KR20200098659A - Liquid crystal aligning agent, liquid crystal aligning film, liquid crystal element, and manufacturing method of liquid crystal element - Google Patents

Abstract

The liquid crystal aligning agent contains a polymer component and a heterocycle-containing compound having two or more partial structures in which n (n is an integer of 1 or more) hydrogen atoms have been removed from the structure represented by formula (1) in one molecule. In Formula (1), X ¹ is -CR ¹ =CR ² -. A ¹ is a divalent organic group, and may be bonded to another ring structure to form a condensed ring together with the other ring structure. A plurality of A ¹ and X ¹ in one molecule each independently have the above definition.

Description

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

(Cross reference of related applications)

This application is based on Japanese Patent Application No. 2018-73138 for which it applied on April 5, 2018, and uses the description of the content here.

The present disclosure relates to a liquid crystal aligning agent, a liquid crystal aligning film, a liquid crystal element, and a method of manufacturing a liquid crystal element.

The liquid crystal element is equipped with a liquid crystal aligning film which has a function of aligning liquid crystal molecules in a fixed direction. In general, a liquid crystal aligning film is formed on a substrate by applying a liquid crystal aligning agent obtained by dissolving a polymer component in an organic solvent onto the substrate surface, preferably heating it. In addition, with respect to the organic film formed on the substrate using the liquid crystal aligning agent, rubbing treatment or photo-alignment treatment is performed as necessary, and thus, liquid crystal aligning ability is imparted.

In recent years, large-screen and high-definition liquid crystal TVs have become mainstream, and small-sized display terminals such as smart phones and tablet PCs have been popularized, and the demand for higher quality liquid crystal elements has been increasing and increasing more than before. From this background, various liquid crystal aligning agents have been proposed in order to improve the performance of the liquid crystal aligning film and make various characteristics of the liquid crystal element (e.g., liquid crystal alignment, voltage retention, afterimage characteristics, etc.) For example, see Patent Documents 1 to 3).

In Patent Document 1, in addition to polyimide, an epoxy compound having a nitrogen atom (for example, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 1,3 -A liquid crystal aligning agent containing bis(N,N'-diglycidylaminomethyl)cyclohexane, etc.) is disclosed. According to the liquid crystal aligning agent described in this patent document 1, it is possible to suppress a display defect caused by a rubbing flaw, and it is possible to obtain a liquid crystal aligning film which has excellent liquid crystal aligning property. In addition, in Patent Document 2, a compound containing an imide bond and two or more epoxy groups together with a polyamic acid or polyimide (for example, monoallyl diglycidyl isocyanuric acid, triglycidyl isocyanuric acid Etc.) are disclosed in a liquid crystal aligning agent. Patent Document 3 discloses that a liquid crystal aligning agent contains a polyfunctional epoxy compound having two or more 3,4-epoxycyclohexane rings together with a polyamic acid or polyimide. When forming a liquid crystal aligning film using a liquid crystal aligning agent containing a crosslinking agent, crosslinking progresses by heating (post-baking) at the time of film formation normally, and hardening of a film is accelerated.

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

In order to sufficiently advance the curing of the film by addition of the crosslinking agent and increase the film hardness, it is preferable to perform heating at a high temperature (for example, at 200°C or higher) during film formation. However, when heating at a high temperature is required when forming the liquid crystal aligning film, a problem such as restricting the material of the substrate may occur, and the application of the film substrate as the substrate of the liquid crystal element may be limited. In addition, in a color liquid crystal display element, a dye used as a colorant for a color filter is relatively weak to heat, and there is a concern that the use of the dye is restricted when it is necessary to perform heating at a high temperature during film formation. On the other hand, if the curing of the film is not sufficient, the film hardness is not sufficient, and there is a concern that the liquid crystal orientation and the voltage retention rate decrease.

Further, when the solubility of the polymer component is lowered by the addition of the crosslinking agent, or when the crosslinking agent precipitates in the aligning agent, the coating property of the liquid crystal aligning agent to the substrate is inferior. In addition, there is a concern that the liquid crystal orientation and voltage retention of the obtained liquid crystal element decrease, or the product yield decreases.

The present disclosure has been made in view of the above circumstances, and one object thereof is a liquid crystal device having good coatability to a substrate, high film hardness, and excellent liquid crystal orientation and voltage retention even when film formation is performed at a low temperature. It is in providing the liquid crystal aligning agent which can obtain.

According to the present disclosure, the following means are provided.

[1] Liquid crystal orientation containing a polymer component and a heterocycle-containing compound having two or more partial structures in which n (n is an integer of 1 or more) hydrogen atoms have been removed from the structure represented by the following formula (1) My.

(In formula (1), X ¹ is any of the groups represented by each of the following formulas (2-1) to (2-5). A ¹ is a divalent organic group, and is bonded to another ring structure to be the subject. A condensed ring may be formed together with other ring structures. A plurality of A ¹ and X ¹ in one molecule each independently have the above definition.)

(In formulas (2-1) to (2-5), R ¹ to R ⁷ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 or more carbon atoms. Formulas (2-3) and formulas "*" in (2-5) represents that it is a bond with an oxygen atom in formula (1).)

[2] A liquid crystal aligning film formed using the liquid crystal aligning agent of [1].

[3] A liquid crystal element comprising the liquid crystal alignment film of [2].

[4] The step of forming a liquid crystal aligning film by applying the liquid crystal aligning agent of [1] to each substrate surface in a pair of substrates and irradiating light to the applied substrate surfaces to impart liquid crystal alignment ability, and the A method of manufacturing a liquid crystal element comprising a step of constructing a liquid crystal cell by disposing a pair of substrates having a liquid crystal alignment film formed thereon so that the coated surfaces of the substrates face each other through a liquid crystal layer.

[5] The step of applying the liquid crystal aligning agent of [1] on each of the conductive films of a pair of substrates having a conductive film, and a pair of substrates to which the liquid crystal aligning agent is applied, through a liquid crystal layer A method of manufacturing a liquid crystal element comprising a step of constructing a liquid crystal cell by opposing the coated surface of the substrate to face each other, and a step of irradiating light to the liquid crystal cell while applying a voltage between the conductive films.

According to the liquid crystal aligning agent of the present disclosure, even when heating at the time of film formation is performed at a low temperature (for example, at a temperature of 170° C. or lower), a liquid crystal element excellent in liquid crystal alignment and voltage retention can be obtained. Moreover, the liquid crystal aligning agent of this disclosure is excellent in coating property to a board|substrate, and therefore can suppress a fall in product yield.

(Form for carrying out the invention)

≪Liquid crystal aligning agent≫

The liquid crystal aligning agent of this disclosure contains a polymer component and an additive component. In addition, as an additive component, a heterocycle-containing compound having two or more partial structures in which n (n is an integer of 1 or more) hydrogen atoms have been removed from the structure represented by the above formula (1) (hereinafter referred to as “Compound [W ]"). Hereinafter, each component contained in the liquid crystal aligning agent of the present disclosure and other components optionally blended as necessary will be described.

In addition, in this specification, the "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" does not contain a cyclic structure in the main chain and means a linear hydrocarbon group and a branched hydrocarbon group composed of only a chain structure. However, saturated or unsaturated may be sufficient. The "alicyclic hydrocarbon group" means a hydrocarbon group including only the structure of an alicyclic hydrocarbon and not including an aromatic ring structure as a ring structure. However, it is not necessary to consist only of the structure of an alicyclic hydrocarbon, and a part having a chain structure is included. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to constitute only an aromatic ring structure, and a chain structure or a structure of an alicyclic hydrocarbon may be included in a part thereof.

<polymer component>

As long as the polymer component contained in the liquid crystal aligning agent is crosslinked by the compound [W], its main skeleton is not particularly limited. As specific examples of the polymer component, for example, polyamic acid, polyamic acid ester, polyimide, polyamine, polyenamine, polyorganosiloxane, polyester, polyamide, polyamideimide, polystyrene, polybenzoxazole precursor, polybenzoxa Sol, cellulose derivative, polyacetal, polymaleimide, styrene-maleimide-based copolymer, or poly(meth)acrylate as the main skeleton, and a polymer having a functional group reacting (crosslinking reaction) with the compound [W] Can be lifted. In addition, (meth)acrylate means an acrylate and a methacrylate. The polyenamine is a polymer having a carbon-carbon double bond at a position adjacent to the amino group of the polyamine, and examples thereof include polyeneaminoketone, polyeneaminoester, polyeneaminonitrile, polyeneaminosulfonyl, and the like.

As a polymer component, from among these, the performance (for example, liquid crystal orientation, electrical properties, mechanical strength, weather resistance, etc.) of the obtained liquid crystal element can be sufficiently high, so that polyamic acid, polyamic acid ester, polyimide, polyamine, It is preferably at least one selected from the group consisting of polyenamine, polyamide, polystyrene, poly(meth)acrylate, polymaleimide, styrene-maleimide-based copolymer, and polyorganosiloxane. Since the above-described improvement effect by compounding of the compound [W] is higher, it is preferable to include a polymer having a structural unit derived from diamine, and specifically, polyamic acid, polyamic acid ester, polyimide, polyamine, It is more preferable to contain at least one selected from the group consisting of polyenamine and polyamide.

