CN105733610B - Composition containing polyamic acid polymer, liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display element - Google Patents

Abstract

The invention provides a composition containing a polyamic acid polymer with good printing performance, a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element. The composition containing a polyamic acid polymer contains at least one polymer (A) selected from the group consisting of a polyamic acid, a polyimide, and a polyamic acid ester, and a solvent containing a specific solvent (B) which is at least one selected from the group consisting of a compound represented by the following formula (B-1A), a compound represented by the following formula (B-1B), a compound represented by the following formula (B1), and a compound represented by the following formula (B2).

Description

Composition containing polyamic acid polymer, liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display element

Technical Field

The present invention relates to a composition containing a polyamic acid polymer, a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element.

Background

Conventionally, a liquid crystal alignment film of a display device, a surface protective film for a display device or a lighting device, an interlayer insulating film, and the like have been produced by coating a polymer composition on a substrate. For example, as liquid crystal display elements, various liquid crystal display elements of various driving methods having different electrode structures, physical properties of liquid crystal molecules used, and the like have been developed, and various liquid crystal display elements such as Twisted Nematic (TN) type, Super Twisted Nematic (STN) type, Vertical Alignment (VA) type, In-Plane Switching (IPS) type, Fringe Field Switching (FFS) type, and Optically Compensated Bend (OCB) type are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. Polyamic acid or polyimide is generally used as a material of the liquid crystal alignment film, from the viewpoint of satisfactory properties such as heat resistance, mechanical strength, and affinity for liquid crystal.

In a polymer composition such as a liquid crystal aligning agent, a polymer component is dissolved in a solvent, and the liquid crystal aligning agent is applied to a substrate and heated to form a liquid crystal alignment film. For the purpose of uniformly dissolving the polymer, an aprotic polar solvent such as N-methyl-2-pyrrolidone or γ -butyrolactone is generally used as the solvent for the liquid crystal aligning agent. In order to improve the coating property (printability) of the liquid crystal aligning agent when the liquid crystal aligning agent is coated on a substrate, a solvent for the liquid crystal aligning agent is usually used in combination with a good solvent such as polyamic acid and a poor solvent having a relatively low surface tension such as butyl cellosolve (for example, see patent document 1 or patent document 2).

In recent years, liquid crystal display elements have been used not only for display terminals such as personal computers as in the past, but also for various applications such as liquid crystal televisions, car navigation systems (car navigation systems), cellular phones, smart phones, and information displays. With such a multipurpose use, further improvement in display quality and improvement in product yield are required of liquid crystal display elements, and improvement in driving systems and element structures as well as improvement in liquid crystal alignment films as one constituent member of liquid crystal display elements and liquid crystal alignment agents as a material for forming the liquid crystal alignment films have been carried out. For example, from the viewpoint of display quality, yield, and the like, a liquid crystal alignment agent is required to have good coatability (printability) when coated on a substrate, and various materials for improving printability have been proposed (for example, see patent document 3 or patent document 4).

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent application laid-open No. 2010-97188

[ patent document 2] Japanese patent application laid-open No. 2010-156934

[ patent document 3] Japanese patent laid-open publication No. 2011-

[ patent document 4] Japanese patent application laid-open No. 2011-257736

Disclosure of Invention

[ problems to be solved by the invention ]

There is a further increasing demand for higher performance and higher yield of liquid crystal display devices, and further improvement in printability of liquid crystal aligning agents is also demanded.

The present invention has been made in view of the above problems, and a main object thereof is to provide a composition and a liquid crystal aligning agent having good printability, and a liquid crystal alignment film and a liquid crystal display element produced using the liquid crystal aligning agent.

[ means for solving problems ]

The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, have found that the problems can be solved by using a specific solvent as at least a part of a solvent component in a composition containing a polyimide or a precursor thereof as a polymer component, thereby completing the present invention. Specifically, the present invention provides the following composition, liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element.

The 1 st aspect of the present invention provides a composition containing at least one polymer (a) selected from the group consisting of polyamic acids, polyimides, and polyamic acid esters, and a solvent containing a specific solvent (B) which is at least one selected from the group consisting of a compound represented by the following formula (B-1A), a compound represented by the following formula (B-1B), a compound represented by the following formula (B1), and a compound represented by the following formula (B2). In addition, the 2 nd aspect of the present invention is to provide a liquid crystal aligning agent containing the polymer (a) and a solvent, the solvent containing the specific solvent (B).

[ solution 1]

A-X-B-Y-C¹ (b-1A)

(in the formula (b-1A), X, Y each independently represents-COO-or-OCO-, A, C¹Independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, and B represents a divalent hydrocarbon group having 1 to 12 carbon atoms)

[ solution 2]

(in the formula (B-1B), R¹、R²Each independently is an alkyl group having 3 to 6 carbon atoms, R³Each independently is a hydrogen atom or a methyl group, n4 is 2 or 3)

[ solution 3]

(in the formula (b1), R is C1-3 alkyl, n is 0-2 integer; in the formula (b2), m is 0-2 integer)

When the composition and the liquid crystal aligning agent contain the specific solvent (B) as a solvent component, the coating property (printability) to a substrate is good. The composition of the present invention can be suitably used for an insulating film or a protective film for a display device or an illumination device, in addition to the liquid crystal alignment film.

In one embodiment of the composition and the liquid crystal aligning agent of the present invention, the solvent contains a compound represented by the formula (b-1A). In another embodiment of the composition and the liquid crystal aligning agent of the present invention, the solvent contains a compound represented by the formula (B-1B). In these cases, precipitates are less likely to be formed in the composition or in the aligning agent even when the composition is stored for a long period of time in a low-temperature environment, and the storage stability is good. In addition, the composition or the liquid crystal aligning agent has good coating property on the substrate. Further, a liquid crystal display element exhibiting good display quality can be obtained even if the liquid crystal display element is narrowed in edge.

In another embodiment of the composition and the liquid crystal aligning agent of the present invention, the solvent contains a compound represented by the formula (b1) or the formula (b 2). In this case, the solubility of the polymer in the solvent is good. Further, the boiling point of the compound represented by the formula (b1) or the formula (b2) is appropriately high, and thus, when the composition or the liquid crystal aligning agent is printed on a substrate, the solvent can be prevented from being volatilized from a printer. Therefore, the polymer component is less likely to be deposited on the printing machine, and as a result, the printability (particularly, printability when printing is continued for a long period of time is hereinafter referred to as "long-term printability") can be improved.

In the liquid crystal aligning agent of the present invention, the polymer (A) preferably contains a polymer having a partial structure derived from at least one diamine selected from the group consisting of compounds represented by the following formulae (d-1) to (d-5).

[ solution 4]

(in the formula (d-1), X¹And X²Each independently being a single bond, -O-, -S-, -OCO-or-COO-, Y¹Is an oxygen atom or a sulfur atom, R¹¹And R¹²Each independently is C1-C3 alkanediyl, R⁸And R⁹Each independently is a hydrogen atom or a protecting group; n1 is 0 or 1, n2 and n3 are integers satisfying n2+ n3 ═ 2 in the case where n1 is 0, and n2 is n3 ═ 1 in the case where n1 is 1; in the formula (d-2), X³Is a single bond, -O-or-S-, and m1 is an integer of 0-3; when m1 is 0, m2 is 1-12 integersWhen m1 is an integer of 1-3, m2 is 2; in the formula (d-3), R³Is C1-12 monovalent hydrocarbon group, R⁴Is a hydrogen atom or a C1-12 monovalent hydrocarbon group, R⁵And R⁶Each independently is a hydrogen atom or a methyl group; in the formula (d-4), X⁴And X⁵Each independently is a single bond, -O-, -COO-or-OCO-, R⁷Is C1-3 alkanediyl, A⁴is a single bond or an alkanediyl group having 1 to 3 carbon atoms; a is 0 or 1, b is an integer of 0-2, c is an integer of 1-20, and k is 0 or 1; wherein a and b are not both 0; in the formula (d-5), A⁵Represents a single bond, an alkanediyl group having 1 to 12 carbon atoms or a fluoroalkanediyl group having 1 to 6 carbon atoms, A⁶represents-O-, -COO-, -OCO-, -NHCO-, -CONH-or-CO-, A⁷Represents a monovalent organic group having a steroid skeleton)

When at least a part of the polymer component of the liquid crystal aligning agent is the polymer (a) obtained by using the specific diamine, the above-mentioned effect is high and is preferable.

The liquid crystal aligning agent of the present invention may further contain an amine compound (C) having 1 primary amino group and a nitrogen-containing aromatic heterocycle in the molecule, wherein the primary amino group is bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group.

In the case where the amine compound (C) is contained as an additive in the liquid crystal aligning agent containing the polymer (a) as at least a part of the polymer component, there is a case where a problem such as precipitation of the amine compound (C) in the aligning agent occurs when the liquid crystal aligning agent is stored in a low-temperature environment for a long time. In this respect, according to the liquid crystal aligning agent of the present configuration, by containing the specific solvent (B) as a solvent component, precipitates are less likely to be generated in the aligning agent even when the liquid crystal aligning agent is stored for a long time in a low temperature environment, and the storage stability is good. In addition, the liquid crystal aligning agent has good coating property on the substrate.

The 3 rd aspect of the present invention is to provide a liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention. In addition, the 4 th aspect of the present invention is to provide a liquid crystal display element including the liquid crystal alignment film. The liquid crystal alignment film is formed by using a liquid crystal alignment agent with good printing performance, so that the yield of the liquid crystal display element can be improved.

Drawings

Fig. 1 is a schematic configuration diagram of an FFS type liquid crystal cell.

fig. 2(a) and 2(b) are schematic plan views of a top electrode used for manufacturing a liquid crystal display element by a photo-alignment method. Fig. 2(a) is a plan view of the top electrode, and fig. 2(b) is a partially enlarged view of the top electrode.

Fig. 3 is a diagram showing four systems of drive electrodes.

[ description of symbols ]

10: liquid crystal display element

11a, 11 b: glass substrate

12: liquid crystal alignment film

13: top electrode

14: insulating layer

15: bottom electrode

16: liquid crystal layer

A. B, C, D: electrode for electrochemical cell

d 1: line width of electrode

d 2: distance between electrodes

C1: portion surrounded by dotted line

Detailed Description

Composition and liquid crystal aligning agent

the composition and the liquid crystal aligning agent of the present invention include at least one polymer (a) selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester as a polymer component, and the polymer (a) is prepared as a liquid composition dispersed or dissolved in a solvent. The composition of the present invention is preferably a liquid crystal aligning agent.

Polymer (A)

< Polyamic acid >

The polyamic acid of the present invention can be obtained by reacting tetracarboxylic dianhydride with diamine.

[ tetracarboxylic 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. As specific examples of these tetracarboxylic dianhydrides,

Examples of the aliphatic tetracarboxylic dianhydride include: 1,2,3, 4-butanetetracarboxylic dianhydride, etc.;

Examples of the alicyclic tetracarboxylic dianhydride include: 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3, 5-tricarboxylic cyclopentylacetic dianhydride, 1,3,3a,4,5,9 b-hexahydro-5- (tetrahydro-2, 5-dioxo-3-furyl) -naphtho [1,2-c]Furan-1, 3-dione, 1,3,3a,4,5,9 b-hexahydro-8-methyl-5- (tetrahydro-2, 5-dioxo-3-furyl) -naphtho [1,2-c]Furan-1, 3-dione, 3-oxabicyclo [3.2.1]Octane-2, 4-dione-6-spiro-3 ' - (tetrahydrofuran-2 ',5' -dione), 5- (2, 5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic anhydride, 3,5, 6-tricarboxyl-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 4, 9-dioxatricyclo [5.3.1.0 ]^2,6]Undecane-3, 5,8, 10-tetraone, cyclohexanetetracarboxylic dianhydride, a compound represented by the following formula (t-1), and the like [ formula 5]]

(in the formula (t-1), X⁷、X⁸、X⁹And X¹⁰Each independently is a single bond or methylene, and j is an integer of 1 to 3);

Examples of the aromatic tetracarboxylic dianhydride include: pyromellitic dianhydride, etc.; in addition, tetracarboxylic dianhydrides described in Japanese patent application laid-open No. 2010-97188 can be used. Further, the tetracarboxylic dianhydride may be used singly or in combination of two or more thereof.

examples of the compound represented by the formula (t-1) include: bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride, bicyclo [4.3.0] nonane-2, 4,7, 9-tetracarboxylic dianhydride, bicyclo [4.4.0] decane-2, 4,8, 10-tetracarboxylic dianhydride, tricyclo [6.3.0.0 < 2,6 > ] undecane-3, 5,9, 11-tetracarboxylic dianhydride, and the like. Among them, the compound represented by the formula (t-1) is preferably bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride from the viewpoint of improving the stability of liquid crystal alignment in the use of a liquid crystal alignment film.

The tetracarboxylic dianhydride used for synthesizing the polyamic acid is preferably at least one compound selected from the group consisting of the following compounds (hereinafter also referred to as a specific tetracarboxylic dianhydride): the compound represented by the formula (t-1), 2,3, 5-tricarboxylic cyclopentyl acetic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride and pyromellitic dianhydride. When the specific tetracarboxylic dianhydride is used, the total amount of the specific tetracarboxylic dianhydride used is preferably 10 mol% or more, and more preferably 20 mol% to 100 mol% based on the total amount of the tetracarboxylic dianhydride used for synthesizing the polyamic acid. Further, by polymerization including a specific tetracarboxylic dianhydride in the monomer composition, a polymer having a partial structure derived from the specific tetracarboxylic dianhydride is obtained.

[ diamine ]

The diamine used for the synthesis of the polyamic acid preferably contains at least one diamine (hereinafter, also referred to as "specific diamine") selected from the group consisting of the compound represented by the formula (d-1), the compound represented by the formula (d-2), the compound represented by the formula (d-3), the compound represented by the formula (d-4), and the compound represented by the formula (d-5).

(Compound represented by the formula (d-1))

In the formula (d-1), R¹¹And R¹²examples of the C1-3 alkanediyl group include: methylene, ethylene, propane-1, 2-diyl, propane-1, 3-diyl, propane-2, 3-diyl, and the like. Among these alkanediyl groups, a methylene group, an ethylene group, or a propane-1, 3-diyl group is preferable.

X¹And X²Is a single bond, -O-, -S-, -OCO-or-COO-. Further, X¹And X²May be the same or different. In these radicals, X¹And X²Preferably a single bond, -O-or-S-.

Y¹Is an oxygen atom or a sulfur atom. Preferably an oxygen atom.

R⁸And R⁹The protecting group(s) is preferably a group which is thermally cleaved, e.g.Examples thereof include: urethane-based protecting groups, amide-based protecting groups, imide-based protecting groups, sulfonamide-based protecting groups, and the like. Wherein R is⁸And R⁹The protective group (b) is preferably a urethane-based protective group, and specific examples thereof include: t-butoxycarbonyl, benzyloxycarbonyl, 1-dimethyl-2-haloethoxycarbonyl, 1-dimethyl-2-cyanoethoxycarbonyl, 9-fluorenylmethoxycarbonyl, allyloxycarbonyl, 2- (trimethylsilyl) ethoxycarbonyl and the like. Among these, tert-butoxycarbonyl is particularly preferable from the viewpoint of high release by heat or from the viewpoint of being able to reduce the amount of remaining in the film of the deprotected portion.

When n1 is 0, the 2 primary amino groups of the compound represented by formula (d-1) may be bonded to the same benzene ring, or 1 may be bonded to each of 2 different benzene rings. On the other hand, when n1 is 1,1 primary amino group is bonded to each of 2 different benzene rings.

The bonding position of the primary amino group on the benzene ring is not particularly limited. For example, when the number of primary amino groups on the benzene ring is 1, the bonding position may be any of 2-, 3-and 4-positions, preferably 3-or 4-and more preferably 4-relative to the other groups. When the number of primary amino groups on the benzene ring is 2, the bonding position to other groups includes, for example, the 2, 4-position and the 2, 5-position, and among these, the 2, 4-position is preferable.

The hydrogen atom on the benzene ring bonded with the primary amino group may be substituted by a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent group in which at least one hydrogen atom on the hydrocarbon group is substituted by a fluorine atom, or a fluorine atom. Examples of the monovalent hydrocarbon group in this case include: an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 5 to 10 carbon atoms (e.g., phenyl group, tolyl group, etc.), an aralkyl group having 5 to 10 carbon atoms (e.g., benzyl group, etc.), and the like.

The term "hydrocarbon group" as used herein includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that do not include a cyclic structure in the main chain and are composed of only a chain structure. The chain structure may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. The alicyclic hydrocarbon structure does not need to be constituted solely, and a part thereof may have a chain structure. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. In addition, the structure may not be composed of only an aromatic ring structure, and a part thereof may contain a chain structure or an alicyclic hydrocarbon structure.

