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

Abstract

This invention provides a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. The liquid crystal alignment agent achieves a small non-uniformity in the twist angle of the liquid crystal, suppresses AC image retention, and is less prone to substrate peeling. A liquid crystal alignment agent contains the following components (A) and (B). Component (A): a polyamic acid ester (A) having a structural unit (a-1Ta) of formula (1Ta) and two or more structural units (a-1Da) of formula (1Da); component (B): a polyamic acid (B) having a structural unit (b-1Tb) of formula (1Tb) and a structural unit (b-1Db) of formula (1Db). (R) 11 ~R 14 R represents hydrogen atoms, alkyl groups with 1 to 6 carbon atoms, etc. 11 ~R 14 At least one of them represents a group other than a hydrogen atom. Both R1s represent hydrogen atoms or tertiary alkyl groups, at least one of which represents a tertiary alkyl group. Y1 is a divalent organic group as shown in the following formula (H1). Z represents a hydrogen atom, etc. )(Ar1, Ar 1’ Indicates a benzene ring, etc. A represents a divalent organic group with 1 to 10 carbon atoms having an alkylene structure. L1, L 1’ Indicates single bonds, etc. )(X b Y represents a tetravalent organic group. b (This indicates a divalent organic group; Z represents a hydrogen atom, etc.)

Description

Technical Field

[0001] This invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. The liquid crystal alignment agent can achieve a small non-uniformity of the twist angle of the liquid crystal, suppress AC image retention, and is less prone to substrate peeling. Background Technology

[0002] Liquid crystal display (LCD) devices are widely used in applications ranging from small devices such as mobile phones and smartphones to larger applications such as televisions and monitors. An LCD device typically includes: a liquid crystal layer sandwiched between a component substrate and a color filter substrate; pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer; an alignment film that controls the orientation of the liquid crystal molecules in the liquid crystal layer; a thin-film transistor (TFT) that switches the electrical signals supplied to the pixel electrodes; and so on. Known driving methods for liquid crystal molecules include vertical electric field methods such as TN (Twisted Nematic) and VA (Vertical Alignment); and lateral electric field methods such as IPS (In-Plane Switching) and FFS (Fringe Field Switching).

[0003] Currently, the most widely used liquid crystal alignment film in industry is manufactured by rubbing the surface of a film formed on an electrode substrate, consisting of polyamic acid and / or polyimide formed by imidizing it, in one direction using a cloth such as cotton, nylon, or polyester—a process known as rubbing treatment. Rubbing treatment is a simple and efficient method. However, with the increasing performance, resolution, and size of liquid crystal display elements, various problems arising from rubbing treatment, such as surface damage, dust generation, mechanical stress, static electricity, and inhomogeneities within the alignment surface, have become apparent. As an alternative to rubbing treatment, photoalignment methods, which impart alignment capabilities to liquid crystals by irradiating them with polarized radiation, are known. Regarding photoalignment methods, methods utilizing photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions have been proposed (see, for example, Non-Patent Literature 1, Patent Literature 1, and Patent Literature 2).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 9-297313

[0007] Patent Document 2: Japanese Patent Application Publication No. 2004-206091

[0008] Non-patent literature

[0009] Non-patent literature 1: "Liquid Crystal Optical Alignment Film", Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In liquid crystal alignment films used in IPS and FFS driving liquid crystal display elements, a high alignment constraint force is required to suppress image retention (hereinafter also referred to as AC image retention) caused by long-term AC driving. Furthermore, when using photo-alignment methods for alignment processing, the amount of light irradiation is a factor affecting energy consumption and production speed; therefore, alignment processing with a low amount of light irradiation is preferred. On the other hand, with the increasing size of liquid crystal display elements, a defect arises where the twist angle of the liquid crystal within the liquid crystal display element plane is slightly uneven due to unevenness in the manufacturing process. This unevenness results in uneven brightness within the plane when black is displayed in the liquid crystal display element, leading to a decrease in the quality of the liquid crystal display element.

[0012] Furthermore, in recent years, touch-panel liquid crystal display (LCD) devices have required high durability against external pressure from touch-sensitive devices such as fingers and pens. This means that even under external pressure, they should not easily develop alignment defects or bright spots. In addition, in flat-panel and mobile devices, the trend towards lightweighting and thinning leads to panel deformation during the panel assembly process in LCD manufacturing, thus applying stress to the panel's internal structure. This panel deformation and stress can cause the liquid crystal alignment film to peel off from the substrate, resulting in bright spots and alignment defects. Therefore, liquid crystal alignment films require high film strength to prevent substrate peeling.

[0013] Therefore, the object of the present invention is to provide a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film. The liquid crystal alignment agent can produce a liquid crystal alignment film with small non-uniformity of the twist angle of the liquid crystal within the liquid crystal alignment film surface, and can suppress AC image retention. Furthermore, it can produce a liquid crystal alignment film that is not easily peeled off from the substrate during the manufacturing of a liquid crystal display device.

[0014] Solution for solving the problem

[0015] The inventors conducted in-depth research and found that by using a liquid crystal alignment agent containing specific components, the above-mentioned problems could be solved, thus completing the present invention.

[0016] Specifically, the present invention includes the following solutions.

[0017] A liquid crystal alignment agent, characterized in that it contains the following components (A) and (B).

[0018] (A) Composition: A polyamic acid ester (A) having a structural unit (a-1Ta) as a structural unit derived from a tetracarboxylic acid derivative, and having two or more structural units (a-1Da) as structural units derived from a diamine.

[0019] (B) Composition: Polyamic acid (B) having a structural unit (b-1Tb) as a structural unit derived from a tetracarboxylic acid derivative, and a structural unit (b-1Db) as a structural unit derived from a diamine.

[0020]

[0021] (In formula (1Ta), R) 11 ~R 14 Each can independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, a monovalent organic group containing a fluorine atom with 1 to 6 carbon atoms, or a phenyl group, R 11 ~R 14 At least one of them represents a group other than a hydrogen atom as defined above. Each of the two R1s independently represents a hydrogen atom or a tertiary alkyl group, wherein at least one of them represents a tertiary alkyl group.

[0022] In formula (1Da), Y1 is a divalent organic group as shown in formula (H1) below. Z each independently represents a hydrogen atom or a monovalent organic group.

[0023] *-Ar1-L1-AL 1′ -Ar 1′ -* (H1)

[0024] (In formula (H1), Ar1, Ar 1’ Each can independently represent a benzene ring, biphenyl structure, or naphthalene ring. Ar1, Ar 1’ Any hydrogen atom on the ring may be optionally replaced by a monovalent group. A represents a divalent organic group with 1 to 10 carbon atoms having an alkylene structure. L1, L 1’ Each of these symbols independently represents a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -C(=O)-NR- (where R represents a hydrogen atom or a monovalent organic group) or -NR-C(=O)- (where R represents a hydrogen atom or a monovalent organic group). * indicates a bonded bond.

[0025]

[0026] (In formula (1Tb), X)b Representing a tetravalent organic group, in formula (1Db), Y b (The radical "Z" represents a divalent organic group, while "Z" independently represents either a hydrogen atom or a monovalent organic group.)

[0027] It should be noted that, throughout this specification, the following terms and abbreviations have the following meanings: Halogen atoms are fluorine, chlorine, bromine, iodine, etc. "tert-" representing tertiary is also represented as "t-". The Boc group represents a tert-butoxycarbonyl group. * indicates a bond.

[0028] Invention Effects

[0029] According to the present invention, even with a small amount of light irradiation, the following liquid crystal alignment agent, the following liquid crystal alignment film, and the liquid crystal display element using the liquid crystal alignment film can be obtained. The liquid crystal alignment agent can produce a liquid crystal alignment film with small non-uniformity of the twist angle of the liquid crystal within the liquid crystal alignment film surface, and can suppress AC image retention. Furthermore, a liquid crystal alignment film that is not easily peeled off from the substrate during the manufacture of a liquid crystal display device can be obtained.

[0030] The mechanism by which the above-mentioned effects are obtained through this invention may not be clear, but the following can be considered as one of the reasons. The liquid crystal alignment agent of this invention contains specific polyamic acid ester (A) and polyamic acid (B) as polymer components. Polyamic acid ester (A) has a highly hydrophobic tertiary alkyl ester structure, thus it can suppress the formation of hydrogen bonds with polyamic acid (B), and the transferability of components to the air interface is increased when forming a liquid crystal alignment film, and the bias of polyamic acid ester in the liquid crystal interface is increased. In addition, the tertiary alkyl ester of polyamic acid ester (A), which has a large volume structure, is easy to detach when the coated film is fired. Therefore, thermal imidization is easier to perform than that of the usual methyl ester structure, and tertiary alkyl ester is less likely to remain in the obtained liquid crystal alignment film.

[0031] Therefore, high liquid crystal alignment is uniformly obtained within the plane. Thus, even with low light irradiation, the non-uniformity (torsion angle) of the liquid crystal within the liquid crystal alignment film can be minimized, and the liquid crystal alignment film can suppress AC image retention. Furthermore, it is believed that when the aforementioned polyamic acid ester (A) is calcined, for example, when R1 is tert-butyl, isobutylene detaches and is imidized via polyamic acid, thus improving the film strength of the resulting liquid crystal alignment film. Additionally, the liquid crystal alignment agent of the present invention contains polyamic acid (B), which has a highly polar structure, thus enabling the production of liquid crystal alignment films that are less prone to substrate peeling. Attached Figure Description

[0032] Figure 1 This is a schematic partial cross-sectional view showing an example of a transverse electric field liquid crystal display element of the present invention.

[0033] Figure 2 This is a schematic partial cross-sectional view showing another example of the transverse electric field liquid crystal display element of the present invention. Detailed Implementation

[0034] <Polyamic acid ester (A)>

[0035] The liquid crystal alignment agent of the present invention contains a polyamic acid ester (A) having a structural unit (a-1Ta) of the above formula (1Ta) as a structural unit derived from a tetracarboxylic acid derivative, and having two or more structural units (a-1Da) of the above formula (1Da) as structural units derived from a diamine. It should be noted that the polymer (A) may be composed of one or more of the above formulas.

[0036] By having two or more structural units (a-1Da) as shown in the above formula (1Da), a liquid crystal alignment film with a suitable balance of various properties such as high alignment confinement force and high photosensitivity can be obtained from polyamic acid ester (A). Therefore, a liquid crystal alignment film that can suppress AC image retention can be obtained, and the amount of light required for alignment processing can be reduced.

[0037] The polyamic acid ester (A) of the present invention may have all repeating units that are amic acid ester structures, or some of its repeating units may be amic acid ester structures. In the case where some of the repeating units are amic acid ester structures, the remaining repeating units may be amic acid structures, or structures formed by imidization of the amic acid structure. Furthermore, the remaining repeating units may be repeating units having both amic acid structures and imidized structures.