It is preferable that the polymer component contains a polymer having a primary amino group at the terminal. In this case, the crosslinking by the compound [W] is further promoted, and the voltage retention rate of the obtained liquid crystal element can be made higher, which is preferable. The polymer having a primary amino group at the terminal is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamine, polyenamine, and polyamide, and the crosslinking reaction by compound [W] Accordingly, the polymer component is at least one selected from the group consisting of a polyamic acid, a polyamic acid ester, and a polyimide from the point that the effect of improving the liquid crystal alignment and the voltage retention rate can be increased, and that it is easy to synthesize. It is particularly preferred that it is a species.

(Polyamic acid)

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

・Tetracarboxylic acid dianhydride

Examples of the tetracarboxylic dianhydride used in the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. As specific examples of these, examples of aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and the like;

As 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 dianhydride, etc.;

As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, ethylene glycol bisanehydrotrimate, 4,4'-(hexafluoro Loisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, and the like; In addition to those mentioned respectively, the tetracarboxylic dianhydride described in Japanese Laid-Open Patent Publication No. 2010-97188 can be used. Moreover, as tetracarboxylic dianhydride, 1 type can be used individually or 2 or more types can be combined and used.

Diamine compound

As the diamine compound used in the synthesis of the polyamic acid, a known diamine compound can be used, and examples thereof include aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane, and the like. When heated, the reactivity with the compound [W] is high, the crosslinking can be further promoted, and the solubility of the polymer in a solvent can be improved, the following formulas (7-1) to (7-3) A diamine compound having a partial structure represented by each of (hereinafter also referred to as "protecting group-containing diamine") can be preferably used.

(In formula (7-1), A ²¹ is a single bond or a divalent organic group having 1 or more carbon atoms, Y ¹ is a protecting group, and R ²¹ to R ²³ are each independently a hydrogen atom or a monovalent group having 1 or more carbon atoms. M is an integer of 0 to 6. In formula (7-2), Y ² is a protecting group In formula (7-3), R ²⁴ and R ²⁵ are each independently a divalent hydrocarbon group, Y ³ is a protecting group, and "*" represents a bonding hand.)

In the above formulas (7-1) to (7-3), the protecting groups of Y ^{1 to} Y ³ are preferably groups that are desorbed by heat. For example, a carbamate protecting group, an amide protecting group, an imide protecting group And sulfonamide-based protecting groups. As the protecting group, among others, a carbamate-based protecting group is preferable, and specific examples thereof include tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, and 1,1-dimethyl-2 -Cyanoethyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, etc. are mentioned. Among these, a tert-butoxycarbonyl group is particularly preferred, from the viewpoint of high desorption property due to heat and the ability to reduce the residual amount in the film of the deprotected portion.

The monovalent organic group of R ²¹ and R ²² is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably an alkyl group or a cycloalkyl group having 1 to 10 carbon atoms.

It is preferable that the monovalent organic group of R ²³ is a monovalent alkyl group or a protecting group having 1 to 10 carbon atoms. The protecting group is preferably a carbamate-based protecting group, and a tert-butoxycarbonyl group is particularly preferable.

The divalent hydrocarbon group of R ²⁴ and R ²⁵ is preferably a C 1 to C 10 divalent chain hydrocarbon group, and more preferably a C 1 to C 10 alkanediyl group.

Examples of the divalent organic group of A ²¹ include a divalent hydrocarbon group and a group having -O-, -CO-, -COO-, and -NH- between the carbon-carbon bonds of the hydrocarbon group. A ²¹ is preferably bonded to an aromatic ring, and particularly preferably bonded to a benzene ring.

As a specific example of a protecting group-containing diamine, the compound etc. which are represented by each of following formula (d-7-1)-formula (d-7-14) are mentioned, for example.

(In the formula, TMS represents a trimethylsilyl group.)

In the case of using a protecting group-containing diamine, the ratio of use thereof is preferably 2 mol% or more, more preferably 3 to 80 mol%, and more preferably 5 to 80 mol% with respect to the total amount of the diamine compound used in the synthesis of the polymer. It is more preferable to set it as 70 mol%. Moreover, the protecting group-containing diamine may be used individually by 1 type, and may be used in combination of 2 or more types.

As the diamine used in the synthesis of the polyamic acid, in addition to the above, examples of the aliphatic diamine include metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and the like; Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and the like;

As aromatic diamine, for example, dodecanoxy-2,4-diaminobenzene, pentadecaneoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2, 4-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholesteryloxy-3, 5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid Cholestenyl, 3,5-diaminobenzoic acid ranostanyl, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 2,4-dia Mino-N,N-diallylaniline, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl) Phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid = 5ξ-cholestan-3-yl, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO- or *-OCO- (however, "*" represents a bond with X ^I 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 from 1 to 20, and d is 0 or 1. However, a and b do not become 0 at the same time.)

Side-chain diamines, such as a compound represented by, a diamine having a cinnamic acid structure in a side chain, and a compound represented by each of the following formulas (d-8-1) to (d-8-7):

p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 4,4'- Diaminobiphenyl-3,3'-dicarboxylic acid, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,6-bis(4-amino Phenoxy)hexane, bis[2-(4-aminophenyl)ethyl]hexane diacid, N,N'-bis(4-aminophenyl)-1,4-benzenediamine, N,N'-bis(4- Aminophenyl)-N,N'-dimethyl-1,4-benzenediamine, bis(4-aminophenyl)amine, bis(4-aminophenyl)methylamine, 2,6-diaminopyridine, 1,4-bis (4-aminophenyl)-piperazine, N,N'-bis(4-aminophenyl)-benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(tri Fluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylether, 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-amino Phenoxy)biphenyl, 4,4'-[4,4'-propane-1,3-diylbis(piperizine-1,4-diyl)]dianiline, 4,4'-diaminobenzanilide, 4 ,4'-diaminosylbenzene, 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, a compound represented by each of the following formulas (d-8-8) to (d-8-16) Main chain diamines such as; Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like; In addition to those mentioned respectively, the diamine described in Japanese Unexamined Patent Publication No. 2010-97188 can be used.

Synthesis of polyamic acid

Polyamic acid can be obtained by reacting the above-described tetracarboxylic dianhydride and diamine compound together with a molecular weight modifier, if necessary. The ratio of the tetracarboxylic acid dianhydride and the diamine compound used in the synthesis reaction of the polyamic acid is preferably 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic acid dianhydride with respect to 1 equivalent of the amino group of the diamine compound. . Examples of the molecular weight modifier include acid monohydrides 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 mass or less with respect to 100 parts by mass in total of the tetracarboxylic dianhydride and diamine compound to be used.

In addition, in order to obtain a polyamic acid as a polymer having a primary amino group at the terminal, (1) in the reaction of the tetracarboxylic acid dianhydride and the diamine compound, the amount of diamine compound used is higher than that of the tetracarboxylic acid dianhydride (e.g. For example, a method of reacting the monoamine compound as a molecular weight modifier (2) as a molecular weight modifier and the like can be cited as 1.1 to 1.5 molar equivalents of the amount of tetracarboxylic dianhydride used.

The synthesis reaction of the polyamic acid is preferably performed 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, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, 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 (e.g., butyl cellosolve, diethylene glycol It is preferable to use a mixture with diethyl ether, etc.). The amount (a) of the organic solvent used is preferably an amount such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50 mass% with respect to the total amount (a+b) of the reaction solution.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be provided as it is for preparation of a liquid crystal aligning agent, or may be provided for preparation of a liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution.

(Polyamic acid ester)

Polyamic acid esters are, for example, [I] a method of reacting a polyamic acid obtained by the above synthesis reaction with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester and a diamine compound, [III] tetracarboxylic acid It can be obtained by a method of reacting a diester dihalide and a diamine compound, or the like. The polyamic acid ester contained in the liquid crystal aligning agent may have only a dark acid ester structure, or may be a partial esterified product in which a dark acid structure and a dark acid ester structure coexist. Further, the reaction solution obtained by dissolving the polyamic acid ester may be provided as it is for preparation of the liquid crystal aligning agent, or after isolating the polyamic acid ester contained in the reaction solution, it may be provided for preparation of the liquid crystal aligning agent.

(Polyimide)

Polyimide can be obtained, for example, by imidizing polyamic acid synthesized as described above by dehydrating and cyclizing. Polyimide may be a complete imidide obtained by dehydrating and cyclizing all of the mental acid structures of the polyamic acid as its precursor, or a partial imide in which only a part of the mental acid structure is dehydrated and cyclized, so that the dark acid structure and the imide ring structure coexist. good. As for the polyimide used for reaction, it is preferable that its imidation ratio is 20-99%, and it is more preferable that it is 30-90%. This imidation ratio is a percentage showing the ratio of the number of imide ring structures to the sum of the number of mental acid structures of the polyimide and the number of imide ring structures. Here, a part of the imide ring may be an isoimide ring.

