TW202043338A - Liquid crystal orienting agent, liquid crystal display element, and method for producing liquid crystal display element - Google Patents

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 alignment agent, liquid crystal display element and method for manufacturing liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal display element, and a method for manufacturing a liquid crystal display element that can be used in the manufacture of a liquid crystal display element of a vertical alignment method produced by irradiating liquid crystal molecules with ultraviolet rays.

In the liquid crystal display element that responds to the liquid crystal molecules that are vertically aligned to the substrate by an electric field (also called the vertical alignment (VA) method), the manufacturing process includes applying a voltage to the liquid crystal molecules and simultaneously Those who irradiate ultraviolet rays.

This type of vertical alignment type liquid crystal display element is known by adding a photopolymerizable compound to the liquid crystal composition in advance and using it together with a vertical alignment film such as polyimide, applying a voltage to the liquid crystal cell and simultaneously irradiating ultraviolet rays. On the other hand, a PSA (Polymer sustained Alignment) element with a fast response speed of liquid crystal (refer to Patent Document 1 and Non-Patent Document 1).

Generally, the tilt direction of the liquid crystal molecules that have responded to the electric field is controlled by protrusions provided on the substrate or slits provided on the display electrodes. in When a photopolymerizable compound is added to the liquid crystal composition and a voltage is applied to the liquid crystal cell while irradiating ultraviolet rays, a polymer structure that has memorized the tilt direction of the liquid crystal molecules is formed on the liquid crystal alignment film. Compared with the method of controlling the tilt direction of liquid crystal molecules by protrusions or slits, the response speed of the liquid crystal display element becomes faster.

On the other hand, there are reports that even by adding a photopolymerizable compound to the liquid crystal alignment film instead of the liquid crystal composition, the response speed of the liquid crystal display element will become faster (SC-PVA type liquid crystal display) (refer to non- Patent Document 2). In addition, in recent years, higher-speed response of PSA-type liquid crystal panels has been discussed. As this technology, attempts have been made to combine monofunctional liquid crystal compounds having at least one of alkenyl and fluoroalkenyl groups (hereinafter, also It is called "alkenyl-based liquid crystal") and is introduced into the liquid crystal composition (refer to Patent Documents 2 to 5). However, when the alkenyl-based liquid crystal is introduced into the liquid crystal composition, the reliability is lowered (refer to Patent Documents 6 to 9), and the voltage retention rate and the DC charge storage characteristics (residual DC characteristics) tend to deteriorate.

In particular, the deterioration of the residual DC characteristics may cause burn-in which causes deterioration (after-image) of the display characteristics of the liquid crystal display element. As a method for improving residual DC so far, the formation of a salt of a carboxyl group with a nitrogen-containing aromatic heterocyclic ring or the promotion of charge movement by electrostatic interaction, which is called hydrogen bonding, is known. However, there is still little knowledge about methods for improving residual DC when using alkenyl-based liquid crystals as far as the current situation is concerned (refer to Patent Documents 10 to 12).

[Prior technical literature]

〔Patent Literature〕

[Patent Document 1] JP 2003-307720 A

[Patent Document 2] International Publication No. 2009/050869

[Patent Document 3] JP 2010-285499 A

[Patent Document 4] Japanese Patent Application Publication No. 9-104644

[Patent Document 5] Japanese Patent Application Laid-Open No. 6-108053

[Patent Document 6] European Patent No. 0474062 Specification

[Patent Document 7] Specification of U.S. Patent No. 6,066,268

[Patent Document 8] JP 2014-240486 A

[Patent Document 9] JP 2014-224260 A

[Patent Document 10] Japanese Patent Laid-Open No. 9-316200

[Patent Document 11] Japanese Patent Application Laid-Open No. 10-104633

[Patent Document 12] Japanese Patent Application Laid-Open No. 8-76128

〔Non-patent literature〕

[Non-Patent Document 1] K. Hanaoka, SID 04 DIGEST, P.1200-1202

[Non-Patent Document 2] K.H Y.-J. Lee, SID 09 DIGEST, P.666-668

The subject of the present invention is to provide a vertical alignment The response speed of the liquid crystal display element is improved, and the electrical characteristics and residual DC characteristics of the obtained liquid crystal display element can be obtained, especially the residual DC characteristics of the liquid crystal composition when the liquid crystal composition containing the alkenyl liquid crystal is used. Alignment agent, liquid crystal alignment film, liquid crystal display element and manufacturing method of liquid crystal display element.

In order to solve the above-mentioned problems, the inventors of the present invention have found a solution to the above-mentioned problems as a result of careful research and completed the present invention with the following gist.

1. A liquid crystal alignment agent containing the following components (A), (B), and an organic solvent; it is used for liquid crystal display elements, which are formed by irradiating liquid crystal cells with light, and the liquid crystal The unit coats a liquid crystal alignment agent on the conductive film with a pair of conductive films and heats the conductive film to form a substrate with a coating film, interposing the liquid crystal layer so that the coating film is arranged oppositely;

(A) Component: 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 of the polyimide precursor of the polyimide precursor.

(B) Component: selected from polyimide precursors containing reaction products of a tetracarboxylic dianhydride component selected from the following formulas (1) and (1') of tetracarboxylic dianhydride and a diamine component, And at least one polymer of the polyimide group of the polyimide precursor of the polyimide. However, when the component (B) has a side chain that aligns the liquid crystal vertically, it can be the same polymerization as the component (A) Things.

(式中，j及k係各自獨立為0或1，x及y係各自獨立為單鍵、羰基、酯、伸苯基、磺醯基或醯胺基。)

(In the formula, j and k are each independently 0 or 1, and x and y are each independently a single bond, a carbonyl group, an ester, a phenylene group, a sulfonyl group, or an amido group.)

2. The liquid crystal alignment agent according to the above 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. The liquid crystal alignment agent of 1 or 2 above, wherein the content ratio of (A) component and (B) component is (A) component at mass ratio: (B) component = X: (10-X) (X= 1~9).

4. The liquid crystal alignment agent according to any one of 1 to 3 above, wherein the side chain that vertically aligns the liquid crystal in the component (A) is represented by the following formula (a).

(l、m及n係各自獨立表示0或1之整數，R¹表示碳數2~6之伸烷基、-O-、-COO-、-OCO-、-NHCO-、-CONH-、或碳數1~3之伸烷基-醚基，R²、R³、及R⁴係各自獨立表示伸苯基、含氟伸苯基或環伸烷基，R⁵表示氫原子、碳 數2~24之烷基、碳數2~24之含氟烷基、一價之芳香環、一價之脂肪族環、一價之雜環，或由此等所構成之一價之環狀取代物。)

(l, m and n each independently represent an integer of 0 or 1, and R ¹ represents an alkylene group with carbon number 2 to 6, -O-, -COO-, -OCO-, -NHCO-, -CONH-, or The alkylene-ether group of carbon number 1~3, R ² , R ³ , and R ⁴ each independently represent a phenylene group, a fluorine-containing phenylene group or a cyclic alkylene group, and R ⁵ represents a hydrogen atom and a carbon number of 2 ~24 alkyl group, carbon number 2-24 fluorine-containing alkyl group, monovalent aromatic ring, monovalent aliphatic ring, monovalent heterocyclic ring, or monovalent cyclic substituents formed by them .)

5. A liquid crystal alignment film having a film thickness of 5 to 300 nm obtained from the liquid crystal alignment agent of any one of 1 to 4 above.

6. A liquid crystal display element comprising the liquid crystal alignment film of 5 above.

7. A method for manufacturing a liquid crystal display element, characterized by comprising: coating a liquid crystal alignment agent containing the following (A) component, (B) component and an organic solvent on the conductive film on a pair of substrates. On the film, the first step of heating this to form a coating film; the second step of forming one of the aforementioned coating films to interpose the liquid crystal layer on the substrate so that the aforementioned coating films are arranged opposite to each other to construct a liquid crystal cell; The liquid crystal cell performs the third step of light irradiation.

(A) Component: 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 compound of the polyimide precursor.

(B) Component: selected from polyamides containing at least one tetracarboxylic dianhydride component selected from the group consisting of the following formulas (1) and (1'), a reaction product of a tetracarboxylic dianhydride component and a diamine At least one polymer of the amine precursor and the polyimide of the polyimide precursor. However, when the component (B) has a side chain for vertically aligning the liquid crystal, it may be the same polymer as the component (A).

(式中，j、k、x及y係如以上所述。)

(In the formula, j, k, x and y are as described above.)

8. The method for manufacturing a liquid crystal display element according to 7 above, wherein the liquid crystal layer is a liquid crystal layer containing a liquid crystal compound having an alkenyl-based liquid crystal.

9. The method for manufacturing a liquid crystal display element according to 7 or 8, wherein the irradiation amount of ultraviolet rays is 1-50J/cm ² .

10. The method for manufacturing a liquid crystal display element according to any one of 7 to 9 above, wherein the liquid crystal display element is a vertical alignment type display element.

According to the present invention, it is possible to provide a liquid crystal display element of a vertical alignment method with a fast response speed of the liquid crystal and less residual DC.

The liquid crystal alignment agent used in the production method of the present invention is a liquid crystal alignment agent for a vertical alignment type liquid crystal display element containing the above-mentioned (A) component, (B) component and an organic solvent. However, the aforementioned (B) component may be the same polymer as the (A) component.

Furthermore, in the present invention, the liquid crystal alignment agent refers to a solution for making a liquid crystal alignment film, and the liquid crystal alignment film refers to a film used to align the liquid crystal in a predetermined direction, and in the present invention, it is a film used to align the liquid crystal in a vertical direction.

〔(A) Ingredient〕

In the liquid crystal alignment agent of the present invention, as the component (A), a polyimide precursor selected from the group consisting of a polyimide precursor having a side chain that aligns the liquid crystal vertically, and the polyimide compound of the polyimide precursor At least one polymer grouped by amines.

<Side chain for vertical alignment of liquid crystal>

The side chain for vertically aligning the liquid crystal is not limited as long as it has a structure capable of vertically aligning the liquid crystal 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 the long-chain alkyl group, a steroid group, and a group in which part or all of the hydrogen atoms of these groups are substituted with fluorine atoms, and the like. The side chain that aligns the liquid crystal vertically can be directly bonded to the main chain of polyamide acid or polyimide, and can also be bonded via an appropriate bonding group. As a side chain which vertically aligns a liquid crystal, what is represented by following formula (a) is mentioned, for example.

