CN111556981A

CN111556981A - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal element, and method for producing liquid crystal element

Info

Publication number: CN111556981A
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: 2020-08-18
Anticipated expiration: 2039-02-19
Also published as: CN111556981B; WO2019193855A1; JP6981542B2; JPWO2019193855A1; TWI815876B; KR102404080B1; TW201943844A; KR20200098659A

Abstract

The liquid crystal aligning agent contains a polymer component and a heterocyclic ring-containing compound having 2 or more (n is removed from the structure represented by the formula (1) (1)) in one moleculen is an integer of 1 or more) hydrogen atom. In the formula (1), X¹is-CR¹＝CR²-and the like. A. the¹A divalent organic group may also be bonded to other ring structures to form a fused ring together with the other ring structures. A plurality of A in one molecule¹And X¹Each independently having the definition.

Description

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

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on japanese application No. 2018-73138 filed on No. 4/5 in 2018, and the contents of the description thereof are incorporated herein.

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 certain direction. In general, the liquid crystal alignment film is formed on the substrate by applying, preferably heating, a liquid crystal alignment agent obtained by dissolving a polymer component in an organic solvent to the surface of the substrate. In addition, a rubbing treatment or a photo-alignment treatment is performed on the organic film formed on the substrate using the liquid crystal aligning agent as necessary, thereby imparting liquid crystal aligning ability.

In recent years, a large-screen and high-definition liquid crystal television is a main body, and small-sized display terminals such as smart phones and tablet personal computers (tablet PCs) have been widely used, and demands for high-quality liquid crystal elements have been further increased than ever. Under such circumstances, various liquid crystal aligning agents have been proposed to improve the performance of liquid crystal alignment films and to improve various characteristics of liquid crystal devices (for example, liquid crystal alignment properties, voltage holding ratios, and image sticking characteristics) (for example, see 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 ' -diglycidylaminomethyl) 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 can be obtained, which can suppress display defects due to rubbing damage. Patent document 2 discloses that a polyamic acid or polyimide and a compound containing an imide bond and 2 or more epoxy groups (for example, monoallyl diglycidyl isocyanuric acid, triglycidyl isocyanuric acid, and the like) are contained in a liquid crystal aligning agent. Patent document 3 discloses a liquid crystal aligning agent containing a polyamic acid or polyimide and a polyfunctional epoxy compound having 2 or more 3, 4-epoxycyclohexane rings. When a liquid crystal alignment film is formed using a liquid crystal alignment agent containing a crosslinking agent, the film is generally cured by crosslinking by heating (post-baking) during film formation.

Documents of the prior art

Patent document

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

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

Patent document 3: japanese patent laid-open No. 2016-170409

Disclosure of Invention

Problems to be solved by the invention

In order to sufficiently cure the film by adding the crosslinking agent and to improve the film hardness, it is desirable to heat at the time of film formation at a high temperature (for example, 200 ℃ or higher). However, when a high-temperature heating is required for forming the liquid crystal alignment film, there are cases where defects such as restrictions are imposed on the material of the substrate, and the application of the film substrate as the substrate of the liquid crystal element is limited. In addition, in a color liquid crystal display element, a dye used as a colorant for a color filter is relatively weak against heat, and there is a fear that the use of the dye is limited when heating at the time of film formation at a high temperature is required. On the other hand, if the film is not sufficiently cured, the film hardness is insufficient, and there is a concern that the liquid crystal alignment property or the voltage holding ratio may be lowered.

In addition, when the solubility of the polymer component is lowered by the addition of the crosslinking agent or the crosslinking agent is precipitated in the alignment agent, the coating property of the liquid crystal alignment agent to the substrate is deteriorated. In addition, the liquid crystal alignment and voltage holding ratio of the obtained liquid crystal device may be lowered, or the product yield may be lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal aligning agent which comprises: the liquid crystal device has good coating property on a substrate, has high film hardness even when film formation is carried out at low temperature, and has excellent liquid crystal orientation and voltage retention rate.

Means for solving the problems

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

[1] A liquid crystal aligning agent comprising: a polymeric component; and a heterocyclic ring-containing compound having a partial structure in which at least 2 hydrogen atoms (n is an integer of 1 or more) are removed from the structure represented by the following formula (1) in one molecule.

[ solution 1]

(in the formula (1), X¹Is any one of the groups represented by the following formulae (2-1) to (2-5). A. the¹A divalent organic group may also be bonded to other ring structures to form a fused ring together with the other ring structures. A plurality of A in one molecule¹And X¹Each independently having the definition. )

[ solution 2]

In (formulae (2-1) to (2-5), R¹～R⁷Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 or more carbon atoms. The "+" in the formulae (2-3) and (2-5) represents a bond with the oxygen atom in the formula (1)。)

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

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

[4] A method of manufacturing a liquid crystal element, comprising: applying the liquid crystal aligning agent of [1] to each substrate surface of a pair of substrates, and irradiating the coated substrate surface with light to impart liquid crystal aligning ability and form a liquid crystal alignment film; and a step of configuring a liquid crystal cell by disposing the pair of substrates on which the liquid crystal alignment films are formed, in opposition to each other with the application surfaces of the substrates facing each other through a liquid crystal layer.

[5] A method of manufacturing a liquid crystal element, comprising: applying the liquid crystal aligning agent of [1] to the conductive film of each of a pair of substrates having the conductive film; a step of configuring a liquid crystal cell by disposing a pair of substrates coated with the liquid crystal aligning agent in opposition to each other with their coating surfaces facing each other through a liquid crystal layer; 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 disclosed by the invention, a liquid crystal element with excellent liquid crystal aligning performance and voltage holding ratio can be obtained even if heating is carried out at low temperature (for example, the temperature is below 170 ℃). In addition, the liquid crystal aligning agent disclosed by the invention has excellent coating performance on a substrate, so that the reduction of the product yield can be inhibited.

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 ring-containing compound having a partial structure in which at least 2 hydrogen atoms (n is an integer of at least 1) 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 necessary will be described.

In the present specification, the term "hydrocarbon group" is intended to include chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group having no cyclic structure in the main chain and consisting of only a chain structure. The polymer may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. The alicyclic hydrocarbon group is not necessarily composed of only the structure of the alicyclic hydrocarbon, and includes a hydrocarbon group having a chain structure in a part thereof. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. In addition, the structure may not necessarily be composed of only an aromatic ring structure, and may include a chain structure or an alicyclic hydrocarbon structure in a part thereof.

< Polymer ingredient >

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 polyamic acids, polyamic acid esters, polyimides, polyamines, polyalkylenamines, polyorganosiloxanes, polyesters, polyamides, polyamideimides, polystyrenes, polybenzoxazole precursors, polybenzoxazoles, cellulose derivatives, polyacetals, polymaleimides, styrene-maleimide-based copolymers, or polymers having a poly (meth) acrylate as a main skeleton and having a functional group that reacts with (crosslinks) the compound [ W ]. The term (meth) acrylate refers to both acrylates and methacrylates. The polyalkyleneamine is a polymer having a carbon-carbon double bond in the ortho position to the amino group of the polyamine, and examples thereof include: polyalkenaminoketones, polyalkenaminoesters, polyalkenaminonitriles, polyalkenamesulfonyl, and the like.

Of these, at least one selected from the group consisting of polyamic acids, polyamic acid esters, polyimides, polyamines, polyvinylamines, polyamides, polystyrenes, poly (meth) acrylates, polymaleimides, styrene-maleimide copolymers, and polyorganosiloxanes is preferable in terms of sufficiently improving the performance (for example, liquid crystal alignment properties, electrical characteristics, mechanical strength, weather resistance, and the like) of the obtained liquid crystal device. In terms of the higher effect of the improvement by the compound [ W ], the polymer preferably contains a structural unit derived from a diamine, and more preferably contains at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamine, polyvinylamine, and polyamide.

