JP4924832B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element used for forming a liquid crystal alignment film of a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent that provides a liquid crystal alignment film having good electrical characteristics and good printability, and a liquid crystal display element using the same.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. A TN liquid crystal display element having a so-called TN (twisted nematic) liquid crystal cell is known. Further, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have a higher contrast than the TN type liquid crystal display elements and have less viewing angle dependency, have been developed. The STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 ° between substrates. The birefringence effect that occurs is used.
On the other hand, as described in Non-Patent Document 1 and Patent Document 1, a vertical so-called MVA (Multi-Domain Vertical Alignment) method in which protrusions are formed on a transparent conductive film to control the alignment direction of liquid crystal. An alignment type liquid crystal display element has been proposed. The MVA liquid crystal display element is excellent in terms of manufacturing process, such as excellent viewing angle and contrast, and need not be rubbed in forming the liquid crystal alignment film. As a liquid crystal alignment film suitable for the TN, STN, and MVA methods, performance such as a short afterimage erasing time of the liquid crystal display element is required. In addition, as an alignment agent used for forming these liquid crystal alignment films, excellent printability is required in offset printing.
“Liquid Crystal” Vol. 3 No. 2 117 (1999) Japanese Patent Laid-Open No. 11-258605 JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 K. Hasegawa, Polymer Journal. Vol. 31, no. 2, 206 (1999) JP 2000-44683 A International Publication No. 2002/100949 Pamphlet

The present invention has been made in view of the above circumstances, and the object of the present invention is to maintain a voltage holding ratio and reduce accumulated charges, and further provide a liquid crystal aligning agent having excellent printability and A liquid crystal display element using the same is provided.
Still other objects and advantages of the present invention will become apparent from the following description.

  According to the present invention, the above-mentioned object of the present invention is firstly expressed by the following general formula (1).

(In the formula, R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, and R ^{4 to} R ⁷ are each independently substituted with a hydrogen atom, a monovalent aromatic group, an alkyl group or an epoxy group. an alkyl group, a ¹ and a ² are each independently a hydrogen atom, an alkyl group substituted with an alkyl group or an epoxy group, n is an integer of 1 to 100.)
It is achieved by a liquid crystal aligning agent containing a compound represented by (hereinafter referred to as “first liquid crystal aligning agent”).
Secondly, the object of the present invention is the following general formula (1 ′).

(In the formula, R ^{1 to} R ³ , A ¹ and A ² and n are the same as those in the general formula (1).)
It is achieved by a liquid crystal aligning agent (hereinafter referred to as “second liquid crystal aligning agent”) characterized by containing a polyamic acid obtained by a reaction between a compound represented by the formula and tetracarboxylic dianhydride. .
Thirdly, the object of the present invention is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from any one of the above liquid crystal aligning agents.

The 1st liquid crystal aligning agent of this invention contains the compound represented by the said Formula (1).
In the above formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group.
The alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 2-methyl-propyl group, 3 -Methyl-propyl group, n-pentyl group, n-hexyl group and the like can be mentioned.
The alkoxyl group is preferably an alkoxyl group having 1 to 6 carbon atoms, and specific examples thereof include methoxyl group, ethoxyl group, n-propoxyl group, isopropoxyl group, n-butoxyl group, 2-methyl-propoxy group. Group, 3-methyl-propoxyl group, n-pentoxyl group, n-hexyloxyl group and the like.

R ^{4 to} R ⁷ in the above formula (1) are each independently a hydrogen atom, a monovalent aromatic group, an alkyl group or an alkyl group substituted with an epoxy group.
Examples of the monovalent aromatic group include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthrene group, a pyrene group, a perylene group, an anthracene group, and a fluorene group. Group, biphenyl group, terphenyl group, naphthyl group or fluorene group are preferred.
As said alkyl group, a C1-C4 alkyl group is preferable, and a methyl group, an ethyl group, a propyl group, a butyl group etc. can be mentioned specifically ,.
The alkyl group substituted with the epoxy group preferably has 2 to 4 carbon atoms in total, and examples thereof include a glycidyl group and a 1-methylglycidyl group.
A ¹ and A ² in the above formula (1) are each independently an alkyl group substituted with a hydrogen atom, an alkyl group or an epoxy group. The alkyl group substituted with a preferable alkyl group and an epoxy group of A ¹ and A ² is the same as described above as a preferable alkyl group of R ^{4 to} R ⁷ and an alkyl group substituted with an epoxy group.
Although n of the said Formula (1) is an integer of 1-100, Preferably it is 1-50.

