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

Abstract

The invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a liquid crystal display element. The diamine is characterized in that the diamine is represented by the following formula [II]. # imgabs0 # in formula [II], Z2 is selected from the group consisting of formulae [Z-1] to [Z-4], [Z-6], and [Z-7]; * represents a bond, # imgabs1 #

Description

[0001] This application is a divisional application of the following application:

[0002] Invention name: liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element.

[0003] International filing date: September 16, 2020.

[0004] International application number: PCT / JP2020 / 035095.

[0005] National application number: 202080055417.1. Technical Field

[0006] The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element. Background Art

[0007] In the past, liquid crystal devices have been widely used as display units for personal computers, smart phones, mobile phones, televisions, etc. Liquid crystal devices include, for example: a liquid crystal layer sandwiched between an element substrate and a color filter substrate; pixel electrodes and common electrodes for applying an electric field to the liquid crystal layer; an orientation film for controlling the orientation of liquid crystal molecules in the liquid crystal layer; and a thin film transistor (TFT: Thin Film Transistor) for switching the electrical signal supplied to the pixel electrode. As a driving method for liquid crystal molecules, known are longitudinal electric field methods such as TN (Twisted Nematic) method and VA (Vertical Alignment) method; and transverse electric field methods such as IPS (In-Plane Switching) method and fringe field switching (hereinafter referred to as FFS: Fringe Field Switching) method (for example, Patent Document 1).

[0008] In the transverse electric field method, which generally forms electrodes only on one side of a substrate and applies an electric field in a direction parallel to the substrate, it is known as a liquid crystal display element having a wide viewing angle characteristic and capable of high-quality display, compared with the existing longitudinal electric field method in which a voltage is applied to electrodes formed on upper and lower substrates to drive liquid crystals. As a method for orienting liquid crystals in a certain direction, there is a method of performing a so-called brushing treatment, which is also widely used in industry, in which a polymer film such as polyimide is formed on a substrate and the surface is rubbed with a cloth.

[0009] The liquid crystal alignment film, which is a component of the liquid crystal display element, is a film used to uniformly align the liquid crystal, but it requires not only the uniformity of the orientation of the liquid crystal, but also various characteristics. For example, there are problems such as the accumulation of charges in the liquid crystal alignment film due to the voltage driving the liquid crystal, and these accumulated charges may disturb the orientation of the liquid crystal, or affect the display as residual images or afterimages (hereinafter referred to as afterimages derived from residual DC), which significantly reduces the display quality level of the liquid crystal display element. Therefore, a liquid crystal alignment agent that overcomes these problems has been proposed (Patent Document 2).

[0010] In addition, economic efficiency in the production process is very important, so it is also necessary to make the element substrate easy to recycle. That is, it is required that after the liquid crystal alignment film is formed by the liquid crystal alignment agent, when the orientation is inspected and defects are generated, the liquid crystal alignment film can be removed from the substrate and the rework process of the recovered substrate can be simply implemented.

[0011] However, since adhesion with a base is required for a liquid crystal aligning film, a liquid crystal aligning film having necessary adhesion can be produced and a liquid crystal aligning agent which can easily perform a reprocessing step is required.

[0012] Prior art literature

[0013] Patent Literature

[0014] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-167782

[0015] Patent Document 2: International Publication No. 02 / 33481 Pamphlet Summary of the invention

[0016] Problems to be solved by the invention

[0017] In view of such circumstances, an object of the present invention is to provide a liquid crystal aligning agent capable of producing a liquid crystal aligning film having required performance including adhesion and having good reworkability, and a liquid crystal aligning film and a liquid crystal display element produced from the liquid crystal aligning agent.

[0018] Solutions for solving problems

[0019] The present inventors have conducted intensive studies and have found that good residual characteristics and high reliability can be ensured by introducing a diamine having a specific side chain structure as a diamine component together with a specific diamine having an imide skeleton, thereby completing the present invention.

[0020] A liquid crystal alignment agent of the present invention for achieving the above-mentioned purpose is characterized in that it comprises a polymer obtained from a diamine component and an organic solvent, wherein the diamine component comprises: at least one first diamine represented by the following formula [I]; and at least one second diamine having a side chain structure selected from the group represented by the following formulas [S1] to [S3].

[0021]

[0022] (In formula [I], Z 1 Selected from the following formulas [Z-1] to [Z-9]. * represents a bonding bond. )

[0023]

[0024] (In formula [S1], X 1 and X 2 Each independently represents a single bond, -(CH2) a -(a represents an integer of 1 to 15.), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -(a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1s and A1s each independently have the above definition). 1 and G 2 Each independently represents a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group is optionally substituted by at least one selected from the group consisting of an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. m and n are each independently an integer of 0 to 3, and the total of m and n is 1 to 6, preferably 1 to 4. R 1 represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 1 Any hydrogen atom of is optionally substituted by a fluorine atom. )

[0025] -X 3 —R 2 [S2]

[0026] (In formula [S2], X 3 R represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -COO- or -OCO-. 2represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 2 Any hydrogen atom of is optionally substituted by a fluorine atom. )

[0027] -X 4 -R 3 [S3]

[0028] (In formula [S3], X 4 Indicates -CONH-, -NHCO-, -O-, -COO- or -OCO-. 3 Indicates a structure with a steroidal skeleton.)

[0029] Effects of the Invention

[0030] According to the present invention, a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element can be provided in which the accumulated charge is quickly relaxed and the reliability is improved, and in particular, the reliability after high-temperature and high-humidity aging is improved. DETAILED DESCRIPTION

[0031] Hereinafter, the present invention will be described in detail.

[0032] The liquid crystal aligning agent of the present invention comprises a polymer obtained from a diamine component and an organic solvent. The diamine component comprises a first diamine having a structure represented by the above formula [I] and a second diamine compound having a side chain structure represented by the above formulas [S1] to [S3]. First, the diamine will be described.

[0033] <First diamine>

[0034] The first diamine has a structure represented by the following formula [I].

[0035]

[0036] (In formula [I], Z 1 As defined in formula [I] above.)

[0037] In formula [I], the position of the amino group is preferably the para position or the meta position as in the following formula [I-1] or [I-2]. 1 Selected from the following formulas [Z-1] to [Z-9]. * represents a bonding bond.

[0038]

[0039]

[0040] The first diamine of the present invention can be obtained by reducing a dinitro compound to convert a nitro group into an amino group. The method for reducing the dinitro compound is not particularly limited, and the following method can be exemplified: palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum carbon sulfide, etc. are used as catalysts, and the reduction is carried out in a solvent such as ethyl acetate, toluene, tetrahydrofuran, dioxane, alcohol, etc., by hydrogen, hydrazine, hydrogen chloride, etc. If necessary, it can also be carried out under pressure using an autoclave, etc.

[0041] The first diamine compound of the present invention thus obtained can be used as a raw material for polyimide precursors such as polyamic acid and polyamic acid ester, polyimide, polyurea, polyamide, etc. (collectively referred to as "polymers"). The polymer can be dissolved in a predetermined organic solvent and used as a liquid crystal aligning agent, and its use is not limited.

[0042] In addition, among the above-mentioned 1st diamine, the diamine represented by the following formula [II] is a novel compound.

[0043]

[0044] (In formula [II], Z 2 Selected from the following formulas [Z-1] to [Z-4], [Z-6] and [Z-7]. * represents a bonding bond. )

[0045]

[0046] In formula [II], the position of the amino group is preferably the para position or the meta position as described in formula [I-1] or [I-2]. In this case, in formula [I-1] or [I-2], Z 1 It is preferably selected from the above formulas [Z-1] to [Z-4], [Z-6] and [Z-7].

[0047] <Second diamine having a specific side chain structure>

[0048] The second diamine having a specific side chain structure is a substance that exhibits vertical alignment and has at least one side chain structure selected from the group represented by the following formulas [S1] to [S3]. Hereinafter, as examples of the second diamine having the specific side chain structure, diamines having specific side chain structures represented by formulas [S1] to [S3] are described in order.

[0049] [A]: A diamine having a specific side chain structure represented by the following formula [S1].

[0050]

[0051] In the above formula [S1], X 1 and X 2 Each independently represents a single bond, -(CH2)a -(a represents an integer of 1 to 15.), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -(a1 is an integer of 1 to 15, A1 represents an oxygen atom or -COO-, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1s and A1s each independently have the above definition).

[0052] Among them, from the perspective of raw material availability and ease of synthesis, X 1 and X 2 Each independently is preferably a single bond, -(CH2) a -(a represents an integer of 1 to 15), -O-, -CH2O- or -COO-, and more preferably a single bond, -(CH2) a -(a represents an integer of 1 to 10), -O-, -CH2O- or -COO-.

[0053] In addition, in the above formula [S1], G 1 and G 2 Each independently represents a divalent cyclic group selected from the group consisting of a divalent aromatic group having 6 to 12 carbon atoms and a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group is optionally substituted by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. m and n each independently represent an integer of 0 to 3, and the total of m and n is 1 to 6, preferably 1 to 4.

