CN111556981B

CN111556981B - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal element, and method for manufacturing liquid crystal element

Info

Publication number: CN111556981B
Application number: CN201980007410.XA
Authority: CN
Inventors: 冈田敬; 村上嘉崇
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 2018-04-05
Filing date: 2019-02-19
Publication date: 2023-07-07
Anticipated expiration: 2039-02-19
Also published as: TWI815876B; TW201943844A; KR102404080B1; KR20200098659A; JPWO2019193855A1; CN111556981A; JP6981542B2; WO2019193855A1

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal aligning film, a liquid crystal element and a manufacturing method of the liquid crystal element, wherein the liquid crystal aligning agent has good coating property on a substrate, high film hardness even when the film is formed at a low temperature, and liquid crystal element with excellent liquid crystal alignment property and voltage retention rate can be obtained. The liquid crystal aligning agent contains a polymer component and a heterocyclic compound having a partial structure in which n (n is an integer of 1 or more) hydrogen atoms are removed from a structure represented by formula (1) in a molecule of 2 or more. In the formula (1), X ¹ is-CR ¹ ＝CR ² -and the like. A is that ¹ Is a divalent organic group, and may be bonded to other ring structures to form a condensed ring together with the other ring structures. A molecule inner part is greater than a plurality of A ¹ X is X ¹ Each independently having the definition.

Description

Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal element, and method for manufacturing liquid crystal element

Cross reference to related applications

The present application is based on japanese application No. 2018-73138 filed on publication No. 5 of 2018, 4, and the disclosure of which is incorporated herein by reference.

Technical Field

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

Background

The liquid crystal element includes a liquid crystal alignment film having a function of aligning liquid crystal molecules in a predetermined direction. In general, the liquid crystal alignment film is formed on a substrate by applying a liquid crystal alignment agent, which is obtained by dissolving a polymer component in an organic solvent, to the surface of the substrate, preferably by heating. Further, rubbing treatment or photo-alignment treatment is optionally performed on the organic film formed on the substrate using the liquid crystal alignment agent, thereby imparting liquid crystal alignment ability.

In recent years, a large-screen and high-definition liquid crystal television has been mainly used, and a smart phone or a tablet personal computer (tablet personal computer, tablet PC) and the like, the demand for higher quality of liquid crystal elements has been further increased than ever. Against such a background, various liquid crystal aligning agents have been proposed in order to improve the performance of a liquid crystal alignment film and to make various characteristics of a liquid crystal element (for example, liquid crystal alignment property, voltage holding ratio, residual image characteristics, and the like) more excellent (for example, refer to patent documents 1 to 3).

Patent document 1 discloses a liquid crystal aligning agent containing polyimide and an epoxy compound having a nitrogen atom (for example, N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane, 1, 3-bis (N, N ' -diglycidyl aminomethyl) cyclohexane, and the like). According to the liquid crystal aligning agent described in patent document 1, a liquid crystal alignment film having excellent liquid crystal alignment properties and capable of suppressing display failure due to rubbing damage can be obtained. Patent document 2 discloses a liquid crystal aligning agent containing a polyamide acid or polyimide, and a compound containing an imide bond and 2 or more epoxy groups (for example, monoallyldiglycidyl isocyanuric acid, triglycidyl isocyanuric acid, and the like). Patent document 3 discloses a polyfunctional epoxy compound having 2 or more 3, 4-epoxycyclohexane rings and containing polyamide acid or polyimide in a liquid crystal aligning agent. In the case of forming a liquid crystal alignment film using a liquid crystal alignment agent containing a crosslinking agent, the crosslinking is generally performed by heating (post baking) at the time of film formation, thereby promoting hardening of the film.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 10-333153

Patent document 2: japanese patent laid-open No. 2007-139949

Patent document 3: japanese patent laid-open publication 2016-170409

Disclosure of Invention

Problems to be solved by the invention

In order to sufficiently harden the film and to increase the film hardness by adding the crosslinking agent, it is desirable to heat the film at a high temperature (for example, 200 ℃ or higher). However, when heating at a high temperature is required for forming a liquid crystal alignment film, there are cases where defects such as restrictions on materials of the substrate are generated and the application of a film base material as a substrate of a liquid crystal element is restricted. 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 limited when heating at the time of film formation is required at a high temperature. On the other hand, if the hardening of the film is insufficient, the film hardness is insufficient, and there is a concern that the liquid crystal alignment property or the voltage holding ratio is lowered.

In addition, when the solubility of the polymer component is reduced by the addition of the crosslinking agent or the crosslinking agent is precipitated in the alignment agent, the coatability of the liquid crystal alignment agent to the substrate is deteriorated. In addition, there is a concern that the liquid crystal orientation and voltage holding ratio of the obtained liquid crystal element decrease, or that the product yield decreases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal aligning agent comprising: the coating property on the substrate is good, the film hardness is high even when the film is formed at a low temperature, and a liquid crystal element with excellent liquid crystal orientation and voltage retention rate can be obtained.

Technical means for solving the problems

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

[1] A liquid crystal aligning agent comprising: a polymer component; and a heterocyclic compound having a partial structure in which n (n is an integer of 1 or more) hydrogen atoms are removed from a structure represented by the following formula (1) in one molecule.

[ chemical 1]

(in the formula (1), X ¹ Is any one of the groups represented by the following formulas (2-1) to (2-5). A is that ¹ Is a divalent organic group, and may be bonded to other ring structures to form a condensed ring together with the other ring structures. Multiple A in one molecule ¹ X is X ¹ Each independently having the definition. )

[ chemical 2]

(in the formulae (2-1) to (2-5), R ¹ ～R ⁷ Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 or more carbon atoms. The "×" in the formula (2-3) and the formula (2-5) represents a bond to an oxygen atom in the formula (1). )

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

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

[4] A method of manufacturing a liquid crystal element, comprising: a step of applying the liquid crystal aligning agent of [1] to each substrate surface of a pair of substrates, and irradiating the applied substrate surfaces with light, thereby imparting liquid crystal aligning ability and forming a liquid crystal alignment film; and a step of constructing a liquid crystal cell by disposing a pair of substrates on which the liquid crystal alignment film is formed, via a liquid crystal layer, so that the coated surfaces of the substrates face each other.

[5] A method of manufacturing a liquid crystal element, comprising: a step of applying the liquid crystal aligning agent of [1] to the respective conductive films of a pair of substrates having the conductive films; a step of constructing a liquid crystal cell by disposing a pair of substrates coated with the liquid crystal aligning agent through a liquid crystal layer so that the coated surfaces of the substrates face each other; and a step of irradiating the liquid crystal cell with light in a state where a voltage is applied between the conductive films.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the liquid crystal aligning agent of the present disclosure, a liquid crystal element excellent in liquid crystal alignment property and voltage holding ratio can be obtained even when heating is performed at a low temperature (for example, a temperature of 170 ℃ or lower) at the time of film formation. In addition, the liquid crystal aligning agent of the present disclosure is excellent in coating property to a substrate, and thus can suppress a decrease in product yield.

Detailed Description

Liquid crystal aligning agent

The liquid crystal aligning agent of the present disclosure contains a polymer component and an additive component. The additive component contains a heterocyclic compound having a partial structure in which n (n is an integer of 1 or more) hydrogen atoms are removed from the structure represented by the formula (1) in one molecule (hereinafter, also 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 needed will be described.

In the present specification, the term "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The term "chain hydrocarbon group" refers to a linear hydrocarbon group and a branched hydrocarbon group each having a chain structure alone, and having no cyclic structure in the main chain. Wherein, the resin can be saturated or unsaturated. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group having a structure containing only alicyclic hydrocarbon as a ring structure, and not containing an aromatic ring structure. The hydrocarbon group does not need to be composed of only alicyclic hydrocarbon, and may have a chain structure in a part thereof. The term "aromatic hydrocarbon group" means a hydrocarbon group having an aromatic ring structure as a ring structure. The aromatic ring structure may be a chain structure or an alicyclic hydrocarbon structure.

< Polymer component >)

The main skeleton of the polymer component contained in the liquid crystal aligning agent is not particularly limited as long as it is crosslinked by the compound [ W ]. Specific examples of the polymer component include polymers having a polyamide acid, a polyamide acid ester, a polyimide, a polyamine, a polyalkenamine (polyoxamine), a polyorganosiloxane, a polyester, a polyamide, a polyamideimide, a polystyrene, a polybenzoxazole precursor, a polybenzoxazole, a cellulose derivative, a polyacetal, a polymaleimide, a styrene-maleimide copolymer, or a poly (meth) acrylate as a main skeleton and having a functional group that reacts (cross-links) with the compound [ W ]. Further, (meth) acrylate means acrylate and methacrylate. The polyalkene amine is a polymer having a carbon-carbon double bond at the ortho position of the amino group of the polyamine, and examples thereof include: polyalkenyl ketone, polyalkenyl ester, polyalkenyl nitrile, polyalkenyl sulfonyl, and the like.

Among these, at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamine, polyalkenamine, polyamide, polystyrene, poly (meth) acrylate, polymaleimide, styrene-maleimide copolymer, and polyorganosiloxane is preferable in terms of sufficiently improving the performance (e.g., liquid crystal alignment property, electrical characteristics, mechanical strength, weather resistance, etc.) of the obtained liquid crystal element. In terms of the higher improvement effect by the compound [ W ], it is preferable to include a polymer having a structural unit derived from a diamine, and more specifically, at least one selected from the group consisting of a polyamic acid, a polyamic acid ester, a polyimide, a polyamine, a polyalkene amine, and a polyamide.

The polymer component is preferably a polymer containing a primary amino group at the end. In this case, it is preferable in terms of further promoting the crosslinking by the compound [ W ] and further improving the voltage holding ratio of the obtained liquid crystal element. 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, polyalkenylamine, and polyamide, and at least a part of the polymer component is particularly preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide in terms of further improving the effect of improving the liquid crystal alignment and voltage holding ratio by the compound [ W ] and ease of synthesis.

