TW202045586A - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal element using this - Google Patents

Abstract

A liquid crystal alignment agent is provided which can form a liquid crystal alignment film that has minimal occurrence of afterimages resulting from remaining DC, or AC afterimages, and that is easy to rework and has high transmittance. This liquid crystal alignment agent contains a polymer (A) having the repeating unit represented by formula (1), and a polymer (B) having the repeating unit represented by formula (2), the repeating unit represented by formula (3), the repeating unit represented by formula (4), and the repeating unit represented by formula (5). (In formula (1), X1 is a tetravalent organic group, and Y1 is a divalent organic group. In formulas (2)-(5), X2 is a divalent organic group. In formulas (2)-(5), X2 is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride, and Y2 is a divalent organic group represented by formula (m-1) or (m-2). R2-5 is a hydrogen atom or an alkyl group of 1-4 carbons. Z21-51, Z22-52 are each independently a hydrogen atom, etc., and * represents a bond. X3 is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride. Y3 is a divalent organic group having a partial structure represented by formula (1) or formula (n). In formulas (1) and (n), Q1 and Q2 represent an alkyl group of 1-3 carbons, and Q3 represents a hydrogen atom or an alkyl group of 1-3 carbons. X4 and X5 are tetravalent groups derived from an aromatic acid dianhydride. Y4 is defined the same as Y22 in formula (2), and Y5 is defined the same as Y3 in formula (3).

Description

Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element using the same

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

Since the past, liquid crystal devices have been widely used as display units for personal computers, mobile phones, smart phones, and television receivers. For example, a liquid crystal device is provided with a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for inputting an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, and is supplied to the picture Thin-film transistors (TFT), etc. for electrical signal switches of element electrodes. As a driving method for liquid crystal molecules, a longitudinal electric field method such as a TN method and a VA method, or a lateral electric field method such as an IPS method and an FFS (Fringe Field Switch) method are known (for example, Patent Document 1).

Generally speaking, the horizontal electric field method in which electrodes are formed on only one side of the substrate and the electric field is input in a direction parallel to the substrate is used in contrast to the vertical electric field method in which the liquid crystal is driven by applying voltage to the electrodes formed on the upper and lower substrates in the past. In comparison, it can be used as a liquid crystal display device with a wider viewing angle and a higher-quality display. As a method of aligning liquid crystals in a certain direction, there is a method of forming a polymer film such as polyimide on a substrate, wiping the surface with a cloth, and performing a so-called rubbing treatment. This method is also widely used in industry.

The liquid crystal alignment film, which is a constituent member of the liquid crystal display element, is a film for which liquid crystals are to be uniformly arranged, but the demand for liquid crystals is not only in alignment uniformity, but also has various characteristics. For example, by driving the voltage of the liquid crystal to accumulate charges on the liquid crystal alignment film, the accumulated charges will disturb the alignment of the liquid crystal, or there will be afterimages or burn-in (hereinafter referred to as afterimages from residual DC), which may cause display As a result, the display quality of the liquid crystal display element is significantly reduced. Therefore, a liquid crystal alignment agent that overcomes these problems has been proposed (Patent Document 2).

Moreover, for the IPS method or the FFS method, the stability of the liquid crystal alignment is also important. If the alignment stability is small, when the liquid crystal is driven for a long time, the liquid crystal cannot be restored to the initial state, which may cause a decrease in contrast or burn-in (hereinafter referred to as AC residual image). As a method for solving the above-mentioned problems, Patent Document 3 has disclosed that it contains one polymer selected from the group of polyamide acids containing specific tetracarboxylic dianhydrides and specific diamines and their imidized polymers. Liquid crystal alignment agent with specific compounds.

And because the economic efficiency in the production step is very important, it is necessary to easily recycle the element substrate. In other words, when a liquid crystal alignment film is formed from a liquid crystal alignment agent and inspections such as alignment are performed and defects occur, a technique is expected that can be easily implemented by removing the liquid crystal alignment film from the substrate and recycling the substrate. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2013-167782 A [Patent Document 2] International Publication No. WO02/33481 Handbook [Patent Document 3] International Publication No. WO2016/063834 Handbook

[Problem Solved by Invention]

The structure of the liquid crystal alignment agent proposed in the past may not necessarily achieve all the above-mentioned problems. In addition, when the liquid crystal alignment agent described in Patent Document 2 or 3 is used, the transmittance of the resulting liquid crystal alignment film is too low, and there is still room for improvement. The present invention is based on the above matters, and the object is to provide a liquid crystal alignment agent that can form a liquid crystal alignment film with less residual DC or AC residual images, easy rework, and high transmittance. [Means to solve the problem]

(式(1)中，X₁ 為4價有機基，Y₁ 為2價有機基)

(X₂ 為來自脂環式酸二酐或脂肪族酸二酐之4價有機基。Y₂ 為下述式(m-1)或(m-2)所示2價有機基。R₂ 為氫原子，或碳數1～4的烷基。Z₂₁ 、Z₂₂ 各獨立為氫原子、可具有取代基之碳數1～10的烷基、可具有取代基之碳數2～10的烯基、可具有取代基之碳數2～10的炔基、tert-丁氧基羰基，或9-芴基甲氧基羰基)

(*表示鍵結手)

(X₃ 為來自脂環式酸二酐或脂肪族酸二酐之4價有機基。Y₃ 為下述式(l)所示2價有機基，或具有下述式(n)所示部分結構的2價有機基。R₃ 為氫原子，或碳數1～4的烷基。Z₃₁ 、Z₃₂ 各獨立為氫原子、可具有取代基之碳數1～10的烷基、可具有取代基之碳數2～10的烯基、可具有取代基之碳數2～10的炔基、tert-丁氧基羰基，或9-芴基甲氧基羰基)。

(Q¹ 、Q² 為碳數1～3的烷基，Q³ 為氫原子或碳數1～3的烷基。*表示鍵結手)。

(X₄ 、X₅ 為來自芳香族酸二酐的4價有機基。Y₄ 與式(2)的Y₂ 同義，R₄ 與前述式(2)的R₂ 同義。Z₄₁ 、Z₄₂ 各與前述式(2)的Z₂₁ 、Z₂₂ 同義。Y₅ 與前述式(3)的Y₃ 同義，R₅ 與前述式(3)的R₃ 同義，Z₅₁ 、Z₅₂ 各與前述式(3)的Z₃₁ 、Z₃₂ 同義。) [發明之效果]The inventors of the present invention conducted detailed studies and found that by using a liquid crystal alignment agent containing specific components, the above-mentioned problems can be solved, and the present invention was completed. The present invention has the following as its gist. A liquid crystal alignment agent which contains the following (A) component and (B) component as a characteristic. (A) Component: Polymer (A) having a repeating unit represented by the following formula (1). (B) component: having a repeating unit represented by the following formula (2), a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5), The total content of the repeating unit shown in the following formula (2) and the repeating unit shown in the following formula (3) is 60 to 99.9 mol% of the total repeating unit, and the repeating unit shown in the following formula (4) and the following The polymer (B) in which the total content of the repeating units represented by the formula (5) is 0.1-40 mol% of the total repeating units.

(In formula (1), X ₁ is a tetravalent organic group, and Y ₁ is a divalent organic group)

(X ₂ is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride. Y ₂ is a divalent organic group represented by the following formula (m-1) or (m-2). R ₂ is A hydrogen atom, or an alkyl group having 1 to 4 carbons. Z ₂₁ and Z _{22 are} each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbons, an optionally substituted alkylene group having 2 to 10 carbons Group, optionally substituted alkynyl with 2 to 10 carbons, tert-butoxycarbonyl, or 9-fluorenylmethoxycarbonyl)

(* indicates the bond hand)

(X ₃ is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride. Y ₃ is a divalent organic group represented by the following formula (l), or has a part represented by the following formula (n) A bivalent organic group of the structure. R ₃ is a hydrogen atom, or an alkyl group having 1 to 4 carbons. Z ₃₁ and Z _{32 are} each independently a hydrogen atom, and an optionally substituted alkyl group having 1 to 10 carbons may have The substituent is an alkenyl group having 2 to 10 carbon atoms, an optionally substituted alkynyl group having 2 to 10 carbon atoms, tert-butoxycarbonyl, or 9-fluorenylmethoxycarbonyl).

(Q ¹ and Q ² are an alkyl group having 1 to 3 carbons, and Q ³ is a hydrogen atom or an alkyl group having 1 to 3 carbons. * represents a bonding hand).

(X _4, Y ₂ X ₅ is synonymous from a tetravalent aromatic organic dianhydride _4-yl .Y formula (2), R ₄ and R ₂ .Z the same meaning as formula (2) is _41, Z ₄₂ each and Z _21, Z ₂₂ and Y .Y ₅ synonymous the formula (3) is synonymous _3, R _{5 3} R synonymous with the aforementioned formula (3), Z _51, Z ₅₂ and each of the formula (the formula (2) 3) Z ₃₁ and Z _{32 are} synonymous.) [Effects of the invention]

According to the liquid crystal alignment agent of the present invention, a liquid crystal alignment film with easy rework and high transmittance can be obtained. In addition, by using the obtained liquid crystal alignment film, a liquid crystal display element with high transmittance and excellent contrast can be obtained, which is difficult to generate residual DC or AC residual images.

