WO2008105564A1 - Liquid crystal aligning agent and liquid crystal display - Google Patents

Abstract

Disclosed is a liquid crystal aligning agent containing a polyamic acid obtained by using an aliphatic tetracarboxylic acid dianhydride represented by the formula (1) below and p-phenylenediamine, and an imidized polymer of such a polyamic acid. (In the formula, R1-R6 independently represent a hydrogen atom or an alkyl group having 1-20 carbon atoms; and m and n independently represent an integer of 0-3.) The liquid crystal aligning agent has good coating property and high initial voltage holding ratio, and enables to obtain a liquid crystal alignment film which is small in decrease of voltage holding ratio even when light or thermal stress is applied to a liquid crystal display or the liquid crystal display is operated for a long time.

Description

 Liquid crystal aligning agent and liquid crystal display element

 The present invention relates to a novel liquid crystal aligning agent and a liquid crystal display element. More specifically, it has a structure derived from a specific aliphatic tetracarboxylic dianhydride, has excellent coating properties when forming a liquid crystal alignment film, exhibits a high voltage holding ratio, and is displayed on the liquid crystal panel by light or heat.

A novel liquid crystal aligning agent that can suppress a decrease in the voltage holding ratio when a resist is applied for a long time or a liquid crystal panel is driven for a long time, and a document formed from the liquid crystal aligning agent.

The present invention relates to a liquid crystal alignment film comprising the liquid crystal alignment film.

Background art

 Since LCD calculators were mass-produced for the first time, liquid crystal display elements represented by liquid crystal displays from the viewpoint of space saving and low power consumption. Watches, portable games, word processors, notebook computers, car navigation systems, camcorders, etc. , PDAs, digital cameras, mobile phones, various monitors, LCD TVs, etc. are being applied in various fields, and active development is continuing. As the liquid crystal display element, nematic liquid crystal having positive dielectric anisotropy is used, and the major axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. Twisted Nematic (LCD) elements and STN (Super Twisted Nematic) LCD elements, which have higher contrast than TN liquid crystal display elements, have been widely used. In recent years, in order to further improve the display quality of liquid crystal displays, the VA (vertical alignment) type liquid crystal display element, IPS (In Plane Switching) type liquid crystal display element, which has a small viewing angle dependency, Optically compensated bend (OCB) type liquid crystal display elements have been developed that have a small viewing angle dependency and excellent high-speed response of video screens.

In the liquid crystal display element, a member for controlling the alignment of the liquid crystal is a liquid crystal alignment film. liquid crystal The alignment film is obtained by applying a liquid crystal alignment agent containing a polyamic acid or an imidized polymer obtained by imidizing the polyamic acid by a mouthful method, a spinner method, a flexographic printing method, an inkjet method, or the like. It is formed by applying to the substrate and then heating and drying the coated surface. Here, uneven coating of the liquid crystal alignment film directly leads to poor alignment of the liquid crystal, and causes a significant deterioration in the display quality of the liquid crystal panel. In order to improve the electrical characteristics such as voltage holding ratio of the polyimide-containing liquid crystal aligning agents that have been used in the past, studies have been made to increase the imidization ratio of polyimide. However, the high imidization ratio and the applicability of the liquid crystal aligning agent are poor. There is a need for the development of a liquid crystal aligning agent that has a lade-off relationship and has both excellent electrical properties and coating properties. To date, examples of methods for improving the voltage holding ratio include adding a polyfunctional epoxy compound to a polyamic acid (Japanese Patent Laid-Open No. 10-166485), and using a raw material for polyamic acid and imidized polymer. Examples of attempts to improve the structure of some tetracarboxylic dianhydride diamin (Patent No. 3 5 7 2 6 90 and JP 2 0 0 1-2 2 8 4 8 1), acrylic polymer in polyamic acid (Patent No. 3 2 0 6 1 6 9) has been reported. However, the improvement effect of the initial voltage holding ratio and the reliability (the voltage holding ratio does not change even if a heat stress is applied to the liquid crystal panel or the liquid crystal panel is driven for a long time) according to these reports is sufficient. In addition, it was not considered from the viewpoint of improving the coating property at the time of forming the liquid crystal alignment film. In recent years, as liquid crystal panels have been applied to liquid crystal TVs and high-quality monitors, the liquid crystal alignment film has a high voltage holding ratio, reliability of the voltage holding ratio, and liquid crystal alignment to achieve high-quality display performance. There is an urgent need to further improve the coating properties during film formation. Disclosure of the invention

The present invention has been made based on the circumstances as described above. Therefore, the object of the present invention is to exhibit good coating properties and high initial voltage holding ratio, and to apply light and thermal stress to a liquid crystal display element. Applying or driving a liquid crystal display element for a long time displays a beautiful image over a long period of time by a liquid crystal aligning agent that gives a liquid crystal aligning film with a small decrease in voltage holding ratio and a liquid crystal aligning film formed from the liquid crystal aligning agent LCD device capable of About.

 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. One or more aliphatic tetracarboxylic dianhydrides represented by the following formula (1) and, if necessary, other tetracarboxylic dianhydrides and It contains at least one polymer selected from polyamic acid obtained by polyaddition reaction of p-phenylenediamine and other diamines if necessary, and imidized polymer obtained by imidizing the polyamic acid. This is achieved by a liquid crystal aligning agent.

(In the formula,! ^ ¹ to! ^ ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and m and n each independently represents an integer of 0 to 3. In addition, according to the present invention, the above object of the present invention is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the above liquid crystal aligning agent. The invention's effect

According to the liquid crystal aligning agent of the present invention, good coating properties and high initial voltage holding ratio are exhibited, and voltage holding is possible even when light or heat stress is applied to the liquid crystal display element or the liquid crystal panel is driven for a long time. The liquid crystal aligning agent which gives the liquid crystal aligning film with a small fall of a rate is obtained. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

 [Polyamic acid and imidized polymer]

 The polyamic acid used in the present invention is composed of one or more aliphatic tetracarboxylic dianhydrides represented by the above formula (1) and, if necessary, other tetracarboxylic dianhydrides and P-phenylene diene. It can be obtained by polyaddition reaction of an amine and, if necessary, other diamines. The imidized polymer used in the present invention can be obtained by dehydrating and ring-closing the polyamic acid.

 The liquid crystal aligning agent of the present invention includes a tetracarboxylic dianhydride represented by the above formula (1) as a tetracarboxylic dianhydride for synthesizing a polyamic acid and a Z or imidized polymer contained therein. By using one or more of these materials and other tetracarboxylic dianhydrides as required, excellent coating properties, high initial voltage holding ratio, and high reliability of the liquid crystal display device are exhibited. In the present invention, a polyamic acid synthesized using a tetracarboxylic dianhydride represented by the above formula (1) is a tetracarboxylic dianhydride that has been conventionally studied in a baking process after application of a liquid crystal director. Compared to polyamic acids synthesized using products, thermal imidization is more likely to proceed, and a liquid crystal alignment film having a high imidization ratio can be obtained. Therefore, a high initial voltage holding ratio and liquid crystal display elements are subjected to light and thermal stress. It is possible to provide a liquid crystal alignment film in which the decrease in voltage holding ratio is small even when applied or when the liquid crystal panel is driven for a long time.

In the present invention, the use ratio of the tetracarboxylic dianhydride represented by the above formula (1) is preferably 5 to 100 mol%, more preferably 2 based on the total tetracarboxylic dianhydride. It is 5 to 100 mol%, particularly preferably 50 to 100 mol%. In the above formula (1), scales ¹ to! ^ ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Particularly preferred is a hydrogen atom or a methyl group. m and n are each independently an integer of 0 to 3, preferably 0 or 1, and in particular, m = n = 0, a structure represented by the following formula (2) or m = 1, n A structure represented by the following formula (3) represented by = 0 is preferable.

The tetracarboxylic dianhydrides represented by the above formula (1) can be used alone or in combination of two or more.

