WO2014133043A1

WO2014133043A1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: WO2014133043A1
Application number: PCT/JP2014/054767
Authority: WO
Inventors: 奈穂菊池; 大輔佐久間; 幸司巴
Original assignee: 日産化学工業株式会社
Priority date: 2013-02-28
Filing date: 2014-02-26
Publication date: 2014-09-04
Also published as: JP6264577B2; CN105190415A; TWI617622B; KR20200103879A; CN105190415B; KR102470287B1; KR20150122209A; JPWO2014133043A1; TW201500463A

Abstract

Provided is a liquid crystal alignment agent that contains at least one polymer chosen from among a polyimide precursor and a polyimide obtained by imidization of the polyimide precursor, the polyimide precursor being obtained by reacting a diamine component with a tetracarboxylic acid component that includes a tetracarboxylic acid dianhydride represented by formula [1] and an aliphatic tetracarboxylic acid dianhydride represented by formula [2]. (In formula [2], Z¹ is at least one tetravalent group chosen from formulas [2a] through [2j].) (In formula [2a], Z² through Z⁵ indicate a chlorine atom, a methyl group, a nitrogen atom, or a benzene ring, each of which can be the same or different; and in formula [2g], Z⁶ and Z⁷ indicate a hydrogen atom or a methyl group, each of which can be the same or different.)

Description

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment treatment agent used in the production of a liquid crystal display element, a liquid crystal alignment film obtained from the liquid crystal alignment treatment agent, and a liquid crystal display element using the liquid crystal alignment film.

Currently, as a liquid crystal alignment film of a liquid crystal display element, a so-called polyimide liquid crystal alignment film obtained by applying and baking a liquid crystal alignment treatment agent mainly composed of a polyimide precursor such as polyamic acid or a soluble polyimide solution is mainly used. ing.

The liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal. However, as liquid crystal display elements have become higher in definition, the liquid crystal alignment film used in the liquid crystal alignment film has a high voltage holding ratio and a direct current voltage from the viewpoint of suppressing the decrease in contrast of the liquid crystal display elements and reducing the afterimage phenomenon. The characteristic that the accumulated charge when applied is small or the charge accumulated by the DC voltage is quickly relaxed has become increasingly important.

In a polyimide-based liquid crystal alignment film, a liquid crystal alignment treatment agent containing a tertiary amine with a specific structure in addition to polyamic acid or imide group-containing polyamic acid is used as a short time until the afterimage generated by direct current voltage disappears. (For example, refer to Patent Document 1), and those using a liquid crystal alignment treatment agent containing a soluble polyimide using a specific diamine having a pyridine skeleton as a raw material (for example, refer to Patent Document 2). In addition to polyamic acid and its imidized polymer, a compound containing one carboxylic acid group in the molecule, assuming that the voltage holding ratio is high and the time until the afterimage generated by direct current voltage disappears is short , Using a liquid crystal aligning agent containing a very small amount of a compound selected from a compound containing one carboxylic anhydride group in the molecule and a compound containing one tertiary amino group in the molecule (for example, Patent Document 3) is known.

JP-A-9-316200 JP-A-10-104633 JP-A-8-076128

With the recent improvement in performance of liquid crystal display elements, liquid crystal display elements are used for large-screen, high-definition liquid crystal televisions and in-vehicle applications such as car navigation systems and meter panels. In such applications, in order to obtain high luminance, a backlight with a large calorific value may be used. For this reason, the liquid crystal alignment film is required to have high reliability from another point of view, that is, high stability to light from the backlight. In particular, when the voltage holding ratio, which is one of the electrical characteristics of the liquid crystal display element, is reduced by light irradiation from the backlight, a burn-in defect (also called line burn-in), which is one of the display defects of the liquid crystal display element. There is a problem that occurs.

Therefore, in the liquid crystal alignment film, in addition to good initial characteristics, for example, it is required that the voltage holding ratio is hardly lowered even after being exposed to light irradiation for a long time.

Therefore, the present invention has a liquid crystal alignment treatment agent, a liquid crystal alignment film, and the liquid crystal alignment film for obtaining a liquid crystal alignment film excellent in light resistance that can suppress a decrease in voltage holding ratio even after long-time light irradiation. An object is to provide a liquid crystal display element.

As a result of intensive studies, the present inventor has obtained a polyimide precursor obtained by reacting a tetracarboxylic acid component containing two types of tetracarboxylic dianhydrides having a specific structure with a diamine component, and the polyimide precursor. The present inventors have found that a liquid crystal aligning agent containing at least one polymer selected from polyimides obtained by imidizing is extremely effective for achieving the above object, and has completed the present invention.

That is, the present invention has the following gist.
(1) It is obtained by reacting a tetracarboxylic acid component containing a tetracarboxylic dianhydride represented by the following formula [1] and a tetracarboxylic dianhydride represented by the following formula [2] with a diamine component. A liquid crystal aligning agent comprising a polyimide precursor and at least one polymer selected from polyimides obtained by imidizing the polyimide precursor.

(In the formula [2], Z ¹ is at least one tetravalent group selected from the following formulas [2a] to [2j].)

(In the formula [2a], Z ² to Z ⁵ represent a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different. In the formula [2g], Z ⁶ and Z ⁷ are A hydrogen atom or a methyl group, which may be the same or different.

(2) The liquid crystal aligning agent as described in (1) above, which contains N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone as a solvent in the liquid crystal aligning agent .

(3) The solvent described in (1) or (2) above, which contains a solvent selected from the following formulas [D-1] to [D-3] as a solvent in the liquid crystal aligning agent Liquid crystal alignment treatment agent.

(In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and the formula [D-3 D ³ represents an alkyl group having 1 to 4 carbon atoms.

(4) A liquid crystal alignment film obtained by using the liquid crystal aligning agent described in (1) to (3) above.

(5) A liquid crystal alignment film obtained by an ink jet method using the liquid crystal aligning agent described in (1) to (3) above.

(6) A liquid crystal display element comprising the liquid crystal alignment film according to (4) or (5).

According to the liquid crystal aligning agent of the present invention, even when exposed to light irradiation for a long time, a decrease in voltage holding ratio can be suppressed, and a liquid crystal alignment film having excellent light resistance can be obtained. Therefore, the liquid crystal display element having the liquid crystal alignment film obtained from 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 liquid crystal aligning agent of the present invention comprises a tetracarboxylic dianhydride represented by the following formula [1] (also referred to as a specific tetracarboxylic dianhydride) and an aliphatic tetracarboxylic acid represented by the following formula [2]. Selected from a polyimide precursor obtained by reacting a diamine component with a tetracarboxylic acid component containing a dianhydride (also referred to as a specific aliphatic tetracarboxylic dianhydride) and a polyimide obtained by imidizing the polyimide precursor Containing at least one polymer (also referred to as a specific polymer).

Here, the diamine component is a diamine compound having two primary or secondary amino groups in the molecule. The polyimide precursor refers to polyamic acid or polyamic acid alkyl ester.

<Specific tetracarboxylic dianhydride>
The tetracarboxylic acid component which is a raw material of the specific polymer contained in the liquid crystal aligning agent of the present invention includes two types of tetracarboxylic dianhydrides. One type of tetracarboxylic dianhydride is a specific tetracarboxylic dianhydride represented by the following formula [1].

The specific tetracarboxylic dianhydride represented by the formula [1] is a tetracarboxylic acid, a tetracarboxylic acid dihalide compound, a tetracarboxylic acid dialkyl ester compound or a tetracarboxylic acid dialkyl ester dihalide compound (all Can also be referred to as a specific tetracarboxylic acid component).

The specific tetracarboxylic dianhydride represented by the formula [1] is preferably 20 mol% to 80 mol% in the total tetracarboxylic acid component. In particular, the content is preferably 20 mol% to 60 mol%. Particularly preferred is 20 to 50 mol%.

<Specific aliphatic tetracarboxylic dianhydride>
The tetracarboxylic acid component which is a raw material of the specific polymer contained in the liquid crystal aligning agent of the present invention includes two types of tetracarboxylic dianhydrides. The other type of tetracarboxylic dianhydride is a specific aliphatic tetracarboxylic dianhydride represented by the following formula [2].

In the formula [2], Z ¹ is at least one tetravalent group selected from the following formulas [2a] to [2j].

In the formula [2a], Z ² to Z ⁵ represent a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different.

In the formula [2g], Z ⁶ and Z ⁷ represent a hydrogen atom or a methyl group, and may be the same or different.

In the structure represented by the formula [2], Z ¹ is represented by the formula [2a], the formula [2c], the formula [2d], from the viewpoint of ease of synthesis and polymerization reactivity when producing a polymer. A structure represented by the formula [2e], the formula [2f] or the formula [2g] is preferable. A structure represented by formula [2a], formula [2e], formula [2f] or formula [2g] is more preferable, and formula [2e], formula [2f] or formula [2g] is particularly preferable. It is.

