JP2008026891A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent that gives a liquid crystal alignment layer showing a high pretilt angle and having preferable alignment uniformity and excellent image persistence characteristics. <P>SOLUTION: The liquid crystal aligning agent includes a polymer having an amic acid repeating unit, a unit of formula (I-2) and its imidized repeating unit, wherein the proportion of the amic acid repeating unit is 60 to 90 mol% with respect to the total of the amic acid repeating unit and the imidized repeating unit, and the imidized repeating unit contains a specified repeating unit such as formula (A) in the range of 5 to 100 mol%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal alignment agent used for forming a liquid crystal alignment film of a liquid crystal display element and a liquid crystal display element including the liquid crystal alignment film. More specifically, a high pretilt angle can be expressed in a wide temperature range, the alignment uniformity, that is, the pretilt angle uniformity is good, the image sticking property is excellent, and the TN type liquid crystal display element, STN type liquid crystal display element, OCB type The present invention relates to a liquid crystal alignment agent that provides a liquid crystal alignment film suitable for a liquid crystal display element, and a liquid crystal display element including the liquid crystal alignment film.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted 90 degrees from one substrate to the other. A TN type liquid crystal display element having a so-called TN type (Twisted Nematic) liquid crystal cell is known. In addition, an STN (Super Twisted Nematic) type liquid crystal display element 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 having less viewing angle dependency, and a VA (Vertical Alignment). An optically compensated bend (OCB) type liquid crystal display element has been developed which has a small viewing angle dependency and excellent high-speed response of an image screen.
Among these, in the TN type, STN type, IPS type, and OCB type liquid crystal display elements, the alignment of the liquid crystal is usually expressed by a liquid crystal alignment film subjected to a rubbing treatment.

As described in Patent Document 1, in the TN-type and STN-type liquid crystal display elements, it is desirable that the liquid crystal alignment film can exhibit a high liquid crystal pre-tilt angle from the viewpoint of preventing display unevenness due to the occurrence of reverse tilt. .
Further, as described in Patent Document 2, an OCB type liquid crystal display element can also exhibit a high liquid crystal pretilt angle from the viewpoint of preventing a decrease in screen brightness due to a reverse transition from bend alignment to splay alignment. desirable. In consideration of in-vehicle applications, it is desirable that a high pretilt angle can be maintained over a wide temperature range.
In the OCB type liquid crystal display element described in Patent Document 3, a TN type liquid crystal display is used, as is the case with an alignment film SE7942 manufactured by Nissan Chemical Co., Ltd., which is usually used as an alignment film for a TN type liquid crystal display element. The alignment film used for the element can also be used as an alignment film for an OCB type liquid crystal display element.
These alignment film materials that can be used for TN-type, STN-type, and OCB-type liquid crystal display elements that can exhibit a high pre-tilt angle have existed in the past. However, variations in the display screen of the pre-tilt angle occur, resulting in display quality. In many cases, it caused a decline.
From the above situation, there has been a demand for a liquid crystal aligning agent suitable for TN type, STN type, and OCB type liquid crystal display elements that can exhibit a high pretilt angle in a wide temperature range and has a small in-plane variation of the pretilt angle.
JP-A-5-323327 JP 2003-279996 A JP 2004-272112 A

  An object of the present invention is to provide a liquid crystal aligning agent that can provide a liquid crystal alignment film that can exhibit a high pretilt angle, good alignment uniformity, excellent image sticking characteristics, and a stable pretilt angle in a wide temperature range. There is.

  Another object of the present invention is to provide a liquid crystal display device having the liquid crystal alignment film.

  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, a polymer having a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2): The ratio of the repeating unit represented by formula (I-1) to the total of the repeating unit represented by formula (I-1) and the repeating unit represented by formula (I-2) is 60 to 90% by weight. Yes, the repeating unit represented by formula (I-2) is in a range of 5 to 100 mol% of at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (A) to (F). It is achieved by the liquid crystal aligning agent characterized by containing in.