A tetracarboxylic dianhydride different from the tetracarboxylic dianhydride represented by the above formula (1), and optionally together with the tetracarboxylic dianhydride represented by the above formula (1) Other tetracarboxylic dianhydrides that can be used include, for example, butane tetracarboxylic dianhydride, 1, 2, 3, 4-cyclobutane tetracarboxylic dianhydride, 1, 2-dimethyl-1, 2, 3 , 4-Cyclobutane tetra force sulfonic acid dianhydride, 1,3-dimethyl-1, 2, 3, 4-cyclobutane tetra force sulfonic acid dianhydride, 1, 3-dichloro-1, 2, 3, 4-cyclobutane tetra force Ruponic acid 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-tricarboxycyclopentyl acetic acid dianhydride, 3, 5, 6-tricarboxynorbornane 1 2 monoacetate 2 Anhydride, 2, 3, 4, 5-tetrahydrofurantetracarboxylic dianhydride 1, 3, 3, 3 a, 4, 5, 9 b—Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) 1-naphtho [1,2-c] —furan 1,3-dione, 1 , 3, 3 a, 4, 5, 9 b—Hexahydro-5 _methyl _ 5— (tetrahydro-2,5-dioxo-3-furanyl) 1-naphtho [1,2-c] —furan 1,3-dione 1, 3, 3 a, 4, 5, 9 b—Hexahydro-5-ethyl-5- (tetrahydro-1,5-dioxo-3-furanyl) 1 naphtho [1, 2— c] —furan 1,3-Dione 1, 3,3 a, 4, 5, 9 b-Hexahydro 7-methyl-5- (tetrahydro-1,5-dioxo-3-furanyl) One naphtho [1, 2-c] 1-furan 1,3-dione 1, 3, 3 a, 4, 5, 9 b—Hexahydro 1-ethyl 5- (tetrahydro-2,5-dioxo 3-furanyl) 1 naphtho [1, 2— c] —Fran, 1, 3-dione, 1, 3, 3 a, 4, 5, 9 b—Hexahydro 1-Methyl 1 5— (Tetrahydro-2, 5-Dioxo 3-furanyl) One naphtho [1, 2-c] —Furan 1,3-dione, 1 , 3, 3 a, 4, 5, 9 b—Hexahydro 8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) 1-naphtho [1, 2-c] —furan 1,3-dione, 1 , 3, 3 a, 4, 5, 9b—Hexahydro _5,8-dimethyl-5 (tetrahydro-1,5-dioxo-3-furanyl) 1-naphtho [1,2-c] —furan-1,3-dione , 5- (2,5-Dioxotetrahydrofuranyl) 1-methyl-3-cyclohexene 1,2-dicarbolic anhydride, bicyclo [2.2.2] —Oct 7-en-2, 3, 5, 6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane 1, 2, 4-dione 6-spiro 3, one (tetrahydrofuran 1 ', 5'-dione), 3 , 5, 6 —Tri-Lupoxyl 2--Strong Lupoxynorpornan-2: 3, 5: 6-dianhydride, bicyclo [3.3.0] Octane 1,2,4,6,8-tetracarboxylic dianhydride, Aliphatic and alicyclic teracarboxylic dianhydrides such as compounds represented by the following formulas (4) and (5) respectively;

(Wherein R ¹⁵ and R ¹⁷ each represent a divalent organic group having an aromatic ring, R ¹⁶ and R ¹⁸ each represent a hydrogen atom or an alkyl group, and a plurality of R ¹⁶ and R ¹⁷ are present. ¹⁸ may be the same or different.) Pyromellitic dianhydride, 3, 3 ', 4, 4' Monobenzophenone tetracarboxylic dianhydride, 2, 3, 3 ', 4' Benzophenone tetracarboxylic dianhydride, 2, 2,, 3, 3, —Benzophenone tetracarboxylic dianhydride, 3, 3 ', 4, 4'-biphenylsulfone tetracarboxylic dianhydride 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2, 3, 6, 7-naphthalene tetracarboxylic dianhydride, 3, 3 ', 4, 4, biphenyl Tertetracarboxylic dianhydride, 3, 3 ', 4, 4' —Dimethyldiphenylsilane tetracarboxylic dianhydride, 3, 3 ', 4, 4 , -Tetraphenylsilane tetracarboxylic dianhydride, 1, 2, 3, 4 monofuran tetracarboxylic dianhydride, 4, 4 'monobis (3,4-dicarboxphenoxy) diphenyl sulfide dianhydride 4, 4'-bis (3, 4-dicarboxyphenoxy) diphenyl sulfone dianhydride, 4, 4, mono-bis (3,4-di-functional oxyphenoxy) diphenyl propane dianhydride, 3 , 3 ', 4, 4, super —Fluoroisopropylidenedifuric acid dianhydride, 3, 3 ', 4, 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxidone anhydride, p-phenol Ren-bis (triphenylphthalic acid) dianhydride, m-phenylene bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) _ 4, 4, diphenyl ether dianhydride, bis (Triphenylphthalic acid) —4, 4, 1-diphenylmethane dianhydride, ethylene glycol monobis (anhydrotrimellitate), propylene glycol monobis (anhydrotrimellitate), 1,4-butanediol monobis (anhydro) Trimetrate), 1,6-hexanediol bis (anhydrotrimellite), 1,8-octanediol bis (anhydride) Rotrimelitate), 2, 2_bis (4-hydroxyphenyl) propane monobis (anhydro trimellitate), aromatic tetracarboxylic compounds such as compounds represented by the following formulas (6) to (8) Mention may be made of acid dianhydrides.

Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl '1, 2,3,4-cyclobutanetetracarboxylic dianhydride 1, 2, 3, 4-cyclopentanetetra- force sulfonic acid dianhydride, 1, 2, 4, 5-cyclohexane tetracarboxylic dianhydride, 2, 3, 5-tri-force l-poxycyclopentyl acetic acid Dianhydride, 5_ (2,5-dioxotetrahydrofuranyl) 1-methyl-1-cyclohexene 1,2-dicarboxylic anhydride, 1, 3, 3 a, 4, 5, 9 b- Oxahydro-5- (tetrahydro-2,5-dioxone 3-furanyl) one naphtho [1, 2- c] furan 1,3-dione, 1, 3, 3 a, 4, 5, 9 b-hexahydro- 8-Methyl-5- (Tetrahydro-1,5-Dioxo-3-furanyl) One-naphtho [1,2-c] Furan-1,3-dione 1, 3, 3 a, 4, 5, 9 b—Hexahydro-1,5,8-dimethyl-1,5- (tetrahydro-1,2,5-dioxone 3-furanyl) One naphtho [1, 2 -c] furan 1,3-dione, bicyclo [2. 2. 2] —oct 7_2, 2, 5, 5, 6-tetracarboxylic dianhydride, 3-oxabicyclo [3. 2. 1] Octane 2,4-dione 1 6-spiro 1,3 (tetrahydrofuran 1 2 ', 5'-dione), 3, 5, 6-tri-force loxy- 2-force l-poxy norporan 2: 3, 5: 6-dianhydride, bicyclo [3. 3. 0] octane 1, 2, 4, 6 8—tetra-force sulfonic acid dianhydride, pyromellitic dianhydride, 3, 3 ', 4, 4' Benzophenone tetra force sulfonic acid dianhydride, 2, 3, 3,, 4, monobenzophenone tetracarboxylic dianhydride, 2, 2 ', 3, 3, monobenzophenone tetra force rubonic acid dianhydride 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, a compound represented by the above formula (4) Below Among the compounds represented by the formulas (9) to (11) and the compound represented by the above formula (5), the compound represented by the following formula (12) exhibits good liquid crystal orientation. It is preferable from the viewpoint that can be made. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1: 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 2, 4 , 5-cyclohexanetetracarboxylic dianhydride, 2, 3, 5-tricarboxycyclopentylacetic acid dianhydride, 1, 3, 3 a, 4, 5, 9b-hexahydrone 5- (tetrahydro-1,2, 1-naphtho [1,2-c] furan 1,3-dione, 1,3,3a, 4,5,9 b-hexahydro-1-8-methyl-5- (tetrahydro-2 , 5-Dioxo-1-3-furanyl) 1-naphtho [1, 2-c] Furan 1,3-Dione, 3-Oxapicyclo [3.2.1] Octane-2, 4-Dione 6-Spiro 1 , One (tetrahydrofuran one 2 ', 5'-dione), 3, 5, 6-tri-roxyloxy-2-carboxylnornan-2: 3, 5 : 6-dianhydride, bicyclo [3. 3. 0] octane 1, 2, 4, 6, 8 —tetracarboxylic dianhydride, pyromellitic dianhydride, 3, 3 ', 4, 4, 1 benzo Mention may be made of phenonetetracarboxylic dianhydride and compounds represented by the following formula (9).

Other tetracarboxylic dianhydrides different from the tetracarboxylic dianhydride represented by the above formula (1) used as necessary are used singly or in combination of two or more.

[Jamin]

The liquid crystal aligning agent of the present invention comprises P-phenylenediamine as an essential component as a diamine. High initial voltage holding ratio is expressed by using other diamine if necessary. The proportion of P-phenylenediamine used in the present invention is preferably 5 to 100 mol%, more preferably 10 to 100 mol%, and particularly preferably 25 to 100 mol%, based on the total diamine.

