JP2016051165A - Liquid crystal alignment agent, liquid crystal alignment film and manufacturing method of the same, liquid crystal display device, and phase difference film and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal alignment agent that provides a liquid crystal display device having good afterimage characteristics and reliability.SOLUTION: A compound (X) having a silicon-silicon bond is made contained in a liquid crystal alignment agent. Examples of the compound (X) include a compound having a partial structure represented by the following formula (1), where Rand Rare each independently a hydrogen atom or a monovalent organic group; "*" represents a coupling hand; at least one of the two "*"s is bonded to a silicon atom.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a manufacturing method thereof, a liquid crystal display element, a retardation film and a manufacturing method thereof.

  Conventionally, as a liquid crystal display element, various drive systems having different electrode structures, properties of liquid crystal molecules to be used, manufacturing processes, and the like have been developed. For example, a TN (Twisted Nematic) type and an STN (Super Twisted Nematic) type have been developed. Various liquid crystal display elements such as VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (fringe field switching) are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyamic acid or polyimide is generally used from the viewpoints of various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

  In recent years, large-screen high-definition liquid crystal televisions are mainly used, and small display terminals such as smartphones and tablet PCs are widely used, and the demand for high-definition liquid crystal panels is increasing. Based on this background, various liquid crystal aligning agents have been proposed in order to improve the display quality and reliability of the liquid crystal panel (see, for example, Patent Document 1). Patent Document 1 discloses that a liquid crystal aligning agent is contained in a liquid crystal aligning agent together with a polyamic acid or polyimide polymer component and a liquid crystal aligning agent is formed using the liquid crystal aligning agent. And improving reliability.

  In addition, various optical materials are used for liquid crystal display elements. Above all, retardation films eliminate the object of viewing color dependency and the viewing angle dependency that the display color and contrast ratio change depending on the visual direction. It is used for the purpose. As such retardation films, those having a liquid crystal alignment film formed on the surface of a substrate such as a TAC film and a liquid crystal layer formed by curing a polymerizable liquid crystal on the surface of the liquid crystal alignment film are known. ing. In recent years, a liquid crystal alignment film in a retardation film has been produced by using a photo-alignment method that imparts liquid crystal alignment ability by irradiating a radiation-sensitive organic thin film formed on the substrate surface with polarized or non-polarized radiation. Various liquid crystal aligning agents for retardation films for producing a liquid crystal aligning film by such a method have been proposed (for example, see Patent Document 2).

JP 2008-299318 A JP 2012-37868 A

  With the recent increase in definition of liquid crystal panels, the demands for reduction in burn-in and reliability have become increasingly severe, and the development of new liquid crystal aligning agents has been demanded to meet these strict requirements. Further, when a retardation film is produced using a liquid crystal aligning agent, it is required that the adhesiveness to the substrate can withstand long-term use (adhesion reliability).

  The present invention has been made in view of the above problems, and an object thereof is to provide a liquid crystal aligning agent capable of improving the afterimage characteristics and reliability of a liquid crystal display element. Another object is to provide a liquid crystal aligning agent capable of obtaining a retardation film having good adhesion reliability.

  The present inventors diligently studied to solve the problems of the prior art as described above, and focused on compounds having a silicon-silicon bond such as polysilane. And when the compound which has a silicon- silicon bond was contained in the liquid crystal aligning agent, it discovered that the afterimage characteristic of a liquid crystal display element and the improvement effect of reliability were acquired, and came to complete this invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film and method for producing the same, liquid crystal display element, retardation film and method for producing the same.

  In one aspect, the present invention provides a liquid crystal aligning agent containing compound (X) having a silicon-silicon bond.

  In another aspect, a liquid crystal alignment film formed using the liquid crystal alignment agent is provided. Moreover, a liquid crystal display element provided with the said liquid crystal aligning film and a phase difference film provided with the said liquid crystal aligning film are provided. Furthermore, in another one aspect, a liquid crystal alignment film comprising: a step of applying the liquid crystal alignment agent on a substrate to form a coating film; and a step of irradiating the coating film with light to impart liquid crystal alignment ability. A manufacturing method is provided. Furthermore, in another aspect, the step of coating the liquid crystal aligning agent on a substrate to form a coating film, the step of irradiating the coating film with light, and the polymerization on the coating film after the light irradiation And a step of applying and curing a functional liquid crystal, and a method for producing a retardation film.

  According to the liquid crystal aligning agent containing the compound (X) having a silicon-silicon bond, an afterimage characteristic of the liquid crystal display element (particularly, a burn-in characteristic called “DC afterimage” caused by a residual charge accumulated by application of a DC voltage) Reliability can be improved. Moreover, a retardation film having good adhesion reliability to the substrate can be obtained.

The schematic block diagram of a FFS type liquid crystal display element. The plane schematic diagram of the top electrode used for manufacture of a rubbing alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of a photo-alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

  The liquid crystal aligning agent according to the present invention is a liquid polymer composition in which a polymer component is preferably dissolved or dispersed in an organic solvent. Below, each component contained in the liquid crystal aligning agent which concerns on this invention, and the other component arbitrarily mix | blended as needed are demonstrated.

（式（１）中、Ｒ^１１及びＲ^１２は、それぞれ独立に水素原子又は１価の有機基である。「＊」はそれぞれ結合手を表す。ただし、２つの「＊」のうち少なくとも１つはケイ素原子に結合している。） <Compound (X)>
The liquid crystal aligning agent which concerns on this invention contains the compound (X) which has a silicon- silicon bond. As the compound (X), for example, a compound having a partial structure represented by the following formula (1) can be used.

(In the formula (1), R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. “*” Represents a bond, respectively, provided that at least one of two “*”. Is bonded to a silicon atom.)

Examples of the monovalent organic group represented by R ¹¹ and R ¹² include a monovalent hydrocarbon group having 1 to 30 carbon atoms; and the methylene group of the hydrocarbon group is represented by —O—, —S—, —CO—, —COO. A group substituted with a divalent functional group such as —, —COS—, —NR ¹³ —, —CO—NR ¹³ — (wherein R ¹³ is a monovalent hydrocarbon group having 1 to 10 carbon atoms); At least one hydrogen atom of the monovalent hydrocarbon group having 1 to 30 carbon atoms is substituted with a hydroxyl group, nitro group, amino group, cyano group, halogen atom, carboxyl group, phosphino group, (meth) acryloyl group, In addition to a group substituted with a substituent such as a (meth) acryloyloxy group, an alkoxycarbonyl group, and an acyl group; a monovalent group having a heterocyclic ring; a hydroxyl group, an alkylsilyl group, an alkoxysilyl group, and the like. R ¹¹ and R ¹² may be the same as or different from each other. R ¹¹ and R ¹² are preferably a monovalent hydrocarbon group.

  Here, in the present specification, the “hydrocarbon group” means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “chain hydrocarbon group” means a linear hydrocarbon group and a branched hydrocarbon group that are composed only of a chain structure without including a cyclic structure in the main chain. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be comprised only by the structure of an alicyclic hydrocarbon, The thing which has a chain structure in the part is also included. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific examples when R ¹¹ and R ¹² are monovalent hydrocarbon groups include chain hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups. And alkyl groups such as octyl group, nonyl group, and decyl group; alkenyl groups such as vinyl group and allyl group; and the like, which may be linear or branched. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cyclohexenyl group; examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, a benzyl group, and a phenethyl group. Group, phenylpropyl group, α-methylbenzyl group, diphenylmethyl group, naphthyl group (including α-naphthyl group and β-naphthyl group), methylnaphthyl group, biphenylene group, anthryl group, phenanthryl group, etc. be able to.

（式（１−１）中、Ｒ^２１は環部分に置換基を有していてもよい１価の芳香環基であり、Ｒ^１２は水素原子又は１価の有機基である。「＊」はそれぞれ結合手を表す。ただし、２つの「＊」のうち少なくとも１つはケイ素原子に結合している。） From the viewpoint of increasing sensitivity to light, compound (X) preferably has at least one silicon atom constituting a silicon-silicon bond bonded to an aromatic ring. As the compound (X) having such a structure, for example, in the partial structure represented by the above formula (1), at least one of R ¹¹ and R ¹² may have a substituent in the ring portion. Examples thereof include compounds that are monovalent aromatic ring groups. In this case, compound (X) has a partial structure represented by the following formula (1-1).

(In Formula (1-1), R ²¹ is a monovalent aromatic ring group which may have a substituent in the ring portion, and R ¹² is a hydrogen atom or a monovalent organic group. “*”. Each represents a bond, provided that at least one of the two “*” is bonded to a silicon atom.)

