WO2019103042A1

WO2019103042A1 - Liquid crystal aligning agent, liquid crystal alignment film, manufacturing method of liquid crystal alignment film, and liquid crystal display element

Info

Publication number: WO2019103042A1
Application number: PCT/JP2018/043005
Authority: WO
Inventors: 亮一芦澤; 一平福田; 直史長谷川; 美希豊田; 司藤枝
Original assignee: 日産化学株式会社
Priority date: 2017-11-21
Filing date: 2018-11-21
Publication date: 2019-05-31
Also published as: CN111386493B; KR20200079314A; CN111386493A; JPWO2019103042A1; TWI810224B; TW201936713A; JP7375544B2

Abstract

A liquid crystal aligning agent is provided which can suppress alignment film coating faults due to the influence of the wiring structure or contact holes, and which can suppress faults in which display of a liquid crystal display element becomes uneven; a liquid crystal alignment film and a liquid crystal display element are also provided. This liquid crystal aligning agent is characterized by containing: at least one polymer selected from the group consisting of a polyamic acid or a polyamic acid ester having the structure of formula [1] and a polyimide which is an imide compound thereof; and a solvent containing at least one solvent A selected from the group consisting of formulae (d-1) to (d-5), and at least one solvent B selected from a group consisting of formula (e), and alkylene glycol monoalkyl ether acetate, alkylene glycol diacetate, alkylene glycol monoalkyl ether and alkylene glycol dialkyl ether having a boiling point of 200-300°C. (The symbols in the formulae are as defined in the specification.)

Description

Liquid crystal alignment agent, liquid crystal alignment film, method of manufacturing liquid crystal alignment film, and liquid crystal display device

The present invention is a liquid crystal aligning agent having high dimensional stability when ink jet coating is applied and which is difficult to be dried during flexographic printing, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display device having the liquid crystal aligning film. About.

As a liquid crystal alignment film in a liquid crystal display element, a so-called polyimide-based liquid crystal alignment film is widely used which is obtained by applying and baking a liquid crystal alignment agent containing a polyimide precursor such as polyamic acid (polyamic acid) or a soluble polyimide solution as a main component It is done. As a film forming method of such a liquid crystal alignment film, spin coating, dip coating, flexographic printing and the like are generally known. In flexographic printing, although it is possible to easily form an alignment film pattern and have high productivity, in order to form a uniform thin film, it is necessary to apply a liquid crystal alignment agent to the surface of the anilox roll and the doctor roll. In order to prevent the drying of the alignment film material on the surface of the liquid crystal, it is necessary to supply a liquid crystal alignment agent at regular intervals (Patent Document 1). In addition, there is a problem that it is difficult to form an alignment film on a substrate having large unevenness or a substrate having a curved surface.

Therefore, an inkjet method is proposed as a coating method of another liquid crystal aligning agent instead of the above. The inkjet method is a method in which fine droplets are dropped on a substrate and a film is formed by wetting and spreading of a liquid. Since the printing pattern can be set freely, there is an advantage that it is possible to form an alignment film on a substrate with large unevenness and a substrate with a curved surface.

In the liquid crystal alignment film formed by the inkjet method, it is required that the film thickness unevenness in the coating surface is small and the film forming accuracy in the peripheral portion of the coating is high. In general, in the liquid crystal alignment film formed by the inkjet method, the uniformity of the film thickness in the coated surface and the film forming accuracy in the peripheral portion of the coating have a trade-off relationship. In general, a material having high in-plane uniformity has poor dimensional stability at the coating peripheral portion, and the film protrudes from the set dimension. On the other hand, in the material in which the coating peripheral portion becomes a straight line, the in-plane uniformity of the coating becomes worse.
In order to enhance the film formation accuracy in the peripheral portion of application, a method is proposed in which the liquid crystal alignment film is confined within a predetermined range by a structure (Patent Document 2, Patent Document 3, Patent Document 4). However, these methods have the disadvantage that additional structures are required.

Japanese Patent Application Publication No. 2001-042330 Japanese Patent Laid-Open No. 2004-361623 Japanese Patent Laid-Open No. 2008-145461 Japanese Unexamined Patent Publication No. 2010-281925

In recent years, TFTs with multilayer wiring are becoming mainstream as liquid crystal display elements are becoming higher definition. In this design TFT, in order to connect the lower layer wiring and the upper layer wiring, a contact hole (hereinafter also referred to as C / H) is formed on the TFT substrate. Along with this, when the liquid crystal aligning agent is applied by inkjet, the spreadability of the liquid is easily inhibited due to the influence of the wiring structure and C / H. As a result, the film thickness of the alignment film may be uneven around the C / H and other parts, such as dot-like unevenness and streak-like unevenness, and the display of the liquid crystal display may be uneven. Further, as the production line of the liquid crystal alignment film is enlarged, there is a problem that when the liquid crystal alignment agent is applied by flexographic printing, drying of the liquid crystal alignment agent on the surface of the anilox roll and the doctor roll is likely to occur. Furthermore, the requirement for quality improvement of a display element is more severe, and in particular, a liquid crystal alignment film having more properties than ever in liquid crystal alignment is required.

In view of the above problems, the present invention can suppress the coating failure of the alignment film generated due to the influence of the wiring structure or C / H, and can suppress the failure of the liquid crystal display element becoming nonuniform. It is to provide a liquid crystal alignment film and a liquid crystal display device using the same.
Another object of the present invention is to provide a liquid crystal aligning agent capable of suppressing the drying of the liquid crystal aligning agent generated when flexographic printing is performed, a liquid crystal aligning film using the same, and a method of manufacturing the liquid crystal aligning film. Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film having high liquid crystal alignment.

As a result of intensive studies to solve the above problems, the present inventors simultaneously improve various properties by combining a polymer having a specific structure and a solvent containing a specific solvent. The present invention has been completed.

The present invention is based on such findings and has the following gist.
At least one selected from the group consisting of a polyamic acid having a structure of the following formula [1], a polyamic acid ester (hereinafter, polyamic acid and polyamic acid ester are also generically referred to as a polyimide precursor), and polyimide which is an imidized product thereof. A polymer of the species,
Alkylene glycol monoalkyl ether acetate having at least one solvent A selected from the group consisting of the following formulas (d-1) to (d-5), and the following formula (e), and having a boiling point of 200 to 300 ° C. What is claimed is: 1. A liquid crystal aligning agent comprising: a solvent containing at least one solvent B selected from the group consisting of diacetates, alkylene glycol monoalkyl ethers, and alkylene glycol dialkyl ethers.

However, X is a single bond, -O-, -C (CH ₃ ) _2- , -NH-, -CO-, -NHCO-, -COO-,-(CH ₂ ) _m- , and -SO _2- And m represents an integer of 1 to 8; and a divalent organic group selected from the group consisting of Two Y's each independently represent a side chain structure selected from the group consisting of the following formulas [S1] to [S3] and a structure derived from tocopherol.

However, X ¹ and X ² are independently a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -COO-, -OCO-, or ((CH ₂ ) _a1 -A ₁ ) _m1- (a1 each independently represents an integer of 1 to 15, and A ₁ represents an oxygen atom -COO or OCO, m ₁ is 1 to 2). G ¹ and G ^{2 each} independently represent a divalent cyclic group selected from the group consisting of a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms, Any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or It may be substituted by a fluorine atom, and m and n are independently an integer of 0 to 3, and the sum thereof is 1 to 4. R ¹ is alkyl having 1 to 20 carbons, alkoxy having 1 to 20 carbons, or alkoxyalkyl having 2 to 20 carbons, and any hydrogen in these groups may be replaced by fluorine.
X ³ represents a single bond, -CONH-, -NHCO-, -CON (CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO- or OCO-, and R ² represents carbon The alkyl is an alkyl of 1 to 20 or an alkoxyalkyl of 2 to 20 carbons, and any hydrogen in these groups may be replaced by fluorine.
X ⁴ represents —CONH—, —NHCO—, —O—, —COO— or OCO—, and R ³ represents a structure having a steroid skeleton.

However, R _1a represents a monovalent hydrocarbon group having 2 to 8 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group. R _2a and R _2b independently represent an alkyl group having 1 to 6 carbon atoms. R _3a represents a methyl group or an ethyl group. R _5a represents an alkyl group having 1 to 6 carbon atoms. R _5b and R _5c independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds of the hydrocarbon group. Show. n is 1 or 2;

However, r _1a and r _1b independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and m is an integer of 2 to 6.

According to the liquid crystal aligning agent of the present invention, the coating failure of the alignment film caused by the influence of the wiring structure and C / H can be suppressed, the failure that the display of the liquid crystal display element becomes uneven can be suppressed, and the flexo printing is performed. Drying of the liquid crystal aligning agent is also suppressed at the same time. A liquid crystal alignment film having higher liquid crystal alignment can be obtained.

The liquid crystal aligning agent of the present invention comprises at least one polymer (hereinafter also referred to as a specific polymer) selected from the group consisting of a polyimide precursor having the structure of the above formula [1] and a polyimide which is an imidized product thereof. contains.

<Specific polymer>
Among them, the specific polymer preferably has the structure of the formula [1] in the main chain of the polymer from the viewpoint of easiness of synthesis. Here, in the present invention, the main chain of the polymer refers to a portion consisting of a chain of the longest atoms in the polymer. Further, in the specific polymer, the presence of the structure of the above-mentioned formula [1] in a portion other than the main chain (for example, a portion of the side chain of the polymer) is not excluded.
X in the formula [1] in a single _{_{bond, -O -, - C (CH}} 3) 2 -, - NH -, - CO -, - NHCO -, - COO -, - (CH 2) m -, It represents a divalent organic group consisting of —SO ₂ — or a combination thereof, and m represents an integer of 1 to 8.

The above examples of combinations _{_{_{_{thereof, -O- (CH 2) m -O}}}} -, - O-C (CH 3) 2 -, - CO- (CH 2) m -, - NH- (CH 2) m - And -SO _2- (CH ₂ ) _m- , -CONH- (CH ₂ ) _m- , -CONH- (CH ₂ ) _m -NHCO-, -COO- (CH ₂ ) _m -OCO- and the like.
X is preferably a single bond, -O-, -NH- or -O- (CH ₂ ) _m -O-.