[Type of Implementation of Invention]

Hereinafter, each component contained in the liquid crystal alignment agent of the present invention, and other components optionally blended as necessary will be described. <Polymer (A)> The liquid crystal alignment agent of the present invention contains a polymer (A) having a repeating unit represented by the above formula (1). Thereby, it is possible to obtain a liquid crystal alignment film with less AC residual image generation and high transmittance, and a liquid crystal display element with suppressed contrast reduction can be obtained. For the above formula (1), X ₁ and Y _{1 are} as defined above. X _{1 of the} formula (1) includes a tetravalent organic group derived from tetracarboxylic dianhydride, for example, tetravalent organic groups derived from aromatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic acid The tetravalent organic group of acid dianhydride. Y ₁ in the formula (1) is preferably a divalent organic group derived from a diamine compound.

Here, the term "aromatic tetracarboxylic dianhydride" refers to an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups containing at least one carboxyl group bonded to an aromatic ring. The so-called aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, it does not need to be formed only with a chain hydrocarbon structure, and may have an alicyclic structure or an aromatic ring structure in this part. The so-called alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups containing at least one carboxyl group bonded to an alicyclic structure. However, none of these 4 carboxyl groups are bonded to the aromatic ring. Moreover, it does not need to be composed only of an alicyclic structure, and may have a chain hydrocarbon structure or an aromatic ring structure in this part.

(x及y各獨立為單鍵、醚(-O-)、羰基(-CO-)、酯( -COO-)、碳數1～5的烷烴二基、1,4-伸苯基、磺醯基或醯胺基。Z¹ ～Z⁶ 各獨立表示氫原子、甲基、乙基、丙基、氯原子或苯環。j各獨立為0或1的整數。m為1～5的整數。*表示鍵結手。)From the viewpoint of improving the solubility of the polymer (A), X ₁ is a tetravalent organic group selected from the group consisting of the following formulas (4a) to (4n), the following formula (5a) and the following formula (6a) The one is better.

(x and y are each independently a single bond, ether (-O-), carbonyl (-CO-), ester (-COO-), alkanediyl group with 1 to 5 carbon atoms, 1,4-phenylene, sulfonate An amide group or an amide group. Z ¹ to Z ⁶ each independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom, or a benzene ring. Each j is independently an integer of 0 or 1. m is an integer of 1 to 5. .* indicates the bond hand.)

From the viewpoint of less AC residual image, as a preferable specific example of the aforementioned formula (4a), the structures represented by the following formulas (4a-1) to (4a-4) can be cited.

Examples of the alkanediyl groups having 1 to 5 carbon atoms in the aforementioned formulas (5a) and (6a) include methylene, ethylene, 1,3-propanediyl, 1,4-butanediyl, 1,5-Pentanediyl and so on. For less AC residual images and from the viewpoint of ensuring solubility, X ₁ in the aforementioned formula (1) is selected from the aforementioned formulas (4a)～(4h), (4j), (4l), (4m)～(4n) ) Is preferred.

The diamine that can be used for the polymer (A) is not particularly limited. As a specific example, as aliphatic diamine, metaxylylenediamine, ethylenediamine, 1,3-propane diamine, tetramethylene diamine, hexamethylene diamine, etc. are mentioned, for example. As an alicyclic diamine, p-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine), etc. are mentioned, for example.

(Q¹¹ 為-NQCO-、-COO-、-OCO-、-NQCONQ-、-CONQ-或-(CH₂ )_n -(n為1～20的整數)但，n為2～20時，任意的-CH₂ -在各未鄰接的條件下，可取代為-O-、-COO-、-OCO-、-ND-、-NQCO-、-CONQ-、-NQCONQ-、-NQCOO-或-OCOO-。D表示熱脫離性基，Q表示氫原子或1價有機基。Q¹² 為單鍵或苯環，於苯環上的任意氫原子可取代為1價有機基。*1、*2表示鍵結手，Q¹² 為單鍵時，*2鍵結於胺基中之氮原子。Q¹² 為苯環時，Q¹¹ 可為單鍵。)Examples of aromatic diamines include p-phenylene diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diamine Azobenzene, 3,5-diaminobenzoic acid, bis(4-aminophenyl)amine, N,N-bis(4-aminophenyl)methylamine, 1,4-bis(4 -Aminophenyl)-piperazine, N,N'-bis(4-aminophenyl)-benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1 ,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]ether, 4 ,4'-bis(4-aminophenoxy)biphenyl, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 4,4'-[ 4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane , Diamines etc. in which two amine groups are bonded to a divalent organic group having a partial structure represented by the following formula (H).

(Q ¹¹ is -NQCO-, -COO-, -OCO-, -NQCONQ-, -CONQ- or -(CH ₂ ) _n- (n is an integer from 1 to 20) However, when n is 2 to 20, any The -CH ₂ -can be substituted with -O-, -COO-, -OCO-, -ND-, -NQCO-, -CONQ-, -NQCONQ-, -NQCOO- or -OCOO under the condition that each is not adjacent -. D represents a thermally detachable group, Q represents a hydrogen atom or a monovalent organic group. Q ¹² is a single bond or a benzene ring, and any hydrogen atom on the benzene ring can be substituted with a monovalent organic group. *1, *2 represent Bonding hands, when Q ¹² is a single bond, *2 is bonded to the nitrogen atom in the amine group. When Q ¹² is a benzene ring, Q ¹¹ can be a single bond.)

(*1、*2表示鍵結手，*2表示鍵結於醯亞胺環中之氮原子。)From the viewpoint of less AC residual image, Y _{1 of the} aforementioned formula (1) is preferably one having a divalent organic group having a partial structure represented by the aforementioned formula (H). In this case, when R ⁴ of the aforementioned formula (H) is a single bond, *2 is bonded to the nitrogen atom in the imine ring. Among them, Y _{1 of the} aforementioned formula (1) is also preferably a divalent organic group having a partial structure shown in any of the following formulas (H-1) to (H-14).

(*1, *2 represent the bonding hands, *2 represents the nitrogen atom bonded to the imine ring.)

(*1與醯亞胺環中之氮原子鍵結。Boc表示tert-丁氧基羰基。)From the viewpoint of ease of synthesis, Y ₁ of the aforementioned formula (1) is represented by any one of the aforementioned formulas (H-1) to (H-14) or the following formula (MH-1) The divalent organic group shown in ~(MH-2) is preferred.

(*1 Bonds to the nitrogen atom in the imine ring. Boc represents tert-butoxycarbonyl.)

The polymer (A) may have a repeating unit represented by the following formula (PA-1) in addition to the repeating unit represented by the above formula (1).

In the formula (PA-1), X ₁ and Y _{1 are} each synonymous with X ₁ and Y ₁ of formula (1) containing a preferred aspect. R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z ₁₁ and Z _{12 are} each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbons, an optionally substituted alkenyl group having 2 to 10 carbons, and an optionally substituted carbon number of 2-10 Alkynyl, tert-butoxycarbonyl, or 9-fluorenylmethoxycarbonyl.

Specific examples of the alkyl group having 1 to 5 carbon atoms in R ₁ include methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, s-butyl, t -Butyl, n-pentyl, etc. From the viewpoint of easy imidization by heating, R _{1 is} preferably a hydrogen atom or a methyl group.

As specific examples of the alkyl group having 1 to 10 carbons in the above-mentioned Z ₁₁ and Z ₁₂ , in addition to the specific examples of the alkyl group having 1 to 5 carbons as exemplified in the above R ₁ , hexyl, heptyl Base, octyl, nonyl, decyl, etc. Specific examples of the alkenyl group having 2 to 10 carbon atoms of Z ₁₁ and Z ₁₂ include, for example, vinyl, propenyl, butynyl, and the like, and these may be linear or branched. Specific examples of the alkynyl group having 2 to 10 carbon atoms in Z ₁₁ and Z ₁₂ include, for example, an ethynyl group, a 1-propynyl group, and a 2-propynyl group.

Z ₁₁ and Z ₁₂ may have a substituent. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a hydroxyl group, a cyano group, and an alkoxy group. From the viewpoint of less AC residual image, it is preferable that Z ₁₁ and Z ₁₂ each independently be a hydrogen atom or a methyl group. From the viewpoint of less AC residual image, the content ratio of the repeating unit represented by the aforementioned formula (1) in the polymer (A) is 10 to 95 mole% of the total repeating unit of the polymer (A) Best, preferably 15 to 95 mole%. In addition, at this time, the content ratio of the repeating unit represented by the above formula (PA-1) in the polymer (A) is preferably 5 to 90 mol%, and more preferably 5 to 85 mol%.

