TWI791731B - Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element and manufacturing method thereof - Google Patents

Abstract

The present invention provides a liquid crystal alignment agent comprising: a polymer component; and a compound [A] selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2) at least one of the group. R ¹ is an alkyl group having 1 to 4 carbon atoms, -CO-CH ₃ , or -R ⁴ -OH. R ² is a hydrogen atom or an alkyl group with 1 to 4 carbons. n is 1 or 2. When n is 2, R ² is a hydrogen atom. R ³ is an alkanediyl group having 1 to 3 carbon atoms.

Description

Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element and its manufacture method [Cross-reference to related applications]

This application is based on Japanese Patent Application No. 2018-23423 filed on February 13, 2018, the contents of which are incorporated herein by reference.

The disclosure relates to a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal element and a manufacturing method thereof.

Liquid crystal elements are used in various applications including display devices such as televisions, personal computers, and smartphones. These liquid crystal elements include a liquid crystal alignment film having a function of aligning liquid crystal molecules in a certain direction. Usually, the liquid crystal alignment film is formed on the substrate by applying a liquid crystal alignment agent obtained by dissolving polymer components in an organic solvent on the substrate, preferably by heating. As a polymer component of a liquid crystal alignment agent, polyamic acid or soluble polyimide is widely used because it is excellent in mechanical strength, liquid crystal alignment, and affinity with liquid crystals. In addition, as the solvent component of the liquid crystal alignment agent, a solvent with high solubility to polymers such as polyamic acid or soluble polyimide (such as N-methyl-2-pyrrolidone or γ-butyrolactone) is usually used. and other good solvents), and solvents with high wetting and spreading properties on the substrate (such as butyl cellosolve, etc. poor solvent) mixed solvent (for example, refer to Patent Document 1, Patent Document 2).

[Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-198975

[Patent Document 2] Japanese Patent Laid-Open No. 2016-206645

As LCD TVs, in order to obtain the sense of presence brought by the further improvement of display quality in recent years, 4K (for example, 3840 pixels × 2160 pixels) or 8K (for example, 7680 pixels × 4320 pixels) have been produced to increase the picture quality. The specification of the prime number display device. As the number of pixels of the display device increases and the pixel size decreases, the pixel electrode becomes a finer structure, and the unevenness density per unit area of the formation surface of the pixel electrode becomes higher. In this case, when the liquid crystal alignment agent is applied to the formation surface of the pixel electrode to form an alignment film, the liquid crystal alignment agent is difficult to wet and spread to the fine concave-convex structure of the pixel electrode, and there is a concern that the coating property to the substrate cannot be sufficiently ensured. . In order to obtain good applicability even when the liquid crystal alignment agent is applied to the fine concave-convex structure, it is necessary to use a liquid crystal alignment agent with high wettability to the substrate.

Furthermore, in recent years, the popularization of large-screen liquid crystal panels has been promoted, and larger-scale production lines have been operated to increase the size of substrates. As an advantage of increasing the size of the substrate, it is possible to obtain a plurality of panels from one substrate, which can reduce the process time and cost, or the point of being able to cope with the increase in the size of the liquid crystal panel itself. On the other hand, in the case of forming a liquid crystal alignment film on a large substrate, compared with the previous Compared with the former, the post-baking is prone to temperature unevenness, and the pretilt angle of the liquid crystal alignment film may be deviated due to the temperature unevenness, resulting in a decrease in display quality.

In addition, as a liquid crystal panel, the development of a touch panel-type small display panel represented by a smart phone or a tablet personal computer (tablet PC) is being promoted. Here, in the touch-panel type display panel, in order to further expand the movable area of the touch panel and take into account the miniaturization of the liquid crystal panel, an attempt is being made to realize a narrower frame. Moreover, along with narrowing of the frame of the liquid crystal panel, display unevenness due to the liquid crystal alignment film may be visually recognized around the sealant over the years and the like. In order to realize high-definition and long-life liquid crystal panels, a liquid crystal element in which display unevenness around such a sealant is not easily recognized for a long period of time (highly resistant to bezel unevenness) is desired.

In addition, in the liquid crystal display device, if the residual charge (residual direct current (direct current, DC)) in the liquid crystal alignment film is large, it will cause the so-called afterimage (also referred to as DC afterimage), that is, switching The effect of the previously displayed image remains after the image. In addition, when the liquid crystal display device is operated for a long time, if the direction of the initial alignment deviates from the initial direction when the liquid crystal display device is manufactured, burn-in called alternating current (AC) afterimage may occur. In order to ensure display quality, there is a demand for a liquid crystal display device that reduces such DC afterimages and AC afterimages as much as possible.

This disclosure was made in view of the above-mentioned problems, and one of the objects is to provide a device that has good coating properties on the fine uneven structure, is less susceptible to temperature unevenness during film formation, and can obtain display unevenness around the sealant. Less, and good afterimage characteristics Good liquid crystal alignment agent for liquid crystal elements.

In order to solve the said subject, it has made diligent research and found that the said subject can be solved by making a liquid crystal aligning agent contain the compound which has the structure which couple|bonded the specific group (partial structure) to the benzene ring. Specifically, the following means were employed.

<1> A liquid crystal alignment agent comprising: a polymer component; and a compound [A] selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2) at least one of the

(In formula (1), R ¹ is an alkyl group with 1 to 4 carbons, -CO-CH ₃ , or -R ⁴ -OH (where R ⁴ is an alkanediyl group with 1 to 4 carbons). R ² Be a hydrogen atom or an alkyl group with 1 to 4 carbons. N is 1 or 2. Wherein, when n is 2, R ² is a hydrogen atom. When n is 2, more than one in formula (1) Each R ¹ can be the same or different from each other. In formula (2), R ³ is an alkanediyl group with 1 to 3 carbon atoms)

<2> A method for manufacturing a liquid crystal element, which is a method for manufacturing a liquid crystal element including a liquid crystal alignment film, wherein the liquid crystal alignment film is formed using the liquid crystal alignment agent of <1>.

<3> A liquid crystal alignment film formed using the liquid crystal alignment agent of <1>.

<4> A liquid crystal element including the liquid crystal alignment film of <3>.

The liquid crystal alignment agent disclosed herein also has good wettability and spreadability when applied to a substrate surface having a fine uneven structure, and can form a liquid crystal alignment film uniformly on the substrate surface. In addition, the liquid crystal alignment agent disclosed herein is not easily affected by temperature unevenness during heating during film formation, and thus can obtain a liquid crystal alignment film in which characteristic deviations caused by temperature unevenness are suppressed. Furthermore, according to the liquid crystal alignment agent of this disclosure, the liquid crystal element which has few display unevenness around a sealing compound (good frame unevenness resistance), and is excellent in afterimage characteristics can be obtained.

11: Glass substrate

12: ITO electrode

A: electrode width

B: Distance between electrodes

C: electrode height

FIG. 1( a ) and FIG. 1( b ) are diagrams showing a schematic configuration of an indium tin oxide (Indium Tin Oxide, ITO) electrode substrate for evaluation. FIG. 1( a ) is a plan view, and FIG. 1( b ) is a partially enlarged cross-sectional view.

Hereinafter, each component contained in the liquid crystal alignment agent of this disclosure, and other components arbitrarily blended as needed are demonstrated. The liquid crystal alignment agent is a liquid polymer composition containing a polymer component and a solvent component, and dissolving the polymer component in the solvent component.

<<polymer composition>>

Regarding the polymer component contained in the liquid crystal alignment agent, its main skeleton is not particularly limited, for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide Amides, polyamideimides, polybenzoxazole precursors, polybenzoxazoles, cellulose derivatives, polyacetals, polymerization having structural units derived from monomers having polymerizable unsaturated bonds body (hereinafter also referred to as "polymer (Q)") and other main skeletons. From the viewpoint of sufficiently ensuring the performance of the liquid crystal element, the polymer component is preferably selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and polymer (Q). At least one polymer, especially at least one polymer selected from the group consisting of polyamide acid, polyamide ester and polyimide.

<Polyamide>

Polyamic acid can be obtained by making tetracarboxylic dianhydride and a diamine compound react.

