KR20220109304A - Liquid crystal aligning agent, liquid crystal alignment film and manufacturing method thereof, and liquid crystal device - Google Patents

Abstract

The purpose of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal element having good liquid crystal orientation and good voltage retention properties even when heating is performed at a low temperature during film formation. The liquid crystal aligning agent comprises: a polymer (P) having a partial structure (A) in which an acid-leaving group is bonded to at least one of a nitrogen atom and an oxygen atom; a compound (C) which is at least one selected from a group consisting of polyfunctional aliphatic carboxylic acids, salts of the polyfunctional aliphatic carboxylic acids, and thermal acid generators that generate the polyfunctional aliphatic carboxylic acids (except for polymers); and a solvent.

Description

A liquid crystal aligning agent, a liquid crystal aligning film, its manufacturing method, and a liquid crystal element TECHNICAL FIELD

This invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, its manufacturing method, and a liquid crystal element.

BACKGROUND ART Liquid crystal elements are widely used in televisions, mobile devices, various monitors, and the like. With such versatility, further quality improvement is calculated|required by a liquid crystal element, and improvement of the liquid crystal aligning film which is one of the constituent materials of a liquid crystal element is progressing with improvement of a drive system and element structure.

As a polymer used for a liquid crystal aligning film, for the purpose of improving solubility in an organic solvent or improving applicability, etc., a substituent (hereinafter, also referred to as "thermal leaving group") which is released by heat when forming a liquid crystal aligning film is introduced. thing is being considered (for example, refer patent document 1). In Patent Document 1, a polyimide obtained by using a diamine having a group "-ND-" (provided that D is a thermal leaving group substituted with a hydrogen atom by desorption at 150 to 230°C, preferably 180 to 230°C). It is made to contain in a liquid crystal aligning agent, and forming a liquid crystal aligning film is indicated.

International Publication No. 2019/082975

When a liquid crystal aligning film is formed using the liquid crystal aligning agent containing the polymer which has a thermal leaving property like patent document 1, in order to detach|desorb a heat leaving group, heating at a comparatively high temperature (for example, heating 200 degreeC or more) this becomes necessary

However, when heating at high temperature is required when forming a liquid crystal aligning film, problems, such as the material of a board|substrate being restrict|limited, arises, and applying a film base material as a board|substrate of a liquid crystal element may be restrict|limited. Moreover, a color liquid crystal display element WHEREIN: The dye used as the coloring agent for color filters is comparatively weak to a heat|fever, Therefore, there is concern that problems, such as fading, arise, or use of dye is restrict|limited.

On the other hand, the technique of patent document 1 WHEREIN: When formation of a liquid crystal aligning film is performed at comparatively low temperature, it is thought that a thermally detachable group remains in a liquid crystal aligning film without detaching|desorbing from a polymer. In that case, we are concerned that the orientation of a liquid crystal is disturbed in the interface of a liquid crystal aligning film, or a liquid crystal aligning film becomes sparse, and voltage preservation|save characteristic is reduced.

The present invention has been made in view of the above circumstances, and its main object is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal element having good liquid crystal orientation and voltage retention characteristics even when heating at the time of film formation is performed at low temperature.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, this invention employ|adopted the following means.

<1> A polymer (P) having a partial structure (A) in which an acid leaving group is bonded to at least one of a nitrogen atom and an oxygen atom, a polyfunctional aliphatic carboxylic acid, a salt of a polyfunctional aliphatic carboxylic acid, and a polyfunctional aliphatic carboxylic acid The liquid crystal aligning agent containing the compound (C) which is at least 1 type (however, except when it is a polymer) selected from the group which consists of a thermal acid generator which generate|occur|produces, and a solvent.

<2> 　 A liquid crystal aligning film formed using the liquid crystal aligning agent of <1>.

<3> 　 A liquid crystal element provided with the liquid crystal aligning film of said <2>.

<4> 　 The liquid crystal aligning agent of said <1> is apply|coated on a board|substrate, and the manufacturing method of the liquid crystal aligning film which heats at the temperature of 180 degrees C or less.

According to the liquid crystal aligning agent of this invention, even when heating at the time of film formation is performed at low temperature, the liquid crystal element with favorable liquid-crystal orientation and a voltage preservation characteristic can be obtained.

(Form for implementing the invention)

Hereinafter, matters related to aspects of the present disclosure will be described in detail. In addition, in this specification, a "hydrocarbon group" is a meaning including a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. A "chain hydrocarbon group" means a straight-chain hydrocarbon group and a branched hydrocarbon group composed of only a chain structure without including a cyclic structure. However, saturated or unsaturated may be sufficient. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only the structure of an alicyclic hydrocarbon as a ring structure and not containing an aromatic ring structure. However, it is not necessary to be constituted only by the structure of an alicyclic hydrocarbon, and those having a chain structure in a part thereof are also included. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be constituted by only the aromatic ring structure, and a chain structure or the structure of an alicyclic hydrocarbon may be included in a part thereof.

The "aliphatic hydrocarbon group" is meant to include a chain hydrocarbon group and an alicyclic hydrocarbon group. The "aliphatic compound" is meant to include a chain compound and an alicyclic compound. The "chain compound" means a linear compound and a branched compound composed of only a chain structure without a cyclic structure. However, saturated or unsaturated may be sufficient. An "alicyclic compound" means a compound containing only an aliphatic ring structure as a ring structure and not containing an aromatic ring structure. However, it does not need to be comprised only with the structure of an aliphatic ring, and it includes the thing which has a chain structure in a part of it. The "main chain" of a polymer means the part of the longest "stem" among the atomic chains of a polymer. The "side chain" of a polymer means the part which branched from the "stem" of a polymer. An "organic group" refers to an atomic group formed by removing arbitrary hydrogen atoms from a carbon-containing compound (that is, an organic compound).

《Liquid crystal aligning agent》

The liquid crystal aligning agent (henceforth "this liquid crystal aligning agent") of this indication contains the following polymer (P) and a compound (C). This liquid crystal aligning agent is a polymer composition in which these polymers (P) and a compound (C) preferably melt|dissolve or disperse|distribute to a solvent.

Polymer (P): A polymer having a partial structure (A) in which an acid leaving group is bonded to at least any of a nitrogen atom and an oxygen atom.

Compound (C): at least one compound selected from the group consisting of polyfunctional aliphatic carboxylic acids, salts of polyfunctional aliphatic carboxylic acids, and thermal acid generators that generate polyfunctional aliphatic carboxylic acids (however, except for polymers) box).

<Polymer (P)>

The partial structure (A) which the polymer (P) has is the structure which the acid leaving group couple|bonded with the nitrogen atom, the structure which the acid leaving group couple|bonded with the oxygen atom, or both. Here, in this specification, an "acid leaving group" is a group which substitutes the hydrogen atom which functional groups, such as an amino group and a hydroxyl group, have, and refers to the group which leaves|leaves by the action|action of an acid. Partial structure (A) is specifically represented by following formula (5) and formula (6).

*-NR ^a -* … (5)

*-OR ^a … (6)

(In formulas (5) and (6), R ^a is an acid leaving group. "*" represents a bond.)

The two bonds in the formula (5) may be mutually independently couple|bonded with the hydrocarbon group, and may couple|bond with the carbonyl group. In addition, one of the two bonds in the formula (5) may be bonded to a hydrogen atom. That is, the nitrogen atom in the partial structure represented by said formula (1) may be the nitrogen atom which a primary amino group or a secondary amino group has, and the nitrogen atom which an amide group, a urea group, a urethane group, etc. have may be sufficient as it.

It is preferable that the bond in said formula (6) is couple|bonded with the hydrocarbon group. That is, as for the partial structure represented by said Formula (2), it is preferable that it is a partial structure which produces|generates an alcoholic hydroxyl group or phenolic hydroxyl group when an acid leaving group detach|desorbs, It is more preferable that it is a partial structure which produces|generates a phenolic hydroxyl group.

It is preferable that the polymer (P) has the partial structure represented by the said Formula (5) at the point which can obtain the liquid crystal element which is more excellent in a voltage preservation characteristic by coexistence with a compound (C). When a polymer (P) has the partial structure represented by said Formula (5), a basic group (-NH-) arises because an acid leaving group detach|desorbs by heating at the time of film formation. In addition, when the polymer (P) in the film has a basic group, ionic cross-linking (physical cross-linking) is formed by acid-base interaction due to coexistence with the compound (C), the film becomes dense, and the voltage preservation characteristic is improved accordingly. it is presumed that

The polymer (P) may have a partial structure (A) in a principal chain, and may have it in a side chain. When the polymer (P) has a partial structure represented by the formula (5), the polymer (P) has a partial structure represented by the formula (5) in the main chain (that is, two bonds in the formula (5)) It is preferable that each hand is bonded to the atoms constituting the main chain). In this case, it is suitable from the point which can improve the solubility of a polymer and the phase-separation property at the time of setting it as a polymer blend by introduce|transducing a bulky group into the main chain of a polymer.

The partial structure (A) which the polymer (P) has is a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), a partial structure represented by the following formula (3), and a It is preferable that it is at least 1 sort(s) chosen from the group which consists of partial structures which appear.

(In Formulas (1) to (4), R ¹ to R ³ are each independently a monovalent hydrocarbon group. Y ¹ is a carbon atom or a silicon atom. When Y ¹ is a carbon atom, R ⁴ and R ⁵ is each independently a monovalent hydrocarbon group, or R ⁴ and R ⁵ are combined with each other to represent a ring structure constituted together with the carbon atom to which R ⁴ and R ⁵ are bonded. When Y ¹ is a silicon atom , R ⁴ and R ⁵ each independently represent a monovalent hydrocarbon group R ⁶ and R ⁷ satisfy the following (i) or (ii): "*" represents a bond.

