JPWO2012161329A1 - Liquid crystal alignment treatment agent and liquid crystal display element using the same - Google Patents

Abstract

Provided are a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element, which are highly effective in shortening the time until an afterimage generated by a direct current voltage disappears, improve ultraviolet resistance, and do not reduce shaving characteristics. At least one polymer selected from the group consisting of a polyimide precursor and polyimide, and a compound represented by the following formula [1] (wherein R1 is a hydrogen atom or a vinyl group, and n is an integer of 0 to 2). And a liquid crystal aligning agent containing. (Chemical formula 1)

Description

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

Currently, as a liquid crystal alignment film of a liquid crystal display element, a so-called polyimide-based liquid crystal alignment film is obtained by applying a liquid crystal alignment treatment agent mainly composed of a polyimide precursor such as polyamic acid or a solution of soluble polyimide to a substrate and baking it. Mainly used. The liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal.
With the high definition of liquid crystal display elements, from the viewpoint of reducing the afterimage phenomenon, there is a demand for a material that can quickly relax charges accumulated by a DC voltage in a liquid crystal alignment film used there. In the polyimide-based liquid crystal alignment film, a liquid crystal aligning agent containing a tertiary amine having a specific structure in addition to polyamic acid or imide group-containing polyamic acid was used as a short time until the afterimage generated by direct current voltage disappeared. There are known ones (for example, see Patent Document 1) and those using a liquid crystal aligning agent containing a soluble polyimide using a specific diamine having a pyridine skeleton as a raw material (for example, see Patent Document 2).

  In addition to the property that the accumulated charge is quickly relaxed, the liquid crystal alignment treatment agent is required to be a material that is difficult to be removed even when the rubbing alignment treatment is performed from the viewpoint of reducing display unevenness. In addition to these characteristics, recent liquid crystal display element manufacturing processes include a process of irradiating ultraviolet rays in an ODF process, a PSA process, and the like, and a material resistant to ultraviolet rays is required.

Japanese Unexamined Patent Publication No. 9-316200 Japanese Unexamined Patent Publication No. 10-104633

  In view of the above situation, the present invention is highly effective in shortening the time until the afterimage generated by the DC voltage disappears, improves the UV resistance, does not reduce the shaving characteristics, and liquid crystal alignment treatment using the same It is an object to provide an agent and a liquid crystal display element using the agent.

  As a result of intensive studies to achieve the above object, the present inventor has found that in addition to at least one polymer selected from the group consisting of a polyimide precursor and a polyimide, a specific substance, part of which is the present application The present inventors have found that such an object can be achieved by a liquid crystal aligning agent containing a novel substance before the application, and have reached the present invention. The present application has the following gist.

(1) At least one polymer selected from the group consisting of a polyimide precursor and polyimide, and a compound represented by the following formula [1] (wherein R ₁ represents a hydrogen atom or a vinyl group, and n represents 0 Represents an integer of ˜2), and a liquid crystal aligning agent.

（２）式［１］で表される化合物が、ポリイミド前駆体及びポリイミドから選ばれる少なくとも１種の重合体１００質量部に対して、０．１〜１０質量部含有される上記（１）に記載の液晶配向処理剤。
（３）式［１］のＲ_１がビニル基である上記（１）又は（２）に記載の液晶配向処理剤。
（４）式［１］で表される化合物が、下記のＭ１、Ｍ２、Ｍ３又はＭ４である上記（１）〜（３）のいずれかに記載の液晶配向処理剤。

(2) In the above (1), the compound represented by the formula [1] is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one polymer selected from a polyimide precursor and a polyimide. The liquid crystal aligning agent of description.
(3) type liquid crystal alignment treating agent according to the above _{R 1} is a vinyl group [1] (1) or (2).
(4) The liquid-crystal aligning agent in any one of said (1)-(3) whose compound represented by Formula [1] is following M1, M2, M3, or M4.

（５）固形分を０．５〜１０質量％含有する上記（１）〜（４）のいずれかに記載の液晶配向処理剤。
（６）上記（１）〜（５）のいずれかに記載の液晶配向処理剤から得られる液晶配向膜。
（７）上記（６）に記載の液晶配向膜を具備する液晶表示素子。
（８）下記式[２]にて表される化合物（式中、ｎは０〜２の整数を表す）。

(5) The liquid-crystal aligning agent in any one of said (1)-(4) containing 0.5-10 mass% of solid content.
(6) A liquid crystal alignment film obtained from the liquid crystal alignment treatment agent according to any one of (1) to (5).
(7) A liquid crystal display device comprising the liquid crystal alignment film according to (6).
(8) A compound represented by the following formula [2] (wherein n represents an integer of 0 to 2).

ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning agent which can shorten the time until the afterimage generated by direct current voltage disappears, improves ultraviolet-ray tolerance, and does not reduce a shaving characteristic is provided.
Moreover, a part of the said compound added to the liquid-crystal aligning agent of this invention is a novel compound before this-application application, According to this invention, this novel compound is also provided.

式中、Ｒ₁は水素原子又はビニル基を表し、ｎは０〜２の整数、好ましくは１又は２の整数を表す。
Ｒ₁は水素原子又はビニル基を表すが、得られる液晶配向膜の残像特性の観点から、ビニル基が好ましい。[Additive]
The liquid crystal aligning agent of the present invention is added with a compound represented by the following formula [1] (hereinafter also referred to as the additive of the present invention).

