TW201331268A - Liquid crystal alignment agents for photo-alignment, method for forming liquid crystal alignment layer, liquid crystal alignment layer, and liquid crystal display device - Google Patents

Abstract

A purpose of the present invention is to provide a liquid crystal alignment agent for photo-alignment capable of forming a liquid crystal alignment film having excellent liquid crystal alignment characteristic with a photo-alignment method. A forming method of the liquid crystal alignment film by using the liquid crystal alignment agent for photo-alignment and the liquid crystal alignment film are also provided. Besides, a liquid crystal display device is provided, including the liquid crystal alignment film and having various excellent electrical properties such as electrical properties and image sticking characteristics in addition to liquid crystal alignment characteristics. The liquid crystal alignment agent for photo-alignment contains a [A] polymer having a structural unit (I) containing a structure represented by the following formula (1). Moreover, the [A] polymer is preferred to be a polyamic acid or a polyimide.

Description

Liquid alignment agent for light alignment, method for forming liquid crystal alignment film, and liquid crystal Alignment film and liquid crystal display element

The present invention relates to a liquid alignment agent for photoalignment, a method for forming a liquid crystal alignment film, a liquid crystal alignment film, and a liquid crystal display device.

Liquid crystal displays (LCDs) are widely used in televisions or various displays and the like. The LCD display element has a liquid crystal cell such as a twisted nematic (TN) type, a super twisted nematic (STN) type, or an In Plane Switching (IPS) type, and a known IPS is also known. (Fringe Field Switching, FFS) type, etc., which improves the aperture ratio of the display element portion and increases the aperture ratio of the display element portion (see Japanese Patent Laid-Open No. 56-91277 and Japan) Patent Laid-Open No. Hei 1-120528).

A method of aligning a liquid crystal of such a liquid crystal cell is known in which a method of rubbing treatment is used, that is, an organic film is formed on a surface of a substrate, and a surface of the organic film is rubbed in one direction with a cloth such as rayon; a method of obliquely vaporizing ruthenium oxide on a surface of a substrate; a method of forming a monomolecular film having a long-chain alkyl group using a Langmuir-Brodgett method (LB method); A photo-alignment method in which a photosensitive film such as a cinnamate, a polyimide or a polyacrylamide is irradiated with a polarized or non-polarized radiation to impart a liquid crystal alignment ability (refer to Japanese Patent Laid-Open No. Hei 6-287453, Japanese Patent No. Japanese Patent Publication No. 2003-307736 and Japanese Patent Laid-Open No. Hei 9-297313 Newspaper) and so on. Among these methods, development of the above-described photoalignment method capable of achieving uniform liquid crystal alignment without generating static electricity or dust and precisely controlling the liquid crystal alignment direction is being carried out. According to this light alignment method, a plurality of regions having different liquid crystal alignment directions can be arbitrarily formed on one substrate by using a photomask or the like when irradiating the radiation. However, the sensitivity of the conventional photosensitive film containing a polyimine resin, a poly phthalic acid, etc. is not sufficient, and there exists a fault which has the large cumulative exposure amount in order to provide liquid-crystal aligning property. Further, the liquid crystal alignment property of the liquid crystal alignment film obtained from the above-mentioned photosensitive film is not sufficient. Further, the properties such as electrical characteristics and afterimage characteristics of the liquid crystal display element including such a liquid crystal alignment film are not sufficiently satisfied.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. SHO 56-91277

[Patent Document 2] Japanese Patent Laid-Open No. Hei 1-120528

[Patent Document 3] Japanese Patent Laid-Open No. Hei 6-287453

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2003-307736

[Patent Document 5] Japanese Patent Laid-Open No. Hei 9-297313

An object of the present invention is to provide a liquid crystal alignment agent for photoalignment which can form a liquid crystal alignment film which is excellent in radiation sensitivity and has sufficient liquid crystal alignment. Further, a liquid crystal alignment film using such a liquid alignment alignment agent for light alignment and a method for forming the same are provided, and a liquid crystal display including such a liquid crystal alignment film and having excellent electrical properties and afterimage characteristics is also provided. element.

The invention for solving the above problems is a liquid alignment agent for photoalignment comprising: [A] a polymer having a structural unit (I) having a structure represented by the following formula (1) (hereinafter also referred to as "[A] polymer").

(In the formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms. Ar ¹ is a group containing an aromatic ring. ^* represents a hydrogen atom or a bond. On other bases)

The liquid-aligning liquid-aligning agent of the present invention contains the [A] polymer having the specific structure of the above formula (1), thereby improving the radiation sensitivity, so that a liquid crystal alignment film having excellent liquid crystal alignment properties can be formed with a low irradiation amount. . In addition, the reason why the liquid crystal alignment agent contains the [A] polymer having the specific structure described above and the radiation sensitivity is improved is not necessarily clear, and can be estimated, for example, as follows. The specific structural moiety in which the quinone imine group represented by the above formula (1) is bonded to a carbon atom bonded to a group containing an aromatic ring is easily broken by irradiation of radiation, and thus it is easy to The decomposition of the main chain of the [A] polymer or the like is generated, and the light alignment is generated with high sensitivity by polarized light. As a result, when the liquid alignment alignment agent for light alignment is used, it becomes possible to use less irradiation. Achieve excellent light alignment by volume. In addition, when a liquid crystal alignment film formed by the liquid alignment alignment agent is used, a liquid crystal display element having excellent electrical properties and afterimage characteristics can be produced.

The [A] polymer is preferably polylysine (hereinafter also referred to as "polyglycine (A1)") or polyimine (hereinafter also referred to as "polyimine (A2)"). Here, polylysine refers to a polymer having a structural unit containing a proline structure, and the proline structure is not imidized, and the ruthenium iodide ratio is 0%. In addition, the term "polyimine" refers to a polymer obtained by at least one of the guanidine structures of the polyamic acid.

The structural unit (I) is preferably a structural unit represented by the following formula (2) or (3).

(In the formulae (2) and (3), R ¹ and Ar ¹ have the same meaning as the above formula (1). R ² and R ³ are each independently a tetravalent organic group)

In the liquid alignment agent for light alignment, since the [A] polymer has the structural unit (I) having the above specific structure, the radiation sensitivity is improved and the optical alignment property is more excellent.

Preferably, the [A] polymer is at least one polymer selected from the group consisting of polylysine and polyimine, and the polyamine comprises [a] represented by the following formula (4). a reaction of a diamine component (hereinafter also referred to as "[a] diamine component") of a diamine compound with a [b] tetracarboxylic dianhydride component which is dehydrated by the polyamidamine Closed loop.

(In the formula (4), R ¹ and Ar ^{1 are} synonymous with the above formula (1))

As the liquid alignment alignment agent for photoalignment, the [A] polymer is a polyamic acid and/or a polyimine obtained by a reaction of a [a] diamine component and a [b] tetracarboxylic dianhydride component. Thereby, the optical alignment property is improved, so that a liquid crystal alignment film having more excellent liquid crystal alignment properties can be formed. Further, when such a liquid crystal alignment film is used, a liquid crystal display element having more excellent properties such as electrical characteristics and afterimage characteristics can be produced.

The [b]tetracarboxylic dianhydride component preferably contains at least the tetracarboxylic dianhydride represented by the following formula (5).

