JP2000204250A - Liquid crystal alignment agent and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal alignment agent which is excellent in jetting stability in applying to a substrate by ink jet printing and gives a liquid crystal alignment layer having a uniform thickness by incorporating a block copolymer containing polyimide blocks and polyamic acid blocks into the same. SOLUTION: This agent contains a block copolymer comprising polyimide blocks and polyamic acid blocks. The polyimide block comprises at least one kind of repeating units selected from among repeating units represented by formulas I and I. The polyamic acid block comprises at least one kind of repeating units selected from among repeating units represented by formulas III and IV. In the formulas, R1, R4, and R6 are each H or alkyl; R2, R3, R5, and R7 are each a divalent organic group; 1 is 1-4; and n, m, q, and p are each a positive number, The agent can quite satisfy the pretilt angle, voltage retention, and residual image characteristics required of liquid crystal display elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal alignment agent suitable as a liquid crystal alignment film forming agent and a liquid crystal display device using the same. More specifically, the present invention provides a liquid crystal aligning agent which exhibits excellent application stability and film thickness uniformity when applied to a substrate by an inkjet printing method by containing a block copolymer having a specific structure, and uses the same. Liquid crystal display device.

[0002]

2. Description of the Related Art At present, as a liquid crystal display element, a liquid crystal alignment film made of polyimide or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a substrate for the liquid crystal display element. For example, a nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap to form a cell having a sandwich structure, and the major axis of the liquid crystal molecule is continuously arranged from one substrate toward the other substrate. So-called TN (Twisted Nemat)
An TN type liquid crystal display device having an ic) type liquid crystal cell is known. A so-called TFT liquid crystal panel in which this TN type liquid crystal display element is operated by TFT driving is becoming widespread instead of a conventional cathode ray tube monitor. In this liquid crystal element, the liquid crystal alignment film controls the alignment of the liquid crystal. The liquid crystal alignment film is formed by applying and baking a polyamic acid solution as a polyimide precursor or a polyimide solution soluble in a solvent to a substrate by flexographic printing.

[0003] However, recently, the inkjet printing method has attracted attention because the complexity of the maintenance of the printing plate has been regarded as a problem in the flexographic printing method, for example, the printing plate has to be changed according to the substrate. The ink-jet method has advantages such as free maintenance of a printing plate, free setting of a printing pattern, and a small amount of a liquid crystal aligning agent solution, and is expected to reduce the cost of a liquid crystal panel and improve the yield.

[0004]

The ink-jet printing method has the above-mentioned advantages, but a liquid crystal aligning agent suitable for this has not yet been proposed, and is used in conventional polyimides and polyamic acids. There has been a problem that a stable printing state cannot be maintained from the viewpoints of damage to the ink jet printer due to the solvent, viscosity characteristics of the polyimide and polyamic acid solutions, and the like.

(1) In the ink jet printing method,
It is necessary to eject a liquid crystal aligning agent from a fine nozzle at a high speed, and the viscosity characteristics of the liquid crystal aligning agent is an important factor. That is, the resistance when a strong external force is applied to the solution is small and the fluidity is excellent. Further, in some cases, an organic material is used for the nozzle member, and the liquid crystal alignment agent is
It is also important not to violate this organic material, and it is necessary to reduce the content of a highly soluble solvent such as N-methylpyrrolidone which has been conventionally used as a solvent for a liquid crystal aligning agent. From such a viewpoint, it is considered that a polyamic acid-based material having high solubility in various solvents is suitable.

(2) On the other hand, the required performance as a liquid crystal alignment film is becoming more and more advanced, and there is a trade-off between a single material such as a high voltage holding ratio, a high pretilt angle, and a low residual DC. Has become. As a means for solving these trade-offs, a technique of mixing a polyamic acid which excels in low residual DC with a polyimide excels in high voltage holding ratio and high pretilt angle is known.

[0007] From the above situations (1) and (2), the fluidity,
Polyamic acid and polyimide composite with excellent solubility,
It is expected to be suitable for inkjet printing. However, according to the research of the present inventor, if polyamic acid and polyimide were simply mixed, they were separated by shear or heat at the time of ink-jet printing, causing jetting stability, a cause of lack of performance stability as a liquid crystal alignment film. It was clear that it would be. Therefore, in the present invention, by combining a polyamic acid containing a specific structure and a polyimide using a method of block copolymerization, the jetting stability, the performance stability of the liquid crystal alignment film, and the stability to an ink jet device are excellent. Succeeded in producing a liquid crystal alignment agent.

