WO2018047872A1

WO2018047872A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: WO2018047872A1
Application number: PCT/JP2017/032154
Authority: WO
Inventors: 幸司巴; 大輝山極
Original assignee: 日産化学工業株式会社
Priority date: 2016-09-07
Filing date: 2017-09-06
Publication date: 2018-03-15
Also published as: KR20190050811A; CN109952530A; TW201823306A; CN109952530B; JPWO2018047872A1; TWI801351B; KR102554992B1; JP7299556B2

Abstract

A liquid crystal alignment film that contains a polymer which has an aromatic heterocyclic ring, a primary amino group and a secondary amino group in the structure; and a liquid crystal aligning agent which is capable of forming this liquid crystal alignment film. It is preferable that the aromatic heterocyclic ring, the primary amino group and the secondary amino group are produced when the liquid crystal alignment film is fired; and the liquid crystal aligning agent specifically contains at least one polymer that is selected from among polyamic acids and polyimides that are imidized products of the polyamic acids, said polyamic acids being reaction products of a tetracarboxylic acid dianhydride and a diamine component that contains at least one diamine selected from among the component (A) and the component (B) described below and a diamine containing a skeleton of the component (C) described below. In the chemical formulae, the symbols are as defined in the description. Component (A): diamines having at least one structure selected from among a structure of formula (1-1) and a structure of formula (1-2) Component (B): diamines having a structure of formula (2) Component (C): diamines having at least one structure selected from among a structure of formula (a) and a structure of formula (b)

Description

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

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

The liquid crystal display element is known as a light, thin and low power display device. In recent years, high-definition liquid crystal display elements for mobile phones and tablet terminals, which have rapidly expanded their market share, have made remarkable developments that require high display quality. *

The liquid crystal display element is configured by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes. In the liquid crystal display element, an organic film made of an organic material is used as the liquid crystal alignment film so that the liquid crystal is in a desired alignment state between the substrates. That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, and is formed on a surface of the substrate that holds the liquid crystal in contact with the liquid crystal, and plays a role of aligning the liquid crystal in a certain direction between the substrates. *

In recent years, liquid crystal display elements have been used for mobile applications such as smartphones and mobile phones. In these applications, in order to secure as many display surfaces as possible, it is necessary to make the width of the sealing agent used for bonding the substrates of the liquid crystal display elements narrower than in the past. Furthermore, for the reasons described above, the position of the sealing agent is also required to be in the position in contact with the end of the liquid crystal alignment film having low adhesion to the sealing agent or on the liquid crystal alignment film. In such a case, particularly when used under high temperature and high humidity conditions, water is likely to be mixed between the sealing agent and the liquid crystal alignment film, and display unevenness occurs in the vicinity of the frame of the liquid crystal display element. *

In order to solve this problem, a liquid crystal aligning agent using an additive having a specific structure has been proposed (see Patent Document 1).

International Publication No. 2015/072554

However, in recent years, further improvement in adhesion between the liquid crystal alignment film and the sealant has been demanded. *

Among these, it is known that in improving the characteristics from the sealant, it is difficult to achieve both the adhesion property between the sealant and the liquid crystal alignment film and the moisture permeation prevention property of the sealant. There is a need to improve characteristics from *

Therefore, the present invention has an object to provide a liquid crystal aligning agent that can enhance the adhesion between the sealing agent and the liquid crystal alignment film and can suppress the occurrence of display unevenness near the frame of the liquid crystal display element under high temperature and high humidity conditions. And

As a result of intensive studies to solve the above problems, the present inventors have found a liquid crystal alignment film containing a polymer having a specific aromatic heterocycle, primary amino group, and secondary amino group in the structure. By using it, the present invention has been completed.

The first aspect of the present invention for achieving the above object is a liquid crystal alignment film characterized by containing a polymer having an aromatic heterocyclic ring and a primary amino group and a secondary amino group in the structure.

A second aspect of the present invention that achieves the above object is a film made of a fired product, in a structure in which the skeleton of the aromatic heterocyclic ring, the primary amino group, and the secondary amino group are generated by firing. The liquid crystal alignment film according to the first aspect is characterized in that it is contained.

The third aspect of the present invention that achieves the above object is the liquid crystal according to the first or second aspect, characterized in that the aromatic heterocycle is a pyridine skeleton, a benzimidazole skeleton, or an imidazole skeleton. Alignment film.

According to a fourth aspect of the present invention for achieving the above object, there is provided the liquid crystal alignment film according to the second aspect, wherein the fired product is produced at a firing temperature of 100 ° C. to 300 ° C.

A fifth aspect of the present invention for achieving the above object is a liquid crystal display element comprising the liquid crystal alignment film according to any one of the first to fourth aspects.

A sixth aspect of the present invention that achieves the above object is a liquid crystal aligning agent for obtaining a liquid crystal alignment film according to any one of the first to fourth aspects.