Y in the formula [1] has a side chain structure selected from the following formulas [S1] to [S3] or a structure having a tocopherol skeleton.

In the formula [S1], X ¹ and X ² are as defined above. Among them, from the viewpoint of availability of raw materials and easiness of synthesis, a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 15), -O- or -CH ₂ O- Or COO- is preferred. More preferably, it is a single bond,-(CH ₂ ) _a- (a is an integer of 1 to 10), -O-, -CH ₂ O- or COO-.

G ¹ and G ² are as defined above.
Examples of the divalent aromatic group having 6 to 12 carbon atoms include phenylene, biphenylene and naphthalene. Further, examples of the divalent alicyclic group having 3 to 8 carbon atoms include cyclopropylene and cyclohexylene.

As preferred specific examples of the formula [S1], structures of the following formulas [S1-x1] to [S1-x7] can be mentioned.

However, R ¹ is an alkyl group having 1 to 20 carbon atoms, and X ^p is — (CH ₂ ) _a — (a is an integer of 1 to 15), —CONH—, —NHCO—, —CON ( CH ₃ ) —, —NH—, —O—, —CH ₂ O—, —CH ₂ OCO—, —COO—, or —OCO—. A ₁ is an oxygen atom or -COO- * (wherein the bond attached with "*" is bonded to (CH ₂ ) a ₂ ), A ₂ is an oxygen atom or * -COO- ("*" The bond is (CH ₂ ) _a2 ). a ₁ and a ₃ are independently an integer of 0 or 1, a ₂ is an integer of 1 to 10, and Cy is a 1,4-cyclohexylene group or a 1,4-phenylene group.

In formula [S2], X ³ is a group as defined above. Among them, -CONH-, -NHCO-, -O-, -CH ₂ O-, -COO- or OCO- is preferable from the viewpoint of liquid crystal alignment.
R ² is as defined above. Among them, alkyl having 3 to 20 carbons or alkoxyalkyl having 2 to 20 carbons is preferable from the viewpoint of liquid crystal alignment.
As preferred specific examples of the formula [S2], -CONH- (CH ₂ ) _n -CH ₃ (n = 2 to 17), -NHCO- (CH ₂ ) _n -CH ₃ (n = 2 to 17), -O -(CH ₂ ) _n -CH ₃ (n = 2 to 17), -COO- (CH ₂ ) _n -CH ₃ (n = 2 to 17), -CH ₂ O- (CH ₂ ) _n -CH ₃ ( n = 2 to 17).

In formula [S3], X ⁴ is a group as defined above. Among them, -O-, -COO- or -OCO- is preferable from the viewpoint of liquid crystal alignment.
As a structure having a steroid skeleton, a structure in which a hydroxy group is removed from a compound such as β-sitosterol or ergosterol, a structure in which a hydroxy group is removed from a steroid compound described in [0024] of JP-A-4-281427, [0030] ] The structure which removed the acid chloride group from the steroid compound as described in, the structure which remove | eliminated the amino group from the steroid compound as described in [0038], the structure as which the halogen group was remove | excluded from the steroid compound, The structures described in [0018] to [0022] of -146421 can be mentioned.

The following formula [S3-x] is given as a preferred specific example of the formula [S3]. The definitions of X, Col and G in the formula [S3-x] are as follows, respectively.

(In the formula, * indicates a bonding position)

As more preferable examples of the formula [S3], structures represented by the following formulas [S3-1] to [S3-6] can be given.

(In the formula, * indicates a bonding position)

Examples of the structure having a tocopherol skeleton in the formula [1] include structures derived from compounds such as α-tocopherol, β-tocopherol, γ-tocopherol and δ-tocopherol. As a specific example of the structure which has the said tocopherol frame | skeleton, the structure shown by following formula [T] can be mentioned, for example. In addition, "*" shows a coupling | bonding position.

The specific polymer contained in the liquid crystal aligning agent of the present invention is a group consisting of a polyimide precursor having a divalent group represented by the above formula [1] and a polyimide which is an imidized product of the polyimide precursor. As long as it is at least 1 or more types of polymers chosen from, it may be synthesize | combined by what kind of method.
Among them, the specific polymer is a tetracarboxylic acid having the structure of the formula [1] or a derivative thereof (hereinafter, also referred to as a specific tetracarboxylic acid compound), or a tetracarboxylic acid containing the specific tetracarboxylic acid compound A polyimide precursor obtained by reacting a component and a diamine component; a polyimide of the polyimide precursor; a tetracarboxylic acid component, and a diamine having a structure of the formula [1] (hereinafter referred to as "specific diamine") Or a polyimide precursor obtained by reacting a diamine component containing a specific diamine; and one or more selected from the group consisting of the polyimide of the polyimide precursor.

[Tetracarboxylic acid component]
The tetracarboxylic acid component used to synthesize the specific polymer contains either or both of the specific tetracarboxylic acid compound or the other tetracarboxylic acid compound.
<Specific tetracarboxylic acid compound>
The specific tetracarboxylic acid compound is a tetracarboxylic acid compound having a structure of the above formula [1], and examples thereof include a compound represented by the formula [T] or a derivative thereof.

In formula [T], A represents a trivalent group, and two A may be the same or different. Examples of A include a trivalent organic group having at least one selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, a cyclohexane ring structure, a benzene ring structure and the following formula (A-1). P represents a divalent organic group having the structure of the above formula [1].

Examples of the derivative of the tetracarboxylic acid compound include tetracarboxylic acid dianhydride, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester or tetracarboxylic acid dialkyl ester dihalide.

<Other tetracarboxylic acid compounds>
Other tetracarboxylic acid compounds include 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3, 3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ', 4,4'-benzophenone Tetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,1 3,3,3-Hexafluoro-2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxylic acid) Ruboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis (3,4-dicarboxyphenyl) pyridine, 3,3 ', 4,4'-diphenyl sulfone tetracarboxylic acid Acid dianhydride obtained from tetracarboxylic acid such as acid, 3,4,9,10-perylenetetracarboxylic acid or 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, ] The tetracarboxylic acid dianhydride shown by these, or its derivative tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester compound, or tetracarboxylic acid dialkyl ester dihalide can be mentioned.

Among these, from the viewpoint of high solubility of the polymer, at least one or more of tetracarboxylic dianhydride having a structure represented by the formula [4] and its tetracarboxylic acid derivative are preferable.

Z represents a structure selected from the group consisting of the following [4a] to [4k].

(Wherein * 1 is a bond to be bonded to one acid anhydride group, and * 2 is a bond to be bonded to the other acid anhydride group).

In the formula [4a], Z ¹ to Z ⁴ independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring. Preferred specific examples of Z ¹ to Z ⁴ include the following formulas [4a-1] and [4a-2].

(* 1 and * 2 are as defined above.)

Wherein [4g], ^{Z 5} and ^{Z 6} are independently a hydrogen atom or a methyl group.
Among Z in the formula [4], in view of easiness of synthesis and easiness of polymerization reactivity at the time of producing a polymer, formula [4a], formula [4c] to formula [4 g] or formula [4] 4k] is preferred. Formula [4a] or Formula [4e] to Formula [4g] are more preferable, and [4a], Formula [4e] or Formula [4f] is particularly preferable. Preferred examples thereof include tetracarboxylic acid dianhydrides of structures shown by [4a-1], formulas [4a-2], formulas [4e] and formulas [4f] or their tetracarboxylic acid derivatives.

The tetracarboxylic acid compound represented by the formula [4] in the polymer of the present invention is preferably 1 mol% or more in 100 mol% of all tetracarboxylic acid compounds from the viewpoint of enhancing the solubility of the polymer. Among them, 5 mol% or more is preferable, and 10 mol% or more is more preferable.
The tetracarboxylic acid compound is selected depending on the solubility of the polymer of the present invention in the solvent, the coating property of the liquid crystal aligning agent, and the liquid crystal alignment property in the liquid crystal aligning film, the voltage holding ratio, and the accumulated charge. One kind or two or more kinds can be mixed and used.

[Diamine component]
The diamine component used to synthesize a specific polymer contains a specific diamine. A specific diamine is a diamine which has a structure of said Formula [1], for example, the compound represented by following formula [2] is mentioned.

<Specific diamine>
The specific diamine used for the liquid crystal aligning agent of this invention is represented by following formula [2].

Each of X and Y in the formula [2] has the same meaning as in the above-mentioned formula [1].
X is preferably a single bond, -O-, -NH- or -O- (CH ₂ ) _m -O- from the viewpoint of easy synthesis of the specific diamine. m is an integer of 1 to 8;

In formula [2], Y may be a meta position or an ortho position from the position of X, but is preferably an ortho position from the viewpoint of high reactivity of a specific diamine. Specifically, it is preferable that Formula [2] is the following Formula [2 '].

The above formula [2] is preferably a structure of any of the following formulas from the viewpoint of high reactivity of the specific diamine, and a structure represented by the formula [2] -a1-1 is more preferred.

As a preferable form of Y in the said Formula [2], the preferable form of Y in said Formula [1] can be applied. Among them, from the viewpoint of enhancing the liquid crystal alignment, a structure selected from the formulas [S1-x3] to [S1-x4], [S1-x6] and the formula [S3-x] is preferable, and the following formula is preferred as a preferred example The structures of [W-1] to [W-6] can be mentioned.

In the formula, X ^p1 to X ^p8 are independently-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )-, -NH -, -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. X ^s1 to X ^s4 independently represent -O-, -COO- or -OCO-. X _a to X _f independently represent a single bond, -O-, -NH-, or -O- (CH ₂ ) _m -O-. R ^1a to R ^1h independently represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. m is an integer of 1 to 8;

Specific diamines are 1 according to the ink jet coatability of the liquid crystal alignment agent, the liquid crystal alignment when used as a liquid crystal alignment film, voltage holding characteristics, characteristics such as accumulated charge, and the response speed of liquid crystal when used as a liquid crystal display element. The species or two or more species can be mixed and used.
The specific diamine is preferably used in an amount of 1 to 100% by mole, more preferably 2 to 100% by mole, and particularly preferably 5 to 90% by mole, of the diamine component used for the synthesis of the specific polymer.

