WO2013035803A1

WO2013035803A1 - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: WO2013035803A1
Application number: PCT/JP2012/072781
Authority: WO
Inventors: 徳俊三木; 雅章片山; 耕平後藤; 保坂　和義
Original assignee: 日産化学工業株式会社
Priority date: 2011-09-08
Filing date: 2012-09-06
Publication date: 2013-03-14
Also published as: KR101951501B1; CN106635061A; KR20180072830A; JP6011537B2; KR20140059219A; CN106635061B; JP2016194707A; CN103782231B; KR20190124815A; TWI586757B; TWI620794B; JPWO2013035803A1; JP6414145B2; TW201323521A; KR102224531B1; CN103782231A; TW201726811A

Abstract

Provided is a liquid crystal aligning agent which has high wettability and spreadability over substrates and is capable of providing a liquid crystal alignment film that has excellent coating film uniformity and excellent coating film properties in the end portions, said liquid crystal alignment film enabling the achievement of pretilt angles that do not change even if left at high temperatures or irradiated with light for a long period of time. A liquid crystal aligning agent which contains N-ethyl-2-pyrrolidone and at least one polymer that is selected from the group consisting of polyimide precursors having a side chain represented by formula [1] and polyimides. (In the formula, each of X₁, X₂ and X₃ independently represents a single bond or the like; each of X₄ and X₅ independently represents a benzene ring or the like; X₆ represents an alkyl group having 1-18 carbon atoms, or the like; and n represents an integer of 0-4.)

Description

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

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

Currently, a liquid crystal alignment film used for a liquid crystal display element is required to have many characteristics. One of the characteristics is control of the so-called pretilt angle of the liquid crystal, in which the alignment tilt angle of the liquid crystal molecules with respect to the substrate surface is maintained at an arbitrary value. It is known that the magnitude of the pretilt angle can be changed by selecting the structure of the polyimide constituting the liquid crystal alignment film. Among the techniques for controlling the pretilt angle depending on the structure of the polyimide, the method using a diamine compound having a side chain as a part of the polyimide raw material can control the pretilt angle according to the use ratio of the diamine compound. Therefore, it is relatively easy to obtain the target pretilt angle, which is useful as a means for increasing the pretilt angle. As the side chain structure of the diamine compound that increases the pretilt angle of the liquid crystal, one containing a ring structure such as a long-chain alkyl group or fluoroalkyl group (see, for example, Patent Document 1), a phenyl group, or a cyclohexyl group has been proposed. (For example, refer to Patent Documents 2 and 3).

In recent years, liquid crystal display elements have become widely used in large-screen liquid crystal televisions and high-definition mobile applications (display parts of digital cameras and mobile phones). The unevenness of the step of the substrate is getting larger. Even in such a situation, from the viewpoint of display characteristics, it is required that the liquid crystal alignment film be uniformly formed on a large substrate or a step. When applying a liquid crystal alignment treatment agent (also referred to as a coating solution) of polyamic acid or solvent-soluble polyimide (also referred to as a resin) to the substrate in the process of producing the liquid crystal alignment film, it is industrially a flexographic printing method or an ink jet coating method. It is common to do so. At that time, the solvent of the coating solution includes N-methyl-2-pyrrolidone, γ-butyrolactone, and the like that are excellent in the solubility of the resin (also referred to as a good solvent), and the uniformity of the liquid crystal alignment film. In order to increase this, butyl cellosolve, which is a solvent having low resin solubility (also referred to as a poor solvent), or the like is mixed (for example, see Patent Document 4).

Japanese Unexamined Patent Publication No. 2-282726 Japanese Unexamined Patent Publication No. 9-278724 International Publication No. 2004/52962 Pamphlet Japanese Unexamined Patent Publication No. 2-37324

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

In the manufacturing process of the liquid crystal display element, in order to improve the alignment uniformity of the liquid crystal, the liquid crystal is encapsulated and then heat-treated to temporarily make the liquid crystal isotropic. However, when the stability of the pretilt angle is low, there arises a problem that a pretilt angle having a target size cannot be obtained after this isotropic processing or the pretilt angle varies. In particular, a liquid crystal display element using a backlight that generates a large amount of heat and has a large amount of light to obtain high brightness, such as a car navigation system or a large television, is exposed to high temperature and light irradiation for a long time. In some environments, it may be used or left unattended. Under such severe conditions, when the pretilt angle is gradually changed, problems such as inability to obtain initial display characteristics or occurrence of unevenness in display occur.

Moreover, the coating-film uniformity of a liquid crystal aligning film exists in the tendency for the liquid-crystal aligning agent using the polyamic acid obtained by using the diamine compound which has a side chain, or a solvent soluble polyimide to fall. In particular, when uniform coating properties cannot be obtained, i.e., when repelling or pinholes occur, when the liquid crystal display element is formed, that portion becomes a display defect. Therefore, it is necessary to increase the mixing amount of the poor solvent having high wettability of the coating solution to the substrate, but the poor solvent is inferior in the ability to dissolve the polyamic acid and the solvent-soluble polyimide. There is a problem that precipitation occurs.
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, a sealant used for bonding the substrates of the liquid crystal display elements is present at a position close to the end of the liquid crystal alignment film. Therefore, when the coating property of the end portion of the liquid crystal alignment film is deteriorated, that is, when the end portion of the liquid crystal alignment film is not straight or the end portion is raised, adhesion between the substrates of the sealing agent is performed. The effect is reduced, and the display characteristics and reliability of the liquid crystal display element are lowered.

The present invention has been made in view of the above circumstances. That is, the problem to be solved by the present invention is to provide a liquid crystal alignment film whose pretilt angle does not change even when exposed to high temperature and light irradiation for a long time. In addition, even a liquid crystal alignment treatment agent using a polyamic acid or a solvent-soluble polyimide obtained by using a diamine compound having a side chain has high wettability of the coating solution on the substrate and a uniform coating property. Furthermore, it is providing the liquid crystal aligning film which is excellent also in the coating property of the edge part of a liquid crystal aligning film. Furthermore, it is providing the liquid crystal aligning agent which can provide the liquid crystal display element which has said liquid crystal aligning film, and said liquid crystal aligning film.

As a result of intensive studies, the present inventor has found that a liquid crystal aligning agent containing a solvent having a specific structure and a polymer having a side chain having a specific structure is extremely effective for achieving the above object. The present invention has been completed.
That is, the present invention has the following gist.
(1) A liquid crystal aligning agent comprising the following component (A) and component (B).
Component (A): N-ethyl-2-pyrrolidone.
Component (B): at least one polymer selected from the group consisting of a polyimide precursor having a side chain represented by the following formula [1] and a polyimide obtained by imidizing the polyimide precursor.

(In the formula [1], X ₁ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH. —, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—, X ₂ is a single bond or — (CH ₂ ) _b— (b is an integer of 1 to 15.) X ₃ is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —NH—, — _{N (CH 3) -, -} CONH -, - NHCO -, - CH 2 O -, - COO -, - OCO -, - CON (CH 3) - or -N _(CH 3) is CO- .X ₄ Is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring (any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, carbon C 1-3 alkoxyl group, a fluorine-containing alkyl group having 1 to 3 carbon atoms, .X ₅ benzene rings and may be substituted with a fluorine-containing alkoxyl group or a fluorine atom having 1 to 3 carbon atoms), cyclohexyl A divalent cyclic group selected from a ring and a heterocyclic ring (an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or fluorine having 1 to 3 carbon atoms) X ₆ represents an alkyl group having 1 to 18 carbon atoms, or a fluorine-containing alkyl group having 1 to 18 carbon atoms, which may be substituted with a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom. And an alkoxyl group having 1 to 18 carbon atoms or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms, and n is an integer of 0 to 4.)

(2) The component (B) is selected from the group consisting of a polyimide precursor using a diamine compound having a side chain represented by the formula [1] as a part of the raw material and a polyimide obtained by imidizing the polyimide precursor. The liquid-crystal aligning agent as described in said (1) which is an at least 1 sort (s) of polymer.
(3) The liquid-crystal aligning agent as described in said (2) whose diamine compound which has a side chain shown by said Formula [1] is a diamine compound shown by following formula [1a].

(In the formula [1a], X ₁ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH —, —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—, X ₂ is a single bond or — (CH ₂ ) _b— (b is an integer of 1 to 15.) X ₃ is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —NH—, — _{N (CH 3) -, -} CONH -, - NHCO -, - CH 2 O -, - COO -, - OCO -, - CON (CH 3) - or -N _(CH 3) a CO- .X ₄ Is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring (an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, Prime 1-3 alkoxyl group, a fluorine-containing alkyl group having 1 to 3 carbon atoms, .X ₅ benzene rings and may be substituted with a fluorine-containing alkoxyl group or a fluorine atom having 1 to 3 carbon atoms), cyclohexyl A divalent cyclic group selected from a ring and a heterocyclic ring (an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or fluorine having 1 to 3 carbon atoms) X ₆ represents an alkyl group having 1 to 18 carbon atoms, or a fluorine-containing alkyl group having 1 to 18 carbon atoms, which may be substituted with a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom. And an alkoxyl group having 1 to 18 carbon atoms or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms, n is an integer of 0 to 4, and m is an integer of 1 to 4.)
(4) The liquid crystal aligning agent according to the above (2) or (3), wherein the diamine represented by the formula [1a] is used in an amount of 5 to 80 mol% of the starting diamine component.

(5) The liquid crystal aligning agent according to any one of the above (1) to (4), wherein the component (B) is a polymer using a tetracarboxylic dianhydride represented by the following formula [2].

(In Formula [2], Y ₁ is a tetravalent organic group having 4 to 13 carbon atoms and contains a non-aromatic cyclic hydrocarbon group having 4 to 10 carbon atoms.)
(6) The liquid crystal aligning agent according to (5), wherein Y ₁ is a group having a structure represented by the following formulas [2a] to [2j].

(In Formula [2a], Y ₂ to Y ₅ are a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different. In Formula [2g], Y ₆ and Y ₇ Are hydrogen atoms or methyl groups, which may be the same or different.
(7) The liquid crystal aligning agent according to any one of (1) to (6), wherein the polymer as the component (B) is a polyamic acid.
(8) The liquid crystal aligning agent according to any one of the above (1) to (6), wherein the polymer as the component (B) is a polyimide obtained by dehydrating and ring-closing polyamic acid.

(9) The liquid crystal aligning agent according to any one of the above (1) to (8), which contains N-methyl-2-pyrrolidone or γ-butyrolactone as the component (C).
(10) As component (D), 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, Any one of (1) to (9) above containing at least one selected from the group consisting of diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monobutyl ether Liquid crystal aligning agent.
(11) The liquid crystal aligning agent according to any one of (1) to (10), wherein the component (A) is 10 to 100% by mass of the total organic solvent contained in the liquid crystal aligning agent.
(12) The liquid crystal aligning agent according to any one of the above (9) to (11), wherein the component (C) is 0.1 to 50% by mass of the whole organic solvent contained in the liquid crystal aligning agent.
(13) The liquid crystal aligning agent according to any one of the above (10) to (12), wherein the component (D) is 5 to 80% by mass of the whole organic solvent contained in the liquid crystal aligning agent.
(14) The liquid crystal aligning agent according to any one of (1) to (13), wherein the component (B) in the liquid crystal aligning agent is 0.1 to 15% by mass.

(15) A liquid crystal alignment film obtained using the liquid crystal aligning agent according to any one of (1) to (14).
(16) A liquid crystal alignment film obtained by an ink jet method using the liquid crystal alignment treatment agent according to any one of (1) to (14).
(17) A liquid crystal display device having the liquid crystal alignment film according to (15) or (16).
(18) A liquid crystal composition having a liquid crystal layer between a pair of substrates provided with electrodes and including a polymerizable compound that is polymerized by at least one of active energy rays and heat is disposed between the pair of substrates. The liquid crystal alignment film as described in (15) or (16) above, which is used for a liquid crystal display device produced through a step of polymerizing the polymerizable compound while applying a voltage between the electrodes.

