JP4788890B2 - 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 is formed between two substrates on which a liquid crystal alignment film made of polyamic acid or polyimide is formed via a transparent conductive film. A liquid crystal display element having a TN (Twisted Nematic) type or STN (Super Twisted Nematic) type liquid crystal cell in which the major axis of the liquid crystal molecules is continuously twisted by 90 degrees or more between substrates in a sandwich structure. Are known. A so-called TFT liquid crystal panel in which this TN type liquid crystal display element is operated by TFT driving 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. . In such a liquid crystal display element, the alignment control of the liquid crystal is usually performed by a liquid crystal alignment film formed of a liquid crystal alignment agent containing a polymer such as polyamic acid or polyimide.

In recent years, liquid crystal display elements have been increasing in aperture ratio and resolution in order to obtain brighter and more beautiful images. For example, in a TN liquid crystal display element, a liquid crystal alignment film capable of stably expressing a pretilt angle higher than that in the prior art is required.
In addition, the 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 degrees. 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 a film thickness unevenness, a liquid crystal display element having the liquid crystal alignment film can be obtained. Unevenness may appear in the displayed image. For this reason, the liquid crystal aligning agent excellent in applicability | paintability is calculated | required.

As disclosed in Patent Document 1, the pretilt angle is a monomer having a bulky substituent such as 1-octadecyloxy-2,4-diaminobenzene in the side chain (hereinafter referred to as a pretilt angle expressing monomer). Expressed by introduction into the polymer. The pretilt angle greatly depends on the amount of the monomer introduced, and even if the amount is the same, the pretilt angle expressed changes when the side chain structure changes.
1-octadecyloxy-2,4-diaminobenzene has a low ability to develop a pretilt angle, and in order to stably develop a pretilt angle as high as 90 degrees, it is necessary to significantly increase the amount of monomer introduced. For this reason, the liquid crystal aligning agent formed using the obtained polymer has insufficient printability, and the liquid crystal display device including the liquid crystal aligning film formed using the polymer displays a beautiful image. There was a problem that could not.

  Furthermore, Patent Document 2 discloses six types of diamines including 4- (4- (4-n-pentylcyclohexyl) cyclohexyl-2,6-difluorophenyl) oxydifluoromethyl-1,3-phenylenediamine. In addition, it is described that a high pretilt angle can be exhibited when 90 mol% is introduced with respect to the total amount of diamine. However, a liquid crystal aligning agent containing a polymer obtained by using this diamine has insufficient printability, and a liquid crystal display device having a liquid crystal aligning film formed using this diamine displays a beautiful image. There was a problem that could not.

On the other hand, cholesteryl 3,5-diaminobenzoate and stearyl lithocholic acid (3,5-diaminobenzoate) disclosed in Patent Document 3 have the ability to develop a high pretilt angle. A coalescence can be obtained, and a liquid crystal aligning agent produced using this polymer can exhibit excellent printability. Therefore, a liquid crystal display element comprising a liquid crystal alignment film formed using this liquid crystal aligning agent can display a beautiful image.
JP-A-6-136122 JP 2003-96034 A Japanese Patent No. 2893671

However, liquid crystal display elements are required to have a finer and more beautiful display, and it has become essential to be able to handle moving images.
For this reason, the level | step difference formed on a board | substrate becomes larger and the printability is becoming inadequate with the conventional liquid crystal aligning agent.
The present invention has been made based on the above situation.

  The first object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal alignment film capable of stably expressing a high pretilt angle and having excellent printing characteristics even on a substrate having a large step. There is to do.

  A second object of the present invention is to provide a liquid crystal display element capable of displaying a beautiful image.

  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.
Formula (I)

And the following formula (II)

Here, R ¹ and R ³ are each independently a divalent organic group from which two amino groups have been removed from a diamine, and R ² and R ⁴ are each independently, from a tetracarboxylic acid to four carboxyls. A tetravalent organic group from which a group has been removed, and m and n are positive integers, provided that at least one of R ¹ and R ³ is represented by the following formula (III):

Here, C is a monovalent organic group having a steroid skeleton, A is may have a halogen atom as a substituent is an alkylene group having 2 to 4 carbon methylene or carbon, B is d ether bond group An organic group represented by
Characterized in that it contains a polymer containing at least one repeating unit selected from the group consisting of repeating units represented by each of the above (limited to polymers having an organic group represented by formula (III)). This is achieved by the liquid crystal aligning agent.

In addition, according to the present invention, the above object and advantage of the present invention are secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the above liquid crystal aligning agent.

