KR101397293B1 - Liquid crystal aligning agent and liquid crystal display device - Google Patents

Abstract

The present invention provides a liquid crystal aligning agent having improved printability while reducing the accumulated charge while maintaining the voltage holding ratio.

The liquid crystal aligning agent of the present invention is characterized by containing a polyamic acid obtained by reacting a compound represented by the following formula (1) or a compound represented by the following formula (1 ') with a tetracarboxylic dianhydride.

≪ Formula 1 >

(Wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, and R ⁴ to R ⁷ each independently represent a monovalent aliphatic group having a hydrogen atom, a monovalent aromatic group, a monovalent aliphatic group or an epoxy group A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom, a monovalent aliphatic group or an epoxy group, and n is an integer of 1 to 100)

≪ Formula (1) >

(Wherein R ¹ to R ³ , A ¹ and A ² and n are the same as in the above formula 1)

Liquid crystal aligning agent, liquid crystal display element, polyamic acid

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal aligning agent and a liquid crystal display element,

The present invention relates to a liquid crystal aligning agent and a liquid crystal display element used for forming a liquid crystal alignment film of a liquid crystal display element. More particularly, the present invention relates to a liquid crystal aligning agent which provides a liquid crystal alignment film having good electrical properties and good printability, and a liquid crystal display device using the same.

At present, as a liquid crystal display element, a liquid crystal alignment film containing polyamic acid, polyimide or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a substrate for a liquid crystal display element, Called Twisted Nematic (Twisted Nematic) type in which a layer of a nematic liquid crystal having dielectric anisotropy is formed into a cell having a sandwich structure and the long axis of the liquid crystal molecule is continuously twisted by 90 degrees from one substrate toward the other substrate A TN type liquid crystal display element having a liquid crystal cell is known. In addition, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have higher contrast and less visual dependency than TN type liquid crystal display elements, have been developed. The STN-type liquid crystal display device uses a liquid crystal in which a chiral agent as an optically active substance is blended with a nematic liquid crystal so that the long axis of the liquid crystal molecules is continuously twisted over 180 degrees between the substrates to produce a birefringence effect .

On the other hand, as described in Non-Patent Documents 1 and 2, a vertical alignment called a MVA (Multi-Domain Vertical Alignment) method in which protrusions are formed on a transparent conductive film to control the alignment direction of the liquid crystal Type liquid crystal display device has been proposed. The MVA type liquid crystal display device is excellent in viewing angle, contrast and the like, and is also excellent in manufacturing processes such as no rubbing treatment in forming a liquid crystal alignment film. As a liquid crystal alignment film preferable for the TN, STN and MVA methods, a performance such as a short afterglow time of a liquid crystal display element is required. In addition, as an alignment agent used for forming these liquid crystal alignment films, excellent printability in offset printing is required.

[Non-Patent Document 1] "Liquid crystal" Vol. 3, No. 2, 117 (1999)

[Patent Document 1] JP-A-11-258605

[Patent Document 2] JP-A-6-222366

[Patent Document 3] Japanese Unexamined Patent Application Publication No. 6-281937

[Patent Document 4] JP-A-5-107544

[Non-Patent Document 2] K. Hasegawa, Polymer Journal. Vol. 31, No. 2, 206 (1999)

[Patent Document 5] Japanese Unexamined Patent Publication No. 2000-44683

[Patent Document 6] International Publication No. 2002/100949

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a liquid crystal aligning agent with reduced printing durability while maintaining the voltage holding ratio, and a liquid crystal display element using the liquid crystal aligning agent.

Other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above object of the present invention is achieved firstly by a liquid crystal aligning agent containing a compound represented by the following general formula (1) (hereinafter referred to as "first liquid crystal aligning agent").

(Wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, and R ⁴ to R ⁷ each independently represent a monovalent aliphatic group having a hydrogen atom, a monovalent aromatic group, a monovalent aliphatic group or an epoxy group A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom, a monovalent aliphatic group or an epoxy group, and n is an integer of 1 to 100)

The object of the present invention is secondly to provide a liquid crystal aligning agent which comprises a polyamic acid obtained by a reaction between a compound represented by the following formula (1 ') and a tetracarboxylic dianhydride (hereinafter referred to as "second liquid crystal alignment Quot;).

≪ Formula (1) >

(Wherein R ¹ to R ³ , A ¹ and A ² and n are the same as in the above formula 1)

The above object of the present invention is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from any one of the liquid crystal aligning agents.

The first liquid crystal aligning agent of the present invention contains the compound represented by the above formula (1).

In the general formula (1), R ¹ to R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group.

The alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, - pentyl group, n-hexyl group and the like.

The alkoxyl group is preferably an alkoxyl group having 1 to 6 carbon atoms. Specific examples thereof include a methoxyl group, an ethoxyl group, an n-propoxyl group, an isopropoxyl group, an n-butoxyl group, Methyl-propoxyl group, n-pentyl group, n-hexyloxyl group and the like.

R ⁴ to R ⁷ in Formula 1 are each independently a monovalent aliphatic group having a hydrogen atom, a monovalent aromatic group, a monovalent aliphatic group or an epoxy group.

Examples of the monovalent aromatic group include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthrene group, a pyrene group, a perylene group, an anthracene group and a fluorene group. A terphenyl group, a naphthyl group or a fluorene group is preferable.

The monovalent aliphatic group is preferably a monovalent aliphatic group having 1 to 4 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group.

As the monovalent aliphatic group having an epoxy group, the total number of carbon atoms is preferably 2 to 4, and examples thereof include a glycidyl group and a 1-methylglycidyl group.

In Formula 1, A ¹ and A ² each independently represent a monovalent aliphatic group having a hydrogen atom, a monovalent aliphatic group or an epoxy group. Preferred monovalent aliphatic groups having A ¹ and A ² and monovalent aliphatic groups having an epoxy group are the same as those described above as preferred monovalent aliphatic groups having R ⁴ to R ⁷ and monovalent aliphatic groups having an epoxy group.

