TW202146528A - Liquid crystal alignment agent for photo-alignment process, liquid crystal alignment film, and liquid crystal display component which may obtain high liquid crystal alignment by means of a photo-alignment process, and suppress a deviation of in-plane luminance during black display - Google Patents

Abstract

(式中，X₁ 表示以下述式(B)表示之4價有機基，X₂ 表示以下述式(C)表示之4價有機基。R、Z係分別獨立地表示氫原子或碳數1~6之烷基。複數個R及Z，各自可相同亦可相異。Y₁ 、Y₂ 係分別獨立地表示以下述式(O)表示之2價有機基)。

(式中，R_b1 ~R_b4 係分別獨立地表示氫原子、鹵素原子，或碳數1~6之烷基。L₁ 表示單鍵、-CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經 -O-、-C(=O)-或-O-C(=O)-之任一者取代之基。R_c1 ~R_c4 係分別獨立地表示氫原子、鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數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_c1 ~R_c4 之至少一者表示上述定義中的氫原子以外之基)。

(Ar表示苯環、聯苯結構，或萘環，2個Ar可相同亦可相異，環上的任意氫原子亦可經1價有機基取代。Q₂ 表示 -CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經-O-、-C(=O)-或-O-C(=O)-之任一者取代之基。p為0或1之整數。惟，p為0時，Ar表示聯苯結構，p為1時，2個Ar之至少一者表示萘環。*表示鍵結部位)。The subject of the present invention is to provide a liquid crystal aligning agent for photo-alignment that can obtain high liquid crystal alignment by photo-alignment, suppresses the variation in in-plane luminance during black display, and compares an improved liquid crystal display element. The solution is a liquid crystal alignment agent for a photo-alignment method, which contains at least one polymer (A) selected from the group consisting of polyimide precursors and imidized polymers thereof, the polymer (A) ) has at least one repeating unit (a1) selected from the group consisting of the repeating unit represented by the following formula (1-a) and the repeating unit represented by the following formula (1-i), and is selected from the following formula ( At least one repeating unit (a2) of the group consisting of the repeating unit represented by 2-a) and the repeating unit represented by the following formula (2-i), and containing 1 to 20 mol% of the aforementioned repeats of all repeating units unit (a1).

(wherein, X ₁ represents a tetravalent organic group represented by the following formula (B), and X ₂ represents a tetravalent organic group represented by the following formula (C). R and Z each independently represent a hydrogen atom or a carbon number of 1 An alkyl group of ~6. A plurality of R and Z may be the same or different from each other. Y _{1 and Y 2} each independently represent a divalent organic group represented by the following formula (O).

(In the formula, R _b1 to R _b4 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. L ₁ represents a single bond, -CH ₂ -, -(CH ₂ ) _n -(n is an integer from 2 to 18), or at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted by any one of -O-, -C(=O)- or -OC(=O)- R _c1 to R _c4 independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, and a fluorine atom-containing group. A monovalent organic group having 1 to 6 carbon atoms, or a phenyl group, _{and at least one of R c1} to R _c4 represents a group other than a hydrogen atom in the above definition).

(Ar represents a benzene ring, a biphenyl structure, or a naphthalene ring, the two Ars can be the same or different, and any hydrogen atom on the ring can also be substituted by a monovalent organic group. Q ₂ represents -CH ₂ -, -(CH ₂ ) _n - (n is an integer of 2 to 18), or _{at least a part of -CH 2 - of the aforementioned -(CH 2} ) _n - is processed by -O-, -C(=O)- or -OC(=O) A group substituted by any of -. p is an integer of 0 or 1. However, when p is 0, Ar represents a biphenyl structure, and when p is 1, at least one of the two Ars represents a naphthalene ring. * represents a bond part).

Description

Liquid crystal alignment agent for photo-alignment, liquid crystal alignment film, and liquid crystal display element

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

From the past, liquid crystal display devices have been widely used as display parts of personal computers, smart phones, mobile phones, television receivers, and the like. The liquid crystal display device includes, for example, 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 controlling the alignment of liquid crystal molecules in the liquid crystal layer, Thin-film transistors (TFTs), etc. that switch electrical signals supplied to pixel electrodes. As a driving method of liquid crystal molecules, a vertical electric field method such as a TN (Twisted Nematic) method and a VA (Vertical Alignment) method, and a transverse electric field method such as an IPS (In Plane Switching) method and a FFS (Fringe Field Switching) method are known. .

At present, the most popular liquid crystal alignment film in the industry is a surface of a film formed on the electrode substrate containing polyimide and/or polyimide obtained by imidizing it, with a , Nylon, polyester and other fabrics are rubbed in one direction so-called rubbing treatment. The rubbing treatment is an industrially useful method that is simple and excellent in productivity. However, with the increase in performance, high definition, and size of liquid crystal display elements, scratches on the surface of the alignment film caused by rubbing treatment, the generation of dust, the influence of mechanical force or static electricity, and the unevenness in the alignment treatment surface Issues such as sex become 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. As the photoalignment method, those utilizing a photoisomerization reaction, a photocrosslinking reaction, and a photolysis reaction have been proposed (see Non-Patent Document 1 and Patent Document 1).

A liquid crystal alignment film, which is a constituent member of a liquid crystal display element, is a film for aligning liquid crystals uniformly, and liquid crystal alignment is one of the important characteristics. However, compared with the liquid crystal alignment film obtained by the conventional rubbing treatment, the liquid crystal alignment film obtained by the aforementioned photo-alignment method tends to have a lower liquid crystal alignment, and the application scope of the liquid crystal display device provided with the liquid crystal alignment film is limited. . [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 9-297313 [Non-patent literature]

[Non-Patent Document 1] "Functional Materials", November 1997, Vol. 17, No. 11, pp. 13-22

[The problem to be solved by the invention]

Furthermore, in an actual liquid crystal display element, the twist angle of the liquid crystal slightly varies within the surface of the liquid crystal display element due to variations in manufacturing and the like. In this way, due to such an in-plane variation, in a liquid crystal display element, the luminance at the time of black display varies within the plane. The present invention has been made in view of the above-mentioned facts, and one of its objectives is to provide a liquid crystal display with high liquid crystal alignment that can be obtained by a photo-alignment method, suppressing in-plane luminance variation during black display, and having an improved contrast ratio Liquid crystal alignment agent for photo-alignment of components. [means to solve the problem]

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

A liquid crystal alignment agent for photo-alignment, characterized by containing at least one polymer (A) selected from the group consisting of polyimide precursors and imidized polymers thereof, the polymer (A) having At least one repeating unit (a1) selected from the group consisting of a repeating unit represented by the following formula (1-a) and a repeating unit represented by the following formula (1-i), and At least one repeating unit (a2) selected from the group consisting of the repeating unit represented by the following formula (2-a) and the repeating unit represented by the following formula (2-i), and contains 1 to 20 of all repeating units Molar % of the aforementioned repeating unit (a1).

(式中，X₁ 表示以下述式(B)表示之4價有機基，X₂ 表示以下述式(C)表示之4價有機基。R、Z係分別獨立地表示氫原子或碳數1~6之烷基。複數個R及Z，各自可相同亦可相異。Y₁ 、Y₂ 係分別獨立地表示以下述式(O)表示之2價有機基)。

(wherein, X ₁ represents a tetravalent organic group represented by the following formula (B), and X ₂ represents a tetravalent organic group represented by the following formula (C). R and Z each independently represent a hydrogen atom or a carbon number of 1 An alkyl group of ~6. A plurality of R and Z may be the same or different from each other. Y _{1 and Y 2} each independently represent a divalent organic group represented by the following formula (O).

(式中，R_b1 ~R_b4 係分別獨立地表示氫原子、鹵素原子，或碳數1~6之烷基。L₁ 表示單鍵、-CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經 -O-、-C(=O)-或-O-C(=O)-之任一者取代之基。R_c1 ~R_c4 係分別獨立地表示氫原子、鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數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_c1 ~R_c4 之至少一者表示上述定義中的氫原子以外之基)。

(In the formula, R _b1 to R _b4 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. L ₁ represents a single bond, -CH ₂ -, -(CH ₂ ) _n -(n is an integer from 2 to 18), or at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted by any one of -O-, -C(=O)- or -OC(=O)- R _c1 to R _c4 independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, and a fluorine atom-containing group. A monovalent organic group having 1 to 6 carbon atoms, or a phenyl group, _{and at least one of R c1} to R _c4 represents a group other than a hydrogen atom in the above definition).

