JP5088563B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal alignment agent used for forming a liquid crystal alignment film of a liquid crystal display element, and a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent that provides a liquid crystal alignment film having excellent vertical alignment properties, good electrical characteristics, and good printability, and a liquid crystal display element excellent in display characteristics.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate provided with a transparent conductive film such as ITO (indium oxide-tin oxide) to form a substrate for a liquid crystal display element. Two of them are placed facing each other and a nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap to form a sandwich cell, where the major axis of the liquid crystal molecules is directed from one substrate to the other. There is known a TN liquid crystal display element having a so-called TN (twisted nematic) liquid crystal cell that is continuously twisted by 90 °. Further, STN (Super Twisted Nematic) type liquid crystal display elements have been developed that have higher contrast than TN type liquid crystal display elements and have less viewing angle dependency. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 ° between substrates. The birefringence effect generated by the above is utilized.
In addition to these, a vertical alignment type liquid crystal display element called an 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 has been proposed (Patent Document 1 and Non-Patent Document 1). (See Patent Document 1). The MVA liquid crystal display element is excellent in terms of manufacturing process, such as excellent viewing angle, contrast, and the like, and does not need to be rubbed in forming the liquid crystal alignment film.
The liquid crystal alignment film suitable for the TN, STN, and MVA methods is required to have electrical characteristics such as a short afterimage erasing time of the liquid crystal display element. Furthermore, the alignment agent used for forming these liquid crystal alignment films is required to have excellent printability in offset printing.
Japanese Patent Laid-Open No. 11-258605 JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 “Liquid Crystal”, Vol. 3 (No. 2), p117 (1999)

The present invention has been made based on the above circumstances, and its object is to provide a liquid crystal alignment film that has excellent vertical alignment, maintains a voltage holding ratio, and reduces accumulated charges, and is further excellent. Another object of the present invention is to provide a liquid crystal aligning agent having printability and a liquid crystal display element using the same.
Still 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 firstly
The following formula (I-1)

(In Formula (I-1), P ¹ is a tetravalent organic group, and Q ¹ is the following Formulas (II-1) to (II-4)

(In formulas (II-1) to (II-4), R ^{1 to} R ⁴ are each a linear, branched or cyclic alkyl group having 1 to 11 carbon atoms, or a linear or branched group having 4 to 11 carbon atoms. A branched or cyclic alkenyl group, wherein ¹ to 7 hydrogen atoms of R ^{1 to} R ⁴ may be substituted with fluorine atoms, and A ¹ and A ² are each independently a hydrogen atom or methyl Group.)
It is a bivalent group represented by either. )
It is achieved by a liquid crystal aligning agent containing a polymer having a structural unit represented by: The liquid crystal aligning agent of the present invention is preferably further represented by the following formula (I-2)

(In Formula (I-2), P ² is a tetravalent organic group, and Q ² is a divalent organic group.)
And a polymer having no structural unit represented by the above formula (I-1).
Secondly, the above object of the present invention is achieved by a liquid crystal display device comprising a liquid crystal alignment film obtained from any one of the above liquid crystal aligning agents.

The liquid crystal aligning agent of this invention is called a polymer (henceforth "specific polymer") which has a structural unit (henceforth "structural unit (I-1)") represented by the said formula (I-1). ).
<Specific polymer>
The tetravalent organic group of P ^{1 in} the above formula (I-1) is a tetravalent organic group having an alicyclic structure, or a tetravalent organic group obtained by removing four hydrogen atoms from an aliphatic compound. Groups, tetravalent organic groups having an aromatic ring, and the like, at least a part of which is represented by the following formulas (III-1) to (III-4):

And at least one selected from tetravalent organic groups represented by each of the above formulas (III-1) and (III-2).
Q ¹ in the above formula (I-1) is a divalent group represented by any ^one of the above formulas (II-1) to (II-4).
In the divalent groups represented by the above formulas (II-1) to (II-4), examples of the linear alkyl group having 1 to 11 carbon atoms represented by R ^{1 to} R ⁴ include n-hexyl. Group, n-octyl group, n-decyl group and the like;
Examples of the branched alkyl group include 1-methylhexyl group, 1-ethylhexyl group, 2-methylhexyl group, 2-ethylhexyl group, 1-ethyloctyl group, 2-ethyloctyl group, 3-ethyloctyl group, 1 2-dimethylhexyl group, 1,2-diethylhexyl group, 1,2-dimethyloctyl group, 1-methyldecyl group, 2-methyldecyl group, etc .;
Examples of the cyclic alkyl group include groups obtained by removing one hydrogen atom from a cyclic alkane such as cyclobutane, cyclopentane, cyclohexane, cyclodecane, norbornene, bicyclooctane, bicycloundecane, and adamantane.
As the linear, branched or cyclic alkenyl group having 4 to 11 carbon atoms represented by R ^{1 to} R ⁴ , one or more of the carbon-carbon bonds of the alkyl group exemplified above are doubled. The group which became a coupling | bonding can be mentioned.
The bonds having two divalent groups represented by the above formulas (II-1) to (II-4) are preferably in the 3rd and 5th positions with respect to the heterocyclic ring containing a nitrogen atom, respectively. .
The specific polymer may have other structural units other than the structural unit (I-1) as long as the effects of the present invention are not impaired. Here, the other structural unit is a structural unit in which Q ¹ is a divalent organic group other than the above formulas (II-1) to (II-4) in the general formula (I-1). The proportion of the structural unit (I-1) in all structural units of the specific polymer is preferably 10 mol% or more, more preferably 20 mol% or more.
Such a specific polymer is represented by the following formula (III ′)