That is, an object of the present invention is to provide a novel liquid crystal aligning agent and a liquid crystal display device using the same. Another object of the present invention is to provide a liquid crystal aligning agent containing a block copolymer consisting of a polyamic acid block and a polyimide block, and a liquid crystal display device using the same. Still another object of the present invention is to provide a liquid crystal aligning agent excellent in ejection stability, performance stability of a liquid crystal alignment film, and stability to an ink jet device, and a liquid crystal display device using the same. Still other objects and advantages of the present invention will become apparent from the following description.

[0009]

According to the present invention, the above objects and advantages of the present invention are attained by a block copolymer comprising a first polyimide block and a second polyamic acid block in a molecule. The first polyimide block has the following formula (1)

Embedded image Here, R ¹ represents a hydrogen atom or an alkyl group, R ² represents a divalent organic group, 1 represents an integer of 1 to 4, and n represents
Represents the number of repeating units and is a positive number, and a repeating unit represented by the following formula (2):

Embedded image Here, R ³ is a divalent organic group, and m represents the number of repeating units and is a positive number, containing at least one type of repeating unit selected from the group consisting of: And the second polyamic acid block has the following formula (3)

Embedded image Here, R ⁶ represents a hydrogen atom or an alkyl group, R ⁷ represents a divalent organic group, and q represents the number of repeating units and is a positive number, and the following formula (4) )

Embedded image Here, R ⁴ represents a hydrogen atom or an alkyl group, R ⁵ represents a divalent organic group, and p represents a repeating unit and is a positive number, and is selected from the group consisting of: This is achieved by a liquid crystal aligning agent characterized by containing a block copolymer containing at least one type of repeating unit.

Hereinafter, the present invention will be described specifically.
The liquid crystal aligning agent of the present invention comprises a first polyimide block having a repeating unit represented by the above formula (1) and / or formula (2) and the above formula (3) and / or formula (4) bonded thereto. And a block copolymer comprising a second polyamic acid block having a repeating unit represented by

In the above formula (1), R ¹ is a hydrogen atom or an alkyl group. The alkyl group may be linear or branched, and is preferably an alkyl group having 1 to 30 carbon atoms. R ² is a divalent organic group, preferably a divalent alicyclic group or a divalent aromatic group. Examples of the divalent alicyclic group or the divalent aromatic group include, for example, a divalent residue obtained by removing an amino group from an alicyclic diamine or an aromatic diamine described below. The number n of repeating units is preferably usually 3 to 2,000.
0, more preferably 3 to 100.

In the above formula (2), R ³ is a divalent organic group, preferably a divalent alicyclic group or a divalent aromatic group. Specific examples of these may include the same as that of the R ^2. The number m of repeating units is preferably from 3 to 2,000, more preferably from 3 to 2,000.
100.

In the above formula (3), R ⁶ is a hydrogen atom or an alkyl group. The alkyl group may be linear or branched, and preferably has 1 to carbon atoms.
And 30 alkyl groups. R ⁷ is a divalent organic group, preferably a divalent alicyclic group or a divalent aromatic group. Examples of the divalent alicyclic group or the divalent aromatic group include a divalent residue obtained by removing an amino group from an alicyclic diamine or an aromatic diamine described below. The number q of repeating units is preferably 2 to 1,0.
00, more preferably 2 to 100.

Further, in the formula (4), R ⁴ is a hydrogen atom or an alkyl group. The alkyl group may be linear or branched, and preferably has 1 to 30 carbon atoms.
Can be mentioned.

R ⁵ is a divalent organic group, preferably
A divalent alicyclic group or a divalent aromatic group; Specific examples of these may include the same as those of the R ^7. The number p of repeating units is preferably 2 to 1,000.
0, more preferably 2 to 100.

Furthermore, the weight ratio of the first polyimide block in the block copolymer ([rho ₁₎ the weight ratio of the second polyamic acid block ([rho ₂₎ is preferably [rho ₁ <[rho _2, When ρ ₁ > ρ ₂ , the viscosity at a high share is too large to be suitable for ink-jet coating, and the leveling property is poor even in a normal flexographic printing method, and the film thickness uniformity may be poor.

<Method for Producing Block Copolymer> Next, a method for producing the block copolymer of the present invention will be described.
The block copolymer of the present invention is a “step A” for preparing a polyamic acid prepolymer (A) having an amino group at a molecular terminal, a polyimide prepolymer having a reactive group derived from a tetracarboxylic acid at a molecular terminal. (B)
And a "step C" of reacting the polyamic acid prepolymer (A) with the polyimide prepolymer (B). Further, it is possible to obtain a block copolymer of the present invention from a polyamic acid prepolymer having a tetracarboxylic acid terminal and a polyimide prepolymer having an amino group terminal, but the number of repeating units of the prepolymer tends to change with time. For this reason, the methods of Steps A, B and C are preferred. Hereinafter, steps A, B, and C will be described as examples.

