JP2009229935A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligner which has good coatability and is superior in pretilt angle production, pretilt angle stability, and liquid crystal alignment uniformity. <P>SOLUTION: The liquid crystal aligning agent contains 60 to 90 pts.wt. of polyamic acid and 10 to 40 pts.wt. of imidized polymer which is obtained from: a tetracarboxylic dianhydride including 2,3,5-tricarboxy-cyclopentyl acetic dianhydride and 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione; a diamine including a specific compound represented by 2,4-diamino cholestanyl ether, p-phenylenediamine, and a specific compound representd by bis(aminopropyl) tetramethyl disiloxane; and a monoamine having astraight-chain alkyl group having 4 to 7 carbon atoms. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, the coating property is good, a high pretilt angle can be exhibited in a wide temperature range, the alignment uniformity is good, and it is suitable for a TN liquid crystal display element, an STN liquid crystal display element, or an OCB liquid crystal display element. The present invention relates to a liquid crystal aligning agent that provides a liquid crystal aligning film used for the liquid crystal display and a liquid crystal display device including the liquid crystal aligning film.

  Currently, as a liquid crystal display element, a liquid crystal alignment film is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A so-called TN type (twisted) in which a layer of a nematic liquid crystal having a property is formed into a sandwich cell, and the long axis of liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. A TN liquid crystal display element having a (Nematic) liquid crystal cell is widely known. In addition, an STN (Super Twisted Nematic) type liquid crystal display element capable of realizing a high contrast ratio as compared with a TN type liquid crystal display element, an IPS (In-Plane Switching) type liquid crystal display element with less viewing angle dependency, and a VA (Vertical Alignment). ) Type liquid crystal display elements, OCB (Optical Compensated Bend) type liquid crystal display elements that are less dependent on viewing angle and excellent in high-speed response of an image screen have been developed. Among these, the alignment of liquid crystal molecules in the TN, STN, IPS, and OCB type liquid crystal display elements is generally expressed by a liquid crystal alignment film that has been subjected to a rubbing treatment.

In TN-type and STN-type liquid crystal display elements, it is desirable that the liquid crystal alignment film can exhibit a high pretilt angle from the viewpoint of preventing display unevenness due to the occurrence of reverse tilt (see Patent Document 1).
Also in the OCB type liquid crystal display element, it is desirable that a high pretilt angle can be expressed from the viewpoint of preventing a decrease in screen brightness due to reverse transition from bend alignment to splay alignment (see Patent Document 2). In consideration of in-vehicle applications, it is desired that a high pretilt angle can be maintained over a wide temperature range. In the OCB type liquid crystal display element, a liquid crystal alignment film used for a TN type or STN type liquid crystal display element is diverted. For example, in Patent Document 3, a liquid crystal alignment agent “SE7492” manufactured by Nissan Chemical Co., Ltd. is used. It is used as it is.
As described above, a liquid crystal aligning agent capable of exhibiting a high pretilt angle as a liquid crystal aligning agent that can be used for all of the TN type, STN type, and OCB type liquid crystal display elements has been known. However, the uniformity of the pretilt angle in the display screen is insufficient and the display quality is often insufficient.
Furthermore, from the viewpoint of product yield and the like, improvement in the coating property of the liquid crystal aligning agent is also required.
From the above situation, the coating property is good, a high pretilt angle can be expressed in a wide temperature range, and the in-plane variation of the pretilt angle is small, so that it can be suitably used for TN type, STN type and OCB type liquid crystal display elements. A liquid crystal alignment agent that provides a liquid crystal alignment film is desired.
JP-A-5-323327 JP 2003-279996 A JP 2004-272112 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 T.A. J. et al. Scheffer, et. al. , J .; Appl. Phys. , Vol. 19, 2013 (1980)

An object of the present invention is to provide a liquid crystal alignment film that has good coating properties, exhibits a high pretilt angle, is stable in a wide temperature range, and has good alignment uniformity of liquid crystal molecules. The object is to provide a liquid crystal aligning agent.
Another object of the present invention is to provide a liquid crystal display device having excellent display quality.
Still other objects and advantages of the present invention will become apparent from the following description.