(In the above formula, P ¹ has the same meaning as in the above formula (I-1).)
A tetracarboxylic dianhydride represented by the following formulas (II-1 ′) to (II-4 ′):

(In the above formulas (II-1 ′) to (II-4 ′), R ^{1 to} R ⁴ and A ¹ and A ² have the same meanings as in the above formulas (II-1) to (II-4). .)
A part of an amic acid unit possessed by a polyamic acid (hereinafter also referred to as “specific polyamic acid”) obtained by a reaction with a diamine containing at least one selected from the group consisting of compounds represented by It is obtained by imidizing the whole. ^{P 1} in the above formula (I-1) is' derived from ^{P 1} in, ^{Q 2} is the formula (II-1 above formula (III) 'having a) Each compound in any of ~ (II-4') It is derived from the structure obtained by removing each of the two amino groups.
Hereinafter, the tetracarboxylic dianhydride and diamine that are preferably used for synthesizing the specific polymer contained in the liquid crystal aligning agent of the present invention will be described.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride used for the synthesis of the specific polymer is a compound represented by the above formula (III ′), for example, an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride. And aromatic tetracarboxylic dianhydrides.
Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride.
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2, 3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic 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, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 2,3,5-tri Carboxycyclopentyl acetic acid dianhydride, 1,2,4-tricarboxycyclopentyl acetic acid dianhydride, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane-3,4,8,9-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride,

1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-7-ethyl-5 (tetrahydro 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene -1,2-dicarboxylic anhydride, bicyclo [2.2 2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3'- (Tetrahydrofuran-2 ′, 5′-dione), 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 the following formula (a) or (b)

(In formulas (a) and (b), R ⁵ and R ⁷ each represent a divalent organic group having an aromatic ring, R ⁶ and R ⁸ each represent a hydrogen atom or an alkyl group, R ⁶ and R ^{8 present} may be the same or different.)
The compound etc. which are represented by these can be mentioned.
Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenylsulfone. Tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl Ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1, 2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) Zife Rusulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (Triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol bis (anhydro trimellitate), propylene glycol bis (anhydro trimellitate) ), 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (1) to (4)

The compound etc. which are represented by these can be mentioned.
These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
Among these tetracarboxylic dianhydrides, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4 5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene 1,2-dicarboxylic anhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1 , 3-dione, 1,3,3a, 4,5,9b-hexahydro 5,8-Dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2,2,2] -oct-7 -Ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5′-dione), pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, Among the compounds represented by 1,4,5,8-naphthalenetetracarboxylic dianhydride and the above formula (a), the following formulas (5) to (7)

Or a compound represented by the above formula (b):

Is preferable from the viewpoint that good liquid crystal orientation can be expressed, and more preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2 , 3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-5,8-dimethyl-5 (teto Hydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6 -Spiro-3 '-(tetrahydrofuran-2', 5'-dione), pyromellitic dianhydride or a compound represented by the above formula (5), more preferably the following formula (III-1 ') (III-4 ')

2,3,5-tricarboxycyclopentylacetic acid dianhydride represented by: 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride or pyromellitic dianhydride,
In particular, a compound represented by the above formula (III-1 ′) or (III-2 ′) is preferable.
The tetracarboxylic dianhydride used for synthesizing the specific polymer contained in the liquid crystal aligning agent of the present invention is composed of compounds represented by the above formulas (III-1 ′) to (III-4 ′). It is preferable to include at least one selected from the group, and the use ratio thereof is more preferably 20 mol% or more, further preferably 40 mol% or more, based on the total tetracarboxylic dianhydride. In particular, the tetracarboxylic dianhydride preferably contains at least one selected from the group consisting of compounds represented by the above formula (III-1 ′) or (III-2 ′). The use ratio is preferably 60 mol% or more, more preferably 80 mol% or more, based on the total tetracarboxylic dianhydride.