In the above formula (1), R ^{1 to} R ⁷ and A ¹ and A ² can be any desired combination.
Among the compounds represented by the above formula (1), the following compounds (A) to (D) are more preferable.
(A) In the above formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ are hydrogen atoms. And A ¹ and A ² are hydrogen atoms.
(B) In the above formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ are epoxy groups. A compound in which A ¹ and A ² are each independently an alkyl group substituted with a hydrogen atom or an epoxy group.
(C) In the above formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁶ are monovalent. A compound in which R ⁵ and R ⁷ are a hydrogen atom or an alkyl group, and A ¹ and A ² are each independently a hydrogen atom or an alkyl group.
(D) In the above formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁶ are monovalent. A compound in which R ⁵ and R ⁷ are alkyl groups substituted with a hydrogen atom or an epoxy group, and A ¹ and A ² are each independently an alkyl group substituted with a hydrogen atom or an epoxy group . In this case, preferably a compound in which all of R ⁵ , R ⁷ , A ¹ and A ² are hydrogen atoms is excluded.
Preferable specific examples of the compound represented by the above formula (1) include, for example, compounds represented by the following structural formula.

(In the above formula group, n is an integer of 1 to 100, preferably 1 to 50.)
The 2nd liquid crystal aligning agent of this invention contains the polyamic acid obtained by reaction with the compound represented by the said Formula (1 '), and tetracarboxylic dianhydride. As a compound represented by the above formula (1 ′), in the above formula (1 ′), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group having 1 to 6 carbon atoms. A ¹ and A ² are hydrogen atoms, and n is 1 to 50.
Preferable specific examples of the compound represented by the formula (1 ′) include, for example, compounds represented by the following structural formula.

(In the above formula group, n is an integer of 1 to 100, preferably 1 to 50.)
Examples of the tetracarboxylic dianhydride that can be used in synthesizing a polyamic acid by the reaction of the compound represented by the above formula (1 ′) with tetracarboxylic dianhydride include 1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, cis-3,7-dibutylcycloocta- 1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3 , 3a, 4 , 5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3. 2.1] Octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl -3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5 .3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, pyromellitic dianhydride, and the like. These acid anhydrides may be used alone or in combination of two or more.

When synthesizing a polyamic acid by the reaction of the compound represented by the above formula (1 ′) and tetracarboxylic dianhydride, other diamines may be used in combination with the compound represented by the above formula (1 ′). Good. Preferred examples of other diamines that can be used here include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, and 2,2′-dimethyl-4,4′-diaminobiphenyl. 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) Phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoro Propane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylene Diisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) -benzidine, N, N'-di (4-aminophenyl) -N, N Examples include '-dimethyl-benzidine. These other diamines can be used alone or in combination of two or more.
When another diamine is used in combination with the compound represented by the above formula (1 ′), the amount of the other diamine used is based on the total amount of the compound represented by the above formula (1 ′) and the other diamine. It is preferably 50% by weight or less.
The synthesis of polyamic acid from the compound represented by the above formula (1 ′) and tetracarboxylic dianhydride is a method described later as a method for synthesizing polyamic acid which is one of optional components of the liquid crystal aligning agent of the present invention. It can be performed in the same way.

  The liquid crystal aligning agent of this invention uses the polyamic acid obtained by reaction of the compound represented by the said Formula (1), or the compound represented by the said Formula (1 '), and tetracarboxylic dianhydride as an essential component. In addition, the following formula (I-1)

(Wherein P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group.)
A polyamic acid having a repeating unit represented by formula (I-2):

(Wherein P ² is a tetravalent organic group and Q ² is a divalent organic group.)
And at least one selected from the group consisting of polyimides having a repeating unit represented by the formula:
The polyamic acid having a repeating unit represented by the above formula (I-1) can be synthesized by a reaction of tetracarboxylic dianhydride and a diamine, and has a repeating unit represented by the above formula (I-2). A polyimide can be obtained by dehydrating and ring-closing a polyamic acid having a repeating unit in which P ¹ is P ² and Q ¹ is Q ² in the above formula (I-1).
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid having a repeating unit represented by the above formula (I-1) include, for example, an alicyclic tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride, An aromatic tetracarboxylic dianhydride etc. can be mentioned.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2, 3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic Acid dianhydride 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 2,3,4,5-tetrahydrofuran Tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3 -Dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3 -Dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3 -Dione, 1,3,3a, 4,5,9 b-Hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-5,8-dimethyl-5 (tetrahydro-2, -Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2- Dicarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2 , 4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2 , 6} ] undecane-3,5,8,10-tetraone The following formula (I) or (II)

(Wherein R ⁸ and R ¹⁰ are divalent organic groups having an aromatic ring, R ⁹ and R ¹¹ are hydrogen atoms or alkyl groups, and a plurality of R ⁹ and R ¹¹ are the same, May be different.)
The compound etc. which are represented by these can be mentioned.
Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride.

  Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenylsulfone. Tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl Ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1, 2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyl) Noxi) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p- Phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenyl) Phthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol- (Anhydro trimellitate), 1,4-butanediol-bis (anhydro trimellitate), 1,6-hexanediol-bis (anhydro trimellitate), 1,8-octanediol-bis ( Anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (2) to (5)

The compound etc. which are represented by these can be mentioned.
These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
Among the tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4 are used as the alicyclic tetracarboxylic dianhydride. -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride Anhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, cis- 3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6 − Anhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, , 3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, , 3,3a, 4,5,9b-Hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione , Bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione- 6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- ( , 5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6 -Dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, among the compounds represented by the above formula (I) Formula (6)-(8)

Of the compounds represented by formula (II) or the like, the following formula (9)

Are preferable from the viewpoint of exhibiting good liquid crystal orientation, and particularly preferable are 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,3-dimethyl-1. , 2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2, 5-Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride 1,3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione , 3-oxa Cyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxa Mention may be made of tricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone and compounds of the above formula (6), in particular 2,3,5-tri Carboxycyclopentyl acetic acid dianhydride is preferred.

Preferred examples of the aliphatic tetracarboxylic dianhydride and the aromatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4 '-Benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride and 1,4 , 5,8-naphthalenetetracarboxylic dianhydride.
When two or more kinds of tetracarboxylic dianhydrides are used in combination, the alicyclic tetracarboxylic dianhydride is preferably 50 mol% or more based on the total tetracarboxylic dianhydrides.

Examples of the diamine used in the synthesis of the polyamic acid having a repeating unit represented by the above formula (I-1) include aromatic diamine, aliphatic or alicyclic diamine, two primary amino groups in the molecule, and the 1 Examples thereof include diamines having a nitrogen atom other than those contained in the primary amino group, and diaminoorganosiloxanes.
Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, and 4,4′-diamino. Diphenylsulfone, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 3,3′-ditrifluoromethyl-4, 4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino -1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diamino Benzophenone, 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 [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1 , 3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-di Minofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5 , 5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diamino Biphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoro) Methylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) ) Phenoxy] - such as octafluoro biphenyl can be mentioned.

Examples of the aliphatic or alicyclic diamine include 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylene. Diamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenediethylenediamine, tricyclo [6.2.1 .0 ^2,7] - undecylenate range methyl diamine, and the like 4,4'-methylenebis (cyclohexylamine).

Examples of the diamine having two primary amino groups and nitrogen atoms other than those contained in the primary amino group in the molecule include 2,3-diaminopyridine, 2,6-diaminopyridine, and 3,4-diaminopyridine. 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5 -Triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5 -Triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3,5-to Azine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5 -Diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, Bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-di (4-aminophenyl) -benzidine, N, N′-di (4-aminophenyl) -N, N′-dimethyl-ben Jin, and the like.
Further, as the diaminoorganosiloxane, the following formula (10)

(In the formula, R ¹² represents a hydrocarbon group having 1 to ¹² carbon atoms, and a plurality of R ¹² may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) (It is an integer.)
The compound etc. which are represented by these can be mentioned.
These diamines may be used alone or in combination of two or more.

  Among these diamines, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,5-diaminonaphthalene, 2 , 7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p -Phenylenediisopropylidene) bisaniline, 4,4 '-(m-phenylenediisopropylidene) bisa Phosphorus, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6 -Diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6 -Diaminocarbazole, N-phenyl-3,6-diaminocarbazole or N, N'-di (4-aminophenyl) -benzidine, N, N'-di (4-aminophenyl) -N, N'-dimethyl- Benzidine is preferred.

  When imparting pretilt angle developability to the liquid crystal aligning agent of the present invention, a part or all of the diamine used for the synthesis of the polyamic acid having a repeating unit represented by the above formula (I-1) is represented by the following formula (Q- 1)

(In the formula, X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ¹³ has 10 to 20 carbon atoms. A monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms.)
Or the following formula (Q-2)

Wherein X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ¹⁴ has 4 to 40 carbon atoms. It is a divalent organic group having an alicyclic skeleton.
It is preferable to use a diamine having a structure represented by (hereinafter referred to as “specific diamine”). Thereby, part or all of the group Q ¹ and the group Q ^{2 in} the formula (I-1) can be a group having a structure represented by the formula (Q-1) or (Q-2), and the pretilt Contributes to the expression of horns.
In the formula (Q-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ¹³ include an n-decyl group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, and an n-octadecyl group. , N-eicosyl group and the like. Examples of the organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ¹³ in the formula (Q-1) and R ¹⁴ in the formula (Q-2) include cyclobutane, cyclopentane, and cyclohexane. Groups having an alicyclic skeleton derived from cycloalkane such as cyclodecane; groups having a steroid skeleton such as cholesterol and cholestanol; and groups having a bridged alicyclic skeleton such as norbornene and adamantane. Among these, a group having a steroid skeleton is particularly preferable. The organic group having an alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom, or a fluoroalkyl group, preferably a trifluoromethyl group.

