KR102527238B1 - Liquid crystal aligning agent, liquid crystal aligning film, liquid crystal element, and manufacturing method of liquid crystal element - Google Patents

Abstract

식 (1) 중, R¹∼R⁶은, 각각 독립적으로, 수소 원자 또는 탄소수 1∼20의 1가의 유기기이다. 단, R¹∼R⁶ 중 적어도 1개는, 가교성기를 갖는 1가의 유기기이다. n은 1∼18의 정수이다. n이 2 이상인 경우, 복수의 R¹은 서로 동일해도 상이해도 좋고, 복수의 R²는 서로 동일해도 상이해도 좋다.The polymer component and the cyclic siloxane compound [A] having a crosslinkable group are contained in the liquid crystal aligning agent. One aspect of the cyclic siloxane compound [A] is a compound represented by formula (1).

In Formula (1), R ¹ to ^{R 6} are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. However, at least one of R ¹ to R ⁶ is a monovalent organic group having a crosslinkable group. n is an integer of 1 to 18; When n is 2 or more, a plurality of R ^{1 '} s may be the same as or different from each other, and a plurality of R ² 's may be the same as or different from each other.

Description

Liquid crystal aligning agent, liquid crystal aligning film, liquid crystal element, and manufacturing method of liquid crystal element

(Cross Reference to Related Applications)

This application is based on Japanese Patent Application No. 2018-157299 filed on August 24, 2018, the contents of which are incorporated herein.

This indication relates to the manufacturing method of a liquid crystal aligning agent, a liquid crystal aligning film, a liquid crystal element, and a liquid crystal element.

The liquid crystal element is provided with a liquid crystal alignment film having a function of orienting liquid crystal molecules in a liquid crystal layer in a certain direction. A liquid crystal aligning film is generally formed on a board|substrate by apply|coating to the board|substrate surface the liquid crystal aligning agent formed by melt|dissolving a polymer component in an organic solvent, and preferably heating.

In recent years, large-screen, high-definition liquid crystal TVs have become the main focus, and small display terminals such as smart phones and tablet PCs have been popularized, and the demand for higher quality of liquid crystal elements is higher than before. Then, conventionally, in order to improve the performance of a liquid crystal aligning film and to make the various characteristics of a liquid crystal element excellent, various liquid crystal aligning agents are proposed (for example, refer patent documents 1-3).

In Patent Document 1, together with polyimide, an epoxy compound having a nitrogen atom (for example, N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 1,3 -Containing bis(N,N'-diglycidylaminomethyl)cyclohexane etc.) in a liquid crystal aligning agent is disclosed. Further, in Patent Document 2, a compound containing an imide bond and two or more epoxy groups together with polyamic acid or polyimide (for example, monoallyldiglycidylisocyanuric acid, triglycidylisocyanuric acid etc.) to be contained in the liquid crystal aligning agent is disclosed. Patent Literature 3 discloses that the liquid crystal aligning agent contains a polyfunctional epoxy compound having two or more 3,4-epoxycyclohexane rings together with polyamic acid or polyimide.

Japanese Unexamined Patent Publication No. 10-333153 Japanese Unexamined Patent Publication No. 2007-139949 Japanese Unexamined Patent Publication No. 2016-170409

Liquid crystal elements are not only used in display terminals such as personal computers as in the past, but also, for example, liquid crystal TVs, car navigation systems, mobile phones, smartphones, information displays, retardation films, dimming films, etc., both indoors and outdoors. It is used in a wide variety of applications. In addition, with the expansion of usage applications, it is assumed that the liquid crystal element is used under harsher environments than before. Specifically, the liquid crystal element may be irradiated with a backlight for a long time due to continuous driving for a long time, used in a high-temperature environment, or exposed to a high-temperature environment. On the other hand, the demand for higher performance of liquid crystal elements is increasing, and it is required that element performance can be maintained even under harsh environmental conditions.

This indication was made in view of the said circumstances, and makes it a main objective to provide the liquid crystal aligning agent which can obtain the liquid crystal element excellent in light resistance and heat resistance.

According to this disclosure, the following means are provided.

[1] A liquid crystal aligning agent containing a polymer component and a cyclic siloxane compound [A] having a crosslinkable group.

[2] The liquid crystal alignment film formed using the liquid crystal aligning agent of said [1].

[3] A liquid crystal element provided with the liquid crystal alignment film of the above [2].

[4] a step of forming a photo-alignment film by applying the liquid crystal aligning agent of [1] to each substrate surface of a pair of substrates and irradiating light to the substrate surface; and a pair of substrates on which the photo-alignment film is formed. A method of manufacturing a liquid crystal device, comprising a step of constructing a liquid crystal cell by arranging the photo-alignment layers to face each other with a liquid crystal layer interposed therebetween.

[5] The step of applying the liquid crystal aligning agent of [1] above on each of the conductive films of the pair of substrates having a conductive film to form a coating film, and the pair of substrates on which the coating film was formed, with a liquid crystal layer between them A process for constructing a liquid crystal cell by arranging the coating films facing each other, and a process of irradiating light to the liquid crystal cell in a state where a voltage is applied between the conductive films.

According to the liquid crystal aligning agent of this indication, the liquid crystal element excellent in light resistance and heat resistance can be obtained by containing cyclic siloxane compound [A] together with a polymer component.

(Mode for implementing the invention)

≪Liquid crystal aligning agent≫

The liquid crystal aligning agent of this indication contains a polymer component and an additive component. Further, as an additive component, a cyclic siloxane compound [A] having a crosslinkable group is contained. Below, each component contained in a liquid crystal aligning agent and the other component mix|blended arbitrarily as needed are demonstrated.

In addition, in this specification, a "hydrocarbon group" is the meaning containing a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" means a straight chain hydrocarbon group and a branched hydrocarbon group composed only of a chain structure without including a cyclic structure in the main chain. However, either saturated or unsaturated may be used. An "alicyclic hydrocarbon group" means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it is not necessary to be comprised only of the structure of an alicyclic hydrocarbon, and the thing which has a chain structure in part is also included. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be constituted only of an aromatic ring structure, and may include a chain structure or an alicyclic hydrocarbon structure in part.

<Polymer component>

The polymer component contained in the liquid crystal aligning agent is crosslinked by the cyclic siloxane compound [A]. The kind of main skeleton of a polymer component is not specifically limited. Specific examples of the polymer component include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, polyamideimide, polystyrene, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, and polyacetal, polymaleimide, styrene-maleimide copolymers, or polymers having poly(meth)acrylate as the main skeleton. In addition, (meth)acrylate means containing an acrylate and a methacrylate.

As the polymer component, among these, the crosslinking reaction with the cyclic siloxane compound [A] is easily promoted, the compatibility with the cyclic siloxane compound [A] is better, and the heat when used in combination with the cyclic siloxane compound [A]. From the viewpoint of being able to obtain a liquid crystal element having a high resistance improving effect and higher reliability, from the group consisting of polyamic acid, polyamic acid ester, polyimide, and a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond. It is preferable that it is at least 1 sort(s) selected. The polymer component has a functional group capable of reacting with the crosslinkable group of the cyclic siloxane compound [A] (hereinafter also referred to as "reactive functional group"). The reactive functional group can be appropriately designed according to the crosslinkable group of the cyclic siloxane compound [A]. Preferable examples of the polymer component will be described below.