Step A: In this step A, a tetracarboxylic acid having an organic group RA is reacted with a diamine having an organic group QA as shown in the following reaction formula 1. With respect to the number of moles of the tetracarboxylic acid used, the diamine is used in an excess amount exceeding the equimolar amount so that the number of moles is, for example, 1.001 to 2 times, thereby having an amino group at the molecular terminal. A polyamic acid prepolymer (A) having a repeating unit number β is prepared.

[0019]

Embedded image

Step B: In this step B, a tetracarboxylic acid having an organic group RB is reacted with a diamine having an organic group QB as shown in the following reaction formula 2. The tetracarboxylic acid is derived from tetracarboxylic acids at the molecular terminal by using an excess amount exceeding the equimolar amount so that the molar number is, for example, 1.001 to 2 times the molar number of the diamine used. A polyamic acid having a reactive group is prepared. Next, an imidization treatment described later is performed to obtain a polyimide prepolymer (B) having a repeating unit number α.

[0021]

Embedded image

Step C: In this step C, the terminal amino group of the polyamic acid prepolymer (A) obtained in step A and the terminal tetracarboxylic acid of the polyimide prepolymer (B) obtained in step B By reacting with a reactive group derived in the same manner as in step A or step B,
As shown in Reaction Scheme 3, the organic group QA bonded to the nuclear atom group RA via a divalent bonding group (—CO—NH—)
Block copolymer formed by bonding a polyamic acid block (A) having a conjugate of the above as a repeating unit and a polyimide block (B) having a conjugate of a similar nuclear group RB and an organic group QB as a repeating unit. Manufacturing coalescence.

[0023]

Embedded image

In the step C, the obtained block copolymer can be converted into a terminal-modified block copolymer having a controlled molecular weight by the following method. This terminal-modified block copolymer can be used for improving coating characteristics and the like. Such a terminal-modified type can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound, or the like to the reaction system in Step C. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-
Decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride,
and n-hexadecyl succinic anhydride. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine,
n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n
-Decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n -Eicosylamine, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltri Ethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl)-
3-aminopropylmethyldimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropylmethyldiethoxysilane, p- [N- (2-aminoethyl) aminomethyl] phenethyltrimethoxysilane,
N, N-bis [3- (trimethoxysilyl) propyl]
Examples include ethylenediamine, N-3-trimethoxysilylpropyl-m-phenylenediamine and the like. Examples of the monoisocyanate compound include phenyl isocyanate, naphthyl isocyanate, and 3
-Isocyanatopropyltriethoxysilane and the like.

As the tetracarboxylic acid and diamine used in the step A or the step B, a plurality of compounds among the following compounds can be used in combination. In addition, one or more of the polyamic acid prepolymer and / or the polyimide prepolymer produced in the same manner as in the step A or the step B is reacted in the step C or in the same manner as in the step C. Thus, a block copolymer including three or more types of blocks can be produced.

Specific examples of the tetracarboxylic dianhydride used in Step A include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,
4-cyclobutanetetracarboxylic dianhydride, 1,3-
Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4
-At least one selected from cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride can be preferably used.

Specific examples of the tetracarboxylic dianhydride used in the step B include 1,3,3a, 4,5,9b
-Hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,
3-dione, 1,3,3a, 4,5,9b-hexahydro-
5-methyl-5 (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 1,3,3a, 4,5,9b-hexahydro-5-
Ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7- Methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-7-ethyl-
5 (tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione, 1,
3,3a, 4,5,9b-Hexahydro-8-methyl-5
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] -furan-1,3-dione, 1,3,
3a, 4,5,9b-Hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3, 3
a, 4,5,9b-Hexahydro-5,8-dimethyl-5
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] -furan-1,3-dione, 2,3,
At least one selected from 5-tricarboxycyclopentylacetic acid dianhydride can be preferably used.
In step A and step B, these acid dianhydrides and tetracarboxylic acid dianhydrides described below are used in a range that does not impair the characteristics of the present invention, preferably in an amount of 20 mol% or less of the total tetracarboxylic dianhydrides. An anhydride can be used in combination.

