JP6962440B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal element - Google Patents

Description

Cross-reference of related applications

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

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

Liquid crystal elements are used in various applications such as display devices such as televisions, personal computers, and smartphones. These liquid crystal elements include a liquid crystal alignment film having a function of orienting liquid crystal molecules in a certain direction. The liquid crystal alignment film is generally formed on the substrate by applying a liquid crystal alignment agent in which the polymer component is dissolved in an organic solvent onto the substrate and preferably heating the substrate. As the polymer component of the liquid crystal alignment agent, polyamic acid and soluble polyimide are widely used because they are excellent in mechanical strength, liquid crystal orientation, and affinity with liquid crystal. Further, as the solvent component of the liquid crystal alignment agent, a solvent having high solubility in a polymer such as polyamic acid or soluble polyimide (for example, a good solvent such as N-methyl-2-pyrrolidone or γ-butyrolactone) and wetness to the substrate are used. A mixed solvent with a solvent having high spreadability (for example, a poor solvent such as butyl cellosolve) is generally used (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2017-198975 Japanese Unexamined Patent Publication No. 2016-206645

As for LCD TVs, in recent years, there have been standards for display devices with an increased number of pixels, such as 4K (for example, 3840 pixels x 2160 pixels) and 8K (for example, 7680 pixels x 4320 pixels), in order to obtain a sense of realism by further improving the display quality. It is made. As the number of pixels in the display device increases and the pixel size decreases, the pixel electrodes have a finer structure, and the surface on which the pixel electrodes are formed has a higher uneven density per unit area. In this case, when the liquid crystal alignment agent is applied to the forming surface of the pixel electrode to form the alignment film, the liquid crystal alignment agent is difficult to wet and spread with respect to the fine uneven structure of the pixel electrode, and sufficient coatability to the substrate is ensured. There is concern that it cannot be done. In order to obtain good coatability even when the liquid crystal alignment agent is applied to a fine uneven structure, it is necessary to use a liquid crystal alignment agent having high wettability and spreadability on a substrate.

Furthermore, in recent years, large-screen liquid crystal panels have become widespread, and larger lines have come into operation than before, and the size of substrates has been increasing. The merits of increasing the size of the substrate are that it is possible to reduce the process time and cost because multiple panels can be taken from one substrate, and that it is possible to cope with the increase in the size of the liquid crystal panel itself. Be done. On the other hand, when a liquid crystal alignment film is formed on a large substrate, temperature unevenness is more likely to occur during post-baking than in the past, and the pretilt angle of the liquid crystal alignment film varies due to this temperature unevenness, resulting in display quality. There is concern that it will lead to a decline.

Further, as a liquid crystal panel, a touch panel type small display panel represented by a smartphone or a tablet PC is being developed. Here, in the touch panel type display panel, an attempt is made to narrow the frame in order to make the movable area of the touch panel wider and to make the liquid crystal panel smaller. Further, as the frame of the liquid crystal panel is narrowed, display unevenness due to the liquid crystal alignment film may be visually recognized around the sealant due to aging or the like. In order to achieve high definition and long life of the liquid crystal panel, a liquid crystal element is required in which display unevenness around the sealant is hard to be visually recognized for a long period of time (high resistance to bezel unevenness).

Furthermore, in a liquid crystal display device, if the residual charge (residual DC) in the liquid crystal alignment film is large, the influence of the previously displayed image remains after switching the image, so-called afterimage (this is also called DC afterimage). It causes the occurrence of.). Further, when the liquid crystal display device is operated for a long time, if the direction of the initial orientation deviates from the direction from the beginning of the manufacture of the liquid crystal display device, a burn-in called an AC afterimage may occur. In order to secure the display quality, a liquid crystal display device in which such DC afterimages and AC afterimages are reduced as much as possible is required.

The present disclosure has been made in view of the above problems, has good coatability for fine uneven structures, is less susceptible to temperature unevenness during heating during film formation, has less display unevenness around the sealant, and has an afterimage. One object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a liquid crystal element having good characteristics.

In order to solve the above problems, we have diligently studied and found that the above problems can be solved by containing a compound having a structure in which a specific group (partial structure) is bonded to a benzene ring in a liquid crystal alignment agent. Specifically, the following means were adopted.

（式（１）中、Ｒ^１は、炭素数１〜４のアルキル基、−ＣＯ−ＣＨ_３、又は−Ｒ^４−ＯＨ（ただし、Ｒ^４は炭素数１〜４のアルカンジイル基）である。Ｒ^２は、水素原子又は炭素数１〜４のアルキル基である。ｎは１又は２である。ただし、ｎが２の場合、Ｒ^２は水素原子である。ｎが２の場合、式（１）中の複数のＲ^１は、互いに同じでも異なっていてもよい。式（２）中、Ｒ^３は、炭素数１〜３のアルカンジイル基である。）
＜２＞ 液晶配向膜を備える液晶素子の製造方法であって、上記＜１＞の液晶配向剤を用いて液晶配向膜を形成する、液晶素子の製造方法。
＜３＞ 上記＜１＞の液晶配向剤を用いて形成された液晶配向膜。
＜４＞ 上記＜３＞の液晶配向膜を備える液晶素子。<1> A liquid crystal display containing a polymer component and at least one compound [A] selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2). Aligner.

(In the formula (1), R ¹ is an alkyl group having 1 to 4 carbon atoms, -CO-CH ₃ , or -R ^4- OH (where R ⁴ is an alkanediyl group having 1 to 4 carbon atoms). R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N is 1 or 2. However, when n is 2, R ² is a hydrogen atom. When n is 2, the formula is (1) a plurality of ^{R 1} in during may be the same or different from each other. equation (2), ^{R 3} is an alkanediyl group having 1 to 3 carbon atoms.)
<2> A method for manufacturing a liquid crystal element including a liquid crystal alignment film, wherein the liquid crystal alignment film is formed by using the liquid crystal alignment agent of <1> above.
<3> A liquid crystal alignment film formed by using the liquid crystal alignment agent of <1> above.
<4> A liquid crystal element provided with the liquid crystal alignment film of <3> above.

The liquid crystal alignment agent of the present disclosure has good wettability and spreadability even when applied to a substrate surface having a fine uneven structure, and can uniformly form a liquid crystal alignment film on the substrate surface. Further, the liquid crystal alignment agent of the present disclosure is not easily affected by temperature unevenness during heating at the time of film formation, and thus a liquid crystal alignment film in which characteristic variation due to temperature unevenness is suppressed can be obtained. Further, according to the liquid crystal alignment agent of the present disclosure, it is possible to obtain a liquid crystal element having less display unevenness around the sealant (good bezel unevenness resistance) and excellent afterimage characteristics.

FIG. 1 is a diagram showing a schematic configuration of an ITO electrode substrate for evaluation. (A) is a plan view, and (b) is a partially enlarged cross-sectional view.

Hereinafter, each component contained in the liquid crystal alignment agent of the present disclosure, and other components optionally blended will be described. The liquid crystal alignment agent is a liquid polymer composition containing a polymer component and a solvent component, and the polymer component is dissolved in the solvent component.

≪Polymer component≫
The main skeleton of the polymer component contained in the liquid crystal aligning agent is not particularly limited, but for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, polyamideimide, polybenzoxazole precursor, polybenzo Examples thereof include a main skeleton such as an oxazole, a cellulose derivative, a polyacetal, and a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond (hereinafter, also referred to as “polymer (Q)”). From the viewpoint of ensuring sufficient performance of the liquid crystal element, the polymer component may be at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide and polymer (Q). It is particularly preferable that it is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide.