[0038] As a structural unit of polyaminate (A) representing a tetracarboxylic acid derivative, R is represented by the above formula (1Ta). 11 ~R 14 Specific examples of alkyl groups having 1 to 6 carbon atoms, preferably 1 to 4, include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, etc. 11 ~R 14 Specific examples of alkenyl groups with 2 to 6 carbon atoms, preferably 2 to 4, include vinyl, propenyl, and butenyl groups, which can be linear or branched. 11 ~R 14 Specific examples of alkynyl groups with 2 to 6 carbon atoms, preferably 2 to 4, include ethynyl, 1-propynyl, and 2-propynyl. As described above, R... 11 ~R 14The number of carbon atoms containing fluorine atoms in the fluorine group is 1 to 6, preferably 1 to 4, and examples include: fluoromethyl, trifluoromethyl, pentafluoroethyl, pentafluoropropyl, etc.

[0039] Regarding R 11 ~R 14 From the viewpoint of high photoreactivity, R is a more preferred combination. 11 ~R 14 It is a hydrogen atom or a methyl group, preferably R. 11 ~R 14 At least one of them is methyl, more preferably R 11 ~R 14 At least two of them are methyl groups. Further preferred is R. 11 and R 14 For methyl, R 12 and R 13 The case where the atom is hydrogen.

[0040] The tertiary alkyl group in R1 of the polyaminate (A) has 4 to 10 carbon atoms, preferably 4 to 7. Examples include tert-butyl, tert-pentyl, tert-hexyl, and tert-heptyl. Tert-butyl is preferred.

[0041] From the viewpoint of properly obtaining the effects of the present invention, the structural unit (a-1Ta) of the polyaminate (A) of the present invention is preferably 5 mol% or more, more preferably 25 mol% or more, and even more preferably 60 mol% or more, relative to all structural units derived from tetracarboxylic acid derivatives of the polyaminate (A).

[0042] The polyamic acid ester (A) of the present invention may also have a structural unit (a-2Ta) as shown in the following formula (2Ta) as a structural unit derived from a tetracarboxylic acid derivative.

[0043]

[0044] (Each R2 independently represents a hydrogen atom or a monovalent organic group. X) 2a This indicates a tetravalent organic group. Where, in X... 2a In the case of a tetravalent organic group as shown in formula (g) below, R2 represents a hydrogen atom.

[0045]

[0046] (R 11’ ~R 14’ Including their preferred solutions, respectively, R is related to the above equation (1Ta). 11 ~R 14 To make them have the same meaning.

[0047] As a monovalent organic group of R2 in the above formula (2Ta), examples include: a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10; wherein the methylene group of the hydrocarbon group is surrounded by -O-, -S-, -CO-, -COO-, -COS-, or -NR-. 3 —(where R) 3 (a monovalent hydrocarbon group consisting of 1 to 10 hydrogen atoms or carbon atoms) -CO-NR 3 —(where R) 3 (a monovalent hydrocarbon group consisting of 1 to 10 hydrogen atoms or carbon atoms), -Si(R) 3 )2-(where R 3 A monovalent group A formed by replacing hydrogen atoms or monovalent hydrocarbon groups with 1 to 10 carbon atoms, such as -SO2-; a monovalent group formed by replacing at least one hydrogen atom bonded to the carbon atom of the above-mentioned monovalent hydrocarbon group or the above-mentioned 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.

[0048] As the monovalent organic group of R2 in the above formula (2Ta), it is preferably an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, an alkynyl group with 2 to 10 carbon atoms, a tert-butoxycarbonyl group, or a 9-fluorenemethoxycarbonyl group, more preferably an alkyl group with 1 to 3 carbon atoms, and even more preferably a methyl group.

[0049] From the viewpoint of properly obtaining the effects of the present invention, each of the two R2s is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0050] X in the above equation (2Ta) 2a Specific examples of tetravalent organic groups, in addition to the tetravalent organic groups shown in formula (g) above, include tetravalent organic groups obtained by removing two anhydride groups from the following tetracarboxylic dianhydrides (hereinafter also collectively referred to as other tetracarboxylic dianhydrides).

[0051] Acyclic aliphatic tetracarboxylic anhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride; 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, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-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]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid dianhydride, 2,4,6,8-tetracarboxylic acid bicyclo[3.3.0]octane-2:4,6:8- Dihydrides are isocyclic tetracarboxylic dianhydrides; pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidene di(phthalic anhydride), 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride Aromatic tetracarboxylic acid dianhydrides such as 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bis(triphenylene) anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxybis(1,4-phenylene)bis(phthalic acid) dianhydride, or 4,4'-methylenebis(1,4-phenylene)bis(phthalic acid) dianhydride; and tetracarboxylic acid dianhydrides as described in Japanese Patent Application Publication No. 2010-97188.

[0052] As more preferred examples of the other tetracarboxylic dianhydrides mentioned above, the following can be listed: 1,2,3,4-butanetetracarboxylic dianhydride, 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-tricarboxylatedcyclopentylacetic 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 bicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride.

[0053] From the viewpoint of properly obtaining the effects of the present invention, X in the above formula (2Ta) 2a The tetravalent organic group is more preferably the tetravalent organic group shown in the above formula (g).

[0054] The proportion of the structural units represented by formula (2Ta) in polyaminate (A) is preferably 95 mol% or less, more preferably 75 mol% or less, and even more preferably 40 mol% or less, relative to all structural units derived from tetracarboxylic acid derivatives in polyaminate (A) per mole.

[0055] In formula (1Da), Y1 is the divalent organic group shown in formula (H1). In formula (H1), L1, L... 1’ As mentioned above. It should be noted that, as representatives of L1 and L... 1’ The monovalent organic group R in -C(=O)-NR- or -NR-C(=O)- can be exemplified as: alkyl with 1 to 3 carbon atoms, alkoxy with 1 to 3 carbon atoms, alkenyl with 2 to 3 carbon atoms, acyl with 2 to 3 carbon atoms, alkylsilyl with 1 to 3 carbon atoms, alkoxysilyl with 1 to 3 carbon atoms, or a monovalent organic group in which a portion of the hydrogen atom of these groups is replaced by at least any one of a halogen atom and a hydroxyl group.

[0056] As Ar1 and Ar in the above formula (H1) 1’The monovalent group of any hydrogen atom substituent on the ring can be exemplified by: halogen atoms; alkyl groups having 1 to 3 carbon atoms; alkyl groups having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms are replaced by halogen atoms or hydroxyl groups; alkoxy groups having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms are replaced by at least any one of the aforementioned halogen atoms and hydroxyl groups; alkenyl groups having 2 to 3 carbon atoms; acyl groups having 2 to 3 carbon atoms; alkylsilyl groups having 1 to 3 carbon atoms; alkoxysilyl groups having 1 to 3 carbon atoms; and monovalent groups such as hydroxyl and nitrile groups.

[0057] As Ar1 and Ar in the above formula (H1) 1’ Specific examples 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, 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, etc., optionally having substituted benzene rings; 4,4'-biphenylene, 2-methyl-4,4'-biphenylene, 2-ethyl-4,4'-biphenylene, 2-propyl-4,4'-biphenylene, 2-butyl-4,4'-biphenylene, etc. 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, 3-tert-butyl-4,4'-biphenylene, 3-methoxy-4,4'-biphenylene, 3-ethoxy Biphenyl structures optionally having substituents, such as methyl-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; and naphthalene rings optionally having substituents, such as 1,5-naphthylene, 2,6-naphthylene, and 1-methyl-2,6-naphthylene.

[0058] In the above formula (H1), A is a divalent organic group having an alkylene structure. When the alkylene structure has three or more carbon-carbon bonds, any carbon-carbon bond constituting the alkylene structure may optionally be replaced by a carbon-carbon double bond. A is preferably as follows (q0), (q1), (q2): an alkylene group having 1 to 10 carbon atoms (q0); a divalent organic group formed by inserting -O-, -C(=O)-, -NH-, -O-C(=O)-, or -C(=O)-O- between the carbon-carbon bonds of the alkylene group (q1); or a divalent organic group having at least one -NR-C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group) between the carbon-carbon bonds of the alkylene group (q2).

[0059] Here, as the monovalent organic group of R in the above -NR-C(=O)-NR-, examples can be listed for L1 and L representing the above formula (H1). 1’ The structure is illustrated by R in -C(=O)-NR-.

[0060] Specific examples of the preferred options (q0), (q1), and (q2) are described below.

[0061] *-(CH2) n -*.

[0062] *-(CH2) n1 -O-(CH2) n2 -*.

[0063] *-(CH2) m1 -O-C(=O)-(CH2) n’ -C(=O)-O-(CH2) m2 -*.

[0064] *-(CH2) m1 -C(=O)-O-(CH2) n’ -O-C(=O)-(CH2) m2 -*.

[0065] *-(CH2) n1 -NR-C(=O)-NR-(CH2) n2 -*.

[0066] In the above chemical formula, R represents a hydrogen atom or a monovalent organic group. Examples of such monovalent organic groups include L1 and L2 representing the above formula (H1). 1’The structure is illustrated by exemplifying R in -C(=O)-NR-. The two Rs may optionally be the same or different from each other. n is an integer from 1 to 10, more preferably an integer from 2 to 10, and even more preferably an integer from 2 to 6. m1 and m2 are each independently an integer from 0 to 4, n' is an integer from 1 to 6, and the sum of m1, m2, and n' is 1 to 8. *-(CH2) n1 -O-(CH2) n2 In the given equation, n1 and n2 are each independent integers from 1 to 6, and the sum of n1 and n2 is from 2 to 10. *-(CH2) n1 -NR-C(=O)-NR-(CH2) n2 In the given information, n1 and n2 are each an integer from 1 to 6, and the sum of n1 and n2 is from 2 to 9.

[0067] From the viewpoint of properly obtaining the effects of the present invention, *-L1-A-L 1’ *The following scheme is preferred. In the following formulas, m1, m2, n, n', n1, and n2 are defined in the same way as in the formulas above. Furthermore, in the following formulas, R in -C(=O)-NR- or -NR-C(=O)-NR- represents a hydrogen atom or a monovalent organic group. Examples of monovalent organic groups include L1 and L2 representing the above formula (H1). 1’ The structure is illustrated by R in -C(=O)-NR-.

[0068] *-(CH2) n -*、-O-(CH2) n -O-*.

[0069] *-O-(CH2) n1 -O-(CH2) n2 -O-*.

[0070] *-C(=O)-(CH2) n -C(=O)-*.

[0071] *-C(=O)-NR-(CH2) n -O-*.

[0072] *-O-C(=O)-(CH2) n -O-*.

[0073] *-O-C(=O)-(CH2) n -O-C(=O)-*.

[0074] *-O-C(=O)-(CH2) n -C(=O)-O-*.

[0075] *-(CH2)m1 -O-C(=O)-(CH2) n’ -C(=O)-O-(CH2) m2 -*.

[0076] *-S-(CH2) n -S-*.

[0077] *-C(=O)-NR-(CH2) n -NR-C(=O)-*.

[0078] *-C(=O)-O-(CH2) n -O-C(=O)-*.

[0079] *-(CH2) m1 -C(=O)-O-(CH2) n’ -O-C(=O)-(CH2) m2 -*.

[0080] *-O-(CH2) n -*、*-S-(CH2) n -*.

[0081] *-NR-C(=O)-(CH2) n -C(=O)-NR-*.

