TW202227601A - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

A liquid crystal aligning agent containing at least one type of polymer (A) selected from: a polyamide precursor that has a repeating unit (a1) shown in formula (1), wherein Y1 represents an organic group shown in formula (H), and a repeating unit (a2) shown in formula (2), wherein Y2 represents an organic group shown in formula (O); and a polyimide that is an imidized product of the polyimide precursor. In formula (H), at least one R represents a halogen atom or a halogenated alkyl group. In formula (O), Ar each independently represent a benzene ring, a biphenyl structure, or a naphthalene ring, wherein any hydrogen atom may be substituted by a halogen atom or a monovalent organic group. Q2 represents a -(CH2)n- that may be partially substituted by -O-, -C(=O)-, or -O-C(=O)- (n being an integer 2-18).

Description

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

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

Conventionally, liquid crystal display devices have been widely used as display units such as personal computers, smart phones, mobile phones, and television receivers. A liquid crystal display device, for example, includes a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, an alignment film for regulating the alignment of liquid crystal molecules in the liquid crystal layer, and a switching device. Thin film transistors (TFTs) that supply electronic signals to pixel electrodes, etc. As a driving method of liquid crystal molecules, vertical electric field methods such as TN method and VA method, and lateral electric field methods such as in-plane switching (IPS) method and fringe field switching (FFS) method are known.

At present, the most popular liquid crystal alignment film in the industry is the surface of the film formed on the electrode substrate made of polyamide and/or polyimide obtained by imidization of it, cotton, nylon, polyamide, etc. It is produced by rubbing fabrics such as esters in one direction, which means rubbing them. The rubbing treatment is an industrially simple and useful method with excellent productivity. However, with the higher performance, higher definition, and larger size of liquid crystal display elements, damage to the surface of the alignment film caused by the rubbing treatment, dust, mechanical force or static electricity, and even the inhomogeneity of the alignment treatment surface Sex and other issues became more apparent. As an alignment treatment method in place of the rubbing treatment, a photo-alignment method for imparting alignment ability to a liquid crystal by irradiating polarized radiation is known. The photoalignment method has been proposed using a photoisomerization reaction, a photocrosslinking reaction, and a photolysis reaction (for example, see Non-Patent Document 1, Patent Document 1, and Patent Document 2). [Prior Technology Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Publication No. Hei 9-297313 [Patent Document 2] WO2016/152928 [Non-Patent Document]

[Non-Patent Document 1] "Liquid crystal photo-alignment film" Kidowaki, Ichimura Functional Materials, Nov. 1997 Vol.17, No.11, p13-22

[Problems to be Solved by Invention]

In the case of performing the alignment treatment by the photo-alignment method, the irradiation amount of light becomes a factor affecting the energy cost or the production speed, so it is preferable to perform the alignment treatment with a small irradiation amount. However, under the review of the present inventors, even with a liquid crystal aligning agent that can obtain good liquid crystal alignment under the condition of a large irradiation amount, when the light irradiation amount is reduced, the liquid crystal alignment in the liquid crystal alignment film plane will become Variation (non-uniformity) is easily generated, and the variation of the liquid crystal twist angle within the plane of the liquid crystal display element also increases. It is worrying that, in this way, when the liquid crystal display element displays black, the in-plane brightness will vary, and the display quality will be degraded.

In addition, the liquid crystal alignment film used in the liquid crystal display element of the IPS driving mode or the FFS mode must also have an alignment regulation force for suppressing the occurrence of image afterimage (hereinafter referred to as AC afterimage) due to long-term AC driving.

Here, an object of the present invention is to provide a liquid crystal alignment film capable of suppressing variation (non-uniformity) in liquid crystal alignment within the plane of the liquid crystal alignment film even if the light irradiation amount for alignment treatment by the photo-alignment method is reduced, and The liquid crystal alignment agent used to obtain the liquid crystal alignment film, and the liquid crystal display element using the liquid crystal alignment film. Furthermore, an object of the present invention is to provide a liquid crystal alignment film having excellent liquid crystal alignment regulation force capable of suppressing AC image sticking, a liquid crystal alignment agent for obtaining the liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film. [How to solve the problem]

As a result of intensive research, the inventors of the present invention found that the above-mentioned problems can be solved by using a liquid crystal aligning agent containing a specific component, and completed the present invention. Specifically, the gist of the present invention is as follows.

A liquid crystal alignment agent, characterized in that it contains a polymer (A), and the polymer (A) is selected from the group consisting of a polyimide precursor and an imide compound serving as the polyimide precursor. At least one polymer in the group of , and the polyimide precursor has a repeating unit (a1) represented by the following formula (1) and a repeating unit (a2) represented by the following formula (2).

式(1)中，R ₁至R ₄各自獨立，表示氫原子、鹵素原子、碳數為1～6之烷基、碳數為2～6之烯基、碳數為2～6之炔基、含有氟原子之碳數1～6之1價有機基、或苯基，R ₁至R ₄中至少一個是上述定義中之氫原子以外的基。R及Z各自獨立，表示氫原子或碳數為1～6之烷基。Y ₁為下述式(H)表示的2價有機基。 [化2]

式(H)中，R各自獨立，表示氫原子、鹵素原子、碳數為1～3之烷基、或碳數1～3之烷基上的氫原子的至少一部分被鹵素原子取代之鹵化烷基，至少一個R為鹵素原子或上述鹵化烷基。＊表示原子鍵結。 [hua 1]

In formula (1), R ₁ to R ₄ are each independently and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkynyl group having 2 to 6 carbon atoms. , a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and at least one of R ₁ to R ₄ is a group other than a hydrogen atom as defined above. R and Z are each independently and represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y ₁ is a divalent organic group represented by the following formula (H). [hua 2]

In formula (H), R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl halide in which at least a part of hydrogen atoms on an alkyl group having 1 to 3 carbon atoms is substituted by a halogen atom group, at least one R is a halogen atom or the above-mentioned halogenated alkyl group. * Indicates atomic bonding.

式(2)中，R ₁至R ₄、R、及Z是與上述式(1)同義。Y ₂為下述式(O)表示之2價有機基 [hua 3]

In the formula (2), R ₁ to R ₄ , R, and Z have the same meanings as in the above-mentioned formula (1). Y ₂ is a divalent organic group represented by the following formula (O)

式(O)中，Ar各自獨立，表示苯環、聯苯結構、或萘環。Ar所擁有的苯環或萘環上的任意氫原子，亦可被鹵素原子或1價有機基取代。Q ₂表示-(CH ₂) _n-(n為2～18的整數)、或上述-(CH ₂) _n-的一部分被-O-、-C(＝O)-或-O-C(＝O)-任一者取代之基。＊表示原子鍵結。 [發明之效果] [hua 4]

In formula (O), Ar each independently represents a benzene ring, a biphenyl structure, or a naphthalene ring. Any hydrogen atom on the benzene ring or naphthalene ring possessed by Ar may be substituted by a halogen atom or a monovalent organic group. Q ₂ represents -(CH ₂ ) _n - (n is an integer of 2 to 18), or a part of the above -(CH ₂ ) _n - is replaced by -O-, -C(=O)- or -OC(=O) -Any one of the substituted groups. * Indicates atomic bonding. [Effect of invention]

According to the present invention, it is possible to provide a liquid crystal alignment film capable of suppressing variation (non-uniformity) in the liquid crystal alignment within the surface of the liquid crystal alignment film even if the light irradiation amount for the alignment treatment by the photo-alignment method is reduced, and a liquid crystal alignment film for obtaining the same. A liquid crystal alignment agent for a liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film. Furthermore, the present invention can provide a liquid crystal alignment film having excellent liquid crystal alignment regulation force capable of suppressing AC sticking, a liquid crystal alignment agent for obtaining the liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film.

<Polymer (A)> The liquid crystal aligning agent of the present invention contains a polymer (A), and the polymer (A) is selected from the group consisting of a polyimide precursor and a polyimide compound serving as the polyimide precursor. A polymer of at least one type in the group, wherein the polyimide precursor has a repeating unit (a1) represented by the following formula (1) and a repeating unit (a2) represented by the following formula (2). When the polymer (A) contains at least any one of the repeating unit (a1) and its imidized structure, it is possible to suppress a decrease in contrast caused by variation in the twist angle in the plane of the liquid crystal display element that occurs during production. Moreover, the polymer (A) can obtain a liquid crystal display element excellent in contrast by further containing at least any one of the said repeating unit (a2) and its imidization structure. With the above synergistic effects, a liquid crystal display element with high liquid crystal alignment and excellent contrast can be obtained from the liquid crystal aligning agent of the present invention.

式(1)中，R ₁至R ₄各自獨立，表示氫原子、鹵素原子、碳數為1～6之烷基、碳數為2～6之烯基、碳數為2～6之炔基、含有氟原子之碳數1～6之1價有機基、或苯基，R ₁至R ₄中至少一個是上述定義中之氫原子以外的基。R及Z各自獨立，表示氫原子或碳數為1～6之烷基。Y ₁為下述式(H)表示的2價有機基。此外，上述定義中之氫原子以外的基是指，鹵素原子、碳數為1～6之烷基、碳數為2～6之烯基、碳數為2～6之炔基、含有氟原子之碳數1～6之1價有機基、及苯基。 [hua 5]

In formula (1), R ₁ to R ₄ are each independently and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkynyl group having 2 to 6 carbon atoms. , a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and at least one of R ₁ to R ₄ is a group other than a hydrogen atom as defined above. R and Z are each independently and represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y ₁ is a divalent organic group represented by the following formula (H). In addition, the group other than a hydrogen atom in the above definition refers to 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, and a fluorine atom-containing group. A monovalent organic group with 1 to 6 carbon atoms, and a phenyl group.

式(H)中，R各自獨立，表示氫原子、鹵素原子、碳數為1～3之烷基、或碳數1～3之烷基上的氫原子的至少一部分被鹵素原子取代之鹵化烷基，至少一個R為鹵素原子或上述鹵化烷基。＊表示原子鍵結。 [hua 6]

In formula (H), R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl halide in which at least a part of hydrogen atoms on an alkyl group having 1 to 3 carbon atoms is substituted by a halogen atom group, at least one R is a halogen atom or the above-mentioned halogenated alkyl group. * Indicates atomic bonding.

式(2)中，R ₁至R ₄、R、及Z是與上述式(1)同義。Y ₂為下述式(O)表示之2價有機基。 [hua 7]

In the formula (2), R ₁ to R ₄ , R, and Z have the same meanings as in the above-mentioned formula (1). Y ₂ is a divalent organic group represented by the following formula (O).