The liquid crystal aligning agent of this invention has favorable printability, and can form the liquid crystal aligning film which expresses a high pretilt angle stably.
The liquid crystal display element using the liquid crystal aligning agent of the present invention can be suitably used for a vertical alignment type liquid crystal display element, and by selecting a liquid crystal to be used, an IPS (In-Plane Switching) type, TN type, STN It can also be suitably used for liquid crystal display elements of type, ferroelectric and antiferroelectric properties.
Furthermore, the liquid crystal display element having the liquid crystal alignment film of the present invention can be used effectively in various devices, for example, in display devices such as desk calculators, watches, clocks, coefficient display boards, word processors, personal computers, and liquid crystal televisions. .

Preferred embodiments of the invention

Hereinafter, the present invention will be described in detail. The liquid crystal aligning agent of this invention contains the repeating unit represented by the said Formula (I) and / or the repeating unit represented by the said Formula (II). The repeating unit represented by the above formula (I) can be obtained by reacting and polymerizing tetracarboxylic dianhydride and a diamine compound in an organic solvent. Further, the polymer having the repeating unit represented by the formula (I) thus obtained is subjected to dehydration ring-closing imidization, whereby the repeating unit represented by the above formula (I) is represented by the above formula (II). Can be obtained.
R ¹ in the repeating unit represented by the above formula (I) and R ³ in the repeating unit represented by the above formula (II) are divalent organic groups obtained by removing two amino groups from the diamine, and R ^At least one of ¹ and R ³ is an organic group represented by the above formula (III).
Specific examples of the organic group having a steroid skeleton represented by C in the above formula (III) include structures represented by the following formulas (III-1) to (III-4).

In Formula (III-4), R ⁰ represents a monovalent organic group having an alkyl group having 1 to 20 carbon atoms or an alicyclic skeleton, which may be substituted with a halogen atom.
The diamine compound having an organic group having a steroid skeleton represented by the above formula (III) may be hereinafter referred to as “specific diamine compound”.

Specific examples of the specific diamine include, for example, 1-cholesteryloxymethyl-2,4-diaminobenzene, 2-cholesteryloxyethyl-2,4-diaminobenzene, 3-cholesteryloxypropyl-2,4-diamino. Benzene, 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-choles Ryloxy-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-cholestanioxyethyl-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- Cholestaniloxybutyl-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-Koresutanirokishi -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-octafluoromethoxy) -4,4-dimethylcholestane, 3- ( 1- (3,5-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3- (2- (3,5-diaminophenyl) -1,1,2,2-tetra Fluoromethoxy) -4,4-dimethylcholestane, 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) cholan-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) cholan-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) chorane-24-acid hexadecyl, 3- (4- (3,5-Diaminophenyl) -1,1,2,2,3,3,4,4-octafluorobutoxy) cholan-24-acid hexadecyl, 3- (3,5-diaminophenylmethoxy) Cholan-24-acid stearyl, 3- (2- (3,5-diaminophenyl) ethoxy) chorane-24-acid stearyl, 3- (3- (3,5-diaminophenyl) propoxy) chorane-24 Stearyl 3- (4- (3,5-aminophenyl) butoxy) 24-oic 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, 3- (4 -(3,5-diaminophenyl) -1,1,2,2,3,3,4,4-octafluorobutoxy) cholan-24-acid stearyl.

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-diaminophenylmethoxy) -4,4 Dimethylcholestane, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) -4,4-dimethylcholestane, 3-((2,4-diaminophenyl) methoxy) chorane-24 -Acid hexadecyl, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid Hexadecyl, 3-((3,5-diaminophenyl) methoxy) cholan-24-acid Hexadecyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) cholan-24-acid hexadecyl,
3- (2,4-diaminophenylmethoxy) cholan-24-acid stearyl, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid stearyl, 3- (3 , 5-Diaminophenylmethoxy) cholan-24-acid stearyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane-24-acid stearyl is preferred.

  In addition, as a diamine compound used in order to obtain the repeating unit represented by the said formula (I), it is possible to use together other diamine compounds other than a specific diamine compound in the range by which the effect by this invention is not impaired. is there. Here, the ratio of the specific diamine compound in the entire diamine compound subjected to the reaction is preferably 0.1 to 100 mol%, and particularly preferable ratio is 0.5 to 30 in the TN type and STN type liquid crystal display elements. In a mol%, vertical alignment type liquid crystal display element, it is 10 to 80 mol%, more preferably 10 to 50 mol%.

