TWI749019B - Liquid crystal alignment agent for coating BOA substrate or substrate with BCS and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal alignment agent for coating a BOA substrate or a BCS-attached substrate, and a liquid crystal display element provided with a BOA substrate or a BCS-attached substrate with good display quality obtained by using the liquid crystal alignment agent.

The BOA substrate or the liquid crystal alignment agent for substrate coating with BCS of the present invention contains a polyimide compound selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. A group of at least one type of polymer, the polyimide precursor is obtained by reacting a diamine component containing a diamine with a tetracarboxylic dianhydride component, and the diamine has a structure other than two amine groups It contains nitrogen or carboxylic acid groups; and, the liquid crystal display element of the present invention is provided with a BOA substrate or a substrate with BCS, and these substrates are formed with a liquid crystal alignment film obtained from the aforementioned liquid crystal alignment agent.

Description

Liquid crystal alignment agent and liquid crystal display element for BOA substrate or substrate coating with BCS

The present invention relates to a liquid crystal alignment agent for coating a BOA substrate or a BCS-attached substrate, and a liquid crystal display element provided with a BOA substrate or a BCS-attached substrate obtained by using the liquid crystal alignment agent.

Generally speaking, a liquid crystal display element includes an "array substrate" (which is formed with thin film transistors), and a "counter substrate" (which is opposed to the array substrate and formed with color filters), and includes sandwiched The "liquid crystal layer" between the array substrate and the counter substrate. For color filters, for the purpose of improving contrast or color development, the boundary between the red, green, and blue colored layers must have a black matrix. In recent years, due to manufacturing yields and other factors, a "color-filter array" (COA: Color-Filter On Array) with color filters formed on an array substrate or a "color-filter on array" (COA: Color-Filter On Array) formed on a COA substrate has been developed. "Black Matrix On Array" (BOA: Black Matrix On Array) substrate.

Furthermore, because of the manufacturing yield and other factors, attempts have been made to use a black colored resin composition as a material for supporting the column spacer between the array substrate and the counter substrate (such column spacers are also referred to as black column spacers). (BCS: Black Column Spacer)), the black colored resin composition may also use the aforementioned black matrix material.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2014-167492 A

[Patent Document 2] JP 2015-191234 A

In terms of its structure, the aforementioned BOA substrate is difficult to ensure the reliability of the liquid crystal display element when manufacturing the liquid crystal display element compared with the COA substrate, and may cause the display quality of the liquid crystal display element to be poor. Furthermore, by using a substrate with BCS, the above-mentioned problem becomes more obvious.

In view of the foregoing, the present invention provides a liquid crystal alignment agent for coating BOA substrates or substrates with BCS, and a BOA substrate or substrate with BCS with good display quality obtained by using the liquid crystal alignment agent Liquid crystal display element.

The inventors completed the present invention as a result of intensive research.

That is, the present invention has the following gist.

1. A liquid crystal alignment agent for coating a BOA substrate or a substrate with BCS, which is characterized by containing a polyimide selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor A group of at least one type of polymer, the polyimide precursor is obtained by reacting a diamine component containing a diamine with a tetracarboxylic dianhydride component, and the diamine is based on two amine groups The structure contains nitrogen or carboxylic acid groups.

(式中，Cy係二價基並以選自由氮雜環丁烷、吡咯啶、哌啶及六亞甲基亞胺所成之群之脂肪族雜環來表示，且取代基可與該等的環部分進行鍵結，R₁₄係氫原子、單鍵、羰基或＊-CONH-(但附有「＊」之鍵結部係與哌啶環進行鍵結)，R₁₅係表示氫或一價的有機基，R₁₈及R₁₉係分別獨立為氫原子或單鍵)。 2. The liquid crystal alignment agent of 1 above, wherein the diamine has a structure selected from at least one of the following formulae as a partial structure,

(In the formula, Cy is a divalent group and is represented by an aliphatic heterocyclic ring selected from the group consisting of azetidine, pyrrolidine, piperidine and hexamethyleneimine, and the substituent may be associated with these R ₁₄ is a hydrogen atom, a single bond, a carbonyl group or *-CONH- (but the bonding part with "*" is bonded to the piperidine ring), R ₁₅ is a hydrogen or a For the valence organic group, R ₁₈ and R ₁₉ are each independently a hydrogen atom or a single bond).

3. The liquid crystal alignment agent of 1 or 2, wherein the diamine is at least one diamine selected from the group consisting of diamines of the following formulas (1) to (9).

4. The liquid crystal alignment agent according to any one of 1 to 3 above, wherein the diamine component includes a diamine represented by the following formula (10) or (11).

5. The liquid crystal alignment agent of any one of 1 to 4 above, wherein the aforementioned tetracarboxylic dianhydride component is selected from at least one tetracarboxylic acid selected from the group consisting of the following formulas (12) to (14) Dianhydride.

6. The liquid crystal alignment agent of any one of 1 to 5 above, wherein the liquid crystal alignment agent contains a polymer other than the polyimide precursor, or contains the polyimide precursor. Polymers other than polyimide obtained by chemical conversion.

7. The liquid crystal alignment agent of any one of 1 to 6 above, wherein the aforementioned liquid crystal alignment agent further comprises a group selected from the group consisting of adhesion auxiliary agents, crosslinking agents, dielectrics, conductive substances and organic solvents At least one.

8. The liquid crystal alignment agent of 7 above, wherein the crosslinking agent is selected from at least one compound of formula (17), formula (19) and formula (21) described later.

9. The liquid crystal alignment agent of 8 above, wherein the crosslinking agent is selected from at least one compound selected from the group consisting of the following formulas CL-1 to CL-3.

10. A liquid crystal display element comprising a BOA substrate or a substrate with BCS, the substrates being formed with a liquid crystal alignment film obtained from the liquid crystal alignment agent of any one of 1 to 9 above.

11. A method for manufacturing a liquid crystal alignment film on a BOA substrate or a substrate with BCS, which is to apply the liquid crystal alignment agent of any one of 1 to 9 above to the BOA substrate.

12. A substrate for a liquid crystal display element, comprising: a BOA substrate or a substrate with BCS; and a liquid crystal alignment agent for coating the BOA substrate in any one of 1 to 9 above and on the BOA substrate or a substrate with BCS The liquid crystal alignment film formed on the substrate.

According to the present invention, a liquid crystal alignment agent for coating a BOA substrate or a BCS-attached substrate, and a liquid crystal display element having a BOA substrate or a BCS-attached substrate with good display quality obtained by using the liquid crystal alignment agent can be provided.

[Best form to implement the invention]

The liquid crystal alignment agent of the present invention is a liquid crystal alignment agent for coating BOA substrates or substrates with BCS, which contains a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor. At least one type of polymer (hereinafter also referred to as a specific polymer) of the group called imidine, the polyimide precursor is made of a diamine component containing a diamine (hereinafter also referred to as a specific diamine) and four It is obtained by reacting a carboxylic dianhydride component, and the diamine contains nitrogen or a carboxylic acid group in a structure other than two amino groups. In addition, the liquid crystal display element of the present invention is a liquid crystal display element, which is provided with a BOA substrate or a substrate with BCS, and these substrates are formed with a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention.

<Diamine containing nitrogen or carboxylic acid group in a structure other than 2 amino groups>

The so-called diamine containing nitrogen or carboxylic acid group in a structure other than two amine groups means that the structure of the diamine structure other than the structure where two amine groups are bonded has a structure selected from the following formulas The structure of at least one of the group is used as a partially structured diamine. The structure of the following formula is preferably monovalent or divalent, and can be bonded to a structure in which two amine groups are bonded at any position.

In the above structure, Cy is a divalent group and is a fat selected from the group consisting of azetidine, pyrrolidine, piperidine and hexamethyleneimine It is represented by a heterocyclic ring group, and a substituent may be bonded to these ring parts. R ₁₄ is a hydrogen atom, a single bond, a carbonyl group or *-CONH- (but the bonding part with "*" is bonded to the piperidine ring). R ₁₅ represents hydrogen or a monovalent organic group. R ₁₈ and R ₁₉ are each independently a hydrogen atom or a single bond.

Specifically, a liquid crystal display element is provided with a BOA substrate or a substrate with BCS, the substrates are formed with a liquid crystal alignment film obtained from the following liquid crystal alignment agent, the liquid crystal alignment agent is selected from polyamide An imine precursor and a polymer of at least one of the group of polyimine obtained by subjecting the polyimine precursor to imidization, the polyimine precursor is selected from the group consisting of The diamine component of at least one of the diamines represented by the formula (1) to the following formula (9) (hereinafter also referred to as specific diamines 1 to 9) and the tetracarboxylic dianhydride component are obtained by reacting .

<Specific Diamine 1>

The specific diamine 1 used in the present invention is a diamine represented by the following formula (1).

In formula (1), X ¹ is a single bond, -O- _{, -CO-, -NH-, -N(CH 3} )-, -CONH-, -NHCO-, -CH ₂ O-, -OCO-, -CON(CH ₃ )- or N(CH ₃ )CO-. Among them, -O-, -COO-, -NH-, -CONH-, -NHCO-, -CON(CH ₃ )-, -CH ₂ O- or OCO- are preferred because they are easy to synthesize diamines. Particularly preferred are -O-, -CO-, -NH-, -CONH-, -NHCO-, -CON(CH ₃ )- or CH ₂ O-.