式(O)中，Ar各自獨立，表示苯環、聯苯結構、或萘環。Ar所擁有的苯環或萘環上的任意氫原子，亦可被鹵素原子或1價有機基取代。Q ₂表示-(CH ₂) _n-(n為2～18的整數)、或上述-(CH ₂) _n-的一部分被-O-、-C(＝O)-或-O-C(＝O)-任一者取代之基。＊表示原子鍵結。 [hua 8]

In formula (O), Ar each independently represents a benzene ring, a biphenyl structure, or a naphthalene ring. Any hydrogen atom on the benzene ring or naphthalene ring possessed by Ar may be substituted by a halogen atom or a monovalent organic group. Q ₂ represents -(CH ₂ ) _n - (n is an integer of 2 to 18), or a part of the above -(CH ₂ ) _n - is replaced by -O-, -C(=O)- or -OC(=O) -Any one of the substituted groups. * Indicates atomic bonding.

Specific examples of the alkyl group having 1 to 6 carbon atoms in R ₁ to R ₄ include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and tertiary butyl. , tertiary butyl, n-pentyl, etc. Specific examples of the alkenyl groups having 2 to 6 carbon atoms in the above R ₁ to R ₄ include vinyl groups, propenyl groups, butenyl groups, and the like, and these may be linear or branched. Specific examples of the alkynyl group having 2 to 6 carbon atoms in the above R ₁ to R ₄ include an ethynyl group, a 1-propynyl group, a 2-propynyl group, and the like. Specific examples of the halogen atoms in the above R ₁ to R ₄ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Specific examples of the monovalent organic groups having 1 to 6 carbon atoms in which R ₁ to R ₄ contain a fluorine atom include fluoromethyl, trifluoromethyl, pentafluoroethyl, and pentafluoropropyl. In addition, from the viewpoint of efficiently obtaining the effects of the present invention, at least one of R ₁ to R ₄ is a group other than the hydrogen atom in the above definition. By setting the above structure, the photoreactivity of the polyimide film is increased, and the in-plane anisotropy of the obtained liquid crystal alignment film is increased, so that the variation in the in-plane twist angle of the liquid crystal display element generated during manufacture can be suppressed. The resulting drop in contrast. More preferred combinations of R ₁ to R ₄ are as follows, preferably R ₁ to R ₄ are hydrogen atoms or methyl groups, at least one of R ₁ to R ₄ is methyl, more preferably at least 2 of R ₁ to R ₄ One is methyl. More preferably, R ₁ and R ₄ are methyl groups, and R ₂ and R ₃ are hydrogen atoms.

In R in the above formula (H), the halogen atom and the alkyl group having 1 to 3 carbon atoms include the structures exemplified by the above R ₁ to R ₄ , and the halogenated alkyl group includes fluoromethyl, Trifluoromethyl, pentafluoroethyl, pentafluoropropyl, etc. Among these, from the viewpoint of efficiently obtaining the effects of the present invention, the halogen atom is preferably a fluorine atom and a chlorine atom, and the halogenated alkyl group is preferably a fluoromethyl group and a trifluoromethyl group.

The divalent organic group represented by the above formula (H) is preferably represented by any one of the following formulae (h-1) to (h-9) from the viewpoint of efficiently obtaining the effects of the present invention. The divalent organic group is more preferably a divalent organic group represented by any one of (h-1) to (h-2), (h-6) to (h-7), and (h-9).

式(h-1)～(h-9)中，＊表示原子鍵結。 [Chemical 9]

In the formulae (h-1) to (h-9), * represents an atomic bond.

Any hydrogen atom on the benzene ring or naphthalene ring possessed by Ar in the above formula (O) may also be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. A monovalent organic group such as an alkynyl group of 6 and a monovalent organic group of 1 to 6 carbon atoms containing a fluorine atom is substituted. Specific examples of these monovalent organic groups include the structures exemplified by the above-mentioned R ₁ to R ₄ . The divalent organic group represented by the above formula (O) is preferably a divalent organic group represented by any one of the following formulae (o-1) to (o-14) from the viewpoint of improving liquid crystal alignment. .

[化11]

式(o-1)～(o-14)中，＊表示原子鍵結。式(o-14)中，2個m各自獨立。 [Chemical 10]

[Chemical 11]

In formulas (o-1) to (o-14), * represents an atomic bond. In formula (o-14), two m's are independent of each other.

式(2’)、及式(3)中，X _2’、及X ₃表示4價有機基，Y _2’為下述式(O2)表示的2價有機基，Y ₃表示分子內有「-N(D)-(D表示胺甲酸酯系保護基)」基，且除了D之外的碳數為6～30之2價有機基。R及Z與上述式(1)同義。 [化13]

式(O2)中，Ar _2’各自獨立，表示苯環，該苯環上的任意氫原子，亦可被碳數1～6的烷基取代。Q _2’表示單鍵，或-O-。m表示0～2的整數。＊表示原子鍵結。 The above-mentioned polymer (A) may further be a polyimide selected from the group consisting of polyimide precursors and imide compounds serving as the polyimide precursors from the viewpoint of efficiently obtaining the effects of the present invention. A polymer of at least one of the group consisting of amines, wherein the polyimide precursor has a repeating unit (a2') represented by the following formula (2') and a repeating unit (a2') represented by the following formula (3) Unit (a3) constitutes at least one of the groups. That is, the polymer (A) may be at least 1 polymer selected from the group consisting of a polyimide precursor and a polyimide that is an imide compound of the polyimide precursor, and The polyimide precursor has a repeating unit (a1) represented by the formula (1), a repeating unit (a2) represented by the formula (2), a repeating unit (a2') represented by the formula (2'), and a repeating unit (a2') represented by the formula (1). The repeating unit (a3) represented by (3) constitutes at least one of the groups. [Chemical 12]

In formula (2') and formula (3), X _2' and X ₃ represent a tetravalent organic group, Y _2' is a divalent organic group represented by the following formula (O 2 ), and Y ₃ represents a molecule containing " -N(D)-(D represents a urethane-based protecting group)" group, and the carbon number other than D is a divalent organic group having 6 to 30 carbon atoms. R and Z are synonymous with the above formula (1). [Chemical 13]

In formula (O2), Ar _2' each independently represents a benzene ring, and any hydrogen atom on the benzene ring may be substituted by an alkyl group having 1 to 6 carbon atoms. Q _2' represents a single bond, or -O-. m represents an integer of 0-2. * Indicates atomic bonding.

As X _2' and X ₃ , in addition to the tetravalent organic group represented by the following formula (g), a tetravalent organic group represented by any one of the following formulae (X-1) to (X-25) can be mentioned groups, tetravalent organic groups derived from aromatic tetracarboxylic dianhydrides, and the like. From the viewpoint of efficiently obtaining the effects of the present invention, X _2' and X ₃ are more preferably tetravalent organic groups represented by the following formula (g).

R ₁、R ₂、R ₃、及R ₄，是與上述式(1)之R ₁、R ₂、R ₃、及R ₄同義。＊表示原子鍵結。 [Chemical 14]

R ₁ , R ₂ , R ₃ , and R ₄ are synonymous with R ₁ , R ₂ , R ₃ , and R ₄ in the above formula (1). * Indicates atomic bonding.

[化16]

式(X-1)～(X-25)中，＊表示原子鍵結。 [Chemical 15]

[Chemical 16]

In the formulae (X-1) to (X-25), * represents an atomic bond.

Here, the aromatic tetracarboxylic dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of a carboxyl group bonded to an aromatic ring such as a benzene ring and a naphthalene ring. Specific examples of the tetravalent organic group derived from the aromatic tetracarboxylic dianhydride include the tetravalent organic group represented by any one of the following formulae (Xa-1) to (Xa-2), A tetravalent organic group represented by any one of the following formulae (Xr-1) to (Xr-7).

x及y各自獨立，為單鍵、醚鍵、羰基、酯鍵、碳數1～10之烷二基、1,4-伸苯基、磺醯基、或醯胺基。j及k為0或1之整數。＊表示原子鍵結。 [Chemical 17]

x and y are each independently, and are a single bond, an ether bond, a carbonyl group, an ester bond, an alkanediyl group having 1 to 10 carbon atoms, a 1,4-phenylene group, a sulfonyl group, or an amido group. j and k are integers of 0 or 1. * Indicates atomic bonding.

式(Xr-1)～(Xr-7)中，＊表示原子鍵結。 [Chemical 18]

In the formulae (Xr-1) to (Xr-7), * represents an atomic bond.

The tetravalent organic group represented by the above formula (Xa-1) or (Xa-2) may have a structure represented by any one of the following formulae (Xa-3) to (Xa-19).

[Chemical 19]

式(Xa-3)～(Xa-19)中，＊表示原子鍵結。 [hua 20]

In the formulae (Xa-3) to (Xa-19), * represents an atomic bond.

The divalent organic group represented by the above formula (O2) is preferably a divalent organic group represented by any one of the following formulae (o2-1) to (o2-3) from the viewpoint of less occurrence of AC afterimages organic base.

式(o2-1)～(o2-3)中，＊表示原子鍵結。 [Chemical 21]

In the formulae (o2-1) to (o2-3), * represents an atomic bond.

D of the above-mentioned Y ₃ represents a urethane-based protecting group, and examples of the urethane-based protecting group include tertiary butoxycarbonyl and 9-fluorenylmethoxycarbonyl. As a specific example of the said _Y3 , the divalent organic group represented by following formula (Dx) is mentioned.

式(Dx)中，＊表示原子鍵結。 [Chemical 22]

In the formula (Dx), * represents an atomic bond.

In the formula, Q ₅ is a single bond, -(CH ₂ ) _n - (n is an integer of 1 to 20), or any -CH ₂ - of -(CH ₂ ) _n - by -O-, -COO-, -OCO-, -NQ _{9 -, -NQ 9 CO-, -CONQ 9 -} , -NQ ₉ -CO-NQ ₁₀ -, _{-NQ 9} -COO-, or -OCOO- substituted group, Q ₉ and Q ₁₀ Each independently represents a hydrogen atom or a monovalent organic group. Q ₆ and Q ₇ are each independently and represent -H, a group having -NHD (preferably -NHD), or a group having -N(D) ₂ (preferably -N(D) ₂ ). However, when m=0, Q ₆ has a urethane-based protecting group, and when m=1, at least one of Q ₅ , Q ₆ , and Q ₇ has a urethane-based protecting group in the group. In addition, when Q ₆ and Q ₇ represent a group other than a hydrogen atom, the preferred number of carbon atoms is 1 to 8. Examples of the monovalent organic group of the above-mentioned Q ₉ and Q ₁₀ include 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, and a fluorine atom-containing group. The monovalent organic group having 1 to 6 carbon atoms includes the structures exemplified by the above R ₁ to R ₄ as a specific example.

