阅读说明：本技术 液晶取向剂、液晶取向膜及液晶表示元件 (Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element ) 是由 长谷川直史 野田尚宏 永井健太郎 于 2019-10-24 设计创作，主要内容包括：提供一种液晶取向剂,其可以形成提供视场角宽、应答速度快、对比度大的液晶表示元件的液晶取向膜。一种液晶取向剂,其特征在于,其含有具有下述式(1)所示的侧链和下述式(2)所示的侧链的聚合物。(R-(1c)、R-(2c)：氢原子或碳数1～10的烷基。Y-c：单键或-CO-,Ar～1：亚苯基、亚萘基或亚联苯基,T-(1c)、T-(2c)：单键、-O-、-COO-等,A-c：单键、碳数1～20的亚烷基等,n：1～4,*：连接键)(Q：式(q-1)～(q-4)等,R-(1r)、R-(2r)：碳数1～10的烷基或烷氧基等,Ar～2：2价芳香族烃基,T-(1r)、T-(2r)：单键、-O-、-COO-等,A-r：单键、碳数1～20的亚烷基等,*：连接键)(Provided is a liquid crystal aligning agent which can form a liquid crystal alignment film for providing a liquid crystal display element having a wide viewing angle, a high response speed, and a large contrast. A liquid crystal aligning agent characterized by containing a polymer having a side chain represented by the following formula (1) and a side chain represented by the following formula (2). (R) 1c 、R 2c : a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Y is c : a single bond or-CO-, Ar 1 : phenylene, naphthylene or biphenylene, T 1c 、T 2c : single bond, -O-, -COO-, etc., A c : a single bond, an alkylene group having 1 to 20 carbon atoms, etc., n: 1-4, x: connecting bond) (Q: formulae (q-1) to (q-4), etc., R 1r 、R 2r : alkyl or alkoxy group having 1 to 10 carbon atoms, Ar 2 : 2-valent aromatic hydrocarbon radical, T 1r 、T 2r : single bond, -O-, -COO-, etc., A r : a single bond, an alkylene group having 1 to 20 carbon atoms, etc.: connecting key))

1. A liquid crystal aligning agent characterized by containing a polymer having a side chain represented by the following formula (1) and a side chain represented by the following formula (2),

R_1c、R_2ceach independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Y_cRepresents a single bond or-CO-, Ar¹Represents phenylene, naphthylene or biphenylene, T_1c、T_2cEach independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃)CO-，A_cRepresents a single bond, an alkylene group having 1 to 20 carbon atoms optionally substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms, a 2-valent alicyclic group having 3 to 8 carbon atoms, or a 2-valent heterocyclic group selected from pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran and thiophene, n represents an integer of 1 to 4, and x represents a bonding position to an adjacent atom,

q represents a group selected from the following formulae (Q-1) to (Q-4), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R represents a C1-C4 alkyl group₃represents-CH₂-, -NR-, -O-or-S-, R_1r、R_2rEach independently represents an alkyl group or alkoxy group having 1 to 10 carbon atoms, a benzyl group or a phenethyl group, Ar²Represents a 2-valent aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, an organic group optionally substituted thereon, a hydrogen atom optionally substituted with a halogen atom, T_1r、T_2rEach independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃)CO-，A_rRepresents a single bond, an alkylene group having 1 to 20 carbon atoms which is optionally substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms, a 2-valent alicyclic group having 3 to 8 carbon atoms, or a 2-valent heterocyclic group selected from pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran and thiophene, represents a bonding position to an adjacent atom,

2. the liquid crystal aligning agent according to claim 1, wherein in the formula (1), -Ar¹-(Y_c-CHR_1cR_2c)_nThe following (ch-1) to (ch-6) are shown,

R_1c、R_2cthe same as in the above formula (1).

3. The liquid crystal aligning agent according to claim 1 or 2, wherein in the formula (2), Ar²Represents a phenylene group or a biphenylene group,

T_1r、T_2reach independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-or-CH₂O-，

A_rRepresents a single bond, optionally taken by a fluorine atomA substituted alkylene group having 1 to 20 carbon atoms, a 2-valent aromatic ring group having 6 to 12 carbon atoms, or a 2-valent alicyclic group having 3 to 8 carbon atoms.

4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polymer is at least one polymer selected from the group consisting of a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor.

5. The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the polymer is a copolymer comprising a unit having a side chain represented by the formula (1) and a unit having a side chain represented by the formula (2), and/or a mixture comprising a polymer having a side chain represented by the formula (1) and a polymer having a side chain represented by the formula (2).

6. The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the polymer is a polymer having a side chain represented by the following formula (3) in addition to the side chain represented by the formula (1) and the side chain represented by the formula (2),

l, m and n each independently represent an integer of 0 or 1, R₁Is represented by- (CH)₂)_a-、-CONH-、-NHCO-、-CON(CH₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-, - (CH)₂)_a1-A₁-(CH₂)_a2-A₂-, where a is an integer of 1 to 15, A₁Is an oxygen atom or-COO-, wherein a connecting bond and (CH) are attached₂)_a2Bonding of A₂Is an oxygen atom or-COO-wherein a bond and (CH) are attached₂)_a2A1 is an integer of 0 or 1, a2 is an integer of 1-10, R²、R³And R⁴Each independently represents phenylene, fluorine-containing phenylene orCycloalkylene radical, R⁵Represents a linear alkyl group having 2 to 24 carbon atoms, a fluoroalkyl group having 2 to 24 carbon atoms, an alkoxy group having 2 to 24 carbon atoms, an alkoxyalkyl group having 2 to 20 carbon atoms or a structure having a steroid skeleton, wherein R is⁵When the alkyl group is a linear alkyl group having 2 to 24 carbon atoms or a fluoroalkyl group having 2 to 24 carbon atoms, the sum of l + m + n is not less than 1, and R is⁵When the structure has a steroid skeleton, l, m and n represent 0, and R represents¹Is represented by- (CH)₂)_a-、-CONH-、-NHCO-、-CON(CH₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-, wherein a is an integer of 1 to 15.

7. The liquid crystal aligning agent according to claim 6, wherein the polymer is a copolymer comprising a unit having the side chain represented by formula (1) and a unit having the side chain represented by formula (2), and a unit having the side chain represented by formula (3), and/or a mixture comprising a polymer having the side chain represented by formula (1) and a polymer having the side chain represented by formula (2) and a polymer having the side chain represented by formula (3).

8. The liquid crystal aligning agent according to any one of claims 1 to 7, wherein the polymer is obtained by using a diamine represented by the following formula (d-1) as a part of a raw material,

R_1c、R_2c、Y_c、Ar¹、T_1c、T_2c、A_cand n is the same as the formula (1).

9. The liquid crystal aligning agent according to any one of claims 1 to 8, wherein the polymer is obtained by using a diamine represented by the following formula (d-2) as a part of a raw material,

R_1r、R_2r、Y_r、Ar²、T_1r、T_2r、A_rthe same as the above formula (2).

10. The liquid crystal aligning agent according to any one of claims 1 to 9, wherein the polymer is obtained by using a diamine represented by the following formula (d-3) as a part of a raw material,

l, m, n and R¹～R⁵Is as defined in the above formula (3), z represents an integer of 1 to 2, Y₃Is represented by the following formula (Ar)_3-1)～(Ar_3-2) In the structure shown in the figure, the structure,

A_3arepresents a single bond or a 2-valent organic group having an aromatic group, A_3bRepresents a 3-valent group having an aromatic group, and 1 represents p-R¹-(R²)_l-(R³)_m-(R⁴)_n-R⁵2 represents p-NH₂The bonding position of (2).

11. The liquid crystal aligning agent according to any one of claims 1 to 10, wherein the polymer is obtained by using a tetracarboxylic dianhydride represented by the following formulae [4] to [6] as a part of a raw material,

Z¹is represented by a formula [4a ] selected from]-formula [4k]At least one structure of the formula [5]]Or formula [6]Wherein j and k are each independently an integer of 0 or 1, x and y each independently represent a single bond, a carbonyl group, an ester, a phenylene group, a sulfonyl group or an amide group,

Z¹～Z⁴each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring.

12. A liquid crystal alignment film formed using the liquid crystal aligning agent according to any one of claims 1 to 11.

13. A liquid crystal display element comprising the liquid crystal alignment film according to claim 12.

14. A method of manufacturing a liquid crystal display element, comprising: a step of forming a coating film by applying the liquid crystal aligning agent according to any one of claims 1 to 11 to a substrate; firing the coating film; and a step of forming a liquid crystal layer by bringing the obtained fired film into contact with a liquid crystal composition.

15. A method of manufacturing a liquid crystal display element, comprising: a step of forming a coating film by applying the liquid crystal aligning agent according to any one of claims 1 to 11 to a substrate; firing the coating film; a step of bringing the fired film into contact with a liquid crystal composition containing a polymerizable compound to form a liquid crystal layer; and irradiating the liquid crystal layer with ultraviolet rays.

Technical Field

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

Background

Liquid crystal display elements are widely used in televisions, large monitors, personal computers, portable telephones, smart phones, and the like. In recent years, there have been increasing opportunities for using liquid crystal display elements under high temperature and high humidity conditions, such as car navigation devices, instruments, industrial equipment installed outdoors, and display units of measuring instruments, which are mounted on vehicles.

Among them, a liquid crystal display element of a vertical alignment system has been widely used in recent years because of its wide viewing angle, high response speed, and high contrast. For the vertical orientation mode, the following techniques are known: a photopolymerizable compound is added to a liquid crystal composition in advance, and the mixture is used together with a liquid crystal alignment film of polyimide or the like, and ultraviolet rays are irradiated while applying a voltage to a liquid crystal cell, thereby applying an inclination angle to the film surface and increasing the response speed of liquid crystal (see patent document 1 and non-patent document 1).

