WO2018062438A1

WO2018062438A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: WO2018062438A1
Application number: PCT/JP2017/035348
Authority: WO
Inventors: アルム金
Original assignee: 日産化学工業株式会社
Priority date: 2016-09-29
Filing date: 2017-09-28
Publication date: 2018-04-05
Also published as: CN109791329A; KR20190058569A; KR102453433B1; TWI817934B; JP7089229B2; CN109791329B; CN113805386A; JPWO2018062438A1; TWI813994B; TW201827578A; TW202132549A

Abstract

This liquid crystal aligning agent is characterized by containing: (A) at least one polymer selected from a polyamic acid and an imidized polymer thereof, said polyamic acid obtained using a tetracarboxylic acid dianhydride component, which contains tetracarboxylic acid dianhydride represented by expression (1) and aliphatic tetracarboxylic acid dianhydride in a ratio of 10:90 to 90:10, and a diamine component, which contains a diamine represented in expression (2); (B) at least one polymer selected from the group consisting of a polyimide precursor, an imidized polymer of said polyimide precursor, and a photosensitive side-chain acrylic polymer which exhibits liquid crystallinity within a prescribed temperature range; and an organic solvent.

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element

The present invention relates to a liquid crystal aligning agent used for a liquid crystal display element, a liquid crystal alignment film, and a liquid crystal display element using the same.

Conventionally, liquid crystal devices have been widely used as display units for personal computers, mobile phones, television receivers, and the like. The liquid crystal device includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, and a pixel A thin film transistor (TFT) for switching an electric signal supplied to the electrode is provided. As a driving method of liquid crystal molecules, a vertical electric field method such as a TN method and a VA method, and a horizontal electric field method such as an IPS method and a fringe field switching (hereinafter referred to as FFS) method are known (for example, Patent Document 1).

On the other hand, in recent years, liquid crystal display elements and organic EL elements are very important in terms of economical efficiency in the production process, and therefore, recycling of element substrates is required. That is, after a liquid crystal alignment film is formed from a liquid crystal alignment agent, if defects such as alignment are inspected, a rework process for removing the liquid crystal alignment film from the substrate and recovering the substrate is required to be easily performed. ing. However, the liquid crystal alignment film obtained from the conventionally proposed liquid crystal aligning agent is rather intended to be insolubilized in an organic solvent or the like after post-baking to reduce film loss. Moreover, even if the configuration of the liquid crystal aligning agent that has been studied for reworking so far is applied as it is to the configuration of the liquid crystal aligning agent for horizontal electric fields, the intended purpose is not necessarily achieved. It was necessary to re-evaluate the quality of the reworkability in the aligning agent and re-examine the optimum composition.

Also, liquid crystal display elements are currently widely used as display devices. A liquid crystal alignment film, which is a constituent member of a liquid crystal display element, is a film for uniformly arranging liquid crystals. However, not only the alignment uniformity of liquid crystals but also various characteristics are required. For example, in the manufacturing process of the liquid crystal alignment film, an alignment process called rubbing is generally performed by rubbing the surface of the polymer film with a cloth. However, if the rubbing resistance of the liquid crystal alignment film is insufficient, the film is scraped to generate scratches and dust, or the film itself is peeled off, thereby degrading the display quality of the liquid crystal display element. The liquid crystal display element is driven by applying a voltage to the liquid crystal. For this reason, when the voltage holding ratio (VHR) of the liquid crystal alignment film is low, a sufficient voltage is not applied to the liquid crystal, and the display contrast is lowered. In addition, when charge is accumulated in the liquid crystal alignment film due to the voltage for driving the liquid crystal and it takes time for the accumulated charge to be removed, a phenomenon such as afterimage or display burn-in occurs.

Various proposals have been made for satisfying some of the above required characteristics at the same time. For example, Patent Document 2 proposes a method for obtaining a liquid crystal alignment film that is excellent in rubbing resistance and has little afterimage and image sticking. Further, Patent Document 3 proposes a method for obtaining a liquid crystal alignment film having excellent liquid crystal alignment properties, alignment regulating power, and rubbing resistance, a high voltage holding ratio, and reduced charge accumulation.

JP 2013-167782 A International Publication No. WO02 / 33481 Pamphlet International Publication No. WO2004 / 053583 Pamphlet

An object of the present invention is to provide a liquid crystal aligning agent that can provide a liquid crystal aligning film that satisfies various properties required for the liquid crystal aligning film and is excellent in reworkability.

As a result of intensive studies to solve the above problems, the present inventors have a specific structure with a tetracarboxylic acid containing a specific aromatic tetracarboxylic dianhydride and an aliphatic tetracarboxylic dianhydride. It has been found that by using a polyamic acid obtained from diamine and an imidized polymer of polyamic acid, a liquid crystal alignment film satisfying various properties necessary for the liquid crystal alignment film and having excellent reworkability can be obtained. Completed.

Thus, the present invention is based on the above findings and has the following gist.
1. (A) A tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride represented by the following formula (1) and an aliphatic tetracarboxylic dianhydride in a ratio of 10:90 to 90:10, and the following formula At least one polymer selected from a polyamic acid obtained using a diamine component containing a diamine represented by (2) and an imidized polymer of the polyamic acid,
(B) at least one polymer selected from the group consisting of a polyimide precursor, an imidized polymer of the polyimide precursor, and a photosensitive side chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range; and A liquid crystal aligning agent comprising an organic solvent.

(In Formula (1), i is 0 or 1, X is a single bond, an ether bond, a carbonyl, an ester bond, phenylene, a linear alkylene having 1 to 20 carbon atoms, or a branched alkylene having 2 to 20 carbon atoms. , A group consisting of a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl, an amide bond, or a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is interrupted by a bond selected from an ester bond and an ether bond The carbon atoms of phenylene and alkylene may be substituted with one or more identical or different substituents selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups. Good.

In Formula (2), Y ₁ is a divalent organic group having at least one structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, and B ₁ and B ₂ are each independently A hydrogen atom or an optionally substituted alkyl group, alkenyl group, or alkynyl group. )

2. 10 to 100 mol% of the tetracarboxylic dianhydride component of the component (A) is a tetracarboxylic dianhydride and an aliphatic tetracarboxylic dianhydride represented by the formula (1). 2. The liquid crystal aligning agent according to 1, which is characterized.

3. 3. The liquid crystal aligning agent according to 1 or 2, wherein 10 to 100 mol% in the diamine component of the component (A) is a diamine of the formula (2).

4). 4. The liquid crystal aligning agent according to any one of 1 to 3, wherein Y ₁ in the formula (2) is at least one selected from structures of the following formulas (YD-1) to (YD-5).

(In the formula (YD-1), A ₁ is a nitrogen atom-containing heterocycle having 3 to 15 carbon atoms, and Z ₁ is a hydrogen atom or a hydrocarbon group having 1 to 20 prime groups which may have a substituent. In the formula (YD-2), W ₁ is a hydrocarbon group having 1 to 10 carbon atoms, and A ₂ is a monovalent organic group having 3 to 15 carbon atoms having a nitrogen atom-containing heterocyclic ring, or carbon A disubstituted amino group substituted with an aliphatic group having a number of 1 to 6. In the formula (YD-3), W ₂ is a divalent organic group having 6 to 15 carbon atoms and having 1 to 2 benzene rings. W ₃ is an alkylene or biphenylene having 2 to 5 carbon atoms, Z ₂ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a benzene ring, and a is an integer of 0 to 1. in the formula (YD-4), _{a 3} is a nitrogen atom-containing heterocyclic ring having 3 to 15 carbon atoms. formula (YD- In), _{A 4} is a nitrogen atom-containing heterocyclic ring having 3 to 15 carbon atoms, _{W 5} is alkylene having 2 to 5 carbon atoms.)

5). A ₁ , A ₂ , A ₃ , and A ₄ described in formulas (YD-1), (YD-2), (YD-4), and (YD-5) are pyrrolidine, pyrrole, imidazole, pyrazole, 5. The liquid crystal aligning agent according to 4, which is at least one selected from the group consisting of oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, and isoquinoline.

6). Y ₁ in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structures of the following formulas (YD-6) to (YD-21), and any one of 1 to 5 Liquid crystal aligning agent as described in one.

(In formula (YD-17), h is an integer of 1 to 3, and in formulas (YD-14) and (YD-21), j is an integer of 1 to 3).

7). Y ₁ in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structure of the above formulas (YD-14) and (YD-18), The liquid crystal aligning agent of description.

8. 8. The liquid crystal aligning agent according to any one of 1 to 7, wherein the tetracarboxylic dianhydride represented by the formula (1) is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride.

9. Any one of 1 to 8 wherein the aliphatic tetracarboxylic dianhydride is bicyclo [3.3.0] octane 2,4,6,8-tetracarboxylic acid 2,4: 6,8 dianhydride Liquid crystal aligning agent as described in.

A liquid crystal alignment film obtained by applying and baking the liquid crystal aligning agent according to any one of 10.1 to 9.

Liquid crystal display element which comprises the liquid crystal aligning film of 11.10.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention can suppress charge accumulation due to asymmetry of AC driving and is excellent in reworkability.

