JP2007086287A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent with which a liquid crystal alignment layer having excellent storage stability, superior rubbing resistance, and an excellent voltage holding rate can be formed. <P>SOLUTION: The liquid crystal aligning agent contains a 100 wt.pts. component [A] and 0.01 to 30 wt.pts. component [B]. The component [A] is at least one kind of polymer selected out of (a) polyamic acid obtaining subjecting tetracarboxylic dianhydride and a diamine compound to reaction, (b) an imidized polymer of polyamic acid, (c) a mixture of polyamic acid and/or imizied polymer, and (d) a partially imidized polymer of polyamic acid. The component [B] is a glycidyl amine compound having a specified structure. <P>COPYRIGHT: (C)2007,JPO&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 form a liquid crystal alignment film having good storage stability, excellent rubbing resistance, and good voltage holding ratio, and a liquid crystal display element including the liquid crystal alignment film.

  At present, a liquid crystal alignment film made of an organic polymer or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a substrate for a liquid crystal display element. A so-called TFT liquid crystal panel in which layers are formed to form a sandwich cell and this liquid crystal display element is operated by TFT driving is becoming widespread in place of a conventional cathode ray tube monitor. As the liquid crystal display element, nematic liquid crystal having positive dielectric anisotropy is used as the liquid crystal, and the major axis of the liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate. A TN liquid crystal display element having a TN (Twisted Nematic) type liquid crystal cell is known. Further, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have a higher contrast than the TN type liquid crystal display elements and have less viewing angle dependency, have been developed. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 degrees between substrates. The birefringence effect generated by the above is utilized. In addition, IPS (In-Plane Switching) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have less viewing angle dependency than TN type liquid crystal display elements, have less viewing angle dependency and excellent high-speed response of video screens. An optical compensation bend (OCB) type liquid crystal display element has been developed. The liquid crystal alignment film has a function of controlling the alignment of the liquid crystal in these liquid crystal display elements, and a liquid crystal alignment material composed of an organic polymer or the like and a liquid crystal alignment agent including a solvent are applied to the substrate by a flexographic printing method or the like. Then, it is baked to form a resin film, which is obtained by imparting liquid crystal alignment ability. Examples of the organic polymer used as the liquid crystal alignment film material include an imidized polymer of polyamic acid as described in Patent Document 1 and Patent Document 2, a polyamic acid as described in Patent Document 3, and Patent Document A mixture of polyamic acid and / or imidized polymer as described in No. 4 and partially imidized polymer as described in Patent Document 5 are used.

However, when a liquid crystal display element or the like is produced using a liquid crystal aligning agent containing a conventionally known polyamic acid, imidized polymer, or partially imidized polymer, rubbing scratches are formed on the surface of the liquid crystal alignment film to be formed. There is a problem in that display defects are likely to occur and display defects resulting from this.
Patent Document 6 discloses a liquid crystal aligning agent containing a polymer obtained by using a diamine having a silsesquioxane skeleton in order to solve such a problem.
In order to solve such a problem, Patent Document 7 contains a polymer component composed of soluble polyimide, polyamide, polyamideimide or a mixture of two or more of these and a compound having a T8 type silsesquioxane skeleton. A liquid crystal aligning agent is disclosed.
Patent Document 8 discloses a liquid crystal aligning agent containing an epoxy group-containing compound having a specific structure as an essential component in order to solve such problems.
However, in the liquid crystal aligning agent disclosed in Patent Document 6, since the configuration of the polymer contained in the liquid crystal aligning agent is limited, the selection range of usable materials is narrowed, and the original purpose of the alignment film is In some cases, it is difficult to achieve compatibility with the liquid crystal panel display characteristics.
In addition, in the liquid crystal aligning agent disclosed in Patent Document 7, since the compound having a silsesquioxane skeleton has no reactivity with the polymer or has low reactivity with the polymer, an alignment film is formed. When the liquid crystal panel is in contact with the liquid crystal, the compound having a silsesquioxane skeleton contained in the alignment film may be eluted into the liquid crystal and behave as an impurity in the liquid crystal, thereby causing display defects. Is done.
In addition, in the liquid crystal aligning agent disclosed in Patent Document 8, a part of TN type, STN type, IPS type, vertical, which has been subjected to rubbing treatment under stronger conditions in order to make the alignment uniform. In the alignment type liquid crystal panel, the rubbing resistance may be insufficient.

