JP2005139288A - Liquid crystal-aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a liquid crystal-aligning agent, which forms a liquid crystal-aligned film having excellent vertical alignment of liquid crystal and is suitable for a vertical alignment type liquid-crystal display element. <P>SOLUTION: The liquid crystal-aligning agent comprises a polymer having at least one structure selected from the group consisting of a structure represented by formula (I) (A<SP>1</SP>and B<SP>1</SP>are mutually independently a hydrogen atom, a halogen atom or a cyano group with the proviso that at least one of A<SP>1</SP>and B<SP>1</SP>is a halogen atom or a cyano group) and a structure represented by formula (II) at a side chain. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent having a vertical alignment suitable for use in a vertical alignment type liquid crystal display element, and a liquid crystal display element including a liquid crystal alignment film obtained therefrom.

  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 90 degrees from one substrate to the other. A TN type liquid crystal display element having a so-called TN type (Twisted Nematic) liquid crystal cell is well known.

  On the other hand, a vertical alignment type liquid crystal display element is one in which a liquid crystal having negative dielectric anisotropy is vertically aligned and operated by tilting liquid crystal molecules by applying a voltage, and is excellent in view angle and contrast. In recent years, research and development has been conducted extensively.

  Here, in order to vertically align the liquid crystal, it is necessary to make the liquid crystal alignment film hydrophobic. For this reason, the alignment agent contains a large amount of hydrophobic components (hereinafter also referred to as vertical alignment components). It is necessary to make it. As such a vertical alignment component, those having an aliphatic, alicyclic or fluorine functional group are often used. However, when such a vertical alignment component is used, there is a problem that the stability of the vertical alignment is not always sufficient.

  Accordingly, development of a liquid crystal aligning agent having excellent vertical alignment stability is desired.

  An object of the present invention is to provide a vertical alignment type liquid crystal aligning agent having excellent vertical alignment stability.

  Another object of the present invention is to provide a liquid crystal display device comprising a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

  Still other objects and advantages of the present invention will become apparent from the following description.

  According to the present invention, the above objects and advantages of the present invention are, firstly, at least one selected from the group consisting of a structure represented by the following formula (I) and a structure represented by the following formula (II): A liquid crystal aligning agent comprising a polymer having one structure in a side chain

(In the formula, A ¹ and B ¹ are each independently a hydrogen atom, a halogen atom or a cyano group, provided that at least one of A ¹ and B ¹ is a halogen atom or a cyano group. .)

 Is achieved.

  According to the present invention, secondly, the above objects and advantages of the present invention are achieved by a liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention. .

  According to the present invention, when a liquid crystal alignment film is used, a liquid crystal aligning agent suitable for a vertical alignment type liquid crystal display element capable of forming a liquid crystal alignment film having good liquid crystal vertical alignment can be provided.

  Hereinafter, the present invention will be described in detail.

The liquid crystal aligning agent of the present invention comprises a polymer having a structure represented by the above formula (I) or a structure represented by the above formula (II) in a side chain (hereinafter also referred to as “specific side chain”). contains. In the above formula (I), A ¹ and B ¹ are each independently a hydrogen atom, a halogen atom or a cyano group. However, at least ^one of A ¹ and B ¹ is a halogen atom or a cyano group. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Among these, a fluorine atom is preferable.

  Specific examples of the specific side chain include groups having a structure represented by the following formula (III).

P in the formula (III) is a single bond, —O—, —COO— or —CONH—, and Q is a structure represented by the above formula (I) or a structure represented by the above formula (II). Further, R ¹ in formula (III) is a divalent alicyclic group. More specifically, as an alicyclic ring of a divalent alicyclic group, more specifically, a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a bicyclohexyl ring, a tercyclohexyl ring, and these A ring in which one or two or more hydrogen atoms contained in the ring are substituted with a monovalent organic group such as an alkyl group, an aryl group, an alkoxyl group, an aryloxyl group, or a halogen atom can be given. R ² in the above formula (III) is a linear alkyl group having 1 to 22 carbon atoms, preferably a linear alkyl group having 2 to 18 carbon atoms, and particularly preferably a carbon number. 3 to 10 linear alkyl groups.

