkyl group having 2 to 14 carbon atoms, or a fluorine-containing alkyl group having 2 to 14 carbon atoms. And more preferably a hydrogen atom, an alkyl group having 2 to 12 carbon atoms, or a fluorine-containing alkyl group having 2 to 12 carbon atoms. When l, m and n are all 0, R ⁵ is preferably an alkyl group having 12 to 22 carbon atoms, a fluorine-containing alkyl group having 12 to 22 carbon atoms, a monovalent aromatic ring, a monovalent fatty acid. An aromatic ring, a monovalent heterocyclic ring, or a monovalent macrocyclic substituent comprising them, more preferably an alkyl group having 12 to 20 carbon atoms or a fluorine-containing alkyl group having 12 to 20 carbon atoms.

In the polyimide or polyimide precursor used in the present invention, the content of the side chain for vertically aligning the liquid crystal is not particularly limited as long as the liquid crystal alignment film can vertically align the liquid crystal. However, in a liquid crystal display device having a liquid crystal alignment film, if it is desired to increase the response speed of the liquid crystal, the content of the side chain that vertically aligns the liquid crystal within the range in which the vertical alignment can be maintained is possible. As few as possible is preferable.

Note that the ability of a polymer having a side chain that vertically aligns the liquid crystal to vertically align the liquid crystal varies depending on the structure of the side chain that vertically aligns the liquid crystal. Generally, as the content of the side chain that vertically aligns the liquid crystal increases, the ability to align the liquid crystal vertically increases, and decreases as the content decreases. In addition, side chains having a cyclic structure tend to have a higher ability to orient liquid crystal vertically than side chains having no cyclic structure.

<Production method of component (A)>
A component (A) which is at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning such a liquid crystal and a polyimide obtained by imidizing this polyimide precursor is produced. The method is not particularly limited. For example, in a method for obtaining a polyamic acid by a reaction between a diamine and a tetracarboxylic dianhydride, a diamine having a side chain for vertically aligning liquid crystals may be copolymerized with the tetracarboxylic dianhydride.

Examples of the diamine having a side chain for vertically aligning the liquid crystal include a long-chain alkyl group, a group having a ring structure or a branched structure in the middle of the long-chain alkyl group, a steroid group, and part or all of hydrogen atoms of these groups A diamine having a side chain with a group in which is substituted with a fluorine atom, for example, a diamine having a side chain represented by the above formula (a). More specifically, for example, diamines represented by the following formulas (2), (3), (4) and (5) can be exemplified, but the invention is not limited thereto.

(The definitions of l, m, n, and R ¹ to R ⁵ in Formula (2) are the same as those in Formula (a) above.)

(In Formula (3) and Formula (4), A ₁₀ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , A ₁₁ represents a single bond or a phenylene group, a represents the same structure as a side chain for vertically aligning the liquid crystal represented by the above formula (a), and a ′ is represented by the above formula (a). (This represents a divalent group having a structure in which one hydrogen atom or the like is removed from the same structure as the side chain for vertically aligning the liquid crystal.)

(In the formula (5), A ₁₄ is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₁₅ is a 1,4-cyclohexylene group or a 1,4-phenylene group. A ₁₆ is an oxygen atom or —COO— * (where a bond marked with “*” is bonded to A ₁₅ ), and A ₁₇ is an oxygen atom or —COO— * (where “*” Is a bond with (CH ₂ ) a ₂ ). A ₁ is 0 or an integer of 1, a ₂ is an integer of 2 to 10, and a ₃ is 0 Or an integer of 1.)

Binding positions of the two amino group (-NH ₂₎ in equation (2) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the structure of the formula (2) include diamines represented by the following formulas [A-1] to [A-24], but are not limited thereto.

(In the formulas [A-1] to [A-5], A ₁ is an alkyl group having 2 to 24 carbon atoms or a fluorine-containing alkyl group having 2 to 24 carbon atoms.)

(In Formula [A-6] and Formula [A-7], A ₂ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and ₃ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, a fluorine-containing alkyl group having 1 to 22 carbon atoms, or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.

(In the formulas [A-8] to [A-10], A ₄ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, or —CH ₂ —, and A ₅ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

(In Formula [A-11] and Formula [A-12], A ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ —, —O—, or —NH—, and A ₇ represents fluorine group, cyano group, trifluoromethane group, nitro group, azo group, formyl group, acetyl group, acetoxy Group or hydroxyl group.)

(In Formula [A-13] and Formula [A-14], A ₈ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

(In the formulas [A-15] and [A-16], A ₉ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

Specific examples of the diamine represented by the formula (3) include diamines represented by the following formulas [A-25] to [A-30], but are not limited thereto.

(In the formulas [A-25] to [A-30], A ₁₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or It indicates _{-NH-, a 13} represents an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms of 1 to 22 carbon atoms.)

Specific examples of the diamine represented by the formula (4) include diamines represented by the following formulas [A-31] to [A-32], but are not limited thereto.

Among these, [A-1], [A-2], [A-3], [A-4], [A-5], from the viewpoint of the ability to align the liquid crystal vertically and the response speed of the liquid crystal Diamines of [A-25], [A-26], [A-27], [A-28], [A-29], or [A-30] are preferred.

The above diamines can be used alone or in combination of two or more depending on the liquid crystal alignment properties, pretilt angle, voltage holding characteristics, accumulated charge and the like when the liquid crystal alignment film is formed.

Such a diamine having a side chain for vertically aligning the liquid crystal is preferably used in an amount of 5 to 50 mol% of the diamine component used for the synthesis of the component (A) which is a polyamic acid, more preferably 10 to It is 40 mol%, particularly preferably 15 to 30 mol%. When the amount of the diamine having a side chain for vertically aligning the liquid crystal is 5 to 50 mol% of the diamine component used for the synthesis of the polyamic acid, it is particularly excellent in terms of the ability to fix the vertical alignment.

In addition, as long as the effect of this invention is not impaired, other diamines other than the diamine which has the side chain which orients the said liquid crystal vertically can be used together as a diamine component for polyamic acid. Specifically, for example, p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl- m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2, 4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl 3,3′-dihydroxy-4,4′-diaminobiphenyl, 3,3′-dicarboxy-4,4′- Aminobiphenyl, 3,3′-difluoro-4,4′-biphenyl, 3,3′-trifluoromethyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2′-diaminodiphenylmethane, 2, 3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4 ' -Sulphonyldianiline, 3,3'-sulfonyl Aniline, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3 , 3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl ( 4,4'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) Amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diamino Benzophenone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2′-diaminobenzophenone, 2,3′-diaminobenzophenone, 1,5-diaminonaphthalene, 1, 6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2- Bis (4-aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 1, 4-bis (4aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3 -Diethyl-4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, , 3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 '-[1,4-phenylenebis (Methylene)] dianiline, 4,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,4 ′-[1,4-phenylenebis (methylene)] dianiline, 3,4 ′-[1, 3-phenylenebis (methylene)] dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] dianiline, 1 4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3- Phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate) 1,3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) iso Phthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N '-(1,3-phenylene) bis (4-aminobenzamide), N, N'-(1,4-phenylene) bis (3-aminobenzamide), N, N '-(1,3-phenylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis (4-aminophenyl) isophthal Amides, N, N′-bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2,2′- Bis [4- (4-aminophenoxy) phenyl] propane, 2,2′-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2′-bis 4-aminophenyl) hexafluoropropane, 2,2′-bis (3-aminophenyl) hexafluoropropane, 2,2′-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2′- Bis (4-aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, trans-1,4-bis (4 -Aminophenyl) cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis (4-aminophenoxy) methane, 1,2-bis (4-aminophenoxy) ethane, 1,3-bis ( 4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bi (3-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1, 6-bis (3-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7-bis (3-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10-bis (4-aminophenoxy) ) Decane, 1,10-bis (3-aminophenoxy) decane, 1,11-bis (4-aminophenoxy) undecane, 1,11-bis (3-aminophenoxy) ) Aromatic diamines such as undecane, 1,12-bis (4-aminophenoxy) dodecane, 1,12-bis (3-aminophenoxy) dodecane; bis (4-aminocyclohexyl) methane, bis (4-amino-3) Cycloaliphatic diamines such as -methylcyclohexyl) methane; 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1, Aliphatic diamines such as 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane; 1,3-bis [2- (p-aminophenyl) ) Ethyl] urea, 1,3-bis [2- (p-aminophenyl) ethyl] -1-tertiary butyloxycarboni Diamines having a urea structure such as urea; diamines having a nitrogen-containing unsaturated heterocyclic structure such as Np-aminophenyl-4-p-aminophenyl (tertiarybutyloxycarbonyl) aminomethylpiperidine; N-tertiary butoxy A diamine having an N-Boc group such as carbonyl-N- (2- (4-aminophenyl) ethyl) -N- (4-aminobenzyl) amine; a compound represented by the formula (B- And at least one diamine selected from the group consisting of 1) to (B-5) and diamines exemplified as specific examples thereof.

