WO2011078132A1

WO2011078132A1 - Liquid crystal-aligning agent, liquid crystal alignment film, and liquid crystal display element using same

Info

Publication number: WO2011078132A1
Application number: PCT/JP2010/072928
Authority: WO
Inventors: 和義保坂; 浩北; 雅章片山; 幸司園山
Original assignee: 日産化学工業株式会社
Priority date: 2009-12-25
Filing date: 2010-12-20
Publication date: 2011-06-30
Also published as: CN102667594A; JP5614412B2; KR101759753B1; CN102667594B; TWI494374B; TW201137037A; JPWO2011078132A1; KR20120123284A

Abstract

A liquid crystal-aligning agent comprising at least one kind of a polymer selected from the group consisting of a polyamic acid, which is obtained by reacting a diamine component containing a diamine compound represented by formula [1] with a tetracarboxylic dianhydride, and a polyimide obtained by the dewatering cyclization of said polyamic acid. In formula [1], X₁ represents -O-, -NH-, -N(CH₃)-, -CONH-, -NHCO-, -CH₂O-, -COO-, -OCO-, -CON(CH₃)- or -N(CH₃)CO-; X₂ represents a single bond or an aliphatic hydrocarbon group, a non-aromatic cyclic hydrocarbon group or an aromatic hydrocarbon group, each group having 1 to 20 carbon atoms; X₃ represents a single bond, -O-, -NH-, -N(CH₃)-, -CONH-, -NHCO-, -COO-, -OCO-, -CON(CH₃)-, -N(CH₃)CO- or -O(CH₂)_m- (wherein m is an integer of 1 to 5); X₄ represents an organic group having 1 to 20 carbon atoms; and n is an integer of 1 to 4.

Description

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element using the same

The present invention relates to a liquid crystal alignment treatment agent, a liquid crystal alignment film, and a liquid crystal display element used for a liquid crystal display element.

In a liquid crystal display element, a liquid crystal alignment film plays a role of aligning liquid crystals in a certain direction. Currently, the main liquid crystal alignment film used industrially is formed by applying a polyimide-based liquid crystal alignment treatment agent comprising a polyimide precursor, polyamic acid (also referred to as polyamic acid) or a polyimide solution, onto a substrate. It is made by filming. When the liquid crystal is aligned in parallel or inclined with respect to the substrate surface, a surface stretching process is further performed by rubbing after film formation. As an alternative to the rubbing treatment, a method using an anisotropic photochemical reaction by irradiation with polarized ultraviolet rays has been proposed, and in recent years, studies for industrialization have been performed.

The liquid crystal alignment film is also used to control the angle of the liquid crystal with respect to the substrate, that is, the pretilt angle of the liquid crystal. However, as the liquid crystal display element becomes more sophisticated and its range of use expands year by year, Not only can a predetermined pretilt angle be obtained, but also the stability of the pretilt angle has become increasingly important.

From the viewpoint of the stability of the pretilt angle, a compound having two or more epoxy groups in the molecule is used as a polyimide-based liquid crystal for the purpose of obtaining a constant pretilt angle regardless of the rubbing conditions in the manufacturing process of the liquid crystal alignment film. It has been proposed to be included in an alignment treatment agent (see, for example, Patent Document 1).

Also, in the manufacturing process of the liquid crystal display element, in order to improve the alignment uniformity of the liquid crystal, the liquid crystal is sometimes isotropically treated by heat treatment after sealing the liquid crystal. However, when the stability of the pretilt angle is low, there arises a problem that a pretilt angle having a target size cannot be obtained after this isotropic processing or the pretilt angle varies. In particular, liquid crystal display elements that use a backlight that generates a large amount of heat to obtain high brightness, and liquid crystal display elements that are used in in-vehicle applications, such as car navigation systems and instrument panels, are used in high-temperature environments for long periods of time. Or it may be left unattended. Under such severe conditions, when the pretilt angle is gradually changed, problems such as inability to obtain initial display characteristics or occurrence of unevenness in display occur.

In recent years, large-screen, high-definition liquid crystal televisions have been widely put into practical use, and such liquid crystal display elements are used in harsh usage environments compared to liquid crystal display elements for monitors that mainly display characters and still images. Characteristics that can withstand long-term use are required. Therefore, the liquid crystal alignment film has been required to have higher reliability. In particular, when the voltage holding ratio, which is one of the electrical characteristics, is reduced, line sticking, which is a display defect of the liquid crystal display element, easily occurs, and a highly reliable liquid crystal display element cannot be obtained. Therefore, not only the initial characteristics are good, but also, for example, it is required that the initial characteristics are not easily lowered even after being exposed to a high temperature for a long time.

JP 7-234410 A

The present invention has been made in view of the above circumstances, and the problem thereof is a liquid crystal alignment film that is excellent in stability of a pretilt angle even under a high temperature environment for a long time, and in which a decrease in voltage holding ratio is suppressed, The object is to provide a liquid crystal display element having the liquid crystal alignment film and a liquid crystal alignment treatment agent for forming the liquid crystal alignment film.

As a result of intensive studies, the present inventors have found that a liquid crystal alignment treatment agent containing a polyamic acid using a specific diamine compound as a diamine component and / or a polyimide obtained by imidizing the polyamic acid has the above-mentioned purpose. The present invention has been found to be extremely effective for achieving the present invention, and has been completed. In addition, the said specific diamine compound contains the novel compound which literature has not been described.

That is, the present invention has the following gist.
(1) From the group consisting of a polyamic acid obtained by reacting a diamine component containing the diamine compound represented by the formula [1] with tetracarboxylic dianhydride, and a polyimide obtained by dehydrating and ring-closing the polyamic acid. A liquid crystal aligning agent containing at least one selected polymer.

(In the formula [1], X ₁ is —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON) (CH ₃ ) — or —N (CH ₃ ) CO—, and X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon. X ₃ is a single bond, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH ₃ ) —, —N (CH ₃ ) CO— or —O (CH ₂ ) _m — (m is an integer of 1 to 5), X ₄ represents an organic group having 1 to 20 carbon atoms, and n is 1 It is an integer of ~ 4.)
(2) The liquid crystal aligning agent according to the above (1), wherein X _{2 in the} formula [1] is a single bond or an alkylene group having 1 to 5 carbon atoms.
(3) The liquid crystal aligning agent according to the above (1) or (2), wherein X _{4 in the} formula [1] is an alkyl group having 1 to 5 carbon atoms.
(4) In the formula (1), X ₁ is —O—, —CONH—, or —COO—, X ₃ is a single bond or —O—, and n is 1, 3) The liquid-crystal aligning agent in any one of.
(5) The liquid crystal aligning agent according to any one of (1) to (4), wherein 5 to 80 mol% in the diamine component is a diamine compound represented by the formula [1].
(6) A liquid crystal alignment film obtained using the liquid crystal aligning agent according to any one of (1) to (5).
(7) A liquid crystal display device having the liquid crystal alignment film according to (6).
(8) A diamine compound represented by the following formula [1].

