KR101947855B1

KR101947855B1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: KR101947855B1
Application number: KR1020147022573A
Authority: KR
Inventors: 아름 김; 히로미츠 마츠모토
Original assignee: 닛산 가가쿠 가부시키가이샤
Priority date: 2012-01-18
Filing date: 2013-01-17
Publication date: 2019-02-13
Also published as: CN104169789A; TWI591098B; JP5999107B2; TW201348293A; JPWO2013108854A1; KR20140114876A; WO2013108854A1

Abstract

A liquid crystal alignment film having a high voltage holding ratio and excellent alignment property of liquid crystal.
A liquid crystal alignment containing a polyamic acid obtained from a tetracarboxylic acid dianhydride component containing a diamine component containing diamines of the formulas (1) and (2) and a tetracarboxylic acid dianhydride having an alicyclic structure or aliphatic structure My.
(Formula 1)

(X ₁ Is at least one kind of divalent organic group selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, and -OCO-, Q ¹ Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₂ Is a single bond or at least one kind of divalent organic group selected from the group consisting of an aliphatic hydrocarbon group of 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group, X ₃ Is a single bond, or ^{-O-, -NQ 2 -, -CONQ 2} -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 ), At least one divalent organic group selected from the group consisting of Q ² Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₄ A nitrogen-containing aromatic heterocyclic group, n is an integer of 1 to 4, and n is an integer of 3 to 10)

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment film, a liquid crystal alignment film, a liquid crystal alignment film,

The present invention relates to a liquid crystal aligning agent for producing a liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element comprising the liquid crystal alignment film.

At present, as a liquid crystal alignment film used in a liquid crystal display device, a liquid crystal alignment treatment agent (also referred to as a liquid crystal aligning agent) containing as a main component a solution of a polyimide precursor such as polyamic acid (also referred to as polyamic acid) or soluble polyimide, A so-called polyimide-based liquid crystal alignment film obtained by coating and firing is mainly used.

The liquid crystal aligning agent using a polyimide precursor such as polyamic acid can be easily obtained by reacting a tetracarboxylic acid dianhydride as a raw material with a diamine compound in a solvent and diluting it with an appropriate concentration for film formation. However, the soluble polyimide is required to chemically imidize the polyamic acid solution after preparation of the polyamic acid solution, and to dissolve the obtained polyimide powder in the solvent again, so that the process is complicated and there is a problem in productivity. Therefore, it is preferable from the viewpoint of productivity that a liquid crystal alignment film using a polyamic acid can satisfy the property required for the liquid crystal alignment film.

However, a liquid crystal alignment film using a polyimide precursor such as polyamic acid generally has good applicability to a glass substrate, but has a problem in terms of voltage holding ratio and liquid crystal alignability.

As a liquid crystal alignment treatment agent which uses a polyimide precursor such as polyamic acid or the like and has a high voltage holding ratio and is capable of alleviating the residual charge accumulated by a direct current voltage, a liquid crystal alignment treatment using a diamine compound containing a nitrogen containing aromatic heterocyclic ring in the side chain An orientation treatment agent has been proposed (see Patent Document 1). In recent years, however, a liquid crystal display with a high precision has been widely put to practical use, and liquid crystal display devices for such applications are required to have higher levels of liquid crystal alignability and voltage holding characteristics.

WO2009 / 093704

An object of the present invention is to provide a liquid crystal alignment film using a polyamic acid which has a high voltage holding ratio and is excellent in orientation of liquid crystals.

The inventors of the present invention have conducted intensive studies in order to achieve the above object and as a result, it has been found that by using a polyamic acid obtained by reacting a diamine compound using a plurality of specific diamines with a tetracarboxylic acid dianhydride, I found out. That is, the present invention is based on this finding, and has the following points.

(1) a tetracarboxylic acid dianhydride component containing a diamine component containing a diamine compound represented by the following formula (1) or (2) and a tetracarboxylic acid dianhydride having an alicyclic structure or alicyclic structure; A liquid crystal aligning agent containing polyamic acid.

[Chemical Formula 1]

(In the formula (1), X ₁ Is at least one kind of divalent organic group selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, and -OCO-, Q ¹ Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. X ₂ Is at least one kind of divalent organic group selected from the group consisting of a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group. X ₃ Is a single bond, or ^{-O-, -NQ 2 -, -CONQ 2} -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 , And Q < ² > is at least one kind of divalent organic group selected from the group consisting of Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. X ₄ Is a nitrogen-containing aromatic heterocyclic group, and n is an integer of 1 to 4.

N in the formula (2) is an integer of 3 to 10.)

(2) The liquid crystal aligning agent according to (1), wherein the polyamic acid has a weight average molecular weight of 5,000 to 1,000,000.

(3) X ₁ in the formula (1) Is at least one member selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, and -NQ ¹ CO-, X ₂ A straight chain alkylene group having 1 to 3 carbon atoms, and a benzene ring, and X < ₃ > is at least one member selected from the group consisting of Is at least one member selected from the group consisting of -OCO- and -OCH ₂ -, X ₄ Is at least one member selected from the group consisting of an imidazole ring, a pyridine ring and a pyrimidine ring, and n is an integer of 1 or 2. 2. A liquid crystal aligning agent according to the above (1) or (2)

(4) The liquid crystal aligning agent according to any one of (1) to (3), wherein the diamine of the formula (1) is 5 to 50 mol% of the total diamine component.

(5) X ₄ in the formula (1) (1) to (4), wherein R < 1 > is a pyridine ring or an imidazole ring.

(6) The liquid crystal aligning agent according to any one of (1) to (5), wherein the diamine of the formula (2) is 10 to 50 mol% of the total diamine component.

(7) The liquid crystal aligning agent according to any one of (1) to (6), wherein n in the formula (2) is an integer of 3 to 8.

(8) The liquid crystal aligning agent according to any one of (1) to (7), wherein the tetracarboxylic acid dianhydride component further contains an aromatic tetracarboxylic acid dianhydride.

(9) A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of (1) to (8).

(10) The liquid crystal alignment film according to (9) above, wherein the liquid crystal aligning agent contains 80-99 mass% of an organic solvent based on the entire liquid crystal aligning agent (100 mass%).