In the above formula (1-1), the monovalent aromatic ring group of R ²¹ is a group obtained by removing one hydrogen atom from a ring portion in a substituted or unsubstituted aromatic ring. Examples of the aromatic ring include benzene, naphthalene, anthracene and phenanthrene. When the aromatic ring has a substituent, examples of the substituent include monovalent hydrocarbon groups such as a methyl group, an ethyl group, a propyl group, and a vinyl group; a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. And the like, and the substituents exemplified in the description of the monovalent organic groups of R ¹¹ and R ¹² . An alkyl group or an alkoxy group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.
R ²¹ is preferably a monovalent aromatic ring group having a substituent in the ring portion from the viewpoint of heat resistance. Among the above, from the viewpoint of affinity with liquid crystal, a phenyl group or a substituted phenyl group is preferable.
R ¹² in the above formula (1-1) is not particularly limited, but is preferably a monovalent hydrocarbon group having 1 to 30 carbon atoms.

  Compound (X) preferably has a plurality of silicon-silicon bonds. This silicon-silicon bond may be incorporated in a part of the polymer component that can be the main component of the liquid crystal alignment film, or the compound (X) is contained as an additive separately from the polymer component. Also good. Among these, the latter is preferable from the viewpoint that the type of the compound (X) to be used is hardly restricted and the introduction of the silicon-silicon bond into the liquid crystal aligning agent is relatively easy.

（式（Ｘａ−１）〜式（Ｘａ−３）中、Ｒ^１〜Ｒ^４はそれぞれ独立に１価の有機基である。ｍ及びｎは「ｍ＋ｎ≧１」を満たす整数であり、構造単位ごとのｍ及びｎはそれぞれ同じでも異なっていてもよい。ｒ、ｓ及びｔは「４≦（ｒ＋ｓ）×ｔ≦２０」を満たす整数である。） <Polysilane>
When compound (X) is blended like an additive, polysilane can be preferably used as compound (X). The polysilane to be used may be linear, branched, cyclic or network-like, or may have a structure combining these. Specifically, for example, a linear polysilane having a structural unit represented by the following formula (Xa-1), a branched or network polysilane having a structural unit represented by the following formula (Xa-2), the following formula And cyclic polysilane represented by (Xa-3).

(In Formula (Xa-1) to Formula (Xa-3), R ^{1 to} R ⁴ are each independently a monovalent organic group. M and n are integers satisfying “m + n ≧ 1”, and are structural units. M and n may be the same or different, and r, s, and t are integers satisfying “4 ≦ (r + s) × t ≦ 20”.)

Specific examples of the monovalent organic group R ¹ to R ⁴ is ^a description of the monovalent organic group for ^{R 11} and ^{R 12} are applied. It is preferable that at least one of R ^{1 to} R ⁴ is a monovalent aromatic ring group which may have a substituent in the ring portion. The description of R ²¹ is applied to the description of the monovalent aromatic ring group. Specifically, examples of R ²¹ include a phenyl group, a tolyl group, a xylyl group, an α-naphthyl group, a β-naphthyl group, and the like, and a monovalent aromatic ring group having a substituent in the ring portion is preferable. A tolyl group is particularly preferred. In addition, when two or more of R ^{1 to} R ⁴ are monovalent aromatic ring groups that may have a substituent in the ring portion, they may be the same as or different from each other.
When the polysilane is acyclic, examples of the group introduced into the terminal portion include a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, and a silyl group.

Specific examples of the polysilane include polydialkylsilanes such as polydimethylsilane, polymethylpropylsilane, polymethylbutylsilane, polymethylpentylsilane, polydibutylsilane, polydihexylsilane, and dimethylsilane-methylhexylsilane copolymer. A polyalkylcycloalkylsilane such as polymethylcyclohexylsilane;
Polymethylphenylsilane, polymethyl (4-tolyl) silane, methylphenylsilane-diphenylsilane copolymer, dimethylsilane-methylphenylsilane copolymer, dimethylsilane-phenylhexylsilane copolymer, dimethylsilane-methylnaphthylsilane copolymer Polyalkylarylsilanes such as polymers; polydiarylsilanes such as polydiphenylsilane, polydi (4-tolyl) silane, polyphenylnaphthylsilane;
Cross-linked polysilanes such as polyphenylsilin, polymethylsilin, diphenylsilane-phenylsilin copolymer, diphenylsilane-methylsilin copolymer, dimethylsilane-methylsilin copolymer; decaphenylcyclopentasilane, decamethylcyclopentasilane, And cyclic polysilanes such as dodecaphenylcyclohexasilane and dodecamethylcyclohexasilane; Note that “silin” means a structural unit in which silicon atoms are three-dimensionally bonded. Polysilane can be used individually by 1 type or in combination of 2 or more types.

Regarding the degree of polymerization of the polysilane, the linear polysilane is 2 or more, preferably 5 or more, and more preferably 10 or more. The upper limit of the degree of polymerization is not particularly limited, but is preferably 100 or less, more preferably 80 or less, and even more preferably 50 or less.
The degree of polymerization of the branched or network polysilane is preferably 10 or more, and more preferably 10 to 100. The degree of polymerization of the cyclic polysilane is usually 4 or more, preferably 5 to 12, and more preferably 5 to 10.

  The molecular weight of polysilane is preferably 300 to 20,000 in terms of number average molecular weight. When the number average molecular weight is less than 300, it is difficult to obtain the effect of improving the reliability and the afterimage characteristics. There is a tendency to be inferior. Preferably it is 350-10,000, More preferably, it is 400-8,000, Most preferably, it is 500-5,000. In addition, the said value is the polystyrene conversion value measured by the gel permeation chromatography.

<Polymer component>
The liquid crystal aligning agent which concerns on this invention contains the polymer component which can become a main component of a liquid crystal aligning film. The main skeleton of such a polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polysiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) Main skeletons such as acrylate may be mentioned.
Among these, it is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyester, and poly (meth) acrylate from the viewpoint of heat resistance, mechanical strength, affinity with liquid crystal, and the like. It is preferably an at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. In addition, the polymer used for preparation of a liquid crystal aligning agent may be only 1 type, and 2 or more types may be sufficient as it. (Meth) acrylate is meant to include acrylate and methacrylate.

[Polyamic acid]
The polyamic acid contained in the liquid crystal aligning agent according to the present invention can be obtained, for example, by reacting tetracarboxylic dianhydride with diamine.
(Tetracarboxylic dianhydride)
Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. it can. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-di Oxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8 -Methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro -3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3 , 5,6-To Carboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-di Anhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1] .0 ^2,6] undecane -3,5,8,10- tetraone, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene -2, 3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydro Trimellitate ) Etc .;

  Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like; respectively, and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, as tetracarboxylic dianhydride used for the synthesis | combination of a polyamic acid, these 1 type can be used individually or in combination of 2 or more types.

  As tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5 is preferable in that the liquid crystal orientation and the solubility in a solvent can be improved. : 6-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3- Yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetra Carboxylic acid dianhydride, and preferably contains at least one compound selected from the group consisting of pyromellitic dianhydride. The amount of these preferred compounds used (the total amount when two or more are used) is preferably 5 mol% or more based on the total amount of tetracarboxylic dianhydride used for the synthesis of polyamic acid. It is more preferable to set it as 10 mol% or more, and it is more preferable to set it as 20 mol% or more.

(Diamine)
Examples of the diamine used for the synthesis of the polyamic acid include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples of these include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis (aminomethyl) cyclohexane. ;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine) and the like;

（式（Ｄ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−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。） Examples of aromatic diamines include dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, and cholesteryloxydiaminobenzene. Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4 -((Aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((amino Phenoxy Methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4 -(4-Heptylcyclohexyl) benzamide, the following formula (D-1)

(In Formula (D-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, 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 an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, provided that a and b are not 0 at the same time.)

Oriented group-containing diamine such as a compound represented by:
p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 1 , 5-bis (4-aminophenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, N, N-bis (4-amino) Phenyl) methylamine, 1,5-diaminonaphthalene, 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, 9,9-bis (4-aminophen Fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropyl Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diamino Acridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, Other diamonds such as N'-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid And so on;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in the formula (D-1) include alkanediyl groups having 1 to 3 carbon atoms, * —O—, * —COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. Examples of the group “—C _c H _{2c + 1} ” include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tridecyl group, and a tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and the like, and these are preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

なお、ポリアミック酸の合成に使用するジアミンとしては、これらの化合物の１種を単独で又は２種以上を適宜選択して使用することができる。 Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formulas (D-1-1) to (D-1-4). .

In addition, as diamine used for the synthesis | combination of a polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.

  When applied to a liquid crystal aligning agent for a TN type, STN type or vertical alignment type liquid crystal display element, a group (orientation group) capable of imparting liquid crystal alignment ability to the coating film is introduced into the side chain of the polyamic acid. Also good. Examples of such an orientation group include a group having a straight chain structure, a group having a mesogen skeleton, and a group having a bulky structure. Specifically, for example, an alkyl group having 4 to 20 carbon atoms, a carbon number of 4 -20-fluoroalkyl group, C4-C20 alkoxy group, group having a steroid skeleton having 17-51 carbon atoms, or a group in which a plurality of rings are bonded directly or via a linking group. The polyamic acid having an orientation group can be obtained, for example, by polymerization containing an orientation group-containing diamine in the monomer composition. In the case of using an orientation group-containing diamine, the blending ratio is preferably 3 mol% or more with respect to the total diamine used in the synthesis, from the viewpoint of improving liquid crystal orientation, and is preferably 5 to 70 mol%. More preferably.

