WO2020054797A1

WO2020054797A1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element, and diamine and production method therefor, and polymer

Info

Publication number: WO2020054797A1
Application number: PCT/JP2019/035868
Authority: WO
Inventors: 尚宏野田; 一世三宅
Original assignee: 日産化学株式会社
Priority date: 2018-09-14
Filing date: 2019-09-12
Publication date: 2020-03-19
Also published as: JP2023171809A; KR20210057137A; TWI828752B; TW202026406A; JPWO2020054797A1; CN112703447A; JP7381994B2

Abstract

This liquid crystal alignment agent contains at least one polymer selected from polyimide precursors including a structural unit represented by formula [3-1], and polyimides that are imide compounds of the polyimide precursors. In the formula, V⁰ represents a tetravalent organic group derived from a tetracarboxylic acid derivative, W¹ represents a divalent organic group represented by formula [2-1], and R³ and R⁴ each independently represent a hydrogen atom or an alkyl group having 1-5 carbon atoms. In the formula, Y¹ represents a tetravalent organic group having an alicyclic structure, X¹ and X² each represent a divalent organic group, Z¹ and Z² each independently represent a single bond, -NH-, or -O-, R¹ and R² each independently represent an alkyl group having 1-5 carbon atoms, and * represents a bonding site.

Description

Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element, diamine, method for producing the same, and polymer

The present invention relates to a novel liquid crystal aligning agent and a liquid crystal aligning film, a liquid crystal display device, a novel diamine, a method for producing the same, and a polymer.

Currently, liquid crystal display elements are widely used as display units for personal computers, mobile phones, television receivers, and the like. The liquid crystal display element is, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, a liquid crystal alignment film for controlling the alignment of liquid crystal molecules in the liquid crystal layer, A thin film transistor (TFT) for switching an electric signal supplied to the pixel electrode is provided. Of these, the liquid crystal alignment film is formed by applying a polyimide-based liquid crystal alignment agent comprising a solution of a polyamic acid (also referred to as “polyamic acid”) as a polyimide precursor or a polyimide as an imidized product to a substrate. It is made by filming.

In recent years, the performance of liquid crystal display elements has been increased, the area has been increased, the power consumption of display devices has been reduced, and in addition, they have been used in various environments and the characteristics required for liquid crystal alignment films are severe. It has become. Therefore, various techniques such as changing the structure of polyamic acid or polyimide, adding a blend or additive of polyamic acid or polyimide having different characteristics, and improving the liquid crystal alignment and electrical characteristics, as well as controlling the pretilt angle, etc. Is being done.

適用 As an example of a technique for improving the properties of the liquid crystal alignment film, application of a diamine having a novel structure, which is a raw material of a polyamic acid, has been proposed. For example, Patent Literature 1 discloses a liquid crystal aligning agent containing a diamine having a novel structure and an aliphatic tetracarboxylic acid derivative. By using the liquid crystal aligning agent, a voltage holding ratio is excellent, and a charge A liquid crystal display element capable of reducing accumulation can be provided.

However, the characteristics required for the liquid crystal alignment film are becoming stricter with the high performance of the liquid crystal display element, and it is difficult to satisfy all the required characteristics only by the conventional technology.

On the other hand, as a general method of aligning liquid crystals, a rubbing method in which a polymer film such as polyimide is applied on a substrate such as glass and the surface thereof is rubbed in a predetermined direction with fibers such as nylon or polyester is used. . However, the rubbing method generates fine dust and electrostatic discharge due to friction between the fiber and the polymer film, and may cause a serious problem when manufacturing a liquid crystal panel.

Therefore, in order to solve the problem of the rubbing method, there is known a photo-alignment method in which the polymer film has no friction and anisotropy is induced by light irradiation for aligning the liquid crystal. In the photo-alignment method, a polymer contained in a liquid crystal alignment film undergoes a photo-reaction such as a photo-decomposition reaction or a photo-dimerization reaction by irradiation with polarized ultraviolet light to fix the alignment direction of the liquid crystal. Such a photo-alignment method employs an IPS method (In-Plane Switching g) or an FFS method (Fringe Field Switching), which is a lateral electric field driving method, while demands for higher definition and higher quality of a liquid crystal display element are increasing. Application to liquid crystal display elements has been performed (for example, see Patent Document 2). In recent years, a method of combining the IPS method with the PSA method has been developed in order to further improve the alignment ability.

However, polyimide used in the photo-alignment method generally has poor solvent solubility, and it is difficult to apply polyimide directly in the process of forming an alignment film by applying the polyimide in a solution state. For this reason, a precursor such as polyamic acid or polyamic acid ester having excellent solubility is applied, a polyimide is formed through a heat treatment process, and then the film is oriented by irradiating light. A lot of energy is required to obtain alignment. Therefore, it is difficult to actually secure the productivity, and there is a restriction that a further heat treatment step is required to obtain the alignment stability after light irradiation.

WO 2010/053128 JP 2013-080193 A

In view of such circumstances, the present invention provides a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal display element, a diamine, a method for producing the same, and a polymer using a novel diamine for improving the characteristics of a liquid crystal display element. The purpose is to do.

An embodiment of the present invention which solves the above-mentioned problem is a liquid crystal alignment containing a polyimide precursor containing a structural unit represented by the following formula [3-1] and at least one polymer selected from polyimide which is an imide compound thereof. In the agent.

In the formula, V ⁰ is a tetravalent organic group derived from a tetracarboxylic acid derivative, W ¹ is a divalent organic group represented by the following formula [2-1], and R ³ and R ⁴ are Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

In the formula, Y ¹ is a tetravalent organic group having an alicyclic structure, X ¹ and X ² are divalent organic groups, and Z ¹ and Z ² are each independently a single bond, —NH— or —O—, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms, and * represents a bonding site.

According to the present invention, it is possible to provide a novel liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element, and a novel diamine, a method for producing the same, and a polymer for improving the characteristics of the liquid crystal display element.

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

The liquid crystal aligning agent of the present invention includes at least one polymer selected from a polyimide precursor containing a structural unit represented by the following formula [3-1] and a polyimide that is an imide compound thereof (hereinafter, also referred to as a specific polymer A). ). More specifically, the specific polymer A and the organic solvent are included.

In the above, the structure of the formula [2-1] is a divalent group derived from a diamine represented by the following formula [1] (hereinafter also referred to as the diamine of the present invention). explain. Specific examples and preferred structures of Y ¹ , X ¹ , X ² , Z ¹ , Z ² , R ¹ and R ² in the formula [2-1] are the specific examples described in the description of the formula [1]. Or the preferred structure. In the formula [3-1], W ¹ may be a single type in the same polymer as long as it is a divalent organic group represented by the formula [2-1], two or more kinds are mixed May be.

<Diamine>
The diamine of the present invention is represented by the following formula [1].

In the formula, Y ¹ is a tetravalent organic group having an alicyclic structure, X ¹ and X ² are divalent organic groups, and Z ¹ and Z ² are each independently a single bond, —NH— or —O—, and R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-alkyl group. Examples include a pentyl group, an isopentyl group, an s-pentyl group, and a t-pentyl group. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, a 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group and the like. Examples of the alkynyl group having 2 to 5 carbon atoms include ethynyl group. , 1-propynyl, 2-propynyl (propargyl), 3-butynyl, pentynyl and the like. Among these, from the viewpoint of liquid crystal alignment, R ¹ and R ² are preferably a methyl group or an ethyl group, and more preferably a methyl group.

X ¹ and X ² are divalent organic groups, and their structures are not particularly limited, but are preferably organic groups having 30 or less carbon atoms.
Further, from the viewpoint of liquid crystal alignment, it is preferable to have a phenylene group.
A particularly preferred structure includes a divalent group represented by the following formula [2-2].

In the formula, X ³ and X ^{5 each} independently represent a phenylene group which may have a substituent; X ⁴ represents a divalent group having 10 or less carbon atoms; L ¹ and L ² independently represent N1, n2 independently represent 0 or 1, and * 1, * 2 represent a binding site. * 1, * 2, one in ^{Z 1} or ^{Z 2,} and the other is bonded to the nitrogen atom.

Specific examples of the substituent which the phenylene group of X ³ and X ⁵ may have include, for example, an alkyl group and an alkoxy group having 1 to 5 carbon atoms, a fluoroalkyl group and a fluoroalkoxy group having 1 to 5 carbon atoms, A fluorine atom and the like can be mentioned.

Preferred specific examples of X ⁴ include divalent groups selected from the following (a) to (d).
(A): a group obtained by removing two hydrogen atoms from a hydrocarbon having 1 to 10 carbon atoms.
(B): a group having a structure in which a linking group selected from —O—, —S—, and —SO ₂ — is sandwiched between one or more carbon-carbon bonds of (a).
(C): a group having a structure in which one or more carbon atoms of the above (a) or (b) are replaced with a silicon atom or a nitrogen atom.
(D): a group having a structure in which one or more methylene groups (—CH ₂ —) of the above (a) to (c) are replaced with a carbonyl group (—CO—).
The “hydrocarbon” of the above (a) may be a saturated hydrocarbon or an unsaturated hydrocarbon, may have a linear or branched chain structure, and may have a cyclic structure or a cyclic structure. It may be a structure including a structure.
In the above (c), when a structure in which a carbon atom is replaced with a nitrogen atom is used, the original carbon atom is limited to a structure in which a hydrogen atom is bonded, and in the structure after replacement with a nitrogen atom, Hydrogen atoms shall be deleted.

More preferred structures of X ¹ and X ² include the structures represented by (X-1) to (X-11).

(N represents an integer of 1 to 6.)

In the above formula [1], the structure of the tetravalent organic group having an alicyclic structure is not particularly limited, but specific examples include the following formulas [Y ¹ -1] to [Y ¹ -20] Can be mentioned.