Examples of the tetracarboxylic anhydride used in combination in step A and / or step B include the following alicyclic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides. it can. In the step A, the tetracarboxylic dianhydride exemplified as the one used in the step B was used, and in the step B, the tetracarboxylic dianhydride exemplified as the one used in the step A was used in an amount of 20 mol%. The following amounts may be used.

As the alicyclic tetracarboxylic dianhydride, for example, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetraanhydride Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,
4'-dicyclohexyltetracarboxylic dianhydride,
3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl- 3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-
7-ene-2,3,5,6-tetracarboxylic dianhydride,
Examples include compounds represented by the following formulas (5) and (6).

[0030]

Embedded image (Wherein, R ₁ and R _{3 each} represent an aromatic divalent organic group, R ₂ and R _{4 each} represent a hydrogen atom or an alkyl group, and a plurality of R ₂ and R ₄ may be the same or different. May be)

Examples of the aromatic tetracarboxylic dianhydride include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride. 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylethertetracarboxylic dianhydride Anhydride, 3,3 ',
4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride
4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride,
3 ', 4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p -Phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (tri Phenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimeritate) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydroto Rimellitate),
2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate) represented by the following formulas (7) to (1)
0) and the like.

[0032]

Embedded image

Examples of the diamine compound used in the step A and / or the step B include an aliphatic diamine compound and an aromatic diamine compound.
Examples of the aliphatic diamine compound include 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, Aliphatic diamines, such as, 4-diaminoheptamethylenediamine;
1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine,
Hexahydro-4,7-methanoindanylene dimethylene diamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyl diamine, 4,4'-methylene bis (cyclohexylamine), 1,3-bisaminomethylcyclohexane 2,5-bis (aminomethyl) bicyclo [2.
2.1] heptane, alicyclic diamines such as 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane; and diaminoorganosiloxanes represented by the following formula (11).

[0034]

Embedded image (Wherein, R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ⁹ may be the same or different, r is an integer of 1 to 3, and s is 1 to 20. Is an integer.)

As the aromatic diamine compound, p-phenylenediamine, m-phenylenediamine, 4,4'-
Diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 4,4'-
Diaminodiphenyl ether, 3,5-diaminobenzoic acid, 1-hexadecanoxy-2,4-diaminobenzene, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4 ′ -Diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl,
5-amino-1- (4'-aminophenyl) -1,3,3
-Trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane,
4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,1,3,3,3-hexafluoropropane, 2-bis [4- (4-aminophenoxy)
Phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy)
Benzene, 9,9-bis (4-aminophenyl) -10
-Hydroanthracene, 2,7-diaminofluorene,
9,9-bis (4-aminophenyl) fluorene,
4'-methylene-bis (2-chloroaniline), 2,
2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,
5'-dimethoxybiphenyl, 3,3'-dimethoxy-
4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4 '-(p-phenylenediisopropyl Riden) dianiline, 4,4'-
(M-phenylenediisopropylidene) dianiline,
2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4 '-Bis [(4-amino-
Aromatic diamines such as 2-trifluoromethyl) phenoxy] -octafluorobiphenyl; 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6- Diamino-2,3-dicyanopyrazine, 5,6-diamino-2,
4-dihydroxypyrimidine, 2,4-diamino-6
Dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4
-Diamino-6-methoxy-1,3,5-triazine,
2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine,
2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine,
5,6-diamino-1,3-dimethyluracil, 3,5-
Diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-
Aminophenyl) phenylamine and the following formula (12)
(1) such as compounds represented by (13)
A diamine having a primary amino group and a nitrogen atom other than the primary amino group;

[0036]

Embedded image (Wherein R ¹⁰ is pyridine, pyrimidine, triazine,
X represents a monovalent organic group having a ring structure containing a nitrogen atom selected from piperidine and piperazine, and X represents a divalent organic group. )

[0037]

Embedded image Wherein R ¹¹ is pyridine, pyrimidine, triazine,
X represents a divalent organic group having a ring structure containing a nitrogen atom selected from piperidine and piperazine; X represents a divalent organic group; and a plurality of Xs may be the same or different. )

Monosubstituted phenylenediamines represented by the following formula (14):

[0039]

Embedded image (Wherein R ¹² represents —O—, —COO—, —OCO—,
R ¹³ represents a divalent organic group selected from NHCO—, —CONH—, and —CO—, and R ¹³ is a monovalent organic group having a steroid skeleton, a trifluoromethyl group, or a group selected from a fluoro group, or a carbon number of 6; Represents up to 30 alkyl groups. )

Compounds represented by the following formulas (15) to (27) can be mentioned. These diamine compounds can be used alone or in combination of two or more.