In the formula, R ₁ represents a hydrogen atom or a vinyl group, and n represents an integer of 0 to 2, preferably an integer of 1 or 2.
R ₁ represents a hydrogen atom or a vinyl group, and a vinyl group is preferred from the viewpoint of the afterimage characteristics of the obtained liquid crystal alignment film.

液晶配向処理剤における本発明の添加剤の含有量としては、ポリイミド前駆体及びポリイミドからなる群から選ばれる少なくとも１種の重合体１００質量部に対して、０．１〜１０質量部が好ましく、１〜１０質量部がより好ましく、１〜５質量部が特に好ましい。Preferable specific examples of the additive of the present invention include the following M1 to M12. Among them, M1, M2, M3, or M4 is preferable.

As content of the additive of this invention in a liquid-crystal aligning agent, 0.1-10 mass parts is preferable with respect to 100 mass parts of at least 1 sort (s) of polymers chosen from the group which consists of a polyimide precursor and a polyimide, 1-10 mass parts is more preferable, and 1-5 mass parts is especially preferable.

[Method of synthesizing additives]
The method for synthesizing the additive of the present invention can be synthesized by combining techniques of organic synthetic chemistry, and is not particularly limited. For example, it can be synthesized by the following method.
The additive represented by the general formula [1] of the present invention, as shown in the following synthesis schemes (A), (B) and the like, is a reaction between the compound (i) and an organometallic reagent such as vinylmagnesium bromide, It can be synthesized by reacting compound (i) with a reducing agent such as sodium borohydride.

A commercially available compound may be used for the aldehyde compound represented by the formula (i) in the synthesis schemes (A) and (B), and the corresponding aniline compound and the aryl halide are crossed using a palladium catalyst. It may be synthesized by a coupling reaction.
Preferred specific methods for the synthesis scheme (A) and the synthesis scheme (B) are as described in respective synthesis examples described later.

[Polyimide precursor and polyimide]
In the present invention, the polyimide precursor means polyamic acid (also referred to as polyamic acid) and polyamic acid ester. A polyamic acid is obtained by reaction of a diamine component and tetracarboxylic dianhydride. The polyamic acid ester is obtained by reacting the diamine component and tetracarboxylic acid diester dichloride in the presence of a base, or reacting the tetracarboxylic acid diester and diamine in the presence of a suitable condensing agent or base. The polyimide of the present invention can be obtained by dehydrating and ring-closing this polyamic acid or by heating and ring-closing the polyamic acid ester. Any of such polyamic acid, polyamic acid ester, and polyimide is useful as a polymer for obtaining a liquid crystal alignment film.

The diamine component used in the production of the polyimide precursor is not particularly limited, and examples thereof include alicyclic diamine, aromatic diamine, aromatic-aliphatic diamine, heterocyclic diamine, and aliphatic diamine. For example:
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylamine, isophorone Examples include diamines.

  Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1,4-diamino. 2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3,5-diaminobenzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4 '-Diamino-1,2-diphenylethane, 4,4'-diamino-2,2'-dimethylbibenzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminostilbene, 4,4'-diamy Stilbene, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 4,4′- Diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis (4- Aminophenoxy) benzoic acid, 4,4′-bis (4-aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,1-bis (4-aminophenyl) cyclohexane, α, α′-bis (4- Aminophenyl) -1,4-diisopropylbenzene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) Hexafluoropropane, 4,4'-diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrene, 1,6 -Diaminopyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-amino Enyl) tetramethyldisiloxane, benzidine, 2,2′-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4 -Aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane, 1,7-bis (4-aminophenyl) heptane, 1,8-bis (4-aminophenyl) octane, 1,9-bis (4-aminophenyl) nonane, 1,10-bis (4-aminophenyl) decane, 1,3-bis (4-aminophenoxy) propane, 1,4 -Bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4- Aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,10-bis (4-aminophenoxy) decane, di (4-aminophenyl) ) Propane-1,3-dioate, di (4-aminophenyl) butane-1,4-dioate, di (4-aminophenyl) pentane-1,5-dioate, di (4-aminophenyl) hexane-1, 6-dioate, di (4-aminophenyl) heptane-1,7-dioate, di (4-aminophenyl) octane-1,8-dioate, di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) decane-1,10-dioate, 1,3-bis [4- (4-aminophenoxy) phenoxy] propane, 1,4-bi [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, , 7-bis [4- (4-aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy Nonane, 1,10-bis [4- (4-aminophenoxy) phenoxy] decane, and the like.

  Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4- Aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3- (3-aminopropyl) aniline, 4- (3-aminopropyl) aniline, 3- (3-methylaminopropyl) Aniline, 4- (3-methylaminopropyl) aniline, 3- (4-aminobutyl) aniline, 4- (4-aminobutyl) aniline, 3- (4-methylaminobutyl) aniline, 4- (4-methyl) Aminobutyl) aniline, 3- (5-aminopentyl) aniline, 4- (5-aminopentyl) Niline, 3- (5-methylaminopentyl) aniline, 4- (5-methylaminopentyl) aniline, 2- (6-aminonaphthyl) methylamine, 3- (6-aminonaphthyl) methylamine, 2- (6 -Aminonaphthyl) ethylamine, 3- (6-aminonaphthyl) ethylamine and the like.

Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6-diaminocarbazole 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole, and the like.
Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane. 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7 -Diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylheptane, 1,12-diamino Examples include dodecane, 1,18-diaminooctadecane, and 1,2-bis (3-aminopropoxy) ethane.
In addition to the above diamine, a diamine compound having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, or a macrocyclic substituent composed thereof (hereinafter also referred to as other diamine) in the side chain. .) May be used in combination. Specific examples of the other diamines include diamines represented by the following formulas [DA1] to [DA26].

（式［ＤＡ１］〜式［ＤＡ５］中、Ｒ_６は、炭素数１〜２２のアルキル基又はフッ素含有アルキル基である。）

(In Formula [DA1] to Formula [DA5], R ₆ is an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

（式［ＤＡ６］〜式［ＤＡ９］中、Ｓ_５は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＨ_２−、−Ｏ−、−ＣＯ−、又は−ＮＨ−を示し、Ｒ_６は炭素数１〜２２のアルキル基又はフッ素含有アルキル基を示す。）

(In Formula [DA6] to Formula [DA9], S ₅ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. R ₆ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

（式［ＤＡ１０］及び式［ＤＡ１１］中、Ｓ_６は、−Ｏ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯＣＨ_２−、又は−ＣＨ_２ＯＣＯ−を示し、Ｒ_７は炭素数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

(In formula [DA10] and formula [DA11], S ₆ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ₇ represents the number of carbon atoms. 1 to 22 alkyl groups, alkoxy groups, fluorine-containing alkyl groups or fluorine-containing alkoxy groups.)

（式［ＤＡ１２］〜式［ＤＡ１４］中、Ｓ_７は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、又は−ＣＨ_２−を示し、Ｒ_８は炭素数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

(In Formula [DA12] to Formula [DA14], S ₇ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — OCH ₂ — or —CH ₂ — is shown, and R ₈ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

（式［ＤＡ１５］及び式［ＤＡ１６］中、Ｓ_８は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＨ_２−、−Ｏ−、又は−ＮＨ−を示し、Ｒ_９はフッ素基、シアノ基、トリフルオロメチル基、ニトロ基、アゾ基、ホルミル基、アセチル基、アセトキシ基、又は水酸基である。）

(In Formula [DA15] and Formula [DA16], S ₈ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — Represents OCH ₂ —, —CH ₂ —, —O—, or —NH—, and R ₉ represents a fluorine group, a cyano group, a trifluoromethyl group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or It is a hydroxyl group.)

（式［ＤＡ１７］〜［ＤＡ２０］中、Ｒ_１０は炭素数３〜１２のアルキル基であり、１，４−シクロへキシレンのシス−トランス異性は、それぞれトランス体である。）

(In the formulas [DA17] to [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.)

式［ＤＡ３１］中、ｍは０〜３の整数であり、式［ＤＡ３４］中、ｎは１〜５の整数である）。[ＤＡ−２７]や[ＤＡ−２８]は導入することにより液晶表示素子の電圧保持率（ＶＨＲとも言う）を向上させることができ、[ＤＡ−２９]〜［ＤＡ−３４］は液晶表示素子の蓄積電荷低減に効果があるため、好ましい。Moreover, the diamine shown below can also be used together.

In the formula [DA31], m is an integer of 0 to 3, and in the formula [DA34], n is an integer of 1 to 5). By introducing [DA-27] and [DA-28], the voltage holding ratio (also referred to as VHR) of the liquid crystal display element can be improved, and [DA-29] to [DA-34] are liquid crystal display elements. This is preferable because it is effective in reducing the accumulated charge.

（式［ＤＡ３５］中、ｍは、１〜１０の整数である。）
上記した、その他のジアミン化合物は、液晶配向膜とした際の液晶配向性、電圧保持特性、蓄積電荷などの特性に応じて、１種類又は２種類以上を混合して使用することもできる。Furthermore, the diaminosiloxane etc. which are shown by the following formula [DA35] can also be mentioned.

(In the formula [DA35], m is an integer of 1 to 10.)
The other diamine compounds described above can be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

The tetracarboxylic dianhydride reacted with the diamine component to obtain the polyamic acid of the present invention is not particularly limited. Specific examples are given below.
Examples of the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic Acid dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1, , 3,4-Butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetra Carboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride , Tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-dianhydride, hexacyclo [6.6.0.12,7 .03, 6.19, 14.010, 13] hexadecane-4,5,11,12-tetracarboxylic acid-4,5: 11,12-dianhydride, 4- (2,5-dioxotetrahydrofuran- 3-yl) -1,2,3,4-tetrahydronaphth Examples include tarene-1,2-dicarboxylic acid anhydride.

Furthermore, when an aromatic tetracarboxylic dianhydride is used in addition to the tetracyclic dianhydride having the alicyclic structure or aliphatic structure, the liquid crystal alignment is improved and the accumulated charge of the liquid crystal cell is reduced. Since it can reduce, it is preferable. As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic acid Dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4-benzophenonetetra Carboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride Products, 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like.
The tetracarboxylic dianhydride can be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

[Synthesis of polyamic acid]
In obtaining the polyamic acid of the present invention by reaction of tetracarboxylic dianhydride and a diamine component, a known synthesis method can be used. In general, tetracarboxylic dianhydride and a diamine component 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 of tetracarboxylic dianhydride and diamine is not particularly limited as long as the produced polyamic acid is soluble. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide , 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, ethyl 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, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropion , 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy -N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like can be mentioned. These may be used alone or in combination. Furthermore, even a solvent that does not dissolve polyamic acid may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate.

