TW202244252A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

A liquid crystal aligning agent fulfilling at least one requirement selected from the group consisting of the following (I) and (II). (I): The liquid crystal aligning agent comprises a polymer (A) having repeating units selected from the group consisting of repeating units represented by formula (1-a) and repeating units represented by formula (1-i), and an epoxy compound (B) represented by formula (2). (II): The liquid crystal aligning agent comprises a reaction product between the polymer (A) and the epoxy compound (B).

Description

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

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

Liquid crystal display elements are widely used as display units of personal computers, mobile phones, smartphones, televisions, and the like. Liquid crystal display elements, for example, include: a liquid crystal layer sandwiched between the element substrate and the color filter substrate, pixel electrodes and common electrodes that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, Thin film transistor (TFT) etc. which switch the electrical signal supplied to the pixel electrode. Known methods for driving liquid crystal molecules include longitudinal electric field methods such as the TN method and the VA method, and transverse electric field methods such as the IPS method and the FFS method. The transverse electric field method in which electrodes are formed on only one side of the substrate and an electric field is applied parallel to the substrate has a wider field of view than the conventional vertical electric field method in which voltage is applied to the electrodes formed on the upper and lower substrates to drive the liquid crystal Angular characteristics are known as liquid crystal display elements capable of high-quality display.

If the stability of the liquid crystal alignment of the liquid crystal cell of the transverse electric field method is small, the liquid crystal will not return to the initial state when the liquid crystal is driven for a long time, which will cause a decrease in contrast and afterimages. Therefore, the stability of the liquid crystal alignment is important. In addition, static electricity is easy to accumulate in the liquid crystal cell, and the application of positive and negative asymmetric voltages generated by driving will also cause charge accumulation in the liquid crystal cell, which will cause confusion in the liquid crystal alignment and affect the display in the form of afterimages , so that the display quality of the liquid crystal element is significantly reduced. In addition, when the backlight illuminates the liquid crystal cell immediately after driving, it will also cause charge accumulation, so even if it is driven for a short time, image sticking will occur. In addition, problems such as flickering will occur during driving.

As a liquid crystal alignment agent that reduces charge accumulation, Patent Document 1 discloses a liquid crystal alignment agent containing a polymer obtained by polycondensing a specific diamine and an aliphatic tetracarboxylic acid derivative. [Prior Art Literature] [Patent Document]

[Patent Document 1] International Publication No. 2004/021076

[Problem to be solved by the invention]

After review, the inventor of this case understands that if the above-mentioned specific diamine is used as the raw material component of the polymer with a structure containing a nitrogen atom in the molecule, the speed of accumulating electric charges will be accelerated, but the absolute value of electric charges will be reduced increase. Especially in recent high-brightness liquid crystal display elements, the brightness of the backlight is increased, and the visibility of the residual image caused by the accumulated charge is also increased. Therefore, it is necessary to reduce the absolute value of the accumulated charge and reduce the generated charge in a short time. liquid crystal alignment film. In addition, the demand for a liquid crystal alignment film that reduces charge accumulation and flicker caused by backlight is also increasing more than before.

In view of the above, the object of the present invention is to provide a liquid crystal alignment film that can reduce the absolute value of the accumulated charge and reduce the generated charge in a short time, and can obtain a liquid crystal alignment film that reduces the charge accumulation and flicker caused by the backlight. Liquid crystal alignment agent. [How to solve the problem]

The inventors of the present case conducted various studies to achieve the above-mentioned purpose, and found that reducing the carboxyl group and imide ring structure in the liquid crystal alignment film is effective for achieving the above-mentioned purpose. And it was found that the obtained liquid crystal alignment agent with the following composition is the most suitable for achieving the above purpose, and completed the present invention.

式(1-a)及式(1-i)中，X ₁表示4價有機基。Y ₁表示2價有機基。2個R ₁及Z ₁各自獨立地表示氫原子、碳數1~6之烷基、碳數2~6之烯基、碳數2~6之炔基、第三丁氧基羰基、9-茀基甲氧基羰基、碳數1~6之烷基矽基、或前述烷基、前述烯基或前述炔基擁有之氫原子之至少一個被鹵素原子或硝基取代而得之1價有機基。R ₁、及Z ₁可相同也可不同。 [化2]

式(2)中，R ₁~R ₄各自獨立地表示氫原子、羥基、鹵素原子、硝基、氰基、碳數1~5之烷基、碳數2~5之烯基、碳數2~5之炔基、或前述烷基、前述烯基或前述炔基擁有之氫原子之至少一個被羥基、鹵素原子、硝基、或氰基取代而得之1價有機基。惟R ₁~R ₄中之至少一者表示氫原子以外之基。 Therefore, the present invention is based on the above-mentioned knowledge and has the following gist. One aspect of the present invention is a liquid crystal alignment agent which corresponds to at least one selected from the group consisting of the following (I) and (II). (I): A polymer (A) containing a repeating unit 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 the following formula ( 2) The epoxy compound (B) represented; (II): the reaction product containing the polymer (A) and the epoxy compound (B) (hereinafter also referred to as "modified polymer (2mp)"); [ chemical 1]

In formula (1-a) and formula (1-i), X ₁ represents a tetravalent organic group. Y ₁ represents a divalent organic group. The two R ₁ and Z ₁ each independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkenyl group with 2 to 6 carbons, an alkynyl group with 2 to 6 carbons, a tertiary butoxycarbonyl group, a 9- A monovalent organic methoxycarbonyl group, an alkylsilyl group having 1 to 6 carbon atoms, or at least one of the hydrogen atoms of the aforementioned alkyl group, the aforementioned alkenyl group, or the aforementioned alkynyl group is replaced by a halogen atom or a nitro group base. R ₁ and Z ₁ may be the same or different. [Chem 2]

In formula (2), R ₁ ~ R ₄ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkenyl group with 2 to 5 carbon atoms. ~5 alkynyl groups, or a monovalent organic group in which at least one of the hydrogen atoms possessed by the aforementioned alkyl, aforementioned alkenyl, or aforementioned alkynyl groups is substituted by a hydroxyl group, a halogen atom, a nitro group, or a cyano group. Only at least one of R ₁ to R ₄ represents a group other than a hydrogen atom.

式(1’-a)及式(1’-i)中，X _1’表示4價有機基。Y _1’表示具有選自由下式(d _Y’-1)表示之次結構、下式(d _Y’-2)表示之次結構、及含氮原子之雜環構成之群組中之至少1種次結構之2價有機基。2個R _1’及Z _1’各自獨立地表示氫原子、碳數1~6之烷基、碳數2~6之烯基、碳數2~6之炔基、第三丁氧基羰基、9-茀基甲氧基羰基、碳數1~6之烷基矽基、或前述烷基、前述烯基或前述炔基擁有之氫原子之至少一個被鹵素原子或硝基取代而得之1價有機基。R _1’、及Z _1’可相同也可不同。 [化4]

式(d _Y’-1)中，R表示氫原子或1價有機基。式(d _Y’-1)~(d _Y’-2)中，苯環上之任意氫原子也可被1價之取代基取代。＊表示原子鍵。 [化5]

式(2’)中，R _o表示碳數1~5之烷基、碳數2~5之烯基、碳數2~5之炔基、苯基、該烷基擁有之碳-碳鍵間導入-O-而成之1價有機基(q)、或前述烷基、前述烯基、前述炔基、前述苯基或前述1價有機基(q)擁有之氫原子中之至少一個被羥基、鹵素原子、硝基、或氰基取代而得之1價有機基。 又，本案整份說明書中，鹵素原子可列舉氟原子、氯原子、溴原子、碘原子等，＊表示原子鍵。 [發明之效果] Another aspect of the present invention is a liquid crystal alignment agent that meets at least one selected from the group consisting of the following (I') and (II') and the following (III'): (I'): containing A polymer (A') having a repeating unit 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 the following formula (2' ) represented by the epoxy compound (B'), (II'): the reaction product containing the polymer (A') and the epoxy compound (B') (hereinafter also referred to as "modified polymer (2mp') "), (III'): The amount of the epoxy compound represented by the formula (2') is 0.1 parts by mass relative to the total of 100 parts by mass of the polymer (A') and other polymers other than the polymer (A') ~50 parts by mass, [Chem. 3]

In formula (1'-a) and formula (1'-i), X _1' represents a tetravalent organic group. Y _1' represents at least 1 selected from the group consisting of the substructure represented by the following formula (d _Y' -1), the substructure represented by the following formula (d _Y' -2), and a heterocyclic ring containing a nitrogen atom. The divalent organic group of the substructure. The two R _1' and Z _1' each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, an alkenyl group having 2 to 6 carbons, an alkynyl group having 2 to 6 carbons, a tertiary butoxycarbonyl group, 9-Oxylmethoxycarbonyl, an alkylsilyl group having 1 to 6 carbon atoms, or at least one of the hydrogen atoms of the aforementioned alkyl, aforementioned alkenyl, or aforementioned alkynyl group is replaced by a halogen atom or a nitro group1 Valence organic base. R _1' and Z _1' may be the same or different. [chemical 4]

In the formula (d _Y' -1), R represents a hydrogen atom or a monovalent organic group. In the formulas (d _Y' -1)~(d _Y' -2), any hydrogen atom on the benzene ring can also be substituted by a monovalent substituent. * Indicates an atomic bond. [chemical 5]

In formula (2'), R _o represents an alkyl group having 1 to 5 carbons, an alkenyl group having 2 to 5 carbons, an alkynyl group having 2 to 5 carbons, a phenyl group, or a carbon-carbon bond between the alkyl groups. At least one of the hydrogen atoms of the monovalent organic group (q) formed by introducing -O-, or the aforementioned alkyl group, the aforementioned alkenyl group, the aforementioned alkynyl group, the aforementioned phenyl group, or the aforementioned monovalent organic group (q) is replaced by a hydroxyl group , a halogen atom, a nitro group, or a monovalent organic group substituted with a cyano group. In addition, in the whole specification of this case, a halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and * represents an atomic bond. [Effect of Invention]

By using the liquid crystal alignment agent of the present invention, it is possible to obtain a liquid crystal alignment film that can reduce the absolute value of accumulated charges and reduce generated charges in a short time, and a liquid crystal alignment film that reduces charge accumulation and flicker caused by backlight.

＜Polymer (A)＞ The polymer (A) is a polymer having a repeating unit selected from the group consisting of the repeating unit represented by the above formula (1-a) and the repeating unit represented by the above formula (1-i).

<Repeating unit represented by formula (1-a)> In the above formula (1-a), X ₁ represents a tetravalent organic group. The quaternary organic group can be exemplified by a quaternary organic group derived from an aliphatic tetracarboxylic dianhydride or a derivative thereof, a quaternary organic group derived from an alicyclic tetracarboxylic dianhydride or a derivative thereof, or a quaternary organic group derived from an aromatic tetracarboxylic dianhydride. Tetravalent organic group of acid dianhydride or its derivatives. Derivatives of tetracarboxylic dianhydrides, such as tetracarboxylic acid dihalides, tetracarboxylic dialkyl esters, and tetracarboxylic acid dialkyl dihalides. Here, the aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecularly dehydrating four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. Aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of 4 carboxyl groups bonded to a chain hydrocarbon structure. However, it does not need to be composed only of a chain hydrocarbon structure, and a part thereof may have an alicyclic structure or an aromatic ring structure. Moreover, an alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecularly dehydrating four carboxyl groups including at least one carboxyl group to which an alicyclic structure is bonded. But these 4 carboxyl groups are not bonded to the aromatic ring. Moreover, it does not need to consist only of an alicyclic structure, and a part may have a chain hydrocarbon structure and an aromatic ring structure.

The aforementioned X ₁ is preferably a tetravalent organic group derived from tetracarboxylic dianhydride represented by the following formula (t) or a derivative thereof.

式(t)中X _T係選自下式(X1-1)~(X1-25)之結構。＊表示原子鍵。 [chemical 6]

In the formula (t), X _T is selected from the structures of the following formulas (X1-1)~(X1-25). * Indicates an atomic bond.