(polyamic acid)

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

・Tetracarboxylic acid dianhydride

As tetracarboxylic acid dianhydride used for the synthesis|combination of polyamic acid, aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, aromatic tetracarboxylic acid dianhydride etc. are mentioned, for example. Specific examples thereof include, for example, 1,2,3,4-butanetetracarboxylic dianhydride etc. as aliphatic tetracarboxylic dianhydride;

As the alicyclic tetracarboxylic acid dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic 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, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2-anhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarbon acid dianhydrides and the like; As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, In addition to fluoroisopropylidene) diphthalic anhydride and 4,4'-carbonyldiphthalic anhydride, tetracarboxylic dianhydride described in Japanese Unexamined Patent Publication No. 2010-97188 can be used. In addition, as tetracarboxylic acid dianhydride, 1 type can be used individually or in combination of 2 or more types.

・Diamine compound

Examples of the diamine compound used for synthesis of polyamic acid include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples of these diamines include metaxylylenediamine, 1,3-propanediamine, hexamethylenediamine, etc. as aliphatic diamine; as alicyclic diamine, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), etc.;

As aromatic diamine, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-dia Minobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid chole Stanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid lanostanil, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenone C) cholestane, 2,4-diamino-N, N-diallylaniline, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid=5ξ-cholestan-3-yl, diamine having a cyclic carbonate group on the side chain, (meth)acryloyl group Diamine having in the side chain, the following formula (E-1)

(In formula (E-1), XI and ^XII are each independently a single bond, -O-, *-COO- or *-OCO- (provided that "*" ^is a bond with a diaminophenyl group side) represents a hand), 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, and b is an integer of 0 to 2 , c is an integer from 1 to 20, and d is 0 or 1. However, a and b do not become 0 at the same time.)

Side chain type diamines such as compounds represented by:

p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,5-bis (4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, bis[2-(4-aminophenyl)ethyl]hexane diacid, N,N-bis(4-aminophenyl) Methylamine, 1,4-bis-(4-aminophenyl)-piperazine, N,N'-bis(4-aminophenyl)-benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl , 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy) Phenyl] propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'- (phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4 ,4'-bis(4-aminophenoxy)biphenyl, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]dianiline, 4 , 4'-diaminobenzanilide, 4,4'-diaminostilbenzene, 4,4'-diaminodiphenylamine, 1,3-bis (4-aminophenethyl) urea, 1,3-bis ( 4-aminobenzyl)urea, 1,4-bis(4-aminophenyl)-piperazine, N-(4-aminophenylethyl)-N-methylamine, N,N'-bis(4-aminophenyl)- main chain diamines such as N,N'-dimethylbenzidine; As the diaminoorganosiloxane, for example, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like can be exemplified, respectively, and diamines described in Japanese Laid-open Patent Publication No. 2010-97188 can be used. can

･Synthesis of polyamic acid

Polyamic acid can be obtained by reacting tetracarboxylic dianhydride and a diamine compound together with a molecular weight modifier (for example, acid dianhydride, monoamine, etc.) as needed. The use ratio of tetracarboxylic dianhydride and diamine compound used in the polyamic acid synthesis reaction is preferably 0.2 to 2 equivalents of acid anhydride groups of tetracarboxylic dianhydride with respect to 1 equivalent of amino group of the diamine compound.

The synthesis reaction of polyamic acid is preferably conducted in an organic solvent. The reaction temperature at this time is preferably -20°C to 150°C, and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, and hexamethylphosphor. At least one selected from the group consisting of triamide, m-cresol, xylenol, and halogenated phenol is used as a solvent, or at least one of these and other organic solvents (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.) is preferably used. The amount (a) of the organic solvent used is preferably such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by mass with respect to the total amount (a+b) of the reaction solution.

(polyamic acid ester)

Polyamic acid esters are, for example, [I] a method of reacting the polyamic acid obtained by the above synthetic reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic diester with a diamine compound, [III] a method of reacting a tetracarboxylic acid It can be obtained by a method of reacting a diester dihalide compound with a diamine compound, or the like. The polyamic acid ester made to contain in a liquid crystal aligning agent may have only an acid ester structure, and may be a partial esterified product in which an acid structure and an acid ester structure coexist.

(Polyimide)

A polyimide can be obtained, for example, by imidizing the polyamic acid synthesized as described above by dehydration ring closure. From the viewpoint of sufficiently performing a crosslinking reaction with the cyclic siloxane compound [A], the polyimide preferably has an imidation rate of 20 to 99%, more preferably 30 to 90%. The imidation ratio is a percentage of the ratio of the number of imide ring structures to the sum of the number of acid structures and the number of imide ring structures of polyimide. In addition, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of polyamic acid is preferably carried out by a method in which the polyamic acid is dissolved in an organic solvent, a dehydrating agent and a dehydration ring closure catalyst are added to the solution, and heated as necessary. In this method, examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. The amount of the dehydrating agent used is preferably 0.01 to 20 moles per mole of the acid structure of the polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine 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 closure reaction include the organic solvents exemplified as those used in the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours.

(Polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond)

Examples of the polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond (hereinafter also referred to as "polymer [Pm]") include a (meth)acrylic compound and a maleimide compound as a monomer having a polymerizable unsaturated bond. and polymers (poly(meth)acrylate, styrene-maleimide copolymer, polystyrene, polymaleimide) obtained by using at least one of styrene compounds. From the viewpoint of easy introduction of an orientation group and better reliability of the obtained liquid crystal device, the polymer [Pm] is preferably at least one selected from the group consisting of poly(meth)acrylate and styrene-maleimide copolymers. 1 paper When the polymer [Pm] is a styrene-maleimide copolymer, the copolymer may further have a structural unit derived from a monomer (for example, a (meth)acrylic compound) different from the styrene compound and the maleimide compound. good night.

In addition, in this specification, "alignment group" is group which can provide a pretilt angle to the liquid crystal molecule in a liquid crystal layer, when a liquid crystal aligning film is arrange|positioned adjacent to a liquid crystal layer. Specifically, a group capable of imparting a pretilt angle to liquid crystal molecules without depending on light irradiation (hereinafter, also referred to as a "vertical alignment group") and an optical alignment group are exemplified. Specific examples of the vertical alignment group include, for example, an alkyl group of 4 to 20 carbon atoms, an alkoxy group of 4 to 20 carbon atoms, a fluoroalkyl group of 4 to 20 carbon atoms, a fluoroalkoxy group of 4 to 20 carbon atoms, two or more rings ( Preferably, at least one ring selected from the group consisting of a cyclohexane ring, a benzene ring, and a naphthalene ring) is bonded directly or through a divalent linking group (eg, oxygen atom, -CO- or -COO-) a group having a mesogen structure formed by doing so, a group having a steroid skeleton, and the like are exemplified.

