WO2012133820A1

WO2012133820A1 - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display element, and method for manufacturing liquid crystal display element

Info

Publication number: WO2012133820A1
Application number: PCT/JP2012/058678
Authority: WO
Inventors: 悟志南; 洋一山之内; 亮一芦澤
Original assignee: 日産化学工業株式会社
Priority date: 2011-03-31
Filing date: 2012-03-30
Publication date: 2012-10-04
Also published as: KR20140037830A; TWI499615B; JP5975227B2; TW201305247A; KR101884044B1; CN103562782B; CN103562782A; JPWO2012133820A1

Abstract

Polyimide precursors each of which has a side chain that serves to align a liquid crystal in a vertical direction and a photoreactive side chain that contains at least one group selected from a methacryl group, an acryl group, a vinyl group, an allyl group, a coumarin group, a styryl group and a cinnamoyl group; and a liquid crystal aligning agent which comprises at least one polymer selected from polyimides produced by imidizing the polyimide precursors, at least one mother nucleus selected from formulae (i-1) to (i-3), a polymerizable compound having a photopolymerizable or photocrosslinkable group at at least one terminal thereof, and a solvent, wherein the photopolymerizable or photocrosslinkable group is directly bound to the mother nucleus or is bound to the mother nucleus through a bonding group.

Description

Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display element, and method for manufacturing liquid crystal display element

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element, and a liquid crystal display element that can be used in the manufacture of a liquid crystal display element of a vertical alignment method that is manufactured by irradiating ultraviolet rays with voltage applied to liquid crystal molecules It relates to a manufacturing method.

In a liquid crystal display element of a method in which liquid crystal molecules aligned perpendicular to a substrate are responded by an electric field (also referred to as a vertical alignment (VA) method), an ultraviolet ray is applied while applying a voltage to the liquid crystal molecules in the manufacturing process. There is a thing including the process of irradiating.

In such a vertical alignment type liquid crystal display element, a photopolymerizable compound is added to a liquid crystal composition in advance and used together with a vertical alignment film such as polyimide to irradiate ultraviolet rays while applying a voltage to a liquid crystal cell. A technique for increasing the response speed of liquid crystal (for example, see Patent Document 1 and Non-Patent Document 1) is known (PSA (Polymer Sustained Alignment) type liquid crystal display). Usually, the direction in which the liquid crystal molecules tilt in response to an electric field is controlled by protrusions provided on the substrate or slits provided on the display electrode, but a liquid crystal composition is added with a photopolymerizable compound. By irradiating ultraviolet rays while applying voltage to the cell, a polymer structure in which the tilted direction of the liquid crystal molecules is memorized is formed on the liquid crystal alignment film. It is said that the response speed of the liquid crystal display element is faster than the control method.

In this PSA type liquid crystal display element, the solubility of the polymerizable compound added to the liquid crystal is low, and there is a problem that when the addition amount is increased, it precipitates at a low temperature. On the other hand, when the addition amount of the polymerizable compound is reduced, a good alignment state cannot be obtained. Moreover, since the unreacted polymerizable compound remaining in the liquid crystal becomes an impurity (contamination) in the liquid crystal, there is a problem that the reliability of the liquid crystal display element is lowered.

Here, it has been reported that the response speed of the liquid crystal display element is increased by adding the photopolymerizable compound to the liquid crystal alignment film instead of the liquid crystal composition (SC-PVA liquid crystal display) (for example, Non-Patent Document 2).

JP 2003-307720 A

In such an SC-PVA mode, a polymerizable compound is contained in the liquid crystal aligning agent, but there is a problem that the storage stability of the liquid crystal aligning agent is poor and components are deposited. For example, even if the component is temporarily dissolved at the stage of manufacturing the liquid crystal aligning agent, the component is likely to precipitate when the liquid crystal aligning agent is stored frozen. And when this photopolymerizable compound is mixed in a liquid crystal display element when it is produced and remains unreacted, it becomes an impurity, which causes a decrease in the reliability of the liquid crystal display element.

Further, since it is desired to further increase the response speed of the liquid crystal display element, it is conceivable to increase the response speed of the liquid crystal display element by increasing the addition amount of the photopolymerizable compound. When the addition amount of the compound is increased, there arises a problem that the storage stability is further deteriorated.

An object of the present invention is to solve the above-mentioned problems of the prior art, and it is possible to improve the response speed of a liquid crystal display device of a vertical alignment method and to have excellent storage stability, and a liquid crystal alignment film Another object of the present invention is to provide a liquid crystal display element and a method for manufacturing the liquid crystal display element.

The liquid crystal aligning agent of the present invention that solves the above problems comprises at least one selected from a side chain for vertically aligning liquid crystals and a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. A polyimide precursor having a photoreactive side chain, at least one polymer selected from polyimides obtained by imidizing the polyimide precursor, and the following formulas (i-1) to (i-3): And a group capable of photopolymerization or photocrosslinking at one or more terminals, and the photopolymerization or photocrosslinkable group is bonded to the mother nucleus directly or via a bonding group. It has a polymerizable compound and a solvent.

The polymerizable compound is preferably selected from the following formulae.

(Wherein R ³¹ is represented by a single bond or —R ³⁵ O—, R ³⁵ is a linear alkylene group having 1 to 10 carbon atoms, and R ³² is represented by a single bond or —OR ³⁶ —. R ³⁶ is a linear alkylene group having 1 to 10 carbon atoms, and R ³³ and R ³⁴ are each independently a hydrogen atom or a methyl group.)

The other liquid crystal aligning agent of the present invention includes a side chain for vertically aligning the liquid crystal and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styrene group, and a cinnamoyl group. A polyimide precursor having a photoreactive side chain, at least one polymer selected from polyimides obtained by imidizing the polyimide precursor, and the following formulas (ii-1) to (ii-3): Polymerization having at least one mother nucleus selected from the group having photopolymerization or photocrosslinking at one or more terminals, wherein the photopolymerization or photocrosslinking group is bonded to the mother nucleus by an oxyalkylene group. It has the characteristic compound and a solvent, It is characterized by the above-mentioned.

The polymerizable compound is preferably selected from the following formulae.

(In the formula, R ⁴¹ is represented by a single bond or —R ⁴⁵ O—, R ⁴⁵ is a linear alkylene group having 1 to 10 carbon atoms, and R ⁴² is represented by a single bond or —OR ⁴⁶ —. R ⁴⁶ is a linear alkylene group having 1 to 10 carbon atoms, and R ⁴³ and R ⁴⁴ are each independently a hydrogen atom or a methyl group.)

The photoreactive side chain preferably contains a group selected from the following formula (I).

(In the formula, R ¹¹ is H or a methyl group.)

In addition, the photopolymerization or photocrosslinking group is preferably selected from the following formula (II).

(Wherein R ¹² is H or an alkyl group having 1 to 4 carbon atoms, and Z ¹ is a divalent alkyl group optionally having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. Z ² is a monovalent aromatic ring or heterocyclic ring optionally substituted by an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms.

The liquid crystal alignment film of the present invention is obtained by applying the above liquid crystal aligning agent to a substrate and baking it.

The liquid crystal display element of the present invention is produced by applying a liquid crystal layer by contacting the liquid crystal aligning agent obtained above by applying the liquid crystal aligning agent to a substrate and baking it, and irradiating ultraviolet rays while applying a voltage to the liquid crystal layer. The liquid crystal cell is provided.

And the manufacturing method of the liquid crystal display element of this invention provides the liquid crystal layer by making it contact with the liquid crystal aligning film obtained by apply | coating the said liquid crystal aligning agent to a board | substrate, and baking, and applying ultraviolet-ray, applying a voltage to this liquid crystal layer. To produce a liquid crystal cell.

According to the present invention, it is possible to provide a liquid crystal aligning agent that can improve the response speed of the liquid crystal display element and is excellent in storage stability.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention has a photoreactive property including a side chain for vertically aligning a liquid crystal and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. A polyimide precursor having a side chain, at least one polymer selected from polyimides obtained by imidizing the polyimide precursor, and the above formulas (i-1) to (i-3). A polymerizable compound having at least one mother nucleus and a group capable of photopolymerization or photocrosslinking at one or more terminals, and the photopolymerization or photocrosslinking group is bonded to the mother nucleus directly or via a bonding group And / or at least one mother nucleus selected from the following formulas (ii-1) to (ii-3) and one or more terminals having a photopolymerizable or photocrosslinkable group, The cross-linking group It has a polymerizable compound bonded with a mother nucleus and an oxyalkylene group, and a solvent. The liquid crystal aligning agent is a solution for forming a liquid crystal aligning film, and the liquid crystal aligning film is a film for aligning liquid crystals in a predetermined direction, in the present invention, in the vertical direction.