In order to promote the reaction of the photopolymerizable compound, a composition for a liquid crystal display element has been proposed which is used for forming at least either a liquid crystal layer or a liquid crystal alignment layer of a liquid crystal display element, and which contains a compound having a structure capable of exhibiting a chain transfer function (see patent document 2).

Documents of the prior art

Patent document

Patent document 1: international publication WO2011/132752

Patent document 2: japanese patent laid-open No. 2014-186301

Non-patent document

Non-patent document 1: hanaoka, SID04 DIGEST, P.1200-1202

Disclosure of Invention

Problems to be solved by the invention

However, the sulfide-based compound disclosed as a compound having a structure capable of exhibiting a chain transfer function contained in the composition for a liquid crystal display element in patent document 2 has a problem in handling because of strong odor, and thus has a problem in that it is industrially impossible to produce a large amount of the sulfide-based compound. In addition, benzyl isopropenyl ether, which is a vinyl ether group disclosed as a compound having a structure capable of exhibiting a chain transfer function, is a low molecular weight component, and an unreacted component remains in the liquid crystal alignment film, which may cause a display failure of the liquid crystal display element.

In recent years, as the quality of liquid crystal display elements has improved, the response speed of vertical alignment liquid crystal display elements has been required to be further increased, and the ability to efficiently react a photopolymerizable compound and impart a tilt angle has been required.

Means for solving the problems

The present invention has the following gist in response to the above requirement.

A liquid crystal aligning agent characterized by containing a polymer having a side chain represented by the following formula (1) and a side chain represented by the following formula (2).

(in the formula, R_1c、R_2cEach independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Y is_cRepresents a single bond or-CO-. Ar (Ar)¹Represents phenylene, naphthylene or biphenylene. T is_1c、T_2cEach independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃)CO-。A_cRepresents a single bond, an alkylene group having 1 to 20 carbon atoms which is optionally substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms, a 2-valent alicyclic group having 3 to 8 carbon atoms, or a 2-valent heterocyclic group selected from pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran and thiophene. n represents an integer of 1 to 4. Denotes the bonding position to the adjacent atom. )

(Q represents a group selected from the following formulas (Q-1) to (Q-4) (R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)₃represents-CH₂-, -NR-, -O-or-S-, -represents a bond to an adjacent carbon atom. ). R_1r、R_2rEach independently represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms, a benzyl group or a phenethyl group. Ar (Ar)²Represents a 2-valent aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, an organic group being optionally substituted thereon, and a hydrogen atom being optionally substituted with a halogen atom. T is_1r、T_2rEach independently represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH₂O-、-N(CH₃)-、-CON(CH₃) -or-N (CH)₃)CO-。A_rRepresents a single bond, an alkylene group having 1 to 20 carbon atoms which is optionally substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms, a 2-valent alicyclic group having 3 to 8 carbon atoms, or a 2-valent heterocyclic group selected from pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran and thiophene. Denotes the bonding position to the adjacent atom. )

ADVANTAGEOUS EFFECTS OF INVENTION

The liquid crystal display element having the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention has a wide viewing angle, a high response speed, and a large contrast.

Detailed Description

The liquid crystal aligning agent of the present invention contains a polymer having a side chain represented by the following formula (1) (hereinafter also referred to as a specific side chain 1) and a side chain represented by the following formula (2) (hereinafter also referred to as a specific side chain 2).

R in the above formula (1)_1c、R_2c、Y_c、Ar¹、T_1c、T_2c、A_cAnd n has the meaning described above.

Wherein R is_1c、R_2cEach independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, wherein R is preferably_1cAnd R_2cEach independently represents an alkyl group having 1 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, an isooctyl group, a 2-ethylhexyl group, a tert-octyl group, a nonyl group, an isononyl group, a decyl group, or an isodecyl group.

In addition, Ar¹Preferably phenylene or biphenylene. Preferably T_1c、T_2cEach independently is a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-or-CH₂O-。

A_cPreferably a single bond, an alkylene group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms or a 2-valent alicyclic group having 3 to 8 carbon atoms.

Further, n is preferably 1 to 2.

as-Ar in formula (1)¹-(Y_c-CHR_1cR_2c)_nAs the preferable structure of (B), there can be mentionedThe following (ch-1) to (ch-6).

(R_1c、R_2cThe same as in the above formula (1). )

Q, R in the above formula (2)_1r、R_2r、Ar²、T_1r、T_2r、A_rThe meaning of (a) is as described above.

Wherein Ar is²From the viewpoint of high photoreactivity, phenylene or biphenylene is preferable. Preferably T_1r、T_2rEach independently is a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-or-CH₂O-。

A_rPreferably a single bond, an alkylene group having 1 to 20 carbon atoms which may be substituted with a fluorine atom, a 2-valent aromatic ring group having 6 to 12 carbon atoms or a 2-valent alicyclic group having 3 to 8 carbon atoms.

R as a constituent of the above formula (1)_1c、R_2cR in the above formula (2)_1rAnd R_2rThe alkyl group having 1 to 10 carbon atoms may be any of a straight chain and a branched chain. Specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tert-octyl, nonyl, isononyl, decyl, isodecyl, cyclopentyl, cyclopentylmethyl, cyclopentylethyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl and the like.

A constituting the above formula (1)_cA in the above formula (2)_rThe alkylene group having 1 to 20 carbon atoms in (b) may be any of a straight chain, a branched chain and a cyclic chain. Specific examples thereof include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, 1-methyl-cyclopropylene, 2-methyl-cyclopropylene, 1-dimethyl-n-propylene, 1, 2-dimethyl-n-propylene, 2-dimethyl-n-propylene, 1-ethyl-n-propylene, 1, 2-dimethyl-cyclopropylene, 2, 3-dimethyl-cyclopropylene, 1-ethyl-cyclopropylene, 2-ethyl-cyclopropyleneYl-cyclopropylene, 1, 2-trimethyl-n-propylene, 1,2, 2-trimethyl-n-propylene, 1-ethyl-1-methyl-n-propylene, 1-ethyl-2-methyl-n-propylene, 2-n-propyl-cyclopropylene, 1-isopropyl-cyclopropylene, 2-isopropyl-cyclopropylene, 1,2, 2-trimethyl-cyclopropylene, 1,2, 3-trimethyl-cyclopropylene, 2,2, 3-trimethyl-cyclopropylene, 1-ethyl-2-methyl-cyclopropylene, 2-ethyl-1-methyl-cyclopropylene, 2-ethyl-2-methyl-cyclopropylene, 2-ethyl-3-methyl-cyclopropylene, and the like.

Among them, an alkylene group having 1 to 10 carbon atoms, more preferably 1 to 3 carbon atoms, is preferable, and specifically, a methylene group, an ethylene group, or an n-propylene group is preferable.

A constituting the above formula (1)_cA in the above formula (2)_rExamples of the aromatic cyclic group having 6 to 12 carbon atoms include a benzene ring, a biphenylene ring, and a naphthalene ring.

A constituting the above formula (1)_cA in the above formula (2)_rExamples of the alicyclic group having 3 to 8 carbon atoms include cyclopentane ring and cyclohexane ring.

as-Ar in formula (1)²-CO-CR_1rR_2rPreferred structures of Q include the formulae (ra-1) to (ra-6).

Among them, (ra-2) or (ra-3) is preferable from the viewpoint of reliability of the obtained liquid crystal display element.

The polymer contained in the liquid crystal aligning agent of the present invention may have a side chain represented by the following formula (3) (hereinafter, also referred to as a specific side chain 3) in addition to the specific side chain 1 and the specific side chain 2.

In the above formula (3), l, m and n each independently represent an integer of 0 or 1. R¹Is represented by- (CH)₂)_a- (a is an integer of 1 to 15), -CONH-),-NHCO-、-CON(CH₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-or- (CH)₂)_a1-A₁-(CH₂)_a2-A₂-，A₁Is oxygen atom or-COO- (-wherein a connecting bond of the bond and (CH) is attached₂)_a2Bonding) A₂Is oxygen atom or-COO- (wherein, a connecting bond of₂)_a2Bonding), a1 is an integer of 0 or 1, and a2 is an integer of 1-10.

In addition, R²、R³And R⁴Each independently represents a phenylene group, a fluorine-containing phenylene group or a cycloalkylene group. R⁵Represents a linear alkyl group having 2 to 24 carbon atoms, a fluoroalkyl group having 2 to 24 carbon atoms, an alkoxy group having 2 to 24 carbon atoms, an alkoxyalkyl group having 2 to 24 carbon atoms, or a structure having a steroid skeleton. Wherein R is⁵When the alkyl group is a linear alkyl group having 2 to 24 carbon atoms or a fluoroalkyl group having 2 to 24 carbon atoms, l + m + n is 1 or more, and when the alkyl group has a steroid skeleton, l, m, and n represent 0, R¹Is represented by- (CH)₂)_a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH)₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-.

Specific examples of the structure having a steroid skeleton include structures having a skeleton represented by the following formula (st).

Preferred structures of the specific side chain 3 include the following formulae (S1-x1) to (S1-x7) and (S3-x).