(11) The process according to (1) above, wherein the organic solvent is at least one selected from the group consisting of N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl- But are not limited to, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, gamma -butyrolactone, 1,3-dimethyl- imidazolidinone, Ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, and 4-hydroxy-4-methyl-2-pentanone The liquid crystal alignment film according to the above (10), which is at least one kind.

(12) A liquid crystal display element comprising the liquid crystal alignment film according to any one of (9) to (11).

According to the present invention, it is possible to provide a polyamic acid-based liquid crystal alignment film having good voltage holding ratio characteristics and having better liquid crystal alignment properties than conventional ones.

Hereinafter, the present invention will be described in detail.

The present invention relates to a process for producing a polyimide precursor which comprises reacting a diamine component containing a diamine compound represented by the formula (1) (also referred to as a specific diamine compound 1) and a diamine compound represented by the formula (2) A tetracarboxylic acid dianhydride having a tetracarboxylic acid dianhydride, and a liquid crystal alignment film obtained by using the liquid crystal aligning agent, and furthermore, a liquid crystal alignment film obtained by using a liquid crystal alignment film containing the liquid crystal alignment film, Display device.

&Lt; Specific diamine compound 1 >

The specific diamine compound 1 used in the liquid crystal aligning agent of the present invention is a diamine compound represented by the following formula (1).

(2)

In formula [1], X ₁ represents at least one kind of 2 selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O- and -OCO- And Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

X ₂ Is at least one kind of divalent organic group selected from the group consisting of a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group.

X ₃ Is a single bond, or ^{-O-, -NQ 2 -, -CONQ 2} -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 , And Q < ² > is at least one kind of divalent organic group selected from the group consisting of Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

X ₄ Is a nitrogen-containing aromatic heterocyclic group, and n is an integer of 1 to 4.

The content of the compound represented by the formula (1) in the total diamine component is preferably 5 to 50 mol%, more preferably 10 to 40 mol%.

The bonding position of two amino groups (-NH ₂ ) in the formula (1) is not limited.

Specifically, when n is 1, positions of 2,3 and 4, 2, 5, 2, 6, 3, 4, 5 and 6 on the benzene ring on the side chain bonding unit (X ₁ ) Position 4, positions 3 and 5, and so on.

when n is 2, for example, side and one of the couplers (X ₁₎ to the coupler (X ₁₎ of the chain is, in the case where the position in the benzene ring 2, a combination of two amino position, 3 , Position 4, positions 3 and 5, positions 3 and 6, positions 4 and 5, and the like. The side and one of the couplers (X ₁₎ to the coupler (X ₁₎ of the chain is, in the case of the on the benzene ring 3 position, the coupling position of the two amino groups, two of the 4-position, 2,5 position , Positions 4 and 5, positions 4 and 6, and the like. In addition, side chain coupler (X ₁₎ and one of the couplers (X ₁₎ for the on, if on the on the benzene ring 4-position, with respect to coupler (X ₁₎ of the side chain, two binding of the amino group location , 2, 3, 2, 5, 2, 6, 3, 5, respectively.

when n represents 3, for example, a side coupler (X ₁₎ two different combiner (X ₁₎ for the chain is, in the case where the 2 and 3 position on the benzene ring, the bonding position of the two amino groups , Positions 4 and 5, positions 4 and 6, and the like. In addition, side chain coupler (X ₁₎ two different combiner (X ₁₎ for the of the case in the 2 and 4 positions on the benzene ring, the bonding position of the two amino groups, of 3 and 5 position, 3, Position 6, positions 5 and 6, and so on. In addition, the side coupler (X ₁₎ two different combiner (X ₁₎ for the chain is, in the case where the 3 and 5 position on the benzene ring, the number of the two coupling positions of the two amino groups is 2, the 4-position of the have.

When n is 4, for example, when three different couplers (X ₁ ) to the coupler (X ₁ ) in the side chain are at positions 2, 3 and 4 on the benzene ring, The position is 5, 6 position. When three different couplers (X ₁ ) to the coupler (X ₁ ) of the side chain are located at positions 2, 4 and 5 on the benzene ring, the bonding positions of the two amino groups are positions 3 and 6 . When three different couplers (X ₁ ) are located at positions 2, 4 and 6 on the benzene ring with respect to the coupler (X ₁ ) of the side chain, the bonding positions of the two amino groups are at positions 3 and 5 .

Among them, from the viewpoints of the reactivity in the synthesis of the polyamic acid and the easiness in the synthesis of the diamine compound, it is preferable that the bonding position of the two amino groups is 2, 4, 2, the 5-position, 3, 5-position, or n in the case where the second, sides and one of the couplers (X ₁₎ to the coupler (X ₁₎ of the chain have, in a on the benzene ring 3 position , The positions of bonding positions of the two amino groups of 4 and 6 are particularly preferable.

In formula [1], X ₁ represents at least one kind of 2 selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O- and -OCO- And the like. Among them, -O-, -NQ ¹ -, -CONQ ¹ -, and -NQ ¹ CO- are preferable. Q ¹ is the definition and agreement of Equation [1].

Specific examples of preferred compounds having the structure of X < ₁ > include the following formulas [1a] to [1f].

(3)

Among them, compounds represented by formulas [1a], [1b], [1c] and [1d] are preferable. Q ¹ is the definition and agreement of Equation [1].

In the formula [1], X ₂ Is at least one kind of divalent organic group selected from the group consisting of a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group.

The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear or branched. It may also have an unsaturated bond. Preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

Specific examples of the non-aromatic cyclic hydrocarbon group include a cyclopropane ring, a cyclopentane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, a cyclododecane ring, a cyclododecane ring, And examples thereof include a ring, a cyclotetradecane ring, a cyclotetradecane ring, a cyclopentadecane ring, a cyclohexadecane ring, a cycloheptadecane ring, a cyclooctadecane ring, a cyclononadecane ring, a cyclooctadecane ring, a tricyclohexane ring, A decanoic acid ring, a bicycloheptane ring, a decahydronaphthalene ring, a norbornene ring, an adamantane ring and the like.

Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring and a phenrenylene ring.

Examples of the preferable X ₂ in the formula [1] include a single bond, a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, A cyclohexane ring, a cycloheptane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, a fluorene ring and an anthracene ring, more preferably a single bond, An alkylene group having 1 to 10 carbon atoms, a linear or branched alkylene group, an alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a fluorene ring and an anthracene ring, An alkylene group having 1 to 10 carbon atoms, a linear or branched alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a benzene ring and a naphthalene ring, particularly preferably a single bond, Straight-chain or branched alkylene group, a benzene ring. Most preferably, it is a single bond, a straight chain alkylene group having 1 to 3 carbon atoms, or a benzene ring.

In the formula [1], X ₃ Is a single bond, or ^{-O-, -NQ 2 -, -CONQ 2} -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 -O-, -CONQ ² -, -NQ ² CO-, -COO-, -OCO-, -O (= O) -, (CH ₂ ) _m - (m is an integer of 1 to 5). Most preferably, a single bond, -OCO-, -OCH ₂ - a. Further, Q ² Is the definition and agreement of Equation [1].

In the formula [1], X ₄ Is a nitrogen-containing aromatic heterocyclic group and is a nitrogen-containing aromatic heterocyclic group containing at least one structure selected from the group consisting of the following formulas [2a], [2b] and [2c].

[Chemical Formula 4]

In formula [2c], Y ₁ is a linear or branched alkyl group having 1 to 5 carbon atoms.

Preferred X ₄ in the formula [1] include a pyrrole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a pyrazoline ring, an isoquinoline ring, A pyrazoline ring, a pyrazoline ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a benzoimidazole ring, a chinoline ring, a pyrazoline ring, A thiophene ring, a phenanthroline ring, an indole ring, a quinoxaline ring, a benzothiazole ring, a phenothiazine ring, an oxadiazole ring and an acridine ring, more preferred are pyrrole ring, imidazole ring, pyrazole ring, , Pyrimidine ring, pyrazoline ring, carbazole ring, pyridazine ring, pyrazoline ring, triazine ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring, More preferred are pyrrole rings, imidazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, triazine rings, triazole rings, pyrazine rings, benzimidazole rings, and benzimidazole rings , Particularly preferred are a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring and a pyrimidine ring. Most preferably, it is an imidazole ring, a pyridine ring, or a pyrimidine ring.

In the formula [1], n is an integer of 1 to 4, preferably an integer of 1 to 3 in view of reactivity with the tetracarboxylic acid dianhydride. Most preferably, n is an integer of 1 or 2.

Preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are those wherein X ₁ is -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, and -OCO-, and X < ₂ > is at least one member selected from the group consisting of Is a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a norbornene ring, Is at least one member selected from the group consisting of a benzene ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, a fluorene ring, and an anthracene ring, and X ₃ Two ^{bond, -O-, -NQ 2 -, -CONQ} 2 -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 ), And at least one selected from the group consisting of X ₄ A pyrimidine ring, a pyrimidine ring, a quinoline ring, a pyrazoline ring, an isoquinoline ring, a carbazole ring, a pyridine ring, a thiadiazole ring, an imidazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, A pyrazoline ring, a pyrazolidine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a benzimidazole ring, a chinolin ring, a phenanthroline ring, an indole ring, a quinoxaline ring, Benzothiazole ring, phenothiazine ring, oxadiazole ring, and acridine ring, and n is an integer of 1 or 2.

More preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are those wherein X ₁ is -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, X ₂ is at least one member selected from the group consisting of Is a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a fluorene ring, And at least one selected from the group consisting of X ₃ Two ^{bond, -O-, -NQ 2 -, -CONQ} 2 -, -NQ 2 CO-, -COO -, - OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 ), And at least one selected from the group consisting of X ₄ A pyrimidine ring, a pyrimidine ring, a pyrazoline ring, a carbazole ring, a pyridazine ring, a pyrazoline ring, a triazine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, an imidazole ring, , Benzimidazole ring, and benzimidazole ring, and n is an integer of 1 or 2.

More preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are those wherein X ₁ is -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, CH ₂ O-, and -OCO-, and X ₂ Is at least one member selected from the group consisting of a linear or branched alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a benzene ring, and a naphthalene ring, X ₃ Is a group consisting of -O-, -CONQ ² -, -NQ ² CO-, -COO-, -OCO-, and -O (CH ₂ ) _m - (m is an integer of 1 to 5) At least one selected, and X ₄ Is selected from the group consisting of a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, and a benzimidazole ring And n is an integer of 1 or 2.

Especially preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are those wherein X ₁ is -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, X ₂ is at least one member selected from the group consisting of An alkylene group having 1 to 5 carbon atoms, a linear or branched alkylene group having 1 to 5 carbon atoms, and a benzene ring, and X ₃ Is a group consisting of -O-, -CONQ ² -, -NQ ² CO-, -COO-, -OCO-, and -O (CH ₂ ) _m - (m is an integer of 1 to 5) At least one selected, and X ₄ Is at least one member selected from the group consisting of a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, and a pyrimidine ring, and n is an integer of 1 or 2.

The most preferable combination of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] is X ₁ is -O-, -NQ ¹ -, -CONQ ¹ -, and -NQ ¹ CO- , X ₂ is at least one member selected from the group consisting of a single bond, a straight chain alkylene group having 1 to 3 carbon atoms, and a benzene ring, and X ₃ Is at least one member selected from the group consisting of -OCO- and -OCH ₂ -, X ₄ Is at least one member selected from the group consisting of an imidazole ring, a pyridine ring and a pyrimidine ring, and n is an integer of 1 or 2.

Particularly preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are as shown in Tables 1 to 3 below. Further, Q ¹ and Q ² Is the definition and agreement of Equation [1].

&Lt; Specific diamine compound 2 >

The specific diamine compound 2 used in the liquid crystal aligning agent of the present invention is a diamine compound represented by the following formula (2).

[Chemical Formula 5]

In the formula (2), n is an integer of 3 to 10, but is preferably 3 to 8, and more preferably 5 to 7 from the viewpoint of liquid crystal alignability.