N in the above formula (1) is an integer of 1 to 100, preferably 1 to 50.

In the above formula (1), R ¹ to R ⁷ and A ¹ and A ² may be any combination of any desired ones.

Among the compounds represented by the above formula (1), the following compounds (A) to (D) are more preferred.

(A) and in the general formula 1, R ¹ to R ³ are each independently a hydrogen atom, an alkoxy group of the alkyl group or 1 to 6 carbon atoms of 1 to 6 carbon atoms, R ⁴ to R ⁷ is a hydrogen atom, A ¹ and A ² is a hydrogen atom.

(B) a compound represented by the general formula (1) wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ to R ⁷ are monovalent aliphatic groups having an epoxy group , And A < ¹ > and A < ² > are each independently a hydrogen atom or a monovalent aliphatic group having an epoxy group.

(C) a compound represented by the general formula (1) wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, R ⁴ and R ⁶ are monovalent aromatic groups, R ⁵ and R ⁷ are each a hydrogen atom or a monovalent aliphatic group, and A ¹ and A ² are each independently a hydrogen atom or a monovalent aliphatic group.

(D) a compound represented by the general formula (1) wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, R ⁴ and R ⁶ are monovalent aromatic groups, R ⁵ and R ⁷ are each a monovalent aliphatic group having a hydrogen atom or an epoxy group, and A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom or an epoxy group. In this case, preferably, a compound in which all of R ⁵ , R ⁷ , A ¹ and A ² are hydrogen atoms is excluded.

Preferable specific examples of the compound represented by the formula (1) include, for example, compounds represented by the following structural formulas.

(In the above chemical formula group, n is an integer of 1 to 100, preferably 1 to 50)

The second liquid crystal aligning agent of the present invention contains a polyamic acid obtained by reacting the compound represented by the formula (1 ') with a tetracarboxylic dianhydride. "As the compound represented by the formula (1) 'of the chemical formula 1, and R ¹ to R ³ are each independently a hydrogen atom, an alkoxyl group having 1 to 6 carbon atoms alkyl or 1-6 carbon atoms in the, A ¹ and A ² is A hydrogen atom and a compound wherein n is 1 to 50 are preferable.

Preferable specific examples of the compound represented by the formula (1 ') include, for example, compounds represented by the following structural formulas.

(In the above chemical formula group, n is an integer of 1 to 100, preferably 1 to 50)

Examples of the tetracarboxylic acid dianhydride that can be used in the synthesis of the polyamic acid by the reaction between the compound represented by the formula (1 ') and the tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxyl 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5 , 9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] furan-1,3-dione, cis-3,7-dibutyl 1,5-diene-1,2,5,6-tetracarboxylic acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: Water, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ (3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '- (tetrahydrofuran-2', 5'- , 5-dioxotetrahydro-3-furanyl) -3-methyl-3- Hexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3. 1.0 ^2,6 " undecane-3,5,8,10-tetraone, pyromellitic acid dianhydride and the like. These acid anhydrides may be used alone or in combination of two or more.

In the synthesis of the polyamic acid by the reaction between the compound represented by the formula (1 ') and the tetracarboxylic dianhydride, other diamines may be used together with the compound represented by the formula (1'). Preferable examples of other diamines usable herein include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 2,2'-dimethyl- 4,4'-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4'- Phenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9- ) Phenyl hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '- (p-phenylenediisopropylidene) (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) benzene, Aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6- N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl- Aminophenyl) -benzidine, and N, N'-di (4-aminophenyl) -N, N'-dimethyl-benzidine. These other diamines may be used alone or in combination of two or more.

When other diamines are used together with the compound represented by the formula (1 '), the amount of the other diamine to be used is preferably 50% by weight or less based on the total amount of the compound represented by the formula (1') and other diamines.

The synthesis of the polyamic acid from the compound represented by the formula (1 ') and the tetracarboxylic dianhydride can be carried out in the same manner as the below-described method for synthesizing polyamic acid, which is one of optional components of the liquid crystal aligning agent of the present invention .

The liquid crystal aligning agent of the present invention contains, as an essential component, a compound represented by the formula (1) or a polyamic acid obtained by a reaction between the compound represented by the formula (1 ') and a tetracarboxylic dianhydride. At least one member selected from the group consisting of a polyamic acid having a repeating unit represented by the following formula (1a) and a polyimide having a repeating unit represented by the following formula (1b), an adhesion improver, and the like.

(Wherein P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group)

(Wherein P ² is a tetravalent organic group and Q ² is a divalent organic group)

The polyamic acid having a repeating unit represented by the above formula (1a) can be synthesized by reacting a tetracarboxylic dianhydride with a diamine, and the polyimide having a repeating unit represented by the above formula (1b) and ¹ is P ^2, Q ¹ has a ring closure can be obtained by dehydrating a polyamic acid having a repeating unit Q ^2.

Examples of the tetracarboxylic acid dianhydride used in the synthesis of the polyamic acid having the repeating unit represented by the above formula (1a) include alicyclic tetracarboxylic dianhydride, aliphatic tetracarboxylic acid dianhydride, aromatic tetracarboxylic acid Water and the like.

Examples of the alicyclic tetracarboxylic acid dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylate 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4 , 5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1 , 2,5,6-tetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5 : 6-dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetra 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- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [l, 2-c] , 5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ 3,3a, 4,5,9b-hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ -Dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3- furanyl) 3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ , 2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (tetrahydro- Yl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5- dioxotetrahydrofural) -3-methyl- Hexene-1,2-dicarboxylic acid dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 3-oxabicyclo [3.2. (Tetrahydrofuran-2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3 -Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: Oxetricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, a compound represented by the following formula (I) or (II), and the like.