[chemical 7]

[chemical 8]

[chemical 9]

[chemical 10]

In the formulas (X1-1)~(X1-4), R1~ _R21 each independently represent a hydrogen atom, a halogen atom, an alkyl group with ₁ ~6 carbons, an alkenyl group with 2~6 carbons, or an alkenyl group with 2 carbons. ~6 alkynyl groups, monovalent organic groups with 1 to 6 carbon atoms containing fluorine atoms, or phenyl groups. In consideration of liquid crystal alignment, R ₁ to R ₂₁ are preferably hydrogen atoms, halogen atoms, methyl groups, or ethyl groups, and hydrogen atoms or methyl groups are more preferable. In the formulas (X1-24)~(X1-25), j and k are integers of ₀ or ₁ , and A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, phenylene group, sulfonyl group, or amido group. A plurality of A ₂ may each be the same or different.

Specific examples of the formula (X1-1) include the following formulas (1-1) to (1-6). Considering the viewpoint of improving the liquid crystal alignment, (1-1) is particularly preferable. ＊It is synonymous with the above.

[chemical 11]

[化13]

Desirable specific examples of the above formulas (X1-24) and (X1-25) include the following formulas (X1-26) to (X1-41). ＊It is synonymous with the above. [chemical 12]

[chemical 13]

Considering the point of view of improving liquid crystal alignment, the above X _T is the above formula (X1-1)~(X1-10), (X1-18)~(X1-23), or (X1-24)~(X1-25) Ideally, the above formula (X1-1), (X1-5), (X1-7)~(X1-10), (X1-21), (X1-23), or (X1-24)~(X1 -25) More preferably, the above formula (1-1), (1-2), (X1-5), (X1-7), (X1-8), (X1-9), or (X1-26) ~(X1-30) is more ideal.

Formula (1-a) may be a tetravalent organic group derived from a tetracarboxylic dianhydride other than the above formula (t) or a derivative thereof.

In the above formula (1-a), Y ₁ represents a divalent organic group. Specific examples of the divalent organic group of Y ₁ include divalent organic groups obtained by removing two amine groups from the following diamines.

Diamines represented by the following formula (O); diamines with photoalignment groups such as 4,4'-diaminoazobenzene or diaminodiphenylacetylene; the following formulas (h-1)~(h- 8) Diamines with amide bonds or urea bonds such as diamines; 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino Aminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, diamine represented by the following formula (d _o ); it is selected from the group consisting of nitrogen-containing heterocycle, secondary amino group and tertiary amino group Diamines with at least one nitrogen-atom-containing structure (hereinafter also referred to as nitrogen-atom-containing structure) (except that there is no amine group bonded to a protecting group that is detached by heating and replaced by a hydrogen atom in the molecule); 2, 4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol; 4, 4'-diamino-3,3'-dihydroxybiphenyl, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid and the following formula ( 3b-1)~Diamines represented by formula (3b-4) and other diamines with carboxyl groups; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1- (4-aminophenyl)-1,3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3 ,3-Trimethyl-1H-inden-6-amine; 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallyl Diamines with photopolymerizable groups at the end such as phenylaniline; cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy Cholesteryl-2,4-diaminobenzoate, cholestyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanosteryl 3,5-diaminobenzoate Diamines with steroid skeletons such as alkyl esters and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulas (V-1)~(V-6); Formulas (5-1)~(5-11) and other groups "-N(D)-" (D represents a protecting group that will be removed by heating and replaced by a hydrogen atom, preferably tertiary butoxycarbonyl.) diamines; 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, diamines represented by the following formula (Ds-1) and other diamines with siloxane bonds; the following formula (Ox -1)~(Ox-2) and other diamines with oxazoline structure; m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine Methyldiamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), International Publication No. 2018/ Diamine, etc. in which the group represented by any one of the formulas (Y-1) to (Y-167) described in No. 117239 has two amine groups bonded thereto.

式(O)中，Ar表示2價之苯環、聯苯結構、或萘環。2個Ar可相同也可不同，Ar中之上述環上之任意氫原子也可被1價取代基取代。p為0或1之整數。Q ₂表示-(CH ₂) _n-(n為2~18之整數。)、或該-(CH ₂) _n-之-CH ₂-之至少一部分被-O-、-C(＝O)-及-O-C(＝O)-中之任一者取代而得之基。 1價之取代基，例如：鹵素原子、羥基、碳數1~6之烷基、碳數2~6之烯基、碳數1~6之烷氧基、碳數1~6之氟烷基、碳數2~6之氟烯基、碳數1~6之氟烷氧基、羧基、碳數2~6之烷氧基羰基、氰基、硝基等。 [chemical 14]

In formula (O), Ar represents a divalent benzene ring, a biphenyl structure, or a naphthalene ring. The two Ars may be the same or different, and any hydrogen atom on the above-mentioned ring in Ar may be substituted by a monovalent substituent. p is an integer of 0 or 1. Q ₂ represents -(CH ₂ ) _n - (n is an integer from 2 to 18.), or at least a part of -CH ₂ - of the -(CH ₂ ) _n - is replaced by -O-, -C(=O)- A group obtained by substituting any one of -OC(=O)-. Monovalent substituents, such as: halogen atom, hydroxyl group, alkyl group with 1~6 carbons, alkenyl group with 2~6 carbons, alkoxyl group with 1~6 carbons, fluoroalkyl group with 1~6 carbons , Fluoroalkenyl with 2 to 6 carbons, fluoroalkoxy with 1 to 6 carbons, carboxyl, alkoxycarbonyl with 2 to 6 carbons, cyano, nitro, etc.

[chemical 15]

式(d _O)中，m有多個存在時，多個m可各相同也可不同。 [chemical 16]

In the formula (d _O ), when a plurality of m exists, each of the plurality of m may be the same or different.

式(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-、-OCH ₂-、-COO-、-OCO-、-CO-N(CH ₃)-或-N(CH ₃)-CO-，m1及m2各自獨立地為0~4之整數且m1＋m2為1~4之整數。 式(3b-2)中，m3及m4各自獨立地為1~5之整數。 式(3b-3)中，A ²表示碳數1~5之直鏈或分支烷基，m5為1~5之整數。 式(3b-4)中，A ³及A ⁴各自獨立地表示單鍵、-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為1~4之整數。 [chemical 17]

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-, -CO-N (CH ₃ )- or -N(CH ₃ )-CO-, m1 and m2 are each independently an integer of 0 to 4, and m1+m2 is an integer of 1 to 4. In formula (3b-2), m3 and m4 are each independently an integer of 1-5. In the formula (3b-3), A ² represents a linear or branched alkyl group with 1 to 5 carbon atoms, and m5 is 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 -, -CO-N(CH ₃ )- or -N(CH ₃ )-CO-, m6 is an integer of 1-4.

式(V-1)~(V-6)中，X ^v1~X ^v4、及X ^p1~X ^p2各自獨立地表示-(CH ₂) _a-(a為1~15之整數。)、-CONH-、-NHCO-、-CO-N(CH ₃)-、-NH-、-O-、-CH ₂O-、-CH ₂-OCO-、-COO-、或-OCO-，X ^v5表示-O-、-CH ₂O-、-CH ₂-OCO-、-COO-、或-OCO-。X _a表示單鍵、-O-、-NH-、-O-(CH ₂) _m-O-(m表示1~6之整數。)、-C(CH ₃) ₂-、-CO-、-(CH ₂) _m-(m表示1~6之整數。)、-SO ₂-、-O-C(CH ₃) ₂-、-CO-(CH ₂) _m-(m表示1~6之整數。)、-NH-(CH ₂) _m-(m表示1~6之整數。)、-SO ₂-(CH ₂) _m-(m表示1~6之整數。)、-CONH-(CH ₂) _m-(m表示1~6之整數。)、-CONH-(CH ₂) _m-NHCO-(m表示1~6之整數。)、-COO-(CH ₂) _m-OCO-(m表示1~6之整數。)、-CONH-、-NH-(CH ₂) _m-NH-(m表示1~6之整數。)、或-SO ₂-(CH ₂) _m-SO ₂-(m表示1~6之整數。)，R ^v1~R ^v4、及R ^1a~R ^1b各自獨立地表示碳數1~20之烷基、碳數1~20之烷氧基或碳數2~20之烷氧基烷基。2個k可相同也可不同。 [化19]

Boc表示第三丁氧基羰基。 [化20]

[chemical 18]

In formulas (V-1) to (V-6), X ^v1 to X ^v4 and X ^p1 to X ^p2 each independently represent -(CH ₂ ) _a -(a is an integer of 1 to 15.), -CONH -, -NHCO-, -CO-N(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -CH ₂ -OCO-, -COO-, or -OCO-, X ^v5 means - O-, _-CH2O- , _-CH2 -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.), -C(CH ₃ ) ₂ -, -CO-, - (CH ₂ ) _m -(m represents an integer from 1 to 6.), -SO ₂ -, -OC(CH ₃ ) ₂ -, -CO-(CH ₂ ) _m -(m represents an integer from 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 of 1~6.), -CONH-(CH ₂ ) _m -NHCO-(m represents an integer of 1~6.), -COO-(CH ₂ ) _m -OCO-(m represents 1~ Integer of 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 1 ~6 integers.), R ^v1 ~R ^v4 , and R ^1a ~ R ^1b each independently represent an alkyl group with 1 to 20 carbons, an alkoxy group with 1 to 20 carbons, or an alkoxy group with 2 to 20 carbons base alkyl. The two k's may be the same or different. [chemical 19]

Boc represents tertiary butoxycarbonyl. [chemical 20]

[chem 21]

For the diamine represented by the above formula (d _o ), considering the viewpoint of improving the liquid crystal alignment, the diamine represented by the following formula (d _o -1)~(d _o -6), 3,3'-diaminodiphenyl Ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether are preferable. [chem 22]

In the diamine represented by the above formula (O), arbitrary hydrogen atoms of a benzene ring, a biphenyl structure, or a naphthalene ring may be substituted with a monovalent substituent. Substituents for the above rings, for example: halogen atom, alkyl group with 1~10 carbons, alkenyl group with 2~10 carbons, alkoxyl group with 1~10 carbons, fluoroalkyl group with 1~10 carbons, carbon Fluoroalkenyl with 2-10 carbons, fluoroalkoxy with 1-10 carbons, alkoxycarbonyl with 1-10 carbons, cyano, nitro, etc.

[化24]

[化25]

Regarding the diamine represented by the above formula (O), the diamine represented by any one of the following formulas (o-1) to (o-16) is preferable from the viewpoint of improving liquid crystal alignment. [chem 23]

[chem 24]

[chem 25]

The nitrogen-containing heterocycles that the above-mentioned diamines with nitrogen-containing structures may also have, for example: pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridine, pyridine, indole, benzimidazole, Purine, quinoline, isoquinoline, quinidine, quinoline, phthalein, trisulfide, carbazole, acridine, piperidine, piperidine, pyrrolidine, hexamethyleneimine. Among these, pyridine, pyrimidine, pyridine, piperidine, piperidine, quinoline, carbazole or acridine are preferable.

上式(n)中，R表示氫原子或碳數1~10之1價烴基。「＊」表示鍵結於烴基之原子鍵，且至少一者係和芳香族烴基鍵結。 The secondary and tertiary amino groups that the above-mentioned diamine having a structure containing a nitrogen atom may also have are, for example, represented by the following formula (n). [chem 26]

In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*" indicates an atomic bond bonded to a hydrocarbon group, and at least one of them is bonded to an aromatic hydrocarbon group.

Monovalent hydrocarbon groups for R in the above formula (n), for example: alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and tolyl, etc. R is preferably a hydrogen atom or a methyl group.

[化28]

[化29]

Specific examples of the above-mentioned diamines with structures containing nitrogen atoms, such as: 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminopyridine Carbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperone, 3,6-diaminoacridine, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, diamine represented by the following formula (Dp-1)~(Dp-8), the following formula (z-1 ) ~ the diamine represented by formula (z-13). [chem 27]

[chem 28]

[chem 29]

With respect to the above Y ₁ , in consideration of improving the alignment of liquid crystals, it may be selected from diamines represented by the above formula (O), diamines having amide bonds or urea bonds, and 3,3'-diaminodiphenyl Methane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ketone, 1,4-bis(4- Aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, diamine represented by the above formula (d _o ), 4- (2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, and the group "-N(D)-" (D represents a protecting group that is removed by heating and replaced by a hydrogen atom) , preferably tertiary butoxycarbonyl.) The diamines in the group consisting of diamines have taken away two divalent organic groups from amine groups.

For Y ₁ in the formula (1-a), considering the absolute value of the accumulated charge and the reduction of the generated charge in a short time, it can also be selected from the above-mentioned diamine having a structure containing a nitrogen atom, 2, 4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, and the above The diamines in the group consisting of diamines having carboxyl groups have taken away the divalent organic groups of two amine groups.