(tetracarboxylic dianhydride)

As a tetracarboxylic dianhydride used for synthesis|combination of polyamic acid, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride etc. are mentioned, for example. As specific examples of these, aliphatic tetracarboxylic dianhydrides include, for example: 1,2,3,4-butane tetracarboxylic dianhydride, etc.; alicyclic tetracarboxylic dianhydrides include, for example: 1,2 ,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl Acetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5 -(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 3 -Oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 2,4,6,8-tetracarboxy Bicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetra Ketone, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, etc.; aromatic tetracarboxylic dianhydride, for example: pyromellitic dianhydride, 4,4'-(hexafluoroisopropylene base) diphthalic anhydride, ethylene glycol bis-trimellitic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4,4'-carbonyl diphthalic anhydride In addition to these, the tetracarboxylic dianhydride described in Unexamined-Japanese-Patent No. 2010-97188 can also be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

(diamine compound)

Examples of the diamine compound used in the synthesis of polyamic acid include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples of these diamines include, for example, m-xylylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and hexamethylenediamine. Amines, etc.; examples of alicyclic diamines include: 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), etc.; examples of aromatic diamines: dodecane Oxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4-diaminobenzene, octadecyloxy-2, 4-Diaminobenzene, Pentadecyloxy-2,5-diaminobenzene, Octadecyloxy-2,5-diaminobenzene, Cholesteryloxy-3,5-diaminobenzene Benzene, Cholesteryloxy-3,5-diaminobenzene, Cholesteryloxy-2,4-diaminobenzene, Cholesteryloxy-2,4-diaminobenzene, 3,5 -Cholesteryl diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostyl 3,5-diaminobenzoate, 3,6-bis(4- Aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 2,4-diamino-N,N-diallylaniline, 4 -(4'-Trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl) Phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid=5ξ-cholestan-3-yl, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO- or *-OCO- (wherein, "*" represents a bond with X ^I ), R ^I is an alkanediyl group with 1 to 3 carbons, R ^II is a single bond or an alkanediyl group with 1 to 3 carbons, a is 0 or 1, b is an integer of 0 to 2, and c is an integer of 1 to 20, d is 0 or 1. Among them, a and b will not be 0 at the same time)

Side-chain diamines such as the compounds shown, diamines having a cinnamic acid structure in the side chain: p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl Thioether, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis(4-amine 1,2-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-amine 1,6-bis(4-aminophenoxy)butane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,10-bis(4- Aminophenoxy)decane, 1,2-bis(4-aminophenyl)ethane, 1,5-bis(4-aminophenyl)pentane, 1,6-bis(4-amine phenyl)hexane, 1,4-bis(4-aminophenylsulfonyl)butane, bis[2-(4-aminophenyl)ethyl]adipic acid, N,N-bis (4-aminophenyl)methylamine, 2,6-diaminopyridine, 1,4-bis(4-aminophenyl)-piperazine, N,N'-bis(4-aminophenyl base)-biphenyl Amine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4' -Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4, 4'-(phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, 4,4'-diaminobenzoylaniline, 4, 4'-diaminostilbene, 4,4'-diaminodiphenylamine, 1,3-bis(4-aminophenethyl)urea, 1,3-bis(4-aminobenzyl base) urea, 1,4-bis(4-aminophenyl)-piperazine, N-(4-aminophenylethyl)-N-methylamine, N,N'-bis(4-amine phenyl)-N,N'-dimethylbenzidine and other main-chain diamines; diaminoorganosiloxanes include, for example, 1,3-bis(3-aminopropyl)-tetramethyl In addition to disiloxane and the like, diamines described in JP-A-2010-97188 can also be used.

(Synthesis of polyamide acid)

The polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic dianhydride and a diamine compound together with a molecular weight modifier as needed. The use ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of polyamic acid is preferably 0.2 to 2 equivalents of the anhydride group of the tetracarboxylic dianhydride relative to 1 equivalent of the amine group of the diamine compound. Equivalent ratio. Examples of molecular weight regulators include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; phenyl isocyanate, isocyanate Monoisocyanate compounds such as naphthyl ester, etc. It is preferable that the usage ratio of a molecular weight modifier shall be 20 mass parts or less with respect to the total of 100 mass parts of tetracarboxylic dianhydrides and diamine compounds used.

The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. at this time The reaction temperature is preferably -20°C to 150°C, and the reaction time is preferably 0.1 hour to 24 hours.

Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. The preferred organic solvent is preferably selected from N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, One or more of the group consisting of γ-butyrolactone, tetramethylurea, hexamethylphosphoryltriamine, m-cresol, xylenol, and halogenated phenol is used as a solvent, or one or more of these are used together with Mixtures with other organic solvents (eg, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount (a) of the organic solvent used is preferably such that the total amount (b) of tetracarboxylic dianhydride and diamine becomes 0.1% by mass to 50% by mass with respect to the total amount of the reaction solution (a+b). quantity. The reaction solution obtained by dissolving the polyamic acid may be directly used for the preparation of the liquid crystal alignment agent, or may be used for the preparation of the liquid crystal alignment agent after separating the polyamic acid contained in the reaction solution.

<Polyuric acid ester>

The polyamic acid ester can be obtained by the following methods, for example: [I] reacting the polyamic acid obtained by the synthesis reaction with an esterifying agent; [II] reacting a tetracarboxylic acid diester with A method of reacting a diamine compound; [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound, etc. The polyamic acid ester contained in the liquid crystal alignment agent may only have the uric acid ester structure, and may also be a partial esterification product in which the uric acid structure and the uric acid ester structure coexist. Furthermore, the reaction solution obtained by dissolving the polyamic acid ester may be directly used for the preparation of the liquid crystal alignment agent, or may be used for the preparation of the liquid crystal alignment agent after separating the polyamic acid ester contained in the reaction solution.

<Polyimide>

Polyimide can be obtained, for example, by dehydrating and ring-closing polyamic acid synthesized as described above, and imidizing it. The polyimide may be a complete imide obtained by dehydrating and ring-closing the entire amide acid structure of the polyamic acid as its precursor, or may be a part of the amide acid structure dehydrated and ring-closed. And a partial amide imide compound in which the amide acid structure and the amide imide ring structure coexist. The polyimide preferably has an imidization rate of 20% to 99%, more preferably 30% to 90%. The imidization rate represents the ratio of the number of imide ring structures to the sum of the number of amide acid structures and the number of imide ring structures of polyimide in percentage. Here, a part of the imide ring may be an isoimide ring.

The dehydration and ring closure of polyamic acid is preferably carried out by the following method: dissolving polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating if necessary. In this method, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as a dehydrating agent, for example. The amount of the dehydrating agent used is preferably 0.01 mol to 20 mol with respect to 1 mol of the amide acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 mol to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closure reaction include the organic solvents exemplified as used in the synthesis of polyamic acid. The reaction temperature of the dehydration ring-closing reaction is preferably 0°C to 180°C. The reaction time is preferably from 1.0 hour to 120 hours. The reaction solution containing polyimide can be directly used in the preparation of liquid crystal alignment agent, and can also be used in the preparation of liquid crystal alignment agent after separation of polyimide. prepare. Polyimides can also be obtained by imidization of polyamide esters.

<Polyamide>

Polyamide can be obtained by the method etc. which make dicarboxylic acid and a diamine compound react. It is preferable that the dicarboxylic acid is subjected to the reaction with the diamine compound after chlorinating the dicarboxylic acid using an appropriate chlorinating agent such as thionyl chloride.

The dicarboxylic acid used in the synthesis of polyamide is not particularly limited, for example, oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methylhexamic acid Aliphatic dicarboxylic acids such as diacid and fumaric acid; alicyclic dicarboxylic acids such as cyclobutane dicarboxylic acid, 1-cyclobutene dicarboxylic acid and cyclohexane dicarboxylic acid; phthalic acid, isophthalic acid, etc. Dicarboxylic acid, terephthalic acid, 5-methylisophthalic acid, 2,5-dimethylterephthalic acid, 4-carboxycinnamic acid, 3,3'-[4,4'-(methylene Aromatic dicarboxylic acids such as di-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid, etc. As a diamine compound used for synthesis|combination, the diamine compound etc. which were illustrated in the description of polyamic acid are mentioned, for example. A dicarboxylic acid and a diamine compound may be used individually by 1 type, and may use it in combination of 2 or more types.

The reaction of dicarboxylic acid and diamine compound is preferably carried out in an organic solvent in the presence of a base. In this case, the ratio of the dicarboxylic acid and the diamine compound used is preferably such that the carboxyl group of the dicarboxylic acid is 0.2 to 2 equivalents relative to 1 equivalent of the amine group of the diamine compound. The reaction temperature is preferably set at 0° C. to 200° C., and the reaction time is preferably set at 0.5 hours to 48 hours. As the organic solvent, for example, tetrahydrofuran, dioxane, toluene, chloroform, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone and the like can be preferably used. Base such as pyridine, triethylamine, N-ethylamine can preferably be used Tertiary amines such as -N,N-diisopropylamine. The usage ratio of the base is preferably 2 mol to 4 mol relative to 1 mol of the diamine compound. The solution obtained by the reaction may be directly used for the preparation of the liquid crystal alignment agent, or may be used for the preparation of the liquid crystal alignment agent after separating the polyamide contained in the reaction solution.

<polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond (polymer (Q))>

As a monomer which has a polymerizable unsaturated bond, the compound which has a (meth)acryl group, a vinyl group, a styryl group, a maleimide group etc. is mentioned, for example. Specific examples of such compounds include unsaturated carboxylic acids such as (meth)acrylic acid, α-ethacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid: alkyl (meth)acrylates, Cycloalkyl (meth)acrylate, Benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Trimethoxysilylpropyl (meth)acrylate, (meth)acrylic acid 2-Hydroxyethyl ester, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4-hydroxy acrylate Unsaturated carboxylic acid esters such as butyl glycidyl ether: Unsaturated polycarboxylic acid anhydrides such as maleic anhydride: (meth)acrylic compounds such as; Aromatic vinyl compounds such as styrene, methylstyrene, and divinylbenzene; 1,3-butadiene, 2-methyl-1,3-butadiene and other conjugated diene compounds; N-methylmaleimide, N-cyclohexylmaleimide, N-benzene Compounds containing maleimide groups such as maleimide groups; etc. In addition, the monomer which has a polymerizable unsaturated bond can be used individually by 1 type or in combination of 2 or more types. In this specification, "(meth)acryl" means to include "acryl" and "methacryl".