Japanese Patent Laid-Open No. 05-60565 Japanese Patent No. 2893671 Japanese Patent No. 2600368 JP-A-10-183120 JP 05-216044 A JP 2004-323665 A JP 2004-341165 A Japanese Patent No. 3206401

In view of the above circumstances, an object of the present invention is to provide a liquid crystal aligning agent that can form a liquid crystal aligning film having good storage stability, excellent rubbing resistance, and good voltage holding ratio.
Another object of the present invention is to provide a liquid crystal display device comprising the liquid crystal alignment film of the present invention.
Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are as follows. First, the liquid crystal alignment is characterized by containing 100 parts by weight of the following component [I] and 0.01 to 30 parts by weight of the following component [b]: Achieved by the agent.
[A] Polyamic acid obtained by reacting at least one polymer selected from the following (a) to (d) (a) tetracarboxylic dianhydride and a diamine compound (b) imidized weight of polyamic acid Compound (c) Mixture of polyamic acid and / or imidized polymer (d) Partial imidized polymer of polyamic acid
[B] A tetraglycidylamine compound having the structure of the following formula (A).

(Wherein R ₁ and R ₂ represent a monovalent organic group which may be the same or different, and X represents a divalent organic group)

According to the present invention, the above objects and advantages of the present invention are secondly related to 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-5-methyl-5 ( At least one of tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride is 1 The polymer of [I] obtained by using tetracarboxylic dianhydride containing at least mol%, and the compound of [B], the component [B] is 0.01 to 30 parts by weight with respect to 100 parts by weight of the component [A]. It is achieved by a liquid crystal aligning agent characterized by containing at a ratio of
According to the present invention, the above objects and advantages of the present invention are thirdly achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning agent which is excellent in rubbing resistance and can provide the liquid crystal aligning film with a favorable voltage holding ratio can be provided. Furthermore, the liquid crystal display element having the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention can be effectively used in various devices, for example, a desk calculator, a wristwatch, a table clock, a count display board, a mobile phone, a word processor, a personal computer. It can be suitably used as a display device such as a liquid crystal data projector or a liquid crystal television.

Hereinafter, the present invention will be described in detail. The liquid crystal aligning agent used in the present invention includes a compound represented by the formula (A),
(A) a polyamic acid which is a reaction product of a tetracarboxylic dianhydride and a diamine compound,
(B) either an imidized polymer of polyamic acid, or (c) a mixture of polyamic acid and imidized polymer.
The polyamic acid (a) may be used alone or as a mixture, and the imidized polymer (b) may be used alone or as a mixture. The imidized polymer includes not only a polymer composed of only an imide polymer unit but also a partially imidized polymer containing a polyamic acid polymer unit in addition to the imide polymer unit. The polyamic acid polymerized unit is a repeating unit represented by the following formula (I-1), and the imide polymer unit is a repeating unit represented by the following formula (I-2). The polymer may be (a) a polyamic acid having a repeating unit represented by the following formula (I-1), or (b) an imide having a repeating unit represented by the following formula (I-2). (C) a polyamic acid having a repeating unit represented by the following formula (I-1) and an imidized polymer having a repeating unit represented by the following formula (I-2). It may be a mixture. In addition, a polymer in which a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2) are bonded in the same molecule in a random or block form is the above “ It belongs to “partially imidized polymer”.

(In the formula, P ¹ is a tetravalent organic group, and Q ¹ is a divalent organic group.)

(In the formula, P ² is a tetravalent organic group, and Q ² is a divalent organic group.)

  The polyamic acid is obtained by a ring-opening addition reaction of a tetracarboxylic dianhydride and a diamine compound, and the imidized polymer is usually obtained by dehydrating and ring-closing a polyamic acid. A partially imidized polymer is usually obtained by a method in which polyamic acid is partially dehydrated and closed, or a method in which an amic acid prepolymer and an imide prepolymer are combined to synthesize a block-like or random copolymer. Can do.

[Tetracarboxylic dianhydride]
Examples of tetracarboxylic dianhydrides that can be used for the synthesis of polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxy Lubornane-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-hex Hydro-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-dioxotetrahydrofura ) -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), aliphatic and alicyclic tetracarboxylic dianhydrides such as compounds represented by the following formulas (I) and (II);

(Wherein R ¹ and R ³ represent a divalent organic group having an aromatic ring, R ² and R ⁴ represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ⁴ are the same. But it may be different.)

Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic 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-dicarboxyphenoxy) diph Nylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenyl Phosphine 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), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-o Fragrances such as kutandiol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), compounds represented by the following formulas (1) to (4) Group tetracarboxylic dianhydride. These may be used alone or in combination of two or more.

The tetravalent organic group represented by P ¹ in the repeating unit (amic acid unit) represented by the above formula (I-1) and the repeating unit (imide unit) P represented by the above formula (I-2) ^{All of the} tetravalent organic groups represented by ² are groups derived from tetracarboxylic dianhydride. These may be the same or different.
Among tetracarboxylic dianhydrides, 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-5-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride are particularly preferred.

[Diamine compound]
Examples of the diamine compound used for the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, and 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, 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'-diaminobenzof Non, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2, 2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis ( 4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-bis ( 4-Aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-di Chloro-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 ′ -Aromatic diamines such as bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl;
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylene diamine, tricyclo [6.2.1.02,7] -undecylenedimethyl diamine, 4, Aliphatic and cycloaliphatic diamines such as 4'-methylenebis (cyclohexylamine);
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine 5,6-diamino-1,3 Dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3, , 6-diaminoacridine, bis (4-aminophenyl) phenylamine, and compounds represented by the following formulas (III) to (IV), etc. A diamine having a nitrogen atom;

(In the formula, R ⁵ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X represents a divalent organic group.)

Wherein R ⁶ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, X represents a divalent organic group, and a plurality of X May be the same or different.)
Monosubstituted phenylenediamines represented by the following formula (V); diaminoorganosiloxanes represented by the following formula (VI);

(Wherein R ⁷ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁸ represents a steroid skeleton, A monovalent organic group having a group selected from a fluoromethyl group and a fluoro group or an alkyl group having 6 to 30 carbon atoms is shown.)

(Wherein R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)
Examples include compounds represented by the following formulas (9) to (13). These diamine compounds can be used alone or in combination of two or more.

(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)

  Of these, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2, 2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2 , 2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine 4,4'-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) ) Benzene, 4,4′-bis (4-aminophenoxy) biphenyl, compounds represented by the above formulas (9) to (13), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4- Diaminopyrimidine, 3,6-diaminoacridine, a compound represented by the following formula (14) among the compounds represented by the above formula (III), and a compound represented by the following formula (15) among the compounds represented by the above formula (IV) Of the compounds represented by formula (V) and the compounds represented by formula (V), compounds represented by the following formulas (16) to (22) are preferred.

<Polyamic acid>
The ratio of tetracarboxylic dianhydride and diamine compound used in the polyamic acid synthesis reaction is such that the acid anhydride group of tetracarboxylic dianhydride is 0.1 equivalent to 1 equivalent of amino group contained in the diamine compound. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.6 to 1.4 equivalents is more preferable. The synthetic reaction of polyamic acid is usually carried out in an organic solvent under a temperature condition of -20 to 150 ° C, preferably 0 to 100 ° C. Here, the organic solvent is not particularly limited as long as it can dissolve both the raw material diamine compound and tetracarboxylic dianhydride and the synthesized polyamic acid, and preferred examples thereof include N-methyl-2-pyrrolidone. Aprotic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidone, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; -Phenol solvents such as cresol, xylenol, phenol, halogenated phenol can be exemplified. The amount of organic solvent used (a) is usually such that the total amount (b) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. An amount is preferred.

  For the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are poor solvents for polyamic acid, are used in combination as long as the polyamic acid to be produced does not precipitate. be able to. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-i-propyl ether, ethylene glycol Recall mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl 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, diacetone alcohol, propylene carbonate, propylene glycol Bruno ethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether, and the like α- pinene.

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

<Imidized polymer>
The imidized polymer constituting the liquid crystal aligning agent of the present invention can be prepared by dehydrating and ring-closing the polyamic acid. The polyamic acid is dehydrated and closed by (i) a method in which the polyamic acid is heated, or (ii) the polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydrating ring-closing catalyst are added to this solution and heated as necessary. By the method.

  The reaction temperature in the method (i) of heating the polyamic acid is usually 50 to 200 ° C., 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.

  On the other hand, in the above method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used. Can do. The amount of the dehydrating agent used 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 amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And the reaction temperature of dehydration ring closure reaction is 0-180 degreeC normally, Preferably it is 10-150 degreeC. In addition, the imidized polymer can be purified by performing the same operation as the polyamic acid purification method on the reaction solution thus obtained.