(In the formula (5), Y is a group containing an aromatic ring or an alicyclic ring. X ¹ and X ² are each independently a single bond, -O-, -S- or -NH-)

Since the [A] polymer is a polylysine obtained by reacting the [a] diamine component with the [b] tetracarboxylic dianhydride component of the above specific structure, the photoalignment liquid crystal alignment agent can provide radiation. The sensitivity is further improved. Further, the liquid crystal alignment film obtained by the liquid alignment liquid crystal alignment agent is more excellent in liquid crystal alignment property. In addition, when such a liquid crystal alignment film is used, a liquid crystal display element having more excellent properties such as electrical characteristics and afterimage characteristics can be produced.

The method for forming a liquid crystal alignment film of the present invention comprises: (1) a step of forming a coating film on a substrate using the liquid alignment alignment agent for photoalignment of the present invention; and (2) forming a liquid crystal alignment film by irradiating the coating film with light. A step of.

According to the formation method of the present invention, since the liquid alignment agent for light alignment is used, a liquid crystal alignment film having excellent liquid crystal alignment properties can be formed with a small amount of exposure. Further, by using such a liquid crystal alignment film, it is possible to manufacture a liquid crystal display element having sufficiently satisfactory properties such as electrical characteristics and afterimage characteristics.

The present invention also encompasses a liquid crystal alignment film formed by the liquid alignment liquid crystal alignment agent. Since the liquid crystal alignment film of the present invention is formed by the liquid alignment alignment agent, in the formation step, the liquid crystal alignment ability can be imparted by the radiation of a low irradiation amount, the production efficiency is good, and the manufacturing cost can be reduced. Moreover, the liquid crystal alignment film is excellent in liquid crystal alignment, because The liquid crystal display element including the liquid crystal alignment film can sufficiently satisfy properties such as electrical characteristics and afterimage characteristics.

The liquid crystal display element of the present invention comprises the liquid crystal alignment film. Since the liquid crystal alignment film is excellent in liquid crystal alignment, the liquid crystal display element including the liquid crystal alignment film can sufficiently satisfy properties such as electrical characteristics and afterimage characteristics.

In addition, "light" and "radiation" used herein for "optical alignment" are used in the same sense, and are concepts including visible light rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, and the like.

Since the liquid alignment alignment agent for optical alignment of the present invention has high radiation sensitivity and can form a liquid crystal alignment film having excellent liquid crystal alignment properties with low radiation amount, the production efficiency is good and the production cost can be reduced. Further, the liquid crystal display element including the liquid crystal alignment film is excellent in electrical properties and afterimage characteristics. Therefore, the liquid alignment alignment agent for liquid alignment, the liquid crystal alignment film, the method for forming the liquid crystal alignment film, and the liquid crystal display device of the present invention are suitably used for liquid crystal display devices such as IPS type and FFS type.

The above described features and advantages of the present invention will be more apparent from the following description.

<Liquid alignment agent for light alignment>

The liquid alignment agent for photoalignment of the present invention contains [A] a polymer. The [A] polymer has a structure list including the structure represented by the above formula (1) Yuan (I). In this way, the liquid-aligning liquid-aligning agent contains the [A] polymer having the specific structure described above, whereby the radiation sensitivity can be improved, and a liquid crystal alignment film having excellent liquid crystal alignment properties can be formed with a low irradiation amount of radiation. Further, the liquid crystal display element including the liquid crystal alignment film is excellent in electrical properties and afterimage characteristics. The liquid-aligning agent for photoalignment of the present invention may contain other components in addition to the essential component [A] as long as the effects of the present invention are not impaired. Hereinafter, each component will be described in detail.

<[A]polymer>

The [A] polymer is a polymer having a structural unit (I). The polymer [A] is not particularly limited as long as it is a polymer having the above structural unit (I), and is preferably polyamic acid (A1) or polyimine (A2). [A] The polymer is a polyamic acid (A1) or a polyimine (A2) having a structural unit (I), and thus the liquid alignment alignment agent can form a liquid crystal alignment film having more excellent liquid crystal alignment. . Further, the [A] polymer may have other structural units in addition to the structural unit (I) within a range that does not impair the effects of the present invention.

[Structural unit (I)]

The structural unit (I) contains the structure represented by the above formula (1).

In the above formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms. Ar ¹ is a group containing an aromatic ring. ^* indicates a hydrogen atom or a site bonded to another base.

Examples of the alkyl group having 1 to 10 carbon atoms and the cycloalkyl group having 3 to 10 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a propyl group, a butyl group, a cyclopropyl group, and a cyclobutyl group. Among these groups, a methyl group and an ethyl group are preferable.

R ¹ is preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom.

Examples of the group containing an aromatic ring represented by Ar ¹ include a group represented by the following formula (a), and a group selected from the group consisting of -COO-, -NH-, -O-, and -S-. A base or the like in which at least one type of base is combined.

In the above formula (a), R ^A and R ^B each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms. n is an integer from 0 to 5. When n is 2 or more, a plurality of R ^A and R ^B may be the same or different. Ar ² is an aryl group having 6 to 20 carbon atoms. ^** represents a moiety bonded to a carbon atom to which R ¹ is bonded in the above formula (1).

Examples of the alkyl group having 1 to 10 carbon atoms and the cycloalkyl group having 3 to 10 carbon atoms represented by the above-mentioned R ^A and R ^B include the same groups as those exemplified as the respective groups represented by the above R ¹ .

The above R ^A and R ^{B are} preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom.

The n is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0, from the viewpoint of further improving the sensitivity of the liquid alignment alignment agent for photoalignment.

Examples of the aryl group having 6 to 20 carbon atoms include phenylene, naphthylene, and anthrylene. Among the aryl groups, a phenyl group and a naphthyl group are preferred, and a phenyl group is more preferred.

Examples of the group in which the aryl group having 6 to 20 carbon atoms and at least one group selected from the group consisting of -COO-, -NH-, -O-, and -S- are combined, and benzoic acid is exemplified. A group in which a group is combined with at least one group selected from the group consisting of -COO-, -NH-, -O-, and -S-. Among these groups, a group in which a phenyl group and -COO- are combined is preferred.

The above Ar ¹ is preferably a group containing an aromatic ring directly bonded to a carbon atom to which R ¹ is bonded, and more preferably a phenyl group, an anthranyl group, a phenyl group directly bonded to the above carbon atom and - Further, the group in which COO- is combined is more preferably a group in which a phenyl group and a phenyl group directly bonded to the above carbon atom are combined with -COO-.

The structural unit (I) is not particularly limited as long as it is a structural unit having a structure represented by the above formula (1), and is preferably a structural unit represented by the above formula (2) or (3).

In the above formulas (2) and (3), R ¹ and Ar ¹ have the same meanings as in the above formula (1). R ² and R ³ are each independently a tetravalent organic group.

Examples of the tetravalent organic group represented by R ² and R ³ include a tetravalent aliphatic chain hydrocarbon group having 1 to 20 carbon atoms; a tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms; and a carbon number of 6 a tetravalent aromatic hydrocarbon group of ~20; a group selected from the group consisting of an aliphatic chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 4 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms; A group in which at least one group of the group is combined with at least one group selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH-.

Examples of the tetravalent aliphatic chain hydrocarbon group having 1 to 20 carbon atoms include, for example, four hydrogen atoms removed from an aliphatic chain hydrocarbon such as methane, ethane, propane, butane, pentane, hexane or octane. Base and so on.

Examples of the tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include alicyclic groups such as cyclobutane, cyclopentane, cyclohexane, cyclooctane, bicyclooctane, adamantane, and tricycloundecane. A group obtained by removing four hydrogen atoms from a hydrocarbon. Among these, a group obtained by removing four hydrogen atoms from cyclobutane, cyclopentane, bicyclooctane or tricycloundecane is preferable, and a group obtained by removing four hydrogen atoms from cyclopentane is more preferable.