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.

According to the present invention, the above objects and advantages of the present invention are secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning agent which can express a high pretilt angle, has favorable alignment uniformity, and provides the liquid crystal aligning film which is excellent in the image sticking characteristic 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 in this invention contains the polymer which has a repeating unit represented by the said Formula (I-1), and a repeating unit represented by the said Formula (I-2). The polymer may be a mixture of (1) a polyamic acid composed of a repeating unit represented by the above formula (I-1) and a polyimide composed of a repeating unit represented by the above formula (I-2). (2) A polymer in which the repeating unit represented by the above formula (I-1) and the repeating unit represented by the above formula (I-2) are bonded in the same molecule in a random or block form ( Hereinafter, it may also be referred to as “partially imidized polymer”.
The polyamic acid is obtained by ring-opening polyaddition of a tetracarboxylic dianhydride and a diamine compound. Polyimide is usually obtained by dehydrating and ring-closing polyamic acid. The partially imidized polymer can be usually obtained by a method of partially dehydrating and ring-closing polyamic acid or a method of synthesizing a block copolymer by combining an amic acid prepolymer and an imide prepolymer. .

<Polyamic acid>
[Tetracarboxylic dianhydride]
In the above formulas (A), (B), (C), and the following formulas (G), (I), (K), and (M) as repeating units represented by the above formula (I-2) Each of the repeating units has a residue derived from 2,3,5-tricarboxycyclopentylacetic acid dianhydride as a residue derived from tetracarboxylic dianhydride. In order to introduce such a residue, 2,3,5-tricarboxycyclopentylacetic acid dianhydride can be used as a tetracarboxylic dianhydride used for the synthesis of polyamic acid.

(In the formula, R ₁ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ₁ may be the same or different, a is an integer of 1 to 3, and b is 1 to 20) Is an integer.)
The repeating units represented by the above formulas (D), (E), (F), (H), (J), (L) and (N) are all tetracarboxylic dianhydrides. 1,3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan- It has a residue derived from 1,3-dione. In order to introduce such a residue, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5) is used as a tetracarboxylic dianhydride used for the synthesis of polyamic acid. -Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione can be used.

The repeating unit represented by (I-2) is 5 to 100 mol%, preferably at least one repeating unit selected from the group consisting of repeating units represented by the formulas (A) to (F). It contains in the range of 10-90 mol%.
The repeating unit represented by the formula (I-2) is preferably at least one repeating unit selected from the group consisting of repeating units represented by the above formulas (G) to (L), preferably 1 to 20 mol. %, More preferably 2 to 16 mol%.
The repeating unit represented by the formula (I-2) can be used in combination with the two tetracarboxylic dianhydrides together with other tetracarboxylic dianhydrides.

  Such other tetracarboxylic dianhydrides include, for example, butanetetracarboxylic dianhydride, 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, 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-cyclopentane Tet Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane- 2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naft [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-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-dio Xotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic acid Anhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), the following formulas (I) and (II) Aliphatic and alicyclic tetracarboxylic dianhydrides such as compounds represented by:

(Wherein R ² and R ⁴ represent a divalent organic group having an aromatic ring, R ³ and R ⁵ represent a hydrogen atom or an alkyl group, and a plurality of R ³ and R ⁵ 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-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, 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 (anhydro trimellitate), propylene glycol-bis (anhydro trimellitate) 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydride) Trimetrate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (1) to (4) An aromatic tetracarboxylic dianhydride such as a compound represented by These other tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 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, 1,3-dimethyl-1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 5- (2,5-di Oxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic 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-5,8-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), pyromellitic dianhydride, 3,3 ′ , 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, above Of the compounds represented by formula (I), the following formula (5) Of the compound represented by (7) and the compound represented by the above formula (II), the compound represented by the following formula (8) is preferable and particularly preferable from the viewpoint of exhibiting good seizure resistance. 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 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, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-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), pyromerit Examples thereof include acid dianhydrides and compounds represented by the following formula (5).