(In the formula [1], X ₁ is —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON) (CH ₃ ) — or —N (CH ₃ ) CO—, and X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon. X ₃ is a single bond, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH ₃ ) —, —N (CH ₃ ) CO— or —O (CH ₂ ) _m — (m is an integer of 1 to 5), X ₄ represents an organic group having 1 to 20 carbon atoms, and n is 1 It is an integer of ~ 4.)
(9) Polyamic acid obtained by reacting a diamine component containing the diamine compound represented by the formula [1] described in (8) above with tetracarboxylic dianhydride, or dehydrating and ring-closing the polyamic acid. Obtained polyimide.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention has excellent pretilt angle stability even under a high temperature environment for a long time, and can suppress a decrease in voltage holding ratio. Therefore, the liquid crystal display element having the liquid crystal alignment film is excellent in reliability.
Moreover, according to this invention, the novel diamine compound useful as raw materials, such as a liquid-crystal aligning agent, is provided.

In the liquid crystal aligning agent of the present invention, a diamine compound having an oxetane group represented by the following formula [1] (hereinafter also referred to as a specific diamine compound) is used.

(In the formula [1], X ₁ is —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON) (CH ₃ ) — or —N (CH ₃ ) CO—, and X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon. X ₃ is a single bond, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH ₃ ) —, —N (CH ₃ ) CO— or —O (CH ₂ ) _m — (m is an integer of 1 to 5), X ₄ represents an organic group having 1 to 20 carbon atoms, and n is 1 It is an integer of ~ 4.)

In the present invention, the polyamic acid obtained by the reaction of a diamine component containing a specific diamine compound and tetracarboxylic dianhydride, and the polyimide obtained by dehydrating and ring-closing the polyamic acid are collectively referred to as a polymer. There is also. The polymer obtained by using the specific diamine compound in the present invention has a side chain of the following formula [1a].

(In the formula [1a], X ₁ , X ₂ , X ₃ and X ₄ are the same as defined in the above formula [1].)
The oxetane group present at the end of the side chain of the formula [1a] reacts with a carboxyl group and / or a hydroxyl group under heating. Two oxetane groups also undergo addition polymerization with each other. These reactions form a structure in which a plurality of polymers are crosslinked. Since the oxetane group has higher nucleophilicity than the epoxy group, the reaction efficiency is high. Therefore, the plurality of polymers having the side chain of the formula [1a] are more easily cross-linked, and a liquid crystal alignment film having a structure with a high cross-linking density is easily formed. Furthermore, since the oxetane group has a four-membered ring structure, when it reacts with a carboxyl group and / or a hydroxyl group, it contains one more methylene group at the binding site than an epoxy group that has a three-membered ring structure. In addition, because of the oxetane group present at the end of the side chain of the formula [1a], it is easy to obtain a liquid crystal alignment film having a high crosslink density structure and a high elongation and toughness. It is presumed that this makes it difficult for the stretchability of the polymer to be hindered during rubbing and to prevent scratches and scraping.
Furthermore, the oxetane group present at the end of the side chain of the formula [1a] can efficiently promote the crosslinking reaction, thereby reducing the characteristics of the liquid crystal display element when the crosslinking compound is added. There is no residue of unreacted crosslinkable compounds that cause it.

From the above, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention is more stable against heat of the pretilt angle than the liquid crystal alignment film containing no crosslinkable compound or the liquid crystal alignment film added with the crosslinkable compound. Thus, the decrease in voltage holding ratio can be suppressed in a high temperature environment. Therefore, line sticking, which is one of display defects, hardly occurs, so that a liquid crystal display element with excellent reliability can be obtained.

<Specific diamine compound>
The specific diamine compound of the present invention is a diamine compound having an oxetane group represented by the following formula [1].

In the formula [1], X ₁ represents —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON ( A divalent organic group selected from CH ₃ ) — and —N (CH ₃ ) CO—. Among them, —O—, —NH—, —CONH—, —NHCO—, —CON (CH ₃ ) —, —CH ₂ O—, —COO—, or —OCO— is easy to synthesize diamine compounds. preferable. More preferred is —O—, —CONH—, —CON (CH ₃ ) —, —CH ₂ O—, or —COO—. More preferred is —O—, —CONH—, or —COO—, and particularly preferred is —COO—.
In the formula [1], X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear or branched. Moreover, you may have an unsaturated bond.

Specific examples of the non-aromatic hydrocarbon group include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cycloundecane ring, cyclododecane ring, cyclotridecane ring. Decane ring, cyclotetradecane ring, cyclopentadecane ring, cyclohexadecane ring, cycloheptadecane ring, cyclooctadecane ring, cyclononadecane ring, cycloicosane ring, tricycloeicosane ring, tricyclodecosan ring, bicycloheptane ring, decahydronaphthalene ring , Norbornene ring, 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 phenalene ring.

X ₂ is preferably a single bond, an 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, Adamantane ring, benzene ring, naphthalene ring, tetrahydronaphthalene ring, fluorene ring or anthracene ring, more preferably a single bond, an alkyl group having 1 to 10 carbon atoms, an unsaturated alkyl group having 1 to 10 carbon atoms, cyclohexane A ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a fluorene ring, or an anthracene ring, and more preferably a single bond, an alkylene group having 1 to 5 carbon atoms, or a benzene ring. Most preferably, it is a single bond or an alkylene group having 1 to 5 carbon atoms.

In the formula [1], X ₃ represents a single bond, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH ₃ ). —, —N (CH ₃ ) CO—, —O (CH ₂ ) _m — (m is an integer of 1 to 5). Preferably, a single bond, —O—, —NH—, —CONH—, —NHCO—, —COO—, —OCO—, or —O (CH ₂ ) _m — (m is an integer of 1 to 5) More preferably, a single bond, —O—, —NH—, —CONH—, —NHCO—, —COO—, —OCO—, or —O (CH ₂ ) _m — (m is 1 to 5) It is an integer), more preferably a single bond, —O—, —CONH—, or —COO—, and particularly preferably a single bond or —O—.

In the formula [1], X ₄ represents an organic group having 1 to 20 carbon atoms, and the organic group may contain a hetero atom (N, O, S, Si). An alkyl group having 1 to 10 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable.
In the formula [1], n is an integer of 1 to 4. Preferably, it is 1 to 3 and more preferably 1, from the viewpoint of reactivity with tetracarboxylic dianhydride.

The bonding position of the two amino groups (—NH ₂ ) in the formula [1] is not limited. Specifically, with respect to the linking group (X ₁ ) of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring Position, 3, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine compound, the positions 2, 4 or 3, 5 are more preferable.
It is particularly preferred that X _{1 in the} formula [1] is —O—, —CONH—, or —COO—, X ₃ is a single bond or —O—, and n is 1.

