JPWO2008010528A1 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element using the same - Google Patents

Abstract

To provide a liquid crystal alignment film that suppresses the precipitation of resin components due to moisture absorption, has stable printability, and has characteristics such as rubbing resistance and ease of escape of accumulated charges. Component (A): a solvent obtained from at least one amine compound selected from the group consisting of tetracarboxylic dianhydride, diamine compound, the following amine compound (a), amine compound (b) and amine compound (c) A coating liquid comprising a soluble imidized polymer and (B) component: polyamic acid. Amine compound (a): an amine having one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] in the molecule Compound. Note that in the formulas [K3] and [K4], the bonding direction of —CH 2 —NH— is opposite. Amine compound (b): An amine compound having at least two primary amino groups selected from the above formulas [K1] and [K2] in the molecule. Amine compound (c): an amine having at least one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] in the molecule Compound.

Description

  The present invention relates to a coating liquid suitable as a liquid crystal aligning agent, and further relates to a liquid crystal alignment film and a liquid crystal display element obtained using the coating liquid.

  Currently, a liquid crystal alignment film used for a liquid crystal display element or the like generally uses polyimide, and is usually manufactured by applying a solution called a liquid crystal aligning agent and baking it. In this case, the liquid crystal aligning agent is generally a solution containing a polyimide precursor such as polyamic acid or a solvent-soluble polyimide, but contains both a polyamic acid and a solvent-soluble polyimide (see Patent Document 1). In addition, a polyamic acid and one containing two or more types of imidized polymers having different imidization ratios obtained by dehydrating and ring-closing polyamic acid have been proposed (see Patent Document 2). Thus, the liquid crystal alignment film obtained from the liquid crystal aligning agent containing several kinds of resin components has some required characteristics such as liquid crystal alignment, liquid crystal pretilt angle, and various electric characteristics of the liquid crystal cell. It is known that it can be realized simultaneously.

  In order to produce liquid crystal alignment films industrially, the method of applying a liquid crystal alignment agent by flexographic printing using a printing press is currently the mainstream, but if printing is continued for a long period of time, the uniformity of the coating will decrease. In some cases, printing failure occurred. One reason for this is that the liquid crystal aligning agent staying on the printing press is concentrated by the volatilization of the solvent and further absorbs moisture, causing the resin components in the solution to aggregate and precipitate. Therefore, this phenomenon becomes prominent when a main solvent is a highly hygroscopic solvent such as an amide solvent. Further, although the detailed cause has not been elucidated, in the case of a liquid crystal aligning agent containing both polyamic acid and soluble polyimide, the above-mentioned printing failure is likely to occur. For this phenomenon, it has been proposed to use a compound having a biphenyldiamine skeleton as a diamine component for obtaining a soluble polyimide (see Patent Document 3).

JP-A-8-220541 JP-A-9-297312 International Publication No. 2004/090016 pamphlet

The problem to be solved by the present invention is to improve the stability during moisture absorption with respect to a coating solution containing both a polyamic acid and an imidized polymer soluble in a solvent.
An object of the present invention is to provide a coating liquid suitable as a liquid crystal aligning agent, to provide a high-quality liquid crystal alignment film, and to provide a high-quality liquid crystal display element.

  As a result of intensive studies to solve the above problems, the present inventors have made a specific amine compound react with a solvent-soluble polyimide or use a specific amine compound as a raw material when producing a solvent-soluble polyimide. As a result, it was found that the moisture absorption stability of the mixed solution with the polyamic acid was improved, and the present invention was completed. That is, the present invention has the following features.

(1) Component (A): obtained from at least one amine compound selected from the group consisting of tetracarboxylic dianhydride, diamine compound, the following amine compound (a), amine compound (b) and amine compound (c) The coating liquid characterized by containing the imidized polymer soluble in the solvent obtained, and (B) component: polyamic acid.
Amine compound (a): an amine having in its molecule one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] Compound. Note that in the formulas [K3] and [K4], the bonding directions of —CH ₂ —NH— are opposite to each other.
Amine compound (b): An amine compound having at least two primary amino groups selected from the above formulas [K1] and [K2] in the molecule.
Amine compound (c): an amine having at least one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] in the molecule Compound.

（２）（Ａ）成分が、テトラカルボン酸二無水物とジアミン化合物から得られる溶媒可溶性ポリイミドの側鎖及び分子末端のうちの少なくとも一方と、前記アミン化合物（ａ）及びアミン化合物（ｂ）から選ばれる少なくとも一種のアミン化合物とが結合して得られる溶媒に可溶なイミド化重合体である上記（１）に記載の塗布液。
（３）（Ａ）成分が、テトラカルボン酸二無水物とジアミン化合物から得られる溶媒可溶性ポリイミドに、前記アミン化合物（ａ）及びアミン化合物（ｂ）から選ばれる少なくとも一種のアミン化合物を反応させて得られる生成物である上記（１）に記載の塗布液。
（４）（Ａ）成分が、テトラカルボン酸二無水物とアミン化合物（ｃ）を含むジアミン化合物とを反応させたポリイミド前駆体をイミド化して得られる溶媒に可溶なイミド化重合体である上記（１）に記載の塗布液。
（５）（Ａ）成分が、前記アミン化合物（ａ）として、下記式（ｉ）及び（ｉｉ）で表されるアミン化合物から選ばれる少なくとも一種のアミン化合物を用いて得られる溶媒に可溶なイミド化重合体である上記（１）に記載の塗布液。

(2) The component (A) is composed of at least one of a side chain and a molecular end of a solvent-soluble polyimide obtained from tetracarboxylic dianhydride and a diamine compound, and the amine compound (a) and the amine compound (b). The coating liquid according to (1) above, which is an imidized polymer soluble in a solvent obtained by bonding with at least one selected amine compound.
(3) (A) component makes the solvent soluble polyimide obtained from a tetracarboxylic dianhydride and a diamine compound react with at least one amine compound selected from the amine compound (a) and the amine compound (b). The coating solution according to (1), which is a product obtained.
(4) The component (A) is an imidized polymer soluble in a solvent obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a diamine compound containing an amine compound (c). The coating solution according to (1) above.
(5) The component (A) is soluble in a solvent obtained using at least one amine compound selected from the amine compounds represented by the following formulas (i) and (ii) as the amine compound (a). The coating solution according to (1), which is an imidized polymer.

〔ただし、式中のＲ^１は、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、もしくは−ＣＨ（ＣＨ_２ＣＨ_３）−のアルキレン、又は脂肪族環を表し、Ｘ^１は、単結合又は炭素原子数１〜２０の脂肪族炭化水素を表し、かつ脂肪族炭化水素中に−ＮＨ−を含んでいてもよい。また、Ｘ^２は炭素原子数１〜２０の有機基を表し、炭素原子数１〜２０のアルキル基、環状脂肪族基、芳香族基、複素環基、カルボキシル基及びこれらの組み合わせからなる有機基で、かつ、不飽和結合、エーテル結合（−Ｏ−）、ケトン結合（−ＣＯ−）、エステル結合（−ＣＯＯ−）、アミノ結合（−ＮＨ−）、アミン結合（−Ｎ−）、シリル結合（−Ｓｉ−）、シロキサン結合（−ＳｉＯ−）などを含んでいてもよい。さらに、Ｘ^２のアルキル基が−Ｒ^１−、−Ｘ^１−、−ＣＨ_２−、及び−ＮＨ−のいずれかと複素環状構造を形成していてもよい。〕

[Wherein R ¹ represents —CH ₂ —, —CH (CH ₃ ) —, or —CH (CH ₂ CH ₃ ) —, an alkylene, or an aliphatic ring, and X ¹ represents a single bond or It represents an aliphatic hydrocarbon having 1 to 20 carbon atoms, and the aliphatic hydrocarbon may contain —NH—. X ² represents an organic group having 1 to 20 carbon atoms, and an organic group comprising an alkyl group having 1 to 20 carbon atoms, a cyclic aliphatic group, an aromatic group, a heterocyclic group, a carboxyl group, and a combination thereof. And unsaturated bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), amino bond (—NH—), amine bond (—N—), silyl bond (—Si—), siloxane bond (—SiO—) and the like may be included. Further, the alkyl group of X ² may form a heterocyclic structure with any of —R ¹ —, —X ¹ —, —CH ₂ —, and —NH—. ]

(6) The component (A) is soluble in a solvent obtained by using at least one amine compound selected from amine compounds represented by the following formulas (iii) to (v) as the amine compound (b). The coating solution according to (1), which is an imidized polymer.

〔ただし、式中のＲ^１は、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、もしくは−ＣＨ（ＣＨ_２ＣＨ_３）−のアルキレン、又は脂肪族環を表し、Ｈ_２Ｎ−Ｒ^１−と−Ｒ^１−ＮＨ_２のＲ^１は同一でも異なっていてもよい。Ｘ^３は、単結合、又は炭素原子数１〜２０の有機基を表し、炭素原子数１〜２０のアルキレン、脂肪族環、芳香族環、複素環及びこれらの組み合わせからなる有機基で、かつ、不飽和結合、エーテル結合（−Ｏ−）、ケトン結合（−ＣＯ−）、エステル結合（−ＣＯＯ−）、チオエーテル結合（−Ｓ−）、シリル結合（−Ｓｉ−）、シロキサン結合（−ＳｉＯ−）などを含んでいてもよい。Ｘ^４、Ｘ^５、Ｘ^６、Ｘ^７及びＸ^８は、それぞれ独立に炭素原子数１〜２０の脂肪族炭化水素を表し、それぞれ同一でも異なっていてもよい。〕
（７）（Ａ）成分が、前記アミン化合物（ｃ）として、下記式（i）、（ii）、(iv)及び（v）で表されるアミン化合物から選ばれる少なくとも一種のアミン化合物を用いて得られる溶媒に可溶なイミド化重合体である上記（１）に記載の塗布液。

[In the formula, R ¹ represents —CH ₂ —, —CH (CH ₃ ) —, or —CH (CH ₂ CH ₃ ) —, an alkylene, or an aliphatic ring, and H ₂ N—R ¹ — as ^{R 1 -R} 1 -NH ₂ may be the same or different. X ³ represents a single bond or an organic group having 1 to 20 carbon atoms, an organic group consisting of alkylene having 1 to 20 carbon atoms, an aliphatic ring, an aromatic ring, a heterocyclic ring, and a combination thereof, and , Unsaturated bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), thioether bond (—S—), silyl bond (—Si—), siloxane bond (—SiO 2) -) Etc. may be included. X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ each independently represent an aliphatic hydrocarbon having 1 to 20 carbon atoms, and may be the same or different. ]
(7) The component (A) uses at least one amine compound selected from amine compounds represented by the following formulas (i), (ii), (iv) and (v) as the amine compound (c). The coating liquid according to (1) above, which is an imidized polymer soluble in a solvent obtained in this manner.