<Partially imidized polymer>
The partially imidized polymer used in the present invention has a structure obtained by partially imidizing the polyamic acid, and the preferred imidization ratio in the partially imidized polymer used in the present invention is 10 to 10. 90%, more preferably 30 to 70%. Here, the “imidation ratio” is the percentage of the number of repeating units that form an imide ring with respect to the total number of repeating units in the polymer. At this time, a part of the imide ring may be an isoimide ring.

  As a method of synthesizing a partially imidized polymer, (i) a method of synthesizing by partially dehydrating and ring-closing by heating the polyamic acid, and (ii) dissolving the polyamic acid in an organic solvent, A method of synthesizing by partially dehydrating and ring-closing by adding a dehydrating agent and a dehydrating ring-closing catalyst to the mixture, and (iii) mixing a tetracarboxylic dianhydride, a diamine compound and a diisocyanate compound, (Iv) a polyamic acid prepolymer having a reactive group derived from an amino group or a tetracarboxylic acid at the molecular end, and an amino group or a tetracarboxylic acid at the molecular end. Polyimide prepolymer having reactive groups derived from acids, different from any polyamic acid prepolymer How synthesized by reacting, it is used.

  In the method (i), the reaction temperature is usually 300 ° C. or lower, preferably 100 to 250 ° C. When the reaction temperature exceeds 300 ° C., the molecular weight of the resulting imide group-containing polyamic acid may decrease.

  On the other hand, as the dehydrating agent used in the method (ii), acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.2 to 20 mol with respect to 1 mol of the polyamic acid repeating unit. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. Moreover, it is preferable that the usage-amount of an imidation catalyst shall be 0.1-10 mol with respect to 1 mol of dehydrating agents to be used. In addition, as an organic solvent used for reaction of dehydration ring closure, 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 is 0-180 degreeC normally, Preferably it is 60-150 degreeC. Moreover, an imide group containing polyamic acid can be refine | purified by performing operation similar to the purification method of polyamic acid with respect to the reaction solution obtained in this way.

  Specific examples of the diisocyanate compound used in the reaction (iii) include aliphatic diisocyanates such as hexamethylene diisocyanate; cyclohexane-1,2-diisocyanate, 1-methylcyclohexane-2,4-diisocyanate, and 1,2-dimethyl. Cyclohexane-ω, ω′-diisocyanate, 1,4-dimethylcyclohexane-ω, ω′-diisocyanate, isophorone diisocyanate, 1,3,5-trimethyl-2-propylcyclohexane-1ω, 2ω-diisocyanate, dicyclohexylmethane-4, Cycloaliphatic diisocyanates such as 4′-diisocyanate; diphenylmethane-4,4′-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenyle And aromatic diisocyanates such as bets - diisocyanate, 1-methyl-2,6-phenylene diisocyanate, diisocyanates represented by the following formula (22) to (26).

Of these, preferred are dicyclohexylmethane-4,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, 1-methyl-2,4-phenylene diisocyanate, and 1-methyl-2,6-phenylene diisocyanate. . These can be used alone or in combination of two or more. In addition, a catalyst in particular is not required for the reaction of (iii) above, and the reaction temperature is usually 50 to 200 ° C, preferably 100 to 160 ° C.
In the above method (iv), the polyamic acid prepolymer and / or polyimide prepolymer is equimolar so that the number of moles is, for example, 1.001 to 2 times the number of moles of tetracarboxylic acid used. By using an excessive amount exceeding the amount, it can be synthesized as a prepolymer having an amino group at the molecular end. Alternatively, by using an excess amount exceeding the equimolar amount so that the molar number of tetracarboxylic acid is, for example, 1.001 to 2 times the molar number of diamine used, it is derived from the carboxylic acid at the molecular end. It can be synthesized as a prepolymer having a reactive group. In the synthesis of the polyimide prepolymer, the polyimide prepolymer having a reactive group derived from an amino group or a tetracarboxylic acid at the molecular end by performing the same imidation treatment as that for producing the above-mentioned imidized polymer. Can be synthesized. A partially imidized polymer can be synthesized by reacting these prepolymers under the same conditions as those for the polyamic acid.

<End-modified polymer>
The polyamic acid, the imidized polymer, and the partially imidized polymer may be of a terminal modified type in which the molecular weight is adjusted. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified type can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing the polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can do. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is usually constituted by dissolving and containing at least one polymer selected from the above polyamic acid, imidized polymer, and partially imidized polymer in an organic solvent. As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together.