  The skeleton structure of the polymer having such a specific side chain is not particularly limited, but from the viewpoint of excellent heat resistance and electrical properties, it is a polyamic acid and an imidized polymer obtained by dehydrating and ring-closing polyamic acid. Preferably there is.

  The polyamic acid can be obtained by polycondensing a diamine (I) represented by the following formula (IV) and an acid anhydride (B) represented by the following formula (V). The imidized polymer can be obtained by dehydrating and ring-closing the polyamic acid. For the synthesis of the polyamic acid and imidized polymer having a specific side chain used in the liquid crystal aligning agent of the present invention, a compound having a specific side chain in at least one of (i) diamine and (ro) acid anhydride Is used.

(In the formula, Z ¹ represents a divalent organic group.)

(In the formula, Z ² represents a tetravalent organic group.)
The proportion of the diamine or acid anhydride having a specific side chain is preferably 1 to 100 mol% based on the total of all diamines (I) and all acid anhydrides (B) used. More preferably, it is 5 to 50%.

<Diamine>
Specific examples of the diamine having a specific side chain include 1- (2,3-difluoro-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3- Difluoro-4- (4-n-butylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene 1- (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenoxy ) -2,4-diaminobenzene;
1- (2,3-dicyano-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-butylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4) -N-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
(2,3-difluoro-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-butylcyclohexyl) phenyl) -3,5 -Diaminobenzoate, (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
(2,3-dicyano-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-butylcyclohexyl) phenyl) -3,5 -Diaminobenzoate, (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
1- (6- (4-n-propylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n-butylcyclohexyl) -3-pyridazinyl Oxy) -2,4-diaminobenzene, 1- (6- (4-n-pentylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n- Hexylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n-heptylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene;
(6- (4-n-propylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- (4-n-butylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6 -(4-n-pentylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- (4-n-hexylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- ( 4-n-heptylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate;
1- (2-Fluoro-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-fluoro-4- (4-n-butylcyclohexyl) phenoxy) -2,4 -Diaminobenzene, 1- (2-fluoro-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-fluoro-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-fluoro-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
1- (3-Fluoro-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-fluoro-4- (4-n-butylcyclohexyl) phenoxy) -2,4 -Diaminobenzene, 1- (3-fluoro-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-fluoro-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-fluoro-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
1- (2-cyano-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-cyano-4- (4-n-butylcyclohexyl) phenoxy) -2,4 -Diaminobenzene, 1- (2-cyano-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-cyano-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2-cyano-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
1- (3-cyano-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-cyano-4- (4-n-butylcyclohexyl) phenoxy) -2,4 -Diaminobenzene, 1- (3-cyano-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-cyano-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (3-cyano-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
(2-fluoro-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-fluoro-4- (4-n-butylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-fluoro-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-fluoro-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-fluoro-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
(3-fluoro-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-fluoro-4- (4-n-butylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-fluoro-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-fluoro-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-Fluoro-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
(2-cyano-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-cyano-4- (4-n-butylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-cyano-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-cyano-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2-cyano-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
(3-cyano-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-cyano-4- (4-n-butylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-cyano-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (3-cyano-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, Mention may be made of (3-cyano-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate. Of these, 1 (2,3-difluoro-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4- (4-n-butylcyclohexyl) ) Phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4 -(4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
1- (2,3-dicyano-4- (4-n-propylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-butylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4) -N-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene, 1- (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenoxy) -2,4-diaminobenzene;
(2,3-difluoro-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-butylcyclohexyl) phenyl) -3,5 -Diaminobenzoate, (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
(2,3-dicyano-4- (4-n-propylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-butylcyclohexyl) phenyl) -3,5 -Diaminobenzoate, (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-hexylcyclohexyl) phenyl) -3,5-diaminobenzoate, (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenyl) -3,5-diaminobenzoate;
1- (6- (4-n-propylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n-butylcyclohexyl) -3-pyridazinyl Oxy) -2,4-diaminobenzene, 1- (6- (4-n-pentylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n- Hexylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene, 1- (6- (4-n-heptylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene;
(6- (4-n-propylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- (4-n-butylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6 -(4-n-pentylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- (4-n-hexylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate, (6- ( 4-n-heptylcyclohexyl) -3-pyridazinyl) -3,5-diaminobenzoate is preferred.

