JP2009251439A - Vertical alignment type liquid crystal alignment film and vertical alignment type display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical alignment type liquid crystal alignment agent which achieves compatibility between excellent coatability, and excellent vertical alignment properties of a formed liquid crystal alignment film. <P>SOLUTION: The vertical alignment type alignment agent contains at least one polymer selected from a group of polyamic acids and imidized polymers thereof, the polyamic acids being each obtained by allowing a tetracarboxylic acid dianhydride to react with diamine containing a specific compound represented by a compound shown by formula (A) (wherein X is a single-bond, -CO- or methylene group, and R is a group based on γ-orizanol). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vertical alignment type liquid crystal alignment film and a vertical alignment type liquid crystal display element.

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 a 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. TN type liquid crystal display elements having so-called TN type (Twisted Nematic) liquid crystal cells and STN (Super Twisted Nematic) type liquid crystal display elements capable of realizing a high contrast ratio as compared with TN type liquid crystal display elements (Patent Documents 1 and 2) ), IPS (In-Plane Switching) type liquid crystal display element (Patent Document 3), VA an optical alignment type liquid crystal display element (Patent Documents 4 and 5), and an optical compensation bend (OCB) type liquid crystal display element (Patent Documents 6 and 7) having a small viewing angle dependency and excellent high-speed response of a video screen, respectively. Has been developed. As materials for the liquid crystal alignment film in these various liquid crystal display elements, polyimide, polyamide, polyester and the like are conventionally known. In particular, polyimide (imidized polymer) has heat resistance, affinity with liquid crystal, mechanical properties. It has excellent strength and is used in many liquid crystal display elements.
Among the liquid crystal display elements described above, the liquid crystal alignment film used in the vertical alignment type liquid crystal display element is formed by using a liquid crystal alignment agent containing a polymer having an appropriate functional group in the side chain, thereby forming liquid crystal molecules. It has been reported that good vertical alignment with respect to can be obtained. For example, Patent Document 8 contains a liquid crystal aligning agent containing an imidized polymer having a bulky alkyl group in the side chain, and Patent Document 9 contains an imidized polymer having a group containing a fluorine atom in the side chain. Liquid crystal aligning agents to be described are respectively described, and a liquid crystal aligning film formed from these liquid crystal aligning agents is said to have good vertical alignment.
However, according to these techniques, in order to impart sufficient vertical alignment to the liquid crystal alignment film to be formed, it is necessary to increase the content ratio of the functional group in the polymer contained in the liquid crystal alignment agent. As a result, the problem that the applicability | paintability of a liquid crystal aligning agent is impaired has arisen. In other words, repelling and pinholes are generated in the coating film formed from such a liquid crystal aligning agent, and there is a problem that display defects occur in the vertical alignment type liquid crystal display element produced for this purpose.
Japanese Patent No. 147434632 JP-A-1-120528 JP 2003-107486 A Japanese Patent No. 4050487 JP 2001-235748 A JP 2003-279996 A JP 2007-009031 A Japanese Patent No. 2893671 JP 2006-321783 A JP 2002-327058 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544

An object of the present invention is a vertical alignment type liquid crystal aligning agent that achieves both good coatability and good vertical alignment in the liquid crystal alignment film to be formed, and a vertical alignment type that has excellent vertical alignment and no display defects The object is to provide a liquid crystal display element.
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 as follows.
Tetracarboxylic dianhydride and the following formula (A)

(In the formula (A), X is a single bond, -CO- or a methylene group, and R is the following formula (R-1) to (R-4).

(In formulas (R-1) to (R-4), “*” represents a bond.)
It is group represented by either. )
A vertical alignment type containing at least one polymer selected from the group consisting of a polyamic acid obtained by reacting with a diamine containing one or more of the compounds represented by formula (I) and an imidized polymer thereof Achieved by a liquid crystal aligning agent, and secondly,
This is achieved by a vertical alignment type liquid crystal display device comprising a vertical alignment type liquid crystal alignment film formed from the above liquid crystal alignment agent.

The vertical alignment type liquid crystal aligning agent of the present invention has good coating properties, and the liquid crystal alignment film formed therefrom has good vertical alignment properties. The vertical alignment type liquid crystal display element of the present invention comprising a liquid crystal alignment film formed from the vertical alignment type liquid crystal alignment agent of the present invention is excellent in vertical alignment and has no display defects.
The vertical alignment type liquid crystal display element of the present invention can be effectively used in various devices, and is suitably used for display devices such as desk calculators, watches, table clocks, counting display boards, word processors, personal computers, and liquid crystal televisions. be able to.

