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

Abstract

A liquid crystal alignment agent is provided for forming a liquid crystal alignment film exhibiting high voltage retention rate, suppressed image retention, and low liquid crystal pretilt angle characteristics; a liquid crystal alignment film obtained from the liquid crystal alignment agent; and a liquid crystal display element having the liquid crystal alignment film. A liquid crystal alignment agent is characterized by containing a polymer having at least one repeating unit selected from the group consisting of repeating units (p1) shown in formula (1) and imidized structural units of the repeating unit (p1). (In formula (1), X1 represents a tetravalent organic group. Y1 is a divalent organic group represented by "-Ar1-O-W-O-Ar2-". Ar1 and Ar2 each independently represent any divalent aromatic group in a divalent benzene ring or biphenyl structure, wherein any hydrogen atom of the aromatic group is optionally substituted by a monovalent group. W is *-(CH2).) m -L-A-*(L represents -O-C(=O)- or -C(=O)-O-, A represents -(CH2)- n - m is an integer from 1 to 6. n is an integer from 1 to 16. When n is 2 or more, any -CH2- constituting A may be replaced by -O-, -C(=O)-, -NH-, -O-C(=O)-, -C(=O)-O-, -C=C-, phenylene, or cyclohexylene. Additionally, a portion of the hydrogen atoms in W may be replaced by a halogen atom, methyl, trifluoromethyl, or hydroxyl group. ) represents a divalent organic group with 4 to 20 carbon atoms. * indicates a linking bond. R and Z each independently represent a hydrogen atom or a monovalent organic group.

Description

Technical Field

[0001] The present invention relates to liquid crystal alignment agents, liquid crystal alignment films obtained from the liquid crystal alignment agents, liquid crystal display elements having the liquid crystal alignment films, and novel diamines and polymers suitable for them. Background Technology

[0002] Liquid crystal display elements (LCDs) are widely used in applications ranging from small devices like mobile phones and smartphones to larger applications such as televisions and surveillance systems. Furthermore, various driving methods have been developed, including different electrode structures and the physical properties of the liquid crystal molecules used. Examples of known LCDs include those using TN (Twisted Nematic), STN (SuperTwisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (Fringe Field Switching). These LCDs typically incorporate a liquid crystal alignment film, essential for controlling the alignment of the liquid crystal molecules. Polyamic acid and polyimide are commonly used as materials for the liquid crystal alignment film due to their excellent properties, such as heat resistance, mechanical strength, and affinity for liquid crystals.

[0003] High display quality is required for liquid crystal display elements; for example, a high voltage retention rate is one of the desirable characteristics. For this purpose, Patent Document 1 discloses a composition for a liquid crystal alignment film containing an aromatic diamine such as 1,5-bis(4-aminophenoxy)pentane. Patent Document 2 discloses a polymer component using polyamic acid, obtained by reacting a diamine with two aromatic rings linked by a specific alkylene group with a tetracarboxylic acid derivative as a liquid crystal alignment agent.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 06-194670

[0007] Patent Document 2: Japanese Patent Application Publication No. 2014-132326 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In recent years, with the increasing performance of liquid crystal display elements (LCDs), in addition to their applications in large-screen and high-resolution LCD televisions, research is also underway into their applications in automotive, such as in-vehicle navigation systems, dashboards, surveillance cameras, and monitoring systems for medical cameras. Therefore, the demands on LCDs, especially for high-resolution and high-performance components, are further increasing. As for the liquid crystal alignment film, it is required to enhance the various characteristics of the LCD.

[0010] One object of the present invention is to form a liquid crystal alignment film having a high voltage retention rate, which provides conditions for achieving long-term reliability of display quality by suppressing image retention (image retention of zones and lines), unevenness, or contamination caused over time by external stimuli such as light and temperature. Another object of the present invention is to provide: a liquid crystal alignment agent capable of forming a liquid crystal alignment film that suppresses image retention caused by long-term AC drive (hereinafter also referred to as AC image retention), meets the requirements of viewing angle characteristics, and displays a liquid crystal pretilt angle characteristic; a liquid crystal display element having the liquid crystal alignment film; and novel diamines and polymers suitable for them.

[0011] Solution for solving the problem

[0012] In order to achieve the above-mentioned objectives, the inventors conducted in-depth research and found that liquid crystal alignment agents containing specific polymers are effective in achieving the above objectives, thereby completing the present invention.

[0013] The present invention is based on the following principles.

[0014] A liquid crystal alignment agent, characterized in that it contains a polymer having at least one repeating unit selected from the group consisting of a repeating unit (p1) shown in formula (1) and an imidized structural unit of the repeating unit (p1).

[0015]

[0016] In formula (1), X1 represents a tetravalent organic group. Y1 is a divalent organic group represented by "-Ar1-OWO-Ar2-".

[0017] Ar1 and Ar2 each independently represent any divalent aromatic group in a divalent benzene ring or biphenyl structure, wherein any hydrogen atom of the aromatic group is optionally replaced by a monovalent group.

[0018] W stands for *-(CH2) m -LA-*(L represents -OC(=O)- or -C(=O)-O-, A represents -(CH2) n -

[0019] m is an integer from 1 to 6. n is an integer from 1 to 16. When n is 2 or more, any -CH2- constituting A may be replaced by -O-, -C(=O)-, -NH-, -OC(=O)-, -C(=O)-O-, -C=C-, phenylene, or cyclohexylene.

[0020] Additionally, some of the hydrogen atoms in W may be optionally replaced by halogen atoms, methyl groups, trifluoromethyl groups, or hydroxyl groups. (The symbol ) represents a divalent organic group with 4 to 20 carbon atoms. * indicates a linking bond.

[0021] R and Z each independently represent a hydrogen atom or a monovalent organic group.

[0022] It should be noted that, in this invention, halogen atoms can include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and * indicates a connecting bond.

[0023] The effects of the invention

[0024] According to the present invention, a liquid crystal alignment agent that forms a liquid crystal alignment film exhibiting high voltage retention rate, suppressing image retention, and exhibiting low liquid crystal pretilt angle characteristics can be obtained; a liquid crystal alignment film obtained from the liquid crystal alignment agent; a high-performance liquid crystal display element having the liquid crystal alignment film; and novel diamines and polymers used in the manufacture thereof.

[0025] The mechanism by which the above-mentioned effects of the present invention are obtained is not clear, but it is presumed to be roughly as follows. First, it is believed that the specific diamine described later has a structure in which oxygen atoms are bonded to aromatic groups. Therefore, when a liquid crystal alignment film is made, the voltage holding rate is improved by interacting with ionic impurities that are the cause of defects and suppressing the impurity diffusion trapping phenomenon. It is also believed that the above-mentioned effects are obtained because the same trapping phenomenon of impurities is also caused by the ester bonds present in the specific diamine. Furthermore, it is believed that by giving the specific diamine ester bonds and alkylene chains, the stretchability of the polymer during alignment treatment is increased, resulting in high liquid crystal alignment, and thus a liquid crystal alignment film in which the generation of AC image retention is suppressed is obtained. Attached Figure Description

[0026] Figure 1 A schematic partial cross-sectional view is shown to illustrate an example of the transverse electric field liquid crystal display element of the present invention.

[0027] Figure 2 A schematic partial cross-sectional view is provided to illustrate other examples of the lateral electric field liquid crystal display element of the present invention. Detailed Implementation

[0028] <Polymers contained in liquid crystal alignment agents>

[0029] The liquid crystal alignment agent of the present invention is characterized by comprising a polymer having at least one repeating unit selected from the group consisting of a repeating unit (p1) shown in the following formula (1) and an imidized structural unit of the repeating unit (p1).

[0030]

[0031] (In equation (1), X1, Y1, R and Z are defined as described above.)

[0032] For Ar1, W, and Ar2 in Y1(“-Ar1-OWO-Ar2-”) in the above formula (1), including the preferred method, and the formula (D) described later A The same applies to Ar1, W, and Ar2 in ).

[0033] The "-N(Z)-Ar1-OWO-Ar2-N(Z)-" in the above formula (1) can be formed, for example, by using a diamine component containing the specific diamine described below as the raw material of the polymer, but is not limited to this method.

[0034] As the monovalent organic groups R and Z in the above formula (1), examples include monovalent hydrocarbon groups with 1 to 6 carbon atoms, and the methylene group of the hydrocarbon group is represented by -O-, -S-, -CO-, -COO-, -COS-, -NR. 3 -、-CO-NR 3 -、-Si(R 3 )2-(where R 3 A monovalent group A consisting of a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a monovalent group A formed by replacing a hydrogen atom of the aforementioned monovalent hydrocarbon group or a carbon atom of the aforementioned monovalent group A with a halogen atom, hydroxyl group, alkoxy group, nitro group, amino group, mercapto group, nitroso group, alkylsilyl group, alkoxysilyl group, silanol group, sulfinyl group, phospho group, carboxyl group, cyano group, sulfonyl group, acyl group, etc.; or a monovalent group having a heterocyclic ring.

[0035] As the monovalent organic groups in R and Z in the above formula (1), alkyl groups having 1 to 6 carbons, alkenyl groups having 2 to 6 carbons, alkynyl groups having 2 to 6 carbons, or tert-butoxycarbonyl groups are particularly preferred, alkyl groups having 1 to 3 carbons are even more preferred, and methyl groups are even more preferred.

[0036] From the viewpoint of properly obtaining the effects of the present invention, R and Z are each independently preferred to be hydrogen atoms or alkyl groups having 1 to 3 carbon atoms, more preferably hydrogen atoms or methyl groups.

[0037] As X1 in the above formula (1), for example, a tetravalent organic group derived from tetracarboxylic dianhydride or its derivatives described later can be cited. As a preferred embodiment of the tetracarboxylic dianhydride or its derivatives in X1, a preferred embodiment of the tetracarboxylic dianhydride or its derivatives that can be used in the synthesis of the polymer (P) described later can be cited.

[0038] <Specific diamine>

[0039] The polymer contained in the liquid crystal alignment agent of the present invention is, for example, selected from those comprising the following formula (D A The group consisting of at least one polymer (P) of a polyimide precursor obtained from the diamine component of the diamine (0) shown (hereinafter also referred to as a specific diamine).

[0040] H2N-Ar1-OWO-Ar2-NH2 (D A )

[0041] The above formula (D) A In ), Ar1, Ar2, and W are defined as described above.

[0042] The above formula (D) A In this context, W stands for *-(CH2). m From the viewpoint of appropriately obtaining the effects of the present invention, divalent organic groups with carbon numbers of 4 to 20, as indicated by -LA-*, are more preferably divalent organic groups with carbon numbers of 4 to 18, and even more preferably divalent organic groups with carbon numbers of 4 to 16.

[0043] Furthermore, L in W is preferably -OC (=O)-. A is preferably -(CH2). n -(n is an integer from 1 to 16.) or -(CH2) n’ -(n' is an integer from 2 to 16.) any divalent organic group formed by replacing any -CH2- with -O-, -C(=O)-, -NH-, -OC(=O)-, -C(=O)-O-, -C=C-, phenylene, or cyclohexylene.

[0044] From the viewpoint of obtaining high liquid crystal alignment, m is more preferably an integer of 2 to 6, more preferably an integer of 2 to 4, and even more preferably an integer of 2 or 4. n is preferably 1 to 13. In addition, fluorine atoms are preferred as halogen atoms that substitute for hydrogen atoms in W.