Furthermore, examples of the group having 6 to 20 carbon atoms represented by R ¹³ in the formula (Q-1) include 6 carbon atoms such as an n-hexyl group, an n-octyl group, and an n-decyl group. In the above linear alkyl group; an alicyclic hydrocarbon group having 6 or more carbon atoms such as a cyclohexyl group or a cyclooctyl group; an organic group such as an aromatic hydrocarbon group having 6 or more carbon atoms such as a phenyl group or a biphenyl group Examples include a group in which part or all of the hydrogen atoms are substituted with a fluorine atom or a fluoroalkyl group such as a trifluoromethyl group.
X in the formula (Q-1) and the formula (Q-2) is a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S. -Or an arylene group, and examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group, and a naphthylene group.
Specific examples of the diamine having the structure represented by the above formula (Q-1) include, for example, dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, the following formulas (11) to (15)

The compound etc. which are represented by these can be mentioned.
Specific examples of the diamine having the structure represented by the above formula (Q-2) include, for example, the following formulas (16) to (18):

The compound etc. which are represented by these can be mentioned. These specific diamines may be used alone or in combination of two or more.
Of these specific diamines, compounds represented by the above formula (11), (13), (15) or (16) are preferred.
The use ratio of the specific diamine with respect to the total amount of diamine varies depending on the size of the pretilt angle to be expressed, but in the case of a TN type or STN type liquid crystal display element, 0 to 5 mol%, in the case of a vertical alignment type liquid crystal display element 5 to 100 mol% is preferable.

The acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents with respect to 1 equivalent of the amino group of the diamine used for the synthesis of the polyamic acid having the repeating unit represented by the above formula (I-1). The ratio is preferably, more preferably 0.3 to 1.2 equivalent.
The polyamic acid synthesis reaction is preferably performed at −20 ° C. to 150 ° C., more preferably 0 to 100 ° C., preferably 10 minutes to 50 hours, more preferably 30 minutes to 30 hours in an organic solvent. Is called.
Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3- Amide solvents such as butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea And aprotic polar solvents such as hexamethylphosphotriamide; and phenolic solvents such as m-cresol, xylenol, phenol, and halogenated phenol.
The amount of organic solvent used (α) is usually such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount of the reaction solution (α + β). It is preferable that

A part of the organic solvent as described above can be replaced with an alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, or the like, which is a poor solvent for polyamic acid, as long as the produced polyamic acid does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol. , Ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, isoamyl pro Pionate, isoamyl isobutyrate, diethyl oxalate, diethyl malonate, diethyl ether, diisopentyl ether, ethylene glycol methyl ether, ether Lenglycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, ben Mention may be made of down, toluene, xylene and the like.
The amount of the poor solvent that can be used here is preferably 50% by weight or less, more preferably 40% by weight or less in the total solvent.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. Further, the polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of distilling under reduced pressure with an evaporator once or several times.

The polyimide having a repeating unit represented by the above formula (I-2) dehydrates and cyclizes a polyamic acid having a repeating unit in which P ¹ is P ² and Q ¹ is Q ² in the above formula (I-1). Can be obtained.
In dehydration ring closure, all of the amic acid structure may be dehydrated and closed to form an imide ring, or only a part of the amic acid structure is dehydrated and closed to form a polymer in which the amic acid structure and the imide ring structure coexist (partial imidized product) ).
In the polyimide that can be used in the present invention, the ratio of the number of imide rings to the total of the number of imide rings and the number of amic acid structures contained in the polyimide (hereinafter referred to as “imidation ratio”) is 40 mol. % Or more, and more preferably 50 mol% or more. By using a polymer having an imidization ratio of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal aligning film having a shorter afterimage erasing time can be obtained.
The imidation ratio of polyimide is obtained from the following formula (1) from the result of measuring ¹ H-NMR at room temperature using tetramethylsilane as a reference substance after sufficiently drying the polyimide and dissolving in deuterated dimethyl sulfoxide. be able to.

Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (1)

(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a polyimide precursor (polyamic acid). The number ratio of other protons to one proton of NH group in

The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. By the method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 10 minutes to 5 hours, more preferably 30 minutes to 3 hours.

On the other hand, in the case of the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution of (ii) above, an acid anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride is used as the dehydrating agent. be able to. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of repeating units of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. The reaction time is preferably 30 minutes to 10 hours, more preferably 1 hour to 7 hours.
The reaction solution thus obtained may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. The isolated polymer may be isolated and used for the preparation of the liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for the preparation of the liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by performing the same operations as in the isolation and purification method of polyamic acid.

