WO2017090691A1

WO2017090691A1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element

Info

Publication number: WO2017090691A1
Application number: PCT/JP2016/084841
Authority: WO
Inventors: 石川　和典; 夏樹佐藤
Original assignee: 日産化学工業株式会社
Priority date: 2015-11-25
Filing date: 2016-11-24
Publication date: 2017-06-01
Also published as: KR20180085003A; TWI704183B; JP6747452B2; CN108604027A; JPWO2017090691A1; TW201731958A

Abstract

Provided is a liquid crystal aligning agent which has excellent storage stability and is capable of providing a liquid crystal alignment film that exhibits excellent rubbing resistance, excellent liquid crystal alignment stability and quick reduction of accumulated charge, while being suppressed in flickering (namely, being at a low flicker level) immediately after driving. A liquid crystal aligning agent which contains: a polyamic acid ester having a specific repeating unit having a structure of formula (Y1-1) and a specific repeating unit having a structure of formula (Y2-1) (component A); and a polyamic acid having a specific structure (component B). (In the formulae, the symbols are as defined in the description.)

Description

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

The present invention relates to a liquid crystal alignment agent used for preparing a liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

Currently, liquid crystal display elements are widely used in image display portions of many devices such as digital cameras, personal computers, portable terminals, and televisions. Such a liquid crystal display element has a structure in which a liquid crystal composition having fluidity is sandwiched and sealed between two support substrates, and a liquid crystal alignment for aligning liquid crystal molecules on the surface of the substrate in contact with the liquid crystal. A membrane is provided. The liquid crystal alignment film is generally produced through a step of applying a liquid crystal aligning agent on the substrate. Moreover, when aligning liquid crystal molecules in the in-plane direction of the substrate, a rubbing treatment, a photo-alignment treatment, or the like is performed on the film obtained from the liquid crystal aligning agent.

The basic characteristics required of the liquid crystal alignment film are to align the liquid crystal molecules in a predetermined direction, but various other improvements are required to realize a high-performance liquid crystal display element. Furthermore, in stable industrial production, characteristics such as coating properties and storage stability of the liquid crystal aligning agent are important. For example, Patent Document 1 discloses a liquid crystal aligning agent for the purpose of providing a liquid crystal alignment film that is less likely to be scraped or scratched by rubbing. In addition to the rubbing resistance of the film, Patent Document 2 can suppress a deviation between the rubbing direction and the alignment direction of the liquid crystal, has a high voltage holding ratio when used as a liquid crystal display element, and quickly relieves accumulated charges. A liquid crystal aligning agent for the purpose of providing a liquid crystal aligning film that can be produced is disclosed.

International Publication WO2010 / 053128 Pamphlet International Publication WO2015 / 122413 Pamphlet

With recent increase in performance of liquid crystal display elements, liquid crystal alignment films are required to realize various characteristics at a higher level than before. For example, as the liquid crystal display element has been made higher in definition, smaller rubbing and scratches have become a problem with respect to rubbing resistance. In addition, it is also required to simultaneously realize other characteristics.

From the above, the present invention is excellent in rubbing resistance and stability of liquid crystal alignment, a liquid crystal alignment film in which the accumulated charge of the liquid crystal display element is quickly relaxed, and flicker immediately after driving the liquid crystal display element (flicker level) It is an object of the present invention to provide a liquid crystal aligning agent that can obtain a liquid crystal aligning film having a small size and is excellent in storage stability.

As a result of repeated studies, the present inventors have completed the present invention, and the present invention is summarized as follows.
The liquid crystal aligning agent characterized by containing the following (A) component and (B) component.
(A) Component: Polyamic acid ester containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).
Component (B): a polyamic acid having a repeating unit represented by the following formula (3).

(In Formula (1) and Formula (2), a plurality of R ¹ are each independently an alkyl group having 1 to 6 carbon atoms, and a plurality of R ² are each independently a hydrogen atom or a carbon number) 1 to 6 are alkyl groups, Y ¹ is a divalent organic group represented by the following formula (Y1-1), and Y ² is a divalent organic group represented by the following formula (Y2-1). .)

In formula (Y1-1), two R ³ are each independently a single bond, —O—, —S—, —OCO—, or —COO—, and the two R ⁴ are each independently An alkylene group having 1 to 3 carbon atoms, and R ⁵ is an oxygen atom or a sulfur atom.

In formula (Y2-1), A ¹ and A ⁵ are each independently a single bond, methylene, alkylene having 2 to 5 carbon atoms, azetidine diyl, pyrrolidine diyl, or piperidine diyl, and B ¹ and B ² are each independently single bond, -O and -, - COO -, - OCO -, - CONH -, - NHCO -, - CONCH 3 -, or -NCH ₃ is CO-, ^{a 2} and ^{a 4} each independently represent a single A bond, methylene, or alkylene having 2 to 5 carbon atoms; A ³ is methylene or alkylene having 2 to 6 carbon atoms; a is 0 or 1; R is a hydrogen atom or a methyl group; Is a protecting group that is replaced by a hydrogen atom by heat.

In the formula (3), X is a tetravalent organic group, Y is a divalent organic group, and R ⁶ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

According to the present invention, a liquid crystal alignment film that has excellent rubbing resistance and stability of liquid crystal alignment and has a fast relaxation of stored charge of the liquid crystal display element, and further a liquid crystal with a small flicker (flicker level) immediately after the liquid crystal display element is driven. An alignment film can be obtained, and a liquid crystal alignment agent having excellent storage stability, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a high-performance liquid crystal display device including the liquid crystal alignment film can be provided. .