First, the polymerizable compound contained in the liquid crystal aligning agent of the present invention will be described in detail. The liquid crystal aligning agent of the present invention has at least one kind of mother nucleus selected from the above formulas (i-1) to (i-3) and a group that undergoes photopolymerization or photocrosslinking at one or more terminals. A polymerizable compound in which a photopolymerizable or photocrosslinking group is bonded to a mother nucleus represented by the above formulas (i-1) to (i-3) directly or via a bonding group (hereinafter referred to as “formula (i-1 ) To (i-3) ”(also referred to as“ polymerizable compound having a mother nucleus ”). That is, the polymerizable compound contained in the liquid crystal aligning agent of the present invention has at least one terminal having a group that undergoes photopolymerization or photocrosslinking, and the group that undergoes photopolymerization or photocrosslinking has the formula (i-1) to A compound that is bonded to at least one structure (mother nucleus) selected from (i-3) directly or via a bonding group.

In addition, the liquid crystal aligning agent of the present invention is used together with a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or the above formulas (i-1) to (i-3). And at least one kind of mother nucleus selected from the above formulas (ii-1) to (ii-3) and one or more terminals at the photopolymerization or photopolymerization. A polymerizable compound having a crosslinkable group and having photopolymerization or a photocrosslinkable group bonded to the mother nucleus by an oxyalkylene group (hereinafter referred to as “mother nucleus represented by the formulas (ii-1) to (ii-3)” At least one or more may be contained.

The polymerizable compound having a photopolymerizable group is a compound having a functional group that causes polymerization upon irradiation with light. The compound having a photocrosslinking group is at least one selected from a polymer of a polymerizable compound, a polyimide precursor, and a polyimide obtained by imidizing the polyimide precursor by irradiating light. It is a compound having a functional group capable of reacting with the polymer and crosslinking with these polymers. A compound having a photocrosslinkable group also reacts with a compound having a photocrosslinkable group.

Such polymerizable compounds having a mother nucleus represented by the above formulas (i-1) to (i-3) and having a mother nucleus represented by the above formulas (ii-1) to (ii-3) A photoreactive property including a polymerizable compound, specifically, a side chain for vertically aligning a liquid crystal, which will be described later, and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. Together with at least one polymer selected from polyimides obtained by imidizing this polyimide precursor and a polyimide precursor, such as SC-PVA liquid crystal display When used in the manufacture of a vertical alignment type liquid crystal display element, a polymer having a side chain and a photoreactive side chain for vertically aligning the liquid crystal and a case where these polymerizable compounds are used alone In comparison, the response speed can be drastically improved, and a liquid crystal display element having a high response speed can be obtained. And even if there is little addition amount of a polymeric compound, a response speed can fully be improved. The liquid crystal aligning agent of the present invention is a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3) or represented by the above formulas (ii-1) to (ii-3). Compared to a polymerizable compound that is not a polymerizable compound having a mother nucleus, for example, a polymerizable compound having a biphenyl structure as a mother nucleus, the sample is stored in a frozen state (for example, in a frozen storage at about −20 ° C.). It becomes a liquid crystal aligning agent excellent in storage stability.

Examples of the group that undergoes photopolymerization or photocrosslinking include monovalent groups represented by the above formula (II).

A polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or a polymerizable compound having a mother nucleus represented by the above formulas (ii-1) to (ii-3) Specific examples of the compound include a compound having a photopolymerizable group at each of two terminals represented by the following formula (III), a terminal having a photopolymerizable group represented by the following formula (IV), and Examples thereof include a compound having a terminal having a photocrosslinking group and a compound having a photocrosslinking group at each of two terminals represented by the following formula (V). In Formula ^{(III) ~ (V),} R 12, Z 1 and ^{Z 2} are the same as ^R 12, ^{Z 1} and ^{Z 2} in the formula (II), ^{Q 1} is the formula (i-1 ) To (i-3) or an oxyalkylene group bonded to both ends of the structures represented by the above formulas (ii-1) to (ii-3). It is a divalent organic group. Q ¹ preferably has an oxyalkylene group or an alkylene group. This is because the interaction with the liquid crystal tends to increase.

Specific examples of the polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3) include compounds represented by the following formulae.

Further, specific examples of the polymerizable compound having a mother nucleus represented by the above formulas (ii-1) to (ii-3) include compounds represented by the following formulae.

In general, the process of forming a liquid crystal alignment film includes a step of baking at a high temperature to completely remove the solvent, but α-methylene-γ-butyrolactone groups which are polymerizable groups (photopolymerizable groups) at both ends. If it is a polymerizable compound having a high temperature, it can sufficiently withstand a high temperature, for example, a firing temperature of 200 ° C. or higher, because of its poor thermal polymerization structure. It should be noted that even if the photopolymerization or photocrosslinking group is a polymerizable compound having an acrylate group or a methacrylate group instead of an α-methylene-γ-butyrolactone group, the acrylate group or methacrylate group is a spacer such as an oxyalkylene group. In the case of a polymerizable compound having a structure bonded to a phenylene group via a hydrogen atom, the stability to heat is improved similarly to the polymerizable compound having an α-methylene-γ-butyrolactone group at the terminal, It can sufficiently withstand a high temperature, for example, a firing temperature of 200 ° C. or higher.

The method for producing such a polymerizable compound is not particularly limited, and for example, it can be produced according to the synthesis examples described later. For example, a polymerizable compound can be synthesized by combining techniques in organic synthetic chemistry. For example, taraga and the like represented by the following reaction formula are prepared by the method proposed by P. Talaga, M. Schaeffer, C. Benezra and JLStampf, Synthesis, 530 (1990) using SnCl ₂ and 2- (bromomethyl) acrylic acid. It can be synthesized by reacting (2- (bromomethyl) propenoic acid) with aldehyde or ketone. Amberlyst 15 is a strongly acidic ion exchange resin manufactured by Rohm and Haas.

(In the formula, R ′ represents a monovalent organic group.)

In addition, 2- (bromomethyl) acrylic acid is represented by the following reaction formula: K. Ramarajan, K. Kamalingam, DJO 'Donnell and KDBerlin, Organic Synthesis, vol.61, 56-59 (1983) It can be synthesized by the method proposed in.

The liquid crystal aligning agent of the present invention includes a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or the above formulas (ii-1) to (ii- Two or more polymerizable compounds having a mother nucleus represented by 3) may be contained.

In addition, a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or a polymerization having a mother nucleus represented by the above formulas (ii-1) to (ii-3). In addition to the polymerizable compound, a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or represented by the above formulas (ii-1) to (ii-3) One or two or more polymerizable compounds that are not polymerizable compounds having a mother nucleus (hereinafter also referred to as “other polymerizable compounds”) may be contained.

Examples of the group that undergoes photopolymerization or photocrosslinking of the other polymerizable compound include monovalent groups represented by the above formula (II).

Specific examples of the other polymerizable compound include a compound having a photopolymerizable group at each of two ends as represented by the following formula (XV), and a photopolymerization represented by the following formula (XVI). And a compound having a terminal having a photocrosslinking group and a compound having a photocrosslinking group, and a compound having a photocrosslinking group at each of two terminals represented by the following formula (XVII). In the following formulas (XV) to (XVII), R ¹⁷ is H or an alkyl group having 1 to 4 carbon atoms, and Z ³ is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. A divalent aromatic ring or heterocyclic ring which may be substituted, and Z ⁴ is a monovalent aromatic ring which may be substituted by an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms; Heterocycle. Q ² does not have a structure represented by the above formulas (i-1) to (i-3) and has a structure represented by the above formulas (ii-1) to (ii-3). It is a divalent organic group having no oxyalkylene group bonded to both ends. Q ² has a ring structure such as a phenylene group (—C ₆ H ₄ —), a biphenylene group (—C ₆ H ₄ —C ₆ H ₄ —), a cyclohexylene group (—C ₆ H ₁₀ —), and the like. Preferably it is. This is because the interaction with the liquid crystal tends to increase.

Examples of the polymerizable compound represented by the formula (XV) include a polymerizable compound represented by the following formula (XVIII). In the following formula (XVIII), V ¹ is a single bond or —R ²¹ O—, R ²¹ is a linear or branched alkylene group having 1 to 10 carbon atoms, and W ¹ is a single bond or —OR ²² - represented by ^{R 22} is a straight-chain or branched alkylene group having 1 to 10 carbon ^{atoms, R 18} is hydrogen atom or a methyl group.

Specific examples of the compound represented by the above formula (XVIII) include polymerizable compounds represented by the following formula.

(Wherein R ¹⁸ is H or a methyl group.)

The method for producing such other polymerizable compounds is not particularly limited, and for example, the polymerizable compound can be synthesized by combining techniques in organic synthetic chemistry. As a specific synthesis example, for example, the formula (XV) can be synthesized by the reaction of the following formula. In the following reaction formula, R ¹⁹ and R ²⁰ are each independently a linear or branched alkylene group having 1 to 10 carbon atoms. THF is an abbreviation for tetrahydrofuran.

The liquid crystal aligning agent of the present invention is at least one selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor, and a side chain and a photoreactive side for vertically aligning liquid crystals. A polymer having a chain. Examples of the polyimide precursor include polyamic acid (also referred to as polyamic acid), polyamic acid ester, and the like.