[0082] *-(CH2) n1 -NR-C(=O)-NR-(CH2) n2 -*.

[0083] Furthermore, from the viewpoint of properly obtaining the effects of the present invention, *-(CH2) is preferred. n -*、*-O-(CH2) n -O-*、*-O-(CH2) n -*.

[0084] From the viewpoint of properly obtaining the effects of the present invention, the polyamic acid ester (A) preferably contains at least one structural unit of the above formula (1Da) as a structural unit derived from a diamine, wherein Y1 is a divalent organic group having three or more benzene rings.

[0085] Here, the benzene ring in "divalent organic groups having three or more benzene rings" also includes benzene rings that form fused rings. Furthermore, when counting the number of benzene rings in the above formula (H1), the naphthalene ring is assumed to have two benzene rings, the anthracene ring is assumed to have three benzene rings, and the biphenyl structure is assumed to have two benzene rings for counting.

[0086] From the viewpoint of properly obtaining the effects of the present invention, the polyaminate (A) preferably has the structural unit shown in formula (1Da), wherein at least one of Y1 is Ar1 and Ar2. 1’ The other Y1 groups are divalent organic groups of the same structure as those shown in formula (H1), and at least one of them is Ar1 and Ar2. 1’ The divalent organic groups represented by formula (H1) have different structures.

[0087] As Ar1 and Ar 1’ Preferred combinations having the same structure include: combinations of biphenyl structures optionally having the above-described substituents and biphenyl structures optionally having the above-described substituents, and combinations of naphthalene rings optionally having the above-described substituents and naphthalene rings optionally having the above-described substituents. Furthermore, as Ar1 and Ar... 1’ Preferred combinations for different structural cases include: combinations of benzene rings optionally having the above-mentioned substituents and biphenyl structures optionally having the above-mentioned substituents; combinations of benzene rings optionally having the above-mentioned substituents and naphthalene rings optionally having the above-mentioned substituents; and combinations of biphenyl structures optionally having the above-mentioned substituents and naphthalene rings optionally having the above-mentioned substituents.

[0088] From the viewpoint of properly obtaining the effects of the present invention, Y1 in the above formula (1Da) is preferably a divalent organic group represented by any of the following formulas (h1-1) to (h1-13). In formulas (h1-1) to (h1-13), the bonding positions of the benzene ring are preferably at positions 1 and 4, and the bonding positions of the naphthalene ring are preferably at positions 2 and 6. In formula (h1-4), the total number of -CH2- is 10 or less. In formulas (h1-7) and (h1-8), the total number of -CH2- is 8 or less, and the two m are optionally the same or different from each other.

[0089]

[0090] The proportion of the structural units (a-1Da) contained in the polyamic acid ester (A) relative to all the diamine-derived structural units in the polyamic acid ester (A) is preferably 5 to 95 mol%, more preferably 10 to 95 mol%, and even more preferably 20 to 80 mol%.

[0091] As the monovalent organic group Z in the above formula (1Da), examples include: monovalent hydrocarbon groups with 1 to 6 carbon atoms; the methylene group of the hydrocarbon group is surrounded by -O-, -S-, -CO-, -COO-, -COS-, -NR-. 3 -、-CO-NR 3 -, -Si(R) 3 )2-(where R 3A monovalent group A formed by substituting hydrogen atoms or monovalent hydrocarbon groups with 1 to 6 carbon atoms, such as -SO2-; a monovalent group formed by substituting at least one hydrogen atom bonded to the carbon atom of the above-mentioned monovalent hydrocarbon group or the above-mentioned 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.; a monovalent group having a heterocyclic ring.

[0092] As the monovalent organic group Z in the above formula (1Da), it is preferably an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, or a tert-butoxycarbonyl group, more preferably an alkyl group with 1 to 3 carbon atoms, and even more preferably a methyl group.

[0093] From the viewpoint of properly obtaining the effects of the present invention, each of the two Zs in the above formula (1Da) is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0094] The polyamic acid ester (A) used in this invention may also contain structural units (a-1Da-2) derived from other diamines, other than the structural unit (a-1Da). The structural unit (a-1Da-2) may be one or more of the following:

[0095] Examples of other diamines derived from the structural unit (a-1Da-2) of other diamines mentioned above include the following substances.

[0096] Examples include: p-phenylenediamine, 2,3,5,6-tetramethylp-phenylenediamine, 2,5-dimethylp-phenylenediamine, m-phenylenediamine, 2,4-dimethylm-phenylenediamine, 1,4-diamino-2,5-methoxybenzyl, 2,5-diaminotoluene, 2,6-diaminotoluene, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3-trifluoromethyl-4,4'-diaminobiphenyl, 2-trifluoromethyl -4,4'-diaminobiphenyl, 3-fluoro-4,4'-diaminobiphenyl, 2-fluoro-4,4'-diaminobiphenyl, 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, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene and other specific diamines (hereinafter, they are also referred to as specific diamines (1)).

[0097] 1,4-Phenylidene bis(4-aminobenzoate), 1,4-Phenylidene bis(3-aminobenzoate), 1,3-Phenylidene bis(4-aminobenzoate), 1,3-Phenylidene bis(3-aminobenzoate), bis(4-aminophenyl) terephthalate, bis(3-aminophenyl) terephthalate, bis(4-aminophenyl) isophthalate, bis(3-aminophenyl) isophthalate; 4,4'-Diamino 4,4-diaminochalcone, or 4-(4,4,4-trifluorobutoxy)benzoic acid [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl] ester or 4-(4,4,4-trifluorobutoxy)benzoic acid [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-]]] Diamines with photo-oriented groups, such as aromatic diamines with cinnamic acid ester structures, represented by (4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl]ester; diamines with photopolymerizable groups at the ends, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallyl aniline; diamines with free radical polymerization initiator functions, such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylacetone and 2-(4-(2-hydroxy-2-methylpropionyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines with amide bonds, such as 4,4'-diaminobenzoylaniline; diamines with urea bonds, such as 1,3-bis(4-aminophenyl)urea; H2N-Y D -NH2(Y D This refers to diamines with thermally detachable groups, such as divalent organic groups (where D represents a protecting group that is removed and replaced by a hydrogen atom upon heating).

[0098] 3,3'-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-Diaminodiphenyl ether, 3,3'-Diaminodiphenylmethane, 3,4'-Diaminodiphenylmethane, 4,4'-Diaminodiphenylmethane, 4,4'-Sulfodiphenylamine, 3,3'-Sulfodiphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-Thiodiphenylamine, 3,3'-Thiodiphenylamine, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 2,2'-bis[4-(4-aminophenyl)benzene] [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'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 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, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-2-oxazolyl]-aniline, 1,4-bis(p-aminobenzyl)piperazine, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, 4-( 4-Aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 2,5-bis(4-aminophenyl)pyrrole, 4,4'-(1-methyl-1H-pyrrole-2,5-diyl)bis[aniline], 1,4-bis-(4-aminophenyl)piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridin-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-6-aminobenzimidazole, 5-(1H-benzimidazole-2-yl)phenyl-1,3-diamine, or the heterocyclic diamines shown in formulas (z-1) to (z-5) below;Or, diamines with a diphenylamine structure, such as 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)-N,N'-dimethyl-1,4-phenylenediamine, which have a structure containing at least one nitrogen atom selected from the group consisting of a heterocycle, secondary amino group, or tertiary amino group containing a nitrogen atom (excluding amino groups derived from -N(D)- (where D represents a protecting group that is removed and substituted with a hydrogen atom by heating). Hereinafter, these are also referred to as specific nitrogen-containing structures.

[0099] 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 Acids, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid, and other diamines with carboxyl groups; 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl) Diamines with a steroidal skeleton, such as cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl ester of 3,5-diaminobenzoate, cholesteryl ester of 3,5-diaminobenzoate, cholesteryl ester of 3,5-diaminobenzoate, and lanostane of 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulas (V-1) to (V-2); 1 Diamines containing siloxane bonds, such as 3-bis(3-aminopropyl)-tetramethyldisiloxane; acyclic aliphatic diamines such as m-phenylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine); and diamines formed by bonding two amino groups to groups represented by any of the formulas (Y-1) to (Y-167) as described in WO2018 / 117239.

[0100]

[0101] In equation (V-1), m and n are integers from 0 to 3 (where 1≤m+n≤4), j is an integer of 0 or 1, and 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 fluorine atom, an alkyl group containing fluorine atoms with 1 to 10 carbon atoms, an alkoxy group containing fluorine atoms with 1 to 10 carbon atoms, an alkyl group with 3 to 10 carbon atoms, an alkoxy group with 3 to 10 carbon atoms, or an alkoxyalkyl group with 3 to 10 carbon atoms. In formula (V-2), X 2 Representing -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-, in m, n, X 1 R 1 If two such cases exist, each independently possesses the above definition.

[0102] It should be noted that the D in the -N(D)- group of the other diamines mentioned above is preferably an organic group of the carbamate system, such as benzyloxycarbonyl, 9-fluorenyloxycarbonyl, allyloxycarbonyl, or Boc group. From the viewpoint of good efficiency in thermal release, release at relatively low temperatures, and release as a harmless gas during release, the Boc group is particularly preferred.

[0103] Preferred examples of diamines having thermally detachable groups, as exemplified by the other diamines mentioned above, are preferably selected from the diamines of the following formulas (d-1) to (d-7).

[0104]

[0105] (In formulas (d-2), (d-6), and (d-7), R represents a hydrogen atom or a Boc group.)

[0106] When the polyaminate (A) used in this invention has a structural unit (a-1Da-2), from the viewpoint of appropriately obtaining the effects of this invention, it is more preferable to contain a structural unit derived from the specific diamine (1) described above. The structural unit derived from the specific diamine (1) is preferably 5 to 95 mol% per mole of all diamine-derived structural units contained in the polyaminate (A), more preferably 5 to 90 mol%, and even more preferably 20 to 80 mol%.

[0107] Furthermore, regarding polyamic acid ester (A), as the aforementioned structural unit (a-1Da-2), from the viewpoint of improving the bilayer separability with polyamic acid (B), it may also contain structural units derived from the aforementioned diamine having thermally detachable groups. The percentage of the structural units derived from the aforementioned diamine having thermally detachable groups per mole of polyamic acid ester (A) is preferably 5 to 40 mol%, more preferably 5 to 35 mol%, and even more preferably 5 to 30 mol%.

[0108] <Polyamic Acid (B)>

[0109] The liquid crystal alignment agent of the present invention comprises both the aforementioned polyamic acid ester (A) and polyamic acid (B), wherein the polyamic acid (B) has a structural unit (b-1Tb) of formula (1Tb) as a structural unit derived from a tetracarboxylic acid derivative, and a structural unit (b-1Db) of formula (1Db) as a structural unit derived from a diamine. The polyamic acid (B) may be composed of one or more of these units. Furthermore, the aforementioned structural units constituting the polyamic acid (B) may each be composed of one or more of these units. It should be noted that the polyamic acid (B) preferably does not contain the aforementioned structural units (a-1Ta) and (a-1Da) of the polyamic acid ester (A) within the same molecule.