As preferable specific examples of the compound represented by the formula (d-1), compounds in which n1 is 0 include, for example: 4,4' -diaminodiphenylamine, 2, 4-diaminodiphenylamine, and the like; examples of compounds having 1 as n1 include: 1,3-bis (4-aminobenzyl) urea, 1,3-bis (4-aminophenylethyl) urea, 1,3-bis (3-aminobenzyl) urea, 1- (4-aminobenzyl) -3- (4-aminophenylethyl) urea, 1,3-bis (2- (4-aminophenoxy) ethyl) urea, 1,3-bis (3- (4-aminophenoxy) propyl) urea, 1,3-bis (4-aminobenzyl) thiourea, 1,3-bis (2-aminobenzyl) urea, 1,3-bis (2-aminophenylethyl) urea, 1,3-bis (2- (2-aminobenzoyloxy) ethyl) urea, 1,3-bis (3- (2-aminobenzoyloxy) propyl) urea and the like. Further, the compounds represented by the formula (d-1) may be used singly or in combination of two or more kinds.

(Compound represented by the formula (d-2))

In the formula (d-2), X³Is a single bond, -O-or-S-, preferably a single bond or-O-.

When m1 is 0, m2 is an integer of 1 to 12. In this case, m2 is preferably 1 to 10, more preferably 1 to 8, from the viewpoint of improving the heat resistance of the resulting polymer. In the application of the liquid crystal alignment film, in terms of maintaining good liquid crystal alignment properties and improving rubbing resistance, m1 is preferably 0, and in terms of reducing the pretilt angle of the liquid crystal molecules, m1 is preferably an integer of 1 to 3.

The bonding position of the primary amino group on the benzene ring is not particularly limited, and each primary amino group is preferably in the 3-position or 4-position, more preferably in the 4-position, with respect to the other groups. In addition, the hydrogen atom on the benzene ring bonded with the primary amino group can be replaced by C1-10 monovalent hydrocarbon group, or at least one hydrogen atom on the hydrocarbon group can be replaced by fluorine atom or fluorine atom.

Preferable specific examples of the compound represented by the formula (d-2) include: bis (4-aminophenoxy) methane, bis (4-aminophenoxy) ethane, bis (4-aminophenoxy) propane, bis (4-aminophenoxy) butane, bis (4-aminophenoxy) pentane, bis (4-aminophenoxy) hexane, bis (4-aminophenoxy) heptane, bis (4-aminophenoxy) octane, bis (4-aminophenoxy) nonane, bis (4-aminophenoxy) decane, bis (4-aminophenyl) methane, bis (4-aminophenyl) ethane, bis (4-aminophenyl) propane, bis (4-aminophenyl) butane, bis (4-aminophenyl) pentane, bis (4-aminophenyl) hexane, bis (4-aminophenyl) heptane, bis (4-aminophenyl) octane, bis (4-aminophenoxy) heptane, Bis (4-aminophenyl) nonane, bis (4-aminophenyl) decane, 1,3-bis (4-aminophenylmercapto) propane, 1, 4-bis (4-aminophenylmercapto) butane, and the like. In addition, the compounds represented by the formula (d-2) may be used singly or in combination of two or more of these exemplified compounds.

(Compound represented by the formula (d-3))

In the formula (d-3), R³Is a C1-12 monovalent hydrocarbon group. R³Specific examples of (b) include: alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, and decyl; alkenyl groups such as vinyl and allyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl and tolyl; aralkyl groups such as benzyl group, etc. R³The carbon number of (b) is preferably 1 to 6, more preferably 1 to 3. R³The chain hydrocarbon group is preferably a chain hydrocarbon group, more preferably a chain hydrocarbon group containing a carbon-carbon double bond, and particularly preferably an alkenyl group.

R⁴Is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include: chain hydrocarbon group having 1 to 12 carbon atoms, alicyclic hydrocarbon group having 3 to 12 carbon atoms, aromatic hydrocarbon group having 5 to 12 carbon atoms, and specific examples thereof include the R³The groups exemplified in the description of (1). R⁴Preferably a hydrogen atom or a chain hydrocarbon group having 1 to 12 carbon atoms. In addition, R⁴the hydrocarbon group of (2) is preferably C16, more preferably 1 to 3 carbon atoms.

R⁵and R⁶Each independently is a hydrogen atom or a methyl group, preferably both are hydrogen atoms.

the bonding position of the 2 primary amino groups in the diaminophenyl group of the formula (d-3) is not particularly limited, but the 2, 4-position or the 2, 5-position is preferable, and the 2, 4-position is more preferable, with respect to the group having an N-allyl structure bonded to the benzene ring. In addition, the hydrogen atom on the benzene ring bonded with the primary amino group can be replaced by C1-10 monovalent hydrocarbon group, or at least one hydrogen atom on the hydrocarbon group can be replaced by fluorine atom or fluorine atom.

Preferable specific examples of the compound represented by the formula (d-3) include: 2, 4-diamino-N, N-diallylaniline, 2, 5-diamino-N, N-diallylaniline, the following formula (d-3-1) to (d-3-3) respectively represented by the compounds. Further, the compound represented by the formula (d-3) may be used singly or in combination of two or more.

[ solution 6]

(Compound represented by the formula (d-4))

In the formula (d-4), "-X⁴-(R⁷-X⁵)_kThe divalent group represented by- "is preferably C1-3 alkanediyl, O-, -COO-or O-C₂H₄-O- (wherein the bond marked "", is bonded to the diaminophenyl group).

radical-C_cH_2c+1"is preferably linear, and specific examples thereof include: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl and the like.

Relative to the radical "X⁴", the 2 primary amino groups in the diaminophenyl group are preferably in the 2, 4-or 3, 5-positions,More preferably 2, 4-bits. In addition, the hydrogen atom on the benzene ring bonded with the primary amino group can be replaced by C1-10 monovalent hydrocarbon group, or at least one hydrogen atom on the hydrocarbon group can be replaced by fluorine atom or fluorine atom.

Preferable specific examples of the compound represented by the formula (d-4) include compounds represented by the following formulae (d-4-1) to (d-4-12), respectively.

[ solution 7]

(Compound represented by the formula (d-5))

In the formula (d-5), A⁵Represents a single bond, an alkanediyl group having 1 to 12 carbon atoms or a fluoroalkanediyl group having 1 to 6 carbon atoms, A⁶represents-O-, -COO-, -OCO-, -NHCO-, -CONH-or-CO-, A⁷Represents a monovalent organic group having a steroid skeleton.

A of the formula (d-5)⁵The C1-C12 alkanediyl group is preferably a C1-C4 alkanediyl group, and more preferably a methylene group, an ethylene group, a 1, 3-propanediyl group, or a 1, 4-butanediyl group. The C1-6 fluoroalkanediyl group is preferably C1-4 perfluoroalkanediyl group, more preferably-CF₂-, perfluoroethylene, 1, 3-perfluoropropanediyl and 1, 4-perfluorobutanediyl.

A⁶preferably-O-.

So-called A⁷The steroid skeleton of (a) means a structure containing a core of cyclopentane polyhydrophenanthrene (cyclopentane hydrophenanthrene) or a structure in which one or more carbon-carbon bonds thereof are double bonds. The monovalent organic group having a steroid skeleton is preferably an organic group having 17 to 40 carbon atoms.

In the application of the liquid crystal alignment film, from the viewpoint of imparting a high pretilt angle to the coating film, a preferable specific example of the compound represented by the formula (d-5) is preferably one or more selected from the group consisting of: 1-cholesteryloxymethyl-2, 4-diaminobenzene, 1-cholesteryloxymethyl-3, 5-diaminobenzene, 1- (1-cholesteryloxy-1, 1-difluoromethyl) -2, 4-diaminobenzene, 1- (1-cholesteryloxy-1, 1-difluoromethyl) -3, 5-diaminobenzene, 1- (1-cholestayloxy-1, 1-difluoromethyl) -2, 4-diaminobenzene, 1- (1-cholestayloxy-1, 1-difluoromethyl) -3, 5-diaminobenzene, 3- (2, 4-diaminophenylmethoxy) -4, 4-dimethylcholestane, and mixtures thereof, 3- (1- (2, 4-diaminophenyl) -1, 1-difluoromethoxy) -4, 4-dimethylcholestane, 3- (3, 5-diaminophenylmethoxy) -4, 4-dimethylcholestane, 3- (1- (3, 5-diaminophenyl) -1, 1-difluoromethoxy) -4, 4-dimethylcholestane, hexadecyl 3- ((2, 4-diaminophenyl) methoxy) cholane-24-oate, hexadecyl 3- (1- (2, 4-diaminophenyl) -1, 1-difluoromethoxy) cholane-24-oate, hexadecyl 3- ((3, 5-diaminophenyl) methoxy) cholane-24-oate, hexadecyl (di-n-butyl) cholane-3- ((3, 5-diaminophenyl) methoxy) cholane-24-oate, Hexadecyl 3- (1- (3, 5-diaminophenyl) -1, 1-difluoromethoxy) cholane-24-oate, octadecyl 3- (2, 4-diaminophenylmethoxy) cholane-24-oate, octadecyl 3- (1- (2, 4-diaminophenyl) -1, 1-difluoromethoxy) cholane-24-oate, octadecyl 3- (3, 5-diaminophenylmethoxy) cholane-24-oate, octadecyl 3- (1- (3, 5-diaminophenyl) -1, 1-difluoromethoxy) cholane-24-oate, 1-cholesteryloxy-2, 4-diaminobenzene, 3, among these, from the viewpoint of providing a high pretilt angle at a small usage ratio, it is particularly preferable to use one or more selected from the group consisting of 1-cholesteryloxy-2, 4-diaminobenzene, 3,5-diaminobenzoic acid cholesteryl ester, 1-cholesteryloxy-2, 4-diaminobenzene, and 3,5-diaminobenzoic acid cholesteryl ester.

When the polyamic acid is synthesized, the specific diamine can be appropriately selected from the above-mentioned compounds and used according to the driving mode of the liquid crystal display element to be produced. Specifically, a liquid crystal aligning agent suitable for use in a Fringe Field Switching (FFS) type liquid crystal display element can be produced by using the compound represented by the formula (d-1) as the specific diamine. Further, a liquid crystal aligning agent suitable for a Twisted Nematic (TN) type liquid crystal display element can be produced by using at least one selected from the group consisting of the compound represented by the formula (d-2) and the compound represented by the formula (d-3), and a liquid crystal aligning agent suitable for a vertical alignment type liquid crystal display element can be produced by using at least one selected from the group consisting of the compound represented by the formula (d-4) and the compound represented by the formula (d-5).

(other diamines)

The diamine used for the synthesis of the polyamic acid may be a compound other than the specific diamine (other diamine). Examples of such other diamines are: aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples of these other diamines include aliphatic diamines such as: m-xylylenediamine, 1, 3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, and the like; examples of the alicyclic diamine include: 1, 4-diaminocyclohexane, 4' -methylenebis (cyclohexylamine), and the like;

Examples of the aromatic diamine include: p-phenylenediamine, 4' -diaminodiphenylsulfide, 1, 5-diaminonaphthalene, 2' -dimethyl-4, 4' -diaminobiphenyl, 2' -bis (trifluoromethyl) -4,4' -diaminobiphenyl, 2, 7-diaminofluorene, 4' -diaminodiphenyl ether, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 9-bis (4-aminophenyl) fluorene, 2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, 2-bis (4-aminophenyl) hexafluoropropane, 4' - (p-phenylenediisopropylidene) dianiline, 4' - (m-phenylenediisopropylidene) dianiline, 1, 5-diaminonaphthalene, 2' -dimethyl-4, 4' -diaminobiphenyl, 2' -bis (4-aminophenoxy) phenyl ] propane, 9-bis (4-aminophenyl) fluorene, 2, 1, 4-bis (4-aminophenoxy) benzene, 4 '-bis (4-aminophenoxy) biphenyl, 2, 6-diaminopyridine, 3, 4-diaminopyridine, 2, 4-diaminopyrimidine, 3, 6-diaminoacridine, 3, 6-diaminocarbazole, N-methyl-3, 6-diaminocarbazole, N-ethyl-3, 6-diaminocarbazole, N-phenyl-3, 6-diaminocarbazole, N' -bis (4-aminophenyl) -benzidine, N '-bis (4-aminophenyl) -N, N' -dimethylbenzidine, 1, 4-bis- (4-aminophenyl) -piperazine, 1- (4-aminophenyl) -2, 3-dihydro-1, 3, 3-trimethyl-1H-inden-5-amine, 1- (4-aminophenyl) -2, 3-dihydro-1, 3, 3-trimethyl-1H-inden-6-amine, 4- (4 '-trifluoromethoxybenzoyloxy) cyclohexyl-3, 5-diaminobenzoate, 4- (4' -trifluoromethylbenzoyloxy) cyclohexyl-3, 5-diaminobenzoate, 1-bis (4- ((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1-bis (4- ((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1-bis (4- ((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane Cyclohexane, 1-bis (4- ((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 4-aminobenzylamine, 3-aminobenzylamine, and the like;

examples of the diaminoorganosiloxanes include: 1,3-bis (3-aminopropyl) -tetramethyldisiloxane and the like; in addition, diamines described in Japanese patent application laid-open No. 2010-97188 can be used. Further, these other diamines may be used singly or in combination of two or more.

When the polymer (a) contains a polymer having a partial structure derived from a specific diamine (hereinafter also referred to as "specific polymer"), the content of the specific polymer is preferably 50 parts by weight or more, more preferably 70 parts by weight or more, particularly preferably 80 parts by weight or more, and particularly preferably 90 parts by weight or more, based on 100 parts by weight of the total amount of the polymer components contained in the composition or the liquid crystal aligning agent, from the viewpoint of printability.

When the specific amine compound (C) described in detail below is contained as an additive in the liquid crystal aligning agent of the present invention, the polymer (a) preferably contains a polymer having a partial structure derived from a diamine having a carboxyl group (hereinafter also referred to as "carboxyl group-containing diamine"). In the case where the polymer is, for example, polyamic acid, it can be obtained by using a diamine containing a carboxyl group as at least a part of the other diamine used in the synthesis of polyamic acid. The carboxyl group-containing diamine is preferably an aromatic diamine, and specific examples thereof include compounds represented by the following formulae (e1-1) and (e 1-2).

[ solution 8]

(in the formulae (e1-1) and (e1-2), R²⁰Is a halogen atom, an alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to up to 1 carbon atomsAlkoxy of 10, Z¹Is a single bond, an oxygen atom or an alkanediyl group having 1 to 3 carbon atoms; r2, r5 and r6 are each independently an integer of 1 or 2, r1, r3 and r4 are each independently an integer of 0 to 2, and r7 and r8 are each independently an integer of 0 to 2 satisfying r7+ r8 ═ 2; wherein r3+ r5+ r7 ≦ 5, r4+ r6+ r8 ≦ 5; in the formula, a plurality of R exist²⁰In the case of (2), these R' s²⁰Independently and with the definitions

With respect to the formulae (e1-1) and (e1-2), R²⁰Examples of the alkyl group having 1 to 10 carbon atoms include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and the like, and these may be straight or branched. Examples of the alkoxy group having 1 to 10 carbon atoms include: methoxy, ethoxy, propoxy, butoxy, hexyloxy, and the like.

Z¹Examples of the C1-3 alkanediyl group include: methylene, ethylene, trimethylene and the like.

r1, r3 and r4 are preferably 0 or 1, more preferably 0.

Specific examples of the carboxyl group-containing diamine include compounds represented by the following formula (e 1-1): 3,5-diaminobenzoic acid, 2, 4-diaminobenzoic acid, 2, 5-diaminobenzoic acid, etc.; examples of the compounds represented by the following formula (e1-2) include: 4,4' -diaminobiphenyl-3, 3' -dicarboxylic acid, 4' -diaminobiphenyl-2, 2' -dicarboxylic acid, 3' -diaminobiphenyl-4, 4' -dicarboxylic acid, 3' -diaminobiphenyl-2, 4' -dicarboxylic acid, 4' -diaminodiphenylmethane-3, 3' -dicarboxylic acid, 4' -diaminobiphenyl-3-carboxylic acid, 4' -diaminodiphenylmethane-3-carboxylic acid, 4' -diaminodiphenylethane-3, 3' -dicarboxylic acid, 4' -diaminodiphenylethane-3-carboxylic acid, 4' -diaminodiphenylether-3, 3' -dicarboxylic acid, and mixtures thereof, 4,4' -diaminodiphenyl ether-3-carboxylic acid, and the like.

the amount of the specific diamine used in the synthesis of the polyamic acid can be arbitrarily set according to the compound used. For example, when the compound represented by the formula (d-1) is used, the amount thereof to be used is preferably 10 mol% or more, more preferably 30 mol% or more, based on all diamines. In the case of using the compound represented by the above formula (d-2), the amount of the compound used is preferably 10 mol% or more, more preferably 30 mol% or more, and particularly preferably 50 mol% or more, based on all the diamines, from the viewpoint of providing a low tilt alignment angle to the liquid crystal molecules.

