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

Abstract

A liquid crystal alignment agent comprises a polymer component (A), a solvent (B) and a compound (C). The polymer component (A) comprises a first polymer (A1). The first polymer (A1) is selected from at least one of a group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor, and the polyimide precursor of the first polymer (A1) has a structure as shown in formula (I). The compound (C) has a structure represented by formula (C1). The definitions of the formula (I) and the formula (C1) are respectively described in the description and the claims. The invention also provides a liquid crystal alignment film formed by using the liquid crystal alignment agent, and a liquid crystal display element comprising the liquid crystal alignment film. The first polymer (A1) and the compound (C) can effectively reduce the in-pixel contrast variability and friction broken bright spots of the liquid crystal display element.

Description

Technical Field

[0001] This invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element, and particularly to a liquid crystal alignment agent that can reduce intra-pixel contrast variation and friction-induced bright spots, a liquid crystal alignment film formed from the liquid crystal alignment agent, and a liquid crystal display element comprising the liquid crystal alignment film. Background Technology

[0002] Liquid crystal display (LCD) elements are widely used as display components in personal computers, smartphones, mobile phones, and television receivers. An LCD element may include a liquid crystal layer sandwiched between a substrate and a color filter substrate, pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer, a liquid crystal alignment film that controls the alignment of the liquid crystal molecules in the liquid crystal layer, and a thin-film transistor (TFT) that switches the electronic signals supplied to the pixel electrodes. Regarding the driving method of the liquid crystal molecules, known methods include longitudinal electric field driving methods such as twisted nematic (TN) and vertical alignment (VA), and transverse electric field driving methods such as in-plane switching (IPS) and fringe field switching (FFS).

[0003] Currently, the most common liquid crystal alignment film in industry is made by rubbing the surface of a film formed on an electrode substrate with polyamic acid and / or polyimide obtained by imidization in one direction using cotton cloth, nylon cloth, or polyester cloth. Friction treatment is a simple, high-productivity, and commonly used alignment treatment method in industry. However, with the increasing performance, image quality, and size of liquid crystal display elements, the surface of the liquid crystal alignment film is scratched by dust, mechanical force, and static electricity generated during friction treatment, leading to various problems such as alignment inhomogeneity. As an alternative to friction treatment, photoalignment methods are known to impart alignment capability to the liquid crystal by irradiating it with polarized radiation, such as the photoalignment method disclosed in Japanese Patent Application Publication No. H09-297313.

[0004] However, although the liquid crystal alignment film prepared by photoalignment can avoid the problems caused by the alignment process using friction, when the liquid crystal alignment film prepared by photoalignment is applied to liquid crystal display elements, especially to manufacture large liquid crystal display elements with curved shapes, as the size of the liquid crystal display element becomes larger, the twist angle of the liquid crystal molecules in the liquid crystal display element changes due to the changes in the manufacturing process. When black is displayed on the liquid crystal display element, this change in twist angle will cause uneven brightness within the liquid crystal display element, resulting in high contrast variation within the pixels of the liquid crystal display element. Furthermore, because the curved shape of the liquid crystal panel is bent along the shape of the liquid crystal display element's housing, the interstitial bodies inside the liquid crystal panel move within the panel and rub against the liquid crystal alignment film. The liquid crystal alignment film is also affected by the local pressure generated by the movement of the interstitial bodies, making it unable to adjust the alignment of liquid crystal molecules. When black is displayed on the liquid crystal display element, friction bright spots are formed due to local light transmission around the interstitial bodies. Based on this, conventional liquid crystal display elements containing liquid crystal alignment films prepared by photoalignment methods still have the problem of too many friction bright spots, leading to a decrease in the quality of the liquid crystal display element. Summary of the Invention

[0005] The first objective of this invention is to provide a liquid crystal alignment agent that enables the preparation of a liquid crystal alignment film that can effectively reduce intra-pixel contrast variation and friction-induced bright spots.

[0006] The liquid crystal alignment agent of the present invention comprises a polymer component (A), a solvent (B), and a compound (C).

[0007] The polymer component (A) includes a first polymer (A1), and the first polymer (A1) is selected from at least one of the group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor.

[0008] The polyimide precursor of the first polymer (A1) comprises a structure as shown in formula (I).

[0009]

[0010] In equation (I), X 1 Selected from at least one of the groups consisting of structures as shown in equations (I-1) to (I-7), where "*" indicates the bond location.

[0011]

[0012]

[0013] In the above formula (I-1), X 11 X 12 X13 and X 14 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group.

[0014] In the above formula (I-7), X 15 and X 16 Each can be independently a hydrogen atom or a methyl group;

[0015] X 2 Each is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;

[0016] A 3 and A 4 Each is an independently substituted or unsubstituted divalent aromatic cyclic group;

[0017] Y 21 and Y 22 Each independently represents a single bond, oxygen atom, sulfur atom, or R 2 Represents a protective base, and the Y 21 and the Y 22 At least one of them is And the Y 21 With the Y 22 Different;

[0018] Z 2 It is a divalent organic group having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure and having 1 to 15 carbon atoms.

[0019] The compound (C) comprises a structure as shown in formula (C1).

[0020]

[0021] In the formula (C1), A is a monovalent to tetravalent organic group.

[0022] n is an integer from 1 to 4.

[0023] L 1 L 2 Each is independently an alkylene group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms.

[0024] R 3 R 4 Each can be represented independently as shown in equation (C2).

[0025]

[0026] In the above formula (C2), R 5It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

[0027] In the liquid crystal alignment agent described in this invention, the X 1 The structure is as shown in equation (I-1).

[0028]

[0029] In the liquid crystal alignment agent described in this invention, the X 1 The structure is as shown in equation (I-1-1).

[0030]

[0031] In the liquid crystal alignment agent described in this invention, the R 2 The protecting group indicated is a carbamate-based protecting group.

[0032] In the liquid crystal alignment agent described in this invention, the structure shown in formula (I) is the same as the structure shown in formula (II).

[0033]

[0034] In the aforementioned formula (II),

[0035] Q 1 and Q 2 Each can independently represent -CH- or nitrogen atom.

[0036] X 1 X 2 Y 21 and Y 22 The definition of X in equation (I) 1 X 2 Y 21 and Y 22 same,

[0037] m 1 Represents integers from 1 to 5.

[0038] In the liquid crystal alignment agent described in this invention, the R 5 It is an alkyl group having 3 to 10 carbon atoms or a haloalkyl group having 10 to 15 carbon atoms.

[0039] In the liquid crystal alignment agent described in this invention, n is an integer from 2 to 4.

[0040] In the liquid crystal alignment agent described in this invention, formula (C1) has the structure shown in formula (C3).

[0041]

[0042] In the aforementioned formula (C3),

[0043] A' is an alkylene group having 1 to 10 carbon atoms.

[0044] L 1’ To L 4’ Each is independently an alkylene group having 1 to 5 carbon atoms.

[0045] R 3’ To R 6’ Each can be independently represented as shown in equation (C4).

[0046]

[0047] In the aforementioned formula (C4), R 5 It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

[0048] The second objective of this invention is to provide a liquid crystal alignment film that can effectively reduce intra-pixel contrast variation and friction-induced bright spots.

[0049] The liquid crystal alignment film of the present invention is formed using the liquid crystal alignment agent described above.

[0050] In the liquid crystal alignment film of the present invention, the liquid crystal alignment film is formed by using the liquid crystal alignment agent as described above and performing a photoalignment process.

[0051] A third objective of this invention is to provide a liquid crystal display element.

[0052] The liquid crystal display element of the present invention includes a liquid crystal alignment film as described above.

[0053] The beneficial effects of the present invention are as follows: by using the first polymer (A1) prepared by using a polyimide precursor containing the structure shown in formula (I) and the compound (C) containing the structure shown in formula (C1), the liquid crystal alignment film formed by the liquid crystal alignment agent can effectively reduce the intra-pixel contrast variation and friction-induced bright spots of the liquid crystal display element. Detailed Implementation

[0054] One aspect of the present invention provides a liquid crystal alignment agent comprising a polymer component (A), a solvent (B), and a compound (C). The polymer component (A) comprises a first polymer (A1), and the first polymer (A1) is selected from at least one of the group consisting of a polyimide precursor and an imidized polymer formed from the polyimide precursor, characterized in that the polyimide precursor of the first polymer (A1) comprises the structure shown in formula (I); the compound (C) comprises the structure shown in formula (C1). The liquid crystal alignment film formed using the liquid crystal alignment agent can effectively reduce intra-pixel contrast variation and scuffing spots.

[0055]

[0056] Another aspect of the present invention is to provide a liquid crystal alignment film formed using the above-described liquid crystal alignment agent.

[0057] Another aspect of the present invention is to provide a liquid crystal display element comprising the aforementioned liquid crystal alignment film, and having lower intra-pixel contrast variation and friction-induced bright spots.

[0058] Polymer Component (A)

[0059] <First Polymer (A1)>

[0060] The first polymer (A1) is selected from at least one of the group consisting of a polyimide precursor formed by reacting a reaction composition comprising a tetracarboxylic dianhydride component (a1) and a diamine component (b1) and an imidized polymer formed from the polyimide precursor. For example, the first polymer (A1) is a polyimide precursor having an imide precursor structure of polyamic acid and polyamic ester, or the first polymer (A1) is an imidized polymer (i.e., a polyimide) formed from the polyimide precursor, or the first polymer (A1) comprises the polyimide precursor and the imidized polymer.

[0061] The polyimide precursor of the first polymer (A1) comprises the structure shown in formula (I).

[0062]

[0063] In equation (I), X 1 The structure is represented by at least one of the groups of structures shown in equations (I-1) to (I-7), where "*" represents the location of the bond.

[0064]

[0065]

[0066] In the above formula (I-1), X 11 X 12 X 13 With X 14 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group.

[0067] In the above formula (I-7), X 15 and X 16Each can be a hydrogen atom or a methyl group independently.

[0068] In equation (I), X 2 Each is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0069] In the aforementioned formula (I), A 3 and A 4 Each is an independent divalent aromatic cyclic group, either substituted or unsubstituted.

[0070] In equation (I), Y 21 and Y 22 Each independently represents a single bond, oxygen atom, sulfur atom, or R 2 Represents a protective base, and the Y 21 and the Y 22 At least one of them is And the Y 21 With the Y 22 They are not the same.

[0071] In equation (I), Z 2 It is a divalent organic group having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure and having 1 to 15 carbon atoms.

[0072] [Tetracarboxylic acid dianhydride component (a1)]

[0073] The tetracarboxylic dianhydride component (a1) can be a tetracarboxylic dianhydride compound, or a tetracarboxylic dianhydride derivative such as a tetracarboxylic dihalide, a tetracarboxylic dialkyl ester, or a tetracarboxylic dialkyl ester dihalide. The tetracarboxylic dianhydride component (a1) can be a single tetracarboxylic dianhydride compound or its derivative, or a combination of multiple compounds.

[0074] [Alicyclic tetracarboxylic dianhydride compound (a1-1)]

[0075] In some embodiments of the present invention, the tetracarboxylic dianhydride component (a1) comprises an alicyclic tetracarboxylic dianhydride (a1-1) or a derivative thereof as shown in formula (A11).

[0076]

[0077] The alicyclic tetracarboxylic dianhydride (a1-1) or its derivatives represented by formula (A11) can be composed of a single tetracarboxylic dianhydride or its derivative, or can be composed of multiple tetracarboxylic dianhydrides or their derivatives. The alicyclic tetracarboxylic dianhydride (a1-1) represented by formula (A11) is, for example, an acid dianhydride obtained by intramolecularly dehydrating four carboxyl groups, including at least one carboxyl group bonded to an alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. Alternatively, it does not necessarily need to be composed solely of an alicyclic structure; a portion of it may also have a chain hydrocarbon structure or an aromatic ring structure. Aromatic tetracarboxylic dianhydrides are, for example, acid dianhydrides obtained by intramolecularly dehydrating four carboxyl groups, including at least one carboxyl group bonded to an aromatic ring. However, aromatic tetracarboxylic dianhydrides do not necessarily need to be composed solely of an aromatic ring structure; a portion of it may also have a chain hydrocarbon structure or an alicyclic structure. Acyclic alicyclic tetracarboxylic dianhydrides can, for example, be acid dianhydrides obtained by intramolecularly dehydrating four carboxyl groups bonded to a chain hydrocarbon structure. However, acyclic aliphatic tetracarboxylic dianhydrides do not necessarily have to be composed solely of chain hydrocarbon structures; a portion of them may also have alicyclic or aromatic ring structures.

[0078] In the aforementioned formula (A11), X 1 It is selected from at least one of the groups consisting of the structures shown in Equations (I-1) to (I-7), and "*" represents the bond position.

[0079]

[0080] In the above formula (I-1), X 11 X 12 X 13 With X 14 Each of these groups independently represents hydrogen, halogen, alkyl (1 to 6 carbon atoms), alkenyl (2 to 6 carbon atoms), alkynyl (2 to 6 carbon atoms), monovalent organic group (1 to 6 carbon atoms containing a fluorine atom), or phenyl. In formula (I-7), X 15 With X 16 Each can be used independently to represent hydrogen or methyl.

[0081] In some embodiments of the present invention, the X 1 The structure shown in formula (I-1) is selected from the structures shown in formulas (I-1-1) to (I-1-6).

[0082]

[0083] In some embodiments of the present invention, preferably, the X 1 The structure is represented by equation (I-1). When the X 1 The liquid crystal display element with a liquid crystal alignment film formed by the liquid crystal alignment agent containing the structure shown in Formula (I-1) has a low intra-pixel contrast variation.

[0084] In some embodiments of the present invention, more preferably, the X 1 The structure is represented by formula (I-1-1). When the X 1 The liquid crystal display element with a liquid crystal alignment film formed by the liquid crystal alignment agent containing the structure shown in Formula (I-1-1) has a lower intra-pixel contrast variation.

[0085] In some embodiments of the present invention, based on the total amount of tetracarboxylic dianhydride component (a1) being 100 moles, the amount of alicyclic tetracarboxylic dianhydride (a1-1) represented by formula (A11) being 30 to 100 moles, preferably, the amount of alicyclic tetracarboxylic dianhydride (a1-1) represented by formula (A11) being 40 to 100 moles, and more preferably, the amount of alicyclic tetracarboxylic dianhydride (a1-1) represented by formula (A11) being 50 to 100 moles.