Examples of other diamines used for the synthesis of the polymer contained in the liquid crystal aligning agent of the present invention include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl. Ethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diamino Diphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-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′-di Minobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 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- 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′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino -2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoro) Aromatic diamines such as methyl) phenoxy] -octafluorobiphenyl;
Metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diamino Cyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylene diamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyl diamine, 4,4'- Aliphatic and cycloaliphatic diamines such as methylenebis (cyclohexylamine);
2,3-diaminopyridine, 2,6-diaminopyridine, 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-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 2 in the molecule such as phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine and compounds represented by the following formulas (VI) to (VII) A diamine having one primary amino group and a nitrogen atom other than the primary amino group;

(Wherein R ³ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ represents a divalent organic group.)

(In the formula, R ⁴ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² represents a divalent organic group, and there are a plurality of them. X ² may be the same or different.)
Monosubstituted phenylenediamines represented by the following formula (VIII); diaminoorganosiloxanes represented by the following formula (IX);

(Wherein R ⁵ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁶ represents a steroid skeleton, A monovalent organic group having a group selected from a fluoromethyl group and a fluoro group or an alkyl group having 6 to 30 carbon atoms is shown.)

(Wherein R ⁷ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁷ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)
Examples include compounds represented by the following formulas (1) to (5). These diamine compounds can be used alone or in combination of two or more.

(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)
Among these, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 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) bisaniline, 1,4-cyclohexanediamine 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-amino) Enoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, compounds represented by the above formulas (1) to (5), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4 -Diaminopyrimidine, 3,6-diaminoacridine, a compound represented by the following formula (6) among the compounds represented by the above formula (VI), and a compound represented by the following formula (7) among the compounds represented by the above formula (VII) Among the compounds represented by the following formulas (8) to (17) and the compounds represented by the above formula (IX) among the compounds represented by , 3-bis (3-aminopropyl) hexamethyldisiloxane is preferred.

<Tetracarboxylic dianhydride>
Specific examples of the tetracarboxylic dianhydride having a specific side chain include 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n-propyl). (Cyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-4- (2,3-difluoro-4- (4-n-butylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan -1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2, 5-Dioxo-3-fura L) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n- (Hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b -Hexahydro-4- (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c]- Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenoxy) -5- (tetrahydro-2 , 5-Dioxo-3-furanyl) Naphtho [1,2-c] - 1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (2,3-dicyano-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-dicyano-4- (4-n-butyl) (Cyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-4- (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan -1,3-dione, 1,3,3a, , 5,9b-Hexahydro-4- (2,3-dicyano-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 -C] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenoxy) -5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (6- (4-n-propylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (6- (4-n-butylcyclohexyl) -3- Pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-4- (6- (4-n-pentylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c ] -Furan-1,3-dione, 1,3,3a, 4,5,9b Hexahydro-4- (6- (4-n-hexylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c]- Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (6- (4-n-heptylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (2-fluoro-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-fluoro-4- (4-n-butylcyclohexyl) phenoxy) -5- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-Fluoro-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 1,3,3a, 4,5,9b Hexahydro-4- (2-fluoro-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-fluoro-4- (4-n-heptylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (3-fluoro-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (3-fluoro-4- (4-n-butylcyclohexyl) phenoxy) -5- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (3-Fluoro-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 1,3,3a, 4,5,9b Hexahydro-4- (3-fluoro-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (3-fluoro-4- (4-n-heptylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-4- (2-cyano-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-cyano-4- (4-n-butylcyclohexyl) phenoxy) -5- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-Cyano-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 1,3,3a, 4,5,9b-hex Hydro-4- (2-cyano-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2-cyano-4- (4-n-heptylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-4- (3-cyano-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (3-cyano-4- (4-n-butylcyclohexyl) phenoxy) -5- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (3-Cyano-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione ,
1,3,3a, 4,5,9b-Hexahydro-4- (3-cyano-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione and 1,3,3a, 4,5,9b-hexahydro-4- (3-cyano-4- (4-n-heptylcyclohexyl) Mention may be made of phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione.

