JP2010156934A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent for providing a liquid crystal alignment film in which electric property is hardly deteriorated and is excellent in printability even when printing is performed with a small amount of the liquid and to provide a liquid crystal display element the display quality of which is not deteriorated even when the liquid crystal display element is driven continuously for a long period of time. <P>SOLUTION: The liquid crystal alignment agent contains at least one polymer selected from the group consisting of polyamic acid which is obtained by reacting tetracarboxylic acid dianhydride containing 2,3,5-tricarboxy cyclopentyl acetic acid dianhydride with diamine containing specific diamine having an alkylbicyclohexyl group, and polymers obtained by imidizing the polyamic acid. The liquid crystal display element has the liquid crystal alignment film formed of the liquid crystal alignment agent. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent that can provide a liquid crystal alignment film with little deterioration in electrical characteristics and excellent printability, and a liquid crystal display element that does not deteriorate display quality even when continuously driven for a long time.

Currently, as a liquid crystal display element, a liquid crystal alignment film is formed on the surface of a substrate 0 provided with a transparent conductive film to form a substrate for a liquid crystal display element, and positive dielectric anisotropy is formed in a gap in which the two sheets are arranged to face each other. A so-called TN type (twisted nematic) in which a layer of a nematic liquid crystal having a liquid crystal layer is formed into a sandwich cell and the long axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. ) A TN liquid crystal display element having a liquid crystal cell is known (Patent Document 1). In addition, STN (Super Twisted Nematic) type liquid crystal display elements that can achieve a high contrast ratio compared to TN type liquid crystal display elements, IPS (In-Plane Switching) type liquid crystal display elements that have less viewing angle dependency, and less viewing angle dependency In addition, an optically compensated bend (OCB = Optically Compensated Bend) type liquid crystal display element excellent in high-speed response of a video screen, and a vertical alignment (VA = Vertical Alignment) type liquid crystal display element using a nematic liquid having negative dielectric anisotropy Have been developed (Patent Documents 2 to 5).
As materials for the liquid crystal alignment film in these liquid crystal display elements, polyimide, polyamide, polyester and the like are conventionally known, but in particular, polyimide is excellent in heat resistance, affinity with liquid crystal, mechanical strength, etc. Used in many liquid crystal display elements (Patent Documents 1 to 6).
In recent years, liquid crystal display elements have been developed for television applications. In a liquid crystal display element for television use, a high-speed response type liquid crystal is used in order to cope with the refinement of display and the development of advanced moving image fixing technology. When a liquid crystal display element using a liquid crystal for high-speed response is continuously driven for a long time with the backlight turned on, the image quality tends to deteriorate, and a solution from the liquid crystal alignment film is expected.
Furthermore, in order to effectively use the liquid crystal aligning agent, attempts have been made to reduce the liquid amount of the liquid crystal aligning agent used at the time of printing, and a liquid crystal aligning agent that exhibits excellent printability even with a small amount of liquid is desired.

JP-A-4-153622 JP 60-107020 A JP 56-91277 A US Pat. No. 5,928,733 Japanese Patent Laid-Open No. 11-258605 Japanese Patent Laid-Open No. 62-165628

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment agent that gives a liquid crystal alignment film with little deterioration in electrical characteristics and is excellent in printability even when printing is performed with a small amount of liquid. Another object of the present invention is to provide a liquid crystal display element in which the display quality does not deteriorate even when continuous driving is performed for a long time.
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 as follows.
Tetracarboxylic dianhydride including 2,3,5-tricarboxycyclopentyl acetic dianhydride, and the following formula (1)

(In the formula (1), R ^I is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and R ^II is —O— ^* , —COO— ^* or —OCO— ^* (wherein (The bond marked with “*” binds to the benzene ring.))
It achieves by the liquid crystal aligning agent containing the at least 1 sort (s) of polymer selected from the group which consists of the polyamic acid obtained by making the diamine containing the compound represented by and its imidation polymer react.
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 liquid crystal aligning agent of this invention is excellent in printability, even if it prints with a small liquid quantity, and gives the coating film which shows a high degree of uniformity. The coating film formed from the liquid crystal aligning agent of the present invention is excellent in electric characteristics, and even if this is used as a liquid crystal alignment film of a liquid crystal display element and driven for a long time under lighting of a backlight, the electric characteristics do not deteriorate. Accordingly, the liquid crystal display element of the present invention having such a liquid crystal alignment film can be suitably used as a display element in various display devices because the display quality does not deteriorate even when continuous driving is performed for a long time. .
The liquid crystal display element of the present invention is suitably applied to display devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, personal digital assistants, digital cameras, mobile phones, various monitors, and liquid crystal televisions. can do.

The liquid crystal aligning agent of this invention is obtained by making the tetracarboxylic dianhydride containing 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and the diamine containing the compound represented by the said Formula (1) react. It contains at least one polymer selected from the group consisting of polyamic acids and imidized polymers thereof.
<Polyamic acid>
The polyamic acid that the liquid crystal aligning agent of the present invention can contain includes a tetracarboxylic dianhydride including 2,3,5-tricarboxycyclopentylacetic acid dianhydride and a compound represented by the above formula (1). It can be synthesized by reacting with a diamine.

[Tetracarboxylic dianhydride]
The tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention includes 2,3,5-tricarboxycyclopentylacetic acid dianhydride. As the tetracarboxylic dianhydride, only 2,3,5-tricarboxycyclopentylacetic acid dianhydride may be used, or 2,3,5-tricarboxycyclopentylacetic acid dianhydride and other tetracarboxylic acid A dianhydride may be used in combination.
Examples of other tetracarboxylic dianhydrides that can be used here 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-cyclopentanetetracarboxylic dianhydride Anhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane 2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5- (tetrahydro-2,5-dioxo-3) -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c]- Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] -furan-1,3-dione, 5- (2,5-dioxotetrahi Rofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro- 3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4, 9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, the following formulas (TI) and (T-II)

(In the above formula, 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 ² are present. ⁴ may be the same or different.
An alicyclic tetracarboxylic dianhydride other than an aliphatic tetracarboxylic dianhydride and 2,3,5-tricarboxycyclopentylacetic dianhydride, such as a compound represented by each of
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.
Other tetracarboxylic dianhydrides that can be used in the present invention include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3 -Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic 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- (tetrahydride -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 , 4′-Benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4 ′ Biphenylsulfonetetracarboxylic dianhydride, 2,3 ′, 2,3′-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, the above formula (TI) Among the compounds represented by formula (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)

That at least one selected from the group consisting of compounds represented by the following (hereinafter referred to as “other specific tetracarboxylic dianhydride (1)”) can exhibit good liquid crystal alignment. From the viewpoint of being able to.
Other specific tetracarboxylic dianhydrides (1) include, in particular, 1,2,3,4-cyclobutanetetracarboxylic 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-carbox Norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10- tetraone, pyromellitic It is preferably at least one selected from the group consisting of an anhydride and a compound represented by the above formula (T-5).
The tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention is 2,3,5-tricarboxycyclopentylacetic acid dianhydride in an amount of 20 mol% or more based on the total tetracarboxylic dianhydride. It is preferable that it is contained, more preferably 50 mol% or more, and particularly preferably 80 mol% or more.