In the case of using the compound represented by the above formula (d-3), the amount thereof to be used is preferably 5 mol% or more, more preferably 10 mol% or more, with respect to all diamines, from the viewpoint of improving the stability of the voltage holding ratio.

In the case where at least one member selected from the group consisting of the compound represented by the formula (d-4) and the compound represented by the formula (d-5) is used, the amount of the diamine used (the total amount thereof in the case where two or more compounds are used) is preferably 5 mol% or more, more preferably 10 mol% or more, with respect to all diamines, from the viewpoint of imparting good orientation. In addition, one of the exemplified compounds may be used alone or two or more of them may be used in combination as the specific diamine.

When a diamine having a carboxyl group is used as the other diamine, the diamine having a carboxyl group is preferably used in a proportion of 5 mol% or more, more preferably 10 mol% to 90 mol%, and particularly preferably 10 mol% to 70 mol% based on the total amount of the diamines.

In the case of synthesizing a polyamic acid, a tetracarboxylic dianhydride and a diamine are used together with a monoamine represented by the following formula (m-1) for the purpose of providing a suitable tilt alignment angle to liquid crystal molecules.

[ solution 9]

(in the formula (m-1), R²³Is C6-20 alkyl or alkoxy, R²⁴Is a divalent organic radical, h is 0 or 1)

In the formula (m-1), R²³Examples of the alkyl group having 6 to 20 carbon atoms include: hexyl, heptyl, octyl, nonyl, decyl, dodecylTrialkyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, and the like, which may be straight or branched. Examples of the alkoxy group having 6 to 20 carbon atoms include the above-mentioned exemplified groups (-OR) in which an alkyl group having 6 to 20 carbon atoms is bonded to an oxygen atom²³) And the like.

R²⁴Examples of the divalent organic group include: divalent hydrocarbon groups such as divalent chain hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, groups having functional groups such as-O-, -CO-, -COO-, -S-between carbon-carbon bonds in the hydrocarbon groups, heterocyclic ring-containing groups, and the like. Specific examples of the divalent hydrocarbon group include a linear hydrocarbon group such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, a heptanediyl group, an octanediyl group, a nonanediyl group, a decanediyl group, an undecanediyl group, a dodecanediyl group, a tridecanediyl group, a tetradecanediyl group, a pentadecanediyl group, an octadecanediyl group, an eicosylene group, an ethenylene group, a propenediyl group, a butenediyl group, a pentenediyl group, an ethynylene group, and a propynyl group; examples of the alicyclic hydrocarbon group include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclononylene, cyclodecylene, cycloundecylene, cyclododecylene, cyclotridecylene, cyclotetradecylene, cyclopentadecylene, cyclooctadecylene, cycloeicosylene, dicyclohexylene, norbornyl, adamantylene, and the like; examples of the aromatic hydrocarbon group include: phenylene, biphenylene, and the like. Wherein R is²⁴Preferably a chain hydrocarbon group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

Preferable specific examples of the monoamine represented by the formula (m-1) include: aliphatic monoamines such as n-hexylamine, n-octylamine, n-decylamine, n-dodecylamine, n-hexadecylamine, 1, 3-dimethylbutylamine, 1, 5-dimethylhexylamine, and 2-ethylhexylamine; aromatic monoamines such as p-aminophenylhexane, p-aminophenyloctane, p-aminophenyldodecane, p-aminophenylhexadecane, p-aminophenoxyoctane, p-aminophenoxydodecane, and p-aminophenoxyhexadecane.

In order to suppress the influence of the monoamine released in the liquid crystal cell to the display characteristics, the proportion of the monoamine used is preferably such that "2 (a-b) ≧ c > 0" is satisfied when a mol of the tetracarboxylic dianhydride, b mol of the diamine, and c mol of the monoamine are used.

The monoamine represented by the formula (m-1) may be polymerized by reacting the tetracarboxylic dianhydride with the diamine after the reaction, or may be polymerized by simultaneously reacting the tetracarboxylic dianhydride with the diamine and the monoamine.

[ molecular weight modifier ]

When synthesizing the polyamic acid, the polymer having a modified terminal can be synthesized by using the tetracarboxylic dianhydride and the diamine as described above and using an appropriate molecular weight modifier. By forming the terminal-modified polymer, the coating property (printability) of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight regulators include: acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like. Specific examples of these compounds include acid monoanhydrides: maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyltutanedioic anhydride, n-dodecylbutanedioic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylbutanedioic anhydride, and the like; examples of the monoamine compound include: aniline, cyclohexylamine, n-butylamine, a compound represented by the formula (m-1), and the like; examples of monoisocyanate compounds include: phenyl isocyanate, naphthyl isocyanate, and the like.

The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total of the tetracarboxylic dianhydride and the diamine used.

< Synthesis of Polyamic acid >

The ratio of the tetracarboxylic dianhydride to the diamine used in the synthesis reaction of the polyamic acid is preferably 0.2 to 2 equivalents, more preferably 0.3 to 1.2 equivalents, of the acid anhydride group of the tetracarboxylic dianhydride to 1 equivalent of the amino group of the diamine.

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 more preferably 0 to 100 ℃. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

Examples of the organic solvent include: aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and the like.

Specific examples of these organic solvents include the following aprotic polar solvents: n-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone (1, 3-dimethyl-2-imidazolidone), N-ethyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, γ -butyrolactone, tetramethylurea, hexamethylphosphoric triamide, and the like; examples of the phenol-based solvent include: phenol, m-cresol, xylenol, halogenated phenols, and the like;

Examples of the alcohol include: methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1, 4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, etc.; examples of the ketone include: acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like; examples of the ester include: ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, and the like;

Examples of the ethers include: diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether acetate, tetrahydrofuran, diisoamyl ether, and the like;

Examples of the halogenated hydrocarbons include: dichloromethane, 1, 2-dichloroethane, 1, 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like; examples of the hydrocarbon include: hexane, heptane, octane, benzene, toluene, xylene, and the like. In addition, the specific solvent (B) may be used.

Among these organic solvents, it is preferable to use one or more selected from the group consisting of aprotic polar solvents and phenolic solvents (organic solvent a), or a mixture of one or more selected from the group consisting of organic solvents a and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvent B). In the latter case, the proportion of the organic solvent B used is preferably 50% by weight or less, more preferably 40% by weight or less, and particularly preferably 30% by weight or less, based on the total amount of the organic solvent a and the organic solvent B. 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 wt% based on the total amount (a + b) of the reaction solution.

A reaction solution obtained by dissolving the polyamide acid was obtained in the above manner. The reaction solution may be directly supplied to the preparation of a composition such as a liquid crystal aligning agent, or the polyamic acid contained in the reaction solution may be isolated and then supplied to the preparation of a liquid crystal aligning agent, or the isolated polyamic acid may be purified and then supplied to the preparation of a liquid crystal aligning agent. In the case of producing a polyimide by subjecting a polyamic acid to dehydration ring-closure, the reaction solution may be directly subjected to dehydration ring-closure reaction, the polyamic acid contained in the reaction solution may be isolated and then subjected to dehydration ring-closure reaction, or the isolated polyamic acid may be purified and then subjected to dehydration ring-closure reaction. Isolation and purification of the polyamic acid can be carried out according to a known method.

< polyimide >

The polyimide of the present invention can be obtained by subjecting the polyamic acid synthesized in the above-described manner to dehydration ring closure and imidization.

The polyimide may be a complete imide compound obtained by dehydration ring closure of the entire amic acid structure of the polyamic acid as a precursor thereof, or a partial imide compound obtained by dehydration ring closure of only a part of the amic acid structure to allow the amic acid structure and the imide ring structure to coexist. The polyimide in the present invention preferably has an imidization ratio of 30% or more, more preferably 40% to 99%, and particularly preferably 50% to 99%. The imidization ratio is expressed by percentage of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of the polyimide. 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: a method of heating the polyamic acid; or a method in which the polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydration ring-closing catalyst are added to the solution, followed by heating as necessary. Among them, the latter method is preferably used.

In the method of adding the dehydrating agent and the dehydration ring-closing catalyst to the solution of polyamic acid, the dehydrating agent may be, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles based on 1 mole of the amic acid structure of the polyamic acid. Examples of the dehydration ring-closing catalyst include: tertiary amines such as pyridine, collidine (collidine), lutidine (lutidine), and triethylamine. 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. The organic solvent used in the dehydration ring-closure reaction may be an organic solvent exemplified as an organic solvent used for synthesis of polyamic acid. The reaction temperature of the dehydration ring-closure reaction is preferably 0 to 180 ℃, more preferably 10 to 150 ℃. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

A reaction solution containing polyimide was obtained in the above manner. The reaction solution may be directly supplied for the preparation of a composition such as a liquid crystal aligning agent, or may be supplied for the preparation of a liquid crystal aligning agent after removing a dehydrating agent and a dehydration ring-closing catalyst from the reaction solution, or may be supplied for the preparation of a liquid crystal aligning agent after isolating polyimide, or may be supplied for the preparation of a liquid crystal aligning agent after purifying isolated polyimide. These purification operations may be carried out according to known methods.

< polyamic acid ester >

The polyamic acid ester contained in the composition such as a liquid crystal aligning agent of the present invention can be obtained, for example, by the following method: [I] a method of synthesizing by reacting a polyamic acid obtained by the synthesis reaction with a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, or the like; [ II ] a method for reacting a tetracarboxylic acid diester with a diamine; and [ III ] a method for reacting a tetracarboxylic acid diester dihalide with a diamine.

Examples of the hydroxyl group-containing compound used in the method [ I ] include: alcohols such as methanol, ethanol, propanol, etc.; phenols such as phenol and cresol. Examples of the halide include: methyl bromide, ethyl bromide, octadecyl bromide, methyl chloride, octadecyl chloride, 1,1, 1-trifluoro-2-iodoethane, etc., and the epoxy group-containing compound may be, for example, propylene oxide, etc. The tetracarboxylic acid diester used in the method [ II ] can be obtained by, for example, ring-opening the tetracarboxylic acid dianhydride exemplified in the synthesis of the polyamic acid using the alcohol. The tetracarboxylic acid diester dihalide used in the process [ III ] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. The diamine used in the methods [ II ] and [ III ] may be any of the specific diamines and other diamines exemplified in the synthesis of the polyamic acid, and preferably includes the specific diamine. The polyamic acid ester may have only the amic acid ester structure or may be a partially esterified product in which the amic acid structure and the amic acid ester structure coexist.

< solution viscosity and weight-average molecular weight >

The polyamic acid, polyimide, and polyamic acid ester obtained in the above manner are preferably compounds having a solution viscosity of 10 to 800 mPas, more preferably 15 to 500 mPas, when prepared into a solution having a concentration of 10% by weight. The solution viscosity (mPa · s) of the polymer is a value measured at 25 ℃ using an E-type rotational viscometer for a 10 wt% polymer solution prepared using a good solvent for the polymer (e.g., γ -butyrolactone, N-methyl-2-pyrrolidone, etc.).

The reduced viscosity is not particularly limited as long as it is within a range in which a uniform coating film can be formed, but is preferably 0.05dl/g to 3.0dl/g, more preferably 0.1dl/g to 2.5dl/g, and particularly preferably 0.3dl/g to 1.5 dl/g.

The polyamic acid, polyimide, and polyamic acid ester contained in the composition such as a liquid crystal alignment agent of the present invention preferably have a weight average molecular weight in terms of polystyrene measured by Gel Permeation Chromatography (GPC) of 500 to 100,000, more preferably 1,000 to 50,000.

Solvents

The composition and the liquid crystal aligning agent of the present invention contain, as a solvent component, a specific solvent (B) which is at least one selected from the group consisting of the compound represented by the formula (B-1A), the compound represented by the formula (B-1B), the compound represented by the formula (B1), and the compound represented by the formula (B2). By containing such a specific solvent (B) in a composition such as a liquid crystal aligning agent, the coating property of the liquid crystal aligning agent or the like on a substrate can be improved.

< 1 > the compound represented by the formula (b-1A)

When the compound represented by the formula (b-1A) is contained in a composition such as a liquid crystal aligning agent, the coating property of the liquid crystal aligning agent to a substrate and the storage stability of the liquid crystal aligning agent can be improved. In addition, good display quality can be ensured even when the liquid crystal display element is narrowed in edge.

For the compound represented by the formula (b-1A), X, Y is each independently-COO-or-OCO-. A. C¹Each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. B is a C1-12 divalent hydrocarbon group, preferably a C1-6 alkylene group.

Examples of the compound represented by the formula (b-1A) include those shown below. Further, the compound represented by the formula (b-1A) may be used singly or in combination of two or more.

[ solution 10]

[ solution 11]

[ solution 12]

Here, for example, the liquid crystal alignment agent is generally stored in a very low temperature environment (for example, -15 ℃) in order to prevent deterioration of polyamic acid or polyimide during the period from production to shipment. However, in some cases, precipitates are generated in the liquid crystal aligning agent after storage for a long time at a low temperature. Further, the precipitate precipitated once is difficult to redissolve, and there is a possibility that a trouble such as a printing failure may occur in the process of manufacturing the liquid crystal display element. The reason why such precipitates are generated is not clear, but it is presumed that one of the reasons is butyl cellosolve which is generally used as a solvent component of a liquid crystal aligning agent. Therefore, as a solvent for improving the coatability to the substrate, it is required to find a new organic solvent instead of butyl cellosolve.

A liquid crystal display is manufactured by disposing a pair of substrates on which liquid crystal alignment films are formed in an opposed manner, and disposing liquid crystal between the pair of substrates disposed in the opposed manner. At this time, the pair of substrates are bonded using a sealant such as an epoxy resin. In a touch panel type display panel represented by a smart phone or a tablet Personal Computer (PC), an attempt to achieve a narrow margin has been made in order to achieve both a further increase in the movable area of the touch panel and a reduction in size of a liquid crystal panel (element). As the liquid crystal panel is narrowed, display unevenness may be seen around the sealant, and this is not satisfactory from the viewpoint of display quality. In order to realize high definition and long life of a liquid crystal display, a liquid crystal display element in which display unevenness (high bezel mura resistance) around the sealant is not easily visible is required.

In this regard, the compound represented by the formula (b-1A) is useful as a new organic solvent in place of butyl cellosolve. Specifically, the liquid crystal aligning agent containing the compound represented by the formula (b-1A) as a solvent component is excellent in storage stability against long-term low-temperature storage and coatability to a substrate, and is suitable for narrowing the margin.

< 2 > the compound represented by the formula (B-1B)

When the compound represented by the formula (B-1B) is contained in a composition such as a liquid crystal aligning agent, the coating property of the liquid crystal aligning agent or the like to a substrate and the storage stability of the liquid crystal aligning agent or the like can be improved. In addition, good display quality can be ensured even when the liquid crystal display element is narrowed in edge.

For the compound represented by the formula (B-1B), R¹～R²Each independently is an alkyl group having 3 to 6 carbon atoms, preferably an alkyl group having 4 to 6 carbon atoms. R³Each independently is a hydrogen atom or a methyl group. n4 is 2 or 3.

When n4 is 2, two R's are preferable³All are hydrogen atoms, or one is a hydrogen atom and the other is a methyl group, and all are particularly preferred.

When n4 is 3, preferably three R³Both hydrogen atoms or two hydrogen atoms and one methyl group, particularly preferably both hydrogen atoms.

Examples of the compound represented by the formula (B-1B) include those shown below. Further, the compound represented by the formula (B-1B) may be used singly or in combination of two or more.

[ solution 13]

[ solution 14]

The compound represented by the formula (B-1B) is useful as a novel organic solvent in place of butyl cellosolve, as in the case of the formula (B-1A). Specifically, the liquid crystal aligning agent containing the compound represented by the formula (B-1B) as a solvent component is excellent in storage stability against long-term low-temperature storage and coatability to a substrate, and is suitable for narrowing the margin.