The liquid crystal aligning agent of this invention is a polyamic acid obtained by making tetracarboxylic dianhydride and the diamine containing 1 type or 2 types or more of the compounds represented by the said Formula (A) react, and its imide Containing at least one polymer selected from the group consisting of polymerized polymers.
<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic 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-cyclopentanetetra Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-to Carboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid 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, 4,5,9b- Hexahydro-7-methyl-5- (te Torahydro-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, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxa Bicyclo [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 Tricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, the following formulas (TI) and (T-II)

(In the formulas (T-I) and (T-II), R ¹ and R ³ each represent a divalent organic group having an aromatic ring, and R ² and R ⁴ each represent a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound represented by each of the following:
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, 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 (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-1) to (T-4)

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. These may be used alone or in combination of two or more.
Among the above, the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention includes butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic 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, 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 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 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, 3,3 ′, , 4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 1 , 4,5,8-Naphthalenetetracarboxylic dianhydride, among the compounds represented by the above formula (TI), the following formulas (T-5) to (T-7)

Of the compounds represented by each of the above and the compounds represented by the above formula (T-II), the following formula (T-8)

It is preferable that it contains at least one selected from the group consisting of the compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride (1)”) to exhibit good liquid crystal alignment. From the viewpoint of being able to do so. As the specific tetracarboxylic dianhydride (1), in particular, 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, 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 acid Anhydride, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane At least one selected from the group consisting of -3,5,8,10-tetraone, pyromellitic dianhydride and the compound represented by the above formula (T-5) is preferable.
The tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention is 50 mol% of the specific tetracarboxylic dianhydride (1) as described above with respect to the total tetralacarboxylic dianhydride. It is preferable that it is contained above, more preferably 75 mol% or more, and particularly preferably 80 mol% or more.

<Diamine>
The diamine used for synthesizing the polyamic acid in the present invention contains one or more of the compounds represented by the above formula (A). As the diamine used for synthesizing the polyamic acid, only the compound represented by the above formula (A) may be used, or the compound represented by the above formula (A) and another diamine may be used in combination. Also good.
In the above formula (A), the position of the two amino groups bonded to the left benzene ring with respect to X is preferably the 2,4 position when X is a single bond, and X is —CO— or a methylene group. Is preferably the 3rd and 5th positions.
As the diamine used for synthesizing the polyamic acid in the present invention, in the above formula (A), the kind of X and the substitution position of two amino groups are the same, and R is (R-1) to (R), respectively. It is preferable from the point of the ease of a synthesis | combination to contain the diamine mixture which consists of 4 types of compounds which are -4). In this case, the preferable mixing ratio of the compounds in which R is (R-1) to (R-4) in the formula (A) is as follows with respect to the total of the compounds represented by the formula (A). It is as follows.
Compound in which R is (R-1): preferably 5 to 50 mol%, more preferably 10 to 45 mol%
Compound in which R is (R-2): preferably 5 to 50 mol%, more preferably 10 to 45 mol%
Compound in which R is (R-3): preferably 10 to 60 mol%, more preferably 15 to 50 mol%
Compound in which R is (R-4): preferably 1 to 30 mol%, more preferably 5 to 25 mol%
Examples of the compound represented by the above formula (A) include the following formula (B):

(In the formula (B), X has the same meaning as in the above formula (A), and R 'represents the following formulas (R'-1) to (R'-7).