Examples of the tetravalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a group obtained by removing four hydrogen atoms from an aromatic hydrocarbon such as benzene, naphthalene or anthracene. Among these groups, a group obtained by removing four hydrogen atoms from benzene is preferable.

The at least one group selected from the group consisting of an aliphatic chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 4 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms An aliphatic chain hydrocarbon group having 1 to 20 carbon atoms in a group of at least one group selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH- An alicyclic hydrocarbon group having 4 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may be, if necessary, removed from each of the aliphatic chain hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons exemplified above. The resulting group or three hydrogen atoms and the like. Among these groups, an aromatic hydrocarbon group having 6 to 20 carbon atoms and at least 1 selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH- are preferable. The group in which the groups are combined is more preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms and at least 1 selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH-. Further, a group in which a group of groups is combined is more preferably a group in which an aromatic hydrocarbon group having 6 to 10 carbon atoms is combined with -COO-.

The above R ² and R ^{3 are} preferably selected from the group consisting of an aliphatic chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 4 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms. a group in which at least one group of the group is combined with at least one group selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH-, more preferably having a carbon number of a group of 6 to 20 aromatic hydrocarbon groups and at least one group selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH-, and more preferably carbon. A group of 6 to 10 aromatic hydrocarbon groups combined with -COO-.

The structural unit (I) can be obtained by polymerizing a diamine compound containing a part of the structure represented by the above formula (1) and tetracarboxylic dianhydride, as described in detail in the synthesis method of the [A] polymer described later. And get. Further, the diamine compound is preferably a compound represented by the above formula (4), and the tetracarboxylic dianhydride is preferably a compound represented by the above formula (5). These compounds are described in detail in the synthesis method of the [A] polymer.

The content of the structural unit (I) in the polymer [A] is preferably 10 mol% or more and 100 mol% or less, more preferably 60 mol% or more and 100 mol% or less, still more preferably 80 mol% or more and 100 mol% or less. It is particularly preferably 90 mol% or more and 100 mol% or less. By making the content ratio of the structural unit (I) in the [A] polymer to the above specific range, The light alignment liquid crystal alignment agent can further improve the radiation sensitivity.

The [A] polymer is preferably polyamic acid (A1) or polyimine (A2), and the polyamic acid (A1) and polyimine (A2) are more preferably those having the polymer. The structural unit (I) is represented by the above formula (2) or formula (3).

The polyamic acid (A1) is preferably a polymer represented by the above formula (2) in the above structural unit (I). Further, the polyimine (A2) is preferably a polymer represented by the above formula (3) in the above structural unit (I), and as the structural unit (I), in addition to the structural unit represented by the above formula (3), It may have a structural unit represented by the above formula (2).

The [A] polymer is preferably at least one polymer selected from the group consisting of poly-proline and polyimine, and the polyamine includes the two represented by the above formula (4) by [a] A reaction between a diamine component of an amine compound and a [b] tetracarboxylic dianhydride component, wherein the polyamidene is dehydrated and closed. Further, the [b] tetracarboxylic dianhydride component is preferably a component containing the tetracarboxylic dianhydride represented by the above formula (5). In addition, the diamine compound represented by the above formula (4) and the tetracarboxylic dianhydride represented by the above formula (5) are described in detail in the method for synthesizing the [A] polymer.

<[A] Synthesis Method of Polymer>

As a method for synthesizing the [A] polymer, a method for synthesizing the polyamic acid (A1) and the polyimine (A2) will be described in detail below, but the synthesis method of the [A] polymer in the present invention is not Limited to these synthetic methods.

[Synthesis method of polyaminic acid (A1)]

The polyaminic acid (A1) can be reacted, for example, by reacting a diamine component containing a diamine compound (the diamine compound contains a part of the structure represented by the above formula (1)) with a tetracarboxylic dianhydride component in an organic solvent. And synthesis.

(diamine compound component)

The diamine compound contained in the diamine compound component is preferably a compound represented by the above formula (4).

In the above formula (4), R ¹ and Ar ¹ have the same meanings as in the above formula (1).

, (1), R and Ar applicable to the above description of formula (4) R in the above formula and Ar ^{1 1 1 1.}

Examples of the compound represented by the above formula (4) include a compound represented by the following formula (4-1) to formula (4-8). Further, these diamine compounds may be used singly or in combination of two or more.

[Chemical 6]

Among these compounds, a diamine compound represented by the above formula (4-1) to formula (4-4) and formula (4-7) is preferable, and those of the above formula (4-1) and formula (4-7) are more preferable. The diamine compound represented by the above formula (4-1) is more preferably a diamine compound.

Further, in the synthesis of the polyamic acid (A1), other diamine compounds may be copolymerized together with the diamine compound represented by the above formula (4) as long as the effects of the present invention are not impaired.

Examples of the other diamine compound include an aliphatic diamine, an alicyclic diamine, a diaminoorganosiloxane, and an aromatic diamine other than the aromatic diamine represented by the above formula (4) (hereinafter also referred to as "others". Aromatic diamine") and the like. These other diamine compounds may be used singly or in combination of two or more.

Examples of the aliphatic diamine include m-xylylenediamine and 1,3-propanediamine. (1,3-propane diamine), tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, and the like.

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl)cyclohexane.

Examples of the diaminoorganomethoxy siloxane include 1,3-bis(3-aminopropyl)-tetramethyldioxane, and the like, and other examples described in JP-A-2010-97188 amine.

Examples of the other aromatic diamines include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'- Dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,7-diaminopurine, 4,4'- Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)anthracene, 2,2-bis[4-( 4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)diphenylamine, 4 , 4'-(meta-phenyl diisopropylidene) diphenylamine, 1,4-bis(4-aminophenoxy)benzene, 4,4'-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,N'-bis(4-aminophenyl)-benzidine ,N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl)-pyridazine, 3,5-diaminobenzene Formic acid, dodecyloxy-2,4-diaminobenzene, tetradecyloxy-2,4-diaminobenzene , pentadecyloxy-2,4-diaminobenzene, cetyloxy-2,4-diaminobenzene, octadecyloxy -2,4-diaminobenzene, dodecyloxy-2,5-diaminobenzene, tetradecyloxy-2,5-diaminobenzene, pentadecyloxy-2,5-diaminobenzene , cetyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, cholestanyyloxy-3,5-diaminobenzene, cholestene Cholesteryloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestyloxy-2,4-diaminobenzene, 3,5-di Cholesteryl aminobenzoate, cholesterol base 3,5-diaminobenzoate, lanosteryl 3,5-diaminobenzoic acid, 3,6-bis(4-aminobenzene Methoxyoxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzylideneoxy)cyclohexyl-3,5- Diaminobenzoate, 4-(4'-trifluoromethylbenzyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl) )methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-double (4-((Aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4) -heptylcyclohexyl)cyclohexane, 2,4-di Amino-N,N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine, and a diamine compound represented by the following formula.

In the above formula, R ⁴ is a divalent alkanediyl group having a carbon number of 1 to 3, ^* -O-, ^* -COO- or ^* -OCO-. Wherein ^{* is} bonded to a diaminophenyl group. r is 0 or 1. s is an integer from 0 to 2. t is an integer from 1 to 20.

Among these other diamine compounds, other aromatic diamines are preferred.

The content ratio of the diamine compound represented by the above formula (4) to the other diamine compound in the [a] diamine component is preferably 100 mol%: 0 mol% to 20 mol%: 80 mol%, more preferably 100. Mol%: 0 mol% to 50 mol%: 50 mol%.