In the above formula (1-a), specific examples of R1 and Z1's alkyl group having ₁ to ₆ carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, third Butyl, pentyl, isopentyl, neopentyl, cyclopentyl, hexyl, cyclohexyl. Specific examples of alkenyl groups with 2 to ₆ carbon atoms in R1 and Z1 include vinyl, allyl, ₁ -propenyl, isopropenyl, 1-butenyl, 2-butenyl, isobutenyl, 1,3-butadienyl, 2-pentenyl, hexenyl, cyclohexenyl, etc. Specific examples of the alkynyl group having 2 to 6 carbon atoms in R ₁ and Z ₁ include ethynyl, 1-propynyl, 2-propynyl and the like. The alkylsilyl groups with 1-6 carbon atoms in R ₁ and Z ₁ include trimethylsilyl, triethylsilyl, dimethylethylsilyl, isopropyldimethylsilyl, tributylsilyl Dimethylsilyl. From the viewpoint of obtaining the effects of the present invention, R ₁ and Z ₁ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbons, more preferably a hydrogen atom or a methyl group. R ₁ and Z ₁ may each be one type or two or more types.

<Repeating unit represented by formula (1-i)> In the above formula (1-i), X ₁ represents a tetravalent organic group, and Y ₁ represents a divalent organic group. Specific examples and ideal aspects of X ₁ and Y ₁ are the same as X ₁ and Y ₁ in the above formula (1-a).

<Polymer (A')> The polymer (A') has a repeating unit selected from the group consisting of the repeating unit represented by the above formula (1'-a) and the repeating unit represented by the above formula (1'-i). Polymers of repeating units.

<Repeating unit represented by formula (1'-a)> In the above formula (1'-a), X _1' represents a tetravalent organic group. Specific examples of the tetravalent organic group include the tetravalent organic group exemplified in X ₁ of the above formula (1′-a).

式(d _Y’-1)中，R表示氫原子或1價有機基。式(d _Y’-1)~(d _Y’-2)中，苯環上之任意氫原子也可被1價之取代基取代。＊表示原子鍵。 In the above formula (1'-a), Y _1' means having a substructure selected from the substructure represented by the following formula (d _Y' -1), the substructure represented by the following formula (d _Y' -2), and a nitrogen-containing atom A divalent organic group of at least one substructure in the group consisting of a heterocycle. [chem 30]

In the formula (d _Y' -1), R represents a hydrogen atom or a monovalent organic group. In the formulas (d _Y' -1)~(d _Y' -2), any hydrogen atom on the benzene ring can also be substituted by a monovalent substituent. * Indicates an atomic bond.

Monovalent substituents of the benzene ring in the above formula (d _Y' -1)~(d _Y' -2), such as: halogen atom, hydroxyl, alkyl group with 1~6 carbons, alkenes with 2~6 carbons group, alkoxy group with 1~6 carbons, fluoroalkyl group with 1~6 carbons, fluoroalkenyl group with 2~6 carbons, fluoroalkoxy group with 1~6 carbons, carboxyl, 2~6 carbons Alkoxycarbonyl, cyano, nitro, etc.

The monovalent organic group of R in the above formula (d _Y' -1) includes a monovalent hydrocarbon group with 1 to 10 carbon atoms, and -O-, -COO-, -CO-, -NHCO-, -S-, -NH- functional groups such as monovalent groups, monovalent aromatic heterocyclic groups, and protective groups for amine groups. The monovalent organic group of R in the above formula (d _Y' -1) is preferably a monovalent hydrocarbon group with 1 to 10 carbons, more preferably an alkyl group with 1 to 5 carbons, or an alkenyl group with 2 to 5 carbons , an alkynyl group having 2 to 5 carbon atoms, or a phenyl group.

Y _1' of the above formula (1'-a) has a substructure selected from the substructure represented by the above formula (d _Y' -1) in at least one of the main chain direction and the side chain direction of the polymer (A') , At least one substructure in the group consisting of the substructure represented by (d _Y' -2) and the nitrogen atom-containing heterocycle. In addition, Y _1' may have 1, 2, or 3 or more of the above-mentioned substructures. Y _1' preferably has the above-mentioned substructure in the main chain direction of the polymer (A').

Specific examples of the nitrogen-atom-containing heterocycle include the nitrogen-atom-containing heterocycle exemplified for the above-mentioned diamine having a nitrogen-atom-containing structure.

Y _1' is preferably a divalent organic group in which two amine groups are removed from the diamine having a structure containing a nitrogen atom as exemplified in the above polymer (A), or a divalent organic group represented by the above formula (d _Y' -2) 2-valent organic group. A polymer (A') having a divalent organic group represented by the above formula (d _Y' -2) as Y _1' , for example, can be made into a polymer (A') by bonding each atom to a diamine bonded to an amine group ) is obtained by using raw materials.

苯環上之任意氫原子也可被1價之取代基取代。＊表示原子鍵。 The preferable structures of the divalent organic groups represented by the above formula (d _Y' -2) include the divalent organic groups represented by the following formulas (2d _Y' -1)~(2d _Y' -3). [chem 31]

Any hydrogen atom on the benzene ring may also be substituted by a monovalent substituent. * Indicates an atomic bond.

Specific examples of the monovalent substituents in the above formulas (2d _Y' -1)~(2d _Y' -3) include the monovalent substituents in the above formulas (d _Y' -1)~(d _Y' -2) The structure of the base example.

In the above formula (1'-a), specific examples of alkyl groups with 1 to 6 carbon atoms in R _1' ^and Z _1' include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl , Tertiary butyl, pentyl, isopentyl, neopentyl, cyclopentyl, hexyl, cyclohexyl. Specific examples of alkenyl groups with 2 to 6 carbon atoms in R _1' and Z _1' include vinyl, allyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, and isobutene 1,3-butadienyl, 2-pentenyl, hexenyl, cyclohexenyl, etc. Specific examples of the alkynyl group having 2 to 6 carbon atoms in R _1' and Z _1' include ethynyl, 1-propynyl, 2-propynyl and the like. The alkylsilyl groups with 1-6 carbon atoms in R _1' and Z _1' include trimethylsilyl, triethylsilyl, dimethylethylsilyl, isopropyldimethylsilyl, Tributyldimethylsilyl. R _1' and Z _1' are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbons, and more preferably a hydrogen atom or a methyl group, in view of obtaining the effects of the present invention. R _1' and Z _1' may each be one type or two or more types.

<Repeating unit represented by formula (1'-i)> In the above formula (1'-i), X _1' represents a tetravalent organic group, and Y _1' represents a divalent organic group. Specific examples and ideal aspects of X _{1 '} and Y _{1 '} are the same as X 1' and Y 1' in the above formula (1'-a).

<Compound (B) represented by formula (2)> The epoxy compound (B) represented by formula (2) is a compound represented by formula (2). By using the epoxy compound having a specific structure represented by formula (2) in combination with the polymer (A), or using it as a raw material for the modified polymer (2mp), the obtained liquid crystal alignment film can be given the ability to reduce the accumulated charge. Absolute value and the effect of the short-term reduction of the charge that will occur. In addition, the effect of reducing charge accumulation and flicker caused by backlight can be imparted to the liquid crystal alignment film. In addition, the epoxy compound represented by the formula (2) of the present invention has the special effect of suppressing the change of the pretilt angle of the liquid crystal and the reduction of the voltage retention rate obtained by adding it.

Specific examples of alkyl groups having 1 to 5 carbon atoms in R ₁ to R ₄ of the above formula (2) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl , Pentyl, isopentyl, neopentyl, cyclopentyl, etc.

Specific examples of alkenyl groups having 2 to 5 carbon atoms in R ₁ to R ₄ of the above formula (2) include vinyl, allyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butane Alkenyl, isobutenyl, 1,3-butadienyl, 2-pentenyl, etc.

Specific examples of the alkynyl group having 2 to 5 carbon atoms of R ₁ to R ₄ in the above formula (2) include ethynyl, 1-propynyl, 2-propynyl and the like.

Desirable specific examples of the epoxy compound represented by the above formula (2) include compounds represented by the following formulas (e2-1) to (e2-25), but are not limited thereto. The said epoxy compound can be used individually or in combination of 2 or more types. [chem 32]

<Compound (B') represented by formula (2')> The epoxy compound (B') represented by the formula (2') is a compound represented by the above formula (2'). By using the epoxy compound having a specific structure represented by the formula (2') in combination with the polymer (A'), or using it as a raw material for the modified polymer (2mp'), it is possible to impart reduced accumulation to the obtained liquid crystal alignment film The absolute value of the charge and the effect of the short-term reduction of the charge that will occur. In addition, the effect of reducing charge accumulation and flicker due to backlight can be given to the liquid crystal alignment film. In addition, the epoxy compound represented by the formula (2') of the present invention has the special effect of suppressing the change of the pretilt angle of the liquid crystal and the reduction of the voltage retention rate by adding it.

Specific examples of the alkyl group having 1 to 5 carbon atoms in R ₀ of the above formula (2′) include structures exemplified by R ₁ to R ₄ of the above formula (2).

Specific examples of the alkenyl group having 2 to 5 carbon atoms in R ₀ of the above formula (2′) include structures exemplified by R ₁ to R ₄ of the above formula (2).

Specific examples of the alkynyl group having 2 to 5 carbon atoms in R ₀ of the above formula (2′) include structures exemplified by R ₁ to R ₄ of the above formula (2).

Desirable specific examples of the epoxy compound represented by the above formula (2') include compounds represented by the following formulas (e2'-1) to (e2'-11), but are not limited thereto. The said epoxy compound can be used individually or in combination of 2 or more types. [chem 33]

One embodiment of the liquid crystal alignment agent of the present invention corresponds to at least one selected from the group consisting of the following (I) and (II). (I): Contains a polymer (A) and an epoxy compound (B) represented by formula (2). (II): Contains the reaction product [modified polymer (2mp)] of the polymer (A) and the epoxy compound (B). In addition, in the liquid crystal alignment agent, the amount of the epoxy compound represented by the formula (2) is not particularly limited, and is 0.1 to 50 parts by mass relative to the total of 100 parts by mass of the polymer (A) and other polymers other than the polymer (A). Parts by mass are ideal, more preferably 1 to 30 parts by mass, and more preferably 5 to 30 parts by mass. Here, "the amount of the epoxy compound represented by the formula (2)" refers to the amount of the epoxy compound represented by the formula (2) in the liquid crystal alignment agent and the formula (2) constituting the modified polymer (2mp) Indicates the total amount of the amount of epoxy compound. Also, the polymer (A) in "100 parts by mass of the total of the polymer (A) and other polymers other than the polymer (A)" refers to the polymer (A) in the liquid crystal alignment agent and the modified polymer Polymer (A) of substance (2mp). So for example: when the liquid crystal alignment agent only contains 100 parts by mass of the polymer (A), 10 parts by mass of the epoxy compound (B), and 2000 parts by mass of the solvent, the amount of the epoxy compound represented by the formula (2) of the liquid crystal alignment agent is relatively 100 parts by mass of the total of the polymer (A) and other polymers other than the polymer (A) is 10 parts by mass. Also, for example: the liquid crystal alignment agent only contains 120 parts by mass of modified polymer (2mp), 100 parts by mass of other polymers (excluding polymer (A) and modified polymer (2mp).), and 4000 parts by mass of solvent and the modified polymer (2mp) is the reaction product of 100 parts by mass of the polymer (A) and 20 parts by mass of the epoxy compound (B), the amount of the epoxy compound represented by the formula (2) of the liquid crystal alignment agent is relative to The total of 100 parts by mass of the polymer (A) and other polymers other than the polymer (A) is 10 parts by mass.