(Polyamic acid)

The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound.

Tetracarboxylic dianhydride

Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include: aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, and the like. Specific examples of these include aliphatic tetracarboxylic dianhydrides: 1,2,3, 4-butanetetracarboxylic acid dianhydride, and the like;

Examples of the alicyclic tetracarboxylic dianhydride include: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1, 3-dimethyl-1, 2,3, 4-cyclobutanetetracarboxylic dianhydride, 2,3, 5-tricarboxyl cyclopentylacetic anhydride, 5- (2, 5-dioxotetrahydrofuran-3-yl) -3a,4,5,9 b-tetrahydronaphtho [1,2-c ] furan-1, 3-dione, 5- (2, 5-dioxotetrahydrofuran-3-yl) -8-methyl-3 a,4,5,9 b-tetrahydronaphtho [1,2-c ] furan-1, 3-dione, 2,4,6, 8-tetracarboxylic bicyclo [3.3.0] octane-2:4, 6:8-dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, and the like; examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4'- (hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol bistrimethylene anhydride, and 4,4' -carbonyldiphthalic anhydride, and in addition to these, tetracarboxylic dianhydride described in japanese patent application laid-open No. 2010-97188 can be used. Further, the tetracarboxylic dianhydride may be used singly or in combination of two or more.

Diamine compound

As the diamine compound used for the synthesis of the polyamic acid, a known diamine compound can be used, and examples thereof include: aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. In terms of the high reactivity with the compound [ W ] upon heating and further promotion of crosslinking and the improvement of the solubility of the polymer in a solvent, diamine compounds having partial structures represented by the following formulae (7-1) to (7-3) (hereinafter, also referred to as "diamine containing a protecting group") may be preferably used.

[ chemical 3]

(in the formula (7-1), A ²¹ Is a single bond or a divalent organic group having 1 or more carbon atoms, Y ¹ R is a protecting group ²¹ ～R ²³ Each independently represents a hydrogen atom or a monovalent organic group having 1 or more carbon atoms. m is an integer of 0 to 6. In the formula (7-2), Y ² Is a protecting group. In the formula (7-3), R ²⁴ R is R ²⁵ Each independently is a divalent hydrocarbon group, Y ³ Is a protecting group. "×" indicates a bond. )

In the formulas (7-1) to (7-3), Y ¹ ～Y ³ The protecting group of (2) is preferably a group that is released by heat, and examples thereof include: urethane-based protecting groups, amide-based protecting groups, imide-based protecting groups, sulfonamide-based protecting groups, and the like. Among them, preferred is a urethane-based protecting group, and specific examples thereof include: t-butoxycarbonyl, benzyloxycarbonyl, 1-dimethyl-2-haloethyloxycarbonyl, 1-dimethyl-2-cyanoethyloxycarbonyl, 9-fluorenylmethyloxycarbonyl, allyloxycarbonyl, 2- (trimethylsilyl) ethoxycarbonyl and the like. Among these, tert-butoxycarbonyl is particularly preferred in terms of high releasability by heat and further reduction in the amount of deprotected portions remaining in the film.

R ²¹ R is R ²² The monovalent organic group of (2) is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably an alkyl group or cycloalkyl group having 1 to 10 carbon atoms.

R ²³ The monovalent organic group of (2) is preferably a monovalent alkyl group having 1 to 10 carbon atoms or a protecting group. The protecting group is preferably a carbamateThe acid ester protecting group is particularly preferably t-butoxycarbonyl.

R ²⁴ R is R ²⁵ The divalent hydrocarbon group of (2) is preferably a divalent chain hydrocarbon group having 1 to 10 carbon atoms, more preferably an alkanediyl group having 1 to 10 carbon atoms.

As A ²¹ Examples of the divalent organic group of (2) include: divalent hydrocarbon groups having-O-between carbon-carbon bonds of said hydrocarbon groups-CO-, -COO-, -NH-, and the like. A is that ²¹ Preferably bonded to an aromatic ring, particularly preferably bonded to a benzene ring.

Specific examples of the diamine containing a protecting group include compounds represented by the following formulae (d-7-1) to (d-7-14).

[ chemical 4]

(wherein TMS represents trimethylsilyl (trimethylsilyl))

When the diamine containing a protecting group is used, the proportion thereof is preferably 2 mol% or more, more preferably 3 to 80 mol%, and still more preferably 5 to 70 mol% based on the total amount of diamine compounds used for the synthesis of the polymer. Further, the diamine containing a protecting group may be used singly or in combination of two or more.

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

Examples of the aromatic diamine include: dodecyloxy-2, 4-diaminobenzene, pentadecyloxy-2, 4-diaminobenzene, hexadecyloxy-2, 4-diaminobenzene, octadecyloxy-2, 4-diaminobenzene, pentadecyloxy-2, 5-diaminobenzene, octadecyloxy-2, 5-diaminobenzene, cholestanoxy-3, 5-diaminobenzene, cholestenoxy-3, 5-diaminobenzene, cholestanoxy-2, 4-diaminobenzene, cholestenoxy-2, 4-diaminobenzene, 3, 5-diaminobenzoate cholestanoyl ester, 3, 5-diaminobenzoate, 3, 6-bis (4-aminobenzoyloxy) cholestane, 3, 6-bis (4-aminophenoxy) cholestane, 2, 4-diamino-N, N-diallylaniline, 4- (4' -trifluoromethoxybenzoyloxy) cyclohexyl-3, 5-diamino-2, 4-diaminobenzene, 1-diamino-benzoate, 1-bis (4-methyl) cholestanoyl ester, 3, 5-bis (4-amino-methyl) benzoate, 3-bis (4-amino-phenyl) and 1-bis (4-amino-phenylmethyl) phenyle

[ chemical 5]

(in the formula (E-1), X ^I X is X ^II Each independently is a single bond, -O-, -COO-, or-OCO- (wherein "+" means and X) ^I Binding bond of (2), R ^I Is alkanediyl having 1 to 3 carbon atoms, R ^II Is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1. Wherein a and b do not both become 0. )

A side chain diamine such as a compound represented by the following formula (d-8-1) to formula (d-8-7), a diamine having a cinnamic acid structure in a side chain, or the like:

p-phenylenediamine, 4 '-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4' -diaminoazobenzene, 3, 5-diaminobenzoic acid, 4 '-diaminobiphenyl-3, 3' -dicarboxylic acid, 1, 5-bis (4-aminophenoxy) pentane, 1, 2-bis (4-aminophenoxy) ethane, 1, 6-bis (4-aminophenoxy) hexane, bis [2- (4-aminophenyl) ethyl ] adipic acid, N '-bis (4-aminophenyl) -1, 4-phenylenediamine, N' -bis (4-aminophenyl) -N, N '-dimethyl-1, 4-phenylenediamine, bis (4-aminophenyl) amine, bis (4-aminophenyl) methylamine, 2, 6-diaminopyridine, 1, 4-bis- (4-aminophenyl) -piperazine, N, N' -bis (4-aminophenyl) -benzidine, 2 '-dimethyl-4, 4' -diaminobiphenyl, 2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl, 4 '-diaminodiphenyl ether 2, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 2-bis (4-aminophenyl) hexafluoropropane, 4' - (phenylenediisopropylidene) diphenylamine, 1, 4-bis (4-aminophenoxy) benzene, and main chain diamines such as 4,4 '-bis (4-aminophenoxy) biphenyl, 4' - [4,4 '-propane-1, 3-diylbis (piperidine-1, 4-diyl) ] diphenylamine, 4' -diaminobenzanilide, 4 '-diaminostilbene, 4' -diaminodiphenylamine, 1, 3-bis (4-aminophenylethyl) urea, 1, 3-bis (4-aminobenzyl) urea, 1, 4-bis (4-aminophenyl) -piperazine, N- (4-aminophenylethyl) -N-methylamine, and compounds represented by the following formulae (d-8-8) to (d-8-16), respectively; examples of the diaminoorganosiloxane include 1, 3-bis (3-aminopropyl) -tetramethyldisiloxane, and diamines described in JP-A2010-97188 may be used in addition to these.

[ chemical 6]

[ chemical 7]

Synthesis of Polyamic acid

The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride and the diamine compound as described above, together with a molecular weight regulator as needed. The ratio of the tetracarboxylic dianhydride to the diamine compound to be used in the synthesis reaction of the polyamic acid is preferably a ratio of 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic dianhydride to 1 equivalent of the amino group of the diamine compound. Examples of the molecular weight regulator include: acid monoanhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, and the like; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The ratio of the molecular weight regulator is preferably 20 parts by mass or less based on 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine compound used.

Further, in order to obtain a polymer having a primary amino group at the terminal of a polyamic acid, there may be mentioned: (1) A method in which the amount of the diamine compound used is increased in the reaction between the tetracarboxylic dianhydride and the diamine compound as compared with the tetracarboxylic dianhydride (for example, 1.1 to 1.5 molar equivalents of the amount of the tetracarboxylic dianhydride used); (2) And a method of reacting the monoamine compound as a molecular weight regulator.

The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent. The reaction temperature in this case is preferably-20 to 150℃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 the like. Particularly preferred organic solvents are preferably selected from the group consisting of N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethylsulfoxide, γ -butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol and halogenated phenols, or a mixture of one or more of these solvents with other organic solvents (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount (a) of the organic solvent to be used is preferably such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by mass based on the total amount (a+b) of the reaction solution.

As described above, a reaction solution in which the polyamic acid is dissolved can be obtained. The reaction solution can be directly used for preparing the liquid crystal aligning agent, or the polyamic acid contained in the reaction solution can be separated and then used for preparing the liquid crystal aligning agent.