(tetracarboxylic dianhydride component)

Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. In addition to these tetracarboxylic dianhydrides, the tetracarboxylic dianhydride described in Japanese Patent Application No. 2009-157556 can also be used. Further, these tetracarboxylic dianhydrides may be used singly or in combination of two or more.

Examples of the aliphatic tetracarboxylic dianhydride include butane tetracarboxylic dianhydride.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, and 1, 3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c] Furan-1,3-diketone, 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-tricarboxy-2-carboxyl Base norbornane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9- Dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, and the like.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, and 3,3',4,4'. -biphenyl fluorene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, Japanese Patent Patent Application 2010-97188 The tetracarboxylic dianhydride described in the above formula, the aromatic tetracarboxylic dianhydride represented by the above formula (5), and the like.

In the above formula (5), Y is a group containing an aromatic ring or an alicyclic ring. X ¹ and X ² are each independently a single bond, -O-, -S- or -NH-.

Examples of the group containing an aromatic ring represented by Y include, for example, a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms and a plurality of aromatic rings having 6 to 20 carbon atoms bonded via a single bond or a divalent organic group. Base.

Examples of the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a stretched phenyl group, an extended naphthyl group, and an extended fluorenyl group. From the viewpoint of improving the light-alignment property of the light-aligning liquid-crystal alignment agent, a phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.

The divalent organic group in the group in which the plurality of aromatic rings having 6 to 20 carbon atoms are bonded via a single bond or a divalent organic group may, for example, be a divalent hydrocarbon group having 1 to 30 carbon atoms.

Examples of the divalent hydrocarbon group having 1 to 30 carbon atoms include a divalent chain hydrocarbon group having 1 to 30 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and a divalent aromatic having 6 to 30 carbon atoms. A group such as a group of a hydrocarbon group or the like.

The above plurality of aromatic rings having a carbon number of 6 to 20 are single-bonded or divalent organic Examples of the group bonded to the group include a group in which a plurality of benzene rings are bonded via a single bond or a divalent organic group, and preferably two or three benzene rings are bonded via a single bond or a divalent organic group. The group formed is more preferably a group in which two benzene rings are bonded by a single bond.

Examples of the group containing the alicyclic ring represented by Y include a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and a plurality of alicyclic hydrocarbon groups having 6 to 20 carbon atoms bonded via a single bond or a divalent organic group. The basis of the formation.

Examples of the alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclobutyl group, a cyclopentylene group, a cyclohexylene group, a cyclooctyl group, a norbornylene group, and an adamantyl group (norbornylene). Adamantylene) and so on. Among these groups, a cyclopentyl group, a cyclohexylene group, a cyclohexyl group are more preferable, and a trans-1,4-cyclohexylene group is further more preferable.

Examples of the group in which the alicyclic hydrocarbon group having 4 to 20 carbon atoms is bonded via a single bond or a divalent organic group may, for example, be two or three of the above-exemplified alicyclic hydrocarbon groups having 4 to 20 carbon atoms. A group in which a single bond or a divalent organic group is bonded. The above two or three alicyclic hydrocarbon groups bonded via a single bond or the like may be the same group or different groups, and are preferably the same group. Preferably, two or three of the above-exemplified groups having a condensed hydrocarbon group of 4 to 20 carbon atoms bonded by a single bond are used, and more preferably two or three exocyclic hexyl groups are bonded by a single bond. Further, a trans, trans-4,4'-biased cyclohexyl group is further more preferred.

The above Y is preferably a group in which a phenyl group, an anthranyl group, a two or three benzene rings are bonded by a single bond, a cyclohexyl group, two or three exocyclic groups are bonded by a single bond. More preferably, phenyl, phenyl, trans - 1,4-cyclohexylene, trans, trans-4,4'-biased cyclohexyl.

The above X ¹ and X ^{2 are} preferably -O- or -NH-, and more preferably -O-.

The tetracarboxylic dianhydride represented by the above formula (5) is, for example, a compound represented by the following formula (5-1) to formula (5-7).

Among the aromatic tetracarboxylic dianhydrides, pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 3,3',4,4'-linked are preferred. Benzene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, aroma represented by the above formula (5) The tetracarboxylic dianhydride is more preferably pyromellitic dianhydride, and the compound represented by the above formula (5-1) to formula (5-7).

The tetracarboxylic dianhydride is preferably an aromatic tetracarboxylic dianhydride, more preferably pyromellitic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4 , 4'-biphenyl fluorene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, the above formula (5 Further, the aromatic tetracarboxylic dianhydride represented by the above formula (5-1) to the compound represented by the formula (5-7) is more preferably a pyromellitic dianhydride.

The ratio of use of the diamine component (the total of the diamine compound and the other diamine compound represented by the above formula (4)) and the tetracarboxylic dianhydride component used in the synthesis reaction of the polyamic acid (A1) is relatively The acid anhydride group of the tetracarboxylic dianhydride component is preferably from 0.2 equivalents to 2 equivalents, more preferably from 0.3 equivalents to 1.2 equivalents, per equivalent of the amino group contained in the diamine component.

The content ratio of the proline structural unit derived from the diamine component and the tetracarboxylic dianhydride component in the polyamic acid (A1) is relative to all structural units of the polyglycolic acid (A1). It is preferably from 0.1 mol% to 100 mol%, more preferably from 5 mol% to 95 mol%, still more preferably from 50 mol% to 90 mol%.

As the polytetradecanoic acid (A1) derived from the above tetracarboxylic dianhydride The content ratio of the structural unit (I) represented by the above formula (2) of the above diamine compound is preferably 50 mol% to 100 mol% based on all structural units of the polyamic acid (A1). It is more preferably 60 mol% to 100 mol%, still more preferably 80 mol% to 100 mol%.

The synthesis reaction of polyamic acid (A1) is preferably carried out in an organic solvent. The reaction temperature is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.5 to 24 hours, more preferably from 2 to 12 hours.

The organic solvent is not particularly limited as long as it is an organic solvent capable of dissolving the synthesized polyamic acid (A1), and examples thereof include an aprotic polar solvent, a phenol and a derivative thereof, an alcohol, a ketone, and an ester. Ether, halogenated hydrocarbons, hydrocarbons, and the like.

Specific examples of the organic solvents include N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, and N,N-dimethylmethyl. An aprotic polar solvent such as decylamine, dimethyl hydrazine, γ-butyrolactone, tetramethylurea or hexamethylphosphonium triamine; a phenol derivative such as m-cresol, xylenol or halogenated phenol; Alcohols such as methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether; acetone, methyl ethyl ketone, methyl Ketones such as isobutyl ketone and cyclohexanone; ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate An ester, an ester such as diethyl malonate; Diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethyl Diol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran Ether; methylene chloride, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, etc.; hexane, heptane, octane a hydrocarbon such as benzene, toluene, xylene, isoamyl propionate, isoamyl isobutyrate or diisoamyl ether.

Among these organic solvents, one or more organic solvents selected from the group (p) composed of an aprotic polar solvent, a phenol and a derivative thereof, or one or more organic selected from the group (p) is preferably used. A mixture of a solvent and one or more organic solvents selected from the group (q) consisting of an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon. In the latter case, the use ratio of the organic solvent as the group (q) is preferably 50% by mass or less based on the total of the organic solvent of the group (p) and the organic solvent of the group (q). It is more preferably 40% by mass or less, and particularly preferably 30% by mass or less.