<Polyamic acid ester (A)>
The polyamic acid ester as the component (A) is a polyamic acid ester containing a repeating unit represented by the above formula (1) and a repeating unit represented by the following formula (2).
In formula (1) and formula (2), a plurality of R ¹ are each independently an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group. In the formulas (1) and (2), a plurality of R ² are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or a methyl group.

In formula (1), Y ¹ is a divalent organic group represented by the following formula (Y1-1).

In formula (Y1-1), R ³ , R ⁴ , and R ⁵ are as defined above. Among them, R ³ is preferably a single bond, —O—, and R ⁴ is preferably a methylene group, R ⁵ is preferably an oxygen atom.

Specific examples of Y ¹ are given below, but the present invention is not limited thereto.

Among these, (Y1-1-1) to (Y1-1-8) are preferable from the viewpoint of the alignment stability of the liquid crystal. In addition, the (containing) ratio of the repeating unit represented by the formula (1) is preferably 1 to 70 mol% of all repeating units contained in the polyamic acid ester as the component (A), more preferably. Is 5 to 50 mol%.

In the formula (2), Y ² is a divalent organic group represented by the following formula (Y2-1).

In the formula (Y2-1), A ¹ and A ⁵ are B ¹ , B ² , A ² , A ³ , A ⁴ , R, and a are as defined above. Among these, A ¹ and A ⁵ are preferably a single bond, a methylene group, an ethylene group or a propylene group. When A ¹ or A ⁵ is an aliphatic heterocycle such as azetidinediyl, pyrrolidinediyl, piperidinediyl, etc., azetidine-1,3-diyl, pyrrolidine-1,3-diyl, or piperidine-1,4-diyl It is preferable that the nitrogen atom in the ring is bonded to the adjacent benzene ring.
B ¹ and B ² are preferably a single bond or —O—. A ² and A ⁴ are preferably a single bond, a methylene group, an ethylene group, or a propylene group. A ³ is preferably an ethylene group. a is preferably 0. R is preferably a hydrogen atom.

In formula (Y2-1), D is a protecting group that is replaced with a hydrogen atom by heat, and is not detached at room temperature from the viewpoint of the storage stability of the liquid crystal aligning agent, and is detached by heating in the manufacturing process of the liquid crystal alignment film. Thus, a group that replaces a hydrogen atom is preferred. A preferable desorption temperature is 80 to 200 ° C, more preferably 100 to 200 ° C, and particularly preferably 150 to 200 ° C. Specific examples of such groups include 1,1-dimethyl-2-chloroethoxycarbonyl group, 1,1-dimethyl-2-cyanoethoxycarbonyl group, tert-butoxycarbonyl group, or 9-fluorenylmethoxycarbonyl group. Preferred are a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl V group, and particularly preferred is a tert-butoxycarbonyl group.

Of the divalent organic groups represented by the above formula (Y2-1), preferable combinations of A ¹ to A ⁵ , B ¹ , B ² and a include the combinations of types 1 to 3 shown below. More preferably, type 1 or type 2 is preferable, and type 1 is particularly preferable.

Type 1: A ¹ and A ⁵ are independently a single bond, methylene, alkylene having 2 to 5 carbon atoms, and B ¹ and B ² are independently a single bond, —O—, —COO—, —OCO. -, - CONH -, - NHCO -, - CONCH 3 -, or -NCH ₃ is CO-, ^{a 2} and ^{a 4} are independently methylene or alkylene having a carbon number of 2 ~ 5, ^{a 3} is methylene Or alkylene having 2 to 6 carbon atoms, and a is 0 or 1.
More preferably, A ¹ and A ⁵ are both a single bond, B ¹ and B ² are independently a single bond or —O—, and A ² and A ⁴ are independently methylene, or a group having 2 to 5 is alkylene, A ³ is methylene or alkylene having 2 to 6 carbon atoms, and a is 0 or 1.

Type 2: A ¹ and A ⁵ are independently a single bond, azetidinediyl, pyrrolidinediyl, or piperidinediyl, B ¹ and B ² are both single bonds, and A ² and A ⁴ are independently methylene, or An alkylene having 2 to 5 carbon atoms and a is 0; More preferably, ^{A 1} is Azechijinjiiru a pyrrolidinediyl or piperidine-diyl, ^{A 2} is an alkylene methylene, or C ^{^{2 ~ 5, A 4, A}} 5, B 1 and ^{B 2} is a single bond , A is 0.
Type 3: A ¹ , A ² , A ⁴ , A ⁵ , B ¹ , B ² are single bonds, A ³ is methylene or alkylene having 2 to 6 carbon atoms, and a is 1.

Specific examples of Y ² are given below, but the present invention is not limited to these. In the following structure, D has the same definition as in formula (Y2-1).

The (containing) ratio of the repeating unit represented by the formula (2) is preferably 1 to 70 mol%, more preferably 5 to 50 mol of all repeating units contained in the polyamic acid ester as the component (A). %.
In the polyamic acid ester which is the component (A), a preferred ratio of the repeating unit represented by the formula (1) to the repeating unit represented by the formula (2) is 1:10 to 10: 1 in molar ratio. More preferably, it is 1: 6 to 6: 1. Moreover, in all the repeating units contained in the polyamic acid ester which is the component (A), the total of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is 15 mol% or more. More preferably, it is 30 mol% or more.

