KR20130086270A - Liquid crystal aligning agent, method for forming liquid crystal alignment film, the liquid crystal alignment film, and liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal aligning agent is provided to form a liquid crystal alignment film with excellent liquid crystal alignment by having high radiosensitivity and low intensity radiation. CONSTITUTION: A liquid crystal aligning agent contains a polymer with a structure unit including a structure represented by chemical formula 1. In chemical formula 1, R^1 is a hydrogen atom, a C1-10 alkyl group, or a C3-10 cycloalkyl group; Ar^1 is a group including an aromatic ring; and * is a group capable of being coupled to the hydrogen atom or another group. A forming method of a liquid crystal alignment film comprises a step of forming a coating on a substrate by using the liquid crystal aligning agent; and a step of forming the liquid crystal alignment film by a light irradiation.

Description

Liquid crystal aligning agent for photoalignment, the formation method of a liquid crystal aligning film, a liquid crystal aligning film, and a liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENT, METHOD FOR FORMING LIQUID CRYSTAL ALIGNMENT FILM, THE LIQUID CRYSTAL ALIGNMENT FILM, AND LIQUID CRYSTAL DISPLAY DEVICE}

This invention relates to the liquid crystal aligning agent for photo-alignments, the formation method of a liquid crystal aligning film, a liquid crystal aligning film, and a liquid crystal display element.

BACKGROUND ART Liquid crystal displays (LCDs) are widely used in televisions and various monitors. As the display element of this LCD, there are liquid crystal cells such as TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, and IPS (In Plane Switching) type, and the electrode structure of liquid crystal cells such as IPS type is changed and displayed. FFS (Fringe Field Switching) type etc. which raise the aperture ratio of an element part and improve brightness are also known (refer Unexamined-Japanese-Patent No. 56-91277 and Unexamined-Japanese-Patent No. 1-20528).

As a method of orienting the liquid crystal of such a liquid crystal cell, the method by the rubbing process which forms an organic film in the surface of a board | substrate, and rubs the surface of the organic film in the direction made of cloth, such as rayon, and silicon oxide on the board | substrate surface in all directions Polarizing or photosensitive thin films made of polyvinylcinnamate, polyimide resin, polyamic acid, or the like, by forming a short-molecular film having a long-chain alkyl group by using a vapor deposition method, a Langmuir blowjet method (LB method), or the like. Optical alignment method for imparting liquid crystal alignment capability by irradiating non-polarized radiation (see Japanese Patent Laid-Open No. 6-287453, Japanese Patent Laid-Open No. 2003-307736 and Japanese Patent Laid-Open No. 9-297313) Etc. are known. Among these, development of the said optical orientation method which can implement | achieve a uniform liquid crystal orientation without generating static electricity and dust, and can control a liquid crystal orientation direction precisely is progressing. According to this photo-alignment method, by using a photomask or the like at the time of radiation irradiation, it is possible to arbitrarily form a plurality of regions having different liquid crystal alignment directions on one substrate. However, since the photosensitive thin film which consists of conventional polyimide resin, polyamic acid, etc. has insufficient sensitivity, there exists a problem that a large accumulated exposure amount is needed in order to provide liquid-crystal orientation. Moreover, the liquid crystal aligning property of the liquid crystal aligning film obtained from the said photosensitive thin film is not necessarily enough. Moreover, the agent performances, such as an electrical characteristic, an afterimage characteristic, of a liquid crystal display element provided with such a liquid crystal aligning film, are not fully satisfactory.

Japanese Laid-Open Patent Publication No. 56-91277 Japanese Unexamined Patent Application Publication No. 1-120528 Japanese Patent Laid-Open No. 6-287453 Japanese Patent Application Laid-Open No. 2003-307736 Japanese Patent Laid-Open No. 9-297313

The objective of this invention is providing the liquid crystal aligning agent for photoalignments which can form the liquid crystal aligning film which has sufficient liquid crystal alignability while being excellent in radiation sensitivity. Moreover, it provides a liquid crystal aligning film using the liquid crystal aligning agent for such photo-alignment, its formation method, and also this liquid crystal aligning film, and is excellent also in the performance of electrical characteristics, an afterimage characteristic, etc.

According to an aspect of the present invention,

(A) It is a liquid crystal aligning agent for photoalignments containing the polymer (henceforth a [A] polymer) which has a structural unit (I) containing the structure represented by following formula (1):

(In formula (1), R <^1> is a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group; Ar <^1> is a group containing an aromatic ring; * is a hydrogen atom or another group Indicates the site of binding).

Since the radiation sensitivity improves by containing the [A] polymer which has the specific structure of said Formula (1), the liquid crystal aligning agent for photo-alignments of this invention makes the liquid crystal aligning film which has the outstanding liquid-crystal orientation with a low irradiation amount. Can be formed. Moreover, the reason why radiation sensitivity improves is not necessarily clear, because the said liquid crystal aligning agent for photo-alignment contains the [A] polymer containing the said specific structure, For example, it is estimated as follows. Particular structural moieties in which a carbon atom bonded to an imide group and an aromatic ring-containing group, as represented by the above formula (1), are easily broken due to irradiation, so that decomposition of the main chain of the polymer [A], etc. It is conceivable that photo-alignment due to polarization occurs with high sensitivity due to being easy to occur. As a result, when the said liquid crystal aligning agent for photo-alignments is used, it can be considered that the outstanding photo-alignment in a smaller irradiation amount is attained. Moreover, when the liquid crystal aligning film formed with the said liquid crystal aligning agent for photoalignments is used, the liquid crystal display element excellent in the electrical performance, the afterimage characteristic, etc. can be manufactured.

The polymer (A) is preferably polyamic acid (hereinafter referred to as "polyamic acid (A1)") or polyimide (hereinafter referred to as "polyimide (A2)"). Here, a polyamic acid is a polymer which has a structural unit containing a dark acid structure, and the said dark acid structure does not imidize, and means the polymer whose imidation ratio is 0%. In addition, a polyimide means the polymer which the at least 1 of the dark acid structure which the said polyamic acid has imidated.

As said structural unit (I), the structural unit represented by following formula (2) or formula (3) is preferable:

(In formula (2) and (3), R <^1> and Ar <^1> are synonymous with said Formula (1); R <^2> and R <^3> is respectively independently tetravalent organic group.

When the [A] polymer has the structural unit (I) of the said specific structure, the said liquid crystal aligning agent for photo-alignment improves a radiation sensitivity, and can be equipped with more excellent photo-alignment property.

The polymer (A) is a reaction between a diamine component (hereinafter also referred to as "[a] diamine component") containing a diamine compound represented by [a] Formula (4) below and a [b] tetracarboxylic dianhydride component It is preferable that it is at least 1 sort (s) of polymer chosen from the group which consists of the polyamic acid obtained by the polyimide obtained by dehydrating and ring-closing this polyamic acid:

(In formula (4), R <^1> and Ar <^1> is synonymous with said Formula (1).).

The said liquid crystal aligning agent for photo-alignments improves photo-alignment property because the [A] polymer is polyamic acid and / or polyimide obtained by reaction of a [a] diamine component and a [b] tetracarboxylic dianhydride component. Therefore, the liquid crystal aligning film excellent in liquid crystal aligning property can be formed. Moreover, when using such a liquid crystal aligning film, the liquid crystal display element excellent in manufacturing performance, such as an electrical characteristic and an afterimage characteristic, can be manufactured.

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

(In Formula (5), Y is group containing an aromatic ring or alicyclic; X <^1> and X <^2> are respectively independently a single bond, -O-, -S-, or -NH-).