[0110] X, as in the above equation (1Tb) b The tetravalent organic groups in X can be exemplified by: tetravalent organic groups obtained by removing two acid dianhydride groups from acyclic aliphatic tetracarboxylic dianhydrides; tetravalent organic groups obtained by removing two acid dianhydride groups from alicyclic tetracarboxylic dianhydrides; or tetravalent organic groups obtained by removing two acid dianhydride groups from aromatic tetracarboxylic dianhydrides. Specific examples include those found in the aforementioned X... 2a The example shown is a tetravalent organic group.

[0111] It should be noted that aromatic tetracarboxylic acid dianhydrides are obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the aromatic ring.

[0112] Acyclic aliphatic tetracarboxylic dianhydrides are obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. The structure need not consist solely of a chain hydrocarbon; it can also have alicyclic or aromatic ring structures in some parts.

[0113] Alicyclic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the alicyclic structure. None of these four carboxyl groups are bonded to an aromatic ring. Furthermore, it is not necessary for the structure to consist solely of an alicyclic structure; it can also have a chain hydrocarbon structure or an aromatic ring structure in a portion thereof.

[0114] From the viewpoint of properly obtaining the effects of the present invention, the above-described X b The tetravalent organic group is preferably derived from a tetracarboxylic acid dianhydride 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. More preferably, X b Examples of tetravalent organic groups shown in formula (g) and X in formula (2Ta) can be listed. 2a The structure illustrated in the examples is further preferably a tetravalent organic group obtained by removing two acid dianhydride groups from other tetracarboxylic dianhydrides illustrated in the above-described polyamic acid ester (A). Furthermore, from the viewpoint of improving liquid crystal orientation, the above-described acyclic aliphatic or alicyclic tetracarboxylic dianhydrides are preferably tetracarboxylic dianhydrides having at least one partial structure selected from the group consisting of cyclobutane ring structures, cyclopentane ring structures, and cyclohexane ring structures.

[0115] Regarding polyamic acid (B), from the viewpoint of appropriately obtaining the effects of the present invention, the structural unit (b-1Tb) is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, relative to all structural units derived from the tetracarboxylic acid derivative contained in polyamic acid (B), wherein the structural unit (b-1Tb) is X b A tetravalent organic group is a tetravalent organic group formed by removing two anhydride groups from a noncyclic aliphatic tetracarboxylic dianhydride, a tetravalent organic group formed by removing two anhydride groups from an alicyclic tetracarboxylic dianhydride, or a tetravalent organic group formed by removing two anhydride groups from an aromatic tetracarboxylic dianhydride.

[0116] Y, as in the above equation (1Tb) b The divalent organic groups in [the product name] can be exemplified by Y1 mentioned above and divalent organic groups obtained by removing two amino groups from the other diamines exemplified in polyamic acid ester (A). Regarding polyamic acid (B), from the viewpoint of having fewer remnants originating from residual DC, Y... b Preferably, the diamine is formed by removing two amino groups from a diamine having a urea bond (for example, a diamine in which A in the above formula (H1) represents a divalent organic group (q2), and two amino groups are bonded to the divalent organic group shown in formula (H1); or diamines having a urea bond as exemplified among the other diamines mentioned above), a diamine having an amide bond, a diamine having a specific nitrogen-containing structure, a diamine having a carboxyl group, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, p-phenylenediamine, and m-phenylenediamine (these are also collectively referred to as specific divalent organic groups).

[0117] From the viewpoint of minimizing residual DC, polyamic acid (B) can contain at least 5 mol% of all diamine-derived structural units per mole of polyamic acid (B), preferably at least 10 mol%, and more preferably at least 20 mol% of the structural units (b-1Db) represented by formula (1Db), wherein Y b These are the specific divalent organic groups mentioned above.

[0118] As a monovalent organic group of Z in the above formula (1Db), the structures exemplified for Z in the above formula (1Da) can be listed.

[0119] In the liquid crystal alignment agent of the present invention, from the viewpoint of the effect of the present invention, wherein there are fewer residual images originating from residual DC, the content ratio of polyamic acid ester (A) to polyamic acid (B) can be 10 / 90 to 90 / 10, or 20 / 80 to 90 / 10, or 20 / 80 to 80 / 20 by mass ratio of [polyamic acid ester (A) / polyamic acid (B)].

[0120] <Manufacturing of polyamic acid and polyamic ester>

[0121] The polyamic acid esters such as polyamic acid ester (A) and polyamic acid esters such as polyamic acid ester (B) contained in the liquid crystal alignment agent of the present invention can be manufactured, for example, by the method described below. In this case, as a tetracarboxylic acid derivative, not only tetracarboxylic dianhydride can be used, but also tetracarboxylic acid dihalide compounds, tetracarboxylic acid dialkyl esters, tetracarboxylic acid dialkyl ester dihalides, etc., which are derivatives thereof can be used.

[0122] (Manufacturing of polyamic acid)

[0123] By reacting the tetracarboxylic dianhydride component with the diamine component, a polymer (polyamic acid) having an amic acid structure can be obtained. When the polyamic acid has the structure shown in the above formula (1Db), for example, as the diamine component, a diamine having the structure -N(Z)-Y1-N(Z)- (the definitions of Y1 and Z are the same as above) is used; furthermore, as the tetracarboxylic acid derivative component, a diamine having X... b (X b (The definition is the same as above) Tetracarboxylic acid dianhydride.

[0124] Polyamic acid ester (A) can be obtained by reacting a tetracarboxylic acid derivative component containing a tetracarboxylic acid dianhydride as shown in formula (T1) with a diamine component containing a diamine as shown in formula (D1) to obtain polyamic acid, and then by the method described later.

[0125]

[0126] (R 11~R 14 R with equation (1Ta) 11 ~R 14 The meanings are the same; Y1 and Z have the same meanings as Y1 in equation (1Ta) and Z in equation (1Da), respectively.

[0127] Regarding the ratio of tetracarboxylic dianhydride to diamine used in the manufacture of polyamic acid, the anhydride group of tetracarboxylic dianhydride is preferably 0.2 to 2 equivalents, more preferably 0.3 to 1.2 equivalents, relative to 1 equivalent of the amino group of the diamine. Similar to conventional polycondensation reactions, the closer the equivalent of the anhydride group of the tetracarboxylic dianhydride is to 1 equivalent, the larger the molecular weight of the resulting polyamic acid.

[0128] The reaction temperature in the manufacture of polyamic acid is preferably -20 to 150°C, more preferably 0 to 100°C. Furthermore, the reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

[0129] The production 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.

[0130] Specific examples of organic solvents used in the manufacture of the aforementioned polyamic acid 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. Furthermore, when the solvent used to manufacture the polyamic acid has high 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.

[0131] (Manufacturing of polyamide esters)

[0132] Polyamates can be obtained, for example, by the following known methods: [I] reacting the polyamic acid obtained by the above method with an esterifying agent; [II] reacting a tetracarboxylic acid diester with a diamine, preferably in an organic solvent, in the presence of a dehydration catalyst (e.g., 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinon halide, carbonyl imidazole, phosphorus condensing agent, etc.); [III] reacting a tetracarboxylic acid diester dihalide with a diamine, preferably in an organic solvent, in the presence of a base (e.g., tertiary amines such as pyridine and triethylamine, sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, potassium, etc., alkali metals); [IV] reacting the polyamic acid with a dehydration condensing agent (trifluoroacetic anhydride, etc.) to form an isoimide, followed by reacting an alcohol (e.g., methanol, ethanol, n-propanol, isopropanol, butanol, tert-butanol, etc., aliphatic alcohols), etc.

[0133] The tetracarboxylic acid diester used in [II] above can be obtained by ring-opening of the tetracarboxylic acid dianhydride with an alcohol or the like. The tetracarboxylic acid diester dihalide used in [III] above can be obtained by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride. When a polyamic acid ester is obtained in solution form by the above reaction, the solution can be used for preparing a liquid crystal alignment agent while maintaining this state, or it can be used for preparing a liquid crystal alignment agent after the polyamic acid ester contained in the reaction solution has been separated.

[0134] A more preferred method as described in [I] above is a method of obtaining polyamic acid esters by adding an esterifying agent to a solution of polyamic acid and stirring. As the solvent used in this reaction, the same organic solvents exemplified as those used in the manufacture of polyamic acid can be used. The reaction is carried out in an organic solvent, preferably at a reaction temperature of 0–100°C, more preferably at 0–50°C, for 0.5–48 hours. Furthermore, the esterifying agent may also be added during the preparation of the liquid crystal alignment agent described later to form a polyamic acid ester.

[0135] In the method described above [I], the esterification rate can be arbitrarily adjusted by changing the amount of esterifying agent used. Here, "esterification rate" refers to, for example, in the case of polyamic acid ester (A), the percentage of polyamic acid that has undergone esterification into an amic acid ester structure, expressed as a percentage, based on the total amic acid structure present in the polyamic acid before esterification. The esterification rate can be... 1 H-NMR is used to estimate the concentration based on the change in peak intensity of the carboxyl group. The esterification rate of the polyaminate (A) used in this invention is preferably 5–100%, more preferably 25–100%, and even more preferably 25–65%.

[0136] The amount of esterifying agent added in the method described above [I] is 0.01 to 50 molar equivalents relative to 1 molar equivalent of the amyl acid structural unit contained in the polyamic acid, more preferably 0.1 to 20 molar equivalents, and even more preferably 1 to 10 molar equivalents.

[0137] Examples of esterifying agents that yield polyamic acid esters with a tert-butyl ester structure include: tert-butyl 2,2,2-trichloroacetylimine ester, O-tert-butyl-N,N'-diisopropylisourea, and N,N-dimethylformamide ditert-butyl acetal.

[0138] <Solution viscosity / molecular weight of polyamic acid and polyamic acid ester>

[0139] The polyamic acid and polyamic ester used in this invention are preferably prepared as solutions with a concentration of 10-15% by mass, for example, solutions with a viscosity of 10-1000 mPa·s, from an operational point of view. It should be noted that the solution viscosity (mPa·s) of the polymer described above is a value measured using an E-type rotational viscometer at 25°C for a polymer solution with a concentration of 10-15% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0140] The weight-average molecular weight (Mw) of the polyamic acid and polyamic ester, as determined by gel permeation chromatography (GPC), converted from polystyrene, is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. 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 maintaining this molecular weight range, good orientation and stability of the liquid crystal display element can be ensured.

[0141] <End-capping agent>

[0142] Regarding the polyamic acid esters and polyamic acids used in this invention, during their manufacture, they can also be produced by using a suitable capping agent together with the tetracarboxylic acid derivative component and the diamine component as described above to form a capped polymer. The capped polymer has the effect of increasing the film hardness of the liquid crystal alignment film obtained from the coating and improving the adhesion properties between the sealant and the liquid crystal alignment film.

[0143] Examples of the ends of the polyamic acid ester (A) and polyamic acid (B) in this invention include: amino, carboxyl, anhydride, or groups derived from the capping agent described below. The amino, carboxyl, and anhydride groups can be obtained through conventional condensation reactions or by capping with the capping agent described below.