(i) R ⁶ is a hydrogen atom or a monovalent hydrocarbon group. R ⁷ is a monovalent hydrocarbon group or a group including -O- between the carbon-carbon bonds of the monovalent hydrocarbon group.

(ii) R ⁶ and R ⁷ are taken together to represent a ring structure constituted together with the carbon atom to which R ⁶ is bonded and the oxygen atom to which R ⁷ is bonded.)

In the formulas (1) and (2), as the monovalent hydrocarbon group of R ¹ and R ² , a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a carbon number 6-20 monovalent aromatic hydrocarbon groups are mentioned.

Specific examples of these groups include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, including a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, alkyl groups such as n-pentyl group, sec-pentyl group, isopentyl group, tert-pentyl group and n-hexyl group; Alkenyl groups, such as a vinyl group, 1-propenyl group, 2-propenyl group, and isopropenyl group; Alkynyl groups, such as an ethynyl group, 1-propynyl group, and 2-propynyl group, are mentioned.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic saturated alicyclic hydrocarbon groups such as cyclobutyl group, cyclopentyl group, cyclohexylene group, cyclopropyl group and cyclohexyl group; polycyclic alicyclic saturated hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl and tetracyclododecyl; monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; Polycyclic alicyclic saturated hydrocarbon groups, such as a norbornenyl group and a tricyclodecenyl group, etc. are mentioned. Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group and anthryl group; Aralkyl groups, such as a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthryl methyl group, etc. are mentioned.

As the monovalent hydrocarbon group of R ¹ and R ² , the monovalent hydrocarbon group having 1 to 8 carbon atoms has high desorption properties and the residual amount in the film of the compound derived from the desorbed group can be reduced as much as possible. group is preferable, and an alkyl group having 1 to 6 carbon atoms is more preferable. Especially, it is preferable that -COOR ¹ in said formula (1) and -COOR ² in said formula (2) are tert-butoxycarbonyl group (Boc group).

In the formula (3), specific examples in the case where R ³ to R ⁵ are monovalent hydrocarbon groups include the groups exemplified as monovalent hydrocarbon groups of R ¹ and R ² . When R ³ to R ⁵ is a monovalent hydrocarbon group, R ³ to R ⁵ are preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms, more preferably an alkyl group or phenyl group having 1 to 6 carbon atoms.

When R ⁴ and R ⁵ are combined with each other to represent a ring structure constituted together with the carbon atom to which R ⁴ and R ⁵ are bonded, examples of the ring structure include an alicyclic structure having 3 to 20 carbon atoms. Specific examples thereof include monocyclic alicyclic structures such as a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure; Polycyclic alicyclic structures, such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure, etc. are mentioned.

In the formula (4), when R ⁶ and R ⁷ satisfy (i) above, R ⁶ is a hydrogen atom or a monovalent hydrocarbon group, and R ⁷ is a monovalent hydrocarbon group or carbon of a monovalent hydrocarbon group— It is a group containing -O- between carbon bonds. When R ⁶ is a monovalent hydrocarbon group and R ⁷ is a monovalent hydrocarbon group, specific examples of the monovalent hydrocarbon group include the groups exemplified as the monovalent hydrocarbon group of R ¹ and R ² . As a specific example in the case where R ⁷ is a group containing -O- between the carbon-carbon bonds of the monovalent hydrocarbon group, -O- is placed at any position in the group exemplified as the monovalent hydrocarbon group of R ¹ and R ² . group containing. From a viewpoint of making the volatility of leaving group favorable, 1-12 are preferable and, as for carbon number of R< ⁶ > and carbon number of R< ⁷ > in case R< ⁶ > is a monovalent|monohydric hydrocarbon group, 1-8 are more preferable.

When R ⁶ and R ⁷ satisfy (ii) above, R ⁶ and R ⁷ are combined with each other to form a ring structure formed together with the carbon atom to which R ⁶ is bonded and the oxygen atom to which R ⁷ is bonded (hereinafter referred to as “ring structure T"). Examples of the ring structure T in this case include an oxirane ring, an oxetane ring, a tetrahydrofuran ring, a 1,3-dioxolane ring, a tetrahydropyran ring, a 1,4-dioxane ring, and an oxepane ring. A 4-7 membered ring is preferable and, as for the ring structure T, a 5-membered ring or a 6-membered ring is more preferable.

As a specific example of a partial structure (A), as a partial structure represented by said formula (1), the partial structure etc. which are represented by following formula (1-1); As a partial structure represented by said Formula (2), the partial structure etc. which are represented by following formula (2-1); As a partial structure represented by said Formula (3), the partial structure etc. which are represented by each of following formula (3-1) - Formula (3-7); As a partial structure represented by said Formula (4), the partial structure etc. represented by each of following formula (4-1) - Formula (4-5) are mentioned, respectively.

(In the formula, Ph represents a phenyl group. "*" represents a bond.)

The partial structure (A) is a partial structure represented by the above formula (1), in particular, in terms of good desorption property by acid and the ability to reduce the residual amount in the film of the compound derived from the group that has been released. , the partial structure represented by the formula (2) and the partial structure represented by the formula (4) are preferable, and when the film is formed by low-temperature firing (preferably heating at 180° C. or less), Since the improvement effect is high, the partial structure represented by said Formula (1) is more preferable.

The main skeleton of the polymer (P) is not particularly limited, and for example, polyamic acid, polyamic acid ester, polyimide, polyamide, polyurea, polyamine, a monomer having a polymerizable carbon-carbon unsaturated bond (hereinafter referred to as “unsaturated and a polymer (hereinafter, also referred to as “polymer (Pm)”) having a structural unit derived from a “bond-containing monomer”). From the viewpoint of obtaining a liquid crystal device having excellent reliability, the polymer (P) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyurea, and polymer (Pm).

Since an organic film having high affinity with liquid crystal and high mechanical strength can be formed, the polymer (P) is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide (hereinafter referred to as polyamic acid). , also referred to as "polymer (PI)"). The polymer (PI) is not particularly limited as long as it has a partial structure (A). As a polymer (PI), the polymer which has at least 1 sort(s) selected from the group which consists of a partial structure represented by following formula (7), and a partial structure represented by following formula (8) is mentioned.

(In formulas (7) and (8), X ¹ is a tetravalent organic group. X ² is a divalent organic group. R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or It is a monovalent organic group having 1 to 8 carbon atoms, with the proviso that at least any of X ¹ , X ² , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ has a partial structure (A).

In the formulas (7) and (8), X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative. In addition, in this specification, "tetracarboxylic acid derivative" is meant including tetracarboxylic dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dihalide. In the synthesis of the polymer (PI), by using tetracarboxylic dianhydride (hereinafter also referred to as “specific acid anhydride A”) having a partial structure (A) as a tetracarboxylic acid derivative, X ¹ has a partial structure (A ) can be obtained.

As the tetracarboxylic acid derivative constituting X ¹ , a known compound can be used as a tetracarboxylic acid derivative usable in the production of polyamic acid, polyamic acid ester, and polyimide. From the viewpoint of solubility of the polymer (P) and transparency of the liquid crystal aligning film, X ¹ is preferably a tetravalent aliphatic hydrocarbon group, for example, a tetravalent group represented by each of the following formulas (9) to (14). have.

(In formulas (9) to (14), "*" represents a bond.)

It is preferable that X< ¹ > is a tetravalent alicyclic hydrocarbon group among the above. When obtaining a liquid crystal aligning film by the photo-alignment method, it is preferable that X< ¹ > is especially a tetravalent group which has a cyclobutane ring structure, Specifically, It is a tetravalent group represented by said Formula (9) or Formula (10) It is preferable, and it is more preferable that it is a tetravalent group represented by said Formula (10).

In said Formula (7) and Formula (8), X< ² > is a divalent organic group derived from a diamine compound. In the synthesis of the polymer (PI), since it is easy to introduce the partial structure (A) into the polymer, X ² is a structure derived from a diamine having the partial structure (A) (hereinafter also referred to as “specific diamine”). It is preferable that it is a unit.

When R ⁸ and R ⁹ are a monovalent organic group having 1 to 8 carbon atoms, R ⁸ and R ⁹ are preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms. When R ¹⁰ and R ¹¹ are a monovalent organic group having 1 to 8 carbon atoms, R ¹⁰ and R ¹¹ are preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms or an acid leaving group, and an alkyl group having 1 to 6 carbon atoms or tert -It is more preferable that it is a butoxycarbonyl group (Boc).

<Polyamic acid>

The synthesis method of a polymer (PI) is not specifically limited, It can obtain by combining the conventional method of organic chemistry suitably. When the polymer (PI) is polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid (P)") is, for example, (I) tetracarboxylic dianhydride containing specific acid anhydride A, and diamine The method of making a compound react, the method of making (II) tetracarboxylic dianhydride and the diamine compound containing a specific diamine react, and the method of combining said (I) and (II) are mentioned. Among these, it is preferable to follow the method of (II) from a point with a high degree of freedom in the selection of a monomer, and the point with which it is easy to introduce|transduce a specific structure (A) into a polymer.

(Tetracarboxylic acid dianhydride)

As tetracarboxylic dianhydride used for the synthesis|combination of polyamic acid (P), aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. are mentioned, for example.

The specific acid anhydride A is not particularly limited as long as it has a partial structure (A), and examples thereof include compounds represented by each of the following formulas (15-1) and (15-2).

(In the formula, "Boc" represents a tert-butoxycarbonyl group.)

Synthesis of polyamic acid (P) WHEREIN: When using specific acid anhydride A, the usage-amount of specific acid anhydride A is 1 to with respect to the total amount of tetracarboxylic dianhydride used for synthesis|combination of polyamic acid (P). 20 mol% is preferable, and 1-10 mol% is more preferable.