The polymer component is preferably a polymer containing a primary amino group at the end. In such a case, it is preferable to further promote the crosslinking by the compound [ W ] and to further improve the voltage holding ratio of the liquid crystal device to be obtained. 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, polyvinylamine, and polyamide, and in terms of further improving the effect of improving the liquid crystal orientation and the voltage holding ratio by the compound [ W ], and ease of synthesis, the polymer component is particularly preferably at least one partially selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

(Polyamic acid)

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

Tetracarboxylic acid dianhydride

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

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-tricarboxycyclopentylacetic dianhydride, 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-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, cyclopentanetetracarboxylic dianhydride, Cyclohexane tetracarboxylic dianhydride, and the like; examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4' - (hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol ditrimellic anhydride, 4' - (hexafluoroisopropylidene) diphthalic anhydride, and 4,4' -carbonyldiphthalic anhydride, and in addition, tetracarboxylic dianhydrides described in japanese unexamined patent publication No. 2010-97188 can be used. Further, tetracarboxylic dianhydrides 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, known diamine compounds can be used, and examples thereof include: aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. In terms of high reactivity with the compound [ W ] when heated and further promotion of crosslinking, and improvement of solubility of the polymer in a solvent, a diamine compound having a partial structure represented by each of the following formulae (7-1) to (7-3) (hereinafter, also referred to as "protecting group-containing diamine") can be preferably used.

[ solution 3]

(in the formula (7-1), A²¹Is a single bond or a divalent organic group having 1 or more carbon atoms, Y¹Is a protecting group, R²¹～R²³Each 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), Y²Is a protecting group. In the formula (7-3), R²⁴And R²⁵Each independently is a divalent hydrocarbon group, Y³Is a protecting group. "" indicates a bond. )

In the formulae (7-1) to (7-3), Y¹～Y³The protecting group (b) is preferably a group which 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 these, preferred is a urethane-based protecting groupSpecific 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 preferable in terms of high releasability by heat and further reducing the remaining amount of deprotected portions in the film.

R²¹And R²²The monovalent organic group(s) 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.

R²³The monovalent organic group (C) is preferably a C1-10 monovalent alkyl group or a protecting group. The protecting group is preferably a carbamate-based protecting group, and particularly preferably a tert-butoxycarbonyl group.

R²⁴And R²⁵The divalent hydrocarbon group(s) 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 A²¹Examples of the divalent organic group of (3) include: divalent hydrocarbon groups, groups having-O-, -CO-, -COO-, -NH-between carbon-carbon bonds of the hydrocarbon groups, and the like. A. the²¹Preferably to an aromatic ring, particularly preferably to a benzene ring.

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

[ solution 4]

(wherein TMS represents trimethylsilyl.)

When the diamine containing a protecting group is used, the use ratio thereof is preferably 2 mol% or more, more preferably 3 mol% to 80 mol%, and further preferably 5 mol% to 70 mol% with respect to the total amount of the diamine compounds used for synthesizing the polymer. The protective group-containing diamine may be used alone or in combination of two or more.

Examples of the diamine used for synthesizing the polyamic acid include, in addition to the above, aliphatic diamines: m-xylylenediamine, 1, 3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc.; examples of the alicyclic diamine 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, cholestenyloxy-3, 5-diaminobenzene, cholestanoxy-2, 4-diaminobenzene, cholestenyloxy-2, 4-diaminobenzene, cholestanoalkyl 3, 5-diaminobenzoate, cholestanyl 3, 5-diaminobenzoate, lanostanyl 3, 5-diaminobenzoate, 3, 6-bis (4-acylanoxy) cholestane, 3, 6-bis (4-aminophenoxy) cholestane, 2, 4-diamino-N, N-diallylaniline, 4- (4' -trifluoromethoxybenzoyloxy) cyclohexyl-3, 5-diaminobenzoate, 1-bis (4- ((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 3, 5-diaminobenzoic acid ═ 5 ξ -cholestan-3-yl, the following formula (E-1)

[ solution 5]

(in the formula (E-1), X^IAnd X^IIEach independently is a single bond, -O-, -COO-or-OCO- (wherein "" represents the same as X)^IBinding bond of) R^IIs C1-3 alkanediyl, R^IIIs a single bond or C1-3 alkanediyl, a is 0 or 1, b is an integer of 0-2, c is an integer of 1-20, and d is 0 or 1. Wherein a and b do not become 0 at the same time. )

Side chain type diamines such as a compound represented by the formula (I), a diamine having a cinnamic acid structure in a side chain, and compounds represented by the following formulae (d-8-1) to (d-8-7):

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, N' -diaminotoluene, N '-bis (4-aminophenoxy) hexane, N' -bis (4-aminophenyl) -, Bis (4-aminophenyl) amine, bis (4-aminophenyl) methylamine, 2, 6-diaminopyridine, 1, 4-bis- (4-aminophenyl) -piperazine, N ' -bis (4-aminophenyl) -benzidine, 2' -dimethyl-4, 4' -diaminobiphenyl, 2' -bis (trifluoromethyl) -4,4' -diaminobiphenyl, 4' -diaminodiphenyl ether, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 2-bis (4-aminophenyl) hexafluoropropane, 4' - (phenylenediisopropylidene) dianiline, 1, 4-bis (4-aminophenoxy) benzene, 4' -bis (4-aminophenoxy) biphenyl, N ' -bis (4-aminophenyl) -piperazine, N ' -bis (4-aminophenyl) -benzidine, 2' -bis (4-aminophenyl) -4,4' -diaminobiphenyl, 4' -bis (4-aminophenoxy), Main chain type diamines such as 4,4' - [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); examples of the diaminoorganosiloxane include 1, 3-bis (3-aminopropyl) -tetramethyldisiloxane, and diamines described in Japanese patent application laid-open No. 2010-97188 may be used.

[ solution 6]

[ solution 7]

Synthesis of Polyamic acid

The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride and the diamine compound as described above, optionally together with a molecular weight modifier. The ratio of the tetracarboxylic dianhydride to the diamine compound to be used in the synthesis reaction of the polyamic acid is preferably 0.2 to 2 equivalents based on 1 equivalent of the amino group of the diamine compound and the acid anhydride group of the tetracarboxylic dianhydride. Examples of the molecular weight regulator include: acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The ratio of the molecular weight modifier 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 polyamic acid as a polymer having a primary amino group at an end, there can be mentioned: (1) a method of increasing the amount of the diamine compound used (for example, 1.1 to 1.5 molar equivalents based on the amount of the tetracarboxylic dianhydride used) as compared with the amount of the tetracarboxylic dianhydride in the reaction between the tetracarboxylic dianhydride and the diamine compound; (2) and a method of reacting the monoamine compound as a molecular weight modifier.

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 hour 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 those using one or more solvents selected from the group consisting of N-methyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol, and halogenated phenol, or mixtures of one or more of these solvents with other organic solvents (e.g., butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount (a) of the organic solvent used is preferably such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50 mass% relative to the total amount (a + b) of the reaction solution.

As described above, a reaction solution obtained by dissolving the polyamide acid is obtained. The reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after the polyamic acid contained in the reaction solution is separated.

(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 for 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 an amic acid structure and an amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester may be used as it is for the production of the liquid crystal aligning agent, or the polyamic acid ester contained in the reaction solution may be separated and then used for the production of the liquid crystal aligning agent.