In the formulas [Y ¹ -1] to [Y ¹ -4], R ⁵ to R ²⁵ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, An alkenyl group having 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom or a phenyl group, which may be the same or different. From the viewpoint of liquid crystal alignment, R ⁵ to R ²⁵ are preferably a hydrogen atom, a halogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

Among them, the formula [Y ¹ -1] is preferable, and specific structures of the formula [Y ¹ -1] are represented by the following formulas [Y ¹ -1-1] to [Y ¹ -1-6]. Structure. The structure represented by the following formula [Y ¹ -1-1] is particularly preferable from the viewpoint of the liquid crystal alignment property of the liquid crystal aligning agent and the sensitivity of the photoreaction.

Hereinafter, a method for synthesizing a diamine will be described.

The method for synthesizing the diamine of the formula [1] is to use a dialkyl tetracarboxylate having an alicyclic structure represented by the following formula (11) as a starting material, and via an isocyanate compound of the formula (12) or an isocyanate compound. And a first step of obtaining an amine derivative of the formula (13).

A method for obtaining an isocyanate compound of the formula (12) from a tetraalkyl dialkyl ester having an alicyclic structure of the formula (11) is obtained by converting a carboxylic acid azide (—COON ₃ ) from a carboxylic acid (—COOH) of the formula (11). Isocyanate compound (—NCO) via a transfer reaction such as Curtius rearrangement or Schmidt rearrangement, or a hydroxyamide derivative (—CONOHH, —CONHOTs; Ts is a tosyl group (p -Toluenesulfonic acid group) to produce an isocyanate compound via a Lossen rearrangement. The isocyanate compound thus formed can be converted to an amine derivative of the formula (13) by reacting with water, tert-butyl alcohol, or the like, and such a compound is directly formed from the compound of the formula (11). be able to. When R ³¹ and R ³² in the compound of the formula (13) are hydrogen atoms, that is, when water is reacted with the diisocyanate compound of the formula (12), for example, di-tert-butyl dicarbonate or 4-nitrobenzyl chloride By reacting with an amino-protecting reagent such as benzyl chloroformate or fluorenylmethyl chloroformate to form an amino-protected product, purification becomes easier, and as a result, synthesis may be easier.

In the formulas (11) to (13), Y ¹ is a divalent organic group having an alicyclic structure, and R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms. . In Formula (13), R ³¹ and R ³² represent a hydrogen atom or an amino-protecting group.
Here, the protecting groups for the amino group represented by R ³¹ and R ³² include a benzyl group, a nitrobenzyl group, a CBz group (benzyloxycarbonyl group), a Boc group (tert-butoxycarbonyl group), and an Fmoc group (9 -Fluorenylmethyloxycarbonyl group), but is not limited thereto.

The method for synthesizing a diamine compound according to the present invention is characterized in that the isocyanate compound of the formula (12) has HZ ² —X ² —N ⁰ (Z ² represents —O— or —NH—, and X ² represents a divalent organic group). And N ⁰ represents a group that can be converted to an amino group. Specific examples and preferred structures of X ² are the same as the specific examples and preferred structures described in the description of Formula [1]. A method in which an amine compound or an alcohol compound is reacted, or an amine compound of the formula (13) is converted into an active amine compound through a step such as deprotection if necessary, and Cl—C (＝ O) —X ² — An acid chloride compound represented by N ⁰ (X ² represents a divalent organic group and N ⁰ represents a group convertible to an amino group) or OCN-X ² -N ⁰ (X ² represents a divalent organic group) And N ⁰ represents a group that can be converted to an amino group.) A chloroformate derivative represented by a cyanate compound, Cl—C (＝ O) —OX ² —N ⁰ (X ² represents a divalent organic group, and N ⁰ represents a group that can be converted to an amino group) A second step of obtaining a diamine compound precursor of the following formula (14) by reacting N ⁰ is a group that can be converted into an amino group, and examples thereof include a nitro group and a protected amino group. The protected amino group is not particularly limited as long as it can be easily deprotected and converted to an amino group. One hydrogen of the amino group may be replaced with a benzyl group, a nitrobenzyl group, a CBz group (a benzyloxycarbonyl group). ), A Boc group (tert-butoxycarbonyl group) and a group substituted with an Fmoc group (9-fluorenylmethyloxycarbonyl group).

N ⁰ represents a nitro group or a protected amino group.

Specific examples of the compound of the formula (14) include the following formulas (15) to (17). Here, the compound of the formula (15) is obtained by adding a compound having an amino group, a nitro group or a protected amino group to the isocyanate compound of the formula (12) (for example, represented by H ₂ N—X ² —N ^0). Compound). Further, the compound of the formula (16) is obtained by adding a compound having a hydroxyl group, a nitro group or a protected amino group to the isocyanate compound of the formula (12) (for example, a compound represented by HO—X ² —N ⁰ ). It is produced by the reaction. Further, the compound of the formula (17) is obtained by adding an acid chloride compound having a nitro group or a protected amino group to the diamide compound of the formula (13) or a carboxylic acid having a nitro group or a protected amino group in the presence of a suitable condensing agent. It is produced by the reaction.

The method for synthesizing a diamine compound of the present invention includes a third step of converting a nitro group or a protected amino group of the compound of the formula (14) into an amino group, thereby producing a diamine compound of the formula (1). Can be. In the present invention, the first step and the second step can be performed, respectively, but the first step and the second step can be performed continuously or as one step.

<Specific polymer A>
The specific polymer A of the present invention is at least one polymer selected from a polyimide precursor containing a structural unit represented by the following formula [3-1] and a polyimide that is an imide compound thereof, And a tetracarboxylic acid derivative.

In the formula, R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, and s. -Pentyl group, t-pentyl group and the like. Examples of the alkenyl group having 2 to 5 carbon atoms include, for example, vinyl group, allyl group, 1-propenyl group, 1-butenyl group, 2-butenyl group, 3- Examples thereof include a butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, and a 4-pentenyl group. Examples of the alkynyl group having 2 to 5 carbon atoms include an ethynyl group, a 1-propynyl group, -Propynyl (propargyl) group, 3-butynyl group, pentynyl group and the like. Among them, R ³ and R ⁴ are preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group, from the viewpoint of facilitating the progress of the imidization reaction upon heating.

V ⁰ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. In addition, V ⁰ is determined by the degree of required properties such as solubility of a polymer in a solvent, applicability of a liquid crystal aligning agent, liquid crystal alignment when forming a liquid crystal alignment film, voltage holding ratio, and accumulated charge. One type may be selected as appropriate, and one type may be used in the same polymer, or two or more types may be mixed.

Examples of the tetracarboxylic acid derivative include a tetracarboxylic dianhydride, a tetracarboxylic dihalide compound, a tetracarboxylic dialkyl ester compound, and a tetracarboxylic dialkyl ester dihalide compound. For example, the tetracarboxylic dianhydride from which V ⁰ in formula [3-1] is derived includes a compound represented by the following formula [5].

Specific examples of V ^{0 in} the formulas [3-1] and [5] include a tetravalent organic group having an alicyclic structure shown as a specific example of Y ^{1 in} the formula [1], and the following formula [ Examples thereof include tetravalent organic groups represented by V-1] to [V-16], but the invention is not limited thereto.

特定 The specific polymer A of the present invention may contain a structural unit other than the structural unit represented by the formula [3-1]. For example, as a structural unit other than the formula [3-1], a structural unit represented by the following formula [3-2] can be given.

In the formula, V ⁰ is a tetravalent organic group derived from a tetracarboxylic acid derivative, W ² is a divalent organic group other than the structure represented by the formula [2-1], and R ³ , R ⁴ , A ¹ and A ² each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
Specific examples and preferred structures of V ⁰ , R ³ , and R ⁴ are the same as those of formula [3-1]. However, in the embodiment of the present invention, the specific structure of V ⁰ , R ³ , and R ⁴ is not necessarily the same between the structural unit represented by the formula [3-1] and the structural unit represented by the formula [3-2]. It doesn't have to be the same.
Specific examples of the alkyl group having 1 to 5 carbon atoms for A ¹ and A ² include the specific examples shown for R ³ and R ⁴ . From the viewpoint of liquid crystal alignment, A ¹ and A ² are preferably a hydrogen atom or a methyl group.

W ² is a divalent organic group derived from a diamine other than the diamine represented by the formula [1] (hereinafter, also referred to as other diamine), and has a structure other than the structure represented by the formula [2-1]. The structure is not particularly limited as long as it is a divalent organic group. Other diamines include compounds represented by the following formula [2-2].

W ² , A ¹ and A ² each represent the same as in the formula [3-2].

Hereinafter, specific examples of the structure of the W ^2, but the present invention is not limited thereto.

The Boc group in the formula represents a tert-butoxycarbonyl group shown below.

When the specific polymer A includes a structural unit of the formula [3-1] and a structural unit of the formula [3-2] at the same time, the structural unit of the formula [3-1] is represented by the formula [3-1] It is preferably at least 10 mol%, more preferably at least 20 mol%, particularly preferably at least 30 mol%, based on the total of the structural units and the structural unit of the formula [3-2].

The molecular weight of the specific polymer A is determined, when a liquid crystal alignment film is obtained from a liquid crystal alignment agent containing the polymer, the strength of the coating film (liquid crystal alignment film), workability in forming the coating film, and the coating film. In consideration of the homogeneity of the polymer, the weight-average molecular weight measured by GPC (Gel Permeation Chromatography) is preferably 2,000 to 500,000, more preferably 5,000 to 300,000. More preferably, the molecular weight is from 000 to 100,000.

<Method for producing polymer>
Next, a main method for producing a polymer containing a liquid crystal alignment agent of the present invention will be described. Note that the method described below is a manufacturing example and is not limited to this.