As a preferable specific example of _Y3 , the divalent organic group represented by any one of following formula (Y3-1) - (Y3-5) is mentioned from a viewpoint of less AC image sticking. "Boc" represents a tertiary butoxycarbonyl group. * Indicates atomic bonding.

[Chemical 23]

The above-mentioned polymer (A) may also be at least one polymer selected from the group consisting of a polyimide precursor and a polyimide compound which is an imide compound of the polyimide precursor, and the polymer The polyimide precursor has a repeating unit (a4) represented by the following formula (4) in addition to the repeating unit (a1), repeating unit (a2), repeating unit (a2'), and repeating unit (a3).

[Chemical 24]

In the formula, X ₄ represents a tetravalent organic group, and Y ₄ represents a divalent organic group. R and Z are synonymous with R and Z in the above formula (1), respectively. However, Y ₄ represents a divalent organic group having "-N(D)-(D represents a urethane-based protecting group)" group in the molecule and having a carbon number of 6 to 30 other than D, and the above formula A structure other than the divalent organic group represented by (O2), and further, when _X4 is synonymous with the _tetravalent organic group represented by the above formula (g), Y4 is the divalent organic group represented by the above formula (H), and the above A structure other than the divalent organic group represented by the formula (O). Specific examples of X ₄ include the structures exemplified by X _2′ and X ₃ .

Specific examples of X ₄ include tetravalent organic groups exemplified by X _2' above. From the viewpoint of efficiently obtaining the effects of the present invention, X ₄ is more preferably a tetravalent organic group represented by the above formula (g), or any one of the above formulas (X-1) to (X-25). The tetravalent organic group is more preferably the tetravalent organic group represented by the above formula (g).

As specific examples of the divalent organic group of Y ₄ , in addition to the divalent organic group represented by the above formula (H), the divalent organic group represented by the above formula (O), the divalent organic group represented by the above formula (O2), the molecular In addition to the divalent organic group having "-N(D)-(D represents a urethane-based protecting group)" group and having a carbon number of 6 to 30 other than D, the following removal from diamine is exemplified. A divalent organic group with 2 amine groups. Examples include the following divalent organic group obtained by removing two amine groups from diamine, and groups represented by any one of the formulae (Y-1) to (Y-167) described in WO2018/117239: 4,4 '-diaminediphenylmethane; diamines having photoalignment groups such as diamines represented by the following formulae (g-1) to (g-5); the following formulas (u-1) to (u-3 Diamines having urea bonds such as diamines represented by ); diamines having amide bonds such as diamines represented by the following formulae (u-4) to (u-6); A ring, a secondary amine group and a tertiary amine group constitute at least one of the nitrogen atom-containing structures in the group (hereinafter also referred to as nitrogen atom-containing structures.) Diamines; 2,4-diaminephenol, 3,5 -Diaminephenol, 3,5-diaminebenzyl alcohol, 2,4-diaminebenzyl alcohol, 4,6-diamineresorcinol; 2,4-diaminebenzoic acid, 2,5-diaminebenzene Diamines having carbonyl groups such as formic acid, 3,5-diaminebenzoic acid, and diamine compounds represented by the following formulae (3b-1) to (3b-4); 4-(2-(methylamino)ethyl yl)aniline, 4-(2-aminoethyl)aniline, 4,4'-diaminediphenyl ketone, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indene Alkan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indan-6-amine; 2-(2, methacrylic acid) Diamines having a photopolymerizable group at the terminal such as 4-diaminophenoxy)ethyl and 2,4-diamino-N,N-diallylaniline; Cholestaalkoxy-3,5 -cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene , 3,5-diaminobenzoic acid cholestyl, 3,5-diaminobenzoic acid cholestyl, 3,5-diaminobenzoic acid lanostanyl, and Diamines having cholesterol skeletons such as 3,6-bis(4-aminobenzyloxy)cholestane; diamines represented by the following formulae (V-1) to (V-6); 1,3-bis( 3-Aminopropyl)-tetramethyldisiloxane and other diamines with siloxane bonds; the following formulas (Ox-1)～(Ox-2) and the like have oxazoline ring structure two Amine; 1-(4-(2-(2,4-diaminephenoxy)ethoxy)phenyl)-2-hydroxy-2-methylacetone, 2-(4-(2-hydroxy-2 -Methylpropionyl)phenoxy)ethyl 3,5-diamine benzoate, 4,4'-diamine diphenyl ketone, 3,3'-diamine diphenyl ketone, etc. have free Diamines, etc., with the function of base polymerization initiators.

[化26]

[化27]

上述(3b-1)中，A ¹表示單鍵、-CH ₂-、-C ₂H ₄-、-C(CH ₃) ₂-、-CF ₂-、-C(CF ₃) ₂-、-O-、-CO-、-NH-、-N(CH ₃)-、-CONH-、-NHCO-、-CH ₂O-、-O-CH ₂-、-COO-、-OCO-、-CO-N(CH ₃)-或-N(CH ₃)-CO-，m1及m2各自獨立，表示0～4之整數，且m1+m2為1～4之整數。式(3b-2)中，m3及m4各自獨立，表示1～5之整數。式(3b-3)中，A ²為碳數1～5之直鏈或分枝烷基，m5表示1～5之整數。式(3b-4)中，A ³及A ⁴各自獨立，表示單鍵、-CH ₂-、-C ₂H ₄-、-C(CH ₃) ₂-、-CF ₂-、-C(CF ₃) ₂-、-O-、-CO-、-NH-、-N(CH ₃)-、-CONH-、-NHCO-、-CH ₂O-、-OCH ₂-、-COO-、-OCO-、-CO-N(CH ₃)-或-N(CH ₃)-CO-，m6表示1～4之整數。 [Chemical 25]

[Chemical 26]

[Chemical 27]

In the above (3b-1), A ¹ represents a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) ₂ -, - O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -CH ₂ O-, -O-CH ₂ -, -COO-, -OCO-, -CO -N(CH ₃ )- or -N(CH ₃ )-CO-, m1 and m2 each independently represent an integer of 0 to 4, and m1+m2 is an integer of 1 to 4. In formula (3b-2), m3 and m4 each independently represent an integer of 1-5. In formula (3b-3), A ² is a straight-chain or branched alkyl group having 1 to 5 carbon atoms, and m5 represents an integer of 1 to 5. In formula (3b-4), A ³ and A ⁴ are each independently and represent a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) _2- , -O-, -CO-, -NH-, -N( _CH3 )-, -CONH-, -NHCO-, _-CH2O- , _-OCH2- , -COO-, -OCO -, -CO-N(CH ₃ )- or -N(CH ₃ )-CO-, m6 represents an integer of 1-4.

[Chemical 28]

In the above formulae (V-1) to (V-6), X ^v1 to X ^v4 , and X ^p1 to X ^p2 are each independent of each other and represent -(CH ₂ ) _a - (a is an integer of 1 to 15), -CONH -, -NHCO-, -CON( _CH3 )-, -NH-, -O-, _-CH2 -O-, _-CH2 -OCO-, -COO-, or -OCO-, X ^v5 represents -O -, _-CH2 -O-, _-CH2 -OCO-, -COO-, or -OCO-. X _a represents a single bond, -O-, -NH-, -O-(CH ₂ ) _m -O- (m represents an integer of 1 to 6), -C(CH ₃ ) ₂ -, -CO-, -( CH ₂ ) _m -, -SO ₂ -, -OC(CH ₃ ) ₂ -, -CO-(CH ₂ ) _m - (m represents an integer of 1 to 6), -NH-(CH ₂ ) _m -(m represents an integer from 1 to 6), -SO ₂ -(CH ₂ ) _m -(m represents an integer from 1 to 6), -CONH-(CH ₂ ) _m -(m represents an integer from 1 to 6), -CONH- (CH ₂ ) _m -NHCO- (m represents an integer of 1 to 6), -COO-(CH ₂ ) _m -OCO- (m represents an integer of 1 to 6), -CONH-, -NH- (CH ₂ ) _m -NH- (m represents an integer of 1 to 6), or -SO ₂ -(CH ₂ ) _m -SO ₂ - (m represents an integer of 1 to 6), R ^v1 to R ^v4 , and R ^1a to R ^1b Each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. In formula (V-6), two k may be the same or different.

[Chemical 29]

Examples of the nitrogen atom-containing heterocyclic ring include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridine, pyridine, indole, benzimidazole, purine, quinoline, isoquinoline, and pyridine, quinoline, pyridine, trisulfanium, carbazole, acridine, piperidine, piperidine, pyrrolidine, hexamethyleneimine, etc. Among them, pyridine, pyrimidine, pyridine, piperidine, piperidine, quinoline, carbazole, or acridine is preferable.

A diamine having a nitrogen atom-containing structure may also have a secondary amine group and a tertiary amine group, such as those represented by the following formula (n). [Chemical 30]

In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*" represents a bond with an atom bonded to a hydrocarbon group. Examples of the monovalent hydrocarbon group of R in the above formula (n) include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; and aryl groups such as phenyl and tolyl. R is preferably a hydrogen atom or a methyl group.

[化32]

[化33]

[化34]

式中，Py表示吡啶環或嘧啶環。 Specific examples of the diamine having a nitrogen atom-containing structure include, for example, 2,6-diaminepyridine, 3,4-diaminepyridine, 2,4-diaminepyrimidine, and 3,6-diaminecarbazole , N-methyl-3,6-diaminecarbazole, N-ethyl-3,6-diaminecarbazole, N-phenyl-3,6-diaminecarbazole, 1,4-bis-( 4-Aminophenyl)-piperidine, 3,6-diaminoacridine, compounds represented by the following formulae (Dp-1) to (Dp-8), or the following formulae (z-1) to (z The compound represented by -28). [Chemical 31]

[Chemical 32]

[Chemical 33]

[Chemical 34]

In the formula, Py represents a pyridine ring or a pyrimidine ring.