  The polyamic acid having a repeating unit represented by the above formula (I-1) or the polyimide having a repeating unit represented by the above formula (I-2) may be a terminal-modified type having a controlled molecular weight. By using this terminal-modified polyamic acid or polyimide, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such terminal-modified polyamic acid or polyimide can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing the polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can do. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

When the polyamic acid having the repeating unit represented by the above formula (I-1) or the polyimide having the repeating unit represented by the above formula (I-2) obtained as described above is used as a 10% solution, It is preferable to have a solution viscosity of 20 to 800 mPa · s, and more preferable to have a solution viscosity of 30 to 500 mPa · s.
The solution viscosity (mPa · s) of the polymer is a value measured at 25 ° C. using an E-type viscometer for a polymer solution having a concentration of 10% by weight using a good solvent for the polymer.

  When the liquid crystal aligning agent of the present invention contains a polyamic acid having a repeating unit represented by the above formula (I-1) or a polyimide having a repeating unit represented by the above formula (I-2), the use ratio thereof Is preferably 1,000 parts by weight or less, more preferably 10 to 500 parts by weight with respect to 1 part by weight of the compound represented by the above formula (1) in the first liquid crystal aligning agent. . On the other hand, in the second liquid crystal aligning agent, it is preferably 100% by weight with respect to 1 part by weight of polyamic acid obtained by the reaction of the compound represented by the general formula (1 ′) and tetracarboxylic dianhydride. Part or less, more preferably 5 to 80 parts by weight.

As said adhesive improvement agent, a functional silane containing compound, an epoxy compound (however, the compound represented by the said Formula (1) or (1 ')) is mentioned, for example.
Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1 4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 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, and the like can be given.
Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′, -Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N',-tetraglycidyl-4,4'-di Minodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidyl-aminomethylcyclohexane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxy Examples include silane.

  In the first liquid crystal aligning agent, the use ratio of the adhesion improver as described above is preferably 40 parts by weight or less, more preferably with respect to 100 parts by weight of the compound represented by the formula (1). Is 0.1 to 30 parts by weight. On the other hand, in the second liquid crystal aligning agent, it is preferably 30 weights with respect to 100 weight parts of polyamic acid obtained by the reaction of the compound represented by the general formula (1 ′) with tetracarboxylic dianhydride. Part or less, more preferably 0.1 to 25 parts by weight.

The liquid crystal aligning agent of this invention is a polyamic acid obtained by reaction of the compound represented by the said Formula (1), or the compound represented by the said Formula (1 '), and tetracarboxylic dianhydride, and arbitrary The other components added to are preferably dissolved in an organic solvent. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.
Examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include 1-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4- Hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n- Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide , 3-hexyloxy-N, N-dimethylpropanamide, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether and the like. These can be used alone or in admixture of two or more. Of these, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide or 3-hexyloxy-N, N-dimethylpropanamide exhibits particularly good printability. preferable.

The solid content concentration in the liquid crystal aligning agent of the present invention (the value obtained by dividing the weight of all components of the liquid crystal aligning agent by the total weight of the liquid crystal aligning agent) is selected in consideration of viscosity, volatility, and the like. However, it is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is When the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film cannot be obtained. In addition, the viscosity of the liquid crystal aligning agent may increase, resulting in poor coating characteristics.
The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity of the liquid crystal aligning agent is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity of the liquid crystal aligning agent is in the range of 3 to 15 mPa · s.

The liquid crystal display element of the present invention comprises an alignment film formed from the liquid crystal aligning agent of the present invention.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) A liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by an offset printing method, a spin coating method, or an ink jet printing method to form a coating film. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly (alicyclic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound or the like is applied in advance to the substrate surface. Also good. After applying the liquid crystal aligning agent, it is preferable to perform preheating (pre-baking) for the purpose of preventing dripping. The pre-baking temperature is preferably 30 to 300 ° C, more preferably 40 to 200 ° C, and particularly preferably 50 to 150 ° C. Thereafter, a baking (post-baking) step is performed for the purpose of completely removing the solvent. The post-baking temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. Thus, the liquid crystal aligning agent of this invention forms the coating film used as a liquid crystal aligning film by removing an organic solvent after application | coating. When the liquid crystal aligning agent of the present invention contains a polyamic acid or a partially imidized product thereof, the film is further imidized by further proceeding with dehydration and ring closure of the amic acid structure by optionally further heating. It is good. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) A rubbing process is performed in which the formed coating film surface is rubbed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon (registered trademark), and cotton. Thereby, the orientation ability of liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation film. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is disclosed in, for example, Patent Document 2 (Japanese Patent Laid-Open No. 6-222366) and Patent Document 3 (Japanese Patent Laid-Open No. 6-281937). The surface of the liquid crystal alignment film subjected to a rubbing treatment as shown in Patent Document 4 (Japanese Patent Application Laid-Open No. 5-107544) or a treatment that changes the pretilt angle by partially irradiating ultraviolet rays. By forming a resist film partially and performing rubbing treatment in a direction different from the previous rubbing treatment, removing the resist film and changing the liquid crystal aligning ability of the liquid crystal alignment film, liquid crystal display It is possible to improve the visibility characteristics of the element.