Examples of other diamine compounds used in combination include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, and 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'-diaminobenzo Enone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2, 2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis ( 4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-bis ( 4-Aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diamy Biphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenylene) Isopropylidene) 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, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy ] -Aromatic diamines such as octafluorobiphenyl;
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylene diamine, tricyclo [6.2.1.0 ^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 2 in the molecule such as phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine and compounds represented by the following formulas (VI) to (VII) A diamine having one primary amino group and a nitrogen atom other than the primary amino group;

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

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

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

(In the formula, R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)
Examples include compounds represented by the following formulas (2) to (6). 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, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2, 2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2 , 2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-amino) Enoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-diamino-2,2′- Dimethylbiphenyl, compounds represented by the above formulas (2) to (6), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, the above formula (VI ) Represented by the following formula (7), among the compounds represented by the above formula (VII), represented by the following formula (8), represented by the above formula (VIII) Of the compounds represented by the following formulas (9) to (18) and the compound represented by the above formula (IX), a compound represented by the following formula (19) is preferable.

<Tetracarboxylic dianhydride>
R ² in the repeating unit represented by the formula (I) and R ⁴ in the repeating unit represented by the formula (II) are tetravalent organic groups obtained by removing four carboxyl groups from tetracarboxylic acid. It is. Specific examples of the tetracarboxylic dianhydride used to obtain the above formula (I) and the above formula (II) include butanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic acid. Dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2 , 3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2, 3,5- Recarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5 , 9b-Hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -7-methyl-5 (tetra Hydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl- 5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1 2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2, 2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, aliphatic and alicyclic tetracarboxylic acids such as compounds represented by the following formulas (X) and (XI) Anhydride;

(Wherein R ¹⁰ and R ¹² represent a divalent organic group having an aromatic ring, R ¹¹ and R ¹³ represent a hydrogen atom or an alkyl group, and a plurality of R ¹¹ and R ¹³ are the same. But it may be different.)
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, represented by the following formulas (20) to (23) An aromatic tetracarboxylic dianhydride such as a compound to be prepared can be mentioned. These may be used alone or in combination of two or more.

  Of these, 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, 5- (2,5-dioxotetrahydrofural) -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-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] Franc-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-naphthalene tetracarboxylic dianhydride, the above formula (X ) Among the compounds represented by the following formulas (24) to (26) and the compound represented by the following formula (XI) among the compounds represented by the formula: It is preferable from the viewpoint that the orientation can be expressed. Preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxy Cyclopentylacetic 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- Examples thereof include dione, pyromellitic dianhydride, and a compound represented by the following formula (24).

<Synthesis of polyamic acid>
The proportion of tetracarboxylic dianhydride and diamine compound used for the synthesis reaction of the polyamic acid containing the repeating unit of the above formula (I) of the present invention is 1 equivalent of the amino group contained in the diamine compound. The ratio in which the acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents is preferable, and the ratio in which 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 the organic solvent used (a) is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight with respect to the total amount (a + b) of the reaction solution. It is preferable that

  In addition, the said organic solvent can use together the alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbons, etc. which are poor solvents of a polyamic acid in the range from which the polyamic acid to produce | generate 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. The reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. The polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Imidized polymer>
The imidized polymer containing the repeating unit of the formula (II) 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. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease.

  On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. 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. 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 reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More 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.

  The preferable imidation ratio in the imidized polymer when constituting the liquid crystal aligning agent of the present invention is 1 to 100%, more preferably 10 to 98%. 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. The imidization rate can be controlled by adjusting the reaction conditions of the dehydration ring-closing reaction.

<End-modified polymer>
The polyamic acid and the imidized polymer constituting the liquid crystal aligning agent of the present invention may be of a terminal modified type having a controlled molecular weight. 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.
Moreover, the liquid crystal aligning agent of this invention is obtained also by the method of copolymerizing a polyimide block and a polyamic acid block as shown by Unexamined-Japanese-Patent No. 2002-204250, for example. In this case, the preferred imidization ratio in the polyimide block is 10 to 100%, more preferably 30 to 98%.

<Logarithmic viscosity of polymer>
The value of logarithmic viscosity (η _ln ) of the polyamic acid and imidized polymer constituting the liquid crystal aligning agent of the present invention is usually 0.05 to 10 dl / g, preferably 0.1 to 5 dl / g.
The value of the logarithmic viscosity (η _ln ) in the present invention is determined by measuring the viscosity at 30 ° C. for a solution having a concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent. ).