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) represented by the above formula (I-2) All of the tetravalent organic groups represented by P ² are groups derived from tetracarboxylic dianhydride. These may be the same or different, but preferred examples of P ¹ in the formula (I-1) include groups represented by the following formulas (i) and (ii), for example. It is done. Further preferable examples of P ² in the formula (I-2), for example, include a group having an alicyclic skeleton, the following formula (iii), a group represented by each of (iv) may be mentioned particularly preferably .

(In the formula, X is a halogen atom, a methyl group or an ethyl group, c is 0 to 2, d is an integer of 0 to 5, and e and f are integers of 0 to 4.)
Specific examples of preferred tetracarboxylic dianhydrides in each repeating unit include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, as the tetracarboxylic dianhydride constituting the amic acid unit, , 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, 1,2,4,5- Examples include cyclohexanetetracarboxylic dianhydride and pyromellitic dianhydride. Specific examples of the tetracarboxylic dianhydride constituting the imide unit include alicyclic tetracarboxylic dianhydrides, particularly 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, 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-8-methyl-5 (te Lahydro-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 and the like. Of these, 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 is particularly preferred.

[Diamine compound]
The repeating units represented by the above formulas (A) and (D) as the repeating unit represented by the above formula (I-2) are all residues derived from p-phenylenediamine as a residue derived from a diamine compound. Has a group. In order to introduce such a residue, p-phenylenediamine can be used as a diamine compound used for the synthesis of polyamic acid.
The repeating units represented by the above formulas (B) and (E) as the repeating unit represented by (I-2) are both 2,2′-trifluoromethyl as a residue derived from a diamine compound. It has a residue derived from -4,4'-diaminobiphenyl. In order to introduce such a residue, 2,2′-trifluoromethyl-4,4′-diaminobiphenyl can be used as a diamine compound used for the synthesis of polyamic acid.

In addition, the repeating units represented by the above formulas (C) and (F) as the repeating unit represented by (I-2) are both 2,2-bis (4- Aminophenyl) having residues derived from hexafluoropropane. In order to introduce such a residue, 2,2-bis (4-aminophenyl) hexafluoropropane can be used as a diamine compound used for the synthesis of polyamic acid.
In addition, the repeating unit represented by the formula (I-2) contains at least one repeating unit selected from the group consisting of repeating units represented by the above formulas (A) to (F) within a range of 5 to 100 mol%. In addition to the above three diamine compounds, other diamine compounds can be used within a range that does not impair the conditions contained.

Examples of such other diamine compounds include m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4 ′. -Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5- Diaminonaphthalene, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3, , 4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzo Nzophenone, 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'-dichloro-4,4'-diamino-5,5' -Dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropyl Pyridene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, N, N′-di (4-aminophenyl) -benzidine, N, N′-di (4- Aromatic diamines such as aminophenyl) -N, N′-dimethyl-benzidine;
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 [6.2.1.0 ^2,7 ] -undecylenedimethyl diamine, 4 Aliphatic and cycloaliphatic diamines such as 4,4'-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- 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 Two primary amino groups in the molecule, such as −3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, and compounds represented by the following formulas (III) to (IV) and the primary A diamine having a nitrogen atom other than an amino group;

(Wherein R ⁶ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and Y represents a divalent organic group.)

Wherein Y represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, R ⁷ represents a divalent organic group, and a plurality of Y May be the same or different.)
Mono-substituted phenylenediamines represented by the following formula (V);

(Wherein R ⁸ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁹ represents a steroid skeleton, A monovalent organic group having a group selected from a fluoromethyl group, a fluoro group, a fluoromethoxy group, and a trifluoromethoxy group, or an alkyl group having 6 to 30 carbon atoms.)
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.)
Among these other diamines, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 9,9 -Bis (4-aminophenyl) fluorene, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4 '-Methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 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-diamidine Acridine, N, N′-di (4-aminophenyl) -benzidine, N, N′-di (4-aminophenyl) -N, N′-dimethyl-benzidine, a compound of the above formula (III) Among these, the compound represented by the following formula (14), the compound represented by the following formula (15) among the compounds represented by the above formula (IV), and the compound represented by the above formula (V) Compounds represented by 16) to (23) are preferred.