 Other diamines differ in preferred compounds depending on the method in which the liquid crystal aligning agent of the present invention is used. When the liquid crystal aligning agent of the present invention is used in the TN method, STN method, OCB method or VA method, as the diamine used for the synthesis of the main component polymer, in addition to p-phenylenediamine, the following formula ( It is preferable to use together a diamine having a pretilt angle expression site represented by 13) or the following formula (14).

(Wherein R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, R ⁹ is a linear or branched alkyl group having 1 to 20 carbon atoms, and R ^1Q and R ¹¹ are Each independently is a divalent organic group)

(Wherein, a is 0 or 1, R ¹² is an ether bond (10), carbonyl group (One CO—), strong sulfonyloxy group (—COO—), oxycarbonyl group (—OC 2 O—), amide bond (one NHCO—, one CONH—), thioether bond (one S one) and methylene group R ¹³ is a divalent organic group different from R ¹² , R ¹⁴ is a group having a steroid skeleton, a group having a fluorine atom, and 1 to 30 carbon atoms. And a group selected from a group having a linear or branched alkyl group. ) Diamines having these pretilt angle sites can be used alone or in combination of two or more.

 Specific examples of diamines represented by the above formula (13) include compounds represented by the following formulas (15) and (16).

Specific examples of diamines represented by the above formula (14) include compounds represented by the following formulas (17)).

(6 T)

80ll7S0 / 800Zdf / X3d

When the liquid crystal aligning agent of the present invention is used for the TN, STN, or OCB method among the TN method, STN method, CB method, and VA method, each of the above formulas (13) and (14) By using a diamine having at least one pretilt angle expression site selected from the diamines represented, the pretilt angle of the liquid crystal of 1 to 30 ° can be stably expressed. In this case, the amount of diamine having a pretilt angle expression site is preferably 0.5 to 30 mol%, more preferably 0.7 to 20 mol%, particularly preferably 1 to 15 mol, based on the total diamine. %. In addition, as a diamine having a pretilt angle expression site, the above formula (15) to

It is particularly preferred to use at least one diamine represented by each of (21).

When the liquid crystal aligning agent of the present invention is used for the VA method among the TN method, STN method, OCB method, and VA method, the liquid crystal aligning agent exhibits an excellent vertical alignment property of the liquid crystal. It is preferable to use the diamine represented by the above formula (14) among the diams having S, and the use amount thereof is preferably 8 to 60 mol%, more preferably 9 to 50 mol%, based on the total diamine. Particularly preferred is 10 to 25 mol%. Further, as the diamine having a pretilt angle-expressing site, it is preferable to use diamines represented by the above formulas (17) to (21), and in particular, the diamine represented by the above formula (17) or (18). Is preferably used. On the other hand, when the liquid crystal aligning agent of the present invention is used for the IPS method or the FFS method, the above-described diamine having the pretilt angle-expressing portion may be used. Use other diamines as other diamines Thus, it is preferable to synthesize the main component polymer.

 Examples of the diamine other than P-phenylenediamine used for the synthesis of the main component polymer of the liquid crystal aligning agent of the present invention and the diamine having the pretilt angle expression site include the following diamines. .

m-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenyls / Hong, 2,2'-Dimethyl-4,4'-Diaminobiphenyl, 4,4'-Diaminobenzanilide, 4,4'-Diaminodiphenylether, 1,5-Diaminonaphthalene, 3, 3 'Dimethyl-4,4'-diaminobiphenyl, 5-amino-1- 1- (4'-aminophenyl) 1,1,3,3-trimethylindane, 6-amino-1- 1- (4, aminophenyl) _1, 3, 3 — Trimethylindane, 3, 4, monodiaminodiphenyl ether, 3, 3, diaminobenzophenone, 3, 4, —diaminobenzophenone, 4, 4, —diaminobenzophenone, 2, 2-bis [4— (4 Monoaminophenyl) phenyl] Hexafluoropropane, 2, 2 bis (4-aminophenyl) Hexafluorop Mouth bread, 2, 2-bis [4- (4-aminophenoxy) phenyl] sulfone, 2, 2-bis (4— (4-aminophenoxy) [Phenyl] propane, 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 monobis (2-chloroaniline), 2, 2', 5 , 5, 1-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4, -diamino-5,5'-dimethoxybiphenyl, 3, 3, 1-dimethoxy-1,4,4, 1-diaminobiphenyl 1, 4, 4, 1 (ρ-phenylene isopropylidene) bisaniline, 4, 4, 1 (m-phenylene isopropylidene) bisaniline, 2, 2, 1 bis [4 1 (4-amino-2-triflue) Fluoromethyl) hexafluoropropane, 4, 4, diamino-1, 2, 2 '—bis (trifluoromethyl) biphenyl, 4, 4, Amino-2,2'-dimethylbiphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] monofluorofluorobiphenyl, 1,3-bis (4aminophenoxy) Aromatic diamines such as 1,2,2-dimethylpropane, 4,4,1bis (41-aminophenoxy) biphenyl;

2,3-Diaminopyridine, 2,6-Diaminopyridine, 3,4-Diaminopyridine, 2,4-Diaminopyrimidine, 5,6-Diamino-2,3-Dicyanopyrazine, 5,6-Diaminopyridine 2,4-Dihydroxy Pyrimidine, 2,4-Diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminobu pill) Piperazine, 2,4-Diamino _ 6-Isopropoxy 1, 3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenol 1,3,5-triazine, 2,4-diamino-6-methyl-s —Triazine, 2,4-Diamino-1, 3,5—Triazine, 4, 6 —Diamino-2-vinyl-1-s-triazine, 2,4-Diamino-1-5-phenylthiol, 2,6-Diaminopurine, 5, 6—Diamino 1,1,3 Dimethylura 3,5-diamino-1,2,4_triazole, 6,9-diamino-2-hydroxyhexyl lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diamino Like piperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, and compounds represented by the following formulas (22) and (23), two primary amino groups and A diamine having a nitrogen atom other than the primary amino group;

Is pyridine, pyrimidine, triazine, piperidine and pipera X represents a divalent organic group having a ring structure containing a nitrogen atom selected from gin, and X represents a divalent organic group. )

(Wherein R ² ° represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine)

3-bis (aminomethyl) cyclohexane, 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine, hexamethylenediamine, octamethylenediamine, nonamethylenediamine, 4 Holondiamin, Tetrahydrodicyclopentanegenylenediamine, Hexahydride 1,7-Methanoin danylene diethylenediamine, Tricyclo [6. 2. 1. 0 ² ' ⁷ ] —Undecylenedimethyl And aliphatic and cycloaliphatic diamines such as 4,4'-methylenebis (cyclohexylamine);

A diaminoorganosiloxane represented by the following formula (24):

(In the formula, each R represents a hydrocarbon group having 1 to 12 carbon atoms, R ^{2 1} may be the same or different, p is an integer of 1 to 3, and Q is an integer of 1 to 20, respectively. ). These p-phenylenediamine and other diamines other than the diamine having the pretilt angle expression site are used alone or in combination of two or more.

Of these, 4,4, -diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 9, 9-bis (4-aminophenyl) fluorene, 2, 2-bis [4- (4-aminophenoxy) phenyl] propan, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluorop 2,2-bis (4-aminophenol) hexafluoropropane, 1,4—bis (4-aminophenoxy) benzene, 4, 4, monobis (4 monoaminophenoxy) biphenyl, 4, 4 '-Daminoamino 2, 2' Bis (trifluoromethyl) biphenyl, 4, 4, diamino-2, 2, —dimethylbiphenyl, 2, 6-diaminopyridine, 3, 4-diaminopyridine, 2, 4— Gamino Limidine, 3,6-diaminoacridine, a compound represented by the following formula (25) among the compounds represented by the above formula (22), and a compound represented by the following formula (2 6) among the compounds represented by the above formula (23) 1, 3-bis (aminomethyl) cyclohexane, 1,4-cyclohexanediamine, 4,4, -methylenebis (cyclohexylamine), a compound represented by the above formula (24) Of these, 3,3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine) represented by the following formula (27) is preferable.

(26)

More particularly preferred are 4,4, -diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylether, 2,7-diaminofluorene, 3 , 3'— (Tetramethyldisiloxan-1,3-diyl) bis (propylamine), 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis (aminomethyl) cyclohexane 2,2,2-bis (4-aminophenyl) hexafluoropropane and 4,4,1-diamino 2,2,2'-bis (trifluoromethyl) biphenyl.