One embodiment of the liquid crystal alignment agent of the present invention is at least one selected from the group consisting of the following (I') and (II') and the following (III'). (I'): Contains a polymer (A') and an epoxy compound (B') represented by formula (2'). (II'): Contains a reaction product [modified polymer (2mp')] of a polymer (A') and an epoxy compound (B'). (III'): The amount of the epoxy compound represented by the formula (2') is 0.1 to 50 parts by mass relative to 100 parts by mass of the total of the polymer (A') and other polymers other than the polymer (A'). Here, "the amount of epoxy compound represented by the formula (2')" refers to the amount of the epoxy compound represented by the formula (2') in the liquid crystal alignment agent and the formula that constitutes the modified polymer (2mp') (2') The total amount of epoxy compounds represented. Also, the polymer (A') in "100 parts by mass of the total of the polymer (A') and other polymers other than the polymer (A')" refers to the polymer (A') in the liquid crystal alignment agent and The polymer (A') constituting the modified polymer (2mp'). So for example: when the liquid crystal alignment agent only contains 100 parts by mass of the polymer (A'), 10 parts by mass of the epoxy compound (B'), and 2000 parts by mass of the solvent, the epoxy compound represented by the formula (2') of the liquid crystal alignment agent The quantity is 10 mass parts with respect to the total of 100 mass parts of polymers other than a polymer (A') and a polymer (A'). Also, for example: the liquid crystal alignment agent only contains 120 parts by mass of the modified polymer (2mp'), 100 parts by mass of other polymers (but not including the polymer (A') and the modified polymer (2mp').), and When the solvent is 4000 parts by mass, and the modified polymer (2mp') is the reaction product of 100 parts by mass of the polymer (A') and 20 parts by mass of the epoxy compound (B'), the formula (2') in the liquid crystal alignment agent The quantity of the epoxy compound shown is 10 mass parts with respect to a total of 100 mass parts of polymers other than a polymer (A') and a polymer (A').

In the above (III'), the amount of the epoxy compound represented by the formula (2') is 0.1 to 50 parts by mass relative to the total of 100 parts by mass of the polymer (A') and other polymers other than the polymer (A') , 5 to 50 parts by mass is more ideal, and 10 to 50 parts by mass is more ideal.

<Combined use of polymer and epoxy compound or modified polymer> One embodiment of the liquid crystal alignment agent of the present invention corresponds to at least one selected from the group consisting of the following (I) and (II). (I): Contains a polymer (A) and an epoxy compound (B) represented by formula (2). (II): Contains the reaction product [modified polymer (2mp)] of the polymer (A) and the epoxy compound (B).

One embodiment of the liquid crystal alignment agent of the present invention is at least one selected from the group consisting of the following (I') and (II') and the following (III'). (I'): Contains a polymer (A') and an epoxy compound (B') represented by formula (2'). (II'): Contains a reaction product [modified polymer (2mp')] of a polymer (A') and an epoxy compound (B'). (III'): The amount of the epoxy compound represented by the formula (2') is 0.1 to 50 parts by mass relative to 100 parts by mass of the total of the polymer (A') and other polymers other than the polymer (A').

In each embodiment of the liquid crystal alignment agent of the present invention, by adopting such a configuration, the effect of reducing the accumulated charge of the obtained liquid crystal alignment film is increased. The reason for obtaining the above effect is not clear. It is believed that the reaction between the specific epoxy compound and the carboxylic acid or amide group of the polymer (A) or polymer (A') hinders the thermal amide that occurs when the liquid crystal alignment agent is calcined. Imination, the reason for the reduction of the imide ring. In addition, compared to the form in which the polymer and the epoxy compound are used together, in the form of the modified polymer, the specific epoxy compound can be more efficiently combined with the carboxylic acid of the polymer (A) or the polymer (A') or Amide group reaction, so thermal imidization will be more inhibited, and the effect of reducing charge accumulation will be increased, so it is more ideal.

In this specification, "modified polymer (2mp)" also includes active hydrogen-containing groups (carboxyl groups, amine groups, hydroxyl groups, amide groups, etc.) possessed by polymer (A) and epoxy compounds represented by formula (2) It is obtained by partial reaction of the epoxy group. Here, "partial reaction" refers to the state in which the reaction between the epoxy group and all active hydrogen-containing groups proceeds and stops before becoming a modified polymer, and it also includes a part of the modified polymer that is not modified. The polymer, the polymer (A) and/or the epoxy compound represented by the formula (2) may remain. E.g: (1): A partially modified polymer of the epoxy compound represented by the polymer (A) and the formula (2), (2): A partially modified polymer of the polymer (A) and the epoxy compound represented by the formula (2), a mixture of the remaining polymer (A) and the remaining epoxy compound represented by the formula (2), (3): a mixture of polymer (A) and partially modified epoxy compound represented by formula (2), and remaining polymer (A), (4): A mixture of polymer (A) and the partially modified epoxy compound represented by formula (2) and the remaining epoxy compound represented by formula (2) etc. are also included in the aspect of the "modified polymer (2mp)" of the liquid crystal composition of the present invention. In addition, "modified polymer (2mp')" means that in the above description of "modified polymer (2mp)", polymer (A) is replaced by polymer (A'), and the formula (2) represents The epoxy compound is replaced with the content of the epoxy compound represented by formula (2').

The modified polymer (2mp) is obtained by reacting the polymer (A) with the epoxy compound represented by the formula (2). The modified polymer (2mp'), which is the reaction product of the mixture of the polymer (A') and the epoxy compound represented by the formula (2'), is also obtained by the same means.

In the mixture of the polymer (A) and the epoxy compound represented by the formula (2) when the modified polymer (2mp) is obtained, the blending ratio of the polymer (A) and the epoxy compound represented by the formula (2) is not particularly Restricted, relative to 1 molar part of the amide acid group of the polymer (A), the epoxy compound represented by formula (2) is preferably 0.05 ~ 2 molar parts, more preferably 0.1 ~ 1.5 molar parts, and more preferably Preferably it is 0.2~1.2 mol parts.

In the mixture of the polymer (A') and the epoxy compound represented by the formula (2') when the modified polymer (2mp') is obtained, the difference between the polymer (A') and the epoxy compound represented by the formula (2') The blending ratio is not particularly limited, and the epoxy compound represented by formula (2') is preferably 0.05~2 mole parts, more preferably 0.1~2 mole parts relative to 1 mole part of the amide acid group of the polymer (A'). 1.5 molar parts, more preferably 0.2~1.2 molar parts.

In order to obtain the reaction of the polymer (A) of the modified polymer (2mp) and the epoxy compound represented by the formula (2), the mixture of the epoxy compound represented by the polymer (A) and the formula (2) can be 20~120°C, preferably 20~100°C, stirring for 0.5~120 hours, preferably stirring for 1~72 hours. The modified polymer (2mp') which is the reaction product of the mixture of the polymer (A') and the epoxy compound represented by the formula (2') is also obtained by the same method.

<Method for producing polymers (A) and (A')> The polymer (A) (or (A')) used in the present invention is represented by the above formula (1-a) (or (1'-a) When the polyimide precursor of the repeating unit, for example, can be synthesized according to the known method as described in International Publication 2013/157586. If polymer (A) is taken as an example, it has R ₁ is the formula (1 - When the polyamic acid of the repeating unit represented by a) can be obtained by making the above-mentioned diamine and tetracarboxylic dianhydride react in a solvent (polycondensation). Also, have R ₁ as a base other than a hydrogen atom In the case of the polyamic acid ester of the repeating unit represented by the above formula (1-a), for example, the method of [I] reacting the polyamic acid obtained by the above synthesis reaction with an esterifying agent, [II] making tetracarboxylic A method of reacting an acid diester with a diamine, [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine, and the like.

In addition, the polyimide having the repeating unit represented by the above formula (1-i) (or (1'-i)) can be obtained by ring-closing (imidization) the above-mentioned polyimide precursor . Also, the imidization rate referred to in this specification, if taking the polymer (A) as an example, means that the imide group accounts for the imide group from tetracarboxylic dianhydride or its derivatives (that is, the above formula The ratio of the total amount of the repeating unit represented by (1-i)) to the carboxyl group (or its derivatives) (that is, the repeating unit represented by the above formula (1-a)). In polyimide, the imidization rate does not necessarily have to be 100%, and can be adjusted arbitrarily according to the application and purpose. The imidization rate of the specific polymer used in the present invention, that is, polyimide (A) (or polyimide (A')), is ideally 20-100% in view of reducing the incidence of display defects. , 50~99% is better, and 70~99% is even better.

The method of imidizing the polyimide precursor includes thermal imidization by directly heating the solution of the polyimide precursor or adding a catalyst to the solution of the polyimide precursor Imidization (also known as chemical imidization).

The temperature when the polyimide precursor is thermally imidized in the solution is usually 100~400°C, preferably 120~250°C. It is advisable to remove the water generated by the imidization reaction into the system It is better to do it outside.

The catalytic imidization of polyimide precursor is to add alkaline catalyst and acid anhydride to the solution of polyimide precursor, and usually stir at -20~250℃, preferably at 0~180℃ to proceed. The amount of alkaline catalyst is usually 0.5~30 mole times of amide acid group, preferably 2~20 mole times, and the amount of acid anhydride is usually 1~50 mole times of amide acid group, preferably 3~30 mole times. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine has a moderate alkalinity for the reaction to proceed, so it is preferable. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after the reaction becomes easy. The imidization rate obtained by using catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

When recovering the produced polyimide precursor or polyimide from the polyimide precursor or polyimide reaction solution, the reaction solution may be poured into a solvent and precipitated. Solvents used for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butylcytosol, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water and the like. The polymer deposited in the solvent and precipitated is collected by filtration and dried at normal temperature or under normal pressure or reduced pressure, or by heating. In addition, if the polymer recovered by precipitation is redissolved in an organic solvent and the operation of re-precipitation recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. The solvents at this time are, for example, alcohols, ketones, or hydrocarbons. If three or more solvents selected from these are used, the purification efficiency will be higher, so it is preferable.

The molecular weight of the polymer used in the present invention is 5,000 to 1,000,000 compared to the weight average molecular weight measured by GPC (Gel Permeation Chromatography) when considering the strength of the liquid crystal alignment film obtained therefrom, the workability of the film and the coating properties Ideally, more preferably 10,000~150,000.

＜Terminal modifier＞ When synthesizing the polymer (A) or polymer (A') of the present invention, the above-mentioned tetracarboxylic acid derivative component and diamine component can also be used, and an appropriate terminal modification agent can be used to synthesize a terminal-modified polymer . The end-modified polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained from the coating film and improving the adhesion between the sealant and the liquid crystal alignment film. In the present invention, the terminal of the polymer (A) or the polymer (A') is, for example, an amine group, a carboxyl group, an acid anhydride group, an isocyanate group, a thioisocyanate group or derivatives thereof. Amino groups, carboxyl groups, acid anhydride groups, isocyanate groups, and thioisocyanate groups can be obtained through common condensation reactions. The above-mentioned derivatives can be obtained by modifying their ends using the following terminal modifiers, for example.

二碳酸二第三丁酯、二碳酸二烯丙酯等二碳酸二酯化合物；丙烯醯氯、甲基丙烯醯氯、菸鹼醯氯等氯羰基化合物；苯胺、2-胺基苯酚、3-胺基苯酚、4-胺基水楊酸、5-胺基水楊酸、6-胺基水楊酸、2-胺基苯甲酸、3-胺基苯甲酸、4-胺基苯甲酸、環己胺、正丁胺、正戊胺、正己胺、正庚胺、正辛胺等單胺化合物；異氰酸乙酯、異氰酸苯酯、異氰酸萘酯等單異氰酸酯化合物；異硫氰酸乙酯、異硫氰酸烯丙酯等硫異氰酸酯化合物等。 End modifiers, such as acetic anhydride, maleic anhydride, nedylic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, the following formula ( Compounds represented by m-1)~(m-6), 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6, 7-Tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride and other anhydrides; [Chemical 34]

Di-tert-butyl dicarbonate, diallyl dicarbonate and other dicarbonate diester compounds; chlorocarbonyl compounds such as acryl chloride, methacryl chloride, nicotinyl chloride, etc.; aniline, 2-aminophenol, 3- Aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclo Monoamine compounds such as hexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, and naphthyl isocyanate; isothio Thioisocyanate compounds such as ethyl cyanate and allyl isothiocyanate, etc.

The usage ratio of the terminal modification agent is preferably 0.01-20 mole parts, more preferably 0.01-10 mole parts, relative to 100 mole parts in total of the diamine components used.

<Liquid Crystal Alignment Agent> One embodiment of the liquid crystal alignment agent of the present invention corresponds to at least one selected from the group consisting of the following (I) and (II). (I): Contains a polymer (A) and an epoxy compound (B) represented by formula (2). (II): Contains the reaction product [modified polymer (2mp)] of the polymer (A) and the epoxy compound (B). Moreover, one embodiment of the liquid crystal alignment agent of the present invention corresponds to at least one selected from the group consisting of the following (I') and (II'). (I'): Contains a polymer (A') and an epoxy compound (B') represented by formula (2'). (II'): Contains a reaction product [modified polymer (2mp')] of a polymer (A') and an epoxy compound (B'). In addition to the polymer (A), modified polymer (2mp), polymer (A'), or modified polymer (2mp'), the liquid crystal alignment agent of the present invention may further contain other polymers. The types of other polymers include polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene or its derivatives, poly(styrene-phenylmaleic acid) imine) derivatives, poly(meth)acrylates, etc.