（式（２−１）中、Ａ^１はケイ素−ケイ素結合を有する２価の有機基である。式（２−２）中、Ａ^２はケイ素−ケイ素結合を有する１価の有機基である。） When the compound (X) having a silicon-silicon bond is a polyamic acid, the polyamic acid can be obtained, for example, by using a diamine having a silicon-silicon bond (hereinafter also referred to as “specific diamine”) as a raw material. . Although the structure of specific diamine is not specifically limited, For example, the compound represented by a following formula (2-1), the compound represented by a following formula (2-2), etc. are mentioned.

(In Formula (2-1), A ¹ is a divalent organic group having a silicon-silicon bond. In Formula (2-2), A ² is a monovalent organic group having a silicon-silicon bond. .)

Examples of the divalent organic group represented by A ¹ include a divalent group having a structure represented by the above formula (Xa-1) and at least one methylene group of a divalent hydrocarbon group represented by the above formula (Xa- And a group substituted with the structure represented by 1). Examples of the monovalent organic group for A ² include a group in which at least one methylene group of a monovalent hydrocarbon group is replaced with a structure represented by the above formula (Xa-1). In A ¹ and A ² , it is preferable that at least one silicon atom constituting the silicon-silicon bond is bonded to the aromatic ring.

Specific examples of the specific diamine include compounds represented by the following formulas (DA-1) to (DA-3).

  When synthesizing the polyamic acid as the compound (X), the use ratio of the specific diamine is preferably 3 mol% or more, more preferably 5 to 80 mol%, based on the total diamine used in the synthesis. preferable.

（式（ｐ）中、Ｘ^３は、硫黄原子、酸素原子又は−ＮＨ−である。「＊」はそれぞれ結合手を示す。但し、２つの「＊」のうち少なくとも一つは芳香環に結合している。） When liquid crystal alignment ability is imparted to the coating film formed of the liquid crystal aligning agent by a photo-alignment method, a photo-alignment structure may be introduced into the main chain or side chain of the polyamic acid. As the photoalignment structure, a group exhibiting photoalignment by photoisomerization, photodimerization, photolysis, or the like can be employed. Specifically, for example, an azo-containing group containing an azo compound or a derivative thereof as a basic skeleton, a cinnamic acid-containing group having a cinnamic acid structure containing a cinnamic acid or a derivative thereof as a basic skeleton, a chalcone or a derivative thereof as a basic skeleton A chalcone-containing group containing, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, bicyclo [ 2.2.2] Bicyclo [2.2.2] octene-containing structure containing octene or a derivative thereof as a basic skeleton, the following formula (p)

(In Formula (p), X ³ is a sulfur atom, an oxygen atom or —NH—. “*” Represents a bond, respectively, provided that at least one of two “*” is bonded to an aromatic ring. doing.)

An ester group-containing structure containing a partial structure represented by the above as a basic skeleton, and the like.
Examples of the aromatic ring to which “*” in the formula (p) is bonded include a benzene ring, a naphthalene ring, and an anthracene ring.
The polyamic acid having a photoalignment structure can be obtained, for example, by polymerization containing at least one of a tetracarboxylic dianhydride having a photoalignment structure and a diamine having a photoalignment structure in the monomer composition. In this case, from the viewpoint of photoreactivity, the proportion of the monomer having a photo-alignment structure is preferably 20 mol% or more with respect to the total amount of monomers used for polymer synthesis, and is 30 to 80 mol. % Is more preferable.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above tetracarboxylic dianhydride and diamine together with a molecular weight adjusting agent as necessary. The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, and the ratio which becomes 0.3-1.2 equivalent is more preferable.
Examples of the molecular weight modifier 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 phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine 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, more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

  Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more selected from the first group of organic solvents And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. Or less, more preferably 30% by weight or less.

  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 at least one selected from the group consisting of halogenated phenols is used as a solvent, or a mixture of one or more of these and another organic solvent is preferably used in the above range. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Prefer

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester]
Examples of the polyamic acid ester include [I] a method of reacting the polyamic acid obtained by the above synthesis reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester and a diamine, and [III] tetracarboxylic acid. It can be obtained by a method of reacting a diester dihalide and a diamine.
In this specification, “tetracarboxylic acid diester” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are carboxyl groups. “Tetracarboxylic acid diester dihalide” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are halogenated.

  Here, examples of the esterifying agent used in the method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, and an epoxy group-containing compound. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol; phenols such as phenol and cresol; and acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane and the like; epoxy group-containing Examples of the compound include propylene oxide. In addition, the polyamic acid ester as a compound (X) can be obtained by using the polyamic acid which has a silicon-silicon bond as a polyamic acid made to react with an esterifying agent.

  The tetracarboxylic acid diester used in Method [II] can be obtained by ring-opening tetracarboxylic dianhydride using the above alcohols. The tetracarboxylic acid diester dihalide used in Method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. Moreover, in method [II] and [III], the polyamic acid ester as a compound (X) can be obtained by making at least one part of the diamine used for reaction into specific diamine. The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

  The reaction solution obtained by dissolving the polyamic acid ester may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid ester contained in the reaction solution, Or after purifying the isolated polyamic acid ester, you may use for preparation of a liquid crystal aligning agent. Isolation and purification of the polyamic acid ester can be performed according to a known method.

[Polyimide]
Polyimide can be obtained, for example, by dehydrating and ring-closing imidized polyamic acid synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure may be dehydrated and cyclized. It may be a partially imidized product in which a ring structure coexists. The polyimide used for the reaction preferably has an imidization ratio of 20% or more, more preferably 30 to 99%, and still more preferably 40 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred. In addition, the polyimide as a compound (X) can be obtained by using the polyamic acid which has a silicon- silicon bond as a polyamic acid made to carry out a dehydration ring-closing reaction.

  In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to a polyamic acid solution, as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, polyimide can also be obtained by imidation of polyamic acid ester.

The polyamic acid, polyamic acid ester, and polyimide obtained as described above preferably have a solution viscosity of 20 to 1,800 mPa · s when this is made into a solution having a concentration of 15% by weight. More preferably, it has a solution viscosity of ˜1,500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 15% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamic acid, polyamic acid ester and polyimide is preferably 1,000 to 500,000, more preferably 2,000. ~ 300,000. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

[Polysiloxane]
Polysiloxane can be obtained, for example, by hydrolyzing and condensing a hydrolyzable silane compound.

Examples of silane compounds used in the synthesis of polysiloxane include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and trimethoxysilylpropyl succinic anhydride. Alkoxysilane compounds such as dimethyldimethoxysilane and dimethyldiethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane , 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (3-cyclohexylamino) propyltrimethoxysilane, etc. Containing sulfur-containing alkoxysilane compound;
Epoxy group-containing silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane Compound;
3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, vinyl Examples include unsaturated bond-containing alkoxysilane compounds such as trimethoxysilane, vinyltriethoxysilane, and p-styryltrimethoxysilane; alkoxysilane compounds having a silicon-silicon bond. One of these hydrolyzable silane compounds can be used alone or in combination of two or more. Note that “(meth) acryloxy” means “acryloxy” and “methacryloxy”. By including an alkoxysilane compound having a silicon-silicon bond in the monomer composition, a polysiloxane as the compound (X) can be obtained.

  The hydrolysis / condensation reaction can be carried out by reacting one or more of the above silane compounds with water, preferably in the presence of an appropriate catalyst and an organic solvent. In the hydrolysis / condensation reaction, the proportion of water used is preferably 0.5 to 100 mol, more preferably 1 to 30 mol, per 1 mol of the silane compound (total amount).

Examples of the catalyst used in the hydrolysis / condensation reaction include acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds and the like. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, and should be set as appropriate. For example, it is preferably 0.01 to 3 times the total amount of the silane compound. More preferably, it is 0.05-1 times mole.
Examples of the organic solvent used in the above hydrolysis / condensation reaction include hydrocarbons, ketones, esters, ethers, alcohols and the like. Among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The use ratio of the organic solvent is preferably 10 to 10,000 parts by weight, and more preferably 50 to 1,000 parts by weight with respect to a total of 100 parts by weight of the silane compounds used in the reaction.

  The hydrolysis / condensation reaction is preferably carried out by heating with, for example, an oil bath. In the hydrolysis / condensation reaction, the heating temperature is preferably 130 ° C. or lower, more preferably 40 to 100 ° C. The heating time is preferably 0.5 to 12 hours, and more preferably 1 to 8 hours. During heating, the mixture may be stirred or placed under reflux. Moreover, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water after completion | finish of reaction. In this washing, washing with water containing a small amount of salt (for example, an aqueous ammonium nitrate solution of about 0.2% by weight) is preferable in that the washing operation is facilitated. Washing is performed until the aqueous layer after washing becomes neutral, and then the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate or molecular sieve as necessary, and then the solvent is removed to remove the solvent. The polysiloxane can be obtained.