Of these, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo -3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4) -N-butylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4 5,9b-Hexahydro-4- (2,3-difluoro-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] -furan-1,3-di 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-difluoro-4- (4-n) -Hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-4- (2,3-difluoro-4- (4-n-heptylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -Furan-1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (2,3-dicyano-4- (4-n-propylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-dicyano-4- (4-n-butyl) (Cyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-4- (2,3-dicyano-4- (4-n-pentylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan -1,3-dione, 1,3,3a, , 5,9b-Hexahydro-4- (2,3-dicyano-4- (4-n-hexylcyclohexyl) phenoxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 -C] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (2,3-dicyano-4- (4-n-heptylcyclohexyl) phenoxy) -5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-Hexahydro-4- (6- (4-n-propylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-4- (6- (4-n-butylcyclohexyl) -3- Pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-4- (6- (4-n-pentylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c ] -Furan-1,3-dione, 1,3,3a, 4,5,9b Hexahydro-4- (6- (4-n-hexylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c]- Furan-1,3-dione and 1,3,3a, 4,5,9b-hexahydro-4- (6- (4-n-heptylcyclohexyl) -3-pyridazinyloxy) -5- ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione is preferred.

  Other tetracarboxylic dianhydrides used for the synthesis of the polymer contained in the liquid crystal aligning agent of the present invention include, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid Dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2 , 3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2 3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic 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, 4,5,9b-Hexahydro-7- Tyl-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-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Anhydride, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4- Aliphatic and alicyclic tetracarboxylic dianhydrides such as dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), compounds represented by the following formulas (X) and (XI);

(Wherein R ⁸ and R ¹⁰ represent a divalent organic group having an aromatic ring, R ⁹ and R ¹¹ represent a hydrogen atom or an alkyl group, and a plurality of R ⁹ and R ¹¹ are the same. But it may be different.)
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-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 (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydro trimellitate), propylene glycol-bis (anhydro trimellitate) 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydride) Trimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (18) to (21) An aromatic tetracarboxylic dianhydride such as a compound represented by These may be used alone or in combination of two or more.

  Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- ( 2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic 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-8-methyl-5- (tetrahydro-2,5 − Oxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 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 Acid dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride Of the anhydrides, compounds represented by the above formula (X) Among the compounds represented by the formulas (22) to (24) and the compound represented by the above formula (XI), the compound represented by the following formula (25) can exhibit good liquid crystal alignment. It is preferable from the viewpoint. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5 Cyclohexanetetracarboxylic 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, 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'-Geo ), It may be mentioned compounds represented by pyromellitic dianhydride and the following formula (22).

<Synthesis of polyamic acid>
The ratio of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is 0.2 to 2 equivalents of tetracarboxylic dianhydride acid anhydride group to 1 equivalent of amino group of diamine. The ratio is preferably, more preferably 0.3 to 1.2 equivalent.

  The polyamic acid synthesis reaction is preferably performed in an organic solvent under a temperature condition of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C. 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, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount (α) of the organic solvent used is preferably such that the total amount (β) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight based on the total amount (α + β) of the reaction solution. Such an amount is preferred.

  In addition, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are poor solvents for polyamic acid, are used in combination with the organic solvent as long as the resulting polyamic acid does not precipitate. be able to. Specific examples of such a poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, and triethylene. Glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, Diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol 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, benzene, toluene, xylene and the like.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. The reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. The polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Synthesis of imidized polymer>
The imidized polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing the polyamic acid. The polyamic acid is dehydrated and closed by (I) 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. In addition, the imidized polymer used in the present invention has an imidization ratio (the ratio of the repeating unit formed with an imide ring in all repeating units in the polymer in%) that is partially dehydrated and closed. An imidized polymer having a molecular weight of less than 100%.

  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 (B) obtained may decrease.