(式(a)中，l、m及n係各自獨立表示0或1之整數， R¹表示碳數2~6之伸烷基、-O-、-COO-、-OCO-、-NHCO-、-CONH-、或碳數1~3之伸烷基-醚基，R²、R³、及R⁴係各自獨立表示伸苯基、含氟伸苯基或環伸烷基，R⁵表示氫原子、碳數2~24之烷基、碳數2~24之含氟烷基、一價之芳香環、一價之脂肪族環、一價之雜環，或由此等所構成之一價之大環狀取代物。)

(In formula (a), l, m, and n each independently represent an integer of 0 or 1, and R ¹ represents an alkylene group with 2-6 carbon atoms, -O-, -COO-, -OCO-, -NHCO- , -CONH-, or C1-C3 alkylene-ether group, R ² , R ³ , and R ⁴ each independently represent phenylene, fluorine-containing phenylene or cycloalkylene, R ⁵ represents A hydrogen atom, an alkyl group with 2-24 carbons, a fluorinated alkyl group with 2-24 carbons, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent heterocyclic ring, or one of these Valence of macrocyclic substitutions.)

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

In addition, from the viewpoint of ease of synthesis and the ability to align liquid crystals vertically, R ² , R ³ and R ⁴ in formula (a) are represented by l, m, n, R ² , R ³ and The combination of R ⁴ is better.

When at least one of l, m and n is 1, R ⁵ in formula (a) is preferably a hydrogen atom, an alkyl group with 2 to 14 carbons, or a fluorine-containing alkyl group with 2 to 14 carbons, more preferably A hydrogen atom, an alkyl group with 2 to 12 carbons, or a fluorinated alkyl group with 2 to 12 carbons. In addition, when l, m and n are all 0, R ⁵ is preferably an alkyl group with 12 to 22 carbons, a fluorinated alkyl group with 12 to 22 carbons, a monovalent aromatic ring, and a monovalent aliphatic ring , A monovalent heterocyclic ring, or a monovalent macrocyclic substituent formed by this, more preferably an alkyl group with 12 to 20 carbons or a fluorinated alkyl group with 12 to 20 carbons.

As long as the content of the side chain that vertically aligns the liquid crystal in the polyimide or polyimide precursor used in the present invention, as long as the liquid crystal alignment film can align the liquid crystal vertically, it is not particularly limited. However, in a liquid crystal display element with a liquid crystal alignment film, when it is desired to make the response speed of the liquid crystal faster, it is better to keep the content of the side chain of the liquid crystal vertical alignment as small as possible within the range of maintaining the vertical alignment.

Furthermore, the ability of a polymer having a side chain to align the liquid crystal to align vertically differs according to the structure of the side chain to align the liquid crystal. Generally speaking, if the content of the side chain in the vertical alignment of the liquid crystal becomes too large, the ability to align the liquid crystal vertically increases, and if it decreases, it decreases. In addition, the side chain having a cyclic structure tends to have a higher ability to align the liquid crystal vertically than a side chain not having a cyclic structure.

<(A) Manufacturing method of ingredient>

To produce at least one polymer selected from the group of polyimide precursors having side chains that align liquid crystals vertically, and polyimides obtained by imidizing the polyimide precursors That is, the method of (A) component is not specifically limited. For example, in the method of obtaining polyamide acid by the reaction of diamine and tetracarboxylic dianhydride, it is only necessary to copolymerize the diamine and the tetracarboxylic dianhydride having a side chain that aligns the liquid crystal vertically.

Examples of diamines having side chains that align liquid crystals vertically include long-chain alkyl groups, groups having cyclic or branched structures in the middle of long-chain alkyl groups, steroid groups, and hydrogen atoms of these groups. The diamine having a side chain such as a group partially or entirely substituted with a fluorine atom is, 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 mentioned, but they are not limited to these.

(式(2)中之l、m、n、及R¹~R⁵之定義係與上述式(a)相同。)

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

(式(3)及式(4)中，A₁₀表示-COO-、-OCO-、-CONH-、-NHCO-、-CH₂-、-O-、-CO-、或-NH-，A₁₁表示單鍵或伸苯基，a表示與上述式(a)所表示之使液晶垂直配向之側鏈為相同之構造，a’係表示從與上述式(a)所表示之 使液晶垂直配向之側鏈為相同之構造中去除一個氫原子等之構造之二價之基。)

(In formulas (3) and (4), A ₁₀ represents -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO-, or -NH-, A ₁₁ represents a single bond or phenylene, a represents the same structure as the side chain that vertically aligns the liquid crystal represented by the above formula (a), and a'represents the vertical orientation of the liquid crystal from the above formula (a) The side chain of the same structure is the divalent base of the structure with one hydrogen atom removed.)

(式(5)中，A₁₄為可被氟原子所取代之碳數3~20之烷基，A₁₅為1,4環伸已基或1,4-伸苯基，A₁₆為氧原子或-COO-＊(但，附加「＊」之鍵結處係與A₁₅結合)，A₁₇為氧原子或-COO-＊(但，附加「＊」之鍵結處係與(CH₂)a₂結合)。又，a₁為0、或1之整數，a₂為2~10之整數，a₃為0、或1之整數。)

(In formula (5), A ₁₄ is an alkyl group with 3 to 20 carbons which can be substituted by a fluorine atom, A ₁₅ is a 1,4-ring ethylene group or 1,4-phenylene group, and A ₁₆ is an oxygen atom Or -COO-* (However, the bonding point with "*" attached is bonded to A ₁₅ ), A ₁₇ is an oxygen atom or -COO-* (However, the bonding point with "*" attached is bonded to (CH ₂ ) a _{2 is} combined). Also, a ₁ is an integer of 0 or 1, a ₂ is an integer of 2-10, and a ₃ is an integer of 0 or 1.)

Formula (2) in the two group (-NH ₂₎ of the bonding position is not limited. Specifically, the binding group relative to the side chain can include positions 2,3, 2,4, 2,5, 2,6, 3,4 on the benzene ring, 3,5 position. Among them, from the viewpoint of reactivity during the synthesis of polyamide acid, the positions 2,4, 2,5 or 3,5 are preferred. If considering the ease of synthesizing the diamine, the 2,4 position or 3,5 position is more preferable.

As a specific structure of the formula (2), diamines represented by the following formulas [A-1] to [A-24] can be exemplified, but they are not limited to these.

(式〔A-1〕~式〔A-5〕中，A₁為碳數2~24之烷基或碳數2~24之含氟烷基。)

(In formula [A-1] ~ formula [A-5], A ₁ is an alkyl group with 2-24 carbons or a fluorinated alkyl group with 2-24 carbons.)

(式〔A-6〕及式〔A-7〕中，A₂表示-O-、-OCH₂-、-CH₂O-、-COOCH₂-、或-CH₂OCO-，A₃表示碳數1~22之烷基、碳數1~22之烷氧基、碳數1~22之含氟烷基或碳數1~22之含氟烷氧基。)

(In formula [A-6] and formula [A-7], A ₂ represents -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, A ₃ represents carbon Alkyl with 1-22, alkoxy with 1-22, fluorine-containing alkyl with 1-22, or fluorine-containing alkoxy with 1-22.)

(式〔A-8〕~式〔A-10〕中，A₄表示-COO-、-OCO-、-CONH- 、-NHCO-、-COOCH₂-、-CH₂OCO-、-CH₂O-、-OCH₂-、或-CH₂-，A₅為碳數1~22之烷基、烷氧基、含氟烷基或含氟烷氧基。)

(Formula [A-8]~Formula [A-10], A ₄ represents -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O -, -OCH ₂ -, or -CH ₂ -, A ₅ is an alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group with 1 to 22 carbon atoms.)

(式〔A-11〕及式〔A-12〕中，A₆表示-COO-、-OCO-、-CONH-、-NHCO-、-COOCH₂-、-CH₂OCO-、-CH₂O-、-OCH₂-、-CH₂-、-O-、或-NH-，A₇為氟基、氰基、三氟甲烷基、硝基、偶氮基、甲醯基、乙醯基、乙醯氧基、或羥基。)

(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-, A ₇ is a fluoro group, a cyano group, a trifluoromethyl group, a nitro group, an azo group, a methanoyl group, an acetyl group, Acetyloxy, or hydroxyl.)

(式〔A-13〕及式〔A-14〕中，A₈為碳數3~12之烷基，1,4-環伸己基之順-反異構係分別為反式異構物。)

(In formula [A-13] and formula [A-14], A ₈ is an alkyl group with 3 to 12 carbon atoms, and the cis-trans isomers of 1,4-cyclohexylene are trans isomers, respectively. )

(式〔A-15〕及式〔A-16〕中，A₉為碳數3~12之烷基，1,4-環伸己基之順-反異構係分別為反式異構物。)

(In formula [A-15] and formula [A-16], A ₉ is an alkyl group with 3 to 12 carbon atoms, and the cis-trans isomers of 1,4-cyclohexylene are trans isomers, respectively. )

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

(式〔A-25〕~式〔A-30〕中，A₁₂表示-COO-、-OCO-、-CONH-、-NHCO-、-CH₂-、-O-、-CO-或-NH-，A₁₃表示碳數1~22之烷基或碳數1~22之含氟烷基。)

(Formula [A-25]~Formula [A-30], A ₁₂ represents -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO- or -NH -, A ₁₃ represents an alkyl group with 1 to 22 carbons or a fluorinated alkyl group with 1 to 22 carbons.)

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

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

The above-mentioned diamines can be used in one type or a mixture of two or more types in response to the liquid crystal orientation, pretilt angle, voltage retention characteristics, accumulated charge and other characteristics when forming the liquid crystal alignment film.

The diamine having the side chain that aligns the liquid crystal vertically is preferably 5-50 mol% of the diamine component used in the synthesis of component (A) using polyamide acid, preferably 10~ 40 mol%, particularly preferably 15-30 mol%. Therefore, when a diamine with a side chain that aligns the liquid crystal vertically is used in an amount of 5-50 mol% of the diamine component used in the synthesis of polyamide acid, it is particularly excellent in the aspect of the immobilization ability of the vertical alignment .