Since the polymer (A) is a polyamic acid obtained by the reaction of the [a] diamine component and the [b] tetracarboxylic dianhydride component of the said specific structure, the said liquid crystal aligning agent for photo-alignments can improve a radiation sensitivity more. Can be. Moreover, the liquid crystal aligning film obtained from the said liquid crystal aligning agent for photoalignments is further excellent in liquid crystal orientation. Moreover, when using such a liquid crystal aligning film, the liquid crystal display element excellent in manufacturing performance, such as an electrical characteristic and an afterimage characteristic, can be manufactured.

The formation method of the liquid crystal aligning film of this invention,

(1) forming a coating film on a substrate using the liquid crystal aligning agent for photoalignment of the present invention, and

(2) Process of forming a liquid crystal aligning film by irradiating light to the said coating film

.

According to the formation method of this invention, since the said liquid crystal aligning agent for photo-alignments is used, the liquid crystal aligning film excellent in liquid crystal aligning property can be formed with a small exposure amount. Moreover, by using such a liquid crystal aligning film, the liquid crystal display element which fully satisfy | fills the performance of electrical characteristics, an afterimage characteristic, etc. can be manufactured.

This invention also includes the liquid crystal aligning film formed with the said liquid crystal aligning agent for photo-alignments. Since the liquid crystal aligning film of this invention is formed with the said liquid crystal aligning agent for photo-alignments, in the formation process, liquid crystal aligning ability can be provided by the radiation of a low irradiation amount, production efficiency is good and manufacturing cost is also reduced. can do. Moreover, since the said liquid crystal aligning film is excellent in liquid crystal aligning property, the liquid crystal display element provided with the said liquid crystal aligning film fully satisfies manufacturing performance, such as an electrical characteristic and an afterimage characteristic.

The liquid crystal display element of this invention is equipped with the said liquid crystal aligning film. Since the said liquid crystal aligning film is excellent in liquid crystal aligning property, the said liquid crystal display element provided with the said liquid crystal aligning film fully satisfies manufacturing performance, such as an electrical characteristic and an afterimage characteristic.

In addition, "light" and "radiation" in "optical alignment use" are used by the same meaning here, and it is a concept containing visible light, an ultraviolet-ray, an ultraviolet-ray, an X-ray, a charged particle beam, etc.

Since the liquid crystal aligning agent for photo-alignments of this invention can form the liquid crystal aligning film which has high radiation sensitivity and excellent liquid crystal aligning property with the radiation of a low irradiation amount, the production efficiency is good and can reduce production cost. Moreover, the liquid crystal display element provided with the said liquid crystal aligning film is excellent in manufacturing performance, such as an electrical characteristic and an afterimage characteristic. Therefore, the liquid crystal aligning agent for photoalignments of this invention, a liquid crystal aligning film, the formation method of this liquid crystal aligning film, and a liquid crystal display element are used suitably for liquid crystal display elements, such as an IPS type and an FFS type.

FIG. 1: is explanatory drawing which shows the electrode pattern of the conductive film in the board | substrate which has the comb-tooth shaped conductive film used in the Example and the comparative example at the time of evaluation of an afterimage characteristic.

(Mode for carrying out the invention)

<Liquid crystal aligning agent for photoalignment>

The liquid crystal aligning agent for photoalignments of this invention contains a [A] polymer. This polymer (A) has structural unit (I) containing the structure represented by said formula (1). Thus, the said liquid crystal aligning agent for photo-alignment contains a [A] polymer which has the said specific structure, and radiation sensitivity improves and it can form the liquid crystal aligning film which has the outstanding liquid-crystal orientation with the radiation of a low irradiation amount. Moreover, the liquid crystal display element provided with this liquid crystal aligning film is excellent in manufacturing performance, such as an electrical characteristic and an afterimage characteristic. The liquid crystal aligning agent for photo-alignment of this invention can contain other components other than the [A] polymer which is an essential component, unless the effect of this invention is impaired. Each component will be described in detail below.

<[A] Polymer>

The polymer (A) is a polymer having a structural unit (I). The polymer (A) is not particularly limited as long as it is a polymer having the structural unit (I), but is preferably polyamic acid (A1) or polyimide (A2). When the polymer (A) is polyamic acid (A1) or polyimide (A2) having a structural unit (I), the liquid crystal aligning agent for photoalignment can form a liquid crystal alignment film having more excellent liquid crystal alignment. Moreover, in the range which does not impair the effect of this invention, a polymer [A] may have other structural units in addition to a structural unit (I).

[Structural unit (I)]

Structural unit (I) contains the structure represented by said formula (1).

In said formula (1), R <^1> is a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group. Ar ¹ is a group containing an aromatic ring. * Represents a site bonded to a hydrogen atom or another group.

As a C1-C10 alkyl group and C3-C10 cycloalkyl group represented by said R <^1> , a methyl group, an ethyl group, a propyl group, a butyl group, a cyclopropyl group, a cyclobutyl group, etc. are mentioned, for example. Among these, methyl group and ethyl group are preferable.

As said R <^1> , a hydrogen atom, a methyl group, and an ethyl group are preferable, and a hydrogen atom is more preferable.

As group containing the aromatic ring represented by said Ar <^1> , For example, the group represented by following formula (a), this group, and at least selected from the group which consists of -COO-, -NH-, -O-, and -S- The group etc. which consist of combining 1 type of group are mentioned.

In said formula (a), R ^<A> and R <^B> are respectively independently a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group. n is an integer of 0-5. When n is two or more, some R ^<A> and R <^B> may be same or different, respectively. Ar <^2> is a C6-C20 aryl group. * Represents the site | part couple | bonded with the carbon atom which R <^1> couple | bonds in said Formula (1).

As a C1-C10 alkyl group and C3-C10 cycloalkyl group represented by said R ^<A> and R <^B> , the group similar to what was illustrated as each group represented by said R <^1> is mentioned, for example.

As said R ^<A> and R <^B> , a hydrogen atom, a methyl group, and an ethyl group are preferable, and a hydrogen atom is more preferable.

As said n, an integer of 0-2 is preferable, 0 or 1 is more preferable, and 0 is still more preferable from a viewpoint of heightening the sensitivity of the said liquid crystal aligning agent for photo-alignments more.

As said C6-C20 aryl group, a phenylene group, a naphthylene group, an anthylene group, etc. are mentioned, for example. Among these, a phenylene group and a naphthylene group are preferable, and a phenylene group is more preferable.

As a group which combines the said C6-C20 aryl group and at least 1 group chosen from the group which consists of -COO-, -NH-, -O-, and -S-, For example, a phenylene group and -COO- And groups formed by combining at least one group selected from the group consisting of -NH-, -O- and -S-. Among these, the group which combines a phenylene group and -COO- is preferable.

As said Ar <^1> , the group containing the aromatic ring couple | bonded directly with the carbon atom which R <^1> couple | bonds is preferable, and is made by combining the phenylene group, the naphthylene group, and the phenylene group directly bonded to the said carbon atom -COO-. A group is more preferable, and the group which combines -COO- with the phenylene group and the phenylene group directly bonded to the said carbon atom is more preferable.

Although it will not specifically limit, if it is a structural unit containing the structure represented by said formula (1) as structural unit (I), It is preferable that it is a structural unit represented by said formula (2) or (3).

In said Formula (2) and (3), R <^1> and Ar <^1> are synonymous with said Formula (1). R ² and R ³ are each independently a tetravalent organic group.

As a tetravalent organic group represented by said R <^2> and R <^{3>, it} is for example

Tetravalent aliphatic chain hydrocarbon groups having 1 to 20 carbon atoms;

Tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms;

C6-C20 tetravalent aromatic hydrocarbon group;

At least one group selected from the group consisting of an aliphatic chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 4 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms, and -COO-, -CO-, -O- And groups formed by combining at least one group selected from the group consisting of -S- and -NH-.