Further, X ₁ in the formula [1] is —O—, —CONH—, or —COO—, X ₂ is a single bond or an alkylene group having 1 to 5 carbon atoms, and X ₃ is a single bond, or It is particularly preferred that —O—, X ₄ is an alkyl group having 1 to 5 carbon atoms, and n is 1.
Preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are as shown in Table 1 below.

<Method for synthesizing specific diamine compound>
The method for producing the specific diamine compound represented by the formula [1] of the present invention is not particularly limited, but preferred methods include the following methods.
The specific diamine compound of the present invention can be obtained by synthesizing a dinitro compound represented by the following formula [2], further reducing the nitro group, and converting it to an amino group.

_{_{_{(X 1, X 2, X}}} 3 in the formula [2], _{X 4} and n are _{_{_{X 1, X 2, X 3}}} , the same meanings as defined in _{X 4} and n in the formula [1].)
The method for reducing the dinitro group is not particularly limited, and usually palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as a catalyst, ethyl acetate, toluene, tetrahydrofuran, dioxane, There is a method in which hydrogen gas, hydrazine, hydrogen chloride, or the like is used in a solvent such as an alcohol solvent.
The dinitro compound of the formula [2] can be obtained by a method in which —X ₂ —X ₃ is bonded to dinitrobenzene via X ₁ .

X ₁ is —O— (ether bond), —NH— (amino bond), —N (CH ₃ ) — (methylated amino bond), —CONH— (amide bond), —NHCO— (reverse amide bond), —CH ₂ O— (methylene ether bond), —COO— (ester bond), —OCO— (reverse ester bond), —CON (CH ₃ ) — (N-methylated amide bond), and —N (CH ₃ ) CO— (N-methylated reverse amide bond). These linking groups can be formed by ordinary organic synthetic techniques.

For example, when X ₁ is an ether or methylene ether bond, a corresponding dinitro group-containing halogen derivative is reacted with a hydroxyl group derivative containing X ₂ , X ₃ and X ₄ in the presence of an alkali, or a dinitro group-containing hydroxyl group derivative And a halogen-substituted derivative containing an oxetane group having X ₂ , X ₃ and X ₄ in the presence of an alkali.

In the case of an amino bond, a method of reacting a corresponding dinitro group-containing halogen derivative with an amino group-substituted derivative containing an oxetane group having X ₂ , X ₃ and X ₄ in the presence of an alkali can be mentioned.
Examples of the amide bond include a method of reacting a corresponding dinitro group-containing acid chloride and an amino group-substituted product containing an oxetane group having X ₂ , X ₃ and X ₄ in the presence of an alkali.

In the case of a reverse amide bond, a method in which a corresponding dinitro group-containing amino group-substituted product and an acid chloride containing an oxetane group having X ₂ , X ₃ and X ₄ are reacted in the presence of an alkali can be mentioned.
In the case of an ester bond, a method in which the corresponding dinitro group-containing acid chloride is reacted with a hydroxyl group-substituted derivative containing an oxetane group having X ₂ , X ₃ and X ₄ in the presence of an alkali can be mentioned.
In the case of a reverse ester bond, a method of reacting a corresponding dinitro group-containing hydroxyl group derivative with an acid chloride containing an oxetane group having X ₂ , X ₃ and X ₄ in the presence of an alkali can be mentioned.

Specific examples of dinitro group-containing halogen derivatives and dinitro group-containing derivatives include 3,5-dinitrochlorobenzene, 2,4-dinitrochlorobenzene, 2,4-dinitrofluorobenzene, 3,5-dinitrobenzoic acid chloride, 3,5 -Dinitrobenzoic acid, 2,4-dinitrobenzoic acid chloride, 2,4-dinitrobenzoic acid, 3,5-dinitrobenzyl chloride, 2,4-dinitrobenzyl chloride, 3,5-dinitrobenzyl alcohol, 2,4- Dinitrobenzyl alcohol, 2,4-dinitroaniline, 3,5-dinitroaniline, 2,6-dinitroaniline, 2,4-dinitrophenol, 2,5-dinitrophenol, 2,6-dinitrophenol, 2,4- And dinitrophenylacetic acid. In consideration of availability of raw materials and reaction, one or more kinds can be selected and used.

<Other diamine compounds>
In this invention, unless the effect of this invention is impaired, other diamine compounds other than a specific diamine compound can be used together as a diamine component. Specific examples are given below.

p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl 3,3′-difluoro-4,4′-biphenyl, 3,3′-trifluoromethyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2 '-Diaminobiphenyl, 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 ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldi Aniline, 3,3'-sulfonyldianiline, bis ( -Aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4'-thiodianiline, 3,3'-thiodianiline 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'- Diaminodiphenyl) amine, N-methyl (3,3′-diaminodiphenyl) amine, N-methyl (3,4′-diaminodiphenyl) amine, N-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'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diamino Naphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4 -Aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis (4 aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl-4- Minophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4 -Aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 '-[1,3-phenylenebis (methylene)] dianiline, 3,4'-[1,4-phenylenebis (methylene)] dianiline, 3,4 '-[1,3-phenylenebis (methylene) )] Dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] dianiline, 1,4-phenylenebi [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [( 3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1,3 -Phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N ′-(1,3-phen Nylene) bis (4-aminobenzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phenylene) bis (3-aminobenzamide), N, N'-bis (4-aminophenyl) terephthalamide, N, N'-bis (3-aminophenyl) terephthalamide, N, N'-bis (4-aminophenyl) isophthalamide, N, N'- Bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2,2′-bis [4- (4- Aminophenoxy) phenyl] propane, 2,2′-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2′-bis (4-aminopheny) ) Hexafluoropropane, 2,2′-bis (3-aminophenyl) hexafluoropropane, 2,2′-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2′-bis (4- Aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 3,5-diaminobenzoic acid, 2,5-diamino Benzoic acid, 1,3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3- Aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) ) Hexane, 1,6-bis (3-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4 -Aminophenoxy) octane, 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- ( 4-aminophenoxy) decane, 1,10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4- Aromatic diamines such as aminophenoxy) dodecane and 1,12- (3-aminophenoxy) dodecane, bis (4-aminocyclohexyl) methane, bis (4-amino -3-cyclohexyl) methane and other alicyclic diamines, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, Aliphatic diamines such as 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane.

Examples of the diamine include a diamine having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent composed of these in the diamine side chain. Examples thereof include diamines represented by DA1] to [DA32].

(In Formula [DA1] to Formula [DA5], R ₁ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

(In the formulas [DA6] to [DA11], R ₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. R ₃ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

(In Formula [DA12] and Formula [DA13], R ₄ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ₅ represents the number of carbon atoms. 1 to 22 alkyl groups, alkoxy groups, fluorine-containing alkyl groups or fluorine-containing alkoxy groups.)