The liquid crystal aligning agent of the present invention comprises (A) a tetracarboxylic acid containing a tetracarboxylic dianhydride and an aliphatic tetracarboxylic dianhydride represented by the following formula (1) in a ratio of 10:90 to 90:10. At least one polymer selected from a polyamic acid obtained by using an acid dianhydride component and a diamine component containing a diamine represented by the following formula (2) and an imidized polymer of the polyamic acid, (B) At least one polymer selected from the group consisting of a polyimide precursor, an imidized polymer of the polyimide precursor, and a photosensitive side-chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range, and an organic solvent It is characterized by containing.

In the formula (1), i is 0 or 1, X is a single bond, an ether bond, a carbonyl, an ester bond, phenylene, a linear alkylene having 1 to 20 carbon atoms, a branched alkylene having 2 to 20 carbon atoms, A group comprising a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl, an amide bond or a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is interrupted by a bond selected from an ester bond and an ether bond. The carbon atoms of phenylene and alkylene may be substituted with one or more identical or different substituents selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups. .
In Formula (2), Y ₁ is a divalent organic group having at least one structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, and B ₁ and B ₂ are each independently A hydrogen atom or an optionally substituted alkyl group, alkenyl group, or alkynyl group.

Hereafter, each component requirement will be described in detail.

<(A) component>
(A) component used for the liquid crystal aligning agent of this invention is tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride represented by the said Formula (1) by the ratio of 10:90 to 90:10. A polyamic acid obtained by using a tetracarboxylic dianhydride component and a diamine component containing the diamine represented by the above formula (2), and at least one polymer selected from an imidized polymer of the polyamic acid. is there.

<Tetracarboxylic dianhydride component>
Examples of the tetracarboxylic dianhydride represented by the above formula (1) include, but are not limited to, the following compounds.

(Where q represents an integer from 1 to 20)

Of the tetracarboxylic dianhydrides represented by the formula (1), a tetracarboxylic dianhydride in which i is 1 in the formula (1), that is, two or more in terms of high reworkability improvement effect. The tetracarboxylic dianhydride having a benzene ring is preferably (1-2) to (1-11) in the above specific examples, and contains a biphenyl structure and has a rigid structure. 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride represented by (1-5) is particularly preferred.

Examples of the specific aliphatic tetracarboxylic dianhydride used in the present invention include tetracarboxylic dianhydrides represented by the following formula (3).

In the formula, X ₁ is any one of the following (X-1) to (X-28).

In the formula (X-1), R ₃ to R ₆ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, more preferably a hydrogen atom or a methyl group.

Among the above, (X-1) to (X-20) are preferable from the viewpoint that they do not contain an aromatic moiety, and (X-10) is most preferable from the viewpoint that thermal imidization is particularly difficult.

The total amount of the tetracarboxylic dianhydride and the aliphatic dianhydride represented by the formula (1) in the entire tetracarboxylic dianhydride component used for the production of the component (A) of the present invention is small. If it is too much, the effect of the present invention cannot be obtained. Therefore, the total amount of the tetracarboxylic dianhydride and the aliphatic dianhydride represented by the formula (1) is preferably 10 to 100 mol% with respect to 1 mol of the total tetracarboxylic dianhydride, Preferably, it is 50 to 100 mol%, more preferably 80 to 100 mol%.

The content ratio of the tetracarboxylic dianhydride represented by the formula (1) and the aliphatic dianhydride is 10:90 to 90:10, preferably 20:80 to 80:20. More preferably, the ratio is 40:60 to 60:40, particularly preferably 46:54 to 54:46, and most preferably substantially equivalent.

The tetracarboxylic dianhydride and the aliphatic tetracarboxylic dianhydride represented by the formula (1) may be used alone or in combination, respectively, but in that case, the formula (1) The total amount of the tetracarboxylic dianhydride and the aliphatic tetracarboxylic dianhydride represented by the above formula is preferably used.

The polyamic acid contained in the liquid crystal aligning agent of the present invention includes a tetracarboxylic acid dianhydride and an aliphatic tetracarboxylic dianhydride represented by the formula (1), as well as a tetra represented by the following formula (4). Carboxylic dianhydrides may be used.

In the formula (4), X is a tetravalent organic group, and its structure is not particularly limited. Specific examples include structures of the following formulas (X-31) to (X-36).

<Diamine component>
The diamine component used for the production of the liquid crystal aligning agent of the present invention contains the diamine of the above formula (2). In Formula (2), Y ₁ is a divalent organic group having at least one structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, and B ₁ and B ₂ are each independently A hydrogen atom or an optionally substituted alkyl group, alkenyl group, or alkynyl group.

Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkenyl group include those obtained by replacing one or more CH—CH structures present in the above alkyl group with C═C structures, and more specifically, vinyl groups, allyl groups, 1-propenyl groups. And isopropenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group, cyclopropenyl group, cyclopentenyl group, cyclohexenyl group and the like. Alkynyl groups include those in which one or more CH ₂ —CH ₂ structures present in the alkyl group are replaced with C≡C structures, and more specifically, ethynyl groups, 1-propynyl groups, 2 -Propynyl group and the like.

The above alkyl group, alkenyl group, and alkynyl group may have a substituent as long as it has 1 to 10 carbon atoms as a whole, and may further form a ring structure by the substituent. Note that forming a ring structure with a substituent means that the substituents or a substituent and a part of the mother skeleton are bonded to form a ring structure.

Examples of such substituents are halogen groups, hydroxyl groups, thiol groups, nitro groups, aryl groups, organooxy groups, organothio groups, organosilyl groups, acyl groups, ester groups, thioester groups, phosphate ester groups, amide groups, alkyls. A group, an alkenyl group and an alkynyl group.

Examples of the halogen group as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the aryl group that is a substituent include a phenyl group. This aryl group may be further substituted with the other substituent described above.

The organooxy group that is a substituent can have a structure represented by OR. The R may be the same or different, and examples thereof include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These Rs may be further substituted with the substituent described above. Specific examples of the alkyloxy group include methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group and the like.

As the organothio group which is a substituent, a structure represented by —S—R can be shown. Examples of R include the aforementioned alkyl group, alkenyl group, alkynyl group, aryl group, and the like. These Rs may be further substituted with the substituent described above. Specific examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, and an octylthio group.

The organosilyl group as a substituent can have a structure represented by —Si— (R) ₃ . The R may be the same or different, and examples thereof include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These Rs may be further substituted with the substituent described above. Specific examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a tripentylsilyl group, a trihexylsilyl group, a pentyldimethylsilyl group, and a hexyldimethylsilyl group.

The acyl group as a substituent can have a structure represented by —C (O) —R. Examples of R include the above-described alkyl group, alkenyl group, and aryl group. These Rs may be further substituted with the substituent described above. Specific examples of the acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, benzoyl group and the like.

As the ester group which is a substituent, a structure represented by —C (O) O—R or —OC (O) —R can be shown. Examples of R include the aforementioned alkyl group, alkenyl group, alkynyl group, aryl group, and the like. These Rs may be further substituted with the substituent described above.

As the thioester group which is a substituent, a structure represented by —C (S) OR— or —OC (S) —R can be shown. Examples of R include the aforementioned alkyl group, alkenyl group, alkynyl group, aryl group, and the like. These Rs may be further substituted with the substituent described above.

The phosphate group which is a substituent can have a structure represented by —OP (O) — (OR) ₂ . The R may be the same or different, and examples thereof include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These Rs may be further substituted with the substituent described above.

Examples of the substituent amide group include —C (O) NH ₂ , —C (O) NHR, —NHC (O) R, —C (O) N (R) ₂ , —NRC (O) R. The structure represented by can be shown. The R may be the same or different, and examples thereof include the alkyl group, alkenyl group, alkynyl group, and aryl group described above. These Rs may be further substituted with the substituent described above.

Examples of the aryl group as a substituent include the same aryl groups as described above. This aryl group may be further substituted with the other substituent described above.

Examples of the substituent alkyl group include the same alkyl groups as described above. This alkyl group may be further substituted with the other substituent described above.

Examples of the alkenyl group as a substituent include the same alkenyl groups as described above. This alkenyl group may be further substituted with the other substituent described above.

Examples of the alkynyl group as the substituent include the same alkynyl group as described above. This alkynyl group may be further substituted with the other substituent described above.

In general, when a bulky structure is introduced, the reactivity of the amino group and the liquid crystal alignment may be lowered. Therefore, as B ₁ and B ₂ , a hydrogen atom or a carbon atom that may have a substituent is 1 An alkyl group of 1 to 5 is more preferable, and a hydrogen atom, a methyl group, or an ethyl group is particularly preferable.

The structure of Y ₁ in the formula (2) is not particularly limited as long as it has at least one structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring. Absent. If specific examples are given, at least one kind selected from the group consisting of an amino group represented by the following formulas (YD-1) to (YD-5), an imino group, and a nitrogen-containing heterocyclic ring may be used. Examples thereof include a divalent organic group having a structure.

In formula (YD-1), A ₁ is a nitrogen atom-containing heterocyclic ring having 3 to 15 carbon atoms, and Z ₁ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. is there.

In the formula (YD-2), W ₁ is a hydrocarbon group having 1 to 10 carbon atoms, A ₂ is a monovalent organic group having 3 to 15 carbon atoms having a nitrogen atom-containing heterocyclic ring, or 1 carbon atom To a di-substituted amino group substituted with an aliphatic group of 1 to 6.

In the formula (YD-3), W ₂ is a divalent organic group having 6 to 15 carbon atoms and having 1 to 2 benzene rings, W ₃ is alkylene or biphenylene having 2 to 5 carbon atoms, Z ₂ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a benzene ring, and a is an integer of 0 to 1.