[Diamine]
The diamine used for synthesizing the polyamic acid in the present invention is a diamine containing a compound represented by the above formula (1).
R ^I in the above formula (1) is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom. R ^I is preferably a linear alkyl group having 3 to 20 carbon atoms. Specific examples thereof include n-butyl group, n-pentyl group, n-hexyl group, group, n-heptyl group, n -Octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n -An octadecyl group, n-nonadecyl group, n-eicosyl group etc. can be mentioned. Particularly preferred ^{R I} are alkyl groups of straight-chain having 4 to 12 carbon atoms.
R ^II is —O— ^* or —OCO— ^* (where a bond marked with “*” is bonded to a benzene ring). ) Is preferred.
When R ^II is —O— ^* (where the bond marked with “*” is bonded to the benzene ring), the two amino groups must be in positions 2 and 4 with respect to R ^II . But;
R ^II is -OCO- ^* (wherein "*" a bond marked is bonded to the benzene ring.) When it, two amino groups may be in the position of the 3 and 5 positions with respect to ^{R II} Are preferred.
That is, preferable compounds represented by the above formula (1) are the following formulas (1-1) and (1-2).

(In the above formula, R ^I has the same meaning as in the above formula (1).)
It is a compound represented by each of these.
The compound represented by the above formula (1-1) is, for example, the following scheme 1-1.

(In scheme 1-1, R ^I has the same meaning as in formula (1) above.)
The alcohol represented by the formula (2) is converted into an alkoxide in the presence of a suitable base such as t-butoxy potassium, and then reacted with 2,4-dinitrochlorobenzene to obtain a formula (1-1A) After obtaining the intermediate compound represented, it can be synthesized by reducing it using a suitable reducing system such as palladium carbon and hydrazine.
The compound represented by the above formula (1-2) is, for example, the following scheme 1-2.

(In scheme 1-2, R ^I has the same meaning as in formula (1) above.)
Thus, an alcohol represented by the formula (2) is reacted with 3,5-dinitrobenzoyl chloride in the presence of a suitable base such as pyridine to give an intermediate compound represented by the formula (1-2A). Once obtained, it can be synthesized by reduction using an appropriate reduction system such as palladium carbon and hydrazine.
The alcohol represented by the formula (2) can be synthesized by an appropriate method such as a Grignard reaction, a Friedel-Crafts acylation reaction, or a Kishner reaction that is generally used for the synthesis of a liquid crystal compound.
The compound represented by the above formula (1-1) and the compound represented by the above formula (1) represented by the compound represented by the above formula (1-2) are high by having a bicyclohexane unit. The compound represented by the above formula (1) has an advantage that a liquid crystal alignment film exhibiting vertical alignment properties is provided. Further, the compound represented by the above formula (1) has an advantage that it is easy to obtain raw materials used for synthesis.
The diamine used for synthesizing the polyamic acid in the present invention may be a diamine consisting only of the compound represented by the above formula (1), or other than the compound represented by the above formula (1). The diamine may be further included.

  Examples of other diamines that can be used here 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'- 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] hexafluoro Propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-amino Phenyl) -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 (trifluorome Til) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 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.)
Aromatic diamines such as compounds represented by each of the above;
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 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'-di (4-aminophenyl) -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, R ⁸ is an alkyl group having 1 to 4 carbon atoms, and a2 is an integer of 0 to 3 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), 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 1 to 3 respectively. 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.
As the monovalent organic group of R ¹⁰ having a steroid skeleton in R ¹⁰ of the above formula (D-III), those having 17 to 51 carbon atoms are preferable, and those having 17 to 30 carbon atoms are more preferable. Specific examples of R ¹⁰ having 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.
In synthesizing the polyamic acid in the present invention, other diamines used together with the compound represented by the formula (1) are p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′- Diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 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-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4 -Aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 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′-di (4-aminophenyl) -benzidine, the above formula (D-I) Formula of the compounds represented by in (D-6)

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

Of the compounds represented by formula (D-III) and 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 formula (D-8) ~ (D-16)

It is preferable that it contains at least one selected from the group consisting of the compounds represented by each (hereinafter referred to as “other specific diamine”). Other particularly preferred diamines are p-phenylenediamine, 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoro. Methyl-4,4′-diaminobiphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4 -Aminophenyl) fluorene, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4'-methylenebis ( Cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene and 4,4′-bis (4-amino) Nophenoxy) at least one selected from the group consisting of biphenyl.
The diamine used for synthesizing the polyamic acid in the present invention preferably contains 1 mol% or more of the compound represented by the above formula (1) with respect to the total diamine, and contains 5 to 50 mol%. Is more preferable, and it is particularly preferable to contain 10 to 40 mol%.
In addition to the compound represented by the above formula (1), the diamine used for synthesizing the polyamic acid that can be contained in the liquid crystal aligning agent of the present invention further includes other specific diamines as described above for all diamines. On the other hand, the content is preferably 5 to 99 mol%, more preferably 50 to 95 mol%, and particularly preferably 60 to 90 mol%.