(Wherein R ⁸ and R ¹⁰ are divalent organic groups having aromatic rings, R ⁹ and R ¹¹ are each a hydrogen atom or an alkyl group, and a plurality of R ^{9 s} and R ^{11 s present} may be the same or different)

Examples of the aliphatic tetracarboxylic acid dianhydride include butane tetracarboxylic dianhydride and the like.

Examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyl Sulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3 ', 4,4'- Biphenyl ether tetracarboxylic acid dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic acid dianhydride , 1,2,3,4-furantetracarboxylic acid dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis -Dicarboxyphenoxy) diphenyl sulfone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropyl Dendritic phthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracar Bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene- Diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis Bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate) , Bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), and compounds represented by the following chemical formulas (2) to (5).

These tetracarboxylic acid dianhydrides may be used singly or in combination of two or more.

Examples of the alicyclic tetracarboxylic acid dianhydride in the tetracarboxylic acid dianhydride include 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclo Butanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid Dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride , Cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane- 2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) - Naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro (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 acid dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione- 3-methyl-3-cyclohexene-1, 2-dicarboxylic acid anhydride, 3 (3-methyl-3-furyl) , 5,6-tricarboxy-2-carboxy norbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8 (9) among the compounds represented by the following formulas (6) to (8) or the compounds represented by the above formula (II) among the compounds represented by the above formula (I) Is preferable in view of being able to exhibit good liquid crystal alignability. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4- Cyclobutane tetracarone 1,3,5-tris (hydroxymethyl) -2,5-dioxo-3- (2-methyl-3- Furanyl) -naphtho [1,2-c] furan-1,3-dione, 3,5,6-tricarbonyl-2-carboxynorbornane- , 3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [ 3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro- 3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxy norbornane- 5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, and a compound represented by the following formula (6) And particularly 2,3,5-tricarboxycyclopentylacetic acid dianhydride is preferable.

Among aliphatic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides, preferred are butanetetracarboxylic acid dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid Acid dianhydride, 3,3 ', 4,4'-biphenylsulfone tetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8 - naphthalene tetracarboxylic acid dianhydride.

When two or more tetracarboxylic dianhydrides are used in combination, the alicyclic tetracarboxylic dianhydride is preferably at least 50 mol% based on the total tetracarboxylic dianhydride.

Examples of the diamine used in the synthesis of the polyamic acid having the repeating unit represented by the above formula (1a) include aromatic diamines, aliphatic or alicyclic diamines, two primary amino groups in the molecule, A diamine having a nitrogen atom, and a diaminoorganosiloxane.

Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'- Phenyl sulfide, 4,4'-diaminodiphenylsulfone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4 , 4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'- Diaminobiphenyl, 3,3'-ditrifluoromethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) Amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-dia Diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4 - (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hex Bis (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3- Benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7- (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro- , 4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'- Bis [4- (4-tert-butylphenyl) isobutyryl] biphenyl, Bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, -Amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl and the like.

Examples of the aliphatic or alicyclic diamine include 1,1-meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, Diamine, 4,4-diaminoheptamethylene diamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanediyldimethylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenes dimethyldimethylamine, 4,4'-methylenebis (cyclohexylamine), and the like.

Examples of diamines having two primary amino groups in the molecule and nitrogen atoms other than those contained in the primary amino group include 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diamine Diminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4- (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- 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino- Phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9- - ethoxy cyan decyl lactate, 3,8-diamino-6-phenyl phenanthridine, 1,4-diamine Piperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N- (4-aminophenyl) -N, N'-di (4-aminophenyl) -benzidine, N'-dimethyl-benzidine.

Examples of the diaminoorganosiloxane include compounds represented by the following formula (10).

(Wherein R ¹² represents a hydrocarbon group of 1 to 12 carbon atoms, plural R ^{12 s} present may be the same or different, p is an integer of 1 to 3, and q is an integer of 1 to 20)

These diamines may be used alone or in combination of two or more.

Of these diamines, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 2,2- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2- (4-aminophenyl) hexafluoropropane, 4,4'- (p-phenylenediisopropylidene) bisaniline, 4,4 '- (m- phenylenediisopropylidene) (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2, 4-cyclohexanediamine, 4,4'-methylenebis (cyclohexylamine) , 6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacrylidine, 3,6-diaminocarbazole, N- Diaminocarbazole, N-ethyl-3,6-di Aminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) Dimethyl-benzidine is preferred.

In the case where the liquid crystal aligning agent of the present invention is imparted with pre-tilt angularity, a part or all of the diamine used for the synthesis of the polyamic acid having the repeating unit represented by the above formula (1a) is represented by the following formula (Q-1) (Hereinafter referred to as "specific diamine") having a structure represented by the following formula (Q-2).

(Wherein X is a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S- or an arylene group and R ¹³ is an alkyl group having 10 to 20 carbon atoms A monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms)

(Wherein X is a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S- or an arylene group and R ¹⁴ is an alicyclic ring having 4 to 40 carbon atoms Bivalent organic group having a formula skeleton)

Accordingly, a part or all of the groups Q ¹ and Q ² in the formula (1a) can be a group having a structure represented by the above formula (Q-1) or (Q-2), and contributes to the expression of the pretilt angle do.

Examples of the alkyl group having 10 to 20 carbon atoms represented by R ¹³ in the above formula (Q-1) include n-decyl, n-dodecyl, n-pentadecyl, An octadecyl group, and an n-eicosyl group. Examples of the organic group having an alicyclic skeleton having 4 to 40 carbon atoms and represented by R ¹³ in the above formula (Q-1) and R ¹⁴ in the above formula (Q-2) include cyclobutane, cyclopentane , A group having an alicyclic skeleton derived from a cycloalkane such as cyclohexane or cyclodecane; A group having a steroid skeleton such as cholesterol, cholestanol or the like; Norbornene, adamanthan, and the like, and the like. Among them, a group having a steroid skeleton is particularly preferable. The organic group having an alicyclic skeleton may be a halogen atom, preferably a fluorine atom or a group substituted by a fluoroalkyl group, preferably a trifluoromethyl group.