(8) The ratio of the imidized polymer of the component (A) and the polyamic acid of the component (B) is 20 to 20 in the total mass of the component (A) and the component (B). The coating solution according to any one of (1), (2), and (4) to (7), which is 99% by mass.
(9) The component (A) is at least one amine selected from the amine compound (a) and the amine compound (b) with respect to 100 parts by mass of the solvent-soluble polyimide obtained from the tetracarboxylic dianhydride and the diamine compound. The coating liquid according to (3), which is a product obtained by reacting 1 to 15 parts by mass of a compound.
(10) The component (A) is a imide soluble in a solvent obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a diamine containing the amine compound (c) represented above. The coating liquid as described in said (4) or (7) whose quantity of an amine compound (c) is 1 mol%-15 mol% in the total amount which match | combined the diamine and the amine compound (c) in the chemical polymer.
(11) A liquid crystal aligning agent comprising the coating liquid according to any one of (1) to (10) above.
(12) The liquid crystal aligning agent according to the above (11), wherein the amide solvent contains 50% by mass or more in the coating solution.
(13) A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to (11) or (12).
(14) A liquid crystal display device using the liquid crystal alignment film according to (13).

  According to the coating liquid of the present invention, precipitation of the resin component due to moisture absorption is suppressed, stable printability can be obtained, and it can be suitably used as a liquid crystal aligning agent. In addition, since the liquid crystal alignment film obtained using the coating liquid of the present invention has improved rubbing resistance and improved ease of stored charge release, a higher-quality liquid crystal display element can be obtained.

It is a graph which shows the comparison of the ease of discharge | release of the accumulation charge of the liquid crystal cell using the liquid crystal aligning agent which consists of the coating liquid of Example 4 or the comparative example 1. FIG.

In the coating liquid containing both the imidized polymer soluble in the solvent and the polyamic acid, the imidized polymer component soluble in the solvent is a liquid crystal cell particularly when the liquid crystal alignment film is formed at a low firing temperature. The polyamic acid component contributes to the printability, the adhesion to the substrate, the reduction of charge accumulation when the liquid crystal alignment film is used, the ease of charge removal, and the like. In addition, it is said that, after the coating film is formed, the concentration of soluble polyimide and polyamic acid in the film thickness direction has a gradient, so that it is difficult to obtain with a single resin component.
However, as described above, the liquid crystal aligning agent staying on the printing press is concentrated by volatilization of the solvent and further absorbs moisture, and the resin component in the solution is agglomerated while having such excellent characteristics. And the occurrence of precipitation are considered to be one of the causes of printing defects.
Therefore, the present inventors, by the action of a specific amine compound, moderately suppress this phase separation, without losing the advantage of containing both solvent-soluble polyimide and polyamic acid, stability during moisture absorption Has been found to improve, and the present invention has been completed.
That is, the present invention provides a imide soluble in a solvent obtained from a tetracarboxylic dianhydride, a diamine compound, and at least one amine compound selected from the following amine compound (a) and amine compound (b): It is the coating liquid containing the (A) component of a chemical polymer, and the (B) component of a polyamic acid.

  In the present invention, a preferred embodiment of the component (A) is a solvent-soluble polyimide obtained from a tetracarboxylic dianhydride and a diamine compound, and at least one amine selected from a specific amine compound (a) and an amine compound (b). It is an imidized polymer soluble in a solvent obtained by binding a compound as at least one of a side chain and a molecular end.

Specifically, the imidization weight soluble in a solvent, which is a product obtained by reacting {1} solvent-soluble polyimide with at least one amine compound selected from the following amine compound (a) and amine compound (b): Or a polyimide precursor obtained by reacting a diamine containing {2} tetracarboxylic dianhydride and the following amine compound (c). It contains an imidized polymer soluble in a solvent and a polyamic acid. In {1} and {2}, the polyamic acid is the same.
The amine compound (a) has one primary amino group selected from the formula [K1] and formula [K2] and at least one imino group selected from the formula [K3] and formula [K4] in the molecule. An amine compound,

アミン化合物（ｂ）は、分子内に、式［Ｋ１］及び式［Ｋ２］から選ばれる一級アミノ基を少なくとも２個有するアミン化合物である。

The amine compound (b) is an amine compound having at least two primary amino groups selected from the formulas [K1] and [K2] in the molecule.

In addition, in the formula [K3] and the formula [K4], for example, the bonding direction of —CH ₂ —NH— is reversed as in the relationship between X ¹ and X ² in formulas (i) and (ii) described later. In relation,
The amine compound (c) has at least one primary amino group selected from the formula [K1] and formula [K2] and at least one imino group selected from the formula [K3] and formula [K4] in the molecule. This is an amine compound.

In addition, when the amine compound (c) has one primary amino group represented by the formula [K1] or the formula [K2], it is the same as the amine compound (a), and the formula [K1] and the formula [K2 In the case of having at least two primary amino groups selected from the above, it is a compound contained in the amine compound (b).
Preferably, the amine compound (a) is represented by the following formula: —R ¹ —NH ₂ (R ¹ is —CH ₂ —, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, or an aliphatic ring. And an amino group represented by the following formula: —R ² —NH—R ³ — (R ² and R ³ are divalent organic groups, at least one of which is methylene). An amine compound having at least one imino group.

Preferably, the amine compound (b) is represented by the following formula: —R ¹ —NH ₂ (R ¹ is —CH ₂ —, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, or aliphatic. An amine compound having at least two amino groups represented by a ring.
Further preferably, the amine compound (c) is represented by the following formula: —R ¹ —NH ₂ (R ¹ is —CH ₂ —, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, or aliphatic. And at least one amino group represented by the following formula: —R ² —NH—R ³ — (R ² and R ³ are divalent organic groups, at least one of which is methylene) And an amine compound having at least one imino group.
As a specific example of the coating solution of {1}, a predetermined amount of either the amine compound (a) or the amine compound (b) is added to a polyimide solution and stirred at room temperature or under heating conditions. It is a solution obtained by mixing an imidized polymer soluble in the solvent of the obtained reaction product and a polyamic acid solution at an arbitrary ratio.
Moreover, as a specific example of the coating liquid of {2}, a solution of an imidized polymer obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride, a diamine, and the amine compound (c). And a solution obtained by mixing a polyamic acid solution in an arbitrary ratio.

The specific amine compound (a) and amine compound (b) used in the present invention have at least two points of action. One is a site chemically bonded to the solvent-soluble polyimide, and the other is a site that forms a hydrogen bond or salt formation with the polyamic acid. This improves the compatibility of the imidized polymer soluble in the solvent reacted with the specific amine compound and the polyamic acid, and suppresses phase separation when the coating solution is concentrated.
In the amine compound (a) or the amine compound (b), the primary amino group represented by the formula [K1] and the formula [K2] is an aliphatic amino group, and is an imide group with respect to the imide carbonyl group in the polyimide. If the imidation ratio of the polyimide is less than 100% as described later, in addition to the reaction described above, the carboxyl group of the amic acid group or the carboxy ester group of the amic acid ester group Are bonded by a reaction involving elimination of water or alcohol.
In the amino group represented by —R ¹ —NH ₂ contained in the amine compound (a) or the amine compound (b) that is preferred as described above, R ¹ is —CH ₂ —, —CH (CH ₃ ) —, — CH (CH ₂ CH ₃ ) — or an aliphatic ring is represented. Examples of the aliphatic ring include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, adamantane, decahydronaphthalene, and norobornane.
These amino groups are aliphatic amino groups and exhibit the characteristics as described above.
Therefore, R ^{1 of} this amino group is most preferably methylene because it increases the nucleophilicity of the amino group and has less steric hindrance. Among the aliphatic rings, cyclopropane, cyclobutane, cyclopentane, cyclohexane and the like are preferable.

On the other hand, the imino group represented by —CH ₂ —NH— or —NH—CH ₂ — contained in the amine compound (a) acts with a carboxyl group in the polyamic acid, such as hydrogen bonding or salt formation. Moreover, in the amine compound (a), it is sufficient that at least one imino group represented by —CH ₂ —NH— or —NH—CH ₂ — is present, but from the viewpoint of availability and stability of the compound. 1-4 are suitable, and 1-2 are especially preferable.
Similarly, the imino group represented by —R ² —NH—R ³ — contained in the amine compound (a) that is preferred as described above has functions such as hydrogen bonding and salt formation with the carboxyl group in the polyamic acid. To do. Accordingly, R ² and R ³ of this imino group need to have at least one of R ² and R ³ methylene because it is necessary to give the nitrogen atom of the imino group a certain electron density. When one side is methylene, the structure of the other side is not particularly limited. For example, —CH ₂ —, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, an aliphatic ring exemplified for R ¹ Or phenylene. Among these, methylene or an aliphatic ring is preferable. More preferably, both R ² and R ³ are methylene. In the amine compound (a), it is sufficient that at least one imino group represented by —R ² —NH—R ³ — is present, but 1 to 4 is appropriate from the viewpoint of the availability and stability of the compound. In particular, 1 to 2 is preferable.

  The amine compound (b) has at least two primary amino groups selected from the formulas [K1] and [K2]. In the case of such an amine compound, when the first primary amino group reacts with the solvent-soluble polyimide, the migration of the amine compound is suppressed, so that the remaining amino group becomes difficult to react with other solvent-soluble polyimides. As a result, the amino group that has not reacted with the solvent-soluble polyimide has the same action as the imino group contained in the amine compound (a).

In the amine compound (b), it is sufficient that the primary amino group has two or more, but 2 to 5 is appropriate from the viewpoint of availability and stability of the compound, and in particular, 2 to 3 are preferable. preferable. Moreover, it is preferable that the amine compound (b) further has one or more imino groups selected from the formula [K3] and the formula [K4] because the compatibility with the polyamic acid is further increased. This imino group is preferably an imino group represented by —R ² —NH—R ³ — like the amine compound (a). The definitions of R ² and R ³ are the same as in the amine compound (a).

