KR20210125901A - Liquid crystal aligning agent, liquid crystal alignment film and manufacturing method thereof, and liquid crystal device - Google Patents

Abstract

An objective of the present invention is to provide a liquid crystal alignment agent for obtaining a liquid crystal element that exhibits a low pretilt angle even when a negative liquid crystal is used, rarely has an afterimage, has a high voltage retention rate, and has excellent reliability. A liquid crystal alignment agent contains a polymer [P] having a partial structure represented by Formula (1) in a main chain. In Formula (1), A^1 and A^2 are each independently a divalent nitrogen-containing aromatic heterocyclic group, and B^1 and B^2 are each independently a single-bond or divalent aromatic ring group. X^1 and X^2 are each independently -O- or -NR^1-(CH_2)_n-. R^1 is a hydrogen atom or a monovalent organic group, and n is an integer of 1 to 3. Y^1 is a divalent group that has at least one aromatic ring and coupled to each of X^1 and X^2 in a same aromatic ring or different aromatic rings. 「*」 indicates a dangling bond.

Description

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

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal element.

As a liquid crystal material of a liquid crystal element, a negative liquid crystal is used in a liquid crystal element such as a VA drive method or an MVA drive method, and a liquid crystal element such as a TN type, IPS (In-Plane Switching) drive method, FFS (Fringe Field Switching) drive method, etc. In this case, a positive liquid crystal is used. Moreover, in recent years, in order to achieve further high definition of a liquid crystal element, using a negative liquid crystal in the liquid crystal element of an IPS drive system or an FFS drive system is proposed (refer patent document 1).

BACKGROUND ART A liquid crystal element is applied to a wide range of devices and uses from a large-sized liquid crystal TV to a small-sized display device such as a smartphone. With the multipurpose use of such a liquid crystal element, further quality improvement of a liquid crystal element is calculated|required. For example, it may be calculated|required from the demand of a viewing angle characteristic that it is a pretilt angle (for example, pretilt angle of 1 degree or less) lower than before in a rubbing alignment film. In order to satisfy this request|requirement, the liquid crystal aligning film using the polyimide which has a specific structure is proposed (refer patent document 2).

International Publication No. 2016/152928 International Publication No. 2019/082975

As a result of the present inventors examining, when the liquid crystal display element using a negative liquid crystal was used over a long term, it turned out that seizure is easy to generate|occur|produce. Moreover, as a liquid crystal element, even when it uses over a long period of time, it is calculated|required that the voltage retention rate is high and it is excellent in reliability.

The present invention has been made in view of the above problems, and a liquid crystal aligning agent that exhibits a low pretilt angle even when a negative liquid crystal is used, is less likely to cause an afterimage, has a high voltage retention, and can provide a liquid crystal element with excellent reliability. Its main purpose is to provide

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to solve the said subject, and by using the polymer which has a specific structure in a principal chain, discovered that the said subject could be solved, and came to complete this invention. Specifically, the present invention provides the following means.

The liquid crystal aligning agent containing the polymer [P] which has in a principal chain the partial structure represented by <1> following formula (1).

(In formula (1), A ¹ and A ² are each independently a divalent nitrogen-containing aromatic heterocyclic group, and B ¹ and B ² are each independently a single bond or a divalent aromatic ring group. X ¹ and X ² are each independently -O- or -NR ¹ -(CH ₂ ) _n -. R ¹ is a hydrogen atom or a monovalent organic group, and n is an integer of ¹ to 3. Y 1 is one or more ^{It has an aromatic ring and is a divalent group bonded to each of X 1} and X ² in the same or different aromatic ring. "*" represents a bond.)

The manufacturing method of the liquid crystal aligning film including the process of forming a coating film using the liquid crystal aligning agent of <2> said <1>, and the process of providing liquid-crystal orientation ability by irradiating light to the said coating film.

The manufacturing method of the liquid crystal aligning film including the process of forming a coating film using the liquid crystal aligning agent of <3> said <1>, and the process of providing liquid-crystal orientation ability by rubbing the said coating film.

The liquid crystal aligning film formed using the liquid crystal aligning agent of <4> said <1>.

A liquid crystal element provided with the liquid crystal aligning film of <5> said <4>.

ADVANTAGE OF THE INVENTION According to the liquid crystal aligning agent of this invention, even when a negative liquid crystal is used, a low pretilt angle is shown, an afterimage is hard to generate|occur|produce, a voltage retention rate is high, and the liquid crystal element excellent in reliability can be obtained.

(Form for implementing the invention)

Below, each component contained in the liquid crystal aligning agent of this indication, and the other component mix|blended arbitrarily as needed are demonstrated.

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. The "chain hydrocarbon group" means a straight-chain hydrocarbon group and a branched hydrocarbon group composed of only a chain structure without a cyclic structure in the main chain. 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 does not need to be comprised only with the structure of an alicyclic hydrocarbon, and the thing which has a chain structure in part is 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.

An "aromatic ring" is a meaning including an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

"Structural unit" refers to a unit mainly constituting the main chain structure, and includes at least two or more units in the main chain structure.

<Polymer [P]>

The liquid crystal aligning agent of this indication contains the polymer [P] which has in a principal chain the partial structure (henceforth "specific structure") represented by following formula (1).

(In formula (1), A ¹ and A ² are each independently a divalent nitrogen-containing aromatic heterocyclic group, and B ¹ and B ² are each independently a single bond or a divalent aromatic ring group. X ¹ and X ² are each independently -O- or -NR ¹ -(CH ₂ ) _n -. R ¹ is a hydrogen atom or a monovalent organic group, and n is an integer of ¹ to 3. Y 1 is one or more ^{It has an aromatic ring and is a divalent group bonded to each of X 1} and X ² in the same or different aromatic ring. "*" represents a bond.)

In the formula (1), the ^{divalent nitrogen-containing aromatic heterocyclic group of A 1} and A ² is a residue obtained by removing two arbitrary hydrogen atoms bonded to atoms constituting the ring of the nitrogen-containing aromatic heterocyclic ring. Examples of the nitrogen-containing aromatic heterocycle constituting A ¹ and A ² include a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring and a pyrazine ring, and a substituent (eg For example, the heterocyclic ring etc. which have a methyl group, an ethyl group, etc. are mentioned. Among these, A ¹ and A ² are preferably a divalent group formed by removing two arbitrary hydrogen atoms bonded to carbon atoms constituting the pyridine ring, pyrimidine ring, pyridazine ring or pyrazine ring ring.