The side chain for vertically aligning the liquid crystal of the polymer is not limited as long as the liquid crystal can be aligned vertically with respect to the substrate. For example, a long chain alkyl group or a middle of a long chain alkyl group may be used. And a group having a ring structure or a branched structure, a hydrocarbon group such as a steroid group, or a group in which some or all of the hydrogen atoms of these groups are replaced with fluorine atoms. Of course, you may have the side chain which orientates two or more types of liquid crystal vertically. The side chain for vertically aligning the liquid crystal may be directly bonded to a polyimide precursor such as polyamic acid or polyamic acid ester or a main chain of polyimide, that is, a polyamic acid skeleton, a polyimide skeleton, or the like. You may couple | bond together through a coupling group. Examples of the side chain for vertically aligning the liquid crystal include a hydrocarbon group having 8 to 30 carbon atoms, preferably 8 to 22 carbon atoms in which hydrogen atoms may be substituted with fluorine, specifically, alkyl groups, fluoro Examples thereof include an alkyl group, an alkenyl group, a phenethyl group, a styrylalkyl group, a naphthyl group, and a fluorophenylalkyl group. Examples of the side chain for vertically aligning other liquid crystals include those represented by the following formula (a).

(In the formula (a), l, m and n each independently represents an integer of 0 or 1, and R ³ represents an alkylene group having 2 to 6 carbon atoms, —O—, —COO—, —OCO—, —NHCO—. , -CONH-, or an alkylene-ether group having 1 to 3 carbon atoms, R ⁴ , R ⁵ and R ⁶ each independently represents a phenylene group or a cycloalkylene group, R ⁷ is a hydrogen atom, 2 to 24 represents an alkyl group or a fluorine-containing alkyl group, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent heterocyclic ring, or a monovalent macrocyclic substituent comprising them.)

R ³ in the above formula (a) is preferably —O—, —COO—, —CONH—, or an alkylene-ether group having 1 to 3 carbon atoms from the viewpoint of ease of synthesis.

R ⁴ , R ⁵ and R ⁶ in the formula (a) are l, m, n, R ⁴ and R ⁵ shown in Table 1 below from the viewpoint of ease of synthesis and ability to align liquid crystals vertically. And a combination of R ⁶ is preferred.

When at least one of l, m and n is 1, R ⁷ in the formula (a) is preferably a hydrogen atom, an alkyl group having 2 to 14 carbon atoms or a fluorine-containing alkyl group, more preferably A hydrogen atom, an alkyl group having 2 to 12 carbon atoms, or a fluorine-containing alkyl group. When l, m and n are all 0, R ⁷ is preferably an alkyl group having 12 to 22 carbon atoms or a fluorine-containing alkyl group, a monovalent aromatic ring, a monovalent aliphatic ring, a monovalent Heterocycles and monovalent macrocyclic substituents composed of these are preferred, and alkyl groups having 12 to 20 carbon atoms or fluorine-containing alkyl groups are more preferred.

The amount of the side chain that vertically aligns the liquid crystal is not particularly limited as long as the liquid crystal alignment film can align the liquid crystal vertically. However, in the liquid crystal display element having the liquid crystal alignment film, the amount of side chains that vertically align the liquid crystal is possible within a range that does not impair the display characteristics of the element such as voltage holding ratio and accumulation of residual DC voltage. As few as possible is preferable.

The ability of a polymer having side chains for vertically aligning liquid crystals to align liquid crystals vertically varies depending on the structure of the side chains for vertically aligning liquid crystals, but in general, the side chains for vertically aligning liquid crystals. As the amount increases, the ability to align the liquid crystal vertically increases, and as it decreases, it decreases. Moreover, when it has a cyclic structure, compared with what does not have a cyclic structure, there exists a tendency for the capability to orientate a liquid crystal vertically.

Further, the polymer composed of at least one of polyimide precursors such as polyamic acid and polyamic acid ester and polyimide contained in the liquid crystal aligning agent of the present invention has a photoreactive side chain. The photoreactive side chain is a side chain having a functional group (hereinafter also referred to as a photoreactive group) that can react by irradiation with light such as ultraviolet rays (UV) to form a covalent bond. Includes at least one selected from a methacryl group, an acryl group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group as a photoreactive group. Thus, a polymer comprising at least one of polyimide precursors such as polyamic acid and polyamic acid ester to be contained in the liquid crystal aligning agent and polyimide, methacryl group, acrylic group, vinyl group, allyl group, coumarin group, styryl group and By having a photoreactive side chain containing at least one selected from cinnamoyl groups and using it in a liquid crystal aligning agent together with the polymerizable compound, the response speed is remarkably improved as shown in the examples described later. be able to.

The photoreactive side chain may be directly bonded to the polyimide precursor or the main chain of the polyimide, or may be bonded via an appropriate bonding group. Examples of the photoreactive side chain include those represented by the following formula (b).

(In the formula (b), R ⁸ is a single bond or —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N Represents any one of (CH ₃ ) —, —CON (CH ₃ ) —, —N (CH ₃ ) CO—, and R ⁹ is a single bond, or unsubstituted or substituted with a fluorine atom. Represents an alkylene group of ˜20, and —CH ₂ — in the alkylene group may be optionally replaced by —CF ₂ — or —CH═CH—, and when any of the following groups is not adjacent to each other: , may be substituted with these groups; -O -, - COO -, - OCO -, - NHCO -, - CONH -, - NH-, a divalent carbocyclic, divalent heterocyclic ^{.R 10} Is a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, Styryl group, a cinnamoyl group.)

R ⁸ in the above formula (b) can be formed by an ordinary organic synthetic method, but from the viewpoint of ease of synthesis, —CH ₂ —, —O—, —COO—, —NHCO —, —NH— and —CH ₂ O— are preferred.

Specific examples of the divalent carbocycle or divalent heterocycle carbocycle or heterocycle for replacing any —CH ₂ — in R ⁹ include the following structures, but are not limited thereto. Is not to be done.

R ¹⁰ is preferably a methacryl group, an acryl group or a vinyl group from the viewpoint of photoreactivity.

The above formula (b) is more preferably a structure containing a group selected from the above formula (I).

The amount of the photoreactive side chain is preferably within a range in which the response speed of the liquid crystal can be increased by reacting with ultraviolet irradiation to form a covalent bond. In order to further increase the response speed of the liquid crystal As many as possible are preferable as long as other characteristics are not affected. For example, the amount of photoreactive side chain introduced into the polyimide precursor or polyimide is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, and particularly preferably 30 to 50 mol%.

Such a liquid crystal has a side chain for vertically aligning and a photoreactive side chain containing at least one selected from a methacryl group, an acryl group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. A method for producing a polyimide precursor and at least one polymer selected from polyimides obtained by imidizing the polyimide precursor is not particularly limited. For example, by a reaction between a diamine and tetracarboxylic dianhydride. In a method for obtaining a polyamic acid, a diamine having a side chain for vertically aligning a liquid crystal or a tetracarboxylic dianhydride having a side chain for vertically aligning a liquid crystal, a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin Photoreactive side comprising at least one selected from a group, a styryl group and a cinnamoyl group A diamine or a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group and a tetracarboxylic dianhydride having a photoreactive side chain containing at least one selected from a cinnamoyl group. Just do it.

Examples of the diamine having a side chain for vertically aligning the liquid crystal include a long chain alkyl group, a group having a ring structure or a branched structure in the middle of the long chain alkyl group, a hydrocarbon group such as a steroid group, and the hydrogen of these groups. A diamine having a side chain with a group in which some or all of the atoms are replaced with fluorine atoms, for example, a diamine having a side chain represented by the above formula (a) can be mentioned. More specifically, for example, a diamine having a hydrocarbon group having 8 to 30 carbon atoms in which a hydrogen atom may be substituted with fluorine, or the following formulas (2), (3), (4), (5 The diamine represented by this can be mentioned, However, It is not limited to this.

(The definitions of l, m, n and R ³ to R ^{7 in} the formula (2) are the same as those in the above formula (a).)

(In Formula (3) and Formula (4), A ₁₀ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , A ₁₁ represents a single bond or a phenylene group, a represents the same structure as a side chain for vertically aligning the liquid crystal represented by the above formula (a), and a ′ is represented by the above formula (a). (This represents a divalent group having a structure in which one element such as hydrogen is removed from the same structure as the side chain that vertically aligns the liquid crystal.)

(In the formula (5), A ₁₄ is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom, and A ₁₅ is a 1,4-cyclohexylene group, or 1,4- A phenylene group, A ₁₆ is an oxygen atom or —COO— * (where a bond marked with “*” is bonded to A ₁₅ ), and A ₁₇ is an oxygen atom or —COO — * ( However, bond marked with "*" is _(CH 2) binds to _{a 2.)} is. in addition, _{a 1} is 0, or an integer 1, _{a 2} is an integer from 2 to 10, a ₃ is 0 or an integer of 1.

Binding positions of the two amino group (-NH ₂₎ in equation (2) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the structure of the formula (2) include diamines represented by the following formulas [A-1] to [A-24], but are not limited thereto.

(In the formulas [A-1] to [A-5], A ₁ is an alkyl group having 2 to 24 carbon atoms or a fluorine-containing alkyl group.)