For example, when the specific polymer A is a polyamic acid, such a polymer is obtained by reacting a tetracarboxylic dianhydride, which is a tetracarboxylic acid derivative, with a diamine component. In order to obtain a polyamic acid by this reaction, a known synthesis method can be used. The synthesis method is a method of reacting a tetracarboxylic dianhydride with a diamine component in an organic solvent. Such a method is advantageous in that it proceeds relatively easily in an organic solvent and does not generate by-products.

The organic solvent used in the above reaction is not particularly limited as long as the produced polyamic acid (polymer) is dissolved, and examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2. -Pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethylamyl ketone, Methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carb Tall, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol Monoacetate, diethylene glycol dimethyl ether, dipropylene 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 butyi Rate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, acetic acid Methyl, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, 3-methoxy Methyl propionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy -4-Methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like. These may be used alone or in combination. Further, even if the solvent does not dissolve the polyamic acid (polymer), the solvent may be mixed with the above-mentioned organic solvent as long as the generated polyamic acid does not precipitate. In particular, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the generated polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

When reacting a tetracarboxylic dianhydride and a diamine component in an organic solvent, a solution obtained by dispersing or dissolving the diamine component in the organic solvent is stirred, and the tetracarboxylic dianhydride as it is or in the organic solvent. Dispersion or dissolution method of addition, tetracarboxylic acid dianhydride dispersed or dissolved in organic solvent, diamine component added to solution, tetracarboxylic acid dianhydride and diamine component alternately added, etc. And any of these methods may be used. When the tetracarboxylic dianhydride or the diamine 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 individually reacted low molecular weight compounds. May be mixed to give a high molecular weight product.

重 The temperature of the polycondensation at this time can be selected from any temperature in the range of -20 ° C to 150 ° C, but is preferably in the range of -5 ° C to 100 ° C. In addition, the polycondensation reaction can be performed at any concentration, but if the concentration is too low, it is difficult to obtain a polymer having a high molecular weight, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is performed. Therefore, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction may be performed at a high concentration, and then an organic solvent may be added.

In the polymerization reaction of the polyamic acid, the ratio of the total number of moles of tetracarboxylic dianhydride to the total number of moles of diamine component (total number of moles of tetracarboxylic dianhydride / total number of moles of diamine component) is 0. It is preferably from 0.8 to 1.2. As in the ordinary polycondensation reaction, the molecular weight of the generated polyamic acid increases as the molar ratio approaches 1.0.

When the specific polymer A is a polyamic acid ester, the reaction between the tetracarboxylic diester dichloride and the diamine component or the reaction between the tetracarboxylic diester and the diamine component in the presence of a suitable condensing agent or a base. Can be obtained by Alternatively, it can also be obtained by synthesizing a polyamic acid in advance by the above method and esterifying the carboxylic acid in the amic acid using a polymer reaction.

Specifically, for example, a tetracarboxylic diester dichloride and a diamine are mixed with each other 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 minute. By reacting for 4 to 4 hours, a polyamic acid ester can be synthesized.

ピリジン As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable since the reaction proceeds gently. The amount of the base to be added is preferably 2 to 4 moles with respect to the tetracarboxylic diester dichloride, from the viewpoint of easy removal and easy production of a high molecular weight compound.

When polycondensation of a tetracarboxylic acid diester and a diamine component is carried out in the presence of a condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride may be used as a base. N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium Tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxa Diphenyl zolyl) phosphonate, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl It can be used 4-methoxy mol ho potassium chloride n- hydrate.

In addition, in the above method using a condensing agent, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The amount of the Lewis acid to be added is preferably 0.1 to 1.0 times the molar amount of the diamine or tetracarboxylic acid diester to be reacted.

The solvent used in the above reaction can be the same as the solvent used when synthesizing the polyamic acid described above, but N-methyl-2-pyrrolidone, γ -Butyrolactone is preferred, and these may be used alone or in combination of two or more. The concentration at the time of the synthesis, from the viewpoint that the precipitation of the polymer is unlikely to occur and the high molecular weight is easily obtained, in the reaction solution of the diamine component with the tetracarboxylic acid derivative such as tetracarboxylic diester dichloride or tetracarboxylic diester. The total concentration is preferably 1% by mass to 30% by mass, more preferably 5% by mass to 20% by mass. Further, in order to prevent hydrolysis of the tetracarboxylic diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent outside air from being mixed in a nitrogen atmosphere.

In the case where the specific polymer A is a polyimide, the specific polymer A is obtained by subjecting a polyamic acid or a polyamic acid ester as a polyimide precursor to ring-closing imidization. In this polyimide, the ring closure ratio (imidation ratio) does not necessarily have to be 100%, and can be arbitrarily adjusted according to the application and purpose.

Examples of the method for imidizing the polyamic acid include thermal imidization in which a solution of the polyamic acid is directly heated and catalytic imidization in which a catalyst is added to the polyamic acid solution.

温度 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 performed while removing water generated by the imidization reaction out of the system.

触媒 Catalytic imidation of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of polyamic acid and stirring at −20 ° C. to 250 ° C., preferably 0 ° C. 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 of the amic acid group. Preferably it is 3 to 30 mole times. 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 causing the reaction to proceed. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferable because purification after the reaction is easy. The imidation rate by the catalytic imidization can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

ポリイミド In addition, as described above, the polyimide can also be obtained by heating the polyamic acid ester at a high temperature to promote dealcoholation and to close the ring.

In addition, polyamic acid, a polyimide precursor such as polyamic acid ester, and a polyamic acid, a polyamic acid ester, and a polyimide that are generated from a polyimide reaction solution are collected, the reaction solution is poured into a poor solvent to precipitate. I just need. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water and the like. After the polyimide precursor or the polyimide which has been put into the poor solvent and precipitated is recovered by filtration, it can be dried at normal temperature or reduced pressure at normal temperature or by heating. Further, by repeating the operation of re-dissolving the precipitated and recovered polyimide precursor or polyimide in an organic solvent and re-precipitating and recovering 2 to 10 times, impurities in the polymer can be reduced. In this case, examples of the poor solvent include alcohols, ketones, and hydrocarbons. It is preferable to use three or more kinds of poor solvents selected from these, because the purification efficiency is further increased.

The polymer of the present invention thus obtained can be dissolved in a predetermined organic solvent and used as a liquid crystal aligning agent. This liquid crystal alignment agent is used for a liquid crystal alignment film for controlling the alignment of liquid crystal molecules in a liquid crystal layer in a liquid crystal display device. Hereinafter, the liquid crystal aligning agent containing the polymer of the present invention will be described.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention contains at least one polymer selected from the specific polymer A.

However, all of the polymers contained in the liquid crystal aligning agent of the present invention may be the specific polymer A of the present invention, or the specific polymer A of the present invention contains two or more kinds of different structures. May be. Alternatively, other polymers may be contained in addition to the specific polymer A of the present invention. Other polymer types include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivative, poly (styrene-phenylmaleimide) derivative, poly (meta- ) Acrylate and the like.
Among them, polyamic acid is preferred. Examples of the polyamic acid as another polymer include a polyamic acid having a structural unit in which both R ³ and R ⁴ are hydrogen atoms in the formula [3-2]. In particular, when a polyamic acid having a nitrogen-containing aromatic heterocycle or a nitrogen atom bonded to an aromatic group in W ^{2 of the} formula [3-2] is mixed with the liquid crystal aligning agent of the present invention, the liquid crystal aligning agent of the present invention is used. This is preferable from the viewpoint of improving the relaxation rate of the accumulated charge of the liquid crystal display element manufactured by the above method.

When the liquid crystal aligning agent of the present invention contains another polymer, the ratio of the polymer of the present invention to all the polymer components is preferably 5% by mass or more, for example, 5 to 95% by mass. Can be The proportion of the polymer of the present invention can be appropriately selected according to the properties of the liquid crystal alignment agent and the liquid crystal alignment film.

液晶 The liquid crystal alignment agent of the present invention is used for producing a liquid crystal alignment film, and generally takes the form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the polymer component described above and an organic solvent that dissolves the polymer component. At that time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed by setting the thickness of the coating film to be formed. The amount is preferably 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film, and is preferably 10% by mass or less from the viewpoint of storage stability of the solution. A particularly preferred concentration of the polymer is 2 to 8% by mass.

有機 The organic solvent contained in the liquid crystal aligning agent of the present invention is not particularly limited as long as the organic solvent dissolves the polymer. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolide Examples thereof include nonone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and the like. Among them, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and γ-butyrolactone. The organic solvents exemplified here may be used alone or as a mixture. Furthermore, even if the solvent does not dissolve the polymer, it may be mixed with an organic solvent and used as long as the produced polymer does not precipitate.

In addition, the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the applicability and the surface smoothness of the coating film when applying the liquid crystal aligning agent in addition to the above-described solvents. In general, such a mixed solvent is suitably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent used in combination are shown below, but are not limited thereto.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol , 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2- Ethane All, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol , 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, , 2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2- Tanthanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate , Ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, Diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl Ether ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Butyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol Ethylene glycol monomethyl ether Triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethoxypropion Methyl ethyl ester, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate And solvents such as n-butyl lactic acid ester and isoamyl lactic acid ester.

In addition to the above-mentioned solvents, for example, solvents represented by the following formulas [S-1] to [S-3] can be used.

In the formulas [S-1] and [S-2], R ²⁸ and R ²⁹ each represent an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. In the formula [S-3], R ³⁰ represents an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

Among the organic solvents used in combination, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene It is preferable to use glycol monobutyl ether or dipropylene glycol dimethyl ether. The type and content of such a solvent are appropriately selected according to the application device, application conditions, application environment, and the like of the liquid crystal aligning agent.