The specific aliphatic tetracarboxylic dianhydride represented by the formula [2] is a tetracarboxylic acid, tetracarboxylic acid dihalide compound, tetracarboxylic acid dialkyl ester compound or tetracarboxylic acid dialkyl ester dihalide compound which is a tetracarboxylic acid derivative thereof. (All are collectively referred to as a specific aliphatic tetracarboxylic acid component) can also be used.

The specific aliphatic tetracarboxylic dianhydride represented by the formula [2] is preferably 20 mol% to 80 mol% in the total tetracarboxylic acid component. Particularly preferred is 20 to 60 mol%.

In addition, the specific aliphatic tetracarboxylic dianhydride is the solubility of the specific polymer contained in the liquid crystal aligning agent of the present invention in the solvent, the coating property of the liquid crystal aligning agent, and the liquid crystal alignment film when used as a liquid crystal alignment film. One type or a mixture of two or more types can be used depending on the properties such as orientation, voltage holding ratio, and accumulated charge.

<Other tetracarboxylic acid compounds>
As long as the tetracarboxylic acid component in the specific polymer contained in the liquid crystal aligning agent of the present invention does not impair the effects of the present invention, the tetracarboxylic acid component other than the specific tetracarboxylic dianhydride and the specific aliphatic tetracarboxylic dianhydride Carboxylic acid compounds (also referred to as other tetracarboxylic acid compounds) can also be used.

Specific examples thereof include the following tetracarboxylic dianhydrides, tetracarboxylic acid compounds or dicarboxylic acid dihalide compounds.

That is, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6 , 7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic 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) Nyl) propane, 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 or 1,3-diphenyl-1,2,3 4-cyclobutanetetracarboxylic acid.

Other tetracarboxylic acid compounds are the solubility of the specific polymer contained in the liquid crystal aligning agent of the present invention in the solvent, the coating property of the liquid crystal aligning agent, the liquid crystal alignment when used as a liquid crystal alignment film, and the voltage holding ratio. Depending on the characteristics such as accumulated charge, one kind or a mixture of two or more kinds may be used.

<Diamine component>
As the diamine component for producing the specific polymer contained in the liquid crystal aligning agent of the present invention, a known diamine compound can be used.

Among them, it is preferable to use a diamine compound having a structure represented by the following formula [3].

In the formula [3], Y represents the following formula [3-1], formula [3-2], formula [3-3], formula [3-4], formula [3-5] or formula [3-6] At least one monovalent group selected from the above: m represents an integer of 1 to 4, and — (Y) _m represents _m substituents Y.

In the formula [3-1], a represents an integer of 0 to 4. Especially, the integer of 0 or 1 is preferable from the point of the availability of a raw material or the ease of a synthesis | combination.

In the formula [3-2], b represents an integer of 0 to 4. Especially, the integer of 0 or 1 is preferable from the point of the availability of a raw material or the ease of a synthesis | combination.

In the formula [3-3], Y ¹ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or —OCO—. Indicates. Among these, from the viewpoint of availability of raw materials and ease of synthesis, a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CH ₂ O— or —COO -Is preferred. More preferred is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 10), —O—, —CH ₂ O— or —COO—.

In the formula [3-3], Y ² represents a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15). Among these, a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 10) is preferable.

In the formula [3-3], Y ³ is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or —OCO—. Indicates. Of these, a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O— or —COO— is preferable from the viewpoint of ease of synthesis. More preferred is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —CH ₂ O— or —COO—.

In the formula [3-3], Y ⁴ is a divalent cyclic group selected from a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms. And an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms, or a fluorine atom. Furthermore, Y ⁴ may be a divalent organic group selected from organic groups having 12 to 25 carbon atoms having a steroid skeleton. Among these, an organic group having 17 to 51 carbon atoms having a benzene ring, a cyclohexane ring or a steroid skeleton is preferable from the viewpoint of ease of synthesis.

In the formula [3-3], Y ⁵ represents a divalent cyclic group selected from a benzene ring, a cyclohexane ring or a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms. And an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms, or a fluorine atom. Of these, a benzene ring or a cyclohexane ring is preferable.

In the formula [3-3], n represents an integer of 0 to 4. Among these, an integer of 0 to 3 is preferable from the viewpoint of availability of raw materials and ease of synthesis. More preferred is an integer of 0-2.

In the formula [3-3], Y ⁶ represents an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms. Indicates. Of these, an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 10 carbon atoms is preferable. More preferably, it is an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. Particularly preferred is an alkyl group having 1 to 9 carbon atoms or an alkoxyl group having 1 to 9 carbon atoms.

As a preferred combination of Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , Y ⁶ and n in the formula [3-3] for constituting the substituent Y in the formula [3], International Publication WO2011 The same combinations as (2-1) to (2-629) listed in Tables 6 to 47 of the 13th to 34th items of / 132751 can be mentioned. In each table of the International Publication, Y ¹ to Y ⁶ in the present invention are shown as Y ¹ to Y ⁶ , but Y ¹ to Y ⁶ are read as Y ¹ to Y ⁶ . Further, an organic group having 12 to 25 carbon atoms having a steroid skeleton is read as an organic group having 17 to 51 carbon atoms having a steroid skeleton.

In the formula [3-4], Y ⁷ represents —O—, —CH ₂ O—, —COO—, —OCO—, —CONH— or —NHCO—. Of these, —O—, —CH ₂ O—, —COO— or —CONH— is preferable. More preferred is —O—, —COO— or —CONH—.

In the formula [3-4], Y ⁸ represents an alkyl group having 8 to 22 carbon atoms.

In the formula [3-5], Y ⁹ and Y ¹⁰ each independently represent a hydrocarbon group having 1 to 12 carbon atoms.

In the formula [3-6], Y ¹¹ represents an alkyl group having 1 to 5 carbon atoms.

The method for producing the diamine compound represented by the formula [3] is not particularly limited, but preferred methods include those shown below. As an example, the diamine compound represented by the formula [3] can be obtained by synthesizing a dinitro compound represented by the following formula [3-A] and further reducing the nitro group to convert it to an amino group.

(In Formula [3-A], Y represents Formula [3-1], Formula [3-2], Formula [3-3], Formula [3-4], Formula [3-5], or Formula [3]. And at least one substituent selected from -6], m represents an integer of 1 to 4.

The method for reducing the dinitro group of the dinitro compound represented by the formula [3-A] is not particularly limited, and is usually palladium-carbon in a solvent such as ethyl acetate, toluene, tetrahydrofuran, dioxane or an alcohol solvent, There is a method in which platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, or the like is used as a catalyst and reacted in hydrogen gas, hydrazine, or hydrogen chloride.

Hereinafter, specific structures of the diamine compound represented by the formula [3] are listed, but the structure is not limited to these examples.

That is, examples of the diamine compound represented by the formula [3] include 2,4-dimethyl-m-phenylenediamine, 2,6-diaminotoluene, 2,4-diaminobenzoic acid, 3,5-diaminobenzoic acid, 2, In addition to 4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, and 4,6-diaminoresorcinol, the following formulas [3-7] to [3- 47] can be mentioned.

(In the formulas [3-7] to [3-10], A ¹ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

(In the formulas [3-35] to [3-37], R ¹ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ — or CH ₂ OCO—, and R ² represents carbon Represents an alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group of formula 1 to 22.)

(In the formulas [3-38] to [3-40], R ³ represents —COO—, —OCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ — or — CH ₂ — and R ⁴ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

(In the formulas [3-41] and [3-42], R ⁵ represents —COO—, —OCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, — CH ₂ — or —O—, and R ⁶ 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 the formulas [3-43] and [3-44], R ⁷ represents an alkyl group having 3 to 12 carbon atoms. Note that the cis-trans isomerism of 1,4-cyclohexylene is the trans isomer. preferable.)

(In the formulas [3-45] and [3-46], R ⁸ represents an alkyl group having 3 to 12 carbon atoms. Note that the cis-trans isomerism of 1,4-cyclohexylene is the trans isomer. preferable.)

(In the formula [3-47], B ⁴ represents an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and B ³ represents a 1,4-cyclohexylene group or a 1,4-phenylene group. B ² represents an oxygen atom or —COO— * (where a bond marked with “*” binds to B ³ ), and B ¹ represents an oxygen atom or —COO— * (where “*” bond marked with represents a _(CH 2) bind to ^{a 2).} Further, ^{a 1} represents an integer of 0 or 1, ^{a 2} represents an integer of 2 ~ 10, ^{a 3} is 0 or 1 Indicates an integer.)