  The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is It is too small to obtain a good liquid crystal alignment film. When the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent is increased, so that the coating properties tend to be inferior. Moreover, the temperature at the time of preparing the liquid crystal aligning agent of this invention, Preferably, it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound or an epoxy compound from the viewpoint of improving the adhesion to the substrate surface within a range that does not impair the intended physical properties. Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl- , 4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N -Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, etc. can be mentioned. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′, -Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N',-tetraglycidyl-4,4'- Diaminodiphenylmethane, 3- (N-Ariru N Gurishijiru) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) and the like aminopropyltrimethoxysilane.
The blending ratio of these functional silane-containing compounds or epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the polymer.

<Liquid crystal display element>
The liquid crystal display element obtained using the liquid crystal aligning agent of this invention can be manufactured, for example with the following method.
(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, or a printing method, and then the coated surface is heated. Thus, a coating film is formed. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane-containing compound, a functional titanium-containing compound, or the like is previously applied to the surface of the substrate. You can also The heating temperature after application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. In addition, the liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film that becomes an alignment film by removing the organic solvent after coating, but further proceeds with dehydration ring closure by further heating, and is further imidized. It can also be set as a coating film. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.
(2) A rubbing process is performed in which the formed coating film surface is rubbed in a certain direction with a roll wound with a cloth made of a fiber such as nylon, rayon, or cotton. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Further, by partially irradiating the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention with ultraviolet rays as disclosed in, for example, JP-A-6-222366 and JP-A-6-281937. A resist film is partially formed on the surface of the liquid crystal alignment film which has been subjected to a treatment for changing the pretilt angle or a rubbing treatment as disclosed in JP-A-5-107544, which is different from the previous rubbing treatment. The visibility characteristics of the liquid crystal display element can be improved by removing the resist film after performing the rubbing treatment in the direction and changing the liquid crystal alignment ability of the liquid crystal alignment film.
(3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the two substrates are separated by a gap (cell gap) so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. ), And the periphery of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, and the injection hole is sealed. A liquid crystal cell is constructed. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together.

  Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of liquid crystals include nematic liquid crystals such as Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenyl cyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenyl cyclohexane liquid crystals, pyrimidine liquid crystals, dioxanes. Type liquid crystal, bicyclooctane type liquid crystal, cubane type liquid crystal and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Further, as a polarizing plate to be 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 sandwiching and stretching polyvinyl alcohol is sandwiched between cellulose acetate protective films. The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The logarithmic viscosity, the imidization ratio, the storage stability of the liquid crystal aligning agent, the rubbing resistance, and the voltage holding ratio of the produced liquid crystal display element were evaluated by the following methods.
[Logarithmic viscosity]
The value of the logarithmic viscosity (η _ln ) in the present invention was determined by measuring the viscosity at 30 ° C. for a solution having a polymer weight concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent. It is calculated | required by Formula (i). The polyamic acid and polyimide obtained have a logarithmic viscosity (η _ln ) value of preferably 0.05 to 10 dl / g, more preferably 0.05 to 5 dl / g.

[Imidation rate]
After the polyimide was dried under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and 1H-NMR was measured at room temperature using tetramethylsilane as a reference substance, and determined by the formula shown by the following formula (ii).

Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (ii)
A ¹ : Peak area derived from NH group protons (10 ppm)
A ² : Peak area derived from other protons α: Number ratio of other protons to one proton of NH group in polymer precursor (polyamic acid)

[Storage stability of liquid crystal alignment agent]
A liquid crystal aligning agent prepared with a predetermined composition was stored in a storage at −15 ° C. for one month. If the aligning agent after one month was uniformly dissolved, it was evaluated as “◯”.
[Rubbing resistance of liquid crystal alignment film]
A liquid crystal alignment film is formed on a quartz substrate, and a rubbing machine provided with a roll wrapped with a rayon cloth is used to perform rubbing treatment under the two conditions shown in Table 1 below. It was washed with alcohol, and it was visually confirmed whether or not the alignment film was peeled off from the substrate and rubbing scratches were generated.

[Voltage holding ratio of liquid crystal display element]
A voltage of 5 V was applied to the liquid crystal display element with an application time of 60 microseconds and a span of 16.7 milliseconds, and then the voltage holding ratio after 16.7 milliseconds from the release of application was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation.
Synthesis example 1
According to the method described in JP-A-2004-323665, a diamine represented by the following formula (B) was synthesized.