The repeating unit represented by each of the above formulas (G) and (H) has a residue derived from the diamine represented by the above formula (22) as a residue derived from the diamine compound.
Moreover, the repeating unit represented by each of the above formulas (I) and (J) has a residue derived from the diamine represented by the above formula (16) as a residue derived from the diamine compound.
Moreover, the repeating unit represented by each of the said formula (K) and (L) has a residue derived from the diamine represented by the said Formula (23) as a residue derived from a diamine compound, respectively.
Each of the repeating units represented by the formulas (M) and (N) is a diaminoorganosiloxane represented by the following formula (VI) as a residue derived from a diamine compound;

(In the formula, R ₁ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ₁ may be the same or different, a is an integer of 1 to 3, and b is 1 to 20) Is an integer.)
Examples of the diaminoorganosiloxane include 1,3-bis (1-aminomethyl) -1,1,3,3-tetramethyldisiloxane, 1,3-bis (2-aminoethyl) -1,1,3. , 3-tetramethyldisiloxane, 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, 1,3-bis (4-aminobutyl) -1,1,3 , 3-tetramethyldisiloxane, 1,5-bis (3-aminopropyl) -1,1,3,3,5,5-hexamethyltrisiloxane, 1,3-bis (3-aminopropyl) -1 , 1,3,3-tetraethyldisiloxane, 1,3-bis (3-aminopropyl) -1,1,3,3-tetrapropyldisiloxane, 1,3-bis (3-aminopropyl) -1, 1,3,3-tetraphenyl Siloxane, 1,7-bis (3-aminopropyl) -1,1,3,3,5,5,7,7- such octamethyl cyclotetrasiloxane and the like. These can be used alone or in combination of two or more.

The divalent organic group represented by Q ¹ in the repeating unit (amic acid unit) represented by the above formula (I-1) and the repeating unit (imide unit) Q represented by the above formula (I-2) ^The divalent organic group represented by 2 is a group derived from a diamine compound. These may be the same or different. As the diamine compound constituting the amic acid unit, the above-mentioned diamine compounds used in the synthesis of (I-2) can be used in the same manner, and among these, 4,4′-diaminodiphenyl ether, 4,4′- Diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 3,3′-dimethyl-4,4′-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-bis (4-amino) Phenyl) fluorene, 2,2′-dimethyl-4,4′-diaminobiphenyl, is particularly preferred.

[Synthetic reaction of polyamic acid]
The ratio of the tetracarboxylic dianhydride and the diamine compound used for the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.1 relative to 1 equivalent of the amino group contained in the diamine compound. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.
The synthetic reaction of polyamic acid is preferably carried out in an organic solvent under a temperature condition of -20 to 150 ° C, more preferably 0 to 100 ° C. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. 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. It is preferable that the amount is small.

<Poor solvent>
The organic solvent can be used in combination with an alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, or the like, which is a poor solvent for polyamic acid, 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 and the like.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. Then, the reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure, or the reaction solution is distilled off under reduced pressure with an evaporator to obtain a polyamic acid. Further, the polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating it with a poor solvent, or performing the step of evaporating under reduced pressure with an evaporator 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 of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. By the method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. If the reaction temperature is less than 50 ° C., the dehydration ring-closure reaction does not proceed sufficiently, and if 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. 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.

<Imido group-containing polyamic acid>
The imide group-containing polyamic acid used in the present invention has a structure obtained by partially imidizing the polyamic acid. The preferable imidation ratio in the imide group-containing polyamic acid used in the present invention is 10 to 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 an imide group-containing polyamic acid, (i) a method of synthesizing by partially dehydrating and cyclizing the polyamic acid by heating, (ii) dissolving the polyamic acid in an organic solvent, A method of synthesizing partially dehydrated and cyclized by adding a dehydrating agent and a dehydrating ring-closing catalyst and heating if necessary, or (iii) mixing tetracarboxylic dianhydride, diamine compound and diisocyanate compound. A method of condensing and synthesizing by heating as necessary is used.