In accordance with the present invention, the above objects and advantages of the present invention are primarily as follows:
(A) 60 to 90 parts by weight of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine, and (B) 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1,3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione With anhydride,
The following formula (D-1)

A compound represented by the following formula (D-2)

And a compound represented by the following formula (D-3)

At least one selected from the group consisting of compounds represented by the formula: p-phenylenediamine and the following formula (DI)

(In the formula (DI), each R is a hydrocarbon group having 1 to 12 carbon atoms, a is an integer of 1 to 3, and b is an integer of 1 to 3, respectively. is there.)
A diamine containing a compound represented by:
10 to 40 parts by weight of an imidized polymer obtained by imidizing a polyamic acid obtained by reacting with a monoamine having a linear alkyl group having 4 to 7 carbon atoms (however, (A) polyamic acid and (B) imidization The total with the polymer is 100 parts by weight.)
It is achieved by a liquid crystal aligning agent containing
The above objects and advantages of the present invention are, secondly,
This is achieved by a liquid crystal display element comprising a liquid crystal alignment film formed from the above liquid crystal aligning agent.

According to the present invention, a liquid crystal alignment film is provided that has good coating properties, exhibits a high pretilt angle, is stable in a wide temperature range, and has good alignment uniformity of liquid crystal molecules. A liquid crystal aligning agent is provided. The liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention can be suitably applied to TN type, STN type and OCB type liquid crystal display elements.
Since the liquid crystal display element of the present invention comprising the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention can exhibit high-quality display performance in a wide temperature range, for example, a desk calculator, a wristwatch, a table clock, a count display It is suitably used for display devices such as plates, word processors, personal computers, and liquid crystal televisions.

The liquid crystal aligning agent of this invention contains (A) polyamic acid and (B) imidized polymer at least.
<(A) Polyamic acid>
(A) A polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine.
[Tetracarboxylic dianhydride]
(A) As tetracarboxylic dianhydride used for the synthesis of polyamic acid, for example, 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 acid Dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxy Pentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b -Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 5-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -7-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-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene -2,3,5,6-tetracarboxylic dianhydride, 3-oxy Bicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxa Tricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, the following formulas (TI) and (T-II)

(In formulas (TI) and (T-II), R ¹ and R ³ each represent a divalent organic group having an aromatic ring, and R ² and R ⁴ each represent a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound represented by each of the following:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-1) to (T-4)

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. These may be used alone or in combination of two or more.
(A) In order to synthesize a polyamic acid, among the above, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3 , 4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-5,8-dimethyl 5- (Tetrahydro-2,5-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, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride Of the anhydrides, compounds represented by the above formula (TI), the following formulas (T-5) to (T-7)

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

By using a tetracarboxylic dianhydride containing at least one selected from the group consisting of the compounds represented by the following (hereinafter referred to as “specific tetracarboxylic dianhydride”), good liquid crystal orientation is expressed. It is preferable from the viewpoint that can be made.
Among the specific tetracarboxylic dianhydrides, in particular, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5 , 9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane- 2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-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, Particularly preferred are 5,8,10-tetraone, pyromellitic dianhydride and the compound represented by the above formula (T-5).
(A) The tetracarboxylic dianhydride used for the synthesis of the polyamic acid preferably contains the above specific tetracarboxylic dianhydride in an amount of 50 mol% or more based on the total amount of the tetracarboxylic dianhydride used. 80 mol% or more, more preferably 95 mol% or more. By using a tetracarboxylic dianhydride containing the specific tetracarboxylic dianhydride in such a range, the (A) polyamic acid has better solubility in an organic solvent described later, and a liquid crystal alignment containing this The agent is preferable because the coating property is further improved.

[Diamine]
(A) Examples of diamines used for the synthesis of 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, 2,2′-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- Limethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2 -Bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10- Loanthracene, 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 (trifluoromethyl) biphenyl, 4,4'-bis [(4-a Roh-2-trifluoromethyl) phenoxy] - aromatic diamines such as octafluoro biphenyl;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic and cycloaliphatic diamines such as 1,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl −3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-di (4-aminophenyl) -benzidine, a compound represented by the above formula (DI), the following formula ( D-II) to (D-IV)

(In formula (D-II), R ⁵ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ represents a divalent organic group. Show.)

(In Formula (D-III), R ⁶ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² represents a divalent organic group, respectively. A plurality of X ² may be the same or different from each other.)