[0054] In the above formula [S1], R 1 represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. 1 Any hydrogen atom of the group may be substituted with a fluorine atom. Examples of divalent aromatic groups having 6 to 12 carbon atoms include phenylene, biphenylene structure, naphthylene, etc. Examples of divalent alicyclic groups having 3 to 8 carbon atoms include cyclopropylene, cyclohexylene, etc.

[0055] Therefore, as preferred specific examples of the above formula [S1], the following formulas [S1-x1] to [S1-x7] can be listed.

[0056]

[0057] In the above formulas [S1-x1] to [S1-x7], R 1 The same as the case of the above formula [S1].p Indicates - (CH2) a -(a represents an integer of 1 to 15.), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-. A1 represents an oxygen atom or -COO-*(the bond with "*" and (CH2) a2 A2 represents an oxygen atom or *-COO- (the bond with "*" is connected to (CH2) a2 a3 represents an integer of 0 or 1, and a1 and a2 each independently represent an integer of 2 to 10. Cy represents a 1,4-cyclohexylene group or a 1,4-phenylene group.

[0058] [B]: A diamine having a specific side chain structure represented by the following formula [S2].

[0059] -X 3 -R 2 [S2]

[0060] In the above formula [S2], X 3 represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -COO- or -OCO-. In view of the liquid crystal orientation of the liquid crystal aligning agent, X 3 Preferred is -CONH-, -NHCO-, -O-, -CH2O-, -COO- or -OCO-.

[0061] In the above formula [S2], R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. 2 Any hydrogen atom of R is optionally substituted by a fluorine atom. 2 An alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms is preferred.

[0062] As a preferred specific example of formula [S2], X 3 is any of -O-, -CH2O-, -COO- or -OCO-, preferably R 2 In the case of an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, R 2 In the case of an alkyl group having 3 to 20 carbon atoms, R 2 Any hydrogen atom of is optionally substituted by a fluorine atom.

[0063] [C]: a diamine having a specific side chain structure represented by the following formula [S3].

[0064] —X 4 —R 3 [S3]

[0065] In the above formula [S3], X 4 Indicates -CONH-, -NHCO-, -O-, -COO- or -OCO-. 3 The steroid skeleton herein includes a skeleton represented by the following formula (st) in which three six-membered rings and one five-membered ring are bonded.

[0066]

[0067] Examples of the above formula [S3] include the following formula [S3-x]. e Represents methyl.

[0068]

[0069] In the above formula [S3-x], X represents the above formula [X1] or [X2]. In addition, Col represents any group selected from the group consisting of the above formulas [Col1] to [Col3], and G represents any group selected from the group consisting of the above formulas [G1] to [G4]. * represents a site bonded to another group.

[0070] Examples of preferred combinations of X, Col and G in the formula [S3-x] include the following combinations: [X1], [Col1] and [G1]; [X1], [Col1] and [G2]; [X1], [Col2] and [G1]; [X1], [Col2] and [G2]; [X1], [Col3] and [G2]; [X1], [Col3] and [G1]; [X2], [Col1] and [G2]; [X2], [Col2] and [G2]; [X2], [Col2] and [G1]; [X2], [Col3] and [G2]; [X2], [Col1] and [G1].

[0071] In addition, specific examples of the above formula [S3] include: a structure in which the hydroxyl group is removed from the steroid compound described in paragraph

[0024] of Japanese Patent Application Laid-Open No. 4-281427, a structure in which the acyl chloride group is removed from the steroid compound described in paragraph

[0030] of the same publication, a structure in which the amino group is removed from the steroid compound described in paragraph

[0038] of the same publication, a structure in which the halogen atom is removed from the steroid compound described in paragraph

[0042] of the same publication, and structures described in paragraphs

[0018] to

[0022] of Japanese Patent Application Laid-Open No. 8-146421.

[0072] It should be noted that, as a representative example of a steroid skeleton, cholesterol (a combination of [Col1] and [G2] in the above formula [S3-x]) can be cited, but a steroid skeleton that does not contain the cholesterol can also be used. That is, as a diamine having a steroid skeleton, for example, 3,5-diaminobenzoic acid cholesteryl ester can be cited, but it can also be set as a diamine component that does not contain a diamine having the cholesterol skeleton. In addition, as a diamine having a specific side chain structure, a diamine that does not contain an amide bond at the connecting position of the diamine and the side chain can also be used. In this embodiment, even if a diamine component that does not contain a diamine having a cholesterol skeleton is used, a liquid crystal alignment film that can ensure a high voltage retention rate for a long time and a liquid crystal alignment agent for a liquid crystal display element can be provided.

[0073] The diamine having a side chain structure represented by the above formulas [S1] to [S3] is preferably at least one selected from the diamines represented by the following formulas [1] and [2].

[0074]

[0075] (In formula [1], Y represents a monovalent group selected from the side chain structures represented by the above formulas [S1] to [S3]. In formula [2], X represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -(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-, -CONH-, -NH-(CH2) m -NH-, or -SO2-(CH2) m -SO2-. m is an integer of 1 to 8. Two Ys each independently represent a monovalent group selected from the side chain structures represented by the above formulas [S1] to [S3].

[0076] Preferred specific examples of the diamine represented by the formula [1] include diamines represented by the structures of the following formulas [1-S1] to [1-S3]. Specific examples of the diamine represented by the formula [2] are described in the diamine having a specific side chain structure of a di-side chain type that exhibits vertical alignment properties, which will be described later.

[0077]

[0078] In the above formula [1-S1], X 1 , X 2 , G 1 , G 2 , R 1 , m and n are the same as those in the above formula [S1]. In the above formula [1-S2], X 3 and R 2 The same as in the above formula [S2]. In the above formula [1-S3], X 4 and R 3 The same as in the above formula [S3].

[0079] (Diamine having a two-side chain type specific side chain structure exhibiting vertical alignment)

[0080] The diamine having a di-side chain type specific side chain structure that exhibits vertical alignment properties is represented by the above formula [2].

[0081] In the above formula [2], X preferably represents a single bond, -O-, -NH-, or -O-(CH2) m -O-.

[0082] In the above formula [2], Y may be at the meta position or the ortho position relative to X, but is preferably at the ortho position. That is, the above formula [2] is preferably the following formula [1′].

[0083]

[0084] In the above formula [2], the positions of the two amino groups (-NH2) may be any positions on the benzene ring, but are preferably positions shown in the following formulas [1]-a1 to [1]-a3, and more preferably in the following formula [1]-a1. In the following formula, X is the same as in the above formula [2]. It should be noted that the following formulas [1]-a1 to [1]-a3 illustrate the positions of the two amino groups, and the expression of Y shown in the above formula [2] is omitted.

[0085]

[0086] Therefore, based on the above formulas [1′] and [1]-a1 to [1]-a3, the above formula [2] is preferably any structure selected from the group consisting of the following formulas [1]-a1-1 to [1]-a3-2, and more preferably a structure represented by the following formula [1]-a1-1. In the following formulas, X and Y are the same as in the above formula [2].

[0087]

[0088] In addition, as examples of the above formulas [S1] to [S3], the following formulas [S]-1 to [S]-20 can be listed. Among them, as examples of the above formula [S1], the following formulas [S]-1 to [S]-4, [S]-8 or [S]-10 are preferred. It should be noted that in the following formulas, * represents the bonding position with the phenyl group in the above formulas [1], [1'] and [1]-a1 to [1]-a3. In addition, in [S]-1 to [S]-20, n is an integer of 1 to 20, and m is an integer of 1 to 6.

[0089]

[0090] The diamine component contains two side chain diamines having a specified structure, and thus the liquid crystal alignment film is not easily reduced in the ability to orient the liquid crystal vertically even when overheating is performed. In addition, the diamine component contains the two side chain diamines, and thus the liquid crystal alignment film is not easily reduced in the ability to orient the liquid crystal vertically even when the film is damaged by contact with a foreign object. That is, the diamine component contains the two side chain diamines, and thus a liquid crystal alignment agent that can obtain a liquid crystal alignment film having various excellent characteristics can be provided.

[0091] In the present embodiment, when the diamine component includes the first diamine and the second diamine, the content of the first diamine is preferably 10 to 90 mol% of the total diamine component, and more preferably 20 to 80 mol%. In addition, the content of the second diamine is preferably 10 to 90 mol%, and more preferably 20 to 80 mol%. When other diamines described later are included, the total content of the first diamine and the second diamine is preferably 95 mol% or less, and more preferably 90 mol% or less.

[0092] <Other diamines: diamines having photoreactive side chains>

[0093] The diamine component of the present embodiment may contain a diamine having a photoreactive side chain as another diamine. When the diamine component contains a diamine having a photoreactive side chain, a photoreactive side chain can be introduced into a specific polymer or other polymers.