<Polyamic acid>
The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound.
(Tetracarboxylic dianhydride)
Examples of the tetracarboxylic dianhydride used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. .. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
As the alicyclic tetracarboxylic acid dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic hydride, 5- (2,5-dioxo tetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1 , 3-Dione, 5- (2,5-dioxo tetrahydrofuran-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'-(Anhydride-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 acid dianhydride, cyclohexanetetracarboxylic acid dianhydride, etc .; as aromatic tetracarboxylic acid dianhydride, for example, pyromellitic acid dianhydride, 4,4'-(hexafluoroisopropylidene). Diphthalic anhydride, ethylene glycol bisanhydrotrimate, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, etc .; The tetracarboxylic dianhydride described in JP-A-2010-97188 can be used. The tetracarboxylic dianhydride may be used alone or in combination of two or more.

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、＊−ＣＯＯ−又は＊−ＯＣＯ−（ただし、「＊」はＸ^Ｉとの結合手を示す。）であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物、桂皮酸構造を側鎖に有するジアミンなどの側鎖型ジアミン：(Diamine compound)
Examples of the diamine compound used for the synthesis of the polyamic acid include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and a diaminoorganosiloxane. Specific examples of these diamines include, for example, metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like as aliphatic diamines; for example, 1,4 as alicyclic diamines. -Diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), etc .;
As aromatic diamines, for example, dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, pentadecanoxy-2,5-diamino Benzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2, 4-Diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestan, 3,6- Bis (4-aminophenoxy) cholesterol, 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-cholestane-3-yl, the following formula (E-1)

(In the formula (E-1), X ^I and X ^II are independently single-bonded, -O-, * -COO- or * -OCO- (where "*" is a bond with ^{X I.} shown.), and, ^{R I} is an alkanediyl group having 1 to 3 carbon ^{atoms, R II} is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is 0 It is an integer of ~ 2, c is an integer of 1 to 20, d is 0 or 1. However, a and b cannot be 0 at the same time.)
Side chain diamines such as compounds represented by, diamines having a cinnamic acid structure in the side chain:

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, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,10-bis (4-aminophenoxy) Decane, 1,2-bis (4-aminophenyl) ethane, 1,5-bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane, 1,4-bis (4-amino) Phenylsulfanyl) butane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, N, N-bis (4-aminophenyl) methylamine, 2,6-diaminopyridine, 1,4-bis- (4) -Aminophenyl) -piperazin, 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 (piperidin-1,4-diyl)] dianiline, 4,4'-diaminobenzanilide, 4,4'-diaminostillbenzene, 4,4'-diaminodiphenylamine, 1,3-bis ( 4-Aminophenethyl) urea, 1,3-bis (4-aminobenzyl) urea, 1,4-bis (4-aminophenyl) -piperazin, N- (4-aminophenylethyl) -N-methylamine, N , N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine and other main chain diamines; as diaminoorganosiloxane, for example, 1,3-bis (3-aminopropyl) -tetramethyldi Siloxane etc .; In addition to the above, the diamine described in JP-A-2010-97188 can be used.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine compound, if necessary, with a molecular weight modifier. The ratio of the tetracarboxylic acid dianhydride used in the polyamic acid synthesis reaction to the diamine compound is 0.2 for the acid anhydride group of the tetracarboxylic acid dianhydride with respect to 1 equivalent of the amino group of the diamine compound. A ratio of about 2 equivalents is preferable. Examples of the molecular weight adjusting agent include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenylisocyanate and naphthylisocyanate. Can be mentioned. The ratio of the molecular weight adjusting agent used is preferably 20 parts by mass or less with respect to 100 parts by mass in total of the tetracarboxylic dianhydride and the diamine compound used.

The polyamic acid synthesis reaction 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 to 24 hours.
Examples of the organic solvent used in the reaction include aprotonic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. And one or more selected from the group consisting of halogenated phenol can be used as a solvent, or a mixture of one or more of these with another organic solvent (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.) can be used. preferable. The amount of the organic solvent used (a) shall be such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass with respect to the total amount (a + b) of the reaction solution. Is preferable. The reaction solution obtained by dissolving the polyamic acid may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamic acid contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent.

<Polyamic acid ester>
The polyamic acid ester is, for example, [I] a method of reacting the polyamic acid obtained by the above synthetic reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine compound, and [III] a tetracarboxylic. It can be obtained by a method of reacting an acid diester dihalide with a diamine compound, or the like. The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partial esterified product in which the amic acid structure and the amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamic acid ester contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent. good.

<Polyimide>
The polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize it. The polyimide may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure possessed by the polyamic acid that is the precursor thereof, or by dehydrating and ring-closing only a part of the amic acid structure, and the amic acid structure and the imide. It may be a partially imidized product in which a ring structure coexists. The imidization ratio of polyimide is preferably 20 to 99%, more preferably 30 to 90%. This imidization ratio is expressed as a percentage of the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid is preferably carried out by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating as necessary. In this method, as the dehydrating agent, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, colidin, lutidine, and triethylamine can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 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 organic solvents exemplified as those used in the synthesis of polyamic acids. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C. The reaction time is preferably 1.0 to 120 hours. The reaction solution containing the polyimide may be used as it is for the preparation of the liquid crystal alignment agent, or the polyimide may be isolated and then used for the preparation of the liquid crystal alignment agent. Polyimide can also be obtained by imidization of polyamic acid esters.

<Polyamide>
Polyamide can be obtained by a method of reacting a dicarboxylic acid with a diamine compound or the like. The dicarboxylic acid is preferably acid chlorided with an appropriate chlorinating agent such as thionyl chloride and then subjected to a reaction with a diamine compound.

The dicarboxylic acid used for the synthesis of polyamide is not particularly limited, and for example, an aliphatic dicarboxylic acid such as oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, and fumaric acid; cyclobutane. Alicyclic dicarboxylic acids such as dicarboxylic acid, 1-cyclobutenedicarboxylic acid, cyclohexanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 2,5-dimethylterephthalic acid, 4-carboxycatephotic acid, Aromatic dicarboxylic acids such as 3,3'-[4,4'-(methylenedi-p-phenylene)] dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)] dibutyric acid ; Etc. can be mentioned. Examples of the diamine compound used for the synthesis include the diamine compound exemplified in the description of the polyamic acid. One type of each of the dicarboxylic acid and the diamine compound may be used alone, or two or more types may be used in combination.

The reaction of the dicarboxylic acid with the diamine compound is preferably carried out in the presence of a base in an organic solvent. At this time, the ratio of the dicarboxylic acid to the diamine compound is preferably 0.2 to 2 equivalents of the carboxyl group of the dicarboxylic acid with respect to 1 equivalent of the amino group of the diamine compound. The reaction temperature is preferably 0 ° C. to 200 ° C., and the reaction time is preferably 0.5 to 48 hours. As the organic solvent, for example, tetrahydrofuran, dioxane, toluene, chloroform, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and the like can be preferably used. As the base, for example, tertiary amines such as pyridine, triethylamine, N-ethyl-N, and N-diisopropylamine can be preferably used. The ratio of the base used is preferably 2 to 4 mol with respect to 1 mol of the diamine compound. The solution obtained by the above reaction may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamide contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent.

<Polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond (polymer (Q))>
Examples of the monomer having a polymerizable unsaturated bond include a compound having a (meth) acryloyl group, a vinyl group, a styryl group, a maleimide group and the like. Specific examples of such compounds include unsaturated carboxylic acids such as (meth) acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, and vinyl benzoic acid: alkyl (meth) acrylic acid, cycloalkyl (meth) acrylic acid. , (Meta) benzyl acrylate, (meth) -2-ethylhexyl acrylate, (meth) trimethoxysilylpropyl acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylate Unsaturated carboxylic acid esters such as 3,4-epoxycyclohexylmethyl, (meth) acrylic acid 3,4-epoxybutyl, 4-hydroxybutylglycidyl ether acrylate: unsaturated polyvalent carboxylic acid anhydrides such as maleic anhydride: (Meta) acrylic compounds such as; aromatic vinyl compounds such as styrene, methylstyrene and divinylbenzene; conjugated diene compounds such as 1,3-butadiene, 2-methyl-1,3-butadiene; N-methylmaleimide, N. -Maleimide group-containing compounds such as cyclohexyl maleimide and N-phenyl maleimide; and the like. As the monomer having a polymerizable unsaturated bond, one type can be used alone or two or more types can be used in combination. As used herein, "(meth) acrylic" means to include "acrylic" and "methacryl".