(19) A liquid crystal display element comprising the liquid crystal alignment film according to (18).
(20) A polymerizable compound having a liquid crystal layer between a pair of substrates provided with an electrode and the liquid crystal alignment film, and polymerized by at least one of active energy rays and heat between the pair of substrates. The liquid crystal display element according to (19), wherein the liquid crystal display element is produced through a step of disposing a liquid crystal composition and polymerizing the polymerizable compound while applying a voltage between the electrodes.
(21) A liquid crystal alignment film comprising a liquid crystal layer between a pair of substrates provided with electrodes and including a polymerizable group that is polymerized by at least one of active energy rays and heat is disposed between the pair of substrates. The liquid crystal alignment film as described in (15) or (16) above, which is used for a liquid crystal display device produced through a step of polymerizing the polymerizable group while applying a voltage between the electrodes.
(22) A liquid crystal display element comprising the liquid crystal alignment film according to (21).
(23) A liquid crystal alignment film having a liquid crystal layer between a pair of substrates provided with electrodes and including a polymerizable group that is polymerized by at least one of active energy rays and heat is disposed between the pair of substrates. The liquid crystal display element according to (22), wherein the liquid crystal display element is manufactured through a step of polymerizing the polymerizable group while applying a voltage between the electrodes.

According to the liquid crystal alignment treatment agent of the present invention, a liquid crystal alignment film whose pretilt angle does not change even when exposed to a high temperature or light irradiation for a long time is obtained, and further, the wettability of the solution to the substrate is high, A liquid crystal alignment film excellent in coating film uniformity can be obtained for a large substrate or a stepped substrate. By using such a liquid crystal alignment film, it is possible to provide a highly reliable liquid crystal display element having excellent display characteristics.

The example of the coating-film image of the optical microscope used in order to evaluate the linearity of the edge part of a liquid crystal aligning film. The example of the coating-film image of the optical microscope used in order to evaluate the swelling of the edge part of a liquid crystal aligning film.

The liquid crystal aligning agent of the present invention comprises N-ethyl-2-pyrrolidone (also referred to as a specific solvent) as component (A) and a side chain represented by the above formula [1] as component (B) ( It contains at least one polymer (also referred to as a specific polymer) selected from the group consisting of a polyimide precursor having a specific side chain structure) and a polyimide obtained by imidizing the polyimide precursor.

The specific solvent in the present invention is a good solvent excellent in solubility of polyamic acid or soluble polyimide. Furthermore, the surface tension as a solvent is lower than that of commonly used N-methyl-2-pyrrolidone and γ-butyrolactone. Therefore, a liquid crystal alignment treatment agent using a specific solvent has a higher wettability of the coating solution applied to the substrate and uses a poor solvent having a low resin solubility than a liquid crystal alignment treatment agent that does not use it. Even if not, a liquid crystal alignment film excellent in coating film uniformity can be obtained. Furthermore, since the wet spreading property of the coating solution is increased, the linearity of the end portion when the liquid crystal alignment film is formed is increased.
In addition, since the specific solvent has a higher boiling point than the commonly used N-methyl-2-pyrrolidone and γ-butyrolactone, the liquid crystal aligning agent using the specific solvent is obtained when the liquid crystal alignment film is used. Swelling at the end can be suppressed.

The specific side chain structure in this invention has a benzene ring, a cyclohexyl ring, or a heterocyclic ring in a side chain part. These benzene ring, cyclohexyl ring or heterocyclic ring show a rigid structure as compared with the long-chain alkyl group of the prior art. As a result, the stability of the side chain site to heat and ultraviolet light is improved, and a liquid crystal alignment film having a stable pretilt angle against heat and light can be obtained. In addition, although these benzene rings, cyclohexyl rings, and heterocycles exhibit a rigid structure, the polymers have higher solubility in organic solvents than cyclic groups composed of steroid skeletons of the prior art. Therefore, the liquid crystal aligning agent having a specific side chain structure of the present invention has higher application uniformity to the substrate than the liquid crystal aligning agent having a cyclic group having a steroid skeleton according to the prior art.
From the above points, according to the liquid crystal aligning agent containing the specific solvent and the polymer having a specific side chain structure of the present invention, the pretilt angle does not change even when exposed to high temperature and light irradiation for a long time. A liquid crystal alignment film having excellent coating film uniformity can be obtained, and by using this liquid crystal alignment film, a highly reliable liquid crystal display element having excellent display characteristics can be obtained.

<Specific solvent>
The specific solvent of the present invention is N-ethyl-2-pyrrolidone. Since N-ethyl-2-pyrrolidone has an effect of improving the wettability of the coating solution to the substrate, it is preferably 10 to 100% by mass of the whole organic solvent contained in the liquid crystal aligning agent. Of these, 15 to 100% by mass of the whole organic solvent is preferable, more preferably 20 to 100% by mass, and still more preferably 25 to 100% by mass.
The greater the amount of the specific solvent of the present invention in the whole organic solvent in the liquid crystal aligning agent, the higher the effect of the present invention, that is, the wet spreading property of the coating solution to the substrate, and the more uniform the coating film. An excellent liquid crystal alignment film can be obtained.

<Specific side chain structure>
The specific polymer of the present invention, that is, at least one selected from the group consisting of a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor has a specific side chain structure represented by the following formula [1].

In the formula [1], X ₁ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH— , —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—. Among them, a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CONH—, —CH ₂ O—, or —COO— It is preferable because it is easy. More preferably, they are a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 10), —O—, —CONH—, —CH ₂ O— or —COO—. More preferably, they are a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 10), —O—, —CH ₂ O— or —COO—.
X ₂ is a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15). Among these, a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 10) is preferable.

X ₃ is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, — CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—. Among these, a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or —OCO— is preferable because they are easily synthesized. More preferably, they are a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —CH ₂ O—, —COO— or —OCO—.
X ₄ is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring. The optional hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 3 carbon atoms. Alternatively, it may be substituted with a fluorine atom. Especially, as a bivalent cyclic group, a benzene ring or a cyclohexyl ring is preferable.

X ₅ is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring. Arbitrary hydrogen atoms on these cyclic groups include an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, and a fluorine-containing alkoxyl having 1 to 3 carbon atoms. It may be substituted with a group or a fluorine atom. Especially, as a bivalent cyclic group, a benzene ring or a cyclohexane ring is preferable.
n is an integer of 0 to 4, preferably an integer of 0 to 2.
X ₆ is an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms. Of these, an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 10 carbon atoms is preferable. More preferably, it is an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. More preferred is an alkyl group having 1 to 9 carbon atoms or an alkoxyl group having 1 to 9 carbon atoms.

_X _1, X _2, _X 3 in the formula [1], the X _4, X 5, preferred combinations of _{X 6} and n, 13 pp to 33 pages of International Publication WO2011 / 132751 (2011.10.27 public) The same combinations as (2-1) to (2-600) listed in Tables 6 to 45 are listed. In each table of the International Publication, X ₁ to X ₆ in the present invention are indicated as Y 1 to Y _6, but Y 1 to Y ₆ should be read as X ₁ to X ₆ .

<Specific side chain diamine compound>
As a specific polymer of the present invention, that is, a method for introducing a specific side chain structure represented by the formula [1] into at least one selected from the group consisting of a polyimide precursor and a polyimide obtained by imidizing a polyimide precursor, It is preferable to use a diamine compound having a side chain structure as a part of the raw material. In particular, it is preferable to use a diamine compound represented by the following formula [1a] (also referred to as a specific side chain diamine compound).

In the formula [1a], X ₁ is a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH— , —NHCO—, —CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—. Among them, a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 15), —O—, —CONH—, —CH ₂ O—, or —COO— It is preferable because it is easy. More preferably, they are a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 10), —O—, —CONH—, —CH ₂ O— or —COO—. More preferably, they are a single bond, — (CH ₂ ) _a — (a is an integer of 1 to 10), —O—, —CH ₂ O— or —COO—.

X ₂ is a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 15). Among these, a single bond or — (CH ₂ ) _b — (b is an integer of 1 to 10) is preferable.
X ₃ is a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, — CH ₂ O—, —COO—, —OCO—, —CON (CH ₃ ) — or —N (CH ₃ ) CO—. Among these, a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 15), —O—, —CH ₂ O—, —COO— or —OCO— is preferable because they are easily synthesized. More preferably, they are a single bond, — (CH ₂ ) _c — (c is an integer of 1 to 10), —O—, —CH ₂ O—, —COO— or —OCO—.
X ₄ is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring or a heterocyclic ring. The optional hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 3 carbon atoms. Alternatively, it may be substituted with a fluorine atom. Especially, as a bivalent cyclic group, a benzene ring or a cyclohexyl ring is preferable.

X ₅ is a divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring. Arbitrary hydrogen atoms on these cyclic groups include an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, and a fluorine-containing alkoxyl having 1 to 3 carbon atoms. It may be substituted with a group or a fluorine atom. Especially, as a bivalent cyclic group, a benzene ring or a cyclohexyl ring is preferable.
n is an integer of 0 to 4, preferably an integer of 0 to 2.
X ₆ is an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms. Of these, an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 10 carbon atoms is preferable. More preferably, it is an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. More preferred is an alkyl group having 1 to 9 carbon atoms or an alkoxyl group having 1 to 9 carbon atoms.

A preferable combination of X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ and n in the formula [1a] is the same as that in the formula [1].
Among the combinations of X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ and n in the formula [1], more preferred combinations are 1-25 to 1-96, 1-145 to 1-168, -217 to 1-240, 1-268 to 1-315, 1-364 to 1-387, 1-436 to 1-483, and the like. Particularly preferred combinations are 1-49 to 1-96, 1-145. ˜1-168, 1-217˜1-240, etc.
In the formula [1a], m is an integer of 1 to 4, preferably 1.

Specifically, the formula [1a] is, for example, a structure represented by the following formulas [1-1] to [1-13].

(In the formulas [1-1] to [1-3], R ₁ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or CH ₂ OCO—, and R ₂ represents a straight chain. Or a branched or branched alkyl group having 1 to 22 carbon atoms, an alkoxyl group having 1 to 22 carbon atoms, a fluorine-containing alkyl group having 1 to 22 carbon atoms, or a fluorine-containing alkoxyl group having 1 to 22 carbon atoms.)

(In the formulas [1-4] to [1-6], R ₃ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O —, —OCH ₂ — or —CH ₂ —, wherein R ₄ is a linear or branched alkyl group having 1 to 22 carbon atoms, an alkoxyl group having 1 to 22 carbon atoms, or fluorine having 1 to 22 carbon atoms. A containing alkyl group or a fluorine-containing alkoxyl group having 1 to 22 carbon atoms.)

(In the formulas [1-7] and [1-8], R ₅ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O —, —OCH ₂ —, —CH ₂ —, —O— or —NH—, and R ₆ represents a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group or It is a hydroxyl group.)

(In the formulas [1-9] and [1-10], R ₇ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is Trans isomer.)

(In the formulas [1-11] and [1-12], R ₈ is a linear or branched alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is trans Is an isomer.)

(In the formula [1-13], A ₄ is a linear or branched alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₃ is a 1,4-cyclohexylene group. Alternatively, it is a 1,4-phenylene group, A ₂ is an oxygen atom or COO— * (where a bond marked with “*” is bonded to A ₃ ), and A ₁ is an oxygen atom or COO — * ( However, a bond marked with “*” is combined with (CH ₂ ) a ₂ ).
A ₁ is 0 or 1, a ₂ is an integer of 2 to 10, and a ₃ is 0 or 1. )

Among the above formulas [1-1] to [1-13], particularly preferred diamine compounds have the formulas [1-1] to [1-6], the formulas [1-9] to [1-13], etc. It is.
Said specific side chain type diamine compound can also be used 1 type or in mixture of 2 or more types according to characteristics, such as liquid crystal orientation at the time of setting it as a liquid crystal aligning film, a voltage holding ratio, and an accumulation charge.