At the time of synthesizing a polyamic acid (P), tetracarboxylic dianhydride (hereinafter also referred to as "other acid anhydrides") which does not have a partial structure (A) can be used. As a specific example of another acid anhydride, As an aliphatic tetracarboxylic dianhydride, For example, 1,2,3,4- butanetetracarboxylic dianhydride, ethylenediamine tetraacetic acid dianhydride, etc.;

As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c ] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] Furan-1,3-dione, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tri Carboxy-2-carboxymethylnorbornane-2:3,5:6-2 anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2 anhydride , cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, etc.;

As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, p-phenylenebis(trimellitic acid monoester anhydride), ethylene glycol Bis(anhydrotrimellitate), 1,3-propylene glycol bis(anhydrotrimellitate), 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-biphthalic acid 2 anhydride and the like; In addition to what is mentioned respectively, the tetracarboxylic dianhydride of Unexamined-Japanese-Patent No. 2010-97188 is mentioned.

The other acid dianhydride is from the group which consists of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride from the point which can make the solubility of polyamic acid (P) high, and the point which can obtain a liquid crystal aligning film with high transparency It is preferable to contain at least 1 sort(s) selected (henceforth "specific acid anhydride B"), and it is more preferable to contain alicyclic tetracarboxylic dianhydride. When using the specific acid anhydride B when synthesizing the polyamic acid (P), the ratio of the specific acid anhydride B is preferably 30 mol% or more, and 50 mol% or more with respect to the total amount of tetracarboxylic dianhydride used for the synthesis. % or more is more preferable, and 70 mol% or more is still more preferable. At the time of the synthesis|combination of polyamic acid (P), as tetracarboxylic dianhydride, 1 type can be used individually or in combination of 2 or more types.

(diamine compound)

Specific diamine should just have a partial structure (A), and is not specifically limited. Although the specific diamine may have a partial structure (A) in any of a principal chain and a side chain, it is preferable to have a partial structure (A) in a principal chain from the point which can make the effect of the solubility improvement of a polymer high. As a preferable specific example of specific diamine, the compound represented by following formula (16) is mentioned.

(In formula (16), A ¹ and A ² are each independently a divalent aromatic group. Y ¹ and Y ² are each independently a single bond or a divalent organic group. Z ¹ is -NR ^b -, -CO-NR ^b -, -NR ^b -CO-NR ^c - or -NR ^b -COO- Z ² is a single bond, -NR ^d -, -CO-NR ^d -, -NR ^d - CO-NR ^e - or -NR ^d -COO-. R ^b is an acid dissociable group. R ^c , R ^d and R ^e are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 6 carbon atoms, or an acid. It is a dissociable group. B ¹ is a divalent organic group. n is an integer of 0 to 2. When n is 2, a plurality of B ¹ are the same or different, and a plurality of Z ² are the same or different.)

In the formula (16), examples of A ¹ and A ² include groups in which two hydrogen atoms have been removed from the ring moiety of a substituted or unsubstituted aromatic ring. As said aromatic ring, Aromatic hydrocarbon rings, such as a benzene ring, a naphthalene ring, and an anthracene ring; Aromatic heterocycles, such as a pyridine ring, a pyrimidine ring, a pyrazine ring, and a pyridazine ring, are mentioned. Among these, ^a benzene ring, ^a pyridine ring, a pyrimidine ring, or a pyrazine ring is preferable and, as for the aromatic ring which A1 and A2 have, a benzene ring or a pyridine ring is more preferable.

When Y ¹ , Y ² is a divalent organic group, the divalent organic group is a divalent chain hydrocarbon group having 1 to 5 carbon atoms or an arbitrary methylene group having a divalent chain hydrocarbon group having -O- or the like substituted with -O- or the like. A divalent group of -5 is mentioned.

Examples of the divalent organic group of B ¹ include a divalent chain hydrocarbon group having 1 to 12 carbon atoms, a divalent group having 2 to 12 carbon atoms in which an arbitrary methylene group of the divalent chain hydrocarbon group is substituted with -O- or the like, and a divalent group having 4 to carbon atoms. and a 12 divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and a heterocyclic divalent group having 4 to 20 carbon atoms.

As a specific example of specific diamine, the compound etc. which are represented by each of following formula (16-1) - Formula (16-14) are mentioned. In addition, as specific diamine, 1 type can be used individually or in combination of 2 or more type.

(In formulas (16-6) and (16-12), r is an integer of 1 to 12.)

At the time of the synthesis|combination of a polyamic acid (P), although only a specific diamine may be used as a diamine compound, you may use the diamine compound (henceforth "other diamine") different from a specific diamine with a specific diamine.

It will not specifically limit if it is a diamine compound which does not have a partial structure (A) as another diamine, For example, aliphatic diamine, alicyclic diamine, aromatic diamine, diaminoorganosiloxane, etc. are mentioned. Specific examples of the aliphatic diamine include metaxylylenediamine, ethylenediamine, 1,3-propanediamine, tetramethylenediamine, and hexamethylenediamine;

Examples of the alicyclic diamine include p-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine) and the like;

As the aromatic diamine, for example, dodecaneoxydiaminobenzene, hexadecaneoxydiaminobenzene, octadecaneoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene, diaminobenzoic acid cholestanyl, diamino Cholesteryl benzoate, Lanostanil diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 1,1-bis(4- ((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 2,5-diamino-N,N-diallylaniline, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO-, or *-OCO- (where "*" is a bond with the diaminophenyl group side) R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms. R ^III is an alkyl group or an alkoxy group having 1 to 20 carbon atoms. , a fluoroalkyl group, or a fluoroalkoxy group. a is 0 or 1. b is an integer from 0 to 3. c is an integer from 0 to 2. d is 0 or 1. provided that 1≤a+b+c≤ is 3.)

Branched diamines such as compounds represented by:

Paraphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-ethylenedianiline, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylamine, 4,4 '-diaminodiphenyl sulfide, 4-aminophenyl-4'-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,2-bis(4-aminophenoxy) Ethane, 1,5-bis(4-aminophenoxy)pentane, N,N'-di(4-aminophenyl)-N,N'-dimethylethylenediamine, bis[2-(4-aminophenyl)ethyl] Hexane diacid, bis(4-aminophenyl)amine, N,N-bis(4-aminophenyl)methylamine, 1,4-bis(4-aminophenyl)-piperazine, N,N'-bis(4 -Aminophenyl)-benzidine, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2 ,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-(phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4-( 4-Aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 4,4′-[4,4′-propane-1,3-diylbis(piperidin-1,4-diyl) )] non-branched diamines such as dianiline;

As the diaminoorganosiloxane, for example, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like; In addition to those mentioned respectively, the diamine compound of Unexamined-Japanese-Patent No. 2010-97188 can be used. In addition, at the time of the synthesis|combination of polyamic acid (P) WHEREIN: As another diamine, 1 type can be used individually or in combination of 2 or more type.

It is preferable that the use ratio of specific diamine shall be 2 mol% or more with respect to the total amount of the diamine compound used for the synthesis|combination of polyamic acid (P) from a viewpoint of fully obtaining the improvement effect of liquid-crystal orientation and voltage retention characteristic, 5 It is more preferable to set it as mol% or more, It is further more preferable to set it as 10 mol% or more, and it is still more preferable to set it as 20 mol% or more.

(Synthesis of polyamic acid)

Polyamic acid (P) can be obtained by making the above tetracarboxylic dianhydride and a diamine compound react with a molecular weight modifier as needed. As a molecular weight modifier, an acid monohydride, a monoamine compound, a monoisocyanate compound, etc. are mentioned, for example. The ratio of tetracarboxylic dianhydride and diamine compound used in the synthesis reaction of polyamic acid (P) is 0.2 to 2 molar equivalents of the acid anhydride groups of tetracarboxylic dianhydride with respect to 1 molar equivalent of the amino group of the diamine compound. ratio is preferred.

The synthesis reaction of the polyamic acid (P) is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20°C to 150°C, and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used for the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphor. At least one selected from the group consisting of triamide, m-cresol, xylenol and halogenated phenol is used as the solvent, or at least one of these and another organic solvent (eg, butylcellosolve, di ethylene glycol diethyl ether, etc.). It is preferable that the usage-amount of an organic solvent sets it as the quantity used as 0.1-50 mass % with respect to the total amount of tetracarboxylic dianhydride and a diamine compound with respect to the total amount of a reaction solution. The reaction solution formed by dissolving a polyamic acid (P) may be used for preparation of a liquid crystal aligning agent as it is, and after isolating the polyamic acid (P) contained in a reaction solution, you may provide for preparation of a liquid crystal aligning agent.

<Polyamic acid ester>

When the polymer (PI) is a polyamic acid ester, the polyamic acid ester is, for example, [I] with the polyamic acid (P) obtained above and an esterifying agent (such as methanol or ethanol, N,N-dimethylformamide) Diethyl acetal, etc.), [II] A tetracarboxylic acid diester and a diamine compound containing a specific diamine are preferably dissolved in an organic solvent with a suitable dehydration catalyst (for example, 4-(4,6- A method of reacting in the presence of dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, carbonylimidazole, phosphorus-based condensing agent, etc.), [III] ditetracarboxylic acid Ester dihalide and the diamine compound containing a specific diamine, Preferably in an organic solvent, an appropriate base (For example, tertiary amines, such as pyridine and triethylamine, sodium hydride, potassium hydride, sodium hydroxide, hydroxide It can be obtained by a method of reacting in the presence of alkali metals such as potassium, sodium and potassium).

The tetracarboxylic acid diester used in said [II] can be obtained by ring-opening tetracarboxylic dianhydride using alcohol etc. The tetracarboxylic acid diester dihalide used in the above [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride.

The polyamic acid ester may have only a dark acid ester structure, and the partial esterification product in which a dark acid structure and a dark acid ester structure coexist may be sufficient as it. Moreover, when polyamic acid ester is obtained as a solution by the said reaction, the solution may be provided for preparation of a liquid crystal aligning agent as it is, and after isolating the polyamic acid ester contained in a reaction solution, you may provide for preparation of a liquid crystal aligning agent. .