The dehydration cyclization of the polyamic acid is preferably performed by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration cyclization catalyst to this solution, and heating as necessary. In this method, as the dehydrating agent, an acid anhydride such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used, for example. The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the mental acid structure of the polyamic acid. As the dehydration ring closure catalyst, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, for example. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per 1 mole of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring closure reaction include organic solvents exemplified as those used for 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. The reaction solution obtained in this way containing a polyimide may be provided as it is for preparation of a liquid crystal aligning agent, or after isolating a polyimide, it may be provided for preparation of a liquid crystal aligning agent. Polyimide can also be obtained by imidization of a polyamic acid ester.

In the case of imparting liquid crystal alignment ability to an organic film formed using a liquid crystal aligning agent using a photoalignment method, it is preferable to use at least a part of the polymer component as a polymer having a photoalignable group. The photoalignable group refers to a functional group capable of imparting anisotropy to a film by photoreaction such as photoisomerization reaction, photodimerization reaction, photofreeze potential reaction, or photodecomposition reaction by light irradiation.

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 a 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, cyclobutane or a derivative thereof as a basic skeleton And a cyclobutane-containing structure to be included, a stilbene-containing group having stilbene or a derivative thereof as a basic skeleton, and a phenylbenzoate-containing group having phenylbenzoate or a derivative thereof as a basic skeleton. Among these, the photoalignable 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 structure, and a phenylbenzoate-containing group. It is preferable that it is 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 a photoalignable group is, for example, (1) a method obtained by polymerization using a monomer having a photoalignable group, (2) a polymer having an epoxy group in the side chain is synthesized, and the epoxy group-containing polymer and the photoalignable group are It can be obtained by a method of reacting carboxylic acid, or the like. The content ratio of the photoalignable group in the polymer is appropriately set according to the kind of photoalignable group so as to impart a desired liquid crystal alignment ability to the coating film. For example, in the case of a cinnamic acid structure-containing group, a polymer having a photoalignable group The content ratio of the photoalignable group is preferably 5 mol% or more, and more preferably 10 to 60 mol% with respect to the total structural units of. When the photoalignable group is a cyclobutane-containing structure, the content ratio of the photoalignable group is preferably 50% by mole or more, and more preferably 80% by mole or more with respect to all structural units of the polymer having the photoalignable group. In addition, the polymer having a photoalignable group may be used singly or in combination of two or more.

The polymer component to be contained in the liquid crystal aligning agent may be used singly or as a blend system of two or more. For example, the liquid crystal aligning agent is made to contain a 1st polymer and a 2nd polymer with higher polarity than a 1st polymer. In this case, the second polymer having high polarity is unevenly distributed in the lower layer, and the first polymer is unevenly distributed in the upper layer, which is preferable in that it is possible to cause phase separation. As a preferable aspect of the polymer component of a liquid crystal aligning agent, the following (I)-(III) is mentioned.

(I) The 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) 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 polyorganosiloxane.

(III) One of the first polymer and the second polymer is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and the other is derived from a monomer having a polymerizable unsaturated bond. A polymer having a structural unit (hereinafter, also referred to as "polymer (Q)").

(Polyorganosiloxane)

The polyorganosiloxane to be contained in the liquid crystal aligning agent can be obtained by, for example, hydrolyzing and condensing a hydrolyzable silane compound. Examples of the hydrolyzable silane compound include alkoxysilane compounds such as tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane; Nitrogen-sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-(3-cyclohexylamino)propyltrimethoxysilane ; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc. Epoxy group-containing silane compound of; 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltriethoxysilane, p-styryltri Unsaturated bond-containing alkoxysilane compounds such as methoxysilane; And trimethoxysilylpropylsuccinic anhydride. Hydrolyzable silane compounds may be used alone or in combination of two or more of these. In addition, "(meth)acryloxy" is the meaning including "acryloxy" and "methacryloxy".

The hydrolysis/condensation reaction described above is carried out by reacting one or two or more of the above-described silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. During the reaction, the ratio of water to be used is preferably 1 to 30 moles per 1 mole of the silane compound (total amount). Examples of the catalyst to be used include acids, alkali metal compounds, organic bases, titanium compounds, and zirconium compounds. The amount of the catalyst to be used varies depending on the type of catalyst, reaction conditions such as temperature, and the like, and must be appropriately set. For example, it is preferably 0.01 to 3 times mol with respect to the total amount of the silane compound. Examples of the organic solvent to be used include hydrocarbons, ketones, esters, ethers, alcohols, and the like, and among them, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The ratio of the organic solvent to be used is preferably 10 to 10,000 parts by mass with respect to 100 parts by mass in total of the silane compound used in the reaction.

The hydrolysis/condensation reaction is preferably carried out by heating with an oil bath or the like. In that case, the heating temperature is preferably 130°C or less, and the heating time is preferably 0.5 to 12 hours. After completion of the reaction, the organic solvent layer separated from the reaction solution is dried with a desiccant, if necessary, and then the solvent is removed to obtain the target polyorganosiloxane. The method for synthesizing the polyorganosiloxane is not limited to the hydrolysis/condensation reaction described above, but may be performed by, for example, a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol.

In the case where the polyorganosiloxane is a polymer having a photoalignable group, the synthesis method thereof is not particularly limited, but a polyorganosiloxane having an epoxy group in the side chain by using an epoxy group-containing silane compound in at least part of the raw material (hereinafter, `` An epoxy group-containing polyorganosiloxane") is synthesized, and then, a method of reacting an epoxy group-containing polyorganosiloxane with a carboxylic acid having a photoalignable group, etc. are mentioned. This method is simple and is preferable from the viewpoint of being able to increase the introduction rate of the photosensitive group and the liquid crystal structure. In addition, a polyorganosiloxane having a photoalignable group in the side chain may be synthesized by a reaction in which a monomer has a hydrolyzable silane compound having a photoalignable group. With respect to the polyorganosiloxane, the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably in the range of 100 to 50,000, and more preferably in the range of 200 to 10,000.

(Polymer (Q))

Examples of the monomer having a polymerizable unsaturated bond used in the synthesis of the polymer (Q) include compounds having a (meth)acryloyl group, a vinyl group, a styryl group, a maleimide group, and the like. Specific examples of such compounds include, for example, unsaturated carboxylic acids such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid: alkyl (meth)acrylate, cycloalkyl (meth)acrylate, benzyl (meth)acrylate. , (Meth)acrylate-2-ethylhexyl, (meth)acrylate trimethoxysilylpropyl, (meth)acrylate 2-hydroxyethyl, (meth)acrylate glycidyl, (meth)acrylate 3,4-epoxycyclohexyl Unsaturated carboxylic acid esters such as methyl, 3,4-epoxybutyl (meth)acrylate, and 4-hydroxybutyl glycidyl ether of acrylic acid: unsaturated polyvalent carboxylic anhydrides such as maleic anhydride: (meth)acrylic compounds such as styrene; Aromatic vinyl compounds such as methyl styrene and divinylbenzene; Conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; Maleimide group-containing compounds such as N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; And the like. In addition, when the polymer (Q) is a polymer having a photoalignable group, a compound having a photoalignable group may be used as a monomer having a polymerizable unsaturated bond. In addition, the monomers having a polymerizable unsaturated bond can be used alone or in combination of two or more.

The polymer (Q) can be obtained, for example, by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. As the polymerization initiator to be used, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy -2,4-dimethylvaleronitrile) and other azo compounds are preferred. The ratio of the polymerization initiator to be used is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of all monomers used in the reaction. The polymerization reaction is preferably performed in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like, and diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate and the like are preferable. The reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 to 36 hours. The amount (a) of the organic solvent 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 (Q), it is preferable that it is 250-500,000, and, as for the weight average molecular weight (Mw) of polystyrene conversion measured by GPC, it is more preferable that it is 500-100,000.

In the above (II) and (III) aspects, the total content ratio of polyamic acid, polyamic acid ester and polyimide sufficiently increases the film hardness of the obtained liquid crystal alignment film, and sufficiently high the liquid crystal alignment and voltage retention rate of the liquid crystal element. In terms of doing so, with respect to the total amount of the polymer components contained in the liquid crystal aligning agent, it is preferable to set it as 20 mass% or more, it is more preferable to set it as 30% mass or more, and it is still more preferable to set it as 50 to 90 mass %. In the case of imparting liquid crystal alignment ability to an organic film formed using a liquid crystal aligning agent by a photo-alignment method, a polyorganosiloxane, poly(meth)acrylate or styrene-maleimide-based copolymer is used as a polymer having a photo-aligning group By setting it as, it is preferable from the point which the alignment film which has more favorable liquid crystal aligning property is obtained.

<Compound [W]>

Next, compound [W] is demonstrated. Compound [W] is an enol ester in a ring, enol esters other than a ring, acylamide esters in a ring, acylamide esters or oxime esters other than a ring, and as a crosslinkable group, from the structure represented by the above formula (1) It has a plurality of groups in one molecule having a partial structure (hereinafter also referred to as "partial structure A") in which n arbitrary hydrogen atoms are removed (n is preferably 1 or 2).