<Other diamine compounds>
In the present invention, as long as the effects of the present invention are not impaired, other diamine compounds (also referred to as other diamine compounds) other than the specific side chain diamine compound can be used as the diamine component of the raw material. Specific examples are given below.
p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-diph Fluoro-4,4′-biphenyl, 3,3′-trifluoromethyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2′-diaminodiphenylmethane, 2,3′-diaminodiphenylmethane, 4, 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3 '-Sulphonyldianiline, bis (4-aminophenyl) silane, bis (3-amino Nophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3,3′-thiodianiline, 4,4′-diaminodiphenylamine, 3, 3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl) amine, N-methyl (3,3 3'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone 1,4-diaminonaphthalene, 2,2′-diaminobenzophenone, 2,3′-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8- Diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4-aminophenyl) ethane, 1,2-bis ( 3-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis (4aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl-4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene Zen, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-amino) Benzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 ′-[1,3-phenylenebis (methylene) ] Dianiline, 3,4 '-[1,4-phenylenebis (methylene)] dianiline, 3,4'-[1,3-phenylenebis (methylene)] dianiline, 3,3 '-[1,4-phenylene Bis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3 -A Nophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis ( 3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N '-(1,3-phenylene) bis (4-aminobenzamide), N, N'-(1,4-phenylene) (3-aminobenzamide), N, N ′-(1,3-phenylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis ( 3-aminophenyl) terephthalamide, N, N′-bis (4-aminophenyl) isophthalamide, N, N′-bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, 2,2′-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 2,2′-bis (4-aminophenyl) hexafluoropropane, 2,2′-bis (3-aminophenyl) hexafluoropropane 2,2′-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2′-bis (4-aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2, 2'-bis (3-amino-4-methylphenyl) propane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, 1,3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,5 -Bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,6-bis (3-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) ) Heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-amino) Phenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, 1,10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) ) Aromatic diamine compounds such as undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12- (3-aminophenoxy) dodecane; bis (4-amino Cyclohexane) methane, alicyclic diamine compounds such as bis (4-amino-3-methylcyclohexyl) methane; 1,3-diaminopropane 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, Aliphatic diamine compounds such as 1,11-diaminoundecane and 1,12-diaminododecane.

Moreover, as long as the effect of this invention is not impaired, the diamine compound which has an alkyl group or a fluorine-containing alkyl group in a diamine side chain can be used.
Specifically, for example, diamine compounds represented by the following formulas [DA1] to [DA12] can be exemplified.

(In the formulas [DA1] to [DA5], A ₁ is a linear or branched alkyl group having 1 to 22 carbon atoms or a linear or branched fluorine-containing alkyl group having 1 to 22 carbon atoms. )

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

(In the formula [DA12], p is an integer of 1 to 10)

As long as the effects of the present invention are not impaired, diamine compounds represented by the following formulas [DA13] to [DA20] can also be used.

(In the formula [DA17], m is an integer of 0 to 3. In the formula [DA20], n is an integer of 1 to 5.)

Furthermore, as long as the effects of the present invention are not impaired, a diamine compound having a carboxyl group in the molecule represented by the following formulas [DA21] to [DA24] can also be used.

(In the formula [DA21], m ₁ is an integer of 1 to 4.
In the formula [DA22], A ₄ represents a single bond, —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —O—. , —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ —, —COO—, —OCO—, —CON (CH ₃ ) — Or —N (CH ₃ ) CO—, each of m ₂ and m ₃ is an integer from 0 to 4, and m ₂ + m ₃ is an integer from 1 to 4.
In the formula [DA23], m ₄ and m ₅ are each an integer of 1 to 5. In the formula [DA24], A ₅ is a linear or branched alkyl group having 1 to 5 carbon atoms, and m ₆ is an integer of 1 to 5.
In the formula [DA25], A ₆ represents a single bond, —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —, —CF ₂ —, —C (CF ₃ ) ₂ —, —O—. , —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ —, —COO—, —OCO—, —CON (CH ₃ ) — Or —N (CH ₃ ) CO—, and m ₇ is an integer of 1 to 4. )

Furthermore, a diamine compound represented by the following formula [DA26] can also be used as long as the effects of the present invention are not impaired.

(In the formula [DA26], A ₁ is —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —OCO—, —CON (CH ₃ ). A divalent organic group selected from — or —N (CH ₃ ) CO—, and A ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group or an aromatic group. A ₃ is a single bond, —O—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, —OCO—, —CON (CH ₃ ). -, -N (CH ₃ ) CO- or -O (CH ₂ ) _m- (m is an integer of 1 to 5), A ₄ is a nitrogen-containing aromatic heterocycle, and n is 1 to 4 Is an integer.)

Furthermore, a diamine compound having a steroid skeleton represented by the following formulas [DA27] to [DA46] can also be used as long as the effects of the present invention are not impaired.

Said other diamine compound can also be used 1 type or in mixture of 2 or more types according to characteristics, such as liquid crystal orientation at the time of setting it as a liquid crystal aligning film, a voltage holding ratio, and an accumulation charge.

<Specific tetracarboxylic dianhydride>
In order to obtain the specific polymer of the present invention, it is preferable to use a tetracarboxylic dianhydride (also referred to as a specific tetracarboxylic dianhydride) represented by the following formula [2] as a part of the raw material.

In the formula [2], Y ₁ is a tetravalent organic group having 4 to 13 carbon atoms and contains a non-aromatic cyclic hydrocarbon group having 4 to 10 carbon atoms.

Specifically, Y ₁ in the formula [2] is, for example, a tetravalent group represented by the following formulas [2a] to [2j].

In the formula [2a], Y ₂ to Y ₅ are a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different.
In formula [2g], Y ₆ and Y ₇ are a hydrogen atom or a methyl group, and may be the same or different.
In formula [2], particularly preferred structure of Y ₁ is represented by formula [2a], formula [2c], formula [2d], formula [2e], formula [2f] or formula because of polymerization reactivity and ease of synthesis. [2g]. Among these, the formula [2a], the formula [2e], the formula [2f], or the formula [2g] is preferable.

<Other tetracarboxylic dianhydrides>
In the present invention, other tetracarboxylic dianhydrides other than the specific tetracarboxylic dianhydride (also referred to as other tetracarboxylic dianhydrides) can be used as long as the effects of the present invention are not impaired. Examples of other tetracarboxylic dianhydrides include tetracarboxylic dianhydrides of the following tetracarboxylic acids.
Pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7 -Anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4-biphenyltetracarboxylic acid, bis ( 3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2 , 2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) propane, bi (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4-dicarboxy) Phenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid or 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid.
The above-mentioned specific tetracarboxylic dianhydride and other tetracarboxylic dianhydrides may be used alone or in combination of two or more depending on properties such as liquid crystal orientation, voltage holding ratio, and accumulated charge when used as a liquid crystal alignment film. It can also be used as a mixture.

<Specific polymer>
The specific polymer of the present invention is at least one polymer selected from the group consisting of a polyimide precursor having a side chain represented by the formula [1] and a polyimide obtained by imidizing the polyimide precursor.
The polyimide precursor has a structure represented by the following formula [A].

(In the formula [A], R ₁ is a tetravalent organic group, R ₂ is a divalent organic group, A ₁ and A ₂ are a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, (It may be the same or different, and n represents a positive integer.)

Reason that the specific polymer of the present invention can be obtained relatively easily by using a diamine component represented by the following formula [B] and a tetracarboxylic dianhydride represented by the following formula [C] as raw materials. Therefore, a polyamic acid having a structural formula of a repeating unit represented by the following formula [D] or a polyimide obtained by imidizing the polyamic acid is preferable.

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

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

In the present invention, the method for synthesizing the specific polymer is not particularly limited. Usually, it is obtained by reacting a diamine component and a tetracarboxylic acid component. Generally, at least one tetracarboxylic acid component selected from the group consisting of tetracarboxylic acids and derivatives thereof is reacted with a diamine component consisting of one or more diamine compounds to obtain a polyamic acid. Specifically, a method of obtaining polyamic acid by polycondensation of tetracarboxylic dianhydride and a diamine component, a method of obtaining polyamic acid by dehydration polycondensation reaction of tetracarboxylic acid and a diamine component, or tetracarboxylic acid dihalide A method is used in which a polyamic acid is obtained by polycondensation of a diamine component and diamine component.
Polyamide acid alkyl ester can be obtained by polycondensation of carboxylic acid group with dialkyl esterified tetracarboxylic acid and diamine component, tetracarboxylic acid dihalide with carboxylic acid group dialkylesterified and diamine component. A method or a method of converting a carboxyl group of a polyamic acid into an ester is used.
In order to obtain polyimide, a method is used in which the polyamic acid or polyamic acid alkyl ester is cyclized to form polyimide.

The liquid crystal alignment film obtained using the specific polymer of the present invention is more hydrophobic and liquid crystal when the liquid crystal alignment film is used as the content of the specific side chain structure represented by the formula [1] in the diamine component increases. The pretilt angle can be increased. In that case, it is preferable to use the specific side chain type diamine compound shown by the said Formula [1a] for a diamine component. Particularly preferably, at least one selected from the group consisting of the specific side chain diamine compounds represented by the formulas [1-1] to [1-6] and the formulas [1-9] to [1-13] is used. That is. Among them, at least one selected from the group consisting of specific side chain diamine compounds represented by formulas [1-1] to [1-6] or formulas [1-9] to [1-12] may be used. preferable. In order to enhance this property, it is preferable that 5 mol% or more and 80 mol% or less of the diamine component is the specific side chain type diamine compound. Especially, it is preferable that 5 mol% or more and 60 mol% or less of a diamine component are a specific side chain type diamine compound from the viewpoint of the applicability | paintability of a liquid crystal aligning agent, and the electrical property as a liquid crystal aligning film. More preferably, it is 10 mol% or more and 60 mol% or less of the diamine component.

In order to obtain the specific polymer of this invention, it is preferable to use the specific tetracarboxylic dianhydride shown by said Formula [2] as a tetracarboxylic acid component. In particular, it is preferable to use a tetracarboxylic dianhydride in which Y ₁ in the formula [2] is a group having a structure represented by the formulas [2a] to [2j]. In that case, it is preferable that 1 mol% or more of a tetracarboxylic acid component is a specific tetracarboxylic dianhydride, More preferably, it is 5 mol% or more, More preferably, it is 10 mol% or more. Further, 100 mol% of the tetracarboxylic acid component may be a specific tetracarboxylic dianhydride.
The reaction of the diamine component and the tetracarboxylic acid component is usually performed in an organic solvent. The organic solvent used in that case may be the specific solvent of the present invention, and is not particularly limited as long as the produced polyimide precursor is dissolved. Specific examples are given below.

For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4 -Hydroxy-4-methyl-2-pentanone and the like.
These may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polyimide precursor, you may mix and use the said solvent in the range which the produced | generated polyimide precursor does not precipitate. Moreover, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyimide precursor, it is preferable to use a dehydrated and dried organic solvent.

When the diamine component and the tetracarboxylic acid component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic acid component is dispersed or dissolved in the organic solvent as it is. And a method of adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic acid component in an organic solvent, a method of alternately adding a tetracarboxylic acid component and a diamine component, etc. Any of these methods may be used. In addition, when reacting using a plurality of diamine components or tetracarboxylic acid components, they may be reacted in a premixed state, individually or sequentially, or further individually reacted low molecular weight substances. May be mixed and reacted to form a specific polymer. In this case, the polymerization temperature can be selected from -20 to 150 ° C., but is preferably in the range of −5 to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a specific polymer having a high molecular weight, and if the concentration is too high, the viscosity of the reaction solution will become too high and uniform stirring will occur. It becomes difficult. Therefore, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

In the polymerization reaction of the polyimide precursor, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably 0.8 to 1.2. Similar to a normal polycondensation reaction, the molecular weight of the polyimide precursor formed increases as the molar ratio approaches 1.0.
The polyimide of the present invention is a polyimide obtained by ring-closing the above polyimide precursor, and is useful as a polymer for obtaining a liquid crystal alignment film.
In the polyimide of the present invention, the cyclization rate (also referred to as imidization rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.