(In the formula (D-IV), R ⁷ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁸ represents a steroid. (A monovalent organic group having a group selected from a skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group, or an alkyl group having 6 to 30 carbon atoms.)
A diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group, such as a compound represented by each of:
The following formulas (D-4) to (D-8)

(Y in the formula (D-7) is an integer of 2 to 12, and z in the formula (D-8) is an integer of 1 to 5.)
And the like, and the like. These diamines can be used alone or in combination of two or more.
(A) In order to synthesize a polyamic acid, among the above, 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-pheny Diisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine) 1,3-bis (aminomethyl) cyclohexane, compounds represented by the above formulas (D-4) to (D-8), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diamino Pyrimidine, 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, among the compounds represented by the above formula (DI), 1,3-bis ( - aminopropyl) - formula of tetramethyldisiloxane, the compound represented by the above formula (D-II) (D-9)

Of the compounds represented by formula (D-III), the following formula (D-10)

Of the compounds represented by formula (D-IV), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2 , 4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, in the above formula (D-1) Compound represented by the above formula (D-2) and the following formulas (D-11) to (D-19)

It is preferable to use a diamine containing at least one selected from the group consisting of the compounds represented by each (hereinafter referred to as “specific diamine”).
(A) The diamine used for the synthesis of the polyamic acid preferably contains 50 mol% or more, more preferably 80 mol% or more, and more preferably 95 mol% of the above-mentioned specific diamine with respect to the total amount of diamine used. It is preferable to include the above.
By using a diamine containing a specific diamine in such a range, the (A) polyamic acid has better solubility in an organic solvent described later, and a liquid crystal aligning agent containing the diamine has further improved coatability. preferable.

[(A) Synthesis of polyamic acid]
(A) A polyamic acid can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine. At this time, at least one selected from the group consisting of an acid monoanhydride, a monoamine, and a monoisocyanate compound, which will be described later, may be reacted together to form a terminal-modified polyamic acid.
(A) The proportion of tetracarboxylic dianhydride and diamine compound used in the polyamic acid synthesis reaction is 1 eq of amino group contained in the diamine compound, and the acid anhydride group of tetracarboxylic dianhydride. Is a ratio of 0.5 to 2 equivalents, more preferably 0.7 to 1.2 equivalents.
(A) The polyamic acid synthesis reaction is preferably -20 to 150 ° C, more preferably 0 to 100 ° C in an organic solvent, preferably 0.1 to 20 hours, more preferably 1 to 1 hour. 10 hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid (A). For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide And aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount (a) of the organic solvent (including the poor solvent when used in combination with the poor solvent described later) is the total amount (b) of the tetracarboxylic dianhydride and the diamine compound, and the total amount of the reaction solution (a + b The amount is preferably 0.1 to 30% by weight with respect to).

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n- Chill ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
When the organic solvent is used in combination with the poor solvent, the proportion of the poor solvent used is appropriately set within the range in which the produced (A) polyamic acid does not precipitate, but is preferably 80% by weight or less based on the total amount of the organic solvent. Yes, more preferably 50% by weight or less, and further preferably 20% by weight or less.

(A) In synthesizing the polyamic acid, a terminal-modified polyamic acid having a controlled molecular weight may be obtained by adding a monoamine, an acid monoanhydride, a monoisocyanate compound or the like to the reaction system.
Here, as a monoamine, the monoamine which has a C4-C7 linear alkyl group, and another monoamine can be mentioned. Examples of the monoamine having a linear alkyl group having 4 to 7 carbon atoms include n-butylamine, n-pentylamine, n-hexylamine, and n-heptylamine. Examples of other monoamines include aniline, cyclohexylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n- Examples include pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, and n-eicosylamine.
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 anhydride, etc .;
Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
These compounds are preferably 20 parts by weight or less, more preferably 10 parts by weight or less, with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when synthesizing (A) polyamic acid. Used in.

  As described above, a reaction solution obtained by dissolving (A) polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, and after the polyamic acid contained in the reaction solution is isolated, it may be used for the preparation of the liquid crystal aligning agent, or the isolated polyamic acid is further purified. In addition, you may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. The polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of evaporating under reduced pressure with an evaporator once or several times.

<(B) Imidized polymer>
The (B) imidized polymer used in the present invention includes 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro A tetracarboxylic dianhydride comprising -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
At least one selected from the group consisting of a compound represented by the above formula (D-1), a compound represented by the above formula (D-2) and a compound represented by the above formula (D-3), p- A diamine containing a phenylenediamine and a compound represented by the above formula (DI);
It is an imidized polymer formed by imidizing a polyamic acid obtained by reacting with a monoamine having a linear alkyl group having 4 to 7 carbon atoms.
[Tetracarboxylic dianhydride]
(B) The tetracarboxylic dianhydride used to synthesize the imidized polymer is at least 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1,3,3a, 4,5,9b-hexahydro Includes -8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione.
(B) The tetracarboxylic dianhydride used for synthesizing the imidized polymer may contain other tetracarboxylic dianhydrides in addition to the two types of tetracarboxylic dianhydrides. As such other tetracarboxylic dianhydrides, (A) those exemplified above as tetracarboxylic dianhydrides used for the synthesis of polyamic acid (however, 2,3,5-tricarboxycyclopentylacetic acid Anhydride and 1,3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1, 3-dione is excluded.).