[0144] Examples of capping agents include: 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 diesters such as ditert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinyl chloride; and aniline. Monoamine compounds such as 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, and n-octylamine; monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-methacryloyloxyethyl isocyanate; and isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate.

[0145] The proportion of the capping agent used is preferably 0.01 to 20 moles relative to 100 moles of the total diamine components used in the manufacture of the polymer, and more preferably 0.01 to 10 moles.

[0146] <Liquid Crystal Alignment Agent>

[0147] The liquid crystal alignment agent of the present invention contains polyamic acid ester (A) and polyamic acid (B). In addition to polyamic acid ester (A) and polyamic acid (B), the liquid crystal alignment agent of the present invention may also contain other polymers.

[0148] Specific examples of such other polymers include polymers selected from the group consisting of polyimide precursors other than polyamic acid esters (A) and polyamic acid (B), polyimides, polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates.

[0149] Specific examples of the aforementioned poly(styrene-maleic anhydride) copolymers include: SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), and GSM301 (manufactured by Gifu Shellac Manufacturing). Specific examples of the aforementioned poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray). Specific examples of the aforementioned poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). Other polymers can also be used in combination of two or more.

[0150] 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 100 parts by mass of the total polymers contained in the liquid crystal alignment agent.

[0151] Liquid crystal alignment agents are used to produce liquid crystal alignment films, and from the viewpoint of forming a uniform film, they are preferably taken in the form of a coating solution. In the liquid crystal alignment agent of the present invention, a coating solution containing the aforementioned polymer component and organic solvent is preferred. In this case, the concentration of the polymer in the liquid crystal alignment agent can be appropriately varied according to the desired thickness of the coating film. From the viewpoint of forming a uniform and defect-free coating film, the concentration of the polymer in the liquid crystal alignment agent is preferably 1% by mass or more, and from the viewpoint of the storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred polymer concentration is 2 to 8% by mass.

[0152] The organic solvent contained in a liquid crystal alignment agent is not particularly limited as long as it uniformly dissolves the polymer components. Specific examples include: N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllacticamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, 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-Dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, 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 (also collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, 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.

[0153] Furthermore, the organic solvent contained in the liquid crystal alignment agent is preferably a mixed solvent that, in addition to the solvents mentioned above, also uses a solvent that improves the coatability and surface smoothness of the coating film when applying the liquid crystal alignment agent (also known as a poor solvent). The content of the poor 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 the poor solvent are appropriately selected according to the coating apparatus, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

[0154] The following describes specific examples of unsuitable solvents used, but are not limited to these.

[0155] For example, the following can be listed: diisopropyl ether, diisobutyl ether, diisobutylmethanol (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-ethoxyacetic acid butyl ester, 1-methylacetic acid pentyl ester, 2-ethylacetic acid butyl ester, 2-ethylacetic acid hexyl ester, 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, 1-(2-butoxyethoxy)-2-propanol, 2-(2 (-Butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene 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, 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.

[0156] Regarding unsuitable solvents, diisobutylmethanol, 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.

[0157] Preferred combinations of good and bad solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone and propylene glycol diacetate; N,N-dimethyllactic acid and diisobutyl ketone; N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diisobutyl ketone. Propylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether; N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether; N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate; N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether; N,N-dimethyl lactamide and ethylene glycol monobutyl ether; N,N-dimethyl lactamide and propylene glycol diacetate; N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate; N-methyl-2-pyrrolidone Diethylene glycol monomethyl ether and butyl cellosolve acetate; N,N-dimethyl lactamide and diethylene glycol diethyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone; N-methyl-2-pentanone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutylmethanol;N-Methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and propylene glycol diacetate; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and diisobutyl ketone; N-ethyl-2-pyrrolidone, γ-butyrolactone, and diisobutyl ketone; N-ethyl-2-pyrrolidone, N... N-Dimethyllactic acid and diisobutyl ketone; N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate; γ-butyrolactone, ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether; N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether; N-ethyl-2-pyrrolidone, cyclohexyl acetate, diacetone alcohol cyclohexanone and propylene glycol monomethyl ether; cyclopentanone and propylene glycol monomethyl ether; N-methyl-2-pyrrolidone, cyclohexanone and propylene glycol monomethyl ether, etc.

[0158] The liquid crystal alignment agent of the present invention may also contain components other than polymer components and organic solvents (hereinafter also referred to as additive components). Examples of additive components include: adhesion promoters for improving the adhesion between the liquid crystal alignment film and the substrate, and the adhesion between the liquid crystal alignment film and the sealant; compounds for improving the strength of the liquid crystal alignment film (hereinafter also referred to as crosslinking compounds); compounds for promoting imidization; and dielectric or conductive materials for adjusting the dielectric constant and resistance of the liquid crystal alignment film.

[0159] From the viewpoint of properly obtaining the effects of the present invention, the aforementioned crosslinking compound may be at least one compound selected from the group consisting of: compounds having at least one group selected from the group consisting of ethylene oxide, oxetane, protected isocyanate group, protected isothiocyanate group, a group containing an oxazoline ring structure, a group containing a Michaelis acid structure, a cyclic carbonate group, and a hydroxyalkyl amide bond; phenolic compounds having at least one of alkoxymethyl and hydroxymethyl; and compounds having polymerizable unsaturated groups.

[0160] Specific examples of the compounds containing ethylene oxide 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, bisphenol A type epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical), bisphenol F type epoxy resins such as EPIKOTE 807 (manufactured by Mitsubishi Chemical), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical), and YX6954BH30 (manufactured by Mitsubishi Chemical). Epoxy resins containing biphenyl backbones, such as those manufactured by Chemical Co., Ltd.; phenolic varnish-type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.); (ortho-, meta-, and para-)cresol varnish-type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.); triglycidyl isocyanurate esters such as TEPIC (manufactured by Nissan Chemical Co., Ltd.); alicyclic epoxy resins such as Celloxide 2021P (manufactured by Daicel Chemical Industry Co., Ltd.); N,N,N',N'-tetraglycidyl-m-phenylenediamine; 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane; N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; and tetra(glycidyloxymethyl)methane.

[0161] As specific examples of the compounds containing oxetane, compounds containing two or more oxetane groups described in paragraphs 0170 to 0175 of WO2011 / 132751 can be listed.

[0162] Specific examples of compounds with protected isocyanate groups include: compounds with two or more protected isocyanate groups as described in paragraphs 0046 and 0047 of Japanese Patent Application Publication No. 2014-224978, and compounds with three or more protected isocyanate groups as described in paragraphs 0119 and 0120 of WO2015 / 141598. Commercially available products, for example, preferably include CORONATE AP stable M, CORONATE 2503, 2515, 2507, 2513, 2555, MILLIONATE MS-50 (all manufactured by Tosoh Corporation), TAKENATE B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals Corporation). In addition, compounds with two or more protected isothiocyanate groups can be listed in Japanese Patent Application Publication No. 2016-200798.

[0163] Specific examples of compounds having groups containing an oxazoline ring structure include compounds containing two or more oxazoline ring structures as described in paragraph 0115 of Japanese Patent Application Publication No. 2007-286597, preferably compounds containing an oxazoline group 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.).

[0164] As specific examples of compounds having groups containing Michaelis acid structures, compounds having two or more Michaelis acid structures as described in WO2012 / 091088 can be listed.

[0165] Specific examples of the compounds having cyclic carbonate groups mentioned above include the compound described in WO2011 / 155577. Specific examples of the compounds having hydroxyalkylamide bonds mentioned above include the compounds described in paragraph 0058 of WO2015 / 072554 and Japanese Patent Application Publication No. 2016-118753; and the compounds described in Japanese Patent Application Publication No. 2016-200798, preferably N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamine, etc.

[0166] Specific examples of the phenolic compounds having at least one of alkoxyalkyl and hydroxymethyl can be listed as compounds described in WO2010 / 074269, preferably 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. Examples of compounds possessing polymerizable unsaturated bonds include: glyceryl mono(meth)acrylate, glyceryl di(meth)acrylate (a mixture of 1,2- and 1,3-type compounds), glyceryl tri(meth)acrylate, glyceryl 1,3-diglyceryl glycol 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, hexaethylene glycol mono(meth)acrylate, etc. These compounds are examples of crosslinking compounds and are not limited thereto. Examples include, for instance, components other than those disclosed in paragraphs 0105 to 55, paragraph 0116 of WO2015 / 060357. Furthermore, two or more crosslinking compounds may be combined.

[0167] Of the aforementioned crosslinking compounds, N,N,N',N'-tetraglycidyl-m-phenylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and TAKENATE are preferred. B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N, 1,3,5-tris(2-hydroxyethyl)isocyanurate, triglycidyl isocyanurate, N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamine, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane.

[0168] The content of the crosslinking compound in the liquid crystal alignment agent of the present invention is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more preferably 1 to 15 parts by mass from the viewpoint of properly obtaining the effects of the present invention.

[0169] Examples of such sealing agents 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, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropyl Silane coupling agents including methyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, tris(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. When using a silane coupling agent, from the viewpoint of exhibiting good resistance to AC image retention, the polymer component contained in the liquid crystal alignment agent 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.

[0170] As the compounds used to promote imidization, preferred compounds are those having a basic site (e.g., primary amino group, aliphatic heterocycle (e.g., pyrrolidine skeleton), aromatic heterocycle (e.g., imidazole ring, indole ring), guanidine group, etc.) (excluding the aforementioned crosslinking compounds and binding aids) or compounds that generate the aforementioned basic site during calcination. More preferred are compounds that generate the aforementioned basic site during calcination. Specific examples include amino acids in which part or all of the basic site is protected by a protecting group (e.g., a Boc group or a 9-fluorenemethoxycarbonyl group, etc., carbamate protecting group). Specific examples of such amino acids include: glycine, alanine, cysteine, methionine, asparagine, glutamic acid, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, and ornithine. If we were to list more preferred examples of compounds for promoting imidization, N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butyloxycarbonyl)-L-histidine would be given.

[0171] The content of the compound used to promote imidization is preferably 2 moles or less, more preferably 1 mole or less, and even more preferably 0.5 moles or less, relative to 1 mole of the ammonium or ammonium ester portion of the polyamic acid or polyamic acid.

[0172] 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 liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) should be appropriately selected considering factors such as viscosity and volatility, and is preferably in the range of 1 to 10% by mass.

[0173] 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 in the range of 1.5 to 4.5% by mass. When using printing, the solid component concentration is particularly preferably in the range of 3 to 9% by mass, thereby setting the solution viscosity to the range of 12 to 50 mPa·s. When using inkjet printing, the solid component concentration is particularly preferably in the range of 1 to 5% by mass, thereby setting the solution viscosity to the range 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.

[0174] <Liquid crystal alignment film / liquid crystal display element>

[0175] The liquid crystal alignment film of the present invention is obtained from the above-described liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used in horizontally aligned or vertically aligned (VA type) liquid crystal display elements, but is preferably used in horizontally aligned liquid crystal display elements such as IPS or FFS types. The liquid crystal alignment film of the present invention is preferably used in liquid crystal alignment processes.