In the coating solution of {2}, at the time of producing the soluble imidized polymer of the component (A), at least one primary amino group selected from the formula [K1] and the formula [K2] of the amine compound (c) is By reacting with tetracarboxylic dianhydride, the amine compound (c) is taken into the polyimide. One or more amino groups may be contained in the molecule, but 1 to 5 is appropriate from the viewpoint of availability and stability of the compound, and 1 to 2 is particularly preferable. Since the amine compound (c) having one amino group is located at either the side chain or the terminal of the polymer molecule, there is little steric hindrance when forming a hydrogen bond or salt formation with the polyamic acid. From the most preferred. Further, when the number of amino groups is 3 or more, the obtained soluble polyimide has a three-dimensional structure. When this coating solution is used as a liquid crystal alignment film, it is preferable that the main chain is less branched for the reason of obtaining uniform alignment of the liquid crystal, and therefore, two or less amino groups are preferable.
This amino group is preferably an amino group represented by —R ¹ —NH ₂ , similarly to the amine compound (a). The definition of R ¹ is the same as that of the amine compound (a).

On the other hand, the imino group selected from the formula [K3] and the formula [K4] contained in the amine compound (c) is the same as the imino group contained in the amine compound (a) described above with regard to its configuration, action and preferred form. is there. That is, an imino group represented by —R ² —NH—R ³ — is preferable, and the definitions of R ² and R ³ are the same as those of the amine compound (a).
More specifically, examples of the amine compound (a) in the present invention include amine compounds represented by the following formulas (i) and (ii).

ただし、式中のＲ^１は、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、もしくは−ＣＨ（ＣＨ_２ＣＨ_３）−のアルキレン、又は脂肪族環を表し、Ｘ^１は、単結合又は２価の有機基を表し、２価の有機基の具体例としては、アルキレン、脂肪族環、芳香族環、複素環及びこれらの組み合わせからなる有機基などが挙げられ、かつ、不飽和結合、エーテル結合（−Ｏ−）、ケトン結合（−ＣＯ−）、エステル結合（−ＣＯＯ−）、チオエーテル結合（−Ｓ−）、アミノ結合（−ＮＨ−）、アミド結合（−ＣＯＮＨ−）、シリル結合（−Ｓｉ−）、シロキサン結合（−ＳｉＯ−）などを含んでいてもよい。

In the formula, R ¹ represents —CH ₂ —, —CH (CH ₃ ) —, or —CH (CH ₂ CH ₃ ) —, an alkylene, or an aliphatic ring, and X ¹ represents a single bond or 2 Specific examples of divalent organic groups include alkylene, aliphatic rings, aromatic rings, heterocyclic rings, and organic groups composed of combinations of these, and unsaturated bonds, ethers. Bond (—O—), ketone bond (—CO—), ester bond (—COO—), thioether bond (—S—), amino bond (—NH—), amide bond (—CONH—), silyl bond ( -Si-), a siloxane bond (-SiO-), and the like may be included.

X ² is a monovalent organic group, and specific examples thereof include an alkyl group, an alkoxy group, a cycloaliphatic group, an aromatic group, a heterocyclic group, and an organic group composed of a combination thereof, and unsaturated. Bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), thioether bond (—S—), amino bond (—NH—), amide bond (—CONH—), A silyl bond (—Si—), a siloxane bond (—SiO—), or the like may be included.

Furthermore, X ² may form a heterocyclic structure with any one selected from —R ¹ —, —X ¹ —, —CH ₂ —, and —NH—.
In the above examples, examples of the aliphatic ring or cycloaliphatic group include ring structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, adamantane, decahydronaphthalene, and norobornane. It is done. Examples of the aromatic ring or aromatic group include ring structures such as benzene and naphthalene. Examples of the heterocyclic ring or heterocyclic group include ring structures such as pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyrroline, pyrrolidine, pyridine, and pyrimidine. Moreover, as an alkyl group, an alkoxy group, and alkylene, a C1-C20 alkyl group, an alkoxy group, and alkylene are mentioned.

X ¹ and X ² may have a substituent. Specific examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, and a carboxyl group.
Examples of the amine compound (b) in the present invention include amine compounds represented by the following formulas (iii) to (v).

ただし、式中のＲ^１は、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、もしくは−ＣＨ（ＣＨ_２ＣＨ_３）−のアルキレン、又は脂肪族環を表し、Ｈ_２Ｎ−Ｒ^１−と−Ｒ^１−ＮＨ_２のＲ^１は同一でも異なっていてもよい。

However, ^{R 1} in the _{formula, -CH 2 -, - CH (} CH 3) -, or -CH _(CH 2 _{CH 3)} - alkylene, or an aliphatic _ring, H 2 ^{N-R 1} - and ^{R 1} of -R ¹ -NH ₂ may be the same or different.

X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent a single bond or a divalent organic group, and specific examples of the divalent organic group include alkylene, aliphatic ring, and aromatic ring. And an organic group composed of a heterocyclic ring and a combination thereof, and an unsaturated bond, an ether bond (—O—), a ketone bond (—CO—), an ester bond (—COO—), a thioether bond (— S-), an amino bond (—NH—), an amide bond (—CONH—), a silyl bond (—Si—), a siloxane bond (—SiO—) and the like may be included.

In the above examples, examples of the aliphatic ring or cycloaliphatic group include ring structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, adamantane, decahydronaphthalene, and norobornane. It is done. Examples of the aromatic ring or aromatic group include ring structures such as benzene and naphthalene. Examples of the heterocyclic ring or heterocyclic group include ring structures such as pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyrroline, pyrrolidine, pyridine, and pyrimidine. Moreover, as alkylene, a C1-C20 alkylene is mentioned.
X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ may have a substituent. Specific examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, and a carboxyl group.
Examples of the amine compound (c) in the present invention include amine compounds represented by the following formulas (i), (ii), (iv) and (v).

ただし、式中のＲ^１は、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、もしくは−ＣＨ（ＣＨ_２ＣＨ_３）−のアルキレン、又は脂肪族環を表し、Ｈ_２Ｎ−Ｒ^１−と−Ｒ^１−ＮＨ_２のＲ^１は同一でも異なっていてもよい。

However, ^{R 1} in the _{formula, -CH 2 -, - CH (} CH 3) -, or -CH _(CH 2 _{CH 3)} - alkylene, or an aliphatic _ring, H 2 ^{N-R 1} - and ^{R 1} of -R ¹ -NH ₂ may be the same or different.

X ¹ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ represent a single bond or a divalent organic group, and specific examples of the divalent organic group include an alkylene, an aliphatic ring, and an aromatic ring. And an organic group composed of a heterocyclic ring and a combination thereof, and an unsaturated bond, an ether bond (—O—), a ketone bond (—CO—), an ester bond (—COO—), a thioether bond (— S-), an amino bond (—NH—), an amide bond (—CONH—), a silyl bond (—Si—), a siloxane bond (—SiO—) and the like may be included.
X ² is a monovalent organic group, and specific examples thereof include an alkyl group, an alkoxy group, a cycloaliphatic group, an aromatic group, a heterocyclic group, and an organic group composed of a combination thereof, and unsaturated. Bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), thioether bond (—S—), amino bond (—NH—), amide bond (—CONH—), A silyl bond (—Si—), a siloxane bond (—SiO—) and the like may be included.

In addition, X ² in the formulas (i) and (ii) may form a heterocyclic structure with any of —R ¹ —, —X ¹ —, —CH ₂ —, and —NH—.
In the above examples, examples of the aliphatic ring or cycloaliphatic group include ring structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, adamantane, decahydronaphthalene, and norobornane. It is done. Examples of the aromatic ring or aromatic group include ring structures such as benzene and naphthalene. Examples of the heterocyclic ring or heterocyclic group include ring structures such as pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyrroline, pyrrolidine, pyridine, and pyrimidine. Moreover, as an alkyl group, an alkoxy group, and alkylene, a C1-C20 alkyl group, an alkoxy group, and alkylene are mentioned.

X ¹ , X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ may have a substituent. Specific examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, and a carboxyl group.
From the viewpoint that the amine compound (a), the amine compound (b) or the amine compound (c) does not deteriorate the physical properties of the polyimide even in the film, the molecular weight of the compound is preferably 1000 or less, more preferably. 500 or less, particularly preferably 300 or less.
Specific examples of the amine compound (a) or the amine compound (b) include, but are not limited to, the following. Two or more amine compounds may be used in combination.

Specific examples of the amine compound (c) include No. 1 to No. 50, No. 71 to No. 76, No. 93 to No. 102, and No. 106 to No. 108. It is not limited to these. Two or more amine compounds may be used in combination.
In the coating solutions {1} and {2} of the present invention, the solvent-soluble polyimide and the imidized polymer soluble in the solvent are a polymer having an imide bond in the repeating unit, and an organic solvent. It refers to what can be dissolved.

In addition, a solvent-soluble polyimide used in the present invention and a solvent-soluble imidized polymer may be used in the present invention in which a part of the imide group contained in the repeating unit is ring-opened to form an amic acid group or an amic acid ester group. Included in the category. The ratio of the imide group contained in the polymer having these imide bonds can be expressed as an imidization ratio as shown in the following formula.
Imidation ratio = number of imide groups / (number of imide groups + number of amic acid groups + number of amic acid ester groups)
These imidization rates are determined by measuring the ¹ H-NMR obtained by dissolving the polyimide in d ₆ -DMSO (dimethyl sulfoxide-d ₆ ), and the proton peak derived from the structure that does not change even when the imide group is opened. It can be confirmed by comparing the integrated value of the proton peak of —NH— derived from the amic acid group and the amic acid ester group on the basis of the integrated value.

  The imidation ratio of the solvent-soluble polyimide used in the coating solution of the present invention and the imidized polymer soluble in the solvent is not particularly limited. Usually, the higher the imidization rate, the lower the solubility of the polyimide in the solvent. As a result, if it cannot be dissolved at the required concentration, the imidization rate may be lowered appropriately. Further, considering the purpose of using a polymer that has been imidized in advance, the imidation ratio is preferably 10% or more. Further, when used as a liquid crystal aligning agent, the imidation ratio is preferably 40% or more, more preferably 60% or more, and particularly preferably, because good liquid crystal orientation or good electrical characteristics can be obtained. 80% or more.