A seventh aspect of the present invention that achieves the above object is a diamine component comprising at least one diamine selected from the following component (A) and the following component (B) and a diamine containing a skeleton of the following component (C): And at least one polymer selected from polyamic acid that is a reaction product of tetracarboxylic dianhydride and polyimide that is an imidized product thereof. .
Component (A): a diamine having at least one structure selected from the following formula (1-1) and the following formula (1-2)

(Wherein D represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and D may have various substituents. , E is a single bond, or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (—O— ), An ester bond (—OCO—, —COO—), m is 1 or 0, R represents a thermal leaving group, and * represents a bond with another atom.)
Component (B): a diamine having the structure of the following formula (2)

(Wherein, _{X 1} is ^{^{-O -, - NQ 1 -,}} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one divalent element selected from the group consisting of -OCO- An organic group, Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and at least one divalent organic group selected from the group consisting of an aromatic hydrocarbon group, _{X 3} is a single bond or ^{^{-O -, - NQ 2 -,}} - CONQ 2 -, - NQ 2 CO- , —COO—, —OCO—, and —O (CH ₂ ) _m — (m is an integer of 1 to 5), and at least one divalent organic group selected from the group consisting of Q ² hydrogen atom or a carbon atoms is 3 alkyl group, X ₄ is an aromatic heterocycle, * the other It represents a bond with the child.)
Component (C): a diamine having at least one structure selected from the following formula (a) and the following formula (b)

(In the formula, X ¹ is an oxygen atom or a sulfur atom, A ¹ to A ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms is 1 to 9. * Represents a bond with another atom.)

By using the liquid crystal aligning agent of the present invention, the adhesion between the sealing agent and the liquid crystal aligning film is improved, and the occurrence of display unevenness near the frame of the liquid crystal display element can be suppressed under high temperature and high humidity conditions. Can be obtained. Therefore, the liquid crystal display element having a liquid crystal alignment film obtained by this can solve the display unevenness in the vicinity of the frame by enhancing the adhesion between the sealing agent and the liquid crystal alignment film, and can be suitably used for a large screen and high definition liquid crystal display. it can.

Each constituent requirement of the liquid crystal alignment film of the present invention will be described in detail below.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention contains a polymer having an aromatic heterocycle, a primary amino group and a secondary amino group in the structure.

The liquid crystal alignment film of the present invention is obtained by applying a liquid crystal aligning agent on a substrate and baking it to form a polymer film (hereinafter also referred to as a film) contained in the liquid crystal aligning agent, followed by rubbing treatment or light irradiation. It is produced by performing an orientation process. In the case of vertical alignment use, it can be used as a liquid crystal alignment film without alignment treatment. *

The substrate used at this time is not particularly limited as long as it is a highly transparent substrate. In addition to a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. From the viewpoint of simplification of the process, it is preferable to use a substrate on which an ITO electrode for driving a liquid crystal is formed. In the reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used if only one substrate is used, and a material that reflects light such as aluminum can be used as an electrode in this case. *

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

After coating the liquid crystal aligning agent on the substrate, the solvent is evaporated at 100 ° C. to 300 ° C., preferably 100 ° C. to 250 ° C., more preferably 150 ° C. to 250 ° C. by a heating means such as a hot plate. (Hereinafter, this step is also referred to as a firing step). *

In the calcination step, the thermal leaving group protecting the amino group in the polymer is removed by heat to generate highly reactive primary and secondary amino groups, some of which are heavy. By carrying out a cyclization reaction with other sites in the coalescence, an aromatic heterocycle is generated, and as a result, the liquid crystal alignment film of the present invention is obtained. From the viewpoint of the effects of the present invention and the storage stability of the liquid crystal alignment agent From the viewpoint of sex. *

The structure of an amino group to which a thermally leaving group is preferably contained, which is preferably contained in the polymer of the present invention, is expressed as follows, for example. *

In the above formula (a), X ¹ is an oxygen atom or a sulfur atom, A ¹ to A ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms is 1 to 9 It is. In the above formulas (a) and (b), * represents a bond with another atom.

Examples of structures that can generate an aromatic heterocycle by performing a cyclization reaction with a primary amino group include the following structures. *

In the formula, D represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring, and D may have various substituents. E is a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (—O -) Represents an ester bond (-OCO-, -COO-). m is 1 or 0. R is a structure represented by the above formula (a). *

If the thickness of the coating film after the baking step 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 that it is preferably 5 nm to 300 nm, more preferably 10 nm to 100 nm. When the liquid crystal is aligned horizontally or tilted, the fired film is subjected to alignment treatment by a known method such as rubbing or irradiation with polarized ultraviolet rays.

<Aromatic heterocycle>
Examples of the aromatic heterocyclic ring contained in the polymer in the liquid crystal alignment film of the present invention include pyrrole ring, furan ring, thiophene ring, imidazole ring, pyrazole ring, oxazole ring, isoxazole ring, thiazole ring. 5-membered aromatic heterocycles such as isothiazole ring; 6-membered aromatic heterocycles such as pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring; quinoline, isoquinoline, coumarin, indole, benzimidazole, benzofuran And other polycyclic aromatic heterocyclic compounds.

Among these, from the viewpoint of more prominently achieving the effects of the present invention, a pyridine ring, an imidazole ring, and a benzimidazole ring are preferable, and an imidazole ring and a benzimidazole ring are particularly preferable. *

Even if the aromatic heterocyclic ring is already present in the polymer contained in the liquid crystal aligning agent, the effect of the present invention can be obtained. From the viewpoint described above, the aromatic heterocyclic skeleton is formed during the firing of the liquid crystal aligning film. Is preferably formed. In addition, the aromatic heterocyclic ring which already exists in the polymer contained in the liquid crystal aligning agent and the aromatic heterocyclic ring formed at the time of baking may coexist.

<Polymer>
The polymer contained in the liquid crystal aligning agent of the present invention and the liquid crystal alignment film obtained using the same is not particularly limited as long as it has an aromatic heterocyclic ring and a primary amino group and a secondary amino group in the structure. However, from the viewpoint of the characteristics and reliability of the obtained liquid crystal display element, it is at least one polymer selected from a polyimide precursor which is a reaction product of a diamine component and a tetracarboxylic derivative component and a polyimide which is an imidized product thereof. Preferably there is.

The polyimide precursor here refers to a polyamic acid or a polyamic acid ester.