(In formulas (R′-1) to (R′-7), “*” represents a bond).
It is group represented by either. )
It can synthesize | combine by hydrogenating the compound represented by these.
The compound represented by the above formula (B) is synthesized as follows using, for example, the compound R′—OH (where R ′ has the same meaning as in the above formula (B)). be able to.
In the above formula (B), the compound in which X is a single bond is a compound R′—OH and dinitrohalobenzene, preferably in the presence of an organic basic catalyst such as potassium carbonate, sodium ethoxide, potassium t-butoxide and the like. It can obtain by making it react. The compound in which X is —CO— in the above formula (B) can be obtained by converting dinitrobenzoic acid into an acid chloride with, for example, thionyl chloride, and then esterifying by reaction with compound R′—OH. The compound in which X is a methylene group in the above formula (B) can be obtained by reacting compound R′—OH with dinitrobenzyl halide, preferably in the presence of an organic base catalyst such as potassium carbonate.
The hydrogenation reaction of the compound represented by the above formula (B) thus obtained can be carried out by a known method, for example, using a known hydrogenation catalyst such as palladium / carbon, iron (III) chloride, platinum or the like and hydrogen gas. Catalytic hydrogenation can be used. This catalytic hydrogenation can be carried out in a solvent, and as the solvent, for example, methanol, ethanol, isopropanol, ethyl acetate, 1,4-dioxane, toluene and the like can be used. The pressure of hydrogen in the catalytic hydrogenation is preferably 0.1 to 20 MPa, more preferably 0.1 to 10 MPa. The reaction temperature during the catalytic hydrogenation is preferably −15 to 130 ° C., and the reaction time is preferably 3 hours to 2 days.
Here, as the compound R′-OH, natural γ-oryzanol, which is a mixture of seven types of compounds in which R ′ is a group represented by the above formulas (R′-1) to (R′-7), respectively. By using this, it is possible to obtain a diamine mixture containing the above four compounds of the formula (A), each of R being (R-1) to (R-4), in the above-mentioned preferred mixing ratio by a simple method. It is possible and preferable.

  In synthesizing the polyamic acid in the present invention, other diamines that can be used in combination with the compound represented by the above formula (A) include, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane. 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenz Anilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-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'-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, 4,4'-bis (4-aminophenoxy) bi Enyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diamino Fluorene, 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′-diaminobiphenyl 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-a Mino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-tri Aromatic diamines such as fluoromethyl) phenoxy] -octafluorobiphenyl;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic or cycloaliphatic diamines such as 1,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane;
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 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'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N '-Dimethyl-benzidine and the following formula (DI)

(In the formula (DI), R ⁵ 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. .)
A compound represented by formula (D-II):

(In Formula (D-II), R ⁶ 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, respectively. And a plurality of X ² may be the same or different.)
A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in a molecule such as a compound represented by:
The following formula (D-III)

(In the formula (D-III), R ⁷ represents a divalent linking group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁸ represents a steroid. (A monovalent organic group having a group selected from a skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group, or an alkyl group having 6 to 30 carbon atoms.)
Monosubstituted phenylenediamines such as compounds represented by:
The following formula (D-IV)

(In the formula (D-IV), each R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ may be the same or different, and p is each 1 is an integer of 1 to 3, and q is an integer of 1 to 20.)
Diaminoorganosiloxanes such as compounds represented by:
The following formulas (D-1) to (D-5)

(Y in the formula (D-4) is an integer of 2 to 12, and z in the formula (D-5) is an integer of 1 to 5.)
The compound etc. which are represented by these can be mentioned. These can be used alone or in combination of two or more.
Other diamines that can be used for synthesizing the polyamic acid in the present invention are p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diamino, among the above. Naphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 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-phenylenediiso (Ropyridene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 1,4- Diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, compounds represented by the above formulas (D-1) to (D-5), 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′-bis (4-aminophenyl) -ben Jin, N, N'-bis (4-aminophenyl) -N, N'-dimethyl-benzidine, formula of the compound represented by the above formula (D-I) (D-6)

Of the compounds represented by formula (D-II), the following formula (D-7)

Of the compounds represented by formula (D-III), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, the following formula (D-8) ~ (D-16)

And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane (hereinafter referred to as the compound represented by the formula (D-IV)) , “Other specific diamine”).
The diamine used for synthesizing the polyamic acid in the present invention contains 3 to 50 mol% of one or more of the compounds represented by the formula (A) with respect to the total diamine. It is more preferable that it is contained in an amount of 3 to 40 mol%, more preferably 4 to 40 mol%.
The diamine used for synthesizing the polyamic acid in the present invention preferably contains 30 to 95 mol%, and 40 to 90 mol% of the other specific diamine as described above with respect to the total diamine. More preferably, it is more preferably 50 to 90 mol%.

