JP5099346B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

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

Conventionally, a nematic liquid crystal layer having positive dielectric anisotropy between two substrates on which a liquid crystal alignment film containing a polyamic acid or an imidized polymer is formed via a transparent conductive film A liquid crystal having a TN (Twisted Nematic) type or STN (Super Twisted Nematic) type liquid crystal cell in which the long axis of the liquid crystal molecules is continuously twisted by 90 ° or more between the substrates. Display elements are known. A so-called TFT liquid crystal panel in which this TN type liquid crystal display element is operated by driving a TFT is widely used instead of the conventional cathode ray tube. The alignment of the liquid crystal in these liquid crystal display elements is usually realized by a liquid crystal alignment film provided with the alignment ability of liquid crystal molecules by rubbing treatment or the like. As another liquid crystal display element different from the above, a liquid crystal display element having a vertical alignment type liquid crystal cell in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate is known. . Also in such a liquid crystal display element, the alignment control of liquid crystal molecules is usually performed by a liquid crystal alignment film mainly composed of these polymers formed by a liquid crystal alignment agent containing a polymer such as polyamic acid or imidized polymer. It is made by.
In recent years, liquid crystal display elements have been increasing in aperture ratio and resolution in order to obtain brighter and more beautiful images. Therefore, in the TN liquid crystal display element, there is a need for a liquid crystal alignment film that can stably express a pretilt angle higher than that in the past. In addition, a vertical alignment type liquid crystal display element having an excellent viewing angle is widely used for a monitor application and a TV application, but requires a liquid crystal alignment film capable of stably expressing a pretilt angle of about 90 °. The liquid crystal alignment film is usually formed by applying a liquid crystal aligning agent to a substrate with a printing machine and baking it. If the formed liquid crystal alignment film has uneven film thickness, the liquid crystal having this liquid crystal alignment film is formed. Unevenness may appear in the image displayed by the display element. For this reason, a liquid crystal aligning agent excellent in applicability | paintability (especially printability) is calculated | required.

In a liquid crystal alignment film containing a polymer as a main component, it is known that the pretilt angle depends on the substituent of the polymer. For example, Patent Document 1 discloses a polymer obtained by using a monomer having a bulky substituent such as 1-octadecyloxy-2,4-diaminobenzene in a side chain (hereinafter referred to as a pretilt angle developing monomer). It is described that a liquid crystal alignment film containing as a main component expresses a pretilt angle. However, in order to stably express a sufficient pretilt angle using 1-octadecyloxy-2,4-diaminobenzene, it is necessary to use a large amount of this compound. The liquid crystal aligning agent to be used has insufficient printability. Accordingly, there is a problem that a liquid crystal display element including a liquid crystal alignment film formed using the same cannot display a beautiful image.
Patent Document 2 discloses six types of diamines including 4- (4- (4-n-pentylcyclohexyl) cyclohexyl-2,6-difluorophenyl) oxydifluoromethyl-1,3-phenylenediamine. It is described that when these diamines are used in an amount of 90 mol% based on the total amount of diamines used in polymer synthesis, a high pretilt angle can be expressed. However, a liquid crystal aligning agent containing a polymer obtained by using 90 mol% of this diamine has insufficient printability, and a liquid crystal display device having a liquid crystal aligning film formed using this polymer has a beautiful image. There is a problem that it cannot be displayed.
Thus, conventionally, the printability of the liquid crystal aligning agent and the pretilt angle expression of the liquid crystal alignment film to be formed are considered to have a trade-off relationship, and both of them have been demanded.

Patent Documents 3 and 4 describe a liquid crystal aligning agent containing a polyamic acid synthesized using a specific diamine having a steroid skeleton or an imidized polymer thereof. This technique has been made by finding that the above-mentioned specific diamine has an ability to give a polymer that exhibits a high pretilt angle with a relatively small amount of use, and is excellent by a liquid crystal aligning agent containing such a polymer. This is an excellent technique that enables both printability and high pretilt angle expression of the liquid crystal alignment film to be formed. Therefore, a liquid crystal display element comprising a liquid crystal alignment film formed using this liquid crystal aligning agent can display a beautiful image, and the above-described problems of the prior art have been solved.
However, with the advancement of moving image fixing technology, liquid crystal display elements are required to have a finer and more beautiful display, and it has become essential to be able to respond quickly and accurately to the rapid movement of advanced moving images. . For this reason, the step formed on the substrate tends to inevitably increase due to electrotechnical problems, and the improvement in printability at this large step portion is becoming a new important issue for liquid crystal aligning agents. .
JP-A-6-136122 JP 2003-96034 A Japanese Patent No. 2893671 Patent No. 3811985 JP-A-4-281427 JP 2003-321490 A International Publication No. 04/052962 Pamphlet International Publication No. 02/051909 Pamphlet International Publication No. 02/051908 Pamphlet Japanese Patent Laid-Open No. 7-301805 JP-A-8-012759 JP-A-5-043687 JP-A-9-278724 JP 2002-327058 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 T.A. J. et al. Scheffer, et. al. , J. et al. Appl. Phys. , Vol. 19, 2013 (1980)

The present invention has been made based on the above situation.
A first object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal aligning film that has excellent printability even on a substrate having a large step and can stably express a high pretilt angle. It is in.
A second object of the present invention is to provide a liquid crystal display element capable of fine and beautiful display and capable of accurately responding to quick motion of advanced moving images.