Further, 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 as much as possible.
When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is used as it is or in an organic solvent. A method of adding by dispersing or dissolving, a method of adding a diamine component to a solution obtained by dispersing or dissolving tetracarboxylic dianhydride in an organic solvent, and alternately adding a tetracarboxylic dianhydride and a diamine component. Any of these methods may be used. Further, 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 and reacted to form a high molecular weight product.

Although the polymerization temperature in that case can select the arbitrary temperature of -20 degreeC-150 degreeC, Preferably it is the range of -5 degreeC-100 degreeC. 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 total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution 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 polyamic acid polymerization reaction, the ratio of the total number of moles of tetracarboxylic dianhydride and the total number of moles of the diamine component is preferably 0.8 to 1.2, preferably 0.9 to 1.1. More preferably. 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.

[Synthesis of polyamic acid ester]
As a method of synthesizing a polyamic acid ester, a reaction between a tetracarboxylic acid diester dichloride and a diamine, or a reaction between a tetracarboxylic acid diester and a diamine in the presence of an appropriate condensing agent and a base, a kind of polyimide precursor. The polyamic acid ester which is can be obtained. Alternatively, it can also be obtained by polymerizing a polyamic acid in advance and esterifying the carboxylic acid in the amic acid using a polymer reaction.
Specifically, tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent are −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., 30 minutes to 24 hours, preferably 1 to 4 hours. It can be synthesized by reacting.

As the base, pyridine, triethylamine, or 4-dimethylaminopyridine can be used, but pyridine is preferable because the reaction proceeds gently. The addition amount of the base is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.
When conducting condensation polymerization in the presence of a condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1, 3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazole-1- Yl) -N, N, N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate diphenyl, 4- (4,6 -Dimethoxy-1,3,5-triazin-2-yl) 4-methoxymorpholium chloride n-hydrate can be used.
In the method using the condensing agent, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0.1 to 1.0 times the molar amount relative to (C1).

  The solvent used in the above reaction can be the solvent used when polymerizing the polyamic acid shown above, but N-methyl-2-pyrrolidone or γ-butyrolactone is used from the solubility of the monomer and polymer. These may be used alone or in combination of two or more. The concentration at the time of synthesis is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained. Moreover, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

In the present invention, the tetracarboxylic acid diester to be reacted with the diamine component in order to obtain a polyamic acid ester is not particularly limited, but is preferably an aliphatic tetracarboxylic acid diester or an aromatic tetracarboxylic acid dialkyl ester. To
Specific examples of the aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2 , 3,4-cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy- 1-cyclohexyl succinic acid dialkyl ester, 3,4-dicarboxy 1,2,3,4-tetrahydro-1-naphthalene succinic acid dialkyl ester, 1,2,3,4-butanetetracarboxylic acid dialkyl ester, bicyclo [3,3,0] octane-2,4,6,8 -Tetracarboxylic acid dialkyl ester, 3,3 ', 4,4'-dicyclohexyl tetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentylacetic acid dialkyl ester, cis-3,7-dibutylcycloocta-1,5 -Diene-1,2,5,6-tetracarboxylic acid dialkyl ester, tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3, 4: 7,8 -Dialkyl ester, hexacyclo [6.6.0.12,7.03,6.19,14.010,13] hexadecane-4,5,11,1 2-tetracarboxylic acid-4,5: 11,12-dialkyl ester, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl Examples include esters.

  Specific examples of the aromatic tetracarboxylic acid dialkyl ester include pyromellitic acid dialkyl ester, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dialkyl ester, and 2,2 ′, 3,3′-biphenyltetracarboxylic acid. Dialkyl ester, 2,3,3 ′, 4-biphenyltetracarboxylic acid dialkyl ester, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dialkyl ester, 2,3,3 ′, 4-benzophenone tetracarboxylic acid dialkyl Ester, bis (3,4-dicarboxyphenyl) ether dialkyl ester, bis (3,4-dicarboxyphenyl) sulfone dialkyl ester, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl ester, 2,3,6 , 7-Naphthalenetetracarboxylic acid dialkyl Ester and the like.

[Synthesis of polyimide]
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 (imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.
Examples of the method for imidizing a polyimide precursor such as polyamic acid include thermal imidization in which a 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 is preferably performed while removing water generated by the imidation reaction from the system.
The catalytic imidation of the polyamic acid can be performed 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 amidic 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.