[0086] When the tetracarboxylic dianhydride component (a1) includes the alicyclic tetracarboxylic dianhydride (a1-1) shown in formula (A11), the liquid crystal display element containing the liquid crystal alignment film formed by the liquid crystal alignment agent has low intra-pixel contrast variation and friction breakage spots, thus the display quality of the liquid crystal display element is good.

[0087] When the tetracarboxylic dianhydride component (a1) does not contain the alicyclic tetracarboxylic dianhydride (a1-1) shown in formula (A11), the liquid crystal display element containing the liquid crystal alignment film formed by the liquid crystal alignment agent is prone to high intra-pixel contrast variation and friction-induced bright spots, resulting in poor display quality of the liquid crystal display element.

[0088] [Other tetracarboxylic acid dianhydrides (a1-2)]

[0089] In some embodiments of the present invention, the tetracarboxylic dianhydride component (a1) further comprises other tetracarboxylic dianhydrides (a1-2).

[0090] In some embodiments of the present invention, the other tetracarboxylic dianhydrides (a1-2) comprise tetracarboxylic dianhydride compounds or derivatives thereof as shown in formula (A12).

[0091]

[0092] In the aforementioned formula (A12), X 1' The structures shown in equations (A12-1) to (A12-32) are represented, where "*" represents the bond position.

[0093]

[0094]

[0095]

[0096]

[0097] In equation (A12-1), a1 is 1 to 12. In equation (A12-5), X... 11' The group represents a single bond, -O-, -CO-, -COO-, phenylene, sulfonyl, or amide group, and a1 represents 0 or 1. In the formula (A12-6), X 11' and X 12' Each of the following groups independently represents a single bond, -O-, -CO-, -COO-, phenylene, sulfonyl, or amide group, and multiple X groups... 12' The values ​​are either the same or different, and a1 represents 0 or 1. In equation (A12-11), a1 represents 2 to 6. In equation (A12-13), a1 represents 1 to 2. In equation (A12-14), X 13' Each of the following can independently represent hydrogen, halogen, alkyl group having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms, alkynyl group having 2 to 6 carbon atoms, monovalent organic group containing fluorine and having 1 to 6 carbon atoms, or phenyl group, and multiple X groups. 13' Whether they are the same or different. From the viewpoint of liquid crystal alignment, preferably, the X... 13' Each of the following can be independently represented as hydrogen, halogen, methyl, or ethyl; more preferably, X... 13' Each can be used independently to represent hydrogen or methyl.

[0098] In some embodiments of the present invention, formulas (A12-5) and (A12-6) include, but are not limited to, […].

[0099]

[0100] In some embodiments of the present invention, based on the total amount of the tetracarboxylic dianhydride component (a1) being 100 moles, the amount of the other tetracarboxylic dianhydrides (a1-2) being 0 to 70 moles, preferably, the amount of the other tetracarboxylic dianhydrides (a1-2) being 0 to 60 moles, and more preferably, the amount of the other tetracarboxylic dianhydrides (a1-2) being 0 to 50 moles.

[0101] [Diamine component (b1)]

[0102] The diamine component (b1) may comprise diamine compound (b1-1) and diamine compound (b1-2). In some embodiments of the present invention, in addition to diamine compounds (b1-1) and (b1-2), the diamine component (b1) may further comprise diamine compound (b1-3). In some embodiments of the present invention, the diamine component (b1) may also selectively further comprise diamine compound (b1-4), other diamine compounds (b1-5), or combinations thereof.

[0103] [Diamine compound (b1-1)]

[0104] The diamine compound (b1-1) is a diamine compound as shown in formula (III) below.

[0105] H2N-A 3 -Y 21 -Z 2 -Y 22 -A 4 -NH2 Formula (III)

[0106] In equation (III), A 3 and A 4 Each can be independently represented by a substituted or unsubstituted divalent aromatic cyclic group; Y 21 and Y 22 Each can independently represent a single bond, oxygen atom, sulfur atom, or R 2 Represents a protective base, and the Y 21 and the Y 22 At least one of them is And the Y 21 With the Y 22 Different; Z 2 It refers to a divalent organic group having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure and having 1 to 15 carbon atoms.

[0107] In the A 3 and the A mentioned above 4 In this context, the substituted divalent aromatic ring group is a group formed by replacing two hydrogen atoms in the ring portion of an aromatic ring with substituents. Examples of the aromatic ring include: aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, and biphenyl ring; and nitrogen-containing heterocycles such as pyridine ring, pyrazine ring, pyrimidine ring, and pyridazine ring. Substituents that the aromatic ring may have include, for example, alkyl groups having 1 to 6 carbon atoms. In the A... 3 and the A mentioned above 4Under the same conditions, diamine compounds (b1-1) can be easily synthesized, and liquid crystal display elements comprising a liquid crystal alignment film formed by the liquid crystal alignment agent exhibit low intra-pixel contrast variability. Regarding A... 3 and the A mentioned above 4 In terms of obtaining a liquid crystal display element with lower intra-pixel contrast variation, the A 3 and the A mentioned above 4 It can be a group formed by removing two hydrogen atoms from the ring portion of a benzene ring, biphenyl ring, pyridine ring, or pyrimidine ring.

[0108] In equation (III), when Y 21 and the Y 22 One of them indicates And R 2 Represents a protective base; the R 2 Any protecting group used to protect amide, imide, urea, or carbamate groups is applicable to this invention and is not particularly limited. Examples include monovalent organic groups that can be removed using at least one of heat, light, acid, and alkali. In some embodiments of this invention, preferably, the R... 2 Examples of monovalent organic groups that can be removed using at least heat include: urethane protecting groups, amide protecting groups, imide protecting groups, sulfonamide protecting groups, etc. In some embodiments of the present invention, preferably, the R... 2 It is a carbamate protecting group, such as: tert-butoxycarbonyl, benzyloxycarbonyl, 1,1-dimethyl-2-haloethoxycarbonyl, 1,1-dimethyl-2-cyanoethoxycarbonyl, 9-fluorenylmethoxycarbonyl, allyloxycarbonyl, 2-(trimethylsilyl)ethoxycarbonyl, etc.

[0109] In some embodiments of the present invention, as the R 2 Specific examples can be listed as the groups represented by formulas (R2-1) to (R2-5) below.

[0110]

[0111] In equations (R2-1) to (R2-5), Ar 1 It is a monovalent aromatic cyclic group with 6 to 10 carbon atoms, R 14 It is an alkyl group having 1 to 12 carbon atoms, R 15 It is a monovalent organic group, and "*" represents the position where it is bonded to a nitrogen atom.

[0112] In the aforementioned formula (R2-2), the Ar 1It is a group formed by removing a hydrogen atom from an aromatic ring having 6 to 10 carbon atoms, such as phenyl, naphthyl, etc. In the above formula (R2-4), R 14 Alkyl groups having 1 to 12 carbon atoms can be exemplified by, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, etc., and these groups can be linear or branched. In the formulas (R2-5), R... 15 Examples of monovalent organic groups include alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms. In some embodiments of the present invention, preferably, the R... 15 It is an aryl group having 6 to 10 carbon atoms, more preferably, the R 15 It is an aryl group such as phenyl or naphthyl. Furthermore, the groups represented by formulas (R2-1) to (R2-4) can be deprotected not only by heat but also by light. In some embodiments of the present invention, there is high thermal deprotection and the ability to remove the R groups that are removed during film formation by heating. 2 From the viewpoint that the compound is discharged as a gas outside the membrane, preferably, the R 2 The R is a carbamate-based protecting group to give the liquid crystal display element lower intra-pixel contrast variation. More preferably, the R... 2 It is tert-butoxycarbonyl to give the liquid crystal display element lower intra-pixel contrast variation.

[0113] In equation (III), Z 2 This refers to a divalent organic group having a chain hydrocarbon structure with 1 to 15 carbon atoms or an alicyclic hydrocarbon structure with 3 to 15 carbon atoms. "Chain hydrocarbon structure" refers to a straight-chain hydrocarbon structure or a branched hydrocarbon structure that contains only chain structures and no cyclic structures. The chain hydrocarbon structure can be saturated or unsaturated. "Alicyclic hydrocarbon structure" refers to a hydrocarbon structure that contains only alicyclic hydrocarbon structures as ring structures and no aromatic ring structures. The alicyclic hydrocarbon structure is not limited to structures containing only alicyclic hydrocarbons; a portion of it may also contain chain structures.

[0114] In some embodiments of the present invention, in formula (III), when A 3 and the A mentioned above 4 When referring to a divalent group formed by removing two hydrogen atoms from the ring portion of a benzene ring, pyridine ring, or pyrimidine ring, the ring portion may have substituents, and the A... 3 With the A 4 They are the same; while the Z mentioned 2 express When n represents an integer from 1 to 5, the liquid crystal display element containing the liquid crystal alignment film formed using the liquid crystal alignment agent has a lower intra-pixel contrast variation.

[0115] In some embodiments of the present invention, based on the viewpoint of lower intra-pixel contrast variability, A in formula (III) is relative to the nitrogen atom in formula (III). 3 With A 4 The preferred bonding position on the represented benzene ring, pyridine ring, or pyrimidine ring is para.

[0116] In some embodiments of the present invention, preferably, the diamine compound (b1-1) represented by formula (III) is a diamine compound represented by formula (III-2).

[0117]

[0118] In equation (III-2), Q 1 and Q 2 Each can be independently represented by -CH- or nitrogen atom; Y 21 and Y 22 The definition of Y in equation (III) 21 and Y 22 The same applies, so I will not repeat it here; m 1 Represents integers from 1 to 5.

[0119] In some embodiments of the present invention, the diamine compound (b1-1) may comprise, but is not limited to, compounds represented by formulas (III-3) to (III-13), preferably, the diamine compound (b1-1) is a compound represented by formula (III-3), a compound represented by formula (III-4), or a compound represented by formula (III-6). Specific compounds of the diamine compound (b1-1) can be synthesized by common methods of suitable combinatorial organic chemistry. The diamine compound (b1-1) may be used alone or in combination. In formulas (III-3) to (III-13), Boc represents t-butyloxycarbonyl.

[0120]

[0121]

[0122]

[0123] When the diamine component (b1) does not contain the diamine compound (b1-1) shown in formula (III), the liquid crystal display element containing the liquid crystal alignment film formed by the liquid crystal alignment agent is prone to high intra-pixel contrast variation and friction breakage spots, resulting in poor display quality of the liquid crystal display element.

[0124] In some embodiments of the present invention, based on the amount of the diamine component (b1) used being 100 moles, the total amount of the diamine compound (b1-1) represented by formula (III) used is 3 to 30 moles, preferably 5 to 25 moles, and more preferably 7 to 20 moles.

[0125] [Diamine compound (b1-2)]

[0126] The diamine compound (b1-2) is a diamine compound as shown in formula (IV) below.

[0127] H2N-A 1 -Y 11 -Z 1 -Y 11 -A 2 -NH2 formula (IV)

[0128] In equation (IV), A 1 and A 2 Each independently represents a substituted or unsubstituted divalent aromatic cyclic group; Y 11 Represents -O-, -S-, -COO-, or -OCO-; Z 1 The structure is represented by the following formula (Z1-1).

[0129]

[0130] In the aforementioned equation (Z1-1), R 1 Represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; m is an integer from 0 to 4, and when m is an integer from 2 to 4, R 1 Each has the above definition independently; n is an integer from 1 to 3, and when n is 2 or 3, R 1 Each of them, m, has the above definition independently; * indicates the bond position.

[0131] In other words, the diamine compound (b1-2) is a diamine compound as shown in the following formula (IV').

[0132]

[0133] In the aforementioned formula (IV'), A 1 A 2 and Y 11 The definition of A in equation (IV) 1 A 2 and Y 11 Same, R 1The definitions of m and n are the same as R in the above formula (Z1-1). 1 The same applies to m and n, so they will not be elaborated upon here.

[0134] In equation (IV) and equation (IV'), A 1 and A 2 Each term independently represents a substituted or unsubstituted divalent aromatic cyclic group, wherein the aforementioned divalent aromatic cyclic group is a group formed by removing two hydrogen atoms from the ring portion of an aromatic ring, and may have substituents in the ring portion. Examples of the aromatic ring include: aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracener rings, and biphenyl rings; nitrogen-containing heterocycles such as pyridine rings, pyrazine rings, pyrimidine rings, and pyridazine rings. Substituents that the aromatic ring may have include, for example, alkyl groups having 1 to 6 carbon atoms. In A 1 and A 2 Under the same conditions, diamine compounds (b1-2) can be easily synthesized, and liquid crystal display elements comprising a liquid crystal alignment film formed by the liquid crystal alignment agent exhibit low intra-pixel contrast variability. Regarding A... 1 and A 2 In terms of obtaining a liquid crystal display element with lower intra-pixel contrast variation, in some embodiments of the present invention, preferably, A 1 and A 2 Each is a group formed by removing two hydrogen atoms from the ring portion of a benzene ring, biphenyl ring, pyridine ring, or pyrimidine ring that may have substituents.

[0135] In some embodiments of the present invention, A in formulas (IV) and (IV') above is... 1 and A 2 Each independently represents a substituted or unsubstituted 1,4-phenylene. When A 1 and A 2 When each of the substituted or unsubstituted 1,4-phenylene groups is represented independently, the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent has lower intra-pixel contrast variability.

[0136] In equation (IV) of the above equation (Z1-1) and equation (IV'), R 1 R represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms, where m is an integer from 2 to 4. 1 Each can be the same or different.

[0137] R in equation (IV) 1In this context, the alkyl group having 1 to 6 carbon atoms can be either straight-chain or branched. Specifically, examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, and isohexyl.

[0138] R in equation (IV) 1 In this context, the alkoxy group having 1 to 6 carbon atoms can be listed as an alkyl group having 1 to 6 carbon atoms that is bonded to an oxygen atom. Specifically, examples include methoxy, ethoxy, etc.

[0139] R in equation (IV) 1 In this context, the fluoroalkyl group having 1 to 6 carbon atoms can be one in which at least one hydrogen atom of the group having 1 to 6 carbon atoms is replaced by a fluorine atom.