Among the diamine compounds represented by the formula [3], the liquid crystal aligning agent obtained from the specific polymer using the diamine compound having the structure in which the substituent Y in the formula [3] is represented by the formula [3-3] When the liquid crystal alignment film is used, the pretilt angle of the liquid crystal can be increased. At that time, for the purpose of enhancing these effects, among the above diamine compounds, diamines represented by the formulas [3-25] to [3-40] or the formulas [3-43] to [3-47] are used. It is preferable to use a compound. More preferred are diamine compounds represented by the formulas [3-29] to [3-40] or the formulas [3-43] to [3-47]. Moreover, in order to improve these effects, it is preferable that these diamine compounds are 5 mol% or more and 80 mol% or less of the whole diamine component. More preferably, these diamine compounds are 5 mol% or more and 60 mol% or less of the whole diamine component from the viewpoint of the coating properties of the composition and the liquid crystal alignment treatment agent and the electric characteristics as the liquid crystal alignment film.

The diamine compound represented by the formula [3] is the solubility and coating property of the specific polymer contained in the liquid crystal aligning agent of the present invention in the solvent, the alignment property of the liquid crystal when the liquid crystal alignment film is used, and the voltage holding ratio. Depending on characteristics such as accumulated charge, one kind or a mixture of two or more kinds can be used.

As the diamine component for producing the specific polymer contained in the liquid crystal aligning agent of the present invention, a diamine compound other than the diamine compound represented by the formula [3] (also referred to as other diamine compound) can be used. Specific examples of other diamine compounds are shown below, but are not limited to these examples.

For example, m-phenylenediamine, p-phenylenediamine, 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′-diaminobiphenyl, 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'-diaminodiphenyl Tan, 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'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis (4-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'-diamy Diphenylamine, N-methyl (4,4'-diaminodiphenyl) amine, N-methyl (3,4'-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-diaminonaphthalene, 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-aminophenyl) methane, 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 ′-[ , 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-phenylenebis [(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) iso Phthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N ′-(1,3-phenylene) 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) Enyl) 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-aminophenyl) 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, 1,3-bis (4-aminophenoxy) propane, 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-amino) Phenoxy) 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-aminophenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane, bis ( 4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, , 7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane or 1,12-diaminododecane.

Examples of other diamine compounds include those having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring or a heterocyclic ring in the diamine side chain, and those having a macrocyclic substituent composed of these. . Specifically, diamine compounds represented by the following formulas [DA1] to [DA7] can be exemplified.

(In the formulas [DA1] to [DA6], A ¹ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO— or —NH—, A ² represents a linear or branched alkyl group having 1 to 22 carbon atoms or a linear or branched fluorine-containing alkyl group having 1 to 22 carbon atoms.

(In the formula [DA7], p represents an integer of 1 to 10)

In addition, as long as the effects of the present invention are not impaired, diamine compounds represented by the following formulas [DA8] to [DA13] can also be used as other diamine compounds.

(In the formula [DA10], m represents an integer of 0 to 3, and in the formula [DA13], n represents an integer of 1 to 5.)

Furthermore, as long as the effects of the present invention are not impaired, diamine compounds represented by the following formulas [DA14] to [DA17] can also be used as other diamine compounds.

(In the formula [DA14], A ¹ is a single bond, —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —O —, —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ —, —COO—, —OCO—, —CON (CH ₃ ) — Or —N (CH ₃ ) CO—, each of m ¹ and m ² represents an integer of 0 to 4, and m ¹ + m ² represents an integer of 1 to 4, and in the formula [DA15], m ³ and m ⁴ each represent an integer of 1 to 5, and in formula [DA16], A ² represents a linear or branched alkyl group having 1 to 5 carbon atoms, m ⁵ represents an integer of 1 to 5, [DA17] in, ^{A 3} is a single _{_{_{bond, -CH 2 -, - C 2}}} H 4 -, - C (CH 3) 2 -, - CF 2 -, - C (CF 3 _{_{2 -, - O -, -}} CO -, - NH -, - N (CH 3) -, - CONH -, - NHCO -, - CH 2 O -, - OCH 2 -, - COO -, - OCO-, Represents —CON (CH ₃ ) — or —N (CH ₃ ) CO—, and m ⁶ represents an integer of 1 to 4.

In addition, diamine compounds represented by the following formula [DA18] and formula [DA19] can also be used as other diamine compounds.

The other diamine compounds exemplified above include the solubility of the specific polymer contained in the liquid crystal alignment treatment agent of the present invention in the solvent, the coating property of the composition, the alignment property of the liquid crystal when used as a liquid crystal alignment film, and the voltage holding ratio. Depending on the characteristics such as accumulated charge, one kind or a mixture of two or more kinds may be used.

<Specific polymer>
The specific polymer contained in the liquid crystal aligning agent of the present invention includes a specific tetracarboxylic acid component containing a specific tetracarboxylic dianhydride represented by the formula [1] and a specific aliphatic represented by the formula [2]. At least one heavy selected from a polyimide precursor obtained by reacting a specific aliphatic tetracarboxylic acid component containing tetracarboxylic dianhydride and the diamine component and a polyimide obtained by imidizing the polyimide precursor. It is a coalescence.

Moreover, the polyimide precursor obtained by reacting the specific aliphatic tetracarboxylic acid component and the diamine component has a structure represented by the following formula [A], for example.

(In the formula [A], R ¹ is a tetravalent organic group derived from a specific aliphatic tetracarboxylic acid component, R ² is a divalent organic group derived from a diamine component, and A ¹ and A ² are A hydrogen atom or an alkyl group having 1 to 8 carbon atoms, which may be the same or different, and A ³ and A ^{4 each} represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an acetyl group, and the same Or n may be different, and n represents a positive integer.)

The specific polymer contained in the liquid crystal aligning agent of the present invention includes a specific tetracarboxylic dianhydride represented by the formula [1] and a specific aliphatic tetracarboxylic dianhydride represented by the following formula [B]. And a diamine compound represented by the following formula [C] as a raw material, the polyamic acid comprising the structural formula of the repeating unit represented by the following formula [D] Polyimide obtained by imidizing polyamic acid is preferable. The specific tetracarboxylic dianhydride represented by the formula [B] is the same as the specific aliphatic tetracarboxylic dianhydride represented by the formula [2]. In this case, R ¹ in the formula [B] is the same tetravalent group as Z ¹ in the formula [2].

(In Formula [B] and Formula [C], R ¹ and R ² have the same meaning as defined in Formula [A].)

(In formula [D], R ¹ and R ² have the same meaning as defined in formula [A].)

In addition, the polymer of the formula [D] obtained above is added to the alkyl group having 1 to 8 carbon atoms of A ¹ and A ^{2 represented by} the formula [A] and the formula [A] by a usual synthesis method. It is also possible to introduce an alkyl group having 1 to 5 carbon atoms or an acetyl group of A ³ and A ⁴ shown.

<Method for producing specific polymer>
In the present invention, the specific polymer includes a tetracarboxylic acid component including the specific tetracarboxylic dianhydride represented by the formula [1] and the specific aliphatic tetracarboxylic dianhydride represented by the formula [2]; Obtained by reacting with a diamine component. Specifically, a specific tetracarboxylic dianhydride, a specific aliphatic tetracarboxylic dianhydride, and a diamine component are polycondensed to obtain a polyamic acid, and the tetracarboxylic acid component and the diamine component are dehydrated. A method of obtaining polyamic acid by polycondensation or polycondensation is used.

Polyamide acid alkyl ester can be obtained by polycondensation of carboxylic acid group with dialkyl esterified tetracarboxylic acid and diamine component, tetracarboxylic acid dihalide with carboxylic acid group dialkylesterified and diamine component. A method or a method of converting a carboxyl group of a polyamic acid into an ester is used.

In order to obtain polyimide, a method is used in which the polyamic acid or polyamic acid alkyl ester is cyclized to form polyimide.

The reaction between the diamine component and the tetracarboxylic acid component is usually carried out with the diamine component and the tetracarboxylic acid component in an organic solvent. The organic solvent used at that time is not particularly limited as long as the produced polyimide precursor is dissolved. Although the specific example of the organic solvent used for reaction below is given, it is not limited to these examples.

For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone , Cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and solvents represented by the following formulas [D-1] to [D-3].

These may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polyimide precursor, you may mix and use the said solvent in the range which the produced | generated polyimide precursor does not precipitate. Moreover, since the water | moisture content in an organic solvent inhibits a polymerization reaction, and also causes the produced polyimide precursor to hydrolyze, it is preferable to use what dehydrated and dried the organic solvent.

