TWI791817B - Liquid crystal alignment agent and manufacturing method thereof, liquid crystal alignment film and manufacturing method thereof, and liquid crystal element - Google Patents

Abstract

The present invention provides a liquid crystal alignment agent capable of obtaining a liquid crystal element having good liquid crystal alignment and good AC afterimage characteristics. The liquid crystal alignment agent contains the first polymer, the second polymer, and the compound (A). Here, the first polymer has an acidic functional group, and the compound (A) has a partial structure represented by formula (1-1), a partial structure represented by formula (1-2), and a partial structure represented by formula (1-3) At least one nitrogen-containing structure in the group consisting of the partial structure represented by the formula (1-4) and the partial structure represented by the formula (1-4) (wherein, the partial structure represented by the formula (1-2) and the partial structure of the formula (1 -3) A compound that does not have at least one of an acidic functional group and an electron-withdrawing group except for nitrogen-containing aromatic heterocycles in at least any one of the partial structures shown. When the compound (A) has a partial structure represented by formula (1-1), the second polymer has a nitrogen-containing aromatic heterocycle.

Description

Liquid crystal alignment agent and its manufacturing method, liquid crystal alignment film and its manufacturing method, and liquid crystal element

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal element.

Liquid crystal elements are widely used in televisions, mobile devices, various monitors, and the like. Moreover, in a liquid crystal element, a liquid crystal alignment film is used in order to control the alignment of the liquid crystal molecule in a liquid crystal cell. A liquid crystal alignment film is usually formed using a polymer composition (liquid crystal alignment agent) in which a polymer component is dissolved in a solvent. As a method of obtaining an organic film having liquid crystal alignment confinement force, a method of rubbing an organic film, a method of obliquely vapor-depositing silicon oxide, a method of forming a monomolecular film with a long-chain alkyl group, and A method of irradiating a photosensitive organic film with light (photo-alignment method), etc.

In recent years, in order to further improve the performance of liquid crystal elements, various liquid crystal alignment agents have been proposed by setting the polymer component as a blend of two or more types, or improving the monomer structure (for example, refer to patent Document 1 to Patent Document 3). Patent Document 1 proposes a liquid crystal alignment agent including polyamide ester and polyamide acid as polymer components, and the weight average molecular weight of the polyamide ester is smaller than that of the polyamide acid. According to the liquid crystal alignment agent described in this patent document 1, it is described that the fine unevenness generated on the film surface in the liquid crystal alignment film can be reduced, and the liquid crystal alignment and electrical characteristics in the liquid crystal display element can be improved.

In addition, Patent Document 2 proposes that the liquid crystal alignment agent contains polyamic acid or polyimide obtained by using 4,4'-diaminodiphenylamine to improve voltage retention characteristics or image sticking. reduce. Patent Document 3 discloses that a polyimide precursor or polyimide obtained by using a diamine having a urea bond is contained in a liquid crystal alignment agent, thereby obtaining a liquid crystal alignment agent having good liquid crystal alignment, rubbing resistance, and charge accumulation. Less liquid crystal alignment film. [Prior art literature] [Patent Document]

[Patent Document 1] International Publication No. 2011/115078 [Patent Document 2] Japanese Patent No. 4052307 [Patent Document 3] International Publication No. 2013/008906

[Problem to be Solved by the Invention]

In the case of obtaining a liquid crystal alignment film by photo-alignment treatment, there is a tendency that the alignment restriction force of liquid crystal molecules is insufficient compared with rubbing treatment, and an afterimage called alternating current (AC) afterimage tends to occur easily. film. The AC afterimage is an afterimage generated when the direction of the initial alignment deviates from the original direction of the liquid crystal element due to long-term driving of the liquid crystal element. As a liquid crystal element, it is desired to sufficiently reduce AC afterimages in order to meet demands for further performance enhancement in recent years.

This invention is made in view of the said subject, and one object is to provide the liquid crystal aligning agent which can obtain the liquid crystal element with favorable liquid crystal alignment property and favorable AC afterimage characteristic. [Means to solve the problem]

The present invention employs the following means to solve the above-mentioned problems.

（式（1-1）中，關於R¹ 及R² ，R¹ 為藉由氮原子或氧原子而鍵結於吡啶環的一價基團，且R² 為一價有機基，或者R¹ 及R² 表示R¹ （其中，R¹ 藉由氮原子或氧原子而鍵結於吡啶環）與R² 相互結合並與R¹ 及R² 分別所鍵結的碳原子一同構成的環結構。m為1～3的整數，n為0～2的整數，m+n≦3。於m為2或3的情況下，多個R¹ 可相同亦可不同，於n為2的情況下，多個R² 可相同亦可不同。式（1-4）中，R³ 為碳數1～5的烷基。r為0～3的整數。於r為2或3的情況下，多個R³ 可相同亦可不同。式（1-1）～式（1-4）中的「*」表示結合鍵） ＜2＞ 一種液晶配向劑的製造方法，其包括將所述第1聚合體、所述第2聚合體、及所述化合物（A）混合的步驟。 ＜3＞ 一種液晶配向膜的製造方法，其使用所述＜1＞的液晶配向劑於基板上形成塗膜，對所述塗膜進行光照射而賦予液晶配向能力。 ＜4＞ 一種液晶配向膜，其是使用所述＜1＞的液晶配向劑而形成。 ＜5＞ 一種液晶元件，其包括所述＜4＞的液晶配向膜。 [發明的效果]<1> A liquid crystal alignment agent comprising: a first polymer, a second polymer, and a compound (A), and the first polymer has an acidic functional group, and the second polymer is compatible with the second polymer 1 different polymers, wherein the compound (A) has a partial structure represented by the following formula (1-1), a partial structure represented by the following formula (1-2), the following formula ( At least one nitrogen-containing structure in the group consisting of partial structures represented by 1-3) and partial structures represented by the following formula (1-4) (wherein, will include the following formula (1-2) Excluding nitrogen-containing aromatic heterocycles in at least any one of the partial structures represented by the following formula (1-3) and at least one of the partial structures represented by the following formula (1-3), and not having at least one of an acidic functional group and an electron-withdrawing group (wherein, when the compound (A) has a partial structure represented by the following formula (1-1), the second polymer has a nitrogen-containing aromatic heterocycle). [chemical 1]

(In formula (1-1), regarding R ¹ and R ² , R ¹ is a monovalent group bonded to the pyridine ring through a nitrogen atom or an oxygen atom, and R ² is a monovalent organic group, or R ¹ and R ² represents a ring structure in which R ¹ (wherein R ¹ is bonded to the pyridine ring through a nitrogen atom or an oxygen atom) and R ² are combined with each other and the carbon atoms to which R ¹ and R ² are bonded respectively. m is an integer of 1 to 3, n is an integer of 0 to 2, m+n≦3. When m is 2 or 3, a plurality of R ¹ may be the same or different, and when n is 2, A plurality of R ² may be the same or different. In formula (1-4), R ³ is an alkyl group with 1 to 5 carbon atoms. R is an integer of 0 to 3. When r is 2 or 3, a plurality of R ³ may be the same or different. "*" in formula (1-1) to formula (1-4) represents a bonding bond) , the step of mixing the second polymer and the compound (A). <3> The manufacturing method of a liquid crystal alignment film which forms a coating film on a board|substrate using the liquid crystal alignment agent of said <1>, irradiates the said coating film with light, and provides a liquid crystal alignment ability. <4> A liquid crystal alignment film formed using the liquid crystal alignment agent of <1> above. <5> A liquid crystal element including the liquid crystal alignment film of the above <4>. [Effect of the invention]

According to the liquid crystal alignment agent of the present invention, the liquid crystal alignment agent containing the first polymer having an acidic functional group and the second polymer different from the first polymer contains a specific basic compound, thereby achieving liquid crystal alignment. Liquid crystal elements with excellent performance and afterimage characteristics (especially AC afterimage characteristics).

Hereinafter, each component contained in a liquid crystal alignment agent, and other components arbitrarily blended as needed are demonstrated. The liquid crystal alignment agent contains a polymer component and the compound (A). The liquid crystal alignment agent can be obtained by mixing the polymer component and the compound (A), and is preferably a liquid polymer composition obtained by dissolving the polymer component in a solvent.

＜＜Polymer composition＞＞ A liquid crystal alignment agent contains a 1st polymer and a 2nd polymer different from a 1st polymer as a polymer component. The first polymer has an acidic functional group. The acidic functional group is a functional group capable of releasing hydrogen ions in an aqueous solution. Specific examples thereof include carboxylic acid groups, phenolic hydroxyl groups, sulfonic acid groups, phosphoric acid groups, phosphorous acid groups, phosphonic acid groups, etc. . Among these, a carboxylic acid group is preferable at the point that it is easy to introduce into a polymer, and that the effect of improving the liquid crystal alignment by the addition of the compound (A) is higher. In addition, as long as the second polymer is different from the first polymer, the case where the second polymer has an acidic functional group is not excluded.