From the viewpoint of efficiently obtaining the effects of the present invention, in the polymer (A), the total content of the repeating unit (a1) and the imidized structure of the repeating unit (a1) is preferably 5 to 5 of all repeating units. 95 mol %, more preferably 5 to 90 mol %, still more preferably 5 to 80 mol %. In addition, the case where any one of the imidation structures of the repeating unit (a1) and the repeating unit (a1) is 0 mol% is also included in the total. Hereinafter, even if it is referred to as a total, the case where 1 or 2 or more of the constituent elements is 0 mol % is included. In addition, from the viewpoint of efficiently obtaining the effects of the present invention, the content of the repeating unit (a1) in the polymer (A) is preferably 5 to 95 mol % of all repeating units, more preferably 5 to 90 mol %. mol %, more preferably 5 to 80 mol %.

From the viewpoint of efficiently obtaining the effects of the present invention, the total content of the repeating unit (a2) and the imidized structure of the repeating unit (a2) in the polymer (A) is preferably 5 of all repeating units. -95 mol %, more preferably 10 - 95 mol %, still more preferably 20 - 95 mol %. In addition, from the viewpoint of efficiently obtaining the effects of the present invention, the content of the repeating unit (a2) in the polymer (A) is preferably 5 to 95 mol % of all repeating units, more preferably 10 to 10 mol %. 95 mol %, more preferably 20 to 95 mol %.

From the viewpoint of efficiently obtaining the effects of the present invention, in the polymer (A), the total content of the repeating unit (a1) and the repeating unit (a2) and the imidized structures thereof is preferably all repeating The unit is 10 mol% or more, more preferably 20 mol% or more, still more preferably 50 mol% or more, particularly preferably 80 mol% or more, and most preferably 90 mol% or more. When the polymer (A) contains repeating units (a1) and (a2) and repeating units other than those imidized structures, in the polymer (A), repeating units (a1) and (a2) And the total content of these imidized structures is preferably 95 mol % or less of all repeating units, more preferably 90 mol % or less. In addition, from the viewpoint of efficiently obtaining the effects of the present invention, in the polymer (A), the total content of the repeating unit (a1) and the repeating unit (a2) is preferably 10 mol% or more of all the repeating units , more preferably 20 mol % or more, still more preferably 50 mol % or more, particularly preferably 80 mol % or more, and most preferably 90 mol % or more. When the polymer (A) contains repeating units other than the repeating unit (a1) and the repeating unit (a2), the total content of the repeating unit (a1) and the repeating unit (a2) in the polymer (A) is preferably all repeating units 95 mol% or less, more preferably 90 mol% or less.

When the polymer (A) contains at least one of the repeating unit (a2') and the imidized structure of the repeating unit (a2'), from the viewpoint of efficiently obtaining the effects of the present invention, the polymer (A) ), the total content of the repeating unit (a2') and the imidized structure of the repeating unit (a2') is preferably 1 to 50 mol % of all repeating units, more preferably 1 to 40 mol %, More preferably, it is 1 to 30 mol %. In addition, when the polymer (A) contains the repeating unit (a2'), from the viewpoint of efficiently obtaining the effects of the present invention, it is preferable that all the repeating units (a2') contained in the polymer (A) repeat. The unit is 1 to 50 mol %, more preferably 1 to 40 mol %, and still more preferably 1 to 30 mol %.

When the polymer (A) contains at least one of the repeating unit (a3) and the imidized structure of the repeating unit (a3), from the viewpoint of efficiently obtaining the effects of the present invention, in the polymer (A) , the total content of the repeating unit (a3) and the imidized structure of the repeating unit (a3) is preferably 1 to 40 mol % of all repeating units, more preferably 1 to 30 mol %, and more preferably 1 to 25 mol%. When the polymer (A) contains the repeating unit (a3), from the viewpoint of efficiently obtaining the effects of the present invention, the repeating unit (a3) contained in the polymer (A) is preferably 1 to 1 of all the repeating units. 40 mol %, more preferably 1 to 30 mol %, still more preferably 1 to 25 mol %.

式中，X ₅為4價有機基，Y ₅為2價有機基。Z各自獨立，表示氫原子、可有取代基之碳數1～10之烷基、可有取代基之碳數2～10之烯基、可有取代基之碳數2～10之炔基、三級丁氧羰基、或9-茀甲氧羰基。R各自獨立，表示氫原子、或碳數為1～4之烷基。 <Polymer (B)> The liquid crystal aligning agent of the present invention may contain, in addition to the above-mentioned polymer (A), a polymer which does not have both the above-mentioned repeating unit (a1) and the above-mentioned repeating unit (a2) in the same molecule (B). From the viewpoint of efficiently obtaining the effects of the present invention, examples of the polymer (B) include polyimide precursors selected from the group consisting of repeating units represented by the following formula (5), and polyimide precursors as the polymer (B). The polymer of at least 1 type in the group which consists of the polyimide of the imide compound which is an amine precursor. [Chemical 35]

In the formula, X ₅ is a tetravalent organic group, and Y ₅ is a divalent organic group. Each Z independently represents a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted alkenyl group having 2 to 10 carbon atoms, an optionally substituted alkynyl group having 2 to 10 carbon atoms, Tertiary butoxycarbonyl, or 9-perylenemethoxycarbonyl. Each R independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

As the tetravalent organic group of the above _formula X5, a tetravalent organic group derived from an aliphatic tetracarboxylic dianhydride, a tetravalent organic group derived from an alicyclic tetracarboxylic dianhydride, or an aromatic Specific examples of the tetravalent organic group of the tetracarboxylic dianhydride include the tetravalent organic groups exemplified by X ₂ and X ₃ above. From the viewpoint of efficiently obtaining the effects of the present invention, X ₅ is preferably a tetravalent organic group represented by the above formula (g) or any one of the above formulas (X-1) to (X-25). A tetravalent organic group, a tetravalent organic group represented by the above formulae (Xa-1) to (Xa-2), or a tetravalent organic group represented by the above (Xr-1) to (Xr-7) (these are also collectively referred to as specific tetravalent organic group).

In the polymer (B), from the viewpoint of efficiently obtaining the effect of the present invention, X ₅ is the content of the repeating unit of the above-mentioned specific tetravalent organic group. mol% or more, more preferably 10 mol% or more.

As the divalent organic group of the above-mentioned Y ₅ , the above-mentioned divalent organic group exemplified by Y ₄ is exemplified. From the viewpoint of less image sticking due to residual DC, the polymer (B) preferably contains Y ₅ which is composed of the above-mentioned diamine having a urea bond, the above-mentioned diamine having an amide bond, and the above-mentioned nitrogen-containing atom. The structure of diamine, 2,4-diaminephenol, 3,5-diaminephenol, 3,5-diaminebenzyl alcohol, 2,4-diaminebenzyl alcohol, 4,6-diamineresorcinol . The above-mentioned diamine having a carboxyl group is a polymer obtained by removing the repeating unit of a divalent organic group having two amine groups (these are also collectively referred to as a specific divalent organic group).

In the polymer (B), the repeating unit in which Y ₅ is the above-mentioned specific tetravalent organic group may be 1 of all repeating units contained in the polymer (B) from the viewpoint of less image sticking due to residual DC. More than mol%, it can also be more than 5 mol%.

The content ratio of the polymer (A) to the polymer (B) is based on the mass ratio of [polymer (A)]/[polymer (B)] from the viewpoint of less image sticking due to residual DC , can be 10/90～90/10, can also be 20/80～90/10, can also be 20/80～80/20.

<The manufacturing method of polyamide acid, polyamide ester and polyimide> The polyimide precursors used in the present invention are polyimide esters, polyimide acids, and polyimide compounds thereof, that is, polyimide, for example, the known methods described in WO2013/157586 can be used. to be synthesized.

式[D-1]中，D ¹表示碳數1～3之烷基，式[D-2]中，D ²表示碳數1～3之烷基，式[D-3]中，D ³表示碳數1～4之烷基。 More specifically, it is synthesized by subjecting a diamine component and a tetracarboxylic acid derivative component to (polycondensation) reaction in a solvent. When a part of polymer (A) or polymer (B) contains an amide structure, for example, a polymer having an amide structure (polyamide) can be obtained by reacting a tetracarboxylic dianhydride component with a diamine component. amino acid). The solvent is not particularly limited as long as the produced polymer can be dissolved therein. Specific examples of the above-mentioned solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-bis Methylacetamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, butanone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the following formula [D-1] can be used to the solvent shown in [D-3]. [Chemical 36]

In formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, in formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D ³ Represents an alkyl group having 1 to 4 carbon atoms.

These solvents may be used alone or in combination, and even a solvent that does not dissolve the polymer may be used in combination with the above-mentioned solvent within the range in which the resulting polymer does not precipitate. When the diamine component and the tetracarboxylic acid derivative component are reacted in a solvent, the reaction can be performed at any concentration, but it is preferably 1 to 50 mass %, more preferably 5 to 30 mass %. The initial stage of the reaction is carried out at a high concentration, and a solvent may be added thereafter. In the reaction, the ratio of the total molar number of the diamine component to the total molar number of the tetracarboxylic acid derivative component is preferably 0.8 to 1.2. As in the general polycondensation reaction, as the molar ratio is closer to 1.0, the molecular weights of the produced polymer (A) and polymer (B) become larger.

Polyamic acid esters, for example, can be obtained by [I] a method of reacting a polyamic acid obtained by the above-mentioned method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, [ III] It can be obtained by a known method such as a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

As a method for obtaining polyimide, thermal imidization in which the polymer solution obtained by the above-mentioned reaction is directly heated, or catalytic imidization in which a catalyst is added to the polymer solution can be mentioned. The temperature during thermal imidization in the solution is 100-400°C, preferably 120-250°C, and the reaction is preferably performed while the water generated from the imidization reaction is excluded from the system.

For the imidization of the above catalyst, an alkaline catalyst and an acid anhydride can be added to the solution of the polymer obtained by the reaction, preferably at -20 to 250°C, more preferably at 0 to 180°C with stirring , for catalytic imidization. The amount of the alkaline catalyst is preferably 0.5 to 30 moles of the amide group, more preferably 2 to 20 moles, and the amount of the acid anhydride is preferably 1 to 50 moles of the amide group. , more preferably 3 to 30 moles. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable because the reaction proceeds but has a moderate basicity. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyrometic dianhydride, and the like, and among them, the use of acetic anhydride is preferred because the purification after completion of the reaction is facilitated. The imidization rate of catalyst imidization (the ratio of cyclized repeating units relative to all repeating units possessed by the polyimide precursor, also known as the cyclization rate) can be determined by the amount of catalyst and The reaction temperature and reaction time can be adjusted.