As a result of intensive studies to achieve the above object, the present inventors have reached the present invention.
That is, the above objects and advantages of the present invention are as follows.
The following formula (A)

(In Formula (A), A ¹ represents a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, a fluoromethylene group, or a fluoroalkylene group having 2 to 6 carbon atoms, and A ² represents —O— or —COO—. , -OCO -, - NHCO -, - CONH- or -CO- indicates, ^{a 3} represents a monovalent organic group having a steroid skeleton).
And a compound represented by the following formula (B)

(In the formula (B), B ¹ is —O—, —COO—, —OOC—, —CONH— or —NHCO—, and B ² is a biphenyl group, a cyanobiphenyl group, a fluorobiphenyl group, a carbon number of 1 to Fluoroalkoxybiphenyl having a (alkylcyclohexyl) phenyl group having 32 alkyl groups, an alkoxybenzyl group having a C1-C32 alkoxyl group, a dialkoxybenzyl group or an alkoxybiphenyl group, or a C1-C32 fluoroalkoxyl group And b1 and b3 are each 0 or 1, and b2 is an integer of 2 to 22.)
At least one selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a compound represented by the above and a tetracarboxylic dianhydride and an imidized polymer obtained by dehydrating and ring-closing the polyamic acid. This is achieved by a liquid crystal aligning agent containing a polymer.
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.

The liquid crystal aligning agent of the present invention provides a liquid crystal aligning film that has excellent printability even on a substrate having a large step and can stably express a high pretilt angle. The liquid crystal display element of the present invention having such a liquid crystal alignment film can display a fine and beautiful display, and can accurately cope with a quick movement of an advanced moving image.
The liquid crystal display element of the present invention can be effectively used in various devices, and is preferably used as a display device for a desk calculator, a wristwatch, a table clock, a mobile phone, a counting display board, a word processor, a personal computer, a liquid crystal television, and the like. be able to.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention comprises a polyamic acid obtained by reacting a diamine containing a compound represented by the above formula (A) and a compound represented by the above formula (B) with tetracarboxylic dianhydride, and It contains at least one polymer selected from the group consisting of imidized polymers obtained by dehydrating and ring-closing the polyamic acid.
<Diamine>
The diamine used for synthesizing the polyamic acid includes a compound represented by the above formula (A) and a compound represented by the above formula (B).
The alkylene group having 2 to 12 carbon atoms in A ¹ of the above formula (A) is preferably an alkylene group having 2 to 4 carbon atoms, such as 1,2-ethylene group, 1,3-propylene group, 1,4-butylene. Groups are more preferred. As the fluoromethylene group, —CF ₂ — is preferable. The fluoroalkylene group having 2 to 6 carbon atoms is preferably a perfluoroalkylene group having 2 to 4 carbon atoms, such as 1,2-perfluoroethylene group, 1,3-perfluoropropylene group, 1,4-perfluorobutylene. Groups are more preferred.
A ² is preferably —O—.
The steroid skeleton in A ³ refers to a structure composed of a cyclopentano-perhydrophenanthrene nucleus or a structure in which one or more of its carbon-carbon bonds are double bonds. As the monovalent organic group having such a steroid skeleton, those having 17 to 40 carbon atoms are preferable.

  Specific examples of the compound represented by the above formula (A) include, for example, 1-cholesteryloxymethyl-2,4-diaminobenzene, 2-cholesteryloxyethyl-2,4-diaminobenzene, 3-cholesteryloxy. Propyl-2,4-diaminobenzene, 4-cholesteryloxybutyl-2,4-diaminobenzene, 1-cholesteryloxymethyl-3,5-diaminobenzene, 2-cholesteryloxyethyl-3,5-diaminobenzene 3-cholesteryloxypropyl-3,5-diaminobenzene, 4-cholesteryloxybutyl-3,5-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -2,4- Diaminobenzene, 1- (2-cholesteryloxy-1,1,2,2-tetrafluoroethyl) -2,4-diaminobenzene, 1 (3-cholesteryloxy-1,1,2,2,3,3-hexafluoropropyl) -2,4-diaminobenzene, 1- (4-cholesteryloxy-1,1,2,2,3, 3,4,4-octafluorobutyl) -2,4-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -3,5-diaminobenzene, 1- (2-cholesteryloxy) -1,1,2,2-tetrafluoroethyl) -3,5-diaminobenzene, 1- (3-cholesteryloxy-1,1,2,2,3,3-hexafluoropropyl) -3,5 -Diaminobenzene, 1- (4-cholesteryloxy-1,1,2,2,3,3,4,4-octafluorobutyl) -3,5-diaminobenzene, 1-cholestanioxymethyl-2, 4-diaminobenzene, 2-choles Nyloxyethyl-2,4-diaminobenzene, 3-cholestanioxypropyl-2,4-diaminobenzene, 4-cholestanioxybutyl-2,4-diaminobenzene, 1-cholestanioxymethyl-3,5-diaminobenzene 2-cholestanioxyethyl-3,5-diaminobenzene, 3-cholestanioxypropyl-3,5-diaminobenzene, 4-cholestanioxybutyl-3,5-diaminobenzene,