(In the formulas [DA14] to [DA16], R ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — OCH ₂ — or —CH ₂ —, and R ₇ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

(In Formula [DA17] and Formula [DA18], R ₈ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — OCH ₂ —, —CH ₂ —, —O—, or —NH—, wherein R ₉ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group .)

(In Formula [DA19] and Formula [DA20], R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer.)

(In Formula [DA21] and Formula [DA22], R ₁₁ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer.)

In addition, diaminosiloxanes represented by the following formula [DA33] can also be exemplified.

(In the formula [DA33], p is an integer of 1 to 10)

Furthermore, a diamine of the following formula [DA34] can be mentioned.

(In the formula [DA34], A ₄ represents an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₃ represents a 1,4-cyclohexylene group or 1,4-phenylene. A ₂ is an oxygen atom or —COO— * (where a bond marked with “*” is bonded to A ₃ ), and A ₁ is an oxygen atom or —COO— * (wherein And a bond marked with “*” binds to (CH ₂ ) a2.) A ₁ is 0 or an integer of 1, a 2 is an integer of 2 to 10, and a 3 is 0. Or an integer of 1.)

The above-mentioned other diamine compounds can be used alone or in combination of two or more depending on the properties such as liquid crystal alignment properties, voltage holding properties, and accumulated charges when the liquid crystal alignment film is used.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride used in the present invention is not particularly limited. Specific examples are given below.

Pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7 -Anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4-biphenyltetracarboxylic acid, bis ( 3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2 , 2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) pro Bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4 -Dicarboxyphenyl) pyridine, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4- Cyclobutanetetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic Acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobut Tetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, bicyclo [4,3,0] nonane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0 ] Decane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] decane-2,4,8,10-tetracarboxylic acid, tricyclo [6.3.0.0 <2,6 >] Undecane- 3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetra Hydrinaphthalene-1,2-dicarboxylic acid, bicyclo [2,2,2] oct-7-ene-2,3,5,6-tetracarboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3 -Methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodeca-4,5,9,10-tetracarboxylic acid, 3,5, Examples thereof include 6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic acid and 1,2,4,5-cyclohexanetetracarboxylic acid.

The tetracarboxylic dianhydride can be used singly or in combination of two or more according to properties such as liquid crystal alignment properties, voltage holding properties, and accumulated charges when formed into a liquid crystal alignment film.

<Polymer>
As described above, the polymer of the present invention is a polyamic acid using a specific diamine compound as a raw material or a polyimide obtained by dehydrating and ring-closing the polyamic acid.
In the liquid crystal alignment film obtained from the polymer of the present invention, the stability of the pretilt angle to heat increases as the content ratio of the specific diamine compound in the diamine component increases.

For the purpose of enhancing the above properties, it is preferable that 1 mol% or more of the diamine component is a specific diamine compound. Furthermore, it is preferable that 5 mol% or more of a diamine component is a specific diamine compound, More preferably, it is 10 mol% or more. Moreover, although 100 mol% of a diamine component may be a specific diamine compound, from the viewpoint of uniform coatability when applying a liquid crystal aligning agent, the specific diamine compound is preferably 80 mol% or less of the diamine component. Preferably it is 40 mol% or less.

In obtaining the polyamic acid of the present invention by the reaction of the diamine component and tetracarboxylic dianhydride, a known synthesis method can be used. In general, tetracarboxylic dianhydride and diamine are reacted in an organic solvent. The reaction of tetracarboxylic dianhydride and diamine is advantageous in that it proceeds relatively easily in an organic solvent and no by-product is generated.

The organic solvent used for the reaction between tetracarboxylic dianhydride and diamine is not particularly limited as long as the produced polyamic acid can be dissolved. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, Methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, 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, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, Dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n- Pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3 -Methyl methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid 3-methoxy propionic acid propyl, 3-methoxy propionic acid butyl, diglyme, and the like 4-hydroxy-4-methyl-2-pentanone. These may be used alone or in combination. Further, even a solvent that does not dissolve the polyamic acid may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate. Moreover, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid, it is preferable to use a dehydrated and dried organic solvent.

When reacting tetracarboxylic dianhydride and diamine component in an organic solvent, the solution in which the diamine is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is dispersed as it is or in the organic solvent. Alternatively, a method of adding after dissolving, a method of adding diamine to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, a method of adding tetracarboxylic dianhydride and diamine alternately, etc. Any of these methods may be used. In addition, when the tetracarboxylic dianhydride or diamine component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed to form a high molecular weight product.

The temperature at which the tetracarboxylic dianhydride reacts with the diamine component can be selected from -20 ° C to 150 ° C, but is preferably in the range of -5 ° C to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, the content is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, 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 tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.

The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing the above polyamic acid, and is useful as a polymer for obtaining a liquid crystal alignment film.
In the polyimide of the present invention, the dehydration cyclization rate (imidization rate) of the amic acid group is not necessarily 100%, and can be adjusted, for example, in the range of 45 to 85% depending on the application and purpose. .
Examples of the method for imidizing the polyamic acid include thermal imidization in which the polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution.
The temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and it is preferable to carry out while removing water generated by the imidation reaction from the system.

The catalytic imidation of the polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to the polyamic acid solution and stirring at -20 to 250 ° C, preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amido acid group. Is double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated. The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

When the produced polyamic acid or polyimide is recovered from the polyamic acid or polyimide reaction solution, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated in a poor solvent and collected by filtration can be dried by normal temperature or reduced pressure at room temperature or by heating. In addition, when the polymer collected by precipitation is redissolved in an organic solvent and reprecipitation and collection is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

The molecular weight of the polyamic acid and the polyimide contained in the liquid crystal alignment treatment agent of the present invention is determined by considering the strength of the coating film obtained therefrom, the workability during coating film formation, and the uniformity of the coating film. The weight average molecular weight measured by Permeation (Chromatography) method is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention is a coating liquid for forming a liquid crystal aligning film, and is a solution which the resin component for forming a resin film melt | dissolved in the organic solvent. Here, the said resin component is a resin component containing at least 1 type of polymer chosen from the polymer of this invention mentioned above. In that case, the content of the resin component is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass.

In the present invention, all of the above resin components may be polymers used in the present invention, and other polymers may be mixed with the polymer of the present invention. In that case, the content of the other polymer in the resin component is 0.5 to 15% by mass, preferably 1 to 10% by mass.

Examples of such other polymers include polyamic acid or polyimide obtained by using a diamine other than the specific diamine compound as a diamine component to be reacted with tetracarboxylic dianhydride.