啶環或咪唑啶環。特別是非芳香族雜環為5員環或6員環者，作為液晶配向膜時因為可得到良好的配向性故為較佳。又，非芳香族雜環為含有2個氮原子之情形時，作為液晶顯示元件時，因位於液晶配向膜界面會吸附液晶中的離子性雜質，從而維持液晶顯示元件之良好的電特性故為宜。 X ² is an alkyl group with 1 to 5 carbon atoms or a non-aromatic heterocyclic ring containing a nitrogen atom. When X ² is an alkyl group having 1 to 5 carbon atoms, the alkyl group may be linear or branched. In particular, the number of carbon atoms in the alkyl group is preferably 1 to 3. In addition, ^{examples of the case where X 2} is a non-aromatic heterocyclic ring containing a nitrogen atom include a pyrrolidine ring, a piperidine ring, a piperazine ring, a pyrazole ring,

Pyridine ring or imidazole ring. In particular, a non-aromatic heterocyclic ring having a 5-membered ring or a 6-membered ring is preferred as a liquid crystal alignment film because good alignment can be obtained. In addition, when the non-aromatic heterocyclic ring contains two nitrogen atoms, when used as a liquid crystal display element, ionic impurities in the liquid crystal will be adsorbed at the interface of the liquid crystal alignment film to maintain the good electrical characteristics of the liquid crystal display element. should.

From the above point of view, as a non-aromatic heterocyclic ring containing a nitrogen atom, a piperazine ring is particularly preferred. In addition, when X ^{2 is} bonded to a nitrogen atom in X ³ or a carbon atom adjacent to the nitrogen atom, when forming a liquid crystal display element, the effect of accelerating the relaxation of the residual charge accumulated by the direct current voltage is excellent, so it is preferable.

環。其中，以吡啶環、咪唑環、吡嗪環或嘧啶環為較佳。進而，X³中之芳香族雜環若被烷基所取代之情形時，該烷基的碳數以1~3為較佳。 X ³ is a 5-membered ring or 6-membered aromatic heterocyclic ring containing 1 or 2 nitrogen atoms, and can be substituted by an alkyl group with 1 to 5 carbon atoms. Examples of 5-membered or 6-membered aromatic heterocyclic rings containing 1 or 2 nitrogen atoms include pyridine ring, imidazole ring, pyrazole ring, pyrazine ring, pyrimidine ring or pyridine ring.

ring. Among them, a pyridine ring, an imidazole ring, a pyrazine ring or a pyrimidine ring is preferred. Furthermore, ^{when the aromatic heterocyclic ring in X 3} is substituted by an alkyl group, the carbon number of the alkyl group is preferably 1 to 3.

n is an integer from 1 to 4. Among them, an integer of 1 or 2 is preferred.

Specifically, the following compounds can be exemplified, but they are not limited to them.

<Specific Diamine 2>

The specific diamine 2 used in the present invention is a diamine represented by formula (2).

In the formula (2), X ₁ is an organic group having an aromatic ring with 6 to 30 carbon atoms. n is an integer from 1 to 4. As a preferred example of the diamine ester represented by the formula (2), the following formulas (2-1) to (2-5) can be given.

In formula (2-1), m1 is an integer of 1 to 4. In the formula (2-2), X ₂ is a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) ₂ -,- O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, -CON(CH ₃ )-or -N(CH ₃ )CO-. m2 and m3 represent integers from 0 to 4, respectively, and m2+m3 represent integers from 1 to 4. In formula (2-3), m4 and m5 represent integers of 1 to 5, respectively. In the formula (2-4), X ₃ is a linear or branched alkyl group having 1 to 5 carbon atoms. m6 is an integer from 1 to 5. In formula (2-5), X ₄ is a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) ₂ -,- O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, -CON(CH ₃ )-or -N(CH ₃ )CO-. m7 is an integer from 1 to 4.

In formula (2-1), m1 is preferably an integer of 1-2. In formula (2-2), X ₂ is preferably a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -COO- or -OCO-, m2 and m3 are both integers of 1. In formula (2-5), X ₄ is preferably a single bond, -CH ₂ -, -O-, -CO-, -NH-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO-, m7 is an integer of 1~2. Among them, the diamine represented by the formula (2-1) is particularly preferred.

Specific examples of the diamine ester represented by the formula (2) include the following formulas (2-6) to (2-16).

In formula (2-15), X ₅ is a single bond, -CH ₂ -, -O-, -CO-, -NH-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO-. In formula (2-16), X ₆ is a single bond, -CH ₂ -, -O-, -CO-, -NH-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO-.

<Specific Diamine 3>

The specific diamine 3 used in the present invention is a diamine represented by the following formula (3).

Q ₁ represents an alkylene group having 1 to 5 carbon atoms, and it is preferably a linear alkylene group having 1 to 5 carbon atoms in terms of the ease of synthesis.

Cy is a divalent group and is represented by an aliphatic heterocyclic ring selected from the group consisting of azetidine, pyrrolidine, piperidine, and hexamethyleneimine. In terms of ease of synthesis, azetidine, pyrrolidine or piperidine is preferred. In addition, the substituent may be bonded to these ring moieties.

Q ₂ represents the structure of the following formula (3-I) or (3-II). The *1 in the formula (3-I) or (3-II) represents the bond _{with Q 1.} *2 is the bond with the benzene ring. _{R 1} in the formula (3-II) represents hydrogen or a monovalent organic group, preferably a hydrogen atom or a linear alkyl group having 1 to 3 carbons, and more preferably a hydrogen atom or a methyl group.

R ₂ and R ₃ are monovalent organic groups. q and r are each independently an integer of 0-4. However, when the total of q or r is 2 or more, R ₂ and R ₃ are independent of each other. In terms of ease of synthesis, R ₂ and R _{3 are} preferably methyl groups. In addition, the bonding position of the amine group in the benzene ring constituting the above-mentioned diamine is not limited, and the amine group is located at the 3-position or 4-position with respect to the nitrogen atom on Cy, and is bonded to Q ₁ and R _{1 respectively} . The nitrogen atom is preferably at the 3 or 4 position; it is better to use the 4 position relative to the nitrogen atom on Cy and the 4 position relative to the nitrogen atom bonded to Q ₁ and R ₁ good.

The diamine represented by the above formula (3) of the present invention is preferably the following formula (3-1) or (3-2).

In the formula, R ₁₆ is a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group (hereinafter also referred to as a Boc group). R ₁₇ is a hydrogen atom or a methyl group. Q ₁ is a linear alkylene group having 1 to 5 carbon atoms.

As a specific example represented by the above formula (3-1), for example, the following formulas (3-1-1) to (3-1-10) can be given. As a specific example represented by the above formula (3-2), For example, the following formulas (3-2-1) to (3-2-4) are given.

<Specific Diamine 4~7>

The specific diamines 4 to 7 used in the present invention are diamines represented by the following formulas (4) to (7) in which the amine group is protected by a Boc group.

In formula (4), D represents a divalent saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring having 1 to 20 carbon atoms, and D may have various substituents. m is 1 or 0.

The substitution position of the amine group in the above formula (4) is not particularly limited, but from the viewpoint of ease of synthesis or availability of reagents, when the amide bond is used as a reference, the position of meta or para is taken as Preferably, from the viewpoint of liquid crystal orientation, the alignment position is particularly preferred. In addition, even if it is an aminobenzene that does not have an amine group protected by a Boc group (i.e. -NHBoc), when the amide bond is used as the reference, the meta or para position is preferred, and the solubility is From the standpoint of view, the position of meta is preferable, and from the standpoint of liquid crystal orientation, the position of alignment is preferable. In addition, the hydrogen system of amine benzene that does not have -NHBoc may be substituted with an organic group or a halogen atom such as fluorine.

D in the formula (4) is not limited, and various structures can be selected according to the structure using dicarboxylic acid or tetracarboxylic dianhydride as a raw material. As D, from the viewpoint of solubility, a divalent hydrocarbon group or the like is preferred, and a straight-chain alkylene group or a cyclic alkylene group can be cited as preferred examples. The hydrocarbon group may have an unsaturated bond. Knot. In addition, from the viewpoint of liquid crystal alignment or electrical characteristics, a divalent aromatic hydrocarbon group, a heterocyclic ring, or the like is preferable. From the viewpoint of liquid crystal alignment, it is preferable that D does not have a substituent, but from the viewpoint of solubility, it is preferable that the hydrogen atom is substituted by a carboxylic acid group, a fluorine atom, or the like.

In the formula (5), E is a single bond or a divalent saturated hydrocarbon group, unsaturated hydrocarbon group, aromatic hydrocarbon group, or heterocyclic ring having 1 to 20 carbon atoms. The F series represents a single bond, -O-, -OCO- or -COO-.

The diamine when m in formula (4) is 0 or the diamine represented by formula (5) is a diamine with an asymmetric structure, but the preferred D is the same as the above, and the preferred E is also the same as the above The preferred D is the same. Furthermore, with regard to the diamine represented by the formula (5), a compound in which E and F are both single bonds is preferred.

In the formula (6), A ₁ based single bond, selected from the group consisting of ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O- and -OCO- formed by at least one of the groups Kind of divalent organic group or C1-C3 alkylene group. Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ₁₆ is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms.