The content of the compound represented by the formula (2) in the total diamine component is preferably 10 to 60 mol%, more preferably 40 to 60 mol%.

&Lt; Other diamine compounds >

In the present invention, diamines other than the specific diamine compound (hereinafter, also referred to as other diamine compounds) may be used in combination, as long as the effect of the present invention is not impaired, and other diamine compounds are not particularly limited. Specific examples thereof are shown below.

p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl- Diaminodiphenol, 3,5-diaminophenol, 3,5-diaminobenzyl, 2,4-diaminophenol, 3,5-diaminophenol, Alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'- Phenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'- Phenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'- Diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldi aniline, 3,3'-sulfo Bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4'-thiodi Aniline, 3,3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-dia Aminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl) amine, N-methyl (3,3'- diaminodiphenyl) Methyl (2,2'-diaminodiphenyl) amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4 ' -Diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diaminobenzophenone, 2,3'-di Minobenzophenone, 1,5-diaminonaphthalene, 1,6-diamino-naphthalene There may be mentioned phthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene, 2,7-diaminonaphthalene, Bis (3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,3- Propane, 1,4-bis (4-aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4 '- [1,4-phenylenebis (methylene)] dianiline, 4,4' - [ Phenylenebis (methylene)] dianiline, 3,4 '- [1,4-phenylenebis (methylene)] dianiline, 3,4' - [ ] Dianiline, 3,3 '- [1,4-phenylenebis (methylene)] dianiline, 3,3' - [1,3-phenylenebis Tylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3- (4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylene bis (4-aminobenzoate), 1,3-phenylene bis (3-aminobenzoate) Aminophenyl) isophthalate, N, N '- (1,4-phenylene) bis (4-aminobenzamide), bis N, N '- (1, 3-phenylene) bis (4-aminobenzamide), N, N' N, N'-bis (3-aminophenyl) terephthalamide, N, N'-bis (4-aminophenyl) terephthalamide, - bis (4-aminophenyl) iso Bis (4-aminophenoxy) diphenyl sulfone, 2, 3-aminophenyl) isophthalamide, N, Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2'-bis (4 (Aminophenyl) hexafluoropropane, 2,2'-bis (3-aminophenyl) hexafluoropropane, 2,2'- Bis (3-aminophenyl) propane, and 2,2'-bis (3-aminophenyl) Bis (3-aminophenoxy) butane, 1, 5-bis (3-aminophenoxy) Bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) pentane, 1,6-bis ) Hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- Heptane, 1,8-bis (4-aminophenoxy) octane, 1,8-bis Bis (3-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, 1,10- 1,11- (3-aminophenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane. Aminocyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1, Diaminohexane, 1,8-diaminohexane, 1,6-diaminohexane, 1,6-diaminohexane, 1,6- 12-diaminododecane, and the like.

Further, diamines having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and a substituent having a substituent in the side chain of diamine may be cited. Specifically, the diamine compounds represented by the following formulas [DA1] to [DA26] can be exemplified.

[Chemical Formula 6]

(In the formulas [DA1] to [DA5], R ₁ is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.

(7)

(Of the formulas [DA6] to [DA9], R₂ Is -COO-, -OCO-, -CONH-, -NHCO-, -CH₂-, -O-, -CO-, or -NH-, R₃ Is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.)

[Chemical Formula 8]

(Of the formulas [DA10] and [DA11], R ₄ Is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, R ₅ Is an alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.

[Chemical Formula 9]

(Of the formulas [DA12] to [DA14], R ₆ Is, -COO-, -OCO-, -CONH-, -NHCO- , -COOCH 2 -, -CH 2 OCO-, -CH 2 O-, -OCH 2 -, or -CH ₂ -, and, R ₇ Is an alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.

[Chemical formula 10]

(Wherein [DA15] and formula [DA16], R ₈ -CO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ -, -O- or -NH-, and R < ₉ > Is a fluorine, cyano, trifluoromethane, nitro, azo, formyl, acetyl, acetoxy or hydroxyl group.

(11)

[Chemical Formula 12]

[Chemical Formula 13]

In addition, diaminosiloxane and the like represented by the following formula [DA27] are also exemplified.

[Chemical Formula 14]

(In the formula [DA27], m is an integer of 1 to 10.)

The other diamine compounds may be used alone or in combination of two or more thereof, depending on the properties such as liquid crystal aligning property, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

&Lt; Tetracarboxylic acid dianhydride >

In order to obtain the polyamic acid contained in the liquid crystal aligning agent of the present invention, the tetracarboxylic acid dianhydride component to be reacted with the diamine component contains a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure.

Examples of the tetracarboxylic acid dianhydride having an alicyclic or aliphatic structure include 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane tetra Carboxylic acid dianhydride, 1,3-dimethyl-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, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,2,4,5- Cyclohexanetetracarboxylic acid dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 1 , 2,3,4-butanetetracarboxylic acid dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid dianhydride, 3,3 ', 4,4' - dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, -3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dianhydride, tricyclo [4.2.1.02,5] nonane- Tetracarboxylic acid-3,4: 7,8-2 anhydride, hexacyclo [6.6.0.12,7.03,6.19,14.010,13] hexadecane, 4,5,11,12-tetracarboxylic acid- 11,12-2 anhydride, and 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride. have.

Among them, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 3,4-dicarboxy- 1-cyclohexylsuccinic dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride and the like are preferable.

Use of an aromatic tetracarboxylic acid dianhydride in addition to the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure improves the liquid crystal alignability and can reduce the accumulated charge of the liquid crystal cell.

Examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid Biphenyltetracarboxylic acid dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3', 4-benzo Phenanetetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid 2 Anhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, and the like.

Among them, pyromellitic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid dianhydride, 2,3,3', 4-biphenyltetracarboxylic dianhydride and the like are preferable.

The aromatic tetracarboxylic acid dianhydride is preferably contained in an amount of 0 to 50 mol%, more preferably 0 to 30 mol%, of the total tetracarboxylic acid dianhydride.