<Synthesis of polyamic acid>
The polyamic acid in the present invention can be synthesized by reacting the tetracarboxylic dianhydride as described above with a diamine.
The proportion of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is such that the acid anhydride group of tetracarboxylic dianhydride is 0.5 to 1 equivalent to 1 equivalent of amino group contained in the diamine. A ratio of 2 equivalents is preferable, and a ratio of 0.7 to 1.2 equivalents is more preferable.
The polyamic acid synthesis reaction is preferably carried out in an organic solvent under a temperature condition of preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably 1 to 30 hours, more preferably 2 to 5 hours. The organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ- Examples include aprotic polar solvents such as butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of the organic solvent used (a) is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight with respect to the total amount (a + b) of the reaction solution. It is preferable that In addition, when using the below-mentioned poor solvent together with an organic solvent, the usage-amount of said organic solvent should be understood as a total amount of an organic solvent and a poor solvent.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, 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- Chill 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, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
When the organic solvent and the poor solvent are used in combination, the amount of the poor solvent used is preferably 70% by weight or less, more preferably 60% by weight or less, based on the total of the organic solvent and the poor solvent. Furthermore, it is preferable that it is 50 weight% or less.

  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. 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 evaporating under reduced pressure with an evaporator once or several times.

<Imidized polymer>
The imidized polymer in the present invention can be obtained by dehydrating and ring-closing and imidizing a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine.
Examples of the tetracarboxylic dianhydride used for the synthesis of the imidized polymer in the present invention include the same compounds as the tetracarboxylic dianhydride used for the synthesis of the polyamic acid described above.
The tetracarboxylic dianhydride used for the synthesis of the imidized polymer in the present invention is at least one selected from alicyclic tetracarboxylic dianhydrides (hereinafter referred to as “specific tetracarboxylic dianhydride (2)”. "). Specific tetracarboxylic dianhydrides include 2,3,5-tricarboxycyclopentyl acetic 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'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy- 2-carboxynorbornane 2: 3,5: is selected from 6-dianhydride and 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} the group consisting of undecanoic -3,5,8,10- tetraone At least one is preferred.
The tetracarboxylic dianhydride used for synthesizing the imidized polymer in the present invention is obtained by changing the specific tetracarboxylic dianhydride (2) as described above to 50% of the total tetralacarboxylic dianhydride. It is preferable to contain more than mol%, more preferably more than 75 mol%, particularly preferably more than 80 mol%.
The diamine used for the synthesis of the imidized polymer in the present invention is the same as the diamine used for the synthesis of the polyamic acid described above. The preferred diamine and its preferred use ratio are the same as in the case of the synthesis of the polyamic acid.

The imidized polymer in the present invention can be obtained by dehydrating and ring-closing polyamic acid to imidize.
The imidized polymer may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure that the polyamic acid as a raw material had, and by dehydrating and cyclizing only a part of the amic acid structure, And a partially imidized product in which an imide ring structure coexists. The imidized polymer contained in the liquid crystal aligning agent of the present invention preferably has an imidation rate of 30% or more, and particularly preferably 50% or more.
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 (i) of heating the polyamic acid 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 1 to 24 hours, more preferably 2 to 10 hours.
In the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. . The amount of the dehydrating agent used is preferably 0.01 to 20 mol relative to 1 mol of the polyamic acid repeating unit. 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. 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. The reaction time is preferably 1 to 10 hours, more preferably 2 to 6 hours.

  The imidized polymer obtained in the above method (i) may be used for the preparation of a liquid crystal aligning agent as it is, or may be used for the preparation of a liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (ii), a reaction solution containing an imidized polymer is obtained. This reaction solution 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. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a 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 described above as the method for isolating and purifying the polyamic acid.