The organic solvent used for the liquid-crystal aligning agent of this invention will not be specifically limited if it is an organic solvent in which the resin component mentioned above is dissolved.
The liquid crystal aligning agent of this invention may contain components other than the above. Examples thereof include solvents and compounds that improve the film thickness uniformity and surface smoothness when a liquid crystal alignment treatment agent is applied, and compounds that improve the adhesion between the liquid crystal alignment film and the substrate.

Specific examples of the solvent that improves the uniformity of the film thickness and the surface smoothness include the following.
For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoacetate Isopropyl 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, diethylene glycol dimethyl ether, dipro Lenglycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3 -Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl Ether, n-hexane, n-pentane, n-octane, diethyl ether Methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, 3-methoxy Ethyl propionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy- 2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether Ter-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactyl isoamyl ester, etc. have low surface tension A solvent etc. are mentioned.

The solvent for improving the uniformity of the film thickness and the surface smoothness may be used alone or in combination. When the above solvent is used, the amount of the solvent used is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal aligning agent.
Examples of the compound that improves the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant.

More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 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-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene glycol diglycidyl ether, neopentyl 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-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like.

When using a compound to be adhered to these substrates, the amount of the compound used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin component contained in the liquid crystal aligning agent, More preferably, it is 1 to 20 parts by mass. If the amount is less than 0.1 part by mass, the effect of improving the adhesion cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may deteriorate.
In addition to the above, the liquid crystal alignment treatment agent of the present invention is a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film as long as the effects of the present invention are not impaired. May be added.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment treatment agent of the present invention can be used as a liquid crystal alignment film without applying an alignment treatment after being applied and baked on a substrate and then subjected to an alignment treatment by rubbing treatment, light irradiation, or the like. In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

The method for applying the liquid crystal alignment treatment agent is not particularly limited, but industrially, methods such as screen printing, offset printing, flexographic printing, and ink jet are generally used. Other coating methods include dip, roll coater, slit coater, spinner and the like, and these may be used depending on the purpose.

Calcination after applying the liquid crystal aligning agent on the substrate can form a coating film by evaporating the solvent at 50 to 300 ° C., preferably 80 to 250 ° C., by a heating means such as a hot plate. If the thickness of the coating film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. Therefore, it is preferably 5 to 300 nm, more preferably 10 to 100 nm. When the liquid crystal is horizontally or tilted, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.

The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.

To give an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, spray spacers on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside. Examples include a method of bonding the other substrate and injecting the liquid crystal under reduced pressure, or a method of sealing the liquid crystal after dropping the liquid crystal on the liquid crystal alignment film surface on which the spacers are dispersed, and the like. . The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.
As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention has excellent reliability and can be suitably used for a large-screen, high-definition liquid crystal television.

The present invention will be described in more detail with reference to the following examples, but is not limited thereto.
“Synthesis of the Specific Diamine Compound of the Present Invention”
<Example 1>
Synthesis of diamine compound (4)

3-methyl-3-oxetaneethanol (2) (14.95 g, 146.4 mmol), triethylamine (16.29 g, 160.1 mmol) and tetrahydrofuran (150 ml) were added to a nitrogen-substituted four-necked flask at room temperature. Thereafter, a solution of 3,5-dinitrobenzoyl chloride (1) (33.70 g, 146.2 mmol) in tetrahydrofuran (40 ml) was added dropwise while maintaining the temperature at 15 ° C. or lower. After completion of the reaction, the reaction solution was poured into 1 L of pure water, and the resulting crystals were filtered and washed with pure water. The crystals were stirred in ethanol (200 ml), filtered and washed with ethanol to obtain compound (3) (white crystals, 36.33 g, yield 84%).
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 9.26 (1H, t, J = 2.0 Hz), 9.16 (1H, dd,
J = 1.2Hz), 4.63-4.50 (4H, m), 4.59 (2H, s), 1.47 (3H, s).
A mixture of compound (3) (30.00 g, 101 mmol) and 5% Pd—C (3 g) in tetrahydrofuran (300 ml) was stirred at room temperature in the presence of hydrogen. After completion of the reaction, the mixture was filtered, and the filtrate was concentrated under reduced pressure. Hexane (200 ml) was added to the resulting crude product and stirred. After stirring, the crystals were filtered and washed with hexane. The obtained crystals were added again in ethanol (100 ml) and stirred, and then the crystals were filtered and washed with ethanol to obtain the diamine compound (4) (white crystals, 21.45 g, yield 90%). Got.
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 6.78 (2H, d, J = 2.4 Hz), 6.18 (1H, t, J = 2.4 Hz), 4.63 (2H, d, J = 6.0 Hz), 4.44 (2H, d, J = 6.0Hz), 4.32 (2H, s), 3.745 (4H, brod), 1.40 (3H, s).

"Synthesis of polyamic acid and polyimide"
In Examples 2 to 9 and Comparative Examples 1 to 4 described below, examples of synthesizing polyamic acid or polyimide are described. Meaning of abbreviations used in each description, measurement of molecular weight of polyamic acid and polyimide, and imidization The rate measurements are as follows. The contents of the polyamic acid and polyimide synthesized in Examples 2 to 9 and Comparative Examples 1 to 4 are summarized in Table 2 and Table 3, respectively.
(Tetracarboxylic dianhydride)
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BODA: bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride

(Specific diamine compound)
Diamine (4): Diamine compound synthesized in Example 1

(Other diamine compounds)
p-PDA: p-phenylenediamine PCH7DAB: 1,3-diamino-4- [4- (trans-4-n-heptylcyclohexyl) phenoxy] benzene PBCH5DAB: 1,3-diamino-4- {4- [ Trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene m-PBCH5DAB: 3,5-diamino- {4- [trans-4- (trans-4-n-pentylcyclohexyl) ) Cyclohexyl] phenyl} benzoate

(Crosslinkable compound)
KK1:

KK2:

(Organic solvent)
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve (Measurement of molecular weight of polyamic acid and polyimide)
The molecular weights of the polyamic acid and the polyimide were measured as follows using a normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Denko KK and a column (KD-803, KD-805) manufactured by Shodex.
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (manufactured by Polymer Laboratories) Molecular weight about 12,000, 4,000, 1,000).

(Measurement of imidization rate)
Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.) and add 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture). The solution was completely dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) manufactured by JEOL Datum. The imidation rate is determined by determining a proton derived from a structure that does not change before and after imidation as a reference proton, and the peak integrated value of this proton and the proton peak derived from the NH group of amic acid that appears near 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value.
Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

<Example 2>
BODA (3.51 g, 14.0 mmol), PCH7DAB (0.89 g, 2.34 mmol), p-PDA (1.77 g, 16.4 mmol), diamine (4) (1.10 g, 4.66 mmol) in NMP (14.4 g), and reacted at 80 ° C. for 5 hours. Then, CBDA (1.84 g, 9.38 mmol) and NMP (12.3 g) were added, and reacted at 40 ° C. for 6 hours to obtain polyamic acid. A solution (concentration 25.4% by mass) of (A) was obtained. The number average molecular weight of this polyamic acid was 23,900, and the weight average molecular weight was 59,500.