The tetracarboxylic acid dianhydride component can be used alone or in combination of two or more, depending on the properties such as liquid crystal aligning property, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

The tetracarboxylic acid dianhydride having an alicyclic structure or aliphatic structure is preferably at least 50 mol%, more preferably at least 70 mol%, of the total tetracarboxylic acid dianhydride components. Especially preferred is 75 to 100 mol%.

&Lt; Synthesis of polyamidic acid >

By reacting the tetracarboxylic acid dianhydride component containing the tetracarboxylic acid dianhydride having an alicyclic structure or aliphatic structure with the diamine component containing the specific diamine component 1 and 2, , A known synthetic method can be used.

Generally, the tetracarboxylic acid dianhydride component and the diamine component are reacted in an organic solvent. The reaction of the tetracarboxylic acid dianhydride with the diamine is advantageous in that it proceeds comparatively easily in an organic solvent and does not generate any by-products.

The organic solvent used for the reaction of the tetracarboxylic acid dianhydride and the diamine is not particularly limited as long as it dissolves the produced polyamic acid. Specific examples thereof are given below.

N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, methyl ethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, ethyl cellosolve, ethyl cellosolve, methyl cellosolve, But are not limited to, sorbose, methylcellosolve acetate, ethylcellosolve acetate, butylcarbitol, ethylcarbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate , Propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethyl Diethylene glycol monoacetate monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monoacetate monoethyl ether, Propyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, N-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, propylene carbonate, propylene carbonate, Methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoacetate 3-methoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, propyl 3-methoxypropionate, ethyl 3-ethoxypropionate, Butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone and the like. These may be used alone or in combination. In addition, a solvent which does not dissolve the polyamic acid may be used in a mixed solvent as long as the produced polyamic acid is not precipitated.

In addition, the water content in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the resulting polyamic acid. Therefore, it is preferable to use an organic solvent that is dehydrated and dried as much as possible.

When the tetracarboxylic acid dianhydride component and the diamine component are reacted in the organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred and the tetracarboxylic acid dianhydride component is dispersed or dissolved in the organic solvent A method of adding a diamine component to a solution in which a tetracarboxylic acid dianhydride component is dispersed or dissolved in an organic solvent, a method of alternately adding a tetracarboxylic acid dianhydride component and a diamine component, and the like You can use either method. When the tetracarboxylic acid dianhydride component or the diamine component is composed of a plurality of compounds, they may be reacted in advance in a mixed state, or they may be sequentially reacted individually, or the low molecular weight compounds reacted individually may be mixed and reacted, May be used.

The polymerization temperature at that time may be any temperature within the range of -20 to 150 ° C, preferably -5 to 100 ° C.

When the concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight. When the concentration is too high, the viscosity of the reaction liquid becomes too high and it becomes difficult to perform uniform stirring. Therefore, The total concentration of the acid dianhydride and the diamine component in the reaction solution is preferably 1 to 50 mass%, more preferably 5 to 30 mass%. The reaction is carried out at a high concentration in the initial stage, and then an organic solvent can be added.

In the polymerization reaction of the polyamic acid, the ratio of the total number of moles of the tetracarboxylic acid dianhydride to the total number of the moles of the diamine component is preferably 0.8 to 1.2. As in the case of a typical polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the resulting polyamic acid.

The molecular weight of the polyamic acid contained in the liquid crystal aligning agent of the present invention is preferably in the range of from 0.1 to 10 parts by weight based on the weight measured by GPC (Gel Permeation Chromatography) method, considering the strength of the coating film obtained therefrom, the workability in forming the coating film, The average molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

The liquid crystal aligning agent of the present invention is a coating liquid for forming a liquid crystal alignment film and is a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component is a resin component containing the above-mentioned polyamic acid. At this time, the content of the resin component in the coating liquid is preferably from 1 to 20% by mass, more preferably from 3 to 15% by mass, and particularly preferably from 3 to 10% by mass.

In the liquid crystal aligning agent of the present invention, all of the above-mentioned resin components may be polyamide acid, and other polyamide acid may be mixed with polyamide acid. At this time, the content of the polymer other than the polyamic acid in the resin component is 0.5 to 15% by mass, preferably 1 to 10% by mass.

As the other polymer, for example, a polyamic acid obtained by using a diamine compound other than a specific diamine compound as the diamine component to be reacted with the tetracarboxylic acid dianhydride component can be given.

The organic solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is an organic solvent capable of dissolving the resin component. Specific examples thereof are given below.

N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N- Dimethyl sulfoxide, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide,? -Butyrolactone, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl Isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone and the like.

These may be used alone or in combination.

The content of the organic solvent used in the liquid crystal aligning agent of the present invention is 80 to 99 mass%, preferably 85 to 99 mass%, based on the entire liquid (liquid crystal aligning agent) (100 mass%).

The liquid crystal aligning agent of the present invention may contain components other than those described above. Examples thereof include a solvent or a compound that improves film thickness uniformity and surface smoothness when the liquid crystal aligning agent is applied, a compound that improves the adhesion between the liquid crystal alignment film and the substrate, and the like.

Specific examples of the solvent (poor solvent) for improving the uniformity of the film thickness and the surface smoothness include the following.

Examples of the solvent include isopropyl alcohol, methoxymethyl pentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl But are not limited to, carbitol acetate, carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, Monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl Ether, dipropylene glycol monopro Methyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, di Propyl ether, dihexyl ether, 1-hexanol, n-pentane, n-pentane, n-octane, diethyl ether , Methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methylethyl 3-ethoxypropionate, Methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-ethoxy-2-propanol, Propoxy Propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, There may be mentioned a solvent having a low surface tension such as 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester, lactic acid ethyl ester, n-propyl lactate, n-butyl lactate, .

These poor solvents may be used alone or in combination. When such a solvent is used, it is preferably 5 to 80 mass%, more preferably 20 to 60 mass%, of the total solvent contained in the liquid crystal aligning agent.

Examples of the compound that improves film thickness uniformity and surface smoothness include a fluorine-based surfactant, a silicon-based surfactant, and a nonionic surface-active agent.