The amount (α) of the organic solvent to be used is preferably a total (α + β) of the total amount (β) of the tetracarboxylic dianhydride component and the diamine compound component and the amount (α) of the organic solvent used. 0.1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass.

The polyaminic acid solution obtained after the reaction can be directly used in the preparation of the liquid alignment alignment agent for photoalignment, and the polyamine contained in the reaction solution can also be used. In the preparation of the liquid crystal alignment agent for photoalignment after acid separation, the isolated polylysine may be purified and used for preparation of a liquid crystal alignment agent. For example, a method in which the reaction solution is injected into a large amount of a poor solvent and the precipitate obtained is dried under reduced pressure, and the reaction solution is distilled off under reduced pressure by an evaporator or the like. The method for purifying the polyamic acid is a method in which the isolated polylysine is redissolved in an organic solvent and precipitated in a poor solvent, and the organic solvent or the like is decompressed one or more times with an evaporator. The method of the step of distilling off.

In the synthesis of the above polyamic acid, in addition to the above tetracarboxylic dianhydride and the diamine compound, a terminal-modified polymer may be synthesized by using an appropriate molecular weight modifier. By forming the terminal-modified polymer, the coating property (printability) of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight modifier include an acid monoanhydride, a monoamine compound, and a monoisocyanate compound.

Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride, and the like.

Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine.

The monoisocyanate compound may, for example, be phenyl isocyanate or naphthyl isocyanate.

As the use ratio of the above molecular weight modifier, relative to the use The total amount of the tetracarboxylic dianhydride and the diamine is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less.

[Synthesis method of polyimine (A2)]

The polyimine (A2) may be a complete quinone imide formed by dehydration ring closure of the proline structure of polyglycine (A1) as a precursor thereof, or may be only a part of the structure of the proline A dehydration ring closure, a partial ruthenium imide of a proline structure and a quinone ring structure. The polyamidimide (A2) preferably has a ruthenium iodide ratio of 30% or more, more preferably 50% to 99%, and still more preferably 65% to 99%. The ruthenium imidization ratio is a ratio of the number of quinone ring structures to the total number of guanidine structures and the number of quinone ring structures of the polyimine. Here, a part of the quinone ring may also be an isoindole ring.

Polyimine (A2) can be obtained by subjecting polylysine (A1) synthesized as described above to dehydration ring closure and hydrazine imidization.

The dehydration ring closure of the polyaminic acid (A1) is preferably carried out by heating the polyaminic acid (A1) or by dissolving the polyaminic acid in an organic solvent, and adding a dehydrating agent and a dehydration ring-closing catalyst to the solution. It is carried out as needed by heating. Among them, the latter method is preferably used.

In the method of adding a dehydrating agent and a dehydration ring-closure catalyst to the solution of the above polyamic acid (A1), an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 with respect to the proline structure of the polyaminic acid (A1). Moer ~ 20 Mo. As the dehydration ring-closing catalyst, for example, a tertiary amine such as pyridine, collidine, lutidine or triethylamine can be used. The amount of use as the dehydration ring-closure catalyst is preferably 0.01 mol to 10 mol per mol of the dehydrating agent used. The organic solvent used for the dehydration ring-closure reaction is exemplified as the organic solvent used for the synthesis of the polyamic acid (A1). The reaction temperature of the dehydration ring closure reaction is preferably from 0 ° C to 180 ° C, more preferably from 10 ° C to 150 ° C. The reaction time is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours.

The reaction solution containing the obtained polyimine (A2) can be directly supplied to the liquid alignment alignment agent for photoalignment, or the dehydration agent and the dehydration ring closure catalyst can be removed from the reaction solution and supplied to the liquid alignment liquid crystal. The preparation of the alignment agent may be carried out after the segregation of the polyimine (A2) to the photo-alignment liquid crystal alignment agent, or the isolated polyimine (A2) may be purified and supplied to the light. Modulation of alignment liquid crystal alignment agent. These purification operations can be carried out in accordance with a known method.

The polyaminic acid (A1) and the polyindenine (A2) obtained as described above are preferably 20 mPa when formed into a solution having a concentration of 10% by mass. s~800 mPa. The solution viscosity of s, more preferably 30 mPa. s~500 mPa. The solution viscosity of s. The solution viscosity (mPa.s) of the above [A] polymer is a concentration of 10% by mass prepared for a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using these polymers. Polymer solution using an E-type rotational viscometer at 25 ° C The value measured.

<Other ingredients>

The liquid alignment alignment agent for photoalignment of the present invention contains the [A] polymer as an essential component, but may contain other components as needed. Examples of the other component include a polymer other than the [A] polymer, a compound having at least one epoxy group in the molecule (hereinafter also referred to as "epoxy compound"), a functional decane compound, and the like.

(other polymers)

The other polymers described above can be used to improve solution properties and electrical properties. The other polymer is a polymer other than the polymer [A] such as the polyamic acid (A1) or the polyimine (A2), and examples thereof include polyamines having a structure represented by the above formula (1). An acid (hereinafter also referred to as "other poly-proline"), a polyimine which is obtained by dehydration ring closure of the above other polylysine (hereinafter also referred to as "other polyimine"), and does not have the above formula (1) Polyurethane ester, polyester (hereinafter also referred to as "other polyester"), polyamine, polyoxyalkylene, cellulose derivative, polyoxymethylene, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly(meth)acrylate, and the like. Among these, other polyamines, other polyimines, and other polyesters are preferable, and other polyamines and other polyimines are more preferable, and other polyamines are still more preferable.

The tetracarboxylic dianhydride used for the synthesis of the above other polyaminic acid or other polyimine is exemplified as a tetracarboxylic dianhydride for synthesizing the polyamic acid (A1) used in the present invention. The same tetracarboxylic dianhydride as described above is preferably selected from the group consisting of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, Pyromellitic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo At least one of the group consisting of -3-furyl)-naphtho[1,2-c]furan-1,3-dione.

As the diamine for synthesizing the above other polyaminic acid or other polyimine, at least one selected from the group consisting of polyamines (A1) which can also be used in the synthesis of the present invention can be used. The diamine exemplified as the other diamine compound used. Preferably, the diamines are selected from the group consisting of 4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, cholestyloxy-2,4 At least one selected from the group consisting of diaminobenzene, 3,5-diaminobenzoic acid, and 1,4-bis-(4-aminophenyl)-pyridazine.

The use ratio of the other polymer is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less based on the [A] polymer.

(epoxy compound)

Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and neopentyl glycol condensed water. Glycerol ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetrahydration Glyceryl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-bi-drink Glyceryl-cyclohexylamine or the like is preferred as the epoxy compound.

The blending ratio of the epoxy compounds is preferably 40 parts by mass or less, and more preferably 0.1 parts by mass to 30 parts by mass, based on 100 parts by mass of the total of the polymer.

(functional decane compound)

Examples of the functional decane compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-aminopropyltriethoxydecane. N-(2-Aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, 3-ureidopropyltrimethyl Oxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl-3-aminopropyltriethoxydecane , N-triethoxydecylpropyltriethylethylamine, N-trimethoxydecylpropyltriethylamine, 10-trimethoxydecyl-1,4,7-triazole Triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diazadecyl acetate, 9 -trimethoxydecyl-3,6-diazadecyl acetate, 9-triethoxydecyl-3,6-diazadecyl acetate, 9-trimethoxydecyl- Methyl 3,6-diazepine, methyl 9-triethoxydecyl-3,6-diazepine, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltriethoxydecane, glycidyloxy Methyltrimethoxydecane, glycidoxymethyltriethoxydecane, 2-glycidoxyethyltrimethoxydecane, 2-glycidoxyethyltriethoxydecane, 3-shrinkage Glycidoxypropyltrimethoxysulfonium Alkane, 3-glycidoxypropyltriethoxydecane, and the like.