The molecular weight of the solvent-soluble polyimide and the imidized polymer soluble in the solvent is not particularly limited, but is 2,000 to 200,000 in terms of weight average molecular weight from the viewpoint of ease of handling and stability of characteristics when a film is formed. Is more preferable, and it is 4,000 to 50,000. The molecular weight is determined by GPC (gel permeation chromatography).
Although the structure of the solvent-soluble polyimide used in the coating solution of {1} of the present invention is not particularly limited, the following can be obtained relatively easily by using tetracarboxylic dianhydride and diamine as raw materials. A polyimide having a repeating unit represented by the formula (I) is preferred.

  The imidized polymer soluble in the solvent used in the coating solution of {2} of the present invention is a polyimide precursor obtained by reacting tetracarboxylic dianhydride and a diamine containing an amine compound (c). Although it is obtained by imidization, it is obtained using diamine as a main raw material, and has a polyimide having a repeating unit represented by the following formula (I) as a basic structure in the same manner as {1}.

Furthermore, the imidized polymer soluble in the solvent used in the coating solution {1} of the present invention contains a specific amine compound (a) in a part of the polyimide having a repeating unit represented by the following formula (I). ) And an amine compound (b) selected from the amine compound (b) have an amino group represented by —R ¹ —NH ₂ bonded to the imide carbonyl group in the polyimide by a reaction involving ring opening of the imide group. When the imidization ratio of the polyimide is less than 100%, the polyimide has a structure bonded to the carboxyl group of the amic acid group or the carboxy ester group of the amic acid ester group.

The imidized polymer soluble in the solvent used in the coating solution of {2} is an amine compound selected from a specific amine compound (c) and a polyimide having a repeating unit represented by the following formula (I) A part of a polyimide having an amino group represented by —R ¹ —NH ₂ reacting with tetracarboxylic dianhydride and incorporated into a polyimide as a molecular end or having a repeating unit represented by the formula (I) Are bonded to the imide carbonyl group in a ring-opened state or bonded to the carboxyl group of the amic acid group or the carboxy ester group of the amic acid ester group.

In the above formula (I), A represents a tetravalent organic group, and B represents a divalent organic group.
In the above formula (I), the structure of A is not particularly limited. Moreover, the structure of A may be one type or a plurality of types may be mixed. A specific example of A is as follows.

Among these, A-6, A-16, A-18 to A-22, and A-25 are preferable because high solubility can be obtained even with a polyimide having a high imidization rate.
Further, when 10 mol% or more of A has an alicyclic structure or an aliphatic structure such as A-1 to A-25, the voltage holding ratio of the liquid crystal cell is improved when a liquid crystal alignment film is formed, which is preferable. .
In the formula (I), the structure of B is not particularly limited. Moreover, the structure of B may be one type or a plurality of types may be mixed. A specific example of B is as follows.

Among these, when part or all of B is B-80 to B-101, the pretilt angle of the liquid crystal can be increased when the liquid crystal alignment film is formed.
The polyimide having the repeating unit represented by the above formula (I) corresponds to the tetracarboxylic dianhydride having the corresponding structure of A as in the following formula (II) and the following formula (III) according to a conventional method. It can be obtained by reacting with the diamine having the structure of B to be a polyimide precursor and dehydrating and ring-closing it.

When obtaining an imidized polymer soluble in the solvent used in the coating solution of {2}, the tetracarboxylic dianhydride of the above formula (II), the diamine of the above formula (III), and the amine It can be obtained by reacting the compound (c) with a polyimide precursor and subjecting it to dehydration ring closure. If the amount of the amine compound (c) used is too small, the effect of the moisture absorption stability of the coating solution is not sufficiently exhibited. Therefore, the amount of the amine compound (c) is 1 mol% or more in the total amount of the diamine of formula (III) and the amine compound (c). Preferably, it is 2 mol%. The amine compound (c) having one primary amino group contained in the molecule is preferably 15 mol% or less, more preferably 10 mol% or less because the molecular weight of the imidized polymer soluble in the resulting solvent is limited. And particularly preferably 5 mol% or less. Since the amine compound (c) having two or more primary amino groups contained in the molecule plays the role of a diamine of the formula (III), the total amount of the diamine of the formula (III) and the amine compound (c) can be reduced with this. It may be replaced.
The reaction for obtaining the polyimide precursor is usually performed at −20 to 150 ° C., preferably 0 to 100 ° C., more preferably 10 to 80 ° C. in an organic solvent.

  At this time, the ratio of the tetracarboxylic dianhydride and the diamine used is such that the acid anhydride group contained in the tetracarboxylic dianhydride is 0.5 to 1 with respect to 1 equivalent of the amino group contained in the diamine. It is preferably 5 equivalents, more preferably 0.8 to 1.2 equivalents. In addition, when making an amine compound (c) react, the ratio of the acid anhydride group contained in the tetracarboxylic dianhydride with respect to the amino group which combined the amino group contained in the diamine and the amino group contained in the amine compound And

The organic solvent used in the above reaction is not particularly limited as long as the generated polyimide precursor is dissolved. For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, etc. Can be mentioned. These may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polyamic acid, it may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate. In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the generated polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.
Common methods for dehydrating and ring-closing polyimide precursors include thermal imidization by heating the polyimide precursor solution as it is, and chemical imidization by adding a catalyst to the polyimide precursor solution, but imidization at a relatively low temperature. Chemical imidization in which the reaction proceeds is preferable because the molecular weight of the resulting polyimide is less likely to decrease.

  Chemical imidation can be performed by stirring the polyimide precursor in an organic solvent in the presence of a basic catalyst and an acid anhydride. The reaction temperature at this time is -20-250 degreeC, Preferably it is 0-180 degreeC. The higher the reaction temperature, the faster the imidization proceeds, but if it is too high, the molecular weight of the polyimide may decrease. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times the amidic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amic acid group. Is double. If the amount of the basic catalyst or acid anhydride is small, the reaction does not proceed sufficiently. If the amount is too large, it becomes difficult to completely remove the reaction after completion of the reaction. Examples of the basic catalyst to be used include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated. As an organic solvent, the solvent used at the time of the polyamic acid polymerization reaction mentioned above can be used. The imidation ratio by chemical imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

Since the added catalyst remains in the solution of the polyimide solution obtained in this way, it is preferable to throw this polyimide solution into a stirring poor solvent and collect the precipitate. Although it does not specifically limit as a poor solvent used for precipitation collection | recovery of a polyimide, Methanol, acetone, hexane, a butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene etc. can be illustrated. The polyimide precipitated by adding it to a poor solvent can be recovered by filtration, washing and drying at room temperature or under reduced pressure at normal temperature or by heating.
In the coating solution of {1}, the reaction between the solvent-soluble polyimide and the amine compound (a) or the amine compound (b) can be performed as follows.
First, solvent-soluble polyimide is dissolved in an organic solvent to obtain a solution. At this time, if the polyimide is difficult to dissolve, it may be heated. Since the molecular weight of a polyimide may fall when the temperature to heat is too high, 30-100 degreeC is preferable.

The concentration of the polyimide solution is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 15% by mass because the polyimide and the amine compound can be reacted efficiently and uniformly. 10% by mass. Further, when the amine compound has two or more amino groups represented by -R ¹ -NH ₂ , if the polyimide concentration is too high, the polyimides form a three-dimensional structure with the amine compound and the solubility is high. In this case, the content is preferably 5% by mass or less.

  The solvent is not particularly limited as long as the resin is completely dissolved within the above concentration range. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetra Examples include methylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone. Two or more kinds of these solvents may be mixed and used. However, since lactone solvents such as γ-butyrolactone are likely to react with aliphatic amino groups and consume amine compounds, solvents such as N, N-dimethylformamide and N-methyl-2-pyrrolidone may be used. It is preferable to use it. If you want to use a lactone solvent such as γ-butyrolactone as the main solvent, after reacting the amine compound and polyimide using a solvent other than the lactone once, this solution is put into a suitable poor solvent and recovered. It may be dissolved again in the lactone solvent. Examples of the poor solvent at this time include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. The polyimide precipitated by adding it to a poor solvent can be recovered by filtration, washing and drying at room temperature or under reduced pressure at normal temperature or by heating.

Next, an amine compound selected from the amine compound (a) and the amine compound (b) is added to the polyimide solution, and the mixture is stirred at room temperature or under heating conditions.
If the addition amount of the amine compound is too small, the effect of the moisture absorption stability of the coating solution will not be sufficiently exerted, and if it is too large, the properties of the coating film will be deteriorated, for example, in the liquid crystal alignment film, the liquid crystal alignment will decrease. From the reason it falls, 1-15 mass parts is preferable with respect to 100 mass parts of solvent-soluble polyimide, More preferably, it is 2-10 mass parts, Most preferably, it is 2-5 mass parts. The amine compound may be added directly to the solvent-soluble polyimide solution, but it is preferable to add the amine compound after forming a solution with a concentration of 0.1 to 10% by mass with an appropriate solvent. Examples of the solvent include the solvent of the solvent-soluble polyimide described above. Also in this case, since lactone solvents such as γ-butyrolactone are likely to react with an aliphatic amino group and consume an amine compound, such as N, N-dimethylformamide and N-methyl-2-pyrrolidone. It is preferable to use a solvent.

The temperature at the time of reaction is preferably 25 to 150 ° C., more preferably 30 to 100 ° C., particularly preferably 40 to 80 because the polyimide and the amine compound react efficiently and side reactions do not easily occur. ° C. If the temperature is too high, the soluble polyimide can be hydrolyzed.
The reaction time varies depending on the reactivity between the solvent-soluble polyimide and the amine compound and the reaction temperature, but a standard example is 40 to 80 ° C. and 6 to 48 hours.
The structure of the polyamic acid used in the coating solution of the present invention is not particularly limited, but it can be obtained relatively simply by using tetracarboxylic dianhydride and diamine as raw materials. Polyamic acids having the repeating units shown are preferred.