In the formula (YD-4), A ₃ is a nitrogen atom-containing heterocycle having 3 to 15 carbon atoms.

In the formula (YD-5), A ₄ is a nitrogen atom-containing heterocycle having 3 to 15 carbon atoms, and W ₅ is an alkylene having 2 to 5 carbon atoms.

A nitrogen-containing heterocycle having 3 to 15 carbon atoms of A ₁ , A ₂ , A ₃ , and A ₄ of formulas (YD-1), (YD-2), (YD-4), and (YD-5) As long as it is a known structure, it is not particularly limited. Among them, pyrrolidine, pyrrole, imidazole, pyrazole, oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline, isoquinoline, carbazole, piperazine, piperidine, indole, benzimidazole, imidazole, carbazole, and Pyridine is more preferred.

Furthermore, specific examples of Y ₂ in the formula (2) include divalent organic groups having nitrogen atoms represented by the following formulas (YD-6) to (YD-38). (YD-14) to (YD-21) are more preferable, and (YD-14) and (YD-18) are particularly preferable.

In the formulas (YD-14) and (YD-21), j is an integer from 0 to 3. In the formula (YD-17), h is an integer of 1 to 3.

(Formula YD-24), (YD-25), (YD-28) and (YD-29), j is an integer of 0 to 3.

The ratio of the diamine represented by the formula (2) in the polyamic acid and the imidized polymer of the polyamic acid of the present invention is preferably 10 to 100 mol%, more preferably 30%, based on 1 mol of the total diamine. To 100 mol%, more preferably 50 to 100 mol%.

The diamine represented by the formula (2) in the polyamic acid and the imidized polymer of the polyamic acid as the component (A) of the present invention may be used alone or in combination. The diamine represented by the formula (2) is preferably used in the above preferred amount as a total.

The polyamic acid contained in the liquid crystal aligning agent of the present invention may use a diamine represented by the following formula (5) in addition to the diamine represented by the above formula (2). Y ₂ in the following formula (5) is a divalent organic group, and the structure thereof is not particularly limited, and two or more kinds may be mixed. Specific examples thereof include the following (Y-1) to (Y-49) and (Y-57) to (Y-75).

In the polyamic acid which is the component (A) contained in the liquid crystal aligning agent of the present invention and the imidized polymer of polyamic acid, if the proportion of the diamine represented by the formula (5) increases, the effect of the present invention may be impaired. This is not preferable because of its properties. Therefore, the proportion of the diamine represented by the formula (5) is preferably 0 to 90 mol%, more preferably 0 to 50 mol%, still more preferably 0 to 20 mol% with respect to 1 mol of the total diamine. .

<Method for producing polyamic acid>
The polyamic acid which is a polyimide precursor used in the present invention can be synthesized by the following method.

Specifically, tetracarboxylic dianhydride and diamine are reacted in the presence of an organic solvent at −20 to 150 ° C., preferably 0 to 70 ° C., for 30 minutes to 24 hours, preferably 1 to 12 hours. Can be synthesized.

The organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, etc. in view of the solubility of the monomer and polymer. These may be used alone or in combination of two or more. May be used.

The concentration of the polymer is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is difficult to occur and a high molecular weight product is easily obtained.

The polyamic acid obtained as described above can be recovered by precipitating a polymer by pouring into a poor solvent while thoroughly stirring the reaction solution. Moreover, the powder of polyamic acid refine | purified by performing precipitation several times, washing | cleaning with a poor solvent, and normal temperature or heat-drying can be obtained. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene and the like, and water, methanol, ethanol, 2-propanol and the like are preferable.

<Production method of polyimide>
The polyimide used in the present invention can be produced by imidizing the polyamic acid.

When a polyimide is produced from a polyamic acid, chemical imidization in which a catalyst is added to the polyamic acid solution obtained by the reaction of a diamine component and tetracarboxylic dianhydride is simple. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer does not easily decrease during the imidization process.

Chemical imidation can be performed by stirring a polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As an organic solvent, the solvent used at the time of the polymerization reaction mentioned above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated.

The temperature for carrying out the imidization reaction is −20 to 140 ° C., preferably 0 to 100 ° C., and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times mol, preferably 2 to 20 times mol of the polyamic acid group, and the amount of acid anhydride is 1 to 50 times mol, preferably 3 to 30 times mol of the polyamic acid group. Is a mole. The imidation ratio of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

Since the added catalyst and the like remain in the solution after the imidization reaction of the polyamic acid, the obtained imidized polymer is recovered by the means described below, and redissolved in an organic solvent. It is preferable to use a liquid crystal aligning agent.

The polyimide solution obtained as described above can be polymerized by pouring into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a polymer powder purified by drying at normal temperature or by heating can be obtained.

Examples of the poor solvent include, but are not limited to, methanol, 2-propanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and the like. Methanol, ethanol, 2-propanol, Acetone is preferred.

<(B) component>
(B) component contained in the liquid crystal aligning agent of this invention consists of a polyimide precursor, the imidation polymer of this polyimide precursor, and the photosensitive side chain type acrylic polymer which expresses liquid crystallinity in a predetermined temperature range. It is at least one polymer selected from the group.

<Polyimide precursor>
The polyimide precursor is a polyimide precursor having a structural unit represented by the following formula (11).

In Formula (11), X ₁₁ is each independently a tetravalent organic group, and Y ₁₁ is each independently a divalent organic group. R ₁₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and A ₁₁ to A ₁₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may have a substituent, An alkenyl group having 2 to 10 carbon atoms or an alkynyl group having 2 to 10 carbon atoms.

Specific examples of the alkyl group in R ₁₁ include methyl group, ethyl group, propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, and n-pentyl group. Etc. From the viewpoint of ease of imidization by heating, R ₁₁ is preferably a hydrogen atom or a methyl group.

In the formula (11), X ₁₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. In the polyimide precursor, X ₁₁ is 2 or more may be mixed. Specific examples of X ₁₁ include structures of the following formulas (X-1) to (X-44).

R ₈ to R ₁₁ in the formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group, or phenyl. It is a group. When R ₈ to R ₁₁ have a bulky structure, the liquid crystal orientation may be lowered, so a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable.

In the formula (11), X ₁₁ preferably contains a structure selected from (X-1) to (X-14) from the viewpoint of availability of monomers.

A preferred ratio of the structure selected from the above formulas (X-1) to (X-14) is 20 mol% or more, more preferably 60 mol% or more, further preferably 80 mol% or more of the entire X _11. is there.

In the formula (11), A ₁₁ and A ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an alkyl group having 2 to 10 carbon atoms which may have a substituent. Or an alkynyl group having 2 to 10 carbon atoms which may have a substituent.

Specific examples and preferred examples of these A ₁₁ and A ₁₂ are the same as B ₁ and B ₂ in the above-mentioned items (A-1) and (A-2).

In Formula (11), Y ₁₁ is a divalent organic group derived from diamine, and its structure is not particularly limited. Specific examples of the structure of Y ₁₁ are as follows: (Y-1) to (Y-49) and (Y-57) to (Y-75) and (YD— 6) to (YD-38). In addition, the following (Y-76) to (Y-97) and (YD-39) to (YD-52) can be mentioned.

(In the formula (YD-50), m and n are each an integer from 1 to 11, and m + n is an integer from 2 to 12.)

The structure of Y ₁₁ is more preferably at least one selected from structures represented by the following formulas (15) and (16) from the viewpoint of liquid crystal alignment properties and pretilt angles of the obtained liquid crystal alignment film.

In the formula (15), R ₁₂ is a single bond or a divalent organic group having 1 to 30 carbon atoms, R ₁₃ is a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 30 carbon atoms, a is When R is an integer of 1 to 4 and a is 2 or more, R ₁₂ and R ₁₃ may be the same or different from each other, and R ₁₄ in formula (16) is a single bond, —O—, —S—. , —NR ₁₅ —, an amide bond, an ester bond, a urea bond, or a divalent organic group having 1 to 40 carbon atoms, and R ₁₅ is a hydrogen atom or a methyl group.

Specific examples of the formula (15) and the formula (16) include the following structures.
Since the structure with high linearity can enhance the alignment of the liquid crystal when it is used as a liquid crystal alignment film, Y- ₁₁ , Y-21, Y-22, Y-23, Y-25 are used as Y11. Y-43, Y-44, Y-45, Y-46, Y-48, Y-63, Y-71, Y-72, Y-73, Y-74, Y-75 are more preferable. The proportion of the above structure that can enhance the liquid crystal alignment is preferably 20 mol% or more of Y ₁₁ as a whole, more preferably 60 mol% or more, and further preferably 80 mol% or more.

When it is desired to increase the pretilt angle of the liquid crystal when the liquid crystal alignment film is used, it is preferable that Y ₁₁ has a long-chain alkyl group, an aromatic ring, an aliphatic ring, a steroid skeleton, or a combination of these in the side chain. . Examples of such Y ₁₁ include Y-76, Y-77, Y-78, Y-79, Y-80, Y-81, Y-82, Y-83, Y-84, Y-85, Y- 86, Y-87, Y-88, Y-89, Y-90, Y-91, Y-92, Y-93, Y-94, Y-95, Y-96, Y-97 are preferred. The proportion of the above structure for increasing the pretilt angle is preferably 1 to 30 mol%, more preferably 1 to 20 mol% of the entire Y ₁₁ .