(In Formula [A-6] and Formula [A-7], A ₂ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and ₃ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

(In the formulas [A-8] to [A-10], A ₄ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, or —CH ₂ —, and A ₅ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

(In Formula [A-11] and Formula [A-12], A ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ —, —O—, or —NH—, and A ₇ represents fluorine group, cyano group, trifluoromethane group, nitro group, azo group, formyl group, acetyl group, acetoxy Group or hydroxyl group.)

(In Formula [A-13] and Formula [A-14], A ₈ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

(In the formulas [A-15] and [A-16], A ₉ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is a trans isomer. .)

Specific examples of the diamine represented by the formula (3) include diamines represented by the following formulas [A-25] to [A-30], but are not limited thereto.

(In the formulas [A-25] to [A-30], A ₁₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—, and A ₁₃ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

Specific examples of the diamine represented by the formula (4) include diamines represented by the following formulas [A-31] to [A-32], but are not limited thereto.

Among these, [A-1], [A-2], [A-3], [A-4], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5], [A-5] The diamines of A-25], [A-26], [A-27], [A-28], [A-29], and [A-30] are preferred.

The above-mentioned diamines can be used alone or in combination of two or more depending on the properties such as liquid crystal orientation, pretilt angle, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

The diamine having a side chain for vertically aligning the liquid crystal is preferably used in an amount of 5 to 50 mol% of the diamine component used for the synthesis of the polyamic acid, more preferably 10 to 40 mol% of the diamine component. Is a diamine having a side chain for vertically aligning the liquid crystal, particularly preferably 15 to 30 mol%. When the diamine having a side chain for vertically aligning the liquid crystal is used in an amount of 5 to 50 mol% of the diamine component used for the synthesis of the polyamic acid, it is particularly excellent in terms of improving the response speed and fixing the alignment of the liquid crystal. .

Examples of the diamine having a photoreactive side chain including at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group are represented by the above formula (b). And diamines having side chains. More specifically, examples include diamines represented by the following general formula (6), but are not limited thereto.

(The definitions of R ⁸ , R ⁹ and R ¹⁰ in Formula (6) are the same as those in Formula (b) above.)

The bonding position of the two amino groups (—NH ₂ ) in Formula (6) is not limited. Specifically, with respect to the linking group of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring, 3, 4 position, 5 positions. Among these, from the viewpoint of reactivity when synthesizing a polyamic acid, positions 2, 4, 2, 5, or 3, 5 are preferable. Considering the ease in synthesizing the diamine, the positions 2, 4 or 3, 5 are more preferable.

Specific examples of the diamine having a photoreactive side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group include the following compounds: Although it is mentioned, it is not limited to this.

(Wherein X is a single bond or a linking group selected from —O—, —COO—, —NHCO—, —NH—, Y is unsubstituted or substituted with a fluorine atom and having 1 to 20 carbon atoms) Represents an alkylene group.)

The diamine having a photoreactive side chain containing at least one selected from the methacryl group, acryl group, vinyl group, allyl group, coumarin group, styryl group and cinnamoyl group is a liquid crystal alignment property when used as a liquid crystal alignment film. Depending on the characteristics such as the pretilt angle, the voltage holding characteristic, the accumulated charge, the response speed of the liquid crystal when the liquid crystal display element is used, one kind or a mixture of two or more kinds can be used.

In addition, such a diamine having a photoreactive side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group and a cinnamoyl group is a diamine used for the synthesis of polyamic acid. It is preferable to use an amount of 10 to 70 mol% of the component, more preferably 20 to 60 mol%, particularly preferably 30 to 50 mol%.

In addition, as long as the polyamic acid does not impair the effect of the present invention, other diamines other than the diamine having a side chain for vertically aligning the liquid crystal and the diamine having a photoreactive group are used as a diamine component. be able to. Specifically, for example, 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′- Aminobiphenyl, 3,3′-difluoro-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'-diaminodiphenyl methane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4 ' -Sulphonyldianiline, 3,3'-sulfonyl Aniline, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3 , 3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl ( 4,4'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) Amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diamino Benzophenone, 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, , 4-bis (4-aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis ( , 5-Diethyl-4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1,4- Phenylenebis (methylene)] dianiline, 4,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,4 ′-[1,4-phenylenebis (methylene)] dianiline, 3,4 ′-[ 1,3-phenylenebis (methylene)] dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3-phenylenebis (methylene)] di Nilin, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4 -Aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, bis (3- Aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamido) ), N, N ′-(1,3-phenylene) bis (4-aminobenzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1 , 3-phenylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis ( 4-aminophenyl) isophthalamide, N, N′-bis (3-aminophenyl) 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, 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-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) Nonane, 1,10- (4-aminophenoxy) decane, 1,10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane 1,12- (4-aminophenoxy) dodecane, aromatic diamine such as 1,12- (3-aminophenoxy) dodecane, bis (4-aminocyclohexyl) To cycloaliphatic diamines such as sil) methane and bis (4-amino-3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diamino And aliphatic diamines such as xanthone, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, etc. .

The above-mentioned other diamines can be used alone or in combination of two or more according to properties such as liquid crystal orientation, pretilt angle, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

The tetracarboxylic dianhydride to be reacted with the diamine component in the synthesis of polyamic acid is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2, 3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4-biphenyltetra Carboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxy) Phenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphene) Propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3 , 4-dicarboxyphenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3 4-cyclobutanetetracarboxylic acid, oxydiphthaltetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexane Tetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4 Cyclobutanetetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, bicyclo [4,3,0] nonane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0 ] Decane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] decane-2,4,8,10-tetracarboxylic acid, tricyclo [6.3.0.0 <2,6 >] Ndecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4 -Tetrahydraphthalene-1,2-dicarboxylic acid, bicyclo [2,2,2] oct-7-ene-2,3,5,6-tetracarboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodeca-4,5,9,10-tetracarboxylic acid, 3, Examples include 5,6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid and the like. Of course, tetracarboxylic dianhydride may be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

In obtaining a polyamic acid by a reaction between a diamine component and tetracarboxylic dianhydride, a known synthesis method can be used. In general, the diamine component and tetracarboxylic dianhydride are reacted in an organic solvent. The reaction between the diamine component and tetracarboxylic dianhydride is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

The organic solvent used in the above reaction is not particularly limited as long as the generated polyamic acid is soluble. Furthermore, even if it is an organic solvent in which a polyamic acid does not melt | dissolve, you may mix and use the said solvent in the range which the produced | generated polyamic acid does not precipitate. In addition, since the water | moisture content in an organic solvent inhibits a polymerization reaction and also causes the produced polyamic acid to hydrolyze, it is preferable to use what dehydrated and dried the organic solvent. Examples of the organic solvent used in the reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2- Pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide , Γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl Rosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether , Propylene glycol monobutyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, di Propylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3 -Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl Ether, dioxane, n-hexane, n-pentane, n-octane, Ethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethyl ethyl ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl Examples include -2-pentanone and 2-ethyl-1-hexanol. These organic solvents may be used alone or in combination.

When the diamine component and the tetracarboxylic dianhydride component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is used as it is or in an organic solvent. A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. is mentioned, You may use any of these methods. In addition, when the diamine component or tetracarboxylic dianhydride component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. The body may be mixed and reacted to form a high molecular weight body.

The temperature at the time of reacting the diamine component and the tetracarboxylic dianhydride component can be selected arbitrarily, and is, for example, in the range of −20 ° C. to 150 ° C., preferably −5 ° C. to 100 ° C. The reaction can be carried out at any concentration. For example, the total amount of the diamine component and the tetracarboxylic dianhydride component is 1 to 50% by mass, preferably 5 to 30% by mass, based on the reaction solution.

In the above polymerization reaction, the ratio of the total number of moles of the tetracarboxylic dianhydride component to the total number of moles of the diamine component can be selected according to the molecular weight of the polyamic acid to be obtained. Similar to the normal polycondensation reaction, the molecular weight of the polyamic acid produced increases as the molar ratio approaches 1.0. If it shows a preferable range, it is 0.8 to 1.2.

The method for synthesizing the polyamic acid used in the present invention is not limited to the above-described method, and in the same manner as the general polyamic acid synthesis method, instead of the tetracarboxylic dianhydride, a tetracarboxylic acid having a corresponding structure is used. The corresponding polyamic acid can also be obtained by reacting by a known method using a tetracarboxylic acid derivative such as acid or tetracarboxylic acid dihalide.

Examples of the method for imidizing the polyamic acid to obtain a polyimide include thermal imidization in which the polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution. The imidation ratio from polyamic acid to polyimide is not necessarily 100%.

The temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and is preferably carried out while removing water generated by the imidization reaction from the outside of the system.

The catalytic imidation of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring at -20 to 250 ° C., preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the 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.