[Polymer recovery]
When recovering the produced polyamic acid, polyamic acid ester, and polyimide from the reaction solution of polyamic acid, polyamic acid ester, and polyimide, 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. Moreover, when the polymer which carried out precipitation collection | recovery is re-dissolved in an organic solvent and the operation which carries out reprecipitation collection | recovery is repeated 2 to 10 times, the impurity in a polymer can be decreased. 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 polyimide precursor such as polyamic acid and the polyimide contained in the liquid crystal aligning agent of the present invention was determined in consideration of the strength of the coating film obtained therefrom, workability during coating film formation, and uniformity of the coating film. In this case, the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal alignment agent>
The liquid crystal alignment treatment agent of the present invention is a coating liquid for forming a liquid crystal alignment film, and at least one polymer selected from the group consisting of the above polyimide precursor and polyimide and the additive of the present invention are organic solvents. It is a solution dissolved in The solid content concentration in the liquid crystal alignment treatment agent of the present invention can be appropriately changed depending on the thickness of the liquid crystal alignment film to be formed, but is preferably 0.5 to 10% by mass, and preferably 1 to 8% by mass. More preferably. When the solid content concentration is less than 0.5% by mass, it is difficult to form a uniform and defect-free coating film, and when it is higher than 10% by mass, the storage stability of the solution may be deteriorated. The solid content mentioned here means a component obtained by removing the solvent from the liquid crystal aligning agent, and at least one polymer selected from the polyimide precursor and polyimide described above, the additive of the present invention, and various additives described below. Means. Specifically, as a procedure for measuring the solid content, a small amount of liquid crystal alignment treatment agent is placed in an aluminum container previously weighed and weighed, and heated in an oven at 200 ° C. for 1 hour. Then evaporate the solvent, and then weigh the aluminum container. It is obtained by calculating from these values.

The manufacturing method of the liquid-crystal aligning agent of this invention is not specifically limited. Usually, it is produced by mixing a polyimide solution or a polyimide precursor solution such as polyamic acid and a polyimide solution. In the case of a polyimide precursor such as polyamic acid, the reaction solution of polyamic acid obtained by polycondensation may be used as it is, or once the polyamic acid is obtained, it is redissolved in an organic solvent. Can be used as a polyamic acid solution. The polyamic acid solution may be used after diluted to a desired concentration.
On the other hand, in the case of polyimide, the reaction solution of soluble polyimide obtained by imidization may be used as it is, or after obtaining polyimide powder, it is redissolved in an organic solvent and used as a polyimide solution. can do. The polyimide solution may be used after diluting to a desired concentration.

The organic solvent used for the liquid crystal aligning agent of the present invention is particularly an organic solvent that dissolves at least one polymer (hereinafter also referred to as a resin component) selected from the group consisting of the above polyimide precursor and polyimide. It is not limited. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide, 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 Such as methyl-2-pentanone and the like. These may be used alone or in combination.

The liquid crystal aligning agent of this invention may contain components other than the above. Examples thereof include solvents and additives that improve the film thickness uniformity and surface smoothness when a liquid crystal alignment treatment agent is applied, and additives that improve the adhesion between the liquid crystal alignment film and the substrate.
The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of the film thickness and the surface smoothness. 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, 1-hexanol, 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, Ethyl 3-methoxypropionate, 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- Low 1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester A solvent having a surface tension may be mentioned.
These poor solvents may be used alone or in combination. When using the above solvent, it is preferable that it is 5-80 mass% of the whole solvent contained in a liquid-crystal aligning agent, More preferably, it is 20-60 mass%.

Examples of the additive 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, EFTOP 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 alignment treatment agent. .

Specific examples of the additive for improving 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-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N Examples include ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane.

[Liquid crystal alignment film]
The liquid crystal alignment treatment agent of the present invention is preferably filtered before being applied to the substrate, and then applied to the substrate, dried and baked to form a coating film. By performing alignment treatment such as irradiation, it is used as the liquid crystal alignment film of the present invention.
At this time, 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 can be used, and an ITO electrode for driving a liquid crystal is formed. It is preferable to use a new substrate from the viewpoint of simplification of the process. In the reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light such as aluminum can be used as the electrode.

Examples of the method for applying the liquid crystal aligning agent include a spin coating method, a printing method, and an ink jet method. From the viewpoint of productivity, the flexographic printing method is widely used industrially, and the liquid crystal aligning agent of the present invention is used. Is also preferably used.
The drying process after applying the liquid crystal alignment treatment agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, the drying process is performed. Inclusion is preferred. This drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. If a specific example is given, the method of drying on a hotplate of 50-150 degreeC, Preferably 80-120 degreeC for 0.5 to 30 minutes, Preferably it is 1 to 5 minutes is taken.

The substrate coated with the liquid crystal aligning agent can be baked at an arbitrary temperature of 100 to 350 ° C., preferably 150 to 300 ° C., more preferably 180 to 250 ° C. The polyamic acid contained in the liquid crystal aligning agent changes the conversion rate from the amic acid to the imide by this baking, but the polyamic acid does not necessarily need to be 100% imidized. However, baking is preferably performed at a temperature higher by 10 ° C. or more than the heat treatment temperature required for the manufacturing process of the liquid crystal cell, such as curing of the sealant.
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, so it is preferably 10 to 200 nm, more preferably 50-100 nm.
An existing rubbing apparatus can be used for rubbing the coating surface formed on the substrate as described above. Examples of the material of the rubbing cloth at this time include cotton, rayon, and nylon.