In addition, as other diamines, diamines having a photoreactive side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group, and decomposed by ultraviolet irradiation And a diamine having a site where a radical is generated in the side chain.
Specifically, examples of the diamine having a photoreactive side chain include, but are not limited to, the diamine represented by the following general formula (6).

(In the formula (6), R ⁶ is a single bond, —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—, wherein R ⁷ is a single bond, unsubstituted or substituted with a fluorine atom and having 1 to 20 carbon atoms Represents an alkylene group, and —CH ₂ — in the alkylene group may be optionally replaced by —CF ₂ — or —CH═CH—, and when any of the following groups is not adjacent to each other, Which may be replaced by a group: —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, a divalent carbocycle, or a divalent heterocycle, R ⁸ is Represents a photoreactive group selected from the following formula.)

The bonding position of the two amino groups (—NH ₂ ) in Formula (6) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the diamine having a photoreactive group including at least one selected from the group consisting of a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group are as follows. Examples include, but are not limited to, compounds.

(Wherein J ¹ is a single bond, a bonding group selected from —O—, —COO—, —NHCO—, or —NH—, and J ² is a single bond, or is unsubstituted or substituted by a fluorine atom. Represents an alkylene group having 1 to 20 carbon atoms.)

Examples of the diamine having a side chain that is decomposed by irradiation with ultraviolet rays and generating a radical include the diamine represented by the following general formula (7), but are not limited thereto.

(In the formula, Ar represents an aromatic hydrocarbon group selected from phenylene, naphthylene, and biphenylene, which may be substituted with an organic group, and a hydrogen atom may be replaced with a halogen atom. R ⁹ And R ¹⁰ are each independently an alkyl group or alkoxy group having 1 to 10 carbon atoms, and T ₁ and T ₂ are each independently a single bond, —O—, —S—, —COO—, — OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON (CH ₃ ) —, or —N (CH ₃ ) CO—, S Is a single bond, or an alkylene group having 1 to 20 carbon atoms that is unsubstituted or substituted by a fluorine atom (provided that —CH ₂ — or CF ₂ — in the alkylene group is optionally substituted with —CH═CH—). Well, the following In the case where any group is not adjacent to each other, these groups may be substituted; —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, divalent A carbocyclic ring or a divalent heterocyclic ring), and Q represents the following structure.)

(Wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ¹¹ represents —CH ₂ —, —NR—, —O—, or —S—).

The bonding position of the two amino groups (—NH ₂ ) in the above formula (7) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.
In view of easiness of synthesis, high versatility, characteristics and the like, the structure represented by the following formula is most preferable, but is not limited thereto.

(In the formula, n is an integer of 2 to 8.)

The above-mentioned other diamines can be used alone or in combination of two or more according to properties such as liquid crystal orientation, pretilt angle, voltage holding property, and accumulated charge when the liquid crystal alignment film is formed.

The tetracarboxylic dianhydride to be reacted with the diamine component in the synthesis of polyamic acid is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2, 3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyl Tetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-di Carboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyph) Nyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3 , 4-dicarboxyphenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3 4-cyclobutanetetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexane Tetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3 -Cyclobutanetetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic Acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, bicyclo [4,3,0] nonane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4, 0] decane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] decane-2,4,8,10-tetracarboxylic acid, tricyclo [6.3.0.0 <2, 6>] Undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4 -Tetrahydraphthalene-1,2-dicarboxylic acid, bicyclo [2,2,2] oct-7-ene-2,3,5,6-tetracarboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodeca-4,5,9,10-tetracarboxylic acid, 3, Examples thereof include dianhydrides of tetracarboxylic acids such as 5,6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic acid and 1,2,4,5-cyclohexanetetracarboxylic acid. Of course, tetracarboxylic dianhydride may be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

In obtaining a polyamic acid by reaction of a raw material diamine (also referred to as “diamine component”) and a raw material tetracarboxylic dianhydride (also referred to as “tetracarboxylic dianhydride component”), it is well known. The synthesis method can be used. In general, a diamine component and a tetracarboxylic dianhydride component are reacted in an organic solvent. The reaction between the diamine component and the tetracarboxylic dianhydride component is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

The organic solvent used in the above reaction is not particularly limited as long as the generated polyamic acid dissolves. Furthermore, even if it is an organic solvent in which a polyamic acid does not melt | dissolve, you may mix and use the said solvent in the range which the produced | generated polyamic acid does not precipitate. In addition, since the water | moisture content in an organic solvent inhibits a polymerization reaction and also causes the produced polyamic acid to hydrolyze, it is preferable to use what dehydrated and dried the organic solvent.
Examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2 -Pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ- Butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve Tate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene Glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol Recall monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3- Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether , Dioxane, n-hexane, n-pentane, n-octane, diethyl ether , Cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3 -Methyl ethyl ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl- Examples include 2-pentanone and 2-ethyl-1-hexanol. These organic solvents may be used alone or in combination.

When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is used as it is or in an organic solvent. A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. is mentioned, You may use any of these methods. In addition, when the diamine component or tetracarboxylic dianhydride component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. The body may be mixed and reacted to form a high molecular weight body.

The temperature at the time of reacting the diamine component and the tetracarboxylic dianhydride component can be selected arbitrarily, and is, for example, in the range of −20 to 150 ° C., preferably −5 to 100 ° C. The reaction can be performed at an arbitrary concentration. For example, the total amount of the diamine component and the tetracarboxylic dianhydride component is 1 to 50% by mass, preferably 5 to 30% by mass with respect to the reaction solution. .

In the above polymerization reaction, the ratio of the total number of moles of the tetracarboxylic dianhydride component to the total number of moles of the diamine component can be selected according to the molecular weight of the polyamic acid to be obtained. Similar to the normal polycondensation reaction, the molecular weight of the polyamic acid produced increases as the molar ratio approaches 1.0. A preferred range is 0.8 to 1.2.

The method for synthesizing the polyamic acid used in the present invention is not limited to the above-described method, and, like the general polyamic acid synthesis method, instead of the tetracarboxylic dianhydride, a tetra-structure having a corresponding structure is used. The corresponding polyamic acid can also be obtained by reacting by a known method using a tetracarboxylic acid derivative such as carboxylic acid or tetracarboxylic acid dihalide.