The first polymer and the second polymer are preferably polymers having different acidities. Specifically, the first polymer is preferably higher in acidity than the second polymer. In this case, the first polymer with higher acidity (lower basicity) tends to exist in the lower layer, and the second polymer with lower acidity (higher basicity) tends to exist in the upper layer. The phase separation property of the polymer component is preferable in this respect. Examples of combinations of the first polymer and the second polymer include the following Aspect 1 and Aspect 2. (Aspect 1) The number of acidic functional groups differs between the first polymer and the second polymer, and the first polymer has more acidic functional groups than the second polymer. (Aspect 2) The number of basic functional groups differs between the first polymer and the second polymer, and the second polymer has more basic functional groups than the first polymer.

（式（4）中，X¹ 為四價有機基，X² 為二價有機基）The main skeleton of the first polymer and the second polymer is not particularly limited, for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, Polyamide imide, polybenzoxazole (benzoxazole) precursor, polybenzoxazole, cellulose derivatives, polyacetal, styrene-maleimide copolymer, poly(methyl) Polymers with main skeleton such as acrylate. In addition, (meth)acrylate means to include acrylate and methacrylate. Among these, the first polymer is preferably selected from the group having a partial structure represented by the following formula (4) in terms of improving the liquid crystal alignment and afterimage reduction in the obtained liquid crystal element. Composed of polymers (including polyamic acid, polyamic acid ester, and polyimide), polyorganosiloxane, and polymers having structural units derived from monomers with polymerizable unsaturated bonds At least one of the groups, more preferably a polymer having a partial structure represented by the following formula (4). Among these, the first polymer is preferably at least one selected from the group consisting of polyamic acid and polyimide having an imidization rate of 80% or less, and is particularly preferably polyamic acid. [Chem 2]

(In formula (4), X ¹ is a tetravalent organic group, X ² is a divalent organic group)

On the other hand, the second polymer is preferably selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosilicon in terms of fully improving the various properties of the obtained liquid crystal element. At least one polymer selected from the group consisting of oxane, and a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond, particularly preferably selected from polyamic acid, polyamic acid ester, At least one of the group consisting of polyimide and polyorganosiloxane.

(Polyamic acid) When a 1st polymer and a 2nd polymer are polyamic acid, this polyamic acid can be obtained by making a tetracarboxylic dianhydride and a diamine compound react. Furthermore, in the formula (4), X ¹ is a tetravalent group derived from tetracarboxylic dianhydride, and X ² is a divalent group derived from a diamine compound.

(Tetracarboxylic dianhydride) The tetracarboxylic dianhydride used in the synthesis of polyamic acid includes, for example, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. . 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-tetracarboxybicyclo [3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraone , cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc.; examples of aromatic tetracarboxylic dianhydride include: pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene ) diphthalic anhydride, ethylene glycol bis-trimellitic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4,4'-carbonyl diphthalic anhydride, etc. , in addition to these, the tetracarboxylic dianhydride etc. which are described in Unexamined-Japanese-Patent No. 2010-97188 can also be used. In addition, tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

（式（E-1）中，X^I 及X^II 分別獨立地為單鍵、-O-、*-COO-或*-OCO-（其中，「*」表示與X^I 的結合鍵），R^I 為碳數1～3的烷二基，R^II 為單鍵或碳數1～3的烷二基，a為0或1，b為0～2的整數，c為1～20的整數，d為0或1。其中，a及b不會同時成為0）；(Diamine compound) As a diamine compound used for the synthesis|combination of polyamic acid, aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane etc. are mentioned, for example. Specific examples of these diamine compounds include, for example, aliphatic diamines: m-xylylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine Diamine, etc.; Examples of alicyclic diamine include: 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine); Examples of aromatic diamine include: dodeca Alkoxy-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-diamine phenyl, cholestenyloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3, Cholesteryl 5-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, a compound represented by the following formula (E-1), with cinnamic acid in the side chain Structured diamines and other side-chain diamines: [Chem. 3]

(In formula (E-1), X ^I and X ^II are 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 become 0 at the same time);

p-Phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 4-aminophenyl-4-aminobenzoate, 4, 4'-Diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy ) ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-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-aminophenoxy)decane, 1,2-bis(4-aminophenoxy) ) ethane, 1,5-bis(4-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,4-bis(4-aminophenylsulfonyl) base) 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)-benzidine, 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'-diaminobenzamide aniline, 4,4'-diaminodiphenylamine, 1,3-bis (4-aminophenethyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,4-bis(4-aminophenyl)-piperazine, N-(4-amino Main-chain diamines such as phenylethyl)-N-methylamine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, etc.; diamine-based silicone Oxanes include, for example, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like, and diamines and the like described in JP-A-2010-97188 can also be used. .

When synthesizing polyamic acid, by using the diamine that contains carboxylic acid group, can obtain a kind of by the condensation reaction of tetracarboxylic dianhydride and diamine compound and then have and derive from tetracarboxylic dianhydride A polymer of carboxylic acid groups with different carboxylic acid groups. Specific examples of carboxylic acid group-containing diamines include, for example, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4' -Diaminobiphenyl-2,2'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether -3,3'-dicarboxylic acid, etc. When synthesizing polyamic acid, in the case of using a carboxylic acid group-containing diamine, the usage ratio is preferably set at 1 mole relative to the total amount of diamine compounds used in the synthesis of polyamic acid. % or more, more preferably 10 mol% to 60 mol%. In addition, carboxylic acid group containing diamine can be used individually by 1 type or in combination of 2 or more types.

(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 usage 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. The reaction temperature at this time 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 in combination with other Mixture of 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 the tetracarboxylic dianhydride and the diamine compound becomes 0.1% by mass to 50% by mass with respect to the total amount of the reaction solution (a+b). quantity. In this manner, a reaction solution in which polyamic acid is dissolved can be obtained. The reaction solution 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.

(polyimide) When the first polymer and the second polymer are polyimides, the polyimides can be obtained, for example, by dehydrating and ring-closing polyamic acid synthesized as described above and imidizing them. The polyimide contained in the liquid crystal alignment agent of the present invention is, for example, a partial imide obtained by dehydrating and ring-closing a part of the amide acid structure of the polyamic acid as its precursor. When the first polymer is polyimide, its imidization rate is preferably 30%-80%, more preferably 50%-75%. When the second polymer is polyimide, the imidization rate thereof is preferably from 30% to 99%, more preferably from 50% to 90%. The imidization rate is a percentage representing the ratio of the number of imide ring structures of polyimide to the total number of the number of amide acid structures and the number of imide ring structures. 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. It is preferable that the usage-amount of a dehydrating agent shall be 0.01 mol - 20 mol with respect to 1 mol of the amide acid structure of 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 from 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 for the preparation of the liquid crystal alignment agent, or can be used for the preparation of the liquid crystal alignment agent after separating the polyimide.

(a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond) When the first polymer and the second polymer are polymers having structural units derived from monomers having polymerizable unsaturated bonds (hereinafter, also referred to as "polymer (M)"), as having polymer Monomers with permanent unsaturated bonds, for example, polymerizable unsaturated bond groups such as (meth)acryl groups, vinyl groups, styryl groups, maleimide groups, and compounds with acidic functional groups (hereinafter , also known as "monomer (m1)"). As specific examples of such compounds, for example, unsaturated carboxylic acids such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, and vinyl benzoic acid; (E)-3-(4 -((3-((meth)acryloxy)propyl)oxy)phenyl)acrylic acid, (E)-3-(4-((6-((meth)acryloxy )hexyl)oxy)phenyl)acrylic acid, (E)-3-(4-((8-((meth)acryloxy)octyl)oxy)phenyl)acrylic acid, etc. Unsaturated carboxylic acids with bases; aromatic vinyl compounds such as p-vinylphenol and m-vinylphenol, etc. A monomer can be used individually by 1 type or in combination of 2 or more types.

When synthesizing the polymer (M), the above-mentioned monomer (m1) may be used together with other monomers other than the monomer (m1) as long as the effect of the present invention is not impaired. Specific examples of such other monomers include, for example, alkyl (meth)acrylates, cycloalkyl (meth)acrylates, benzyl (meth)acrylates, 2-ethyl (meth)acrylates, Hexyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate Unsaturated carboxylic acid esters such as methyl ester, 3,4-epoxybutyl (meth)acrylate, and 4-hydroxybutyl glycidyl acrylate; unsaturated polycarboxylic anhydrides such as maleic anhydride; (meth)acrylic acid Compounds; aromatic vinyl compounds such as styrene, methylstyrene and divinylbenzene; conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; N- Methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, compounds represented by the following formula (m2-1) to formula (m2-3), etc. contain Maleimide-based compounds, etc. Other monomers can be used alone or in combination of two or more. [chemical 4]

The polymer (M) can be obtained, for example, by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. 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 monomethyl 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 amount (a) of the organic solvent used 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 of the reaction solution (a+b). . The polymer solution obtained by the reaction may be directly used in the preparation of the liquid crystal alignment agent, or may be used in the preparation of the liquid crystal alignment agent after separating the polymer (M) contained in the reaction solution.