Examples of the method for imidizing the polyimide precursor include thermal imidization in which the polyimide precursor solution is heated as it is or catalyst imidization in which a catalyst is added to the polyimide precursor solution.
The temperature when the polyimide precursor is thermally imidized in the solution is 100 to 400 ° C., preferably 120 to 250 ° C.
A method of performing the thermal imidization reaction while removing generated water from the system is preferable.

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

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

The molecular weight of the specific polymer of the present invention is a weight average measured by a GPC (Gel Permeation Chromatography) method in consideration of the strength of the obtained polymer film, workability at the time of forming the polymer film, and uniformity of the polymer film. The molecular weight is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal alignment agent>
The liquid crystal aligning agent of this invention is a coating solution for forming a liquid crystal aligning film, and is a coating liquid for forming the resin film containing a specific solvent and a specific polymer.
The polymer component in the liquid crystal aligning agent of the present invention may all be the specific polymer of the present invention, and other polymers may be mixed with the specific polymer of the present invention. In that case, the content of the other polymer in the polymer component is 0.5 to 15% by mass, preferably 1 to 10% by mass.
As other polymers, polyimide precursors and polyimide precursors obtained from a diamine component not containing a specific side chain diamine compound and a tetracarboxylic acid component not containing a specific tetracarboxylic dianhydride were imidized. Examples thereof include at least one polymer selected from the group consisting of polyimides. Furthermore, a polyimide precursor and a polymer other than polyimide, specifically, an acrylic polymer, a methacrylic polymer, polystyrene, polyamide, a siloxane polymer, and the like can be given.

The organic solvent in the liquid crystal aligning agent of the present invention preferably contains 70 to 99% by mass of the organic solvent in the liquid crystal aligning agent from the viewpoint of forming a uniform film by coating. The content of the organic solvent can be appropriately changed depending on the film thickness of the target liquid crystal alignment film.
As the organic solvent, the specific solvent of the present invention is preferably used. In that case, the following solvent can also be used in addition to the specific solvent as long as it is an organic solvent capable of dissolving the specific polymer. Specifically, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopenta Non or 4-hydroxy-4-methyl-2-pentanone.
Among these, it is preferable to use N-methyl-2-pyrrolidone, γ-butyllactone, etc. (these are also referred to as component (C)).
The amount of the component (C) used is preferably 0.1 to 70% by mass with respect to the total organic solvent contained in the liquid crystal aligning agent. Among these, 1 to 60% by mass is preferable. The amount is more preferably 1 to 50% by mass, and further preferably 3 to 40% by mass.

The liquid crystal alignment treatment agent of the present invention is an organic solvent that improves the coating film uniformity and surface smoothness of the liquid crystal alignment film when the liquid crystal alignment treatment agent is applied, i.e., a poor solvent, as long as the effects of the present invention are not impaired. Can be used. Specific examples of the poor solvent for improving the coating film uniformity and surface smoothness of the liquid crystal alignment film are given below.
For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2- Etanji 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentane Diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2 Heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate , Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2- (methoxymethoxy) ethanol, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol hexyl ether, 2- (hexyloxy) ethanol, Furfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl Ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene group Cole monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, lactic acid Ethyl, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate Ester, lactic n- propyl ester, lactate n- butyl ester, surface tension, such as lactic isoamyl ester is low organic solvent.

Among them, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol It is preferable to use monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether or the like (these are also referred to as component (D)).
The amount of the poor solvent (component (D)) used is preferably 1 to 80% by mass of the whole organic solvent contained in the liquid crystal aligning agent. Among these, 5 to 70% by mass is preferable. More preferably, it is 10 to 70% by mass.

Preferred combinations of organic solvents in the liquid crystal aligning agent of the present invention are as shown in Tables 1 to 3.

In Tables 1 to 3, NEP represents N-ethyl-2-pyrrolidone, NMP represents N-methyl-2-pyrrolidone, γ-BL represents γ-butyrolactone, BCS represents ethylene glycol monobutyl ether, and ECS represents Ethylene glycol monoethyl ether, MC represents diethylene glycol monomethyl ether, EC represents diethylene glycol monoethyl ether, and PGME represents propylene glycol monomethyl ether.
Among these organic solvent combinations, 2-1 to 2-10, 2-14 to 2-17, 2-19 to 2-25, 2-29 to 2-32, 2-34 to 2-40, or 2 A combination of -44 to 2-46 is preferred. More preferred are combinations of 2-1 to 2-10, 2-14 to 2-17, 2-19 to 2-2-25, 2-32 or 2-38-2-40. Particularly preferred are combinations of 2-2, 2-8 to 2-10, 2-17, 2-23 to 2-25, 2-32 or 2-38 to 2-40.

As long as the effects of the present invention are not impaired, the liquid crystal aligning agent of the present invention includes a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. A crosslinkable compound having at least one substituent selected from the group or a crosslinkable compound having a polymerizable unsaturated bond can be introduced. It is preferable to have two or more of these substituents and polymerizable unsaturated bonds in the crosslinkable compound.

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

The crosslinkable compound having an oxetane group is a crosslinkable compound having at least two oxetane groups represented by the following formula [3].

Specifically, it is a crosslinkable compound represented by the following formulas [3-1] to [3-11].

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

Specifically, it is a crosslinkable compound represented by the following formulas [4-1] to [4-37].

(In the formula [4-24], n is an integer of 1 to 5. In the formula [4-25], n is an integer of 1 to 5. In the formula [4-36], n is 1 to 100. (In the formula [4-37], n is an integer of 1 to 10.)

Further, polysiloxanes having at least one structure represented by the following formulas [4-38] to [4-40] can also be mentioned.

(In the formulas [4-38] to [4-40], R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each independently a structure represented by the formula [4], a hydrogen atom, a hydroxyl group, An alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an aliphatic ring or an aromatic ring, at least one having a structure represented by the formula [4].

More specifically, compounds of the following formulas [4-41] and [4-42] can be mentioned.

(In the formula [4-42], n is an integer of 1 to 10)

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

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

Examples of the benzene or phenolic compound having a hydroxyl group or an alkoxyl group include 1,3,5-tris (methoxymethyl) benzene, 1,2,4-tris (isopropoxymethyl) benzene, 1,4-bis ( sec-butoxymethyl) benzene, 2,6-dihydroxymethyl-p-tert-butylphenol and the like.
Specifically, the crosslinkable compounds represented by the formulas [6-1] to [6-48], which are listed on pages 62 to 66 of International Publication No. WO2011 / 132751 (published 2011.10.27). It is done.

Examples of the crosslinkable compound having a polymerizable unsaturated bond include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and tri (meth) acryloyloxyethoxytrimethylol. Crosslinkable compounds having three polymerizable unsaturated groups in the molecule such as propane and glycerin polyglycidyl ether poly (meth) acrylate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) Acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide bisphenol A type di (meth) acrylate, propylene oxide bisphenol type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di (meth) Acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, neopentyl glycol dihydroxypivalate ( Crosslinkable compounds having two polymerizable unsaturated groups in the molecule such as (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropylene (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl ( Crosslinkable compounds having one polymerizable unsaturated group in the molecule such as (meth) acrylate, glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate ester, N-methylol (meth) acrylamide; Can be mentioned.
Furthermore, a compound represented by the following formula [6] can also be used.

In Formula [6], E ₁ is a group selected from the group consisting of a cyclohexane ring, a bicyclohexane ring, a benzene ring, a biphenyl ring, a terphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, and a phenanthrene ring, and E ₂ Is a group selected from the following formulas [6a] and [6b], and n is an integer of 1 to 4.

The said compound is an example of a crosslinkable compound, It is not limited to these.
Moreover, the crosslinkable compound contained in the liquid-crystal aligning agent of this invention may be one type, and may combine two or more types.
The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of all polymer components. In order for the crosslinking reaction to proceed and to exhibit the desired effect and not to reduce the orientation of the liquid crystal, the amount is more preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of all polymer components, and 1 to 50 parts by weight. Part is most preferred.

As a compound that promotes charge transfer in a liquid crystal alignment film formed by using the liquid crystal alignment treatment agent of the present invention and promotes charge release of a liquid crystal cell using the liquid crystal alignment film, International Publication No. WO2011 / 132751 (2011). Of the nitrogen-containing heterocyclic amine compounds represented by the formulas [M1] to [M156], which are listed on pages 69 to 73 of the publication of .10.27). These amine compounds may be added directly to the solution of the specific polymer, but may be added after a solution having a concentration of 0.1 to 10% by mass, preferably 1 to 7% by mass with an appropriate solvent. preferable. The solvent is not particularly limited as long as it is an organic solvent that dissolves the specific polymer described above.

As long as the effects of the present invention are not impaired, the liquid crystal aligning agent of the present invention can use a compound that improves the uniformity of the film thickness and surface smoothness of the polymer film when the liquid crystal aligning agent is applied. . Furthermore, a compound that improves the adhesion between the liquid crystal alignment film and the substrate can also be used.
Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.
More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.) and the like. The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent. It is.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl -2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like.

When using a compound that improves the adhesion to the substrate, it is preferably 0.1 to 30 parts by mass, more preferably 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent. 1 to 20 parts by mass. If the amount is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may be deteriorated.
The liquid crystal alignment treatment agent of the present invention impairs the effects of the present invention, in addition to the above poor solvent, crosslinkable compound, compound for improving film thickness uniformity and surface smoothness, and compound for adhering to a substrate. If it is within the range, a dielectric or conductive material may be added for the purpose of changing electrical characteristics such as dielectric constant and conductivity of the liquid crystal alignment film.

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

The method for applying the liquid crystal aligning agent is not particularly limited, but industrially, screen printing, offset printing, flexographic printing, inkjet method, and the like are common. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.
After the liquid crystal alignment treatment agent is applied on the substrate, the solvent is evaporated at 50 to 300 ° C., preferably 80 to 250 ° C. by a heating means such as a hot plate, a heat circulation type oven, or an IR (infrared) type oven. It can be a united film. If the thickness of the polymer film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. Is 10 to 100 nm.
When the liquid crystal is horizontally or tilted, the polymer film after baking is treated with rubbing or irradiation with polarized ultraviolet rays.

The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal alignment treatment agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.
As a liquid crystal cell manufacturing method, a pair of substrates on which a liquid crystal alignment film is formed are prepared, spacers are dispersed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside, so that the other Examples include a method of bonding substrates and injecting liquid crystal under reduced pressure and a method of sealing liquid crystal by dropping a liquid crystal on a liquid crystal alignment film surface on which spacers are dispersed.

Furthermore, the liquid-crystal aligning agent of this invention has a liquid-crystal layer between a pair of board | substrates provided with the electrode, The polymeric compound superposed | polymerized by at least one of an active energy ray and a heat | fever between a pair of board | substrates. The liquid crystal composition is preferably used also for a liquid crystal display device produced through a step of polymerizing a polymerizable compound by applying active energy rays and heating while applying a voltage between electrodes. Here, ultraviolet rays are suitable as the active energy ray.
The liquid crystal display element controls a pretilt of liquid crystal molecules by a PSA (Polymer Sustained Alignment) method. In the PSA method, a small amount of a photopolymerizable compound, for example, a photopolymerizable monomer is mixed in a liquid crystal material, and after assembling a liquid crystal cell, a predetermined voltage is applied to the liquid crystal layer and the photopolymerizable compound is irradiated with ultraviolet light. The pretilt of the liquid crystal molecules is controlled by the produced polymer. Since the alignment state of the liquid crystal molecules when the polymer is formed is stored even after the voltage is removed, the pretilt of the liquid crystal molecules can be adjusted by controlling the electric field formed in the liquid crystal layer. The PSA method does not require a rubbing process and is suitable for forming a vertical alignment type liquid crystal layer in which it is difficult to control the pretilt by the rubbing process.