-End-modified polymer-
The polyamic acid or the imidized polymer thereof that can be contained in the liquid crystal aligning agent of the present invention may be of a terminal modified type with a controlled molecular weight. By using the terminal-modified polymer, the coating properties of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention. Such a terminal-modified polymer can be obtained by adding a molecular weight modifier to a polymerization reaction system when synthesizing a polyamic acid. Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like.
Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n -Hexadecyl succinic anhydride etc. can be mentioned. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. it can. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight regulator is preferably 8 parts by weight or less, more preferably 4 parts by weight or less, with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. is there.
-Solution viscosity-
The polyamic acid or imidized polymer obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, when it is made into a solution having a concentration of 10% by weight, and preferably has a solution viscosity of 30 to 500 mPa · s. More preferably, it has a solution viscosity.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other ingredients>
The vertical alignment type liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of the polyamic acid and its imidized polymer as an essential component, but the effects and advantages of the present invention are not limited. Other components may be contained as long as they are not impaired. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.
Examples of the other polymer include polyamic acid obtained by reacting, for example, polyorganosiloxane, tetracarboxylic dianhydride and a diamine not containing the compound represented by the above formula (A) (hereinafter referred to as “other polyamic acid”). Acid ") and imidized polymers thereof (hereinafter referred to as" other imidized polymers "), polyamic acid esters, polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives. And poly (meth) acrylate. Among these, other polyamic acids or other imidized polymers are preferable from the viewpoint of excellent varnish properties and electrical characteristics, and other polyamic acids are more preferable.
The proportion of the other polymer used in the vertical alignment type liquid crystal aligning agent of the present invention is the sum of the polymers (one or two or more of the compounds represented by tetracarboxylic dianhydride and the above formula (A)). Is the total of the polyamic acid obtained by reacting with a diamine containing, and its imidized polymer and other polymers, the same shall apply hereinafter), and preferably 90% by weight or less, more preferably 85% by weight. % Or less, and more preferably 80% by weight or less.

  The said epoxy compound can be contained in the vertical alignment type liquid crystal aligning agent of this invention from a viewpoint of improving the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed. Examples of such epoxy compounds 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 ′ Diaminodiphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - such as aminomethyl cyclohexane may be mentioned as preferred. The use ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, 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 ( Examples thereof include oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
The use ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less, with respect to 100 parts by weight of the total polymer.

<Vertical alignment type liquid crystal alignment agent>
The vertical alignment type liquid crystal aligning agent of the present invention is constituted by dissolving the polymer as described above and other components optionally added, preferably dissolved in an organic solvent.
As an organic solvent which can be used for 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. Here, the poor solvent illustrated as what can be used together in the synthesis reaction of a polyamic acid may also be selected suitably, and may be used together.
Preferable specific examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethyl. Acetamide, 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, di Examples include ethylene 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, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in admixture of two or more. A particularly preferable solvent composition is a composition obtained by combining two or more selected from the above-mentioned solvents, in which a polymer or the like does not precipitate in the vertical liquid crystal aligning agent, and the surface of the vertical liquid crystal aligning agent The composition is such that the tension is in the range of 25 to 40 mN / m.

The solid content concentration in the vertical alignment type liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately determined in consideration of viscosity, volatility, and the like. Although selected, it is preferably in the range of 1 to 10% by weight. That is, the vertical liquid crystal aligning agent of the present invention is applied to the substrate surface, and then the solvent is removed to form a coating film that becomes a liquid crystal aligning film. However, the solid content concentration is less than 1% by weight. In some cases, the film thickness of this coating film becomes too small, making it difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film is Similarly, it may become difficult to obtain a good liquid crystal alignment film, and 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 is in the range of 12 to 50 mPa · s. In the case of the ink jet 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 is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 100 ° C, more preferably 20 ° C to 60 ° C.

<Vertical alignment type liquid crystal display element>
The vertical alignment type liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention as described above.
The vertical alignment type liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) The vertical alignment type 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 appropriate application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. Then, the coated surface is formed by heating the coated surface to remove the solvent. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, alicyclic polyolefin, or the like 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. Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, using a photomask having a desired pattern when forming the transparent conductive film For example, a method of directly forming a patterned transparent conductive film can be used. Prior to application of the liquid crystal aligning agent, a functional silane compound, a functional titanium compound, or the like may be applied in advance to the substrate surface in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film. Good. In order to improve the viewing angle characteristics, a liquid crystal aligning agent is applied after forming a projecting structure as described in Patent Document 10 (Japanese Patent Laid-Open No. 2002-327058) on a substrate. Also good.