It is preferable that these solvents account for 20% by mass to 99% by mass of the total solvent contained in the liquid crystal aligning agent. Among them, 20% by mass to 90% by mass is preferable. More preferably, it is 20% to 70% by mass.

液晶 The liquid crystal aligning agent of the present invention may additionally contain components other than the polymer component and the organic solvent. Such additional components include an adhesion aid for improving the adhesion between the liquid crystal alignment film and the substrate and the adhesion between the liquid crystal alignment film and the sealant, a crosslinking agent for increasing the strength of the liquid crystal alignment film, and a liquid crystal alignment. Examples include a dielectric and a conductive substance for adjusting the dielectric constant and electric resistance of the film. Specific examples of these additional components are variously disclosed in publicly known documents relating to liquid crystal aligning agents. If one example is shown, paragraphs [0105] to [0116] of WO 2015/060357 are described. And the like.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. As an example of a method for obtaining a liquid crystal alignment film from a liquid crystal alignment agent, a liquid crystal alignment agent in the form of a coating liquid is applied to a substrate, dried, and baked. And a method of performing an orientation treatment.

The substrate on which the liquid crystal alignment agent of the present invention is applied is not particularly limited as long as it is a substrate having high transparency. Along with a glass substrate and a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. At that time, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is formed in terms of simplification of the process. In a reflection type liquid crystal display device, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light such as aluminum can be used for the electrode.

(4) The method of applying the liquid crystal aligning agent is not particularly limited, but industrially, screen printing, offset printing, flexographic printing, an inkjet method, and the like are generally used. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, a spray method and the like, and these may be used according to the purpose.

The baking after applying the liquid crystal aligning agent on the substrate is performed at 50 to 300 ° C., preferably 80 to 250 ° C. by a heating means such as a hot plate, a hot air circulating furnace, or an infrared furnace. (Liquid crystal alignment film) can be formed. If the thickness of the coating film formed after baking is too large, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be reduced. Preferably it is 10 nm to 100 nm. In the case where the liquid crystal is horizontally or obliquely aligned, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.

(4) After the liquid crystal aligning agent is applied on the substrate, the solvent is evaporated and baked by a heating means such as a hot plate, a thermal circulation oven, or an IR (infrared) oven. In the drying and baking steps after the application of the liquid crystal aligning agent, any temperature and time can be selected. Usually, in order to sufficiently remove the contained solvent, the conditions include firing at 50 ° C. to 120 ° C. for 1 minute to 10 minutes, and then firing at 150 ° C. to 300 ° C. for 5 minutes to 120 minutes.

The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film of a liquid crystal display device of a lateral electric field type such as an IPS type or an FFS type, and is particularly useful as a liquid crystal alignment film of an FFS type liquid crystal display device.

<Liquid crystal display device>
The liquid crystal display element of the present invention includes the above-described liquid crystal alignment film.After obtaining a substrate with a liquid crystal alignment film obtained from the above liquid crystal alignment agent, a liquid crystal cell is manufactured by a known method. This is an element using a liquid crystal cell. For example, two substrates disposed so as to face each other, a liquid crystal layer provided between the substrates, and a liquid crystal provided between the substrate and the liquid crystal layer and formed by the liquid crystal alignment agent of the present invention. This is a liquid crystal display device including a liquid crystal cell having an alignment film.

The substrate used for the liquid crystal display device of the present invention is not particularly limited as long as it is a substrate having high transparency, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, a substrate similar to the substrate described for the liquid crystal alignment film described above can be used.

The liquid crystal alignment film is formed by applying the liquid crystal alignment agent of the present invention on the substrate and then baking the liquid crystal, and is as described above in detail.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display device of the present invention is not particularly limited, and includes a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferable, and any of a positive liquid crystal material and a negative liquid crystal material is used. May be used. Specifically, for example, MLC-2003, MLC-6608, MLC-6609, MLC-3019, MLC-2041, MLC-7026-100, etc. manufactured by Merck can be used.

Specifically, a transparent glass substrate is prepared, and a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned so that a desired image can be displayed. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrodes. The insulating film can be, for example, a film made of SiO ₂ —TiO ₂ formed by a sol-gel method. Next, a liquid crystal alignment film is formed on each substrate under the above conditions.

Next, for example, an ultraviolet-curable sealant was disposed at a predetermined position on one of the two substrates on which the liquid crystal alignment film was formed, and liquid crystal was disposed at predetermined predetermined positions on the liquid crystal alignment film surface. Then, the other substrate is bonded and pressed so that the liquid crystal alignment film faces the liquid crystal to spread the liquid crystal on the front surface of the liquid crystal alignment film, and then the entire surface of the substrate is irradiated with ultraviolet rays to cure the sealant. Get the cell.

Alternatively, as a step after forming the liquid crystal alignment film on the substrate, when disposing a sealant at a predetermined place on one of the substrates, an opening capable of filling the liquid crystal from the outside is provided, and the liquid crystal is formed. After bonding the substrates without disposing them, a liquid crystal material is injected into the liquid crystal cell through an opening provided in the sealant, and then the opening is sealed with an adhesive to obtain a liquid crystal cell. The liquid crystal material may be injected by a vacuum injection method or a method utilizing capillary action in the air.

In any of the above methods, in order to secure a space for filling the liquid crystal material in the liquid crystal cell, a columnar projection is provided on one substrate, a spacer is sprayed on one substrate, or a sealing agent is used. It is preferable to take measures such as mixing a spacer into the mixture or combining them.

Next, install the polarizing plate. Specifically, it is preferable that a pair of polarizing plates be attached to surfaces of the two substrates opposite to the liquid crystal layer.

Note that the liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above description as long as the liquid crystal alignment agent of the present invention is used, and may be formed by other known methods. Good. The steps up to obtaining a liquid crystal display element from a liquid crystal aligning agent are disclosed in, for example, paragraphs [0074] to [0081] of Japanese Patent Application Laid-Open No. 2015-135393 and many other documents.

液晶 As described above, the liquid crystal display device manufactured using the liquid crystal alignment agent of the present invention has excellent reliability and can be suitably used for a large-screen, high-definition liquid crystal television and the like.

(4) The present invention will be described more specifically with reference to the following examples. However, the present invention is not construed as being limited to these examples.

The chemical structural formulas of the general-purpose solvent used for dissolving each material used in the examples and the monomer used as the raw material of each material used in the examples are as shown below.
NMP: N-methyl-2-pyrrolidone GBL: gamma-butyrolactone BCS: butyl cellosolve DC-1: 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride DC-2: bicyclo [3,3 , 0] Octane-2,4,6,8-tetracarboxylic dianhydride DC-3: 1,2,3,4-cyclobutanetetracarboxylic dianhydride DC-4: pyromellitic anhydride DC-5: Tetrahydro-1H-5,9-methanopyrano [3,4-d] oxepin-1,3,6,8 (4H) -tetranone DA-1: dimethyl 2,4-bis ((4-aminobenzamido) cyclobutane-1, 3-Dicarboxylate DA-2: dimethyl 2,4-bis ((4-aminophenyl) carbamoyl) cyclobutane-1,3-dicarboxylate DA-3: 1,2-bi (4-aminophenoxy) ethane DA-4: 1,2-bis (4-aminophenoxy) hexane DA-5: 1-tert-butoxycarbonyl-1,3-bis (4-aminophenethyl) urea DA-6: dimethyl 2,4-bis ((4-aminophenyl) ureido) cyclobutane-1,3-dicarboxylate

合成 The method of synthesizing each material and the method of measuring each property used in the examples are as shown below.

[viscosity]
In the synthesis example, the viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) using a sample volume of 1.1 mL, a cone rotor TE-1 (1 ° 34 ′, R24), and a temperature of 25. Measured in ° C.

[Molecular weight]
The molecular weight was measured by a GPC (room temperature gel permeation chromatography) apparatus, and the number average molecular weight (Mn and weight average molecular weight (Mw)) were calculated as polyethylene glycol and polyethylene oxide conversion values.

GPC apparatus: manufactured by Shodex (GPC-101), column: manufactured by Shodex (series of KD803 and KD805), column temperature: 50 ° C., eluent: N, N-dimethylformamide (lithium bromide-water as an additive) 30 mmol / L of hydrate (LiBr.H ₂ O), 30 mmol / L of phosphoric acid / anhydrous crystals (o-phosphoric acid), 10 ml / L of tetrahydrofuran (THF), flow rate: 1.0 ml / min. Standard sample: TSK standard polyethylene oxide (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol manufactured by Polymer Laboratory (peak top molecular weight (Mp) ) About 12,000, 4,000, 1,000). For the measurement, in order to avoid overlapping peaks, a sample in which four types of 900,000, 100,000, 12,000, and 1,000 were mixed and three types of 150,000, 30,000, and 4,000 were used. Two samples of the mixed sample were measured separately.

[Measurement of imidation rate]
20 mg of the polyimide powder is placed in an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Science Co., Ltd.)), and deuterated dimethyl sulfoxide (DMSO-d6, a mixture of 0.05% TMS (tetramethylsilane)) (0.1%). 53 ml) and sonicated to dissolve completely. The solution was subjected to proton NMR measurement at 500 MHz using an NMR measuring device (JNW-ECA500) (manufactured by JEOL Datum). The imidation ratio is determined by using a proton derived from a structure that does not change before and after imidation as a reference proton, and a peak integrated value of this proton and a proton peak derived from an amide acid NH group appearing in the vicinity of 9.5 ppm to 11.0 ppm. It was determined by the following equation using the integrated value. However, the imidation ratio calculated by the following formula is a value excluding a proton peak derived from an NH group contained in a monomer that does not participate in the polymerization reaction.

