JP2010097188A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

で表される化合物に代表される特定の化合物を含有する。上記液晶表示素子は、上記の液晶配向剤から形成された液晶配向膜を具備する。
【選択図】なしDisclosed are a liquid crystal aligning agent in which a high voltage holding ratio, a good vertical alignment property and a good printability are compatible, and a liquid crystal display element showing a good vertical alignment property and a high voltage holding ratio.
The liquid crystal aligning agent includes (A) at least one polymer selected from the group consisting of polyamic acid and polyimide, and the following formula (B-3-2-2-1):

The specific compound represented by the compound represented by these is contained. The liquid crystal display element includes a liquid crystal alignment film formed from the liquid crystal alignment agent.
[Selection figure] None

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element.

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 was formed into a sandwich cell, and the major axis of the liquid crystal molecules was continuously twisted by 90 ° 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 known. In addition, an STN (Super Twisted Nematic) type liquid crystal display element has been developed that has a higher contrast than the TN type liquid crystal display element and has less viewing angle dependency. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of the liquid crystal molecules is continuously twisted over 180 ° between the substrates. The birefringence effect produced by the above is utilized.
In recent years, the development of new liquid crystal display elements has been active, and as one of them, as disclosed in Patent Document 1, two electrodes for driving a liquid crystal are arranged in a comb-like shape on a substrate on one side. A lateral electric field type liquid crystal display element that generates an electric field parallel to the substrate surface and controls liquid crystal molecules has been proposed. This element is generally called an in-plane switching type (IPS type) and is known to have excellent viewing angle characteristics.
On the other hand, as a liquid crystal display element having a function different from the above, it is called an MVA (Multi domain Vertical Alignment) method or a PVA (Patterned Vertical Alignment) method in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate. A vertical alignment type liquid crystal display element has been proposed. These MVA type and PVA type vertical alignment type liquid crystal display elements are excellent not only in viewing angle and contrast, but also in terms of manufacturing processes, such as not having to perform a rubbing treatment in forming a liquid crystal alignment film.

The ability to align liquid crystal molecules perpendicularly to the substrate (vertical alignment) is known to be manifested by using a polymer having a bulky substituent in the side chain as the material of the liquid crystal alignment film. It has been proposed to use a monomer having a bulky substituent (a monomer having a pretilt angle) during the synthesis of the polymer. For example, Patent Document 2 proposes a method using a polymer obtained by using 1-octadecyloxy-2,4-diaminobenzene as a pretilt angle-expressing monomer. Similarly, Patent Documents 3 and 4 include cholesteryl-3,5-diaminobenzoate, stearyl lithocholic acid (3,5-diaminobenzoate), cholestanyl-3,5-diaminobenzoate, and the like as pretilt angle-expressing monomers. Patent Document 5 describes cholesteryloxy-2,4-diaminobenzene and the like. By using a polymer synthesized using a large amount of these pretilt angle-expressing monomers as the liquid crystal alignment film, a liquid crystal aligning agent exhibiting stable vertical alignment can be obtained.
By the way, from the standpoint of increasing the panel size in recent years and improving the yield of products, liquid crystal aligning agents are required to have a high voltage holding ratio and a high degree of printability. However, it is known that when a polymer synthesized by using a large amount of the above-described pretilt angle-expressing monomer is used as a liquid crystal aligning agent, the printability is particularly deteriorated. It is believed that printability is in a trade-off relationship.
Thus, a liquid crystal aligning agent that has both a high voltage holding ratio and good vertical alignment properties and good printability is awaited.

Japanese Patent Laid-Open No. 7-261181 JP-A-6-136122 Japanese Patent No. 2893671 JP 2004-331937 A Japanese Patent Application Laid-Open No. 2004-262921

An object of the present invention is to provide a liquid crystal aligning agent in which a high voltage holding ratio and good vertical alignment properties and good printability are compatible.
Another object of the present invention is to provide a liquid crystal display device exhibiting good vertical alignment and high voltage holding ratio.
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,
(A) At least one polymer selected from the group consisting of polyamic acid and polyimide, and (B) an epoxy group and the following formula (2 ⁰ )

(In the formula (2 ⁰ ), R ^I is an alkyl group having 4 to 40 carbon atoms or a fluoroalkyl group having 4 to 40 carbon atoms, or a hydrocarbon group having 17 to 51 carbon atoms having a steroid skeleton;
Z ^I represents a single ^bond, * ^-O-, a * -COO- or ^* -OCO- (where bond marked with "*" is ^{R I} side.)
R ^II is a cyclohexylene group or a phenylene group,
n1 is 1 or 2,
Provided that when n1 is 2, the two R ^IIs may be the same or different from each other;
n2 is 0 or 1;
Z ^II is ^{* -O-,} a * -COO- or ^* -OCO- (where bond marked with "*" is ^{R I} side.)
n3 is an integer of 0 to 2,
n4 is 0 or 1. )
It is achieved by a liquid crystal aligning agent containing a compound having a group represented by:
The above objects and advantages of the present invention are, secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the above liquid crystal aligning agent.

The vertical alignment type liquid crystal aligning agent of the present invention is capable of forming a liquid crystal alignment film having uniform and good vertical alignment properties with almost no printing unevenness when printed on a substrate.
The liquid crystal display element of the present invention exhibits good vertical alignment and good voltage holding characteristics, and is excellent in display performance. The liquid crystal display element of the present invention can be effectively used in various devices, and can be used in display devices such as a desk calculator, a wristwatch, a table clock, a counting display board, a word processor, a personal computer, and a liquid crystal television.

The liquid crystal aligning agent of the present invention comprises (A) at least one polymer selected from the group consisting of polyamic acid and polyimide, and (B) a compound having an epoxy group and a group represented by the above formula (2 ⁰ ). (Hereinafter, also referred to as “(B) compound”.)
Containing.

<(A) Polyamic acid, polyimide>
A polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine, and a polyimide can be obtained by dehydrating and ring-closing such a polyamic acid.
[Tetracarboxylic dianhydride]
Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acid 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-cyclobutane Tetracarboxylic 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-tricarboxycyclopent Diacetic 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-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3- Dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3 -Dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1, 3-dione, 1,3,3a, 4,5,9b-hexahydro-8-eth -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-carboxy Methylnorbornane-2: 3,5: 6-dianhydride, 4 9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- tetraone the following formula (T-I) and (T-II)

(Wherein R ¹ and R ³ are each a divalent organic group having an aromatic ring, R ² and R ⁴ are each a hydrogen atom or an alkyl group, and a plurality of R ² and R ^{4 are present.} May be the same or different.)
An aliphatic tetracarboxylic dianhydride and an 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)

And aromatic tetracarboxylic dianhydrides such as compounds represented by each of the above. These may be used alone or in combination of two or more.
Examples of the compound represented by the above formula (TI) include the following (T-5) to (T-7).