When the diamine component and the tetracarboxylic acid 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 acid component is dispersed or dissolved in the organic solvent as it is. And a method of adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic acid component in an organic solvent, a method of alternately adding a diamine component and a tetracarboxylic acid component, etc. Any of these methods may be used. In addition, when reacting using a plurality of diamine components or tetracarboxylic acid components, they may be reacted in a premixed state, individually or sequentially, or further individually reacted low molecular weight substances. May be mixed and reacted to form a polymer. In this case, the polymerization temperature 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. It becomes. Therefore, it 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 polyimide precursor, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably 0.8 to 1.2. Similar to a normal polycondensation reaction, the molecular weight of the polyimide precursor produced increases as the molar ratio approaches 1.0.

The polyimide constituting the specific polymer contained in the liquid crystal aligning agent of the present invention is a polyimide obtained by ring-closing the polyimide precursor. In this polyimide, the ring closure rate (also referred to as imidization rate) of the amic acid group. ) Does not necessarily have to be 100%, and can be arbitrarily adjusted according to the application and purpose.

Examples of the method for imidizing the polyimide precursor include thermal imidization in which the polyimide precursor solution is heated as it is or catalytic imidization in which a catalyst is added to the polyimide precursor solution.

When the polyimide precursor is thermally imidized in a solution, the temperature 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 catalyst imidation of the polyimide precursor can be performed by adding a basic catalyst and an acid anhydride to the polyimide precursor 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, and trioctylamine. Among them, pyridine is preferable because it has a basicity appropriate for advancing 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 recovering the produced polyimide precursor or polyimide from the polyimide precursor or polyimide reaction solution, the reaction solution may be poured into a solvent and precipitated. Examples of the solvent used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated in the solvent can be collected by filtration, and then 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 solvent at this time include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more kinds of solvents selected from these because purification efficiency is further increased.

The molecular weight of the specific polymer contained in the liquid crystal aligning agent of the present invention is determined by the GPC (Gel Permeation Chromatography) method in consideration of the strength of the liquid crystal alignment film obtained therefrom, the workability during film formation, and the coating properties. The measured weight average molecular weight is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal alignment agent>
The liquid crystal aligning agent of the present invention is a coating solution for forming a liquid crystal alignment film, which contains a polymer component and a solvent and is a coating solution for forming a polymer film.

And as above-mentioned, the liquid-crystal aligning agent of this invention is the above-mentioned specific polymer, ie, the specific tetracarboxylic dianhydride shown by said Formula [1], and said formula [1] as a polymer component. 2], a polyimide precursor obtained by reacting a tetracarboxylic acid component (specific tetracarboxylic acid component and specific aliphatic tetracarboxylic acid component) containing the specific aliphatic tetracarboxylic dianhydride and the diamine component, and It contains at least one polymer selected from polyimides obtained by imidizing the polyimide precursor. By using a liquid crystal aligning agent containing such a specific polymer, a liquid crystal alignment film having excellent light resistance and excellent voltage holding characteristics (voltage holding ratio) can be obtained. The reason for this will be described below.

The specific tetracarboxylic dianhydride has a structure in which two dicarboxylic dianhydrides are bonded by a methylene group. Since a methylene group is flexible, a polyimide precursor obtained by reacting a specific tetracarboxylic dianhydride having such a methylene group, a specific aliphatic tetracarboxylic dianhydride, and a diamine component. Alternatively, polyimide is considered to be pseudo-crosslinked between molecules and within molecules due to the flexibility of the methylene group. As a result, the specific polymer is polymerized and the density is increased. The liquid crystal alignment film having a specific polymer having a high density becomes a dense film, and as shown in the examples described later, the decrease in voltage holding ratio is suppressed even after irradiation with strong ultraviolet rays, and the film has excellent light resistance. Become.

In general, an aromatic acid anhydride is weak in light resistance, but a specific tetracarboxylic dianhydride has a flexible methylene group as described above, and thus a liquid crystal alignment film having a specific polymer. The light resistance is not lowered, and the voltage holding ratio can be kept high.

Such excellent voltage holding characteristics can be further improved by using a specific aliphatic tetracarboxylic dianhydride that is not aromatic together with a specific tetracarboxylic dianhydride having a methylene group as a raw material of the specific polymer. Can be increased.

As a result, two types of tetracarboxylic dianhydrides, the specific tetracarboxylic dianhydride and the specific aliphatic tetracarboxylic dianhydride, are used as the raw material for the specific polymer contained in the liquid crystal alignment treatment agent of the present invention. Thus, a liquid crystal alignment film having excellent light resistance and excellent voltage holding characteristics can be obtained.

All the polymer components in the liquid crystal aligning agent of the present invention may be all specific polymers, or other polymers may be mixed. In that case, the content of the other polymer is 0.5 mass% to 15 mass%, preferably 1 mass% to 10 mass% of the specific polymer. As other polymers, polyimide precursors not using the specific tetracarboxylic dianhydride represented by the formula [1] and the specific aliphatic tetracarboxylic dianhydride represented by the formula [2] are used. Or a polyimide is mentioned. Furthermore, an acrylic polymer, a methacrylic polymer, polystyrene, polyamide, polysiloxane, etc. are mentioned.

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. If the solid content concentration is less than 0.5% by mass, it is difficult to form a uniform and defect-free coating film, and if it exceeds 10% by mass, the storage stability of the solution may be deteriorated. The term “solid content” as used herein refers to a component obtained by removing the solvent from the liquid crystal aligning agent, and means the above-described specific polymer, other polymers, and various additives described later.

The solvent in the liquid crystal aligning agent of the present invention is preferably 70 to 99.9% by mass of the solvent in the liquid crystal aligning agent from the viewpoint of forming a uniform liquid crystal aligning film by coating. This content can be appropriately changed depending on the film thickness of the target liquid crystal alignment film.

The solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is a solvent (also referred to as a good solvent) that dissolves the specific polymer. Although the specific example of a good solvent is given to the following, it is not limited to these examples.

For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone Cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone. Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, the solvents represented by the above formulas [D-1] to [D-3], and the like can be given. These may be used alone or in combination.

Of these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and γ-butyrolactone are preferably used. Furthermore, when the solubility of the specific polymer in the solvent is high, it is preferable to use the solvents represented by the formulas [D-1] to [D-3].

The good solvent in the liquid crystal aligning agent of the present invention is preferably 10 to 100% by mass of the total solvent contained in the liquid crystal aligning agent. Of these, 20 to 90% by mass is preferable. More preferred is 30 to 80% by mass.

The liquid crystal aligning agent of the present invention uses a solvent (also referred to as a poor solvent) that improves the coating properties and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied unless the effects of the present invention are impaired. be able to. Although the specific example of a poor solvent is given to the following, it is not limited to these examples.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2- Ethane All, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1 , 2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, -Heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene Carbonate, 2- (methoxymethoxy) ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1 -(Butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol , Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol Diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, Methyl lactate, ethyl lactate, methyl acetate, acetic acid Chill, 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, methyl lactate, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester or the above formula [D-1 ] To a solvent represented by the formula [D-3].

Among them, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether or ethylene glycol monobutyl ether, or the above-mentioned formulas [D-1] to [D-3] It is preferable to use a solvent represented by

These poor solvents are preferably 1 to 70% by mass of the whole solvent contained in the liquid crystal aligning agent. Among these, 1 to 60% by mass is preferable. More preferred is 5 to 60% by mass.

The liquid crystal aligning agent of the present invention comprises a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group, unless the effects of the present invention are impaired. A crosslinkable compound having at least one substituent selected from the group or a crosslinkable compound having a polymerizable unsaturated bond may be contained. It is necessary to have two or more of these substituents and polymerizable unsaturated bonds in the crosslinkable compound.

Examples of the crosslinkable compound having an epoxy group or an isocyanate group include bisphenolacetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, tetraglycidylaminodiphenylene, tetraglycidyl-m-xylenediamine, tetra Glycidyl-1,3-bis (aminoethyl) cyclohexane, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacetodiglycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy)- 1-trifluoromethyl-2,2,2-trifluoromethyl) benzene, 4,4-bis (2,3-epoxypropoxy) octafluorobiphenyl , Triglycidyl-p-aminophenol, tetraglycidylmetaxylenediamine, 2- (4- (2,3-epoxypropoxy) phenyl) -2- (4- (1,1-bis (4- (2,3- Epoxypropoxy) phenyl) ethyl) phenyl) propane or 1,3-bis (4- (1- (4- (2,3-epoxypropoxy) phenyl) -1- (4- (1- (4- (2, And 3-epoxypropoxy) phenyl) -1-methylethyl) phenyl) ethyl) phenoxy) -2-propanol.

The crosslinkable compound having an oxetane group is a crosslinkable compound having at least two oxetane groups represented by the following formula [4].