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.
As an example of liquid crystal cell production, a pair of substrates on which a liquid crystal alignment film is formed is preferably an arbitrary rubbing direction of 0 to 270 ° with a spacer of 1 to 30 μm, more preferably 2 to 10 μm sandwiched between them. A method is generally used in which the angle is set to be fixed, the periphery is fixed with a sealant, and liquid crystal is injected and sealed. The method for enclosing the liquid crystal is not particularly limited, and examples thereof include a vacuum method of injecting liquid crystal after reducing the pressure inside the produced liquid crystal cell, and a dropping method of sealing after dropping the liquid crystal.
The liquid crystal display element obtained by using the liquid crystal alignment treatment agent of the present invention has good afterimage characteristics and liquid crystal alignment properties, display defects associated with scratches and peeling of the liquid crystal alignment film generated during rubbing treatment, and ultraviolet rays A reduction in electrical characteristics due to irradiation is significantly reduced, and a highly reliable liquid crystal display device can be obtained.

The present invention will be described in more detail with reference to the following examples, but the present invention should not be construed as being limited thereto.
"Synthesis of additives"
The synthesis example of the additive in this invention is shown. Each measuring method and analyzer used are as follows.
<Measurement of NMR>
The compound was dissolved in deuterated chloroform and measured using 400 MHz ¹ H NMR (manufactured by Varian).

(Synthesis Example 1) Synthesis of Additive (M1) Bis (4-formylphenyl) phenylamine (11.5 g) and tetrahydrofuran (230 g) were added to a 500 mL (liter) four-necked flask and cooled in an ice bath. At a temperature of 0 ° C., 60.1 mL of a tetrahydrofuran solution of vinylmagnesium chloride having a concentration of 1.46 mol / L was added dropwise and stirred at room temperature for 18 hours. Then, 15 wt% ammonium chloride aqueous solution was added and extracted using ethyl acetate. After adding anhydrous magnesium sulfate to the organic layer and filtering, the solvent was distilled off using a rotary evaporator to obtain 13.2 g of a reddish brown viscous liquid.
The result of measuring this reddish brown liquid by NMR is shown below. From this result, it was confirmed that the obtained reddish brown liquid was the following formula (M1).
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.28-7.21 (m, 6H), 7.10-6.99 (m, 7H), 6.07 (ddd, 2H), 5.40- 5.34 (m, 2H), 5.24-5.15 (m, 4H), 1.88 (d, 2H)

(Synthesis example 2) Synthesis | combination of additive (M2) 4- (N, N-diphenylamino) benzaldehyde 11.7g and tetrahydrofuran 240g were added to a 500 mL four necked flask, and it cooled in the ice bath. At a temperature of 0 ° C., 32.3 mL of a tetrahydrofuran solution of vinylmagnesium chloride having a concentration of 1.46 mol / L was dropped, and the mixture was stirred at room temperature for 48 hours. Then, 15 wt% ammonium chloride aqueous solution was added and extracted using ethyl acetate. After adding anhydrous magnesium sulfate to the organic layer and filtering, the solvent was distilled off using a rotary evaporator to obtain 12.6 g of a reddish brown viscous liquid.
The result of measuring this reddish brown liquid by NMR is shown below. From this result, it was confirmed that the obtained reddish brown liquid was represented by the following formula (M2).
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.27-7.21 (m, 6H), 7.10-6.98 (m, 8H), 6.08 (ddd, 1H), 5.40- 5.34 (m, 1H), 5.24-5.14 (m, 2H), 1.88 (d, 1H)

(Synthesis Example 3) Synthesis of Additive (M3) 11.5 g of bis (4-formylphenyl) phenylamine and 220 g of methanol were added to a 500 mL four-necked flask and cooled in an ice bath. At a temperature of 0 ° C., 3.1 g of sodium borohydride was added and stirred at room temperature for 24 hours. After cooling in an ice bath, a 10 wt% aqueous ammonium chloride solution was added, and the mixture was extracted with ethyl acetate. Water was added to the organic layer for liquid separation, and anhydrous magnesium sulfate was added to the organic layer. After filtering the magnesium sulfate, the solvent was distilled off using a rotary evaporator to obtain 11.6 g of a white solid.
The result of measuring this white solid by NMR is shown below. From this result, it confirmed that the obtained white solid was a following formula (M3).
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.27-7.22 (m, 6H), 7.10-7.05 (m, 6H), 7.05-6.99 (m, 1H), 4.64 (d, 4H), 1.60 (t, 2H)

Synthesis Example 4 Synthesis of Additive (M4) 13.0 g of bis (4-formylphenyl) phenylamine and 260 g of methanol were added to a 500 mL four-necked flask and cooled in an ice bath. At a temperature of 0 ° C., 2.0 g of sodium borohydride was added and stirred at room temperature for 9 hours. After cooling in an ice bath, a 10 wt% aqueous ammonium chloride solution was added, and the mixture was extracted with ethyl acetate. Water was added to the organic layer for liquid separation, and anhydrous magnesium sulfate was added to the organic layer. After magnesium sulfate was filtered, the solvent was distilled off using a rotary evaporator to obtain 13.0 g of a white solid.
The result of measuring this white solid by NMR is shown below. From this result, it confirmed that the obtained white solid was a following formula (M4).
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.27-7.22 (m, 6H), 7.10-7.05 (m, 6H), 7.04-6.99 (m, 2H), 4.64 (d, 2H), 1.58 (t, 1H)

"Synthesis of polyamic acid and polyimide"
The synthesis example of resin and resin solution in this invention is shown. Each measuring method and analyzer used are as follows.
Explanation of abbreviations used <Tetracarboxylic dianhydride>
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride TDA: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride PMDA: pyromellitic acid 2 Anhydride BODA: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride TCA: 2,3,5-tricarboxycyclopentylacetic acid dianhydride