In the above formula, R¹Represents a linear alkyl group having 2 to 24 carbon atoms, an alkoxy group having 2 to 24 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. X^pIs represented by- (CH)₂)_a- (a is an integer of 1 to 15) -CONH-、-NHCO-、-CON(CH₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-. A. the₁Represents an oxygen atom or-COO- (wherein a connecting bond of the atom and (CH) is attached)₂)_a2Bonding) A₂Represents an oxygen atom or-COO- (wherein a connecting bond of₂)_a2Bonding) a₁、a₃Each independently is an integer of 0 or 1, a₂Is an integer of 1 to 10, and Cy represents a1, 4-cyclohexylene group or a1, 4-phenylene group.

In the above formulae, X represents the above formula (X1) or (X2). Col represents at least one selected from the group consisting of the formulas (Col1) to (Col 4). G represents the above formula (G1) or (G2). Denotes the position of bonding to other groups.

More preferable structures of the formula (S3-x) include the following formulae (S3-1) to (S3-6).

< specific Polymer >

The specific polymer contained in the liquid crystal aligning agent of the present invention may be a polymer containing a unit having a specific side chain 1 and a unit having a specific side chain 2 (hereinafter also referred to as a specific copolymer), or may be a mixture containing a polymer having a specific side chain 1 and a polymer having a specific side chain 2 (hereinafter also referred to as a polymer mixture).

The specific copolymer may further contain a unit having a specific side chain 3 in addition to the unit having the specific side chain 1 and the unit having the specific side chain 2. In addition, the polymer mixture may be a mixture containing a polymer having the specific side chain 1 and a polymer having the specific side chain 2, and any of the polymers may contain a unit having the specific side chain 3; or a mixture comprising a polymer having a specific side chain 1 and a polymer having a specific side chain 2 and a polymer having a specific side chain 3.

The specific copolymer may be a diamine having a specific side chain 1 and a polymer having a specific side chain 2, but is preferably a polymer having a skeleton selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and poly (meth) acrylate. Among these, a polyamide acid obtained by polycondensation reaction of a diamine component including a diamine having a specific side chain 1 and a diamine having a specific side chain 2 with a tetracarboxylic acid component and/or a polyimide obtained by imidizing the polyamide acid is preferable.

The content ratio of the unit having the specific side chain 1 and the unit having the specific side chain 2 in the specific copolymer is preferably 5/95 to 95/5, more preferably 10/90 to 90/10 in terms of molar ratio (specific side chain 1/specific side chain 2). When the ratio is within the above range, the light irradiation amount when the tilt is applied is reduced.

When the specific copolymer contains a unit having the specific side chain 3, the content ratio thereof is preferably 10/90 to 90/10, more preferably 10/90 to 80/20 in terms of a molar ratio (specific side chain 3/(specific side chain 1+ specific side chain 2)) to the total of the unit having the specific side chain 1 and the unit having the specific side chain 2. When the ratio is within the above range, the light irradiation amount when the liquid crystal alignment film is tilted while having high vertical alignment properties is reduced.

The polymer mixture is preferably a polymer containing a diamine component containing a diamine having a specific side chain 1, a polyamic acid formed by a polycondensation reaction with a tetracarboxylic acid component, and/or a polyimide formed by imidizing the polyamic acid; and a polymer mixture containing a diamine component containing a diamine having a specific side chain 2, a polyamic acid formed by a polycondensation reaction with a tetracarboxylic acid component, and/or a polyimide formed by imidizing the polyamic acid.

The content ratio of the polymer having the specific side chain 1 to the polymer having the specific side chain 2 in the polymer mixture is preferably 10/90 to 90/10, more preferably 20/80 to 80/20 in terms of weight ratio (polymer 1 having the specific side chain 1/polymer having the specific side chain 2). When the ratio is within the above range, the light irradiation amount when the tilt is applied is reduced.

When the specific polymer of the present invention, that is, the above specific copolymer or the above polymer mixture is obtained, a diamine having a specific side chain 1 used as a part of the raw material thereof is preferably a diamine represented by the following formula (d-1).

In the above formula (d-1), R_1c、R_2c、Y_c、Ar¹、T_1c、T_2c、A_cAnd n are the same as in the case of the above formula (1) and include preferred examples thereof. R_1cAnd R_2cThe case where both are methyl groups is particularly preferable from the viewpoint of availability of raw materials and the like.

Preferable specific examples of the diamine represented by the formula (d-1) include the following formulae (1-a) to (1-j).

When the specific polymer of the present invention, that is, the above specific copolymer or the above polymer mixture is obtained, as a preferred diamine having the specific side chain 2 used as a part of the raw material thereof, a diamine represented by the following formula (d-2) can be mentioned.

In the above formula (d-2), R_1r、R_2r、Y_r、Ar²、T_1r、T_2rAnd A_rThe meaning of (c) is the same as in the case of the above formula (2) and includes preferable examples thereof.

Preferable specific examples of the diamine represented by the formula (d-2) include the following formulas (2-a) to (2-d).

When the specific polymer of the present invention is a polymer having a side chain represented by the following formula (3) in addition to the side chain represented by the formula (1) and the side chain represented by the formula (2), a diamine represented by the following formula (d-3) is used as the diamine component in addition to the diamine represented by the formula (d-1) and the diamine represented by the formula (d-2).

In the above formula (d-3), l, m, n and R¹～R⁵The definitions of (b) are the same as those of the above formula (3) including preferred examples thereof. z represents an integer of 1 to 2, Y₃Is represented by the following formula (Ar)_3-1)～(Ar_3-2) The structure shown.

In the above formula, A_3aRepresents a single bond or a 2-valent organic group having an aromatic group. A. the_3bRepresents a 3-valent group having an aromatic group. 1 represents p-R¹-(R²)_l-(R³)_m-(R⁴)n-R⁵2 represents p-NH₂The bonding position of (2).

As A_3aThe 2-valent organic group having an aromatic group in (2) includes, for example, a structure represented by the following formula (R1).

*3-X₁-Q₁-*₂ (R1)

In the above formula, X₁Examples of the "C" group include a single bond, -O-, -C (CH)₃)₂-、-NH-、-CO-、-NHCO-、-COO-、-(CH₂)_m-、-SO₂-、-O-(CH₂)_m-O-、-O-C(CH₃)₂-、-CO-(CH₂)_m-、-NH-(CH₂)_m-、-SO₂-(CH₂)_m-、-CONH-(CH₂)_m-、-CONH-(CH₂)_m-NHCO-、-COO-(CH₂)_m-OCO-, etc. Q₁Examples thereof include groups obtained by removing 2 hydrogen atoms from aromatic hydrocarbons having 6 to 20 carbon atoms such as benzene rings and naphthalene rings. m is an integer of 1 to 8. 2 denotes p-NH₂And 3 represents a bonding position to a benzene ring.

As A_3bExamples of the 3-valent organic group having an aromatic group in (1) include structures represented by the following formula (R2).

In the above formula, X₂And X of the formula (R1)₁Synonymy, Q₂Examples thereof include groups obtained by removing 3 hydrogen atoms from aromatic hydrocarbons having 6 to 20 carbon atoms such as benzene rings and naphthalene rings. 1 represents p-R¹-(R²)_l-(R³)_m-(R⁴)_n-R⁵2 represents p-NH₂And 3 represents a bonding position to a benzene ring.

As a preferred example of the diamine represented by the above formula (d-3), diamines of the following formulae (V-1) to (V-13) can be mentioned.

In the above formula, X^v1～X^v4、X^p1～X^p8Each independently represents- (CH)₂)_a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH)₃)-、-NH-、-O-、-CH₂O-、-CH₂OCO-, -COO-or-OCO-. X^V6～X^V7、X^s1～X^s4Each independently represents-O-, -COO-or-OCO-. X_a～X_fRepresents a single bond, -O-, -NH-or-O- (CH)₂)_m-O-。R^v1～R^v4、R^1a～R^1hEach independently represents a linear alkyl group having 2 to 24 carbon atoms, an alkoxy group having 2 to 24 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. m represents an integer of 1 to 8.

As the diamine component in obtaining the specific polymer, other diamines (hereinafter also referred to as other diamines) may be used in combination in addition to the diamine represented by the formula (d-1), the diamine represented by the formula (d-2) and the diamine represented by the formula (d-3).

Specifically, there may be mentioned diamines described in paragraph [0169] of International publication No. WO2015/046374, diamines described in paragraphs [0171] to [0172] having a carboxyl group and a hydroxyl group, diamines described in paragraphs [0173] to [0188] having a nitrogen-containing heterocycle, diamines described in paragraph [0050] of Japanese patent laid-open No. 2016-218149, diamines described in International publication No. WO2017/126627 having an azole structure, and preferably diamines having a structure represented by the following formula (pr)

(R¹Represents a hydrogen atom, hydrogen, a fluorine atom, a cyano group, a hydroxyl group, a methyl group, R²Each independently represents a single bond or 1-R³-Ph-*2，R³Represents a single bond selected from-O-, -COO-, -OCO-, - (CH)₂)l-、-O(CH₂)_m2-valent organic groups (l and m each represents an integer of 1 to 5) in O-, -CONH-, and-NHCO-, -1 represents a position bonded to the benzene ring in the formula (pr), and 2 represents a position bonded to the amino group in the formula (pr). Ph represents a phenylene group. n represents 1 to 3. ) A

The diamine having an azole structure described in International publication WO2018/062197, preferably a diamine having a structure represented by the following formula (pn)

(R¹、R²Represents a hydrogen atom or a methyl group, R³Each independently represents a single bond or 1-R⁴-Ph-*2，R⁴Represents a single bond selected from-O-, -COO-, -OCO-, - (CH)₂)_l-、-O(CH₂)_mAnd 2-valent organic groups (l and m each represents an integer of 1 to 5) in O-, -CONH-, and-NHCO-, wherein 1 represents a position bonded to a benzene ring in the formula (pn) and 2 represents a position bonded to an amino group in the formula (pn). Ph represents a phenylene group. n represents 1 to 3. ) A

The diamine having a thiophene or furan structure described in International publication WO2018/092759, preferably a diamine having a structure represented by the following formula (sf)

(Y¹Represents a sulfur atom or an oxygen atom, R²Each independently represents a single bond or 1-R⁵-Ph-*2，R⁵Represents a single bond selected from-O-, -COO-, -OCO-, - (CH)₂)_l-、-O(CH₂)_mAnd 2-valent organic groups (l and m each represents an integer of 1 to 5) in O-, -CONH-, and-NHCO-, wherein 1 represents a position bonded to a benzene ring in the formula (pn) and 2 represents a position bonded to an amino group in the formula (pn). Ph represents a phenylene group. n represents 1 to 3. ) A

The diamine having a carbazole structure described in International publication WO2018/110354, preferably a diamine having a structure represented by the following formula (cz)

(R¹Represents a hydrogen atom or a methyl group, R²Represents a methyl group. ) A

An organosiloxane-containing diamine such as 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane or 1, 3-bis (4-aminobutyl) -1,1,3, 3-tetramethyldisiloxane, a diamine having a functional group capable of forming a covalent bond by light irradiation (also referred to as a photoreactive group) described in international publication WO2015/033921 for increasing the response speed of a liquid crystal when forming a liquid crystal display element, a diamine having a benzophenone skeleton represented by the following formula (z1) or (z2), or the like.