< 3 > the compound represented by the formula (b1) or the formula (b2)

The compound represented by the formula (b1) or (b2) has good solubility in polyamic acid or polyimide and a moderately high boiling point. Therefore, when a composition such as a liquid crystal aligning agent is printed on a substrate by using such a compound as at least a part of a solvent, volatilization of the solvent from a printer can be suppressed, and a polymer component is less likely to be deposited on the printer. As a result, the printability (particularly long-term printability) can be improved. Further, since the boiling point of the solvent is not excessively high, the amount of the solvent remaining in the coating film after the preheating can be reduced in the case of performing the preheating (prebaking) after the printing. Accordingly, adhesion of dust to the surface of the coating film after preheating can be suppressed, and thus reduction in product yield can be suppressed.

(Compound represented by the formula (b 1))

In the compound represented by the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 or 2 carbon atoms. n is an integer of 0 to 2, preferably 1 or 2.

Examples of the compound represented by the formula (b1) include those shown below. Further, the compound represented by the formula (b1) may be used singly or in combination of two or more.

[ solution 15]

(Compound represented by the formula (b 2))

In the compound represented by the formula (b2), m is an integer of 0 to 2, preferably 1 or 2.

Examples of the compound represented by the formula (b2) include those shown below. Further, the compound represented by the formula (b2) may be used singly or in combination of two or more.

[ solution 16]

The specific solvent (B) contained in the composition or the liquid crystal aligning agent of the present invention may be only one of the compound represented by the formula (B-1A), the compound represented by the formula (B-1B), and the compound represented by the formula (B1) or the formula (B2). Two or more of these compounds may be contained in combination.

(other solvents)

The composition of the present invention such as a liquid crystal aligning agent preferably further contains a solvent other than the specific solvent (B) as a solvent component. Examples of such other solvents include: a solvent which can dissolve the polymer (A) (hereinafter also referred to as "1 st solvent"), an organic solvent which is a poor solvent for the polymer (A) and is other than the specific solvent (B), and the like.

The 1 st solvent may be a good solvent for the polymer (a), and preferable specific examples thereof include: n-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-pentyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropionamide, N, 2-trimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, γ -butyrolactone, γ -butyrolactam, N-dimethylformamide, N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphoric triamide, m-cresol and the like. In addition, the solvent 1 may be used singly or in combination of two or more.

Examples of the poor solvent for the polymer (a) and the organic solvent other than the specific solvent (B) (hereinafter also referred to as "other poor solvent") include: ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, ethylene carbonate, propylene carbonate, diacetone alcohol, diethylene glycol diethyl ether, diisoamyl ether, propylene glycol diacetate, and the like. The organic solvent may be used alone or in combination of two or more. Hereinafter, the group consisting of the other poor solvent and the specific solvent (B) is also referred to as "solvent 2".

The content ratio of the specific solvent (B) in the liquid crystal aligning agent is preferably 1 to 70% by weight relative to the total amount of the solvents contained in the liquid crystal aligning agent. When the content of the specific solvent (B) is less than 1% by weight, the effect of improving the coating property on the substrate is difficult to obtain, and when it exceeds 70% by weight, the polymer component is likely to precipitate. The content ratio of the specific solvent (B) is more preferably 5 to 70% by weight, and particularly preferably 10 to 65% by weight.

From the viewpoint of suppressing the deposition of the polymer (a), the content ratio of the 1 st solvent is preferably 5% by weight or more, more preferably 10% by weight or more, and particularly preferably 15% by weight or more, relative to the total amount of the solvents contained in the liquid crystal aligning agent. In addition, from the viewpoint of suitably obtaining the effect by adding the specific solvent (B), the upper limit value of the content ratio of the 1 st solvent with respect to the total amount of the solvents contained in the liquid crystal aligning agent is preferably 99% by weight or less, more preferably 95% by weight or less, and particularly preferably 85% by weight or less.

The content ratio of the other poor solvent is preferably 70% by weight or less, more preferably 60% by weight or less, particularly preferably 50% by weight or less, and particularly preferably 30% by weight or less, relative to the total amount of the solvent contained in the liquid crystal aligning agent.

From the viewpoint of improving the coatability to the substrate, the ratio of the 1 st solvent to the 2 nd solvent is preferably 0.03 times (by weight) or more, and more preferably 0.05 times (by weight) or more, the amount of the 2 nd solvent used relative to the amount of the 1 st solvent used. From the viewpoint of suppressing the precipitation of the polymer, the amount is preferably 2.5 times (by weight) or less, and more preferably 2.0 times (by weight) or less.

The liquid crystal aligning agent of the present invention preferably contains substantially no butyl cellosolve as a solvent. In the present specification, the phrase "substantially not containing butyl cellosolve" means that the content of butyl cellosolve is preferably 5 wt% or less, more preferably 3 wt% or less, and particularly preferably 0.5 wt% or less, relative to the total amount of the solvent contained in the liquid crystal aligning agent.

Other ingredients

The composition such as a liquid crystal aligning agent of the present invention contains the polymer (a) and the solvent as described above, but may contain other components as needed. Examples of the other components include: polymers other than the polymer (a), compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compounds"), functional silane compounds, the amine compounds (C), and the like.

[ other Polymer ]

The other polymer can be used to improve solution characteristics or electrical characteristics. Examples of such other polymers include: polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like. When the other polymer is added to the liquid crystal aligning agent, the blending ratio of the other polymer is preferably 50% by weight or less, more preferably 0.1% by weight to 40% by weight, and particularly preferably 0.1% by weight to 30% by weight, based on the total amount of the polymer components in the liquid crystal aligning agent.

[ epoxy group-containing Compound ]

The epoxy group-containing compound can be used to improve the adhesion between the liquid crystal alignment film and the substrate surface. Examples of the epoxy group-containing compound include: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2-dibromoneopentyl glycol 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-diglycidylcenzylamine, N, N-diglycidylaminomethylcyclohexane, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, 1, 3-diglycidyl ether, 2-dibromoneopentyl glycol diglycidyl ether, N, N', N '-tetraglycidyl-4, 4' -diaminodiphenylmethane, N, N-diglycidylcarbinylamines, N, N-diglycidylaminome, N, N-diglycidyl-cyclohexylamine, and the like.

When these epoxy-containing compounds are added to the liquid crystal aligning agent, the blending ratio of the epoxy-containing compounds is preferably 40 parts by weight or less, and more preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the total of the polymers contained in the liquid crystal aligning agent.

[ functional silane Compound ]

The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1, 4, 7-triazacyclodecane, 9-trimethoxysilyl-3, 6-diaza-nonyl acetate, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltrimethoxysilane, N-triethoxysilylpropyltriethoxysilane, N-trimethoxysilyl-1, 4, 7-triazacyclodecane, N-trimethoxysilyl-3, 6-diaza-nonyl-acetate, N-hydroxybutanes, N-, Methyl 9-trimethoxysilyl-3, 6-diazananonanoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and the like.

When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio of the functional silane compounds is preferably 2 parts by weight or less, and more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total polymer.

[ amine Compound (C) ]

The amine compound (C) is a compound having a structure in which 1 primary amino group and a nitrogen-containing aromatic heterocycle are bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group. The amine compound (C) can be used for the purpose of improving the electrical characteristics (for example, voltage holding ratio, residual charge relaxation rate, and the like) of a liquid crystal display device in the application of a liquid crystal alignment film.

The nitrogen-containing aromatic heterocycle in the amine compound (C) may be an aromatic ring having a ring skeleton containing one or more nitrogen atoms. Accordingly, the ring skeleton may contain only a nitrogen atom as a hetero atom, or may contain a nitrogen atom and a hetero atom (an oxygen atom, a sulfur atom, or the like) other than a nitrogen atom. Specific examples of the nitrogen-containing aromatic heterocycle include: pyrrole rings, imidazole rings, pyrazole rings, triazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, indole rings, benzimidazole rings, purine rings, quinoline rings, isoquinoline rings, naphthyridine rings, quinoxaline rings, phthalazine rings, triazine rings, azepine rings, diazepine rings, acridine rings, phenazine rings, phenanthroline rings, oxazole rings, thiazole rings, carbazole rings, thiadiazole rings, benzothiazole rings, phenothiazine rings, oxadiazole rings, and the like. The nitrogen-containing aromatic heterocycle may have a substituent introduced to a carbon atom constituting the above-mentioned exemplary ring. Examples of such substituents include: halogen atom, alkyl group, alkoxy group, etc.

The chain hydrocarbon group in the amine compound (C) is preferably a C1-20 group, more preferably a C1-15 group, and particularly preferably a C1-10 group. The chain hydrocarbon group may be linear or branched, and may be saturated or unsaturated. The alicyclic hydrocarbon group is preferably a C3-20 group, more preferably a C3-15 group, and particularly preferably a C3-10 group.

As the amine compound (C), a compound represented by the following formula (C-1) can be preferably used.

[ solution 17]

H₂N-A¹-A² (c-1)

(in the formula (c-1), A¹Is a divalent organic group having a chain hydrocarbon group or an alicyclic hydrocarbon group, A²Is a nitrogen-containing aromatic heterocycle; wherein the primary amino group in the formula is bonded to A¹chain hydrocarbon group or ester ofRing type hydrocarbyl)

In the formula (c-1), A¹Examples of the divalent organic group in (1) include: divalent chain hydrocarbon group, divalent alicyclic hydrocarbon group, -O-R²¹-、-CO-R²¹- (wherein, R)²¹A divalent chain hydrocarbon group or alicyclic hydrocarbon group). The divalent organic group may have-O-, -NH-, -CO-O-, -CO-NH-, -CO-, -S-, -S (O) between carbon-carbon bonds of the divalent chain hydrocarbon group or the divalent alicyclic hydrocarbon group₂-、-Si(CH₃)₂-、-O-Si(CH₃)₂-、-O-Si(CH₃)₂A divalent group such as an aromatic hydrocarbon group such as O-or phenylene, or a heterocyclic group such as pyridylene; a divalent group obtained by substituting at least one hydrogen atom in a divalent chain hydrocarbon group or a divalent alicyclic hydrocarbon group with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an aromatic hydrocarbon group such as a phenyl group, a hydroxyl group, a halogenated alkyl group, or the like. A. the¹As specific examples of the divalent chain hydrocarbon group and alicyclic hydrocarbon group in (1), R in the above-mentioned formula (m-1) can be applied²⁴And (4) description.

A¹The divalent organic group having a chain hydrocarbon group is preferable, and a divalent chain hydrocarbon group is more preferable. A. the¹Preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. A. the²the nitrogen-containing aromatic heterocyclic ring of (2) can be applied to the description.

Specific examples of the amine compound (C) include compounds represented by the following formulae (C-1-1) to (C-1-32). Further, the amine compound (C) may be used singly or in combination of two or more of these compounds.

[ solution 18]

[ solution 19]

In the case where the amine compound (C) is added to the liquid crystal aligning agent, the blending ratio of the amine compound (C) is preferably 1 part by weight or more, more preferably 2 parts by weight or more, relative to 100 parts by weight of the total polymer, from the viewpoint of suitably obtaining the effect by the addition of the amine compound (C). From the viewpoint of not impairing the stability of the liquid crystal aligning agent, the blending ratio of the amine compound (C) is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, relative to 100 parts by weight of the total polymer.

In addition, other additives contained in the liquid crystal aligning agent include, in addition to the above, compounds having at least one oxetanyl group in the molecule, antioxidants, and the like. The proportion of these additives to be used may be appropriately selected depending on the additives to be used within a range not impairing the effect of the present invention.

in the case where the amine compound (C) is contained as an additive in the liquid crystal aligning agent of the present invention, it is preferable that at least a part of the polymer (a) has a carboxyl group from the viewpoint of suitably improving the electrical characteristics of the liquid crystal display element. The number of carboxyl groups in the polymer (a) is preferably 0.1 to 3, more preferably 0.3 to 2, and particularly preferably 0.5 to 1.8 on average relative to the repeating unit of the polymer (a).

The method for adjusting the number of carboxyl groups of the polymer (a) is not particularly limited, and examples thereof include: (i) a method of adjusting the imidization ratio of polyimide, (ii) a method of adjusting the carboxyl group content of diamine used for synthesizing the polymer (a), and the like. Further, the above (i) and (ii) may be used in combination. From the viewpoint of enhancing the degree of freedom of the imidization rate of the polymer (a), the method (ii) is preferably used.

When the polymer (a) having a carboxyl group and the amine compound (C) are contained in the liquid crystal aligning agent, the blending ratio of the amine compound (C) is preferably 0.01 to 2 moles, more preferably 0.05 to 1 mole, and particularly preferably 0.08 to 0.8 mole, based on 1 mole of the carboxyl group of the polymer (a).

The solid content concentration of the liquid crystal aligning agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like, and is preferably in the range of 1 to 10 wt%. That is, the liquid crystal aligning agent of the present invention is applied to the surface of a substrate, preferably heated, as described below, to form a coating film as a liquid crystal alignment film or a coating film to be a liquid crystal alignment film, but in this case, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases to deteriorate the coating properties.

The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5 wt%. In the case of using the offset printing method, it is particularly preferable to set the solution viscosity to a range of 12mPa · s to 50mPa · s by setting the solid content concentration to a range of 3 wt% to 9 wt%. In the case of using the ink jet method, it is particularly preferable to set the solution viscosity to a range of 3 to 20mPa · s by setting the solid content concentration to a range of 1 to 8 wt%. The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 10 to 50 ℃, more preferably 20 to 30 ℃.

Liquid crystal alignment film and liquid crystal display element

The liquid crystal alignment film of the present invention is formed using the liquid crystal aligning agent prepared in the above-described manner. The liquid crystal display element of the present invention further includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The driving mode to which the liquid crystal display element is applied is not particularly limited, and the liquid crystal display element can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, Multi-domain Vertical Alignment (MVA) type, and the like. Hereinafter, a method for manufacturing a liquid crystal display element of the present invention will be described, and a method for manufacturing a liquid crystal alignment film will be described in this description.

The liquid crystal display element of the present invention can be manufactured by the following steps (1) to (3), for example. The step (1) uses different substrates according to the required driving mode. The step (2) and the step (3) are common to the respective drive modes.

[ step (1): formation of coating film ]

First, the liquid crystal aligning agent of the present invention is applied to a substrate, and then the coated surface is heated, thereby forming a coating film on the substrate.

(1-1) in the case of manufacturing a TN, STN, or VA type liquid crystal display device, a pair of 2 substrates provided with a patterned transparent conductive film is coated with the liquid crystal aligning agent of the present invention on each transparent conductive film-formed surface of the substrates, preferably by an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method. Here, the substrate can be, for example: float glass, soda glass, and the like; transparent substrates comprising plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). The transparent conductive film provided on one surface of the substrate may contain 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 order to obtain a patterned transparent conductive film, for example, it is possible to use: a method of forming a transparent conductive film without a pattern and then forming a pattern by photolithography; a method of forming a transparent conductive film using a mask having a desired pattern. In the case of applying the liquid crystal aligning agent, the surface of the substrate on which the coating film is to be formed may be subjected to a pretreatment of previously applying a functional silane compound, a functional titanium compound, or the like, in order to improve the adhesion between the substrate surface and the transparent conductive film and the coating film.

After the liquid crystal alignment agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing sagging of the applied alignment agent and the like. The prebaking temperature is preferably from 30 ℃ to 200 ℃, more preferably from 40 ℃ to 150 ℃, and particularly preferably from 40 ℃ to 100 ℃. The prebaking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a calcination (post-baking) step is carried out for the purpose of completely removing the solvent, and if necessary, thermally imidizing the amic acid structure present in the polymer. The calcination (postbaking) temperature is preferably from 80 ℃ to 300 ℃, more preferably from 120 ℃ to 250 ℃. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film formed in the above manner is preferably 0.001 to 1 μm, and more preferably 0.005 to 0.5. mu.m.

(1-2) in the case of producing an IPS type or FFS type liquid crystal display element, the liquid crystal aligning agent of the present invention is applied to the electrode-forming surface of a substrate provided with an electrode comprising a transparent conductive film or a metal film patterned into a comb-tooth shape and the surface of a counter substrate not provided with an electrode, and then the respective applied surfaces are heated to form a coating film. The materials of the substrate and the transparent conductive film used in this case, the coating method, the heating conditions after coating, the method for patterning the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the formed coating film are the same as those in the above-mentioned (1-1). As the metal film, a film containing a metal such as chromium can be used.

In both cases (1-1) and (1-2), a liquid crystal alignment agent is applied to a substrate, and then an organic solvent is removed to form a coating film as an alignment film. In this case, when the polymer contained in the liquid crystal aligning agent is polyamic acid or an imidized polymer having an imide ring structure and an amic acid structure, a more imidized coating film may be formed by further heating to perform a dehydration ring-closing reaction after the formation of the coating film.