(Polyamic acid ester)

The polyamic acid ester can be obtained, for example, by the following method or the like: [I] a method of reacting a polyamic acid obtained by the synthesis reaction with an esterifying agent; [ II ] a method of reacting a tetracarboxylic acid diester with a diamine compound; [ III ] A method for reacting a tetracarboxylic acid diester dihalide with a diamine compound. The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which the amic acid structure and the amic acid ester structure coexist. Furthermore, the reaction solution obtained by dissolving the polyamic acid ester may be directly used for preparing a liquid crystal aligning agent, or the polyamic acid ester contained in the reaction solution may be separated and then used for preparing the liquid crystal aligning agent.

(polyimide)

Polyimide can be obtained, for example, by dehydrating and ring-closing a polyamic acid synthesized as described above and imidizing the same. The polyimide may be a full imide compound obtained by dehydrating and ring-closing the whole of the amic acid structure of the polyamic acid which is a precursor thereof, or may be a partial imide compound obtained by dehydrating and ring-closing only a part of the amic acid structure and simultaneously combining the amic acid structure and the imide ring structure. The polyimide used in the reaction preferably has an imidization ratio of 20% to 99%, more preferably 30% to 90%. The imidization rate represents the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of the polyimide as a percentage. Here, a part of the imide ring may be an isopolyimide ring.

The dehydrating ring closure of the polyamic acid is preferably performed by the following method: the polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydrating ring-closing catalyst are added to the solution and heated as necessary. In the above method, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles based on 1 mole of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 moles based on 1 mole of the dehydrating solvent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include organic solvents exemplified as users used in the synthesis of polyamic acid. The reaction temperature of the dehydration ring-closure reaction is preferably 0℃to 180 ℃. The reaction time is preferably 1.0 to 120 hours. The polyimide-containing reaction solution thus obtained may be directly used for the preparation of a liquid crystal aligning agent, or may be used for the preparation of a liquid crystal aligning agent after the polyimide is separated. Polyimide can also be obtained by imidization of polyamic acid esters.

In the case of imparting liquid crystal aligning ability to an organic film formed using a liquid crystal aligning agent by using a photo-alignment method, it is preferable that at least a part of the polymer component is a polymer having a photo-alignment group. The photo-alignment group refers to a functional group capable of imparting anisotropy to a film by a photoreaction such as a photoisomerization reaction, a photodimerization reaction, a photofries rearrangement (photo Fries rearrangement) reaction, or a photodecomposition reaction by light irradiation.

Specific examples of the light-directing group include: an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof 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, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, a stilbene-containing group containing stilbene or a derivative thereof as a basic skeleton, a phenylbenzoate-containing group containing phenylbenzoate or a derivative thereof as a basic skeleton, and the like. Among these, the photo-alignment 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 phenyl benzoate-containing group, and is preferably a cinnamic acid structure-containing group or a cyclobutane-containing structure in terms of high sensitivity to light and easiness of introduction into the polymer.

The polymer having a photo-alignment group can be obtained, for example, by the following method: (1) A method obtained by polymerization using a monomer having a photo-alignment group; (2) A method of synthesizing a polymer having an epoxy group in a side chain and reacting the epoxy group-containing polymer with a carboxylic acid having a photo-alignment group. The content of the photo-alignment groups in the polymer is appropriately set according to the type of the photo-alignment groups so as to impart a desired liquid crystal aligning ability to the coating film, and for example, in the case of groups having a cinnamic acid structure, the content of the photo-alignment groups is preferably 5 mol% or more, more preferably 10 mol% to 60 mol% with respect to all constituent units of the polymer having the photo-alignment groups. When the photo-alignment group has a structure containing cyclobutane, the content of the photo-alignment group is preferably 50 mol% or more, more preferably 80 mol% or more, with respect to all constituent units of the polymer having the photo-alignment group. Further, the polymer having a photo-alignment group may be used singly or in combination of two or more.

The polymer component contained in the liquid crystal aligning agent may be one alone or may be a blend (blend) of two or more kinds. For example, the liquid crystal aligning agent contains a first polymer and a second polymer having a higher polarity than the first polymer. In this case, the second polymer having high polarity is biased to exist in the lower layer, and the first polymer is biased to exist in the upper layer, so that phase separation can occur. Preferred modes of the polymer component of the liquid crystal aligning agent include the following (I) to (III).

(I) The first polymer and the second polymer are in the form of a polymer 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 polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and the other polymer is in the form of 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 polymer is a polymer having a structural unit derived from a monomer having a polymerizable unsaturated bond (hereinafter, also referred to as "polymer (Q)").

(polyorganosiloxane)

The polyorganosiloxane contained in the liquid crystal aligning agent can be obtained, for example, by hydrolyzing/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-mercaptopropyl triethoxysilane, mercaptomethyl triethoxysilane, 3-aminopropyl trimethoxysilane, and N- (3-cyclohexylamino) propyl trimethoxysilane; epoxy group-containing silane compounds such as 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, and 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane; an alkoxysilane compound having an unsaturated bond such as 3- (meth) acryloxypropyl trimethoxysilane, 3- (meth) acryloxypropyl methyl dimethoxysilane, 3- (meth) acryloxypropyl methyl diethoxysilane, vinyltriethoxysilane, or p-styryl trimethoxysilane; trimethoxysilylpropyl succinic anhydride, and the like. One or a combination of two or more of these hydrolyzable silane compounds may be used alone. Furthermore, "(meth) acryloyloxy" means "acryloyloxy" and "methacryloyloxy".

The hydrolysis/condensation reaction is carried out by reacting one or two or more of the silane compounds described above with water, preferably in the presence of an appropriate catalyst and an organic solvent. When the reaction is carried out, the water is used in a proportion of 1 mol to 30 mol, preferably 1 mol to 1 mol of the silane compound (total amount). Examples of the catalyst used include: acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds, and the like. The amount of the catalyst to be used may be appropriately set depending on the kind of the catalyst, the reaction conditions such as the temperature, etc., and is preferably 0.01 to 3 times by mol based on the total amount of the silane compounds. Examples of the organic solvent used include hydrocarbons, ketones, esters, ethers, and alcohols, and among these, water-insoluble or poorly water-soluble organic solvents are preferably used. The ratio of the organic solvent is preferably 10 to 10,000 parts by mass based on 100 parts by mass of the total silane compounds used in the reaction.

The hydrolysis/condensation reaction is preferably performed by heating in an oil bath or the like, for example. In this case, the heating temperature is preferably 130℃or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction, the organic solvent layer separated from the reaction solution is dried by a drying agent as needed, and the solvent is removed, whereby the target polyorganosiloxane can be obtained. The method for synthesizing the polyorganosiloxane is not limited to the hydrolysis/condensation reaction, and may be carried out, for example, by a method in which a hydrolyzable silane compound is reacted in the presence of oxalic acid and an alcohol.

In the case where the polyorganosiloxane is a polymer having a photo-alignment group, the method of synthesis thereof is not particularly limited, and the following methods and the like are exemplified: at least a part of the raw materials is synthesized using an epoxy group-containing silane compound, and an epoxy group-containing polyorganosiloxane (hereinafter, also referred to as "epoxy group-containing polyorganosiloxane") is reacted with a carboxylic acid having a photo-alignment group. The method is simple and convenient, and is preferable in that the introduction rate of the photosensitive base and the liquid crystal structure can be improved. In addition, by a reaction in which a hydrolyzable silane compound having a photo-alignment group is contained in a monomer, a polyorganosiloxane having a photo-alignment group in a side chain can be synthesized. The weight average molecular weight (Mw) of the polyorganosiloxane in terms of polystyrene as measured by gel permeation chromatography (Gel Permeation Chromatography, GPC) is preferably in the range of 100 to 50,000, more preferably in the range of 200 to 10,000.

(Polymer (Q))

Examples of the monomer having a polymerizable unsaturated bond used for 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 a compound include: unsaturated carboxylic acids such as (meth) acrylic acid, α -ethacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid: unsaturated carboxylic acid esters such as alkyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trimethoxysilyl propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 3, 4-epoxybutyl (meth) acrylate, and 4-hydroxybutyl glycidyl acrylate: unsaturated polycarboxylic acid anhydrides such as maleic anhydride: and (meth) acrylic compounds; aromatic vinyl compounds such as styrene, methylstyrene 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; etc. In the case where the polymer (Q) is a polymer having a photo-alignment group, a compound having a photo-alignment group may be used as the monomer having a polymerizable unsaturated bond. Further, the monomer having a polymerizable unsaturated bond may be used singly 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. The polymerization initiator used is preferably an azo compound such as 2,2' -azobis (isobutyronitrile), 2' -azobis (2, 4-dimethylvaleronitrile), or 2,2' -azobis (4-methoxy-2, 4-dimethylvaleronitrile). The polymerization initiator is preferably used in a proportion of 0.01 to 30 parts by mass based on 100 parts by mass of the total monomers used in the reaction. The polymerization is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include: alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like, preferably diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, and the like. The reaction temperature is preferably 30 to 120℃and the reaction time is preferably 1 to 36 hours. The amount (a) of the organic solvent to be used is preferably an amount of 0.1 to 60 mass% based on the total amount (a+b) of the reaction solution. The weight average molecular weight (Mw) of the polymer (Q) in terms of polystyrene as measured by GPC is preferably 250 to 500,000, more preferably 500 to 100,000.