  The polysiloxane preferably has a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC in the range of 100 to 50,000, and more preferably in the range of 200 to 10,000. When the weight average molecular weight of the polysiloxane is in the above range, it is easy to handle when producing a liquid crystal alignment film, and the obtained liquid crystal alignment film has sufficient material strength and characteristics.

[Poly (meth) acrylate]
Poly (meth) acrylate can be obtained, for example, by radical polymerization of a (meth) acrylic compound. Although it does not restrict | limit especially as a (meth) acrylic compound used for a synthesis | combination, For example, unsaturated carboxylic acids, such as (meth) acrylic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, vinyl benzoic acid;
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, trimethoxysilylpropyl (meth) acrylate, methoxyethyl (meth) acrylate, glycidyl (meth) acrylate, 3,4- (meth) acrylic acid 3,4- Epoxy cyclohexyl methyl, (meth) acrylic acid-N, N-dimethylaminoethyl, (meth) acrylic acid methoxypolyethylene glycol, tetrahydrofurfuryl (meth) acrylate, α-methoxy acrylate, α-ethoxy acrylate methyl, croton Methyl acetate, ethyl crotonic acid, Unsaturated carboxylic acid esters such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated polyvalent esters such as maleic anhydride and itaconic anhydride Carboxylic anhydride; etc. are mentioned. As a (meth) acrylic-type compound, the above-mentioned thing can be used individually by 1 type or in combination of 2 or more types.
In the polymerization, another monomer other than the (meth) acrylic compound may be used. For example, poly (meth) acrylate as compound (X) can be obtained by using a compound having a silicon-silicon bond and an ethylenically unsaturated bond as another monomer.

Examples of the polymerization initiator used in the polymerization reaction of the (meth) acrylic compound include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2, Azo compounds such as 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis (t-butylperoxy) cyclohexane, etc. Organic peroxides; hydrogen peroxide; redox type initiators composed of these peroxides and reducing agents. Of these, azo compounds are preferred. A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The use ratio of the polymerization initiator is preferably 0.01 to 50 parts by weight, and more preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of all monomers used in the reaction.

  The polymerization reaction of the (meth) acrylic compound is preferably performed in an organic solvent. Examples of the organic solvent used for the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like. Among these, it is preferable to use at least one selected from the group consisting of alcohol and ether, and examples thereof include diethylene glycol methyl ethyl ether and propylene glycol monomethyl ether acetate. In addition, an organic solvent can be used individually by 1 type or in combination of 2 or more types.

  In the polymerization reaction of the (meth) acrylic compound, the reaction temperature is preferably 30 to 120 ° C, more preferably 60 to 110 ° C. The reaction time is preferably 1 to 36 hours, and more preferably 2 to 24 hours. The amount of organic solvent used (a) is such that the total amount (b) of monomers used in the reaction is 0.1 to 50% by weight with respect to the total amount of reaction solution (a + b). It is preferable to do.

  For poly (meth) acrylate, the polystyrene-equivalent number average molecular weight (Mn) measured by GPC improves the liquid crystal alignment of the liquid crystal alignment film to be formed and ensures the stability of the liquid crystal alignment over time. In view of the above, it is preferably 250 to 500,000, more preferably 500 to 100,000, and still more preferably 1,000 to 50,000.

As a preferred embodiment of the component contained in the liquid crystal aligning agent,
(A) As a polymer component, a polymer having at least one selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, poly (meth) acrylate, and polysiloxane and having no silicon-silicon bond (hereinafter referred to as “polymer component”) (It is also referred to as “other polymer”.) And polysilane as the compound (X).
(B) The aspect containing the polymer which is at least 1 type chosen from the group which consists of polyamic acid, a polyimide, a polyamic acid ester, poly (meth) acrylate, and polysiloxane as a polymer component, and has a silicon-silicon bond.
(C) As a polymer component, a polymer having at least one selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, poly (meth) acrylate, and polysiloxane and having a silicon-silicon bond, and the other And an embodiment containing a polymer.
Is mentioned.

The compounding ratio of compound (X) is preferably selected as appropriate according to the type of compound (X). For example, when using polysilane, it is preferable to set it as 0.01-40 weight part with respect to a total of 100 weight part of the polymer component of a liquid crystal aligning agent. If it is less than 0.01 part by weight, it is difficult to obtain the effect of compounding compound (X). If it exceeds 40 parts by weight, the material strength decreases, and various properties such as liquid crystal orientation and voltage holding ratio decrease. It is because it becomes easy to do. More preferably, it is 0.03-30 weight part, More preferably, it is 0.05-20 weight part, Especially preferably, it is 0.1-15 weight part.
Further, when at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, poly (meth) acrylate and polysiloxane is used as compound (X), the compounding ratio of compound (X) is determined as a polymer component. It can set suitably in the range of 1 to 100 weight% with respect to the total amount. Preferably it is 5 weight% or more, More preferably, it is 10 weight% or more.

In addition, when the liquid crystal aligning agent containing the compound which has a silicon-silicon bond is used, the reason for improving the DC afterimage characteristics and reliability is not clear, but the silicon-silicon bond has conductivity due to sigma conjugation. As shown, leakage of residual charge accumulated by application of DC voltage contributed to the improvement of afterimage, and part of the silicon-silicon bond was decomposed by irradiation with backlight, and the decomposed compound started radicals. As a result of acting like an agent and being taken into the resin, it does not act as an impurity and contributes to the improvement of reliability.
Moreover, the liquid crystal aligning agent containing compound (X) is suitable also as a liquid crystal aligning agent for photo-alignment (mainly photodecomposition type). The reason for this is not necessarily clear, but the compound (X) is decomposed by light irradiation for imparting alignment ability, so that anisotropy appears or disappears, resulting in anisotropy in the polarization direction or a direction perpendicular thereto. It is presumed that a highly characteristic film was formed.

<Other ingredients>
The liquid crystal aligning agent which concerns on this invention may contain the other component as needed. Examples of the other components include compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compound”), functional silane compounds, metal chelate compounds, curing accelerators, surfactants, and the like. Can be mentioned.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Examples of such epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylene diene Amine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diamy Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can be used.
When adding an epoxy group containing compound to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 40 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent. More preferably, it is 30 parts by weight.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When adding a functional silane compound to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 2 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, 0.02- More preferably, it is 0.2 parts by weight.

[Metal chelate compounds]
When the polymer component of the liquid crystal aligning agent has an epoxy structure, the metal chelate compound is a liquid crystal aligning agent (especially liquid crystal alignment for a retardation film) for the purpose of ensuring the mechanical strength of the film formed by low-temperature treatment. Agent). As the metal chelate compound, it is preferable to use an acetylacetone complex or an acetoacetic acid complex of a metal selected from aluminum, titanium and zirconium. Specifically, for example, diisopropoxyethyl acetoacetate aluminum, tris (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, diisopropoxybis (ethylacetoacetate) titanium, diisopropoxybis (acetylacetonate) Examples thereof include titanium, tri-n-butoxyethyl acetoacetate zirconium, and di-n-butoxybis (ethyl acetoacetate) zirconium.
When the metal chelate compound is added, the use ratio thereof is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight, with respect to 100 parts by weight of the total components including the epoxy structure. Preferably it is 1-30 weight part.

[Curing accelerator]
When the polymer component in the liquid crystal aligning agent has an epoxy structure, the curing accelerator is liquid crystal alignment in order to ensure the mechanical strength of the liquid crystal alignment film to be formed and the stability over time of the liquid crystal alignment. Contained in an agent (particularly, a liquid crystal aligning agent for a retardation film). As the curing accelerator, for example, a compound having a phenol group, silanol group, thiol group, phosphoric acid group, sulfonic acid group, carboxyl group, carboxylic anhydride group or the like can be used. The compound which has is preferable. Specific examples thereof include compounds having a phenol group such as cyanophenol, nitrophenol, methoxyphenoxyphenol, thiophenoxyphenol, 4-benzylphenol; compounds having a silanol group such as trimethylsilanol, triethylsilanol, 1 , 4-bis (hydroxydimethylsilyl) benzene, triphenylsilanol, diphenylsilanediol and the like. When the curing accelerator is added, the use ratio thereof is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of the total components including the epoxy structure, and further Preferably it is 1-30 weight part.

[Surfactant]
The surfactant can be contained in a liquid crystal aligning agent (particularly, a liquid crystal aligning agent for a retardation film) for the purpose of improving the applicability of the liquid crystal aligning agent to the substrate. Examples of such surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, polyalkylene oxide surfactants, and fluorine-containing surfactants. be able to. The proportion of the surfactant used is preferably 10 parts by weight or less, and more preferably 1 part by weight or less with respect to 100 parts by weight of the total amount of the liquid crystal aligning agent.
In addition to the above, other components include compounds having at least one oxetanyl group in the molecule, antioxidants, and the like.