1- (1-cholestanioxy-1,1-difluoromethyl) -2,4-diaminobenzene, 1- (2-cholestanioxy-1,1,2,2-tetrafluoroethyl) -2,4- Diaminobenzene, 1- (3-cholestanioxy-1,1,2,2,3,3-hexafluoropropyl) -2,4-diaminobenzene, 1- (4-cholestanioxy-1,1,2 , 2,3,3,4,4-octafluorobutyl) -2,4-diaminobenzene, 1- (1-cholestanioxy-1,1-difluoromethyl) -3,5-diaminobenzene, 1- ( 2-cholestanioxy-1,1,2,2-tetrafluoroethyl) -3,5-diaminobenzene, 1- (3-cholestanioxy-1,1,2,2,3,3-hexafluoropropyl ) -3,5-Diaminobenze 1- (4-cholestanioxy-1,1,2,2,3,3,4,4-octafluorobutyl) -3,5-diaminobenzene, 3- (2,4-diaminophenylmethoxy)- 4,4-dimethylcholestane, 3- (2- (2,4-diaminophenyl) ethoxy) -4,4-dimethylcholestane, 3- (3- (2,4-diaminophenyl) propoxy) -4, 4-dimethylcholestane, 3- (4- (2,4-diaminophenyl) butoxy) -4,4-dimethylcholestane, 3- (3,5-diaminophenylmethoxy) -4,4-dimethylcholestane, 3- (2- (3,5-diaminophenyl) ethoxy) -4,4-dimethylcholestane, 3- (3- (3,5-diaminophenyl) propoxy) -4,4-dimethylcholestane, 3- (4- (3,5 Diaminophenyl) butoxy) -4,4-dimethylcholestane, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3- (2- ( 2,4-diaminophenyl) -1,1,2,2-tetrafluoromethoxy) -4,4-dimethylcholestane, 3- (3- (2,4-diaminophenyl) -1,1,2,2 , 3,3-hexafluoromethoxy) -4,4-dimethylcholestane, 3- (4- (2,4-diaminophenyl) -1,1,2,2,3,3,4,4-octafluoro Methoxy) -4,4-dimethylcholestane,

3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3- (2- (3,5-diaminophenyl) -1,1,2, 2-tetrafluoromethoxy) -4,4-dimethylcholestane, 3- (3- (3,5-diaminophenyl) -1,1,2,2,3,3-hexafluoromethoxy) -4,4- Dimethylcholestane, 3- (4- (3,5-diaminophenyl) -1,1,2,2,3,3,4,4-octafluoromethoxy) -4,4-dimethylcholestane, 3- ( 2,4-Diaminophenyl) methoxychorane-24-acid hexadecyl, 3- (2- (2,4-diaminophenyl) ethoxy) chorane-24-acid hexadecyl, 3- (3- (2,4-diaminophenyl) Propoxy) colan-24 Acid hexadecyl, 3- (4- (2,4-diaminophenyl) butoxy) cholan-24-acid hexadecyl, 3- (3,5-diaminophenyl) methoxychorane-24-acid hexadecyl, 3- (2- (3 , 5-Diaminophenyl) ethoxy) cholan-24-acid hexadecyl, 3- (3- (3,5-diaminophenyl) propoxy) cholan-24-acid hexadecyl, 3- (4- (3,5-diaminophenyl) Butoxy) cholan-24-acid hexadecyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid hexadecyl, 3- (2- (3,5-diaminophenyl) -1,1,2,2-tetrafluoroethoxy) cholan-24-acid hexadecyl, 3- (3- (3,5-diaminophenyl) -1,1, 2,2,3,3-Hexafluoropropoxy) cholan-24-acid hexadecyl, 3- (4- (3,5-diaminophenyl) -1,1,2,2,3,3,4,4-octa Fluorobutoxy) chorane-24-acid hexadecyl, 3- (3,5-diaminophenylmethoxy) chorane-24-acid stearyl, 3- (2- (3,5-diaminophenyl) ethoxy) chorane-24-acid stearyl, 3- (3- (3,5-diaminophenyl) propoxy) cholan-24-acid stearyl, 3- (4- (3,5-diaminophenyl) butoxy) chorane-24-acid stearyl, 3-((3 5-Diaminophenyl) -1,1-difluoromethoxy) cholan-24-acid stearyl, 3- (2- (3,5-diaminophenyl) -1,1,2,2-tetrafluoro Ethoxy) cholan-24-acid stearyl, 3- (3- (3,5-diaminophenyl) -1,1,2,2,3,3-hexafluoropropoxy) chorane-24-acid stearyl or 3- (4 -(3,5-diaminophenyl) -1,1,2,2,3,3,4,4-octafluorobutoxy) cholan-24-acid stearyl, 1-cholesteryloxy-2,4-diaminobenzene, Examples include cholesteryl 3,5-diaminobenzoate, 1-cholestanioxy-2,4-diaminobenzene, and cholestanyl 3,5-diaminobenzoate.