Specifically, crosslinkable compounds represented by the formulas [4a] to [4k] described in the 58th to 59th items of the international publication WO2011 / 132751 can be mentioned.

The crosslinkable compound having a cyclocarbonate group is a crosslinkable compound having at least two cyclocarbonate groups represented by the following formula [5].

Specifically, the crosslinkable compounds represented by the formulas [5-1] to [5-42] described in the paragraphs 76 to 82 of International Publication No. WO2011 / 132751 may be mentioned.

Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxyl group include an amino resin having a hydroxyl group or an alkoxyl group, such as a melamine resin, a urea resin, a guanamine resin, and a glycoluril. -Formaldehyde resin, succinilamide-formaldehyde resin or ethylene urea-formaldehyde resin. Specifically, a melamine derivative, a benzoguanamine derivative, or glycoluril in which a hydrogen atom of an amino group is substituted with a methylol group or an alkoxymethyl group or both can be used. The melamine derivative or benzoguanamine derivative can exist as a dimer or a trimer. These preferably have an average of 3 to 6 methylol groups or alkoxymethyl groups per triazine ring.

Examples of such melamine derivatives or benzoguanamine derivatives include MX-750, which has an average of 3.7 substituted methoxymethyl groups per triazine ring, and an average of 5. methoxymethyl groups per triazine ring. Eight-substituted MW-30 (Sanwa Chemical Co., Ltd.) and Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712 and other methoxymethylated melamines, Cymel 235, 236 Methoxymethylated butoxymethylated melamine such as 238, 212, 253, and 254, butoxymethylated melamine such as Cymel 506 and 508, carboxyl group-containing methoxymethylated isobutoxymethylated melamine such as Cymel 1141, Cymel 1123 and the like Methoxymethylated eth Cymethylated benzoguanamine, methoxymethylated butoxymethylated benzoguanamine such as Cymel 1123-10, butoxymethylated benzoguanamine such as Cymel 1128, carboxyl group-containing methoxymethylated ethoxymethylated benzoguanamine such as Cymel 1125-80 Cyanamide). Examples of glycoluril include butoxymethylated glycoluril such as Cymel 1170, methylolated glycoluril such as Cymel 1172, and methoxymethylolated glycoluril such as Powderlink 1174.

Examples of the benzene or phenolic compound having a hydroxyl group or an alkoxyl group include 1,3,5-tris (methoxymethyl) benzene, 1,2,4-tris (isopropoxymethyl) benzene, 1,4-bis ( sec-butoxymethyl) benzene or 2,6-dihydroxymethyl-p-tert-butylphenol.

More specifically, there are crosslinkable compounds represented by the formulas [6-1] to [6-48], which are listed on pages 62 to 66 of International Publication No. WO2011 / 132751.

Examples of the crosslinkable compound having a polymerizable unsaturated bond include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and tri (meth) acryloyloxyethoxytrimethylol. Crosslinkable compounds having three polymerizable unsaturated groups in the molecule such as propane or glycerin polyglycidyl ether poly (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol Di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide bisphenol A type di (meth) acrylate, propylene oxide bisphenol type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin Di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate or hydroxypivalic acid neo Crosslinkable compounds having two polymerizable unsaturated groups in the molecule, such as pentyl glycol di (meth) acrylate, in addition to 2-hydroxyethyl (meth) acrylate 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro -One polymerizable unsaturated group such as 2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate ester or N-methylol (meth) acrylamide in the molecule A crosslinkable compound is mentioned.

In addition, a compound represented by the following formula [7] can also be used.

(In the formula [7], E ₁ represents a group selected from the group consisting of a cyclohexane ring, a bicyclohexane ring, a benzene ring, a biphenyl ring, a terphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring or a phenanthrene ring; ₂ represents a group selected from the following formula [7a] or [7b], and n represents an integer of 1 to 4.)

The above compound is an example of a crosslinkable compound and is not limited thereto. Moreover, the crosslinkable compound used for the liquid-crystal aligning agent of this invention may be 1 type, and may be combined 2 or more types.

In the liquid crystal aligning agent of the present invention, the content of the crosslinkable compound is preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of all polymer components. In order for the crosslinking reaction to proceed and to achieve the desired effect, the amount is more preferably 0.1 to 100 parts by weight, and most preferably 1 to 50 parts by weight, based on 100 parts by weight of all polymer components.

As a compound that promotes charge transfer in a liquid crystal alignment film and promotes charge release of a liquid crystal cell using the liquid crystal alignment film when a liquid crystal alignment film using the liquid crystal alignment treatment agent using the composition of the present invention is formed. It is preferable to add nitrogen-containing heterocyclic amine compounds represented by the formulas [M1] to [M156], which are described on pages 69 to 73 of International Patent Publication WO2011 / 132751. This amine compound may be added directly to the composition, but it may be added after a solution having a concentration of 0.1% by mass to 10% by mass, preferably 1% by mass to 7% by mass with an appropriate solvent. preferable. The solvent is not particularly limited as long as it is an organic solvent that dissolves the specific polyimide polymer described above.

For the liquid crystal alignment treatment agent of the present invention, a compound that improves the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film when the liquid crystal alignment treatment agent is applied can be used as long as the effects of the present invention are not impaired. Furthermore, a compound that improves the adhesion between the liquid crystal alignment film and the substrate can also be used.

Examples of compounds that improve the film thickness uniformity and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

More specifically, for example, F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFuck F171, F173, R-30 (above, manufactured by Dainippon Ink, Inc.), Florard FC430, FC431 (or above) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, 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 all the polymer components contained in the liquid crystal aligning agent. It is.

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- Riethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl Trimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3- Aminopropyltrimethoxysilane, 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- Tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or N, N, N ′, N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like.

When using a compound to be adhered to these substrates, the amount is preferably 0.1 to 30 parts by weight, more preferably 1 to 30 parts by weight with respect to 100 parts by weight of all polymer components contained in the liquid crystal aligning agent. 20 parts by mass. If it 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 storage stability of the liquid crystal aligning agent may be deteriorated.

The liquid crystal alignment treatment agent of the present invention includes, in addition to the above poor solvent, a crosslinkable compound, a compound that promotes charge removal from the liquid crystal cell, and a compound that improves the film thickness uniformity and surface smoothness of the liquid crystal alignment film, As long as the effects of the present invention are not impaired, a dielectric or conductive material for changing the electrical characteristics such as the dielectric constant and conductivity of the liquid crystal alignment film 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 after being applied and baked on a substrate and then subjected to alignment treatment by rubbing treatment or light irradiation. In the case of vertical alignment, etc., it can be used as a liquid crystal alignment film without alignment treatment. The substrate used at this time is not particularly limited as long as it is a highly transparent substrate. In addition to a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. From the viewpoint of simplification of the process, it is preferable to use a substrate on which an ITO electrode for driving a liquid crystal is formed. In the reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used, and a material that reflects light such as aluminum can be used as an electrode in this case.

The method for applying the liquid crystal aligning agent is not particularly limited, but industrially, a method of screen printing, offset printing, flexographic printing, an inkjet method, or the like is generally used. Examples of other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.

After applying the liquid crystal aligning agent on the substrate, it is preferably 30 to 300 ° C., depending on the solvent used for the liquid crystal aligning agent, by a heating means such as a hot plate, a thermal circulation oven or an IR (infrared) oven. The liquid crystal alignment film can be obtained by evaporating the solvent at a temperature of 30 to 250 ° C. If the thickness of the liquid crystal alignment 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. Is 10 to 100 nm. When the liquid crystal is horizontally aligned or tilted, the fired liquid crystal alignment 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 alignment treatment agent of the present invention by the above-described method and then preparing a liquid crystal cell by a known method. For example, two substrates arranged to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal alignment treatment agent of the present invention provided between the substrate and the liquid crystal layer. A liquid crystal display device comprising a liquid crystal cell having the liquid crystal alignment film. As such a liquid crystal display element of the present invention, a vertical alignment (VA) method, a horizontal alignment (IPS: In-Plane Switching) method, a twisted nematic (TN) method, an OCB alignment (OCB). There are various types such as Optically Compensated Bend, and a system such as PSA (Polymer Sustained Alignment) may be used. Note that the liquid crystal alignment film only needs to be provided on at least one of the two substrates.

As a method for manufacturing a liquid crystal cell, 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 place the other side of the liquid crystal alignment film on the other side. And a method of sealing the substrate by injecting liquid crystal under reduced pressure, or a method of bonding the substrate after dropping the liquid crystal on the surface of the liquid crystal alignment film on which the spacers are dispersed, and the like.

