TW201443157A - Liquid crystal aligning agent and method for producing liquid crystal aligning agent, liquid crystal aligning film, liquid crystal display element, method for producing liquid crystal aligning film, retardation film and method for producing retardation - Google Patents

Abstract

The invention provides a liquid crystal aligning agent, which can adequately dissolve a polymer, and may form a liquid crystal aligning film by heating at a lower temperature. The liquid crystal aligning agent of the invention contains: at least one polymer (A) selected from a group consisted of a polyamic acid, a polyimide, a polyamic acid ester and a polyorganosiloxane; and a solvent including a compound (p1) represented by Formula (1) below. (In Formula (1), R1 to R4 respectively and independently is a linear or branched hydrocarbon group having a carbon number from 1 to 6, or a group having at least one selected from -O-, -COO- and -OCO- between a C-C bonding of the hydrocarbon group.)

Description

Method for producing liquid crystal alignment agent and liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element, method for producing liquid crystal alignment film, retardation film, and method for producing retardation film

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal display element, a method for producing a liquid crystal alignment film, a retardation film, and a method for producing a retardation film, and more particularly relates to a polyimine or A liquid crystal alignment agent or the like which can be sufficiently dissolved by polyacrylic acid and can form a liquid crystal alignment film by heating at a relatively low temperature.

The liquid crystal display element is formed by arranging a substrate for a liquid crystal display element in which a liquid crystal alignment film is formed on a surface of a substrate on which a transparent conductive film is formed, and sealing the liquid crystal molecules between the pair of substrates. The liquid crystal display element is known as a so-called twisted nematic (TN) type element in which the long axis of liquid crystal molecules is continuously twisted by 90° from one substrate to another. In addition, We are developing: Super Twisted Nematic (STN) type components that can achieve higher contrast than TN type components, and In-Plane Switching (IPS) type elements with less viewing angle dependence, and less viewing angle dependence In the alignment of the liquid crystal, a vertical alignment (VA) type liquid crystal display element which does not require rubbing treatment, has an optically accommodating Bend (OCB) type liquid crystal display element which has few viewing angle dependence and high speed response of an image screen.

The liquid crystal alignment film used in the liquid crystal display element is, for example, as disclosed in Patent Document 1 to Patent Document 3, by dissolving polyimine or polylysine in 1-methyl-2-pyrrolidone or γ-butyl. A liquid crystal alignment agent obtained by using a solvent such as a lactone is applied onto a substrate and then heated to form a liquid crystal alignment agent. By using polyimine or polyglycolic acid as a liquid crystal alignment agent, a liquid crystal alignment film excellent in heat resistance, affinity with liquid crystal, mechanical strength, and the like can be obtained.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 9-241646

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2001-305549

[Patent Document 3] Japanese Patent Laid-Open No. Hei 9-278724

Here, in the case where a polyimine or polylysine or the like is dissolved to prepare a liquid crystal alignment agent, as described above, it is necessary to use 1-methyl-2-pyrrolidone or γ-butyrolactone. However, it is considered that when such a solvent is used, there is a case where a liquid crystal alignment agent is applied onto a substrate to form a liquid crystal alignment film.

Specifically, 1-methyl-2-pyrrolidone or γ-butyrolactone or the like is a solvent having a high boiling point (for example, 200 ° C), and in the case of using such a high boiling point solvent, it is necessary to form a liquid crystal alignment film at a high temperature. Heat it down.

Further, a liquid crystal alignment film is formed on the substrate on which the color filter is formed. For example, when a radiation-sensitive composition containing a dye is used as a color filter, since the dye is not high in heat resistance, if heating is performed at a high temperature when the liquid crystal alignment film is formed, there is a band for the color filter. Concerns about adverse effects.

Further, for example, in the case where heating at a high temperature is required when forming the liquid crystal alignment film, the total amount of heat in the manufacturing process is correspondingly increased, resulting in a corresponding increase in the amount of carbon dioxide discharged.

A main object of the present invention is to provide a liquid crystal alignment agent capable of sufficiently dissolving a polymer such as polyimine or polylysine and forming a liquid crystal alignment film by heating at a relatively low temperature.

The present inventors have conducted active research in order to accomplish the problems of the prior art as described above, and as a result, have found that the above problems can be solved by using a specific compound as at least a part of a solvent, and the present invention has been completed. Specifically, the following liquid crystal alignment agent is provided by the present invention.

An aspect of the present invention provides a liquid crystal alignment agent comprising: at least one polymer selected from the group consisting of polyglycolic acid, polyamidiamine, polyphthalate, and polyorganosiloxane. A); and a solvent containing the compound (p1) represented by the following formula (1).

[Chemical 1]

(In the formula (1), R ¹ to R ⁴ are each independently a linear or branched hydrocarbon group having 1 to 6 carbon atoms or a group selected from -O-, -COO- and between CC bonds of the hydrocarbon group; a base of at least one of -OCO-.)

By using the compound (p1) as at least a part of the solvent of the liquid crystal alignment agent, it is possible to sufficiently dissolve the polyimine or polylysine, and to form a liquid crystal alignment film by heating at a relatively low temperature.

The liquid crystal alignment agent of the present invention is a polymer component comprising at least one polymer (A) selected from the group consisting of polylysine, polyamidiamine, polyphthalate, and polyorganosiloxane. Further, the polymer (A) is dissolved in a solvent. Hereinafter, the liquid crystal alignment agent will be described.

<polylysine>

The polyproline of the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine.

[tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid of the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. As a specific example of these tetracarboxylic dianhydrides,

Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and the like; and the alicyclic tetracarboxylic dianhydride may, for example, be 1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo- 3-furyl)-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-dione, 3-oxabicyclo[3.2.1]octane-2,4-di Keto-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclo Hexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxyl Bicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetra Ketone, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, cyclopentanoic acid dianhydride, cyclohexanetetracarboxylic dianhydride, etc.; aromatic For example, the tetracarboxylic dianhydride described in JP-A-2010-97188 can be used as the tetracarboxylic dianhydride. Further, the tetracarboxylic dianhydride may be used alone or in combination of two or more.

The tetracarboxylic dianhydride used for the synthesis preferably contains an alicyclic tetracarboxylic dianhydride from the viewpoints of transparency, solubility in a solvent, and the like. Further, the alicyclic tetracarboxylic dianhydride preferably contains at least one selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 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-dione, 2,4,6,8-tetracarboxybicyclo[3.3. 0] Octane-2:4,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, cyclopentanoic acid The dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, particularly preferably comprising a group selected from the group consisting of the following compounds At least one of: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, Bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, cyclopentanoic acid dianhydride, and 1,2,3,4-cyclobutane tetracarboxylic acid Acid dianhydride.

Included from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, and At least one of the groups consisting of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as the tetracarboxylic dianhydride, relative to the tetracarboxylic acid used to synthesize polyglycine The total amount of these compounds is preferably 10 mol% or more, and more preferably 20 mol% to 100 mol%, based on the total amount of the dianhydride.

[diamine]

Examples of the diamine for synthesizing the poly-proline of the present invention include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, a diamine organic decane, and the like. Specific examples of the diamine include aliphatic m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. And the alicyclic diamine may, for example, be 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane Examples of the aromatic diamine include p-phenylenediamine and 4,4'-diaminodiphenylmethane. 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis ( Trifluoromethyl)-4,4'-diaminobiphenyl, 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-phenylenediphenylene)diphenylamine, 4,4'-(inter)phenylisopropylene 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)-piperazine, 1-(4-amino group Phenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3 ,3-trimethyl-1H-indol-6-amine, 3,5-diaminobenzoic acid, cholesteryloxy-3,5 -diaminobenzene, cholestyloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestyloxy-2,4-di Aminobenzene, cholesteryl 3,5-diaminobenzoic acid, cholesteryl 3,5-diaminobenzoic acid, lanostino 3,5-diaminobenzoic acid, 3 ,6-bis(4-aminobenzimidyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzene Methoxyoxy)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)benzene) 4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4- ((Aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-amino Benzyl A compound represented by an amine, a 3-aminobenzylamine or a 2-(2,4-diaminophenoxy)ethyl methacrylate, and the like; and a diamine-based organodecane, for example, 1,3 - Bis(3-aminopropyl)-tetramethyldioxane or the like; in addition to the above, a diamine described in JP-A-2010-97188 can also be used. Further, these diamines may be used alone or in combination of two or more.

The diamine for synthesizing the poly-proline of the present invention is particularly preferably a compound represented by the following formula (d-1), a compound represented by the following formula (d-2), and the following formula (d). -3) At least one diamine (hereinafter also referred to as "specific diamine") in the group consisting of the compound represented by the following formula (d-4) and the compound represented by the following formula (d-4) is synthesized.

(In the formula (d-1), X ¹ and X ² are each independently a single bond, -O-, -S-, -OCO- or -COO-, and Y ¹ is an oxygen atom or a sulfur atom, R ¹ and R ^{2 is} independently an alkanediyl group having 1 to 3 carbon atoms; n1 is 0 or 1, and in the case of n1=0, n2 and n3 are integers satisfying n2+n3=2, in the case of n1=1, N2=n3=1; in the formula (d-2), X ³ is a single bond, -O- or -S-, and m1 is an integer of 0 to 3; in the case of m1=0, m2 is 1 to 12 In the case of m1 being an integer of 1 to 3, m2=2; in the formula (d-3), R ³ is a linear or branched monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ⁴ is hydrogen. Atom or a linear or branched monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group; in the formula (d-4), X ⁴ and X ⁵ are each independently The ground is a single bond, -O-, -COO- or -OCO-, R ⁷ is an alkanediyl group having 1 to 3 carbon atoms; a is 0 or 1, b is an integer of 0 to 2, and c is 1 to 20 An integer, k is 0 or 1; where a and b are not 0 at the same time.)

(compound represented by formula (d-1))

In the formula (d-1), the alkanediyl group having 1 to 3 carbon atoms of R ¹ and R ² may, for example, be a methylene group, an ethylidene group, a propane-1,2-diyl group or a propane-1. 3-diyl, propane-2,3-diyl and the like. Among these alkanediyl groups, a methylene group, an ethylidene group or a propane-1,3-diyl group is preferable.

X ¹ and X ² are a single bond, -O-, -S-, -OCO- or -COO-. Further, X ¹ and X ² may be the same or different. Among these groups, X ¹ and X ^{2 are} preferably a single bond, -O- or -S-.

Y ¹ is an oxygen atom or a sulfur atom. It is preferably an oxygen atom.

In the case of n1=0, the two primary amine groups of the compound represented by the formula (d-1) may be bonded to the same benzene ring, or may be bonded to two different benzene rings. One knot. On the other hand, in the case of n1 = 1, two primary amine groups are each bonded to each other on a different benzene ring.