[0045] If we were to give a more preferred example of W, we could cite *-(CH2). p -OC(=O)-(CH2) q -*、*-(CH2) p -OC(=O)-(CH2)q -C(=O)-O-(CH2) r -、*-(CH2) p -C(=O)-O-(CH2) q -OC(=O)-(CH2) r -*、*-(CH2) p -OC(=O)-QC(=O)-O-(CH2) q -*(Q represents phenylene or cyclohexylene.), *-(CH2) p -C(=O)-OQOC(=O)-(CH2) q -*(Q represents phenylene or cyclohexylene.). Wherein, p is an integer from 1 to 6, preferably an integer from 2 to 6. q is an integer from 1 to 6, more preferably an integer from 2 to 6, and even more preferably an integer of 2, 4, or 6. r is an integer from 1 to 6, preferably an integer from 2 to 6.

[0046] As a response to the above equation (D) A The monovalent groups that substitute the divalent aromatic hydrogen atoms of Ar1 and Ar2 in the group can include halogen atoms, alkyl groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, fluoroalkyl groups with 1 to 10 carbon atoms, fluoroalkenyl groups with 2 to 10 carbon atoms, fluoroalkoxy groups with 1 to 10 carbon atoms, carboxyl groups, hydroxyl groups, alkyloxycarbonyl groups with 1 to 10 carbon atoms, cyano groups, nitro groups, etc. Among these, halogen atoms, alkyl groups with 1 to 5 carbon atoms, alkoxy groups with 1 to 5 carbon atoms, fluoroalkyl groups with 1 to 5 carbon atoms, or fluoroalkoxy groups with 1 to 5 carbon atoms are preferred.

[0047] Suitable examples of divalent aromatic groups represented by Ar1 and Ar2 include 1,4-phenylene, 1,3-phenylene, 2-methyl-1,4-phenylene, 2-ethyl-1,4-phenylene, 2-propyl-1,4-phenylene, 2-butyl-1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-tert-butyl-1,4-phenylene, 2-methoxy-1,4-phenylene, and 2-ethoxy-1,4-phenylene. 2-propoxy-1,4-phenylene, 2-butoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-dimethyl-1,4-phenylene, 4-methyl-1,3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl-1,4-phenylene, 4,4'-biphenylene, 2-methyl-4,4'-biphenylene, 2-ethyl-4,4'- Biphenylene, 2-propyl-4,4'-biphenylene, 2-butyl-4,4'-biphenylene, 2-tert-butyl-4,4'-biphenylene, 2-methoxy-4,4'-biphenylene, 2-ethoxy-4,4'-biphenylene, 2-fluoro-4,4'-biphenylene, 3-methyl-4,4'-biphenylene, 3-ethyl-4,4'-biphenylene, 3-propyl-4,4'-biphenylene, 3-butyl-4,4'-biphenylene -Biphenylene, 3-tert-butyl-4,4'-biphenylene, 3-methoxy-4,4'-biphenylene, 3-ethoxy-4,4'-biphenylene, 3-fluoro-4,4'-biphenylene, 2,2'-dimethyl-4,4'-biphenylene, 3,3'-dimethyl-4,4'-biphenylene, 3,3'-biphenylene, 5-methyl-3,3'-biphenylene, 5,5'-dimethyl-3,3'-biphenylene, etc.

[0048] As the above formula (D) A A preferred example of ) can be given by the following formula (d) A -1)~(d A -5). It should be noted that the following formula (d A -1)~(d A -5) The hydrogen atom on the benzene ring can be optionally replaced by a monovalent substituent. As a preferred specific example of such substituent, the above formula (D) can be cited. A The structure illustrated in the monovalent group in which the divalent aromatic hydrogen atoms of Ar1 and Ar2 in the group are substituted.

[0049]

[0050] (Polymer(P))

[0051] The polymer (P) contained in the liquid crystal alignment agent of the present invention is, for example, a polyimide precursor obtained using a diamine component containing the above-mentioned diamine (0), or a polyimide as an imide derivative of the polyimide precursor. The polyimide precursor is a polymer such as polyamic acid or polyamic acid ester that can be imidized to obtain a polyimide.

[0052] Polyamic acid (P'), the polyimide precursor of the above polymer (P), can be obtained by polymerization of a diamine component containing the above diamine (0) with a tetracarboxylic acid component. The above diamine (0) can be used alone or in combination of two or more.

[0053] The amount of diamine (0) used relative to the total diamine component is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more.

[0054] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (P) preferably comprises, in an amount of 5 mol% or more of the repeating unit (p1) and the imidized structure of the repeating unit (p1), more preferably 10 mol% or more, and even more preferably 20 mol% or more. It should be noted that the total here also includes the case where either the repeating unit (p1) or the imidized structure of the repeating unit (p1) is 0 mol%. The total cases mentioned below also include the case where one or more constituent elements are 0 mol%.

[0055] The diamine component used in the manufacture of the above-mentioned polyamic acid (P') may include diamines other than diamine (0) (hereinafter also referred to as other diamines). When other diamines are used in combination with the above-mentioned diamine (0), the amount of diamine (0) relative to the diamine component is preferably 90 mol% or less, more preferably 80 mol% or less.

[0056] Examples of other diamines are given below, but are not limited to these. The aforementioned other diamines can be used alone or in combination of two or more. Examples include: 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, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, and 3,3'-dihydroxy-4,4'-diaminobiphenyl. Biphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, and the following formula (d AL -1)~(d ALThe diamines shown in -10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)undecane, etc. 1,12-bis(3-aminophenoxy)dodecane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 1,4-phenylenebis(4-aminophenoxy)diphenyl ether Diamines with photo-oriented groups, such as 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; diamines with photo-oriented groups such as 4,4'-diaminoazobenzene or diaminodiphenylacetylene; 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N, Diamines with photopolymerizable groups at the ends, such as N-diallylaniline; diamines with free radical polymerization initiator functions, such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropionanone and 2-(4-(2-hydroxy-2-methylpropionyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines with amide bonds, such as 4,4'-diaminobenzoylaniline; and diamines with urea bonds, such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenylethyl)urea.3,3'-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-Diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, 2 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene; 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-(3-(1H-imidazol-1-yl)propyl-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-aniline, or heterocyclic diamines such as those shown in formulas (z-1) to (z-13) below, or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-benzidine Diamines with a diphenylamine structure, such as 1,N'-dimethyl-1,4-phenylenediamine, are diamines having at least one nitrogen-containing structure selected from the group consisting of nitrogen-containing heterocycles, secondary amino groups, and tertiary amino groups (hereinafter also referred to as specific nitrogen-containing structures). (The molecule does not contain an amino group bonded to a protecting group that is removed by heating and replaced with a hydrogen atom.) 2,4-Diaminophenol, 3,5-Diaminophenol, 3,5-Diaminobenzyl alcohol, 2,4-Diaminobenzyl alcohol, 4,6-Diaminoresorcinol, 4,4'-Diamino-3,3'-dihydroxybiphenyl;2,4-Diaminobenzoic acid, 2,5-Diaminobenzoic acid, 3,5-Diaminobenzoic acid, 4,4'-Diaminobiphenyl-3-carboxylic acid, 4,4'-Diaminodiphenylmethane-3-carboxylic acid, 4,4'-Diaminodiphenylethane-3-carboxylic acid, 4,4'-Diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-Diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-Diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-Diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-Diaminodiphenylmethane-3,3'- Diamines containing carboxyl groups, such as dicarboxylic acids, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acids, and 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acids; diamines containing carboxyl groups, such as 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indane-5-amine, and 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indane-6-amine; and those containing the group "-N(D)-" (D indicates that the diamine is produced by heating) as shown in formulas (5-1) to (5-6). The protecting group that is removed and replaced with a hydrogen atom, preferably a carbamate-based protecting group, more preferably a tert-butoxycarbonyl group. This includes diamines, cholesteryloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, lanosterol 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane, etc., which possess steroidal bone... Diamines with a siloxane bond, including diamines of formulas (V-1) to (V-2) below; diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; and diamines having two amino groups bonded to groups of any of the formulas (Y-1) to (Y-167) described in International Publication No. 2018 / 117239.

[0057]

[0058]

[0059] (Boc represents tert-butoxycarbonyl.)

[0060]

[0061]

[0062] In the above equation (V-1), m and n are integers from 1 to 3, satisfying 1 ≤ m + n ≤ 4. j is an integer of 0 or 1. X 1 It represents -(CH2) a -(a is an integer from 1 to 15.), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. R 1 This refers to a monovalent group, such as a fluorine atom, an alkyl group containing a fluorine atom having 1 to 10 carbon atoms, an alkoxy group containing a fluorine atom having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an alkoxyalkyl group having 2 to 10 carbon atoms. In the above formula (V-2), X 2 Represents -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. m, n, X 1 R 1 There are two cases in which the above definition applies independently.

[0063] When using other diamines in addition to the above-mentioned diamine (0), the amount of the other diamine used is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, relative to the total diamine components used.

[0064] The amount of the other diamines used is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, relative to all diamine components used in the manufacture of polymer (P).

[0065] (Tetracarboxylic acid component)

[0066] In the manufacture of the above-mentioned polyamic acid (P'), the tetracarboxylic acid component that reacts with the diamine component can be not only tetracarboxylic dianhydride, but also derivatives of tetracarboxylic dianhydride such as tetracarboxylic acid, tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, or tetracarboxylic acid dialkyl ester dihalides.

[0067] Examples of the aforementioned tetracarboxylic dianhydrides or their derivatives include acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, or their derivatives. More preferably, they comprise tetracarboxylic dianhydrides or their derivatives having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring. Particularly preferred are tetracarboxylic dianhydrides or their derivatives having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring.

[0068] It should be noted that aromatic tetracarboxylic acid dianhydrides are acid dianhydrides that contain at least one carboxyl group bonded to an aromatic ring, and are obtained by intramolecular dehydration of four carboxyl groups.

[0069] Acyclic aliphatic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, they do not necessarily have to consist solely of a chain hydrocarbon structure; a portion of them can also have an alicyclic or aromatic ring structure.

[0070] Alicyclic tetracarboxylic dianhydrides are acidic dianhydrides consisting of at least one carboxyl group bonded to an alicyclic structure, obtained by intramolecular dehydration of the four carboxyl groups. However, none of the four carboxyl groups are bonded to an aromatic ring. Furthermore, the structure need not be solely alicyclic; a portion of it may also have a chain hydrocarbon structure or an aromatic ring structure.

[0071] As a tetracarboxylic acid component that can be used in the manufacture of the above-mentioned polyamic acid (P'), it is preferable to include the following tetracarboxylic dianhydrides or their derivatives (in this invention, these are also collectively referred to as specific tetracarboxylic acid derivatives).

[0072] Acyclic aliphatic tetracarboxylic anhydrides such as 1,2,3,4-butanetetracarboxylic anhydride; 1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic anhydride, 1,2,3,4- Cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthyl-1,2-dicarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2] [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclic [2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxylic bicyclic [3.3.0]octane-2:4,6:8-dianhydride and other alicyclic tetracarboxylic dianhydrides; pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl sulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidene diphenyl dianhydride Aromatic tetracarboxylic anhydrides such as formic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, 2,2',3,3'-biphenyltetracarboxylic anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, ethylene glycol bis(triphenylene anhydride), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxobis(1,4-phenylene)bis(phthalic acid) dianhydride, or 4,4'-methylenebis(1,4-phenylene)bis(phthalic acid) dianhydride; and tetracarboxylic anhydrides as described in Japanese Patent Application Publication No. 2010-97188.

[0073] Preferred examples of the aforementioned specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,3- Difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxylated cyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran- 3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxylic acid bicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3 3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl sulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride, or derivatives thereof.