As described above, the liquid crystal display element manufactured using the liquid crystal alignment treatment agent of the present invention has a liquid crystal alignment film in which a decrease in voltage holding ratio is suppressed even when exposed to light irradiation for a long time. Therefore, it has excellent reliability and can be suitably used for a large-screen high-definition liquid crystal television.

Hereinafter, embodiments of the present invention will be described in more detail.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

The abbreviations used in the synthesis examples and examples are as follows.

<Tetracarboxylic dianhydride>
(Specific tetracarboxylic dianhydride)
A1: Tetracarboxylic dianhydride represented by the following formula [A1]

(Specific aliphatic tetracarboxylic dianhydride)
A2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (tetracarboxylic dianhydride represented by the following formula [A2])
A3: Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride (tetracarboxylic dianhydride represented by the following formula [A3])
A4: Tetracarboxylic dianhydride represented by the following formula [A4] A5: Tetracarboxylic dianhydride represented by the following formula [A5]

(Other tetracarboxylic dianhydrides)
A6: pyromellitic dianhydride (tetracarboxylic dianhydride represented by the following formula [A6])

<Diamine component>
B1: 1,3-diamino-4- [4- (trans-4-n-heptylcyclohexyl) phenoxy] benzene (diamine compound represented by the following formula [B1])
B2: 1,3-diamino-5- [4- (trans-4-n-heptylcyclohexyl) phenoxymethyl] benzene (diamine compound represented by the following formula [B2])
B3: 1,3-diamino-4- {4- [trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene (diamine compound represented by the following formula [B3])
B4: 1,3-diamino-5- {4- [4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxymethyl} benzene (diamine compound represented by the following formula [B4])
B5: Specific side chain diamine compound represented by the following formula [B5] B6: 1,3-diamino-4-octadecyloxybenzene (diamine compound represented by the following formula [B6])
B7: m-phenylenediamine (diamine compound represented by the following formula [B7])
B8: p-phenylenediamine (diamine compound represented by the following formula [B8])
B9: 3,5-diaminobenzoic acid (diamine compound represented by the following formula [B9])
B10: Diamine compound represented by the following formula [B10]

<Organic solvent>
(Polar solvent)
NMP: N-methyl-2-pyrrolidone NEP: N-ethyl-2-pyrrolidone G-BL: γ-butyrolactone

(Other organic solvents)
BCS: 2-butoxyethanol PB: Propylene glycol monobutyl ether

<Measurement of molecular weight of polyimide precursor and polyimide>
The molecular weights of the polyimide precursor and the polyimide in the synthesis example are determined using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko KK) and a column (KD-803, KD-805) (manufactured by Shodex). The measurement was performed as follows.
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additive, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L (liter), phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol) / L, 10 ml / L of tetrahydrofuran (THF))
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, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; (About 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory)

<Measurement of imidation ratio of polyimide>
The imidation ratio of polyimide in the synthesis example was measured as follows. 20 mg of polyimide powder was put into an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05 mass% TMS (tetramethylsilane)). (Mixed product) (0.53 ml) was added and 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 based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid that appear in the vicinity of 9.5 ppm 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.

<Synthesis Example 1>
A1 (3.82 g, 18.0 mmol), B1 (4.11 g, 10.8 mmol), B7 (2.75 g, 25.2 mmol) were mixed in NMP (22.8 g) and reacted at 40 ° C. for 5 hours. After that, A2 (3.53 g, 18.0 mmol) and NMP (18.7 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (A) having a solid content concentration of 20.0% by mass. Obtained. The number average molecular weight of this polyamic acid was 11,500, and the weight average molecular weight was 38,600.

<Synthesis Example 2>
A1 (3.81 g, 18.0 mmol), B2 (4.25 g, 10.8 mmol), B8 (2.72 g, 25.1 mmol) were mixed in NMP (23.1 g) and reacted at 40 ° C. for 5 hours. After that, A2 (3.52 g, 18.0 mmol) and NMP (18.9 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (2.01 g) and pyridine (1.02 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (B). The imidation ratio of this polyimide was 50%, the number average molecular weight was 12,500, and the weight average molecular weight was 38,200.

<Synthesis Example 3>
A1 (2.83 g, 13.3 mmol), B6 (3.76 g, 10.0 mmol) and B10 (2.72 g, 23.3 mmol) were mixed in NMP (16.9 g) and reacted at 40 ° C. for 5 hours. After that, A2 (3.92 g, 20.0 mmol) and NMP (13.8 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.1 g) and diluting to 6% by mass, acetic anhydride (2.28 g) and pyridine (1.18 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (C). The imidation ratio of this polyimide was 70%, the number average molecular weight was 11,500, and the weight average molecular weight was 31,400.

<Synthesis Example 4>
A1 (4.50 g, 21.2 mmol) and B7 (4.59 g, 42.4 mmol) were mixed in NMP (21.8 g), reacted at 40 ° C. for 5 hours, and then A3 (5.31 g, 21). 0.2 mmol) and NMP (17.8 g) were added and reacted at 50 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (2.73 g) and pyridine (1.60 g) were added as imidization catalysts, The reaction was allowed for 5 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (D). The imidation ratio of this polyimide was 53%, the number average molecular weight was 13,100, and the weight average molecular weight was 35,000.

<Synthesis Example 5>
A1 (1.10 g, 5.19 mmol), B1 (3.95 g, 10.4 mmol), B9 (2.37 g, 15.6 mmol) were mixed in NMP (22.9 g) and reacted at 40 ° C. for 5 hours. After that, A2 (4.07 g, 20.8 mmol) and NMP (18.7 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (2.12 g) and pyridine (1.15 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (E). The imidation ratio of this polyimide was 52%, the number average molecular weight was 12,600, and the weight average molecular weight was 36,200.

<Synthesis Example 6>
A1 (7.80 g, 36.7 mmol) and B8 (6.11 g, 56.5 mmol) were mixed in NMP (22.0 g), reacted at 40 ° C. for 5 hours, and then A2 (3.88 g, 19). .8 mmol) and NMP (18.0 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (F) having a solid content concentration of 20.0 mass%. The number average molecular weight of this polyamic acid was 11,200, and the weight average molecular weight was 38,500.

<Synthesis Example 7>
A1 (1.41 g, 6.65 mmol), B5 (2.62 g, 5.32 mmol) and B9 (3.24 g, 21.3 mmol) were mixed in NMP (23.9 g) and reacted at 40 ° C. for 5 hours. After that, A3 (4.99 g, 19.9 mmol) and NMP (19.5 g) were added and reacted at 50 ° C. for 6 hours to obtain a polyamic acid solution (G) having a solid content concentration of 20.0 mass%. Obtained. The number average molecular weight of this polyamic acid was 13,500, and the weight average molecular weight was 35,600.

<Synthesis Example 8>
A1 (3.06 g, 14.4 mmol), B3 (3.74 g, 8.65 mmol) and B10 (2.47 g, 20.2 mmol) were mixed in NMP (1.53 g) and reacted at 40 ° C. for 5 hours. After that, A4 (3.23 g, 14.4 mmol) and NMP (12.6 g) were added and reacted at 50 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (1.89 g) and pyridine (0.90 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (H). The imidation ratio of this polyimide was 70%, the number average molecular weight was 11,800, and the weight average molecular weight was 30,400.

<Synthesis Example 9>
A1 (2.25 g, 10.6 mmol), B4 (2.71 g, 6.06 mmol), B7 (1.64 g, 15.2 mmol), B9 (1.38 g, 9.09 mmol) and NMP (2.23 g) After mixing at 40 ° C. for 5 hours, A4 (4.42 g, 19.7 mmol) and NMP (18.3 g) were added, and the mixture was reacted at 50 ° C. for 6 hours. A 0% by weight polyamic acid solution was obtained.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (2.20 g) and pyridine (1.12 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (I). The imidation ratio of this polyimide was 51%, the number average molecular weight was 11,000, and the weight average molecular weight was 30,100.

<Synthesis Example 10>
A1 (2.02 g, 9.52 mmol) and B8 (3.43 g, 31.7 mmol) were mixed in NMP (22.2 g), reacted at 40 ° C. for 5 hours, and then A5 (6.67 g, 22). 0.2 mmol) and NMP (18.2 g) were added and reacted at 25 ° C. for 12 hours to obtain a polyamic acid solution (J) having a solid content concentration of 20.0 mass%. The number average molecular weight of this polyamic acid was 11,800, and the weight average molecular weight was 36,300.

<Synthesis Example 11>
A1 (11.2 g, 52.9 mmol), B1 (6.04 g, 15.9 mmol) and B7 (4.01 g, 37.1 mmol) were mixed in NMP (40.2 g) and reacted at 40 ° C. for 24 hours. Thus, a polyamic acid solution (K) having a solid content concentration of 20.0% by mass was obtained. The number average molecular weight of this polyamic acid was 7,100, and the weight average molecular weight was 29,800.