The bonding position of the primary amine group on the benzene ring is not particularly limited. For example, when the primary amine group on the benzene ring is one, the bonding position of the primary amino group may be any of the 2-position, 3-position, and 4-position with respect to the other group, and is preferably 3 - Bit or 4-position, more preferably 4-position. Further, when the number of the primary amine groups on the benzene ring is two, the bonding position of the primary amino group to the other group may, for example, be a 2,4-position, a 2,5-position or the like, and among them, preferably 2 ,4.

Further, the hydrogen atom on the benzene ring to which the primary amine group is bonded may be a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent group having at least one hydrogen atom on the hydrocarbon group substituted by a fluorine atom, or a fluorine atom. Replace. The monovalent hydrocarbon group in this case may, for example, be an alkyl group having 1 to 10 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group (such as a phenyl group), or an aralkyl group (such as a benzyl group).

Preferable specific examples of the compound represented by the formula (d-1), and examples of the compound of n1 = 0 include 4,4'-diaminodiphenylamine and 2,4-diaminodiphenyl. Amines and the like; examples of the compound having n1 = 1 include: 1,3-bis(4-aminobenzyl)urea, 1,3-bis(4-aminophenethyl)urea, and 1,3-bis (3) -aminobenzyl)urea, 1-(4-aminobenzyl)-3-(4-aminophenethyl)urea, 1,3-bis(2-(4-aminophenoxy)B 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-aminophenethyl)urea, 1,3-bis(2-(2-aminobenzylideneoxy)ethyl)urea, 1, 3-bis(3-(2-aminobenzimidyloxy)propyl)urea and the like. Further, the compound represented by the formula (d-1) may be used alone or in combination of two or more of these compounds. Used together.

(compound represented by formula (d-2))

In the formula (d-2), X ³ is a single bond, -O- or -S-, and is preferably a single bond or -O-.

In the case of m1=0, m2 is an integer of 1-12. In this case, from the viewpoint of improving the heat resistance of the obtained polymer, m2 is preferably from 1 to 10, and more preferably from 1 to 8. In addition, from the viewpoint of maintaining a good liquid crystal alignment property and improving the rubbing resistance, m1 is preferably 0, and m1 is preferably an integer of 1 to 3 from the viewpoint of reducing the pretilt angle of the liquid crystal molecules.

The bonding position of the primary amine group on the benzene ring is not particularly limited, and each primary amino group is preferably a 3-position or a 4-position, and more preferably a 4-position, with respect to the other groups. Further, the hydrogen atom on the benzene ring to which the primary amine group is bonded may be a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent group having at least one hydrogen atom on the hydrocarbon group substituted by a fluorine atom, or a fluorine atom. Replace.

Preferable specific examples of the compound represented by the formula (d-2) include bis(4-aminophenoxy)methane, bis(4-aminophenoxy)ethane, and bis(4-amine). Phenoxy)propane, bis(4-aminophenoxy)butane, bis(4-aminophenoxy)pentane, bis(4-aminophenoxy)hexane, bis(4- Aminophenoxy)heptane, bis(4-aminophenoxy)octane, bis(4-aminophenoxy)decane, bis(4-aminophenoxy)decane, bis( 4-aminophenyl)methane, bis(4-aminophenyl)ethane, bis(4-aminophenyl)propane, bis(4-aminophenyl)butane, bis(4-amine Phenyl)pentane, bis(4-aminophenyl)hexane, bis(4-aminophenyl)heptane, bis(4-aminophenyl)octane, bis(4-aminophenyl) ) decane, bis(4-aminophenyl)decane, 1,3-bis(4-aminophenylindenyl)propane, 1,4-bis(4-aminophenylindenyl) Butane and so on. In addition, the compound represented by the formula (d-2) may be used alone or in combination of two or more kinds.

(compound represented by formula (d-3))

In the formula (d-3), R ³ is a linear or branched monovalent hydrocarbon group having 1 to 12 carbon atoms. Specific examples thereof include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group or a decyl group; An alkenyl group such as a propyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; an aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a benzyl group; The carbon number of R ³ is preferably from 1 to 6, more preferably from 1 to 3. Further, R ³ is preferably a chain hydrocarbon group, preferably a chain hydrocarbon group containing a carbon-carbon double bond, and more preferably an alkenyl group such as an allyl group.

R ⁴ is a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an aromatic hydrocarbon group having 5 to 12 carbon atoms. Specific examples thereof include those exemplified in the description of R ³ . Base. R ⁴ is preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group, and are each preferably a hydrogen atom.

In the diaminophenyl group of the formula (d-3), the bonding position of the two primary amino groups is not particularly limited, and is preferably 2 with respect to the N-allyl structure bonded to the benzene ring. 4-bit or 2,5-position, more preferably 2,4-position. Further, the hydrogen atom on the benzene ring to which the primary amine group is bonded may be a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent group having at least one hydrogen atom on the hydrocarbon group substituted by a fluorine atom, or a fluorine atom. Replace.

Preferred specific examples of the compound represented by the formula (d-3) can be listed, for example, Take: 2,4-diamino-N,N-diallylaniline, 2,5-diamino-N,N-diallylaniline, the following formula (d-3-1)~ (d-3-3) A compound or the like represented by each. Among these compounds, 2,4-diamino-N,N-diallylaniline or 2,5-diamino-N,N-diallylaniline can be preferably used.

(compound represented by formula (d-4))

In the formula (d-4), the divalent group represented by "-X ⁴ -(R ⁷ -X ⁵ ) _k -" is preferably an alkanediyl group having a carbon number of 1 to 3, *-O-, *-COO- Or *-OC ₂ H ₄ -O- (wherein the bond labeled "*" is bonded to the diaminophenyl group).

The group "-C _c H _2c+1 " is preferably linear, and specific examples thereof include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group. Base, n-decyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecane Base, n-nonadecyl, n-icosyl and the like.

The two primary amino groups in the diaminophenyl group are preferably the 2,4-position or the 3,5-position, and more preferably the 2,4-position, relative to the group "X ⁴ ". Further, the hydrogen atom on the benzene ring to which the primary amine group is bonded may be substituted with a fluorine atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a group in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom.

Preferable specific examples of the compound represented by the formula (d-4) include a compound represented by the following formula (d-4-1) to formula (d-4-11), and the like.

When the polyglycolic acid of the present invention is synthesized, the specific diamine can be appropriately selected from the compounds depending on the driving mode of the liquid crystal display element to be produced. Specifically, a liquid crystal alignment 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, 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), it is possible to produce a product suitable for twisting nematic ( Liquid crystal alignment agent for Twisted Nematic, TN) type liquid crystal display element by using the above formula The compound represented by (d-4) can produce a liquid crystal alignment agent suitable for use in a vertical alignment type liquid crystal display device.

[Molecular weight regulator]

In the case of synthesizing polyamic acid, a terminal-modified polymer can be synthesized using an appropriate molecular weight modifier while using the tetracarboxylic dianhydride and the diamine as described above. 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. Specific examples of the compound include, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecane. A butyl succinic anhydride, n-hexadecyl succinic anhydride or the like; examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octyl Examples of the monoisocyanate compound include a phenyl isocyanate and a naphthyl isocyanate.

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

<Synthesis of polylysine>

The ratio of the tetracarboxylic dianhydride to the diamine to be used in the synthesis reaction of the polyaminic acid of the present invention is preferably 1 equivalent to the amine group of the diamine, and the acid anhydride group of the tetracarboxylic dianhydride is 0.2 equivalent to 2 equivalents. The ratio is more preferably 0.3 to 1.2 equivalents.

The synthesis reaction of polylysine is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. Further, the reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

Here, examples of the organic solvent include an aprotic polar solvent, a phenol solvent, an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon.

Specific examples of the organic solvent include, for example, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone (1,3-dimethyl-2-). Imidazolidinone), N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylhydrazine, γ-butyrolactone, tetramethylurea And hexamethylphosphonium triamine, a compound represented by the following formula (1), and the like; examples of the phenol solvent include phenol, m-cresol, xylenol, and halogenated phenol; and 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, and cyclohexanone; and examples of the ester include ethyl lactate, butyl lactate, methyl acetate, and ethyl acetate. Butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc.; Examples of the ether include diethyl ether, diisoamyl ether, ethylene glycol methyl ether, ethylene glycol diethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether, and ethylene. Alcohol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol 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, etc.; Examples of the halogenated hydrocarbon include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like; : hexane, heptane, octane, benzene, toluene, xylene, and the like.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenol solvent (the organic solvent of the group A), or an organic solvent selected from the group A, is preferably used. One or more kinds of a mixture of one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (group B organic solvent). In the latter case, the use ratio of the organic solvent of the Group B group is preferably 50% by weight or less, and more preferably 40% by weight based on the total amount of the organic solvent of the Group A group and the organic solvent of the Group B group. Hereinafter, it is especially preferably 30% by weight or less.

The amount (a) of the organic solvent to be used is preferably in an amount of from 0.1% by weight to 50% by weight based on the total amount (a+b) of the reaction solution, and the total amount (b) of the tetracarboxylic dianhydride and the diamine.

A reaction solution obtained by dissolving polylysine was obtained in the above manner. The reaction solution may be directly supplied to the preparation of the liquid crystal alignment agent, or the poly-proline acid contained in the reaction solution may be isolated and then supplied to the preparation of the liquid crystal alignment agent, or the isolated polylysine may be purified. Further provided for the preparation of the liquid crystal alignment agent. In the case where polylysine is dehydrated and closed to form a polyimine, the reaction solution may be directly supplied to a dehydration ring-closure reaction, or the polylysine contained in the reaction solution may be isolated and then supplied to The dehydration ring closure reaction, or the isolated polyamic acid can also be purified and then supplied to the dehydration ring closure reaction. Separation and purification of polylysine can be based on known The way to proceed.

<Synthesis of Polyimine and Polyimine>

The polyimine contained in the liquid crystal alignment agent of the present invention can be obtained by subjecting polylysine synthesized in the above manner to dehydration ring closure and imidization of ruthenium.

The polyimine may be a fully ruthenium imide obtained by dehydration ring closure of a proline structure of a polyglycolic acid as a precursor thereof, or may be a part of only a proline structure. A partial quinone imide that dehydrates the ring closure and allows the proline structure to coexist with the quinone ring structure. The polyimine in the present invention preferably has a sulfhydrylation ratio of 30% or more, more preferably 40% to 99%, and particularly preferably 50% to 99%. The ruthenium imidation ratio is a total of the number of the guanidine structure of the polyimine and the number of the quinone ring structure, and the ratio of the number of the quinone ring structure is expressed as a percentage. Here, a part of the quinone ring may be an isoindole ring.

The dehydration ring closure of polylysine is preferably carried out by a method of heating polylysine; or dissolving polylysine in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, A method of heating is required. Among them, it is preferred to use the latter method.