Examples of the method for imidizing the polyamic acid to obtain a polyimide include thermal imidization in which the polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution. The imidation ratio from polyamic acid to polyimide is preferably 30% or more, more preferably 50 to 99%, since the voltage holding ratio can be increased. On the other hand, 70% or less is preferable from the viewpoint of whitening characteristics, that is, from the viewpoint of suppressing the precipitation of the polymer in the varnish. In consideration of both characteristics, 50 to 80% is more preferable.

When the polyamic acid is thermally imidized in the solution, the temperature is 100 to 400 ° C., preferably 120 to 250 ° C., and it is preferably performed while removing water generated by the imidation reaction from the system.

The catalytic imidation of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring at -20 to 250 ° C., preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times the amidic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol times the amido group. 30 mole times. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated. The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, and the like.

When recovering the produced polyamic acid or polyimide from the reaction solution of polyamic acid or polyimide, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation generation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated in a poor solvent and collected by filtration can be dried at normal temperature or under reduced pressure at room temperature or by heating. In addition, when the polymer collected by precipitation is redissolved in an organic solvent and reprecipitation and collection is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

[Component (B)]
The liquid crystal aligning agent of the present invention comprises, as component (B), a tetracarboxylic dianhydride component containing at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1 ′), It contains at least one polymer selected from the group consisting of a polyimide precursor obtained by reaction with diamine and a polyimide obtained by imidizing this polyimide precursor.

When a liquid crystal alignment film using at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1 ′) as a raw material is used, the light irradiation causes a gap between the liquid crystal and the liquid crystal alignment film. The residual DC characteristics can be improved by the interaction that appears to occur.
Examples of the tetracarboxylic dianhydride selected from the above formulas (1) and (1 ′) include, but are not limited to, the following compounds.

At least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1-1) to (1-5) is a tetracarboxylic dianhydride component used for the synthesis of the component (B) which is a polyamic acid. It is preferable to use an amount of 10 to 100% of the above. More preferably, 10 to 60% is used. More preferably, since the voltage holding ratio can be increased, at least one tetracarboxylic dianhydride selected from the group consisting of formula (1-1), formula (1-3), and formula (1-5) is used. The total amount of the tetracarboxylic dianhydride components used for the synthesis of the component (B) is preferably 10 to 40 mol%, more preferably 20 to 40 mol%.

Further, as long as the effects of the present invention are not impaired, other tetracarboxylic dianhydrides described in the component (A) may be used as a raw material for the component (B). For example, the tetracarboxylic dianhydride having an aliphatic group or an alicyclic group is used in an amount of 0 to 90 mol% of the tetracarboxylic dianhydride component used for the synthesis of the component (B) that is a polyamic acid. It is preferable.

The polymer as the component (B) may be made from at least one diamine selected from the group consisting of the following formulas (B-1) to (B-5) as a raw material.

Wherein Y ₁ represents a monovalent organic group having a secondary amine, tertiary amine, or heterocyclic structure, and Y ₂ is a divalent organic having a secondary amine, tertiary amine, or heterocyclic structure. Represents a group.)

At least one diamine having a specific structure with high polarity selected from the above formulas (B-1) to (B-5) is used, or a diamine having a carboxy group and a nitrogen-containing aromatic heterocyclic ring. When one or more diamines are used in combination, charge transfer is promoted by electrostatic interactions such as salt formation and hydrogen bonding, so that the residual DC characteristics can be improved.
Examples of at least one diamine selected from the group consisting of the formulas (B-1) to (B-5) include, but are not limited to, the following diamines.

Furthermore, the polymer which is the component (B) is obtained by using the diamine having a side chain for vertically aligning the liquid crystal used in the component (A) or the other diamine described in the section of the component (A). Also good.

At least one diamine selected from the group consisting of the above formulas (B-1) to (B-5) is used in an amount of 10 to 80 mol% of the diamine component used for the synthesis of the component (B) which is a polyamic acid. It is preferably used, and more preferably 20 to 70 mol%. More preferably, since the voltage holding ratio can be increased, the diamine exemplified above is selected from the group consisting of 3,5-diaminobenzoic acid and 3,5-diamino-N- (pyridin-3-ylmethyl) benzamide. At least one diamine component is preferably used in an amount of 20 to 70 mol% of the total diamine components used for the synthesis of component (B).

In the method for producing the component (B), at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1 ′), and, if necessary, other tetracarboxylic acids A tetracarboxylic dianhydride component containing a dianhydride can be reacted with a diamine component to obtain a polyimide precursor or a polyimide.
The method for producing the component (B) is based on the above-mentioned “component (A)” except that at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1 ′) is used as a raw material. It is the same as “Manufacturing method”.

[Liquid crystal aligning agent]
As described above, the liquid crystal aligning agent of the present invention is at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystals and a polyimide which is an imidized product of this polyimide precursor. A reaction product of a diamine and a tetracarboxylic dianhydride component containing at least one tetracarboxylic dianhydride selected from the group consisting of the above-mentioned formulas (1) and (1 ′) (B) component which is at least 1 sort (s) of polymer chosen from the group which consists of the polyimide precursor which is these, and the polyimide which is an imidation thing of this polyimide precursor, and an organic solvent.
The total content of the component (A) and the component (B) in the liquid crystal aligning agent of the present invention is not particularly limited, but is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably Is 3 to 10% by mass.

The content ratio of the component (A) and the component (B) is not particularly limited. For example, the mass ratio is (A) component: (B) component = X: 10−X (X = 1 to 9). Yes, preferably 2: 8 to 8: 2. However, the component (B) may have the same polymer as the component (A) by having a side chain for vertically aligning the liquid crystal.

Moreover, the liquid crystal aligning agent of this invention may contain other polymers other than (A) component and (B) component. In that case, the content of the other polymer in all the components of the polymer is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass.

The molecular weight of the polymer of the liquid crystal aligning agent is GPC (Gel Permeation Chromatography) in consideration of the strength of the liquid crystal aligning film obtained by applying the liquid crystal aligning agent, workability when forming the coating film, uniformity of the coating film, etc. ), The weight average molecular weight measured by the method is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as it can dissolve or disperse components such as the component (A) and the component (B). For example, the organic solvent which was illustrated by the synthesis | combination of said polyamic acid can be mentioned. Among them, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like are soluble. From the viewpoint of In particular, N-methyl-2-pyrrolidone or N-ethyl-2-pyrrolidone is preferable, but two or more kinds of mixed solvents may be used.

Moreover, it is preferable to mix and use the solvent which improves the uniformity and smoothness of a coating film in the organic solvent with the high solubility of the component of a liquid crystal aligning agent.
Solvents that improve the uniformity and smoothness of the coating include, for example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol Thor, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether , Dipropylene glycol monomethyl Ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether , Dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, dii Butylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, acetic acid Ethyl, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1- Phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2- Ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, 2-ethyl-1-hexanol and the like. A plurality of these solvents may be mixed. When these solvents are used, the content is preferably 5 to 80% by mass, more preferably 20 to 60% by mass based on the total amount of the solvent contained in the liquid crystal aligning agent.

The liquid crystal aligning agent may contain components other than those described above. Examples include a compound that improves the film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, a compound that improves the adhesion between the liquid crystal aligning film and the substrate, and the film strength of the liquid crystal aligning film is further improved. Compound etc. are mentioned.

Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). When these surfactants are used, the ratio of use thereof is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent. 1 part by mass.