Imidation ratio (%) = (1−α · x / y) × 100

In the above formula, x is the integrated value of the proton peak derived from the NH group of the amic acid, y is the integrated value of the peak of the reference proton, and α is one NH group proton of the amic acid in the case of polyamic acid (imidation ratio is 0%). Is the ratio of the number of reference protons to the number of reference protons.

[Fabrication of liquid crystal cell for FFS mode]
A liquid crystal cell having a configuration of a fringe field switching (FFS) mode liquid crystal display element is manufactured.

First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. As a first layer, an ITO electrode having a solid pattern is formed as a first layer on the substrate. On the counter electrode of the first layer, an SiN (silicon nitride) film formed by a CVD method is formed as a second layer. The thickness of the second-layer SiN film is 500 nm, and functions as an interlayer insulating film. On the second-layer SiN film, a comb-shaped pixel electrode formed by patterning an ITO film as a third layer is arranged, and two pixels of a first pixel and a second pixel are formed. ing. The size of each pixel is about 10 mm long and about 5 mm wide. At this time, the first layer counter electrode and the third layer pixel electrode are electrically insulated by the action of the second layer SiN film.

The pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of square-shaped electrode elements whose central portion is bent. The width in the lateral direction of each electrode element is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is configured by arranging a plurality of bent-shaped electrode elements at the center portion, the shape of each pixel is not rectangular but is similar to the electrode element at the center portion. Bends have a shape resembling a bold letter. Each pixel is vertically divided by a center bent portion, and has a first region above the bent portion and a second region below the bent portion.

すると Comparing the first region and the second region of each pixel, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, with reference to the polarization direction of linearly polarized ultraviolet (LPUV) light of the liquid crystal alignment film described later, the electrode element of the pixel electrode is formed to have an angle of + 80 ° (clockwise) in the first region of the pixel. In the second region of the pixel, the electrode element of the pixel electrode is formed so as to form an angle of -80 ° (counterclockwise). That is, in the first region and the second region of each pixel, the directions of the rotation operation (in-plane switching) of the liquid crystal induced by the application of the voltage between the pixel electrode and the counter electrode in the substrate plane are mutually different. It is configured to be in the opposite direction.

Next, the liquid crystal aligning agent was filtered through a 1.0 μm filter, and then spin-coated on the prepared substrate with electrodes and a glass substrate having a 4 μm high columnar spacer with an ITO film formed on the back surface. And applied. After drying on a hot plate at 80 ° C. for 2 minutes, and irradiating the coated film surface with a linearly polarized ultraviolet ray having a extinction ratio of 26: 1 or more at a wavelength of 254 nm through a polarizing plate, it is heated in a hot air circulation oven at 230 ° C. for 30 minutes. Baking was performed to form a coating film having a thickness of 100 nm. The above two substrates are made into a set, a sealant is printed on the substrate, and another substrate is bonded so that the liquid crystal alignment film surfaces face each other so that the alignment direction becomes 0 °. It was cured to produce an empty cell. Liquid crystal MLC-3019 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell.

[Afterimage evaluation]
The polarizer was arranged so that the angle between the two polarizers was 90 °, and this state was referred to as crossed Nicols. The above-mentioned liquid crystal cell for afterimage evaluation was arranged between these two polarizers, and the alignment state of the injected liquid crystal was observed. A specific evaluation method was determined by observing whether or not the injected liquid crystal was uniformly aligned in the liquid crystal cell. When the liquid crystal in the liquid crystal cell is not uniformly aligned, a bright line is observed, and a clear bright / dark field cannot be observed due to the angle between the two polarizers and the alignment direction of the liquid crystal. On the other hand, when the liquid crystal in the liquid crystal cell is uniformly aligned, no bright line is observed, and a clear bright / dark field can be observed depending on the angle between the two polarizers and the alignment direction of the liquid crystal. As the evaluation criteria, the above-mentioned bright line was not observed at all, and "good" if a clear bright / dark field could be observed, and "clear" was observed if a clear bright / dark field could be observed, but a slight bright line was observed. A sample in which a clear bright / dark field could not be observed and a clear bright line was observed was regarded as “poor”.

[Display defect evaluation]
A display defect evaluation of the liquid crystal cell manufactured as described above was performed. The evaluation was performed by heating the liquid crystal cell prepared above in a heating oven at 60 ° C. for 2 weeks or more, and then observing the liquid crystal cell with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation). Specifically, the liquid crystal cell was placed in crossed Nicols with respect to the polarizer, observed with a polarizing microscope with a lens magnification of 5 times, and the number of confirmed bright spots was counted. "Good" and more than "poor".

[Evaluation of liquid crystal orientation]
The orientation evaluation of the liquid crystal cell produced above was performed. As an evaluation method, the liquid crystal cell was placed in a state where the luminance became the smallest under the polarizing plate crossed Nicols, and the alignment state immediately after the preparation and after the realignment treatment (heating at 110 ° C. for 1 hour and returning to room temperature) was performed. A comparison was made. When the flow alignment or the domain was not observed immediately after the liquid crystal cell was prepared, 〇 when the flow alignment or the domain was lost in the realignment treatment, 処理, and when the alignment defect was observed even after the realignment, ×. And

"Example of monomer synthesis"
Synthesis Example 1 Synthesis of Dimethyl 2,4-bis (3- (4-aminophenyl) ureido) cyclobutane-1,3-dicarboxylate

<First step>
Synthesis of Dimethyl 2,4-bis (3- (4-nitrophenyl) ureido) cyclobutane-1,3-dicarboxylate (100.0 g: 384.23 mmol) was weighed, toluene (500.0 g) was added, and triethylamine (97.2 g: 960.58 mmol) and Diphenylphosphoryl Azide [DPPA] (232.6 g: 845.31 mmol) were added. After stirring at room temperature for 30 minutes in a nitrogen atmosphere, the temperature was raised to 60 ° C., and the reaction was further performed for 3 hours. It was confirmed that gas was generated as the reaction progressed, and the generation of gas stopped. The reaction solution was returned to room temperature, and 1,4diaza-bicyclo [2.2.2] octane [DABCO] (2.15 g: 19.21 mmol), 4-nitroaniline (116.76 g: 845.31 mmol), and tetrahydrofuran (200. 0 g) was added, the temperature was raised again to 60 ° C., and the mixture was reacted under a nitrogen atmosphere for 24 hours. After confirming the disappearance of the raw materials by TLC, the reaction solution was transferred to a separating funnel. At this time, since the organic layer was separated into two layers, the lower layer was separated, poured into methanol, and stirred to precipitate a solid. This solid was collected by filtration. One upper layer was washed three times with 100 ml of pure water, and the solvent was distilled off from the organic layer using a rotary evaporator. As a result, a solid was deposited. This material was collected, mixed with the solid obtained above, washed twice with methanol (300.0 g) under heating (reflux: 1 hour), and dried in vacuo to give a pale yellow solid (136. 56 g: 67% yield). The structure was confirmed by a nuclear magnetic resonance spectrum [ ¹ H-NMR (400 MHz)], and it was confirmed that it was a target. The measurement data is shown below.

¹ H-NMR (400 MHz: D6-DMSO) δ: 9.34 (s: 2H), 8.11 (q: 4H), 7.60 (q: 4H), 7.04 (d: 2H), 4 .78 (q: 2H), 4.07 (m: 2H), 3.60 (s: 6H)

<Second step>
Synthesis of Dimethyl 2,4-bis (3- (4-aminophenyl) ureido) cyclobutane-1,3-dicarboxylate Dimethyl 2,4-bis (3- (4 -Nitro-phenyl) ureido) -cyclobutane-1,3-dicarboxylate (100.0 g: 188.52 mmol), 10% palladium carbon (10.0 g), fully degassed N, N-dimethylformamide (500.0 g) ) Was added, the hydrogen gas was replaced, and the reaction was carried out at 60 ° C. for 24 hours with strong stirring. After confirming the disappearance of the raw materials, palladium carbon was removed by filtration in a hot state, activated carbon (30 g) was further added, the mixture was stirred at 60 ° C. for 3 hours, and filtered while hot. The filtrate was poured into 1 L of methanol and stirred at 10 ° C. for a while, and a solid was deposited. The obtained solid was collected by filtration, washed twice with 300.0 g of methanol, and dried under vacuum to obtain 74.5 g of the target milky white solid. The structure was confirmed by a nuclear magnetic resonance spectrum [ ¹ H-NMR (400 MHz)], and it was confirmed that it was a target. The measurement data is shown below.

¹ H-NMR (400 MHz: D6-DMSO) δ: 8.01 (s: 4H), 6.95 (q: 4H), 6.49 (d: 2H), 6.45 (q: 4H), 4 .75 (q: 2H), 4.73 (br: 4H), 3.64 (s: 6H), 3.35 (m: 2H)

Synthesis Example 2
Synthesis of Dimethyl 2,4-bis (4-aminobenzamido) cyclobutane-1,3-dicarboxylate

<First step>
Synthesis of Dimethyl 2,4-bis ((tert-butoxycarbonyl) amino) cyclobutane-1,3-dicarboxylate Bis (methoxycarbonylcyclobutadicarboxycarbonyl-cyclobutadicarbonate-cyclobutadicarbonate-1) : 418 mmol), toluene (1000 g) was added, triethylamine (92.0 g: 916 mmol) and Diphenylphosphoryl Azide [DPPA] (252 g: 916 mmol) were added, and the mixture was stirred at room temperature under a nitrogen atmosphere for 30 minutes, and then heated to 60 ° C. The temperature was raised and the reaction was continued for another 3 hours. It was confirmed that gas was generated as the reaction progressed, and the generation of gas stopped. The reaction solution was cooled to room temperature, and 1,4diaza-bicyclo [2.2.2] octane [DABCO] (2.35: 20.9 mmol) and tert-butyl alcohol (155 g: 2.09 × 10 ³ mmol) were added. In addition, the temperature was raised to 80 ° C., and the mixture was heated and stirred under a nitrogen atmosphere for 24 hours. After the completion of the reaction, the reaction solution was cooled at −20 ° C., and the product was recrystallized. The solid was recrystallized using ethyl acetate as a good solvent and hexane as a poor solvent, and dried under vacuum to obtain a target white solid (60.0 g: 145 mmol, yield: 35%). The structure of the product was confirmed by nuclear magnetic resonance spectrum [ ¹ H-NMR (400 MHz)] to confirm that it was the desired product. The measurement data is shown below.