(B) The tetracarboxylic dianhydride used for synthesizing the imidized polymer is preferably 2,3,5-tricarboxycyclopentylacetic acid dianhydride with respect to the total amount of tetracarboxylic dianhydride. 10 mol% or more, More preferably, it contains 20-80 mol%, More preferably, it contains 30-70 mol%. (B) The tetracarboxylic dianhydride used to synthesize the imidized polymer is 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo -3-furanyl) -naphtho [1,2-c] -furan-1,3-dione is preferably 10 mol% or more, more preferably 20 to 80 mol, based on the total amount of tetracarboxylic dianhydride. %, More preferably 30 to 70 mol%.
By using a tetracarboxylic dianhydride containing each compound in the above range, the (B) imidized polymer has better solubility in an organic solvent to be described later, and the liquid crystal aligning agent containing this is This is preferable because the coatability is further improved.

[Diamine]
(B) The diamine used for synthesizing the imidized polymer is at least a compound represented by the above formula (D-1), a compound represented by the above formula (D-2), and the above formula (D-3). ), At least one selected from the group consisting of compounds represented by formula (I), p-phenylenediamine, and a compound represented by the above formula (D-I).
(B) The diamine used for synthesizing the imidized polymer may contain other diamines in addition to the above diamines. As such other tetracarboxylic dianhydrides, (A) those exemplified above as diamines used for synthesizing polyamic acid (however, in each of the above formulas (D-1) to (D-3)) And the compounds represented by the formula (D-I)). Among these, the compound represented by the above formula (D-18) and the compound represented by the above formula (D-19) are preferable.

(B) The diamine used for synthesizing the imidized polymer is a compound represented by the above formula (D-1), a compound represented by the above formula (D-2), and the above formula (D-3). Preferably, at least one selected from the group consisting of compounds represented by the formula (1) is 0.1 mol% or more, more preferably 1 to 20 mol%, still more preferably 3 to 15 mol, based on the total amount of diamine used. %contains.
(B) The diamine used for synthesizing the imidized polymer is preferably 10 mol% or more, more preferably 20 to 80 mol%, more preferably p-phenylenediamine, based on the total amount of diamine used. Contains 45 to 75 mol%.
In addition, the diamine used for synthesizing the (B) imidized polymer is preferably a compound represented by the above formula (D-I), preferably 1 mol% or more, based on the total amount of the diamine used. Preferably it contains 5-30 mol%, More preferably, it contains 10-20 mol%.
(B) The diamine used for synthesizing the imidized polymer is represented by the compounds represented by the above formulas (D-1) to (D-3), p-phenylenediamine, and the above formula (DI). In addition to the compound, it is preferable to further include at least one selected from the group consisting of the compound represented by the formula (D-18) and the compound represented by the formula (D-19). At least one of them is preferably 0.1 mol% or more, more preferably 1 to 20 mol%, still more preferably 3 to 10 mol% with respect to the total amount of diamine.
By using a diamine containing each compound in the above range, the liquid crystal aligning agent containing the (B) imidized polymer has particularly good alignment uniformity and has a high pretilt angle stably over a wide temperature range. It is preferable because it can be expressed.

(B) In order to synthesize an imidized polymer, a monoamine having a linear alkyl group having 4 to 7 carbon atoms is further used. Specific examples of the monoamine having a linear alkyl group having 4 to 7 carbon atoms include n-butylamine, n-pentylamine, n-hexylamine, and n-heptylamine.
The proportion of the monoamine having a linear alkyl group having 4 to 7 carbon atoms used here is preferably 0.1 mol with respect to the total amount of the diamine used for synthesizing the (B) imidized polymer. % Or more, more preferably 0.5 to 20 mol%, still more preferably 1 to 10 mol%.
Here, a part of the monoamine having a linear alkyl group having 4 to 7 carbon atoms is replaced with at least one selected from the group consisting of other monoamines, acid monoanhydrides and monoisocyanate compounds. May be. Specific examples of other monoamines, acid monoanhydrides, and monoisocyanate compounds are the same as those exemplified as the other monoamines, acid monoanhydrides, and monoisocyanate compounds that can be used in the synthesis of (A) polyamic acid. Other monoamines, acid monoanhydrides and monoisocyanate compounds are used in proportions to the total amount of monoamines having a linear alkyl group having 4 to 7 carbon atoms, other monoamines, acid monoanhydrides and monoisocyanate compounds. Thus, it is preferably 50% by weight or less, more preferably 30% by weight or less, and further preferably 5% by weight or less.
By making these use ratios in the above range, the liquid crystal aligning agent containing the (B) imidized polymer has particularly good alignment uniformity, and a high pretilt angle can be stably expressed in a wide temperature range. Therefore, it is preferable.