[0041]

Embedded image (In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)

[0042]

Embedded image

Of these, 1,4-diaminocyclohexane, isophoronediamine, 1-hexadecanoxy-
2,4-diaminobenzene, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene dimethylenediamine, tricyclo [6.2.
1.0 ^2,7 ] -undecylenedimethyldiamine, 4,4 '
-Methylenebis (cyclohexylamine), 1,3-bisaminomethylcyclohexane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2. 1 "] heptane,
4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,5-diaminobenzoic acid, 2,2-bis (4-aminophenyl) -1,1, 1,3,3,3-hexafluoropropane, p-phenylenediamine, 4,4 ′
-Diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,4- Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl)-
10-hydroanthracene, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene,
3,3′-dimethoxy-4,4′-diaminobiphenyl,
4,4 ′-(p-phenylenediisopropylidene) dianiline, 4,4 ′-(m-phenylenediisopropylidene) dianiline, 1,1-metaxylylenediamine, 1,
3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, represented by the above formulas (15) to (27) Are preferred. These diamines can be used alone or in combination of two or more.

The reactions in Steps A, B and C are carried out in an organic solvent at a temperature of preferably 0 to 200 ° C, more preferably 0 to 100 ° C. The organic solvent used in this reaction is not particularly limited as long as it can dissolve the generated polyamic acid, and examples thereof include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, Aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol, and halogenated phenol. The amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic acids and the diamine is 0.1 to 30% by weight based on the total amount of the reaction solution. In this organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons, which are poor solvents, may be used together in such a proportion that the generated polyamic acid prepolymer does not precipitate. it can. Examples of such poor solvents include ethyl alcohol, cyclohexanol, propylene glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone,
Cyclohexanone, ethyl acetate, butyl acetate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-propyl ether, ethylene glycol ethyl ether acetate, tetrahydrofuran, dichloroethane, chlorobenzene, hexane, heptane,
Examples include toluene and xylene.

The imidization reaction in the step B is represented by the following reaction formula 2.
Is carried out by dissolving an intermediate product (polyamic acid) in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, and heating as necessary. In addition, by selecting the conditions for the dehydration ring-closing reaction in step B, a polyimide that has been partially dehydrated and ring-closed can also be suitably used. As the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the repeating unit of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the dehydration ring closure reaction, the organic solvents exemplified above can be exemplified. The reaction temperature of the dehydration ring closure reaction is usually 0 to 18
0 ° C, preferably 10 to 150 ° C.

Since these block copolymers are obtained by combining two or three or more kinds of polyimide-based blocks and polyamic acid-based blocks having different structures from each other, they are basically used. The polyamic acid or polyimide has inherent characteristics as well as a plurality of types of characteristics of the polyamic acid or polyimide homopolymer of each block.
That is, for example, when the first polyimide component and the second polyamic acid component coexist as a block in the molecule, the first property of the polyimide homopolymer constituting the first block and the second property Second of the polyamic acid homopolymer constituting the block of
And at the same time. Alternatively, the properties of the block copolymer are such that the properties of the homopolymer of polyimide constituting a certain block are modified by the properties of the homopolymer of polyamic acid constituting another block. it can.

Such characteristics cannot be obtained by a mere mixture of the first polyimide and the second polyamic acid, and are not used for obtaining the first polyimide and the second polyamic acid. It cannot be obtained even when all of the obtained tetracarboxylic acids and diamine are reacted, for example, collectively. That is, it can be said that the block copolymer of the present invention is a copolymer having both of a plurality of good properties, which is difficult to obtain simultaneously by ordinary means.

The properties of the block copolymer of the present invention are determined by the structure of the repeating unit in each block constituting the block copolymer and the number of repeating units or the ratio thereof. Therefore, by controlling these factors, it is possible to control the characteristics of the polyimide block copolymer finally obtained.

That is, by selecting the type of tetracarboxylic acid and diamine to be used for producing each block, and adjusting the amount or ratio of use thereof, the number of blocks to constitute the obtained block copolymer is obtained. By controlling each kind and their ratio, it is possible to control the properties of the finally obtained block copolymer.

<Liquid Crystal Alignment Agent> Next, a liquid crystal alignment agent using the above block copolymer will be described. The content ratio of the block polymer in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like. To 10% by weight. That is, a liquid crystal aligning agent composed of a polymer solution is applied to the substrate surface by a printing method, a spin coating method or the like, and then dried to form a film as an alignment film material. If the proportion is less than 0.1% by weight, the film thickness of this film may be too small to obtain a good liquid crystal alignment film. When the thickness is too large, it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent is increased, which may result in poor coating characteristics.