As the compound represented by the above formula (T-II), for example, the following (T-8)

And the like can be mentioned respectively.
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, 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, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- ( Tetrahydro-2,5-dio So-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic acid Anhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxo Tetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, pyromellitic dianhydride, 3,3 ', 4,4'- Benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl Sulfonetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, the above formula (T-5) ˜ At least one selected from the group consisting of a compound represented by each of (T-7) and a compound represented by the above formula (T-8) (hereinafter referred to as “specific tetracarboxylic dianhydride”). It is preferable to use it from the viewpoint of exhibiting good liquid crystal orientation.

Specific tetracarboxylic dianhydrides include, in particular, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 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- No 1,2-dicarboxylic acid Things, 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 use ratio of the specific tetracarboxylic dianhydride is preferably 10 mol% or more, more preferably 20 mol% or more, and further 40 mol% or more, based on the total tetracarboxylic dianhydride. Preferably there is.
As the tetracarboxylic dianhydride used for the synthesis of the polyamic acid in the present invention, it is most preferable to use only the specific tetracarboxylic dianhydride as described above.

[Diamine]
Examples of diamines used for the synthesis of polyamic acid include 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'-diaminobenzanilide, 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'-ditrifluoro Methyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trime Luindan, 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) biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9 , 9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 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-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoro) Methyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 3,5-diaminobenzoic acid, 1,4-bis- (4-aminophenyl)- Piperazine, 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.)
An aromatic diamine such as a compound represented by each of the following:
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, Tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4,4'-methylenebis (cyclohexylamine) Aliphatic diamines such as 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, and alicyclic diamines;
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, the following formula (DI)

(In the formula (DI), R ⁵ is a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ is a divalent organic group. R ⁶ is an alkyl group having 1 to 4 carbon atoms, and a1 is an integer of 0 to 3.)
A compound represented by formula (D-II):

(In Formula (D-II), R ⁷ is a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is a divalent organic group, respectively. A plurality of X ² may be the same or different, each R ⁸ is an alkyl group having 1 to 4 carbon atoms, and a2 is an integer of 0 to 4 respectively. is there.)
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 ⁹ represents —O—, —COO— ^* , —OCO— ^* , —NHCO— ^* , —CONH— ^* (in the above, the bond indicated by “*” is R ¹⁰ is bonded to R ¹⁰ ) or —CO—, and R ¹⁰ is a monovalent organic group or carbon having a skeleton or group selected from a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group An alkyl group having 6 to 30 carbon atoms, R ¹¹ is an alkyl group having 1 to 4 carbon atoms, and a3 is an integer of 0 to 3.)
Monosubstituted phenylenediamines such as compounds represented by:
The following formula (D-IV)

(In the formula (D-IV), each R ¹² is a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹² 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.)
And diaminoorganosiloxanes such as compounds represented by the formula: These diamines can be used alone or in combination of two or more.
The benzene ring of the aromatic diamine may be substituted with one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). In the above formulas (DI), (D-II) and (D-III), R ⁶ , R ⁸ and R ¹¹ are each preferably a methyl group, and a1, a2 and a3 are each 0 Or it is preferable that it is 1, and it is more preferable that it is 0.
The monovalent organic group having R ¹⁰ steroid bone in the above formula (D-III) preferably has 17 to 51 carbon atoms, and more preferably has 17 to 30 carbon atoms. Specific examples of R ¹⁰ having such a steroid skeleton include, for example, cholestane-3-yl group, cholesta-5-en-3-yl group, cholesta-24-en-3-yl group, cholesta-5,24-diene. A -3-yl group, a lanostane-3-yl group, etc. can be mentioned.
Specific examples of the compound represented by the above formula (DI) include, for example, the following formula (D-6):

A compound represented by:
Specific examples of the compound represented by the formula (D-II) include, for example, the following formula (D-7)

A compound represented by:
Specific examples of the compound represented by the above formula (D-III) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2, 5-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene and the following formulas (D-8) to ( D-16)

The compounds represented by each of the above can be mentioned.
Among the above, the diamine used when synthesizing the polyamic acid in the liquid crystal aligning agent of the present invention is p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diamino. 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-phenylenediisopropyl Riden) 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, 3,5-diaminobenzoic acid, 1,4-bis- (4-aminophenyl) -piperazine, the above formula Compounds represented by each of (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) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, the above formula (D-6) At least one selected from the group consisting of a compound represented by formula (D-7) and 1,3-bis (3-aminopropyl) -tetramethyldisiloxane (hereinafter referred to as “specific diamine”). (1) ") and at least one selected from the group consisting of compounds represented by the above formula (D-III) (hereinafter referred to as" specific diamine (2) ").

More preferably, the specific diamine (1) is p-phenylenediamine, 4,4′-diaminodiphenylmethane, 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, 2,2-bis (4-aminophenyl) Hexafluoropropane, 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-3), , 6-diaminopyridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) ) -N, N'-dimethylbenzidine, 3,5-diaminobenzoic acid, 1,4-bis- (4-aminophenyl) -piperazine and 1,3-bis (3-aminopropyl) -tetramethyldisiloxane Is at least one selected from the group consisting of
As the specific diamine (2), more preferably, among the compounds represented by the formula (D-III), the formula (D-8), the formula (D-10), the formula (D-11), It is at least one selected from the group consisting of compounds represented by the above formula (D-14) and the above formula (D-15).
The diamine used when synthesizing the polyamic acid in the liquid crystal aligning agent of the present invention preferably contains 10 mol% or more, and 20 mol% or more of the specific diamine (1) as described above with respect to the total diamine. More preferably 40 mol% or more. Moreover, it is preferable that the diamine used when synthesize | combining the polyamic acid in the liquid crystal aligning agent of this invention contains 1-60 mol% of above specific diamine (2) with respect to all the diamine, The content is more preferably 50 mol%, and particularly preferably 8 to 40 mol%.

[Synthesis of polyamic acid]
The polyamic acid in the liquid crystal aligning agent of this invention can be obtained by making the above tetracarboxylic dianhydrides and diamine react.
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 an 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 0.2 to 120 hours, more preferably 0.5 to 72 hours. The organic solvent that can be used here 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-dimethyl Examples include aprotic polar solvents such as formamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. In addition, the amount of organic solvent used (a: in the case where an organic solvent and a poor solvent described later are used in combination) refers to the total amount of tetracarboxylic dianhydride and diamine (b). However, the amount is preferably 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc., which are generally believed to be poor solvents for polyamic acid, may be used in combination as long as the resulting polyamic acid does not precipitate. it can. Specific examples of such poor solvents include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, and 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, Lenglycol 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, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether .
When the organic solvent and the poor solvent as described above are used in combination when synthesizing the polyamic acid, the use ratio of the poor solvent is preferably 25% by weight or less, more preferably based on the total of the organic solvent and the poor solvent. Is 10% by 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.
When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.
Polyamic acid is 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 off the organic solvent in the reaction solution under reduced pressure using an evaporator. Can be performed. 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.