[ step (2): orientation ability imparting treatment

In the case of producing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the step (1) is subjected to a treatment for imparting liquid crystal aligning ability. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. The treatment may be, for example: rubbing the coating film in a fixed direction by a roller around which a cloth containing fibers such as nylon, rayon, and cotton is wound; and photo-alignment treatment in which the coating film is irradiated with polarized or unpolarized radiation. On the other hand, in the case of producing a VA-type liquid crystal display element, the coating film formed in the step (1) may be used as it is as a liquid crystal alignment film, or the coating film may be subjected to an alignment ability imparting treatment.

In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150nm to 800nm can be used as the radiation irradiated to the coating film. 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 thereof. When unpolarized radiation is irradiated, the irradiation direction is set to be an oblique direction.

The light sources used may be, for example: low pressure mercury lamps, high pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, and the like. Ultraviolet rays in a preferred wavelength range can be obtained by a method of using a light source in combination with, for example, a filter, a diffraction grating, or the like. The irradiation dose of the radiation is preferably 100J/m²～50,000J/m²More preferably 300J/m²～20,000J/m². In addition, in order to improve the reactivity, the coating film may be irradiated with light while being heated. The temperature at the time of heating is usually from 30 ℃ to 250 ℃, preferably from 40 ℃ to 200 ℃, and more preferably from 50 ℃ to 150 ℃.

The liquid crystal alignment film after the rubbing treatment was further subjected to the following treatments: a process of changing a pretilt angle of a partial region of the liquid crystal alignment film by irradiating ultraviolet rays to the partial region; a process of forming a resist film on a part of the surface of the liquid crystal alignment film, rubbing the resist film in a direction different from the rubbing process, and removing the resist film; thereby allowing the liquid crystal alignment film to have different liquid crystal alignment ability in each region. In this case, the viewing characteristics of the resulting liquid crystal display element can be improved. A liquid crystal alignment film suitable for a VA-type liquid crystal display element can also be suitably used for a Polymer Stabilized Alignment (PSA) type liquid crystal display element.

[ step (3): construction of liquid Crystal cell

A liquid crystal cell was manufactured by preparing 2 substrates on which liquid crystal alignment films were formed as described above and disposing liquid crystal between the 2 substrates disposed in opposition to each other. For example, the following two methods can be used to manufacture a liquid crystal cell.

The first method is a previously known method. First, 2 substrates were placed in opposition to each other with a gap (cell gap) therebetween so that the liquid crystal alignment films were opposed to each other, the peripheral portions of the 2 substrates were bonded to each other with a sealant, a liquid crystal was injected and filled into the cell gap defined by the substrate surfaces and the sealant, and then the injection hole was sealed, thereby producing a liquid crystal cell. The second method is a method called a One Drop Fill (ODF) method. For example, a sealant curable by ultraviolet light is applied to a predetermined portion of one of 2 substrates on which a liquid crystal alignment film is formed, liquid crystal is dropped onto a predetermined plurality of portions on a liquid crystal alignment film surface, the other substrate is attached so that the liquid crystal alignment film faces the other substrate, the liquid crystal is spread over the entire surface of the substrate, and then ultraviolet light is irradiated onto the entire surface of the substrate to cure the sealant, thereby manufacturing a liquid crystal cell. In either method, it is preferable that the liquid crystal cell manufactured as described above is further heated to a temperature at which the liquid crystal used is in an isotropic phase, and then gradually cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal.

For example, an epoxy resin containing a hardener and alumina balls as spacers can be used as the sealant.

Examples of the liquid crystal include nematic liquid crystal (nematic liquid crystal) and smectic liquid crystal (nematic liquid crystal), and among them, nematic liquid crystal is preferable, and for example: schiff base (Schiff base) liquid crystals, azoxy (azoxy) liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl (terphenyl) liquid crystals, diphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane (cubane) liquid crystals, and the like. In addition, the following substances may be added to these liquid crystals: cholesteric liquid crystals (cholesteric liquid crystals) such as cholesteryl chloride, cholesteryl nonanoate, cholesteryl carbonate, etc.; chiral agents sold under the trade names "C-15", "CB-15" (manufactured by Merck); ferroelectric liquid crystals (ferroelectric liquid crystals) such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate (p-decyloxybenzylidene-p-amino-2-methylbutylchinnamate) and the like.

Then, a polarizing plate is bonded to the outer surface of the liquid crystal cell, whereby a liquid crystal display element can be obtained. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include: a polarizing plate formed by sandwiching a polarizing film called "H film" which absorbs iodine while stretching and orienting polyvinyl alcohol, or a polarizing plate including the H film itself, with a cellulose acetate protective film. In the case of rubbing the coating films, 2 substrates are disposed so that the rubbing directions of the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel to each other.

the liquid crystal display element of the present invention can be effectively applied to various devices, for example, to: a display device such as a clock, a portable game machine, a word processor (word processor), a notebook personal computer (note type personal computer), a car navigation system (car navigation system), a camcorder (camrecorder), a Personal Digital Assistant (PDA), a digital camera (digital camera), a mobile phone, a smart phone, various monitors, and a liquid crystal television.

The present invention will be further specifically described below with reference to examples, but the present invention is not limited to these examples.

In the following examples, the imidization ratio of polyimide in the polymer solution and the solution viscosity of the polymer solution were measured by the following methods.

[ imidization ratio of polyimide ]

Putting the solution of polyimide into pure water, and adding the solutionThe obtained precipitate was dried under reduced pressure at room temperature, dissolved in deuterated dimethyl sulfoxide, and measured at room temperature using tetramethylsilane as a reference substance¹H-nuclear magnetic resonance (¹H-Nuclear magnetic resonance，¹H-NMR). According to what is obtained¹H-NMR spectrum, the imidization rate [% ] was determined by the following numerical formula (x)]。

Imidization rate [% ]]＝(1-A¹/A²×α)×100(x)

(in the formula (x), A¹Is the peak area of a proton derived from an NH group, A, occurring in the vicinity of a chemical shift of 10ppm²Is the peak area derived from other protons, and α is the number ratio of the other protons to 1 proton of the NH group in the precursor (polyamic acid) of the polymer. )

[ solution viscosity of Polymer solution ]

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

[ example 1]

[ example 1A ]

a50 ml four-necked flask equipped with a stirrer and a nitrogen inlet was charged with 0.60g (2.0mmol) of 1,3-bis (4-aminophenylethyl) urea (1,3-bis (4-aminophenylethyl) urea, BAPU) as a diamine and 1.95g (18.0mmol) of p-phenylenediamine (p-PDA), and 30g of N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP) was added thereto and dissolved by stirring while feeding nitrogen. While stirring the diamine solution, 3.70g (18.9mmol) of 1,2,3,4-cyclobutanetetracarboxylic Dianhydride (CBDA) as tetracarboxylic Dianhydride was added, and further NMP was added so that the solid content concentration became 12 wt%, and the mixture was stirred at room temperature for 4 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (PA-1).

To this polyamic acid solution were added NMP and a compound represented by the following formula (B-a) (hereinafter referred to as "compound (B-a)") as a specific solvent (B), and the solvent composition was NMP: compound (b-a) ═ 60: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% to prepare a liquid crystal aligning agent (S1A).

[ solution 20]

[ example 2A ]

19.2g (0.098mol) of CBDA as tetracarboxylic dianhydride and 24.2g (0.1mol) of 1, 5-bis (4-aminophenoxy) pentane as diamine were dissolved in 343.5g of NMP, and the reaction was carried out at room temperature for 10 hours. The polymerization reaction proceeds easily and uniformly, thereby obtaining polyamic acid (PA-2). NMP and a compound represented by the following formula (B-B) (hereinafter referred to as "compound (B-B)") as a specific solvent (B) are added to an NMP solution of the polyamic acid (PA-2) so that the solvent composition becomes NMP: compound (b-b) ═ 50: the liquid crystal aligning agent was prepared in such a manner that the concentration of polyamic acid was 50 (weight ratio) and 6.0 wt% (S2A).

[ solution 21]

[ example 3A ]

22.42g (0.1mol) of 2,3, 5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride and 18.73g (0.094mol) of 4,4' -diaminodiphenylamine (4,4' -diaminodiphenylamine, 4,4' -DADPA) as diamine were mixed in 345.1g of NMP, and reacted at room temperature for 5 hours. The polymerization reaction proceeds easily and uniformly, thereby obtaining polyamic acid (PA-3). NMP and a compound represented by the following formula (B-c) (hereinafter referred to as "compound (B-c)") as a specific solvent (B) are added to an NMP solution of the polyamic acid (PA-3) so that the solvent composition becomes NMP: compound (b-c) ═ 80: 20 (weight ratio) and the polyamic acid concentration was 6.0 wt% to prepare a liquid crystal alignment agent (S3A).

[ solution 22]

[ example 4A ]

6.5g (0.06mol) of p-PDA and 15.22g (0.04mol) of 4- (4- (trans-n-heptylcyclohexyl) phenoxy) -1, 3-diaminobenzene (PCH7DAB, the compound represented by the formula (d-4-3)) as diamines were dissolved in 165g of NMP, 19.41g (0.099mol) of CBDA as a tetracarboxylic dianhydride was added thereto, and a reaction was carried out at room temperature for 24 hours to obtain a solution containing polyamic acid (PA-4). The weight-average molecular weight (Mw) of the obtained polyamic acid (PA-4) was 40,000. To 30g of this solution were added NMP and a compound represented by the following formula (B-d) (hereinafter referred to as "compound (B-d)") as a specific solvent (B) to prepare a solution having a solvent composition of NMP: compound (b-d) ═ 80: 20 (weight ratio) and the polyamic acid concentration was 4.5 wt% (S4A).

[ solution 23]

[ example 5A ]

1.46g (13.5mmol) of p-PDA as a diamine and 0.78g (1.50mmol) of cholesteryl 3, 5-diaminobenzoate were mixed with 20.0g of NMP, 2.85g (14.5mmol) of CBDA as a tetracarboxylic dianhydride and 24.7g of NMP were added, and a reaction was carried out at 25 ℃ for 5 hours to obtain a solution containing polyamic acid (PA-5). Then, NMP and a compound represented by the following formula (B-e) (hereinafter referred to as "compound (B-e)") as a specific solvent (B) were added to 40.0g of the obtained polyamic acid solution so that the solvent composition became NMP: compound (b-e) ═ 75: 25 (weight ratio) and the polyamic acid concentration was 4.0 wt% to prepare a liquid crystal alignment agent (S5A).

[ solution 24]

[ example 6A ]

CBDA (2.58 g, 13.1mmol) as tetracarboxylic dianhydride and PCH7DAB (5.0 g, 13.1mmol) as diamine were dissolved in NMP (43 g), and the reaction mixture was stirred at 20 ℃ for 4 hours to obtain a solution containing polyamic acid (PA-6). Then, NMP and a compound represented by the following formula (B-f) (hereinafter referred to as "compound (B-f)") as a specific solvent (B) were added to the NMP solution of the obtained polyamic acid (PA-6) so that the solvent composition became NMP: compound (b-f) ═ 35: 65 (weight ratio) and the solid content concentration was 3.0 wt% to prepare a liquid crystal aligning agent (S6A).

[ solution 25]

[ example 7A ]

8.724g (0.04mol) of pyromellitic dianhydride (PMDA) as a tetracarboxylic dianhydride, 2.877g (0.0266mol) of p-PDA as a diamine, and 4.567g (0.012mol) of PCH7DAB as a diamine were reacted at room temperature for 3 hours in NMP91.6g to prepare a solution containing polyamic acid (PA-7). To 25g of the polyamic acid solution, NMP and a compound represented by the following formula (B-g) (hereinafter referred to as "compound (B-g)") as a specific solvent (B) were added so that the solvent composition became NMP: compound (b-g) ═ 60: 40 (weight ratio) and a solid content concentration of 5.0 wt% were prepared as a liquid crystal aligning agent (S7A).

[ solution 26]

[ example 8A ]

A solution containing polyamic acid intermediate (PA-8) was prepared by reacting 14.64g (0.072mol) of 2, 4-diamino-N, N-diallylaniline as a diamine, 2.96g (0.016mol) of N-dodecylamine as a monoamine, and 15.69g (0.08mol) of CBDA as a tetracarboxylic dianhydride in 300g of NMP at room temperature for 4 hours. NMP and a compound represented by the following formula (B-h) (hereinafter referred to as "compound (B-h)") as a specific solvent (B) were added to an NMP solution of the polyamic acid intermediate to prepare a solution having a solvent composition of NMP: compound (b-h) ═ 60: 40 (weight ratio) and a solid content concentration of 6.0 wt% (S8A).

[ solution 27]

[ example 9A ]

Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6: 8-bisanhydride, BODA)4.50g (0.018mol), PCH7DAB 0.68g (0.0018mol) as diamine, and p-PDA 1.75g (0.0162mol) were reacted at room temperature in NMP39.3g, and then reacted at 40 ℃ for 43 hours. To 42g of the polyamic acid solution was added NMP to prepare a 1 wt% solution, and to this solution were added 4.18g of acetic anhydride as an imidization catalyst and 6.48g of pyridine, followed by reaction at room temperature for 30 minutes and reaction at 120 ℃ for 2 hours. This solution was poured into a large amount of methanol, and the obtained white precipitate was filtered and dried to obtain white polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-1)) was measured, and it was 72%. NMP and a compound (B-a) as a specific solvent (B) are added to the powder and dissolved, and the solvent composition is NMP: compound (b-a) ═ 50: 50 (weight ratio) and the solid content concentration was 4.5 wt%, and a liquid crystal aligning agent was prepared (S9A).

Comparative example 1A to comparative example 9A

With respect to the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and a liquid crystal aligning agent was prepared in the same manner as in the above-mentioned example 1A to example 9A except that Butyl Cellosolve (BC) was used as the 2 nd solvent instead of the specific solvent (B), thereby obtaining liquid crystal aligning agents (R1A) to (R9A), respectively. In addition, comparative example XA (X is an integer of 1 to 9) corresponds to example XA. That is, in comparative example XA, the same polymer as in example XA was synthesized, and a liquid crystal aligning agent was prepared in the same manner as in example XA except that butyl cellosolve was used instead of the specific solvent (B).

[ example 10A ]

Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (BODA) as tetracarboxylic dianhydride 4.50g (0.018mol), and the compound represented by the formula (d-4-2) (PBCH5DAB)2.34g (0.0054mol) as diamine and 3,5-diaminobenzoic acid (3,5-diaminobenzoic acid, 35DAB)1.92g (0.0126mol) were reacted with NMP 26.3g at room temperature, and then reacted at 40 ℃ for 43 hours. To 30g of the polyamic acid solution was added NMP to prepare a 6 wt% solution, and 2.4g of acetic anhydride as an imidization catalyst and 1.8g of pyridine were added, followed by reaction at room temperature for 30 minutes and reaction at 110 ℃ for 4 hours. This solution was poured into a large amount of methanol, and the obtained white precipitate was filtered and dried to obtain white polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-2)) was measured, and it was 72%. This powder (0.6 g) was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as a 1 st solvent and a compound (B-a) as a specific solvent (B) to prepare a solution having a polyimide concentration of 6.0 wt%. To the solution, 0.4g (corresponding to 0.03g as 3-AMP) of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) was added, and the mixture was stirred at 50 ℃ for 15 hours, whereby a liquid crystal aligning agent was obtained (S10A). Further, the liquid crystal aligning agent is a compound having a solvent composition of NMP: d1: compound (b-a) ═ 30: 20: 50 (weight ratio).

[ example 11A ]

The same operation as in example 10A was carried out except that the amount of PBCH5DAB used in the synthesis of polyamic acid was changed to 3.90g (0.0090mol) and the amount of 3,5-diaminobenzoic acid was changed to 1.37g (0.0090mol), thereby obtaining a polyamic acid solution. In addition, the same operation as in example 10A was performed using the obtained polyamic acid solution, to obtain polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-3)) was measured, and it was 74%. 0.6g of this powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a 1 st solvent and a compound (B-B) as a specific solvent (B) to prepare a solution having a polyimide concentration of 6.0% by weight. To the solution, 0.8g (corresponding to 0.06g as 3-AMP) of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) was added, and the mixture was stirred at 50 ℃ for 15 hours, whereby a liquid crystal aligning agent was obtained (S11A). Further, the liquid crystal aligning agent is a compound having a solvent composition of NMP: d2: compound (b-b) ═ 30: 30: 40 (weight ratio).

[ example 12A ]

A solution containing polyamic acid (PA-1) was prepared in the same manner as in example 1A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (B-c) as the specific solvent (B), to obtain a solvent composition D1: compound (b-c) ═ 60: 40 (weight ratio) and a solid content concentration of 6.0 wt% (S12A).