The monomer used for the synthesis of polymer [Pm] is not particularly limited as long as it has a polymerizable unsaturated bond, but examples include polymerizable monomers such as (meth)acryloyl group, vinyl group, styryl group, vinylphenyl group or maleimide group. Compounds having an unsaturated bond are exemplified. Specific examples of these compounds include unsaturated carbon acids such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid: alkyl (meth)acrylates (eg, methyl (meth)acrylate, (meth)acrylic acid-2 -Ethylhexyl, etc.), (meth)acrylate cycloalkyl, (meth)acrylate benzyl, (meth)acrylate trimethoxysilylpropyl, (meth)acrylate 2-hydroxyethyl, (meth)acrylate glycidyl, (meth)acrylate unsaturated carboxylic acid esters such as 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxybutyl (meth)acrylate, 4-hydroxybutyl glycidyl ether acrylate; unsaturated polyhydric carboxylic acid anhydrides such as maleic anhydride; (meth)acrylic compounds; aromatic vinyl compounds such as styrene, methylstyrene, divinylbenzene, 4-(glycidyloxymethyl)styrene, and 4-vinylbenzoic acid; conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene;

N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, 4-(2,5-dioxo-3-pyrrolin-1-yl)benzoic acid, N-(4-glycidyloxyphenyl) ) Maleimide, N-glycidylmaleimide, 3-maleimide benzoic acid, 3-maleimide propionic acid, 3-(2,5-dioxo-3-pyrrolin-1-yl) benzoic acid, 4-(2, 5-dioxo-3-pyrrolin-1-yl) maleimide compounds such as methyl benzoate; and the like.

In addition, when polymer [Pm] is a polymer having a photo-alignable group, a compound having a photo-alignable group can also be used as a monomer having a polymerizable unsaturated bond. Specific examples of the compound having a photo-alignable group include maleimide compounds having a cinnamic acid structure, (meth)acrylic compounds having a cinnamic acid structure, and the like. As a monomer which has a polymerizable unsaturated bond, it can use individually by 1 type or in combination of 2 or more types. In addition, in this specification, "(meth)acryloyl" means "acryloyl" and "methacryloyl". "(meth)acryl" means "acryl" and "methacryl".

The polymer [Pm] can be obtained by, for example, polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. As the polymerization initiator used, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy Azo compounds, such as -2, 4- dimethylvaleronitrile), are preferable. The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass based on 100 parts by mass of all the monomers used for the reaction. The polymerization reaction is preferably conducted in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, and hydrocarbon compounds, and diethylene glycol ethyl methyl ether and propylene glycol monomethyl ether acetate are preferable. The reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 to 36 hours. The amount (a) of the organic solvent used is preferably such that the total amount (b) of the monomers used in the reaction is 0.1 to 60% by mass relative to the total amount (a+b) of the reaction solution.

About the polymer component, it is preferable that it is 1,500-500,000, and, as for the weight average molecular weight (Mw) of polystyrene conversion measured by gel permeation chromatography (GPC), it is more preferable that it is 2,500-100,000. In the polymerization reaction for obtaining each polymer, when a reaction solution containing a polymer is obtained, the reaction solution may be used as it is for preparation of a liquid crystal aligning agent, or after isolating a polymer, it is used for preparation of a liquid crystal aligning agent also good A method for isolating the polymer is not particularly limited, and a known method can be used.

When providing liquid-crystal orientation ability using the photo-alignment method with respect to the organic film formed using the liquid crystal aligning agent, it is preferable to use at least one part of a polymer component as a polymer which has a photo-alignment group. The photoalignable group refers to a functional group capable of imparting anisotropy to a film through a photoreaction such as a photoisomerization reaction by light irradiation, a photodimerization reaction, an optical fleece rearrangement reaction, or a photolysis reaction.

Specific examples of the photoalignable group include, for example, an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone or its A chalcone-containing group containing a derivative as a basic skeleton, 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, and cyclobutane or a derivative thereof as a basic skeleton a cyclobutane-containing structure containing cyclobutane, a stilbene-containing group having stilbene or a derivative thereof as a basic skeleton, and a phenylbenzoate-containing group containing phenylbenzoate or a derivative thereof as a basic skeleton. Among these, the photo-alignable group is preferably at least one selected from the group consisting of an azobenzene-containing group, a cinnamic acid structure-containing group, a chalcone-containing group, a stilbene-containing group, a cyclobutane-containing group, and a phenylbenzoate-containing group, and It is preferably a cinnamic acid structure-containing group or a cyclobutane-containing structure from the viewpoint of high sensitivity to and easy introduction into the polymer.

The polymer having an optical orientation group can be obtained by, for example, (1) a method obtained by polymerization using a monomer having an optical orientation group, (2) synthesizing a polymer having an epoxy group in a side chain, the epoxy group-containing polymer thereof, and a polymer having an optical orientation group. It can be obtained by a method of reacting carbonic acid or the like. The content ratio of the photo-alignable group in the polymer is appropriately set according to the type of the photo-alignable group so as to impart desired liquid crystal orientation ability to the coating film. For example, when the photo-alignable group is a cinnamic acid structure-containing group, the content of the photo-alignable group is preferably 5 mol% or more, and preferably 10 to 60 mol%, with respect to all structural units of the polymer having the photo-alignable group. more preferable When the photo-alignable group is a cyclobutane-containing structure, the content of the photo-alignable group is preferably 50 mol% or more, more preferably 80 mol% or more, with respect to all structural units of the polymer having the photo-alignable group. Moreover, as a polymer which has a photo-alignable group, you may use individually by 1 type, and may use it in combination of 2 or more type.

Although single 1 type may be sufficient as the polymer component made to contain in a liquid crystal aligning agent, it is preferable to set it as a polymer blend containing 2 or more types of polymers. In this case, the two or more types of polymers may be polymers of the same type (for example, polyamic acid and polyamic acid), and may be polymers of different types of monomers used, or different types of polymers (for example, polyamic acid and polyamic acid). methacrylate) may also be used. When blending a crosslinking agent in the polymer blend system, if the dispersibility of the crosslinking agent in the liquid crystal aligning agent is not sufficient, the crosslinking reaction of the polymer by the crosslinking agent is not performed efficiently, and the effect of blending the crosslinking agent is reduced. Worried about not being able to get enough. On the other hand, according to the cyclic siloxane compound [A], compatibility with polymers and solubility in solvents are high, and it is considered that it can be easily dispersed at crosslinking points of polymers. As a result, it is estimated that the reaction efficiency of the crosslinking reaction can be increased even in the case of a polymer blend, and a liquid crystal element excellent in light resistance and heat resistance can be obtained.

As a preferable example of the liquid crystal aligning agent, the liquid crystal aligning agent contains a first polymer and a second polymer having higher polarity than the first polymer. In this case, the highly polar second polymer is unevenly distributed in the lower layer, and the first polymer is unevenly distributed in the upper layer to cause phase separation, which is preferable. As a preferable aspect of the polymer component of a liquid crystal aligning agent, the following (I) - (III) are mentioned.

(I) An aspect in which the first polymer and the second polymer are polymers selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

(II) An aspect in which one of the first polymer and the second polymer is one type of polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and the other is polymer [Pm].

(III) An aspect in which the first polymer and the second polymer are polymer [Pm].

In the aspect (II) above, the content ratio of the total of polyamic acid, polyamic acid ester, and polyimide is in the liquid crystal aligning agent from the viewpoint of achieving cost reduction while sufficiently obtaining the improvement effect by the polymer [Pm]. With respect to the total amount of the polymer components contained, it is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 50 to 90% by mass. When imparting liquid-crystal orientation ability to an organic film formed using a liquid crystal aligning agent by a photo-alignment method, by using a polymer [Pm] as a polymer having a photo-alignment group, it is preferred from the viewpoint that an orientation film with high liquid-crystal orientation can be obtained. do.

The content rate of the polymer component in the liquid crystal aligning agent is 50% by mass or more with respect to the total mass of the solid content contained in the liquid crystal aligning agent (total mass of components other than the solvent of the liquid crystal aligning agent) from the viewpoint of sufficiently increasing the film strength. It is preferable to set it as, it is more preferable to set it as 60 mass % or more, and it is still more preferable to set it as 70 mass % or more.