As said C1-C20 tetravalent aliphatic chain hydrocarbon group, the group remove | excluding four hydrogen atoms from aliphatic chain hydrocarbons, such as methane, ethane, propane, butane, pentane, hexane, an octane, etc. are mentioned, for example.

Examples of the tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include four hydrogens from alicyclic hydrocarbons such as cyclobutane, cyclopentane, cyclohexane, cyclooctane, bicyclooctane, adamantane and tricyclodecane. The group which removed the atom etc. are mentioned. Among these, groups in which four hydrogen atoms have been removed from cyclobutane, cyclopentane, bicyclooctane, and tricyclodecane are preferable, and groups in which four hydrogen atoms have been removed from cyclopentane are more preferable.

As said C6-C20 tetravalent aromatic hydrocarbon group, the group remove | excluding four hydrogen atoms from aromatic hydrocarbons, such as benzene, naphthalene, anthracene, etc. are mentioned, for example. Among these, groups in which four hydrogen atoms have been removed from benzene are preferable.

At least one group selected from the group consisting of an aliphatic chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 4 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 20 carbon atoms, and -COO-, -CO-, -O C1-C20 aliphatic chain hydrocarbon group, C4-C20 alicyclic hydrocarbon group, and C6-C20 in the group which combines at least 1 group chosen from the group which consists of-, -S-, and -NH- Examples of the aromatic hydrocarbon group include groups in which two or three hydrogen atoms have been removed from the aliphatic chain hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons exemplified above as necessary. Of these, groups formed by combining an aromatic hydrocarbon group having 6 to 20 carbon atoms with at least one group selected from the group consisting of -COO-, -CO-, -O-, -S-, and -NH- are preferably 6 carbon atoms. The group which combines the aromatic hydrocarbon group of -10 and at least 1 group chosen from the group which consists of -COO-, -CO-, -O-, -S-, and -NH- is more preferable, and is C6-C10 aromatic More preferred are groups formed by combining a hydrocarbon group and -COO-.

As said R <^2> and R <^3> , At least 1 sort (s) of group chosen from the group which consists of the said C1-C20 aliphatic chain hydrocarbon group, a C4-C20 alicyclic hydrocarbon group, and a C6-C20 aromatic hydrocarbon group, -COO The group which combines at least 1 sort (s) of group chosen from the group which consists of-, -CO-, -O-, -S-, and -NH- is preferable, The C6-C20 aromatic hydrocarbon group -COO-, -CO- More preferably, the group formed by combining at least one group selected from the group consisting of -O-, -S-, and -NH- is more preferable, and the group formed by combining an aromatic hydrocarbon group having 6 to 10 carbon atoms with -COO- is more preferable. .

The said structural unit (I) superposes | polymerizes the diamine compound and tetracarboxylic dianhydride containing a part of structure represented by said Formula (1), as demonstrated in detail in the synthesis method of the polymer [A] mentioned later. And the like. Moreover, as said diamine compound, the compound represented by said Formula (4) is preferable, and as said tetracarboxylic dianhydride, the compound represented by said Formula (5) is preferable. These compounds are explained in full detail in the method for synthesizing the polymer [A].

As content rate of the structural unit (I) in (A) polymer, 10 mol% or more and 100 mol% or less are preferable, 60 mol% or more and 100 mol% or less are more preferable, 80 mol% or more and 100 mol% or less More preferably, 90 mol% or more and 100 mol% or less are especially preferable. By making the content rate of the structural unit (I) in the [A] polymer into the said specific range, the said liquid crystal aligning agent for photo-alignment can improve a radiation sensitivity more.

[A] The polymer is preferably polyamic acid (A1) or polyimide (A2), and among the polyamic acid (A1) and polyimide (A2), the structural unit (I) of these polymers is represented by the formula (2). ) Or more preferably represented by formula (3).

As polyamic acid (A1), it is preferable that the said structural unit (I) is a polymer represented by said formula (2). Moreover, as polyimide (A2), although it is preferable that the said structural unit (I) is a polymer represented by said Formula (3), as a structural unit (I), in addition to the structural unit represented by said Formula (3), it is said Formula ( You may have the structural unit shown by 2).

[A] As a polymer, the polyamic acid obtained by reaction with the diamine component containing the diamine compound represented by said formula (4), and [b] tetracarboxylic dianhydride component, and this polyamic acid are dehydrated and closed ring. It is preferable that it is at least 1 sort (s) of polymer chosen from the group which consists of polyimide formed. Moreover, as [b] tetracarboxylic dianhydride component, it is preferable that it is a component containing tetracarboxylic dianhydride represented by said Formula (5). In addition, the diamine compound represented by said Formula (4) and the tetracarboxylic dianhydride represented by said Formula (5) are explained in full detail in the synthesis method of [A] polymer.

<Method of synthesizing [A] polymer>

Although the synthesis method of a polyamic acid (A1) and a polyimide (A2) is mentioned below as a synthesis | combining method of the [A] polymer, the synthesis | combining method of the [A] polymer in this invention is limited to these synthesis methods. It is not.

[Synthesis method of polyamic acid (A1)]

Polyamic acid (A1) can be synthesize | combined, for example by making the diamine component and the tetracarboxylic dianhydride component containing the diamine compound containing a part of structure represented by said formula (1) react in an organic solvent.

(Diamine Compound Component)

As a diamine compound which the said diamine compound component contains, the compound represented by said formula (4) is preferable.

In said Formula (4), R <^1> and Ar <^1> are synonymous with said Formula (1).

For R ¹ and Ar ¹ in the formula (4), it is possible to apply the description of R ¹ and Ar ¹ in the formula (1).

As a compound represented by said Formula (4), the compound etc. which are represented by following formula (4-1)-(4-8) are mentioned, for example. In addition, these diamine compounds can be used individually or in combination of 2 or more types.

Among these, the diamine compound represented by said Formula (4-1)-(4-4) and Formula (4-7) is preferable, The diamine compound represented by said Formula (4-1) and Formula (4-7) is More preferably, the diamine compound represented by said formula (4-1) is still more preferable.

In addition, in the synthesis | combination of polyamic acid (A1), you may copolymerize another diamine compound with the diamine compound represented by said formula (4), unless the effect of this invention is impaired.

As another diamine compound, aliphatic diamine, alicyclic diamine, diamino organosiloxane, aromatic diamines other than the aromatic diamine represented by said formula (4), etc. are mentioned, for example. . These other diamine compounds can be used individually or in combination of 2 or more types.

As aliphatic diamine, metaxylenediamine, 1, 3- propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc. are mentioned, for example.

As alicyclic diamine, 1, 4- diamino cyclohexane, 4, 4'- methylenebis (cyclohexylamine), 1, 3-bis (aminomethyl) cyclohexane, etc. are mentioned, for example.

As diamino organosiloxane, 1, 3-bis (3-aminopropyl)-tetramethyl disiloxane, etc. are mentioned, for example, Diamine of Unexamined-Japanese-Patent No. 2010-97188 is mentioned.

As other aromatic diamine, it is p-phenylenediamine, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenyl sulfide, 1, 5- diamino naphthalene, 2,2'-, for example. Dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4'-dia Minodiphenylether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-amino Phenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m -Phenylenediisopropylidene) bisaniline, 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, 3,5-diaminobenzoic acid, dodecaneoxy-2,4-diaminobenzene, tetradecaneoxy-2,4-diaminobenzene, pentadecane Oxy-2,4-diaminobenzene, hexadecaneoxy-2,4-diaminobenzene, octadecaneoxy-2,4-diaminobenzene, dodecaneoxy-2,5-diaminobenzene, tetradecaneoxy- 2,5-diaminobenzene, pentadecaneoxy-2,5-diaminobenzene, hexadecaneoxy-2,5-diaminobenzene, octadecaneoxy-2,5-diaminobenzene, cholestanyloxy-3 , 5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3,5- Diaminobenzoic acid cholestanyl, 3,5-diaminobenzoic acid cholestenyl, 3,5-diaminobenzoic acid ranostanyl, 3,6-bis (4-aminobenzoyloxy) chole Tan, 3,6-bis (4-aminophenoxy) cholestane, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 4- (4'-trifluoro Romethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4- ( (Aminophenyl) methyl) phenyl) -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-aminobenzylamine, 3-aminobenzylamine and The diamine compound etc. which are shown are mentioned.