<Diamine>
A preferred diamine used for synthesizing the specific polymer of the present invention is at least one selected from the group consisting of compounds represented by each of the above formulas (II-1 ′) to (II-4 ′) ( Hereinafter referred to as “specific diamine”).
As the diamine used in the synthesis of the specific polymer, only the above-mentioned specific diamine may be used, and by using the specific diamine in combination with another diamine, the specific polymer can be converted to other than the structural unit (I-1). May also include other structural units.
Examples of such other diamines include aliphatic or alicyclic diamines, diamines having two primary amino groups in the molecule and nitrogen atoms other than the primary amino groups, diaminoorganosiloxanes, and aromatic diamines. Can do.

Examples of the aliphatic or alicyclic diamine include 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylene. Diamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenediethylenediamine, tricyclo [6.2.1 .0 ^2,7] - undecylenate range methyl diamine, 4,4'-methylenebis (cyclohexylamine) and the like;
Examples of the diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group include 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2, 4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3,5-triazine, , 6-Diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino- 1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4 -Aminophenyl) phenylamine and the like;
Examples of the diaminoorganosiloxane include the following formula (9):

(In Formula (9), a plurality of R ⁹ are each independently a hydrocarbon group having 1 to 12 carbon atoms, p is an integer of 1 to 3, and q is an integer of 1 to 20).
A compound represented by:
Examples of the aromatic diamine include p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2, 5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4, , 4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl- 4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3 -Trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) Phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane,

2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis ( 3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis ( 4-aminophenyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro- 4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) Suaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino- 2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 3,6-diaminocarbazole, N-methyl-3 , 6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, the following formula (Q-1) or (Q-2)

(In formulas (Q-1) and (Q-2), each X independently represents a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, — S—, an arylene group, and R ¹⁰ 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 group having a fluorine atom having 6 to 20 carbon atoms. R ¹¹ is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms.)
And the like can be mentioned respectively.
In the formula (Q-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ¹⁰ include an n-decyl group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, and an n-octadecyl group. Group, n-eicosyl group and the like.
Examples of the monovalent or divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ¹⁰ in the formula (Q-1) and R ¹¹ in the formula (Q-2) include, for example, cyclobutane. , Cyclopentane, cyclohexane, cyclodecane and other cycloalkane-derived alicyclic skeleton groups; cholesterol, cholestanol and other steroid skeleton groups; norbornene, adamantane and other bridged alicyclic skeleton groups It is done. Among these, a group having a steroid skeleton is particularly preferable. In the organic group having the alicyclic skeleton, some or all of the hydrogen atoms may be substituted with a halogen atom, preferably a fluorine atom, a fluoroalkyl group, preferably a trifluoromethyl group.
Examples of the group having 6 to 20 carbon atoms represented by R ¹⁰ in the formula (Q-1) include 6 to 20 carbon atoms such as an n-hexyl group, an n-octyl group, and an n-decyl group. A linear alkyl group of: an alicyclic hydrocarbon group having 6 to 20 carbon atoms such as a cyclohexyl group or a cyclooctyl group; an organic group such as an aromatic hydrocarbon group having 6 to 20 carbon atoms such as a phenyl group or a biphenyl group And a group in which part or all of the hydrogen atoms are substituted with a fluoroalkyl group such as a fluorine atom or a trifluoromethyl group.
X in the above formulas (Q-1) and (Q-2) is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group. Examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group, and a naphthylene group. X is particularly preferably a group represented by -O-, -COO- or -OCO-.

  Preferable specific examples of the diamine represented by the formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2, 4-diaminobenzene or the following formulas (10) to (19)

The compound represented by these can be mentioned. Preferable specific examples of the diamine represented by the above formula (Q-2) include the following formulas (20) to (22).

The compound represented by these can be mentioned.
Of these, particularly preferred are compounds represented by the above formula (10), (11), (16), (17) or (20).
When a specific diamine and another diamine are used in combination in the synthesis of the specific polymer, the use ratio of the specific diamine is preferably 10 mol% or more, more preferably 20 mol% or more with respect to the total diamine.

<Synthesis of specific polymer>
Next, a preferred method for synthesizing the specific polymer will be described.
The specific polymer is an amic acid structure of a specific polyamic acid (hereinafter referred to as “specific polyamic acid”) obtained by reacting the tetracarboxylic dianhydride as described above with a diamine containing the specific diamine. It can be synthesized by dehydrating and ring-closing part or all of the above.
Hereinafter, a method for synthesizing a specific polyamic acid will be described first, and then a dehydration cyclization reaction of the specific polyamic acid will be described.