(polyorganosiloxane) Polyorganosiloxane can be obtained by hydrolyzing and condensing a hydrolyzable silane compound, for example. As the silane compound used in the synthesis of polyorganosiloxane, for example, tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyl Diethoxysilane and other alkoxysilane compounds; 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(3-ring Hexylamino) propyltrimethoxysilane and other alkoxysilane compounds containing nitrogen and sulfur; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3 - Epoxy-containing silane compounds such as glycidyloxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc.; 3-(meth)propene Acyloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, Alkoxysilane compounds containing unsaturated bonds such as vinyltriethoxysilane and p-styryltrimethoxysilane; trimethoxysilyl propyl succinic anhydride, etc. These hydrolyzable silane compounds can be used individually by 1 type or in combination of 2 or more types.

The hydrolysis/condensation reaction is performed by reacting one or more of the silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. When carrying out the reaction, the usage ratio of water is preferably 1 mol to 30 mol relative to 1 mol of the silane compound (total amount). As a catalyst to be used, an acid, an alkali metal compound, an organic base, a titanium compound, a zirconium compound etc. are mentioned, for example. The amount of the catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be set appropriately, for example, it is preferably 0.01-3 times the mole relative to the total amount of the silane compound. Examples of the organic solvent to be used include hydrocarbons, ketones, esters, ethers, alcohols, and the like, and among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The usage ratio of the organic solvent is preferably 10 to 10,000 parts by mass relative to a total of 100 parts by mass of the silane compounds used in the reaction.

The hydrolysis/condensation reaction is preferably carried out, for example, by heating with an oil bath or the like. At this time, it is preferable to set heating temperature to 130 degreeC or less, and it is preferable to set heating time to 0.5 hour - 12 hours. After completion of the reaction, if necessary, the organic solvent layer separated from the reaction solution is dried with a desiccant, and the solvent is removed, whereby the target polyorganosiloxane can be obtained. In addition, the synthesis|combination method of polyorganosiloxane is not limited to the said hydrolysis-condensation reaction, For example, the method etc. which make a hydrolyzable silane compound react in presence of oxalic acid and alcohol can also be performed.

From the viewpoint of sufficiently obtaining the effect of improving polymer solubility, liquid crystal alignment, and afterimage characteristics by compounding (A), the amount of acidic functional groups (mmol/g) contained in the first polymer is relatively small. Preferably, it is 0.1 mmol/g - 10 mmol/g, More preferably, it is 1 mmol/g - 10 mmol/g, More preferably, it is 2 mmol/g - 5 mmol/g. In the above-mentioned aspect 1, there is no particular limitation as long as the amount of acidic functional groups contained in the second polymer is smaller than the amount of acidic functional groups contained in the first polymer. From the viewpoint of sufficiently obtaining the effect of improving liquid crystal alignment and afterimage characteristics by the compound (A), the amount of the acidic functional groups contained in the second polymer relative to the amount of the acidic functional groups contained in the first polymer The amount is preferably at most 0.7 molar equivalents, more preferably at most 0.5 molar equivalents, still more preferably at most 0.3 molar equivalents. In addition, "the amount of the acidic functional group which the 2nd polymer has is less than the amount of the acidic functional group which the 1st polymer has" also includes the meaning that the second polymer does not have the acidic functional group. In the case of the above-mentioned aspect 2, if the basicity of the second polymer is higher than that of the first polymer, the amount of acidic functional groups that the second polymer has may be more or less than that of the first polymer , or may be the same as the first polymer.

In the case of the above-mentioned aspect 2, if the amount of basic functional groups (mmol/g) contained in the second polymer is greater than the amount of basic functional groups contained in the first polymer, there is no particular limitation, preferably The amount is at least 1.5 molar equivalents, more preferably at least 1.8 molar equivalents, and still more preferably at least 2.0 molar equivalents, based on the amount of basic functional groups that the first polymer has. Here, examples of basic functional groups include amino groups, groups containing nitrogen-containing heterocycles (for example, aromatic heterocycles such as pyridine rings and imidazole rings; aliphatic heterocycles such as piperidine rings and pyrrolidine rings), Guanidine, etc. From the viewpoint of more fully inducing the phase separation of the first polymer and the second polymer, the second polymer preferably has a functional group including a nitrogen-containing aromatic heterocycle as a basic functional group, and more preferably has Functional groups containing pyridine rings. Especially when the compound (A) is a compound having a nitrogen-containing structure represented by the formula (1-1), the second polymer has a functional group containing a nitrogen-containing aromatic heterocycle, thereby inducing the second It is preferable that the phase separation effect of the first polymer and the second polymer is high.

Specific examples of combinations of polymer components in the case of the above-mentioned aspect 1 include, for example, the following aspects (1-1) to (1-5), and the like in the case of the above-mentioned aspect 2. Specific examples include, for example, aspects of the following (2-1) to (2-2), but are not limited to these aspects. (1-1) An aspect in which the first polymer is polyamic acid and the second polymer is polyimide. (1-2) An aspect in which the first polymer is polyamic acid and the second polymer is polyamic acid ester. (1-3) An aspect in which the first polymer is polyamic acid and the second polymer is polyorganosiloxane. (1-4) An aspect in which the first polymer is polyamic acid and the second polymer is (meth)acrylate. (1-5) The first polymer and the second polymer are polyamic acid, and the first polymer has more acidic functional groups than the second polymer. (2-1) The first polymer and the second polymer are polyamic acid, the second polymer has a nitrogen-containing aromatic heterocycle, and the first polymer does not have a nitrogen-containing aromatic heterocycle. (2-2) The first polymer and the second polymer are polyamic acid, the first polymer and the second polymer have amine groups (secondary amine groups or tertiary amine groups), and the second polymer An aspect having more amine groups than the first polymer.

In addition, the method of obtaining the polymer which has a basic functional group is not specifically limited, As an example, the method of superposing|polymerizing using the monomer which has a basic functional group is mentioned. For example, when obtaining the polyamic acid which has a basic functional group, it is preferable to use the diamine which has a basic functional group in terms of the high degree of freedom of the selectivity of a monomer. As specific examples of diamines having basic functional groups, for example, bis(4-aminophenyl)amine, N,N-bis(4-aminophenyl)-N-methylamine, N, N'-bis(4-aminophenyl)-1,4-phenylenediamine, N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzene Diamine, N,N'-bis(4-aminophenyl)-biphenyl-4,4'-diamine, N,N'-bis(4-aminophenyl)-N,N'-bis Methylbiphenyl-4,4'-diamine, N,N'-bis(4-aminophenyl)-ethylenediamine, N,N'-bis(4-aminophenyl)-N,N '-Dimethylethylenediamine, N,N'-bis(4-aminophenyl)-piperazine, bis(5-amino-2-pyridyl)amine, N,N-bis(5-amine Base-2-pyridyl)-N-methylamine, N,N'-bis(5-amino-2-pyridyl)-1,4-phenylenediamine, N,N'-bis(5-amine Base-2-pyridyl)-N,N'-dimethyl-1,4-phenylenediamine, N,N'-di(5-amino-2-pyridyl)-biphenyl-4,4' -Diamine, N,N'-bis(5-amino-2-pyridyl)-N,N'-dimethylbiphenyl-4,4'-diamine, N,N'-bis(5- Amino-2-pyridyl)-ethylenediamine, N,N'-bis(5-amino-2-pyridyl)-N,N'-dimethylethylenediamine, N,N'-bis( 5-amino-2-pyridyl)-piperazine, etc. When synthesizing polyamic acid, in the case of using a diamine having a basic functional group, the usage ratio is preferably 20 molar relative to the total amount of diamine compounds used in the synthesis of polyamic acid. mol% or more, more preferably 40 mol% or more.

Regarding the blending ratio of the first polymer in the liquid crystal alignment agent, relative to the amount of the second polymer contained in the liquid crystal alignment agent, it is preferably set to 30% by mass or more, more preferably set to 40% by mass or more, Furthermore, it is more preferable to set it as 50 mass % or more. In addition, a liquid crystal alignment agent may contain one kind of 2nd polymer independently, and may contain 2 or more types of 2nd polymer.

(photoalignment group) In the case where the polymer component of the liquid crystal alignment agent contains a polymer having a photoalignment group, the organic film formed using the liquid crystal alignment agent can be provided with liquid crystal alignment ability by the photoalignment method, which is preferable in this respect . Here, the photoalignment group refers to a group capable of imparting various properties to the film by photoreaction such as photoisomerization reaction, photodimerization reaction, photo Fries rearrangement reaction, or photodecomposition reaction by irradiation with light. Anisotropic functional groups. In the polymer blend (polymer blend) of the first polymer and the second polymer, in terms of improving the liquid crystal alignment of the obtained liquid crystal element and the improvement effect of AC afterimage reduction, it is better than It is preferable to contain a polymer having a photoalignment group as the second polymer. In this case, the case where the first polymer has a photoalignment group is not excluded.