<Synthesis of polyamic acid>

Tetracarboxylic dianhydride and diester used in the polyamic acid synthesis reaction of the present invention The proportion of amine used is preferably such that the amount of acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents, more preferably 0.3 to 1 equivalent of amino groups contained in diamine. It is the ratio which becomes -1.2 equivalent.

 The polyamic acid synthesis reaction is preferably carried out in an organic solvent at a temperature of 120 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 Examples thereof include aprotic polar solvents such as propylamine, tetramethylurea, and hexamethylphosphoric triamide; and phenolic solvents such as m-cresol, xylenol, phenol, and halogenated phenol. In addition, the amount of organic solvent used (a) is 1 to 30% by weight based on the total amount of reaction solution (a + b) when the total amount of tetraforce rubonic acid dianhydride and diamine (b) is used. Such an amount is preferred.

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 resulting polyamic acid does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, ethylene glycol monomethyl ether. , Ethyl lactate, Peptyl lactate, Acetone, Methyl ethyl ketone, Methyl isobutyl ketone, Cyclohexanone, Methyl acetate, Ethyl acetate, Butyl acetate, Methyl methoxypropionate, Ethyl ethoxypropionate, Propylene carbonate, Jetyl oxalate, Jetyl malonate, Jetyl ether, Ethylene glycol methyl ether, Ethylene glycol ether ether, Ethylene glycol-n-propyl ether, Chirenguriko one Lou i- Puropirue one ether, ethylene glycol monobutyl ether (Buchiruse port cellosolve), Echire glycol dimethyl E one ether, ethylene da recall E chill ether § cetearyl Ichito, diethylene glycol dimethyl ether, diethylene glycol one Rujechiruete , 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-di Examples include chlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These poor solvents can be used alone or in combination of two or more.

 As described above, a reaction solution obtained by dissolving polyamic acid is obtained. Then, after pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, the precipitate is dried under reduced pressure to obtain a polyamic acid. In addition, 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 used in the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing the polyamic acid. The imidized polymer referred to here includes a partially imidized polymer obtained by partially imidizing the polyamic acid and a polymer obtained by immobilizing 100%. “Combined”.

 The preferred imidization ratio in the imidized polymer used in the liquid crystal aligning agent of the present invention is 10 to 100%, more preferably 20 to 99%, and particularly preferably 40 to 98%. Here, the “imidation ratio” is the percentage of the number of imide rings to the total of the number of amic acid structures and the number of imide rings in the polymer. At this time, a partial force of the imide ring may be an S isoimide ring.

As a method of synthesizing an imidized polymer, (I) a method of synthesizing the polyamic acid by heating and dehydrating and ring-closing, and (II) a method of dissolving the polyamic acid in an organic solvent, and adding a dehydrating agent to the solution. And a method of synthesizing by dehydration and ring closure by adding a dehydration and ring closure catalyst and heating as necessary. A polymer having a desired imidization rate can be obtained by controlling it.

 The reaction temperature in the method of heating the polyamic acid (I) is preferably 50 to 300 ° C., more preferably 100 to 25 50. C. If the reaction temperature is less than 50, the dehydration ring-closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 300 ° 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, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride may be used as the dehydrating agent. it can. The amount of the dehydrating agent used is preferably 0.1 to 20 mol per 1 mol of the polyamic acid repeating unit. As the dehydration ring closure catalyst, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, the dehydrating agent and the dehydration ring closure catalyst are not limited to these examples. The amount of the dehydration ring closure catalyst used is preferably from 0.01 to 10 moles per mole of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring-closing reaction include the same organic solvents as exemplified for use in the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C., more preferably 60 to 150 ° C. 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.

<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 properties 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, examples of the acid monoanhydride include dicarboxylic acid monoanhydride S, such as maleic anhydride, phthalic anhydride, Itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride, etc. . Examples of monoamine compounds include aniline, cyclohexylamine, p-ethylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n -Undecylamine, n-dodecylylamine, n-tridecylamine, n-tetradecylamine, n-pendecylamine, n-hexadecylamine, n-heptdecylamine, n-octyldecylamine, n-eicosylamine, etc. Can be mentioned. In addition, examples of monoisocyanate compounds include phenyl isocyanate and naphthyl isocyanate. Logarithmic viscosity of the polymer>

The value of the logarithmic viscosity (7? _Ln ) of the polyamic acid and imidized polymer obtained as described above is preferably 0.05 to L0d1 / g, more preferably 0.05 to 5 d 1 / g.

The value of the logarithmic viscosity (77 _ln ) in the present invention was determined by measuring the viscosity at 30 ° C. for a solution having a concentration of 0.5 gZ l 00 ml using N-methyl-2-pyrrolidone as a solvent. It is obtained by the following formula (a).

1 n (solution flow time / solvent flow time)

 7? M II ... (a)

 (Weight concentration of polymer) <Liquid crystal aligning agent>

The liquid crystal aligning agent of the present invention is constituted by dissolving a polyamic acid and an imidized polymer in an organic solvent. The liquid crystal aligning agent of the present invention is an aliphatic tetramer represented by the above formula (1) of the present invention in order to improve the seizure resistance and the coating properties during the formation of the liquid crystal alignment film Other polyamic acid or imidized polymer other than polyamic acid or imidized polymer containing a structure derived from carboxylic dianhydride may be contained. Such other polyamic acid or imidized polymer may be one kind or plural kinds depending on the purpose, in particular 1, 2, 3, 4-cyclobutane tetracarboxylic dianhydride, 1, 3-dimethyl-1, 2, 3,4-cyclobutanetetracarboxylic dianhydride, 1, 2, 4, 5-cyclohexanetetracarboxylic dianhydride, 2, 3, 5-tricarboxycyclopentylacetic acid dianhydride, 1, 3, 3 a , 4, 5, 9 b-Hexahydro-5- (tetrahydro-1,2,5-dioxone 3-furanyl) one naphtho [1,2-c] furan 1,3-dione, 1, 3, 3 a, 4, 5, 9b-Hexahydro-8-methyl-5_ (tetrahydro-1,2,5-dioxo_3-furanyl) mononaphtho [1,2-c] furan 1,3-dione, 3-oxabicyclo [3.2 1] o Quan _ 2, 4-dione one 6-spiro one 3,-(tetrahydrofuran one 2 ', 5'-dione), 3, 5, 6-trioxyloxy 2-carboxynorporanone 2: 3, 5: 6-dianhydride, bicyclo [3. 3. 0] octane 1, 2, 4, 6, 8-tetracarboxylic acid One or more acid dianhydrides selected from dianhydride and pyromellitic dianhydride, p-phenylenediamine, 4, 4, —diaminodiphenyl methane, 4, 4′—diaminodiphenyl Rufido, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4, -diaminodiphenyl ether, 9, 9 —bis (4-aminophenyl) fluorene, 2, 2 -bis [ 4- (4-aminophenyl) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4, 4, 1-diamino-2, 2 '1-bis (trifluoromethyl) bihue It is obtained by reacting one or more diamines selected from 1,4,4-diamino-2,2,1-dimethylbiphenyl and 3,3- (tetramethyldisiloxane-1,3-diyl) bis (propylamine). It is preferable to add one or more polyamic acids. The amount of the polyamic acid or imidized polymer not containing the unit derived from the aliphatic tetracarboxylic dianhydride represented by the above formula (1) is the aliphatic tetracarboxylic acid represented by the above formula (1). Derived from dianhydride Preferably 100 to 90 parts by weight, more preferably 25 to 500 parts by weight, particularly preferably 100 to 40 parts by weight relative to 100 parts by weight of the total amount of the polymer containing the unit. 0 parts by weight.

 The liquid crystal aligning agent of the present invention improves the initial voltage holding ratio, the amount of change in the voltage holding ratio when a heat stress is applied to the liquid crystal display element or the liquid crystal display element is driven for a long time. In order to reduce (provide high reliability), a compound having an epoxy group may be added. Examples of the compound having an epoxy group include ethylene glycol diglycidyl ether, polyethylene dallicol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether. Ether, 1,6 monohexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4 monohexanediol , N, N, Ν ', Ν' -tetraglycidyl m-xylene diamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, Ν ', Ν, monotetraglyci Giraud 4, 4, Nodiphenylmethane, Ν, Ν, Ν ', Ν, Tetraglycidyl 4,4, —Diaminobenzene, Ν, Ν, Ν', Ν, Tetraglycidyl 4,4 'Diaminodiphenyl, テ ル, N, N, N′-tetraglycidyl-2,2′-dimethyl-4,4, -daminobiphenyl and the like can be mentioned as preferable ones. Among these compounds having an epoxy group, a compound having an epoxy group containing a nitrogen atom in a molecule having a diamine skeleton as a mother nucleus because of its excellent reactivity with the polyamic acid and imidized polymer of the present invention. Is particularly preferred. The addition amount of the compound having an epoxy group is preferably 0 to 60 parts by weight, more preferably 5 to 50 parts by weight with respect to 100 parts by weight of the total amount of the polyamic acid and imidized polymer of the present invention. It is.