In said formula, R <^4> is a C1-C3 bivalent alkanediyl group, * -O-, * -COO-, or * -OCO-. Provided that * binds to the diaminophenyl group. r is 0 or 1; s is an integer of 0-2. t is an integer of 1-20.

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

[a] As a content ratio of the diamine compound and other diamine compound represented by said Formula (4) in a diamine component, 100 mol%: 0 mol%-20 mol%: 80 mol% are preferable, and 100 mol%: 0 Mol%-50 mol%: 50 mol% is more preferable.

(Tetracarboxylic acid dianhydride component)

As said tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. are mentioned. In addition to these, tetracarboxylic dianhydride described in Japanese Patent Application No. 2009-157556 can be used. In addition, these tetracarboxylic dianhydride can be used individually or in combination of 2 or more types.

Examples of the aliphatic tetracarboxylic acid dianhydride include butane tetracarboxylic dianhydride.

Examples of the alicyclic tetracarboxylic dianhydride include, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic 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, 3 Oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro- 3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-2 anhydride , 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-2 anhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane- 3,5,8,10-tetraon etc. are mentioned.

As aromatic tetracarboxylic dianhydride, a pyromellitic dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyl sulfontetracarbon, for example Acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid dianhydride, tetracarboxylic acid 2 described in Japanese Patent Application No. 2010-97188 Anhydride, the aromatic tetracarboxylic dianhydride represented by said formula (5), etc. are mentioned.

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

As group containing the aromatic ring represented by said Y, the C6-C20 bivalent aromatic hydrocarbon group, the group in which the several C6-C20 aromatic ring couple | bonded with the single bond or the divalent organic group, etc. are mentioned, for example. have.

As said C6-C20 bivalent aromatic hydrocarbon group, a phenylene group, a naphthylene group, an anthylene group etc. are mentioned, for example. From a viewpoint of improving the photo-alignment property of the said liquid crystal aligning agent for photo-alignments, a phenylene group and a naphthylene group are preferable among these, and a phenylene group is more preferable.

As a bivalent organic group in the said C6-C20 aromatic ring couple | bonded with a single bond or a bivalent organic group, a C1-C30 bivalent hydrocarbon group etc. are mentioned, for example.

As said C1-C30 bivalent hydrocarbon group, these groups, such as a C1-C30 bivalent linear hydrocarbon group, a C3-C30 bivalent alicyclic hydrocarbon group, a C6-C30 divalent aromatic hydrocarbon group, are combined The group formed by this etc. are mentioned.

Examples of the group in which the plural aromatic rings having 6 to 20 carbon atoms are bonded to a single bond or a divalent organic group include, for example, a group in which a plurality of benzene rings are bonded to a single bond or a divalent organic group, and the like. Groups in which three benzene rings are bonded to a single bond or a divalent organic group are preferable, and groups in which two benzene rings are bonded to a single bond are more preferable.

Examples of the group containing the alicyclic group represented by Y include groups in which a C4-20 divalent alicyclic hydrocarbon group, a C6-20 alicyclic hydrocarbon group is bonded to a single bond or a divalent organic group, and the like. Can be mentioned.

As said C4-C20 alicyclic hydrocarbon group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cyclooctylene group, a norbornylene group, an adamantylene group, etc. are mentioned, for example. Among these, a cyclopentylene group and a cyclohexylene group are preferable, a cyclohexylene group is more preferable, and a trans-1, 4- cyclohexylene group is further more preferable.

As a group to which the said C4-C20 alicyclic hydrocarbon group couple | bonds with a single bond or a divalent organic group, for example, two or three of the above-mentioned C4-C20 alicyclic hydrocarbon groups are a single bond or a divalent organic group. The group couple | bonded with the group etc. are mentioned. Although the alicyclic hydrocarbon groups couple | bonded with the said 2 or 3 single bond etc. may be mutually same group, or different groups, it is preferable that they are the same group. Of these, groups in which two or three of the above-described aliphatic hydrocarbon groups having 4 to 20 carbon atoms are bonded in a single bond are preferable, and groups in which two or three cyclohexylene groups are bonded in a single bond are more preferable. , Trans, trans-4,4'-bicyclohexylene group is more preferred.

As Y, a phenylene group, a naphthylene group, a group in which two or three benzene rings are bonded in a single bond, a cyclohexylene group, a group in which two or three cyclohexylene groups are bonded in a single bond, A phenylene group, a biphenylene group, a trans-1, 4- cyclohexylene group, a trans, and a trans-4,4'-bicyclohexylene group are more preferable.

As said X <^1> and X <^2> , -O- and -NH- are preferable and -O- is more preferable.

As tetracarboxylic dianhydride represented by said formula (5), the compound etc. which are represented by following formula (5-1)-(5-7) are mentioned, for example.

Among these aromatic tetracarboxylic dianhydrides, pyromellitic dianhydrides, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydrides, 3,3', 4,4'-biphenylsulfontetracarboxylic acid 2 Anhydrides, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride represented by the formula (5) are preferable. And pyromellitic dianhydride and the compound represented by said formula (5-1)-(5-7) are more preferable.

As tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride is preferable, pyromellitic dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride, 3,3', 4,4 ' -Biphenyl sulfontetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid dianhydride, represented by the formula (5) Aromatic tetracarboxylic dianhydride is more preferable, and pyromellitic dianhydride and the compound represented by said formula (5-1)-(5-7) are more preferable.

As an use ratio of the diamine component (total of the diamine compound and other diamine compound represented by said Formula (4)) and tetracarboxylic dianhydride component used for the synthesis reaction of a polyamic acid (A1), the amino group 1 contained in a diamine component With respect to the equivalent, the acid anhydride group of the tetracarboxylic dianhydride component is preferably 0.2 equivalent to 2 equivalents, and more preferably 0.3 equivalent to 1.2 equivalents.

The content rate of the dark acid structural unit derived from the diamine component in a polyamic acid (A1) and the tetracarboxylic dianhydride component is 0.1 mol%-100 mol% with respect to all the structural units which polyamic acid (A1) has. It is preferable that it is 5 mol%-95 mol%, and it is still more preferable that it is 50 mol%-90 mol%.

The content rate of the structural unit (I) represented by the said tetracarboxylic dianhydride in polyamic acid (A1) and said Formula (2) derived from the said diamine compound is with respect to the whole structural unit which polyamic acid (A1) has. It is preferable that they are 50 mol%-100 mol%, It is more preferable that they are 60 mol%-100 mol%, It is still more preferable that they are 80 mol%-100 mol%.

It is preferable to perform the synthesis reaction of polyamic acid (A1) in an organic solvent. As reaction temperature, -20 degreeC-150 degreeC is preferable, and 0 degreeC-100 degreeC is more preferable. As reaction time, 0.5 hour-24 hours are preferable, and 2 hours-12 hours are more preferable.

The organic solvent is not particularly limited as long as it can dissolve the polyamic acid (A1) to be synthesized. Examples of the organic solvent include non-protic polar solvents, phenols and derivatives thereof, alcohols, ketones, esters, ethers, and halogenated hydrocarbons. And hydrocarbons.