Further, when a polyimide (precursor) having a photoalignable side chain is used as the polymer of the component (B), it is preferable to use a polyimide (precursor) having the following photoreactive side chain.

(R ¹⁶ is —CH ₂ —, —O—, —COO—, —OCO—, —NHCO—, —CONH—, —NH—, —CH ₂ O—, —N (CH ₃ ) —, —CON ( CH ₃ ) — or —N (CH ₃ ) CO—, and R ¹⁷ represents cyclic, unsubstituted, or alkylene having 1 to 20 carbon atoms, which is substituted by a fluorine atom. Arbitrary —CH ₂ — may be replaced by —CF ₂ — or —C═C—, and in the case where any of the following groups is not adjacent to each other, these groups may be replaced: --O--, --COO--, --OCO--, --NHCO--, --CONH--, --NH--, carbocycle, heterocycle, R ¹⁸ represents --CH _2- , --O--, --COO--, --OCO-- , -NHCO -, - NH -, - N (CH 3) -, - CO _{_{(CH 3) -, - N}} (CH 3) CO-, represent either carbocyclic or ^{heterocyclic,, R 19} is vinylphenyl ^{group, -CR} 20 = CH ₂ ^group, -CR 20 (OH) -CH ₃ groups, a carbocycle, a heterocyclic ring, or a structure represented by a formula selected from the following group is represented, and R ²⁰ represents a hydrogen atom or a methyl group optionally substituted with a fluorine atom.

When producing such a polyimide precursor, it is convenient to use a diamine substituted with a side chain represented by the above formula (b) as the diamine.

Also, a polyimide precursor having a photoalignable group in the main chain may be used. In this case, it is convenient to use a diamine having a bond containing a photoalignable group between the amine and the amine, as represented by the following formula (21).

(In the formula (21), X ²¹ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ²² represents —OCO—CH═CH— or —CH═CH—COO—, and X ²³ represents a single bond. , An alkylene group having 1 to 10 carbon atoms or a divalent benzene ring, X ²⁴ is a single bond, —OCO—CH═CH— or —CH═CH—COO—, and X ²⁵ is a single bond or carbon number 1 to 5 alkylene groups, with one or more cinnamoyl groups)

Examples of the diamine represented by the formula (21) include the following diamines.

Wherein X is independently a single bond or a linking group selected from ether (—O—), ester (—COO— or —OCO—) and amide (—CONH— or —NHCO—); Is independently a single bond or an alkylene group having 1 to 5 carbon atoms, and Z is independently an alkylene group or phenylene group having 1 to 10 carbon atoms, the bonding position of the amino group on the benzene ring, (The position of the bonding group with respect to the benzene ring is not particularly limited.)

Specific examples of the diamine represented by the formula (21) include the following diamines.

A liquid crystal alignment film formed by using a liquid crystal alignment agent containing a polyimide precursor such as polyamic acid or polyamic acid ester using a diamine represented by the above formula (21) as a raw material, polyimide or polyamide is AC. A change in liquid crystal alignment performance due to (alternating current) driving, for example, a change in alignment orientation of liquid crystal is reduced. Therefore, the liquid crystal display element having this liquid crystal alignment film has a stable liquid crystal alignment performance of the liquid crystal alignment film in AC driving, so that an afterimage is hardly generated by AC driving, that is, an afterimage characteristic by AC driving is very good. There is an effect. Moreover, the liquid crystal aligning film formed using the diamine represented by the said Formula (21) is excellent also in liquid crystal aligning performance itself, and can be made into a thing without an alignment defect substantially.

The polyimide precursor used in the present invention is obtained from a reaction between a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acid and polyamic acid ester.

<Polyimide precursor-production of polyamic acid>
Same as the description of the method for producing polyamic acid described in the section of the component (A-1) and the component (A-2).

<Polyimide precursor-production of polyamic acid ester>
The polyamic acid ester which is a polyimide precursor used in the present invention can be produced by the following production method (1), (2) or (3).

(1) When manufacturing from polyamic acid A polyamic acid ester can be manufactured by esterifying the polyamic acid manufactured as mentioned above. Specifically, the polyamic acid and the esterifying agent are reacted in the presence of an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 hours. Can be manufactured.

The esterifying agent is preferably one that can be easily removed by purification, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents per 1 mol of the polyamic acid repeating unit.

Examples of the organic solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl- Examples include imidazolidinone. When the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the formulas [D-1] to [D-3] described later The solvent shown by can be used.

These solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polyimide precursor, you may mix and use it for the said solvent in the range which the produced | generated polyimide precursor does not precipitate. Moreover, since water in the solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyimide precursor, it is preferable to use a dehydrated and dried solvent.

The solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in view of polymer solubility. These may be used alone or in combination of two or more. Good. The concentration at the time of production is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight product is easily obtained.

(2) When manufactured by reaction of tetracarboxylic acid diester dichloride and diamine The polyamic acid ester can be manufactured from tetracarboxylic acid diester dichloride and diamine.

Specifically, tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 hours. It can be produced by reacting.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. The addition amount of the base is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.

The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of the monomer and polymer, and these may be used alone or in combination. The polymer concentration at the time of production is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight product is easily obtained. In order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for the production of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

(3) When manufacturing from tetracarboxylic-acid diester and diamine Polyamic acid ester can be manufactured by polycondensing tetracarboxylic-acid diester and diamine.

Specifically, tetracarboxylic acid diester and diamine in the presence of a condensing agent, a base, and an organic solvent at 0 ° C. to 150 ° C., preferably 0 ° C. to 100 ° C., for 30 minutes to 24 hours, preferably 3 to 15 It can manufacture by making it react for time.

Examples of the condensing agent include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1,3,5-triazide. Nylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N , N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate diphenyl, and the like. The addition amount of the condensing agent is preferably 2 to 3 times the molar amount of the tetracarboxylic acid diester.
As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of the base added is preferably 2 to 4 times the mol of the diamine component from the viewpoint that it can be easily removed and a high molecular weight product can be easily obtained.

In the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0 to 1.0 times mol with respect to the diamine component.

Among the above three polyamic acid ester production methods, a high molecular weight polyamic acid ester is obtained, and therefore the production method (1) or (2) is particularly preferred.

The polymer solution can be precipitated by injecting the polyamic acid ester solution obtained as described above into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a purified polyamic acid ester powder can be obtained at room temperature or by heating and drying. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

<Polyimide>
The polyimide used in the present invention can be produced by imidizing the aforementioned polyamic acid ester or polyamic acid. It conforms to the description of the method for producing polyimide described in the section of component (A-1) and component (A-2).

<Photosensitive side chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range>
One aspect of the component (B) is a photosensitive side chain acrylic polymer that exhibits liquid crystallinity within a predetermined temperature range.

The side chain type acrylic polymer preferably reacts with light in the wavelength range of 250 nm to 400 nm and exhibits liquid crystallinity in the temperature range of 100 ° C. to 300 ° C.

The side chain acrylic polymer preferably has a photosensitive side chain that reacts with light in the wavelength range of 250 nm to 400 nm.

The side chain acrylic polymer preferably has a mesogenic group in order to exhibit liquid crystallinity in a temperature range of 100 ° C to 300 ° C.

The side chain type acrylic polymer has a photosensitive side chain bonded to the main chain, and can cause a crosslinking reaction, an isomerization reaction, or a light fleece rearrangement in response to light. The structure of the side chain having photosensitivity is not particularly limited, but a structure that undergoes a crosslinking reaction or photofleece rearrangement in response to light is desirable, and a structure that causes a crosslinking reaction is more desirable. In this case, even if exposed to external stress such as heat, the achieved orientation control ability can be stably maintained for a long period of time. The structure of the photosensitive side chain type acrylic polymer film capable of exhibiting liquid crystallinity is not particularly limited as long as it satisfies such characteristics, but preferably has a rigid mesogenic component in the side chain structure. In this case, when the side chain type acrylic polymer is used as a liquid crystal alignment film, stable liquid crystal alignment can be obtained.

The structure of the acrylic polymer has, for example, a main chain and a side chain bonded to the main chain, and the side chain includes a mesogenic component such as a biphenyl group, a terphenyl group, a phenylcyclohexyl group, a phenylbenzoate group, and an azobenzene group. A structure having a photosensitive group that is bonded to the tip and that undergoes a cross-linking reaction or an isomerization reaction in response to light, or a main chain and a side chain bonded thereto, and the side chain also serves as a mesogenic component, And it can be set as the structure which has the phenylbenzoate group which carries out a photo-Fries rearrangement reaction.