[0094] Specific examples of the diamine having a photoreactive side chain include, for example, the diamines described in paragraphs

[0124] to

[0132] of Japanese Patent Re-examination No. 2016-140328, but are not limited thereto.

[0095] As more preferable specific examples, the following formulas (a-1) to (a-4) can be mentioned.

[0096]

[0097] (X 9 , X10 Each independently represents a bonding group that is a single bond, -O-, -COO-, -NHCO-, or -NH-, and Y represents an alkylene group having 1 to 20 carbon atoms that is optionally substituted with a fluorine atom.

[0098] These diamines having photoreactive side chains can be used alone or in combination of two or more. Depending on the liquid crystal orientation, pretilt angle, voltage holding characteristics, stored charge and other characteristics when made into a liquid crystal alignment film, the response speed of the liquid crystal when made into a liquid crystal display element, etc., one type can be used alone or in combination of two or more types. In addition, when two or more types are mixed, their ratios can be appropriately adjusted.

[0099] In the present embodiment, when the diamine component contains a photoreactive side chain diamine, the photoreactive side chain diamine is preferably 10 to 70 mol %, more preferably 10 to 60 mol % of the total diamine component.

[0100] <Other diamines: diamines other than those mentioned above>

[0101] Other diamines which may be contained in the diamine component for obtaining the specific polymer are not limited to the above-mentioned diamines having a photoreactive side chain.

[0102] In the case of producing a polyimide precursor and / or a polyimide, other diamines other than the above diamines may be used as diamine components as long as the effect of the present invention is not impaired. Specifically, for example, diamines described in paragraph

[0135] of Japanese Patent Re-publication No. WO2016-140328, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, diamines represented by the following formulas (z-1) to (z-18), diamines having a radical initiating function such as the following formulas (R1) to (R5), and diamines having a group "-N(D)-" (D represents a protective group that is detached and substituted by a hydrogen atom by heating, preferably a tert-butyloxycarbonyl group) such as the following formulas (5-1) to (5-11).

[0103]

[0104]

[0105] (In the formula, n is an integer from 2 to 10.)

[0106]

[0107] Preferred specific examples of the diamine described in paragraph

[0135] of the above-mentioned Japanese Patent Re-publication No. WO2016-140328 are shown below.

[0108] p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3 , 3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenylamine, 3,3'-sulfonyldiphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-Bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebismethylene]diphenylamine, 4,4'-[1,3-phenylenebismethylene]diphenylamine, 3,4'-[1,4-phenylenebismethylene]diphenylamine, 3,4'-[1,3-phenylenebismethylene]diphenylamine, 3,3'-[1,4-phenylenebismethylene]diphenylamine, 3,3'-[1,3-phenylenebismethylene]diphenylamine, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[ [3-aminophenyl) ketone], 1,4-phenylene bis(4-aminobenzoate), 1,4-phenylene bis(3-aminobenzoate), 1,3-phenylene bis(4-aminobenzoate), 1,3-phenylene bis(3-aminobenzoate), bis(4-aminophenyl) terephthalate, bis(3-aminophenyl) terephthalate, bis(4-aminophenyl) isophthalate, bis(3-aminophenyl) isophthalate, N,N'-(1,4-phenylene) bis(4-aminobenzamide), N,N'-(1,3-phenylene) bis(4-aminobenzamide), N,N'-(1,4-phenylene) Bis(3-aminobenzamide), N,N'-(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(3-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)anthracene Aromatic diamines such as bis(4-aminocyclohexyl)methane and bis(4-amino-3-methylcyclohexyl)methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diaminohexane.

[0109] The above other diamines may be used alone or in combination of two or more depending on the liquid crystal orientation, pretilt angle, voltage holding characteristics, stored charge and other characteristics when used as a liquid crystal alignment film.

[0110] <Polymer>

[0111] The polymer of the present invention is a polymer obtained by using the above-mentioned diamine, but preferably, polyamic acid, polyamic acid ester, polyimide, polyurea, polyamide, etc. obtained by reacting a diamine component with tetracarboxylic dianhydride can be listed. From the viewpoint of being used as a liquid crystal aligning agent, it is preferably selected from at least one of polyimide precursors such as the above-mentioned polyamic acid, polyamic acid ester, and polyimide as an imide product of the polyimide precursor.

[0112] <Tetracarboxylic dianhydride>

[0113] As the tetracarboxylic acid component for obtaining the specific polymer, tetracarboxylic dianhydride represented by the following formula [II′] or a derivative thereof (tetracarboxylic acid, a dihalogenated tetracarboxylic acid compound, a tetracarboxylic acid dialkyl ester, or a dihalogenated tetracarboxylic acid dialkyl ester) (these are collectively referred to as specific tetracarboxylic acids) can be used.

[0114]

[0115] (In formula [II'], Q represents at least one structure selected from the group consisting of the following formulas [II'-a] to [II'-q].)

[0116]

[0117] In formula [II'-a], Q 1 ~Q 4 Each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring. 5 and Q 6 Each independently represents a hydrogen atom or a methyl group.

[0118] Among Q in formula [II'], tetracarboxylic dianhydrides and tetracarboxylic acid derivatives thereof having structures represented by formula [II'-a], formula [II'-c] to formula [II'-g], formula [II'-k] to formula [II'-m] or formula [II'-p] are preferred from the perspective of ease of synthesis and ease of polymerization reactivity when producing a polymer. Structures represented by formula [II'-a], formula [II'-e] to formula [II'-g], formula [II'-l], formula [II'-m] or formula [II'-p] are more preferred. Tetracarboxylic dianhydrides and tetracarboxylic acid derivatives thereof having structures represented by [II'-a], formula [II'-e], formula [II'-f], formula [II'-l], formula [II'-m] or formula [II'-p] are particularly preferred.

[0119] More specifically, it is preferable to use the following formula [II′-a-1] or formula [II′-a-2].

[0120]

[0121] The specific tetracarboxylic acid is preferably 50 to 100 mol% in 100 mol% of the total tetracarboxylic acid components. Among them, 70 to 100 mol% is more preferred, and 80 to 100 mol% is particularly preferred.

[0122] The specific tetracarboxylic acid may be used alone or in combination of two or more depending on the solubility in the solvent of the specific polymer, the coating property of the liquid crystal aligning agent, the alignment of the liquid crystal when formed into a liquid crystal aligning film, the voltage holding ratio, the stored charge and other characteristics.

[0123] As the tetracarboxylic acid component for obtaining the specific polymer, a tetracarboxylic acid (hereinafter, also referred to as other tetracarboxylic acids) or a derivative thereof other than the above-mentioned specific tetracarboxylic acid may be contained. As other tetracarboxylic acids, the tetracarboxylic acid compounds shown below or their derivatives (tetracarboxylic dianhydride, dihalogenated tetracarboxylic acid compounds, tetracarboxylic acid dialkyl ester compounds or dihalogenated tetracarboxylic acid dialkyl ester compounds) may be listed.

[0124] That is, other tetracarboxylic acids include 1,2,5,6-naphthalenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 2,3,3',4-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-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, 3,3',4,4'-diphenylsulfonetetracarboxylic acid, or 3,4,9,10-perylenetetracarboxylic acid.

[0125] Other tetracarboxylic acids may be used alone or in combination of two or more depending on the solubility in the solvent of the specific polymer, the coating properties of the liquid crystal aligning agent, the liquid crystal alignment properties when formed into a liquid crystal aligning film, the voltage holding ratio, the stored charge and other properties.

[0126] The polyimide precursor used for this invention can mention a polyamic acid and a polyamic acid ester. In addition, in a polyamic acid ester, all structural units may be an amic acid ester structure, and an amic acid structure may be contained in a part.

[0127] <Production method of polymer>

[0128] The polymer of the present invention is obtained by reacting the diamine component (comprising a plurality of the first diamine and the second diamine) described above with a tetracarboxylic acid component. As the method, for example, the following method can be cited: reacting a diamine component comprising one or more diamines with at least one tetracarboxylic acid component selected from the group consisting of tetracarboxylic dianhydride and its tetracarboxylic acid derivative to obtain polyamic acid. Specifically, the following method is used: polycondensing a primary diamine or a secondary diamine with tetracarboxylic dianhydride to obtain polyamic acid.

[0129] In order to obtain polyamic acid ester, a method of polycondensing a tetracarboxylic acid dialkyl ester obtained by esterifying a carboxylic acid group with a primary diamine or a secondary diamine, a method of polycondensing a dihalogenated tetracarboxylic acid compound obtained by halogenating a carboxylic acid group with a primary diamine or a secondary diamine, or a method of converting the carboxyl group of a polyamic acid into an ester can be used. In order to obtain a polyimide, a method of ring-closing the above-mentioned polyamic acid or polyamic acid ester to form a polyimide can be used.

[0130] The reaction of the diamine component and the tetracarboxylic acid component is usually carried out in a solvent. The solvent used at this time is not particularly limited as long as it is a solvent that dissolves the generated polyimide precursor. Examples of the solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the solvent shown in the following formula [D-1] to [D-3] can also be used.