In the method of adding a dehydrating agent and a dehydration ring-closure catalyst to a solution of polyamic acid, 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 used is preferably set to 0.01 mol to 20 mol with respect to 1 mol of the proline structure of polylysine. As the dehydration ring-closing catalyst, for example, a tertiary amine such as pyridine, collidine, lutidine or triethylamine can be used. Excellent use of dehydration closed-loop catalyst relative to the dehydrating agent used Choose to be set to 0.01 m to 10 m. The organic solvent used in the dehydration ring-closure reaction is exemplified as an organic solvent exemplified as an organic solvent for synthesizing polyamic acid. 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.

A reaction solution containing polyienimine was obtained in the above manner. The reaction solution can be directly supplied to the preparation of the liquid crystal alignment agent, or the dehydration agent and the dehydration ring closure catalyst can be removed from the reaction solution, and then supplied to the preparation of the liquid crystal alignment agent, or the polyimine can be isolated and then supplied to the liquid crystal alignment. The preparation of the agent, or the isolated polyimine may also be purified and then supplied to the preparation of the liquid crystal alignment agent. These purification operations can be carried out in accordance with a known method.

<Polyurethane>

The polyphthalamide contained in the liquid crystal alignment agent of the present invention can be obtained, for example, by the following method: [I] by the polyamine acid obtained by the synthesis reaction, a compound containing a hydroxyl group, a halide, and the like a method of reacting an epoxy group-containing compound or the like to carry out a reaction; [II] a method of reacting a tetracarboxylic acid diester with a diamine; and [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine .

Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol, and propanol; and phenols such as phenol and cresol. Further, examples of the halide include methyl bromide, ethyl bromide, octadecyl octadecyl, methyl chloride, chlorooctadecane, 1,1,1-trifluoro-2-iodoethane, and the like. Examples of the compound include propylene oxide and the like. The tetracarboxylic acid diester used in the method [II] can be, for example, by using the alcohol, the polyfluorene The tetracarboxylic dianhydride exemplified in the synthesis of the amine acid is obtained by ring opening. Further, the tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting a tetracarboxylic acid diester obtained in the above manner with a suitable chlorinating agent such as sulfinium chloride. The diamine or the like exemplified in the synthesis of the polyamic acid can be used as the diamine used in the methods [II] and [III]. Further, the polyperurate may have only a phthalate structure, or may be a partial ester compound in which a valeric acid structure and a phthalate structure coexist.

<Solid viscosity and weight average molecular weight of polymer>

The polyamic acid, polyimine and polyphthalate obtained in the above manner are preferably 10 mPa when it is made into a solution having a concentration of 10% by weight. s~3,000mPa. The solution viscosity of s is more preferably 20 mPa. s~1,500mPa. s solution viscosity of the compound. Further, the solution viscosity (mPa.s) of the polymer means a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, 1,3-dimethyl-) for using the polymer. A polymer solution having a concentration of 10% by weight prepared by 2-imidazolidinone, N-ethyl-2-pyrrolidone or the like, which was measured at 25 ° C using an E-type rotational viscometer. Further, the polyamic acid, the polyimine, and the polyphthalate contained in the liquid crystal alignment agent of the present invention are converted to polystyrene by gel permeation chromatography (GPC). The weight average molecular weight is preferably from 500 to 100,000, more preferably from 1,000 to 50,000.

<polyorganooxane>

The polyorganosiloxane of the present invention can be hydrolyzed or hydrolyzed, for example, by hydrolyzing a decane compound, preferably in the presence of a suitable organic solvent, water and a catalyst. Obtained by condensation.

Examples of the hydrolyzable decane compound used for the synthesis of the polyorganosiloxane are methyl trichlorodecane, methyl trimethoxy decane, methyl triethoxy decane, phenyl trichloro decane, and phenyl trimethoxy decane. , phenyl triethoxy decane, methyl dichloro decane, methyl dimethoxy decane, methyl diethoxy decane, dimethyl dichloro decane, dimethyl dimethoxy decane, dimethyl Diethoxy decane, diphenyl dichlorodecane, diphenyl dimethoxy decane, diphenyl diethoxy decane, chlorodimethyl decane, methoxy dimethyl decane, ethoxy dimethyl Base decane, chlorotrimethyl decane, bromotrimethyl decane, iodine trimethyl decane, methoxy trimethyl decane, ethoxy trimethyl decane, tetramethoxy decane, tetraethoxy decane, ten Octatrichlorotrimethane, octadecyltrimethoxydecane, vinyltrichlorodecane, vinyltrimethoxydecane, vinyltriethoxydecane,allyltrichlorodecane,allyltrimethoxy Decane, allyl triethoxy decane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 3-glycidoxypropyl Methyldiethoxydecane, 3-glycidoxypropyldimethylmethoxydecane, 3-glycidoxypropyldimethylethoxydecane, 2-glycidoxyethyltrimethyl Oxydecane, 2-glycidoxyethyltriethoxydecane, 2-glycidoxyethylmethyldimethoxydecane, 2-glycidoxyethylmethyldiethoxydecane, 2-glycidoxyethyl dimethyl methoxy decane, 2-glycidoxyethyl dimethyl ethoxy decane, 4-glycidoxy butyl trimethoxy decane, 4-glycidyl oxygen Butyl triethoxy decane, 4-glycidoxy butyl dimethyl dimethoxy decane, 4-glycidoxy butyl dimethyl diethoxy decane, 4-glycidoxy butyl Dimethyl methoxy decane, 4-glycidoxy butyl dimethyl ethoxy decane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxy decane, 2-(3,4 -Epoxycyclohexyl)ethyltriethoxydecane, 3-(3,4-epoxycyclohexyl)propyltrimethoxydecane, 3-(3,4-epoxycyclohexyl)propyl Triethoxy decane, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (3-methyloxetan-3-yl)methyl (meth)acrylate ester, 3-(Methyl) propylene methoxy propyl trichloro decane, 3-(methyl) propylene methoxy propyl trimethoxy decane, 3-(methyl) propylene methoxy propyl triethoxy decane , 2-(Methyl)propenyloxyethyltrichlorodecane, 2-(methyl)propenyloxyethyltrimethoxydecane, 2-(methyl)propenyloxyethyltriethoxy Decane, 4-(methyl)propenyloxybutyltrichlorodecane, 4-(methyl)propenyloxybutyltrimethoxydecane, 4-(methyl)propenyloxybutyltriethoxy Base decane and the like. Further, "(meth)acryloxy" is a meaning including "acryloxy" and "methacryloxy".

Examples of the organic solvent which can be used in the synthesis of the polyorganosiloxane are hydrocarbons, ketones, esters, ethers, alcohols and the like. Here, examples of the hydrocarbon include toluene, xylene, and the like; and examples of the ketone include methyl ethyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, diethyl ketone, and cyclohexane. a ketone or the like; examples of the ester include ethyl acetate, n-butyl acetate, isoamyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, ethyl lactate, and the like; Examples of the ether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, dioxane, and the like; and examples of the alcohol include 1-hexanol, 4-methyl-2-pentanol, and ethylene glycol. Monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether and the like. Among these organic solvents, it is preferred to use a water-insoluble organic solvent. In addition, These organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent used in the case of synthesizing the polyorganosiloxane is preferably from 10 parts by weight to 10,000 parts by weight, and more preferably from 50 parts by weight to 1,000 parts by weight, based on 100 parts by weight of the total of the decane compound. Further, the amount of water used in the production of the polyorganosiloxane is preferably from 0.5 to 100 moles, more preferably from 1 to 30 moles, per mole of the decane compound to be used.

Examples of the catalyst which can be used in the synthesis of the polyorganosiloxane are an acid, an alkali metal compound, an organic base, a titanium compound, a zirconium compound and the like. Here, examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, formic acid, oxalic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, phosphoric acid, and the like; and examples of the alkali metal compound include sodium hydroxide. Potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, etc.; the organic base is, for example, a first grade such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine or pyrrole. a secondary organic amine; a tertiary organic amine such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, diazabicycloundecene A quaternary organic amine such as tetramethylammonium hydroxide.

The catalyst is particularly preferably an organic base. The amount of the organic base to be used varies depending on the type of the organic base, the reaction conditions, and the like, and can be appropriately set. For example, it is preferably 0.01 to 3 moles, more preferably 0.05 moles, per mole of the decane compound. ~1 times Moule.

Hydrolysis or hydrolysis when the polyorganosiloxane is produced. The condensation reaction is preferably carried out by dissolving one or two or more kinds of hydrolyzable decane compounds in an organic solvent, and mixing the obtained solution with an organic base and water. For example, heating is performed using an oil bath or the like.

hydrolysis. In the case of the condensation reaction, the heating temperature is preferably 130 ° C or lower, more preferably 40 ° C to 100 ° C, and heating is preferably carried out for 0.5 to 12 hours, more preferably for 1 to 8 hours. While heating, the mixture may be stirred or placed under reflux.

After completion of the reaction, it is preferred to wash the organic solvent layer separated from the reaction liquid by water. In the case of this washing, in terms of facilitating the washing operation, it is preferred to wash by using water containing a small amount of salt, for example, an aqueous solution of ammonium nitrate of about 0.2% by weight. The cleaning is carried out until the water layer after the cleaning is neutral. Then, the organic solvent layer is dried with a desiccant such as anhydrous calcium sulfate or molecular sieve, and the solvent is removed, whereby the desired polyorganosiloxane can be obtained. Further, a commercially available product can also be used as the polyorganosiloxane of the present invention.

The polyorganosiloxane which is contained in the liquid crystal alignment agent of the present invention may be a compound which reacts with a reactive compound by reacting the reactive polyorganosiloxane obtained by the condensation reaction with the reactive compound. A structure derived from a reactive compound is introduced into the side chain of the polyorganosiloxane. Here, examples of the reactive polyorganosiloxane include a polyorganosiloxane having an epoxy group, an unsaturated double bond, a thiol group, an amine group, and the like. Further, examples of the reactive compound include a compound having a long-chain alkyl group, a compound having a structure in which two or more rings (for example, a benzene ring or a cyclohexane ring) are bonded, a compound having a steroid skeleton, and having an unsaturated group. Double bond compounds, etc. Specifically, for example, a compound described in the specification of Japanese Patent Application No. 2013-77493 can be used as the reactive compound.

Further, the reaction of the reactive polyorganosiloxane with the reactive compound can be carried out in accordance with a conventional method of organic chemistry. For example, when the reactive polyorganosiloxane has an epoxy group, a structure derived from a reactive compound can be introduced into a side chain of the reactive polyorganosiloxane by using a carboxylic acid as a reactive compound. Further, in the case where the reactive polyorganosiloxane has an unsaturated double bond, it can be introduced into the side chain of the reactive polyorganosiloxane by using a compound having a mercapto group or an amine group as a reactive compound. The structure of the reactive compound.