(Wherein Ph represents a phenyl group)

  Subsequently, 10 g (0.0007 mol) of the compound represented by the formula (B) was dissolved in a mixed solution of 780 g (4.5 mol) of epichlorohydrin, 195 g of ethanol and 25 g of water at room temperature, Heat at 4 ° C. for 4 hours. After lowering the solution temperature to 60 ° C., 400 g of 50% aqueous sodium hydroxide solution was added dropwise over 3 hours and left for 30 minutes, and then the residual epichlorohydrin was distilled off under reduced pressure at 65 ° C. and 27 mmHg. 350 g was added, the solution was washed 4 times with 300 g of water, and toluene was distilled off under reduced pressure of 140 ° C. and 29 mmHg to obtain 8.2 g of an epoxy group-containing compound represented by the following formula (C).

(Wherein Ph represents a phenyl group)

Synthesis example 2
2,3,5-tricarboxycyclopentylacetic acid dianhydride 112.09 g (0.5 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 as tetracarboxylic dianhydride (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157.14 g (0.5 mol), p-phenylenediamine 94.62 g as the diamine compound (0.875 mol), 32.02 g (0.1 mol) of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl and 6.43 g (0.01) of the compound represented by the above formula (9) Mol), 2.79 g (0.03 mol) of aniline as a monoamine was dissolved in 4500 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, it was washed with methyl alcohol and dried at 40 ° C. under reduced pressure for 15 hours to obtain 410 g of polyamic acid having a logarithmic viscosity of 0.54 dl / g. 30 g of the resulting polyamic acid was dissolved in 570 g of N-methyl-2-pyrrolidone, 23.4 g of pyridine and 18.1 g of acetic anhydride were added, and dehydration was carried out at 110 ° C. for 4 hours, followed by precipitation, washing, The pressure was reduced to obtain 17.5 g of a polyimide having a logarithmic viscosity of 0.63 dl / g and an imidization ratio of 95% (hereinafter referred to as “polyimide (A-1)”).

Synthesis example 3
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 203.8 g of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound (0.96 mol), 20.91 g (0.04 mol) of the diamine represented by the above formula (16), and the synthesis method was the same as in Synthesis Example 2, and the polyamic acid having a logarithmic viscosity of 0.83 dl / g 380 g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.94 dl / g and an imidization ratio of 90% (this was referred to as “polyimide (A- 2) ") was obtained 16.9 g.

Synthesis example 4
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 51.91 g (0.48 mol) of p-phenylenediamine as a diamine compound, 2,2 Using 101.9 g (0.48 mol) of '-dimethyl-4,4'-diaminobiphenyl and 20.91 g (0.04 mol) of the diamine represented by the above formula (16), the synthesis method is as in Synthesis Example 6. Similarly, 340 g of polyamic acid having a logarithmic viscosity of 0.77 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.80 dl / g and an imidization ratio of 88% (this was referred to as “polyimide (A- 3) ") was obtained.

Synthesis example 5
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 224.17 g (1.0 mol) as tetracarboxylic dianhydride, p-phenylenediamine 106.5 g (0.985 mol) as the diamine compound, The synthetic method was the same as in Synthesis Example 2 using 7.84 g (0.015 mol) of the diamine represented by 16), and 320 g of polyamic acid having a logarithmic viscosity of 0.80 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.89 dl / g and an imidization ratio of 90% (this was referred to as “polyimide (A- 4) ") was obtained.

Synthesis Example 6
1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1, as tetracarboxylic dianhydride, 300.27 g (1.0 mol) of 3-dione, 24.87 g (0.23 mol) of p-phenylenediamine as a diamine compound, 106.69 g (0.75 mol) of 1,3-cyclohexanebis (methylamine), Using 10.46 g (0.02 mol) of the diamine represented by the above formula (16), the synthesis method was the same as in Synthesis Example 2, and 350 g of polyamic acid having a logarithmic viscosity of 0.65 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.69 dl / g and an imidization ratio of 93% (this was referred to as “polyimide (A- 5) ") was obtained 20.7 g.

Synthesis example 7
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 52.45 g (0.485 mol) of p-phenylenediamine as a diamine compound, 1,3 -Using 68.999 g (0.485 mol) of cyclohexanebis (methylamine) and 15.68 g (0.03 mol) of the diamine represented by the above formula (16), the synthesis method was the same as in Synthesis Example 2. 310 g of polyamic acid having a logarithmic viscosity of 0.74 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.76 dl / g and an imidization ratio of 85% (this was referred to as “polyimide (A- 6) ") was obtained.