In formula (7), X ⁴ and X ⁸ are each independently a single bond, -CH ₂ -or -CH ₂ CH ₂ -. X ⁵ and X ⁷ are each independently -CH ₂ -or -CH ₂ CH ₂ -. X ⁶ is an alkylene or cyclohexylene having 1 to 6 carbon atoms. Y ¹ is a single bond, -O-, -NH-, -N(CH ₃ )-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C (=O)N(CH ₃ )-, -OC(=O)-, -NHC(=O)- or -N(CH ₃ )C(=O)-. R ₁₇ is each independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, benzyl or 9-phenylene. a is 0 or 1.

As specific examples of the diamine represented by the above formulas (4) to (7), for example, formulas selected from the group consisting of the following formulas can be given.

<Specific Diamine 8>

The specific diamine 8 used in the present invention is a diamine represented by the following formula (8).

(In formula (8), R ₈ is a hydrogen atom, an alkyl group with 1 to 6 carbons, an aromatic group with 6 to 20 carbons, an aralkyl group with 7 to 13 carbons, or 1,3-dioxobutane Base (1,3-dioxobutyl).

Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, 2-butyl, i-butyl, or t-butyl.

Examples of the aromatic group having 6 to 20 carbons include aryl groups having 6 to 12 carbons or other aromatic groups. Examples of the aryl group having 6 to 12 carbon atoms include phenyl, 3-fluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 4-i-propylphenyl, 4-n-butyl Phenyl or 3-chloro-4-methylphenyl, etc. As the aforementioned other aromatic group, for example, 4-imidyl, 2-phenyl-4-quinolinyl, 2-(4'-t-butylphenyl)-4-quinolinyl or 2-( 2'-phenylthio)-4-quinolinyl and the like.

As a C7-13 aralkyl group, a benzyl group etc. are mentioned, for example.

X ¹¹ is a single bond, a carbonyl group or *-CONH- (but the bonding part with "*" is bonded to the piperidine ring).

R ₆ , R ₇ , R ₉ and R ₁₀ are each an alkyl group having 1 to 6 carbons, an aryl group having 6 to 12 carbons, or an aralkyl group having 7 to 13 carbons. However, the benzene ring possessed by the aforementioned aryl group and aralkyl group may be substituted with a formyl group or an alkoxy group having 1 to 4 carbon atoms.

Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, 2-butyl, i-butyl or t-butyl; As the aryl group having 6 to 12 carbons (but the benzene ring of the aryl group may be substituted with a formyl group or an alkoxy group having 1 to 4 carbons), for example, phenyl, 4-formylbenzene Group or 3,4,5-trimethoxyphenyl, etc.; as an aralkyl group with 7 to 13 carbons (but the benzene ring with this aralkyl group can be (Substituted), for example, benzyl and the like.

X ⁹ , X ¹⁰ , X ¹² and X ¹³ are single bonds, carbonyl groups, *-CH ₂ -CO- or *-CH ₂ -CH(OH)- (but the bonding part with "*" and The piperidine ring is bonded).

X ¹⁴ system oxygen atom, *-OCO-, the following formula (X ¹⁴ -1)

(In the formula, a is an integer from 1 to 12, and b is an integer from 0 to 5)

The indicated group (but the bonding part with "*" above is bonded to the piperidine ring), methylene group or alkylene group having 2-6 carbon atoms.

Examples of the alkylene group having 2 to 6 carbon atoms include 1,3-propylene group and 1,6-hexylene group.

2 above with an amine of formula (8) is bonded to the benzene ring, with respect to the group X ⁴ in the 2,4- or 3,5-position is preferred.

Preferred specific examples of the diamine represented by the formula (8) include the following formulas (8-1) to (8-4).

<Specific Diamine 9>

The specific diamine 9 used in the present invention is a diamine represented by the above formula (9).

R ₁₁ represents hydrogen or a monovalent organic group. Examples of the monovalent organic group include an alkyl group or alkenyl group having 1 to 10 carbon atoms, an alkoxy group, a cyano group, a hydroxyl group, a fluoroalkyl group, a trifluoroalkoxy group, a fluorine atom, and combinations thereof. The base of the group etc. Preferably, it is a hydrogen atom or a methyl group.

R ₁₂ each independently represents a single bond or the structure of the following formula (9-2). In addition, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group.

R ₁₃ represents a single bond, selected from the group consisting of -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO- A divalent organic group (l and m represent an integer from 1 to 5). ＊ ₁ represents the bonding site with the benzene ring in formula (9). * ₂ represents the position to bond with the amine group in formula (9). n represents an integer from 1 to 3. Among them, from the viewpoint of the relaxation of the accumulated charge, R _{11 is} preferably a single bond, -O-, -COO-, -OCO-, -CONH- or NHCO-.

n represents an integer from 1 to 3. Preferably it is 1 or 2.

As a specific example of the diamine represented by the said formula (9), the diamine represented by the following formula (9-1-1)-formula (9-1-12) can be illustrated. Among them, from the viewpoint of the relaxation of the accumulated charge, the formulas (9-1-1), (9-1-2), (9-1-3), (9-1-5), (9-1 -8), (9-1-9), (9-1-10), (9-1-11) or (9-1-12) is preferably, in the formula (9-1-1), ( 9-1-2), (9-1-3), (9-1-11) or (9-1-12) are particularly preferred.

<Other Diamines>

In the present invention, a diamine other than the specific diamine may be used in combination as a part of the diamine component. The other diamines are not particularly limited, and, for example, the side chain type diamines described in detail below can be mentioned. The side chain diamine can be preferably used when manufacturing a vertical alignment type liquid crystal display element.

The specific side chain diamine is a diamine represented by the following formula (10).

In formula (10), Y ¹ is a single bond, -(CH ₂ ) _a- (a is an integer of 1 to 15), -O-, -CH ₂ O-, -COO-, or OCO-. Among them, a single bond, -(CH ₂ ) _a- (a is an integer from 1 to 15), -O-, -CH ₂ O- or COO- is preferred because it is easy to synthesize a side chain structure. More preferably, it is a single bond, -(CH ₂ ) _a- (a is an integer of 1 to 10), -O-, -CH ₂ O- or COO-.

Y ² is a single bond or (CH ₂ ) _b- (b is an integer of 1-15). Among them, a single bond or (CH ₂ ) _b- (b is an integer of 1 to 10) is preferred.

Y ³ is a single bond, -(CH ₂ ) _c- (c is an integer of 1 to 15), -O-, -CH ₂ O-, -COO- or OCO-. Among them, the single bond, -(CH ₂ ) _c- (c is an integer from 1 to 15), -O-, -CH ₂ O-, -COO- or OCO- systems are preferred because they are easy to synthesize. More preferably, it is a single bond, -(CH ₂ ) _c- (c is an integer of 1 to 10), -O-, -CH ₂ O-, -COO- or OCO-.

Y ⁴ is a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring. Any hydrogen atoms on these cyclic groups can be substituted by alkyl groups with 1 to 3 carbons, alkoxy groups with 1 to 3 carbons, fluorinated alkyl groups with 1 to 3 carbons, and fluorinated alkyl groups with 1 to 3 carbons. Substituted by fluorine-containing alkoxy or fluorine atom. Furthermore, Y ⁴ is a divalent organic group with 12 to 25 carbon atoms having a steroid skeleton. As the Y ⁴ system, a benzene ring, a cyclohexyl ring, or an organic group having 12 to 25 carbon atoms having a steroid skeleton is preferred.

Y ⁵ is a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexyl ring and a heterocyclic ring. Any hydrogen atoms on these cyclic groups can be substituted by alkyl groups with 1 to 3 carbons, alkoxy groups with 1 to 3 carbons, fluorinated alkyl groups with 1 to 3 carbons, and fluorinated alkyl groups with 1 to 3 carbons. Substituted by fluorine-containing alkoxy or fluorine atom.

n is an integer from 0 to 4. Preferably, it is an integer of 0-2.

Y ⁶ is an alkyl group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or a fluorinated alkoxy group having 1 to 18 carbon atoms. Among them, a C1-C18 alkyl group, a C1-C10 fluorine-containing alkyl group, a C1-C18 alkoxy group, or a C1-C10 fluorine-containing alkoxy group are preferred. It is also preferably an alkyl group having 1 to 12 carbons or an alkoxy group having 1 to 12 carbons. More preferably, it is an alkyl group having 1 to 9 carbons or an alkoxy group having 1 to 9 carbons.

m is an integer from 1 to 4. Preferably, it is an integer of 1.

More specifically, it is a diamine represented by following formula (10-1)-(10-31).

In formulas (10-1) to (10-3), R ¹ represents -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -or CH ₂ OCO-. R ² is a C 1-22 alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group.

In formula (10-4) ~ formula (10-6), R ³ represents -COO-, -OCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -or CH ₂ -. R ⁴ is a C 1-22 alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group.

In formulas (10-7) to (10-8), R ⁵ represents -COO-, -OCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -,- CH ₂ -or O-. R ⁶ is a fluoro group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a methanoyl group, an acetyl group, an acetoxy group, or a hydroxyl group.

In formulas (10-9) to (10-10), R ⁷ is an alkyl group having 3 to 12 carbons. The cis-trans isomers of 1,4-cyclohexylene are respectively trans isomers.

In formulas (10-11) to (10-12), R ⁸ is an alkyl group having 3 to 12 carbon atoms. The cis-trans isomers of 1,4-cyclohexylene are respectively trans isomers.