Examples of the divalent aromatic ring group for B ¹ and B ² include a divalent aromatic hydrocarbon group and a divalent aromatic heterocyclic group, and preferably a divalent aromatic hydrocarbon group or a divalent nitrogen-containing aromatic heterocyclic group. B ¹ and B ² may have a substituent in the aromatic ring moiety. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms and a halogen atom.

Specific examples of B ¹ and B ² include a divalent aromatic hydrocarbon group obtained by removing any hydrogen atom bonded to a carbon atom constituting a benzene ring, a naphthalene ring or an anthracene ring; Examples of the divalent nitrogen-containing aromatic heterocyclic group include groups obtained by removing two arbitrary hydrogen atoms bonded to carbon atoms constituting the pyridine ring, pyrimidine ring, pyridazine ring or pyrazine ring ring. A divalent aromatic hydrocarbon group is preferable and, as for the bivalent aromatic ring group of ^B<1> and B<^2> , from a viewpoint of aiming at densification of a liquid crystal aligning film, a phenylene group is more preferable.

Increase than the density of the liquid crystal alignment film, reduction of inhibition or residual image of increased ion density, that from the standpoint of achieving lower pretilt keratinocytes, B ¹ and B ² is at least one is preferably a single bond a and a single bond with more preferably.

With respect to ^{X 1} and X ² , the monovalent organic group of R ^{1 in "-NR 1} -(CH ₂ ) _n -" is preferably a monovalent hydrocarbon group or protecting group having 1 to 10 carbon atoms. When R ¹ is a monovalent hydrocarbon group, the monovalent hydrocarbon group is preferably an alkyl group or phenyl group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

When R ¹ is a protecting group, the protecting group is preferably a monovalent group that is released by heat, and examples thereof include a carbamate protecting group, an amide protecting group, an imide protecting group, and a sulfonamide protecting group. Among these, a carbamate-type protecting group is preferable from the viewpoint of high desorption property by heat, and specific examples thereof include a tert-butoxycarbonyl group, a benzyloxycarbonyl group, a 1,1-dimethyl-2-haloethyloxycarbonyl group, Allyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, etc. are mentioned. Among these, a tert-butoxycarbonyl group (Boc group) is particularly preferable from the viewpoint of excellent thermal detachability and the ability to reduce the residual amount in the film of the deprotected portion.

R ¹ is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a protecting group, and particularly preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a tert-butoxycarbonyl group.

From a viewpoint of making the improvement of the orientation regulating force of a liquid crystal aligning film, and low afterimage property compatible, as for n, 1 or 2 is preferable.

When X ¹ , X ² is "-NR ¹ -(CH ₂ ) _n -", from the point which can attain densification of a liquid crystal aligning film, and the point which can obtain a polymer with higher photoreactivity, X ¹ , X ^{As for 2} , it is preferable that a nitrogen atom (ie, "-NR ¹ -") is ^{bonded to B 1} , B ² , and it is more preferable that B ¹ , B ² is directly bonded to ^{A 1} , A ² as a single bond. do.

In that the photo-reactive than that to obtain a high polymer, X ¹ and X 1 with at least _{^{"-NR 1 - (CH 2) n}} - " of the ^two should preferably, X ¹ and X ² is ^"1 with -NR - and more preferably "- (CH _{2) n.}

Y ¹ is a divalent group having one or more aromatic rings and bonded to each of ^{X 1} and X ² in the same or different aromatic rings. Any of an aromatic hydrocarbon ring and an aromatic heterocyclic ring may be sufficient as the aromatic ring which Y<^{1> has.} The aromatic ring is preferably an aromatic hydrocarbon ring or a nitrogen-containing aromatic heterocycle, and specifically, it is preferably a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, a pyridazine ring or a pyrazine ring. In addition, when Y<^1> has two or more aromatic rings, those aromatic rings are mutually the same ring or a different ring. The aromatic ring which Y<^1> has may have a substituent in a ring part. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms and a halogen atom.

Y ¹ is preferably a divalent group represented by the following formula (2).

(In formula (2), B ³ and B ⁴ are each independently a divalent aromatic ring group, and X ³ is a single bond, -O- or -NR ¹ -(CH ₂ ) _n -. R ¹ and n are It has the same meaning as in the above formula (1), m is an integer of 0 to 3. When m is 2 or 3, a plurality of B ⁴ in the formula are the same group or different groups, and a plurality of X ³ are the same group or different groups It is a group. "*" indicates a bond.)

In the formula (2), as an example of the divalent aromatic ring group of ^{B 3} and B ⁴ , the description of the divalent aromatic ring group of ^{B 1} and B ^{2 is applied.} The description of R ¹ and n of ^{X 1} and X ^{2 above applies to R 1} and n in the _{case where} X ³ is “-NR ¹ -(CH ₂ ) n -”.

From a viewpoint of making the solubility with respect to the solvent of polymer [P] high, m becomes like this. Preferably it is 0-2, More preferably, it is 0 or 1.

As a preferable specific example of Y<^1> , group represented by each of a following formula (Y-1) - a formula (Y-15) is mentioned.

(In formulas (Y-1) to (Y-15), "Boc" is a tert-butoxycarbonyl group. "*" represents a bond.)

As a preferable specific example of a specific structure, the structure represented by each of following formula (1-1) - Formula (1-21) is mentioned.

(In formulas (1-14) to (1-19), R ¹¹ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a tert-butoxycarbonyl group. “*” represents a bond.)

The specific structure is, in Formulas (1-1) to (1-21), each of Formulas (1-1) to (1-11) and (1-14) to (1-18) A structure represented by , is particularly preferred.

The main chain of the polymer [P] is not particularly limited as long as a specific structure can be introduced into the main chain. From the viewpoint of easy introduction of the polymer [P] into the main chain, the polymer [P] is preferably a polymer containing a structural unit derived from a monomer having a specific structure, and a diamine compound having a specific structure (hereinafter “specific diamine”). It is more preferable that it is a polymer containing the structural unit derived from ). Among these, the polymer [P] is at least selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, from the viewpoint of forming a liquid crystal aligning film with high affinity and mechanical strength with a liquid crystal and high reliability. It is preferable to include 1 type.