<Diamine>
DDM: 4,4′-diaminodiphenylmethane PDA: p-phenylenediamine APC18: 1,3-diamino-4-octadecyloxybenzene DADPA: 4,4′-diaminodiphenylamine <organic solvent>
NMP: N-methyl-2-pyrrolidone γ-BL: butyrolactone BCS: butyl cellosolve

<Measurement of molecular weight>
The molecular weight of the polyimide was measured with a GPC (normal temperature gel permeation chromatography) apparatus, and the number average molecular weight and weight average molecular weight were calculated as polyethylene glycol and polyethylene oxide equivalent values.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H 2 O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF ) Is 10 mL / L)
Flow rate: 1.0 mL / minute standard sample for preparing calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4000, 1000) manufactured by Polymer Laboratories .

<Measurement of imidization ratio>
The imidization rate of polyimide was measured by using 400 MHz ¹ H NMR (manufactured by Varian) by dissolving the polyimide in d6-DMSO (dimethyl sulfoxide-d6), and remaining amidic acid without imidization. The group ratio was calculated from the ratio of the integrated values of proton peaks.

"Production example of polymer solution"
(Production Example 1)
In a 500 mL four-necked flask, 11.7 g of PDA, 4.5 g of APC18, and 206 g of NMP were added and dissolved, and 35.3 g of TDA was added. A polymer solution (P-1) was prepared by reacting at room temperature for 11 hours under a nitrogen atmosphere.
To the obtained polymer solution (P-1) 180 g, 270 g of NMP was added for dilution, 56.2 g of acetic anhydride and 43.5 g of pyridine were added, and the mixture was reacted at 40 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 2000 mL of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder. The number average molecular weight of this polyimide was 6,500, and the weight average molecular weight was 14,400. The imidation ratio was 80%.
24 g of the obtained powder and 216 g of γ-BL were added to a 1 L eggplant flask and stirred at 50 ° C. for 14 hours to obtain a polymer solution (P-2). BCS120g and (gamma) -BL40g were further added to the obtained polymer solution (P-2), and it stirred at room temperature for 18 hours, and obtained the polymer solution (P-3).

(Production Example 2)
In a 500 mL four-necked flask, 39.6 g of DDM, 222 g of NMP, and 222 g of γ-BL were added and dissolved, and 19.6 g of CBDA and 19.2 g of PMDA were added. Under a nitrogen atmosphere, the mixture was reacted at room temperature for 5 hours to prepare a polymer solution (P-4). This polymer had a number average molecular weight of 10,900 and a weight average molecular weight of 27,300.
To 400 g of the obtained polymer solution (P-4), 450 g of γ-BL and 150 g of BCS were added and stirred at room temperature for 2 hours to obtain a polymer solution (P-5).

(Production Example 3)
50 g of the polymer solution (P-3) obtained in Resin Production Example 1 and 400 g of the polymer solution (P-5) obtained in Resin Production Example 2 were stirred at room temperature for 20 hours, and the polymer solution (P-6) was stirred. Obtained.
(Production Example 4) BODA / DADPA
In a 500 mL four-necked flask, 39.9 g of DADDA and 356 g of NMP were added and dissolved, and 49.0 g of BODA was added. The mixture was reacted at 50 ° C. for 24 hours under a nitrogen atmosphere to prepare a polymer solution (P-7). This polymer had a number average molecular weight of 13,100 and a weight average molecular weight of 31,300.
500 g of NMP and 200 g of BCS were added to 300 g of the obtained polymer solution (P-7), and the mixture was stirred at room temperature for 2 hours to obtain a polymer solution (P-8).
(Production Example 5) TCA / PDA
In a 500 mL four-necked flask, 21.6 g of PDA and 369 g of NMP were added and dissolved, and 43.5 g of TCA was added. The mixture was reacted at 50 ° C. for 24 hours under a nitrogen atmosphere to prepare a polymer solution (P-9). This polymer had a number average molecular weight of 12,700 and a weight average molecular weight of 24,300.
400 g of NMP and 200 g of BCS were added to 400 g of the obtained polymer solution (P-9), and the mixture was stirred at room temperature for 2 hours to obtain a polymer solution (P-10).
[Liquid crystal aligning agent]

(Examples 1, 3, 5, 7, 9, 10, 11, 12)
In a 100 mL eggplant flask, 20.0 g of each polymer solution (P-3, P-6, P-8 or P-10) shown in Table 1 below, compound (M1, M2, M3 or M4) Was added and stirred for 1 hour to obtain liquid crystal alignment treatment agents (C1, C3, C5, C7, C9, C10, C11, C12), respectively.
(Examples 2 and 4)
In a 100 mL eggplant flask, 20.0 g of the polymer solution P-6 described above and 0.036 g of the compound (M1 or M3) shown in Table 1 below were added and stirred for 1 hour, whereby a liquid crystal alignment treatment agent ( C2, C4) were obtained.
(Example 6)
In a 100 mL eggplant flask, 20.0 g of the above polymer solution P-3 and 0.12 g of compound M2 shown in Table 1 below were added and stirred for 1 hour to obtain a liquid crystal aligning agent (C6). .
(Example 8)
In a 100 mL eggplant flask, 20.0 g of the above polymer solution P-3 and 0.012 g of compound M2 shown in Table 1 below were added and stirred for 1 hour to obtain a liquid crystal aligning agent (C8). .