[0074] The proportion of the aforementioned specific tetracarboxylic acid derivative used relative to the total tetracarboxylic acid components used is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more.

[0075] (Liquid crystal alignment agent)

[0076] The liquid crystal alignment agent of the present invention is, for example, a liquid composition of a polymer (P) and other components used as needed, preferably dispersed or dissolved in a suitable solvent.

[0077] The total content of the polymer contained in the liquid crystal alignment agent of the present invention can be appropriately varied according to the desired thickness of the coating film. From the perspective of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and from the perspective of the storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred total polymer content is 2 to 8% by mass.

[0078] The content of polymer (P) used in this invention is preferably 1 to 100% by mass, more preferably 10 to 100% by mass, and particularly preferably 20 to 100% by mass, relative to the total amount of polymers contained in the liquid crystal alignment agent.

[0079] The liquid crystal alignment agent of the present invention may contain polymers other than polymer (P). Specific examples of other polymers include, based on polymer (P), polymers selected from the group consisting of: at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component that does not have the aforementioned specific diamine and a polyimide as an imide derivative of that polyimide precursor (also referred to as polymer (B) in the present invention), polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivative, and poly(meth)acrylate.

[0080] Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), and GSM301 (manufactured by Gifu Shellac Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by KURARAY CO.,LTD.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland).

[0081] From the perspective of reducing residual images originating from residual DC, polymer (B) is preferred.

[0082] The aforementioned other polymers can be used alone, or two or more can be used in combination. The proportion of other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, relative to a total of 100 parts by mass of the polymers contained in the liquid crystal alignment agent.

[0083] (Polymer(B))

[0084] Specific examples of the tetracarboxylic acid component used in the manufacture of the polymer (B), including preferred examples, include compounds identical to those exemplified in polymer (P). More preferably, the tetracarboxylic acid component used in the manufacture of polymer (B) comprises a tetracarboxylic dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring; further preferably, the aforementioned specific tetracarboxylic acid derivative; and most preferably, a more preferred example of using the aforementioned specific tetracarboxylic acid derivative.

[0085] Furthermore, relative to all tetracarboxylic acid components used in the manufacture of polymer (B), the amount of the aforementioned specific tetracarboxylic acid derivative is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more.

[0086] As a diamine component for obtaining polymer (B), examples include the diamine exemplified in the polymer (P) described above. Preferably, it comprises a diamine selected from those having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxyl group, and a hydroxyl group, or a diamine of the above formula (d). AL -1)~(d AL At least one diamine from the group consisting of the diamine shown in -10) and diamines having the above-described specific nitrogen-containing atomic structure (in this invention, these are also referred to as specific diamines (b)). The aforementioned diamine components may be used alone or in combination of two or more diamines.

[0087] When using the specific diamine (b) described above, its amount is preferably 10 mol% or more, more preferably 20 mol% or more, of all diamine components used in the manufacture of polymer (B). When using a diamine other than the specific diamine (b), its amount is preferably 90 mol% or less, more preferably 80 mol% or less, of all diamine components used in the manufacture of polymer (B).

[0088] (Manufacturing of polyamic acid)

[0089] The production of polyamic acid is carried out by reacting a diamine component with a tetracarboxylic acid component in an organic solvent. For the ratio of the tetracarboxylic acid component to the diamine component used in the polyamic acid production reaction, a ratio of 0.5 to 2 equivalents of the anhydride group of the tetracarboxylic acid component relative to 1 equivalent of the amino group of the diamine component is preferred, more preferably 0.8 to 1.2 equivalents. Similar to conventional polycondensation reactions, the closer the equivalent of the anhydride group of the tetracarboxylic acid component is to 1 equivalent, the larger the molecular weight of the resulting polyamic acid.

[0090] The reaction temperature for manufacturing polyamic acid is preferably -20 to 150°C, more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. The manufacturing of polyamic acid can be carried out at any concentration, preferably 1 to 50% by mass, more preferably 5 to 30% by mass. Alternatively, the reaction can be carried out at a high concentration initially, followed by the addition of solvent.

[0091] Specific examples of the aforementioned organic solvents include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolinone. Additionally, when the polymer has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether can be used.

[0092] (Manufacturing of polyamide esters)

[0093] Polyamates can be obtained, for example, by known methods such as the following: [I] reacting the polyamic acid obtained by the above methods with an esterifying agent; [II] reacting a tetracarboxylic acid diester with a diamine; [III] reacting a tetracarboxylic acid diester dihalide with a diamine.

[0094] (Manufacturing of polyimide)

[0095] For polyimides, polyimides can be obtained by cyclizing (imidizing) the aforementioned polyimide precursors such as polyamic acid or polyamic ester. It should be noted that the imidization rate mentioned in this specification refers to the proportion of imide groups in the total amount of imide groups and carboxyl groups (or their derivatives) derived from tetracarboxylic dianhydride or its derivatives. The imidization rate does not necessarily have to be 100% and can be adjusted arbitrarily according to the application and purpose.

[0096] Examples of methods for imidizing polyimide precursors include thermal imidization by directly heating a solution of the polyimide precursor or catalytic imidization by adding a catalyst to a solution of the polyimide precursor.

[0097] The temperature at which the polyimide precursor is thermally imidized in solution is preferably 100–400°C, more preferably 120–250°C, and preferably the process is carried out while the water generated by the imidization reaction is discharged from the system.

[0098] Catalytic imidization of polyimide precursors can be carried out 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. The amount of the basic catalyst is 0.5 to 30 moles of the amide group, preferably 2 to 20 moles, and the amount of the acid anhydride is 1 to 50 moles of the amide group, preferably 3 to 30 moles. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, or trioctylamine, among which pyridine is preferred due to its moderate basicity for the reaction to proceed. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, or pyromellitic anhydride, among which acetic anhydride facilitates purification after the reaction, and is therefore preferred. The imidization rate based on catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0099] When recovering the generated polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution can be precipitated by adding it to a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. After filtration and recovery, the polymer precipitated in the solvent can be dried at atmospheric or reduced pressure, at room temperature, or by heating. Furthermore, repeating the process 2 to 10 times to redissolve the recovered polymer in an organic solvent and then reprecipitating it reduces impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, or hydrocarbons; using three or more solvents selected from these sources further improves purification efficiency and is therefore preferred.

[0100] In manufacturing the polyimide precursor and polyimide of this invention, a suitable capping agent can be used together with a tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivative, and an amine component containing the aforementioned diamine, to produce a capped polymer. The capped polymer has the effect of increasing the film hardness of the oriented film obtained from the coating and improving the adhesion properties between the sealant and the oriented film.

[0101] Examples of polyimide precursors and ends of polyimides in this invention include amino, carboxyl, anhydride, or groups derived from the end-capping agents described below. Amino, carboxyl, and anhydride groups can be obtained through conventional condensation reactions or by sealing the ends with the end-capping agents described below.

[0102] Examples of capping agents include, for instance, acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynyl phthalic anhydride, etc.; dicarbonate diester compounds such as ditert-butyl dicarbonate and diallyl dicarbonate; acryloyl chloride, methacryl chloride, etc. Carbonyl chloride compounds such as nicotinic chloride; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine; and isocyanates with unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, etc.

[0103] The proportion of the capping agent used is preferably 0.01 to 20 moles, more preferably 0.01 to 10 moles, relative to a total of 100 moles of diamine components used.

[0104] The weight-average molecular weight (Mw) of the polyimide precursor and polyimide, converted from polystyrene and determined by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, more preferably 2,000 to 300,000, and even more preferably 10,000 to 50,000. Furthermore, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) of polystyrene determined by GPC, is preferably 15 or less, more preferably 10 or less. By being within this molecular weight range, good liquid crystal alignment of the liquid crystal display element can be ensured.

[0105] The organic solvent contained in the liquid crystal alignment agent of the present invention is not particularly limited as long as the polymer (P) and other polymers added as needed will dissolve uniformly. Examples include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllacticamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropaneamide, 3-butoxy- N,N-dimethylpropane amide, 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-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (these are also collectively referred to as good solvents), etc. Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropane amide, 3-butoxy-N,N-dimethylpropane amide, or γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass.

[0106] Furthermore, the organic solvent contained in the liquid crystal alignment agent is preferably a mixed solvent that combines the solvents mentioned above with solvents that improve the coatability and surface smoothness of the coating film when applying the liquid crystal alignment agent (also known as undesirable solvents). Specific examples of undesirable solvents are described below, but are not limited to these. The content of undesirable solvent is preferably 1 to 80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. The type and content of undesirable solvent are appropriately selected according to the coating apparatus, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

[0107] Examples of undesirable solvents include, for example, diisopropyl ether, diisobutyl ether, diisobutylcarbitol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and 1-(2-butoxyethoxy)-2-propanol. 2-(2-Butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0108] Among them, diisobutylcarbitol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone are preferred.

[0109] Examples of preferred solvent combinations for both good and poor solvents include N-methyl-2-pyrrolidone with ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone with propylene glycol diacetate, N,N-dimethyllacticamide with diisobutyl ketone, N-methyl-2-pyrrolidone with ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone with ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone with ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N... N-methyl-2-pyrrolidone with ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone with ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone with ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone with dipropylene glycol dimethyl ether, N,N-dimethyllacticamide with ethylene glycol monobutyl ether, N,N-dimethyllacticamide with propylene glycol diacetate, N-ethyl-2-pyrrolidone with diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone with diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2-pyrrolidone with diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-Dimethyllacticamide with diethylene glycol diethyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone with N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone N-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone with 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone with 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone with γ-butyrolactone with propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone with γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone with γ- Butyrolactone and propylene glycol monobutyl ether and diisobutylcarbitol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2-pyrrolidone Alkyl ketones with N,N-dimethyllactic acid and diisobutyl ketone; N-methyl-2-pyrrolidone with ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate; γ-butyrolactone with ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone with ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether; N-methyl-2-pyrrolidone with 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether; N-ethyl-2-pyrrolidone with cyclohexyl acetate and 4-hydroxy-4-methyl-2-pentanone; cyclohexanone with propylene glycol monomethyl ether; cyclopentanone with propylene glycol monomethyl ether; N-methyl-2-pyrrolidone with cyclohexanone and propylene glycol monomethyl ether, etc.

[0110] (Liquid crystal alignment agent)

[0111] The liquid crystal alignment agent of the present invention may contain additional components (hereinafter also referred to as additive components) in addition to the above-mentioned polymer (P), the other polymers mentioned above, and the organic solvents mentioned above. Examples of such additive components include: at least one crosslinking compound selected from the group consisting of a crosslinking compound having at least one substituent selected from ethylene oxide, oxadiazonyl, terminal isocyanate group, oxazoline group, cyclic carbonate group, hydroxyl group, and alkoxy group; and crosslinking compounds having polymerizable unsaturated groups; functional silane compounds; metal chelates; curing accelerators; surfactants; antioxidants; sensitizers; preservatives; and compounds for adjusting the dielectric constant and resistance of the obtained liquid crystal alignment film.