(Ar表示苯環、聯苯結構，或萘環，2個Ar可相同亦可相異，環上的任意氫原子亦可經1價有機基取代。Q₂ 表示 -CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經-O-、-C(=O)-或-O-C(=O)-之任一者取代之基。p為0或1之整數。惟，p為0時，Ar表示聯苯結構，p為1時，2個Ar之至少一者表示萘環。*表示鍵結部位)。

(Ar represents a benzene ring, a biphenyl structure, or a naphthalene ring, the two Ars can be the same or different, and any hydrogen atom on the ring can also be substituted by a monovalent organic group. Q ₂ represents -CH ₂ -, -(CH ₂ ) _n - (n is an integer of 2 to 18), or _{at least a part of -CH 2 - of the aforementioned -(CH 2} ) _n - is processed by -O-, -C(=O)- or -OC(=O) A group substituted by any of -. p is an integer of 0 or 1. However, when p is 0, Ar represents a biphenyl structure, and when p is 1, at least one of the two Ars represents a naphthalene ring. * represents a bond part).

In addition, in this specification, * represents a bond site in any case. Boc represents tert-butoxycarbonyl. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the urethane-based protecting group include tert-butoxycarbonyl and 9-intenylmethoxycarbonyl. [Effect of invention]

The liquid crystal aligning agent for a photo-alignment method of the present invention comprises: having the repeating unit (a1) and the repeating unit (a2), and containing 1 to 20 mol% of the repeating unit (a1) of all repeating units. At least one polymer (A) selected from the group consisting of polyimide precursors and imidized polymers thereof, and suppresses variation in in-plane brightness when black display can be obtained by a photo-alignment method , to compare the effect of the improved liquid crystal display element.

The liquid crystal aligning agent for the photo-alignment method of the present invention (hereinafter also referred to only as a liquid crystal aligning agent) will be described.

<Polymer (A)> The liquid crystal aligning agent of the present invention contains at least one polymer (A) selected from the group consisting of polyimide precursors and imidized polymers thereof, and the polymer (A) has: At least one repeating unit (a1) of the group consisting of the repeating unit represented by the formula (1-a) and the repeating unit represented by the following formula (1-i), and selected from the group consisting of the repeating unit represented by the following formula (2-a) A repeating unit and at least one repeating unit (a2) of the group of repeating units represented by the following formula (2-i), and containing 1 to 20 mol% of the repeating unit (a1) in all repeating units. In addition, the polymer (A) may consist of one type or two or more types.

<Repeat unit (a1)> The repeating unit (a1) of the present invention is at least one repeating unit selected from the group consisting of the repeating unit represented by the following formula (1-a) and the repeating unit represented by the following formula (1-i).

(式中，X₁ 表示以下述式(B)表示之4價有機基。R、Z係分別獨立地表示氫原子或碳數1~6之烷基。2個R及Z，各自可相同亦可相異。Y₁ 表示以下述式(O)表示之2價有機基)。

(In the formula, X ₁ represents a tetravalent organic group represented by the following formula (B). R and Z each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Two R and Z may be the same as each other. may be different. Y ₁ represents a divalent organic group represented by the following formula (O).

(式中，R_b1 ~R_b4 係分別獨立地表示氫原子、鹵素原子，或碳數1~6之烷基。L₁ 表示單鍵、-CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經 -O-、-C(=O)-或-O-C(=O)-之任一者取代之基)。

(In the formula, R _b1 to R _b4 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. L ₁ represents a single bond, -CH ₂ -, -(CH ₂ ) _n -(n is an integer from 2 to 18), or at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted by any one of -O-, -C(=O)- or -OC(=O)- base).

(Ar表示苯環、聯苯結構，或萘環，2個Ar可相同亦可相異，環上的任意氫原子亦可經1價有機基取代。Q₂ 表示 -CH₂ -、-(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經-O-、-C(=O)-或-O-C(=O)-之任一者取代之基。p為0或1之整數。惟，p為0時，Ar表示聯苯結構，p為1時，2個Ar之至少一者表示萘環)。

(Ar represents a benzene ring, a biphenyl structure, or a naphthalene ring, the two Ars can be the same or different, and any hydrogen atom on the ring can also be substituted by a monovalent organic group. Q ₂ represents -CH ₂ -, -(CH ₂ ) _n - (n is an integer of 2 to 18), or _{at least a part of -CH 2 - of the aforementioned -(CH 2} ) _n - is processed by -O-, -C(=O)- or -OC(=O) A group substituted by any one of -. p is an integer of 0 or 1. However, when p is 0, Ar represents a biphenyl structure, and when p is 1, at least one of the two Ars represents a naphthalene ring).

A preferred example of the aforementioned L _{1 is a single bond, -CH 2} - or -(CH ₂ ) _n - (n is an integer of 2 to 18) from the viewpoint of efficiently obtaining the effects of the present invention. Preferred examples of the aforementioned R _b1 to R _b4 are hydrogen atoms from the viewpoint of efficiently obtaining the effects of the present invention.

The tetravalent organic group represented by the aforementioned formula (B) is preferably a tetravalent organic group represented by the following formulae (b-1) to (b-2) from the viewpoint of improving the alignment of liquid crystals.

Preferred examples of the divalent organic group represented by the aforementioned formula (O) are the divalent organic groups represented by the following formulae (o-1) to (o-7) from the viewpoint of efficiently obtaining the effects of the present invention.

<Repeat unit (a2)> The repeating unit (a2) of the present invention is at least one repeating unit selected from the group consisting of the repeating unit represented by the following formula (2-a) and the repeating unit represented by the following formula (2-i).

(式中，X₂ 表示以下述式(C)表示之4價有機基。R、Z係分別獨立地表示氫原子或碳數1~6之烷基。2個R及Z，各自可相同亦可相異。Y₂ 係與上述Y₁ 同義，包含較佳之具體例)。

(wherein, X ₂ represents a tetravalent organic group represented by the following formula (C). R and Z each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Two R and Z may be the same as each other. .Y ₂ may be different from the above-described system is synonymous with _an Y, comprising the specific preferred embodiment).

(式中，R_c1 ~R_c4 係分別獨立地表示氫原子、鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數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_c1 ~R_c4 之至少一者表示上述定義中的氫原子以外之基)。

(In the formula, R _c1 to R _c4 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and a fluorine atom-containing group. A monovalent organic group having 1 to 6 carbon atoms, or a phenyl group, _{and at least one of R c1} to R _c4 represents a group other than a hydrogen atom in the above definition).

As a tetravalent organic group represented by the said formula (C), the tetravalent organic group represented by following formula (Xc-1) - (Xc-6) is mentioned, for example. Among them, (Xc-1) is particularly preferable from the viewpoint of improving the alignment of the liquid crystal.

<Repeat unit (a3)> The aforementioned polymer (A) may be selected from the group consisting of repeating units (a1) and (a2) selected from the group consisting of repeating units represented by the following formula (3-a) and those represented by the following formula (3-i). At least one type of the group consisting of at least one repeating unit of the polyimide precursor of the repeating unit (a3) and at least one type of the group consisting of an imidized polymer thereof.

(式中，X₃ 表示4價有機基，Y₃ 表示以下述式(3d)表示之2價有機基。R、Z係與前述式(1-a)同義)。

(In the formula, X ₃ represents a tetravalent organic group, and Y ₃ represents a divalent organic group represented by the following formula (3d). R and Z are synonymous with the aforementioned formula (1-a).)

(Ar₃ 表示苯環或聯苯結構，2個Ar₃ 可相同亦可相異，上述環上之任意氫原子亦可經1價有機基取代。Q₃ 表示   -(CH₂ )_n -(n為2~18之整數)，或前述-(CH₂ )_n -之-CH₂ -的至少一部分經-O-、-C(=O)-或-O-C(=O)-之任一者取代之基)。

(Ar ₃ represents a benzene ring or a biphenyl structure, two Ar ₃ may be the same or different, and any hydrogen atom on the above-mentioned ring may also be substituted by a monovalent organic group. Q ₃ represents -(CH ₂ ) _n -(n is an integer from 2 to 18), or at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted by any one of -O-, -C(=O)- or -OC(=O)- base).

The divalent organic group represented by the aforementioned formula (3d) includes, for example, the divalent organic group represented by the following formulae (3d-1) to (3d-8), but is not limited thereto.