  Of these, 1-cholesteryloxymethyl-2,4-diaminobenzene, 1-cholesteryloxymethyl-3,5-diaminobenzene, 1- (1-cholesteryloxy-1, 1-difluoromethyl) -2,4-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -3,5-diaminobenzene, 1- (1-cholestanioxy-1,1- Difluoromethyl) -2,4-diaminobenzene, 1- (1-cholestanioxy-1,1-difluoromethyl) -3,5-diaminobenzene, 3- (2,4-diaminophenylmethoxy) -4,4 -Dimethylcholestane, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3- (3,5-dia Nophenylmethoxy) -4,4-dimethylcholestane, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3-((2,4 -Diaminophenyl) methoxy) cholan-24-acid hexadecyl, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid hexadecyl, 3-((3,5-diamino) Phenyl) methoxy) cholan-24-acid hexadecyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid hexadecyl, 3- (2,4-diaminophenylmethoxy) Cholan-24-acid stearyl, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid stearyl, -(3,5-diaminophenylmethoxy) cholan-24-acid stearyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid stearyl, 1-cholesteryloxy Use one or more selected from the group consisting of -2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestanioxy-2,4-diaminobenzene and cholestanyl 3,5-diaminobenzoate Furthermore, among these, from the point of giving a particularly high pretilt angle with a small proportion of use, 1-cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestanioxy Selected from the group consisting of -2,4-diaminobenzene and cholestanyl 3,5-diaminobenzoate It is particularly preferred to use one or more.

The compound represented by the above formula (A) can be obtained, for example, by the method described in Patent Document 5 (JP-A-4-281427) or Patent Document 6 (JP-A 2003-321490).
The liquid crystal aligning agent of this invention contains the polymer which has a repeating structural unit derived from the compound represented by the said formula (A), The liquid crystal aligning property which shows high pretilt angle expression property without impairing printability A membrane can be provided.

B ¹ in the above formula (B) is —O— or —COO— ^* (where a bond marked with “*” is bonded to — ((CH ₂ ) _b2 —) _b3 —B ² ). It is preferable that it is -O-, and it is more preferable.
B ² biphenyl group, a cyanobiphenyl group, fluoro biphenyl group, and fluoroalkoxy group biphenyl, ^B 1 in each 4-position of the biphenyl _{- ((CH 2) b2 -} ) preferably bonded with _b3, these cyano The group, fluoro group and fluoroalkoxyl group are each preferably in the 4 ′ position of biphenyl. The alkylcyclohexyl group of the (alkylcyclohexyl) phenyl group is preferably bonded to the para position of the phenyl group, and the alkyl group is preferably bonded to the 4 ′ position of the cyclohexyl group. The alkoxybenzyl group is preferably a monoalkoxybenzyl group or a dialkoxybenzyl group. In these cases, the alkoxyl group of the monoalkoxybenzyl group is in the para position, and the alkoxyl group of the dialkoxybenzyl group is in the 3,5 position. It is preferable that they are bonded to each other. The number of carbon atoms of the fluoroalkoxyl group of the fluoroalkoxybiphenyl group is preferably 1-6. The number of carbon atoms of the alkyl group of the (alkylcyclohexyl) phenyl group and the alkoxyl group of the alkoxybenzyl group is preferably 5 to 12, respectively.
Two amino groups in the formula (B) _is - in _{((CH 2) b2 -O)} b3 respect -B ² 2, 4-position or 3,5-position _{- (CH} ²⁾ b1 _-B 1 It is preferable.
Specific examples of the compound represented by the formula (B) include, for example, the following formulas (B-1) to (B-15) and (B-17) to (B-22).

The compound represented by each of these can be mentioned. The compounds represented by the above formula (B) are, for example, Patent Documents 7 to 13 (International Publication No. 04/052962 pamphlet, International Publication No. 02/051909 pamphlet, International Publication No. 02/051908 pamphlet, Japanese Patent Application Laid-Open No. Hei 7- No. 301805, JP-A-8-012759, JP-A-5-043687, and JP-A-9-278724) and the like.
The liquid crystal aligning agent of this invention has the outstanding printability by containing the polymer which has a structural unit derived from the compound represented by the said Formula (B).
As the diamine used for synthesizing the polyamic acid, only the compound represented by the above formula (A) and the compound represented by the above formula (B) may be used, or the above formula (A). In addition to the compound represented by formula (B) and the compound represented by the above formula (B), another diamine may be used in combination.
Examples of other diamines that can be used here include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3, 3-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1 , 3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-dia Nobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2 , 2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4, '-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′-diamino-2,2′-dimethylbiphenyl or 4,4′-bis [(4-amino-2-trifluoro Aromatic diamine compounds such as methyl) phenoxy] -octafluorobiphenyl;

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 or cycloaliphatic diamine compounds 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, the following formula (DI)