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 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, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N′-tetraglycidyl-4, 4′-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, etc. .
In order to further increase the film strength of the liquid crystal alignment film, a phenol compound such as 2,2′-bis (4-hydroxy-3,5-dihydroxymethylphenyl) propane or tetra (methoxymethyl) bisphenol is added. Also good. When these compounds are used, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.

In addition to the above, the liquid crystal aligning agent is added with a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant or conductivity of the liquid crystal aligning film as long as the effects of the present invention are not impaired. May be.

By applying and baking this liquid crystal aligning agent on a substrate, a liquid crystal alignment film for vertically aligning liquid crystals can be formed.
The liquid crystal aligning agent of the present invention is at least one polymer selected from the group consisting of a polyimide precursor having side chains for vertically aligning liquid crystals and a polyimide obtained by imidizing this polyimide precursor (A ) Component and a polyimide precursor obtained by reaction with a tetracarboxylic dianhydride component containing at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1 ′), and Since the component (B) which is at least 1 type of polymer chosen from the group which consists of a polyimide obtained by imidating this polyimide precursor is contained, a residual DC characteristic can be made favorable.

The substrate is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. In the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light such as aluminum can be used as the electrode.

The method for applying the liquid crystal aligning agent is not particularly limited, and examples thereof include a screen printing method, an offset printing method, a flexographic printing method, an inkjet method, a dip method, a roll coater, a slit coater, and a spinner.

The baking temperature of the coating film formed by applying the liquid crystal aligning agent is not limited, and can be performed at any temperature of, for example, 100 to 350 ° C., preferably 120 to 300 ° C., more preferably 150-250 ° C. This baking can be performed with a hot plate, a hot-air circulating furnace, an infrared furnace, or the like.

The thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300 nm, more preferably 10 to 100 nm.

The liquid crystal display element of the present invention is formed of two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal aligning agent provided between the substrate and the liquid crystal layer. The liquid crystal display element of a vertical alignment system comprising a liquid crystal cell having a liquid crystal alignment film formed. Specifically, the liquid crystal alignment agent of the present invention is applied onto two substrates and baked to form a liquid crystal alignment film, and the two substrates are arranged so that the liquid crystal alignment films face each other. This is a vertical alignment type liquid crystal display element comprising a liquid crystal cell produced by sandwiching a liquid crystal layer composed of liquid crystal between the two substrates and irradiating with ultraviolet rays.
Thus, by using the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention and irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays, an interaction occurs between the liquid crystal and the liquid crystal alignment film of the present invention. However, it is considered that the liquid crystal display element has a small liquid crystal residual DC and is unlikely to cause image sticking.

The substrate used in the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, the thing similar to the board | substrate described with the said liquid crystal aligning film can be mentioned.
The liquid crystal display element of the present invention may use a substrate provided with a conventional electrode pattern or protrusion pattern, but by having a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention, Operation is possible even if a substrate with a structure in which 1 to 10 μm line / slit electrode pattern is formed on one side substrate and no slit pattern or projection pattern is formed on the opposite substrate, and the process at the time of device fabrication is simplified And high transmittance can be obtained.

Further, in a high-performance element such as a TFT type element, an element in which an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate is used.

In the case of a transmissive liquid crystal display element, the above-described substrate is generally used. However, in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used. is there. At that time, a material such as aluminum that reflects light may be used for the electrode formed on the substrate.

The liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and baking it, and the details are as described above.

As the liquid crystal composition used in the liquid crystal display element of the present invention, nematic liquid crystal having negative dielectric anisotropy can be used. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, and terphenyl liquid crystal can be used. Moreover, it is preferable to use an alkenyl liquid crystal in combination. A conventionally well-known thing can be used as such an alkenyl type liquid crystal. For example, a compound represented by the following formula can be exemplified, but the present invention is not limited thereto.

The liquid crystal composition constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited as long as it is a liquid crystal material used in a vertical alignment method. For example, MLC-6608, MLC-6609, etc., which are liquid crystal compositions having negative dielectric anisotropy, manufactured by Merck & Co., Inc. can be used. Further, MLC-3022, MLC-3023 (including photopolymerizable compound (RM)) manufactured by Merck Co., Ltd., which are liquid crystal compositions containing alkenyl liquid crystals and having negative dielectric anisotropy, can be used. .

As a method of sandwiching the liquid crystal layer between two substrates, a known method can be exemplified. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers such as beads are dispersed on the liquid crystal alignment film on one substrate, and an adhesive is applied around the substrate, and then a liquid crystal alignment film is formed. There is a method in which the other side is bonded so that the surface on the inner side becomes the inner side, and liquid crystal is injected under reduced pressure for sealing.
Also, a pair of substrates on which a liquid crystal alignment film is formed is prepared, and spacers such as beads are dispersed on the liquid crystal alignment film on one substrate, and then liquid crystal is dropped, and then the side on which the liquid crystal alignment film is formed A liquid crystal cell can also be manufactured by a method in which the other substrate is bonded and sealed with the other surface facing inward. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The step of manufacturing the liquid crystal cell by irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays may be performed at any time after the liquid crystal is sealed. The irradiation amount of ultraviolet rays is, for example, 1 to 60 J / cm ² , preferably 40 J / cm ² or less, and the smaller the irradiation amount of ultraviolet rays, the lower the reliability caused by the destruction of the members constituting the liquid crystal display element.
The wavelength of the ultraviolet rays used is preferably 300 to 500 nm, more preferably 300 to 400 nm.

Further, the irradiation of the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays may be performed while applying a voltage and maintaining the electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p.

In the case of the PSA method in which a polymerizable compound is contained in the liquid crystal, when the ultraviolet light is applied to the liquid crystal alignment film and the liquid crystal layer while applying a voltage, the polymerizable compound reacts to form a polymer. By memorizing the direction in which the molecules are inclined, the response speed of the obtained liquid crystal display element can be increased. Moreover, residual DC characteristics also become favorable by containing (B) component. At this time, it is preferable that the amount of ultraviolet irradiation is small because the ultraviolet irradiation time can be reduced and the production efficiency is increased.

The liquid crystal aligning agent is not only useful as a liquid crystal aligning agent for producing a vertical alignment type liquid crystal display element such as a PSA type liquid crystal display or an SC-PVA type liquid crystal display, but also by a rubbing process or a photo-alignment process. It can also be suitably used for producing a liquid crystal alignment film to be formed.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. The abbreviations of the compounds used below are as follows.
(Acid dianhydride)
BODA: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride.
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride.
PMDA: pyromellitic dianhydride.

(Diamine)
DBA: 3,5-diaminobenzoic acid m-PDA: 1,3-phenylenediamine p-PDA: 1,4-phenylenediamine 3AMPDA: 3,5-diamino-N- (pyridin-3-ylmethyl) benzamide DDM: 4 , 4'-Diaminodiphenylmethane

(In formula DA-6, t represents a trans.)

<Solvent>
NMP: N-methyl-2-pyrrolidone.
BCS: Butyl cellosolve.
<Polyimide molecular weight measurement>
Apparatus: Room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd.
Column: Column manufactured by Shodex (KD-803, KD-805),
Column temperature: 50 ° C.
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) at 10 ml / L),
Flow rate: 1.0 ml / min,
Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight about 9,000, 150,000, 100,000, and 30,000) manufactured by Tosoh Corporation and polyethylene glycol (molecular weight about 12,000, molecular weight manufactured by Polymer Laboratories) 4,000 and 1,000).