Specific examples of the diamine having a benzophenone skeleton include 3,3 ' -diaminobenzophenone, 3,4 ' -diaminobenzophenone, 4 ' -bis [4- (4-amino- α, α -dimethylbenzyl) phenoxy ] benzophenone, diamines represented by the following formulae (z-1) to (z-4), and the like.

Further, as the other diamine, there may be mentioned other diamines having a structure represented by the following formula (11).

Wherein A is a single bond or a 2-valent organic group, R₁、R₂And R₃Each independently represents a hydrogen atom or a 1-valent organic group having 1 to 20 carbon atoms.

In the formula (11), A is a single bond or a 2-valent organic group. The structure of the 2-valent organic group is represented by, for example, the following formula (12).

*-R₅-B-R₆-* (12)

In the formula, B is a 2-valent linking group, R₅And R₆Each independently represents a single bond or a C1-20, preferably C1-10, 2-valent hydrocarbon group. Specific examples of B include-CH₂-、-CHR₇-、-CR₇R₈-、-CR₇＝CR₈-、-C≡C-、-O-、-S-、-NR₉-、-C(＝O)O-、-OC(＝O)-、-C(＝O)NR₁₀-、-NR₁₀C(＝O)-、-NR₁₀C(＝O)NR₁₁However, the present invention is not limited thereto.

R is as defined above₇、R₈、R₉、R₁₀And R₁₁Each independently represents a hydrogen atom or a C1-20 hydrocarbon group. Examples of the 1-valent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, butyl, tert-butyl, hexyl, octyl and decyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; bicycloalkyl such as bicyclohexyl; alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, isopropenyl and hexenyl; aryl groups such as phenyl, xylyl, biphenyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylcyclohexyl.

Some or all of the hydrogen atoms of these 1-valent hydrocarbon groups may be substituted with a halogen atom, a hydroxyl group, a mercapto group, a carboxyl group, a thioester group, an amide group, an alkyl group, a cycloalkyl group, a bicycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, or the like.

If R is₇、R₈、R₉、R₁₀And R₁₁In the case of a bulky structure such as an aromatic ring or an alicyclic structure, the solubility of the polymer may be lowered, and therefore, an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a hydrogen atom is preferable, and a hydrogen atom is more preferable.

R in the formula (11)₁、R₂And R₃Each independently represents a hydrogen atom or a 1-valent organic group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. Examples of the 1-valent organic group include a 1-valent hydrocarbon group, a hydroxyl group, a mercapto group, an ester group, a carboxyl group, a thioester group, an amide group, an organoxy group, an organosilyl group, an organosulfur group, and an acyl group. The 1-valent organic group is preferably a 1-valent hydrocarbon group in view of high resistance to high temperature and high humidity. Specific examples of the 1-valent hydrocarbon group include the 1-valent hydrocarbons described above, and some or all of the hydrogen atoms of these 1-valent hydrocarbon groups may be substituted by the R₇、R₈、R₉、R₁₀The compound (b) may be substituted with a group such as a pyrrolyl group, an imidazolyl group or a pyrazolyl group.

AsR₁And R₂From the viewpoint of high resistance to high temperature and high humidity, an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a hydrogen atom is preferable, and a hydrogen atom is more preferable.

As R₃From the viewpoint of high resistance to high temperature and high humidity, an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a hydrogen atom is preferable, and a hydrogen atom is more preferable.

Specific examples of the structure represented by formula (11) are particularly preferably the structures represented by the following formulae (H-1) to (H-6).

n1, n2, n3, n4, n5 and n6 independently represent an integer of 1 to 10.

The diamine having the structure represented by the formula (11) is preferably a diamine represented by the following formula (M1) from the viewpoint of high resistance to high temperature and high humidity of the liquid crystal alignment film.

Z₁Is a substituent having a structure represented by the formula (11), and n is an integer of 1 to 4. Y is₁Is an (n +2) -valent organic group having 5 to 40 carbon atoms.

As the aforementioned Y₁Examples of the (n +2) -valent organic group having 5 to 40 carbon atoms in the (a) chain include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and the like, a group obtained by introducing a functional group such as-O-, -COO-, -OCO-, -CO-, -NHCO-, -S-, -NH-, a 2-valent heterocycle, a 2-valent group containing a steroid skeleton, and the like into a carbon-carbon bond in the hydrocarbon group, and a (n +2) -valent heterocycle. Each of these groups may have a substituent such as a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), an alkoxy group, or the like.

Here, the (n +2) -valent chain hydrocarbon group may be represented by R₇、R₈、R₉、R₁₀And R₁₁Wherein the 1-valent alkyl group is one obtained by removing (n +1) hydrogen atomsAnd a group obtained by removing (n +1) hydrogen atoms from the 1-valent alkenyl group. The (n +2) -valent alicyclic hydrocarbon group may be represented by the formula R₇、R₈、R₉、R₁₀And R₁₁The group (b) in (3) is a group obtained by removing (n +1) hydrogen atoms from the 1-valent cycloalkyl group, a group obtained by removing (n +1) hydrogen atoms from the 1-valent bicycloalkyl group, or the like. The (n +2) -valent aromatic hydrocarbon group may be represented by R₇、R₈、R₉、R₁₀And R₁₁The group (b) in (3) is a group obtained by removing (n +1) hydrogen atoms from the 1-valent aryl group, a group obtained by removing (n +1) hydrogen atoms from the 1-valent aralkyl group, or the like.

Examples of the 2-valent heterocyclic ring include a 5-membered heterocyclic ring such as a 2-valent pyrrole ring, a 2-valent thiophene ring, a 2-valent furan ring, or a pyrrolidinylene group, and a 6-membered heterocyclic ring such as a piperidylene group, a piperazinyl group, a pyridylene group, a pyridazinylene group, or a pyrimidylene group.

The steroid skeleton has a skeleton represented by the following formula (st) in which 3 6-membered rings and 1 5-membered rings are bonded.

Y₁From the viewpoint of high resistance to high temperature and high humidity of the liquid crystal alignment film, an (n +2) -valent organic group having 5 to 40 carbon atoms, specifically an (n +2) -valent aromatic hydrocarbon group having 5 to 40 carbon atoms, a group obtained by introducing a functional group such as-O-, -COO-, -OCO-, -CO-, -NHCO-, -S-, -NH-, a 2-valent heterocycle or a 2-valent group having a steroid skeleton into a carbon-carbon bond in the hydrocarbon group, or an (n +2) -valent group having an aromatic heterocycle is preferable.

Y₁In the (n +2) -valent group having an aromatic heterocyclic ring in (2), the aromatic heterocyclic ring is preferably a nitrogen-containing aromatic heterocyclic ring having a nitrogen atom in the ring portion. Specific examples thereof include a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, and a triazine ring, and a pyridine ring, a pyrimidine ring, and a triazine ring are more preferable.

As Y₁From the viewpoint of high voltage holding ratioIn view of this, the aromatic hydrocarbon group is preferably an (n +2) -valent aromatic hydrocarbon group having 5 to 40 carbon atoms, preferably having the following formula (Ar)₁) The structure is a (n +2) -valent group having 5 to 40 carbon atoms.

A₁Represents a single bond or a 2-valent organic group having an aromatic ring.

More preferred specific examples of the formula (M1) include the following formulae (M1-1) to (M1-13).

Z₁The structure of formula (11) is shown in the specification, c is an integer of 1-4, d and e are integers of 1-2, and n is an integer of 2-6.

From the viewpoint of improving the vertical orientation, the diamine having the structure represented by the formula (11) is preferably at least one selected from the group consisting of diamines represented by the following formulae (M-1) to (M-6).

n1, n2, n3, n4, n5 and n6 independently represent an integer of 1 to 10.

Further, as the other diamine, a diamine having a structure represented by the following formula (21) may be mentioned.

In the above formula (21), R¹Represents hydrogen or a monovalent organic group, and represents a site bonded to other groups.

The diamine having an oxazoline skeleton represented by the above formula (21) includes diamines selected from the group represented by the following formulae (21-1) to (21-3).