In the modes (II) and (III), the total content of the polyamic acid, the polyamic acid ester, and the polyimide is preferably 20 mass% or more, more preferably 30 mass% or more, and still more preferably 50 mass% to 90 mass% with respect to the total amount of the polymer components contained in the liquid crystal aligning agent, in terms of sufficiently improving the film hardness of the obtained liquid crystal alignment film and sufficiently increasing the liquid crystal alignment property and the voltage holding ratio of the liquid crystal element. In the case where a liquid crystal aligning ability is imparted to an organic film formed using a liquid crystal aligning agent by a photo-alignment method, an alignment film having a more favorable liquid crystal aligning property can be obtained by using a polyorganosiloxane, a poly (meth) acrylate or a styrene-maleimide copolymer as a polymer having a photo-alignment group.

< Compound [ W ] >

Next, the compound [ W ] will be described. The compound [ W ] is a cyclic enol ester, a cyclic exoenol ester, a cyclic acyl amide ester, a cyclic exoacyl amide ester or an oxime ester, and has a group having a plurality of partial structures (hereinafter, also referred to as "partial structures A") each having n (n is preferably 2) arbitrary hydrogen atoms removed from the structure represented by the formula (1) in one molecule as a crosslinkable group.

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

R in the formulas (2-1) to (2-5) ¹ ～R ⁷ Examples of the monovalent organic group(s) include: monovalent hydrocarbon groups having 1 to 10 carbon atoms, groups having-O-between carbon-carbon bonds of the hydrocarbon groups, and the like. R is R ¹ ～R ⁷ The monovalent organic group of (2) is preferably a monovalent hydrocarbon group, more preferably a hydrocarbon group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Compound [ W]Preferably, the partial structure A is directly or via a linking groupA plurality of bonded compounds. The linking group is preferably a hydrocarbon group having 1 to 30 carbon atoms or having-O-between carbon-carbon bonds of said hydrocarbon radical-S-, -NH-, -CO-. X is a group of compounds having a high degree of freedom in setting and reactivity of polymer components ¹ Preferably, the groups represented by the above formulas (2-3) to (2-5) are each represented by the following formula.

As a preferred specific example of the partial structure A, there may be mentioned partial structures represented by the following formulas (3-1) to (3-9). Further, the following formulas (3-1) and (3-2) correspond to X in the formula (1) ¹ In the case of the formula (2-1), the following formula (3-3) corresponds to X in the formula (1) ¹ In the case of the formula (2-2), the following formulas (3-4), (3-5) and (3-6) correspond to X in the formula (1) ¹ In the case of the above formula (2-3). In addition, the following formulas (3-7) and (3-8) correspond to X in the formula (1) ¹ In the case of the above formula (2-4), the following formula (3-9) corresponds to X in the above formula (1) ¹ In the case of the above-mentioned formulae (2-5).

[ chemical 8]

(in the formulae (3-1) to (3-9), R ⁵¹ ～R ⁷¹ Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 24 carbon atoms. Wherein R is ⁵¹ ～R ⁵⁴ Any one of R ⁵⁵ ～R ⁵⁷ Any one of R ⁶⁰ ～R ⁶² Any one of R ⁶³ R is R ⁶⁴ Any one of R ⁶⁶ ～R ⁶⁸ Any one of, R ⁶⁹ R is R ⁷⁰ Any one of which is a bond. Multiple R's in one molecule ⁵¹ ～R ⁷¹ Each independently having the definition. "×" indicates a bond. )

In the formulas (3-1) to (3-9), R ⁵¹ ～R ⁷¹ The monovalent organic group of (2) is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and still more preferably 1 to 10 carbon atomsAlkyl or phenyl is particularly preferably C1-5 alkyl or phenyl.

Specific examples of the compound [ W ] include compounds represented by the following formulae (b-1) to (b-11), respectively.

[ chemical 9]

(wherein "Ph" is phenyl.)

The content of the compound [ W ] is preferably 0.001 parts by mass or more, more preferably 0.003 parts by mass or more, and still more preferably 0.005 parts by mass or more, based on 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent, in order to sufficiently obtain the effect of improving the liquid crystal alignment property and voltage holding ratio of the obtained liquid crystal element. The content of the compound [ W ] is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, based on 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent, in order to suppress the decrease in electrical characteristics caused by the compound [ W ] remaining in the film after post baking. Further, the compound [ W ] may be used singly or in combination of two or more.

< other additive component >

The liquid crystal aligning agent of the present disclosure may contain other additive components than the compound [ W ] as required. The other additive components are not particularly limited as long as they do not impair the effects of the present disclosure. Specific examples of other additive components include: a compound having a crosslinkable group (hereinafter, also referred to as "crosslinkable group-containing compound"), a functional silane compound, an antioxidant, a metal chelate compound, a hardening accelerator, a surfactant, a filler, a dispersant, a photosensitizer, a solvent, and the like, which are different from the compound [ W ]. The blending ratio of the other additive components may be appropriately selected depending on the respective compounds 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 to further improve adhesion between the liquid crystal alignment film and the substrate and reliability of the liquid crystal element. Examples of the crosslinkable group-containing compound include a compound having at least one crosslinkable group selected from the group consisting of a cyclic carbonate group, an epoxy group, an isocyanate group, a blocked isocyanate group, an oxetanyl group, a trialkoxysilyl group, and a polymerizable unsaturated bond group. Examples of the polymerizable unsaturated bond group include a (meth) acryloyl group, an ethylenic carbon-carbon double bond, a vinylphenyl group, and a vinyloxy group (CH ₂ =ch-O-), vinylidene, maleimide, and the like, a cyclic carbonate group, an epoxy group, or a (meth) acryl group is preferable in terms of high reactivity by light or heat.

Specific examples of the crosslinkable group-containing compound include: 1, 6-hexanediol diglycidyl ether, N, N, N ', N ' -tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N ', N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane, N, N-diglycidyl-aminomethylcyclohexane, 3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane, 1, 6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, compounds represented by the following formulae (11-1) to (11-10), and the like. The crosslinkable group-containing compound may be used singly or in combination of two or more.

[ chemical 10]

When the crosslinkable group-containing compound is blended into the liquid crystal aligning agent, the blending ratio of the crosslinkable group-containing compound is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less relative to 100 parts by mass of the compound [ W ] contained in the liquid crystal aligning agent, in terms of obtaining the effect of the blending of the compound [ W ], that is, the effect of sufficiently performing the crosslinking reaction even when the post-baking temperature is set to a low temperature (for example, 170 ℃ or less) and producing a liquid crystal element having sufficiently high liquid crystal alignment properties and voltage holding ratio. When the compound [ W ] and the compound having a crosslinkable group are used in combination, the blending ratio of the compound having a crosslinkable group is preferably an amount of 10 parts by mass or less, more preferably 0.001 to 5 parts by mass, and still more preferably 0.001 to 1 part by mass, based on 100 parts by mass of the total amount of the compound [ W ] and the compound having a crosslinkable group.

< solvent component >

The liquid crystal aligning agent of the present disclosure is prepared in the form of a polymer composition in the form of a solution, which is prepared by dissolving a polymer component, a compound [ W ], and optionally formulated components, preferably in an organic solvent. Examples of the organic solvents include: aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and the like. The solvent component may be one of these, or may be a mixed solvent of two or more kinds.

As the solvent component of the liquid crystal aligning agent of the present disclosure, there may be mentioned: a solvent having high solubility and leveling property of the polymer (hereinafter, also referred to as a "first solvent"), a solvent having good wetting expansibility (hereinafter, also referred to as a "second solvent"), and a mixed solvent of these solvents.

Specific examples of the solvent include, for example: n-methyl-2-pyrrolidone, γ -butyrolactone, γ -butyrolactam, N-dimethylformamide, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diisobutylketone, ethylene carbonate, propylene carbonate, N-ethyl-2-pyrrolidone, N- (N-pentyl) -2-pyrrolidone, N- (tert-butyl) -2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 3-butoxy-N, N-dimethylpropionamide, 3-methoxy-N, N-dimethylpropionamide, and the like;

examples of the second solvent include: ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether acetate, 3-methoxy-1-butanol, cyclopentanone, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, isopentyl isobutyrate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, diisoamyl ether, and the like. Further, one of these solvents may be used alone, or two or more of them may be used in combination.

The solid content concentration (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) in the liquid crystal aligning agent can be appropriately selected in consideration of viscosity, volatility, and the like, and is preferably in the range of 1 to 10 mass%. When the solid content concentration is less than 1 mass%, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10 mass%, the film thickness of the coating film becomes too large, making it difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, and the coatability tends to decrease.

Liquid crystal alignment film and liquid crystal device

The liquid crystal alignment film of the present disclosure is formed from the liquid crystal alignment agent prepared as described. The liquid crystal element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operation mode of the liquid crystal In the liquid crystal element is not particularly limited, and is applicable to various modes such as a Twisted Nematic (TN) mode, a super Twisted Nematic (Super Twisted Nematic, STN) mode, a vertical alignment (Vertical Alignment, VA) mode (including a vertical alignment-Multi-domain vertical alignment (Vertical Alignment-Multi-domain Vertical Alignment, VA-MVA) mode, a vertical alignment-pattern vertical alignment (Vertical Alignment-Patterned Vertical Alignment, VA-PVA) mode, an In-Plane Switching (IPS) mode, a fringe field Switching (Fringe Field Switching, FFS) mode, an optically compensated bend (Optically Compensated Bend, OCB) mode, and a polymer stable alignment (Polymer Sustained Alignment, PSA) mode. The liquid crystal element can be manufactured by a method including the following steps 1 to 3, for example. In step 1, the substrate is used depending on the desired mode of operation. Step 2 and step 3 are common in each mode of operation.