<Diamine>
The polymer contained in the liquid crystal alignment agent of the present invention and the liquid crystal alignment film obtained using the same is preferably at least one polymer selected from a polyimide precursor and a polyimide which is an imidized product thereof. In the diamine component used in the production, a diamine having a structure that generates an aromatic heterocycle (hereinafter also referred to as a specific diamine 1) and a diamine having an aromatic heterocycle in the structure (hereinafter also referred to as a specific diamine 2) ) And at least one diamine selected from the group consisting of a diamine having a structure that generates a primary amino group or a secondary amino group (hereinafter also referred to as a specific diamine 3).

Each diamine will be described in detail below.

<Specific diamine 1>
The specific diamine 1 has a structure selected from the following formulas (1-1) and (1-2).

In the above formula (1-1), D represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and D has various substituents. You may do it. In the above formula (1-2), E represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F Represents a single bond, an ether bond (—O—) or an ester bond (—OCO—, —COO—). In the above formula (1-1), m is 1 or 0. In the above formula (1-1) and the above formula (1-2), R represents a thermal leaving group. *

* In the above formula (1-1) and the above formula (1-2) represents a bond with another atom. In the case of bonding to an amino group, the substitution position of the amino group is not particularly limited, but from the viewpoint of synthesis difficulty and availability of reagents, the position of meta or para is preferable based on the amide bond, and the viewpoint of liquid crystal orientation Then, the position of para is particularly preferable. Further, even in aminobenzene having no amino group protected by a thermal leaving group, the position of meta or para is preferable when based on the amide bond, and the position of meta is preferable from the viewpoint of solubility, From the viewpoint of liquid crystal orientation, the position of para is preferable. In addition, hydrogen of aminobenzene having no —NHR may be substituted with an organic group or a halogen atom such as fluorine. *

Further, * in the above formula (1-1) may be bonded to the same structure of the above formula (1-1) or the structure of the above formula (1-2). It may be combined with the structure of the formula (1-1) or the structure of the above formula (1-2). *

D in the above formula (1-1) and E in the above formula (1-2) are the same as defined above, but the details thereof are not particularly limited, and dicarboxylic acid or tetracarboxylic acid diester used as a raw material. Various structures can be selected depending on the structure of the anhydride or the like. D is preferably a divalent hydrocarbon group from the viewpoint of solubility, and preferred examples include a linear alkylene group and a cyclic alkylene group, and this hydrocarbon group may have an unsaturated bond. . Further, from the viewpoint of liquid crystal orientation and electrical characteristics, a divalent aromatic hydrocarbon group, a heterocyclic ring, and the like are preferable. From the viewpoint of liquid crystal orientation, it is preferable that D has no substituent, but from the viewpoint of solubility, it is preferable that D be substituted with a carboxylic acid group or a fluorine atom.

<Specific diamine 2>
The specific diamine 2 has the structure of the following formula (2).

In the formula (2), _{X 1} is ^{^{-O -, - NQ 1 -,}} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one selected from the group consisting of -OCO- A divalent organic group, Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a non-aromatic cyclic carbonization hydrogen radicals, and at least one divalent organic group selected from the group consisting of an aromatic hydrocarbon group, _{X 3} is a single bond or ^{-O -, - NQ 2 -,} - CONQ 2 -, - NQ ² at least one divalent organic group selected from the group consisting of ₂ CO—, —COO—, —OCO—, and —O (CH ₂ ) _m — (m is an integer of 1 to 5); Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X ₄ is an aromatic heterocyclic ring.

* Represents a bond with another atom. In the case of bonding to an amino group, the bonding position of the two amino groups (—NH ₂ ) is not limited. Specifically, with respect to the linking group (X ₁ ) of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring Position, 3, 5 positions. Among these, taking into consideration the reactivity when synthesizing the polyamic acid and the ease of synthesizing the diamine compound, the bonding positions of the two amino groups are positions 2, 4 and 2, 5; The positions 3, 5 are particularly preferred.

Further, * may be bonded to the same structure of the above formula (2), or may be bonded to the structure of the above formula (2) through another atom. *

X ₁ is ^{^{-O -, - NQ 1 -,}} - CONQ 1 -, - NQ 1 CO -, - is _CH 2 O-, and at least one divalent organic group selected from the group consisting of -OCO- . Among ^{them, -O -, - NQ 1 -} , - CONQ 1 -, - NQ 1 CO- is preferred. Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom or a methyl group.

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

The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear or branched. Moreover, you may have an unsaturated bond. An aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferred. *

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

X ₄ is an aromatic heterocycle. Examples and preferred structures thereof are the same as those described above.

Particularly preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n are as shown in Tables 1 to 3 below. Q ¹ and Q ² are as defined above.

<Specific diamine 3>
The specific diamine 3 is a diamine having a structure that generates a primary amino group or a secondary amino group, and has a structure of an amino group protected by a thermal leaving group in the structure. Such a structure is not particularly limited, but it is preferable to contain at least one structure selected from the following structures from the viewpoint of easiness of thermal desorption.

In the above formula (a), X ¹ is an oxygen atom or a sulfur atom, A ¹ to A ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms is 1 to 9 It is. In the formula (a) and the formula (b), * represents a bond with another atom.

In the above formula (a), X ¹ represents an oxygen atom or a sulfur atom, an oxygen atom is preferable. A ¹ to A ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, preferably 1 carbon atom. The total number of carbon atoms is 1 to 9, preferably 3 to 6. In the formula (a) and the formula (b), * represents a bond with another atom.