[0140] When the diamine component (b1) contains the diamine compound (b1-2) shown in formula (IV), the liquid crystal display element containing the liquid crystal alignment film formed by the liquid crystal alignment agent has low intra-pixel contrast variation, and therefore the display quality of the liquid crystal display element is good.

[0141] In some embodiments of the present invention, when the diamine compound (b1-2) represented by formula (IV) is selected from the structure represented by formula (IV-1) below, the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent has a lower intra-pixel contrast variation.

[0142]

[0143] In the aforementioned formula (IV-1), A 1 A 2 and Y 11 The definition of A in equation (IV) 1 A 2 and Y 11 Same, R 1 The definitions of m and n are the same as R in the above formula (Z1-1). 1 The same applies to m and n, so they will not be elaborated upon here.

[0144] In some embodiments of the present invention, m in formula (IV-1) is an integer from 0 to 4, preferably an integer from 0 to 2, and more preferably, m is 0.

[0145] In some embodiments of the present invention, n in formula (IV-1) is an integer from 1 to 3, preferably n is 1.

[0146] In some embodiments of the present invention, more preferably, the diamine compound (b1-2) represented by formula (IV) is selected from the structure represented by formula (IV-2) below.

[0147]

[0148] In the aforementioned formula (IV-2), Y 11 The definition of Y in equation (IV) 11 Same, R 1 The definitions of m and n are the same as R in the above formula (Z1-1). 1 The same applies to m and n, so they will not be elaborated upon here.

[0149] In the aforementioned formula (IV-2), R 2 Each of the following independently represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms; each of the following independently represents an integer from 0 to 5, preferably r represents 0; when r represents an integer from 2 to 5, R2 independently has the above definition; n is an integer from 1 to 3, and when n is 2 or 3, R1 and m independently have the above definition.

[0150] In some embodiments of the present invention, preferably, the phenyl group linked to the amino group in formula (IV-2) is a substituted or unsubstituted 1,4-phenylene, and therefore, the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent has a lower intra-pixel contrast variation.

[0151] In some embodiments of the present invention, specific examples of the diamine compound (b1-2) may be listed as compounds represented by formulas (IV-3) to (IV-11), preferably, the diamine compound (b1-2) may be listed as compounds represented by formula (IV-3), compounds represented by formula (IV-4), compounds represented by formula (IV-10), and compounds represented by formula (IV-11).

[0152]

[0153]

[0154] The diamine compound (b1-2) represented by formula (IV) or formula (IV') can be manufactured by common organic chemistry methods. The following describes methods for manufacturing the diamine compound (b1-2), but the invention is not limited thereto.

[0155] Specifically, Y 11 For O or S, n is 1 and A 1 A 2In the case of the same nitrobenzene derivative, as shown in reaction formula (1) or reaction formula (2) below, the intermediate product "dinitro compound" can be obtained by reacting a commercially available nitrobenzene derivative substituted with a leaving group (X) with a dihydroxycyclohexane derivative or a dithiol cyclohexane derivative. Preferably, the leaving group (X) can be fluorine, chlorine, bromine, iodine, p-toluenesulfonyl (-OTs), or methanesulfonyl (-OMs). Only reaction formula (1) for the reaction of nitrobenzene derivatives with dihydroxycyclohexane derivatives and reaction formula (2) for the reaction of nitrobenzene derivatives with dithiol cyclohexane derivatives are listed below, but the invention is not limited thereto. The nitrobenzene derivative can be reacted with A 1 A 2 The different ones can be replaced with other nitro aromatic derivatives as reaction raw materials, such as nitrobiphenyl derivatives, nitropyridine derivatives, etc.

[0156]

[0157] In reaction formulas (1) and (2), X is a leaving group; R 1 The definition of m and the R in equation (IV) (Z1-1) and equation (IV') 1 The definitions of and m are the same; R 2 The definition of r and R in equation (IV-2) 2 The definitions of and r are the same, and will not be repeated here.

[0158] The execution of reactions (1) and (2) is not particularly limited and can be carried out in the presence of a base. Furthermore, the base used is not particularly limited as long as the target product can be synthesized; examples include inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, and sodium hydride; and organic bases such as pyridine, dimethylaminopyridine, trimethylamine, triethylamine, and tributylamine. Depending on the circumstances, the yield can be increased by using a palladium catalyst or a copper catalyst in combination. Specific examples of palladium catalysts include, but are not limited to, palladium dibenzylideneacetone [bis(dibenzylideneacetone)palladium], tris(dibenzylideneacetone)dipalladium [tris(dibenzylideneacetone)dipalladium], and 1,1'-bis(diphenylphosphino)ferrocene dichloropalladium(II)}. The reaction solvent used in reactions (1) and (2) can be a self-polar aprotic solvent, such as acetonitrile, dimethylformamide (DMF), acetone, or dimethylacetamide (DMAc). From the viewpoint of ease of synthesis, the base is preferably potassium carbonate.

[0159] The reaction temperature of the reaction formula (1) or the reaction formula (2) can be set appropriately according to the reaction method. Preferably, the reaction temperature of the reaction formula (1) or the reaction formula (2) is -20℃ to 250℃, and more preferably, the reaction temperature of the reaction formula (1) or the reaction formula (2) is 0℃ to 200℃.

[0160] Next, as shown in reaction formula (3) below, the nitro group in the product of reaction formula (1) (i.e., the intermediate product "dinitro compound") is converted to an amino group by reduction to obtain the final product "diamine compound". The following is only an example, but the present invention is not limited thereto.

[0161]

[0162] Similarly, as shown in reaction formula (4) below, the nitro group in the product of reaction formula (2) (i.e., the intermediate product "dinitro compound") can also be converted into an amino group by reduction to obtain the final product "diamine compound". The following is only an example, but the present invention is not limited thereto.

[0163]

[0164] There are no particular limitations on the reduction methods for dinitro compounds. Examples include using palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, and platinum sulfided on carbon (PtS / C) catalysts as catalysts, and reducing them in solvents such as ethyl acetate, toluene, tetrahydrofuran, dioxane, and alcohols using hydrogen, hydrazine, and hydrogen chloride. Alternatively, an autoclave can be used to carry out the reduction reaction under pressure, if necessary. On the other hand, when the substituents of the hydrogen atoms in the substituted benzene ring or saturated hydrocarbon group contain unsaturated bonds, the unsaturated bonds may be reduced to saturated bonds when using palladium-carbon or platinum-carbon. Therefore, reduction conditions using transition metals such as reducing iron, tin, or tin chloride as catalysts are preferred.

[0165] The reaction temperatures of reaction formulas (3) and (4) can be appropriately set according to the reaction method. Preferably, the reaction temperatures of reaction formulas (3) and (4) are from -20°C to 200°C. More preferably, the reaction temperatures of reaction formulas (3) and (4) are from 0°C to 150°C.

[0166] When n is 2 or 3, compounds represented by formula (1-1) or formula (2-1) below can be used to replace the dihydroxycyclohexane derivative and the dithiol-cyclohexane derivative, respectively, to obtain the compound represented by formula (IV), Y 11 It is either O or S, and n is 2 or 3.

[0167]

[0168] In equations (1-1) and (2-1), k is 0 or 1; R 1 The definition of m and the R in equation (IV) (Z1-1) and equation (IV') 1 The definitions of and m are the same.

[0169] On the other hand, when Y 11 When the symbol is *-COO- or *-OCO-, the * is bonded to an amino aromatic group, allowing for the appropriate synthesis of diamine compounds using conventional methods. For example, when Y... 11 When the compound is a *-COO- diamine, it can be obtained by esterification of a dihydroxycyclohexane derivative (e.g., 1,4-cyclohexanediol) and a nitroaromatic formaldehyde chloride derivative (e.g., nitrobenzyl chloride), followed by reduction of the nitro group. For example, when Y... 11 When the compound is a diamine of the form *-OCO-, it can be obtained by esterification of a cyclohexane diacyl chloride derivative with a nitroaromatic phenol derivative (e.g., nitrophenol) followed by reduction of the nitro group.

[0170] On the other hand, when A 1 A 2 When the divalent aromatic ring group is different, diamine compounds can be appropriately synthesized using conventional methods. Taking Y as an example... 11 Taking a compound with O or S and n=1 as an example, a commercially available aromatic derivative containing a hydroxyl nitro group is first reacted with a cyclohexane derivative having two leaving groups (X) to obtain a nitro compound containing one leaving group (X). The nitro compound containing one leaving group is then reacted with another aromatic derivative containing a hydroxyl nitro group to obtain a dinitro compound, which is then reduced to obtain a diamine compound.

[0171] In some embodiments of the present invention, based on the total amount of the diamine component (b1) used being 100 moles, the total amount of the diamine compound (b1-2) as shown in formula (IV) used being from 0 to 30 moles, preferably from 5 to 25 moles, and more preferably from 7 to 20 moles.

[0172] [Diamine compound (b1-3)]

[0173] The diamine compound (b1-3) may comprise a diamine compound as shown in formula (B13).

[0174]

[0175] In the aforementioned equation (B13), Z 31 and Z 31' Each can be represented independently as a chain hydrocarbon group or a single bond having 1 to 10 carbon atoms; Z 32 and Z 32' Each can be represented independently as -O-, -S-, -CO-, or -COO-; Z 33 and Z 33' Each independently represents a chain-like hydrocarbon group or single bond with 1 to 10 carbon atoms; Z 31 Z 31' Z 33 and Z 33' Not all rings can be single bonds; ring Z represents an aromatic hydrocarbon ring, a diphenyl ether, or a nitrogen-containing heterocycle; B 1 and B 2 Each independently represents one of the divalent organic groups selected from those shown in formulas (V-1) to (V-16) below, and B 1 With B 2 They do not have the same structure.

[0176]

[0177]

[0178] In equations (V-1) to (V-16), * indicates the bond position; in equation (V-2), B 3 Represents an alkylene group having 1 to 5 carbon atoms or -O-; in the formula (V-14), B 4 It represents a hydrogen atom, methyl group, hydroxyl group, or methoxy group.

[0179] In some embodiments of the present invention, the diamine compound (b1-3) represented by formula (B13) is selected from at least one of the groups consisting of structures represented by formulas (B13-1) and (B13-2).

[0180]

[0181] In equations (B13-1) and (B13-2), Z 31 Z 31' The definition of Z in equation (B13) 31 Z 31' The definition is the same, so it will not be repeated here.

[0182] In some embodiments of the present invention, the diamine compound (b1-3) may include, but is not limited to, compounds represented by formulas (B13-3) to (B13-10). Preferably, the diamine compound (b1-3) includes compounds represented by formula (B13-3), compounds represented by formula (B13-5), or combinations thereof.

[0183]

[0184]

[0185]

[0186] The main synthetic methods of the diamine compounds (b1-3) are described in detail below. The methods described below are only illustrative examples and the present invention is not limited thereto.

[0187] As shown in the following reaction formula (a), the diamine compound (b1-3) is prepared by reducing a dinitro compound to convert the nitro group to an amino group. The diamine compound (B13-3) described in this reaction formula is for illustrative purposes only.

[0188]

[0189] There are no particular limitations on the reduction methods for dinitro compounds. Catalysts such as palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, and platinum sulfided on carbon (PtS / C catalysts) can be used, and reduction can be carried out in solvents such as ethyl acetate, toluene, tetrahydrofuran, dioxane, and alcohols using hydrogen, hydrazine, and hydrogen chloride. Alternatively, an autoclave can be used to carry out the reduction reaction under pressure, if necessary. On the other hand, when the substituents of the hydrogen atoms in the substituted benzene ring or saturated hydrocarbon group contain unsaturated bonds, the unsaturated bonds may be reduced to saturated bonds when using palladium-carbon or platinum-carbon. Therefore, reduction conditions using transition metals such as reducing iron, tin, or tin chloride as catalysts are preferred.

[0190] The reaction temperature of the reaction formula (A) can be appropriately set according to the reaction method. Preferably, the reaction temperature of the reaction formula (A) is from -20°C to 200°C, and more preferably, the reaction temperature of the reaction formula (A) is from 0°C to 150°C.

[0191] In the synthesis of dinitro compounds, as shown in reaction formulas (B) and (C) below, a nitro compound containing a leaving group (X) can be obtained by reacting a commercially available nitrohydroxy aromatic derivative, nitrohydroxypyridine derivative, nitrohydroxypyrimidine derivative, or nitrohydroxydiphenyl ether derivative with an aromatic hydrocarbon ring derivative, diphenyl ether derivative, or nitrogen-containing heterocyclic derivative substituted with a leaving group (X). The nitro compound containing the leaving group (X) is then reacted with another nitrohydroxy aromatic derivative, nitrohydroxypyridine derivative, nitrohydroxypyrimidine derivative, or nitrohydroxydiphenyl ether derivative to obtain the dinitro compound. Preferably, the leaving group (X) can be, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a toluenesulfonate ester, or a methanesulfonate ester.

[0192]

[0193]

[0194] The execution of reactions (B) and (C) is not particularly limited and can be carried out in the presence of a base. Furthermore, the base used is not particularly limited as long as the target product can be synthesized; examples include inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, and sodium hydride; and organic bases such as pyridine, dimethylaminopyridine, trimethylamine, triethylamine, and tributylamine. Depending on the circumstances, the yield can be increased when a palladium catalyst or a copper catalyst is used in combination. Specific examples of palladium catalysts include, but are not limited to, palladium dibenzylacetone [bis(dibenzylideneacetone)palladium], tris(dibenzylideneacetone)dipalladium [tris(dibenzylideneacetone)dipalladium], and 1,1'-bis(diphenylphosphino)ferrocene dichloropalladium(II)}. The reaction solvents used in reactions (b) and (c) can be polar aprotic solvents, such as acetonitrile, dimethylformamide (DMF), acetone, or dimethylacetamide (DMAc). From the viewpoint of ease of synthesis, the base is preferably potassium carbonate.

[0195] The reaction temperatures of reaction formula (B) and reaction formula (C) can be appropriately set according to the reaction method. Preferably, the reaction temperatures of reaction formula (B) and reaction formula (C) are from -20°C to 250°C, and more preferably, the reaction temperatures of reaction formula (B) and reaction formula (C) are from 0°C to 200°C.

[0196] The diamine compounds (b1-3) can be used alone or in combination.

[0197] When the diamine component (b1) further comprises the diamine compound (b1-3), the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent has a lower intra-pixel contrast variation.