When recovering the produced imide compound from the above-mentioned imidization reaction solution, the reaction solution may be poured into a solvent and precipitated. Examples of the solvent used for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl selux, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, and the like. After the high molecular polymer precipitated in the solvent is collected by filtration, it can be dried at normal temperature or by heating under normal pressure or reduced pressure.

In the polyimide of the polymer (A) of the present invention, a part or all of the repeating units possessed by the above-mentioned polyimide precursor are cyclized. In the above-mentioned polyimide, the imidization rate is preferably 20 to 95%, more preferably 30 to 95%, still more preferably 50 to 95%.

<Solution viscosity and molecular weight of polymer> When the polyamic acid, polyamic acid ester and polyimide used in the present invention are prepared as a solution having a concentration of 10 to 15 mass %, for example, from the viewpoint of workability, it is preferable to have 10 ~1000mPa. The solution viscosity of s is not particularly limited. In addition, the solution viscosity (mPa·s) of the above-mentioned polymer is prepared by using a good solvent for the polymer (eg γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) to prepare a concentration of 10-15% by mass. polymer solution, and the value measured at 25°C using an E-type rotational viscometer. The weight-average molecular weight (Mw) of the above-mentioned polyamic acid, polyamic acid ester and polyimide measured by gel chromatography (GPC) in terms of polystyrene is preferably 1,000-500,000, and more It is preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn) is represented by the ratio of Mw to the number average molecular weight (Mn) converted from polystyrene measured by GPC, and is preferably 15 or less, more preferably 10 or less. In such a molecular weight range, favorable alignment and stability of the liquid crystal display element can be ensured.

＜Capping agent＞ When synthesizing the polymer (A) and the polymer (B) of the present invention, as described above, an appropriate end-capping agent can be used together with a tetracarboxylic acid derivative and a diamine component to synthesize an end-capping type polymer. The end-capped polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by the coating film, or improving the adhesion characteristics between the sealant and the liquid crystal alignment film. As an example of the terminal of the polymer (A) and the polymer (B) of this invention, an amine group, a carboxyl group, an acid anhydride group, or these derivatives are mentioned. An amine group, a carboxyl group, an acid anhydride group, or a terminal group derived from these groups can be obtained by a general condensation reaction, or can be obtained by capping the terminal with the following end-capping agent, for example, using the following end-capping agent , the aforementioned derivatives can be obtained in the same way.

Examples of the end-capping agent include acetic anhydride, maleic anhydride, nadic acid anhydride, phthalic anhydride, itaconic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride Formic anhydride, trimellitic anhydride, 3-(3-(trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroiso Acid anhydrides such as benzofuran-1,3-dione, 4-ethynylphthalic anhydride, etc.; Dicarbonate diester compounds such as bis(tertiary butyl) dicarbonate, diallyl dicarbonate, etc.; Acryloyl chloride , chlorocarbonyl compounds such as methacryloyl chloride, nicotinic acid chloride; , 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine and other monoamine compounds; Monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, and naphthyl isocyanate, etc.

The use ratio of the terminal blocking agent is preferably 0.01 to 20 mol parts, more preferably 0.01 to 10 mol parts, with respect to 100 mol parts of the total of the diamine components used.

<Liquid crystal alignment agent> The liquid crystal aligning agent of the present invention contains the polymer (A) and the polymer (B) as required. The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polymer (A) and the polymer (B). Examples of other polymers include polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene or derivatives thereof, poly(styrene-phenylene) maleimide) derivatives, poly(meth)acrylates, etc.

The liquid crystal alignment agent is used to make a liquid crystal alignment film, and from the viewpoint of forming a uniform thin film, it is in the form of a coating liquid. Among the liquid crystal aligning agents of the present invention, a coating liquid containing the above-mentioned polymer component and an organic solvent is preferable. At this time, the polymer concentration in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, the polymer concentration is preferably 1 mass % or more, and from the viewpoint of solution storage stability, the polymer concentration is preferably 10 mass % or less. A particularly preferred polymer concentration is 2 to 8 mass %.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as the polymer component can be uniformly dissolved therein. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, butanone, cyclohexanone, cyclopentanone Ketone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N-(n-propyl)-2-pyrrolidone, N- Isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tertiarybutyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxy propyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (also collectively referred to as "good solvent" )Wait. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N- Dimethylpropionamide, or gamma-butyrolactone. The content of the good solvent is preferably 20 to 99 mass % of the entire solvent contained in the liquid crystal aligning agent, more preferably 20 to 90 mass %, and particularly preferably 30 to 80 mass %.

In addition, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent, and the mixed solvent is in addition to the above-mentioned solvent and can improve the coating property or the surface smoothness of the coating film when coating the liquid crystal aligning agent. solvent (also known as poor solvent). The content of the poor solvent is preferably 1 to 80 mass % of the entire solvent contained in the liquid crystal aligning agent, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %. The type and content of the poor solvent are appropriately selected according to the coating apparatus of the liquid crystal aligning agent, coating conditions, coating environment, and the like. The specific example of the poor solvent used together is as follows, but it is not limited to this. For example, diisopropyl ether, diisobutyl ether, diisobutyl methanol (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-methyl amyl acetate, 2-ethyl butyl acetate, 2-ethyl hexyl acetate Esters, Ethylene Glycol Monoacetate, Ethylene Glycol Diacetate, Propylene Carbonate, Ethylene Carbonate, Ethylene Glycol Monobutyl Ether (Butyl Cyrus), Ethylene Glycol Monoisoamyl Ether, Ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol Monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol 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 Ester, 3-methoxybutyl propionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone) Wait.

Among them, preferred are 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.

Preferred combinations of the good solvent and the poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol Butyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with 4 -Hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl- 2-Pyrrolidone and ethyl 3-methoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-methoxypropionate, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether Ester, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol Diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2- Pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4 -Hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether , N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2- Pentanone and propylene glycol diacetate, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl- 2-Pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butane Lactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl methanol, N-methyl-2-pyrrolidone With γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether With dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2-pyrrolidone and N,N-dimethyl lactamide and diisobutyl ketone, etc.

The liquid crystal aligning agent of the present invention may additionally contain components other than the polymer component and the organic solvent (hereinafter also referred to as additive components). Examples of such additive components include adhesion aids for improving the adhesion between a liquid crystal alignment film and a substrate, or adhesion between a liquid crystal alignment film and a sealant, and an adhesion aid for improving the strength of the liquid crystal alignment film. Compounds (hereinafter also referred to as cross-linking compounds), dielectrics or conductive substances used to adjust the permittivity or resistance of liquid crystal alignment films.

式(d)中，R ₂及R ₃各自獨立，為氫原子、碳數1～3之烷基或「＊-CH ₂-OH」。＊表示原子鍵結。式(e)中，A表示具有芳香環之(m+n)價有機基，R表示氫原子或碳數1～5之烷基，m表示1～6之整數，n表示0～4之整數。上述芳香環上的任意氫原子，可被鹵素原子、碳數為1～10之烷基、碳數2～10之烯基、碳數1～10之烷氧基、碳數1～10之氟烷基、碳數2～10之氟烯基、或碳數1～10之氟烷氧基取代。 From the viewpoint of showing good resistance to AC image sticking and high improvement in film strength, the crosslinkable compound may be selected from a compound having the following group and a compound represented by the following formula (e). At least one compound in the formed group, wherein the group is selected from the group consisting of oxirane group, oxetanyl group, protected isocyanate group, protected isothiocyanate group, and a group comprising an oxazoline ring structure , a group comprising at least one of the group consisting of a Michaelis acid structure group, a cyclocarbonate group, and a group represented by the following formula (d). [Chemical 37]

In formula (d), R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or "*-CH ₂ -OH". * Indicates atomic bonding. In formula (e), A represents an (m+n) valent organic group having an aromatic ring, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, m represents an integer of 1 to 6, and n represents an integer of 0 to 4 . Any hydrogen atom on the above-mentioned aromatic ring may be replaced by a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a fluorine group having 1 to 10 carbon atoms. Substituted with an alkyl group, a fluoroalkenyl group having 2 to 10 carbon atoms, or a fluoroalkoxy group having 1 to 10 carbon atoms.

Specific examples of the compound having an oxirane group include compounds having two or more oxirane groups, such as the compound described in paragraph [0037] of Japanese Patent Laid-Open No. 10-338880, or WO2017 The compound etc. which have a triazabenzene ring in a structure as described in Gazette/170483. Among these compounds, it can also be N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylamine (methyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminediphenylmethane, N,N,N',N'-tetraglycidyl - A nitrogen atom-containing compound such as p-phenylenediamine and a compound represented by the following formulae (r-1) to (r-3). [Chemical 38]

As a specific example of the compound which has an oxetanyl group, the compound etc. which have two or more oxetanyl groups which are described in the paragraphs [0170] to [0175] of WO2011/132751 are mentioned.

Specific examples of the compound having a protected isocyanate group include the compounds having two or more protected isocyanate groups described in paragraphs [0046] to [0047] of Japanese Patent Laid-Open No. 2014-224978, and those disclosed in WO2015/141598 The compounds and the like described in paragraphs [0119] to [0120] having two or more protected isocyanate groups may also be compounds represented by the following formulae (bi-1) to (bi-3). [Chemical 39]

As a specific example of the compound which has a protected isothiocyanate group, the compound which has two or more protected isothiocyanate groups described in Unexamined-Japanese-Patent No. 2016-200798 is mentioned. As a specific example of the compound which has a group containing an oxazoline ring structure, the compound containing two or more oxazoline ring structures described in the paragraph [0115] of Unexamined-Japanese-Patent No. 2007-286597 is mentioned.

As a specific example of the compound which has a group containing a Michaelis acid structure, the compound which has two or more Michaelis acid structures as described in WO2012/091088 gazette is mentioned. Specific examples of the compound having a cyclocarbonate group include the compounds described in WO2011/155577. The group represented by the above formula (d) includes a methyl group, an ethyl group, a propyl group, and an isopropyl group as the alkyl group having 1 to 3 carbon atoms in R ₂ and R ₃ .