[Synthesis of polyamic acid]
The polyamic acid in the present invention can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine.
The ratio of the tetracarboxylic dianhydride and the diamine compound used in the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.001 with respect to 1 equivalent of the amino group contained in the diamine compound. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 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 240 hours, more preferably 3 to 150 hours. Here, 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 And aprotic polar solvents such as 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 compound (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 80% by weight or less, more preferably based on the total of the organic solvent and the poor solvent. Is 60% by weight or less, more preferably 50% by weight or less.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, 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. You may use for preparation of a liquid crystal aligning agent, after refine | purifying. 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 the polyamic acid as described above to imidize.
Tetracarboxylic dianhydrides used for the synthesis of imidized polymers are tetracarboxylic dianhydrides including 2,3,5-tricarboxycyclopentylacetic acid dianhydride. As the tetracarboxylic dianhydride used for the synthesis of the imidized polymer, only 2,3,5-tricarboxycyclopentylacetic acid dianhydride may be used, or 2,3,5-tricarboxycyclopentylacetic acid. A dianhydride and another tetracarboxylic dianhydride may be used in combination. Examples of other tetracarboxylic dianhydrides that can be used here include the same compounds as described above as other tetracarboxylic dianhydrides that can be used to synthesize polyamic acid. .
The other tetracarboxylic dianhydride used in the synthesis of the imidized polymer is at least one selected from alicyclic tetracarboxylic dianhydrides other than 2,3,5-tricarboxycyclopentylacetic acid dianhydride. It is preferable to use a seed (hereinafter referred to as “other specific tetracarboxylic dianhydride (2)”). Other specific tetracarboxylic dianhydrides (2) include in particular 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: 6-dianhydride and 4,9- At least one selected from oxatricyclo [5.3.1.0 ^{2, 6]} the group consisting of undecane -3,5,8,10- tetraone are preferred.
The tetracarboxylic dianhydride used for synthesizing the imidized polymer that can be contained in the liquid crystal aligning agent of the present invention is 2,3,5-tricarboxycyclopentylacetic acid dianhydride, all tetracarboxylic acid It is preferable to contain 20 mol% or more with respect to the dianhydride, more preferably 50 mol% or more, and particularly preferably 80 mol% or more.
The diamine used for the synthesis of the imidized polymer is the same as that described above as the diamine used for the synthesis of polyamic acid.

The imidized polymer may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure of the polyamic acid that is the precursor, or by dehydrating and cyclizing only a part of the amic acid structure. It may be a partially imidized product in which an acid structure and an imide ring structure coexist.
The imidized polymer contained in the liquid crystal aligning agent of the present invention preferably has an imidation ratio of 40% or more, more preferably 60% or more, and further preferably 60 to 85%. By using an imidized polymer having an imidization ratio in this range, a liquid crystal aligning agent that provides a liquid crystal alignment film having excellent printability and more excellent electrical characteristics can be obtained.
The said imidation rate represents the ratio for which the number of the imide ring structure with respect to the sum total of the number of the amic acid structure of an imidation polymer and the number of imide ring structures is represented by a percentage. At this time, a part of the imide ring may be an isoimide ring. The imidation rate was determined by dissolving the imidized polymer in a suitable deuterated solvent (for example, deuterated dimethyl sulfoxide), and measuring ¹ H-NMR at room temperature using tetramethylsilane as a reference substance. I).

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

(In Formula (I), 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 precursor of an imidized polymer ( This is the number ratio of other protons to one NH group proton in the polyamic acid).

The dehydration ring closure of the polyamic acid for synthesizing the imidized polymer may be performed by (i) a method of heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, and dehydrating agent and dehydration ring closure in this solution. It is carried out by a method in which a catalyst is added and heated as necessary.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 0.5 to 24 hours, more preferably 2 to 12 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 use ratio of the dehydrating agent is preferably 0.01 to 20 mol with respect 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 use ratio of the dehydration ring-closing catalyst is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent to be 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 24 hours, more preferably 2 to 8 hours.
The imidized polymer 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 imidized polymer. Good. On the other hand, in the method (ii), a reaction solution containing an imidized polymer 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. After separation, the liquid crystal aligning agent may be used for preparation, or the isolated imidized polymer may be purified and then used for preparation of the liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydration ring closure 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 that can be contained in the liquid crystal aligning agent of the present invention and the imidized polymer thereof may each be a terminal-modified polymer whose molecular weight is adjusted. 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 5 parts by weight or less, more preferably 2 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. It is.
-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, preferably 30 to 500 mPa · s. More preferably, it has a solution viscosity of s.
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 additives>
The liquid crystal alignment film of the present invention contains, as an essential component, at least one polymer selected from the group consisting of the polyamic acid as described above and an imidized polymer obtained by dehydrating and ring-closing the polyamic acid. Other components may be contained. 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.
[Other polymers]
The other polymer is a polyamic obtained by reacting a tetracarboxylic dianhydride containing 2,3,5-tricarboxycyclopentylacetic acid dianhydride with a diamine containing a compound represented by the above formula (1). It is a polymer other than an acid and its imidized polymer. For example, a polyamic acid (hereinafter referred to as “others” obtained by reacting a tetracarboxylic dianhydride with a diamine not containing the compound represented by the above formula (1). ), 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) acrylates. Among these, as the other polymer, it is preferable to use at least one selected from the group consisting of other polyamic acids and other imidized polymers.
The other polyamic acid and its imidized polymer as described above are respectively the above polyamic acid and its imide except that tetracarboxylic dianhydride and a diamine not containing the compound represented by the above formula (1) are used. It can synthesize | combine according to the synthesis | combining method of chemical polymer. The tetracarboxylic dianhydride used as a raw material at this time is at least one selected from the group consisting of alicyclic tetracarboxylic dianhydride and pyromellitic dianhydride (hereinafter referred to as “specific tetracarboxylic dianhydride”). Those containing "anhydride") are preferred. Specific tetracarboxylic dianhydrides include 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-1 , 2-Dicarboxylic anhydride , 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3 , 5,8,10-tetraone and pyromellitic dianhydride are preferred. The tetracarboxylic dianhydride used for synthesizing other polyamic acid or its imidized polymer is 40 mol of the specific tetracarboxylic dianhydride as described above with respect to the total tetracarboxylic dianhydride. % Or more is preferable, and 80 mol% or more is more preferable.

As a diamine used for synthesizing another polyamic acid or an imidized polymer thereof, a diamine containing at least one selected from the group consisting of an aromatic diamine and 4,4′-methylenebis (cyclohexylamine) is used. In particular, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 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, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-( -Phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4'-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene and 4,4'-bis (4-aminophenoxy) ) Those containing at least one selected from the group consisting of biphenyl are preferred. The diamine used for synthesizing another polyamic acid or its imidized polymer is at least one selected from the group consisting of the aromatic diamine and 4,4′-methylenebis (cyclohexylamine) as described above. It is preferable that 40 mol% or more is included with respect to diamine, and 80 mol% or more is more preferable.
As another polymer, it is more preferable to use another polyamic acid.
When the liquid crystal aligning agent of the present invention contains another polymer, the content ratio of the other polymer is preferably the total of the polyamic acid and its imidized polymer and the other polymer. It is 95 weight% or less, More preferably, it is 50-90 weight%, Furthermore, it is preferable that it is 65-85 weight%.

  Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′- Diaminodiphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - such as aminomethyl cyclohexane may be mentioned as preferred. The blending ratio of these epoxy compounds is preferably based on 100 parts by weight of the total of the polymers (the polyamic acid contained in the liquid crystal aligning agent and its imidized polymer and other polymers). Is 40 parts by weight or less, more preferably 0.1 to 30 parts by weight, and further preferably 5 to 25 parts by weight.

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 blending ratio of these functional silane compounds is preferably 40 parts by weight or less with respect to 100 parts by weight of the total polymer.

<Liquid crystal aligning agent>
The 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 described above, and other additives optionally blended as necessary. .
Particularly preferred liquid crystal aligning agents of the present invention include a liquid crystal aligning agent containing the imidized polymer and the epoxy compound as described above, a liquid crystal aligning agent or an imidized polymer containing the imidized polymer as described above and another polyamic acid. And other polyamic acid and an epoxy compound.
The liquid crystal aligning agent of the present invention is constituted by dissolving the above components, preferably 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. 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.

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 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 liquid crystal aligning agent of the present invention prepared as described above can be suitably used particularly for forming a liquid crystal alignment film of 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. The liquid crystal display element of the present invention is preferably a vertical alignment type liquid crystal display element having a vertical alignment type liquid crystal cell.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, a printing method, or an ink jet method, and then applied. A coating film is formed by heating the surface. Here, the substrate is made of, for example, glass such as float glass or soda glass; plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyalicyclic olefin, and polyalicyclic olefin hydrogenated product. A transparent substrate 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. In order to obtain a patterned transparent conductive film, for example, a method of forming a desired pattern by photo-etching after forming a transparent conductive film without a pattern on a substrate, and having a desired pattern when forming a transparent conductive film A method of directly forming a transparent conductive film patterned using a mask can be used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the liquid crystal alignment film to be formed and the substrate surface, for example, a functional silane compound, a functional titanium compound, or the like is previously applied on the substrate. May be. For the purpose of preventing dripping of the alignment agent applied after application of the liquid crystal alignment agent, preheating (pre-baking) is preferably performed. 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 0.5 to 10 minutes, more preferably 1 to 5 minutes. Thereafter, a firing (post-baking) 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 5 to 180 minutes, more preferably 10 to 120 minutes.
Although the liquid crystal aligning agent of this invention forms the coating film which is a liquid crystal aligning 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. In the case of an imidized polymer having both a structure and a coating film, the film may be further heated to cause the dehydration ring-closing reaction to proceed to form a more imidized coating film.
The film thickness of the coating film (liquid crystal alignment film) formed here is preferably 0.001 to 1 μm, and more preferably 0.005 to 0.5 μm.

(2) Two substrates on which a liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates. 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. Since the liquid crystal aligning agent of the present invention can form a liquid crystal alignment film excellent in vertical alignment, a liquid crystal display element in which ODF unevenness does not occur even when a vertical alignment type liquid crystal display element is manufactured by the ODF method is obtained. Has the advantage that
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 having negative dielectric illegality 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, and pyrimidine liquid crystal. Dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

<Synthesis of Compound Represented by Formula (1)>
Synthesis Example 1-1
[Synthesis of Compound Represented by Formula (1-1) above]
Synthesis of Compound (1-1-1) Scheme 2 below

Thus, compound (1-1-1) was synthesized.
Synthesis of Compound (1-1-1A) In a 3 L three-necked flask equipped with a stirrer, a nitrogen introduction tube and a thermometer, 200 g of Compound (2-1), 89 g of t-butoxy potassium, 26 g of tetrabutylammonium bromide and tetrahydrofuran 1 , 500 mL, and stirred for 3 hours under ice-cooling (this is referred to as reaction solution A).
On the other hand, 160 g of 2,4-dinitrochlorobenzene and 800 mL of tetrahydrofuran were charged into a 5 L three-necked flask equipped with a dropping funnel, a nitrogen introduction tube, a thermometer, and a stirrer, and the reaction solution A was allowed to stand for 1 hour or more under ice cooling. The solution was gradually added dropwise and reacted for 12 hours at room temperature. After completion of the reaction, the reaction mixture was filtered and poured into 10 L of water, and the generated precipitate was recovered. This precipitate was washed with methanol and isopropanol, and then recrystallized with a mixed solvent consisting of cyclohexane and hexane to obtain 180 g of compound (1-1-1A).
Synthesis of Compound (1-1-1) In a 2 L three-necked flask equipped with a reflux tube, a nitrogen introduction tube and a thermometer, 180 g of the compound (1-1-1A) obtained above, 12 g of 5% by weight palladium carbon, ethanol Charge 1.5 L and 750 mL of tetrahydrofuran, add 49 g of 28 wt% aqueous ammonia, add 243 g of hydrazine monohydrate over 5 minutes and stir for 1 hour, then react at 70 ° C. for 6 hours. It was. After completion of the reaction, the reaction mixture was poured into 15 L of water and the resulting precipitate was recovered. The precipitate was recrystallized from ethanol to obtain 83 g of Compound (1-1-1).

Synthesis Example 1-2
[Synthesis of Compound Represented by Formula (1-2) above]
Synthesis of Compound (1-2-1) Scheme 3 below

Thus, compound (1-2-1) was synthesized.
Synthesis of Compound (1-2-1A) Into a 5 L three-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen introduction tube, 151 g of Compound (2-1), 2.5 L of toluene and 3,5-dinitrobenzoyl 115 g of chloride was charged. Under ice-cooling, 80 mL of pyridine was added dropwise, followed by stirring at room temperature for 7 hours. After completion of the reaction, the reaction mixture was repeatedly washed 4 times with 2.5 L of water. Thereafter, the organic layer was dried over magnesium sulfate, concentrated, and recrystallized from a mixed solvent composed of ethanol and tetrahydrofuran to obtain 105 g of compound (1-2-1A).
Synthesis of Compound (1-2-1) Into a 5 L three-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen introduction tube, 89 g of the compound (1-2-1A) obtained above, ethanol 1 L, tetrahydrofuran 0 .5 L and 5 g of 5% by weight palladium carbon were charged, and 48 mL of hydrazine monohydrate was added dropwise under water cooling. After stirring at room temperature for 1 hour, the reaction was performed at 70 ° C. for 1 hour. After removing palladium carbon by filtration, 2.5 L of ethyl acetate was added, and washing with 2.5 L of water was repeated three times. The organic layer was concentrated and then recrystallized from ethanol to obtain 70 g of compound (1-2-1).