(3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the two substrates are separated by a gap (cell gap) so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. ), And the periphery of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, and the injection hole is sealed. A liquid crystal cell is constructed. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together. Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
In the following examples and comparative examples, the liquid crystal aligning agent and the liquid crystal alignment film obtained therefrom were evaluated according to the following methods.
[Solution viscosity of polymer]
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type rotational viscometer for the polymer solution having a concentration of 10% by weight using the good solvent of the polymer indicated in each example. did.
[Voltage holding ratio]
A voltage of 5 V was applied to the liquid crystal display element at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the application release was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation.
[Burn-in test]
A cell having an ITO electrode as shown in FIG. 1 was produced. A DC voltage of 6.0 V was applied to the electrode A, and a DC voltage of 0.5 V was applied to the electrode B at room temperature for 24 hours. After removing the voltage, the image sticking characteristics after applying a DC voltage of 0.1 to 5.0 V to the electrodes A and B in increments of 0.1 V were evaluated. “◯” indicates that no seizure is observed, “Δ” indicates that the seizure is weak, and “x” indicates that the seizure is strong.
[Printability evaluation]
A 127 mm (D) × 127 mm (W) × 1.1 mm (H) glass substrate with an ITO film formed on the entire surface of one side is prepared, and a liquid crystal alignment film coating printer (Nissha Printing Co., Ltd.) is prepared on this glass substrate. The liquid crystal aligning agent obtained in each example or each comparative example was filtered through a microfilter having a pore size of 0.2 μm using an angstromer S-40L), and then applied to the transparent electrode surface. The solvent was removed with a hot plate close-contact type pre-dryer set at 80 ° C. and baked at 200 ° C. for 60 minutes to form a liquid crystal alignment film on the glass substrate with the ITO film. The unevenness of the obtained alignment film was visually evaluated. The case where no unevenness was observed was indicated by “◯”, and the case where unevenness was observed was indicated by “X”.

Synthesis example 1
Synthesis Example 1 was performed according to Non-Patent Document 2 (K. Hasegawa, Polymer Journal. Vol. 31, No. 2, 206 (1999)).
Under a nitrogen atmosphere, 6.24 g (20 mmol) of 4,4′-dibromobiphenyl and 2.16 g (20 mmol) of paraphenylenediamine were placed in a 300 ml three-necked flask, and dissolved by adding 80 ml of toluene. To this, sodium tert-butoxide 5.8 (60 mmol), tris (dibenzylideneacetone) -dipalladium (Pd ₂ (dba) ₃ ) 0.46 g (0.5 mmol) and 2,2′-bis (diphenyl) Phosphino) -1,1′-binaphthyl (BINAP) 0.93 grams (1.5 mmol) was added at room temperature. The reaction solution was stirred and reacted at 100 ° C. for 16 hours under nitrogen. The reaction solution was returned to room temperature and washed with 2 liters of a mixed solution of 25% by weight ammonia water and methanol (ammonia water / methanol = 1/4 (volume ratio)) using a separatory funnel. The organic solvent layer is dehydrated with sodium sulfate, concentrated with a rotary evaporator, and the resulting crude product is purified by silica gel column chromatography to obtain the following formula (A-1).

(In the formula, m is the number of repetitions.)
2.1 g of the compound A-1 represented by the formula:
By repeating the same operation, an amount of compound A-1 sufficient for use in the following experimental examples was secured.

Synthesis example 2
In a three-necked flask, 10 g of Compound A-1 synthesized in Synthesis Example 1 was dissolved in 50 mL of dimethyl sulfoxide (DMSO). An excess amount of an aqueous potassium carbonate solution was mixed with this solution. After cooling this mixture in an ice bath, a DMSO solution of epibromohydrin (concentration 1 mol / L) was added dropwise until an excessive amount was reached. After completion of the dropwise addition, the temperature was returned to room temperature, and stirring was continued for 48 hours. The reaction mixture was filtered, and the filtrate was separated and washed with chloroform / saturated saline. Thereafter, the solvent is distilled off, and reprecipitation with methanol is performed.

(In the formula, m ′ and m ″ are the number of repetitions.)
The mixture A-2 of the compound represented by these was obtained.