The polymer (A) may be selected from the group consisting of repeating units (a1) and (a2) other than repeating units (a1) and (a2), and may have repeating units selected from the following formula (4-a) and the following formula (4-i) At least one type of the group consisting of at least one repeating unit of the repeating unit (a4) and at least one type of the group consisting of the polyimide precursor and its imidized polymer.

(式中，R、Z係與前述式(1-a)同義。X₄ 表示4價有機基，Y₄ 表示分子內具有基「-N(D)-(D表示胺基甲酸酯系保護基)」之碳數6~30之2價有機基)。

(In the formula, R and Z are synonymous with the aforementioned formula (1-a). X ₄ represents a tetravalent organic group, Y ₄ represents a group having in the molecule "-N(D)-(D represents a urethane-based protection Divalent organic group with 6 to 30 carbon atoms).

A specific example of a divalent organic group having 6 to 30 carbon atoms having a group "-N(D)-(D represents a urethane-based protecting group)" in the molecule of Y _{4 includes the following formula (} A divalent organic group of a partial structure represented by 4-1), or a divalent organic group represented by the following formula (4-2).

In the formula, Q ₅ is a single bond, -(CH ₂ ) _n - (n is an integer from 1 to 20), or any -CH _{2 - of -(CH 2} ) _n - through -O-, -COO-, _{-OCO-, -NQ 9 -, - NQ} 9 -CO -, - CO-NQ 9 -, - NQ 9 -CO-NQ 10 -, - NQ 9 -COO- or -O-COO- group of substituents, Q ₉ and Q ₁₀ each independently represent a hydrogen atom or a monovalent organic group; Q ₆ and Q ₇ each independently represent -H, a group having -NHD, or a group having -N(D) ₂ . Q ₈ represents a group having -NHD, or a group having -N(D) ₂ . D represents a urethane-based protecting group. However, _{at least one of Q 5} , Q ₆ and Q ₇ has a urethane-based protecting group in the group. Specific examples of the monovalent organic group in Q ₉ and Q ₁₀ include alkyl groups with 1 to 6 carbon atoms, alkenyl groups with 2 to 6 carbon atoms, alkynyl groups with 2 to 6 carbon atoms, and carbon atoms with fluorine atoms. An alkyl group of 1 to 6, the aforementioned urethane-based protecting group, and an alkoxyalkyl group of 1 to 6 carbon atoms.

Here, Y _4, for example, ~ (Y4-4) of the above compound represented by formula (Y4-1) structure, but is not limited thereto.

The polymer (A) may be selected from the group consisting of repeating units (a1) and (a2), and may have repeating units selected from the following formula (5-a) and the following formula (5-i) At least one of the group consisting of at least one repeating unit of the repeating unit (a5) and the group consisting of the polyimide precursor and its imidized polymer.

式(5-a)及式(5-i)中，R、Z係與前述式(1-a)同義。X₅ 表示4價有機基，Y₅ 表示2價有機基。惟，Y₅ 表示前述式(3d)表示之2價有機基，或分子內具有基「-N(D)-(D表示胺基甲酸酯系保護基)」的碳數6~30之2價有機基以外之結構，X₅ 與前述式(B)表示之4價有機基或前述式(C)表示之4價有機基同義時，Y₅ 表示以前述式(O)表示之2價有機基以外之結構。

In formula (5-a) and formula (5-i), R and Z are synonymous with the aforementioned formula (1-a). X ₅ represents a tetravalent organic group, and Y ₅ represents a divalent organic group. However, Y ₅ represents a divalent organic group represented by the aforementioned formula (3d), or 2 of 6 to 30 carbon atoms having a group "-N(D)-(D represents a urethane-based protecting group)" in the molecule A structure other than a valent organic group, when X _{5 is} synonymous with a tetravalent organic group represented by the aforementioned formula (B) or a tetravalent organic group represented by the aforementioned formula (C), Y ₅ represents a bivalent organic group represented by the aforementioned formula (O) structure other than the base.

In formula (5-a) and formula (5-i), _{specific examples of Y 5} include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2, 5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl Benzene, 3,3'-difluoro-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'- Diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenyl Methane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl Phenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminobenzylaniline, 4,4'-diamine azobenzene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-Diaminonaphthalene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-amine 2 obtained by removing two amine groups from aromatic diamines such as 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, etc. As the valent organic group, the divalent organic group exemplified by Y ₆ described later can also be mentioned.

The structure of the tetravalent organic group of the aforementioned X ₃ , X ₄ and X ₅ is not particularly limited, and an arbitrary structure can be independently selected. Preferred specific examples include the following formulae (X1-1) to (X1-44).

式(X1-1)~(X1-4)中，R³ ~R²³ 係分別獨立地為氫原子、鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數2~6之炔基、含有氟原子之碳數1~6之1價有機基，或苯基。就液晶配向性之觀點，R³ ~R²³ 較佳為氫原子、鹵素原子、甲基，或乙基；更佳為氫原子，或甲基。

In formulas (X1-1) to (X1-4), R ³ to R ²³ are independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and a carbon number. An alkynyl group of 2 to 6, a monovalent organic group of 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. From the viewpoint of liquid crystal alignment, R ³ to R ^{23 are} preferably a hydrogen atom, a halogen atom, a methyl group, or an ethyl group; more preferably a hydrogen atom or a methyl group.

Specific examples of the formula (X1-1) include the following formulae (X1-1-1) to (X1-1-6). From the viewpoint of the liquid crystal alignment and the sensitivity of the photoreaction, (X1-1-1) to (X1-1-2) are more preferable, and (X1-1-2) is particularly preferable.

From the viewpoint of obtaining the effects of the present invention favorably, the polymer (A) preferably contains 1 to 20 mol % of the repeating unit (a1), more preferably 1 to 15 mol % of the total repeating unit.

From the viewpoint of obtaining the effect of the present invention favorably, the polymer (A), preferably the total of the repeating unit (a1) and the repeating unit (a2) is 5 mol% or more of all repeating units, more preferably 10 mol% above.

From the viewpoint of obtaining the effects of the present invention well, the polymer (A) preferably contains 1 to 95 mol% of the repeating units (a3) of all repeating units, more preferably 1 to 90 mol%, and more preferably Contains 5~90 mol%. In this case, the total of the repeating unit (a1) and the repeating unit (a2) is preferably 99 mol % or less, more preferably 95 mol % or less.

From the viewpoint of obtaining the effect of the present invention favorably, the polymer (A) preferably contains 1 to 40 mol% of the repeating unit (a4) of all repeating units, more preferably 1 to 30 mol%, and more preferably Contains 1~25 mol%.

<Polymer (B)> The liquid crystal aligning agent of this invention may contain the polymer (B) which has a repeating unit represented by following formula (6) from a viewpoint of reducing the residual image derived from residual DC. In addition, the polymer (B) does not have the above-mentioned repeating unit (a1) and repeating unit (a2) in the same molecule. In addition, the polymer (B) may be composed of one kind or two or more kinds, and the repeating unit constituting the polymer (B) may be composed of one kind or two or more kinds.

(X₆ 為4價有機基，Y₆ 為2價有機基。R、Z係與式(1-a)同義)。

(X ₆ is a tetravalent organic group, and Y ₆ is a divalent organic group. R and Z are synonymous with formula (1-a)).

In the foregoing formula X ₆₄ monovalent organic group, derived from a tetravalent organic group include dianhydrides of a non-cyclic aliphatic tetracarboxylic acid, derived from a tetravalent organic group of the alicyclic tetracarboxylic acid dianhydride, derived from an aromatic The tetravalent organic group of tetracarboxylic dianhydride, etc. Specific examples of the tetravalent organic group derived from acyclic aliphatic tetracarboxylic dianhydride and the tetravalent organic group derived from alicyclic tetracarboxylic dianhydride include the following formulas (x-1) to Structure selected in (x-13).

(上述式(x-1)~(x-13)中，R¹ ~R⁴ 係分別獨立地表示氫原子、鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數2~6之炔基、具有氟原子之碳數1~6之1價有機基或苯基。R⁵ 及R⁶ 係分別獨立地表示氫原子或甲基)。

(In the above formulae (x-1) to (x-13), R ¹ to R ⁴ independently 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, An alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having a fluorine atom having 1 to 6 carbon atoms, or a phenyl group. R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group).

Among them, the above formula (x-1) is preferably selected from the group formed by the following formulae (x1-1) to (x1-6).