The liquid crystal alignment agent is used for producing a liquid crystal alignment film, and takes the form of a coating liquid in consideration of forming a uniform thin film. The liquid crystal alignment agent of the present invention is preferably a coating liquid containing the above-mentioned polymer component and an organic solvent.

The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as the polymer component can be dissolved uniformly. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-ethyl Base-2-pyrrolidone, dimethylsulfene, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3- Methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl- 2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2 - pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (these are also collectively referred to as "good solvent") and the like. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethyl Propanamide or γ-butyrolactone is preferred. The content of the good solvent is preferably 20-99% by mass, more preferably 20-90% by mass, particularly preferably 30-80% by mass, of the entire solvent contained in the liquid crystal alignment agent.

In addition, the organic solvent contained in the liquid crystal alignment agent should be mixed with a solvent (also known as a poor solvent) that makes the coating of the liquid crystal alignment agent better and the surface smoothness of the coating film better than the above solvents. . Specific examples of poor solvents used together are as follows but not limited thereto.

For example: diisopropyl ether, diisobutyl ether, diisobutylmethanol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ether, Diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene diacetate Alcohol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisopentyl 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, butyl 3-methoxypropionate, n-butyl lactate, isopentyl 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-pentane Ketone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.

The ideal combination of good solvent and poor solvent, such as N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 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 and γ-butyrolactone and 4-Hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and 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 diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2 ,6-Dimethyl-4-heptanol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol di Methyl ether etc. The content of the poor solvent is preferably 1-80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10-80% by mass, and most preferably 20-70% by mass. The type and content of the poor solvent can be properly selected according to the coating device, coating conditions, and coating environment of the liquid crystal alignment agent.

In the liquid crystal alignment agent of this invention, you may contain additionally the component (it is also called an additive component hereafter) other than a polymer component, an epoxy compound, and an organic solvent. Such additive components include adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate, the 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.), used to adjust the dielectric constant of the liquid crystal alignment film, the dielectric body of the resistance, the conductive material, the imidization accelerator, etc.

R ₂及R ₃各自獨立地為氫原子、碳數1~3之烷基或「＊-CH ₂-OH」。＊表示原子鍵。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、及R’各自獨立地表示碳數1~5之烷基。上述芳香環之任意氫原子也可被鹵素原子、碳數1~10之烷基、碳數2~10之烯基、碳數1~10之氟烷基、或碳數2~10之氟烯基取代。 For the above-mentioned cross-linking compound, it may have two or more members selected from the group consisting of ethylene oxide group, propylene oxide group, protected isocyanate group, protected isocyanate group, and At least one of the group consisting of a thiocyanate group, a group containing an oxazoline ring structure, a group containing a Meldrum's acid structure, a cyclocarbonate group, and a group represented by the following formula (d) group, or a compound selected from compounds represented by the following formula (e). [chem 35]

R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbons, or "*-CH ₂ -OH". * Indicates an atomic bond. A represents a (m+n) valent organic group having an aromatic ring. m represents an integer from 1 to 6, and n represents an integer from 0 to 4. R, and R' each independently represent an alkyl group having 1 to 5 carbon atoms. Any hydrogen atom of the above-mentioned aromatic ring can also be replaced by a halogen atom, an alkyl group with 1 to 10 carbons, an alkenyl group with 2 to 10 carbons, a fluoroalkyl group with 1 to 10 carbons, or a fluoroalkene with 2 to 10 carbons base substitution.

Specific examples of compounds having two or more oxirane groups include compounds described in paragraph [0037] of JP-A-10-338880, and compounds having a three-ring structure described in International Publication No. 2017/170483. Compounds and other compounds having two or more oxirane groups. Among them, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N ,N,N',N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraepoxypropyl-p-phenylenediamine, the following Compounds containing nitrogen atoms such as compounds represented by formulas (r-1) to (r-3) may also be used.

[chem 36]

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

Specific examples of compounds having two or more protected isocyanate groups include compounds having two or more protected isocyanate groups described in paragraphs [0046] to [0047] of JP-A-2014-224978, International Publication No. 2015/ Compounds having three or more protected isocyanate groups described in paragraphs [0119] to [0120] of No. 141598 may also be compounds represented by the following formulas (bi-1) to (bi-3). [chem 37]

Specific examples of the compound having two or more protected isothiocyanate groups include compounds having two or more protected isothiocyanate groups described in JP-A-2016-200798.

Specific examples of compounds having two or more groups containing oxazoline ring structures include compounds containing two or more oxazoline structures described in paragraph [0115] of JP-A-2007-286597.

Specific examples of compounds having two or more groups containing Michaelis acid structures include compounds having two or more Michaelis acid structures described in International Publication No. 2012/091088.

Specific examples of the compound having two or more ring carbonate groups include compounds described in International Publication No. 2011/155577.

Examples of the alkyl group having 1 to 3 carbon atoms in R ₂ and R ₃ of the group represented by the above formula (d) include methyl, ethyl, propyl and the like.

Specific examples of compounds having two or more groups represented by the above formula (d) include those having two or more of the above formulas described in paragraph [0058] of International Publication No. 2015/072554 and Japanese Patent Application Laid-Open No. 2016-118753. Compounds represented by (d) and compounds described in JP-A-2016-200798 may be compounds represented by the following formulas (hd-1) to (hd-8). [chem 38]

The (m+n) valent organic group having an aromatic ring in A of the above formula (e) includes (m+n) aromatic hydrocarbon groups with 6 to 30 carbons, and aromatic hydrocarbon groups with 6 to 30 carbons connected directly or through an intermediary. (m+n) valent organic groups formed by radical bonds, and (m+n) valent groups with aromatic heterocycles. The above-mentioned aromatic hydrocarbons, for example, benzene, naphthalene and the like. Aromatic heterocycles include, for example, the structures exemplified by the above nitrogen-atom-containing heterocycles. The above-mentioned linking group includes -NR- (R represents a hydrogen atom or a monovalent organic group.), an alkylene group having 1 to 10 carbon atoms, or a group in which one hydrogen atom is removed from the above-mentioned alkylene group, a divalent organic group, and a divalent organic group. Or trivalent cyclohexane ring, etc. In addition, any hydrogen atom of the alkylene group mentioned above may be substituted by an alkyl group having 1 to 6 carbon atoms, a fluorine atom, or an organic group such as trifluoromethyl. Examples of the alkyl group of R in the above formula (e) include methyl, ethyl, propyl and the like. Specific examples include compounds described in International Publication No. 2010/074269 and compounds represented by the following formulas (e-1) to (e-10). [chem 39]

The above compound is an example of a crosslinkable compound and is not limited thereto. For example: ingredients other than the above disclosed on page 53 [0105] to page 55 [0116] of International Publication No. 2015/060357. Moreover, you may combine 2 or more types of crosslinkable compound.

In the liquid crystal alignment agent of the present invention, the content of the crosslinking 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 alignment agent, considering that the crosslinking reaction proceeds and exhibits good liquid crystal alignment. From a viewpoint, it is more preferably 1 to 15 parts by mass.

The above adhesion aids, such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane , 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl di Methoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethoxytriamine, 10-trimethoxy Silyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-di Azanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl- 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene )-3-aminopropyltrimethoxysilane, N-bis(oxyethylenyl)-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-Epoxycyclohexyl)ethyltrimethoxysilane, 3-Glycidoxypropylmethyldimethoxysilane, 3-Glycidoxypropyltrimethoxysilane, 3- Glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethylsilane Dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyl Triethoxysilane, 3-acryloxypropyltrimethoxysilane, ginseng (trimethoxysilylpropyl) isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3- Silane coupling agents such as mercaptopropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane. When a silane coupling agent is used, it is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, based on 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, in consideration of exhibiting good liquid crystal alignment.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of the components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) can be appropriately selected in consideration of viscosity, volatility, etc., preferably 0.5 to 15 mass %, more preferably in the range of 1 to 10% by mass. The particularly desirable range of solid content concentration varies depending on the method used when coating the liquid crystal alignment agent on the substrate. For example, when using the spin coating method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by mass. When using the printing method, the solid content concentration is in the range of 3 to 9% by mass, so the solution viscosity is preferably in the range of 12 to 50 mPa·s. When using the inkjet method, the solid content concentration is in the range of 1 to 5% by mass, so the solution viscosity is preferably in the range of 3 to 15 mPa·s.

<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 a horizontal alignment type or a vertical alignment type (VA type) liquid crystal alignment film, and it is a liquid crystal alignment film suitable for a horizontal alignment type liquid crystal display element such as an IPS method or an FFS method. The liquid crystal display element of the present invention includes the above-mentioned liquid crystal alignment film. The liquid crystal display device of the present invention, for example, can be manufactured according to the following steps (1) to (3).

(1) The step of coating the liquid crystal alignment agent on the substrate The liquid crystal alignment agent of the present invention is coated on one side of the substrate provided with the patterned transparent conductive film by appropriate coating methods such as roll coating method, spin coating method, printing method, and inkjet method. Here, the substrate is not particularly limited as long as it is highly transparent, and a plastic substrate such as a glass substrate, a silicon nitride substrate, an acrylic substrate, or a polycarbonate substrate may be used together. In addition, if the reflective liquid crystal display element has only one side substrate, opaque objects such as silicon wafers can also be used, and the electrodes at this time can also use materials that reflect light such as aluminum. Also, when manufacturing IPS-type or FFS-type liquid crystal display elements, a substrate provided with electrodes made of a comb-shaped transparent conductive film or metal film and an opposite substrate without electrodes are used.

(2) The step of calcining the coating film After coating the liquid crystal alignment agent, in order to prevent dripping of the applied alignment agent, it is preferable to carry out preliminary heating (pre-baking). The pre-baking temperature is preferably 30-200°C, more preferably 40-150°C, and most preferably 40-100°C. The pre-baking time is preferably 0.25-10 minutes, more preferably 0.5-5 minutes. It is preferred to perform a heating (post-bake) step. The post-baking temperature is preferably 80-300°C, more preferably 120-250°C. The post-baking time is preferably from 5 to 200 minutes, more preferably from 10 to 100 minutes. The film thickness of the film formed in this way is preferably 5-300 nm, more preferably 10-200 nm.

The coating film formed in the above step (2) can be directly used as a liquid crystal alignment film, but the coating film can also be subjected to an alignment ability imparting treatment. Alignment treatment, for example, rubbing the coating film in a certain direction with a roller wrapped with a cloth made of fibers such as nylon, nylon, cotton, etc., and photo-alignment treatment of irradiating polarized or non-polarized radiation to the coating film Wait.

In the photo-alignment treatment, for the radiation irradiated to the coating film, for example, ultraviolet rays and visible rays including light with a wavelength of 150 to 800 nm can be used. When the radiation is polarized, it may be linearly polarized or partially polarized. Also, when the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or may be combined. When irradiating non-polarized radiation, the direction of irradiation is oblique.

(3) Steps of making liquid crystal cells Two substrates on which a liquid crystal alignment film was formed as described above were prepared, and liquid crystals were arranged between the two substrates facing each other. Specifically, the following two methods are mentioned. In the first method, first, two substrates are arranged facing each other with a gap (cell gap) in such a manner that the respective liquid crystal alignment films face each other. Then, the peripheral parts of the two substrates were bonded together using a sealant, and the liquid crystal composition was injected into the cell gap partitioned by the substrate surface and the sealant to contact the film surface, and then the injection hole was sealed.

Also, the second method is a method called ODF (One Drop Fill) method. On one of the two substrates on which the liquid crystal alignment film has been formed, apply, for example, a UV-curable sealant on predetermined positions, and then drop liquid crystal composition on several predetermined positions on the surface of the liquid crystal alignment film. Then, with the liquid crystal alignment film facing the other substrate, the liquid crystal composition is pushed out on the entire surface of the substrate to make it contact with the film surface. Then, the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant. When using either method, it is more heated until the liquid crystal composition used becomes the temperature of the isotropic phase, and then slowly cooled to room temperature to remove the flow alignment when filling the liquid crystal is ideal. The above-mentioned liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. Hereinafter, a liquid crystal composition having a positive dielectric anisotropy is also referred to as a positive type liquid crystal, and a liquid crystal composition having a negative dielectric anisotropy is also referred to as a negative type liquid crystal.