[0112] Preferred examples of the aforementioned crosslinking compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromonepentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, and bisphenol A epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical Corporation). 807 (manufactured by Mitsubishi Chemical Corporation) and other bisphenol F type epoxy resins, YX-8000 (manufactured by Mitsubishi Chemical Corporation) and other hydrogenated bisphenol A type epoxy resins, YX6954BH30 (manufactured by Mitsubishi Chemical Corporation) and other epoxy resins containing a biphenyl backbone, EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.) and other phenolic varnish type epoxy resins, EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.) and other (ortho, meta, para-)cresol phenolic varnish type epoxy resins, TEPIC (manufactured by Nissan Chemical Co., Ltd.) and other triglycidyl isocyanurate, CELLOXIDE 2021P (Daicel Chemical Industries, Ltd.).Compounds containing tertiary nitrogen atoms, such as alicyclic epoxy resins, N,N,N',N'-tetraglycidyl-m-phenylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; compounds containing two or more ethylene oxide groups, such as tetra(glycidyloxymethyl)methane; compounds containing two or more oxobutyl groups as described in paragraphs

[0170] to

[0175] of WO2011 / 132751; CORONATE AP Stand M, CORONATE 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation); TAKENATE Compounds with capped isocyanate groups, such as B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Ltd.); compounds with oxazoline groups, such as 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris-(2-oxazoline-2)-benzene, and EPOCROS (manufactured by Nippon Shokubai Co., Ltd.); compounds with cyclic carbonate groups as described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577; n,n,n',n'-tetra(2-hydroxyethyl)hexamethylenediamine, Compounds containing hydroxyl or alkoxy groups, such as 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; and compounds shown in the following descriptions: glycerol mono(meth)acrylate, glycerol di(meth)acrylate (a mixture of 1,2- and 1,3-methacrylates), glycerol tri(meth)acrylate, glycerol 1,3-diglyceryl alcohol di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.

[0113] The content of the aforementioned crosslinking compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0114] Examples of compounds used to adjust the dielectric constant and resistance include monoamines such as 3-pyridinemethylamine, which have nitrogen-containing aromatic heterocycles. The content of the monoamine having nitrogen-containing aromatic heterocycles is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0115] Preferred examples of the aforementioned functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureopropyltrimethoxysilane, 3-ureopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-epoxypropoxypropylmethyldimethoxysilane. The silanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane. The content of the functional silane compound is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, relative to 100 parts by weight of the polymer component contained in the liquid crystal alignment agent.

[0116] The concentration of solid components in the liquid crystal alignment agent (the proportion of the total mass of components other than the solvent in the total mass of the liquid crystal alignment agent) should be appropriately selected considering factors such as viscosity and volatility, and is preferably 1 to 10 by mass.

[0117] The particularly preferred range of solid component concentration varies depending on the method used to coat the liquid crystal alignment agent onto the substrate. For example, when using spin coating, the solid component concentration is particularly preferably 1.5 to 4.5% by mass. When using printing, the solid component concentration is particularly preferably 3 to 9% by mass, thereby achieving a solution viscosity of 12 to 50 mPa·s. When using inkjet printing, the solid component concentration is particularly preferably 1 to 5% by mass, thereby achieving a solution viscosity of 3 to 15 mPa·s. The temperature for preparing the polymer composition is preferably 10 to 50°C, more preferably 20 to 30°C.

[0118] (Liquid crystal alignment film and liquid crystal display element)

[0119] The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the above-described liquid crystal alignment agent. The operating mode of the liquid crystal display element is not particularly limited; for example, it can be applied to various operating modes such as TN type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), in-plane conversion type (IPS type, FFS type), and optically compensated bending type (OCB type).

[0120] The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following steps (1) to (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4-2) and (4-4), or a method including steps (1) to (3), (4-3) and (4-4).

[0121] <Process (1): The process of coating the liquid crystal alignment agent onto the substrate>

[0122] Step (1) is the process of coating a liquid crystal alignment agent onto a substrate. A specific example of step (1) is as follows.

[0123] On one side of a substrate with a patterned transparent conductive film, a liquid crystal alignment agent is applied using a suitable coating method such as roll coating, spin coating, printing, or inkjet coating. The substrate material is not particularly limited as long as it is highly transparent; acrylic or polycarbonate plastics can also be used with glass or silicon nitride. Furthermore, in reflective liquid crystal display elements, if only a single-sided substrate is used, an opaque material such as a silicon wafer can be used, and the electrodes can be made of light-reflective materials such as aluminum. Additionally, when manufacturing IPS or FFS type liquid crystal display elements, a substrate with electrodes including a patterned comb-shaped transparent conductive film or metal film and a counter substrate without electrodes can be used.

[0124] Methods for coating liquid crystal alignment agents onto a substrate to form a film include screen printing, offset printing, flexographic printing, inkjet printing, and spray printing. Among these, inkjet-based coating and film formation methods can be appropriately used.

[0125] <Process (2): The process of firing the coated liquid crystal alignment agent>

[0126] Step (2) is a process of firing the liquid crystal alignment agent coated on the substrate to form a film. A specific example of step (2) is as follows.

[0127] In step (1), after the liquid crystal alignment agent is coated onto the substrate, the solvent can be evaporated or the polyamic acid can be thermally imidized by heating means such as a hot plate, a thermally circulating oven, or an IR (infrared) oven. The drying and firing steps after coating the liquid crystal alignment agent can be performed at any temperature and for any time, and can be repeated multiple times. For example, the firing temperature for the liquid crystal alignment agent can be 40 to 180°C. From the viewpoint of shortening the process, it can be performed at 40 to 150°C. There is no particular limitation on the firing time, and examples include 1 to 10 minutes or 1 to 5 minutes. In the case of thermal imidization of polyamic acid, after the above steps, for example, a firing step can be added at 150 to 300°C or 150 to 250°C. There is no particular limitation on the firing time, and examples include 5 to 40 minutes or 5 to 30 minutes.

[0128] If the film thickness of the fired film is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, 5 to 300 nm is preferred, and 10 to 200 nm is more preferred.

[0129] <Step (3): The step of oriented processing of the film obtained in step (2)>

[0130] Step (3) is a step of aligning the film obtained in step (2) as appropriate. That is, in horizontally aligned liquid crystal display elements such as IPS or FFS, the coating is treated to impart alignment capability. On the other hand, in vertically aligned liquid crystal display elements such as VA or PSA, the formed coating can be used directly as a liquid crystal alignment film, and the coating can be treated to impart alignment capability. Examples of alignment treatment methods for liquid crystal alignment films include rubbing treatment and photo-alignment treatment. Examples of photo-alignment treatment methods include irradiating the surface of the film with radiation rays polarized in a certain direction, and, as appropriate, performing a heating treatment at a temperature of 150 to 250°C to impart liquid crystal alignment (also known as liquid crystal alignment capability). As radiation rays, ultraviolet light or visible light with a wavelength of 100 to 800 nm can be used. Among them, ultraviolet light with a wavelength of 100 to 400 nm is preferred, and more preferably ultraviolet light with a wavelength of 200 to 400 nm.

[0131] The preferred exposure dose of the above-mentioned radiation is 1 to 10,000 mJ / cm. 2 More preferably, 100–5,000 mJ / cm³ 2 Furthermore, to improve liquid crystal alignment when irradiated with radiation, the substrate having the aforementioned film can be heated at 50–250°C while being irradiated. This method allows the liquid crystal alignment film to stably align the liquid crystal molecules in a specific direction.

[0132] Furthermore, the liquid crystal alignment film that has been irradiated with polarized radiation using the above method can also be subjected to contact treatment with water or solvent, or the liquid crystal alignment film that has been irradiated with radiation can be subjected to heat treatment.

[0133] The solvent used in the above-described contact treatment is not particularly limited as long as it dissolves the decomposition products generated by the film through irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. One solvent or a combination of two or more solvents may be used.

[0134] The temperature for heat treatment of the above-mentioned irradiated coating is more preferably 50–300°C, and even more preferably 120–250°C. The heat treatment time is preferably set to 1–30 minutes.

[0135] <Process (4): Process of manufacturing liquid crystal cells>

[0136] Prepare two substrates on which liquid crystal alignment films are formed as described above, and place a liquid crystal composition between the two substrates arranged opposite each other. Specifically, the following two methods can be cited.

[0137] In the first method, two substrates are first arranged opposite each other with gaps (cell gaps) between them, with each liquid crystal alignment film facing each other. Next, the peripheries of the two substrates are bonded together using a sealant. After injecting a liquid crystal composition into the cell gaps defined by the substrate surfaces and the sealant and bringing it into contact with the film surfaces, the injection holes are sealed.

[0138] Another method is known as the ODF (One Drop Fill) method. A sealant, for example, that is UV-curable, is applied to a predetermined area on one of two substrates on which a liquid crystal alignment film has been formed. Then, a liquid crystal composition is dropped onto predetermined portions of the liquid crystal alignment film. The other substrate is then bonded together with the liquid crystal alignment film facing each other, so that the liquid crystal composition spreads across the entire surface of the substrate in contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. Ideally, in either method, the mixture is further heated to a temperature at which the liquid crystal composition becomes an isotropic phase, and then cooled to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0139] It should be noted that when the coating is rubbed, the two substrates are arranged opposite each other at a predetermined angle, such as orthogonal or antiparallel, with the rubbing directions of each coating being opposite to each other.

[0140] As a sealant, for example, epoxy resin containing a curing agent and alumina spheres as spacers can be used. As for the liquid crystal composition, there are no particular limitations; it can be a composition containing at least one liquid crystal compound (liquid crystal molecule). Examples include liquid crystal compositions exhibiting a nematic phase (hereinafter also referred to as nematic liquid crystals), liquid crystals exhibiting a smectic phase, or liquid crystal compositions exhibiting a cholesteric phase, with nematic liquid crystals being preferred. Furthermore, various liquid crystal compositions with positive or negative dielectric anisotropy can be used. It should be noted that, hereinafter, liquid crystal compositions with positive dielectric anisotropy are also referred to as positive liquid crystals, and liquid crystal compositions with negative dielectric anisotropy are also referred to as negative liquid crystals.

[0141] The liquid crystal composition described above may contain liquid crystal compounds having fluorine atoms, hydroxyl groups, amino groups, fluorine-containing groups (e.g., trifluoromethyl), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, isothiocyanate groups, heterocyclic groups, cycloalkanes, cycloolefins, steroid skeletons, benzene rings, or naphthalene rings. It may also contain compounds having two or more rigid sites (mesogen skeletons) exhibiting liquid crystal properties within the molecule (e.g., rigid biphenyl structures or bimesogen compounds formed by connecting two biphenyl structures with alkyl groups).

[0142] Furthermore, from the viewpoint of improving liquid crystal orientation, the above-mentioned liquid crystal composition may also contain additives. Examples of such additives include photopolymerizable monomers such as compounds with polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck); antioxidants; ultraviolet absorbers; pigments; defoamers; polymerization initiators; or polymerization inhibitors.

[0143] Examples of positive liquid crystal displays include Merck's ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081.

[0144] Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-7026, and MLC-7026-100 manufactured by Merck.

[0145] In addition, as a liquid crystal containing compounds with polymerizable groups, Merck's MLC-3023 is an example.

[0146] The liquid crystal alignment agent of the present invention is also preferably used in a liquid crystal display element (PSA type liquid crystal display element) having a liquid crystal layer between a pair of substrates having electrodes, which is manufactured by the following process: a liquid crystal composition comprising a polymerizable compound that is polymerized by at least one of active energy rays and heat is disposed between a pair of substrates, a voltage is applied between the electrodes, and the polymerizable compound is polymerized by at least one of irradiation by active energy rays and heating.

[0147] Furthermore, the liquid crystal alignment agent of the present invention is also preferably used in a liquid crystal display element (SC-PVA type liquid crystal display element) having a liquid crystal layer between a pair of substrates having electrodes, which is manufactured by the following process: a liquid crystal alignment film containing polymeric groups that are polymerized by at least one of active energy rays and heat is disposed between the pair of substrates, and a voltage is applied between the electrodes.