The polymer (Q) can be polymerized by making it polymerize in the presence of a polymerization initiator Obtained by polymerization of monomers with sexually unsaturated bonds. As the polymerization initiator used, for example, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2 Azo compounds such as '-azobis(4-methoxy-2,4-dimethylvaleronitrile). It is preferable that the usage ratio of a polymerization initiator shall be 0.01 mass part - 30 mass parts with respect to 100 mass parts of all the monomers used for reaction. The polymerization reaction is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like, preferably diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, and the like. The reaction temperature is preferably set at 30° C. to 120° C., and the reaction time is preferably set at 1 hour to 36 hours. The usage-amount (a) of the organic solvent is preferably such that the total amount (b) of the monomers used in the reaction becomes 0.1% by mass to 60% by mass with respect to the total amount (a+b) of the reaction solution. The polymer solution obtained by the reaction may be directly used for the preparation of the liquid crystal alignment agent, or may be used for the preparation of the liquid crystal alignment agent after separating the polymer (Q) contained in the reaction solution.

The solution viscosity of the polymer used in the preparation of the liquid crystal alignment agent prepared and measured under the conditions described later is preferably 10 mPa. s ~ 800mPa. s, more preferably 15mPa. s~500mPa. s. Furthermore, the solution viscosity (mPa.s) is a good solvent for the polymer used (in the case of polyamic acid, polyamide ester and polyimide, γ-butyrolactone, N- Methyl-2-pyrrolidone, etc.), the value measured at 25°C using an E-type rotational viscometer for a polymer solution with a concentration of 10% by mass.

The polystyrene-equivalent weight average molecular weight (Mw) measured by the gel permeation chromatography (Gel Permeation Chromatography, GPC) of a polymer can be set suitably according to the kind of polymer. For example, in polyamic acid, poly In the case of uric acid ester and polyimide, it is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Also, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, more preferably 5 or less. Furthermore, the polymer used in the preparation of the liquid crystal alignment agent may be only one kind, or two or more kinds may be combined.

<<Compound [A]>>

The liquid crystal alignment agent disclosed herein contains: a polymer component, and at least one compound [A] selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2). The compound [A] can improve the solubility of the polymer component in the solvent, and has properties of moderately low surface tension. By using such a compound [A] as a component of a liquid crystal alignment agent, it is possible to obtain good coatability with a fine concave-convex structure with a good balance, or to cope with temperature variations caused by heating during film formation. Suppression of variation in characteristics, reduction of display unevenness around the sealant (improvement of frame unevenness resistance), reduction of afterimages, etc.

In the formula (1), the alkyl groups with 1 to 4 carbon atoms in R ¹ and R ² can be linear or branched, for example, methyl, ethyl, n-propyl, isopropyl Base, n-butyl, isobutyl, second butyl, third butyl, etc. Among them, the alkyl group having 1 to 4 carbon atoms in R ¹ and R ² is preferably linear, more preferably methyl or ethyl. The alkanediyl group with 1 to 4 carbon atoms in ^R4 can be straight chain or branched, for example: methylene, ethylidene, propane-1,3-diyl, propane-1,2 -diyl, butane-1,4-diyl, butane-1,2-diyl, etc. R ⁴ is preferably methylene or ethylene. R ¹ is preferably a methyl group, an ethyl group or -CO-CH ₃ in terms of improving the frame unevenness resistance.

In terms of making the frame unevenness resistance better, the compound represented by the formula (1) is preferably n=2, or n=1 and R is an alkyl group with ¹ to 4 carbons . In this case, the two groups bonded to the benzene ring are more preferably such that the other group is in the ortho or meta position with respect to one of the groups. Among them, the compound represented by the formula (1) is preferably n=2, more preferably n=2 and R ¹ is methyl, ethyl or -CO-CH ₃ , especially bonded to benzene One of the two "-OR ¹ " of the ring is in the ortho or meta position with respect to the other group.

In the formula (2), R ³ is preferably methylene or ethylene. The compound represented by the above-mentioned formula (2) is preferable because the effect of improving the applicability of the fine uneven structure can be increased.

Compound [A] preferably has a melting point of 25° C. or lower at 1 atmosphere and a boiling point of Above 150°C. The boiling point at 1 atmosphere of the compound [A] is preferably at least 160°C, more preferably at least 165°C, and still more preferably at least 170°C. In addition, the boiling point is more preferably at most 250°C, further preferably at most 245°C. The melting point at 1 atmosphere of the compound [A] is preferably at most 20°C, more preferably at most 15°C, still more preferably at most 10°C. Furthermore, when the compound [A] is a solid compound at normal temperature, the compound [A] may also be used in at least a part of the polymerization medium during the polymerization of the polymer, and the obtained polymer solution may be directly For the preparation of liquid crystal alignment agent.

As specific examples of the compound [A], the compound represented by the formula (1) may include, for example, compounds represented by the following formula (1-1) to formula (1-23); Examples of the compound represented by the formula (2) include compounds represented by the following formula (2-1) and formula (2-2), respectively. Among these, it is more preferred to be selected from the following formula (1-1) ~ formula (1-5), formula (1-7) ~ formula (1-11), formula (1-13), formula (1- 15), at least one of the group consisting of formula (1-17) ~ formula (1-20), formula (1-22), formula (2-1) and formula (2-2). In addition, compound [A] may be used individually by 1 type, and may use it in combination of 2 or more types.

The content ratio of the compound [A] is preferably at least 100 parts by mass, more preferably at least 300 parts by mass, and still more preferably at least 600 parts by mass, based on 100 parts by mass of the total polymer components contained in the liquid crystal alignment agent. above. In addition, the upper limit of the content ratio of the compound [A] is preferably 5000 parts by mass or less, more preferably 4000 parts by mass. Parts by mass or less.

<<Other Ingredients>>

A liquid crystal alignment agent contains a polymer component and a compound [A], and may contain components (henceforth "other components") different from a polymer component and a compound [A] as needed.

<Solvent [B]>

For the purpose of making the afterimage characteristics of the liquid crystal element better, the liquid crystal alignment agent may further include, in addition to the polymer component and the compound [A], a solvent selected from alcohol-based solvents, chain ester-based solvents, ether-based solvents, and At least one solvent in the group consisting of ketone-based solvents (hereinafter also referred to as "solvent [B]").

As specific examples of the solvent [B], alcohol-based solvents include, for example, methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and diacetone alcohol. , 3-methoxy-3-methylbutanol, benzyl alcohol, etc.; chain ester solvents include, for example: ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methoxy Methyl propionate, ethyl ethoxy propionate, diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc.; ether solvents include, for example, diethyl ether, ethyl Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether Ester, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monomethyl ether Acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), 3-methoxy -1-butanol, tetrahydrofuran, diisoamyl ether, etc.; ketone solvents include, for example: acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cycloheptanone, cyclopentanone, 3 -Methylcyclohexanone, 4-methylcyclohexanone, diisobutylketone and the like.

The solvent [B] is preferably at least one selected from the group consisting of ether-based solvents and ketone-based solvents, and more preferably It is at least one selected from the group consisting of ether-based solvents having 8 or less carbon atoms and cyclic ketone-based solvents. Specifically, the solvent [B] is preferably selected from ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, diacetone alcohol, Ethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 3-methoxy-1-butanol and cyclopentyl One of the group consisting of ketones. In addition, as solvent [B], it can use individually by 1 type or in combination of 2 or more types.

The liquid crystal aligning agent may further contain solvents (hereinafter also referred to as "other solvents") different from the solvent [B] as other components. Examples of other solvents include aprotic polar solvents, phenols, halogenated hydrocarbon solvents, hydrocarbon solvents, and the like. Specific examples of other solvents include, for example, aprotic polar solvents: N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidine Ketone, γ-butyrolactone, propylene carbonate, 3-butoxy-N,N-dimethylacrylamide, 3-methoxy-N,N-dimethylacrylamide, 3-hexyl Oxy-N,N-dimethylacrylamide, isopropoxy-N-isopropyl-acrylamide, n-butoxy-N-isopropyl-acrylamide, etc.; phenols include, for example : Phenol, m-cresol, xylenol, etc.; Examples of halogenated hydrocarbon solvents include: methylene chloride, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, etc. ; Hydrocarbon solvent such as can enumerate: Alkanes, heptanes, octanes, benzene, toluene, xylene, etc. Other solvents can be used alone or in combination of two or more.

It is preferable that the content ratio of compound [A] shall be 10 mass % or more with respect to the total amount of compound [A] and solvent [B] contained in a liquid crystal alignment agent. When it is set at 10% by mass or more, the applicability of the liquid crystal alignment agent, the resistance to frame unevenness, the suppression of characteristic deviations caused by temperature variations during film formation, and the reduction of afterimages can be sufficiently obtained. The effect is better in this respect. In terms of improving the wetting spreadability and frame unevenness resistance of the liquid crystal alignment agent, the proportion of the compound [A] relative to the total amount of the compound [A] and the solvent [B] is better It is at least 15% by mass, more preferably at least 20% by mass. In addition, the content ratio of compound [A] is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 80% by mass or less, based on the total amount of compound [A] and solvent [B].