The polyamic acid ester as the component (A) may have a repeating unit other than the formula (1) and the formula (2). The structure of the repeating unit other than those represented by formula (1) and formula (2) is not particularly limited, but if a specific example is given, the repeating unit represented by the following formula (4) is preferable.

In formula (4), R ¹ and R ² have the same definition as in formula (1), and Y ³ represents a divalent organic group other than formula (Y1-1) and formula (Y2-1). The structure of Y ³ in the formula (4) is not particularly limited as long as it is a divalent organic group other than the formulas (Y1-1) and (Y2-1). Although the specific example of a preferable structure is shown below, this invention is not limited to these.

Of the above structures, (Y-5), (Y-10) to (Y-16), (Y-18), (Y-24) to (Y-29) and the like are particularly preferable.
The polyamic acid ester as the component (A) can be obtained by a known synthesis method. For example, a method of polycondensing a tetracarboxylic acid derivative component containing a compound represented by the following formula (1a) and a diamine component containing a compound represented by the following formulas (1b) and (2b), or A polyamic acid was obtained by addition polymerization of a tetracarboxylic dianhydride component containing a compound represented by the following formula (1a ′) and a diamine component containing a compound represented by the following formulas (1b) and (2b). The method of esterifying a carboxyl group later can be mentioned.

In the formula, R is a hydroxy group or a chlorine atom, R ¹ , R ² and Y ¹ have the same definition as in formula (1), and Y ² has the same definition as in formula (2).
In the liquid crystal aligning agent of the present invention, the molecular weight of the polyamic acid ester as the component (A) is not particularly limited, but is preferably 2,000 to 500,000 in weight average molecular weight, more preferably 5,000 to 300,000. More preferably, it is 10,000 to 100,000.

<Polyamic acid (B)>
The polyamic acid as the component (B) has a repeating unit represented by the following formula (3). In addition, the structure of Formula (3) contained in this polyamic acid may be one type or two or more types.

In the formula (3), X is a tetravalent organic group, Y is a divalent organic group, and R ⁶ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
The polyamic acid having a repeating unit represented by the above formula (3) includes, for example, at least one compound represented by the following formula (3a) and at least one compound represented by the following formula (3b): Can be obtained by condensation polymerization. Therefore, X in the formula (3) can include structures corresponding to all the compounds represented by the formula (3a). Similarly, Y and R ⁶ in formula (3) can include structures corresponding to all the compounds represented by formula (3b).

X, Y, and R ⁶ in Formula (3a) and Formula (3b) have the same definitions as in Formula (3).
Specific examples of preferred structures of X in formula (3) are shown below, but the present invention is not limited to these.

In the ^{(X-1), R 7} ~ R 10 are each independently hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
X in the formula (3) is preferably at least one selected from the group consisting of the above (X-1) to (X-14), and particularly preferably in the above (X-1), R ⁷ to Structures in which R ¹⁰ is all hydrogen atoms, (X-2), (X-3), (X-5), (X-6), (X-7), (X-8), (X-10) ), (X-11), and (X-14).

The structure of Y in formula (3) is not particularly limited as long as it is a divalent organic group. However, from the viewpoint of enhancing the flicker improvement effect immediately after driving the liquid crystal display element, Y is It is preferable that the repeating unit of formula (Y1-1) or formula (Y2-1) is not included.
More specifically, Y is preferably a divalent organic group selected from the group consisting of (i) to (iii) below.

(I) A structure represented by the following (c-1) or (c-2).
(Ii) A combination of structures selected from the following (c-1) to (c-4).
(Iii) A linking group selected from the following (d-1) to (d-3) is included in the middle of a combination of structures selected from the following (c-1) to (c-4).

In formula (c-1), R represents a hydrogen atom, a methyl group, or a carboxyl group.
In the above, the combination of structures selected from the group consisting of (c-1) to (c-4) may be a combination using a plurality of the same structures. Further, bonding groups selected from the group consisting of (d-1) to (d-3) are not adjacent to each other. The molecular weight of the divalent organic group selected from the group consisting of (i) to (iii) is more preferably 1000 or less. Specific examples of Y include (Y-1) to (Y-34), but the present invention is not limited to these. Among them, (Y-5), (Y-8), (Y-9), (Y-12), (Y-17), (Y-18) to (Y-20), or (Y-29) ) Particularly preferred.

In the liquid crystal aligning agent of the present invention, the molecular weight of the polyamic acid as the component (B) is preferably 2,000 to 500,000, more preferably 5,000 to 300,000 in weight average molecular weight, and still more preferably. 10,000 to 100,000.

<Liquid crystal aligning agent>
The mass (containing) ratio (polyamic acid ester / polyamic acid) of the polyamic acid ester (A) and the polyamic acid (B) contained in the liquid crystal aligning agent of the present invention is preferably 1/9 to 9/1, more preferably It is preferably 2/8 to 8/2.
The liquid crystal aligning agent of the present invention is preferably in the form of a solution containing a polyamic acid ester (A) and a polyamic acid (B). In this case, the total content of the polyamic acid ester (A) and the polyamic acid (B) can be appropriately changed by setting the thickness of the liquid crystal alignment film to be formed. From the point of forming, 0.5 mass% or more of the whole liquid crystal aligning agent is preferable, and 15 mass% or less is preferable from the point of the storage stability of a solution. In particular, 0.5 to 10% by mass is more preferable, and 1 to 10% by mass is particularly preferable.