<Cyclic siloxane compound [A]>

The cyclic siloxane compound [A] is a cyclic compound having one cyclic backbone formed by a siloxane bond (Si-O bond) in a molecule, and has a crosslinkable group. The crosslinkable group is not particularly limited as long as it is a group capable of forming a crosslinked structure by covalently bonding with another group, and examples thereof include oxiranyl group, oxetanyl group, (meth)acryloyl group, allyl group, vinylphenyl group, cyclic carbonate group, methyl Ol group, amino group, etc. are mentioned. The crosslinkable group is preferably at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, and a (meth)acryloyl group from the viewpoint of being able to increase the storage stability of the liquid crystal aligning agent, and the oxiranyl group is particularly desirable. In addition, in this specification, "(meth)acryloyl" is the meaning containing "acryloyl" and "methacryloyl".

The number of crosslinkable groups in one molecule of the cyclic siloxane compound [A] is preferably two or more, more preferably three or more, from the viewpoint of sufficiently improving the heat resistance and light resistance of the obtained liquid crystal device. It is more preferable that there are more than one. Moreover, the number of crosslinkable groups which one molecule of cyclic siloxane compound [A] has has more favorable compatibility with a polymer component, the point which can make dispersibility in a liquid crystal aligning agent higher, and the liquid crystal aligning film formed From the viewpoint of suppressing performance degradation due to film shrinkage, the number is preferably 10 or less, and more preferably 8 or less.

When forming a liquid crystal aligning film using a liquid crystal aligning agent, by heating at the time of film formation, the crosslinkable group which cyclic siloxane compound [A] has and the reactive functional group which a polymer component has reacts, and a crosslinked structure is formed. The combination of the crosslinkable group and the reactive functional group is appropriately selected according to storage stability, ease of incorporation into a polymer, reactivity to heat or light, and the like. Specifically, when the crosslinkable group is an epoxy group, examples of the reactive functional group include a carboxyl group, a hydroxyl group, an amino group, and the like, and from the viewpoint of good storage stability, a carboxyl group is preferred. Moreover, when a crosslinkable group is a (meth)acryloyl group, a thiol group, a (meth)acryloyl group, etc. are mentioned as a reactive functional group. When a crosslinkable group is a vinyl group, a thiol group, a vinyl group, etc. are mentioned as a reactive functional group, When a crosslinkable group is an amino group, a carboxyl group, a hydroxyl group, an epoxy group, a halogen atom, etc. are mentioned as a reactive functional group. When the crosslinkable group is a cyclic carbonate group, examples of the reactive functional group include an amino group, a hydroxyl group, a carboxyl group, an epoxy group, and an acid anhydride group, and when the crosslinkable group is a methylol group, examples of the reactive functional group include an epoxy group, an amino group, a hydroxyl group, and a carboxyl group. can be heard However, it is not limited to these combinations.

It is preferable that cyclic siloxane compound [A] is a compound represented by following formula (1).

(In Formula (1), R ¹ to ^{R 6} are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. However, at least one of R ¹ to R ⁶ has a crosslinkable group; 1 It is a valent organic group. n is an integer of 1 to 18. When n is 2 or more, a plurality of R ¹ 's may be the same as or different from each other, and a plurality of R ^{2 '} s may be the same as or different from each other.)

In the above formula (1), when R ¹ to ^{R 6} are monovalent organic groups, specific examples thereof include a monovalent hydrocarbon group having 1 to 20 carbon atoms, wherein at least one hydrogen atom of the monovalent hydrocarbon group is substituted with a crosslinkable group, -O-, -COO-, -S-, -NR ¹⁰ - or -CONR ¹⁰ - (R ¹⁰ is a hydrogen atom or a carbon atom of 1 to 10 monovalent hydrocarbon group), and a group Q3 in which at least one hydrogen atom of the monovalent group Q2 is substituted with a crosslinkable group. These groups may have substituents. As a substituent, a hydroxyl group, a halogen atom, etc. are mentioned, for example. When R ¹ to ^{R 6} are monovalent hydrocarbon groups, the monovalent hydrocarbon group is preferably an alkyl group, an alkenyl group or a phenyl group, and more preferably an alkyl group.

R ¹ to ^{R 6} are the points that can further improve the dispersibility of the cyclic siloxane compound [A] in the liquid crystal aligning agent, and the compatibility with polymer components and the solubility to solvents can be further improved. From this point, it is preferably a monovalent organic group of 1 to 20 carbon atoms, and more preferably a monovalent hydrocarbon group of 1 to 20 carbon atoms, monovalent group Q1, monovalent group Q2, or monovalent group Q3. The carbon number of R ¹ to R ⁶ is preferably 1 to 15, more preferably 1 to 10.

When R ¹ to ^{R 6} are a monovalent organic group having a crosslinkable group, the monovalent organic group having a crosslinkable group is preferably a group represented by the following formula (2).

* ¹ -R ⁷ -X ¹ … (2)

(In Formula (2), R ⁷ is a divalent group having a chain structure, and X ¹ is a monovalent group having a crosslinkable group. “* ¹ ” indicates a bond with a silicon atom.)

In the formula (2), the chain structure of R ⁷ is preferably -O- or -S- between the carbon-carbon bonds of the alkanediyl group of 1 to 10 carbon atoms or the alkanediyl group of 2 to 10 carbon atoms. It is a divalent group having , and may have a substituent. As a substituent, a hydroxyl group, a halogen atom, etc. are mentioned, for example. The carbon number of R ⁷ is preferably 1 to 7, more preferably 2 to 5.

X ¹ is preferably a monovalent group having an oxiranyl group, an oxetanyl group, a (meth)acryloyl group, an allyl group, a vinylphenyl group, a cyclic carbonate group, a methylol group or an amino group, and the viewpoint of storage stability of the liquid crystal aligning agent In , a monovalent group having an oxiranyl group, an oxetanyl group or a (meth)acryloyl group is more preferred, and a monovalent group having an epoxy group (oxiranyl group or oxetanyl group) is particularly preferred. As a monovalent group which has an epoxy group, an epoxy group, a glycidyloxy group, an epoxy cyclohexyl group etc. are mentioned, for example.

In the two monovalent groups bonded to the silicon atom in the formula (1), at least one (R ¹ , R ³ and R ⁵ ) is a group represented by the formula (2), and the other (R ² , R ⁴ and R 5 ) ⁶ ) is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ² , R ⁴ and R ⁶ are more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group or an ethyl group.

n is preferably from 1 to 10, more preferably from 1 to 6, from the viewpoints of the dispersibility of the cyclic siloxane compound [A] in the liquid crystal aligning agent, compatibility with polymer components, and ease of availability of materials. and 1 to 4 are particularly preferred.

The cyclic siloxane compound [A] may further have a photoreactive group. Since the cyclic siloxane compound [A] has a photoreactive group, self-crosslinking by thermal reaction of the photoreactive group can occur, and when a liquid crystal device is obtained by PSA treatment, light resistance and heat resistance equivalent to that of a crosslinkable group can be obtained. It is desirable in that As the photoreactive group, a group having a carbon-carbon unsaturated bond is preferable, and examples thereof include a (meth)acryloyl group, a vinylphenyl group, and a vinyl group. Among these, a (meth)acryloyl group is particularly preferable in terms of high photoreactivity and easy self-crosslinking by thermal reaction of the photoreactive group. In addition, the photoreactive group is a functional group that does not cause a crosslinking reaction between the reactive functional groups introduced into the polymer component in order to crosslink the polymer component with the cyclic siloxane compound [A].