(polyimide)

The polyimide can be obtained, for example, by subjecting a polyamic acid synthesized as described above to dehydrative ring closure and imidization. The polyimide may be a complete imide product obtained by dehydration ring closure of the whole amic acid structure of the polyamic acid as a precursor thereof, or may be a partial imide product obtained by dehydration ring closure of only a part of the amic acid structure and coexistence of 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 ratio represents a percentage of the number of imide ring structures relative to the total of the number of amic acid structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring may be an imide ring.

The dehydration ring-closing of the polyamic acid is preferably performed by the following method: dissolving polyamide acid in organic solvent, adding dehydrating agent and dehydration ring-closing catalyst into the solution, and heating if necessary. In the above method, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride or the like can be used. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol based on 1mol of the amic acid structure of the polyamic acid. As the dehydration ring-closure catalyst, for example, a tertiary amine such as pyridine, collidine, lutidine or triethylamine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include organic solvents exemplified by those 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 used as it is 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. Polyimides can also be obtained by imidization of polyamic acid esters.

When the liquid crystal aligning ability is imparted to the organic film formed using the liquid crystal aligning agent by the photo-alignment method, it is preferable that at least a part of the polymer component is a polymer having photo-alignment groups. The photo-alignment group is a functional group capable of imparting anisotropy to a film by a photo-reaction such as a photo-isomerization reaction, a photo-dimerization reaction, a photo-fries rearrangement (photo-frierarangement) reaction, or a photo-decomposition reaction by light irradiation.

Specific examples of the photo-alignment 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 group, and a phenyl benzoate-containing group, and is preferably a cinnamic acid structure-containing group or a cyclobutane-containing group in terms of high sensitivity to light and ease of introduction into the polymer.

The polymer having photo-alignment groups 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 thereof, and reacting the epoxy group-containing polymer with a carboxylic acid having a photo-alignment group. The content ratio of the photo-alignment groups in the polymer is appropriately set according to the kind of the photo-alignment groups so as to provide a desired liquid crystal alignment ability to the coating film, and for example, in the case of a group containing a cinnamic acid structure, the content ratio of the photo-alignment groups is preferably 5 mol% or more, more preferably 10 mol% to 60 mol% with respect to the total constituent units of the polymer having the photo-alignment groups. When the photo-alignment group has a cyclobutane-containing structure, the content of the photo-alignment group is preferably 50 mol% or more, more preferably 80 mol% or more, based on the total constituent units of the polymer having the photo-alignment group. The polymer having photo-alignment groups may be used alone or in combination of two or more.

The polymer component contained in the liquid crystal aligning agent may be a single type or a blend (blend) type of two or more types. 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 a high polarity is preferably present in a lower layer, and the first polymer is preferably present in an upper layer, so that phase separation can occur. Preferred examples 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 selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and the other is in the form of polyorganosiloxane.

(III) a form in which one of the first polymer and the second polymer is at least one polymer selected from the group consisting of polyamic acids, polyamic acid esters, and polyimides, and the other 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 by, for example, hydrolyzing and condensing a hydrolyzable silane compound. Examples of the hydrolyzable silane compound include: alkoxysilane compounds such as tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane; nitrogen/sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane and N- (3-cyclohexylamino) propyltrimethoxysilane; epoxy group-containing silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane and 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane; unsaturated bond-containing alkoxysilane compounds such as 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropylmethyldiethoxysilane, vinyltriethoxysilane, and p-styryltrimethoxysilane; trimethoxysilylpropyl succinic anhydride, and the like. The hydrolyzable silane compound may be used alone or in combination of two or more of these. Further, "(meth) acryloyloxy" means to include "acryloyloxy" and "methacryloyloxy".

The hydrolysis/condensation reaction is carried out by reacting one or more silane compounds as described above with water, preferably in the presence of an appropriate catalyst and an organic solvent. When the reaction is carried out, the proportion of water used is preferably 1 to 30 moles based on 1 mole of the silane compound (total amount). Examples of the catalyst to be used include: acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds, and the like. The amount of the catalyst to be used varies depending on the kind of the catalyst, reaction conditions such as temperature, and the like, and is suitably set, for example, preferably from 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, alcohols, and the like, and among these, it is preferable to use an organic solvent which is not water-soluble or hardly water-soluble. The amount of the organic solvent to be used is preferably 10 to 10,000 parts by mass based on 100 parts by mass of the total of the silane compounds used in the reaction.

The hydrolysis/condensation reaction is preferably carried out by heating with 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 is completed, the organic solvent layer separated from the reaction solution is dried with a drying agent as necessary, and then the solvent is removed, whereby the target polyorganosiloxane can be obtained. The method of synthesizing the polyorganosiloxane is not limited to the hydrolysis/condensation reaction, and may be carried out, for example, by a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and an alcohol.

When the polyorganosiloxane is a polymer having photo-alignment groups, the method for synthesizing the polyorganosiloxane is not particularly limited, and the following methods may be mentioned: a polyorganosiloxane having an epoxy group in a side chain (hereinafter, also referred to as "epoxy group-containing polyorganosiloxane") is synthesized using an epoxy group-containing silane compound as at least a part of a raw material, and then the epoxy group-containing polyorganosiloxane is reacted with a carboxylic acid having a photo-alignment group. The method is simple and preferable in that the introduction rate of the photosensitive group and the liquid crystalline structure can be increased. Further, a polyorganosiloxane having a photo-alignment group in a side chain can be synthesized by a reaction in which a hydrolyzable silane compound having a photo-alignment group is contained in a monomer. The polyorganosiloxane preferably has a weight average molecular weight (Mw) in terms of polystyrene, as measured by Gel Permeation Chromatography (GPC), 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 synthesizing the polymer (Q) include compounds having a (meth) acryloyl group, a vinyl group, a styryl group, a maleimide group, and the like. Specific examples of such compounds include: unsaturated carboxylic acids such as (meth) acrylic acid, α -ethylacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid: unsaturated carboxylic acid esters such as cycloalkyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trimethoxysilylpropyl (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; and the like. In the case where the polymer (Q) is a polymer having photo-alignment groups, a compound having photo-alignment groups may be used as the monomer having a synthesized unsaturated bond. The monomer having a polymerizable unsaturated bond may be used alone or in combination of two or more.

The polymer (Q) can be obtained by, for example, polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. The polymerization initiator to be 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 proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass with respect to 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, etc., preferably diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, etc. 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 used is preferably 0.1 to 60% by mass of the total amount (b) of the monomers used in the reaction relative to the total amount (a + b) of the reaction solution. The polymer (Q) preferably has a weight average molecular weight (Mw) of 250 to 500,000, more preferably 500 to 100,000, in terms of polystyrene as measured by GPC.

In the above-described embodiments (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 even more preferably 50 to 90 mass% based on 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 improving the liquid crystal alignment property and the voltage holding ratio of the liquid crystal device. In the case where an organic film formed using a liquid crystal aligning agent is provided with liquid crystal aligning ability by a photo-alignment method, an alignment film having more excellent liquid crystal alignment properties can be obtained by using a polyorganosiloxane, a poly (meth) acrylate, or a styrene-maleimide copolymer as a polymer having a photo-alignment group, which is preferable in view of the above.

< Compound [ W ] >

Next, the compound [ W ] will be described. The compound [ W ] is a cycloalkenylalcohol ester, a cycloalkanoylamide ester, a exocyclic acylamide ester or an oxime ester, and has, as a crosslinkable group, a plurality of groups each having, in one molecule, a partial structure (hereinafter, also referred to as "partial structure a") obtained by removing n (n is preferably 2) arbitrary hydrogen atoms from the structure represented by the formula (1).