<Measurement of imidization ratio>
20 mg of polyimide powder is put into an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.), 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05 mass% TMS mixture) is added, and ultrasonic waves are added. To dissolve completely. This solution was measured for proton NMR at 500 MHz with an NMR measuring apparatus (JNW-ECA500 manufactured by JEOL Datum). The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value. In the following formula, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and α is the NH group of the amic acid in the case of polyamic acid (imidation rate is 0%). It is the number ratio of the reference proton to one proton.
Imidization rate (%) = (1−α · x / y) × 100

<Synthesis Example 1>
BODA (3.30 g, 13.2 mmol), DA-3 (3.35 g, 8.80 mmol), and m-PDA (1.43 g, 13.2 mmol) were dissolved in NMP (29.8 g). The reaction was carried out at 4 ° C. for 4 hours. Thereafter, PMDA (1.85 g, 8.47 mmol) and NMP (9.93 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution X1. The number average molecular weight of this polyamic acid was 13,000, and the weight average molecular weight was 39000.
After adding NMP to this polyamic acid solution (25 g) and diluting to 6.5% by mass, acetic anhydride (5.62 g) and pyridine (4.35 g) were added as an imidization catalyst, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (300 g), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder A. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
NMP (18.0 g) was added to the obtained polyimide powder A (2.0 g), and dissolved by stirring at 70 ° C. for 12 hours. BCS (13.3g) was added to this solution, and liquid crystal aligning agent A1 was obtained by stirring at room temperature for 2 hours.

<Synthesis Example 2>
BODA (3.30 g, 13.2 mmol), DA-3 (3.35 g, 8.80 mmol), and m-PDA (1.43 g, 13.2 mmol) were dissolved in NMP (29.2 g). The reaction was carried out at 4 ° C. for 4 hours. Thereafter, CBDA (1.66 g, 8.47 mmol) and NMP (9.74 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
Except for using this polyamic acid solution (25 g), an imidization reaction was performed in the same manner as in Synthesis Example 1 and the post-reaction treatment was performed to obtain polyimide powder B. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent U1 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder B (2.0 g) was used instead of the polyimide powder A.
Then, BODA (3.75 g, 15 mmol), DA-3 (1.90 g, 4.99 mmol), m-PDA (2.16 g, 20.0 mmol), were dissolved in NMP (29.7 g), and 60 After reacting at 4 ° C. for 4 hours, PMDA (2.10 g, 9.63 mmol) and NMP (9.92 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
Except for using this polyamic acid solution (25 g), an imidization reaction was performed in the same manner as in Synthesis Example 1 and the post-reaction treatment was performed to obtain polyimide powder C. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent L1 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder C (2.0 g) was used instead of the polyimide powder A.
The liquid crystal aligning agent U1 thus obtained was mixed as a first component with 5.0 g, and the liquid crystal aligning agent L1 as a second component was mixed with 5.0 g to obtain a liquid crystal aligning agent A2.

<Synthesis Example 3>
BODA (22.5 g, 90.0 mmol), DA-4 (62.1 g, 158 mmol), p-PDA (14.6 g, 135 mmol), 3AMPDA (38.16, 157 mmol) were dissolved in NMP (620 g). After reacting at 55 ° C. for 2 hours, CBDA (68.4 g, 349 mmol) and NMP (102 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (85 g) and diluting to 6.5% by mass, acetic anhydride (18.87 g) and pyridine (5.85 g) were added as imidation catalysts, and the reaction was carried out at 50 ° C. for 3 hours. I let you. This reaction solution was poured into methanol (1000 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder D. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent U2 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder D (2.0 g) was used instead of the polyimide powder A.
Next, BODA (123 g, 491 mmol), DBA (127 g, 837 mmol), DA-1 (60.7 g, 148 mmol) were dissolved in NMP (1246 g), reacted at 55 ° C. for 2 hours, and then PMDA (43. 0 g, 197 mmol) and NMP (172 g) were added and reacted at room temperature for 4 hours, and CBDA (50.6 g, 258 mmol) and NMP (202 g) were further added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (700g) and diluting to 8 mass%, acetic anhydride (172g) and pyridine (54g) were added as an imidation catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (7000 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder E. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent L2 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder E (2.0 g) was used instead of the polyimide powder A.
The obtained liquid crystal aligning agent U2 was mixed with 5.0 g as the first component, and 5.0 g was mixed with the liquid crystal aligning agent L2 as the second component to obtain a liquid crystal aligning agent A3.

<Synthesis Example 4>
BODA (1.80 g, 7.19 mmol), DA-3 (2.74 g, 7.20 mmol), 3AMPDA (0.87 g, 3.59 mmol), and DA-2 (2.38 g, 7.20 mmol) were added to NMP. (29.7 g) and dissolved at 60 ° C. for 4 hours. Thereafter, CBDA (2.10 g, 10.7 mmol) and NMP (9.89 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (25 g) and diluting to 6.5% by mass, acetic anhydride (4.64 g) and pyridine (3.59 g) were added as imidation catalysts, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (300 g), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder F. The imidation ratio of this polyimide was 74%, the number average molecular weight was 12,500, and the weight average molecular weight was 38000.
A liquid crystal aligning agent U3 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder F (2.0 g) was used instead of the polyimide powder A.
BODA (3.15 g, 12.6 mmol), DA-3 (2.40 g, 6.31 mmol), DBA (1.28 g, 8.40 mmol), and 3AMPDA (1.25 g, 6.31 mmol) were then added to NMP. (30.4 g) was dissolved and reacted at 60 ° C. for 4 hours. Thereafter, PMDA (1.79 g, 8.19 mmol) and NMP (10.14 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (25 g) and diluting to 6.5% by mass, acetic anhydride (5.26 g) and pyridine (4.08 g) were added as imidization catalysts, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (300 g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder G. The imidation ratio of this polyimide was 75%, the number average molecular weight was 13000 and the weight average molecular weight was 38500.
A liquid crystal aligning agent L3 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder G (2.0 g) was used instead of the polyimide powder A.
The obtained liquid crystal aligning agent U3 was mixed as a first component with 5.0 g, and the liquid crystal aligning agent L3 as a second component was mixed with 5.0 g to obtain a liquid crystal aligning agent A4.

<Synthesis Example 5>
BODA (3.75 g, 15 mmol), DA-3 (1.90 g, 4.99 mmol), and m-PDA (2.16 g, 20.0 mmol) were dissolved in NMP (29.1 g) at 60 ° C. The reaction was performed for 4 hours. Thereafter, CBDA (1.89 g, 9.64 mmol) and NMP (9.71 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
Except for using this polyamic acid solution (25 g), an imidization reaction was performed in the same manner as in Synthesis Example 1 and the post-reaction treatment was performed to obtain polyimide powder H. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent L4 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder H (2.0 g) was used instead of the polyimide powder A.
The liquid crystal aligning agent U1 obtained in Synthesis Example 2 was mixed as a first component with 5.0 g, and the liquid crystal aligning agent L4 as a second component was mixed with 5.0 g to obtain a liquid crystal aligning agent A5.

<Synthesis Example 6>
BODA (4.12 g, 16.5 mmol), DA-5 (2.87 g, 6.60 mmol), and DBA (2.34 g, 15.4 mmol) were dissolved in NMP (24.8 g) at 80 ° C. The reaction was allowed for 5 hours. Thereafter, CBDA (1.01 g, 5.15 mmol) and NMP (8.30 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (38g) and diluting to 6 mass%, acetic anhydride (8.43g) and pyridine (3.27g) were added as an imidation catalyst, and it was made to react at 100 degreeC for 3 hours. . This reaction solution was poured into methanol (484 g), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder I. The imidation ratio of this polyimide was 73%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent A6 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder I (2.0 g) was used instead of the polyimide powder A.