In the polyorganosiloxane of the present invention, the polystyrene-equivalent weight average molecular weight measured by GPC is preferably 500 to 100,000, more preferably 1,000 to 30,000, particularly preferably 1,000 to 20,000.

<solvent>

The solvent contained in the liquid crystal alignment agent of the present invention contains at least a compound (p1) represented by the following formula (1) as a solvent component.

(In the formula (1), R ¹ to R ⁴ are each independently a linear or branched hydrocarbon group having 1 to 6 carbon atoms or a group selected from -O-, -COO- and between CC bonds of the hydrocarbon group; a base of at least one of -OCO-.)

In the examples of R ¹ to R ⁴ in the formula (1), the hydrocarbon group having 1 to 6 carbon atoms may be a chain hydrocarbon group having 1 to 6 carbon atoms, an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and these hydrocarbon groups may be saturated or unsaturated. It can be linear or branched. Specific examples of R ¹ to R ⁴ include a methyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group; and a vinyl group and an allyl group; A monovalent unsaturated hydrocarbon group or the like. R ¹ to R ⁴ are preferably a chain hydrocarbon group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably a methyl group. Further, in the formula (1), R ¹ to R ⁴ may be the same as or different from each other.

Preferable specific examples of the compound (p1) include a compound represented by the following formula (1-1) (N,N,2-trimethylpropionamide).

The content of the compound (p1) is preferably 0.1% by weight or more, more preferably 1% by weight or more, particularly preferably 5% by weight or more, particularly preferably 10% by weight or more, based on the total amount of the solvent contained in the liquid crystal alignment agent. . In addition, the upper limit of the content is preferably 90% by weight or less, more preferably 85% by weight or less, and particularly preferably 80% by weight or less, based on the total amount of the solvent contained in the liquid crystal alignment agent.

In addition, from the viewpoint of surface unevenness, relative to the liquid crystal alignment agent The total amount of the solvent contained, the upper limit of the content of the compound (p1) is preferably 95% by weight or less, and more preferably 90% by weight or less. Further, the compound (p1) may contain N-methylisobutylguanamine, isobutylguanamine, isobutyronitrile, dimethylamine or the like as an impurity. In this case, the preferable range of the content ratio of the compound (p1) is defined as a range that defines the amount of the compound (p1) containing the impurity.

[other solvents]

As the solvent for preparing the liquid crystal alignment agent of the present invention, other solvents than the compound (p1) can be used. Examples of the other solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, and N,N-dimethylacetamide. , 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate , ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene Alcohol ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene Alcohol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, Propylene carbonate, tert-butanol, third pentanol, 3-butoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, 3 -Hexyloxy-N,N-dimethylpropanamide, isopropoxy-N-isopropyl-propionamide, n-butoxy-N-isopropyl-propionamide , N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-pentyl-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2- Pyrrolidone, N-methoxybutyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ethylene glycol diacetate, propylene glycol diacetate, diacetone alcohol, tert-butyl Alcohol, third pentanol, and the like. In addition, the solvent may be used alone or in combination of two or more.

The content of the other solvent is preferably 99% by weight or less, more preferably the total amount of the solvent contained in the liquid crystal alignment agent, from the viewpoint of sufficiently obtaining the effect of the compound (p1). It is 95% by weight or less, and particularly preferably 80% by weight or less. In addition, the lower limit of the content of the other solvent is preferably 10% by weight or more, and more preferably 15% by weight or more, and particularly preferably from the viewpoint of the total amount of the solvent contained in the liquid crystal alignment agent. It is preferably 20% by weight or more.

<Other additives>

The liquid crystal alignment agent of the present invention contains the polymer and the solvent as described above, but may contain other components as needed. Examples of the other component include a polymer other than the polymer, a compound having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), a functional decane compound, and radical generation. Agents, etc.

[Other polymers]

The other polymers can be used to improve solution properties or electrical properties. Examples of the other polymer include polyester, polyamine, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenylmethylene iodide) derivative, and poly (Meth) acrylate, etc. In the case where the other polymer is added to the liquid crystal alignment agent, The compounding ratio of the other polymer is preferably 50% by weight or less, more preferably 0.1% by weight to 40% by weight, particularly preferably 0.1% by weight to 30% by weight based on the total amount of the polymer in the composition.

[epoxy group-containing compound]

The epoxy group-containing compound can be used to improve the adhesion of the liquid crystal alignment film to the surface of the substrate. Here, examples of the epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromo neopentyl 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-diglycidyl-benzylamine, N,N-diglycidyl-aminomethyl Cyclohexane, N,N-diglycidyl-cyclohexylamine, and the like.

When the epoxy compound is added to the liquid crystal alignment agent, the compounding ratio of the epoxy compound is preferably 40 parts by weight or less, more preferably 100 parts by weight based on 100 parts by total of the polymer contained in the liquid crystal alignment agent. It is from 0.1 part by weight to 30 parts by weight.

[functional decane compound]

The functional decane compound can be used for the purpose of improving the printability of the liquid crystal alignment agent. Examples of such a functional decane compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, and 2-aminopropyltrimethoxysulfonium. Alkane, 2-aminopropyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-amine Propyl propyl dimethoxy decane, 3-ureidopropyl trimethoxy decane, 3-ureidopropyl triethoxy decane, N-ethoxycarbonyl-3-aminopropyl trimethoxy Decane, N-triethoxydecylpropyltriethylamine, 10-trimethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6 - diazepine acetate, methyl 9-trimethoxydecyl-3,6-diazadecanoate, N-benzyl-3-aminopropyltrimethoxydecane, N-phenyl 3-aminopropyltrimethoxydecane, glycidoxymethyltrimethoxydecane, 2-glycidoxyethyltrimethoxydecane, 3-glycidoxypropyltrimethoxydecane, and the like.

In the case where the functional decane compound is added to the liquid crystal alignment agent, the compounding ratio of the functional decane compound is preferably 2 parts by weight or less, more preferably 0.02 parts by weight, based on 100 parts by total of the total of the polymer. 0.2 parts by weight.

[Free radical generator]

The radical generating agent is a compound capable of generating a radical by irradiation with radiation such as visible light, ultraviolet light, far ultraviolet light, electron beam, or X-ray, and can be contained in the liquid crystal alignment for the purpose of promoting the reaction of the radical reactive compound. The agent (especially a liquid crystal alignment agent for producing a polymer-stable alignment (PSA) mode liquid crystal display element).

The radical generating agent is not particularly limited, and a conventionally known compound can be used. Specific examples of the radical generating agent include acetophenone, benzophenone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, and xanthone. (xanthone), fluorenone, benzaldehyde, hydrazine (anthraquinone), triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, mischrone, 1-(4-isopropylphenyl)-2-hydroxy-2 -methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one , thioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propan-1-one, diphenyl (2,4,6- Trimethoxy benzhydryl) phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2,4,6-trimethyl Benzopyridyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzylidene)phenylphosphine oxide, 1,2-octanedione, 1-[4-(phenylthio) -,2-(O-benzhydrylhydrazine)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzhydryl)-9H-indazol-3-yl]-, 1-(O-acetonitrile), polymethylphenyl decane, and the like. The radical generating agent may be used alone or in combination of two or more.

In the case where a radical generating agent is added to the liquid crystal alignment agent, the compounding ratio of the radical generating agent is preferably 20 parts by weight or less, more preferably 0.1 parts by weight to 5 parts by weight based on 100 parts by total of the total of the polymer. Parts by weight.

Other additives contained in the liquid crystal alignment agent may be, in addition to the above, a metal chelate compound such as an ethylene acetone complex or a ruthenium acetate complex selected from a metal selected from the group consisting of aluminum, titanium, and zirconium, and the like. A curing accelerator such as a phenol group-based compound, a surfactant, a compound having at least one oxetanyl group in the molecule, an antioxidant, and the like.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, and the like, and is preferably selected. It is in the range of 1% by weight to 10% by weight. That is, the liquid crystal alignment agent of the present invention is applied to the substrate by a method described later. It is preferable that the surface of the board is heated to form a coating film as a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film. However, in the case where the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small. A good liquid crystal alignment film cannot be obtained. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, and a favorable liquid crystal alignment film cannot be obtained, and the viscosity of the liquid crystal alignment agent increases, and the coating property deteriorates.

The range of the particularly preferable solid content concentration differs depending on the method used when the 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 weight to 4.5% by weight. In the case of using the offset printing method, it is particularly preferable to set the solid content concentration to a range of 3% by weight to 9% by weight, thereby setting the solution viscosity to 12 mPa. s~50mPa. 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 weight to 5% by weight, thereby setting the solution viscosity to 3 mPa. s~15mPa. The scope of s.

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

<Liquid alignment film and liquid crystal display element>

The liquid crystal alignment film of the present invention is formed by using a liquid crystal alignment agent prepared in the above manner. Further, the liquid crystal display element of the present invention comprises a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention. The driving mode of the liquid crystal display element to which the present invention is applied is not particularly limited, and can be applied to a TN type, an STN type, an IPS type, an FFS type, a VA type, a multi-domain vertical alignment (MVA) type, or the like. Multiple drive modes. Hereinafter, a method for producing a liquid crystal display device of the present invention will be described, and in the description, a method for producing a liquid crystal alignment film of the present invention will be described.

The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). Step (1) uses different substrates depending on the desired driving mode. Step (2) and step (3) are common to each drive mode.

[Step (1): Formation of coating film]

First, the liquid crystal alignment agent of the present invention is applied onto a substrate, and then the coated surface is heated to form a coating film on the substrate.

(1-1) In the case of manufacturing a TN type, STN type or VA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are used as a pair, and each transparent conductive film on the substrate On the formation surface, the liquid crystal alignment agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method, respectively. The coating method of the liquid crystal alignment agent can preferably employ the offset printing method in the above methods. Here, as the substrate, for example, glass such as float glass or soda glass may be used; and polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, poly(alicyclic olefin) may be used. ) A transparent substrate such as plastic. The transparent conductive film provided on one side of the substrate may be a Neisser (NESA) film containing tin oxide (SnO ₂ ) (registered trademark of PPG, USA), and containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ). Indium Tin Oxide (ITO) film or the like. In order to obtain a patterned transparent conductive film, for example, it is possible to utilize light after forming a transparent conductive film without a pattern. A method of etching to form a pattern; a method of forming a mask having a desired pattern when forming a transparent conductive film, or the like. When the liquid crystal alignment agent is applied, in order to improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, a functional decane compound or a functional titanium compound may be applied to the surface on the surface of the substrate where the coating film is to be formed. Pre-processing.