After application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-bake temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 30 seconds to 10 minutes, more preferably 1 to 5 minutes. Thereafter, a firing (post-bake) step is performed for the purpose of completely removing the solvent. This post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 10 to 90 minutes, more preferably 15 to 70 minutes.
The vertical alignment type liquid crystal aligning agent of the present invention forms a coating film to be a liquid crystal alignment film by removing the organic solvent after coating in this way, but the vertical alignment type liquid crystal aligning agent of the present invention is polyamic acid or In the case of containing an imidized polymer having both an amic acid structure and an imide ring, the coating film may be further imidized by further dehydrating and closing the amic acid structure by further heating.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) The coating film formed as described above can be applied as it is as a liquid crystal alignment film of a vertical alignment type liquid crystal display element. It may be used as an alignment film. The rubbing treatment can be performed by rubbing in a certain direction with a roll wound with a cloth made of appropriate fibers such as nylon, rayon, and cotton. Here, for the coating film after the rubbing treatment, for example, a liquid crystal alignment film as shown in Patent Document 11 (JP-A-6-222366) or Patent Document 12 (JP-A-6-281937). A process of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating ultraviolet rays to the part, or a surface of the liquid crystal alignment film as shown in Patent Document 13 (Japanese Patent Laid-Open No. 5-107544). By forming a resist film on the part and performing a rubbing process in a direction different from the previous rubbing process, and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities in each region It is possible to improve the visibility characteristics of the obtained liquid crystal display element.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates opposed to each other. Here, when the rubbing process is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions of the coating films are at a predetermined angle.
In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooled to room temperature. It is desirable to remove.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.
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. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral products such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) Agent: 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.

The γ-oryzanol used in the following synthesis examples is a commercial product derived from natural rice bran (manufactured by Wako Pure Chemical Industries, Ltd.), and the R ′ group in R′—OH represents the above formula (R′-1). ) To (R′-7).
The polymer solution viscosity in the following synthesis examples is a value measured at 25 ° C. using an E-type viscometer for each of the polymer solutions indicated in each synthesis example.
The imidation rate of the imidized polymer was determined from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference substance after the imidized polymer was sufficiently dried at room temperature under reduced pressure and then dissolved in deuterated dimethyl sulfoxide. The following formula (i).

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

(In Formula (i), A ¹ is the peak area derived from proton of NH group appearing in the vicinity of the chemical shift 10 ppm, A ² is the peak area derived from other protons, alpha precursor (polyamic acid polymer The number ratio of other protons to one proton of NH group in)

<Synthesis of Compound Represented by Formula (A)>
Synthesis example 1
Into a 1 L reactor equipped with a dropping funnel, 60 g of γ-oryzanol and 25 g of 3,5-dinitrobenzoyl chloride were charged, and after deaeration, nitrogen substitution was performed three times. Tetrahydrofuran (THF) (400 mL) was added thereto, and the mixture was cooled with an ice bath while stirring, 16 g of pyridine was added from a dropping funnel, stirred for 1 hour, returned to room temperature, and further stirred for 12 hours.
Subsequently, THF was distilled off by an evaporator, and then 400 mL of chloroform was added to the residue to obtain an organic layer. This organic layer was washed successively with 400 mL of ultrapure water and 400 mL of saturated saline, and then concentrated using an evaporator to obtain a viscous yellow liquid. By recrystallizing this from 1 L of ethanol, in the above formula (B), X is —CO—, the bonding positions of the two nitro groups to X are the 3 and 5 positions, and R ′ is the formula (R ′ -1) to (R'-7) 78 g of a mixture comprising a compound which is a group represented by each was obtained as a yellow powder.
Next, 15.3 g of the mixture of this compound was charged into a 190 mL pressure vessel, palladium / carbon 6.6 g and 99 wt% ethanol 50 mL were added, and a hydrogenation reaction was performed at 70 ° C. under a hydrogen pressure of 1 MPa for 48 hours. . After completion of the reaction, the reaction mixture was filtered, and the filtrate was allowed to cool to obtain pale yellow crystals. The crystals are collected by filtration and dried under reduced pressure. In the above formula (A), X is —CO—, the bonding positions of the two amino groups to X are the 3 and 5 positions, and R is the above formula. 12 g of a diamine mixture (hereinafter referred to as “compound (A-1)”) composed of a compound which is a group represented by each of (R-1) to (R-4) was obtained.