  On the other hand, in the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution of (II) above, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used. Can do. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, Preferably it is 0.01-20 mol with respect to 1 mol of repeating units of a polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. 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 imidization rate can be increased as the amount of the 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 the reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. In addition, the imidized polymer can be purified by performing the same operation as the polyamic acid purification method on the reaction solution thus obtained.

<End-modified polymer>
The polyamic acid and the imidized polymer may be of a terminal modified type with a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified type 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.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving a polymer having a specific side chain, usually a polyamic acid and / or an imidized polymer, in an organic solvent.

  The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

  As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together. Among these, it is preferable to use 1-methyl-2-pyrrolidone and a solvent having a surface tension of 32 dyn / cm or less. Examples of the solvent having a surface tension of 32 dyn / cm or less include 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, and 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, 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, and the like diethylene glycol monoethyl ether acetate.

  The ratio of 1-methyl-2-pyrrolidone to a solvent having a surface tension of 32 dyn / cm or less is 20 to 60% by weight of 1-methyl-2-pyrrolidone, and 80 to 40% by weight of a solvent having a surface tension of 32 dyn / cm or less. Preferably there is. If the ratio is out of the range, the polymer may precipitate or the leveling may be insufficient, so that sufficient printability cannot be obtained.

  The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but 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 increases, resulting in poor coating characteristics.

  The liquid crystal aligning agent of this invention may contain the functional silane containing compound and the epoxy compound from a viewpoint which improves the adhesiveness with respect to the substrate surface within the range which does not impair the target physical property. Examples of such functional silane-containing compounds 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- , 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, etc. can be mentioned. Examples of the epoxy group-containing 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, 1,6 -Hexanediol 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'-diaminodiphenylmethane, 3- (N-Ariru N Gurishijiru) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) and the like aminopropyltrimethoxysilane.

<Liquid crystal display element>
The liquid crystal display element obtained using the liquid crystal aligning agent of this invention can be manufactured, for example with the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, or a printing method, and then the coated surface is heated. Thus, a coating film is formed. 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, or polycarbonate can be used. As the 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-containing compound, a functional titanium-containing compound, or the like is previously applied to the surface of the substrate. You can also The heating temperature after application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. In addition, the liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film that becomes an alignment film by removing the organic solvent after coating, but further proceeds with dehydration ring closure by further heating, and is further imidized. It can also be set as a coating film. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

  (2) The rubbing process which rubs the formed coating film surface in a fixed direction with the roll which wound the cloth which consists of fibers, such as nylon, rayon, cotton, for example as needed is performed. Thereby, a pretilt angle can be given to the liquid crystal molecules on the coating film, and the direction in which the liquid crystal molecules are tilted when a voltage is applied can be controlled. In some cases, the pretilt angle may be given by irradiating the coating film with polarized or non-polarized ultraviolet rays, an ion beam, or the like without depending on the rubbing method.

  Further, in the vertical alignment type liquid crystal display device of the present invention, when the direction in which the liquid crystal molecules are tilted when a voltage is applied is controlled by a lateral electric field, a protrusion on the substrate, etc., it is always necessary to perform the above-described processing such as rubbing. Instead, the coating film can be used as it is as a liquid crystal alignment film.

  (3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the rubbing direction (or the tilt direction of the liquid crystal molecules when a voltage is applied) in each liquid crystal alignment film is antiparallel. Two substrates are placed facing each other with a gap (cell gap) between them, and the peripheral portions of the two substrates are bonded together using a sealant, and the liquid crystal is placed in the cell gap defined by the substrate surface and the sealant. The liquid crystal cell is formed by filling and filling and sealing the injection hole. Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, the other surface side of each substrate constituting the liquid crystal cell, and the rubbing direction (or voltage) of the liquid crystal alignment film whose polarization direction is formed on one surface of the substrate. A liquid crystal display element is obtained by bonding the liquid crystal molecules so as to form an angle of 45 ° with the tilt direction of the liquid crystal molecules during application.

  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, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, and bicyclooctane. Type liquid crystal, cubane type liquid crystal and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used.