The polymer (Q) can be obtained by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. Examples of the polymerization initiator used include 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), and 2,2'-azobis (4-methoxy-2). , 4-Dimethylvaleronitrile) and other azo compounds are preferred. The ratio of the polymerization initiator used is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of all the monomers used in the 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, and diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate and the like are preferable. The reaction temperature is preferably 30 ° C. to 120 ° C., and the reaction time is preferably 1 to 36 hours. The amount (a) of the organic solvent used should be such that the total amount (b) of the monomers used in the reaction is 0.1 to 60% by mass with respect to the total amount (a + b) of the reaction solution. Is preferable. The polymer solution obtained by the above reaction may be used as it is for the preparation of the liquid crystal alignment agent, or the polymer (Q) contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent.

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

The polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polymer 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. 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. The polymer used for preparing the liquid crystal alignment agent may be only one type or a combination of two or more types.

≪Compound [A] ≫
The liquid crystal alignment agent of the present disclosure contains at least one compound [A] selected from the group consisting of the compound represented by the above formula (1) and the compound represented by the above formula (2) together with the polymer component. .. Compound [A] has the property that the solubility of the polymer component in a solvent can be improved and the surface tension is moderately low. By using such compound [A] as a component of the liquid crystal alignment agent, good coatability having a fine uneven structure, suppression of characteristic variation due to temperature unevenness during heating at the time of film formation, suppression of characteristic variation due to temperature unevenness, and peripheral sealant The effects of reducing display unevenness (improving bezel unevenness resistance) and reducing afterimages can be obtained in a well-balanced manner.

In the above formula (1), ^{the alkyl groups having 1 to 4 carbon atoms of R 1} and R ² may be linear or branched, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl. Groups, isobutyl groups, sec-butyl groups, tert-butyl groups and the like can be mentioned. Of these, ^{the alkyl groups having 1 to 4 carbon atoms of R 1} and R ² are preferably linear, and more preferably a methyl group or an ethyl group. The ^{alkanediyl having 1 to 4} carbon atoms of R4 may be linear or branched, for example, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1. , 4-Diyl, butane-1,2-Diyl group and the like. R ⁴ is a methylene group or an ethylene group is preferred. R ¹ is preferably a methyl group, an ethyl group or -CO-CH ₃ in that the resistance to bezel unevenness can be improved.

The compound represented by the above formula (1) has n = 2 or n = 1 and R ² is an alkyl group having 1 to 4 carbon atoms in that the bezel unevenness resistance can be improved. Is preferable. In this case, it is more preferable that the two groups bonded to the benzene ring have the other group at the ortho-position or the meta-position with respect to one group. Among these, the compound represented by the above formula (1) preferably has n = 2, n = 2, and R ¹ has a methyl group, an ethyl group, or -CO-CH _3. More preferably, one group of the two "-OR ¹ " bonded to the benzene ring is in the ortho or meta position with respect to the other group.
In the above formula (2), R ³ is preferably a methylene group or an ethylene group. According to the compound represented by the above formula (2), the effect of improving the coatability on a fine uneven structure can be enhanced, which is preferable.

Compound [A] has a melting point of 25 ° C. or lower and a boiling point of 150 ° C. at 1 atm in that the coating property on a substrate having a fine uneven structure and the effect of improving bezel unevenness resistance can be suitably obtained. The above is preferable. The boiling point of compound [A] at 1 atm is preferably 160 ° C. or higher, more preferably 165 ° C. or higher, and even more preferably 170 ° C. or higher. The boiling point is more preferably 250 ° C. or lower, still more preferably 245 ° C. or lower. The melting point of compound [A] at 1 atm is preferably 20 ° C. or lower, more preferably 15 ° C. or lower, and even more preferably 10 ° C. or lower. When the compound [A] is a compound that is liquid at room temperature, the compound [A] is used as at least a part of the polymerization solvent when the polymer is polymerized, and the obtained polymer solution is used as it is to prepare a liquid crystal alignment agent. May be offered to.

As a specific example of the compound [A], as the compound represented by the above formula (1), for example, a compound represented by each of the following formulas (1-1) to (1-23); Examples of the compound represented by 2) include compounds represented by the following formulas (2-1) and (2-2). Of these, the following equations (1-1) to (1-5), equations (1-7) to (1-11), equations (1-13), equations (1-15), equations (1) -17) ~ At least one selected from the group consisting of formula (1-20), formula (1-22), formula (2-1) and formula (2-2) is more preferable. As the compound [A], one type may be used alone, or two or more types may be used in combination.

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

≪Other ingredients≫
The liquid crystal alignment agent contains a polymer component and compound [A], but if necessary, contains a component different from the polymer component and compound [A] (hereinafter, also referred to as “other component”). May be.

<Solvent [B]>
The liquid crystal aligning agent is composed of a group consisting of an alcohol solvent, a chain ester solvent, an ether solvent, and a ketone solvent together with the polymer component and the compound [A] for the purpose of improving the afterimage characteristics of the liquid crystal element. It may further contain at least one selected solvent (hereinafter, also referred to as “solvent [B]”).

Specific examples of the solvent [B] include, as alcohol-based solvents, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, 3 −methoxy-3-methylbutanol, benzyl alcohol, etc .; as chain ester solvents, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate, etc. Diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc.;
Examples of ether-based solvents include diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, and ethylene glycol ethyl ether. Acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA) , 3-methoxy-1-butanol, tetrahydrofuran, diisopentyl ether, etc .; as ketone solvents, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cycloheptanone, cyclopentanone, 3-methylcyclohexanone, 4-methyl Cyclohexanone, diisobutylketone and the like can be mentioned respectively.

As the solvent [B], at least one selected from the group consisting of an ether solvent and a ketone solvent is preferable, and an ether solvent having 8 or less carbon atoms and an ether solvent having 8 or less carbon atoms are preferable because the effect of improving the coatability can be further enhanced. At least one selected from the group consisting of cyclic ketone solvents is more preferable. Specifically, the solvent [B] is ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl. One selected from the group consisting of ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 3-methoxy-1-butanol and cyclopentanone is particularly preferable. As the solvent [B], one type can be used alone or two or more types can be used in combination.

The liquid crystal alignment agent may further contain a solvent different from the solvent [B] (hereinafter, also referred to as “another solvent”) as another component. Examples of other solvents include aprotonic polar solvents, phenols, halogenated hydrocarbon solvents, hydrocarbon solvents and the like. Specific examples of other solvents include aprotic polar solvents such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, gamma butyrolactone, and propylene carbonate. , 3-Butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-Hexyloxy-N, N-dimethylpropanamide, Isopropoxy-N-isopropyl-propionamide, n- Butoxy-N-isopropyl-propionamide and the like; as phenols such as phenol, m-cresol, xylenol and the like; as halogenated hydrocarbon solvents such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, etc. Trichloroethane, chlorobenzene and the like; examples of the hydrocarbon solvent include hexane, heptane, octane, benzene, toluene, xylene and the like. As other solvents, one type can be used alone or two or more types can be used in combination.