[0148] <Process (4-2): In the case of PSA type liquid crystal display element>

[0149] Except for injecting or dropping the liquid crystal composition containing the polymerizable compound, the procedure is the same as described in (4) above. Examples of polymerizable compounds include polymeric compounds having one or more polymerizable unsaturated groups such as acrylate groups or methacrylate groups within their molecules.

[0150] <Process (4-3): In the case of SC-PVA type liquid crystal display element>

[0151] A liquid crystal display element can be manufactured by performing the same operation as described in (4) above, followed by the ultraviolet irradiation process described later. Using this method, similar to the case of manufacturing the PSA-type liquid crystal display element described above, a liquid crystal display element with excellent response speed under low light irradiation can be obtained. The compound having polymerizable groups can be a compound having one or more of the above-described polymeric unsaturated groups within its molecule, and its content relative to 100 parts by mass of the total polymer component is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass. In addition, the polymer used in the liquid crystal alignment agent can have the above-described polymerizable groups. For example, a polymer obtained by using a diamine component containing a diamine with the above-described photopolymerizable groups at the end in the reaction can be cited as an example.

[0152] <Process (4-4): Ultraviolet Irradiation Process>

[0153] The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (4-2) or (4-3) above. The applied voltage can be, for example, DC or AC of 5 to 50 V. The irradiation light can be, for example, ultraviolet light or visible light with wavelengths of 150 to 800 nm, preferably ultraviolet light with wavelengths of 300 to 400 nm. The light source can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser. The irradiation dose is preferably 1,000 to 200,000 J / m². 2 More preferably, it is 1,000 to 100,000 J / m 2 .

[0154] Then, a polarizing plate is attached to the outer surface of the liquid crystal cell as needed, thereby obtaining a liquid crystal display element. Examples of polarizing plates attached to the outer surface of the liquid crystal cell include polarizing plates made by holding the edges of a cellulose acetate protective film with polyvinyl alcohol stretched and oriented to absorb iodine, known as "H film", or polarizing plates formed by the H film itself.

[0155] The IPS substrate, used as a comb electrode substrate in IPS mode, includes: a substrate, a plurality of linear electrodes formed on the substrate and configured in a comb shape, and a liquid crystal alignment film formed on the substrate to cover the linear electrodes.

[0156] It should be noted that the FFS substrate used as the comb electrode substrate in the FFS mode has: a substrate, a surface electrode formed on the substrate, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb shape, and a liquid crystal alignment film formed on the insulating film in a manner that covers the linear electrodes.

[0157] Figure 1 This is a schematic partial cross-sectional view showing an example of a lateral electric field liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element.

[0158] Figure 1 In the illustrated lateral electric field liquid crystal display element 1, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes: a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the substrate 2a to cover the linear electrodes 2b. The counter substrate 4 includes: a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2c is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also, similarly, the liquid crystal alignment film of the present invention.

[0159] In the transverse electric field liquid crystal display element 1, when a voltage is applied to the linear electrode 2b, an electric field is generated between the linear electrodes 2b as shown by the electric field line L.

[0160] Figure 2 The schematic partial cross-sectional view shown is for illustrating other examples of the lateral electric field liquid crystal display element of the present invention, specifically an example of an FFS mode liquid crystal display element.

[0161] Figure 2 In the illustrated lateral electric field liquid crystal display element 1, liquid crystal 3 is held between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes: a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-like pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f to cover the linear electrodes 2g. The counter substrate 4 includes: a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2h is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also, like the liquid crystal alignment film of the present invention.

[0162] When a voltage is applied to the surface electrode 2e and the linear electrode 2g in the transverse electric field liquid crystal display element 1, an electric field is generated between the surface electrode 2e and the linear electrode 2g as shown by the electric field line L.

[0163] Example

[0164] The following examples illustrate the invention in more detail, but the invention is not limited to these examples. The abbreviations of the compounds used and the methods for determining their properties are as follows.

[0165] (Organic solvents)

[0166] NMP: N-methyl-2-pyrrolidone; GBL: γ-butyrolactone

[0167] BCS: Butyl cellosol, BCA: Butyl cellosol acetate

[0168] THF: Tetrahydrofuran; DMF: N,N-Dimethylformamide

[0169] (acid dianhydride)

[0170]

[0171] (Diamine)

[0172]

[0173] (additive)

[0174]

[0175] <Viscosity Measurement>

[0176] The viscometer was a TVE-22H (manufactured by Toki Sangyo Co., Ltd.) of type E, with a sample volume of 1.1 mL and a conical rotor TE-1 (1°34', R24) at a temperature of 25°C.

[0177] <Determination of molecular weight>

[0178] The determination was performed using the following room-temperature GPC (gel permeation chromatography) apparatus, and Mn and Mw were calculated in the form of polyethylene glycol and polyethylene oxide conversion values.

[0179] GPC apparatus: GPC-101 (manufactured by Showa Denko Corporation), columns: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko Corporation) in series, column temperature: 50°C, eluent: N,N-dimethylformamide (as an additive, lithium bromide monohydrate (LiBr·H2O) 30 mmol / L, phosphoric acid·anhydrous crystals (orthophosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L), flow rate: 1.0 mL / min

[0180] Standard samples used for preparing the standard curve: TSK standard polyethylene oxide (molecular weight; about 900,000, 150,000, 100,000 and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; about 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratories Ltd.).

[0181] [Synthesis of monomers]

[0182] DA-1 to DA-3 are novel compounds not disclosed in the literature. The products of the monomer synthesis examples 1 to 3 described below were obtained through... 1 Identification was performed using H-NMR analysis. The analytical conditions are as follows.

[0183] Device: BRUKER ADVANCE III-500MHz

[0184] Determination solvent: Deuterated dimethyl sulfoxide (DMSO-d6)

[0185] Reference material: Tetramethylsilane (TMS) (δ 0.0 ppm for 1 H)

[0186] <Monomer Synthesis Example 1: Synthesis of DA-1>

[0187]

[0188] 2-(4-nitrophenoxy)ethanol (30.0 g, 0.164 mol) was reacted with THF (120 g) and pyridine (14.0 g, 0.177 mol) while being cooled in an ice bath (0 °C) with stirring. Adipic acid dichloroisocyanurate (17.0 g, 0.0929 mol) dissolved in THF (60 g) was added dropwise to the resulting solution. After the addition was complete, the mixture was stirred at room temperature (25 °C) for 20 minutes, followed by stirring at 45 °C for 18 hours. After the reaction was complete, the mixture was cooled to room temperature (25 °C), and water (540 g) was added to induce crystallization. The crystals obtained through filtration were dried to obtain crude crystals (39 g). THF (300 g) was added to the crude crystals, and the mixture was heated and stirred at 70 °C. Methanol (400 g) was added while cooling in an ice bath (0 °C) to induce recrystallization. The crystals were filtered and dried to obtain DA-1-1 (yield: 34.0 g, 0.0713 mol, 88%).

[0189] 1 H-NMR (500MHz) in DMSO-d6: δ (ppm) = 8.19 (d, J = 9.5Hz, 4H), 7.16 (d, J = 9.5Hz, 4H), 4.37 (q, 4H), 4.34 (q, 4H), 2.33 (t, 4H), 1.54-1.51 (m, 4H).

[0190] The DA-1-1 (29.0 g, 0.0609 mol) obtained above was treated with DMF (290 g) and nitrogen replacement was performed. Then, carbon-supported palladium (5% Pd carbon powder (containing water), K type, manufactured by NECHEMCAT CORPORATION) (2.32 g) was added, and nitrogen replacement was performed again. A hydrogen-Tydra sampling bag was installed, and the mixture was heated and stirred at 50 °C for 18 hours. After the reaction was completed, the carbon-supported palladium was removed by a membrane filter, and water (1000 g) was added to the filtrate and stirred to induce crystallization. The filtrate was filtered to obtain crude crystals (24 g). THF (92 g) was added to the crude crystals, and the mixture was heated and stirred at 50 °C to wash the slurry. After cooling in an ice bath (0 °C), the slurry was filtered and dried to obtain crystals (22 g). DMF (66 g) was added to the obtained crystals, and the mixture was heated and stirred at 50 °C. After cooling in an ice bath (0 °C), acetonitrile (88 g) was added for recrystallization. The crystals were filtered and dried to give DA-1 (yield: 17.0 g, 0.0408 mol, 67%).

[0191] 1H-NMR(500MHz)in DMSO-d6: δ (ppm) = 6.65 (d, J = 9.0Hz, 4H), 6.49 (d, J = 9.0Hz, 4H), 4.60 (s, 4H), 4.26 (t, 4H), 4.01 (t, 4H), 2.33 (t, 4H), 1.56-1.53 ​​(m, 4H).

[0192] <Monomer Synthesis Example 2: Synthesis of DA-2>

[0193]

[0194] 4'-Hydroxy-4-nitrobiphenyl (30.0 g, 0.139 mol) was added to DMF (210 g) and potassium carbonate (48.0 g, 0.347 mol), and the mixture was heated and stirred at 80 °C for 30 minutes. 2-Bromoethanol (26 g, 0.208 mol) dissolved in DMF (30 g) was added dropwise to the resulting solution, and the mixture was heated and stirred at 80 °C for 18 hours. After the reaction was complete, the mixture was cooled to room temperature (25 °C), and water (480 g) was added to induce crystallization. The crystals were filtered and dried. Methanol was added to the filtrate, and the mixture was heated and stirred at 50 °C to wash the slurry. After cooling to room temperature (25 °C), the mixture was filtered again. The filtrate was concentrated, and the same process was repeated until crystallization occurred three times. The crystals were then removed and dried to obtain DA-2-1 (yield: 31.0 g, 0.120 mol, 86%).

[0195] 1 H-NMR(500MHz)in DMSO-d6: δ (ppm) = 8.27 (d, J = 8.5Hz, 2H), 7.92 (d, J = 9.0Hz, 2H), 7.76 (d, J = 8.5Hz , 2H), 7.09 (d, J=9.0Hz, 2H), 4.89 (t, 1H), 4.09-4.06 (m, 2H), 3.76-3.73 (m, 2H).

[0196] The DA-2-1 (26.0 g, 0.100 mol) obtained above was added to THF (230 g) and pyridine (8.20 g, 0.104 mol) while stirring and cooling in an ice bath (0 °C). Adipic acid dichloroisocyanurate (9.9 g, 0.0541 mol) dissolved in THF (26 g) was added dropwise to the solution. After the addition was complete, the mixture was stirred at room temperature (25 °C) for 5 hours, followed by stirring at 45 °C for 1 hour. After the reaction was complete, the mixture was cooled to room temperature (25 °C), and water (765 g) was added to induce crystallization. The crystals were filtered and dried to obtain crude crystals (29 g). THF (290 g) was added to the crude crystals, and the mixture was heated and stirred at 60 °C. Then, methanol (290 g) was added while cooling in an ice bath (0 °C) to induce recrystallization. The crystals were filtered and dried to obtain DA-2-2 (yield: 24.0 g, 0.0382 mol, 76%).

[0197] 1 H-NMR(500MHz)in DMSO-d6: δ (ppm) = 8.25 (d, J = 9.0Hz, 4H), 7.90 (d, J = 8.5Hz, 4H), 7.74 (d, J = 8.5Hz, 4H ), 7.09 (d, J=8.5Hz, 4H), 4.37 (t, 4H), 4.25 (t, 4H), 2.34 (t, 4H), 1.57-1.54 (m, 4H).