Examples of the diamine having at least one structure selected from the above formula (a) and the above formula (b) in the structure include the following diamines. In the formula, “Boc” is a tert-butoxycarbonyl group. *

<Diamine having amino group not involved in polymerization>
In the production of the liquid crystal aligning agent for obtaining the liquid crystal alignment film of the present invention, a diamine having a structure that generates a primary amino group or a secondary amino group, that is, a structure of an amino group protected by a thermal leaving group is used. A diamine having an amino group that is not protected and does not participate in polymerization may be used. Such diamines are exemplified below.

<Other diamines>
In producing a polyimide precursor preferably used as a polymer contained in the liquid crystal aligning agent of the present invention, a diamine other than the specific diamine (hereinafter also referred to as other diamine) is contained within the limit that exhibits the effects of the present invention. You may do it. Such a diamine is represented by the following general formula (3).

In the above formula (3), Y is a divalent organic group derived from diamine, and its structure is not particularly limited. Specific examples of the structure of Y include the following formulas (Y-1) to (Y-99). *

In the above formula (Y-90), m and n are each an integer of 1 to 11, m + n is an integer of 2 to 12, and in the above formula (Y-95), h is an integer of 1 to 3. In the formula (Y-92) and the formula (Y-98), j is an integer of 0 to 3.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride used in producing a polyimide precursor preferably used as a polymer contained in the liquid crystal aligning agent of the present invention is represented by the following formula (4).

In the above formula (4), X is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. Two or more kinds of X may be mixed in the polyimide precursor. Specific examples of X include structures of the following formula (X-1) to the following formula (X-44). *

Moreover, when manufacturing polyamic acid ester, it can manufacture using dicarboxylic acid diester corresponding to the various structures of the tetracarboxylic dianhydride mentioned here. *

R ₁ to R ₄ in the above formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group, or phenyl It is a group. When R ₁ to R ₄ have a bulky structure, the liquid crystal orientation may be lowered, so a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable.

In the above formula (4), X preferably contains a structure selected from the above formulas (X-1) to (X-14) from the viewpoint of availability of monomers. *

Since the reliability of the obtained liquid crystal alignment film can be further improved, the structure of X is an aliphatic group such as the above formula (X-1) to the above formula (X-7) and the above formula (X-10). The structure consisting only of these is preferable, and the structure represented by the above formula (X-1) is more preferable. Furthermore, in order to show good liquid crystal alignment, the structure of X is more preferably the following formula (X1-1) or the following formula (X1-2). *

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention has the form of the solution in which the above-mentioned polyimide precursor or its imidized polymer (henceforth a polymer of a specific structure) was melt | dissolved in the organic solvent. The molecular weight of the polymer having a specific structure is preferably 2,000 to 500,000 in terms of weight average molecular weight, more preferably 5,000 to 300,000, and still more preferably 8,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 4,000 to 50,000.

The concentration of the polymer of the liquid crystal aligning agent used in the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but it is 1 weight from the viewpoint of forming a uniform and defect-free coating film. % From the viewpoint of storage stability of the solution, and preferably 10% by weight or less. A particularly preferred polymer concentration is 2 to 8% by mass. *

The organic solvent contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as the polymer having a specific structure is uniformly dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, Examples include 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like. You may use these 1 type or in mixture of 2 or more types. Moreover, even if it is a solvent which cannot melt | dissolve a polymer uniformly independently, if it is a range which a polymer does not precipitate, you may mix with said organic solvent. Of these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is preferably used. *

Moreover, the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the coating properties and the surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-described solvents. Such a mixed solvent is also preferably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent to be used in combination are given below, but the organic solvent is not limited to these examples. *

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6- Zimechi -4-heptanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3 -Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl Ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxy Butyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, Ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, Propylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, di Propylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether Ruacetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, Ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methylethyl 3-ethoxypropionate, 3-methoxypropionic acid Ethyl, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate Lactate ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, lactic acid isoamyl ester, and the like solvents represented by the following formula [D-1] ~ following formula [D-3]. *

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

Among these, preferred solvent combinations include N-methyl-2-pyrrolidone, γ-butyrolactone, ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and N-ethyl-2-pyrrolidone. And propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether And diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, 2,6-dimethyl-4-heptanol, N-methyl-2-pi Examples include loridone, γ-butyrolactone, and dipropylene glycol dimethyl ether. The kind and content of such a solvent are appropriately selected according to the application device, application conditions, application environment, and the like of the liquid crystal aligning agent. *

In the liquid crystal aligning agent of the present invention, in addition to the above, as long as the effects of the present invention are not impaired, a polymer other than the polymer described in the present invention, the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, etc. Dielectric or conductive material for changing characteristics, silane coupling agent for improving adhesion between liquid crystal alignment film and substrate, crosslinkability for increasing hardness and density of liquid crystal alignment film When firing the compound, and further, the coating film, an imidization accelerator for the purpose of efficiently proceeding imidization by heating of the polyimide precursor may be added. *

In addition, in order to improve the adhesion of the coating film to the substrate, an additive such as a silane coupling agent may be added to the liquid crystal aligning agent of the present invention, and other resin components may be added. . *

Examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include a functional silane-containing compound and an epoxy group-containing compound, such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- Glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2- Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl- 3-aminopropyltri Toxisilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10 -Triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-amino Propyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3 -Aminopropyltrime Xylsilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neo Pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane or N, N, N ′, N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like. *

In addition, the following additives may be added to the liquid crystal aligning agent of the present invention in order to increase the mechanical strength of the film. *

These additives are preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 parts by mass, the effect cannot be expected. If the amount exceeds 30 parts by mass, the orientation of the liquid crystal is lowered, and therefore the amount is more preferably 0.5 to 20 parts by mass. *

<Liquid crystal display element>
The liquid crystal display element of the present invention is a liquid crystal display element obtained by a known method after obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the above-described method and performing alignment treatment by rubbing treatment or the like. is there.