<Solvent>
The liquid crystal aligning agent according to the present invention is prepared as a liquid composition in which compound (X) and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent.

  Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether , Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Recall diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. be able to. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent is applied to the substrate surface as will be described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when the solid content concentration is less than 1% by weight, 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 solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

  The particularly preferable solid content concentration range varies depending on the use of the liquid crystal aligning agent and the method used when the liquid crystal aligning agent is applied to the substrate. For example, when a liquid crystal aligning agent for a liquid crystal display element is applied to a substrate by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) Is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50 ° C, more preferably 20 to 30 ° C. Moreover, about the liquid crystal aligning agent for retardation films, the solid content density | concentration of a liquid crystal aligning agent is 0.2 to 10 weight% from a viewpoint which makes the applicability | paintability of a liquid crystal aligning agent, and the film thickness of the coating film formed moderate. It is preferable that it is the range of 3-10 weight%.

<Liquid crystal display element and retardation film>
A liquid crystal alignment film can be manufactured by using the liquid crystal aligning agent described above. Moreover, the liquid crystal aligning film formed using the said liquid crystal aligning agent can be preferably applied to the liquid crystal aligning film for liquid crystal display elements (for liquid crystal cells), and the liquid crystal aligning film for retardation films. Below, a liquid crystal display element and retardation film are demonstrated.

[Liquid crystal display element]
The liquid crystal display element according to the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The operation mode of the liquid crystal display element is not particularly limited. For example, various operation modes such as a TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. Can be applied to.

  A liquid crystal display element can be manufactured by the process including the following processes (1-1)-(1-3), for example. In the step (1-1), the substrate to be used differs depending on the desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): Formation of coating film]
First, a liquid crystal aligning agent is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1A) When manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, for example, first, a pair of two substrates on which patterned transparent conductive films are provided, and each transparent conductive film is formed. A liquid crystal aligning agent is preferably applied onto the surface by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, after forming a transparent conductive film without a pattern, a method of forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming a transparent conductive film; And so on. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

  After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-1B) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. A liquid crystal aligning agent is apply | coated to one surface of the counter substrate which is not formed, respectively, Then, each coating surface is heated, and a coating film is formed. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1A) and (1-1B), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a liquid crystal alignment film. The At this time, when at least one of polyamic acid, polyamic acid ester and polyimide is blended in the liquid crystal aligning agent, the polyamic acid and polyamic acid blended in the liquid crystal aligning agent are further heated after the coating film is formed. It is good also as a coating film made more imidized by advancing the dehydration ring-closing reaction of ester and polyimide.

[Step (1-2): Orientation ability imparting treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process which provides liquid crystal aligning ability to the coating film formed at the said process (1-1) is implemented. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the orientation-imparting treatment include rubbing treatment in which the coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment in which the coating film is irradiated with polarized or non-polarized radiation. Processing. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1-1) can be used as it is as a liquid crystal alignment film. May be.

In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as radiation applied to the coating film, for example. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When non-polarized radiation is irradiated, the irradiation direction is an oblique direction.
As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. Ultraviolet rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . Moreover, you may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC, More preferably, it is 50-150 degreeC.

  In addition, the liquid crystal alignment film after the rubbing treatment is further subjected to a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays or a surface of the liquid crystal alignment film. A resist film is formed on the part, and a rubbing process is performed in a direction different from the previous rubbing process, followed by a process of removing the resist film, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. . In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged opposite to each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped to a predetermined location on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. can do. Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal. It is desirable to do.

As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  And a liquid crystal display element can be obtained by sticking a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

[Phase difference film]
Next, a method for producing a retardation film using a liquid crystal aligning agent will be described. In the production of the retardation film, it is possible to form a uniform liquid crystal alignment film while suppressing the generation of dust and static electricity during the process, and by using a suitable photomask during radiation irradiation, the substrate It is preferable to use a photo-alignment method in that a plurality of regions having different liquid crystal alignment directions can be formed arbitrarily. Specifically, it can be produced through the following steps (2-1) to (2-3).

[Step (2-1): Formation of coating film by liquid crystal aligning agent]
First, a liquid crystal aligning agent is apply | coated on a board | substrate and a coating film is formed. As the substrate used here, a transparent substrate made of a synthetic resin such as triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, etc. is preferably exemplified. Can do. Of these, TAC is generally used as a protective layer for a polarizing film in a liquid crystal display device. In addition, polymethyl methacrylate can be preferably used as a substrate for a retardation film in that the hygroscopicity of the solvent is low, the optical properties are good, and the cost is low. In addition, for the substrate used for the application of the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the coating film, a conventionally known pretreatment is performed on the surface of the substrate surface on which the coating film is formed. May be implemented.

  In many cases, the retardation film is used in combination with a polarizing film. At this time, it is necessary to attach the retardation film by precisely controlling the angle with respect to the polarization axis of the polarizing film in a specific direction so that the desired optical characteristics can be exhibited. Accordingly, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction on a substrate such as a TAC film or polymethyl methacrylate, the angle of the retardation film is controlled on the polarizing film. The step of bonding can be omitted. Thereby, it can contribute to the improvement of productivity of a liquid crystal display element. In order to form a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction, it is preferable to carry out by a photo-alignment method using a liquid crystal alignment agent.

The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, an ink jet method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber. Doctor coater method, offset gravure coater method, single roll kiss coater method, reverse kiss coater method using small diameter gravure roll, 3 reverse roll coater method, 4 reverse roll coater method, slot die method, air doctor coater method A positive rotation roll coater method, a blade coater method, a knife coater method, an impregnation coater method, an MB coater method, an MB reverse coater method, and the like can be employed.
After coating, the coated surface is heated (baked) to form a coating film. The heating temperature at this time is preferably 40 to 150 ° C, more preferably 80 to 140 ° C. The heating time is preferably 0.1 to 15 minutes, and more preferably 1 to 10 minutes. The film thickness of the coating film formed on the substrate is preferably 1 to 1,000 nm, more preferably 5 nm to 500 nm.

[Step (2-2): Light irradiation step]
Next, the coating film formed on the substrate as described above is irradiated with light, thereby imparting liquid crystal alignment ability to the liquid crystal alignment film. Here, examples of the light to be irradiated include ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm. Among these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. Irradiation light may be polarized or non-polarized. As the polarized light, it is preferable to use light including linearly polarized light.
When the light to be used is polarized light, the light irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized light, it is necessary to carry out from a direction oblique to the substrate surface.
Examples of the light source used include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and a mercury-xenon lamp (Hg-Xe lamp). Polarized light can be obtained by means of using these light sources together with, for example, a filter or a diffraction grating.
The dose of light is preferably less than 0.1 mJ / cm ² or more 1,000 mJ / cm ^2, more preferably to 1 to 500 mJ / cm ^2, further be 2~200mJ / cm ² preferable.

[Step (2-3): Formation of Liquid Crystal Layer]
Next, a polymerizable liquid crystal is applied and cured on the coating film after the light irradiation as described above. Thereby, the coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or a liquid crystal composition that is polymerized by at least one treatment of heating and light irradiation. As such a polymerizable liquid crystal, a conventionally known liquid crystal can be used. Specifically, for example, Non-Patent Document 1 ("UV curable liquid crystal and its application", Liquid Crystal, Vol. 3, No. 1 (1999). Year), pp 34-42). Further, cholesteric liquid crystal; discotic liquid crystal; twisted nematic alignment type liquid crystal to which a chiral agent is added may be used. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may further be a composition containing a known polymerization initiator, an appropriate solvent, and the like.
In order to apply the polymerizable liquid crystal as described above on the formed liquid crystal alignment film, for example, an appropriate application method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an ink jet method can be employed. .

Next, the coating film of the polymerizable liquid crystal formed as described above is subjected to at least one treatment selected from heating and light irradiation to cure the coating film to form a liquid crystal layer. It is preferable to perform these treatments in a superimposed manner because good alignment can be obtained.
The heating temperature of the coating film is appropriately selected depending on the type of polymerizable liquid crystal used. For example, when using RMS03-013C manufactured by Merck, it is preferable to heat at a temperature in the range of 40 to 80 ° C. The heating time is preferably 0.5 to 5 minutes.
As irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used. The irradiation dose of light, preferably in the 50~10,000mJ / cm ^2, and more preferably a 100~5,000mJ / cm ^2.
The thickness of the liquid crystal layer to be formed is appropriately set depending on desired optical characteristics. For example, when manufacturing a half-wave plate for visible light having a wavelength of 540 nm, a thickness is selected such that the retardation of the formed retardation film is 240 to 300 nm. The thickness is selected such that the phase difference is 120 to 150 nm. The thickness of the liquid crystal layer from which the desired retardation is obtained varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, when RMS03-013C manufactured by Merck is used, the thickness for manufacturing a quarter-wave plate is in the range of 0.6 to 1.5 μm.