In the above formulae (21-1) to (21-3), R¹The definition of (c) is the same as in the above formula (21). R²Represents a group selected from the group consisting of a single bond, -O-, -COO-, -OCO-, - (CH)₂)_l-、-O(CH₂)_lO-、-CONR¹¹-、-NR¹¹CO-and-NR¹¹A 2-valent organic group consisting of a combination of the bonds in (A) and (B), W¹Represents a structure selected from the following group (3-1), W²Represents a structure selected from the following group (3-2), W³Represents a structure selected from the following group (3-3), W⁴Represents a structure selected from the following groups (3-4). Herein, R is¹¹Represents hydrogen or a monovalent organic group, l represents an integer of 1 to 12, and a represents an integer of 0 or 1.

In the above group (3-1).)₁Represents a site bonded to an amino group in the formulae (21-1) to (21-3)₂Represents a site bonded to an oxazoline ring. Group (3-2)₁Represents a site bonded to an amino group in the formulae (21-1) to (21-3)₃Is represented by the formula²The site of bonding. Group (3-3).)₃Is represented by the formula²The site of bonding. In group (3-4).)₂Represents a site bonded to an oxazoline ring. X represents a substituent, and represents a hydrogen atom; a halogen atom; alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl and propyl; a C1-6 haloalkyl group such as a trifluoromethyl group; substituted amino groups such as dimethylamino group; alkoxy groups having 1 to 6 carbon atoms such as methoxy and ethoxy; NHCOCH₃、NHCOCH₂CH₃Amide groups such as NHCOOtBu. tBu represents a tert-butyl group.

Specific examples of the diamines of the formulae (21-1) to (21-3) include the following.

In the above formula, R¹The definition of (b) is the same as that in the above formula (21), and a hydrogen atom, a methyl group (Me) or an ethyl group (Et) is particularly preferable. R¹¹The definition of (3) is the same as that in the above formula (21), and a hydrogen atom, a Me group or an Et group is particularly preferable. n represents an integer of 1 to 6, and m represents an integer of 1 to 12.

Specific examples of the diamine component which may be used in combination with the above-mentioned other diamines include m-phenylenediamine, p-phenylenediamine, 4 '-diaminobiphenyl, 3' -dimethyl-4, 4 '-diaminobiphenyl, 3' -difluoro-4, 4 '-diaminobiphenyl, 4' -diaminodiphenylmethane, 4 '-diaminodiphenyl ether, 4' -diaminodiphenylamine, N-methyl (4,4 '-diaminodiphenyl) amine, 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, and the like, 1, 4-bis (4-aminophenoxy) benzene, 1, 4-bis (4-aminophenyl) benzene, 1, 3-bis (4-aminophenyl) benzene, 1, 4-bis (4-aminobenzyl) benzene, 1, 3-bis (4-aminophenoxy) benzene, 4 ' - [1, 4-phenylenebis (methylene) ] diphenylamine, 1, 4-phenylenebis [ (4-aminophenyl) methanone ], 1, 4-phenylenebis (4-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (4-aminophenyl) isophthalate, N ' - (1, 4-phenylene) bis (4-aminobenzamide), N ' -bis (4-aminophenyl) terephthalamide, N, N '-bis (4-aminophenyl) isophthalamide, 9, 10-bis (4-aminophenyl) anthracene, 2' -bis [4- (4-aminophenoxy) phenyl ] propane, 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, 1, 10-bis (4-aminophenoxy) decane, 2' -bis (4-aminophenyl) anthracene, 1, 4-aminophenoxy) butane, 1, 5-bis (4-aminophenoxy) pentane, 1,6-, Bis (4-aminocyclohexyl) methane, 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 5-diaminopentane, 1, 6-diaminohexane, 2, 4-diaminobenzoic acid, 2, 5-diaminobenzoic acid or 3, 5-diaminobenzoic acid, 4 '-diaminobiphenyl-3-carboxylic acid, 4' -diaminodiphenylmethane-3-carboxylic acid, 4 '-diaminodiphenylethane-3-carboxylic acid, 4' -diaminobiphenyl-3, 3 '-dicarboxylic acid, 4' -diaminobiphenyl-2, 2 '-dicarboxylic acid, 3' -diaminobiphenyl-4, 4 '-dicarboxylic acid, 3' -diaminobiphenyl-2, 4 ' -dicarboxylic acid, 4 ' -diaminodiphenylmethane-3, 3 ' -dicarboxylic acid, 4 ' -diaminodiphenylethane-3, 3 ' -dicarboxylic acid, 4 ' -diaminodiphenyl ether-3, 3 ' -dicarboxylic acid, 2, 6-diaminopyridine, 3, 4-diaminopyridine, 2, 4-diaminopyrimidine, 3, 6-diaminocarbazole, N-methyl-3, 6-diaminocarbazole, 1, 4-bis- (4-aminophenyl) -piperazine, 3, 6-diaminoacridine, N-ethyl-3, 6-diaminocarbazole, N-phenyl-3, 6-diaminocarbazole, N ' -bis (4-aminophenyl) -benzidine, N-methyl-3, 6-diaminocarbazole, N ' -diaminocarbazole, N-methyl-3, 6-diaminocarbazole, N-methyl, N, N '-bis (4-aminophenyl) -N, N' -dimethylbenzidine, compounds represented by the following formulae (D-2-1) to (D-2-23), and diamines in which the amino group is a secondary amino group.

The other diamines may be used in a mixture of 1 or 2 or more depending on the solubility of the specific polymer in a solvent, the coating property of a liquid crystal aligning agent, the liquid crystal aligning property in forming a liquid crystal alignment film, the voltage holding ratio, and the properties such as accumulated charge.

As the tetracarboxylic acid component for obtaining the specific polymer of the present invention, tetracarboxylic dianhydrides represented by the following formulae [4] to [6] are preferably used. In this case, not only the tetracarboxylic dianhydrides represented by the formulae [4] to [6] but also tetracarboxylic acids, tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters or tetracarboxylic acid dialkyl ester dihalides as the tetracarboxylic acid derivatives thereof can be used.

Z¹Is selected from the following [4a ]]～[4k]At least one structure of (1). Formula [5]]Or formula [6]Wherein j and k are each independently0 or 1. x and y are each independently a single bond, carbonyl, ester, phenylene, sulfonyl, or amide.

Formula [4a ]]In, Z¹～Z⁴Represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring, and may be the same or different. As formula [4a]As a preferred example of (3), the following [4a-1] can be mentioned]、[4a-2]The structure of (1).

Formula [4g ]]In, Z⁵And Z⁶Represents a hydrogen atom or a methyl group, and may be the same or different.

Among Z in formula [4], tetracarboxylic dianhydrides having a structure represented by formula [4a ], formula [4c ] to formula [4g ] or formula [4k ] and tetracarboxylic acid derivatives thereof are preferable from the viewpoints of ease of synthesis and ease of polymerization reactivity in the production of a polymer. More preferably a tetracarboxylic dianhydride having a structure represented by the formula [4a ] or the formulae [4e ] to [4g ] and a tetracarboxylic acid derivative thereof. Particularly preferred are tetracarboxylic dianhydrides having a structure represented by the formula [4a ], the formula [4e ] or the formula [4f ] and tetracarboxylic acid derivatives thereof. More preferred examples thereof include tetracarboxylic dianhydrides having a structure represented by the formula [4a-1], the formula [4a-2], the formula [4e ] or the formula [4f ] and tetracarboxylic acid derivatives thereof.

From the viewpoint of suppressing the charge accumulation in the liquid crystal display element, preferable specific examples of the formula [5] or [6] include tetracarboxylic dianhydrides represented by the following formulas (5a-1) to (5a-5) and (6 a-1).

The tetracarboxylic acid component represented by the formula [4] is preferably 1 to 100 mol% based on 100 mol% of the total tetracarboxylic acid components used. Among these, 5 to 95 mol% is preferable, and 20 to 80 mol% is more preferable.

The tetracarboxylic acid component may be used in a mixture of 1 or 2 or more depending on the solubility of the specific polymer in a solvent, the coating property of a liquid crystal aligning agent, the liquid crystal aligning property in forming a liquid crystal alignment film, the voltage holding ratio, the accumulated charge, and other properties.

The polyimide-based polymer of the specific polymer may contain a tetracarboxylic acid component other than the specific tetracarboxylic acid component.

Examples of the other tetracarboxylic acid component include tetracarboxylic acids, tetracarboxylic dianhydrides, tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides shown below.

That is, as other tetracarboxylic acid components, 1,2,5, 6-naphthalenetetracarboxylic acid, 1,4,5, 8-naphthalenetetracarboxylic acid, 1,2,5, 6-anthracenetetracarboxylic acid, bis (3, 4-dicarboxyphenyl) methane, 2-bis (3, 4-dicarboxyphenyl) propane, bis (3, 4-dicarboxyphenyl) dimethylsilane, bis (3, 4-dicarboxyphenyl) diphenylsilane, 2,3,4, 5-pyridinetetracarboxylic acid, 2, 6-bis (3, 4-dicarboxyphenyl) pyridine, 3,4,9, 10-perylenetetracarboxylic acid or 1, 3-diphenyl-1, 2,3, 4-cyclobutanetetracarboxylic acid, and the like can be cited.

< method for producing specific Polymer >

The polyimide precursor as the specific polymer in the present invention is obtained by reacting a diamine component and a tetracarboxylic acid component. Specifically, a method of obtaining a polyamic acid by polycondensation of a tetracarboxylic dianhydride and a primary diamine or a secondary diamine; a method of obtaining a polyamic acid by dehydrating and polycondensing a tetracarboxylic acid and a primary diamine or a secondary diamine; or a method of polycondensing a tetracarboxylic acid dihalide and a primary diamine or a secondary diamine to obtain a polyamic acid.