<Polymer (B)> The liquid crystal alignment agent of the present invention contains the repeating unit represented by the above formula (2), the repeating unit represented by the above formula (3), the repeating unit represented by the above formula (4), and the above formula (5). The repeating unit shown in ), the total amount of the repeating unit shown in the above formula (2) and the repeating unit shown in the above formula (3) is 60 to 99.9 mol% of the total repeating unit of the polymer (B). With such a configuration, a liquid crystal alignment film with excellent reworkability and reduced residual images from residual DC can be obtained. For the above formulas (2) and (3), X ₂ , X ₃ , Y ₂ , Y ₃ , R ₂ , R ₃ , Z ₂₁ , Z ₂₂ , Z ₃₁ and Z _{32 are the} same as the above definitions.

As the _2, R Specific examples of the alkyl group of R having 1 to ₃ carbon atoms 5 can include _1, R configuration illustrated above formula (PA-1) a. From the viewpoint of easy imidization by heating, R ₂ and R _{3 are} each independently a hydrogen atom or a methyl group. As specific examples of the above-mentioned Z ₂₁ , Z ₂₂ , Z ₃₁ , and Z ₃₂ , the alkyl group having 1 to 10 carbons, the alkenyl group having 2 to 10 carbons, and the alkynyl group having 2 to 10 carbons, the above formula ( The structure exemplified in Z _{11 and} Z ₁₂ of PA-1). Z ₂₁ , Z ₂₂ , Z ₃₁ , and Z ₃₂ may have a substituent. Examples of the substituent include the structures exemplified by Z _{11 and} Z _{12 in} the above formula (PA-1). From the viewpoint of less AC residual image, Z ₂₁ , Z ₂₂ , Z ₃₁ , and Z ₃₂ are preferably hydrogen atoms or methyl groups independently.

As the tetravalent organic group derived from the alicyclic tetracarboxylic dianhydride or aliphatic tetracarboxylic dianhydride derived from the above X ₂ and X ₃ , the alicyclic tetracarboxylic dianhydride derived from the above X ₁ exemplified or The tetravalent organic group of aliphatic tetracarboxylic dianhydride. From the viewpoint of suppressing AC afterimages, X ₂ and X _{3 are} preferably selected from the group of tetravalent organic groups formed by the above formulas (4a) to (4n).

Examples of the alkyl group having 1 to 3 carbon atoms for Q ¹ , Q ² , and Q ³ in the above formula (1) or (n) include methyl, ethyl, propyl, and the like. From the viewpoint of increasing the transmittance of the liquid crystal alignment film and suppressing AC residual images and residual DC residual images, it is preferable that Q ¹ , Q ² , and Q ³ are methyl groups. Moreover, any hydrogen atom of the benzene ring in formula (n) may be substituted by a monovalent organic group. Examples of the monovalent organic group include an alkyl group, alkenyl group, alkoxy group, fluoroalkyl group, fluoroalkenyl group, or fluoroalkoxy group having 1 to 3 carbon atoms.

From the viewpoint of less AC residual image, the above formula (1) has a structure represented by the following formula (1-1).

Regarding the above formula (n), from the viewpoint of fewer steric obstacles in the bonding position of -NQ ³ -Ph (Ph represents phenylene), it is preferable to bond to the third position of the carbazole skeleton. From the viewpoint of fewer residual images from residual DC, the divalent organic group having a partial structure represented by the aforementioned formula (n) is selected from the group consisting of the following formulas (n-1) to (n-3) Divalent organic base is preferred.

(Q⁵ 表示選自單鍵、-O-、-COO-、-OCO-、-(CH₂ )_l -、 -O(CH₂ )_m O-、-CONQ-及-NQCO-的2價有機基，k表示1～5的整數。且Q表示氫或者一價有機基，l、m表示1～5的整數。*1、*2表示鍵結手，*₁ 表示與式(n-1)～式(n-3)中之苯環鍵結。) 作為前述式(Ar)之Q中之一價有機基，可舉出碳數1～3的烷基。In the formulas (n-1) to (n-3), each of Q ² and Q ^{3 has} the same meaning as the preferred specific examples including Q ² and Q ^{3 of} the aforementioned formula (n). Q ⁴ represents a single bond or the structure of the following formula (Ar), and n represents an integer of 1-3. * Indicates the bond hand. Furthermore, any hydrogen atom of the benzene ring can be substituted with a monovalent organic group as in the case of the above formula (n).

(Q ⁵ represents a divalent organic compound selected from single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONQ- and -NQCO- Base, k represents an integer from 1 to 5. Q represents hydrogen or a monovalent organic group, l and m represent an integer from 1 to 5. *1, *2 represent the bonding hands, * ₁ represents the formula (n-1) -The benzene ring in the formula (n-3) is bonded.) As the monovalent organic group in Q in the aforementioned formula (Ar), an alkyl group having 1 to 3 carbon atoms can be cited.

From the viewpoint of ease of synthesis, the divalent organic group having the partial structure represented by the aforementioned formula (n) is preferably one represented by any one of the following formulas (cbz-1) to (cbz-7). * Indicates the bond hand.

The aforementioned polymer (B) has less AC residual image and residual DC-derived residual image. As a repeating unit represented by the aforementioned formula (3), Y ₃ is a divalent organic compound represented by the aforementioned formula (1). repeating units of the group, and Y ₃ having (n) of repeating units are divalent organic group represented by partial structure of the foregoing preferred formula.

The aforementioned polymer (B) has a repeating unit represented by the following formula (4) and a repeating unit represented by the following formula (5) from the viewpoint of less residual images from residual DC.

In formulas (4) and (5), X ₄ and X ₅ are tetravalent organic groups derived from aromatic tetracarboxylic dianhydrides, and examples include those derived from aromatic tetracarboxylic groups as exemplified in X _{1 of} the aforementioned formula (1) The tetravalent organic group of acid dianhydride. From the viewpoint of less AC residual image and residual image from residual DC, X ₄ and X ₅ are selected from the tetravalent organic groups of formulas (5a) and (6a) described in the preferred examples of X ₁ above Better.

Y ₄ is synonymous with Y _{2 in the} aforementioned formula (2) and those containing better aspects. R ₄ is synonymous with R _{2 in the} aforementioned formula (2) and those containing preferred aspects. Z ₄₁ and Z _{42 are} each synonymous with Z ₂₁ , Z _{22 in the} aforementioned formula (2) and those containing better aspects. Y ₅ is synonymous with Y _{3 in the} aforementioned formula (3) and those containing better aspects. R ₅ is synonymous with R _{3 in the} aforementioned formula (3) and those containing preferred aspects. Z ₅₁ and Z _{52 are} each synonymous with Z ₃₁ , Z _{32 in the} foregoing formula (3) and those containing better aspects.

For the polymer (B), the total content of at least one repeating unit selected from the repeating unit represented by the above formula (2) and the repeating unit represented by the above formula (3), from the viewpoint of obtaining high transmittance It can be seen that 60-99.9 mol% of the total repeat unit is better, and 65-90 mol% is better. The content ratio of the repeating unit shown in the above formula (2) to the repeating unit shown in the above formula (3), the molar% ratio of the former/the latter is preferably 10/90-50/50, and 15/85-50 /50 is better. The total content of at least one repeating unit selected from the repeating unit represented by the above formula (4) and the repeating unit represented by the above formula (5) in the polymer (B), from the viewpoint that high transmittance can be obtained In view of this, 0.1-40 mol% of the total repeating unit is preferred, and 10-35 mol% is preferred. When the ratio of the content of the repeating unit represented by the above formula (4) to the content of the repeating unit represented by the above formula (5) is expressed by the molar% ratio of the former/the latter, the ratio of 10/90-50/50 is preferred, and 15 /85-50/50 is preferred.

In addition to the repeating unit represented by the above formula (2), the repeating unit represented by the above formula (3), the repeating unit represented by the above formula (4), and the repeating unit represented by the above formula (5), the polymer (B) may also have The repeating unit represented by the following formula (PA-2).

In the formula (PA-2), X ₆ represents a tetravalent organic group, and Y ₆ represents a divalent organic group. However, Y ₆ is a group selected from the above formulas (m-1) to (m-2), and does not contain the divalent organic group represented by the above formula (l) and the divalent organic group having the partial structure represented by the above formula (n) Organic base. R ₆ is synonymous with R _{2 in the} aforementioned formula (2) and those containing preferred aspects. Z _61, Z ₆₂ and Z ₆₁ in the formula (2), Z ₆₂ and those containing preferred aspects synonymous.