The blending ratio of the functional decane compound is preferably 2 parts by mass or less, and more preferably 0.02 parts by mass to 0.2 parts by mass, based on 100 parts by mass of the total of the polymer.

<Preparation of liquid crystal alignment agent for light alignment>

In the liquid-aligning liquid-aligning agent of the present invention, the [A] polymer such as polyacrylic acid (A1) or polyimine (A2) and optionally other components are preferably dissolved in an organic solvent. And constitute.

Examples of the organic solvent used in the liquid alignment alignment agent for photoalignment of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactone, and N,N-dimethylformamide. , N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, B Ethyl oxypropionate, 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, B Glycol ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethyl Glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, and the like. These organic solvents may be used singly or in combination of two or more.

The solid content concentration in the liquid-aligning liquid-aligning agent of the present invention (the ratio of the total mass of the components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) can be appropriately selected in consideration of viscosity, volatility, and the like. It is preferably in the range of 1% by mass to 10% by mass. That is, this The liquid crystal alignment agent for photoalignment can be applied to the surface of the substrate as described later, and is preferably heated to form a coating film as a liquid crystal alignment film or a coating film which is a liquid crystal alignment film, and has a solid content of less than 1% by mass. In the case where the film thickness of the coating film is too small, a satisfactory liquid crystal alignment film cannot be obtained. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes too large to obtain a good film. In the liquid crystal alignment film, the viscosity of the liquid alignment alignment agent increases, and the coating property is deteriorated.

A particularly preferable range of the solid content concentration differs depending on the method used when the photo-alignment liquid crystal alignment agent is applied onto the substrate. For example, in the case of using the spin coating method, the solid content concentration is particularly preferably in the range of 1.5% by mass to 4.5% by mass. In the case of using the printing method, it is particularly preferable to set the solid content to a range of 3% by mass to 9% by mass, thereby setting the solution viscosity to 12 mPa. s~50 mPa. The scope of s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% by mass to 5% by mass, thereby setting the solution viscosity to 3 mPa. s~15 mPa. The scope of s.

The temperature at which the liquid alignment alignment agent for photoalignment of the present invention is prepared is preferably 10 to 50 ° C, and more preferably 20 to 30 ° C.

<Liquid alignment film>

The liquid crystal alignment film of the present invention is formed by the liquid alignment alignment agent. Therefore, in the forming step, excellent liquid crystal alignment ability can be imparted by using radiation of a low irradiation amount. In addition, there is no need for irradiation of radiation and heating after irradiation, so production efficiency is good and manufacturing cost is low. It has also been cut.

<Method of Forming Liquid Crystal Alignment Film>

The liquid alignment alignment agent for photoalignment of the present invention can be widely used as a material for a liquid alignment film for photoalignment. Further, it can be suitably used for forming a liquid crystal alignment film used in a liquid crystal display element: a liquid crystal display element having a TN type or STN type liquid crystal cell or a liquid crystal display element having a transverse electric field type such as an IPS type or FFS type liquid crystal cell . When the liquid crystal alignment agent for photoalignment of the present invention is used in a liquid crystal display device having an IPS type or FFS type liquid crystal cell, it is preferably used as long as the effect of the present invention is maximized.

The method for forming a liquid crystal alignment film of the present invention comprises: (1) a step of forming a coating film on a substrate by using the liquid alignment alignment agent for photoalignment of the present invention (hereinafter also referred to as "step (1)"); and (2) The step of irradiating the coating film with light to form a liquid crystal alignment film (hereinafter also referred to as "step (2)").

Hereinafter, each step will be described in detail.

[step 1)]

When the liquid alignment alignment agent for photoalignment of the present invention is applied to a liquid crystal display device having a TN type or STN type liquid crystal cell, two substrates each having a patterned transparent conductive film are used as a pair. The photoalignment liquid crystal alignment agent of the present invention is applied to the surface of each of the transparent conductive films to form a coating film. On the other hand, when the liquid alignment alignment agent for photoalignment of the present invention is applied to a liquid crystal display device having an IPS type or FFS type liquid crystal cell, a transparent conductive film or a transparent conductive film may be provided on one side. The substrate on which the metal film is patterned into a comb-shaped electrode is paired with the opposite substrate on which the electrode is not provided, and the alignment of the optical alignment liquid of the present invention is applied to one surface of the comb-shaped electrode and the opposite surface of the opposite substrate. A coating film is formed by the agent.

In any case, the substrate may be, for example, a glass such as float glass or soda glass, such as polyethylene terephthalate, polybutylene terephthalate, polyether oxime or polycarbonate. Plastic transparent substrate, etc. As the transparent conductive film, for example, an ITO film containing In ₂ O ₃ —SnO ₂ , a NESA (registered trademark) film containing SnO ₂ , or the like can be used. As the metal film, for example, a film containing a metal such as chromium can be used. For the patterning of the transparent conductive film and the metal film, for example, a method of forming a pattern by a photolithography method, a sputtering method, or the like after forming a transparent conductive film having no pattern, and a pattern having a desired pattern when forming a transparent conductive film can be used. The method of the mask, etc.

In order to improve the adhesion between the substrate, the conductive film, and the electrode and the coating film when the liquid alignment alignment agent is applied onto the substrate, a functional decane compound, titanate, or the like may be applied to the substrate and the electrode in advance. .

The application of the liquid alignment alignment agent on the substrate can be preferably carried out by an appropriate coating method such as an offset printing method, a spin coating method, a roll coating method or an inkjet printing method, and secondly, the coated surface is preheated (prebaked). Then, simmering (post-baking) is carried out to form a coating film. The prebaking conditions are, for example, from 40 ° C to 120 ° C for 0.1 minutes to 5 minutes, and the post-baking conditions are preferably from 120 ° C to 300 ° C, more preferably from 150 ° C to 250 ° C. The progress is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. The film thickness of the coating film after post-baking is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

[Step (2)]

The liquid crystal alignment ability is imparted by irradiating the coating film formed as described above with the radiation of the polarized light. Here, as the radiation, for example, ultraviolet rays and visible rays including light having a wavelength of 150 nm to 800 nm can be used, but ultraviolet rays containing light having a wavelength of 200 nm to 400 nm are preferable.

As the light source to be used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an Hg-Xe lamp, an excimer laser or the like can be used. The ultraviolet light in the above preferred wavelength region can be obtained by a method in which the above-described light source is used in combination with, for example, a filter, a diffraction grating, or the like.

When the liquid alignment alignment agent for photoalignment of the present invention is used, when it is usually required to be irradiated with ultraviolet rays of 10,000 J/m ² or more, a good liquid crystal alignment ability can be imparted even at 8,000 J/m ² , which contributes to improvement. The productivity of liquid crystal display elements and the reduction of manufacturing costs.

<Liquid crystal display element>

The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed using the liquid alignment alignment agent. The above liquid crystal alignment film can obtain liquid crystal alignment ability with less radiation exposure than before, and thus the liquid crystal display element including the above liquid crystal alignment film can be manufactured at a lower cost than before. The liquid crystal display element of the present invention can be produced, for example, as follows.

A pair of substrates on which a liquid crystal alignment film is formed as described above is prepared, and a liquid crystal cell having a liquid crystal sandwiched between the pair of substrates is manufactured. When manufacturing a liquid crystal cell, the following two methods are mentioned, for example.