The method for producing a liquid crystal cell of a liquid crystal display element is not particularly limited. For example, a pair of substrates on which a liquid crystal alignment film is formed is preferably 1 μm to 30 μm, more preferably 1 μm to 30 μm, with the liquid crystal alignment film surface inside. In general, a method is used in which a spacer of 2 μm to 10 μm is placed and a periphery is fixed with a sealant, and liquid crystal is injected and sealed. The method for enclosing the liquid crystal is not particularly limited, and examples thereof include a vacuum method of injecting liquid crystal after reducing the pressure inside the produced liquid crystal cell, and a dropping method of sealing after dropping the liquid crystal. Since the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention as described above has excellent characteristics, liquid crystal display elements such as VA, TN, STN, TFT, and lateral electric field type, It can be used as a liquid crystal alignment film for ferroelectric and antiferroelectric liquid crystal display elements. *

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and the like, but the present invention is not limited to these examples. In addition, the symbol of a compound and a solvent is as follows.
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: Butyl cellosolve DA-1: Structural formula (DA-1)
DA-2: Structural formula below (DA-2)
DA-3: Structural formula below (DA-3)
DA-4: Structural formula below (DA-4)
DA-5: Structural formula below (DA-5)
DA-6: Structural formula below (DA-6)
DA-7: Structural formula below (DA-7)
DA-8: Structural formula below (DA-8)
DA-9: Structural formula below (DA-9)
DA-10: Structural formula below (DA-10)
CA-1: Structural formula below (CA-1)
CA-2: Structural formula below (CA-2)
CA-3: Structural formula shown below (CA-3)
CA-4: Structural formula below (CA-4)

<Viscosity>
In the synthesis example, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL, cone rotor TE-1 (1 ° 34 ′, R24), temperature 25 Measured at ° C.

<Measurement of imidation ratio of polyimide>
The imidation ratio of polyimide in the synthesis example was measured as follows. 30 mg of polyimide powder was put into an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05 mass% TMS (tetramethylsilane)) (Mixed product) (0.53 ml) was added and completely dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) (manufactured by JEOL Datum). The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 ppm to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value.

Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

(Example 1)
In a 1 L four-necked flask equipped with a stirrer and a nitrogen introduction tube, DA-1 was 86.0 g (352 mmol), DA-2 was 53.4 g (95.9 mmol), and DA-3 was 76.5 g (191 mmol). Weighed out and added 1580 g of NMP and dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 93.2 g (416 mmol) of CA-1 was added, and 168 g of NMP was further added, followed by stirring at 40 ° C. for 3 hours under a nitrogen atmosphere. Further, 28.2 g (143 mmol) of CA-2 was added, 160 g of NMP was further added, and the mixture was stirred at 23 ° C. for 4 hours in a nitrogen atmosphere to obtain a polyamic acid solution (PAA-1). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 200 mPa · s.

In a 200 mL Erlenmeyer flask containing a stir bar, 30.7 g of this polyamic acid solution (PAA-1) was taken, 9.07 g of NMP, 26.2 g of GBL, and 3-glycidoxypropyltriethoxysilane. 3.93 g of NMP solution containing 1% by mass and 17.4 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyamic acid solution (A-1).

(Example 2)
To a 3 L Erlenmeyer flask containing a stir bar, 800 g of the polyamic acid solution (PAA-1) obtained in Example 1 was collected, 700 g of NMP, 69.7 g of acetic anhydride, and 18.0 g of pyridine were added. The mixture was stirred at room temperature for 30 minutes and then reacted at 55 ° C. for 3 hours. This reaction solution was put into 5600 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 75%.

In a 300 mL Erlenmeyer flask containing a stirring bar, 20.4 g of this polyimide powder was taken, 115 g of NMP was added, and the mixture was dissolved by stirring at 50 ° C. for 20 hours. Further, 16.3 g of this solution was taken into a 100 mL Erlenmeyer flask containing a stirring bar, and an NMP solution containing 5.49 g of NMP, 14.3 g of GBL, and 1% by mass of 3-glycidoxypropyltriethoxysilane was obtained. 2.15 g and 9.56 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyimide solution (A-2).

(Synthesis Example 1)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen introducing tube, 2.20 g (9.00 mmol) of DA-1, 2.04 g (5.97 mmol) of DA-4, and 1.62 g of DA-5 ( 15.0 mmol), 59.3 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring the diamine solution under water cooling, 6.32 g (28.1 mmol) of CA-1 was added, 30.0 g of NMP was further added, and the mixture was stirred at 40 ° C. for 3 hours under a nitrogen atmosphere to obtain a polyamic acid solution ( PAA-2) was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 220 mPa · s.

In a 200 mL Erlenmeyer flask containing a stir bar, 21.1 g of this polyamic acid solution (PAA-2) was collected, 2.20 g of NMP, 15.3 g of GBL, and 3-glycidoxypropyltriethoxysilane. 2.30 g of NMP solution containing 1% by mass and 10.2 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to obtain a polyamic acid solution (B-1).

(Synthesis Example 2)
In a 500 mL Erlenmeyer flask containing a stir bar, 90.0 g of the polyamic acid solution (PAA-2) obtained in Synthesis Example 1 was collected, 45.0 g of NMP, 8.14 g of acetic anhydride, and 2 of pyridine. .10 g was added and stirred at room temperature for 30 minutes, followed by reaction at 55 ° C. for 3 hours. This reaction solution was put into 600 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 67%.