(式(pr)中，R¹ 表示氫原子、氫、氟原子、氰基、羥基、甲基，R² 各獨立表示單鍵或基「*1-R³ -Ph-*2」，R³ 表示選自單鍵、-O-、-COO-、-OCO-、-(CH₂ )_l -、-O(CH₂ )_m O-、-CONH-及-NHCO-的2價有機基(l、m表示1～5的整數)、*1表示與式(pr)中之苯環鍵結的位置，*2表示與式(pr)中之胺基鍵結的位置。Ph表示伸苯基。n表示1～3)、在WO2018/062197號所記載的來自具有吡咯結構的二胺之結構、較佳為來自具有下式(pn)所示結構的二胺之結構、

(式(pn)中，R¹ 及R² 表示氫原子或甲基，R³ 各獨立表示單鍵或基「*1-R⁴ -Ph-*2」，R⁴ 表示選自單鍵、-O-、 -COO-、-OCO-、-(CH₂ )_l -、-O(CH₂ )_m O-、-CONH-及 -NHCO-的2價有機基(l、m表示1～5的整數)、*1表示與式(pn)中之苯環鍵結的位置，*2表示與式(pn)中之胺基鍵結的位置。Ph表示伸苯基。n表示1～3)、在WO2018/092759號所記載的來自具有噻吩或呋喃結構的二胺之結構，較佳為來自具有下式(sf)所示結構的二胺之結構、

(式(sf)中，Y¹ 表示硫原子或氧原子，R² 各獨立表示單鍵或基「*1-R⁵ -Ph-*2」，R⁵ 表示選自單鍵、-O-、-COO-、 -OCO-、-(CH₂ )_l -、-O(CH₂ )_m O-、-CONH-及-NHCO-的2價有機基(l、m表示1～5的整數)，*1表示與式(pn)中之苯環鍵結的位置，*2表示與式(pn)中之胺基鍵結的位置。Ph表示伸苯基。n表示1～3。)、在WO2018-181566號之段落[0013]～[0030]所記載的2價有機基等。As a specific example of X ₆ , tetravalent derived from aromatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, and alicyclic tetracarboxylic dianhydride exemplified in X _{1 of} the above formula (1) Organic base. As a specific example of Y ₆ , in addition to the structure derived from diamine exemplified in Y _{1 of} the above formula (1), the derived structure described in International Publication (hereinafter also referred to as WO) No. 2017/126627 The structure of a diamine having a pyrrole structure is preferably a structure derived from a diamine having a structure represented by the following formula (pr),

(In formula (pr), R ¹ represents hydrogen atom, hydrogen, fluorine atom, cyano group, hydroxyl group, methyl group, R ² each independently represents a single bond or a group "*1-R ³ -Ph-*2", R ³ Represents a divalent organic group selected from single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO- (l , M represents an integer from 1 to 5), *1 represents the position of bonding with the benzene ring in formula (pr), *2 represents the position of bonding with the amine group in formula (pr). Ph represents phenylene. n represents 1 to 3), a structure derived from a diamine having a pyrrole structure described in WO2018/062197, preferably a structure derived from a diamine having a structure represented by the following formula (pn),

(In the formula (pn), R ¹ and R ² represent a hydrogen atom or a methyl group, R ³ each independently represents a single bond or a group "*1-R ⁴ -Ph-*2", and R ⁴ represents a single bond,- O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO- divalent organic groups (l, m represent 1～5 Integer), *1 represents the position of bonding with the benzene ring in formula (pn), *2 represents the position of bonding with the amine group in formula (pn). Ph represents phenylene. n represents 1 to 3), The structure derived from a diamine having a thiophene or furan structure described in WO2018/092759 is preferably a structure derived from a diamine having a structure represented by the following formula (sf),

(In formula (sf), Y ¹ represents a sulfur atom or an oxygen atom, R ² each independently represents a single bond or a group "*1-R ⁵ -Ph-*2", and R ⁵ represents a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO- divalent organic groups (l, m represent an integer of 1 to 5), *1 represents the position of bonding with the benzene ring in formula (pn), *2 represents the position of bonding with the amine group in formula (pn). Ph represents phenylene. n represents 1 to 3.), in WO2018 -Divalent organic groups described in paragraphs [0013] to [0030] of No. 181566.

From the viewpoint of less AC residual image and residual DC residual image, the content ratio of the aforementioned polymer (A) to the aforementioned polymer (B) is the weight ratio of polymer (A)/polymer (B) Below 5/95～95/5 is better. From the viewpoint of obtaining a highly reproducible liquid crystal alignment film, the above-mentioned polymer (A)/polymer (B) is preferably 10/90 to 90/10, and more preferably 20/80 to 80/20 .

＜Method of manufacturing polyamide acid＞ The polyamide used in the polyimide precursor of the present invention can be synthesized by the method shown below. Specifically, the tetracarboxylic dianhydride and diamine can be carried out at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours in the presence of an organic solvent, preferably Synthesized by reaction within 1-12 hours. The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone or γ-butyrolactone in view of the solubility of monomers and polymers , These can be used singly or in combination of two or more. The concentration of the polymer is preferably 1-30% by weight, and more preferably 5-20% by weight, from the viewpoint that it is not easy to cause precipitation of the polymer and that the polymer is easily obtained.

The polyamide acid obtained as described above can be injected into a poor solvent while fully stirring the reaction solution, so that the polymer can be deposited and recovered. In addition, after performing precipitation several times and washing with a poor solvent, it is purified by normal temperature or heating and drying to obtain a powder of polyamide acid. Although the poor solvent is not particularly limited, water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc. can be mentioned.

＜Method of producing polyamide ester＞ The polyamide ester used in the polyimide precursor of the present invention can be synthesized, for example, by the method (1), (2) or (3) shown below. (1) Synthesis of polyamide acid Polyamide ester can be synthesized by esterifying tetracarboxylic dianhydride and polyamide acid obtained from diamine. Specifically, the polyamide acid and the esterification agent can be carried out at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours in the presence of an organic solvent. It is synthesized for 1 to 4 hours of reaction.

The esterification agent is preferably one that can be easily removed by purification, and examples include N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide bis-t- Butyl acetal, 1-methyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl Morpholinium chloride, etc. The amount of the esterification agent used is preferably 2-6 mol equivalents for 1 mol of the repeating unit of polyamide acid. The solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone or γ-butyrolactone from the viewpoint of the solubility of the polymer. Mix two or more kinds to use. The concentration during synthesis is preferably 1-30% by weight, and more preferably 5-20% by weight from the standpoint of not easily causing the precipitation of the polymer and easily obtaining a polymer.

(2) Synthesis by reaction of tetracarboxylic acid diester dichloride and diamine Polyurethane can be synthesized from tetracarboxylic acid diester dichloride and diamine. Specifically, tetracarboxylic acid diester dichloride and diamine can be carried out in the presence of a base and an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 It is preferably synthesized by reacting for 1 to 4 hours. Among the aforementioned bases, pyridine, triethylamine, etc. can be used. Among them, pyridine is preferred in view of the stable progress of the reaction. From the viewpoint that the amount of alkali used can be easily removed and the polymer can be easily obtained, the tetracarboxylic acid diester dichloride is preferably 2 to 4 times mol.

The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the standpoint of the solubility of monomers and polymers. Two or more of these can be mixed and used. . The polymer concentration during synthesis is preferably 1-30% by weight, and more preferably 5-20% by weight, from the standpoint of not easily causing the precipitation of the polymer and easily obtaining a polymer. In addition, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, it is better to dehydrate the solvent used in the synthesis of polyamide ester as much as possible, and to prevent the mixing of external air in a nitrogen environment. .

(3) Synthesis of polyamide ester from tetracarboxylic acid diester and diamine Polyurethane can be synthesized by polycondensing a tetracarboxylic acid diester and a diamine. Specifically, the tetracarboxylic acid diester and the diamine can be carried out at 0°C to 150°C, preferably 0°C to 100°C, for 30 minutes to 24 hours in the presence of a condensing agent, alkali and organic solvent. It is preferably synthesized by performing a reaction for 3 to 15 hours.

Among the aforementioned condensing agents, triphenyl phosphite, dicyclohexyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, N, Known compounds such as N'-carbonyldiimidazole and dimethoxy-1,3,5-triazinylmethylmorpholinium. As the aforementioned base, tertiary amines such as pyridine can be used. Among the three methods for producing polyamides, the production method of (1) or (2) above is particularly preferred for obtaining high-molecular-weight polyamides.

＜Production method of polyimide＞ The polyimide used in the present invention can be produced by imidizing the aforementioned polyamide ester or polyamide acid. When producing polyimide from polyamide, add alkaline amine to the aforementioned polyamide solution or to the polyamide solution obtained by dissolving polyamide resin powder in an organic solvent. The chemical imidization of the medium is easily performed. The chemical imidization is to carry out the imidization reaction at a relatively low temperature, and the molecular weight of the polymer is not likely to decrease during the imidization process.

The chemical imidization can be performed by stirring the polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As the organic solvent, the solvent used in the aforementioned polymerization reaction can be used. As a basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. are mentioned. Among them, pyridine is preferred because it has a moderate alkalinity during the reaction. Moreover, as an acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be mentioned, Among them, if acetic anhydride is used, since the purification after completion|finish of reaction becomes easy, it is preferable.

The temperature during the imidization reaction is -20°C to 140°C, preferably 0°C to 100°C, and the reaction time can be 1 to 100 hours. The amount of alkaline catalyst is 0.5 to 30 mole times of the amide acid group, preferably 2 to 20 mol times, and the amount of acid anhydride is 1 to 50 mole times of the amide acid group, preferably 3 to 30 mol times. The imidization rate of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time. In the solution after the imidization reaction of polyamide or polyamide, the added catalyst remains, so the obtained imidization polymer can be recovered by the following methods , It is better to re-dissolve in an organic solvent to be the liquid crystal alignment agent of the present invention.