<Synthesis of imidized polymer>
Synthesis example PI-1
41.0 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as the tetracarboxylic anhydride and the compound (1-1-1) as the diamine (obtained in Synthesis Example 1-1. The same shall apply hereinafter. .) 13.1 g (corresponding to 0.2 mol with respect to 1 mol of TCA) and 15.8 g of p-phenylenediamine are dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours. Thus, a solution containing 20% by weight of polyamic acid was obtained. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,366 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 14.5 g of pyridine and 18.7 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone (by this solvent replacement operation, pyridine and acetic anhydride used in the dehydration cyclization reaction were removed from the system. The same applies hereinafter). As a result, a solution containing 20% by weight of the imidized polymer (A-1) having an imidization ratio of 50% was obtained.
Synthesis example PI-2
26.3 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic anhydride and 23.2 g of compound (1-1-1) as diamine (0.4 mol to 1 mol of TCA) And 10.5 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,352 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 12.8 g of pyridine and 16.5 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-2) having an imidization ratio of 50%. It was.

Synthesis example PI-3
41.0 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic anhydride and 13.1 g of compound (1-1-1) as diamine (0.2 mol to 1 mol of TCA) And 15.8 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,338 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 29.0 g of pyridine and 37.4 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-3) having an imidization rate of 80%. It was.
Synthesis example PI-4
26.3 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic anhydride and 23.2 g of compound (1-1-1) as diamine (0.4 mol to 1 mol of TCA) And 10.5 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,231 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 25.6 g of pyridine and 33.1 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-4) having an imidization rate of 80%. It was.

Synthesis example PI-5
18.3 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic anhydride and 6.0 g of compound (1-1-1) as diamine (0.2 mol with respect to 1 mol of TCA) ), 4.4 g of the compound represented by the above formula (D-10) (corresponding to 0.1 mol with respect to 1 mol of TCA) and 6.4 g of p-phenylenediamine were added to N-methyl-2- A solution containing 20% by weight of polyamic acid was obtained by dissolving in 140 g of pyrrolidone and reacting at 60 ° C. for 4 hours. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,980 mPa · s.
Next, 325 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 6.4 g of pyridine and 8.3 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-5) having an imidization rate of 51%. It was.
Synthesis example PI-6
40.5 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as the tetracarboxylic anhydride and the compound (1-2-1) as the diamine (obtained in Synthesis Example 1-2, the same applies hereinafter) 14.1 g (corresponding to 0.2 mol with respect to 1 mol of TCA) and 15.7 g of p-phenylenediamine are dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours. Thus, a solution containing 20% by weight of polyamic acid was obtained. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,605 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 14.2 g of pyridine and 18.3 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-6) having an imidization ratio of 50%. It was.

Synthesis example PI-7
25.4 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic anhydride and 24.4 g of compound (1-2-1) as diamine (0.4 mol to 1 mol of TCA) And 10.2 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,214 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 12.5 g of pyridine and 16.1 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-7) having an imidization rate of 51%. It was.
Synthesis example PI-8
4,3 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic anhydride and 13.9 g of compound (1-2-1) as diamine (0.2 mol with respect to 1 mol of TCA) And 15.6 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,538 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 28.5 g of pyridine and 36.8 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-8) having an imidization rate of 83%. It was.

Synthesis example PI-9
25.4 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic anhydride and 24.4 g of compound (1-2-1) as diamine (0.4 mol to 1 mol of TCA) And 10.2 g of p-phenylenediamine were dissolved in 280 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by weight of polyamic acid. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,231 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 25.0 g of pyridine and 32.2 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of imidized polymer (A-9) having an imidization rate of 79%. It was.
Synthesis example PI-10
18.3 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic anhydride and 6.3 g of compound (1-2-1) as diamine (0.2 mol to 1 mol of TCA) ), 4.3 g of the compound represented by the above formula (D-10) (corresponding to 0.1 mol with respect to 1 mol of TCA) and 6.2 g of p-phenylenediamine were added to N-methyl-2- A solution containing 20% by weight of polyamic acid was obtained by dissolving in 140 g of pyrrolidone and reacting at 60 ° C. for 4 hours. For this solution, the solution viscosity measured at 25 ° C. was 1,180 mPa · s.
Next, 325 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 6.5 g of pyridine and 8.3 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of the imidized polymer (A-10) having an imidization rate of 52%. It was.

<Synthesis of other polyamic acids>
Synthesis example PA-1
Pyromellitic dianhydride 109 g (0.50 mol) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride 98 g (0.50 mol) as tetracarboxylic dianhydride and 4,4- as diamine By dissolving 200 g (1.0 mol) of diaminodiphenyl ether in 2,290 g of N-methyl-2-pyrrolidone, reacting at 40 ° C. for 3 hours, and then adding 1,350 g of N-methyl-2-pyrrolidone. About 3,990 g of a solution containing 10% by weight of other polyamic acid (B-1) was obtained.
The solution viscosity of this other polyamic acid solution was 180 mPa · s.
Synthesis example PA-2
1,2,3,4-Cyclobutanetetracarboxylic dianhydride 98 g (0.50 mol) and pyromellitic dianhydride 109 g (0.50 mol) as tetracarboxylic dianhydride and 4,4 ′ as diamine -Dissolve 198 g (1.0 mol) of diaminodiphenylmethane in 2,290 g of N-methyl-2-pyrrolidone, react at 40 ° C. for 3 hours, and then add 1,350 g of N-methyl-2-pyrrolidone. As a result, about 4,000 g of a solution containing 10% by weight of another polyamic acid (B-2) was obtained.
The solution viscosity of this other polyamic acid solution was 113 mPa · s.

Synthesis example PA-3
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 200 g (1.0 mol) of 4,4′-diaminodiphenyl ether as diamine were added to N-methyl. After dissolving in 2,246 g of 2-pyrrolidone and reacting at 40 ° C. for 4 hours, by adding 1,321 g of N-methyl-2-pyrrolidone, 10 weight of other polyamic acid (B-3) was added. About 3,900 g of a solution containing% was obtained.
The solution viscosity of this other polyamic acid solution was 189 mPa · s.
Synthesis example PA-4
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1, .2) of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine. 0 mol) is dissolved in 3,670 g of N-methyl-2-pyrrolidone and reacted at 40 ° C. for 3 hours to obtain about 4,020 g of a solution containing 10% by weight of another polyamic acid (B-4). Obtained.
The solution viscosity of this other polyamic acid solution was 144 mPa · s.
Synthesis example PA-5
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 200 g (1.0 mol) of 4,4′-diaminodiphenyl ether as diamine were added to N-methyl-2 A solution containing 10% by weight of another polyamic acid (B-5) by dissolving in 2,404 g of pyrrolidone, reacting at 40 ° C. for 4 hours, and adding 1,412 g of N-methyl-2-pyrrolidone About 4,200 g was obtained.
The solution viscosity of this other polyamic acid solution was 162 mPa · s.