The polyamic acid ester is a reaction of a tetracarboxylic acid diester dichloride with a diamine similar to the synthesis of the polyamic acid, a suitable condensing agent with a diamine similar to the synthesis of the tetracarboxylic acid diester and the polyamic acid, It can be produced by reacting in the presence of a base or the like. Alternatively, it can also be obtained by previously synthesizing a polyamic acid by the above method and esterifying the carboxylic acid in the polyamic acid using a polymer reaction. Specifically, for example, tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 hour. By reacting for ˜4 hours, a polyamic acid ester can be synthesized. The polyimide can also be obtained by heating the polyamic acid ester at a high temperature to promote dealcoholization and ring closure.

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

As described above, the liquid crystal aligning agent of the present invention comprises at least one selected from a side chain for vertically aligning liquid crystals and a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. A polyimide precursor having a photoreactive side chain and at least one polymer selected from polyimides obtained by imidizing the polyimide precursor, and the above formulas (i-1) to (i-3) And / or a polymerizable compound having a mother nucleus represented by the above formulas (ii-1) to (ii-3) and a solvent. The blending ratio is not particularly limited, but the polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3) and the above formulas (ii-1) to (ii) -3) A polymerizable compound having a mother nucleus represented by A photoreactive side including a side chain that vertically aligns the liquid crystal and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. It is preferably 1 to 50 parts by mass, more preferably 100 parts by mass of at least one polymer selected from a polyimide precursor having a chain and a polyimide obtained by imidizing this polyimide precursor. Is 5 to 30 parts by mass. As described above, the liquid crystal aligning agent of the present invention includes a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), and the above formulas (ii-1) to (ii-3). The response speed is sufficiently high even when the amount of the polymerizable compound having a mother nucleus represented by (2) is small. Since the liquid crystal aligning agent of the present invention is excellent in storage stability, in order to further improve the response speed, the polymerization property having a mother nucleus represented by the above formulas (i-1) to (i-3) Even when the compound and the polymerizable compound having a mother nucleus represented by the above formulas (ii-1) to (ii-3) are added in some amount, the storage stability is good. In addition, a photoreactive material including a side chain for vertically aligning a liquid crystal contained in the liquid crystal aligning agent and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. The content of at least one polymer selected from a polyimide precursor having a side chain and a polyimide obtained by imidizing this polyimide precursor is preferably 1% by mass to 20% by mass, more preferably 3% by mass. % To 15% by mass, particularly preferably 3% to 10% by mass.

The liquid crystal aligning agent of the present invention is a photoreaction comprising a side chain for vertically aligning liquid crystals and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. It may contain other polymers other than at least one polymer selected from a polyimide precursor having a functional side chain and a polyimide obtained by imidizing this polyimide precursor. In that case, the content of the other polymer in all the polymer components is preferably 0.5% by mass to 15% by mass, more preferably 1% by mass to 10% by mass.

The molecular weight of the polymer of the liquid crystal aligning agent is determined by considering the strength of the liquid crystal aligning film obtained by applying the liquid crystal aligning agent, the workability at the time of forming the coating film, and the uniformity of the coating film, GPC (Gel Permeation Chromatography). The weight average molecular weight measured by the above method is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

The solvent contained in the liquid crystal aligning agent is not particularly limited, and is at least one selected from a side chain for vertically aligning the liquid crystal, and a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. And a polyimide precursor having a photoreactive side chain containing at least one polymer selected from polyimides obtained by imidizing the polyimide precursor, and the above formulas (i-1) to (i- 3) which can dissolve or disperse components such as a polymerizable compound having a mother nucleus represented by 3) and a polymerizable compound having a mother nucleus represented by the above formulas (ii-1) to (ii-3). I just need it. For example, the organic solvent which was illustrated by the synthesis | combination of said polyamic acid can be mentioned. Among them, N-methyl-2-pyrrolidone, γ-butyrolactone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N, N-dimethylpropanamide are from the viewpoint of solubility. To preferred. Of course, two or more kinds of mixed solvents may be used.

In addition, it is preferable to use a solvent that improves the uniformity and smoothness of the coating film mixed with a solvent in which the components of the liquid crystal aligning agent are highly soluble. Solvents that improve the uniformity and smoothness of the coating include, for example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol Thor, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol-tert-butyl ether , Dipropylene glycol monomethyl Ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether , Dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, dii Butylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, acetic acid Ethyl, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1- Phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2- Ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, 2-ethyl-1-hexanol and the like. A plurality of these solvents may be mixed. When these solvents are used, the content is preferably 5 to 80% by mass, more preferably 20 to 60% by mass based on the total amount of the solvent contained in the liquid crystal aligning agent.

The liquid crystal aligning agent may contain components other than those described above. Examples include compounds that improve film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, compounds that improve the adhesion between the liquid crystal aligning film and the substrate, polymerization initiators and polymerization inhibitors. It is done. The polymerization inhibitor is added to facilitate handling of a polymerizable compound having high polymerizability.

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.). When these surfactants are used, the ratio of use thereof is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent. 1 part by mass.

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N′-tetraglycidyl-4, 4′-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, etc. . In order to further increase the film strength of the liquid crystal alignment film, a phenol compound such as 2,2′-bis (4-hydroxy-3,5-dihydroxymethylphenyl) propane or tetra (methoxymethyl) bisphenol may be added. When these compounds are used, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.

In addition, examples of the polymerization initiator include radical polymerization initiators. Examples of the radical polymerization initiator include benzoin derivatives and compounds composed of peroxides.

Preferred examples of the benzoin derivative include (±) -camphorquinone, 2,2-diethoxyacetophenone, 2,4-diethylthioxanthen-9-one, 2-benzoylbenzoic acid, 2-chlorobenzophenone, 2-chlorothioxanthone 2-ethylanthraquinone, 2-isonitrosopropiophenone, 2-isopropylthioxanthone, 2-phenyl-2- (p-toluenesulfonyloxy) acetophenone, 4,4′-dichlorobenzophenone, 4-benzoyl-4′-methyl Diphenyl sulfide, 4-benzoylbenzoic acid, 4-chlorobenzophenone, acetophenone, diphenylethanedione, benzoin, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzoin methyl Ether, benzophenone, dibenzosuberone, 9-fluorenone, methyl 2-benzoylbenzoate, 4,4-dimethoxybenzoyl, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, Michler's ketone, Examples include “Darocur Series 1173, 4265” and “Irgacure Series 184, 500, 651, 819, 2959” manufactured by Ciba Specialty Co., Ltd. A particularly preferred example of the benzoin derivative is Irgacure 651 manufactured by Ciba Specialty Co., Ltd.

Preferred examples of the compound consisting of peroxide include Pertetra A, Perhexa HC, Perhexa C, Perhexa V, Perhexa 22, Perbutyl D, Perhexyl D, Parroyl 355, Parroyl L, and Niper BW manufactured by NOF Corporation. , Niper BMT, Parroyl TCP, Park Mill ND, Perocta ND, Perhexyl ND, Perbutyl NHP, Perhexyl PV, Perbutyl PV, Perhexa 25O, Perocta O, Perhexyl O, Perbutyl O, Perbutyl L, Perbutyl 355, Perhexyl I, Perbutyl E, Perhexa 25Z, perbutyl A, perhexyl Z, perbutyl Z, perbutyl ZT, and the like. Particularly preferred examples of the peroxide compound include “Parroyl L, Nyper BW, Nyper BMT, Perocta O, Perhexyl O, Perbutyl O” manufactured by NOF Corporation.

Two or more kinds of these polymerization initiators may be combined, and an example of a preferable combination is a mixture of benzophenone and Michler's ketone.

When a polymerization initiator is used, the use ratio thereof is preferably 10% by mass or less based on the total amount of the polymerizable compound in order to prevent the polymerization initiator from acting as an impurity and degrading the display quality of the display element.

In addition, when a polymerization inhibitor is added, its use ratio is desirably 10% by weight or less with respect to the total amount of the polymerizable compound in order to prevent the polymerization inhibitor from acting as an impurity.

In addition to the above, the liquid crystal aligning agent is added with a dielectric or conductive material for changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, as long as the effects of the present invention are not impaired. May be.

By applying this liquid crystal aligning agent on a substrate and baking it, a liquid crystal alignment film for vertically aligning liquid crystals can be formed. The liquid crystal aligning agent of the present invention is a photoreactive material including a side chain for vertically aligning liquid crystals and at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. Along with a polyimide precursor having a side chain and at least one polymer selected from polyimides obtained by imidizing this polyimide precursor, the compounds are represented by the above formulas (i-1) to (i-3). Response of liquid crystal display element using liquid crystal alignment film obtained because it has polymerizable compound having mother nucleus and polymerizable compound having mother nucleus represented by the above formulas (ii-1) to (ii-3) The speed can be high. In addition, the liquid crystal aligning agent of the present invention is excellent in storage stability, and since precipitation of components is suppressed even when stored frozen, a liquid crystal aligning agent is manufactured, and after being stored frozen, a liquid crystal aligning film is manufactured. Can do.

For example, a cured film obtained by applying the liquid crystal aligning agent of the present invention to a substrate and then drying and baking as necessary can be used as a liquid crystal aligning film as it is. In addition, this cured film is rubbed, irradiated with polarized light or light of a specific wavelength, treated with an ion beam, etc., and a voltage is applied to the liquid crystal display element after filling the liquid crystal as an alignment film for SC-PVA. It is also possible to irradiate UV in such a state.