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is preferably constituted by constituting the polyamic acid and the imidized polymer dissolved in an organic solvent.
The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.
As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together.

  The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is When the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film cannot be obtained. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics.

  The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound or an epoxy group-containing compound from the viewpoint of improving the adhesion to the substrate surface. Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl- , 4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N -Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, etc. can be mentioned.

  Examples of 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-dibromoneopentylglycol 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 , And the like as preferred 4'-diaminodiphenylmethane. The blending ratio of these functional silane-containing compounds and epoxy group-containing compounds is preferably 60 parts by weight or less, more preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the polymer.

<Liquid crystal display element>
The liquid crystal display element of the present invention can be produced, for example, by the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, a printing method, 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. Can be used. 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. As long as it has sufficient reflectivity, it is not limited to these. 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. 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. It can also be a membrane. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

  (2) As shown in Japanese Patent Application Laid-Open No. 2002-327058, a structure is formed on a substrate using a photosensitive resin, and a vertical liquid crystal alignment film is formed thereon. To do.

(3) Two substrates on which the vertical liquid crystal alignment film is formed as described above are manufactured, the two substrates are arranged to face each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are sealed. A liquid crystal cell is formed by laminating using an agent, injecting and filling liquid crystal into the cell gap defined by the substrate surface and the sealing agent, and sealing the injection hole. 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 printability and vertical alignment in the examples and comparative examples were evaluated by the following methods.

[Printability test of liquid crystal alignment agent]
With a transparent electrode in which the liquid crystal aligning agent of the present invention is formed in stripes at intervals of 100 μm using a liquid crystal aligning film printer (Nissha Printing Co., Ltd.) and having a film thickness of 200 nm and a width of 20 μm. After coating on the transparent electrode surface of the glass substrate and forming a liquid crystal alignment film by firing, the peripheral part and the center part of this liquid crystal alignment film are observed with a microscope with a magnification of 20 times. The case where there was coating unevenness was determined as “bad”.

[Vertical alignment]
The liquid crystal display element at the time of voltage OFF and alternating current 12V (peak-peak) was observed under crossed Nicols, the presence or absence of an abnormal domain was observed with a polarizing microscope, and the case where there was no abnormal domain was determined as “good”.

Synthesis example 1
1.0 mol of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 0.8 mol of p-phenylenediamine as diamine compound, 1-cholestanioxymethyl-2,4-diaminobenzene 0.2 mol was dissolved in 4,500 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, it was washed with methyl alcohol and dried at 40 ° C. under reduced pressure for 15 hours to obtain 400 g of polyamic acid having a logarithmic viscosity of 0.50 dl / g.
30 g of the resulting polyamic acid was dissolved in 570 g of N-methyl-2-pyrrolidone, 5.7 g of pyridine and 7.4 g of acetic anhydride were added, and dehydration was carried out at 110 ° C. for 4 hours, followed by precipitation, washing, The pressure was reduced to obtain 19.0 g of polyimide having an imidization ratio of 52% and a logarithmic viscosity of 0.41 dl / g (hereinafter referred to as “polyimide (PI-1)”).

Synthesis example 2
In Synthesis Example 1, the same procedure as in Synthesis Example 1 except that 1-cholestanioxy-1,1-difluoromethyl-2,4-diaminobenzene was used instead of 1-cholestanioxymethyl-2,4-diaminobenzene. Thus, 390 g of polyamic acid having a logarithmic viscosity of 0.37 dl / g was obtained. Except for using 30 g of the obtained polyamic acid, imidization was carried out in the same manner as in Synthesis Example 1, and a polyimide having an imidization ratio of 49% and a logarithmic viscosity of 0.32 dl / g (this is referred to as “polyimide (PI-2)”). ) 18.9 g was obtained.

Synthesis example 3
In Synthesis Example 1, a logarithmic viscosity of 0.40 dl / g was obtained in the same manner as in Synthesis Example 1, except that cholestanyl 3,5-diaminobenzoate was used instead of 1-cholestanioxymethyl-2,4-diaminobenzene. 390 g of polyamic acid was obtained. Except for using 30 g of the obtained polyamic acid, imidization was performed in the same manner as in Synthesis Example 1, and a polyimide having an imidization ratio of 55% and a logarithmic viscosity of 0.32 dl / g (this is referred to as “polyimide (PI-3)”). ) 18.9 g was obtained.