The above-mentioned liquid crystal composition may also contain fluorine atoms, hydroxyl groups, amino groups, groups containing fluorine atoms (for example: trifluoromethyl), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, isothiocyanate groups , heterocycle, cycloalkane, cycloalkene, steroid skeleton, benzene ring, or liquid crystal compound of naphthalene ring, and may also contain compounds having two or more rigid sites (mesogen skeleton) exhibiting liquid crystallinity in the molecule (for example: rigid Two biphenyl structures, or terphenyl structures linked by an alkyl group to form a double mesogen compound). The liquid crystal composition may also be a liquid crystal composition in a nematic phase, a liquid crystal composition in a smectic phase, or a liquid crystal composition in a cholesteric phase. In addition, the above-mentioned liquid crystal composition may further contain additives from the viewpoint of improving the alignment of liquid crystals. Examples of such additives include: photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (for example: S-811 manufactured by Merck Co., Ltd.); antioxidants; ultraviolet absorbers; pigments ; Defoamer; Polymerization initiator; Or polymerization inhibitor, etc. Examples of positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, and MLC-7081 manufactured by Merck & Co., Ltd. Negative type liquid crystal, for example, MLC-6608, MLC-6609, MLC-6610, or MLC-7026-100 manufactured by Merck & Co., Ltd. Moreover, as a liquid crystal containing the compound which has a polymeric group, MLC-3023 by Merck & Co. is mentioned.

In addition, when rubbing the coating film, two substrates are arranged facing each other so that the rubbing directions of the respective coating films form a predetermined angle, for example, perpendicularly or antiparallel. As the sealing agent, for example, an epoxy resin containing alumina balls as a hardener and a spacer can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred.

Furthermore, a liquid crystal display element can be obtained by affixing a polarizing plate to the outer surface of the liquid crystal cell as needed. The polarizing plate attached to the outer surface of the liquid crystal cell can be exemplified: a polarizing film made of a polarizing film called "H film" obtained by sandwiching a cellulose acetate protective film while stretching and aligning polyvinyl alcohol while absorbing iodine. Polarizing plate composed of plate or H film itself.

The comb-teeth electrode substrate used in IPS (In-Plane Switching) mode, that is, the IPS substrate, has: a base material; a plurality of linear electrodes formed on the base material and arranged in a comb-like shape; and coated wire-shaped electrodes on the base material Liquid crystal alignment film formed by electrodes. In addition, the comb electrode substrate used in the FFS (Frindge Field Switching) mode, that is, the FFS substrate, has: a substrate; a surface electrode formed on the substrate; an insulating film formed on the surface electrode; formed on the insulating film and configured as a plurality of comb-shaped linear electrodes; and a liquid crystal alignment film formed on the insulating film to cover the linear electrodes.

Fig. 1 is a schematic cross-sectional view showing an example of a transverse electric field liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element. In the transverse electric field liquid crystal display element 1 illustrated in FIG. 1 , a liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 provided with a liquid crystal alignment film 2c and an opposing substrate 4 provided with a liquid crystal alignment film 4a. The comb electrode substrate 2 has: a substrate 2a; a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-like shape; a liquid crystal alignment film formed on the substrate 2a to cover the linear electrodes 2b 2c. The opposite 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 transverse electric field liquid crystal display element 1 , when a voltage is applied to the linear electrodes 2 b , an electric field is generated between the linear electrodes 2 b as shown by lines of electric force L .

Fig. 2 is a schematic sectional view showing another example of a transverse electric field liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element. In the transverse electric field liquid crystal display element 1 illustrated in FIG. 2 , a liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 provided with a liquid crystal alignment film 2 h and an opposing substrate 4 provided with a liquid crystal alignment film 4 a. The comb electrode substrate 2 has: a substrate 2d; a surface electrode 2e formed on the substrate 2d; an insulating film 2f formed on the surface electrode 2e; a plurality of wires formed on the insulating film 2f and arranged in a comb shape and a liquid crystal alignment film 2h formed on the insulating film 2f to cover the linear electrode 2g. The opposite 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 transverse electric field liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the line electrode 2g, an electric field is generated between the surface electrode 2e and the line electrode 2g as indicated by lines of force L.

The liquid crystal alignment film of the present invention, in addition to the above-mentioned liquid crystal alignment film, can be applied to various purposes, for example, it can be used as a liquid crystal alignment film for a retardation film, a scanning antenna, a liquid crystal alignment film for a liquid crystal array antenna, or a transmission scattering type. Used in liquid crystal alignment film for liquid crystal dimming components. Furthermore, it can also be used for purposes other than liquid crystal alignment films, such as protective films (eg, protective films for color filters), spacer films, interlayer insulating films, antireflective films, wiring coating films, and antistatic films. , Motor insulation film (gate insulation film for flexible displays).

The liquid crystal display device of the present invention can be effectively used in various devices, such as clocks, portable game machines, word processors, notebook personal computers, navigation systems, video cameras, PDAs, digital cameras, mobile phones, smart phones, various Various display devices such as monitors, LCD TVs, and information displays. [Example]

The following examples are given to describe the present invention in more detail, but the present invention is not limited thereto. The abbreviations of the compounds used and the measurement methods of the respective physical properties are as follows.

(Organic solvent) NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: Butylated cellulosulfone BCA: Butylcellothreoacetate (acid dianhydride) CA-1~CA-4 : Each is a compound (diamine) represented by the following formula (CA-1)~(CA-4) DA-1~DA-5: Each is a compound represented by the following formula (DA-1)~(DA-5) ( End modification agent) Boc ₂ O: di-tert-butyl dicarbonate (epoxy compound) EP-1~EP-3: each compound (additive) C represented by the following formula (EP-1)~(EP-3) -1: Compound S-1 represented by the following formula (C-1): 3-glycidoxypropyltriethoxysilane [Chem. 40]

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

<Measurement of imidization rate> Put 20 mg of polyimide powder into an NMR sample tube (NMR standard sampling tube, φ5 (manufactured by Kusano Science Co., Ltd.)), add deuterated dimethyl oxide ([D ₆ ]- DMSO, 0.05% tetramethylsilane (TMS) mixture) 1.0mL, apply ultrasonic waves to dissolve completely. Proton NMR at 500 MHz was measured on this solution with a Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) "AVANCE III" (manufactured by BRUKER). (Chemical) imidization rate is determined by using the proton from the structure that does not change before and after imidization as the reference proton, using the peak cumulative value of this proton and the amino acid that appears around 9.5~10.0ppm The cumulative value of the proton peak of the NH group can be calculated according to the following formula. In addition, in the following formula, x represents the cumulative value of proton peaks derived from the NH group of amide acid, y represents the cumulative peak value of reference protons, and α represents polyamic acid (imidization ratio is 0%), The ratio of the number of standard protons to one proton of the NH group of amide. Imidization rate (%)＝(1-α・x/y)×100

[Synthesis of Polymer] <Synthesis Example 1> In a 200mL four-necked flask with a stirring device and a nitrogen inlet tube, add DA-1 (8.04g, 40.2mmol), DA-2 (4.36g, 10.9mmol), DA-3 (12.2 g, 21.9 mmol) and NMP (98.4 g) were stirred and dissolved at room temperature while feeding nitrogen gas. Then, CA-1 (9.40 g, 47.4 mmol) and NMP (37.6 g) were added under ice-cooling, and it stirred at 50 degreeC for 2 hours. After cooling to room temperature, add CA-2 (4.65g, 23.7mmol) and NMP (18.6g), and stir at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-1) with a concentration of 20% by mass (viscosity: 1320mPa・s). Measure the obtained solution (100 g) of the polyamic acid (PAA-1) in a 200 mL Erlenmeyer flask equipped with a stirring bar, add Boc ₂ O (1.24 g, 5.68 mmol), and stir at 40°C for 15 hours to obtain A solution of terminally modified polyamic acid. In a 200mL four-necked flask with a stirring device and a nitrogen inlet tube, measure the obtained solution (100g) of the above-mentioned end-modified polyamic acid, add NMP (66.7g), acetic anhydride (14.2g) and pyridine ( 4.70 g), stirred at room temperature for 30 minutes, and then reacted at 60° C. for 4 hours. This reaction solution was poured into methanol (650 g), and the obtained precipitate was separated and filtered. The precipitate was washed with methanol, and dried under reduced pressure at 80° C. to obtain a polyimide (SPI-1) powder. The imidization rate of this polyimide powder was 90%. NMP (70.4 g) was added to the obtained polyimide powder (9.60 g), stirred and dissolved at 70° C. for 24 hours, and a solution of polyimide (SPI-1) was obtained.

<Synthesis Example 2> DA-4 (1.99g, 10.00mmol), DA-5 (1.98g, 10.0mmol) and NMP (29.2g) were added to a 50mL four-necked flask with a stirring device and a nitrogen inlet tube, and nitrogen gas was fed into the flask. Stir at room temperature to dissolve. CA-3 (2.50 g, 10.0 mmol) and NMP (7.55 g) were added to this diamine solution, and it stirred at 50 degreeC for 2 hours. Then add CA-4 (2.71g, 9.20mmol) and NMP (14.8g) under ice-cooling, and stir at 50°C for 6 hours to obtain a solution of polyamic acid (PAA-2) with a concentration of 15% (viscosity: 532mPa・s).

[Synthesis of Modified Polymer] ＜Synthesis Example 3＞ Measure the solution (30.0 g) of the polyamic acid (PAA-2) obtained in Synthesis Example 2 in a 50 mL eggplant-shaped flask with a stirring device and a nitrogen inlet tube, add EP-1 (0.44 g, 5.87 mmol, relative 1 mol part of the amide acid part of the polyamic acid (PAA-2) is 0.3 mol part), and stirred at 70°C for 18 hours to obtain a solution of the modified polyamic acid (PAA-2-1).

＜Synthesis Examples 4~10＞ The kind, the addition and the stirring time of the epoxy compound of the reaction are changed as shown in Table 1, and in addition, the same operation is carried out with Synthetic Example 3 to obtain modified polyamic acid (PAA-2-2) ~ ( PAA-2-8) solution.

[Table 1] polymer Types of epoxy compounds Addition amount (mol parts) Stirring time (hours) Synthesis example 3 PAA-2-1 EP-1 0.3 18 Synthesis Example 4 PAA-2-2 EP-1 0.5 18 Synthesis Example 5 PAA-2-3 EP-1 0.5 48 Synthesis Example 6 PAA-2-4 EP-1 0.7 18 Synthesis Example 7 PAA-2-5 EP-1 1.0 18 Synthesis Example 8 PAA-2-6 EP-1 1.0 48 Synthesis Example 9 PAA-2-7 EP-2 1.0 18 Synthesis Example 10 PAA-2-8 EP-3 1.0 18

[Preparation of liquid crystal alignment agent] <Example 1> Using the solution of polyimide (SPI-1) obtained in Synthesis Example 1 and the solution of modified polyamide acid (PAA-2-1) obtained in Synthesis Example 3, dilute with NMP, GBL, BCS and BCA, Add the additive (C-1) so that it becomes 3 parts by mass with respect to the total amount of 100 parts by mass of all the polymers, and stir at room temperature for 2 hours to obtain the component ratio of the polymer as (SPI-1):(PAA-2 -1) = 30:70 (mass ratio in terms of solid content), the polymer solid content concentration is 4% by mass, and the solvent composition ratio is NMP:GBL:BCS:BCA=30:46:15:5 (mass ratio) liquid crystal Alignment agent (1). Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Examples 2 to 9, Comparative Example 1> As shown in Table 2 below, except for changing the polymers and additives used, the same operations as in Example 1 were performed to obtain liquid crystal alignment agents (2)-(9) and (R1).

<Example 10> Use the solution of polyimide (SPI-1) obtained in Synthesis Example 1 and the solution of polyamic acid (PAA-2) obtained in Synthesis Example 2, dilute with NMP, GBL, BCS and BCA, and add epoxy compound (EP-1) and additive (C-1) were made into 5 parts by mass and 3 parts by mass with respect to the total amount of 100 parts by mass of all polymers, respectively, and stirred at room temperature for 2 hours, and the component ratio of the obtained polymer was ( SPI-1): (PAA-2) = 30:70 (mass ratio in terms of solid content), the polymer solid content concentration is 4% by mass, and the solvent composition ratio is NMP:GBL:BCS:BCA=30:46:15: 5 (mass ratio) liquid crystal alignment agent (10). Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

＜Example 11~13＞ As shown in Table 2 below, except for changing the types and amounts of the additives used, the same operation was performed as in Example 10 to obtain liquid crystal alignment agents (11)-(13).