(Manufactured by TOKEM PRODUCTS CO., LTD.), Megafac F171, F173, R-30 (manufactured by Dainippon Ink & Chemicals, Inc.), FLORAD FC430 and FC431 (manufactured by Sumitomo 3M Co., Ltd.) SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), and the like. The ratio of these surfactants to be used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass based on 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3 3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy (3-aminopropyl) Aminopropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N- Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N- Aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neo Pentyl glycol diglycidyl ether, 1,6-hexanediol 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-xylylenediamine, 1,3-bis (N, N-diglycidylamino Methyl) cyclohexane, N, N, N ', N', -tetraglycidyl-4,4'-diaminodiphenylmethane and the like.

When a compound improving the adhesion with the substrate is used, it is preferably used in an amount of 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component contained in the liquid crystal aligning agent . If the amount is less than 0.1 part by mass, the effect of improving the adhesion can not be expected. If the amount is more than 30 parts by mass, the alignment property of the liquid crystal may be deteriorated.

The liquid crystal aligning agent of the present invention may be a dielectric or a conductive material, and more preferably, a liquid crystal alignment film for the purpose of changing electric characteristics such as dielectric constant and conductivity of the liquid crystal alignment film, as long as the effect of the present invention is not impaired A crosslinking compound may be added for the purpose of increasing the hardness and density of the film at the time of the coating.

&Lt; Liquid crystal alignment film &

The liquid crystal aligning agent of the present invention can be used as a liquid crystal alignment film by applying it on a substrate, firing it, and then performing an orientation treatment such as rubbing treatment or light irradiation. In this case, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. It is preferable to use a substrate on which an ITO electrode or the like for liquid crystal driving is formed from the viewpoint of simplifying the process. In a reflection type liquid crystal display element, an opaque substrate such as a silicon wafer can be used as long as it is a substrate on only one side. In this case, a material that reflects light such as aluminum can also be used as the electrode in this case.

The method of applying the liquid crystal aligning agent is not particularly limited, but industrially, methods such as screen printing, offset printing, flexographic printing, and inkjet are generally used. As other coating methods, there are dips, roll coaters, slit coaters, spinners and the like, and they may be used depending on the purpose.

The baking after the liquid crystal aligning agent is coated on the substrate can be carried out by heating means such as a hot plate at 50 to 300 ° C, preferably 80 to 250 ° C, and the solvent can be evaporated to form a coated film.

When the thickness of the coating film formed after firing is too large, the power consumption of the liquid crystal display element is disadvantageously deteriorated. When the thickness is too thin, the reliability of the liquid crystal display element may deteriorate, preferably 5 to 300 nm, Is 10 to 100 nm.

When the liquid crystal is horizontally oriented or tilted, the coated film after firing is subjected to rubbing, polarized ultraviolet irradiation, or the like.

In the liquid crystal display element of the present invention, a substrate on which a liquid crystal alignment film is formed from the liquid crystal aligning agent of the present invention is obtained by the aforementioned method, and then a liquid crystal cell is produced by a known method to form a liquid crystal display element.

For example, a pair of substrates having a liquid crystal alignment film formed thereon is prepared, a spacer is spread on the liquid crystal alignment film of the substrate of the one substrate to make the liquid crystal alignment film surface inward, and the substrates of the other substrate are bonded A method in which a liquid crystal is injected under reduced pressure, or a method in which a liquid crystal is dropped on a surface of a liquid crystal alignment film on which a spacer is spread, and then the substrate is bonded and sealed. The thickness of the spacer at this time is preferably 1 to 30 占 퐉, more preferably 2 to 10 占 퐉.

As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention is excellent in voltage holding characteristics and liquid crystal alignability, and can be preferably used for a liquid crystal television with high precision on a large screen.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the interpretation of the present invention is not limited to these examples.

The abbreviations of the compounds used in this embodiment are as follows.

(Tetracarboxylic acid dianhydride)

CBDA: 1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride

PMDA: pyromellitic acid dianhydride

(Diamine)

3AMPDA: 3,5-diamino-N- (pyridin-3-ylmethyl) benzamine

3APIDA: Synthesis of N- (3- (1H-imidazol-1-yl) propyl-3,5-diaminobenzamide

DA-5MG: 1,5-bis (4-aminophenoxy) pentane

DA-3MG: 1,3-bis (4-aminophenoxy) propane

DA-2MG: 1,2-bis (4-aminophenoxy) ethane

APC18: 1,3-Diamino-4-octadecyloxybenzene

APC16: 1,3-Diamino-4-hexadecyloxybenzene

p-PDA: p-phenylenediamine

DDM: diaminodiphenylmethane

(Organic solvent)

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

? -BL:? -butyl lactone

[Chemical Formula 15]

(Example 1)

4.56 g (23.28 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 1.74 g (7.19 mmol) of 3AMPDA as a diamine component, 3.77 g (13.17 mmol) of DA-5MG and 1.35 g ) Were weighed and reacted in 83.76 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-1). This polyamic acid had a number average molecular weight of 13,725 and a weight average molecular weight of 32,368.

Subsequently, 45.74 g of the polyamic acid solution (PAA-1) was diluted with 22.93 g of NMP and 17.17 g of BC and mixed to obtain a liquid crystal alignment of 6 mass% in solid content, 26 mass% in NMP and 20 mass% in BC (L-1) was prepared.

(Example 2)

4.74 g (24.17 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 1.82 g (7.50 mmol) of 3AMPDA as a diamine component, 3.55 g (12.40 mmol) of DA-3MG and 1.41 g (3.75 mmol) Was weighed and reacted in 84.24 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-2). This polyamic acid had a number average molecular weight of 12,889 and a weight average molecular weight of 32,973.

Subsequently, 33.37 g of the polyamic acid solution (PAA-2) was diluted with 9.72 g of NMP and 10.77 g of BC and mixed to obtain a liquid crystal alignment of 7% by mass of solid content, 18% by mass of NMP and 20% (L-2) was prepared.

(Example 3)

5.11 g (26.05 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 1.96 g (8.09 mmol) of 3AMPDA as a diamine component, 4.63 g (16.17 mmol) of DA-5MG and 0.94 g (2.70 mmol) Were weighed and reacted in 92.18 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-3). This polyamic acid had a number average molecular weight of 10,554 and a weight average molecular weight of 27,445.