Synthesis example 4
In Synthesis Example 1, Synthesis Example 1 except that 0.2 mol of 1-octadecyloxy-2,4-diaminobenzene was used instead of 0.2 mol of 1-cholestanioxymethyl-2,4-diaminobenzene. In the same manner as above, 372 g of polyamic acid having a logarithmic viscosity of 0.17 dl / g was obtained. Except for using 30 g of the obtained polyamic acid, imidization was performed in the same manner as in Synthesis Example 1, and a polyimide having an imidization ratio of 51% and a logarithmic viscosity of 0.35 dl / g (this is referred to as “polyimide (PI-4)”). ) 18.9 g was obtained.

Example 1
(Printability test)
The partially imidized polymer (PI-1) obtained in Synthesis Example 1 was dissolved in a mixed solvent of N-methyl-2-pyrrolidone / γ-butyrolactone / ethylene glycol monobutyl ether (weight ratio 70/10/20). A solution having a solid content concentration of 5% by weight was prepared, and after sufficient stirring, the solution was filtered using a filter having a pore size of 1 μm to prepare the liquid crystal aligning agent of the present invention. The liquid crystal aligning agent is applied onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate using a liquid crystal aligning film printer (Nissha Printing Co., Ltd.), on a hot plate, Temporary drying was performed at 80 ° C. for 1 minute, followed by drying at 200 ° C. for 1 hour in a clean oven, thereby forming a liquid crystal alignment film having a dry film thickness of 500 mm. No coating unevenness was observed in this liquid crystal alignment film. Therefore, the printability of the liquid crystal aligning agent prepared in Example 1 was determined as “good”.

(Vertical orientation test)
The partially imidized polymer (PI-1) obtained in Synthesis Example 1 was dissolved in a mixed solvent of N-methyl-2-pyrrolidone / γ-butyrolactone / ethylene glycol monobutyl ether (weight ratio 70/10/20). After a solid solution having a solid concentration of 3.5% by weight and sufficient stirring, the solution was filtered using a filter having a pore size of 1 μm, and then a spinner was placed on the transparent conductive film made of an ITO film provided on one surface of the glass substrate. A transparent electrode substrate having a liquid crystal alignment film having a dry film thickness of 500 mm by performing temporary drying at 80 ° C. for 1 minute on a hot plate and then drying at 200 ° C. for 1 hour in a clean oven. Created. Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer edges of the pair of transparent electrodes / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, the liquid crystal alignment film The adhesive was cured by overlapping and pressing so that the surfaces were opposed. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. The liquid crystal display element was manufactured and the vertical alignment property of the obtained liquid crystal display element was evaluated. As a result, no abnormal domain was generated, and it was determined that the liquid crystal display element was “good”.

Example 2
In Example 1, the polymer (PI-2) obtained in Synthesis Example 2 was used in place of the polymer (PI-1), and the same procedure as in Example 1 was performed to adjust the liquid crystal aligning agent. In the same manner as above, printability and vertical alignment were evaluated. The results are shown in Table 1.

Comparative Examples 1-2
In Example 1, instead of the polymer (PI-1), the polymers (PI-3) and (PI-4) obtained in Synthesis Examples 3 and 4 were used respectively in the same manner as in Example 1. The liquid crystal aligning agent was adjusted, and the printability and vertical alignment were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Claims (3)

Formula (I)

And the following formula (II)

Here, R ¹ and R ³ are divalent organic groups obtained by removing two amino groups from a diamine independently of each other, and R ² and R ⁴ are independently of each other four carboxyl groups from a tetracarboxylic acid. Is a tetravalent organic group, and m and n are positive integers, provided that at least one of R ¹ and R ³ is represented by the following formula (III):

Here, C is a monovalent organic group having a steroid skeleton, A is may have a halogen atom as a substituent is an alkylene group having 1 to 4 carbon atoms, B is a d ether bond group Is an organic group represented by
Characterized in that it contains a polymer containing at least one repeating unit selected from the group consisting of repeating units represented by each of the above (limited to polymers having an organic group represented by formula (III)). Liquid crystal aligning agent. The polymer is a polymer obtained by reacting a tetracarboxylic dianhydride and a diamine compound or a polymer obtained by dehydrating ring-closing imidization of the polymer; and
The liquid crystal aligning agent of Claim 1 which contains 0.1-100 mol% of diamine compounds in which the said diamine compound has an organic group represented by the said Formula (III) with respect to the whole diamine compound. The liquid crystal display element characterized by including the liquid crystal alignment film formed from the liquid crystal aligning agent of claim 1 or 2 wherein.