上述式(x1-1)~(x1-6)中，*1表示鍵結於一方之酸酐基的鍵結部位，又，*2表示鍵結於另一方之酸酐基的鍵結部位。

In the above-mentioned formulae (x1-1) to (x1-6), *1 represents a bond site to one acid anhydride group, and *2 represents a bond site to the other acid anhydride group.

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. When a specific example is given, the tetravalent organic group represented by the said formula (X1-28) - (X1-40) is mentioned.

The divalent organic group in the aforementioned formula Y ₆ includes a nitrogen atom-containing heterocycle, a structure having at least one nitrogen-containing atom selected from the group consisting of a secondary amine group and a tertiary amine group (hereinafter also referred to as Nitrogen-containing structure) diamine, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4, 6-Diaminoresorcinol, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, the following formulas (3b-1) to formula Diamines having carboxyl groups such as diamine compounds represented by (3b-4), 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 4,4' -Diaminodiphenylmethane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzylaniline, 4, 4'-Diaminoazobenzene, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 1,3-bis(4-aminophenethyl)urea and other diamines having urea bonds, 2-(2,4-Diaminophenoxy)ethyl methacrylate, 2,4-diamino-N,N-diallylaniline, etc. Diamines having photopolymerizable groups at the terminals, choles Stalkoxy-3,5-diaminobenzene, Cholestyloxy-3,5-diaminobenzene, Cholestyloxy-2,4-diaminobenzene, 3,5-diamine Cholestyl benzoate, Cholestyl 3,5-diaminobenzoate, Lanostanyl 3,5-diaminobenzoate, 3,6-bis(4-aminobenzyl) Diamines having steroid skeletons such as acyloxy)cholestane, diamines represented by the following formulae (V-1) to (V-8), 1,3-bis(3-aminopropyl)-tetrakis Diamines with siloxane bonds such as methyldisiloxane, diamines with oxazoline structures such as the following formulas (Ox-1)~(Ox-2), etc. are removed 2 amine groups The obtained divalent organic group, a group represented by any one of the formulae (Y-1) to (Y-167) described in International Publication No. 2018/117239, and the like.

(式(3b-1)中，A¹ 表示單鍵、-CH₂ -、-C₂ H₄ -、-C(CH₃ )₂ -、-CF₂ -、-C(CF₃ )₂ -、-O-、-CO-、-NH-、-N(CH₃ )-、 -CONH-、-NHCO-、-CH₂ O-、-OCH₂ -、-COO-、-OCO-、 -CON(CH₃ )-或N(CH₃ )CO-，m1及m2係分別獨立地表示0~4之整數，且m1+m2表示1~4之整數。式(3b-2)中，m3及m4係分別獨立地表示1~5之整數。式(3b-3)中，A² 表示碳數1~5之直鏈或分支烷基，m5表示1~5之整數。式(3b-4)中，A³ 及A⁴ 係分別獨立地表示單鍵、-CH₂ -、-C₂ H₄ -、-C(CH₃ )₂ -、-CF₂ -、-C(CF₃ )₂ -、-O-、-CO-、-NH-、-N(CH₃ )-、 -CONH-、-NHCO-、-CH₂ O-、-OCH₂ -、-COO-、-OCO-、  -CON(CH₃ )-或-N(CH₃ )CO-，m6表示1~4之整數)。

(In formula (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 -, - OCH 2 -, - COO -, - OCO-, -CON ( CH ₃ )- or N(CH ₃ )CO-, m1 and m2 each independently represent an integer from 0 to 4, and m1+m2 represent an integer from 1 to 4. In formula (3b-2), m3 and m4 are Each independently represents an integer of 1 to 5. In formula (3b-3), A ² represents 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 each independently represent 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-, -OCH ₂ -, -COO-, -OCO-, -CON(CH ₃ )- or -N(CH ₃ )CO-, m6 represents an integer from 1 to 4).

(X^v1 ~X^v4 、X^p1 ~X^p2 係分別獨立地表示-(CH₂ )_a -(a為1~15之整數)、-CONH-、-NHCO-、-CON(CH₃ )-、-NH-、 -O-、-CH₂ O-、-CH₂ OCO-、-COO-，或-OCO-，X^v5 表示  -O-、-CH₂ O-、-CH₂ OCO-、-COO-，或-OCO-。X_a 表示單鍵、-O-、-NH-、-O-(CH₂ )_m -O-(m表示1~6之整數)，R^v1 ~R^v4 、R^1a ~R^1b 係分別獨立地表示碳數1~20之烷基、碳數1~20之烷氧基或碳數2~20之烷氧基烷基。X^V7 ~X^V8 係分別獨立地表示-O-、-CH₂ O-、-COO-或-OCO-)。

(X ^v1 to X ^v4 and X ^p1 to X ^p2 independently represent -(CH ₂ ) _a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-, X ^v5 means -O-, -CH ₂ O-, -CH ₂ OCO-, -COO -, or -OCO-. X _a represents a single bond, -O-, -NH-, -O-(CH ₂ ) _m -O- (m represents an integer from 1 to 6), R ^v1 ~R ^v4 , R ^1a ~R ^1b represent independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having a carbon number of 1 to 20, or an alkoxyalkyl group having a carbon number of 2 to 20. X ^V7 to X ^V8 each independently represent - _{O -, - CH 2 O -} , - COO- or -OCO-).

啶、喹噁啉、酞嗪、三嗪、咔唑、吖啶、哌啶、哌嗪、吡咯啶、六亞甲亞胺等。其中尤以吡啶、嘧啶、吡嗪、哌啶、哌嗪、喹啉、咔唑或吖啶為佳。Examples of the nitrogen-containing heterocyclic ring include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyrazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline,

pyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, hexamethyleneimine, etc. Among them, pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole or acridine are particularly preferred.

The secondary amine group and the tertiary amine group which the diamine having a nitrogen atom-containing structure may have are represented by, for example, the following formula (n).

上述式(n)中，R表示氫原子或碳數1~10之1價烴基。「*1」表示鍵結於烴基之鍵結部位。

In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*1" represents the bonding site to which the hydrocarbon group is bonded.

Examples of the monovalent hydrocarbon group of the above formula R include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; and aryl groups such as phenyl and methylphenyl. R is preferably a hydrogen atom or a methyl group.

Specific examples of the diamine having a nitrogen atom-containing structure include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, and 3,6-diaminopyridine Carbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)piperazine, 3,6-diaminoacridine, N-ethyl- 3,6-Diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)benzidine, N,N'-bis(4 -aminophenyl)-N,N'-dimethylbenzidine, 4,4'-diaminodiphenylamine, N,N-bis(4-aminophenyl)-methylamine, the following formula ( z-1) to compounds represented by formula (z-23).

The polymer (B) is preferably a polymer comprising a repeating unit from the viewpoint of less residual image due to residual DC, and in the repeating unit, Y ₆ is selected from the group consisting of diamines having a nitrogen atom-containing structure, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, The above-mentioned diamine having a carboxyl group or the above-mentioned diamine having a urea bond is a group of divalent organic groups obtained by removing two amine groups (these are also collectively referred to as specific divalent organic groups).

The polymer (B) may contain 1 mol % or more of the total repeating units contained in the polymer (B) from the viewpoint of less residual image due to residual DC. Y ₆ is the above-mentioned specific divalent organic group. Repeating units may also contain more than 5 mol%.

From the viewpoint of less afterimages due to residual DC, the content ratio of the polymer (A) and the polymer (B) in terms of the mass ratio of [polymer (A)]/[polymer (B)] may be 10/90~90/10, can be 20/80~90/10, can also be 20/80~80/20.

<The manufacturing method of polyamide acid, polyamide ester and polyimide> The polyimide precursor used in the present invention, the polyamide ester, the polyamide acid, and the polyimide, can be synthesized, for example, by a known method as described in International Publication No. 2013/157586. Specifically, it is synthesized by subjecting a diamine component and a tetracarboxylic acid derivative component to (polycondensation) reaction in a solvent. As said tetracarboxylic-acid derivative component, tetracarboxylic dianhydride or its derivative(s) (tetracarboxylic-acid dihalide, tetracarboxylic-acid diester, or tetracarboxylic-acid diester dihalide) is mentioned. When a part of the polymer (A) or (B) contains an aramidic acid structure, for example, by reacting a tetracarboxylic dianhydride component with a diamine component, a polymer having an aramidic acid structure (polyacidic acid) can be obtained. ). The solvent is not particularly limited as long as it dissolves the produced polymer.