The polyimide solution obtained as described above can be poured into a poor solvent while being fully stirred to precipitate a polymer. After several times of precipitation and washing with a poor solvent, it is often heated or dried to obtain a purified polyamide powder. Although the said poor solvent is not specifically limited, methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, etc. are mentioned.

＜Liquid crystal alignment agent＞ The liquid crystal alignment agent of the present invention contains polymer (A) and polymer (B). In addition to the polymer (A) and the polymer (B), the liquid crystal alignment agent of the present invention may also contain other polymers. As the types of other polymers, polyamides, polyimides, polyamides, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, and polyacetals can be mentioned. , Polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylates, etc.

The liquid crystal aligning agent is used when producing a liquid crystal alignment film, and the form of the coating liquid is determined from the viewpoint that it can form a uniform and thin film. For the liquid crystal alignment agent of the present invention, it is also preferable to use a coating liquid containing the aforementioned polymer component and an organic solvent. At this time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed by setting the thickness of the coating film to be formed. From the viewpoint that the coating film can be formed uniformly and without defects, 1% by weight or more is preferable, and from the viewpoint of storage stability of the solution, 10% by weight or less is preferable. It is particularly preferable that the concentration of the polymer is 2 to 8% by weight.

The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it can uniformly dissolve the polymer component. To give this specific example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2 -Pyrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N , N-dimethylpropaneamide, 3-butoxy-N,N-dimethylpropaneamide, etc. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropaneamide, 3-butoxy-N, N-dimethylpropaneamide or gamma-butyrolactone.

In addition, the organic solvent contained in the liquid crystal alignment agent is preferably a mixed solvent in addition to the above-mentioned solvents, which can improve the coatability when the liquid crystal alignment agent is applied or the surface smoothness of the coating film. Specific examples of the organic solvent to be used in combination include the following, but are not limited to these examples. For example, diisopropyl ether, diisobutyl ether, diisobutyl methanol (Carbinol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1 , 2-Butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether , Diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, Ethylene glycol monoacetate, ethylene glycol diacetate, ethylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether (butyl cellosolve) Agent), ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy) ethanol, propylene glycol monobutyl ether, 1-(butoxyethoxy) propanol, propylene glycol monomethyl Base ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate (butyl cellosolve acetate), ethylene glycol mono Acetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy) ethyl Acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate , Ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl Base ether, diisobutyl ketone, etc.

Among them, diisobutyl methanol (Carbinol), propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4- Hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and diisobutyl ketone are preferred. The type and content of the solvent can be appropriately selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

As a combination of good solvents and poor solvents, preferred solvents include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolidone Ester 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, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone With γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and two Isopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidine Ketone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether monoacetate, N-methyl-2-pyrrolidone, γ-butyrolactone, ethylene glycol monobutyl ether monoacetate and dipropylene glycol monomethyl ether, etc. The poor solvent is preferably 1 to 80% by weight of the total solvent contained in the liquid crystal alignment agent, preferably 10 to 80% by weight, and particularly preferably 20 to 70% by weight. The type and content of the solvent can be appropriately selected according to the coating device, conditions, and environment of the liquid crystal alignment agent.

The liquid crystal alignment agent of the present invention may additionally contain components other than polymer components and organic solvents. As such additional components, there may be mentioned an adhesion assistant used to improve the adhesion between the liquid crystal alignment film and the substrate or the adhesion between the liquid crystal alignment film and the sealing material, and the compound used to increase the strength of the liquid crystal alignment film (hereinafter also It is called a cross-linking compound), a dielectric or conductive material used to adjust the dielectric rate or resistance of the liquid crystal alignment film.

(式中，Q₃₁ 為氫原子、碳數1～3的烷基或「*-CH₂ -OH」，Q₃₂ 及Q₃₃ 各獨立為氫原子、碳數1～3的烷基或「*-CH₂ -OH」。*表示鍵結手。A表示具有芳香環之(m+n)價有機基。m表示1～6的整數，n表示0～4的整數)As the aforementioned cross-linkable compound, the generation of AC residual image is small, and the film strength improvement effect is high, and it is selected from the group consisting of ethylene oxide, oxetanyl, protective Isocyanate group, protected isothiocyanate group, group containing oxazoline ring structure, group containing maltonic acid structure, cyclic carbonate group and at least one group of groups represented by the following formula (d) A compound, or a compound represented by the following formula (e) (hereinafter collectively referred to as compound (C)) is preferred.

(In the formula, Q ₃₁ is a hydrogen atom, an alkyl group with 1 to 3 carbons or "*-CH ₂ -OH", and Q ₃₂ and Q _{33 are} each independently a hydrogen atom, an alkyl group with 1 to 3 carbons or "* -CH ₂ -OH". * represents a bonding hand. A represents an (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)

As a specific example of the compound having an oxirane group, for example, the compound described in paragraph [0037] of JP 10-338880 A, or the compound having a triazine ring as described in WO2017/170483 Compounds with two or more oxirane groups such as skeleton compounds. Among these, N,N,N',N',-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane Alkyl, N,N,N',N',-tetraglycidyl-4, 4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-p-phenylene Nitrogen atom-containing compounds such as diamines and compounds represented by any of the following formulas (r-1) to (r-3) are particularly preferred.

As a specific example of the compound having an oxetanyl group, for example, a compound having two or more oxetanyl groups described in paragraphs [0170] to [0175] of WO2011/132751 can be cited.

As a specific example of the compound having a protected isocyanate group, for example, a compound having two or more protected isocyanate groups described in paragraphs [0046] to [0047] of JP 2014-224978 A, as described in WO2015/141598 No. Paragraphs [0119] to [0120] described in the compound having 3 or more protected isocyanate groups, etc. Among these, a compound represented by any one of the following formulas (bi-1) to (bi-3) is preferred.

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

As a specific example of the compound having a group containing a maltonic acid structure, for example, a compound having two or more maltonic acid structures described in WO2012/091088 can be cited. As a specific example of the compound which has a cyclic carbonate group, the compound described in WO2011/155577 can be mentioned, for example.

As the C1-C3 alkyl group of R ₁ , R ₂ , and R ₃ of the group represented by the aforementioned formula (d), the groups exemplified in the aforementioned formulas (l) and (n) can be given. As a specific example of a compound having a group represented by the aforementioned formula (d), for example, there can be mentioned in WO2015/072554 or in the paragraph [0058] of JP 2016-118753 A, having two or more aforementioned formulas ( d) Compounds of the indicated groups, compounds described in JP 2016-200798 A, etc. Among these, compounds represented by the following formulas (hd-1) to (hd-8) are preferred.

Examples of the (m+n)-valent organic group having an aromatic ring in A of the aforementioned formula (e) include (m+n)-valent aromatic hydrocarbon groups with 5 to 30 carbons, and aromatics with 5 to 30 carbons. The hydrocarbon group is an (m+n)-valent organic group bonded directly or via a linking group, or a (m+n)-valent group having an aromatic heterocyclic ring. As said aromatic hydrocarbon group, benzene, naphthalene, etc. are mentioned, for example. Examples of aromatic heterocyclic rings include pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring, carbazole ring, pyridazine ring, pyrazine ring, and benzimidazole Ring, benzimidazole ring, indole ring, quinoxaline ring, acridine ring, etc. Examples of the linking group include an alkylene group having 1 to 10 carbon atoms, a group in which one hydrogen atom is removed from the alkylene group, a divalent or trivalent cyclohexane ring, and the like. Furthermore, any hydrogen atom of the aforementioned alkylene group may be substituted with a fluorine atom or an organic group such as a trifluoromethyl group. To give specific examples, the compounds described in WO2010/074269, etc. can be cited. As a preferred specific example, the following formulas (e-1) to (e-11) can be given.

The above-mentioned compound is an example of a crosslinkable compound, but it is not limited to these. For example, components other than those disclosed in [0105] to [0116] of WO2015/060357 can be cited. In addition, two or more types of crosslinkable compounds contained in the liquid crystal alignment agent of the present invention can be combined. In the liquid crystal alignment agent of the present invention, the content of the crosslinkable compound is preferably 0.5 to 20 parts by weight relative to 100 parts by weight of the polymer component contained in the liquid crystal alignment agent, in order to perform the crosslinking reaction to express the desired effect And from the viewpoint of less AC residual image characteristics, it is preferably 1 to 15 parts by weight.

Examples of the adhesion auxiliary agent include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2- Aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminopropyl) Ethyl)-3-aminopropylmethyldimethoxysilane, 3-ureapropyltrimethoxysilane, 3-ureapropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyl trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyl triethylenetriamine, N-trimethoxysilyl Propyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl 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(oxyethylene)-3-aminopropyltriethoxysilane, Vinyl trimethoxysilane, vinyl triethoxy silane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-glycidoxy propyl methyl dimethoxy silane , 3-glycidoxy propyl trimethoxy silane, 3-glycidoxy propyl methyl diethoxy silane, 3-glycidoxy propyl triethoxy silane, p-benzene Ethylene trimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyl Diethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, ginseng-(trimethoxysilylpropyl)isocyanurate Silane coupling agents such as acid ester, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, etc. In the case of using these silane coupling agents, from the viewpoint of less AC residual image, it is preferable to use 0.1-30 parts by weight for 100 parts by weight of the polymer component contained in the liquid crystal alignment agent, and more preferably 0.1- 20 parts by weight.