The content ratio of the compound [A] is preferably 10% by mass or more with respect to the total amount of the compound [A] and the solvent [B] contained in the liquid crystal alignment agent. When it is set to 10% by mass or more, it is preferable in that effects such as coatability of the liquid crystal alignment agent, resistance to bezel unevenness, suppression of characteristic variation due to temperature unevenness during film formation, and reduction of afterimage can be sufficiently obtained. .. The content ratio of the compound [A] is more preferably 15% by mass or more with respect to the total amount of the compound [A] and the solvent [B] in that the wettability and spreadability of the liquid crystal aligning agent and the resistance to bezel unevenness can be improved. Yes, more preferably 20% by mass or more. The content ratio of the compound [A] is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass, based on the total amount of the compound [A] and the solvent [B]. % Or less.
When the liquid crystal aligning agent contains the solvent [B], the content ratio of the solvent [B] is preferably 5% by mass with respect to the total amount of the compound [A] and the solvent [B] contained in the liquid crystal aligning agent. The above is more preferably 20% by mass or more. The content ratio of the solvent [B] is preferably 90% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass, based on the total amount of the compound [A] and the solvent [B]. % Or less.
The content ratio of the other solvent is preferably 5% by mass or less, and more preferably 3% by mass or less, based on the total amount of the compound [A] and the solvent [B] contained in the liquid crystal alignment agent. It is preferably 1% by mass or less, more preferably 0.05% by mass or less.

In addition to the above, other components that may be contained in the liquid crystal aligning agent include, for example, epoxy group-containing compounds (for example, N, N, N', N'-tetraglycidyl-m-xylene diamine, N, N, N. ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc.), functional silane compounds (eg, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, etc.) ), Antioxidants, metal chelate compounds, curing catalysts, curing accelerators, surfactants, fillers, dispersants, photosensitizers and other additives. The blending ratio of these additives can be appropriately selected according to each compound as long as the effects of the present disclosure are not impaired.

The ratio D of the total mass of the components in the liquid crystal aligning agent other than the compound (A) and the solvent to the total mass of the liquid crystal aligning agent is appropriately selected in consideration of viscosity, volatility, etc., but is preferably 1. It is in the range of 10% by mass. When the ratio D is less than 1% by mass, the film thickness of the coating film becomes too small and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the ratio D exceeds 10% by mass, the film thickness of the coating film becomes excessive and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coatability tends to decrease. It is in.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal element of the present disclosure includes a liquid crystal alignment film formed by using the liquid crystal alignment agent described above. The liquid crystal element can be effectively applied to various applications, for example, a clock, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, a smartphone, various monitors, and a liquid crystal television. , It can be used as various display devices such as information displays, dimming films, retardation films, and the like. When used as a liquid crystal display device, the operation mode of the liquid crystal is not particularly limited, and for example, TN type, STN type, vertically oriented type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB. It can be applied to various operation modes such as (Optically Compensated Bend) type.

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

(Step 1: Formation of coating film)
First, a liquid crystal alignment agent is applied onto the substrate, and preferably the coated surface is heated to form a coating film on the substrate. As the substrate, for example, glass such as float glass and soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (aliphatic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, NESA film (US PPG registered trademark) made of tin oxide (SnO _2), indium oxide - ITO made of tin oxide _{(In 2} O 3 -SnO ₂₎ film Etc. can be used. When manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb-teeth shape and an opposing substrate not provided with an electrode. Is used. As the metal film, a film made of a metal such as chromium can be used. The liquid crystal alignment agent is applied to the substrate by an offset printing method, a spin coating method, a roll coater method, a flexographic printing method or an inkjet printing method, preferably on the electrode forming surface.

After the liquid crystal alignment agent is applied, preheating is preferably performed for the purpose of preventing the applied liquid crystal alignment agent from dripping. The pre-baking temperature is preferably 30 to 200 ° C., and the pre-baking time is preferably 0.25 to 10 minutes. Then, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure of the polymer. The firing temperature (post-baking temperature) is preferably 80 to 300 ° C., and the post-baking time is preferably 5 to 200 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 μm. By applying the liquid crystal alignment agent on the substrate and then removing the organic solvent, a liquid crystal alignment film or a coating film to be a liquid crystal alignment film is formed.

(Step 2: Orientation treatment)
When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, a treatment (alignment treatment) for imparting a liquid crystal alignment ability to the coating film formed in the above step 1 is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation treatment, for example, a rubbing treatment in which the coating film is rubbed in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, and cotton, or a coating film formed on a substrate using a liquid crystal alignment agent is irradiated with light. Examples thereof include a photo-alignment treatment for imparting a liquid crystal alignment ability to the coating film. On the other hand, in the case of manufacturing a vertically oriented liquid crystal element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film is subjected to alignment treatment (rubbing treatment, photoalignment treatment). Etc.) may be applied. A liquid crystal alignment agent suitable for a vertically oriented liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

(Step 3: Construction of liquid crystal cell)
A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above and arranging the liquid crystal between the two substrates arranged opposite to each other. In order to manufacture a liquid crystal cell, for example, (1) two substrates are arranged facing each other through a gap (spacer) so that the liquid crystal alignment films face each other, and the peripheral portion of the two substrates is covered with a sealant. A method of sealing the injection holes after laminating, injecting and filling the liquid crystal in the substrate surface and the cell gap partitioned by the sealant, (2) sealing at a predetermined place on one substrate on which the liquid crystal alignment film is formed. A method in which an agent is applied, liquid crystal is dropped onto a predetermined number of places on the liquid crystal alignment film surface, the other substrate is bonded so that the liquid crystal alignment film faces each other, and the liquid crystal is spread over the entire surface of the substrate (ODF method). ) Etc. can be mentioned. It is desirable to remove the flow orientation at the time of filling the liquid crystal by further heating the manufactured liquid crystal cell to a temperature at which the used liquid crystal takes an isotropic phase and then slowly cooling it to room temperature.

As the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used. As the spacer, a photo spacer, a bead spacer, or the like can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, the nematic liquid crystal is preferable. Further, for example, a cholesteric liquid crystal, a chiral agent, a ferroelectric liquid crystal or the like may be added to the nematic liquid crystal or the smectic liquid crystal for use.

Subsequently, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretch-oriented and iodine is absorbed is sandwiched between a cellulose acetate protective film, or a polarizing plate made of the H film itself. In this way, a liquid crystal display element can be obtained.

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

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

[Weight average molecular weight Mw of polymer]
The weight average molecular weight Mw is a polystyrene-equivalent value measured by GPC under the following conditions.
Column: Made by Tosoh Corporation, TSKgelGRCXLII
Solvent: Tetrahydrofuran or N, N-dimethylformamide solution containing lithium bromide and phosphoric acid Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidization rate of polyimide]
The polyimide solution was poured into pure water, the obtained precipitate was sufficiently dried under reduced pressure at room temperature, dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidization rate [%] was determined by the following mathematical formula (1).
Imidization rate [%] = (1- (A ¹ / (A ² x α))) x 100 ... (1)
(In formula (1), A ¹ is the peak area derived from the proton of the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid). ) Is the ratio of the number of other protons to one proton of the NH group.)
[Solution viscosity of polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer.
[Epoxy equivalent]
Epoxy equivalents were measured by the hydrochloric acid-methylethylketone method described in JIS C 2105.

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

<Synthesis of polymer>
[Synthesis Example 1: Synthesis of Polyimide (PI-1)]
22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic dianhydride, and 8.6 g (0.08 mol) of p-phenylenediamine (PDA) as diamine. ) And 10.5 g (0.02 mol) of cholestanyl 3,5-diaminobenzoate were dissolved in 166 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to add 20 polyamic acids. A solution containing mass% was obtained. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 90 mPa · s.
Next, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7% by mass, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring closure reaction was carried out at 110 ° C. for 4 hours. .. After the dehydration ring closure reaction, the solvent in the system was replaced with a new NMP (the pyridine and acetic anhydride used in the dehydration ring closure reaction were removed from the system by this operation. The same applies hereinafter), so that the imidization rate was about 68. A solution containing 26% by mass of% polyimide (PI-1) was obtained. A small amount of the obtained polyimide solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by mass was 45 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain polyimide (PI-1).