[0176] The liquid crystal display element of the present invention includes the liquid crystal alignment film described above, and can be manufactured, for example, by a method including the following steps (1) to (3) and (5) or steps (1) to (2) and (5). More preferably, it can be manufactured by a method including steps (1) to (5).

[0177] <Process (1): The process of coating the liquid crystal alignment agent onto the substrate>

[0178] Step (1) is the process of applying a liquid crystal alignment agent onto a substrate. A specific example of step (1) is described below.

[0179] For example, a liquid crystal alignment agent is applied to one side of a substrate having a patterned transparent conductive film using appropriate coating methods such as roller coating, spin coating, printing, or inkjet coating. Here, the substrate material is not particularly limited as long as it is highly transparent; it can also be used with glass, silicon nitride, or plastics such as acrylic or polycarbonate. Furthermore, in reflective liquid crystal display elements, if the substrate is only on one side, an opaque material such as a silicon wafer can be used, and the electrodes can be made of light-reflecting materials such as aluminum. Additionally, in the manufacture of IPS or FFS type liquid crystal display elements, a substrate having electrodes composed of a patterned comb-shaped transparent conductive film or metal film and an opposing substrate without electrodes are used.

[0180] Methods for coating a liquid crystal alignment agent onto a substrate and forming a film include screen printing, offset printing, flexographic printing, inkjet printing, and spraying. Among these, inkjet printing is preferred.

[0181] <Process (2): The process of firing the coated liquid crystal alignment agent>

[0182] 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 described below.

[0183] After the liquid crystal alignment agent is coated onto the substrate in step (1), the solvent can be evaporated by a heating unit such as a heating plate, a thermal cycling oven, or an IR (infrared) oven; or thermal imidization of polyamic acid or polyamic ester can be performed. The drying and firing steps after coating the liquid crystal alignment agent of the present invention can be performed at any temperature and time, and can be repeated multiple times. As for the firing temperature, it can be performed at 40 to 180°C for example. From the viewpoint of shortening the process, it can be performed at 40 to 150°C. The firing time at this time is not particularly limited, and examples include 1 to 10 minutes or 1 to 5 minutes. In the case of thermal imidization of polyamic acid or polyamic ester, for example, a firing step can be added at 150 to 300°C or 150 to 250°C. The firing time at this time is not particularly limited, and examples include 5 to 40 minutes or 5 to 30 minutes.

[0184] If the film after firing 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.

[0185] <Process (3): The process of performing orientation treatment>

[0186] Step (3) is a step of aligning the fired film (coating) obtained in step (2) as needed. That is, in horizontally aligned liquid crystal display elements such as IPS or FFS, the coating is subjected to an alignment capability imparting treatment. On the other hand, in vertically aligned liquid crystal display elements such as VA or PSA (Polymer Sustained Alignment), the formed coating can be kept in this state and used as a liquid crystal alignment film, or the coating can be subjected to an alignment capability imparting treatment. As an alignment treatment method for liquid crystal alignment films, rubbing treatment and photo-alignment treatment can be listed, with photo-alignment treatment being more preferred. As a photo-alignment treatment method, the following method can be listed: irradiating the surface of the above-mentioned film with radiation biased in a certain direction, and, depending on the situation, preferably performing a heat treatment at a temperature of 150 to 250°C to impart liquid crystal alignment (also called liquid crystal alignment capability). As the radiation, 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 ultraviolet light with a wavelength of 200 to 400 nm is more preferred.

[0187] The preferred radiation dose is 1–10,000 mJ / cm². 2 More preferably, it is 100–5000 mJ / cm². 2 More preferably, it is 100–1500 mJ / cm 2 The preferred value is 100–1000 mJ / cm³. 2 More preferably, it is 100–400 mJ / cm 2 When using a conventional liquid crystal alignment agent, the light irradiation dose during the alignment process is 100–5000 mJ / cm². 2 However, in the liquid crystal alignment agent of the present invention, even if the amount of light irradiation during the alignment process is reduced, a liquid crystal alignment film that suppresses the non-uniformity of liquid crystal alignment within the liquid crystal alignment film surface can be obtained.

[0188] Furthermore, to improve liquid crystal alignment when irradiated with radiation, the substrate having the above-mentioned film can be irradiated while being heated at 50–250°C. The liquid crystal alignment film produced in this way allows the liquid crystal molecules to be stably aligned in a certain direction.

[0189] Furthermore, in the above methods, a solvent can also be used to contact the liquid crystal alignment film irradiated with polarized radiation; or the liquid crystal alignment film irradiated with radiation can be heated.

[0190] The solvent used in the above-described contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film-like material by radiation irradiation. 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, cyclohexyl acetate, etc. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred from the perspective of versatility and solvent safety. Water, 1-methoxy-2-propanol, or ethyl lactate are more preferred. One solvent may be used, or a combination of two or more may be used.

[0191] <Process (4): The process of performing heat treatment>

[0192] Step (4) is a step of heating the liquid crystal alignment film that has undergone alignment treatment in step (3). The irradiated film (coating) that has been irradiated with radiation may also be subjected to heat treatment. The preferred temperature for heat treatment of the irradiated coating is 50–300°C, more preferably 120–250°C. The preferred heat treatment time is 1–30 minutes.

[0193] <Process (5): Process of manufacturing LCD cell>

[0194] Two substrates with liquid crystal alignment films formed thereon are prepared as described above, and liquid crystal is disposed between the two substrates that are arranged opposite each other. Specifically, the following two methods can be listed.

[0195] In the first method, two substrates are first arranged opposite each other with their respective liquid crystal alignment films facing each other, separated by a gap (cell gap). Next, the peripheries of the two substrates are bonded together with a sealant, and a liquid crystal composition is injected into the cell gap defined by the substrate surfaces and the sealant. After contact with the film surface, the injection hole is sealed.

[0196] There are no particular limitations on the liquid crystal composition described above; various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. It should be noted that, hereinafter, liquid crystal compositions with positive dielectric anisotropy will be referred to as positive liquid crystals, and liquid crystal compositions with negative dielectric anisotropy will be referred to as negative liquid crystals.

[0197] 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, steroidal skeletons, benzene rings, or naphthyl rings. It may also contain compounds having two or more rigid sites (mesocrystalline skeletons) within the molecule that exhibit liquid crystal properties (e.g., bimesocrystalline compounds formed by two rigid biphenyl structures or terphenyl structures linked by alkyl groups). The liquid crystal composition may be a nematic liquid crystal composition, a smectic liquid crystal composition, or a cholesteric liquid crystal composition.

[0198] Furthermore, from the viewpoint of improving liquid crystal orientation, the above-mentioned liquid crystal composition may be further supplemented with additives. Such additives include: photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck Co., Ltd.); antioxidants; ultraviolet absorbers; pigments; defoamers; polymerization initiators; or polymerization inhibitors, etc.

[0199] Examples of positive liquid crystal displays include: Merck's ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081.

[0200] Examples of negative liquid crystals include: MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029 manufactured by Merck.

[0201] In addition, in PSA mode, as a liquid crystal containing a compound with polymerizable groups, Merck's MLC-3023 can be cited as an example.

[0202] In addition, a second method is known as the ODF (One Drop Fill) method. For example, a UV-curable sealant 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 several predetermined points on the surface of the alignment film. Next, the other substrate is bonded with the alignment film facing it, and the liquid crystal composition is spread across the entire surface of the substrate, contacting the film surface. Then, the entire surface of the substrate is irradiated with UV light to cure the sealant. Regardless of the method used, it is ideal to further heat the liquid crystal composition to a temperature at which it becomes an isotropic phase, and then slowly cool it to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0203] It should be noted that when the coating has been rubbed, the two substrates are arranged at a specified angle to each other with the rubbing direction of each coating, for example, in an orthogonal or antiparallel manner.

[0204] As a sealant, epoxy resin containing a curing agent and alumina spheres as spacers can be used, for example. Nematic liquid crystals and smectic liquid crystals can be cited as examples, with nematic liquid crystals being preferred.

[0205] Furthermore, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of polarizing plates attached to the outer surface of the liquid crystal cell include: a polarizing plate made by sandwiching a polarizing film called an "H film" between a cellulose acetate protective film; or a polarizing plate composed of the H film itself, wherein the H film is formed by absorbing iodine while extending and oriented polyvinyl alcohol.

[0206] The IPS substrate, which is a comb electrode substrate used in the IPS method, has: a substrate; a plurality of linear electrodes formed on the substrate and arranged in a comb shape; and a liquid crystal alignment film formed on the substrate to cover the linear electrodes.

[0207] It should be noted that the FFS substrate, which is the comb electrode substrate used in the FFS method, 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 to cover the linear electrodes.

[0208] 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.

[0209] exist Figure 1 In the lateral electric field liquid crystal display element 1 illustrated in the example, liquid crystal 3 is held between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and an opposing substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has: a substrate 2a; a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-like configuration; and a liquid crystal alignment film 2c formed on the substrate 2a to cover the linear electrodes 2b. The opposing substrate 4 has: 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 4a is also, likewise, the liquid crystal alignment film of the present invention.

[0210] In this 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.

[0211] Figure 2This is a schematic partial cross-sectional view showing another example of the transverse electric field liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element.

[0212] exist Figure 2 In the lateral electric field liquid crystal display element 1 illustrated in the example, liquid crystal 3 is held between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and an opposing substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has: 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 configuration; and a liquid crystal alignment film 2h formed on the insulating film 2f to cover the linear electrodes 2g. The opposing substrate 4 has: 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.

[0213] In this transverse electric field liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the linear electrode 2g, an electric field is generated between the surface electrode 2e and the linear electrode 2g as shown by the electric field line L.

[0214] Example

[0215] The following examples illustrate the present invention in further detail, but the invention is not intended to be limited to these specific examples. The abbreviations of the compounds used and the methods for determining their properties are described below.

[0216] (Diamine)

[0217]

[0218] (Tetracarboxylic acid dianhydride)

[0219]

[0220] (Esterifying agent)

[0221]

[0222] (additive)

[0223]

[0224] (solvent)

[0225] NMP: N-methyl-2-pyrrolidone; GBL: γ-butyrolactone.

[0226] BCS: Ethylene glycol monobutyl ether.

[0227] (Viscosity measurement)

[0228] The measurement was performed using a TVE-22H type E viscometer (manufactured by Toki Sangyo Co., Ltd.), with a sample volume of 1.1 mL, using a conical rotor TE-1 (1°34', R24), at a temperature of 25°C.

[0229] ( 1 (H-NMR determination)

[0230] Fourier transform superconducting nuclear magnetic resonance (FT-NMR) device (AVANCE III, manufactured by BRUKER) 500MHz.

[0231] (Determination of esterification rate)

[0232] 150 mg of a 12% by mass polyamic acid ester NMP solution was added to an NMR sample tube (a φ5 NMR standard sampling tube manufactured by Kusano Science Co., Ltd.), followed by 0.53 mL of a mixture of deuterated dimethyl sulfoxide (DMSO-d6 and 0.05% TMS (tetramethylsilane)). The solution was then sonicated until completely dissolved. The concentration of the solution was determined. 1 H-NMR. In terms of esterification rate, the proton originating from the structure that does not change before and after esterification is determined as the reference proton. The peak integral value of this proton and the peak integral value of the proton originating from the COOH group of carboxylic acid appearing around 11 to 13.5 ppm are used to calculate the esterification rate using the following formula.