(In the formula (DI), R ¹ represents a monovalent organic group having a structure selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ represents a divalent organic group. .)
A compound represented by formula (D-II):

(In formula (D-II), R ² represents a divalent organic group having a structure selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² represents a divalent organic group, respectively. Group.)
A diamine compound having two primary amino groups and a nitrogen atom other than the primary amino group in a molecule such as a compound represented by formula:
The following formula (D-III)

(In the formula (D-III), R ³ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ³ may be the same or different, and p represents 1 to 3 respectively. And q is an integer of 1 to 20.)
Diaminoorganosiloxanes such as compounds represented by:
The following formulas (D-1) to (D-7)

(Y in the formula (D-4) is an integer of 2 to 12, and z in the formula (D-5) is an integer of 1 to 5.)
And the like, and the like.
Among these other diamines, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoro Propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4 -Diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), 1,4-bis 4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-diamino-2, 2'-dimethylbiphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, the following among the compounds represented by the above formula (D-I) Formula (D-8)

Of the compounds represented by formula (D-II), the following formula (D-9)

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

At least one selected from the group consisting of a compound represented by formula (D-6) and a compound represented by formula (D-7) (hereinafter referred to as "other specific diamine") It is preferable from the viewpoint of polymerization reactivity when synthesizing a polyamic acid.
The diamine used for synthesizing the polyamic acid preferably contains 0.1 to 50 mol% of the compound represented by the above formula (A) with respect to the total diamine. It is more preferable to contain 1 mol%, especially 1 to 20 mol%. By making the use ratio of the compound represented by the above formula (A) in the above range, the obtained liquid crystal alignment film exhibits excellent coatability, particularly excellent printability, and liquid crystal alignment formed therefrom. This is preferable in that the film exhibits a high pretilt angle more stably. When the proportion of the compound represented by the above formula (A) is in the range of 1 to 5 mol% with respect to the total diamine, the liquid crystal aligning agent of the present invention is particularly suitable for TN type and STN type liquid crystal display elements. Can be used. When the proportion of the compound represented by the above formula (A) is in the range of 10 to 25 mol% with respect to the total diamine, the liquid crystal aligning agent of the present invention is particularly preferably used for a VA liquid crystal display element. it can.
The diamine used for synthesizing the polyamic acid preferably contains 5 to 80 mol%, preferably 10 to 60 mol%, of the compound represented by the formula (B) with respect to the total diamine. More preferably, it is particularly preferable to contain 20 to 50 mol%.
The diamine used to synthesize the polyamic acid preferably contains 10 to 95 mol% of the other specific diamine as described above, more preferably 20 to 90 mol%, based on the total diamine. In particular, it is preferable to contain 40 to 80 mol%.

<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 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-tricarboxyl Cyclopentyl acetic acid dianhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-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-dioxotetrahydrofuranyl) -3 -Methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, the following formula (T -I) and (T-II)

(In formulas (TI) and (T-II), R ⁴ and R ⁶ each represent a divalent organic group having an aromatic ring, and R ⁵ and R ⁷ each represent a hydrogen atom or an alkyl group. And a plurality of R ⁵ and R ⁷ 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′-diphenylsulfone 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′-diphenylmethanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride Anhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4) -Dicarboxyphenoxy ) Diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic 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 ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydride) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), 2,3,4,5-pyridinetetracarboxylic dianhydride, 2,6-bis (3,4-dicarboxyphenyl) pyridine, 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.
Among the above, the tetracarboxylic dianhydrides used to synthesize the polyamic acid are 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 acid dianhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 5- (2,5 -Dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro- , 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, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, The following formula among the compounds represented by the serial formula (T-I) (T-5) ~ (T-7)

And the following formula (T-8) among the compounds represented by formula (T-II):

The liquid crystal alignment film to be formed exhibits good liquid crystal alignment properties when it contains at least one selected from the group consisting of the compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride”). From the viewpoint of doing so, it is preferable. Particularly preferred specific tetracarboxylic dianhydrides are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2 , 3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 3,5,6-tricarboxynorbornane- 2-acetic 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, pyro Lit acid dianhydride and at least one selected from the group consisting of compounds represented by each of the above formulas (T-5) ~ (T-8).
The tetracarboxylic dianhydride used for synthesizing the polyamic acid should contain 80 mol% or more of the specific tetracarboxylic dianhydride as described above with respect to the total tetracarboxylic dianhydride. Preferably, it is more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

<Synthesis of polyamic acid>
The polyamic acid used in the present invention can be synthesized by reacting the tetracarboxylic dianhydride as described above with a diamine.
The ratio of the tetracarboxylic dianhydride used for the reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.5 to 2 equivalents with respect to 1 equivalent of the amino group contained in the diamine. The ratio is preferably, more preferably 0.7 to 1.2 equivalent. It is preferable that the acid anhydride group of the tetracarboxylic dianhydride is in a ratio of 0.5 to 2 equivalents from the viewpoint of easily increasing the degree of polymerization, and more preferably in a ratio of 0.7 to 1.2 equivalents. It is preferable because it is easy to go up.
The polyamic acid may be of a terminal modified type with a controlled molecular weight. By using this terminal-modified polyamic acid, the coating characteristics of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention. Such terminal-modified polyamic acid can be synthesized by adding an appropriate molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing the polyamic acid. .
Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride or n -Hexadecyl succinic anhydride etc. can be mentioned. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n -Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine or n-eicosylamine . Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of these molecular weight modifiers is preferably 20% by weight or less, more preferably 10% by weight or less with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. % By weight or less.