After the liquid crystal alignment agent is applied, it is preferable to perform preheating (prebaking) for the purpose of preventing sag of the applied alignment agent. The prebaking temperature is preferably from 30 ° C to 200 ° C, more preferably from 40 ° C to 150 ° C, and particularly preferably from 40 ° C to 100 ° C. The prebaking time is preferably from 0.25 minutes to 10 minutes, more preferably from 0.5 minutes to 5 minutes. Then, the calcination (post-baking) step is carried out for the purpose of completely removing the solvent, if necessary, by subjecting the proline structure present in the polymer to thermal imidization. The calcination (post-baking) temperature is preferably from 80 ° C to 300 ° C, more preferably from 120 ° C to 250 ° C. The post-baking time is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. The film thickness of the film formed as described above is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface is provided on a substrate provided with an electrode including a transparent conductive film or a metal film patterned into a comb-tooth type, and is not provided The liquid crystal alignment agent of the present invention is applied to one surface of the opposite substrate of the electrode, and then each coated surface is heated to form a coating film. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film, The description (1-1) is the same. As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the above (1-1) and (1-2), a coating film to be an alignment film is formed by applying a liquid crystal alignment agent onto a substrate and then removing the organic solvent. In this case, the polymer contained in the liquid crystal alignment agent of the present invention is a polyamic acid, or a quinone imidized polymer having a quinone ring structure and a proline structure, or having a phthalate. In the case of a polymer having a structure and a proline structure, a dehydration ring-closure reaction may be carried out by further heating after the formation of the coating film to form a more imidized coating film.

[Step (2): Orientation ability treatment]

Then, the coating film formed on the substrate is subjected to a rubbing treatment or a light irradiation treatment as needed, thereby imparting a liquid crystal alignment ability to the coating film.

First, in the case of manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the rubbing treatment is performed by using a roll in which a cloth including fibers such as nylon, rayon, cotton, or the like is wound. The coating film formed in the step (1) is rubbed in a fixed direction. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. On the other hand, in the case of manufacturing a VA liquid crystal display element, the coating film formed in the above step (1) can be directly used as a liquid crystal alignment film, and the coating film can be subjected to a rubbing treatment.

Further, the liquid crystal alignment film after the rubbing treatment is further subjected to a treatment of changing a pretilt angle of a partial region of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, and forming a resist on a part of the surface of the liquid crystal alignment film. After the film, the rubbing treatment is performed in a direction different from the previous rubbing treatment, and then the treatment of the resist film is removed; thereby making the liquid crystal alignment film different in each region LCD alignment capability. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved.

On the other hand, in the case of the light irradiation treatment (photoalignment method), the substrate after the formation of the coating film is irradiated with polarized light or non-polarized radiation to the coating film surface to impart liquid crystal alignment ability to the coating film. Here, as the radiation, for example, ultraviolet rays or visible rays containing light having a wavelength of 150 nm to 800 nm can be used. Among them, ultraviolet rays containing light having a wavelength of 300 nm to 400 nm are preferable. When the radiation to be used is polarized (linearly polarized or partially polarized), the light irradiation direction may be a direction perpendicular to the coating film surface, or may be an oblique direction in order to impart a pretilt angle. On the other hand, in the case of irradiating radiation of non-polarized light, it is necessary to irradiate light to the surface of the coating film from the oblique direction.

As the light source, 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 excimer laser or the like can be used. The ultraviolet light in the preferred wavelength region can be obtained by a method in which a light source is used in combination with, for example, a filter, a diffraction grating, or the like. The irradiation amount of the radiation is preferably 1 J/m ² or more and less than 20,000 J/m ² , and more preferably 10 J/m ² to 10,000 J/m ² . Further, according to the photo-alignment treatment, a liquid crystal alignment film is produced by applying light irradiation to the coating film formed on the substrate to impart a liquid crystal alignment ability to the coating film.

[Step (3): Construction of liquid crystal cell]

Two substrates in which the liquid crystal alignment film was formed as described above were prepared, and liquid crystal cells were produced by disposing liquid crystal between the two substrates arranged in the opposite direction. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.

The first method is a previously known method. First, the liquid crystal alignment films are opposed to each other with a gap (cell gap) interposed therebetween, and the peripheral portions of the two substrates are bonded together using a sealant, and the cells are separated 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. In addition, the second method is a method called a One Drop Fill (ODF) method. Applying, for example, an ultraviolet curable sealant to a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed, and further adding liquid crystal to a predetermined number of portions on the liquid crystal alignment film surface, and then liquid crystal The alignment film is bonded to the other substrate in a facing manner, and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing agent, whereby the liquid crystal cell can be manufactured. In the case of using any of the methods, it is preferable to heat the liquid crystal cell produced in the above manner to a temperature at which the liquid crystal to be used becomes an isotropic phase, and then gradually cool to room temperature to remove the liquid crystal filling. Flow alignment.

As the sealant, for example, an epoxy resin containing a hardener and an alumina ball as a spacer can be used.

The liquid crystal may, for example, be a nematic liquid crystal or a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, and for example, a Schiff base liquid crystal or an azo azo (azoxy) may be used. Liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane An alkane liquid crystal, a cubane liquid crystal, or the like. In addition, it is also possible to use the following substances in these liquid crystals: for example, cholesteryl chloride (cholesteryl) Chloride, cholesteric liquid crystal, cholesteric liquid crystal, etc.; under the trade names "C-15", "CB-15" (Merck ( Merck produced by Merck); ferroelectrics such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate Liquid crystal (ferroelectric liquid crystal) and the like.

Then, 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. The polarizing plate to be bonded to the outer surface of the liquid crystal cell may be a polarizing plate in which a polarizing film called "H film" is sandwiched between a cellulose acetate protective film or a polarizing plate including the H film itself. The H film is a polarizing film obtained by absorbing iodine while extending the polyvinyl alcohol.

Further, in the case where the coating film is subjected to the rubbing treatment, the two substrates are arranged to face each other at a predetermined angle in the rubbing direction of each of the coating films, for example, orthogonally or anti-parallel. Further, when the coating film is irradiated with light, if the liquid crystal alignment film is level-aligned, the angle of the polarized light of the linearly polarized radiation that is irradiated on the two substrates on which the liquid crystal alignment film is formed can be adjusted. And the angle of each substrate and the polarizing plate to obtain a liquid crystal display element having a TN type or STN type liquid crystal cell. On the other hand, when the liquid crystal alignment film has a vertical alignment property, the cells are formed so that the directions of the easy alignment axes in the two substrates on which the liquid crystal alignment film is formed are parallel, and the polarizing plate is polarized on the cell. The polarizing plate is bonded to the easy-alignment axis at an angle of 45°, whereby a liquid crystal display element having a vertical alignment type liquid crystal cell can be produced.

The liquid crystal display element of the present invention may be an element having a liquid crystal alignment film imparted with a pretilt angle by a Polymer Sustained Alignment (PSA) technique. Such a PSA mode liquid crystal display element can be manufactured, for example, by a method including the following steps (I-1) to (I-3).

a method comprising the steps of: (I-1) coating a liquid crystal alignment agent on the conductive film of a pair of substrates having a conductive film, and heating the film to form a coating film; (I-2) comprising liquid crystal and a liquid crystal layer of a photopolymerizable compound, a step of arranging a pair of substrates on which the coating film is formed to form a liquid crystal cell, and (I-3) a conductive film on a pair of substrates The step of irradiating the liquid crystal cell with light in a state where a voltage is applied therebetween.

Regarding the step (I-1), the material of the substrate and the transparent conductive film to be used, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the coating formed The preferred film thickness of the film is the same as that of (1-1). Further, the coating film formed in the step (I-1) may be directly supplied to the following steps, or may be subjected to a rubbing treatment as needed to provide the following steps.

In the step (I-2), in addition to the liquid crystal filling or dropping in the step (3), the liquid polymerizable compound (photopolymerizable monomer) is used together with the liquid crystal to form a liquid crystal and photopolymerization. The liquid crystal cell was constructed in the same manner as in the above step (3) except for the liquid crystal layer of the compound. As the photopolymerizable compound, a functional group capable of undergoing radical polymerization such as an acrylonitrile group, a methacryloyl group or a vinyl group can be used. compound of. From the viewpoint of reactivity, polyfunctionality is preferable, and at least one of two or more acryloyl groups and methacryl fluorenyl groups in the molecule is more preferable. In addition, the photopolymerizable compound is preferably a compound having at least one of a cyclohexane ring and a benzene ring having a total of two or more in the molecule as a liquid crystal skeleton, from the viewpoint of stably maintaining the alignment property of the liquid crystal molecules. Further, as the photopolymerizable compound, a conventionally known compound can be used. The compounding ratio of the photopolymerizable compound is preferably from 0.1% by weight to 0.5% by weight based on the total amount of the liquid crystalline compound to be used.

In the step (I-3), after the liquid crystal cell is constructed, the liquid crystal cell is irradiated with radiation while a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be, for example, a direct current voltage of 5 V to 50 V or an alternating current voltage. The description of the optical alignment method can be applied to the wavelength of the irradiated radiation and the type of the light source. The irradiation amount of light is preferably 1,000 J/m ² or more and less than 200,000 J/m ² , and more preferably 1,000 J/m ² to 150,000 J/m ² . Further, according to the polymer stable alignment treatment, the coating film formed on the substrate is subjected to light irradiation to impart a liquid crystal alignment ability to the coating film to produce a liquid crystal alignment film.

Then, 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. Regarding the description of the polarizing plate, the description can be applied.

<Relativity film>

In the case of using the liquid crystal alignment agent of the present invention to produce a retardation film, it is possible to suppress dust or static electricity generation and form a uniform liquid crystal alignment film in the step, It is preferable to use the optical alignment method from the viewpoint of arbitrarily forming a plurality of regions having different liquid crystal alignment directions on the substrate by using an appropriate mask at the time of irradiation of the radiation. For example, the retardation film can be produced by the following steps (II-1) to (II-3).

[Step (II-1): Formation of Coating Film Using Liquid Crystal Aligning Agent]

First, the liquid crystal alignment agent of the present invention is applied onto a substrate to form a coating film. The substrate used herein may suitably be exemplified by containing triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polyamine, polyphthalamide. A transparent substrate of synthetic resin such as amine, polymethyl methacrylate or polycarbonate. Among these resins, TAC is generally used as a protective layer of a polarizing film in a liquid crystal display element. Further, polymethyl methacrylate can be preferably used as a substrate for a retardation film in terms of low hygroscopicity of the solvent, good optical properties, and low cost. Further, in order to improve the adhesion between the surface of the substrate and the coating film, the substrate used for the application of the liquid crystal alignment agent can perform a conventionally known pretreatment on the surface on which the coating film is formed on the surface of the substrate.