The above formula (IV) A ′ represents a tetravalent organic group, and B ′ represents a divalent organic group.
The polyamic acid having a repeating unit represented by the above formula (IV) is a tetracarboxylic dianhydride having a structure of A ′, as shown in the method for synthesizing a polyimide precursor for obtaining the solvent-soluble polyimide described above. Can be obtained by reacting a product and a diamine having the structure of B ′ in an organic solvent.

The molecular weight of the polyamic acid is not particularly limited, but is preferably 2,000 to 200,000, more preferably 5,000 to 100 in terms of weight average molecular weight from the viewpoints of ease of handling and stability of characteristics when a film is formed. , 000. The molecular weight is determined by GPC (gel permeation chromatography).
In the above formula (IV), the structure of A ′ is not particularly limited. Further, the structure of A ′ may be one type, or may have a different structure of A ′ and a plurality of different types as a repeating unit may be mixed. If the specific example of A 'is given, the structure illustrated by said A will be mentioned.
In the formula (IV), the structure of B ′ is not particularly limited. Further, the structure of B ′ may be one type, or may have a different B ′ structure, and a plurality of different types may be mixed as a repeating unit. If the specific example of B 'is given, the structure illustrated by said B will be mentioned.

  In order to obtain the coating solution of the present invention, an imidized polymer soluble in a solvent of a product obtained by reacting a solvent-soluble polyimide with an amine compound selected from the amine compounds (a) and (b) (hereinafter referred to as “specific”). The solution of the polyamic acid may be mixed at an arbitrary ratio. Further, an imidized polymer soluble in a solvent obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a diamine containing an amine compound (c) (hereinafter also referred to as a specific polyimide). And a solution of polyamic acid may be mixed at an arbitrary ratio.

  The solution of the specific product may be used as it is as the reaction solution of the specific product or may be used by dissolving the reaction solution in an appropriate poor solvent and recovering the specific product, and then dissolving it again in the solvent. Examples of the poor solvent at this time include water, methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. As a solvent for re-dissolution, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide , Tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone and the like. These redissolving solvents can also be used as solvents for dissolving the specific polyimide.

In the coating solution of the present invention, the specific product and the specific polyimide may be used in combination. The ratio of the specific product, the specific polyimide, and the polyamic acid is arbitrary, but because the liquid crystal alignment film having good characteristics can be obtained, the polyamic acid in the mass of the specific product, the specific polyimide, and the polyamic acid is combined. The ratio is preferably 20 to 99% by mass, more preferably 40 to 95% by mass, and particularly preferably 60 to 90% by mass.
That is, the ratio of the polyamic acid in the mass of the specific product and / or the specific polyimide and the polyamic acid is preferably 20 to 99% by mass, more preferably 40 to 95% by mass, and particularly preferably 60 to 90% by mass.

  Further, the concentration of the solid component in the coating solution can be appropriately changed depending on the thickness of the coating film to be formed, but in order to obtain a uniform coating film, 0.1% by mass or more is preferable, From the viewpoint of storage stability, it is preferably 30% by mass or less. Moreover, 1-10 mass% is preferable because the coating film of suitable thickness is obtained as a liquid crystal aligning film.

  The solvent contained in the coating solution of the present invention may contain a solvent for improving the printability in addition to the above-described re-dissolving solvent for the specific product. Specific examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and 1-butoxy-2-propanol. 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- Low surface tension such as (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester The solvent having the like. It is known that the coating film uniformity is improved at the time of application to the substrate by mixing these appropriately, and it is also suitably used in the coating liquid of the present invention.

When the coating liquid of the present invention is used as a liquid crystal aligning agent, when an amide solvent such as N, N-dimethylformamide or N-methyl-2-pyrrolidone is contained in an amount of 50% by mass or more of the coating liquid, When a thin film is formed by a printing method such as flexographic printing, the film thickness uniformity is improved, which is preferable.
The liquid crystal aligning agent of this invention consists of the said coating liquid, In order to improve the adhesiveness of the liquid crystal aligning film with respect to a board | substrate, you may add additives, such as a silane coupling agent. Further, since the liquid crystal aligning agent needs to form a thin film having a thickness of 300 nm or less on the substrate, it is preferable to filter with a membrane filter having a pore diameter of 0.1 μm to 1 μm when the coating liquid is used as the liquid crystal aligning agent. .

  Since the liquid crystal aligning agent of the present invention increases the entanglement of the polymer by appropriately suppressing phase separation between the imidized polymer soluble in the solvent and the polyamic acid when it is formed into a coating film, On the other hand, it has the effect that it becomes difficult to cut. Furthermore, compared with the case where no amine compound is used, the electrical characteristics of the liquid crystal display element, such as the ease of draining the stored charge and the voltage holding ratio, tend to be improved.

The liquid crystal alignment film of the present invention is a coating film obtained by applying the liquid crystal aligning agent obtained as described above to a substrate, drying and baking, and is used for aligning liquid crystals in a predetermined direction.
The substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. It is preferable to use a substrate on which is formed from the viewpoint of simplification of the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

Examples of the method for applying the liquid crystal aligning agent include spin coating, printing, and ink jet methods. From the viewpoint of productivity, transfer printing methods such as flexographic printing are widely used industrially. It is also suitably used in liquid crystal aligning agents.
The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, a drying process is included. Is preferred. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. If a specific example is given, the method of drying on a hotplate of 50-150 degreeC, Preferably 80-120 degreeC for 0.5 to 30 minutes, Preferably it is 1 to 5 minutes is taken.
Although baking of the board | substrate which apply | coated the liquid crystal aligning agent can be performed at 100-350 degreeC arbitrary temperatures, Preferably it is 150 to 300 degreeC, More preferably, it is 180 to 250 degreeC. Further, it is more preferable that the baking is performed at a temperature higher by 10 ° C. or more than the heat treatment temperature such as sealing agent curing required in the liquid crystal cell manufacturing process.

If the thickness of the coating film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so it is preferably 5 to 300 nm, more preferably 10-100 nm.
When the liquid crystal is horizontally or tilted, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.
The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.

  To give an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, spray spacers on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside. Examples include a method of bonding the other substrate and injecting liquid crystal under reduced pressure, or a method of sealing the substrate by bonding the liquid crystal after dropping the liquid crystal on the liquid crystal alignment film surface on which spacers are dispersed. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The liquid crystal display element of the present invention includes a TN liquid crystal display element, an STN liquid crystal display element, a TFT liquid crystal display element, an OCB liquid crystal display element, and a nematic liquid crystal such as a horizontal electric field type liquid crystal display element and a vertical alignment type liquid crystal display element. It is suitably used for display elements using the various methods used. Further, by selecting a liquid crystal to be used, it can be used for a ferroelectric and antiferroelectric liquid crystal display element.
The present invention will be described in more detail with reference to the following examples, but the present invention should not be construed as being limited thereto.

  In the synthesis examples, the abbreviations and structures of tetracarboxylic dianhydride and diamine used in the synthesis of solvent-soluble polyimide, solvent-immobilized imidized polymer, or polyamic acid are shown below.

The abbreviations of organic solvents used in Synthesis Examples, Examples, etc. are as follows.
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve GBL: γ-butyrolactone Abbreviations of amine compounds used in the examples are as follows. (No. in parentheses is the number of the amine compound shown in the specification.)
AM1: (No.94): Triethylenetetraamine AM2: (No.37): (Aminoethylaminomethyl) phenethyltrimethoxysilane AM3: (No.32): N- (2-aminoethyl) -3-amino Propyltrimethoxysilane AM4: (No. 47): (3-Trimethoxysilylpropyl) diethylenetriamine AM5: (No.34): N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane AM6: (No. 35): N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane AM7: (No. 95): N, N'-bis (2-aminoethyl) -1,3-propanediamine AM8: (No .36): N- (2-aminoethyl) -11-aminoundecyltrimethoxysilane AM9: (No.38): N- (6-aminohexyl) aminopropyltrimethoxysilane AM10: (No.55): 1,6-diaminohexane AM11: (No. 71): Diethylenetriamine AM12: (No. 73): Di Lopylenetriamine AM13: (No.11): n-propyl-1,3-propanediamine AM14: (No.51): ethylenediamine AM15: (No.56): 1,12-diaminododecane AM16: (No.65) : P-xylylenediamine AM17: (No. 27): 1- (2-aminoethyl) piperazine

<Measurement of molecular weight of polymer>
The molecular weights of the solvent-soluble polyimide, the imidized polymer soluble in the solvent, and the polyamic acid in the synthesis examples are as follows: room temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Shodex, column (KD-803) manufactured by Shodex , KD-805) and measured as follows.
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr • H2O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF ) Is 10ml / L)
Flow rate: 1.0 mL / min Standard sample for preparing calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratory.

<Measurement of imidization ratio>
The imidation ratio of the solvent-soluble polyimide in the synthesis example and the imidized polymer soluble in the solvent was measured as follows. Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.), add 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS (tetramethylsilane) mixture), It was completely dissolved by applying sonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNM-ECA500) manufactured by JEOL Datum. The imidation rate is determined based on protons derived from a structure that does not change before and after imidation as a reference proton, and the peak integrated value of this proton and the proton peak integrated value derived from the NH group of the amic acid that appears in the vicinity of 9.5 to 10.0 ppm. Was obtained by the following equation.
Imidation ratio (%) = (1−α · x / y) × 100
In the above formula, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and α is one NH group proton of the amic acid in the case of the polyamic acid (imidation rate is 0%). The number ratio of the reference protons.

(Synthesis Example 1)
A polyamic acid solution was prepared by reacting 150.14 g (0.5 mol) of TDA, 48.67 g (0.45 mol) of DA1, and 18.83 g (0.05 mol) of DA2 in 1233 g of NMP at 50 ° C. for 24 hours. This polyamic acid solution was diluted to 5% by mass with NMP, and 237.9 g of pyridine and 510.6 g of acetic anhydride were further added as an imidization catalyst, followed by reaction at 40 ° C. for 3 hours. This solution was put into 17.4 L of methanol, and the resulting precipitate was filtered off and dried to obtain a white polyimide powder.
The obtained solvent-soluble polyimide had a number average molecular weight of 9,273 and a weight average molecular weight of 18,815. The imidation ratio was 84%.