When the cyclic siloxane compound [A] has a photoreactive group, the crosslinkable group of the cyclic siloxane compound [A] is preferably a group having no polymerizable unsaturated bond, specifically an epoxy group, an amino group, a cyclic carbonate group, methylol can lift As for the number of photoreactive groups, when cyclic siloxane compound [A] has a photoreactive group, it is preferable that it is 1 or more, and it is more preferable that it is 2 or more. In addition, the number of photoreactive groups is preferably 4 or less, and preferably 2 or less, in order to sufficiently secure the number of introduced crosslinkable groups.

The molecular weight of the cyclic siloxane compound [A] is easily dispersed in the liquid crystal aligning agent, the compatibility with the polymer component and the solubility in the solvent can be improved, and the film strength of the liquid crystal aligning film can be sufficiently secured. From the point of view, it is preferably less than 1000, more preferably 900 or less, and still more preferably 800 or less. The molecular weight of the cyclic siloxane compound [A] is preferably 100 or more, and more preferably 200 or more, from the viewpoint of suppressing volatilization of the cyclic siloxane compound [A].

Specific examples of the cyclic siloxane compound [A] include compounds represented by each of the following formulas (A-1) to (A-10). As the cyclic siloxane compound [A], you may use a commercial item. Commercially available products include, for example, CS-697, CS-783 (above, manufactured by Sigma-Aldrich), KR-470, X-40-2670, and X-40-2678 (above, manufactured by Shin-Etsu Silicone Co., Ltd.). there is.

(In formulas (A-1) to (A-7), R is a hydrogen atom or a methyl group, and n is an integer of 0 to 18.)

The content ratio of the cyclic siloxane compound [A] is 0.01 part by mass or more with respect to 100 parts by mass of the total amount of polymer components contained in the liquid crystal aligning agent, from the point where the effect of improving the light resistance and heat resistance of the resulting liquid crystal element can be sufficiently high. It is preferable, it is more preferable that it is 0.05 mass part or more, and it is still more preferable that it is 0.1 mass part or more. Moreover, it is preferable that the content rate of the cyclic siloxane compound [A] is 40 parts by mass or less with respect to 100 parts by mass of the total amount of polymer components contained in the liquid crystal aligning agent from the viewpoint of being able to suppress film shrinkage at the time of liquid crystal aligning film formation. And, it is more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less. Moreover, as cyclic siloxane compound [A], you may use individually by 1 type, and may use it in combination of 2 or more type.

<other ingredients>

The liquid crystal aligning agent of this indication may contain other compounds other than a polymer component and cyclic siloxane compound [A] as needed. Specific examples thereof include, for example, epoxy compounds (e.g., N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidyl) Aminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-aminomethylcyclohexane, 1,6- Hexanedioldi(meth)acrylate, pentaerythritol tri(meth)acrylate, etc.), functional silane compounds (e.g., 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- aminopropyl trimethoxysilane, etc.), antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersing agents, photosensitizers, and the like. The blending ratio of the other compounds can be appropriately selected according to each compound within a range not impairing the effect of the present disclosure.

Moreover, when using together a compound different from a cyclic siloxane compound [A] as a crosslinking agent, it is preferable to make the content rate of this compound into 5 mass % or less with respect to the total amount of cyclic siloxane compound [A] contained in a liquid crystal aligning agent. And it is more preferable to set it as 1 mass % or less.

・Solvent component

The liquid crystal aligning agent of the present disclosure is prepared as a solution-like composition in which a polymer component, a cyclic siloxane compound [A], and a component optionally blended as needed are preferably dissolved in an organic solvent. Examples of the organic solvent include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. The solvent component may be one of these, or a mixed solvent of two or more.

Examples of the solvent component include a solvent having high polymer solubility and leveling properties (hereinafter also referred to as "first solvent"), a solvent having good wet spreadability (hereinafter also referred to as "second solvent"), and mixed solvents thereof. can

Specific examples of the solvent include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, and N,N-dimethylacetamide as the first solvent. , 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone, ethylene carbonate, propylene carbonate, N-ethyl-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-butoxy-N,N-dimethylpropane amides, 3-methoxy-N,N-dimethylpropanamide and the like;

As the second solvent, for example, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, diethylene glycol dimethyl ether, diethylene Glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 3-methoxy-1-butanol, cyclopentanone, butyl lactate, butyl acetate, methyl methoxypropionate , ethyl ethoxy propionate, isoamyl propionate, isoamyl isobutyrate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, diisopentyl ether and the like, respectively. In addition, although these 1 type may be sufficient as a solvent individually, it is preferable that it is a mixed solvent of a 1st solvent and a 2nd solvent.

The solid content concentration (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) in the liquid crystal aligning agent is appropriately selected in consideration of viscosity, volatility, etc., but is preferably 1 to 10 It is the range of mass %. When solid content concentration is less than 1 mass %, the film thickness of a coating film becomes too small and it becomes difficult to obtain a favorable liquid crystal aligning film. On the other hand, when solid content concentration exceeds 10 mass %, the film thickness of a coating film becomes excessive and it is difficult to obtain a favorable liquid crystal aligning film, and the viscosity of a liquid crystal aligning agent increases and there exists a tendency for applicability to fall.

≪Liquid crystal alignment film and liquid crystal element≫

The liquid crystal aligning film of this indication is formed of the liquid crystal aligning agent prepared as mentioned above. Moreover, the liquid crystal element of this indication is equipped with the liquid crystal aligning film formed using the liquid crystal aligning agent demonstrated above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and examples thereof include TN type, STN type, VA type (including VA-MVA type and VA-PVA type), and IPS (In-Plane Switching) type. , FFS (Fringe Field Switching) type, OCB (Optically Compensated Bend) type, PSA (Polymer Sustained Alignment) type, etc. can be applied to various modes. A liquid crystal element can be manufactured by the method including the following process 1 - process 3, for example. In Step 1, the substrate used is different depending on the desired operation mode. Process 2 and process 3 are common to each operation mode.

<Process 1: Formation of coating film>

First, a liquid crystal aligning agent is applied to each substrate surface in a pair of substrates, and preferably a coating film is formed on the substrate by heating the coated surface. As a board|substrate, For example, glass, such as float glass and soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly(alicyclic olefin) can be used. Examples of the transparent conductive film formed on one surface of the substrate include a 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 ), and the like. is available. In the case of manufacturing a TN type, STN type or VA type liquid crystal device, two substrates on which a patterned transparent conductive film is formed are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal device, a substrate on which comb-shaped electrodes are formed and a counter substrate on which no electrodes are formed are used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode formation surface by an offset printing method, a flexographic printing method, a spin coating method, a roll coater method or an inkjet printing method.

After applying the liquid crystal aligning agent, for the purpose of preventing liquid flow of the applied liquid crystal aligning agent, etc., preheating (prebaking) is preferably performed. The prebaking temperature is preferably 30 to 200°C, and the prebaking time is preferably 0.25 to 10 minutes. After that, the solvent is completely removed and, if necessary, a firing (post-baking) step is performed for the purpose of thermal imidation of the acid structure in the polymer component. The firing temperature (post-baking temperature) at this time is preferably 80 to 250°C, more preferably 80 to 200°C. Post-baking time is preferably 5 to 200 minutes. The thickness (film thickness) of the film thus formed is preferably 0.001 to 1 μm.