<Synthesis of specific polyamic acid>
The specific polyamic acid is the above tetracarboxylic dianhydride and a diamine containing the specific diamine, preferably in an organic solvent, preferably at a temperature of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C. , Preferably, it can synthesize | combine by making it react for 1 to 30 hours.
The proportion of tetracarboxylic dianhydride and diamine used in the synthesis reaction of the specific polyamic acid is such that the acid anhydride group of tetracarboxylic dianhydride is 0.5 to 2 with respect to 1 equivalent of amino group of diamine. The ratio which becomes an equivalent is preferable, More preferably, it is a ratio which becomes 0.7-1.2 equivalent.
Here, the organic solvent is not particularly limited as long as it can dissolve the specific polyamic acid to be synthesized. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3 Amido solvents such as -butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethyl Examples include aprotic polar solvents such as urea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. Further, the amount (α) of the organic solvent used is such that the ratio (monomer concentration) of the total amount (β) of tetracarboxylic dianhydride and diamine compound to the total amount (α + β) of the reaction solution is 0.1 to 30% by weight. Such an amount is preferred.

As the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are poor solvents for the specific polyamic acid, can be used in combination as long as the generated specific polyamic acid does not precipitate. Specific examples of the poor solvent include, for example, methanol, ethanol, isopropanol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol. Monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, Diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether Ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1, Examples include 2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, and diisopentyl ether. Can.
When the organic solvent and the poor solvent are used in combination, the use ratio of the poor solvent is preferably 50% by weight or less, more preferably 20% by weight or less, and further 10% by weight with respect to the total amount of the organic solvent and the poor solvent. % Or less is preferable.
As described above, a reaction solution obtained by dissolving the specific polyamic acid is obtained. The reaction solution is poured into a large amount of a poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure, or the specific polyamic acid can be isolated by distilling the reaction solution under reduced pressure with an evaporator. it can. Further, the specific polyamic acid can be purified by performing the step of dissolving the specific polyamic acid again in an organic solvent and then precipitating with a poor solvent, or the step of evaporating under reduced pressure with an evaporator once or several times. .
The specific polyamic acid thus obtained has the following formula (I-3)

(In formula (I-3), P ¹ and Q ¹ each have the same meaning as in formula (I-1) above.)
It has the structural unit represented by these.

<Dehydration ring closure reaction of specific polyamic acid>
The specific polymer contained in the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing some or all of the amic acid structural units of the specific polyamic acid.
By the dehydration ring-closing reaction of the specific polyamic acid, the amic acid structure is converted into an imide structure, and a specific polymer is obtained. In the specific polymer, the ratio (a / (a + b)) of the number of imide structural units to the total of the number a of imide structural units and the number b of amic acid structural units (a / (a + b)), that is, the imidation ratio of the specific polymer is preferably 50. It is -100%, More preferably, it is 70-100%. The imidation ratio of the polymer can be determined from ¹ H-NMR of the polymer by the following mathematical formula (1).

Imidation ratio (%) = (1−A1 / A2 × α) × 100 (1)

(In the formula (1), A1 is a peak area in the vicinity of 10 ppm chemical shift derived from the proton of the NH group, A2 is a peak area in the vicinity of 7-8 ppm chemical shift derived from the aromatic proton, and α is imidization. (This is the ratio of the number of aromatic protons to one proton of the NH group in the polyamic acid before the reaction.)

The dehydration cyclization reaction of the specific polyamic acid can be carried out by (i) a method of heating the specific polyamic acid or (ii) dissolving the specific polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating as necessary. It is done by the method to do.
The reaction temperature in the method (i) of heating the specific polyamic acid is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. If the reaction temperature is less than 50 ° C., the dehydration ring closure reaction does not proceed sufficiently, and if the reaction temperature exceeds 200 ° C., the molecular weight of the specific polymer subjected to dehydration ring closure may decrease. The reaction time is preferably 1 to 120 hours, more preferably 2 to 30 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution of the specific polyamic acid, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used. be able to. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of repeating units of a specific polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of the specific polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

  The specific polymer obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the specific polymer obtained. On the other hand, in the above method (ii), a reaction solution containing a specific polymer is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the specific polymer is isolated. In addition, the liquid crystal aligning agent may be used for preparation, or the isolated specific polymer may be purified and then used for preparation of the liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The isolation and purification of the specific polymer can be performed by performing the same operations as described above as the isolation and purification methods of the specific polyamic acid, respectively.

<End-modified polymer>
The specific polymer used in the present invention may be a terminal-modified type having a controlled molecular weight. By using a 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 polymer can be synthesized by adding a molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing a specific polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n -Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine . Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The molecular weight regulator is preferably used in an amount of 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used in the synthesis of the specific polyamic acid. .

<Solution viscosity of specific polymer>
The specific polymer obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, and has a solution viscosity of 30 to 500 mPa · s, when a 10% by weight solution is obtained. More preferably.
The solution viscosity (mPa · s) of the specific polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using an E-type rotational viscometer.