Specific examples of the structure of the photosensitive side chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range include hydrocarbons, (meth) acrylates, itaconates, fumarate, maleates, α-methylene-γ- A main chain composed of at least one selected from the group consisting of radically polymerizable groups such as butyrolactone, styrene, vinyl, maleimide, norbornene, and a side chain composed of at least one of the following formulas (31) to (35) It is preferable that the structure has

In the formula, Ar ₁ represents a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, naphthalene ring, pyrrole ring, furan ring, thiophene ring, or pyridine ring, and Ar ₂ and Ar ₃ are independent of each other. Represents a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, naphthalene ring, pyrrole ring, furan ring, thiophene ring or pyridine ring, q ¹ and q ² are one and one is 0 Each of Ar ₄ and Ar ₅ independently represents a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, naphthalene ring, pyrrole ring, furan ring, thiophene ring or pyridine ring, and Y ₁ -Y ₂ represents CH═CH, CH═N, N═CH or C≡C, S _{1 to} S ₃ each independently represent a single bond, a linear or branched alkylene having 1 to 18 carbon atoms, or the number of carbon atoms 5 to 8 Whether it represents loalkylene, phenylene or biphenylene, or one or more bonds selected from a single bond, ether bond, ester bond, amide bond, urea bond, urethane bond, amino bond, carbonyl, or a combination thereof Or a linear or branched alkylene having 1 to 18 carbon atoms, a cycloalkylene having 5 to 8 carbon atoms, phenylene, biphenylene, or a combination thereof, through one or more bonds. It may be a structure in which 2 or more and 10 or less sites are bonded, and the substituent may be a structure in which a plurality of the substituents are linked via the bond,
R ³¹ is a hydrogen atom, a hydroxy group, a mercapto group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, or 2 carbon atoms. 1 to 16 dialkylamino groups, wherein the benzene ring and / or naphthalene ring is one or more substituents selected from a halogen atom, a cyano group, a nitro group, a carboxyl group and an alkoxycarbonyl group having 2 to 11 carbon atoms. It may be substituted by a group. In this case, the alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, or a combination thereof, and may be substituted with a halogen atom.

The photosensitive side chain type acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range as the component (B) of the present application can contain liquid crystal side chains.

The mesogenic group possessed by the liquid crystalline side chain is a group that forms a mesogenic structure by hydrogen bonding between side chains, such as benzoic acid, even if it is a group that forms a mesogenic structure alone, such as biphenyl or phenylbenzoate. May be. As the mesogenic group possessed by the side chain, the following structure is preferable.

<< Production Method of Photosensitive Side Chain Polymer >>
The photosensitive side chain acrylic polymer exhibiting liquid crystallinity in the above-mentioned predetermined temperature range is obtained by polymerizing the photoreactive side chain monomer having the above photosensitive side chain and the liquid crystalline side chain monomer. Can do.

[Photoreactive side chain monomer]
The photoreactive side chain monomer is a monomer capable of forming a polymer having a photosensitive side chain at the side chain portion of the polymer when the polymer is formed.

The photoreactive group possessed by the side chain is preferably a structure represented by the above formulas (31) to (35).

More specific examples of the photoreactive side chain monomer include radical polymerizable groups such as hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, norbornene, etc. A structure having a polymerizable group composed of at least one selected from the group consisting of the above and a photosensitive side chain composed of at least one of the above formulas (31) to (35) is preferable.

[Liquid crystal side chain monomer]
The liquid crystalline side chain monomer is a monomer in which a polymer derived from the monomer exhibits liquid crystallinity and the polymer can form a mesogenic group at a side chain site.

More specific examples of liquid crystal side chain monomers include hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α-methylene-γ-butyrolactone, radical polymerizable groups such as styrene, vinyl, maleimide, norbornene, etc. A structure having a polymerizable group composed of at least one selected from the group and a side chain having at least one of the “mesogenic groups of the liquid crystalline side chain” is preferable.

The side chain type acrylic polymer which is one embodiment of the component (B) can be obtained by the polymerization reaction of the above-described photoreactive side chain monomer exhibiting liquid crystallinity. Further, it can be obtained by copolymerization of a photoreactive side chain monomer that does not exhibit liquid crystallinity and a liquid crystalline side chain monomer, or by copolymerization of a photoreactive side chain monomer that exhibits liquid crystallinity and a liquid crystalline side chain monomer. it can. Furthermore, it can be copolymerized with other monomers as long as the liquid crystallinity is not impaired.

Examples of other monomers include industrially available monomers capable of radical polymerization reaction.

Specific examples of other monomers include unsaturated carboxylic acid, acrylic ester compound, methacrylic ester compound, maleimide compound, acrylonitrile, maleic anhydride, styrene compound and vinyl compound.

Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the like.

Examples of the acrylic ester compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, tert-butyl. Acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- Propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, Beauty, etc. 8-ethyl-8-tricyclodecyl acrylate.

Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl. Methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2- Propyl-2-adamantyl methacrylate, 8-me Le -8- tricyclodecyl methacrylate, and, 8-ethyl-8-tricyclodecyl methacrylate. (Meth) acrylate compounds having a cyclic ether group such as glycidyl (meth) acrylate, (3-methyl-3-oxetanyl) methyl (meth) acrylate, and (3-ethyl-3-oxetanyl) methyl (meth) acrylate are also used. be able to.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

Examples of the styrene compound include styrene, methyl styrene, chlorostyrene, bromostyrene, and the like.

Examples of maleimide compounds include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

The method for producing the side chain polymer of the present embodiment is not particularly limited, and a general-purpose method that is handled industrially can be used. Specifically, it can be produced by cationic polymerization, radical polymerization, or anionic polymerization using a vinyl group of a liquid crystalline side chain monomer or photoreactive side chain monomer. Among these, radical polymerization is particularly preferable from the viewpoint of ease of reaction control.

As a polymerization initiator for radical polymerization, a known radical polymerization initiator such as AIBN (azobisisobutyronitrile) or a known compound such as a reversible addition-cleavage chain transfer (RAFT) polymerization reagent should be used. Can do.

The radical polymerization method is not particularly limited, and an emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, bulk polymerization method, solution polymerization method and the like can be used.

The organic solvent used for the polymerization reaction of the photosensitive side-chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range is not particularly limited as long as the produced polymer is soluble. Specific examples are given below.

N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide , Γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethyl Glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene Glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropiate Lenglycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n- Hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, Ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropio Acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3- Examples thereof include ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like.

These organic solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve the polymer | macromolecule to produce | generate, you may mix and use the above-mentioned organic solvent in the range which the polymer | macromolecule produced | generated does not precipitate.

Also, in radical polymerization, oxygen in the organic solvent causes the polymerization reaction to be inhibited. Therefore, it is preferable to use an organic solvent that has been degassed as much as possible.

The polymerization temperature at the time of radical polymerization can be selected from any temperature of 30 ° C. to 150 ° C., but is preferably in the range of 50 ° C. to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, the monomer concentration is preferably 1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

In the above-mentioned radical polymerization reaction, the molecular weight of the obtained polymer is decreased when the ratio of the radical polymerization initiator is large relative to the monomer, and the molecular weight of the obtained polymer is increased when the ratio is small, the ratio of the radical initiator is The content is preferably 0.1 mol% to 10 mol% based on the monomer to be polymerized. Further, various monomer components, solvents, initiators and the like can be added during the polymerization.

[Recovery of photosensitive side-chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range]
When recovering the produced polymer from the reaction solution of the photosensitive side chain polymer capable of exhibiting liquid crystallinity obtained by the above reaction, the reaction solution is put into a poor solvent, The coalescence can be precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer deposited in a poor solvent and precipitated can be recovered by filtration and then dried at normal temperature or under reduced pressure at room temperature or by heating. In addition, when the polymer collected by precipitation is redissolved in an organic solvent and reprecipitation and collection is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

The molecular weight of the photosensitive side chain type acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range, which is an embodiment of the component (B) of the present invention, is the strength of the resulting coating film and the workability during coating film formation. In consideration of the uniformity of the coating film, the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000. It is.

The content of the component (A) and the component (B) in the liquid crystal aligning agent of the present invention is such that the total ratio of the component (A) and the component (B) is 5:95 to 95: 5, 10: More preferably, it is 90 to 90:10.

In the liquid crystal aligning agent of the present invention, when the component (A) and the component (B) are polyimides (precursors), the imidation ratio of the component (B) can be arbitrarily adjusted according to the use and purpose, but the solubility From the viewpoint of charge storage characteristics, the imidation ratio of the specific polymer (A) component is preferably 0 to 55%, more preferably 0 to 20%. In addition, the specific polymer (B) preferably has a higher imidation ratio from the viewpoint of liquid crystal orientation, alignment regulating force, and voltage holding ratio, preferably 40% to 95%, more preferably 55 to 90%. It is.

<Liquid crystal aligning agent>
The liquid crystal aligning agent used in the present invention has a form of a solution in which a polymer component is dissolved in an organic solvent. The molecular weight of the polymer is preferably 2,000 to 500,000 in terms of weight average molecular weight, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.

The concentration of the polymer of the liquid crystal aligning agent used in the present invention can be appropriately changed by setting the thickness of the coating film to be formed, but it is 1 mass from the point of forming a uniform and defect-free coating film. % From the viewpoint of storage stability of the solution, and preferably 10% by mass or less. A particularly preferred polymer concentration is 2 to 8% by mass.

The organic solvent contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as the polymer component is uniformly dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, Examples include 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like. You may use these 1 type or in mixture of 2 or more types. Moreover, even if it is a solvent which cannot melt | dissolve a polymer component uniformly by itself, if it is a range which a polymer does not precipitate, you may mix with said organic solvent.

Moreover, the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the coating properties and the surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-described solvents. Such a mixed solvent is also preferably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent to be used in combination are given below, but the organic solvent is not limited to these examples.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6- Zimechi -4-heptanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3 -Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol Dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl Ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxy Butyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, Ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, Propylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, di Propylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether Ruacetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, Ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methylethyl 3-ethoxypropionate, 3-methoxypropionic acid Ethyl, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate Lactate ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, lactic acid isoamyl ester, and the like solvents represented by the following formula [D-1] ~ [D-3].

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and the formula [D-3] In the formula, D ³ represents an alkyl group having 1 to 4 carbon atoms.