Furthermore, within the range that does not impair the effects of the present invention, polyamide acid can also use diamines other than the above-mentioned diamine having a side chain that vertically aligns the liquid crystal as the diamine component. Specifically, for example, p-phenylene diamine, 2,3,5,6-tetramethyl-p-phenylene diamine, 2,5-dimethyl-p-phenylene diamine Diamine, m-phenylene diamine, 2,4-dimethyl-m-phenylene diamine Amine, 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'-di Aminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoro Methyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl , 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenyl Methane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylmethane Phenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonamide Diphenylamine, 3,3'-sulfonyl diphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl) Silane, dimethyl-bis(3-aminophenyl) silane, 4,4'-sulfodianiline, 3,3'-sulfodianiline, 4,4'-diaminodiphenylamine, 3, 3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diamine) Diphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'- Diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diamine Benzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8- Diaminonaphthalene, 2,5-di Amino naphthalene, 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(4-amine) Phenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4- Aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl) Benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-〔1,4-phenylenebis( Methylene)] diphenylamine, 4,4'-[1,3-phenylene bis(methylene)] diphenylamine, 3,4'-[1,4-phenylene bis(methylene) ]Diphenylamine, 3,4'-〔1,3-phenylenebis(methylene)]diphenylamine, 3,3'-〔1,4-phenylenebis(methylene)]diphenylamine, 3,3'-[1,3-phenylene bis(methylene)] diphenylamine, 1,4-phenylene bis[(4-aminophenyl) ketone], 1,4-phenylene Bis[(3-aminophenyl) ketone], 1,3-phenylene bis[(4-aminophenyl) ketone], 1,3-phenylene bis[(3-amino (Phenyl) ketone], 1,4-phenylene bis(4-aminobenzoate), 1,4-phenylene bis(3-aminobenzoate), 1,3-phenylene Phenyl bis (4-amino benzoate), 1,3-phenylene bis (3-amino benzoate), bis (4-amino phenyl) terephthalate, bis (3 -Aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-extension Phenyl) bis(4-aminobenzylamide), N,N'-(1,3-phenylene) bis(4-aminobenzylamide), N,N'-(1,4-phenylene) Phenyl) bis(3-aminobenzylamide), N,N'-(1,3-phenylene) bis(3-aminobenzylamide), N,N'-bis(4-amino) Phenyl) terephthalamide, N,N'-bis(3-aminobenzene Base) terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis (4-Aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenyl sulfide, 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-amine) Phenyloxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-amino) Phenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-amine Phenyloxy)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)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, etc. Aromatic diamines; bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane and other alicyclic diamines; 1,3-diaminopropane, 1 ,4-Diamino Butane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diamino Aliphatic diamines such as nonane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, etc.; 1,3-bis[2-( p-aminophenyl)ethyl]urea, 1,3-bis[2-(p-aminophenyl)ethyl]-1-tertiary butoxycarbonylurea and other diamines with urea structure ; Np-aminophenyl-4-p-aminophenyl (third-level butoxycarbonyl) aminomethylpiperidine and other diamines with nitrogen-containing unsaturated heterocyclic structure; N-third level Butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine and other diamines with N-Boc groups; (B) below At least one diamine selected from the group of formulas (B-1) to (B-5) described in the item of ingredients, and the diamines exemplified as specific examples thereof; etc.

In addition, as other diamines, for example, a photoreaction containing at least one selected from the group consisting of a methacryl group, an acryl group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamyl group can be mentioned. A diamine with a sexual side chain, and a diamine with a side chain that generates free radicals due to ultraviolet radiation decomposition.

Specifically, for example, the diamine having a photoreactive side chain includes the diamine represented by the following general formula (6), but it is not limited to this.

(式(6)中，R⁶表示單鍵、-CH₂-、-O-、-COO-、-OCO- 、-NHCO-、-CONH-、-NH-、-CH₂O-、-N(CH₃)-、-CON(CH₃)-、或-N(CH₃)CO-，R⁷表示單鍵，或，非取代或被氟原子所取代之碳數1~20之伸烷基，且伸烷基之-CH₂-可任意被-CF₂-或-CH=CH-所取代，在不與以下舉出之任意一個基相鄰時，亦可被此等基所取代；-O-、-COO-、-OCO-、-NHCO-、-CONH-、-NH-、二價之碳環、或二價之雜環。R⁸表示選自下述式之光反應性基。)

(In formula (6), R ⁶ represents 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-, R ⁷ represents a single bond, or, unsubstituted or substituted by a fluorine atom, a C 1-20 alkylene group , And -CH ₂ -of the alkylene group can be optionally substituted by -CF ₂ -or -CH=CH-, and it can also be substituted by these groups when it is not adjacent to any of the groups listed below;- O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, or divalent heterocyclic ring. R ⁸ represents a photoreactive group selected from the following formulae. )

The binding position of the two amino groups (-NH ₂ ) in formula (6) is not limited. Specifically, the binding group relative to the side chain can include positions 2,3, 2,4, 2,5, 2,6, 3,4 on the benzene ring, 3,5 position. Among them, from the viewpoint of the reactivity during the synthesis of polyamide acid, the 2,4 position, 2,5 position, or 3,5 position is also preferred. If considering the ease of synthesizing diamine, the 2,4 position or the 3,5 position is more preferable.

As a diamine containing at least one photoreactive group selected from the group consisting of a methacryl group, an acryl group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamyl group, specifically The ground can include the following compounds, but they are not limited to them.

(式中，J¹為選自單鍵、-O-、-COO-、-NHCO-、或-NH-之結合基，J²表示單鍵，或非取代或被氟原子所取代之碳數1~20之伸烷基。)

(In the formula, J ¹ is a bonding group selected from single bond, -O-, -COO-, -NHCO-, or -NH-, J ² represents a single bond, or the number of carbons that are unsubstituted or substituted by fluorine atoms 1~20 alkylene group.)

The side chain has a diamine that generates free radicals due to decomposition by ultraviolet radiation, and the diamine represented by the following general formula (7) can be mentioned, but it is not limited to this.

(式中，Ar表示選自伸苯基、伸萘基、伸聯苯基之芳香 族烴基，此等亦可經有機基取代，又，氫原子亦可被鹵素原子所取代。R⁹及R¹⁰係各自獨立為碳數1~10之烷基或烷氧基，T₁及T₂係各自獨立為單鍵、-O-、-S-、-COO-、-OCO-、-NHCO-、-CONH-、-NH-、-CH₂O-、-N(CH₃)-、-CON(CH₃)-、或-N(CH₃)CO-，S為單鍵，或非取代或經氟原子所取代之碳數1~20之伸烷基(但伸烷基之-CH₂-或CF₂-可任意被-CH=CH-所取代，在不與以下舉出之任意之基相鄰時，亦可被此等基所取代；-O-、-COO-、-OCO-、-NHCO-、-CONH-、-NH-、二價之碳環、或二價之雜環。)，Q表示下述之構造。)

(In the formula, Ar represents an aromatic hydrocarbon group selected from phenylene, naphthylene, and biphenylene. These can also be substituted by organic groups, and hydrogen atoms can also be substituted by halogen atoms. R ⁹ and R ¹⁰ is each independently an alkyl group or alkoxy group with carbon number 1-10, 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 unsubstituted or An alkylene group with 1-20 carbon atoms substituted by a fluorine atom (but the -CH ₂ -or CF ₂ -of the alkylene group can be arbitrarily substituted by -CH=CH-, which is not compatible with any of the groups listed below When ortho, it can also be substituted by these groups; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic ring, or divalent heterocyclic ring.) , Q represents the following structure.)

(式中，R表示氫原子或碳原子數1~4之烷基，R¹¹表示-CH₂-、-NR-、-O-、或-S-。)

(In the formula, R represents a hydrogen atom or an alkyl group with 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, the binding group relative to the side chain can include positions 2,3, 2,4, 2,5, 2,6, 3,4 on the benzene ring, 3,5 position. Among them, from the viewpoint of the reactivity during the synthesis of polyamide acid, the 2,4 position, 2,5 position, or 3,5 position is also preferred. If considering the ease of synthesis of the diamine, the position 2,4, or the position 3,5 is more preferable.

In particular, in view of ease of synthesis, height of versatility, characteristics, etc., the structure represented by the following formula is the best, but it is not limited to this.

(式中，n為2~8之整數。)

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

In accordance with the characteristics of liquid crystal alignment, pretilt angle, voltage retention characteristics, accumulated charge, etc., when forming the liquid crystal alignment film, the above-mentioned other diamines can be used in one type or in a mixture of two or more types.

In the synthesis of polyamide acid, the tetracarboxylic dianhydride reacted with the above-mentioned diamine component is not particularly limited. Specific examples include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3',4,4'-biphenyl tetracarboxylic acid, 2,3,3', 4'-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether, 3,3',4,4'-benzophenone tetracarboxylic acid, bis(3,4-dicarboxybenzene) Oxy), bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2 ,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyl) Phenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenyl Tetracarboxylic acid, 3,4,9,10-perylene tetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutane tetracarboxylic acid, oxydiphthalate tetracarboxylic acid Acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2 ,3,4-Tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-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-naphthalenesuccinic 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, tricyclic (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-Tetrahydronaphthalene-1,2-dicarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 5-(2 ,5-Dioxotetrahydrofuranyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclic [6,2,1,1,0,2,7] twelve-4 ,5,9,10-tetracarboxylic acid, 3,5,6-tricarboxynorbornane-2:3,5:6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, etc. The dianhydride of tetracarboxylic acid. Of course, the tetracarboxylic dianhydride may be one type or two or more types may be used in combination in accordance with the characteristics of liquid crystal alignment, voltage retention characteristics, accumulated charge, etc. when forming the liquid crystal alignment film.

The method of obtaining polyamide acid by reacting the diamine of the raw material (also described as "diamine component") and the tetracarboxylic dianhydride of the raw material (also described as "tetracarboxylic dianhydride component") can be used A well-known synthesis technique. One Generally speaking, a method of reacting a diamine component and a tetracarboxylic dianhydride component in an organic solvent. The reaction of the diamine component and the tetracarboxylic dianhydride component is carried out relatively easily in an organic solvent, and it is advantageous in that no by-product is produced.

The organic solvent used in the above reaction is not particularly limited as long as it can dissolve the polyamide acid produced. In addition, even if it is an organic solvent that does not dissolve polyamic acid, it can be mixed and used in the above-mentioned solvent within a range where the polyamic acid produced does not precipitate. Furthermore, since the moisture in the organic solvent will hinder the polymerization reaction and cause the polyamide acid to be hydrolyzed, the organic solvent is preferably dehydrated and dried.

As the organic solvent, for example, 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-imidazolinone, 3-methoxy-N,N-di Methyl propionyl amine, N-methyl caprolactone, dimethyl sulfide, tetramethyl urea, pyridine, dimethyl sulfide, hexamethyl sulfide, γ-butyrolactone, isopropyl alcohol, methyl Oxymethylpentanol, dipentene, ethylpentyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl serosol, ethyl Glycerol, methyl serosol acetate, butyl serosol acetate, ethyl serosol acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene two Alcohol 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, two Propylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, two Propylene 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, pentyl 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, 3 -Methyl methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methyl Propyl oxypropionate, butyl 3-methoxypropionate, diethylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, 2-ethyl-1-hexanol, etc. These organic solvents can be used alone or in combination.