In the formula (10-13), A ⁴ is an alkyl group having 3 to 20 carbon atoms which may be substituted with a fluorine atom. A ³ is 1,4-cyclohexylene or 1,4-phenylene. A ² is an oxygen atom or COO-* (but the bonding part with "*" is bonded to A ³ ). A ¹ is an oxygen atom or COO-* (but the bonding part with "*" is bonded to (CH ₂ )a ₂ ). In addition, a ₁ is an integer of 0 or 1. a ₂ is an integer from 2 to 10. a ₃ is an integer of 0 or 1.

Among the above formulas (10-1)~(10-31), particularly preferred diamine system formula (10-1)~ formula (10-6), formula (10-9)~ formula (10-13), Formula (10-16), Formula (10-19), Formula (10-23), Formula (10-25) or Formula (10-29), etc.

As another diamine, the diamine represented by following formula (11) can also be mentioned.

In formula (11), Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene. These aromatic hydrocarbon groups may also be substituted by organic groups, and hydrogen atoms may also be substituted by halogen atoms. R ₁ and R ₂ are each independently an alkyl group, alkoxy group, benzyl group or phenethyl group with 1 to 10 carbon atoms. If it is an alkyl group or alkoxy group, R ₁ and R ₂ can also be used To form a ring. T ₁ and T ₂ are independently single bonds or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -The bonding group of CON(CH ₃ )- or N(CH _{3 )CO-.} S is a single bond or an unsubstituted or substituted alkylene group with 1 to 20 carbon atoms (but -CH ₂ -or CF ₂ -of the alkylene group can be optionally substituted by -CH=CH-, in When any of the groups listed below are not adjacent to each other, they can also be substituted by these groups: -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, two Valence carbocyclic, divalent heterocyclic ring.). Q represents the following structure.

In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₃ represents -CH ₂ -, -NR-, -O- or S-.

Specifically, the following diamines are mentioned.

(In the formula, n represents an integer from 1 to 8)

Examples of other diamines include diamines of the following formula or diamines described on pages 30 to 33 of International Publication 2014/171493 (published on October 23, 2014).

The above-mentioned other diamines may be used in one type or a mixture of two or more types in accordance with the characteristics of liquid crystal alignment, voltage retention, and accumulated charge when used as a liquid crystal alignment film.

<Tetracarboxylic dianhydride component>

The polymer contained in the liquid crystal alignment agent used in the present invention is not particularly limited to the tetracarboxylic dianhydride used as a raw material, but tetracarboxylic acids represented by the following formulas (12) to (14) are used The dianhydride (also referred to as a specific tetracarboxylic dianhydride) is preferred.

In the formula (12), Z ¹ is a tetravalent organic group having 4 to 13 carbons, and contains a non-aromatic cyclic hydrocarbon group having 4 to 10 carbons.

Specifically, it is a base represented by the following formulas (12a) to (12j).

In formula (12a), Z ² to Z ⁵ are groups independently selected from a hydrogen atom, a methyl group, a chlorine atom, or a benzene ring. In the formula (6g), Z ⁶ and Z ⁷ are each independently a hydrogen atom or a methyl group.

In formula (12), in terms of polymerization reactivity or ease of synthesis, particularly preferred Z ¹ is formula (12a), formula (12c), formula (12d), formula (12e), formula (12f) or formula (12g).

In formula (13) or formula (14), j and k are independently 0 or 1, respectively. x and y are each independently a single bond, a carbonyl group, an ester group, a phenylene group, a sulfonyl group, or an amide group.

As a specific tetracarboxylic dianhydride, tetracarboxylic dianhydrides represented by the following formulas (12-1) to (12-5) are preferred. Among them, the residual image (accumulated charge) of the obtained liquid crystal display element From the viewpoint of ), (12-1), (12-3) or (12-5) is preferred.

<Other tetracarboxylic dianhydrides>

In the present invention, other tetracarboxylic dianhydrides other than the specific tetracarboxylic dianhydride can be used. Examples of other tetracarboxylic dianhydrides include tetracarboxylic dianhydrides of tetracarboxylic acids as shown below.

Examples include 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7 -Anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 2,3,3',4'-biphenyl tetracarboxylic acid, bis(3,4-dicarboxyphenyl) ether, 3, 3',4,4'-benzophenone tetracarboxylic acid, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1, 1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4- Dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,4,9,10-perylene tetracarboxylic acid Carboxylic acid or 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid.

The above-mentioned other tetracarboxylic dianhydrides can be used singly or in combination of two or more of them in accordance with the characteristics of liquid crystal alignment, voltage retention, and accumulated charge when used as a liquid crystal alignment film.

The liquid crystal alignment agent of the present invention may additionally contain components other than the specific polymer component. As such additional components, there can be mentioned an adhesion auxiliary agent 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 group selected from the group used to increase the strength of the liquid crystal alignment film A crosslinking agent of at least one of the following formulas (17), (19), and (21), a dielectric substance or a conductive substance or an organic solvent for adjusting the permittivity or resistance of the liquid crystal alignment film. As specific examples of these additional components, there are various disclosures in well-known literature on liquid crystal alignment agents, such as those described in International Publication No. 2015/060357, page 53 [0105] to page 55 [0116] Reveal the ingredients, etc.

In formula (17), R ₂₀ , R ₂₁ , R ₂₅ and R ₂₆ are each independently a hydrogen atom, an alkyl group with 1 to 4 carbons, an alkenyl group with 2 to 4 carbons, or an alkynyl group with 2 to 4 carbons. , And at least one is a group represented by formula (18). R ₂₂ and R ₂₄ are each independently represented as an aromatic ring. Any hydrogen atom of the aromatic ring can be replaced by a hydroxyl group, an alkyl group with 1 to 3 carbons, a halogen atom, an alkoxy group with 1 to 3 carbons, or a vinyl group. replace. R ₂₃ is a single bond, all or part of which can be bonded to form a saturated hydrocarbon group with 1 to 10 carbon atoms in a ring structure.

In formula (19), R ₂₇ is an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an n-valent organic group containing an aromatic hydrocarbon group, and c is an integer of 2 to 6. R ₂₈ and R ₂₉ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbons, an alkenyl group having 2 to 4 carbons, or an alkynyl group having 2 to 4 carbons, and these groups may have substituents. In addition _{, at least one of R 28} and R ₂₉ has a hydroxyl group as a substituent. In addition, it _{is preferable that at least one of R 28} and R ₂₉ is substituted with a group represented by formula (20). In formula (20), R ₃₀ to R ₃₃ are each independently a hydrogen atom, a hydrocarbon group, or a hydrocarbon group substituted with a hydroxyl group.

In formula (21), R ₃₄ and R ₃₈ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbons, and R ₃₅ and R ₃₇ are each independently an aromatic ring, and any hydrogen atom of the aromatic ring may be It is substituted by a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or a vinyl group. R ₃₆ is a single bond, all or part of it can be bonded to form a saturated hydrocarbon group with 1 to 10 carbon atoms in a cyclic structure, and any hydrogen atom can be replaced by a fluorine atom, -NH-, -N(CH ₃ )- Or the base represented by formula (22). In formula (22), P ₁ and P ₂ are each independently an alkyl group having 1 to 5 carbon atoms, and Q ₁ represents an aromatic ring), and in formula (21), d and f are each independently 1 to 3 The integers of e and g are independently integers from 1 to 3.

As a specific example of the compound represented by said formula (17)-(22), the following 3 types can be mentioned.

<Polymer>

In the present invention, a known polymerization method can be used as a method of synthesizing a polymer. For example, the method described on pages 39 to 42 of International Publication 2014/171493 (published on October 23, 2014).

<Liquid crystal alignment agent>

The polymer components in the liquid crystal alignment agent of the present invention may be all the specific polymers used in the present invention, or other polymers other than these may be mixed with the specific polymer of the present invention. At this time, the content of other polymers other than the specific polymer is 0.5 to 15% by mass, preferably 1 to 10% by mass.

Examples of other polymers include diamine components made of diamines other than specific diamines, polyimide precursors obtained from tetracarboxylic dianhydride components, or the polyimide A polyimide obtained by imidizing an imine precursor. Furthermore, as other polymers other than these, acrylic polymers, methacrylic polymers, polystyrene, polyamide, and the like can also be cited.

For the organic solvent in the liquid crystal alignment agent of the present invention, from the viewpoint of forming a uniform polymer film by coating, the content of the organic solvent is preferably 70 to 99% by mass. The content can be appropriately changed according to the film thickness of the target liquid crystal alignment film. The organic solvent at this time is not particularly limited as long as it can dissolve the above-mentioned specific polymer. More specifically, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactone, 2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinylpyrrolidone, dimethyl sulfide, tetramethylurea, pyridine, dimethyl sulfide, hexamethyl sulfide, γ-butane Lactone, 1,3-dimethyl-imidazolinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone , Ethylene carbonate, propylene carbonate, diglyme or 4-hydroxy-4-methyl-2-pentanone, etc. These systems can be used alone or in combination.

The liquid crystal alignment agent of the present invention may contain: a crosslinkable compound having an epoxy group, an isocyanate group, an oxetanyl group, or a cyclocarbonate group, and at least 1 selected from the group consisting of a hydroxyl group or an alkoxy group. Cross-linkable compounds with different substituents or cross-linkable compounds with polymerizable unsaturated bonds, etc.

In addition, as a compound that improves the uniformity of the film thickness or the surface smoothness, it may also contain a fluorine-based surfactant, a polysiloxane-based surfactant, or a non-ionic surfactant, etc., as the alignment film between the liquid crystal and the substrate. The adhesion-improving compound may also contain: functional silane-containing compound or epoxy-containing compound.