Here, the "main chain" means the part of the "stem" which consists of the chain of the longest atom in a polymer. In addition, it is permissible for the part of this "stem" to contain a ring structure. That is, "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. A "side chain" means the part branched from the "stem" of a polymer.

In the polymer [P], the content of the structural unit derived from the monomer having a specific structure is preferably 5 mol% or more, more preferably 10 mol% or more, with respect to the total amount of the monomer units in the polymer [P]. It is preferable, and it is more preferable that it is 20 mol% or more, and it is still more preferable that it is 30 mol% or more.

It is preferable that the specific diamine used for the synthesis|combination of a polymer [P] is a compound represented by following formula (3).

(In formula (3), B ⁵ and B ⁶ are each independently a single bond or a divalent aromatic ring group. However, when B ¹ is a divalent aromatic ring group, B ⁵ is a single bond and B ² is a divalent aromatic ring group. In the case of an aromatic ring group, B ⁶ is a single bond. A ¹ , A ² , B ¹ , B ² , X ¹ , X ² and Y ¹ have the same meaning as in Formula (1) above.)

In the formula (3), to the examples and preferred examples of the divalent aromatic ring groups of ^{B 5} and B ⁶ , the description of the divalent aromatic ring groups of ^{B 1} and B ^{2 above applies.} From the viewpoint of promoting the densification of the liquid crystal alignment film, B ⁵ and B ⁶ is a single bond or the divalent aromatic hydrocarbon groups are preferred, a single bond or the phenylene group and more preferably, particularly preferably a single bond is.

To ^{the examples and preferred examples of A 1} , A ² , B ¹ , B ² , X ¹ , X ^{2 ,} and Y ¹ , the description of the formula (1) applies.

As a preferable example of specific diamine, the compound etc. which are represented by each of following formula (3-1) - Formula (3-25) are mentioned.

(In formulas (3-14) to (3-19), R ¹¹ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a tert-butoxycarbonyl group.)

As for specific diamine, the compound represented by each of said Formula (3-1) - Formula (3-11) and Formula (3-14) - Formula (3-18) among the above is preferable. In addition, as specific diamine, you may use individually by 1 type, and may use it in combination of 2 or more type.

(polyamic acid)

When the polymer [P] is a polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid [P]") can be obtained by reacting tetracarboxylic dianhydride with a diamine compound containing a specific diamine.

(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. Specific examples thereof include 1,2,3,4-butanetetracarboxylic dianhydride, ethylenediamine tetraacetic acid dianhydride, and the like as aliphatic tetracarboxylic dianhydride; As alicyclic tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic 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, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2anhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride My back; As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-carbonyldiphthalic anhydride, etc. second; In addition to those mentioned respectively, the tetracarboxylic dianhydride of Unexamined-Japanese-Patent No. 2010-97188 can be used. As tetracarboxylic dianhydride, 1 type can be used individually or in combination of 2 or more types.

The tetracarboxylic dianhydride used for the synthesis|combination of polyamic acid [P] has high solubility with respect to a solvent, and since the liquid crystal aligning film which shows favorable electrical properties and low residual image characteristic can be obtained, aliphatic tetracarboxylic dianhydride and alicyclic It is preferable to contain the at least 1 sort(s) of compound chosen from the group which consists of formula tetracarboxylic dianhydride, and it is more preferable to contain alicyclic tetracarboxylic dianhydride. The use ratio of the alicyclic tetracarboxylic dianhydride is preferably 20 mol% or more, more preferably 40 mol% or more, based on the total amount of tetracarboxylic dianhydride used for the synthesis of polyamic acid [P], It is more preferable that it is 50 mol% or more.

(diamine compound)

Although only specific diamine may be sufficient as the diamine compound used for the synthesis|combination of polyamic acid [P], you may use the diamine (henceforth "other diamine") different from a specific diamine with a specific diamine. Examples of other diamines include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane.

Specific examples of other diamines include metaxylylenediamine, hexamethylenediamine, and the like as aliphatic diamines; Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and the like; As aromatic diamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 1 ,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,6-bis(4-amino) Phenoxy) hexane, bis [2- (4-aminophenyl) ethyl] hexane diacid, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane , 2,2-bis (4-aminophenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4 '-diaminodiphenylamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-(phenylenediisopropylidene)bisaniline, 2,6-diaminopyridine, 2, main chain diamines such as 4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole and 3,6-diaminoacridine; Hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, chole Steryloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholestanyl, 3 ,5-diaminobenzoic acid cholesteryl, 3,5-diaminobenzoic acid lanostanyl, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane , 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid = 5ξ-cholestan-3-yl, 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) represents a hand), 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, a is 0 or 1, b is an integer of 0 to 2 , c is an integer from 1 to 20, and d is 0 or 1. However, a and b do not become 0 at the same time.)

side-chain diamines such as compounds represented by

Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like. As a compound represented by said Formula (E-1), the compound etc. which are represented by each of following formula (E-1-1) - Formula (E-1-4) are mentioned, for example.

Synthesis of polyamic acid [P] WHEREIN: From a viewpoint of obtaining the liquid crystal element which expresses a low pretilt angle, is hard to produce an afterimage, and shows high VHR and high reliability, the use ratio of a specific diamine polyamic acid [P] It is preferable that it is 20 mol% or more with respect to the total amount of the diamine compound used for the synthesis|combination of this, It is more preferable that it is 30 mol% or more, It is still more preferable that it is 50 mol% or more. In addition, as other diamine, 1 type can be used individually or in combination of 2 or more type.

(Synthesis of polyamic acid)

Polyamic acid [P] can be obtained by making tetracarboxylic dianhydride and a diamine compound react with a molecular weight modifier as needed. In the synthesis reaction of polyamic acid [P], the use ratio of tetracarboxylic dianhydride and the diamine compound is a ratio in which the acid anhydride group of tetracarboxylic dianhydride is 0.2 to 2 equivalents with respect to 1 equivalent of the amino group of the diamine compound. This is preferable. Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate, etc. can be heard It is preferable that the usage ratio of a molecular weight modifier shall be 20 mass parts or less with respect to a total of 100 mass parts of tetracarboxylic dianhydride and diamine compound to be used.