Among these, preferred solvent combinations include N-methyl-2-pyrrolidone, γ-butyrolactone, ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and N-ethyl-2-pyrrolidone. And propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyro Examples thereof include lidone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether. The kind and content of such a solvent are appropriately selected according to the application device, application conditions, application environment, and the like of the liquid crystal aligning agent.

In addition, the following additives may be added to the liquid crystal aligning agent of the present invention in order to increase the mechanical strength of the film.

These additives are preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 parts by mass, the effect cannot be expected. If the amount exceeds 30 parts by mass, the orientation of the liquid crystal is lowered.

In the liquid crystal aligning agent of the present invention, in addition to the above, the purpose is to change the electrical properties such as the dielectric constant and conductivity of the polymer other than the polymer and the liquid crystal aligning film as long as the effects of the present invention are not impaired. A dielectric or conductive material, a silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film, and a coating. When firing the film, an imidization accelerator for the purpose of efficiently imidizing the polyamic acid may be added.

<Liquid crystal alignment film>
<Method for producing liquid crystal alignment film>
The liquid crystal alignment film of the present invention is a film obtained by applying the liquid crystal aligning agent to a substrate, drying and baking. The substrate on which the liquid crystal aligning agent of the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, an acrylic substrate, a polycarbonate substrate such as a polycarbonate substrate, or the like can be used. From the viewpoint of simplification of the process, it is preferable to use a substrate on which an ITO electrode or the like is formed. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light, such as aluminum, can also be used.

Examples of the method for applying the liquid crystal aligning agent of the present invention include a spin coating method, a printing method, and an ink jet method. Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent of the present invention. Usually, in order to sufficiently remove the organic solvent contained, drying is performed at 50 ° C. to 120 ° C. for 1 minute to 10 minutes, and then baking is performed at 150 ° C. to 300 ° C. for 5 minutes to 120 minutes. The thickness of the coating film after baking is not particularly limited, but if it is too thin, the reliability of the liquid crystal display element may be lowered, and therefore it is 5 to 300 nm, preferably 10 to 200 nm.

Examples of a method for aligning the obtained liquid crystal alignment film include a rubbing method and a photo-alignment processing method.
The rubbing process can be performed using an existing rubbing apparatus. Examples of the material of the rubbing cloth at this time include cotton, nylon, and rayon. As the conditions for rubbing treatment, generally, conditions of a rotational speed of 300 to 2000 rpm, a feed speed of 5 to 100 mm / s, and an indentation amount of 0.1 to 1.0 mm are used. Thereafter, the residue generated by rubbing is removed by ultrasonic cleaning using pure water or alcohol.

As a specific example of the photo-alignment treatment method, there is a method of imparting liquid crystal alignment ability by irradiating the coating film surface with radiation deflected in a certain direction, and further subjecting to a temperature of 150 to 250 ° C. in some cases. Can be mentioned. As the radiation, ultraviolet rays and visible rays having a wavelength of 100 nm to 800 nm can be used. Among these, ultraviolet rays having a wavelength of 100 nm to 400 nm are preferable, and those having a wavelength of 200 nm to 400 nm are particularly preferable. Further, in order to improve the liquid crystal orientation, radiation may be irradiated while heating the coated substrate at 50 to 250 ° C. Dose of the radiation is preferably 1 ~ 10,000mJ / cm ^2, particularly preferably 100 ~ 5,000mJ / cm ^2. The liquid crystal alignment film produced as described above can stably align liquid crystal molecules in a certain direction.

A higher extinction ratio of polarized ultraviolet light is preferable because higher anisotropy can be imparted. Specifically, the extinction ratio of linearly polarized ultraviolet light is preferably 10: 1 or more, and more preferably 20: 1 or more.

In the above, the film irradiated with polarized radiation may be contact-treated with a solvent containing at least one selected from water and an organic solvent.

The solvent used for the contact treatment is not particularly limited as long as it is a solvent that dissolves decomposition products generated by light irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, 3- Examples include methyl methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. Two or more of these solvents may be used in combination.

From the viewpoint of versatility and safety, at least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol and ethyl lactate is more preferable. Water, 2-propanol, and a mixed solvent of water and 2-propanol are particularly preferable.

In the present invention, the contact treatment between the film irradiated with polarized radiation and the solution containing the organic solvent is a treatment such that the film and the liquid are preferably sufficiently in contact with each other, such as immersion treatment or spraying treatment. Done. Among them, a method of immersing the film in a solution containing an organic solvent, preferably 10 seconds to 1 hour, more preferably 1 to 30 minutes is preferable. The contact treatment may be performed at normal temperature or preferably at 10 to 80 ° C., more preferably 20 to 50 ° C. Moreover, a means for enhancing contact such as ultrasonic waves can be applied as necessary.

After the above contact treatment, for the purpose of removing the organic solvent in the solution used, either rinsing (rinsing) with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, or drying, or both May be done.

Further, the film subjected to the contact treatment with the solvent as described above may be heated at 150 ° C. or more for the purpose of drying the solvent and reorienting the molecular chain in the film.

The heating temperature is preferably 150 to 300 ° C. A higher temperature promotes reorientation of molecular chains. However, if the temperature is too high, molecular chains may be decomposed. Therefore, the heating temperature is more preferably 180 to 250 ° C., and particularly preferably 200 to 230 ° C.

If the heating time is too short, the effect of reorientation of the molecular chain may not be obtained, and if it is too long, the molecular chain may be decomposed, and is preferably 10 seconds to 30 minutes. More preferred is ˜10 minutes.

Further, the obtained liquid crystal alignment film can be easily dissolved in the rework material and becomes a film excellent in reworkability.

Solvents used for reworking include: glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether; methyl cellosolve acetate, ethyl Glycol esters such as cellosolve acetate, propylene glycol monomethyl ether acetate and propylene glycol propyl ether acetate; glycols such as diethylene glycol, propylene glycol, butylene glycol and hexylene glycol; alcohols such as methanol, ethanol, 2-propanol and butanol; Acetone, methyl ethyl ketone, cyclope Ketones such as tanone, cyclohexanone, 2-heptanone, γ-butyrolactone; methyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3-methylbutanoic acid Methyl, methyl 3-methoxypropionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, etc. Esters, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and other amides.

As the rework material, a material containing a basic component such as ethanolamine in the solvent and a rust inhibitor so that the alkalinity does not damage other members such as an electrode is preferable. Examples of manufacturers that provide such rework materials include Korea's Aimei Sangyo Co., Ltd. and KPX Chemical.

In reworking, the above-mentioned reworking material is heated at room temperature or 30 ° C. to 100 ° C., and then the substrate with a liquid crystal alignment film is immersed in it for 1 second to 1000 seconds, preferably 30 seconds to 500 seconds, or After the rework material is sprayed by a shower method, the liquid is removed, and the rework material is washed with an alcohol solvent or pure water. In addition, the temperature of the rework liquid at the time of reworking is preferably lower from the viewpoint of work efficiency and the like, and is usually room temperature to 60 ° C, more preferably room temperature to 40 ° C.

<Liquid crystal display element>
In the liquid crystal display element of the present invention, after obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method for producing a liquid crystal alignment film, a liquid crystal cell is produced by a known method, and a liquid crystal cell is used. This is a display element.

As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Note that an active matrix liquid crystal display element in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion constituting the image display may be used.

First, a transparent glass substrate is prepared, a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be ITO electrodes, for example, and are patterned so as to display a desired image. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a film made of SiO ₂ —TiO ₂ formed by a sol-gel method.

Next, the liquid crystal alignment film of the present invention is formed on each substrate by the above method.

Next, one substrate is overlapped with the other substrate so that the alignment film surfaces face each other, and the periphery is bonded with a sealant. In order to control the substrate gap, a spacer is usually mixed in the sealant. Further, it is preferable that spacers for controlling the gap between the substrates are also sprayed on the in-plane portion where no sealant is provided. A part of the sealant is provided with an opening that can be filled with liquid crystal from the outside.

Next, a liquid crystal material is injected into the space surrounded by the two substrates and the sealing agent through the opening provided in the sealing agent. Thereafter, the opening is sealed with an adhesive. For the injection, a vacuum injection method may be used, or a method utilizing capillary action in the atmosphere may be used. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surfaces of the two substrates opposite to the liquid crystal layer. By passing through the above process, the liquid crystal display element of this invention is obtained.

In the present invention, as the sealing agent, for example, a resin that is cured by ultraviolet irradiation or heating having a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, an allyl group, or an acetyl group is used. In particular, it is preferable to use a cured resin system having reactive groups of both an epoxy group and a (meth) acryloyl group.

In the sealing agent of the present invention, an inorganic filler may be blended for the purpose of improving adhesiveness and moisture resistance. The inorganic filler that can be used is not particularly limited. Specifically, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, Calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, etc. Preferably, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide Beam, calcium silicate, aluminum silicate. Two or more of the above inorganic fillers may be mixed and used.

Since this liquid crystal display element uses the liquid crystal alignment film obtained by the method for producing a liquid crystal alignment film of the present invention as the liquid crystal alignment film, it has excellent reworkability and has a large screen and a high-definition liquid crystal television. It can be suitably used for such as.