Specific examples of photoalignment groups include, for example, azobenzene-containing groups containing azobenzene or its derivatives as a basic skeleton, and cinnamic acid or its derivatives (cinnamic acid structure) containing azobenzene-containing groups as a basic skeleton. A group of cinnamic acid structure, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing a benzophenone or a derivative thereof as a basic skeleton, a group containing Coumarin-containing groups containing coumarin or its derivatives as the basic skeleton, cyclobutane-containing structures containing cyclobutane or its derivatives as the basic skeleton, stilbene or its derivatives as the basic skeleton A stilbene-containing group, a phenylbenzoate-containing group containing phenylbenzoate or a derivative thereof as a basic skeleton, and the like. Among these, the photoalignment group is preferably selected from groups containing azobenzene, groups containing cinnamic acid structures, groups containing chalcone, groups containing stilbene, and groups containing cyclobutane. structure, and at least one of the group consisting of a phenylbenzoate-containing group is preferably a cinnamic acid-containing structure in terms of high sensitivity to light and ease of introduction into polymers. groups or structures containing cyclobutane.

A polymer having a photoalignment group can be obtained, for example, by polymerization using a monomer having a photoalignment group. In addition, when the polyorganosiloxane is used as a polyorganosiloxane having a photoalignment group in the side chain, the following method can be used: at least a part of the raw material uses an epoxy group-containing silane compound, and the side chain has a photoalignment group. Epoxy-group-containing polyorganosiloxane (hereinafter, also referred to as "epoxy-group-containing polysiloxane"), and then the epoxy-group-containing polysiloxane is reacted with a carboxylic acid having a photoalignment group. This method is convenient and preferable in that the introduction rate of the photoalignment group can be increased.

The content ratio of the photo-alignment group is appropriately set according to the type of the photo-alignment group so as to impart the desired liquid crystal alignment ability to the coating film. It is preferable that the content ratio of the photoalignment group is 5 mol % or more, and it is more preferable that it is 10 mol % - 60 mol % of all structural units of the polymer of a group. In the case where the photoalignment group has a cyclobutane-containing structure, it is preferable to set the content ratio of the photoalignment group to 50 mol % or more with respect to all the constituent units of the polymer having the photoalignment group, More preferably, it is 80 mol% or more.

When made into a solution with a concentration of 10% by mass, the solution viscosity of the polymer used in the preparation of the liquid crystal alignment agent is preferably a solution viscosity of 10 mPa·s to 800 mPa·s, more preferably a solution viscosity of 15 mPa·s to 800 mPa·s. The solution viscosity is 500 mPa s. Furthermore, the solution viscosity (mPa·s) is a good solvent for the polymer used (for example, γ-butyrolactone, N-formaldehyde in the case of polyamic acid, polyamide ester, and polyimide) Base-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) of the polymer measured by gel permeation chromatography (Gel Permeation Chromatography, GPC) is appropriately set according to the type of the polymer. For example, in the case of polyamic acid, polyamic acid ester, and polyimide, it is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. In addition, 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. In the case of polyorganosiloxane, the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably in the range of 100 to 50,000, more preferably in the range of 200 to 20,000. In the case of the polymer (M), the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably 250 to 500,000, more preferably 500 to 100,000.

＜＜Compound [A]＞＞ The liquid crystal alignment agent contains a polymer component and a compound (A) different from the first polymer and the second polymer. Compound (A) is a compound that does not have acidic functional groups (such as carboxylic acid groups, phenolic hydroxyl groups, sulfonic acid groups, phosphoric acid groups, phosphorous acid groups, phosphonic acid groups), and does not have electron-withdrawing groups (such as carbonyl groups, ester groups, etc.) , nitro, nitrile, halogen) compounds, or compounds without acidic functional groups and electron-withdrawing groups.

Regarding R ¹ and R ² of the formula (1-1), when R ¹ is a monovalent group bonded to a pyridine ring via a nitrogen atom or an oxygen atom, and R ² is a monovalent organic group (Hereafter, expressed as "requirement a"), R ¹ is preferably "-NR ²⁶ R ²⁷ " or "-OR ²⁸ " (wherein, regarding R ²⁶ and R ²⁷ , each independently represents a hydrogen atom or a carbon number of 1 to A monovalent organic group of 10, or a ring structure in which R ²⁶ and R ²⁷ are combined with each other and the carbon atoms to which R ²⁶ and R ²⁷ are bonded. R ²⁸ is a hydrogen atom or a monovalent organic group with 1 to 10 carbons base). The monovalent organic groups of R ²⁶ , R ²⁷ and R ²⁸ are preferably an alkyl group having 1 to 5 carbons or a monovalent group having -O- between the carbon-carbon bonds of the alkyl group.

Among these, R ¹ is preferably a group bonded to a pyridine ring via a nitrogen atom in terms of high solubility in solvents and the ability to further enhance the effect of improving the liquid crystal alignment of the obtained liquid crystal element. group. Preferable specific examples of R ¹ include: R ²⁶ and R ²⁷ of "-NR ²⁶ R ²⁷ " are hydrogen atoms, methyl or ethyl groups, R ²⁸ of "-OR ²⁸ " is a hydrogen atom , methyl or ethyl group, 1-pyrrolidinyl, 1-piperidinyl, and 4-morpholinyl, among these, a group bonded to a pyridine ring via a nitrogen atom is particularly preferred.

When R ¹ and R ² satisfy requirement a, the monovalent organic group of R ² is preferably an alkyl group having 1 to 5 carbons, or a monovalent organic group having -O- between the carbon-carbon bonds of the alkyl group. group, more preferably an alkyl group having 1 to 3 carbon atoms. In this case, m is preferably 1 or 2, more preferably 1. n is preferably 0 or 1, more preferably 0.

Regarding R ¹ and R ² , it means that R ¹ (where R ¹ is bonded to the pyridine ring through a nitrogen atom or an oxygen atom) and R ² are bonded to each other and to the carbon atom to which R ¹ and R ² are bonded respectively In the case of a constituted ring structure (hereinafter referred to as "requirement b"), R ¹ is preferably bonded to the pyridine ring via a nitrogen atom. m is preferably 1, and n is preferably 1 or 2. In the formula (1-4), R ³ is preferably methyl or ethyl, more preferably methyl. r is preferably 0 or 1, more preferably 0.

（式（2-1）中，R¹¹ 為「-NR²⁶ R²⁷ 」或「-OR²⁸ 」，R¹² 為碳數1～10的一價有機基。R²⁶ 、R²⁷ 及R²⁸ 分別獨立地為氫原子或碳數1～10的一價有機基。其中，R²⁶ 與R²⁷ 亦可相互結合並與R²⁶ 及R²⁷ 所鍵結的氮原子一同形成環結構。式（2-2）中，R¹³ 、R¹⁴ 、R¹⁵ 及R¹⁶ 分別獨立地為氫原子或碳數1～10的一價有機基，R¹³ 、R¹⁴ 、R¹⁵ 及R¹⁶ 中的兩個以上的有機基亦可鍵結而形成環結構（其中，將含氮芳香族雜環除外）。式（2-3）中，R¹⁷ 、R¹⁸ 、R¹⁹ 及R²⁰ 分別獨立地為氫原子、胺基或碳數1～10的一價有機基，R²¹ 為氫原子或碳數1～10的一價有機基，R¹⁷ 、R¹⁸ 、R¹⁹ 、R²⁰ 及R²¹ 中的兩個以上的有機基亦可鍵結而形成環結構（其中，將含氮芳香族雜環除外）。式（2-4）中，R²² 、R²³ 、R²⁴ 及R²⁵ 分別獨立地為氫原子或碳數1～10的一價有機基。其中，R¹¹ ～R²⁵ 不具有酸性官能基及拉電子性基中的至少一者。m及n與所述式（1-1）為相同含義，R³ 及r與所述式（1-4）為相同含義）Specific examples of the compound (A) include compounds selected from compounds represented by the following formula (2-1), compounds represented by the following formula (2-2), and compounds represented by the following formula (2-3). At least one of the group consisting of a compound and a compound represented by the following formula (2-4). Wherein, the case where the compound represented by the following formula (2-2) is a nitrogen-containing heterocyclic compound and the case where the compound represented by the following formula (2-3) is a nitrogen-containing heterocyclic compound are derived from compound (A) except in. [chemical 5]

(In formula (2-1), R ¹¹ is "-NR ²⁶ R ²⁷ " or "-OR ²⁸ ", and R ¹² is a monovalent organic group with 1 to 10 carbons. R ²⁶ , R ²⁷ and R ²⁸ are independently Ground is a hydrogen atom or a monovalent organic group with 1 to 10 carbons. Among them, R ²⁶ and R ²⁷ can also combine with each other and form a ring structure together with the nitrogen atom to which R ²⁶ and R ²⁷ are bonded. Formula (2-2 ), R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom or a monovalent organic group with 1 to 10 carbons, and two or more of R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are organic Groups can also be bonded to form a ring structure (except for nitrogen-containing aromatic heterocycles).In formula (2-3), R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ are independently hydrogen atoms, amino groups or a monovalent organic group with 1 to 10 carbons, R ²¹ is a hydrogen atom or a monovalent organic group with 1 to 10 carbons, two or more organic groups among R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ Groups can also be bonded to form a ring structure (except for nitrogen-containing aromatic heterocycles). In formula (2-4), R ²² , R ²³ , R ²⁴ and R ²⁵ are independently hydrogen atoms or carbon numbers 1 to 10 monovalent organic groups. Among them, R ¹¹ to R ²⁵ do not have at least one of an acidic functional group and an electron-withdrawing group. m and n have the same meaning as the formula (1-1), and R ³ and r have the same meaning as the formula (1-4) above)

In the formula (2-2), the monovalent organic groups of R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are preferably an alkyl group having 1 to 10 carbons, more preferably an alkyl group having 1 to 3 carbons. In the formula (2-3), the monovalent organic groups of R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ are preferably alkyl groups with 1 to 10 carbons, more preferably alkyl groups with 1 to 3 carbons alkyl. In the formula (2-4), the monovalent organic groups of R ²² , R ²³ , R ²⁴ and R ²⁵ are preferably alkyl groups with 1 to 3 carbon atoms, more preferably methyl groups.