  In addition, 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 is stretched and oriented while sandwiching polyvinyl alcohol with a cellulose acetate protective film. 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 addition, the evaluation method of the liquid crystal display element in a following example and a comparative example is as follows.

<Pretilt angle of liquid crystal display element>
T.A. J. et al. Scheffer, et. al. , J .; Appl. Phys. , Vol. 19, 2013 (1980), and measured by a crystal rotation method using He—Ne laser light (here, the pretilt angle is defined as the angle at which the alignment direction of liquid crystal molecules is inclined from the substrate surface). .)

Synthesis example 1
The polymerization of the polyamic acid 2,3,5-tricarboxycyclopentylacetic dianhydride 0.1 mol (22.4 g) and 1- (2,3-Difluoro-4-(4-n-hexyl cyclohexyl) phenoxy) -2 , 4-Diaminobenzene 0.1 mol (40.3 g) was dissolved in 300 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. Then, it wash | cleaned with methanol and it was made to dry at 40 degreeC under pressure reduction for 15 hours, and 62 g of polyamic acids (henceforth "the polymer 1a") were obtained.
Imidation reaction To 31.2 g of the polymer 1a, 380 g of N-methyl-2-pyrrolidone, 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and an imidization reaction was performed at 120 ° C. for 4 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. Thereafter, it was washed with methanol and dried under reduced pressure for 15 hours to obtain 29 g of an imidized polymer (hereinafter referred to as “polymer 1b”).

Synthesis example 2
Polymerization of polyamic acid 1- (2,3-difluoro-4- (4-n-hexylcyclohexyl) phenoxy) -2,4-diaminobenzene In place of 0.1 mol (40.1 g), (2,3- In the same manner as in Synthesis Example 1 except that 0.1 mol (43.1 g) of dicyano-4- (4-n-pentylcyclohexyl) phenyl) -3,5-diaminobenzoate was used, polyamic acid (hereinafter referred to as “heavy” 64 g) was obtained.
In place of 31.2 g of polymer 1a in the imidation reaction, 30 g of imidized polymer (hereinafter referred to as “polymer 2b”) was obtained in the same manner as in Synthesis Example 1 except that 32.8 g of polymer 2a was used. Obtained.

Synthesis example 3
Instead of the polymerization of the polyamic acid 1- (2,3-difluoro-4-(4-n-hexyl cyclohexyl) phenoxy) -2,4-diaminobenzene 0.1 mol (40.3 g), 1 (6 (4 In the same manner as in Synthesis Example 1 except that 0.1 mol (36.8 g) of -n-hexylcyclohexyl) -3-pyridazinyloxy) -2,4-diaminobenzene was used, polyamic acid (hereinafter, “ 57 g) of polymer 3a).
In place of 31.2 g of polymer 1a in the imidization reaction, 26 g of imidized polymer (hereinafter referred to as “polymer 3b”) was obtained in the same manner as in Synthesis Example 1 except that 29.6 g of polymer 3a was used. Obtained.

Synthesis example 4
Polymerization of polyamic acid 1,3,3a, 4,5,9b-Hexahydro-4- (6- (4-n-pentylcyclohexyl) -3-pyridazinyloxy) -5- (tetrahydro-2,5- Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione (0.1 mol, 54.6 g) and p-phenylenediamine (0.1 mol, 10.8 g) were mixed with N-methyl. 2-Pyrrolidone was dissolved in 300 g and reacted at 60 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. Then, it wash | cleaned with methanol, and it was made to dry at 40 degreeC under pressure reduction for 15 hours, and obtained 64 g of polyamic acids (henceforth "the polymer 4a").
In place of 31.2 g of polymer 1a in the imidation reaction, 26 g of imidized polymer (hereinafter referred to as “polymer 4b”) was obtained in the same manner as in Synthesis Example 1 except that 32.7 g of polymer 4a was used. Obtained.