The organic solvent contained in the liquid crystal aligning agent of this invention will not be specifically limited if the polymer component of a polyamic acid ester (A) and a polyamic acid (B) melt | dissolves uniformly. Specific examples thereof include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, And 2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropanamide and the like. it can. You may use these 1 type or in mixture of 2 or more types.
From the viewpoint of compatibility between the polyamic acid ester (A) and the polyamic acid (B) contained in the liquid crystal aligning agent of the present invention, the N-methyl-2-pyrrolidone content ratio is It is preferably 30 to 80% by mass with respect to the weight. 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.

The liquid crystal aligning agent of the present invention may contain, in addition to the organic solvent, a solvent for improving the coating film uniformity when the liquid crystal aligning agent is applied to the substrate. As such a solvent, a solvent having a surface tension lower than that of the organic solvent is generally used. Specific examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2 -Propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, butyl cellosolve acetate, di Propylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactic acid Isoamyl ester, and the like. Two types of these solvents may be used in combination.

The liquid crystal aligning agent of this invention may contain various additives, such as a silane coupling agent, a crosslinking agent, and an imidation promoter.
The silane coupling agent can be added for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate. Moreover, the silane coupling agent may be one kind or a combination of two or more kinds. The content of the silane coupling agent is preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the polymer component.

Specific examples of the silane coupling agent are listed below, but are not limited thereto. 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-phenylaminopropyltri Amine-based silane coupling agents such as methoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, 3-aminopropyldiethoxymethylsilane; vinyltrimethoxysilane, vinyltriethoxysilane, Vinyl-based silane coupling agents such as vinyltris (2-methoxyethoxy) silane, vinylmethyldimethoxysilane, vinyltriacetoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, p-styryltrimethoxysilane 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ) Epoxy silane coupling agents such as ethyltrimethoxysilane; 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane Methacrylic silane coupling agents such as 3-acryloxypropyltrimethoxysilane and other acrylic silane coupling agents; 3-ureidopropyltriethoxysilane and other ureido silane coupling agents; Sulfide-based silane coupling agents such as (3- (triethoxysilyl) propyl) disulfide and bis (3- (triethoxysilyl) propyl) tetrasulfide; 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, Mercapto silane coupling agents such as 3-octanoylthio-1-propyltriethoxysilane; Isocyanate silane coupling agents such as 3-isocyanatopropyltriethoxysilane and 3-isocyanatopropyltrimethoxysilane; Triethoxysilylbutyraldehyde Aldehyde-based silane coupling agents; carbamate-based silane coupling agents such as triethoxysilylpropylmethyl carbamate and (3-triethoxysilylpropyl) -t-butyl carbamate Agent.

The crosslinking agent can be used for the purpose of increasing the film strength of the liquid crystal alignment film. Moreover, one type of crosslinking agent may be sufficient and it may combine two or more types. The amount of the crosslinking agent used is preferably 0.1 to 50 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymer component.
The crosslinking agent is at least one selected from the group consisting of a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group, a cyclocarbonate group, or a hydroxyalkylamide group, a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. And a crosslinkable compound having a substituent, or a crosslinkable compound having a polymerizable unsaturated bond. It is preferable to have two or more of these substituents and polymerizable unsaturated bonds in the crosslinkable compound.

Specific examples of the crosslinking agent are listed below, but are not limited thereto. Examples of the crosslinkable compound having an epoxy group or an isocyanate group include bisphenolacetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, tetraglycidylaminodiphenylene, tetraglycidyl-m-xylenediamine, tetraglycidyl- 1,3-bis (aminoethyl) cyclohexane, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacetodiglycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy) -1- Trifluoromethyl-2,2,2-trifluoromethyl) benzene, 4,4-bis (2,3-epoxypropoxy) octafluorobiphenyl, triglyceride Zyl-p-aminophenol, tetraglycidylmetaxylenediamine, 2- (4- (2,3-epoxypropoxy) phenyl) -2- (4- (1,1-bis (4- (2,3-epoxypropoxy) ) Phenyl) ethyl) phenyl) propane, 1,3-bis (4- (1- (4- (2,3-epoxypropoxy) phenyl) -1- (4- (1- (4- (2,3- And epoxypropoxy) phenyl) -1-methylethyl) phenyl) ethyl) phenoxy) -2-propanol.

Examples of the crosslinkable compound having an oxetane group include crosslinkable compounds represented by the formulas [4a] to [4k] described on pages 58 to 59 of the pamphlet of International Publication No. WO2011 / 132751. Examples of the crosslinkable compound having a cyclocarbonate group include crosslinkable compounds represented by the formulas [5-1] to [5-42] described on pages 76 to 82 of WO 2012/014898 pamphlet. .
Examples of the crosslinkable compound having a hydroxyalkylamide group include the crosslinkable compounds described on page 23 [Chemical Formula 35] of the pamphlet of International Publication No. WO2015 / 072554. Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxyl group include those represented by formulas [6-1] to 6-66 of International Publication No. WO2011 / 132751. And a crosslinkable compound represented by [6-48].