<Example 3>
NMP was added to the polyamic acid (A) solution (20.0 g) obtained in the same manner as in Example 2 and diluted to a concentration of 6% by mass. Then, acetic anhydride (2.48 g), pyridine ( 1.90 g) was added and reacted at 80 ° C. for 4 hours. The reaction solution was poured into methanol (300 ml), and the produced precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (B) powder. The imidation ratio of this polyimide was 53%, the number average molecular weight was 21,300, and the weight average molecular weight was 51,200.

<Example 4>
BODA (3.48 g, 13.9 mmol), PCH7DAB (0.44 g, 1.16 mmol), p-PDA (1.63 g, 15.1 mmol), diamine (4) (1.64 g, 6.94 mmol) in NMP (14.6 g), the mixture was reacted at 80 ° C. for 5 hours, CBDA (1.82 g, 9.27 mmol) and NMP (12.7 g) were added, and the mixture was reacted at 40 ° C. for 6 hours. A solution (concentration 24.8% by mass) of (C) was obtained. The number average molecular weight of this polyamic acid was 24,100, and the weight average molecular weight was 59,200.

<Example 5>
NMP was added to a solution (20.2 g) of the polyamic acid (C) obtained in the same manner as in Example 4 to dilute to 6% by mass, and then acetic anhydride (2.50 g), pyridine (1 .95 g) was added and reacted at 80 ° C. for 4 hours. The reaction solution was poured into methanol (300 ml), and the produced precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (D) powder. The imidation ratio of this polyimide was 55%, the number average molecular weight was 22,400, and the weight average molecular weight was 52,500.

<Example 6>
BODA (3.50 g, 14.0 mmol), PCH7DAB (4.44 g, 11.7 mmol), p-PDA (1.01 g, 9.34 mmol), diamine (4) (0.55 g, 2.33 mmol) in NMP (17.5 g), the mixture was reacted at 80 ° C. for 5 hours, CBDA (1.83 g, 9.33 mmol) and NMP (15.9 g) were added, and the mixture was reacted at 40 ° C. for 6 hours. A solution (concentration 25.3% by weight) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6% by mass, acetic anhydride (4.53 g) and pyridine (3.31 g) were added as an imidization catalyst, and the mixture was stirred at 90 ° C. for 3 hours. Reacted. The reaction solution was poured into methanol (310 ml), and the produced precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (E) powder. The imidation ratio of this polyimide was 80%, the number average molecular weight was 16,300, and the weight average molecular weight was 45,400.

<Example 7>
BODA (3.50 g, 14.0 mmol), PBCH5DAB (0.50 g, 1.16 mmol), p-PDA (1.89 g, 17.5 mmol), diamine (4) (1.10 g, 4.66 mmol) in NMP (14.9 g), and after reacting at 80 ° C. for 5 hours, CBDA (1.83 g, 9.33 mmol) and NMP (12.3 g) were added, and reacted at 40 ° C. for 6 hours to obtain polyamic acid. A solution (concentration 24.5% by mass) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6% by mass, acetic anhydride (2.45 g) and pyridine (1.93 g) were added as an imidization catalyst, and the mixture was heated at 80 ° C. for 4 hours. Reacted. The reaction solution was poured into methanol (280 ml), and the generated precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (F) powder. The imidation ratio of this polyimide was 55%, the number average molecular weight was 22,600, and the weight average molecular weight was 53,100.

<Example 8>
BODA (3.55 g, 14.2 mmol), PBCH5DAB (3.07 g, 7.10 mmol), p-PDA (1.28 g, 11.8 mmol), diamine (4) (1.12 g, 4.74 mmol) were added to NMP. (16.5 g), and the mixture was reacted at 80 ° C. for 5 hours. Then, CBDA (1.86 g, 9.48 mmol) and NMP (15.9 g) were added, and the mixture was reacted at 40 ° C. for 6 hours. A solution (concentration 25.2% by mass) was obtained.
After adding NMP to the obtained polyamic acid solution (20.5 g) and diluting to 6% by mass, acetic anhydride (4.50 g) and pyridine (3.30 g) were added as an imidization catalyst, and the mixture was stirred at 90 ° C. for 3 hours. Reacted. The reaction solution was poured into methanol (330 ml), and the generated precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (G) powder. The imidation ratio of this polyimide was 81%, the number average molecular weight was 16,100, and the weight average molecular weight was 44,800.

<Example 9>
BODA (3.50 g, 14.0 mmol), m-PBCH5DAB (3.12 g, 7.00 mmol), p-PDA (1.26 g, 11.7 mmol), diamine (4) (1.10 g, 4.66 mmol) Were mixed in NMP (16.4 g) and reacted at 80 ° C. for 5 hours, then CBDA (1.83 g, 9.33 mmol) and NMP (15.3 g) were added, and reacted at 40 ° C. for 6 hours. A polyamic acid solution (concentration 25.4% by mass) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6% by mass, acetic anhydride (2.48 g) and pyridine (1.95 g) were added as imidization catalysts, and the mixture was heated at 80 ° C. for 4 hours. Reacted. The reaction solution was poured into methanol (300 ml), and the produced precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (H) powder. The imidation ratio of this polyimide was 55%, the number average molecular weight was 18,200, and the weight average molecular weight was 48,500.

<Comparative Example 1>
BODA (3.53 g, 14.1 mmol), PCH7DAB (0.89 g, 2.34 mmol), p-PDA (2.29 g, 21.2 mmol) were mixed in NMP (13.1 g) and mixed at 80 ° C. for 5 hours. After reacting for a period of time, CBDA (1.85 g, 9.43 mmol) and NMP (12.4 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid (I) solution (concentration 25.0% by mass). Obtained. The number average molecular weight of this polyamic acid was 25,400, and the weight average molecular weight was 63,300.

<Comparative Example 2>
NMP was added to a solution (20.0 g) of polyamic acid (I) obtained in the same manner as in Synthesis Example 1 and diluted to 6% by mass, and then acetic anhydride (2.48 g) and pyridine (1 .92 g) was added and reacted at 80 ° C. for 4 hours. The reaction solution was poured into methanol (290 ml), and the produced precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (J) powder. The imidation ratio of this polyimide was 55%, the number average molecular weight was 22,300, and the weight average molecular weight was 56,300.