[Synthesis Example 2: Synthesis of Polyimide (PI-2)]
As tetracarboxylic acid dianhydride, 110 g (0.50 mol) of TCA and 1,3,3a,4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) naphtho [1,2-c] Furan-1,3-dione 160 g (0.50 mol), PDA 91 g (0.85 mol) as diamine, 1,3-bis (3-aminopropyl) tetramethyldisiloxane 25 g ( 0.10 mol), 25 g (0.040 mol) of 3,6-bis (4-aminobenzoyloxy) cholesterol, and 1.4 g (0.015 mol) of aniline as a monoamine were dissolved in 960 g of NMP at 60 ° C. The reaction was carried out in 1 for 6 hours to obtain a solution containing a polyamic acid. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 60 mPa · s.
Next, 2,700 g of NMP was added to the obtained polyamic acid solution, 390 g of pyridine and 410 g of acetic anhydride were added, and a dehydration ring closure reaction was carried out at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new γ-butyrolactone (GBL) to obtain about 2,500 g of a solution containing 15% by mass of polyimide (PI-2) having an imidization ratio of about 95%. Obtained. A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by mass was 70 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain polyimide (PI-2).

[Synthesis Example 3: Synthesis of Polyimide (PI-3)]
A polyamic acid solution was prepared by the same method as in Synthesis Example 1 above, except that the diamine used was changed to 0.08 mol of 3,5-diaminobenzoic acid and 0.02 mol of cholestanyloxy-2,4-diaminobenzene. Obtained. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 80 mPa · s. Next, imidization was carried out by the same method as in Synthesis Example 1 to obtain a solution containing 26% by mass of polyimide (PI-3) having an imidization ratio of about 65%. A small amount of the obtained polyimide solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by mass was 40 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain polyimide (PI-3).

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

[Synthesis Example 5: Synthesis of Polyimide (PI-5)]
The tetracarboxylic acid dianhydride used was changed to 0.08 mol of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 0.02 mol of pyromellitic acid dianhydride, and the diamine used was changed to 0.02 mol. Polyamic acid by the same method as in Synthesis Example 1 above, except that it was changed to 0.098 mol of 4-aminophenyl-4-aminobenzoate (compound (DA-3)) and 0.002 mol of compound (DA-4). A solution was obtained. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 80 mPa · s. Next, imidization was carried out by the same method as in Synthesis Example 1 to obtain a solution containing 26% by mass of polyimide (PI-5) having an imidization ratio of about 65%. A small amount of the obtained polyimide solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by mass was 50 mPa · s. The reaction solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain polyimide (PI-5).

[Synthesis Example 6: Synthesis of Polyamic Acid (PA-1)]
1,2,3,4-cyclobutanetetracarboxylic acid dianhydride (CB) 200 g (1.0 mol) as tetracarboxylic acid dianhydride, 2,2'-dimethyl-4,4'-diaminobiphenyl 210 g as diamine (1.0 mol) was dissolved in a mixed solvent of 370 g of NMP and 3,300 g of γ-butyrolactone (GBL), and the reaction was carried out at 40 ° C. for 3 hours to obtain a polyamic acid having a solid content concentration of 10% by mass and a solution viscosity of 160 mPa · s. A solution was obtained. The polyamic acid solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid (PA-1).

[Synthesis Example 7: Synthesis of Polyamic Acid (PA-2)]
7.0 g (0.031 mol) of TCA as tetracarboxylic dianhydride and 13 g of compound (DA-5) as diamine (corresponding to 1 mol with respect to 1 mol of TCA) were dissolved in 80 g of NMP and 4 at 60 ° C. By carrying out a time reaction, a solution containing 20% by mass of polyamic acid (PA-2) was obtained. The solution viscosity of this polyamic acid solution was 2,000 mPa · s. The compound (DA-5) was synthesized according to the description in Japanese Patent Application Laid-Open No. 2011-10099. The polyamic acid solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid (PA-2).

[Synthesis Example 8: Synthesis of Polyamic Acid (PA-3)]
The above synthesis example except that the diamine used was changed to 0.7 mol of 1,3-bis (4-aminophenethyl) urea (compound (DA-6)) and 0.3 mol of compound (DA-7). A polyamic acid solution was obtained by the same method as in 6. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 100 mPa · s. The polyamic acid solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid (PA-3).

[Synthesis Example 9: Synthesis of Polyamic Acid (PA-4)]
The tetracarboxylic acid dianhydride used was changed to 1.0 mol of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and the diamine used was p-phenylenediamine 0. Polyamic acid solution by the same method as in Synthesis Example 6 above, except that it was changed to 3 mol, 0.2 mol of compound (DA-7), and 0.5 mol of 1,2-bis (4-aminophenoxy) ethane. Got A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 90 mPa · s. The polyamic acid solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid (PA-4).

[Synthesis Example 10: Synthesis of Polyamic Acid (PA-5)]
Except that the diamine used was changed to 0.2 mol of 2,4-diamino-N, N-diallylaniline, 0.2 mol of 4,4'-diaminodiphenylamine, and 0.6 mol of 4,4'-diaminodiphenylmethane. Obtained a polyamic acid solution by the same method as in Synthesis Example 6 above. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 95 mPa · s. The polyamic acid solution was then poured into a large excess of methanol to precipitate the reaction product. The precipitate was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid (PA-5).

[Synthesis Example 11: Synthesis of Polyamic Acid Ester (PAE-1)]
0.035 mol of 2,4-bis (methoxycarbonyl) -1,3-dimethylcyclobutane-1,3-dicarboxylic acid was added to 20 ml of thionyl chloride, N, N-dimethylformamide was added in a catalytic amount, and then the temperature was increased to 80 ° C. Stirred for 1 hour. Then, the reaction solution was concentrated, and the residue was dissolved in 113 g of γ-butyrolactone (GBL) (this solution was designated as reaction solution A). Separately, 0.01 mol of p-phenylenediamine, 0.01 mol of 1,2-bis (4-aminophenoxy) ethane, and 0.014 mol of compound (DA-8) were added to 6.9 g of pyridine, 44.5 g of NMP, and GBL33. It was dissolved in addition to 5.5 g and cooled to 0 ° C. Then, the reaction solution A was slowly added dropwise to this solution over 1 hour, and after completion of the addition, the mixture was stirred at room temperature for 4 hours. The obtained solution of polyamic acid ester was added dropwise to 800 ml of pure water with stirring, and the precipitated precipitate was filtered. Subsequently, it was washed 5 times with 400 ml of isopropyl alcohol (IPA) and dried to obtain 15.5 g of polymer powder. The weight average molecular weight Mw of the obtained polyamic acid ester (PAE-1) was 34,000.

[Synthesis Example 12: Synthesis of Polyorganosiloxane (APS-1)]
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methylisobutylketone and 10.0 g of triethylamine at room temperature. Mixed in. Then, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then the reaction was carried out at 80 ° C. for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out, washed with a 0.2 mass% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a reactive polyorganosiloxane. (EPS-1) was obtained as a viscous transparent liquid. ^{When 1} H-NMR analysis was performed on this reactive polyorganosiloxane (EPS-1), a peak based on an epoxy group was obtained near chemical shift (δ) = 3.2 ppm according to the theoretical intensity, and during the reaction. It was confirmed that no side reaction of the epoxy group occurred. The weight average molecular weight Mw of the obtained reactive polyorganosiloxane was 3,500, and the epoxy equivalent was 180 g / mol.
Next, in a 200 mL three-necked flask, 10.0 g of reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, 3.98 g of 4- (dodecyloxy) benzoic acid as a reactive compound, and a catalyst. As a result, 0.10 g of UCAT 18X (trade name, manufactured by Sun Appro Co., Ltd.) was charged, and the reaction was carried out at 100 ° C. for 48 hours with stirring. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, the organic layer was dried over magnesium sulfate, and then the solvent was distilled off to obtain a liquid crystal oriented polyorganosiloxane (APS-). 1) was obtained in 9.0 g. The weight average molecular weight Mw of the obtained polymer was 9,900.