Examples of the crosslinkable compound having a polymerizable unsaturated bond include the crosslinkable compounds described in [0112] to [0113] of pamphlet 58 to 59 of International Publication No. WO2015 / 060357.
The imidization accelerator can be used for the purpose of efficiently proceeding the imidization reaction of the polyamic acid ester (A) and the polyamic acid (B) when the coating film of the liquid crystal aligning agent of the present invention is baked. The amount of the imidization accelerator used is preferably 0.01 mol or more, more preferably 0.05 mol or more, and still more preferably 0.8 mol, per 1 mol of an amic acid site and an amic acid ester site capable of imidization reaction. 1 mole or more. In addition, from the viewpoint of minimizing the adverse effect of the imidization accelerator itself remaining in the film after firing on various properties of the liquid crystal alignment film, it is preferably 2 mol or less, more preferably 1 mol or less, still more preferably. Is 0.5 mol or less.
Specific examples of the imidization accelerator include compounds represented by formulas (B-1) to (B-17), which are listed on page 29 of International Publication WO2010 / 114103 pamphlet. It is not limited.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention is a liquid crystal alignment film obtained using the liquid crystal aligning agent of the present invention described above. A known method can be used to obtain the liquid crystal alignment film. For example, it is a liquid crystal alignment film provided with a liquid crystal alignment ability by applying a liquid crystal aligning agent to a substrate, drying and baking, and irradiating a coating film obtained by rubbing or polarizing ultraviolet rays.
The substrate on which the liquid crystal alignment agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. It is preferable to use a substrate on which an ITO electrode or the like is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used. Examples of the method for applying the liquid crystal aligning agent 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. Usually, in order to sufficiently remove the organic solvent contained, drying is performed at 50 to 120 ° C. for 1 to 10 minutes, and then baking is performed at 150 to 300 ° C. for 5 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 the method for aligning the coating film include a rubbing method and a photo-alignment processing method. The liquid crystal aligning agent of the present invention is particularly useful when used in the rubbing method.

<Liquid crystal display element>
The liquid crystal display element of this invention is a liquid crystal display element which has said liquid crystal aligning film. More specifically, after a substrate with a liquid crystal alignment film is obtained from the liquid crystal aligning agent of the present embodiment by the above-described method, a liquid crystal cell is produced by a known method to obtain a liquid crystal display element.
An example of liquid crystal cell fabrication is as follows. First, a pair of substrates on which a liquid crystal alignment film is formed are prepared. Next, after bonding the other substrate so that the liquid crystal alignment film surface is on the inside, the liquid crystal is injected under reduced pressure and sealed. Alternatively, after the liquid crystal is dropped on the liquid crystal alignment film surface, the substrate may be attached and sealed. At this time, in order to secure a space filled with a liquid crystal material between a pair of substrates, columnar protrusions are provided on one substrate, spacers are dispersed on one substrate, or spacers are mixed in a sealing material. It is preferable to take measures such as combining them. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm.

Examples of the liquid crystal material include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable, and either a positive liquid crystal material or a negative liquid crystal material may be used. Next, a polarizing plate is installed. Specifically, it is preferable to attach a pair of polarizing plates to the surfaces of the two substrates opposite to the liquid crystal layer.
In addition, the liquid crystal aligning film and liquid crystal display element of this invention are not limited to said description, The thing produced by the other well-known method may be used. Processes for obtaining a liquid crystal display element from a liquid crystal aligning agent are also disclosed in a number of documents in addition to, for example, page 17 [0074] to page 19 [0081] of Japanese Patent Application Laid-Open No. 2015-135393.

The present invention will be described more specifically with reference to the following examples. However, the present invention is not construed as being limited to these examples. The abbreviations of the compounds to be used hereinafter and the measuring methods of the respective characteristics are as follows.

<Abbreviation of compound>
In the following, “Boc” is a tert-butoxycarbonyl group.

<Abbreviation of solvent>
NMP: N-methyl-2-pyrrolidone, BCS: Butyl cellosolve GBL: γ-butyrolactone, IPA: Isopropyl alcohol <viscosity>
The viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a sample amount of 1.1 mL, cone rotor TE-1 (1 ° 34 ′, R24), and a temperature of 25 ° C. .

<Molecular weight>
The molecular weight of the polymer is measured by a GPC (normal temperature gel permeation chromatography) apparatus, and the number average molecular weight (hereinafter also referred to as Mn) and the weight average molecular weight (hereinafter also referred to as Mw) as polyethylene glycol and polyethylene oxide converted values. Calculated.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805), column temperature: 50 ° C.
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 ml / L), flow rate: 1.0 ml / min Standard sample for preparing calibration curve: TSK standard polyethylene oxide (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, manufactured by Tosoh Corporation 30,000) and polyethylene glycol manufactured by Polymer Laboratories (peak top molecular weight (Mp) of about 12,000, 4,000, 1,000). In order to avoid the overlapping of peaks, the measurement was performed by mixing four types of 900,000, 100,000, 12,000, and 1,000, and three types of 150,000, 30,000, and 4,000. Two samples of the mixed sample were measured separately.