The diamine component and the tetracarboxylic acid derivative component used to obtain the polyimide precursor of the polymer (A) are based on the above-mentioned formula (1-a) and formula (2-) of the polymer (A), respectively. a), and the repeating units represented by formula (3-a), formula (4-a), and formula (5-a) according to need, are selected and used in a way to obtain the structure of the repeating unit. For example, a polymer (A) has the formula (1-a) represents a repeating unit of the diamine component, based having _{-N (Z) -Y 1 -N (} Z) - The structure of (Y _1, The definition of Z is the same as the above-mentioned diamine, and as the tetracarboxylic acid derivative component, a tetracarboxylic acid derivative having a structure of the following formula is used.

(X₁ 之定義係與上述相同)。

( _{The definition of X 1} is the same as above).

The polyamic acid ester can be, for example, [I] a method of reacting the polyamic acid obtained by the above 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.

The method for obtaining polyimide includes thermal imidization by directly heating a solution containing a polyimide precursor such as polyimide and polyimide obtained by the above-mentioned reaction, or adding to the above-mentioned solution. Catalyst catalyzed imidization. In the polyimide used in the present invention, the ring closure ratio of the amide acid group (also referred to as the amide imidization ratio) does not necessarily have to be 100%, and can be adjusted arbitrarily according to the application or purpose. For example, the imidization rate of the polyimide can be 20-100%, 50-99%, or 70-99% from the viewpoint of improving the solubility of the polyimide coating.

<Solution viscosity/molecular weight of polymer> When the polyamic acid, polyamic acid ester and polyimide used in the present invention are a solution having a concentration of 10 to 15 mass %, it is preferable to have, for example, 10 to 1000 mPa･s from the viewpoint of workability. The viscosity of the solution is not particularly limited. In addition, the solution viscosity (mPa･s) of the above-mentioned polymer is a concentration of 10~ 15 mass % polymer solution, the value measured at 25 degreeC using the E-type rotational viscometer.

The weight-average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the above-mentioned polyamic acid, polyamic acid ester and polyimide is preferably 1,000 to 500,000, or more Preferably 2,000~300,000. Moreover, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene conversion number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, favorable alignment and stability of the liquid crystal display element can be ensured.

<Liquid crystal alignment agent> The liquid crystal aligning agent of the present invention contains a polymer (A) and a polymer (B) as required. In addition to the polymer (A) and the polymer (B), the liquid crystal aligning agent of the present invention may contain other polymers. Other types of polymers include polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene or its derivatives, poly(styrene-phenylmaleic acid) imide) derivatives, poly(meth)acrylates, etc.

The liquid crystal aligning agent is used in the production of a liquid crystal aligning film, and takes the form of a coating solution from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the aforementioned polymer component and an organic solvent. At this time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, it is preferably 1 mass % or more, and from the viewpoint of the storage stability of the solution, it 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 it dissolves the polymer component uniformly. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-Ethyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)- 2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N- Cyclohexyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone , cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide (these are also collectively referred to as "good solvents"), etc. . Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide or γ-butyrolactone is preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the entire solvent contained in the liquid crystal aligning agent.

In addition, the organic solvent contained in the liquid crystal aligning agent is preferably a solvent (also referred to as a poor solvent) that is used in combination with the above-mentioned solvents to improve the coatability or the surface smoothness of the coating film when coating the liquid crystal aligning agent. the mixed solvent. Specific examples of the organic solvent used in combination are as follows, but are not limited thereto.

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-pentane Ketone, Diethylene Glycol Methyl Ether, Diethylene Glycol Dibutyl Ether, 3-Ethoxybutyl Acetate, 1-Methyl Amyl Acetate, 2-Ethyl Butyl Acetate, 2-Ethyl Acetate Ethyl hexyl ester, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol mono Hexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether Acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol Glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl acetate base ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3-methoxypropionic acid Butyl ester, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

Among them, diisobutylmethanol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4 - methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone.

A preferable combination of a good solvent and a poor solvent can include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone With ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N -Methyl-2-pyrrolidone with γ-butyrolactone with 4-hydroxy-4-methyl-2-pentanone with diethylene glycol diethyl ether, N-methyl-2-pyrrolidone with γ-Butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diiso Propyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and propylene glycol monobutyl ether with 2,6-dimethyl-4-heptanol, 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, etc. The content of the poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass of the entire solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected according to the coating apparatus, coating conditions, coating environment and the like of the liquid crystal alignment agent.

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). Such additive components include adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate or adhesion between the liquid crystal alignment film and the sealant, and compounds for improving the strength of the liquid crystal alignment film (hereinafter also referred to as It is a cross-linking compound), a compound for promoting imidization, a dielectric or conductive substance for adjusting the permittivity or resistance of the liquid crystal alignment film, and the like.

The above-mentioned crosslinkable compound may have a compound selected from the group consisting of ethylene oxide group, oxetanyl group, protected isocyanate group, protection Isothiocyanate group, group containing oxazoline ring structure, group containing Meldrum's acid structure, cyclic carbonate group, and at least one group of the group of groups represented by formula (d) The compound, or a compound selected from the compounds represented by the following formula (e) (hereinafter, these are also collectively referred to as compound (C)).

(R₂ 及R₃ 係分別獨立地為氫原子、碳數1~3之烷基或「*-CH₂ -OH」。A表示具有芳香環之(m+n)價有機基。m表示1~6之整數，n表示0~4之整數。R表示氫原子或碳數1~5之烷基。上述A之芳香環上的氫原子，亦可經鹵素原子、碳數1~6之烷基、碳數2~6之烯基、碳數2~6之炔基、含有氟原子之碳數1~6之1價有機基等之1價有機基取代)。

(R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or "*-CH ₂ -OH". A represents an (m+n)-valent organic group having an aromatic ring. m represents 1 An integer of ~6, n represents an integer of 0 to 4. R represents a hydrogen atom or an alkyl group with 1 to 5 carbon atoms. The hydrogen atom on the aromatic ring of the above A can also be passed through a halogen atom or an alkane with 1 to 6 carbon atoms. substituted by monovalent organic groups such as alkenyl groups with 2 to 6 carbon atoms, alkynyl groups with 2 to 6 carbon atoms, and monovalent organic groups with 1 to 6 carbon atoms containing fluorine atoms).

Specific examples of the compound having an oxirane group include the compound described in paragraph [0037] of JP-A No. 10-338880, the compound having a triazine ring in the skeleton described in International Publication No. 2017/170483, and the like. A compound having two or more oxirane groups. Among these, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl) ) cyclohexane, N,N,N',N'-tetraglycidyl-4, 4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl- Nitrogen-containing compounds such as p-phenylenediamine and compounds represented by the following formulae (r-1) to (r-3).

Specific examples of the compound having an oxetanyl group include compounds having two or more oxetanyl groups described in paragraphs [0170] to [0175] of International Publication No. WO 2011/132751.

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 JP-A No. 2014-224978, and those described in International Publication No. 2015/141598. The compound etc. which have three or more protected isocyanate groups described in paragraphs [0119] to [0120] may also be compounds represented by the following formulae (bi-1) to (bi-3).

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 described in International Publication No. 2012/091088 can be mentioned.

Specific examples of the compound having a cyclocarbonate group include the compound described in International Publication No. 2011/155577.

_{The alkyl group having 1 to 3 carbon atoms in R 2} and R ₃ of the group represented by the aforementioned formula (d) includes a methyl group, an ethyl group, a propyl group, and the like.

Specific examples of the compound having a group represented by the aforementioned formula (d) include two or more of the aforementioned formula (d) described in paragraph [0058] of International Publication No. WO 2015/072554 or JP-A No. 2016-118753 The compound represented by the group, the compound described in JP 2016-200798 A, and the like may also be compounds represented by the following formulae (hd-1) to (hd-8).