The details of the production method of the present invention will be described below with reference to experimental methods and results obtained by examining the composition and blending ratio of raw materials, and examples that are typical production methods. The present invention is not limited to these examples.
Explanation of abbreviations used in this example (organic solvent)
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: Butyl cellosolvic dianhydride (A): Formula (A)
Acid dianhydride (B): the following formula (B)
Acid dianhydride (C): Formula (C) below
Acid dianhydride (D): Formula (D) below
Acid dianhydride (E): the following formula (E)
DA-1: Formula (DA-1) below
DA-2: Formula (DA-2) below
DA-3: Formula (DA-3) below
DA-4: Formula (DA-4) below
DA-5: The following formula (DA-5)
DA-6: The following formula (DA-6)
DA-7: Formula (DA-7) below
DA-8: The following formula (DA-8)
DA-9: The following formula (DA-9)
DA-10: The following formula (DA-10)
AD-1: Formula (AD-1) below
AD-2: Formula (AD-2) below

The following describes the methods for measuring viscosity, measuring imidization rate, evaluating reworkability, preparing liquid crystal cells, and evaluating charge relaxation characteristics.

[Measurement of viscosity]
In the synthesis example, the viscosity of the polyamic acid ester and the polyamic acid solution was measured using an E-type viscometer TV-25H (manufactured by Toki Sangyo Co., Ltd.), with a sample amount of 1.1 mL, CORD-1 (1 ° 34 ′, R24), Measurement was performed at a temperature of 25 ° C.

[Measurement of imidization rate]
Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.) and add 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture). The solution was completely dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) manufactured by JEOL Datum. The imidation rate is determined by determining a proton derived from a structure that does not change before and after imidation as a reference proton, and the peak integrated value of this proton and the proton peak derived from the NH group of amic acid that appears near 9.5 to 10.0 ppm. Using the integrated value, the following formula was used.

Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

[Evaluation of reworkability]
The liquid crystal aligning agent of the present invention was applied to a Cr substrate by spin coating. After drying on a hot plate at 60 ° C. for 1 minute and 30 seconds, baking was performed in a hot air circulation oven at 230 ° C. for 20 minutes to form a coating film having a thickness of 100 nm. Thereafter, the substrate prepared in the rework material heated to 55 ° C. was immersed for 300 seconds and developed, and then washed with running ultrapure water for 20 seconds. After that, air blow was performed, and the case where the liquid crystal alignment film completely disappeared was marked with “◯”, and the remaining film was marked with “X”. The obtained results are shown in Table 3.

[Production of liquid crystal cell]
A liquid crystal cell having a configuration of a fringe field switching (hereinafter referred to as FFS) mode liquid crystal display element is manufactured.

First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 50 mm and a thickness of 0.7 mm. On the substrate, an ITO electrode having a solid pattern constituting a counter electrode as a first layer is formed. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by the CVD method is formed as the second layer. The second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. On the second SiN film, a comb-like pixel electrode formed by patterning an ITO film as the third layer is arranged to form two pixels, a first pixel and a second pixel. ing. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.

The pixel electrode of the third layer has a comb-like shape configured by arranging a plurality of electrode elements having a dogleg shape whose central portion is bent. The width in the short direction of each electrode element is 3 μm, and the distance between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is formed by arranging a plurality of bent-shaped electrode elements in the central portion, the shape of each pixel is not rectangular, but in the central portion like the electrode elements. It has a shape that bends and resembles a bold-faced koji. Each pixel is divided into upper and lower portions with a central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.

When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise) in the first region of the pixel, and the pixel in the second region of the pixel. The electrode elements of the electrode are formed so as to form an angle of −10 ° (clockwise). That is, in the first region and the second region of each pixel, the directions of the rotation operation (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode are mutually in the substrate plane. It is comprised so that it may become a reverse direction.

Next, after filtering the obtained liquid crystal aligning agent through a 1.0 μm filter, the prepared substrate with electrodes and a glass substrate having a columnar spacer with a height of 4 μm on which an ITO film is formed on the back surface, It applied by spin coat application. After drying on an 80 ° C. hot plate for 5 minutes, baking was carried out in a hot air circulating oven at 230 ° C. for 20 minutes to form a coating film having a thickness of 100 nm. This coating surface was subjected to alignment treatment such as rubbing and polarized ultraviolet irradiation to obtain a substrate with a liquid crystal alignment film. The two substrates are combined as a set, a sealant is printed on the substrate, and the other substrate is bonded so that the liquid crystal alignment film faces and the alignment direction is 0 °, and then the sealant is added. An empty cell was produced by curing. Liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS drive liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour and allowed to stand overnight before being used for each evaluation.

[Charge relaxation characteristics evaluation]
After placing the above liquid crystal cell on a light source and measuring VT characteristics (voltage-transmittance characteristics) at room temperature, the transmittance (Ta of the liquid crystal cell with a square wave of ± 1.5 V / 60 Hz applied) (Ta ) Was measured. After that, the transmittance (Tb) of the liquid crystal cell is measured while driving for 30 minutes with DC 1V superimposed, the liquid crystal cell when the DC voltage is cut off and driven again for 20 minutes only with ± 1.5V / 60Hz rectangular wave. The transmittance (Tc) is measured, and the difference in transmittance caused by the voltage remaining in the liquid crystal display element from the difference (ΔT) between the transmittance (Tb, Tc) at each time and the initial transmittance (Ta). Was calculated. It is considered that the seizure hardly occurs as the remaining voltage is relaxed earlier. When (Tb-Ta) is 5 minutes after the start of DC voltage application, 2% or less is marked as ◯, when x is above, and when (Tc-Ta) is cut off the DC voltage, 2% or less is marked as ◯, and above is marked as x. The obtained results are shown in Table 3.

(Comparative polymerization example 1)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.96 g of (DA-3) were added, 25.7 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring this diamine solution, 3.00 g of acid dianhydride (C) was added, 11.2 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere, and then acid dianhydride (D). Was added, and 4.4 g of NMP was further added, followed by stirring at 23 ° C. for 2 hours under a nitrogen atmosphere. Thereafter, the mixture was stirred at 50 ° C. for 16 hours to obtain a polyamic acid solution (PAA-1). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 358 cps.

(Comparative polymerization example 2)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.46 g of (DA-2) were added, 22.3 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring the diamine solution, 2.00 g of acid dianhydride (C) was added, 6.3 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere, and then acid dianhydride (D). 1.51 g was added, 8.5 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours under a nitrogen atmosphere. Thereafter, the mixture was stirred at 50 ° C. for 16 hours to obtain a polyamic acid solution (PAA-2). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 333 cps.

(Polymerization example 1)
A 100 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 0.58 g of (DA-6), 1.32 g of (DA-4), 0.93 g of (DA-5), and (DA-7) 3.01 g was taken, 42.8 g of NMP was added, and the mixture was stirred and dissolved at 23 ° C. while feeding nitrogen. While stirring this diamine solution, 3.91 g of acid dianhydride (E) was added, and 12.4 g of NMP was further added, and the mixture was stirred at 40 ° C. for 16 hours in a nitrogen atmosphere to obtain a polyamic acid solution (PAA-3). Got. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 450 cps.

(Polymerization example 2)
A 100 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 6.19 g of (DA-9) and 2.14 g of (DA-8) were added, 61.1 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring this diamine solution, 5.71 g of acid dianhydride (B) was added, and 18.5 g of NMP was further added. The mixture was stirred at 50 ° C. for 16 hours under a nitrogen atmosphere, and the polyamic acid solution (PAA-4) was added. Obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 351 cps.

(Polymerization Example 3)
A 1 L four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 86.0 g of (DA-4), 53.4 g of (DA-7), 76.5 g of (DA-10) were taken, 1580 g of NMP were added, The mixture was stirred at a temperature of 23 ° C. while feeding nitrogen. While stirring this diamine solution, 93.2 g of acid dianhydride (E) was added, 168 g of NMP was further added, and the mixture was stirred at 40 ° C. for 3 hours in a nitrogen atmosphere. Further, 28.2 g of acid dianhydride (D) was added, 160 g of NMP was further added, and the mixture was stirred at 23 ° C. for 4 hours under a nitrogen atmosphere to obtain a polyamic acid solution (PAA-5). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 200 mPa · s.

(Polymerization example 4)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.78 g of (DA-4) were added, 24.4 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring the diamine solution, 1.75 g of acid dianhydride (B) was added, 4.3 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere, and then acid dianhydride (D). 1.41 g was added, 8.0 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred at 50 ° C. for 16 hours to obtain a polyamic acid solution (PAA-6). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 240 cps.

(Polymerization Example 5)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.49 g of (DA-2) were added, 22.3 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring this diamine solution, 2.35 g of acid dianhydride (A) was added, 8.3 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours under a nitrogen atmosphere, and then acid dianhydride (C). Was added, and 10.2 g of NMP was further added, followed by stirring at 23 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred at 70 ° C. for 16 hours to obtain a polyamic acid solution (PAA-7). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 380 cps.

(Polymerization Example 6)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.49 g of (DA-2) were added, 22.3 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring this diamine solution, 2.35 g of acid dianhydride (A) was added, 8.3 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere, and then acid dianhydride (D). 1.41 g was added, 8.0 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred at 70 ° C. for 16 hours to obtain a polyamic acid solution (PAA-8). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 321 cps.