¹ H-NMR (400 MHz: D6-DMSO) δ: 7.40 to 7.38 (ss: 2H), 4.51 to 4.49 (q: 2H), 3.56 (s: 6H), 3. 42-3.38 (q: 2H), 1.36 (s: 18H)

<Second step>
Synthesis of Dimethyl 2,4-bis (4-nitrobenzamido) cyclobutane-1,3-dicarboxylate Dimethyl 2,4-bis ((tert-butoxycarbyl) obtained by the above operation in a 2 L 4-necked flask equipped with a nitrogen inlet tube. Amino) Cyclobutane-1,3-dicarboxylate (60.0 g: 145 mmol) was weighed out, chloroform (60.0 g) was added, and trifluoroacetic acid [TFA] (164 g: 1.45 × 10 ³ mmol) was added in an ice bath. Was added and the mixture was heated and stirred at 40 ° C. for 12 hours. The reaction solution was cooled to about 0 ° C., triethylamine (32.1 g: 318 mmol) was added, and the mixture was stirred at room temperature for 0.5 hour. Thereafter, 4-nitrobenzoic acid chloride (67.0 g: 602 mmol) dissolved in 670 g of chloroform was gently added dropwise, and the mixture was stirred at room temperature for 6 hours. After completion of the reaction, the reaction solution was concentrated, washed three times with 200 ml of pure water, and washed once with 200 ml of saturated saline. Thereafter, the solid was recrystallized using chloroform as a good solvent and hexane as a poor solvent, and the obtained solid was dried under vacuum to obtain 56.0 g (112 mmol) of a target pale yellow solid. The structure of the product was confirmed by nuclear magnetic resonance spectrum [ ¹ H-NMR (400 MHz)] to confirm that it was the desired product. The measurement data is shown below.

¹ H-NMR (400 MHz: D6-DMSO) δ: 9.29-9.27 (d: 2H), 8.37 (dd: 4H), 8.06 (dd: 4H), 5. 23-5.17 (m: 2H), 3.86-3.82 (m: 2H), 3.55 (s: 6H)

<Third step>
Synthesis of Dimethyl 2,4-bis (4-aminobenzamido) cyclobutane-1,3-dicarboxylate (20.0 g: 112 mmol), 10% palladium-supported activated carbon (11.2 g), and sufficiently degassed N, N-dimethylformamide (500 g) were added, and the system was filled with hydrogen gas and replaced. The mixture was vigorously stirred at room temperature for 48 hours. After completion of the reaction, palladium carbon was removed, and N, N-dimethylformamide was concentrated under reduced pressure. The precipitated solid was dissolved in a minimum amount of DMF and recrystallized using hexane as a poor solvent. The obtained solid was dispersed in methanol and heated and stirred at 80 ° C. for 6 hours. Then, the solid was recovered by filtration and dried under reduced pressure to obtain the target white solid (35.0 g: 79.5 mmol, yield: 71%). The structure was confirmed by a nuclear magnetic resonance spectrum [ ¹ H-NMR (400 MHz)], and it was confirmed that it was a target. The measurement data is shown below.

¹ H-NMR (400 MHz: D6-DMSO) δ: 8.36 to 8.34 (dd: 2H), 7.56 to 7.53 (q: 4H), 6.55 to 6.52 (q : 4H), 5.65 (br: 4H), 5.14-5.08 (q: 2H), 3.76-3.72 (q: 2H), 3.49 (s: 6H).

[Synthesis Example 1]
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 5.06 g (11.5 mmol) of DA-1 was added, 20.3 g of NMP was added, and the mixture was heated and stirred at 70 ° C. for 30 minutes while sending nitrogen. Dissolved. After the diamine solution was cooled to room temperature by water cooling, 2.37 g (11.3 mmol) of DC-1 was added with stirring, 9.50 g of NMP was further added, and the mixture was heated and stirred at 40 ° C. for 24 hours to form a polyamic acid. A solution (PAA-1) was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 300 mPa · s. The molecular weight and molecular weight distribution of this polyamic acid were Mn = 1.27 × 10 ⁴ , Mw = 3.07 × 10 ⁴ , and Mw / Mn = 2.41.

[Synthesis Examples 2, 3, 4, 5, 6]
Using a diamine component, a tetracarboxylic acid component, and NMP shown in Table 1 below, the reaction temperature, the solid content concentration, and the same procedure as in Synthesis Example 1 were carried out to obtain a polyamic acid solution PAA- shown in Table 1 below. 2, PAA-3, PAA-4, PAA-5, PAA-6 were obtained. The viscosity and molecular weight of the obtained polyamic acid are shown in Table 2 below.

[Synthesis Example 7]
In a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 55.0 g of the obtained polyamic acid solution (PAA-1) was taken, 18.3 g of NMP was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained polyamic acid solution, 5.12 g (50.7 mmol) of acetic anhydride and 1.59 g (20.1 mmol) of pyridine were added, and the mixture was heated and stirred at 55 ° C. for 6 hours to perform chemical imidization. The obtained reaction solution was poured into 218 ml of methanol with stirring, and the deposited precipitate was collected, followed by washing with 218 ml of methanol three times. The obtained resin powder was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (PIP-1). The imidation ratio of this polyimide resin powder was 95% or more.

[Synthesis Example 8]
Using a polyamic acid solution (PAA-2), chemical imidization was carried out in the same procedure as in Synthesis Example 7 with the amounts of acetic anhydride and pyridine introduced, respectively, and the reaction temperature. However, during heating and stirring, a gel-like solid was deposited, and chemical imidization could not be performed accurately.

[Synthesis Example 9]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 24.0 g of the obtained polyamic acid solution (PAA-3) was added, 8.00 g of NMP was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained polyamic acid solution, 2.56 g (25.0 mmol) of acetic anhydride and 1.19 g (15.1 mmol) of pyridine were added, and the mixture was heated and stirred at 55 ° C. for 4 hours to perform chemical imidization. The obtained reaction solution was poured into 107 ml of methanol with stirring, and the deposited precipitate was collected and subsequently washed three times with 107 ml of methanol. The obtained resin powder was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (PIP-3). The imidation ratio of this polyimide resin powder was 95% or more.

[Synthesis Example 10]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 18.0 g of the obtained polyamic acid solution (PAA-3) was added, 6.00 g of NMP was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained polyamic acid solution, 0.77 g (7.53 mmol) of acetic anhydride and 0.30 g (3.80 mmol) of pyridine were added, and the mixture was heated and stirred at 55 ° C. for 2 hours to perform chemical imidization. The obtained reaction solution was poured into 75.2 ml of methanol with stirring, and the deposited precipitate was collected. Subsequently, the precipitate was washed three times with 75.2 ml of methanol. The obtained resin powder was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (PIP-4). The imidation ratio of this polyimide resin powder was 73%.

[Synthesis Example 11]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 44.0 g of the obtained polyamic acid solution (PAA-4) was added, 14.7 g of NMP was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained polyamic acid solution, 4.50 g (44.1 mmol) of acetic anhydride and 2.09 g (26.5 mmol) of pyridine were added, and the mixture was heated and stirred at 55 ° C. for 2 hours to perform chemical imidization. The obtained reaction solution was poured into 196 ml of methanol with stirring, and the deposited precipitate was collected, followed by washing with 196 ml of methanol three times. The obtained resin powder was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (PIP-5). The imidation ratio of this polyimide resin powder was 95% or more.

[Synthesis Example 12]
96.5 g of the obtained polyamic acid solution (PAA-5) was placed in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 32.2 g of NMP was added, and the mixture was stirred at room temperature for 30 minutes. To the obtained polyamic acid solution, 7.03 g (68.9 mmol) of acetic anhydride and 3.64 g (46.0 mmol) of pyridine were added, and the mixture was heated and stirred at 55 ° C. for 2 hours to perform chemical imidization. The obtained reaction solution was poured into 433 ml of methanol with stirring, and the deposited precipitate was recovered, followed by washing with 433 ml of methanol three times. The obtained resin powder was dried at 60 ° C. for 12 hours to obtain a polyimide resin powder (PIP-6). The imidation ratio of this polyimide resin powder was 62%.

[Synthesis Example 13]
Using a polyamic acid solution (PAA-6), the amounts of acetic anhydride and pyridine to be introduced, respectively, and the reaction temperature, chemical imidization was carried out in the same procedure as in Synthesis Example 12 to obtain a polyimide resin powder (PIP-7). Obtained. The imidation ratio of this polyimide resin powder was 68%.

イミド The imidation ratio of the polyimide resin powders obtained in Synthesis Examples 7, 8, 9, 10, 11, 12, and 13 is shown in Table 3 below.

[Synthesis Example 14]
5.56 g of the polyimide resin powder (PIP-1) was placed in a 50 ml eggplant flask, 40.7 g of NMP was added so that the solid content concentration became 12%, the mixture was stirred at 70 ° C. for 24 hours, dissolved, and dissolved in a polyimide solution (PIS-1). -1) was obtained. No abnormality such as turbidity or precipitation was observed in this liquid crystal aligning agent, and it was confirmed that the solution was a uniform solution. The molecular weight and molecular weight distribution of this polyimide solution were Mn = 1.30 × 10 ⁴ , Mw = 3.35 × 10 ⁴ , and Mw / Mn = 2.56.