[0198] In some embodiments of the present invention, based on a total usage of 100 moles of the diamine component (b1), the usage of the diamine compound (b1-3) is from 0 to 94 moles, preferably from 15 to 89 moles, and more preferably from 20 to 86 moles.

[0199] [Diamine compound (b1-4)]

[0200] The diamine compound (b1-4) is a diamine compound as shown in formulas (A22-1) to (A22-2).

[0201]

[0202] In the aforementioned formula (A22-1), Y 31 The divalent organic group represented by formula (A22-3), and multiple Y 32 Each of the following independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. In the formula (A22-2), multiple Y atoms... 33 The divalent organic groups represented by formula (A22-3') are represented independently.

[0203]

[0204] In the divalent organic groups shown in formula (A22-3), Ar independently represents a divalent benzene ring, biphenyl structure, or naphthalene ring, and the hydrogen atoms of the benzene ring, biphenyl structure, or naphthalene ring may be substituted by monovalent substituents or may not be substituted; Y 31' Representative - (CH2) n -, where n represents an integer from 2 to 18, and -(CH2) n At least one of the -CH2- in - can be replaced by -O-, -C(=O)- or -OC(=O)- or not replaced; p1 represents 0 or 1; "*" represents the bond position.

[0205] In the divalent organic groups represented by formula (A22-3'), Ar' independently represents a divalent benzene ring or biphenyl structure, and the hydrogen atoms of the benzene ring or biphenyl structure may be substituted by monovalent substituents or remain unsubstituted; Y 33' Representative - (CH2) n -, where n represents an integer from 2 to 18, and -(CH2) n At least one of the -CH2- in - can be replaced by -O-, -C(=O)- or -OC(=O)- or not replaced; p2 represents 0 or 1; "*" represents the bond position.

[0206] In the divalent organic groups shown in formula (A22-3) and the divalent organic groups shown in formula (A22-3'), the monovalent substituents of the benzene ring, biphenyl structure, or naphthyl ring are, for example, halogens, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, fluoroalkyl groups having 1 to 10 carbon atoms, fluoroalkenyl groups having 2 to 10 carbon atoms, fluoroalkoxy groups having 1 to 10 carbon atoms, carboxyl groups, hydroxyl groups, alkoxycarbonyl groups having 1 to 10 carbon atoms, cyano groups, or nitro groups, etc.

[0207] In some embodiments of the present invention, from the viewpoint of improving liquid crystal alignment, it is preferred that the divalent organic group represented by formula (A22-3) is at least one of the groups represented by formulas (A22-3-1) to (A22-3-16), wherein "*" represents a bonding position.

[0208]

[0209]

[0210] In equation (A22-3-1), m is 0 to 1, and n is 1 to 6. In equation (A22-3-2), n is 1 to 6. In equation (A22-3-3), n is 2 to 6. In equation (A22-3-4), n is 1 to 6. In equation (A22-3-5), n is 1 to 6. In equation (A22-3-6), n is 2 to 6. In equation (A22-3-7), n is 1 to 6. In equation (A22-3-8), n is 1 to 6. In equation (A22-3-9), n is 2 to 6. In equation (A22-3-10), m is 1 to 3, and n is 1 to 4. In equation (A22-3-11), n ​​is 1 to 6. In equation (A22-3-12), n is 1 to 6. In equation (A22-3-13), m is 0 to 1, and n is 1 to 6. In equation (A22-3-14), m is 1 to 3, and n is 1 to 4.

[0211] In some embodiments of the present invention, from the viewpoint of improving liquid crystal alignment, it is preferred that the divalent organic group represented by formula (A22-3') is the group represented by formula (A22-3-7) to formula (A22-3-16).

[0212] When the diamine compound (b1-4) comprises a plurality of diamine compounds represented by formula (A22-1), preferably, Y in formula (A22-1) 31 The diamine compounds of formulas (A22-3-1) to (A22-3-14) and Y in formula (A22-1) 31 The combination of diamine compounds of formula (A22-3-15) to (A22-3-16) is represented.

[0213] In some embodiments of the present invention, the diamine compound represented by formula (A22-2) is, for example, but not limited to, the diamine compounds represented by formulas (A22-2-1) to (A22-2-5).

[0214]

[0215] In equation (A22-2-1), m is 1 to 6, and n is 1 to 6. In equation (A22-2-2), m is 1 to 6, and n is 1 to 6. In equation (A22-2-3), m is 2 to 6, and n is 2 to 6.

[0216] The diamine compounds (b1-4) can be used alone or in combination. In some embodiments of the invention, based on a total usage of 100 moles of the diamine component (b1), the usage of the diamine compounds (b1-4) can be from 0 to 94 moles, preferably from 10 to 89 moles, and more preferably from 15 to 86 moles.

[0217] [Other diamine compounds (b1-5)]

[0218] The other diamine compounds (b1-5) include, but are not limited to, diamine compounds having photoalignment groups, 4-amino-N-methylphenethylamine, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, diamine compounds having carboxyl groups, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4 Diamine ketone, 1,4-bis(4-aminobenzyl)benzene, 4,4'-diaminodiphenyl ether, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-dihydroindene-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, diamine compounds with urea bonds, diamine compounds with amide bonds, diamine compounds with photopolymerizable groups at the end, diamine compounds with siloxane bonds, or diamine compounds with an oxazoline structure, etc.

[0219] The diamine compounds having photoalignment groups are, for example, but not limited to, 4,4'-diaminoazobenzene, or diamine compounds of formulas (A24-1) to (A24-3).

[0220]

[0221] The diamine compounds having a carboxyl group are, for example but not limited to, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, or diamine compounds of formulas (A24-4) to (A24-7).

[0222]

[0223]

[0224] In the aforementioned formula (A24-4), Y 51 The following represent single bonds: -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)-, or -N(CH3)CO-; m1 and m2 independently represent integers from 0 to 4, and (m1+m2) represents integers from 1 to 4. In the above formula (A24-5), m3 and m4 independently represent integers from 1 to 5. In the above formula (A24-6), Y 52 This indicates a straight-chain or branched alkyl group having 1 to 5 carbon atoms; m5 represents an integer from 1 to 5. In the formula (A24-7), Y 53 and Y 54 Each of these can be represented independently as a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)-, or -N(CH3)CO-; m6 represents an integer from 1 to 4.

[0225] The diamine compounds having urea bonds are, for example, but not limited to, the diamine compounds shown in formulas (A24-8) to (A24-10).

[0226]

[0227] In equation (A24-8), n1 is 0 to 6, and n2 is 1 to 6. In equation (A24-9), n1 is 1 to 6, and n2 is 1 to 6. In equation (A24-10), n is 1 to 6.

[0228] The diamine compounds having amide bonds are, for example, but not limited to, the diamine compounds having amide bonds shown in formulas (A24-11) to (A24-13).

[0229]

[0230] In equation (A24-12), n is 1 to 6. In equation (A24-13), n1 is 1 to 6, and n2 is 1 to 6.

[0231] The diamine compound with a photopolymerizable group at the end is, for example, but not limited to, 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallyl aniline.

[0232] The diamine compounds having siloxane bonds are, for example, but not limited to, 3-bis(3-aminopropyl)-tetramethyldisiloxane.

[0233] The diamine compounds having an oxazoline structure are, for example, but not limited to, the diamine compounds shown in formulas (A24-14) to (A24-15).

[0234]

[0235] The other diamine compounds (b1-5) may be used alone or in combination. In some embodiments of the invention, based on a total usage of 100 moles of the diamine component (b1), the usage of the other diamine compounds (b1-5) may be from 0 to 94 moles, preferably from 10 to 89 moles, and more preferably from 15 to 86 moles.

[0236] <Second Polymer (A2)>

[0237] In some embodiments of the present invention, the polymer component (A) further includes a second polymer (A2).

[0238] The second polymer (A2) is selected from at least one of the group consisting of a polyimide precursor formed by reacting a reaction composition comprising a tetracarboxylic dianhydride component (a2) and a diamine component (b2) and an imidized polymer formed from the polyimide precursor, and the second polymer (A2) does not contain the structure shown in formula (I) of the first polymer (A1). For example, the second polymer (A2) is a polyimide precursor having an imide precursor structure of polyamic acid and polyamic ester, or the second polymer (A2) is an imidized polymer (i.e., a polyimide) formed from the polyimide precursor, or the second polymer (A2) comprises the polyimide precursor and the imidized polymer, etc. The second polymer (A2) can be used alone or in combination with other polymers.

[0239] In some embodiments of the present invention, the weight ratio of the first polymer (A1) to the second polymer (A2) (i.e., the mass ratio of the first polymer (A1) to the second polymer (A2)) is 10 / 90 to 90 / 10. Preferably, the weight ratio of the first polymer (A1) to the second polymer (A2) is 20 / 80 to 90 / 10. More preferably, the weight ratio of the first polymer (A1) to the second polymer (A2) is 20 / 80 to 80 / 20.

[0240] [Tetracarboxylic acid dianhydride component (a2)]

[0241] The tetracarboxylic dianhydride component (a2) is, for example, but not limited to, acyclic aliphatic tetracarboxylic dianhydride compounds, alicyclic tetracarboxylic dianhydride compounds, aromatic tetracarboxylic dianhydride compounds, or derivatives of these compounds. The acyclic aliphatic tetracarboxylic dianhydride compounds, the alicyclic tetracarboxylic dianhydride compounds, and the aromatic tetracarboxylic dianhydride compounds are, for example, tetracarboxylic dianhydride compounds in the first polymer (A1). Preferably, the tetracarboxylic dianhydride component (a2) comprises an alicyclic tetracarboxylic dianhydride or a derivative thereof as shown in formula (A11), or as shown in formula (A12) above and X 1' Tetracarboxylic dianhydride compounds or derivatives thereof with structures represented by formulas (A12-1) to (A12-6). The tetracarboxylic dianhydride component (a2) may be used alone or in combination.

[0242] In some embodiments of the present invention, preferably, the tetracarboxylic acid dianhydride component (a2) comprises the components shown in formula (A12) and X 1' It is a tetracarboxylic acid dianhydride compound (a2-1) with the structure shown in formula (VI).

[0243]

[0244] In equation (VI), Z 11 This indicates a single bond, and "*" represents the bond position.

[0245] The tetracarboxylic acid dianhydride compound (a2-1) can be used alone or in combination.

[0246] In some embodiments of the present invention, more preferably, the tetracarboxylic dianhydride component (a2) comprises a tetracarboxylic dianhydride compound as shown in formula (VII).

[0247]

[0248] In some embodiments of the present invention, based on a total amount of 100 moles of the tetracarboxylic dianhydride component (a2), the amount of the tetracarboxylic dianhydride compound (a2-1) used is 30 to 100 moles, preferably 40 to 100 moles, and more preferably 50 to 100 moles.

[0249] [Diamine component (b2)]

[0250] The diamine component (b2) is, for example, but not limited to, the diamine component (b1) of the first polymer (A1), or a diamine compound (b2-1) having a nitrogen-containing structure. The diamine component (b2) may be used alone or in combination. Furthermore, the diamine component (b2) does not contain the diamine compound (b1-1) shown in formula (III), the diamine compound (b1-2) shown in formula (IV), or the diamine compound (b1-3).

[0251] [Diamine compounds containing nitrogen atoms (b2-1)]

[0252] The nitrogen-containing structure of the diamine compound (b2-1) having a nitrogen-containing structure is selected from at least one of the group consisting of nitrogen-containing heterocycles, secondary amine groups and tertiary amine groups.

[0253] The nitrogen-containing heterocycles of the diamine compound (b2-1) having a nitrogen-containing atomic structure include, but are not limited to, pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, etc. The nitrogen-containing heterocycle is preferably a pyridine, pyrimidine, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, or hexamethyleneimine.

[0254] The nitrogen-containing structure of the diamine compound (b2-1) with nitrogen-containing atomic structure is a secondary amine group and a tertiary amine group as shown in formula (B21).

[0255]

[0256] In the formula (B21), Z represents hydrogen, alkyl, cycloalkyl or aryl with 1 to 10 carbon atoms; "*" represents the bond position.

[0257] The alkyl group having 1 to 10 carbon atoms is, for example, but not limited to, methyl, ethyl, or propyl. The cycloalkyl group is, for example, but not limited to, cyclohexyl. The aryl group is, for example, but not limited to, phenyl or tolyl. Preferably, Z is hydrogen or methyl.

[0258] The diamine compound having a nitrogen-containing structure (b2-1) is, for example, but not limited to, 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, diamine compounds of formulas (B21-1) to (B21-8), or diamine compounds of formulas (B21-9) to (B21-26).

[0259]

[0260]

[0261]

[0262]

[0263] In formula (B21-5), n represents 1 to 4. In formula (B21-6), n represents 1 to 4. The diamine compound (b2-1) having a nitrogen-containing structure can be used alone or in combination.

[0264] In some embodiments of the present invention, based on a total amount of 100 moles of the diamine component (b2), the amount of the diamine compound (b2-1) having a nitrogen-containing structure used is from 15 moles to 100 moles, preferably from 20 moles to 90 moles, and more preferably from 25 moles to 80 moles.

[0265] Preparation methods of the first polymer (A1) and the second polymer (A2)

[0266] The first polymer (A1) and the second polymer (A2) can be manufactured by reacting the diamine component and the tetracarboxylic dianhydride component described above in a solvent (condensation polymerization). When a portion of the first polymer (A1) and the second polymer (A2) has an amide acid structure, for example, by reacting the tetracarboxylic dianhydride component with the diamine component, a polymer with an amide acid structure (i.e., polyamic acid) can be obtained. The solvent is not particularly limited, as long as it can dissolve the formed polymer. For example, the solvent is, but is not limited to, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or 1,3-dimethyl-2-imidazolidineone. In some embodiments of the present invention, when the solvent solubility of the polymer is high, the solvent is, for example, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents as shown in formulas (D-1) to (D-3).

[0267]

[0268] HOCH2-CH2-OZ 2 Formula (D-2)

[0269] HOCH2-CH2-OCH2-CH2-OZ 3Equation (D-3)

[0270] In the aforementioned equation (D-1), Z 1 This indicates an alkyl group having 1 to 3 carbon atoms. In formula (D-2), Z 2 This indicates an alkyl group having 1 to 3 carbon atoms. In formula (D-3), Z 3 This refers to alkyl groups having 1 to 4 carbon atoms.