For example, when the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, a solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is directly added, or Disperse or dissolve it in an organic solvent before adding it; conversely, add a diamine component to the solution made by dispersing or dissolving the tetracarboxylic dianhydride component in an organic solvent; alternately adding the tetracarboxylic dianhydride component and For the method of the diamine component, any of these methods can be used. In addition, when the diamine component or the tetracarboxylic dianhydride component is composed of a plurality of compounds, they can be reacted in a pre-mixed state, or they can be reacted individually and sequentially, or they can be individually reacted. The reacted low-molecular-weight body undergoes a mixing reaction to become a high-molecular-weight body.

The temperature when the diamine component and the tetracarboxylic dianhydride component react The temperature can be selected at any temperature, for example, between -20 and 150°C, preferably between -5 and 100°C. In addition, the reaction system can be carried out at any concentration. For example, the total amount of the diamine component and the tetracarboxylic dianhydride component relative to the reaction liquid is 1 to 50% by mass, preferably 5 to 30% by mass.

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 desired molecular weight of the polyamide acid. As in the usual polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polyamide acid produced. The preferred range is 0.8 to 1.2.

The method of synthesizing the polyamide used in the present invention is not limited to the above method. It is the same as the general method of synthesizing polyamide acid, even if it replaces the above tetracarboxylic dianhydride and uses the corresponding structure of tetracarboxylic acid or tetracarboxylic acid. Tetracarboxylic acid derivatives such as carboxylic acid dihalides can be reacted by a known method to obtain the corresponding polyamide acid.

As a method of making the polyimide into the polyimide by directly heating the polyimide solution, and adding the catalyst to the polyimide solution as a catalyst Imidization. Moreover, the imidization rate from polyamide acid to polyimide can increase the voltage retention rate, so 30% or more is preferred, and 50-99% is more preferred. On the other hand, from the viewpoint of suppressing the whitening property, that is, suppressing the precipitation of the polymer in the varnish, 70% or less is preferable. If the characteristics of both are considered at the same time, 50~80% is better.

The temperature for thermal imidization of polyamide acid in the solution is 100~400℃, preferably 120~250℃, in order to react the imidization It is better to remove the generated water out of the system and implement it at the same time.

The catalyst imidization of polyamic acid can be carried out by adding alkaline catalyst and acid anhydride to the polyamic acid solution, and stirring at -20~250°C, preferably 0~180°C. The amount of alkaline catalyst is 0.5 to 30 mole times of the amide acid group, preferably 2 to 20 mol times, and the amount of acid anhydride is 1 to 50 mole times of the amide acid group, preferably 3 to 30 mol times. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferred because it has a moderate basicity to enable the reaction. Examples of acid anhydrides include anhydrous acetic acid, anhydrous trimellitic acid, anhydrous pyromellitic acid, etc. Among them, when anhydrous acetic acid is used, since purification after the completion of the reaction becomes easy, it is preferred. The rate of imidization of the catalyst can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

When recovering the produced polyamide acid or polyimide from the reaction solution of polyamide acid or polyimide, the reaction solution may be poured into a poor solvent to precipitate it. Examples of poor solvents used for the formation of precipitation include methanol, acetone, hexane, butyl cerosine, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, etc. . The polymer deposited in the poor solvent to precipitate can be dried under normal pressure or reduced pressure, normal temperature or heating. In addition, if the precipitation and recovery polymer is re-dissolved in the organic solvent and the re-precipitation and recovery operation is repeated 2 to 10 times, the impurities in the polymer can be reduced. As the poor solvent at this time, for example, alcohols, ketones, hydrocarbons, etc. can be cited. When three or more types of poor solvents selected from these are used, since the efficiency of purification is improved, it is preferable.

〔(B) Ingredient〕

The liquid crystal alignment agent of the present invention contains a tetracarboxylic dianhydride component selected from the group consisting of at least one tetracarboxylic dianhydride selected from the above formula (1) and (1'), and a diamine selected from the reaction The polyimide precursor and at least one polymer of the polyimine group obtained by imidizing the polyimine precursor are used as the (B) component.

When a liquid crystal alignment film using at least one tetracarboxylic dianhydride selected from the group of the above formulas (1) and (1') as a raw material is used, it is considered to be between the liquid crystal and the liquid crystal alignment film by light irradiation The interaction between them can improve the residual DC characteristics.

Examples of the tetracarboxylic dianhydride selected from the above formulas (1) and (1') include the following compounds, but they are not limited to these.

At least one tetracarboxylic dianhydride selected from the group of the above formulas (1-1) to (1-5) is used in the synthesis of polyamide acid, that is, the tetracarboxylic dianhydride component used in component (B) 10~100% is better. It is better to use 10~60%. Since it can increase the voltage retention rate, it is more preferably 10-40 mole% of the total tetracarboxylic dianhydride used in the synthesis of component (B) Next, use at least one tetracarboxylic dianhydride selected from the group consisting of formula (1-1), formula (1-3), and formula (1-5), and more preferably use 20-40 mole%.

Moreover, in the range which does not impair the effect of this invention, you may use other tetracarboxylic dianhydride mentioned in (A) component as a raw material of (B) component. For example, the tetracarboxylic dianhydride with aliphatic group or alicyclic group is used in the synthesis of polyamide acid, that is, the tetracarboxylic dianhydride component used in component (B) in an amount of 0-90 mol% good.

In addition, the polymer of the component (B) may use at least one diamine selected from the group consisting of the following formulas (B-1) to (B-5) as a raw material.

(式中，Y₁表示二級胺、三級胺，或聚有雜環構造之一價之有機基，Y₂表示二級胺、三級胺，或具有雜環構造之二價之有機基。)

(In the formula, Y ₁ represents a secondary amine, tertiary amine, or a monovalent organic group with a heterocyclic structure, and Y ₂ represents a secondary amine, tertiary amine, or a divalent organic group with a heterocyclic structure .)

By using at least one diamine selected from the above formulas (B-1) to (B-5) with a high polarity specific structure, or more separately using a diamine having a carboxyl group and a diamine having a nitrogen-containing aromatic heterocycle One or more of them can improve the residual DC characteristics due to the formation of salt or hydrogen bonding, which promotes the movement of charges through electrostatic interaction.

At least one diamine selected from the group of the above formulas (B-1) to (B-5) includes the following diamines, but they are not limited to these.

In addition, the polymer of the component (B) can also use the diamine used in the component (A) with a side chain that aligns the liquid crystal vertically, or other diamines described in the item of the component (A) above. .

At least one diamine selected from the group of the above formulas (B-1)~(B-5) to use the synthetic polyamide acid, that is, the amount of 10 to 80 mole% of the diamine component used in the component (B) Preferably, it is better to use 20~70 mole%. Since it can increase the voltage retention rate, among the diamines exemplified above, it is more preferable to use 3,5-diamines in an amount of 20 to 70 mole% of the total diamine component used in the synthesis of component (B) At least one diamine component of the group consisting of benzoic acid and 3,5-diamino-N-(pyridin-3-ylmethyl)benzamide is preferred.

In the method of manufacturing component (B), tetracarboxylic acid containing at least one tetracarboxylic dianhydride selected from the group of the above formulas (1) and (1'), and even other tetracarboxylic dianhydrides as necessary The dianhydride component, and the diamine component The reaction can obtain the polyimide precursor or polyimide.

The method for producing component (B) is the same as the method for producing component (A), except that at least one tetracarboxylic dianhydride selected from the group of formulas (1) and (1') is used as a raw material "the same.

〔Liquid crystal alignment agent〕

The liquid crystal alignment agent of the present invention is as described above, which has: a polyimide precursor selected from the group consisting of a polyimide precursor having a side chain that aligns the liquid crystal vertically, and the polyimide compound of the polyimide precursor At least one polymer grouped by imines, namely component (A), and a tetracarboxylic dianhydride component selected from the group consisting of at least one tetracarboxylic dianhydride selected from the group consisting of the above formulas (1) and (1') The polyimide precursor of the reaction product with the diamine, and at least one polymer of the polyimide of the polyimide precursor of the polyimide precursor, namely the (B) component, and an organic solvent By.

The total content of the (A) component and (B) component in the liquid crystal alignment agent of the present invention is not particularly limited, and is preferably 1-20% by mass, preferably 3-15% by mass, and particularly preferably 3-10% by mass %.

In addition, the content ratio of (A) component and (B) component is not particularly limited. For example, in mass ratio, (A) component: (B) component = X: 10-X (X = 1 to 9), which is more The best is 2:8~8:2. However, the component (B) can be the same polymer as the component (A) by having a side chain for vertically aligning the liquid crystal.

Moreover, the liquid crystal alignment agent of this invention may contain other polymers other than (A) component and (B) component. At this time, the total composition of the polymer The content of other polymers is preferably 0.5-15% by mass, preferably 1-10% by mass.

When considering the strength of the liquid crystal alignment film obtained by coating the liquid crystal alignment agent, the workability of the coating film formation, the uniformity of the coating film, etc., the molecular weight of the polymer of the liquid crystal alignment agent is determined by GPC (Gel Permeation Chromatography) The weight average molecular weight measured by the) method is preferably 5,000-1,000,000, preferably 10,000-150,000.

The organic solvent contained in the liquid crystal alignment agent is not particularly limited, as long as it can dissolve or disperse the components such as (A) component and (B) component. For example, the organic solvents exemplified in the synthesis of the above-mentioned polyamide acid can be cited. From the standpoint of solubility, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone , 3-Methoxy-N,N-dimethylpropanamide etc. are preferred. In particular, N-methyl-2-pyrrolidone or N-ethyl-2-pyrrolidone is preferable, but a mixed solvent of two or more types can also be used.

In addition, it is better to mix a solvent that improves the uniformity or smoothness of the coating film with an organic solvent that has high solubility for the components contained in the liquid crystal alignment agent.

As a solvent for improving the uniformity or smoothness of the coating film, for example, isopropyl alcohol, methoxymethylpentanol, methyl serosol, ethyl serosol, butyl serosol, methyl Gyrosteol acetate, butyl serosol acetate, ethyl serosol acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol , Ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene Alcohol 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 mono Ethyl 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, pentyl 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, ethyl acetate, n-butyl acetate , Propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl ester, 3-methoxypropionic acid butyl ester, 1-methoxy-2-propanol, 1-ethyl Oxy-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, methyl lactate, ethyl lactate, lactic acid n -Propyl ester, n-butyl lactate, isoamyl lactate, 2-ethyl-1-hexanol, etc. Multiple types of these solvent systems can also be mixed. When using these solvents, 5 to 80% by mass of the total solvent contained in the liquid crystal alignment agent is preferable, and preferably 20 to 60% by mass.