Synthesis example PA-6
54 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as the tetracarboxylic anhydride and 21 g of the compound (1-1-1) as the diamine (1,2,3,4-cyclobutanetetracarboxylic dianhydride) The polyamic acid (B-6) is obtained by dissolving 25 g of p-phenylenediamine in 400 g of N-methyl-2-pyrrolidone and reacting at room temperature for 4 hours. A solution containing 20% by weight was obtained. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,870 mPa · s.
Synthesis example PA-7
56 g of pyromellitic acid anhydride as tetracarboxylic acid anhydride, 20 g of compound (1-1-1) as diamine (corresponding to 0.2 mol per mol of pyromellitic acid anhydride) and 24 g of p-phenylenediamine Was dissolved in 400 g of N-methyl-2-pyrrolidone and reacted at room temperature for 4 hours to obtain a solution containing 20% by weight of polyamic acid (B-7). With respect to this solution, the solution viscosity measured at 25 ° C. was 3,240 mPa · s.

Synthesis example PA-8
57 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic anhydride and 23 g of compound (1-2-1) as diamine (1,2,3,4-cyclobutanetetracarboxylic dianhydride) The polyamic acid (B-8) is obtained by dissolving 25 g of p-phenylenediamine in 420 g of N-methyl-2-pyrrolidone and reacting at room temperature for 4 hours. A solution containing 20% by weight was obtained. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,770 mPa · s.
Synthesis example PA-9
60 g of pyromellitic anhydride as tetracarboxylic anhydride, 21 g of compound (1-2-1) as diamine (corresponding to 0.2 mol per 1 mol of pyromellitic anhydride) and 24 g of p-phenylenediamine Was dissolved in 420 g of N-methyl-2-pyrrolidone and reacted at room temperature for 4 hours to obtain a solution containing 20% by weight of polyamic acid (B-9). With respect to this solution, the solution viscosity measured at 25 ° C. was 1,840 mPa · s.
<Synthesis of other imidized polymers>
Synthesis example PI-11
As tetracarboxylic anhydride, the following formula (F)

22.7 g of the compound represented by the formula (Compound (F)) and 5.5 g of the compound (1-1-1) as a diamine (corresponding to 0.2 mol relative to 1 mol of the compound (F)) and p- A solution containing 20% by weight of polyamic acid was obtained by dissolving 6.7 g of phenylenediamine in 140 g of N-methyl-2-pyrrolidone and reacting at 60 ° C. for 4 hours. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,950 mPa · s.
Next, 325 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 6.0 g of pyridine and 7.7 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of an imidized polymer (R-1) having an imidization rate of 50%. It was.
Synthesis example PI-12
The above formula (F) as tetracarboxylic anhydride
22.6 g of the compound represented by the formula (Compound (F)) and 5.8 g of the compound (1-2-1) as a diamine (corresponding to 0.2 mol relative to 1 mol of the compound (F)) and p- A solution containing 20% by weight of polyamic acid was obtained by dissolving 6.5 g of phenylenediamine in 140 g of N-methyl-2-pyrrolidone and reacting at 60 ° C. for 4 hours. With respect to this solution, the solution viscosity measured at 25 ° C. was 1,050 mPa · s.
Next, 325 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 6.0 g of pyridine and 7.7 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of an imidized polymer (R-2) having an imidization ratio of 48%. It was.

Synthesis example PI-13
Take 175 g of the solution containing polyamic acid (B-6) obtained in Synthesis Example PA-6 (corresponding to 35 g in terms of polyamic acid (B-6)), and add N-methyl-2- Pyrrolidone (325 g) was added for dilution, and pyridine (7.7 g) and acetic anhydride (9.9 g) were further added to perform a dehydration ring-closing reaction at room temperature. As a result, the polymer became insoluble and precipitated.
Synthesis example PI-14
Take 175 g of the solution containing polyamic acid (B-7) obtained in Synthesis Example PA-7 (corresponding to 35 g in terms of polyamic acid (B-7)), and add N-methyl-2- Pyrrolidone (325 g) was added for dilution, and pyridine (7.2 g) and acetic anhydride (9.3 g) were further added to perform a dehydration ring-closing reaction at room temperature. As a result, the polymer became insoluble and precipitated.
Synthesis example PI-15
175 g of a solution containing polyamic acid (B-8) obtained in Synthesis Example PA-8 (corresponding to 35 g in terms of polyamic acid (B-8)) was taken, and N-methyl-2- Pyrrolidone (325 g) was added for dilution, and pyridine (7.7 g) and acetic anhydride (9.9 g) were further added to perform a dehydration ring-closing reaction at room temperature. As a result, the polymer became insoluble and precipitated.
Synthesis example PI-16
Take 175 g of the solution containing polyamic acid (B-9) obtained in Synthesis Example PA-9 (corresponding to 35 g in terms of polyamic acid (B-9)), and add N-methyl-2- Pyrrolidone (325 g) was added for dilution, and pyridine (7.3 g) and acetic anhydride (9.4 g) were further added to perform a dehydration ring-closing reaction at room temperature. As a result, the polymer became insoluble and precipitated.
Synthesis example PI-17
The following formula (G) as tetracarboxylic acid anhydride

43 g of the compound (compound (G)), 12 g of the compound (1-1-1) as a diamine (corresponding to 0.2 mol with respect to 1 mol of the compound (G)), and 15 g of p-phenylenediamine. A solution containing 20% by weight of polyamic acid was obtained by dissolving in 280 g of N-methyl-2-pyrrolidone and reacting at 60 ° C. for 4 hours. With respect to this solution, the solution viscosity measured at 25 ° C. was 2,050 mPa · s.
Next, 650 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 14 g of pyridine and 17 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system is replaced with new N-methyl-2-pyrrolidone to obtain a solution containing 20% by weight of an imidized polymer (R-2) having an imidization rate of 52%. It was.