In a 300 mL Erlenmeyer flask containing a stirring bar, 5.50 g of this polyimide powder was taken, 40.3 g of NMP was added, and the mixture was dissolved by stirring at 50 ° C. for 20 hours. Further, 25.0 g of this solution was taken into a 200 mL Erlenmeyer flask containing a stirring bar, and an NMP solution containing 5.30 g of NMP, 20.0 g of GBL, and 1% by mass of 3-glycidoxypropyltriethoxysilane was obtained. 3.00 g and 13.3 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyimide solution (B-2).

(Synthesis Example 3)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, DA-5 (0.540 g, 4.99 mmol), DA-6, 2.12 g (8.75 mmol), and DA-7, 0.826 g ( 2.50 mmol), 3.80 g (8.75 mmol) of DA-8 was weighed, 41.3 g of NMP was added, and dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 3.12 g (12.4 mmol) of CA-3 was added, and 17.8 g of NMP was further added, followed by stirring at 60 ° C. for 3 hours in a nitrogen atmosphere. Further, 2.42 g (12.3 mmol) of CA-2 was added, and 14.1 g of NMP was further added, followed by stirring at 40 ° C. for 4 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 115 mPa · s.

In a 200 mL Erlenmeyer flask containing a stir bar, 20.6 g of this polyamic acid solution was taken, 10.6 g of NMP, 20.6 g of GBL, and NMP containing 1% by mass of 3-glycidoxypropyltriethoxysilane. 3.09 g of the solution and 13.7 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to obtain a polyamic acid solution (B-3).

(Synthesis Example 4)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 3.18 g (8.00 mmol) of DA-3, 2.38 g (6.00 mmol) of DA-9, 1.79 g of DA-10 ( 6.00 mmol), 66.2 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 4.25 g (19.5 mmol) of CA-4 was added, 18.9 g of NMP was further added, and the mixture was stirred at 50 ° C. for 15 hours under a nitrogen atmosphere, and a polyamic acid solution was added. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 264 mPa · s.

In a 100 mL Erlenmeyer flask containing a stir bar, 15.3 g of this polyamic acid solution was taken, NMP 0.300 g, GBL 10.3 g, and NMP containing 1% by mass of 3-glycidoxypropyltriethoxysilane. 1.54 g of the solution and 6.86 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyamic acid solution (B-4).

(Example 3)
In a 50 mL Erlenmeyer flask containing a stir bar, 5.42 g of the polyamic acid solution (A-1) obtained in Example 1 and 5.41 g of the polyamic acid solution (B-1) obtained in Synthesis Example 1 were obtained. Weighed out and stirred for 2 hours with a magnetic stirrer to obtain a liquid crystal aligning agent (A-3).

Example 4
In a 50 mL Erlenmeyer flask containing a stir bar, 5.55 g of the polyimide solution (A-2) obtained in Example 2 and 5.51 g of the polyimide solution (B-2) obtained in Synthesis Example 2 were weighed. Then, the mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-4).

(Example 5)
In a 50 mL Erlenmeyer flask containing a stir bar, 5.42 g of the polyamic acid solution (B-1) obtained in Synthesis Example 1 and 5.42 g of the polyamic acid solution (B-3) obtained in Synthesis Example 3 were used. Weighed out and stirred for 2 hours with a magnetic stirrer to obtain a liquid crystal aligning agent (A-5).

(Example 6)
In a 50 mL Erlenmeyer flask containing a stir bar, 5.62 g of the polyamic acid solution (A-1) obtained in Example 1 and 5.52 g of the polyamic acid solution (B-4) obtained in Synthesis Example 4 were obtained. Weighed out and stirred for 2 hours with a magnetic stirrer to obtain a liquid crystal aligning agent (A-6).

<Evaluation of seal adhesion>
The liquid crystal aligning agents obtained in Examples and Synthesis Examples were filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried on an 80 ° C. hot plate for 2 minutes, and then 20 ° C. at 230 ° C. A film having a thickness of 100 nm was obtained by baking for a minute. Two substrates thus obtained were prepared, 4 μm bead spacers were sprayed on the surface of the liquid crystal alignment film of one substrate, and then a sealing agent (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was dropped. Next, bonding was performed so that the liquid crystal alignment film surface of the other substrate was inside, and the overlapping width of the substrates was 1 cm. At that time, the amount of the sealant dropped was adjusted so that the diameter of the sealant after bonding was about 3 mm. The two bonded substrates were fixed with a clip and then thermally cured at 120 ° C. for 1 hour to prepare a sample for evaluating adhesiveness.

Next, after fixing the edge of the upper and lower substrates with the tabletop precision universal testing machine AGS-X 500N manufactured by Shimadzu Corporation, the prepared sample was pushed from the top of the center of the substrate, and the force when peeling (N) was evaluated as the sealing adhesive strength.

(Examples 7 to 12)
The liquid crystal aligning agents (A-1) to (A-6) obtained in Examples 1 to 6 were each filtered through a 1.0 μm filter, and samples for adhesion evaluation were prepared and sealed as described above. The results of evaluating the adhesive strength are shown in Table 4.

(Comparative Examples 1 to 4)
After the liquid crystal aligning agents (B-1) to (B-4) obtained in Synthesis Examples 1 to 4 were filtered through a 1.0 μm filter, samples for adhesion evaluation were prepared and sealed as described above. The results of evaluating the adhesive strength are shown in Table 4.

When the liquid crystal aligning agent described in the examples was used, the sealing adhesive strength was high and good.