<Polyimide>

When the polymer (PI) is a polyimide, the polyimide can be obtained, for example, by imidizing the polyamic acid (P) synthesized as described above by dehydration and ring closure. The polyimide may be a complete imidized product in which all of the dark acid structures of the polyamic acid (P), which is its precursor, have been cyclized by dehydration, or partial dehydration and ring closure of only a part of the amic acid structure, so that the amic acid structure and the imide ring structure coexist. Even a snack is good. It is preferable that the imidation rate is 40 % or more, and, as for a polyimide, it is more preferable that it is 60 to 90 %. This imidation ratio shows the ratio which the number of imide ring structures occupies with respect to the sum total of the number of the male acid structures of a polyimide, and the number of imide ring structures, as a percentage. Moreover, an isoimide ring may be sufficient as a part of an imide ring.

The dehydration ring closure of the polyamic acid (P) is preferably performed by dissolving the polyamic acid (P) in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating as necessary. As a dehydrating agent, acid anhydrides, such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride, can be used, for example. The amount of the dehydrating agent to be used is preferably 0.01 to 20 moles with respect to 1 mole of the amic acid structure of the polyamic acid (P). As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used.

It is preferable that the usage-amount of a dehydration ring closure catalyst shall be 0.01-10 mol with respect to 1 mol of the dehydrating agent used. As an organic solvent to be used, the organic solvent illustrated as what is used for the synthesis|combination of polyamic acid (P) is mentioned. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C, and the reaction time is preferably 1.0 to 120 hours. In this way, the reaction solution containing the obtained polyimide may be used for preparation of a liquid crystal aligning agent as it is, and after isolating a polyimide, you may provide for preparation of a liquid crystal aligning agent.

<Polyurea>

When the polymer (PI) is a polyurea, the polyurea can be obtained by, for example, reacting a diisocyanate compound with a diamine compound containing a specific diamine.

(diisocyanate compound)

Although the diisocyanate compound used for the synthesis|combination of a polyurea is not specifically limited, For example, aliphatic diisocyanate, aromatic diisocyanate, etc. are mentioned. As a specific example of aliphatic diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tetramethylethylene diisocyanate, etc. are mentioned. Specific examples of the aromatic diisocyanate include o-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, toluene diisocyanate (eg, tolylene 2,4-diisocyanate), 1,4-diisocyanate. Socyanic acid-2-methoxybenzene, 2,5-diisocyanate xylenes, 2,2'-bis(4-diisocyanate phenyl)propane, 4,4'-diisocyanate diphenylmethane, 4,4 '-diisocyanate diphenyl ether, 4,4'-diisocyanate diphenylsulfone, 3,3'-diisocyanate diphenylsulfone, 2,2'-diisocyanate benzophenone, etc. are mentioned.

<Polymer (Pm)>

In the monomer (unsaturated bond-containing monomer) constituting the polymer (Pm), examples of the polymerizable carbon-carbon unsaturated bond possessed by the monomer include a (meth)acryloyl group, a vinyl group, a vinylphenyl group, and a maleimide group. have. As a specific example of an unsaturated bond containing monomer, a (meth)acrylic-type compound, an aromatic vinyl compound, a conjugated diene compound, a maleimide group containing compound, etc. are mentioned, for example.

As a specific example of an unsaturated bond containing monomer, As a (meth)acrylic-type compound, For example, Unsaturated carboxylic acids, such as (meth)acrylic acid, (alpha)-ethyl acrylic acid, maleic acid, a fumaric acid, vinylbenzoic acid; (meth)acrylic acid alkyl, (meth)acrylic acid cycloalkyl, (meth)acrylic acid benzyl, (meth)acrylic acid-2-ethylhexyl, (meth)acrylic acid trimethoxysilylpropyl, (meth)acrylic acid 2-hydroxyethyl, ( unsaturated carbonic acid esters such as glycidyl meth)acrylic acid, 3,4-epoxycyclohexylmethyl (meth)acrylic acid, 3,4-epoxybutyl (meth)acrylic acid, and 4-hydroxybutylglycidyl acrylic acid; Unsaturated polyhydric carboxylic acid anhydrides, such as maleic anhydride, are mentioned. Styrene, methylstyrene, hydroxystyrene, divinylbenzene, etc. are mentioned as an aromatic vinyl compound. Examples of the conjugated diene compound include 1,3-butadiene and 2-methyl-1,3-butadiene. Examples of the maleimide group-containing compound include N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide. Moreover, as an unsaturated bond containing monomer, a photo-alignment group containing compound and the compound which has a partial structure (A) are mentioned. At the time of the synthesis|combination of a polymer (Pm), as an unsaturated bond containing monomer, 1 type may be used individually, and you may use it in combination of 2 or more type.

In the synthesis|combination of a polymer (Pm), the polymer which has a partial structure (A) in a side chain can be obtained by using the monomer which has a partial structure (A) as an unsaturated bond containing monomer. Examples of the monomer having the partial structure (A) include compounds in which a hydrogen atom of a hydroxyl group in a hydroxyl group-containing monomer (such as 2-hydroxyethyl (meth)acrylate or hydroxystyrene) is substituted with an acid leaving group. can

As the polymer (Pm), at least one selected from the group consisting of a (meth)acrylic polymer, a styrene polymer, a maleimide polymer, and a styrene-maleimide copolymer can be preferably used.

The polymer (Pm) can be obtained by, for example, polymerizing an unsaturated bond-containing monomer in the presence of a polymerization initiator. Examples of the polymerization initiator to be used include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4). Azo compounds such as -methoxy-2,4-dimethylvaleronitrile) are preferred. It is preferable that the usage-rate of a polymerization initiator sets it as 0.01-30 mass parts with respect to 100 mass parts of all the monomers used for reaction.

The polymerization reaction is preferably carried out in an organic solvent. Examples of the organic solvent used for the reaction include alcohols, ethers, ketones, amides, esters and hydrocarbon compounds, and diethylene glycol ethyl methyl ether and propylene glycol monomethyl ether acetate are preferable. The reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 to 36 hours. It is preferable that the amount (a) of the organic solvent used is such that the total amount (b) of the monomers used for the reaction is 0.1 to 60 mass% with respect to the total amount (a+b) of the reaction solution.

The solution viscosity of the polymer (P) preferably has a solution viscosity of 10-800 mPa·s, more preferably a solution viscosity of 15-500 mPa·s, when a solution having a concentration of 10% by mass is used. . In addition, the solution viscosity (mPa·s) is a concentration of 10% by mass prepared using a positive solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) of the polymer (P). It is the value measured in 25 degreeC about the polymer solution of using E-type rotational viscometer.

The weight average molecular weight (Mw) of the polymer (P) in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 5,000 to 100,000. The molecular weight distribution (Mw/Mn) represented by ratio of Mw and the polystyrene conversion number average molecular weight (Mn) measured by GPC becomes like this. Preferably it is 15 or less, More preferably, it is 10 or less. In addition, the number of polymer (P) made to contain in a liquid crystal aligning agent may be one, or may combine 2 or more types.

<Compound (C)>

The compound (C) is at least one compound selected from the group consisting of polyfunctional aliphatic carboxylic acids, salts of polyfunctional aliphatic carboxylic acids, and thermal acid generators that generate polyfunctional aliphatic carboxylic acids. The compound (C) is a compound having no molecular weight distribution (hereinafter also referred to as a "low molecular weight compound"), and is a compound different from the polymer component having a molecular weight distribution. From a viewpoint of ensuring liquid-crystal orientation and voltage retention characteristic, suppressing the strength fall of the film|membrane formed using this liquid crystal aligning agent, 1,000 or less are preferable, as for the molecular weight of a compound (C), 800 or less are more preferable, 600 or less The following are more preferable.

Compound (C) has two or more in 1 molecule at least 1 sort(s) of group (henceforth "specific functional group F") selected from the group which consists of a carboxy group and the carboxy group produced|generated by heating. It is preferable that it is group which produces|generates a carboxy group by heating at the temperature of 110-180 degreeC, and, as for the carboxy group produced|generated by heating, it is more preferable that it is group represented by following formula (17).

*-COO-R ²¹ … (17)

(In formula (17), R ²¹ is a group that is detached at a temperature of 130 to 180°C. "*" represents a bond.)

The compound (C) has a plurality of specific functional groups F in one molecule. In addition, when a compound (C) has a carboxy group and the carboxy group produced|generated by heating, the number of specific functional group F shows the total number of a carboxy group and the carboxy group produced|generated by heating. Two or more are preferable, as for the number of the specific functional groups F which a compound (C) has in 1 molecule, 2-8 are more preferable, 2-6 are still more preferable, 3-6 are still more preferable. When the number of specific functional groups F is three or more, the improvement effect of the voltage preservation|save characteristic in a liquid crystal element is high, and it is suitable.

The polyfunctional aliphatic carboxylic acid may be an aliphatic compound having a plurality of specific functional groups F in one molecule, and is not particularly limited. In addition, polyfunctional aliphatic carboxylic acid is an aliphatic compound, Specifically, it is a chain|strand or alicyclic compound which does not have an aromatic ring.

Specific examples of the polyfunctional aliphatic carboxylic acid include oxalic acid, malonic acid, methylmalonic acid, fumaric acid, itaconic acid, trans-aconitic acid, iminodiacetic acid, 2-oxoglutaric acid and the like as the bifunctional compound; As a trifunctional compound, citric acid, piperazine citrate hydrate, citric acid 2,6-dimethylpiperidine salt, citric acid ethylenediamine salt, citric acid 4-hydroxypyridine salt, citric acid 3-picolylamine salt, isocyanuric acid tris( 2-carboxyethyl), 1,2,3-propane tricarboxylic acid and the like; As a tetrafunctional compound, meso-butane-1,2,3,4-tetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, tetrahydrofuran-2,3,4,5-tetracarbon Acid, 2,3,5-tricarboxycyclopentylacetic acid, ethylenediaminetetraacetic acid, 1,3-propanediamine-N,N,N',N'-4acetic acid, trans-1,2-cyclohexanediaminetetraacetic acid monohydrate and the like; Examples of the pentafunctional compound include diethylenetriaminepentaacetic acid; Examples of the hexafunctional compound include triethylenetetramine-N,N,N',N'',N''',N'''-6acetic acid and the like.