Examples of the fluorine-containing group having 6 to 20 carbon atoms represented by R ¹³ in the above formula (Q-1) include a fluorine-containing group having 6 or more carbon atoms such as an n-hexyl group, an n-octyl group, A straight chain alkyl group; An alicyclic hydrocarbon group having 6 or more carbon atoms such as a cyclohexyl group and a cyclooctyl group; And groups obtained by substituting a part or all of hydrogen atoms in an organic group such as a phenyl group or an aromatic hydrocarbon group having 6 or more carbon atoms such as a biphenyl group with a fluoroalkyl group such as a fluorine atom or a trifluoromethyl group.

X in the formulas (Q-1) and (Q-2) represents a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S - or an arylene group, and examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group and a naphthylene group.

Specific examples of the diamine having the structure represented by the above formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy- , 4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, and compounds represented by the following chemical formulas (11) to (15).

Specific examples of the diamine having the structure represented by the above formula (Q-2) include compounds represented by the following formulas (16) to (18). These specific diamines may be used alone or in combination of two or more.

Among these specific diamines, the compounds represented by the above-mentioned formula (11), (13), (15) or (16) are preferable.

The ratio of the specific diamine to the total amount of diamine varies depending on the size of the pretilt angle to be expressed, but in the case of the TN type or STN type liquid crystal display device, 0 to 5 mol% , It is preferably 5 to 100 mol%.

The ratio of the acid anhydride group of the tetracarboxylic dianhydride to the equivalent amount of the amino group of the diamine to be provided in the synthesis of the polyamic acid having the repeating unit represented by the above formula (1a) is preferably from 0.2 to 2 equivalents, 1.2 equivalent.

The synthesis reaction of the polyamic acid is carried out in an organic solvent under a temperature condition of preferably -20 ° C to 150 ° C, more preferably 0 to 100 ° C, preferably 10 minutes to 50 hours, more preferably 30 minutes 30 hours.

The organic solvent is not particularly limited as long as it can dissolve the polyamic acid to be synthesized. Examples of the organic solvent include 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, Amide solvents such as 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide and 3-hexyloxy-N, N-dimethylpropanamide, dimethylsulfoxide, Nonpolar polar solvents such as butyrolactone, tetramethyl urea, and hexamethylphosphoric triamide; m-cresol, xylenol, phenol, halogenated phenol, and the like.

The amount (?) Of the organic solvent is preferably such that the total amount (?) Of the tetracarboxylic acid dianhydride and the diamine compound is 0.1 to 30% by weight based on the total amount (? +?) Of the reaction solution.

A part of the organic solvent may be substituted with alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc., which are poor solvents of polyamic acid, in a range in which the produced polyamic acid is not precipitated. Specific examples of such a poor solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, But are not limited to, 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, N-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, diethylene glycol diethyl ether, diethyl malonate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, Ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monome 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, isoamyl propionate, isoamyl isobutyrate and diisopentyl ether.

The amount of the poor solvent to be used herein is preferably 50% by weight or less, more preferably 40% by weight or less, in the total solvent.

In this way, a reaction solution obtained by dissolving polyamic acid is obtained. Then, this reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and this precipitate is dried under reduced pressure, or the reaction solution is distilled off under reduced pressure using an evaporator to obtain a polyamic acid. Further, the polyamic acid can be purified by once or several times the step of dissolving the polyamic acid in an organic solvent and then precipitating with a poor solvent, or the step of distilling off under reduced pressure with an evaporator.

The polyimide having a repeating unit represented by the above formula (1b) can be obtained by subjecting a polyamic acid having a repeating unit represented by the above formula (1a) wherein P ¹ is P ² and Q ¹ is Q ² to dehydration ring closure.

In the dehydration ring closure, all of the amic acid structure may be dehydrated and ring-closed to be an imide ring, or only a part of the amic acid structure may be dehydrated and ring-closed to obtain a polymer having an amic acid structure and an imide ring structure.

The dehydration ring closure of the polyamic acid can be carried out by either (i) 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 the solution, Is done.

The reaction temperature in the method of heating the polyamic acid of (i) is preferably 50 to 200 占 폚, more preferably 60 to 170 占 폚. If the reaction temperature is less than 50 ° C, the dehydration ring-closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 ° C, the molecular weight of the resulting imidized polymer may be lowered. The reaction time is preferably 10 minutes to 5 hours, more preferably 30 minutes to 3 hours.

On the other hand, in the case of adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution of the polyamic acid of the above (ii), an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol based on 1 mol of the repeating unit of the polyamic acid although it depends on the desired imidization rate. As the dehydration cyclization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. However, the present invention is not limited thereto. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent used. The imidization rate can be increased as the amount of the dehydrating agent and the dehydrating ring closure agent used increases. On the other hand, examples of the organic solvent used for the dehydration ring-closure reaction include the organic solvents exemplified for use in the synthesis of polyamic acid. The reaction temperature of the dehydration ring-closing reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 30 minutes to 10 hours, more preferably 1 hour to 7 hours.

The polyimide thus obtained can be purified by carrying out the same operation as in the method for purifying polyamic acid in the reaction solution thus obtained.

The polyimide used in the present invention has a proportion of repeating units having an imide ring (hereinafter also referred to as "imidization rate") relative to the total repeating units is 40 mol% or more, preferably 50 mol% or more. By using a polymer having an imidization rate of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal alignment film having a short afterglow erase time can be obtained.

The imidization rate can be obtained by the following method.

[Method of measuring imidization rate of imidized polymer]

The imidized polymer is dried under reduced pressure at room temperature, dissolved in deuterated dimethylsulfoxide, and subjected to ¹ H-NMR measurement at room temperature using tetramethylsilane as a reference material, and can be determined by the following formula (ii).