The boiling point of the compound (A) at 1 atmosphere is preferably at least 60°C, more preferably at least 80°C. In this case, a sufficient amount of compound (A) can remain in the alignment film even after heating during pre-baking, and the improvement effect of compound (A) can be further enhanced. Words are better. In addition, in order to fully remove compound (A) from the alignment film by heating during post-baking, the boiling point of compound (A) at 1 atmosphere is preferably 300°C or lower, more preferably 250°C or lower, and further Preferably it is below 230°C.

As a preferred specific example of the compound (A), the compound represented by the formula (2-1) includes, for example, compounds represented by the following formula (3-1-1) to formula (3-1-9) Compounds, etc.; the compounds represented by the formula (2-2) include, for example, compounds represented by the following formula (3-2-1) and formula (3-2-2); the formula (2- 3) Compounds represented by the following formulas (3-3-1) to formulas (3-3-8) can be listed, for example; compounds represented by the formula (2-4) can be listed, for example Compounds represented by the following formula (3-4-1), etc. [chemical 6]

Regarding the compounding ratio of the compound (A), from the viewpoint of sufficiently obtaining the effect of improving polymer solubility, liquid crystal alignment, and afterimage characteristics, relative to the first polymer and the second polymer contained in the liquid crystal alignment agent The total number of acidic functional groups is preferably formulated at a ratio of 0.1 molar equivalent to 15 molar equivalent, more preferably formulated at a ratio of 0.2 molar equivalent to 12 molar equivalent, and more preferably formulated at a ratio of 0.5 molar equivalent to 10 molar equivalent Ratio deployment of ear equivalents. In addition, compound (A) can be used individually by 1 type or in combination of 2 or more types.

Here, in the liquid crystal alignment agent of the polymer blend of the first polymer and the second polymer, the first polymer is compatible with the second polymer, whereby the liquid crystal alignment of the obtained liquid crystal element is sometimes Sex is not enough. Especially in the case of a polymer blend of a polymer having an acidic functional group (the first polymer) and a polymer with a lower acidity than the polymer (the second polymer), the first polymer and the second The compatibility of the polymer is high, and there is a concern that the phase separation property will decrease. In this respect, by formulating the compound (A) as a basic compound in the liquid crystal alignment agent, the first polymer is more likely to exist in the lower layer of the alignment film, and the phase separation from the second polymer can be improved , as a result, it is estimated that the performance of the liquid crystal alignment film can be improved.

＜＜Other ingredients＞＞ A liquid crystal alignment agent contains a polymer component and a compound (A), and may contain other components as needed.

<Solvent> As a liquid crystal alignment agent, it is preferable to dissolve a polymer component in a solvent. Examples of the solvent used include: a solvent with high polymer solubility and leveling properties (hereinafter also referred to as "first solvent"), a solvent with good wetting and spreading properties (hereinafter also referred to as "second solvent") solvent"), and mixed solvents of these. As specific examples of the solvent, the first solvent includes, for example: N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactamide, N,N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone, ethyl carbonate, propylene carbonate, N-ethyl-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, 1,3-dimethyl -2-imidazolidinone, 3-butoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-dimethylpropionamide, etc.; Examples of the second solvent include ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, and diethylene 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, cyclopentanone, butyl lactate, butyl acetate , methyl methoxy propionate, ethyl ethoxy propionate, isoamyl propionate, isoamyl isobutyrate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, di Isopentyl ether etc. In addition, these solvents may be used individually by 1 type, and may use it in mixture of 2 or more types.

When using a mixed solvent of the first solvent and the second solvent as the solvent component, the ratio of the first solvent to the total amount of the solvent components used in the preparation of the liquid crystal alignment agent is preferably 10% by mass to 10% by mass. 95% by mass, more preferably 15% by mass to 80% by mass. The usage ratio of the second solvent is preferably 5% by mass to 90% by mass, more preferably 20% by mass to 85% by mass, based on the total amount of solvent components used in the preparation of the liquid crystal alignment agent.

In the liquid crystal alignment agent disclosed herein, water-based polymer composition can also be prepared by using water as a solvent component. In this case, the usage-amount of an organic solvent can be reduced, and it can be set as the liquid crystal aligning agent more excellent in an environmental point or a safety point, and it is preferable in this point. As the solvent component, water can be used alone, but from the viewpoint of improving the solubility of the polymer in the solvent and improving the applicability to the substrate, it is preferably water-soluble and the surface tension A mixed solvent of a solvent lower than water and water is more preferably a mixed solvent of water and alcohol. As the alcohol used, for example, ethanol, propanol, isopropanol, 1-methoxy-2-propanol, diacetone alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, butyl cellosolve ( Ethylene glycol monobutyl ether), propylene glycol monoethyl ether, ethyl lactate, 1-hexanol, 4-methyl-2-pentanol, etc. In this case, with respect to the total amount of solvent contained in the liquid crystal alignment agent, the use ratio of water is preferably 20% by mass or more, more preferably 40% by mass to 95% by mass, and still more preferably 40% by mass to 95% by mass. 60% by mass to 90% by mass.

As other components contained in the liquid crystal alignment agent, in addition to the solvent, for example, compounds containing epoxy groups (such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, N,N ,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc.), functional silane compounds (such as 3-aminopropyltriethoxysilane, N-(2- Aminoethyl)-3-aminopropylmethyldimethoxysilane, etc.), antioxidants, metal chelating compounds, hardening catalysts, hardening accelerators, surfactants, fillers, dispersants, optical enhancers sensitizer etc. The compounding ratio of other components can be suitably selected according to each compound in the range which does not impair the effect of this invention.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) can be appropriately selected in consideration of viscosity, volatility, etc., preferably 1 mass % to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the coating film is too small, and it is difficult to obtain a favorable liquid crystal alignment film. On the other hand, when the solid content concentration 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 components can be effectively used in various purposes, such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (Personal Digital Assistant, PDA), digital Various display devices such as cameras, mobile phones, smart phones, various monitors, LCD TVs, and information displays, or light-adjustable films, retardation 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.), coplanar switching (In-Plane Switching, IPS) type, Fringe Field Switching (Fringe Field Switching, FFS) type, Optically Compensated Bend (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. A liquid crystal display element can be manufactured by the method including the following steps 1-3, for example. In step 1, the board used differs depending on the desired operation mode. Step 2 and Step 3 are common in all operation modes.

(Step 1: Formation of Coating Film) First, the liquid crystal alignment agent is coated on the substrate, preferably by heating the coated surface, thereby forming a coating film on the substrate. As the substrate, for example, a transparent substrate including glass such as float glass and soda glass; polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly( Alicyclic olefin) and other plastics. As the transparent conductive film provided on one side of the substrate, 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 ) Indium tin oxide (Indium tin oxide, 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 or FFS 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 lithography, 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 carried out for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amide acid structure of the polymer. The calcination 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 thus formed film 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 coating film formed in the above step 1 is subjected to a treatment (alignment treatment) for imparting liquid crystal alignment ability. 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, the following treatment can be exemplified: a rubbing treatment in which the coating film is rubbed in a certain direction with a roller wrapped with a cloth containing fibers such as nylon (nylon), rayon (rayon), and cotton (cotton); A photo-alignment treatment in which a coating film formed on a substrate using a liquid crystal alignment agent is irradiated with light to impart liquid crystal alignment capability to the coating film, and the like. 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 subjected to alignment treatment (rubbing treatment, photo-alignment processing, etc.). A liquid crystal alignment agent suitable for a vertical alignment type liquid crystal display element may also be suitable for a polymer sustained alignment (PSA) type liquid crystal display element.

In the case where the liquid crystal alignment agent contains a polymer having a photoalignment group, it is preferable to form a liquid crystal alignment film by a photoalignment method. In this case, uniform liquid crystal alignment can be imparted to the photosensitive organic film while suppressing the generation of static electricity and dust, and it is also possible to precisely control the liquid crystal alignment direction, which is preferable. Light irradiation for photoalignment can be performed by methods such as a method of irradiating the coating film after the post-baking step, a method of irradiating the coating film after the pre-baking step and before the post-baking step, A method of irradiating the coating film during heating of the coating film in at least any one of the pre-baking step and the post-baking step. As the radiation irradiated to the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150 nm to 800 nm can be used. Ultraviolet rays including light having a wavelength of 200 nm to 400 nm are preferable. When the radiation is polarized light, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or may be combined. The irradiation direction in the case of non-polarized radiation is an oblique direction.