As a specific example of the salt of polyfunctional aliphatic carboxylic acid, the salt of the said compound illustrated as a specific example of polyfunctional aliphatic carboxylic acid is mentioned. Examples of carboxyl counter ions include Li ⁺ , Na ⁺ , K ⁺ , Cs ⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ , Pb ²⁺ , Al ³⁺ , La ³⁺ , Ce ³⁺ , Y ³⁺ , Yb ³⁺ , Gd ³⁺ , NH _4-t Q _t ⁺ (However, Q represents a hydrocarbon group having 1 to 20 carbon atoms. t represents an integer from 0 to 4. When t is 2 to 4, a plurality of Qs are the same or different) and the like. Among these, a monovalent cation is preferable, NH _4-t Q _t ⁺ is more preferable, and a tertiary ammonium ion is still more preferable.

As a thermal acid generator which generate|occur|produces polyfunctional aliphatic carboxylic acid, the compound in which the carboxy group was protected is mentioned in the said compound illustrated as a specific example of polyfunctional aliphatic carboxylic acid. Specific examples of the compound include triammonium citrate.

As the compound (C), polyfunctional carboxylic acids or salts thereof can be preferably used among the above from the viewpoint of versatility and high degree of freedom in selectivity. In view of the high effect of improving the voltage preservation characteristics of the liquid crystal element, aliphatic compounds having three or more specific functional groups F in one molecule are preferred, and trifunctional or higher chain aliphatic carboxylic acids or salts thereof are more preferred. .

In addition, when the polymer (P) is polyamic acid, if a salt such as an amine or pyridine is used as the compound (C), the carboxylic acid is volatilized and the imidation reaction may be accelerated by the remaining amine or pyridine. .

This liquid crystal aligning agent WHEREIN: Content of a compound (C) is 5 mass parts with respect to 100 mass parts of polymers (P) contained in this liquid crystal aligning agent from a viewpoint of fully acquiring the improvement effect of liquid-crystal orientation and a voltage retention characteristic. The above is preferable, 10 mass parts or more are more preferable, and 20 mass parts or more are still more preferable. Moreover, from a viewpoint of ensuring the liquid-crystal orientation and voltage retention characteristic of a liquid crystal element, as for content of a compound (C), 300 mass parts or less are preferable with respect to 100 mass parts of polymer (P) contained in this liquid crystal aligning agent, 250 mass parts or less are more preferable, 200 mass parts or less are still more preferable, and 150 mass parts or less are still more preferable. As a compound (C), you may use individually by 1 type, and may use it in combination of 2 or more type.

<solvent>

As the solvent, an organic solvent can be preferably used. As the organic solvent to be used, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ -Butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), ethylene glycol monomethyl ether, butyl lactate, acetic acid Butyl, methyl methoxypropionate, 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, diisobutyl ketone, isoamyl propionate, isoamyl isobutylate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. are mentioned. These can be used individually or in mixture of 2 or more types.

Contrast with the solvent contained in a liquid crystal aligning agent WHEREIN: It is preferable that a compound (C) has low volatility, and specifically, it is a compound more difficult to vaporize than the solvent contained in a liquid crystal aligning agent under temperature conditions of 180 degrees C or less. it is preferable When a compound (C) is a compound which is hard to vaporize in the temperature which is 180 degrees C or less rather than the solvent contained in a liquid crystal aligning agent, vaporization of a compound (C) is suppressed, when forming a liquid crystal aligning film, and compound (C) in an alignment film It can be made to remain|survive and it is suitable at the point which can fully function as an acid catalyst. In addition, it can discriminate|determine that a compound (C) is a compound more difficult to vaporize than the solvent contained in a liquid crystal aligning agent with the vaporization rate of both in temperature conditions of 180 degrees C or less.

From this point of view, the compound (C) is preferably a compound having no boiling point in a temperature range of 180° C. or less under the conditions of 1 atm. In addition, as a compound which does not have a boiling point in the temperature range of 180 degrees C or less, the boiling point in 1 atmospheric pressure is higher than 180 degreeC, and under the conditions of 1 atmospheric pressure, it is uniquely defined within the temperature range of 180 degrees C or less. Compounds with no boiling point are included.

<Other ingredients>

The liquid crystal aligning agent of this indication may contain further components (henceforth "other components") other than a polymer (P), a compound (C), and a solvent. As other components, for example, a polymer having no partial structure (A) (hereinafter also referred to as "other polymer"), a compound having one or more epoxy groups in a molecule, a functional silane compound, one or more in a molecule The compound which has a (meth)acryloyl group, antioxidant, a metal chelate compound, a hardening accelerator, surfactant, a filler, a dispersing agent, a photosensitizer, etc. are mentioned. These compounding ratios can be suitably selected according to each compound in the range which does not impair the effect of this indication.

(other polymers)

The main skeleton of the other polymer is not particularly limited, and for example, polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole A precursor, polybenzoxazole, a cellulose derivative, polyacetal, a (meth)acrylic-type polymer, a styrene-type polymer, a maleimide-type polymer, a styrene-maleimide-type copolymer, etc. are mentioned. From the viewpoint of obtaining a highly reliable liquid crystal device, another polymer is a polymer comprising structural units derived from polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and a monomer having a polymerizable unsaturated carbon-carbon bond. At least one selected from the group consisting of is preferable. Examples of the polymer containing a structural unit derived from a monomer having a polymerizable unsaturated carbon-carbon bond include a (meth)acrylic polymer, a styrene polymer, a maleimide polymer, and a styrene-maleimide copolymer.

When forming a liquid crystal aligning film by the photo-alignment method, you may use the polymer which has a photo-alignment group as another polymer. A photoalignable group is a functional group which provides anisotropy to a film|membrane by the photoisomerization reaction by light irradiation, a photodimerization reaction, a photolysis reaction, or a phototranslocation reaction. Specific examples of the photo-aligning group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, cyclobutane or a derivative thereof as a basis A cyclobutane structure-containing group including as a skeleton, a chalcone-containing group including chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group including benzophenone or a derivative thereof as a basic skeleton, phenylbenzoate or a derivative thereof as a basic skeleton and a coumarin-containing group including a phenylbenzoate-containing group and coumarin or a derivative thereof as a basic skeleton.

When making a liquid crystal aligning agent contain another polymer, 1 mass % or more is preferable with respect to the total amount of a polymer (P) and another polymer, and, as for content of another polymer, 2 mass % or more is more preferable. Moreover, 95 mass % or less is preferable with respect to the total amount of a polymer (P) and another polymer, and, as for content of another polymer, 90 mass % or less is more preferable. As another polymer, you may use individually by 1 type, and may use it in combination of 2 or more type.

Although the solid content concentration (ratio which the total mass of components other than the solvent of a liquid crystal aligning agent occupies to the total mass of a liquid crystal aligning agent) in a liquid crystal aligning agent considers a viscosity, volatility, etc. and is suitably selected, Preferably it is 1-10 It is the range of mass %. That is, a liquid crystal aligning agent is apply|coated to the board|substrate surface so that it may mention later, Preferably, when heated, the coating film used as the coating film which is a liquid crystal aligning film or a liquid crystal aligning film is formed. At this time, the film thickness of a coating film can fully be ensured as solid content concentration is 1 mass % or more, and it is suitable at the point which is easy to obtain a favorable liquid crystal aligning film. Moreover, while being able to obtain a favorable liquid crystal aligning film without the film thickness of a coating film becoming too excessive that solid content concentration is 10 mass % or less, the viscosity of a liquid crystal aligning agent can be ensured suitably, and applicability|paintability can be made favorable. .

Preferably the content rate of the polymer (P) in a liquid crystal aligning agent with respect to a total of 100 mass parts of solid components in a liquid crystal aligning agent (namely, components other than a solvent) from a viewpoint of fully acquiring the effect of this indication, Preferably it is 10 mass It is more than part, More preferably, it is 20 mass parts or more, More preferably, it is 50 mass parts or more.

《Liquid crystal alignment film and liquid crystal element》

The liquid crystal aligning film of this indication is formed with the liquid crystal aligning agent prepared as mentioned above. Moreover, the liquid crystal element of this indication is equipped with the liquid crystal aligning film formed using the liquid crystal aligning agent demonstrated above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type (VA-MVA type, VA-PVA type, etc.) including), IPS (In-Plane Switching) type, FFS (Fringe Field Switching) type, OCB (Optically Compensated Bend) type, etc. can be applied to various modes. A liquid crystal element can be manufactured by the method including the following steps 1 - 3, for example. In step 1, the substrate used differs depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

(Step 1: Formation of a coating film)

First, a liquid crystal aligning agent is apply|coated on a board|substrate, Preferably a coating film is formed on a board|substrate by heating an application surface. As a board|substrate, For example, glass, such as float glass and soda glass; A transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin) can be used. Examples of the transparent conductive film formed on one surface of the substrate include an NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Corporation in the United States), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), and the like. is available. When manufacturing a TN-type, STN-type, or VA-type liquid crystal element, two substrates on which the patterned transparent conductive film is formed are used. On the other hand, when manufacturing an IPS-type or FFS-type liquid crystal element, a substrate on which an electrode made of a transparent conductive film or metal film patterned in a comb-tooth shape is formed, and a counter substrate on which no electrode is formed. As the metal film, for example, a film made of a metal such as chromium can be used. On the electrode formation surface, application|coating of the liquid crystal aligning agent to a board|substrate becomes like this. Preferably the offset printing method, the spin coating method, the roll coater method, or the inkjet printing method perform.