<Synthesis Example 7>
NMP (10.0 g) was added to the polyamic acid solution X1 (10 g) obtained in Synthesis Example 1, and the mixture was stirred at room temperature for 1 hour, and then BCS (13.3 g) was added, followed by stirring at room temperature for 2 hours. Alignment agent A7 was obtained.

<Synthesis Example 8>
BODA (123 g, 491 mmol), DBA (127 g, 837 mmol), DA-1 (60.7 g, 148 mmol) were dissolved in NMP (1246 g), reacted at 55 ° C. for 2 hours, and then CA-1 (70. 6 g, 197 mmol) and NMP (282 g) were added and reacted at room temperature for 4 hours. CBDA (50.6 g, 258 mmol) and NMP (202 g) were further added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 8% by mass, acetic anhydride (9.15 g) and pyridine (2.84 g) were added as an imidization catalyst and reacted at 80 ° C. for 3 hours. . This reaction solution was poured into methanol (473 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder J. The imidation ratio of this polyimide was 74%, the number average molecular weight was 13500, and the weight average molecular weight was 40000.
A liquid crystal aligning agent L5 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder J (2.0 g) was used instead of the polyimide powder A.
Synthesis Example 3 5.0 g of the obtained liquid crystal aligning agent U2 as a first component and 5.0 g of the liquid crystal aligning agent L5 as a second component were mixed to obtain a liquid crystal aligning agent A8.

<Synthesis Example 9>
BODA (2.38 g, 9.51 mmol), DBA (1.45 g, 9.53 mmol), DA-1 (2.34 g, 5.70 mmol), DA-3 (1.45 g, 3.81 mmol), NMP After dissolving in (30.4 g) and reacting at 55 ° C. for 3 hours, CA-1 (2.04 g, 5.69 mmol) and NMP (8.17 g) were added and reacted at room temperature for 4 hours. CBDA (0.60 g, 3.06 mmol) and NMP (2.38 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.5% by mass, acetic anhydride (7.46 g) and pyridine (2.31 g) were added as an imidation catalyst and reacted at 80 ° C. for 3 hours. I let you. This reaction solution was poured into methanol (465 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder L. The imidation ratio of this polyimide was 75%, the number average molecular weight was 13000 and the weight average molecular weight was 39500.
A liquid crystal aligning agent L6 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder L (2.0 g) was used instead of the polyimide powder A.
Synthesis Example 3 5.0 g of liquid crystal aligning agent U2 obtained as a first component and 5.0 g of liquid crystal aligning agent L6 as a second component were mixed to obtain liquid crystal aligning agent A9.

<Synthesis Example 10>
BODA (2.25 g, 8.99 mmol), DA-2 (2.97 g, 8.99 mmol), and DA-3 (3.43 g, 9.01 mmol) were dissolved in NMP (34.6 g) The reaction was carried out at 4 ° C. for 4 hours. Then, CBDA (1.75 g, 8.92 mmol) and NMP (6.99 g) were added and reacted at 40 ° C. for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.5% by mass, acetic anhydride (7.06 g) and pyridine (2.19 g) were added as imidization catalysts, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (463 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder M. The imidation ratio of this polyimide was 74%, the number average molecular weight was 12500, and the weight average molecular weight was 38500.
A liquid crystal aligning agent U4 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder M (2.0 g) was used instead of the polyimide powder A.
BODA (1.20 g, 4.80 mmol), DBA (1.46 g, 9.59 mmol), 3AMPDA (1.74 g, 7.18 mmol), and DA-3 (2.74 g, 7.20 mmol) were then added to NMP. (28.58 g) was dissolved and reacted at 60 ° C. for 2 hours. Then, PMDA (1.05 g, 4.81 mmol) and NMP (4.19 g) were added and reacted at room temperature for 4 hours. Further, CBDA (2.78 g, 14.18 mmol) and NMP (
11.1 g) was added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.5% by mass, acetic anhydride (8.90 g) and pyridine (2.76 g) were added as an imidization catalyst, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (472 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder N. The imidation ratio of this polyimide was 74%, the number average molecular weight was 13000 and the weight average molecular weight was 39000.
A liquid crystal aligning agent L7 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder N (2.0 g) was used instead of the polyimide powder A.
3.0 g of the obtained liquid crystal aligning agent U4 as a first component and 7.0 g of the liquid crystal aligning agent L7 as a second component were mixed to obtain a liquid crystal aligning agent A10.

<Synthesis Example 11>
BODA (1.20 g, 4.80 mmol), DBA (1.46 g, 9.59 mmol), 3AMPDA (1.74 g, 7.18 mmol), and DA-3 (2.74 g, 7.20 mmol) were added to NMP (28 .58 g) and reacted at 60 ° C. for 2 hours. Thereafter, CA-2 (1.41 g, 4.79 mmol) and NMP (5.65 g) were added and reacted at room temperature for 4 hours. Further, CBDA (2.78 g, 14.18 mmol) and NMP (11.1 g) were added. In addition, the mixture was reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.5% by mass, acetic anhydride (8.61 g) and pyridine (2.67 g) were added as imidation catalysts, and the reaction was carried out at 80 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (470 g), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder O. The imidation ratio of this polyimide was 75%, the number average molecular weight was 14,000, and the weight average molecular weight was 39000.
A liquid crystal aligning agent L8 was obtained in the same manner as in Synthesis Example 1 except that the obtained polyimide powder O (2.0 g) was used instead of the polyimide powder A.
The liquid crystal aligning agent U4 obtained in Synthesis Example 10 was mixed as a first component with 3.0 g, and the liquid crystal aligning agent L8 as a second component was mixed with 7.0 g to obtain a liquid crystal aligning agent A11.

<Synthesis Example 12>
CA-3 (2.42 g, 10.8 mmol), DA-6 (2.40 g, 9.01 mmol), DA-5 (1.56 g, 3.59 mmol), and DA-7 (2.67 g, 5. 40 mmol) was dissolved in NMP (31.7 g) and reacted at 60 ° C. for 4 hours. Then, PMDA (1.30 g, 5.94 mmol) and NMP (5.20 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.0% by mass, acetic anhydride (2.01 g) and pyridine (1.61 g) were added as imidation catalysts, and the reaction was carried out at 110 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (480 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder P. The imidation ratio of this polyimide was 55%, the number average molecular weight was 11000, and the weight average molecular weight was 32000.
Instead of the polyimide powder A, NMP (18.0 g) was added to the obtained polyimide powder P (2.0 g), and the mixture was dissolved by stirring at 70 ° C. for 12 hours. BCS (13.3g) was added to this solution, and it stirred at room temperature for 2 hours, and obtained liquid crystal aligning agent A12.