Synthesis example 2
In Synthesis Example 1, 24 g of 2,4-dinitrochlorobenzene was used instead of 3,5-dinitrobenzoic acid chloride, and 32 g of potassium carbonate and 0.2 g of tetrabutylammonium bromide were used instead of pyridine. By carrying out the reaction under the same conditions as in Synthesis Example 1, in the above formula (A), X is a single bond, the bonding positions of two amino groups to X are the 2 and 4 positions, and R is the above formula (R A diamine mixture (hereinafter referred to as “compound (A-2)”) 11 g comprising a compound which is a group represented by each of (-1) to (R-4) was obtained.
Synthesis example 3
The same procedure as in Synthesis Example 2 was performed except that 22 g of 3,5-dinitrobenzyl chloride was used in place of 2,4-dinitrochlorobenzene in Synthesis Example 2, whereby X in the formula (A) was methylene. A diamine mixture comprising a group, a bonding position of two amino groups to X at positions 3 and 5, and R being a group represented by each of the above formulas (R-1) to (R-4) (Hereinafter referred to as “compound (A-3)”) 12 g was obtained.

<Synthesis of imidized polymer>
Synthesis example 4
1,1.0 g (0.050 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 4.9 g (0.045 mol) of p-phenylenediamine as diamine and Synthesis Example 1 3.7 g (0.005 mol) of the compound (A-1) obtained in the above was dissolved in 78 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 4 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 50 mPa · s.
Next, 180 g of NMP was added to the obtained polyamic acid solution, and 4.0 g of pyridine (1.0 times the number of polyamic acid amic acid structures) and 5.1 g of acetic anhydride (of polyamic acid amic acid structures). 1.0 times the number of moles) was added and dehydration ring closure was carried out at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP (in this operation, pyridine and acetic anhydride used in the dehydration cyclization reaction were removed from the system), and an imidization weight of about 49% imidization rate. About 122 g of a solution containing 15% by weight of union (PI-1) was obtained. A small amount of this solution was collected, and NMP was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 41 mPa · s.
Synthesis Examples 5-10, Comparative Synthesis Examples 1-3
In Synthesis Example 4, the types and amounts of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis and the amounts of pyridine and acetic anhydride used in the dehydration ring-closing reaction are as shown in Table 1, respectively. In the same manner as in Synthesis Example 4 above, a polyamic acid solution was obtained, and this was subjected to dehydration and cyclization, whereby imidized polymers (PI-2) to (PI-7) and comparative imidized polymers ( A solution containing pi-1) to (pi-3) was obtained. Table 1 shows the solution viscosity and the imidization ratio of the imidized polymer when diluted to 10% by weight with NMP for each polyamic acid solution and imidized polymer solution.

In addition, the amount of pyridine and acetic anhydride in Table 1 is shown as a number representing how many moles it corresponds to the number of amic acid structures of the polyamic acid.
Abbreviations of tetracarboxylic dianhydride and diamine in Table 1 have the following meanings, respectively.
[Tetracarboxylic dianhydride]
t-1: 2,3,5-tricarboxycyclopentylacetic acid dianhydride t-2: 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] furan-1,3-dione [diamine]
Compound represented by formula (A) A-1: Compound (A-1) obtained in Synthesis Example 1
A-2: Compound (A-2) obtained in Synthesis Example 1 above
A-3: Compound (A-3) obtained in Synthesis Example 1
Other diamines d-1: Compounds represented by the above formula (D-10) d-2: p-phenylenediamine d-3: 4,4′-diaminodiphenylmethane <Synthesis examples of other polymers>
Synthesis Example 11
20 g (0.10 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 20 g (0.10 mol) of 4,4′-diaminodiphenyl ether as diamine were added to N-methyl. After dissolving in a mixed solvent consisting of 23 g of 2-pyrrolidone and 205 g of γ-butyrolactone and reacting at 40 ° C. for 4 hours, 130 g of γ-butyrolactone was added to thereby add 10% by weight of polyamic acid (pa-1). About 400 g of the contained solution was obtained. The solution viscosity of this polyamic acid solution was 210 mPa · s.
Synthesis Example 12
20.0 g (0.10 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine. 0 g (0.10 mol) was dissolved in a mixed solvent consisting of 37 g of N-methyl-2-pyrrolidone and 330 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours, so that 10 weight of polyamic acid (pa-2) was obtained. About 400 g of a solution containing% was obtained. The solution viscosity of this polyamic acid solution was 160 mPa · s.