≪ EMI ID =

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

A ¹ : Peak area (10 ppm) derived from proton of NH group

A ² : Peak area derived from other protons

α: Number of other protons to one proton of the NH group in the polymer precursor (polyamic acid)

The polyamic acid having the repeating unit represented by the above formula (1a) or the polyimide having the repeating unit represented by the above formula (1b) may be a terminal modified type having a controlled molecular weight. By using the polyamic acid or polyimide of the terminal modification type, the effect of the present invention is not impaired and the coating property and the like of the liquid crystal aligning agent can be improved. Such a polyamic acid or polyimide of the terminal modification type can be synthesized by adding an acid anhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system in the synthesis of the polyamic acid. Examples of the acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, and n-hexadecylsuccinic anhydride. . Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-heptadecylamine, n-octadecylamine, n-octadecylamine, n-octadecylamine, n-hexadecylamine, - eicosylamine, and the like. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

The polyamic acid having the repeating unit represented by the above formula (1a) or the polyimide having the repeating unit represented by the above formula (1b) obtained as described above preferably has a viscosity of 20 to 800 mPa · s when it is a 10% solution , And more preferably from 30 to 500 mPa · s.

The solution viscosity (mPa s) of the polymer was measured at 25 캜 using an E-type rotational viscometer for a solution diluted to a predetermined solid concentration using a predetermined solvent.

When the liquid crystal aligning agent of the present invention contains a polyamic acid having a repeating unit represented by the above formula (1a) or a polyimide having a repeating unit represented by the above formula (1b), the ratio of the liquid crystal aligning agent to the liquid crystal aligning agent Is preferably 1,000 parts by weight or less, more preferably 10 to 500 parts by weight based on 1 part by weight of the compound represented by the formula (1). On the other hand, the amount of the second liquid crystal aligning agent is preferably 100 parts by weight or less, more preferably 5 parts by weight or less, and further preferably 5 parts by weight or less, based on 1 part by weight of the polyamic acid obtained by the reaction of the compound represented by the formula (1 ') with the tetracarboxylic dianhydride. To 80 parts by weight.

The liquid crystal aligning agent of the present invention is constituted such that the specific polymer is dissolved and contained in an organic solvent.

The temperature for producing the liquid crystal aligning agent of the present invention is preferably 0 to 200 캜, more preferably 20 to 60 캜.

Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include the solvents exemplified for use in the synthesis reaction of polyamic acid. The poor solvent exemplified as being usable in the synthesis reaction of the polyamic acid can also be suitably selected and used in combination.

The solid concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity and volatility, but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is coated on the substrate surface to form a coating film which becomes a liquid crystal alignment film. When the solid concentration is less than 1 wt%, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film, Is more than 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent increases and the coating property becomes inferior.

A particularly preferable range of the solid concentration is different depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of the spinner method, the range of 1.5 to 4.5 wt% is particularly preferable. In the case of the printing method, it is particularly preferable that the solid concentration is in the range of 3 to 9% by weight and the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink-jet method, it is particularly preferable that the solid concentration is in the range of 1 to 5 wt%, and the solution viscosity is in the range of 3 to 15 mPa · s.

Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include organic solvents such as 1-methyl-2-pyrrolidone,? -Butyrolactone,? -Butyrolactam, N, Methylene-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene Diethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether (ethylene glycol diethyl ether), ethylene glycol n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol- , Diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 3-butoxy N, N-dimethylacetamide, N, N-dimethylpropanamide, 3-methoxy-N, Ether, and the like. These may be used alone or in combination of two or more. Of these, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide and 3-hexyloxy-N, N-dimethylpropanamide show good printability Particularly preferred.

In the liquid crystal aligning agent of the present invention, a functional silane-containing compound, an epoxy compound (provided that the compound represented by the above formula (1) or (1 ') is included in the compound ) May be contained.

Examples of such a functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- 2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3- Ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-tri Methoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl- 3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N- Aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) Methoxy silane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.

Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, Tetraglycidyl-2,4-hexanediol, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl ) Cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl- 3-aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, and the like.

In the first liquid crystal aligning agent, the use ratio of the adhesion improver is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the compound represented by the formula (1). On the other hand, in the second liquid crystal aligning agent, it is preferably 30 parts by weight or less based on 100 parts by weight of the polyamic acid obtained by the reaction between the compound represented by the formula (1 ') and the tetracarboxylic dianhydride, 0.1 to 25 parts by weight.

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

(1) A liquid crystal aligning agent of the present invention is coated on one surface of a substrate provided with a patterned transparent conductive film by an offset printing method, a spin coating method, or an inkjet printing method, and then the coated surface is heated to form a coated film. Examples of the substrate include glass such as float glass and soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and alicyclic polyolefin can be used. As the transparent conductive film to be provided on one surface of the substrate, an ITO film including indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc., a NESA film containing tin oxide (SnO ₂ ) And a method using a photo-etching method or a preliminary mask is used for patterning these transparent conductive films. In the application of the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium-containing compound and the like may be previously applied to the surface of the substrate in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film . After the application of the liquid crystal aligning agent, preheating (prebaking) is preferably carried out for the purpose of preventing the applied alignment agent from being dropped. The prebaking temperature is preferably 30 to 300 占 폚, more preferably 40 to 200 占 폚, particularly preferably 50 to 150 占 폚. Thereafter, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and thermally imidizing the polyamic acid. The firing (post-baking) temperature is preferably 80 to 300 占 폚, and more preferably 120 to 250 占 폚. The liquid crystal aligning agent of the present invention containing the polyamic acid in this manner can be formed into a more imidized coating film by forming a coating film which becomes a liquid crystal alignment film by removing the organic solvent after coating and further heating the film to promote dehydration ring closure . The film thickness of the formed coating film is preferably 0.001 to 1 mu m, more preferably 0.005 to 0.5 mu m.