The liquid crystal aligning agent used in the present invention comprises:
Although it is characterized by containing a block copolymer having a specific structure, a polyamic acid and / or a polyimide having another structure can be mixed and used as long as the effects of the present invention are not impaired.

The organic solvent for dissolving the polymer is not particularly limited as long as it can dissolve the polymer, and examples thereof include the solvents exemplified as those used in the polyamic acid synthesis reaction and the dehydration ring closure reaction. be able to. In addition, the poor solvents exemplified as those which can be used together in the synthesis reaction of the polyamic acid can be appropriately selected and used in combination. When the liquid crystal aligning agent of the present invention is applied by an inkjet method, the content of N-methylpyrrolidone is desirably set to 20% by weight or less of the total solvent amount from the viewpoint of suppressing damage to device members.

The liquid crystal aligning agent used in the present invention may contain a functional silane-containing compound or an epoxy compound from the viewpoint of further improving the adhesiveness between the polymer and the substrate surface to be coated. Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane,
3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylene Triamine, N-trimethoxysilylpropyltriethylenetriamine, 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, and the like.

Examples of the epoxy group-containing compound include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and neopentyl glycol diglycidyl ether. 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2
-Dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N',-tetraglycidyl-m-
Xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) Aminopropyltrimethoxysilane, 3- (N, N-diglycidyl)
Aminopropyltrimethoxysilane and the like can be mentioned as preferred. Of these, in the molecule,
Compounds having a tertiary nitrogen atom are preferred. The compounding ratio of these compounds is usually based on 100 parts by weight of the polymer.
It is 40 parts by weight or less, preferably 0.1 to 30 parts by weight.

<Liquid crystal display element> The liquid crystal display element of the present invention obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method.

(1) A liquid crystal aligning agent is applied to the transparent conductive film side of the substrate provided with the patterned transparent conductive film by, for example, a roll coater method, a spinner method, a printing method, or the like, and then the coated surface is coated. A film is formed by heating. Here, as the substrate, for example, a transparent substrate made of glass such as float glass or soda glass, or a plastic film such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used. As the transparent conductive film provided on one surface of a substrate, for example, NESA film made of SnO _2, ITO consisting of In ₂ O ₃ -SnO ₂
A film or the like can be used. For the patterning of these transparent conductive films, a photo-etching method, a method using a mask in advance, or the like is used.

In applying the liquid crystal aligning agent, a functional silane-containing compound, titanate, or the like is previously applied onto the substrate and the transparent conductive film in order to further improve the adhesion between the substrate and the transparent conductive film. You can also. Flexo printing has been mainly used as a coating method, but the liquid crystal aligning agent of the present invention can be applied not only by flexographic printing but also by inkjet printing.
The drying temperature of the coating is preferably from 80 to 250C, more preferably from 120 to 200C. The film thickness of the formed film is usually 0.001 to 1 μm, preferably 0.005 to 0.5 μm.

The formed film is subjected to a rubbing treatment in which the surface of the film is rubbed in a certain direction with a roll around which a cloth made of, for example, nylon, rayon, cotton, or the like is wound, thereby imparting the film with the ability to align liquid crystal molecules. Thus, a liquid crystal alignment film is formed. In addition, in order to remove the fine powder (foreign matter) generated at the time of the rubbing treatment and to make the coating surface clean,
It is preferable to wash the formed liquid crystal alignment film with isopropyl alcohol or the like. In addition to the method using a rubbing treatment, the coating surface is irradiated with polarized ultraviolet rays, an ion beam, an electron beam, or the like to impart orientation ability, or a uniaxial stretching method, a method for obtaining a coating by a Langmuir-Blodgett method, or the like. Alternatively, a liquid crystal alignment film can be formed.

Further, the liquid crystal alignment film formed by the above-described processing is applied to, for example, JP-A-8-234207 and JP-A-7-234207.
As disclosed in JP-A-168187, JP-A-6-222366 or JP-A-6-281937, the pretilt angle is changed by partially irradiating an ultraviolet ray, an ion beam or an electron beam. A resist film is partially formed on the liquid crystal alignment film having been subjected to the above alignment treatment as described in JP-A-5-107544, and the resist film is formed in a direction different from the preceding liquid crystal alignment direction. After performing the alignment process, the visibility characteristics of the liquid crystal display element can be improved by a method of removing the resist film and performing a process of changing the alignment ability of the liquid crystal alignment film.