<Process 2: Orientation treatment>

When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal element, a process (orientation process) for imparting liquid crystal alignment ability to the coating film formed in the above step 1 is performed. Thereby, the orientation ability of liquid crystal molecules is given to a coating film, and it becomes a liquid crystal alignment film. As the orientation treatment, a rubbing treatment in which the coating film formed on the substrate is rubbed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, cotton, etc., or a coating film formed on the substrate is irradiated with light, A photo-alignment treatment or the like that imparts liquid-crystal orientation ability to the coating film to form a photo-alignment layer can be used. On the other hand, when manufacturing a vertical alignment (VA) type liquid crystal element, the coating film formed in step 1 can be used as a liquid crystal alignment film as it is. good night. A liquid crystal aligning film suitable for a vertical alignment type liquid crystal element can be suitably used also for a PSA type liquid crystal element.

In the photo-alignment treatment, the light irradiation is applied to the coating film after the post-baking step, the method of irradiating the coated film after the pre-baking step and before the post-baking step, and the coating film in at least any one of the pre-baking step and the post-baking step. It can be carried out by a method of irradiating the coating film during heating, or the like. As the radiation applied to the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. Preferably, it is an ultraviolet light containing light with a wavelength of 200 to 400 nm. 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, may be performed from an oblique direction, or a combination thereof may be performed. The irradiation direction in the case of unpolarized radiation is oblique.

As a light source used, 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 etc. are mentioned, for example. The dose of radiation to the substrate surface is preferably 400 to 50,000 J/m 2 , more preferably 1,000 to 20,000 J/m 2 . After light irradiation for imparting orientation ability, the surface of the substrate is treated with, for example, water or an organic solvent (eg, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) Alternatively, a cleaning process or a substrate heating process may be performed using a mixture thereof.

<Process 3: Construction of liquid crystal cell>

As mentioned above, two board|substrates on which the liquid crystal aligning film was formed are prepared, and a liquid crystal cell is manufactured so that a liquid crystal may be arrange|positioned adjacent to a liquid crystal aligning film between two board|substrates. To manufacture a liquid crystal cell, for example, two substrates are placed facing each other through a gap so that the liquid crystal alignment films face each other, and the periphery of the two substrates is bonded with a sealant, and the substrate surface and the cell gap surrounded by the sealant A method of sealing an injection hole by injecting and filling a liquid crystal, a method by an ODF method, and the like are exemplified. As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, and among these, nematic liquid crystals are preferable. In the PSA mode, after the liquid crystal cell is built, light irradiation is performed on the liquid crystal cell in a state where a voltage is applied between the conductive films of the pair of substrates.

When manufacturing a PSA type liquid crystal element, a liquid crystal cell is constructed in the same manner as above except for injecting or dropping a photopolymerizable monomer together with a liquid crystal between a pair of substrates having a conductive film. In addition, as a photopolymerizable monomer, a conventionally well-known compound can be used. Preferably, it is a polyfunctional (meth)acrylic monomer. After that, the liquid crystal cell is irradiated with light in a state where a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. Further, as the light to be irradiated, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. Among these, ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferable. As a light source for irradiation light, 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, for example. The irradiation amount of light is preferably 1,000 to 200,000 J/m 2 , more preferably 1,000 to 150,000 J/m 2 .

Subsequently, a polarizing plate is bonded to the outer surface of the liquid crystal cell as needed to obtain a liquid crystal element. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which iodine is absorbed while polyvinyl alcohol is stretched and oriented is interposed with a cellulose acetate protective film, or a polarizing plate made of the H film itself.

The liquid crystal device of the present disclosure can be effectively applied to various applications, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smart phones, It is applicable to various display devices, such as various monitors, liquid crystal TVs, and information displays, dimming films, and retardation films.

Example

Hereinafter, although it demonstrates concretely with examples, this indication is not limited to the following examples.

In the following examples, the solution viscosity of the polymer, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw/Mn), imidation rate, and epoxy equivalent were measured by the following methods.

<Polymer solution viscosity>

The solution viscosity of the polymer was measured at 25°C using an E-type viscometer.

<Weight average molecular weight, number average molecular weight and molecular weight distribution>

Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. The molecular weight distribution (Mw/Mn) was calculated from the obtained Mw and Mn.

Apparatus: "GPC-101" of Showa Denko Co., Ltd.

GPC column: Combined "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" manufactured by Shimadzu GLC

Mobile phase: tetrahydrofuran (THF)

Column temperature: 40°C

Flow rate: 1.0 mL/min

Sample concentration: 1.0% by mass

Sample injection volume: 100 μL

Detector: Differential Refractometer

Standard material: monodisperse polystyrene

<Imidization rate of polymer>

A solution containing polyimide was poured into pure water, and the resulting precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation rate was determined using the following formula (E-1).

Imidization ratio (%) = (1-A ¹ /A ² ×α) × 100 . . . (E-1)

(In the formula (E-1), A ¹ is the peak area derived from protons of NH groups appearing around 10 ppm chemical shift, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid). It is the ratio of the number of other protons to one proton of the NH group in

<epoxy equivalent>

The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.

The abbreviated names of the compounds used in the following examples are shown below. In addition, in the following, for convenience, "the compound represented by formula (X)" may be simply referred to as "compound (X)".

・Cyclic siloxane compound [A]

・Other than cyclic siloxane compound [A]

<Synthesis of Polymer>

[Synthesis Example 2-1: Synthesis of Polyimide]

77 g (0.34 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, and 19 g (0.18 mol) of p-phenylenediamine and 27 g (0.18 mol) of 3,5-diaminobenzoic acid as diamines ) was dissolved in 1,260 g of N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a solution containing polyamic acid. The solution viscosity measured as a solution with a concentration of 10% by mass by fractionating a small amount of the obtained polyamic acid solution and concentrating under reduced pressure was 80 mPa·s. Subsequently, 600 g of NMP was added to the obtained polyamic acid solution, 136 g of pyridine and 105 g of acetic anhydride were added, and a dehydration ring closure reaction was performed at 110°C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is solvent-substituted with new γ-butyrolactone, and further concentrated to obtain 600 g of a solution containing 20% by mass of polymer (PI-1), which is a polyimide having an imidization rate of about 85%. got it A small amount of this solution was fractionated and γ-butyrolactone was added to obtain a solution having a concentration of 6.0% by mass, and the viscosity of the solution measured was 22 mPa·s.

[Synthesis Example 2-2: Synthesis of polyamic acid]

13.8 g (0.070 mol) of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as tetracarboxylic acid dianhydride, 16.3 g (0.0769 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl as diamine mol) was dissolved in 170 g of NMP and reacted at 25°C for 3 hours to obtain a solution containing 10% by mass of polyamic acid (this is referred to as "polymer (PA-1)").

[Synthesis Example 2-3: Synthesis of styrene-maleimide copolymer]

Under nitrogen, in a 100 mL two-necked flask, as polymerized monomers, 5.00 g (8.6 mmol) of compound (MI-1), 0.64 g (4.3 mmol) of 4-vinylbenzoic acid, 4-(2,5-dioxo-3) -Pyrrolin-1-yl)benzoic acid 2.82g (13.0mmol) and 4-(glycidyloxymethyl)styrene 3.29g (17.2mmol), as a radical polymerization initiator 2,2'-azobis (2, 0.31 g (1.3 mmol) of 4-dimethylvaleronitrile), 0.52 g (2.2 mmol) of 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent, and 25 ml of tetrahydrofuran as a solvent are added, It polymerized at 70 degreeC for 5 hours. After re-precipitation in n-hexane, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain a polymer (StMI-A) which is a styrene-maleimide copolymer. The weight average molecular weight Mw measured in terms of polystyrene by GPC was 30000, and the molecular weight distribution Mw/Mn was 2.