After apply|coating a liquid crystal aligning agent, for purposes, such as liquid flow prevention of the apply|coated liquid crystal aligning agent, Preferably, preliminary heating (prebaking) is performed. Prebaking temperature becomes like this. Preferably it is 30-150 degreeC, More preferably, it is 40-120 degreeC. Prebaking time becomes like this. Preferably it is 0.25 to 10 minutes.

After that, the solvent is completely removed and, if necessary, a calcination (post-baking) step is performed for the purpose of thermal imidization of the amic acid structure present in the polymer. The firing temperature (post-baking temperature) at this time is preferably 180 ° C. or less from the viewpoint of suppressing deterioration such as fading due to high temperature when forming a liquid crystal aligning film on the color filter, and from the viewpoint of reducing the environmental load, 170 degrees C or less is more preferable, and 160 degrees C or less is still more preferable. Moreover, 80 degreeC or more is preferable from a viewpoint of suppressing that liquid-crystal orientation and reliability fall under the influence of the solvent component which remained in a film|membrane, and, as for post-baking temperature, 90 degreeC or more is more preferable. Post-baking time becomes like this. Preferably it is 5-150 minutes. Thus, the film thickness of the film|membrane formed becomes like this. Preferably it is 0.001-1 micrometer. After apply|coating a liquid crystal aligning agent on a board|substrate, the coating film used as a liquid crystal aligning film or a liquid crystal aligning film is formed by removing an organic solvent.

(Step 2: Orientation treatment)

When manufacturing the liquid crystal element of TN type, STN type, IPS type, or FFS type, the process (alignment process) which provides liquid-crystal orientation ability to the coating film formed in the said process 1 is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. It is preferable to use the rubbing process which rubs the surface of the coating film formed on the board|substrate with cotton etc. as an orientation process, or the photo-alignment process which irradiates light to a coating film and provides liquid-crystal orientation ability. When manufacturing the liquid crystal element of a vertical alignment type, you may use the coating film formed in the said process 1 as it is as a liquid crystal aligning film, and in order to further improve liquid-crystal orientation ability, you may orientation-process with respect to a coating film.

The light irradiation in a photo-alignment process is a method of irradiating with respect to the coating film after a post-baking process, the method of irradiating with respect to the coating film after a pre-baking process and before a post-baking process, a pre-baking process, and a post-baking process in at least any of a coating film It can be carried out by a method of irradiating the coating film during heating, or the like. A photo-alignment process WHEREIN: As radiation irradiated to a coating film, the ultraviolet-ray and visible light containing the light of a wavelength of 150-800 nm can be used, for example. Preferably, it is an ultraviolet-ray containing light of a wavelength of 200-400 nm. When the radiation is polarized light, it may be linearly polarized or partially polarized. In the case where the radiation to be used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. When irradiating a non-polarized radiation, the direction of irradiation is made into an oblique direction.

As a light source to be used, 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 excimer laser etc. can be used, for example. The radiation dose is preferably 400 to 20,000 J/m 2 , more preferably 1,000 to 5,000 J/m 2 . Light irradiation to the coating film may be performed while heating the coating film in order to increase the reactivity.

In the case of manufacture of a liquid crystal aligning film, you may further heat the organic film to which the light irradiation process was given. It is preferable at the point which can obtain the liquid crystal element by which the liquid-crystal orientation was further improved by this heat processing (heat reorientation). Post-baking may be sufficient as this heating, and the heat processing performed after post-baking separately from post-baking may be sufficient as it. From the viewpoint of promoting reorientation of molecular chains by heating, the heating temperature is preferably 120°C or higher, more preferably 130°C or higher, and still more preferably 140°C or higher. Moreover, it is preferable to set it as 180 degrees C or less, and, as for the heating temperature in the heat processing after light irradiation, it is more preferable to set it as 170 degrees C or less. Heating time becomes like this. Preferably it is 5 to 200 minutes, More preferably, it is 10 to 60 minutes.

In the case of manufacture of a liquid crystal aligning film, the contact process of making the organic film to which the light irradiation process was given contact with water, a water-soluble organic solvent, or the mixed solvent of water and a water-soluble organic solvent may be included further. Examples of the water-soluble organic solvent include methanol, ethanol, 1-propanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone. can be heard Examples of the method for contacting the organic film with the solvent include, but are not limited to, spray (spray) treatment, shower treatment, immersion treatment, and puddle treatment. Although the contact time in particular of an organic film and a solvent is not limited, For example, it is 5 second - 15 minutes. You may heat-process an organic film after a contact process.

(Step 3: Construction of a liquid crystal cell)

A liquid crystal cell is manufactured by preparing two board|substrates with a liquid crystal aligning film as mentioned above, and arrange|positioning a liquid crystal between the board|substrates of 2 sheets opposingly arranged. In order to manufacture a liquid crystal cell, for example, (1) two board|substrates are opposingly arrange|positioned through a gap|interval (spacer) so that a liquid crystal aligning film may oppose, and the peripheral part of two board|substrates is bonded using a sealing compound, The board|substrate surface And after injecting and filling a liquid crystal in the cell gap partitioned by the sealing compound, the method of sealing an injection hole, (2) apply|coating a sealing compound to the predetermined place on one board|substrate on which the liquid crystal aligning film was formed, and further a liquid crystal aligning film After dripping a liquid crystal to several predetermined places on a surface, while bonding the other board|substrate so that a liquid crystal aligning film may oppose, the method (ODF system) etc. which spread a liquid crystal over the whole surface of a board|substrate are mentioned. About the manufactured liquid crystal cell, it is preferable to remove the flow orientation at the time of liquid-crystal filling by performing the process of further cooling to room temperature, after heating to the temperature which the used liquid crystal takes an isotropic phase.

As a sealing agent, the epoxy resin etc. containing the aluminum oxide sphere as a hardening|curing agent and a spacer can be used, for example. As a spacer, a photo spacer, a bead spacer, etc. can be used.

As the liquid crystal, any of a positive type and a negative type may be used. When a negative liquid crystal is used in an IPS type|mold and FFS type liquid crystal element, it is preferable at the point which can make small the transmission loss in an electrode upper part, and can aim at the contrast improvement. Moreover, as a liquid crystal to be used, a nematic liquid crystal and a smectic liquid crystal are mentioned, Among these, a nematic liquid crystal is preferable. As the nematic liquid crystal, for example, Cipher base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, di An oxane-based liquid crystal, a bicyclooctane-based liquid crystal, a cuban-based liquid crystal, or the like can be used. Moreover, you may add and use a cholesteric liquid crystal, a chiral agent, a ferroelectric liquid crystal, etc. to these liquid crystals, for example.

Then, a polarizing plate is bonded to the outer surface of a liquid crystal cell as needed. As a polarizing plate, the polarizing plate which sandwiched the polarizing film called "H film" which absorbed iodine while extending|stretching orienting polyvinyl alcohol, with a cellulose acetate protective film, or the polarizing plate which consists of H film itself is mentioned. Thereby, a liquid crystal element is obtained.

Moreover, by using this liquid crystal aligning agent, even when a liquid crystal aligning film is formed by 180 degreeC or less low-temperature baking, although the reason that the liquid crystal element with favorable liquid-crystal orientation and a voltage preservation characteristic was obtained is not certain, the following points are inferred . By introducing into the polymer a structure in which a bulky group such as an acid-leaving group is bonded to a nitrogen atom and/or an oxygen atom, the solubility of the polymer can be improved, and it is used as a low-boiling/low-polarity solvent compared to the case where it does not have an acid-leaving group. It is thought that the solubility of can be quantified. In addition, when the acid leaving group in the polymer is bonded to a nitrogen atom and/or an oxygen atom, the desorption reaction is accelerated by the presence of the compound (C) during film formation, whereby heating for film formation is performed at a relatively low temperature. Edo acid leaving group is easy to detach|desorb, and -NH- and/or a hydroxyl group are generated. Thereby, it is possible to suppress that the acid leaving group remains in the liquid crystal aligning film, and as a result, the alignment of the liquid crystal at the interface of the liquid crystal aligning film is disturbed, or the liquid crystal aligning film becomes sparse, and the voltage preservation characteristic can be suppressed. I think there was

The liquid crystal element of the present disclosure can be effectively applied to various uses, for example, a watch, a portable game machine, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, a smart phone, It can be used for various display apparatuses, such as various monitors, a liquid crystal television, and an information display, a light control film, etc. Moreover, the liquid crystal element formed using the liquid crystal aligning agent of this indication can also be applied to optical films, such as retardation film.

(Example)

Hereinafter, although an Example demonstrates more concretely, this invention is not limited to these Examples.

<Structure and Abbreviation of Compound>

The structure and abbreviation of the main compound used in the following examples are as follows.