[Example 1]
1. 1. Preparation of liquid crystal alignment agent Anisole (Compound a) and Butyl cellosolve (BC) were added to the polyimide (PI-1) obtained in Synthesis Example 1 above, and the polymer concentration was 3.5% by mass and the mixing ratio of the solvent was a compound. The solution was a: BC = 70:30 (mass ratio). After sufficiently stirring this solution, a liquid crystal alignment agent (S-1) was prepared by filtering through a filter having a pore size of 0.2 μm. The liquid crystal alignment agent (S-1) is mainly for manufacturing a vertically oriented liquid crystal display element.

2. Evaluation of coating uniformity Above 1. The liquid crystal alignment agent (S-1) prepared in the above was applied onto a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the inside of the refrigerator was replaced with nitrogen in an oven at 200 ° C. 1 A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) for a time. The surface of the obtained coating film was observed with an atomic force microscope (AFM), the center average roughness (Ra) was measured, and the uniformity of the coating film surface was evaluated. When Ra was 5 nm or less, the coating uniformity was evaluated as “good (◯)”, when it was larger than 5 nm and less than 10 nm, it was evaluated as “possible (Δ)”, and when it was 10 nm or more, it was evaluated as “poor (×)”. As a result, the evaluation was "good" in this example.

3. 3. Evaluation of Applicability to Fine Concavo-convex Surface Using the evaluation ITO electrode substrate 10 shown in FIG. 1, the applicability of the liquid crystal alignment agent to the fine concavo-convex surface was evaluated. As the evaluation ITO electrode substrate 10, a plurality of striped ITO electrodes 12 were arranged on one surface of the glass substrate 11 at predetermined intervals (see FIG. 1). The electrode width A was 50 μm, the distance between the electrodes B was 2 μm, and the electrode height C was 0.2 μm. A liquid crystal alignment agent (S-1) is dropped onto the electrode-forming surface of the evaluation ITO electrode substrate 10 using a wettability evaluation device LSE-A100T (manufactured by Nick) to improve the compatibility of the substrate with the uneven surface. evaluated. At this time, it can be said that the larger the wett spread area S (mm ² / μL) of the droplet with respect to the amount of liquid, the larger the wet spread of the droplet, and the better the coatability of the liquid crystal aligning agent on the fine uneven surface. The evaluation is "very good (○○)" when the area S is 15 mm ² / μL or more, “good (○)” when the area S is 10 mm ² / μL or more and ^{less than 15 mm 2} / μL, and the area. S has a "good (△)", "poor (×)" when the area S is less than 5 mm ² / [mu] L if it is greater than 10 mm ² / [mu] L than 5 mm ² / [mu] L. As a result, in this example, the area S was 10 mm ² / μL, and the applicability to the fine uneven surface was judged to be “good”.

4. Manufacture of vertically oriented liquid crystal display element Liquid crystal aligning agent (S-1) is applied to a glass substrate with a transparent electrode made of a pair (2 sheets) of ITO films using a spinner, and prebaked on a hot plate at 80 ° C. for 1 minute. Was done. Then, the solvent was removed by heating (post-baking) at 200 ° C. for 1 hour in an oven replaced with nitrogen to form a coating film (liquid crystal alignment film) having a film thickness of 0.08 μm. The coating film was subjected to a rubbing treatment using a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a fluff pushing length of 0.1 mm. Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then the substrate was dried in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. It should be noted that this rubbing process is a weak rubbing process performed for the purpose of controlling the collapse of the liquid crystal display and performing the orientation division by a simple method.
An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied by screen printing to the outer periphery of the surface of one of the substrates having the liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates are opposed to each other. The adhesive was heat-cured by overlapping and crimping and heating at 150 ° C. for 1 hour. Next, after filling the gap between the substrates from the liquid crystal injection port with a negative liquid crystal display (MLC-6608 manufactured by Merck), the liquid crystal injection port is sealed with an epoxy adhesive, and further, in order to eliminate the flow orientation during liquid crystal injection. This was heated at 150 ° C. for 10 minutes and then slowly cooled to room temperature. Further, a liquid crystal display element was manufactured by laminating polarizing plates on both outer sides of the substrate so that the polarization directions of the two polarizing plates were orthogonal to each other.

5. Evaluation of variation characteristics (post-bake margin) of pre-tilt angle with respect to post-bake temperature unevenness 4. The pretilt angles of the liquid crystal display elements obtained by preparing the liquid crystal alignment films at different post-bake temperatures (120 ° C., 180 ° C. and 230 ° C.) were measured according to the above method. The measured value at 230 ° C. was used as the reference pretilt angle θp, and the variation characteristic of the pretilt angle with respect to the temperature unevenness of the postbake was evaluated by the difference Δθ (= | θp−θa |) between the reference pretilt angle θp and the measured value θa. It can be said that the smaller Δθ is, the smaller the variation in the pretilt angle with respect to the temperature unevenness is and the better. The measurement of the pre-tilt angle is performed in accordance with the method described in the non-patent document (TJ Scheffer et. Al. J. Appl. Phys. Vo. 19, p. 2013 (1980)). The value of the inclination angle of the liquid crystal molecule from the substrate surface measured by the crystal rotation method using the above was defined as the pretilt angle [°]. The evaluation was "good (○)" when Δθ was 0.2 ° or less, "possible (Δ)" when it was greater than 0.2 ° and less than 0.5 °, 0.5 °. The case of the above was regarded as "defective (x)". As a result, in this example, the post-bake margin was evaluated as "good" when the post-bake temperature was 180 ° C., and "OK" when the post-bake temperature was 120 ° C.

6. Evaluation of bezel unevenness resistance 4. A vertically oriented liquid crystal display element was manufactured using the liquid crystal aligning agent (S-1) according to the above method. The obtained vertically oriented liquid crystal display element was stored under the conditions of 25 ° C. and 50% RH for 30 days, and then driven by an AC voltage of 5 V to observe the lighting state. The evaluation is "very good (○○)" if the brightness difference (more black or more white) is not visually recognized around the sealant, but if the brightness difference disappears within 10 minutes after lighting. "Good (○)", the brightness difference did not disappear within 10 minutes after lighting, but "OK (△)" if the brightness difference disappeared within 20 minutes after lighting, brightness even after 20 minutes. The case where the difference was visually recognized was defined as "defective (x)". As a result, this liquid crystal display element was judged to be "OK".

7. Evaluation of AC afterimage characteristics Except for the fact that the electrode structure is two ITO electrodes (electrode 1 and electrode 2) that can switch voltage application / non-application separately, and that the polarizing plate is not bonded, the above 4. A liquid crystal cell for evaluation was produced by the same method as in the above. The evaluation liquid crystal cell was placed under the condition of 60 ° C., and an AC voltage of 10 V was applied to the electrode 1 for 300 hours without applying a voltage to the electrode 2. Immediately after 300 hours had passed, an AC 3V voltage was applied to both the electrode 1 and the electrode 2, and the difference ΔT [%] in the light transmittance between the two electrodes was measured. At this time, when ΔT is less than 2%, the AC afterimage characteristic is “good (◯)”, when it is 2% or more and less than 3%, it is “possible (Δ)”, and when it is 3% or more, it is “good”. It was evaluated as "defective (x)". As a result, it was evaluated as "good" in this example.