Furthermore, from the viewpoint of improving the adhesion to the substrate surface, the liquid crystal aligning agent of the present invention may contain a functional silane compound force S, such as a 3-amino compound. Provirtrimethoxysilane, 3-aminoprobilt Lilietotoxixisilaran, 22——Aminminonoproprobivir torrimemetoxixisilaran, 22——Amimino Nobuboropi Liltotrioxy etoxytoxisilane, NN—— ((22—Aamiminonoethylyl)) -1 33——Amminonopropropyriltotrilimetometoxylsilalan, NN—— ((22 __ Aminominoethyl) ) ——33——Ammino-no-propropipyrmemethicylludidimetometoshishishishiranran, 33——Urelaididoproprobivir torrimetoxixicilane, 33——Uu Raido Dopporopipizozoretoto Lilieretokishishishiranran, NN—Eetotoxicar popo nil roux 33——Alumino nooploropi Lultrolimethometoxici Cisilaran, NN——Etotoxicar carpolineil 33——Alumino-Noppropyropirtotrilier etoxysicilane, NN

1-100——Torrieza Tode Power Force 11, 44, 77——Torrieza Tode Power Force, 99— LILIRULE 33, 66——Diazazanononyl acetylate, 99 TRITRILE ETOTOXYSIS LILILL——33, 66 1 diaza nononyl acetylase Tate, NN——Bebendizil 1—33——Amiminonoproprobivir Tortilimemetoxixisilaran, NN——Bebendizil 1—— Kishishishiranran, NN 1 Fuyen 22 Lulu 33——Family Minopropiruluto Tririmetometo Shishiranan, NN——Huy Fu Lui 33——Ami-mi Nonopprolopipyrurttririetotoxixisilalan,

N-bis (oxyethylene) -13-aminomino trimethoxysilane, N-bis (oxyethylene) -13-aminopropyltriethoxysilane, and the like. The addition amount of these functional silane compounds is preferably 0 to 60 parts by weight, more preferably 0 to 50 parts by weight with respect to 100 parts by weight of the total amount of the polyamic acid and imidized polymer of the present invention. It is.

Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include the same solvents as those exemplified as those used in the polyamic acid synthesis reaction. Among these, from the viewpoint of printability, the solvent power is preferably at a boiling point of 160 or higher. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, aminobutyrolactone, tetramethylurea, hexane. Methyl phosphortriamide, m-cresol, xylenol, phenol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-monobutanediol, triethylene glycol, diacetone alcohol, butyl lactyl, butyl acetate, ethyl ethoxypropio Nate, propylene carbonate, cetyl oxalate, jetyl malonate, ethylene glycol Cole monobutyl ether (Ptylcetone solve), Diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, Diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, Diethylene glycol monomethyl ether acetate, Jetylene glycol monoethyl ether acetate, Examples include 1,4-dichlorobutane and o-dichlorobenzene. Of these, N-methyl-2-pyrrolidone, carbyrolactone, diacetone alcohol, ethylene glycol monobutyl ether (ptylcellosolve), propylene carbonate, and diethylenedaricol jetyl ether are preferred. A particularly preferred solvent composition is a composition obtained by combining the above-mentioned solvents, in which a polymer does not precipitate in the aligning agent, and the surface tension of the aligning agent is in the range of 25 to 4 O mN / m. It is such a composition.

 The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of the components excluding the organic 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. The force 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 film thickness of this coating film is If the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film can be obtained. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.

 Viscosity of the liquid crystal aligning agent of the present invention The viscosity measured at 25 ° C. using a rotary viscometer as the G night crystal aligning agent must be appropriately adjusted according to the method of applying the liquid crystal aligning agent. Is preferably 3 to; L 0 O mPa · s, more preferably 3 to 5 OmPa · s, and particularly preferably 3 to 35 mPa · s.

The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, in the case of the spinner method, 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 5 OmPa · s. In the case of the ink jet method, the solid content concentration is 1 to 5% by weight. It is particularly preferred that the solution viscosity be in the range of 3-15 mPa-s.

 The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C to 200 ° C, more preferably 10 ° C to 100 ° C, and particularly preferably 20 ° C to 60 ° C.

<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 coating method, a spinner method, a printing method, an inkjet method, etc. A coating film is formed by heating the coated surface. Here, as a method of applying the liquid crystal aligning agent to the substrate, the spinner method is preferable for a small substrate, the printing method force is preferable for a medium size substrate, and the ink jet method force is applied to a large substrate. s preferred. 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, polycarbonate, or cyclic polyolefin can be used. As the transparent conductive film provided on one surface of a substrate, NESA film made of tin oxide (Sn_〇 ₂₎ (US PPG registered trademark), indium tin monoxide oxidation _{(I n 2 0 3 - S} nO 2) consisting of I A TO film or the like can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. For the reflective electrode, metals such as A 1 and Ag, or alloys containing these metals can be used. However, it is not limited to these as long as it has sufficient reflectivity. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film or reflective electrode and the coating film, a functional silane compound, a functional titanium compound or the like is previously applied to the surface of the substrate. It may be applied. After applying the liquid crystal aligning agent, preheating is usually performed for the purpose of preventing dripping of the applied aligning agent. The pre-baking temperature is preferably 30 to 300 ° C, more preferably 40 to 200 ° C, and particularly preferably 50 to 150 ° C. That Then, a baking (post-bake) process is performed for the purpose of completely removing the solvent. This firing temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. Thus, the liquid crystal aligning agent of the present invention forms a coating film that becomes an alignment film by removing the organic solvent after coating, but the liquid crystal aligning agent of the present invention is a polyamic acid or an imidized polymer having a low imidization rate. In the case of containing a coalescence, the film can be further heated to cause dehydration ring closure to proceed to form a more imidized coating film. The film thickness of the coating film to be formed is preferably from 0.001 to 1 / m, and more preferably from 0.05 to 0.5 m.

 (2) The orientation angle of the liquid crystal molecules can be controlled by rubbing the surface of the formed coating film by rubbing in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon and cotton. In addition to the rubbing method, a method of controlling the alignment ability by irradiating the surface of the coating film with polarized ultraviolet light can be applied. In order to remove the fine powder (foreign matter) generated during the rubbing process and clean the surface of the coating film, the formed liquid crystal alignment film should be washed with isopropyl alcohol and Z or pure water. Is preferred. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is partially irradiated with ultraviolet rays as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-2 2 2 3 6 6 and Japanese Patent Application Laid-Open No. 6-2 8 1 9 3 7. A resist film is partially applied on a liquid crystal alignment film that 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. 5-107504. After the rubbing process is performed in a direction different from the previous rubbing process, the resist film is removed and a process for changing the alignment ability of the liquid crystal alignment film is performed. It is possible to improve the visual characteristics.

(3) Two substrates on which the liquid crystal alignment film is formed as described above are produced, the two substrates are arranged opposite to each other with a gap (cell gap) therebetween, and the peripheral part of the two substrates is sealed with a sealant. The liquid crystal is formed by 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 disposing a polarizing plate on the outer surface of the liquid crystal cell, that is, on the outer surface side of each substrate constituting the liquid crystal cell. Here, as the sealant, for example, an epoxy resin containing a hardener and aluminum oxide spheres as a spacer can be used.

 Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals. 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, and pyrimidine liquid crystal. Dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like can be used. Cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; trade names “C-1 5” and “CB-1 5” (manufactured by Merck) It may be used by adding a ferroelectric night crystal such as p-decyloxybenzylidene p-amino-2-methylbutyl cinnamate.

 As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film called a “coating film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films or A polarizing plate made of the film itself can be mentioned. Example

 EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The measurement of imidization ratio, voltage holding ratio, reliability evaluation of voltage holding ratio, and printability test in Examples and Comparative Examples were evaluated by the following methods.

[Measurement of imidization rate]

After the polymer was dried under reduced pressure at room temperature, deuterated dimethyl sulfoxide (DM SO-d ₆ ) was used with a superconducting nuclear magnetic resonance absorber (NMR, manufactured by Nippon Denshi Co., Ltd., trade name: EX-9OA). ), ¹ H-NMR was measured using tetramethylsilane as a reference substance. In the obtained data, the NH-derived protons in the polymer —Imidation ratio was calculated from the ratio of the peak area (around 1 O ppm) to the peak area derived from other protons.