In the formula (1), A is¹The divalent organic group of (2) includes: 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. the¹Preferably carbon numberThe hydrocarbon group is 2 to 20, 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 formulae (2-1) to (2-5)¹～R⁷Examples of the monovalent organic group include: monovalent hydrocarbon groups having 1 to 10 carbon atoms, groups having-O-between carbon-carbon bonds in the hydrocarbon groups, and the like. R¹～R⁷The monovalent organic group(s) is preferably a monovalent hydrocarbon group, more preferably a hydrocarbon group having 1 to 12 carbon atoms, further preferably an alkyl group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and particularly preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group.

Compound [ W]The compound is preferably a compound in which a plurality of the partial structures A are bonded directly or through a linking group. The linking group is preferably a hydrocarbon group having 1 to 30 carbon atoms, or a group having-O-, -S-, -NH-, -CO-in the carbon-carbon bond of the hydrocarbon group. X is a high degree of freedom in setting the compound and is a reactive group of the polymer component¹Preferred are groups represented by the formulae (2-3) to (2-5).

Preferable specific examples of the partial structure A include partial structures represented by the following formulae (3-1) to (3-9). Further, the following formulas (3-1) and (3-2) correspond to X in the formula (1)¹In the case of said formula (2-1), the following formula (3-3) corresponds to X in said formula (1)¹In the case of the formula (2-2), the following formulae (3-4), (3-5) and (3-6) correspond to X in the formula (1)¹In the case of said formula (2-3). Further, the following formulae (3-7) and (3-8) correspond to X in the formula (1)¹In the case of the formula (2-4), the following formula (3-9) corresponds to the case of the formula (2-5).

[ solution 8]

(formula (3-1) to (3-9) wherein R⁵¹～R⁷¹Each independently a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 24 carbon atoms. Wherein R is⁵¹～R⁵⁴Any one of (1), R⁵⁵～R⁵⁷Any one of (1), R⁶⁰～R⁶²Any one of (1), R⁶³And R⁶⁴Any one of (1), R⁶⁶～R⁶⁸Any one of (1) and R⁶⁹And R⁷⁰Any of which is a bond. Multiple R in one molecule⁵¹～R⁷¹Each independently having the definition. "" indicates a bond. )

In the formulae (3-1) to (3-9), R⁵¹～R⁷¹The monovalent organic group(s) is (are) 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, further preferably an alkyl group or a phenyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group or a phenyl group having 1 to 5 carbon atoms.

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

[ solution 9]

(wherein "Ph" is a phenyl group.)

From the viewpoint of sufficiently obtaining the effect of improving the liquid crystal alignment property and the voltage holding ratio of the obtained liquid crystal device, the content ratio of the compound [ W ] is preferably 0.001 parts by mass or more, more preferably 0.003 parts by mass or more, and further preferably 0.005 parts by mass or more, relative to 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent. In addition, the content ratio 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, with respect to 100 parts by mass of the total amount of the polymer components contained in the liquid crystal aligning agent, from the viewpoint of suppressing the deterioration of the 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 Components >

The liquid crystal aligning agent of the present disclosure may also contain other additive components other than the compound [ W ], if necessary. The other additive components are not particularly limited as long as the effects of the present disclosure are not impaired. Specific examples of the other additive components include: a compound having a crosslinkable group (hereinafter, also referred to as "crosslinkable group-containing compound") other than the compound [ W ], a functional silane compound, an antioxidant, a metal chelate compound, a curing accelerator, a surfactant, a filler, a dispersant, a photosensitizer, a solvent, and the like. The blending ratio of the other additive components may be appropriately selected depending on each compound within a range not impairing the effect of the present disclosure.

(Compound having crosslinkable group)

The compound containing a crosslinkable group can also be used for further improving the adhesion between the liquid crystal alignment film and the substrate and the reliability of the liquid crystal element. Examples of the crosslinkable group-containing compound include compounds 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 bonding group. Examples of the polymerizable unsaturated bonding group include a (meth) acryloyl group, an ethylenic carbon-carbon double bond, a vinylphenyl group, and a vinyloxy (CH)₂CH — O-), vinylene, maleimide, and the like, and cyclic carbonate groups, epoxy groups, or (meth) acryloyl groups are preferable in terms of high reactivity to 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-diglycidylaminomethyl) cyclohexane, N, N, N ', N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane, N, N-diglycidylaminomethylcyclohexane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 1, 6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and the like, which are represented by the following formulae (11-1) to (11-10). The crosslinkable group-containing compound may be used singly or in combination of two or more.

[ solution 10]

In the case where the crosslinkable group-containing compound is blended in the liquid crystal aligning agent, from the viewpoint of obtaining the effect of blending the compound [ W ], that is, the effect of making the crosslinking reaction sufficiently proceed even when the post-baking temperature is low (for example, 170 ℃ or lower) to produce a liquid crystal device having sufficiently high liquid crystal alignment properties and voltage holding ratio, 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 still more preferably 100 parts by mass or less with respect to 100 parts by mass of the compound [ W ] contained in the liquid crystal aligning agent. When the compound [ W ] and the crosslinkable group-containing compound are used in combination, the blending ratio of the crosslinkable group-containing compound is preferably such that the total amount of the compound [ W ] and the crosslinkable group-containing compound is 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, relative to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.

< solvent component >

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

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

Specific examples of the solvent include: n-methyl-2-pyrrolidone, γ -butyrolactone, γ -butyrolactam, N-dimethylformamide, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone, 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, isoamyl isobutyrate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, diisoamyl ether, and the like. One of these solvents may be used alone, or two or more of them may be used in combination.

The concentration of the solid component in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) may 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% by 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 is too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent tends to increase to lower the coatability.

Liquid crystal alignment film and liquid crystal cell

The liquid crystal alignment film of the present disclosure is formed of the liquid crystal aligning 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 the liquid crystal can be applied to various modes such as a Twisted Nematic (TN) mode, a Super Twisted Nematic (STN) mode, a Vertical Alignment (VA) mode (including a Vertical Alignment-Multi-domain Vertical Alignment (VA-MVA) mode, a Vertical Alignment-Patterned Vertical Alignment (VA-PVA) mode, etc.), an In-Plane Switching (IPS) mode, a Fringe Field Switching (FFS) mode, an Optically Compensated Bend (Optically Compensated Bend, OCB) mode, a Polymer Stabilized Alignment (PSA) mode, and the like. The liquid crystal element can be manufactured by a method including, for example, the following steps 1 to 3. In step 1, the substrate used is different depending on the desired operation mode. The step 2 and the step 3 are commonly used in each operation mode.

< step 1: formation of coating film

First, a liquid crystal aligning agent is applied to a substrate, and preferably, the coated surface is heated, thereby forming a coating film on the substrate. As the substrate, for example, a transparent substrate including the following materials can be used: float glass, soda glass, and the like; plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin). The transparent conductive film provided on one surface of the substrate may use: containing tin oxide (SnO)₂) A film of (Nesa) (registered trademark of PPG Corp., USA) containing indium oxide-tin oxide (In)₂O₃-SnO₂) Indium Tin Oxide (ITO) film, and the like. In the case of manufacturing a TN-type, STN-type, or VA-type liquid crystal cell, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes patterned into a comb-tooth shape and an opposing substrate provided with no electrodes are used. The application of the liquid crystal aligning agent to the substrate is preferably performed by an offset printing method, a flexographic printing method, a spin coating method, a roll coater method or an inkjet printing method on the electrode-formed surface.