[0131]

[0132] In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-2], D 2 represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-3], D 3 It represents an alkyl group having 1 to 4 carbon atoms.

[0133] These solvents can be used alone or in combination of two or more. Even if it is a solvent that does not dissolve the polyimide precursor, it can be mixed in the above-mentioned solvent and used as long as the generated polyimide precursor is not precipitated. In addition, the moisture in the solvent can hinder the polymerization reaction and become the cause of the hydrolysis of the generated polyimide precursor, so the solvent is preferably used a dehydrated solvent.

[0134] When the diamine component and the tetracarboxylic acid component are reacted in a solvent, the following methods can be cited: a method of adding the tetracarboxylic acid component directly or dispersing or dissolving the tetracarboxylic acid component in a solvent by stirring a solution in which the diamine component is dispersed or dissolved in the solvent; a method of adding the diamine component to a solution in which the tetracarboxylic acid component is dispersed or dissolved in the solvent; a method of alternately adding the diamine component and the tetracarboxylic acid component, etc., any of which methods can be used. In addition, when a plurality of diamine components or tetracarboxylic acid components are used and reacted, they can be reacted in a premixed state, or they can be reacted separately in sequence, and low molecular weight bodies reacted separately can be mixed and reacted to form a polymer.

[0135] The temperature for polycondensing the diamine component and the tetracarboxylic acid component can be selected from any temperature within the range of -20 to 150°C, but is preferably within the range of -5 to 100°C. The reaction can be carried out at any concentration, but the concentration of the diamine component and the tetracarboxylic acid component is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, relative to the above-mentioned solvent. The reaction may be carried out at a high concentration in the initial stage, and then the solvent may be added.

[0136] In the polymerization reaction of the polyimide precursor, the total molar ratio of the diamine components to the tetracarboxylic acid components (total molar ratio of the diamine components / total molar ratio of the tetracarboxylic acid components) is preferably 0.8 to 1.2. As in a normal polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the generated polyimide precursor.

[0137] The polyimide is a polyimide obtained by ring-closing the polyimide precursor. In the polyimide, the ring-closing rate (also referred to as the imidization rate) of the amic acid group does not necessarily need to be 100%, and can be arbitrarily adjusted according to the application and purpose. As a method for imidizing the polyimide precursor, thermal imidization by directly heating a solution of the polyimide precursor or catalytic imidization by adding a catalyst to the solution of the polyimide precursor can be listed.

[0138] In the liquid crystal alignment agent of the present invention, generally, the higher the imidization rate, the more reliable the liquid crystal alignment film will be. However, in the polymer of the present invention, since it has an imide ring derived from the first diamine, it is not necessarily necessary to increase the imidization rate. This is advantageous in terms of improving solubility and reprocessability.

[0139] The temperature for thermal imidization of the polyimide precursor in a solution is 100 to 400° C., preferably 120 to 250° C., and the method is preferably performed while removing water generated by the imidization reaction to the outside of the system. Catalytic imidization of the polyimide precursor can be performed by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at −20 to 250° C., preferably 0 to 180° C.

[0140] The amount of the basic catalyst is 0.5 to 30 mole times of the amic acid group, preferably 2 to 20 mole times, and the amount of the acid anhydride is 1 to 50 mole times of the amic acid group, preferably 3 to 30 mole times. As the basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be listed. Among them, pyridine has a moderate alkalinity that allows the reaction to proceed, so it is preferred. As anhydrides, acetic anhydride, trimellitic anhydride, and pyromellitic anhydride can be listed. In particular, if acetic anhydride is used, purification after the reaction is completed becomes easy, so it is preferred. The imidization rate based on catalyst imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

[0141] In the case of recovering the generated polyimide precursor or polyimide from the reaction solution of the polyimide precursor or polyimide, the reaction solution is put into a solvent to precipitate it. As solvents for precipitation, methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc. can be listed. The polymer put into the solvent and precipitated can be filtered and recovered, and then dried under normal pressure or reduced pressure, or at room temperature or heated. In addition, when the polymer recovered by precipitation is redissolved in a solvent and the operation of reprecipitation recovery is repeated 2 to 10 times, the impurities in the polymer can be reduced. As solvents at this time, for example, alcohols, ketones, hydrocarbons, etc. can be listed. If three or more solvents selected from them are used, the efficiency of purification is further improved, so it is preferred.

[0142] <Liquid crystal alignment agent>

[0143] The liquid crystal alignment agent of the present invention contains the above-mentioned polymer (hereinafter, also referred to as specific polymer), and may also contain two or more polymers of different structures. In addition, in addition to polymers, other polymers may also be contained. As the form of the polymer, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetals, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylates, etc. can be listed. In the case where the liquid crystal alignment agent of the present invention contains other polymers, the proportion of the specific polymer relative to the total polymer components is preferably 5% by mass or more, for example, 5 to 95% by mass can be listed.

[0144] From the perspective of forming a uniform film, the liquid crystal aligning agent is usually in the form of a coating liquid. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the above-mentioned polymer component and an organic solvent that dissolves the polymer component. At this time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the perspective of forming a uniform and defect-free coating film, it is preferably more than 1% by mass, and from the perspective of the storage stability of the solution, it is preferably less than 10% by mass. The concentration of the particularly preferred polymer is 2 to 8% by mass.

[0145] The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it can uniformly dissolve the polymer component. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2 N-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropaneamide, 3-butoxy-N,N-dimethylpropaneamide, γ-butyrolactam, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, etc. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is preferably used.

[0146] In addition, the organic solvent contained in the liquid crystal alignment agent of the present invention may be a solvent that improves the coating property and the surface smoothness of the coating film when the liquid crystal alignment agent is applied, in addition to the above-mentioned solvents. Specific examples of the organic solvent include, for example, the solvents described in paragraph

[0177] of the Japanese Patent Gazette No. WO2016-140328. As preferred specific examples, the following solvents can be listed. 4-Hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, etc.

[0147] The liquid crystal aligning agent of the present invention may also contain additional components other than the polymer component and the organic solvent. As such additional components, there can be listed: a bonding aid for improving the adhesion between the liquid crystal aligning film and the substrate, and the adhesion between the liquid crystal aligning film and the sealant; a crosslinking agent for improving the strength of the liquid crystal aligning film; a dielectric and a conductive material for adjusting the dielectric constant and resistance of the liquid crystal aligning film; an imidization accelerator for the purpose of making the imidization efficiency based on the heating of the polyimide precursor good when the coating is fired. As specific examples of these additional components, crosslinking compounds disclosed in paragraphs

[0104] on page 53 to paragraphs

[0116] on page 60 of International Publication No. 2015 / 060357 or known crosslinking agents can be listed. As preferred specific examples of crosslinking agents, compounds represented by the following formulas (CL-1) to (CL-11) can be listed. It is preferable that it is 0.1-30 mass parts with respect to 100 mass parts of the whole amount of the polymer contained in the liquid crystal aligning agent, and, as for the said crosslinking agent, it is more preferable that it is 1-20 mass parts.

[0148]

[0149] As adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate, functional silane-containing compounds and epoxy-containing compounds can be cited. Specific examples include compounds described in paragraph

[0180] of Japanese Patent Re-publication No. WO2016-140328.

[0150] <Liquid crystal alignment film>

[0151] The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. By using the liquid crystal alignment agent of the present invention, the following liquid crystal alignment film and liquid crystal display element can be provided: it is particularly suitable for the VA mode in which the liquid crystal molecules oriented vertically relative to the substrate respond according to the electric field, and is particularly suitable for the PSA mode, with excellent voltage retention, rapid relaxation of the accumulated charge, and excellent residual image characteristics. If an example of a method for obtaining a liquid crystal alignment film is listed, the cured film obtained by the following method can be directly used as a liquid crystal alignment film in such a state: after the liquid crystal alignment agent of the present invention is applied to the substrate, it is dried and fired as needed to obtain a cured film. In addition, the cured film is brushed, irradiated with polarized light or light of a specific wavelength, or treated with an ion beam, and UV can also be irradiated in a state where a voltage is applied to the liquid crystal display element after the liquid crystal is filled as an alignment film for PSA. In particular, it is useful as an alignment film for PSA.

[0152] As a substrate for coating a liquid crystal alignment agent, there is no particular limitation as long as it is a substrate with high transparency, and a plastic substrate such as an acrylic substrate, a polycarbonate substrate, etc. may also be used together with a glass substrate or a silicon nitride substrate. At this time, if a substrate having an ITO electrode or the like for driving a liquid crystal is used, it is preferred from the perspective of simplifying the process. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer may also be used, and the electrode in this case may also use a material that reflects light such as aluminum.