[Tetracarboxylic acid dianhydride]

TA-1; 1,2,3,4-Cyclobutanetetracarboxylic acid dianhydride

TA-2; (1R,2R,3S,4S)-1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride

TA-3; 2,3,5-tricarboxycyclopentylacetic acid dianhydride

[diamine]

DA-1; N,N'-bis(5-aminopyridin-2-yl)-N,N'-di(tert-butoxycarbonyl)ethylenediamine

DA-2; N1,N6-bis(4-aminophenethyl)-N1,N6-di(tert-butoxycarbonyl)adipamide

DA-3; 4-amino-N-(4-aminophenyl)-N-(tert-butoxycarbonyl)benzamide

DA-4; N,N'-bis(4-aminophenethyl)-N-(tert-butoxycarbonyl)urea

DA-5; 2,2'-dimethylbenzidine

DA-6; 4,4'-diaminodiphenylmethane

DA-7; 4,4'-diaminodiphenyl ether

DA-8; 3,5-diaminobenzoic acid

[polymer]

PS-1; Poly (4-hydroxystyrene-co-4-tert-butoxycarbonyloxystyrene)

PS-2; Poly(4-hydroxystyrene-co-4-tert-butyloxystyrene)

[acid catalyst]

C-1; citric acid

C-2; oxalic acid

C-3; malonic acid

C-4; fumaric acid

C-5; trans-aconitic acid

C-6; Tris isocyanuric acid (2-carboxyethyl)

C-7; acetic acid

C-8; octanoic acid

C-9; pyruvic acid

C-10; glycolic acid

C-11; p-hydroxybenzoic acid

C-12; p-toluenesulfonic acid

C-13; polyacrylic acid

[solvent]

NMP; N-methyl-2-pyrrolidone

GBL; γ-butyrolactone

BC; Butyl Cellosolve

DAA; diacetone alcohol

DEDG: diethylene glycol diethyl ether

<Synthesis and Evaluation of Polymers>

In the following Synthesis Examples 1 to 7, polymers were synthesized, respectively. In addition, in the following example, the weight average molecular weight (Mw) of a polymer and the imidation rate of the polyimide in a polymer solution were measured with the following method.

[Weight Average Molecular Weight (Mw) of Polymer]

A weight average molecular weight (Mw) is a polystyrene conversion value measured by GPC in the following conditions.

Column: TSKgelGRCXLII manufactured by Tosoh Corporation

Solvent: tetrahydrofuran

Temperature: 40℃

Pressure: 68kgf/cm2

[Imidation rate of polyimide]

A polyimide solution was poured into pure water, and the obtained precipitate was dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained < ¹ >H-NMR spectrum (400 MHz), the imidation rate [%] was calculated|required by following formula (1).

Imidization ratio [%] = (1-(A ₁ /(A ₂ ×α))) × 100 … (One)

(In formula (1), A ₁ is the peak area derived from the proton of the amide group appearing around 10 ppm of the chemical shift, A ₂ is the peak area derived from the proton of the aromatic group appearing around the chemical shift of 6 to 9 ppm, α is the polymer It is the ratio of the number of protons of the aromatic group to one proton of the amide group in the precursor (polyamic acid) of

[Synthesis Example 1]

Diamine (70 molar parts of diamine (DA-1) and 30 molar parts of diamine (DA-5)) was dissolved in NMP, 0.95 molar equivalent of acid dianhydride (TA-2) was added with respect to the total amount of diamine, and reacted at room temperature for 6 hours was carried out to obtain a solution of polyamic acid. 0.80 molar equivalent of 1-methylpiperidine and acetic anhydride were added to the obtained solution as a dehydrating agent with respect to the carboxy group of polyamic acid, and it heat-stirred at 60 degreeC for 3 hours. With respect to the obtained solution, vacuum concentration and dilution by NMP were repeated, and the 10 mass % solution of the polyimide (PI-1) which has a partial structure represented by a following formula (PI-1) was obtained. The imidation rate of polyimide (PI-1) was 78%.

[Synthesis Example 2]

Diamine (diamine (DA-2) 100 mol parts) is dissolved in NMP, 0.95 molar equivalent of acid dianhydride (TA-1) is added with respect to the total amount of diamine, and the reaction is performed at room temperature for 6 hours, the following formula (PI-2) ), a 15% by mass solution of polyamic acid (PI-2) having a partial structure was obtained.

[Synthesis Examples 3 to 6]

Polyamic acids (PI-3 to PI-6) were obtained in the same manner as in Synthesis Example 2, except that the types and molar ratios of the acid dianhydride and diamine were changed as shown in Table 1 below, respectively. In addition, the numerical value in Table 1 shows the use ratio (mol%) of each compound with respect to the total amount (100 mol%) of the acid dianhydride used for the synthesis|combination about an acid dianhydride, About diamine, the diamine used for synthesis|combination The usage ratio (mol%) of each compound with respect to the total amount (100 mol%) is shown.

[Synthesis Example 7]

In a 100 mL two-neck flask under nitrogen, 6.38 g of a compound represented by the following formula (M-1) as a polymerization monomer, and 1.90 g of 4-(glycidyloxymethyl) styrene (a compound represented by the following formula (M-2)) and 0.86 g of methacrylic acid, 0.46 g of 2,2'-azobis (2,4-dimethylvaleronitrile) as a radical polymerization initiator, and 40 ml of N-methyl-2-pyrrolidone (NMP) as a solvent, , polymerization was carried out at 70°C for 6 hours. After re-precipitation in methanol, the target polymer (PMI-1) was obtained by filtering a precipitate and vacuum-drying at room temperature for 8 hours. The weight average molecular weight (Mw) measured in polystyrene conversion by GPC was 30000, and molecular weight distribution (Mw/Mn) was 2.0.

<Preparation and evaluation of liquid crystal aligning agent>

[Example 1: Photo-alignment FFS type liquid crystal display device]

(1) Preparation of liquid crystal aligning agent

By diluting the polymer and additive component (in terms of solid content: 100 parts by mass of polyimide (PI-1) and 100 parts by mass of compound (C-1)) with NMP, GBL, DAA and BC, the solid content concentration of the polymer component is 4.0 The mass % and solvent composition ratio obtained the solution used as NMP:GBL:DAA:BC=30:30:30:10 (mass ratio). A liquid crystal aligning agent (AL-1) was prepared by filtering this solution with the filter with a hole diameter of 0.2 micrometer.

(2) Formation of a liquid crystal aligning film by a photo-alignment method

The liquid crystal aligning agent (AL-1) prepared in said (1) on each surface of the glass substrate in which the flat electrode, the insulating layer, and the comb-tooth-shaped electrode were laminated|stacked on single side|surface in this order, and the opposing glass substrate in which an electrode is not formed. ) was applied using a spin coater, heated for 1 minute on a hot plate at 80 ° C., and then heated (1 st baking) for 30 minutes in an oven at 150 ° C. A coating film having a thickness of 100 nm was formed. The surface of the coating film was subjected to photo-alignment treatment by irradiating 400 mJ/cm 2 of ultraviolet rays containing a linearly polarized 254 nm bright line from the substrate normal direction using an Hg-Xe lamp. The coating film to which this photo-alignment process was given was heat-processed by heating (2nd baking) for 30 minutes in 150 degreeC oven which substituted the inside of furnace with nitrogen, and the liquid crystal aligning film was formed.

(3) Manufacturing of FFS type liquid crystal display element

On the outer periphery of the surface having one liquid crystal aligning film in the substrate produced in (2) above, an epoxy resin adhesive containing an aluminum oxide sphere having a diameter of 3.5 µm with a liquid crystal injection port left was applied with a dispenser, and then a liquid crystal aligning film of a pair of substrates The surfaces having , were opposed, pressed so that the orientation treatment direction of each substrate was antiparallel, and the adhesive was thermosetted at 150° C. for 1 hour. Next, after filling the gap between the substrates from the liquid crystal injection port with negative nematic liquid crystal (Merck, MJ20195NCMP), the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation at the time of liquid crystal injection, after heating at 120 degreeC, it cooled slowly to room temperature. Next, the FFS-type liquid crystal display element was manufactured by bonding a polarizing plate to the outer both surfaces of a board|substrate so that the polarization direction may mutually be orthogonal, and may make the orientation processing direction of a liquid crystal aligning film and 45 degree angle.

(4) Evaluation of liquid crystal orientation

About the liquid crystal display element manufactured in said (3), the presence or absence of the abnormal domain in the change of the contrast when the voltage of 5 V was turned ON/OFF (applied/released) was observed with the microscope at 50 times magnification. In evaluation, the case where an abnormal domain was not observed was made into "good|favorableness", and the case where an abnormal domain was observed was made into "poor". As a result, in this Example, it was evaluation of "good|favorableness".

(5) Evaluation of voltage preservation characteristics

About the liquid crystal display element manufactured in said (3), after applying the voltage of 1V with the application time of 60 microseconds, and the span of 1000 milliseconds, the voltage retention rate 1000 milliseconds after application release was measured. Evaluation made 90 % or more "good", 80 % or more and less than 90 % "good", and less than 80 % as "poor" for 90 % or more. As a result, in this Example, it was evaluation of "excellence". In addition, the model name "VHR-1" by the Toyo Technica Corporation was used as a measuring apparatus of voltage retention.

[Examples 2 to 11, Comparative Examples 1 to 11, and Reference Example 1]

In Example 1, the components contained in the liquid crystal aligning agent and the heating temperature (heating temperature of the 1st baking and the 2nd baking) at the time of forming the liquid crystal aligning film were changed as shown in Table 2 below, except for Example 1 Similarly, while preparing a liquid crystal aligning agent and forming a liquid crystal aligning film by the photo-alignment method, the FFS-type liquid crystal display element was manufactured and various evaluation was performed. The evaluation results are shown in Table 2 below. In addition, the reference example 1 is a case where the heating temperature at the time of formation of a liquid crystal aligning film is 230 degreeC using the liquid crystal aligning agent (AL-2) similar to the comparative examples 1 and 2.

[Example 12: Rubbing Orientation FFS Liquid Crystal Display Element]

(1) Preparation of liquid crystal aligning agent

Polymer and additive component (in terms of solid content: 40 parts by mass of polyamic acid (PI-2), 60 parts by mass of polyamic acid (PI-5), and 50 parts by mass of compound (C-1)) to NMP, GBL, DAA and BC By diluting by , 4.0 mass % of solid content concentration of a polymer component and solvent composition ratio obtained the solution used as NMP:GBL:DAA:BC=30:30:30:10 (mass ratio). A liquid crystal aligning agent (AL-20) was prepared by filtering this solution with the filter with a hole diameter of 0.2 micrometer.