<Other ingredients>
Although the liquid crystal aligning agent of this invention contains the said specific polymer as an essential component, it can further contain another component arbitrarily. Examples of such other additives include polymers other than the specific polymer, functional silane compounds, and epoxy compounds.
<Other polymers>
The liquid crystal aligning agent of the present invention may further contain a polymer other than the specific polymer (hereinafter referred to as “other polymer”) in addition to the specific polymer. The other polymer is preferably a polymer having a structural unit represented by the above formula (I-2) and not having a structural unit represented by the above formula (I-1).
Preferred P ² in the above formula (I-2) is the same as that of P ^{1 in} the above formula (I-1), and Q ² is represented by the above formulas (II-1) to (II-4). It is preferably other than the structural unit.
Such other preferred polymer is synthesized in the same manner as the synthesis of the specific polyamic acid, using the tetracarboxylic dianhydride and the other diamine described above as those that can be used to synthesize the specific polymer. can do.
The tetracarboxylic dianhydride used to synthesize other polymers is preferably an aromatic tetracarboxylic dianhydride or an alicyclic tetracarboxylic dianhydride, particularly pyromellitic dianhydride or 1,2,3,4-cyclobutanetetracarboxylic dianhydride can be preferably used. As a diamine used for synthesizing another polymer, an aromatic diamine is preferable, and 4,4-diaminodiphenylmethane can be particularly preferably used.
The amount of the other polymer used is preferably 90 parts by weight or less, more preferably 20 to 80 parts by weight based on the total of all the polymers (specific polymers and all other polymers; the same shall apply hereinafter). Parts by weight.

<Functional silane compound>
The said functional silane compound can be added in order to improve the adhesiveness with respect to the substrate surface of the liquid crystal aligning film obtained. Specific examples of such functional silane compounds include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl -1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diaza Nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.
The amount of the functional silane compound used is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less, based on 100 parts by weight of the total polymer.

<Epoxy compound>
Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diame Diphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, N, N, -diglycidyl-benzylamine, N, N-diglycidyl-amino And methylcyclohexane.
The amount of the epoxy compound used 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 total polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is prepared as a solution state in which the specific polymer and other components optionally added are preferably dissolved in an organic solvent.
As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a specific polyamic acid can be mentioned. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of specific polyamic acid can also be selected suitably, and can be used together.
Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy -4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl Ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol di Methyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamylpropionate, isoamyl isobutyrate, diisopentyl ether, 3-butoxy-N, N- List dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, diethyl carbitol, ethyl carbitol acetate, butyl carbitol, triethylene glycol dimethyl ether, etc. Can do. These can be used alone or in admixture of two or more. A particularly preferable solvent composition is a composition obtained by combining the above-mentioned solvents, wherein no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 25 to 40 mN / m. It is.
The solid content concentration (the value obtained by dividing the total weight of components other than the solvent in the liquid crystal aligning agent by the total weight of the liquid crystal aligning agent) in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like. Preferably it is the range of 1-10 weight%.
The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention obtained as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3).
(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 an appropriate application method such as an offset printing method, a spin coating method, or an ink jet printing method, and then applied. A coating film is formed by heating the surface. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance when forming the transparent conductive film is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound or the like is applied in advance to the surface of the substrate. It may be left. The heating temperature after applying the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The heating time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. In addition, although the liquid crystal aligning agent of this invention can form the coating film used as a liquid crystal aligning film by removing an organic solvent after the application | coating, the liquid crystal aligning agent of this invention is a polymer which has an amic acid structure. In the case where it is contained, the film can be further heated to cause dehydration and ring closure of the amic acid structure to proceed to form a more imidized coating film.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) Next, a rubbing process is performed in which the coating surface formed as described above is rubbed in a certain direction with a roll around which a cloth made of fibers such as nylon, rayon, and cotton is wound. Thereby, the orientation ability of liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation film. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is disclosed in, for example, Patent Document 2 (Japanese Patent Laid-Open No. 6-222366) and Patent Document 3 (Japanese Patent Laid-Open No. 6-281937). A resist film is formed on the surface of the liquid crystal alignment film that has been subjected to a treatment that changes the pretilt angle by partially irradiating ultraviolet rays, or a rubbing treatment as disclosed in Patent Document 4 (JP-A-5-107544). Is partially formed, and after the rubbing treatment is performed in a direction different from the previous rubbing treatment, the resist film is removed, and a treatment for changing the liquid crystal orientation ability of the liquid crystal orientation film is performed. It is possible to improve the visibility characteristics.