The synthesis reaction of 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 an aprotic polar solvent, a phenol solvent, an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, a halogenated hydrocarbon, and a hydrocarbon. Specific examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, and hexamethylphosphotria. At least one selected from the group consisting of mide, m-cresol, xylenol and halogenated phenol is used as the reaction solvent, or at least one of these and another organic solvent (eg, butylcellosolve, diethylene It is preferable to use a mixture with glycoldiethyl ether, etc.). It is preferable that the usage-amount (a) of an organic solvent sets it as the quantity used as 0.1-50 mass % with respect to the total amount (b) of tetracarboxylic dianhydride and diamine with respect to the total amount (a+b) of a reaction solution.

As described above, a polymer solution obtained by dissolving polyamic acid [P] is obtained. You may use this polymer solution for preparation of a liquid crystal aligning agent as it is, and after isolating polyamic acid [P] contained in a polymer solution, you may provide for preparation of a liquid crystal aligning agent.

<Polyamic acid ester>

When the polymer [P] is a polyamic acid ester, the polyamic acid ester (hereinafter also referred to as “polyamic acid ester [P]”) is, for example, [I] a method of reacting polyamic acid [P] with an esterifying agent; [II] a method of reacting a tetracarboxylic acid diester with a diamine compound containing a specific diamine, [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound containing a specific diamine, etc. can The polyamic acid ester [P] may have only a dark acid ester structure, or may be a partial esterified product in which a dark acid structure and a dark acid ester structure coexist. The reaction solution formed by dissolving polyamic acid ester [P] may be used for preparation of a liquid crystal aligning agent as it is, and after isolating polyamic acid ester [P] contained in a reaction solution, you may provide for preparation of a liquid crystal aligning agent.

<Polyimide>

When the polymer [P] is a polyimide, the polyimide (hereinafter also referred to as “polyimide [P]”) can be obtained, for example, by imidizing the polyamic acid [P] synthesized as described above by dehydration ring closure. have. The polyimide [P] may be a complete imidized product in which the entire amic acid structure of polyamic acid [P], which is its precursor, has been cyclized by dehydration, or only a part of the amic acid structure is cyclized by dehydration so that the amic acid structure and the imide ring structure coexist. Partial imide storage is fine. It is preferable that the imidation ratio is 20 to 99 %, and, as for polyimide [P], it is more preferable that it is 30 to 90 %. In addition, the imidation ratio represents 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 in percentage. Here, an isoimide ring may be sufficient as a part of an imide ring.

The dehydration ring closure of the polyamic acid [P] is preferably carried out 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. In this method, 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. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid [P]. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours. Moreover, the reaction solution containing polyimide [P] may be used for preparation of a liquid crystal aligning agent as it is, and after isolating polyimide [P], you may provide for preparation of a liquid crystal aligning agent.

When the solution viscosity of the polymer [P] used for preparation of a liquid crystal aligning agent is set as the solution with a density|concentration of 10 mass %, it is preferable to have a solution viscosity of 10-800 mPa*s, and the solution viscosity of 15-500 mPa*s It is more preferable to have In addition, the solution viscosity (mPa·s) is a polymer solution having a concentration of 10% by mass prepared using a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) of the polymer [P]. It is the value measured in 25 degreeC using the 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 2,000 to 300,000. Moreover, the molecular weight distribution (Mw/Mn) represented by ratio of Mw and the number average molecular weight (Mn) of polystyrene conversion measured by GPC becomes like this. Preferably it is 7 or less, More preferably, it is 5 or less. Moreover, preparation of a liquid crystal aligning agent WHEREIN: Polymer [P] may be used individually by 1 type, and may be used in combination of 2 or more type.

<Other ingredients>

A liquid crystal aligning agent may contain the component (it is also called "other components" hereafter) different from a polymer [P] as needed other than a polymer [P].

(Other polymers)

The liquid crystal aligning agent of this indication may contain the polymer (henceforth "other polymer") which does not have a specific structure as a polymer component. The main skeleton of the other polymer is not particularly limited. Examples of other polymers include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole. , a cellulose derivative, polyacetal, a (meth)acrylic polymer, a styrene polymer, a maleimide polymer, or a styrene-maleimide polymer. When used in combination with the polymer [P], the affinity with the liquid crystal is high and the other polymer is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide from the viewpoint of increasing the reliability of the liquid crystal element. Paper is preferred.

When making a liquid crystal aligning agent contain another polymer, 5 mass % or more is preferable with respect to the total amount of polymer [P] and another polymer, and, as for the content rate of polymer [P], 10 mass % or more is more preferable and 20 mass % or more is more preferable, and 30 mass % or more is still more preferable. As another polymer, 1 type can be used individually or in combination of 2 or more type.

(solvent)

The liquid crystal aligning agent of this indication is prepared as a liquid composition in which a polymer [P] and the other component used as needed preferably disperse|distribute or melt|dissolve in a suitable solvent.

As the solvent, an organic solvent is preferably used. Specific examples thereof include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, Phenol, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, 1- Hexanol, 2-hexanol, propane-1,2-diol, 3-methoxy-1-butanol, ethylene glycol monomethyl ether, methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, aceto Methyl acetate, ethyl acetoacetate, ethyl propionate, 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, propylene glycol monomethyl Ether (PGME), diethylene glycol diethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol diacetate, cyclopentanone, cyclohexanone, etc. are mentioned. These are used individually by 1 type or in mixture of 2 or more types.

As another component contained in a liquid crystal aligning agent, antioxidant, a metal chelate compound, hardening accelerator, surfactant, a filler, a dispersing agent, a photosensitizer, etc. are mentioned other than the above, for example. The blending ratio of other components can be appropriately selected according to each compound within a range that does not impair the effects of the present invention.