(2) A rubbing treatment is performed in which the formed film surface is rubbed in a predetermined direction with a roll covered with a cloth made of fibers such as nylon, rayon (registered trademark), or cotton. Accordingly, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention can be applied to a liquid crystal alignment film formed of a liquid crystal alignment film, for example, in Patent Document 2 (Japanese Patent Application Laid-Open No. 6-222366) and Patent Document 3 (Japanese Patent Application Laid-Open No. 6-281937 , A process of changing the pre-tilt angle by partially irradiating ultraviolet rays, or a process of rubbing treatment such as disclosed in Patent Document 4 (Japanese Patent Application Laid-open No. 5-107544) The resist film is partly formed on the surface of the liquid crystal alignment film subjected to the rubbing treatment and the rubbing treatment is performed in a direction different from the rubbing treatment in the previous step. Then, the resist film is removed to change the liquid crystal alignment capability of the liquid crystal alignment film, Can be improved.

(3) Two substrates on which the liquid crystal alignment film was formed as described above were prepared, and two substrates were arranged opposite to each other with a space (cell gap) so that the rubbing direction in each liquid crystal alignment film was orthogonal or antiparallel. The periphery of the substrate is bonded using a sealant, liquid crystal is injected and filled in the cell space defined by the surface of the substrate and the sealant, and the injection hole is sealed to constitute the liquid crystal cell. A polarizing plate is bonded on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell so that the polarizing direction thereof coincides with or orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate, Device is obtained. As the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Of these, a nematic liquid crystal is preferable, and examples thereof include a liquid crystal such as a salt liquid crystal, an agar liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, Biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, quaternary-based liquid crystal and the like can be used. These liquid crystals are also referred to as cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate and cholesteryl carbonate, and those sold under the trade names "C-15" and "CB-15" Chiral agent or the like may be added. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate can also be used. Examples of the polarizing plate bonded to the outer surface of the liquid crystal cell include a polarizing plate in which a polarizing film called an H film in which iodine is absorbed while polyvinyl alcohol is oriented in a stretched state is sandwiched between cellulose acetate protective films or a polarizing plate made of the H film itself.

<Examples>

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the liquid crystal aligning agent and the liquid crystal alignment film obtained therefrom were evaluated according to the following methods.

[Voltage maintenance rate]

A voltage of 5 V was applied to the liquid crystal display element at 60 占 폚 for an application time of 60 microseconds and a span of 167 milliseconds, and the voltage maintenance ratio after 167 milliseconds from the application of the release voltage was measured. VHR-1 manufactured by Toyo Technica Co., Ltd. was used as a measuring device.

[Bake test]

A cell having an ITO electrode as shown in Fig. 1 was prepared. A DC voltage of 6.0 V was applied to the electrode A, and a DC voltage of 0.5 V was applied to the electrode B at room temperature for 24 hours. After the voltage was removed, the firing characteristics were evaluated after a DC voltage of 0.1 to 5.0 V was applied to the poles A and B at a pitch of 0.1 V. &Quot;? &Quot;, "? &Quot;, "? &Quot;, and &quot;? "

[Printing performance evaluation]

A glass substrate of 127 mm (D) x 127 mm (W) x 1.1 mm (H) in which an ITO film was formed on the entire surface of one side was prepared, and a glass substrate with a liquid crystal alignment film coating machine The liquid crystal aligning agent obtained in each of the Examples and Comparative Examples was filtered with a microfiltration filter having a pore size of 0.2 mu m and then coated on the surface of the transparent electrode. The solvent was removed with a hot plate adhesion preliminary drier set at 80 DEG C and baked at 200 DEG C for 60 minutes to form a liquid crystal alignment film on the ITO film-adhered glass substrate. The unevenness of the resulting alignment film was visually evaluated. &Quot; No ", and " x "

Synthesis Example 1

Synthetic Example 1 is a non-patent document [K. Hasegawa, Polymer Journal. Vol. 31, No. 2, 206 (1999)].

6.24 grams (20 mmol) of 4,4'-dibromobiphenyl and 2.16 grams (20 mmol) of paraphenylenediamine were placed in a 300 ml three-necked flask under a nitrogen atmosphere, and 80 ml of toluene was added to dissolve. 0.46 grams (0.5 mmol) of sodium-t-butoxide 5.8 (60 mmol), tris (dibenzylideneacetone) -dipalladium (Pd ₂ (dba) ₃ ), 2,2'-bis (diphenylphosphino) 0.93 grams (1.5 mmol) of 1,1'-binaphthyl (BINAP) was added at room temperature. The reaction solution was reacted by stirring at 100 占 폚 under nitrogen for 16 hours. The reaction solution was returned to room temperature and washed with 2 liters of a mixed solution of 25 wt% ammonia water and methanol (ammonia water / methanol = 1/4 (volume ratio)) using a separating funnel. The organic solvent layer was dehydrated with sodium sulfate and then concentrated using a rotary evaporator. The obtained crude product was purified by silica gel column chromatography to obtain 2.1 g of Compound A-1 represented by the following formula (A-1) .

(Wherein m is a repeating number)

By repeating the same operation, a sufficient amount of Compound A-1 was obtained for use in the following Experimental Examples.

Synthesis Example 2

In a three-necked flask, 10 g of the compound A-1 synthesized in Synthesis Example 1 was dissolved in 50 mL of dimethylsulfoxide (DMSO). An excess amount of an aqueous solution of potassium carbonate was mixed with this solution. After the mixture was cooled in an ice bath, a DMSO solution of epibromohydrin (concentration 1 mol / L) was added dropwise until the excess amount was reached. After completion of dropwise addition, the temperature was returned to room temperature, and stirring was continued for 48 hours. The reaction mixture was filtered, and the filtrate was separated and washed with chloroform / saturated brine. Thereafter, the solvent was distilled off and reprecipitation was carried out with methanol to obtain a mixture A-2 of a compound represented by the following formula.