Subsequently, 49.18 g of the polyamic acid solution (PAA-3) was diluted with 26.36 g of NMP and 18.89 g of BC and mixed to obtain a liquid crystal alignment of 6 mass% in solid content, 28 mass% in NMP and 20 mass% in BC (L-3) was prepared.

(Example 4)

4.54 g (23.15 mmol) of CBDA, 1.89 g (7.31 mmol) of 3APIDA as a diamine component, 3.78 g (13.20 mmol) of DA-5MG and 1.36 g (3.60 mmol) of APC18 as a tetracarboxylic acid dianhydride component, Were weighed and reacted in 84.66 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-4). This polyamic acid had a number average molecular weight of 10,082 and a weight average molecular weight of 21,427.

Subsequently, 49.66 g of the polyamic acid solution (PAA-54) was diluted with 25.82 g of NMP and 18.87 g of BC and mixed to obtain a liquid crystal alignment of 6 mass% in solid content, 27 mass% in NMP and 20 mass% in BC (L-4) was prepared.

(Example 5)

2.61 g (11.98 mmol) of PMDA and 2.20 g (11.20 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 1.74 g (7.20 mmol) of 3AMPDA as diamine component and 3.78 g (13.20 mmol) of DA- And 1.36 g (3.60 mmol) of APC18 were weighed and reacted in 85.36 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-5). This polyamic acid had a number average molecular weight of 12,510 and a weight average molecular weight of 28,289.

Subsequently, 23.36 g of the polyamic acid solution (PAA-5) was diluted with 12.80 g of NMP and 9.00 g of BC to obtain a liquid crystal aligning agent (L) having a solid content of 6 mass%, NMP of 28 mass% and BC of 20 mass% -5) was prepared.

(Example 6)

(9.81 g, 0.050 mol), PMDA (10.25 g, 0.047 mol) and DDM (19.83 g, 0.0060 mol) as a diamine component were weighed as a tetracarboxylic acid dianhydride component and 113.00 g , And 113.00 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-6). This polyamic acid had a number average molecular weight of 20,863 and a weight average molecular weight of 57,892.

Subsequently, 198.97 g of the polyamic acid solution (PAA-6) was diluted with 204.23 g of? -BL, 14.63 g of NMP and 73.74 g of BC and mixed to obtain a solution having a solid content of 6% by mass, To prepare a liquid crystal aligning agent (L-6) having 20 mass% of NMP and 15 mass% of BC.

(Example 7)

The liquid crystal aligning agent (L-1) prepared in Example 1 and the liquid crystal aligning agent (L-6) prepared in Example 6 were mixed in a weight ratio of 20:80 and stirred at room temperature for 1 hour to obtain a liquid crystal aligning agent -7).

(Example 8)

The liquid crystal aligning agent (L-4) prepared in Example 4 and the liquid crystal aligning agent (L-6) prepared in Example 6 were mixed in a weight ratio of 20:80 and stirred at room temperature for 1 hour to obtain a liquid crystal aligning agent -8).

(Comparative Example 1)

4.71 g (24.03 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 1.80 g (7.44 mmol) of 3AMPDA as a diamine component, 3.35 g (11.90 mmol) of DA-2MG and 1.41 g (3.75 mmol) Was weighed and reacted in 82.83 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-7). This polyamic acid had a number average molecular weight of 10,961 and a weight average molecular weight of 24,492.

Subsequently, 30.38 g of the polyamic acid solution (PAA-7) was diluted with 15.80 g of NMP and 11.54 g of BC and mixed to obtain a liquid crystal alignment of 6 mass% in solid content, 27 mass% in NMP and 20 mass% in BC (L-9) was prepared.

(Comparative Example 2)

5.03 g (23.08 mmol) of PMDA as a tetracarboxylic acid dianhydride component, 1.74 g (7.20 mmol) of 3AMPDA as a diamine component, 3.78 g (13.20 mmol) of DA-5MG and 1.36 g Were weighed and reacted in 83.76 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-8). The polyamic acid had a number average molecular weight of 12,020 and a weight average molecular weight of 26,924.

Subsequently, 19.65 g of the polyamic acid solution (PAA-8) was diluted with 9.95 g of NMP and 7.40 g of BC and mixed to obtain a liquid crystal alignment of 6% by mass of solid content, 27% by mass of NMP and 20% (L-10) was prepared.

(Comparative Example 3)

5.49 g (27.79 mmol) of CBDA as a tetracarboxylic acid dianhydride component, 2.92 g (27.01 mmol) of p-PDA as a diamine component and 1.05 g (3.01 mmol) of APC16 were weighed and, in 84.91 g of NMP, And reacted at room temperature for 3 hours to obtain a polyamic acid solution (PAA-9). This polyamic acid had a number average molecular weight of 16,868 and a weight average molecular weight of 45,436.

Subsequently, 39.85 g of the polyamic acid solution (PAA-9) was diluted with 12.34 g of NMP and 14.01 g of BC and mixed to obtain a liquid crystal alignment of 6% by mass of solid content, 74% by mass of NMP and 20% by mass of BC (L-11) was prepared.

&Lt; Measurement of molecular weight &

The molecular weight of the polyamic acid obtained by the polymerization reaction was measured by a GPC (room temperature gel permeation chromatography) apparatus. That is, the number average molecular weight and the weight average molecular weight were calculated as polyethylene glycol and polyethylene oxide conversion values.

GPC apparatus: manufactured by Shodex Corp. (GPC-101)

Column: manufactured by Shodex Corp. (serial of KD803 and KD805)

Column temperature: 50 ° C

Eluent: 30 mmol / l (liter) of N, N-dimethylformamide (lithium bromide-hydrate (LiBr.H ₂ O) as an additive), 30 mmol / 10 ml / l of hydrofuran (THF)

Flow rate: 1.0 ml / min

Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, and 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight about 12,000, 4,000, and 1,000 by Polymer Laborato).

&Lt; Production of liquid crystal cell &

For the liquid crystal aligning agents prepared in Examples 1 to 5, 7 and 8 and Comparative Examples 1 to 3, a liquid crystal cell was produced as follows.