(Synthesis Example 2)
A polyamic acid solution obtained by reacting 98.05 g (0.5 mol) of CBDA, 95.98 g (0.44 mol) of PMDA, and 198.27 g (1.0 mol) of DA3 in a mixed solvent of NMP 1111 g and GBL 1111 g at room temperature for 5 hours. Was prepared. This polyamic acid had a number average molecular weight of 11,067 and a weight average molecular weight of 26,270.

{Example 1}
3 g of the polyimide powder obtained in Synthesis Example 1 was dissolved in 34.5 g of NMP by stirring at 50 ° C. for 20 hours. To this solution is added 3.0 g (0.15 g as an amine compound) of a 5 mass% NMP solution of triethylenetetraamine (No. 94 amine compound), and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of NMP was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 5 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 2 to prepare 6% by mass of polyamic acid, 59% by mass of NMP, 20% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating solution is NMP / GBL / BCS = 66/16/12 in mass ratio.

(Synthesis Example 3)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA and 19.83 g (0.1 mol) of DA3 in 283 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.1 g of pyridine and 15.4 g of acetic anhydride were further added as an imidization catalyst, and reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 13,651 and a weight average molecular weight of 48,092. The imidation ratio was 81%.

{Example 2}
A coating solution of the present invention was obtained in the same manner as in Example 1 except that the polyimide powder obtained in Synthesis Example 3 was used.
{Examples 3-29}
A coating solution of the present invention was obtained in the same manner as in Example 1 except that the addition amount or type of the amine compound was changed as follows. When 3 parts by mass of the amine compound is added, a 3% by mass NMP solution of the amine compound is added. When 2 parts by mass of the amine compound is added, 2% by mass NMP solution is added, and when 10 parts by mass is added, the same 10% by mass NMP solution is added. When adding 1 part by mass, the same 1% by mass NMP solution was added.
Example No. Amine compound addition amount (parts by mass)
1 AM1 0.15g (5)
3 AM1 0.09g (3)
4 AM1 0.06g (2)
5 AM2 0.09g (3)
6 AM2 0.15g (5)
7 AM2 0.30g (10)
8 AM3 0.15g (5)
9 AM3 0.30g (10)
10 AM4 0.15g (5)
11 AM4 0.30g (10)
12 AM5 0.09g (3)
13 AM5 0.15 g (5)
14 AM5 0.30 g (10)
15 AM6 0.15g (5)
16 AM6 0.30g (10)
17 AM7 0.15 g (5)
18 AM8 0.15 g (5)
19 AM8 0.30 g (10)
20 AM9 0.15 g (5)
21 AM10 0.15g (5)
22 AM11 0.03g (1)
23 AM11 0.09 g (3)
24 AM12 0.09g (3)
25 AM13 0.15g (5)
26 AM14 0.15 g (5)
27 AM15 0.15 g (5)
28 AM16 0.15g (5)
29 AM17 0.15 g (5)

{Comparative Example 1}
In Example 1, compared with Example 1, except that the solvent-soluble polyimide solution was diluted to 6% by mass with NMP without adding an amine compound, and this was mixed with a dilute solution of polyamic acid. A coating solution for was obtained.
{Comparative Example 2}
In Example 1, a coating solution for comparison was obtained in the same manner as in Example 1 except that 3-aminopropylmethyldiethoxysilane was used as the amine compound.
{Comparative Example 3}
A coating solution for comparison was obtained in the same manner as in Example 1 except that 2- (4-aminophenyl) ethylamine was used as the amine compound in Example 1.
{Comparative Example 4}
A coating solution for comparison was obtained in the same manner as in Example 1 except that bis (trimethoxysilylpropyl) amine was used as the amine compound in Example 1.
{Comparative Example 5}
A coating solution for comparison was obtained in the same manner as in Example 1 except that N-methylaminopropyltrimethoxysilane was used as the amine compound in Example 1.
<Evaluation of moisture absorption stability>
About 0.1 ml of each of the coating solutions prepared in the above Examples or Comparative Examples was dropped on a Cr film-formed glass substrate (chromium-deposited glass substrate) and left in an environment at a temperature of 23 ° C. and a humidity of 50%. The vicinity of the end and the center of the droplet were observed with a microscope every hour. The observation was performed at a magnification of 100 times near the edge of the droplet and at a magnification of 50 times near the center of the droplet.
As a result, in the coating liquids of Examples 1 to 29, no agglomerates were observed even after 6 hours, whereas in the coating liquids of Comparative Examples 1 to 5, Aggregates were observed near the center.

{Example 30}
In Example 1, the dilute solution of polyamic acid to be mixed was prepared in the same manner as in Example 1 except that the polyamic acid was adjusted to 6% by mass, NMP 39.5% by mass, GBL 39.5% by mass, and BCS 15% by mass. Thus, the coating solution of the present invention was obtained. The solvent composition of this coating solution is NMP / GBL / BCS = 50.3 / 31.6 / 12 in mass ratio.
{Example 31}
In Example 1, the dilute solution of polyamic acid to be mixed was prepared in the same manner as in Example 1 except that the polyamic acid was prepared to be 6% by mass, NMP was 20% by mass, GBL was 59% by mass, and BCS was 15% by mass. Thus, the coating solution of the present invention was obtained. The solvent composition of this coating solution is NMP / GBL / BCS = 34.7 / 47.2 / 12 by mass ratio.

{Example 32}
3 g of the polyimide powder obtained in Synthesis Example 1 was dissolved in 34.5 g of GBL by stirring at 50 ° C. for 20 hours. To this solution is added 3.0 g (0.15 g as an amine compound) of a 5 mass% GBL solution of triethylenetetraamine (No. 94 amine compound), and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of GBL was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 5 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 2 to prepare 6% by mass of polyamic acid, 20% by mass of NMP, 59% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating liquid is NMP / GBL / BCS = 16/66/12 in mass ratio.

{Examples 33 to 36}
A coating solution of the present invention was obtained in the same manner as in Example 30 except that the type of amine compound was changed as follows.
Example No. Amine compound 33 AM2
34 AM5
35 AM7
36 AM10

{Examples 37 to 39}
Except having changed the kind of amine compound as follows, it carried out similarly to Example 31, and obtained the coating liquid of this invention.
Example No. Amine compound 37 AM2
38 AM5
39 AM7

{Examples 40 to 46}
A coating solution of the present invention was obtained in the same manner as in Example 32 except that the type of amine compound was changed as follows.
Example No. Amine compound 40 AM2
41 AM3
42 AM4
43 AM5
44 AM6
45 AM7
46 AM10
(Synthesis Example 4)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.46 g (0.0875 mol) of DA1, and 4.71 g (0.0125 mol) of DA2 in 251 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 8.1 g of pyridine and 17.3 g of acetic anhydride were further added as an imidization catalyst, followed by reaction at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 9,195 and a weight average molecular weight of 19,235. The imidation ratio was 83%.

(Synthesis Example 5)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 5.65 g (0.015 mol) of DA2 in 254 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 17.1 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 9,324 and a weight average molecular weight of 19,244. The imidation ratio was 83%.

(Synthesis Example 6)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1 and 5.23 g (0.015 mol) of DA4 in 252 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 8.0 g of pyridine and 17.2 g of acetic anhydride were further added as an imidization catalyst, followed by reaction at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 9,834 and a weight average molecular weight of 21,659. The imidation ratio was 83%.

(Synthesis Example 7)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 8.56 g (0.08 mol) of DA1, and 5.85 g (0.02 mol) of DA5 in 252 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 8.0 g of pyridine and 17.2 g of acetic anhydride were further added as an imidization catalyst, followed by reaction at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 9,111 and a weight average molecular weight of 18,045. The imidation ratio was 83%.

(Synthesis Example 8)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 8.65 g (0.08 mol) of DA1, and 7.61 g (0.02 mol) of DA6 in 185 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 10.3 g of pyridine and 22.1 g of acetic anhydride were further added as an imidation catalyst, followed by reaction at 35 ° C. for 3 hours. This solution was poured into 0.8 L of methanol, and the resulting precipitate was filtered off and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 6,446 and a weight average molecular weight of 13,971. The imidation ratio was 74%.

(Synthesis Example 9)
30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 5.71 g (0.015 mol) of DA6 were reacted in 255 g of NMP at 50 ° C. for 24 hours to prepare a polyamic acid solution. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 17.0 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 35 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 7,943 and a weight average molecular weight of 14,365. The imidation ratio was 76%.

(Synthesis Example 10)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 6.11 g (0.015 mol) of DA7 in 257 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 16.9 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 5,735 and a weight average molecular weight of 12,670. The imidation ratio was 83%.

(Synthesis Example 11)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 5.92 g (0.015 mol) of DA8 in 256 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 17.0 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 8,495 and a weight average molecular weight of 22,294. The imidation ratio was 84%.

(Synthesis Example 12)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 6.04 g (0.015 mol) of DA9 in 257 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 16.9 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 8,775 and a weight average molecular weight of 23,308. The imidation ratio was 84%.

(Synthesis Example 13)
30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 5.44 g (0.015 mol) of DA10 were reacted in 253 g of NMP at 50 ° C. for 24 hours to prepare a polyamic acid solution. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 8.0 g of pyridine and 17.1 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 7,367 and a weight average molecular weight of 18,959. The imidation ratio was 84%.

(Synthesis Example 14)
30.03 g (0.1 mol) of TDA, 9.19 g (0.085 mol) of DA1, and 5.80 g (0.015 mol) of DA11 were reacted in NMP 255 g at 50 ° C. for 24 hours to prepare a polyamic acid solution. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.9 g of pyridine and 17.0 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 7,203 and a weight average molecular weight of 18,298. The imidation ratio was 84%.

(Synthesis Example 15)
30.03 g (0.1 mol) of TDA, 12.26 g (0.09 mol) of DA12 and 3.77 g (0.01 mol) of DA2 were reacted in 261 g of NMP at 50 ° C. for 24 hours to prepare a polyamic acid solution. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 7.7 g of pyridine and 16.6 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 8,634 and a weight average molecular weight of 17,655. The imidation ratio was 81%.

(Synthesis Example 16)
A polyamic acid solution was prepared by reacting 30.03 g (0.1 mol) of TDA and 19.83 g (0.1 mol) of DA13 in 329 g of NMP at 50 ° C. for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 6.1 g of pyridine and 13.1 g of acetic anhydride were further added as an imidization catalyst, followed by reaction at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 18,197 and a weight average molecular weight of 70,609. The imidization ratio was 90%.