(Wherein m 'and m "are each a repetitive number)

Polyimide Synthesis Example 1

112 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic acid dianhydride and 1,3-dihydroxy-8-methyl-5- 157 g (0.50 mole) of p-phenylenediamine, 96 g (0.89 mole) of p-phenylenediamine as a diamine compound 25 g (0.10 mole) of 3,3 '- (tetramethyldisiloxane-1,3-diyl) bis (propylamine) and 13 g (0.020 mole) of 3,6-bis (4-aminobenzoyloxy) cholestane Mol) and 8.1 g (0.030 mol) of n-octadecylamine as a monoamine were dissolved in 960 g of N-methyl-2-pyrrolidone and reacted at 60 DEG C for 6 hours. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity of the solution with a solid concentration of 10%, which was 60 mPa · S. Then, 2700 g of N-methyl-2-pyrrolidone was added to the resulting polyamic acid solution, and 396 g of pyridine and 409 g of acetic anhydride were added, followed by dehydration cyclization at 110 DEG C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a solvent with a new? -Butyrolactone (pyridine used in the imidation reaction and acetic anhydride used in the imidization reaction were removed out of the system by this operation), a solid concentration of 15 wt%, a solid concentration of 6.0 About 2000 g of an imidation polymer (referred to as "polyimide (I-1)") having a solution viscosity of 16 mPa · S and an imidization rate of about 95% in a solution of γ-butyrolactone was obtained.

Polyimide Synthesis Example 2

224 g (1.0 mole) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic acid dianhydride, 108 g (1.0 mole) of p-phenylenediamine as a diamine compound, (0.015 mol) of diaminobenzoate were dissolved in 3039 g of N-methyl-2-pyrrolidone and reacted at 60 占 폚 for 6 hours to obtain a polyamic acid solution having a solution viscosity of about 260 mPa 占 퐏. Then, 2700 g of N-methyl-2-pyrrolidone was added to the resulting polyamic acid solution, and 396 g of pyridine and 306 g of acetic anhydride were added, followed by dehydration cyclization at 110 DEG C for 4 hours. After the imidization reaction, the solvent in the system was replaced with a solvent of a new? -Butyrolactone (by this operation, pyridine and anhydrous acetic acid used in the imidization reaction were removed out of the system), a solids concentration of about 9.0 wt%, a solids concentration of 5.0 About 3000 g of an imidation polymer (referred to as "imidation polymer (I-2)") having a solution viscosity of 72 mPa · S and an imidization rate of about 51% in a solution of γ-butyrolactone was obtained.

Polyamic acid Synthesis Example 1

196 g (1.0 mole) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as a tetracarboxylic acid dianhydride, 2,2'-dimethyl-4,4'-diaminobiphenyl 212 (1.0 mol) was dissolved in 370 g of N-methyl-2-pyrrolidone and 3300 g of? -butyrolactone and reacted at 40 占 폚 for 3 hours. Polyamic acid having a viscosity of 160 mPa 占 이를 (Na-1) ") solution.

Polyamic acid Synthesis Example 2

As the tetracarboxylic acid dianhydride, 95 g (0.50 mole) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 109 g (0.50 mole) of pyromellitic dianhydride, 2,7-dia 196 g (1.0 mole) of the aminofluorene was dissolved in 230 g of N-methyl-2-pyrrolidone and 2060 g of? -Butyrolactone, and the mixture was reacted at 40 占 폚 for 3 hours. 1350 g of? -Butyrolactone To obtain about 3600 g of a polyamic acid solution (hereinafter referred to as "polyamic acid (Na-2)") having a solution viscosity of 125 mPa · S at a solid concentration of 10%.

Example 1

Polyimide The polyamic acid (I-1) obtained in Synthesis Example 1 and the polyamic acid (I-1) obtained in Polyamic acid Synthesis Example 1 were added to γ-butyrolactone (polyimide) so that the ratio of polyimide to polyamic acid was 20:80 N, N ', N', N'-tetraglycidyl-4,4'-di (tert-butyldimethylsilyl) amide was dissolved in a mixed solvent of N-methyl-2-pyrrolidone / butyl cellosolve (weight ratio 71/17/12) 2 parts by weight of minodiphenylmethane was added to 100 parts by weight of the polymer, and 10 parts by weight of Compound A-1 obtained in Synthesis Example 1 as the compound represented by the above Formula 1 was added to 100 parts by weight of the polymer to prepare a solution having a solid content concentration of 3.5% A solution of 6.0% by weight was prepared. Each solution was thoroughly stirred, and then filtered using a filter having a pore size of 1 탆 to prepare a liquid crystal aligning agent of the present invention.

A solution having a solid content concentration of 3.5% in the above liquid crystal aligning agent was applied on a transparent conductive film made of an ITO film provided on one side of a glass substrate having a thickness of 1 mm using a spinner (rotation speed: 2500 rpm, coating time: Minute), and dried at 200 DEG C for 1 hour to form a film having a dry film thickness of 0.08 mu m. This film was subjected to a rubbing treatment with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a piercing length of 0.4 mm. The liquid crystal alignment film coated substrate was ultrasonically cleaned in ultrapure water for 1 minute and dried in a 100 ° C clean oven for 10 minutes. Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 占 퐉 was applied to each of outer edges of the pair of transparent electrode / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, leaving a liquid crystal injection hole, So that the surfaces were opposed to each other, and then pressed and cured. Subsequently, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was charged between the substrates from the liquid crystal injection port, and then the liquid crystal injection hole was sealed with an acrylic light-curing adhesive to prepare a liquid crystal display device. Evaluation of the voltage holding ratio and baking evaluation of the obtained liquid crystal display element were carried out according to the method described above.

Further, the printability evaluation was carried out according to the above-described method using a solution having a solid content concentration of 6.0% by weight.

Examples 2 to 4

The same procedures as in Example 1 were carried out except that the compounds shown in the above formula (1), polyimide and polyamic acid shown in the following Table 1 were used.