In addition, a dielectric or conductive substance for the purpose of changing the electrical characteristics such as the dielectric constant and conductivity of the liquid crystal alignment film may be added.

The liquid crystal alignment agent of the present invention may contain an organic solvent (also referred to as a poor solvent) or a compound that improves the uniformity or surface smoothness of the polymer film when the liquid crystal alignment agent is applied. Furthermore, it may contain the compound etc. which improve the adhesiveness of a liquid crystal alignment film and a board|substrate.

As a poor solvent that improves the uniformity of the film thickness or the surface smoothness, the following specific examples can be given.

Examples include isopropanol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butylene Base carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol , Propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether , Dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate Monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl Base ether, diisobutylene, pentyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane , N-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, Methyl 3-methoxypyruvate, methyl ethyl 3-ethoxypyruvate, ethyl 3-methoxypyruvate, 3-ethoxypyruvate, 3-methoxypyruvate, 3- Propyl methoxypyruvate, butyl 3-methoxypyruvate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol , 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2- Acetate, dipropylene glycol, 2-(2-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate or isoamyl lactate, etc. Surface tension organic solvent.

These poor solvents can be used singly or in combination of multiple types. When using the above-mentioned poor solvent, 5 to 80% by mass of the total organic solvent contained in the liquid crystal alignment agent is preferably 5 to 80% by mass, and more preferably 20 to 60% by mass.

<LCD>

As the liquid crystal composition used in the liquid crystal display element of the present invention, for the horizontal alignment type liquid crystal display element, a nematic liquid crystal with positive dielectric anisotropy is used, and a negative dielectric can also be used depending on the application. Anisotropic nematic liquid crystal.

系液晶、希夫鹼(Schiff base)系液晶、氧化偶氮系液晶、聯苯系液晶、苯基環己烷系液晶或聯三苯系液晶等。又，液可併用烯基系液晶。作為如此般的烯基系液晶，可使用以往周知者。可舉例如下述式所表示之化合物等。 For vertical alignment type liquid crystal display elements, nematic liquid crystals with negative dielectric anisotropy can be used. For example, dicyanobenzene series liquid crystal,

Liquid crystal, Schiff base liquid crystal, azo liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal or triphenyl liquid crystal, etc. In addition, alkenyl liquid crystals can be used in combination with the liquid. As such an alkenyl-based liquid crystal, conventionally known ones can be used. Examples thereof include compounds represented by the following formulas.

<Liquid crystal alignment film, liquid crystal display element>

The liquid crystal alignment agent of the present invention is coated on a BOA substrate or a substrate with BCS and fired, and then subjected to alignment processing by rubbing treatment or light irradiation, etc., and can be used as a liquid crystal alignment film. Moreover, in the case of vertical alignment applications, etc., it can be used as a liquid crystal alignment film even if alignment processing is not performed.

In the present invention, the BOA substrate is a substrate on which a black matrix is formed on the COA substrate. As the material used in the aforementioned black matrix, a column spacer (black column spacer (BCS)) that supports the array substrate and the counter substrate can also be used.

In addition, the BCS-attached substrate uses a black colored resin composition as a material for supporting the column spacers between the array substrate and the counter substrate and forms the substrate for the black column spacers, and the black colored resin composition is also The aforementioned black matrix materials can be used.

For BOA substrates or substrates with BCS, for example, a colored resin composition can be coated on a transparent substrate by spin coating, etc., dried using a vacuum dryer or a hot plate, etc., and then passed through a photomask using an ultra-high pressure mercury lamp, etc. After exposure and development using a KOH aqueous solution, etc., it is formed by firing it in a hot air circulating oven. As the colored resin composition, for example, a black matrix and a colored resin composition for BCS prepared in accordance with the method described in "0312" to "0314" of JP 2014-67028 A can be used.

The transparent substrate used at this time is not particularly limited as long as it has high transparency, and plastic substrates such as glass substrates, acrylic substrates, and polycarbonate substrates may also be used. From the viewpoint of simplification of the manufacturing process, it is preferable to use a substrate formed with ITO electrodes for liquid crystal driving and the like. In addition, in the case of a reflective liquid crystal display element, an opaque substrate such as a silicon wafer may be used as the substrate only on one side, and a material that reflects light such as aluminum may also be used as the electrode in this case.

The coating method of the liquid crystal alignment agent is not particularly limited. In the industry, screen printing, offset printing, flexographic printing, inkjet, etc. are usually used in the industry. As other coating methods, there are dipping, roll coating, slit coater, spinner, etc., and these can also be used according to the purpose.

After the liquid crystal alignment agent is coated on the BOA substrate or the substrate with BCS, the solvent is evaporated at 50~300℃, preferably 80~250℃ by heating means such as a hot plate, so that a polymer film can be made . If the thickness of the polymer film after firing is too thick, it is disadvantageous in terms of the power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease, so it is preferably 5 ~300nm, and preferably 10~100nm. When the liquid crystals are aligned horizontally or obliquely, rubbing or polarized ultraviolet irradiation is used to process the fired polymer film.

In addition, for vertical alignment type liquid crystal display elements, it is known that a photopolymerizable compound is added to the liquid crystal composition in advance and used with a vertical alignment film such as polyimide. Or DC voltage is irradiated with ultraviolet rays to polymerize the polymerizable compound to control the alignment of the liquid crystal and improve the response speed of the liquid crystal. The content of the PSA (Polymer sustained Alignment) element is reported in Japanese Patent Laid-Open No. 2003-307720, etc. .

Examples of the polymerizable compound include compounds having one or more polymerizable unsaturated groups such as acrylate groups or methacrylate groups in the molecule. At this time, the polymerizable compound is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the liquid crystal component, and more preferably 0.1 to 5 parts by mass. If the polymerizable compound is less than 0.01 parts by mass, the alignment of the liquid crystal cannot be controlled because the polymerizable compound cannot be polymerized. If it is more than 10 parts by mass, the unreacted polymerizable compound will increase and the liquid crystal display element The afterimage characteristic is reduced.

On the other hand, according to non-patent documents such as (SC-PVA liquid crystal display) K. Hanaoka, SID 04 DIGEST, P.1200-1202, etc., it has been reported that by adding a photopolymerizable compound to the liquid crystal alignment film, It is not in the liquid crystal composition, which can accelerate the response speed of the liquid crystal display element.

[Example]

Hereinafter, it will be described in more detail based on the examples, but the present invention is not limited by the examples.

The abbreviations are as follows.

(Acid dianhydride)

BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride, PMDA: coke honey Stone acid dianhydride, TCA: 2,3,5-tricarboxycyclopentyl acetic acid-1,4,2,3-dianhydride

(Diamine)

PDA: p-phenylenediamine, DDM: 4,4'-methylene bisdiphenylamine, DBA: 3,5-diaminobenzoic acid, the nitrogen-containing bismuth represented by the following formulas DA-N1~DA-N7 Amine

The vertical alignment side chain diamine represented by the following formula DA-S1~DA-S3

The photosensitive diamine represented by the following formula DA-1

<Solvent>

NMP: N-methyl-2-pyrrolidone, BC: Butyl cellosolve

<Additives>

3AMP: 3-picolylamine (3-picolylamine)

<Crosslinking agent>

Crosslinking agent represented by the following formula CL-1~CL-3

(Conditions for determination of molecular weight of polyimide)

Device: Normal Temperature Gel Permeation Chromatography (GPC) device (SSC-7200) manufactured by Senshu Science Company, column: column (KD-803, KD-805) manufactured by Shodex Company, column temperature: 50°C, eluent: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr‧H ₂ O) is 30mmol/L, phosphoric acid‧anhydrous crystal (o-phosphoric acid) is 30mmol/L, tetrahydrofuran (THF) is 10ml/L), flow rate: 1.0ml/min, standard sample for calibration line production: TSK standard polyethylene oxide manufactured by Tosoh (molecular weight approximately 9000,000, 150,000, 100,000, 30,000) and polymer manufactured by Polymer Laboratories Ethylene glycol (molecular weight approximately 12,000, 4,000, 1,000).

(Polyimide rate of imidization)

5)中，添加氘化二甲亞碸(DMSO-d₆、0.05%TMS混合品)1.0ml，施以超音波使其完全地溶解。將該溶液藉由日本電子datum公司製NMR測定器(JNW-ECA500)來測定500MHz的質子NMR。醯亞胺化率係將來自於醯亞胺化前後未變化的構造的質子定為基準質子，使用該質子的波峰累積值、與9.5~10.0ppm附近所出現的來自於醯胺酸的NH基的質子波峰累積值，並依以下式而求得。尚下述式中，x係來自於醯胺酸的NH基的質子波峰累積值，y係基準質子的波峰累積值，α係聚醯胺酸(醯亞胺化率為0%)之情形時相對於1個醯胺酸的NH基的質子之基準質子的個數比例。 Put 20 mg of polyimide powder into the NMR sample tube (NMR sampling tube stand manufactured by Kusano Science Co., Ltd.)