The (m+n)-valent organic group having an aromatic ring in A of the aforementioned formula (e) includes an (m+n)-valent aromatic hydrocarbon group having 6 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms. (m+n)-valent organic group directly or via a linking group, and (m+n)-valent group having an aromatic heterocycle. As said aromatic hydrocarbon, benzene, naphthalene, etc. are mentioned, for example. Aromatic heterocycles include, for example, pyrrole rings, imidazole rings, pyrazole rings, pyridine rings, pyrimidine rings, quinoline rings, isoquinoline rings, carbazole rings, pyrazine rings, pyrazine rings, benzimidazole rings, Indole ring, quinoxaline ring, acridine ring, etc. The aforementioned linking group includes an alkylene group having 1 to 10 carbon atoms, -NR- (R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), a group obtained by removing one hydrogen atom from the aforementioned alkylene group, and 2 Valence or trivalent cyclohexane ring, etc. Furthermore, any hydrogen atom of the aforementioned alkylene group may be substituted with an organic group such as a fluorine atom or a trifluoromethyl group. Specific examples of the compound represented by the aforementioned formula (e) include the compound described in International Publication No. 2010/074269 and the compounds represented by the following formulae (e-1) to (e-10).

The above-mentioned compound is an example of a crosslinkable compound, and is not limited to these. For example, components other than the above-mentioned components disclosed in WO 2015/060357 No. 53 [0105] to 55 [0116] 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, and the crosslinking reaction is carried out, and the From the viewpoint of showing good resistance to AC afterimages, it is more preferably 1 to 15 parts by mass.

Examples of the aforementioned adhesion aid include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltriethoxysilane, and 2-aminopropyltriethoxysilane. Propyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl) )-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyl Triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl Silyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl Trimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane Ethoxysilane, N-bis(oxyethylidene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylidene)-3-aminopropyltriethoxysilane, vinyl Trimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styrene trimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyl Diethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, para-(trimethoxysilylpropyl)heterotrimer Silane coupling agent of cyanate ester, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc. When a silane coupling agent is used, from the viewpoint of exhibiting good resistance to AC afterimages, it is preferably 0.1-30 parts by mass, more preferably 0.1-30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent 20 parts by mass.

The compound for promoting the above imidization preferably has a basic moiety (eg, a primary amino group, an aliphatic heterocycle (eg, a pyrrolidine skeleton), an aromatic heterocycle (eg, an imidazole ring, an indole ring) ), or guanidino, etc.) compounds (except for the above-mentioned cross-linking compounds and adhesion assistants), or compounds that generate the above-mentioned basic sites during firing. More preferably, it is a compound which generates the above-mentioned basic moiety during calcination, and a preferable specific example is an amino acid in which a part or all of the basic moiety possessed by the amino acid is protected. Specific examples of the above amino acids include glycine, alanine, cysteine, methionine, aspartamine, glutamine, valine, leucine, phenylalanine, tyrosine Amino acid, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, ornithine. More preferable specific examples of the compound for promoting imidization include N-α-(9-intenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L- histidine.

<Manufacturing method of liquid crystal alignment film> The method for producing a liquid crystal alignment film using the liquid crystal alignment agent of the present invention is characterized by sequentially performing: the step of coating the liquid crystal alignment agent (step (1)), and the step of firing the applied liquid crystal alignment agent (step (1)) (2)), the step of irradiating the film obtained in step (2) with polarized ultraviolet rays (step (3)), and the film obtained in step (3) at a temperature above 100°C and higher than the temperature in step (2) The step of firing (step (4)).

<Step (1)> The substrate on which the liquid crystal aligning agent used in the present invention is applied is not particularly limited as long as it is a substrate with high transparency, and plastic substrates such as glass substrates, silicon nitride substrates, acrylic substrates, and polycarbonate substrates can also be used. . In this case, it is preferable from the viewpoint of process simplification to use a substrate on which ITO electrodes or the like for driving the liquid crystal are formed. In addition, in the reflective liquid crystal display element, as long as the substrate is only on one side, an opaque material such as a silicon wafer can also be used, and a material that reflects light such as aluminum can also be used as the electrode at this time.

The coating method of the liquid crystal alignment agent is not particularly limited, and generally in the industry, it is a method performed by screen printing, offset printing, flexographic printing, or inkjet method. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method, a spray method, and the like, and these can be used according to the purpose.

<Step (2)> Step (2) is a step of firing the liquid crystal aligning agent applied 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, or the amide acid or amide acid in the polymer can be evaporated. Thermal imidization of esters. The drying and firing 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. The firing temperature can be performed at, for example, 40 to 150°C. From the viewpoint of shortening the process, it can also be performed at 40 to 120°C. The calcination time is not particularly limited, and 1 to 10 minutes or 1 to 5 minutes can be mentioned. When thermal imidization of the amide acid or amide ester in the polymer is performed, after the above-mentioned calcination step, a calcination step in a temperature range of, for example, 190 to 250°C or 200 to 240°C can be performed. The calcination time is not particularly limited, and a calcination time of 5 to 40 minutes or 5 to 30 minutes is exemplified.

<Step (3)> The step (3) is a step of irradiating the film obtained in the step (2) with polarized ultraviolet rays. The wavelength of the ultraviolet rays is preferably 200 to 400 nm, and especially, the ultraviolet rays having a wavelength of 200 to 300 nm are more preferable. In order to improve the alignment of the liquid crystal, the substrate coated with the liquid crystal alignment film can also be heated at 50-250° C. and irradiated with ultraviolet rays at the same time. In addition, the irradiation amount of the ultraviolet rays is preferably 1 to 10,000 mJ/cm ² , more preferably 100 to 5,000 mJ/cm ² . The liquid crystal alignment film produced in this way can stably align liquid crystal molecules in a certain direction.

The higher the extinction ratio of polarized ultraviolet rays, the higher the anisotropy can be imparted, so it is better. Specifically, the extinction ratio of linearly polarized ultraviolet rays is preferably 10:1 or more, more preferably 20:1 or more.

<Step (4)> The step (4) is a step of firing the film obtained in the step (3) at a temperature above 100° C. and higher than the temperature in the step (2). The firing temperature is not particularly limited as long as it is 100°C or higher and higher than the firing temperature in step (2), preferably 150 to 300°C, more preferably 150 to 250°C, and still more preferably 200 to 250°C . The firing time is preferably 5 to 120 minutes, more preferably 5 to 60 minutes, and still more preferably 5 to 30 minutes.

When the thickness of the liquid crystal alignment film after firing is too thin, the reliability of the liquid crystal display element may decrease, so it is preferably 5 to 300 nm, more preferably 10 to 200 nm.

Further, after performing any one of the aforementioned steps (3) or (4), the obtained liquid crystal alignment film can also be subjected to a contact treatment with water or a solvent.

The solvent used for the above-mentioned contact treatment is not particularly limited as long as it dissolves the decomposed product generated by the liquid crystal alignment film by ultraviolet irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl Celosul, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate or cyclohexyl acetate, etc. Among them, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are particularly preferred from the viewpoint of versatility or safety of the solvent. More preferred is water, 1-methoxy-2-propanol or ethyl lactate. One type of solvent may be used, or two or more types may be combined.

The above-mentioned contact treatment, that is, the treatment of the liquid crystal alignment film irradiated with polarized ultraviolet rays with water or solvent, includes immersion treatment or spray treatment (also called spray treatment). The treatment time of these treatments is preferably 10 seconds to 1 hour from the viewpoint of efficiently dissolving the decomposed products generated from the liquid crystal alignment film by ultraviolet rays. Among them, immersion treatment for 1 to 30 minutes is particularly preferred. In addition, the solvent in the aforementioned contact treatment may be at room temperature or heated, preferably 10 to 80°C, more preferably 20 to 50°C. In addition, from the viewpoint of the solubility of the decomposition product, ultrasonic treatment and the like may be performed as necessary.

After the aforementioned contact treatment, it is preferable to perform cleaning (also called rinsing) or firing of the liquid crystal alignment film with a low-boiling solvent such as water, methanol, ethanol, 2-propanol, acetone, or methyl ethyl ketone. At this time, either one of rinsing and firing may be performed, or both may be performed. The firing temperature is preferably 150 to 300°C. Among them, 180-250 degreeC is especially preferable. More preferably, it is 200-230 degreeC. In addition, the time for firing is preferably 10 seconds to 30 minutes. Among them, 1 to 10 minutes is the best.

The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film for a liquid crystal display element of a transverse electric field method such as an IPS method or an FFS method, and is particularly useful as a liquid crystal alignment film for a liquid crystal display element of the FFS method. The liquid crystal display element is obtained by producing a liquid crystal cell by a known method after obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention, and using the liquid crystal cell.

As an example of the manufacturing method of a liquid crystal cell, the liquid crystal display element of a passive matrix structure is demonstrated as an example. Furthermore, it can also be a liquid crystal display element of an active matrix structure in which switching elements such as TFT (Thin Film Transistor) are provided in each pixel portion constituting the image display.