[Synthesis of (B) imidized polymer]
(B) The imidized polymer can be obtained by imidizing a polyamic acid obtained by reacting the tetracarboxylic dianhydride, diamine and monoamine as described above. (B) The synthesis | combination of the polyamic acid which is a precursor for synthesize | combining an imidation polymer can be performed according to the synthesis | combining method of above-described (A) polyamic acid.
An imidized imidized polymer can be obtained by dehydrating and ring-closing the polyamic acid. The imidized polymer used in the present invention may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure that the polyamic acid as a precursor had, or only a part of the amic acid structure may be dehydrated and cyclized. Alternatively, it may be a partially imidized product in which an amic acid structure and an imide ring structure coexist.
The (B) imidized polymer contained in the liquid crystal aligning agent of the present invention preferably has an imidization rate of 40% or more, and more preferably 80% or more.
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 1 in an 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. ).

Imidation rate (%) = (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 ( It is the number ratio of other protons to one NH group proton in the polyamic acid).

The polyhydric acid dehydration ring closure reaction is preferably carried out by (i) a method of heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent and adding a dehydrating agent and a dehydration ring closure catalyst to this solution as necessary. It is performed by the method of heating.
The reaction temperature in the method (i) of heating the polyamic acid is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. The reaction time is preferably 0.5 to 20 hours, more preferably 2 to 10 hours. 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 method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 0.5 to 10 hours, more preferably 2 to 6 hours.
In the method (ii), a reaction solution containing (B) an imidized polymer is obtained as described above. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by performing the same operations as described above as the method for isolating and purifying (A) polyamic acid.

-Solution viscosity-
The (A) polyamic acid and the (B) imidized polymer obtained as described above preferably have a solution viscosity of 20 to 800 mPa · s when each is a 10% by weight solution. More preferably, it has a solution viscosity of 30 to 500 mPa · 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.
<Use ratio of (A) polyamic acid and (B) imidized polymer>
The liquid crystal aligning agent of this invention contains both polymers in the ratio of (A) 60-90 weight part of polyamic acids, and (B) imidized polymer 10-40 weight part. This proportion is preferably 60 to 80 parts by weight of (A) polyamic acid and 15 to 40 parts by weight of (B) imidized polymer, more preferably 65 to 75 parts by weight of (A) polyamic acid and (B) imide. 25 to 40 parts by weight of the polymerized polymer. However, in any of the above cases, the total of (A) polyamic acid and (B) imidized polymer is 100 parts by weight.
The liquid crystal aligning agent of the present invention containing both polymers in the above range is preferable because a liquid crystal display element having a liquid crystal alignment film formed using the polymer exhibits a high voltage holding ratio.

<Other additives>
The liquid crystal alignment film of the present invention contains (A) polyamic acid and (B) imidized polymer as essential components as described above, but may contain other components as necessary.
Examples of such other components include a compound having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), a functional silane compound, and the like.
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′-diame Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - such as aminomethyl cyclohexane can be exemplified.
The use ratio of the epoxy compound as described above is preferably the total amount of the polymer (the total amount of (A) polyamic acid and (B) imidized polymer; the same applies hereinafter) to 100 parts by weight. Part or less, more preferably 0.1 to 30 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 2 parts by weight or less, more preferably 0.2 parts by weight or less with respect to 100 parts by weight of the total amount of the polymer.

<Liquid crystal aligning agent>
In the liquid crystal aligning agent of the present invention, (A) polyamic acid and (B) imidized polymer as described above and other additives optionally blended as necessary are preferably dissolved and contained in an organic solvent. Configured.
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 synthesis reaction of (A) polyamic acid can also be selected suitably, and can be used together.

  Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include 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 di Examples thereof include methyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent in the liquid crystal aligning agent to the total weight of the aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 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 On the other hand, it is difficult to obtain a good liquid crystal alignment film because it is too small. On the other hand, 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. As a result, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent of the present invention is applied to a substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal display film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3).
(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 an appropriate application method such as an offset printing method, a spin coating method, or an ink jet printing method, and then A coating film is formed by heating the coated surface. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, alicyclic polyolefin, or the like can be used. Examples of the transparent conductive film provided on one surface of the substrate include 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 ), and the like. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask having a desired pattern in advance when forming the transparent conductive film 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 compound, a functional titanium compound or the like is applied in advance to the surface of the substrate. It may be left. After application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed first for the purpose of preventing dripping of the applied aligning agent. The pre-bake temperature is preferably 30 to 200 ° C., more preferably 40 to 150 ° C., and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.1 to 30 minutes, more preferably 0. .5-10 minutes. And after removing a solvent completely, it is preferable that a heating (post-baking) process is further implemented. This post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 1 to 200 minutes, more preferably 5 to 20 minutes. The liquid crystal aligning agent of the present invention forms a coating film that becomes an alignment film by removing the organic solvent after coating as described above. It may be a coated film.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) The liquid crystal alignment film is subjected to a rubbing treatment in which the coating film surface formed as described above is rubbed in a certain direction with a roll wound with a cloth made of an appropriate fiber such as nylon, rayon, or cotton. It may be used as Furthermore, for the coating film after the rubbing treatment, for example, a part of the liquid crystal alignment film as shown in Patent Document 4 (Japanese Patent Laid-Open No. 6-222366) or Patent Document 5 (Japanese Patent Laid-Open No. 6-281937). Or a part of the surface of the liquid crystal alignment film as disclosed in Patent Document 6 (Japanese Patent Laid-Open No. 5-107544) It is obtained by forming a resist film and then rubbing in a direction different from the previous rubbing process and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities in each region. It is possible to improve the visual field characteristics of the liquid crystal display element.

(3) When two substrates on which the liquid crystal alignment film is formed as described above are prepared and rubbed, the two substrates are aligned so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. The two substrates are placed facing each other with a gap (cell gap) between them, and the peripheral parts of the two substrates are bonded together using a sealing agent, and liquid crystal is injected and filled into the substrate gap and the cell gap defined by the sealing agent. The injection hole is sealed to form a liquid crystal cell. And the liquid crystal display element of this invention can be manufactured by bonding a polarizing plate to the outer surface of a liquid crystal cell, ie, the other surface side of each board | substrate which comprises a liquid crystal cell.
Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl 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.

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 imidation rate of the imidized polymer in the following synthesis examples was measured at room temperature using tetramethylsilane as a reference substance after the imidized polymer was sufficiently dried at room temperature under reduced pressure and then dissolved in deuterated dimethyl sulfoxide. ^It calculated | required by the said Numerical formula (i) from the result of < ¹ > H-NMR.
<(A) Synthesis of polyamic acid>
Synthesis example 1
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 compound 198 g (1.0 mol) of '-diaminodiphenylmethane was dissolved in 230 g of N-methyl-2-pyrrolidone and 2,060 g of γ-butyrolactone, reacted at 40 ° C for 3 hours, and 1,350 g of γ-butyrolactone was added. As a result, about 4,045 g of a solution containing 10% by weight of polyamic acid (A-1) was obtained. The solution viscosity of this solution was 125 mPa · s.
Synthesis example 2
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1 of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound) 0.0 mol) is dissolved in a mixed solvent consisting of 370 g of N-methyl-2-pyrrolidone and 3,300 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours, so that 10 weight of polyamic acid (A-2) is obtained. About 4,078 g of a solution containing% was obtained. The solution viscosity of this solution was 160 mPa · s.

<(B) Synthesis of imidized polymer>
Synthesis example 3
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 76 g (0.70 mol) as the diamine compound , 37 g (0.15 mol) of bisaminopropyltetramethyldisiloxane, 25 g (0.05 mol) of the compound represented by the above formula (D-3) and 13 g of the compound represented by the above formula (D-18) ( 0.05 mol) and 12 g (0.1 mol) of N-heptylamine as a monoamine were dissolved in 1,010 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 9 hours. It was carried out to obtain a solution containing a polyamic acid. A small amount of the resulting polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 15 mPa · s.
Next, 2,740 g of N-methyl-2-pyrrolidone, 158 g of pyridine and 204 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (the pyridine and acetic anhydride used in the imidation reaction were removed from the system by this operation), whereby the imidation rate was about 86. About 2,300 g of a solution containing 15% by weight of imidized polymer (B-1) was obtained. A small amount of this imidized polymer solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 24 mPa · s.

Synthesis example 4
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 76 g (0.70 mol) as the diamine compound , 37 g (0.15 mol) of bisaminopropyltetramethyldisiloxane, 25 g (0.05 mol) of the compound represented by the above formula (D-3) and 15 g of the compound represented by the above formula (D-19) ( 0.05 mol) and 12 g (0.1 mol) of N-heptylamine as a monoamine were dissolved in 1,010 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 9 hours. It was carried out to obtain a solution containing a polyamic acid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 13 mPa · s.
Next, 2,740 g of N-methyl-2-pyrrolidone, 158 g of pyridine and 204 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (the pyridine and acetic anhydride used in the imidation reaction were removed from the system by this operation), whereby an imidization rate of about 85 About 2,300 g of a solution containing 15% by weight of imidized polymer (B-2) was obtained. A small amount of this imidized polymer solution was collected, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 22 mPa · s.