<Rubbing resistance evaluation>
The liquid crystal aligning agent is filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried on an 80 ° C. hot plate for 5 minutes, and then baked at 230 ° C. for 20 minutes. A 100 nm polyimide film was obtained. This polyimide film was rubbed once with a rayon cloth (roll diameter 120 mm, rotation speed 1000 rpm, moving speed 20 mm / sec, pushing amount 0.4 mm). The surface of the film was observed using a confocal laser microscope, and was scraped at a magnification of 100 times to observe the presence of scraps and the presence of scratches. The evaluation was defined as “good” when the scraped scraps and scratches were hardly seen, and defined as “bad” when the scraped scraps and rubbing scratches were observed.

<Production of liquid crystal display element>
First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an IZO 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 IZO 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 the obtained liquid crystal aligning agent is filtered through a 1.0 μm filter, an ITO film is formed on the back surface as the prepared substrate with electrodes and a counter substrate, and a columnar spacer having a height of 4 μm. Each of the glass substrates having was spin-coated. Subsequently, after drying for 5 minutes on an 80 degreeC hotplate, it baked at 230 degreeC for 20 minutes, and obtained the polyimide film on each board | substrate as a 60 nm-thick coating film. The polyimide film is rubbed with a rayon cloth in a predetermined rubbing direction (roll diameter 120 mm, rotation speed 500 rpm, moving speed 30 mm / sec, pushing amount 0.3 mm), and then irradiated with ultrasonic waves in pure water for 1 minute. And dried at 80 ° C. for 10 minutes.

Then, using the two types of substrates with the liquid crystal alignment film, the rubbing directions are combined so that they are antiparallel, the periphery is sealed leaving the liquid crystal injection port, and an empty cell with a cell gap of 3.8 μm is formed. Produced. A liquid crystal (MLC-2041, manufactured by Merck & Co., Inc.) was vacuum-injected into this empty cell at room temperature, and the injection port was sealed to obtain an anti-parallel alignment liquid crystal cell. The obtained liquid crystal cell constitutes an FFS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heated at 120 ° C. for 1 hour and allowed to stand overnight before being used for each evaluation.

<Evaluation of relaxation characteristics of accumulated charge>
The afterimage was evaluated using the following optical system and the like. The prepared liquid crystal cell is installed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the LED backlight is turned on with no voltage applied, so that the brightness of transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted.
Next, a VT curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, and an AC voltage with a relative transmittance of 23% was calculated as a drive voltage.

In the afterimage evaluation, a DC voltage of 1 V was applied at the same time while driving the liquid crystal cell by applying an AC voltage having a relative transmittance of 23% and a frequency of 30 Hz, and driving was performed for 60 minutes. Thereafter, the applied DC voltage value was set to 0 V, and only the application of the DC voltage was stopped, and in that state, driving was continued for another 30 minutes.
The evaluation was defined as “good” when the relative transmittance dropped to 30% or less by the time 60 minutes passed from the start of application of the DC voltage. When it took 60 minutes or more for the relative transmittance to drop to 30% or less, it was defined as “bad” and evaluated.
And the afterimage evaluation according to the method mentioned above was performed on the temperature conditions of the state whose temperature of a liquid crystal cell is 23 degreeC.

<Stability evaluation of liquid crystal alignment>
Using this liquid crystal cell, an AC voltage of 10 VPP was applied at a frequency of 30 Hz in a constant temperature environment of 60 ° C. for 168 hours. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left as it was at room temperature for one day.
After leaving, the liquid crystal cell is placed between two polarizing plates arranged so that the polarization axes are orthogonal, and the backlight is turned on with no voltage applied so that the brightness of the transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the first pixel became darkest to the angle at which the first region became darkest was calculated as an angle Δ. Similarly, for the second pixel, the second area was compared with the first area, and a similar angle Δ was calculated. Then, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal cell. When the value of the angle Δ of the liquid crystal cell exceeded 0.2 degrees, it was defined as “defective” and evaluated. When the value of the angle Δ of the liquid crystal cell did not exceed 0.2 degrees, it was defined as “good” and evaluated.

<Evaluation of flicker level immediately after driving>
The afterimage was evaluated using the following optical system and the like.
The prepared liquid crystal cell is installed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the LED backlight is turned on with no voltage applied, so that the brightness of transmitted light is minimized. The arrangement angle of the liquid crystal cell was adjusted.
Next, a VT curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, and an AC voltage with a relative transmittance of 23% was calculated as a drive voltage.

In the measurement of the flicker level, the LED backlight that was turned on is temporarily turned off and left to block light for 72 hours, and then the LED backlight is turned on again. The frequency at which the relative transmittance becomes 23% at the same time when the backlight turns on is 30 Hz. The AC voltage was applied and the liquid crystal cell was driven for 60 minutes to track the flicker amplitude. The flicker amplitude is a data collection / data logger switch unit 34970A (Agilent technologies) that connects the transmitted light of the LED backlight that has passed through the two polarizing plates and the liquid crystal cell therebetween, via a photodiode and an IV conversion amplifier. ). The flicker level was calculated by the following formula.
Flicker level (%) = {flicker amplitude / (2 × z)} × 100

In the above formula, z is a value obtained by reading the luminance when driven by an AC voltage having a frequency of 30 Hz with a relative transmittance of 23% by the data collection / data logger switch unit 34970A.
The evaluation of the flicker level is defined as “good” when the flicker level is maintained at less than 3% by 60 minutes after the start of lighting of the LED backlight and application of the AC voltage. went. When the flicker level reached 3% or more in 60 minutes, it was defined as “bad” and evaluated.
The evaluation of the flicker level according to the above-described method was performed under temperature conditions where the temperature of the liquid crystal cell was 23 ° C.