[0198] The DA-2-2 (25.0 g, 0.0398 mol) obtained above was added to DMF (490 g) and subjected to nitrogen replacement. Then, carbon-supported palladium (5% Pd carbon powder (containing water), K type, manufactured by NECHEMCAT CORPORATION) (2.00 g) was added, and nitrogen replacement was performed again. A hydrogen tyrade sampling bag was installed, and the mixture was stirred at room temperature (25 °C) for 48 hours. After the reaction was completed, the carbon-supported palladium was removed through a membrane filter, and the filtrate was concentrated until crystals began to precipitate (the remaining amount of DMF: approximately 140 g). The filtrate was heated and stirred at 55 °C until completely dissolved, cooled to room temperature (25 °C), and acetonitrile (80 g) was added to induce crystallization. The crystals were filtered and dried to obtain DA-2 (yield: 20.0 g, 0.0352 mol, 88%).

[0199] 1H-NMR(500MHz)in DMSO-d6: δ (ppm) = 7.43 (d, J = 9.0Hz, 4H), 7.27 (d, J = 8.5Hz, 4H), 6.93 (d, J = 8.5Hz, 4H), 6.6 1(d, J=8.5Hz, 4H), 5.10(s, 4H), 4.33(t, 4H), 4.17(t, 4H), 2.33(t, 4H), 1.56-1.54(m, 4H).

[0200] <Monomer Synthesis Example 3: Synthesis of DA-3>

[0201]

[0202] 2-(4-nitrophenoxy)ethanol (35.7 g, 0.195 mol) was added to THF (180 g) and pyridine (18.4 g, 0.232 mol) while stirring and cooling in an ice bath (0 °C). Oxalic acid dichloroisocyanurate (19.6 g, 0.0929 mol) dissolved in THF (60 g) was added dropwise to the resulting solution. After the addition was complete, the mixture was stirred at room temperature (25 °C) for 20 minutes, followed by stirring at 45 °C for 18 hours. After the reaction was complete, the mixture was cooled to room temperature (25 °C), and water (400 g) was added to induce crystallization. The crystals obtained through filtration were dried to obtain crude crystals (35 g). THF (180 g) was added to the crude crystals, and the mixture was heated and stirred at 70 °C while recrystallizing by adding methanol (400 g) while cooling in an ice bath (0 °C). The crystals were filtered and dried to obtain DA-3-1 (yield: 30.9 g, 0.0613 mol, 66%).

[0203] 1 H-NMR(500MHz)in DMSO-d6: δ (ppm) = 8.19 (d, J = 9.5Hz, 4H), 7.17 (d, J = 9.5Hz, 4H), 4.38-4.34 (m, 8H), 2.28 (t, 4H), 1.48-1.45 (m, 4H), 1.25-1.23 (m, 4H).

[0204] The DA-3-1 (30.9 g, 0.0613 mol) obtained above was added to THF (770 g) and subjected to nitrogen replacement. Then, carbon-supported palladium (5% Pd carbon powder (containing water), K type, prepared by NECHEMCAT CORPORATION) (3.1 g) was added, and nitrogen replacement was performed again. A hydrogen-tetrafluoroethylene (HTPE) sampling bag was installed, and the mixture was heated and stirred at 45 °C for 24 hours. After the reaction was completed, the carbon-supported palladium was removed by a membrane filter. The filtrate was concentrated, and isopropanol (240 g) was added while stirring to induce crystallization. The crystals were filtered and dried to obtain DA-3 (yield: 24.9 g, 0.0560 mol, 91%).

[0205] 1 H-NMR(500MHz)in DMSO-d6: δ (ppm) = 6.66 (d, J = 9.0Hz, 4H), 6.50 (d, J = 9.0Hz, 4H), 4.61 (s, 4H), 4.2 6(t, 4H), 4.01(t, 4H), 2.31-2.28(m, 4H), 1.51-1.47(m, 4H), 1.28-1.24(m, 4H).

[0206] [Polymer Synthesis]

[0207] <Synthesis example 1>

[0208] DA-1 (2.29 g, 5.50 mmol) and NMP (16.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. CA-1 (1.15 g, 5.27 mmol) and NMP (8.10 g) were added to the resulting diamine solution while stirring under water cooling. The mixture was stirred at 50 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-1) (viscosity: 239 mPa·s). The polyamic acid had a Mn of 10,094 and a Mw of 33,198.

[0209] <Synthesis example 2>

[0210] DA-1 (2.54 g, 6.10 mmol) and NMP (18.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-2 (1.14 g, 5.81 mmol) and NMP (8.00 g) were added. The mixture was stirred at room temperature for 18 hours to obtain a 12% by mass solution of polyamic acid (A-2) (viscosity: 241 mPa·s). The polyamic acid had a Mn of 12,332 and a Mw of 46,258.

[0211] <Synthesis example 3>

[0212] DA-1 (3.12 g, 7.50 mmol) and NMP (22.9 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-3 (1.60 g, 7.14 mmol) and NMP (10.8 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-3) (viscosity: 282 mPa·s). The polyamic acid had a Mn of 10,704 and a Mw of 39,144.

[0213] <Synthesis example 4>

[0214] DA-3 (2.58 g, 5.80 mmol) and NMP (23.2 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-3. While stirring the resulting diamine solution under water cooling, CA-3 (1.21 g, 5.40 mmol) and NMP (4.4 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-4) (viscosity: 190 mPa·s). The polyamic acid had a Mn of 10,832 and a Mw of 43,395.

[0215] <Synthesis example 5>

[0216] DA-1 (2.27 g, 5.44 mmol), DA-6 (0.390 g, 1.36 mmol), and NMP (19.5 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-3 (1.45 g, 6.46 mmol) and NMP (10.1 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-5) (viscosity: 327 mPa·s). The polyamic acid had a Mn of 10,534 and a Mw of 37,647.

[0217] <Synthesis example 6>

[0218] DA-1 (1.46 g, 3.50 mmol), DA-6 (1.00 g, 3.50 mmol), and NMP (18.0 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-3 (1.48 g, 6.58 mmol) and NMP (10.8 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-6) (viscosity: 225 mPa·s). The polyamic acid had a Mn of 10,400 and a Mw of 25,285.

[0219] <Synthesis Example 7>

[0220] DA-1 (0.73 g, 1.75 mmol), DA-6 (1.50 g, 5.24 mmol), and NMP (20.1 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-3 (1.47 g, 6.56 mmol) and NMP (6.9 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-7) (viscosity: 236 mPa·s). The polyamic acid had a Mn of 10,634 and a Mw of 31,097.

[0221] <Synthesis example 8>

[0222] DA-3 (0.80 g, 1.80 mmol), DA-6 (1.55 g, 5.41 mmol), and NMP (21.1 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-3. While stirring the resulting diamine solution under water cooling, CA-3 (1.52 g, 6.78 mmol) and NMP (7.0 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-8) (viscosity: 209 mPa·s). The polyamic acid had a Mn of 9,900 and a Mw of 28,856.

[0223] <Synthesis Example 9>

[0224] DA-1 (1.67 g, 4.01 mmol), DA-4 (0.98 g, 4.01 mmol), and NMP (23.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-1. While stirring the resulting diamine solution under water cooling, CA-1 (1.63 g, 7.47 mmol) and NMP (7.6 g) were added. The mixture was stirred at 50 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-9) (viscosity: 300 mPa·s). The polyamic acid had a Mn of 9,351 and a Mw of 31,020.

[0225] <Synthesis example 10>

[0226] DA-2 (2.50 g, 4.40 mmol) and NMP (19.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-2. While stirring the resulting diamine solution under water cooling, CA-1 (0.873 g, 4.00 mmol) and NMP (5.10 g) were added. The mixture was stirred at 50 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-10) (viscosity: 231 mPa·s). The polyamic acid had a Mn of 9,716 and a Mw of 25,390.

[0227] <Synthesis Example 11>

[0228] DA-2 (2.79 g, 4.90 mmol) and NMP (20.4 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-2. While stirring the resulting diamine solution under water cooling, CA-2 (0.88 g, 4.49 mmol) and NMP (6.35 g) were added, and the mixture was stirred at room temperature for 18 hours to obtain a 12% by mass solution of polyamic acid (A-11) (viscosity: 230 mPa·s). The polyamic acid had a Mn of 11,774 and a Mw of 32,286.

[0229] <Synthesis example 12>

[0230] DA-6 (3.72 g, 13.0 mmol) and NMP (31.3 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-6. While stirring the resulting diamine solution under water cooling, CA-2 (2.37 g, 12.1 mmol) and NMP (13.4 g) were added. The mixture was stirred at room temperature for 18 hours to obtain a 12% by mass solution of polyamic acid (A-12) (viscosity: 229 mPa·s). The polyamic acid had a Mn of 10,585 and a Mw of 27,581.

[0231] <Synthesis Example 13>

[0232] DA-7 (2.46 g, 6.40 mmol) and NMP (18.0 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-7. While stirring the resulting diamine solution under water cooling, CA-2 (1.23 g, 6.26 mmol) and NMP (8.40 g) were added. The mixture was stirred at room temperature for 18 hours to obtain a 12% by mass solution of polyamic acid (A-13) (viscosity: 292 mPa·s). The polyamic acid had a Mn of 16,511 and a Mw of 60,289.

[0233] <Synthesis Example 14>

[0234] DA-5 (2.07 g, 8.01 mmol) and NMP (18.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-5. While stirring the resulting diamine solution under water cooling, CA-1 (1.65 g, 7.56 mmol) and NMP (14.8 g) were added. The mixture was stirred at 50 °C for 18 hours to obtain a 10% by mass solution of polyamic acid (A-14) (viscosity: 115 mPa·s). The polyamic acid had a Mn of 12,045 and a Mw of 27,326.

[0235] <Synthesis Example 15>

[0236] DA-6 (3.72 g, 13.0 mmol) and NMP (37.3 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-6. While stirring the resulting diamine solution under water cooling, CA-1 (2.64 g, 12.1 mmol) and NMP (9.30 g) were added. The mixture was stirred at 50 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-15) (viscosity: 278 mPa·s). The polyamic acid had a Mn of 10,832 and a Mw of 43,395.

[0237] <Synthesis Example 16>

[0238] DA-7 (3.08 g, 8.00 mmol) and NMP (22.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-7. While stirring the resulting diamine solution under water cooling, CA-1 (1.61 g, 7.36 mmol) and NMP (11.8 g) were added. The mixture was stirred at 50 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-16) (viscosity: 256 mPa·s). The polyamic acid had a Mn of 10,700 and a Mw of 37,763.

[0239] <Synthesis Example 17>

[0240] DA-6 (2.29 g, 8.00 mmol) and NMP (16.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-6. While stirring the resulting diamine solution under water cooling, CA-3 (1.69 g, 7.52 mmol) and NMP (12.4 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-17) (viscosity: 240 mPa·s). The polyamic acid had a Mn of 11,482 and a Mw of 38,490.

[0241] <Synthesis Example 18>

[0242] DA-7 (2.69 g, 7.00 mmol) and NMP (19.7 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-7. While stirring the resulting diamine solution under water cooling, CA-3 (1.54 g, 6.86 mmol) and NMP (10.1 g) were added. The mixture was stirred at 40 °C for 18 hours to obtain a 12% by mass solution of polyamic acid (A-18) (viscosity: 283 mPa·s). The polyamic acid had a Mn of 13,087 and a Mw of 45,255.