[0271] The solvent can be used alone or in combination. Furthermore, even solvents that cannot dissolve the polymer can be mixed with the aforementioned solvents within a range that will not cause the resulting polymer to precipitate. When the diamine component and the tetracarboxylic dianhydride component react in the solvent, the reaction can proceed at any concentration. Preferably, the total concentration of the diamine component and the tetracarboxylic dianhydride component in the reaction is 1 wt% to 50 wt%, more preferably, the total concentration of the diamine component and the tetracarboxylic dianhydride component in the reaction is 5 wt% to 30 wt%. The reaction can also be initially carried out at a high concentration, and then additional solvent is added. During the reaction, preferably, the ratio of the total moles of the diamine component to the total moles of the tetracarboxylic dianhydride component is 0.8 to 1.2. Similar to general polycondensation reactions, the closer the ratio of the total moles of the diamine component to the total moles of the tetracarboxylic dianhydride component is to 1.0, the larger the molecular weight of the first polymer (A1) or the second polymer (A2) formed.

[0272] The polymer having an amide ester structure can be obtained, for example, by conventional methods, and the conventional methods are (1) reacting the polyamic acid obtained by the above methods with an esterifying agent, (2) reacting a tetracarboxylic acid diester compound with a diamine compound, or (3) reacting a tetracarboxylic acid diester dihalide with a diamine compound.

[0273] The imidized polymer in the first polymer (A1) or the second polymer (A2) of the liquid crystal alignment agent of the present invention can be obtained, for example, by cyclizing the polymer having an amide ester structure. In the imidized polymer, the cyclization rate (also called the imidization rate) of the functional groups of the amide acid group or its derivatives is not necessarily 100%, and the imidization rate of the imidized polymer can be arbitrarily adjusted according to the application and / or purpose.

[0274] Methods for obtaining the imidized polymer include, for example, thermal imidization by directly heating a solution containing a polymer having an amide ester structure, or catalytic imidization by adding a catalyst to the solution containing the polymer having an amide ester structure. When performing thermal imidization in the solution containing the polymer having an amide ester structure, preferably, the temperature of the thermal imidization is between 100°C and 400°C, more preferably, the temperature of the thermal imidization is between 120°C and 250°C. Preferably, during the thermal imidization, water generated by the imidization reaction is also removed from the system.

[0275] The catalytic imidization is carried out, for example, by adding a basic catalyst and an acid anhydride to a solution containing the polymer having an ammonium ester structure, preferably by stirring at -20°C to 250°C, more preferably at 0°C to 180°C. Preferably, the amount of the basic catalyst added is 0.5 to 30 times the molar equivalent of the ammonium acid group, more preferably, 2 to 20 times the molar equivalent of the ammonium acid group. Preferably, the amount of the acid anhydride added is 1 to 50 times the molar equivalent of the ammonium acid group, more preferably, 3 to 30 times the molar equivalent of the ammonium acid group. The basic catalyst is, for example, but not limited to, pyridine, triethylamine, trimethylamine, tributylamine, or trioctylamine. Pyridine is preferred because it has a moderately basic nature that allows the reaction to proceed. The acid anhydride is, for example, but not limited to, acetic anhydride, trimellitic anhydride, or phenylmethyltetrahydroquinone. When acetic anhydride is used, purification after the reaction is easier, so it is preferred. The imidization rate of the catalyst can be controlled by adjusting the amount of catalyst, reaction temperature, and / or reaction time.

[0276] When recovering the imidized polymer formed from the above-mentioned imidization reaction solution, the reaction solution is added to a solvent and allowed to precipitate. Solvents used for precipitation include, but are not limited to, methanol, ethanol, isopropanol, acetone, hexane, butyl cellol, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, or water. After filtering and recovering the polymer precipitated in the solvent, it can be dried at room temperature or under normal or reduced pressure. Alternatively, the polymer recovered from precipitation can be dissolved in a solvent and reprecipitated; this operation can be repeated 2 to 10 times to reduce impurities in the polymer. Solvents used can be, for example, alcohols or ketone hydrocarbons. Using three or more of the selected solvents can further improve the purification efficiency, making it ideal.

[0277] Solution Viscosity and Molecular Weight of Polymers

[0278] When preparing a solution containing 10 wt% to 15 wt% of a first polymer (A1) or a second polymer (A2), the viscosity of the solution containing the first polymer (A1) or the second polymer (A2) is not particularly limited in this invention. For ease of operation, the viscosity of the solution containing the first polymer (A1) or the second polymer (A2) can be, for example, from 10 mPa·s to 1000 mPa·s. The viscosity (mPa·s) of the polymer-containing solution is the value measured at 25°C using a rotational viscometer, after preparing a solution containing 10 wt% to 15 wt% of the polymer using a good solvent for the polymer (e.g., γ-butyrolactone or N-methyl-2-pyrrolidone).

[0279] In some embodiments of the present invention, preferably, the weight-average molecular weight (Mw) of the first polymer (A1) or the second polymer (A2) of the present invention, as measured by gel permeation chromatography (GPC) based on polystyrene, is between 1,000 and 500,000, more preferably, between 2,000 and 500,000. Secondly, preferably, the molecular weight distribution (Mw / Mn) expressed as the ratio of Mw to the number-average molecular weight (Mn) of polystyrene measured by GPC is 15 or less, more preferably, 10 or less. When the molecular weight of the polymer is within the above-mentioned range, good alignment and stability of the liquid crystal display element can be ensured.

[0280] End-capping agent

[0281] In some embodiments of the present invention, when synthesizing the first polymer (A1) or the second polymer (A2) of the present invention, the tetracarboxylic acid dianhydride component and the diamine component as described above can be used, and an end-sealing polymer can be synthesized using a suitable end-sealing agent. The end-sealing polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by coating, and improving the adhesion properties of the sealant and the liquid crystal alignment film. The ends of the first polymer (A1) or the second polymer (A2) of the present invention can be, for example, amino groups, carboxyl groups, anhydride groups, or derivatives of the above groups. Amino groups, carboxyl groups, anhydride groups, or derivatives of the above groups can be obtained by a general condensation reaction, or by sealing the ends using the end-sealing agent described below. Similarly, the above derivatives can be obtained, for example, using the end-sealing agent described below.

[0282] The capping agent is, for example, but not limited to, acid anhydrides, dicarbonate ester compounds, chlorocarbonyl compounds, monoamine compounds, or monoisocyanate compounds. The acid anhydrides are, for example, but not limited to, acetic anhydride, maleic anhydride, nerate 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, or 4-ethynylphthalic anhydride. The dicarbonate ester compounds are, for example, but not limited to, di-tert-butyl dicarbonate or diallyl dicarbonate. The chlorocarbonyl compounds are, for example, but not limited to, acryloyl chloride, methacryloyl chloride, or nicotinic chloride. The monoamine compounds include, but are not limited to, aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, or n-octylamine. The monoisocyanate compounds include, but are not limited to, ethyl isocyanate, phenyl isocyanate, or naphthyl isocyanate.

[0283] The capping agent can be used alone or in combination. In some embodiments of the invention, preferably, based on a total amount of 100 moles of the diamine component, the amount of the capping agent used is from 0.01 moles to 20 moles, more preferably, the amount of the capping agent used is from 0.01 moles to 10 moles.

[0284] Other Polymers

[0285] In some embodiments of the present invention, the polymer component (A) of the liquid crystal alignment agent of the present invention may optionally also include other polymers. These other polymers are, for example, but not limited to, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene or derivatives thereof, poly(styrene-phenylmaleimide) derivatives, or poly(meth)acrylates, etc.

[0286] Solvent (B)

[0287] From the viewpoint of forming a uniform thin film, the liquid crystal alignment agent is taken in the form of a coating liquid to produce a liquid crystal alignment film. Preferably, the liquid crystal alignment agent of the present invention is a coating liquid containing a polymer component (A) and a solvent (B). The concentration of the polymer component (A) in the liquid crystal alignment agent can be appropriately varied depending on the desired coating thickness. From the viewpoint of forming a uniform and defect-free coating film, the concentration of the polymer component (A) in the liquid crystal alignment agent is preferably 1 wt% or more. From the viewpoint of the storage stability of the solution, the concentration of the polymer component (A) in the liquid crystal alignment agent is preferably 10 wt% or less. Ideally, the concentration of the polymer component (A) is 2 wt% to 8 wt%. The content of the polymer component (A) in the liquid crystal alignment agent can be appropriately varied by the coating method of the liquid crystal alignment agent and / or the desired film thickness of the liquid crystal alignment film. Preferably, the content of the polymer component (A) is 2 wt% to 10 wt%, more preferably, the content of the polymer component (A) is 3 wt% to 8 wt%.

[0288] The solvent (B) in the liquid crystal alignment agent is, for example, an organic solvent, and there are no particular limitations on the solvent (B), as long as it can uniformly dissolve the polymer component (A). The solvent (B) includes, but is not limited to, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactic acid, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidineone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide. Amines, 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, or N-cyclohexyl-2-pyrrolidone, etc., are all considered good solvents. N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, or γ-butyrolactone are preferred. In some embodiments of the present invention, based on the total amount of solvent (B) in the liquid crystal alignment agent being 100 wt%, the amount of the good solvent used is 20 wt% to 99 wt%, preferably, the amount of the good solvent used is 20 wt% to 90 wt%, and more preferably, the amount of the good solvent used is 30 wt% to 80 wt%.

[0289] In some embodiments of the present invention, preferably, the solvent (B) in the liquid crystal alignment agent comprises the aforementioned good solvent and a poor solvent that can improve the coatability and surface smoothness of the coating film during liquid crystal alignment agent coating. Preferably, based on the total amount of solvent (B) in the liquid crystal alignment agent being 100 wt%, the amount of the poor solvent used is 1 wt% to 80 wt%, more preferably, the amount of the poor solvent used is 10 wt% to 80 wt%, and even more preferably, the amount of the poor solvent used is 20 wt% to 70 wt%. The type and amount of the poor solvent can be appropriately selected according to the coating apparatus, coating conditions, and / or coating environment of the liquid crystal alignment agent.

[0290] The undesirable solvents mentioned include, but are not limited to, 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-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, and 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 monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, or diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0291] In some embodiments of the present invention, preferably, the undesirable solvent is diisobutyl methanol, 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, etc.

[0292] In some embodiments of the present invention, preferably, the solvent combination of the good solvent and the poor solvent is, for example, but not limited to, 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-dimethyllacticamide and diisobutyl ketone; N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate. N-methyl-2-pyrrolidone with ethylene glycol monobutyl ether acetate; N-ethyl-2-pyrrolidone with dipropylene glycol dimethyl ether; N,N-dimethyl lactamide with ethylene glycol monobutyl ether; N,N-dimethyl lactamide with propylene glycol diacetate; N-ethyl-2-pyrrolidone with diethylene glycol diethyl ether; N,N-dimethyl lactamide with diethylene glycol diethyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone with diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone with propylene glycol monobutyl ether; N-methyl 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 propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate; 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 with 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, 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; or N-ethyl-2-pyrrolidone, N,N-dimethyllactic acid and diisobutyl ketone, etc.

[0293] The solvent (B) can be used alone or in combination with other solvents. In some embodiments of the invention, based on a total amount of 100 parts by weight of the polymer component (A), the amount of solvent (B) used is 800 to 4000 parts by weight, preferably 900 to 3500 parts by weight, and more preferably 1000 to 3000 parts by weight.

[0294] Compound (C)

[0295] The compound (C) comprises the structure shown in formula (C1).

[0296]

[0297] In the formula (C1), A is a monovalent to tetravalent organic group; n is an integer from 1 to 4; L 1 L 2 Each is independently an alkylene group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms; R 3 R 4 Each can be represented independently as shown in equation (C2).

[0298]

[0299] In the above formula (C2), R 5 It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

[0300] In this specification, alkyl is a monovalent functional group derived from an alkane and can be a straight-chain alkyl or a branched alkyl. The number of carbon atoms in the straight-chain alkyl is not particularly limited, but preferably, the number of carbon atoms in the straight-chain alkyl is 1 to 20. Conversely, the number of carbon atoms in the branched alkyl is 3 to 20. The alkyl group includes, but is not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, n-octyl, tert-octyl, 1-methylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, 2,6-dimethylheptyl-4-yl, etc.

[0301] In this specification, aryl is a monovalent functional group derived from aromatic hydrocarbons, and there are no particular limitations. Preferably, the aryl group has 6 to 20 carbon atoms and can be a monocyclic or polycyclic aryl group. Monocyclic aryl groups include, but are not limited to, phenyl, biphenyl, and terphenyl. Polycyclic aryl groups include, but are not limited to, naphthyl, anthraceneyl, phenanthryl, pyrenyl, perylenyl, chrysenyl, and fluorenyl groups.

[0302] In this specification, a haloalkyl group refers to a functional group on an alkyl group in which a hydrogen atom is replaced by a halogen, as described above, and the halogen is, for example, but not limited to, fluorine, chlorine, bromine, and iodine. In some embodiments of the invention, preferably, the haloalkyl group has 1 to 20 carbon atoms.

[0303] In this specification, alkylene is a divalent functional group derived from an alkane, and the description of alkyl as described above can be used, except that they are divalent functional groups. The alkylene can be a straight-chain alkylene or a branched alkylene. Examples of alkylene include, but are not limited to, methylene, ethylene, propylene, isobutylene, dibutylene, tert-butylene, pentylene, and hexylene.

[0304] In this specification, arylene is a divalent functional group derived from aromatic hydrocarbons, and the description of aryl groups described above can be applied, except that they are divalent functional groups. The arylene can be a straight-chain arylene or a branched arylene. Examples of arylene include, but are not limited to, phenylene, biphenylene, terphenylene, etc.

[0305] In this specification, a multivalent organic group refers to a residue in which multiple hydrogen atoms bonded to any compound have been removed, such as a divalent, trivalent, or tetravalent organic group. For example, a tetravalent organic group derived from cyclobutane refers to a residue in which any four hydrogen atoms bonded to cyclobutane have been removed.