After the liquid crystal aligning agent is applied, it is preferable to perform preliminary heating (pre-baking) for the purpose of preventing dripping of the applied liquid crystal aligning 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 firing (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) in this case is preferably 80 to 250 ℃, more preferably 80 to 200 ℃. Further, a liquid crystal aligning agent using the compound [ W ] as a crosslinking agent is preferable in that a liquid crystal device exhibiting good liquid crystal alignment properties and voltage holding ratio can be obtained even when post-baking is performed at a relatively 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 to 1 μm.

< step 2: orientation treatment

In the case of producing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal cell, a treatment (alignment treatment) is performed to impart liquid crystal alignment ability to the coating film formed in the above-described step 1. Thereby, the coating film is provided with the alignment ability of the liquid crystal molecules, and becomes a liquid crystal alignment film. As the orientation treatment, the following treatments can be used: rubbing treatment in which a coating film formed on a substrate is rubbed in a certain direction by a roller around which a cloth containing fibers such as nylon (nylon), rayon (rayon), or cotton (cotton) is wound, or 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. On the other hand, in the case of manufacturing a Vertical Alignment (VA) type liquid crystal cell, the coating film formed in the above step 1 may be directly used as a liquid crystal alignment film, but an alignment treatment may be applied to the coating film in order to further improve the liquid crystal alignment ability. The liquid crystal alignment film suitable for the vertical alignment type liquid crystal cell can also be suitably used for the PSA type liquid crystal cell.

Light irradiation for photo-alignment can 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 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, the ultraviolet light contains light having a wavelength of 200nm to 400 nm. When the radiation is polarized light, the radiation may be linearly polarized light or partially polarized light. When 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 an oblique direction.

Examples of the light source used include: 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 dose of the radiation to the substrate surface is preferably 400J/m²～50,000J/m²More preferably 1,000J/m²～20,000J/m². After the light irradiation for imparting alignment ability, the substrate surface may be cleaned 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 thereof, or the substrate may be heated.

< step 3: construction of liquid Crystal cell

Two substrates on which liquid crystal alignment films are formed as described above are prepared, and liquid crystal is disposed between the two substrates disposed opposite to each other, thereby manufacturing a liquid crystal cell. In the case of manufacturing a liquid crystal cell, for example, the following methods can be cited: a method of arranging two substrates so that liquid crystal alignment films face each other with a gap therebetween, bonding peripheral portions of the two substrates with a sealant, filling a cell gap surrounded by the substrate surfaces and the sealant with a liquid crystal, and sealing the filling hole, a method of an ODF (OneDrop Fill) method, and the like. For the sealant, for example, an epoxy resin containing a hardener and alumina balls as spacers (spacers) can be used. The liquid crystal includes nematic liquid crystal and smectic 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 subjected to light irradiation treatment 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 cell, a liquid crystal cell is constructed in the same manner as described above, except that liquid crystal is injected or dropped together with a photopolymerizable compound between a pair of substrates having conductive films. Then, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage applied here may be, for example, a direct current or an alternating current of 5V to 50V. The light to be irradiated may be, for example, ultraviolet light or visible light including light having a wavelength of 150nm to 800nm, preferably ultraviolet light including light having a wavelength of 300nm to 400 nm. 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 dose of light irradiation is preferably 1,000J/m²～200,000J/m²More preferably 1,000J/m²～100,000J/m²。

Then, a polarizing plate is bonded to the outer surface of the liquid crystal cell as necessary to produce a liquid crystal cell. Examples of the polarizing plate include: a polarizing plate obtained by sandwiching a polarizing film called an "H film" obtained by stretching and orienting polyvinyl alcohol and absorbing iodine while absorbing it, or a polarizing plate including the H film itself, with a cellulose acetate protective film.

The liquid crystal element of the present disclosure can be effectively applied to various applications, for example, various display devices such as a clock, a portable game, a word processor, a notebook Personal computer, a car navigation system, a camcorder, a Personal Digital Assistant (PDA), a digital camera, a mobile phone, a smartphone, various monitors, a liquid crystal television, an information display, a light adjusting film, a retardation 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

The present disclosure is not limited to the following examples.

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

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

Mw and Mn were measured by Gel Permeation Chromatography (GPC) under the following conditions. The molecular weight distribution (Mw/Mn) was calculated from the Mw and Mn thus obtained.

GPC column: TSKgelGRCXLII manufactured by Tosoh corporation

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

Temperature of the pipe column: 40 deg.C

Flow rate: 1.0 mL/min

Pressure: 68kgf/cm²

< solution viscosity of Polymer >

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

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

(tetracarboxylic dianhydride)

[ solution 11]

(diamine Compound)

[ solution 12]

(Compound [ W ])

[ solution 13]

(other crosslinking Agents)

[ solution 14]

< Synthesis of Compound [ W ]

Synthesis examples 1-1 to 1-8

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

Compound (BL-1): endo-enol esters (Endo-enol ester); m. Shanghai (M.Ueda), M. Obelia (M.Yabuuchi), Y. jin well (Y.Imai), J.Polymer science (J.Polymer.Sci.), Polymer.chem.Ed., 15,323(1977)

Compound (BL-2): endo-imide esters (Endo-acyl imides); m. shanghai (m.ueda), y. jin well (y.imai), journal of polymer science (j.polym.sci.), polym.chem.ed, 17,1163(1979)

Compound (BL-3): endo-imide esters (Endo-acyl imides); m. shanghai (m.ueda), k. wood field (k.kino), y. jin well (y.imai), journal of polymer science (j.ym.sci.), polymer chemistry (ym.chem.ed.), 13,659(1975)

Compound (BL-4): endo-enol esters (Endo-enol ester); m. shanghai (m.ueda), t. highbridge (t.takahashi), y. jin well (y.imai), journal of polymer science (j.polym.sci.), polym.chem.ed, 15,2641(1977)

Compound (BL-5): exo-enol esters (Exo-enol ester); m. shanghai (m.ueda), t. highbridge (t.takahashi), y. jin well (y.imai), journal of polymer science (j.polym.sci.), polym.chem.ed, 14591(1976)

Compound (BL-6): endo-imide esters (Endo-acyl imides); m. shanghai (m.ueda), k. wood field (k.kino), k. mountain wood (k.yamaki), y. jin well (y.imai), journal of polymer science (j.polymer.sci.), ym.chem.ed., 16,155(1978)

Compound (BL-7): oxime esters (Oxime esters); m. shanghai (m.ueda), h.feather dyeing (h.hazome), y. jin well (y.imai), journal of polymer science (j.polym.sci.), polymer chemistry (polym.chem.ed.),14,1127(1976)

Compound (BL-8): exo-imide esters (Exo-acyl midate); m. field (m.ueda), s. dian field (s.kanno), y. current well (y.imai), journal of polymer science (j.polym.sci.), Polvm.

< Synthesis of Polymer >

Synthetic example 2-1: synthesis of Polyamic acid

In a 100mL two-necked flask under nitrogen, 50 parts by mole of 2,3, 5-tricarboxycyclopentylacetic dianhydride and 50 parts by mole of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride were dissolved in N-methyl-2-pyrrolidone (NMP), 10 parts by mole of compound (DA-1) and 90 parts by mole of compound (DA-2) were added thereto, and a 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 obtained polyamic acid solution was collected, NMP was added thereto to prepare a solution having a polyamic acid concentration of 10% by mass, and the measured solution viscosity was 1020 mPas.

Synthesis examples 2-2 to 2-14

A solution containing polyamic acid (polymer (P-2) to polymer (P-14) was obtained in the same manner as in Synthesis example 2-1, except that the type and amount of the monomer used were changed as shown in Table 1. Furthermore, "-" in Table 1 means that the compounds in the column are not used.