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 %. The film thickness of a coating film can fully be ensured that solid content concentration is 1 mass % or more, and the liquid crystal aligning film which shows favorable liquid-crystal orientation is easy to be obtained. On the other hand, if solid content concentration is 10 mass % or less, a coating film can be made into suitable thickness, and the liquid crystal aligning film which shows favorable liquid-crystal orientation is easy to be obtained, and also the viscosity of a liquid crystal aligning agent becomes moderate, and applicability|paintability can be made favorable. tends to be

«Liquid crystal alignment film and liquid crystal element»

The liquid crystal aligning film of this indication is manufactured 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 driving method of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type ( It can be applied to various modes such as Optically Compensated Bend) type and PSA (Polymer Sustained Alignment) type. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. 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 plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin) can be used. As a transparent conductive film formed on one surface of the substrate, an NESA film (registered trademark of PPG Corporation in the United States) made of _{tin oxide (SnO 2 ), an ITO film made of indium oxide-tin oxide (In 2} O ₃ -SnO ₂ ), etc. are used. can When manufacturing a TN-type, STN-type, or VA-type liquid crystal element, two substrates on which a patterned transparent conductive film is formed are used. On the other hand, when manufacturing an IPS-type or FFS-type liquid crystal element, the board|substrate in which the electrode patterned in the comb-tooth shape is formed, and the counter board|substrate in which the electrode is not formed are used.

The coating method of the liquid crystal aligning agent to a board|substrate is not specifically limited, For example, a spin coating method, a printing method (for example, an offset printing method, a flexographic printing method, etc.), an inkjet method, a slit coating method, a bar coater method , an extrusion die method, a direct gravure coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, or the like.

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. Pre-baking temperature becomes like this. Preferably it is 30-200 degreeC, and pre-baking 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 baking temperature (post-baking temperature) at this time becomes like this. Preferably it is 80-280 degreeC, More preferably, it is 80-250 degreeC. Post-baking time becomes like this. Preferably it is 5 to 200 minutes. The film thickness of the film to be formed is preferably 0.001 to 1 µm.

<Step 2: Orientation treatment>

When manufacturing the liquid crystal element of a TN type, STN type, IPS type, or FFS type, the process (orientation treatment) which provides liquid-crystal orientation ability is performed with respect to the coating film formed in the said process 1. 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 the said coating film.

Light irradiation for photo-alignment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film before the post-baking process in the pre-baking process, the pre-baking process and the post-baking process in at least one of the coating film It can carry out by the method of irradiating with respect to a coating film during heating, etc. As radiation irradiated to the coating film, for example, ultraviolet rays and visible rays containing light having a wavelength of 150 to 800 nm can be used. Preferably, it is an ultraviolet-ray containing light of a wavelength of 200-400 nm. When the radiation is polarized light, linearly polarized light or partially polarized light may be sufficient. When the radiation 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. In the case of unpolarized radiation, the irradiation direction 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. are mentioned, for example. The radiation dose is preferably 200 to 30,000 J/m 2 , and more preferably 500 to 10,000 J/m 2 . After light irradiation for imparting orientation ability, the substrate surface is treated with, for example, water or an organic solvent (eg, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) Alternatively, a process for washing using a mixture thereof or a process for heating the substrate may be performed.

<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, two board|substrates are opposingly arrange|positioned through a gap|interval so that a liquid crystal aligning film may oppose, the peripheral part of two board|substrates is joined with a sealing compound, The cell enclosed by the board|substrate surface and a sealing compound. A method of sealing an injection hole by injecting and filling a liquid crystal in a gap, a method by an ODF method, etc. are mentioned. 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 liquid crystal, although either a positive type and a negative type may be used, Preferably it is a negative type. As a negative liquid crystal, Merck company "MLC-6608", "MLC-6609", "MLC-6610", "MLC-7026-100" etc. are mentioned, for example. In particular, when a negative liquid crystal is used in an IPS type and FFS type liquid crystal element, it is preferable at the point that the transmission loss in an electrode upper part can be made small and the contrast improvement can be aimed at. Moreover, as a liquid crystal, a nematic liquid crystal and a smectic liquid crystal are mentioned, Among these, a nematic liquid crystal is preferable.

When manufacturing a liquid crystal display device, a polarizing plate is joined to the outer surface of a liquid crystal cell successively, and a liquid crystal display element is obtained. 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.

In addition, by forming a liquid crystal aligning film using the polymer [P], even when a negative liquid crystal is used, a low pretilt angle is exhibited, an afterimage hardly occurs, a voltage retention rate is high, and a liquid crystal element excellent in reliability can be obtained. is not clear, but the following are conceivable. The polymer [P] has a nitrogen-containing aromatic heterocyclic structure in the main chain, and an aromatic ^{ring bonded to -O- or -NR 1} -(CH ₂ ) _n - at a specific position (formula (1) above) Reference). Thereby, the liquid crystal aligning film is densified by the intermolecular interaction of polymers, the ionic impurity generated by long-term use is fixed to the film|membrane, the increase in ion density is suppressed, and favorable low pretilt angle characteristic and low afterimage characteristics are considered.

The liquid crystal element of the present invention can be effectively applied to various uses. Specifically, 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 smartphone, various display devices such as various monitors, liquid crystal TVs, information displays, etc. , a dimming device, retardation film, and the like.

(Example)

Hereinafter, although embodiment is described in more detail based on an Example, this invention is not interpreted limitedly by a following Example.

In the following examples, the weight average molecular weight (Mw) of the polymer, the imidation ratio of the polyimide in the polymer solution, the solution viscosity of the polymer solution, and the epoxy equivalent were measured by the following methods. The required amounts of the raw material compound and the polymer used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as needed.

[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: N,N-dimethylformamide solution containing lithium bromide and phosphoric acid

Temperature: 40℃

Pressure: 68kgf/cm2

[Imidation rate of polyimide]

The polyimide solution was poured into pure water, and the resulting 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, 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 protons of the NH group appearing in the vicinity of 10 ppm of the chemical shift, A ² is the peak area derived from other protons, and α is the polymer precursor (polyamic acid) It is the ratio of the number of other protons to one proton of the NH group.)

[Solution Viscosity of Polymer Solution]

The solution viscosity (mPa*s) of the polymer solution was measured at 25 degreeC using the E-type rotational viscometer about the solution which prepared the polymer density|concentration to 10 mass % using the predetermined|prescribed solvent.

[epoxy equivalent]

Epoxy equivalent is a value measured according to the hydrochloric acid-methylethylketone method of JIS C2105.