In most cases, the retardation film is used in combination with a polarizing film. At this time, in order to exhibit desired optical characteristics, it is necessary to precisely control the angle of the polarizing film with respect to the polarization axis in a specific direction to bond the retardation film. Therefore, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a direction of a predetermined angle on a substrate such as a TAC film or polymethyl methacrylate, it is possible to omit the angle of the retardation film while controlling the polarizing film. The step of bonding the retardation film. In addition, it is thereby possible to contribute to improvement in productivity of the liquid crystal display element. In order to form at a specified angle The liquid crystal alignment film having a liquid crystal alignment ability in the direction is preferably carried out by a photoalignment method using the liquid crystal alignment agent of the present invention.

The coating of the liquid crystal alignment agent on the substrate can be carried out by a suitable coating method, for example, a roll coater method, a spinner method, a printing method, an inkjet method, a bar coater method, an extrusion die method, or a direct method. Direct gravure coater method, chamber doctor coater method, offset gravure coater method, single roll kiss coater method, small diameter Reverse kiss coater method, three reverse roll coater method, four reverse roll coater method, slot die method, air knife coater method, positive rotating roll A coater method, a blade coater method, a knife coater method, an impregnation coater method, an MB coater method, an MB reverse coater method, or the like.

After coating, the coated surface is heated (baked) to form a coating film. The heating temperature at this time is preferably 40 to 150 ° C, and more preferably 80 to 140 ° C. The heating time is preferably from 0.1 minute to 15 minutes, and more preferably from 1 minute to 10 minutes. The film thickness of the coating film formed on the substrate is preferably from 1 nm to 1,000 nm, and more preferably from 5 nm to 500 nm.

[Step (II-2): Light irradiation step]

Then, the coating film formed on the substrate in the above manner is irradiated with light to impart a liquid crystal alignment ability to the coating film. Thereby, a liquid crystal alignment film was produced on the substrate. The description of the optical alignment process of the above step (2) can be applied to the description of the wavelength of the light to be irradiated, the type of light, and the light source to be used. Light irradiation amount is preferably set to ^{0.1mJ / cm 2 ~ 1,000mJ / cm} 2, and more preferably set to ^{1mJ / cm 2 ~ 500mJ / cm} 2, particularly preferably to ^{2mJ / cm 2 ~ 200mJ / cm} 2.

[Step (II-3): Formation of liquid crystal layer]

Then, the polymerizable liquid crystal is applied onto the coating film irradiated with light in the above manner and cured. Thereby, a coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used herein is a liquid crystal compound or a liquid crystal composition which is polymerized by at least one of heating and light irradiation. As the polymerizable liquid crystal, a conventionally known liquid crystal can be used. Specifically, for example, Non-Patent Document 1 ("UV-Curable Liquid Crystals and Their Application", "Liquid Crystal", The nematic liquid crystal described in Volume 3 (1999), page 34 to page 42). Further, it may be a cholesteric liquid crystal, a discotic liquid crystal, or a twisted nematic liquid crystal to which a chiral agent is added. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may be a composition containing a known polymerization initiator, a suitable solvent, or the like.

When the polymerizable liquid crystal as described above is applied onto the coating film formed using the liquid crystal alignment agent, for example, a suitable coating method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an inkjet method can be employed.

Then, one or more processes selected from the group consisting of heating and light irradiation are applied to the coating film of the polymerizable liquid crystal formed as described above, and the coating film is cured to form a liquid crystal layer. In terms of obtaining a good alignment, it is preferred to carry out these processes in an overlapping manner.

The heating temperature of the coating film can be appropriately selected depending on the type of the polymerizable liquid crystal to be used. For example, using RMS03-013C manufactured by Merck In the case, it is preferred to carry out heating at a temperature in the range of 40 ° C to 80 ° C. The heating time is preferably from 0.5 minutes to 5 minutes.

As the irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 nm to 500 nm can be preferably used. The amount of light irradiation is preferably 50 mJ/cm ² to 10,000 mJ/cm ² , and more preferably 100 mJ/cm ² to 5,000 mJ/cm ² .

The thickness of the formed liquid crystal layer is appropriately set in accordance with desired optical characteristics. For example, in the case of producing a 1/2 wavelength plate of visible light having a wavelength of 540 nm, the phase difference of the formed retardation film is selected to be a thickness of 240 nm to 300 nm, and when it is a quarter wave plate, the phase difference is selected to be 120 nm. 150 nm thickness. The thickness of the liquid crystal layer which obtains the target phase difference differs depending on the optical characteristics of the polymerizable liquid crystal to be used. For example, in the case of using RMS03-013C manufactured by Merck, the thickness for producing a quarter-wavelength plate is in the range of 0.6 μm to 1.5 μm.

The retardation film obtained in the above manner can be preferably used as a retardation film of a liquid crystal display element. The driving method of the liquid crystal display element of the retardation film produced by using the liquid crystal alignment agent of the present invention is not limited, and can be applied to various known methods such as TN type, STN type, IPS type, FFS type, and VA type. The retardation film is used by attaching a surface on the substrate side of the retardation film to the outer surface of the polarizing plate disposed on the visible side of the liquid crystal display element. Therefore, it is preferable to use an embodiment in which the substrate of the retardation film is a TAC or an acrylic substrate, and the substrate of the retardation film is a protective film of a polarizing film.

Further, a method of producing a retardation film on an industrial scale is a roll-to-roll method. The method is to perform the following processing in successive steps and will pass these A method in which a film after the step is recovered as a wound body: a film is wound up from a wound body of a long base film, a liquid crystal alignment film is formed on the wound film, and a liquid crystal alignment film is coated. The treatment of the polymerizable liquid crystal and hardening; and the treatment of laminating the protective film as needed. The phase difference film formed using the liquid crystal alignment agent of the present invention has good adhesion to the substrate, and when it is stored as a wound body, the liquid crystal alignment film and the substrate are also difficult to be peeled off. Therefore, it is possible to suppress a decrease in the yield of the product when the retardation film is produced by the roll-to-roll method.

The liquid crystal display element of the present invention can be effectively applied to various devices, for example, can be used for: a timepiece, a portable game, a word processor, a note type personal computer, a car. A display device such as a car navigation system, a camcorder, a personal digital assistant (PDA), a digital camera, a mobile phone, a smart phone, various monitors, and a liquid crystal television.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

The solution viscosity of each polymer solution in the synthesis example, the oxime imidization ratio of the polyimine, the weight average molecular weight, and the epoxy equivalent were measured by the following methods.

[Solid viscosity of polymer solution]

The solution viscosity (mPa.s) of the polymer solution was measured at 25 ° C using a predetermined solvent for a solution having a polymer concentration adjusted to 10% by weight using an E-type rotational viscometer.

[醯Iminization rate of polyimine]

The solution of the polyimine is put into pure water, and the obtained precipitate is sufficiently dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl hydrazine, using tetramethyl decane as a reference substance at room temperature. ¹ H--NMR measurement ^{(1 H-Nuclear magnetic resonance,} 1 H-NMR). From the obtained ¹ H-NMR spectrum, the oxime imidization ratio [%] was determined by the following formula (1).

醯imination rate [%]=(1-A ¹ /A ² ×α)×100...(1)

(In the formula (1), A ¹ is the peak area of the proton derived from the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the other proton relative to the polymer The ratio of the number of protons of the NH group in (polyglycine).)

[weight average molecular weight of polymer]

The weight average molecular weight is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.

Pipe column: manufactured by Tosoh (stock), TSKgelGRCXLII

Solvent: tetrahydrofuran

Temperature: 40 ° C

Pressure: 68kgf/cm ²

[epoxy equivalent]

The epoxy group was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105. the amount.

<Synthesis of Polymer (A)>

[Synthesis Example 1: Synthesis of Polyimine (PI-1)]

22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 8.6 g (0.08 mol) and 3,5- of p-phenylenediamine as a diamine. 10.5 g (0.02 mol) of cholesteryl diaminobenzoate, dissolved in 166 g of N-methyl-2-pyrrolidone (NMP), and reacted at 60 ° C for 6 hours to obtain polyglycine 20 % by weight solution. A small amount of the obtained polyaminic acid solution was added, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the obtained solution viscosity was 90 mPa. s.

Then, NMP was added to the obtained polyaminic acid solution to prepare a solution having a polyglycine concentration of 7 wt%, and 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system is subjected to solvent replacement by a new NMP (by this operation, the pyridine and acetic anhydride used in the dehydration ring-closure reaction are removed to the outside of the system; the same applies hereinafter), thereby obtaining a ruthenium-containing A solution of about 26% polyethylenimine (PI-1) 26% by weight. A small amount of the obtained polyimine solution was added, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight, and the obtained solution viscosity was 45 mPa. s. Then, the reaction solution was poured into a large amount of excess methanol to precipitate a reaction product. The precipitate was washed with methanol, and dried at 40 ° C for 15 hours under reduced pressure to obtain a polyimine (PI-1).

[Synthesis Example 2: Synthesis of Polyimine (PI-2)]

24.9 g (0.10 mol) of 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride as tetracarboxylic dianhydride as a diamine Benzene diamine 8.6 g (0.08 mol) and 3,5-diaminobenzoic acid cholesteryl ester 10.4 g (0.02 mol), dissolved in 176 g of NMP, and reacted at 60 ° C for 6 hours to obtain A solution containing 20% by weight of polyamidamine. A small amount of the obtained polyaminic acid solution was added, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the obtained solution viscosity was 103 mPa. s.

Then, NMP was added to the obtained polyaminic acid solution to prepare a solution having a polyglycine concentration of 7 wt%, and 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was subjected to solvent replacement using a new NMP, thereby obtaining a solution containing 26% by weight of polyimine (PI-2) having a ruthenium iodide ratio of about 71%. A small amount of the obtained polyimine solution was added, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight, and the obtained solution viscosity was 57 mPa. s. Then, the reaction solution was poured into a large amount of excess methanol to precipitate a reaction product. The precipitate was washed with methanol, and dried at 40 ° C for 15 hours under reduced pressure to obtain a polyimine (PI-2).

[Synthesis Example 3: Synthesis of Polyimine (PI-3)]

22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 3-(2,4-diaminophenoxy)cholesterium as diamine 14.8 g (0.03 mol) of alkane, 2-(2,4-diaminophenoxy)ethyl methacrylate (compound represented by the following formula (R-2)) 4.73 g (0.02 mol), And 13.3 g (0.05 mol) of 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine was dissolved in 221 g of NMP. The reaction was carried out at 60 ° C for 6 hours to obtain a solution containing 20% by weight of polyamic acid. liquid. A small amount of the obtained polyamic acid solution was added, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the obtained solution viscosity was 92 mPa. s.

Then, NMP was added to the obtained polyaminic acid solution to prepare a solution having a polyglycine concentration of 7% by weight, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was subjected to solvent replacement using a new NMP, whereby a solution containing 25% by weight of polyimine (PI-3) having a ruthenium iodide ratio of about 48% was obtained. A small amount of the obtained polyimine solution was added, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight, and the measured solution viscosity was 47 mPa. s. Then, the reaction solution was poured into a large amount of excess methanol to precipitate a reaction product. The precipitate was washed with methanol, and dried at 40 ° C for 15 hours under reduced pressure to obtain a polyimine (PI-3).