In 5), add 1.0 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS mixture), and apply ultrasonic waves to completely dissolve it. This solution was used to measure proton NMR at 500 MHz with an NMR measuring device (JNW-ECA500) manufactured by JEOL Datum Corporation. The rate of imidization is based on the proton derived from the unchanged structure before and after imidization as the reference proton, and the peak cumulative value of this proton is used to compare with the NH group derived from amidic acid that appears near 9.5 to 10.0 ppm. The cumulative value of the peak of the proton is obtained according to the following formula. In the following formula, x is the cumulative value of proton peaks derived from the NH group of amic acid, y is the cumulative value of peak protons of reference protons, and in the case of α-based polyamide (the imidation rate is 0%) The ratio of the number of standard protons relative to the protons of the NH group of one amic acid.

The imidization rate (%)=(1-α‧x/y)×100

(Synthesis example 1)

Dissolve BODA (18.77g, 75.0mmol), DBA (10.65g, 70.0mmol) and DA-S2 (13.04g, 30.0mmol) in NMP (141.5g), make it react at 80℃ for 5 hours, then add CBDA (4.71 g, 24.0 mmol) and NMP (47.2 g) were reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (200g) and diluting to 6.5% by mass, acetic anhydride (43.1g) and pyridine (13.4g) as catalysts for imidization were added, and the mixture was heated at 100°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (A). The imidization rate of this polyimide was 78%, the number average molecular weight was 22,000, and the weight average molecular weight was 56,000.

NMP (44.0g) was added to the obtained polyimide powder (A) (6.0g), and it stirred at 70 degreeC for 20 hours, and made it melt|dissolve. To this solution, 6.0 g of 3AMP (1% by mass NMP solution), NMP (4.0 g), and BC (40.0 g) were added, and the liquid crystal alignment agent (A1) was obtained by stirring at room temperature for 5 hours.

(Synthesis example 2)

Dissolve BODA (5.00g, 20.0mmol), DA-N1 (7.27g, 30.0mmol), DA-S1 (11.42g, 30.0mmol) and PDA (4.33g, 40.0mmol) in NMP (113.8g) to After reacting for 3 hours at 60°C, CBDA (11.37g, 58.0mmol) and NMP (26.3g) were added, and after reacting at 40°C for 1 hour, PMDA (4.36g, 20.0mmol) and NMP (35.00g) were added ), and reacted at room temperature for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (200g) and diluting to 6.5% by mass, acetic anhydride (46.3g) and pyridine (14.3g) as catalysts for imidization were added and heated at 50°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (B). The imidization rate of this polyimide was 76%, the number average molecular weight was 13,000, and the weight average molecular weight was 32,000.

Using the obtained polyimide powder (B) (6.0 g), the liquid crystal alignment agent (B1) can be obtained in the same manner as in Synthesis Example 1.

(Synthesis example 3)

Dissolve BODA (5.00g, 20.0mmol), DA-N1 (7.27g, 30.0mmol), DA-S1 (11.42g, 30.0mmol) and DBA (6.09g, 40.0mmol) in NMP (118.3g) to After reacting at 60°C for 3 hours, CBDA (11.37g, 58.0mmol) and NMP (27.3g) were added, and after reacting at 40°C for 1 hour, PMDA (4.36g, 20.0mmol) and NMP (36.41g) were added. ), and reacted at room temperature for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (200g) and diluting to 6.5% by mass, acetic anhydride (44.5g) and pyridine (13.8g) as catalysts for imidization were added, and the mixture was heated at 50°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (C). The imidization rate of this polyimide was 79%, the number average molecular weight was 21,000, and the weight average molecular weight was 49,000.

Using the obtained polyimide powder (C) (6.0 g), in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (C1) can be obtained.

(Synthesis example 4)

Dissolve TCA (22.19g, 99.0mmol), DDM (9.91g, 50.0mmol), DA-N2 (7.64g, 25.0mmol) and DA-S3 (12.37g, 25.0mmol) in NMP (208.4g), and It was made to react at 60 degreeC for 10 hours, and the polyamic acid solution was obtained.

After adding NMP to the polyamide acid solution (200g) and diluting it to 6.5% by mass, acetic anhydride (37.6g) and pyridine (11.6g) as catalysts for imidization were added and heated at 110°C. React for 4 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (D). The imidization rate of this polyimide was 68%, the number average molecular weight was 11,000, and the weight average molecular weight was 25,000.

Using the obtained polyimide powder (D) (6.0 g), in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (D1) can be obtained.

(Synthesis example 5)

Dissolve BODA (18.77g, 75.0mmol), DA-N3 (11.78g, 30.0mmol), DBA (3.04g, 20.0mmol) and DA-S1 (19.03g, 50.0mmol) in NMP (171.9g) to After making it react at 80 degreeC for 5 hours, CBDA (4.71g, 24.0 mmol) and NMP (57.32g) were added, and it was made to react at 40 degreeC for 10 hours, and the polyamic acid solution was obtained.

After adding NMP to the polyamide acid solution (200 g) and diluting to 6.5% by mass, acetic anhydride (35.5 g) and pyridine (11.0 g) as catalysts for imidization were added, and the mixture was heated at 100°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 100°C to obtain polyimide powder (E). The imidization rate of this polyimide was 75%, the number average molecular weight was 16,000, and the weight average molecular weight was 39,000.

Using the obtained polyimide powder (E) (6.0 g) in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (E5) can be obtained.

(Synthesis Example 6)

Dissolve BODA (18.77g, 75.0mmol), DA-N4 (9.96g, 50.0mmol) and DA-S1 (19.03g, 50.0mmol) in NMP (157.4g), and react at 80°C for 5 hours , CBDA (4.12g, 21.0mmol) and NMP (52.46g) were added, and it was made to react at 40 degreeC for 10 hours, and the polyamide acid solution was obtained.

After adding NMP to the polyamide acid solution (200g) and diluting to 6.5% by mass, acetic anhydride (38.8g) and pyridine (12.0g) as catalysts for imidization were added and heated at 100°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (F). The imidization rate of this polyimide was 57%, the number average molecular weight was 10,000, and the weight average molecular weight was 24,000.

Using the obtained polyimide powder (F) (6.0 g), in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (F1) can be obtained.

(Synthesis Example 7)

Dissolve BODA (12.51g, 50.0mmol), PDA (3.24g, 30.0mmol), DA-N5 (11.13g, 20.0mmol) and DA-S1 (19.03g, 50.0mmol) in NMP (166.6g) to After reacting at 60°C for 3 hours, CBDA (9.51 g, 48.5 mmol) and NMP (41.11 g) were added and reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (180g) and diluting to 6.5% by mass, acetic anhydride (36.6g) and pyridine (11.4g) as catalysts for imidization were added and reacted at 80°C 2 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 80°C to obtain polyimide powder (F). The imidization rate of this polyimide was 73%, the number average molecular weight was 17,000, and the weight average molecular weight was 38,000.

Using the obtained polyimide powder (G) (6.0 g), in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (G1) can be obtained.

(Comparative Synthesis Example 1)

Dissolve BODA (12.51g, 50.0mmol), DA-1 (16.52g, 50.0mmol) and DA-S1 (19.03g, 50.0mmol) in NMP (192.2g), and after reacting at 60°C for 3 hours, add PMDA (4.36 g, 48.5 mmol), CBDA (9.61 g, 49.0 mmol) and NMP (38.4 g) were reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (200g) and diluting to 6.5% by mass, acetic anhydride (35.3g) and pyridine (10.9g) as catalysts for imidization were added, and the mixture was heated at 80°C. React for 3 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (H). The imidization rate of this polyimide was 73%, the number average molecular weight was 17,000, and the weight average molecular weight was 48,000.

Using the obtained polyimide powder (H) (6.0 g) in the same manner as in Synthesis Example 1, a liquid crystal alignment agent (H1) can be obtained.

(Comparative Synthesis Example 2)

Dissolve BODA (12.51g, 50.0mmol), PDA (5.41g, 50.0mmol) and DA-S1 (19.03g, 50.0mmol) in NMP (147.7g), react at 60°C for 3 hours, then add BDA ( 9.41g, 48.0mmol) and NMP (37.7g) were reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (200 g) and diluting to 6.5% by mass, acetic anhydride (43.7 g) and pyridine (13.5 g) as catalysts for imidization were added, and the mixture was heated at 80°C. React for 2 hours. This reaction solution was poured into methanol (2700 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (I). The imidization rate of this polyimide was 72%, the number average molecular weight was 13,000, and the weight average molecular weight was 25,000.

Using the obtained polyimide powder (I) (6.0 g) in the same manner as in Synthesis Example 1, the liquid crystal alignment agent (I1) can be obtained.

(Synthesis example 8)

6.0 g of the liquid crystal alignment agent (H1) obtained in Comparative Synthesis Example 1 as the first component and 14.0 g of the liquid crystal alignment agent (C1) obtained in Synthesis Example 3 as the second component were mixed, and stirred for 1 hour to prepare liquid crystals Alignment agent (J1).

(Synthesis Example 9)

6.0 g of the liquid crystal alignment agent (I1) obtained in Comparative Synthesis Example 2 as the first component and 14.0 g of the liquid crystal alignment agent (C1) obtained in Synthesis Example 3 as the second component were mixed, and stirred for 1 hour to prepare liquid crystals Alignment agent (K1).

(Synthesis example 10)

For 10.0 g of the liquid crystal alignment agent (A1) obtained in Synthesis Example 1, CL-2 was added so that the resin content reached 10 wt%, and the liquid crystal alignment agent (A2) was prepared by stirring at room temperature for 1 hour.

(Synthesis Example 11)

For 10.0 g of the liquid crystal alignment agent (D1) obtained in Synthesis Example 4, CL-1 was added so that the resin content reached 10 wt%, and the liquid crystal alignment agent (D2) was prepared by stirring at room temperature for 1 hour.