Examples of the light source used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, and excimer lasers. The dose of radiation exposure is preferably from 400 J/m ² to 50,000 J/m ² , more preferably from 1,000 J/m ² to 20,000 J/m ² . After being irradiated with light for imparting alignment ability, the use of water, organic solvents (for example, methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, etc. Ethyl lactate, etc.) or a mixture of these is cleaned, or the substrate is heated.

(Step 3: Construction of the Liquid Crystal Cell) Next, two substrates on which the liquid crystal alignment film was formed as described above were prepared, and liquid crystals were arranged between the two substrates facing each other to manufacture a liquid crystal cell. Examples of manufacturing a liquid crystal cell include (1) arranging two substrates facing each other through a gap (spacer) so that the liquid crystal alignment films face each other, bonding the peripheral parts of the two substrates together with 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 dropping the liquid crystal at several places on the surface of the liquid crystal alignment film, bonding another substrate so that the liquid crystal alignment film faces each other, and spreading the liquid crystal over the entire surface of the substrate (one drop filling , ODF) way) etc. Desirably, the manufactured liquid crystal cell is further heated to the temperature at which the liquid crystal used becomes an isotropic phase, and then slowly cooled to room temperature to eliminate 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, or 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 polarizing plates include polarizing films called "H films" in which polyvinyl alcohol is stretched and aligned on one side and iodine is absorbed on the other, between cellulose acetate protective films, or polarizing plates that include the H film itself. polarizer. In this way, a liquid crystal display element was obtained. [Example]

Hereinafter, the present invention will be further specifically described by way of examples, but the present invention is not limited to these examples.

The structures and abbreviations of the main compounds used in the following examples are as follows. (tetracarboxylic acid derivatives) TA-1: 2,3,5-tricarboxycyclopentylacetic dianhydride TA-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride TA-3: ( 1R,2R,3S,4S)-1,3-Dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride TA-4: Dimethylallyl (2r,4r)-2 ,4-bis(chlorocarbonyl)-2,4-dimethylcyclobutane-1,3-dicarboxylate TA-5: pyromellitic anhydride TA-6: 4,4'-oxydiphthalic acid Diformic anhydride TA-7: Propane-1,3-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) [Chem. 7]

(Diamine compound) DA-1: p-phenylenediamine DA-2: 2,2'-dimethylbenzidine DA-3: N,N'-bis(4-aminophenyl)-N,N'-Dimethylbiphenyl-4,4'-diamine DA-4: N,N'-bis(5-amino-2-pyridyl)-N,N'-dimethylethylenediamine DA-5 : 1,4-phenylene bis(4-aminobenzoate) DA-6: 4-aminophenyl(E)-3-(4-aminophenyl)-2-methacrylate DA-7: 1,5-bis(4-(2-(4-aminophenyl)ethyl)phenoxy)pentane [Chem. 8]

(Basic compounds) BA-1: 4-dimethylaminopyridine BA-2: 4-hydroxypyridine BA-3: diazabicycloundecene BA-4: 1,1,3,3-tetramethyl Base Guanidine BA-5: 1,5,7-Triazabicyclo[4.4.0]dec-5-ene BA-6: 1,8-bis(dimethylamino)naphthalene BB-1: Dimethyl Aniline BB-2: Pyridine BB-3: Imidazole BB-4: N,N-Diisopropylethylamine BB-5: Tetramethylammonium hydroxide [Chem. 9]

(solvent) NMP: N-methyl-2-pyrrolidone γBL: γ-butyrolactone BC: Butyl cellosolve

<Synthesis of Polymer> [Synthesis Example 1] Diamine (DA-2) and (DA-3) were dissolved in NMP at a molar ratio of 70:30, and 0.9 equivalent of tetracarboxylic acid derivative (TA -1), react at room temperature for 6 hours to obtain a 15% by mass solution of polyamide acid (PA-1). [Synthesis Example 2 to Synthesis Example 8] The types and molar ratios of the tetracarboxylic acid derivative and the diamine compound were respectively changed as described in the following Table 1, and were obtained in the same manner as in Synthesis Example 1, respectively. Polyamide acid (PA-2～PA-8). [Synthesis Example 9] The 15% by mass solution of polyamic acid (PA-4) obtained in Synthesis Example 4 was diluted to 10% by mass by NMP, and the amide 0.7 equivalents of 1-methylpiperidine and acetic anhydride were added, and heated and stirred at 60° C. for 3 hours. Concentration under reduced pressure and dilution with NMP were repeated for the obtained solution to obtain a 15% by mass solution of polyimide (PI-1). Determination of the ¹ H-NMR (nuclear magnetic resonance, NMR) spectrum (DMSO-d ⁶ , 400 MHz) of polyimide (PI-1), according to the aromatic proton (δ6.0 ppm ~ 9.0 ppm) and the main chain The ratio of amide protons (δ9.8 ppm to 10.3 ppm) and amide protons at the end of the acetyl group (δ9.6 ppm to 9.8 ppm) was used to calculate the amide imidization rate. As a result, the amide imidization rate was 70%. .

[Synthesis Example 10] Put tetracarboxylic acid derivative (TA-4) (8.11 g, 20.0 mmol), pyridine (3.80 g, 48.0 mmol), γBL 22 g, and NMP 11 g in a 50 mL three-necked flask equipped with a nitrogen gas introduction tube and a thermometer , and cooled to about 10°C to prepare an acyl chloride solution. Here, a diamine solution prepared by dissolving diamine (DA-1) (1.95 g, 18.0 mmol) in γBL 11 g beforehand was added, and reacted at 10° C. for 4 hours under a nitrogen stream. The obtained polymerization solution was diluted with 58 g of methanol, and slowly poured into a mixed solvent of water/isopropanol=1/1 (mass ratio) while stirring, and solidified. The precipitated solid was recovered, stirred and washed in water and isopropanol, and vacuum-dried at 60° C., thereby obtaining a white powder. The obtained powder was dissolved in γBL to obtain a 15% by mass solution of polyamide ester (PAE-1). [Synthesis Example 11] A polyorganosiloxane (SQ-1) having a cinnamate structure in a side chain was synthesized according to the method described in Synthesis Example S1 of paragraph [0104] of JP-A-2010-217868.

[Table 1]

Regarding the numerical values in Table 1, for the tetracarboxylic acid derivatives, it represents the use ratio (mole parts) of each compound relative to 100 mole parts of the total amount of the tetracarboxylic acid derivatives used in the synthesis, and for the diamine For the compounds, the usage ratio (parts by mole) of each compound is shown relative to 100 parts by mole of the total amount of diamine compounds used for synthesis.

[Example 1: Photoalignment FFS type liquid crystal display element] (1) Preparation of liquid crystal alignment agent Using polyamic acid (PA-1), polyimide (PI-1) and basic compound (BA-1) and diluting with NMP and BC, the solid content concentration is 3.5% by mass and the solvent composition ratio is obtained. Become a solution of NMP:BC=80:20 (mass ratio). The liquid crystal alignment agent (R-1) was prepared by filtering the solution through a filter with a pore size of 0.2 μm. Furthermore, the two polymers were prepared at a ratio of polyamide acid (PA-1): polyimide (PI-1) = 60:40 (mass ratio in terms of solid content), so that the relative The basic compound is contained in the ratio of 1.0 molar equivalent to the carboxylic acid group (-COOH) in the whole polymer.

(2) Formation of liquid crystal alignment film by photo-alignment method Apply the liquid crystal alignment agent (R-1) prepared in the above (1) to a film thickness of 0.1 μm using a spinner to sequentially build up layers on one side The surfaces of the glass substrate with the flat electrode, the insulating layer, and the comb-shaped electrode, and the facing glass substrate not provided with the electrode were dried on a hot plate at 80° C. for 1 minute to form a coating film. The surface of the coating film was irradiated with 2,000 J/m ² of ultraviolet light including a linearly polarized bright line of 254 nm from the normal direction of the substrate using a Hg-Xe lamp to perform photo-alignment treatment. The coating film subjected to the photo-alignment treatment was heat-treated for 40 minutes in an oven at 230° C. in which the cavity was replaced with nitrogen, thereby forming a liquid crystal alignment film.

(3) Manufacture of liquid crystal display elements For the pair of substrates having the liquid crystal alignment film prepared in (2), the liquid crystal injection port was left on the edge of the surface on which the liquid crystal alignment film was formed, and epoxy resin filled with alumina balls with a diameter of 5.5 μm was bonded to the substrate. After applying the agent by screen printing, the substrates were laminated and pressure-bonded so that the projection direction of the polarization axis to the substrate surface during light irradiation was antiparallel, and the adhesive was thermally cured at 150° C. for 1 hour. Next, a nematic liquid crystal (MLC-7028 manufactured by Merck) was filled between the pair of substrates from the liquid crystal injection port, and the liquid crystal injection port was sealed with an epoxy-based adhesive. Furthermore, in order to eliminate the flow alignment at the time of liquid crystal injection, after heating at 120 degreeC, it cooled slowly to room temperature. Next, a polarizing plate was bonded to the outer both surfaces of the board|substrate, and the FFS type liquid crystal display element was manufactured.