At this time, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, glass plate, polycarbonate, poly (meth) acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, Trimethylpentene, polyolefin, polyethylene terephthalate, (meth) acrylonitrile, triacetyl cellulose, diacetyl cellulose, acetate butyrate cellulose, and the like can be used. In addition, it is preferable to use a substrate on which an ITO (Indium Tin Oxide) electrode or the like for driving a liquid crystal is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

The method for applying the liquid crystal aligning agent is not particularly limited, and examples thereof include screen printing, offset printing, flexographic printing, and other printing methods, ink jet methods, spray methods, roll coating methods, dip, roll coaters, slit coaters, and spinners. From the standpoint of productivity, the transfer printing method is widely used industrially, and is preferably used in the present invention.

The coating film formed by applying the liquid crystal aligning agent by the above method can be baked to obtain a cured film. The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, the drying process is performed. It is preferable. The drying is not particularly limited as long as the solvent is removed to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. For example, a method of drying on a hot plate at a temperature of 40 ° C. to 150 ° C., preferably 60 ° C. to 100 ° C., for 0.5 minutes to 30 minutes, preferably 1 minute to 5 minutes.

The firing temperature of the coating film formed by applying the liquid crystal aligning agent is not limited, and can be performed at any temperature of, for example, 100 to 350 ° C., preferably 120 ° C. to 300 ° C., more preferably 150 to 250 ° C. Firing can be performed at an arbitrary time of 5 minutes to 240 minutes. The time is preferably 10 minutes to 90 minutes, more preferably 20 minutes to 90 minutes. Heating can be performed by a generally known method such as a hot plate, a hot air circulating furnace, an infrared furnace, or the like.

The thickness of the liquid crystal alignment film obtained by firing is not particularly limited, but is preferably 5 to 300 nm, more preferably 10 to 120 nm.

And the liquid crystal display element of this invention can produce a liquid crystal cell by a well-known method after forming a liquid crystal aligning film in a board | substrate by said method. Specific examples of the liquid crystal display element include two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal aligning agent provided between the substrate and the liquid crystal layer. A vertical alignment type liquid crystal display device comprising a liquid crystal cell having the above-described liquid crystal alignment film. Specifically, the liquid crystal aligning agent of the present invention is applied onto two substrates and baked to form a liquid crystal aligning film, and the two substrates are arranged so that the liquid crystal aligning films face each other. A liquid crystal layer composed of liquid crystal is sandwiched between two substrates, that is, a liquid crystal layer is provided in contact with the liquid crystal alignment film, and ultraviolet rays are applied while applying a voltage to the liquid crystal alignment film and the liquid crystal layer. This is a vertical alignment type liquid crystal display device including a liquid crystal cell to be manufactured. As described above, the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention is used to irradiate ultraviolet rays while applying voltage to the liquid crystal alignment film and the liquid crystal layer to polymerize the polymerizable compound, and the light possessed by the polymer. A liquid crystal display device in which the alignment of the liquid crystal is more efficiently fixed and the response speed is remarkably improved by reacting the reactive side chains or the photoreactive side chain of the polymer with the polymerizable compound. It becomes.

The substrate used in the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, the thing similar to the board | substrate described with the said liquid crystal aligning film can be mentioned. A substrate provided with a conventional electrode pattern or protrusion pattern may be used, but in the liquid crystal display element of the present invention, the liquid crystal aligning agent of the present invention is used as the liquid crystal aligning agent for forming the liquid crystal aligning film. It is possible to operate even in a structure in which a line / slit electrode pattern of 1 to 10 μm, for example, is formed on one side substrate and a slit pattern or projection pattern is not formed on the opposite substrate. This process can be simplified and high transmittance can be obtained.

Further, in a high-performance element such as a TFT type element, an element in which an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate is used.

In the case of a transmissive liquid crystal display element, it is common to use a substrate as described above. However, in a reflective liquid crystal display element, if only one substrate is used, an opaque substrate such as a silicon wafer may be used. Is possible. At that time, a material such as aluminum that reflects light may be used for the electrode formed on the substrate.

The liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and baking it, and the details are as described above.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and a liquid crystal material used in a conventional vertical alignment method, for example, a negative type liquid crystal such as MLC-6608 or MLC-6609 manufactured by Merck Can be used.

As a method for sandwiching the liquid crystal layer between two substrates, a known method can be exemplified. For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, and spacers such as beads are dispersed on the liquid crystal alignment film on one substrate so that the surface on which the liquid crystal alignment film is formed is on the inside. Then, the other substrate is bonded, and liquid crystal is injected under reduced pressure to seal. Also, a pair of substrates on which a liquid crystal alignment film is formed are prepared, and spacers such as beads are dispersed on the liquid crystal alignment film on one substrate, and then liquid crystal is dropped, and then the surface on which the liquid crystal alignment film is formed A liquid crystal cell can also be produced by a method in which the other substrate is bonded to the inside so as to be inside and sealed. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

The step of producing a liquid crystal cell by irradiating ultraviolet rays while applying a voltage to the liquid crystal alignment film and the liquid crystal layer includes, for example, applying an electric field between the electrodes installed on the substrate to apply an electric field to the liquid crystal alignment film and the liquid crystal layer. And applying ultraviolet rays while maintaining this electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p. The amount of ultraviolet irradiation is, for example, 1 to 60 J, preferably 40 J or less, and more preferably 20 J or less. It is preferable that the amount of ultraviolet irradiation be small because it is possible to suppress a decrease in reliability caused by the destruction of the liquid crystal and members constituting the liquid crystal display element, and the manufacturing efficiency is increased by reducing the ultraviolet irradiation time.

Thus, when ultraviolet rays are applied while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules are tilted is memorized by this polymer. The response speed of the obtained liquid crystal display element can be increased. In addition, when ultraviolet rays are applied while applying a voltage to the liquid crystal alignment film and the liquid crystal layer, the liquid crystal aligns from a side chain that vertically aligns the liquid crystal, a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group. Photoreactive side chain possessed by a polyimide precursor having at least one selected photoreactive side chain and at least one polymer selected from polyimide obtained by imidizing this polyimide precursor Since the photoreactive side chain of the polymer and the polymerizable compound react with each other, the response speed of the obtained liquid crystal display element can be increased.

The liquid crystal aligning agent is not only useful as a liquid crystal aligning agent for producing a vertical alignment type liquid crystal display element such as a PSA type liquid crystal display or an SC-PVA type liquid crystal display, but also by a rubbing process or a photo-alignment process. It can also be suitably used for applications of the liquid crystal alignment film to be produced.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

The polymerizable compound added to the liquid crystal aligning agent has the following structure.

RM7 is ADAMANATE X-DA manufactured by Idemitsu Kosan Co., Ltd.

RM8 is a DCP manufactured by Shin-Nakamura Chemical Co., Ltd.

(Synthesis of polymerizable compound RM1 (5,5- (biphenyl-4,4'-diylbis (oxy)) bis (pentane-5,1-diyl) bis (2-methacrylate))

To a 500 ml eggplant flask equipped with a condenser tube, 14.9 g (80.0 mmol) of biphenol, 35 g (167.0 mmol) of 5-bromopentyl acetate, 41.5 g (300 mmol) of potassium carbonate, and 250 ml of acetone were added to obtain a mixture. The reaction was carried out at 48 ° C. with stirring for 48 hours. After completion of the reaction, the reaction solution was poured into 600 ml of pure water to obtain 33.6 g of a white solid. The result of having measured this solid by NMR is shown below. From this result, it was confirmed that this white solid was a compound (RM1-A) represented by the following reaction formula. The yield was 95%.
¹ H NMR (CDCl ₃ ) δ: 1.57 (m, 4H), 1.74 (m, 4H), 1.86 (m, 4H), 2.06 (s, 6H), 4.02 (t, 4H), 4.12 (t, 4H) , 6.95 (d, 4H), 7.47 (d, 4H).

To a 1 L eggplant flask equipped with a condenser tube was added 250 ml of ethanol, 18.0 g (41 mmol) of the compound (RM1-A) obtained above, and 100 ml of 10% aqueous sodium hydroxide solution to obtain a mixture, and the mixture was stirred at a temperature of 85 ° C. for 5 hours. While reacting. After completion of the reaction, 500 ml of water and the reaction solution were added to a 1000 ml beaker and stirred for 30 minutes at room temperature, and then 80 ml of 10% HCl aqueous solution was added dropwise, followed by filtration to obtain 12.2 g of a white solid. The result of having measured this solid by NMR is shown below. From this result, it was confirmed that this white solid was a compound (RM1-B) represented by the following reaction formula. The yield was 83%.
¹ H NMR (DMSO-d6) δ: 1.46 (m, 8H), 1.71 (m, 4H), 3.41 (m, 4H), 3.98 (m, 4H), 4.39 (m, 2H), 6.96 (m, 4H ), 7.51 (m, 4H).