Synthesis example 5
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 70 g (0.65 mol) as the diamine compound , 37 g (0.15 mol) of bisaminopropyltetramethyldisiloxane, 44 g (0.1 mol) of the compound represented by the above formula (D-1) and 13 g of the compound represented by the above formula (D-18) ( 0.05 mol) and 12 g (0.1 mol) of N-heptylamine as a monoamine are dissolved in 1,040 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 9 hours. Performed to obtain a solution containing a polyamic acid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 13 mPa · s.
Next, 2,970 g of N-methyl-2-pyrrolidone, 158 g of pyridine and 204 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (the pyridine and acetic anhydride used in the imidation reaction were removed from the system by this operation), whereby an imidization rate of about 85 About 2,600 g of a solution containing 15% by weight of imidized polymer (B-3) was obtained. A small amount of this imidized polymer solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 19 mPa · s.

Synthesis Example 6
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 70 g (0.65 mol) as the diamine compound , 37 g (0.15 mol) of bisaminopropyltetramethyldisiloxane, 26 g (0.05 mol) of the compound represented by the above formula (D-2) and 13 g of the compound represented by the above formula (D-18) ( 0.05 mol) and 12 g (0.1 mol) of N-heptylamine as a monoamine were dissolved in 1,010 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 9 hours. It was carried out to obtain a solution containing a polyamic acid. A small amount of the resulting polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 15 mPa · s.
Next, 2,890 g of N-methyl-2-pyrrolidone, 158 g of pyridine and 204 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (removing pyridine and acetic anhydride used in the imidation reaction out of the system in this operation) to obtain an imidation ratio of about 87. About 2,700 g of a solution containing 15% by weight of imidized polymer (B-4) was obtained. A small amount of this imidized polymer solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 16 mPa · s.

<Comparative synthesis example of imidized polymer>
Comparative Synthesis Example 1
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 96 g (0.89 mol) as the diamine compound, bis 25 g (0.10 mol) aminopropyltetramethyldisiloxane and 13 g (0.020 mol) 3,6-bis (4-aminobenzoyloxy) cholestane and 8.1 g (0.030 mol) N-octadecylamine as monoamine Is dissolved in 960 g of N-methyl-2-pyrrolidone, reacted at 60 ° C. for 6 hours, and contains polyamic acid. To obtain a liquid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 60 mPa · s.
Next, 2,700 g of N-methyl-2-pyrrolidone, 396 g of pyridine and 409 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (the pyridine and acetic anhydride used in the imidation reaction were removed from the system by this operation), whereby an imidation rate of about 95 About 2,000 g of a solution containing 15% by weight of imidized polymer (b-1) was obtained. A small amount of this imidized polymer solution was collected, and γ-butyrolactone was added to the solution, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 70 mPa · s.

Comparative Synthesis Example 2
2,3,5-Tricarboxycyclopentylacetic acid dianhydride 112.1 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 157.1 g (0.5 mol), p-phenylenediamine 54.6 g as a diamine compound (0.505 mol), 2,2′-trifluoromethyl-4,4′-diaminobiphenyl 128.1 g (0.4 mol) and 35.1 g (0 of the compound represented by the above formula (D-16)) .08 mol) and 1.4 g (0.015 mol) of aniline as a monoamine are dissolved in 1,140 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to contain polyamic acid. To obtain a solution to. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polymer concentration of 10% by weight. The solution viscosity was 24 mPa · s.
Next, 3,256 g of N-methyl-2-pyrrolidone, 316.4 g of pyridine and 408.4 g of acetic anhydride were added to the obtained polyamic acid solution, 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 γ-butyrolactone (removing pyridine and acetic anhydride used in the imidation reaction out of the system in this operation) to obtain an imidation ratio of about 90. About 1,900 g of a solution containing 15% by weight of imidized polymer (b-2) was obtained. A small amount of this imidized polymer solution was collected, and γ-butyrolactone was added to the solution, and the solution viscosity measured as a solution having a polymer concentration of 10% by weight was 70 mPa · s.