(3) Two substrates on which a liquid crystal alignment film is formed as described above are prepared, and the two substrates are set so that the directions of the pretilt angles in each liquid crystal alignment film are orthogonal or antiparallel. The two substrates are opposed to each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are bonded to each other with a sealant. The liquid crystal is filled into the surface of the substrate and the cell gap defined by the sealant, and the filling hole is sealed. To form a liquid crystal cell. Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell,
A liquid crystal display device is obtained by laminating the substrate so that its polarization direction matches or is perpendicular to the liquid crystal alignment direction of the liquid crystal alignment film formed on one surface of the substrate. As the sealant, for example, an epoxy resin containing a hardening agent and aluminum oxide spheres as a spacer can be used.

Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, nematic liquid crystals are preferable. Liquid crystal, cubane liquid crystal, and the like are used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and chiral agents sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co.) It can also be used by adding it. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can be used.

As a polarizing plate used outside the liquid crystal cell, a polarizing plate or a H film in which a polarizing film called an H film in which polyvinyl alcohol is stretched and oriented and iodine is absorbed and sandwiched by a cellulose acetate protective film is used. And a polarizing plate composed of the same.

[0063]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The properties of the liquid crystal aligning agents produced by the following examples and comparative examples, and performance evaluation methods when used for liquid crystal display devices are shown below.

[Solubility of Block Copolymer] To 50 g of a liquid crystal aligning agent prepared as a γ-butyrolactone solution having a solid content of 4% by weight, butyl cellosolve as a poor solvent was added until a precipitate was formed. Was added as an index of solubility. The larger the amount added, the better the solubility.

[Inkjet Coating Properties] The liquid crystal aligning agent was adjusted to an ITO substrate by using a JET-CM continuous ink jet printer (manufactured by Kishu Giken Kogyo Co., Ltd.) using the aligning agent solution adjusted to a solid concentration of 2% by weight. Dry film thickness is 800
An amount of Angstrom was applied. Then 180
° C, and measure the unevenness of the dried film with a stylus-type film thickness meter.
The difference between the maximum film thickness and the minimum film thickness was regarded as the film thickness uniformity and evaluated.
In addition, the stability of printing was evaluated by comparing the film thickness uniformity at the start of ink-jet coating and at the time of continuous application for 5 hours, and the case where the difference between the start and 5 hours after was not more than 50 angstroms was regarded as good. .

[Orientation of Liquid Crystal] The presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element was observed with a microscope, and the case where there was no abnormal domain was judged as “good”.

[Pretilt Angle of Liquid Crystal Display Element]
Schffer, et. Al., J. Appl. Phys., V
ol. 19, 2013 (1980) ", and measured by a crystal rotation method using a He-Ne laser beam.

[Voltage holding ratio of liquid crystal display element] After applying a voltage of 5 V to the liquid crystal display element for an application time of 60 microseconds and a span of 500 milliseconds, the voltage holding ratio 500 milliseconds after the application was canceled was measured. did. The measurement was performed at 60 ° C. using VHR-1 manufactured by Toyo Corporation.

[Afterimage erasing time of liquid crystal display element] After applying a DC voltage of 20 V to the liquid crystal display element for 24 hours, the voltage is turned off.
F, the time until the afterimage disappeared was visually measured.

Synthesis Example 1 <Step A> Preparation of polyamic acid prepolymer Pyromellitic dianhydride 64.14 g, 1,2,3,4-cyclobutanetetracarboxylic dianhydride 134.56 and 4,4′- 198.27 g of diaminodiphenylmethane was dissolved in 1600 g of N-methyl-2-pyrrolidone, and the solution was reacted at 20 ° C. for 6 hours. Then, the obtained reaction solution is poured into a large excess of acetone to precipitate the reaction product, and the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln) of 1.8 dl / g. Polyamic acid prepolymer having an amino group at a molecular terminal (A
-1) 400.3 g was obtained.

<Step B> Preparation of Polyimide Prepolymer 1,3,3a, 4,5,9b-Hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione 14
6.48 g, 46.56 g of p-phenylenediamine and 6.96 g of the compound represented by the above formula (16) are dissolved in 800 g of N-methyl-2-pyrrolidone.
The reaction was performed at 0 ° C. for 26 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product (polyamic acid prepolymer). 120.0 g of the obtained polyamic acid prepolymer was used in γ-butyrolactone 60.
0 g, pyridine 44 g and acetic anhydride 56 g
Was added and the mixture was subjected to dehydration ring closure at 60 ° C. for 2 hours. Then, by performing precipitation, separation, washing and drying of the reaction product,
Logarithmic viscosity (ηln) 0.76 dl / g, imidization ratio 90
% Of a polyimide prepolymer (B-1) having an acid anhydride group at a molecular terminal was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 80 g and 20 g of the polyimide prepolymer (B-1) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 7 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 20 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (1) was 1.64 dl / g.