Step 1: formation of coating film >

First, a liquid crystal aligning agent is coated on a substrate, and the coated surface is preferably heated, thereby forming a coating film on the substrate. As the substrate, for example, a transparent substrate containing the following materials can be used: float glass, sodium glass, and the like; plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). A transparent conductive film provided on one surface of a substrate can be used: comprises tin oxide (SnO) ₂ ) Nesa (Nesa) film (registered trademark of PPG company, U.S.) containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) Indium Tin Oxide (ITO) films, and the like. In the case of manufacturing a TN-type, STN-type, or VA-type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal device, a substrate provided with an electrode patterned into a comb-teeth type and an opposing substrate not provided with an electrode are used. The liquid crystal aligning agent is preferably applied to the substrate on the electrode forming surface by offset printing, flexography, spin coating, roll coater or inkjet printing.

After the liquid crystal alignment agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal alignment agent, and the like. The pre-baking temperature is preferably 30-200 ℃, and the pre-baking time is preferably 0.25-10 minutes. Thereafter, a calcination (post baking) step is performed for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure in the polymer component. The calcination temperature (post-baking temperature) at this time is preferably 80 to 250 ℃, more preferably 80 to 200 ℃. In addition, the liquid crystal aligning agent using the compound [ W ] as a crosslinking agent is preferable in that a liquid crystal element exhibiting good liquid crystal alignment property and voltage holding ratio can be obtained even when post baking is performed at a low temperature of 170 ℃. The post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the film thus formed is preferably 0.001 μm to 1 μm.

Step 2: orientation process >

In the case of manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal device, a process (alignment process) of imparting liquid crystal alignment ability to the coating film formed in step 1 is performed. Thus, the liquid crystal alignment film is obtained by imparting the liquid crystal molecules with alignment ability to the coating film. As the orientation treatment, the following treatment can be used: a rubbing treatment in which a coating film formed on a substrate is rubbed in a predetermined direction by a roller around which a cloth containing, for example, fibers such as nylon (nylon), rayon (rayon), cotton (cotton) or the like is wound, a photo-alignment treatment in which a coating film formed on a substrate is irradiated with light to impart liquid crystal alignment ability to the coating film, or the like. 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 may be directly used as a liquid crystal alignment film, but in order to further improve the liquid crystal alignment ability, the coating film may be subjected to an alignment treatment. 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 photo-alignment may be performed by the following method or the like: a method of irradiating a coating film after the post-baking step, a method of irradiating a coating film after the pre-baking step and before the post-baking step, and a method of irradiating a coating film during heating of a coating film in at least any one of the pre-baking step and the post-baking step. As the radiation to be irradiated to the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150nm to 800nm can be used. Preferably ultraviolet rays containing light having a wavelength of 200nm to 400 nm. In the case where the radiation is polarized, the radiation may be linearly polarized or partially polarized. In the case where the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these directions. The irradiation direction in the case of unpolarized radiation is set to be an oblique direction.

As the light source used, for example, there may be mentionedThe following are listed: low pressure mercury lamps, high pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, and the like. The irradiation amount of the radiation to the substrate surface is preferably 400J/m ² ～50,000J/m ² More preferably 1,000J/m ² ～20,000J/m ² . After the light irradiation for imparting orientation ability, a treatment of cleaning the substrate surface with, for example, water, an organic solvent (for example, methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, or the like) or a mixture of these, or a treatment of heating the substrate may be performed.

Step 3: construction of liquid Crystal cell

As described above, two substrates on which liquid crystal alignment films are formed are prepared, and liquid crystal is arranged between the two substrates arranged to face each other, thereby manufacturing a liquid crystal cell. In manufacturing a liquid crystal cell, for example, the following methods can be mentioned: the method of disposing two substrates facing each other with a gap therebetween so that the liquid crystal alignment films face each other, bonding the peripheral portions of the two substrates with a sealant, and filling a cell gap surrounded by the substrate surface and the sealant with liquid crystal and sealing the filling hole is a method using a liquid crystal Drop Fill (ODF) method. For example, epoxy resin containing a hardener and alumina balls as spacers (spacers) can be used as the sealant. The liquid crystal may be nematic liquid crystal or discotic liquid crystal, and among them, nematic liquid crystal is preferable. In the PSA mode, after the liquid crystal cell is constructed, the liquid crystal cell is irradiated with light in a state where a voltage is applied between conductive films provided on a pair of substrates.

In the case of manufacturing a PSA-type liquid crystal element, a liquid crystal cell is constructed in the same way as described above except that liquid crystal is injected or dropped together with a photopolymerizable compound between a pair of substrates having a conductive film. Then, the liquid crystal cell is irradiated with light in a state where a voltage is applied between the conductive films provided on the pair of substrates. The voltage applied here may be, for example, 5V to 50V dc or ac. The light to be irradiated may be, for example, ultraviolet light or visible light including light having a wavelength of 150nm to 800nm, and preferably light having a wavelength of 300nm to 400nmUltraviolet rays. Examples of the light source for irradiating light include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The irradiation amount of light is preferably 1,000J/m ² ～200,000J/m ² More preferably 1,000J/m ² ～100,000J/m ² 。

Then, a polarizing plate is attached to the outer surface of the liquid crystal cell as needed, thereby producing a liquid crystal element. The polarizing plate may be exemplified by: a polarizing film called an "H film" in which iodine is absorbed while polyvinyl alcohol is stretched and oriented with a cellulose acetate protective film is sandwiched between the obtained polarizing plates or a polarizing plate including the H film itself.

The liquid crystal element of the present disclosure is effectively applicable to various applications, for example, to various display devices such as a timepiece, a portable game machine, a word processor, a notebook personal computer, a car navigation system, a video camera, a personal digital assistant (Personal Digital Assistant, PDA), a digital camera, a mobile phone, a smart phone, various monitors, a liquid crystal television, an information display, and the like, or to a light adjusting film, a phase difference film, and the like. In addition, the liquid crystal element of the present disclosure is also suitable for a liquid crystal element using a dye as a colorant of a color filter layer. Here, as the dye, a known dye that can be used in a liquid crystal element can be used.

Examples

Hereinafter, specific description will be given by way of examples, but the disclosure is not limited to the following examples.

In the examples below, 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 by Gel Permeation Chromatography (GPC) under the following conditions. The molecular weight distribution (Mw/Mn) was calculated from the Mw and Mn obtained.

GPC column: manufactured by Tosoh (thigh) and TSKgelGRCXLII

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

Column temperature: 40 DEG C

Flow rate: 1.0 mL/min

Pressure: 68kgf/cm ²

Solution viscosity of Polymer

The solution viscosity (mPas) of the polymer was measured at 25℃using an E-type rotational viscometer.

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

(tetracarboxylic dianhydride)

[ chemical 11]

(diamine compound)

[ chemical 12]

(Compound [ W ])

[ chemical 13]

(other crosslinking agent)

[ chemical 14]

< Synthesis of Compound [ W ]

Synthesis examples 1 to 8

The compounds (BL-1) to (BL-8) were synthesized by the methods described in the following documents.

Compound (BL-1): internal enol esters (Endo-enol esters); m. field (M.Ueda), M.Obelia (M.Yabuuchi), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 15,323 (1977)

Compound (BL-2): endo-imidoesters (Endo-acyl imidates); m. field (M.Ueda), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 17,1163 (1979)

Compound (BL-3): endo-imidoesters (Endo-acyl imidates); m.field (M.Ueda), K.wood field (K.Kino), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 13,659 (1975)

Compound (BL-4): internal enol esters (Endo-enol esters); m. field (M.Ueda), T.high bridge (T.Takahashi), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 15,2641 (1977)

Compound (BL-5): exo-enol esters (Exo-enol esters); m. field (M.Ueda), T.high bridge (T.Takahashi), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 14591 (1976)

Compound (BL-6): endo-imidoesters (Endo-acyl imidates); m. field (M.Ueda), K.wood field (K.Kino), K.mountain wood (K.Yamaki), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 16,155 (1978)

Compound (BL-7): oxime esters (Oxime esters); m.field (M.Ueda), H.feather dyeing (H.Hazome), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 14,1127 (1976)

Compound (BL-8): exo-imidoester (Exo-acyl imidate); m. field (M.Ueda), S.tube field (S.Kanno), Y.Jinjing (Y.Imai), journal of Polymer science (J.Polym.Sci.), polymer chemistry (Polym.chem.ed.), 14,663 (1976)

< Synthesis of Polymer >

Synthesis example 2-1: synthesis of Polyamic acid

50 parts by mole of 2,3, 5-tricarboxycyclopentylacetic anhydride and 50 parts by mole of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride were dissolved in N-methyl-2-pyrrolidone (NMP) in a 100mL two-necked flask under nitrogen, 10 parts by mole of compound (DA-1) and 90 parts by mole of compound (DA-2) were then added thereto, and the reaction was carried out at 60℃for 4 hours to obtain a solution containing 20% by mass of polymer (P-1). A small amount of the polyamic acid solution thus obtained was separated, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the solution viscosity was found to be 1020 mPas.

Synthesis examples 2-2 to 2-14

The same operations as in Synthesis example 2-1 were conducted except that the types and amounts of the monomers used were changed as shown in Table 1 below, to obtain solutions containing polyamic acids (respectively referred to as polymers (P-2) to (P-14)). In table 1, "-" means that the column compound is not used.

TABLE 1

Synthesis examples 2 to 15

In a 100mL two-necked flask, 100 parts by mol of 2,3, 5-tricarboxycyclopentylacetic dianhydride (compound (AH-2)) was dissolved in N-methyl-2-pyrrolidone (NMP) under nitrogen, and 100 parts by mol of (E) -4- (3- (2, 4-diaminophenethyl) -3-oxoprop-1-en-1-yl) phenyl 4- (4, 4-trifluorobutoxy) benzoate was then added, and the reaction was carried out at 60℃for 24 hours to obtain a solution containing 30% by mass of polymer (P-15). A small amount of the polyamic acid solution thus obtained was separated, and NMP was added to prepare a solution having a polyamic acid concentration of 10% by mass, and the solution viscosity was measured to be 640 mPas.