In the method (i), the reaction temperature is preferably 300 ° C. or less, more 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. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. It is not limited to these. 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 becomes like this. Preferably it is 0-180 degreeC, More 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, 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 And aromatic diisocyanates such as bets - 2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, diisocyanates represented by the following formula (24) to (27).

  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 is not particularly required for the reaction (iii), and the reaction temperature is preferably 50 to 200 ° C, more preferably 100 to 160 ° C.

<End-modified polymer>
The polyamic acid and the imide group-containing polyamic acid may be of a terminal-modified type whose 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.

<Shear viscosity of polymer>
The shear viscosity value of the polyamic acid and imide group-containing polyamic acid obtained as described above is preferably 5 to 100 mPa · s, more preferably 10 to 40 mPa · s.
The value of shear viscosity in the present invention was measured with a viscometer RE100L manufactured by Toki Sangyo Co., Ltd. at 25 ° C. for a solution having a solid content concentration of 5.0% by weight using N-methyl-2-pyrrolidone as a solvent. did.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving the polymer preferably in an organic solvent. In the polymer constituting the liquid crystal aligning agent of the present invention, the ratio (molar ratio) of the repeating unit represented by the above formula (I-1) to the repeating unit represented by the above formula (I-2). Is preferably 9: 1 to 6: 4, most preferably 7: 3.
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 and the like. Preferably it is the range of 1-10 weight%. 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 film thickness of this coating film is too small. It is difficult 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.
The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.

Examples of the organic solvent 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 dimethyl ether Diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone (DIBK), isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, diisobutyl ketone, Examples thereof include isoamyl propionate and isoamyl isobutyrate. These can be used alone or in admixture of two or more.
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 compound having two or more epoxy groups in the molecule (hereinafter also referred to as “epoxy group-containing compound”).

Examples of the epoxy group-containing 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, 1,6 -Hexanediol 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 ' Preferred examples include diaminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, N, N, -diglycidyl-benzylamine, N, N-diglycidyl-aminomethylcyclohexane and the like. . The content of the epoxy compound 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 specific polymer contained in the alignment agent. Moreover, the liquid crystal aligning agent of this invention may contain the functional silane containing compound. 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.
The blending ratio of these functional silane-containing compounds is preferably 40 parts by weight or less, more preferably 30 parts by weight or less 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, a printing method, an ink jet method, etc. Is heated to form a coating film. 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. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. A metal such as Al or Ag, or an alloy containing these metals can be used for the reflective electrode, but the reflective electrode is not limited thereto as long as it has a sufficient reflectance. When applying the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium-containing compound, or the like is provided on the surface of the substrate in order to further improve the adhesion between the substrate surface and the transparent conductive film or reflective electrode and the coating film. Can also be applied in advance. 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 liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation 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 that 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. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate to the outer surface of a liquid crystal cell, ie, the transparent substrate side 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, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane 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. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate 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 pretilt angle, pretilt angle uniformity, voltage holding ratio, and image sticking in the examples and comparative examples were evaluated by the following methods.

<Pretilt angle of liquid crystal display element>
T.A. J. et al. Scheffer, et. al. , J .; Appl. Phys. , Vol. In accordance with the method described in 19, 2013 (1980), it was measured by a crystal rotation method using He—Ne laser light. At this time, six liquid crystal display elements prepared using the same process and aligning agent were measured, and the average value was obtained by the following formula to obtain the pretilt angle of the liquid crystal display element.