<Synthesis Example 13>
CA-3 (3.83 g, 17.1 mmol), DA-6 (2.40 g, 9.01 mmol), DA-5 (1.56 g, 3.59 mmol), and DA-7 (2.67 g, 5. 40 mmol) was dissolved in NMP (31.7 g) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution.
After adding NMP to this polyamic acid solution (40 g) and diluting to 6.0% by mass, acetic anhydride (2.07 g) and pyridine (1.60 g) were added as imidation catalysts, and the reaction was carried out at 110 ° C. for 4 hours. I let you. This reaction solution was poured into methanol (480 g), and the resulting precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder Q. The imidation ratio of this polyimide was 55%, the number average molecular weight was 10500, and the weight average molecular weight was 31500.
NMP (18.0 g) was added to the obtained polyimide powder Q (2.0 g), and the mixture was dissolved by stirring at 70 ° C. for 12 hours. BCS (13.3g) was added to this solution, and it stirred at room temperature for 2 hours, and obtained liquid crystal aligning agent U5.
CA-3 (2.96 g, 13.2 mmol), DDM (3.49 g, 17.6 mmol), and DA-7 (2.18 g, 4.41 mmol) were then dissolved in NMP (34.5 g). , Reacted at 60 ° C. for 4 hours. Thereafter, PMDA (1.54 g, 7.04 mmol) and NMP (6.10 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution X2. The number average molecular weight of this polyamic acid was 12500, and the weight average molecular weight was 34000.
After adding NMP (10.0 g) to the obtained polyamic acid solution X2 (10 g) and stirring at room temperature for 1 hour, BCS (13.3 g) was added and the liquid crystal aligning agent L9 was stirred by stirring at room temperature for 2 hours. Obtained.
The liquid crystal aligning agent U5 thus obtained was mixed as a first component with 5.0 g, and the liquid crystal aligning agent L9 as a second component was mixed with 5.0 g to obtain a liquid crystal aligning agent A13.

<Production of liquid crystal cell>
(Example A)
Using the liquid crystal aligning agent A1 obtained in Synthesis Example 1, a liquid crystal cell was prepared according to the procedure shown below. The liquid crystal aligning agent A1 obtained in Synthesis Example 1 is spin-coated on the ITO surface of the ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100 μm × 300 μm and a line / space of 5 μm is formed, and is 80 ° C. After drying for 90 seconds on the hot plate, baking was performed in a hot air circulation oven at 200 ° C. for 20 minutes to form a liquid crystal alignment film having a thickness of 100 nm.
In addition, the liquid crystal aligning agent A1 is spin-coated on the ITO surface on which no electrode pattern is formed, dried on an 80 ° C. hot plate for 90 seconds, and then baked in a 200 ° C. hot air circulation oven for 20 minutes. A 100 nm liquid crystal alignment film was formed.
About said 2 board | substrate, after spraying a 4 micrometer bead spacer on the liquid crystal aligning film of one board | substrate, the sealing compound (solvent type thermosetting type epoxy resin) was printed from on it. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was faced inward and bonded to the previous substrate, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-6608 (trade name, manufactured by Merck & Co., Inc.), which is a liquid crystal composition containing no alkenyl-based liquid crystal, was injected into this empty cell by a reduced pressure injection method to produce a liquid crystal cell. The obtained liquid crystal cell was annealed (realignment treatment) for 30 minutes in a circulation oven at 110 ° C.
Thereafter, the liquid crystal cell was irradiated with light under the following conditions, and the voltage holding ratio and residual DC were measured under the following conditions. For comparison, the voltage holding ratio and residual DC were also measured under the same conditions for a liquid crystal cell that was not irradiated with light.

[Light irradiation]
From the outside of the liquid crystal cell, UV was passed through a 365 nm bandpass filter and irradiated with 6 J / cm ² (the lamp used was a USHIO Super High Pressure Mercury Lamp LL, ORC UV Light Measure Model UV-M03A (attachment: UV The illuminance was measured at −35).

[Voltage holding ratio]
The obtained liquid crystal cell was measured by applying a voltage of 1 V for 60 μs at a temperature of 60 ° C. using a VHR-1A manufactured by Toyo Technica Co., Ltd., and measuring a voltage holding ratio after 1667 ms. .

[Evaluation of residual DC]
An AC voltage of 5.8 Vpp and a DC voltage of 1 V are applied to the liquid crystal cell after measuring the voltage holding ratio for 48 hours, and the voltage generated in the liquid crystal cell (residual DC) is obtained by the flicker elimination method immediately after the DC voltage is released. It was. This value serves as an index of afterimage characteristics. When this value is ± 30 mV or less, it can be said that the afterimage characteristics are excellent.

(Example B, Comparative Example A, Reference Example A)
Except for using the liquid crystal aligning agent described in Table 2 instead of the liquid crystal aligning agent A1, a liquid crystal cell irradiated with light was manufactured by performing the same operation as in Example A, and the voltage holding ratio and residual DC were measured. .

(Example 1)
A light-irradiated liquid crystal cell was produced in the same manner as in Example A except that MLC-3022 (trade name of Merck), which is a liquid crystal composition containing an alkenyl liquid crystal, was used instead of MLC-6608. The voltage holding ratio and residual DC were measured.

(Examples 2 to 4, 8 to 14)
Except for using the liquid crystal aligning agent described in Table 3 instead of the liquid crystal aligning agent A1, a liquid crystal cell irradiated with light was manufactured by performing the same operation as in Example 1, and the voltage holding ratio and the residual DC were measured. .

(Comparative Examples 1 and 2)
Except for using the liquid crystal aligning agent described in Table 3 instead of the liquid crystal aligning agent A1, a liquid crystal cell irradiated with light was manufactured by performing the same operation as in Example 1, and the voltage holding ratio and the residual DC were measured. .

(Example 5)
Instead of MLC-6608, MLC-3023 (trade name of Merck), which is a liquid crystal composition containing an alkenyl liquid crystal and RM (photopolymerizable compound), is used, and liquid crystal aligning agent A2 is used instead of liquid crystal aligning agent A1. Further, instead of light irradiation, a liquid crystal cell irradiated with light was manufactured by performing the same operation as in Example A except that the PSA treatment was performed under the following conditions, and the voltage holding ratio and residual DC were measured.
[PSA processing]
With a DC voltage of 15 V applied, UV was applied from the outside of the liquid crystal cell through a 325 nm high-pass filter at 10 J / cm ² (the lamp used was a USHIO Super High Pressure Mercury Lamp LL, ORC UV Light Measure Illuminance was measured with Model UV-M03A (attachment: UV-35). Thereafter, UV (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a UV-FL irradiation apparatus manufactured by Toshiba Lighting & Technology Co., Ltd. in a state where no voltage was applied.

(Examples 15 to 19)
A PSA-treated liquid crystal cell was produced by performing the same operation as in Example 5 except that the liquid crystal aligning agent described in Table 4 was used instead of the liquid crystal aligning agent A2, and the voltage holding ratio and residual DC were measured. .

(Comparative Examples 3 to 4)
A PSA-treated liquid crystal cell was produced by performing the same operation as in Example 5 except that the liquid crystal aligning agent described in Table 4 was used instead of the liquid crystal aligning agent A2, and the voltage holding ratio and residual DC were measured. .

(Example 6)
Example A except that MLC-3022 (trade name of Merck), which is a liquid crystal composition containing an alkenyl liquid crystal, was used instead of MLC-6608, and liquid crystal aligning agent A2 was used instead of liquid crystal aligning agent A1. A liquid crystal cell irradiated with light was manufactured in the same manner, and the liquid crystal cell was annealed for 3 hours in a circulation oven at 150 ° C., and then the voltage holding ratio and residual DC were measured.

(Example 7)
Example A except that MLC-3022 (trade name of Merck), which is a liquid crystal composition containing an alkenyl liquid crystal, was used instead of MLC-6608, and liquid crystal aligning agent A2 was used instead of liquid crystal aligning agent A1. A liquid crystal cell irradiated with light was manufactured by performing the same operation, and the liquid crystal cell was annealed for 3 hours in a circulation oven at 150 ° C., and further irradiated with light under the same conditions. Retention and residual DC were measured.