<Synthesis Example 12>
A2 (5.10 g, 26.0 mmol), B6 (2.94 g, 7.80 mmol), B10 (2.22 g, 18.2 mmol) were mixed in NMP (32.2 g) and reacted at 40 ° C. for 8 hours. Thus, a polyamic acid solution having a solid content concentration of 20.0% by mass was obtained.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (2.00 g) and pyridine (1.01 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (L). The imidation ratio of this polyimide was 70%, the number average molecular weight was 13,800, and the weight average molecular weight was 35,600.

<Synthesis Example 13>
A3 (3.80 g, 15.2 mmol) and B7 (3.29 g, 30.4 mmol) were mixed in NMP (22.2 g), reacted at 50 ° C. for 3 hours, and then A2 (2.98 g, 15). 0.2 mmol) and NMP (18.1 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (3.10 g) and pyridine (1.52 g) were added as an imidization catalyst, The reaction was allowed for 5 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (M). The imidation ratio of this polyimide was 50%, the number average molecular weight was 14,700, and the weight average molecular weight was 37,100.

<Synthesis Example 14>
A1 (1.03 g, 4.85 mmol), B1 (3.70 g, 9.71 mmol) and B9 (2.22 g, 14.6 mmol) were mixed in NMP (22.3 g) and reacted at 40 ° C. for 5 hours. After that, A6 (4.24 g, 19.4 mmol) and NMP (18.3 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a solid content concentration of 20.0 mass%.

After adding NMP to the obtained polyamic acid solution (15.0 g) and diluting to 6% by mass, acetic anhydride (1.86 g) and pyridine (0.98 g) were added as imidization catalysts, Reacted for hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 60 degreeC, and obtained the polyimide powder (N). The imidation ratio of this polyimide was 52%, the number average molecular weight was 13,800, and the weight average molecular weight was 34,700.

<Synthesis Example 15>
A6 (4.52 g, 20.7 mmol) and B8 (3.45 g, 31.9 mmol) were mixed in NMP (22.4 g), reacted at 40 ° C. for 5 hours, and then A2 (2.19 g, 11 0.2 mmol) and NMP (18.3 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (O) having a solid content concentration of 20.0 mass%. The number average molecular weight of this polyamic acid was 16,100, and the weight average molecular weight was 42,000.

Table 1 shows the polyamic acids and polyimides obtained in Synthesis Examples 1-15.

<Example 1>
The polyamic acid solution (A) (9.03 g), NMP (8.90 g) and BCS (12.0 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 1 were mixed at 25 ° C. for 8 hours. As a result, a liquid crystal aligning agent (1) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (1), “Preparation of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 2>
The polyimide powder (B) obtained in Synthesis Example 2 (1.80 g), NMP (9.02 g), NEP (7.51 g) and BCS (13.5 g) were mixed at 25 ° C. for 8 hours, A liquid crystal aligning agent (2) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (2), “preparation of liquid crystal cell and evaluation of electric characteristics” were performed under the above-described conditions.

<Example 3>
The polyimide powder (B) obtained in Synthesis Example 2 (1.50 g), NMP (12.4 g), NEP (10.3 g) and BCS (18.6 g) were mixed at 25 ° C. for 8 hours, A liquid crystal aligning agent (3) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (3), “evaluation of ink jet coatability of liquid crystal aligning agent” was performed under the above-described conditions.

<Example 4>
The polyimide powder (C) obtained in Synthesis Example 3 (1.80 g), NMP (9.01 g), G-BL (9.02 g) and BCS (12.0 g) were mixed at 25 ° C. for 8 hours. Thus, a liquid crystal aligning agent (4) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (4), “Preparation of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 5>
Polyimide powder (D) obtained in Synthesis Example 4 (1.80 g), NMP (7.53 g), NEP (12.1 g), G-BL (1.53 g) and PB (9.11 g) The liquid crystal aligning agent (5) was obtained by mixing at 0 ° C. for 8 hours. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (5), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 6>
The polyimide powder (E) (1.79 g), NMP (9.00 g), NEP (14.5 g), BCS (3.02 g) and PB (3.00 g) obtained in Synthesis Example 5 were heated to 25 ° C. For 8 hours to obtain a liquid crystal aligning agent (6). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (6), “Preparation of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 7>
The polyimide powder (E) obtained in Synthesis Example 5 (1.50 g), NMP (8.27 g), NEP (16.5 g) and PB (16.5 g) were mixed at 25 ° C. for 8 hours, A liquid crystal aligning agent (7) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (7), “evaluation of ink jet coatability of liquid crystal aligning agent” was performed under the above-described conditions.

<Example 8>
Polyamic acid solution (F) (9.00 g), NMP (3.00 g), G-BL (9.06 g) and BCS (9.01 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 6 Were mixed at 25 ° C. for 8 hours to obtain a liquid crystal aligning agent (8). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (8), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 9>
Polyamic acid solution (G) (9.01 g), NEP (9.02 g), G-BL (9.02 g), BCS (6.01 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 7 And PB (6.00 g) were mixed at 25 ° C. for 8 hours to obtain a liquid crystal aligning agent (9). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (9), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 10>
The polyimide powder (H) (1.80 g), NMP (6.00 g), NEP (6.05 g), BCS (6.04 g) and PB (3.01 g) obtained in Synthesis Example 8 were heated to 25 ° C. For 8 hours to obtain a liquid crystal aligning agent (10). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (10), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 11>
The polyimide powder (I) obtained in Synthesis Example 9 (1.80 g), NMP (12.0 g), NEP (9.00 g) and BCS (9.05 g) were mixed at 25 ° C. for 8 hours, A liquid crystal aligning agent (11) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (11), “Preparation of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Example 12>
The polyamic acid solution (J) (9.04 g), NMP (16.5 g), NEP (9.02 g) and PB (4.50 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 10 were The liquid crystal aligning agent (12) was obtained by mixing at 25 ° C. for 8 hours. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (12), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Comparative Example 1>
The polyamic acid solution (K) (9.03 g), NMP (9.31 g) and BCS (12.2 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 11 were mixed at 25 ° C. for 8 hours. As a result, a liquid crystal aligning agent (13) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (13), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Comparative example 2>
The polyimide powder (L) obtained in Synthesis Example 12 (1.80 g), NMP (9.00 g), G-BL (9.02 g) and BCS (12.0 g) were mixed at 25 ° C. for 8 hours. Thus, a liquid crystal aligning agent (14) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
"Production of liquid crystal cell and evaluation of electrical characteristics" were performed using the obtained liquid crystal aligning agent (14) under the conditions described above.

<Comparative Example 3>
Polyimide powder (M) obtained in Synthesis Example 13 (1.80 g), NMP (7.50 g), NEP (12.0 g), G-BL (1.50 g) and PB (9.00 g) A liquid crystal aligning agent (15) was obtained by mixing at 0 ° C. for 8 hours. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (15), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

<Comparative example 4>
The polyimide powder (N) (1.80 g), NMP (9.00 g), NEP (15.0 g), BCS (3.06 g) and PB (3.03 g) obtained in Synthesis Example 14 were heated to 25 ° C. For 8 hours to obtain a liquid crystal aligning agent (16). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (16), “Preparation of liquid crystal cell and evaluation of electrical characteristics” were performed under the conditions described above.

<Comparative Example 5>
Polyamic acid solution (O) (9.05 g), NMP (3.00 g), G-BL (9.02 g) and BCS (9.00 g) having a solid content concentration of 20.0% by mass obtained in Synthesis Example 15 Were mixed at 25 ° C. for 8 hours to obtain a liquid crystal aligning agent (17). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (17), “Production of liquid crystal cell and evaluation of electrical characteristics” were performed under the above-described conditions.

Using the liquid crystal aligning agent obtained in each of the examples and comparative examples of the present invention, “preparation of liquid crystal cell”, “evaluation of electrical characteristics (voltage holding ratio)” and “ink-jet coating property of liquid crystal aligning agent” Evaluation "was performed. The conditions are as follows.

Tables 1 and 2 show the raw materials (tetracarboxylic dianhydride and diamine component) of the specific polymer contained in the liquid crystal aligning agents obtained in Examples 1 to 12 and Comparative Examples 1 to 5.

<Production of liquid crystal cell and evaluation of electrical characteristics>
The liquid crystal alignment treatment agents obtained in Examples 1, 2, 4 to 6, 8 to 12 and Comparative Examples 1 to 5 were filtered under pressure through a membrane filter having a pore diameter of 1 μm to produce a liquid crystal cell. This solution was spin-coated on the ITO surface of a 30 × 40 mm ITO electrode substrate (40 mm long × 30 mm wide, 0.7 mm thick) washed with pure water and IPA, and heated at 80 ° C. for 5 minutes on a hot plate. Then, heat treatment was performed at 230 ° C. for 30 minutes in a heat circulation type clean oven to obtain an ITO substrate with a polyimide liquid crystal alignment film having a film thickness of 100 nm. The surface of the ITO substrate was rubbed using a rayon cloth with a rubbing apparatus having a roll diameter of 120 mm under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.1 mm.