[Synthesis of polyimide]
The polyimide which can be contained in the liquid crystal aligning agent of this invention can be obtained by dehydrating and ring-closing and imidizing the polyamic acid obtained by making tetracarboxylic dianhydride and diamine react.
Examples of the tetracarboxylic dianhydride used when synthesizing the polyimide in the liquid crystal aligning agent of the present invention include the same compounds as those described above as the tetracarboxylic dianhydride used when synthesizing the polyamic acid. it can.
Examples of the diamine used when synthesizing the polyimide in the liquid crystal aligning agent of the present invention include the same compounds as those described above as the diamine used when synthesizing the polyamic acid. This diamine preferably contains the specific diamine (1). More preferably, the diamine used when synthesizing the polyimide in the liquid crystal aligning agent of the present invention is p-phenylenediamine, 4,4′-diaminodiphenylmethane, 3,5-diaminobenzoic acid, 1,4-bis- ( 4-Aminophenyl) -piperazine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis (aminomethyl) cyclohexane and 1,3-bis (3-aminopropyl) -tetramethyldisiloxane At least one selected from the group consisting of the following (hereinafter referred to as “specific diamine (1 ′)”) and a compound represented by the above formula (D-III) (hereinafter referred to as “specific diamine (2 ′)”). ).
The diamine used in synthesizing the polyimide in the liquid crystal aligning agent of the present invention preferably contains 10 mol% or more of the specific diamine (1 ′) as described above with respect to the total diamine, and contains 20 mol% or more. More preferably, it is preferable to contain 40 mol% or more. Moreover, it is preferable that the diamine used when synthesize | combining the polyimide in the liquid crystal aligning agent of this invention contains 1-60 mol% of above specific diamine (2 ') with respect to all the diamine, The content is more preferably 50 mol%, and particularly preferably 8 to 40 mol%.
The polyimide may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure that the polyamic acid as a raw material had, and only a part of the amic acid structure is dehydrated and ring-closed. It may be a partially imidized product having a structure. The polyimide in the liquid crystal aligning agent of the present invention preferably has an imidation ratio of 20% or more, more preferably 35 to 99%, and particularly preferably 45 to 95%. The said imidation rate represents the ratio which the number of the imide ring structure accounts with respect to the sum total of the number of the amic acid structures of polyimide, and the number of imide ring structures in percentage. At this time, a part of the imide ring may be an isoimide ring. The imidization rate can be known by ¹ H-NMR of polyimide.

Dehydration and ring closure of polyamic acid for synthesizing the polyimide can be performed by (i) heating the polyamic acid or (ii) dissolving polyamic acid in an organic solvent, and adding a dehydrating agent and a dehydrating ring closure catalyst to this solution. And it can carry out by the method of heating as needed.
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 resulting polyimide may decrease. The reaction time is preferably 0.5 to 168 hours, more preferably 0.5 to 72 hours.
In the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, 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 0.5 to 168 hours, more preferably 0.5 to 72 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. On the other hand, in the method (ii), a reaction solution containing polyimide is obtained. This reaction solution may be used as it is 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. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. 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. The isolation and purification of the polyimide can be performed by performing the same operation as described above as the isolation and purification method of the polyamic acid.

[Terminal-modified polymer]
The polyamic acid or polyimide that can be contained in the liquid crystal aligning agent of the present invention may be a terminal-modified polymer having 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-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n -Hexadecyl succinic acid 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 10 parts by weight or less, more preferably 6 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 polyimide obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, and has a solution viscosity of 30 to 500 mPa · s when a 10% by weight solution is obtained. It is more preferable to have it.
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.

（式（２）中、Ｒ^Ｉ、Ｒ^ＩＩ、Ｚ^Ｉ、Ｚ^ＩＩ、ｎ１、ｎ２、ｎ３およびｎ４は、それぞれ、上記式（２^０）におけるのと同義である。）
で表される化合物（以下、「化合物（ｂ２）」という。）の１〜（ｎ−１）モル部（ただしｎは上記化合物（ｂ１）の有するエポキシ基の個数である。）と
を反応させて得られる化合物であることが好ましい。
［化合物（ｂ１）］
本発明における化合物（ｂ１）としては、下記式（ｂ１−１）または（ｂ１−２） <(B) Compound>
The compound (B) in the liquid crystal aligning agent of the present invention is a compound having an epoxy group and a group represented by the above formula (2 ⁰ ). Such a compound (B) is
(B1) 1 mol part of a compound having 2 to 8 epoxy groups (hereinafter referred to as “compound (b1)”) and (b2) the following formula (2)

(In the formula (2), R ^I , R ^II , Z ^I , Z ^II , n1, n2, n3 and n4 are respectively synonymous with those in the above formula (2 ⁰ ).)
1 to (n-1) mole parts (where n is the number of epoxy groups of the compound (b1)) of the compound represented by formula (hereinafter referred to as “compound (b2)”). It is preferable that it is a compound obtained by this.
[Compound (b1)]
As the compound (b1) in the present invention, the following formula (b1-1) or (b1-2)

It is preferable that it has a structure represented by these.
The compound (b1) having a structure represented by the above formula (b1-1) preferably has two structures represented by the above formula (b1-1), and specific examples thereof include ethylene. Glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, benzene-1,4-diol diglycidyl ether 2-methylbenzene-1,4-diol diglycidyl ether, 2-ethylbenzene-1,4-diol diglycidyl ether, 2-n-hexylbenzene-1,4-diol diglycidyl ether, 2-n-dodecylbenzene -1,4 Diglycidyl ether, 2-trifluoromethyl-benzene-1,4-diol diglycidyl ether, 2,5-diethylbenzene-1,4-like diglycidyl ether can be exemplified.
As the compound (b1) having a structure represented by the above formula (b1-2), those having one or two structures represented by the above formula (b1-2) are preferable. N, N ′, N′-tetraglycidyl-5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, N, N, N ′, N′-tetraglycidyl-6-amino -1- (4′-aminophenyl) -1,3,3-trimethylindane, N, N, N ′, N′-tetraglycidyl-2,7-diaminofluorene, N, N, N ′, N′— Tetraglycidyl-1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, N, N, N ′, N′-tetraglycidyltetramethylenediamine, N, N, N ′, N′-tetraglycidylhexamethylenediamine , N, N, N ′, N′-tetra Rishijiru 3,6 diaminocarbazole, the following formula (b1-2-1) ~ (b1-2-4)