[0233] Esterification rate (%) = (1 - α·x / y) × 100

[0234] In the above formula, x is the proton peak integral value of the COOH group derived from the carboxylic acid, y is the peak integral value of the reference proton, and α is the ratio of the number of reference protons to the number of COOH protons of the carboxylic acid in the case of polyamic acid (esterification rate of 0%).

[0235] <Determination of imidization rate>

[0236] 20 mg of polyimide powder was added to an NMR sample tube (NMR standard sampling tube, φ5 (manufactured by Kusano Science Co., Ltd.)), followed by 0.53 mL of deuterated dimethyl sulfoxide (0.05% TMS mixture). The solution was then sonicated until completely dissolved. The concentrations of the solution were determined. 1 H-NMR. In terms of imidization rate, the proton originating from the structure that does not change before and after imidization is determined as the reference proton, and the peak integral value of this proton and the peak integral value of the proton originating from the NH group of the amic acid that appears around 9.5 to 10.0 ppm are used to calculate the following formula.

[0237] Imidification rate (%) = (1 - α·x / y) × 100

[0238] In the above formula, x is the proton peak integral value of the NH group derived from amic acid, y is the peak integral value of the reference proton, and α is the ratio of the number of reference protons to the number of NH protons of amic acid in the case of polyamic acid (imidization rate of 0%).

[0239] <Synthesis of Polyamic Acid>

[0240] (Synthesis example 1)

[0241] A1 (0.541 g, 5.00 mmol), A2 (1.83 g, 7.50 mmol), A3 (2.40 g, 7.50 mmol), A4 (1.99 g, 5.00 mmol), B1 (5.31 g, 23.7 mmol), and NMP (88 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at 40 °C for 20 hours to obtain a polyamic acid (PAA-1) solution with a solid content of 12% by mass (viscosity: 400 mPa·s).

[0242] (Synthesis example 2)

[0243] A5 (2.99 g, 15.0 mmol), A6 (2.11 g, 5.00 mmol), A7 (1.49 g, 5.00 mmol), B2 (6.91 g, 23.5 mmol), and NMP (99 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at 40 °C for 20 hours to obtain a polyamic acid (PAA-2) solution with a solid content of 12% by mass (viscosity: 380 mPa·s).

[0244] (Synthesis example 3)

[0245] A1 (0.541 g, 5.00 mmol), A2 (1.83 g, 7.50 mmol), A3 (2.40 g, 7.50 mmol), A8 (1.71 g, 5.00 mmol), B1 (5.31 g, 23.7 mmol), and NMP (86 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at 40 °C for 20 hours to obtain a polyamic acid (PAA-3) solution with a solid content of 12% by mass (viscosity: 400 mPa·s).

[0246] <Synthesis of Polyamates>

[0247] (Synthesis Example 4)

[0248] A solution (30.0 g) of polyamic acid (PAA-1) was aliquoted into a 100 mL Erlenmeyer flask equipped with a nitrogen inlet tube, and Cl (12.7 g) was added. The mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic ester (PAE-1). The esterification rate of this polyamic ester was 60%.

[0249] (Synthesis Example 5)

[0250] A solution (42.7 g) of polyamic acid ester (PAE-1) was injected into isopropanol (214 g), and the resulting precipitate was filtered off. The precipitate was washed with isopropanol and dried under reduced pressure at 80 °C to obtain polyamic acid ester powder. NMP (26.4 g) was added to the obtained polyamic acid ester powder (3.6 g), and the mixture was stirred at 70 °C for 20 hours to dissolve it, thereby obtaining a polyamic acid ester solution (PAE-1A).

[0251] (Synthesis Example 6)

[0252] The amount of C1 added was set to 6.35 g, and otherwise, a solution of polyamic acid ester (PAE-2) was obtained by the same method as in Synthesis Example 4. The esterification rate of this polyamic acid ester was 28%.

[0253] <Synthesis of Polyimide>

[0254] (Synthesis Example 7)

[0255] A solution (60.0 g) of polyamic acid (PAA-3) was aliquoted into a 200 mL Erlenmeyer flask. NMP (20.0 g) was added, followed by acetic anhydride (4.65 g) and pyridine (0.60 g). The mixture was reacted at 55 °C for 2 hours. The reaction solution was then injected into methanol (341 g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 80 °C to obtain polyimide powder. The imidization rate of this polyimide was 66%. NMP (48.4 g) was added to the obtained polyimide powder (6.6 g), and the mixture was stirred at 60 °C for 24 hours to dissolve it, thus obtaining a polyimide (SPI-1) solution.

[0256] Table 1 summarizes the types and amounts of diamine and tetracarboxylic anhydride components used in Synthetic Examples 1–7. In Table 1, the values ​​in parentheses indicate the amount (mole parts) of the monomer used relative to a total of 100 moles for each component.

[0257] [Table 1]

[0258]

[0259] <Preparation of Liquid Crystal Alignment Agent>

[0260] (Example 1)

[0261] To the polyamic acid ester (PAE-1) solution (2.75 g) obtained in Synthesis Example 4, a polyamic acid (PAA-2) solution (6.42 g), NMP (4.83 g), and BCS (6.00 g) obtained in Synthesis Example 2 were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (V-1).

[0262] (Example 2) to (Example 3)

[0263] The polyamic acid ester solution used was changed from solution (PAE-1) to solutions (PAE-1A) and (PAE-2), and otherwise carried out in the same manner as in Example 1, thereby obtaining liquid crystal alignment agents (V-2) and (V-3).

[0264] (Refer to Example 1)

[0265] To the polyamic acid ester (PAE-1A) solution (9.17 g) obtained in Synthesis Example 5, 0.550 g of NMP 10% mass dilution solution of AD-1, 4.28 g of NMP, and 6.00 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain liquid crystal alignment agent (SV-1).

[0266] (Comparative Example 1)

[0267] The polymer solution used was changed from a polyamic acid ester (PAE-1) solution to a polyamic acid (PAA-1) solution, and otherwise carried out in the same manner as in Example 1, thereby obtaining a liquid crystal alignment agent (RV-1).

[0268] (Comparative Example 2)

[0269] Add the polyamic acid (PAA-2) solution (2.50 g), NMP (2.77 g), GBL (4.90 g), and BCS (4.00 g) obtained in Synthesis Example 2 to the polyimide (SPI-1) solution (5.83 g) obtained in Synthesis Example 7, and stir at room temperature for 2 hours to obtain liquid crystal alignment agent (RV-2).

[0270] (Comparative Example 3)

[0271] The polymer solution used was changed from polyamic acid ester (PAE-1A) solution to polyamic acid (PAA-1) solution, and the same procedure was followed as in Reference Example 1, thereby obtaining liquid crystal alignment agent (RV-3).

[0272] (Comparative Example 4)

[0273] To the polyimide (SPI-1) solution (8.33 g) obtained in Synthesis Example 7, 0.50 g of NMP10% mass dilution solution of AD-1, 4.93 g of NMP, 2.33 g of GBL, and 4.00 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain liquid crystal alignment agent (RV-4).

[0274] The specifications of the liquid crystal alignment agents obtained in Examples 1-3, Reference Example 1, and Comparative Examples 1-4 are shown in Table 2.

[0275] [Table 2]

[0276]

[0277] Using the liquid crystal alignment agents obtained above, FFS-driven liquid crystal cells were fabricated in the following order, and various evaluations were performed.

[0278] <Composition of FFS-driven liquid crystal cells>

[0279] A liquid crystal cell with an FFS mode liquid crystal display element was manufactured.

[0280] First, a substrate with electrodes was prepared. The substrate was a rectangular glass plate measuring 30mm × 50mm and 0.7mm thick. On the substrate, an ITO electrode with a dense pattern, constituting the counter electrode, was formed as the first layer. On the counter electrode of the first layer, a SiN (silicon nitride) film, deposited by CVD (chemical vapor deposition), was formed as the second layer. The SiN film of the second layer was a 300nm thick film that served as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning the ITO film was disposed as the third layer, forming two types of pixels: a first pixel and a second pixel. Each pixel had dimensions of 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 were electrically insulated by the SiN film of the second layer.

[0281] The pixel electrode of the third layer has a comb-like shape in which multiple 3μm wide electrode elements with an inner angle of 160° are arranged in parallel with a 6μm interval. Each pixel has a first region and a second region, with the line connecting the curved parts of the multiple electrode elements as the boundary.

[0282] Next, the liquid crystal alignment agents (V-1) to (V-3) and (RV-1) to (RV-2) obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were filtered through filters with a pore size of 1.0 μm and then coated onto the surface of the prepared electrode substrate (first glass substrate) and the surface of a glass substrate (second glass substrate) with an ITO film on the back side and columnar spacers with a height of 4 μm using a spin coating method. After drying on a heating plate at 80°C for 2 minutes, the coating was fired in a hot air circulating oven at 230°C for 30 minutes to form a coating film with a thickness of 100 nm. The coating surface was then irradiated with linearly polarized ultraviolet light of 254 nm wavelength and extinction ratio of 26:1, as shown in Table 3, through a polarizer to perform alignment treatment, thereby obtaining a substrate with a liquid crystal alignment film. It should be noted that, regarding the liquid crystal alignment film formed on the aforementioned substrate with electrodes, the alignment process is performed such that the direction in which the inner angles of the pixel bends are equally divided is orthogonal to the alignment direction of the liquid crystal. Regarding the liquid crystal alignment film formed on the second glass substrate, the alignment process is performed such that the alignment direction of the liquid crystal on the first glass substrate is consistent with the alignment direction of the liquid crystal on the second glass substrate when the liquid crystal cell is manufactured. Using the two substrates as a group, a sealant (Mitsui Chemicals XN-1500T) is printed on the substrate, and the other substrate is bonded with the liquid crystal alignment film surfaces facing each other and the alignment direction at 0°. Then, the sealant is heat-treated at 150°C for 60 minutes to cure it, producing an empty cell. Liquid crystal MLC-3019 (Merck) is injected into this empty cell using a reduced-pressure injection method, and the injection port is sealed to obtain an FFS-driven liquid crystal cell. The obtained liquid crystal cell is then heated at 120°C for 1 hour and left to stand overnight for evaluation.

[0283] <Evaluation of in-plane uniformity of contrast>

[0284] The non-uniformity of the torsion angle of liquid crystal display elements was evaluated using AxoStep manufactured by AXOMETRICS. The liquid crystal cell fabricated above was placed on a measuring stage, and the distribution of Circular Retardance within the pixel plane was measured without applying voltage. Three times the standard deviation σ, or 3σ, was calculated. It can be said that the smaller the value of 3σ, the better the in-plane uniformity. As an evaluation criterion, cases with 3σ values ​​below 1.10 were classified as "excellent," cases above 1.10 but below 1.20 were classified as "good," and cases above 1.20 were classified as "poor."