[ Table 1]

Synthesis examples 2 to 15

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

[ Synthesis examples 3-1: synthesis of polyorganosiloxane

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

[ solution 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 mixed at room temperature. Then, 100g of deionized water was added dropwise over 30 minutes from the addition funnel, mixed under reflux and reacted at 80 ℃ for 6 hours. After the reaction was completed, the organic layer was taken out, washed with a 0.2 mass% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure. Methyl isobutyl ketone was added in an appropriate amount to obtain a 50 mass% solution of polyorganosiloxane (E-1) having an epoxy group.

A500 ml three-necked flask was charged with 26.69g (0.3mol equivalent) of a side chain carboxylic acid (ca-1) shown below, 2.00g of tetrabutylammonium bromide, 80g of a polyorganosiloxane (E-1) -containing solution, and 239g of methyl isobutyl ketone, and 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 dilution with NMP were repeated 2 times by a rotary evaporator to obtain a 15 mass% NMP solution of the polymer (ES-1) intermediate. To 50g of the intermediate solution, 0.45g (0.1mol equivalent) of trimellitic anhydride was added, and then the resulting mixture was prepared using NMP so that the solid content concentration became 10 mass%, and then stirred at room temperature for 4 hours, thereby obtaining an NMP solution of the polymer (ES-1).

[ solution 16]

[ Synthesis examples 3 and 2]

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

[ solution 17]

Synthesis examples 4-1: synthesis of styrene-maleimide copolymer

1. Synthesis of Compound (MI-1)

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

[ solution 18]

In a 100mL eggplant-shaped flask equipped with a stirrer were charged 11.8g of (E) -3- (4- ((4- (4,4, 4-trifluorobutoxy) benzoyl) oxy) phenyl) acrylate, 20g of thionyl chloride, and 0.01g of N, N-dimethylformamide, and the mixture was stirred at 80 ℃ for 1 hour. Thereafter, excess thionyl chloride was removed by a diaphragm pump, and 100g of tetrahydrofuran was added to prepare a solution a. A500 mL three-necked flask equipped with a stirrer was charged with 5.67g of 4-hydroxyphenylmaleimide, 200g of tetrahydrofuran, and 12.1g of triethylamine again, and subjected to ice-bath. 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 under vacuum, whereby 13.3g of compound (MI-1) was obtained.

2. Synthesis of Polymer

5.00g (8.6mmol) of the obtained compound (MI-1) as a polymerization monomer, 0.64g (4.3mmol) of 4-vinylbenzoic acid, 2.82g (13.0mmol) of 4- (2, 5-dioxo-3-pyrrolin-1-yl) benzoic acid, and 3.29g (17.2mmol) of 4- (glycidyloxymethyl) styrene, 0.31g (1.3mmol) of 2,2' -azobis (2, 4-dimethylvaleronitrile) as a radical polymerization initiator, 0.52g (2.2mmol) 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 carried out at 70 ℃ for 5 hours. The precipitate was filtered and dried under vacuum at room temperature for 8 hours after reprecipitation in n-hexane, whereby the objective polymer (StMI-1) was obtained. The weight-average molecular weight Mw, as measured in terms of polystyrene by GPC, was 30000 and the molecular weight distribution Mw/Mn was 2.

Synthesis examples 4 and 2

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

[ solution 19]

Production and evaluation of < Friction FFS type liquid Crystal display element

[ example 1]

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

To a solution containing 100 parts by mass of the polymer (P-1) obtained in synthesis example 2-1, 200 parts by mass of the polymer (P-11) obtained in synthesis example 2-1, 5 parts by mass of the compound (BL-1), and NMP and Butyl Cellosolve (BC) as solvents were added, and a solution having a solvent composition of NMP/BC 50/50 (mass ratio) and a solid content concentration of 4.0 mass% was prepared. 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 prepared liquid crystal aligning agent (AL-1) was applied to a glass substrate using a spinner, prebaked with a hot plate at 80 ℃ for 1 minute, and then heated in an oven at 230 ℃ with a nitrogen gas substitution in the chamber for 30 minutes (post-baking), thereby forming a coating film having an average film thickness of 0.1. mu.m. The coating film was observed with a microscope at a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. For the evaluation, "good (a)" is set in the case where both the film thickness unevenness and the pinholes are not observed even when observed with a microscope of 100 times, "ok (B)" is set in the case where at least either the film thickness unevenness or the pinholes is observed with a microscope of 100 times but both the film thickness unevenness and the pinholes are not observed with a microscope of 10 times, and "bad (C)" is set in the case where at least either the film thickness unevenness or the pinholes is clearly observed with a microscope of 10 times. In the above examples, both film thickness unevenness and pinholes were not observed even with a microscope of 100 times, 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 spinner and pre-baked for 1 minute using a hot plate at 80 ℃. Thereafter, the resultant was heated at 150 ℃ for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen gas, thereby forming a coating film having a thickness of 0.1 μm. With respect to the obtained coating film, pencil hardness (surface hardness) was evaluated in accordance with Japanese Industrial Standards (JIS) -K5400. The liquid crystal alignment film was evaluated for pencil hardness of 4H or more as "a", pencil hardness of 2H or 3H as "B", pencil hardness of H as "C", and pencil hardness of less than H as "D".

4. Production 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 including the ITO film using a spinner, and pre-baked for 1 minute using a hot plate at 80 ℃. Thereafter, the resultant was heated at 230 ℃ for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen gas, thereby forming a coating film having a thickness of 0.1 μm. The coating film was rubbed by a rubbing machine having a roll around which rayon cloth was wound at a roll rotation speed of 400rpm, a table moving speed of 3 cm/sec and a capillary penetration length of 0.1 mm. 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 above series of operations was repeated to produce a pair of (two pieces of) substrates having liquid crystal alignment films.

An epoxy adhesive containing alumina balls having a diameter of 3.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of one of the substrates by screen printing, and then the surfaces of the liquid crystal alignment films were superimposed and pressure-bonded so as to face each other, thereby curing the adhesive. Then, a nematic liquid crystal (MLC-6221 manufactured by Merck) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive, and polarizing plates were bonded to both surfaces on the outer side of the substrates, thereby producing a liquid crystal display element a of a rubbing horizontal type.

5. Production of a liquid crystal display element of a rubbing horizontal type (2)

The same operation as in 4 above was performed except that the post-baking temperature was changed from 230 ℃ to 150 ℃, thereby manufacturing a liquid crystal display element B of a rubbing horizontal type.

6. Evaluation of liquid Crystal alignment Properties

The liquid crystal alignment properties of each of the produced liquid crystal display elements a and B were evaluated by observing, with an optical microscope, the presence or absence of an abnormal domain (domain) in a light-dark change when a voltage of 5V was turned ON/OFF (ON/OFF) (applied/released), setting the absence of an abnormal domain as "a", the presence of a portion of an abnormal domain as "B", and the presence of an abnormal domain as "C" as a whole. As a result, in the above example, the liquid crystal alignment properties were "a" for both the element a in which the post-baking temperature was set to 230 ℃ and the element B in which the post-baking temperature was set to 150 ℃.

7. Evaluation of Voltage Holding Ratio (VHR)

After applying a voltage of 5V to each of the produced liquid crystal display element a and liquid crystal display element B of the rubbing horizontal type for an application time of 60 microseconds and a span of 167 milliseconds, a voltage holding ratio after 167 milliseconds from the release of the application was measured. The measurement apparatus was VHR-1 manufactured by TOYO Technical (TOYO). In this case, "S" is used when the voltage holding ratio is 98% or more, "a" is used when 95% or more and less than 98%, "B" is used when 80% or more and less than 95%, "C" is used when 50% or more and less than 80%, and "D" is used when less than 50%. As a result, in the above examples, the voltage holding ratio was evaluated as "a" for both of the device a whose post-baking temperature was set to 230 ℃ and the device B whose post-baking temperature was set to 150 ℃.