As these specific examples, N-methyl- 2-pyrrolidone (NMP), N, N- dimethylacetamide, N, N- dimethylformamide, dimethyl sulfoxide, (gamma) -butyrolactone, tetramethylurea, hexamethyl phosphate Aprotic polar solvents such as fortriamide;

phenol derivatives such as m-cresol, xylenol and halogenated phenol;

Alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol and ethylene glycol monomethyl ether;

Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone;

Esters such as ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate, diethyl oxalate and diethyl malonate;

Diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, di Ethers such as ethylene 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 and tetrahydrofuran;

Halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene and o-dichlorobenzene;

Hydrocarbons, such as hexane, heptane, octane, benzene, toluene, xylene, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether, are mentioned, respectively.

Among these organic solvents, at least one organic solvent selected from the group (p) consisting of aprotic polar solvents, phenols and derivatives thereof, or at least one organic solvent selected from the group (p), alcohols, ketones, Preference is given to using mixtures with at least one organic solvent selected from the group (q) consisting of esters, ethers, halogenated hydrocarbons and hydrocarbons. In the latter case, it is preferable that it is 50 mass% or less with respect to the sum total of the organic solvent of group (p) and the organic solvent of group (q), and, as for the use ratio of the organic solvent of group (q), it is more preferable that it is 40 mass% or less. It is preferable and it is especially preferable that it is 30 mass% or less.

As the usage-amount (alpha) of an organic solvent, 0.1 mass%-50 mass% are preferable with respect to the total ((alpha) + (beta)) of the total amount ((beta)) of the tetracarboxylic dianhydride component and a diamine compound component, and the usage-amount ((alpha)) of an organic solvent, 5 mass%-30 mass% are more preferable.

The polyamic acid solution obtained after reaction may be used for preparation of the liquid crystal aligning agent for photo-alignment as it is, may be used for preparation of the liquid crystal aligning agent for photo-alignment after isolating the polyamic acid contained in a reaction solution, and isolated polyamic acid After refine | purifying, you may use for preparation of a liquid crystal aligning agent. As a method for isolating polyamic acid, for example, a method of drying the precipitate obtained by pouring the reaction solution in a large amount of poor solvents under reduced pressure, a method of distilling the reaction solution under reduced pressure with an evaporator, and the like can be given. As a purification method of a polyamic acid, the method of dissolving isolated polyamic acid again in an organic solvent, precipitating with a poor solvent, and performing the process of distilling off an organic solvent etc. with an evaporator under reduced pressure once or several times are mentioned. have.

In the synthesis of the polyamic acid, in addition to the tetracarboxylic dianhydride and the diamine compound, a terminal-modified polymer may be synthesized using a suitable molecular weight regulator. By using such a polymer having a terminal modification type, the coating property (printing property) of the liquid crystal aligning agent can be further improved without impairing the effect of the present invention.

As said molecular weight modifier, an acid monoanhydride, a monoamine compound, a monoisocyanate compound, etc. are mentioned, for example.

Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride, and the like. .

As a monoamine compound, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, etc. are mentioned, for example.

As a monoisocyanate compound, phenyl isocyanate, naphthyl isocyanate, etc. are mentioned.

It is preferable to set it as 20 mass parts or less with respect to a total of 100 mass parts of tetracarboxylic dianhydride and diamine to be used, and, as for the usage ratio of the said molecular weight modifier, it is more preferable to set it as 10 mass parts or less.

[Synthesis method of polyimide (A2)]

The polyimide (A2) may be a complete imide obtained by dehydrating and ring-closing the entire acidic structure of the polyamic acid (A1) as a precursor thereof. The partial imide may be sufficient. It is preferable that the imidation ratio of polyimide (A2) is 30% or more, It is more preferable that it is 50 to 99%, It is more preferable that it is 65 to 99%. The imidization rate is a percentage of the ratio of the number of imide ring structures to the sum of the number of amide structure and the number of imide ring structure of polyimide. Here, a part of the imide ring may be an isoimide ring.

Polyimide (A2) can be obtained by dehydrating and ring-closing the polyamic acid (A1) synthesize | combined as mentioned above and imidating.

The dehydration ring closure of the polyamic acid (A1) is preferably heated by a method of heating the polyamic acid (A1), or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution. It is done by the method. Of these, the latter method is preferable.

In the method of adding a dehydrating agent and a dehydrating ring-closure catalyst to the solution of the polyamic acid (A1), for example, acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the dark acid structure of polyamic acid (A1). As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably 0.01 to 10 mol based on 1 mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring-closure reaction include the organic solvents exemplified for use in the synthesis of the polyamic acid (A1). The reaction temperature of the dehydration ring-closure reaction is preferably 0 ° C to 180 ° C, more preferably 10 ° C to 150 ° C. The reaction time is preferably 1.0 hour to 120 hours, more preferably 2.0 to 30 hours.

The reaction solution containing the obtained polyimide (A2) may be provided as it is to the preparation of the liquid crystal aligning agent for photoalignment as it is, or may be provided to the preparation of the liquid crystal aligning agent for photoalignment after removing the dehydrating agent and the dehydration ring-closure catalyst from the reaction solution. After isolation | separation of polyimide (A2), you may provide for preparation of the liquid crystal aligning agent for photoalignment, or may provide for preparation of the liquid crystal aligning agent for photoalignment after refine | purifying the isolated polyimide (A2). These purification operations can be carried out according to a known method.

When the polyamic acid (A1) and polyimide (A2) obtained as mentioned above are made into the solution of 10 mass% of concentration, it is preferable to have a solution viscosity of 20 mPa * s-800 mPa * s, and it is 30 mPa * s-500 mPa. It is more preferable to have a solution viscosity of s. The solution viscosity (mPa * s) of the said [A] polymer is the density | concentration 10 prepared using the quantity solvent of these polymers (for example, (gamma) -butyrolactone, N-methyl- 2-pyrrolidone, etc.). It is the value measured at 25 degreeC using the E-type rotational viscometer about the mass% polymer solution.

<Other components>

Although the liquid crystal aligning agent for photo-alignments of this invention contains the [A] polymer as an essential component, you may contain other components as needed. As other components, other polymers other than the [A] polymer, the compound which has at least 1 epoxy group in a molecule | numerator (henceforth "epoxy compound"), a functional silane compound, etc. are mentioned, for example.

(Other polymers)

The other polymers can be used for improving solution properties and electrical properties. Such other polymers are polymers other than [A] polymers, such as the said polyamic acid (A1) and the said polyimide (A2), For example, the polyamic acid which does not have a structure represented by said formula (1) (hereinafter, " Other polyamic acid)), a polyimide formed by dehydrating and ringing the other polyamic acid (hereinafter also referred to as "other polyimide"), and a polyamic acid ester or polyester having no structure represented by the formula (1) , "Other polyesters"), polyamides, polysiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like. Among these, other polyamic acid, other polyimide, and other polyester are preferable, other polyamic acid and other polyimide are more preferable, and other polyamic acid is more preferable.

As tetracarboxylic dianhydride used for synthesize | combining the said other polyamic acid or other polyimide, the same thing as mentioned above as tetracarboxylic dianhydride used for synthesize | combining the polyamic acid (A1) used for this invention is mentioned. However, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, pyromellitic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride and 1,3,3a, 4,5,9b- Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione using at least one member selected from the group consisting of It is preferable.

As the diamine used for synthesizing the other polyamic acid or the other polyimide, at least one selected from the examples exemplified as other diamine compounds which may be used when synthesizing the polyamic acid (A1) used in the present invention may be used. Can be. Among them, 4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, cholestanyloxy-2,4-diaminobenzene, 3,5-diamino At least one selected from the group consisting of benzoic acid and 1,4-bis- (4-aminophenyl) -piperazine is preferred.