(4) Evaluation of liquid crystal alignment For the liquid crystal display element produced in (3) above, the abnormal domain (domain ) presence or absence. Regarding the evaluation, the case where no abnormal region was observed was regarded as "good", and the case where abnormal region was observed was regarded as "poor". As a result, it was evaluated as "good" in this Example.

(5) Evaluation of AC afterimage characteristics An FFS type liquid crystal cell was produced by performing the same operation as (3) above except that a polarizing plate was not bonded to both outer surfaces of the substrate. After driving this FFS type liquid crystal cell with an AC voltage of 10 V for 30 hours, the minimum relative value represented by the following formula (1) is measured using a device in which a polarizer and an analyzer are arranged between the light source and the light quantity detector. Transmittance (%). Minimum relative transmittance (%)=(β-B0)/(B100-B0)×100…(1) (In formula (1), B0 is blank and is the light transmission amount under crossed nicols. B100 is blank and is the light under parallel nicols The transmittance. β is the minimum light transmittance when the liquid crystal cell is sandwiched between the polarizer and the analyzer under crossed Nicols) The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal cell. In the FFS liquid crystal cell, the smaller the black level (minimum relative transmittance) in the dark state, the better the contrast. If the minimum relative transmittance is less than 0.2%, it is "excellent", if it is more than 0.2% and less than 0.5%, it is "good", if it is more than 0.5% and less than 1.0%, it is "good", and if it is 1.0 % or more is set as "bad". As a result, it was evaluated as "excellent" in this Example.

[Example 2 to Example 10, Comparative Example 1 to Comparative Example 6] In the above-mentioned Example 1, the polymer and basic compound contained in the liquid crystal alignment agent were changed as shown in the following Table 2, except that, the liquid crystal alignment agent was prepared in the same manner as in Example 1 and formed Liquid crystal alignment film, and FFS type liquid crystal display element and liquid crystal cell are produced and various evaluations are performed. The evaluation results are shown in Table 2 below.

[Example 11] In the above-mentioned Example 1, "(1) Preparation of liquid crystal alignment agent" and "(2) Formation of liquid crystal alignment film by photo-alignment method" are as follows (1a) and (2a) Except having generally changed, an FFS type liquid crystal display element and a liquid crystal cell were produced in the same manner as in Example 1, and various evaluations were performed. The evaluation results are shown in Table 2 below. (1a) Preparation of liquid crystal alignment agent Use polyamide acid (PA-1), polyamide acid (PA-4) and basic compound (BA-1) and dilute with NMP and BC to obtain solid content concentration 3.5% by mass and a solvent composition ratio were NMP:BC=80:20 (mass ratio) solution. The liquid crystal alignment agent (R-11) was prepared by filtering the solution through a filter with a pore size of 0.2 μm. Furthermore, the two polymers were formulated at a ratio of polyamic acid (PA-1): polyamic acid (PA-4) = 60:40 (mass ratio in terms of solid content), so that the relative The basic compound is contained in a ratio of 0.5 molar equivalents to the carboxylic acid groups in the whole polymer. (2a) Formation of liquid crystal alignment film by photo-alignment method Use a spinner to apply the liquid crystal alignment agent (R-11) prepared in (1a) on one side with a flat plate electrode, an insulating layer and a comb layered sequentially. The glass substrate of the tooth-shaped electrode and the opposite glass substrate without electrodes are heated for 1 minute by a heating plate at 80°C, and then placed in an oven at 230°C with nitrogen replacement in the chamber. Drying was carried out for 30 minutes to form a coating film with an average film thickness of 0.1 μm. The surface of the coating film was irradiated with 2,000 J/m ² of ultraviolet light including a linearly polarized bright line of 254 nm from the normal direction of the substrate using a Hg-Xe lamp to perform photo-alignment treatment. The coating film subjected to the photo-alignment treatment was heat-treated for 40 minutes in an oven at 230° C. in which the cavity was replaced with nitrogen, thereby forming a liquid crystal alignment film. [Example 12-Example 13, Comparative Example 7] In the above-mentioned Example 11, the polymer and the basic compound contained in the liquid crystal alignment agent were changed as shown in the following Table 2. In the same manner as in Example 11, a liquid crystal alignment agent was prepared and a liquid crystal alignment film was formed, and an FFS type liquid crystal display element and a liquid crystal cell were manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below.

[Example 14] In the above-mentioned Example 11, "(1) Preparation of liquid crystal alignment agent" was changed as in the following (1b), and the amount of ultraviolet irradiation was changed to 5,000 J/m ² , except that, An FFS type liquid crystal display element and a liquid crystal cell were manufactured in the same manner as in Example 11, and various evaluations were performed. The evaluation results are shown in Table 2 below. (1b) Preparation of liquid crystal alignment agent Use polyamide acid (PA-1), polyamide ester (PAE-1) and basic compound (BA-3) and dilute with NMP and BC to obtain solid content The concentration was 3.5% by mass, and the solvent composition ratio was a solution of NMP:BC=80:20 (mass ratio). The solution was filtered through a filter with a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R-14). Furthermore, the two polymers were prepared at a ratio of polyamic acid (PA-1): polyamic acid ester (PAE-1) = 90:10 (mass ratio in terms of solid content), so that the liquid crystal alignment agent contained The basic compound was contained in a ratio of 0.5 molar equivalents with respect to the carboxylic acid groups in the entire polymer.

[Example 15-Example 16] In the above-mentioned Example 11, the polymer and the basic compound contained in the liquid crystal alignment agent were changed as shown in the following Table 2, and the ultraviolet irradiation amount was changed to 5,000 J /m ² , except that a liquid crystal alignment agent was prepared in the same manner as in Example 11, a liquid crystal alignment film was formed, and an FFS type liquid crystal display element and a liquid crystal cell were manufactured and variously evaluated. The evaluation results are shown in Table 2 below.

[Example 17: Frictional alignment FFS type liquid crystal display element] In the above-mentioned Example 1, "(1) Preparation of liquid crystal alignment agent" and "(2) Formation of liquid crystal alignment film by photo-alignment method" were changed as following (1c) and (2c), except Except for this, in the same manner as in Example 1, an FFS type liquid crystal display element and a liquid crystal cell were produced and various evaluations were performed. The evaluation results are shown in Table 2 below. (1c) Preparation of liquid crystal alignment agent Using polyamic acid (PA-1), polyamic acid (PA-8) and basic compound (BA-3) and diluting with NMP and BC to obtain a solid content concentration of 3.5% by mass and a solvent composition ratio Become a solution of NMP:BC=80:20 (mass ratio). The liquid crystal alignment agent (R-17) was prepared by filtering the solution through a filter with a pore size of 0.2 μm. Furthermore, the two polymers were formulated at a ratio of polyamic acid (PA-1): polyamic acid (PA-8) = 60:40 (mass ratio in terms of solid content), so that the relative The basic compound is contained in a ratio of 0.5 molar equivalents to the carboxylic acid groups in the whole polymer. (2c) Formation of liquid crystal alignment film by rubbing method Use a spinner to apply the liquid crystal alignment agent (R-17) prepared in (1c) to the glass substrate on which a plate electrode, an insulating layer, and a comb-shaped electrode are sequentially laminated on one side, and to the opposite side where no electrode is provided. Each surface of the glass substrate was dried with an 80° C. hot plate for 1 minute, and then dried for 30 minutes in a 230° C. oven in which the chamber was replaced with nitrogen to form a coating film with an average film thickness of 0.1 μm. Using a rubbing machine having a roller wrapped with a nylon cloth, the surface of the coating film was rubbed at a roller rotation speed of 1000 rpm, a table moving speed of 25 mm/sec, and a bristle penetration length of 0.4 mm. The coating film subjected to the rubbing alignment treatment was ultrasonically cleaned in ultrapure water for 1 minute, and then dried in an oven at 100° C. for 10 minutes to form a liquid crystal alignment film.