[Synthesis Example 2-4: Synthesis of styrene-maleimide copolymer]

In Synthesis Example 2-3, polymerization was carried out in the same manner as in Synthesis Example 2-3 except that Compound (MI-2) was used instead of Compound (MI-1) as a polymerization monomer. After re-precipitation in n-hexane, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain a polymer (StMI-B) which is a styrene-maleimide copolymer. The weight average molecular weight Mw measured in terms of polystyrene by GPC was 25000, and the molecular weight distribution Mw/Mn was 2.

[Synthesis Example 2-5: Synthesis of Epoxy Group-Containing Polyorganosiloxane]

Into a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were placed. , mixed at room temperature. After 100 g of deionized water was added dropwise thereto over 30 minutes from a dropping funnel, the mixture was reacted at 80°C for 6 hours while mixing under reflux. After completion of the reaction, the organic layer was taken out, washed with a 0.2% by mass ammonium nitrate aqueous solution until the water after washing became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a viscous polyorganosiloxane containing an epoxy group. Obtained as a clear liquid. As a result of measuring the epoxy equivalent of this epoxy group-containing polyorganosiloxane (this is referred to as "polyorganosiloxane (PS-1)"), it was 186 g/equivalent.

<Preparation and evaluation of liquid crystal aligning agent>

[Example 1]

1. Preparation of liquid crystal aligning agent (AL-1)

To a solution containing 100 parts by mass of the polymer (PI-1) obtained in the above Synthesis Example 2-1, 10 parts by mass of the polymer (StMI-A) obtained in the above Synthesis Example 2-3, compound (A-1-1) (trade name) "KR-470", manufactured by Shin-Etsu Silicone Co., Ltd.) 2 parts by mass, and NMP and butyl cellosolve (BC) were added as solvents, the solvent composition was NMP/BC = 50/50 (mass ratio), and the solid content concentration was 4.0 mass% was made with a solution of A liquid crystal aligning agent (AL-1) was prepared by filtering this solution with a filter having a hole diameter of 1 µm.

2. Manufacture of optical vertical type liquid crystal display device

The liquid crystal aligning agent (AL-1) prepared above was applied using a spinner on the transparent electrode surface of a glass substrate with transparent electrodes made of an ITO film, and prebaking was performed on a hot plate at 80°C for 1 minute. Thereafter, in an oven in which the inside of the chamber was purged with nitrogen, it was heated at 230°C for 1 hour to form a coating film having a thickness of 0.1 µm. Next, the surface of this coating film was irradiated with polarized ultraviolet rays of 1,000 J/m2 including bright lines of 313 nm from a direction inclined at 40° with respect to the normal line of the substrate using an Hg-Xe lamp and a Glantaylor prism, and the liquid crystal was applied to the coating film. Orientation was given. The same operation was repeated and a pair (two sheets) of board|substrates which have a liquid crystal aligning film were created.

An epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 µm was applied by screen printing to the outer periphery of the surface having the liquid crystal alignment film on one of the pair of substrates on which the liquid crystal alignment film was formed. Subsequently, the liquid crystal alignment film surfaces of the pair of substrates were opposed to each other, and bonding was performed so that the projection direction of the optical axis of each substrate onto the substrate surface was antiparallel, and the adhesive was heat-cured at 150° C. for 1 hour. Next, after filling the gap between the substrates with negative liquid crystal (MLC-6608 manufactured by Merck Co., Ltd.) from the liquid crystal inlet, the liquid crystal inlet was sealed with an epoxy adhesive. Moreover, in order to remove flow orientation at the time of liquid crystal injection, after heating this at 130 degreeC, it cooled slowly to room temperature, and obtained the liquid crystal cell. Next, a polarizing plate is bonded to both outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other, and the projection direction of the optical axis of the liquid crystal aligning film to the substrate surface of the ultraviolet rays forms an angle of 45 degrees, thereby forming an optical vertical type liquid crystal display device. has manufactured

3. Evaluation of liquid crystal display elements

Said operation was repeated, the liquid crystal display element was manufactured in multiple numbers, and the following heat resistance and light resistance were evaluated. In addition, evaluation of heat resistance and light resistance was performed using each separate liquid crystal display element.

[Evaluation of heat resistance]

After applying a voltage of 5V at 60°C to the optical vertical liquid crystal display device prepared above with an application time of 60 microseconds and a span of 167 milliseconds, the voltage retention rate 167 milliseconds after release was measured, which was measured as an initial value. The voltage holding factor Arf [%] was used. Next, after leaving this liquid crystal cell still in a 100 degreeC oven for 1,000 hours and applying thermal stress, the voltage retention rate was measured again under the same conditions, and this was defined as the voltage retention rate after thermal stress Atm [%]. The amount of decrease α[%] (α=Arf-Atm) of the voltage holding rate Atm after thermal stress with respect to the initial voltage holding rate Arf was calculated, and the heat resistance of the liquid crystal display element was evaluated by the amount of decrease α. Heat resistance "very good (◎)" when the fall amount α was 1% or less, heat resistance "good (○)" when the fall amount α was more than 1% and 2% or less, and 2% when the fall amount α was 2% The case where it exceeded and was 3% or less was evaluated as "possible (Δ)" in heat resistance, and the case where the amount of decrease α exceeded 3% was evaluated as "defective (x)" in heat resistance. As a result, in this Example, the heat resistance was evaluated as "very good (◎)". In addition, VHR-1 manufactured by Toyo Technica Co., Ltd. was used as a voltage holding factor measuring device.

[Evaluation of light fastness]

About the optical vertical type liquid crystal display element manufactured above, the voltage holding factor was measured under the conditions similar to the evaluation of heat resistance, and this was made into the initial voltage holding rate Arf [%]. Subsequently, the liquid crystal display element was left at a distance of 5 cm under a 0-watt white fluorescent lamp, irradiated with light for 1,000 hours to give light stress, and then again, the voltage conservation rate was measured under the same conditions, and the voltage conservation rate after light stress Agt It was set as [%]. The amount of decrease β [%] (β=Arf-Agt) of the voltage holding rate Agt after light stress with respect to the initial voltage holding rate Arf was calculated, and the light resistance of the liquid crystal display element was evaluated by the amount of decrease β. When the decrease amount β was 1% or less, the light resistance was “very good (◎)”, and when the decrease amount β was more than 1% and 2% or less, the light resistance was “good (○)”, and the decrease amount β was 2%. The case where the light resistance exceeded 3% or less was evaluated as "possible (Δ)", and the case where the decrease amount β exceeded 3% was evaluated as the light resistance "defective (x)". As a result, in this Example, the light resistance was evaluated as "very good (◎)".

[Examples 2 to 9 and Comparative Examples 1, 2, 4, 6]

The liquid crystal aligning agent was prepared with the same solvent composition and solid content concentration as Example 1 except having changed the compounding composition as shown in Tables 1 to 3 below. Moreover, using each liquid crystal aligning agent, it carried out similarly to Example 1, the optical vertical type liquid crystal display element was manufactured, and various evaluation was performed. Their results are shown in Tables 1 to 3 below.