Two obtained ITO substrates with a liquid crystal alignment film were prepared, combined with a 6 μm spacer sandwiched with the liquid crystal alignment film surface inside, and a sealant (XN-1500T) (Mitsui Chemicals) was printed. Next, after bonding the other substrate and the liquid crystal alignment film face each other, the sealing agent was cured by heat treatment at 150 ° C. for 90 minutes in a heat-circulating clean oven to produce an empty cell. . Liquid crystal was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell.

In addition, the liquid crystal aligning agent (1) obtained in Example 1, the liquid crystal aligning agent (2) obtained in Example 2, the liquid crystal aligning agent (4) obtained in Example 4, and Example 6 Liquid crystal aligning agent (6) obtained in Example 9, Liquid crystal aligning agent (9) to liquid crystal aligning agent (11) obtained in Examples 9 to 11, Liquid crystal aligning agent obtained in Comparative Example 1 (13) In a liquid crystal cell using the liquid crystal aligning agent (14) obtained in Comparative Example 2 and the liquid crystal aligning agent (16) obtained in Comparative Example 4, nematic liquid crystal (MLC-6608) is used as the liquid crystal. (Merck Japan Co., Ltd.) was used.

In addition, the liquid crystal aligning agent (5) obtained in Example 5, the liquid crystal aligning agent (8) obtained in Example 8, the liquid crystal aligning agent (12) obtained in Example 12, and Comparative Example 3 In the liquid crystal cell using the liquid crystal aligning agent (15) obtained in 1 and the liquid crystal aligning agent (17) obtained in Comparative Example 5, the liquid crystal is nematic liquid crystal (MLC-2041) (manufactured by Merck Japan). Was used.

The liquid crystal alignment was evaluated using the liquid crystal cell obtained above. The liquid crystal alignment was confirmed by observing the liquid crystal cell with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) to check for the presence of alignment defects. As a result, no alignment defects were observed in the liquid crystal cells obtained in any of the examples and comparative examples, and uniform alignment was exhibited.

Furthermore, a voltage of 1 V was applied to the liquid crystal cell produced above at 60 ° C. at a temperature of 80 ° C., the voltage after 16.67 ms and 50 ms was measured, and the voltage holding ratio (VHR) ). The measurement was performed using a VHR-1 voltage holding ratio measuring device (manufactured by Toyo Technica) with settings of Voltage: ± 1 V, Pulse Width: 60 μs, Frame Period: 16.67 ms or 50 ms. Furthermore, after irradiating the liquid crystal cell in which the measurement of the voltage holding ratio was completed with ultraviolet rays of 50 J / cm ^{2 in} terms of 365 nm, the voltage holding ratio was measured under the same conditions as described above. The ultraviolet irradiation was performed using a desktop UV curing device (HCT3B28HEX-1) (manufactured by SEN LIGHT CORPORATION).

Table 3 shows the measurement results of the voltage holding ratio. Since the voltage holding ratio depends on the type of the diamine component, it is necessary to compare those using the same diamine component.

The liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of each example does not decrease the voltage holding ratio even when exposed to ultraviolet irradiation, compared to the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of each comparative example. It has become smaller.

Specifically, in Example 1, two types of tetracarboxylic dianhydrides, a specific tetracarboxylic dianhydride and a specific aliphatic tetracarboxylic dianhydride, are used. In Comparative Example 1, one of the specific tetracarboxylic dianhydrides is used. Only tetracarboxylic dianhydride is used. The diamine components (B1 and B7) are the same. As a result, the voltage holding ratio of Comparative Example 1 was greatly reduced by the irradiation of ultraviolet rays.

Similarly, in Example 4, two types of tetracarboxylic dianhydrides are used, but in Comparative Example 2, only the other specific aliphatic tetracarboxylic dianhydride is used. The diamine components (B6 and B10) are the same. As a result, the voltage holding ratio of Comparative Example 2 was further greatly reduced by irradiation with ultraviolet rays.

In the comparison between Example 5 and Comparative Example 3, similar results were obtained.

Further, in comparison between Example 6 and Comparative Example 4, and Example 8 and Comparative Example 5, one of two types of tetracarboxylic dianhydrides and other tetracarboxylic dianhydrides were compared with Comparative Examples 4, 5 However, the voltage holding ratios of Comparative Examples 4 and 5 were greatly reduced by irradiation with ultraviolet rays.

As a result, two types of tetracarboxylic dianhydrides, a specific tetracarboxylic dianhydride and a specific aliphatic tetracarboxylic dianhydride, are used as raw materials for the specific polymer contained in the liquid crystal aligning agent of the present invention. Thus, it was found that a decrease in voltage holding ratio was suppressed and a liquid crystal alignment film having excellent light resistance could be produced. A liquid crystal display element having such a liquid crystal alignment film has light resistance and excellent reliability even when exposed to light irradiation for a long time without decreasing the voltage holding ratio.

<Evaluation of inkjet coating property of liquid crystal aligning agent>
The liquid crystal alignment treatment agent (3) obtained in Example 3 of the present invention and the liquid crystal alignment treatment agent (7) obtained in Example 7 were pressure filtered through a membrane filter having a pore diameter of 1 μm, and evaluation of ink jet coatability was performed. Went. As the ink jet coater, HIS-200 (manufactured by Hitachi Plant Technology) was used. Application is on an ITO (indium tin oxide) vapor-deposited substrate cleaned with pure water and IPA (isopropyl alcohol), the application area is 70 × 70 mm, the nozzle pitch is 0.423 mm, and the scan pitch is 0.5 mm. The speed was 40 mm / second, the time from application to temporary drying was 60 seconds, and temporary drying was performed on a hot plate at 70 ° C. for 5 minutes.

In any of the Examples, no repelling or pinholes were observed on the obtained liquid crystal alignment film, and a uniformly coated liquid crystal alignment film was obtained.

Here, the liquid crystal aligning agent (3) obtained in Example 3 and the liquid crystal aligning agent (7) obtained in Example 7 were a specific tetracarboxylic dianhydride and a specific aliphatic tetracarboxylic dianhydride. It contains a specific polymer obtained by reacting two types of tetracarboxylic dianhydrides with a diamine component. Specifically, the liquid crystal aligning agent (3) of Example 3 has the same configuration as the liquid crystal aligning agent (2) of Example 2, and the liquid crystal aligning agent (7) of Example 7 is The structure is the same as that of the liquid crystal aligning agent (6) of Example 6.

For this reason, the liquid crystal aligning film obtained by the inkjet method using the liquid crystal aligning agent (3) of Example 3 and the liquid crystal aligning agent (7) of Example 7 is the measurement result of the above-mentioned voltage holding ratio ( In view of Examples 2 and 6), it is presumed that the decrease in the voltage holding ratio is suppressed and that the light resistance is excellent. Therefore, a liquid crystal display element having a liquid crystal alignment film obtained by an inkjet method is similarly excellent in reliability without being lowered in voltage holding ratio even when exposed to light irradiation for a long time. .

Claims

Polyimide obtained by reacting a tetracarboxylic acid component containing a tetracarboxylic dianhydride represented by the following formula [1] and an aliphatic tetracarboxylic dianhydride represented by the following formula [2] with a diamine component A liquid crystal aligning agent comprising a precursor and at least one polymer selected from polyimides obtained by imidizing the polyimide precursor.

(In the formula [2], Z 1 is at least one tetravalent group selected from the following formulas [2a] to [2j].)

(In the formula [2a], Z 2 to Z 5 represent a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different. In the formula [2g], Z 6 and Z 7 are A hydrogen atom or a methyl group, which may be the same or different.
2. The liquid crystal aligning agent according to claim 1, which contains N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone as a solvent in the liquid crystal aligning agent.
3. The solvent according to claim 1, comprising a solvent selected from the solvents represented by the following formulas [D-1] to [D-3] as a solvent in the liquid crystal aligning agent. Liquid crystal aligning agent.

(In the formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-2], D 2 represents an alkyl group having 1 to 3 carbon atoms, and the formula [D-3 D 3 represents an alkyl group having 1 to 4 carbon atoms.
A liquid crystal alignment film obtained by using the liquid crystal alignment treatment agent according to claim 1.
A liquid crystal alignment film obtained by an ink jet method using the liquid crystal alignment treatment agent according to claim 1.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 4.