(In the above formula, B is a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -CO-, -O- ( CH ₂ ) _g —O—, —S—, —SO ₂ —, —C (CH ₃ ) ₂ —, —C (C ₂ H ₅ ) ₂ — or —C (CF ₃ ) ₂ —, provided that g is an integer of 1 to 12, and when a plurality of B are present, the plurality of B may be the same or different from each other, and each R is independently a hydrogen atom or a carbon number of 1 to 6 An alkyl group of 1 to 4 carbon atoms, a is independently 0 or 1, b is independently an integer of 0 to 3, and c is independently , An integer from 0 to 4, d is an integer from 0 to 5, and e is an integer from 0 to 10 independently. Ri, f is an integer of 0 to 11, G are each glycidyl group.)
And the like, and the like. In the above formulas (b1-2-1) to (b1-2-4), two B or B bonded to a benzene ring or a cyclohexane ring and — (CH ₂ ) _a —NG ₂ are each represented by the benzene It is preferably in the 1,4-position of the ring or cyclohexane ring.
Specific examples of the compound represented by the formula (b1-2-1) include, for example, N, N-diglycidylaminobenzene, N, N-diglycidyl-2-n-hexylaminobenzene, N, N-diglycidyl- 2,2′-dimethyl-4-aminobiphenyl, N, N-diglycidylaminomethylbenzene and the like;
Specific examples of the compound represented by the above formula (b1-2-2) include N, N-diglycidylaminocyclohexane, N, N-diglycidylaminomethylcyclohexane and the like;

Specific examples of the compound represented by the formula (b1-2-3) include, for example, N, N, N ′, N′-tetraglycidyl-p-phenylenediamine, N, N, N ′, N′-tetra Glycidyl-m-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2-methyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2-n-propyl- 1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2-n-hexyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2-trifluoro Methyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2,5-dimethyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2, 2'-dimethyl-4 4′-diaminobiphenyl, N, N, N ′, N′-tetraglycidyl-2,2′-diethyl-4,4′-diaminobiphenyl, N, N, N ′, N′-tetraglycidyl-2,2 '-Ditrifluoromethyl-4,4'-diaminobiphenyl, N, N, N', N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminobiphenyl, N, N, N ', N '-Tetraglycidyl-3,3'-diethyl-4,4'-diaminobiphenyl, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] propane, N, N, N' , N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylethane, N, N, N ′, N′-tetraglycidyl- 4, '-Diaminodiphenyl ether, N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenyl sulfide, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylsulfone, N , N, N ′, N′-tetraglycidyl-4,4′-diaminobenzanilide, N, N, N ′, N′-tetraglycidyl-4,4′-diaminobenzophenone, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (N, N-diglycidyl-4-aminophenyl) hexafluoropropane, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] sulfone, 1,4-bis (N, N-diglycidyl-4-aminophenoxy) benzene, 4,4 '-Bis (N, N-diglycidyl-4-aminophenoxy) biphenyl, 1,3-bis (N, N-diglycidyl-4-aminophenoxy) benzene, 1,3-bis (N, N-diglycidyl-3- Aminophenoxy) benzene, N, N, N ′, N′-tetraglycidyl-m-xylenediamine and the like;

Specific examples of the compound represented by the above formula (b1-2-4) include, for example, N, N, N ′, N′-tetraglycidyl-1,4-diaminocyclohexane, N, N, N ′, N ′. -Tetraglycidyl-1,3-bis (aminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-1,4-bis (aminomethyl) cyclohexane, N, N, N', N'-tetra Examples thereof include glycidyl-4,4′-methylenebis (cyclohexylamine).
Among these, as the compound (b1), a compound having one or two structures represented by the above formula (b1-2) has an epoxy group reactivity and a vertical alignment property of the liquid crystal alignment film to be formed. N, N-diglycidylaminobenzene, N, N-diglycidylaminomethylcyclohexane, N, N-diglycidylaminomethylbenzene, N, N, N ′, N ′ are particularly preferable. -Tetraglycidyl-p-phenylenediamine, N, N, N ', N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, N, N, N', N'-tetraglycidyl- 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] propane, N, N, N ′ N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenyl ether, N, N, N ′, N′-tetraglycidyl-4, 4′-diaminobenzophenone, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] hexafluoropropane, N, N, N ′, N′-tetraglycidylhexamethylenediamine, N, N, N ′, N′-tetraglycidyl-1,3-bis (aminomethyl) benzene, N, N, N ′, N′-tetraglycidyl-m-xylenediamine and N, N, N ′, N′— Mention may be made of tetraglycidyl-1,3-bis (aminomethyl) cyclohexane.

[Compound (b2)]
In the compound (b2), the alkyl group having 4 to 40 carbon atoms of R ¹ in the above formula (2) is preferably an alkyl group having 6 to 40 carbon atoms, and specifically, for example, a hexyl group, an octyl group, a decyl group. , Dodecyl group, hexadecyl group, stearyl group, etc .;
The fluoroalkyl group having 4 to 40 carbon atoms is preferably a fluoroalkyl group having 4 to 20 carbon atoms. Specifically, for example, a trifluoromethylpropyl group, a trifluoromethylbutyl group, a trifluoromethylhexyl group, or trifluoromethyldecyl is used. A group, a pentafluoroethylpropyl group, a pentafluoroethylbutyl group, a pentafluoroethyloctyl group, etc .;
Examples of the hydrocarbon group of 17 to 51 having a steroid skeleton include the following formulas (R ^I -1) to (R ^I -3)

(In formulas (R ^I -1) to (R ^I -3), "*" represents a bond.)
The groups represented by the above can be mentioned respectively.
The cyclohexylene group and the phenylene group of R ^II in the above formula (2) are preferably a 1,4-cyclohexylene group and a 1,4-phenylene group, respectively. In the above formula (2), as the divalent group represented _by- (R ^II ) _n1- , when n1 is 1, for example, 1,4-phenylene group, 1,2-cyclohexylene group, etc. ;
In the case where n1 is 2, for example, 4,4′-biphenylene group, 4,4′-bicyclohexylene group,

(In the formula, a bond marked with "*" is R ^I side.)
The groups represented by each of the above can be mentioned as preferred examples.
N3 in the above formula (2) is preferably 2.
Preferred compounds (b2) in the present invention include, for example, stearic acid, hexyloxybenzoic acid, octyloxybenzoic acid, decyloxybenzoic acid, dodecyloxybenzoic acid, octadecyloxybenzoic acid, trifluoromethylbenzoic acid, trifluoromethoxybenzoic acid. , Trifluoromethylpropyloxybenzoic acid, trifluoromethylbutyloxybenzoic acid, hexafluoropropyloxybenzoic acid, the following formulas (b2-1) and (b2-2)