[0153] The coating method of the liquid crystal alignment agent is not particularly limited, and is generally screen printing, offset printing, flexographic printing, inkjet, etc. in industry. As other coating methods, there are dipping, roller coating, slit coating, spin coating, spray coating, etc., which can be used according to the purpose. After the liquid crystal alignment agent is applied to the substrate, the solvent is evaporated and fired using a heating unit such as a heating plate, a thermal cycle oven, and an IR (infrared) oven. The drying and firing processes after the liquid crystal alignment agent is applied can select any temperature and time. The drying process is not necessary, but when the time from coating to firing is not fixed with the substrate, or when it is not fired immediately after coating, it is preferred to perform a drying process. The drying can be performed as long as the solvent is removed to the extent that the shape of the coating is not deformed by the transportation of the substrate, and there is no particular limitation on the drying method. For example, a method of drying for 0.5 to 30 minutes, preferably for 1 to 5 minutes, on a heating plate at a temperature of 40 to 150°C, preferably at 60 to 100°C.

[0154] The firing temperature of the coating formed by applying the liquid crystal alignment agent is not limited, and is, for example, 100 to 350° C., preferably 120 to 300° C., and more preferably 150 to 250° C. The firing time is 5 to 240 minutes, preferably 10 to 90 minutes, and more preferably 20 to 90 minutes. Heating can be performed by a generally known method, for example, using a hot plate, a hot air circulation furnace, an infrared furnace, etc.

[0155] If the thickness of the liquid crystal alignment film after firing is too thin, the reliability of the liquid crystal display element may decrease, so it is preferably 5 to 300 nm, more preferably 10 to 200 nm. The liquid crystal alignment film of the present invention is useful as a liquid crystal alignment film for a VA-type, particularly PSA-mode liquid crystal display element.

[0156] <Liquid crystal display element and method for manufacturing the same>

[0157] As for the liquid crystal display element, after the liquid crystal alignment film is formed on the substrate by the above-mentioned method, a liquid crystal box can be made by a known method. As a specific example of a liquid crystal display element, a liquid crystal display element having a vertical alignment mode (VA mode) of a liquid crystal box is provided, and the liquid crystal box has two substrates arranged in an opposing manner, a liquid crystal layer arranged between the substrates, and the above-mentioned liquid crystal alignment film formed by a liquid crystal alignment agent arranged between the substrate and the liquid crystal layer. A more preferred specific example is a liquid crystal display element having a vertical alignment mode of a liquid crystal box made in the following manner (the above-mentioned PSA mode liquid crystal display element): a liquid crystal alignment film is formed by applying a liquid crystal alignment agent on two substrates and firing them, two substrates are arranged in a manner in which the liquid crystal alignment film is opposite to each other, and a liquid crystal layer composed of liquid crystals is clamped between the two substrates, that is, the liquid crystal layer is provided in contact with the liquid crystal alignment film, and ultraviolet rays are irradiated while a voltage is applied to the liquid crystal alignment film and the liquid crystal layer.

[0158] As a substrate of a liquid crystal display element, there is no particular limitation as long as it is a substrate with high transparency, and it is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, a substrate identical to the substrate described in the above-mentioned liquid crystal alignment film can be cited. An existing substrate with an electrode pattern and a protrusion pattern can be used, but in a liquid crystal display element, since a liquid crystal alignment agent containing a polyimide polymer of the present invention is used, a line / slit electrode pattern of 1 μm to 10 μm is formed on one side of the substrate, for example, and the structure in which a slit pattern and a protrusion pattern are not formed on the opposing substrate can also be operated. By using a liquid crystal display element of this structure, the process during manufacturing can be simplified and a high transmittance can be obtained.

[0159] In addition, in a high-function element such as a TFT type element, a substrate can be used in which an element such as a transistor can be formed between an electrode for driving liquid crystal and the substrate.

[0160] In the case of a transmissive liquid crystal display element, the above-mentioned substrate is usually used, but in a reflective liquid crystal display element, if only one side of the substrate is used, an opaque substrate such as a silicon wafer may be used. In this case, a material such as aluminum that reflects light may also be used in the electrode formed on the substrate.

[0161] The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element is not particularly limited, and the liquid crystal material used in the existing vertical alignment method can be used, for example, negative liquid crystals such as MLC-6608, MLC-6609, and MLC-3023 manufactured by Merck. In addition, in the liquid crystal display element of the PSA mode, for example, the polymerizable compound represented by the following formula can be used as a liquid crystal component.

[0162]

[0163] As a method for sandwiching the liquid crystal layer between two substrates, known methods can be cited. For example, the following method can be cited: prepare a pair of substrates with liquid crystal alignment films, scatter spacers such as beads on the liquid crystal alignment film of one substrate, adhere the other substrate in a manner that the surface on the side with the liquid crystal alignment film becomes the inner side, and decompress and inject the liquid crystal and seal it. In addition, a liquid crystal box can also be made by the following method: prepare a pair of substrates with liquid crystal alignment films, scatter spacers such as beads on the liquid crystal alignment film of one substrate, drip liquid crystal, and then adhere the other substrate in a manner that the surface on the side with the liquid crystal alignment film becomes the inner side and seal it. The thickness of the above-mentioned spacer is preferably 1 to 30 μm, and more preferably 2 to 10 μm.

[0164] The process of making a liquid crystal box by applying voltage to the liquid crystal alignment film and the liquid crystal layer while irradiating ultraviolet light can be listed as follows: by applying voltage between electrodes provided on the substrate to apply an electric field to the liquid crystal alignment film and the liquid crystal layer, and irradiating ultraviolet light while maintaining the electric field. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p, preferably 5 to 20 Vp-p. The irradiation amount of ultraviolet light is, for example, 1 to 60 J / cm 2 , preferably 40 J / cm 2 Hereinafter, the lower the ultraviolet irradiation amount, the more the reliability reduction caused by the destruction of the members constituting the liquid crystal display element can be suppressed, and the manufacturing efficiency can be improved by reducing the ultraviolet irradiation time, which is preferred.

[0165] As described above, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer while ultraviolet rays are irradiated, the polymerizable compound reacts to form a polymer, and the polymer stores the tilted direction of the liquid crystal molecules, thereby accelerating the response speed of the obtained liquid crystal display element. In addition, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer while ultraviolet rays are irradiated, the photoreactive side chains of at least one polymer selected from the polyimide precursor and the polyimide obtained by imidizing the polyimide precursor react with each other, or the photoreactive side chains of the polymer react with the polymerizable compound contained in the liquid crystal layer, thereby accelerating the response speed of the obtained liquid crystal display element, wherein the polyimide precursor includes: a side chain that orients the liquid crystal vertically, such as a second diamine compound having a side chain structure shown in the above formulas [S1] to [S3], and the above photoreactive side chain.

[0166] Next, a polarizing plate is placed. Specifically, it is preferable to bond a pair of polarizing plates to the surfaces of the two substrates on the opposite sides to the liquid crystal layer.

[0167] It should be noted that the liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above-mentioned configuration and manufacturing method as long as the liquid crystal alignment agent of the present invention is used, and can also be produced by other known methods. The process from the liquid crystal alignment agent to the liquid crystal display element is disclosed in, for example, paragraphs

[0074] on page 17 to

[0082] on page 19 of Japanese Patent Publication No. 2015-135393.

[0168] Example

[0169] <Example>

[0170] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0171] (Diamine compound)

[0172] p-PDA: p-phenylenediamine.

[0173] DA-1 to DA-9: These are first diamines (also referred to as specific diamines) represented by the following formulae DA-1 to DA-9, respectively. DA-1 to DA-6, DA-7, and DA-8 are novel compounds.

[0174] SC-1 to SC-4: side chain diamines represented by the following formulae SC-1 to SC-4.

[0175]

[0176] (Tetracarboxylic acid component)

[0177] CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0178] BODA: bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride.

[0179] TCA: 2,3,5-Tricarboxypentylacetic dianhydride.

[0180] (Solvent)

[0181] NMP: N-methyl-2-pyrrolidone.

[0182] BCS: Butyl Cellosolve.

[0183] THF: tetrahydrofuran.

[0184] DMF: N,N-dimethylformamide.

[0185] CH2Cl2: dichloromethane.

[0186] CHCl3: chloroform.

[0187] < 1 H-NMR measurement>

[0188] Apparatus: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (manufactured by BRUKER), 500 MHz.

[0189] Solvent: deuterated chloroform (CDCl3) or deuterated N,N-dimethyl sulfoxide ([D6]-DMSO).

[0190] Standard substance: tetramethylsilane (TMS).

[0191] <Synthesis of diamine>

[0192] (Synthesis example 1)

[0193] Synthesis of [DA-1]:

[0194]

[0195] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (39.4 g, 189 mmol) and NMP (394 g) were placed in a 1L four-necked flask. Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride (23.4 g, 94 mmol) was added in a water bath, and the mixture was stirred at 60°C for 6 hours. Next, pyridine (89.2 g, 1128 mmol) and acetic anhydride (60.5 g, 593 mmol) were added to the reaction solution, and the mixture was stirred at 110°C. After the reaction was completed, the reaction system was poured into pure water (2500 g), and the precipitate was filtered out. Next, the obtained crude product was isolated by silica gel column chromatography (eluent: ethyl acetate), thereby obtaining 40.6 g of [DA-1-1].