[0243] <Synthesis Example 19>

[0244] DA-8 (1.28 g, 6.42 mmol), DA-10 (0.32 g, 1.61 mmol), and NMP (14.3 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-8. While stirring the resulting diamine solution under water cooling, CA-2 (1.49 g, 7.60 mmol) and NMP (13.3 g) were added. The mixture was stirred at room temperature for 18 hours to obtain a 10% by mass solution of polyamic acid (A-19) (viscosity: 125 mPa·s). The polyamic acid had a Mn of 11,120 and a Mw of 41,992.

[0245] <Synthesis example 20>

[0246] DA-8 (2.99 g, 15.0 mmol), DA-9 (2.11 g, 5.01 mmol), DA-10 (0.99 g, 4.99 mmol), and NMP (44.6 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the substances. While stirring the resulting diamine solution under water cooling, CA-2 (4.51 g, 23.0 mmol) and NMP (15.4 g) were added. The mixture was stirred at room temperature for 18 hours to obtain a 15% by mass solution of polyamic acid (A-20) (viscosity: 592 mPa·s). The polyamic acid had a Mn of 12,080 and a Mw of 32,115.

[0247] <Synthesis Example 21>

[0248] DA-8 (5.42 g, 27.2 mmol), DA-10 (1.35 g, 6.80 mmol), and NMP (64.5 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-8. While stirring the resulting diamine solution under water cooling, CA-2 (1.53 g, 7.82 mmol) and NMP (10.2 g) were added, and the mixture was stirred at room temperature for 0.5 hours. Subsequently, while stirring the solution under water cooling, CA-4 (6.38 g, 25.5 mmol) and NMP (8.50 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-21) (viscosity: 1,250 mPa·s). The polyamic acid had a Mn of 15,100 and a Mw of 54,900.

[0249] <Synthesis example 22>

[0250] DA-4 (0.98 g, 4.00 mmol), DA-8 (0.78 g, 4.00 mmol), and NMP (10.1 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-4. While stirring the resulting diamine solution under water cooling, CA-4 (1.50 g, 6.00 mmol) and NMP (8.50 g) were added, and the mixture was stirred at 50 °C for 2 hours. Subsequently, while stirring the solution under water cooling, CA-5 (0.49 g, 1.68 mmol) and NMP (2.80 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-22) (viscosity: 315 mPa·s). The polyamic acid had a Mn of 9,491 and a Mw of 26,134.

[0251] <Synthesis example 23>

[0252] DA-4 (2.81 g, 11.5 mmol), DA-8 (2.29 g, 11.5 mmol), and NMP (45.9 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-4. While stirring the resulting diamine solution under water cooling, CA-4 (2.88 g, 11.5 mmol) and NMP (15.4 g) were added, and the mixture was stirred at 50 °C for 2 hours. Subsequently, while stirring the solution under water cooling, CA-5 (2.86 g, 9.72 mmol) and NMP (2.8 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-23) (viscosity: 298 mPa·s). The polyamic acid had a Mn of 8,290 and a Mw of 22,181.

[0253] <Synthesis example 24>

[0254] DA-4 (2.81 g, 11.5 mmol), DA-8 (2.29 g, 11.5 mmol), and NMP (45.9 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-4. While stirring the resulting diamine solution under water cooling, CA-6 (2.58 g, 11.5 mmol) and NMP (10.4 g) were added, and the mixture was stirred at room temperature for 2 hours. Subsequently, while stirring the solution under water cooling, CA-5 (2.87 g, 9.72 mmol) and NMP (3.3 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-24) (viscosity: 300 mPa·s). The polyamic acid had a Mn of 9,018 and a Mw of 27,228.

[0255] <Synthesis example 25>

[0256] DA-8 (4.14 g, 20.8 mmol), DA-10 (1.03 g, 5.19 mmol), and NMP (46.6 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-8. While stirring the resulting diamine solution under water cooling, CA-2 (2.20 g, 11.4 mmol) and NMP (7.50 g) were added, and the mixture was stirred at room temperature for 0.5 hours. Subsequently, while stirring the solution under water cooling, CA-4 (3.25 g, 13.0 mmol) and NMP (6.20 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-25) (viscosity: 535 mPa·s). The polyamic acid had a Mn of 10,218 and a Mw of 29,128.

[0257] <Synthesis example 26>

[0258] DA-8 (5.42 g, 27.2 mmol), DA-10 (1.35 g, 6.80 mmol), and NMP (64.5 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while supplying nitrogen to dissolve the DA-8. While stirring the resulting diamine solution under water cooling, CA-2 (1.48 g, 7.55 mmol) and NMP (10.2 g) were added, and the mixture was stirred at room temperature for 0.5 hours. Subsequently, while stirring the solution under water cooling, CA-4 (6.38 g, 25.5 mmol) and NMP (8.50 g) were added, and the mixture was stirred at 50 °C for 18 hours to obtain a 15% by mass solution of polyamic acid (A-26) (viscosity: 530 mPa·s). The polyamic acid had a Mn of 9,982 and a Mw of 28,927.

[0259] The types and amounts of tetracarboxylic acid components and diamine components used in the above synthetic examples 1 to 26 are shown in Table 1.

[0260] [Table 1]

[0261]

[0262] [Preparation of Liquid Crystal Alignment Agent]

[0263] <Example 1>

[0264] NMP (0.17 g), GBL (5.53 g), BCS (1.80 g), and BCA (0.60 g) were added to a solution (3.90 g) of polyamic acid (A-2) obtained in Synthesis Example 2, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-1) with a polymer solid component to each solvent mass ratio (polymer solid component: NMP: GBL: BCS: BCA) of 4:30:46:15:5.

[0265] <Examples 2-6 and Comparative Examples 1-6>

[0266] The polyamic acid solution used was changed as shown in Table 2. Otherwise, the same procedure as in Example 1 was followed, thereby obtaining liquid crystal alignment agents AL-2 to AL-6 as Examples 2 to 6 and liquid crystal alignment agents AL-C1 to AL-C6 as Comparative Examples 1 to 6.

[0267] <Example 7>

[0268] In the polyamic acid (A-3) solution (0.90 g) obtained in Synthesis Example 3, a polyamic acid (A-21) solution (2.88 g), NMP (4.68 g), BCS (3.00 g), and AD-1 (1% NMP solution, 0.54 g) obtained in Synthesis Example 21 were added. The mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-7) with a polymer mass ratio ((A-3):(A-15)) of 20:80, a polymer solid component to each solvent mass ratio (polymer solid component: NMP: BCS) of 4.5:70.5:25, and an AD-1 mixing ratio of 1 part by mass to 100 parts by mass of polymer.

[0269] <Examples 8-18 and Comparative Examples 7-10>

[0270] The types and amounts of polyamic acid solution, solvent, and additives used were changed as shown in Table 2. Otherwise, the operation was the same as in Example 7 above, thereby obtaining liquid crystal alignment agents AL-8 to AL-18 as Examples 8 to 18 and liquid crystal alignment agents AL-C7 to AL-C10 as Comparative Examples 7 to 10.

[0271] [Table 2]

[0272]

[0273] In Table 2, the values ​​in parentheses represent the proportions (parts by mass) of each polymer and additive relative to a total of 100 parts by mass of the polymer components.

[0274] [Fabrication of Liquid Crystal Cells]

[0275] <Fabrication of FFS-driven liquid crystal cells for negative liquid crystals>

[0276] A negative liquid crystal cell for manufacturing a liquid crystal display element with an FFS mode liquid crystal display element.

[0277] First, a substrate with electrodes is prepared. A 30mm x 35mm glass substrate with a thickness of 0.7mm is used. An ITO electrode with a solid pattern, constituting the counter electrode, is formed on the substrate as the first layer. A SiN (silicon nitride) film is formed on the counter electrode of the first layer using CVD (chemical vapor deposition) as the second layer. The SiN film of the second layer has a thickness of 300nm and functions as an interlayer insulating film. A comb-shaped pixel electrode, formed by patterning the ITO film, is disposed on the SiN film of the second layer as the third layer, forming two types of pixels: the first pixel and the second pixel. Each pixel is approximately 10mm in length and 5mm in width. At this point, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the SiN film of the second layer.

[0278] The pixel electrode of the third layer has a comb-like shape formed by multiple electrode elements with a width of 3μm that are bent at an inner angle of 160° in the central part and arranged in parallel with a 6μm interval. Each pixel has a first region and a second region as the boundary of the line connecting the bent portions of the multiple electrode elements.

[0279] When comparing the first and second regions of each pixel, the forming directions of the electrode elements constituting their pixel electrodes are different. That is, taking the line connecting the curved portions of multiple pixel electrode elements as a reference, the electrode elements of the pixel electrodes in the first region of the pixel are formed at an angle of 80° clockwise, and the electrode elements of the pixel electrodes in the second region of the pixel are formed at an angle of 80° counterclockwise. In other words, in the first and second regions of each pixel, the directions of the rotation (in-plane transition) of the liquid crystal in the substrate surface caused by the voltage applied between the pixel electrode and the counter electrode are opposite to each other.

[0280] Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm and then coated onto the surface of the prepared electrode substrate using a spin coating method. After drying on a hot plate at 80°C for 2 minutes, it was fired in an infrared furnace at 230°C for 20 minutes to obtain a polyimide film with a thickness of 60 nm. The polyimide film was then subjected to friction alignment treatment using synthetic fiber cloth (HY-5318 manufactured by Hyperflex) (roller diameter: 120 mm, roller speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.4 mm, friction direction: 180° relative to the line connecting the multiple pixel electrode elements of the third layer). After cleaning, it was subjected to ultrasonic irradiation in pure water for 1 minute, and water droplets were removed by blowing air. Subsequently, it was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. As opposing substrates, a glass substrate with columnar spacers of 4 μm height and ITO electrodes formed on its back side was processed in the same manner as described above to obtain a substrate with a liquid crystal alignment film that had undergone alignment treatment. The two substrates with liquid crystal alignment films were grouped together. A sealant (Mitsui Chemicals XN-1500T) was printed on one substrate with a liquid crystal injection port. The other substrate was then attached with the liquid crystal alignment film surfaces facing each other and the rubbing directions parallel and opposite. Subsequently, a heat treatment at 150°C for 60 minutes was performed to cure the sealant, creating empty cells with a cell gap of 4 μm. Negative liquid crystal MLC-7026-100 (Merck) was injected into the empty cells using a reduced-pressure injection method, and the injection port was sealed to obtain a liquid crystal cell of the FFS type for negative liquid crystal. The obtained liquid crystal cell was then heated at 120°C for 1 hour and placed at 23°C for one night before evaluation.

[0281] <Fabrication of FFS-driven liquid crystal cells for positive liquid crystals>

[0282] A positive liquid crystal cell for manufacturing a liquid crystal display element with an FFS mode liquid crystal display element.

[0283] The substrate with electrodes is the same substrate with electrodes used in the FFS-driven liquid crystal cell for negative liquid crystal described above.

[0284] The rubbing direction of the electrode substrate was changed to a 90° direction relative to the line connecting the multiple pixel electrode elements of the third layer, and the liquid crystal injected by the depressurization injection method was changed to a positive liquid crystal MLC-3019 (manufactured by Merck). Otherwise, the process was carried out in the same manner as the fabrication method for a negative liquid crystal driven FFS liquid crystal cell, thereby obtaining a positive liquid crystal cell using the FFS method. The obtained liquid crystal cell was then heated at 120°C for 1 hour and placed at 23°C overnight for evaluation.

[0285] Fabrication of negative liquid crystal cells for evaluating pretilt angle and voltage retention rate.