The liquid crystal aligning agent was spin-coated on a glass substrate having a transparent electrode formed thereon, dried on a hot plate at 70 占 폚 for 70 seconds, and then baked on a hot plate at 210 占 폚 for 10 minutes to form a 100 nm thick coating film. This coated film was also rubbed with a rubbing device having a film roll diameter of 120 mm using a rayon cloth under the conditions of a roll revolution rate of 1000 rpm, a roll advancing speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate on which a liquid crystal alignment film was formed. Next, two substrates on which liquid crystal alignment films were formed were prepared, spacers with a size of 6 mu m were sprayed on the liquid crystal alignment film surfaces, and a sealing agent was printed thereon. Faced with the rubbing direction being directly opposite, the sealing agent was cured to prepare empty cells. Liquid crystal MLC-2003 (manufactured by Merck Japan Co.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

Evaluation of the orientation of the liquid crystal alignment film formed using each liquid crystal aligning agent and measurement and evaluation of the voltage holding ratio of the liquid crystal cell having the liquid crystal alignment film were carried out as follows.

As a verification test of the orientation property, rubbing was carried out under the condition that the roll revolution was 300 rpm and the indentation amount was changed to 0.15 mm and observed with naked eyes. The evaluation was carried out as follows.

◎: No flow observed.

○: Flow is slightly observed.

X: 10 or more flows are observed.

&Lt; Measurement of voltage holding ratio (VHR) >

The voltage holding ratio of the manufactured twisted nematic liquid crystal cell was measured by applying a voltage of 4 V for 60 seconds at a temperature of 90 캜 and measuring the voltage after 166.7 ms to calculate the voltage holding ratio Respectively. VHR-1 voltage maintenance ratio measuring apparatus manufactured by Toyo Technica Co., Ltd. was used for measurement of the voltage holding ratio.

Table 4 shows the liquid crystal aligning agents obtained in Examples 1 to 5, 7 and 8, and Comparative Examples 1 to 3, and the evaluation results of the alignment properties of the liquid crystal alignment films produced using the liquid crystal aligning agents and the twist The measurement results of the voltage holding ratio of the nematic liquid crystal cell are summarized and shown.

As can be seen from Table 4, the liquid crystal cell obtained using the liquid crystal aligning agent of the present invention has both excellent liquid crystal alignability and voltage maintaining ratio characteristics. On the other hand, in Comparative Example 1 using a diamine having n = 2 in the diamine of the formula (2), the voltage maintaining ratio characteristics were good, but the liquid crystal alignability was bad. In Comparative Example 2 using an aromatic acid dianhydride, the liquid crystal display characteristics were good, but the voltage maintaining ratio characteristics were extremely poor. Comparative Example 3, which did not use a diamine corresponding to the formula (1) or a diamine corresponding to the formula (2), had certain characteristics or bad results.

Industrial availability

The liquid crystal display device manufactured using the liquid crystal aligning agent containing the polyamic acid of the present invention is excellent in voltage holding property and liquid crystal alignment property and can be preferably used for a liquid crystal television with high precision on a large screen.

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2012-008264 filed on January 18, 2012 are hereby incorporated herein by reference and the disclosure of the specification of the present invention.

Claims

A polyamic acid obtained by reacting a diamine component containing a diamine compound of the following formulas (1) and (2) and a tetracarboxylic acid dianhydride component containing a tetracarboxylic acid dianhydride having an alicyclic structure or aliphatic structure, Containing liquid crystal aligning agent.
[Chemical Formula 1]

(In the formula (1), X ₁ Is at least one kind of divalent organic group selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, -NQ ¹ CO-, -CH ₂ O-, and -OCO-, Q ¹ Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. X ₂ Is at least one kind of divalent organic group selected from the group consisting of a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group. X ₃ Is a single bond, or ^{-O-, -NQ 2 -, -CONQ 2} -, -NQ 2 CO-, -COO-, -OCO-, and _{-O (CH 2) m - (} m is an integer from 1 to 5 , And Q < ² > is at least one kind of divalent organic group selected from the group consisting of Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. X ₄ Is a nitrogen-containing aromatic heterocyclic group, and n is an integer of 1 to 4.
And n in the formula (2) is an integer of 3 to 10.)

The method according to claim 1,
Wherein the polyamic acid has a weight average molecular weight of 5,000 to 1,000,000.

The method according to claim 1,
X ₁ in the formula (1) is at least one member selected from the group consisting of -O-, -NQ ¹ -, -CONQ ¹ -, and -NQ ¹ CO-, X ₂ is a single bond, A straight chain alkylene group and a benzene ring, X ₃ is at least one member selected from the group consisting of a single bond, -OCO-, and -OCH ₂ -, X ₄ is imidazole A ring, a pyridine ring, and a pyrimidine ring, and n is an integer of 1 or 2. 2. The liquid crystal aligning agent according to claim 1,

The method according to claim 1,
A liquid crystal aligning agent wherein the diamine of the formula (1) is 5 to 50 mol% of the total diamine component.

The method according to claim 1,
A liquid crystal aligning agent wherein X ₄ in the formula (1) is a pyridine ring or an imidazole ring.

The method according to claim 1,
Wherein the diamine of the formula (2) is 10 to 50 mol% of the total diamine component.

The method according to claim 1,
Wherein n in the formula (2) is from 3 to 8.

The method according to claim 1,
Wherein the tetracarboxylic acid dianhydride component further contains an aromatic tetracarboxylic acid dianhydride.

A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of claims 1 to 8.

10. The method of claim 9,
Wherein the liquid crystal aligning agent contains 80 to 99 mass% of an organic solvent based on the entire liquid crystal aligning agent (100 mass%).

11. The method of claim 10,
Wherein the organic solvent is selected from the group consisting of N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2- Methylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, gamma -butyrolactone, 1,3-dimethyl-imidazolidinone, ethylamylketone, methylnonylketone, methyl At least one selected from the group consisting of ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, and 4-hydroxy- Liquid crystal alignment film.

A liquid crystal display element comprising the liquid crystal alignment film according to claim 9.