When the liquid crystal alignment agent contains the solvent [B], the content ratio of the solvent [B] is preferably 5% by mass or more relative to the total amount of the compound [A] and the solvent [B] contained in the liquid crystal alignment agent, More preferably, it is 20 mass % or more. In addition, the content of the solvent [B] is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less, based on the total amount of the compound [A] and the solvent [B].

Relative to the total amount of compound [A] and solvent [B] contained in the liquid crystal alignment agent, the content ratio of other solvents is preferably set to 5% by mass or less, more preferably set to 3% by mass or less, and more preferably It is 1 mass % or less, and it is more preferable to set it as 0.05 mass % or less.

As other components that can be contained in the liquid crystal alignment agent, in addition to the above, for example, compounds containing epoxy groups (such as N,N,N',N'-tetraglycidyl-meta- Xylenediamine, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc.), functional silane compounds (such as 3-aminopropyltriethoxy base silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, etc.), antioxidants, metal chelating compounds, hardening catalysts, hardening accelerators, surfactants, Various additives such as fillers, dispersants, and photosensitizers. The compounding ratio of these additives can be suitably selected according to each compound in the range which does not impair the effect of this indication.

Among the components in the liquid crystal alignment agent, the ratio D of the total mass of the compound (A) and the solvent to the total mass of the liquid crystal alignment agent is appropriately selected in consideration of viscosity, volatility, etc., and is preferably 1% by mass to 10% by mass. mass % range. When ratio D is less than 1 mass %, the film thickness of a coating film will be too small and it will become difficult to obtain a favorable liquid crystal alignment film. On the other hand, when the proportion D exceeds 10% by mass, the film thickness of the coating film is too large, making it difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent tends to increase, resulting in poor applicability.

<<Liquid crystal alignment film and liquid crystal element>>

The liquid crystal element disclosed herein includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. Liquid crystal elements can be effectively used in various purposes, such as clocks, portable games, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (Personal Digital Assistant, PDA), digital cameras , mobile phones, smart phones, various monitors, LCD TVs, information displays and other display devices, or dimming films, phase difference films, etc. When used as a liquid crystal display device, the operation mode of the liquid crystal is not particularly limited, for example, it can be applied to twisted nematic (Twisted Nematic, TN) type, super twisted nematic (Super Twisted Nematic, STN) type, vertical alignment type (including vertical alignment-multi-domain vertical alignment (Vertical Alignment-Multi-domain Vertical Alignment, VA-MVA) type, vertical alignment-patterned vertical alignment (Vertical Alignment-Patterned Vertical Alignment, VA- PVA) type, etc.), in-plane switching (In-Plane Switching, IPS) type, fringe field switching (Fringe Field Switching, FFS) type, optically compensated bending (Optically Compensated Bend, OCB) type and other various operation modes.

A liquid crystal display element is taken as an example, and the manufacturing method of a liquid crystal element is demonstrated. The liquid crystal display element can be manufactured by the method including the following steps 1 to 3, for example. In step 1, the board used differs depending on the desired operation mode. In step 2 and step 3, each operation mode is common.

(Step 1: Formation of coating film)

Firstly, the liquid crystal alignment agent is coated on the substrate, and the coated surface is preferably heated to form a coating film on the substrate. As the substrate, for example, glass such as float glass and soda glass can be used; polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly(alicyclic olefin) and other plastic transparent substrates. As the transparent conductive film provided on one side of the substrate, a Nesser (NESA) film (registered trademark of PPG Corporation of the United States) containing tin oxide (SnO ₂ ), a film containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) ITO film etc. In the case of manufacturing a TN-type, STN-type, or VA-type liquid crystal element, two substrates provided with patterned transparent conductive films are used. On the other hand, when manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes including a comb-shaped transparent conductive film or a metal film and a counter substrate provided with no electrodes are used. As the metal film, for example, a film containing metal such as chromium can be used. Coating the liquid crystal alignment agent on the substrate is preferably carried out on the electrode formation surface by offset printing, spin coating, roll coater, flexo printing or inkjet printing.

After applying the liquid crystal alignment agent, for the purpose of preventing dripping of the applied liquid crystal alignment agent, etc., it is preferable to perform preheating (prebaking). The pre-baking temperature is preferably 30° C. to 200° C., and the pre-baking time is preferably 0.25 minutes to 10 minutes. Thereafter, a calcination (post-baking) step is implemented for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amide acid structure of the polymer. The firing temperature (post-baking temperature) is preferably 80° C. to 300° C., and the post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the film thus formed is preferably 0.001 μm to 1 μm. After coating the liquid crystal alignment agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film.

(Step 2: Alignment Processing)

When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, the process (alignment process) which provides liquid crystal alignment capability to the coating film formed in the said process 1 is implemented. Thereby, the alignment ability of a liquid crystal molecule is given to a coating film, and it becomes a liquid crystal alignment film. As the alignment treatment, there may be mentioned: a rubbing treatment in which the coating film is rubbed in a certain direction with a roller wound with a cloth containing fibers such as nylon (nylon), rayon (rayon), and cotton (cotton); Alignment agent The photo-alignment process etc. which apply light irradiation to the coating film formed on the board|substrate, and give a liquid crystal alignment ability to a coating film. On the other hand, in the case of manufacturing a vertical alignment type liquid crystal element, the coating film formed in the step 1 can be directly used as a liquid crystal alignment film, but the coating film can also be Alignment treatment (rubbing treatment, photo-alignment treatment, etc.) is applied. The liquid crystal alignment agent suitable for vertical alignment type liquid crystal display elements can also be suitably used for polymer stabilized alignment (Polymer sustained alignment, PSA) type liquid crystal display elements.

(Step 3: Construction of the Liquid Crystal Cell)

A liquid crystal cell was produced by preparing two substrates on which the liquid crystal alignment film was formed as described above, and arranging liquid crystals between the two substrates facing each other. To manufacture a liquid crystal cell, for example, (1) arrange two substrates facing each other through a gap (spacer) so that the liquid crystal alignment films face each other, and bond the peripheral parts of the two substrates together using a sealant, and The liquid crystal is injected and filled in the cell gap divided by the substrate surface and the sealant, and then the injection hole is sealed. (2) The sealant is applied to a predetermined position on one of the substrates on which the liquid crystal alignment film is formed, and then After dripping liquid crystals on the prescribed positions on the surface of the liquid crystal alignment film, attach another substrate in such a way that the liquid crystal alignment film faces each other, and press and spread the liquid crystal to the entire surface of the substrate (one drop filling , ODF) way) etc. It is desirable to further heat the manufactured liquid crystal cell up to the temperature at which the liquid crystal used becomes an isotropic phase, and then gradually cool it to room temperature to remove the flow alignment at the time of liquid crystal filling.

As the sealing agent, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used. As the spacer, a photo spacer, a beads spacer and the like can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred. In addition, nematic liquid crystals or smectic liquid crystals may be used by adding, for example, cholesteric liquid crystals, chiral reagents, ferroelectric liquid crystals, and the like.

Next, if necessary, a polarizing plate is bonded to the outer surface of the liquid crystal cell. Examples of the polarizing plate include a polarizing film obtained by sandwiching a polarizing film called an "H film" in which polyvinyl alcohol is stretched and aligned on one side to absorb iodine, or a polarizing plate including an H film. Polarizer itself. In this way, a liquid crystal display element was obtained.

[Example]

Hereinafter, based on the examples, the embodiments will be described in more detail, but the present invention is not limitedly interpreted by the following examples.

In the following examples, the weight average molecular weight Mw of the polymer, the imidization rate of polyimide in the polymer solution, the solution viscosity of the polymer solution, and the epoxy equivalent were measured by the following methods. The required amounts of raw material compounds and polymers used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as needed.

[The weight average molecular weight Mw of the polymer]

The weight average molecular weight Mw is a polystyrene conversion value measured by GPC under the following conditions.

Column: TSKgelGRCXLII manufactured by Tosoh Co., Ltd.

Solvent: tetrahydrofuran, or N,N-dimethylformamide solution containing lithium bromide and phosphoric acid

Temperature: 40°C

Pressure: 68kgf/ ^cm2

[Imidation rate of polyimide]

Put the solution of polyimide into pure water, dry the obtained precipitate under reduced pressure at room temperature, dissolve it in deuterated dimethyl sulfide, and use tetramethylsilane as the standard substance, ¹ H-NMR (Nuclear Magnetic Resonance, NMR) was measured. From the obtained ¹ H-NMR spectrum, the imidization rate [%] was calculated by the following formula (1).

Imidization rate [%]=(1-(A ¹ /(A ² ×α)))×100. ． ． (1)

(In formula (1), A ¹ is the peak area of the proton derived from the NH group that appears near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamide Acid) relative to the ratio of the number of other protons in the NH group)

[Solution viscosity of polymer solution]

The solution viscosity (mPa.s) of the polymer solution was measured at 25°C using an E-type rotational viscometer.