Example 1
<Adjustment of vertical alignment type liquid crystal alignment agent>
The amount corresponding to 100 parts by weight of the solution containing the imidized polymer (PI-1) obtained in Synthesis Example 4 in terms of the imidized polymer (PI-1) contained in the summary solution To this, 20 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane as an epoxy compound is added, and N-methyl-2-pyrrolidone and butyl cellosolve are added to obtain a solvent composition. N-methyl-2-pyrrolidone: butyl cellosolve = 50: 50 (weight ratio), a solid content concentration of 5% by weight, and this solution is filtered using a filter having a pore size of 1 μm to obtain a vertical alignment type liquid crystal aligning agent. Was prepared.
<Formation of liquid crystal alignment film and evaluation of applicability>
About the liquid crystal aligning agent prepared above, it apply | coats to the transparent electrode surface of the glass substrate with a transparent electrode which consists of an ITO film | membrane using a liquid crystal aligning film printer (Nissha Printing Co., Ltd.), on a 80 degreeC hotplate. After pre-baking for 1 minute, it was post-baked on a hot plate at 200 ° C. for 10 minutes to form a coating film (liquid crystal alignment film) having an average film thickness of 1,000 mm on the transparent electrode surface of the substrate. When these coating films were observed with a microscope having a magnification of 20 times, printing unevenness and pinholes were not observed, and the printability was good.
The same operation was repeated to manufacture a pair (two) of substrates having a liquid crystal alignment film on the transparent electrode surface.
<Production of vertical alignment type liquid crystal cell and evaluation of vertical alignment>
After applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of substrate coatings, the adhesive is cured by overlapping and bonding so that the liquid crystal alignment film faces each other. did. Next, a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled into the gap between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, thereby obtaining a vertical alignment type. A liquid crystal cell was manufactured.
This vertically aligned liquid crystal cell was placed on a polarizing microscope (vertical polarizing plate 90 ° crossing arrangement, microscope magnification 20 times), and the transmitted light intensity was measured without applying a voltage. When this transmitted light intensity is compared with the intensity of light that has passed through only two polarizing plates arranged in parallel with each other, the vertical alignment is “good” when the other value is less than 2%. When the vertical alignment property was evaluated as “bad”, the vertical alignment property of the vertical alignment type liquid crystal cell was “good”.

Examples 2-12 and Comparative Examples 1-3
In Example 1 above, the types and amounts of the polymer and epoxy compound contained in the polymer solution used were the same as in Example 1 except that Table 2 and the solvent composition were as shown in Table 2, respectively. Similarly, a vertical alignment type liquid crystal aligning agent was prepared and evaluated. The evaluation results are shown in Table 2.

Each polymer in Table 2 is used for the preparation of a vertical liquid crystal aligning agent as a polymer solution, and the amount of weight in Table 2 is a value converted to the amount of polymer contained in the polymer solution used. .
The abbreviations of the epoxy compound and the solvent in Table 2 have the following meanings, respectively.
<Epoxy compound>
E-1: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane E-2: N, N, N ′, N′-tetraglycidyl-m-xylylenediamine E-3: N, N-diglycidyl-aminomethylcyclohexane <solvent>
NMP: N-methyl-2-pyrrolidone BL: γ-butyrolactone BC: butyl cellosolve In Comparative Example 1, 10 or more pinholes were confirmed within a range of 0.5 mm × 0.5 mm. Judged as “bad”.

Claims (5)

Tetracarboxylic dianhydride and the following formula (A)

(In the formula (A), X is a single bond, -CO- or a methylene group, and R is the following formula (R-1) to (R-4).

(In formulas (R-1) to (R-4), “*” represents a bond.)
It is group represented by either. )
It contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting with a diamine containing one or more of the compounds represented by formula (I) and an imidized polymer thereof. A vertical alignment type liquid crystal aligning agent.   The vertical alignment liquid crystal aligning agent of Claim 1 whose ratio of the compound represented by the said Formula (A) in the said diamine is 3-40 mol%.   In the above formula (A), the positions of the two amino groups bonded to the left benzene ring to X are the 2 and 4 positions when X is a single bond, and 3 when X is —CO— or a methylene group. The vertically aligned liquid crystal aligning agent according to claim 1, which is in the 5th position.   One or more of the compounds represented by the above formula (A) in the diamine are reacted with γ-oryzanol and dinitrohalobenzene, dinitrobenzoic acid halide or dinitrobenzyl halide, and then the reaction product The vertical alignment liquid crystal aligning agent as described in any one of Claims 1-3 which is a diamine mixture obtained by hydrogenating a thing.   A vertical alignment type liquid crystal display device comprising a vertical alignment type liquid crystal alignment film formed from the liquid crystal alignment agent according to claim 1.