<Comparative Example 3>
BODA (3.51 g, 14.0 mmol), PCH7DAB (4.45 g, 11.7 mmol), p-PDA (1.26 g, 11.7 mmol) were mixed in NMP (17.3 g) and mixed at 80 ° C. for 5 hours. After reacting for a period of time, CBDA (1.83 g, 9.33 mmol) and NMP (15.3 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (concentration 25.3 mass%).
After adding NMP to the obtained polyamic acid solution (20.1 g) and diluting to 6% by mass, acetic anhydride (4.50 g) and pyridine (3.30 g) were added as an imidization catalyst, and the mixture was heated at 90 ° C. for 3 hours. Reacted. The reaction solution was poured into methanol (320 ml), and the generated precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (K) powder. The imidation ratio of this polyimide was 80%, the number average molecular weight was 16,100, and the weight average molecular weight was 44,200.

<Comparative Example 4>
BODA (3.50 g, 14.0 mmol), PBCH5DAB (3.03 g, 7.00 mmol), p-PDA (1.77 g, 16.4 mmol) were mixed in NMP (16.2 g) and mixed at 80 ° C. for 5 hours. After reacting for a period of time, CBDA (1.83 g, 9.33 mmol) and NMP (15.0 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (concentration 24.5% by mass).
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6% by mass, acetic anhydride (4.48 g) and pyridine (3.28 g) were added as an imidization catalyst, and the mixture was stirred at 90 ° C. for 3 hours. Reacted. The reaction solution was poured into methanol (320 ml), and the generated precipitate was separated by filtration. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain a polyimide (L) powder. The imidation ratio of this polyimide was 81%, the number average molecular weight was 19,500, and the weight average molecular weight was 49,400.

[Manufacture of liquid crystal alignment treatment agent]
In Examples 10 to 17 and Comparative Examples 5 to 11 described below, production examples of liquid crystal alignment treatment agents will be described. [Production of liquid crystal cell], [Liquid crystal used for evaluation of each liquid crystal alignment treatment agent] [Evaluation of orientation and pretilt angle] and [Evaluation of electrical characteristics] are as follows. The contents and properties of the liquid crystal alignment treatment agents obtained in Examples 10 to 17 and Comparative Examples 5 to 11 are summarized in Tables 4 and 5, respectively.

[Production of liquid crystal cell]
A liquid crystal alignment treatment agent is spin-coated on the ITO surface of the substrate with 3 × 4 cm ITO electrodes, and heat-treated on a hot plate at 80 ° C. for 5 minutes and in a thermal circulation clean oven for 30 minutes at 210 ° C. A 100 nm polyimide coating was obtained. The surface of the coating film was rubbed with a roll diameter 120 mm, rayon cloth rubbing apparatus under the conditions of a rotation speed of 700 rpm, a moving speed of 40 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film. Two substrates with this liquid crystal alignment film were prepared, a 6 μm spacer was sandwiched with the liquid crystal alignment film surface on the inside, the rubbing directions were reversed, and the surroundings were adhered with a sealant to produce an empty cell. . A liquid crystal (ZLI-2293, manufactured by Merck Japan Ltd.) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an antiparallel aligned nematic liquid crystal cell (hereinafter also referred to as a liquid crystal cell). . However, in Example 14, Example 16, Example 17, and Comparative Examples 3 to 7, MLC-6608 (manufactured by Merck Japan) was used as the liquid crystal.

[Evaluation of liquid crystal alignment and pretilt angle]
About the liquid crystal cell obtained in the above [Preparation of liquid crystal cell], after liquid crystal injection (initial), after heat treatment at 95 ° C. for 5 minutes (treatment 1 in Table 4), and after heat treatment at 120 ° C. for 5 hours, After the heat treatment for 5 minutes (treatment 2 in Table 4), the pretilt angle was measured. The pretilt angle was measured at three locations, the center of the liquid crystal cell and the location 1 cm above and below the center, and the average value thereof was taken as the pretilt angle value. At that time, the measurement was performed using a pretilt angle measuring device (model PAS-301 manufactured by ELSICON) at room temperature.
Moreover, about the liquid crystal cell after an initial stage and each heat processing, the orientation uniformity of the liquid crystal was confirmed by polarizing microscope observation. The state in which the liquid crystal was uniformly aligned was evaluated as “◯”, and the state in which the disorder of the liquid crystal was observed was evaluated as “×”.

[Evaluation of electrical characteristics]
A voltage of 4 V was applied to the liquid crystal cell obtained in [Preparation of liquid crystal cell] at a temperature of 80 ° C. for 60 μs, and the voltage after 16.67 ms and 1667 ms was measured. Was determined as a voltage holding ratio (initial voltage holding ratio in Table 5).
Further, the liquid crystal cell after the voltage holding ratio measurement was left in a thermostat set at 100 ° C. for 21 days, and the voltage holding ratio (voltage holding ratio after standing at high temperature in Table 5) was measured in the same manner as described above. .

[Rubbing resistance evaluation]
The surface of the substrate with the liquid crystal alignment film after the rubbing treatment obtained in [Preparation of liquid crystal cell] was observed with a confocal laser microscope to confirm the presence or absence of rubbing scratches.
A sample in which no rubbing scratch was observed was marked with ○, and a sample with rubbing scratch was marked with ×.

<Example 10>
A solution of the polyamic acid (A) (10.2 g), NMP (9.71 g) and BCS (20.0 g) obtained in the same manner as in Example 2 were mixed at 25 ° C. for 12 hours to conduct a liquid crystal alignment treatment. Agent (1) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 11>
Liquid crystal alignment treating agent obtained by mixing polyimide (B) powder (2.51 g), NMP (24.5 g) and BCS (11.6 g) obtained in the same manner as in Example 3 at 50 ° C. for 15 hours. (2) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 12>
A solution (10.5 g) of polyamic acid (C), NMP (11.6 g) and BCS (18.0 g) obtained in the same manner as in Example 4 were mixed at 25 ° C. for 12 hours to conduct liquid crystal alignment treatment. Agent (3) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 13>
A liquid crystal aligning agent obtained by mixing polyimide (D) powder (2.50 g), NMP (18.7 g) and BCS (17.3 g) obtained in the same manner as in Example 5 at 50 ° C. for 15 hours. (4) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 14>
Liquid crystal aligning agent by mixing polyimide (E) powder (2.55 g), NMP (26.9 g) and BCS (9.81 g) obtained in the same manner as in Example 6 at 50 ° C. for 15 hours. (5) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 15>
A polyimide (F) powder (2.48 g), NMP (16.6 g) and BCS (19.2 g) obtained in the same manner as in Example 7 were mixed at 50 ° C. for 15 hours to obtain a liquid crystal aligning agent. (6) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 16>
Liquid crystal aligning agent obtained by mixing polyimide (G) powder (2.50 g), NMP (28.3 g) and BCS (7.69 g) obtained in the same manner as in Example 8 at 50 ° C. for 15 hours. (7) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Example 17>
Liquid crystal aligning agent by mixing polyimide (H) powder (2.50 g), NMP (22.6 g) and BCS (13.4 g) obtained in the same manner as in Example 9 at 50 ° C. for 15 hours. (8) was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Comparative Example 5>
NMP (9.71 g) and BCS (20.2 g) were added to the polyamic acid (I) solution (10.5 g) obtained in Comparative Example 1, and the mixture was stirred at 25 ° C. for 12 hours, whereby a liquid crystal alignment treatment was performed. Agent (9) was obtained.