[0286] First, prepare a substrate with electrodes. The substrate is a glass substrate with a size of 30mm × 40mm and a thickness of 0.7mm. Form an ITO electrode with a film thickness of 35nm on the substrate. The electrode uses a striped pattern with a vertical spacing of 40mm and a horizontal spacing of 10mm.

[0287] Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm and then coated onto the prepared electrode substrate using a spin coating method. After drying on a hot plate at 80°C for 2 minutes, it was fired in an infrared heating furnace at 230°C for 20 minutes to form a coating film with a thickness of 60 nm, thus obtaining a substrate with a liquid crystal alignment film. The liquid crystal alignment film was then subjected to friction alignment treatment using synthetic fiber cloth (HY-5318 manufactured by Hyperflex) (roller diameter: 120 mm, roller speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.4 mm), followed by ultrasonic irradiation in pure water for 1 minute for cleaning. After removing water droplets by blowing air, it was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with liquid crystal alignment films were prepared. Spherical spacers with a particle size of 4 μm were dispersed on the surface of one substrate's liquid crystal alignment film. A sealant (Mitsui Chemicals XN-1500T) was printed around the liquid crystal injection port, leaving an opening. The other substrate was then attached with the friction directions opposite and the film surfaces facing each other. Subsequently, a heat treatment at 150°C for 60 minutes was performed to cure the sealant, creating an empty cell. Negative liquid crystal MLC-7026-100 (Merck) was injected into the empty cell using a reduced-pressure injection method, and the injection port was sealed to obtain the liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and placed at 23°C overnight before evaluation.

[0288] Fabrication of positive liquid crystal cells for evaluating pretilt angle and voltage retention rate.

[0289] The electrode substrate used is the same electrode substrate used for the negative liquid crystal cell used for evaluating pretilt angle and voltage retention rate. The liquid crystal injected via depressurization injection was changed to a positive liquid crystal MLC-3019 (manufactured by Merck). Otherwise, the process was the same as for the negative liquid crystal cell used for evaluating pretilt angle and voltage retention rate, thus obtaining a positive liquid crystal cell. The obtained liquid crystal cell was then heated at 120°C for 1 hour and placed at 23°C overnight before evaluation.

[0290] [Characteristics Evaluation of Liquid Crystal Cells]

[0291] The characteristics of the aforementioned FFS-driven liquid crystal cell and the liquid crystal cell used for evaluating pretilt angle and voltage retention rate are evaluated below.

[0292] Evaluation of Voltage Hold-up Rate After Backlight Endurance Test

[0293] The voltage retention rate was evaluated using a liquid crystal cell with a surface temperature of 50°C and a high-brightness backlight (light source: LED, brightness: 30000 cd / m²). 2 The liquid crystal cell was placed under irradiation for 96 hours. Then, a voltage of 1V was applied to the liquid crystal cell at 60°C for 60μsec, and the voltage was measured after 167ms. The voltage retention rate was calculated as the percentage of voltage that could be retained. A higher voltage retention rate is better. Specifically, when using a liquid crystal cell for negative liquid crystals, a voltage retention rate of 54% or higher is rated as "○", and less than 54% is rated as "×". When using a liquid crystal cell for positive liquid crystals, a voltage retention rate of 85% or higher is rated as "○", and less than 85% is rated as "×". It should be noted that it is known that if the voltage retention rate, one of the electrical characteristics of a liquid crystal display element, increases, line retention, one of the display defects of a liquid crystal display element, becomes less likely to occur.

[0294] <Afterimage Evaluation Based on Long-Term Communication>

[0295] Using the FFS-driven liquid crystal unit fabricated above, a high-brightness backlight (light source: LED, brightness: 30000 cd / m²) was applied. 2 Under irradiation, an AC voltage of ±5.5V was applied at a frequency of 30Hz for 96 hours. Afterward, a state was formed in which the pixel electrode and counter electrode of the FFS-driven liquid crystal cell were short-circuited, and the cell was placed directly at room temperature for one day.

[0296] After placement, an FFS-driven liquid crystal unit is positioned between two polarizing plates orthogonally aligned with their polarization axes. The backlight is pre-lit without applied voltage, and the arrangement angle of the FFS-driven liquid crystal unit is adjusted to minimize the brightness of the transmitted light. Then, the rotation angle Δ is calculated to determine how long the liquid crystal unit rotates from the darkest angle of the second region of the first pixel to the darkest angle of the first region of the first pixel. The same angle Δ is calculated for the second pixel by comparing the second region with the first region.

[0297] When the angle Δ is below 0.1°, it is defined as having excellent image retention characteristics, i.e., “○”, and when it is greater than 0.1°, it is defined as “×” for evaluation.

[0298] <Evaluation of viewpoint characteristics>

[0299] The pretilt angle within the liquid crystal cell used for pretilt angle evaluation was measured using the AxoScan Mueller matrix polarimeter manufactured by Optometrics. A lower pretilt angle value indicates better viewing angle characteristics. Specifically, a pretilt angle below 1.7° is rated as "○", and a pretilt angle above 1.7° is rated as "×".

[0300] Table 3 shows the evaluation results of voltage retention rate, image retention evaluation, and viewing angle characteristics of negative liquid crystal cells using the liquid crystal alignment agents of Examples 1 to 15 and Comparative Examples 1 to 9.

[0301] [Table 3]

[0302]

[0303] As shown in Table 3, for liquid crystal display elements using liquid crystal alignment films of Examples 1 to 15 obtained by using liquid crystal alignment agents containing specific diamines DA-1 to DA-3, voltage retention rate, image retention characteristics and viewing angle characteristics are all good.

[0304] Table 4 shows the evaluation results of voltage retention rate, image retention evaluation, and viewing angle characteristics of the positive liquid crystal cells using the liquid crystal alignment agents of Examples 16-18 and Comparative Examples 9 and 10.

[0305] [Table 4]

[0306]

[0307] As shown in Table 4, for liquid crystal display elements using liquid crystal alignment films of Examples 16 to 18 obtained by using liquid crystal alignment agents containing specific diamines DA-1 to DA-3, the voltage retention rate, image retention characteristics and viewing angle characteristics are all good.

[0308] Industrial availability

[0309] The liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention is widely used in liquid crystal display elements of various operating modes. For example, it can also be used as a liquid crystal alignment film for phase difference films, a liquid crystal alignment film for scanning antennas, a liquid crystal array antenna, or as a liquid crystal alignment film for transmission and scattering type liquid crystal dimming elements.

[0310] The liquid crystal display element of the present invention can be effectively applied to devices with various functions, such as LCD TVs, clocks, portable games, word processors, laptops, in-vehicle navigation systems, portable cameras, PDAs, digital cameras, mobile phones, smartphones, various monitors, information displays, etc.

[0311] Explanation of reference numerals in the attached figures

[0312] 1: Lateral electric field liquid crystal display element; 2: Comb electrode substrate; 2a, 4b, 2d: Substrate; 2b, 2g: Linear electrode; 2c, 2h, 4a: Liquid crystal alignment film; 2e: Surface electrode; 2f: Insulating film; 3: Liquid crystal; 4: Opposite substrate; L: Electric field line

[0313] It should be noted that the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-067838, filed on April 13, 2021, are incorporated herein as a disclosure of the present invention.

Claims

1. A liquid crystal alignment agent, characterized in that, The polymer contains at least one repeating unit selected from the group consisting of a repeating unit (p1) shown in formula (1) and an imidized structural unit of the repeating unit (p1). In formula (1), X1 represents a tetravalent organic group, and Y1 is a divalent organic group represented by "-Ar1-OWO-Ar2-". Ar1 and Ar2 each independently represent any divalent aromatic group in a divalent benzene ring or biphenyl structure, wherein any hydrogen atom of the aromatic group is optionally replaced by a monovalent group. W stands for *-(CH2) m -LA-* indicates a divalent organic group with 4 to 20 carbon atoms, * represents a linking bond, *-(CH2) m In -LA-*, L represents -OC (=O)- or -C (=O)-O-, and A represents -(CH2). n -, When m is an integer from 1 to 6 and n is an integer from 1 to 16, and n is 2 or more, any -CH2- constituting A may be arbitrarily replaced by -O-, -C(=O)-, -NH-, -OC(=O)-, -C(=O)-O-, -C=C-, phenylene, or cyclohexylene. Furthermore, a portion of the hydrogen atoms in W may be optionally replaced by halogen atoms, methyl groups, trifluoromethyl groups, or hydroxyl groups. R and Z each independently represent a hydrogen atom or a monovalent organic group.

2. The liquid crystal alignment agent according to claim 1, wherein, The polymer is selected to contain the following formula (D) A The group consisting of at least one polymer (P) of the diamine (0) shown in the figure, which is a polyimide precursor obtained from the diamine component of the diamine (0) and a polyimide of the imide derivative of the polyimide precursor. Ar1, Ar2 and W are as defined in claim 1.

3. The liquid crystal alignment agent according to claim 2, wherein, The formula (D) A In this context, W stands for *-(CH2). p -OC (=O)- (CH2) q -*、*-(CH2) p -OC (=O)- (CH2) q -C(=O)-O-(CH2) r -*、*-(CH2) p -C(=O)-O-(CH2) q -OC (=O)- (CH2) r -*、*-(CH2) p -OC(=O)-QC(=O)-O-(CH2) q -*, or *- (CH2) p -C(=O)-OQOC(=O)-(CH2) q -*, Q represents phenylene or cyclohexylene, and p, q, and r are each independent integers from 1 to 6.

4. The liquid crystal alignment agent according to claim 2 or 3, wherein, The diamine (0) is selected from the following formula (d A -1)~(d A Any diamine in the group consisting of -5), The formula (d) A -1)~(d A In (-5), the hydrogen atoms on the benzene ring are optionally replaced by monovalent substituents.

5. The liquid crystal alignment agent according to any one of claims 2 to 4, wherein, The polymer (P) is obtained by polycondensation reaction of the diamine component and the tetracarboxylic acid component, wherein the tetracarboxylic acid component contains acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, or derivatives thereof.

6. The liquid crystal alignment agent according to any one of claims 2 to 5, wherein, The amount of diamine (0) used relative to the diamine component is 5 mol% or more.

7. The liquid crystal alignment agent according to any one of claims 2 to 6, further comprising at least one polymer (B) selected from the group consisting of a polyimide precursor obtained using a diamine component that does not contain the diamine (0) and a polyimide of an imide derivative of the polyimide precursor.

8. The liquid crystal alignment agent according to any one of claims 2 to 7, further comprising an additive component selected from: crosslinking compounds, functional silane compounds, metal chelates, curing accelerators, surfactants, antioxidants, sensitizers, preservatives, and compounds for adjusting the dielectric constant and / or resistance of the obtained liquid crystal alignment film, wherein the crosslinking compound is selected from at least one crosslinking compound having at least one substituent selected from ethylene oxide, oxadiazonyl, terminal isocyanate, oxazoline, cyclic carbonate, hydroxyl, and alkoxy, and crosslinking compounds having polymerizable unsaturated groups.

9. A liquid crystal alignment film obtained from any one of claims 1 to 8.

10. A liquid crystal display element comprising the liquid crystal alignment film of claim 9.

11. The liquid crystal display element according to claim 10, wherein it is a lateral electric field liquid crystal display element.

12. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3). Step (1): The step of coating the liquid crystal alignment agent according to any one of claims 1 to 8 onto the substrate; Step (2): The process of firing the coated liquid crystal alignment agent to obtain a film; Step (3): The step of oriented treatment of the film obtained in step (2).

Images