The liquid crystal alignment agent may contain components other than the above. As an example, there can be mentioned, for example, improving the uniformity of the film thickness when the liquid crystal alignment agent is applied or Compounds for surface smoothness, compounds for improving the adhesion between the liquid crystal alignment film and the substrate, compounds for improving the film strength of the liquid crystal alignment film, etc.

As the compound that improves the uniformity or surface smoothness of the film thickness, for example, a fluorine-based surfactant, a silicone-based surfactant, a non-ionic surfactant, etc. can be mentioned. More specifically, for example, Eftop EF301, EF303, EF352 (manufactured by Tohkem Products), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Corporation), Fluorad FC430, FC431 (manufactured by Sumitomo 3M), Asahiguard AG710 , Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Company), etc. When using these surfactants, the use ratio is preferably 0.01-2 parts by mass, preferably 0.01-1 parts by mass, relative to 100 parts by mass of the total polymer contained in the liquid crystal alignment agent.

As a specific example of the compound that improves the adhesion between the liquid crystal alignment film and the substrate, for example, a functional silane-containing compound or an epoxy group-containing compound can be cited. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane , N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3- Ureaylpropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-amino Propyl triethoxysilane, N-triethoxysilylpropyl triethylenetriamine, N-trimethoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4 ,7-Triazadecane, 10-Triethoxysilyl-1,4,7-Triaza Decane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl -3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl- 3-Aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane , Ethylene Glycol Diglycidyl Ether, Polyethylene Glycol Diglycidyl Ether, Propylene Glycol Diglycidyl Ether, Tripropylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl Ether, Neopentyl Glycol Diglycidyl Ether, 1,6-Hexanediol Diglycidyl Ether, Glycerol Diglycidyl Ether, 2,2-Dibromoneopentyl Glycol Diglycidyl Ether, 1,3,5,6-tetraepoxypropyl-2,4-hexanediol, N,N,N',N'-tetraepoxypropyl-m-diamine, 1,3-bis( N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraepoxypropyl-4, 4'-diaminodiphenylmethane, 3-( N-allyl-N-glycidyl)aminopropyl trimethoxysilane, 3-(N,N-diglycidyl)aminopropyl trimethoxysilane, etc.

In addition, in order to further improve the film strength of the liquid crystal alignment film, 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, tetra(methoxymethyl)bisphenol, etc. The phenolic compound. When using these compounds, relative to 100 parts by mass of the total polymer contained in the liquid crystal alignment agent, preferably 0.1-30 parts by mass, preferably 1-20 parts by mass.

Moreover, as long as the scope of effects of the present invention is not impaired, in addition to the above, a dielectric or conductive material for the purpose of changing the electrical properties of the liquid crystal alignment film such as the dielectric rate or conductivity can be added to the liquid crystal alignment agent. .

By coating the liquid crystal alignment agent on the substrate and firing it, a liquid crystal alignment film that aligns the liquid crystal vertically can be formed.

The liquid crystal alignment agent of the present invention contains: selected from polyimide precursors having side chains for vertical alignment of liquid crystals, and polyimide obtained by imidizing the polyimide precursors At least one polymer of the group is the (A) component, and is selected from the group consisting of at least one tetracarboxylic dianhydride component selected from the group consisting of the above formula (1) and (1') and two The polyimide precursor obtained by the reaction of amine, and at least one polymer of the polyimide obtained by imidizing the polyimide precursor, namely component (B), can Makes the residual DC characteristics good.

The substrate is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as glass substrates, acrylic substrates, or polycarbonate substrates can be used. In addition, from the viewpoint of simplification of the manufacturing process, it is better to use a substrate on which ITO electrodes for driving liquid crystals are formed. In addition, in a reflective liquid crystal display element, if only a single-sided substrate is used, opaque objects such as silicon wafers can also be used. In this case, the electrodes can also use light-reflecting materials such as aluminum.

The coating method of the liquid crystal alignment agent is not particularly limited. Examples include methods using screen printing, offset printing, flexographic printing, inkjet printing, etc., or dipping, roll coating, slit coating, and rotation. Coating method, etc.

The firing temperature of the coating film formed by applying the liquid crystal alignment agent is not limited. For example, it can be implemented at any temperature from 100 to 350°C, preferably 120 to 300°C, more preferably 150 to 250°C. This firing system can add Hot plate, hot air circulation furnace, infrared furnace, etc.

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

The liquid crystal display element of the present invention is provided with two substrates having opposing arrangements, a liquid crystal layer disposed between the substrates, and a liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention disposed between the substrate and the liquid crystal layer The liquid crystal display element of the vertical alignment mode of the liquid crystal cell. Specifically, it is a liquid crystal display element of a vertical alignment method equipped with a liquid crystal cell, and the liquid crystal cell is formed by coating the liquid crystal alignment agent of the present invention on two substrates and firing the liquid crystal alignment film, so that The liquid crystal alignment film is fabricated by arranging two substrates facing each other, sandwiching a liquid crystal layer composed of liquid crystal between the two substrates and irradiating ultraviolet rays.

Therefore, it is believed that by using the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention and irradiating the liquid crystal alignment film and the liquid crystal layer with ultraviolet rays, the interaction between the liquid crystal and the liquid crystal alignment film of the present invention can become liquid crystal residue. DC is a small liquid crystal display element that is not easy to produce burn-in.

The substrate used for the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, and is usually a substrate on which transparent electrodes for driving liquid crystals have been formed. As a specific example, the same thing as the substrate described in the said liquid crystal alignment film is mentioned.

The liquid crystal display element of the present invention can also be used with the conventional electrode pattern or protrusion pattern substrate, but by having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention, even if it is formed on a single-sided substrate 10μm line/slit electrode pattern, no slit pattern is formed on the opposite substrate The substrate with the structure of the pattern or protrusion pattern can still be operated, so the manufacturing process of the device can be simplified, and high transmittance can be achieved.

In addition, a high-performance device such as a TFT-type device uses a device in which a transistor is formed between the electrode for driving liquid crystal and the substrate.

In the case of a transmissive liquid crystal display element, the above-mentioned substrate is generally used, but in a reflective liquid crystal display element, if only a single-sided substrate is used, an opaque substrate such as a silicon wafer can also be used. At this time, the electrode system formed on the substrate can also use a material that reflects light, such as aluminum.

The liquid crystal alignment film is formed by coating the liquid crystal alignment agent of the present invention on the substrate and then firing, 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 crystals having negative dielectric anisotropy can be used. For example, dicyanobenzene-based liquid crystal, azine-based liquid crystal, Schiff base-based liquid crystal, oxyazo-based liquid crystal, biphenyl-based liquid crystal, phenylcyclohexane-based liquid crystal, terphenyl-based liquid crystal, etc. can be used . Furthermore, it is preferable to use the alkenyl-based liquid crystal in combination. As such an alkenyl-based liquid crystal, conventionally known ones can be used. For example, the compound etc. which are represented by the following formula are mentioned, but it is not limited to this.

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, liquid crystal compositions with negative dielectric anisotropy manufactured by Merck, namely MLC-6608, MLC-6609, etc. can be used. In addition, liquid crystal compositions containing alkenyl-based liquid crystals and having negative dielectric anisotropy, namely MLC-3022 and MLC-3023 (including photopolymerizable compounds (RM)) manufactured by Merck, etc. can be used.

As a method of sandwiching this liquid crystal layer between two substrates, a known method can be cited. For example, preparing a pair of substrates that have formed a liquid crystal alignment film, spreading spacers such as beads on the liquid crystal alignment film of one substrate, and coating the adhesive around the substrate to make the surface on the side where the liquid crystal alignment film is formed A method of bonding to another substrate toward the inside, injecting liquid crystal under reduced pressure and sealing.

Also, prepare a pair of substrates that have formed a liquid crystal alignment film, spread spacers such as beads on the liquid crystal alignment film of one substrate, and then drop the liquid crystal, and then place the liquid crystal alignment film on the side facing the inner side and attach it to the other substrate. One substrate and the method of sealing can also manufacture liquid crystal cells. The thickness of the spacer at this time The degree is preferably 1 to 30 μm, 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 can 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. If the amount of ultraviolet irradiation is small, it is possible to suppress a decrease in reliability due to damage to the members constituting the liquid crystal display element.

The ultraviolet wavelength used is preferably 300~500nm, preferably 300~400nm.

In addition, the ultraviolet irradiation of the liquid crystal alignment film and the liquid crystal layer can also be carried out in a state where a voltage is applied and the electric field is maintained. Here, as the voltage applied between the electrodes, for example, 5-30Vp-p, preferably 5-20Vp-p.

In the case of the PSA method with a polymerizable compound in the liquid crystal, if a voltage is applied to the liquid crystal alignment film and the liquid crystal layer and ultraviolet rays are simultaneously irradiated, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules are tilted by the polymer By receiving memory, the response speed of the obtained liquid crystal display element can be increased. In addition, by containing the component (B), the residual DC characteristics also become good. At this time, if the amount of ultraviolet irradiation is small, the ultraviolet irradiation time can be reduced, and the manufacturing efficiency is improved, so it is more suitable.

In addition, the above-mentioned liquid crystal alignment agent can not only be useful as a liquid crystal alignment agent for the production of PSA-type liquid crystal displays or SC-PVA-type liquid crystal displays and other vertical alignment methods of liquid crystal display elements, but also can be suitably used for manufacturing by rubbing or photo Liquid crystal alignment film formed by processing.

[Example]

The following examples illustrate the present invention in more detail, but the present invention is not limited by these. 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-cyclobutane tetracarboxylic 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)benzylamide

DDM: 4,4'-Diaminodiphenylmethane

(式DA-6中，t表示反式。)

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

<Solvent>

NMP: N-methyl-2-pyrrolidone.

BCS: Butyl Serosu.

<Polyimine molecular weight measurement>

Device: Normal Temperature Gel Permeation Chromatography (GPC) device (SSC-7200) manufactured by Quanzhou Science Company, column: column (KD-803, KD-805) manufactured by Shodex Company, column temperature: 50℃, elution Liquid: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr‧H ₂ O) is 30mmol/L, phosphoric acid‧anhydrous crystal (o-phosphoric acid) is 30mmol/L, tetrahydrofuran (THF) ) Is 10ml/L), flow rate: 1.0ml/min, calibration line preparation standard sample: Tosoh Corporation’s TSK standard polyethylene oxide (molecular weight approximately 9000,000, 150,000, 100,000, and 30,000), and , Polyethylene glycol (molecular weight of about 12,000, 4,000, and 1,000) made by Polymer Laboratories.