[epoxy equivalent]

The epoxy equivalent is measured by the hydrochloric acid-methyl ethyl ketone method described in Japanese Industrial Standards (JIS) C 2105.

The abbreviations of the compounds are as follows. In addition, the compound (wherein X is an integer of 1-8) represented by formula (DA-X) may be simply represented as "compound (DA-X)" below.

[chemical 4]

<Synthesis of Polymer>

[Synthesis Example 1: Synthesis of Polyimide (PI-1)]

22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride (TCA) as tetracarboxylic dianhydride, 8.6 g (0.08 mol) of p-phenylenediamine (PDA) as diamine ), and 10.5 g (0.02 moles) of cholestanyl 3,5-diaminobenzoate were dissolved in 166 g of N-methyl-2-pyrrolidone (NMP), and reacted at 60°C for 6 hours , Obtain a solution containing 20% by mass of polyamic acid. A small amount of the obtained polyamic acid solution was divided and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the measured solution viscosity was 90 mPa. s.

Next, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7% by mass, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110° C. for 4 hours. . After the dehydration ring-closing reaction, use new NMP to replace the solvent in the system (by this operation, the pyridine and acetic anhydride used in the dehydration ring-closing reaction are removed from the system. The same below). A solution of 26% by mass of polyimide (PI-1) with an amination rate of about 68%. A small amount of the obtained polyimide solution was divided, and NMP was added to prepare a solution having a polyimide concentration of 10% by mass. The measured solution viscosity was 45 mPa. s. Next, the reaction solution was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyimide (PI-1).

[Synthesis Example 2: Synthesis of Polyimide (PI-2)]

TCA 110g (0.50 moles) and 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo- 3-furyl)naphtho[1,2-c]furan-1,3-dione 160g (0.50 mol), PDA 91g (0.85 mol) as diamine, 1,3-bis (3-aminopropyl)tetramethyldisiloxane 25g (0.10 mol), and 3,6-bis(4-aminobenzoyloxy)cholestane 25g (0.040 mol), And 1.4 g (0.015 mol) of aniline as a monoamine was dissolved in NMP 960 g, and it reacted at 60 degreeC for 6 hours, and the solution containing polyamic acid was obtained. A small amount of the obtained polyamic acid solution was divided and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the measured solution viscosity was 60 mPa. s.

Next, 2,700 g of NMP was added to the obtained polyamic acid solution, 390 g of pyridine and 410 g of acetic anhydride were added, and a dehydration ring-closure reaction was performed at 110° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new γ-butyrolactone (GBL) to obtain a polyimide (PI-2) with an imidization rate of about 95%15 The mass % solution is about 2,500 g. A small amount of this solution was taken, and NMP was added to prepare a solution having a polyimide concentration of 10% by mass. The measured solution viscosity was 70 mPa. s. Next, the reaction solution was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyimide (PI-2).

[Synthesis Example 3: Synthesis of Polyimide (PI-3)]

In addition to changing the diamine used to 0.08 moles of 3,5-diaminobenzoic acid and 0.02 moles of cholestanoxy-2,4-diaminobenzene, by following the synthesis example 1 to obtain polyamic acid solution in the same way. A small amount of the obtained polyamic acid solution was divided, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass. The measured solution viscosity was 80 mPa. s. Then, imidization was carried out by the same method as in Synthesis Example 1 to obtain a polyimide (PI-3) containing an imidization rate of about 65%. 26 mass % solution. A small amount of the obtained polyimide solution was divided and NMP was added to prepare a solution having a polyimide concentration of 10% by mass, and the measured solution viscosity was 40 mPa. s. Next, the reaction solution was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyimide (PI-3).

[Synthesis Example 4: Synthesis of Polyimide (PI-4)]

The diamine used was changed to 0.06 mol of 4,4'-diaminodiphenylmethane, 0.02 mol of compound (DA-1), and 0.02 mol of compound (DA-2). A polyamide acid solution was obtained by the same method as in Synthesis Example 1 above. A small amount of the obtained polyamic acid solution was divided and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the measured solution viscosity was 60 mPa. s. Next, imidization was carried out in the same manner as in Synthesis Example 1 to obtain a solution containing 26% by mass of polyimide (PI-4) having an imidization rate of about 65%. A small amount of the obtained polyimide solution was divided, and NMP was added to prepare a solution having a polyimide concentration of 10% by mass. The measured solution viscosity was 33 mPa. s. Next, the reaction solution was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyimide (PI-4).

[Synthesis Example 5: Synthesis of Polyimide (PI-5)]

The tetracarboxylic dianhydride used was changed to 0.08 mol of 1,2,3,4-cyclobutane tetracarboxylic dianhydride and 0.02 mol of pyromellitic dianhydride, and the diamine used was changed to 4-Aminophenyl-4-aminobenzoic acid ester (compound (DA-3)) 0.098 mol, and compound (DA-4) 0.002 mol, in addition, by the synthesis example 1 same The method obtains the polyamic acid solution. A small amount of the obtained polyamic acid solution was divided, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass. The measured solution viscosity was 80 mPa. s. Next, imidization was performed by the same method as in Synthesis Example 1 to obtain a solution containing 26% by mass of polyimide (PI-5) having an imidization rate of about 65%. A small amount of the obtained polyimide solution was divided and NMP was added to prepare a solution having a polyimide concentration of 10% by mass, and the measured solution viscosity was 50 mPa. s. Next, the reaction solution was poured into a large excess of methanol to precipitate the reaction product. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyimide (PI-5).

[Synthesis Example 6: Synthesis of Polyamic Acid (PA-1)]

200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB) as tetracarboxylic dianhydride, 2,2'-dimethyl-4,4 210g (1.0 mole) of '-diaminobiphenyl was dissolved in a mixed solvent of 370g of NMP and 3,300g of γ-butyrolactone (GBL), and the reaction was carried out at 40°C for 3 hours to obtain a solid content concentration of 10% by mass. , The solution viscosity is 160mPa. s polyamide solution. Then, the polyamic acid solution was poured into a large excess of methanol and the reaction product was precipitated. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyamic acid (PA-1).

[Synthesis Example 7: Synthesis of Polyamic Acid (PA-2)]

7.0 g (0.031 moles) of TCA as tetracarboxylic dianhydride and 13 g (corresponding to 1 mole relative to 1 mole of TCA) of compound (DA-5) as diamine were dissolved in 80 g of NMP. The reaction was carried out for 4 hours at ℃, thereby obtaining 20 mass % polyamide acid (PA-2) solution. The solution viscosity of the polyamide acid solution is 2,000mPa. s. Furthermore, compound (DA-5) was synthesized according to the description in JP-A-2011-100099. Then, the polyamic acid solution was poured into a large excess of methanol and the reaction product was precipitated. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyamic acid (PA-2).

[Synthesis Example 8: Synthesis of Polyamide Acid (PA-3)]

In addition to changing the diamine used to 0.7 moles of 1,3-bis(4-aminophenethyl)urea (compound (DA-6)) and 0.3 moles of compound (DA-7), A polyamide acid solution was obtained by the same method as in Synthesis Example 6. A small amount of the obtained polyamic acid solution was divided, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass. The measured solution viscosity was 100 mPa. s. Then, the polyamic acid solution was poured into a large excess of methanol and the reaction product was precipitated. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyamic acid (PA-3).

[Synthesis Example 9: Synthesis of polyamide acid (PA-4)]

The tetracarboxylic dianhydride used was changed to 1.0 mole of 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, and the diamine used was changed to p-phenylene 0.3 mol of diamine, 0.2 mol of compound (DA-7), and 0.5 mol of 1,2-bis(4-aminophenoxy)ethane. The method obtains the polyamic acid solution. A small amount of the obtained polyamic acid solution was divided and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the measured solution viscosity was 90 mPa. s. Then, inject the polyamic acid solution into a large amount of excess methanol and allow the reaction product to settle precipitate. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyamic acid (PA-4).

[Synthesis Example 10: Synthesis of Polyamic Acid (PA-5)]

The diamine used was changed to 0.2 mol of 2,4-diamino-N,N-diallylaniline, 0.2 mol of 4,4'-diaminodiphenylamine, and 4,4' - Diaminodiphenylmethane 0.6 mol, and the polyamic acid solution was obtained by the method similar to the said synthesis example 6 except this. A small amount of the obtained polyamic acid solution was divided, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass. The measured solution viscosity was 95 mPa. s. Then, the polyamic acid solution was poured into a large excess of methanol and the reaction product was precipitated. This precipitate was washed with methanol, and dried at 40° C. for 15 hours under reduced pressure to obtain polyamic acid (PA-5).

[Synthesis Example 11: Synthesis of Polyamide Ester (PAE-1)]

Add 0.035 moles of 2,4-bis(methoxycarbonyl)-1,3-dimethylcyclobutane-1,3-dicarboxylic acid to 20ml of thionyl chloride, add a catalytic amount of N, N-dimethylformamide, then stirred at 80°C for 1 hour. Then, the reaction solution was concentrated, and the residue was dissolved in 113 g of γ-butyrolactone (GBL) (this solution was referred to as reaction solution A). Separately, 0.01 mol of p-phenylenediamine, 0.01 mol of 1,2-bis(4-aminophenoxy)ethane, and 0.014 mol of compound (DA-8) were added to 6.9 g of pyridine, 44.5 g of NMP and GBL was dissolved in 33.5 g, and cooled to 0°C. Then, the reaction solution A was slowly added dropwise to this solution over 1 hour, and after the dropwise addition was completed, it was stirred at room temperature for 4 hours. The obtained polyamide ester solution was added dropwise to 800 ml of pure water while stirring, and the precipitated deposit was filtered. Next, rinse with 400 ml of isopropanol (IPA) for 5 times and dried to obtain 15.5 g of polymer powder. The weight average molecular weight Mw of the obtained polyamide ester (PAE-1) was 34,000.