Comparative Synthesis Example 1
Polymerization of polyamic acid 0.1 mol (22.4 g) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 0.1 mol (10.8 g) of p-phenylenediamine were added to 300 g of N-methyl-2-pyrrolidone. It was dissolved and reacted at 60 ° C. for 6 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. Then, it wash | cleaned with methanol and it was made to dry at 40 degreeC under pressure reduction for 15 hours, and 27 g of polyamic acids (henceforth "polymer Aa") were obtained.
Imidization reaction To 16.6 g of the polymer Aa, 380 g of N-methyl-2-pyrrolidone, 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and an imidization reaction was performed at 120 ° C. for 4 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. Thereafter, it was washed with methanol and dried under reduced pressure for 15 hours to obtain 13 g of an imidized polymer (hereinafter referred to as “polymer Ab”).

Example 1
(1) Preparation of liquid crystal aligning agent:
The polymer (1) obtained in Synthesis Example 1 is dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 2.5% by weight, and this solution is filtered through a filter having a pore size of 1 μm to obtain the liquid crystal aligning agent of the present invention. Prepared.
(2) Production of liquid crystal display element:
1) The liquid crystal aligning agent of the present invention prepared as described above 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. By drying for a time, a coating film having a dry film thickness of 800 Å was formed.
2) The liquid crystal alignment film was produced by performing the rubbing process on the formed coating film surface using a rubbing machine having a roll wound with a nylon cloth. Here, the rubbing treatment conditions were a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / second.
3) Two substrates on which the liquid crystal alignment film was formed as described above were produced, and an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 17 μm was applied to the outer edge of each substrate by screen printing. Thereafter, the two substrates were placed facing each other through a gap so that the rubbing directions in the respective liquid crystal alignment films were antiparallel to each other, the outer edges were brought into contact with each other, and the adhesive was cured.
4) Inject and fill nematic liquid crystal “MLC-6608” (Merck) into the cell gap defined by the adhesive on the surface and outer edge of the substrate, and then seal the injection hole with epoxy adhesive Thus, a liquid crystal cell was constructed. Thereafter, a polarizing plate was bonded to the outer surface of the liquid crystal cell so that the polarization direction was at an angle of 45 degrees with the rubbing direction of the liquid crystal alignment film and was orthogonal to each other, thereby producing a liquid crystal display element.
5) The liquid crystal display element manufactured as described above had a liquid crystal pretilt angle of 89 degrees. Further, when a voltage was applied to and released from the liquid crystal cell, no abnormal domain was observed, and the alignment of the liquid crystal was good.
Examples 2-4
A liquid crystal display device was produced in the same manner as in Example 1 except that the polymers (2b) to (4b) obtained in Synthesis Examples 2 to 4 were used in place of the polymer (1b). In the produced liquid crystal cell, the orientation and pretilt angle of the liquid crystal were evaluated. The results are shown in Table 1.

Example 5
A liquid crystal display device was produced in the same manner as in Example 1 except that the polymer (4a) obtained in Synthesis Examples 2 to 4 was used instead of the polymer (1b). In the produced liquid crystal cell, the orientation and pretilt angle of the liquid crystal were evaluated. The results are shown in Table 1.

Comparative Example A liquid crystal display device was produced in the same manner as in Example 1 except that the polymer (Ab) obtained in Comparative Synthesis Example 1 was used instead of the polymer (1b). In the manufactured liquid crystal display element, the pretilt angle of the liquid crystal was 1 degree or less and was not vertically aligned.

Claims (4)

A liquid crystal alignment comprising a polymer having a side chain having at least one structure selected from the group consisting of a structure represented by the following formula (I) and a structure represented by the following formula (II): Agent.

(In the formula, A ¹ and B ¹ are each independently a hydrogen atom, a halogen atom or a cyano group, provided that at least one of A ¹ and B ¹ is a halogen atom or a cyano group. .)

The polymer is a group represented by the following formula (III):

(Wherein P is a single bond, —O—, —COO— or —CONH—, Q is a structure represented by the above formula (I) or a structure represented by the above formula (II), R ¹ is a divalent alicyclic group and R ² is a linear alkyl group having 1 to 22 carbon atoms.)
The liquid crystal aligning agent of Claim 1 which is a polymer which has as a side chain. The liquid crystal aligning agent of Claim 1 or 2 in which a polymer has a polyamic acid structure and / or a polyimide structure in the principal chain. A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.