The specific polymer can be obtained by reacting the tetracarboxylic acid component and the diamine component as described above together 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. The 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 component and the diamine component used.

A method of polycondensing tetracarboxylic acid obtained by dialkylesterifying a carboxylic acid group with a primary diamine or a secondary diamine to obtain a polyamic acid alkyl ester; a method of polycondensing a tetracarboxylic acid dihalide obtained by dialkylesterifying a carboxylic acid group with a primary diamine or a secondary diamine; or a method of converting the carboxyl group of the polyamic acid into an ester.

The reaction of the diamine component and the tetracarboxylic acid component is usually carried out in a solvent. The solvent used in this case is not particularly limited as long as it is a solvent in which the polyimide precursor to be produced is dissolved. Specific examples of the solvent used in the reaction are shown below, but the solvent is not limited to these examples.

Examples thereof include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ -butyrolactone, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide or 1, 3-dimethyl-2-imidazolidinone. When the polyimide precursor has high solubility in the solvent, a solvent represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or a solvent represented by the following formulae [ D-1] to [ D-3] can be used.

Formula [ D-1]In (D)¹Represents an alkylene group having 1 to 3 carbon atoms of the formula [ D-2 ]]In (D)²Represents an alkylene group having 1 to 3 carbon atoms, formula [ D-3]]In (D)³Represents an alkylene group having 1 to 4 carbon atoms.

These solvents may be used alone or in admixture thereof. Further, even in the case of a solvent which does not dissolve the polyimide precursor, the solvent may be mixed and used within a range where the produced polyimide precursor is not precipitated. Further, since the water content in the solvent causes inhibition of the polymerization reaction and hydrolysis of the polyimide precursor formed, it is preferable to use a dehydrated and dried solvent as the solvent.

When the diamine component and the tetracarboxylic acid component are reacted in a solvent, the reaction may be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a polymer having a high molecular weight, and if the concentration is too high, the viscosity of the reaction solution is too high to uniformly stir, and therefore, the concentration is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. The reaction may be carried out at a high concentration at the initial stage of the reaction and then a solvent may be added.

In the polymerization reaction of the polyimide precursor, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably 0.8 to 1.2. Similarly to the ordinary polycondensation reaction, the molecular weight of the polyimide precursor to be produced increases as the molar ratio approaches 1.0.

The polyimide of the present invention is obtained by ring-closing the polyimide precursor, and the ring-closing ratio of the amic acid group (also referred to as imidization ratio) in the polyimide is not necessarily 100%, and can be arbitrarily adjusted depending on the application and purpose.

As the polyimide as the specific polymer in the present invention, a method of ring-closing polyamic acid or polyamic acid alkyl ester as a polyimide precursor is used.

Examples of the method for imidizing the polyimide precursor include thermal imidization in which a solution of the polyimide precursor is directly heated, and catalytic imidization in which a catalyst is added to a solution of the polyimide precursor.

The temperature at which the polyimide precursor is thermally imidized in a solution is 100 to 400 ℃, preferably 120 to 250 ℃, and it is preferable that the thermal imidization is carried out while removing water generated by the imidization reaction from the system.

The catalyst 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 the mixture at-20 to 250 ℃, preferably 0 to 180 ℃. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times, by mole the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to 30 times, by mole the amount of the amic acid group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, and among them, pyridine is preferable because it has a suitable basic property for the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride, and among these, acetic anhydride is preferable because purification after completion of the reaction is easy. The imidization rate by the catalyst imidization can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the 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 put into a solvent to precipitate. Examples of the solvent used for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by adding the solvent may be dried at normal temperature or under reduced pressure or dried by heating after filtration and recovery. Further, when the operation of re-dissolving the polymer recovered by precipitation in the solvent and performing re-precipitation recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the solvent in this case include alcohols, ketones, hydrocarbons, and the like, and the use of 3 or more solvents selected from these is preferable because the purification efficiency is further improved.

The polyimide precursor and the polyimide preferably have a weight average molecular weight (Mw) of 1000 to 500000, more preferably 2000 to 300000, in terms of polyethylene oxide as measured by Gel Permeation Chromatography (GPC). The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polyethylene oxide measured by GPC is preferably 15 or less, more preferably 10 or less. When the molecular weight is within such a range, good alignment properties of the liquid crystal display element can be ensured.

< liquid Crystal Aligning agent >

The liquid crystal aligning agent of the present invention is a coating solution for forming a liquid crystal alignment film, and is a coating solution for forming a liquid crystal alignment film containing a specific polymer and a solvent. The specific polymer may be any polyimide-based polymer selected from polyamic acids, polyamic acid alkyl esters, and polyimides.

All polymers in the liquid crystal aligning agent of the present invention may be specific polymers, or other polymers may be mixed. Examples of the other polymers include polyimide polymers having no specific side chain 1, specific side chain 2, and specific side chain 3. Further, cellulose polymers, acrylic polymers, methacrylic polymers, polystyrene, polyamide, polysiloxane, and the like can be cited. In this case, the content of the other polymer is preferably 5 to 90 parts by mass, more preferably 10 to 60 parts by mass, based on 100 parts by mass of the polymer in which the specific polymer and the other polymer are combined.

The content of the solvent in the liquid crystal aligning agent of the present invention is preferably 70 to 99.9 mass%. The content may be appropriately changed depending on the method of applying the liquid crystal aligning agent and the target film thickness of the liquid crystal alignment film.

The solvent used in the liquid crystal aligning agent of the present invention is not particularly limited as long as it is a solvent for dissolving a polymer (also referred to as a good solvent). Specific examples of the good solvent are listed below, but the solvent is not limited to these examples.

Examples thereof include N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, dimethyl sulfoxide, γ -butyrolactone, γ -valerolactone, 1, 3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, methyl ethyl ketone, cyclohexanone, cyclopentanone, and 4-hydroxy-4-methyl-2-pentanone.

Among them, preferred is N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, γ -butyrolactone, γ -valerolactone, 1, 3-dimethyl-2-imidazolidinone, 3-methoxy-N, N-dimethylpropionamide or 3-butoxy-N, N-dimethylpropionamide.

Further, when the solubility of the polymer in the solvent is high, it is preferable to use solvents represented by the above-mentioned formulae [ D-1] to [ D-3 ].

The good solvent in the liquid crystal aligning agent of the present invention is preferably 5 to 99% by mass of the total solvent contained in the liquid crystal aligning agent. Among them, it is preferably 10 to 90% by mass.

The liquid crystal aligning agent of the present invention may use a solvent (also referred to as a poor solvent) that improves the film coatability and surface smoothness of the liquid crystal alignment film when the liquid crystal aligning agent is applied. Specific examples of the poor solvent are given below, but the poor solvent is not limited to these examples.

Examples thereof include ethanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentanol, tert-pentanol, 3-methyl-2-butanol, neopentanol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1, 2-ethanediol, 1, 2-propanediol, isobutanol, 2-butanol, 2-pentanol, 2-methyl-1-pentanol, 2-methyl-, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 2, 3-butanediol, 1, 5-pentanediol, 2-methyl-2, 4-pentanediol, 2-ethyl-1, 3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1, 2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-butanediol, 2, 3-butanediol, 1, 3-pentanediol, 1, 5-pentanediol, 2, 5-pentanediol, 2-methyl 2-butanediol, 2, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, a solvent represented by the formulae [ D-1] to [ D-3], or propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, 1- (butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, Dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionate, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl acetate, ethyl propionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-methoxypropionate, propylene glycol monomethyl ether, Methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, 4-hydroxy-4-methyl-2-pentanone, etc.

Of these, 1-hexanol, cyclohexanol, 1, 2-ethylene glycol, 1, 2-propylene glycol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, propylene glycol diacetate, dipropylene glycol monomethyl ether, or propylene carbonate are preferable.

The poor solvent is preferably 1 to 95% by mass of the total solvent contained in the liquid crystal aligning agent. Among them, it is preferably 10 to 90% by mass.

The liquid crystal aligning agent of the present invention can use a compound that improves the uniformity of the film thickness and the surface smoothness of the liquid crystal alignment film when the liquid crystal aligning agent is applied.

Examples of the compound for improving the uniformity of the film thickness and the surface smoothness of the liquid crystal alignment film include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant. More specifically, there may be mentioned EFTOP EF301, EF303, EF352 (Tochem Products Co., Ltd., above), Megaface F171, F173, R-30 (Dainippon Ink Co., Ltd., above), Fluorad FC430, FC431 (Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (Asahi Niger Co., Ltd., above).

The amount of the surfactant is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of the total polymer components contained in the liquid crystal aligning agent.

Further, as a compound which promotes charge transfer in the liquid crystal alignment film and promotes charge release of the element, a nitrogen-containing heterocyclic amine represented by the formulae [ M1] to [ M156] described in paragraphs [0194] to [0200] of International publication No. WO2011/132751, more preferably a nitrogen-containing heterocyclic amine represented by the following formulae (B-1) to (B-40), may be added to the liquid crystal alignment agent of the present invention. The amine may be added directly to the liquid crystal aligning agent, but is preferably added after forming a solution with a concentration of 0.1 to 10%, preferably 1 to 7%, with an appropriate solvent. The solvent is not particularly limited as long as it dissolves the polyimide polymer.

Further, the liquid crystal aligning agent of the present invention may contain a crosslinkable compound as a compound for crosslinking a specific polymer, and an adhesion promoter for improving adhesion between the liquid crystal alignment film and the substrate and adhesion between the liquid crystal alignment film and the sealing material.