8. Evaluation of DC afterimage characteristics 7. The evaluation liquid crystal cell produced in the above was placed under the condition of 60 ° C., a voltage of 0.5 V DC was applied to the electrode 1 for 24 hours, and the voltage remaining on the electrode 1 immediately after the DC voltage was turned off (residual DC voltage) was applied. Obtained by the flicker elimination method. At this time, when the residual DC voltage is less than 100 mV, the DC afterimage characteristic is “good (◯)”, when it is 100 mV or more and less than 300 mV, it is “possible (Δ)”, and when it is 300 mV or more, it is “defective (defective). ×) ”was evaluated. As a result, it was evaluated as "good" in this example.

[Examples 2 to 4 and Comparative Examples 1 to 5]
A liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the compounding formulations were as shown in Table 1 below. In addition, various evaluations were carried out in the same manner as in Example 1 using the prepared liquid crystal alignment agent. The evaluation results are shown in Table 2 below.

[Example 5]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-5) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. The liquid crystal alignment agent (S-5) is mainly for manufacturing a horizontally oriented liquid crystal display element.
2. Evaluation of Liquid Crystal Aligning Agent The coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (S-5) was used. The results are shown in Table 2 below.

3. 3. Manufacture of rubbing FFS type liquid crystal display element A glass substrate in which a flat plate electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) are laminated on one side in this order, and a counter glass substrate on which no electrode is provided. A liquid crystal aligning agent (S-5) was applied onto each surface using a spinner, and heated (prebaked) on a hot plate at 80 ° C. for 1 minute. Then, the inside of the chamber was dried (post-baked) for 1 hour in a nitrogen-substituted oven at 200 ° C. to form a coating film having an average film thickness of 0.08 μm. Next, the surface of the coating film was subjected to a rubbing treatment using a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a fluff pushing length of 0.4 mm. Then, it was ultrasonically cleaned in ultrapure water for 1 minute and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was screen-printed on the pair of substrates having the liquid crystal alignment film, leaving the liquid crystal injection port on the edge of the surface on which the liquid crystal alignment film was formed. Then, the substrates were overlapped and crimped, and the adhesive was thermoset at 150 ° C. for 1 hour. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of liquid crystal injection, this was heated at 120 ° C. and then slowly cooled to room temperature to produce a liquid crystal cell. When stacking a pair of substrates, the rubbing method of each substrate was set to be antiparallel. Further, the polarizing plates were attached so that the polarization directions of the two polarizing plates were parallel and orthogonal to the rubbing direction, respectively. For the top electrode, the line width of the electrode was set to 4 μm, and the distance between the electrodes was set to 6 μm. As the top electrode, four types of driving electrodes, electrode A, electrode B, electrode C, and electrode D, were used. In this case, the bottom electrode acts as a common electrode that acts on all of the four drive electrodes, and each of the regions of the four drive electrodes becomes a pixel region.
4. Evaluation of rubbing FFS type liquid crystal display element 3. The post-bake margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated in the same manner as in Example 1 except that the rubbing FFS type liquid crystal display element or liquid crystal cell produced according to the above method was used. Further, using the liquid crystal alignment agent (S-5), the above 3. A rubbing FFS type liquid crystal display element was manufactured according to the method described in the above, and the bezel unevenness resistance was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Examples 6 and 7]
Liquid crystal alignment agents (S-6) and (S-7) were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. Further, except that the liquid crystal aligning agents (S-6) and (S-7) were used, the coating uniformity and the coating property on the finely uneven surface were evaluated in the same manner as in Example 1, and the same as in Example 5. In the same manner, a rubbing FFS type liquid crystal display element or a liquid crystal cell was manufactured and various evaluations were performed. The results are shown in Table 2 below.

[Example 8]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-8) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. The liquid crystal alignment agent (S-8) is mainly used for manufacturing a PSA type liquid crystal display element.
2. Evaluation of Liquid Crystal Aligning Agent The coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (S-8) was used. The results are shown in Table 2 below.

3. 3. Preparation of liquid crystal composition With respect to 10 g of nematic liquid crystal (MLC-6608 manufactured by Merck Co., Ltd.), 5% by mass of the liquid crystal compound represented by the following formula (L1-1) and the following formula (L2-1) are represented. The liquid crystal composition LC1 was obtained by adding 0.3% by mass of the photopolymerizable compound and mixing the compounds.

4. Manufacture of PSA-type liquid crystal display element A liquid crystal alignment film is formed in the same manner as in the method described in "4. Manufacture of vertical alignment type liquid crystal display element" of Example 1 except that the liquid crystal alignment agent (S-8) is used. A pair (two) of substrates having the same was obtained. Next, a liquid crystal cell was produced in the same manner as in Example 1 except that the liquid crystal composition LC1 prepared above was used instead of MLC-6608 and that the polarizing plate was not bonded. Next, an AC 10V having a frequency of 60 Hz was applied between the electrodes to the liquid crystal cell obtained above, and in a state where the liquid crystal was driven, 50 ultraviolet rays were emitted using an ultraviolet irradiation device using a metal halide lamp as a light source. The irradiation was performed at an irradiation rate of 000 J / m ^2. The irradiation amount is a value measured using a photometer measured based on a wavelength of 365 nm. Further, a liquid crystal display element was manufactured by laminating polarizing plates on both outer sides of the substrate so that the polarization directions of the two polarizing plates were orthogonal to each other.
5. Evaluation of PSA type liquid crystal display element 4. The post-bake margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated in the same manner as in Example 1 except that the PSA type liquid crystal display element or liquid crystal cell produced according to the method described in the above was used. Further, using the liquid crystal alignment agent (S-8), the above 4. A PSA type liquid crystal display element was manufactured according to the method described in the above, and the bezel unevenness resistance was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Examples 9 to 11, 12, 22, and Comparative Example 6]
Liquid crystal alignment agents were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. Further, except that each liquid crystal alignment agent was used, the coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1, and the PSA type liquid crystal display element or liquid crystal was evaluated in the same manner as in Example 8. The cell was manufactured and various evaluations were performed. The results are shown in Table 2 below.

[Example 12]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-12) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. The liquid crystal alignment agent (S-12) is mainly for manufacturing an optical vertical alignment type liquid crystal display element.
2. Evaluation of Liquid Crystal Aligning Agent The coating uniformity and the coating property on a finely uneven surface were evaluated in the same manner as in Example 1 except that the liquid crystal alignment agent (S-12) was used. The results are shown in Table 2 below.

3. 3. Manufacture of optical vertical alignment type liquid crystal display element A liquid crystal alignment agent (S-12) was used, and instead of the rubbing treatment, the film was irradiated with polarized ultraviolet rays using an Hg-Xe lamp and a Gran Tailor prism. , An optical vertical alignment type liquid crystal display element was manufactured in the same manner as described in "4. Manufacture of a vertically oriented liquid crystal display element" of Example 1. The irradiation of polarized ultraviolet rays was performed from a direction inclined by 40 ° from the normal of the substrate, the irradiation amount was 200 J / m ² , and the polarization direction was p-polarized light. This irradiation amount is a value measured using a photometer measured based on a wavelength of 313 nm.
4. Evaluation of optical vertical alignment type liquid crystal display element 3. The post-bake margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated in the same manner as in Example 1 except that the optical vertical alignment type liquid crystal display element or liquid crystal cell produced according to the method described in the above was used. Further, using the liquid crystal alignment agent (S-12), the above 3. An optical vertical liquid crystal display element was manufactured according to the method described in the above, and the bezel unevenness resistance was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Examples 13 and 14]
Liquid crystal alignment agents were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. Further, the coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that each liquid crystal alignment agent was used, and the optical vertical alignment type liquid crystal display element was evaluated in the same manner as in Example 12. Alternatively, a liquid crystal cell was manufactured and the post-bake margin, bezel unevenness resistance, AC afterimage characteristics and DC afterimage characteristics were evaluated. The results are shown in Table 2 below.