(Example 13)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen introducing tube, 4.30 g (17.6 mmol) of DA-1, 2.67 g (4.80 mmol) of DA-2, and 3.27 g of DA-4 ( 9.57 mmol) was weighed, 75.1 g of NMP was added, and dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 4.66 g (20.7 mmol) of CA-1 was added, 9.34 g of NMP was further added, and the mixture was stirred at 40 ° C. for 3 hours under a nitrogen atmosphere. Further, 1.78 g (9.08 mmol) of CA-2 was added, and 8.00 g of NMP was further added, followed by stirring at 23 ° C. for 4 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 304 mPa · s.

In a 500 mL Erlenmeyer flask containing a stir bar, 90.0 g of this polyamic acid solution was taken, 79.0 g of NMP, 7.92 g of acetic anhydride, and 2.04 g of pyridine were added, followed by stirring at room temperature for 30 minutes. , Reacted at 55 ° C. for 3 hours. This reaction solution was put into 700 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 70%. *

In a 200 mL Erlenmeyer flask containing a stirring bar, 6.07 g of this polyimide powder was taken, 44.5 g of NMP was added, and the mixture was dissolved by stirring at 50 ° C. for 20 hours. Further, 20.3 g of this solution was taken into a 200 mL Erlenmeyer flask containing a stir bar, and an NMP solution containing 4.37 g of NMP, 16.2 g of GBL and 1% by mass of 3-glycidoxypropyltriethoxysilane was obtained. 2.43 g and 10.8 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyimide solution (A-7).

(Example 14)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, DA-1 (4.30 g, 17.6 mmol), DA-2 (2.67 g, 4.80 mmol), and DA-3, 1.91 g ( 4.80 mmol) and 1.64 g (4.80 mmol) of DA-4 were weighed out, 77.1 g of NMP was added, and dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 4.66 g (20.7 mmol) of CA-1 was added, and 8.88 g of NMP was further added, followed by stirring at 40 ° C. for 3 hours under a nitrogen atmosphere. Further, 1.71 g (8.69 mmol) of CA-2 was added, 8.00 g of NMP was further added, and the mixture was stirred at 23 ° C. for 4 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 312 mPa · s.

In a 500 mL Erlenmeyer flask containing a stir bar, 90.0 g of this polyamic acid solution was taken, 79.0 g of NMP, 7.02 g of acetic anhydride and 1.81 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes. , Reacted at 55 ° C. for 3 hours. This reaction solution was put into 700 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 71%. *

In a 200 mL Erlenmeyer flask containing a stirring bar, 6.03 g of this polyimide powder was taken, 44.2 g of NMP was added, and the mixture was dissolved by stirring at 50 ° C. for 20 hours. Further, 21.0 g of a 200 mL Erlenmeyer flask containing a stirring bar was taken from this solution, and 2 NMP solutions containing 4.48 g of NMP, 16.8 g of GBL and 1% by mass of 3-glycidoxypropyltriethoxysilane were obtained. .52 g and 11.2 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyimide solution (A-8).

(Synthesis Example 5)
DA-1 (4.30 g, 17.6 mmol) and DA-3 (5.73 g, 14.3 mmol) were weighed into a 1 L four-necked flask equipped with a stirrer and a nitrogen introduction tube, and NMP (73.6 g) was added. The solution was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 4.66 g (20.7 mmol) of CA-1 was added, 9.69 g of NMP was further added, and the mixture was stirred at 40 ° C. for 3 hours under a nitrogen atmosphere. Further, 1.50 g (7.65 mmol) of CA-2 was added, 8.53 g of NMP was further added, and the mixture was stirred at 23 ° C. for 4 hours under a nitrogen atmosphere to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 290 mPa · s.

Into a 500 mL Erlenmeyer flask containing a stir bar, 90.0 g of this polyamic acid solution was taken, 79.0 g of NMP, 8.16 g of acetic anhydride and 2.10 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes. , Reacted at 55 ° C. for 3 hours. This reaction solution was put into 700 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 72%. *

In a 200 mL Erlenmeyer flask containing a stirring bar, 6.10 g of this polyimide powder was taken, 44.7 g of NMP was added, and the mixture was dissolved by stirring at 50 ° C. for 20 hours. Further, 25.0 g of this solution was taken into a 200 mL Erlenmeyer flask containing a stirring bar, and an NMP solution containing 4.90 g of NMP, 19.8 g of GBL, and 1% by mass of 3-glycidoxypropyltriethoxysilane was obtained. 3.00 g and 13.3 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain a polyimide solution (B-5).

<Evaluation of liquid crystal alignment>
A method for manufacturing a liquid crystal cell for evaluating the liquid crystal alignment will be described below.

A liquid crystal cell having a configuration of an FFS liquid crystal display element is manufactured. First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an IZO electrode constituting the counter electrode as the first layer is formed on the entire surface. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by the CVD method is formed as the second layer. The film thickness of the second SiN film is 100 nm and functions as an interlayer insulating film. A comb-like pixel electrode formed by patterning an IZO film is arranged as a third layer on the second layer SiN film to form two pixels, a first pixel and a second pixel. is doing. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film. *

The pixel electrode of the third layer has a comb-like shape configured by arranging a plurality of electrode elements having a bow shape with a bent central portion. The width in the short direction of each electrode element is 3 μm, and the distance between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is configured by arranging a plurality of bent-shaped electrode elements having a bent central portion, the shape of each pixel is not a rectangular shape, and the central portion is similar to the electrode element. It has a shape similar to that of a bold, bent, bent at Each pixel is divided into upper and lower portions with a central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side. *

When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film to be described later is used as a reference, in the first region of the pixel, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise), and in the second region of the pixel The electrode elements of the pixel electrode are formed at an angle of −10 ° (clockwise). That is, in the first region and the second region of each pixel, the direction of the rotation operation (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode in the substrate plane is It is comprised so that it may become a mutually reverse direction. *