(3) Two substrates on which a liquid crystal alignment film is formed as described in the above (1) or (2) are produced, and two sheets are rubbed so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. The substrates are arranged facing each other through a gap (cell gap), the peripheral portions of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, The injection hole is sealed to constitute a liquid crystal cell. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together. Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited to these Examples.
The liquid crystal aligning agents prepared in the following examples and comparative examples were evaluated according to the following methods.
[Printability evaluation]
Using the liquid crystal aligning agent having a solid content concentration of 5% by weight prepared in each example or comparative example, using a printing machine for applying a liquid crystal alignment film (manufactured by Nissha Printing Co., Ltd., model “Angstromer S-40L”). Then, coating was carried out continuously for 10 minutes at a constant liquid amount on a transparent conductive film made of an ITO film provided on one side of a 1 mm thick glass substrate. After continuous application for 10 minutes, a film having a film thickness of about 0.06 μm was formed by heating at 200 ° C. for 60 minutes. With respect to this coating, the presence or absence of coating unevenness was visually observed, the level at which coating unevenness was scarcely observed was level 1, the level at which coating unevenness was significantly observed was level 5, and the printability was evaluated in 5 stages.

[Evaluation of voltage holding ratio]
On a glass substrate ITO electrode having a patterned ITO electrode with a thickness of about 1 mm formed on one side, a liquid crystal alignment agent having a solid content concentration of 3.5% by weight prepared in each example or comparative example was used using a spin coater. And heated at 200 ° C. for 60 minutes to prepare a pair (two) of glass substrates having a coating film with a film thickness of about 0.06 μm.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edges of the pair of transparent electrodes / transparent substrate having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, leaving a liquid crystal injection port. After that, the liquid crystal alignment film surfaces were overlapped so as to face each other and pressed to cure the adhesive. Next, a nematic liquid crystal (negative type, MLC-6608, MLC-6608) is filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and both sides outside the substrate are sealed. A liquid crystal display element was produced by laminating a polarizing plate on the substrate.
A voltage of 5 V was applied to the liquid crystal display element at room temperature for 60 microseconds in application time of 16.7 milliseconds, and the voltage holding ratio after 16.7 milliseconds from release of application was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation.
[Evaluation of vertical alignment]
Using a liquid crystal display device produced in the same manner as in [Evaluation of voltage holding ratio], the alignment state at the time of voltage OFF and AC 12 V (peak-peak) was observed under crossed Nicols. The case where the orientation was uniform in the plane and the orientation was excellent was designated as “◯”.
[Burn-in test]
A liquid crystal display device was produced in the same manner as in [Evaluation of voltage holding ratio] except that a glass substrate having an ITO film having a pattern as shown in FIG. 1 was used on one side.
In this liquid crystal display element, 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 removing the voltage, a DC voltage of 0.1 to 5.0 V was applied to each of the electrodes A and B in increments of 0.1 V, and the burn-in characteristics were determined based on the luminance difference between the electrodes A and B at each voltage. That is, it was determined that the burn-in characteristic was bad when the luminance difference was large. A sample in which no image sticking was observed (a luminance difference was not observed between both electrodes) was indicated as “◯”.

<Example of monomer synthesis>
Monomer Synthesis Example 1 (Synthesis of 1- (3,5-diaminophenyl) -3-decylsuccinimide)
In a 300 mL three-necked flask replaced with nitrogen gas, 12.82 g (0.07 mol) of 3,5-dinitroaniline and 70 mL of acetic acid were added, and the solid matter was dissolved by stirring while circulating nitrogen gas. To this, 16.8 g (0.07 mol) of decylsuccinic anhydride was added, and the mixture was reacted by refluxing for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The precipitated solid was separated by filtration, washed with methanol and then dried to obtain 23 g (0.057 mol, yield 81%) of 1- (3,5-dinitrophenyl) -3-decylsuccinimide.
Next, in a 500 mL flask substituted with nitrogen gas, 22.7 g (0.056 mol) of 1- (3,5-dinitrophenyl) -3-decylsuccinimide synthesized above, 100 mL of ethanol, 100 mL of tetrahydrofuran (THF) and reduction were performed. 25 g of catalyst palladium carbon (Pd / C) was added and stirred at 70 ° C. for 1 hour. To this was added 42.5 mL (43.75 g) of hydrazine monohydrate, and the mixture was heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The obtained crude product was dissolved by heating in N-methyl-2-pyrrolidone, then cooled and recrystallized to obtain 11.2 g of 1- (3,5-diaminophenyl) -3-decylsuccinimide as the desired product. (0.032 mol, yield 58%) was obtained.

Monomer Synthesis Example 2 (Synthesis of 1- (3,5-diaminophenyl) -3-octylsuccinimide)
1- (3,5 in the same manner as in Monomer Synthesis Example 1, except that 14.84 g (0.07 mol) of octyl succinic anhydride was used instead of 16.8 g (0.07 mol) of decyl succinic anhydride. -Diaminophenyl) -3-octylsuccinimide (8.88 g, 0.028 mol, yield 50%) was obtained.