<Evaluation of storage stability>
The storage stability was evaluated as “good” when the viscosity change of the following adjustment solution at room temperature storage for about 1 week was less than 5 mPa · s, and “bad” when the viscosity change was 5 mPa · s or more.

<Synthesis example>
(Synthesis Example 1)
After adding 119 g (0.46 mol) of CE-1 to a 7 L separable flask containing a stir bar, 2372 g of NMP was added and stirred to dissolve. Next, 146 g (1.44 mol) of triethylamine, 61 g (0.26 mol) of DA-1, 21 g (0.072 mol) of DA-3, and 49 g (0.14 mol) of DA-5 were added and stirred. Dissolved.
While stirring this solution under water cooling, 362 g (0.94 mol) of DBOP was added, 326 g of NMP was further added, and the mixture was stirred at room temperature for 12 hours to obtain a polyamic acid ester solution. The viscosity of this polyamic acid ester solution was 27.3 mPa · s.

This polyamic acid ester solution was put into 20739 g of IPA, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 100 ° C. to obtain a polyamic acid ester powder. The molecular weight of this polyamic acid ester was Mn = 12,200 and Mw = 21,700.
NMP was added to the obtained polyamic acid ester powder so as to have a solid content concentration of 12% by weight and dissolved by stirring at 50 ° C. for 30 hr to obtain a polyamic acid ester solution (PAE-1).

(Synthesis Example 2)
After adding 6.85 g (26.3 mmol) of CE-1 to a 300 mL four-necked flask containing a stir bar, 140 g of NMP was added and stirred to dissolve. Next, 8.5 g (84.0 mmol) of triethylamine, 4.10 g (16.8 mmol) of DA-2, and 3.82 g (11.2 mmol) of DA-5 were added and dissolved by stirring.
While stirring this solution under water cooling, 20.7 g (54.0 mmol) of DBOP was added, and 19.2 g of NMP was further added, followed by stirring at room temperature for 12 hours to obtain a polyamic acid ester solution. The viscosity of this polyamic acid ester solution was 31.4 mPa · s.
This polyamic acid ester solution was put into 1218 g of IPA, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 100 ° C. to obtain a polyamic acid ester powder. The molecular weight of this polyamic acid ester was Mn = 11,600 and Mw = 20,500.
NMP was added to the obtained polyamic acid ester powder so as to have a solid content concentration of 12% by weight, and the mixture was dissolved by stirring at 50 ° C. for 30 hours to obtain a polyamic acid ester solution (PAE-2).

(Synthesis Example 3)
In a 5 L separable flask equipped with a stirrer and a nitrogen introducing tube, 243.9 g (1.22 mol) of DA-4 and 74.8 g (0.31 mol) of DA-2 were taken, and a solvent (NMP: GBL = 50 wt%: 50 wt%) was added, and the mixture was stirred and dissolved while feeding nitrogen.
While stirring this diamine solution under water cooling, 129.0 g (0.66 mol) of CA-2 and 166.8 g (0.77 mol) of CA-1 were added, and the solid content concentration was further adjusted to 12% by weight. A solvent (NMP: GBL = 50 wt%: 50 wt%) was added and stirred at 50 ° C. for 12 hours to obtain a polyamic acid solution (PAA-1). The viscosity of this polyamic acid solution was 310 mPa · s. Moreover, it was Mn = 11,700 and Mw = 24,300 of this polyamic acid.

(Synthesis Example 4)
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 4.1 g (20.4 mmol) of DA-4, 5.4 g (13.6 mmol) of DA-6, and 8.3 g of DA-2 ( 34.0 mol), 173 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen.
While stirring this diamine solution under water cooling, 5.3 g (27.2 mmol) of CA-2 and 7.4 g (34.0 mmol) of CA-1 were added, and the solid content concentration was further adjusted to 15% by weight. NMP was added and stirred at 50 ° C. for 12 hours to obtain a polyamic acid solution (PAA-2). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 530 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 11,700 and Mw = 27,200.

Example 1
In a 20 ml sample tube containing a stir bar, 2.31 g of PAE-1 and 8.31 g of PAA-1 were taken, 1.31 g of NMP, 2.38 g of GBL, 4.0 g of BCS, and 1 AD-1 1.2 g of NMP solution containing wt% and 0.60 g of AD-2 were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-1).

(Example 2)
In a 20 ml sample tube containing a stir bar, 3.46 g of PAE-1 and 7.18 g of PAA-1 were taken, 0.73 g of NMP, 2.38 g of GBL, 4.0 g of BCS, and 1 AD-1 1.2 g of NMP solution containing wt% and 0.60 g of AD-2 were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-2).

(Example 3)
In a 20 ml sample tube containing a stir bar, 4.62 g of PAE-1 and 6.15 g of PAA-1 are taken, 0.15 g of NMP, 2.38 g of GBL, 4.0 g of BCS, and 1 AD-1. 1.2 g of NMP solution containing 5% by weight and 0.60 g of AD-2 were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (A-3).