And the like, and the like.
A preferable compound (B) in the liquid crystal aligning agent of the present invention is 1 mole part of the compound (b1) as described above and 1 to (n-1) mole part of the compound (b2) (where n is the compound (b1) It is a compound obtained by reacting in an appropriate organic solvent. A more preferable use ratio of the compound (b2) to 1 mol part of the compound (b1) is 1 to (n / 2) mol part when n is an even number, and 1 to 1 when n is an odd number. {(N + 1) / 2} mole parts. For example, when the compound (b1) is a compound having two structures represented by the above formula (b1-2) (in this case, the number of epoxy groups is 4), the compound (b2) 1 to 3 mol parts, preferably 1 to 2 mol parts are used per 1 mol part of (b1).
As an organic solvent which can be used for the said reaction, the organic solvent illustrated as what is used for the synthesis | combination of said polyamic acid can be mentioned. Aprotic organic solvents are preferred, and specifically, for example, N-methyl-2-pyrrolidone, acetonitrile, dimethyl sulfoxide, N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylimidazolidinone, dimethyl Examples thereof include sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like. As a use ratio of the organic solvent, the ratio of the total weight of the compound (b1) and the compound (b2) in the reaction solution is preferably 1% by weight or more, and a ratio of 5 to 50% by weight. More preferably.
The temperature during the reaction is preferably 20 to 250 ° C, more preferably 50 to 180 ° C. The reaction time is preferably 0.1 to 72 hours, more preferably 0.5 to 48 hours.
A solution containing the preferred compound (B) is thus obtained. This solution may be used as it is for the preparation of the liquid crystal aligning agent of the present invention, or may be used for the preparation of the liquid crystal aligning agent of the present invention after isolating and purifying the compound (B) from the reaction solution. In order to isolate and purify the compound (B) from the reaction solution, for example, a liquid-liquid extraction method, column chromatography, distillation method or the like can be used.

A preferable compound (B) in the present invention is derived from the epoxy group derived from the compound (b1) by reacting part of the epoxy group possessed by the compound (b1) with the compound (b2) and the compound (b2). Together with the group R ^I. Therefore, when the liquid crystal aligning agent of this invention contains the (B) compound, a liquid crystal aligning film excellent in vertical alignment can be formed without impairing the printability of the liquid crystal aligning agent.
As a more preferable example of the compound (B), for example, the following formulas (B-1) to (B-4):

(In the above formula, B is a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -CO-, -O- ( CH ₂ ) _g —O—, —S—, —SO ₂ —, —C (CH ₃ ) ₂ —, —C (C ₂ H ₅ ) ₂ — or —C (CF ₃ ) ₂ —, provided that g is an integer of 1 to 12, and when a plurality of B are present, the plurality of B may be the same or different from each other, and each R is independently a hydrogen atom or a carbon number of 1 to 6 An alkyl group of 1 to 4 carbon atoms, a is independently 0 or 1, b is independently an integer of 0 to 3, and c is independently , An integer from 0 to 4, d is an integer from 0 to 5, and e is each independently an integer from 0 to 10. In it, f is an integer of 0 to 11, ^{X I} is a glycidyl ^{group, X II} is the following formula (3-1) or (3-2)

(In the formulas (3-1) and (3-2), R ^I , R ^II , Z ^I , Z ^II , n1, n2, n3 and n4 are respectively synonymous with those in the above formula (2). )
X ^III and X ^IV are each independently a glycidyl group or a group represented by the above formula (3-1) or (3-2). )
In particular, among these compounds, the following formulas (B-1-1) to (B-1-3), (B-2-1) and (B-3-) 1) to (B-3-4)

(In the above formula, X ^{I to} X ^IV , R, c and d have the same meanings as in the above formulas (B-1) to (B-4), respectively.)
The compounds represented by each of these are preferred. Here, the group represented by the above formula (3-1) and the group represented by the above formula (3-2) may be mixed in one molecule of the compound (B). You may mix and use the (B) compound which has group represented by 1), and the (B) compound which has group represented by the said Formula (3-2).
The proportion of the compound (B) used in the liquid crystal aligning agent of the present invention is 100 of at least one polymer selected from the group consisting of (A) polyamic acid and polyimide (hereinafter referred to as “(A) polymer”). Preferably it is 0.1-40 weight part with respect to a weight part, More preferably, it is 0.1-30 weight part, Furthermore, it is preferable that it is 0.2-25 weight part.

<Other additives>
The liquid crystal alignment film of the present invention contains the above-mentioned (A) polymer and (B) compound as essential components, but may contain other components as necessary. Examples of such other components include (C) a compound having at least one epoxy group in the molecule (excluding those corresponding to the above compound (B), hereinafter simply referred to as “epoxy compound”), (D ) Functional silane compounds.
[(C) Epoxy compound]
The (C) epoxy compound can be used from the viewpoint of further improving the adhesion of the liquid crystal alignment film to be formed to the substrate surface. Examples of the (C) epoxy compound that can be used here include the same compounds as the compound (b1). Among these, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin 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-aminomethylcyclohexane and the like are preferable.
The blending ratio of these (C) epoxy compounds is preferably 30 parts by weight or less, more preferably 0.1 to 25 parts by weight with respect to 100 parts by weight of the (A) polymer. In addition, it is preferable that the sum total of the usage-amount of these (C) epoxy compounds and the usage-amount of (B) compound does not exceed 40 weight part with respect to 100 weight part of (A) polymers.

[(D) Functional silane compound]
The (D) functional silane compound can be used from the viewpoint of further improving the printability of the liquid crystal aligning agent of the present invention. Examples of the (D) functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino). Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, 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, Examples thereof include N-bis (oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
The use ratio of these (D) functional silane compounds is preferably 2 parts by weight or less, more preferably 1 part by weight or less, relative to 100 parts by weight of the polymer (A).

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is composed of the above-mentioned (A) polymer and (B) compound and other additives optionally blended as required, preferably dissolved in an organic solvent. The
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. 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. Preferred examples of such an organic solvent include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2- Pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i- Propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, di Examples include ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in combination of two or more. A particularly preferred solvent composition is a composition obtained by combining the above-mentioned solvents, and (A) the polymer and (B) compound and other additives optionally blended in the liquid crystal aligning agent do not precipitate, And it is a composition which the surface tension of a liquid crystal aligning agent becomes the range of 25-40 mN / m.