[0306] In formula (C1), A is a monovalent to tetravalent organic group, and n can be an integer from 1 to 4. A is an organic group located at the center of the compound, and the n functional groups represented by brackets "[]" in formula (C1) can be bonded to the terminal functional group contained in A. That is, in formula (C1), if n is 1, then A is a monovalent organic group. Furthermore, when n is 2, A is a divalent organic group. Furthermore, when n is 3, A is a trivalent organic group. Furthermore, when n is 4, A is a tetravalent organic group. In some embodiments of the present invention, preferably, in formula (C1), n ​​is 2, and A is an alkylene group having 1 to 10 carbon atoms, specifically a butylene group.

[0307] In the aforementioned formula (C1), the L 1 and the L 2 The terms may be the same or different, and each independently represents one of an alkylene group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. In some embodiments of the invention, preferably, the L... 1 and the L 2 They are the same alkylene groups with 1 to 5 carbon atoms, such as methylene and ethylene.

[0308] In the aforementioned formula (C1), R 3 and the R 4 As a functional group that replaces the terminal hydrogen atom of the hydroxyl group (-OH), and since the hydroxyl group (-OH) is a crosslinkable functional group of the compound, the R... 3 and the R 4 It can be used to inhibit the crosslinking reaction between polyimide or polyimide precursor and the formula (C1).

[0309] As described below, when the temperature is raised to 90°C or higher through drying, exposure, curing, or other processes used to prepare a liquid crystal alignment agent into a liquid crystal alignment film, the R... 3 and the R 4 It can be desorbed from the formula (C1) and simultaneously replaced by hydrogen atoms.

[0310] The R 3 and the R 4 They can be the same or different from each other, and each can be an independent functional group represented by the above formula (C2).

[0311] In some embodiments of the present invention, in order to make the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent have lower rubbing points, preferably, in formula (C2), the R 5 It is an alkyl group having 3 to 10 carbon atoms or a haloalkyl group having 10 to 15 carbon atoms.

[0312] In some embodiments of the present invention, preferably, the R in formula (C2) 5 It is one of n-butyl, tert-butyl, and 2,6-dimethylheptyl-4-yl.

[0313] In some embodiments of the present invention, in order to make the liquid crystal display element comprising the liquid crystal alignment film formed by the liquid crystal alignment agent have lower rubbing points, preferably, in the formula (C1), n ​​is an integer from 2 to 4.

[0314] In some embodiments of the present invention, in formula (C1), A is an alkylene group having 1 to 10 carbon atoms, and n is 2. That is, formula (C1) is a compound with the structure shown in formula (C3), thereby enabling the liquid crystal display element comprising a liquid crystal alignment film formed by the liquid crystal alignment agent to have lower scuffing points.

[0315]

[0316] In the formula (C3), A' is an alkylene group having 1 to 10 carbon atoms, L 1 'To L 4 Each is independently an alkylene group having 1 to 5 carbon atoms, R 3 'To R 6 Each can be represented independently as shown in equation (C4).

[0317]

[0318] In the aforementioned formula (C4), R 5 It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

[0319] Specific examples of compounds with the structure shown in formula (C1) can be listed as compounds represented by formulas (C1-1) to (C1-3). In some embodiments of the present invention, preferably, the compound with the structure shown in formula (C1) is the compound represented by formula (C1-1).

[0320]

[0321] In some embodiments of the present invention, based on a total amount of 100 wt% of the liquid crystal alignment agent, the amount of compound (C) is 1 wt% to 30 wt%, preferably 2 wt% to 25 wt%, and more preferably 3 wt% to 20 wt%.

[0322] When the compound (C) is not used, the liquid crystal display element containing the liquid crystal alignment film formed by the liquid crystal alignment agent has high intra-pixel contrast variation and scuffing spots, resulting in poor display quality of the liquid crystal display element.

[0323] Additive Ingredients

[0324] In some embodiments of the present invention, the liquid crystal alignment agent further comprises additive components. These additive components include, but are not limited to, adhesion promoters for improving the adhesion between the liquid crystal alignment film and the substrate or between the liquid crystal alignment film and the sealant; crosslinking compounds for improving the strength of the liquid crystal alignment film; compounds for promoting imidization; and dielectric or conductive materials for adjusting the dielectric constant or resistance of the liquid crystal alignment film.

[0325] <Sealing Agent>

[0326] The sealing aids include, but are not limited to, 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, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, vinyltrimethoxysilane, etc. Silane coupling agents such as methyl silane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, or 3-isocyanatepropyltriethoxysilane. When using the aforementioned binding agent, based on the viewpoint of exhibiting good resistance to AC image retention, it is preferable that the amount of the binding agent used is from 0.1 to 30 parts by weight relative to 100 parts by weight of the total amount of polymer component (A) in the liquid crystal alignment agent, and more preferably, the amount of the binding agent used is from 0.1 to 20 parts by weight.

[0327] <Cross-linked compounds>

[0328] Based on the viewpoint of exhibiting good resistance to AC image retention and effectively improving film strength, the crosslinking compound may be a compound having ethylene oxide, propylene oxide, at least one group selected from the group consisting of the group shown in formula (E1) and the group shown in formula (E2), or a compound selected from the compound shown in formula (E3).

[0329]

[0330] In the aforementioned formula (E1), G 1 and G 2 Each of these independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or -CH2-OH. In the formula (E2), G 3 This indicates an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms. G 4 This represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms. In formula (E3), G 5 This indicates an organic group with a (g1+g2) valence containing an aromatic ring. G 6 This indicates a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. g1 represents an integer from 1 to 6, and g2 represents an integer from 0 to 4.

[0331] In the aforementioned formula (E3), G 5 The (g1+g2) valence organic groups representing aromatic rings can be exemplified by (g1+g2) valence aromatic hydrocarbon groups having 6 to 30 carbon atoms, (g1+g2) valence organic groups formed by direct or interleaved linkages of aromatic hydrocarbon groups having 6 to 30 carbon atoms, or (g1+g2) valence groups having aromatic heterocycles. The aromatic hydrocarbons can be, for example, benzene or naphthalene. The aromatic heterocycles can be exemplified by the specific nitrogen-containing structures described above. The linkages can be exemplified by alkylene groups having 1 to 10 carbon atoms or groups from which one hydrogen atom is removed, or divalent or trivalent cyclohexane, etc. Any hydrogen atom of the alkylene group can also be replaced by a fluorine atom or an organic group such as trifluoromethyl. In the formula (E3), G 6 The alkyl groups represented by carbons from 1 to 5 can be methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, or n-pentyl.

[0332] [Compounds containing ethylene oxide]

[0333] Specific examples of the ethylene oxide-containing compounds include N,N,N',N'-tetracyclooxypropylmethylenediamine, 1,3-bis(N,N-dicyclooxypropylaminomethyl)cyclohexane, N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetracyclooxypropyl-p-phenylenediamine, and compounds containing nitrogen atoms as shown in formulas (E4) to (E6).

[0334]

[0335] [Compounds containing propylene oxide]

[0336] Specific examples of the compounds having an alkylene oxide content can be listed as compounds represented by formulas (E7) to (E16).

[0337]

[0338]

[0339] In equation (E7), n represents 1 to 3. In equation (E13), n represents 1 to 3. In equation (E14), n represents 1 to 100. In equation (E15), R represents... "*" represents the bond position. In the above formula (E16), n represents 1 to 10.

[0340] [Compounds having groups as shown in formula (E1)]

[0341] Specific examples of compounds having groups as shown in formula (E1) can be listed as compounds shown in formulas (E1-1) to (E1-12).

[0342]

[0343]

[0344] [Compounds having groups as shown in formula (E2)]

[0345] Specific examples of compounds having groups as shown in formula (E2) can be listed as compounds shown in formulas (E2-1) to (E2-4).

[0346]

[0347]

[0348] In equation (E2-1), n ​​represents 2 to 16. In equation (E2-2), n represents 2 to 16.

[0349] [Compounds having groups as shown in formula (E3)]

[0350] Specific examples of compounds having groups as shown in formula (E3) are compounds shown in formulas (E3-1) to (E3-10).

[0351]

[0352]

[0353] In some embodiments of the present invention, preferably, based on a total usage of 100 parts by weight of polymer component (A) in the liquid crystal alignment agent, the usage of the crosslinking compound is from 0.5 parts by weight to 20 parts by weight. More preferably, based on the viewpoint of the progress of the crosslinking reaction and good resistance to AC image retention, the usage of the crosslinking compound is from 1 part by weight to 15 parts by weight.

[0354] <Compounds that promote imidization>

[0355] In some embodiments of the present invention, preferably, the compound used to promote imidization is a compound having a basic site [e.g., a primary amino group, an aliphatic heterocycle (such as a pyrrolidine skeleton), an aromatic heterocycle (such as an imidazole ring or an indole ring), or a guanidine group, etc.] (except for the aforementioned crosslinking compounds and binding aids), or a compound that produces the basic site upon calcination. More preferably, the compound used to promote imidization is a compound that produces the basic site upon calcination, and specific examples may be, for example, amino acids in which part or all of the basic site is protected. Specific examples of the aforementioned amino acids include glycine, alanine, cysteine, methionine, asparagine, glutamine, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histamine, lysine, or ornithine. For the purpose of promoting imidization, more preferably, the compound used to promote imidization is N-α-(9-enylomethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine.

[0356] Fabrication Method of Liquid Crystal Alignment Film and Liquid Crystal Display Element

[0357] 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 as a horizontally aligned or vertically aligned (VA type) liquid crystal alignment film, and is suitable as a liquid crystal alignment film for horizontally aligned liquid crystal display elements such as IPS or FFS types. The liquid crystal display element of the present invention includes the liquid crystal alignment film. The liquid crystal display element of the present invention can be manufactured, for example, by the method described in steps (1) to (4) or steps (1) to (2) and (4) below.

[0358] Step (1): Apply liquid crystal alignment agent to the substrate.

[0359] The liquid crystal alignment agent of the present invention is coated on one side of a substrate having a patterned transparent conductive film using a suitable coating method such as roll coating, spin coating, printing, or inkjet coating. The substrate is not particularly limited; it only needs to be a highly transparent substrate, and glass or silicon nitride substrates can be used in combination with plastic substrates such as acrylic or polycarbonate substrates. Furthermore, in reflective liquid crystal display elements, if only a single-sided substrate is used, an opaque material such as a silicon wafer can be used, and the electrodes used can be made of light-reflective materials such as aluminum. Moreover, when manufacturing IPS or FFS type liquid crystal display elements, the comb-type design uses an electrode substrate with a patterned transparent conductive film or metal film and an opposing substrate without electrodes.

[0360] Methods for coating the liquid crystal alignment agent onto a substrate and forming a film include screen printing, offset printing, flexographic printing, inkjet printing, and spray coating. Preferably, the film formation method utilizes inkjet coating.

[0361] Step (2): Calcination of the coated liquid crystal alignment agent

[0362] Step (2) is the calcination of the liquid crystal alignment agent coated on the substrate to form a film. After the liquid crystal alignment agent is coated on the substrate, the solvent can be evaporated by heating means such as a hot plate, a thermally circulating oven, or an infrared oven, or thermal imidization of polyamic acid or polyamic acid ester can be performed. The drying and calcination steps performed after coating the liquid crystal alignment agent can be performed at any temperature and time, and multiple drying or calcination steps can be performed. The temperature of the drying step can be, for example, 40°C to 180°C. From the viewpoint of shortening the processing time, the drying step can be performed at 40°C to 150°C. The time of the drying step is not particularly limited, and it can be, for example, 1 minute to 10 minutes or 1 minute to 5 minutes. When thermal imidization of polyamic acid or polyamic acid ester is performed, after the drying step, a calcination step can be further performed at a temperature of, for example, 150°C to 300°C or 150°C to 250°C. The calcination step is not particularly time-limited, and can be 5 to 40 minutes or 5 to 30 minutes. If the film obtained after the calcination step is too thin, the reliability of the liquid crystal display element will be reduced. Therefore, preferably, the thickness of the film is 5 nm to 300 nm, and more preferably, the thickness of the film is 10 nm to 200 nm.

[0363] Step (3): Perform alignment treatment on the membrane obtained in step (2).

[0364] Step (3) involves performing alignment treatment on the film obtained in step (2), depending on the situation. That is, in horizontally aligned liquid crystal display elements such as IPS or FFS types, alignment treatment is performed on the film to impart alignment capability. On the other hand, in vertically aligned liquid crystal display elements such as VA or PSA types, the formed film can be used directly as a liquid crystal alignment film, but alignment treatment can also be performed on the film to impart alignment capability. Alignment treatment of the liquid crystal alignment film includes, but is not limited to, rubbing treatment or photoalignment treatment; preferably, photoalignment treatment. The photoalignment treatment involves irradiating the surface of the film with radiation that has been deflected in a certain direction, and, depending on the situation, heating it at a temperature of 150°C to 250°C to impart liquid crystal alignment properties (also called liquid crystal alignment capability). The radiation can be ultraviolet or visible light with a wavelength of 100nm to 800nm. Preferably, the radiation is ultraviolet light with a wavelength of 100 nm to 400 nm, and more preferably, the radiation is ultraviolet light with a wavelength of 200 nm to 400 nm.

[0365] The radiation dose can be 1 mJ / cm². 2 Up to 10,000 mJ / cm 2 Preferably, the radiation dose is 100 mJ / cm². 2 Up to 5,000 mJ / cm 2 More preferably, the radiation dose is 100 mJ / cm². 2 Up to 1500mJ / cm 2 Preferably, the radiation dose is 100 mJ / cm². 2 Up to 1000mJ / cm 2 When using a general liquid crystal alignment agent, the light irradiation dose for the alignment treatment is 100 mJ / cm². 2 Up to 5000mJ / cm 2 However, the liquid crystal alignment agent of the present invention can still form a liquid crystal alignment film in which variations (non-uniformity) in the liquid crystal alignment within the film surface are effectively suppressed, even if the light irradiation amount during alignment treatment is reduced. During irradiation, in order to improve liquid crystal alignment, the substrate having the film can be heated at 50°C to 250°C simultaneously with irradiation. The liquid crystal alignment film produced in this manner allows liquid crystal molecules to be stably aligned in a certain direction. Furthermore, the liquid crystal alignment film irradiated with polarized light in the above method can be contacted with a solvent, or the irradiated liquid crystal alignment film can be heat-treated.