[Synthesis Example 12: Synthesis of polyorganosiloxane (APS-1)]

Add 100.0 g of 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and triethylamine to a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux cooling tube 10.0g, mixed at room temperature. Then, after dripping 100 g of deionized water from the dropping funnel over 30 minutes, it reacted at 80 degreeC for 6 hours, stirring under reflux. After the reaction, the organic layer was taken out, washed with 0.2 mass % ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure, whereby the reaction was obtained in the form of a viscous transparent liquid. Non-toxic polyorganosiloxane (EPS-1). As a result of ¹ H-NMR analysis of this reactive polyorganosiloxane (EPS-1), a peak due to the epoxy group was obtained around chemical shift (δ)=3.2ppm, which was consistent with the theoretical intensity, confirming that No side reaction of epoxy group occurred in the reaction. The weight average molecular weight Mw of the obtained reactive polyorganosiloxane was 3,500, and the epoxy equivalent was 180 g/mol.

Next, 10.0 g of reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, and 4-(dodecyloxy) as a reactive compound were added to a 200 mL three-necked flask. 3.98 g of benzoic acid and 0.10 g of UCAT 18X (trade name, manufactured by San-Apro Co., Ltd.) as a catalyst were reacted at 100° C. for 48 hours while stirring. After the reaction, ethyl acetate was added to the reaction mixture, the obtained solution was washed three times with water, the organic layer was dried with magnesium sulfate, and the solvent was distilled off to obtain liquid crystal alignment polyorganosiloxane (APS-1 ) 9.0 g. The weight average molecular weight Mw of the obtained polymer was 9,900.

[Example 1]

1. Preparation of liquid crystal alignment agent

Anisole (compound a) and butyl cellosolve (BC) were added to the polyimide (PI-1) obtained in Synthesis Example 1 to obtain a polymer concentration of 3.5% by mass and a solvent mixing ratio of It is a solution of compound a:BC=70:30 (mass ratio). After the solution was fully stirred, it was filtered through a filter with a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (S-1). Furthermore, the liquid crystal alignment agent (S-1) is mainly used in the manufacture of vertical alignment type liquid crystal display elements.

2. Evaluation of coating uniformity

The liquid crystal alignment agent (S-1) prepared in the above 1. was coated on the glass substrate using a rotator, and after pre-baking for 1 minute with a heating plate at 80°C, the cavity was replaced with nitrogen at 200 °C in an oven for 1 hour (post-baking), thereby forming a coating film with an average film thickness of 0.1 μm. The surface of the obtained coating film was observed with an atomic force microscope (AFM), the center average roughness (Ra) was measured, and the uniformity of the coating film surface was evaluated. The coating uniformity was evaluated as "good (○)" when Ra was 5 nm or less, "possible (△)" when it was more than 5 nm and less than 10 nm, and "poor (×)" when it was more than 10 nm. ". As a result, it was evaluated as "good" in this Example.

3. Coatability evaluation on fine uneven surface

Using the ITO electrode substrate for evaluation shown in FIG. 1( a ) and FIG. 1( b ), the applicability of the liquid crystal alignment agent to the surface of the fine unevenness was evaluated. As an evaluation ITO electrode substrate, one surface of a glass substrate 11 was used, and a plurality of stripe-shaped ITO electrodes 12 were arranged at predetermined intervals (see FIG. 1( a ) and FIG. 1( b )). In addition, the electrode width A was set to 50 μm, the distance B between electrodes was set to 2 μm, and the electrode height C was set to 0.2 μm. Using a wettability evaluation device LSE-A100T (manufactured by NIC), liquid crystal alignment agent (S-1) was dropped on the electrode formation surface of the ITO electrode substrate for evaluation, and the ease of fusion with the uneven surface of the substrate was evaluated. Spend. At this time, it can be said that the larger the wetting and spreading area S (mm ² /μL) of the droplet relative to the liquid volume, the greater the wetting and spreading of the droplet, and the coating of the liquid crystal alignment agent on the fine uneven surface Sex is better.

In the evaluation, the case where the area S was 15 mm ² /μL or more was rated as “very good (○○)”, and the case where the area S was 10 mm ² /μL or more and less than 15 mm ² /μL was rated as “good (○) ”, when the area S was greater than 5 mm ² /μL and less than 10 mm ² /μL, it was evaluated as “acceptable (△)”, and when the area S was 5 mm ² /μL or less, it was evaluated as “failure (×)”. As a result, in this example, the area S was 10 mm ² /μL, and the applicability to the finely uneven surface was judged to be “good”.

4. Manufacture of Vertical Alignment Liquid Crystal Display Elements

The liquid crystal alignment agent (S-1) was coated on a pair (2 sheets) of glass substrates with transparent electrodes including ITO films using a spinner, and pre-baked for 1 minute using a hot plate at 80°C. Thereafter, the solvent was removed by heating (post-baking) at 200° C. for 1 hour in an oven replaced with nitrogen, and a coating film (liquid crystal alignment film) having a film thickness of 0.08 μm was formed. The coating film was subjected to a rubbing treatment with a rubbing machine having a roller wound with a rayon cloth at a roller rotation speed of 400 rpm, a platen moving speed of 3 cm/sec, and a bristle indentation length of 0.1 mm. Then, perform ultrasonic cleaning in ultrapure water for 1 minute, and then clean and dry at 100°C Dry in an oven for 10 minutes, thereby obtaining a substrate with a liquid crystal alignment film. This operation was repeated to obtain a pair (two sheets) of substrates having a liquid crystal alignment film. Furthermore, the rubbing treatment is a weak rubbing treatment performed for the purpose of controlling the collapse of the liquid crystal and performing alignment division in a simple manner.

An epoxy resin adhesive containing alumina balls with a diameter of 3.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of one of the substrates by screen printing, and then the liquid crystals of the pair of substrates were aligned. The film faces faced each other, were laminated and bonded under pressure, and were heated at 150° C. for 1 hour to thermally harden the adhesive. Next, after filling the gap between the liquid crystal injection port and the substrate with negative-type liquid crystal (MLC-6608 manufactured by Merck), the liquid crystal injection port was sealed with an epoxy-based adhesive. Alignment, it was heated at 150°C for 10 minutes and then slowly cooled to room temperature. Furthermore, the polarizing plates were bonded to both outer surfaces of the substrate so that the polarization directions of the two polarizing plates were perpendicular to each other, thereby manufacturing a liquid crystal display element.

5. Evaluation of the deviation characteristic (post-baking margin) of the pretilt angle with respect to the temperature unevenness of the post-baking

According to the method of 4., the pretilt angles of the liquid crystal display elements obtained by preparing the liquid crystal alignment film at different post-baking temperatures (120° C., 180° C. and 230° C.) were respectively measured. The measured value at 230°C is set as the reference pretilt angle θp, and the pretilt angle relative to the post-baking temperature unevenness is evaluated from the difference Δθ(=|θp-θa|) between the reference pretilt angle θp and the measured value θa deviation characteristics. Furthermore, it can be said that the smaller the Δθ is, the smaller the variation of the pretilt angle with respect to the temperature unevenness is, and the more excellent it is. In the mensuration of pretilt angle, according to non-patent literature (T.J. Schaeffer et al. (T.J.Scheffer et.al.) Journal of Applied Physics (J. Appl. Phys.) Vol. 19, p. 2013 (vo.19, p.2013) (1980)), the liquid crystal molecules measured by the crystal rotation method using He-Ne laser light relative to the substrate surface The value of the tilt angle is set to the pretilt angle [°]. In the evaluation, the case where △θ was 0.2° or less was regarded as "good (○)", the case of greater than 0.2° and less than 0.5° was regarded as "acceptable (△)", and the case of 0.5° or more was regarded as "poor". (×)". As a result, in this Example, when the post-baking temperature was set at 180° C., the post-baking margin was evaluated as “good”, and when the post-baking temperature was set at 120° C., it was evaluated as “possible”.

6. Evaluation of frame unevenness resistance

According to the method of said 4., a vertical alignment type liquid crystal display element was manufactured using a liquid crystal alignment agent (S-1). The obtained vertical alignment liquid crystal display element was stored at 25° C. and 50% RH for 30 days, and then driven with an AC voltage of 5 V to observe the lighting state. During the evaluation, if no brightness difference (darker or whiter) is visually recognized around the sealant, it is rated as "very good (○○)", and if the brightness difference (darker or whiter) is visually recognized but lights up If the difference in brightness disappears within 10 minutes after being turned on, it is set as "Good (○)". If the difference in brightness does not disappear within 10 minutes after turning on but disappears within 20 minutes after turning on, it is set as "OK (△)". The case where the brightness difference was visually recognized after 20 minutes passed was made into "failure (x)". As a result, the liquid crystal display element was judged as "possible".