That is, in the liquid crystal display element of the present invention, a liquid crystal cell is prepared 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 a polymerizable compound is obtained by at least one of ultraviolet irradiation and heating. The orientation of the liquid crystal molecules can be controlled by polymerizing.
To give an example of manufacturing a PSA type liquid crystal cell, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers are dispersed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside. Then, the other substrate is bonded, the liquid crystal is injected under reduced pressure and sealed, the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed, and then the substrate is bonded and sealed. .

The liquid crystal is mixed with a polymerizable compound that is polymerized by heat or ultraviolet irradiation. Examples of the polymerizable compound include compounds having at least one polymerizable unsaturated group such as an acrylate group or a methacrylate group in the molecule. In that case, the polymerizable compound is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal component. When the polymerizable compound is less than 0.01 part by mass, the polymerizable compound is not polymerized and the alignment of the liquid crystal cannot be controlled, and when it exceeds 10 parts by mass, the amount of unreacted polymerizable compound increases and the liquid crystal display The burn-in characteristic of the element is deteriorated.
After the liquid crystal cell is produced, the polymerizable compound is polymerized by irradiating heat or ultraviolet rays while applying an AC or DC voltage to the liquid crystal cell. Thereby, the alignment of the liquid crystal molecules can be controlled.

Furthermore, the liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates. The liquid crystal display element manufactured through the process of arrange | positioning the liquid crystal aligning film containing this, and applying a voltage between electrodes is used preferably. Here, ultraviolet rays are suitable as the active energy ray.
In order to obtain a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat, a method of adding a compound containing this polymerizable group to a liquid crystal aligning agent, A method using a coalescing component may be mentioned. Since the liquid crystal aligning agent of the present invention contains a specific compound having a double bond site that reacts by irradiation with heat or ultraviolet rays, the alignment of liquid crystal molecules can be controlled by at least one of ultraviolet irradiation and heating. it can.

If an example of liquid crystal cell production is given, prepare a pair of substrates on which a liquid crystal alignment film is formed, spread spacers on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside, Examples include a method in which the other substrate is attached and liquid crystal is injected under reduced pressure and sealing is performed, and a method in which the substrate is attached and sealed after the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed.
After the liquid crystal cell is manufactured, the orientation of the liquid crystal molecules can be controlled by irradiating heat or ultraviolet rays while applying an AC or DC voltage to the liquid crystal cell.
As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention has excellent reliability and can be suitably used for a large-screen, high-definition liquid crystal television.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention should not be construed as being limited thereto. In addition, the symbol of the compound used by an Example and a comparative example is as follows.

(Tetracarboxylic dianhydride)
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BODA: bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride TCA: represented by the following formula Tetracarboxylic dianhydride TDA: tetracarboxylic dianhydride represented by the following formula

(Specific side chain diamine compounds)
PCH7DAB: 1,3-diamino-4- [4- (trans-4-n-heptylcyclohexyl) phenoxy] benzene PBCH5DAB: 1,3-diamino-4- {4- [trans-4- (trans-4 -N-pentylcyclohexyl) cyclohexyl] phenoxy} benzene m-PBCH5DABz: 1,3-diamino-5- {4- [4- (trans-4-n-pentylcyclohexyl) phenyl] phenoxymethyl} benzene

(Other diamine compounds)
p-PDA: p-phenylenediamine m-PDA: m-phenylenediamine DBA: 3,5-diaminobenzoic acid AP18: 1,3-diamino-4-octadecyloxybenzene ColDAB: diamine compound represented by the following formula

(Organic solvent)
NEP: N-ethyl-2-pyrrolidone NMP: N-methyl-2-pyrrolidone γ-BL: γ-butyrolactone BCS: ethylene glycol monobutyl ether ECS: ethylene glycol monoethyl ether MC: diethylene glycol monomethyl ether EC: diethylene glycol monoethyl ether PGME: Propylene glycol monomethyl ether

The physical properties of the polyimide precursor and polyimide, such as molecular weight and imidization rate, were measured or evaluated as follows.

(Measurement of molecular weight of polyimide precursor and polyimide)
The molecular weight of polyimide in the synthesis example is as follows using a normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko KK) and columns (KD-803, KD-805) (manufactured by Shodex). The measurement was performed as described above.
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additive, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L (liter), phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol) / L, 10 ml / L of tetrahydrofuran (THF))
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: (About 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory).

(Measurement of imidization rate)
The imidation ratio of polyimide in the synthesis example was measured as follows. 20 mg of polyimide powder is put into an NMR 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 dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring machine (JNW-ECA500, manufactured by JEOL Datum). The imidation rate is determined by determining a proton derived from a structure that does not change before and after imidation as a reference proton, the peak integrated value of this proton, and a proton peak derived from the NH group of amic acid that appears in the vicinity of 9.5 to 10.0 ppm. Using the integrated value, the following formula was used.
Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

[Synthesis of polyimide and polyimide acid]
<Synthesis Example 1>
CBDA (5.50 g, 28.0 mmol), PCH7DAB (3.20 g, 8.41 mmol), and p-PDA (2.13 g, 19.7 mmol) were mixed in NEP (32.5 g) at 40 ° C. Reaction was performed for 6 hours to obtain a polyamic acid solution (1) having a resin solid content concentration of 25.0% by mass. The number average molecular weight of this polyamic acid was 25,100, and the weight average molecular weight was 74,800.

<Synthesis Example 2>
BODA (10.2 g, 40.8 mmol), PCH7DAB (9.70 g, 25.5 mmol), and DBA (3.88 g, 25.5 mmol) were mixed in NEP (42.6 g) and at 80 ° C. for 5 hours. Reacted. Thereafter, CBDA (2.00 g, 10.2 mmol) and NEP (34.8 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (2) having a resin solid content concentration of 25.0 mass%. . The number average molecular weight of this polyamic acid was 24,200, and the weight average molecular weight was 64,000.

<Synthesis Example 3>
NEP was added to the polyamic acid solution (2) (90.0 g) having a resin solid concentration of 25.0% by mass obtained in Synthesis Example 2 and diluted to 6% by mass, and then acetic anhydride (11 .6 g) and pyridine (8.56 g) were added and reacted at 80 ° C. for 4 hours. This reaction solution was poured into methanol (1800 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (3). The imidation ratio of this polyimide was 57%, the number average molecular weight was 21,300, and the weight average molecular weight was 51,500.

<Synthesis Example 4>
BODA (6.89 g, 27.5 mmol), PBCH5DAB (5.21 g, 12.0 mmol), and DBA (3.42 g, 22.5 mmol) were mixed in NEP (28.1 g) and at 80 ° C. for 5 hours. Let it react. Thereafter, CBDA (1.35 g, 6.88 mmol) and NEP (22.4 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a resin solid content concentration of 25.0 mass%.
After adding NEP to the obtained polyamic acid solution (60.0 g) and diluting to 6% by mass, acetic anhydride (13.5 g) and pyridine (9.80 g) were added as an imidization catalyst, and Reacted for hours. This reaction solution was poured into methanol (1500 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (4). The imidation ratio of this polyimide was 79%, the number average molecular weight was 19,200, and the weight average molecular weight was 48,200.

<Synthesis Example 5>
BODA (5.95 g, 23.8 mmol), m-PBCH5DABz (4.56 g, 10.2 mmol), and p-PDA (2.57 g, 23.8 mmol) were mixed in NEP (25.0 g), and 80 The reaction was carried out at 5 ° C. for 5 hours. Thereafter, CBDA (2.00 g, 10.2 mmol) and NEP (20.3 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a resin solid content concentration of 25.0 mass%.
After adding NEP to the obtained polyamic acid solution (55.0 g) and diluting to 6% by mass, acetic anhydride (12.3 g) and pyridine (9.11 g) were added as imidization catalysts, and Reacted for hours. This reaction solution was poured into methanol (1500 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (5). The imidation ratio of this polyimide was 80%, the number average molecular weight was 21,500, and the weight average molecular weight was 53,800.

<Synthesis Example 6>
TCA (4.50 g, 20.1 mmol), PCH7DAB (2.29 g, 6.02 mmol), and m-PDA (1.52 g, 14.1 mmol) were mixed in NEP (24.9 g) at 40 ° C. The reaction was performed for 6 hours to obtain a polyamic acid solution (6) having a resin solid content concentration of 25.0% by mass. The number average molecular weight of this polyamic acid was 25,100, and the weight average molecular weight was 71,900.

<Synthesis Example 7>
TCA (7.25 g, 32.3 mmol), PBCH5DAB (4.20 g, 9.71 mmol), and DBA (3.44 g, 22.6 mmol) were mixed in NEP (44.7 g) and at 40 ° C. for 6 hours. The reaction was performed to obtain a polyamic acid solution having a resin solid content concentration of 25.0% by mass.
After adding NEP to the obtained polyamic acid solution (50.0 g) and diluting to 6% by mass, acetic anhydride (6.05 g) and pyridine (4.73 g) were added as imidization catalysts, Reacted for hours. This reaction solution was poured into methanol (900 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (7). The imidation ratio of this polyimide was 54%, the number average molecular weight was 21,800, and the weight average molecular weight was 56,200.

<Synthesis Example 8>
TDA (2.98 g, 9.92 mmol), PCH7DAB (3.78 g, 9.93 mmol), and DBA (3.53 g, 23.2 mmol) were mixed in NEP (24.5 g) and at 80 ° C. for 5 hours. Reacted. Thereafter, CBDA (4.55 g, 23.2 mmol) and NEP (20.1 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a resin solid content concentration of 25.0 mass%.
NEP was added to the obtained polyamic acid solution (50.0 g), diluted to 6% by mass, acetic anhydride (11.1 g) and pyridine (8.05 g) were added as an imidization catalyst, and 3 ° C. was added at 90 ° C. Reacted for hours. This reaction solution was poured into methanol (1500 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (8). The imidation ratio of this polyimide was 76%, the number average molecular weight was 20,700, and the weight average molecular weight was 52,500.

<Synthesis Example 9>
TDA (3.29 g, 11.0 mmol), PBCH5DAB (4.74 g, 11.0 mmol), and p-PDA (2.76 g, 25.5 mmol) were mixed in NEP (26.1 g) at 80 ° C. The reaction was allowed for 5 hours. Thereafter, CBDA (5.01 g, 25.5 mmol) and NEP (21.3 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a resin solid content concentration of 25.0 mass%.
After adding NEP to the obtained polyamic acid solution (50.5 g) and diluting to 6% by mass, acetic anhydride (11.2 g) and pyridine (8.21 g) were added as an imidization catalyst, and Reacted for hours. This reaction solution was poured into methanol (1500 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (9). The imidation ratio of this polyimide was 80%, the number average molecular weight was 20,100, and the weight average molecular weight was 50,200.

<Synthesis Example 10>
TDA (3.05 g, 10.2 mmol), m-PBCH5DABz (4.54 g, 10.2 mmol), and DBA (3.61 g, 23.7 mmol) were mixed in NEP (26.2 g) at 80 ° C. The reaction was performed for 5 hours. Thereafter, CBDA (4.65 g, 23.7 mmol) and NEP (21.4 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution having a resin solid content concentration of 25.0 mass%.
After adding NEP to the obtained polyamic acid solution (50.0 g) and diluting to 6% by mass, acetic anhydride (11.2 g) and pyridine (8.24 g) were added as imidization catalysts, and Reacted for hours. This reaction solution was poured into methanol (1500 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (10). The imidation ratio of this polyimide was 80%, the number average molecular weight was 20,500, and the weight average molecular weight was 52,900.

<Synthesis Example 11>
BODA (5.21 g, 20.8 mmol), PCH7DAB (4.95 g, 13.0 mmol), and DBA (1.98 g, 13.0 mmol) were mixed in NMP (21.7 g) and at 80 ° C. for 5 hours. Reacted. Thereafter, CBDA (1.02 g, 5.20 mmol) and NMP (17.8 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (11) having a resin solid content concentration of 25.0 mass%. . The number average molecular weight of this polyamic acid was 25,100, and the weight average molecular weight was 65,900.