Pretilt angle of liquid crystal display element = (pretilt angle measurement value of first liquid crystal display element + pretilt angle measurement value of second liquid crystal display element + pretilt angle measurement value of third liquid crystal display element + fourth liquid crystal display element Pretilt angle measurement value + fifth liquid crystal display element pretilt angle measurement value + sixth liquid crystal display element pretilt angle measurement value) ÷ 6

<Pretilt angle uniformity of liquid crystal display element>
The standard deviation of the pretilt angle of the liquid crystal display element was obtained by the following formula, and those with a standard deviation within 0.5 were judged good and those with 0.5 or more were judged bad.

(In the formula, σ is a standard deviation, and x is a measured value of the pretilt angle of the first to sixth liquid crystal display elements)

<Voltage holding ratio>
A voltage of 5 V was applied to the liquid crystal display element with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the release of application was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation. The case where the voltage holding ratio was 90% or more was judged as good, and the other cases were judged as bad.

<Bake-in>
A 30 Hz, 2.0 V rectangular wave with 1.0 V DC superimposed on the liquid crystal display element is applied at an ambient temperature of 70 ° C. for 1 hour, and the voltage remaining in the liquid crystal cell immediately after the DC voltage is turned off is flicker-erased. To determine the residual DC voltage. The value of the residual DC is 2V or less regardless of the electrode type constituting the liquid crystal display element, and the case where the difference of the residual DC between each electrode type is 0.5V or less is good, and the case other than that is bad. .

<Pretilt angle stability>
The pretilt angle was measured at an ambient temperature of 80 ° C. A case where the pretilt angle was 70% or more of the value at room temperature was judged good, and a case where the pretilt angle was a value smaller than that was regarded as bad.

"Imidation rate"
After drying the polymer under reduced pressure at room temperature, using a superconducting nuclear magnetic resonance absorber (NMR, manufactured by JEOL Ltd., trade name: EX-90A) in deuterated dimethyl sulfoxide (DMSO-d ₆ ). ¹ H-NMR measurement was carried out using tetramethylsilane as a reference substance. In the obtained data, the imidization ratio was calculated from the ratio of the peak area of protons derived from NH groups in the polymer (around 10 ppm) and the peak area derived from other protons.

Synthesis example 1
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 54.61 g as the diamine compound (0.505 mol), 2,2′-trifluoromethyl-4,4′-diaminobiphenyl 128.09 g (0.4 mol) and 35.07 g (0.08) of the compound represented by the above formula (22) Mol), 1.4 g (0.015 mol) of aniline as a monoamine was dissolved in 1,140 g of N-methyl-2-pyrrolidone, reacted at 60 ° C. for 6 hours, and a shear viscosity of 9% at 5.0 wt%. To obtain a polyamic acid of 7mPa · s. N-methyl-2-pyrrolidone (3256 g), pyridine (316.4 g) and acetic anhydride (408.4 g) were added to the resulting polyamic acid, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure using an evaporator to distill off the catalyst and the solvent. Later, it was diluted with γ-butyrolactone to obtain 4,800 g of a polyimide having a shear viscosity of 10.1 mPa · s at 5.0% by weight and an imidization ratio of 90% (this is referred to as “polyimide (A-1)”). .

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 54.61 g as the diamine compound (0.505 mol), 2,2-bis (4-aminophenyl) hexafluoropropane 133.7 g (0.4 mol) and 41.83 g (0.08 mol) of the compound represented by the above formula (16) Then, 1.4 g (0.015 mol) of aniline as a monoamine was dissolved in 1,170 g of N-methyl-2-pyrrolidone, reacted at 60 ° C. for 6 hours, and a shear viscosity of 10% at 5.0 wt%. A polyamic acid of 2 mPa · s was obtained. N-methyl-2-pyrrolidone (3340 g), pyridine (316.4 g) and acetic anhydride (408.4 g) were added to the resulting polyamic acid, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure using an evaporator to distill off the catalyst and the solvent. Later, it was diluted with γ-butyrolactone to obtain 5,000 g of polyimide having a shear viscosity of 11.2 mPa · s at 5.0% by weight and an imidization ratio of 91% (hereinafter referred to as “polyimide (A-2)”). .