[0196] [DA-1-1] (33.8 g, 54 mmol) and CH2Cl2 (510 g) were placed in a 1L four-necked flask. After trifluoroacetic acid (55.0 g, 539 mmol) was added dropwise in a water bath, the mixture was stirred at room temperature. After the reaction was completed, the precipitate was filtered out and washed with CH2Cl2 (300 g). Pure water (700 g) was added to the obtained crude product, the mixture was neutralized with triethylamine (50 g), and the precipitate was filtered out. DMF (50 g) and methanol (500 g) were added to the obtained crude product, and the mixture was repulped and washed at room temperature to obtain 11.9 g of [DA-1] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-1].

[0197] 1H NMR (500MHz, [D6]-DMSO): δ7.30-7.33(m, 4H), 6.52-6.58(m, 4H), 5.26(s, 2H), 5.20(s, 2H), 3.33(s, 2H), 3.26-3.28(m, 2H), 2.95-2.98(m, 2H), 2.44-2.48(m, 2H), 1.90-1.94(m, 1H), 1.67-1.73(m, 1H).

[0198] (Synthesis example 2)

[0199] Synthesis of [DA-2]:

[0200]

[0201] In a 2L four-necked flask, tert-butyl (3-aminophenyl) carbamate (83.4 g, 400 mmol) and NMP (840 g) were added, and bicyclo [3, 3, 0] octane-2, 4, 6, 8-tetracarboxylic dianhydride (46.6 g, 186 mmol) was added in a water bath, and then stirred at 60°C for 6 hours. Next, pyridine (178.1 g, 2250 mmol) and acetic anhydride (115.5 g, 1120 mmol) were added to the reaction solution, and stirred at 110°C. After the reaction was completed, the reaction system was poured into pure water (5000 g), and the precipitate was filtered out. Next, the obtained crude product was isolated by silica gel column chromatography (eluent: ethyl acetate), thereby obtaining 103.5 g of [DA-2-1].

[0202] [DA-2-1] (100.5 g, 160 mmol) and CH2Cl2 (1500 g) obtained above were placed in a 2L four-necked flask, and trifluoroacetic acid (165.7 g, 1620 mmol) was added dropwise in a water bath, followed by stirring at room temperature. After the reaction was completed, the precipitate was filtered out and washed with CH2Cl2 (600 g). Pure water (2000 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine (100 g), and the precipitate was filtered out. DMF (100 g) and methanol (1000 g) were added to the obtained crude product, and the mixture was re-slurried and washed at room temperature to obtain 32.3 g of [DA-2] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-2].

[0203] 1HNMR (500MHz, [D6]-DMSO): δ7.01-7.08(m, 2H), 6.54-6.58(m, 2H), 6.24-6.31(m, 4H), 5.24(s, 2H), 5.18(s, 2H ), 3.37 (s, 2H), 3.28-3.30 (m, 2H), 2.96-2.97 (d, 2H), 2.47-2.53 (m, 2H), 1.95-1.99 (m, 1H), 1.75-1.80 (m, 1H).

[0204] (Synthesis example 3)

[0205] Synthesis of [DA-3]:

[0206]

[0207] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (20.0 g, 96 mmol) and NMP (200 g) were placed in a 1L four-necked flask, and 1,2,3,4-butanetetracarboxylic dianhydride (8.6 g, 43 mmol) was added in a water bath, followed by stirring at 40°C for 6 hours. Next, pyridine (20.5 g, 259 mmol) and acetic anhydride (13.2 g, 130 mmol) were added to the reaction solution, and stirred at 60°C. After the reaction was completed, the reaction system was poured into pure water (1000 g), and the precipitate was filtered out. Next, THF (180 g) and methanol (200 g) were added to the obtained crude product, and reslurry washing was performed at room temperature, thereby obtaining [DA-3-1].

[0208] [DA-3-1] (14.7 g, 25 mmol) and CH2Cl2 (400 g) obtained above were placed in a 1L four-necked flask, trifluoroacetic acid (43.3 g, 380 mmol) was added dropwise in a water bath, and then stirred at room temperature. After the reaction was completed, hexane (1000 g) was added to the reaction solution, and the precipitate was filtered out. Pure water (400 g) was added to the obtained crude product, neutralized with pyridine (40 g), and the precipitate was filtered out. DMF (10 g) was added to the obtained crude product, and after re-slurry washing, ethyl acetate (50 g) was further added to the crude product, and re-slurry washing was performed at 60°C, thereby obtaining 6.6 g of [DA-3] (white solid). The results of 1H-NMR of the target product are shown below. Based on this result, it was confirmed that the obtained solid was the target [DA-3].

[0209] 1H NMR (400MHz, [D6]-DMSO): δ6.84-7.95 (d, 4H), 6.56-6.60 (d, 4H), 5.31 (s, 4H) , 3.52-3.55(t, 2H), 2.94-3.01(q, 2H), 2.65-2.67(d, 1H), 2.61-2.62(d, 1H).

[0210] (Synthesis Example 4)

[0211] Synthesis of [DA-4]:

[0212]

[0213] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (33.3 g, 160 mmol) and NMP (330 g) were placed in a 1L four-necked flask, and bicyclo[2.2.2]octane-2,3:5,6-tetracarboxylic dianhydride (20.0 g, 80 mmol) was added in a water bath, followed by stirring at 60°C for 6 hours. Next, pyridine (38.0 g, 480 mmol) and acetic anhydride (24.5 g, 240 mmol) were added to the reaction solution, and stirred at 110°C. After the reaction was completed, the reaction system was poured into pure water (1500 g), and the precipitate was filtered out. Next, the obtained crude product was isolated by silica gel column chromatography (eluent: ethyl acetate / hexane = 2 / 1 (volume ratio)), and ethyl acetate (200 g) was further added to the crude product, followed by reslurry washing at 50° C. to obtain 29.8 g of [DA-4-1].

[0214] Into a 1L four-necked flask, put [DA-4-1] (29.8 g, 47 mmol) obtained above and CHCl3 (440 g), add trifluoroacetic acid (53.9 g, 473 mmol) dropwise in a water bath, and stir at 50°C. After the reaction is completed, filter out the precipitate and wash it with CHCl3 (300 g). Add pure water (300 g) to the obtained crude product, neutralize it with triethylamine (20 g), and filter out the precipitate. Add DMF (180 g) and methanol (180 g) to the obtained crude product, re-slurry and wash it at room temperature, thereby obtaining 16.9 g of [DA-4] (white solid). The results of 1H-NMR of the target product are shown below. Based on this result, it was confirmed that the obtained solid was the target [DA-4].

[0215] 1H NMR (500MHz, [D6]-DMSO): δ6.86-6.88 (d, 4H), 6.60-6.62 (d, 4H), 5.35 (s, 4H), 3.23 (s, 4H), 2.50 (s, 2H), 1.40 (s, 4H).

[0216] (Synthesis Example 5)

[0217] Synthesis of [DA-5]:

[0218]

[0219] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (25.0 g, 120 mmol), pyridine (28.5 g, 360 mmol) and NMP (250 g) were placed in a 1L four-necked flask, and bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (14.9 g, 60 mmol) was added in a water bath, and then stirred at 80°C. After the reaction was completed, the reaction system was poured into pure water (1500 g) and the precipitate was filtered out. Then, methanol (1500 g) was added to the obtained crude product, and re-slurry washing was performed at room temperature, thereby obtaining 30.6 g of [DA-5-1].

[0220] [DA-5-1] (30.6 g, 49 mmol) and CHCl3 (300 g) were placed in a 1L four-necked flask. After trifluoroacetic acid (55.5 g, 487 mmol) was added dropwise in a water bath, the mixture was stirred at 50°C. After the reaction was completed, the precipitate was filtered out and washed with CHCl3 (100 g). Methanol (250 g) was added to the obtained crude product, the mixture was neutralized with triethylamine (20 g), and the precipitate was filtered out. Methanol (100 g) was added to the obtained crude product, and the mixture was re-slurried and washed at room temperature to obtain 20.0 g of [DA-5] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-5].

[0221] 1H NMR (500MHz, [D6]-DMSO): δ6.70-6.74 (d, 4H), 6.55-6.58 (d, 4H), 6.23-6.24 (q, 2H), 5.34 (d, 4H), 3.45-3.47 (s, 2H), 3.30 (s, 4H).