Example 5

Polyimide The polyimide (? -2) obtained in Synthesis Example 2 was dissolved in a mixed solvent of N-methyl-2-pyrrolidone / butyl cellosolve (weight ratio 50/50) N'-tetraglycidyl-4,4'-diaminodiphenylmethane was added to 100 parts by weight of the polymer 100, and the compound A-1 obtained in the above Synthesis Example 1 as the compound represented by the above-mentioned Formula 1 was dissolved in 100 parts by weight of the polymer 100 To give a solution having a solid concentration of 3.5% by weight and a solution containing 6.0% by weight. Each solution was thoroughly stirred, and then filtered using a filter having a pore size of 1 탆 to prepare a liquid crystal aligning agent of the present invention. A method for producing a liquid crystal display element, a method for evaluating a liquid crystal display element, and a method for evaluating orientation agent printability were carried out in the same manner as in Example 1.

Example 6

The procedure of Example 5 was repeated except that the compound shown in Table 1 was used as the compound represented by the above formula (1).

Comparative Examples 1 to 2

Polyimide and polyamic acid were prepared in the same manner as in Example 1 except that the compounds shown in Table 1 were used and the compound represented by Formula 1 was not added.

Comparative Example 3

The procedure of Example 5 was followed except that the compound of Formula 1 was not added.

Comparative Examples 4 to 5

로 표시되는 화합물(이하, "화합물 X"라 함)을 사 용한 것 외에는 실시예 1과 동일한 절차로 행하였다. 한편, 화합물 X는 특허 문헌 5(일본 특허 공개 제2000-44683호 공보)에 기재된 방법에 따라 합성하였다. The polyimide and polyamic acid used in Example 1 were the same as those shown in Table 1 except that the compound represented by the following formula

(Hereinafter referred to as "compound X") was used in place of the compound (X). Compound X was synthesized according to the method described in Patent Document 5 (Japanese Patent Laid-Open No. 2000-44683).

Comparative Example 6

The procedure of Example 5 was repeated except that the compound X was used instead of the compound represented by the formula 1.

Comparative Examples 7 to 8

로 표시되는 반복 단위를 갖는 중합체(이하, "중합체 Y"라 함)를 사용한 것 외에는 실시예 1과 동일한 절차로 행하였다. 중합체 Y는 특허 문헌 6(국제 공개 제2002/100949호 공보)에 기재된 방법에 따라 합성하고, 그의 수 평균 분자량 Mn은 15,000이고, 중량 평균 분자량 Mw는 30,000이었다.In the same manner as in Example 1 except that the polyimide and polyamic acid shown in Table 1 were used, and in place of the compound represented by Formula 1,

(Hereinafter referred to as "polymer Y") having a repeating unit represented by the following formula (1) was used. Polymer Y was synthesized according to the method described in Patent Document 6 (International Publication No. 2002/100949), and its number average molecular weight Mn was 15,000 and its weight average molecular weight Mw was 30,000.

Comparative Example 9

The procedure of Example 5 was repeated except that Polymer Y was used instead of the compound represented by Formula 1 above.

All of the above results are shown in Table 1. On the other hand, in Table 1, "-" indicates that no component corresponding to the column is used. Also, "> 99%" of the voltage holding ratio indicates that the measured value exceeds 99%.

Fig. 1 is a schematic view of a cell prepared for a bake test in Examples and Comparative Examples. Fig.

Claims (9)

A liquid crystal aligning agent characterized by containing a compound represented by the following formula (1). &Lt; Formula 1 >

(Wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, and R ⁴ to R ⁷ each independently represent a monovalent aliphatic group having a hydrogen atom, a monovalent aromatic group, a monovalent aliphatic group or an epoxy group A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom, a monovalent aliphatic group or an epoxy group, and n is an integer of 1 to 100) The liquid crystal alignment film of claim 1, wherein R ¹ to R ³ are independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and A ¹ and A ² are hydrogen atoms, My. The positive resist composition according to Claim 1, wherein R ¹ to R ³ in the formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, and R ⁴ to R ⁷ are monovalent And A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom or an epoxy group. The compound according to Claim 1, wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, R ⁴ and R ⁶ are monovalent aromatic groups , R ⁵ and R ⁷ are each a hydrogen atom or a monovalent aliphatic group, and A ¹ and A ² are each independently a hydrogen atom or a monovalent aliphatic group. The compound according to Claim 1, wherein R ¹ to R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 6 carbon atoms, R ⁴ and R ⁶ are monovalent aromatic groups , R ⁵ and R ⁷ are each a monovalent aliphatic group having a hydrogen atom or an epoxy group, and A ¹ and A ² are each independently a monovalent aliphatic group having a hydrogen atom or an epoxy group. A liquid crystal aligning agent characterized by containing a polyamic acid obtained by reacting a compound represented by the following formula (1 ') with a tetracarboxylic dianhydride. &Lt; Formula (1) &gt;

(Wherein, R ¹ to R ³ are each independently a hydrogen atom, an alkyl group or an alkoxyl group, A ¹ and A ² are each independently aliphatic monovalent having a hydrogen atom, a monovalent aliphatic group or an epoxy group, n is 1 to 100) The polyimide resin composition according to any one of claims 1 to 6, further comprising a polyamic acid having a repeating unit represented by the following formula (1a) and a polyimide having a repeating unit represented by the following formula Or more of the liquid crystal aligning agent. <Formula 1a>

(Wherein P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group) &Lt; EMI ID =

(Wherein P ² is a tetravalent organic group and Q ² is a divalent organic group) The polyimide resin composition according to claim 7, which comprises a polyamic acid having a repeating unit represented by the formula (1a) and a polyimide having a repeating unit represented by the formula (1b), wherein the polyamic acid and the polyimide are 2,3,5- Wherein the liquid crystal aligning agent is synthesized from tetracarboxylic dianhydride and diamine containing cyclopentyl acetic acid dianhydride. A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal alignment agent according to any one of claims 1 to 6.

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