<Example 14> Using the solution of polyamic acid (PAA-2) obtained in Synthesis Example 2, dilute it with NMP, GBL, BCS, and BCA, and add epoxy compound (EP-3) so that it becomes 15 parts by mass relative to 100 parts by mass of the entire polymer portion, stirred at room temperature for 2 hours. Then, the obtained solution was filtered through a filter with a pore size of 0.5 μm to obtain a solvent composition ratio of NMP:GBL:BCS:BCA=30:46:15:5 (mass ratio), and a polymer solid content concentration of 4% by mass. Liquid crystal alignment agent (14) (Table 2 below). Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

＜Comparative examples 2~4＞ As shown in Table 2 below, except for changing the polymers and additives used, the same implementation as in Example 14 was carried out to obtain liquid crystal alignment agents (R2)-(R4).

[Table 2] Liquid crystal alignment agent polymer Additives (parts by mass) Amount of epoxy compound ingredient 1 ingredient 2 EP-1 EP-2 EP-3 C-1 S-1 parts by mass* parts by mass** Mole parts Example 1 (1) SPI-1 PAA-2-1 - - - 3 - 7 - - Example 2 (2) SPI-1 PAA-2-2 - - - 3 - 11 - - Example 3 (3) SPI-1 PAA-2-3 - - - 3 - 11 - - Example 4 (4) SPI-1 PAA-2-4 - - - 3 - 15 - - Example 5 (5) SPI-1 PAA-2-5 - - - 3 - twenty two - - Example 6 (6) SPI-1 PAA-2-5 - - - 3 1 twenty two - - Example 7 (7) SPI-1 PAA-2-6 - - - 3 - twenty two - - Example 8 (8) SPI-1 PAA-2-7 - - - 3 - 17 - - Example 9 (9) SPI-1 PAA-2-8 - - - 3 - - 45 0.96 Example 10 (10) SPI-1 PAA-2 5 - - 3 - 5 - - Example 11 (11) SPI-1 PAA-2 10 - - 3 - 10 - - Example 12 (12) SPI-1 PAA-2 15 - - 3 - 15 - - Example 13 (13) SPI-1 PAA-2 10 - - 3 1 10 - - Example 14 (14) PAA-2 - - - 15 - - - 15 0.24 Comparative example 1 (R1) SPI-1 PAA-2 - - - - - - - - Comparative example 2 (R2) SPI-1 - - - - - - - - - Comparative example 3 (R3) PAA-2 - - - - - - - - - Comparative example 4 (R4) SPI-1 - - - 15 - - - 15 2.6※

In Table 2, the amount (parts by mass ^* ) of the epoxy compound represents the amount of the epoxy compound (B) relative to the total of 100 parts by mass of the polymer (A) and other polymers. In Table 2, the amount of the epoxy compound (parts by mass ^** ) represents the amount of the epoxy compound (B') relative to the total of 100 parts by mass of the polymer (A') and other polymers. In Table 2, the amount (parts of mole) of the epoxy compound represents the amount of the epoxy compound relative to 1 mole part of the amide acid group of the polymer (A'). * in Comparative Example 4 represents the amount (parts in moles) of the epoxy compound relative to 1 mole part of the amide acid group possessed by the polymer (SPI-1).

[Production of FFS-driven liquid crystal cells] Fabrication of liquid crystal cells with the configuration of fringe field switching (Fringe Field Switching: FFS) mode liquid crystal display elements. First prepare the substrate with electrodes. The substrate is a glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. Form an ITO electrode with a full-surface pattern on the substrate as the counter electrode of the first layer, and form a film by CVD (chemical vapor deposition) method as the second layer on the counter electrode of the first layer SiN (silicon nitride) film. The SiN film of the second layer has a thickness of 500nm and functions as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning the ITO film as the third layer is arranged, and two pixels of the first pixel and the second pixel are formed, each pixel The size is 10mm in length and 5mm 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 on the third layer, the central part is bent at an inner angle of 160°, and the electrode elements with a width of 3 μm are spaced in parallel at intervals of 6 μm. It has a comb-tooth shape arranged in many places, and one pixel is used to connect multiple electrode elements. The line of the Ministry is the boundary, with the first and second districts. Comparing the first area and the second area of each pixel, the formation directions of the electrode elements constituting the pixel electrodes are different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as the reference, the first region of the pixel is formed in such a way that the electrode elements of the pixel electrode are at an angle (clockwise) of +10°, and the second region of the pixel is formed It is formed so that the electrode elements of the pixel electrodes form an angle of -10° (counterclockwise). That is, in the first area and the second area of each pixel, the direction of the rotation of the liquid crystal in the substrate surface (in-plane switching) caused by the voltage application between the pixel electrode and the counter electrode, The system is formed in such a way that they become opposite directions of each other. Then filter the liquid crystal alignment agent obtained above with a filter with a pore size of 1.0 μm, and then coat the prepared substrate with electrodes and the glass with a columnar spacer with a height of 4 μm on the back of which the ITO film has been formed by spin coating. substrate. Then, it was dried on a hot plate at 80° C. for 5 minutes, and then calcined in a hot air circulation oven at 230° C. for 20 minutes to obtain a polyimide film with a film thickness of 60 nm. This polyimide film was rubbed with a yarn cloth (YA-20R manufactured by Yoshikawa Chemical Co., Ltd.) (roll diameter: 120 mm, roll rotation speed: 1000 rpm, moving speed: 30 mm/sec, pushing length: 0.3 mm, rubbing direction: opposite After the IZO comb-teeth electrodes on the third layer are inclined at 10°, irradiate with ultrasonic wave in pure water for 1 minute and wash, and blow air to remove water droplets. Then, it was dried at 80° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. The obtained 2 substrates with liquid crystal alignment film were used as a group, and a sealant (XN-1500T manufactured by Mitsui Chemicals Co., Ltd.) was printed on the substrate in the form of retaining the liquid crystal injection port, and the other substrate was connected with the liquid crystal alignment film surface. Facing, the rubbing direction becomes antiparallel to fit. Afterwards, heat treatment was carried out at 150°C for 60 minutes to harden the sealant and produce void cells with a cell gap of 4 μm. Negative-type liquid crystal MLC-7026 (manufactured by Merck & Co.) was injected into this ghost cell by a reduced-pressure injection method, and the injection port was sealed to obtain a liquid crystal cell of the FFS method. Afterwards, the obtained liquid crystal cells were heated at 120° C. for 1 hour, and left overnight at 23° C. for evaluation.

[Evaluation of DC accumulated charge] The FFS-driven liquid crystal cell produced above is placed between two polarizers arranged in such a way that the polarization axes are perpendicular to each other. In the state where the pixel electrode and the counter electrode are short-circuited and have the same potential, the two polarizers are connected to each other. The LED backlight is irradiated under, and the angle of the liquid crystal cell is adjusted so that the brightness of the transmitted light of the LED backlight measured on the two polarizing plates becomes the minimum. Then, while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, measure the V-T curve (voltage-transmittance curve), calculate the AC voltage at which the relative transmittance becomes 23% or 100%, and define it as the driving voltage. In the evaluation of the accumulated charge, an AC drive with a relative transmittance of 100% is applied for 45 minutes, and the minimum offset voltage value is measured every 3 minutes during this period, and the change from the start of the measurement to 45 minutes later is calculated at the same time, defined as DC accumulated charge. The accumulated charge will cause the disorder of liquid crystal alignment, affect the display in the form of afterimage, and significantly reduce the display quality of the liquid crystal display element. Therefore, the smaller the amount of DC accumulated charge generated during driving, the better it can be said. In the present invention, the accumulated charge amount of the liquid crystal alignment agent that has not been subjected to epoxy modification treatment or epoxy compound addition is normalized to 100% for evaluation. Specifically, Examples 1 to 13 are the values when the accumulated charge of Comparative Example 1 is 100%, Example 14 is the value when the accumulated charge of Comparative Example 3 is 100%, and Comparative Example 4 is the value of Comparative Example 2 The value when the accumulated charge amount is 100% is evaluated. The smaller the value, the better. In addition, the evaluation of the amount of DC accumulated charge according to the above-mentioned method was carried out under the temperature condition of the state where the temperature of the liquid crystal cell was 23°C.

[Measurement of relaxation speed of accumulated charge] The FFS-driven liquid crystal cell produced above is placed between two polarizers arranged in such a way that the polarization axes are perpendicular to each other. In the state where the pixel electrode and the counter electrode are short-circuited and have the same potential, the two polarizers are connected to each other. The LED backlight is irradiated under, and the angle of the liquid crystal cell is adjusted so that the brightness of the transmitted light of the LED backlight measured on the two polarizing plates becomes the minimum. Then, measure the V-T curve (voltage-transmittance curve) while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, calculate the AC voltage at which the relative transmittance becomes 23% or 100%, and define it as the driving voltage. Image sticking was evaluated by applying an AC voltage with a frequency of 30 Hz at a relative transmittance of 23% to drive the liquid crystal cell, and at the same time applying a DC voltage of 1 V and driving it for 45 minutes. Thereafter, only the application of the DC voltage was stopped, and the drive was further performed for 15 minutes only with the AC voltage. When 10 minutes have elapsed since the application of the DC voltage was stopped, when the relative transmittance eased to 25% or less, it was defined as "0", and when it took more than 10 minutes for the relative transmittance to drop to 25% or less, it was defined as "×" ". In addition, image sticking evaluation by the above-mentioned method was carried out under the temperature condition of the state where the temperature of the liquid crystal cell was 23°C.

[Evaluation of afterimage due to long-term AC drive] The evaluation of residual image due to long-term AC driving in this evaluation is to evaluate the residual image (also known as AC residual image) caused by the reduction of the alignment performance of the liquid crystal alignment film, which is different from the above-mentioned residual image caused by the accumulated charge (also known as for DC afterimage). For the difference between AC afterimage and DC afterimage, for example: disclosed in [0037] of Japanese Patent Application Laid-Open No. 2016-106281. Using the FFS produced above to drive the liquid crystal cell, apply an AC voltage with a frequency of 60 Hz and ±5 V for 120 hours in a constant temperature environment of 60°C. Thereafter, the liquid crystal cell was left at room temperature for one day in a state where the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited. After placing the liquid crystal cell between two polarizers arranged so that the polarization axes are perpendicular to each other, turn on the backlight in a state where no voltage is applied, and adjust the arrangement angle of the liquid crystal cell to minimize the brightness of the transmitted light. Then, the rotation angle for rotating the liquid crystal cell from the angle at which the second region of the first pixel becomes darkest to the angle at which the first region becomes darkest is calculated as an angle Δ. Similarly, the second pixel compares the second area with the first area, and calculates the same angle Δ. For the afterimage characteristics due to long-term AC drive, the smaller the value of the angle Δ, the better. When the value of this angle Δ is less than 0.3°, it is rated as "〇", when it is more than 0.3° and less than 0.6°, it is rated as "△", and when it is more than 0.6°, it is rated as "×".

[Evaluation of flicker caused by driving] The FFS driving liquid crystal cell produced above was placed between two polarizers arranged so that the polarization axes were perpendicular to each other, and the LED backlight (light source: LED, luminosity : 20000cd/m ² ) Turn on the light, and adjust the arrangement angle of the liquid crystal cells so that the brightness of the transmitted light becomes the minimum. Then, while applying an AC voltage with a frequency of 30 Hz to the liquid crystal cell, measure the VT curve (voltage-transmittance curve), calculate the AC voltage at which the relative transmittance becomes 23%, and define it as the driving voltage. The measurement of flicker is to temporarily turn off the LED backlight that has already been lit, and after 72 hours of shading, the LED backlight is turned on again. At the same time as the backlight is turned on, an AC voltage of 30 Hz with a relative transmittance of 23% is applied. The liquid crystal cell was driven for 30 minutes, and the flicker amplitude was tracked. For the flicker amplitude, a data collection/data collection switch unit 34970A (manufactured by Agilent Technologies) connected via a photodiode and an IV conversion amplifier is used to read the transmitted light of the LED backlight passing through the two polarizers and the liquid crystal cell between them. Based on this data, the value calculated using the following formula is defined as the flicker level. Flicker level (%)={flicker amplitude/(2×z)}×100 In the above formula, z is the AC voltage at a frequency of 30 Hz read by the data collection/data collection switch unit 34970A at a frequency of 23% relative transmittance The brightness value when driving. The evaluation of flicker is defined as "〇" when the flicker level remains below 1.5% from the time when the LED backlight is turned on and the application of the AC voltage is started until 30 minutes have elapsed, and the flicker level reaches 1.5% after 30 minutes The definition above is rated as "×". The evaluation of flicker level according to the above method was carried out under the condition that the temperature of the liquid crystal cell was 23°C.