<Measurement of imidization rate>

5)，添加氘化二甲亞碸(DMSO-d₆、0.05質量%TMS混合品)1.0ml，施加超音波使其完全溶解。在NMR測量裝置(日本電子資料公司製之JNW-ECA500)中測量此溶液之500MHz之質子NMR。醯亞胺化率係以源自醯亞胺化前後未變化之構造之質子決定當作基準質子，使用此質子之波峰累算值，與源自出現於9.5~10.0ppm附近之醯胺酸之NH基之質子波峰累算值，藉由以下之式所求得者。尚且，下述式中，x為源自醯胺酸之NH基之質子波峰累算值、y為基準質子之波峰累算值、α為基準質子之對聚醯胺酸(醯亞胺化率為0%)時之醯胺酸之NH基之質子1個的個數比例。 Put 20 mg of polyimide powder into the NMR sample tube (standard for NMR sample tube manufactured by Kusano Scientific

5) Add 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% by mass TMS mixture), and apply ultrasonic waves to completely dissolve it. The 500 MHz proton NMR of this solution was measured in an NMR measuring device (JNW-ECA500 manufactured by JEOL Ltd.). The rate of imidization is determined by the proton derived from the unchanged structure before and after imidization as the reference proton. Using the peak cumulative value of this proton, and the ratio derived from the imidic acid appearing near 9.5~10.0ppm The cumulative value of the proton peak of the NH group is obtained by the following formula. Furthermore, in the following formula, x is the cumulative value of the proton peak derived from the NH group of amide acid, y is the cumulative value of the peak of the reference proton, and α is the cumulative value of the peak of the reference proton to polyamide acid (imidization rate 0%) The ratio of the number of protons of the NH group of the amide acid.

The imidization rate (%)=(1-α‧x/y)×100

<Synthesis Example 1>

Dissolve BODA (3.30g, 13.2mmol), DA-3 (3.35g, 8.80mmol), and m-PDA (1.43g, 13.2mmol) in NMP (29.8g), and react at 60°C for 4 hours . Then, PMDA (1.85 g, 8.47 mmol) and NMP (9.93 g) were added, and it was made to react at room temperature for 4 hours, and the polyamide acid solution X1 was obtained. The polyamide acid has a number average molecular weight of 13,000 and a weight average molecular weight of 39,000.

After adding NMP to this polyamic acid solution (25g) and diluting to 6.5% by mass, anhydrous acetic acid (5.62g) and pyridine (4.35g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (300 g), and the precipitate obtained was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder A. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

NMP (18.0 g) was added to the obtained polyimide powder A (2.0 g), and the mixture was stirred at 70°C for 12 hours to be dissolved. BCS (13.3 g) was added to this solution, and the liquid crystal alignment agent A1 was obtained by stirring at room temperature for 2 hours.

<Synthesis Example 2>

Dissolve BODA (3.30g, 13.2mmol), DA-3 (3.35g, 8.80mmol), and m-PDA (1.43g, 13.2mmol) in NMP (29.2g), and react at 60°C for 4 hours . Then, CBDA (1.66g, 8.47mmol) and NMP (9.74g) were added, and the temperature was kept at 40°C The reaction was carried out for 4 hours to obtain a polyamide acid solution.

Except that this polyimide solution (25 g) was used, the other system was carried out in the same manner as in Synthesis Example 1, and the imidization reaction was performed, and the post-reaction treatment was performed to obtain polyimide powder B. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder B (2.0 g) was used instead of the polyimide powder A, the other treatments were performed in the same manner as in Synthesis Example 1 to obtain the liquid crystal alignment agent U1.

Next, BODA (3.75g, 15mmol), DA-3 (1.90g, 4.99mmol), m-PDA (2.16g, 20.0mmol) were dissolved in NMP (29.7g), and reacted at 60°C for 4 hours Then, PMDA (2.10 g, 9.63 mmol) and NMP (9.92 g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamic acid solution was obtained.

Except that this polyimide solution (25 g) was used, the other system was carried out in the same manner as in Synthesis Example 1, and the imidization reaction was performed, and the post-reaction treatment was performed to obtain polyimide powder C. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder C (2.0 g) was used instead of the polyimide powder A, the same treatment as in Synthesis Example 1 was performed to obtain the liquid crystal alignment agent L1.

Take 5.0g of the obtained liquid crystal alignment agent U1 as the first component and 5.0g of the liquid crystal alignment agent L1 as the second component and mix them to obtain the liquid crystal alignment 剂A2.

<Synthesis Example 3>

Dissolve BODA (22.5g, 90.0mmol), DA-4 (62.1g, 158mmol), p-PDA (14.6g, 135mmol), and 3AMPDA (38.16, 157mmol) in NMP (620g) at 55°C. After reacting for 2 hours, CBDA (68.4 g, 349 mmol) and NMP (102 g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamide acid solution was obtained.

After adding NMP to this polyamic acid solution (85g) and diluting to 6.5% by mass, anhydrous acetic acid (18.87g) and pyridine (5.85g) were added as an imidization catalyst, and it was made to react at 50 degreeC for 3 hours. This reaction solution was poured into methanol (1000 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder D. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder D (2.0 g) was used instead of the polyimide powder A, the same treatment as in Synthesis Example 1 was performed to obtain the liquid crystal alignment agent U2.

Next, BODA (123g, 491mmol), DBA (127g, 837mmol), DA-1 (60.7g, 148mmol) were dissolved in NMP (1246g), and after reacting at 55°C for 2 hours, PMDA (43.0g , 197mmol) and NMP (172g), let it react at room temperature for 4 hours, then add CBDA (50.6g, 258mmol) and NMP (202g), it was made to react at room temperature for 4 hours, and the polyamic acid solution was obtained.

After adding NMP to this polyamic acid solution (700g) and diluting to 8 mass %, anhydrous acetic acid (172g) and pyridine (54g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (7000 g), and the precipitate obtained was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder E. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder E (2.0 g) was used instead of the polyimide powder A, the same treatment as in Synthesis Example 1 was performed to obtain the liquid crystal alignment agent L2.

The obtained 5.0 g of the liquid crystal alignment agent U2 was used as the first component, and 5.0 g of the liquid crystal alignment agent L2 was used as the second component and mixed to obtain the liquid crystal alignment agent A3.

<Synthesis Example 4>

Dissolve BODA (1.80g, 7.19mmol), DA-3 (2.74g, 7.20mmol), 3AMPDA (0.87g, 3.59mmol), and DA-2 (2.38g, 7.20mmol) in NMP (29.7g), The reaction was carried out at 60°C for 4 hours. Then, CBDA (2.10g, 10.7mmol) and NMP (9.89g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamic acid solution was obtained.

Add NMP to this polyamide acid solution (25g) and dilute to 6.5 mass After %, anhydrous acetic acid (4.64g) and pyridine (3.59g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (300 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder F. The polyimide has an imidization rate of 74%, a number average molecular weight of 12,500, and a weight average molecular weight of 38,000.

Except that the obtained polyimide powder F (2.0 g) was used instead of the polyimide powder A, the same treatment as in Synthesis Example 1 was performed to obtain the liquid crystal alignment agent U3.

Next, BODA (3.15g, 12.6mmol), DA-3 (2.40g, 6.31mmol), DBA (1.28g, 8.40mmol) and 3AMPDA (1.25g, 6.31mmol) were dissolved in NMP (30.4g), The reaction was carried out at 60°C for 4 hours. Then, PMDA (1.79 g, 8.19 mmol) and NMP (10.14 g) were added, and it was made to react at room temperature for 4 hours, and the polyamide acid solution was obtained.

After adding NMP to this polyamic acid solution (25g) and diluting to 6.5% by mass, anhydrous acetic acid (5.26g) and pyridine (4.08g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (300 g), and the precipitate obtained was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder G. The polyimide has an imidization rate of 75%, a number average molecular weight of 13,000, and a weight average molecular weight of 38,500.

Except that instead of polyimide powder A, the obtained polyimide powder G (2.0g) was used, and the other systems were treated in the same manner as in Synthesis Example 1. Obtain liquid crystal alignment agent L3.

The obtained 5.0 g of the liquid crystal alignment agent U3 was used as the first component, and 5.0 g of the liquid crystal alignment agent L3 was used as the second component and mixed to obtain a liquid crystal alignment 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), and reacted at 60°C for 4 hours. Then, CBDA (1.89 g, 9.64 mmol) and NMP (9.71 g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamide acid solution was obtained.

Except for using this polyimide solution (25 g), the other systems were carried out in the same manner as in Synthesis Example 1, and the imidization reaction was performed, and the post-reaction treatment was performed to obtain polyimide powder H. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder H (2.0 g) was used instead of the polyimide powder A, the same treatment as in Synthesis Example 1 was performed to obtain the liquid crystal alignment agent L4.

The 5.0 g of the liquid crystal alignment agent U1 obtained in Synthesis Example 2 was used as the first component, and 5.0 g of the liquid crystal alignment agent L4 was used as the second component and mixed to obtain a liquid crystal alignment 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), and reacted at 80°C for 5 hours. Then, CBDA (1.01 g, 5.15 mmol) and NMP (8.30 g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamide acid solution was obtained.

After adding NMP to this polyamic acid solution (38g) and diluting to 6 mass %, anhydrous acetic acid (8.43g) and pyridine (3.27g) were added as an imidization catalyst, and it was made to react at 100 degreeC for 3 hours. This reaction solution was poured into methanol (484 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder I. The imidization rate of this polyimide is 73%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,000.

Except that the obtained polyimide powder I (2.0 g) was used instead of the polyimide powder A, the other systems were processed in the same manner as in Synthesis Example 1 to obtain a liquid crystal alignment agent A6.

<Synthesis Example 7>

NMP (10.0g) was added to the polyamide solution X1 (10g) obtained in Synthesis Example 1, and after stirring at room temperature for 1 hour, BCS (13.3g) was added, and it was obtained by stirring at room temperature for 2 hours Liquid crystal alignment agent A7.

<Synthesis Example 8>

Make BODA (123g, 491mmol), DBA (127g, 837mmol), DA-1 (60.7g, 148mmol) was dissolved in NMP (1246g) and reacted at 55°C for 2 hours, CA-1 (70.6g, 197mmol) and NMP (282g) were added and reacted at room temperature 4 After hours, CBDA (50.6 g, 258 mmol) and NMP (202 g) were added and reacted at room temperature for 4 hours to obtain a polyamide acid solution.