＜Liquid crystal alignment film, liquid crystal display element＞ The liquid crystal alignment film is a film obtained by coating the above-mentioned liquid crystal alignment agent on a substrate, drying and firing. As the substrate to which the liquid crystal alignment agent is applied, it is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as glass substrates, silicon nitride substrates, acrylic substrates, or polycarbonate substrates can be used. At this time, if a substrate formed of an ITO electrode or the like that can drive liquid crystal is used, it is preferable from the viewpoint of simplification of the manufacturing process. In addition, in reflective liquid crystal display elements, not only single-sided substrates, but also opaque materials such as silicon wafers may be used. In this case, materials that reflect light such as aluminum may also be used for the electrodes.

The method of coating the substrate of the liquid crystal alignment agent is not particularly limited, but in industry, methods such as screen printing, offset printing, flexographic printing, or inkjet methods are generally used. As other coating methods, there are a dipping method, a roll coating method, a slit coating method, a spinner method, a spray method, etc., which can be used according to the purpose.

After the liquid crystal alignment agent is coated on the substrate, the solvent can be evaporated to form a liquid crystal alignment film by heating means such as a heating plate, a thermal cycle oven or an IR (infrared) oven. Any temperature and time can be selected for the drying and firing steps after coating the liquid crystal alignment agent. Generally, when it is desired to sufficiently remove the contained solvent, after firing at 50 to 120°C for 1 to 10 minutes, conditions for firing at 150 to 300°C for 5 to 120 minutes can be mentioned. If the thickness of the fired liquid crystal alignment film is too thin, the reliability of the liquid crystal display element may be reduced, so it is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

The method of aligning the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention can be a rubbing treatment method, but it is better to use a photo-alignment treatment method. When the alignment treatment is performed by rubbing treatment or photo-alignment treatment, if you want to improve the alignment of the liquid crystal, it is better to perform the alignment treatment after the heating treatment at a temperature of 150-250℃ as appropriate, and the liquid crystal alignment film can also be coated. The substrate is subjected to alignment processing while being heated at 50 to 250°C.

Furthermore, in the aforementioned method, water or a solvent can also be used for the alignment-treated liquid crystal alignment film, and the contact treatment can be performed to remove impurities attached to the liquid crystal alignment film. Although there are no particular limitations on the solvent used in the above-mentioned contact treatment, specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, and 1-methoxy-2-propanol. , 1-Methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate , Propyl acetate, butyl acetate or cyclohexyl acetate etc.

The liquid crystal alignment film of the present invention can be suitably used as a liquid crystal alignment film of a liquid crystal display element of a lateral electric field mode such as an IPS mode or an FFS mode, and is particularly useful as a liquid crystal alignment film of a liquid crystal display element of the FFS mode. After the liquid crystal display element obtains a substrate with a liquid crystal alignment film from the liquid crystal alignment agent of the present invention, the liquid crystal cell can be used after a liquid crystal cell is fabricated by a known method.

As an example of the manufacturing method of the liquid crystal cell, a passive matrix structure liquid crystal display element can be taken as an example. It may also be a liquid crystal display element of an active matrix structure in which switching elements such as TFT (Thin Film Transistor) are provided in each pixel portion constituting the image display. Specifically, a transparent glass substrate is prepared, and ordinary electrodes are provided on one substrate, and segment electrodes are provided on the other substrate. These electrodes can be used as ITO electrodes, for example, and can be drawn into a desired image display. Secondly, an insulating film is provided on each substrate to cover the common electrode and the segmented electrode. The insulating film may be, for example, a SiO ₂ -TiO ₂ film formed by a sol-gel method.

Next, a liquid crystal alignment film is formed on each substrate, and the other substrate is superimposed on one substrate so that the liquid crystal alignment film faces face each other, and the periphery is bonded with a sealant. In order to control the substrate gap, spacers can usually be mixed in the sealant, and it is better to spread spacers for substrate gap control in the in-plane portion where the sealant is not provided. A part of the sealant is provided with an opening that can be filled with liquid crystal from the outside. Next, through the opening provided in the sealant, the liquid crystal material is injected into the space surrounded by the two substrates and the sealant, and then the opening is sealed with an adhesive. The injection can use a vacuum injection method, or a method using capillary phenomenon in the atmosphere. The liquid crystal material can be either a positive type liquid crystal material or a negative type liquid crystal material, preferably a negative type liquid crystal material. Next, set up the polarizer. Specifically, a pair of polarizing plates are bonded to the reverse surfaces of the liquid crystal layers of the two substrates. As described above, by using the liquid crystal alignment agent of the present invention, it is possible to obtain a liquid crystal alignment film with less residual DC or AC residual images, easy rework, and high transmittance. [Example]

Examples are given below to describe the present invention more specifically, but the present invention is not limited to these. The abbreviations of the compounds below and the methods for measuring their properties are as follows. (Diamine) l-1, n-1, DA-1～DA-7: each is a compound represented by the following formula (l-1), (n-1), (DA-1)～(DA-7) (Tetracarboxylic dianhydride) CA-1～CA-5: Each is a compound represented by the following formula (CA-1)～(CA-5) (Compound C) C-1: Compound represented by the following formula (C-1) (Compound D) D-1: Compound represented by the following formula (D-1) (Compound E) E-1: Compound represented by the following formula (E-1) (Organic solvents) NMP: N-methyl-2-pyrrolidone, GBL: γ-butyrolactone, BCS: butyl cellosolve, BCA: butyl cellosolve acetate

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

＜Determination of imidization rate＞ Put 20 mg of polyimide powder into an NMR sample tube (NMR sample tube standard, φ5 (manufactured by Kusano Science Co.)), and add deuterated dimethyl sulfide (DMSO-d6, 0.05% TMS (tetramethyl silane) ) Mixed product) (0.53ml), completely dissolved by ultrasound. This solution was measured for 500 MHz proton NMR using an NMR measuring machine (JNW-ECA500) (manufactured by JEDI). The rate of imidization depends on the proton derived from the structure unchanged before and after imidization as the reference proton, and the integral value of the absorption peak of the proton is used, and the NH derived from the imidic acid appearing near 9.5 ppm to 10.0 ppm The integral value of the proton absorption peak of the radical is obtained by the following formula. The imidization rate (%)=(1-α･x/y)×100 For the above formula, x is the integrated value of the proton absorption peak derived from the NH group of the amino acid, y is the integrated value of the absorption peak of the reference proton, and α is for 1 polyamide acid (the imidization rate is 0%) The ratio of the number of reference protons of the NH protons of amide acid.

[Synthesis of Polymers] ＜Synthesis example 1＞ In a 1L four-necked flask with a stirring device and a nitrogen tube, weigh out DA-2 (46.35g, 189.8mmol), DA-4 (28.81g, 51.75mmol), DA-3 (41.25g, 103.5mmol), Add NMP until the solid content becomes 15%, and stir to dissolve it while feeding nitrogen. CA-1 (50.27 g, 224.3 mmol) was added while stirring this diamine solution under water cooling, and NMP was further added until the solid content concentration became 18%, and stirring was performed for 1 hour at 40°C under a nitrogen environment. Thereafter, CA-3 (14.21 g, 72.5 mmol) was added while stirring under water cooling, and NMP was further added until the solid content concentration became 18%, and the mixture was stirred for 2 hours at 23° C. under a nitrogen environment to obtain a polyamide acid solution . In a 3L Erlenmeyer flask with a stir bar, put 1000.0g of the polyamide acid solution obtained above, add NMP (500.0g), acetic anhydride (105.99g), pyridine (27.37g), and proceed at room temperature for 30 After stirring for minutes, the reaction was carried out at 50°C for 2 hours. The reaction solution was poured into 6500 g of methanol, and the resulting precipitate was separated by filtration. After washing the precipitate with methanol, it was dried under reduced pressure at a temperature of 80°C to obtain a polyimide powder. The polyimide powder has an imidization rate of 75%. Put the polyimide powder (100.00g) in a 1000mL Erlenmeyer flask with a stir bar, add NMP (400.0g), stir at 70°C for 24 hours to dissolve and obtain a solid content concentration of 20 % Of polyimide (PI-A-1) solution.

＜Synthesis example 2＞ As shown in Table 1 below, using a diamine, a tetracarboxylic acid derivative, and an organic solvent, each was implemented in the same procedure as in Synthesis Example 1, and a polyamide acid having the composition shown in Table 1 below was obtained. 1000.0 g of the polyamide acid solution thus obtained was taken out, compound E-1 (45.32 g, 207.63 mmol) was put in and stirred for 12 hours, and NMP, acetic anhydride and pyridine were used in the same manner as in Synthesis Example 1 to obtain polyamide A solution of amine (PI-A-2). In Table 1, the values in parentheses indicate the compounding ratio (mole parts) of each compound for the total amount of 100 mol parts of diamine used in the synthesis for the tetracarboxylic acid component, and for the diamine component, It shows the compounding ratio (mole part) of each compound with respect to the total amount of 100 mol parts of the diamine used for synthesis. For the organic solvent, the blending ratio (parts by weight) of each organic solvent to 100 parts by weight of the total amount of the organic solvents used in the synthesis.