[Example 15]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-15) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. The liquid crystal alignment agent (S-15) is mainly used for manufacturing an optical horizontal type liquid crystal display element.
2. Evaluation of Liquid Crystal Aligning Agent The coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (S-15) was used. The results are shown in Table 2 below.

3. 3. Manufacture of optical FFS type liquid crystal display element A liquid crystal alignment agent (S-15) was used, and instead of the rubbing treatment, the film was irradiated with polarized ultraviolet rays using an Hg-Xe lamp and a Grantailer prism. An optical FFS type liquid crystal display element was manufactured in the same manner as described in "3. Manufacture of rubbing FFS type liquid crystal display element" of Example 5. The irradiation of polarized ultraviolet rays was performed from the vertical direction from the substrate, the irradiation amount was 10,000 J / m ² , and the polarization direction was a direction orthogonal to the direction of the rubbing treatment in Example 5. This irradiation amount is a value measured using a photometer measured based on a wavelength of 254 nm.
4. Evaluation of optical FFS type liquid crystal display element 3. The post-bake margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated in the same manner as in Example 1 except that the optical FFS type liquid crystal display element or liquid crystal cell produced according to the method described in the above was used. Further, using the liquid crystal alignment agent (S-15), the above 3. An optical FFS type liquid crystal display element was manufactured according to the method described in the above, and the bezel unevenness resistance was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[Examples 16 to 20]
Liquid crystal alignment agents were prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. Further, the coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that each liquid crystal alignment agent was used, and the optical FFS type liquid crystal display element or the optical FFS type liquid crystal display element or in the same manner as in Example 15. A liquid crystal cell was manufactured and various evaluations were performed. The results are shown in Table 2 below.

[Example 23]
1. 1. Preparation of liquid crystal alignment agent A liquid crystal alignment agent (S-23) was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1 below. The liquid crystal alignment agent (S-23) is mainly used for manufacturing a TN mode type liquid crystal display element.
2. Evaluation of Liquid Crystal Aligning Agent The coating uniformity and the coating property on the fine uneven surface were evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent (S-23) was used. The results are shown in Table 2 below.

3. 3. Manufacture of TN type liquid crystal display element Using a liquid crystal alignment agent (S-23), the rubbing process is performed by a rubbing machine having a roll wrapped with rayon cloth, a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a fluff pushing. A pair (two sheets) of substrates having a liquid crystal alignment film are provided in the same manner as in the method described in "4. Manufacture of a vertically oriented liquid crystal display element" of Example 1 except that the length is 0.4 mm. Obtained. Next, instead of MLC-6608, a positive liquid crystal display (MLC-6221 made by Merck) was used so that the rubbing methods of the respective substrates were orthogonal to each other when the pair of substrates were overlapped, and the two polarizing plates were used. A TN type liquid crystal display element was manufactured in the same manner as in Example 1 except that the polarization direction was parallel to the rubbing direction of each substrate.
4. Evaluation of TN type liquid crystal display element 3. The post-bake margin, AC afterimage characteristic, and DC afterimage characteristic were evaluated in the same manner as in Example 1 except that the TN type liquid crystal display element or liquid crystal cell produced according to the method described in the above was used. Further, using the liquid crystal alignment agent (S-23), the above 3. A TN type liquid crystal display element was manufactured according to the method described in the above, and the bezel unevenness resistance was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

In Table 1, the numerical values of the polymer components indicate the blending ratio (parts by mass) of each polymer with respect to the total 100 parts by mass of the polymer components used for preparing the liquid crystal alignment agent. The numerical values in the ratio column of compound [A], "solvent [B] and other solvents" are for 100 parts by mass of the total of compound [A], solvent [B] and other solvents used in the preparation of the liquid crystal alignment agent. The compounding ratio (part by mass) of the compound is shown. "-" Indicates that the compound was not used. The abbreviations of the compounds are as follows.
(Compound [A])
a: Anisole (bp: 154 ° C, mp: -38 ° C)
b: 2-Methoxytoluene (bp: 177 ° C, mp: -47 ° C)
c: o-ethoxyanisole (bp: 217 ° C, mp: -1 ° C)
d: 1,3-diethoxybenzene (bp: 235 ° C, mp: 10 ° C)
e: m-tolyl acetate (bp: 212 ° C, mp: 12 ° C)
f: 1,2-Methylenedioxybenzene (bp: 172 ° C, mp: -10 ° C)
(Solvent [B] and other solvents)
g: N-methyl-2-pyrrolidone h: o-xylene i: m-cresol j: 2-ethoxyphenol k: butyl cellosolve m: 3-methoxy-1-butanol n: cyclopentanone

As can be seen from Table 2, Examples 1 to 23 containing the compound [A] are "very good" and "good" in all of the coating uniformity, the uneven coating property, the post-bake margin, the bezel unevenness resistance and the afterimage property. Or, the evaluation was "OK", and various characteristics were improved in a well-balanced manner. In particular, in the examples using the compounds b to e having two substituents on the benzene ring, the effect of improving the bezel unevenness resistance is high, and in the examples using the compounds d and e, the coating property on the fine uneven surface is further improved. The improvement effect was also high. Further, in the example using the compound f having a condensed ring, the effect of improving the coatability on the fine uneven surface was high. On the other hand, Comparative Examples 1 to 6 containing no compound [A] were inferior in coatability to the fine uneven surface as compared with Examples. Further, Comparative Examples 1, 3 to 6 were inferior in uniformity of the coating film surface to Examples, and Comparative Examples 4 and 5 were inferior in bezel unevenness resistance to Examples.

10 ... Evaluation ITO electrode substrate, 11 ... Glass substrate, 12 ... ITO electrode

Claims (8)

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

(In the formula (1), R ¹ is an alkyl group having 1 to 4 carbon atoms, -CO-CH ₃ , or -R ^4- OH (where R ⁴ is an alkanediyl group having 1 to 4 carbon atoms). . R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N is 1 or 2. However, when n is 1, R ² is an alkyl group having 1 to 4 carbon atoms. If is 2, if .n ^{R 2} is a hydrogen atom is 2, a plurality of ^{R 1} in the formula (1) may be the same or different from each other. formula in (2), ^{R 3} is, It is an alcoholic group having 1 to 3 carbon atoms.) The liquid crystal alignment agent according to claim 1, wherein the compound [A] has a melting point of 25 ° C. or lower and a boiling point of 150 ° C. or higher at 1 atm. The liquid crystal alignment agent according to claim 1 or 2, further containing a solvent [B] which is at least one selected from the group consisting of an alcohol solvent, a chain ester solvent, an ether solvent and a ketone solvent. The liquid crystal alignment agent according to claim 3, wherein the content ratio of the compound [A] is 10% by mass or more with respect to the total amount of the compound [A] and the solvent [B]. Claims 1 to 1, wherein the polymer component includes at least one selected from the group consisting of a polymer having a structural unit derived from a polyamic acid, a polyamic acid ester, a polyimide, a polyamide, and a monomer having a polymerizable unsaturated bond. The liquid crystal aligning agent according to any one of 4. A method for manufacturing a liquid crystal element provided with a liquid crystal alignment film.
A method for manufacturing a liquid crystal element, which forms the liquid crystal alignment film using the liquid crystal alignment agent according to any one of claims 1 to 5. A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 5. A liquid crystal element including the liquid crystal alignment film according to claim 7.

Images