Next, the liquid crystal aligning agents obtained in Examples and Synthesis Examples were filtered through a 1.0 μm filter, and then applied to the prepared substrate with electrodes by spin coating. After drying on an 80 ° C. hot plate for 2 minutes, baking was performed in a hot air circulation oven at 230 ° C. for 20 minutes to obtain a polyimide film having a thickness of 60 nm. This polyimide film is rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 500 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm, rubbing direction: inclined by 10 ° with respect to the third layer IZO comb-teeth electrode Then, ultrasonic cleaning was performed for 1 minute in pure water for cleaning, and water droplets were removed by air blow. Then, it dried for 15 minutes at 80 degreeC, and obtained the board | substrate with a liquid crystal aligning film. Also, as a counter substrate, a polyimide film is formed on a glass substrate having an ITO electrode on the back surface and having a columnar spacer with a height of 4 μm in the same manner as described above. A substrate with a liquid crystal alignment film was obtained. One set of these two substrates with a liquid crystal alignment film is printed, and the sealant is printed on the substrate leaving the liquid crystal injection port. The other substrate has the liquid crystal alignment film surface facing and the rubbing direction is antiparallel. They were pasted together. Thereafter, the sealing agent was cured to produce an empty cell having a cell gap of 4 μm. Liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 120 ° C. for 1 hour and allowed to stand at 23 ° C. overnight, and then used for evaluation of liquid crystal alignment. *

Using this liquid crystal cell, an alternating voltage of 9 VPP was applied for 190 hours at a frequency of 30 Hz in a constant temperature environment of 60 ° C. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left as it was at room temperature for one day. *

After leaving, the liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal, and the backlight is turned on with no voltage applied so that the brightness of the transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel became darkest to the angle at which the first region became darkest was calculated as an angle Δ. Similarly, for the second pixel, the second area was compared with the first area, and a similar angle Δ was calculated. Then, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. That is, the smaller the angle, the better the liquid crystal alignment.

(Examples 15 to 18)
After the liquid crystal aligning agents (A-2), (A-4), (A-7) and (A-8) obtained in Examples 2, 4, 13, and 14 were each filtered through a 1.0 μm filter. Table 5 shows the results of producing a sample for evaluating adhesiveness as described above and evaluating the sealing adhesive force, and the result of the angle Δ of the liquid crystal cell.

(Comparative Example 5)
The liquid crystal aligning agent (B-5) obtained in Synthesis Example 5 was filtered through a 1.0 μm filter, a sample for evaluating adhesiveness was prepared as described above, and the results of evaluating the sealing adhesive force and the liquid crystal The results of cell angle Δ are shown in Table 5.

When the liquid crystal aligning agent described in the examples was used, the sealing adhesive strength was high, the angle Δ of the liquid crystal cell after aging was small, and the liquid crystal alignment was good.

The liquid crystal aligning agent of the present invention can solve the display unevenness in the vicinity of the frame by enhancing the adhesiveness between the sealing agent and the liquid crystal aligning film in a narrow frame liquid crystal display element capable of securing a large number of display surfaces. Useful.

Claims

A liquid crystal alignment film comprising a polymer having an aromatic heterocyclic ring and a primary amino group and a secondary amino group in the structure.
2. The film according to claim 1, wherein the film is a fired product, and the skeleton of the aromatic heterocyclic ring, the primary amino group, and the secondary amino group are contained in a structure generated by firing. Liquid crystal alignment film.
3. The liquid crystal alignment film according to claim 1, wherein the aromatic heterocyclic ring is a pyridine skeleton, a benzimidazole skeleton, or an imidazole skeleton.
3. The liquid crystal alignment film according to claim 2, wherein the fired product is produced at a firing temperature of 100 ° C. to 300 ° C.
A liquid crystal display element comprising the liquid crystal alignment film according to any one of claims 1 to 4.
A liquid crystal aligning agent for obtaining the liquid crystal aligning film according to any one of claims 1 to 4.
It is a reaction product of at least one diamine selected from the following component (A) and the following component (B) and a diamine component containing a diamine containing the skeleton of the following component (C) with tetracarboxylic dianhydride. The liquid crystal aligning agent according to claim 6, comprising at least one polymer selected from polyamic acid and polyimide which is an imidized product thereof.
Component (A): a diamine having at least one structure selected from the following formula (1-1) and the following formula (1-2)

(Wherein D represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and D may have various substituents. , E is a single bond, or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (—O— ), An ester bond (—OCO—, —COO—), m is 1 or 0, R represents a thermal leaving group, and * represents a bond with another atom.)
Component (B): a diamine having the structure of the following formula (2)

(Wherein, X 1 is -O -, - NQ 1 -, - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one divalent element selected from the group consisting of -OCO- An organic group, Q 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X 2 is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and at least one divalent organic group selected from the group consisting of an aromatic hydrocarbon group, X 3 is a single bond or -O -, - NQ 2 -, - CONQ 2 -, - NQ 2 CO- , —COO—, —OCO—, and —O (CH 2 ) m — (m is an integer of 1 to 5), and at least one divalent organic group selected from the group consisting of Q 2 hydrogen atom or a carbon atoms is 3 alkyl group, X 4 is an aromatic heterocycle, * the other It represents a bond with the child.)
Component (C): a diamine having at least one structure selected from the following formula (a) and the following formula (b)

(In the formula, X 1 is an oxygen atom or a sulfur atom, A 1 to A 3 are each independently a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and the total number of carbon atoms is 1 to 9. * Represents a bond with another atom.)