Synthesis example 3
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), 87-05 g of p-phenylenediamine as the diamine compound (0.805 mol), 1,3-bis (3-aminopropyl) 1,1,3,3-tetramethyldisiloxane 24.85 g (0.1 mol) and the compound represented by the above formula (23) 39.58 g (0.08 mol) and 2.79 g (0.03 mol) of aniline as a monoamine were dissolved in 988 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. A polyamic acid having a shear viscosity of 8.3 mPa · s was obtained. N-methyl-2-pyrrolidone (2824 g), pyridine (316.4 g) and acetic anhydride (408.4 g) were added to the resulting polyamic acid, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure using an evaporator to distill off the catalyst and the solvent. Later, it was diluted with γ-butyrolactone to obtain 4,200 g of a polyimide having a shear viscosity of 5.1 mPa · s at 5.0% by weight and an imidization ratio of 96% (hereinafter referred to as “polyimide (A-3)”). .

Synthesis example 4
As a tetracarboxylic dianhydride, 176.50 g (0.9 mol) of cyclobutanetetracarboxylic dianhydride and 212 g (1.0 mol) of 2,2′-dimethyl-4,4′-diaminobiphenyl as a diamine compound were added. -A polyamic acid having a shear viscosity of 17.3 mPa · s at 5.0 wt% (dissolved in a mixed solvent of 500 g of methyl-2-pyrrolidone and 3,150 g of γ-butyrolactone, reacted at 40 ° C for 6 hours) 3,900 g) (referred to as “acid (B-1)”).

Synthesis example 5
100.83 g (0.45 mol) of pyromellitic anhydride as tetracarboxylic dianhydride and 90.66 g (0.45 mol) of cyclobutanetetracarboxylic dianhydride and 2,2′-dimethyl-4 as a diamine compound , 4′-diaminobiphenyl (212 g, 1.0 mol) was dissolved in a mixed solvent of 369 g of N-methyl-2-pyrrolidone and 3,318 g of γ-butyrolactone, and reacted at 40 ° C. for 6 hours. 4,090 g of a polyamic acid having a shear viscosity of 17.7 mPa · s at 5.0% by weight (hereinafter referred to as “polyamic acid (B-2)”) was obtained.

Synthesis Example 6
As the tetracarboxylic dianhydride, 104.70 g (0.48 mol) of pyromellitic anhydride and 94.13 g (0.48 mol) of cyclobutanetetracarboxylic dianhydride were used, and the diamine compound was converted to 4,4′-diaminodiphenylmethane198. .3 g (1.0 mol) was dissolved in a mixed solvent of 357 g of N-methyl-2-pyrrolidone and 3217 g of γ-butyrolactone and reacted at 40 ° C. for 6 hours. 3,950 g of polyamic acid having a shear viscosity of 16.1 mPa · s at 5.0% by weight (hereinafter referred to as “polyamic acid (B-3)”) was obtained.

Comparative Synthesis Example 1
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 97.87 g as the diamine compound (0.905 mol), 41.83 g (0.08 mol) of the compound represented by the above formula (16), and 2.79 g (0.03 mol) of aniline as a monoamine were dissolved in 960 g of N-methyl-2-pyrrolidone. And reacted at 60 ° C. for 6 hours to obtain a polyamic acid having a shear viscosity of 11.2 mPa · s at 5.0% by weight. To the obtained polyamic acid, 2745 g of N-methyl-2-pyrrolidone, 316.4 g of pyridine and 408.4 g of acetic anhydride were added, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure with an evaporator to distill off the catalyst and the solvent. Later, it was diluted with γ-butyrolactone to obtain 4,100 g of a polyimide (referred to as “polyimide (a-1)”) having a shear viscosity of 10.7 mPa · s at 5.0% by weight and an imidization ratio of 93%. .