[0366] The solvent used in the contact treatment is not particularly limited, as long as it can dissolve the decomposition products generated from the film after radiation irradiation. The solvent used in the contact treatment includes, but is not limited to, 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, or cyclohexyl acetate. From the viewpoint of versatility and safety, it is preferable that the solvent used in the contact treatment is water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate; more preferably, it is water, 1-methoxy-2-propanol, or ethyl lactate. The solvent used in the contact treatment can be used alone or in combination.

[0367] In some embodiments of the present invention, preferably, the temperature for heating the irradiated film is between 50°C and 300°C, more preferably, the temperature for heating is between 120°C and 250°C. Preferably, the heating time is between 1 minute and 30 minutes.

[0368] Step (4): Fabrication of liquid crystal cells

[0369] Prepare two substrates with liquid crystal alignment films formed on their surfaces, and place liquid crystal between the two substrates facing each other. For example, the following two methods can be used. In the first method, firstly, arrange the two substrates facing each other with their liquid crystal alignment films facing each other, separated by a gap (intercellular space). Then, bond the peripheries of the two substrates together with a sealant, and then inject the liquid crystal composition to fill the intercellular space separated by the substrate surfaces and the sealant. After it contacts the film surface, seal the injection hole.

[0370] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant is applied to predetermined positions on one of two substrates on which a liquid crystal alignment film is formed. Then, a liquid crystal composition is dropped onto multiple predetermined positions on the surface of the liquid crystal alignment film. Next, the other substrate is bonded with the liquid crystal alignment films facing each other, pressing the liquid crystal composition against the entire surface of the liquid crystal alignment film, bringing it into contact with the surface of the other liquid crystal alignment film. Then, the entire surface of the substrate is irradiated with UV light to harden the sealant. Preferably, when performing any of the above methods, the liquid crystal composition used is further heated to a temperature at which it becomes isotropic, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal filling. Furthermore, when performing a friction treatment on the film, the two substrates are arranged facing each other at a predetermined angle to the friction direction of each film, for example, orthogonal or antiparallel. The sealant can be, for example, an epoxy resin containing a hardener and alumina spheres as spacers. The liquid crystal composition is, for example, a nematic liquid crystal or a lamellar liquid crystal, preferably a nematic liquid crystal.

[0371] A polarizing plate can be attached to the outer surface of the liquid crystal cell as needed to obtain a liquid crystal display element. The polarizing plate attached to the outer surface of the liquid crystal cell is, for example, a polarizing film that extends and aligns with polyvinyl alcohol while simultaneously absorbing iodine, and is called an "H film". The polarizing plate can be a polarizing plate sandwiched with a cellulose acetate protective film, or a polarizing plate composed of the H film itself.

[0372] The present invention will be further described with reference to the following embodiments, but it should be understood that the embodiments are for illustrative purposes only and should not be construed as limiting the implementation of the present invention.

[0373] [Preparation Example 1] Diamine compound (DB-6)

[0374] Preparation Example 1 is an example of preparing a diamine compound represented by the synthetic formula (DB-6). The reaction process is as follows: Reaction Process 1.

[0375]

[0376] Step 1-1

[0377] 11.6 g (0.1 mol) of 1,4-cyclohexanediol and 35.3 g (0.25 mol) of 1-fluoro-4-nitrobenzene were dissolved in 0.2 L of N,N-dimethylacetamide (DMAc), and then 56.1 g (0.4 mol) of potassium carbonate was added to form a mixture. The mixture was stirred at 180 °C for 3 hours, and the reaction product was obtained by filtration after the reaction.

[0378] Next, the reaction product was washed with 200g of methanol at 50°C for 1 hour, cooled and filtered, and then vacuum dried to obtain intermediate product 1 (dinitro compound).

[0379] Step 1-2

[0380] 35.8 g (0.1 mol) of the intermediate product 1 was dissolved in 1 L of a mixed solution of tetrahydrofuran (THF) and ethanol (volume ratio 2.5:1), followed by the addition of 7 g of palladium-carbon to obtain a mixture. The mixture was heated to 40 °C, and then 20.0 g (0.4 mol) of hydrazinium hydroxide was slowly titrated. After titration, the temperature was raised to 60 °C and stirred for 3.5 hours. The mixture was then filtered, and the filtrate was collected and subjected to vacuum filtration and drying to obtain the product [the diamine compound represented by formula (DB-6)].

[0381] [Preparation Example 2] Diamine compound (DB-7)

[0382] Preparation Example 2 is an example of preparing a diamine compound represented by the synthetic formula (DB-7). The reaction process is as follows: Reaction Process 2.

[0383]

[0384] In the reaction process 2, the process and the number of moles of reactants in steps 2-1 and 2-2 are approximately the same as those in steps 1-1 and 1-2, respectively. The difference is that 11.6 g (0.1 mol) of 1,4-cyclohexanediol in step 1-1 is replaced with 13.0 g (0.1 mol) of 2-methyl 1,4-cyclohexanediol in the same number.

[0385] [Preparation Example 3] Diamine compound (DB-8)

[0386] Preparation Example 3 is an example of preparing a diamine compound represented by the synthetic formula (DB-8), and the reaction process is as follows: Reaction Process 3.

[0387]

[0388] In the reaction process 3, the process and the number of moles of reactants in steps 3-1 and 3-2 are approximately the same as those in steps 1-1 and 1-2, respectively. The difference is that 35.3g (0.25mol) of 1-fluoro-4-nitrobenzene in step 1-1 is replaced with 35.3g (0.25mol) of 1-fluoro-3-nitrobenzene in the same number of moles.

[0389] [Preparation Example 4] Diamine compound (DB-9)

[0390] 13.9 g (0.1 mol) of reactant A and 29.2 g (0.1 mol) of reactant B were dissolved in 0.3 L of acetonitrile (ACN), and then 27.6 g (0.2 mol) of potassium carbonate was added to form a mixture. The mixture was then stirred at 77 °C for 4 hours, filtered, and the dried filtrate was collected. Next, the mixture was stirred and mixed with 1 L of methanol at 50 °C for 1 hour, filtered, and dried to collect a white solid, yielding the first intermediate product, as shown in Table 1.

[0391] 35.0 g (0.1 mol) of the first intermediate and 21.5 g (0.1 mol) of reactant C were dissolved in 1 L of ACN, and then 27.6 g (0.2 mol) of potassium carbonate were added to form a mixture. The mixture was stirred at 79 °C for 3 hours, and then filtered after reaction. Next, the reaction product was washed at 50 °C for 1 hour with a mixed solution of 500 g water and 150 g methanol. Then, it was cooled, filtered, and vacuum dried to obtain the second intermediate, as shown in Table 1.

[0392] 48.5 g (0.1 mole) of the second intermediate was dissolved in 2.5 L of a mixed solution containing THF and ethanol, followed by the addition of 9 g of palladium-carbon. The mixture was then heated to 40 °C, and 20.0 g (0.4 mole) of hydrazinium hydroxide was slowly titrated. After titration, the temperature was raised to 60 °C. After stirring for 3.5 hours, the mixture was filtered, and the filtrate was collected and subjected to reduced pressure filtration and vacuum drying to obtain the diamine compound represented by formula (DB-9), as shown in Table 1.

[0393] [Preparation Example 5] Diamine compound (DB-10)

[0394] Preparation Example 5 synthesized a diamine compound (DB-10) in a manner similar to that of Preparation Example 4, except that reactant B of Preparation Example 4 was replaced with 1,4-bis(bromomethyl)benzene to obtain the diamine compound shown in Formula (DB-10), as shown in Table 1.

[0395] Table 1

[0396]

[0397]

[0398]

[0399] [Preparation Example 6] Compound (C1-1)

[0400] 3.845 g (12 mmol) of reactant A and 8.746 g (52 mmol) of reactant B were dissolved in 90 mL of toluene. Reactant A was N... 1 N 1 N 6 N 6 -Tetra(2-hydroxyethyl)hexamethylenediamide, wherein reactant B is 1-tert-butoxycarbonylimidazolium, then 3.03 g (54 mmol) of potassium hydroxide (KOH) is added, and the mixture is stirred at 65 °C for 20 hours. After the reaction is complete, the reaction product is slowly added to a container containing 500 mL of water and stirred for 2 hours, followed by filtration to obtain a solid. The filtered solid is washed with 200 mL of ultrapure water to obtain compound (C1-1), as shown in Table 2.

[0401] [Preparation Example 7] Compound (C1-2)

[0402] Preparation Example 7 synthesized compound (C1-2) in a manner similar to that of Preparation Example 6, except that reactant A in Preparation Example 6 was replaced with N. 1 N 1 N 9 N 9 -Tetra(2-hydroxyethyl)nonadiamide was used to obtain compound (C1-2), as shown in Table 2.

[0403] [Preparation Example 8] Compound (C1-3)

[0404] Preparation Example 8 synthesized compound (C1-3) in a manner similar to that of Preparation Example 6, except that reactant A in Preparation Example 6 was replaced with N. 1 N 1 N 6 N 6 -Tetra(hydroxymethyl)hexamethylenediamide was used to obtain compound (C1-3), as shown in Table 2.

[0405] Table 2

[0406]

[0407]

[0408]

[0409] [Synthesis Example 1] First polymer (A1) - polyimide precursor

[0410] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 1.04 g (0.003 mol, 20 mol%) of diamine compound DB-1, 0.90 g (0.003 mol, 20 mol%) of diamine compound DB-6, 1.91 g (0.0045 mol, 30 mol%) of diamine compound DB-9, 3.05 g (0.0045 mol, 30 mol%) of diamine compound DB-11, and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and the mixture was stirred at 25 °C until dissolved. Next, 3.36 g (0.015 mol, 100 mol%) of compound DA-1 and 20 g of NMP were added, and the mixture was reacted at 25 °C for 2 hours to obtain a reaction solution. The reaction solution was poured into 1500 mL of water to precipitate the polymer. The precipitate was then filtered to obtain a filter cake. The filter cake was then washed with methanol and filtered again. This process was repeated three times to obtain a crude product. The crude product was then placed in a vacuum oven and dried at 60°C to obtain the first polymer (A1). The structures of the compounds corresponding to the numbered compounds are shown in Table 6.

[0411] [Synthetic Examples 2 to 8 and Comparative Synthetic Examples 1 to 3] First Polymer (A1) – Polyimide Precursor

[0412] The first polymer (A1) of Synthetic Examples 2 to 8 and Comparative Synthetic Examples 1 to 3 was prepared using a method similar to that of Synthetic Example 1. The difference was that the types and amounts of the tetracarboxylic acid dianhydride component (a1) and the diamine component (b1) of Synthetic Examples 2 to 8 and Comparative Synthetic Examples 1 to 3 were changed, as shown in Tables 3 to 4. The compound structures corresponding to the numbers of each compound are shown in Table 6.

[0413] [Synthesis Example 9] First polymer (A1) – imidized polymer

[0414] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 1.04 g (0.003 mol, 20 mol%) of diamine compound DB-1, 0.90 g (0.003 mol, 20 mol%) of diamine compound DB-6, 1.91 g (0.0045 mol, 30 mol%) of diamine compound DB-9, 3.05 g (0.0045 mol, 30 mol%) of diamine compound DB-11, and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and stirred at 25 °C until dissolved. Next, 3.36 g (0.015 mol, 100 mol%) of compound DA-1 and 20 g of NMP were added, and the mixture was reacted at 25 °C for 6 hours. Then, 97 g of N-methyl-2-pyrrolidone, 2.55 g of acetic anhydride, and 19.75 g of pyridine were added, and the mixture was heated to 60 °C and stirred continuously for 2 hours to carry out an imidization reaction, obtaining a reaction solution. The reaction solution was poured into 1500 mL of water to precipitate the polymer. The solution was then filtered to obtain a filter cake. The filter cake was then washed with methanol and filtered again. This process of washing and filtering with methanol was repeated three times to obtain a crude product. The crude product was then placed in a vacuum oven and dried at 60 °C to obtain the first polymer (A1). The structures of the compounds corresponding to the above compound numbers are shown in Table 6.

[0415] Table 3

[0416]

[0417]

[0418] Table 4

[0419]

[0420]

[0421] [Synthetic Example 10] Second polymer (A2) - polyimide precursor

[0422] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 3.97 g (0.02 mol, 100 mol%) of the diamine compound DB-13 and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added and stirred at 25 °C until dissolved. Next, 6.2 g (0.02 mol, 100 mol%) of compound DA-5 and 20 g of NMP were added, and the reaction was carried out at 25 °C for 2 hours to obtain a reaction solution. The reaction solution was poured into 1500 mL of water to allow the polymer to precipitate. The solution was then filtered to obtain a filter cake. The filter cake was then washed with methanol and filtered again, and this process was repeated three times to obtain a crude product. The crude product was then placed in a vacuum oven and dried at 60 °C to obtain the second polymer (A2). The structures of the compounds corresponding to the numbers of the above compounds are shown in Table 6.

[0423] [Synthetic Examples 11 to 12] Second Polymer (A2) - Polyimide Precursor

[0424] The second polymer (A2) of Synthetic Examples 11 to 12 was prepared using a method similar to that of Synthetic Example 10, except that the types and amounts of tetracarboxylic acid dianhydride component (a2) and diamine component (b2) were changed in Synthetic Examples 11 to 12, as shown in Table 5, and the compound structures corresponding to the numbers of each compound are shown in Table 6.

[0425] [Synthesis Example 13] Second polymer (A2) – imidized polymer

[0426] A nitrogen inlet, stirrer, condenser, and thermometer were installed on a 500 mL four-necked conical flask, and nitrogen gas was introduced. Then, 3.97 g (0.02 mol, 100 mol%) of the diamine compound DB-13 and 80 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) were added, and the mixture was stirred at 25 °C until dissolved. Next, 6.2 g (0.02 mol, 100 mol%) of compound DA-5 and 20 g of NMP were added, and the mixture was reacted at 25 °C for 6 hours. Then, 97 g of N-methyl-2-pyrrolidone, 2.55 g of acetic anhydride, and 19.75 g of pyridine were added, and the mixture was heated to 60 °C and stirred continuously for 2 hours to carry out the imidization reaction, obtaining a reaction solution. The reaction solution was poured into 1500 mL of water to allow the polymer to precipitate. The mixture was then filtered to obtain a filter cake. Next, the filter cake was washed with methanol and filtered again. This process was repeated three times to obtain a crude product. The crude product was then placed in a vacuum oven and dried at 60°C to obtain the second polymer (A2). The structures of the compounds corresponding to the above compound numbers are shown in Table 6.