The solid content concentration of the liquid crystal aligning agent of the present invention (the ratio of the total weight of the components excluding the organic solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. However, it is preferably in the range of 1 to 10% by weight. That is, when the liquid crystal aligning agent of the present invention is applied to the substrate surface and the organic solvent is removed to form a coating film that becomes a liquid crystal aligning film, the solid content concentration is less than 1% by weight. The film thickness of this coating film may be too small to obtain a good liquid crystal alignment film. On the other hand, if the solid content concentration exceeds 10% by weight, the film thickness of the coating film will be excessive. Similarly, it may be 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 solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent 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 inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0-100 degreeC, More preferably, it is 20-60 degreeC.
The liquid crystal aligning agent of this invention can be used suitably in order to form the liquid crystal aligning film especially used for a vertical alignment type liquid crystal display element.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above. As a preferable operation mode in the liquid crystal display element of the present invention, a vertical alignment type can be exemplified. Hereinafter, a method for producing a vertical alignment type liquid crystal display element using the liquid crystal aligning agent of the present invention will be described.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3).
(1) First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface. As a pair of two substrates provided with a patterned transparent conductive film, the liquid crystal aligning agent of the present invention is preferably formed on each transparent conductive film forming surface, preferably a roll coater method, a spinner method, a printing method, an inkjet method. Each is coated by the method, and then the coated surface is formed by heating each coated surface. Since the liquid crystal aligning agent of this invention is excellent in printability, it is preferable to employ | adopt the printing method as a coating method.
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, and alicyclic polyolefin can be used.
As the transparent conductive film provided on one surface of the substrate, a 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. 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, a method of using a mask having a desired pattern when forming a transparent conductive film, etc. be able to. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.

After applying 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 0.1 to 10 minutes, more preferably 0.5 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 1 to 300 minutes, more preferably 2 to 120 minutes. Although the liquid crystal aligning agent of this invention forms the coating film used as an orientation film by removing an organic solvent after application | coating, the polymer contained in the liquid crystal aligning agent of this invention is a polyamic acid or an imide ring structure, and an amic acid structure. In the case of a polyimide having both of the above, it may be further heated after the formation of the coating film so that the dehydration ring-closing reaction proceeds to form a more imidized coating film.
The film thickness of the coating film formed here is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.
(2) The coating film formed as described above can be used as it is as a liquid crystal alignment film for a vertical alignment type liquid crystal display element, but this film surface is optionally subjected to a rubbing treatment. May be.
The rubbing treatment can be performed by rubbing the coating film surface in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton.

(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. In order to manufacture a liquid crystal cell, the following two methods can be 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.
In any of the above methods, it is desirable to remove the flow alignment at the time of filling the liquid crystal by heating the liquid crystal cell to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooling it to room temperature.
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 crystals and smectic liquid crystals. 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, or 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.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following, the solution viscosity of the polymer solution and the imidization ratio of the polyimide were evaluated by the following methods, respectively.
[Solution viscosity]
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type viscometer for a solution having a polymer concentration of 10% by weight using the solvent indicated in each synthesis example.
[Imidation rate]
The polyimide was sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and determined from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference substance, and the following formula (1) was obtained.
Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a polyimide precursor (polyamic acid). The number ratio of other protons to one proton of NH group in

<Synthesis of (B) Compound>
Synthesis Example B1 (N- (2-hydroxy-3-n-octyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine and N- (3-hydroxy-2-n-octyl) Synthesis of mixtures with oxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine)
In a 200 mL three-necked flask under nitrogen atmosphere, 18.0 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-m-xylenediamine and 12.5 g of 4-n-octyloxybenzoic acid ( 0.05 mol) was mixed, and 122.2 g of N-methyl-2-pyrrolidone was added and stirred. By reacting this under stirring at 100 ° C. for 4 hours under nitrogen, N- (2-hydroxy-3-n-octyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m- About 150 g of a solution containing 20% by weight of a mixture of xylenediamine and N- (3-hydroxy-2-n-octyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine is obtained. It was.
Synthesis Example B2 (N- (2-hydroxy-3-n-dodecyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine and N- (3-hydroxy-2-n-dodecyl) Synthesis of mixtures with oxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine)
In a 200 mL three-neck flask under a nitrogen atmosphere, 18.0 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-m-xylenediamine and 15.3 g of 4-n-dodecyloxybenzoic acid ( 0.05 mol) was mixed, and 133.2 g of N-methyl-2-pyrrolidone was added and stirred. By reacting this under stirring at 100 ° C. for 4 hours under nitrogen, N- (2-hydroxy-3-n-dodecyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m- About 165 g of a solution containing 20% by weight of a mixture of xylenediamine and N- (3-hydroxy-2-n-dodecyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine is obtained. It was.

Synthesis Example B3 (N- (2-hydroxy-3-n-dodecyloxybenzoyloxy) propyl-N, N ', N'-triglycidyl-4,4'-diaminodiphenylmethane and N- (3-hydroxy-2- n-dodecyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-4,4′-diaminodiphenylmethane)
In a 200 mL three-necked flask under nitrogen atmosphere, 21.1 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane and 4-n-dodecyloxybenzoic acid 15 .3 g (0.05 mol) was mixed, and 145.6 g of N-methyl-2-pyrrolidone was added and stirred. By reacting this under stirring at 100 ° C. for 6 hours under nitrogen, N- (2-hydroxy-3-n-dodecyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-4,4 Contains 20% by weight of a mixture of '-diaminodiphenylmethane and N- (3-hydroxy-2-n-dodecyloxybenzoyloxy) propyl-N, N', N'-triglycidyl-4,4'-diaminodiphenylmethane About 180 g of solution was obtained.
Synthesis Example B4 (N- (2-hydroxy-3-trifluoromethylpropyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine and N- (3-hydroxy-2-trifluoro) Synthesis of mixtures with methylpropyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine)
In a 200 mL three-neck flask under nitrogen atmosphere, 18.0 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-m-xylenediamine and 9.5 g of 4-trifluoromethylpropyloxybenzoic acid (0.05 mol) was mixed, and 110.1 g of N-methyl-2-pyrrolidone was added and stirred. By reacting this under stirring at 100 ° C. for 4.5 hours under nitrogen, N- (2-hydroxy-3-trifluoromethylpropyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl is obtained. A solution containing 20% by weight of a mixture of m-xylenediamine and N- (3-hydroxy-2-trifluoromethylpropyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine About 136 g was obtained.
Synthesis Example B5 (Synthesis of mixture of compound (B-3-2-1-1) and compound (B-3-2-1-2))
Scheme 1 below

Thus, a mixture of the compound (B-3-2-1-1) and the compound (B-3-2-1-2) was synthesized.
In a 200 mL three-necked flask under a nitrogen atmosphere, 18.0 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-m-xylenediamine and 24.4 g of compound (b2-1) (0. 05 mol), and 110.1 g of N-methyl-2-pyrrolidone was added and stirred. By reacting this under stirring at 100 ° C. for 4.5 hours under nitrogen, a mixture of the compound (B-3-2-1-1) and the compound (B-3-2-1-2) was obtained. About 192 g of a solution containing 20% by weight was obtained.
Synthesis Example B6 (Synthesis of mixture of compound (B-3-2-2-1) and compound (B-3-2-2-2))
Scheme 2 below

Then, a mixture of the compound (B-3-2-2-1) and the compound (B-3-2-2-2) was synthesized.
In a 200 mL three-necked flask under a nitrogen atmosphere, 18.0 g (0.05 mol) of N, N, N ′, N′-tetraglycidyl-m-xylenediamine and the compound (b-217.6 g (0.05 mol) ) Was added and stirred with 110.1 g of N-methyl-2-pyrrolidone, which was reacted under stirring at 100 ° C. for 4.5 hours under nitrogen to give compound (B-3-2-2). -1) and about 187 g of a solution containing 20% by weight of a mixture of the compound (B-3-2-2-2) was obtained.