Synthesis example 8
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 140.12 g of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound (0.66 mol), 1,3-cyclohexanebis (methylamine) 42.68 g (0.3 mol), and 20.91 g (0.04 mol) of diamine represented by the above formula (16) In the same manner as in Synthesis Example 2, 350 g of polyamic acid having a logarithmic viscosity of 0.61 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.74 dl / g and an imidization ratio of 83% (this was referred to as “polyimide (A- 7) ") was obtained 18.0 g.

Synthesis Example 9
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 174.09 g of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound (0.82 mol), 21.34 g (0.15 mol) of 1,3-cyclohexanebis (methylamine), and 15.68 g (0.03 mol) of the diamine represented by the above formula (16). In the same manner as in Synthesis Example 2, 370 g of polyamic acid having a logarithmic viscosity of 0.73 dl / g was obtained. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.81 dl / g and an imidization ratio of 86% (this was referred to as “polyimide (A- 8) ") was obtained 18.5 g.

Synthesis Example 10
224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 198.27 g (1.0 mol) of 4,4′-methylenedianiline as a diamine compound Was used in the same manner as in Synthesis Example 2 to obtain 380 g of polyamic acid having a logarithmic viscosity of 0.75 dl / g. Using 30 g of the obtained polyamic acid, dehydration ring closure, precipitation, washing, and decompression were performed in the same manner as in Synthesis Example 2, and a polyimide having a logarithmic viscosity of 0.78 dl / g and an imidization ratio of 89% (this was referred to as “polyimide (A- 9) ") was obtained.

Synthesis Example 11
2,3,4-tricarboxycyclopentylacetic acid dianhydride 224.17 g (1.0 mol) as tetracarboxylic dianhydride, p-phenylenediamine 54.07 g (0.5 mol) as the diamine compound, 161.41 g (0.5 mol) represented by 16) was dissolved in 4500 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, it was washed with methyl alcohol and dried at 40 ° C. under reduced pressure for 15 hours to give a polyamic acid having a logarithmic viscosity of 0.75 dl / g (referred to as “polyamic acid (B-10)”).
440 g was obtained.

Synthesis Example 12
Using 196.11 g (1.0 mol) of cyclobutanetetracarboxylic dianhydride as the tetracarboxylic dianhydride and 212 g (1.0 mol) of 2,2′-dimethyl-4,4′-diaminobiphenyl as the diamine compound. In the same manner as in Synthesis Example 2, 370 g of polyamic acid having a logarithmic viscosity of 1.54 dl / g was obtained. (This is referred to as “polyamic acid (B-11)”)

Synthesis Example 13
98.06 g (0.5 mol) of cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, 109.06 g (0.5 mol) of pyromellitic dianhydride, 4,4′-methylenedi as a diamine compound Using 198.27 g (1.0 mol) of aniline, the synthesis method was the same as in Synthesis Example 2, and 360 g of polyamic acid having a logarithmic viscosity of 1.28 dl / g was obtained. (This is referred to as “polyamic acid (B-12)”)

Synthesis Example 14
A polyimide prepolymer was synthesized in the same manner as in Synthesis Example 2 except that the monoamine aniline was removed in Synthesis Example 2, and the solid obtained by precipitation and drying was dissolved in N-methyl-2-pyrrolidone to obtain a solid content. A polyimide prepolymer solution having a concentration of 10% by weight was obtained. In addition, a polyamic acid prepolymer was synthesized in the same manner as in Synthesis Example 12 except that 193.17 g (0.985 mol) of cyclobutanetetracarboxylic acid was used in Synthesis Example 12, and the solid substance obtained by precipitation and drying was treated with N. -A polyamic acid prepolymer solution having a solid content of 10% by weight was dissolved in methyl-2-pyrrolidone. Next, 200 g of the polyimide prepolymer solution and 800 g of the polyamic acid prepolymer solution were mixed and stirred for 2 hours, and then the reaction solution was poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, it was washed with methyl alcohol and dried at 40 ° C. under reduced pressure for 15 hours to obtain 95 g of a partially imidized polymer having a logarithmic viscosity of 0.92 dl / g (referred to as “polymer (C-13)”). Obtained.