In the formula (1), examples of the divalent organic group of A ¹ include a hydrocarbon group having 2 to 20 carbon atoms and a group having -O- between the carbon-carbon bonds of the hydrocarbon group. A ¹ is preferably a C 2 to C 20 hydrocarbon group, more preferably a C 2 to C 15 hydrocarbon group, and still more preferably a C 2 to C 10 hydrocarbon group.

As the monovalent organic group of R ¹ to R ^{7 in} the above formulas (2-1) to (2-5), a monovalent hydrocarbon group having 1 to 10 carbon atoms, and -O between the carbon-carbon bonds of the hydrocarbon group And groups having -. The monovalent organic group of R ¹ to R ⁷ is preferably a monovalent hydrocarbon group, more preferably a C 1 to C 12 monovalent hydrocarbon group, further preferably a C 1 to C 10 alkyl group or a C 6 to C 12 carbon number. Is a monovalent aromatic hydrocarbon group, and particularly preferably an alkyl group or a phenyl group having 1 to 6 carbon atoms.

It is preferable that the compound [W] is a compound in which a plurality of partial structures A is bonded directly or via a linking group. The linking group is preferably a hydrocarbon group having 1 to 30 carbon atoms or a group having -O-, -S-, -NH-, or -CO- between the carbon-carbon bonds of the hydrocarbon group. n is preferably 1 or 2. From the viewpoint of the high degree of freedom of setting the compound and the reactivity with the polymer component, it is preferable that X ¹ is a group represented by each of the formulas (2-3) to (2-5).

As a preferable specific example of partial structure A, partial structures represented by each of the following formulas (3-1) to (3-9) are mentioned. In addition, the following formula (3-1) and formula (3-2) correspond to the case where X ¹ in the formula (1) is the formula (2-1), and the following formula (3-3) is Corresponding to the case where X ¹ in formula (1) is the above formula (2-2), and the following formulas (3-4), (3-5) and (3-6) are in the above formula (1) This corresponds to the case where X ¹ is the above formula (2-3). In addition, the following formula (3-7) and formula (3-8) correspond to the case where X ¹ in the formula (1) is the formula (2-4), and the following formula (3-9) is It corresponds to the case of equation (2-5).

(In formulas (3-1) to (3-9), R ⁵¹ to R ⁷¹ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 24 carbon atoms. However, R ⁵¹ to R Any one of ⁵⁴ , any one of R ⁵⁵ to R ⁵⁷ , any one of R ⁶⁰ to R ⁶² , any one of R ⁶³ and R ⁶⁴ , any one of R ⁶⁶ to R ⁶⁸ , and R ⁶⁹ and Any one of R ⁷⁰ is a bonding hand. A plurality of R ⁵¹ to R ⁷¹ in one molecule each independently have the above definition. "*" represents a bonding hand.)

In the formulas (3-1) to (3-9), the monovalent organic group of R ⁵¹ to R ⁷¹ is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, and a monovalent chain hydrocarbon group having 1 to 10 carbon atoms It is more preferable that it is a group or a C6-C10 monovalent aromatic hydrocarbon group, it is still more preferable that it is a C1-C10 alkyl group or a phenyl group, and it is especially preferable that it is a C1-C5 alkyl group or a phenyl group.

As a specific example of the compound [W], the compound etc. which are represented by each of following formula (b-1)-formula (b-11) are mentioned, for example.

(In the formula, "Ph" is a phenyl group.)

The content ratio of the compound [W] is 0.001 parts by mass or more with respect to 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent from the viewpoint of sufficiently obtaining the effect of improving the liquid crystal orientation and voltage retention of the obtained liquid crystal element. It is preferable, and it is more preferable to use it as 0.003 mass part or more, and it is still more preferable to use it as 0.005 mass part or more. In addition, the content ratio of the compound [W] is, from the viewpoint of suppressing a decrease in electrical properties due to the compound [W] remaining in the film after post-baking, with respect to 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent, It is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 parts by mass or less. Further, as the compound [W], one type may be used alone, or two or more types may be used in combination.

<Other additive components>

The liquid crystal aligning agent of this disclosure may contain other additive components other than the compound [W] as needed. Other additive components are not particularly limited as long as the effect of the present disclosure is not impaired. Specific examples of other additive components include compounds different from compound [W] and having a crosslinkable group (hereinafter, also referred to as ``crosslinkable group-containing compound''), functional silane compounds, antioxidants, metal chelate compounds, curing accelerators, and interfaces. An activator, a filler, a dispersing agent, a photosensitizer, a solvent, etc. are mentioned. The blending ratio of the other additive components can be appropriately selected according to each compound within a range that does not impair the effects of the present disclosure.

(Crosslinkable group-containing compound)

The crosslinkable group-containing compound may be used in order to further improve the adhesion of the liquid crystal aligning film to the substrate and the reliability of the liquid crystal element. As a crosslinkable group-containing compound, for example, at least one crosslinkable group selected from the group consisting of a cyclocarbonate group, an epoxy group, an isocyanate group, a block isocyanate group, an oxetanyl group, a trialkoxysilyl group, and a polymerizable unsaturated bond group. The compounds which have, etc. are mentioned. Examples of the polymerizable unsaturated bond group include a (meth)acryloyl group, an ethylenic carbon-carbon double bond, a vinylphenyl group, a vinyloxy group (CH ₂ =CH-O-), a vinylidene group, a maleimide group, and the like, From the point of high reactivity by light or heat, a cyclocarbonate group, an epoxy group, or a (meth)acrylic group is preferred.

As a specific example of the crosslinkable group-containing compound, for example, 1,6-hexanediol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl- Aminomethylcyclohexane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 1,6-hexanedioldi(meth)acrylate, pentaerythritol tri( The compounds represented by each of meth)acrylate and following formula (11-1)-formula (11-10), etc. are mentioned. Further, the crosslinkable group-containing compound can be used alone or in combination of two or more.

When the crosslinkable group-containing compound is blended into the liquid crystal aligning agent, the blending ratio thereof is the effect of the blending of the compound [W], that is, even when the post-baking temperature is set to a low temperature (for example, 170°C or less) From the viewpoint of sufficiently advancing and obtaining the effect of obtaining a liquid crystal element having a sufficiently high liquid crystal alignment property and a sufficiently high voltage retention rate, it is preferably 150 parts by mass or less, based on 100 parts by mass of the compound [W] contained in the liquid crystal aligning agent. It is more preferable to set it as parts or less, and it is still more preferable to set it as 100 mass parts or less. When the compound [W] and the crosslinkable group-containing compound are used in combination, the blending ratio of the crosslinkable group-containing compound is 100 parts by mass of the total amount of the compound [W] and the crosslinkable group-containing compound. On the other hand, it is preferable to set it as an amount as 10 parts by mass or less, more preferably 0.001 to 5 parts by mass, and even more preferably 0.001 to 1 part by mass.

<solvent component>

The liquid crystal aligning agent of this disclosure is prepared as a polymer composition in the form of a solution in which a polymer component, a compound [W], and a component to be optionally blended as necessary 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.

As the solvent component of the liquid crystal aligning agent of the present disclosure, a solvent having high solubility and leveling properties of a polymer (hereinafter, also referred to as ``first solvent''), a solvent having good wet spreadability (hereinafter, referred to as ``second solvent''), and And these mixed solvents.

As a specific example of the solvent, as the first solvent, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide , 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 Amide, 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, methylmethoxypropionate , Ethyl ethoxy propionate, isoamyl propionate, isoamyl isobutylate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, diisopentyl ether, and the like, respectively. In addition, a solvent may be used individually by these 1 type, and may mix and use 2 or more types.

The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity and volatility, but is preferably 1 to 10 It is a range of mass%. When the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes insufficient, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes excessive, making it difficult to obtain a good liquid crystal aligning film, and further, the viscosity of the liquid crystal aligning agent increases, and the coating property tends to decrease.

≪Liquid crystal alignment film and liquid crystal element≫

The liquid crystal aligning film of this disclosure is formed by the liquid crystal aligning agent prepared above. In addition, the liquid crystal element of the present disclosure includes a liquid crystal aligning film formed using the liquid crystal aligning agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), 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. The liquid crystal element can be manufactured by a method including the following steps 1 to 3, for example. In Step 1, the substrates used are different depending on the desired operation mode. Process 2 and process 3 are common to each operation mode.

<Step 1: Formation of coating film>

First, a liquid crystal aligning agent is applied on a substrate, and a coating film is preferably formed on the substrate by heating the coated surface. Examples of the substrate include glass such as float glass and soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin) can be used. As a transparent conductive film formed on one side of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG in the United States), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc. may be used. I can. When manufacturing a TN-type, STN-type or VA-type liquid crystal element, 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 element, a substrate on which electrodes patterned in a comb-tooth shape are formed and a counter substrate on which electrodes are not formed are used. The 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, pre-heating (prebaking) is preferably performed for the purpose of preventing liquid flow of the applied liquid crystal aligning agent. 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 thermally imidizing the dark acid structure in the polymer component. The firing temperature at this time (post-baking temperature) is preferably 80 to 250°C, more preferably 80 to 200°C. Moreover, the liquid crystal aligning agent using the compound [W] as a crosslinking agent is preferable from the point which can obtain a liquid crystal element exhibiting favorable liquid crystal aligning property and voltage retention even when post-baking at a relatively low temperature of 170°C or lower. The post-baking time is preferably 5 to 200 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 µm.