<Preparation and evaluation of liquid crystal aligning agent>
[Preparation of liquid crystal aligning agent for printability evaluation and evaluation of printability]
Example 1
[Preparation of liquid crystal aligning agent for printability evaluation]
Taking the solution containing the imidized polymer (A-1) obtained in Synthesis Example 1 in an amount corresponding to 100 parts by weight in terms of the imidized polymer (A-1) contained therein, Here, 20 parts by weight of N, N, N ′, N′-tetraglycidyl-m-xylenediamine is added as an epoxy compound, and N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) are added to obtain a solvent composition. It was set as the solution of NMP: BC = 60: 40 (weight ratio) and solid content concentration of 7 weight%. A liquid crystal aligning agent (P-1) was prepared by filtering this solution using a filter having a pore size of 1 μm.
[Evaluation of printability]
Using the liquid crystal aligning agent (P-1) prepared above, a liquid crystal aligning agent dripping amount on an anilox roll using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd., model “Angstromer S40L-532”) Was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film under the condition of 20 drops (about 0.2 g). Here, the dropping amount of the liquid crystal aligning agent is a more severe printing condition because the amount of liquid is smaller than the dropping amount (30 drops (about 0.3 g) reciprocating) normally employed for the same type of printing press.
The substrate after application of the liquid crystal aligning agent was heated (pre-baked) at 80 ° C. for 1 minute to remove the solvent, and then heated (post-baked) at 180 ° C. for 10 minutes to form a coating film having a thickness of 80 nm.
When this coating film was visually observed for the presence or absence of repellency (pinhole) and printing unevenness, neither pinholes nor printing unevenness was observed, and the printability of the liquid crystal aligning agent (P-1) was good. Met.

[Preparation of liquid crystal aligning agent for liquid crystal cell production]
A liquid crystal aligning agent (S-1) was prepared in the same manner as described above except that in [Preparation of liquid crystal aligning agent for evaluation of printability], the solid content concentration of the solution before filtration was 4% by weight.
[Manufacture of liquid crystal cells]
The liquid crystal aligning agent (S-1) prepared above was applied with a spinner on a transparent conductive film made of an ITO film provided on the entire surface of one side of a 1 mm thick glass substrate, and heated at 80 ° C. for 1 minute on a hot plate. Pre-baking was performed, followed by post-baking at 230 ° C. for 30 minutes to form a coating film (liquid crystal alignment film) having a thickness of 0.08 μm. This operation was repeated to produce a pair (two) of substrates having a liquid crystal alignment film on the transparent conductive film.
After applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the respective outer edges of the pair of substrates having the liquid crystal alignment film, they are stacked and pressure-bonded so that the liquid crystal alignment film surfaces face each other. Cured. Next, a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled 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 vertically aligned liquid crystal. A cell was manufactured.
[Liquid crystal cell evaluation]
(1) Evaluation of voltage holding ratio After applying a voltage of 5 V to the liquid crystal cell produced above at 60 ° C. with an application time of 60 microseconds and a span of 16.7 microseconds, the voltage application was released from 16 The voltage holding ratio after 7 milliseconds was measured. The results are shown in Table 2.
(2) Evaluation of light resistance After the fluorescent lamp is turned on with the liquid crystal cell arranged at a distance of 5 cm from the 40 watt type white fluorescent lamp and irradiated with light for 1,000 hours, it is the same as the evaluation of the voltage holding ratio. The voltage holding ratio was measured again under the conditions described above. At this time, when the voltage holding ratio value after 1,000 hours irradiation is less than ± 2% compared to the initial voltage holding ratio value, the light resistance is “good”, and the case is more than ± 2% Were evaluated as light resistance “bad”.
The results are shown in Table 2.

(3) Evaluation of heat resistance For a liquid crystal cell manufactured in the same manner as described above, a voltage of 5 V was first applied with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage was maintained after 167 milliseconds from the release of application. The rate was measured. The numerical value at this time was defined as the initial voltage holding ratio (VHR _BF ).
After the VHR _BF measurement, the liquid crystal display element was put in an oven at 100 ° C., and thermal stress was applied for 1,000 hours. Next, after the liquid crystal display element was allowed to stand at room temperature and cooled to room temperature, the voltage holding ratio (VHR _AF ) after application of thermal stress was measured under the same conditions as those for the initial voltage holding ratio.
Formula (II) below

ΔVHR (%) = ((VHR _BF −VHR _AF ) ÷ VHR _BF ) × 100 (II)
Thus, the change rate (ΔVHR) of the voltage holding ratio before and after the application of the thermal stress was obtained, and when this change rate was less than 5%, the heat resistance was evaluated as “good”, and when the change rate was 5% or more, the heat resistance as “bad” was evaluated. .
The evaluation results are shown in Table 2.
(4) Evaluation of seizure resistance For a liquid crystal cell produced in the same manner as described above, a residual DC voltage after applying a voltage of 5 V for 20 hours at 60 ° C. was measured, and when this value was 0 to 500 mV, When the seizure property was “excellent” and was over 500 mV and 1,000 mV or less, the seizure resistance was evaluated as “good”.
The evaluation results are shown in Table 2.

Examples 2-9
In Example 1 above, instead of the solution containing the imidized polymer (A-1), the solutions containing the types and amounts of polymers listed in Table 1 were used, respectively, and N, N being epoxy compounds , N ′, N′-tetraglycidyl-m-xylenediamine was used in the same manner as in Example 1 except that the amount used was as shown in Table 1, and a liquid crystal aligning agent for printability evaluation (P-2) -(P-9) and liquid crystal aligning agent (S-2)-(S-9) for liquid crystal cell manufacture were prepared, respectively, and evaluation of printability and manufacture and evaluation of the liquid crystal cell were performed.
The evaluation results are shown in Tables 1 and 2.
Example 10
[Preparation of liquid crystal aligning agent for printability evaluation and evaluation of printability]
The amount corresponding to 20 parts by weight in terms of the imidized polymer (A-1) in the solution containing the imidized polymer (A-1) obtained in Synthesis Example 1 above, and obtained in Synthesis Example 6 above. The amount corresponding to 80 parts by weight in terms of the polyamic acid (B-1) in the solution containing the polyamic acid (B-1) is combined with N, N, N ′, N′-tetra as an epoxy compound. 20 parts by weight of glycidyl-m-xylenediamine was added, and N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were further added to obtain a solvent composition of NMP: BC = 60: 40 (weight ratio), solid content concentration 7 A weight percent solution was obtained. The solution was filtered using a filter having a pore diameter of 1 μm to prepare a liquid crystal aligning agent (P-10) for printability evaluation.
Printability was evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (P-10) prepared above was used.
The evaluation results are shown in Table 1.
[Preparation and Evaluation of Liquid Crystal Alignment Agent for Liquid Crystal Cell Production]
In the above [Preparation of liquid crystal aligning agent for printability evaluation], a liquid crystal aligning agent (S-10) for liquid crystal cell production was prepared in the same manner as above except that the solid content concentration of the solution before filtration was 4% by weight. did.
A liquid crystal cell was produced and evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (S-10) prepared above was used.
The evaluation results are shown in Table 2.