The abbreviation of a compound is as follows. In addition, below, the compound represented by Formula (X) may be simply represented by "compound (X)".

<Synthesis of polymer>

1. Synthesis of polyamic acid

[Synthesis Example 1]

100 parts by mole of 1,3-dimethylcyclobutane-1,2:3,4-tetracarboxylic dianhydride as tetracarboxylic dianhydride, and 100 parts by mole of compound (DA-1) as a diamine compound N-methyl-2-pyrroly It melt|dissolved in Don (NMP), it reacted at room temperature for 6 hours, and obtained the solution containing 15 mass % of polyamic acids (let this be "polymer (PA-1)").

[Synthesis Examples 2 to 12]

The same operation as in Synthesis Example 1 was performed except that the types and amounts of tetracarboxylic dianhydride and diamine compounds used were changed as shown in Table 1 below, and polyamic acids (polymers (PA-2) to (PA-7) ), (PB-1) to (PB-5)) were obtained.

2. Synthesis of polyimide

[Synthesis Example 13]

100 mol parts of 1,3-dimethylcyclobutane-1,2:3,4-tetracarboxylic dianhydride as tetracarboxylic dianhydride and 100 mol parts of compound (DA-1) as a diamine compound were dissolved in NMP, and at room temperature 6 Time reaction was performed and the solution containing 15 mass % of polyamic acids was obtained. Next, NMP was added to the obtained polyamic acid solution, it was set as the solution with a polyamic acid concentration of 10 mass %, pyridine and acetic anhydride were added, and dehydration ring closure reaction was performed at 60 degreeC for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with a new NMP to obtain a solution containing 15% by mass of a polyimide having an imidation ratio of about 70% (this is referred to as a "polymer (PI-1)").

[Synthesis Examples 14 to 16]

The same operation as in Synthesis Example 13 was performed except that the types and amounts of tetracarboxylic dianhydride and diamine compounds used were changed as shown in Table 1 below, and polyimides (polymers (PI-2) to (PI-4) )) was obtained.

[Example 1]

1. Preparation of liquid crystal aligning agent

The solution of the polymer (PA-1) obtained in Synthesis Example 1 was diluted with NMP and butyl cellosolve (BC), the solvent composition was NMP/BC=80/20 (mass ratio), and the solid content concentration was 3.5 mass. % solution. 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. Preparation of FFS-type liquid crystal cell using rubbing method

A glass substrate (referred to as a first substrate) in which a flat electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) are laminated on one side in this order, and a glass substrate without an electrode (referred to as a second substrate) ) was prepared. Next, the liquid crystal aligning agent (AL-1) was apply|coated to each of the single side|surface of the electrode formation surface of a 1st board|substrate, and a 2nd board|substrate using a spinner, and it heated (pre-baked) for 3 minutes with a 110 degreeC hotplate. . Then, drying (post-baking) was performed for 30 minutes in the 230 degreeC oven which substituted the inside of the furnace with nitrogen, and the coating film with an average film thickness of 0.08 micrometer was formed. Next, the coating film surface was rubbed with a rubbing machine having a roll wound with rayon cloth at a roll rotation speed of 1000 rpm, a stage movement speed of 3 cm/sec, and a bushy foot press-in length of 0.3 mm. Then, the pair of board|substrates which have a liquid crystal aligning film were obtained by performing ultrasonic cleaning for 1 minute in ultrapure water, and drying for 10 minutes in 100 degreeC clean oven then.

Next, with respect to a pair of board|substrates which have a liquid crystal aligning film, the epoxy resin adhesive which left the liquid crystal injection hole in the edge of the surface on which the liquid crystal aligning film was formed, and put the aluminum oxide sphere of diameter 3.5 micrometers was screen-printed and apply|coated. Then, the board|substrates were overlapped and pressed, and the adhesive agent was thermosetted at 150 degreeC over 1 hour. Next, in the liquid crystal injection port, after filling the gap between a pair of board|substrates with negative liquid crystal (Merck Corporation make, MLC-6608), the liquid crystal injection port was sealed with the epoxy adhesive. Moreover, in order to remove the flow orientation at the time of liquid crystal injection, after heating this at 120 degreeC, it cooled slowly to room temperature, and the liquid crystal cell was manufactured. In addition, when overlapping a pair of board|substrates, it was made so that the rubbing method of each board|substrate became antiparallel. As the top electrode, a comb-tooth electrode having a shape in which a plurality of parallel linear electrodes were bent in a “<” shape at the center part, and having an electrode line width of 3 µm and a distance between the electrodes of 6 µm was used (Unexamined Japanese Publication) 3 of Patent Publication No. 2014-77845). The obtained liquid crystal cell has two pixel areas (1st area|region, 2nd area|region) from which the orientation direction of a liquid crystal differs with the bent part of a linear electrode as a boundary, and multi-domain drive is possible.

3. Evaluation of low pre-tilt angle characteristics

Regarding the liquid crystal cell manufactured in 2. above, non-patent literature "T.J.Scheffer et. al.J.Appl.Phys.vo.19, p.2013 (1980)", measuring the value of the inclination angle of liquid crystal molecules from the substrate surface by the crystal rotation method using He-Ne laser light And this was made into a pretilt angle. When the measured value of the pretilt angle is less than 0.7 degrees, "Good (◎)", when it is 0.7 degrees or more and less than 0.9 degrees, "Good (○)", when it is 0.9 degrees or more and less than 1.1 degrees, "Possible (Δ)", 1.1 It was set as "impossible (x)" when it was more than degree|times. As a result, evaluation of the low pre-tilt angle characteristic of this Example was "excellent".