Example 5, example 8 and example 9

Liquid crystal aligning agents were obtained by preparing the liquid crystal alignment agent at the same solid content concentration as in example 1, except that the formulation composition was changed as shown in table 2 below. Further, using each liquid crystal aligning agent, the coatability of the liquid crystal aligning agent and the film hardness were evaluated in the same manner as in example 1, and a liquid crystal display element a of a rubbing horizontal type and a liquid crystal display element B of a rubbing horizontal type were manufactured in the same manner as in example 1, and various evaluations were performed. These results are shown in table 3 below.

Production and evaluation of < optical FFS-type liquid Crystal display element >

[ example 2]

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

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

2. Evaluation of coatability

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

3. Evaluation of film hardness

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

4. Production of optical FFS type liquid Crystal display device (1)

The prepared liquid crystal aligning agent (AL-2) was applied to the surfaces of a glass substrate having a plate electrode, an insulating layer, and a comb-teeth electrode laminated in this order on one surface and an opposing glass substrate having no electrode on each surface using a spinner, and heated (prebaked) with a hot plate at 80 ℃ for 1 minute. Thereafter, the mixture was dried in an oven at 230 ℃ in which the chamber was purged with nitrogen for 30 minutesThen, the film was dried (post-baked) to form a coating film having an average film thickness of 0.1. mu.m. Irradiating the surface of the coating film with ultraviolet ray of 1,000J/m containing linearly polarized 254nm bright line from the substrate normal direction by using Hg-Xe lamp²And a liquid crystal alignment film is formed on the substrate by performing photo-alignment treatment.

Then, a pair of substrates having liquid crystal alignment films were subjected to screen printing coating of an epoxy resin adhesive containing alumina balls having a diameter of 5.5 μm, with a liquid crystal injection port remaining at the edge of the surface on which the liquid crystal alignment films were formed, and then the substrates were stacked and pressure bonded so that the projection direction of the polarization axis to the substrate surface upon light irradiation became antiparallel, and the adhesive was thermally cured at 150 ℃ for 1 hour. Then, after nematic liquid crystal (MLC-7028 manufactured by Merck) corporation) was filled between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed by an epoxy-based 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 to room temperature. Then, polarizing plates were bonded to both outer surfaces of the substrate so that the polarization directions of the polarizing plates were orthogonal to each other and that an angle of 90 ° was formed between the optical axis of the ultraviolet ray of the liquid crystal alignment film and the projection direction of the substrate surface, thereby producing an optical FFS type liquid crystal display element a.

5. Production of optical FFS type liquid Crystal display device (2)

The same operation as in 4 above was performed except that the post-baking temperature was changed from 230 ℃ to 150 ℃, thereby manufacturing an optical FFS type liquid crystal display element B.

6. Evaluation of liquid Crystal alignment Properties

The liquid crystal alignment properties of the manufactured optical FFS type liquid crystal display element a and optical FFS type liquid crystal display element 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 optical FFS type liquid crystal display element a and the optical FFS type liquid crystal display element B are both "a".

7. Evaluation of Voltage Holding Ratio (VHR)

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

[ examples 10 to 12]

Liquid crystal aligning agents were obtained by preparing the liquid crystal alignment agent at the same solid content concentration as in example 1, except that the formulation composition was changed as shown in table 2 below. Further, using each 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 an optical FFS type liquid crystal display element a and an 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.

Production and evaluation of < VA type liquid Crystal display element

[ example 3]

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

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

2. Evaluation of coatability

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

3. Evaluation of film hardness

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

Production of VA type liquid Crystal display device (1)

The prepared liquid crystal aligning agent (AL-3) was coated on the transparent electrode surface of the glass substrate with the transparent electrode including the ITO film using a spinner, and pre-baked for 1 minute using a hot plate at 80 ℃. Thereafter, the resultant was heated at 230 ℃ for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen gas, thereby forming a coating film having a thickness of 0.1 μm. The operation was repeated, thereby producing a pair (two sheets) of substrates having liquid crystal alignment films.

An epoxy adhesive containing alumina balls having a diameter of 3.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of one of the substrates by screen printing, and then the surfaces of the liquid crystal alignment films were superimposed and pressure-bonded so as to face each other, thereby curing the adhesive. Then, a VA liquid crystal display element a was manufactured by filling negative type liquid crystal (MLC-6608 manufactured by Merck) between a pair of substrates from a liquid crystal injection port, sealing the liquid crystal injection port with an acrylic photo-curing adhesive, and attaching polarizing plates to both outer surfaces of the substrates.

Production of VA type liquid Crystal display device (2)

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

6. Evaluation of liquid Crystal alignment Properties

The VA liquid crystal display element A, VA type liquid crystal display element B thus manufactured was evaluated for liquid crystal alignment properties in the same manner as in example 1. As a result, in the above examples, the VA liquid crystal display element A, VA type liquid crystal display element B had the liquid crystal alignment property "a".

7. Evaluation of Voltage Holding Ratio (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 VA mode liquid crystal display element A, VA mode liquid crystal display element B was evaluated for the voltage holding ratio "a".

[ example 4]

Liquid crystal aligning agents were prepared at the same solid content concentration as in example 1, except that the formulation composition was changed as shown in table 2 below. The obtained liquid crystal aligning agent was used to evaluate coatability and film hardness of the liquid crystal aligning agent in the same manner as in example 1, and a VA mode liquid crystal display element A, VA mode liquid crystal display element B was produced in the same manner as in example 3 and subjected to various evaluations. The results are shown in table 3 below.

< production and evaluation of PSA type liquid Crystal display element >

[ example 6]

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

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

2. Evaluation of coatability

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

3. Evaluation of film hardness

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

4. Preparation of liquid Crystal composition

A liquid crystal composition LC1 was obtained by adding 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) to 10g of a nematic liquid crystal (MLC-6608 manufactured by Merck).

[ solution 20]

Production of PSA type liquid Crystal display element (1)

The thus prepared liquid crystal aligning 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 japanese portrait printing (jet)), and after removing the solvent by heating (pre-baking) for 2 minutes on a hot plate at 80 ℃, heating (post-baking) for 10 minutes on a hot plate at 230 ℃ was performed to form a coating film having an average film thickness of 0.06 μm. These coating films were subjected to ultrasonic cleaning in ultrapure water for 1 minute and then dried in a clean oven at 100 ℃ for 10 minutes, thereby obtaining a pair (two sheets) of substrates having liquid crystal alignment films. The electrode pattern used is the same kind of pattern as the electrode pattern in the PSA mode.

Then, an epoxy adhesive 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 substrates were stacked with the liquid crystal alignment films facing each other and pressure bonded to each other to cure the adhesive. Then, the prepared liquid crystal composition LC1 was filled between a pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive, thereby producing 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 state of liquid crystal driving, an ultraviolet irradiation apparatus using a metal halide lamp as a light source was used at 100,000J/m²The irradiation amount of (3) is irradiated with ultraviolet rays. The irradiation dose is a value measured by using a light meter that measures with a wavelength of 365nm as a reference. Then, polarizing plates were bonded to both outer surfaces of the substrate so that the polarization directions of the polarizing plates were orthogonal to each other and that an angle of 45 ° was formed between the optical axis of the ultraviolet ray of the liquid crystal alignment film and the projection direction of the substrate surface, thereby producing a PSA-type liquid crystal display element a.