(crosslinkable Compound)

The crosslinkable compound is preferably introduced with at least one compound selected from the group consisting of crosslinkable compounds having a substituent selected from at least one of an epoxy group, an isocyanate group, an oxetanyl group, a cyclocarbonate group, a blocked isocyanate group, a hydroxyl group and an alkoxy group, and crosslinkable compounds having a polymerizable unsaturated group.

From the viewpoint of improving the crosslinkability, it is preferable that these substituents and polymerizable unsaturated bonds have 2 or more in the crosslinkable compound. Specific examples of the crosslinkable compound include a compound having an epoxy group or an isocyanate group, a compound having an oxetanyl group, an amino resin having a hydroxyl group, an alkoxy group or a lower alkoxyalkyl group, a benzene or phenol compound having a hydroxyl group or an alkoxy group, a compound having a cyclocarbonate group, a compound having a hydroxyalkylamide group, a compound having a blocked isocyanate group, and the like, which are described in paragraphs [0169] to [0190] of international publication No. 2011/132751, and international publication No. 2012/014898.

Preferable specific examples of the crosslinkable compound include compounds represented by the following formulas (CL-1) to (CL-11).

The content of the crosslinkable compound is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the total polymer components contained in the liquid crystal aligning agent, and more preferably 0.1 to 50 parts by mass, and even more preferably 1 to 50 parts by mass, from the viewpoint of improving the alignment property of the liquid crystal.

(Advance adjuvant)

Examples of the adhesion promoter include functional silane compounds. Examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureylpropyltrimethoxysilane, 3-ureylpropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, N-trisilylpropyltriethylenetriamine, N-trisilyl-3-aminopropyltriethoxysilane, N-trisilobutyltrimethoxysilane, N, 10-trimethoxysilyl-1, 4, 7-triazacyclodecane, 10-triethoxysilyl-1, 4, 7-triazacyclodecane, 9-trimethoxysilyl-3, 6-diaza-nonyl acetate, 9-triethoxysilyl-3, 6-diaza-nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, n-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane. When these adhesion promoters are used, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the total polymer components contained in the liquid crystal aligning agent. If the amount is less than 0.1 part by mass, the effect of improving the adhesion cannot be expected, and if the amount is more than 30 parts by mass, the alignment property of the liquid crystal may be deteriorated.

In the liquid crystal aligning agent of the present invention, in addition to the poor solvent, the crosslinkable compound, the adhesion promoter, the compound for improving the uniformity of the film thickness and the surface smoothness of the resin coating film or the liquid crystal alignment film, and the compound for promoting charge release, a dielectric or a conductive material for changing electrical characteristics such as a dielectric constant, conductivity, and the like of the liquid crystal alignment film may be added.

< 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 by applying it to a substrate, baking it, and then performing alignment treatment such as rubbing treatment or light irradiation. In the case of vertical alignment applications, the liquid crystal alignment film can be used without alignment treatment.

The liquid crystal alignment film of the present invention can be used for a liquid crystal alignment film of a horizontal alignment type or a vertical alignment type (VA system, PSA mode, SC-PVA mode, etc.), and among them, is suitable for a liquid crystal display element of a vertical alignment type such as PSA mode, SC-PVA mode, etc., and can control a pretilt with a small amount of light irradiation.

The substrate used in this case is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as an acrylic substrate or a polycarbonate substrate may be used in addition to a glass substrate. From the viewpoint of process simplification, a substrate on which an ITO electrode or the like for driving liquid crystal is formed is preferably used. In the reflective liquid crystal display element, a single-sided substrate may be used, and an opaque substrate such as a silicon wafer may be used.

The method of applying the liquid crystal aligning agent is not particularly limited, and a method using screen printing, offset printing, flexo printing, an ink jet method, or the like is generally industrially used. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spin coater method, a spray coating method, and the like, and they can be used according to the purpose.

After coating the liquid crystal aligning agent on the substrate, the solvent is evaporated at a temperature of 30 to 300 ℃, preferably 30 to 250 ℃ depending on the solvent used in the liquid crystal aligning agent by a heating means such as a hot plate, a thermal cycle type oven or an IR (infrared ray) type oven, thereby forming a liquid crystal alignment film. The thickness of the liquid crystal alignment film after firing is preferably 5 to 300nm, more preferably 10 to 100nm, because it is disadvantageous in terms of power consumption of the liquid crystal display element if it is too thick, and because it is likely to lower the reliability of the liquid crystal display element if it is too thin. When the liquid crystal is aligned horizontally or obliquely, the liquid crystal alignment film after firing is treated by rubbing, polarized ultraviolet irradiation, or the like.

In the liquid crystal display element of the present invention, a substrate with a liquid crystal alignment film is obtained from the liquid crystal alignment agent of the present invention by the above-described method, and then a liquid crystal cell is produced by a known method to form the liquid crystal display element.

As a method for manufacturing a liquid crystal cell, a method in which a pair of substrates on which liquid crystal alignment films are formed are prepared, spacers are scattered on the liquid crystal alignment film of one substrate, the other substrate is bonded with the liquid crystal alignment film surface facing the inside, and liquid crystal is injected under reduced pressure and sealed; or a method of dropping liquid crystal on the liquid crystal alignment film surface on which the spacer is dispersed, and then bonding the substrates to seal them.

Further, the liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element produced by a step of providing a liquid crystal layer between a pair of substrates having electrodes, disposing a liquid crystal composition containing a polymerizable compound that is polymerized by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with the active energy rays and heat while applying a voltage between the electrodes. Here, as the active energy ray, ultraviolet rays are suitable. The ultraviolet ray has a wavelength of 300 to 400nm, preferably 310 to 360 nm. When the polymerization is carried out by heating, the heating temperature is 40 to 120 ℃, preferably 60 to 80 ℃. In addition, ultraviolet rays and heating may be performed simultaneously.

The liquid crystal display element controls the pretilt of liquid crystal molecules by a Polymer Stabilized Alignment (PSA) method. In the PSA method, a small amount of a photopolymerizable compound, for example, a photopolymerizable monomer, is mixed into a liquid crystal material in advance, a liquid crystal cell is assembled, and then the photopolymerizable compound is irradiated with ultraviolet light or the like while a predetermined voltage is applied to the liquid crystal layer, whereby the pretilt of liquid crystal molecules is controlled by the produced polymer. Since the alignment state of the liquid crystal molecules when the polymer is produced is stored even after the voltage is removed, the pretilt of the liquid crystal molecules can be adjusted by controlling an electric field or the like formed in the liquid crystal layer. In addition, the PSA method does not require rubbing treatment, and is therefore suitable for formation of a vertical alignment liquid crystal layer in which it is difficult to control the pretilt by rubbing treatment.

That is, in the liquid crystal display element of the present invention, after a substrate with a liquid crystal alignment film is obtained from the liquid crystal alignment agent of the present invention by the above-described method, a liquid crystal cell is produced, and the polymerizable compound is polymerized by at least one of irradiation with ultraviolet light and heating, whereby the alignment of liquid crystal molecules can be controlled.

As an example of the PSA type liquid crystal cell fabrication, a method in which a pair of substrates on which liquid crystal alignment films are formed are prepared, spacers are scattered on the liquid crystal alignment film of one substrate, the other substrate is bonded with the liquid crystal alignment film facing the inside, and liquid crystal is injected under reduced pressure and sealed; or a method of dropping liquid crystal on the liquid crystal alignment film surface on which the spacer is dispersed, and then bonding the substrates to seal them.

The liquid crystal is mixed with a polymerizable compound that is polymerized by heat or ultraviolet irradiation. Examples of the polymerizable compound include compounds having 1 or more polymerizable unsaturated groups such as an acrylate group and a methacrylate group in the molecule. In this case, the polymerizable compound is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 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 polymerizable compound is not polymerized and alignment control of the liquid crystal cannot be performed, and when the amount is more than 10 parts by mass, the amount of the unreacted polymerizable compound increases and the afterimage characteristic of the liquid crystal display element is deteriorated.

After the liquid crystal cell is produced, the polymerizable compound is polymerized by applying an ac or dc voltage to the liquid crystal cell and irradiating the liquid crystal cell with heat or ultraviolet light. Thereby, the orientation of the liquid crystal molecules can be controlled.

The liquid crystal aligning agent of the present invention is also preferably used in an SC-PVA mode, which is a liquid crystal display element manufactured by disposing a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between a pair of substrates provided with electrodes, and applying a voltage between the electrodes. Here, as the active energy ray, ultraviolet rays are suitable. The ultraviolet ray has a wavelength of 300 to 400nm, preferably 310 to 360 nm. When the polymerization is carried out by heating, the heating temperature is 40 to 120 ℃, preferably 60 to 80 ℃. In addition, ultraviolet rays and heating may be performed simultaneously.

In order to obtain a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat, a method of adding a compound containing the polymerizable group to a liquid crystal aligning agent; a method of using a polymerizable group-containing polymer component. Specific examples of the polymerizable group-containing polymer include, but are not particularly limited to, polymers having the photoreactive group, and polymers obtained using a diamine having the photoreactive group.

As an example of the production of the SC-PVA mode liquid crystal cell, there is a method in which a pair of substrates on which the liquid crystal alignment film of the present invention is formed is prepared, spacers are scattered on the liquid crystal alignment film of one substrate, the other substrate is bonded with the liquid crystal alignment film surface facing the inside, and the liquid crystal is injected under reduced pressure and sealed; or a method of dropping liquid crystal on the liquid crystal alignment film surface on which the spacer is dispersed, and then bonding the substrates to seal them.

After the liquid crystal cell is fabricated, the liquid crystal cell is irradiated with heat or ultraviolet rays while applying an ac or dc voltage to the liquid crystal cell, whereby the alignment of liquid crystal molecules can be controlled.