As a diamine for synthesizing a polyamic acid or a polyamic acid ester, only a specific diamine may be used, or other diamine may be used in combination with the specific diamine. Here, as the other diamine, for example, a diamine having a pretilt angle developing property other than the above (2), a diamine having a function of generating polymerization or radical upon irradiation with light, WO [WO 46/2015] [0169 ], Diamine having a carboxyl group or a hydroxyl group as described in [0171] to [0172], diamine having a nitrogen-containing heterocycle as described in [0173] to [0188], JP-A-2016-218149 Diamine having the nitrogen-containing structure described in [0050], 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, 1,3-bis (4-aminobutyl) And organosiloxane-containing diamines such as -1,1,3,3-tetramethyldisiloxane. Among them, in a liquid crystal display element of a PSA (Polymer Sustained Alignment) system, a diamine having a function of generating polymerization or generating a radical by light irradiation is preferable from the viewpoint of enhancing the response speed.

Preferred specific examples of other diamines include m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-difluoro-4 4,4'-Diaminobiphenyl, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl) amine, 4,4'- Diaminobenzophenone, 1,4-diaminonaphthalene, 2,6-diaminonaphthalene, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4 -Aminophenyl) butane, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (4-amino) Phenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1 1,4-phenylenebis (methylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, N, N '-(1,4-phenylene) bis (4-aminobenzamido), N, N'-bis (4-aminophenyl) terephthalamide, N, N'-bis (4-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 2,2′-bis [4- (4-aminophenoxy) ) Phenyl] propane, 2,2'-bis (4-aminophenyl) propane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1, 9-bis (4-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, bis (4-aminocyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5- Diaminopentane, 1,6-diaminohexane, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diamino Phenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-Diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4, 4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid, 2,6 -Diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diamide Carbazole, 1,4-bis- (4-aminophenyl) -piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N ' -Bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, the following formula (D-2-1) to formula (D-2-8) A compound represented by each of

Furthermore, the diamine whose these amino groups are secondary amino groups is mentioned.

Examples of the diamine having a pretilt angle developing property other than the above formula (2) include diamines represented by the structural formulas of the following formulas [V-1] to [V-7].

In the above formulae, X ^v1 to X ^v4 are independently-(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH ₃ )-,- _{NH -, - O -, -} CH 2 O -, - CH 2 OCO -, - COO-, or -OCO- shows a. X ^v5 represents -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. X ^V6 to X ^V7 independently represent -O-, -COO- or -OCO-.

Examples of the diamine having a function of polymerizing by light irradiation include diamines in which the structures represented by the following formulas [p1] to [p7] are directly or linked to an aromatic ring such as a benzene ring via a linking group. Be

Specific examples thereof include diamines represented by the following formula [Pa] or [P-b].

Although the bonding position of the two amino groups (-NH ₂ ) in the formula [Pa] and the formula [P-b] is not limited, from the viewpoint of the reactivity of the diamine, the positions 2, 4 and 5, 2, 5 Or the positions of 3, 5 are preferred. In consideration of the ease of synthesis of the diamine, the positions 2, 4 or 3, 5 are more preferable.
In the formula [Pa], R ⁸ is a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N (CH ₃ _{) -, - CON (CH 3} ) -, or -N _(CH 3) shows a CO-. A single bond, -O-, -COO-, -NHCO-, or -CONH- is preferable from the easiness of synthesis.

R ⁹ represents a single bond, an alkylene group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, a divalent group selected from an aromatic ring having 6 to 12 carbon atoms such as a benzene ring and a naphthalene ring, and cyclohexane Ring or other divalent alicyclic group having 3 to 8 carbon atoms, such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran, thiophene, etc. And a divalent cyclic group selected from the heterocycles of Here, the —CH ₂ — of the alkylene group may be optionally substituted by —CF ₂ — or —CH = CH—. From the ease of synthesis, a single bond or an alkylene group having 1 to 12 carbon atoms is preferred. k is an integer of 0 to 4;
R ¹⁰ represents a structure selected from the group consisting of the above formulas [p1] to [p7]. From the viewpoint of photoreactivity, [p1], [p2] and [p4] are preferable.

In the formula [P-b], Y ₁ and Y ₃ independently represent -CH _2- , -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, or -CO -Indicates. Y ₂ and Y ₅ are independently synonymous with R ₉ in the above [Pa]. Y ₄ represents a cinnamoyl group. Y ₆ represents a structure selected from the group consisting of the above formulas [p1] to [p7]. From the viewpoint of photoreactivity, [p1], [p2], or [p4] is preferable. m is 0 or 1;

The diamine having a function of polymerizing by light irradiation is determined according to the liquid crystal alignment property when formed into a liquid crystal alignment film, the pretilt angle, the voltage holding property, the characteristics such as accumulated charge, and the response speed of the liquid crystal when formed into a liquid crystal display element. , 1 type, or 2 or more types can be mixed and used.
It is preferable to use 10 to 70% by mole, more preferably 10 to 60% by mole, and particularly preferably 10 to 50% by mole of the diamine component used for the synthesis of the specific polymer, as the diamine having a function of polymerizing by light irradiation. is there.

Examples of diamines having a function of generating radicals by light irradiation include diamines having a moiety having a radical generating structure which is decomposed by ultraviolet irradiation to generate radicals in the side chain, for example, diamines represented by the following formula (R) It can be mentioned.

Ar, R ₁ , R ₂ , T ₁ , T ₂ , S and Q in the above formula (R) have the following definitions.
That is, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, to which an organic group may be substituted, and a hydrogen atom may be substituted by a halogen atom.
R ₁ and R ₂ are independently an alkyl group having 1 to 10 carbon atoms or an alkoxy group.
T _1, _{T 2} are independently a single bond or -O -, - COO -, - OCO -, - NHCO -, - CONH -, - NH -, - CH 2 O -, - N (CH 3) - And -CON (CH ₃ )-or -N (CH ₃ ) CO-.
S is the same as R ⁹ in the above [Pa].

Q is a structure selected from the group consisting of the following formulas [q-1] to [q-4] (R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₃ represents -CH _2- , -NR -, -O-, or -S- is shown.

(In the formula, * indicates a bonding position.)

In the above-mentioned formula (R), Ar having carbonyl bonded thereto is preferably a structure having a long conjugation length such as naphthylene or biphenylene from the viewpoint of efficiently absorbing the ultraviolet light. Ar may have a substituent, and such a substituent is preferably an electron donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group or an amino group. If the wavelength of ultraviolet light is in the range of 250 to 380 nm, sufficient characteristics can be obtained even with a phenyl group, so a phenyl group is most preferable.
R ₁ and R _{2 each} independently represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group, a benzyl group, or a phenethyl group, and in the case of an alkyl group or an alkoxy group, a ring is formed by R ₁ or R ₂ You may form.

From the viewpoint of easily producing a specific polymer, Q is more preferably a hydroxyl group or an alkoxyl group.
The diaminobenzene in the formula (R) may be any of o-phenylenediamine, m-phenylenediamine or p-phenylenediamine, but m-phenylenediamine or p in view of high reactivity with the tetracarboxylic acid component. Phenylenediamine is preferred.

Specifically, structures represented by the following formulas [R-1] to [R-4] are most preferable in terms of easiness of synthesis, high degree of versatility, and properties. In the formula, n is an integer of 2 to 8.

It is preferable to use 5 to 70 mol% of the diamine component used for the synthesis of the specific polymer, and more preferably 10 to 60 mol% from the viewpoint of maintaining liquid crystal alignment, as the diamine having the function of generating radicals upon light irradiation. And particularly preferably 10 to 50 mol%.

<Synthesis of specified polymer>
The specific polymer is obtained by reacting a diamine and a tetracarboxylic acid compound as described above. As a method of obtaining a polyamic acid, a method of polycondensation of tetracarboxylic acid dianhydride and diamine to obtain a polyamic acid or a method of polycondensation of a tetracarboxylic acid dihalide compound and a diamine compound to obtain a polyamic acid can be mentioned. .

The specific polymer can be obtained by reacting with a molecular weight modifier as needed. Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamines such as aniline, cyclohexylamine and n-butylamine, and monoisocyanates such as phenyl isocyanate and naphthyl isocyanate. be able to. The use ratio of the molecular weight modifier is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total of the tetracarboxylic acid compound and diamine used.

As a method of obtaining a polyamic acid ester, a method of polycondensing a diamine with a tetracarboxylic acid dialkyl ester compound in which a carboxylic acid group is dialkylesterified, a tetracarboxylic acid dialkyl ester dihalide in which a carboxylic acid group is dialkylesterified and dihalified. Examples thereof include a method of polycondensation of a compound and a primary or secondary diamine or a method of converting a carboxyl group of a polyamic acid into an ester.

As a method of obtaining a polyimide, the method of making said polyimide precursor ring-closing and making it a polyimide is mentioned.
The reaction of the diamine with the tetracarboxylic acid compound is preferably carried out in a solvent. The solvent is not particularly limited as long as it can dissolve the produced polymer. Specific examples of the solvent are listed below, but are not limited to these examples.

For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl-2-imidazolidinone Can be mentioned. Further, when the solvent solubility of the polymer is high, it is represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formulas [D-1] to [D-3] Solvents can be used.

(In the formula [D-1], D ¹ represents an alkylene group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkylene group having 1 to 3 carbon atoms; In the above, D ³ represents an alkylene group having 1 to 4 carbon atoms).

These solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polymer, it may be mixed and used for the said solvent in the range which the produced | generated polymer does not precipitate. In addition, since water in the solvent inhibits the polymerization reaction and causes hydrolysis of the formed polymer, it is preferable to use the solvent which has been dehydrated and dried.
When the diamine and the tetracarboxylic acid compound are reacted in a solvent, the reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a polymer of high molecular weight, and the concentration is too high And the viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial reaction may be performed at high concentration, and then solvent may be added.