(Synthesis example 12)

For 10.0 g of the liquid crystal alignment agent (K1) obtained in Synthesis Example 9, CL-3 was added so that the resin content reached 10 wt%, and the liquid crystal alignment agent (K2) was prepared by stirring at room temperature for 1 hour.

(Synthesis Example 13)

Dissolve BODA (2.50g, 10.0mmol), DA-N6 (3.97g, 10.0mmol) and DA-S1 (3.81g, 10.0mmol) in NMP (41.1g), and after reacting at 60°C for 3 hours, add CBDA (1.88 g, 9.60 mmol) and NMP (7.5 g) were reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (40g) and diluting to 6.5% by mass, acetic anhydride (6.68g) and pyridine (2.07g) as catalysts for imidization were added, and the mixture was heated at 80°C. React for 3 hours. This reaction solution was poured into methanol (461 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 60°C to obtain polyimide powder (L). The imidization rate of this polyimide was 72%, the number average molecular weight was 15,000, and the weight average molecular weight was 28,000.

Using the obtained polyimide powder (L) (6.0 g), the liquid crystal alignment agent (L1) can be obtained in the same manner as in Synthesis Example 1.

(Synthesis example 14)

Dissolve BODA (2.50g, 10.0mmol), DA-N7 (3.41g, 10.0mmol) and DA-S1 (3.81g, 10.0mmol) in NMP (38.9g), react at 60℃ for 3 hours, then add CBDA (1.88 g, 9.60 mmol) and NMP (7.5 g) were reacted at 40°C for 10 hours to obtain a polyamide acid solution.

After adding NMP to the polyamide acid solution (40g) and diluting to 6.5% by mass, acetic anhydride (6.99g) and pyridine (2.17g) as catalysts for imidization were added, and the mixture was heated at 80°C. React for 3 hours. This reaction solution was poured into methanol (463 ml), and the obtained precipitate was collected by filtration. This precipitate was washed with methanol and dried under reduced pressure at 60°C to obtain polyimide powder (M). The imidization rate of this polyimide was 70%, the number average molecular weight was 14,000, and the weight average molecular weight was 30,000.

Using the obtained polyimide powder (M) (6.0 g), the liquid crystal alignment agent (M1) can be obtained in the same manner as in Synthesis Example 1.

(Example 1)

According to the following procedure, the liquid crystal alignment agent A1 obtained in Synthesis Example 1 was used to produce a liquid crystal cell, and the pretilt angle and the voltage holding ratio were measured.

<Preparation of colored resin composition>

The colored resin composition (a) for the black column spacer (BCS) used in the present invention can also be used as the resin composition of the black matrix material, and it uses "0312" ~ "0314" of JP 2014-67028 Modulate in the same way as the photoresist (VI) described in.

<Production of ITO substrate with BCS>

The above-mentioned colored resin composition (a) is spin-coated so that the film thickness after firing becomes 4μm to a pixel size of 100μm×300μm and a line width/pitch of 5μm/5μm is formed with an ITO electrode pattern attached ITO electrodes on the glass substrate. Then, after drying with a vacuum dryer for 60 seconds, it was dried on a hot plate at 110° C. for 2 minutes to obtain a pre-exposure substrate with the colored resin composition (a).

For this pre-exposure substrate, a round mask with an opening of 20 μm was exposed at 50 mJ/cm2 using an ultra-high pressure mercury lamp, and then developed using a KOH aqueous solution with a concentration of 0.05% by mass at a temperature of 25°C. After that, using a hot air circulating oven, the substrate with the photoresist (VI) was fired at 230° C. for 30 minutes to obtain an ITO substrate with BCS.

<Production of Liquid Crystal Cell>

Using the liquid crystal alignment agent (A1), the liquid crystal cell was produced according to the procedure shown below. The liquid crystal alignment agent (A1) was spin-coated on the ITO surface of the ITO substrate with BCS, dried on a hot plate at 80°C for 90 seconds, and then fired in a hot air circulating oven at 200°C for 30 minutes. Thus, a liquid crystal alignment film with a film thickness of 100 nm was formed.

In addition, the liquid crystal alignment agent (A1) was spin-coated on the ITO surface where the electrode pattern was not formed, and dried on a hot plate at 80°C for 90 seconds, and then heated in a hot air circulating oven at 200°C for 30 minutes It is fired to form a liquid crystal alignment film with a film thickness of 100 nm.

For the above-mentioned two substrates, a thermosetting sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was printed on the liquid crystal alignment film of one substrate. Next, the side surface of the other substrate on which the liquid crystal alignment film is formed is positioned on the inside, and after bonding to the above-mentioned substrate, the sealant is hardened to produce an empty cell. Liquid crystal MLC-3023 (trade name, alkenyl-based liquid crystal, manufactured by Merck Corporation) containing a polymerizable compound for PSA was injected into the empty cell by a reduced pressure injection method to produce a liquid crystal cell. The voltage holding ratio (VHR) of the liquid crystal cell was measured.

Next, with a 15V DC voltage applied to the liquid crystal cell, 10 J/cm ² of UV passed through a 365 nm band pass filter was irradiated from the outside of the liquid crystal cell (also referred to as primary PSA treatment). The illuminance of UV was measured using UV-MO3A (accessory: UV-35) manufactured by ORC Corporation. After that, for the purpose of passivating unreacted polymerizable compounds remaining in the liquid crystal cell, UV-FL irradiation equipment manufactured by Toshiba Lighting Co., Ltd. was used to irradiate UV (UV lamp: FLR40SUV32/A-1) without applying voltage. ) 30 minutes (also known as 2 PSA treatments). Afterwards, the pretilt angle of the pixel portion and the voltage retention rate were measured for the unit cell after UV irradiation.

"Determination of pretilt angle"

The measurement was performed using LCD analyzer LCA-LUV42A (manufactured by Meiling Technica).

"Evaluation of Voltage Holding Rate"

Apply a voltage of 1V for 60μs in a hot air circulating oven at 60°C, then measure the voltage after 1667msec, and calculate how much the voltage can be maintained as the voltage retention rate. The voltage holding ratio was measured using VHR-1 manufactured by Toyo Technica.

(Examples 2-14, Comparative Examples 1 and 2)

Except that the liquid crystal alignment agent (A1) used in Example 1 was changed to the liquid crystal alignment agent (B1)~(M1), (A2), (D2) or (K2), the same operation as in Example 1 was performed, and Perform the measurement of pretilt angle and voltage retention rate.

(Example 1')

In accordance with the same operation as in Example 1, a liquid crystal cell was fabricated using an ITO-attached electrode substrate without BCS attached, and the pretilt angle and voltage holding ratio were measured. Still, in order to maintain the cell gap, a 4 μm bead spacer was used instead of the black column spacer and spread on the liquid crystal alignment film.

(Examples 2’-14’, Comparative Examples 1’ and 2’)

Except that the liquid crystal alignment agent (A1) used in Example 1'was changed to liquid crystal alignment agent (B1)~(M1), (A2), (D2) or (K2), the same operation as in Example 1'was performed , And carry out the measurement of pretilt angle and voltage retention rate.

As with the above results, it can be confirmed that, compared with Comparative Examples 1, 2, Comparative Examples 1'and 2', even Examples 1 to 7, 13, 14 and Examples 1'to 7', 13', 14' are When using a substrate with BCS, it can also show high VHR characteristics.

Furthermore, it can be seen from Examples 8, 9, and Examples 8'and 9'that even if a polymer that does not have a diamine containing a carboxyl group or a nitrogen-containing structure as a monomer unit is used in combination with a polymer that has the diamine as a monomer unit Polymers of monomer units can also exhibit high VHR characteristics. In addition, as shown in Examples 10 to 12 and Examples 10' to 12', the addition of a crosslinking agent to a polymer that exhibits high VHR characteristics even when using a substrate with BCS When exhibiting the same high VHR characteristics.

In addition, the entire contents of the specification, patent application scope, and abstract of Japanese Patent Application No. 2016-118281 filed on June 14, 2016 are incorporated herein as the disclosure of the specification of the present invention.