As a usage ratio of another polymer, it is preferable that it is 50 mass% or less with respect to a [A] polymer, It is more preferable that it is 40 mass% or less, It is further more preferable that it is 30 mass% or less.

(Epoxy compound)

Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, Neopentylglycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl Ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N- diglycidyl-benzylamine, N, N- diglycidyl-aminomethylcyclohexane, N, N-di Glycidyl cyclohexylamine etc. are mentioned as a preferable thing.

The compounding ratio of these epoxy compounds becomes like this. Preferably it is 40 mass parts or less, More preferably, it is 0.1-30 mass parts with respect to 100 mass parts of total polymers.

(Functional silane compound)

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2 -Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N- Trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3 , 6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazononanoate, Methyl 3,6-diazananoic acid, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltrie A methoxysilane, 3-glycidoxy propyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, etc. are mentioned.

The blending ratio of these functional silane compounds is preferably 2 parts by mass or less, and more preferably 0.02 to 0.2 parts by mass with respect to 100 parts by mass in total.

<Preparation of the liquid crystal aligning agent for photoalignment>

The liquid crystal aligning agent for photo-alignment of this invention contains [A] polymers, such as said polyamic acid (A1) and polyimide (A2), and the other components arbitrarily mix | blended arbitrarily as needed, Preferably melt-containing in an organic solvent. It is composed.

As an organic solvent used for the liquid crystal aligning agent for photoalignments of this invention, N-methyl- 2-pyrrolidone, (gamma) -butyrolactone, (gamma) -butyrolactam, N, N- dimethylformamide, N, for example , N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl Ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol 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 Yit, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. are mentioned. These may be used alone or in combination of two or more.

Although solid content concentration (the ratio which the total mass of components other than the solvent of a liquid crystal aligning agent occupies for the total mass of a liquid crystal aligning agent) in the liquid crystal aligning agent for photo-alignments of this invention is selected suitably in consideration of viscosity, volatility, etc., Preferably it is 1-10 mass% of range. That is, the liquid crystal aligning agent for photo-alignment of this invention is apply | coated to the surface of a board | substrate as mentioned later, Preferably, when the coating film which becomes a coating film which is a liquid crystal aligning film, or a liquid crystal aligning film is formed, when solid content concentration is less than 1 mass%, When the film thickness of this coating film becomes too small and a favorable liquid crystal aligning film cannot be obtained, On the other hand, when solid content concentration exceeds 10 mass%, the film thickness of a coating film becomes excessive and a favorable liquid crystal aligning film cannot be obtained, and light The viscosity of the liquid crystal aligning agent for orientation increases, and it becomes inferior to coating property.

The range of especially preferable solid content concentration changes with the method used when apply | coating the liquid crystal aligning agent for photoalignments to a board | substrate. For example, in the case of a spinner method, the range of 1.5 mass%-4.5 mass% of solid content concentration is especially preferable. When using the printing method, it is especially preferable to make solid content concentration into the range of 3-9 mass%, and to make solution viscosity into the range of 12 mPa * s-50 mPa * s. When using the inkjet method, it is especially preferable to make solid content concentration into the range of 1-5 mass%, and to make solution viscosity into the range of 3 mPa * s-15 mPa * s.

The temperature at the time of preparing the liquid crystal aligning agent for photoalignment of this invention becomes like this. Preferably it is 10 degreeC-50 degreeC, More preferably, it is 20 degreeC-30 degreeC.

<Liquid crystal aligning film>

The liquid crystal aligning film of this invention is formed of the said liquid crystal aligning agent for photoalignments. Therefore, in a formation process, the outstanding liquid crystal aligning ability can be provided by the radiation of a low irradiation amount. Moreover, since the heating process during and after irradiation of a radiation is unnecessary, production efficiency is good and manufacturing cost can also be reduced.

<Formation method of liquid crystal aligning film>

The liquid crystal aligning agent for photoalignments of this invention can be used widely as a material of the liquid crystal aligning film for photoalignments. Moreover, it can use suitably for forming the liquid crystal aligning film used for the liquid crystal display element which has a TN type or STN type liquid crystal cell, or the transverse electric field type liquid crystal display element which has liquid crystal cells, such as IPS type and FFS type. When the liquid crystal aligning agent for photo-alignment of this invention is especially applied to the liquid crystal display element which has a liquid crystal cell of an IPS type | mold or a FFS type, the effect of this invention is exhibited to the maximum and it is preferable.

The formation method of the liquid crystal aligning film of this invention,

(1) Process of forming a coating film on a board | substrate using the liquid crystal aligning agent for photoalignments of this invention (henceforth "a process (1)"),

(2) It includes the step (hereinafter also referred to as step (2)) of forming a liquid crystal alignment film by irradiating the coating film with light. Hereinafter, each process is explained in full detail.

[Step (1)]

Here, when the liquid crystal aligning agent for photo-alignment of this invention is applied to the liquid crystal display element which has a TN type or STN type liquid crystal cell, the pair of board | substrates with which the patterned transparent conductive film is formed is carried out, and the On each transparent conductive film formation surface, the liquid crystal aligning agent for photoalignments of this invention is apply | coated, and a coating film is formed. On the other hand, when the liquid crystal aligning agent for photo-alignment of this invention is applied to the liquid crystal display element which has a liquid crystal cell of an IPS type | mold or a FFS type | mold, the board | substrate which has an electrode in which the transparent conductive film or the metal film was patterned to comb-shaped on one side, and Using the opposing board | substrate with which the electrode is not formed as a pair, the liquid crystal aligning agent for photoalignment of this invention is apply | coated to the formation surface of a comb-tooth shaped electrode, and the single side | surface of an opposing board | substrate, respectively, and a coating film is formed.

In any case, as said board | substrate, For example, glass, such as float glass and a soda glass; Transparent substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone and polycarbonate can be used. As the transparent conductive film, an ITO film made of In ₂ O ₃ -SnO ₂ , an NESA (registered trademark) film made of SnO ₂ , and the like can be used. As the metal film, for example, a film made of a metal such as chromium can be used. For patterning of the transparent conductive film and the metal film, for example, after forming a patternless transparent conductive film, a method of forming a pattern by a photo etching method, a sputtering method, or the like, or a method using a mask having a desired pattern when forming a transparent conductive film Or the like.

In order to further improve the adhesion between the substrate, the conductive film and the electrode, and the coating film when the liquid crystal aligning agent for photo-alignment onto the substrate is applied, the functional silane compound, titanate, or the like is previously formed on the substrate and the electrode. May be applied.

Coating of the liquid crystal aligning agent for photo-alignment onto a board | substrate, Preferably, it can carry out by suitable coating methods, such as an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, Then, each coating surface is preheated ( Prebaking), and then baking (postbaking) to form a coating film. Prebaking conditions are 0.1 minutes-5 minutes, for example at 40 degreeC-120 degreeC, and postbaking conditions are preferably 120 degreeC-300 degreeC, More preferably, they are 150 degreeC-250 degreeC, Preferably they are 5 minutes. 200 minutes, More preferably, they are 10 minutes-100 minutes. The film thickness of the coating film after postbaking becomes like this. Preferably it is 0.001 micrometer-1 micrometer, More preferably, it is 0.005 micrometer-0.5 micrometer.

[Step (2)]

The liquid crystal aligning ability is provided by irradiating the polarized radiation to the coating film formed in this way. Here, as the radiation, for example, ultraviolet rays and visible rays containing light having a wavelength of 150 nm to 800 nm can be used, but ultraviolet rays containing light having a wavelength of 200 nm to 400 nm are preferable.

As the light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an Hg-Xe lamp and an excimer laser can be used. The ultraviolet ray of the above-mentioned preferable wavelength range can be obtained by a means for using the light source together with a filter, a diffraction grating, or the like.