In the polycondensation reaction, the ratio of the total number of moles of diamine to the total number of moles of the tetracarboxylic acid compound is preferably 0.8 to 1.2. Similar to a normal polycondensation reaction, the molecular weight of the specific polymer to be produced increases as the molar ratio approaches 1.0.
The polyimide is a polyimide obtained by ring-closing the polyimide precursor, and in this polyimide, the ring-closing rate (also referred to as imidation rate) of the amic acid group does not necessarily have to be 100%, depending on the application and purpose. It can be adjusted arbitrarily.

Examples of the method for imidizing the polyimide precursor include thermal imidization in which the solution of the polyimide precursor is heated as it is, or catalytic imidization in which the catalyst is added to the solution of the polyimide precursor.
The temperature for thermally imidizing the polyimide precursor in a solution is 100 to 400 ° C., preferably 120 to 250 ° C., and it is preferable to carry out while removing water generated by the imidization reaction out of the system.

Catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at -20 ° C to 250 ° C, preferably 0 to 180 ° C. . The amount of basic catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, of the amic acid group, and the amount of acid anhydride is 1 to 50 moles, preferably 3 to 30 moles of the amic acid group. It is a double. The basic catalyst may, for example, be pyridine, triethylamine, trimethylamine, tributylamine or trioctylamine. Among them, pyridine is preferable because it has a suitable basicity to allow the reaction to proceed. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like can be mentioned, and it is particularly preferable to use acetic anhydride because purification after completion of the reaction becomes easy. The imidation ratio by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature and reaction time.

When the produced polyimide precursor or polyimide is recovered from the reaction solution of the polyimide precursor or polyimide, the reaction solution may be introduced into a solvent and precipitated. As a solvent used for precipitation, methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water and the like can be mentioned. The polymer precipitated by charging in a solvent may be recovered by filtration and then dried at normal temperature or under heating under normal pressure or reduced pressure. In addition, when the precipitated and recovered polymer is redissolved in a solvent and the operation for reprecipitating and recovering is repeated twice to 10 times, impurities in the polymer can be reduced. As the solvent in this case, for example, alcohols, ketones, hydrocarbons and the like can be mentioned, and it is preferable to use three or more solvents selected from these, since the efficiency of purification is further improved.

The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polyimide precursor and the polyimide is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. It is. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, good orientation of the liquid crystal display element can be secured.

<Liquid crystal alignment agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving, in a solvent, at least one polymer selected from the group consisting of a polyimide precursor as described above and a polyimide and optionally added components used as needed. .
The solvent used for the liquid crystal aligning agent of the present invention is, as described above, at least one solvent A selected from the group consisting of the above formulas (d-1) to (d-5), the above formula (e), a boiling point And at least one solvent B selected from the group consisting of alkylene glycol monoalkyl ether acetate, alkylene glycol diacetate, alkylene glycol monoalkyl ether, and alkylene glycol dialkyl ether. In the present invention, the boiling point means the boiling point at 1 atm.
By containing the solvent A, the drying of the liquid crystal aligning agent is suppressed, so that the concentration change at the time of applying the liquid crystal aligning agent is suppressed, and a liquid crystal aligning agent having excellent coatability can be obtained. In addition, the solubility of the polymer in the solvent is also high, and it is possible to suppress the phenomenon that the precipitation of the polymer occurs at the time of firing and the film thickness becomes uneven. By containing the solvent B, the difference in boiling point from the solvent A becomes small, and the liquid crystal aligning agent can be spread by wetting when baking the coated substrate of the liquid crystal aligning agent, and therefore, for a substrate having a complicated step structure. Even in the case, it becomes possible to apply uniformly, and it is possible to obtain a liquid crystal alignment film excellent in uniformity of film thickness.

In Formula (d-1), examples of the monovalent hydrocarbon group having 2 to 8 carbon atoms as R _1a include a chain hydrocarbon group and an alicyclic hydrocarbon group, and examples thereof include a chain having 2 to 8 carbon atoms. Examples thereof include an alkyl group and a cycloalkyl group having 3 to 8 carbon atoms. Further, examples of the monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group include, for example, an alkoxyalkyl group having 2 to 8 carbon atoms.
Specific examples thereof include, as the chained alkyl group having 2 to 8 carbon atoms, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and the like. Examples of the cycloalkyl group having 3 to 8 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group. Examples of the alkoxyalkyl group having 2 to 8 carbon atoms include a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxybutyl group, an ethoxymethyl group and an ethoxyethyl group. These groups may be linear or branched.

In the formulas (d-2), (d-5) and the formula (e), examples of the alkyl group having 1 to 6 carbon atoms as R _2a , R _2b , R _5a , r _1a and r _1b include methyl and ethyl And a propyl group, a butyl group, a pentyl group, a hexyl group and the like, which may be linear or branched.
In formula (d-3), R _3a represents a methyl group or an ethyl group.
In the formula (d-5), examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms of R _5b and R _5c include a chain hydrocarbon group and an alicyclic hydrocarbon group, and examples thereof include 1 to 6 carbon atoms And a linear alkyl group, a cycloalkyl group having 3 to 6 carbon atoms, and the like. The monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group includes, for example, an alkoxyalkyl group having 1 to 6 carbon atoms. As specific examples of these, as a linear alkyl group having 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like can be mentioned; And cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and the like.

Specific examples of formula (d-1) include N-ethyl-2-pyrrolidone, N- (n-propyl) -2-pyrrolidone, N-isopropyl-2-pyrrolidone, N- (n-butyl) -2- Pyrrolidone, N- (tert-butyl) -2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N- (n-hexyl) -2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N- (n And -octyl) -2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone and the like. Among these, N-ethyl-2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N- (t-butyl) -2-pyrrolidone, N- (n Particular preference is given to using -butyl) -2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N- (n-hexyl) -2-pyrrolidone and N-methoxypropyl-2-pyrrolidone.

Specific examples of the formula (d-2) include 1,3-dimethyl-2-imidazolidinone (DMI), 1,3-diethyl-2-imidazolidinone and 1,3-dipropyl-2-imidazolidinone And 1,3-diisopropyl-2-imidazolidinone. Among them, DMI is preferred from the viewpoint of the solubility of the specific polymer.
Specific examples of the formula (d-5) include 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, iso Propoxy-N-isopropyl-propionamide, n-butoxy-N-isopropyl-propionamide and the like. Among these, 3-butoxy-N, N-dimethylpropanamide and 3-methoxy-N, N-dimethylpropanamide are preferable from the viewpoint of the solubility of the specific polymer and the like.

Among the solvents A, N-ethyl-2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N- (n-hexyl) from the viewpoint of solubility of a specific polymer ) -2-Pyrrolidone, N-methoxypropyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, 3-butoxy-N, N- At least one selected from the group consisting of dimethylpropanamide and 3-methoxy-N, N-dimethylpropanamide is preferred.
The content ratio of the solvent A in the solvent is preferably 5 to 99% by mass, and more preferably 10 to 99% by mass, with respect to the entire solvent contained in the liquid crystal aligning agent.

Specific examples of the formula (e) include ethylene carbonate, propylene carbonate, butylene carbonate, pentylene carbonate, hexylene carbonate, 2-methyl-1,3-propylene carbonate, and 2,2-dimethyl-1,3-propylene carbonate Etc. Among these, propylene carbonate, ethylene carbonate and butylene carbonate are preferable from the viewpoint of the solubility of the specific polymer and the like.
Specific examples of the alkylene glycol monoalkyl ether acetate having a boiling point of 200 to 300 ° C. include diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate and the like.

Specific examples of the alkylene glycol diacetate having a boiling point of 200 to 300 ° C. include 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, 1,2-propylene glycol dibutyrate and the like.
Specific examples of the alkylene glycol monoalkyl ether having a boiling point of 200 to 300 ° C. include ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethyl butyl ether, propylene glycol phenyl ether, diethylene glycol monoethyl ether, diethylene glycol Monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether, tripropylene glycol methyl ether, tripropylene glycol-n-butyl ether and the like can be mentioned.

Specific examples of the alkylene glycol dialkyl ether having a boiling point of 200 to 300 ° C. include diethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, tetraethylene glycol dimethyl ether and the like.
Among solvents B, from the viewpoint of solubility of a specific polymer, propylene carbonate, ethylene carbonate and butylene carbonate, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol At least one selected from the group consisting of monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether and tripropylene glycol methyl ether is preferred.

The solvent contained in the liquid crystal aligning agent of the present invention preferably contains one combination selected from the following MS1 to MS14 from the viewpoint of achieving both the solubility of the specific polymer and the wettability of the liquid crystal aligning agent;
MS1: N-ethyl-2-pyrrolidone and propylene carbonate MS2: N-cyclohexyl-2-pyrrolidone and propylene carbonate MS3: N- (n-hexyl) -2-pyrrolidone and propylene carbonate MS4: γ-valerolactone And propylene carbonate MS5: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether acetate MS6: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether acetate

MS 7: N-ethyl-2-pyrrolidone and dipropylene glycol monomethyl ether acetate MS 8: N-ethyl 2-pyrrolidone and ethylene glycol monohexyl ether MS 9: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether MS 10 : N-ethyl-2-pyrrolidone and diethylene glycol monopropyl ether MS11: N-ethyl 2-pyrrolidone and diethylene glycol monobutyl ether MS12: N-ethyl 2-pyrrolidone and diethylene glycol monohexyl ether MS13: N-ethyl-2 -Pyrrolidone and dipropylene glycol monopropyl ether · MS 14: N-ethyl-2-pyrrolidone and tripropylene glycol methyl ether

The content ratio of the solvent B in the solvent is preferably 1 to 95% by mass, and more preferably 1 to 90% by mass, with respect to the entire solvent contained in the liquid crystal aligning agent.
The liquid crystal aligning agent of the present invention preferably further contains N-methyl-2-pyrrolidone as a solvent from the viewpoint of enhancing the solubility of the specific polymer and securing the printability. The content ratio is preferably 10 to 90% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 90% by mass with respect to the total amount of the solvent.