Synthesis example 3-1: synthesis of polyorganosiloxane

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

[ 15]

A1000 ml three-necked flask was charged with 90.0g of 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 500g of methyl isobutyl ketone and 10.0g of triethylamine, and the mixture was stirred at room temperature. Then, 100g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then mixed under reflux and reacted at 80℃for 6 hours. After the completion of the reaction, the organic layer was taken out, washed with a 0.2 mass% aqueous ammonium nitrate solution until the washed water became neutral, and then distilled under reduced pressure to remove the solvent and water. Methyl isobutyl ketone was added in an appropriate amount to obtain a 50 mass% solution of polyorganosiloxane (E-1) having an epoxy group.

Into a 500ml three-necked flask were charged 26.69g (0.3 mol equivalent) of side chain carboxylic acid (ca-1) shown below, 2.00g of tetrabutylammonium bromide, 80g of a solution containing polyorganosiloxane (E-1) and 239g of methyl isobutyl ketone, and the mixture was stirred at 110℃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, and concentration and NMP dilution were repeated 2 times by a rotary evaporator to obtain a 15 mass% NMP solution of the intermediate of the polymer (ES-1). After 0.45g (0.1 mol equivalent) of trimellitic anhydride was added to 50g of the intermediate solution, the mixture was prepared so that the solid content concentration became 10 mass% by using NMP, and then the mixture was stirred at room temperature for 4 hours, whereby an NMP solution of polymer (ES-1) was obtained.

[ 16]

Synthesis example 3-2

Synthesis example 3-1 was conducted in the same manner as in Synthesis example 3-1 except that the side chain carboxylic acid (ca-2) shown below was used in place of the side chain carboxylic acid (ca-1), whereby an NMP solution containing the polymer (ES-2) was obtained.

[ chemical 17]

Synthesis example 4-1: synthesis of styrene-maleimide-based copolymer

1. Synthesis of Compound (MI-1)

Compound (MI-1) was synthesized according to the following scheme 2.

[ chemical 18]

In a 100mL eggplant-shaped flask equipped with a stirrer were added 11.8g of (E) -3- (4- ((4- (4, 4-trifluorobutoxy) benzoyl) oxy) phenyl) acrylate, 20g of thionyl chloride, 0.01g of N, N-dimethylformamide, and stirred at 80℃for 1 hour. Thereafter, excess thionyl chloride was removed by a diaphragm pump, and 100g of tetrahydrofuran was added thereto to prepare a solution A. 5.67g of 4-hydroxyphenyl maleimide, 200g of tetrahydrofuran and 12.1g of triethylamine were again placed in a 500mL three-necked flask equipped with a stirrer, and the flask was ice-cooled. Solution a was added dropwise thereto and stirred at room temperature for 3 hours. The reaction solution was reprecipitated with 800mL of water, and the obtained white solid was dried in vacuo, whereby 13.3g of compound (MI-1) was obtained.

2. Synthesis of Polymer

5.00g (8.6 mmol) of the obtained compound (MI-1) as a polymerization monomer, 0.64g (4.3 mmol) of 4-vinylbenzoic acid, 2.82g (13.0 mmol) of 4- (2, 5-dioxo-3-pyrrolin-1-yl) benzoic acid, 3.29g (17.2 mmol) of 4- (glycidyloxymethyl) styrene, 0.31g (1.3 mmol) of 2,2' -azobis (2, 4-dimethylpentanenitrile) as a radical polymerization initiator, 0.52g (2.2 mmol) of 2, 4-diphenyl-4-methyl-1-pentene as a chain transfer agent, and 25mL of tetrahydrofuran as a solvent were charged in a 100mL two-necked flask under nitrogen, and polymerization was performed at 70℃for 5 hours. After reprecipitation in n-hexane, the precipitate was filtered, the target polymer (StMI-1) was obtained by vacuum drying at room temperature for 8 hours. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 30000 and the molecular weight distribution Mw/Mn was 2.

Synthesis example 4-2

Synthesis example 4-1 was conducted 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), whereby a polymer (StMI-2) was obtained. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 35000 and the molecular weight distribution Mw/Mn was 2.

[ chemical 19]

Manufacturing and evaluation of friction FFS type liquid crystal display element

Example 1

1. Preparation of liquid Crystal alignment agent (AL-1)

200 parts by mass of the polymer (P-11) obtained in Synthesis example 2-1, 5 parts by mass of the compound (BL-1), and NMP and Butyl Cellosolve (BC) as solvents were added to the solution containing 100 parts by mass of the polymer (P-1) obtained in Synthesis example 2-1 to prepare a solution having a solvent composition of NMP/BC=50/50 (mass ratio) and a solid content concentration of 4.0% by mass. The solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal aligning agent (AL-1).

2. Evaluation of coatability

The liquid crystal aligning agent (AL-1) thus prepared was coated on a glass substrate using a rotator, pre-baked for 1 minute using a hot plate of 80℃and then heated (post-baked) in an oven of 230℃in which the inside of the chamber was replaced with nitrogen for 30 minutes, thereby forming a coating film having an average film thickness of 0.1. Mu.m. The film was observed with a microscope having a magnification of 100 times and 10 times, and the presence or absence of film thickness unevenness and pinholes was examined. For the evaluation, "good (a)" was set when both film thickness unevenness and pinholes were not observed even when observation was performed with a 100-fold microscope, "good (B)" was set when at least either film thickness unevenness and pinholes were observed with a 100-fold microscope but both film thickness unevenness and pinholes were not observed with a 10-fold microscope, and "poor (C)" was set when at least either film thickness unevenness and pinholes were clearly observed with a 10-fold microscope. In the above examples, even with a microscope at 100 times, neither film thickness unevenness nor pinholes were observed, and the coatability was evaluated as "good (a)".

3. Evaluation of film hardness

The prepared liquid crystal aligning agent (AL-1) was coated on a glass substrate using a rotator, and pre-baked using a hot plate at 80 ℃ for 1 minute. Thereafter, in an oven with nitrogen substitution in the chamber, A coating film having a thickness of 0.1 μm was formed by heating at 150℃for 1 hour. For the obtained coating film, pencil hardness (surface hardness) was evaluated according to japanese industrial standard (Japanese Industrial Standards, JIS) -K5400. The pencil hardness of the liquid crystal alignment film was evaluated as "a" when the pencil hardness was 4H or more, as "B" when the pencil hardness was 2H or 3H, as "C" when the pencil hardness was H, as "D" when the pencil hardness was less than H, and as a result, the pencil hardness of the liquid crystal alignment film was evaluated as "a".

4. Manufacture of friction horizontal type liquid crystal display element (1)

The prepared liquid crystal aligning agent (AL-1) was coated on the transparent electrode surface of the glass substrate with the transparent electrode containing an ITO film using a rotator, and pre-baked using a hot plate at 80 ℃ for 1 minute. Thereafter, the resultant film was heated at 230℃for 1 hour in an oven in which nitrogen gas was substituted for the inside of the chamber, to thereby form a coating film having a film thickness of 0.1. Mu.m. The coating film was subjected to a rubbing treatment at a roll rotation speed of 400rpm, a stage moving speed of 3 cm/sec and a Mao Yaru length of 0.1mm by using a rubbing machine having a roll around which a rayon cloth was wound. Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a clean oven at 100 ℃ for 10 minutes, thereby obtaining a substrate having a liquid crystal alignment film. The series of operations is repeated to produce a pair (two sheets) of substrates having liquid crystal alignment films.

An epoxy adhesive agent containing alumina balls having a diameter of 3.5 μm was applied by screen printing to the outer periphery of the surface of one of the substrates having a liquid crystal alignment film, and then the adhesive agent was laminated so that the respective liquid crystal alignment film surfaces faced each other and pressure-bonded, thereby curing the adhesive agent. Then, a nematic liquid crystal (MLC-6221 manufactured by Merck) was filled between a pair of substrates through a liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive, and polarizing plates were bonded to both surfaces of the outer side of the substrates, thereby manufacturing a friction-horizontal liquid crystal display element a.

5. Manufacture of friction horizontal type liquid crystal display element (2)

The same procedure as in 4 was carried out except that the post-baking temperature was changed from 230℃to 150℃to thereby produce a friction-horizontal liquid crystal display element B.

6. Evaluation of liquid Crystal alignment

For each of the above-manufactured friction horizontal type liquid crystal display element a and friction horizontal type liquid crystal display element B, the presence or absence of an abnormal domain (domain) in a change in brightness when a voltage of 5V is turned ON/OFF (ON/OFF) was observed by an optical microscope, the case where there was no abnormal domain was "a", the case where there was a part of abnormal domain was "B", and the case where there was an abnormal domain as a whole was "C", and the liquid crystal orientation was evaluated. As a result, in the above examples, the liquid crystal alignment was "a" for either element a having a post-baking temperature of 230 ℃ or element B having a post-baking temperature of 150 ℃.

7. Evaluation of Voltage holding Rate (voltage holding ratio, VHR)

For each of the above-produced friction horizontal type liquid crystal display element a and friction horizontal type liquid crystal display element B, a voltage of 5V was applied at a time of 60 microseconds and a span of 167 milliseconds, and then a voltage holding ratio after 167 milliseconds from the release of the application was measured. The assay device was VHR-1 manufactured using the east yang technology (TOYO technology) (Stroke). At this time, the voltage holding ratio is "S" when it is 98% or more, is "a" when it is 95% or more and less than 98%, is "B" when it is 80% or more and less than 95%, is "C" when it is 50% or more and less than 80%, and is "D" when it is less than 50%. As a result, in the above examples, the voltage holding ratio was evaluated as "a" for both the element a having the post-baking temperature of 230 ℃ and the element B having the post-baking temperature of 150 ℃.