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. The reaction time is preferably 0.5 to 120 hours, more preferably 2 to 10 hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. Preferably there is. In addition, when using together an organic solvent and the poor solvent mentioned later, the usage-amount of the said organic solvent means the total amount of an organic solvent and a poor solvent.
As the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are poor solvents for polyamic acid, can be used in combination as long as the generated polyamic acid 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.
When the organic solvent and the poor solvent are used in combination, the use ratio of the poor solvent is preferably 50% by weight or less, more preferably 20% by weight or less, particularly with respect to the synthesis of the organic solvent and the poor solvent. It is preferable that it is 10 weight% or less.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. 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. Further, 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 distilling under reduced pressure with an evaporator once or several times.

<Imidized polymer>
The imidized polymer used in the present invention can be synthesized by dehydrating and ring-closing the polyamic acid as described above. The polyamic acid is dehydrated and closed by (I) a method in which the polyamic acid is heated, or (II) polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydrating ring-closing catalyst are added to this solution and heated as necessary. It can be done by a 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. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 1 to 120 hours, more preferably 2 to 30 hours.
In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution of (II) above, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. . The amount of the dehydrating agent used is preferably 0.01 to 20 mol relative to 1 mol of the polyamic acid repeating unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. 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. And the reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. The reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

The imidized polymer obtained in the above method (I) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (II), a reaction solution containing an imidized polymer is obtained. 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 the polyamic acid.
The imidized polymer used in the present invention may be a completely imidized product in which all of the amic acid structure of the polyamic acid as a precursor thereof is dehydrated and cyclized, or only a part of the amic acid structure is dehydrated. The ring may be closed and the amic acid structure and the imide ring may coexist.
The imidation ratio in the imidized polymer is preferably 1 to 100%, more preferably 10 to 98%, and further preferably 40 to 90%. Here, the “imidization rate” is a numerical value representing the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide rings in the polymer as a percentage. At this time, a part of the imide ring may be an isoimide ring. The imidization rate can be arbitrarily controlled by adjusting the reaction conditions of the dehydration ring-closing reaction.

<Solution viscosity of polyamic acid and imidized polymer>
The polyamic acid and the imidized polymer used in the present invention preferably have a solution viscosity of 20 to 800 mPa · s, when the solution has a concentration of 10% by weight, and preferably has a solution viscosity of 30 to 500 mPa · s. More preferably, it has a solution viscosity.
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, N-methyl-2-pyrrolidone, γ-butyrolactone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of the specific polyamic acid and the imidized polymer as described above, but is optional as long as the effects and advantages of the present invention are not impaired. May contain other components. 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 may be mentioned as preferred. The blending ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the polymer.

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 polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving the polymer as described above and other components optionally used, preferably dissolved in an organic solvent.
As an organic solvent which can be used for the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned. The poor solvents exemplified as those that can be used together in the synthesis reaction of the polyamic acid may be appropriately selected and used in combination.
Particularly preferred organic solvents that can be used in the liquid crystal aligning agent of the present invention include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethyl Examples include lenglycol dimethyl 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.
A particularly preferable solvent composition is a composition obtained by combining the above-mentioned solvents, wherein no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 25 to 40 mN / m. It is.

The solid 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 liquid crystal aligning agent) is selected in consideration of viscosity, volatility, and the like. Preferably it is the range of 1-10 weight%. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface, and then the solvent is removed to form a coating film that becomes a liquid crystal aligning film, but the solid content concentration is less than 1% by weight. The film thickness of this coating film is too small to obtain a good liquid crystal alignment film, and when the solid content concentration exceeds 10% by weight, the film thickness of the coating film is too large to be equally good liquid crystal. It is difficult to obtain an alignment film, and the viscosity of the liquid crystal aligning agent is increased, which may result in poor coating characteristics, which is not preferable.
The particularly preferable range of the solid content concentration 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 inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at 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 alignment film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following methods (1) to (3).
(1) The liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of a substrate provided with a patterned transparent conductive film by an appropriate application method such as a roll coater method, a spinner method, a printing method, an ink jet method, or the like. Then, the coated surface is formed by heating the coated surface.
Examples of the substrate include glass such as float glass and soda glass, and a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin).
As the transparent conductive film, a NESA film made of SnO _{2 or} an ITO film made of In ₂ O ₃ —SnO ₂ can be used. In order to form these patterned transparent conductive films, a method of forming a pattern by a photo-etching method after forming a transparent conductive film without a pattern, and a mask having a desired pattern when forming the transparent conductive film A method of directly forming a patterned transparent conductive film by using the above can be used.
When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate and the transparent conductive film and the coating film, a functional silane compound, titanate or the like is previously applied on the substrate and the transparent conductive film. Also good.