The liquid crystal aligning agent of the present invention may be used in combination with other solvents as the solvent. Here, as other solvents, for example, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, methyl methoxypropionate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol-n -Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, low as described in [0203] of WO2011 / 132751 Mention may be made of solvents having a surface tension.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is selected in consideration of viscosity, volatility, etc. However, the range of the solid content concentration which is particularly preferable depends on the method used when applying the liquid crystal aligning agent to the substrate. For example, in the case of the flexographic printing method, it is particularly preferable to set the solid concentration in the range of 3 to 9% by weight and thereby to set the solution viscosity in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable to set the solid content concentration in the range of 1 to 5% by weight and thereby to set the solution viscosity in the range of 3 to 15 mPa · s.

The liquid crystal aligning agent of the present invention includes at least one substituent selected from the group consisting of a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group. Or a crosslinkable compound having a polymerizable unsaturated bond. The crosslinkable compound preferably has two or more of these substituents and polymerizable unsaturated bonds.

As a crosslinkable compound which has an epoxy group or an isocyanate group, the compound as described in [0087] of WO2015 / 008846 etc. are mentioned, for example.
Specific examples of the crosslinkable compound having an oxetane group include the crosslinkable compounds represented by formulas [4a] to [4k] described on pages 58 to 59 of WO2011 / 132751. More preferable specific examples include compounds of the formula [4b], the formula [4d], and the formula [4k] and n = 5.
Specific examples of the crosslinkable compound having a cyclocarbonate group include the crosslinkable compounds represented by Formula [5-1] to Formula [5-42] described on pages 76 to 82 of WO2012 / 014898. Be

As a crosslinkable compound having at least one type of substituent selected from the group consisting of a hydroxyl group and an alkoxyl group, compounds described in [0090] to [0092] of WO 2015/008846, described in [0054] of WO 2015/072554 And compounds described in WO 2014/156314 [0126], and the like. More preferable specific examples are the crosslinkable compounds represented by the formulas [6-1] to [6-48], which are listed in [181] to [185] of WO2011 / 132751, and described in [0054] of WO2015 / 072554 And compounds described in WO 2014/156314 [0126].

As a crosslinkable compound which has a polymerizable unsaturated bond, the compound as described in [0186] of WO2011 / 132751 is mentioned, for example.
In addition, the compound represented by the formula [5] described in [0188] of WO2011 / 132751 can also be used.
The above compounds are examples of crosslinkable compounds and are not limited thereto. In addition, the crosslinkable compound used for the liquid crystal aligning agent of the present invention may be one type or a combination of two or more types.

The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of all the polymer components. Among these, in order to allow the crosslinking reaction to proceed and to exert the desired effect, 0.1 to 100 parts by mass is preferable with respect to 100 parts by mass of all the polymer components. More preferably, it is 1 to 50 parts by mass.
The liquid crystal aligning agent of this invention can use the compound which improves the uniformity of film thickness of a liquid crystal aligning film at the time of apply | coating a liquid crystal aligning agent, and surface smoothness.

As a compound which improves the uniformity of the film thickness of a liquid crystal aligning film, and surface smoothness, a fluorine-type surfactant, a silicone type surfactant, a nonion type surfactant etc. are mentioned. More specifically, for example, F-top EF301, EF303, EF352 (above, made by Tochem Products), Megafuck F171, F173, R-30 (above, made by Dainippon Ink Co., Ltd.), Florards FC430, FC431 (above, Sumitomo 3M Ltd.), Asahi Guard AG 710, Surfron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (all manufactured by Asahi Glass Co., Ltd.) and the like.
The proportion of these surfactants used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 parts by mass with respect to 100 parts by mass of all polymer components contained in the liquid crystal aligning agent. is there.

Furthermore, in the liquid crystal aligning agent of the present invention, as a compound that promotes charge transfer in the liquid crystal alignment film to promote charge loss of the device, pages 69 to 73 of WO2011 / 132751 (released on Oct. 17, 2011). It is also possible to add nitrogen-containing heterocyclic amine compounds represented by the formulas [M1] to [M156] listed below. The amine compound may be added directly to the liquid crystal aligning agent, but is preferably added after being made into a solution with a concentration of 0.1 to 10% by mass, preferably 1 to 7% by mass, using a suitable solvent. The solvent is not particularly limited as long as it dissolves the specific polymer described above.
The liquid crystal aligning agent of the present invention includes, in addition to the above-mentioned poor solvents, crosslinkable compounds, compounds for improving film thickness uniformity and surface smoothness of a resin film or liquid crystal alignment film, and compounds for promoting charge loss, A dielectric or a conductive substance may be added for the purpose of changing the electrical properties such as the dielectric constant and the conductivity of the alignment film.

<Liquid crystal alignment film / Liquid crystal display element>
The liquid crystal aligning agent of the present invention can be used as a liquid crystal alignment film after being applied and baked on a substrate and then subjected to alignment treatment by rubbing treatment, light irradiation and the like. Moreover, in the case of the vertical alignment application etc., it can be used as a liquid crystal aligning film, without an orientation process. The substrate used in this case is not particularly limited as long as it is a highly transparent substrate, and in addition to a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. From the viewpoint of process simplification, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed. In addition, in the reflection type liquid crystal display element, an opaque substrate such as a silicon wafer can be used if it is only on one substrate, and in this case, a material that reflects light such as aluminum can also be used as an electrode.

The liquid crystal aligning agent may be applied by screen printing, offset printing, flexographic printing or ink jet method, dip method, roll coater method, slit coater method, spinner method or spray method, etc. From the viewpoint of increasing the viscosity, a method of coating by flexographic printing or an inkjet method is preferred.

30 to 300 ° C., preferably 30 to 300 ° C. depending on the solvent used for the liquid crystal aligning agent by a heating means such as a hot plate, a thermal circulation type oven or an IR (infrared) type oven after the liquid crystal aligning agent is applied on the substrate. The solvent can be evaporated at a temperature of -250 ° C. to form a liquid crystal alignment film. If the thickness of the liquid crystal alignment film after firing is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display device, and if it is too thin, the reliability of the liquid crystal display device may be lowered. Is 10 to 100 nm.

When the display mode of the manufactured liquid crystal display element is of VA type, the coating film formed as described above can be used as it is as a liquid crystal alignment film, but rubbing treatment or PSA described later may be used as needed. You may process. On the other hand, in the case where the display mode of the liquid crystal display element manufactured is a vertical electric field method other than the VA type or a lateral electric field method, the formed coating film surface is subjected to rubbing treatment or polarized ultraviolet irradiation and the like. Processing is performed for orientation processing.

The liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and includes a liquid crystal composition containing a polymerizable compound polymerized by at least one of active energy ray and heat between the pair of substrates. It is preferably used also for a liquid crystal display device manufactured through a step of arranging a substance, polymerizing a polymerizable compound by at least one of irradiation of active energy rays and heating while applying a voltage between electrodes. Here, the applied voltage can be, for example, direct current or alternating current of 5 to 50 V. Moreover, as an active energy ray, an ultraviolet-ray is suitable. The ultraviolet light is ultraviolet light including light of a wavelength of 300 to 400 nm, preferably ultraviolet light including light of a wavelength of 310 to 360 nm. The irradiation dose of light is preferably 0.1 to 20 J / cm ² , more preferably 1 to 20 J / cm ² .

The liquid crystal display element described above controls the pretilt of liquid crystal molecules by the PSA method. In the PSA method, a small amount of a photopolymerizable compound, for example, a photopolymerizable monomer, is mixed in a liquid crystal material, and after assembling a liquid crystal cell, ultraviolet light is applied to the photopolymerizable compound in a state where a predetermined voltage is applied to the liquid crystal layer. The pretilt of liquid crystal molecules is controlled by the generated polymer. Since the alignment state of the liquid crystal molecules when the polymer is formed is stored even after removing the voltage, the pretilt of the liquid crystal molecules can be adjusted by controlling the electric field or the like formed in the liquid crystal layer. In addition, since the PSA method does not require rubbing treatment, it is suitable for forming a vertical alignment type liquid crystal layer in which it is difficult to control the pretilt by rubbing treatment.

The liquid crystal display element of the present invention is a liquid crystal display element produced by a known method after producing a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above.
A liquid crystal cell is prepared by preparing a pair of substrates on which a liquid crystal alignment film is formed, dispersing spacers on the liquid crystal alignment film on one of the substrates so that the liquid crystal alignment film surface is on the inside, For example, there is a method in which a substrate of the above is attached and sealed by injecting a liquid crystal under reduced pressure, or a method in which a substrate is attached and sealed after liquid crystal is dropped on the liquid crystal alignment film surface to which spacers are dispersed.

The liquid crystal may be mixed with a polymerizable compound which is polymerized by ultraviolet irradiation or heat as described above. As the polymerizable compound, compounds having one or more polymerizable unsaturated groups such as acrylate group and methacrylate group in the molecule, for example, polymerizable compounds represented by the following formulas (M-1) to (M-3) It can be mentioned.

The amount of the polymerizable compound used is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal component. When the amount of the polymerizable compound is less than 0.01 parts by mass, the alignment control of the liquid crystal can not be performed without polymerization of the polymerizable compound, and when the amount is more than 10 parts by mass, the amount of unreacted polymerizable compounds increases The burn-in characteristics of the After producing the liquid crystal cell, while applying an alternating current or direct current voltage to the liquid crystal cell, heat or ultraviolet light is irradiated to polymerize the polymerizable compound. Thereby, the alignment of liquid crystal molecules can be controlled.

In addition, the liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a polymerizable group which polymerizes between the pair of substrates by at least one of active energy ray and heat. A liquid crystal alignment film including the above may be disposed, and a liquid crystal display element manufactured through a process of applying a voltage between the electrodes, that is, the SC-PVA mode may also be used. Here, ultraviolet rays are preferable as the active energy ray. As the ultraviolet light, the ultraviolet light used in the above-mentioned PSA method can be applied including the preferred embodiment. In the case of polymerization by heating, the heating temperature is 40 to 120 ° C., preferably 60 to 80 ° C. Also, ultraviolet light and heating may be performed simultaneously.

In order to obtain a liquid crystal alignment film containing a polymerizable group polymerized from at least one of an active energy ray and heat, a method of adding a compound containing this polymerizable group to a liquid crystal aligning agent, a polymer containing a polymerizable group The method of using an ingredient is mentioned. Specific examples of the polymer containing a polymerizable group include polymers obtained by using a diamine having a function of polymerizing by the light irradiation.

Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to these examples.
(Specific diamine)
W-A1: compound represented by the formula [W-A1] W-A2: compound represented by the formula [W-A2] W-A3: compound represented by the formula [W-A3]

(Other side chain type diamine compounds)
A1: a compound represented by the formula [A1]

C1: compound represented by Formula [C1], C2: compound represented by Formula [C2] C3: compound represented by Formula [C3]

(Tetracarboxylic acid compound)
D1: 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride D2: bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid dianhydride D3: pyromellitic acid dianhydride object

(solvent)
NEP: N-ethyl-2-pyrrolidone, GVL: γ-valerolactone,
GBL: γ-butyrolactone NMP: N-methyl-2-pyrrolidone
CHP: N-cyclohexyl-2-pyrrolidone, NHP: N- (n-hexyl) -2-pyrrolidone 3BMP: 3-butoxy-N, N-dimethylpropanamide, PC: propylene carbonate EC: ethylene carbonate DEMBA: diethylene glycol monobutyl ether Acetate DPMEA: Dipropylene glycol monomethyl ether acetate EMH: Ethylene glycol monohexyl ether

DEME: diethylene glycol monoethyl ether DEMP: diethylene glycol monopropyl ether DEMB: diethylene glycol monobutyl ether DEMH: diethylene glycol monohexyl ether DPMP: dipropylene glycol monopropyl ether TPME: tripropylene glycol methyl ether

(Molecular weight measurement)
The molecular weight of the polyimide precursor and the polyimide is as follows using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko KK) and a column (KD-803, KD-805) (manufactured by Shodex Co., Ltd.) It measured like.
Column temperature: 50 ° C
Eluent: N, N'-dimethylformamide (as additive, 30 mmol / L (liter) of lithium bromide-hydrate (LiBr · H ₂ O), 30 mmol of phosphoric acid / anhydrous crystal (o-phosphoric acid) / L, tetrahydrofuran (THF) 10 ml / L, flow rate: 1.0 ml / min Standard sample for preparation of calibration curve: TSK standard polyethylene oxide (molecular weight; about 900,000, 150,000, 100,000 and 30,000) ) (Manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; about 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratory).

(Measurement of imidation rate)
20 mg of polyimide powder is placed in an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Scientific Co., Ltd.)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05% by mass TMS (tetramethylsilane) The mixture (0.53 ml) was added and sonicated to dissolve completely. This solution was subjected to proton NMR measurement at 500 MHz with an NMR measurement device (JNW-ECA 500) (manufactured by Nippon Denshi Datum Co., Ltd.). The imidation ratio is determined using a proton derived from a structure that does not change before and after imidization as a reference proton, and a peak integrated value of this proton and a proton peak derived from the NH group of amic acid appearing around 9.5 to 10.0 ppm It calculated | required by the following formula using integration value.
Imidation ratio (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from the NH group of the amic acid, y is a peak integrated value of the reference proton, and α is one NH group proton of the amic acid in the case of polyamic acid (imidation ratio is 0%) The ratio of the number of reference protons to.

(Viscosity measurement)
The viscosity of the polyimide polymer was measured at a sample volume of 1.1 mL, cone rotor TE-1 (1 ° 34 ', R24) at a temperature of 25 ° C. using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) did.

<Synthesis of Specific Diamine>
W-A1 to W-A3 are novel compounds which have not been published in literatures and so forth, and were synthesized as follows.
The products described in the following Synthesis Examples 1 to 3 were identified by ¹ H-NMR analysis under the following conditions.
Equipment: Varian NMR System 400 NB (400 MHz)
Measurement solvent: CDCl _3, DMSO-d ₆
Reference material: tetramethylsilane (TMS) (δ 0.0 ppm for ¹ H)

Synthesis Example 1 Synthesis of W-A1

<Synthesis of Compound [1], [2]>
To a reaction vessel is added 4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (41.1 g, 135 mmol) and triethylamine (31.5 g) in tetrahydrofuran (165.6 g), The methanesulfonyl chloride (33.2 g) was added dropwise under atmosphere ice-cold conditions, and the reaction was conducted for 1 hour to obtain a compound [1]. Subsequently, p- (trans-4-heptylcyclohexyl) phenol (77.8 g) dissolved in tetrahydrofuran (246.6 g) is added, and after stirring for 1 hour at 40 ° C., water dissolved in pure water (233 g) Potassium oxide (41.0 g) was added at the same temperature and allowed to react for 21 hours. After completion of the reaction, 1.0 M aqueous hydrochloric acid solution (311 ml) and pure water (1050 g) were added to precipitate a crude product, and the crude product was recovered by filtration. The obtained crude product was dissolved by heating in tetrahydrofuran (574 g) at 50 ° C., methanol (328 g) was added to precipitate crystals, and filtration and drying gave a compound [2] (yield: 97.9 g, yield) Rate: 89%).

¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6 H), 0.96-1.05 ppm (m, 4 H), 1.19-1.39 ppm (m, 30 H), 1.80-1.85 ppm (m, 8 H), 2.33-2.40 ppm (m, 2 H), 4.77 ppm (s, 4 H), 6.66-6.70 ppm (m, 4 H), 7. 02-7.06 ppm (m, 4 H), 7. 40 ppm (d, 2 H, 8.4), 8. 25 ppm (dd, 2 H, J = 2.4 Hz, J = 8.4 Hz), 8.54 ppm (d , 2H, J = 2.4 Hz).

<Composition of W-A1>
Tetrahydrofuran (1783 g), compound [2] (74.3 g, 90.9 mmol) and 3% platinum carbon (5.94 g) were added to a reaction vessel and reacted under hydrogen atmosphere at room temperature. After completion of the reaction, the reaction mixture was filtered, and the filtrate was concentrated under reduced pressure to a total internal weight of 145 g. Subsequently, methanol (297 g) was added to the concentrated solution, the mixture was stirred under ice cooling, filtered and dried to obtain W-A1 (yield: 59.2 g, 86%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6 H), 0.96-1.05 ppm (m, 4 H), 1.19-1.40 ppm (m, 30 H), 1.81-1.84 ppm (m, 8 H), 2.32-2.38 ppm (m, 2 H), 3.67 ppm (s, 4 H), 4.69 ppm (d, 2 H, J = 12.0 Hz), 4.74 ppm (d, 2 H, J = 11.6 Hz), 6.62 ppm (dd, 2 H, J = 2.4 Hz, J = 8.0 Hz), 6.70-6.75 ppm (m, 4 H), 6 91 ppm (d, 2 H, J = 2.4 Hz), 6.97-7.03 ppm (m, 6 H).

Synthesis Example 2 Synthesis of W-A2

<Synthesis of Compound [3]>
Tetrahydrofuran (327.2 g), 4,4'-dinitro-2,2'-diphenic acid (40.9 g, 123 mmol) and p- (trans-4-heptylcyclohexyl) phenol (72.1 g) in a reaction vessel, 4 -Dimethylaminopyridine (1.50 g) was added, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (56.6 g) was added under nitrogen atmosphere and room temperature conditions, and reacted for 3 hours. After completion of the reaction, the reaction solution was poured into pure water (1226 g) to precipitate a crude product, which was recovered by filtration. Subsequently, the crude product was slurry-washed with methanol (245 g), filtered, and the obtained crude product was dissolved by heating in tetrahydrofuran (245 g) at 60 ° C. The insoluble matter is removed by filtration, and the internal weight is reduced to 232 g by vacuum concentration, and then methanol (163 g) is added to precipitate crystals, and the mixture is stirred under ice-cold conditions, filtered and dried to obtain a compound [3] (Yield: 73.9 g, 71%).

¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6 H), 0.98-1.06 ppm (m, 4 H), 1.18-1.43 ppm (m, 30 H), 1.83-1.86 ppm (m, 8 H), 2.41-2. 47 ppm (m, 2 H), 6. 89-6. 92 ppm (m, 4 H), 7. 17-7. 20 ppm (m, 4 H) ), 7.48 ppm (d, 2 H, 8.4), 8. 49 ppm (dd, 2 H, J = 2.4 Hz, J = 8.4 Hz), 9.11 ppm (d, 2 H, J = 2.4 Hz) .

<Composition of W-A2>
Tetrahydrofuran (443 g) and methanol (73.9 g), compound [3] (73.9 g, 87.4 mmol) and 5% palladium carbon (8.80 g) were added to a reaction vessel and reacted under hydrogen atmosphere at room temperature. After completion of the reaction, palladium carbon was removed by filtration and concentrated under reduced pressure to a total internal weight of 171 g. Subsequently, methanol (222 g) was added to the concentrated solution to precipitate crystals, and the mixture was stirred under ice cooling, filtered and dried to obtain W-A2 (yield: 66.6 g, yield: 97%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.90 ppm (m, 6 H), 0.96-1.05 ppm (m, 4 H), 1.17-1. 42 ppm (m, 30 H), 7. 82-1.85 ppm (m, 8 H), 2.38-2.44 ppm (m, 2 H), 3. 77 ppm (s, 4 H), 6. 80-6. 87 ppm (m, 6 H), 7. 08-7.13 ppm (m, 6 H), 7.41 ppm (d, 2 H, J = 2.4 Hz).

Synthesis Example 3 Synthesis of W-A3

<Synthesis of Compound [4], [5]>
Toluene (366 g), 4- (trans-4-heptylcyclohexyl) -benzoic acid (73.1 g, 242 mmol) and N, N-dimethylformamide (0.73 g) were added to a reaction vessel, and a nitrogen atmosphere was applied at 50 ° C. Thionyl chloride (35.9 g) was added dropwise. After dropping, the mixture was reacted at the same temperature for 1 hour, and the reaction solution was concentrated under reduced pressure to obtain compound [4]. Subsequently, 4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (35.0 g, 115 mmol) and triethylamine (26.8 g) are charged in tetrahydrofuran (210 g), and nitrogen atmosphere ice is used. Under cold conditions, the compound [4] dissolved in tetrahydrofuran (73. 1 g) was dropped. After completion of the dropwise addition, the reaction was allowed to proceed to room temperature for 18 hours. After completion of the reaction, the triethylamine hydrochloride was removed by filtration and then concentrated under reduced pressure to obtain an oily compound. The resulting oily compound was added to pure water (1015 g) to precipitate crystals, and the crude product was recovered by filtration. Subsequently, the obtained crude product was slurry-washed with methanol (291 g) at room temperature, slurry-washed with ethyl acetate (175 g) at room temperature, filtered and dried to obtain compound [5] (yield: 92.7 g, Rate: 92%).