4. Evaluation of Low Afterimage Characteristics

Between the electrodes of the FFS type|mold liquid crystal cell manufactured by said 2., the alternating-current voltage 10V was applied in the constant temperature environment of 60 degreeC for 72 hours. Then, it was set as the state which short-circuited between the top electrode and the bottom electrode of a liquid crystal cell, and it was left to stand at room temperature as it is for 1 day. After standing for one day, the liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, the backlight is turned on in a state where no voltage is applied, and the arrangement angle of the liquid crystal cell is adjusted so that the luminance of the transmitted light is the smallest. did. The rotation angle at the time of rotating a liquid crystal cell from the angle at which one area|region becomes the darkest among two pixel areas of an FFS-type liquid crystal cell to the angle at which the other area|region becomes darkest was made into angle (DELTA)θ. It can be said that an afterimage is difficult to generate|occur|produce, so that the angle Δθ is small, and the low afterimage characteristic is good. When the angle Δθ is less than 0.10 degrees, "Good (◎)", when it is 0.10 or more and less than 0.15, "Good (○)", when it is 0.15 or more and less than 0.20, "Possible (Δ)", when it is 0.20 or more It evaluated as "impossible (x)". As a result, the low afterimage characteristic of this Example was evaluation of "excellence".

5. Evaluation of electrical properties

After leaving the liquid crystal cell manufactured in said 2. to 60 degreeC oven, the voltage retention (this is also called "initial stage VHR") was measured on the conditions of 1V and 1670 msec using the Toyo Technicer VHR measuring apparatus. As evaluation criteria, when the initial VHR is 80% or more, "good (◎)"; In the case of less than %, it was set as "impossible (x)". As a result, the evaluation of the initial VHR of this Example was "good".

6. Evaluation of reliability after light irradiation

Reliability of the liquid crystal cell manufactured in said 2. was evaluated. Evaluation was performed as follows. First, after applying the voltage of 1V to a liquid crystal cell for 60 microseconds, the voltage retention ratio (VHR1) 1670 milliseconds after application cancellation|release was measured. Then, after irradiating CCFL (backlight) to a liquid crystal cell at 60 degreeC for 1 week, it left still in room temperature and it cooled naturally to room temperature. After cooling, after applying a voltage of 1 V to the liquid crystal cell for 60 microseconds, the voltage retention ratio (VHR2) 1670 milliseconds after application cancellation was measured. In addition, "VHR-1" manufactured by Toyo Technica Co., Ltd. was used as a measuring apparatus. The rate of change of VHR (?VHR) at this time was calculated from the difference between VHR1 and VHR2 (?VHR=VHR1-VHR2), and reliability was evaluated by ?VHR. When the ΔVHR is less than 10%, “Good (◎)”, when it is 10% or more and less than 15%, “Good (○)”, when it is 15% or more and less than 20%, “Possible (Δ)”, and when it is 20% or more, “ Impossible (x)". As a result, in this Example, reliability was "good".

[Examples 2 to 11 and Comparative Examples 1 to 4]

Except having changed the composition of a liquid crystal aligning agent like following Table 2, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent. Moreover, using the obtained liquid crystal aligning agent, it carried out similarly to Example 1, the FFS-type liquid crystal cell was manufactured by the rubbing method, and various evaluation was performed. Their results are shown in Table 2 below. In addition, in Examples 10 and 11, two types of polymers were used as a polymer component. In Table 2, the numerical value in parentheses of the polymer component column shows the compounding ratio (mass part) in solid content of each polymer with respect to the whole quantity of the polymer component used for preparation of a liquid crystal aligning agent.

As shown in Table 2, Examples 1-11 were able to take the balance of the various characteristics of a low pretilt angle characteristic, a low afterimage characteristic, initial stage VHR, and reliability compared with Comparative Examples 1-4. In particular, in Examples 1-5 and 7-11, any characteristic was excellent in evaluation of "double-circle" or "(circle)". Among these, in Examples 1, 4, and 5, the low pretilt angle characteristic was "double-circle", and the low afterimage characteristic was also favorable.

[Example 12]

1. Preparation of liquid crystal aligning agent

The solution of the polymer (PA-4) obtained in Synthesis Example 4 was diluted with NMP and BC, and the solvent composition was NMP/BC=80/20 (mass ratio) and the solid content concentration was 3.5% by mass. A liquid crystal aligning agent (AL-12) was prepared by filtering this solution with the filter with a hole diameter of 0.2 micrometer.

2. Manufacture of FFS-type liquid crystal display device using photo-alignment method

The 1st board|substrate and 2nd board|substrate similar to Example 1 were prepared. Next, a liquid crystal aligning agent (AL-12) is apply|coated to each of the electrode formation surface of a 1st board|substrate, and one board|substrate surface of a 2nd board|substrate using a spinner, and it heats for 1 minute on an 80 degreeC hotplate (free). baked). Then, drying (post-baking) was performed for 30 minutes in 230 degreeC oven which substituted the inside of furnace with nitrogen, and the coating film with an average film thickness of 0.1 micrometer was formed. The obtained coating film was subjected to photo-alignment treatment by irradiating 1,000 J/m 2 of ultraviolet rays containing a linearly polarized 254 nm bright line from the substrate normal direction using an Hg-Xe lamp. In addition, this irradiation amount is the value measured using the photometer measured with wavelength 254nm reference|standard. Next, the coating film to which the photo-alignment process was given was heat-processed by heating in 230 degreeC clean oven for 30 minutes, and the liquid crystal aligning film was formed.

Next, with respect to one board|substrate among a pair of board|substrates in which the liquid crystal aligning film was formed, the epoxy resin adhesive agent with a 3.5-micrometer-diameter aluminum oxide sphere was apply|coated by screen printing to the outer edge of the surface which has a liquid crystal aligning film. Thereafter, the substrates were laminated and pressed so that the projection direction of the polarization axis to the substrate surface at the time of light irradiation was antiparallel, and the adhesive was thermosetted at 150°C for 1 hour. Next, after filling a negative liquid crystal (Merck Corporation make, MLC-6608) between a pair of board|substrates at the liquid crystal injection port, the liquid crystal injection port was sealed with the epoxy adhesive, and the liquid crystal cell was obtained. Moreover, in order to remove the flow orientation at the time of liquid crystal injection, after heating this at 120 degreeC, it cooled slowly to room temperature. Then, the polarizing plate was bonded together on the outer both surfaces of the board|substrate in a liquid crystal cell, and the liquid crystal display element was obtained. In addition, by carrying out the above series of operations by changing the ultraviolet irradiation amount after post-baking in the range of 100 to 10,000 J/m 2 , three or more liquid crystal display elements with different ultraviolet irradiation amounts were manufactured, and exhibiting the best alignment characteristics The liquid crystal display element of the exposure amount (optimum exposure amount) was used for evaluation of the following liquid-crystal orientation, a low afterimage characteristic, an electrical characteristic, and reliability.