The heating temperature after applying the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The heating time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The liquid crystal aligning agent of the present invention forms a coating film that becomes a liquid crystal aligning film by removing the organic solvent after coating as described above. The polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid. Alternatively, in the case of an imidized polymer having both an imide ring structure and an amic acid structure, the film may be further heated after the formation of the coating film so that the dehydration ring-closing reaction proceeds to form a more imidized coating film.
The thickness of the coating film to be formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm, as the thickness after removal of the solvent.
In the case where the liquid crystal display element to which the liquid crystal aligning agent of the present invention is applied is a VA type liquid crystal display element, for example, a projecting structure as described in Patent Document 14 (Japanese Patent Application Laid-Open No. 2002-327058). A viewing angle characteristic may be improved by applying a liquid crystal aligning agent after forming an object on a substrate.
(2) Although the coating film formed as described above can be used as it is as a liquid crystal alignment film of a VA liquid crystal display element, a rubbing treatment described below may be performed as necessary.
When the coating film is used as a liquid crystal alignment film of a TN type or STN type liquid crystal display element, a cloth made of fibers such as nylon, rayon, and cotton is wound around the coating surface formed as described above. A rubbing process in which the roll is rubbed in a certain direction is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. The liquid crystal alignment film formed as described above is partially irradiated with ultraviolet rays as disclosed in, for example, Patent Document 15 (Japanese Patent Laid-Open No. 6-222366) and Patent Document 16 (Japanese Patent Laid-Open No. 6-281937). The resist film is partially formed on the surface of the liquid crystal alignment film which has been subjected to a treatment that changes the pretilt angle by irradiating the surface or a rubbing treatment as disclosed in Japanese Patent Laid-Open No. 5-107544. The field-of-view characteristics of the liquid crystal display element are obtained by removing the resist film after performing the rubbing process in a different direction from the previous rubbing process and changing the liquid crystal alignment ability of the liquid crystal alignment film. It is possible to improve.

(3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the two substrates are arranged to face each other with a gap (cell gap) therebetween. The peripheral portions of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled into the cell gap defined by the substrate surface and the sealant, and the injection hole is sealed to form a liquid crystal cell. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate to each outer surface of a liquid crystal cell, ie, both transparent substrate sides, respectively. 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, these liquid crystals include chiral cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate, and trade names “C-15” and “CB-15” (manufactured by Merck). You may add and use an agent.
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” is sandwiched between cellulose acetate protective films that absorbs iodine while stretching and aligning polyvinyl alcohol. The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
In the following synthesis examples, the solution viscosity of the polymer and the imidization rate of the imidized polymer were evaluated by the following methods, respectively.
[Solution viscosity of polymer]
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type viscometer for each polymer solution.
[Imidation rate of imidized polymer]
The imidized polymer was dried under reduced pressure at room temperature, dissolved in deuterated dimethyl sulfoxide, and obtained from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference substance, and the following formula (i) was used.

Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (i)

A ¹ : Peak area derived from protons of NH group appearing near 10 ppm A ² : Peak area derived from other protons α: Other protons relative to one proton of NH group in the precursor (polyamic acid) of imidized polymer Number ratio

Synthesis Example 1 (Synthesis of imidized polymer A1)
125,5 (0.50 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and the above formula (B-1) as diamine 147 g (0.24 mol) of the compound represented by formula (1), 26 g (0.24 mol) of p-phenylenediamine and 10.4 g (0.02 mol) of cholestanyl 3,5-diaminobenzoate were mixed with N-methyl-2-pyrrolidone. It melt | dissolved in 1,230g and reacted at 60 degreeC for 6 hours. A small amount of the obtained polyamic acid solution was taken, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 50 mPa · s.
Next, 1,900 g of γ-butyrolactone was added to the obtained polyamic acid solution, 80 g of pyridine and 100 g of acetic anhydride were added, and a 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 dehydration cyclization reaction were removed from the system in this operation), whereby an imidization rate of about 80 About 1,900 g of a solution containing 15% by weight of imidized polymer A1 was obtained. A small amount of this solution was taken, diluted with γ-butyrolactone, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 40 mPa · s.
Synthesis Examples 2-8, Comparative Synthesis Examples 1-6 (Synthesis of imidized polymers A2-A8 and comparative imidized polymers R1-R6)
Contains imidized polymers A2 to A8 and comparative imidized polymers R1 to R6 in the same manner as in Synthesis Example 1 except that the types and amounts of diamine and tetracarboxylic dianhydride described in Table 1 were used. Each solution was obtained. Table 1 shows the imidization ratio of each imidized polymer.
In Table 1, “compound (A)” and “compound (B)” mean the compound represented by the above formula (A) and the compound represented by the above formula (A), respectively. Each of the abbreviations has the following meaning, and the unit of “amount” of each compound is mol. In Comparative Synthesis Examples 1 to 6, two other diamines were used.
<Diamine>
[Compound represented by the above formula (A)]
b1: Cholestanyl 3,5-diaminobenzoate b2: 1-cholestanioxy-2,4-diaminobenzene [compound represented by the above formula (B)]
b3: The compound represented by the above formula (B-1) b4: The compound represented by the above formula (B-2) b5: The compound represented by the above formula (B-3) b6: The above formula (B-7) B7: Compound represented by the above formula (B-9) b8: Compound represented by the above formula (B-11) b9: Compound represented by the above formula (B-17) b10: Compound represented by the above formula (B-21) [other diamine]
b11: 1-octadecyloxy-2,4-diaminobenzene b12: Paraphenylenediamine <tetracarboxylic dianhydride>
a1: 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride a2: 2,3,5-tricarboxycyclopentylacetic acid dianhydride