Tetrahydrofuran with 5.0 g (14.0 mmol) of the compound (RM1-B) obtained above together with 3.2 g of triethylamine (Et ₃ N) and a small amount of 2,6-di-tert-butyl-p-cresol (BHT) (THF) dissolved in 30 ml, stirred at room temperature, and cooled with a water bath, a solution of 3.3 g (32 mmol) of methacryloyl chloride in 20 ml of THF was added dropwise over 15 minutes. After dropping, the mixture was stirred for 30 minutes, and the water bath was removed and stirring was continued overnight while returning to room temperature. After completion of the reaction, the reaction solution was poured into 200 ml of pure water and filtered to obtain a white solid. This solid was dissolved in chloroform and precipitated with hexane (hexane / chloroform = 2/1) to obtain 2.6 g of a white solid. The result of having measured this solid by NMR is shown below. From this result, it was confirmed that this white solid was a polymerizable compound RM1 represented by the following reaction formula. The yield was 38%.
¹ H-NMR (CDCl ₃ ) δ: 1.56 (m, 4H), 1.74 (m, 4H), 1.82 (m, 4H), 1.97 (s, 6H), 4.03 (m, 4H), 4.20 (m, 4H ), 5.55 (m, 2H), 6.10 (m, 2H), 6.94 (d, 4H), 7.45 (d, 4H).

(Synthesis of polymerizable compound RM4)

(In the above formula, Ac represents CH ₃ CO—.)

In a 1 L four-necked flask, compound [A] (17.00 g, 79.2 mmol), compound [B] (50.00 g, 239 mmol), potassium carbonate (66.09 g, 239 mmol), N, N′-dimethylformamide (DMF) (200 g) was added and the atmosphere was replaced with nitrogen, followed by heating and stirring at 100 ° C. The reaction was traced by high performance liquid chromatography (HPLC). After confirming the completion of the reaction, the reaction solution was poured into distilled water (1.6 L), and the precipitated solid was filtered and washed with distilled water to obtain a crude product.
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 7.79-7.76 (4H, m), 6.96-6.94 (4H, m), 4.11-4.08 (8H, m), 2.06-1.94 (6H, m), 1.88-1.85 (4H, m), 1.75-1.69 (4H, m), 1.64-1.54 (4H, m).

Next, the obtained crude product was transferred to a reaction vessel, ethanol (350 g), 10 wt% aqueous sodium hydroxide solution (245 g) were added, and the mixture was heated and stirred at 85 ° C. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was poured into a 10 wt% hydrochloric acid aqueous solution (500 g), and the precipitated solid was filtered. 14.53 g of compound [C] was obtained by sequentially washing with distilled water, methanol and ethyl acetate and drying under reduced pressure (yield 51%).
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 7.79-7.75 (4H, m), 6.96-6.93 (4H, m), 4.10-4.04 (4H, m), 3.71-3.69 (4H, t), 1.90 -1.83 (4H, m), 1.70-1.53 (12H, m).

Next, the compound [C] obtained above (14.53 g, 37.6 mmol), triethylamine (5.33 g, 52.6 mmol) and THF (200 g) were charged into a 1 L four-necked flask, and the atmosphere was replaced with nitrogen. The reaction solution was cooled to 10 ° C. or lower. Thereto was added dropwise a solution of methacryloyl chloride (6.87 g, 52.6 mmol) in THF (25 g) while paying attention to heat generation. After completion of the dropwise addition, the reaction solution was returned to 23 ° C. and further stirred. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was poured into distilled water (1.7 L). An ethyl acetate / hexane mixed solvent was added thereto, and the aqueous layer was removed by a liquid separation operation. Further, the organic layer was washed with a 10 wt% potassium carbonate aqueous solution and brine three times in succession, and then the organic layer was dried with magnesium sulfate, followed by filtration and evaporation of the solvent with an evaporator to obtain a crude product of the polymerizable compound RM4. It was. The obtained crude product was washed with 2-propanol / hexane, and the obtained solid was dried under reduced pressure to obtain 13.1 g of a polymerizable compound RM4 (yield 66%).
¹ H-NMR (400 MHz, CDCl ₃ , δ ppm): 7.78-7.76 (4H, m), 6.95-6.93 (4H, m), 6.12-6.11 (2H, m), 5.57-5.56 (2H, m), 4.18 (4H, t), 4.06 (4H, t), 1.95-1.92 (6H, m), 1.92-1.76 (6H, m), 1.67-1.28 (6H, m).

<Preparation of liquid crystal aligning agent>
The abbreviations used in the preparation of the following liquid crystal aligning agents are as follows.
BODA: Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride DBA: 3,5-diamino Benzoic acid PCH: 1,3-diamino-4- [4- (4-heptylcyclohexyl) phenoxy] benzene BEM-S: 2- (methacryloyloxy) ethyl 3,5-diaminobenzoate represented by the following formula

NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

Moreover, the molecular weight measurement conditions of polyimide are as follows.
Apparatus: Room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd.
Column: Column made by Shodex (KD-803, KD-805)
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) 10ml / L)
Flow rate: 1.0 ml / min. Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight of about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (manufactured by Polymer Laboratories) Molecular weight about 12,000, 4,000, 1,000).

Moreover, the imidation ratio of polyimide was measured as follows. Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 by Kusano Kagaku) and add 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS (tetramethylsilane) mixture) Then, it was completely dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) manufactured by JEOL Datum. The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value. In the following formula, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and α is the proton of the NH group of the amic acid in the case of polyamic acid (imidation rate is 0%). This is the ratio of the number of reference protons to one.
Imidization rate (%) = (1−α · x / y) × 100

Example 1
BODA (17.01 g, 68.0 mmol), DBA (10.35 g, 68.0 mmol), PCH (19.41 g, 51.0 mmol), BEM-S (13.48 g, 51.0 mmol) were added to NMP (239. 75 g), and after reacting at 80 ° C. for 5 hours, CBDA (19.67 g, 100.3 mmol) and NMP (79.92 g) were added and reacted at 40 ° C. for 10 hours to obtain a polyamic acid solution. . After adding NMP to this polyamic acid solution (399 g) and diluting to 6% by mass, acetic anhydride (43.33 g) and pyridine (134.33 g) were added as imidation catalysts, and the mixture was reacted at 50 ° C. for 3 hours. This reaction solution was poured into methanol (5300 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 (A). The imidation ratio of this polyimide was 60%, the number average molecular weight was 20000, and the weight average molecular weight was 55000.

NMP (64.0 g) was added to the obtained polyimide powder (A) (6.0 g) and dissolved by stirring at 50 ° C. for 12 hours. BCS (30.0g) was added to this solution, and the liquid crystal aligning agent (B) was obtained by stirring at 50 degreeC for 5 hours.

Further, 0.06 g of polymerizable compound RM2 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and the mixture is dissolved by stirring for 3 hours at room temperature. (B1) was prepared.

(Example 2)
0.06 g of polymerizable compound RM3 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and the mixture is stirred and dissolved at room temperature for 3 hours to obtain the liquid crystal aligning agent (B2). Prepared.

(Example 3)
0.06 g of polymerizable compound RM4 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and dissolved by stirring at room temperature for 3 hours. Prepared.

Example 4
0.06 g of polymerizable compound RM5 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and dissolved by stirring at room temperature for 3 hours. Prepared.

(Example 5)
0.06 g of polymerizable compound RM6 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and dissolved by stirring at room temperature for 3 hours. Prepared.

(Example 6)
0.06 g of polymerizable compound RM7 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), and the mixture is stirred and dissolved at room temperature for 3 hours. Prepared.

(Example 7)
0.06 g of polymerizable compound RM8 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B), dissolved by stirring at room temperature for 3 hours, and the liquid crystal aligning agent (B7) is added. Prepared.

(Comparative Example 1)
0.06 g of polymerizable compound RM1 (10% by mass with respect to the solid content) is added to 10.0 g of the liquid crystal aligning agent (B) and dissolved by stirring for 3 hours at room temperature. Prepared.

<Production of liquid crystal cell>
(Example 8)
Using the liquid crystal aligning agent (B1) obtained in Example 1, a liquid crystal cell was prepared according to the procedure shown below. The liquid crystal aligning agent (B1) obtained in Example 1 was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100 μm × 300 μm and a line / space of 5 μm was formed, After drying for 90 seconds on this hot plate, baking was performed in a hot air circulation oven at 200 ° C. for 30 minutes to form a liquid crystal alignment film having a thickness of 100 nm.

Moreover, after spin-coating the liquid crystal aligning agent (B1) on the ITO surface in which the electrode pattern is not formed and drying for 90 seconds on a hot plate at 80 ° C., baking is performed in a hot air circulation oven at 200 ° C. for 30 minutes, A liquid crystal alignment film having a thickness of 100 nm was formed.

After spraying a 6 μm bead spacer on the liquid crystal alignment film of one of the two substrates, a sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was printed thereon. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was faced inward and bonded to the previous substrate, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-6608 (trade name, manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and was subjected to Isotropic treatment (realignment treatment of liquid crystal by heating) in an oven at 120 ° C., thereby producing a liquid crystal cell.