<Synthesis Example 12>
BODA (6.38 g, 25.5 mmol), AP18 (6.00 g, 15.9 mmol), and DBA (2.45 g, 16.1 mmol) were mixed in NMP (26.5 g) and at 80 ° C. for 5 hours. Reacted. Thereafter, CBDA (1.25 g, 6.37 mmol) and NMP (21.7 g) were added and reacted at 40 ° C. for 6 hours to obtain a polyamic acid solution (12) having a resin solid content concentration of 25.0 mass%. . The number average molecular weight of this polyamic acid was 18,900, and the weight average molecular weight was 54,800.

<Synthesis Example 13>
NMP was added to the polyamic acid solution (12) (50.0 g) having a resin solid concentration of 25.0% by mass obtained in Synthesis Example 12 and diluted to 6% by mass, and then acetic anhydride (6 .23 g) and pyridine (4.65 g) were added and reacted at 80 ° C. for 4 hours. This reaction solution was poured into methanol (1000 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (13). The imidation ratio of this polyimide was 58%, the number average molecular weight was 16,900, and the weight average molecular weight was 43,800.

<Synthesis Example 14>
BODA (6.89 g, 27.5 mmol), ColDAB (5.40 g, 10.3 mmol), and DBA (3.68 g, 24.2 mmol) were mixed in NEP (28.6 g) and 5.80 ° C. The reaction was allowed for 5 hours. Thereafter, CBDA (1.35 g, 6.88 mmol) and NEP (23.4 g) were added and reacted at 40 ° C. for 7 hours to obtain a polyamic acid solution (14) having a resin solid content concentration of 25.0 mass%. . The number average molecular weight of this polyamic acid was 20,100, and the weight average molecular weight was 59,800.

<Synthesis Example 15>
BODA (6.74 g, 26.9 mmol), ColDAB (5.28 g, 10.1 mmol), and DBA (3.60 g, 23.7 mmol) were mixed in NMP (27.9 g) and 5.80 ° C. The reaction was performed for 5 hours. Thereafter, CBDA (1.32 g, 6.73 mmol) and NMP (22.9 g) were added and reacted at 40 ° C. for 7 hours to obtain a polyamic acid solution (15) having a resin solid content concentration of 25.0 mass%. . The number average molecular weight of this polyamic acid was 19,900, and the weight average molecular weight was 59,100.

<Synthesis Example 16>
NMP was added to the polyamic acid solution (15) (55.0 g) having a resin solid concentration of 25.0% by mass obtained in Synthesis Example 15 and diluted to 6% by mass, and then acetic anhydride (6 .81 g) and pyridine (5.07 g) were added and reacted at 80 ° C. for 4 hours. This reaction solution was poured into methanol (1100 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (16). The imidation ratio of this polyimide was 57%, the number average molecular weight was 15,900, and the weight average molecular weight was 45,100.
Table 4 summarizes the polyamic acid and polyimide of the present invention.

* 1: All are polyamic acids and imidation ratio is not measured.

[Preparation of liquid crystal alignment treatment agent]
The following Examples 1 to 34 and Comparative Examples 1 to 12 are preparation examples of the liquid crystal aligning agent, and all are for evaluation of the liquid crystal aligning agent.
Using the liquid crystal alignment treatment agents obtained in the examples and comparative examples, “printability evaluation of liquid crystal alignment treatment agent”, “inkjet applicability evaluation of liquid crystal alignment treatment agent”, “production of liquid crystal cell (normal cell)”, “Evaluation of liquid crystal alignment and pretilt angle (normal cell)”, “Preparation of liquid crystal cell (PSA cell)”, and “Evaluation of liquid crystal alignment (PSA cell)” were performed.

(Evaluation of printability of liquid crystal alignment treatment agent)
Printability evaluation was performed using the liquid crystal aligning agent obtained by the Example and the comparative example. A simple printer S15 type (manufactured by Nissha Printing Co., Ltd.) was used as the printer. For printing, the printed area is 80 mm x 80 mm, the printing pressure is 0.2 mm, the number of discarded substrates is 5 sheets, the time from printing to temporary drying is 90 seconds, and temporary drying is performed on a hot plate. The test was carried out at 70 ° C. for 5 minutes.
The pinhole of the obtained coating film was evaluated, the linearity of the liquid crystal alignment film end was evaluated, and the rise of the liquid crystal alignment film end was evaluated.

The pinhole was evaluated by visually observing the coating film under a sodium lamp. Specifically, the number of pinholes confirmed on the liquid crystal alignment film was counted, and the smaller the number of pinholes, the better the coatability.

Evaluation of the linearity of the edge part of a liquid crystal aligning film was performed by observing the coating film of a right side edge part with respect to a printing direction with an optical microscope (the Nikon company make, ECLIPSE E600WPOL). Specifically, the observation was performed with an optical microscope at a magnification of 25 times, and the difference between 3 and 4 in FIG. 1, which was the obtained coating film image, that is, the length of A in FIG. 1 was measured. All coating images were obtained at the same magnification. The shorter the length of A, the better the linearity of the end portion of the liquid crystal alignment film.

Evaluation of the bulge of the edge part of a liquid crystal aligning film was performed by observing the coating film of the right edge part with an optical microscope with respect to the printing direction. Specifically, observation was performed with an optical microscope at a magnification of 25 times, and the length of B in the obtained coating film image (FIG. 2) was measured. All coating images were obtained at the same magnification. The shorter the length of B, the better the bulge 5 at the end of the liquid crystal alignment film.
Tables 8 to 10 show the number of pinholes, the length of A, and the length of B of the liquid crystal alignment films obtained in Examples and Comparative Examples.

(Evaluation of ink jet coatability of liquid crystal alignment treatment agent)
Using the liquid crystal aligning agent (7) obtained in Example 7 and the liquid crystal aligning agent (12) obtained in Example 12, inkjet applicability evaluation was performed. As the ink jet coater, HIS-200 (manufactured by Hitachi Plant Technology) was used. Application is on a cleaned ITO (indium tin oxide) vapor deposition substrate, the application area is 70 mm x 70 mm, the nozzle pitch is 0.423 mm, the scan pitch is 0.5 mm, the application speed is 40 mm / second, from application to temporary drying. The time was 60 seconds, and temporary drying was performed on a hot plate at 70 ° C. for 5 minutes.
The pinhole of the obtained coating film was evaluated under the same conditions as in “Evaluation of Printability of Liquid Crystal Alignment Agent”. Table 8 shows the pinhole evaluation results in Examples 7 and 12.

(Production of liquid crystal cell (normal cell))
The liquid crystal alignment treatment agents obtained in the examples and comparative examples were spin-coated on the ITO surface of a 30 mm × 40 mm ITO electrode substrate, and heated on a hot plate at 80 ° C. for 5 minutes in a thermal circulation clean oven. Heat treatment was performed at 220 ° C. for 30 minutes to obtain an ITO substrate with a polyimide liquid crystal alignment film having a film thickness of 100 nm. The coated surface of the ITO substrate was rubbed using a rayon cloth with a rubbing apparatus having a roll diameter of 120 mm under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.1 mm. .
Two ITO substrates with the obtained liquid crystal alignment film were prepared, combined with a 6 μm spacer sandwiched with the liquid crystal alignment film surface on the inside, and the periphery was adhered with a sealant to produce an empty cell. MLC-6608 (manufactured by Merck Japan) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell (ordinary cell).

(Evaluation of liquid crystal orientation and pretilt angle (normal cell))
Using the liquid crystal cell obtained above, the liquid crystal orientation and the pretilt angle were evaluated. The liquid crystal alignment was confirmed by observing the liquid crystal cell with a polarizing microscope (Nikon Corporation, ECLIPSE E600WPOL) to check for alignment defects.
The pretilt angle was measured after heat treatment at 95 ° C. for 5 minutes after liquid crystal injection, and further at 120 ° C. for 5 hours. Furthermore, after injecting the liquid crystal, the pretilt angle was measured after irradiating the liquid crystal cell heated at 95 ° C. for 5 minutes with ultraviolet rays of 10 J / cm ^{2 in} terms of 365 nm.
The smaller the change in the pretilt angle after the heat treatment at 120 ° C for 5 hours or after the ultraviolet irradiation, the more stable the pretilt angle against heat or ultraviolet light after the heat treatment at 95 ° C for 5 minutes. It was decided that it was high.
The pretilt angle was measured at room temperature using PAS-301 (manufactured by ELSICON). Furthermore, ultraviolet irradiation was performed using a tabletop UV curing device (HCT3B28HEX-1) (manufactured by Senlite).
Tables 11 to 13 show the results of liquid crystal alignment and pretilt angles of the liquid crystal cells obtained in the examples and comparative examples.

(Preparation of liquid crystal cell (PSA cell))
Liquid crystal alignment treatment agent (5) obtained in Example 5, liquid crystal alignment treatment agent (6) obtained in Example 6, liquid crystal alignment treatment agent (11) obtained in Example 11, obtained in Example 17 The liquid crystal aligning agent (17) obtained and the liquid crystal aligning agent (30) obtained in Example 30 were placed in the center with a substrate with ITO electrodes having a pattern spacing of 20 μm of 10 mm × 10 mm and an ITO electrode having a center of 10 mm × 40 mm. Spin coat the ITO surface of the attached substrate and heat-treat on a hot plate at 80 ° C. for 5 minutes and in a heat circulating clean oven at 220 ° C. for 30 minutes to obtain a polyimide coating film with a film thickness of 100 nm. It was. The coating surface was washed with pure water, and then heat-treated at 100 ° C. for 15 minutes in a heat-circulating clean oven to obtain a substrate with a liquid crystal alignment film.
This substrate with a liquid crystal alignment film was combined with a liquid crystal alignment film surface inside, with a 6 μm spacer in between, and the periphery was adhered with a sealant to produce an empty cell. A polymerizable compound (1) represented by the following formula was added to MLC-6608 (manufactured by Merck Japan Co., Ltd.) by a reduced pressure injection method into this empty cell, and the polymerizable compound was added to 100% by mass of MLC-6608. A liquid crystal cell was obtained by injecting liquid crystal mixed by 3% by mass and sealing the injection port.

While applying an AC voltage of 5 V to the obtained liquid crystal cell, using a metal halide lamp with an illuminance of 60 mW, the wavelength of 350 nm or less was cut, and ultraviolet irradiation of 20 J / cm ^{2 in} terms of 365 nm was performed, and the alignment direction of the liquid crystal A liquid crystal cell (PSA cell) was controlled. The temperature in the irradiation apparatus when the liquid crystal cell was irradiated with ultraviolet rays was 50 ° C.

(Evaluation of liquid crystal alignment (PSA cell))
The response speed of the liquid crystal before and after ultraviolet irradiation of the obtained liquid crystal cell was measured. As the response speed, T90 → T10 from 90% transmittance to 10% transmittance was measured. The PSA cells obtained in the examples and comparative examples have a higher response speed of the liquid crystal cell after ultraviolet irradiation than that of the liquid crystal cell before ultraviolet irradiation. confirmed.
Moreover, in any liquid crystal cell, it was confirmed by polarizing microscope observation that the liquid crystal was uniformly aligned.

Examples 1 to 34 and Comparative Examples 1 to 12 will be described in detail below. The conditions for preparing the liquid crystal aligning agent in each example are summarized in Tables 5 to 7.
In addition, using the liquid crystal alignment treatment agents obtained in Examples 1 to 34 and Comparative Examples 1 to 12, “liquid crystal alignment treatment agent printability evaluation”, “liquid crystal alignment treatment agent inkjet applicability evaluation”, “liquid crystal “Manufacture of cell (normal cell)”, “Evaluation of liquid crystal alignment and pretilt angle (normal cell)”, “Preparation of liquid crystal cell (PSA cell)”, “Evaluation of liquid crystal alignment (PSA cell)”, etc. . The results are summarized in Tables 8-13.