[Measurement of voltage holding ratio]

 After applying a voltage of 5 V to the liquid crystal display element with an application time of 60 msec and a span of 16 msec, the voltage holding ratio after 1 m7 msec after the application release is 60 ° C Measured under atmosphere. The measuring device used was VHR-1 manufactured by Toyo Corporation. When the voltage holding ratio was 99.0% or more, it was judged as “good”, and other cases were judged as “bad”. [Reliability evaluation of voltage holding ratio]

 After measuring the voltage holding ratio by the above measurement method, the produced liquid crystal display element was stored in a constant temperature oven at 100 ° C. for 10 days, applied with thermal stress, and then allowed to cool to room temperature. The voltage holding ratio of the liquid crystal display element was measured again by the above measurement method, and the amount of change in the voltage holding ratio before and after thermal stress was calculated. When the amount of change in the voltage holding ratio was within 5% of the initial value, it was judged as “good”, and other cases were judged as “bad”.

[Printability test]

Each liquid crystal aligning agent (total solid content concentration adjusted to 4.5-6.5 wt%) prepared in the following examples and comparative examples is used as a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd.). Then, an ITO film with a thickness of 200 nm and a width of 20 / zm was applied to the transparent electrode surface of a glass substrate with a transparent electrode formed in stripes at intervals of 100 m, and then heated on a hot plate. Preliminary drying was performed at 80 ° C. for 1 minute, followed by baking at 20 ° C. for 10 minutes on a hot plate to form a liquid crystal alignment film having a thickness of about 60 nm. The periphery and center of this liquid crystal alignment film were observed with a microscope with a magnification of 20 times, and when there was no coating unevenness, it was judged as “good”, and when there was coating unevenness, it was judged as “bad”. The results of evaluating the printability of each liquid crystal alignment agent are summarized in Table 2. Synthesis Example 1 (Synthesis of polyamic acid P-1) Tetracarboxylic dianhydride represented by the above formula (2) as a tetracarboxylic dianhydride 35. 913 g (0.1709 mol), pyromellitic dianhydride 12.4 33 g (0.0570 mol) P-Phenylenediamine as a diamine 18.860 g (0.1744 mol), and 30.3 76 g (0.0581 mol) of a diamine represented by the above formula (17) 400 g of N-methyl-2-pyrrolidone And reacted at 60 ° C for 4 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. After washing with methyl alcohol and drying at 40 ° C under reduced pressure for 24 hours, 88 g of polyamic acid having a logarithmic viscosity of 0.70 dl / g (referred to as “polymer P-1”) was added. Obtained. Synthesis Example 3 (Synthesis of imidized polymer P-3)

 Tetracarboxylic dianhydride represented by the above formula (3) as tetracarboxylic dianhydride 25. 690 g (0. 0930 mol), p-phenylenediamine as diamine 9.2 135 g (0. 0852 mol) ), 4.9688 g (0.0053 mol) of diamine represented by the above formula (17) was dissolved in 140 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 5 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 under reduced pressure at 40 ° C. for 24 hours to obtain 31 g of polyamic acid having a logarithmic viscosity of 0.72 d 1 / g. 30 g of the resulting polyamic was dissolved in 400 g of N-methyl-2-pyrrolidone, added with 6.3 g of pyridine and 8.1 g of acetic anhydride, dehydrated and closed at 110 ° C for 4 hours. Precipitation, washing, and decompression were carried out to obtain 26 g of an imidized polymer having a logarithmic viscosity of 0.68 d 1 / g and an imidization ratio of 48% (referred to as “Polymer P-3”). Synthesis Example 6 (Synthesis of imidized polymer P-6)

Tetracarboxylic dianhydride represented by the above formula (2) as the tetracarboxylic dianhydride 16. 7061 g (0.0795 mol), p-phenylenediamine as the diamine 2.9198 g (0.0270 mol), Represented by the above formula (17) Diamine 6.22216 g (0.0119 mol), 4,4,1-diaminodiphenylmethane 7.8713 g (0.00397 mol) and aniline 0.1480 g (0.0016 mol) N as end-modifying monoamine -Methyl-2-pyrrolidone was dissolved in 140 g and reacted at 60 for 4 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 under reduced pressure for 24 hours to obtain 32 g of polyamic acid having a logarithmic viscosity of 0.60 dlZg. 30 g of the resulting polyamic was dissolved in 400 g of N-methyl-2-pyrrolidone, 10.8 g of pyridine and 13.9 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. Then, precipitation, washing, and decompression were carried out to obtain 27 g of an imidized polymer having a logarithmic viscosity of 0.55 dlZg and an imidization ratio of 75% (hereinafter referred to as “polymer P-6”). Synthesis Example 2, Synthesis Examples 4 and 5, and Synthesis Examples 7 to 14, Comparative Synthesis Examples 1 to 5

 The polyamic acid and imidized polymer shown in Table 1 were the same as in Synthesis Example 1, Synthesis Example 3 and Synthesis Example 6 except that tetracarboxylic dianhydride and diamine were changed to those shown in Table 1, respectively. (These were referred to as polymers “P-2”, “P-4”, “P-5”, and “P_7” to “P-19”, respectively). Each polymer has a viscosity described in Table 1 by appropriately adjusting the weight ratio of tetracarboxylic dianhydride and diamine used when synthesizing the corresponding polyamic acid. I was able to. In addition, each polymer having the imidization rate shown in Table 1 could be obtained by appropriately adjusting the addition amounts of pyridine and acetic anhydride. In Table 1, tetracarboxylic dianhydrides A to F and diamines G to M represent the following compounds, respectively.

 Acid dianhydride A Tetracarboxylic dianhydride represented by the above formula (2) Acid dianhydride B Tetracarboxylic dianhydride represented by the above formula (3) Acid dianhydride C 2, 3, 5 — 卜 Carboxycyclopentylacetic acid dianhydride Acid dianhydride D Pyromellitic dianhydride

Acid dianhydride E: 1, 2, 3, 4-cyclobutanetetracarboxylic dianhydride Acid dianhydride F: 1, 3, 3 a, 4, 5, 9 b-Hexahydro-8-methyl-5- (tetrahydro-1,5-dioxo-3-furanyl) mononaphtho [1, 2-c] Franc 1,3—Dione

 Jiamin G: Jiamin represented by the above formula (17)

 Jiamin H: p-Fujire Hajamin

 Jiamin I: 4, 4 'Jifu' Minodiphenylmethane

 Jiamin J: Jiamin represented by the above formula (15)

 Jiamin K: Jiamin represented by the above formula (27)

 Jiamin L: Jiamin represented by the following formula (28)

 Jiamin M: 2, 2'-dimethyl-4, 4 '

(28)

Table 1 Acid dianhydride diamine and: Γ-min

 () Indicates total acid dianhydride () indicates total diamine + amino logarithmic viscosity polymer

 Indicates the molar ratio of the amount to the amount of substance (dl / g)

 Indicate the ratio

 Synthesis Example 1 P— 1 A (75), D (25) G (25), H (75) 0.70 0 Synthesis Example 2 P— 2 B (100) G (50) H (50) 0. 73 0 Synthesis Example 3 P-3 B (100) G (10), H (90) 0.668 48 Synthesis Example 4 P— 4 A (100) G (20), H (80) 0.60 50 Synthesis Example 5 P -5 A (100) G (10), H (70), 1 (20) 0.64 79

 G (15), H (34), 1 (50)

 Synthesis Example 6 P-6 A (100) 0.5 55 75 Fanrin (2)

 Synthesis Example 7 P-7 D (50), E (50) I (100) 0.772 0 Synthesis Example 8 P-8 B (100) H (100) 0.81 91

 J (1.5), K (10), H (87)

 Synthesis Example 9 P—9 A (50), F (50) 0. 50 95 Stearylamine (3)

 K (10) Η (88.5)

 Synthesis Example 10 P— 10 A (50), F (50) 0.48 94 Stearylamine (3)

 L (3), Κ (10),

 Synthesis Example 11 P-11 A (50), F (50) 0.52 89

 Η (86 25), Anilin (1.5)

 L (5), K (10),

 Synthesis Example 12 P— 12 B (50), F (50) 0. 50 90

 Η (84.25), Anilin (1.5)