After adding NMP to this polyamic acid solution (40g) and diluting to 8 mass %, anhydrous acetic acid (9.15g) and pyridine (2.84g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 3 hours. This reaction solution was poured into methanol (473 g), and the obtained precipitate was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder J. The imidization rate of this polyimide is 74%, the number average molecular weight is 13,500, and the weight average molecular weight is 40,000.

Except that the obtained polyimide powder J (2.0 g) was used instead of the polyimide powder A, the other systems were processed in the same manner as in Synthesis Example 1 to obtain a liquid crystal alignment agent L5.

The 5.0 g of the liquid crystal alignment agent U2 obtained in Synthesis Example 3 was used as the first component, and 5.0 g of the liquid crystal alignment agent L5 was used as the second component and mixed to obtain a liquid crystal alignment agent A8.

<Synthesis Example 9>

Dissolve BODA (2.38g, 9.51mmol), DBA (1.45g, 9.53mmol), DA-1 (2.34g, 5.70mmol), DA-3 (1.45g, 3.81mmol) in NMP (30.4g), After reacting at 55°C for 3 hours, CA-1 (2.04g, 5.69mmol) and NMP were added (8.17g), it was made to react at room temperature for 4 hours, CBDA (0.60g, 3.06mmol) and NMP (2.38g) were added, and it was made to react at room temperature for 4 hours, and the polyamide acid solution was obtained.

After adding NMP to this polyamic acid solution (40g) and diluting to 6.5% by mass, anhydrous acetic acid (7.46g) and pyridine (2.31g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 3 hours. This reaction solution was poured into methanol (465 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder L. The imidization rate of this polyimide is 75%, the number average molecular weight is 13,000, and the weight average molecular weight is 39,500.

Except that the obtained polyimide powder L (2.0 g) was used instead of the polyimide powder A, the other systems were processed in the same manner as in Synthesis Example 1 to obtain a liquid crystal alignment agent L6.

The 5.0 g of the liquid crystal alignment agent U2 obtained in Synthesis Example 3 was used as the first component, and 5.0 g of the liquid crystal alignment agent L6 was used as the second component and mixed to obtain a liquid crystal alignment agent A9.

<Synthesis Example 10>

Dissolve BODA (2.25g, 8.99mmol), DA-2 (2.97g, 8.99mmol), and DA-3 (3.43g, 9.01mmol) in NMP (34.6g), and react at 60°C for 4 hours . Then, CBDA (1.75 g, 8.92 mmol) and NMP (6.99 g) were added, and it was made to react at 40 degreeC for 4 hours, and the polyamide acid solution was obtained.

Add NMP to this polyamide acid solution (40g) and dilute to 6.5 mass After %, anhydrous acetic acid (7.06g) and pyridine (2.19g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (463 g), and the obtained precipitate was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder M. The imidization rate of this polyimide is 74%, the number average molecular weight is 12,500, and the weight average molecular weight is 38,500.

Except that the obtained polyimide powder M (2.0 g) was used instead of the polyimide powder A, the other systems were processed in the same manner as in Synthesis Example 1 to obtain the liquid crystal alignment agent U4.

Next, BODA (1.20g, 4.80mmol), DBA (1.46g, 9.59mmol), 3AMPDA (1.74g, 7.18mmol), and DA-3 (2.74g, 7.20mmol) were dissolved in NMP (28.58g), The reaction was carried out at 60°C for 2 hours. After that, PMDA (1.05g, 4.81mmol) and NMP (4.19g) were added and reacted at room temperature for 4 hours, then CBDA (2.78g, 14.18mmol) and NMP (11.1g) were added at room temperature The reaction was carried out for 4 hours to obtain a polyamide acid solution.

After adding NMP to this polyamic acid solution (40g) and diluting to 6.5% by mass, anhydrous acetic acid (8.90g) and pyridine (2.76g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (472 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder N. The polyimide has an imidization rate of 74%, a number average molecular weight of 13,000, and a weight average molecular weight of 39,000.

In addition to replacing polyimide powder A, use the obtained polyimide powder Except for N (2.0 g), the same treatment as in Synthesis Example 1 was performed to obtain liquid crystal alignment agent L7.

Using 3.0 g of the obtained liquid crystal alignment agent U4 as the first component and 7.0 g of the liquid crystal alignment agent L7 as the second component and mixing them to obtain a liquid crystal alignment agent A10.

<Synthesis Example 11>

Dissolve BODA (1.20g, 4.80mmol), DBA (1.46g, 9.59mmol), 3AMPDA (1.74g, 7.18mmol), and DA-3 (2.74g, 7.20mmol) in NMP (28.58g) at 60 It was allowed to react at °C for 2 hours. After that, CA-2 (1.41g, 4.79mmol) and NMP (5.65g) were added, and allowed to react at room temperature for 4 hours. Then CBDA (2.78g, 14.18mmol) and NMP (11.1g) were added to the room. The reaction was carried out at low temperature for 4 hours to obtain a polyamide acid solution.

After adding NMP to this polyamic acid solution (40g) and diluting to 6.5% by mass, anhydrous acetic acid (8.61g) and pyridine (2.67g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 4 hours. This reaction solution was poured into methanol (470 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder O. The polyimide has an imidization rate of 75%, a number average molecular weight of 14,000, and a weight average molecular weight of 39,000.

Except that the obtained polyimide powder O (2.0 g) was used instead of the polyimide powder A, the other systems were treated in the same manner as in Synthesis Example 1 to obtain a liquid crystal alignment agent L8.

3.0 g of the liquid crystal alignment agent U4 obtained in Synthesis Example 10 was used as the first component, and 7.0 g of the liquid crystal alignment agent L8 was used as the second component and mixed to obtain a liquid crystal alignment agent A11.

<Synthesis Example 12>

Make CA-3 (2.42g, 10.8mmol), DA-6 (2.40g, 9.01mmol), DA-5 (1.56g, 3.59mmol), and DA-7 (2.67g, 5.40mmol) dissolved in NMP (31.7 In g), the reaction was carried out at 60°C for 4 hours. Then, PMDA (1.30 g, 5.94 mmol) and NMP (5.20 g) were added, and it was made to react at room temperature for 4 hours, and the polyamide acid solution was obtained.

After adding NMP to this polyamic acid solution (40g) and diluting to 6.0 mass %, anhydrous acetic acid (2.01g) and pyridine (1.61g) were added as an imidization catalyst, and it was made to react at 110 degreeC for 4 hours. This reaction solution was poured into methanol (480 g), and the precipitate obtained was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder P. The imidization rate of this polyimide is 55%, the number average molecular weight is 11,000, and the weight average molecular weight is 32,000.

Instead of polyimide powder A, NMP (18.0 g) was added to the obtained polyimide powder P (2.0 g), and the mixture was stirred at 70°C for 12 hours to dissolve it. BCS (13.3 g) was added to this solution, and the liquid crystal alignment agent A12 was obtained by stirring at room temperature for 2 hours.

<Synthesis Example 13>

Make CA-3 (3.83g, 17.1mmol), DA-6 (2.40g, 9.01mmol), DA-5 (1.56 g, 3.59 mmol) and DA-7 (2.67 g, 5.40 mmol) were dissolved in NMP (31.7 g) and reacted at 60°C for 6 hours to obtain a polyamide acid solution.

After adding NMP to this polyamic acid solution (40g) and diluting to 6.0 mass %, anhydrous acetic acid (2.07g) and pyridine (1.60g) were added as an imidization catalyst, and it was made to react at 110 degreeC for 4 hours. This reaction solution was poured into methanol (480 g), and the precipitate obtained was separated by filtration. This deposit was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder Q. The imidization rate of this polyimide is 55%, the number average molecular weight is 10,500, and the weight average molecular weight is 31,500.

NMP (18.0g) was added to the obtained polyimide powder Q (2.0g), and it stirred at 70 degreeC for 12 hours, and was made to melt|dissolve. BCS (13.3 g) was added to this solution, and the liquid crystal alignment agent U5 was obtained by stirring at room temperature for 2 hours.

Next, CA-3 (2.96g, 13.2mmol), DDM (3.49g, 17.6mmol), and DA-7 (2.18g, 4.41mmol) were dissolved in NMP (34.5g) and reacted at 60°C 4 hours. Then, PMDA (1.54 g, 7.04 mmol) and NMP (6.10 g) were added, and it was made to react at room temperature for 4 hours, and the polyamide acid solution X2 was obtained. The polyamide acid has a number average molecular weight of 12,500 and a weight average molecular weight of 34,000.

Add NMP (10.0g) to the obtained polyamide acid solution X2 (10g), stir at room temperature for 1 hour, add BCS (13.3g), and stir at room temperature for 2 hours to obtain liquid crystal alignment agent L9 .

The obtained 5.0 g of the liquid crystal alignment agent U5 was used as the first component, and 5.0 g of the liquid crystal alignment agent L9 was used as the second component and mixed to obtain a liquid crystal alignment agent A13.

<Making a liquid crystal cell>

(Example A)

Using the liquid crystal alignment agent A1 obtained in Synthesis Example 1, a liquid crystal cell was produced by the following operation sequence. The liquid crystal alignment agent A1 obtained in Synthesis Example 1 was spin-coated on the ITO surface of the ITO electrode substrate with a pixel size of 100μm×300μm and an ITO electrode pattern with a line/space of 5μm, respectively, and heated at 80°C After the board was dried for 90 seconds, it was fired in a hot air circulating oven at 200°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm.

In addition, the liquid crystal alignment agent A1 was spin-coated on the ITO surface where the electrode pattern was not formed, dried on a hot plate at 80°C for 90 seconds, and fired in a hot air circulating oven at 200°C for 20 minutes to form a film. 100nm thick liquid crystal alignment film.

Regarding the above two substrates, a 4 μm bead spacer was spread on the liquid crystal alignment film of one substrate, and then a sealant (solvent type thermosetting epoxy resin) was printed from above. Next, the surface of the other substrate on the side where the liquid crystal alignment film is formed faces the inner side and is bonded to the previous substrate, and then the sealant is cured to form an empty cell. Liquid crystal MLC-6608 (trade name, manufactured by Merck & Co.), which is a liquid crystal composition that does not contain alkenyl-based liquid crystal, is injected into the empty cell by a reduced pressure injection method to prepare a liquid crystal cell. Make the obtained liquid crystal cell at 110 Annealing (realignment treatment) is carried out in a circulating oven at ℃ for 30 minutes.

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. Furthermore, for comparison, under the same conditions, the voltage retention and residual DC were also measured on the liquid crystal cells that were not irradiated with light.

〔Light exposure〕

From the outside of the liquid crystal cell, irradiate 6J/cm ² of UV that passes through a 365nm bandpass filter (the lamp uses USHIO Super High Pressure Mercury Lamp LL, and is carried out by ORC UV Light Measure Model UV-M03A (accessory: UV-35) Measure illuminance).