<Example 1>
NEP (32.0 g) was added to the polyamic acid solution (1) (10.1 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 1, and the mixture was stirred at 25 ° C. for 2 hours to perform liquid crystal alignment treatment. Agent (1) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (1), production of cells and various evaluations were performed under the above-described conditions.

<Example 2>
NEP (12.1 g), BCS (11.8 g) and EC (7.84 g) were added to the polyamic acid solution (1) (10.0 g) having a resin solid content concentration of 25.0 mass% obtained in Synthesis Example 1. In addition, the liquid crystal aligning agent (2) was obtained by stirring at 25 ° C. for 2 hours. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (2), cell preparation and various evaluations were performed under the above-described conditions.

<Example 3>
NEP (31.7 g) was added to the polyamic acid solution (2) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 2, and the mixture was stirred at 25 ° C. for 2 hours to perform liquid crystal alignment treatment. Agent (3) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (3), cell preparation and various evaluations were performed under the above-described conditions.

<Example 4>
NEP (14.0 g) and BCS (17.6 g) were added to the polyamic acid solution (2) (10.0 g) having a resin solid content concentration of 25.0 mass% obtained in Synthesis Example 2, and 2 at 25 ° C. The liquid crystal aligning agent (4) was obtained by stirring for a period of time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (4), cell preparation and various evaluations were performed under the above-described conditions.

<Example 5>
NEP (40.0 g) was added to the polyimide powder (3) (2.55 g) obtained in Synthesis Example 3, and the mixture was stirred at 70 ° C. for 24 hours to obtain a liquid crystal aligning agent (5). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (5), cell preparation and various evaluations were performed under the above-described conditions.

<Example 6>
NEP (14.6 g) was added to the polyimide powder (3) (2.54 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NEP (7.30g) and BCS (17.9g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (6). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (6), production of cells and various evaluations were performed under the above-described conditions.

<Example 7>
NEP (29.7 g) was added to the polyimide powder (3) (2.50 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NEP (14.8g) and BCS (36.4g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (7). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (7), “evaluation of ink jet coatability of liquid crystal aligning agent” was performed under the above-described conditions.

<Example 8>
NEP (17.3 g) was added to the polyimide powder (3) (2.55 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NEP (8.71 g), BCS (8.01 g) and MC (6.00 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (8). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (8), cell preparation and various evaluations were performed under the above-described conditions.

<Example 9>
NEP (18.7 g) was added to the polyimide powder (3) (2.56 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NEP (9.40 g), BCS (6.00 g) and EC (6.00 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (9). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (9), cell preparation and various evaluations were performed under the above-described conditions.

<Example 10>
NEP (17.3 g) was added to the polyimide powder (3) (2.55 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NEP (8.70g) and PGME (14.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (10). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (10), cell preparation and various evaluations were performed under the above-described conditions.

<Example 11>
NEP (16.0 g) was added to the polyimide powder (3) (2.55 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NMP (6.02g) and BCS (18.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (11). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (11), production of cells and various evaluations were performed under the above-described conditions.

<Example 12>
NEP (27.6 g) was added to the polyimide powder (3) (2.50 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. NMP (10.3g) and BCS (31.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (12). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (12), “evaluation of ink-jet coating property of liquid crystal aligning agent” was performed under the above-described conditions.

<Example 13>
NEP (16.0 g) was added to the polyimide powder (3) (2.55 g) obtained in Synthesis Example 3, and dissolved by stirring at 70 ° C. for 24 hours. To this solution, γ-BL (4.02 g) and BCS (20.0 g) were added and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (13). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (13), a cell was prepared and various evaluations were performed under the above-described conditions.

<Example 14>
NEP (12.0 g) was added to the polyimide powder (4) (2.55 g) obtained in Synthesis Example 4 and dissolved by stirring at 70 ° C. for 24 hours. NEP (6.02g) and BCS (22.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (14). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (14), cell preparation and various evaluations were performed under the above-described conditions.

<Example 15>
NEP (16.1 g) was added to the polyimide powder (4) (2.57 g) obtained in Synthesis Example 4, and dissolved by stirring at 70 ° C. for 24 hours. NEP (8.10g) and ECS (16.1g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (15). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (15), a cell was prepared and various evaluations were performed under the above-described conditions.

<Example 16>
NEP (18.5 g) was added to the polyimide powder (4) (2.53 g) obtained in Synthesis Example 4 and dissolved by stirring at 70 ° C. for 24 hours. NEP (9.20 g), BCS (7.93 g) and MC (3.97 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (16). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (16), cell preparation and various evaluations were performed under the above-described conditions.

<Example 17>
NEP (16.0 g) was added to the polyimide powder (4) (2.55 g) obtained in Synthesis Example 4 and dissolved by stirring at 70 ° C. for 24 hours. NMP (10.0g) and BCS (14.1g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (17). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (17), cell preparation and various evaluations were performed under the above-described conditions.

<Example 18>
NEP (20.0 g) was added to the polyimide powder (4) (2.55 g) obtained in Synthesis Example 4 and dissolved by stirring at 70 ° C. for 24 hours. Γ-BL (4.00 g) and BCS (16.0 g) were added to this solution and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (18). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (18), production of cells and various evaluations were performed under the above-described conditions.

<Example 19>
NEP (12.5 g) was added to the polyimide powder (5) (2.55 g) obtained in Synthesis Example 5, and dissolved by stirring at 70 ° C. for 24 hours. NEP (3.54g) and BCS (24.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (19). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (19), cell preparation and various evaluations were performed under the above-described conditions.

<Example 20>
NEP (13.4 g) was added to the polyimide powder (5) (2.56 g) obtained in Synthesis Example 5, and dissolved by stirring at 70 ° C. for 24 hours. NEP (6.70 g), BCS (16.1 g) and MC (4.02 g) were added to this solution and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (20). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (20), cell preparation and various evaluations were performed under the above-described conditions.

<Example 21>
NEP (12.0 g) was added to the polyimide powder (5) (2.55 g) obtained in Synthesis Example 5, and dissolved by stirring at 70 ° C. for 24 hours. NMP (10.0g) and BCS (18.1g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (21). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (21), cell preparation and various evaluations were performed under the above-described conditions.

<Example 22>
NEP (17.8 g) was added to the polyimide powder (5) (2.55 g) obtained in Synthesis Example 5, and dissolved by stirring at 70 ° C. for 24 hours. Γ-BL (2.00 g) and BCS (20.0 g) were added to this solution and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (22). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (22), cell preparation and various evaluations were performed under the above-described conditions.

<Example 23>
NEP (6.21 g) and BCS (25.5 g) were added to the polyamic acid solution (6) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 6, and 2 at 25 ° C. The liquid crystal aligning agent (23) was obtained by stirring for a time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (23), cell preparation and various evaluations were performed under the above-described conditions.

<Example 24>
NEP (16.0 g), BCS (7.87 g) and PGME (7.84 g) were added to the polyamic acid solution (6) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 6. In addition, the mixture was stirred at 25 ° C. for 2 hours to obtain a liquid crystal aligning agent (24). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (24), cell preparation and various evaluations were performed under the above-described conditions.

<Example 25>
NEP (15.9 g) was added to the polyimide powder (7) (2.54 g) obtained in Synthesis Example 7 and dissolved by stirring at 70 ° C. for 24 hours. NEP (8.00g) and ECS (15.9g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (25). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (25), cell preparation and various evaluations were performed under the above-described conditions.

<Example 26>
NEP (17.3 g) was added to the polyimide powder (7) (2.55 g) obtained in Synthesis Example 7 and dissolved by stirring at 70 ° C. for 24 hours. NEP (8.71 g), BCS (8.01 g) and PGME (6.00 g) were added to this solution and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (26). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (26), cell preparation and various evaluations were performed under the above-described conditions.

<Example 27>
NEP (20.0 g) was added to the polyimide powder (7) (2.55 g) obtained in Synthesis Example 7 and dissolved by stirring at 70 ° C. for 24 hours. NMP (8.00 g), BCS (10.1 g) and EC (2.02 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (27). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (27), cell preparation and various evaluations were performed under the above-described conditions.

<Example 28>
NEP (18.1 g) was added to the polyimide powder (7) (2.55 g) obtained in Synthesis Example 7 and dissolved by stirring at 70 ° C. for 24 hours. To this solution, γ-BL (2.00 g), BCS (12.0 g) and ECS (8.00 g) were added, followed by stirring at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (28). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (28), cell preparation and various evaluations were performed under the above-described conditions.

<Example 29>
NEP (21.3 g) was added to the polyimide powder (8) (2.55 g) obtained in Synthesis Example 8, and dissolved by stirring at 70 ° C. for 24 hours. NEP (10.7g) and BCS (8.01g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (29). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (29), cell preparation and various evaluations were performed under the above-described conditions.

<Example 30>
NEP (26.1 g) was added to the polyimide powder (8) (2.56 g) obtained in Synthesis Example 8, and dissolved by stirring at 70 ° C. for 24 hours. NMP (8.00 g), BCS (4.00 g) and MC (2.00 g) were added to this solution and stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (30). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (30), cell preparation and various evaluations were performed under the above-described conditions.

<Example 31>
NEP (16.0 g) was added to the polyimide powder (9) (2.55 g) obtained in Synthesis Example 9, and dissolved by stirring at 70 ° C. for 24 hours. NMP (12.0 g) and BCS (12.1 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (31). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (31), cell preparation and various evaluations were performed under the above-described conditions.

<Example 32>
NEP (20.0 g) was added to the polyimide powder (9) (2.55 g) obtained in Synthesis Example 9 and dissolved by stirring at 70 ° C. for 24 hours. Γ-BL (4.00 g) and BCS (15.8 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (32). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (32), cell preparation and various evaluations were performed under the above-described conditions.

<Example 33>
NEP (32.2 g) was added to the polyimide powder (10) (2.55 g) obtained in Synthesis Example 10, and dissolved by stirring at 70 ° C. for 24 hours. NMP (4.00 g), BCS (2.00 g) and EC (2.00 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (33). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (33), cell preparation and various evaluations were performed under the above-described conditions.

<Example 34>
NEP (16.0 g) was added to the polyimide powder (10) (2.55 g) obtained in Synthesis Example 10, and dissolved by stirring at 70 ° C. for 24 hours. Γ-BL (2.01 g), BCS (16.0 g) and MC (6.00 g) were added to this solution, and the mixture was stirred at 50 ° C. for 10 hours to obtain a liquid crystal aligning agent (34). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (34), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 1>
NMP (14.5 g) was added to the polyimide powder (3) (2.52 g) obtained in Synthesis Example 3 and dissolved by stirring at 70 ° C. for 24 hours. NMP (7.21g) and BCS (17.8g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (35). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (35), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative example 2>
NMP (32.0 g) was added to the polyamic acid solution (11) (10.1 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 11, and the mixture was stirred at 25 ° C. for 2 hours for liquid crystal alignment treatment. Agent (36) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (36), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 3>
NMP (14.0 g) and BCS (17.6 g) were added to the polyamic acid solution (11) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 11, and 2 at 25 ° C. The liquid crystal aligning agent (37) was obtained by stirring for a time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (37), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 4>
NMP (14.0 g) and BCS (17.4 g) were added to the polyamic acid solution (12) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 12, and 2 at 25 ° C. The liquid crystal aligning agent (38) was obtained by stirring for a time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (38), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 5>
NMP (14.7 g) was added to the polyimide powder (13) (2.55 g) obtained in Synthesis Example 13 and dissolved by stirring at 70 ° C. for 24 hours. NMP (7.28g) and BCS (18.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (39). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (39), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 6>
NEP (14.7 g) was added to the polyimide powder (13) (2.55 g) obtained in Synthesis Example 13 and dissolved by stirring at 70 ° C. for 24 hours. NEP (7.30g) and BCS (18.0g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (40). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (40), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 7>
NEP (31.7 g) was added to the polyamic acid solution (14) (10.0 g) with a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 14, and the mixture was stirred at 25 ° C. for 2 hours to conduct liquid crystal alignment treatment. Agent (41) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (41), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 8>
NEP (14.1 g) and BCS (17.6 g) were added to the polyamic acid solution (14) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 14, and 2 at 25 ° C. The liquid crystal aligning agent (42) was obtained by stirring for a period of time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (42), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 9>
NMP (31.7 g) was added to the polyamic acid solution (15) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 15, and the mixture was stirred at 25 ° C. for 2 hours to conduct liquid crystal alignment treatment. Agent (43) was obtained. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (43), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 10>
NMP (14.0 g) and BCS (17.6 g) were added to the polyamic acid solution (15) (10.0 g) having a resin solid content concentration of 25.0% by mass obtained in Synthesis Example 15, and 2 at 25 ° C. The liquid crystal aligning agent (44) was obtained by stirring for the time. This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (44), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 11>
NMP (14.7 g) was added to the polyimide powder (16) (2.55 g) obtained in Synthesis Example 16, and dissolved by stirring at 70 ° C. for 24 hours. NMP (7.30g) and BCS (18.2g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (45). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (45), cell preparation and various evaluations were performed under the above-described conditions.