  The retardation film obtained as described above can be preferably applied as a retardation film of a liquid crystal display element. The liquid crystal display element to which the retardation film manufactured using the liquid crystal aligning agent of the present invention is applied is not limited in its operation mode. For example, TN type, STN type, IPS type, FFS type, VA type and the like are known. It can be applied to various modes. The retardation film is used by attaching the substrate-side surface of the retardation film to the outer surface of the polarizing plate disposed on the viewing side of the liquid crystal display element. Therefore, it is preferable that the retardation film substrate is made of TAC or an acrylic base, and the retardation film substrate also functions as a protective film for the polarizing film.

  Here, there is a roll-to-roll method as a method for producing a retardation film on an industrial scale. In this method, a film is unwound from a wound body of a long base film, a liquid crystal alignment film is formed on the unwound film, and a polymerizable liquid crystal is applied and cured on the liquid crystal alignment film. It is the method of performing the process and the process which laminates | stacks a protective film as needed in the continuous process, and collect | recovering the film after passing through these processes as a wound body. The retardation film formed using the liquid crystal aligning agent according to the present invention has good adhesion to the substrate, and the liquid crystal alignment film and the substrate are hardly peeled even when stored as a wound body. Therefore, it is possible to suppress a decrease in product yield when producing a retardation film by a roll-to-roll method, which is preferable from the viewpoint of productivity.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, The present invention can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following synthesis examples, the polymer weight average molecular weight Mw, imidization rate and epoxy equivalent, and the solution viscosity of the polymer solution were measured by the following methods. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Weight average molecular weight Mw and number average molecular weight Mn of the polymer]
Mw and Mn are polystyrene equivalent values measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidation rate of polymer]
A solution containing polyimide is poured into pure water, and the resulting precipitate is sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR is measured at room temperature using tetramethylsilane as a reference substance. did. From the obtained ¹ H-NMR spectrum, the imidation ratio was determined using the following mathematical formula (1).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
[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.

<Synthesis of compounds>
[Synthesis Example 1-1; Synthesis of Compound (DA-1)]
Compound (DA-1) was synthesized according to the following scheme 1.

<Synthesis of polymer>
[Synthesis Example 2-1; Synthesis of Polymer (PA-1)]
10.36 g of pyromellitic dianhydride as the tetracarboxylic dianhydride (93 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and bis [2- (4-aminophenyl) ethyl as the diamine 19.6 g (100 mol parts) of hexanedioic acid was dissolved in a mixed solvent of 85 g of N-methyl-2-pyrrolidone (NMP) and 85 g of γ-butyrolactone (GBL) and reacted at 30 ° C. for 6 hours. . The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain 29.1 g of polyamic acid (polymer (PA-1)). The obtained polymer (PA-1) was prepared to have a solvent composition of NMP: GBL = 50: 50 (weight ratio) to be 15% by weight, and the viscosity of this solution was measured to be 671 mPa · s. It was. Further, when this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis Example 2-2 to Synthesis Example 2-4]
A polyamic acid was obtained in the same manner as in Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used in the reaction were changed as shown in Table 1 below. In addition, the numerical value of Table 1 shows the use ratio (mol%) with respect to the whole quantity of the tetracarboxylic dianhydride used for reaction about the tetracarboxylic dianhydride, About the diamine, the diamine used for reaction The ratio of use (mol%) to the total amount of is shown. When each of the polymer solutions obtained in each synthesis example was allowed to stand at 20 ° C. for 3 days, none of them was gelled and the storage stability was good.

Abbreviations of tetracarboxylic dianhydride and diamine in Table 1 are as follows.
(Tetracarboxylic dianhydride)
AN-1; 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; pyromellitic dianhydride AN-3; 2,3,5-tricarboxycyclopentylacetic dianhydride AN-4; 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione AN-5; 5- (2,5 -Dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione AN-6; bicyclo [3.3.0] Octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine)
DA-1; Compound DA-2 represented by the above formula (DA-1); paraphenylenediamine DA-3; 4,4′-diaminodiphenylmethane DA-4; 1,5-bis (4-aminophenoxy) pentane DA-5; bis [2- (4-aminophenyl) ethyl] hexanedioic acid DA-6; 4,4′-diaminodiphenylamine DA-7; 3,5-diaminobenzoic acid DA-8; N- (2, 4-diaminophenyl) -4- (4-heptylcyclohexyl) benzamide DA-9; 4- (tetradecoxy) benzene-1,3-diamine DA-10; cholestanyl 3,5-diaminobenzoate Polymer ( PA-2) is suitable for a TN liquid crystal display element, and the polymer (PA-3) is suitable for a VA liquid crystal display element.

[Synthesis Example 3-1; Synthesis of Polymer (PI-1)]
21.48 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride (98 mol parts with respect to 100 mol parts of the total amount of diamine used in the synthesis), and 3,5 as diamine -Dissolve 5.95 g (40 mol parts) of diaminobenzoic acid and 22.56 g (60 mol parts) of bis [2- (4-aminophenyl) ethyl] hexanedioic acid in 200 g of NMP, and react at room temperature for 6 hours. went. Next, 250 g of NMP was added, 15.2 g of pyridine and 19.6 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 100 ° C. for 5 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol, and then dried at 40 ° C. under reduced pressure for 15 hours to obtain a polyimide (polymer (PI-1)) having an imidation ratio of about 75%. The obtained polymer (PI-1) was prepared to be 15% by weight with NMP. When the viscosity of this solution was measured, it was 841 mPa · s.

[Synthesis Example 4-1; Synthesis of Polymer (PAE-1)]
As tetracarboxylic dianhydride, 8.47 g (30 mmol) of a compound represented by the following formula (AN-7) and 17.2 g (66 mmol) of a compound represented by the following formula (AN-8) were dissolved in 684 g of NMP. Further, 5.06 g (50 mmol) of triethylamine and 25.8 g (100 mmol) of a compound represented by the following formula (DA-11) were added and dissolved. Next, while stirring this solution, 83.0 g (300 mmol) of triazine condensing agent DMT-MM (15 ± 2% by weight hydrate) was added, 122 g of NMP was further added, and the mixture was stirred at room temperature for 5 hours to be polyamic acid ester. A solution of (polymer (PAE-1)) was obtained. It was 32.3 mPa * s when the viscosity of the obtained polymer solution was measured.
Next, the polymer solution was put into 5,676 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 100 ° C. to obtain a polymer (PAE-1) powder. The recovered polymer (PAE-1) was prepared to be 15% by weight with NMP. It was 251 mPa * s when the viscosity of this solution was measured.

なお、式（Ｘ−１）中、Ｐｈはフェニル基、Ｍｅはメチル基を示す（以下同じ）。 <Preparation and evaluation of liquid crystal aligning agent>
[Example 1-1: rubbing alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent 100 parts by weight of the polymer (PA-1) obtained in Synthesis Example 2-1 as a polymer and polyphenylmethylsilane having a number average molecular weight of 2,000 (the following formula (X-1) 5 parts by weight of a compound having a structural unit represented by the following formula: a mixed solvent (GBL: NMP: BC = 40: 40:20 (weight ratio)) to obtain a solution having a solid concentration of 3.5% by weight. The liquid crystal aligning agent (R-1) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm. In addition, the number average molecular weight of polysilane is a polystyrene conversion value (hereinafter the same).

In the formula (X-1), Ph represents a phenyl group, and Me represents a methyl group (hereinafter the same).

(2) Evaluation of applicability The liquid crystal aligning agent (R-1) prepared above was applied on a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) in a substituted 200 ° C. oven for 1 hour. This coating film was observed with a microscope having a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. Evaluation is that the film thickness unevenness and the pinhole are not observed even when observed with a 100 × microscope, the coating property is “good”, and the 100 × microscope observes at least one of the film thickness unevenness and the pinhole. However, when both the film thickness unevenness and the pinhole were not observed with a 10 × microscope, the coating property was “OK”. At least one of the film thickness unevenness and the pinhole was clearly observed with a 10 × microscope. The case was evaluated as “bad” coating property. In this example, neither film thickness unevenness nor pinhole was observed even with a 100 × microscope, and the coating property was “good”.

(3) Evaluation of rubbing resistance With respect to the coating film obtained above, a rubbing machine having a roll wound with a cotton cloth was used to rotate the roll at 1,000 rpm, the stage moving speed 20 cm / sec, and the indentation length 0.4 mm. The rubbing treatment was performed 7 times. Foreign matter (a piece of coating film) due to rubbing scraping on the obtained substrate was observed with an optical microscope, and the number of foreign matters in a 500 μm × 500 μm region was measured. In the evaluation, the rubbing resistance was “good” when the number of foreign matters was 3 or less, and the rubbing resistance was “good” when 4 or more and 7 or less were present, and the rubbing resistance “bad” when 8 or more. As a result, no foreign matter was confirmed, and the rubbing resistance of this coating film was “good”.