Comparative 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), 87-05 g of p-phenylenediamine as the diamine compound (0.805 mol), 21.23 g (0.1 mol) of 2,2′-dimethyl-4,4′-diaminobiphenyl, 41.83 g (0.08 mol) of the compound represented by the above formula (16) , 2.79 g (0.03 mol) of aniline as a monoamine was dissolved in 985 g of N-methyl-2-pyrrolidone, reacted at 60 ° C. for 6 hours, and a shear viscosity of 13.3 mPa · s at 5.0% by weight was obtained. Amic acid was obtained. To the obtained polyamic acid, 2,814 g of N-methyl-2-pyrrolidone, 316.4 g of pyridine and 408.4 g of acetic anhydride were added, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure with an evaporator to distill off the catalyst and the solvent. After leaving, diluted with γ-butyrolactone, 4,200 g of polyimide having a shear viscosity of 13.8 mPa · s at 5.0% by weight and an imidization ratio of 91% (referred to as “polyimide (a-2)”) Obtained.

Comparative Synthesis Example 3
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), 2,2'-dimethyl- as the diamine compound 193.72 g (0.9125 mol) of 4,4′-diaminobiphenyl, 41.83 g (0.08 mol) of the compound represented by the above formula (16), and 2.79 g (0.03 mol) of aniline as a monoamine. It was dissolved in 1,184 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a polyamic acid having a shear viscosity of 5.0% by weight and 15.3 mPa · s. N-methyl-2-pyrrolidone (3,384 g), pyridine (316.4 g) and acetic anhydride (408.4 g) were added to the resulting polyamic acid, dehydrated and closed at 110 ° C. for 4 hours, and concentrated under reduced pressure with an evaporator to distill off the catalyst and the solvent. After leaving, diluted with γ-butyrolactone, 5,000 g of polyimide having a shear viscosity of 16.1 mPa · s at 5.0% by weight and an imidization ratio of 94% (hereinafter referred to as “polyimide (a-3)”) Obtained.

Example 1
N-methyl is used so that the polyimide (A-1) obtained in Synthesis Example 1 and the polyamic acid (B-1) obtained in Synthesis Example 5 are polyimide: polyamic acid = 20: 80 (weight ratio). It is dissolved in a mixed solvent of 2-pyrrolidone / γ-butyrolactone / butyl cellosolve (weight ratio 17/71/12) to obtain a solution having a solid content concentration of 3% by weight, and after sufficient stirring, this solution is used with a filter having a pore size of 1 μm. And filtered to prepare a liquid crystal aligning agent of the present invention. 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 about 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 / sec, and a hair foot indentation length of 0.4 mm. The liquid crystal alignment film-coated substrate was subjected to ultrasonic cleaning for 1 minute in ultrapure water and dried in a 100 ° C. clean oven for 10 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 coated 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.) was filled between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to produce a liquid crystal display element. The pre-tilt angle and pre-tilt angle uniformity, voltage holding ratio, and image sticking characteristics of the obtained liquid crystal display element were evaluated. The results are shown in Table 1.

Examples 2-6 and Comparative Examples 1-3
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 1 was used, and a liquid crystal display device was prepared and evaluated. The evaluation results are also shown in Table 1.

Claims (4)

A polymer having a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2), the repeating unit represented by the formula (I-1) and the formula The ratio of the repeating unit represented by the formula (I-1) to the total repeating unit represented by (I-2) is 60 to 90% by weight, and the repeating unit represented by the formula (I-2) is A liquid crystal aligning agent comprising at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (A) to (F) in a range of 5 to 100 mol%.

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 repeating unit represented by the formula (I-2) contains at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (G) to (L) in the range of 4 to 20 mol%. The liquid crystal aligning agent of Claim 1 further contained in.

The repeating unit represented by the formula (I-2) contains at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (M) and (N) in the range of 4 to 20 mol%. The liquid crystal aligning agent according to claim 1 or 2, further comprising:

(In the formula, R ₁ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ₁ may be the same or different, a is an integer of 1 to 3, and b is 1 to 20) Is an integer.) A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.