[Synthesis Example 15]
A polyimide solution (PIS-2) was obtained in the same manner as in Synthesis Example 14 using the polyimide resin solid (PIP-2). However, unnecessary substances were generated, and a uniform polyimide solution could not be obtained.

[Synthesis examples 16, 17, 18, 19, 20]
Using a polyimide resin powder (PIP-3, PIP-4, PIP-5, PIP-6, PIP-7) and a polyimide solution (PIS-3, PIS-4, PIS-5, PIS-6, PIS-7) were obtained. The molecular weight of the obtained polyimide solution is shown in Table 4 below.

When a polyamic acid solution obtained by successively polymerizing DA-1 or DA-2 and DC-1 was chemically imidized, the polyamic acid composed of DA-1 could be normally chemically closed, whereas the DA-2 A gel-like solid material precipitated during the chemical ring closure of the polyamic acid consisting of and could not be evaluated.

ＤＡ By using the DA-1 analog included in the present invention, the solubility in a solvent is specifically improved when a polyamic acid and a polyimide obtained by chemically closing the polyamic acid are used, as compared with the DA-2 analog. Further, the materials included in the present invention, PIS-1, PIS-3, PIS-4, and PIS-5, exhibit practically usable characteristics as a liquid crystal alignment film, and further reduce the risk of display defects. It is shown below because it is possible.

[Synthesis Example 21]
6.50 g of the polyimide solution (PIS-1) obtained in Synthesis Example 1 was placed in a 20 ml sample tube containing a stirrer, 1.00 g of NMP, 3.53 g of the GBL solution, and 3.00 g of BCS were added. The mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-1). Using this liquid crystal aligning agent (A-1), a liquid crystal cell for liquid crystal alignment evaluation and luminescent spot evaluation was produced in the following procedure.

[Synthesis Example 22]
Using a polyimide solution (PIS-3, PIS-4, PIS-5, PIS-6, PIS-7), the liquid crystal aligning agents (A-2, A-3, A-4, A-5, A-6 and A-7) were obtained.

Using this liquid crystal aligning agent (A-2, A-3, A-4, A-5, A-6, A-7), a liquid crystal cell for liquid crystal alignment evaluation and luminescent spot evaluation according to the following procedure. Was prepared.

[Example 1]
After the liquid crystal aligning agent (A-1) obtained in Synthesis Example 21 was filtered through a 1.0 μm filter, the liquid crystal aligning agent was spin-coated on a 30 mm × 40 mm ITO substrate, and was then placed on a hot plate at 80 ° C. After drying for 2 minutes, the coated surface is irradiated with a linearly polarized ultraviolet ray having a wavelength of 254 nm having an extinction ratio of 26: 1 through a polarizing plate at various exposure amounts between 0.15 J / cm ² and 0.40 J / cm ^2. After that, baking was performed in a hot air circulating oven at 230 ° C. for 17 minutes to obtain a substrate with a liquid crystal alignment film. A pair of the obtained two substrates was used as a set, a sealant was printed on the substrates, and another substrate was bonded so that the liquid crystal alignment films faced each other so that the alignment direction was 0 °. The agent was cured to produce an empty cell. Liquid crystal MLC-3019 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal alignment liquid crystal cell. Table 5 below shows the evaluation results of the afterimages. The liquid crystal alignment was evaluated based on the evaluation criteria described above.

[Examples 2, 3, 4]
Instead of the liquid crystal aligning agent (A-1), each liquid crystal aligning agent (A-2, A-3, A-4) was used, and the irradiation amount of ultraviolet rays and the sintering temperature were the same as in Example 1. A liquid crystal cell for afterimage evaluation was prepared by the method. Table 5 below shows the evaluation results of the afterimages.

[Comparative Examples 1 and 2]
Each of the liquid crystal aligning agents (A-5, A-6) was used in place of the liquid crystal aligning agent (A-1), and the amount of ultraviolet irradiation and the sintering temperature were evaluated in the same manner as in Example 1. A liquid crystal cell was prepared. Table 5 below shows the evaluation results of the afterimages.

The liquid crystal aligning agents (A-1, A-2, A-3, A-4) comprising DA-1 and DC-1 according to the present invention have an exposure amount of 0.1 J / cm ² to 0.40 J /. It exhibits very good afterimage properties between cm ² . Also, copolymerized polyimides using DA-1 and other kinds of diamine components and DC-1 show good afterimage characteristics, and the combination of diamine components gives good and poor image retention characteristics and changes in exposure. As an example, in a liquid crystal aligning agent (A-2) obtained by copolymerizing DA-1 and DA-3, a wider exposure is performed when the exposure amount is between 0.1 J / cm ² and 0.40 J / cm ^2. A better afterimage characteristic is exhibited in the amount range. Further, a liquid crystal aligning agent (A-3) produced using a polyimide solution (PIS-3) in which the imidation ratio was controlled in the step of chemically imidizing a polyamide comprising DA-1 and DA-3 was 0.10 J / Cm ² , which exhibits good afterimage characteristics, and is a material capable of obtaining good afterimage characteristics at a very low exposure dose. Further, the liquid crystal aligning agent (A-4) composed of DA-1 and DA-4 can also obtain very good afterimage characteristics at a very low exposure dose, similarly to the liquid crystal aligning agent (A-3) described above. It is possible.

On the other hand, the liquid crystal aligning agent (A-5) composed of DA-3 and DA-5 and DC-1 and DC-2 shown in Comparative Example 1 shows good afterimage characteristics, but is 0.20 J / cm ² or more. Is required. From the viewpoint of the required exposure dose, the liquid crystal aligning agents (A-2, A-3, A-4) have a required exposure dose of about 0.1 J / cm ² when exhibiting good afterimage characteristics. The superiority of DA-1 contained in the term is suggested. Further, since the required exposure amount can be adjusted by a combination of the polymer units, it is possible to realize a tact time desired by the user in consideration of an actual manufacturing site.

The liquid crystal aligning agent (A-6) obtained from DA-3, DA-5 and DC-1 is similar to the above liquid crystal aligning agents (A-1, A-2, A-3, A-4). Although having a mother skeleton, good afterimage characteristics cannot be obtained, suggesting the superiority of using DA-1 included in the present invention.

[Example 5]
After the liquid crystal cell for afterimage evaluation prepared using the liquid crystal aligning agent (A-1) in Example 1 was heated in a heating oven at 60 ° C. for 2 weeks or more, it was observed with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation). I went by. As described above, according to the number of bright spots confirmed by observation with a polarizing microscope, the criteria were "good" if the number of bright spots was less than 5, and "poor" if more than five. Table 6 shows the evaluation results of the luminescent spots of the liquid crystal cell after the long-term AC driving in each case.

[Examples 6, 7, 8]
Instead of the liquid crystal aligning agent (A-1), each of the liquid crystal aligning agents (A-2, A-3, A-4) was used. A liquid crystal cell for display defect evaluation was produced by the method. Table 6 below shows the results of the display failure evaluation in each case.

[Comparative Examples 3 and 4]
Each of the liquid crystal aligning agents (A-5, A-6) was used in place of the liquid crystal aligning agent (A-1). A liquid crystal cell for evaluation was produced. Table 6 below shows the results of the display failure evaluation in each case.

液晶 The liquid crystal aligning agents (A-1, A-2, A-3, A-4) comprising DA-1 and DC-1 according to the present invention show very good results in poor evaluation. On the other hand, soluble polyimide obtained by copolymerizing DA-3, DA-5, DC-1, and DC-2 shown in Comparative Example 1 and copolymerizing DA-3, DA-5, and DC-1 The liquid crystal aligning agent composed of the soluble polyimide obtained in (1) was defective. The liquid crystal aligning agent comprising a soluble polyimide using DA-1 contained in the present invention is also effective in suppressing display defects.

[Synthesis Example 23]
Polymerization of DC-3 / DA-6 polyamic acid In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 4.00 g (8.50 mmol) of DA-6, 40.58 g of NMP were added, and nitrogen was added. The mixture was stirred at room temperature for 10 minutes while being fed to dissolve. While stirring, 1.54 g (7.64 mmol) of DC-3 was added to the diamine solution, and the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution (PAA-8) having a concentration of 12% by mass. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 420 mPa · s. The molecular weight and molecular weight distribution of this polyamic acid were Mn = 9.82 × 10 ³ , Mw = 2.16 × 10 ⁴ , and Mw / Mn = 2.20.

[Synthesis Examples 24, 25, 26, 27, 28, 29]
Using a diamine component, a tetracarboxylic acid component, and NMP shown in Table 7 below, the reaction temperature, solid content concentration, and the same procedure as in Synthesis Example 1 were carried out to obtain a polyamic acid solution PAA- shown in Table 7 below. 9, PAA-10, PAA-11, PAA-12, PAA-13 and PAA-14 were obtained. The viscosity and molecular weight of the obtained polyamic acid are shown in Table 8 below.

[Synthesis Example 30]
Polyamic acid solution (PAA-8, PAA-9, PAA-10, PAA-11, PAA-12, PAA-13, PAA-14) obtained in a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube. And 30.0 g of NMP were added thereto, followed by stirring at room temperature for 30 minutes. Acetic anhydride was added to the obtained polyamic acid solution in an amount of 5 mol times the amount of the carboxylic acid of the polyamic acid and pyridine in an amount of 5 mol times, and the mixture was heated and stirred at 70 ° C. for 3 hours to perform chemical imidization. The obtained reaction solution was poured into 500 ml of methanol with stirring, and the deposited precipitate was recovered, followed by washing three times with 300 ml of methanol. The obtained resin powder was dried at 80 ° C. for 12 hours to obtain a polyimide resin powder (PIP-8, PIP-9, PIP-10, PIP-11, PIP-12, PIP-13). PIP-14 could not be obtained as a polyimide because it gelled during chemical imidization. Table 9 below shows the molecular weight and the imidation ratio of this polyimide resin powder.