Monomer Synthesis Example 3 (Synthesis of 1- (3,5-diaminophenyl) -3-undecyl-4-methylmaleimide)
A nitrogen-substituted 2,000 mL three-necked flask was charged with 25.2 g (0.25 mol) of dimethylmaleic anhydride, 71.2 g (0.5 mol) of N-bromosuccinimide, 1.0 g (4.15 mol) of benzoyl peroxide and tetrachloride. 1,500 mL of carbon was added and heated to reflux for 5 h. After cooling the reaction solution to room temperature, 01.0 g (4.15 mmol) of benzoyl peroxide was added, and the mixture was further heated to reflux for 5 h. The reaction solution was allowed to stand at room temperature overnight and then filtered. After the filtrate was washed with water, the organic layer was concentrated on a rotary evaporator. The obtained oily crude product was distilled under high vacuum (120 to 125 ° C./2 mmHg) to obtain 20 g of an intermediate 3-bromomethyl-4-methylmaleic anhydride (yield 39%).
Next, in a 2,000 mL three-necked flask replaced with argon gas, 16.4 g (0.08 mol) of 3-bromomethyl-4-methylmaleic anhydride obtained above, 1.52 g (8 mmol) of copper iodide, After adding 400 mL of diethyl ether and 160 mL of HMPA (hexamethylphosphoric triamide), the mixture was cooled to −5 to 0 ° C. under argon gas flow. While stirring this mixed solution, a solution prepared by dissolving 400 mmol of hexadecyl bromide separately prepared in 400 mL of diethyl ether was added dropwise over about 20 minutes. The mixture was returned to room temperature and further stirred for 8 h. Next, the mixture was diluted with 600 mL of diethyl ether, and then 600 mL of 4N-sulfuric acid was added to make the solution acidic. The separated aqueous layer was washed with 15 mL of diethyl ether, and the organic layers were combined. The organic layer was washed with water and dehydrated with sodium sulfate, and then the solution was concentrated on a rotary evaporator to obtain an oily crude product. This crude product was purified on a silica gel column using petroleum ether / ethyl acetate (19: 1) mixed solution as a developing solvent, and 10.8 g of 3-undecyl-4-methylmaleic anhydride (yield 50%) was obtained. Obtained.

Next, 6.41 g (0.035 mol) of 3,5-dinitroaniline and 35 mL of acetic acid were added to a 200 mL three-neck flask purged with nitrogen gas. Stirring while flowing nitrogen gas, the solid matter was dissolved. To this was added 9.31 g (0.035 mol) of 3-undecyl-3-methylmaleic anhydride obtained above, and the mixture was refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 35 mL of methanol was added and allowed to stand overnight. The solid was separated by filtration, washed with methanol, and dried to obtain 12.3 g (yield 82%) of 1- (3,5-dinitrophenyl) -3-undecyl-4-methylmaleimide.
Next, 11.2 g (0.026 mol) of 1- (3,5-dinitrophenyl) -3-undecyl-4-methylmaleimide, 50 mL of ethanol, 50 mL of THF, and reduction catalyst Pd / C 12 were added to a 300 mL flask purged with nitrogen gas. 0.5 g was added and stirred at 70 ° C. for 1 hour. Next, 19 mL (19.6 g) of hydrazine monohydrate was added, and the mixture was heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The obtained crude product was recrystallized by heating and dissolving with N-methyl-2-pyrrolidone and cooled to give the desired product 1- (3,5-diaminophenyl) -3-undecyl-4-methyl. 5.5 g of maleimide (0.015 mol yield 57%) was obtained.

Monomer Synthesis Example 4 (Synthesis of 1- (3,5-diaminophenyl) -3-decanoxymethyl-4-methylmaleimide)
After adding 12.82 g (0.07 mol) of 3,5-dinitroaniline and 70 mL of acetic acid to a 500 mL three-necked flask purged with nitrogen, the solid was dissolved by stirring while circulating nitrogen gas. To this, 14.35 g (0.07 mol) of 3- (bromomethyl) -4-methylmaleic anhydride synthesized in the same manner as the intermediate of the monomer synthesis example 3 was added, and the mixture was refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The solid content was separated by filtration, washed with methanol and dried to obtain 18.9 g of 1- (3,5-dinitrophenyl) -3-bromomethyl-4-methylmaleimide (yield 73%).
Next, in a 500 mL three-necked flask purged with nitrogen, 18.1 g (0.049 mol) of 1- (3,5-dinitrophenyl) -3-bromomethyl-4-methylmaleimide and 8.82 g of 1-hexadecanol sodium salt (0 0.049 mol) and 100 mL of dimethyl sulfoxide were added, and the mixture was stirred and reacted at 100 ° C. for 10 hours. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The solid content was separated by filtration, washed with methanol and dried to obtain 17.7 g (yield 81%) of 1- (3,5-dinitrophenyl) -3-decanoxymethyl-4-methylmaleimide.
Next, 11.6 g (0.026 mol) of 1- (3,5-dinitrophenyl) -3-decanoxymethyl-4-methylmaleimide, 50 mL of ethanol, 50 mL of THF, and reduction catalyst Pd / C were added to a 300 mL flask purged with nitrogen gas. 5 g was added and stirred at 70 ° C. for 1 hour. Thereafter, 19 mL (39.2 g) of hydrazine monohydrate was added and heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The obtained crude product was recrystallized by heating and dissolving with N-methyl-2-pyrrolidone and cooling, and the desired product 1- (3,5-diaminophenyl) -3-decanoxymethyl-4-methyl was obtained. 6.5 g of maleimide (0.017 mol yield 65%) was obtained.