When the liquid crystal aligning agent for photo-alignment of this invention is used normally, ultraviolet irradiation of 10,000 J / m <2> or more is needed, and even if it is 8,000 J / m <2>, favorable liquid crystal aligning ability can be provided and productivity improvement and manufacture of a liquid crystal display element are possible. Contribute to cost reduction

<Liquid crystal display element>

The liquid crystal display element of this invention is equipped with the liquid crystal aligning film formed using the said liquid crystal aligning agent for photoalignments. Since the liquid crystal aligning film can acquire liquid crystal aligning ability by the radiation dose less than conventional, the liquid crystal display element provided with the said liquid crystal aligning film can be manufactured more inexpensively than before. The liquid crystal display element of this invention can be manufactured as follows, for example.

A pair of board | substrates with which the liquid crystal aligning film was formed as mentioned above is prepared, and the liquid crystal cell of the structure by which the liquid crystal was clamped between this pair of board | substrates is manufactured. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.

The first method is a conventionally known method. As each liquid crystal aligning film opposes, two board | substrates are opposingly arranged through a gap (cell gap), and the peripheral part of two board | substrates is joined using a sealing agent, and it partitioned by the surface of a board | substrate and a sealing agent. After injecting and filling a liquid crystal in a cell gap, a liquid crystal cell can be manufactured by sealing an injection hole.

The second method is a method called an ODF (One Drop Fill) method. An ultraviolet-ray curable sealing compound is apply | coated to predetermined | prescribed place on one board | substrate among two board | substrates with which the liquid crystal aligning film was formed, for example, after dropping a liquid crystal on the liquid crystal aligning film surface, the other so that a liquid crystal aligning film may oppose. A liquid crystal cell can be manufactured by bonding one board | substrate, then irradiating an ultraviolet-ray to the whole surface of a board | substrate, and hardening a sealing compound.

In any case, it is preferable to remove the liquid crystal filling during liquid crystal filling by gradually cooling the liquid crystal cell to the temperature at which the liquid crystal using the liquid crystal isotropically taken and then gradually cooled to room temperature.

The liquid crystal display element of the present invention can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Here, the desired liquid crystal display element can be obtained by adjusting the angle which the polarization direction of the irradiated linearly polarized radiation and the angle of each board | substrate and a polarizing plate in two board | substrates with a liquid crystal aligning film form suitably.

As said sealing agent, the epoxy resin etc. which contain the aluminum oxide sphere as a spacer, a hardening | curing agent, etc. can be used, for example.

As said liquid crystal, a nematic liquid crystal, a smectic liquid crystal, etc. can be used, for example. It is preferable to have positive dielectric anisotropy which forms a nematic liquid crystal, For example, a biphenyl type liquid crystal, a phenyl cyclohexane type liquid crystal, ester type liquid crystal, a terphenyl type liquid crystal, a biphenyl cyclohexane type liquid crystal, a pyri Midine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, kuban-based liquid crystals and the like are used. Moreover, cholesteryl liquid crystals, such as cholesteryl chloride, cholesteryl nonaate, a cholesteryl carbonate, can be used for the said liquid crystal, for example;

Chiral agent sold as brand names "C-15" and "CB-15" (above, Merck);

Strong dielectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be further added and used.

As a polarizing plate used on the outer side of a liquid crystal cell, the polarizing plate which sandwiched the polarizing film called "H film | membrane" which absorbed iodine while extending | stretching polyvinyl alcohol between the cellulose acetate protective film, or the polarizing plate which consists of H film itself, etc. are mentioned. . The liquid crystal display element of this invention manufactured in this way is excellent in manufacturing performance, such as a display characteristic and an electrical characteristic.

[Example]

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

<Synthesis of Polyamic Acid (A1) and Polyimide (A2)>

Synthesis Example 1

4.66 g of pyromellitic dianhydride and 2.84 g of the diamine compound represented by following formula (4-1) are melt | dissolved in 42.5 g of N-methyl- 2-pyrrolidone, and it is made to react at room temperature for 4 hours, and solid content concentration 15 mass% And the solution containing polyamic acid (P-1) of viscosity 246 mPa * s was obtained.

[Synthesis Example 2]

6.40 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 3.60 g of diamine represented by the above formula (4-1) are dissolved in 56.7 g of N-methyl-2-pyrrolidone and 4 hours at 60 ° C. It reacted and obtained the solution containing the polyamic acid of viscosity 240mPa * s. 33.3 g of gamma -butyrolactone, 11.30 g of pyridine, and 8.75 g of acetic anhydride were added to the solution containing the obtained polyamic acid, and it was made to react at 110 degreeC for 4 hours. After completion of the reaction, the reaction solution was concentrated to 80 g, 100 g of γ-butyrolactone was added, and further concentrated to 80 g to contain a polyimide (P-2) having a solid content concentration of 12.1% by mass and an imidation ratio of 92%. Got.

[Synthesis Example 3]

5.12 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1.25 g of pyromellitic dianhydride, and 3.63 g of diamine represented by the above formula (4-1) are 56.7 g of N-methyl-2-pyrrolidone. It melt | dissolved in and reacted at 60 degreeC for 4 hours, and obtained the solution containing the polyamic acid of viscosity 250 mPa * s. To the obtained solution containing polyamic acid, 33.3 g of gamma -butyrolactone, 4.52 g of pyridine and 5.83 g of acetic anhydride were added and reacted at 110 ° C for 4 hours. After completion of the reaction, the reaction solution was concentrated to 80 g, 100 g of γ-butyrolactone was added, and again concentrated to 80 g, and a solution containing polyimide (P-3) having a solid content concentration of 12.0% by mass and an imidation ratio of 81%. Got.

[Synthesis Example 4]

12.6 g of the acid anhydride represented by the following formula (5-1) and 3.42 g of the diamine represented by the formula (4-1) are dissolved in 90.7 g of N-methyl-2-pyrrolidone, and reacted at room temperature for 4 hours. The solution containing the polyamic acid (P-4) of 15.0 mass% of solid content concentration and a viscosity of 978 mPa * s was obtained.

Synthesis Example 5

16.2 g of the acid anhydride represented by the following formula (5-3) and 3.78 g of the diamine represented by the formula (4-1) are dissolved in 180 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 4 hours, The solution containing 10.0 mass% of solid content concentration and the polyamic acid (P-5) of viscosity 508 mPa * s was obtained.

[Synthesis Example 6]

8.7 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 6.3 g of the diamine compound represented by the following formula (4-7) are dissolved in 85 g of N-methyl-2-pyrrolidone, and 4 is obtained at room temperature. It reacted for time, and obtained the solution containing 15 mass% of solid content concentration and the polyamic acid (P-6) of 305 mPa * s of viscosity.

[Comparative Synthesis Example 1]

6.50 g of pyromellitic dianhydride and 5.50 g of 4,4'-diaminodiphenylmethane are dissolved in 68.0 g of N-methyl-2-pyrrolidone, and reacted at room temperature for 4 hours to give a solid content concentration of 15.0 mass%, A solution containing polyamic acid (R-1) having a viscosity of 238 mPa · s was obtained.

[Comparative Synthesis Example 2]

13.1 g of poly (2-hydroxyethyl methacrylate) was dissolved in 50 mL of N-methyl-2-pyrrolidone, cooled to room temperature, and then 10 mL of pyridine was added. 17.0 g of cinnamoyl chloride was added to this, and it stirred for 8 hours. The reaction mixture was diluted with N-methyl-2-pyrrolidone and added to methanol, and the precipitate was washed with water sufficiently and dried to give a solution containing polymer (R-2).