Examples

The present invention is not limited to the examples, but the present invention is explained below by way of example.

The abbreviations used hereinafter have the following meanings.

(acid dianhydride)

BODA: bicyclo [3,3,0] octane-2, 4,6, 8-tetracarboxylic dianhydride

CBDA: 1,2,3, 4-cyclobutanetetracarboxylic dianhydride

(diamine)

p-PDA: p-phenylenediamine, DBA: 3, 5-diaminobenzoic acid

3, AMPDA: 3, 5-diamino-N- (pyridin-3-ylmethyl) benzamide

(solvent)

NMP: n-methyl-2-pyrrolidone, BCS: butyl cellosolve

(additives)

3AMP (3 AMP): 3-aminomethylpyridines

< preparation of liquid Crystal alignment agent >

(example 1)

BODA (1.13g, 4.5 mmol), DA-1(0.60g, 1.8 mmol), DA-3(0.65g, 2.7 mmol) and DA-4(1.71g, 4.5 mmol) were dissolved in NMP (16.3g), reacted at 60 ℃ for 3 hours, then CBDA (0.86g, 4.5 mmol) and NMP (3.4g) were added, and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

To the polyamic acid solution (19.3g) was added NMP to dilute the solution to 6 mass%, and then acetic anhydride (3.6g) and pyridine (1.1g) were added as imidization catalysts to react at 80 ℃ for 3 hours. The reaction solution was poured into methanol (220ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain a polyimide powder (A). The imidization rate of this polyimide was 77%.

NMP (25.4g) was added to the obtained polyimide powder (A) (3.2g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 3.2g of 3AMP (1 wt% NMP solution) and BCS (21.2g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent (A1).

(example 2)

BODA (1.13g, 4.5 mmol), DA-1(0.59g, 1.8 mmol), DA-2(0.67g, 2.7 mmol) and DA-4(1.71g, 4.5 mmol) were dissolved in NMP (16.4g) and reacted at 60 ℃ for 3 hours, then CBDA (0.86g, 4.5 mmol) and NMP (3.4g) were added and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

To the polyamic acid solution (16.4g) was added NMP to dilute the solution to 6 mass%, and then acetic anhydride (2.9g) and pyridine (0.9g) were added as imidization catalysts to react at 80 ℃ for 3 hours. The reaction solution was poured into methanol (190ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain polyimide powder (B). The imidization ratio of this polyimide was 78%.

NMP (21.3g) was added to the obtained polyimide powder (B) (2.7g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 2.7g of 3AMP (1 wt% NMP solution) and BCS (17.8g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent (B1).

(example 3)

BODA (2.25g, 9.0 mmol), DA-1(0.60g, 1.8 mmol), DA-3(1.74g, 7.2 mmol) and DA-4(3.43g, 9.0 mmol) were dissolved in NMP (32.1g), reacted at 60 ℃ for 3 hours, then CBDA (1.76g, 9.0 mmol) and NMP (6.8g) were added, and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

To the polyamic acid solution (15.0g) was added NMP to dilute the solution to 6 mass%, and then acetic anhydride (2.8g) and pyridine (0.9g) were added as imidization catalysts to react at 80 ℃ for 3 hours. The reaction solution was poured into methanol (174ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain polyimide powder (C). The imidization rate of this polyimide was 77%.

NMP (20.3g) was added to the obtained polyimide powder (C) (2.5g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 2.5g of 3AMP (1 wt% NMP solution) and BCS (16.9g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent (C1).

(example 4)

BODA (2.25g, 9.0 mmol), DA-1(0.60g, 1.8 mmol), DA-2(1.79g, 7.2 mmol) and DA-4(3.43g, 9.0 mmol) were dissolved in NMP (32.3g), reacted at 60 ℃ for 3 hours, then CBDA (1.76g, 9.0 mmol) and NMP (6.8g) were added, and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

After NMP was added to the polyamic acid solution (15.0g) to dilute the solution to 6 mass%, acetic anhydride (2.8g) and pyridine (0.9g) were added as imidization catalysts, and the mixture was reacted at 75 ℃ for 2.5 hours. The reaction solution was poured into methanol (174ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain a polyimide powder (D). The imidization rate of this polyimide was 69%.

NMP (19.7g) was added to the obtained polyimide powder (D) (2.5g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 2.5g of 3AMP (1 wt% NMP solution) and BCS (16.4g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent (D1).

Comparative example 1

BODA (25.6g, 102.5 mmol), DA-1(13.5g, 41.0 mmol), p-PDA (6.7g, 61.5 mmol) and DA-4(39.0g, 102.5 mmol) were dissolved in NMP (339.4g) and reacted at 60 ℃ for 3 hours, then CBDA (18.9g, 96.3 mmol) (75.6g) was added and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

NMP was added to the polyamic acid solution (260.0g) to dilute the solution to 6 mass%, and acetic anhydride (52.3g) and pyridine (16.2g) were added as imidization catalysts to react at 80 ℃ for 3 hours. The reaction solution was poured into methanol (3040ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain polyimide powder (E). The imidization rate of this polyimide was 70%.

NMP (28.6g) was added to the obtained polyimide powder (E) (3.6g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 3.6g of 3AMP (1 wt% NMP solution) and BCS (23.8g), and the mixture was stirred at room temperature for 5 hours to obtain a liquid crystal aligning agent (E1).

Comparative example 2

BODA (2.50g, 10.0 mmol), DA-1(0.66g, 2.0 mmol), p-PDA (0.87g, 8.0 mmol) and DA-4(3.80g, 8.0 mmol) were dissolved in NMP (31.3g), reacted at 60 ℃ for 3 hours, then CBDA (1.88g, 9.6 mmol) and NMP (7.5g) were added, and reacted at 40 ℃ for 12 hours to obtain a polyamic acid solution.

To the polyamic acid solution (15.0g) was added NMP to dilute the solution to 6 mass%, and then acetic anhydride (3.1g) and pyridine (1.0g) were added as imidization catalysts to react at 80 ℃ for 3 hours. The reaction solution was poured into methanol (175ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure at 60 ℃ to obtain polyimide powder (F). The imidization rate of this polyimide was 69%.

NMP (21.3g) was added to the obtained polyimide powder (F) (2.7g), and the mixture was stirred at 70 ℃ for 12 hours to dissolve the powder. To the solution were added 2.7g of 3AMP (1 wt% NMP solution) and BCS (17.8g), and the mixture was stirred at room temperature for 5 hours, thereby obtaining a liquid crystal aligning agent (F1).

< preparation of liquid Crystal cell and measurement of Pre-Tilt Angle >

(example 5)

A liquid crystal cell was produced by the following procedure using the liquid crystal aligning agent (a1) obtained in example 1. The liquid crystal aligning agent (A1) obtained in example 1 was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern having a pixel size of 100. mu. m × 300. mu.m and a line pitch of 5 μm was formed, and dried on a hot plate at 80 ℃ for 90 seconds, and then fired in a hot air circulation oven at 230 ℃ for 15 minutes to form a liquid crystal alignment film having a thickness of 100 nm.

Further, a liquid crystal aligning agent (A1) was spin-coated on the ITO surface on which no electrode pattern was formed, dried on a hot plate at 80 ℃ for 90 seconds, and then fired in a hot air circulating oven at 230 ℃ for 15 minutes to form a liquid crystal alignment film having a film thickness of 100 nm.

For the above 2 substrates, after spreading 4 μm bead spacers on the liquid crystal alignment film of one substrate, a sealant (solvent-based thermosetting type epoxy resin) was printed thereon. Then, the other substrate is bonded to the former substrate with the surface of the other substrate on which the liquid crystal alignment film is formed being the inner side, and then the sealant is cured to produce an empty cell. Liquid crystal MLC-3023 (trade name (liquid crystal containing polymerizable compound) manufactured by Merck ltd) was injected into the empty cell by a reduced pressure injection method to manufacture a liquid crystal cell.

Then, in a state where a DC voltage of 15V was applied to the liquid crystal cell, the voltage was set to 10J/cm from the outside of the liquid crystal cell²UV through a band pass filter of 365nm was irradiated. Then, the pretilt angle of the pixel portion was measured for the cell after UV irradiation. The measurement was carried out using an LCD analyzer LCA-LUV42A manufactured by Meiryo technical Corporation. The results are shown in Table 1.

(examples 6 to 12, comparative examples 3 to 6)

A liquid crystal cell was produced in the same manner as in example 5 except that the liquid crystal aligning agent shown in table 1 obtained in examples 1 to 4 or comparative example 1 or 2 was used instead of the liquid crystal aligning agent (a1) in example 5 and UV irradiation was performed under the following conditions, and the pretilt angle of the liquid crystal cell after UV irradiation was measured in the same manner as in example 5.

As shown in Table 1, the UV irradiation was performed at 20J/cm in examples 6,8, 10 and 12 and comparative examples 4 and 6²。

The results of measurement of the pretilt angle are summarized in the table.

[ Table 1]

As shown in Table 1, it was confirmed that the tilt angle of the liquid crystal cell was smaller in examples 5 to 8 than in comparative examples 3 to 4 and in examples 9 to 12 than in comparative examples 5 to 6, and that the tilt applying ability was improved by using the liquid crystal display element of the present invention.

Industrial applicability

The liquid crystal display element having the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention has a wide viewing angle, a high response speed, and a large contrast, and thus can be suitably used for a large-screen and high-definition television, a large-size monitor, and the like.

The entire contents of the specification, patent claims and abstract of japanese patent application No. 2018-202179 filed on 26.10.2018 are incorporated herein by reference as the disclosure of the specification of the present invention.