[Example 10]

1. Preparation of liquid crystal aligning agent (AL-10)

The above examples except that the polymer used was changed to a solution containing 100 parts by mass of the polymer (PA-1) obtained in the above Synthesis Example 2-2 and 10 parts by mass of the polymer (StMI-B) obtained in the above Synthesis Example 2-4. The liquid crystal aligning agent (AL-10) was prepared with the same solvent composition and solid content concentration as 1.

2. Preparation of liquid crystal composition

5% by mass of the liquid crystalline compound represented by the above formula (L1-1) and 0.3 mass% of the photopolymerizable compound represented by the above formula (L2-1) with respect to 10 g of nematic liquid crystal (manufactured by Merck Co., Ltd., MLC-6608) Liquid crystal composition LC1 was obtained by adding % and mixing.

3. Manufacture of PSA type liquid crystal display element

The liquid crystal aligning agent (AL-10) prepared above is applied on each electrode surface of two glass substrates each having a conductive film made of an ITO electrode using a liquid crystal alignment film printing machine (manufactured by Nippon Shashin Insatsu Co., Ltd.) After removing the solvent by heating (prebaking) on a hot plate at 80 ° C. for 2 minutes, heating (post-baking) on a hot plate at 230 ° C. for 10 minutes formed a coating film with an average film thickness of 0.06 μm. About these coating films, after performing ultrasonic cleaning in ultrapure water for 1 minute, by drying for 10 minutes in a 100 degreeC clean oven, a pair (2 sheets) of board|substrates which have a liquid crystal aligning film were obtained. In addition, the electrode pattern used is the same type as the electrode pattern in the PSA mode.

Subsequently, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of one of the pair of substrates, and then the liquid crystal alignment film surfaces were overlapped and crimped together so that the surfaces faced each other, and the adhesive was hardened Then, after filling the liquid crystal composition LC1 prepared above between the pair of substrates from the liquid crystal inlet, the liquid crystal cell was manufactured by sealing the liquid crystal inlet with an acrylic photocuring adhesive. After that, an alternating current of 10 V with a frequency of 60 Hz was applied between the conductive films of the liquid crystal cell, and in a state in which the liquid crystal was driven, ultraviolet rays were irradiated at an irradiation amount of 100,000 J/m 2 using an ultraviolet irradiation device using a metal halide lamp as a light source. investigated In addition, this irradiation amount is a value measured using a photometer measured on the basis of a wavelength of 365 nm. Thereafter, polarizing plates are bonded to both outer surfaces of the substrate so that their polarization directions are orthogonal to each other and the projection direction of the optical axis of the liquid crystal aligning film's ultraviolet rays onto the substrate surface forms an angle of 45°, thereby forming a PSA type liquid crystal display element. manufactured

4. Evaluation of liquid crystal display elements

Said operation was repeated, the liquid crystal display element was manufactured in multiple numbers, and it carried out similarly to Example 1, and evaluated heat resistance and light resistance. As a result, in this Example, both heat resistance and light resistance were evaluated as "very good (⊚)".

[Examples 11 to 13 and Comparative Examples 3 and 5]

The liquid crystal aligning agent was prepared with the same solvent composition and solid content concentration as Example 10 except having changed the compounding composition as shown in Table 2 and Table 3 below. Moreover, it carried out similarly to Example 10 using each liquid crystal aligning agent, and manufactured the PSA type|mold liquid crystal display element, and carried out similarly to Example 1, and performed various evaluation. Their results are shown in Table 2 and Table 3 below.

In Tables 1 to 3, "-" indicates that the compound in the corresponding column was not used. The abbreviated name of the compound is as follows.

A-1-1: product name "KR-470", manufactured by Shin-Etsu Silicone Co., Ltd. (compound represented by the above formula (A-1-1))

A-2-1: Product name "CS-697", manufactured by Sigma-Aldrich (a compound represented by the above formula (A-2-1))

A-3-1: product name "CS-783", manufactured by Sigma-Aldrich (compound represented by the formula (A-3-1))

C-1: Product name "X-40-2669", manufactured by Shin-Etsu Silicone Co., Ltd. (compound represented by the above formula (C-1))

C-2: Polyorganosiloxane of Synthesis Example 2-5 (PS-1)

C-3: N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane (compound represented by the above formula (C-3))

From the above results, in Examples 1 to 13 using a liquid crystal aligning agent containing a cyclic siloxane compound [A] as a crosslinking agent, evaluation of heat resistance and light resistance of the liquid crystal display element was "very good (◎)" or "good (○)" 」 was the result.

On the other hand, in Comparative Examples 4 and 5 made of the same composition as the liquid crystal aligning agents of Examples 1 to 3 and Examples 10 to 13 except that the cyclic siloxane compound [A] was not contained, compared to the Examples, light resistance and heat resistance were improved. Both sides were behind.

Further, in Comparative Example 1 using Compound (C-1), which is a polyfunctional siloxane compound having a chain structure, in place of the cyclic siloxane compound [A], the light resistance was inferior to that of Examples (Examples 1 to 3), and About Examples 1 and 2, heat resistance was also inferior. In Comparative Examples 2 and 3 using polyorganosiloxane (PS-1) in place of the cyclic siloxane compound [A], both light resistance and heat resistance were lower than in Examples (Examples 1 to 3 and Examples 10 to 13). was behind

Also, Comparative Example 6 using Compound (C-3), which is a conventionally used crosslinking agent, was inferior in both light resistance and heat resistance to those of Examples.

From these results, it was found that a liquid crystal element excellent in heat resistance and light resistance could be obtained by using the cyclic siloxane compound [A] as a crosslinking agent.

Claims (8)

containing a polymer component and a cyclic siloxane compound [A] having a crosslinkable group;
The polymer component is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond,
The said cyclic siloxane compound [A] is a liquid crystal aligning agent which is a compound represented by following formula (1).

(In Formula (1), R ¹ to ^{R 6} are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; provided that at least one of R ¹ to ^{R 6} has a crosslinkable group; 1 The valent organic group is a group represented by the following formula (2); n is an integer of 1 to 18; when n is 2 or more, a plurality of R ¹ 's may be the same or different, and a plurality of R ^{2 '} s may be the same. may be different)
* ¹ -R ⁷ -X ¹ … (2)
(In formula (2), R ⁷ is an alkanediyl group having 1 to 10 carbon atoms or a divalent group having -O- or -S- between the carbon-carbon bonds of the alkanediyl group having 2 to 10 carbon atoms; X ¹ is a monovalent group having an oxiranyl group or an oxetanyl group; "* ¹ " indicates a bond with a silicon atom) delete delete According to claim 1,
The liquid crystal aligning agent containing 2 or more types of polymers as said polymer component. The liquid crystal aligning film formed using the liquid crystal aligning agent of Claim 1 or 4. A liquid crystal element provided with the liquid crystal alignment film according to claim 5. Forming a photo-alignment film by applying the liquid crystal aligning agent according to claim 1 or 4 to each substrate surface of a pair of substrates and irradiating light to the substrate surface;
A step of constructing a liquid crystal cell by arranging a pair of substrates on which the photo-alignment layer is formed so that the photo-alignment layer faces each other with the liquid crystal layer interposed therebetween
Including, a method for manufacturing a liquid crystal device. A step of applying the liquid crystal aligning agent according to claim 1 or 4 onto each of the conductive films of a pair of substrates having a conductive film to form a coating film;
constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so that the coating films face each other with a liquid crystal layer interposed therebetween;
Step of irradiating light to the liquid crystal cell in a state in which a voltage is applied between the conductive films
Including, a method for manufacturing a liquid crystal device.