Specific examples of the compound having a group represented by the above formula (d) include those described in paragraph [0058] of WO2015/072554 A, or Japanese Patent Laid-Open No. 2016-118753, having two or more of the above formula (d). ), the compounds described in Japanese Patent Laid-Open No. 2016-200798, and the like may also be compounds represented by the following (hd-1) to (hd-8). [Chemical 40]

Examples of the (m+n)-valent organic group having an aromatic ring in A of the above formula (e) include (m+n)-valent aromatic hydrocarbon groups having 6 to 30 carbon atoms, and aromatic groups having 6 to 30 carbon atoms. The hydrocarbon group is a (m+n)-valent organic group bonded directly or via a linking group, and an (m+n)-valent organic group having an aromatic heterocyclic ring. As said aromatic hydrocarbon group, benzene, naphthalene, etc. are mentioned, for example. Examples of the aromatic heterocyclic ring include a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, an isoquinoline ring, a carbazole ring, a pyridoxine ring, a pyridine ring, and a benzimidazole. ring, indole ring, quinoline ring, acridine ring, etc. Examples of the linking group include an alkylene group having 1 to 10 carbon atoms, a group obtained by removing one hydrogen atom from the above-mentioned alkylene group, a divalent or trivalent cyclohexane ring, and the like. In addition, any hydrogen atom of the above-mentioned alkylene group may be substituted with an organic group such as an alkyl group having 1 to 6 carbon atoms, a fluorine atom, or a trifluoromethyl group. Specific examples of the alkyl group represented by R ₁ to R ₄ in the above formula (1) as the alkyl group having 1 to 5 carbon atoms in R in the above formula (e) can be given. Specific examples of the above formula (e) include compounds described in WO2010/074269 and compounds represented by the following formulae (e-1) to (e-10). [Chemical 41]

The above-mentioned compound is an example of a crosslinkable compound, but it is not limited to this. For example, components other than the above-mentioned components disclosed in pages 53 [0105] to 55 [0116] of WO2015/060357 A can be mentioned. Moreover, you may combine 2 or more types of crosslinkable compounds. In the liquid crystal aligning agent of the present invention, the content of the crosslinkable compound is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, because the crosslinking reaction is carried out and the AC residual image is exhibited well. From the viewpoint of resistance, it is more preferably 1 to 15 parts by mass.

As said adhesion adjuvant, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyl are mentioned, for example Trimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- Aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N- Ethoxycarbonyl-3-aminopropyltriethoxysilane, N-(3-triethoxysilylpropyl)triethylenetetramine, N-(3-trimethoxysilylpropyl)triethylenetetramine Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl -3,6-diazanonylacetate, 9-triethoxysilyl-3,6-diazepine acetate, N-benzophenone-3-aminopropyltrimethoxy Silane, N-Dibenzophenone-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane Silane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldisilane Methoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane , p-styrene trimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxy Propylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-propenyloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl) Silane coupling agent for isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc. When using a silane coupling agent, from the viewpoint of showing good resistance to AC afterimages, the silane coupling agent is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more Preferably, it is 0.1-20 mass parts.

<Liquid crystal alignment film, liquid crystal display element> The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used for horizontal alignment type or vertical alignment type (VA type) liquid crystal alignment film, wherein the liquid crystal alignment film of the present invention is suitable for horizontal alignment type liquid crystal display elements such as IPS mode or FFS mode. . Furthermore, it is preferable to use a liquid crystal alignment film by a photo-alignment treatment method. The liquid crystal display element of the present invention is provided with the above-mentioned liquid crystal alignment film. The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (3) and (5), or steps (1) to (2) and (5). More preferably, it is produced by a method including steps (1) to (5).

<Step (1): The step of coating the liquid crystal alignment agent on the substrate> On one side of the substrate provided with the patterned transparent conductive film, the liquid crystal aligning agent of the present invention is applied by an appropriate coating method such as a roll coating method, a spin coating method, a printing method, and an inkjet method. cloth. Here, the substrate is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as acrylic substrates and polycarbonate substrates can be used together with glass substrates and silicon nitride substrates. In addition, if the reflective liquid crystal display element has only a single-sided substrate, an opaque material such as a silicon wafer can also be used. In this case, a material that reflects light such as aluminum can also be used as the electrode. In addition, when manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with electrodes and a counter substrate not provided with electrodes are used, wherein the electrodes are formed from a patterned transparent conductive film or a comb-like shape. made of metal film.

As a method of applying a liquid crystal aligning agent to a substrate and forming a film, screen printing, offset printing, flexographic printing, inkjet method, spray method, etc. are mentioned. Among them, coating and film-forming methods by an inkjet method are preferably used.

<Step (2): Step of calcining the coated liquid crystal alignment agent> Step (2) is a step of calcining 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 heating plate, a thermal cycle oven or an IR (infrared) oven, and the heating of the polyamic acid and polyamic acid ester can be carried out. imidization. The drying and calcining steps after coating the liquid crystal aligning agent of the present invention may be performed at any temperature and time, and may be performed several times. As the temperature at which the liquid crystal aligning agent is fired, for example, it can be carried out at 40 to 180°C. From a viewpoint of shortening a process, it can also carry out at 40-150 degreeC. The calcination time is not particularly limited, and may be 1 to 10 minutes, or 1 to 5 minutes. When thermal imidization of polyamic acid and polyamic acid ester is performed, after the above-mentioned calcination step, the calcination step can be performed, for example, in a temperature range of 150 to 300°C or 150 to 250°C. The calcination time is not particularly limited, and may be 5 to 40 minutes, or 5 to 30 minutes. If the film-like material after firing is too thin, the reliability of the liquid crystal display element may be lowered, so it is preferably 5 to 300 nm, more preferably 10 to 200 nm.

<Step (3): The step of aligning the film obtained in the step (2)> Step (3) is a step of performing alignment treatment on the film obtained in step (2) according to the situation. That is, in the case of a horizontal alignment type liquid crystal display element such as an IPS method or an FFS method, the coating film is subjected to a treatment for imparting alignment ability. On the other hand, in the case of a vertical alignment type liquid crystal display element such as a VA mode or a PSA mode, the formed coating film may be used as a liquid crystal alignment film as it is, but the coating film may be treated to impart alignment ability. As the alignment treatment method of the liquid crystal alignment film, a rubbing alignment treatment method and a photo-alignment treatment method can be mentioned, and the photo-alignment treatment method is more suitable. As a photo-alignment treatment method, the surface of the above-mentioned film is irradiated with radiation deviated in a certain direction. Depending on the situation, it is preferable to perform a heat treatment at a temperature of 150 to 250° C. to impart liquid crystal alignment (also known as is the method of liquid crystal alignment ability). As the radiation, ultraviolet rays or visible light having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and more preferred are wavelengths of 200 to 400 nm.

The irradiation dose of the above-mentioned radiation is preferably 1 to 10,000 mJ/cm ² , more preferably 100 to 5,000 mJ/cm ² , still more preferably 100 to 1,500 mJ/cm ² , particularly preferably 100 to 1,000 mJ/cm ² , and more preferably 100 to 400 mJ/cm ² . When a general liquid crystal alignment agent is used, the light irradiation amount for the alignment treatment is 100-5,000 mJ/cm ² , but in the liquid crystal alignment agent of the present invention, even if the light irradiation amount for the alignment treatment is reduced, the liquid crystal alignment film can still be obtained. A liquid crystal alignment film in which variation (non-uniformity) of liquid crystal alignment in the plane is suppressed. In addition, when irradiating radiation, in order to improve liquid crystal alignment, you may irradiate the board|substrate which has the said film-like object, heating it at 50-250 degreeC. The above-mentioned liquid crystal alignment film produced in this way can stably align liquid crystal molecules in a certain direction. Furthermore, by the above-mentioned method, the liquid crystal alignment film irradiated with polarized radiation may be subjected to contact treatment using water or a solvent, or the liquid crystal alignment film irradiated with radiation may be subjected to heat treatment.

The solvent used for the above-mentioned contact treatment is not particularly limited as long as the solvent dissolves the decomposed product formed from the film-like substance by irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, butanone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl Cylusu, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. Among them, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred from the viewpoint of universality and safety of the solvent. More preferably, it is water, 1-methoxy-2-propanol, or ethyl lactate. One type of solvent may be used, or two or more types may be combined.

<Step (4): The step of performing heat treatment at 50 to 300° C. on the alignment-treated film in Step (3)> The coating film irradiated with the above-mentioned radiation can be heat-treated. It is preferable that it is 50-300 degreeC, and, as for the temperature at which the coating film irradiated with the said radiation is heat-processed, it is more preferable that it is 120-250 degreeC. As time of heat treatment, it is preferable to set it as each 1 to 30 minutes.

<Step (5): Step of making liquid crystal cells> Two substrates on which the liquid crystal alignment film was formed as described above were prepared, and liquid crystal was arranged between the two substrates arranged to face each other. Specifically, the following two methods can be mentioned. In the first method, first, individual liquid crystal alignment films are brought into a facing state, and two substrates are arranged to face each other with a gap (cell gap) therebetween. Next, the peripheries of the two substrates were bonded together using a sealant, and the liquid crystal composition was injected and filled in the cell gap separated by the substrate surface and the sealant, and after contacting the film surface, the injection hole was sealed.

In addition, the second method is a method called a drop-drop liquid crystal injection method (ODF, One Drop Fill). For example, a UV curable sealant is applied to a specific place on one of the two substrates forming the liquid crystal alignment film, and then the liquid crystal composition is dropped onto specific places on the surface of the liquid crystal alignment film. After that, another substrate is bonded to make the liquid crystal alignment film in a state corresponding to the surface, and the liquid crystal composition is pressed and scattered until the entire surface of the substrate is in contact with the film surface. Then, the entire surface of the substrate is irradiated with ultraviolet light to harden the encapsulant. Regardless of the method, it is further preferable to remove the flow alignment during liquid crystal filling by heating the liquid crystal composition to be used to a temperature at which it becomes a homogeneous phase, and then gradually lowering the temperature to room temperature. In addition, when rubbing the coating film, the rubbing directions of the coating films of the two substrates are arranged to correspond to each other at a specific angle, for example, perpendicular or anti-parallel. As a sealant, epoxy resin containing alumina balls as a hardener and a spacer, for example, can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals, and among them, nematic liquid crystals are preferred.

In addition, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as required. As the polarizing plate attached to the outer surface of the liquid crystal cell, there can be mentioned a polarizing film called "H film", which can absorb iodine while extending and aligning polyvinyl alcohol, and a polarizing film sandwiched by a cellulose acetate protective film. plate or a polarizing plate composed of the H film itself.