Polyimide synthesis example 1
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 96 g (0.89 mol) as the diamine compound, 3 , 3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine) 25 g (0.10 mol) and 3,6-bis (4-aminobenzoyloxy) cholestane 13 g (0.020 mol) and As a monoamine, 8.1 g (0.030 mol) of n-octadecylamine was dissolved in 960 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. I let you. A small amount of the resulting polyamic acid solution was taken, and N-methyl-2-pyrrolidone was added to measure the solution viscosity of the polymer as a solution having a concentration of 10% by weight. As a result, it was 60 mPa · S.
2,700 g of N-methyl-2-pyrrolidone was added to the polyamic acid solution obtained above, 396 g of pyridine and 409 g of acetic anhydride were further added, and a dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the reaction, the solvent in the system was replaced with a new γ-butyrolactone (the pyridine and acetic anhydride used for the imidization reaction were removed from the system by this operation), and a polyimide having an imidization ratio of about 95% ( About 2,000 g of a solution containing 15% by weight of a-1) was obtained.
The solution viscosity (solvent: γ-butyrolactone) at a concentration of 10% by weight of polyimide (A-1) was 70 mPa · S.

Polyimide synthesis example 2
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 108 g (1.0 mol) of p-phenylenediamine and cholesteryl-3,5-diamino as diamine compounds 7.8 g (0.015 mol) of benzoate was dissolved in 3,039 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution having a solution viscosity of about 260 mPa · S. Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 396 g of pyridine and 306 g of acetic anhydride were further added, and a dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the reaction, the solvent in the system was replaced with a new γ-butyrolactone (the pyridine and acetic anhydride used for the imidization reaction were removed from the system in this operation), and a polyimide having an imidization ratio of about 51% ( About 3,000 g of a solution containing 9% by weight of a-2) was obtained.
The solution viscosity (solvent: γ-butyrolactone) at a concentration of 10% by weight of polyimide (A-2) was 70 mPa · S.

Polyamic acid synthesis example 1
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1 of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound) 0.0 mol) is dissolved in a mixed solvent consisting of 370 g of N-methyl-2-pyrrolidone and 3,300 g of γ-butyrolactone and reacted at 40 ° C. for 3 hours to obtain a solution viscosity (solvent: N-methyl-2-pyrrolidone). ) About 3,700 g of a solution containing 160 mPa · S polyamic acid (I-1) was obtained.

Polyamic acid synthesis example 2
95 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 109 g (0.50 mol) of pyromellitic dianhydride and 2,7 as diamine compound -196 g (1.0 mol) of diaminofluorene was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,060 g of γ-butyrolactone, reacted at 40 ° C for 3 hours, and then 1,350 g of γ-butyrolactone. Was added to obtain about 3,600 g of a solution containing polyamic acid (I-2).
The solution viscosity (solvent: mixed solvent composed of N-methyl-2-pyrrolidone and γ-butyrolactone) at a concentration of 10% by weight of polyamic acid (I-2) was 125 mPa · S.

Example 1
The polyimide (A-1) obtained in Polyimide Synthesis Example 1 and the polyamic acid (I-1) obtained in Polyamic Acid Synthesis Example 1 are polyimide: polyamic acid = 20: 80 (weight ratio). It is dissolved in a mixed solvent of γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve (weight ratio 71/17/12), and N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane is dissolved therein. 2 parts by weight with respect to 100 parts by weight of the polymer, and further 10 parts by weight of the compound A-1 obtained in Synthesis Example 1 as a compound represented by the formula (1) with respect to 100 parts by weight of the polymer. A solution having a solid concentration of 3.5% by weight and a solution having a solid content of 6.0% by weight were prepared. After sufficiently stirring each solution, the liquid crystal aligning agent of the present invention was prepared by filtering using a filter having a pore size of 1 μm.
Among the liquid crystal aligning agents, a solution having a solid content concentration of 3.5% is applied onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm using a spinner (rotation speed: 2500 rpm). , Coating time: 1 minute) and dried at 200 ° C. for 1 hour to form a film having a dry film thickness of 0.08 μm. By using a rubbing machine having a roll in which a rayon cloth is wound around this film, a rubbing process is performed at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to obtain a liquid crystal alignment film. . The substrate on which the liquid crystal alignment film was formed was ultrasonically cleaned in ultrapure water for 1 minute, and then dried in a clean oven set at 100 ° C. for 10 minutes. Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is provided at the outer edges of the pair of transparent electrodes / transparent electrode substrates on which the liquid crystal alignment film of the substrate is formed, leaving a liquid crystal injection port. After the coating, the liquid crystal alignment film surfaces were overlapped and pressed so as to face each other, and the adhesive was cured. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to produce a liquid crystal display element. . The voltage holding ratio evaluation and image sticking evaluation of the obtained liquid crystal display element were performed according to the methods described above.
Moreover, printability evaluation was performed according to the method described above using a solution having a solid content concentration of 6.0% by weight.