<(A) Synthesis of polymer>
[Synthesis of polyimide]
Synthesis examples PI01 to PI13
The amount of diamine and tetracarboxylic dianhydride shown in Table 1 are added to N-methyl-2-pyrrolidone in this order to obtain a solution having a monomer concentration of 20% by weight, and the reaction is carried out at 60 ° C. for 4 hours. And solutions containing polyamic acid were obtained. A small amount of each solution was collected, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight by adding N-methyl-2-pyrrolidone is shown in Table 1.
Next, pyridine and acetic anhydride were added to each of the polyamic acid solutions so that the number of moles shown in Table 1 was doubled with respect to 1 mole of the amic acid unit of the polyamic acid, and then heated to 110 ° C. For 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone (pyridine and acetic anhydride used in the dehydration ring-closing reaction were removed from the system by this operation), thereby polyimide. A solution containing 16% by weight of (PI-1) to (PI-13) was obtained.
Table 1 shows the imidization ratio of each polyimide contained in these polyimide solutions and the solution viscosities measured as N-methyl-2-pyrrolidone solutions having a polyimide concentration of 10% by weight.
[Synthesis of polyamic acid]
Synthesis examples PA01 to PA03
Polyamic acids (PA-1) to (PA-3) were reacted in the same manner as in Synthesis Examples PI01 to PI13 except that the amounts of diamine and tetracarboxylic dianhydride were changed as shown in Table 1. ) Were obtained. A small amount of each solution was collected, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight by adding N-methyl-2-pyrrolidone is shown in Table 1.

In Table 1, the abbreviations of diamine and tetracarboxylic acid anhydride have the following meanings, respectively.
<Diamine>
d-1: p-phenylenediamine d-2: 4,4′-diaminodiphenylmethane d-3: 2,2′-dimethyl-4,4′-diaminobiphenyl d-4: 1,3-bis (aminomethyl) Cyclohexane d-5: 1,3-bis (3-aminopropyl) tetramethyldisiloxane d-6: diamine represented by the above formula (D-10) d-7: represented by the above formula (D-8) Diamine <tetracarboxylic dianhydride>
t-1: 2,3,5-tricarboxycyclopentylacetic acid dianhydride t-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

Example 1
<Preparation of liquid crystal aligning agent>
(A) A solution containing the polyimide (PI-1) obtained in Synthesis Example PI01 as a polymer is taken in an amount corresponding to 100 parts by weight in terms of polyimide (PI-1), and γ-butyrolactone is added to this solution. N-methyl-2-pyrrolidone and butyl cellosolve were added, and N- (2-hydroxy-3-n-octyloxybenzoyloxy) propyl-N, N ′, N obtained in Synthesis Example B1 as a compound (B) was further added. A solution containing a mixture of '-triglycidyl-m-xylenediamine and N- (3-hydroxy-2-n-octyloxybenzoyloxy) propyl-N, N', N'-triglycidyl-m-xylenediamine In an amount corresponding to 5 parts by weight in terms of the compound (B) contained therein, and (C) N, N, N ′, N′-tetraglycine as the epoxy compound 10 parts by weight of -4,4'-diaminodiphenylmethane was added, the solvent composition was γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = 40: 30: 30 (weight ratio), and the solid content concentration was 6.5. A weight percent solution was obtained. When this solution was visually observed, it was a clear solution without turbidity. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 0.2 μm, and was subjected to the following printability evaluation.
Similarly, a solution having a solvent composition of γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = 40: 30: 30 (weight ratio) and a solid content concentration of 4.0% by weight was prepared. The liquid crystal aligning agent was obtained by filtering using a 0.2 micrometer filter, and this was used for evaluation of the following vertical alignment property and voltage holding ratio.
<Evaluation of printability>
About the liquid crystal aligning agent with a solid content concentration of 6.5% by weight prepared above, a glass with a transparent electrode made of an ITO film using a liquid crystal alignment film printing machine (product name “Angstromer” manufactured by Nissha Printing Co., Ltd.) After coating on the transparent electrode surface of the substrate and heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to obtain an average film thickness A 750 mm coating film was formed. This coating film was visually observed to check the degree of printing unevenness. Here, the printability is “very good” when no streaky irregularities or surface irregularities are found on the coating surface, and the printability when slight irregularities or surface irregularities are visible on the coating surface. When the printability of the liquid crystal aligning agent was evaluated as “bad” when the film surface was clearly confirmed to have streaky unevenness or surface irregularities or both, the printability of the liquid crystal aligning agent was “very good”. there were.

<Evaluation of vertical alignment evaluation>
[Manufacture of liquid crystal display elements for evaluation of vertical alignment]
The liquid crystal aligning agent having a solid content concentration of 4.0% by weight prepared above was 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, and then 80 ° C. After heating (pre-baking) on the hot plate for 1 minute to remove the solvent, the film was heated (post-baking) in a clean oven at 200 ° C. for 60 minutes to form a coating film having a thickness of 0.08 μm. The coating film was rubbed with a rubbing machine having a roll around which a rayon cloth was wound under the conditions of a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm. The substrate having the coated film after rubbing was ultrasonically cleaned in pure water for 1 minute, and further heated and dried in a clean oven at 100 ° C. for 10 minutes to produce a substrate having a coated film that had been rubbed. This series of operations was repeated to produce a pair (two) of substrates having a rubbing-treated coating film.
After applying an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm to the outer edges of the coating film forming surfaces of the pair of substrates, the liquid crystal alignment film surfaces face each other, and each coating film is rubbed. The adhesive was cured by overlapping and pressing so that the directions were antiparallel. Next, after filling a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) between the liquid crystal inlets and between the substrates, the liquid crystal inlets are sealed with an acrylic photo-curing adhesive, and further polarized on both sides outside the substrate. A liquid crystal display element for vertical alignment evaluation was manufactured by laminating the plates.
[Evaluation of vertical alignment]
With respect to this liquid crystal display element, the pretilt angle was measured by the crystal rotation angle method and found to be 89.5 °. It is known that the pretilt angle expression is reduced by rubbing treatment. Therefore, it can be said that the liquid crystal alignment film showing a pretilt angle of 89.0 ° or more despite the rubbing treatment is extremely excellent in vertical alignment.