(2) Formation of liquid crystal aligning film by rubbing method

The liquid crystal aligning agent (AL-20) prepared in said (1) on each surface of the glass substrate in which the flat electrode, the insulating layer, and the comb-tooth electrode were laminated|stacked on one side in this order, and the opposing glass substrate in which an electrode is not formed. ) was applied using a spin coater, heated for 1 minute on a hot plate at 80 ° C., and then heated (1st baking) in an oven at 150 ° C in which the inside of the furnace was purged with nitrogen (1st baking) to obtain an average film thickness of 100 nm. A coating film was formed. Using a rubbing machine having a roll wound with nylon cloth on the surface of the coating film, the rubbing treatment was performed twice at a roll rotation speed of 1000 rpm, a stage movement speed of 30 mm/sec, and a bushy foot press-in length of 0.3 mm. After ultrasonically cleaning the coating film to which this rubbing orientation process was given for 1 minute in ultrapure water, it dried in 100 degreeC oven for 10 minutes and formed the liquid crystal aligning film.

(3) Manufacturing of FFS type liquid crystal display element

About a pair of board|substrates which have a liquid crystal aligning film produced by said (2), it carried out similarly to Example 1, and manufactured the FFS-type liquid crystal display element.

(4) Evaluation of liquid crystal orientation

About the FFS-type liquid crystal display element manufactured by said (3), it carried out similarly to Example 1, and evaluated the liquid-crystal orientation. As a result, in the present Example, it was evaluation of "good|favorableness".

(5) Evaluation of voltage preservation characteristics

About the FFS-type liquid crystal display element manufactured by said (3), it carried out similarly to Example 1, and evaluated the voltage preservation|save characteristic. As a result, in this Example, it was evaluation of "good|favorableness".

[Examples 13 and 14]

In the said Example 12, except having changed the component contained in a liquid crystal aligning agent as shown in following Table 2, it carried out similarly to Example 12, while preparing a liquid crystal aligning agent and forming a liquid crystal aligning film by the rubbing method , FFS-type liquid crystal display elements were manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below.

[Example 15: Photo-alignment VA type liquid crystal display element]

(1) Preparation of liquid crystal aligning agent

Polymer and additive component (in terms of solid content: 90 parts by mass of polyamic acid (PI-3), 10 parts by mass of polymer (PMI-1), and 50 parts by mass of compound (C-1)) by NMP, GBL, DEDG and BC By diluting, 4.0 mass % of solid content concentration of a polymer component and solvent composition ratio obtained the solution used as NMP:GBL:DEDG:BC=30:30:30:10 (mass ratio). A liquid crystal aligning agent (AL-24) was prepared by filtering this solution with the filter with a hole diameter of 0.2 micrometer.

(2) Formation of a liquid crystal aligning film by a photo-alignment method

On each electrode surface of two glass substrates having ITO electrodes, the liquid crystal aligning agent (AL-24) prepared in (1) above was applied using a spin coater, and heated on a hot plate at 80°C for 1 minute. Then, heating (1st baking) was performed for 30 minutes in 150 degreeC oven which substituted the inside of the furnace with nitrogen, and the coating film with an average film thickness of 100 nm was formed. The surface of this coating film was subjected to photo-alignment treatment by irradiating 20 mJ/cm 2 of ultraviolet rays including a linearly polarized 313 nm bright line from a direction inclined by 40° from the substrate normal line using an Hg-Xe lamp to form a liquid crystal alignment film. did.

(3) Manufacture of VA type liquid crystal display element

On the outer periphery of the surface having a liquid crystal aligning film of one of the substrates produced in (2) above, an epoxy resin adhesive containing an aluminum oxide sphere having a diameter of 3.5 µm was applied with a dispenser, leaving the liquid crystal injection port, and then the liquid crystal of a pair of substrates The surfaces having the alignment film were faced to each other, and the respective substrates were pressed so that the projection direction of the optical axis of the optical axis to the substrate surface was antiparallel, and the adhesive was thermosetted at 150° C. for 1 hour.

Next, after filling the gap between the substrates from the liquid crystal injection port with negative nematic liquid crystal (Merck, MLC-6608), the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation at the time of liquid crystal injection, after heating at 120 degreeC, it cooled slowly to room temperature. Next, a VA-type liquid crystal display element was manufactured by bonding a polarizing plate to the outer both surfaces of a board|substrate so that the polarization direction may mutually be orthogonal, and the orientation treatment direction of a liquid crystal aligning film may make an angle of 45 degrees.

(4) Evaluation of liquid crystal orientation

About the VA type liquid crystal display element manufactured by said (3), it carried out similarly to Example 1, and evaluated the liquid-crystal orientation. As a result, in the present Example, it was evaluation of "good|favorableness".

(5) Evaluation of voltage preservation characteristics

About the VA type liquid crystal display element manufactured by said (3), it carried out similarly to Example 1, and evaluated the voltage preservation|save characteristic. As a result, in the present Example, it was evaluation of "good|favorableness".

[Example 16]

In Example 15, except that the component contained in the liquid crystal aligning agent was changed as shown in Table 2 below, in the same manner as in Example 15, preparing a liquid crystal aligning agent and forming a liquid crystal aligning film by a photo-alignment method; Together, a VA-type liquid crystal display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 2 below.

In Table 2, mass ratio of each component of a liquid crystal aligning agent shows the compounding ratio (mass part) of each compound with respect to a total of 100 mass parts of the polymer component used for preparation of a liquid crystal aligning agent.

As shown in Table 2, even when the liquid crystal aligning agent of Examples 1-16 containing a polymer (P) and a compound (C) makes the heating temperature at the time of formation of a liquid crystal aligning film 180 degrees C or less, a liquid crystal display element was "excellent" or "good" in the liquid-crystal orientation and voltage retention characteristic of . On the other hand, when the liquid crystal aligning agent of Comparative Examples 1-11 which does not contain a compound (C) makes the heating temperature at the time of formation of a liquid crystal aligning film 180 degrees C or less, the liquid-crystal orientation of a liquid crystal display element, and a voltage preservation characteristic At least one of them was "defective", and it was a result inferior to an Example.

Although the reason this result was obtained is not certain, when a liquid crystal aligning agent contains a polymer (P) and a compound (C), the acid leaving group which the polymer (P) has at the time of formation of a liquid crystal aligning film detach|desorbs, and -NH- group and/or conversion to a hydroxyl group increases the mesogen density (interaction with liquid crystal molecules) in the alignment film at the alignment film interface, and the interior of the alignment film becomes dense. Accordingly, it is inferred that the liquid crystal alignment and voltage preservation characteristics are improved. do.

On the other hand, in Comparative Example 4 using a polymer (PI-6) having a carboxy group instead of the compound (C), it is inferred that the function of the acid catalyst was not expressed. This is considered to be because, in order for a compound having a carboxy group to function as an acid catalyst, it is necessary for the compound to diffuse in the vicinity of an acid leaving group and to act. In a polymer having a carboxy group, diffusion is slow and compatibility is low. Moreover, it is thought that it did not function as an acid catalyst also in Comparative Examples 9-11 using aromatic carboxylic acid or sulfonic acid instead of compound (C).

Further, when the polymer (P) is a polymer (PI-1) having a basic functional group and the compound (C) is a trifunctional acid catalyst (C-1, C-5, C-6), the compound (C) ), except for Example 4 in which the addition amount was relatively small, the voltage preservation characteristics became "excellent". It is inferred that this is because the polymer (P) crosslinked ions (physical crosslinking) through the compound (C) remaining in the film by acid-base interaction, and the ion mobility in the film was suppressed.

By the above, according to this liquid crystal aligning agent containing a polymer (P) and a compound (C), even when the heating temperature at the time of film formation is made into the temperature of 180 degrees C or less, a liquid crystal element with favorable liquid-crystal orientation and voltage retention characteristic. It turned out that the liquid crystal aligning film from which can be obtained can be formed.

Claims (8)

A polymer (P) having a partial structure (A) in which an acid leaving group is bonded to at least any of a nitrogen atom and an oxygen atom;
Compound (C) which is at least one selected from the group consisting of polyfunctional aliphatic carboxylic acids, salts of polyfunctional aliphatic carboxylic acids, and thermal acid generators that generate polyfunctional aliphatic carboxylic acids (except for polymers) , and,
solvent
containing, a liquid crystal aligning agent. According to claim 1,
The polymer (P) is a group consisting of a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), a partial structure represented by the following formula (3), and a partial structure represented by the following formula (4) The liquid crystal aligning agent which is a polymer which has at least 1 sort(s) chosen from.

(In Formulas (1) to (4), R ¹ to R ⁵ are each independently a monovalent hydrocarbon group; Y ¹ is a carbon atom or a silicon atom; R ⁶ and R ⁷ are: ) or (ii) is satisfied; "*" indicates that it is a bond.
(i) R ⁶ is a hydrogen atom or a monovalent hydrocarbon group; R ⁷ is a monovalent hydrocarbon group or a group including -O- between the carbon-carbon bonds of the monovalent hydrocarbon group
(ii) R ⁶ and R ⁷ are taken together to represent a ring structure constituted together with the carbon atom to which R ⁶ is bonded and the oxygen atom to which R ⁷ is bonded) The method of claim 1,
The said polymer (P) is at least 1 sort(s) chosen from the group which consists of a polyamic acid, polyamic acid ester, and a polyimide, Liquid crystal aligning agent. The method of claim 1,
The liquid crystal aligning agent whose sum total of the number of the carboxy group which the said compound (C) has, and the carboxy group produced|generated by heating is 2-6. The method of claim 1,
The liquid crystal aligning agent whose said compound (C) is a compound which is hard to vaporize in the temperature of 180 degrees C or less rather than the said solvent. The liquid crystal aligning film formed using the liquid crystal aligning agent in any one of Claims 1-5. A liquid crystal element provided with the liquid crystal aligning film of Claim 6. The manufacturing method of the liquid crystal aligning film which apply|coats the liquid crystal aligning agent in any one of Claims 1-5 on a board|substrate, and heats at the temperature of 180 degrees C or less.