<Step 2: Orientation treatment>

When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, a treatment (alignment treatment) for imparting liquid crystal alignment ability to the coating film formed in step 1 is performed. Accordingly, the alignment ability of the liquid crystal molecules is imparted to the coating film, thereby forming a liquid crystal alignment film. As the alignment treatment, a rubbing treatment in which the coating film formed on the substrate is rubbed in a predetermined direction with a roll wound with a cloth made of, for example, nylon, rayon, cotton, etc., or liquid crystal alignment on the coating film by irradiating light to the coating film formed on the substrate. A photoalignment treatment or the like that imparts the ability can be used. On the other hand, in the case of manufacturing a vertical alignment (VA) type liquid crystal element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film. good. A liquid crystal alignment film suitable for a vertical alignment type liquid crystal element can also be suitably used for a PSA type liquid crystal element.

The light irradiation for light alignment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, and heating the coating film in at least any of the pre-baking process and the post-baking process. It can be carried out by a method of irradiating the coating film in the middle, or the like. As the radiation to be irradiated 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 ultraviolet rays containing light of a wavelength of 200 to 400 nm. When the radiation is polarized light, linearly polarized light or partial polarized light may be used. When the radiation to be used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or a combination of these may be performed. In the case of non-polarized radiation, the irradiation direction is oblique.

As a light source to be 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 radiation dose 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 substrate surface is, for example, water, an organic solvent (e.g., methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) Alternatively, a treatment for cleaning or a treatment for heating the substrate may be performed using a mixture thereof.

<Step 3: Construction of liquid crystal cell>

As described above, two substrates on which a liquid crystal alignment film is formed are prepared, and a liquid crystal cell is produced by disposing a liquid crystal between the two substrates arranged opposite to each other. To manufacture a liquid crystal cell, for example, two substrates are opposed to each other through a gap so that the liquid crystal alignment film faces each other, and the periphery of the two substrates is bonded with a sealing agent, and the cell is surrounded by the surface of the substrate and the sealing agent. A method of sealing the injection hole by injecting and filling liquid crystal into the gap, a method using an ODF method, and the like. As the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, a nematic liquid crystal is preferable. In the PSA mode, after construction of the liquid crystal cell, a treatment of irradiating light to the liquid crystal cell is performed in a state in which a voltage is applied between conductive films of a pair of substrates.

In the case of manufacturing a PSA type liquid crystal element, a liquid crystal cell is constructed in the same manner as above except that a photopolymerizable compound is injected or dropped together with the liquid crystal between a pair of substrates having a conductive film. Thereafter, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage to be applied here can be, for example, DC or AC of 5 to 50 V. As the irradiated light, for example, ultraviolet rays and visible rays including light of a wavelength of 150 to 800 nm can be used, but ultraviolet rays including light of a wavelength of 300 to 400 nm are preferable. As a light source of irradiation light, 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. The irradiation amount of light is preferably 1,000 to 200,000 J/m 2, and more preferably 1,000 to 100,000 J/m 2.

Subsequently, if necessary, a polarizing plate is bonded to the outer surface of the liquid crystal cell to obtain a liquid crystal element. As a polarizing plate, a polarizing plate made of the H film itself or a polarizing plate in which a polarizing film called "H film" in which iodine was absorbed while stretching and orienting polyvinyl alcohol was sandwiched by a cellulose acetate protective film may be mentioned.

The liquid crystal element of the present disclosure can be effectively applied to various applications, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smart phones, It can be applied to various display devices such as various monitors, liquid crystal TVs, and information displays, as well as dimming films and retardation films. In addition, the liquid crystal element of the present disclosure is suitably used also for a liquid crystal element using a dye as a colorant for a color filter layer. Here, as the dye, a known dye that can be used for a liquid crystal element can be used.

Example

Hereinafter, although it demonstrates concretely by Example, the content of this disclosure is not limited to the following Example.

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

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

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

GPC column: manufactured by Tosoh Corporation, TSKgelGRCXLII

Mobile phase: N,N-dimethylformamide solution containing lithium bromide and phosphoric acid

Column temperature: 40°C

Flow rate: 1.0 mL/min

Pressure: 68kgf/㎠

<Polymer solution viscosity>

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

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

(Tetracarboxylic acid dianhydride)

(Diamine compound)

(Compound [W])

(Other crosslinking agents)

<Synthesis of Compound [W]>

[Synthesis Examples 1-1 to 1-8]

Compounds (BL-1) to (BL-8) were each synthesized according to the method described in the following documents.

Compound (BL-1): Endo-enol ester; M. Ueda, M. Yabuuchi, Y. Imai, J. Polym. Sci., Polym. Chem. Ed,, 15, 323 (1977)

Compound (BL-2): Endo-acyl imidate; M. Ueda, Y. Imai, J. Polym. Sci., Polym. Chem. Ed,, 17, 1163 (1979)

Compound (BL-3): Endo-acyl imidate; M. Ueda, K. Kino, Y. Imai, J. Polym. Sci., Polym. Chem. Ed., 13, 659 (1975)

Compound (BL-4): Endo-enol ester; M. Ueda, T. Takahashi, Y. Imai, J. Polym. Sci., Polym. Chem. Ed,, 15, 2641 (1977)

Compound (BL-5): Exo-enol ester; M. Ueda, T. Takahashi, Y. Imai, J. Polym. Sci., Polym. Chem. Ed,, 14 591 (1976)

Compound (BL-6): Endo-acyl imidate; M. Ueda, K. Kino, K. Yamaki, Y. Imai, J. Polym. Sci., Polym. Chem. Ed,, 16, 155 (1978)

Compound (BL-7): Oxime ester; M. Ueda, H. Hazome, Y. Imai, J. Polym. Sci., Polym. Chem. Ed., 14, 1127 (1976)

Compound (BL-8): Exo-acyl omidate; M. Ueda, S. Kanno, Y. Imai, J. Polym. Sci., Polvm.

<Synthesis of polymer>

[Synthesis Example 2-1: Synthesis of polyamic acid]

In a 100 mL two-necked flask under nitrogen, 50 mol parts of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 50 mol parts of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride are N-methyl-2-pi It dissolved in rolidone (NMP), and then 10 mole parts of compound (DA-1) and 90 mole parts of compound (DA-2) were added, and the reaction was carried out at 60° C. for 4 hours to obtain 20 mass of polymer (P-1). A solution containing% was obtained. A small amount of the obtained polyamic acid solution was aliquoted, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 1020 mPa·s.

[Synthesis Examples 2-2 to 2-14]

Polyamic acid (respectively referred to as polymers (P-2) to (P-14)) by performing the same operation as in Synthesis Example 2-1, except that the kind and amount of the monomers to be used were changed as shown in Table 1 below. A solution containing was obtained. In addition, "-" in Table 1 means that the compound of the corresponding column was not used.

[Synthesis Example 2-15]

In a 100 mL two necked flask under nitrogen, 100 mol parts of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (compound (AH-2)) was dissolved in N-methyl-2-pyrrolidone (NMP), and continued Then, (E)-4-(3-(2,4-diaminopheneoxy)-3-oxopropa-1-en-1-yl)phenyl 4-(4,4,4-trifluoro moiety 100 mol parts of oxy)benzoate was added, and reaction was carried out at 60°C for 24 hours to obtain a solution containing 30% by mass of the polymer (P-15). A small amount of the obtained polyamic acid solution was aliquoted, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by mass was 640 mPa·s.

[Synthesis Example 3-1: Synthesis of polyorganosiloxane]

Polymer (ES-1) was synthesized according to the following Scheme 1.

To a 1000 ml three-necked flask, 90.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were added and mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then reacted at 80°C for 6 hours while mixing under reflux. After completion of the reaction, the organic layer was taken out, washed with 0.2% by mass ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure. An appropriate amount of methyl isobutyl ketone was added to obtain a 50 mass% solution of the polyorganosiloxane (E-1) having an epoxy group.

To a 500 ml three-necked flask, 26.69 g (0.3 mol equivalent) of side chain carboxylic acid (ca-1) shown below, 2.00 g of tetrabutylammonium bromide, 80 g of a solution containing polyorganosiloxane (E-1), and methyl isobutyl ketone 239 g was added, and it stirred at 110 degreeC for 4 hours. After cooling to room temperature, the liquid separation washing operation was repeated 10 times with distilled water. Thereafter, the organic layer was recovered, concentration and NMP dilution were repeated twice with a rotary evaporator to obtain a 15 mass% NMP solution of the polymer (ES-1) intermediate. To 50 g of the intermediate solution, 0.45 g (0.1 mol equivalent) of trimellitic anhydride was added, and then prepared so that the solid content concentration became 10% by mass using NMP, and then stirred at room temperature for 4 hours to obtain a polymer (ES-1). An NMP solution was obtained.