 Synthesis Example 13 P— 13 E (100) Μ (100) 0. 85 0 Synthesis Example 14 P— 14 D (50), E (50) Μ (100) 0.90 0 Comparative Synthesis Example 1 P— 15 C ( 100) G (20), Η (80) 0.62 cv, 50 Comparative Synthesis Example 2 P— 16 C (100) G (10), Η (70), 1 (20) 0.64 1 78 Comparative Synthesis Example 3 P-17 C (100) Η (100) 0. 79 90

 J (1.5), Κ (10), Η (87)

Comparative Synthesis Example 4 P—18 C (50), F (50) 0.52 92 Stearylamine (3)

 Κ (10), Η (88.5)

Comparative Synthesis Example 5 P-19 C (50), F (50) 0.51 93 Stearylamine (3) Example 1

 The polymer (P-1) obtained in Synthesis Example 1 is mixed with N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether so that the mixing weight ratio of N-methyl-2-pyrrolidone-ethylene ethylene glycol monobutyl ether is 30/70. In addition, 20 parts by weight of N, N, Ν ', Ν, -tetraglycidyl 1,4,4'-diaminodiphenylmethane is added to the polymer (Ρ-1) to obtain a solid content of 3.5. A liquid crystal aligning agent of weight% was used. However, when conducting the printability test, a liquid crystal aligning agent having a solid content concentration of 6.5% by weight was used. After sufficiently stirring this, it is filtered using a filter with a pore size of 0.2 m, applied onto a transparent conductive film made of an ITO film provided on one side of a glass substrate using a spinner, and on a hot plate. A transparent electrode substrate having a liquid crystal alignment film with a film thickness of 6 Onm after preliminary drying at 80 ° C for 1 minute and then baking in a clean oven (under nitrogen atmosphere) at 200 ° C for 1 hour It was created. Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 to the outer edges of the pair of transparent electrodes Z transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, The liquid crystal alignment film surfaces were overlapped and pressed together so that the adhesive was cured. Next, after filling negative type liquid crystal (MLC-2 038, manufactured by Merck & Co., Inc.) between the liquid crystal injection port and the substrate, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a VA type liquid crystal display device did. Table 2 shows the results of evaluating the voltage holding ratio and reliability of the obtained liquid crystal display device. Example 2

 A liquid crystal aligning agent and a VA liquid crystal display device of the present invention were obtained in the same manner as in Example 1 except that the polymer (P-2) obtained in Synthesis Example 2 was used instead of the polymer (P-1). It was. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device. Example 3

The polymer (P-3) obtained in Synthesis Example 3 was used instead of the polymer (P-1), The solvent composition is N-methyl-2-pyrrolidone Z-ethylene glycol monobutyl ether mixing weight ratio = 50 50, Ν, Ν, Ν ', N' —tetraglycidyl-4, 4 '— diaminodiphenyl A liquid crystal aligning agent and a V-type liquid crystal display device of the present invention were obtained in the same manner as in Example 1 except that no hydrogen was added. Table 2 shows the results of evaluating the voltage holding ratio and reliability of the obtained liquid crystal display device. Example 4

 Use the polymer (P-4) obtained in Synthesis Example 4 instead of the polymer (P-1), and change the solvent composition to N-methyl-2-pyrrolidone Z ethylene glycol monobutyl ether mixing weight ratio = 50Z. A liquid crystal aligning agent and a VA type liquid crystal display device of the present invention were obtained in the same manner as in Example 1 except that 50 was used. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device. Example 5

 The polymer (P-5) obtained in Synthesis Example 5 was used in place of the polymer (P-1), and the solvent composition was carbyrolactone ZN-methyl-2-pyrrolidone Z ethylene glycol monobutyl ether mixing weight ratio = A liquid crystal aligning agent and a VA liquid crystal display device of the present invention were obtained in the same manner as in Example 1 except that 40Z30 / 30 was used. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device. Example 6

Instead of the polymer (P-1), the polymer (P-6) obtained in Synthesis Example 6 and the polymer (P-7) obtained in Synthesis Example 7 were replaced with (P-6): (P-7) ) = 50: 50 (weight ratio), and the solvent composition was the same as in Example 1 except that the solvent composition was a captylolactone ZN-methyl-2-pyrrolidone Z ethylene glycol monoptyl ether mixed weight ratio = 40Z35Z25. A liquid crystal aligning agent and a VA type liquid crystal display element of the present invention were obtained. Table 2 shows the results of evaluating the voltage holding ratio and reliability of the obtained liquid crystal display device. Example 7

 To the polymer (P-8) obtained in Synthesis Example 8, aptyrolactone and ethylene glycol monobutyl ether were added so that the weight ratio of aptyrolactone / ethylene glycol monobutyl ether was 90Z10, and N, N, Ν ', N' —tetraglycidyl 4, 4 ′ —diaminodiphenylmethane is added in an amount of 10 parts by weight to the polymer (Ρ—8), and the liquid crystal alignment is 3.5% by weight in solid content. (However, when conducting the printability test, the liquid crystal aligning agent had a solid content of 4.5% by weight.) This was thoroughly stirred and then filtered using a filter having a pore size of 0.2 m to prepare the liquid crystal aligning agent of the present invention. The liquid crystal aligning agent of the present invention prepared as described above was applied onto a transparent conductive film made of an ITO film provided in a comb-teeth shape on one surface of a 1 mm thick glass substrate using a spinner, and 180 A film with a dry film thickness of 8 Onm was formed by drying at ° C for 1 hour. The formed coating surface was rubbed using a rubbing machine having a roll around which a nylon cloth was wound to obtain a liquid crystal alignment film. Here, the rubbing treatment conditions were a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a bristle foot pushing length of 0.4 mm. (This board is called board A)

 The liquid crystal aligning agent of the present invention prepared as described above was applied to one surface of a glass substrate having a thickness of 1 mm using a spinner, and dried at 180 ° C. for 1 hour to form a coating film having a dry film thickness of 8 Onm. Formed. The formed coating film surface was rubbed using a rubbing machine having a roll wound with a nylon cloth to obtain a liquid crystal alignment film. Here, the rubbing treatment conditions were a roll rotation speed of 400 rpm, a stage moving speed of 3 cmZ seconds, and a bristle foot pushing length of 0.4 mm. (This board is called board B)

After applying an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 17 m to the outer edge of the coating surfaces of substrates A and B by screen printing, the rubbing directions in the respective liquid crystal alignment films become antiparallel. As described above, the two substrates were arranged to face each other with a gap between them, the outer edges were brought into contact with each other, and the adhesive was cured by pressing. Next, nematic liquid crystal (Merck,

MLC-2019), the liquid crystal injection port is sealed with an epoxy adhesive, the polarizing plate is placed on both sides of the substrate, and the polarizing direction of the polarizing plate is the same as the rubbing direction of the liquid crystal alignment film of each substrate. Bonding was made so that they coincided, and an IPS type liquid crystal display device was produced. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display element. Example 8

Change the polymer (P-9) obtained in Synthesis Example 9 and the polymer (P — 13) obtained in Synthesis Example 13 to (P—9): (P—13) = 20: 80 (weight ratio). So that it is dissolved in alpha-propylolactone / N-methyl-2-pyrrolidone Z ethylene glycol monobutyl ether mixed solvent (solvent weight ratio 68 17/15), and N, N, Ν ', Ν, tetraglycidyl 2,4, -Diaminodiphenylmethane was added in an amount of 2 parts by weight based on the total amount of polymer to obtain a liquid crystal aligning agent having a solid content of 3.5% by weight. A liquid crystal aligning agent having a concentration of 6.0% by weight was prepared). This was sufficiently stirred and then filtered using a filter having a pore diameter of 0.2 m to prepare the liquid crystal aligning agent of the present invention. The above liquid crystal aligning agent is applied onto a transparent conductive film made of an IT film on one surface of a glass substrate using a spinner, preliminarily dried at 80 ° C. for 1 minute on a hot plate, and then hot A transparent electrode substrate having a liquid crystal alignment film with a film thickness of 60 nm was prepared by baking at 210 ° C. for 10 minutes on the plate. A rubbing machine having a roll in which a rayon cloth was wrapped around this film was rubbed once at a roll rotation speed of 400 rpm, a stage moving speed of 30 mm / sec, and a limb push-in length of 0.4 mm. The liquid crystal alignment film-coated substrate was ultrasonically cleaned in pure water for 1 minute and then dried in a clean oven at 100 ° C. for 10 minutes. Next, after applying a liquid crystal alignment film of the transparent electrode substrate to each outer edge having the liquid crystal alignment film of the coated substrate, an epoxy resin adhesive containing aluminum oxide with a diameter of 5.5 m and a spherical ball is applied. The liquid crystal alignment film surfaces were overlapped and pressed together so that the adhesive was cured. Next, between the liquid crystal injection port and the substrate, After filling with nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.), the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and a polarizing plate is bonded to both sides of the substrate, and a TN liquid crystal display element is formed. Produced. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device.