7. Evaluation of AC afterimage characteristics

In addition to the aspect that the electrode structure is used as the ITO electrode (electrode 1 and electrode 2) of the other two systems that can switch the application/non-application of voltage to another, and the aspect that the polarizing plate is not attached, use the above-mentioned 4. A liquid crystal cell for evaluation was produced by the same method. The liquid crystal cell for evaluation was placed under the condition of 60°C, and no voltage was applied to the electrode 2. voltage, an AC voltage of 10 V was applied to the electrode 1 for 300 hours. Immediately after 300 hours had elapsed, an AC voltage of 3 V was applied to both the electrode 1 and the electrode 2, and the difference ΔT [%] in light transmittance between both electrodes was measured. At this time, the case where ΔT was less than 2% was evaluated as "good (○)", the case where 2% or more and less than 3% was evaluated as "acceptable (△)", and the case where 3% or more was The condition evaluation was "poor (x)". As a result, it was evaluated as "good" in this Example.

8. Evaluation of DC afterimage characteristics

Place the liquid crystal cell for evaluation prepared in the above 7. at 60°C, apply a DC voltage of 0.5 V to the electrode 1 for 24 hours, and obtain the voltage remaining in the electrode 1 immediately after the DC voltage is cut off by the flicker elimination method (residual DC voltage). At this time, the case where the residual DC voltage was less than 100 mV was rated as "good (○)" in DC afterimage characteristics, the case where it was 100 mV or more and less than 300 mV was rated as "acceptable (△)", and the case where it was 300 mV or more was rated as "good (△)". "Bad (×)". As a result, it was evaluated as "good" in this Example.

[Example 2～Example 4 and Comparative Example 1～Comparative Example 5]

A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the formulation composition was as described in the following Table 1, respectively. In addition, various evaluations were performed in the same manner as in Example 1 using the prepared liquid crystal alignment agent. The evaluation results are shown in Table 2 below.

[Example 5]

1. Preparation of liquid crystal alignment agent

Except having changed the recipe composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent (S-5). Furthermore, the liquid crystal alignment agent (S-5) is mainly used Used in the manufacture of horizontal alignment liquid crystal display elements.

2. Evaluation of liquid crystal alignment agent

Except having used the liquid crystal aligning agent (S-5), it carried out similarly to Example 1, and evaluated the coating uniformity and the applicability to the surface of a fine uneven|corrugated surface. These results are shown in Table 2 below.

3. Manufacture of rubbed FFS type liquid crystal display element

Use a spinner to apply the liquid crystal alignment agent (S-5) to a glass substrate on which a plate electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) are sequentially laminated on one side, and to the opposite side where no electrode is provided. Each surface of the glass substrate was heated (pre-baked) for 1 minute on a hot plate at 80°C. Then, drying (post-baking) was performed for 1 hour in a 200° C. oven in which the inside of the cavity was replaced with nitrogen, and a coating film having an average film thickness of 0.08 μm was formed. Next, the surface of the coating film was rubbed with a rubbing machine having a roller wound with rayon cloth at a roller rotation speed of 500 rpm, a platform moving speed of 3 cm/sec, and a bristle indentation length of 0.4 mm. Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then dried in a clean oven at 100° C. for 10 minutes, thereby obtaining a substrate with a liquid crystal alignment film.

Then, for a pair of substrates with a liquid crystal alignment film, leave a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film is formed, and apply an epoxy resin adhesive with alumina balls with a diameter of 5.5 μm by screen printing. . Then, the substrates were laminated and bonded by pressure, and the adhesive was thermally cured at 150° C. for 1 hour. Next, after filling nematic liquid crystal (MLC-6221 manufactured by Merck) between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy-based adhesive. Furthermore, in order to remove the liquid crystal Flow alignment at the time of injection was heated at 120° C. and then gradually cooled to room temperature to manufacture a liquid crystal cell. Furthermore, when a pair of substrates are stacked, the rubbing directions of the respective substrates are made antiparallel. In addition, the polarizing plates were bonded together so that the polarization directions of the two polarizing plates were parallel to and perpendicular to the rubbing direction, respectively. In addition, regarding the top electrode, the line width of the electrode was set to 4 μm, and the distance between the electrodes was set to 6 μm. In addition, the top electrode is a four-system driving electrode using the electrode A, the electrode B, the electrode C, and the electrode D. In this case, the bottom electrode functions as a common electrode that acts on all the driving electrodes of the four systems, and the areas of the driving electrodes of the four systems serve as pixel areas.

4. Evaluation of rubbed FFS type liquid crystal display element

Except having used the rubbed FFS type liquid crystal display element or liquid crystal cell produced by the method of said 3., it evaluated similarly to Example 1 for post-baking margin, AC afterimage characteristic, and DC afterimage characteristic. Moreover, using the liquid crystal alignment agent (S-5), the rubbed FFS type liquid crystal display element was manufactured by the method of said 3. description, and it evaluated similarly to Example 1 for frame unevenness resistance. These results are shown in Table 2 below.

[Example 6, Example 7]

A liquid crystal alignment agent (S-6) and a liquid crystal alignment agent (S-7) were prepared in the same manner as in Example 1, respectively, except that the formulation composition was changed as described in the following Table 1. In addition, except that the liquid crystal alignment agent (S-6) and the liquid crystal alignment agent (S-7) were used respectively, the coating uniformity and the applicability to the fine uneven surface were evaluated in the same manner as in Example 1, and the same as in Example 5 In the same manner, a rubbed FFS type liquid crystal display element or liquid crystal cell was produced, and various evaluations were performed. These results are shown in Table 2 below.

[Example 8]

1. Preparation of liquid crystal alignment agent

Except having changed the recipe composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent (S-8). Furthermore, the liquid crystal alignment agent (S-8) is mainly used in the manufacture of PSA-type liquid crystal display elements.

2. Evaluation of liquid crystal alignment agent

Except having used the liquid crystal aligning agent (S-8), it carried out similarly to Example 1, and evaluated the coating uniformity and the applicability to the surface of a fine uneven|corrugated surface. These results are shown in Table 2 below.

3. Preparation of liquid crystal composition

To 10 g of nematic liquid crystals (MLC-6608 manufactured by Merck, Inc.), 5 mass % of a liquid crystal compound represented by the following formula (L1-1) and 0.3 mass % of the following formula (L2- 1) The photopolymerizable compound shown in 1) was mixed, and liquid crystal composition LC1 was obtained by this.

4. Manufacture of PSA type liquid crystal display element

Except for using the liquid crystal alignment agent (S-8), a pair (2 sheets) of substrates with liquid crystal alignment films was obtained in the same manner as described in "4. Production of vertical alignment type liquid crystal display elements" in Example 1. . Next, a liquid crystal cell was produced in the same manner as in Example 1, except that the liquid crystal composition LC1 prepared above was used instead of MLC-6608, and a polarizing plate was not bonded. Next, to the liquid crystal cell obtained above, AC 10V with a frequency of 60 Hz was applied between the electrodes and the liquid crystal was driven, and was irradiated with an irradiation dose of 50,000 J/ ^m2 using an ultraviolet irradiation device using a metal halide lamp as a light source. ultraviolet light. In addition, the said irradiation amount is the value measured using the light meter which measures based on wavelength 365nm. Furthermore, the polarizing plates were bonded to both outer surfaces of the substrate so that the polarization directions of the two polarizing plates were perpendicular to each other, thereby manufacturing a liquid crystal display element.

5. Evaluation of PSA type liquid crystal display element

Except having used the PSA-type liquid crystal display element or liquid crystal cell produced by the method as described in said 4., the post-baking margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated similarly to Example 1. Moreover, using the liquid crystal alignment agent (S-8), a PSA type liquid crystal display element was manufactured according to the method of said 4. description, and it evaluated similarly to Example 1 for frame unevenness resistance. These results are shown in Table 2 below.

[Example 9～Example 11, Example 21, Example 22 and Comparative Example 6]

Except having changed the formula composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent, respectively. In addition, except that each liquid crystal alignment agent was used, the uniformity of coating and the coatability to the fine uneven surface were evaluated in the same manner as in Example 1, and a PSA-type liquid crystal display element or liquid crystal cell was produced in the same manner as in Example 8, and Make various evaluations. These results are shown in Table 2 below.

[Example 12]

1. Preparation of liquid crystal alignment agent

Except having changed the recipe composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent (S-12). Furthermore, the liquid crystal alignment agent (S-12) is mainly used in the manufacture of optical vertical alignment type liquid crystal display elements.

2. Evaluation of liquid crystal alignment agent

Except having used the liquid crystal aligning agent (S-12), it carried out similarly to Example 1, and evaluated the coating uniformity and the applicability to the fine uneven surface. These results are shown in Table 2 below.