[Synthesis Example 4: Synthesis of polyaminic acid (PA-1)]

200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, 2,2'-dimethyl-4,4'-di as diamine 210 g (1.0 mol) of aminobiphenyl was dissolved in a mixed solvent of 370 g of NMP and 3,300 g of γ-butyrolactone, and reacted at 40 ° C for 3 hours to obtain a solid concentration of 10% by weight and a solution viscosity. It is 160mPa. s polylysine solution. Then, injecting the polyaminic acid solution into the large In the excess methanol, the reaction product was precipitated. The precipitate was washed with methanol, and dried at 40 ° C for 15 hours under reduced pressure, thereby obtaining polylysine (PA-1).

[Synthesis Example 5: Synthesis of polyproline (PA-2)]

The compound (r1) represented by the following formula (R-1) which is a diamine as a tetracarboxylic dianhydride, 7.0 g (0.031 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, and 13 g of diamine (1 mol of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, equivalent to 1 mol), dissolved in 80 g of NMP, and reacted at 60 ° C for 4 hours, thereby obtaining a polypeptone A 20% by weight solution of aminic acid (PA-3). The solution viscosity of the polyaminic acid solution is 2,000 mPa. s. Further, the compound (r1) is synthesized in accordance with the description of JP-A-2011-100099. Then, the polyamic acid solution was poured into a large amount of excess methanol to precipitate a reaction product. The precipitate was washed with methanol, and dried at 40 ° C for 15 hours under reduced pressure, thereby obtaining polylysine (PA-2).

[Synthesis Example 6: Synthesis of Polylysine (PA-3)]

In a 50 ml four-necked flask equipped with a stirring device and a nitrogen introduction tube, 1,3-bis(4-aminophenethyl)urea (1,3-bis(4-aminophenethyl)urea, BAPU) was added as a diamine. 0.60 g (2.0 mmol) and 1.95 g (18.0 mmol) of p-phenylene diamine (p-PDA), and 30 g of N,N,2-trimethylpropionamide were added. The mixture was stirred while stirring to carry out nitrogen gas. While stirring the diamine solution, 3.70 g (18.9 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride was added, and the solid content concentration was 12% by weight. N,N,2-trimethylpropionamide was added in a manner, and stirred at room temperature for 4 hours under a nitrogen atmosphere to obtain a solution of polyglycine (PA-3).

[Synthesis Example 7: Synthesis of polyaminic acid (PA-4)]

19.61 g (0.1 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 4,4'-diaminodiphenylamine as diamine (4) 4'-DADPA) 18.73 g (0.094 mol), which was mixed with 345.1 g of N,N,2-trimethylpropionamide, and reacted at room temperature for 5 hours. The polymerization reaction was carried out easily and uniformly to obtain poly-proline (PA-4).

[Synthesis Example 8: Synthesis of polyaminic acid (PA-5)]

14.64 g (0.072 mol) of 2,4-diamino-N,N-diallylphenylamine as a diamine, 2.96 g (0.016 mol) of n-dodecylamine as a monoamine, and tetracarboxylic acid 15.69 g (0.08 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride of acid dianhydride in 300 g of N,N,2-trimethylpropionamide at room temperature for 4 hours The reaction was carried out to obtain a solution of polyamic acid (PA-5).

[Synthesis Example 9: Synthesis of polyproline (PA-6)]

10.36 g of bis[2-(4-aminophenyl)ethyl]hexanedioic acid as a diamine, and 19.63 g of pyromellitic dianhydride as a tetracarboxylic dianhydride, in N, N, 2- 170 g of trimethylpropionamide was reacted at room temperature for 4 hours to obtain a solution of polyglycine (PA-6).

[Synthesis Example 10: Synthesis of polyaminic acid (PA-7)]

11.88 g of bis[2-(4-aminophenyl)ethyl]adipate as a diamine, 6.8 g of a compound represented by the following formula (R-3), and 1, as a tetracarboxylic dianhydride, 11.27 g of 2,3,4-cyclobutanetetracarboxylic dianhydride, reacted in 170 g of N,N,2-trimethylpropionamide at room temperature for 4 hours to obtain poly-proline (PA- 7) solution.

[Synthesis Example 11: Synthesis of polyorganosiloxane (APS-1)]

In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux cooling tube, 2-(3,4-epoxycyclohexyl)ethyltrimethoxynonane (2-(3,4-epoxycyclohexyl)ethyl trimethoxy) was charged. 100.0 g of silane, ECETS), 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were mixed at room temperature. Then, 100 g of deionized water was added dropwise from the dropping funnel for 30 minutes, and then the reaction was carried out at 80 ° C for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out and washed with a 0.2% by weight aqueous solution of ammonium nitrate until the water after washing became neutral, and then the solvent and water were distilled off under reduced pressure to obtain reactivity as a viscous transparent liquid. Polyorganosiloxane (EPS-1). ¹ H-NMR (Nuclear Magnetic Resonance Spectroscopy) analysis of the reactive polyorganosiloxane, and the epoxy group-based peak was obtained as the theoretical intensity in the vicinity of the chemical shift (δ)=3.2 ppm. A side reaction in which no epoxy group was produced in the reaction was confirmed. The resulting reactive polyorganosiloxane had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g/mole.

Then, 10.0 g of a reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, and 4-dodecyloxy group as a reactive compound were placed in a 200 mL three-necked flask. 3.98 g of benzoic acid and 0.10 g of UCAT 18X (trade name, manufactured by San-Apro Co., Ltd.) as a catalyst were reacted at 100 ° C for 48 hours while stirring. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, and the organic layer was dried over magnesium sulfate, and the solvent was distilled off to obtain a liquid crystal-aligned polyorganosiloxane (APS-1). 9.0g. The obtained polymer had a weight average molecular weight Mw of 9,900.

. Resistance to precipitation test

[Example 1]

0.5 g of the polymer (PI-1) obtained in Synthesis Example 1 and 4.5 g of N-methyl-2-pyrrolidone were mixed and dissolved. The solvent (hereinafter referred to as the second solvent) described in the following Table 1 was added thereto until the polymer was precipitated, and it was visually judged that the polymer was precipitated at the stage where the solution was cloudy. The evaluation of the precipitation resistance test was carried out as follows: the case where no polymer was precipitated was evaluated as "good", and the case where 5 g or more of the second solvent was added and precipitated was evaluated as "OK", and the second addition of less than 5 g was added. The case where the solvent was precipitated was evaluated as "not possible". As a result, N,N,2-trimethylpropionamide was "good" in precipitation resistance.

[Example 2 to Example 8]

The precipitation resistance test was carried out by the same method as that of Example 1 except that the type of the second solvent to be used was changed to the following Table 1. The results are shown together in Table 1 below.

. Preparation and evaluation of liquid crystal alignment agent

[Example 9A]

<Preparation of liquid crystal alignment agent>

100 parts by weight of the polyimine (PI-1) obtained in Synthesis Example 1 of the polymer (A) was dissolved in N,N,2-trimethylpropionamide (p1) and butyl cellosolve ( A mixed solvent of butyl cellosolve (BC) (solvent composition: p1: BC = 50:50 (weight ratio)) was used to prepare a solution having a solid concentration of 6.5% by weight. This solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal alignment agent (S-1). Further, the liquid crystal alignment agent (S-1) is mainly used for producing a vertical alignment type liquid crystal display element.

<Printability evaluation 1 (160 ° C)>

For the liquid crystal alignment agent (S-1) prepared above, a filter of 1.0 μm was used. After filtering, it was applied to a transparent electrode surface of a glass substrate having a transparent electrode including an ITO film using a liquid crystal alignment film printer (manufactured by Nippon Photoprint Co., Ltd.). Then, it was heated (prebaked) on a hot plate at 80 ° C for 1 minute to remove the solvent, and then heated (post-baked) on a hot plate at 160 ° C for 10 minutes to form a coating film having an average film thickness of 600 Å, and it was found. Whether the viscosity of the coating film is present or not. The coating film was observed with a microscope having a magnification of 20 times, and the unevenness of printing and the presence or absence of pinholes were ascertained. The evaluation was carried out in such a manner that the unevenness of printing and the fact that the pinholes were not observed were evaluated as good printability (○), and at least any of the adhesiveness or the unevenness of the printing and the pinhole were observed. The case of one was evaluated as poor printability (×). As a result, the printability (160 ° C) of the liquid crystal alignment agent was "good".

<Printability evaluation 2 (220 ° C)>

In the liquid crystal alignment agent (S-1) prepared as described above, the heating temperature at the time of post-baking was changed from 160 ° C to 220 ° C, and evaluation was performed in the same manner as the "evaluation evaluation 1". . As a result, the printability (220 ° C) of the liquid crystal alignment agent was "good".

[Example 10A to Example 15A and Comparative Example 1A]

The liquid crystal alignment agent (S-2) was prepared by the same method as that of the above-mentioned Example 9A except that the type and composition of the polymer (A) and the solvent to be used were changed as described in Table 2 below. Liquid crystal alignment agent (S-7) and liquid crystal alignment agent (SR-1). Further, the evaluation of printability was carried out in the same manner as in the above-described Example 9A. The results are shown in Table 2 below. Further, in Table 2, the compounding ratio of the polymer (A) represents 100% by weight relative to the total amount of the polymer contained in the liquid crystal alignment agent. The content (% by weight) of each polymer. In addition, the liquid crystal alignment agent (S-1) to liquid crystal alignment agent (S-3) is mainly used for manufacturing a vertical alignment type liquid crystal display element, and the liquid crystal alignment agent (S-4) is mainly used for manufacturing a vertical alignment type by photoalignment method. Liquid crystal display element, liquid crystal alignment agent (S-5) ~ liquid crystal alignment agent (S-6), liquid crystal alignment agent (SR-1) is mainly used for manufacturing IPS type or FFS type liquid crystal display elements, liquid crystal alignment agent (S-7) It is mainly used for TN type liquid crystal display elements.

Further, the symbols of the solvent compositions in Table 2 have the following meanings, respectively.

a: N, N, 2-trimethylpropanamide

b: butyl cellosolve

c: diacetone alcohol

d: N-methyl-2-pyrrolidone

As shown in Table 2, the liquid crystal alignment agent of the examples had good printability at a baking temperature of 160 ° C and 220 ° C. On the other hand, the liquid crystal alignment agent of the comparative example was 160 At the baking temperature of °C, the coating film has viscosity and poor printability. Therefore, it can be said that the liquid crystal alignment agent of the embodiment can sufficiently dissolve the polyimine or polylysine or the like, and can form the liquid crystal alignment film by heating at a relatively low temperature.