[Synthesis Example 3-2]

In Synthesis Example 3-1, in place of the side chain carboxylic acid (ca-1), except for using the side chain carboxylic acid (ca-2) shown below, by performing the same operation as in Synthesis Example 3-1, the polymer ( An NMP solution containing ES-2) was obtained.

[Synthesis Example 4-1: Synthesis of styrene-maleimide-based copolymer]

1. Synthesis of compound (MI-1)

Compound (MI-1) was synthesized according to Scheme 2 below.

(E)-3-(4-((4-(4,4,4-trifluorobutoxy)benzoyl)oxy)phenyl)acrylic acid 11.8g, thionyl chloride 20g, N 0.01 g of N-dimethylformamide was added, followed by stirring at 80°C for 1 hour. After that, excess thionyl chloride was removed by a diaphragm pump, and 100 g of tetrahydrofuran was added to obtain solution A. To a 500 mL three-neck flask in which a stirrer was newly placed, 5.67 g of 4-hydroxyphenylmaleimide, 200 g of tetrahydrofuran, and 12.1 g of triethylamine were added, followed by ice bathing. Solution A was dripped there, and it stirred at room temperature for 3 hours. The reaction solution was reprecipitated with 800 mL of water, and the obtained white solid was vacuum-dried to obtain 13.3 g of a compound (MI-1).

2. Synthesis of polymer

Under nitrogen, in a 100 mL two-necked flask, as a polymerization monomer, 5.00 g (8.6 mmol) of the compound (MI-1) obtained above, 0.64 g (4.3 mmol) of 4-vinylbenzoic acid, 4-(2,5-dioxo- 3-pyrrolin-1-yl) benzoic acid 2.82 g (13.0 mmol) and 4- (glycidyloxymethyl) styrene 3.29 g (17.2 mmol), 2,2'-azobis (2,4) as a radical polymerization initiator -Dimethylvaleronitrile) 0.31g (1.3mmol), 2,4-diphenyl-4-methyl-1-pentene 0.52g (2.2mmol) as a chain transfer agent, and tetrahydrofuran 25ml as a solvent were added, and at 70℃ It polymerized for 5 hours. After reprecipitation in n-hexane, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain the target polymer (StMI-1). 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 4-2]

In Synthesis Example 4-1, a polymer (StMI-2) was performed in the same manner as in Synthesis Example 4-1 except that the maleimide compound (MI-2) shown below was used instead of the compound (MI-1). ). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 35000, and the molecular weight distribution Mw/Mn was 2.

<Manufacture and evaluation of a rubbing FFS type liquid crystal display device>

[Example 1]

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

To a solution containing 100 parts by mass of the polymer (P-1) obtained in Synthesis Example 2-1, 200 parts by mass of the polymer (P-11) obtained in Synthesis Example 2-11, 5 parts by mass of the compound (BL-1), Then, NMP and butyl cellosolve (BC) were added as a solvent to obtain a solution having a solvent composition of NMP/BC=50/50 (mass ratio) and a solid content concentration of 4.0% by mass. Liquid crystal aligning agent (AL-1) was prepared by filtering this solution with a filter of 1 micrometers pore diameter.

2. Evaluation of applicability

The liquid crystal aligning agent (AL-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 in an oven at 230° C. where nitrogen was substituted for 30 By heating for a minute (post-baking), a coating film having an average film thickness of 0.1 µm was formed. This coating film was observed under a microscope at a magnification of 100 and 10 to examine nonuniformity in film thickness and the presence or absence of pinholes. The evaluation was ``good (A)'' when neither of the film thickness non-uniformity nor the pinhole was observed even when observed with a 100-fold microscope, and at least any of the film thickness non-uniformity and the pinhole was observed under a 100-fold microscope. Under the microscope, when neither the film thickness unevenness nor the pinhole was observed, it was set as ``possible (B)'', and when at least any of the film thickness unevenness and pinholes were clearly observed under a 10-fold microscope, it was set as ``defective (C)''. . In this example, neither film thickness non-uniformity nor pinholes were observed even under a microscope of 100 times, and the coatability was evaluated as "good (A)".

3. Evaluation of film hardness

On the glass substrate, the liquid crystal aligning agent (AL-1) prepared above was applied using a spinner, and prebaked for 1 minute on a hot plate at 80°C. Then, in an oven in which the inside of the chamber was purged with nitrogen, it was heated at 150°C for 1 hour to form a coating film having a thickness of 0.1 μm. About the obtained coating film, pencil hardness (surface hardness) was evaluated in conformity with JIS-K5400. When the pencil hardness was 4H or more was evaluated as ``A'', 2H or 3H was evaluated as ``B'', H was evaluated as ``C'', and the pencil hardness was less than H as ``D'', the pencil hardness of this liquid crystal aligning film was It was an evaluation of "A".

4. Manufacture of rubbing horizontal liquid crystal display device (1)

The liquid crystal aligning agent (AL-1) prepared above was applied onto the transparent electrode surface of the transparent electrode glass substrate made of an ITO film using a spinner, and prebaked on a hot plate at 80° C. for 1 minute. Then, 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. With respect to this coating film, a rubbing treatment was performed at a roll rotation speed of 400 rpm, a stage movement speed of 3 cm/sec, and a hair foot press-fitting length of 0.1 mm by a rubbing machine having a roll wound with a rayon cloth. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then dried in a 100°C clean oven for 10 minutes to obtain a substrate having a liquid crystal aligning film. By repeating this series of operations, a pair (two) of substrates having a liquid crystal aligning film was created.

After applying an epoxy resin adhesive containing an aluminum oxide sphere of 3.5 μm in diameter to the outer periphery of the surface having one liquid crystal aligning film of the substrate by screen printing, the respective liquid crystal aligning film surfaces were overlapped with each other so as to face each other, and the adhesive was applied. Cured. Next, after filling the nematic liquid crystal (MLC-6221, manufactured by Merck) between the pair of substrates from the liquid crystal injection port, sealing the liquid crystal injection port with an acrylic photocurable adhesive, and bonding polarizing plates to both sides of the outer side of the substrate, A horizontal rubbing liquid crystal display element A was manufactured.

5. Manufacture of rubbing horizontal liquid crystal display device (2)

Except for changing the post-baking temperature from 230°C to 150°C, a horizontal rubbing liquid crystal display element B was manufactured by performing the same operation as in 4. above.

6. Evaluation of liquid crystal orientation

For each of the rubbing horizontal liquid crystal display elements A and B manufactured above, the presence or absence of an abnormal domain in the change in contrast when the voltage of 5 V is turned ON/OFF (applied/released) is checked with an optical microscope. By observing, the case where there is no abnormal domain was set as "A", the case where there was an abnormal domain in part was set as "B", and the case where there was an abnormal domain as a whole was evaluated as "C", and liquid crystal orientation was evaluated. As a result, in this Example, the liquid crystal orientation was "A" for both the element A with the post-baking temperature set at 230°C and the element B at 150°C.

7. Evaluation of voltage retention rate (VHR)

For each of the rubbing horizontal liquid crystal display elements A and B manufactured above, a voltage of 5 V was applied with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage retention rate after 167 milliseconds from the release of application was measured. The measuring device used VHR-1 manufactured by Toyo Technica. At this time, "S" when the voltage retention rate is 98% or more, "A" when 95% or more and less than 98%, "B" when 80% or more and less than 95%, and "C" when 50% or more and less than 80% , When it is less than 50%, it was set as "D". As a result, in this example, the voltage retention rate was evaluated as "A" for both the element A with the post-baking temperature set at 230°C and the element B set at 150°C.

[Examples 5, 8 and 9]

Except having changed the compounding composition as shown in following Table 2, it prepared by the same solid content concentration as Example 1, and obtained the liquid crystal aligning agent, respectively. In addition, each liquid crystal aligning agent was used in the same manner as in Example 1 to evaluate the coating properties and film hardness of the liquid crystal aligning agent, and rubbing horizontal liquid crystal display elements A and B were prepared in the same manner as in Example 1. Various evaluations were made. Their results are shown in Table 3 below.

<Production and evaluation of optical FFS type liquid crystal display device>

[Example 2]

1. Preparation of liquid crystal aligning agent (AL-2)

A liquid crystal aligning agent (AL-2) was prepared in the same solvent composition and solid content concentration as in Example 1, except that the kind and amount of the polymer and crosslinking agent to be used were changed as shown in Table 2 below.

2. Evaluation of applicability

Except using the liquid crystal aligning agent instead of (AL-1) (AL-2), it carried out similarly to the said Example 1, and evaluated the coating property. As a result, it was "A" in this Example.

3. Evaluation of film hardness

The film hardness was evaluated in the same manner as in Example 1 except that (AL-2) was used instead of (AL-1) as the liquid crystal aligning agent. As a result, it was "A" in this Example.