<Preparation of liquid crystal aligning agent>
Imide containing 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane as an epoxy compound in the solution containing the imidized polymer A1 obtained in Synthesis Example 1 in the polymer solution 5 parts by weight with respect to 100 parts by weight of the polymer A1, and further γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve were added, and the solvent composition was γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = The solution was 71:17:12 (weight ratio) and the solid concentration was 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
Various evaluation was performed as follows using this liquid crystal aligning agent.
<Evaluation of printability>
The liquid crystal aligning agent prepared above was applied to a liquid crystal alignment film printer (Nissha Printing Co., Ltd.) on a transparent electrode surface of a glass substrate with a transparent electrode in which ITO films having a thickness of 200 nm and a width of 20 μm were formed in stripes at intervals of 100 μm. The film was formed by heating at 80 ° C. for 1 minute. When this coating film was observed with an optical microscope having a magnification of 20 times, the step portion of the substrate was uniformly coated, no defects were observed in the coating film, and the printability was good.
<Manufacture of liquid crystal cells>
The liquid crystal aligning agent prepared above was applied onto the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by spin coating, then heated on an 80 ° C. hot plate for 1 minute, and then a 200 ° C. hot plate. By heating for 10 minutes above, a coating film having an average film thickness of 600 mm was formed. 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, and a liquid crystal is applied to the coating film. Orientation ability was imparted. Next, the substrate having this coating film is subjected to ultrasonic cleaning for 1 minute in ultrapure water, and further dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film on the transparent electrode. Obtained. This operation was repeated to manufacture a pair (two) of substrates having a liquid crystal alignment film on the transparent electrode surface.
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, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. .
<Measurement of pretilt angle>
About the liquid crystal cell manufactured above, in accordance with the method described in Non-Patent Document 1 (T. J. Scheffer, et. Al., J. Appl. Phys., Vol. 19, 2013 (1980)). When the pretilt angle was measured by a crystal rotation method using -Ne laser light, the pretilt angle was as high as 5 °.

Examples 2-8 and Comparative Examples 1-6
A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 1 except that the type of polymer contained in the polymer solution used was as shown in Table 2. The evaluation results are shown in Table 2.
In addition, in evaluation of the printability of Comparative Examples 1 to 6 in Table 2, liquid repellency occurred at the level difference portion of the substrate, and there was a portion where no coating film was formed. I decided.

  As apparent from the above examples, the liquid crystal alignment of the present invention containing a polymer synthesized using a diamine containing a compound represented by the above formula (A) and a compound represented by the above formula (B). The liquid crystal alignment film formed exhibited a high pretilt angle while the agent exhibited excellent printability (Examples 1 to 8). On the other hand, in Comparative Examples 1 to 6 using 1-octadecyloxy-2,4-diaminobenzene in place of the compound represented by the above formula (A), the results are all inferior to the printability of the liquid crystal aligning agent. It was.

Claims (4)

The following formula (A)

(In Formula (A), A ¹ represents a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, a fluoromethylene group, or a fluoroalkylene group having 2 to 6 carbon atoms, and A ² represents —O— or —COO—. , -OCO -, - NHCO -, - CONH- or -CO- indicates, ^{a 3} represents a monovalent organic group having a steroid skeleton).
And a compound represented by the following formula (B)

(In the formula (B), B ¹ is —O—, —COO—, —OOC—, —CONH— or —NHCO—, and B ² is a biphenyl group, a cyanobiphenyl group, a fluorobiphenyl group, a carbon number of 1 to Fluoroalkoxybiphenyl having a (alkylcyclohexyl) phenyl group having 32 alkyl groups, an alkoxybenzyl group having a C1-C32 alkoxyl group, a dialkoxybenzyl group or an alkoxybiphenyl group, or a C1-C32 fluoroalkoxyl group And b1 and b3 are each 0 or 1, and b2 is an integer of 2 to 22.)
At least one selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a compound represented by the above and a tetracarboxylic dianhydride and an imidized polymer obtained by dehydrating and ring-closing the polyamic acid. A liquid crystal aligning agent comprising a polymer.
  The liquid crystal aligning agent of Claim 1 whose ratio of the compound represented by the said Formula (A) in the said diamine is 0.1-50 mol%.   The compounds represented by the above formula (A) are 1-cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestanioxy-2,4-diaminobenzene and 3,5. The liquid crystal aligning agent according to claim 1 or 2, which is at least one selected from the group consisting of cholestanyl diaminobenzoate.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.