[Example 16A to Example 20A]

The liquid crystal alignment agent (S-8) was prepared by the same method as that of the above-mentioned Example 9A except that the type and composition of the polymer (A) and the solvent to be used were changed as described in Table 3 below. Liquid crystal alignment agent (S-12). Further, the evaluation of printability was carried out in the same manner as in the above-described Example 9A. The results are shown in Table 3 below. In addition, in Table 3, the compounding ratio of the polymer (A) shows the content (% by weight) of 100% by weight of the total amount of the polymer of the polymer contained in the liquid crystal alignment agent. In addition, the liquid crystal alignment agent (S-9) is mainly used for manufacturing a vertical alignment type liquid crystal display element, and a liquid crystal alignment agent (S-8), a liquid crystal alignment agent (S-10), and a liquid crystal alignment agent (S-11) are mainly used for An IPS type or FFS type liquid crystal display element is manufactured, and a liquid crystal alignment agent (S-12) is mainly used for manufacturing an IPS type or FFS type liquid crystal display element by the optical alignment method.

Further, the symbols of the solvent compositions in Table 3 have the following meanings, respectively. In addition, The same symbols as in Table 2 mean the same compounds as in Table 2.

e: diethylene glycol diethyl ether

f: diisobutyl ketone

i: γ-butyrolactone

As shown in Table 3, the liquid crystal alignment agents of Examples 16A to 20A exhibited good printability at a baking temperature of 160 ° C and 220 ° C.

[Example 9B]

<Preparation of liquid crystal alignment agent>

Using the same solvent composition as in Example 9A, the solution viscosity was 6 mPa. The polymer solution was separately prepared by the method of s, and the liquid crystal alignment agent (S-1a) was prepared by filtration using a 0.2 μm filter. The liquid crystal alignment agent (S-1a) was provided for evaluation of inkjet coating properties.

<Evaluation of Surface Concavity of Coating Film>

The coating film obtained in the evaluation of the printability evaluation 2 (220 ° C) of the Example 9A was observed by an atomic force microscope (AFM), and the center average roughness (Ra) was measured. The evaluation was carried out in such a manner that the case where Ra was less than 10 nm was evaluated as "good" surface unevenness, and the case of 10 nm or more and less than 15 nm was evaluated as "OK", and the case of 15 nm or more was evaluated as "poor". In addition, when a solvent having good solubility in a polymer is used, the surface tension of the coating film increases, and the leveling property (surface unevenness) of the coating film tends to decrease. On the other hand, from the viewpoint of obtaining a good film, the liquid crystal alignment agent preferably has a low surface tension and good solubility in a polymer. In this embodiment, the surface unevenness is "good" the result of.

<Evaluation of inkjet coating property>

The glass substrate with the transparent electrode containing ITO was heated on a hot plate of 200 ° C for 1 minute, and then ultraviolet/ozone cleaning was performed, and the contact angle of water of the transparent electrode surface was set to 10 or less, and it was used as a substrate immediately. . The liquid crystal alignment agent (S-1a) prepared above was applied onto the transparent electrode surface of the glass substrate with a transparent electrode using an inkjet coater (manufactured by Shibaura Mechatronics Co., Ltd.). The coating conditions at this time were as follows: 2 round trips (total 4 times) were carried out at 2,500 times / (nozzle. minute) and discharge amount of 250 mg / 10 seconds. After coating, it was allowed to stand for 1 minute, and then heated at 80 ° C to form a coating film having an average film thickness of 0.1 μm. The obtained coating film was observed with the interference of the interference fringe lamp (sodium lamp), and the case where both unevenness and repulsion were not observed was evaluated as "good" inkjet coating property, and unevenness was observed. In the case of at least one of the repulsion, the inkjet coating property was "poor", and as a result, the inkjet coating property of the liquid crystal alignment agent was "good".

[Example 10B to Example 20B and Comparative Example 1B]

With respect to the liquid crystal alignment agent (S-2) to the liquid crystal alignment agent (S-12) and the liquid crystal alignment agent (SR-1), the surface unevenness was evaluated in the same manner as in the above-described Example 9B. The results are shown in Table 4 below.

[Comparative Example 2B]

In addition to dissolving the solvent used in a mixed solvent containing NMP, propylene carbonate (PC) and butyl cellosolve (BC) (solvent composition: NMP: PC: BC = 40:30:30 (weight ratio)) In addition to the aspects, the same party as the above-described embodiment 9A A liquid crystal alignment agent (SR-2) was prepared. Further, the surface unevenness of the coating film was evaluated in the same manner as in the above-described Example 9B. The results are shown in Table 4 below.

As shown in Table 4, the evaluation of the surface unevenness of the liquid crystal alignment agent of the examples was "good" or "may". On the other hand, in Comparative Example 2B in which the compound (p1) was not contained as a solvent component, the surface unevenness was evaluated as "poor". According to the above experimental results, the liquid crystal alignment agent of the examples has both the solubility (precipitation resistance) of the polymer and the leveling property (surface unevenness) of the coating film, and the printing property is good even at low-temperature baking. On the other hand, the liquid crystal alignment agent of the comparative example had poor printability at low temperature firing or poor uniformity of the coating film.

[Example 21: retardation film]

(1) Preparation of liquid crystal alignment agent

100 parts by weight of the polymer (PA-7) obtained in Synthesis Example 10 was dissolved in a mixed solvent containing N,N,2-trimethylpropionamide (DMIB) and butyl cellosolve (BC) (DMIB: BC = 60:40 (weight ratio)), the solid content concentration is 5 Amount of solution. This solution was filtered using a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent.

(2) Fabrication of retardation film

The liquid crystal alignment agent prepared above was applied to one surface of the TAC film as a substrate by a bar coater, and baked at 120 ° C for 2 minutes in an oven to form a coating film having a film thickness of 100 nm. Then, on the surface of the coating film, a polarized ultraviolet ray of 500 mJ/cm ² containing an open line of 254 nm was vertically irradiated from the substrate normal line using an Hg-Xe lamp and a Glan-Taylor prism. Then, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck) was filtered through a filter having a pore size of 0.2 μm, and then the polymerizable liquid crystal was applied onto the coating film after light irradiation by a bar coater to form polymerizability. Liquid crystal coating film. After baking for 1 minute in an oven adjusted to a temperature of 50 ° C, a non-polarized ultraviolet ray of 1,000 mJ/cm ² containing a bright line of 365 nm was irradiated from the vertical direction using a Hg-Xe lamp to polymerize. The liquid crystal is hardened to form a liquid crystal layer, thereby producing a retardation film.

(3) Evaluation of liquid crystal alignment

With respect to the retardation film produced in the above (2), the presence or absence of an abnormal region was observed by a visual observation under a crossed nicols and a polarizing microscope (magnification: 2.5 times), thereby evaluating liquid crystal alignment (light) Orientation). The evaluation was carried out in the following manner: when the visual alignment was good and the abnormal region was not observed under the polarizing microscope, the liquid crystal alignment property was evaluated as "good"; no abnormal region was observed when visually observed, but abnormality was observed under a polarizing microscope. The case of the region was evaluated as "liquid crystal alignment"; the case where the abnormal region was observed under both the visual and polarizing microscopes was evaluated as liquid crystal matching. Directionality is "bad". As a result, the retardation film was evaluated as having a good liquid crystal alignment property.

(4) Adhesion

The adhesion between the coating film formed of the liquid crystal alignment agent and the substrate was evaluated using the retardation film produced in the above (2). First, an equally spaced separator having a guide was used, and a slit was cut from the surface on the liquid crystal layer side of the retardation film by a cutter knife to form 10 × 10 lattice patterns. The depth of each slit is set to reach half of the thickness of the substrate from the surface of the liquid crystal layer. Then, the cellophane tape is adhered to cover the entire surface of the lattice pattern, and then the cellophane tape is peeled off. The notch portion of the lattice pattern after peeling was observed by visual observation under crossed Nicols, and the adhesion was evaluated. The evaluation was carried out in such a manner that the peeling was not confirmed in the portion where the tangent line and the lattice pattern were not separated, and the adhesion was "good"; the peeling was observed in the portion with respect to the total number of the lattice patterns. When the number of the lattices is less than 15%, the adhesion is "corresponding". When the number of the lattices observed in the portion is 15% or more, the number of the lattice patterns is 15% or more. "bad". As a result, the retardation film was "good" in adhesion.

Claims (10)

A liquid crystal alignment agent comprising: at least one polymer (A) selected from the group consisting of polyphthalic acid, polyamidiamine, polyphthalate, and polyorganosiloxane; and a solvent of the compound (p1) represented by the formula (1); (In the formula (1), R ¹ to R ⁴ are each independently a linear or branched hydrocarbon group having 1 to 6 carbon atoms or a group selected from -O-, -COO- and between CC bonds of the hydrocarbon group; a group of at least one of -OCO-). The liquid crystal alignment agent according to claim 1, wherein the content of the compound (p1) is 5% by weight or more based on the total amount of the solvent. The liquid crystal alignment agent according to claim 1 or 2, which comprises polyamic acid, polyimine, and polyamine obtained by reacting tetracarboxylic dianhydride with a diamine. At least one of the groups consisting of esters as the polymer (A), the tetracarboxylic dianhydride comprising selected from 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2, 4, 6, 8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.1]heptane- 2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, 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 At least one of a group consisting of -1,3-diketone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, and pyromellitic dianhydride. A liquid crystal alignment film which is formed using the liquid crystal alignment agent according to any one of claims 1 to 3. A liquid crystal display element comprising the liquid crystal alignment film according to item 4 of the patent application. A retardation film comprising the liquid crystal alignment film according to item 4 of the patent application. A liquid crystal alignment film obtained by applying a liquid crystal alignment agent according to any one of the first to third aspects of the invention to a substrate to form a coating film, which is produced by irradiating the coating film with light. A method for producing a liquid crystal alignment film, comprising: forming a liquid crystal alignment agent according to any one of claims 1 to 3 on a substrate; and irradiating the coating film with light to impart a liquid crystal The steps of the alignment capability. A method for producing a liquid crystal alignment agent comprising: synthesizing, in an organic solvent comprising a compound (p1) represented by the following formula (1), a compound selected from the group consisting of polylysine, polyimine, and polyphthalate a step of at least one polymer in the group; and a step of producing a liquid crystal alignment agent containing the polymer obtained by the synthesis, and a compound represented by the following formula (1) (p1) Solvent; (In the formula (1), R ¹ to R ⁴ are each independently a linear or branched hydrocarbon group having 1 to 6 carbon atoms or a group selected from -O-, -COO- and between CC bonds of the hydrocarbon group; a group of at least one of -OCO-). A method for producing a retardation film, comprising: a step of applying a liquid crystal alignment agent according to any one of claims 1 to 3 to a substrate to form a coating film; and performing the coating film a step of irradiating light; and a step of applying a polymerizable liquid crystal to the coating film after the light irradiation to harden it.