The response speed immediately after production of the obtained liquid crystal cell was measured by the following method. After that, with a voltage of 20 Vp-p applied to the liquid crystal cell, 20 J UV irradiation through a 313 nm band pass filter was applied from the outside of the liquid crystal cell. Thereafter, the response speed was measured again, and the response speed before and after UV irradiation was compared. Table 2 shows the results of the response speed immediately after the production of the liquid crystal cell (denoted as “initial” in the table) and after UV irradiation (denoted as “after UV” in the table).

"Response speed measurement method"
First, a liquid crystal cell was arranged between a pair of polarizing plates in a measuring device configured in the order of a backlight, a set of polarizing plates in a crossed Nicol state, and a light amount detector. At this time, the ITO electrode pattern in which the line / space was formed was at an angle of 45 ° with respect to the crossed Nicols. Then, a rectangular wave with a voltage of ± 4 V and a frequency of 1 kHz is applied to the liquid crystal cell, and the change until the luminance observed by the light quantity detector is saturated is captured by an oscilloscope, and the luminance when no voltage is applied is obtained. A voltage of 0% and ± 4 V was applied, the saturated luminance value was set to 100%, and the time taken for the luminance to change from 10% to 90% was defined as the response speed.

Example 9
The response speed before and after UV irradiation was compared by performing the same operation as in Example 8 except that the liquid crystal aligning agent (B2) was used instead of the liquid crystal aligning agent (B1).

(Example 10)
Except for using the liquid crystal aligning agent (B3) instead of the liquid crystal aligning agent (B1), the same operation as in Example 8 was performed, and the response speeds before and after UV irradiation were compared.

(Example 11)
Responsive speed before and after UV irradiation was carried out in the same manner as in Example 8 except that the firing temperature was changed from 200 ° C. to 140 ° C. and the liquid crystal aligning agent (B4) was used instead of the liquid crystal aligning agent (B1). Compared.

(Example 12)
Responsive speed before and after UV irradiation was carried out in the same manner as in Example 8 except that the firing temperature was changed from 200 ° C. to 140 ° C. and the liquid crystal aligning agent (B5) was used instead of the liquid crystal aligning agent (B1). Compared.

(Example 13)
Responsive speed before and after UV irradiation was carried out in the same manner as in Example 8 except that the firing temperature was changed from 200 ° C. to 140 ° C. and the liquid crystal aligning agent (B6) was used instead of the liquid crystal aligning agent (B1). Compared.

(Example 14)
Responsive speed before and after UV irradiation was carried out in the same manner as in Example 8 except that the firing temperature was changed from 200 ° C. to 140 ° C. and the liquid crystal aligning agent (B7) was used instead of the liquid crystal aligning agent (B1). Compared.

(Comparative Example 2)
Except for using the liquid crystal aligning agent (B8) instead of the liquid crystal aligning agent (B1), the same operation as in Example 8 was performed to compare the response speed before and after UV irradiation.

<Storage stability test>
(Example 15)
Using the liquid crystal aligning agent (B1) obtained in Example 1, a storage stability test of the liquid crystal aligning agent was performed according to the procedure shown below. The liquid crystal aligning agent (B1) obtained in Example 1 was stored in a freezer maintained at −20 ° C., and the liquid crystal aligning agent after 24 hours was observed. The results are shown in Table 2, assuming that the polymerizable compound added to the liquid crystal aligning agent is dissolved, “dissolved”, and the case where the polymerizable compound is precipitated is “deposited”.

(Example 16)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B2) was used instead of the liquid crystal aligning agent (B1).

(Example 17)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B3) was used instead of the liquid crystal aligning agent (B1).

(Example 18)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B4) was used instead of the liquid crystal aligning agent (B1).

(Example 19)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B5) was used instead of the liquid crystal aligning agent (B1).

(Example 20)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B6) was used instead of the liquid crystal aligning agent (B1).

(Example 21)
A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B7) was used instead of the liquid crystal aligning agent (B1).
(Comparative Example 3)

A storage stability test was performed in the same manner as in Example 15 except that the liquid crystal aligning agent (B8) was used instead of the liquid crystal aligning agent (B1).

As a result, as shown in Table 2, the response speeds of all of Examples 8 to 14 were very high. In addition, the polymerizable compounds having a mother nucleus represented by the above formulas (i-1) to (i-3), which are specific polymerizable compounds, or represented by the above formulas (ii-1) to (ii-3) In Examples 15 to 21 containing a polymerizable compound having a mother nucleus, the polymerizable compound did not precipitate even when stored frozen, but in Comparative Example 3 containing another polymerizable compound, it was precipitated. Has occurred.

Therefore, a polymer such as polyimide having a photoreactive side chain, a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), and the above formula (ii-1) to By using a liquid crystal aligning agent containing a polymerizable compound having a mother nucleus represented by (ii-3), the liquid crystal aligning agent can make the response speed very fast and has excellent storage stability. It was confirmed that

Further, in the same manner as in Examples 1 to 6 and Comparative Example 1, except that the mass ratio NMP / BCS between NMP and BCS at the time of obtaining the liquid crystal aligning agent (B) was changed to the values shown in Table 3 below, A liquid crystal aligning agent having a solvent composition was prepared. In addition, the mixture ratio of the polymeric compound of each liquid crystal aligning agent is 10 mass% with respect to solid content in any polymeric compound similarly to the above.

Table 3 shows the results of a storage stability test performed on the liquid crystal aligning agents with different solvent compositions by the same method as described above. As a result, as shown in Table 3, a polymerizable compound having a mother nucleus represented by the above formulas (i-1) to (i-3), or represented by the above formulas (ii-1) to (ii-3) In the liquid crystal aligning agent containing a polymerizable compound having a mother nucleus, the polymerizable compound did not precipitate even when stored frozen in any solvent composition, but contained RM1, which is another polymerizable compound In the liquid crystal aligning agent, precipitation occurred.

Claims

A polyimide precursor having a side chain for vertically aligning liquid crystal and a photoreactive side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group And at least one polymer selected from polyimides obtained by imidizing this polyimide precursor,
Having at least one kind of mother nucleus selected from the following formulas (i-1) to (i-3) and one or more terminals having a photopolymerization or photocrosslinking group, wherein the photopolymerization or photocrosslinking group comprises: A polymerizable compound bonded to the mother nucleus directly or via a bonding group;
A liquid crystal aligning agent characterized by having a solvent.
The liquid crystal aligning agent according to claim 1, wherein the polymerizable compound is selected from the following formulas.

(Wherein R 31 is represented by a single bond or —R 35 O—, R 35 is a linear alkylene group having 1 to 10 carbon atoms, and R 32 is represented by a single bond or —OR 36 —. R 36 is a linear alkylene group having 1 to 10 carbon atoms, and R 33 and R 34 are each independently a hydrogen atom or a methyl group.)
A polyimide precursor having a side chain for vertically aligning liquid crystal and a photoreactive side chain containing at least one selected from a methacryl group, an acrylic group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group And at least one polymer selected from polyimides obtained by imidizing this polyimide precursor,
Having at least one mother nucleus selected from the following formulas (ii-1) to (ii-3) and a group capable of photopolymerization or photocrosslinking at one or more terminals, the photopolymerization or photocrosslinkable group comprising: A polymerizable compound bonded to the mother nucleus by an oxyalkylene group;
A liquid crystal aligning agent characterized by having a solvent.
The liquid crystal aligning agent according to claim 3, wherein the polymerizable compound is selected from the following formulas.

(In the formula, R 41 is represented by a single bond or —R 45 O—, R 45 is a linear alkylene group having 1 to 10 carbon atoms, and R 42 is represented by a single bond or —OR 46 —. R 46 is a linear alkylene group having 1 to 10 carbon atoms, and R 43 and R 44 are each independently a hydrogen atom or a methyl group.)
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the photoreactive side chain contains a group selected from the following formula (I):

(In the formula, R 11 is H or a methyl group.)
The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the photopolymerizable or photocrosslinking group is selected from the following formula (II).

(Wherein R 12 is H or an alkyl group having 1 to 4 carbon atoms, and Z 1 is a divalent alkyl group optionally having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms. Z 2 is a monovalent aromatic ring or heterocyclic ring optionally substituted by an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms.
A liquid crystal alignment film obtained by applying the liquid crystal aligning agent according to any one of claims 1 to 6 to a substrate and baking it.
A liquid crystal layer is provided in contact with a liquid crystal alignment film obtained by applying the liquid crystal aligning agent according to any one of claims 1 to 6 to a substrate and firing the substrate, and ultraviolet rays are applied while applying a voltage to the liquid crystal layer. A liquid crystal display element comprising a liquid crystal cell produced by irradiation.
A liquid crystal layer is provided in contact with a liquid crystal alignment film obtained by applying the liquid crystal aligning agent according to any one of claims 1 to 6 to a substrate and firing the substrate, and ultraviolet rays are applied while applying a voltage to the liquid crystal layer. A method for producing a liquid crystal display element, wherein a liquid crystal cell is produced by irradiation.