＜Synthesis example 3＞ In a 1L four-necked flask with a stirring device and a nitrogen tube, weigh out DA-2 (24.12g, 98.8mmol), DA-1 (22.74g, 98.8mmol), and l-1 (42.12g, 197.5mmol), Add NMP (464.9g) and GBL (185.7g) to a solid content concentration of 12%, and stir to dissolve it while feeding nitrogen. While stirring the diamine solution under water cooling, CA-3 (50.0 g, 255.0 mmol) of the aliphatic dianhydride and GBL (237.7 g) were added at the same time to achieve a solid content concentration of 13.5%, under a nitrogen environment Stirring was carried out for 2 hours under water cooling. Furthermore, CA-5 (25.84g, 118.5 mmol) of aromatic acid dianhydride was added, and GBL was added to a solid content of 15%, and stirring was carried out at 50°C for 15 hours under a nitrogen environment to obtain NMP with a solid content of 15%. /GBL=50/50 Polyamide acid (PAA-B-1) solution.

＜Synthesis example 4～10＞ As shown in Table 1 below, using diamine, tetracarboxylic acid derivatives, and organic solvents, each was carried out under the same procedures as in Synthesis Example 3 to obtain polyamide acid (PAA-B-2) shown in Table 1 below. ~(PAA-B-8) solution. In Table 1, the values in parentheses indicate the alignment ratio (mole parts) of each compound when the total amount of diamine used in the synthesis is 100 parts by mole for the tetracarboxylic acid component, and for the diamine component, The compounding ratio (mole part) of each compound when the total amount of the diamine used in the synthesis is 100 mol parts. The organic solvent means the blending ratio (parts by weight) of each organic solvent to 100 parts by weight of the total amount of organic solvents used in the synthesis.

<Example 1> [Modulation of liquid crystal alignment agent] Use the polyimide (PI-A-1) solution obtained in Synthesis Example 1 and the polyimide acid (PAA-B-1) solution obtained in Synthesis Example 3, and dilute with NMP, GBL and BCS Add compound (C-1) to 3 parts by weight for 100 parts by weight of the total polymer, and add compound (D-1) to 1 part by weight for 100 parts by weight of the total polymer, and stir at room temperature. Next, by filtering the resulting solution with a filter with a pore size of 0.5 μm, the composition ratio of the polymer is obtained as (PI-A-1): (PAA-B-1)=20:80 (solid content conversion weight ratio ), the solvent composition ratio is solid content: NMP:GBL:BCS=4.5:30:45.5:20 (weight ratio), the mixing ratio of compound (C-1) and compound (D-1) each becomes solid content ratio 3 weight Parts and 1 part by weight of the liquid crystal alignment agent (1) (Table 2 below). It was confirmed that no abnormal phenomena such as turbidity or precipitation were seen in the liquid crystal alignment agent, and a uniform solution was obtained.

<Examples 2 to 11, Comparative Examples 1 to 4> Except for using the polymer, compound (C), and compound (D) in Table 2 below, the same procedure as in Example 1 was performed to obtain liquid crystal alignment agents (2) to (15). In Table 2, the values in parentheses indicate that for the total 100 parts by weight of the polymer and compound (C) and compound (D) used in the preparation of each liquid crystal alignment agent, each polymer component or compound (C) The mixing ratio (parts by weight) of the compound (D). The organic solvent means the mixing ratio (parts by weight) of each organic solvent to 100 parts by weight of the total amount of the organic solvents used in the preparation of the liquid crystal alignment agent.

[Production of liquid crystal display element] A liquid crystal cell composed of a Fringe Field Switching (FFS) mode liquid crystal display element was produced. First prepare a substrate with electrodes. The substrate is a glass substrate with a size of 30mm×50mm and a thickness of 0.7mm. An ITO electrode having a flat pattern pattern as a first layer constituting a counter electrode is formed on the substrate. As the second layer on the counter electrode of the first layer, a SiN (silicon nitride) film formed by the CVD method is formed. The SiN film of the second layer has a thickness of 500 nm and functions as an interlayer insulating film. On the SiN film of the second layer, comb-shaped pixel electrodes formed by patterning an ITO film as the third layer are arranged to form two types of pixels, the first pixel and the second pixel. The size of each pixel is 10mm in length and 5mm in width. At this time, the so-called counter electrode of the first layer and the pixel electrode of the third layer mean that the SiN film of the second layer is electrically insulated.

The pixel electrode of the third layer has a comb-tooth shape in which electrode elements bent into a "く" shape at the center are arranged in plural. The width of each electrode element in the lateral direction is 3 μm, and the interval between the electrode elements is 6 μm. The pixel electrode forming each pixel is composed of plural arrays of electrode elements whose central part is bent into a zigzag shape. Therefore, the shape of each pixel is not a rectangular shape. Like the electrode elements, the central part has a curved shape. A bold shape similar to "く". Then, each pixel system divides the central curved part into upper and lower regions as a boundary, and has a first region above the curved part and a second region below the curved part.

When 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 a reference, in the first area of the pixel, the electrode element of the pixel electrode is formed at an angle of +10˚ (clockwise), and in the second area of the pixel, The electrode element of the pixel electrode is formed at an angle of -10˚ (clockwise). That is, in the first area and the second area of each pixel, the liquid crystal rotates in the surface of the substrate (face-to-face switching) due to the input voltage between the pixel electrode and the counter electrode, so that the mutual direction becomes Constructed in the opposite direction.

Next, after filtering the liquid crystal alignment agent with a filter with a pore size of 1.0 μm, spin-coated the prepared substrate with electrodes and the glass substrate with columnar spacers with a height of 4 μm formed as an ITO film. Coating performs coating. After drying for 5 minutes on a hot plate at 80°C, it was fired in a hot air circulation oven at 230°C for 20 minutes to obtain a polyimide film with a film thickness of 60 nm. Rub the polyimide film with rayon cloth (roll diameter: 120mm, roll rotation number: 500rpm, moving speed: 30mm/sec, push-in length: 0.3mm, rubbing direction: inclined to 3-layer IZO comb electrode After 10˚ direction), it is washed by ultrasonic irradiation in pure water for 1 minute, and the water droplets are removed by blowing. Thereafter, drying was performed at 80°C for 15 minutes to obtain a substrate with a liquid crystal alignment film. Take these two substrates with the liquid crystal alignment film as a set, apply (print) the sealant under the shape of the liquid crystal injection port on the substrate, paste the other substrate to face the liquid crystal alignment film surface, and rub The direction becomes anti-parallel. After that, the sealant was hardened to produce cells with a cell gap of 4 μm. A liquid crystal MLC-3019 (manufactured by Merck & Co.) was injected by performing a reduced-pressure injection method on the hollow cell, and the injection port was sealed to obtain an FFS type liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 120° C. for 1 hour, and then left at 23° C. for one night, and then used for the evaluation of liquid crystal alignment.

[Assessment] 1. After-image evaluation driven by long-term communication Prepare a liquid crystal cell with the same structure as the liquid crystal cell used for the afterimage evaluation. With the liquid crystal cell placed on a high-brightness backlight, an AC voltage of ±5V with a frequency of 60 Hz was input for 168 hours. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and they were left at room temperature for one day. After placement, the liquid crystal cell is placed between the two polarizing plates perpendicular to the polarization axis, the backlight is turned on with no voltage input, and the arrangement angle of the liquid crystal cell is adjusted to minimize the brightness of the transmitted light. Then, from the angle at which the second area of the first pixel becomes the darkest, when the liquid crystal cell is rotated to the angle at which the first area becomes the darkest, the rotation angle is calculated as the angle Δ. The same applies to the second pixel, and the same angle Δ is calculated by comparing the second area and the first area. When the angle Δ is less than 0.15˚, it indicates good liquid crystal alignment. The evaluation results are shown in Table 3.

2. Measurement of the relaxation speed of accumulated charge The liquid crystal cell produced in the same way as the above (Production of liquid crystal cell) is placed between two polarizing plates whose polarization axes are arranged at right angles, and the pixel electrode and the counter electrode are short-circuited at the same potential. The LED backlight is irradiated from below the two polarizing plates, and on the top of the two polarizing plates, the angle of the liquid crystal cell is adjusted to minimize the measured brightness of the LED backlight transmitted light. Next, the V-T curve (voltage-transmittance curve) was measured while inputting an AC voltage of 60 Hz into the liquid crystal cell, and the AC voltage at which the relative transmittance became 23% was calculated as the driving voltage. In the after-image evaluation, the liquid crystal cell was driven while the relative transmittance was 23% and an AC voltage with a frequency of 60Hz was input, and a DC voltage of 1V was input at the same time for 120 minutes. After that, only the input of the DC voltage was stopped, and only the AC voltage was used for further 15 minutes of driving. From the time point when the input of DC voltage is stopped, after 10 minutes, if the relative transmittance is reduced to 25% or less, the evaluation is defined as "good". If the relative transmittance is reduced to 26% or less, it takes more than 10 minutes to evaluate. Defined as "bad". Then, the after-image evaluation according to the above-mentioned method was performed under the temperature condition where the temperature of the liquid crystal cell was 40°C.