(Comparative Example 1)
In a 100 mL eggplant flask, 20.0 g of polymer solution P-3 and 0.06 g of triphenylamine (hereinafter referred to as TPA) were added and stirred for 1 hour to obtain a liquid crystal aligning agent C13.

<Production of liquid crystal cell>
(Example 13)
A liquid crystal alignment treatment agent C1 shown in Table 1 was spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 80 ° C. for 70 seconds, and then baked on a hot plate at 235 ° C. for 10 minutes to obtain a film thickness of 100 nm. The coating film was formed. This coating film surface was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film.
Prepare two substrates with the above-mentioned liquid crystal alignment film, spray a 6 μm spacer on the surface of one liquid crystal alignment film, print a sealant on the surface, and place the other substrate on the liquid crystal alignment film surface. After laminating so that the facing rubbing direction was orthogonal, the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (C080) (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

The method for measuring the characteristics of each liquid crystal cell produced and the UV irradiation method are described below.
<Measurement of accumulated charge (RDC)>
A DC voltage was applied to the twisted nematic liquid crystal cell manufactured by the method described in <Preparation of Liquid Crystal Cell> at a temperature of 23 ° C. up to 1.0 V at intervals of 0 V to 0.1 V, and the flicker amplitude at each voltage. Levels were measured and a calibration curve was created. After grounding for 5 minutes, after applying AC voltage 3.0V and DC voltage 5.0V for 1 hour, measure the flicker amplitude level immediately after setting only DC voltage to 0V, and compare it with the calibration curve prepared in advance. Estimated. (This RDC estimation method is called a flicker reference method.)
Here, the time until the RDC value decreased by 50% from the RDC value immediately after the direct-current voltage of 5.0 V was applied for 1 hour was defined as the RDC improvement time. When the cell produced in Example 13 was evaluated, the RDC improvement time was 0.35 sec.

<UV irradiation>
The twisted nematic liquid crystal cell produced by the method described in <Preparation of Liquid Crystal Cell> was irradiated with light for 167 sec using a tabletop UV curing device HCT3B28HEX-1 manufactured by Sen Special Light Source. At that time, when the illuminance was measured using a luminometer (UV Light MEASUREMODEL UV-M02 manufactured by CRC) and a UV-35 sensor, the illuminance was 60.0 mW / cm ² .
<Measurement of voltage holding ratio (VHR)>
The measurement of the voltage holding ratio of the twisted nematic liquid crystal cell processed by the above <UV irradiation> method was performed by applying a voltage of 4 V for 60 μs at a temperature of 90 ° C., measuring the voltage after 16.67 msec, It was calculated as a voltage holding ratio how much it was able to hold. For measuring the voltage holding ratio, a VHR-1 voltage holding ratio measuring device manufactured by Toyo Corporation was used.
When the cell produced in Example 1 was evaluated, the voltage holding ratio was 47%.

(Examples 14 to 16 and Comparative Example 2)
In the same manner as in Example 13, a twisted nematic liquid crystal cell was produced using the liquid crystal aligning agent shown in Table 2 and the polymer solution composed of P-6. For each liquid crystal cell, the RDC improvement time and VHR after UV treatment were evaluated. The results are shown in Table 2.

(Examples 17 to 24 and Comparative Examples 3 and 4)
A twisted nematic liquid crystal cell was produced in the same manner as in Examples 13 to 16, respectively. About each produced liquid crystal cell, RDC improvement time and rubbing tolerance were evaluated. The results are shown in Table 3.
In addition, rubbing tolerance evaluation was evaluated as follows.

<Rubbing resistance evaluation>
As a verification test for rubbing resistance, rubbing was performed under the condition that the indentation amount was changed to 0.5 mm, and the film surface was observed with a confocal laser microscope. Evaluation was performed as follows.
○: No scrap residue is observed.
X: Scraping residue is observed.

Since the liquid crystal aligning agent of the present invention can shorten the time until the afterimage generated by the direct current voltage disappears, improves the UV resistance, and does not reduce the shaving characteristics, the TN element, STN element, TFT liquid crystal element, Furthermore, it is widely useful for forming a liquid crystal alignment film in a vertical alignment type liquid crystal display element or the like.
It should be noted that the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2011-118371 filed on May 26, 2011 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (8)

At least one polymer selected from the group consisting of a polyimide precursor and polyimide, and a compound represented by the following formula [1] (wherein R ₁ represents a hydrogen atom or a vinyl group, and n represents 0 to 2). A liquid crystal aligning agent characterized by containing an integer).

  The compound represented by the formula [1] is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of at least one polymer selected from the group consisting of a polyimide precursor and a polyimide. The liquid crystal aligning agent of description. R ₁ in the formula [1] is a vinyl group, a liquid crystal alignment treating agent according to claim 1 or 2. The compound represented by Formula [1] is the following M1, M2, M3, or M4, The liquid crystal aligning agent in any one of Claims 1-3.

  The liquid-crystal aligning agent in any one of Claims 1-4 containing 0.5-10 mass% of solid content.   The liquid crystal aligning film obtained from the liquid-crystal aligning agent in any one of Claims 1-5.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 6. A compound represented by the following formula [2] (wherein n represents an integer of 0 to 2).