Examples 11-22
In Example 10 above, N, N, N ′, N′-tetraglycidyl-m—, which is an epoxy compound, was used using a solution containing each of the types and amounts of the imidized polymer and polyamic acid listed in Table 1. Liquid crystal aligning agents for printability evaluation (P-11) to (P-22) and liquid crystal for liquid crystal cell production, in the same manner as in Example 10, except that the amount of xylenediamine used was as described in Table 1. Alignment agents (S-11) to (S-22) were prepared, respectively, and evaluation of printability and production and evaluation of liquid crystal cells were performed.
The evaluation results are shown in Tables 1 and 2.
Examples 23-31
In Example 1 above, instead of the solution containing the imidized polymer (A-1), the solutions containing the types and amounts of polymers listed in Table 1 were used, respectively, and N, N being epoxy compounds , N ′, N′-Tetraglycidyl-m-xylenediamine was used in the same manner as in Example 1 except that the amount used was as shown in Table 1. (P-23) -(P-31) and liquid crystal aligning agent (S-23)-(S-31) for liquid crystal cell manufacture were prepared, respectively, and evaluation of printability and manufacture and evaluation of a liquid crystal cell were performed.
The evaluation results are shown in Tables 1 and 2.
Examples 32-44
In Example 10 above, N, N, N ′, N′-tetraglycidyl-m—, which is an epoxy compound, was used using a solution containing each of the types and amounts of the imidized polymer and polyamic acid listed in Table 1. Liquid crystal aligning agents for printability evaluation (P-32) to (P-44) and liquid crystal for liquid crystal cell production, in the same manner as in Example 10, except that the amount of xylenediamine used was as described in Table 1. Alignment agents (S-32) to (S-44) were prepared, respectively, and evaluation of printability and production and evaluation of liquid crystal cells were performed.
The evaluation results are shown in Tables 1 and 2.

Comparative Example 1
In Example 1 above, instead of the solution containing the imidized polymer (A-1), a solution containing the imidized polymer (R-1) obtained in Synthesis Example PI-11 was used. In the same manner as in Example 1, a liquid crystal aligning agent (RP-1) for printability evaluation was prepared, and the printability was evaluated. As a result, printing unevenness was observed in the formed coating film, and the printability was “bad”.
Comparative Example 2
In Example 1 above, instead of the solution containing the imidized polymer (A-1), a solution containing the imidized polymer (R-2) obtained in Synthesis Example PI-12 was used. In the same manner as in Example 1, a liquid crystal aligning agent for evaluation of printability (RP-2) was prepared, and the printability was evaluated. As a result, printing unevenness was observed in the formed coating film, and the printability was “bad”.
Comparative Example 3
In Example 1, in place of the solution containing the imidized polymer (A-1), the solution containing the polyamic acid (B-6) obtained in Synthesis Example PA-6 was used, and an epoxy compound was used. Otherwise, a liquid crystal aligning agent for printability evaluation (RP-3) and a liquid crystal aligning agent for liquid crystal cell production (RS-3) were respectively prepared in the same manner as in Example 1 to evaluate the printability and the liquid crystal When the production of the cell and the evaluation of the voltage holding ratio and the heat resistance were performed, the printability was “good”, the voltage holding ratio was 98%, and the heat resistance was “poor”.

Comparative Example 4
In Example 1, in place of the solution containing the imidized polymer (A-1), the solution containing the polyamic acid (B-7) obtained in Synthesis Example PA-7 was used, and an epoxy compound was used. Otherwise, a liquid crystal aligning agent for printability evaluation (RP-4) and a liquid crystal aligning agent for manufacturing a liquid crystal cell (RS-4) were respectively prepared in the same manner as in Example 1 to evaluate the printability and the liquid crystal. When the cell was manufactured and the voltage holding ratio, light resistance and heat resistance were evaluated, the printability was “good”, the voltage holding ratio was 96%, and both the light resistance and heat resistance were “bad”. It was.
Comparative Example 5
In Example 1, in place of the solution containing the imidized polymer (A-1), the solution containing the polyamic acid (B-8) obtained in Synthesis Example PA-8 was used, and the epoxy compound was used. In the same manner as in Example 1, a liquid crystal aligning agent for printability evaluation (RP-5) and a liquid crystal aligning agent for liquid crystal cell manufacture (RS-5) were prepared in the same manner as in Example 1 to evaluate printability and liquid crystal. When the production of the cell and the evaluation of the voltage holding ratio and the heat resistance were performed, the printability was “good”, the voltage holding ratio was 98%, and the heat resistance was “poor”.
Comparative Example 6
In Example 1, in place of the solution containing the imidized polymer (A-1), the solution containing the polyamic acid (B-9) obtained in Synthesis Example PA-9 was used, and the epoxy compound was used. The liquid crystal aligning agent for printability evaluation (RP-6) and the liquid crystal aligning agent for liquid crystal cell production (RS-6) were prepared in the same manner as in Example 1 except that the printability was evaluated. When the cell was manufactured and the voltage holding ratio, light resistance and heat resistance were evaluated, the printability was “good”, the voltage holding ratio was 96%, and both the light resistance and heat resistance were “bad”. It was.
Comparative Example 7
In Example 1, in place of the solution containing the imidized polymer (A-1), the solution containing the imidized polymer (R-3) obtained in Synthesis Example PI-17 was used, and an epoxy compound was used. In the same manner as in Example 1, a liquid crystal aligning agent for printability evaluation (RP-7) was prepared and evaluated for printability. As a result, print unevenness was observed. It was "bad".

Claims (6)

Tetracarboxylic dianhydride including 2,3,5-tricarboxycyclopentyl acetic dianhydride, and the following formula (1)

(In the formula (1), R ^I is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and R ^II is —O— ^* , —COO— ^* or —OCO— ^* (wherein (The bond marked with “*” binds to the benzene ring.))
A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a compound represented by the formula (I) and an imidized polymer thereof.   The diamine may be p-phenylenediamine, 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 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, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine) 1,4-bis (4-aminophenoxy) benzene and 4,4′-bis (4- Minofenokishi) are those containing at least one selected from the group consisting of biphenyl, a liquid crystal aligning agent of claim 1.   Further, at least one selected from the group consisting of a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine not containing the compound represented by the above formula (1) and an imidized polymer thereof. The liquid crystal aligning agent of Claim 1 or 2 containing a polymer.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.   The liquid crystal display element according to claim 4, which is a vertical alignment type.   A polyamic acid obtained by reacting a tetracarboxylic dianhydride containing 2,3,5-tricarboxycyclopentylacetic acid dianhydride with a diamine containing a compound represented by the above formula (1) or its imidized heavy weight Coalescence.