(Synthesis Example 17)
A polyamic acid solution was prepared by reacting 19.22 g (0.098 mol) of CBDA, 16.26 g (0.08 mol) of DA14 and 5.85 g (0.02 mol) of DA5 in 234 g of NMP at room temperature for 24 hours. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, and 2.3 g of pyridine and 5.5 g of acetic anhydride were further added as an imidation catalyst, followed by reaction at 50 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 12,988 and a weight average molecular weight of 30,324. The imidation ratio was 94%.

(Synthesis Example 18)
TDA 15.02 g (0.05 mol), BODA 12.51 g (0.05 mol), DA1 9.73 g (0.09 mol), DA2 3.77 g (0.01 mol) in NMP 164 g at 35 ° C. for 24 hours. A polyamic acid solution was prepared by reaction. 50 g of this polyamic acid solution was diluted to 7% by mass with NMP, 9.6 g of pyridine and 6.2 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 100 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained solvent-soluble polyimide had a number average molecular weight of 12,808 and a weight average molecular weight of 32,511. Further, the imidization ratio was 85%.

(Synthesis Example 19)
A polyamic acid solution was prepared by reacting 18.43 g (0.094 mol) of CBDA and 19.83 g (0.1 mol) of DA3 in a mixed solvent of 108 g of NMP and 108 g of GBL at room temperature for 5 hours. This polyamic acid had a number average molecular weight of 16,951 and a weight average molecular weight of 37,292.

(Synthesis Example 20)
A polyamic acid solution was prepared by reacting 18.43 g (0.094 mol) of CBDA and 20.02 g (0.1 mol) of DA15 in a mixed solvent of 109 g of NMP and 109 g of GBL at room temperature for 5 hours. This polyamic acid had a number average molecular weight of 15,139 and a weight average molecular weight of 31,565.

(Synthesis Example 21)
A polyamic acid solution was prepared by reacting 18.04 g (0.092 mol) of CBDA and 19.93 g (0.1 mol) of DA16 in a mixed solvent of 171 g of NMP and 171 g of GBL at room temperature for 5 hours. This polyamic acid had a number average molecular weight of 20,821 and a weight average molecular weight of 49,970.

{Example 47}
3 g of the polyimide powder obtained in Synthesis Example 4 was dissolved in 34.5 g of NMP by stirring at 50 ° C. for 20 hours. To this solution, 3.0 g (0.09 g as an amine compound) of a 3 mass% NMP solution of triethylenetetraamine (No. 94 amine compound) is added, and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of NMP was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 3 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 2 to prepare 6% by mass of polyamic acid, 59% by mass of NMP, 20% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating liquid is Example NoNMP / GBL / BCS = 66/16/12 in mass ratio.

{Examples 48 to 58}
A coating solution of the present invention was obtained in the same manner as in Example 47 except that the polyimide powder was changed as follows.
Example 48 Polyimide powder obtained in Synthesis Example 5 Example 49 Polyimide powder obtained in Synthesis Example 6 Example 50 Polyimide powder obtained in Synthesis Example 7 Example 51 Polyimide powder obtained in Synthesis Example 8 Example 52 Synthesis Example 9 Example 53 Polyimide powder obtained in Synthesis Example 10 Example 54 Polyimide powder obtained in Synthesis Example 11 Example 55 Polyimide powder obtained in Synthesis Example 12 Example 56 Polyimide powder obtained in Synthesis Example 13 Example 57 Polyimide powder obtained in Synthesis Example 14 Example 58 Polyimide powder obtained in Synthesis Example 15

{Example 59}
3 g of the polyimide powder obtained in Synthesis Example 16 was dissolved in 34.5 g of GBL by stirring at 50 ° C. for 20 hours. To this solution, 3.0 g (0.15 g as an amine compound) of a 3 mass% GBL solution of triethylenetetraamine (No. 94 amine compound) is added, and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of GBL was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 3 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 19 to prepare 6% by mass of polyamic acid, 20% by mass of NMP, 59% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating liquid is NMP / GBL / BCS = 16/66/12 in mass ratio.

{Example 60}
3 g of the polyimide powder obtained in Synthesis Example 17 was dissolved in 34.5 g of GBL by stirring at 50 ° C. for 20 hours. To this solution, 3.0 g (0.15 g as an amine compound) of a 3 mass% GBL solution of triethylenetetraamine (No. 94 amine compound) is added, and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of GBL was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 3 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 20 to prepare 6% by mass of polyamic acid, 20% by mass of NMP, 59% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating liquid is NMP / GBL / BCS = 16/66/12 in mass ratio.

{Example 61}
3 g of the polyimide powder obtained in Synthesis Example 18 was stirred and dissolved in 23.5 g of NMP and 23.5 g of GBL at 50 ° C. for 20 hours. To this solution was added 3.0 g (0.03 g as an amine compound) of a 1% by weight GBL solution of (aminoethylaminomethyl) phenethyltrimethoxysilane (No. 37 amine compound), and the polyimide concentration in this solution was further increased. GBL 7.0g was added so that it might become 5 mass%, and it stirred at 50 degreeC for 20 hours. The addition amount of the amine compound at this time is 1 mass part with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 20 to prepare a polyamic acid of 5% by mass, NMP of 17.75% by mass, GBL of 52.25% by mass, and BCS of 25% by mass.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating solution is NMP / GBL / BCS = 22/53/20 by mass ratio.

{Example 62}
3 g of the polyimide powder obtained in Synthesis Example 1 was dissolved in 34.5 g of NMP by stirring at 50 ° C. for 20 hours. To this solution, 3.0 g (0.09 g as an amine compound) of a 3 mass% NMP solution of triethylenetetraamine (No. 94 amine compound) is added, and the polyimide concentration in this solution is 6 mass%. Then, 9.5 g of NMP was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 3 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 19 to prepare 6% by mass of polyamic acid, 59% by mass of NMP, 20% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating solution is NMP / GBL / BCS = 66/16/12 in mass ratio.

{Example 63}
In Example 62, NMP, GBL and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 21 as a dilute solution of the polyamic acid to be mixed, and the polyamic acid was 6 mass%, NMP was 39.5 mass%, and GBL was 39.5 mass%. The coating solution of the present invention was obtained in the same manner as in Example 62 except that the BCS was adjusted to 15% by mass. The solvent composition of this coating solution is NMP / GBL / BCS = 50.3 / 31.6 / 12 in mass ratio.

(Synthesis Example 22)
A polyamic acid solution was prepared by reacting 9.81 g (0.05 mol) of CBDA, 9.60 g (0.044 mol) of PMDA, and 19.83 g (0.1 mol) of DA3 in 222 g of NMP at room temperature for 5 hours. This polyamic acid had a number average molecular weight of 10,893 and a weight average molecular weight of 25,972.

{Example 64}
3 g of the polyimide powder obtained in Synthesis Example 1 was dissolved in 34.5 g of NMP by stirring at 50 ° C. for 20 hours. To this solution was added 3.0 g (0.30 g as an amine compound) of a 10 mass% GBL solution of (aminoethylaminomethyl) phenethyltrimethoxysilane (No. 37 amine compound), and the polyimide concentration in this solution was further increased. NMP 9.5g was added so that it might become 6 mass%, and it stirred at 50 degreeC for 20 hours. The addition amount of the amine compound at this time is 3 mass parts with respect to 100 mass parts of polyimides.
NMP and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 22 to prepare a polyamic acid of 6% by mass, NMP of 79% by mass, and BCS of 15% by mass.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating solution is NMP / BCS = 82/12 in mass ratio.

{Example 65}
3 g of the polyimide powder obtained in Synthesis Example 1 was dissolved in 34.5 g of GBL by stirring at 50 ° C. for 20 hours. To this solution is added 3.0 g (0.15 g as an amine compound) of a 2% GBL solution of triethylenetetraamine (No. 94 amine compound), and the polyimide concentration in this solution is 6% by mass. Then, 9.5 g of GBL was added and stirred at 50 ° C. for 20 hours. The addition amount of the amine compound at this time is 2 mass parts with respect to 100 mass parts of polyimides.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 2 to prepare 6% by mass of polyamic acid, 20% by mass of NMP, 59% by mass of GBL, and 15% by mass of BCS.
20 g of the reaction solution of polyimide and amine compound prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain the coating solution of the present invention. The solvent composition of this coating liquid is NMP / GBL / BCS = 16/66/12 in mass ratio.

(Synthesis Example 23)
30.03 g (0.1 mol) of TDA, 9.46 g (0.0875 mol) of DA1, 3.77 g (0.01 mol) of DA2, and 1.49 of (aminoethylaminomethyl) phenethyltrimethoxysilane (No. 37 amine compound) g (0.005 mol) was reacted in 254 g of NMP for 24 hours at room temperature to prepare a polyamic acid solution. 50 g of this polyamic acid solution was diluted to 5% by mass with NMP, 8.0 g of pyridine and 17.1 g of acetic anhydride were further added as an imidization catalyst, and the mixture was reacted at 40 ° C. for 3 hours. This solution was put into 0.6 L of methanol, and the resulting precipitate was separated by filtration and dried to obtain a white polyimide powder. The obtained imidized polymer soluble in the solvent had a number average molecular weight of 5,951 and a weight average molecular weight of 22,992. The imidation ratio was 81%.

{Example 66}
3 g of the polyimide powder obtained in Synthesis Example 23 was stirred and dissolved in 34.5 g of NMP at 50 ° C. for 20 hours. Thereafter, 12.5 g of NMP was added and diluted so that the polyimide concentration in the solution was 6% by mass.
NMP, GBL, and BCS were added to 40 g of the polyamic acid solution obtained in Synthesis Example 2 to prepare 6% by mass of polyamic acid, 59% by mass of NMP, 20% by mass of GBL, and 15% by mass of BCS.
20 g of the polyimide solution prepared above and 80 g of dilute solution of polyamic acid were mixed and stirred at room temperature for 20 hours to obtain a coating solution of the present invention. The solvent composition of this coating solution is NMP / GBL / BCS = 66/16/12 in mass ratio.