4. Manufacturing of optical FFS type liquid crystal display device (1)

The liquid crystal aligning agent (AL-2) prepared above was prepared on each side of a glass substrate in which a flat electrode, an insulating layer, and a comb electrode were laminated on one side in this order and a counter glass substrate on which no electrode was formed. , It applied using a spinner, and heated (prebaked) for 1 minute on a hot plate at 80°C. After that, drying (post-baking) was performed for 30 minutes in an oven at 230° C. in which nitrogen was substituted inside the chamber to form a coating film having an average thickness of 0.1 μm. The surface of the coating film was irradiated with 1,000 J/m 2 of ultraviolet rays including a 254 nm bright line linearly polarized using an Hg-Xe lamp from the normal direction of the substrate to perform photo-alignment treatment, thereby forming a liquid crystal alignment film on the substrate.

Subsequently, with respect to the pair of substrates having the liquid crystal alignment film, after screen printing coating an epoxy resin adhesive containing an aluminum oxide ball having a diameter of 5.5 μm by leaving a liquid crystal injection hole on the edge of the surface on which the liquid crystal alignment film was formed, the polarization axis at the time of light irradiation The substrates were stacked and pressed together so that the projection direction onto the substrate surface was antiparallel, and the adhesive was thermally cured at 150 DEG C for 1 hour. Next, after filling a nematic liquid crystal (MLC-7028, manufactured by Merck) between a pair of substrates from a liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of liquid crystal injection, this was heated at 120° C. and then slowly cooled to room temperature to prepare a liquid crystal cell. Next, the optical FFS type liquid crystal display element is made by bonding a polarizing plate to both outer sides of the substrate so that the polarization directions thereof are orthogonal to each other and at an angle of 90° to the projection direction of the optical axis of the ultraviolet rays of the liquid crystal alignment film to the substrate surface. A was prepared.

5. Manufacturing of optical FFS type liquid crystal display device (2)

Except for changing the post-baking temperature from 230°C to 150°C, an optical FFS type liquid crystal display element B was manufactured by performing the same operation as in 4. above.

6. Evaluation of liquid crystal orientation

About the optical FFS type liquid crystal display elements A and B manufactured above, it carried out similarly to the said Example 1, and evaluated the liquid crystal orientation. As a result, in this Example, the liquid crystal orientation of both optical FFS type liquid crystal display elements A and B was "A".

7. Evaluation of voltage retention rate (VHR)

About the optical FFS type liquid crystal display elements A and B manufactured above, it carried out similarly to the said Example 1, and evaluated the voltage retention rate. As a result, in this Example, the voltage retention rate of both the optical FFS type liquid crystal display elements A and B was evaluation of "A".

[Examples 10 to 12]

Except having changed the compounding composition as shown in following Table 2, it prepared by the same solid content concentration as Example 1, and obtained the liquid crystal aligning agent, respectively. Further, using each of the liquid crystal aligning agents in the same manner as in Example 1, evaluation of the coatability and film hardness of the liquid crystal aligning agent was performed, and in the same manner as in Example 2, optical FFS type liquid crystal display elements A and B were prepared. Various evaluations were made. Their results are shown in Table 3 below.

<Manufacture and evaluation of VA type liquid crystal display device>

[Example 3]

1. Preparation of liquid crystal aligning agent (AL-3)

A liquid crystal aligning agent (AL-3) was prepared in the same solvent composition and solid content concentration as in Example 1, except that the type and amount of the polymer and crosslinking agent to be used were changed as shown in Table 2 below.

2. Evaluation of applicability

Except using the liquid crystal aligning agent instead of (AL-1) (AL-3), it carried out similarly to the said Example 1, and evaluated the coatability. As a result, it was "A" in this Example.

3. Evaluation of film hardness

The film hardness was evaluated in the same manner as in Example 1 except that (AL-3) was used instead of (AL-1) as the liquid crystal aligning agent. As a result, it was "A" in this Example.

4. Fabrication of VA type liquid crystal display device (1)

The liquid crystal aligning agent (AL-3) prepared above was applied onto the transparent electrode surface of the transparent electrode glass substrate made of an ITO film using a spinner, and prebaked on a hot plate at 80° C. for 1 minute. Then, 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. By repeating this operation, a pair (two) of the substrates having a liquid crystal alignment film was created.

After applying an epoxy resin adhesive containing an aluminum oxide sphere of 3.5 μm in diameter to the outer periphery of the surface having one liquid crystal aligning film of the substrate by screen printing, the respective liquid crystal aligning film surfaces were overlapped with each other so as to face each other, and the adhesive was applied. Cured. Subsequently, after filling the negative liquid crystal (MLC-6608, manufactured by Merck) between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photocurable adhesive, and the polarizing plates are bonded to both sides of the outer side of the substrate. A type liquid crystal display element A was manufactured.

5. Manufacture of VA type liquid crystal display device (2)

A VA-type liquid crystal display element B was produced by performing the same operation as in 4. above except that the post-baking temperature was changed from 230°C to 150°C.

6. Evaluation of liquid crystal orientation

About the VA type liquid crystal display elements A and B manufactured above, it carried out similarly to the said Example 1, and evaluated liquid crystal orientation. As a result, in this Example, the liquid crystal orientation of both VA type liquid crystal display elements A and B was "A".

7. Evaluation of voltage retention rate (VHR)

About the VA-type liquid crystal display elements A and B manufactured above, it carried out similarly to the said Example 1, and evaluated the voltage retention rate. As a result, in this Example, the voltage retention rate of both VA type liquid crystal display elements A and B was evaluation of "A".

[Example 4]

Except having changed the compounding composition as shown in following Table 2, it prepared by the same solid content concentration as Example 1, and obtained the liquid crystal aligning agent. Moreover, using the obtained liquid crystal aligning agent, it carried out similarly to Example 1, and evaluated the coatability and film hardness of a liquid crystal aligning agent, It carried out similarly to Example 3, and produced VA type liquid crystal display elements A, B, and various evaluations Did. The results are shown in Table 3 below.

<Production and evaluation of PSA type liquid crystal display device>

[Example 6]

1. Preparation of liquid crystal aligning agent (AL-6)

A liquid crystal aligning agent (AL-6) was prepared in the same solvent composition and solid content concentration as in Example 1, except that the type and amount of the polymer and crosslinking agent to be used were changed as shown in Table 2 below.

2. Evaluation of applicability

Except using (AL-6) instead of (AL-1) as a liquid crystal aligning agent, it carried out similarly to the said Example 1, and evaluated the coatability. As a result, it was "A" in this Example.

3. Evaluation of film hardness

The film hardness was evaluated in the same manner as in Example 1 except that (AL-6) was used instead of (AL-1) as the liquid crystal aligning agent. As a result, it was "A" in this Example.

4. Preparation of liquid crystal composition

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

5. Manufacturing of PSA type liquid crystal display device (1)

The liquid crystal aligning agent (AL-6) prepared above was applied on each electrode surface of two glass substrates each having a conductive film made of an ITO electrode by using a liquid crystal alignment film printer (manufactured by Nippon Shashin Insats Co., Ltd.) , After heating (prebaking) for 2 minutes on a hot plate at 80°C to remove the solvent, heating (post-baking) for 10 minutes on a hot plate at 230°C to form a coating film having an average film thickness of 0.06 μm. These coating films were subjected to ultrasonic cleaning in ultrapure water for 1 minute, and then dried in a 100°C clean oven for 10 minutes to obtain a pair (two) of substrates having a liquid crystal alignment film. In addition, the pattern of the electrode used is the same kind as the electrode pattern in the PSA mode.

Subsequently, an epoxy resin adhesive containing an aluminum oxide sphere having a diameter of 5.5 μm was applied to the outer periphery of the surface of one of the pair of substrates having a liquid crystal aligning film, and then the liquid crystal aligning film faces were overlapped with each other so as to face each other, followed by pressing the adhesive. Cured. Subsequently, after filling the liquid crystal composition LC1 prepared above between the pair of substrates from the liquid crystal injection port, the liquid crystal cell was manufactured by sealing the liquid crystal injection port with an acrylic photocurable adhesive. After that, an AC 10V with a frequency of 60 Hz was applied between the conductive films of the liquid crystal cell, while the liquid crystal was driven, using an ultraviolet irradiation device using a metal halide lamp as a light source, ultraviolet rays were irradiated with an irradiation dose of 100,000 J/m2. Investigated. In addition, this irradiation amount is a value measured using a photometer measured based on a wavelength of 365 nm. Thereafter, 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 optical axis of the liquid crystal aligning film is at an angle of 45° to the projection direction of the ultraviolet ray to the substrate surface. Was prepared.

6. PSA type liquid crystal display device manufacturing (2)

Except for changing the post-baking temperature from 230°C to 150°C, a PSA type liquid crystal display element B was manufactured by performing the same operation as in 5. above.

7. Evaluation of liquid crystal orientation

About the PSA type liquid crystal display elements A and B manufactured above, it carried out similarly to Example 1, and evaluated the liquid crystal orientation. As a result, in this Example, the liquid crystal orientation of both the PSA type liquid crystal display elements A and B was "A".

8. Evaluation of voltage retention rate (VHR)

About the PSA type liquid crystal display elements A and B manufactured above, it carried out similarly to Example 1, and evaluated the voltage retention rate. As a result, in this Example, the voltage preservation factor in both the PSA type liquid crystal display elements A and B was evaluation of "A".