The IPS substrate of the comb-tooth electrode substrate used in the IPS (In-Plane Swithcing) mode has a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-like shape, and covered with lines on the substrate. A liquid crystal alignment film formed like an electrode. In addition, the FFS substrate of the comb-teeth electrode substrate used in the FFS (Frindge Field Switching) mode has a substrate, a surface electrode formed on the substrate, an insulating film formed on the surface electrode, and an insulating film formed on the insulating film. A plurality of linear electrodes arranged in a comb-like shape, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

FIG. 1 is a schematic cross-sectional view showing one example of a lateral electric field liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element. In the lateral electric field liquid crystal display element 1 illustrated in FIG. 1 , the liquid crystal 3 is sandwiched between the comb-teeth electrode substrate 2 including the liquid crystal alignment film 2c and the counter substrate 4 including the liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-like shape, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. . The opposing substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also the liquid crystal alignment film of the present invention. In this lateral electric field liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, as indicated by lines of electric force L, an electric field is generated between the linear electrodes 2b.

2 is a schematic cross-sectional view showing another example of the lateral electric field liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element. In the lateral electric field liquid crystal display element 1 illustrated in FIG. 2 , the liquid crystal 3 is sandwiched between the comb-teeth electrode substrate 2 provided with the liquid crystal alignment film 2h and the counter substrate 4 provided with the liquid crystal alignment film 4a. The comb-teeth electrode substrate 2 has a base material 2d, a surface electrode 2e formed on the base material 2d, an insulating film 2f formed on the surface electrode 2e, and a plurality of linear electrodes formed on the insulating film 2f and arranged in a comb-like shape 2g. A liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The opposing substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention. In this lateral electric field liquid crystal display element 1, when a voltage is applied to the surface electrodes 2e and the linear electrodes 2g, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g as indicated by the lines of force L. [Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The following compound abbreviations and the measurement methods of each characteristic are as follows.

「Boc」表示三級丁氧基羰基。「Me」表示甲基。 (Vehicle) NMP: N-Methyl-2-pyrrolidone BCS: Butyl Seluzol (diamine) DA-1: p-phenylenediamine DA-2: 1,2-bis(4-aminophenoxy)ethyl Alkane DA-3: Please refer to the following formula (DA-3) DA-4: Please refer to the following formula (DA-4) DA-5: 4,4'-diamino-2,2'-dimethyldicarbonate Benzene DA-6: 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl DA-7: 1,3-bis(4-aminophenethyl)urea DA-8 : 4-(2-methylaminoethyl)aniline (acid dianhydride) TA-1: 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride TA-1: 1,2,3,4-Cyclobutanetetracarboxylic dianhydride[Chem.42]

"Boc" represents a tertiary butoxycarbonyl group. "Me" represents a methyl group.

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

[Synthesis example of polymer] <Synthesis example 1> In a 200mL four-necked flask with a stirring device and a nitrogen inlet tube, measure 0.87g (8.0 mmol) of DA-1, 2.93g (12.0 mmol) of DA-2, and 3.84g (12.0 mmol) of DA-3 , and 3.19 g (8.0 mmol) of DA-4, and 128.3 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 8.61 g (38.4 mmol) of TA-1 was added, and NMP was added to make the solid content concentration 12% by mass, and the solution was stirred at 40° C. for 20 hours to obtain a polyamic acid solution ( PAA-1). The viscosity of the polyamide acid solution is 394mPa. s.

<Synthesis example 2> In a 50mL four-necked flask with a stirring device and a nitrogen inlet tube, measure 0.61g (2.5 mmol) of DA-2 and 0.53g (2.5 mmol) of DA-5, then add 16.2g of NMP, while feeding It was dissolved with stirring under nitrogen. While stirring this diamine solution, 1.06 g (4.7 mmol) of TA-1 was added, and the mixture was stirred at 50° C. for 16 hours to obtain a polyamic acid solution (PAA-2). The viscosity of the polyamide acid solution is 245mPa. s.

<Synthesis example 3> In a 50mL four-necked flask with a stirring device and a nitrogen inlet tube, measure 0.49g (2.0 mmol) of DA-2 and 0.64g (2.0 mmol) of DA-6, then add 14.5g of NMP, while feeding It was dissolved with stirring under nitrogen. While stirring the diamine solution, 0.88 g (3.9 mmol) of TA-1 was added, and the mixture was stirred at 50° C. for 16 hours to obtain a polyamic acid solution (PAA-3). The viscosity of the polyamide acid solution is 95mPa. s.

<Synthesis Example 4> In a 500mL four-necked flask with a stirring device and a nitrogen inlet tube, measure 9.01g (60.0 mmol) of DA-8 and 26.8g (89.8 mmol) of DA-7, then add 290g of NMP, while feeding nitrogen Stir to dissolve. While stirring the diamine solution in a water-cooled state, 27.9 g (142 mmol) of TA-2 was added, and 71.4 g of NMP was added, followed by stirring at 23° C. for 2 hours to obtain a polyamic acid solution (PAA-4 ). The viscosity of the polyamide acid solution is 750mPa. s.

[Preparation of liquid crystal alignment agent] <Example 1> 6.25 g of the 12 mass % polyamide acid solution (PAA-3) obtained in Synthesis Example 3 was put into a 20 mL Erlenmeyer flask, 5.75 g of NMP and 3.00 g of BCS were added, and the mixture was mixed at 25° C. for 2 hours. A liquid crystal aligning agent (A1) was obtained. Abnormal phenomena such as turbidity and precipitation were not found in the liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a homogeneous solution.

<Example 2> Take 1.25 g of the 12 mass % polyamic acid solution (PAA-3) obtained in Synthesis Example 3, and take 2.33 g of the 15 mass % polyamic acid solution (PAA-4) obtained in Synthesis Example 4, and put them in Into a 20 mL Erlenmeyer flask, 4.42 g of NMP and 2.00 g of BCS were added, and the mixture was mixed at 25° C. for 2 hours to obtain a liquid crystal aligning agent (A2). Abnormal phenomena such as turbidity and precipitation were not found in the liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a homogeneous solution.

<Comparative Example 1> 7.50 g of the 12 mass % polyamide acid solution (PAA-1) obtained in Synthesis Example 1 was put into a 20 mL Erlenmeyer flask, 5.10 g of NMP and 5.40 g of BCS were added, and the mixture was mixed at 25° C. for 2 hours. A liquid crystal aligning agent (B1) was obtained. Abnormal phenomena such as turbidity and precipitation were not found in the liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a homogeneous solution.

<Comparative Example 2> 4.16 g of the 12 mass % polyamide acid solution (PAA-2) obtained in Synthesis Example 2 was put into a 20 mL Erlenmeyer flask, 3.83 g of NMP and 2.00 g of BCS were added, and the mixture was mixed at 25° C. for 2 hours. A liquid crystal aligning agent (B2) was obtained. Abnormal phenomena such as turbidity and precipitation were not found in the liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a homogeneous solution.

<Comparative Example 3> Take 1.25 g of the 12 mass % polyamide solution (PAA-2) obtained in Synthesis Example 2, and take 2.33 g of the 15 mass % polyamide solution (PAA-4) obtained in Synthesis Example 4, and put Into a 20 mL Erlenmeyer flask, 4.42 g of NMP and 2.00 g of BCS were added, and the mixture was mixed at 25° C. for 2 hours to obtain a liquid crystal aligning agent (B3). Abnormal phenomena such as turbidity and precipitation were not found in the liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a homogeneous solution.

[Table 1] Liquid crystal alignment agent mixed polymer Mixing Ratio (Mass Ratio) Component 1: Component 2 Solution composition (mass %) Ingredient 1 Ingredient 2 polymer NMP BCS Example 1 A1 PAA-3 100:0 5 75 20 Example 2 A2 PAA-3 PAA-4 30:70 5 75 20 Comparative Example 1 B1 PAA-1 100:0 5 65 30 Comparative Example 2 B2 PAA-2 100:0 5 75 20 Comparative Example 3 B3 PAA-2 PAA-4 30:70 5 75 20

Using the liquid crystal aligning agent obtained as described above, FFS-driven liquid crystal cells were produced in the procedure shown below, and characteristics were evaluated.

[Production of Liquid Crystal Cells] A liquid crystal cell with a fringe field switching (FFS) mode liquid crystal display element structure was fabricated. First, a substrate with electrodes is prepared. The substrate is a glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. On the substrate, as the first layer, an ITO electrode is formed, and the ITO electrode constitutes a counter electrode and has a solid thin film-like pattern. On the counter electrode of the first layer, a SiN (silicon nitride) film is formed as a second layer by a CVD method. The film thickness of the second SiN film is 500 nm, which is a film thickness that functions as an interlayer insulating film. On the second SiN film, as the third layer, a comb-shaped pixel electrode formed by patterning the ITO film was arranged, and two pixels of the first pixel and the second pixel were formed. The size of each pixel is 6 mm in length and about 5 mm in width. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the function of the SiN film of the second layer.

The pixel electrode of the third layer is formed by arranging a plurality of electrode parts with an inner angle of 160° bent into a "ㄑ" shape in the central part, and has a comb-like shape. The width in the short-side direction of each electrode part was 3 μm, and the interval between the electrode parts was 6 μm. The pixel electrodes that form each pixel are composed of electrode parts with a plurality of curved "ㄑ"-shaped electrode parts arranged in the central part. The shape of each pixel is not a rectangle, but is the same as the electrode parts. Similar to the bold "ㄑ" shape. In addition, each pixel is divided into upper and lower sides with the curved portion in the center as a boundary, and has a first area on the upper side of the curved portion and a second area on the lower side.

Next, the liquid crystal aligning agent was filtered through a filter with a pore size of 1.0 μm, and then applied by spin coating on the prepared substrate (first glass substrate) with the above-mentioned electrodes and an ITO film formed on the back with a height of On the glass substrate (second glass substrate) of the 4 μm columnar spacer. After drying on a hot plate at 80°C for 2 minutes, calcination was performed in a hot air circulation oven at 230°C for 30 minutes to form a coating film with a thickness of 100 nm. The polarizing plate is irradiated with linearly polarized light with an extinction ratio of 10:1 and a wavelength of 254 nm at 150-300 mJ/cm ² on the coating film surface. In addition, the alignment process of the liquid crystal alignment film formed on the first glass substrate is performed in such a way that the direction of the inner angle of the pixel bending angle is equally divided and the alignment direction of the liquid crystal to be vertical, and the liquid crystal alignment film formed on the second glass substrate is The alignment treatment is performed so that the alignment direction of the liquid crystal on the first glass substrate and the alignment direction of the liquid crystal on the second glass substrate are the same when the liquid crystal cell is produced. The substrate was fired in a hot air circulation oven at 230° C. for another 30 minutes to obtain a substrate with a liquid crystal alignment film. The above-mentioned two substrates were used as one set, the sealant was printed on the substrate, and the other substrate was attached so that the alignment direction facing the liquid crystal alignment film surface was 0°, and then the sealant was cured to produce Empty unit cell. Liquid crystal MLC-3019 (manufactured by Merck Co., Ltd.) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Then, the obtained liquid crystal cell was heated at 110 degreeC for 1 hour, and was used for various evaluation methods after leaving to stand overnight.