Example 1
The polyimide (A-1) obtained in Synthesis Example 2 and the polyamic acid (B-11) obtained in Synthesis Example 12 were mixed with N-methyl so that polyimide: polyamic acid = 20: 80 (weight ratio). It is dissolved in a 2-pyrrolidone / γ-butyrolactone mixed solvent (weight ratio 30/70), and 10 parts by weight of the tetraglycidylamine compound represented by the above formula (C) is dissolved in the mixed polymer 100. A solution having a solid content concentration of 4% by weight was stirred for 1 hour, and then the solution was filtered using a filter having a pore size of 1 μm to prepare the liquid crystal aligning agent of the present invention. The storage stability of the obtained liquid crystal aligning agent was evaluated. The results are shown in Table 2. Subsequently, the liquid crystal aligning agent was applied onto a transparent conductive film made of an ITO film provided on one surface of a 1 mm thick glass substrate using a spinner (rotation speed: 2000 rpm, application time: 1 minute), A film having a dry film thickness of 0.05 μm was formed by drying at 200 ° C. for 1 hour. A rubbing machine having a roll in which a rayon cloth was wound around this film was subjected to a rubbing treatment at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / second, and a hair foot pushing length of 0.4 mm. The liquid crystal alignment film-coated substrate was dipped in isopropyl alcohol for 1 minute and then dried on a hot plate at 100 ° C. for 5 minutes. Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film application substrate, the liquid crystal alignment film surfaces are relatively The adhesive was cured by overlapping and pressing. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) is filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Were laminated to prepare a liquid crystal display element. The voltage holding ratio and orientation of the obtained liquid crystal display element were evaluated. A coating film was formed on a transparent conductive film made of an ITO film provided on one surface of a 1 mm glass substrate in the same manner as in the production of the liquid crystal display element, and the rubbing resistance was evaluated. The results are also shown in Table 2.

Examples 2-16 and Comparative Examples 1-2
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the polyimide, polyamic acid or partially imidized polymer shown in Table 2 and the compound represented by the formula (C) in the amount shown in Table 2 were used. A liquid crystal display element was produced using this, and evaluated. The evaluation results are shown in Table 2.

Example 17
The polyamic acid (B-10) obtained in Synthesis Example 11 is dissolved in an N-methyl-2-pyrrolidone / ethylene glycol monobutyl ether mixed solvent (weight ratio 50/50), and represented by the above formula (C). 10 parts by weight of the tetraglycidylamine compound is dissolved in the mixed polymer 100 to obtain a solution having a solid content of 3.5% by weight. After stirring for 1 hour, the solution is filtered using a filter having a pore size of 1 μm. The liquid crystal aligning agent of the invention was prepared. The storage stability of the obtained liquid crystal aligning agent was evaluated. The results are shown in Table 2. Subsequently, the liquid crystal aligning agent is applied onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm using a spinner, and temporarily dried on a hot plate at 80 ° C. for 1 minute. And then dried in a clean oven at 200 ° C. for 1 hour to prepare a transparent electrode substrate having a liquid crystal alignment film having a dry film thickness of 0.05 μm. Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer edges of the pair of transparent electrodes / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, the liquid crystal alignment film The adhesive was cured by overlapping and pressing so that the surfaces were opposed. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Were bonded together to produce a liquid crystal display device, and the voltage holding ratio and orientation of the obtained liquid crystal display device were evaluated. A coating film was formed on a transparent conductive film made of an ITO film provided on one surface of a 1 mm glass substrate in the same manner as in the production of the liquid crystal display element, and the rubbing resistance was evaluated. The results are also shown in Table 2.

Claims (3)

A liquid crystal aligning agent comprising 0.1 to 30 parts by weight of the following component [b] with respect to 100 parts by weight of the following component [a].
[A] Polyamic acid obtained by reacting at least one polymer selected from the following (a) to (d) (a) tetracarboxylic dianhydride and a diamine compound (b) imidized weight of polyamic acid Compound (c) Mixture of polyamic acid and / or imidized polymer (d) Partial imidized polymer of polyamic acid
[B] A tetraglycidylamine compound having the structure of the following formula (A).

(Wherein R ₁ and R ₂ represent a monovalent organic group which may be the same or different, and X represents a divalent organic group) 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-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] -furan-1,3-dione, cyclobutanetetracarboxylic dianhydride, pyromellitic dianhydride obtained by using tetracarboxylic dianhydride containing 1 mol% or more of at least one of [i] The liquid crystal aligning agent of Claim 1 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.