Claims (12)

A BOA substrate or a liquid crystal alignment agent for substrate coating with BCS, which is characterized by containing a polyimide selected from a polyimide precursor and a polyimide obtained by imidizing the polyimide precursor The polyimide precursor is obtained by reacting a diamine component containing a diamine with a tetracarboxylic dianhydride component, and the diamine is in a structure other than two amine groups. Containing nitrogen or a carboxylic acid group, the aforementioned diamine is at least one diamine selected from the group consisting of diamines of the following formulas (1), (4) to (8),

(In formula (1), X ¹ is a single bond, -O- _{, -CO-, -NH-, -N(CH 3} )-, -CONH-, -NHCO-, -CH ₂ O-, -OCO- , -CON(CH ₃ )- or N(CH ₃ )CO-, X ² is an alkyl group with 1 to 5 carbon atoms or a non-aromatic heterocyclic ring containing a nitrogen atom, and X ³ contains 1 or 2 nitrogen atoms A 5-membered ring or a 6-membered aromatic heterocyclic ring, which can be substituted by an alkyl group with 1 to 5 carbon atoms, n is an integer of 1 to 4)

(In formula (4), D represents a divalent saturated hydrocarbon group, unsaturated hydrocarbon group, aromatic hydrocarbon group or heterocyclic ring having 1 to 20 carbon atoms, D may have various substituents, m is 1 or 0, and the formula ( In 5), E is a single bond or a divalent saturated hydrocarbon group, unsaturated hydrocarbon group, aromatic hydrocarbon group or heterocyclic ring with a carbon number of 1 to 20, and F represents a single bond, -O-, -OCO- or COO-, the formula (6), a ₁ based single bond, selected from the group consisting of ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O- and OCO- group formed by the at least one kind of A divalent organic group or an alkylene group with 1 to 3 carbons, Q ¹ is a hydrogen atom or an alkyl group with 1 to 3 carbons, and R ₁₆ is a hydrogen atom or a monovalent organic group with 1 to 8 carbons. In (7), X ⁴ and X ⁸ are each independently a single bond, -CH ₂ -or -CH ₂ CH ₂ -, X ⁵ and X ⁷ are each independently -CH ₂ -or -CH ₂ CH ₂ -, X ⁶ is an alkylene or cyclohexylene having 1 to 6 carbon atoms, and Y ¹ is independently a single bond, -O-, -NH-, -N(CH ₃ )-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C(=O)N(CH ₃ )-, -OC(=O)-, -NHC(=O)- or -N( CH ₃ )C(=O)-, R ₁₇ are independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, benzyl or 9-茀基, a is 0 or 1)

(In formula (8), R ⁸ is a hydrogen atom, an alkyl group with 1 to 6 carbons, an aromatic group with 6 to 20 carbons, an alkyl group with 7 to 13 carbons, or 1,3-dioxobutyl , X ¹¹ is a single bond, a carbonyl group or *-CONH- (but the bonding part with "*" is bonded to the piperidine ring), R ₆ , R ₇ , R ₉ and R ₁₀ are each independently a carbon An alkyl group having 1 to 6, an aryl group having 6 to 12 carbons, or an aralkyl group having 7 to 13 carbons, but the benzene ring of the aforementioned aryl group and aralkyl group may be methylated or a carbon number of 1 to 4, X ⁹ , X ¹⁰ , X ¹² and X ¹³ are each independently a single bond, a carbonyl group, *-CH ₂ -CO- or *-CH ₂ -CH(OH)- (but with The bonding part of "*" is bonded to the piperidine ring), X ¹⁴ is independently -O-, *-OCO-, and ^{the group represented by the following formula (X 14} -1) (but with "*" The bonding part is bonded to the piperidine ring in formula (8)), methylene group or alkylene group with carbon number 2~6)

(In formula (X ¹⁴ -1), a is an integer of 1 to 12, and b is an integer of 0 to 5). The liquid crystal alignment agent of claim 1, wherein the aforementioned diamine component contains a diamine represented by the following formula (10) or (11),

(In formula (10), Y ¹ is a single bond, -(CH ₂ ) _a- (a is an integer from 1 to 15), -O-, -CH ₂ O-, -COO- or OCO-, Y ² is Single bond or (CH ₂ ) _b- (b is an integer from 1 to 15), Y ³ is a single bond, -(CH ₂ ) _c- (c is an integer from 1 to 15), -O-, -CH ₂ O -, -COO- or OCO-, Y ⁴ is a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on these cyclic groups can be Substitution by C1-C3 alkyl group, C1-C3 alkoxy group, C1-C3 fluorine-containing alkyl group, C1-C3 fluorine-containing alkoxy group or fluorine atom, or, Y ⁴ is a divalent organic group with a carbon number of 12 to 25 with a steroid skeleton. Y ⁵ is a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexyl ring and a heterocyclic ring. Any hydrogen atom on the group can be replaced by a C1-C3 alkyl group, a C1-C3 alkoxy group, a C1-C3 fluorine-containing alkyl group, and a C1-C3 fluorine-containing alkoxy group. Or substituted by a fluorine atom, n is an integer from 0 to 4, Y ⁶ is an alkyl group with 1 to 18 carbons, a fluorine-containing alkyl group with 1 to 18 carbons, an alkoxy group with 1 to 18 carbons, or a carbon number 1. ~18 fluorine-containing alkoxy group, m is an integer of 1~4)

(In formula (11), Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene. These can also be substituted by organic groups, and hydrogen atoms can also be halogen atoms. Substituted, R ₁ and R ₂ are each independently an alkyl group, alkoxy group, benzyl group or phenethyl group having 1 to 10 carbon atoms. If it is an alkyl group or alkoxy group, R ₁ and R ₂ can also be used To form a ring, T ₁ and T ₂ are independently single bonds or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO- bonding group, S is a single bond or unsubstituted or substituted by a fluorine atom and a C 1-20 alkylene group (but The -CH ₂ -or CF ₂ -of the alkylene group can be optionally substituted by -CH=CH-, and when any of the groups listed below are not adjacent to each other, they can also be substituted by these groups:- O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocyclic or divalent heterocyclic ring), Q represents the following structure,

(In the formula, R is independently represented by a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₃ is represented by -CH ₂ -, -NR-, -O- or S-). The liquid crystal alignment agent of claim 1, wherein the aforementioned tetracarboxylic dianhydride component is selected from at least one tetracarboxylic dianhydride selected from the group consisting of the following formulas (12) to (14),

(In formula (12), Z ¹ is a tetravalent organic group with 4 to 13 carbons and a non-aromatic cyclic hydrocarbon group with 4 to 10 carbons. In formula (13) or (14), j and k is each independently 0 or 1, and X and y are each independently a single bond, a carbonyl group, an ester group, a phenylene group, a sulfonyl group, or a amide group). The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the liquid crystal alignment agent includes a polymer other than the polyimide precursor, or includes the polyimide precursor being imidized And the obtained polymer other than polyimide. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the aforementioned liquid crystal alignment agent further includes at least one selected from the group consisting of adhesion assistants, crosslinking agents, dielectrics, conductive substances, and organic solvents 1 kind. The liquid crystal alignment agent of claim 5, wherein the crosslinking agent is a compound selected from at least one of the following formula (17), formula (19) and formula (21),

(In formula (17), R ₂₀ , R ₂₁ , R ₂₅ and R ₂₆ are each independently a hydrogen atom, an alkyl group with 1 to 4 carbons, an alkenyl group with 2 to 4 carbons, or an alkyne with 2 to 4 carbons. And at least one of them is a group represented by formula (18), R ₂₂ and R ₂₄ are each independently represented as an aromatic ring, and any hydrogen atom of the aromatic ring can be replaced by a hydroxyl group, an alkyl group having 1 to 3 carbon atoms, It is substituted by halogen atom, alkoxy group with 1 to 3 carbons or vinyl group, R ₂₃ is a single bond, all or part of it can be bonded to form a saturated hydrocarbon group with 1 to 10 carbons in a cyclic structure)

(In formula (19), R ₂₇ is an aliphatic hydrocarbon group with 1 to 20 carbons or an n-valent organic group containing an aromatic hydrocarbon group, c is an integer of 2 to 6, and R ₂₈ and R ₂₉ are each independently a hydrogen atom , Alkyl groups with 1 to 4 carbons, alkenyl groups with 2 to 4 carbons, or alkynyl groups with 2 to 4 carbons. These groups may have substituents. However, at least one of _{R 28} and R _{29 has} (Hydroxyl as a substituent)

(In formula (21), R ₃₄ and R ₃₈ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbons, and R ₃₅ and R ₃₇ are each independently an aromatic ring, and any hydrogen atom of the aromatic ring can be Substituted by a hydroxyl group, an alkyl group with 1 to 3 carbons, a halogen atom, an alkoxy group with 1 to 3 carbons or a vinyl group, R ₃₆ is a single bond, and all or part of it can be bonded to form a ring structure carbon A saturated hydrocarbon group with a number of 1 to 10 and any hydrogen atom can be replaced by a fluorine atom, -NH-, -N(CH ₃ )- or the group represented by formula (22), in formula (22), P ₁ and P ₂ series are each independently an alkyl group with 1 to 5 carbon atoms, Q ₁ series represents an aromatic ring), and in formula (21), d and f are each independently an integer of 1 to 3, and e and g are each independently An integer from 1 to 3). The liquid crystal alignment agent of claim 6, wherein _{at least one of the aforementioned R 28} and R ₂₉ is substituted with a group represented by the following formula (20). In the formula (20), R ₃₀ to R ₃₃ are each independently Is a hydrogen atom, a hydrocarbon group, or a hydrocarbon group substituted by a hydroxyl group,

The liquid crystal alignment agent of claim 6, wherein the crosslinking agent is at least one compound selected from the group consisting of the following formulas CL-1 to CL-3,

The liquid crystal alignment agent of claim 7, wherein the aforementioned crosslinking agent is selected from at least one compound selected from the group consisting of the following formulas CL-1 to CL-3,

A liquid crystal display element is provided with a BOA substrate or a BCS-attached substrate, and the substrates are formed with a liquid crystal alignment film obtained from the liquid crystal alignment agent of any one of claims 1-9. A method for manufacturing a liquid crystal alignment film on a BOA substrate or a substrate with BCS, which is to apply the liquid crystal alignment agent of any one of claims 1 to 9 to a BOA substrate or a substrate with BCS. A substrate for a liquid crystal display element, which is provided with: a BOA substrate or a substrate with BCS; and a liquid crystal alignment agent according to any one of claims 1 to 9 and formed on the aforementioned BOA substrate or a substrate with BCS Liquid crystal alignment film.