3. Manufacture of optical vertical alignment type liquid crystal display element

In addition to using a liquid crystal alignment agent (S-12), instead of the rubbing treatment, a Hg-Xe lamp and a Glan-Taylor prism were used to irradiate the film with polarized ultraviolet rays. An optical vertical alignment type liquid crystal display element was produced by the same method as described in "4. Production of a vertical alignment type liquid crystal display element". In addition, polarized ultraviolet rays were irradiated from a direction inclined at 40° from the normal line of the substrate, the irradiation dose was set to 200 J/m ² , and the polarization direction was set to p-polarized light. The said irradiation amount is the value measured using the light meter which measures based on wavelength 313nm.

4. Evaluation of optical vertical alignment type liquid crystal display elements

The post-baking margin, AC afterimage characteristics, and DC afterimage characteristics were evaluated in the same manner as in Example 1 except that the optical vertical alignment type liquid crystal display element or liquid crystal cell produced by the method described in 3. above was used. Moreover, using the liquid crystal alignment agent (S-12), according to the method described in said 3., the optical vertical type liquid crystal display element was manufactured, and it evaluated similarly to Example 1 for frame unevenness resistance. These results are shown in Table 2 below.

[Example 13 and Example 14]

Except having changed the formula composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent, respectively. In addition, except that each liquid crystal alignment agent was used, the uniformity of coating and the coatability to the surface of fine unevenness were evaluated in the same manner as in Example 1, and an optical vertical alignment type liquid crystal display element or liquid crystal cell was produced in the same manner as in Example 12. , to evaluate the post-baking margin, frame unevenness resistance, AC afterimage characteristics and DC afterimage characteristics. These results are shown in Table 2 below.

[Example 15]

1. Preparation of liquid crystal alignment agent

Except having changed the recipe composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent (S-15). Furthermore, the liquid crystal alignment agent (S-15) is mainly used in the manufacture of light-level liquid crystal display elements.

2. Evaluation of liquid crystal alignment agent

Except having used the liquid crystal aligning agent (S-15), it carried out similarly to Example 1, and evaluated the coating uniformity and the applicability to the fine uneven surface. These results are shown in Table 2 below.

3. Manufacture of optical FFS type liquid crystal display element

In addition to using a liquid crystal alignment agent (S-15), instead of the rubbing treatment, the film was irradiated with polarized ultraviolet rays using a Hg-Xe lamp and a Glan-Taylor fluoride. An optical FFS type liquid crystal display element was manufactured by the same method as described in "Manufacture of a liquid crystal display element". In addition, polarized ultraviolet rays were irradiated from a direction perpendicular to the substrate, and the irradiation dose was set to 10,000 J/m ² , and the polarization direction was set to a direction perpendicular to the direction of the rubbing treatment in Example 5. The said irradiation amount is the value measured using the light meter which measures based on wavelength 254nm.

4. Evaluation of optical FFS type liquid crystal display element

The post-baking margin, AC afterimage characteristics, and DC afterimage characteristics were evaluated in the same manner as in Example 1 except that an optical FFS type liquid crystal display element or liquid crystal cell produced by the method described in 3. above was used. In addition, using the liquid crystal alignment agent (S-15), an optical FFS type liquid crystal display element was manufactured by the method described in said 3., and it evaluated similarly to Example 1 for frame unevenness resistance. These results are shown in Table 2 below.

[Example 16~Example 20]

Except having changed the formula composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent, respectively. In addition, except for using each liquid crystal alignment agent, the coating uniformity and the coatability to the fine uneven surface were evaluated in the same manner as in Example 1, and an optical FFS type liquid crystal display element or liquid crystal cell was produced in the same manner as in Example 15, and perform various evaluations. These results are shown in Table 2 below.

[Example 23]

1. Preparation of liquid crystal alignment agent

Except having changed the formula composition as described in following Table 1, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent (S-23). Furthermore, the liquid crystal alignment agent (S-23) is mainly used in the manufacture of TN-mode liquid crystal display elements.

2. Evaluation of liquid crystal alignment agent

Except having used the liquid crystal aligning agent (S-23), it carried out similarly to Example 1, and evaluated the coating uniformity and the applicability to the surface of fine uneven|corrugated. These results are shown below Table 2.

3. Manufacture of TN type liquid crystal display element

Using a liquid crystal alignment agent (S-23), using a rubbing machine with a roller wound with rayon cloth, the rubbing process is carried out under the conditions of a roller speed of 500 rpm, a platform moving speed of 3 cm/second, and a wool pressing length of 0.4 mm. Other than that, a pair (2 sheets) of substrates having a liquid crystal alignment film was obtained in the same manner as described in "4. Production of Vertical Alignment Type Liquid Crystal Display Element" in Example 1. Then, instead of MLC-6608, a positive liquid crystal (MLC-6221 manufactured by Merck) was used, and when a pair of substrates were stacked, the rubbing directions of the respective substrates were made to be perpendicular, and the polarization directions of the two polarizers were set to A TN mode liquid crystal display element was produced in the same manner as in Example 1 except for the direction parallel to the rubbing direction of each substrate.

4. Evaluation of TN type liquid crystal display element

The post-baking margin, AC afterimage characteristics, and DC afterimage characteristics were evaluated in the same manner as in Example 1 except that a TN-type liquid crystal display element or liquid crystal cell produced by the method described in 3. above was used. Moreover, using the liquid crystal alignment agent (S-23), the TN type liquid crystal display element was manufactured by the method of said 3. description, and it evaluated similarly to Example 1 for frame unevenness resistance. These results are shown in Table 2 below.

In Table 1, the numerical value of a polymer component shows the compounding ratio (mass part) of each polymer with respect to the total 100 mass parts of polymer components used for preparation of a liquid crystal alignment agent. The value in the ratio column of compound [A], "solvent [B], and other solvents" represents 100 parts by mass of each compound relative to the total of compound [A], solvent [B], and other solvents used in the preparation of the liquid crystal alignment agent The deployment ratio (parts by mass). "-" indicates that the compound is not used. The abbreviations of the compounds are as follows.

(Compound [A])

a: Anisole (boiling point (bp): 154°C, melting point (melting point: mp): -38°C)

b: 2-methoxytoluene (bp: 177°C, mp: -47°C)

c: o-ethoxyanisole (bp: 217°C, mp: -1°C)

d: 1,3-diethoxybenzene (bp: 235°C, mp: 10°C)

e: m-cresyl acetate (bp: 212°C, mp: 12°C)

f: 1,2-methylenedioxybenzene (bp: 172°C, mp: -10°C)

(Solvent [B] and other solvents)

g: N-methyl-2-pyrrolidone

h: o-xylene

i: m-cresol

j: 2-ethoxyphenol

k: butyl cellosolve

m: 3-methoxy-1-butanol

n: cyclopentanone

[Table 2]

It can be seen from Table 2 that in Examples 1 to 23 containing compound [A], the coating uniformity, concave-convex coating property, post-baking margin, frame unevenness resistance, and image sticking properties were all "very good". ", "Good" or "Possible", various characteristics have been improved in a well-balanced manner. Especially when using compound b with 2 substituents on the benzene ring In the example of compound e, the effect of improving the unevenness of the frame is high, and in the examples of compound d and compound e, the effect of improving the coatability of the fine uneven surface is also high. Moreover, in the Example which used the compound f which has a condensed ring, the effect of improving the applicability to the fine uneven|corrugated surface was high. On the other hand, Comparative Examples 1 to 6, which did not contain the compound [A], were inferior to Examples in terms of applicability to the surface of fine unevenness. In addition, the uniformity of the coating film surface of Comparative Example 1, Comparative Example 3 to Comparative Example 6 is worse than that of Examples, and the resistance to frame unevenness of Comparative Example 4 and Comparative Example 5 is worse than that of Examples.

11: Glass substrate

12: ITO electrode

A: electrode width

B: Distance between electrodes

C: electrode height

Claims (7)

A liquid crystal alignment agent comprising: a polymer component and a compound A selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2) At least one, and comprising a group selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, and a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond At least one of the group is used as the polymer component,

In formula (1), R ¹ is an alkyl group with 1 to 4 carbons or -CO-CH ₃ ; R ² is a hydrogen atom or an alkyl group with 1 to 4 carbons; n is 1 or 2; where n is In the case of 2, R ² is a hydrogen atom; in the case of n being 2, multiple R ¹ in formula (1) may be the same or different from each other; in formula (2), R ³ is carbon number 1-3 of alkanediyl. The liquid crystal alignment agent described in claim 1 of the patent application, wherein the compound A has a melting point below 25°C and a boiling point above 150°C at 1 atmosphere. The liquid crystal alignment agent as described in item 1 or item 2 of the scope of patent application, which further contains: solvent B, which is selected from the group consisting of alcohol-based solvents, chain ester-based solvents, ether-based solvents, and ketone-based solvents at least one of the The liquid crystal alignment agent according to claim 3, wherein the content of the compound A relative to the total amount of the compound A and the solvent B is 10% by mass or more. A method of manufacturing a liquid crystal element, which is a method of manufacturing a liquid crystal element including a liquid crystal alignment film, and using the liquid crystal alignment agent described in any one of the first to fourth items of the scope of the patent application to form the liquid crystal alignment film . A liquid crystal alignment film, which is formed by using the liquid crystal alignment agent described in any one of items 1 to 4 of the scope of the patent application. A liquid crystal element, which includes the liquid crystal alignment film described in item 6 of the scope of application.

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