[ example 13A ]

A solution containing polyamic acid (PA-2) was prepared in the same manner as in the example 2A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the 1 st solvent and compounds (B-D) as the specific solvent (B), to obtain a solvent composition D2: compound (b-d) ═ 50: 50 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S13A).

[ example 14A ]

A solution containing polyamic acid (PA-3) was prepared in the same manner as in the example 3A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent, and compound (B-e) as the specific solvent (B), to obtain a solution having a solvent composition of NMP: d1: compound (b-e) ═ 40: 40: 20 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S14A).

[ example 15A ]

A solution containing polyamic acid (PA-4) was prepared in the same manner as in the example 4A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder and N, N '-tetraglycidyl-4, 4' -diaminodiphenylmethane (E1) as an additive were dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a 1 st solvent and a compound (B-f) as a specific solvent (B), to obtain a solution having a solvent composition of NMP: d2: compound (b-f) ═ 40: 40: 20 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S15A). The amount of the additive (E1) used was set to 5 parts by weight relative to the polyamic acid powder.

[ example 16A ]

A solution containing polyamic acid (PA-5) was prepared in the same manner as in the example 5A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (B-g) as the specific solvent (B), to obtain a solvent composition D1: compound (b-g) ═ 75: 25 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S16A).

[ example 17A ]

A solution containing polyamic acid (PA-6) was prepared in the same manner as in the example 6A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the 1 st solvent and compounds (B-h) as the specific solvent (B), to obtain a solvent composition D2: compound (b-h) ═ 35: 65 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S17A).

[ example 18A ]

A solution containing polyamic acid (PA-7) was prepared in the same manner as in the example 7A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ -butyrolactone (D3) as the 1 st solvent, and a compound (B-a) as the specific solvent (B), to obtain a solution having a solvent composition of NMP: d3: compound (b-a) ═ 30: 30: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% (S18A).

[ example 19A ]

A solution containing polyamic acid intermediate (PA-8) was prepared in the same manner as in the example 8A. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a 1 st solvent and compound (B-B) as a specific solvent (B) to obtain a solution having a solvent composition of NMP: d2: compound (b-b) ═ 30: 30: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% (S19A).

[ example 20A ]

A powder of polyimide (PI-1) was obtained in the same manner as in the example 9A. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (B-c) as the specific solvent (B), to obtain a solvent composition D1: compound (b-c) ═ 50: 50 (weight ratio) and a solid content concentration of 6.0 wt% (S20A).

< evaluation of storage stability >

Each of the obtained liquid crystal aligning agents was filtered through a 1.0 μm filter, stored at-30 ℃ for 1 month, and then returned to room temperature (25 ℃) to observe the presence or absence of precipitates in the liquid crystal aligning agent. The results are shown in tables 1 and 2 below. In tables 1 and 2, the case where no precipitate was observed in the liquid crystal aligning agent was indicated as "o", and the case where precipitate was observed in the liquid crystal aligning agent was indicated as "x".

< evaluation of printability >

Each of the prepared liquid crystal aligning agents was filtered through a 1.0 μm filter, stored at-15 ℃ for 6 months, and then returned to room temperature (25 ℃). Then, a liquid crystal alignment agent was applied to the transparent electrode surface of the glass substrate having the transparent electrode including the ITO film using a liquid crystal alignment film printer (manufactured by japan portrait printing (jet)). Then, the coating film was heated (pre-baked) on a hot plate at 80 ℃ for 1 minute to remove the solvent, and then heated (post-baked) on a hot plate at 200 ℃ for 10 minutes to form a coating film having an average film thickness of 0.06. mu.m. The coating film was observed with a microscope at a magnification of 20 times to check the presence or absence of uneven printing and pinholes. The evaluation was carried out in the following manner: the case where printing unevenness and pinholes were not substantially observed was evaluated as good printability (o), and the case where at least either of printing unevenness and pinholes was observed was evaluated as poor printability (x). The results are shown in tables 1 and 2 below.

[ Table 1]

[ Table 2]

Note that the abbreviations in table 1 and table 2 are as follows.

(acid dianhydride)

AN-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

AN-2: 2,3, 5-tricarboxylic cyclopentyl acetic dianhydride

AN-3: pyromellitic dianhydride

AN-4: bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride

(diamine)

DA-1: 1, 5-bis (4-aminophenoxy) pentane

DA-2: 2, 4-diamino-N, N-diallylaniline

DA-3: 3,5-diaminobenzoic acid cholestanyl ester

35 DAB: 3,5-diaminobenzoic acid

(monoamine)

MA-1: n-dodecylamine

(1 st solvent)

D1: 3-methoxy-N, N-dimethylpropionamide

D2: 3-butoxy-N, N-dimethylpropionamide

D3: gamma-butyrolactone

(the 2 nd solvent)

BC: butyl cellosolve

(additives)

3-AMP: 3-aminomethylpyridine (compound represented by the formula (c-1-16))

E1: n, N, N ', N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane

< production and evaluation of photo-alignment FFS type liquid Crystal display element >

(1) Manufacture of FFS type liquid crystal display element using optical alignment method

An FFS type liquid crystal display device 10 as shown in fig. 1 was produced. First, a pair of a glass substrate 11a having an electrode pair on one surface thereof, which is formed in order of a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb-tooth shape, and an opposite glass substrate 11b having no electrode is formed, and a coating film is formed by an inkjet coating method using the liquid crystal aligning agent (S1A) obtained above on the surface of the glass substrate 11a having a transparent electrode and the one surface of the opposite glass substrate 11 b. In addition, before the liquid crystal aligning agent (S1A) was applied to the substrate, the solvent composition was set to "NMP: compound (b-a) ═ 60: 40 (weight ratio) ", the liquid crystal alignment agent was prepared so that the viscosity became 18cP, and the viscosity was adjusted to coat the liquid crystal alignment agent on the substrate.

Subsequently, the coating film was prebaked with a hot plate at 80 ℃ for 1 minute, and then heated at 230 ℃ for 15 minutes in an oven with a nitrogen gas substitution in the storage (postbaking), thereby forming a coating film having an average film thickness of 0.1 μm. Fig. 2(a) and 2(b) show schematic plan views of the top electrode 13 used here. Fig. 2(a) is a plan view of the top electrode 13, and fig. 2(b) is an enlarged view of a portion C1 surrounded by a broken line in fig. 2 (a). In this example, a substrate having a top electrode with a line width d1 of 4 μm and an inter-electrode distance d2 of 6 μm was used. The top electrode 13 is a driving electrode using four systems of an electrode a, an electrode B, an electrode C, and an electrode D. Fig. 3 shows a structure of a driving electrode of the liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four systems of drive electrodes, and each region of the four systems of drive electrodes becomes a pixel region.

Then, polarized ultraviolet light 300J/m containing 313nm bright line was irradiated from the substrate normal direction to each surface of the coating films using Hg-Xe lamp and Glan-Taylor prism (Glan-Taylor prism), respectively²Thereby obtaining a pair of substrates having liquid crystal alignment films. In this case, the light irradiation process is performed after setting the polarization plane direction such that the direction of the line segment projecting the polarization plane of the polarized ultraviolet rays onto the substrate is the direction of the double arrow in fig. 2(a) and 2(b) with respect to the substrate normal direction as the irradiation direction of the polarized ultraviolet rays.

Then, an epoxy resin adhesive containing alumina balls having a diameter of 5.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of the 1 substrate by screen printing, and then the liquid crystal alignment films of the pair of substrates were faced to each other, overlapped and pressure-bonded so that the directions of projecting the polarization planes of the polarized ultraviolet rays to the substrates were parallel, and the adhesive was heat-cured at 150 ℃ for 1 hour. Then, a liquid crystal "MLC-6221" manufactured by Merck corporation was filled into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, it was heated to 150 ℃ and slowly cooled to room temperature.

Next, polarizing plates are bonded to both outer sides of the substrate, thereby manufacturing an FFS type liquid crystal display device. At this time, 1 polarizing plate was attached so that the polarization direction thereof was parallel to the direction in which the polarization plane of the polarized ultraviolet ray of the liquid crystal alignment film was irradiated to the substrate surface, and the other polarizing plate was attached so that the polarization direction thereof was perpendicular to the polarization direction of the former polarizing plate.

The above-described method was repeated to manufacture a total of 5 FFS type liquid crystal display devices, and the liquid crystal alignment properties, the voltage holding ratio, the heat resistance, the frame unevenness resistance, and the image sticking characteristics were evaluated one by one. In any case, ultraviolet irradiation under voltage application was not performed.

(2) Evaluation of liquid Crystal alignment Properties

In the FFS type liquid crystal display device manufactured as described above, the presence or absence of an abnormal region of a change in brightness when a voltage of 5V was turned ON/OFF (applied/released) was observed with a microscope at a magnification of 50 times. The evaluation was carried out in the following manner: the case where no abnormal region was observed was defined as "good" liquid crystal alignment, and the case where an abnormal region was observed was defined as "poor" liquid crystal alignment. In this liquid crystal display element, the liquid crystal alignment property is "good".

(3) Evaluation of Voltage holding ratio

In the FFS mode liquid crystal display device manufactured as described above, after a voltage of 5V was applied at 23 ℃ for an application time of 60 microseconds and at intervals (span) of 167 milliseconds, a Voltage Holding Ratio (VHR) after 167 milliseconds from the release of the application was measured, and as a result, the voltage holding ratio was 99.4%. Further, the measurement apparatus was VHR-1 manufactured by Toyang Technica (Strand).

(4) Evaluation of Heat resistance

The voltage holding ratio was measured in the same manner as in the evaluation of the voltage holding ratio in (3), and this value was defined as an initial VHR (VHR)_BF). Then, the liquid crystal display element after the initial VHR measurement was left to stand in an oven at 100 ℃ for 500 hours. Then, after the liquid crystal display element was left to stand at room temperature and left to cool to room temperature, the voltage holding ratio was measured in the same manner as described above, and the value was set to VHR_AF. Further, the rate of change of the voltage holding ratio (Δ VHR (%)) before and after applying thermal stress was determined from the following equation (EX-2).

△VHR(％)＝((VHR_BF-VHR_AF)÷VHR_BF)×100(EX-2)

The evaluation of heat resistance was performed as follows: the heat resistance was evaluated as "good" when the change rate Δ VHR was less than 4%, as "acceptable" when the change rate Δ VHR was 4% or more and less than 5%, and as "poor" when the change rate Δ VHR was 5% or more. As a result, Δ VHR was 2.9%, and the heat resistance of the liquid crystal display element was "good".

(5) Resistance to unevenness of the sealant periphery (resistance to frame unevenness)

The manufactured FFS type liquid crystal display element was stored at 25 ℃ and 50% RH for 30 days, and then was driven at an ac voltage of 5V to observe a lighting state. The evaluation is as follows: if no difference in brightness (more black) or more white (more white) is seen around the sealant, "good" is evaluated if the difference in brightness (more black or more white) is seen around the sealant but the difference in brightness disappears within 5 minutes after lighting, "good" is evaluated if the difference in brightness (more black or more white) is seen around the sealant but the difference in brightness disappears within more than 5 minutes and 20 minutes after lighting, "clear" is evaluated, and "bad" is evaluated if the difference in brightness still disappears after 20 minutes. As a result, in this liquid crystal display element, no luminance difference was observed around the sealant, and the frame unevenness resistance was judged to be "excellent".

(6) Evaluation of residual image characteristics (DC residual image evaluation)

The produced light-oriented FFS type liquid crystal display element was placed at 25 ℃ under an atmosphere of 1 atmosphere. The bottom electrode is set to be a common electrode for all the four systems of drive electrodes, and the potential of the bottom electrode is set to 0V potential (ground potential). The electrode B and the electrode D were brought into a 0V applied state by short-circuiting the common electrode, and a combined voltage including an AC voltage of 3.5V and a DC voltage of 1V was applied to the electrode A and the electrode C for 2 hours. After 2 hours had elapsed, a voltage of 1.5V was applied to all of the electrodes A to D. Then, the time from the time when the application of the voltage having an ac voltage of 1.5V was started to all the drive electrodes until the difference in luminance between the drive stress applied region (the pixel region of the electrode a and the electrode C) and the drive stress non-applied region (the pixel region of the electrode B and the electrode D) was visually undetectable was measured, and this was defined as the residual image erasing time. Further, the shorter the time, the more difficult it is to generate an afterimage. The evaluation was carried out in the following manner: as a result of evaluating "good" when the afterimage erasing time is less than 30 seconds, evaluating "ok" when the afterimage erasing time is 30 seconds or more and less than 120 seconds, and evaluating "bad" when the afterimage erasing time is 120 seconds or more, the liquid crystal display element of the present example evaluated "good" when the afterimage erasing time is 1 second.

From the above results, the liquid crystal aligning agent of the example using the specific solvent (B) was excellent in storage stability during low-temperature storage and also in printability after low-temperature storage. In contrast, the liquid crystal aligning agents of the comparative examples were poor in storage stability and printability after storage at low temperatures. From this, it was found that by using the specific solvent (B), the coating property to the substrate can be secured and the storage stability can be improved.

[ example 2]

[ example 1B ]

0.60g (2.0mmol) of 1,3-bis (4-aminophenylethyl) urea (BAPU) and 1.95g (18.0mmol) of p-phenylenediamine (p-PDA) as diamines were charged into a 50ml four-necked flask equipped with a stirrer and a nitrogen inlet, and 30g of N-methyl-2-pyrrolidone (NMP) was added and dissolved with stirring while feeding nitrogen. While stirring the diamine solution, 3.70g (18.9mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) as tetracarboxylic dianhydride was added, NMP was further added so that the solid content concentration became 12 wt%, and the mixture was stirred at room temperature for 4 hours under a nitrogen atmosphere to obtain a polyamic acid (PA-1) solution.

NMP and a compound (2B-a) represented by the following formula (2B-a) as a specific solvent (B) are added to the polyamic acid solution so that the solvent composition becomes NMP: compound (2b-a) ═ 60: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% to prepare a liquid crystal aligning agent (S1B).

[ solution 28]

[ example 2B ]

19.2g (0.098mol) of CBDA as tetracarboxylic dianhydride and 24.2g (0.1mol) of 1, 5-bis (4-aminophenoxy) pentane as diamine were dissolved in 343.5g of NMP, and the reaction was carried out at room temperature for 10 hours. The polymerization reaction proceeds easily and uniformly, thereby obtaining polyamic acid (PA-2). To the NMP solution of the polyamic acid (PA-2) were added NMP and a compound (2B-a) as a specific solvent (B), and the solvent composition was NMP: compound (2b-a) ═ 50: the liquid crystal aligning agent was prepared in such a manner that the concentration of polyamic acid was 50 (weight ratio) and 6.0 wt% (S2B).

[ example 3B ]

22.42g (0.1mol) of 2,3, 5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride and 18.73g (0.094mol) of 4,4 '-diaminodiphenylamine (4,4' DADPA) as diamine were mixed in 345.1g of NMP and reacted at room temperature for 5 hours. The polymerization reaction proceeds easily and uniformly, thereby obtaining polyamic acid (PA-3). To the NMP solution of the polyamic acid (PA-3) were added NMP and a compound (2B-a) as a specific solvent (B), and the solvent composition was NMP: compound (2b-a) ═ 80: 20 (weight ratio) and the polyamic acid concentration was 6.0 wt% to prepare a liquid crystal alignment agent (S3B).

[ example 4B ]

6.5g (0.06mol) of p-PDA and 15.22g (0.04mol) of 4- (4- (trans-n-heptylcyclohexyl) phenoxy) -1, 3-diaminobenzene (PCH7DAB, the compound represented by the formula (d-4-3)) as diamines were dissolved in 165g of NMP, 19.41g (0.099mol) of CBDA as a tetracarboxylic dianhydride was added thereto, and a reaction was carried out at room temperature for 24 hours to obtain a solution containing polyamic acid (PA-4). The weight-average molecular weight (Mw) of the obtained polyamic acid (PA-4) was 40,000. To 30g of this solution were added NMP, diethylene glycol Diethyl Ether (DEDG), and compound (2B-a) as a specific solvent (B), and a preparation solvent having the composition NMP: DEDG: compound (2b-a) ═ 80: 10: 10 (weight ratio) and the polyamic acid concentration was 4.5 wt% (S4B).

[ example 5B ]

1.46g (13.5mmol) of p-PDA as a diamine and 0.78g (1.50mmol) of cholesteryl 3, 5-diaminobenzoate (DA-3) were mixed with 20.0g of NMP, 2.85g (14.5mmol) of CBDA as a tetracarboxylic dianhydride was added thereto, 24.7g of NMP was added thereto, and a reaction was carried out at 25 ℃ for 5 hours to obtain a solution containing polyamic acid (PA-5). Then, to 40.0g of the obtained polyamic acid solution were added NMP and a compound (2B-a) as a specific solvent (B), and the solvent composition was NMP: compound (2b-a) ═ 75: 25 (weight ratio) and the polyamic acid concentration was 4.0 wt% to prepare a liquid crystal alignment agent (S5B).