[0427] Table 5

[0428]

[0429] Table 6

[0430]

[0431]

[0432]

[0433] [Example 1] Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

[0434] 50 parts by weight of the first polymer (A1) of Synthesis Example 1, 50 parts by weight of the second polymer (A2) of Synthesis Example 10, 1500 parts by weight of solvent B-1 (N-methyl-2-pyrrolidone), 500 parts by weight of solvent B-2 (ethylene glycol n-butyl ether), and 15 parts by weight of compound C1-1 were stirred and mixed at 25°C to obtain a liquid crystal alignment agent.

[0435] The liquid crystal alignment agent is spin-coated onto the pixel electrode of a glass substrate containing pixel electrodes. The pixel electrode is an IPS driving electrode having a pair of indium tin oxide (ITO) electrodes (10 μm wide, 10 μm spaced, and 50 nm high). The ITO electrodes are serrated, with the serrated portions arranged in a separated and interlocking manner. The glass substrate coated with the liquid crystal alignment agent is then dried on a heating plate at 80°C for 3 minutes, followed by baking in a hot air circulating oven at 250°C for 30 minutes to form a 100 nm thick film of liquid crystal alignment agent on the glass substrate. The film is then irradiated with 254 nm ultraviolet light through a polarizing plate, and then baked in a hot air circulating oven at 250°C for 30 minutes to form a liquid crystal alignment film, thus obtaining a first laminate containing the liquid crystal alignment film.

[0436] The liquid crystal alignment agent was spin-coated onto a glass substrate without pixel electrodes and having columnar spacers with a height of 4 μm. The glass substrate coated with the liquid crystal alignment agent was then dried on a heating plate at 80°C for 3 minutes, followed by baking in a hot air circulating oven at 250°C for 30 minutes to form a 100 nm thick film of the liquid crystal alignment agent on the glass substrate. The film was then irradiated with 254 nm ultraviolet light through a polarizing plate, and then baked in a hot air circulating oven at 250°C for 30 minutes to form a liquid crystal alignment film, thus obtaining a second laminate containing the liquid crystal alignment film.

[0437] A sealant is printed on one of the first and second laminates. Then, the liquid crystal alignment films of the first and second laminates are bonded together with their alignment directions at 0°. The sealant is then hardened to obtain a laminate containing an injection port and liquid crystal cell holes communicating with the injection port. Next, liquid crystal MLC-2041 (manufactured by Merck) is injected into the liquid crystal cell holes using a depressurized injection method, and the injection port is sealed to obtain a liquid crystal display element.

[0438] [Examples 2 to 9 and Comparative Examples 1 to 6] Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

[0439] Examples 2 to 9 and Comparative Examples 1 to 6 were obtained by a method similar to that of Example 1, in order to obtain liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element. The difference is that Examples 2 to 9 and Comparative Examples 1 to 6 changed the types and / or amounts of the first polymer (A1), the second polymer (A2), the solvent (B) and the compound (C) in the liquid crystal alignment agent, as shown in Tables 7 and 8, and the compound structure corresponding to the number of each compound is shown in Table 9.

[0440] [Evaluation Items]

[0441] The following description uses Example 1 as an example; the other examples and comparative examples are carried out in the same manner.

[0442] Intra-pixel contrast variability: The torsion angle change of the liquid crystal display element of Example 1 was measured using a Mueller matrix image polarizer (manufactured by AXOMETRICS, model AxoStep). The liquid crystal display element of Example 1 was placed on the measurement stage, and the distribution of circular retardation within the pixel was measured without applying voltage. The standard deviation (σ) was calculated as a factor of 3 (3σ). The smaller the standard deviation (3σ), the lower the intra-pixel contrast variability. The intra-pixel contrast variability was evaluated according to the following criteria.

[0443] ※:3σ≦2

[0444] ◎:2<3σ≦3

[0445] ○:3<3σ≦4

[0446] △:4<3σ≦5

[0447] X: 3σ>5

[0448] Friction-induced bright spots: The liquid crystal alignment agent of Example 1 was spin-coated onto a 100mm × 100mm glass substrate with an ITO conductive film. The glass substrate coated with the liquid crystal alignment agent was then dried on a heating plate at 80°C for 3 minutes, followed by baking in a hot air circulating oven at 230°C for 30 minutes to obtain a coating film with a thickness of 100nm formed on the glass substrate. The coating film was irradiated with ultraviolet light at a wavelength of 254nm through a polarizing plate, and then baked in a hot air circulating oven at 230°C for 30 minutes to obtain the first unit containing the liquid crystal alignment film.

[0449] Next, the spacer material was spin-coated onto a 100mm × 100mm plain glass substrate using a photosensitive resin composition. Then, it was pre-baked at 90°C for 150 seconds to form a pre-baked coating. Finally, using a photomask with a specific pattern, the pre-baked coating was exposed to light using an exposure machine (energy 60mJ / cm²). 2 After exposure, the sample is immersed in a potassium hydroxide aqueous solution containing 0.0438 wt% potassium hydroxide (KOH) for 70 seconds to remove unexposed areas. Then, it is washed with pure water and baked at 235°C for 30 minutes to obtain the second unit containing the interstitial body.

[0450] Subsequently, the first unit containing the liquid crystal alignment film and the second unit containing the spacer were connected in a manner that brought the liquid crystal alignment film into contact with the spacer to form a test unit. Next, using an abrasion testing machine (manufactured by Yangyi Technology Co., Ltd., model QC-621H), pressure was applied to the first unit side of the test unit with a 2000-gram grinding wheel in a first direction parallel to the stacking direction of the first and second units, and the test unit was rubbed in a second direction perpendicular to the stacking direction. The minimum number of rubbing cycles required for scratches to appear on the surface of the liquid crystal alignment film was observed and recorded. The abrasion testing machine moved 4 cm at a speed of 2 cm / second, with one round trip counted as one cycle, and a total of 150 cycles were performed.

[0451] Two first units containing the liquid crystal alignment film, having undergone the aforementioned abrasion testing, were prepared. One of the first units was mounted on an abrasion tester (Bruker AXS, model UMT-2, sensor FVL, with a 1.6mm sapphire ball at the tip of the device). A scratch test was performed for 100 seconds, ranging from 1mN to 20mN, at a horizontal axis of 0.5mm (5mm / s) and a moving direction of 2mm. Then, liquid crystal MLC-2041 (Merck) was dropped onto it. For the other first unit, 4μm gaps were scattered, and the gaps were clamped towards the side of the first unit where the liquid crystal MLC-2041 was dropped. The clamped substrate was observed at a 90-degree angle with a polarizing microscope (ECLIPSE E600WPOL, Nikon) to the polarizing plate, observing the area where the scratch test had been performed. The light transmission was observed, and the results were evaluated based on the number of bright spots and the following criteria.

[0452] ※: The number of sparks from friction is ≤ 5.

[0453] ◎: 6 points ≤ Number of sparks from friction ≤ 9 points

[0454] ○: 10 points ≤ Number of sparks from friction ≤ 12 points

[0455] △: 13 points ≤ number of friction sparks ≤ 15 points

[0456] ╳: The number of sparks from friction is ≥16.

[0457] It should be noted that, unlike conventional abrasion resistance testing methods, if the present invention only applies friction of 850 rpm to 1500 rpm to the first unit containing the liquid crystal alignment film and evaluates the difference in haze value of the liquid crystal alignment film before and after friction, in the embodiments and comparative examples of the present invention, it is difficult to observe the difference between the two, and therefore cannot be used as an evaluation basis. Furthermore, in the conventional abrasion resistance testing method, the liquid crystal alignment film in the curved liquid crystal panel of the present invention is rubbed by the spacer, resulting in pressure being applied by the spacer, which prevents the liquid crystal alignment film from adjusting the alignment of liquid crystal molecules, thereby causing the liquid crystal display element to produce bright spots and making it difficult to form a bond.

[0458] Table 7

[0459]

[0460]

[0461] Table 8

[0462]

[0463]

[0464] Table 9

[0465]

[0466]

[0467] Referring to Tables 3 and 7, the liquid crystal alignment agents of Examples 1 to 9 were prepared using the first polymer (A1) of Synthetic Examples 1 to 9, the second polymer (A2) of Synthetic Examples 10 to 13, and the compound (C) of Preparation Examples 6 to 8. In particular, the first polymer (A1) of Synthetic Examples 1 to 9 was prepared using a tetracarboxylic acid dianhydride component (a1) and a diamine component (b1) containing a diamine compound (b1-1), and the compound (C) of Preparation Examples 6 to 8 contained the structure shown in formula (C1). Therefore, the liquid crystal alignment film formed by the liquid crystal alignment agents of Examples 1 to 9 can impart low intra-pixel contrast variation and scuffing spots to the liquid crystal display element, indicating that the liquid crystal display element of Examples 1 to 9 has good display quality.

[0468] Referring to Tables 4 and 8, in contrast to Comparative Examples 1 to 6, the liquid crystal alignment agents of Comparative Examples 1 to 3 and Comparative Examples 5 to 6 were prepared using the first polymer (A1) of Comparative Synthesis Examples 1 to 3. However, the diamine component (b1) used in the first polymer (A1) of Comparative Synthesis Example 1 did not contain a diamine compound (b1-1). Therefore, the liquid crystal display elements of Comparative Examples 1 to 3 and Comparative Examples 5 to 6 exhibited high intra-pixel contrast variation and scuffing spots, indicating poor display quality. Furthermore, the liquid crystal alignment agents of Comparative Examples 2 to 3 and Comparative Examples 5 to 6 also did not use a compound (C) containing the structure shown in formula (C1). Therefore, the liquid crystal display elements of Comparative Examples 2 to 3 and Comparative Examples 5 to 6 exhibited high intra-pixel contrast variation and scuffing spots, indicating poor display quality. The liquid crystal alignment agent of Comparative Example 4 did not use a compound (C) containing the structure shown in Formula (C1). Therefore, the liquid crystal display element of Comparative Example 4 has high intra-pixel contrast variation and friction breakage, indicating that the display quality of the liquid crystal display element of Comparative Example 4 is poor.

[0469] In summary, the liquid crystal alignment agent of the present invention uses the first polymer (A1) obtained by using a polyimide precursor containing the structure shown in formula (I) and the compound (C) containing the structure shown in formula (C1), thereby enabling the liquid crystal alignment film formed using the liquid crystal alignment agent to impart low intra-pixel contrast variation and scuffing spots to the liquid crystal display element. Therefore, the liquid crystal display element containing the liquid crystal alignment film has good display quality, thus achieving the objective of the present invention.

[0470] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the patent of the present invention.

Claims

1. A liquid crystal alignment agent, characterized in that: The liquid crystal alignment agent comprises: Polymer component (A) includes a first polymer (A1), wherein the first polymer (A1) is selected from at least one of the group consisting of a polyimide precursor and an imidized polymer of the polyimide precursor; Solvent (B); and Compound (C); The polyimide precursor of the first polymer (A1) comprises a structure as shown in formula (I). In equation (I), X 1 Selected from at least one of the groups consisting of structures as shown in equations (I-1) to (I-7), where "*" indicates the bond location. In the above formula (I-1), X 11 X 12 X 13 and X 14 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group, in the formulas (I-7), X 15 and X 16 Each can be independently a hydrogen atom or a methyl group; X 2 Each is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; A 3 and A 4 Each is an independently substituted or unsubstituted divalent aromatic cyclic group; Y 21 and Y 22 Each independently represents a single bond, oxygen atom, sulfur atom, or R 2 Represents a protective base, and the Y 21 and the Y 22 At least one of them is And the Y 21 With the Y 22 Different; Z 2 It is a divalent organic group having at least one of a chain hydrocarbon structure and an alicyclic hydrocarbon structure and having 1 to 15 carbon atoms; The compound (C) comprises a structure as shown in formula (C1). In the formula (C1), A is a monovalent to tetravalent organic group. n is an integer from 1 to 4. L 1 L 2 Each is independently an alkylene group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. R 3 R 4 Each can be represented independently as shown in equation (C2). In the above formula (C2), R 5 It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

2. The liquid crystal alignment agent according to claim 1, characterized in that: The X 1 The structure is as shown in equation (I-1).

3. The liquid crystal alignment agent according to claim 1, characterized in that: The X 1 The structure is as shown in equation (I-1-1).

4. The liquid crystal alignment agent according to claim 1, characterized in that: The R 2 The protecting group indicated is a carbamate-based protecting group.

5. The liquid crystal alignment agent according to claim 1, characterized in that: The structure shown in formula (I) is the same as the structure shown in formula (II). In the aforementioned formula (II), Q 1 and Q 2 Each can independently represent -CH- or nitrogen atom. X 1 X 2 Y 21 and Y 22 The definition of X in equation (I) 1 X 2 Y 21 and Y 22 same, m 1 Represents integers from 1 to 5.

6. The liquid crystal alignment agent according to claim 1, characterized in that: The R 5 It is an alkyl group having 3 to 10 carbon atoms or a haloalkyl group having 10 to 15 carbon atoms.

7. The liquid crystal alignment agent according to claim 1, characterized in that: The n is an integer from 2 to 4.

8. The liquid crystal alignment agent according to claim 1, characterized in that: Equation (C1) is the structure shown in equation (C3). In the aforementioned formula (C3), A' is an alkylene group having 1 to 10 carbon atoms. L 1’ To L 4’ Each is independently an alkylene group having 1 to 5 carbon atoms. R 3’ To R 6’ Each can be independently represented as shown in equation (C4). In the aforementioned formula (C4), R 5 It is an alkyl group having 1 to 20 carbon atoms or a haloalkyl group having 1 to 20 carbon atoms.

9. A liquid crystal alignment film, characterized in that: The liquid crystal alignment film is formed using the liquid crystal alignment agent as described in any one of claims 1 to 8.

10. The liquid crystal alignment film according to claim 9, characterized in that: The liquid crystal alignment film is formed using the liquid crystal alignment agent as described in any one of claims 1 to 8 and by performing a photoalignment process.

11. A liquid crystal display element, characterized in that: The liquid crystal display element includes the liquid crystal alignment film as described in claim 9 or 10.

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