Examples 2-4
The same procedure as in Example 1 was carried out except that the compounds represented by the above formula (1), polyimide and polyamic acid were used as described in Table 1.
Example 5
The polyimide (A-2) obtained in the polyimide synthesis example 2 was dissolved in an N-methyl-2-pyrrolidone / butyl cellosolve mixed solvent (weight ratio 50/50), and N, N, N ′, N′— 2 parts by weight of tetraglycidyl-4,4′-diaminodiphenylmethane is added to 100 parts by weight of the polymer, and the compound A-1 obtained in Synthesis Example 1 as a compound represented by the above formula (1) is polymerized. 10 parts by weight was added to 100 parts by weight to prepare a solution having a solid content concentration of 3.5% by weight and a solution having a weight of 6.0% by weight. After sufficiently stirring each solution, the liquid crystal aligning agent of the present invention was prepared by filtering using a filter having a pore size of 1 μm. The method for producing the liquid crystal display element, the method for evaluating the liquid crystal display element, and the method for evaluating the orientation agent printability were performed in the same manner as in Example 1.
Example 6
The same procedure as in Example 5 was performed except that the compounds represented by the above formula (1) were used as described in Table 1.

Comparative Examples 1-2
The same procedure as in Example 1 was used except that the polyimide and polyamic acid described in Table 1 were used and the compound represented by the above formula (1) was not added.
Comparative Example 3
The same procedure as in Example 5 was performed except that the compound represented by the above formula (1) was not added.
Comparative Examples 4-5
In Example 1, the polyimide and polyamic acid described in Table 1 were used, and the following structure was used instead of the compound represented by the above formula (1).

The same procedure as in Example 1 was performed except that a compound represented by the formula (hereinafter referred to as “compound X”) was used. Compound X was synthesized according to the method described in Patent Document 5 (Japanese Patent Application Laid-Open No. 2000-44683).
Comparative Example 6
In Example 5, the same procedure as in Example 5 was performed except that Compound X was used instead of the compound represented by Formula (1).
Comparative Examples 7-8
In Example 1, the polyimide and polyamic acid used were those listed in Table 1, and the following structure was used instead of the compound represented by the above formula (1).

The same procedure as in Example 1 was performed except that a polymer having a repeating unit represented by (hereinafter referred to as polymer Y) was used. The polymer Y was synthesized according to the method described in Patent Document 6 (WO 2002/100949 pamphlet). The number average molecular weight Mn was 15,000 and the weight average molecular weight Mw was 30,000.
Comparative Example 9
In Example 5, the same procedure as in Example 5 was performed except that the polymer Y was used instead of the compound represented by the above formula (1).
All the above results are summarized in Table 1. In Table 1, “-” indicates that the component corresponding to the column was not used. Further, “> 99%” in the voltage holding ratio column indicates that the measured value exceeds 99%.

It is a schematic diagram of the cell produced for the burn-in test in an Example and a comparative example.

Claims (9)

The following general formula (1)

(In the formula, R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, and R ^{4 to} R ⁷ are each independently substituted with a hydrogen atom, a monovalent aromatic group, an alkyl group or an epoxy group. an alkyl group, a ¹ and a ² are each independently a hydrogen atom, an alkyl group substituted with an alkyl group or an epoxy group, n is an integer of 1 to 100.)
The liquid crystal aligning agent characterized by containing the compound represented by these. In the general formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and A ¹ and A ² are hydrogen atoms. The liquid crystal aligning agent of Claim 1. In the general formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ are substituted with an epoxy group. The liquid crystal aligning agent according to claim 1, wherein each of A ¹ and A ² is an alkyl group independently substituted with a hydrogen atom or an epoxy group. In General Formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁶ are monovalent aromatics. a group, R ⁵ and R ⁷ is a hydrogen atom or an alkyl group, a ¹ and a ² are each independently hydrogen atom or an alkyl group, a liquid crystal aligning agent of claim 1. In General Formula (1), R ^{1 to} R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁶ are monovalent aromatics. And R ⁵ and R ⁷ are alkyl groups substituted with a hydrogen atom or an epoxy group, and A ¹ and A ² are each independently an alkyl group substituted with a hydrogen atom or an epoxy group. Liquid crystal aligning agent as described in. The following general formula (1 ')

(In the formula, R ^{1 to} R ³ , A ¹ and A ² and n are the same as those in the general formula (1).)
The liquid crystal aligning agent characterized by containing the polyamic acid obtained by reaction with the compound represented by these, and tetracarboxylic dianhydride. Furthermore, the following formula (I-1)

(Wherein P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group.)
A polyamic acid having a repeating unit represented by formula (I-2):

(Wherein P ² is a tetravalent organic group and Q ² is a divalent organic group.)
The liquid crystal aligning agent as described in any one of Claims 1-6 containing at least 1 sort (s) selected from the group which consists of a polyimide which has a repeating unit represented by these.   Containing a polyamic acid having a repeating unit represented by the above formula (I-1) and a polyimide having a repeating unit represented by the above formula (I-2), and these polyamic acid and polyimide are 2, 3, 5- The liquid crystal aligning agent of Claim 7 which is synthesize | combined from the tetracarboxylic dianhydride containing tricarboxycyclopentyl acetic acid dianhydride and diamine.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.

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