<Preparation of the liquid crystal aligning agent for photoalignment>

Example 1

In a solution containing the polyamic acid (P-1) (amount equivalent to 100 parts by mass in terms of solid content of polyamic acid), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve ( BC) were added, and 20 mass parts of N, N, N ', N'- tetraglycidyl-4,4'- diamino diphenylmethane were further added as an epoxy compound, and it stirred, and a solvent composition NMP: BC = It was set as the solution of 60:40 (mass ratio) and 2.5 mass% of solid content concentration. The liquid crystal aligning agent (A-1) was prepared by filtering this solution using the filter of 1 micrometer of pore diameters.

EXAMPLES 2-6, COMPARATIVE EXAMPLES 1-2

Instead of the solution containing polyamic acid (P-1), the polyamic acid, the polyimide or the polymers (P-2) to (P-6) and (R-1) to (R-2) shown in Table 1 Liquid crystal aligning agents (A-2)-(A-6) and (B-1)-(B-2) were prepared like Example 1 except having used each containing solution.

<Manufacture of Liquid Crystal Display Element>

Each liquid crystal aligning agent prepared above was apply | coated using the spinner so that film thickness might be set to 0.1 micrometer on the transparent electrode of the glass substrate with a transparent electrode which consists of an ITO film, respectively, and it dried at 200 degreeC for 1 hour, and formed the coating film. The surface of this coating film was irradiated with ultraviolet rays of polarized light containing 254 nm bright rays at an irradiation dose of 8,000 J / m 2, 10,000 J / m 2, or 20,000 J / m 2 from the substrate normal direction using a Hg-Xe lamp. And the liquid crystal aligning film were formed. Next, with respect to a pair of board | substrates which performed the said light irradiation process, leaving a liquid crystal injection hole in the edge of the surface where the liquid crystal aligning film was formed, screen-printing apply | coating the aluminum oxide sphere containing epoxy resin adhesive of 5.5 micrometers in diameter, and at the time of light irradiation The substrates were overlapped and pressed so that the projection direction of the polarization axis onto the substrate surface became antiparallel, and the adhesive was thermosetted at 150 ° C. for 1 hour. Next, after filling a nematic liquid crystal (MLC-7028 by Merck Co., Ltd.) between a pair of board | substrates, the liquid crystal injection hole was sealed with the epoxy adhesive. In addition, in order to remove the flow orientation at the time of liquid crystal injection, after heating at 150 degreeC, it cooled gradually to room temperature. Next, the polarizing plate was bonded to the outer both surfaces of the board | substrate, and the liquid crystal display element was produced.

The following evaluation was performed about each said liquid crystal display element. The results are shown in Table 1.

<Evaluation>

[Liquid crystal alignment property]

In the liquid crystal display device, the presence or absence of an abnormal domain when the voltage is turned on or off (applied or released) is observed by a polarizing microscope, and the case where there is no abnormal domain is "good" and there is at least one abnormal domain. Was determined to be “bad”.

[Voltage maintenance rate]

A voltage of 5 V was applied to a liquid crystal display device produced with a polarized ultraviolet irradiation amount of 8,000 J / m 2 at 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the release of the application was measured. The measuring device used VHR-1 manufactured by Toyo Technica. Table 1 shows the measured value (%) of the voltage holding ratio. When voltage retention is 90% or more, it can evaluate as "good", and in other cases, it is "defect".

[Afterimage characteristic (burn-in characteristic)]

As a board | substrate, the glass substrate which has the metal system of two systems which consists of chromium patterned by the comb-tooth shape shown in FIG. A liquid crystal display element of a transverse electric field system was produced in the same manner as in the production of the liquid crystal display element except for use as a pair. This transverse electric field system liquid crystal display element was put in the environment of 25 degreeC, 1 atmosphere, and the combined voltage of AC voltage 3.5V and DC voltage 5V was applied to electrode A for 2 hours, without applying voltage to electrode B. Immediately thereafter, a voltage of 4 V AC was applied to both the electrode A and the electrode B. FIG. The time from the time when the voltage of alternating current 4V was applied to both electrodes was measured until the difference between the light transmittances of the electrodes A and B could not be visually confirmed. The afterimage characteristic when this time was less than 100 second was evaluated as "good", the afterimage characteristic when 100 second or more and less than 150 second was "possible", and the afterimage characteristic when exceeding 150 second as "defect". .

As shown in Table 1, the liquid crystal aligning agent containing the polymer which has a specific structure represented by said Formula (1) in a principal chain has a high sensitivity with respect to radiation, and the liquid crystal aligning film obtained also by the low irradiation amount of 8,000 J / m <2>. The liquid crystal aligning property of the liquid crystal display element to be equipped became favorable. In addition, the voltage holding ratio was also good. In comparison, in Comparative Example 1, an abnormal domain was also observed even at a high irradiation amount of 20,000 J / m 2, resulting in poor liquid crystal orientation. As mentioned above, it became clear that the liquid crystal aligning agent for photo-alignments of this invention is excellent in radiation sensitivity, and can form the liquid crystal aligning film which has the outstanding liquid-crystal orientation by the irradiation of a low irradiation amount. Moreover, it turned out that the liquid crystal display element provided with the liquid crystal aligning film of this invention has the outstanding electrical characteristic and afterimage characteristic.

Since the liquid crystal aligning agent for photo-alignments of this invention can form the liquid crystal aligning film which has high radiation sensitivity and excellent liquid crystal aligning property by the irradiation of a low irradiation amount, the production efficiency is good and can reduce production cost. Moreover, the liquid crystal display element provided with the liquid crystal aligning film formed using the liquid crystal aligning agent of this invention is excellent in manufacturing performance, such as an electrical characteristic and an afterimage characteristic. Therefore, the liquid crystal aligning agent for photoalignments of this invention, a liquid crystal aligning film, the formation method of this liquid crystal aligning film, and a liquid crystal display element are used suitably for liquid crystal display elements, such as an IPS type and an FFS type.

101: electrode A
102: electrode B

Claims (8)

[A] Liquid crystal aligning agent for photoalignment containing polymer which has structural unit (I) containing structure represented by following formula (1):

(In formula (1), R <^1> is a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group; Ar <^1> is a group containing an aromatic ring; * is a hydrogen atom or another group Indicates the site of binding). The method of claim 1,
[A] Liquid crystal aligning agent for photoalignment whose polymer is polyamic acid or polyimide. The method of claim 2,
Liquid crystal aligning agent for photoalignments in which the said structural unit (I) is represented by following formula (2) or Formula (3):

(In formula (2) and (3), R <^1> is a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group; Ar <^1> is a group containing an aromatic ring; R <^2> and R ³ are each independently a tetravalent organic group). The method of claim 2,
The polyamic acid obtained by reaction of the diamine component containing the diamine compound which [A] polymer shows by [a] following formula (4), and [b] tetracarboxylic dianhydride component, and this polyamic acid dehydration ring closure Liquid crystal aligning agent for photoalignments which is at least 1 sort (s) of polymer chosen from the group which consists of polyimide which consists of:

(In formula (4), R <^1> is a hydrogen atom, a C1-C10 alkyl group, or a C3-C10 cycloalkyl group; Ar <^1> is group containing an aromatic ring.). 5. The method of claim 4,
[b] Liquid crystal aligning agent for photoalignment in which tetracarboxylic dianhydride component contains at least tetracarboxylic dianhydride represented by following formula (5):

(In Formula (5), Y is group containing an aromatic ring or alicyclic; X <^1> and X <^2> are respectively independently a single bond, -O-, -S-, or -NH-). (1) Process of forming coating film on board | substrate using liquid crystal aligning agent for photoalignments in any one of Claims 1-5,
(2) Process of forming a liquid crystal aligning film by irradiating light to the said coating film
Formation method of a liquid crystal aligning film containing. The liquid crystal aligning film formed using the liquid crystal aligning agent for photoalignments in any one of Claims 1-5. The liquid crystal display element provided with the liquid crystal aligning film of Claim 7.

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