Specifically, a transparent glass substrate is prepared, a common electrode is provided on one substrate, and segment electrodes are provided on the other substrate. These electrodes can be, for example, ITO electrodes, which are patterned so that the desired image display can be performed. Next, an insulating film is provided on each substrate to cover the common electrode and the segment electrode. The insulating film may be, for example, a film of SiO ₂ -TiO ₂ formed by a sol-gel method.

Next, a liquid crystal alignment film is formed on each of the substrates, and on one of the substrates, the other substrates are stacked so that the surfaces of the liquid crystal alignment films face each other, and the periphery is bonded with a sealant. In order to control the gap between the substrates, a spacer is usually mixed in the sealant in advance, and it is preferable that a spacer for controlling the gap between the substrates is also dispersed in advance in the in-plane portion where the sealant is not provided. In a part of the sealant, an opening part which can be filled with liquid crystal from the outside is provided in advance. Next, the liquid crystal material was injected into the space surrounded by the two substrates and the sealant through the opening provided in the sealant, and then the opening was sealed with the adhesive. For the injection, a vacuum injection method or a method utilizing capillary phenomenon in the atmosphere may be used. As the liquid crystal material, any one of a positive type liquid crystal material or a negative type liquid crystal material can be used. Next, set the polarizer. Specifically, a pair of polarizers are attached to the surface of the two substrates on the opposite side to the liquid crystal layer.

By using the manufacturing method of the present invention, afterimages caused by long-term AC driving, which are generated in a liquid crystal display element of an IPS driving method or an FFS driving method, can be suppressed. Moreover, in step (2), after baking in the temperature range of 40-150 degreeC, by implementing step (3), a liquid crystal aligning film can be obtained with a smaller number of steps than in the past. The liquid crystal alignment agent of the present invention can be particularly preferably used in the manufacturing method of the liquid crystal alignment film including the step of implementing the step (3) after firing in the temperature range of 40-150°C in the step (2). [Example]

(solvent) NMP: N-methyl-2-pyrrolidone BCS: Butyl Cyrus (diamine) DA-1 to DA-9: compounds represented by the following formulae (DA-1) to (DA-9), respectively (tetracarboxylic dianhydride) CA-1 to CA-5: compounds represented by the following formulae (CA-1) to (CA-5), respectively (additive) C-1: 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane (compound represented by the following formula (C-1)) S-1: a compound represented by the following formula (S-1) F-1: a compound represented by the following formula (F-1)

(Fmoc表示9-茀基甲氧基羰基)。

(Fmoc represents 9-fenylmethoxycarbonyl).

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

<Measurement of imidization rate> 20 mg of polyimide powder was placed in an NMR sample tube (NMR sample tube standard, φ5 (manufactured by Kusano Scientific Co., Ltd.)), and deuterated dimethylsulfite (DMSO-d6, 0.05% TMS (tetramethylsilane) was added. ) mixture) (0.53 mL), and ultrasonically applied to dissolve it completely. The solution was measured for proton NMR at 500 MHz with an NMR measuring machine (JNW-ECA500) (manufactured by JEOL Ltd.). The imidization rate is determined by determining the proton originating from the unchanged structure before and after imidization as the reference proton, and using the peak integration value of the proton, and the difference between the proton derived from amide acid appearing in the vicinity of 9.5ppm to 10.0ppm. The integral value of the proton peak of the NH group is obtained by the following formula. Imidization rate (%)=(1-α･x/y)×100 In the above formula, when x is the peak integration value of the proton derived from the NH group of the amide acid, y is the peak integration value of the reference proton, and α is the polyamide acid (the imidization rate is 0%), the relative For one NH proton of amide acid, the ratio of the number of reference protons.

[Synthesis example of polymer] <Synthesis example 1> In a 200mL four-necked flask with a stirring device and a nitrogen introduction tube, measure DA-1 4.95g (20.3mmol), DA-2 5.30g (18.0mmol), and DA-3 1.60g (6.75mmol), add NMP was set to a concentration of 12 mass %, and was dissolved with stirring while feeding nitrogen. While stirring the diamine solution, 9.28 g (41.4 mmol) of CA-1 was added, and NMP was added to make the concentration 12% by mass, and the mixture was stirred at 40° C. for 24 hours to obtain a polyamic acid solution. 35 g (8.9 mmol) of the obtained polyamic acid solution was taken into a 100 mL four-neck flask with a stirring device and a nitrogen introduction tube, 11.7 g of NMP was added, and the mixture was stirred for 30 minutes. To the obtained polyamic acid solution, 2.74 g of acetic anhydride (3 equivalents compared to the polyamic acid molar) and 0.71 g of pyridine (equivalent to the polyamic acid moles) were added, and heated at 50°C for 3 hours , for chemical imidization. The obtained reaction solution was poured into 150 mL of methanol under stirring, the precipitated precipitate was collected by filtration, the same operation was performed twice to wash the resin powder, and then dried at 60° C. for 12 hours to obtain a polyimide resin powder. The imidization rate of the polyimide resin powder was 75%. 3.60 g of the obtained polyimide resin powder was taken into a 100-mL conical flask, NMP was added to make the solid content concentration 12%, and the solution was stirred at 70° C. for 24 hours to dissolve it to obtain a polyimide solution (PI-1 ).

<Synthesis Examples 2 to 10> Polyimide solutions (PI-2) to (PI-10) were obtained in the same manner as in Synthesis Example 1, except that the types and amounts of the monomers used were changed as described in Table 1 below. In addition, the numerical values in parentheses in Table 1, in terms of tetracarboxylic acid components, represent the blending ratio (mol Ear part), with respect to a diamine component, shows the compounding ratio (mol part) of each compound with respect to 100 mol parts of the total amount of diamines used for synthesis. The organic solvent refers to the blending ratio (parts by mass) of each organic solvent with respect to 100 parts by mass of the total amount of organic solvents used for the preparation of the polyimide solution. <Synthesis Example 11> In a 200mL four-necked flask with a stirring device and a nitrogen introduction tube, measure 3.37g (8.0mmol) of DA-7, 2.39g (8.0mmol) of DA-8, and 4.78g (24.0mmol) of DA-9, add NMP was set to a concentration of 12 mass %, and was dissolved with stirring while feeding nitrogen. While stirring the diamine solution, 11.3 g (38.5 mmol) of CA-5 was added, and NMP was added to make the concentration 12% by mass, and the mixture was stirred at 70° C. for 24 hours to obtain a polyamic acid solution (PAA-1).

[Preparation of liquid crystal alignment agent] <Comparative Example 1> In a sample tube with a stirring bar, add the solution of the polyimide solution (PI-1) obtained in Synthesis Example 1, NMP, and BCS, and add S-1, C-1, and F-1, so that 1 mass part, 10 mass parts, and 15 mass parts with respect to 100 mass parts of polymer solid content, respectively, and it stirred for 30 minutes. After stirring, the solid content concentration of the polyimide solution (PI-1) was 6 mass %, and the solvent composition was a liquid crystal aligning agent (R1) of NMP:BCS=80:20 by mass ratio.

<Comparative Examples 2 to 5, Examples 1 to 12> Liquid crystal aligning agents (R2) to (R5) and (1) to (12) were obtained in the same manner as in Comparative Example 1, except that the polymer components used were changed as described in Table 2 below. In Table 2, the values in parentheses represent the blending ratio of each polymer component or additive with respect to the total 100 parts by mass of the polymer component used for the preparation of the liquid crystal aligning agent with respect to the polymer and the additive, respectively. (parts by mass). The organic solvent refers to the blending ratio (parts by mass) of each organic solvent with respect to 100 parts by mass of the total amount of organic solvents in the liquid crystal aligning agent.

Using the liquid crystal aligning agent obtained as described above, an FFS-driven liquid crystal cell was produced by the procedure shown below, and characteristics were evaluated.