3. Evaluation of photoreactivity

On a quartz substrate, the liquid crystal aligning agent (AL-12) prepared in 1. above was applied with a spinner, heated on a hot plate at 80° C. for 1 minute, and then in an oven at 230° C. in which the inside of the furnace was substituted with nitrogen for 30 minutes. It dried and formed the coating film with an average film thickness of 0.1 micrometer. The surface of the coating film was irradiated with an ultraviolet light of 1,000 J/m 2 including a linearly polarized 254 nm bright line from the substrate normal direction using an Hg-Xe lamp. Then, the photoreactivity was evaluated from the absorption derived from the substituted maleimide compound which generate|occur|produces by photolysis. Specifically, the absorbance of the coating film after light irradiation at the maximum absorption wavelength in the region of 220 to 250 nm was measured, and the rate of increase with respect to the absorbance of the coating film before light irradiation at the wavelength was calculated. When the absorbance increase rate is 20% or more, "Good (◎)", when the absorbance increase rate is 10% or more and less than 20%, "Good (○)", when the absorbance increase rate is less than 10% "Impossible (x)" did it with As a result, the evaluation of this Example was "excellent".

4. Evaluation of liquid crystal orientation

About the liquid crystal display element manufactured in said 2., the presence or absence of an abnormal domain was observed with the microscope (50 times magnification) by the change of the contrast when the voltage was turned on/off (applied/released), and liquid crystal orientation was evaluated. . At this time, the case where an abnormal domain was not observed was made into "good (circle)", and the case where an abnormal domain was observed was made into "impossible (x)". As a result, in this Example, it was judged as liquid-crystal orientation "good|favorableness".

5. Evaluation of low afterimage characteristics

Except that the polarizing plate was not bonded to the outer both surfaces of the board|substrate, operation similar to said 2. was performed, the FFS-type liquid crystal cell was produced, and the method similar to Example 1 evaluated the low afterimage characteristic. As a result, in this Example, the low afterimage characteristic was judged to be "excellent".

6. Evaluation of electrical properties

About the liquid crystal display element manufactured in said 2., the method similar to Example 1 evaluated the electrical characteristic. As a result, in this Example, the electrical characteristics were judged to be "excellent".

7. Assessment of Reliability

About the liquid crystal display element manufactured in said 2., the method similar to Example 1 evaluated reliability. As a result, in this Example, reliability was judged to be "good".

[Examples 13 to 16 and Comparative Examples 5 and 6]

Except having changed the composition of a liquid crystal aligning agent like following Table 3, it carried out similarly to Example 12, and prepared the liquid crystal aligning agent. Moreover, using the obtained liquid crystal aligning agent, it carried out similarly to Example 12, the FFS-type liquid crystal display element was manufactured by the photo-alignment method, and various evaluation was performed. Their results are shown in Table 3 below. In addition, in Examples 15 and 16, two types of polymers were used as a polymer component. In Table 3, the numerical value in parentheses of the polymer component column shows the compounding ratio (mass part) in solid content of each polymer with respect to the whole quantity of the polymer component used for preparation of a liquid crystal aligning agent. Since photoreactivity was not evaluated for Examples 15 and 16, "-" was indicated in the column of photoreactivity.

As shown in Table 3, Examples 12-16 were able to balance the liquid-crystal orientation, a low afterimage characteristic, initial stage VHR, and various characteristics of reliability compared with Comparative Examples 5 and 6. Moreover, the liquid crystal aligning agent of Examples 12-14 was excellent also in photoreactivity.

Claims (9)

The liquid crystal aligning agent containing the polymer [P] which has in a principal chain the partial structure represented by following formula (1).

(In formula (1), A ¹ and A ² are each independently a divalent nitrogen-containing aromatic heterocyclic group, B ¹ and B ² are each independently a single bond or a divalent aromatic ring group; X ¹ and X ² are each independently -O- or -NR ¹ -(CH ₂ ) _n -; R ¹ is a hydrogen atom or a monovalent organic group, n is an integer of 1 to 3; Y ¹ is in one or more directions It has a ring and is a ^{divalent group bonded to each of X 1} and X ² in the same or different aromatic ring; "*" represents a bond) According to claim 1,
Said Y<^1> is divalent group represented by following formula (2), Liquid crystal aligning agent.

(In formula (2), B ³ and B ⁴ are each independently a divalent aromatic ring group, X ³ is a single bond, -O- or -NR ¹ -(CH ₂ ) _n -; R ¹ and n are It has the same meaning as in the above formula (1); m is an integer of 0 to 3; when m is 2 or 3, a plurality of B ⁴ in the formula are the same group or different groups, and a plurality of X ³ are the same group or different groups group; "*" indicates a bond) According to claim 1,
The said polymer [P] has a structural unit derived from the diamine compound represented by following formula (3), The liquid crystal aligning agent.

(In formula (3), B ⁵ and B ⁶ are each independently a single bond or a divalent aromatic ring group; provided that, when B ¹ is a divalent aromatic ring group, B ⁵ is a single bond and B ² is a divalent In the case of an aromatic ring group, B ⁶ is a single bond; A ¹ , A ² , B ¹ , B ² , X ¹ , X ² and Y ¹ have the same meaning as in Formula (1) above) According to claim 1,
The said polymer [P] is at least 1 sort(s) chosen from the group which consists of polyamic acid, polyamic acid ester, and a polyimide, The liquid crystal aligning agent. According to claim 1,
The polymer [P] is a polymer having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine compound,
The liquid crystal aligning agent in which the said tetracarboxylic acid derivative contains alicyclic tetracarboxylic dianhydride. The manufacturing method of the liquid crystal aligning film including the process of forming a coating film using the liquid crystal aligning agent in any one of Claims 1-5, and the process of providing liquid-crystal orientation ability by irradiating light to the said coating film. The manufacturing method of the liquid crystal aligning film including the process of forming a coating film using the liquid crystal aligning agent in any one of Claims 1-5, and the process of providing liquid-crystal orientation ability by rubbing the said coating film. The liquid crystal aligning film formed with 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 8.