<Evaluation of voltage holding ratio>
[Manufacture of liquid crystal display elements for evaluating voltage holding ratio]
In the above, voltage was applied in the same manner as in [Manufacture of liquid crystal display element for vertical alignment evaluation] in <Evaluation of vertical alignment evaluation> except that the rubbing treatment and subsequent ultrapure water washing and drying operation were not performed. A liquid crystal display element for retention evaluation was manufactured.
[Evaluation of voltage holding ratio]
About the liquid crystal display element manufactured above, after applying a voltage of 5 V at 60 ° C. with an application time of 60 microseconds and a span of 167 microseconds, the voltage holding ratio after 167 milliseconds from the release of application was measured. The voltage holding ratio of the liquid crystal display element was 99.3%.

Examples 2-45 and Comparative Examples 1-11
The solid content concentration of 6.5 wt.% Was the same as in Example 1 except that the types and amounts of (A) polymer, (B) compound and (C) epoxy compound were as shown in Table 2. Two types of liquid crystal aligning agents having different concentrations of% and 4.0% by weight were prepared and evaluated.
The evaluation results are shown in Table 2.

In addition, the abbreviations of the (B) compound and the (C) epoxy compound in Table 2 have the following meanings, respectively.
<(B) Compound>
B-1: N- (2-hydroxy-3-n-octyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine and N- (3- Hydroxy-2-n-octyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine mixture B-2: N- (2-hydroxy-3 synthesized in Synthesis Example B2 above) -N-dodecyloxybenzoyloxy) propyl-N, N ', N'-triglycidyl-m-xylenediamine and N- (3-hydroxy-2-n-dodecyloxybenzoyloxy) propyl-N, N', N Mixture with '-triglycidyl-m-xylenediamine B-3: N- (2-hydroxy-3-n-dodecyloxybenzoyloxy) synthesized in Synthesis Example B3 ) Propyl-N, N ', N'-triglycidyl-4,4'-diaminodiphenylmethane and N- (3-hydroxy-2-n-dodecyloxybenzoyloxy) propyl-N, N', N'-triglycidyl Mixture with -4,4'-diaminodiphenylmethane B-4: N- (2-hydroxy-3-trifluoromethylpropyloxybenzoyloxy) propyl-N, N ', N'-tri synthesized in Synthesis Example B4 above Mixture of glycidyl-m-xylenediamine and N- (3-hydroxy-2-trifluoromethylpropyloxybenzoyloxy) propyl-N, N ′, N′-triglycidyl-m-xylenediamine B-5: Synthesis described above A mixture of the compound (B-3-2-1-1) synthesized in Example B5 and the compound (B-3-2-1-2) B-6: synthesized in the above Synthesis Example B6 Mixture of Compound (B-3-2-2-1) and Compound (B-3-2-2-2) <(C) Epoxy Compound>
C-1: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane C-2: N, N, N ′, N′-tetraglycidyl-m-xylenediamine Above (A) heavy The union was used for the preparation of the liquid crystal aligning agent as the polymer solution obtained in the above synthesis example, and the amount used (part by weight) in Table 2 was a value converted to the polymer contained in the solution used. is there. In Examples 26 to 41 and Comparative Examples 6 to 10, two types of polymers were used as the polymer (A).
The above (A) polymer and (B) compound are each used for the preparation of the liquid crystal aligning agent as a solution synthesized in the above synthesis example, and the amount used (part by weight) in Table 2 is included in the used solution. It is a value converted into the amount of the (A) polymer or (B) compound.

Claims (7)

(A) At least one polymer selected from the group consisting of polyamic acid and polyimide, and (B) an epoxy group and the following formula (2 ⁰ )

(In the formula (2 ⁰ ), R ^I is an alkyl group having 4 to 40 carbon atoms or a fluoroalkyl group having 4 to 40 carbon atoms, or a hydrocarbon group having 17 to 51 carbon atoms having a steroid skeleton;
Z ^I represents a single ^bond, * ^-O-, a * -COO- or ^* -OCO- (where bond marked with "*" is ^{R I} side.)
R ^II is a cyclohexylene group or a phenylene group,
n1 is 1 or 2,
Provided that when n1 is 2, the two R ^IIs may be the same or different from each other;
n2 is 0 or 1;
Z ^II is ^{* -O-,} a * -COO- or ^* -OCO- (where bond marked with "*" is ^{R I} side.)
n3 is an integer of 0 to 2,
n4 is 0 or 1. )
The liquid crystal aligning agent characterized by including the compound which has group represented by these. The compound (B) is
(B1) 1 mol part of a compound having 2 to 8 epoxy groups and (b2) the following formula (2)

(In the formula (2), R ^I , R ^II , Z ^I , Z ^II , n1, n2, n3 and n4 are respectively synonymous with those in the above formula (2 ⁰ ).)
The compound obtained by making it react with 1- (n-1) mol part (however, n is the number of the epoxy groups which the said (b1) compound has) of the compound represented by these. Liquid crystal aligning agent. (B) The compounds are represented by the following formulas (B-1) to (B-4).

(In the above formula, B is a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -CO-, -O- ( CH ₂ ) _g —O—, —S—, —SO ₂ —, —C (CH ₃ ) ₂ —, —C (C ₂ H ₅ ) ₂ — or —C (CF ₃ ) ₂ —, provided that g is an integer of 1 to 12, and when a plurality of B are present, the plurality of B may be the same or different from each other, and each R is independently a hydrogen atom or a carbon number of 1 to 6 An alkyl group of 1 to 4 carbon atoms, a is independently 0 or 1, b is independently an integer of 0 to 3, and c is independently , An integer from 0 to 4, d is an integer from 0 to 5, and e is each independently an integer from 0 to 10. In it, f is an integer of 0 to 11, ^{X I} is a glycidyl ^{group, X II} is the following formula (3-1) or (3-2)

(In the formulas (3-1) and (3-2), R ^I , R ^II , Z ^I , Z ^II , n1, n2, n3 and n4 are respectively synonymous with those in the above formula (2). )
X ^III and X ^IV are each independently a glycidyl group or a group represented by the above formula (3-1) or (3-2). )
The liquid crystal aligning agent of Claim 2 which is at least 1 type of compound selected from the compound represented by each of these.   (B) The liquid crystal aligning agent as described in any one of Claims 1-3 which further contains epoxy compounds other than a compound.   (B) The liquid crystal aligning agent as described in any one of Claims 1-4 whose usage-amount of a compound is 0.01-40 weight part with respect to 100 weight part of (A) polymers.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1. (B1) 1 mol part of the compound having 2 to 8 epoxy groups and (b2) 1 to (n-1) mol part of the compound represented by the above formula (2) (where n is the compound (b1) above) And the number of epoxy groups possessed by the compound.