〔Voltage retention ratio〕

Using VHR-1A manufactured by Toyo Technology Co., Ltd., at a temperature of 60°C, a voltage of 1V was applied to the obtained liquid crystal cell for 60μs, and the ratio of the voltage held after 1667ms was measured as the voltage retention rate.

[Evaluation of Residual DC]

An AC voltage of 5.8Vpp and a DC voltage of 1V were applied to the liquid crystal cell after the voltage retention rate was measured for 48 hours, and immediately after the DC voltage was released, the voltage (residual DC) generated in the liquid crystal cell was obtained by the flicker elimination method. This value is an indicator of the afterimage characteristics, and when this value is below ±30mV, it can be said that the afterimage characteristics are excellent.

(Example B, Comparative Example A, Reference Example A)

Except that the liquid crystal alignment agent described in Table 2 was used instead of the liquid crystal alignment agent A1, the other operations were the same as in Example A to produce light-irradiated liquid crystal cells, and the voltage retention and residual DC were measured.

(Example 1)

Except that instead of MLC-6608, MLC-3022 (trade name of Merck & Co.) was used as a liquid crystal composition containing alkenyl-based liquid crystals, the same operation as in Example A was performed to produce light-irradiated liquid crystal cells, and Measure voltage retention and residual DC.

(Examples 2~4, 8~14)

Except that the liquid crystal alignment agent described in Table 3 was used instead of the liquid crystal alignment agent A1, the same operation as in Example 1 was performed to manufacture a light-irradiated liquid crystal cell, and the voltage retention and residual DC were measured.

(Comparative example 1~2)

Except that the liquid crystal alignment agent described in Table 3 was used instead of the liquid crystal alignment agent A1, the same operation as in Example 1 was performed to manufacture a light-irradiated liquid crystal cell, and the voltage retention and residual DC were measured.

(Example 5)

In addition to replacing MLC-6608, it uses a liquid crystal composition containing alkenyl liquid crystal and RM (photopolymerizable compound), namely MLC-3023 (Merck Company trade name), and replace the liquid crystal aligning agent A1 with the liquid crystal aligning agent A2, and the PSA treatment is carried out under the following conditions without light irradiation, the others are manufactured by the same operation as in Example A. , And measure the voltage retention and residual DC.

〔PSA treatment〕

Under the condition of applying 15V DC voltage, from the outside of the liquid crystal cell, irradiate 10J/cm ² of UV passing through a 325nm high-pass filter (the lamp uses USHIO Super High Pressure Mercury Lamp LL, with ORC UV Light Measure Model UV- M03A (Accessory: UV-35) for measuring illuminance). Thereafter, in a state where no voltage was applied, a UV-FL irradiation device manufactured by Toshiba Lighting Technology Co., Ltd. was used to irradiate UV (UV lamp: FLR40SUV32/A-1) for 30 minutes.

(Examples 15-19)

Except that the liquid crystal alignment agent described in Table 4 was used instead of the liquid crystal alignment agent A2, the other operations were performed in the same manner as in Example 5 to produce a PSA-treated liquid crystal cell, and the voltage retention and residual DC were measured.

(Comparative Examples 3~4)

Except that the liquid crystal alignment agent described in Table 4 was used instead of the liquid crystal alignment agent A2, the other operations were performed in the same manner as in Example 5 to produce a PSA-treated liquid crystal cell, and the voltage retention and residual DC were measured.

(Example 6)

Except for replacing MLC-6608 with a liquid crystal composition containing alkenyl-based liquid crystals, namely MLC-3022 (Merck's trade name), and replacing liquid crystal alignment agent A1 with liquid crystal alignment agent A2, other systems are the same as in Example A The same operation was performed to manufacture a light-irradiated liquid crystal cell, and the liquid crystal cell was annealed in a circulating oven at 150° C. for 3 hours, and then the voltage retention and residual DC were measured.

(Example 7)

Except for replacing MLC-6608 with a liquid crystal composition containing alkenyl-based liquid crystals, namely MLC-3022 (Merck's trade name), and replacing liquid crystal alignment agent A1 with liquid crystal alignment agent A2, other systems are the same as in Example A The same operation was performed to manufacture a light-irradiated liquid crystal cell, and the liquid crystal cell was annealed in a circulating oven at 150°C for 3 hours, and light-irradiated again under the same conditions, and then the voltage retention and residual DC were measured.

Table 2 shows the results of using MLC-6608, a conventional liquid crystal that does not contain alkenyl-based liquid crystal, as Examples A, B, Comparative Example A, and Reference Example A. In Comparative Example A and Reference Example A that did not use a polymer having structural units derived from PMDA, the residual DC was reduced in the past. The method used in Reference Example A using highly polar diamine, the accumulation of residual DC was suppressed.

On the other hand, even in Example A and Example B using a polymer having a structural unit derived from PMDA, although there is a difference in the degree of introduction of the structural unit derived from PMDA, compared with Comparative Example A, residual The DC is reduced, and it can be found to be more reduced by light irradiation.

Therefore, in the liquid crystal composition that does not contain alkenyl-based liquid crystal, that is, MLC-6608, the reduction in the cumulative amount of residual DC by the past method can be achieved, even if it is a liquid crystal containing a polymer having a structural unit derived from PMDA The alignment film can still reduce the accumulation of residual DC by light irradiation.

Table 3 shows the results of using MLC-3022, a liquid crystal composition containing alkenyl-based liquid crystal. Compared with Table 2, it can be seen that the overall voltage retention rate is reduced. Moreover, in Comparative Example 1 and Comparative Example 2, even in Comparative Example 2 in which MLC-6608 was used and the liquid crystal alignment agent A6 having an effect on residual DC was used, the cumulative amount of residual DC was large regardless of light irradiation. On the other hand, in Example 1, Example 2, Example 3, Example 4, Example 8, Example 9, and Example using a polymer having structural units derived from PMDA, CA-1 or CA-2 In Example 10, Example 11, Example 12, Example 13, and Example 14, the cumulative amount of residual DC under non-light irradiation was large as in Comparative Example 2, but was greatly reduced by light irradiation.

Table 4 shows the results of using MLC-3023, a liquid crystal composition containing alkenyl-based liquid crystal and RM. Similar to Table 3, in comparison with Table 2, its The voltage retention rate was low, and the cumulative amount of residual DC was large in Comparative Examples 3 and 4 regardless of the PSA treatment. However, in Example 5 and Examples 15 to 19, which used polymers having structural units derived from PMDA, CA-1, or CA-2, the residual DC was significantly reduced by the PSA treatment.

Therefore, in the case of using a liquid crystal composition containing an alkenyl liquid crystal, the previous method of reducing residual DC has no effect. By using a polymer containing a structural unit derived from PMDA, CA-1 or CA-2 The liquid crystal alignment film of the object, and PSA treatment can reduce the residual DC.

Similar to the examples shown in Table 3 and Table 4, the reason why the accumulation of residual DC can be reduced by using a polymer having a structural unit derived from PMDA and irradiating it with light was investigated (Table 5).

In Example 5, after using a liquid crystal alignment agent A2 containing a polymer having structural units derived from PMDA and irradiating with light, the residual DC was reduced compared to non-irradiation. In addition, after light-irradiated annealing at 150°C for 3 hours, accumulation of residual DC was found to be the same level as the result of non-irradiated light (Example 6).

Since there is almost no change in the voltage retention before and after annealing, it is not considered that the deterioration of the liquid crystal is due to the elimination of the interaction between the liquid crystal and the liquid crystal alignment film due to light irradiation. Furthermore, after light irradiation was performed again in this state (Example 7), the cumulative amount of residual DC decreased again. This also shows that there is an interaction between the liquid crystal and the liquid crystal alignment film due to light irradiation, and thereby, the cumulative amount of residual DC can be reduced.

From the above, as shown in the examples, even in the case of using a low-reliability liquid crystal composition containing an alkenyl-based liquid crystal, The liquid crystal alignment film from the polymer of the structural unit of the tetracarboxylic dianhydride (for example, PMDA) of the above formula (1) and formula (1') can reduce the accumulation of residual DC after light irradiation or PSA treatment.

〔Industrial availability〕

The liquid crystal display element obtained by the present invention can be used as a vertical alignment type liquid crystal display element such as a PSA type liquid crystal display or an SC-PVA type liquid crystal display.

In addition, all the contents of the specification, scope of patent application, and abstract of Japanese Patent Application No. 2015-22122 filed on February 6, 2015 are cited here, and those that are deemed to be the disclosure content of the specification of the present invention are imported.

Claims (5)

A liquid crystal alignment agent, characterized by comprising: the following (A) component, (B) component and organic solvent; (A) Component: at least one polymer selected from the group of polyimide precursors and polyimide precursors of the polyimide precursor, wherein the polyimide precursor system Use the diamine with the side chain to align the liquid crystal perpendicularly to account for 5-50 mole% of the diamine component; (B) Component: a polyimide precursor selected from the reaction product of a tetracarboxylic dianhydride component and a diamine component, and a polyimide group of the imide compound of the polyimide precursor At least one polymer; wherein the aforementioned tetracarboxylic dianhydride component contains 10-40 mol% selected from the group consisting of the following formula (1-1), formula (1-3) and formula (1-5) At least one tetracarboxylic dianhydride; However, when the component (B) has a side chain that aligns the liquid crystal vertically, it may be the same polymer as the component (A);

Such as the liquid crystal alignment agent of claim 1, in which the content ratio of (A) component and (B) component is calculated by mass ratio as (A) component: (B) component = X: (10-X) (X=1~9 ). The liquid crystal alignment agent of claim 1, wherein the side chain in the component (A) that vertically aligns the liquid crystal is represented by the following formula (a) By;

l, m and n each independently represent an integer of 0 or 1, R ¹ represents an alkylene group with carbon number 2-6, -O-, -COO-, -OCO-, -NHCO-, -CONH-, or carbon The number of alkylene-ether groups of 1 to 3, R ² , R ³ and R ⁴ each independently represent a phenylene, a fluorine-containing phenylene or a cyclic alkylene, R ⁵ represents a hydrogen atom, and the carbon number is 2 to 24 The alkyl group, the fluorinated alkyl group with 2-24 carbon atoms, the monovalent aromatic ring, the monovalent aliphatic ring, the monovalent heterocyclic ring, or the monovalent cyclic substituent formed by the above. A liquid crystal alignment film having a film thickness of 5 to 300 nm obtained from the liquid crystal alignment agent of any one of claims 1 to 3. A liquid crystal display element provided with the liquid crystal alignment film of claim 4.