Example 1
The solution containing the polyamic acid (A-1) obtained in Synthesis Example 1 and the solution containing the imidized polymer (B-1) obtained in Synthesis Example 3 were mixed with the weight of the polyamic acid and the imidized polymer. They were mixed so as to be 70 parts by weight and 30 parts by weight, respectively, and N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane was added as an epoxy compound to 2 parts per 100 parts by weight in total of the polymer. In addition to parts by weight, γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were added, and the solvent composition was BL: NMP: BC = 71: 17: 12 (weight ratio), solid A liquid crystal aligning agent was prepared by preparing a solution having a partial concentration of 4% by weight and filtering the solution using a filter having a pore diameter of 1 μm.
This liquid crystal aligning agent was evaluated by the following method. The evaluation results are shown in Table 1.
(1) Evaluation of applicability The liquid crystal aligning agent prepared above is printed on a silicon substrate using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd., type “Angstromer”) under the following conditions. Was applied.
Liquid crystal alignment agent discharge amount: 16 g / min Printing pressure: 0.2 mm
Nip pressure: 0.2mm
Next, the coated substrate was pre-baked at 80 ° C. for 1 minute, and then post-baked at 200 ° C. for 10 minutes to form a coating on the substrate. When this coating film is visually observed, if the printing unevenness and pinhole are not seen, the applicability is “good”, and if the printing unevenness and at least one of the pinholes are seen, the applicability is “bad”. evaluated.

(2) Manufacture of liquid crystal cell The liquid crystal aligning agent prepared above was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.). After removing the solvent by heating (pre-baking) for 1 minute on an 80 ° C. hot plate, heating (post-baking) for 10 minutes on a 200 ° C. hot plate to form a coating film having an average film thickness of 600 mm.
The coating film is rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. It was. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
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 substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces are overlapped and pressure bonded. The adhesive was cured. Next, after filling nematic liquid crystal (MLC-6221 manufactured by Merck & Co., Inc.) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.
The above operation was repeated to produce a total of six liquid crystal cells of the same type.
(3) Evaluation of voltage holding ratio For each of the liquid crystal cells manufactured as described above, a voltage of 5 V was applied with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from release of application. Was measured. The average value of the six liquid crystal cells was defined as the voltage holding ratio. As a measuring device, VHR-1 manufactured by Toyo Corporation was used.

(4) Evaluation of pretilt angle Non-patent document 1 (TJ Scheffer, et. Al., J. Appl. Phys., Vol. 19, 2013 (1980)) describes each of the liquid crystal cells produced above. In accordance with the described method, the pretilt angle was measured at room temperature by a crystal rotation method using He—Ne laser light, and the average value was taken as the pretilt angle.
(5) Pretilt angle uniformity The standard deviation of the six pretilt angles measured above was examined. A standard deviation of 0.5 or less was evaluated as “good” pretilt angle uniformity, and a standard deviation exceeding 0.5 was evaluated as “unsatisfactory”.
(6) Stabilization of pretilt angle The pretilt angle was measured in the same manner as in the above (4) except that the measurement temperature was set to 80 ° C for each of the liquid crystal cells produced above. When this value was 70% or more of the measured value at room temperature, the stability of the pretilt angle was evaluated as “good”, and when it was less than 70, the stability was evaluated as “bad”.

Examples 2-7 and Comparative Examples 1 and 2
The evaluation was carried out in the same manner as in Example 1 except that the solutions containing the polymers listed in Table 1 were used as the solutions containing the polymers. The results are shown in Table 1.
In addition, the numerical value in the parenthesis attached | subjected to the polymer in Table 1 is the quantity (weight part) of the polymer contained in the solution used by each Example and the comparative example.

Claims (3)

(A) 60 to 90 parts by weight of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine, and (B) 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 1,3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione With anhydride,
The following formula (D-1)

A compound represented by the following formula (D-2)

And a compound represented by the following formula (D-3)

At least one selected from the group consisting of compounds represented by the formula: p-phenylenediamine and the following formula (DI)

(In formula (DI), R is a C1-C12 hydrocarbon group, a is an integer of 1-3, respectively, and b is an integer of 1-3.)
A diamine containing a compound represented by:
10 to 40 parts by weight of an imidized polymer obtained by imidizing a polyamic acid obtained by reacting with a monoamine having a linear alkyl group having 4 to 7 carbon atoms (however, (A) polyamic acid and (B) imidization The total with the polymer is 100 parts by weight.)
Liquid crystal aligning agent characterized by containing. (B) In the imidized polymer, the diamine used is represented by the compound represented by the above formula (D-1), the compound represented by the above formula (D-2), and the above formula (D-3). 4 to 20 mol% of at least one selected from the group consisting of the above compounds, 5 to 70 mol% of p-phenylenediamine, and 4 to 20 mol% of the compound represented by the above formula (DI). The liquid crystal aligning agent of Claim 1.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.