Example 5, example 8 and example 9

Liquid crystal aligning agents were obtained by preparing the same solid content concentrations as in example 1, except that the blending compositions were changed as shown in table 2 below. Further, the liquid crystal aligning agent was used to evaluate the coating property and film hardness of the liquid crystal aligning agent in the same manner as in example 1, and a friction horizontal type liquid crystal display element a and a friction horizontal type liquid crystal display element B were produced in the same manner as in example 1, and various evaluations were performed. These results are shown in table 3 below.

Manufacturing and evaluation of FFS type liquid crystal display element

Example 2

1. Preparation of liquid Crystal alignment agent (AL-2)

Liquid crystal aligning agent (AL-2) was prepared in the same solvent composition and solid content concentration as in example 1, except that the types and amounts of the polymer and the crosslinking agent used were changed as described in table 2 below.

2. Evaluation of coatability

The coatability of the liquid crystal aligning agent was evaluated in the same manner as in example 1 above except that (AL-2) was used instead of (AL-1). As a result, "A" in the examples.

3. Evaluation of film hardness

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

4. Manufacturing of light FFS type liquid Crystal display element (1)

The prepared liquid crystal alignment agent (AL-2) was applied to each of the surfaces of a glass substrate having a flat electrode, an insulating layer and comb-teeth-shaped electrodes laminated in this order on one surface and a facing glass substrate having no electrode, using a rotator, and heated (prebaked) by a hot plate at 80 ℃ for 1 minute. Thereafter, the film was dried (post-baking) in an oven at 230℃with nitrogen substitution in the chamber for 30 minutes to form a coating film having an average film thickness of 0.1. Mu.m. Irradiating the surface of the coating film with a light containing a linear polarized 254nm bright line from the normal direction of the substrate using an Hg-Xe lamp Ultraviolet ray 1,000J/m ² And a photo-alignment treatment is performed to form a liquid crystal alignment film on the substrate.

Then, a liquid crystal injection port was left at the edge of the surface on which the liquid crystal alignment film was formed, a pair of substrates having the liquid crystal alignment film was laminated with an epoxy adhesive agent containing alumina balls having a diameter of 5.5 μm applied by screen printing, and the substrates were pressure-bonded so that the projection directions of the polarization axes at the time of light irradiation became antiparallel to each other, and the adhesive agent was thermally cured at 150 ℃ for 1 hour. Then, after filling a nematic liquid crystal (MLC-7028 manufactured by Merck (Merck)) from a liquid crystal injection port between a pair of substrates, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow alignment at the time of liquid crystal injection, the liquid crystal cell was manufactured by heating the liquid crystal at 120 ℃ and then gradually cooling the liquid crystal cell to room temperature. Then, the polarizing plates were bonded to both outer surfaces of the substrate so that the polarizing directions of the polarizing plates were orthogonal to each other and an angle of 90 ° was formed with respect to the projection direction of the ultraviolet ray of the liquid crystal alignment film on the substrate surface, thereby manufacturing the optical FFS type liquid crystal display device a.

5. Manufacturing of light FFS type liquid Crystal display element (2)

The same procedure as in the above-mentioned 4 was carried out except that the post-baking temperature was changed from 230℃to 150℃to thereby produce a liquid crystal display element B of the FFS type.

6. Evaluation of liquid Crystal alignment

The liquid crystal alignment properties of the manufactured FFS type liquid crystal display element a and FFS type liquid crystal display element B were evaluated in the same manner as in example 1. As a result, in the above-described embodiment, the liquid crystal alignment properties of both the optical FFS type liquid crystal display element a and the optical FFS type liquid crystal display element B are "a".

7. Evaluation of Voltage Holding Rate (VHR)

The voltage holding ratio of the manufactured FFS type liquid crystal display element a and FFS type liquid crystal display element B was evaluated in the same manner as in example 1. As a result, in the above examples, the voltage holding ratios of the optical FFS type liquid crystal display element a and the optical FFS type liquid crystal display element B were evaluated as "a".

Examples 10 to 12

Liquid crystal aligning agents were obtained by preparing the same solid content concentrations as in example 1, except that the blending compositions were changed as shown in table 2 below. Further, the application property and film hardness of the liquid crystal alignment agent were evaluated using each liquid crystal alignment agent in the same manner as in example 1, and the optical FFS type liquid crystal display element a and the optical FFS type liquid crystal display element B were produced in the same manner as in example 2, and various evaluations were performed. These results are shown in table 3 below.

Manufacturing and evaluation of VA type liquid crystal display element

Example 3

1. Preparation of liquid Crystal alignment agent (AL-3)

Liquid crystal aligning agent (AL-3) was prepared in the same solvent composition and solid content concentration as in example 1, except that the types and amounts of the polymer and the crosslinking agent used were changed as described in table 2 below.

2. Evaluation of coatability

The coatability of the liquid crystal aligning agent was evaluated in the same manner as in example 1 above except that (AL-3) was used instead of (AL-1). As a result, "A" in the examples.

3. Evaluation of film hardness

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

Manufacturing of VA mode liquid Crystal display element (1)

The prepared liquid crystal aligning agent (AL-3) was coated on the transparent electrode surface of the glass substrate with the transparent electrode containing the ITO film using a rotator, and pre-baking was performed using a hot plate at 80℃for 1 minute. Thereafter, the resultant film was heated at 230℃for 1 hour in an oven in which nitrogen gas was substituted for the inside of the chamber, to thereby form a coating film having a film thickness of 0.1. Mu.m. The operation is repeated, whereby a pair (two sheets) of substrates having liquid crystal alignment films are produced.

An epoxy adhesive agent containing alumina balls having a diameter of 3.5 μm was applied by screen printing to the outer periphery of the surface of one of the substrates having a liquid crystal alignment film, and then the adhesive agent was laminated so that the respective liquid crystal alignment film surfaces faced each other and pressure-bonded, thereby curing the adhesive agent. Then, a negative type liquid crystal (MLC-6608 manufactured by Merck) was filled between a pair of substrates through a liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive, and polarizing plates were bonded to both surfaces of the outside of the substrates, thereby manufacturing a VA type liquid crystal display device a.

Manufacturing of VA mode liquid Crystal display element (2)

The same procedure as in 4 was carried out except that the post-baking temperature was changed from 230℃to 150℃to thereby produce a VA-type liquid crystal display element B.

6. Evaluation of liquid Crystal alignment

The liquid crystal alignment properties of the manufactured VA-mode liquid crystal display device A, VA-mode liquid crystal display device B were evaluated in the same manner as in example 1. As a result, in the above examples, the liquid crystal alignment properties of the VA-mode liquid crystal display element A, VA-mode liquid crystal display element B were all "a".

7. Evaluation of Voltage Holding Rate (VHR)

The VA-mode liquid crystal display device A, VA-mode liquid crystal display device B thus manufactured was evaluated for voltage holding ratio in the same manner as in example 1. As a result, in the examples, the voltage holding ratios of the VA-mode liquid crystal display element A, VA-mode liquid crystal display element B were all evaluated as "a".

Example 4

A liquid crystal aligning agent was prepared at the same solid content concentration as in example 1, except that the blending composition was changed as shown in table 2 below. Further, using the obtained liquid crystal aligning agent, the coatability and film hardness of the liquid crystal aligning agent were evaluated in the same manner as in example 1, and a VA-type liquid crystal display element A, VA-type liquid crystal display element B was produced in the same manner as in example 3, and various evaluations were performed. The results are shown in table 3 below.

Manufacturing and evaluation of PSA-type liquid Crystal display element

Example 6

1. Preparation of liquid Crystal alignment agent (AL-6)

Liquid crystal aligning agent (AL-6) was prepared in the same solvent composition and solid content concentration as in example 1, except that the types and amounts of the polymer and the crosslinking agent used were changed as described in table 2 below.

2. Evaluation of coatability

The coatability of the liquid crystal aligning agent was evaluated in the same manner as in example 1 above except that (AL-6) was used instead of (AL-1). As a result, "A" in the examples.

3. Evaluation of film hardness

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

4. Preparation of liquid Crystal composition

To 10g of nematic liquid crystal (MLC-6608 manufactured by Merck (Merck)) were added 5 mass% of a liquid crystalline compound represented by the following formula (L1-1) and 0.3 mass% of a photopolymerizable compound represented by the following formula (L2-1) and mixed to obtain a liquid crystal composition LC1.

[ chemical 20]

Manufacturing of PSA-type liquid Crystal display element (1)

The prepared liquid crystal alignment agent (AL-6) was applied to each electrode surface of two glass substrates each having a conductive film including an ITO electrode using a liquid crystal alignment film printer (manufactured by japan photo printing), heated (pre-baked) on a hot plate at 80 ℃ for 2 minutes to remove the solvent, and then heated (post-baked) on a hot plate at 230 ℃ for 10 minutes to form a coating film having an average film thickness of 0.06 μm. For these coating films, after ultrasonic cleaning in ultrapure water for 1 minute, drying was performed in a clean oven at 100 ℃ for 10 minutes, thereby obtaining a pair (two sheets) of substrates having liquid crystal alignment films. The pattern of the electrode used is the same type of pattern as the electrode pattern in the PSA mode.

Then, an epoxy adhesive agent containing alumina balls having a diameter of 5.5 μm was applied to the outer edge of the surface of one of the pair of substrates having the liquid crystal alignment film, and then the adhesive agent was cured by being superimposed and pressure-bonded so that the liquid crystal alignment film surfaces face each other. Then, the prepared liquid crystal composition LC1 was filled between a pair of substrates from a liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive, thereby manufacturing a liquid crystal cell. Thereafter, an alternating current of 10V at a frequency of 60Hz was applied between the conductive films of the liquid crystal cell, and in a liquid crystal-driven state, an ultraviolet irradiation device using a metal halide lamp as a light source was used at 100,000J/m ² Is irradiated with ultraviolet rays. The irradiation amount is a value measured using a light meter measuring with a wavelength of 365nm as a reference. Thereafter, the PSA type liquid crystal display element a was manufactured by bonding the polarizing plates to the outer surfaces of the substrates so that the polarizing directions of the polarizing plates were perpendicular to each other and an angle of 45 ° was formed between the polarizing directions of the ultraviolet rays of the liquid crystal alignment films and the projection directions of the ultraviolet rays on the substrate surfaces.