(4) Manufacture of FFS type liquid crystal display element by rubbing process The FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The liquid crystal aligning agent (R-1) prepared in the above (1) is paired with the opposite glass substrate 11b not provided with the glass substrate 11a, and the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b. The coating film was formed by coating using a spinner. Next, this coating film was pre-baked for 1 minute on an 80 ° C. hot plate, and then heated (post-baked) for 15 minutes at 230 ° C. in an oven in which the inside of the chamber was purged with nitrogen, so that the average film thickness was 0.1 μm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. Further, as the top electrode 13, four types of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 3 shows the configuration of the drive electrode used. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four drive electrodes, and each of the four drive electrode regions serves as a pixel region.

  Subsequently, the surface of the coating film formed on the glass substrates 11 a and 11 b was rubbed with cotton to form the liquid crystal alignment film 12. In FIG.2 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11a is shown by the arrow. Next, after applying a sealant to the outer edge of the surface having the liquid crystal alignment film in one of the pair of substrates, the rubbing directions of the substrates 11a and 11b are antiparallel to each other. The sealing agent was cured by bonding through a spacer having a diameter of 3.5 μm. Next, liquid crystal MLC-6221 (manufactured by Merck & Co., Inc.) was injected between the pair of substrates through the liquid crystal injection port to form the liquid crystal layer 16. Furthermore, the liquid crystal display element 10 was produced by bonding a polarizing plate (not shown) on both outer surfaces of the substrates 11a and 11b so that the polarization directions of the two polarizing plates were orthogonal to each other.

(5) Evaluation of liquid crystal orientation For the FFS type liquid crystal display device manufactured as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with a microscope at a magnification of 50 times. did. The evaluation was performed when the abnormal domain was not observed and the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. In this liquid crystal display element, the liquid crystal orientation was “good”.
(6) Evaluation of voltage holding ratio For the FFS type liquid crystal display device manufactured as described above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the release of application. When the voltage holding ratio (VHR) of was measured, it was 99.3%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

(7) per FFS type liquid crystal display device manufactured in heat-resistant above, the (6) and measure the voltage holding ratio similarly to the value as the initial VHR _{(VHR BF).} Next, the liquid crystal display element after the initial VHR measurement was left in an oven at 100 ° C. for 500 hours. Thereafter, the liquid crystal display element was left at room temperature and allowed to cool to room temperature, and then the voltage holding ratio (VHR _AF ) was measured in the same manner as in the above (6). Further, the rate of change in voltage holding ratio (ΔVHR (%)) before and after application of thermal stress was determined by the following mathematical formula (EX-2).
ΔVHR = ((VHR _BF −VHR _AF ) ÷ VHR _BF ) × 100 (EX−2)
Evaluation of heat resistance is “good” when the rate of change ΔVHR is less than 4%, “good” when 4% or more and less than 5%, and “high” when 5% or more. Went as "bad". As a result, ΔVHR of the liquid crystal display element of this example was 1.0%, and the heat resistance was “good”.
(8) per FFS type liquid crystal display device manufactured in light resistance above, to measure the voltage holding ratio similarly to the above (6), and its value as an initial VHR _{(VHR BF).} Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an 80 ° C. oven under LED lamp irradiation for 200 hours, and then allowed to stand at room temperature and naturally cooled to room temperature. With respect to the liquid crystal cell after light irradiation, the voltage holding ratio was measured again by the same method as described above. This value was defined as a voltage holding ratio (VHR _AFBL ) after light irradiation. The decrease amount ΔVHR _BL (%) of the voltage holding ratio was obtained from the following formula (EX-3), and the light resistance was evaluated.
ΔVHR _BL = ((VHR _BF −VHR _AFBL ) ÷ VHR _BF ) × 100 (EX-3)
When ΔVHR _BL is less than 3.0%, light resistance is “good”, when it is 3.0% or more and less than 5.0%, “good”, when it is 5.0% or more, “bad” I decided. As a result, ΔVHR _BL of the liquid crystal display element of this example was 1.0%, and the light resistance was “good”.

(9) Evaluation of afterimage characteristics (DC afterimage evaluation)
The FFS type liquid crystal display device produced above was placed in an environment of 25 ° C. and 1 atmosphere. The bottom electrode was set as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). The electrode B and the electrode D were short-circuited with the common electrode to be in a 0 V application state, and a composite voltage composed of an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours. Immediately after 2 hours, an AC voltage of 1.5 V was applied to all of the electrodes A to D. Then, from the start of applying an AC voltage of 1.5 V to all drive electrodes, a drive stress application region (pixel region of electrode A and electrode C) and a drive stress non-application region (pixel region of electrode B and electrode D) The time until the difference in brightness with the eye cannot be confirmed visually was measured, and this was defined as the afterimage erasing time Ts. Note that the shorter this time, the less likely an afterimage is generated. When the afterimage erasing time Ts was less than 30 seconds, it was evaluated as “good”, when it was between 30 seconds and less than 120 seconds as “good”, and when it was over 120 seconds as “bad”, this implementation The afterimage erasing time Ts of the example liquid crystal display element was 1 second, and the afterimage characteristics were evaluated as “good”.

[Example 1-2 to Examples 1-6 and Comparative Examples 1 and 2]
In Example 1-1, a liquid crystal aligning agent was prepared in the same manner as in Example 1-1 except that the types and amounts of the polymers and additives used were as shown in Table 2 below, and an FFS type liquid crystal was prepared. The display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below.

表２中、添加剤の数値は、液晶配向剤の調製に使用した重合体成分の合計１００重量部に対する配合割合（重量部）を示す。 Abbreviations of additives in Table 2 are as follows.
(Additive)
X-1; polyphenylmethylsilane (number average molecular weight 2,000)
X-2; diphenylsilane-phenylsilin copolymer (a compound having a number average molecular weight of 5,000 and a structural unit represented by the following formula (X-2))
X-3: Diphenylsilane-methylsilin copolymer (a compound having a number average molecular weight of 600 and a structural unit represented by the following formula (X-3))
X-4: Cyclic polysilane represented by the following formula (X-4) (number average molecular weight 450)
X-5; Methylphenylsilane-diphenylsilane copolymer (number average molecular weight 10,000, compound having a structural unit represented by the following formula (X-5))
X-6; Compound EP-1 having a structural unit represented by the following formula (X-6); 4,4′-methylenebis [N, N-bis (oxiranylmethyl) aniline]

In Table 2, the numerical value of the additive indicates the blending ratio (parts by weight) with respect to 100 parts by weight of the polymer components used for the preparation of the liquid crystal aligning agent.

As shown in Table 2, in Examples 1-1 to 1-6, the coating property of the liquid crystal aligning agent, the rubbing resistance of the coating film, the liquid crystal alignment property of the liquid crystal display element, the voltage holding ratio, the heat resistance, and the light resistance. Each of the characteristics and the afterimage characteristics was “good” or “good”, and various characteristics were balanced. In particular, Examples 1-1 to 1-3 and Example 1-6 obtained “good” results in any evaluation.
On the other hand, in the comparative example 1, although applicability | paintability, rubbing tolerance, and liquid crystal orientation were evaluation of "good", it was a result in which a voltage holding rate, heat resistance, and light resistance are all inferior to an Example. In Comparative Example 2, the afterimage characteristics were inferior to those of the Examples.

[Example 2-1: Photo-alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent As a polymer, 100 parts by weight of the polymer (PA-4) obtained in Synthesis Example 2-4 was mixed with γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve. It was dissolved in a mixed solvent consisting of (BC) (GBL: NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content concentration of 3.5% by weight. A liquid crystal aligning agent (R-6) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-6) prepared above was applied on a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) in a substituted 200 ° C. oven for 1 hour. The coatability of this coating film was evaluated in the same manner as in Example 1-1 (2). As a result, the coating property was “good”.
(3) Evaluation of orientation The coating film obtained above was irradiated with polarized ultraviolet rays 300 J / m ² containing a 313 nm emission line from the normal direction of the substrate using an Hg-Xe lamp and a Grand Taylor prism, and subjected to an orientation treatment. Was given. The refractive index anisotropy (nm) of this glass substrate with an alignment film was measured using a liquid crystal alignment film inspection apparatus (RayScan) manufactured by MORITEX. In the evaluation, the orientation was “good” when it was 0.020 nm or more, “good” when it was less than 0.020 nm and less than 0.010 nm, and “bad” when it was less than 0.010 nm. As a result, this substrate was 0.034 nm and the orientation was “good”.