¹ H-NMR (400 MHz) in CDCl ₃ : 0.89-0.91 ppm (m, 6 H), 0.99-1.09 ppm (m, 4 H), 1.20-1. 47 ppm (m, 30 H), 1.85-1.88 ppm (m, 8 H), 2.46-2.52 ppm (m, 2 H), 5.14 ppm (s, 4 H), 7.23-7.26 ppm (m, 4 H), 7. 45 ppm (d, 2 H, J = 8.4 Hz), 7.83-7.86 ppm (m, 4 H), 8. 27 ppm (dd, 2 H, J = 2.4 Hz, J = 8.4 Hz), 8. 47 ppm (D, 2H, J = 2.4 Hz).

Synthesis of W-A3
Tetrahydrofuran (484 g) and methanol (161 g), compound [5] (80.5 g, 92.2 mmol) and 3% platinum carbon (6.44 g) were added to a reaction vessel and reacted under hydrogen atmosphere at room temperature. After completion of the reaction, platinum carbon was removed by filtration, and the solvent was removed by concentration under reduced pressure to a total internal weight of 96.6 g. Subsequently, methanol (322 g) was added to the concentrated solution to precipitate crystals, and the mixture was stirred under ice cooling and filtered to obtain a crude product. Subsequently, the obtained crude product was dissolved by heating at 60 ° C. with ethyl acetate (322 g), methanol (700 g) was added, crystals were precipitated under ice-cold conditions, filtered and dried to obtain W-A3. (Yield: 67.9 g, yield: 91%).

¹ H-NMR (400 MHz) in CDCl ₃ : 0.87-0.91 ppm (m, 6 H), 0.98-1.08 ppm (m, 4 H), 1.19-1.47 ppm (m, 30 H), 1.84-1.87 ppm (m, 8 H), 2.44-2.51 ppm (m, 2 H), 3.71 ppm (s, 4 H), 5.02 ppm (d, 2 H, J = 12.8 Hz), 5.09 ppm (d, 2 H, J = 12.4 Hz), 6.66 ppm (dd, 2 H, J = 2.4 Hz, J = 8.0 Hz), 6.84 ppm (d, 2 H, J = 2.4 Hz) , 7.03 ppm (d, 2 H, J = 8.0 Hz), 7.19-7.25 ppm (m, 4 H), 7.89-7.92 ppm (m, 4 H).

<Synthesis of polymer>
Synthesis Example 1
D2 (2.50 g, 10.0 mmol), W-A1 (3.03 g, 4.00 mmol), and C1 (1.73 g, 16.0 mmol) in NMP (18.1 g) and NEP (18.1 g) After dissolving in mixed solvent and reacting at 60 ° C for 3 hours, D1 (1.78 g, 9.10 mmol) is added and allowed to react at 40 ° C for 3 hours to obtain a 20 mass% resin solid content concentration of polyamic acid solution (viscosity : 840 mPa · s) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6.5 mass%, acetic anhydride (4.43 g) and pyridine (1.37 g) are added as an imidation catalyst, and the reaction is carried out at 80 ° C. It was allowed to react for 3 hours. The reaction solution was poured into methanol (382 ml) and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder (PI-1). The imidation ratio of this polyimide was 76.4%, Mn was 16,165, and Mw was 49, 988.

Synthesis Example 2
D2 (2.50 g, 10.0 mmol), W-A2 (3.14 g, 4.00 mmol), and C1 (1.84 g, 16.0 mmol) in NMP (11.1 g) and PC (25.8 g) After dissolving in a mixed solvent and reacting at 60 ° C. for 3 hours, D1 (1.84 g, 9.38 mmol) is added and allowed to react at 40 ° C. for 3 hours, and a polyamic acid solution (resin viscosity 20% by mass solid content) : 658 mPa · s) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6.5 mass%, acetic anhydride (4.38 g) and pyridine (1.36 g) are added as an imidation catalyst, and the reaction is carried out at 80.degree. It was allowed to react for 3 hours. The reaction solution was poured into methanol (382 ml) and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder (PI-2). The imidation ratio of this polyimide was 75.8%, Mn was 15,430, and Mw was 45,756.

Synthesis Example 3
D2 (2.50 g, 10.0 mmol), W-A3 (3. 25 g, 4.00 mmol), and C1 (1.73 g, 16.0 mmol) are mixed in GVL (37.3 g) and After reacting for 3 hours, D1 (1.84 g, 9.38 mmol) was added and reacted at 40 ° C. for 3 hours to obtain a polyamic acid solution (viscosity: 656 mPa · s) having a resin solid concentration of 20% by mass.
GVL was added to the obtained polyamic acid solution (20.0 g) and diluted to 6.5 mass%, then acetic anhydride (4.32 g) and pyridine (1.34 g) were added as an imidization catalyst, and the mixture was heated at 80 ° C. It was allowed to react for 3 hours. The reaction solution was poured into methanol (382 ml) and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder (PI-3). The imidation ratio of this polyimide was 74.7%, Mn was 13,340, and Mw was 41,948.

[Comparative Example 1]
Add D2 (2.88 g, 11.5 mmol), A1 (0.60 g, 1.2 mmol), C2 (3.32 g, 21.8 mmol) and NMP to make the set concentration 20 mass%, and react at 60 ° C. for 3 hours Then, D1 (2.19 g, 11.2 mmol) and NMP are added to make the set concentration 20 mass%, and the reaction is carried out at 40 ° C. for 3 hours, and a polyamic acid solution (viscosity: 600 mPa・ I got s).
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting to 6.5 mass%, acetic anhydride (4.64 g) and pyridine (1.44 g) are added as an imidation catalyst, and the reaction is carried out at 80 ° C. It was allowed to react for 3 hours. The reaction solution was poured into methanol (382 ml) and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder (PI-R1). The imidation ratio of this polyimide was 57%, Mn was 13,100, and Mw was 33,200.

[Comparison Example 2]
A polyimide powder (PI-R2) was obtained in the same manner as in the polymer comparative synthesis example 1 except that the type and composition of the diamine used were changed as described in Table 1 below. The imidation ratio of this polyimide was 65%, Mn was 10,500, and Mw was 20,900.

Example 1
The polyimide (PI-1) obtained in the above polymer synthesis example 1 is dissolved in a mixed solvent (mixing ratio (weight ratio) = 20: 50: 30) consisting of NEP, GVL and PC, and the solid content concentration is A 6.5% by mass liquid crystal aligning agent (S-1) was obtained. The resultant was filtered with a filter having a pore size of 0.2 μm, and then subjected to the following evaluation of flexographic printability and evaluation of liquid crystal alignment.

<Evaluation of inkjet coatability>
As a substrate to which a liquid crystal aligning agent is applied, a substrate just after ultraviolet cleaning of a stepped substrate (made of glass) having a height of 0.5 μm, a line width of 50 μm, and an inter-line space of 120 μm was used.
The liquid crystal aligning agent (after filtration) prepared above was applied onto the above glass substrate using HIS-200 (manufactured by Hitachi Plant Technologies, Ltd.). The coating conditions at this time were a coating area of 70 mm × 70 mm, a nozzle pitch of 0.423 mm, a scan pitch of 0.5 mm, and a coating speed of 40 mm / sec. After standing for 60 seconds after application, the film was heated at 70 ° C. to form a coating having an average film thickness of 100 nm. With respect to the obtained coating film, evaluation of the coating film property and evaluation of the linearity of the liquid crystal alignment film end were performed.

The coating property is evaluated by observing with naked eye under irradiation of interference fringe measurement lamp (sodium lamp), and it is excellent when both unevenness and reed is not seen, and at least one of unevenness and reed is seen. The case where both good, unevenness and reed were seen was evaluated as a defect.
The evaluation of the linearity of the end of the liquid crystal alignment film was performed by observing the coating on the right end with respect to the printing direction with an optical microscope (ECLIPSE E600WPOL, manufactured by Nikon Corporation). Specifically, the magnification was observed with an optical microscope at a magnification of 25 and evaluated according to the following evaluation criteria.
Excellent: homogeneous line shape was obtained on all four sides.
Good: Line width disturbance was observed on one to three sides.
Poor: Line width disturbance was generally observed.

<Evaluation of flexographic printability>
The liquid crystal aligning agent prepared above was subjected to a coatability test by performing flexographic printing on a cleaned Cr plate using an alignment film printer ("Ong Stromer" manufactured by Nipponsha Printing Co., Ltd.). About 1.0 mL of the liquid crystal aligning agent was dropped onto the anilox roll, and after performing idle operation 20 times, the printing press was stopped for 10 minutes under the atmosphere to dry the printing plate. Thereafter, printing was performed on one Cr substrate, and the substrate after printing was heated to 70 ° C. to observe the film state. The observation was performed by visual observation and an optical microscope (“ECLIPSE ME600” manufactured by Nikon Corporation) at 50 ×. Excellent when no film thickness unevenness at the pinhole and edge is observed, good when one of film thickness unevenness at the pinhole and edge is observed, both film thickness unevenness at the pinhole and edge occur. Was rated as poor.

<Manufacture of liquid crystal cell>
The liquid crystal aligning agent prepared above was subjected to pressure filtration with a membrane filter having a pore diameter of 1 μm. The above-mentioned inkjet coating is performed on the ITO surface of a 40 mm × 30 mm ITO electrode-attached glass substrate (length: 40 mm, width: 30 mm, thickness: 1.1 mm) in which the obtained solution is washed with pure water and IPA (isopropyl alcohol) Alternatively, a film is formed by flexographic printing, and heat treatment is performed at 70 ° C. for 90 seconds on a hot plate at 230 ° C. for 30 minutes in a heat circulating clean oven to form a liquid crystal alignment film having a thickness of 100 nm. An attached ITO substrate was obtained. Two ITO substrates with a liquid crystal alignment film thus obtained were prepared, and a bead spacer (with Jiro Catalyst Chemicals Co., Ltd., spherical sphere, SW-D1) having a diameter of 4 μm was coated on the liquid crystal alignment film surface of one of the substrates.