[0285] The evaluation results of liquid crystal display elements using the liquid crystal alignment agents of the above embodiments and comparative examples are shown in Table 3.

[0286] <Evaluation of the stability of liquid crystal alignment>

[0287] This evaluation assesses image retention (also known as AC image retention) caused by the deterioration of the alignment performance of the liquid crystal alignment film during long-term AC driving. It can be considered that the better the stability of the liquid crystal alignment, the higher the suppression effect of AC image retention.

[0288] The FFS-driven liquid crystal cell fabricated above was subjected to an AC voltage of ±4V at a frequency of 60Hz for 120 hours under a constant temperature environment of 60°C. Then, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and this state was maintained at room temperature for one day. For the liquid crystal cell subjected to the above treatment, the deviation in orientation direction between the liquid crystal in the first region and the liquid crystal in the second region of the pixel was calculated in the form of angles when no voltage was applied. Specifically, the liquid crystal cell was placed between two polarizing plates arranged orthogonally to the polarization axes, the backlight was turned on, and the arrangement angle of the liquid crystal cell was adjusted to minimize the transmitted light intensity in the first region of the pixel. Then, the rotation angle required to minimize the transmitted light intensity in the second region of the pixel was determined. It can be said that the smaller the value of this rotation angle, the better the stability of the liquid crystal orientation. As an evaluation criterion, cases with a rotation angle value less than 0.10° were designated as "excellent," cases with a value greater than 0.10° and less than 0.20° were designated as "good," and cases with a value greater than 0.20° were designated as "poor."

[0289] The evaluation results of liquid crystal display elements using the liquid crystal alignment agents of Examples 1-3 and Comparative Examples 1-2 described above are shown in Table 3.

[0290] [Table 3]

[0291]

[0292] As shown in Table 3, liquid crystal alignment films obtained by liquid crystal alignment agents that are mixtures of specific polyamic acid and specific polyamic acid exhibit higher in-plane uniformity or higher stability of liquid crystal alignment with less ultraviolet irradiation compared to liquid crystal alignment films obtained by liquid crystal alignment agents that are mixtures of two polyamic acids or mixtures of polyimide and polyamic acid.

[0293] <Abrasion Resistance Test>

[0294] Next, in order to confirm the strength of the liquid crystal alignment films formed using the liquid crystal alignment agents obtained in Reference Example 1 and Comparative Examples 3-4, abrasion resistance tests were conducted. It can be considered that the better the abrasion resistance test evaluation, the less likely the liquid crystal alignment film is to peel off from the substrate.

[0295] Using spin coating, liquid crystal alignment agents (SV-1) and (RV-3) to (RV-4) obtained in Reference Example 1 and Comparative Examples 3-4 were respectively coated onto the ITO surface of a glass substrate with ITO electrodes. After drying on a hot plate at 80°C for 2 minutes, the coating was fired in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 100 nm. The coating film was subjected to polarized ultraviolet light at a concentration of 300 mJ / cm². 2 The substrate was irradiated in a specific manner to achieve an alignment process. It was then fired again in an IR oven at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film.

[0296] The substrate with the liquid crystal alignment film obtained above was subjected to friction treatment using rayon cloth (roller diameter: 120 mm, roller speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.6 mm), and then microscopic observation was performed to evaluate the friction resistance of the liquid crystal alignment film.

[0297] The case where no stripes caused by the friction process are seen on the liquid crystal alignment film surface is rated as "0", and the case where stripes are seen is rated as "×".

[0298] The evaluation results of the abrasion resistance test of the liquid crystal alignment films formed using the liquid crystal alignment agents obtained in Reference Example 1 and Comparative Examples 3-4 are shown in Table 4 below.

[0299] [Table 4]

[0300]

[0301] As shown in Table 4, the liquid crystal alignment film obtained from the liquid crystal alignment agent of polyamic acid ester (PAE-1A) exhibits the same abrasion resistance as the liquid crystal alignment film obtained from polyamic acid (PAA-1), and shows higher abrasion resistance than the liquid crystal alignment film obtained from polyimide (SPI-1). Therefore, it is demonstrated that the liquid crystal alignment film of the present invention, obtained from the liquid crystal alignment agent containing polyamic acid ester (A) and polyamic acid (B), exhibits high abrasion resistance comparable to that of the liquid crystal alignment film obtained from the liquid crystal alignment agent containing polyamic acid, and further exhibits higher abrasion resistance than the liquid crystal alignment film obtained from the liquid crystal alignment agent containing polyimide and polyamic acid.

[0302] Industrial availability

[0303] The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention can be effectively used for various other applications besides liquid crystal display elements for display purposes, dimming windows for controlling light transmission and blocking, and light shutters. For example, it can also be widely used in liquid crystal alignment films for phase retardation films; liquid crystal alignment films for scanning antennas and array antennas; liquid crystal alignment films for transmission and scattering type liquid crystal dimming elements; and other applications, such as protective films (e.g., protective films for color filters), spacer films, interlayer insulating films, anti-reflective films, wiring coating films, anti-static films, motor insulating films (gate insulating films for flexible displays), etc.

[0304] Explanation of reference numerals in the attached figures

[0305] 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.

[0306] It should be noted that the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-105052, filed on June 24, 2021, are incorporated herein by reference as a disclosure of the present invention.

Claims

1. A liquid crystal alignment agent, characterized in that, It contains components A and B as described below. Component A: Polyamic acid ester A having a structural unit a-1Ta as a structural unit derived from a tetracarboxylic acid derivative, and having two or more structural units a-1Da as structural units derived from a diamine. Component B: Polyamic acid B having structural units b-1Tb derived from tetracarboxylic acid derivatives as shown in formula (1Tb) and structural units b-1Db derived from diamines as shown in formula (1Db). In equation (1Ta), R 11 and R 14 It is methyl, and R 12 and R 13 R1 represents a hydrogen atom; each of the two R1s independently represents a hydrogen atom or a tertiary alkyl group, at least one of which represents a tertiary alkyl group; in formula (1Da), Y1 is a divalent organic group as shown in formula (H1); Z independently represents a hydrogen atom or a monovalent organic group. In equation (H1), Ar1 and Ar 1’ Each independently represents a benzene ring, biphenyl structure, or naphthalene ring; Ar1, Ar 1’ Any hydrogen atom on the ring may be optionally replaced by a monovalent group; A represents a divalent organic group with 1 to 10 carbon atoms having an alkylene structure; L1, L 1’ Each of these can independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -C(=O)-NR-, or -NR-C(=O)-, where -C(=O)-NR- represents a hydrogen atom or a monovalent organic group, and where -NR-C(=O)- represents a hydrogen atom or a monovalent organic group; * indicates a bond. In equation (1Tb), X b Representing a tetravalent organic group, in formula (1Db), Y b The Z indicates a divalent organic group, and the two Zs each independently represent a hydrogen atom or a monovalent organic group.

2. The liquid crystal alignment agent according to claim 1, wherein, In the formula (H1), A can be any of the following groups, where R represents a hydrogen atom or a monovalent organic group; the two Rs may optionally be the same or different from each other; n is an integer from 1 to 10; *-(CH2) n1 -O-(CH2) n2 -* In this context, n1 and n2 are each independent integers from 1 to 6, and the sum of n1 and n2 is from 2 to 10; *- (CH2) n1 -NR-C (=O) -NR- (CH2) n2 In the asterisk (*), n1 and n2 are each independent integers from 1 to 6, and the sum of n1 and n2 is 2 to 9; m1 and m2 are each independent integers from 0 to 4, n' is an integer from 1 to 6, and the sum of m1, m2, and n' is 1 to 8; * indicates a bond. *-(CH2) n -*、 *-(CH2) n1 -O-(CH2) n2 -*, *-(CH2) m1 -O-C(=O)-(CH2) n’ -C(=O)-O-(CH2) m2 -*, *-(CH2) m1 -C(=O)-O-(CH2) n’ -O-C(=O)-(CH2) m2 -*, *-(CH2) n1 -NR-C(=O)-NR-(CH2) n2 -*.

3. The liquid crystal alignment agent according to claim 1 or 2, wherein, The polyaminate A has structural units of formula (1Da) as structural units derived from diamines, wherein at least one of Y1 is Ar1 and Ar2. 1’ The other Y1 groups are divalent organic groups of the same structure as those shown in formula (H1), and at least one of them is Ar1 and Ar2. 1’ The divalent organic groups are represented by formula (H1) with different structures.

4. The liquid crystal alignment agent according to claim 1 or 2, wherein, The polyamic acid ester A contains at least one structural unit of formula (1Da) as a diamine-derived structural unit, wherein Y1 is a divalent organic group having three or more benzene rings.

5. The liquid crystal alignment agent according to claim 1 or 2, wherein, In formula (1Da), Y1 is any divalent organic group represented by any of the formulas (h1-1) to (h1-13) below. In formula (h1-4), the total number of -CH2- is 10 or less; in formulas (h1-7) and (h1-8), the total number of -CH2- is 8 or less, and the two m may be the same or different from each other; * indicates a bond.

6. The liquid crystal alignment agent according to claim 1 or 2, wherein, In the formula (1Tb), X b A tetravalent organic group is a tetravalent organic group formed by removing two acid dianhydride groups from an acyclic aliphatic tetracarboxylic dianhydride, a tetravalent organic group formed by removing two acid dianhydride groups from an alicyclic tetracarboxylic dianhydride, or a tetravalent organic group formed by removing two acid dianhydride groups from an aromatic tetracarboxylic dianhydride, and is a tetravalent organic group derived from 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 structure, a cyclopentane ring structure, and a cyclohexane ring structure.

7. The liquid crystal alignment agent according to claim 1 or 2, wherein, Polyamate A contains a-1Ta, a structural unit comprising more than 5 mol% of all structural units derived from tetracarboxylic acid derivatives per 1 mole.

8. The liquid crystal alignment agent according to claim 1 or 2, wherein, Polyamate A comprises 5 to 95 mol% of the structural unit a-1Da relative to all diamine-derived structural units of polyamate A.

9. The liquid crystal alignment agent according to claim 1 or 2, wherein, The liquid crystal alignment agent is used to form a liquid crystal alignment film for photoalignment processing.

10. A liquid crystal alignment film obtained from a liquid crystal alignment agent as described in any one of claims 1 to 9.

11. A liquid crystal display element comprising the liquid crystal alignment film as described in claim 10.

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 as described in any one of claims 1 to 9 onto the substrate; Step 2: The process of firing the coated liquid crystal alignment agent; Step 3: The step of oriented treatment of the sintered film obtained in Step 2.

13. The method for manufacturing a liquid crystal display element according to claim 12, wherein, The orientation process is a photo-orientation process.

14. The method for manufacturing a liquid crystal display element according to claim 13, wherein, The radiation dose during the photoorientation process is 100–1500 mJ / cm². 2 .

15. A method for manufacturing a liquid crystal display element according to any one of claims 12 to 14, wherein, It also includes the following process 4, Step 4: A step of further heating the fired film that underwent orientation treatment in Step 3 at 50–300°C.

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