(4) Manufacture of FFS type liquid crystal display element by photo-alignment method First, the liquid crystal prepared in (1) above on each surface of a pair of glass substrates 11a and 11b similar to (4) in Example 1-1. The orientation agent (R-6) was applied using a spinner to form a coating film. Next, this coating film was pre-baked for 1 minute on an 80 ° C. hot plate, and then heated (post-baked) for 15 minutes at 230 ° C. in an oven in which the inside of the chamber was purged with nitrogen, so that the average film thickness was 0.1 μm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 4A is a top view of the top electrode 13, and FIG. 4B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 4A. In this example, a substrate having a top electrode having an electrode line width d1 of 4 μm and a distance d2 between the electrodes of 6 μm was used. As the top electrode 13, four drive electrodes of electrode A, electrode B, electrode C, and electrode D were used as in (4) of Example 1-1 (see FIG. 3).
Next, each surface of these coatings is irradiated with polarized ultraviolet rays 300 J / m ² including a 313 nm emission line from the substrate normal direction using a Hg-Xe lamp and a Grand Taylor prism, respectively, to have a liquid crystal alignment film. A pair of substrates was obtained. At this time, the irradiation direction of the polarized ultraviolet ray is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of the polarized ultraviolet ray is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface of the substrate having the liquid crystal alignment film by screen printing, and the liquid crystal alignment film surfaces of the pair of substrates are then applied. It was made to oppose and it piled up and crimped | bonded so that the direction which the polarization plane of polarized ultraviolet rays projected on the board | substrate might become parallel, and the adhesive was thermoset at 150 degreeC over 1 hour. Next, liquid crystal “MLC-6221” manufactured by Merck Co., Ltd. was filled into the substrate gap from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature.
Next, an FFS type liquid crystal display element was manufactured by laminating polarizing plates on both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.

(5) Evaluation of liquid crystal orientation About the photo-alignment FFS type liquid crystal display element manufactured above, liquid crystal orientation was evaluated similarly to (5) of the said Example 1-1. As a result, this liquid crystal display element had “good” liquid crystal alignment.
(6) Evaluation of voltage holding ratio With respect to the photo-alignment type FFS liquid crystal display device manufactured as described above, the voltage holding ratio (VHR) was measured in the same manner as (6) of Example 1-1 to evaluate the voltage holding ratio. . As a result, VHR was 99.4%.
(7) Heat resistance The voltage holding ratio (VHR _BF ) is measured in the same manner as (7) of Example 1-1 above, and the heat resistance of the liquid crystal display element is determined by the rate of change of the voltage holding ratio before and after applying thermal stress. evaluated. As a result, ΔVHR was 2.3%, and the heat resistance was judged as “good”.
(8) Light resistance The voltage holding ratio (VHR _BF ) is measured in the same manner as (8) in Example 1-1, and the light resistance of the liquid crystal display element is evaluated by the change in the voltage holding ratio before and after applying light stress. did. As a result, ΔVHR _BL was 2.6%, and the light resistance was judged as “good”.
(9) Evaluation of afterimage characteristics (DC afterimage evaluation)
With respect to the photo-alignment type FFS liquid crystal display device manufactured as described above, the afterimage characteristics were evaluated in the same manner as in Example 1-1 (9). As a result, the afterimage erasing time Ts was 2 seconds, and the afterimage characteristic was evaluated as “good”.

[Example 3-1: retardation film]
(1) Preparation of liquid crystal aligning agent 100 parts by weight of the polymer (PI-1) obtained in Synthesis Example 3-1 and 10 parts by weight of polyphenylmethylsilane having a number average molecular weight of 1,000 were mixed with propylene glycol monomethyl ether acetate. (PGMEA), methyl ethyl ketone (MEK) and butyl acetate (BTLAC) dissolved in a mixed solvent (PGMEA: MEK: BTLAC = 20: 10: 70 (weight ratio)) and a solid content concentration of 5.0% by weight It was. A liquid crystal aligning agent (R-7) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.
(2) Production of retardation film The liquid crystal aligning agent (R-7) prepared above is applied to one side of a TAC film as a substrate with a bar coater, and baked in an oven at 120 ° C for 2 minutes to form a film. A coating film having a thickness of 100 nm was formed. Next, the surface of the coating film was irradiated perpendicularly from the substrate normal line with polarized ultraviolet rays of 10 mJ / cm ² containing an emission line of 313 nm using a Hg—Xe lamp and a Grand Taylor prism. Next, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck & Co., Inc.) was filtered through a filter having a pore size of 0.2 μm, and this polymerizable liquid crystal was applied onto the coated film after light irradiation by a bar coater. A coating film was formed. After baking for 1 minute in an oven adjusted to a temperature of 50 ° C., an unpolarized ultraviolet ray containing 365 nm emission line was irradiated at 1,000 mJ / cm ² from a direction perpendicular to the coating surface using an Hg-Xe lamp. A retardation film was produced by curing a polymerizable liquid crystal to form a liquid crystal layer.

(3) Evaluation of liquid crystal orientation About the retardation film manufactured by said (2), liquid crystal orientation is observed by observing the presence or absence of an abnormal domain by visual observation under crossed Nicols and a polarizing microscope (magnification 2.5 times). evaluated. The evaluation was that the alignment was good visually and the abnormal domain was not observed with a polarizing microscope. The liquid crystal orientation was “good”. The case where the liquid crystal orientation was “possible”, and the case where an abnormal domain was observed visually and with a polarizing microscope was regarded as “Poor”. As a result, this retardation film was evaluated as “good” for liquid crystal alignment.

(4) Adhesiveness Using the retardation film produced in (2) above, the adhesiveness of the coating film formed with the liquid crystal aligning agent to the substrate was evaluated. First, using an equally spaced spacer with a guide, a cutter knife was used to cut from the surface on the liquid crystal layer side of the retardation film to form 10 × 10 lattice patterns within a range of 1 cm × 1 cm. The depth of each cut was made to reach the middle of the substrate thickness from the surface of the liquid crystal layer. Next, after attaching a cellophane tape so as to cover the entire surface of the lattice pattern, the cellophane tape was peeled off. The notches in the lattice pattern after peeling were observed visually under crossed Nicols to evaluate the adhesion. The evaluation was that the adhesion was “good” when no peeling was observed at the portion along the cut line and at the intersection of the lattice pattern, and the number of lattices where peeling was observed in the above portion was the number of the entire lattice pattern. On the other hand, when the amount is less than 15%, the adhesion is “possible”, and when the number of lattices where peeling is observed in the above portion is 15% or more with respect to the total number of lattice patterns, the adhesion is “bad”. went. As a result, this retardation film had good adhesion.
(5) Adhesion reliability The retardation film produced in the above (2) is exposed to a high temperature and humidity atmosphere of 85 ° C. and 85% RH for 24 hours, and then the same operation as in the above (4) is performed. Sex was evaluated. Evaluation is that the adhesion reliability is “good” when no separation is confirmed at the portion along the cut line and at the intersection of the lattice pattern, and the number of lattices where separation is observed in the above portion is the number of the entire lattice pattern On the other hand, the case where it was less than 25% was evaluated as “possible”, and the case where the number of lattices where peeling was observed in the above portion was 25% or more with respect to the total number of lattice patterns was regarded as “defective”. As a result, this retardation film had good adhesion reliability “good”.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal aligning film, 13 ... Top electrode, 14 ... Insulating layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer

Claims (14)

  Liquid crystal aligning agent containing the compound (X) which has a silicon-silicon bond.   The liquid crystal aligning agent according to claim 1, wherein at least one silicon atom constituting the silicon-silicon bond is bonded to an aromatic ring. The said compound (X) is a liquid crystal aligning agent of Claim 2 which has a partial structure represented by a following formula (1-1).

(In Formula (1-1), R ²¹ is a monovalent aromatic ring group which may have a substituent in the ring portion, and R ¹² is a monovalent organic group. “*” Represents a bond. Represents a hand, but at least one of the two “*” is bonded to a silicon atom.) 4. The liquid crystal aligning agent according to claim 3, wherein, in the formula (1-1), R ²¹ is a monovalent aromatic ring group having a substituent in the ring portion.   5. The polymer according to claim 1, further comprising at least one polymer selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, poly (meth) acrylate, and polysiloxane and having no silicon-silicon bond. The liquid crystal aligning agent as described in any one.   The compound (X) contains at least one polymer selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, poly (meth) acrylate and polysiloxane, according to any one of claims 1 to 5. The liquid crystal aligning agent of description. The polymer is at least one selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester,
Bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2 , 3,5-Tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1, 3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] The group consisting of octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride, and pyromellitic dianhydride At least one kind of TE It is a polymer having a partial structure derived from a Rakarubon dianhydride, liquid crystal alignment agent according to claim 5 or 6.   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-7.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-7 to a board | substrate, forming a coating film, and irradiating light to this coating film.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-7 to a board | substrate, and carrying out a rubbing process.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-7 on a board | substrate, and forming a coating film, and the process of irradiating light to this coating film and providing liquid crystal aligning ability is included. A method for producing a liquid crystal alignment film.   A liquid crystal display element provided with the liquid crystal aligning film as described in any one of Claims 8-10.   A retardation film comprising the liquid crystal alignment film according to claim 8.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-7 on a board | substrate, forming the coating film, the process of irradiating the said coating film, and the coating film after the said light irradiation A method for producing a retardation film, comprising: applying a polymerizable liquid crystal thereon and curing the liquid crystal.

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