Next, the periphery was coated with a sealing agent (XN-1500T manufactured by Mitsui Chemicals, Inc.). Next, with the surface on the side on which the liquid crystal alignment film of the other substrate was formed facing inside, and pasted to the previous substrate, the sealing material was cured to form an empty cell. A negative liquid crystal MLC-3023 (trade name of Merck & Co., Inc.) was injected into this empty cell by a pressure reduction injection method to prepare a liquid crystal cell.
Then, in the resulting state of applying a DC voltage of 15V to the liquid crystal cell, using an ultraviolet irradiation apparatus using a high pressure mercury lamp as a light source, ultraviolet rays through a band-pass filter having a wavelength of 365 nm 15 J / cm ² was irradiated A vertical alignment type liquid crystal display device was obtained. In addition, the UV-35 light receiver was connected to UV-M03A manufactured by ORC and used for measurement of the ultraviolet irradiation amount.

<Evaluation of liquid crystal alignment>
The liquid crystal alignment of the liquid crystal display element was observed with a polarization microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) to check whether the liquid crystal was vertically aligned. Specifically, those in which no bright spots due to defects due to the liquid crystal flow or alignment defects were found were considered to be good.
[Examples 2 to 19 and Comparative Examples 1 to 4]
Liquid crystal aligning agents (S-2) to (S-19), in the same manner as in Example 1, except that the type and composition of the polymer and solvent used were changed as described in Table 2 below. (RS-1) to (RS-4) were prepared respectively. Further, for each liquid crystal aligning agent, any of flexographic printing property, liquid crystal alignment property, or ink jet coatability was evaluated. The results are shown in Table 2 below.

In Table 2, the numerical value of the polymer indicates the blending ratio (mass ratio) of each polymer to the total amount of the polymer used for the preparation of the liquid crystal aligning agent. The numerical value of the solvent composition indicates the blending ratio (mass ratio) of each compound to the total amount of the solvent used for the preparation of the liquid crystal aligning agent.
As can be seen from the above results, the liquid crystal alignment film obtained from the liquid crystal alignment agent of the example has ink jet printability, flexographic printability and liquid crystal alignment as compared to the liquid crystal alignment film obtained from the liquid crystal alignment agent of the comparative example. The liquid crystal aligning film which achieved all of can be obtained.

The liquid crystal aligning agent of the present invention can suppress coating defects of the alignment film caused by the influence of the wiring structure and C / H, and can suppress the drying of the liquid crystal aligning agent even when flexographic printing is performed. It is. In addition, the liquid crystal display device having the liquid crystal alignment film obtained in this manner can display an image of high quality, and can be suitably used for a large screen and high definition liquid crystal television etc., and a TN element, STN element, TFT liquid crystal It is useful for a liquid crystal display device of a vertical alignment type such as a device.

The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2017-223899 filed on Nov. 21, 2017 are hereby incorporated by reference as the disclosure of the specification of the present invention. , Is to introduce.

Claims

At least one polymer selected from the group consisting of a polyamic acid having a structure of the following formula [1], a polyamic acid ester, and a polyimide that is an imidized product thereof;
Alkylene glycol monoalkyl ether acetate having at least one solvent A selected from the group consisting of the following formulas (d-1) to (d-5), and the following formula (e), and having a boiling point of 200 to 300 ° C. A solvent comprising at least one solvent B selected from the group consisting of diacetate, alkylene glycol monoalkyl ether, and alkylene glycol dialkyl ether;
Liquid crystal aligning agent characterized by containing.

X is a single bond, -O -, - C (CH 3) 2 -, - NH -, - CO -, - NHCO -, - COO -, - (CH 2) m -, - SO 2 -, and their It represents a divalent organic group consisting of any combination, and m represents an integer of 1 to 8. Two Y's each independently represent a side chain structure selected from the following formulas [S1] to [S3] or a structure derived from tocopherol.

X 1 and X 2 are independently a single bond,-(CH 2 ) a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH 3 )-, -NH -, -O-, -COO-, -OCO-, or ((CH 2 ) a1 -A 1 ) m1- (a1 represents an integer of 1 to 15, and A 1 represents an oxygen atom, -COO or OCO In which m 1 is 1 to 2), and G 1 and G 2 independently represent a C 6-12 divalent aromatic group or a C 3-8 divalent alicyclic group And the hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, or a fluorine-containing alkyl group having 1 to 3 carbon atoms. And may be substituted with a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom, and m and n each independently represent an integer of 0 to 3 A is, these total is 1 ~ 4, R 1 is an alkoxyalkyl alkyl, alkoxy of 1 to 20 carbon atoms, or 2 to 20 carbon atoms having 1 to 20 carbon atoms, optionally in these groups Hydrogen may be replaced by fluorine.
X 3 represents a single bond, -CONH-, -NHCO-, -CON (CH 3 )-, -NH-, -O-, -CH 2 O-, -COO- or OCO-, and R 2 represents carbon The alkyl is an alkyl of 1 to 20 or an alkoxyalkyl of 2 to 20 carbons, and any hydrogen in these groups may be replaced by fluorine.
X 4 represents —CONH—, —NHCO—, —O—, —COO— or OCO—, and R 3 represents a structure having a steroid skeleton.

R 1a represents a monovalent hydrocarbon group having 2 to 8 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds in the hydrocarbon group, and R 2a and R 2b are independently Is an alkyl group having 1 to 6 carbon atoms, R 3a is a methyl group or an ethyl group, R 5a is an alkyl group having 1 to 6 carbon atoms, and R 5b and R 5c are independently hydrogen atoms Or a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a monovalent group having “—O—” between carbon-carbon bonds of the hydrocarbon group, and n is 1 or 2.

In the formula, r 1a and r 1b independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and m is an integer of 2 to 6.
The X in the above formula [1] is a single bond, -O-, -NH-, or -O- (CH 2 ) m -O- (m represents an integer of 1 to 8). The liquid crystal aligning agent as described in.
Solvent A is N-ethyl-2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N- (n-hexyl) -2-pyrrolidone, N-methoxypropyl-2 -Pyrolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, 3-butoxy-N, N-dimethylpropanamide, and 3-methoxy-N, N The liquid crystal aligning agent according to any one of claims 1 or 2, which is at least one solvent selected from the group consisting of -dimethylpropanamide.
Solvent B is propylene carbonate, ethylene carbonate, butylene carbonate, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether The liquid crystal aligning agent according to any one of claims 1 to 3, which is at least one solvent selected from the group consisting of diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol methyl ether.
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the solvent contains one combination selected from the group consisting of MS1 to MS14 described below.
MS1: N-ethyl-2-pyrrolidone and propylene carbonate MS2: N-cyclohexyl-2-pyrrolidone and propylene carbonate MS3: N- (n-hexyl) -2-pyrrolidone and propylene carbonate MS4: γ-valerolactone And propylene carbonate MS5: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether acetate MS6: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether acetate MS7: N-ethyl-2-pyrrolidone and dipropylene glycol monomethyl ether Acetate MS 8: N-ethyl-2-pyrrolidone and ethylene glycol monohexyl ether MS 9: N-ethyl 2-pyrrolidone and diethylene glycol monoethyl ether M 10: N-ethyl-2-pyrrolidone and diethylene glycol monopropyl ether MS11: N-ethyl 2-pyrrolidone and diethylene glycol monobutyl ether MS12: N-ethyl 2-pyrrolidone and diethylene glycol monohexyl ether MS 13: N-ethyl- 2-Pyrrolidone and dipropylene glycol monopropyl ether MS14: N-ethyl-2-pyrrolidone and tripropylene glycol methyl ether
The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the content ratio of the solvent B in the solvent is 1 to 95 mass%, and the content ratio of the solvent A in the solvent is 5 to 99 mass%. .
The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the solvent further contains N-methyl-2-pyrrolidone.
The liquid crystal aligning agent according to claim 7, wherein the content ratio of N-methyl-2-pyrrolidone is 10 to 90% by mass.
The polyamic acid, polyamic acid ester, and polyimide react with a tetracarboxylic acid compound and a diamine represented by the following formula [2], or a diamine represented by the following formula [2] and a mixture of other diamines The liquid crystal aligning agent according to any one of claims 1 to 8, which is obtained by

(Wherein, X and Y have the same meaning as X and Y in the above-mentioned formula [1])
The liquid crystal aligning agent according to claim 9, wherein the tetracarboxylic acid compound is at least one or more of tetracarboxylic acid dianhydride having a structure represented by the following formula [4] and a tetracarboxylic acid derivative thereof.

Z represents a structure selected from the group consisting of the following [4a] to [4k].

(Wherein * 1 is a bond to be bonded to one acid anhydride group, * 2 is a bond to be bonded to the other acid anhydride group. In the formula [4a], Z 1 to Z 4 are Independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring)
The liquid crystal aligning agent of Claim 10 whose tetracarboxylic-acid compound shown by said Formula [4] is 5 mol% or more in 100 mol% of all the tetracarboxylic-acid compounds.
The liquid crystal aligning agent according to any one of claims 9 to 11, wherein the other diamine comprises a diamine having a function of generating polymerization or radical upon irradiation with light.
A method for producing a liquid crystal alignment film, comprising the steps of applying the liquid crystal alignment agent according to any one of claims 1 to 12 on a substrate surface by flexographic printing or an inkjet method, and baking it.
A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 12.
The liquid crystal display element which comprises the liquid crystal aligning film of Claim 14.
A liquid crystal composition comprising a liquid crystal layer is provided between a pair of substrates provided with an electrode, and a polymerizable compound polymerized by at least one of an active energy ray and heat is disposed between the pair of substrates. The liquid crystal alignment film according to claim 14, which is used for a liquid crystal display device manufactured through the step of polymerizing the polymerizable compound while applying a voltage between them.
The liquid crystal display element which comprises the liquid crystal aligning film of Claim 16.