[Examples 7, 13, 14]

Except having changed the compounding composition as shown in following Table 2, it prepared by the same solid content concentration as Example 1, and obtained the liquid crystal aligning agent, respectively. Further, using the obtained liquid crystal aligning agent, while evaluating the coatability and film hardness of the liquid crystal aligning agent in the same manner as in Example 1, PSA type liquid crystal display elements A and B were produced in the same manner as in Example 6, Various evaluations were performed in the same manner as in Example 1. The evaluation results are shown in Table 3 below.

<Manufacture and evaluation of vertical optical liquid crystal display device>

[Example 15]

1. Preparation of liquid crystal aligning agent (AL-15)

A liquid crystal aligning agent (AL-15) was prepared in the same solvent composition and solid content concentration as in Example 1, except that the type and amount of the polymer and crosslinking agent to be used were changed as shown in Table 2 below.

2. Evaluation of applicability

Except using the liquid crystal aligning agent instead of (AL-1) (AL-15), it carried out similarly to the said Example 1, and evaluated the coating property. As a result, it was "A" in this Example.

3. Evaluation of film hardness

The film hardness was evaluated in the same manner as in Example 1 except that (AL-15) was used instead of (AL-1) as the liquid crystal aligning agent. As a result, it was "A" in this Example.

4. Manufacturing of vertical optical liquid crystal display device (1)

The liquid crystal aligning agent (AL-15) prepared above was applied onto the transparent electrode surface of the transparent electrode glass substrate made of an ITO film using a spinner, and prebaked on a hot plate at 80° C. for 1 minute. Then, 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. Subsequently, on the surface of the coating film, 1,000 J/m 2 of polarized ultraviolet rays including a 313 nm bright line were irradiated from a direction inclined at 40° from the substrate normal using an Hg-Xe lamp and a Glen Taylor prism to impart liquid crystal alignment ability. . The same operation was repeated to create a pair (two) of substrates having a liquid crystal aligning film.

After applying an epoxy resin adhesive containing an aluminum oxide ball having a diameter of 3.5 μm by screen printing to the outer periphery of the surface having one liquid crystal aligning film among the substrates, the liquid crystal aligning film surfaces of the pair of substrates were opposed to each other, It pressed so that the direction of projection of the optical axis of ultraviolet rays onto the substrate surface was antiparallel, and the adhesive was thermally cured at 150°C over 1 hour. Next, after filling the gap between the substrates from the liquid crystal injection port with a negative liquid crystal (MLC-6608, manufactured by Merck), the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation during liquid crystal injection, it was heated at 130°C and then slowly cooled to room temperature. Next, by bonding a polarizing plate to both outer sides of the substrate so that the polarization directions thereof are orthogonal to each other, and at an angle of 45° to the direction of projection of the optical axis of the ultraviolet rays of the liquid crystal aligning film onto the substrate surface, A was prepared.

5. Manufacturing of vertical optical liquid crystal display device (2)

Except for changing the post-baking temperature from 230°C to 150°C, an optical vertical liquid crystal display element B was manufactured by performing the same operation as in 4. above.

6. Evaluation of liquid crystal orientation

About the light vertical liquid crystal display elements A and B manufactured above, it carried out similarly to the said Example 1, and evaluated the liquid crystal orientation. As a result, in this Example, the liquid crystal orientation in both the light vertical liquid crystal display elements A and B was "A".

7. Evaluation of voltage retention rate (VHR)

About the optical vertical liquid crystal display element manufactured above, it carried out similarly to the said Example 1, and evaluated the voltage retention factor. As a result, in this Example, the voltage preservation factor in both the light vertical liquid crystal display elements A and B was an evaluation of "A".

[Examples 16 to 25 and Comparative Examples 1 to 6]

Except having changed the compounding composition as shown in following Table 2, it prepared by the same solid content concentration as Example 1, and obtained the liquid crystal aligning agent, respectively. Further, using each of the liquid crystal aligning agents in the same manner as in Example 1, evaluating the coatability and film hardness of the liquid crystal aligning agent, and in the same manner as in Example 15, the light vertical liquid crystal display elements A and B were prepared. Various evaluations were made. Their results are shown in Table 3 below. In addition, in Table 2, "-" means that the compound of the corresponding column was not used.

As shown in Table 3, in Examples 1 to 25 using the liquid crystal aligning agent containing the compound [W] as a crosslinking agent, except for Example 14, all coating properties are evaluations of "A", and Example 14 is "B It was an evaluation of ". In addition, Examples 1 to 25 were good also about the liquid crystal orientation and voltage retention of the obtained liquid crystal display element, and were evaluations of "S", "A" or "B". Particularly, in Example 17 using the diamine-rich polymer (P-12), when the post-baking temperature was set to 150°C, the liquid crystal orientation was evaluated as "S", and was particularly excellent. On the other hand, in Example 22 using the acid anhydride-rich polymer (P-13), the liquid crystal orientation was evaluated as "B" when the post-baking temperature was 150°C.

In contrast, in Comparative Examples 1 not containing a crosslinking agent and Comparative Examples 2 to 6 containing only a crosslinking agent different from the compound [W], when the post-baking temperature was set at 230°C, the liquid crystal orientation and the voltage retention rate were “A”. Or it was the evaluation of "B", but when the post-baking temperature was 150 degreeC, it was the evaluation of "C" or "B", and it was a result inferior to an Example.

From these results, it was found that the liquid crystal aligning film and the liquid crystal element formed using the liquid crystal aligning agent containing the compound [W] are excellent in coatability, film hardness, liquid crystal aligning property, and voltage retention.

Claims (9)

A liquid crystal aligning agent containing a polymer component and a heterocycle-containing compound having two or more partial structures in which n (n is an integer of 1 or more) hydrogen atoms have been removed from the structure represented by the following formula (1).

(In formula (1), X ¹ is any of the groups represented by the following formulas (2-1) to (2-5); A ¹ is a divalent organic group, and is bonded to another ring structure to A condensed ring may be formed together with other ring structures; a plurality of A ¹ and X ¹ in one molecule each independently have the above definition)

(In formulas (2-1) to (2-5), R ¹ to R ⁷ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 or more carbon atoms; Formula (2-3) and formula "*" in (2-5) indicates that it is a bond with an oxygen atom in formula (1)) The method of claim 1,
The said heterocycle-containing compound is a liquid crystal aligning agent which is a compound which has any of the partial structures represented by each of following formula (3-1)-formula (3-9) in 1 molecule.

(In formulas (3-1) to (3-9), R ⁵¹ to R ⁷¹ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 24 carbon atoms; provided that R ⁵¹ to R Any one of ⁵⁴ , any one of R ⁵⁵ to R ⁵⁷ , any one of R ⁶⁰ to R ⁶² , any one of R ⁶³ and R ⁶⁴ , any one of R ⁶⁶ to R ⁶⁸ , and R ⁶⁹ and Any one of R ⁷⁰ is a bonding hand; A plurality of R ⁵¹ to R ⁷¹ in one molecule each independently have the above definition; "*" indicates that it is a bonding hand) The method according to claim 1 or 2,
The said polymer component contains a polymer which has a partial structure represented by each of following formula (7-1)-formula (7-3), The liquid crystal aligning agent.

(In formula (7-1), A ²¹ is a single bond or a divalent organic group having 1 or more carbon atoms, Y ¹ is a protecting group, and R ²¹ to R ²³ are each independently a hydrogen atom or a monovalent group having 1 or more carbon atoms. Device; m is an integer of 0 to 6; in formula (7-2), Y ² is a protecting group; in formula (7-3), R ²⁴ and R ²⁵ are each independently a divalent hydrocarbon group, Y ³ is a protecting group; "*" indicates that it is a bonding hand) The method according to any one of claims 1 to 3,
The said polymer component contains a polymer which has a primary amino group at a terminal, The liquid crystal aligning agent. The method according to any one of claims 1 to 4,
The said polymer component contains at least 1 type selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. A liquid crystal aligning film formed using the liquid crystal aligning agent in any one of Claims 1-5. A liquid crystal element comprising the liquid crystal alignment film according to claim 6. The liquid crystal aligning agent according to any one of claims 1 to 5 is applied to each substrate surface in a pair of substrates, and the liquid crystal aligning ability is imparted by irradiating light to the applied substrate surfaces to form a liquid crystal aligning film. Forming process,
A process of constructing a liquid crystal cell by arranging a pair of substrates on which the liquid crystal alignment layer is formed so that the coated surfaces of the substrate face each other through a liquid crystal layer
Containing, the manufacturing method of a liquid crystal element. A step of applying the liquid crystal aligning agent according to any one of claims 1 to 5 on each of the conductive films of a pair of substrates having a conductive film, and
A step of constructing a liquid crystal cell by arranging a pair of substrates coated with the liquid crystal aligning agent so that the coated surfaces of the substrate face each other through a liquid crystal layer;
A process of irradiating light to the liquid crystal cell while applying a voltage between the conductive layers
Containing, the manufacturing method of a liquid crystal element.