[ example 6B ]

CBDA (2.58 g, 13.1mmol) as tetracarboxylic dianhydride and PCH7DAB (5.0 g, 13.1mmol) as diamine were dissolved in NMP (43 g), and the reaction mixture was stirred at 20 ℃ for 4 hours to obtain a solution containing polyamic acid (PA-6). Then, NMP and a compound (2B-a) as a specific solvent (B) were added to an NMP solution of the obtained polyamic acid (PA-6) so that the solvent composition became NMP: compound (2b-a) ═ 35: 65 (weight ratio) and the solid content concentration was 3.0 wt% to prepare a liquid crystal aligning agent (S6B).

[ example 7B ]

A solution containing polyamic acid (PA-7) was prepared by reacting 8.724g (0.04mol) of pyromellitic dianhydride (PMDA) as tetracarboxylic dianhydride, p-PDA2.877g (0.0266mol) as diamine, and PCH7DAB 4.567g (0.012mol) in 91.6g of NMP at room temperature for 3 hours. NMP and a compound represented by the following formula (2B-B) (hereinafter referred to as "compound (2B-B)") as a specific solvent (B) were added to 25g of the polyamic acid solution, and the solvent composition was NMP: compound (2b-b) ═ 60: 40 (weight ratio) and a solid content concentration of 5.0 wt% were prepared as a liquid crystal aligning agent (S7B).

[ solution 29]

[ example 8B ]

A solution containing polyamic acid intermediate (PA-8) was prepared by reacting 14.64g (0.072mol) of 2, 4-diamino-N, N-diallylaniline as a diamine, 2.96g (0.016mol) of N-dodecylamine as a monoamine, and 15.69g (0.08mol) of CBDA as a tetracarboxylic dianhydride in 300g of NMP at room temperature for 4 hours. NMP and a compound (2B-a) as a specific solvent (B) were added to the NMP solution of the polyamic acid intermediate to prepare a solution having a solvent composition of NMP: compound (2b-a) ═ 60: 40 (weight ratio) and a solid content concentration of 6.0 wt% (S8B).

[ example 9B ]

4.50g (0.018mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (BODA) as tetracarboxylic dianhydride, 0.68g (0.0018mol) of PCH7DAB as diamine, and 1.75g (0.0162mol) of p-PDA were reacted with 39.3g of NMP at room temperature, and then reacted at 40 ℃ for 43 hours. To 42g of the polyamic acid solution was added NMP to prepare a 1 wt% solution, and to this solution were added 4.18g of acetic anhydride as an imidization catalyst and 6.48g of pyridine, followed by reaction at room temperature for 30 minutes and reaction at 120 ℃ for 2 hours. This solution was poured into a large amount of methanol, and the obtained white precipitate was filtered and dried to obtain white polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-1)) was measured, and it was 72%. NMP and a compound (2B-a) as a specific solvent (B) were added to the powder and dissolved, and the solvent composition was NMP: compound (2b-a) ═ 50: 50 (weight ratio) and the solid content concentration was 4.5 wt%, and a liquid crystal aligning agent was prepared (S9B).

Comparative example 1B, comparative example 3B to comparative example 9B

With respect to the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and a liquid crystal aligning agent was prepared in the same manner as in example 1B, example 3B to example 9B except that Butyl Cellosolve (BC) was used as the 2 nd solvent instead of the specific solvent (B), thereby obtaining a liquid crystal aligning agent (R1B), a liquid crystal aligning agent (R3B) to a liquid crystal aligning agent (R9B), respectively.

Comparative example 2B

With respect to the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and a liquid crystal aligning agent was prepared in the same manner as described in example 2B except that ethylene glycol dimethyl ether was used as the 2 nd solvent instead of the specific solvent (B), thereby obtaining a liquid crystal aligning agent (R2B).

In addition, comparative example XB (X is an integer of 1 to 9) corresponds to example XB. That is, in comparative example XB, the same polymer as in example XB was synthesized, and a liquid crystal aligning agent was prepared in the same manner as in example XB, except that butyl cellosolve or ethylene glycol dimethyl ether was used instead of the specific solvent (B).

[ example 10B ]

4.50g (0.018mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (BODA) as a tetracarboxylic dianhydride, 2.34g (0.0054mol) of the compound represented by the formula (d-4-2) (PBCH5DAB) as a diamine, and 1.92g (0.0126mol) of 3,5-diaminobenzoic acid (35DAB) were reacted with 26.3g of NMP at room temperature, and then reacted at 40 ℃ for 43 hours. To 30g of the polyamic acid solution was added NMP to prepare a 6 wt% solution, and 2.4g of acetic anhydride as an imidization catalyst and 1.8g of pyridine were added, followed by reaction at room temperature for 30 minutes and reaction at 110 ℃ for 4 hours. This solution was poured into a large amount of methanol, and the obtained white precipitate was filtered and dried to obtain white polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-2)) was measured, and it was 72%. This powder (0.6 g) was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and the compound (2B-a) as the specific solvent (B) to prepare a solution having a polyimide concentration of 6.0% by weight. To the solution, 0.4g (corresponding to 0.03g as 3-AMP) of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) was added, and the mixture was stirred at 50 ℃ for 15 hours, whereby a liquid crystal aligning agent was obtained (S10B). Further, the liquid crystal aligning agent is a compound having a solvent composition of NMP: d1: compound (2b-a) ═ 30: 20: 50 (weight ratio).

[ example 11B ]

The same operation as in example 10B was carried out except that the amount of PBCH5DAB used in the synthesis of polyamic acid was changed to 3.90g (0.0090mol) and the amount of 3,5-diaminobenzoic acid was changed to 1.37g (0.0090mol), thereby obtaining a polyamic acid solution. In addition, the same operation as in example 10B was performed using the obtained polyamic acid solution, to obtain polyimide powder. The imidization ratio of the obtained polyimide powder (polyimide (PI-3)) was measured, and it was 74%. This powder (0.6 g) was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a 1 st solvent and the compound (2B-B) as a specific solvent (B) to prepare a solution having a polyimide concentration of 6.0 wt%. To the solution, 0.8g (corresponding to 0.06g as 3-AMP) of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) was added, and the mixture was stirred at 50 ℃ for 15 hours, whereby a liquid crystal aligning agent was obtained (S11B). Further, the liquid crystal aligning agent is a compound having a solvent composition of NMP: d2: compound (2b-b) ═ 30: 30: 40 (weight ratio).

[ example 12B ]

A solution containing polyamic acid (PA-1) was prepared in the same manner as in example 1B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (2B-B) as the specific solvent (B), to obtain a solvent composition D1: compound (2b-b) ═ 60: 40 (weight ratio) and a solid content concentration of 6.0 wt% (S12B).

[ example 13B ]

A solution containing polyamic acid (PA-2) was prepared in the same manner as in the example 2B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the 1 st solvent and compound (2B-a) as the specific solvent (B), to obtain a solvent composition D2: compound (2b-a) ═ 50: 50 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S13B).

[ example 14B ]

A solution containing polyamic acid (PA-3) was prepared in the same manner as in the example 3B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as a 1 st solvent and compound (2B-a) as a specific solvent (B) to obtain a solution having a solvent composition of NMP: d1: compound (2b-a) ═ 40: 40: 20 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S14B).

[ example 15B ]

A solution containing polyamic acid (PA-4) was prepared in the same manner as in the example 4B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder and N, N '-tetraglycidyl-4, 4' -diaminodiphenylmethane (E1) as an additive were dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a 1 st solvent and a compound (2B-a) as a specific solvent (B) to obtain a solution having a solvent composition of NMP: d2: compound (2b-a) ═ 40: 40: 20 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S15B). The amount of the additive (E1) used was set to 5 parts by weight relative to the polyamic acid powder.

[ example 16B ]

A solution containing polyamic acid (PA-5) was prepared in the same manner as in the example 5B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (2B-a) as the specific solvent (B), to obtain a solvent composition D1: compound (2b-a) ═ 75: 25 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S16B).

[ example 17B ]

A solution containing polyamic acid (PA-6) was prepared in the same manner as in the example 6B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the 1 st solvent and compound (2B-a) as the specific solvent (B), to obtain a solvent composition D2: compound (2b-a) ═ 35: 65 (weight ratio) and a polyamic acid concentration of 6.0 wt% (S17B).

[ example 18B ]

A solution containing polyamic acid (PA-7) was prepared in the same manner as in the example 7B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ -butyrolactone (D3) as the 1 st solvent, and the compound (2B-a) as the specific solvent (B), to obtain a solution having a solvent composition of NMP: d3: compound (2b-a) ═ 30: 30: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% (S18B).

[ example 19B ]

A solution containing polyamic acid intermediate (PA-8) was prepared in the same manner as in the example 8B. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as the 1 st solvent and compound (2B-B) as the specific solvent (B) to obtain a solution having a solvent composition of NMP: d2: compound (2b-b) ═ 30: 30: 40 (weight ratio) and the polyamic acid concentration was 6.0 wt% (S19B).

[ example 20B ]

A powder of polyimide (PI-1) was obtained in the same manner as in the example 9B. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the 1 st solvent and compound (2B-a) as the specific solvent (B), to obtain a solvent composition D1: compound (2b-a) ═ 50: 50 (weight ratio) and a solid content concentration of 6.0 wt% (S20B).

< evaluation of storage stability >

Each of the obtained liquid crystal aligning agents was filtered through a 1.0 μm filter, stored at-30 ℃ for 1 month, and then returned to room temperature (25 ℃) to observe the presence or absence of precipitates in the liquid crystal aligning agent. The results are shown in tables 3 and 4 below. In tables 3 and 4, the case where no precipitate was observed in the liquid crystal aligning agent was indicated as "o", and the case where precipitate was observed in the liquid crystal aligning agent was indicated as "x".

< evaluation of printability >

Each of the prepared liquid crystal aligning agents was filtered through a 1.0 μm filter, stored at-15 ℃ for 6 months, and then returned to room temperature (25 ℃). Then, a liquid crystal alignment agent was applied to the transparent electrode surface of the glass substrate having the transparent electrode including the ITO film using a liquid crystal alignment film printer (manufactured by japan portrait printing (jet)). Then, the coating film was heated (pre-baked) on a hot plate at 80 ℃ for 1 minute to remove the solvent, and then heated (post-baked) on a hot plate at 200 ℃ for 10 minutes to form a coating film having an average film thickness of 0.06. mu.m. The coating film was observed with a microscope at a magnification of 20 times to check the presence or absence of uneven printing and pinholes. The evaluation was carried out in the following manner: the case where printing unevenness and pinholes were not substantially observed was evaluated as good printability (o), and the case where at least either of printing unevenness and pinholes was observed was evaluated as poor printability (x). The results are shown in tables 3 and 4 below.

[ Table 3]

[ Table 4]

Note that the abbreviations in table 3 and table 4 are as follows.

(acid dianhydride)

AN-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

AN-2: 2,3, 5-tricarboxylic cyclopentyl acetic dianhydride

AN-3: pyromellitic dianhydride

AN-4: bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride

(diamine)

DA-1: 1, 5-bis (4-aminophenoxy) pentane

DA-2: 2, 4-diamino-N, N-diallylaniline

DA-3: 3,5-diaminobenzoic acid cholestanyl ester

35 DAB: 3,5-diaminobenzoic acid

(monoamine)

MA-1: n-dodecylamine

(1 st solvent)

D1: 3-methoxy-N, N-dimethylpropionamide

D2: 3-butoxy-N, N-dimethylpropionamide

D3: gamma-butyrolactone

(the 2 nd solvent)

D4: ethylene glycol dimethyl ether

DEDG: diethylene glycol diethyl ether

BC: butyl cellosolve

(additives)

3-AMP: 3-aminomethylpyridine (compound represented by the formula (c-1-16))

E1: n, N, N ', N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane

< production and evaluation of photo-alignment FFS type liquid Crystal display element >

(1) Manufacture of FFS type liquid crystal display element using optical alignment method

an FFS type liquid crystal display device 10 as shown in fig. 1 was produced. First, a pair of a glass substrate 11a having an electrode pair on one surface thereof, and an opposite glass substrate 11b not provided with an electrode, in which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb-tooth shape are formed in this order, and a coating film is formed by an inkjet coating method using the liquid crystal aligning agent (S1B) obtained as described above on the surface having a transparent electrode of the glass substrate 11a and the surface of the opposite glass substrate 11 b. In addition, before the liquid crystal aligning agent (S1B) was applied to the substrate, the solvent composition was set to "NMP: compound (2b-a) ═ 60: 40 (weight ratio) ", the liquid crystal alignment agent was prepared so that the viscosity became 18cP, and the viscosity was adjusted to coat the liquid crystal alignment agent on the substrate.

Then, the coating film was prebaked with a hot plate at 80 ℃ for 1 minute, and then heated at 230 ℃ for 15 minutes in an oven with a nitrogen gas substitution in the storage (postbaking), thereby forming a film having an average film thickness ofCoating film of (3). Plan view of the top electrode 13 to be used hereinFig. 2(a) and 2(b) show the results. Fig. 2(a) is a plan view of the top electrode 13, and fig. 2(b) is an enlarged view of a portion C1 surrounded by a broken line in fig. 2 (a). In this example, a substrate having a top electrode with a line width d1 of 4 μm and an inter-electrode distance d2 of 6 μm was used. The top electrode 13 is a driving electrode using four systems of an electrode a, an electrode B, an electrode C, and an electrode D. Fig. 3 shows a structure of a driving electrode of the liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four systems of drive electrodes, and each region of the four systems of drive electrodes becomes a pixel region.

Then, polarized ultraviolet light 300J/m containing 313nm bright line was irradiated from the substrate normal direction to each surface of the coating films using Hg-Xe lamp and Glan-Taylor prism (Glan-Taylor prism), respectively²Thereby obtaining a pair of substrates having liquid crystal alignment films. In this case, the light irradiation process is performed after setting the polarization plane direction such that the direction of the line segment projecting the polarization plane of the polarized ultraviolet rays onto the substrate is the direction of the double arrow in fig. 2(a) and 2(b) with respect to the substrate normal direction as the irradiation direction of the polarized ultraviolet rays.

Then, an epoxy resin adhesive containing alumina balls having a diameter of 5.5 μm was applied to the outer periphery of the surface having the liquid crystal alignment film of the 1 substrate by screen printing, and then the liquid crystal alignment films of the pair of substrates were faced to each other, overlapped and pressure-bonded so that the directions of projecting the polarization planes of the polarized ultraviolet rays to the substrates were parallel, and the adhesive was heat-cured at 150 ℃ for 1 hour. Then, a liquid crystal "MLC-6221" manufactured by Merck corporation was filled into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, it was heated to 150 ℃ and slowly cooled to room temperature.

Next, polarizing plates are bonded to both outer sides of the substrate, thereby manufacturing an FFS type liquid crystal display device. At this time, 1 polarizing plate was attached so that the polarization direction thereof was parallel to the direction in which the polarization plane of the polarized ultraviolet ray of the liquid crystal alignment film was irradiated to the substrate surface, and the other polarizing plate was attached so that the polarization direction thereof was perpendicular to the polarization direction of the former polarizing plate.

The above-described method was repeated to manufacture a total of 5 FFS type liquid crystal display devices, and the liquid crystal alignment properties, the voltage holding ratio, the heat resistance, the frame unevenness resistance, and the image sticking characteristics were evaluated one by one. In any case, ultraviolet irradiation under voltage application was not performed.

(2) Evaluation of liquid Crystal alignment Properties

In the FFS type liquid crystal display device manufactured as described above, the presence or absence of an abnormal region of a change in brightness when a voltage of 5V was turned ON/OFF (applied/released) was observed with a microscope at a magnification of 50 times. The evaluation was carried out in the following manner: the case where no abnormal region was observed was defined as "good" liquid crystal alignment, and the case where an abnormal region was observed was defined as "poor" liquid crystal alignment. In this liquid crystal display element, the liquid crystal alignment property is "good".

(3) Evaluation of Voltage holding ratio

In the FFS type liquid crystal display device manufactured as described above, after a voltage of 5V was applied at intervals of 167 msec at an application time of 60 μ sec at 23 ℃, a Voltage Holding Ratio (VHR) after 167 msec from the release of the application was measured, and as a result, the voltage holding ratio was 99.4%. Further, the measurement apparatus was VHR-1 manufactured by Toyang Technica (Strand).