Manufacturing of PSA-type liquid Crystal display element (2)

The same procedure as in the above-mentioned item 5 was carried out except that the post-baking temperature was changed from 230℃to 150℃to thereby produce a PSA-type liquid crystal display element B.

7. Evaluation of liquid Crystal alignment

The PSA-type liquid crystal display element A, PSA-type liquid crystal display element B thus produced was evaluated for liquid crystal alignment in the same manner as in example 1. As a result, in the above examples, the liquid crystal alignment properties of the PSA-type liquid crystal display element A, PSA-type liquid crystal display element B were all "a".

8. Evaluation of Voltage Holding Rate (VHR)

The PSA-type liquid crystal display element A, PSA-type liquid crystal display element B thus manufactured was evaluated for voltage holding ratio in the same manner as in example 1. As a result, in the examples, the voltage holding ratios of the PSA-type liquid crystal display element A, PSA-type liquid crystal display element B were all evaluated as "a".

Example 7, example 13 and example 14

Liquid crystal aligning agents were obtained by preparing the same solid content concentrations as in example 1, except that the blending compositions were changed as shown in table 2 below. The liquid crystal aligning agent obtained was used to evaluate the coatability and film hardness of the liquid crystal aligning agent in the same manner as in example 1, and a PSA-type liquid crystal display element A, PSA-type liquid crystal display element B was produced in the same manner as in example 6, and various evaluations were performed in the same manner as in example 1. The evaluation results are shown in table 3 below.

Manufacturing and evaluation of light vertical type liquid crystal display element

Example 15

1. Preparation of liquid Crystal alignment agent (AL-15)

Liquid crystal aligning agent (AL-15) was prepared in the same solvent composition and solid content concentration as in example 1, except that the types and amounts of the polymer and the crosslinking agent used were changed as described in table 2 below.

2. Evaluation of coatability

The coatability of the liquid crystal aligning agent was evaluated in the same manner as in example 1 above except that (AL-15) was used instead of (AL-1). As a result, "A" in the examples.

3. Evaluation of film hardness

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

4. Manufacture of light vertical type liquid crystal display element (1)

The prepared liquid crystal aligning agent (AL-15) was coated on the transparent electrode surface of the glass substrate with the transparent electrode containing an ITO film using a rotator, and pre-baked using a hot plate at 80 ℃ for 1 minute. Thereafter, the resultant film was heated at 230℃for 1 hour in an oven in which nitrogen gas was substituted for the inside of the chamber, to thereby form a coating film having a film thickness of 0.1. Mu.m. Then, using an Hg-Xe lamp and a Glan-Taylor prism, polarized ultraviolet rays 1,000J/m including an open line of 313nm were irradiated to the coated film surface from a direction inclined by 40 DEG from the substrate normal ² And imparts liquid crystal alignment capability. Repeating the same processIn the same manner, a pair (two sheets) of substrates having a liquid crystal alignment film were produced.

After applying an epoxy adhesive agent containing alumina spheres having a diameter of 3.5 μm to the outer periphery of the surface of one of the substrates having a liquid crystal alignment film by screen printing, the surfaces of the liquid crystal alignment films of the pair of substrates were opposed to each other, and the substrates were pressure-bonded so that the optical axes of ultraviolet rays of the substrates became antiparallel to each other in the projection direction of the substrate surface, and the adhesive agent was heat-cured at 150 ℃ for 1 hour. Then, a gap between the substrates was filled with a negative type liquid crystal (MLC-6608 manufactured by Merck) from a liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow alignment at the time of liquid crystal injection, the liquid crystal was heated at 130℃and then cooled to room temperature gradually. Then, the polarizing plates were bonded to both outer surfaces of the substrate so that the polarizing directions of the polarizing plates were orthogonal to each other and an angle of 45 ° was formed with respect to the projection direction of the ultraviolet ray of the liquid crystal alignment film on the substrate surface, thereby manufacturing the optically perpendicular liquid crystal display element a.

5. Manufacture of light vertical type liquid crystal display element (2)

The same procedure as in 4 was carried out except that the post-baking temperature was changed from 230℃to 150℃to thereby produce a light-vertical liquid crystal display element B.

6. Evaluation of liquid Crystal alignment

The liquid crystal alignment properties of the manufactured optically perpendicular liquid crystal display element a and optically perpendicular liquid crystal display element B were evaluated in the same manner as in example 1. As a result, in the above-described embodiment, the liquid crystal alignment properties of the optically perpendicular liquid crystal display element a and the optically perpendicular liquid crystal display element B are both "a".

7. Evaluation of Voltage Holding Rate (VHR)

The voltage holding ratio of the manufactured optically perpendicular liquid crystal display element was evaluated in the same manner as in example 1. As a result, in the above examples, the voltage holding ratios of the optical vertical type liquid crystal display element a and the optical vertical type liquid crystal display element B were evaluated as "a".

Examples 16 to 25 and comparative examples 1 to 6

Liquid crystal aligning agents were obtained by preparing the same solid content concentrations as in example 1, except that the blending compositions were changed as shown in table 2 below. Further, the coatability and film hardness of the liquid crystal alignment agent were evaluated using each liquid crystal alignment agent in the same manner as in example 1, and a light-vertical liquid crystal display element a and a light-vertical liquid crystal display element B were produced in the same manner as in example 15, and various evaluations were performed. These results are shown in table 3 below. In Table 2, "-" means that the column compound is not used.

TABLE 2

TABLE 3

As shown in table 3, in examples 1 to 25 using the liquid crystal aligning agent containing the compound [ W ] as the crosslinking agent, the coatability was evaluated as "a" except for example 14, and example 14 was evaluated as "B". In addition, in examples 1 to 25, the obtained liquid crystal display elements were also good in liquid crystal alignment and voltage holding ratio, and were evaluated as "S", "a" or "B". In particular, in example 17 using a diamine rich polymer (P-12), the voltage holding ratio was evaluated as "S" at a post-baking temperature of 150℃and was particularly excellent. On the other hand, in example 22 using the acid anhydride-enriched polymer (P-13), the voltage holding ratio was evaluated as "B" when the post-baking temperature was 150 ℃.

In contrast, in comparative example 1 containing no crosslinking agent and comparative examples 2 to 6 containing only a crosslinking agent different from the compound [ W ], the evaluation of the liquid crystal alignment and the voltage holding ratio of "a" or "B" was inferior to that of example when the post-baking temperature was 230 ℃.

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

Claims

1. A liquid crystal aligning agent comprising: a polymer component; and a heterocyclic compound having 2 or more partial structures represented by the following formulae (3-1) to (3-9) in one molecule;

in the formulae (3-1) to (3-9), R ⁵¹ ～R ⁷¹ A monovalent organic group having 1 to 24 carbon atoms and each independently a hydrogen atom, a halogen atom or a group; wherein R is ⁵¹ ～R ⁵⁴ Any one of R ⁵⁵ ～R ⁵⁷ Any one of R ⁶⁰ ～R ⁶² Any one of R ⁶³ R is R ⁶⁴ Any one of R ⁶⁶ ～R ⁶⁸ Any one of, R ⁶⁹ R is R ⁷⁰ Any one of which is a bond; multiple R's in one molecule ⁵¹ ～R ⁷¹ Each independently has the R ⁵¹ ～R ⁷¹ Is defined as follows; ". Times" denote binding bonds;

wherein the liquid crystal aligning agent does not contain polyamide which is the reaction product of the heterocyclic compound and the diamine compound.

2. The liquid crystal aligning agent according to claim 1, wherein the polymer component comprises a polymer having a partial structure represented by the following formulae (7-1) to (7-3), respectively;

In the formula (7-1), A ²¹ Is a single bond or a divalent organic group having 1 or more carbon atoms, Y ¹ R is a protecting group ²¹ ～R ²³ Each independently represents a hydrogen atom or a monovalent organic group having 1 or more carbon atoms; m is an integer of 0 to 6; in the formula (7-2), Y ² Is a protecting group; in the formula (7-3), R ²⁴ R is R ²⁵ Each independently is a divalent hydrocarbon group, Y ³ Is a protecting group; "×" indicates a bond.

3. The liquid crystal aligning agent according to claim 1, wherein the polymer component comprises a polymer having a primary amino group at a terminal.

4. The liquid crystal aligning agent according to claim 1, wherein the polymer component comprises at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

5. A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 4.

6. A liquid crystal cell comprising the liquid crystal alignment film according to claim 5.

7. A method of manufacturing a liquid crystal element, comprising:

a step of applying the liquid crystal aligning agent according to any one of claims 1 to 4 to each substrate surface of a pair of substrates, and irradiating the substrate surface thus applied with light, thereby imparting liquid crystal aligning ability and forming a liquid crystal alignment film; and

And a step of constructing a liquid crystal cell by disposing a pair of substrates on which the liquid crystal alignment film is formed, via a liquid crystal layer, so that the coated surfaces of the substrates face each other.

8. A method of manufacturing a liquid crystal element, comprising:

a step of applying the liquid crystal aligning agent according to any one of claims 1 to 4 to the respective conductive films of a pair of substrates having conductive films;

a step of constructing a liquid crystal cell by disposing a pair of substrates coated with the liquid crystal aligning agent through a liquid crystal layer so that the coated surfaces of the substrates face each other; and

and a step of irradiating the liquid crystal cell with light in a state where a voltage is applied between the conductive films.