(Polymerization Example 7)
A 50 mL four-necked flask equipped with a stirrer was placed in a nitrogen atmosphere, 2.55 g of (DA-1) and 0.49 g of (DA-2) were added, 22.3 g of NMP was added, and the mixture was stirred while feeding nitrogen. It was dissolved at ° C. While stirring this diamine solution, 1.41 g of acid dianhydride (A) was added, 2.9 of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere, and then acid dianhydride (B). 1.41 g was added, and 7.9 g of NMP was further added, followed by stirring at 23 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, 1.00 g of acid dianhydride (C) was added, 5.7 g of NMP was further added, and the mixture was stirred at 23 ° C. for 2 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred at 70 ° C. for 16 hours to obtain a polyamic acid solution (PAA-9). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 365 cps.

(Comparative Example 1)
In a 50 mL Erlenmeyer flask containing a stir bar, NMP containing 6.73 g of the polyamic acid solution (PAA-3) obtained in the comparative synthesis example, 15.27 g of (PAA-1), and 1 wt% of (AD-1) 2.40 g of the solution and 0.72 g of NMP solution containing 10 wt% of (AD-2) were collected, 2.88 g of NMP and 12.00 g of BCS were added, and the mixture was stirred for 2 hours with a magnetic stirrer. An aligning agent (A-1) was obtained.

(Comparative Example 2)
In a 50 mL Erlenmeyer flask containing a stir bar, NMP containing 4.00 g of the polyamic acid solution (PAA-4) obtained in the comparative synthesis example, 12.80 g of (PAA-2), and 1 wt% of (AD-1) 2.40 g of the solution was fractionated, 8.80 g of NMP and 12.00 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours to obtain a liquid crystal aligning agent (A-2).

(Comparative Example 3)
In a 3 L Erlenmeyer flask containing a stir bar, 800 g of the polyamic acid solution (PAA-5) obtained in (Polymerization Example 3) was collected, 700 g of NMP, 69.7 g of acetic anhydride, and 18.0 g of pyridine. In addition, the mixture was stirred at room temperature for 30 minutes and then reacted at 55 ° C. for 3 hours. This reaction solution was put into 5600 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 60 ° C. to obtain a polyimide powder. The imidation ratio of this polyimide powder was 75%.
In a 300 mL Erlenmeyer flask containing a stir bar, 20.4 g of this polyimide powder was taken, 150 g of NMP was added, and the mixture was stirred and dissolved at 50 ° C. for 20 hours to obtain a polyimide solution (SPI-1). .
In a 50 mL Erlenmeyer flask containing a stir bar, NMP solution containing 7.00 g of the polyimide solution (SPI-1) obtained above, 10.40 g of (PAA-6), and 1 wt% of (AD-1) was added. .40 g, 0.72 g of NMP solution containing 10 wt% of (AD-2) was taken out, 7.48 g of NMP and 12.00 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours. A-3) was obtained.

(Examples 1 to 3)
In a 50 mL Erlenmeyer flask containing a stir bar, 7.00 g of the polyimide solution (SPI-1) obtained in (Comparative Example 3) and the polyamic acid solution (PAA-7˜) obtained in (Polymerization Examples 5-7) were added. 9.40 g of NMP was taken, 2.40 g of NMP solution containing 1 wt% of (AD-1), 0.72 g of NMP solution containing 10 wt% of (AD-2), and 7. 48 g and 12.00 g of BCS were added and stirred with a magnetic stirrer for 2 hours to obtain liquid crystal aligning agents (B-1 to 3) as shown in Table 1.

(Examples 4 to 6)
To a 50 mL Erlenmeyer flask containing a stir bar, 4.00 g of the polyamic acid solution (PAA-4) obtained in (Polymerization Example 2) and the polyamic acid solution (PAA-7) obtained in (Polymerization Examples 5 to 7) To 9) 12.80 g and 2.40 g of NMP solution containing 1 wt% of (AD-1) were collected, 4.80 g of NMP and 12.00 g of BCS were added, and the mixture was stirred with a magnetic stirrer for 2 hours. As shown in Table 2, liquid crystal aligning agents (B-4 to 6) were obtained.

(Example 7)
In a 50 mL Erlenmeyer flask containing a stirring bar, NMP containing 6.00 g of the polyamic acid solution (PAA-7) obtained in the comparative synthesis example, 11.20 g of (PAA-1), and 1 wt% of (AD-1) 2.40 g of the solution and 0.72 g of NMP solution containing 10 wt% of (AD-2) were separated, 7.68 g of NMP and 12.00 g of BCS were added, and the mixture was stirred for 2 hours with a magnetic stirrer. An aligning agent (B-7) was obtained.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention reduces charge accumulation due to AC drive asymmetry in an IPS drive type or FFS drive type liquid crystal display element, and quickly relaxes the residual charge accumulated by a DC voltage. Therefore, an IPS drive type or FFS drive type liquid crystal display element having excellent afterimage characteristics can be obtained. Therefore, it is particularly useful as a liquid crystal alignment film of an IPS driving type or FFS driving type liquid crystal display element or a liquid crystal television.

Claims

(A) A tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride represented by the following formula (1) and an aliphatic tetracarboxylic dianhydride in a ratio of 10:90 to 90:10, and the following formula At least one polymer selected from a polyamic acid obtained using a diamine component containing a diamine represented by (2) and an imidized polymer of the polyamic acid,
(B) at least one polymer selected from the group consisting of a polyimide precursor, an imidized polymer of the polyimide precursor, and a photosensitive side chain acrylic polymer that exhibits liquid crystallinity in a predetermined temperature range; and A liquid crystal aligning agent comprising an organic solvent.

(In Formula (1), i is 0 or 1, X is a single bond, an ether bond, a carbonyl, an ester bond, phenylene, a linear alkylene having 1 to 20 carbon atoms, or a branched alkylene having 2 to 20 carbon atoms. , A group consisting of a cyclic alkylene having 3 to 12 carbon atoms, a sulfonyl, an amide bond, or a combination thereof, wherein the alkylene having 1 to 20 carbon atoms is interrupted by a bond selected from an ester bond and an ether bond The carbon atoms of phenylene and alkylene may be substituted with one or more identical or different substituents selected from halogen atoms, cyano groups, alkyl groups, haloalkyl groups, alkoxy groups and haloalkoxy groups. Good.
In Formula (2), Y 1 is a divalent organic group having at least one structure selected from the group consisting of an amino group, an imino group, and a nitrogen-containing heterocyclic ring, and B 1 and B 2 are each independently A hydrogen atom or an optionally substituted alkyl group, alkenyl group, or alkynyl group. )
10 to 100 mol% of the tetracarboxylic dianhydride component of the component (A) is a tetracarboxylic dianhydride and an aliphatic tetracarboxylic dianhydride represented by the formula (1). The liquid crystal aligning agent of Claim 1 characterized by the above-mentioned.
The liquid crystal aligning agent according to claim 1 or 2, wherein 10 to 100 mol% of the diamine component of the component (A) is a diamine of the formula (2).
4. The liquid crystal aligning agent according to claim 1, wherein Y 1 in the formula (2) is at least one selected from the structures of the following formulas (YD-1) to (YD-5).

(In the formula (YD-1), A 1 is a nitrogen atom-containing heterocycle having 3 to 15 carbon atoms, and Z 1 is a hydrogen atom or a hydrocarbon group having 1 to 20 prime groups which may have a substituent. In the formula (YD-2), W 1 is a hydrocarbon group having 1 to 10 carbon atoms, and A 2 is a monovalent organic group having 3 to 15 carbon atoms having a nitrogen atom-containing heterocyclic ring, or carbon A disubstituted amino group substituted with an aliphatic group having a number of 1 to 6. In the formula (YD-3), W 2 is a divalent organic group having 6 to 15 carbon atoms and having 1 to 2 benzene rings. W 3 is an alkylene or biphenylene having 2 to 5 carbon atoms, Z 2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a benzene ring, and a is an integer of 0 to 1. in the formula (YD-4), a 3 is a nitrogen atom-containing heterocyclic ring having 3 to 15 carbon atoms. formula (YD- In), A 4 is a nitrogen atom-containing heterocyclic ring having 3 to 15 carbon atoms, W 5 is alkylene having 2 to 5 carbon atoms.)
A 1 , A 2 , A 3 , and A 4 described in formulas (YD-1), (YD-2), (YD-4), and (YD-5) are pyrrolidine, pyrrole, imidazole, pyrazole, 5. The liquid crystal aligning agent according to claim 4, wherein the liquid crystal aligning agent is at least one selected from the group consisting of oxazole, thiazole, piperidine, piperazine, pyridine, pyrazine, indole, benzimidazole, quinoline and isoquinoline.
The Y 1 in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structures of the following formulas (YD-6) to (YD-21). The liquid crystal aligning agent of any one of Claims.

(In Formula (YD-17), h is an integer of 1 to 3, and in Formulas (YD-14) and (YD-21), j is an integer of 1 to 3.)
The Y 1 in the formula (2) is at least one selected from the group consisting of divalent organic groups having the structure of the above formulas (YD-14) and (YD-18). Liquid crystal aligning agent as described in.
The tetracarboxylic dianhydride represented by the formula (1) is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, according to any one of claims 1 to 7. Liquid crystal aligning agent.
9. The aliphatic tetracarboxylic dianhydride is bicyclo [3.3.0] octane 2,4,6,8-tetracarboxylic acid 2,4: 6,8 dianhydride. The liquid crystal aligning agent of any one of Claims.
A liquid crystal alignment film obtained by applying and baking the liquid crystal aligning agent according to any one of claims 1 to 9.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 10.