The first method is a method known from the previous one. The liquid crystal alignment film is opposed to each other so that the two substrates are opposed to each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are bonded together using a sealant, and the cells are divided by the substrate surface and the sealant. After the filling liquid crystal is injected into the gap, the injection hole is sealed, whereby the liquid crystal cell can be manufactured.

The second method is called the One Drop Fill (ODF) method. For example, an ultraviolet curable sealing material is applied to a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is further dropped on the liquid crystal alignment film surface, and then the liquid crystal alignment film is opposed to each other. The other substrate is bonded, and the entire surface of the substrate is irradiated with ultraviolet light to harden the sealing agent, whereby the liquid crystal cell can be manufactured.

In the case of using any method, it is preferred to heat the liquid crystal cell next until the liquid crystal used becomes a temperature of the isotropic phase, and then slowly cool to room temperature, thereby removing the flow alignment at the time of liquid crystal filling.

Next, the liquid crystal display element of the present invention can be obtained by laminating a polarizing plate on the outer surface of the liquid crystal cell. Here, the desired liquid crystal display element can be obtained by appropriately adjusting the angle formed by the polarization direction of the linearly polarized radiation irradiated on the two substrates on which the liquid crystal alignment film is formed and the angle between each of the substrates and the polarizing plate.

As the above sealant, for example, alumina containing as a spacer can be used. Epoxy resin of ball and hardener.

For the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. A liquid crystal having positive dielectric anisotropy of a nematic liquid crystal is preferably used, and for example, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, or a biphenyl cyclohexane liquid crystal can be used. , pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubic liquid crystal, and the like. Further, in the above liquid crystal, for example, a cholesteric liquid crystal such as cholesteryl alcohol, cholesteryl phthalate or cholesteryl carbonate may be further added as the above-mentioned liquid crystal; as the trade names "C-15" and "CB-15" (a chiral agent commercially available from Merck & Co., Ltd.); a ferroelectric liquid crystal such as p-methoxybenzylidene-p-amino-2-methylbutylcinnamate.

The polarizing plate used for the outer side of the liquid crystal cell may be a polarizing film called "H film" sandwiched between a cellulose acetate protective film (the H film is formed by absorbing iodine on one side of the polyvinyl alcohol. A polarizing film made of a polarizing film or a polarizing plate including the H film itself. The liquid crystal display element of the present invention produced as described above is excellent in performances such as display characteristics and electrical characteristics.

[Example]

Hereinafter, the present invention will be more specifically illustrated by the examples, but the present invention is not limited by the examples.

<Synthesis of polyaminic acid (A1) and polyimine (A2)>

[Synthesis Example 1]

4.66 g of pyromellitic dianhydride and 2.84 g of the diamine compound represented by the following formula (4-1) were dissolved in 42.5 g of N-methyl-2-pyrrolidone, and allowed to react at room temperature for 4 hours. Obtained a solids concentration of 15% and a viscosity of 246 mPa. A solution containing poly-proline (P-1).

[Synthesis Example 2]

6.40 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 3.60 g of the diamine represented by the above formula (4-1) were dissolved in N-methyl-2-pyrrolidone 56.7 g at 60 ° C The reaction was allowed to proceed for 4 hours to obtain a viscosity of 240 mPa. a solution of poly-proline in s. To the obtained polyphthalic acid-containing solution, 33.3 g of γ-butyrolactone, 11.30 g of pyridine, and 8.75 g of acetic anhydride were added, and the mixture was reacted at 110 ° C for 4 hours. After completion of the reaction, the reaction solution was concentrated to 80 g, and 100 g of γ-butyrolactone was added thereto, and concentrated again to 80 g to obtain a polythenimine having a solid content of 12.1% and having a quinone imidization ratio of 92% ( Solution of P-2).

[Synthesis Example 3]

5.12 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1.25 g of pyromellitic dianhydride, and 3.63 g of diamine represented by the above formula (4-1) were dissolved in N-methyl-2. - Pyrrolidone 56.7 g, reacted at 60 ° C for 4 hours to obtain a viscosity of 250 mPa. a solution of poly-proline in s. Adding γ-butyrolactone 33.3 to the obtained solution containing poly-proline g, pyridine 4.52 g and acetic anhydride 5.83 g were reacted at 110 ° C for 4 hours. After the end of the reaction, the reaction solution was concentrated to 80 g, 100 g of γ-butyrolactone was added, and concentrated again to 80 g to obtain a polythenimine having a solid content of 12.0% and having a ruthenium iodide ratio of 81%. (P-3) solution.

[Synthesis Example 4]

12.6 g of the acid anhydride represented by the following formula (5-1) and 3.42 g of the diamine represented by the above formula (4-1) were dissolved in N-methyl-2-pyrrolidone 90.7 g, and allowed to make it at room temperature. After reacting for 4 hours, a solid concentration of 15.0% and a viscosity of 978 mPa were obtained. a solution containing poly-proline (P-4).

[Synthesis Example 5]

16.2 g of the acid anhydride represented by the following formula (5-3) and 3.78 g of the diamine represented by the above formula (4-1) were dissolved in 180 g of N-methyl-2-pyrrolidone, and the mixture was allowed to stand at 60 ° C at 60 ° C. After reacting for 4 hours, a solid concentration of 10.0% and a viscosity of 508 mPa were obtained. A solution containing poly-proline (P-5).

[11]

[Synthesis Example 6]

8.7 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 6.3 g of the diamine compound represented by the following formula (4-7) were dissolved in N-methyl-2-pyrrolidone 85 g, The reaction was allowed to proceed at room temperature for 4 hours to obtain a solid concentration of 15% and a viscosity of 305 mPa. A solution containing poly-proline (P-6).

[Comparative Synthesis Example 1]

6.50 g of pyromellitic dianhydride and 5.50 g of 4,4'-diaminodiphenylmethane were dissolved in 68.0 g of N-methyl-2-pyrrolidone, and allowed to react at room temperature for 4 hours to obtain a solid matter. The concentration is 15.0% and the viscosity is 238 mPa. a solution containing poly-proline (R-1).

[Comparative Synthesis Example 2]

13.1 g of poly(2-hydroxyethyl methacrylate) was dissolved in 50 mL of N-methyl-2-pyrrolidone, and after cooling to room temperature, 10 mL of pyridine was added. Cinnamon chlorochloride 17.0 g was added thereto and stirred for 8 hours. The reaction mixture was diluted with N-methyl-2-pyrrolidone, added to methanol, and the precipitate was sufficiently washed with water and dried to obtain A solution containing the polymer (R-2).

<Preparation of liquid crystal alignment agent for light alignment>

[Example 1]

Adding N-methyl-2-pyrrolidone (NMP) and butyl solution to the above solution containing polylysine (P-1) (in terms of the solid content of polylysine equivalent to 100 parts by mass) To the butyl cellosolve (BC), 20 parts by mass of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane as an epoxy compound is further added, and the mixture is sufficiently stirred. A solution having a solvent composition of NMP: BC = 60: 40 (mass ratio) and a solid content of 2.5% by mass was prepared. This solution was filtered using a screening program having a pore size of 1 μm to thereby prepare a liquid crystal alignment agent (A-1).

[Example 2 to Example 6, Comparative Example 1 to Comparative Example 2]

Instead of containing polyfluorene, a solution containing polylysine, polyimine or polymer (P-2)~(P-6), (R-1)~(R-2) as described in Table 1 was used. In the same manner as in Example 1, except that the solution of the amino acid (P-1) was used to prepare a liquid crystal alignment agent (A-2) to a liquid crystal alignment agent (A-6), and a liquid crystal alignment agent (B-1) to liquid crystal alignment. Agent (B-2).