[Manufacturing of liquid crystal cells for evaluation of pretilt angle and voltage retention] First prepare the substrate with electrodes. The substrate is a glass substrate with a size of 30mm×40mm and a thickness of 0.7mm. An ITO electrode with a film thickness of 35nm has been formed on the substrate, and the electrode is a strip pattern with a length of 40mm and a width of 10mm. Then, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm, and then coated on the prepared substrate with electrodes by spin coating. After drying on a hot plate at 80°C for 2 minutes, it was calcined in an infrared heating furnace at 230°C for 20 minutes to form a coating film with a thickness of 60nm and obtain a substrate with a liquid crystal alignment film. After rubbing this liquid crystal alignment film with a rayon cloth (YA-20R manufactured by Yoshikawa Chemical Industry Co., Ltd.) (roller diameter: 120mm, roll speed: 1000rpm, moving speed: 20mm/sec, push-in length: 0.4mm), carry out in pure water Ultrasonic irradiation for 1 minute and cleaning. After removing water droplets by blowing air, dry at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Prepare 2 substrates with a liquid crystal alignment film, spread a 4 μm spacer on one of the liquid crystal alignment film surfaces, print a sealant (XN-1500T manufactured by Mitsui Chemicals Co., Ltd.) on it, and attach the other substrate so that The rubbing direction is opposite and the film surfaces face each other, and then heat treatment at 150°C for 60 minutes to harden the sealant and form hollow cells. Negative liquid crystal MLC-7026 (manufactured by Merck & Co.) was injected into this ghost cell by a reduced-pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. After that, the obtained liquid crystal cells were heated at 120° C. for 1 hour, left overnight at 23° C., and then used for each evaluation.

[Measurement of pretilt angle] The pretilt angle in the above-mentioned liquid crystal cell was measured using an AxoScan Mueller Matrix Polarimeter manufactured by OPTOMETRICS. The lower the value of the pretilt angle, the better. When the pretilt angle was 2.0° or less, it was rated as "o", and when it exceeded 2.0°, it was rated as "x".

[Evaluation of voltage retention rate after backlight resistance test] The above-mentioned liquid crystal cell was left under a high-brightness backlight (20000 cd/m ² ) at a surface temperature of 50°C for 120 hours. After standing, apply a voltage of 1V to the liquid crystal cell at a temperature of 60°C for 60μsec, measure the voltage after 16.7msec, and calculate how much the voltage can be maintained, which is defined as the voltage retention rate. It was defined as the voltage retention rate after the backlight resistance test. When the voltage retention rate after the backlight resistance test is 95% or more, it is rated as "◎", when it is less than 95% and more than 85%, it is rated as "〇", and when it is less than 85% and more than 75%, it is rated as "△". When it is less than 75%, it is rated as "×".

[result] For the liquid crystal display elements using the liquid crystal alignment agents of the above-mentioned Examples 1-14 and Comparative Examples 1-4, evaluate the DC accumulated charge amount, the relaxation speed of the accumulated charge, the afterimage due to long-term AC driving, and the driving The evaluation results of voltage retention after flicker, pretilt angle, and backlight resistance test are shown in Table 3 below.

[table 3] Liquid crystal alignment agent DC accumulated charge (%) Relaxation speed of accumulated charge Afterimage characteristics due to long-term AC drive Flicker caused by the drive Pretilt voltage retention Example 1 (1) 85 〇 〇 〇 〇 〇 Example 2 (2) 50 〇 〇 〇 〇 〇 Example 3 (3) 20 〇 △ 〇 〇 〇 Example 4 (4) 35 〇 △ 〇 〇 〇 Example 5 (5) 15 〇 △ 〇 〇 〇 Example 6 (6) 15 〇 △ 〇 〇 〇 Example 7 (7) 5 〇 〇 〇 〇 ◎ Example 8 (8) 35 〇 〇 〇 〇 〇 Example 9 (9) 30 〇 〇 〇 〇 〇 Example 10 (10) 95 〇 〇 〇 〇 〇 Example 11 (11) 90 〇 〇 〇 〇 〇 Example 12 (12) 80 〇 〇 〇 〇 〇 Example 13 (13) 90 〇 〇 〇 〇 〇 Example 14 (14) 75 〇 no data 〇 〇 〇 Comparative example 1 (R1) 100 〇 〇 x 〇 〇 Comparative example 2 (R2) 100 x 〇 no data 〇 △ Comparative example 3 (R3) 100 〇 x x 〇 〇 Comparative example 4 (R4) 206 〇 〇 〇 〇 △

1: Transverse electric field liquid crystal display element 2: Comb electrode substrate 2a: Substrate 2b: Wire electrode 2c: Liquid crystal alignment film 2d: Substrate 2e: surface electrode 2f: insulating film 2g: wire electrode 2h: Liquid crystal alignment film 3: LCD 4: Facing the substrate 4a: Liquid crystal alignment film 4b: Substrate L: power line

Fig. 1 shows a schematic cross-sectional view of an example of a transverse electric field liquid crystal display element of the present invention. Fig. 2 shows a schematic cross-sectional view of another example of the transverse electric field liquid crystal display element of the present invention.

1: Transverse electric field liquid crystal display element

2: Comb electrode substrate

2a: Substrate

2b: Wire electrode

2c: Liquid crystal alignment film

3: LCD

4: Facing the substrate

4a: Liquid crystal alignment film

4b: Substrate

L: power line

Claims (12)

A liquid crystal alignment agent, characterized by: at least one selected from the group consisting of the following (I) and (II), (I): containing a repeating unit represented by the following formula (1-a) And the polymer (A) of the repeating unit in the group formed by the repeating unit represented by the following formula (1-i), and the epoxy compound (B) represented by the following formula (2); (II): containing the polymer (A) reaction product with the epoxy compound (B);

In formula (1-a) and formula (1-i), X ₁ represents a tetravalent organic group, Y ₁ represents a divalent organic group, and two R ₁ and Z ₁ each independently represent a hydrogen atom with a carbon number of 1 to 6 Alkyl, alkenyl with 2~6 carbons, alkynyl with 2~6 carbons, tert-butoxycarbonyl, 9-fenylmethoxycarbonyl, alkylsilyl with 1~6 carbons, or A monovalent organic group in which at least one of the hydrogen atoms possessed by the alkyl group, the alkenyl group or the alkynyl group is replaced by a halogen atom or a nitro group, R ₁ and Z ₁ may be the same or different,

In formula (2), R ₁ ~ R ₄ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkenyl group with 2 to 5 carbon atoms. ~5 alkynyl groups, or a monovalent organic group obtained by substituting at least one of the hydrogen atoms of the alkyl group, the alkenyl group or the alkynyl group with a hydroxyl group, a halogen atom, a nitro group, or a cyano group, except that R ₁ ~ At least one of R ₄ represents a group other than a hydrogen atom. Such as the liquid crystal alignment agent of claim item 1, wherein, the amount of the epoxy compound represented by the formula (2) is 0.1~ 50 parts by mass. The liquid crystal alignment agent as claimed in item 1, wherein the epoxy compound represented by the formula (2) contains at least 1 of the epoxy compound represented by the following formula (e2-1) ~ the epoxy compound represented by the formula (e2-25) kind,

. Such as the liquid crystal alignment agent of claim item ₁ , wherein, the X1 is derived from a 4-valent organic group of aliphatic tetracarboxylic dianhydride or its derivatives, and a 4-valent organic group derived from alicyclic tetracarboxylic dianhydride or its derivatives. group, or a 4-valent organic group derived from an aromatic tetracarboxylic dianhydride or a derivative thereof. Such as the liquid crystal alignment agent of claim 1, wherein, the _Y1 is selected from diamines represented by the following formula (O), diamines having amide bonds or urea bonds, 3,3'-diaminodiphenyl Methane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylketone, 1,4-bis(4-amine phenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, diamine represented by the following formula (d _o ), 4-( 2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, and the group "-N(D)-" (D represents a protecting group that is removed by heating and replaced by a hydrogen atom) The diamines in the group composed of diamines have taken away the divalent organic groups of two amine groups,

In formula (O), Ar represents a 2-valent benzene ring, a biphenyl structure, or a naphthalene ring; 2 Ar can be the same or different, and any hydrogen atom on the ring in Ar can also be substituted by a 1-valent substituent; p is an integer of 0 or 1; Q ₂ represents -(CH ₂ ) _n -(n is an integer of 2 to 18), or at least a part of the -CH ₂ - of the -(CH ₂ ) _n - is replaced by -O-,- A group substituted by any one of C(=O)- and -OC(=O)-,

In the formula (d _O ), when a plurality of m exists, each of the plurality of m may be the same or different. Such as the liquid crystal alignment agent of claim item ₁ , wherein, the Y is selected from diamine, 2,4-diaminophenol, 3,5-diaminophenol, 3,5- The diamines in the group consisting of diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, and diamines with carboxyl groups have removed two amine groups. 2-valent organic group. A liquid crystal alignment agent, characterized by meeting at least one selected from the group consisting of the following (I') and (II') and the following (III'): (I'): containing The polymer (A') of the repeating unit represented by the repeating unit represented by (1'-a) and the repeating unit represented by the following formula (1'-i), and the epoxy represented by the following formula (2') Compound (B'), (II'): the reaction product containing the polymer (A') and the epoxy compound (B'), (III'): the amount of the epoxy compound represented by the formula (2') 0.1 to 50 parts by mass relative to 100 parts by mass of the total of the polymer (A') and other polymers other than the polymer (A'),

In formula (1'-a) and formula (1'-i), X _1' represents a 4-valent organic group; Y _1' represents a substructure selected from the following formula (d _Y' -1), the following formula ( The substructure represented by d _Y' -2) and the divalent organic group of at least one substructure in the group formed by the nitrogen-containing heterocyclic ring; the two R _1' and Z _1' each independently represent a hydrogen atom , alkyl with 1 to 6 carbons, alkenyl with 2 to 6 carbons, alkynyl with 2 to 6 carbons, tert-butoxycarbonyl, 9-fenylmethoxycarbonyl, 1 to 6 carbons Alkylsilyl, or a monovalent organic group in which at least one of the hydrogen atoms possessed by the alkyl, alkenyl or alkynyl is replaced by a halogen atom or a nitro group; R _1' and Z _1' can be the same or can be different;

In the formula (d _Y' -1), R represents a hydrogen atom or a monovalent organic group; in the formula (d _Y' -1) ~ (d _Y' -2), any hydrogen atom on the benzene ring can also be monovalent The substituent replaces, * represents the atomic bond,

In formula (2'), R _o represents an alkyl group having 1 to 5 carbons, an alkenyl group having 2 to 5 carbons, an alkynyl group having 2 to 5 carbons, a phenyl group, or a carbon-carbon bond between the alkyl groups. A monovalent organic group (q) formed by introducing -O-, or at least one of the hydrogen atoms possessed by the alkyl group, the alkenyl group, the alkynyl group, the phenyl group, or the monovalent organic group (q) is replaced by a hydroxyl group , a halogen atom, a nitro group, or a monovalent organic group substituted with a cyano group. The liquid crystal alignment agent according to Claim 7, wherein the polymer (A') is a polymer in which the repeating unit represented by the formula (1'-a) accounts for more than 5 mol% of all repeating units. The liquid crystal alignment agent as claimed in item 7, wherein the epoxy compound represented by the formula (2') is a compound represented by the following formulas (e2'-1)~(e2'-11) and the compound represented by the formula (2') Epoxy compounds are used alone or in combination of two or more,

. The liquid crystal alignment agent according to any one of claims 1 to 9, wherein the liquid crystal alignment agent further has a cross-linking compound and/or an adhesion assistant. A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 10. A liquid crystal display element comprising the liquid crystal alignment film according to claim 11.

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