[0222] (Synthesis Example 6)

[0223] Synthesis of [DA-6]:

[0224]

[0225] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (25.0 g, 120 mmol) and NMP (250 g) were placed in a 1L four-necked flask, and 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic anhydride (13.5 g, 60 mmol) was added in a water bath, followed by stirring at 50°C for 6 hours. Next, pyridine (28.5 g, 360 mmol) and acetic anhydride (18.5 g, 180 mmol) were added to the reaction solution, followed by stirring at 50°C. After the reaction was completed, the reaction system was poured into pure water (1500 g), and the precipitate was filtered out. Next, methanol (150 g) was added to the obtained crude product, and reslurry washing was performed at room temperature, thereby obtaining 15.4 g of [DA-6-1].

[0226] [DA-6-1] (15.4 g, 26 mmol) and CHCl3 (154 g) obtained above were placed in a 1L four-necked flask, trifluoroacetic acid (29.1 g, 255 mmol) was added dropwise in a water bath, and the mixture was stirred at 50°C. After the reaction was completed, the precipitate was filtered out and washed with CHCl3 (50 g). Pure water (200 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine (10 g), and the precipitate was filtered out to obtain 9.9 g of [DA-6] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-6].

[0227] 1H NMR (500MHz, [D6]-DMSO): δ6.86-6.88 (d, 4H), 6.59-6.62 (d, 4H), 5.33 (s, 4H), 3.04-3.06 (t, 4H), 2.11 (s, 4H).

[0228] (Synthesis Example 7)

[0229] Synthesis of [DA-7]:

[0230]

[0231] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (33.3 g, 160 mmol) and NMP (300 g) were placed in a 1L four-necked flask, and tetrahydro-3,3'-dimethyl[3,3'-bifuran]-2,2',5,5'-tetraone (17.2 g, 76 mmol) was added in a water bath, and stirred at 40°C for 6 hours. Next, pyridine (36.4 g, 460 mmol) and acetic anhydride (23.5 g, 230 mmol) were added to the reaction solution, and stirred at 60°C. After the reaction was completed, the reaction system was poured into pure water (1500 g) and the precipitate was filtered out. Next, the obtained crude product was isolated by silica gel column chromatography (eluent: ethyl acetate / hexane = 1 / 1 (volume ratio)), methanol (50 g) was added to the obtained crude product, and reslurry washing was performed at room temperature to obtain 4.6 g of [DA-7-1].

[0232] [DA-7-1] (4.6 g, 8 mmol) and CHCl3 (50 g) obtained above were placed in a 1L four-necked flask, and trifluoroacetic acid (17.2 g, 152 mmol) was added dropwise in a water bath, followed by stirring at 50°C. After the reaction was completed, hexane (150 g) was added to the reaction solution, and the precipitate was filtered out. Pure water (30 g) was added to the obtained crude product, and triethylamine (2 g) was added and neutralized, and then injected into ethyl acetate (200 g). The organic layer was washed with pure water (300 g) and concentrated. Hexane (30 g) was added to the obtained crude product, and the slurry was re-mixed and washed at room temperature, thereby obtaining 2.7 g of [DA-7] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-7].

[0233] 1H NMR (500MHz, [D6]-DMSO): δ6.84-6.86 (d, 4H), 6.58-6.59 (d, 4H), 5.31 (s, 4H), 2.98-3.00 (d, 2H), 2.67-2.71 (d, 2H), 1.45 (s, 6H).

[0234] (Synthesis Example 8)

[0235] Synthesis of [DA-8]:

[0236]

[0237] 4,4'-(ethane-1,2-diylbis(oxy))diphenylamine (109.5 g, 448 mmol) and DMF (850 g) were placed in a 2L four-necked flask, and di-tert-butyl dicarbonate (32.8 g, 151 mmol) was added dropwise in a water bath, followed by stirring at room temperature. After the reaction was completed, the reaction solution was concentrated, and the resulting residue was isolated by silica gel column chromatography (eluent: ethyl acetate / hexane = 1 / 1 (volume ratio)), thereby obtaining 45.3 g of [DA-8-1].

[0238] [DA-8-1] (44.7 g, 130 mmol) and NMP (450 g) were placed in a 1L four-necked flask, and bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride (23.4 g, 94 mmol) was added in a water bath, followed by stirring at 60°C for 6 hours. Next, pyridine (58.1 g, 735 mmol) and acetic anhydride (38.2 g, 374 mmol) were added to the reaction solution, and stirred at 110°C. After the reaction was completed, the reaction system was poured into pure water (4000 g), and the precipitate was filtered out. Next, DMF (250 g) was added to the obtained crude product, and reslurry washing was performed at 70°C, thereby obtaining 36.8 g of [DA-8-2].

[0239] [DA-8-2] (36.8 g, 41 mmol) and CHCl3 (750 g) were placed in a 1L four-necked flask. After trifluoroacetic acid (46.8 g, 410 mmol) was added dropwise in a water bath, the mixture was stirred at 50°C. After the reaction was completed, the reaction solution was injected into hexane (750 g) and the precipitate was filtered out. Methanol (1200 g) was added to the obtained crude product, and triethylamine (50 g) was added and neutralized, and the precipitate was filtered out. Next, methanol (1200 g) was added to the obtained crude product, and the slurry was re-mixed and washed at room temperature, thereby obtaining 26.3 g of [DA-8] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-8].

[0240] 1H NMR (500MHz, [D6]-DMSO): δ7.00-7.11 (m, 8H), 6.69-6.71 (d, 4H), 6.51-6.53 (d, 4H), 4.64 (s, 4H), 4.27-4.28 (d, 4H), 4. 16-4.17(d, 4H), 3.40(s, 2H), 3.34(s, 2H), 3.00-3.01(d, 2H), 2.56-2.59(d, 2H), 1.94-1.97(d, 1H), 1.72-1.75(d, 1H).

[0241] (Synthesis Example 9)

[0242] Synthesis of [DA-9]:

[0243]

[0244] N-(tert-butyloxycarbonyl)-1,4-phenylenediamine (20.0 g, 96 mmol) and NMP (200 g) were placed in a 1L four-necked flask, and 3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic acid 1,4:2,3-dianhydride was added in a water bath, followed by stirring at 60°C for 6 hours. Next, pyridine (22.8 g, 288 mmol) and acetic anhydride (14.7 g, 144 mmol) were added to the reaction solution, followed by stirring at 110°C. After the reaction was completed, the reaction system was poured into pure water (1000 g), and the precipitate was filtered out. Next, the obtained crude product was isolated by silica gel column chromatography (eluent: ethyl acetate / hexane = 2 / 1 (volume ratio)), and methanol (300 g) was further added to the crude product, and reslurry washing was performed at room temperature to obtain 15.6 g of [DA-9-1].

[0245] [DA-9-1] (15.6 g, 26 mmol) and CH2Cl2 (230 g) were placed in a 1L four-necked flask. After trifluoroacetic acid (29.3 g, 257 mmol) was added dropwise in a water bath, and the mixture was stirred at room temperature. After the reaction was completed, the precipitate was filtered out and washed with CH2Cl2 (200 g). Pure water (100 g) was added to the obtained crude product, and the mixture was neutralized with pyridine (5 g), and the precipitate was filtered out. DMF (30 g) and methanol (300 g) were added to the obtained crude product, and the mixture was re-slurried and washed at room temperature to obtain 8.3 g of [DA-9] (white solid). The results of 1H-NMR of the target product are shown below. Based on the results, it was confirmed that the obtained solid was the target [DA-9].

[0246] 1H NMR (500MHz, [D6]-DMSO): δ6.74-6.77 (m, 4H), 6.53-6.56 (d, 4H), 5.21-5.22 (d, 4H), 3.72-3.75 (d, 1H) , 3.51 (s, 1H), 3.03 (s, 2H), 2.91-2.99 (m, 1H), 2.75-2.81 (m, 1H), 2.38-2.41 (d, 1H), 2.14-2.17 (m, 1H).

[0247] <Preparation of Liquid Crystal Alignment Agent>

[0248] (Reference Example 1)

[0249] DA-1 (4.30 g, 10.0 mmol) was dissolved in NMP (17.2 g), and the mixture was stirred at 40° C. for 30 minutes. Then, CBDA (1.82 g, 9.3 mmol) and NMP (7.3 g) were added and reacted at 40° C. for 12 hours to obtain a polyamic acid solution (A).

[0250] NMP (25.0 g) and BCS (10.0 g) were added to this polyamic acid solution (A) (15.0 g), and the liquid crystal aligning agent (A1) was obtained by stirring at room temperature for 5 hours.

[0251] (Reference Example 2 to Reference Example 9)

[0252] Except having changed the 1st diamine as shown in Table 1, it carried out with the method similar to Reference Example 1, and prepared the liquid crystal aligning agents B1-I1.

[0253] (Comparative Reference Example 1)

[0254] Liquid crystal aligning agent J1 was prepared by the same method as in Reference Examples 1 to 9, except that specific diamine was changed to p-PDA.