(Comparative Example 1)
In a 20 ml sample tube containing a stir bar, 2.40 g of PAE-2, 6.88 g of PAA-2, 4.92 g of GBL, 4.0 g of BCS, and 1 wt% of AD-1 are added to an NMP solution. 1.2 g and 0.60 g of AD-2 were added and stirred with a magnetic stirrer for 30 minutes to obtain a liquid crystal aligning agent (B-1).
Using the liquid crystal aligning agent obtained above, the rubbing resistance, the accumulated charge relaxation characteristics, the stability of liquid crystal alignment, the flicker level immediately after driving, and the storage stability were evaluated. The results are shown in Table 1.

As described above, the liquid crystal alignment film of the present invention showed good results in any of evaluation of rubbing resistance, evaluation of afterimage erasing time, evaluation of stability of liquid crystal alignment, and evaluation of flicker level immediately after driving.

The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention can be used in a wide range of liquid crystal display elements including an IPS driving method and an FFS driving method, which are required to realize various characteristics at a higher level than before. .
The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2015-229489 filed on November 25, 2015 are cited here as disclosure of the specification of the present invention. Incorporate.

Claims

The liquid crystal aligning agent characterized by containing the following (A) component and (B) component.
(A) Component: Polyamic acid ester containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).
Component (B): a polyamic acid having a repeating unit represented by the following formula (3).

(In Formula (1) and Formula (2), a plurality of R 1 are each independently an alkyl group having 1 to 6 carbon atoms. A plurality of R 2 are each independently a hydrogen atom or a carbon number) And Y 1 is a divalent organic group represented by the following formula (Y1-1), and Y 2 is a divalent organic group represented by the following formula (Y2-1). Group.)

(In the formula (Y1-1), two R 3 s are each independently a single bond, —O—, —S—, —OCO—, or —COO—. The two R 4 s are each independently An alkylene group having 1 to 3 carbon atoms, and R 5 is an oxygen atom or a sulfur atom.)

(In Formula (Y2-1), A 1 and A 5 are each independently a single bond, methylene, alkylene having 2 to 5 carbon atoms, azetidinediyl, pyrrolidinediyl, or piperidinediyl. B 1 and B 2 are each independently a single bond, -O -, - COO -, - OCO -, - CONH -, - NHCO -, - CONCH 3 -, or -NCH 3 is CO- .A 2 and a 4 Each independently represents a single bond, methylene, or alkylene having 2 to 5 carbon atoms, A 3 is methylene or alkylene having 2 to 6 carbon atoms, a is 0 or 1, and R is a hydrogen atom. Alternatively, it is a methyl group, and D is a protecting group that is replaced with a hydrogen atom by heat.

(In formula (3), X is a tetravalent organic group, Y is a divalent organic group, and R 6 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)
The liquid crystal aligning agent according to claim 1, wherein the formula (Y1-1) is selected from the group consisting of the following (Y1-1-1) to (Y1-1-8).
In formula (Y2-1, A 1 , A 2 , A 4 , A 5 , B 1 , B 2 are single bonds, A 3 is methylene or alkylene having 2 to 6 carbon atoms, and a is 1 The liquid crystal aligning agent of Claim 1 or 2.
The liquid crystal alignment according to any one of claims 1 to 3, wherein Y in the formula (3) is a divalent organic group selected from the group consisting of the following (i), (iii) and (iii): Agent.
(I) A structure represented by the following (c-1) or (c-2).
(Ii) A combination of structures selected from the group consisting of the following (c-1) to (c-4).
(Iii) A linking group selected from the group consisting of the following (d-1) to (d-3) is included in the middle of a combination of structures selected from the group consisting of the following (c-1) to (c-4).

(In the formula (c-1), R represents a hydrogen atom, a methyl group, or a carboxyl group.)
The liquid crystal aligning agent according to claim 4, wherein in formula (3), X is at least one tetravalent organic group selected from the group consisting of the following (X-1) to (X-14).
The ratio of the repeating unit represented by the formula (1) or the ratio of the repeating unit represented by the formula (2) is 1 to 70 mol of all repeating units contained in the polyamic acid ester as the component (A). The liquid crystal aligning agent according to any one of claims 1 to 5, which is%.
In the polyamic acid ester of the component (A), the content ratio (molar ratio) between the repeating unit represented by the formula (1) and the repeating unit represented by the following formula (2) is 1:10 to 10: 1. The liquid crystal aligning agent according to any one of claims 1 to 6, wherein
The liquid crystal alignment according to any one of claims 1 to 7, wherein a total content of the component (A) and the component (B) is 0.5 to 15% by mass with respect to the entire liquid crystal aligning agent. Agent.
The mass content ratio of the component (A) and the component (B) is 1/9 to 9/1, and the component (B) is 100 to 400 mass with respect to 100 parts by mass of the component (A). The liquid crystal aligning agent according to any one of claims 1 to 8, which is contained in a part.
N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-vinyl- Claims containing an organic solvent selected from the group consisting of 2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N, N-dimethylpropanamide Item 10. The liquid crystal aligning agent according to any one of Items 1 to 9.
The liquid crystal aligning agent according to any one of claims 1 to 10, further comprising a silane coupling agent, a crosslinking agent, or a dosing accelerator.
A liquid crystal alignment film obtained by using the liquid crystal aligning agent according to any one of claims 1 to 11.
A liquid crystal display element having the liquid crystal alignment film according to claim 12.