3. Black level assessment The liquid crystal cell manufactured in the same way as the above (fabrication of liquid crystal cell) is placed between two polarizing plates whose polarization axis is arranged at right angles, and the backlight is turned on with no voltage input, and the arrangement angle of the liquid crystal cell is adjusted to The brightness of the transmitted light becomes the minimum. The LCD unit was observed using a Digital CCD camera "C8800-21C" manufactured by Hamamatsu Photonics, and the captured image was quantified by using the analysis software "ExDcam Image capture Software" of the same company. If the brightness value of the liquid crystal cell is 580 or less, it is evaluated as "good", and those above this are evaluated as "bad".

4. Evaluation of Heavy Workability The liquid crystal alignment agent of the present invention is coated on the ITO substrate by spin coating. After drying for 1 minute and 30 seconds on a hot plate at 60°C, it was fired in a hot air circulating oven at 230°C for 20 minutes to form a coating film with a thickness of 100 nm. Thereafter, a substrate made of a heavy-duty material (KR-31) heated to 35°C was immersed for 600 seconds to develop an image, and then washed with ultrapure water for 30 seconds in running water. After drying by blowing air, observe the residual film amount. At this time, the condition with residual film was evaluated as "good", and the condition with residual film as "bad".

[產業上可利用性]Table 3 shows the results of the above-mentioned experiments 1 to 4.

[Industrial availability]

The liquid crystal alignment agent of the present invention is useful for the formation of a liquid crystal alignment film in a wide range of liquid crystal display elements such as an IPS driving method or an FFS driving method. In addition, all the contents of the specification, application scope, drawings, and abstract of Japanese patent application No. 2019-023807 filed on February 13, 2019 and Japanese patent application No. 2019-082233 filed on April 23, 2019 All are quoted here as the disclosure content of the specification of the present invention.

Claims (13)

A liquid crystal alignment agent characterized by containing the following (A) component and (B) component; (A) component: polymer (A) having a repeating unit represented by the following formula (1); (B) component: Having a repeating unit represented by the following formula (2), a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5), the following formula (2) The total content of the repeating unit shown and the repeating unit shown in the following formula (3) is 60 to 99.9 mol% of the total repeating unit, and the repeating unit shown in the following formula (4) and the following formula (5) are Show the polymer (B) whose total content of repeating units is 0.1-40 mol% of all repeating units;

(X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group)

(X ₂ is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride; Y ₂ is a divalent organic group represented by the following formula (m-1) or (m-2); R ₂ is A hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Z ₂₁ and Z _{22 are} each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, and an optionally substituted alkenyl group having 2 to 10 carbon atoms Group, optionally substituted alkynyl group with 2-10 carbons, tert-butoxycarbonyl, or 9-fluorenylmethoxycarbonyl)

(* indicates the bond hand)

(X ₃ is a tetravalent organic group derived from alicyclic acid dianhydride or aliphatic acid dianhydride; Y ₃ is a divalent organic group represented by the following formula (l), or has a part represented by the following formula (n) The structure of the bivalent organic group; R ₃ is a hydrogen atom, or an alkyl group having 1 to 4 carbons; Z ₃₁ and Z _{32 are} each independently a hydrogen atom, and an optionally substituted alkyl group having 1 to 10 carbons may have Substituent C 2-10 alkenyl, optionally substituted C 2-10 alkynyl, tert-butoxycarbonyl, or 9-fluorenylmethoxycarbonyl);

(Q ¹ and Q ² are alkyl groups with 1 to 3 carbons, and Q ³ is a hydrogen atom or alkyl groups with 1 to 3 carbons; * means bonding hands)

(X _4, X ₅ is a tetravalent organic radical derived from an aromatic dianhydride; the Y ₄ in the formula (2) is synonymous with Y _2, R ₂ is synonymous with R ₄ in the formula (2); Z _41, Z ₄₂ each and, Z ₂₂ synonymous Z ₂₁ in the formula (2); _{Y. 5} and Y in the formula (3) synonymous _3, R ₅ and R in the formula (3) synonymous _3, Z _51, Z ₅₂ each of the aforementioned formula ( 3) Z ₃₁ and Z _{32 are} synonymous). The liquid crystal alignment agent of claim 1, wherein in the aforementioned polymer (B), as the repeating unit represented by the formula (3), Y ₃ is a repeating unit of the divalent organic group represented by the aforementioned formula (1), and Y ₃ It is a repeating unit of a divalent organic group having a partial structure represented by the aforementioned formula (n). The liquid crystal alignment agent of claim 1 or 2, wherein the divalent organic group having the partial structure represented by the aforementioned formula (n) is a divalent organic group represented by any one of the following formulas (n-1) to (n-3) base;

(Q ^2, Q ³ each of the aforementioned formula (n), Q ^2, Q ³ synonymous; Q ⁴ represents a single bond or a structure of the following formula (Ar) of; n is an integer of 1 to 3; * represents a bonding hand)

(Q ⁵ is a divalent selected from single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONQ-, and -NQCO- Organic group, k is an integer of 1 to 5; and, Q represents hydrogen or a monovalent organic group, l and m are integers of 1 to 5; *1, *2 represent bonding hands, * ₁ and formula (n-1 ) ~ The benzene ring in formula (n-3) is bonded). The liquid crystal alignment agent according to any one of claims 1 to 3, wherein Y ₁ of the aforementioned formula (1) is a divalent organic group having a partial structure represented by the following formula (H);

(Q ¹¹ is -NQCO-, -COO-, -OCO-, -NQCONQ-, -CONQ-, or -(CH ₂ ) _n- (n is an integer from 1 to 20); however, when n is 2 to 20 , Any -CH ₂ -can be substituted with -O-, -COO-, -OCO-, -ND-, -NQCO-, -CONQ-, -NQCONQ-, -NQCOO-, or-under the condition that each is not adjacent OCOO-; D represents a thermally detachable group, Q represents a hydrogen atom or a monovalent organic group; Q ¹² is a single bond or a benzene ring, any hydrogen atom on the benzene ring can be replaced by a monovalent organic group; *1, *2 represents Bonding hands, when Q ¹² is a single bond, *2 is bonded to the nitrogen atom in the amine group; when Q ¹² is a benzene ring, Q ¹¹ can be a single bond). The liquid crystal alignment agent according to any one of claims 1 to 4, wherein Y ₁ of the aforementioned formula (1) is a divalent structure having a partial structure shown in any one of the following formulas (H-1) to (H-14) Organic base

(*1, *2 represent bonding hands, *2 is bonded to the nitrogen atom in the imine ring). The liquid crystal alignment agent of any one of claims 1 to 5, wherein Y ₁ of the aforementioned formula (1) is a divalent organic group represented by any one of the aforementioned formulas (H-1) to (H-14), or The divalent organic group shown in any of the formulas (MH-1)～(MH-2);

(*1 It is bonded to the nitrogen atom in the imine ring; Boc represents tert-butoxycarbonyl). The liquid crystal alignment agent of any one of claims 1 to 6, wherein X ₁ of the aforementioned formula (1) is selected from the following formulas (4a) to (4l), the following formulas (5a) and the following formulas (6a) ) At least 1 species of the group;

(x and y are each independently a single bond, a carbonyl group, an ester, a phenylene group, a sulfonyl group, or an amido group; each of Z ¹ to Z ⁴ independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom, or benzene Ring; j is an integer of 0 or 1; m is an integer of 0 to 5; * represents a bonding hand). The liquid crystal alignment agent according to any one of claims 1 to 7, wherein the content ratio of the aforementioned polymer (A) to the aforementioned polymer (B) is 5 at the weight ratio of polymer (A)/polymer (B) /95～95/5. The liquid crystal alignment agent according to any one of claims 1 to 8, which further contains an oxirane group, an oxetanyl group, a protected isocyanate group, a protected isothiocyanate group, and an oxazoline Compounds containing at least one group of groups of cyclic structure groups, groups containing maltonic acid structure, cyclic carbonate groups, groups represented by the following formula (d), and groups containing partial structures represented by the following formula (e) (C);

(Q ₃₁ is a hydrogen atom, an alkyl group with 1 to 3 carbons or "*-CH ₂ -OH", Q ₃₂ and Q _{33 are} each independently a hydrogen atom, an alkyl group with 1 to 3 carbons or "*-CH ₂ -OH"; * represents a bonding hand; A represents an organic group having an aromatic ring (m+n) valence; m represents an integer of 1 to 6, and n represents an integer of 0 to 4). The liquid crystal alignment agent of claim 9, wherein the content of the aforementioned compound (C) is 0.5-20 parts by weight with respect to 100 parts by weight of the polymer component contained in the liquid crystal alignment agent. A liquid crystal alignment film characterized by being obtained from the liquid crystal alignment agent according to any one of claims 1 to 10. A liquid crystal display element characterized by having a liquid crystal alignment film as claimed in claim 11. Such as the liquid crystal display element of claim 12, which is driven by a lateral electric field.