[0255] [Table 1]

[0256]

[0257] <Production of Liquid Crystal Cell>

[0258] (Reference Example 10)

[0259] The liquid crystal aligning agent (A1) obtained in Reference Example 1 was spin-coated on the ITO surface of a 3 cm×4 cm ITO-attached glass substrate, sintered at 80°C for 1 minute and 30 seconds using a hot plate, and then sintered in an infrared heating furnace at 230°C for 20 minutes to produce a polyimide-coated substrate with a film thickness of 100 nm.

[0260] Two polyimide-coated substrates were prepared by the above method. After 4 μm bead spacers were spread on the liquid crystal alignment film surface of one substrate, a thermosetting sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was printed thereon. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was set to the inner side, and after it was bonded to the previous substrate, the sealant was cured to produce an empty box. Liquid crystal MLC-3023 (trade name manufactured by MERCK Co., Ltd.) containing a polymerizable compound for PSA was injected into the empty box by the reduced pressure injection method to produce a liquid crystal box. The voltage holding ratio of the liquid crystal box was measured.

[0261] Next, a DC voltage of 15 V was applied to the liquid crystal cell, and 10 J / cm 2UV that has passed through a 325 nm cutoff filter (also referred to as primary PSA treatment). The UV illuminance was measured using UV-MO3A manufactured by ORC Corporation.

[0262] Then, in order to deactivate the unreacted polymerizable compound remaining in the liquid crystal cell, UV (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a UV-FL irradiation device manufactured by Toshiba Lighttech Co., Ltd. (referred to as secondary PSA treatment) without applying voltage. Then, the voltage holding ratio was measured.

[0263] <Evaluation of voltage holding ratio>

[0264] Using the liquid crystal cell prepared above, a voltage of 1V was applied for 60μs in a hot air circulation oven at 60°C, and the voltage was measured after 1667msec. The voltage was maintained as the voltage holding ratio. The voltage holding ratio was measured using VHR-1 manufactured by Toyo Technology Co., Ltd.

[0265] (Reference Examples 11 to 15)

[0266] VHR was measured in the same manner as in Reference Example 10, except that liquid crystal aligning agents (B1), (C1), (E1), (F1), and (I1) were used instead of the liquid crystal aligning agent (A1).

[0267] (Comparative Reference Example 2)

[0268] Except having used the liquid crystal aligning agent (J1) instead of the liquid crystal aligning agent (A1), the same operation as in Reference Example 10 was carried out, and VHR was measured.

[0269] The measurement results of VHR are shown below.

[0270] [Table 2]

[0271]

[0272] As shown in Table 2, in Comparative Reference Example 2, VHR was 20% or less from the beginning, which was very low. In contrast, in Reference Examples 10 to 15, VHR was 60% or more even after the secondary PSA treatment. This result shows that the liquid crystal alignment agent into which the specific diamine is introduced can ensure high driving reliability compared to the liquid crystal alignment agent into which the specific diamine is not introduced.

[0273] (Example 1)

[0274] DA-1 (2.15 g, 5.0 mmol) and SC-1 (1.90 g, 5.0 mmol) were dissolved in NMP (16.2 g), and stirred at 40° C. for 30 minutes. Then, CBDA (1.82 g, 9.3 mmol) and NMP (7.3 g) were added and reacted at 40° C. for 12 hours to obtain a polyamic acid solution (K).

[0275] NMP (20.0 g) and BCS (15.0 g) were added to this polyamic acid solution (K) (15.0 g), and the mixture was stirred at room temperature for 5 hours, thereby obtaining a liquid crystal aligning agent (K1).

[0276] (Examples 2 to 9)

[0277] Except having changed the specific diamine (1st diamine) and the side chain diamine (2nd diamine) as shown in Table 3, it carried out with the method similar to Example 1, and prepared the liquid crystal aligning agents L1-S1.

[0278] (Example 10)

[0279] DA-1 (3.23 g, 7.5 mmol) and SC-4 (1.90 g, 2.5 mmol) were dissolved in NMP (20.5 g), stirred at 40° C. for 30 minutes, and then TCA (2.20 g, 9.8 mmol) and NMP (8.8 g) were added and reacted at 60° C. for 10 hours to obtain a polyamic acid solution (T).

[0280] NMP (20.0 g) and BCS (15.0 g) were added to this polyamic acid solution (T) (15.0 g), and the mixture was stirred at room temperature for 5 hours, thereby obtaining a liquid crystal aligning agent (T1).

[0281] (Example 11)

[0282] DA-5 (2.83 g, 7.0 mmol) and SC-2 (1.30 g, 3.0 mmol) were dissolved in NMP (16.5 g), stirred at 40° C. for 30 minutes, and then BODA (1.88 g, 7.5 mmol) and NMP (7.5 g) were added and reacted at 60° C. for 5 hours. Then, CBDA (0.45 g, 2.3 mmol) and NMP (1.8 g) were added and reacted at 40° C. for 12 hours to obtain a polyamic acid solution (U).

[0283] NMP (20.0 g) and BCS (15.0 g) were added to this polyamic acid solution (U) (15.0 g), and the mixture was stirred at room temperature for 5 hours, thereby obtaining a liquid crystal aligning agent (U1).

[0284] (Examples 12 and 13)

[0285] Except having changed the specific diamine, the side chain diamine, and the tetracarboxylic acid component as shown in Table 3, it carried out by the method similar to Example 11, and prepared liquid crystal aligning agents V1 and W1.

[0286] [Table 3]

[0287]

[0288] <Preparation of samples for evaluation of sealing tightness>

[0289] The liquid crystal orientation agent (K1) obtained in Example 1 was filtered through a filter with a pore size of 1.0 μm, and then spin-coated on a glass substrate with a transparent electrode. After drying on a hot plate at 80°C for 2 minutes, it was calcined at 230°C for 20 minutes to obtain a coating with a film thickness of 100 nm. Two substrates obtained in this way were prepared, and after spreading bead spacers with a diameter of 4 μm on the liquid crystal orientation film surface of one substrate, a sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was dripped. Next, the liquid crystal orientation film surface of the other substrate was set to the inner side and the overlapping width of the substrates was 1 cm. At this time, the amount of sealant added was adjusted so that the diameter of the sealant after bonding was about 3 mm. After fixing the two bonded substrates with a clamp, they were thermally cured at 120°C for 1 hour to prepare a sample for adhesion evaluation.

[0290] <Measurement of sealing tightness>

[0291] The prepared samples were fixed to the ends of the upper and lower substrates using a table-top precision universal testing machine AGS-X500N manufactured by Shimadzu Corporation, and then pressed from the top of the center of the substrate to measure the pressure (N) during peeling. Then, the adhesive strength was evaluated using the value obtained by normalizing the pressure (N) according to the measured diameter of the sealant.

[0292] <Preparation of samples for evaluation of reprocessing characteristics>

[0293] (Test Example 1)

[0294] The liquid crystal alignment agent (K1) obtained in Example 1 was filtered through a filter with a pore size of 1.0 μm, and then spin-coated on a 3 cm×4 cm glass substrate with an ITO electrode. After drying on a heating plate at 80°C for 2 minutes, it was calcined at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film with a film thickness of 100 nm.

[0295] <Evaluation of reprocessing characteristics>

[0296] In a 50mL beaker containing 15g of NMP, the substrate with the liquid crystal alignment film was immersed for 30 seconds. At this time, it was confirmed that a portion of the coated liquid crystal alignment film was immersed in NMP. After 30 seconds, pure water was used to wash off the NMP attached to the substrate, and it was confirmed by visual inspection whether the liquid crystal alignment film of the portion immersed in NMP remained. The situation where the liquid crystal alignment film of the portion immersed in NMP completely disappeared was defined as good reprocessability, and the situation where the liquid crystal alignment film remained or partially remained was defined as poor reprocessability.

[0297] (Test Examples 2 to 13)

[0298] Except having changed the liquid crystal aligning agent (K1) into the liquid crystal aligning agent of Examples 2-13, the same operation as in Test Example 1 was carried out, and the seal adhesiveness and the reprocessing characteristics were evaluated.

[0299] (Comparative Test Examples 1 to 10)

[0300] Except having changed the liquid crystal aligning agent (K1) into the liquid crystal aligning agent of Reference Examples 1-9 and Comparative Reference Example 1, it carried out similarly to Example 1, and evaluated the sealing adhesiveness and the reworking characteristic.

[0301] (Results of Test Example)

[0302] The results of the sealing tightness and rework characteristics are shown below.

[0303] [Table 4]

[0304]

[0305] Compared with Comparative Test Examples 1 to 10 tested with the liquid crystal aligning agent using only the specific diamine, in Test Examples 1 to 13 tested using the liquid crystal aligning agents of Examples 1 to 13 introduced with the specific diamine, the reprocessing characteristics were excellent.

Claims

1. A diamine, characterized in that The diamine is represented by the following formula [II], In formula [II], Z 2 is selected from the following formulas [Z-1] to [Z-4], [Z-6] and [Z-7]; * represents a bonding bond, 2. The diamine according to claim 1, characterized in that The diamine is represented by the following formula,

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