<Manufacture of liquid crystal display element>

Each of the liquid crystal alignment agents prepared above was applied to a transparent electrode surface of a glass substrate having a transparent electrode containing an ITO film so as to have a film thickness of 0.1 μm, and dried at 200 ° C for 1 hour. Coating film. Using a Hg-Xe lamp, the surface of the coating film was irradiated with polarized ultraviolet rays containing a bright line of 254 nm from the normal direction of the substrate at respective irradiation amounts of 8,000 J/m ² , 10,000 J/m ² , or 20,000 J/m ² . Forming a liquid crystal alignment film. Next, in the pair of substrates subjected to the light irradiation treatment, the liquid crystal injection port was left at the edge of the surface on which the liquid crystal alignment film was formed, and the epoxy resin adhesive having an alumina ball having a diameter of 5.5 μm was screen-printed and applied. The substrate was superposed by overlapping the projection direction of the polarizing axis on the substrate surface when the light was irradiated, and the adhesive was thermally bonded at 150 ° C for 1 hour. Next, a liquid crystal injection port was used to charge the liquid crystal (manufactured by Merck & Co., Ltd., MLC-7028) between a pair of substrates, and then the liquid crystal injection port was sealed with an epoxy-based adhesive. Further, in order to remove the flow alignment at the time of liquid crystal injection, it was heated at 150 ° C and then slowly cooled to room temperature. Next, a polarizing plate was bonded to both surfaces of the outer side of the substrate to fabricate a liquid crystal display element.

With respect to each of the above liquid crystal display elements, the following evaluation was performed. The results are shown in Table 1.

<evaluation>

[Liquid alignment]

The presence or absence of an abnormal region when the voltage is turned on/off (applied/released) in the liquid crystal display device is observed with a polarizing microscope, and the case where there is no abnormal region is judged as "good", and the case where one abnormal region exists is determined as "poor" ".

[Voltage retention rate]

A liquid crystal display element produced by irradiating a polarized ultraviolet ray of 8,000 J/m ² was applied with a voltage of 5 V at an interval of 167 msec after application of 60 microseconds, and then the voltage holding ratio after 167 msec from the release of the application was measured. The measurement apparatus used was VHR-1 manufactured by Toyo Corporation. The measured value (%) of the voltage holding ratio is shown in Table 1. The case where the voltage holding ratio is 90% or more can be evaluated as "good", and the other cases can be evaluated as "poor".

[afterimage characteristics (burnt characteristics)]

As a substrate, a metal substrate including a chromium-containing two-system metal electrode, an electrode A (101), and an electrode B (102) on a single surface as shown in FIG. 1 and a pair of electrodes not provided with an electrode are provided. A liquid crystal display device of a transverse electric field type is produced in the same manner as the above-described production of the liquid crystal display element, except that the glass substrate is used as a pair. This lateral electric field type liquid crystal display element was placed in an environment of 25 ° C and 1 atm, and a voltage of 3.5 V of an alternating current voltage of 3.5 V and a direct current voltage of 5 V was applied to the electrode A without applying a voltage to the electrode B. Shortly after this, a voltage of 4 V was applied to both of the electrode A and the electrode B. The time from the time when the voltage of the alternating current of 4 V was applied to the two electrodes was measured, and it was impossible to visually confirm the time when the light transmittance of the electrode A and the electrode B was inferior. The afterimage characteristic in the case where the time is less than 100 seconds is evaluated as "good", and the afterimage characteristic in the case where the time is 100 seconds or more and less than 150 seconds is evaluated as "fair", and the time exceeds 150 seconds. The afterimage characteristics of the case were evaluated as "poor".

As shown in Table 1, the liquid crystal alignment agent containing the polymer having the specific structure represented by the above formula (1) in the main chain has high sensitivity to radiation, and even if it is a low irradiation amount of 8,000 J/m ² , the obtained result is included. The liquid crystal alignment property of the liquid crystal display element of the liquid crystal alignment film also becomes good. Moreover, the voltage holding ratio is also good. On the other hand, in Comparative Example 1, even when an abnormal region was observed at a high irradiation amount of 20,000 J/m ² , the liquid crystal alignment property was poor. According to the above, the liquid crystal alignment agent for photoalignment of the present invention is excellent in radiation sensitivity, and a liquid crystal alignment film having excellent liquid crystal alignment property can be formed by radiation irradiation with a low irradiation amount. Further, it is understood that the liquid crystal display element including the liquid crystal alignment film of the present invention has excellent electrical characteristics and afterimage characteristics.

[Industrial availability]

The liquid alignment alignment agent for photoalignment of the present invention has high radiation sensitivity and can be formed with excellent liquid crystal distribution by radiation irradiation with a low irradiation amount. The directional liquid crystal alignment film is therefore excellent in production efficiency and can reduce production costs. In addition, the liquid crystal display element including the liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention is excellent in electrical properties and afterimage characteristics. Therefore, the liquid alignment alignment agent for liquid alignment, the liquid crystal alignment film, the method for forming the liquid crystal alignment film, and the liquid crystal display element can be suitably used for liquid crystal display elements such as IPS type and FFS type.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

101‧‧‧electrode A

102‧‧‧Electrode B

FIG. 1 is an explanatory view showing an electrode pattern of a conductive film in a substrate having a comb-shaped conductive film used in Examples and Comparative Examples when the afterimage characteristics are evaluated.

101‧‧‧electrode A

102‧‧‧Electrode B

Claims (8)

A liquid crystal alignment agent for photo-alignment comprising: [A] a polymer having a structural unit (I) having a structure represented by the following formula (1), In the formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms; Ar ¹ is a group containing an aromatic ring; ^* represents a hydrogen atom or is bonded to Other parts on the base. The liquid alignment alignment agent for photoalignment according to claim 1, wherein the [A] polymer is polyacrylic acid or polyimine. The liquid crystal alignment agent for photoalignment according to claim 2, wherein the structural unit (I) is represented by the following formula (2) or formula (3): In the formulae (2) and (3), R ¹ and Ar ¹ have the same meanings as in the above formula (1); and R ² and R ³ each independently represent a tetravalent organic group. The liquid alignment alignment agent for photoalignment according to claim 2, wherein the [A] polymer is at least one polymer selected from the group consisting of polyproline and polyimine. The polyaminic acid is obtained by reacting [a] a diamine component of a diamine compound represented by the following formula (4) with a [b] tetracarboxylic dianhydride component, which is The polylysine is dehydrated and closed: In the formula (4), R ¹ and Ar ¹ have the same meanings as in the above formula (1). The liquid crystal alignment agent for photoalignment according to claim 4, wherein the [b]tetracarboxylic dianhydride component contains at least a tetracarboxylic dianhydride represented by the following formula (5): In the formula (5), Y is a group containing an aromatic ring or an alicyclic ring; and X ¹ and X ² are each independently a single bond, -O-, -S- or -NH-. A method of forming a liquid crystal alignment film, comprising: (1) a step of forming a coating film on a substrate by using a liquid alignment agent for photoalignment according to any one of claims 1 to 5; (2) A step of forming a liquid crystal alignment film by irradiating the coating film with light. A liquid crystal alignment film which is formed by using a liquid alignment agent for photoalignment according to any one of claims 1 to 5. A liquid crystal display element comprising the liquid crystal alignment film according to item 7 of the patent application.