[The composition of the FFS-driven liquid crystal cell] The liquid crystal cell for fringe field switching (FFS) mode is formed on the surface with a FOP (Finger on Plate) electrode layer composed of a surface-shaped common electrode-insulating layer-comb-shaped pixel electrode The first glass substrate is a set of a second glass substrate having a columnar spacer having a height of 3.5 μm on the surface and an ITO film for antistatic formed on the rear surface. The above-mentioned pixel electrode has a comb-tooth shape in which electrode elements with a width of 3 μm bent at an inner angle of 160° in the central part are arranged in parallel with an interval of 6 μm in a comb-tooth shape, and one pixel is connected to a plurality of electrodes. The line of the curved part of an element is a boundary, and has a 1st area|region and a 2nd area|region. Furthermore, the liquid crystal alignment film formed on the first glass substrate is subjected to an alignment treatment in a manner that the direction that equally divides the inner angle of the curved portion of the pixel is perpendicular to the alignment direction of the liquid crystal, and the liquid crystal alignment film formed on the second glass substrate, The alignment treatment is performed so that the alignment direction of the liquid crystal on the first substrate and the alignment direction of the liquid crystal on the second substrate are consistent with each other when the liquid crystal cell is produced.

[Production of Liquid Crystal Cells] The liquid crystal aligning agent filtered through a filter with a pore size of 1.0 μm was applied on the surface of each of the above-mentioned glass substrates by spin coating, and dried on a hot plate at 80° C. for 2 minutes. ^{After that, irradiate 150~350 mJ/cm 2 of} linearly polarized ultraviolet rays with a wavelength of 254 nm with an extinction ratio of 26:1 to the surface of the coating film through a polarizing plate, and then bake in a hot air circulating oven at 230°C for 30 minutes to obtain 2 substrates with liquid crystal alignment film with a thickness of 100nm. Next, a sealant (XN-1500T manufactured by Mitsui Chemicals Co., Ltd.) was printed on one side of the above-mentioned substrates with liquid crystal alignment films, and the other substrates were bonded so that the surfaces of the liquid crystal alignment films faced each other. Empty unit cells are made by hardening. Liquid crystal (MLC-3019 manufactured by Merck & Co., Ltd.) was vacuum-injected into this empty cell at normal temperature 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 120 degreeC for 1 hour (this process is also called ISO process hereafter), and it was used for each evaluation after leaving to stand overnight.

<Evaluation of liquid crystal alignment> Using the liquid crystal cell before ISO treatment, those with initial flow alignment were defined as "poor", and those without this were defined as "good" for evaluation. <In-plane uniformity evaluation by comparison> The evaluation of the twist angle of the liquid crystal display element was performed using the OPTIPRO-micro manufactured by SHINTECH. The produced liquid crystal cell was placed on a measuring stage, and in a state in which no voltage was applied, 20 points were measured in the first pixel plane, and the standard deviation was calculated. In the evaluation system, those with a standard deviation of the torsion angle of 0.5 or more were defined as "poor", and those less than 0.5 were defined as "good" and evaluated.

<Evaluation of voltage holding ratio> The liquid crystal cell produced above was applied with a voltage of 1 V at 60° C. for 60 microseconds using an apparatus manufactured by Toyo Technica, and then the voltage holding ratio after 1,000 milliseconds was measured. At this time, when the voltage holding ratio was maintained at 90% or more, it was defined as "good", and when it was less than 90%, it was defined as "bad" and evaluated.

＜Evaluation results＞ The evaluation result is shown in Table 3 about the liquid crystal display element obtained using the liquid crystal aligning agent (1)-(12) and (R1)-(R5) obtained by the said Example 1-12 and the comparative example 1-5.

Claims (12)

A liquid crystal alignment agent for photo-alignment, characterized by containing at least one polymer (A) selected from the group consisting of polyimide precursors and imidized polymers thereof, the polymer (A) having At least one repeating unit (a1) selected from the group consisting of the repeating unit represented by the following formula (1-a) and the repeating unit represented by the following formula (1-i), and selected from the following formula (2- At least one repeating unit (a2) of the group consisting of the repeating unit represented by a) and the repeating unit represented by the following formula (2-i), and containing 1 to 20 mol% of the repeating unit ( a1);

(wherein, X ₁ represents a tetravalent organic group represented by the following formula (B), and X ₂ represents a tetravalent organic group represented by the following formula (C); R and Z independently represent a hydrogen atom or a carbon number of 1 The alkyl group of ~6; a plurality of R and Z, each of which may be the same or different; Y ₁ and Y ₂ independently represent a divalent organic group represented by the following formula (O));

(In the formula, R _b1 to R _b4 each independently represent a hydrogen atom, a halogen atom, or an alkyl group with 1 to 6 carbon atoms; L ₁ represents a single bond, -CH ₂ -, -(CH ₂ ) _n -(n is an integer from 2 to 18), or at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted by any one of -O-, -C(=O)- or -OC(=O)- R _c1 to R _c4 independently represent a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with a carbon number of 2 to 6, an alkynyl group with a carbon number of 2 to 6, and a group containing a fluorine atom. A monovalent organic group with 1 to 6 carbon atoms, or a phenyl group, _{at least one of R c1} to R _c4 represents a group other than the hydrogen atom in the above definition);

(Ar represents a benzene ring, a biphenyl structure, or a naphthalene ring, the two Ar can be the same or different, and any hydrogen atom on the ring can also be substituted by a monovalent organic group; Q ₂ represents -CH ₂ -, -(CH ₂ ) _n - (n is an integer of 2 to 18), or _{at least a part of -CH 2 - of the aforementioned -(CH 2} ) _n - is processed by -O-, -C(=O)- or -OC(=O) The group substituted by any one of -; p is an integer of 0 or 1; however, when p is 0, Ar represents a biphenyl structure, and when p is 1, at least one of the two Ars represents a naphthalene ring; * represents a bond part). The liquid crystal alignment agent for photo-alignment method according to claim 1, wherein the tetravalent organic group represented by the aforementioned formula (B) is the tetravalent organic group represented by the following formulas (b-1) to (b-2);

(* indicates the bond part). As claimed in claim 1, the liquid crystal alignment agent for photo-alignment method, wherein the divalent organic group represented by the aforementioned formula (O) is the divalent organic group represented by the following formulas (o-1) to (o-7);

. The liquid crystal alignment agent for photo-alignment method according to claim 1, wherein the polymer (A) has a repeating unit selected from the repeating unit represented by the following formula (3-a) and the repeating unit represented by the following formula (3-i) At least 1 repeating unit (a3) in groups;

(in the formula, X ₃ represents a tetravalent organic group, and Y ₃ represents a divalent organic group represented by the following formula (3d); R and Z are synonymous with the aforementioned formula (1-a));

(Ar ₃ represents a benzene ring or a biphenyl structure, the two Ars can be the same or different, and any hydrogen atom on the ring can also be substituted by a monovalent organic group; Q ₃ represents -(CH ₂ ) _n -(n is 2 An integer of ~18), or a group in which at least a part of -CH _{2 - of the aforementioned -(CH 2} ) _n - is substituted with any one of -O-, -C(=O)- or -OC(=O)- ; * indicates the bond site). The liquid crystal aligning agent for a photo-alignment method according to claim 1, wherein the polymer (A) has a repeating unit selected from the repeating unit represented by the following formula (4-a) and the repeating unit represented by the following formula (4-i) Groups of at least 1 repeating unit (a4);

(In the formula, R and Z are synonymous with the aforementioned formula (1-a); X ₄ represents a tetravalent organic group, Y ₄ represents a group having a group in the molecule "-N(D)-(D represents a urethane-based protection Divalent organic group with 6 to 30 carbon atoms). The liquid crystal alignment agent for photo-alignment method according to claim 5, wherein the aforementioned Y ₄ is a structure represented by the following formulae (Y4-1) to (Y4-4);

(Boc represents tert-butoxycarbonyl; * represents a bonding site). A liquid crystal alignment film, which is obtained from a liquid crystal alignment agent for a photo-alignment method according to any one of claims 1 to 6. A liquid crystal display element comprising the liquid crystal alignment film of claim 7. A method for manufacturing a liquid crystal alignment film, comprising the following steps (1) to (3); Step (1): the step of coating the liquid crystal alignment agent for the photo-alignment method according to any one of claims 1 to 6 on the substrate, Step (2): the step of heating the coated photo-alignment method with a liquid crystal alignment agent to obtain a film, Step (3): the step of irradiating polarized ultraviolet rays to the film obtained in step (2). The method for producing a liquid crystal alignment film of claim 9, further comprising the following step (4); Step (4): the step of firing the film obtained in the step (3) at a temperature above 100° C. and higher than the temperature in the step (2). The method for producing a liquid crystal alignment film according to claim 9, wherein the aforementioned step (2) is a step of obtaining the film by heating in a temperature range of 40 to 180°C. 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 9 to 11.