[Examples 7 to 12]
In a 50 ml eggplant flask, weigh 10.0 g of the polyamic acid solution (PAA-8 to PAA-14) obtained above, add 4.00 g of NMP and 6.0 g of BCS, and stir at room temperature for 24 hours. Alignment agents (A-8 to A-14) were obtained. A-14 was used as a comparative object.

[Examples 13 to 18]
2.0 g of the polyimide resin powder (PIP-8 to PIP-13) obtained above was weighed and placed in a 50 ml eggplant flask, 18.0 g of NMP was added, and the mixture was stirred at room temperature for 24 hours. .67 g was added and stirred for 1 hour to obtain liquid crystal aligning agents (A-15 to A-20).

[Test Example 1]
With respect to the alignment agents A-8 to A-20 obtained in Examples 7 to 18, the liquid crystal alignment films were evaluated based on the following method. A-14 (Comparative Example 3) and SE-6414 (Comparative Example 4) manufactured by Nissan Chemical Industries, Ltd. were used as comparison targets.

<Evaluation of liquid crystal alignment, voltage holding ratio, and pretilt angle>
The liquid crystal alignment, voltage holding ratio, and pretilt angle were evaluated as follows.

[Preparation of liquid crystal cell for observation of liquid crystal alignment and measurement of voltage holding ratio and pretilt angle]
After the liquid crystal aligning agent is filtered with a filter of 1.0 μm, a substrate with electrodes (a glass substrate having a size of 30 mm in width × 40 mm in length and 0.7 mm in thickness. The electrode is a rectangle of 10 mm in width × 40 mm in length, (ITO electrode having a thickness of 35 nm) by spin coating. After drying on a hot plate at 80 ° C. for 1 minute, a substrate fired at 120 ° C. for 20 minutes using an IR oven and a substrate fired at 230 ° C. were prepared. The film thickness was set to 100 nm after firing. This liquid crystal alignment film was rubbed with a rayon cloth (YA-20R manufactured by Yoshikawa Kako) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.4 mm), and then into pure water. The substrate was cleaned by irradiating ultrasonic waves for 1 minute to remove water droplets by air blow, and then dried at 80 ° C. for 15 minutes to obtain a substrate with a liquid crystal alignment film.

After preparing two substrates with the above liquid crystal alignment film, spraying a 4 μm spacer on one of the liquid crystal alignment film surfaces, printing a sealant thereon, and rubbing the other substrate in the opposite direction. After laminating so that the directions and the film surfaces face each other, the sealing agent was cured to produce an empty cell. MLC-3019 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. Then, after observing the orientation of the liquid crystal, the liquid crystal cell was heated at 110 ° C. for 1 hour and left at 23 ° C. overnight to obtain a liquid crystal cell for voltage holding ratio measurement.

Using the liquid crystal cell for voltage holding ratio measurement obtained by the above procedure, applying a voltage of 1 V for 60 μs at a temperature of 60 ° C. and measuring the voltage after 166.7 ms, and how much the voltage can be held Was calculated as the voltage holding ratio. The voltage holding ratio was measured using a VHR-1 voltage holding ratio measuring device manufactured by Toyo Corporation.

[Evaluation of pretilt angle]
For measurement of the pretilt angle, an Axo Scan Muller matrix polarimeter manufactured by Optometrics was used.

[Evaluation of rubbing resistance]
After filtering the liquid crystal aligning agent with a filter of 1.0 μm, a substrate with electrodes (a glass substrate of 30 mm in width × 40 mm in length and 1.1 mm in thickness. The electrode is a rectangle of 10 mm in width × 40 mm in length, (ITO electrode having a thickness of 35 nm) by spin coating. After drying on a hot plate at 80 ° C. for 1 minute, a substrate fired at 120 ° C. for 20 minutes using an IR oven and a substrate fired at 230 ° C. were prepared. The film thickness was set to 100 nm after firing. The liquid crystal alignment film was rubbed with a rayon cloth (YA-20R manufactured by Yoshikawa Kako) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.5 mm), and then a confocal laser microscope Was used to evaluate the rubbing resistance. When peeled, peeling, scraping and flaws were found to be bad, and when good, good.

[Evaluation of liquid crystal orientation]
The evaluation of liquid crystal alignment was performed based on the same evaluation criteria as in Example 1. It should be noted that “〇” in the evaluation criteria was “good”, and “×” in the evaluation criteria was “poor”.
Tables 10 to 13 show the results of the various evaluations described above.

When the film is formed by baking at 120 ° C., in particular, the polyamic acid cannot be imidized under this condition, so that the physical strength becomes very weak, the film is scraped by the rubbing treatment, and the orientation of the liquid crystal tends to deteriorate. However, the polyamic acid and the polyimide using the diamine of the present invention have extremely excellent rubbing resistance even at low-temperature baking, and have good liquid crystal alignment. Further, the pretilt angle is very small and the VHR is high.

Furthermore, the diamine of the present invention can have a very high solubility, and the unintroduced PAA-14 could not be chemically imidized. However, the imidation ratio of PIP-13 introduced with 50 mol% as the diamine component was not improved. Can be adjusted without a problem even if it is 95% or more, and good alignment film characteristics are obtained. In general, when very poorly soluble components such as DC-1 and DC-4 are incorporated, it is often difficult to chemically imidize them. The polyimide can be adjusted. By using a soluble polyimide, the reliability can be further improved.

In the case of baking at 230 ° C., the rubbing resistance, the liquid crystal alignment, and the reliability are improved because the imidization of the material of the comparative example also proceeds, but the alignment agent of the present invention shows good characteristics and the pretilt angle tends to be slightly improved. However, there is a very small merit compared to the comparison object. Further, the reliability is very high.

Therefore, by using the diamine of the present invention, a liquid crystal aligning agent corresponding to low-temperature firing to high-temperature firing can be produced, and an alignment film having a very low pretilt can be obtained.

[Test Example 2]
The liquid crystal aligning agents (A-16, A-17, A-20) obtained in Examples 14, 15 and 18 and the liquid crystal aligning agent A-5 of Comparative Example were filtered with a 1.0 μm filter. Thereafter, a liquid crystal aligning agent is spin-coated on a 30 mm × 40 mm ITO substrate, dried on a hot plate at 80 ° C. for 2 minutes, and a linearly polarized light having an extinction ratio of 26: 1 is applied to the coating surface via a polarizing plate. After irradiating with ultraviolet light of 254 nm in the range of 0.1 to 1.0 J / cm ² , the substrate was baked in a hot air circulating oven at 150 ° C. for 20 minutes to obtain a substrate with a liquid crystal alignment film. A pair of the obtained two substrates was used as a set, a sealant was printed on the substrates, and another substrate was bonded so that the liquid crystal alignment films faced each other so that the alignment direction was 0 °. The agent was cured to produce an empty cell. Liquid crystal MLC-3019 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal alignment liquid crystal cell. Table 14 shows the results of the liquid crystal alignment in each case. The evaluation was performed based on the same evaluation criteria as in Example 1.

可溶性 It was found that the soluble polyimide using the diamine and DC-1 according to the present invention showed orientation when preliminarily dried and then irradiated with UV and baked at 150 ° C. The material of Comparative Example 1 exhibits orientation at high temperatures, but does not exhibit orientation at low temperatures regardless of UV irradiation intensity. Therefore, it was found that the use of the diamine of the present invention enables photoalignment at a low temperature.

(4) Since the polyamic acid and polyimide obtained from the diamine of the present invention have excellent solubility in a solvent, it is possible to produce a liquid crystal alignment agent and a film which could not be realized from the viewpoint of solubility. Further, it can be widely applied from a rubbing alignment film to a photo alignment film. In particular, it will be possible to cope with low-temperature sintering, low pretilt angle materials, simplification of the optical alignment process, etc., which will be the trends of the horizontal electric field method in the future.

A liquid crystal display device having a liquid crystal alignment film manufactured from the material of the present invention has excellent afterimage characteristics and long-term display stability, and has a large-screen high-definition liquid crystal television, a small and medium-sized car navigation system, and a smartphone. It can be suitably used for such purposes. Furthermore, since it can be manufactured more easily in the manufacturing process, improvement in yield and production efficiency can be expected.

Claims

A liquid crystal aligning agent containing at least one polymer selected from a polyimide precursor containing a structural unit represented by the following formula [3-1] and a polyimide which is an imide compound thereof.

In the formula, V 0 is a tetravalent organic group derived from a tetracarboxylic acid derivative, W 1 is a divalent organic group represented by the following formula [2-1], and R 3 and R 4 are Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

In the formula, Y 1 is a tetravalent organic group having an alicyclic structure, X 1 and X 2 are divalent organic groups, and Z 1 and Z 2 are each independently a single bond, —NH— or —O—, R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms, and * represents a bonding site.
A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 1.
A liquid crystal display device comprising the liquid crystal alignment film according to claim 2.
A diamine represented by the following formula [1].

In Formula [1], Y 1 is a tetravalent organic group having an alicyclic structure, X 1 and X 2 are divalent organic groups, and Z 1 and Z 2 are each independently A single bond, —NH— or —O—, and R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms.
A polymer obtained from the diamine component containing the diamine according to claim 4.
5. A method for producing a diamine compound according to claim 4, wherein the compound of the following formula (11) is used as a starting material, and the compound of the following formula (12) or the compound of the following formula (13) is produced.

In the formulas (11) to (13), Y 1 is a divalent organic group having an alicyclic structure, and R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms. . In Formula (13), R 31 and R 32 represent a hydrogen atom or an amino-protecting group.