Table 2 shows the results of using MLC-6608, which is a conventional liquid crystal not containing an alkenyl liquid crystal, as Examples A and B, Comparative Example A, and Reference Example A. In Comparative Example A and Reference Example A that do not use a polymer having a structural unit derived from PMDA, the accumulation of residual DC is suppressed in Reference Example A using a highly polar diamine, which is a conventional technique for reducing residual DC. Has been.
On the other hand, in Example A and Example B using the polymer having a structural unit derived from PMDA, there is a difference in the degree depending on the introduction amount of the structural unit derived from PMDA, but the residual DC is smaller than that in Comparative Example A. It is reduced, and further reduction is seen by light irradiation.
Thus, in MLC-6608, which is a liquid crystal composition that does not contain an alkenyl-based liquid crystal, it is possible to reduce the amount of residual DC accumulated by the conventional method, and furthermore, a liquid crystal containing a polymer having a structural unit derived from PMDA. The alignment film can also be reduced by light irradiation.

Table 3 shows the results using MLC-3022 which is a liquid crystal composition containing an alkenyl liquid crystal. Compared with Table 2, it can be seen that the overall voltage holding ratio is reduced. In Comparative Example 1 and Comparative Example 2, also in Comparative Example 2 using the liquid crystal aligning agent A6 that was effective in residual DC with MLC-6608, the accumulated amount of residual DC was large regardless of the presence or absence of light irradiation. On the other hand, Example 1, Example 2, Example 3, Example 4, Example 8, Example 9, Example 10 using polymers having structural units derived from PMDA, CA-1 or CA-2, In Example 11, Example 12, Example 13, and Example 14, the residual DC in the unirradiated light was large as in Comparative Example 2, but was greatly reduced by performing the light irradiation.
Table 4 shows the results using MLC-3023, which is a liquid crystal composition containing alkenyl liquid crystal and RM. Similar to Table 3, the voltage holding ratio is low compared to Table 2, but Comparative Examples 3 and 4 have a large amount of residual DC accumulated regardless of the presence or absence of the PSA treatment. However, in Examples 5 and 15 to 19 using polymers having structural units derived from PMDA, CA-1 or CA-2, residual DC was greatly reduced by performing the PSA treatment.
Thus, when a liquid crystal composition containing an alkenyl-based liquid crystal is used, the conventional residual DC reduction method is not effective, and a polymer having a structural unit derived from PMDA, CA-1 or CA-2 is used. By using the liquid crystal alignment film including the residual DC, the residual DC is reduced by performing the PSA process.

Similar to the examples shown in Table 3 and Table 4, the polymer having PMDA-derived structural units was used, and factors that can reduce the accumulation of residual DC by light irradiation were examined (Table 5).
In Example 5, when light irradiation was performed using liquid crystal aligning agent A2 containing the polymer which has a structural unit derived from PMDA, residual DC has decreased compared with non-irradiation. Furthermore, when annealing was performed at 150 ^° C. for 3 hours after light irradiation, accumulation of residual DC was confirmed to be the same as the result of non-light irradiation (Example 6).
Since there is almost no change in the voltage holding ratio before and after annealing, it is not considered that the liquid crystal is deteriorated, and it is considered that the interaction generated between the liquid crystal and the liquid crystal alignment film has disappeared due to light irradiation. Furthermore, when light irradiation was performed again in this state (Example 7), the amount of accumulated residual DC was reduced again. From this, it was shown that the interaction between the liquid crystal and the liquid crystal alignment film is generated by the light irradiation, and this can reduce the accumulated amount of residual DC.
From the above, even when a low-reliability liquid crystal composition containing an alkenyl-based liquid crystal is used as in the example, the tetracarboxylic dianhydride (for example, the formula (1) and the formula (1 ′)) (for example, It was found that accumulation of residual DC after light irradiation or after PSA treatment can be reduced by using a liquid crystal alignment film containing a polymer having a structural unit derived from (PMDA).

The liquid crystal display element obtained by the present invention is useful as a vertical alignment type liquid crystal display element such as a PSA liquid crystal display or an SC-PVA liquid crystal display.
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2015-22122 filed on February 6, 2015 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims

A liquid crystal aligning agent applied to a conductive film of a pair of substrates having a conductive film and heated to form a coating film on a liquid crystal cell disposed opposite to the coating film so that the coating film faces the liquid crystal layer. A liquid crystal aligning agent for a liquid crystal display element formed by irradiation and containing the following component (A), component (B), and an organic solvent.
Component (A): at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystal and polyimide which is an imide of the polyimide precursor.
Component (B): a polyimide precursor which is a reaction product of a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride selected from the following formulas (1) and (1 ′) and a diamine component, and the polyimide At least one polymer selected from the group consisting of polyimides that are imidized precursors. However, the component (B) may be the same polymer as the component (A) when it has a side chain for vertically aligning the liquid crystal.

(J and k are each independently 0 or 1, and x and y are each independently a single bond, carbonyl, ester, phenylene, sulfonyl or amide group.)
The liquid crystal aligning agent of Claim 1 whose liquid crystal layer in a liquid crystal display element is a liquid crystal layer containing the liquid crystalline compound which has an alkenyl-type liquid crystal.
The content ratio of the component (A) and the component (B) is, by mass ratio, (A) component: (B) component = X: (10−X) (X = 1 to 9). Liquid crystal aligning agent as described in.
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein a side chain for vertically aligning the liquid crystal in the component (A) is represented by the following formula (a).

(L, m and n each independently represents an integer of 0 or 1, R 1 represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, —NHCO—, —CONH. -Or an alkylene-ether group having 1 to 3 carbon atoms, R 2 , R 3 and R 4 each independently represents a phenylene group, a fluorine-containing phenylene group or a cycloalkylene group, and R 5 is a hydrogen atom , An alkyl group having 2 to 24 carbon atoms, a fluorine-containing alkyl group having 2 to 24 carbon atoms, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent heterocycle, or a monovalent cyclic substituent comprising the same. Represents.)
A liquid crystal alignment film having a film thickness of 5 to 300 nm obtained from the liquid crystal alignment agent according to any one of claims 1 to 4.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 5.
The liquid crystal aligning agent containing the following (A) component, (B) component, and an organic solvent is apply | coated on this electrically conductive film of a pair of board | substrate which has an electrically conductive film, respectively, Then, this is heated and a coating film is formed. A second step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed to face each other with the coating film facing each other through a liquid crystal layer, and the liquid crystal cell A method for manufacturing a liquid crystal display element, comprising: a third step of irradiating the substrate with light.
Component (A): at least one polymer selected from the group consisting of a polyimide precursor having a side chain for vertically aligning liquid crystal and polyimide which is an imidized product of this polyimide precursor.
Component (B): a polyimide which is a reaction product of a tetracarboxylic dianhydride component containing at least one tetracarboxylic dianhydride selected from the group consisting of the following formulas (1) and (1 ′) and a diamine At least one polymer selected from the group consisting of a precursor and a polyimide which is an imidized product of this polyimide precursor. However, the component (B) may be the same polymer as the component (A) when it has a side chain for vertically aligning the liquid crystal.

(Wherein j and k are each independently 0 or 1, and x and y are each independently a single bond, carbonyl, ester, phenylene, sulfonyl or amide group.)
The manufacturing method of the liquid crystal display element of Claim 7 whose liquid crystal layer is a liquid crystal layer containing the liquid crystalline compound which has an alkenyl-type liquid crystal.
The method for producing a liquid crystal display element according to claim 7 or 8, wherein the irradiation amount of ultraviolet rays is 1 to 50 J / cm 2 .
10. The method for producing a liquid crystal display element according to claim 7, wherein the liquid crystal display element is a vertical alignment type display element.