<Evaluation of moisture absorption stability>
Using the coating solutions prepared in Examples 28 to 66, the moisture absorption stability was evaluated in the same manner as described above. As a result, no aggregate was observed in these coating solutions even after 6 hours.
(Liquid crystal aligning agent)
The coating solutions prepared in Examples 1 to 66 and Comparative Examples 1 to 5 were pressure filtered through a membrane filter having a pore diameter of 1 μm to obtain a liquid crystal aligning agent.

<Evaluation of rubbing resistance>
A liquid crystal aligning agent is spin-coated on a glass substrate with an ITO electrode, dried on a hot plate at 80 ° C. for 5 minutes, and then baked in a hot air circulation oven at 230 ° C. for 30 minutes to form a coating film having a thickness of 100 nm. I let you. The coated surface was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film. The film surface of the liquid crystal alignment film was observed with a real-time scanning laser microscope 1LM21D (objective lens 10 times) manufactured by Lasertec Corporation (magnification magnification 340 times on the monitor).

  As a result, no scratches or peeling of the film was observed on the surfaces of the liquid crystal alignment films obtained using the liquid crystal alignment agents comprising the coating liquids of Examples 1 to 64 and Example 66. Although peeling of the film was not observed on the surface of the liquid crystal alignment film obtained using the liquid crystal aligning agent comprising the coating liquids of Comparative Examples 1 to 5, many fine scratches were observed. Moreover, although the peeling of the film was not seen on the surface of the liquid crystal alignment film obtained using the liquid crystal aligning agent comprising the coating liquid of Example 65, fine scratches were observed. In Example 65, since γ-butyrolactone was used as a solvent for reacting the solvent-soluble polyimide and the amine compound, the amine compound reacted with γ-butyrolactone and consumed, and the addition amount of 2 parts by mass is sufficient. This is probably because a large amount did not react with the solvent-soluble polyimide.

<Evaluation of printability>
With the liquid crystal aligning agent which consists of the coating liquid of Example 1 and Examples 30-32, the printability test by the flexographic printing method was done as follows.
Printer: Nissha Printing Co. Angstromer S-15
Printing plate: APR plate of 400 mesh Printing conditions: The nip width was 0.2 mm. The tact time was set to 30 seconds, and after printing on 6 glass substrates of 100 mm × 100 mm, printing was performed on 4 Cr film-formed glass substrates of the same size. Finally, the printed substrate was dried on a hot plate at 80 ° C. for 5 minutes and observed with a microscope with a magnification of 50 times.
As a result, the liquid crystal aligning agent composed of the coating liquids of Example 1 and Example 30 was superior in in-plane film thickness uniformity than the other two liquid crystal aligning agents.

(Creation of liquid crystal display elements and evaluation of electrical characteristics)
A liquid crystal aligning agent is spin-coated on a glass substrate with an ITO electrode, dried on a hot plate at 80 ° C. for 5 minutes, and then baked in a hot air circulation oven at 230 ° C. for 30 minutes to form a coating film having a thickness of 100 nm. I let you. The coated surface was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film.

Two substrates with this liquid crystal alignment film are prepared, and a 6 μm spacer is sprayed on the surface of one liquid crystal alignment film, and then a sealant is printed thereon. After laminating so that the facing rubbing direction was orthogonal, the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (Merck Japan Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.
When using the liquid crystal aligning agent which consists of the coating liquid of Examples 1-65 and Comparative Examples 1-5 and observing the liquid crystal cell produced as mentioned above under a polarizing microscope, a liquid crystal is uniform with all the liquid crystal cells. Oriented.

<Evaluation of voltage holding ratio>
The liquid crystal cell produced above was measured using a VHR-1 voltage holding ratio measuring device manufactured by Toyo Technica Co., Ltd. at a temperature of 90 ° C., voltage: ± 4 V, pulse width: 60 μs, flame period: 16.67 ms, The voltage holding ratio calculated how much the voltage of 4 V / 60 μs was maintained after 16.6 ms under the temperature of 90 ° C.
The results are shown below.

<Evaluation of easy removal of accumulated charge>
Among the liquid crystal cells, the liquid crystal cell of the liquid crystal aligning agent (liquid crystal display element of the present invention) composed of the coating liquid of Example 4 and the liquid crystal cell of the liquid crystal aligning agent composed of the coating liquid of Comparative Example 1 (Comparative liquid crystal display element) ) And compared the ease of stored charge removal as follows.
A DC voltage of 10 V was applied to the liquid crystal cell for 30 minutes and short-circuited for 1 second, and then the change in potential (accumulated charge) generated in the liquid crystal cell was measured using a 6254 type liquid crystal physical property evaluation apparatus manufactured by Toyo Corporation. As a result, the liquid crystal display element of the present invention had a smaller accumulated charge and a faster charge reduction than the comparative liquid crystal display element. A graph of this potential change is shown in FIG.

According to the coating liquid of the present invention, precipitation of the resin component due to moisture absorption is suppressed, stable printability can be obtained, and it can be suitably used as a liquid crystal aligning agent. In addition, the liquid crystal alignment film of the present invention can provide a liquid crystal display element of higher quality than before, and this liquid crystal display element can be suitably used for various display devices.

It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2006-195403 filed on July 18, 2006 is cited herein as the disclosure of the specification of the present invention. Incorporated.

Claims (14)

Component (A): a solvent obtained from at least one amine compound selected from the group consisting of tetracarboxylic dianhydride, diamine compound, the following amine compound (a), amine compound (b) and amine compound (c) A coating solution comprising a soluble imidized polymer and (B) component: polyamic acid.
Amine compound (a): an amine having in its molecule one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] Compound. Note that in the formulas [K3] and [K4], the bonding directions of —CH ₂ —NH— are opposite to each other.
Amine compound (b): An amine compound having at least two primary amino groups selected from the above formulas [K1] and [K2] in the molecule.
Amine compound (c): an amine having at least one primary amino group selected from formula [K1] and formula [K2] and at least one imino group selected from formula [K3] and formula [K4] in the molecule Compound.

  The component (A) is at least one selected from the side chain and molecular end of a solvent-soluble polyimide obtained from tetracarboxylic dianhydride and a diamine compound, and the amine compound (a) and the amine compound (b). The coating liquid according to claim 1, which is an imidized polymer soluble in a solvent obtained by bonding with a kind of amine compound.   Component (A) is a product obtained by reacting a solvent-soluble polyimide obtained from tetracarboxylic dianhydride and a diamine compound with at least one amine compound selected from the amine compound (a) and the amine compound (b). The coating solution according to claim 1, which is a product.   The component (A) is an imidized polymer soluble in a solvent obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a diamine compound containing an amine compound (c). The coating solution as described in 1. The component (A) is an imidized compound that is soluble in a solvent obtained by using at least one amine compound selected from amine compounds represented by the following formulas (i) and (ii) as the amine compound (a). The coating solution according to claim 1, which is a coalescence.

[Wherein R ¹ represents —CH ₂ —, —CH (CH ₃ ) —, or —CH (CH ₂ CH ₃ ) —, an alkylene, or an aliphatic ring, and X ¹ represents a single bond or It represents an aliphatic hydrocarbon having 1 to 20 carbon atoms, and the aliphatic hydrocarbon may contain —NH—. X ² represents an organic group having 1 to 20 carbon atoms, and an organic group comprising an alkyl group having 1 to 20 carbon atoms, a cyclic aliphatic group, an aromatic group, a heterocyclic group, a carboxyl group, and a combination thereof. And unsaturated bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), amino bond (—NH—), amine bond (—N—), silyl bond (—Si—), siloxane bond (—SiO—) and the like may be included. Further, the alkyl group of X ² may form a heterocyclic structure with any of —R ¹ —, —X ¹ —, —CH ₂ —, and —NH—. ] The component (A) is an imidized compound that is soluble in a solvent obtained by using at least one amine compound selected from amine compounds represented by the following formulas (iii) to (v) as the amine compound (b): The coating solution according to claim 1, which is a coalescence.

[In the formula, R ¹ represents —CH ₂ —, —CH (CH ₃ ) —, or —CH (CH ₂ CH ₃ ) —, an alkylene, or an aliphatic ring, and H ₂ N—R ¹ — as ^{R 1 -R} 1 -NH ₂ may be the same or different. X ³ represents a single bond or an organic group having 1 to 20 carbon atoms, an organic group consisting of alkylene having 1 to 20 carbon atoms, an aliphatic ring, an aromatic ring, a heterocyclic ring, and a combination thereof, and , Unsaturated bond, ether bond (—O—), ketone bond (—CO—), ester bond (—COO—), thioether bond (—S—), silyl bond (—Si—), siloxane bond (—SiO 2) -) Etc. may be included. X ⁴ , X ⁵ , X ⁶ , X ⁷ and X ⁸ each independently represent an aliphatic hydrocarbon having 1 to 20 carbon atoms, and may be the same or different. ] The component (A) is obtained using at least one amine compound selected from amine compounds represented by the following formulas (i), (ii), (iv) and (v) as the amine compound (c). The coating solution according to claim 1, which is an imidized polymer soluble in a solvent.

  The ratio of the imidized polymer of the component (A) and the polyamic acid of the component (B) is 20 to 99% by mass of the polyamic acid of the component (B) in the total mass of the component (A) and the component (B). The coating solution according to claim 1, 2, or 4 to 7.   The component (A) contains at least one amine compound selected from the amine compound (a) and the amine compound (b) with respect to 100 parts by mass of the solvent-soluble polyimide obtained from the tetracarboxylic dianhydride and the diamine compound. The coating liquid according to claim 3, which is a product obtained by reacting ˜15 parts by mass.   Component (A) is an imidized polymer soluble in a solvent obtained by imidizing a polyimide precursor obtained by reacting a tetracarboxylic dianhydride and a diamine containing the amine compound (c) represented above. The coating solution according to claim 4 or 7, wherein the amount of the amine compound (c) is 1 mol% to 15 mol% in the total amount of the diamine and the amine compound (c) combined.   The liquid crystal aligning agent which consists of a coating liquid in any one of Claims 1-10.   The liquid crystal aligning agent according to claim 11, wherein the amide-based solvent is contained in an amount of 50% by mass or more in the coating solution.   The liquid crystal aligning film obtained using the liquid crystal aligning agent of Claim 11 or 12.   A liquid crystal display element using the liquid crystal alignment film according to claim 13.

Images