<Comparative Example 6>
The polyimide (J) powder (2.45 g), NMP (24.0 g) and BCS (11.3 g) obtained in Comparative Example 2 were mixed at 50 ° C. for 15 hours to obtain a liquid crystal alignment treatment agent (10). Obtained.

<Comparative Example 7>
The polyimide (K) powder (2.50 g), NMP (26.4 g), and BCS (9.62 g) obtained in Comparative Example 3 were mixed at 50 ° C. for 15 hours to obtain a liquid crystal aligning agent (11). Obtained.

<Comparative Example 8>
The polyimide (K) powder (2.45 g), NMP (31.1 g), BCS (11.3 g) and crosslinkable compound KK1 (0.49 g) obtained in the same manner as in Comparative Example 3 were heated to 50 ° C. For 15 hours to obtain a liquid crystal aligning agent (12).

<Comparative Example 9>
The polyimide (L) powder obtained in Comparative Example 4 (2.50 g), NMP (31.7 g), BCS (11.5 g) and crosslinkable compound KK1 (0.50 g) were mixed at 50 ° C. for 15 hours. As a result, a liquid crystal aligning agent (13) was obtained.

<Comparative Example 10>
A polyimide (K) powder (2.48 g), NMP (32.0 g), BCS (11.1 g) and a crosslinkable compound KK2 (0.50 g) obtained in the same manner as in Comparative Example 3 were heated to 50 ° C. For 15 hours to obtain a liquid crystal aligning agent (14).

<Comparative Example 11>
A polyimide (L) powder (2.52 g), NMP (31.8 g), BCS (11.4 g) and a crosslinkable compound KK2 (0.51 g) obtained in the same manner as in Comparative Example 4 were heated to 50 ° C. For 15 hours to obtain a liquid crystal aligning agent (15).

As can be seen from the above results, the liquid crystal alignment films obtained from the liquid crystal aligning agents of Examples 10 to 17 show uniform alignment, improve the stability of the pretilt angle against heat, and are exposed to high temperatures for a long time. When this was done, the decrease in voltage holding ratio was suppressed. On the other hand, in the liquid crystal alignment films obtained from the liquid crystal alignment treatment agents of Comparative Examples 5 to 7, the alignment disorder of the liquid crystal, which is considered to be caused by scratches due to rubbing, was observed. In addition, the pretilt angle significantly decreased after heat treatment at 120 ° C. for 5 hours (heat treatment 2). On the other hand, the liquid crystal alignment films obtained from the liquid crystal alignment treatment agents of Comparative Examples 8 to 11 had a large decrease in voltage holding ratio after standing at high temperature with respect to the initial voltage holding ratio.
In addition, the liquid crystal alignment films obtained from the liquid crystal alignment treatment agents of the examples from the comparison between the examples 10 and 12 and the comparative example 5 and the comparison between the examples 11 and 13 to 17 and the comparative examples 6 and 7 In this case, there was no shaving associated with the rubbing treatment, and the stability of the pretilt angle against heat was greatly improved. As a result, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of these examples provides a liquid crystal display element that does not cause display unevenness even under severe conditions such as being used or left in a high temperature environment for a long time. be able to.

In addition, the comparison between Examples 10 and 12 and Comparative Example 9, and the comparison between Examples 11 and 13 to 17 and Comparative Examples 6 and 7, and the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of Example, The decrease in the voltage holding ratio when exposed to a high temperature for a long time was suppressed. Thereby, the liquid crystal aligning film obtained from the liquid crystal aligning agent of these Examples can obtain a highly reliable liquid crystal display element that does not cause line sticking which is a display defect of the liquid crystal display element even under severe conditions. .
On the other hand, the liquid crystal alignment films obtained from the liquid crystal alignment treatment agents of Comparative Examples 8 to 11 had a large decrease in voltage holding ratio after standing at high temperature with respect to the initial voltage holding ratio.

The liquid crystal aligning agent of the present invention is useful for TN elements, STN elements, TFT liquid crystal elements, and vertical alignment type liquid crystal display elements, and can be suitably used particularly for large-screen and high-definition liquid crystal televisions. .

The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2009-295180 filed on Dec. 25, 2009 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims

At least selected from the group consisting of a polyamic acid obtained by reacting a diamine component containing a diamine compound represented by the formula [1] and tetracarboxylic dianhydride, and a polyimide obtained by dehydrating and ring-closing the polyamic acid. Liquid crystal aligning agent containing 1 type of polymer.

(In the formula [1], X 1 is —O—, —NH—, —N (CH 3 ) —, —CONH—, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON) (CH 3 ) — or —N (CH 3 ) CO—, and X 2 is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon. X 3 is a single bond, —O—, —NH—, —N (CH 3 ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH 3 ) —, —N (CH 3 ) CO— or —O (CH 2 ) m — (m is an integer of 1 to 5), X 4 represents an organic group having 1 to 20 carbon atoms, and n is 1 It is an integer of ~ 4.)
The liquid crystal aligning agent according to claim 1, wherein X 2 in the formula [1] is a single bond or an alkylene group having 1 to 5 carbon atoms.
The liquid crystal aligning agent according to claim 1 or 2, wherein X 4 in the formula [1] is an alkyl group having 1 to 5 carbon atoms.
X 1 in the formula [1] is —O—, —CONH—, or —COO—, X 3 is a single bond or —O—, and n is 1. A liquid crystal alignment treatment agent according to claim 1.
5. The liquid crystal aligning agent according to claim 1, wherein 5 to 80 mol% in the diamine component is a diamine compound represented by the formula [1].
A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of claims 1 to 5.
A liquid crystal display element having the liquid crystal alignment film according to claim 6.
A diamine compound represented by the following formula [1].

(In the formula [1], X 1 is —O—, —NH—, —N (CH 3 ) —, —CONH—, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON) (CH 3 ) — or —N (CH 3 ) CO—, and X 2 is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, or an aromatic hydrocarbon. X 3 is a single bond, —O—, —NH—, —N (CH 3 ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH 3 ) —, —N (CH 3 ) CO— or —O (CH 2 ) m — (m is an integer of 1 to 5), X 4 represents an organic group having 1 to 20 carbon atoms, and n is 1 It is an integer of ~ 4.)
A polyamic acid obtained by reacting a diamine component containing the diamine compound represented by the formula [1] according to claim 8 and tetracarboxylic dianhydride, or a polyimide obtained by dehydrating and ring-closing the polyamic acid.