[Example 18] In the above-mentioned Example 1, "(1) Preparation of liquid crystal alignment agent" and "(2) Formation of liquid crystal alignment film by photo-alignment method" are as follows (1d) and (2d) Except having generally changed, an FFS type liquid crystal display element and a liquid crystal cell were produced in the same manner as in Example 1, and various evaluations were performed. The evaluation results are shown in Table 2 below. (1d) Preparation of liquid crystal alignment agent Use polyamic acid (PA-1), polyorganosiloxane (SQ-1) and basic compound (BA-3) and dilute with NMP and BC to obtain solid content The concentration was 3.5% by mass, and the solvent composition ratio was a solution of NMP:BC=80:20 (mass ratio). The liquid crystal alignment agent (R-18) was prepared by filtering the solution through a filter with a pore size of 0.2 μm. Furthermore, the two polymers were formulated at a ratio of polyamic acid (PA-1): polyorganosiloxane (SQ-1) = 90:10 (mass ratio in terms of solid content), so that the liquid crystal alignment agent contained The basic compound was contained in a ratio of 0.5 molar equivalents with respect to the carboxylic acid groups in the entire polymer. (2d) Formation of liquid crystal alignment film by photo-alignment method Use a spinner to apply the liquid crystal alignment agent (R-18) prepared in (1d) on one side where a flat plate electrode, an insulating layer and a comb layer are sequentially laminated. The glass substrate of the tooth-shaped electrode and the opposite glass substrate without electrodes are heated for 1 minute by a heating plate at 80°C, and then placed in an oven at 200°C with nitrogen replacement in the chamber. Drying was carried out for 30 minutes to form a coating film with an average film thickness of 0.1 μm. A Hg-Xe lamp was used to irradiate the surface of the coating film with 300 J/ ^m2 of ultraviolet light including a bright line of 313 nm through linear polarization from the normal direction of the substrate to perform photo-alignment treatment, thereby forming a liquid crystal alignment film.

[Table 2]

In Examples 1 to 6 and Comparative Examples 1 to 6, (PA-1) was used as the first polymer and (PI-1) was used as the second polymer, and the types of basic compounds were changed and evaluated. In Examples 1 to 6, compared with Comparative Example 1, the solubility of the polymer was improved, even if the liquid crystal alignment agent absorbed moisture, the polymer was not easily precipitated, and the coatability to the substrate was good. Furthermore, in Examples 1 to 6, the liquid crystal alignment and AC afterimage characteristics were all "good", "possible", or "excellent", and in Comparative Examples 1 to 6, any one was " bad". It is considered that by adding the compound (A) to the liquid crystal alignment agent, a salt is formed with a polymer having an acidic functional group, and the polarity of the polymer is greatly changed. In addition, in Examples 1 to 6, although the mechanism for the improvement of liquid crystal alignment and AC afterimage characteristics is not certain, it is considered that by using the compound (A) as the basic compound, the first polymer tends to exist preferentially in the As a result of aligning the lower layer of the film, the polymer having a photoalignment group (second polymer) undergoes layer separation on the upper layer of the alignment film, thereby improving the above-mentioned characteristics. On the other hand, in Comparative Example 1 to Comparative Example 6, the basicity, polarity, non-nucleophilicity, volatility, etc. of the basic compound were considered to be unsuitable, and desired characteristics were not exhibited.

In Example 7 and Example 8, the type of the first polymer was changed and evaluated. As a result, the liquid crystal alignment and AC afterimage characteristics were "good" and "excellent", respectively. In Example 9 and Example 10, the addition amount of the basic compound was changed and evaluated, and as a result, both the liquid crystal alignment property and the AC afterimage characteristic were "good" or "possible". In Examples 11 to 13 and Comparative Example 7, the types of the second polymer and the basic compound were changed and evaluated. The liquid crystal alignment properties were all "good", while the AC afterimage characteristics were "excellent" or "possible" in Examples 11 to 13, but were "poor" in Comparative Example 7. In Examples 14 to 18, the type of the second polymer and the alignment treatment method were changed and evaluated. As a result, the liquid crystal alignment was "good" and the AC afterimage characteristic was "excellent" or "acceptable".

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Claims (8)

A liquid crystal alignment agent, which contains: the first polymer; the second polymer; and compound (A), and the first polymer is polyamic acid, and the second polymer is the same as the first polymer different polymers, the compound (A) has a partial structure selected from the following formula (1-1), the partial structure represented by the following formula (1-2), the following formula (1- 3) At least one nitrogen-containing structure in the group consisting of the partial structure represented by the following formula (1-4) and the partial structure represented by the following formula (1-4) (wherein, it will include the following formula (1-2) Partial structure and at least any nitrogen-containing aromatic heterocycle in the partial structure represented by the following formula (1-3)), and a compound that does not have at least one of an acidic functional group and an electron-withdrawing group (wherein, when the compound (A) has a partial structure represented by the following formula (1-1), the second polymer has a nitrogen-containing aromatic heterocycle),

(In formula (1-1), regarding R ¹ and R ² , R ¹ is a monovalent group bonded to the pyridine ring through a nitrogen atom or an oxygen atom, and R ² is a monovalent organic group, or R ¹ and R ² represents a ring structure in which R ¹ (wherein R ¹ is bonded to the pyridine ring through a nitrogen atom or an oxygen atom) and R ² are combined with each other and the carbon atoms to which R ¹ and R ² are bonded respectively; m is an integer from 1 to 3, n is an integer from 0 to 2, m+n≦3; when m is 2 or 3, multiple R ¹ can be the same or different, and when n is 2, Multiple R ² can be the same or different; in formula (1-4), R ³ is an alkyl group with 1 to 5 carbons; r is an integer of 0 to 3; when r is 2 or 3, multiple R ³ may be the same or different; "*" in formula (1-1)~formula (1-4) represents a bonding bond). The liquid crystal alignment agent as described in item 1 of the scope of the patent application, wherein the compound (A) is selected from the compound represented by the following formula (2-1), the compound represented by the following formula (2-2), At least one compound in the group consisting of a compound represented by the following formula (2-3) and a compound represented by the following formula (2-4) (wherein, the compound represented by the following formula (2-2) Except for the case where the compound is a nitrogen-containing heterocyclic compound and the compound represented by the following formula (2-3) is a nitrogen-containing heterocyclic compound),

(In formula (2-1), R ¹¹ is "-NR ²⁶ R ²⁷ " or "-OR ²⁸ ", R ¹² is a monovalent organic group with 1 to 10 carbons; R ²⁶ , R ²⁷ and R ²⁸ are independently Ground is a hydrogen atom or a monovalent organic group with a carbon number of 1 to 10; wherein, R ²⁶ and R ²⁷ can also be combined with each other and form a ring structure together with the nitrogen atom to which R ²⁶ and R ²⁷ are bonded; the formula (2-2 ), R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom or a monovalent organic group with 1 to 10 carbons, and two or more of R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are organic Groups can also be bonded to form a ring structure (wherein nitrogen-containing aromatic heterocycles are excluded); in formula (2-3), R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ are independently a hydrogen atom, an amino group or a monovalent organic group with 1 to 10 carbons, R ²¹ is a hydrogen atom or a monovalent organic group with 1 to 10 carbons, two or more of R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ are organic Groups can also be bonded to form a ring structure (wherein nitrogen-containing aromatic heterocycles are excluded); in formula (2-4), R ²² , R ²³ , R ²⁴ and R ²⁵ are independently hydrogen atoms or carbon numbers A monovalent organic group of 1 to 10; wherein, R ¹¹ to R ²⁵ do not have at least one of an acidic functional group and an electron-withdrawing group; m and n have the same meaning as the formula (1-1), and R ³ and r have the same meaning as the formula (1-4)). The liquid crystal alignment agent as described in item 1 or item 2 of the scope of the patent application, wherein the second polymer is selected from polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and at least one of the group consisting of a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond. The liquid crystal alignment agent as described in item 1 or item 2 of the patent application, wherein the second polymer has a photoalignment group. A method for producing a liquid crystal alignment agent, comprising: a step of mixing a first polymer, a second polymer, and a compound (A), and the first polymer is polyamic acid, and the second polymer It is a polymer different from the first polymer, and the compound (A) has a partial structure selected from the partial structure represented by the following formula (1-1) and the partial structure represented by the following formula (1-2) , the partial structure represented by the following formula (1-3), and at least one nitrogen-containing structure in the group formed by the partial structure represented by the following formula (1-4) (wherein, the following formula ( 1-2) and at least any nitrogen-containing aromatic heterocycle in the partial structure represented by the following formula (1-3), and does not have an acidic functional group or an electron-withdrawing group At least one of the compounds (wherein, when the compound (A) has a partial structure represented by the following formula (1-1), the second polymer has a nitrogen-containing aromatic heterocycle),

(In formula (1-1), regarding R ¹ and R ² , R ¹ is a monovalent group bonded to the pyridine ring through a nitrogen atom or an oxygen atom, and R ² is a monovalent organic group, or R ¹ and R ² represents a ring structure in which R ¹ (wherein R ¹ is bonded to the pyridine ring through a nitrogen atom or an oxygen atom) and R ² are combined with each other and the carbon atoms to which R ¹ and R ² are bonded respectively; m is an integer from 1 to 3, n is an integer from 0 to 2, m+n≦3; when m is 2 or 3, multiple R ¹ can be the same or different, and when n is 2, Multiple R ² can be the same or different; in formula (1-4), R ³ is an alkyl group with 1 to 5 carbons; r is an integer of 0 to 3; when r is 2 or 3, multiple R ³ may be the same or different; "*" in formula (1-1)~formula (1-4) represents a bonding bond). A method for manufacturing a liquid crystal alignment film, which uses the liquid crystal alignment agent described in any one of the first to fourth items of the scope of the patent application to form a coating film on a substrate, and irradiates the coating film to give liquid crystal alignment ability. 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 as described in item 7 of the patent application.