<Polymer synthesis example>
Synthesis Examples 1-8
To the N-methylpyrrolidone, a diamine and tetracarboxylic dianhydride having the composition shown in Table 1 are added in this order to obtain a solution having a monomer concentration of 20% by weight, and reacted at 60 ° C. for 4 hours to give a polyamic acid (A-1). A solution containing ~ (A-8) was obtained. After adding 3.0 times mole (equivalent) pyridine and 3.0 times mole (equivalent) acetic anhydride to each polyamic acid solution obtained, relative to the total amount (mole) of amic acid units in the solution, respectively. The mixture was heated to 110 ° C. and subjected to dehydration ring closure reaction for 4 hours. The resulting solution was reprecipitated with diethyl ether, collected, and dried under reduced pressure to obtain imidized polymers (B-1) to (B-8). Table 1 shows the imidization ratio of these imidized polymers.
Synthesis Examples 9 and 10
Diamine and tetracarboxylic dianhydride having the composition shown in Table 1 were added to N-methylpyrrolidone in this order to obtain a solution having a monomer concentration of 20% by weight, and reacted at 60 ° C. for 4 hours. The resulting solution was reprecipitated with diethyl ether, collected, and dried under reduced pressure to obtain polyamic acids (A-9) and (A-10). In Polymer Synthesis Examples 9 and 10, no imidation reaction was performed.

In Table 1, for diamines and acid anhydrides, the numbers in parentheses indicate the content ratio (molar ratio), and the meanings of the symbols in the table are as follows.
<Diamine>
Specific diamine A: 1- (3,5-diaminophenyl) -3-decylsuccinimide Specific diamine B: 1- (3,5-diaminophenyl) -3-octylsuccinimide Specific diamine C: 1- (3,5-diamino Phenyl) -3-undecyl-4-methylmaleimide Specific diamine D: 1- (3,5-diaminophenyl) -3-decanoxymethyl-4-methylmaleimide diamine 1: 4,4′-diaminodiphenylmethane <tetracarboxylic dianhydride Things>
T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride T-2: 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Acid anhydride T-3: Pyromellitic dianhydride T-4: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

Example 1
The imidized polymer B-1 obtained in Synthesis Example 1 and the polyamic acid A-9 obtained in Synthesis Example 9 were mixed with a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40:30:30). 2 types of solutions having a solid content concentration of 3.5 wt% and 5 wt% were prepared. Each of these solutions was filtered with a filter having a pore size of 0.2 μm to obtain two types of liquid crystal aligning agents having different solid content concentrations.
Various evaluations were performed according to the above-described methods using these liquid crystal aligning agents. The results are shown in Table 2.
Examples 2-14
Liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the types and amounts of the polymers blended in the liquid crystal aligning agent were as shown in Table 2. Table 2 shows the results of evaluations performed using these aligning agents according to the method described above.

It is a schematic diagram which shows the pattern of the ITO electrode of the liquid crystal display element produced for evaluation of image sticking in an Example and a comparative example.

Claims (3)

The following formula (I-1)

(In formula (I-1), P ¹ is a tetravalent organic group, at least a part of which is represented by the following formulas (III-1) and (III-2)

Q ¹ is represented by the following formulas (II-1) to (II-4) having at least one selected from the group of structural units represented by

(In formulas (II-1) to (II-4), R ^{1 to} R ⁴ are each a linear, branched or cyclic alkyl group having 1 to 11 carbon atoms, or a linear or branched group having 4 to 11 carbon atoms. A branched or cyclic alkenyl group, wherein ¹ to 7 hydrogen atoms of R ^{1 to} R ⁴ may be substituted with fluorine atoms, and A ¹ and A ² are each independently a hydrogen atom or methyl Group.)
It is a bivalent group represented by either. )
The liquid crystal aligning agent characterized by including the polymer which has a structural unit represented by these. Furthermore, the following formula (I-2)

(In Formula (I-2), P ² is a tetravalent organic group, and Q ² is a divalent organic group.)
Containing a polymer having no structural unit represented by in represented by a structural unit and the above formula (I-1), a liquid crystal aligning agent of claim 1. Characterized by comprising a liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1 or 2, the liquid crystal display device.

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