<Comparative Example 12>
NEP (14.5 g) was added to the polyimide powder (16) (2.52 g) obtained in Synthesis Example 16, and dissolved by stirring at 70 ° C. for 24 hours. NEP (7.21g) and BCS (17.8g) were added to this solution, and it stirred at 50 degreeC for 10 hours, and obtained the liquid-crystal aligning agent (46). This liquid crystal aligning agent was confirmed to be a uniform solution without any abnormality such as turbidity or precipitation.
Using the obtained liquid crystal aligning agent (46), cell preparation and various evaluations were performed under the above-described conditions.

* 1: Ratio of the polymer in the liquid crystal aligning agent.

* 2: Ratio of the polymer in the liquid crystal aligning agent.

* 3: Ratio of the polymer in the liquid crystal aligning agent.

* 4: Ten or more alignment defects due to pinholes were observed.

As can be seen from the above results, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the example was exposed to high temperature and light irradiation for a longer time than the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the comparative example. However, a liquid crystal alignment film with a small change in pretilt angle can be obtained.
Furthermore, the liquid crystal aligning agent of an Example can obtain the liquid crystal aligning film with the small change of the said pretilt angle, and can obtain uniform coating property.

In addition, in the same polyamic acid or polyimide, in the comparison of the example containing the specific solvent of the present invention and the comparative example not containing the specific solvent, in the comparative example not containing the specific solvent, although the change in the pretilt angle is small, Many pinholes are generated, and the coating uniformity at the edge of the liquid crystal alignment film is poor. Specifically, it can be confirmed from the comparison between Example 3 and Comparative Example 2, the comparison between Example 4 and Comparative Example 3, and the comparison between Example 6 and Comparative Example 1.

Furthermore, in the comparison of the example using the diamine compound containing the specific side chain structure of the present invention and the comparative example using the diamine compound not containing the specific side chain structure, the diamine compound not containing the specific side chain structure was used. In the comparative example, the change in the pretilt angle is large, many pinholes are generated, and the coating film uniformity at the end of the liquid crystal alignment film is poor. Specifically, it can be confirmed from a comparison between Example 4 and Comparative Example 4, a comparison between Example 4 and Comparative Example 5, and a comparison between Example 4 and Comparative Example 6. In particular, in Comparative Example 6, although a specific solvent is used, many pinholes are generated, and the coating film uniformity at the end of the liquid crystal alignment film is poor.

Moreover, in the comparison with the Example using the diamine compound containing the specific side chain structure of this invention and the comparative example using the diamine compound which does not contain the specific side chain structure, the diamine compound which does not contain the specific side chain structure was used. In the comparative example, although the change in the pretilt angle is small, many pinholes are generated, and the coating film uniformity at the liquid crystal alignment film edge is poor. Specifically, comparison between Example 3 and Comparative Example 7, comparison between Example 3 and Comparative Example 9, comparison between Example 4 and Comparative Example 8, comparison between Example 4 and Comparative Example 10, and implementation This can be confirmed from the comparison between Example 4 and Comparative Example 11 and the comparison between Example 4 and Comparative Example 12.
In particular, in Comparative Example 7, Comparative Example 8 and Comparative Example 12, although a specific solvent is used, many pinholes are generated and the coating film uniformity at the end of the liquid crystal alignment film is poor.

The liquid crystal alignment treatment agent of the present invention has high wettability of the coating solution to the substrate, uniform coating properties, and the pretilt angle does not change even when exposed to high temperature and light irradiation for a long time. It is possible to provide a liquid crystal alignment film having excellent coating properties at the edges, and a liquid crystal display element having such a liquid crystal alignment film is excellent in reliability and suitable for a large-screen, high-definition liquid crystal television. And is particularly useful for vertical alignment type liquid crystal display elements such as TN elements, STN elements, and TFT liquid crystal elements.

It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2011-196320 filed on September 8, 2011 is cited here as the disclosure of the specification of the present invention. Incorporated.

DESCRIPTION OF SYMBOLS 1 Liquid crystal aligning film 2 Chromium vapor deposition board | substrate 3 End part of liquid crystal aligning film 4 End part of liquid crystal aligning film 5 Swelling of end part of liquid crystal aligning film

Claims

The liquid crystal aligning agent characterized by containing the following component (A) and component (B).
Component (A): N-ethyl-2-pyrrolidone.
Component (B): At least one polymer selected from the group consisting of a polyimide precursor having a side chain represented by the following formula [1] and a polyimide obtained by imidizing the polyimide precursor.

(In the formula [1], X 1 is a single bond, — (CH 2 ) a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH 3 ) —, —CONH. —, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON (CH 3 ) — or —N (CH 3 ) CO—, X 2 is a single bond or (CH 2 ) b -(B is an integer of 1 to 15.) X 3 is a single bond,-(CH 2 ) c- (c is an integer of 1 to 10), -O-, -NH-, -N X 4 is (CH 3 ) —, —CONH—, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON (CH 3 ) — or —N (CH 3 ) CO—. A divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring (an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, carbon 1-3 alkoxyl group, a fluorine-containing alkyl group having 1 to 3 carbon atoms, .X 5 benzene rings and may be substituted with a fluorine-containing alkoxyl group or a fluorine atom having 1 to 3 carbon atoms), cyclohexyl ring And a divalent cyclic group selected from heterocyclic rings (any hydrogen atom on these cyclic groups contains an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or fluorine having 1 to 3 carbon atoms) X 6 represents an alkyl group having 1 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, or an alkyl group, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms, or a fluorine atom. A C 1-18 alkoxyl group or a C 1-18 fluorine-containing alkoxyl group, and n is an integer of 0-4.)
The component (B) is at least selected from the group consisting of a polyimide precursor obtained by using a diamine having a side chain represented by the formula [1] as a part of a raw material diamine component and a polyimide obtained by imidizing the polyimide precursor. The liquid-crystal aligning agent of Claim 1 which is 1 type of polymers.
The liquid crystal aligning agent according to claim 2, wherein the diamine having a side chain represented by the formula [1] is a diamine compound represented by the following formula [1a].

(In the formula [1a], X 1 is a single bond, — (CH 2 ) a — (a is an integer of 1 to 15), —O—, —NH—, —N (CH 3 ) —, —CONH —, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON (CH 3 ) — or —N (CH 3 ) CO—, X 2 is a single bond or (CH 2 ) b -(B is an integer of 1 to 15.) X 3 is a single bond,-(CH 2 ) c- (c is an integer of 1 to 10), -O-, -NH-, -N X 4 is (CH 3 ) —, —CONH—, —NHCO—, —CH 2 O—, —COO—, —OCO—, —CON (CH 3 ) — or —N (CH 3 ) CO—. A divalent cyclic group selected from a benzene ring, a cyclohexyl ring and a heterocyclic ring (any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, carbon C 1-3 alkoxyl group, a fluorine-containing alkyl group having 1 to 3 carbon atoms, .X 5 benzene rings and may be substituted with a fluorine-containing alkoxyl group or a fluorine atom having 1 to 3 carbon atoms), cyclohexyl A divalent cyclic group selected from a ring and a heterocyclic ring (an arbitrary hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or fluorine having 1 to 3 carbon atoms) X 6 represents an alkyl group having 1 to 18 carbon atoms, or a fluorine-containing alkyl group having 1 to 18 carbon atoms, which may be substituted with a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom. And an alkoxyl group having 1 to 18 carbon atoms or a fluorine-containing alkoxyl group having 1 to 18 carbon atoms, n is an integer of 0 to 4, and m is an integer of 1 to 4.)
The liquid crystal aligning agent according to claim 3, wherein the diamine represented by the formula [1a] is used in an amount of 5 to 80 mol% of a diamine component as a raw material.
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the component (B) is a polymer using a tetracarboxylic dianhydride represented by the following formula [2].

(In Formula [2], Y 1 is a tetravalent organic group having 4 to 13 carbon atoms and contains a non-aromatic cyclic hydrocarbon group having 4 to 10 carbon atoms).
6. The liquid crystal aligning agent according to claim 5, wherein Y 1 is a group having a structure represented by the following formulas [2a] to [2j].

(In Formula [2a], Y 2 to Y 5 are a hydrogen atom, a methyl group, a chlorine atom or a benzene ring, and may be the same or different. In Formula [2g], Y 6 and Y 7 is a hydrogen atom or a methyl group, which may be the same or different.
The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the polymer as the component (B) is a polyamic acid.
The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the polymer as the component (B) is a polyimide obtained by dehydrating and ring-closing polyamic acid.
The liquid crystal aligning agent according to any one of claims 1 to 8, which contains N-methyl-2-pyrrolidone or γ-butyrolactone as component (C).
As component (D), 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl 10. The liquid crystal aligning agent according to claim 1, comprising at least one selected from the group consisting of ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monobutyl ether. .
The liquid crystal aligning agent according to any one of claims 1 to 10, wherein the component (A) is 10 to 100% by mass of the whole organic solvent contained in the liquid crystal aligning agent.
The liquid crystal aligning agent according to any one of claims 9 to 11, wherein the component (C) is 0.1 to 70% by mass of the whole organic solvent contained in the liquid crystal aligning agent.
The liquid crystal aligning agent according to any one of claims 10 to 12, wherein the component (D) is 5 to 80% by mass of the whole organic solvent contained in the liquid crystal aligning agent.
The liquid crystal aligning agent according to any one of claims 1 to 13, wherein the component (B) in the liquid crystal aligning agent is 0.1 to 15% by mass.
A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of claims 1 to 14.
A liquid crystal alignment film obtained by an ink jet method using the liquid crystal alignment treatment agent according to any one of claims 1 to 14.
A liquid crystal display element having the liquid crystal alignment film according to claim 15 or 16.
A liquid crystal composition comprising a liquid crystal layer between a pair of substrates provided with electrodes and comprising a polymerizable compound that is polymerized by at least one of active energy rays and heat is disposed between the pair of substrates, and the electrodes The liquid crystal aligning film of Claim 15 or 16 used for the liquid crystal display element manufactured through the process of superposing | polymerizing the said polymeric compound, applying a voltage in between.
A liquid crystal display element having the liquid crystal alignment film according to claim 18.
A liquid crystal composition comprising a polymerizable compound having a liquid crystal layer between a pair of substrates provided with an electrode and the liquid crystal alignment film and polymerized between at least one of active energy rays and heat between the pair of substrates. The liquid crystal display element according to claim 19, wherein the liquid crystal display element is manufactured through a step of polymerizing the polymerizable compound while applying a voltage between the electrodes.
A liquid crystal layer between a pair of substrates provided with electrodes, and a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates; The liquid crystal aligning film of Claim 15 or 16 used for the liquid crystal display element manufactured through the process of superposing | polymerizing the said polymeric group, applying a voltage in between.
A liquid crystal display element having the liquid crystal alignment film according to claim 21.
A liquid crystal layer between a pair of substrates provided with electrodes, and a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates; The liquid crystal display element according to claim 22, which is produced through a step of polymerizing the polymerizable group while applying a voltage therebetween.