Production of PSA type liquid Crystal display element (2)

The same operation as in 5 above was performed except that the post-baking temperature was changed from 230 ℃ to 150 ℃, thereby producing a PSA-type liquid crystal display element B.

7. Evaluation of liquid Crystal alignment Properties

The PSA liquid crystal display element A, PSA liquid crystal display element B thus produced was evaluated for liquid crystal alignment properties 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 Ratio (VHR)

The voltage holding ratio of the PSA liquid crystal display device A, PSA liquid crystal display device B thus manufactured was evaluated 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 device A, PSA type liquid crystal display device B were all evaluated as "a".

Example 7, example 13 and example 14

Liquid crystal aligning agents were obtained by preparing the liquid crystal alignment agent at the same solid content concentration as in example 1, except that the formulation composition was changed as shown in table 2 below. The obtained liquid crystal aligning agent was used to evaluate 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.

< production and evaluation of optical vertical liquid Crystal display element >

[ example 15]

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

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

2. Evaluation of coatability

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

3. Evaluation of film hardness

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

4. Production of optical vertical liquid Crystal display device (1)

The prepared liquid crystal aligning agent (AL-15) was coated on the transparent electrode surface of the glass substrate with the transparent electrode including the ITO film using a spinner, and pre-baked for 1 minute using a hot plate at 80 ℃. Thereafter, the resultant was heated at 230 ℃ for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen gas, thereby forming a coating film having a thickness of 0.1 μm. Then, the substrate was tilted at 40 ° from the normal line of the substrate by using an Hg — Xe lamp and a glan-taylor prism (glan-taylor prism)Irradiating the surface of the coating film with polarized ultraviolet light of 1,000J/m containing 313nm bright line²Thereby imparting orientation capability to the liquid crystal. The same operation was repeated to produce a pair (two sheets) of substrates having liquid crystal alignment films.

An epoxy resin adhesive containing alumina balls having a diameter of 3.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of one of the substrates by screen printing, and then the liquid crystal alignment films of the pair of substrates were opposed to each other, and pressure-bonded so that the optical axes of the ultraviolet rays of the respective substrates were antiparallel to the projection direction of the substrate surfaces, and the adhesive was heat-cured at 150 ℃ for 1 hour. Then, a negative type liquid crystal (MLC-6608 manufactured by Merck) was filled in the gap between the substrates from the 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 mixture was heated at 130 ℃ and then gradually cooled to room temperature. Then, polarizing plates were bonded to both outer surfaces of the substrate so that the polarization directions of the polarizing plates were orthogonal to each other and that an angle of 45 ° was formed between the optical axis of the ultraviolet ray of the liquid crystal alignment film and the projection direction of the substrate surface, thereby producing an optical homeotropic liquid crystal display element a.

5. Production of optical vertical liquid Crystal display device (2)

The same operation as in 4 above was performed except that the post-baking temperature was changed from 230 ℃ to 150 ℃, thereby manufacturing an optical vertical liquid crystal display element B.

6. Evaluation of liquid Crystal alignment Properties

The liquid crystal alignment properties of the manufactured optical vertical liquid crystal display element a and optical vertical liquid crystal display element 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 optical vertical liquid crystal display element a and the optical vertical liquid crystal display element B were both "a".

7. Evaluation of Voltage Holding Ratio (VHR)

The voltage holding ratio of the manufactured optical homeotropic mode liquid crystal display device was evaluated in the same manner as in example 1. As a result, in the examples, the voltage holding ratios of the optical vertical liquid crystal display device a and the optical vertical liquid crystal display device B were evaluated as "a".

Examples 16 to 25 and comparative examples 1 to 6

Liquid crystal aligning agents were obtained by preparing the liquid crystal alignment agent at the same solid content concentration as in example 1, except that the formulation composition was changed as shown in table 2 below. Further, using each liquid crystal aligning agent, coatability and film hardness of the liquid crystal aligning agent were evaluated in the same manner as in example 1, and an optical homeotropic liquid crystal display element a and an optical homeotropic liquid crystal display element B were produced in the same manner as in example 15, and subjected to various evaluations. These results are shown in table 3 below. In Table 2, "-" means that the compounds in the column are not used.

[ Table 2]

[ Table 3]

As shown in table 3, in examples 1 to 125 using the liquid crystal aligning agent containing the compound [ W ] as a crosslinking agent, coatability was evaluated as "a" and example 14 was evaluated as "B" except for example 14. In examples 1 to 25, the liquid crystal alignment properties and the voltage holding ratios of the obtained liquid crystal display devices were also good, and the evaluation of "S", "a", or "B" was performed. In particular, in example 17 using the diamine rich (diamine rich) polymer (P-12), the evaluation that the voltage holding ratio is "S" was particularly excellent when the post-baking temperature was set to 150 ℃. On the other hand, in example 22 using the acid anhydride-enriched polymer (P-13), the voltage holding ratio was evaluated as "B" with the post-baking temperature set to 150 ℃.

On the other hand, in comparative example 1 not containing a 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 property and the voltage holding ratio was "a" or "B" when the post-baking temperature was 230 ℃.

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

Claims

1. A liquid crystal aligning agent comprising: a polymeric component; and a heterocyclic ring-containing compound having a partial structure in which at least 2 hydrogen atoms (n is an integer of 1 or more) are removed from the structure represented by the following formula (1) in one molecule;

[ solution 1]

(in the formula (1), X¹Is any one of the groups represented by the following formulae (2-1) to (2-5); a. the¹Is a divalent organic group, and may be bonded to other ring structures to form a fused ring together with the other ring structures; a plurality of A in one molecule¹And X¹Each independently having the definition);

[ solution 2]

In (formulae (2-1) to (2-5), R¹～R⁷Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 or more carbon atoms; the "+" in the formulae (2-3) and (2-5) represents a bond to the oxygen atom in the formula (1).

2. The liquid crystal aligning agent according to claim 1, wherein the heterocyclic ring-containing compound is a compound having 2 or more partial structures represented by each of the following formulae (3-1) to (3-9) in one molecule;

[ solution 3]

(formula (3-1) to (3-9) wherein R⁵¹～R⁷¹Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 24 carbon atoms; wherein R is⁵¹～R⁵⁴Any one of (1), R⁵⁵～R⁵⁷Any one of (1), R⁶⁰～R⁶²Any one of (1), R⁶³And R⁶⁴Any one of (1), R⁶⁶～R⁶⁸Any one of (1) and R⁶⁹And R⁷⁰Any of which is a bond; multiple R in one molecule⁵¹～R⁷¹Each independently has the definition; ") represents a bond.

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

[ solution 4]

(in the formula (7-1), A²¹Is a single bond or a divalent organic group having 1 or more carbon atoms, Y¹Is a protecting group, R²¹～R²³Each 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), Y²Is a protecting group; in the formula (7-3), R²⁴And R²⁵Each independently is a divalent hydrocarbon group, Y³Is a protecting group; ") represents a bond.

4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polymer component comprises a polymer having a primary amino group at a terminal.

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

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

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

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 5 to each substrate surface of a pair of substrates and irradiating the applied substrate surface with light to thereby impart liquid crystal aligning ability and form a liquid crystal alignment film; and

and a step of configuring a liquid crystal cell by disposing the pair of substrates on which the liquid crystal alignment films are formed, in opposition to each other with the application surfaces of the substrates facing each other through a liquid crystal layer.

9. 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 5 to the conductive film of each of a pair of substrates having a conductive film;

a step of configuring a liquid crystal cell by disposing a pair of substrates coated with the liquid crystal aligning agent in opposition to each other with their coating surfaces facing each other through a liquid crystal layer; and

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