[Afterimage evaluation due to long-term communication drive] Using the above-mentioned liquid crystal cell, AC voltage of ±5V was applied at a frequency of 60Hz for 120 hours under a constant temperature environment of 60°C. After that, the liquid crystal cell was left in a short-circuit state between the pixel electrode and the counter electrode, and was left at room temperature for one day. After standing for one day, set up a liquid crystal cell between two polarizers with the polarizing axis perpendicular to each other, light the backlight in advance without applying voltage, and adjust the angle of the liquid crystal cell to minimize the brightness of the transmitted light. Then, the rotation angle of the liquid crystal cell from the angle at which the second area of the first pixel becomes the darkest to the angle at which the first area of the first pixel becomes the darkest is calculated as the angle Δ. The same is true for the second pixel, and the same angle Δ is calculated by comparing the second area and the first area. The average value of the angle Δ is calculated using the angle Δ calculated by the first pixel and the angle Δ calculated by the second pixel.

[Evaluation of in-plane uniformity of liquid crystal alignment] The twist angle evaluation of the liquid crystal display element was performed using OPTIPRO-micro manufactured by SHINTEC Co., Ltd. The produced liquid crystal cell was placed on a measuring stand, and in a state where no voltage was applied, 20 points were measured in the first pixel plane, and the standard deviation was calculated. The evaluation was carried out according to the following definitions. When the standard variation of the torsion angle was 0.35 or more, it was regarded as "defective", and when it was less than 0.35, it was regarded as "good".

＜Evaluation results＞ Table 2 shows the evaluation results of the liquid crystal display elements obtained using the liquid crystal aligning agents (A1) to (A2) and (B1) to (B3) obtained in Examples 1 to 2 and Comparative Examples 1 to 3 above. .

[Table 2] Liquid crystal alignment agent mixed polymer Mixing Ratio (Mass Ratio) Component 1: Component 2 Cumulative amount of UV light (mJ/cm ² ) Image sticking due to long-term AC drive (angle Δ of liquid crystal cell) In-plane uniformity of liquid crystal alignment Ingredient 1 Ingredient 2 Example 1 A1 PAA-3 100:0 150 0.13 good Comparative Example 1 B1 PAA-1 100:0 0.15 bad Comparative Example 2 B2 PAA-2 100:0 0.15 bad Example 2 A2 PAA-3 PAA-4 30:70 300 0.20 Comparative Example 3 B3 PAA-2 PAA-4 30:70 0.24

From the comparison between Example 1 and Comparative Examples 1 and 2, it can be seen that the composition contains 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl and 1,2-bis(4-amine) Compared with the liquid crystal alignment agent A1 containing polyamic acid (PAA-3) synthesized from the diamine component of phenyloxy)ethane, compared with the liquid crystal containing polyamic acid synthesized from the diamine component that does not contain both diamines For the alignment agents B1 and B2, the residual image caused by long-term AC driving is relatively small, and the in-plane uniformity of the liquid crystal alignment is relatively high. In this way, it is known that by introducing a biphenyl group in which a hydrogen atom is substituted with a halogenated alkyl group into a polymer main chain, it is known that a liquid crystal alignment that is excellent in image sticking due to long-term AC driving and is excellent in in-plane uniformity of liquid crystal alignment can be obtained. agent. Furthermore, from the comparison between Example 2 and Comparative Example B3, it can be seen that the inclusion of 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl and 1,2-bis(4-amino) The liquid crystal alignment agent, which is a mixture of polyamides synthesized from diamine components of phenoxy)ethane and other polyamides, can also improve the afterimage caused by long-term AC driving. [Industrial use possibility]

By using the liquid crystal alignment agent of the present invention, in the liquid crystal display elements of IPS and FFS driving modes, the image sticking caused by long-term AC driving can be suppressed, and a liquid crystal alignment film with high contrast in-plane uniformity can be obtained. . Therefore, it can be expected to be utilized in liquid crystal display elements that pursue high-level display levels.

1: Lateral electric field liquid crystal display element 2: Comb-tooth electrode substrate 2a: Substrate 2b: Wire Electrode 2c: Liquid crystal alignment film 2d: Substrate 2e: Surface electrode 2f: insulating film 2g: wire electrode 3: LCD 4: Opposite substrate 4a: Liquid crystal alignment film 4b: Substrate 4c: Liquid crystal alignment film L: power line

FIG. 1 is a schematic cross-sectional view showing an example of the lateral electric field liquid crystal display element of the present invention. 2 is a schematic cross-sectional view showing another example of the transverse electric field liquid crystal display element of the present invention.

1: Lateral electric field liquid crystal display element

2: Comb-tooth electrode substrate

2a: Substrate

2b: Wire Electrode

2c: Liquid crystal alignment film

3: LCD

4: Opposite substrate

4a: Liquid crystal alignment film

4b: Substrate

L: power line

Claims (15)

A liquid crystal aligning agent characterized by containing a polymer (A) selected from the group consisting of a repeating unit (a1) represented by the following formula (1) and a repeating unit (a1) represented by the following formula (2). a2) at least one polymer in the group consisting of the polyimide precursor and the polyimide compound of the polyimide precursor as the polyimide precursor;

In formula (1), R ₁ to R ₄ are each independently and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkynyl group having 2 to 6 carbon atoms. , a monovalent organic group with 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, at least one of R ₁ to R ₄ is a group other than the hydrogen atom in the above definition; R and Z are each independently and represent a hydrogen atom or carbon The number is an alkyl group of 1 to 6; Y ₁ is a divalent organic group represented by the following formula (H);

In formula (H), R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl halide in which at least a part of hydrogen atoms on an alkyl group having 1 to 3 carbon atoms is substituted by a halogen atom group, at least one R is a halogen atom or the aforementioned halogenated alkyl group; * represents an atomic bond;

In formula (2), R ₁ to R ₄ , R, and Z are synonymous with the aforementioned formula (1); Y ₂ is a divalent organic group represented by the following formula (O);

In formula (O), Ar is independent of each other and represents a benzene ring, a biphenyl structure, or a naphthalene ring; any hydrogen atom on the benzene ring or naphthalene ring owned by Ar can also be substituted by a halogen atom or a monovalent organic group; Q ₂ represents -(CH ₂ ) _n - (n is an integer of 2 to 18), or a part of this -(CH ₂ ) _n - is -O-, -C(=O)- or -OC(=O)- Any group substituted; * indicates atomic bond. The liquid crystal alignment agent of claim 1, wherein the divalent organic group represented by the formula (H) is a divalent organic group represented by any one of the following formulas (h-1) to (h-9);

In the formulae (h-1) to (h-9), * represents an atomic bond. The liquid crystal aligning agent of claim 1, wherein the divalent organic group represented by the formula (O) is a divalent organic group represented by any one of the following formulae (o-1) to (o-14);

In formulas (o-1) to (o-14), * represents an atomic bond; in formula (o-14), two m's are each independent. The liquid crystal aligning agent of claim 1, wherein the polymer (A) is further selected from the group consisting of repeating units (a2') represented by the following formula (2') and repeating units represented by the following formula (3) (a3) a polyimide precursor constituting at least one of the group, and a polymer of at least one in the group consisting of polyimide that is an imide compound of the polyimide precursor;

In the formula (2') and the formula (3), X _2' and X ₃ represent a tetravalent organic group, Y _2' is a divalent organic group represented by the following formula (O 2 ), and Y ₃ represents a molecule having "-N(D)-(D represents a urethane-based protecting group)" group, and a divalent organic group having 6 to 30 carbon atoms other than D; R and Z are synonymous with the above formula (1)) ;

In formula (O2), Ar _2' is independent of each other and represents a benzene ring, and any hydrogen atom on the benzene ring can also be substituted by an alkyl group having 1 to 6 carbon atoms; Q _2' represents a single bond, or -O-; m represents an integer from 0 to 2; * represents an atomic bond. The liquid crystal aligning agent of claim 4, wherein the divalent organic group represented by the formula (O2) is a divalent organic group represented by any one of the following formulas (o2-1) to (o2-3);

In the formulae (o2-1) to (o2-3), * represents an atomic bond. The liquid crystal aligning agent of claim 1, wherein, in the polymer (A), the total content of the imidized structure of the repeating unit (a1) and the repeating unit (a1) is 5-95 mol of all repeating units %, and the total content of the repeating unit (a2) and the imidized structure of the repeating unit (a2) is 5-95 mol% of all repeating units. The liquid crystal aligning agent of claim 1, wherein, in the polymer (A), the total content of the repeating unit (a1), the repeating unit (a2) and the imidized structures is 90 mol% or more . The liquid crystal alignment agent of claim 1, which is used for the formation of a liquid crystal alignment film for a photo-alignment treatment method. A liquid crystal alignment film is obtained from the liquid crystal alignment agent according to any one of claims 1 to 8. A liquid crystal display element comprising the liquid crystal alignment film of claim 9. A method for manufacturing a liquid crystal alignment film, comprising the following steps (1) to (3); Step (1): apply the liquid crystal alignment agent according to any one of claims 1 to 8 on the substrate; Step (2): calcining the coated liquid crystal alignment agent; Step (3): performing alignment treatment on the film obtained in step (2). The method for producing a liquid crystal alignment film of claim 11, wherein the alignment treatment is a photo-alignment treatment. The method for producing a liquid crystal alignment film according to claim 12, wherein the irradiation amount of radiation in the photo-alignment treatment is 100-1500 mJ/cm ² . The method for manufacturing a liquid crystal alignment film of claim 11, further comprising the following step (4); Step (4): heat treatment at 50-300° C. for the film subjected to the alignment treatment in step (3). A liquid crystal display element comprising a liquid crystal alignment film obtained by the method for producing a liquid crystal alignment film according to any one of claims 11 to 14.

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