Example 9

 Instead of the polymers (P-9) and (P-13), the polymer (P-10) obtained in Synthesis Example 10 and the polymer (P-7) obtained in Synthesis Example 7 were 10): (P 1-7) = 50: 50 (weight ratio), N, N, Ν ', N' —tetraglycidyl 4,4, -diaminodiphenylmethane added to the total amount of polymer 20 The liquid crystal of the present invention was changed in the same manner as in Example 8 except that the solvent composition was changed to the weight ratio of aptilolactone ΖΝ-methyl-2-pyrrolidone Ζ ethylene dallicol monobutyl ether = 71Z17Z12. An aligning agent and a vertical liquid crystal display element were obtained. Table 2 shows the results of evaluating the voltage holding ratio and reliability of the obtained liquid crystal display device.

Example 10

 The polymer (Ρ-11) obtained in Synthesis Example 11 was used in place of the polymer (Ρ-9), and Ν, Ν, Ν, Ν, テ ト ラ tetraglycidyl-4,4, -diaminodiphenylmeth The amount of tan added was changed to 10 parts by weight based on the total amount of polymer. Furthermore, the liquid crystal aligning agent of the present invention and the cocoon type were the same as in Example 8 except that the solvent composition was a mixture weight ratio of α-propylolactone / Ν-methyl-2-pyrrolidone ethylene glycol monopropyl ether = 72/15/13. A liquid crystal display element was obtained. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device.

Example 11

The polymer (P-12) obtained in Synthesis Example 12 was used in place of the polymer () -9), and Ν, Ν, Ν ', N'-tetraglycidyl 4,4, -diaminodiphenyl ester was used. Example except that the addition amount of tan was changed to 10 parts by weight with respect to the total amount of the polymer, and the solvent composition was changed to aptyrolactone ZN-methyl-2-pyrrolidone / ethylene glycol monobutyl ether mixed weight ratio = 72/15/13 In the same manner as in Example 8, a liquid crystal aligning agent and a TN type liquid crystal display element of the present invention were obtained. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device.

Example 12

 The polymer (P-14) obtained in Synthesis Example 14 was used in place of the polymer (P-13), and the solvent composition was aptyrolactone ZN_methyl-2-pyrrolidone Z ethylene glycol. A liquid crystal aligning agent and a TN type liquid crystal display device of the present invention were obtained in the same manner as in Example 8 except that the mixing weight ratio of monobutyl ether was 72/16/12. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display element.

Comparative Example 1

 Use the polymer (P-15) obtained in Comparative Synthesis Example 1 instead of the polymer (P-1), and change the solvent composition to N-methyl-2-pyrrolidone Z ethylene glycol monobutyl ether mixing weight ratio = A liquid crystal aligning agent and a VA type liquid crystal display device were obtained in the same manner as in Example 1 except that 50/50. Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device.

Comparative Example 2

The polymer (P-16) obtained in Comparative Synthesis Example 2 was used in place of the polymer (P-1), and the solvent composition was mixed with aptyrolactone / N-methyl-1-pyrrolidone ethylene glycol monobutyl ether. A liquid crystal aligning agent and a VA type liquid crystal display device were obtained in the same manner as in Example 1 except that the ratio was 40/30/30. Table 2 shows the results of evaluating the voltage holding ratio and reliability of the obtained liquid crystal display device. Comparative Example 3

 A liquid crystal aligning agent and an IPS type liquid crystal display device were obtained in the same manner as in Example 7 except that the polymer (P-17) obtained in Comparative Synthesis Example 3 was used instead of the polymer (P-8). . Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device. Comparative Example 4

 A liquid crystal aligning agent and a TN type liquid crystal display device were obtained in the same manner as in Example 8 except that the polymer (P-18) obtained in Comparative Synthesis Example 4 was used instead of the polymer (P-9). . Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display element.

Comparative Example 5

A liquid crystal aligning agent and a TN type liquid crystal display device were obtained in the same manner as in Example 9 except that the polymer (P-19) obtained in Comparative Synthesis Example 5 was used instead of the polymer (P-10). Table 2 shows the results of evaluating the voltage holding ratio and the reliability of the obtained liquid crystal display device.

Table 2 Polymer Voltage holding ratio (VHR) Printability Imidization VHR Initial value VHR Polyamic acid

Polymer (%) Judgment Reliability Example 1 P— 1 — 99.1 Good Good Good Example 2 P— 2 1 99.2 Good Good Good Example 3 1 P— 3 99. 3 Good Good Good Example 4 1 P— 4 99. 6 Good Good Good Example 5 ― P-5 99. 8 Good Good Good Example 6 P— 7 P-6 99. 7 Good Good Good Example 7 One P— 8 99. 7 Good Good Good Example 8 P— 13 P-9 99. 3 Good Good Good Example 9 P-7 P— 10 99. 2 Good Good Good Example 10 P— 13 P-11 99. 5 Good Good Good Example 11 P -13 P— 12 99. 4 Good Good Good Example 12 P— 14 P-9 99. 3 Good Good Good Comparative Example 1 1 P-15 98. 3 Poor Non-People Non-People Comparative Example 2 P-16 98. 7 Poor Poor Non-Private Comparative Example 3 1 P— 17 98. 9 Poor Poor Good Comparative Example 4 P— 13 P— 18 98. 9 Poor Poor Good Comparative Example 5 P-7 P— 19 98. 7 Poor Poor Good

From the results of Table 2 above, the liquid crystal alignment films obtained from the liquid crystal alignment agents obtained in Examples 1 to 12 show a higher voltage holding ratio and better reliability than those of the comparative examples. In addition, it is clear that the coating property of an excellent liquid crystal aligning agent is exhibited. It is clear that the characteristics of the liquid crystal aligning agent of the present invention can be adjusted by selecting the structure of the tetracarboxylic dianhydride represented by the above formula (1) and its content.

 As described above, according to the present invention, it is possible to provide a liquid crystal aligning agent having a high voltage holding ratio and excellent in the coating property of the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal aligning film and having a beautiful image. It was shown that there is.

Claims

1. One or more aliphatic tetracarboxylic dianhydrides represented by the following formula (1) and other tetra-force ruponic dianhydrides and ρ-phenylenediamine and other as required It contains at least one polymer selected from at least one polymer selected from polyamic acid obtained by polyaddition reaction of diamine and imidized polymer obtained by imidizing the polyamic acid.

 The liquid crystal aligning agent characterized by the above-mentioned.

 Demand

Surrounding

(In the formula, R ¹ to R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and m and η each independently represent an integer of 0 to 3)

2. The liquid crystal aligning agent according to claim 1, wherein the aliphatic tetracarboxylic dianhydride represented by the above formula (1) is a compound represented by the following formula (2).

3. The liquid crystal aligning agent according to claim 1, wherein the aliphatic tetracarboxylic dianhydride represented by the above formula (1) is a compound represented by the following formula (3).

4. The liquid crystal aligning agent according to any one of claims 1 to 3, comprising a diamine having a pretilt angle-expressing part represented by the structure of the following formula (13) as another diamine.

(Wherein R ⁷ and R ⁸ are each independently a hydrogen atom or a methyl group, R ⁹ is a linear or branched alkyl group having 1 to 20 carbon atoms, and R ^1Q and R ¹¹ are Each independently is a divalent organic group)

5. The liquid crystal alignment according to any one of claims 1 to 3, comprising a diamine having a pretilt angle-expressing portion represented by the structure of the following formula (14) as another diamine.

(Wherein, a is 0 or 1, and R ¹² is an ether bond (—〇—), a strong sulfonyl group (—CO—), a strong sulfonyloxy group (one COO—), an oxycarbonyl group (—OC O—), amide bond (—NHCO—, —CONH—), thioether bond (—S 1) and a divalent linking group or organic group selected from a methylene group, R ¹³ is different from R ¹² R ¹⁴ is a group selected from a group having a steroid skeleton, a group having a fluorine atom, and a group having a linear or branched alkyl group having 1 to 30 carbon atoms.)

6. The liquid crystal aligning agent according to any one of claims 1 to 3, further comprising at least one epoxy group-containing compound having two or more epoxy groups in the molecule.

7. A liquid crystal alignment film formed from the liquid crystal aligning agent according to any one of claims 1 to 3.

8. A liquid crystal display device comprising the liquid crystal alignment film according to claim 7.