(4) Evaluation of Heat resistance

The voltage holding ratio was measured in the same manner as in the evaluation of the voltage holding ratio in (3), and this value was defined as an initial VHR (VHR)_BF). Then, the liquid crystal display element after the initial VHR measurement was left to stand in an oven at 100 ℃ for 500 hours. Then, after the liquid crystal display element was left to stand at room temperature and left to cool to room temperature, the voltage holding ratio was measured in the same manner as described above, and the value was set to VHR_AF. Further, the rate of change of the voltage holding ratio (Δ VHR (%)) before and after applying thermal stress was determined from the following equation (EX-2).

△VHR(％)＝((VHR_BF-VHR_AF)÷VHR_BF)×100(EX-2)

The evaluation of heat resistance was performed as follows: the heat resistance was evaluated as "good" when the change rate Δ VHR was less than 4%, as "acceptable" when the change rate Δ VHR was 4% or more and less than 5%, and as "poor" when the change rate Δ VHR was 5% or more. As a result, Δ VHR was 2.9%, and the heat resistance of the liquid crystal display element was "good".

(5) Resistance to unevenness of the sealant periphery (resistance to frame unevenness)

The manufactured FFS type liquid crystal display element was stored at 25 ℃ and 50% RH for 30 days, and then was driven at an ac voltage of 5V to observe a lighting state. The evaluation is as follows: if no difference in brightness (blacker or whiter) is seen around the sealant, "good" is evaluated if the difference in brightness (blacker or whiter) is seen around the sealant but the difference in brightness disappears within 5 minutes after lighting, "good" is evaluated if the difference in brightness (blacker or whiter) is seen around the sealant but the difference in brightness disappears within more than 5 minutes and 20 minutes after lighting, "clear" is evaluated, and "bad" is evaluated if the difference in brightness still appears after 20 minutes. As a result, in this liquid crystal display element, no luminance difference was observed around the sealant, and the frame unevenness resistance was judged to be "excellent".

(6) Evaluation of residual image characteristics (DC residual image evaluation)

The fabricated photo-alignment liquid crystal display device was placed at 25 ℃ under 1 atmosphere. The bottom electrode is set to be a common electrode for all the four systems of drive electrodes, and the potential of the bottom electrode is set to 0V potential (ground potential). The electrode B and the electrode D were brought into a 0V applied state by short-circuiting the common electrode, and a combined voltage including an AC voltage of 3.5V and a DC voltage of 1V was applied to the electrode A and the electrode C for 2 hours. After 2 hours had elapsed, a voltage of 1.5V was applied to all of the electrodes A to D. Then, the time from the time when the application of the voltage having an ac voltage of 1.5V was started to all the drive electrodes until the difference in luminance between the drive stress applied region (the pixel region of the electrode a and the electrode C) and the drive stress non-applied region (the pixel region of the electrode B and the electrode D) was visually undetectable was measured, and this was defined as the residual image erasing time. Further, the shorter the time, the more difficult it is to generate an afterimage. The evaluation was carried out in the following manner: as a result of evaluating "good" when the afterimage erasing time is less than 30 seconds, evaluating "ok" when the afterimage erasing time is 30 seconds or more and less than 120 seconds, and evaluating "bad" when the afterimage erasing time is 120 seconds or more, the liquid crystal display element of the present example evaluated "good" when the afterimage erasing time is 1 second.

As shown in tables 3 and 4, the liquid crystal aligning agents of the examples using the specific solvent (B) were good in both storage stability during low-temperature storage and printability after low-temperature storage. In contrast, the liquid crystal aligning agents of the comparative examples were poor in storage stability and printability after storage at low temperatures. From this, it was found that by using the specific solvent (B), the coating property to the substrate can be secured and the storage stability can be improved.

< Synthesis of polyimide >

Synthetic example 1: synthesis of polyimide (PI-1C) ]

22.4g (0.1mol) of 2,3, 5-tricarboxylylcyclopentylcacetic dianhydride (2,3, 5-tricarboxylylcyclopentaacetic acid dianhydride, TCA) as tetracarboxylic dianhydride, 8.6g (0.08mol) of p-Phenylenediamine (PDA) as diamine, and 10.5g (0.02 mol) of cholestanyl 3, 5-diaminobenzoate (3,5-diaminobenzoic acid cholestanyl, HCDA) were dissolved in 166g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ℃ for 6 hours to obtain a solution containing 20% by weight of polyamic acid. A small amount of the obtained polyamic acid solution was collected, N-methyl-2-pyrrolidone was added to the solution to obtain a solution having a polyamic acid concentration of 10% by weight, and the solution viscosity was measured to be 90 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, 11.9g of pyridine and 15.3g of acetic anhydride were added thereto, and dehydration ring-closure reaction was performed at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent substitution with fresh NMP (pyridine and acetic anhydride used in the dehydration ring-closure reaction were removed outside the system by this operation; the same applies hereinafter), whereby a solution containing polyimide (PI-1C)26 wt% having an imidization rate of about 68% was obtained. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 45 mPas.

[ Synthesis example 2: synthesis of polyimide (PI-2C)

22.5g (0.1mol) of TCA as tetracarboxylic dianhydride, 7.6g (0.07 mol) of PDA as diamine, 5.2g (0.01 mol) of HCDA5 and 4.0g (0.02 mol) of 4,4 '-diaminodiphenylmethane (4,4' -diamino diphenyl methane, DDM) were dissolved in 157g of NMP and reacted at 60 ℃ for 6 hours to obtain a solution containing 20 wt% of polyamic acid. 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 weight, and the solution viscosity was measured to be 110 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, 16.6g of pyridine and 21.4g of acetic anhydride were added thereto, and dehydration ring-closure reaction was performed at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was solvent-replaced with fresh NMP to obtain a solution containing polyimide (PI-2C) at a content of 26 wt% and having an imidization rate of about 82%. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the solution viscosity was measured to be 62mPa · s.

[ Synthesis example 3: synthesis of polyimide (PI-3C) ]

24.9g (0.10 mol) of 2,4,6, 8-tetracarboxybicyclo [3.3.0] octane-2: 4,6:8-dianhydride (BODA) as tetracarboxylic dianhydride, 8.6g (0.08mol) of PDA as diamine, and 10.4g (0.02 mol) of HCDA were dissolved in NMP176g and reacted at 60 ℃ for 6 hours to obtain a solution containing 20% by weight of polyamic acid. 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 weight, and the solution viscosity was measured to be 103 mPas.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 7 wt%, 11.9g of pyridine and 15.3g of acetic anhydride were added thereto, and dehydration ring-closure reaction was performed at 110 ℃ for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was solvent-replaced with fresh NMP to obtain a solution containing polyimide (PI-3C) at a content of 26 wt% and having an imidization rate of about 71%. A small amount of the obtained polyimide solution was collected, NMP was added thereto to prepare a solution having a polyimide concentration of 10% by weight, and the measured solution viscosity was 57mPa · s.

< preparation of liquid Crystal Aligning agent >

[ example 1C ]

To a solution containing 100 parts by weight of the synthesized polyimide (PI-1C), NMP, ethylene glycol mono-n-butyl ether (butyl cellosolve, BC) and a compound represented by the following formula (b1-1) (hereinafter referred to as "compound (b 1-1)") were added as solvents to prepare a polyimide resin having a solvent composition of NMP: BC: compound (b1-1) ═ 30: 50: 20 (weight ratio) and a solid content concentration of 6.5 wt%. The solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal aligning agent (S-1).

[ solution 30]

Example 2C to example 18C, and comparative example 1C to comparative example 4C

Liquid crystal aligning agents (S-2) to (S-18) and liquid crystal aligning agents (SR-1) to (SR-4) were prepared in the same manner as in example 1C, except that the polyimide and solvent compositions used were changed as shown in Table 5 below.

< evaluation of printability >

The respective liquid crystal aligning agents prepared above were evaluated for printability. Evaluation was performed in the following manner. First, each of the prepared liquid crystal aligning agents was applied to the transparent electrode surface of a glass substrate having a transparent electrode including an ITO film, using a liquid crystal alignment film printer (manufactured by japan portrait printer, angus ink (Angstrom) model "S40L-532) under the condition that the dropping amount of the liquid crystal aligning agent to an anilox roll was repeatedly 20 drops (about 0.2 g). The coating of the substrate was performed 20 times at 1 minute intervals while using a new substrate.

Then, the liquid crystal aligning agent was dispensed (single pass) onto the anilox roller at intervals of 1 minute, and the total of 10 times of operations (hereinafter referred to as idling) for bringing the anilox roller into contact with the printing plate were performed (during this period, printing on the glass substrate was not performed). The idling is not an operation performed in a normal manufacturing process of a liquid crystal display element, but an operation performed to intentionally perform printing of a liquid crystal alignment agent on a substrate under a severe condition.

After 10 times of idling, main printing was performed using a glass substrate. In the main printing, 5 substrates were placed at 30 second intervals after idling, and each substrate coated with a liquid crystal aligning agent was heated at 80 ℃ for 1 minute (pre-baking) to remove the solvent, and then heated at 200 ℃ for 10 minutes (post-baking) to form a coating film having a film thickness of about 80 nm. The pattern edge portion of the coating film (the outer peripheral portion of the printed pattern) was observed with a microscope at a magnification of 20 times to evaluate the printability. The evaluation was carried out in the following manner: the case where no precipitate (considered to be polyimide) was observed in the first main printing after the idling was evaluated as good (o), the case where the precipitate was observed in the first main printing after the idling but disappeared during the 5 main printings was evaluated as good (Δ), and the case where the precipitate was still observed after the 5 main printings was evaluated as bad (x). The evaluation results are shown in table 5 below. In addition, in the liquid crystal aligning agent having good printability, it was found through experiments that the precipitates were improved (disappeared) during the period of continuous charging into the substrate.

The printability of the liquid crystal aligning agent was evaluated by performing the same operation as described above except that the number of times of idling was changed to 15 times, 20 times, and 25 times, respectively. The evaluation results are shown in table 5 below.

< evaluation of drying level of Membrane surface >

The coating film after the pre-baking was evaluated for the dryness level of the film surface in the above "evaluation of printability". The evaluation was carried out in the following manner: the film was evaluated as good (o) when no sticky feeling remained when the film surface was touched with a hand, and as bad (x) when the film surface was touched with a hand. The evaluation results are shown in table 5 below. Here, evaluation was performed using a printed substrate subjected to main printing performed after 10 times of idling.

[ Table 5]

Note that symbols of the solvent composition in table 5 are as follows.

a: n-methyl-2-pyrrolidone (NMP)

b: ethylene glycol mono-n-butyl ether (BC)

d: compound (b1-1)

e: a compound represented by the following formula (b2-1)

f: a compound represented by the following formula (b2-2)

g: n-vinyl-2-pyrrolidone

h: n-cyclohexyl-2-pyrrolidinone

i: n-octyl-2-pyrrolidone

[ solution 31]

Regarding printability, in the liquid crystal aligning agent of the example, no precipitate was observed from the 1 st main printing after 10 times of idling. This is also the case after 15 idles. When the number of times of idling was increased to 20 or 25, the precipitates were observed in the 1 st main printing, but the precipitates disappeared during the period from the end of the 5 main printing. Thus, it can be seen that: the liquid crystal aligning agent of the examples hardly generates precipitates during printing and has good printability.

Claims (8)

1. A composition containing a polyamic acid polymer, comprising:

At least one polymer (A) selected from the group consisting of polyamic acids, polyimides, and polyamic acid esters; and a solvent;

The solvent comprises: a second solvent (2) containing a specific solvent (B) which is at least one selected from the group consisting of a compound represented by the following formula (B1) and a compound represented by the following formula (B2); and a 1 st solvent as a good solvent for the polymer (A);

In the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, and n is an integer of 0 to 2; in the formula (b2), m is an integer of 0-2;

The content of the specific solvent (B) is 1 to 70% by weight of the total amount of the solvents,

the content ratio of the 1 st solvent is 5 to 99 wt% with respect to the total amount of solvents contained in the composition, and

The amount of the 2 nd solvent used is 0.03 times (by weight) or more and 2.5 times (by weight) or less relative to the amount of the 1 st solvent used.

2. A liquid crystal aligning agent comprising:

At least one polymer (A) selected from the group consisting of polyamic acids, polyimides, and polyamic acid esters; and a solvent;

The solvent comprises: a second solvent (2) containing a specific solvent (B) which is at least one selected from the group consisting of a compound represented by the following formula (B1) and a compound represented by the following formula (B2); and a 1 st solvent as a good solvent for the polymer (A);

In the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, and n is an integer of 0 to 2; in the formula (b2), m is an integer of 0-2;

The content of the specific solvent (B) is 1 to 70% by weight of the total amount of the solvents,

The content ratio of the 1 st solvent is 5 to 99 wt% based on the total amount of the solvents contained in the liquid crystal aligning agent, and

The amount of the 2 nd solvent used is 0.03 times (by weight) or more and 2.5 times (by weight) or less relative to the amount of the 1 st solvent used.

3. The liquid crystal aligning agent according to claim 2, wherein the polymer (A) comprises a polymer having a partial structure derived from at least one diamine selected from the group consisting of compounds represented by the following formulae (d-1) to (d-5), respectively,

In the formula (d-1), X¹And X²Each independently being a single bond, -O-, -S-, -OCO-or-COO-, Y¹is an oxygen atom or a sulfur atom, R¹¹And R¹²Each independently is C1-C3 alkanediyl, R⁸And R⁹Each independently is a hydrogen atom or a protecting group; n1 is 0 or 1, n2 and n3 are integers satisfying n2+ n3 ═ 2 in the case where n1 is 0, and n2 is n3 ═ 1 in the case where n1 is 1; in the formula (d-2), X³Is a single bond, -O-or-S-, and m1 is an integer of 0-3; when m1 is 0, m2 is an integer of 1 to 12, and when m1 is an integer of 1 to 3, m2 is 2; in the formula (d-3), R³Is C1-12 monovalent hydrocarbon group, R⁴Is a hydrogen atom or a C1-12 monovalent hydrocarbon group, R⁵And R⁶Each independently is a hydrogen atom or a methyl group; in the formula (d-4), X⁴and X⁵Each independently is a single bond, -O-, -COO-or-OCO-, R⁷Is C1-3 alkanediyl, A⁴Is a single bond or an alkanediyl group having 1 to 3 carbon atoms; a is 0 or 1, b is an integer of 0-2, c is an integer of 1-20, and k is 0 or 1; wherein a and b are not both 0; in the formula (d-5), A⁵Represents a single bond, an alkanediyl group having 1 to 12 carbon atoms or a fluoroalkanediyl group having 1 to 6 carbon atoms, A⁶represents-O-, -COO-, -OCO-, -NHCO--CONH-or-CO-, A⁷Represents a monovalent organic group having a steroid skeleton.

4. The liquid crystal aligning agent according to claim 2 or 3, wherein the polymer (A) is a polymer having a partial structure derived from at least one tetracarboxylic dianhydride selected from the group consisting of a compound represented by the following formula (t-1), 2,3, 5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride,

In the formula (t-1), X⁷、X⁸、X⁹And X¹⁰Each independently represents a single bond or a methylene group, and j is an integer of 1 to 3.

5. The liquid crystal aligning agent according to claim 2 or 3, further comprising an amine compound (C) having 1 primary amino group and a nitrogen-containing aromatic heterocyclic ring bonded to a chain having 1 to 20 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in a molecule, wherein the nitrogen-containing aromatic heterocyclic ring is a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, a benzimidazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a naphthyridine ring, a quinoxaline ring, a phthalazine ring, a triazine ring, a nitrogen azepine ring, a diazepine ring, an acridine ring, a phenazine ring, a phenanthroline ring, an oxazole ring, a thiazole ring, a carbazole ring, a thiadiazole ring, a phenothiazine ring, or an oxadiazole ring.

6. The liquid crystal aligning agent according to claim 5, wherein the amine compound (C) is a compound represented by the following formula (C-1),

H₂N-A¹-A² (c-1)

In the formula (c-1), A¹A divalent organic group which is a chain hydrocarbon group having 1 to 20 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms，A²Is a nitrogen-containing aromatic heterocycle; wherein the primary amino group in the formula is bonded to A¹The nitrogen-containing aromatic heterocycle is a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, a benzimidazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a naphthyridine ring, a quinoxaline ring, a phthalazine ring, a triazine ring, an azepine ring, an acridine ring, a phenazine ring, a phenanthroline ring, an oxazole ring, a thiazole ring, a carbazole ring, a thiadiazole ring, a benzothiazole ring, a phenothiazine ring or an oxadiazole ring.

7. A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of claims 2 to 6.

8. A liquid crystal display element comprising the liquid crystal alignment film according to claim 7.