Synthesis Example 2 <Step A> Preparation of Polyamic Acid Prepolymer A polyamic acid prepolymer (A-1) was obtained in the same manner as in Step A of Synthesis Example 1.

<Step B> Preparation of Polyimide Prepolymer The raw materials used for the synthesis were 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] furan-1,3-dione 132.31 g, 4,4′-diaminodiphenylmethane 11.92 g, p-phenylenediamine 30.35 g and a compound represented by the above formula (20) 2
The reaction was carried out in the same manner as in Step B of Synthesis Example 1 except that the amount was changed to 5.4 g, and a polyimide prepolymer having an acid anhydride group at the molecular terminal with a logarithmic viscosity (ηln) of 0.73 dl / g and an imidation ratio of 94% was used. 25.3 g of a polymer (B-2) was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 80 g and 20 g of the polyimide prepolymer (B-2) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 7 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 20 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (2) was 1.65 dl / g.

Synthesis Example 3 <Step A> Preparation of Polyamic Acid Prepolymer A polyamic acid prepolymer (A-1) was obtained in the same manner as in Step A of Synthesis Example 1.

<Step B> Preparation of Polyimide Prepolymer 1,3,3a, 4,5,9b-Hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione 26
7.16 g, 2,3,5-tricarboxycyclopentylacetic acid dianhydride 33.63 g, p-phenylenediamine 7
2.1 g, 4,4'-diaminodiphenylmethane 47.2
1 g and 24.9 g of the compound represented by the above formula (16)
Is dissolved in 1800 g of N-methyl-2-pyrrolidone,
This solution was reacted at 20 ° C. for 26 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product (polyamic acid prepolymer). 30.0 g of the obtained polyamic acid prepolymer was dissolved in 150 g of γ-butyrolactone, 11 g of pyridine and 14 g of acetic anhydride were added, and the mixture was dehydrated and closed at 60 ° C. for 2 hours. Next, the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln) of 0.66 dl / g.
29.3 g of a polyimide prepolymer (B-3) having an acid anhydride group at the molecular terminal and having an imidation ratio of 90% was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 80 g and 20 g of the polyimide prepolymer (B-3) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 6 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 20 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (3) was 1.61 dl / g.

Synthesis Example 4 <Step A> Preparation of Polyamic Acid Prepolymer In the same manner as in Step A of Synthesis Example 1, a polyamic acid prepolymer (A-1) was obtained.

<Step B> Preparation of polyimide prepolymer 224.2 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 92.7 g of p-phenylenediamine and 49.78 g of the compound represented by the above formula (16) Was dissolved in 2000 g of N-methyl-2-pyrrolidone, and this solution was reacted at 60 ° C. for 6 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product (polyamic acid prepolymer). 30.0 g of the obtained polyamic acid prepolymer was dissolved in 200 g of N-methyl-2-pyrrolidone, and 17 g of pyridine and 11 g of acetic anhydride were added thereto, followed by dehydration and ring closure at 110 ° C. for 4 hours.
Then, the reaction product is precipitated, separated, washed and dried to obtain a polyimide prepolymer (B) having an acid viscosity of 0.5 dl / g and an imidization ratio of 80% and having an acid anhydride group at a molecular terminal (B). -4) 28.3 g were obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 80 g and 20 g of the polyimide prepolymer (B-4) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 5 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 18 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (4) was 1.60 dl / g.

Synthesis Example 5 <Step A> Preparation of Polyamic Acid Prepolymer In the same manner as in Step A of Synthesis Example 1, a polyamic acid prepolymer (A-1) was obtained. <Step B> Preparation of polyimide prepolymer In the same manner as in Step B of Synthesis Example 1, a polyimide prepolymer (B-1) was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 60 g and 40 g of the polyimide prepolymer (B-1) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 8 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 23 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (5) was 1.70 dl / g.

Synthesis Example 6 <Step A> Preparation of Polyamic Acid Prepolymer In the same manner as in Step A of Synthesis Example 1, a polyamic acid prepolymer (A-1) was obtained. <Step B> Preparation of polyimide prepolymer In the same manner as in Step B of Synthesis Example 1, a polyimide prepolymer (B-1) was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 30 g and 70 g of the polyimide prepolymer (B-1) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 6 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 22 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (6) was 1.60 dl / g.

Synthesis Example 7 <Step A> Preparation of Polyamic Acid Prepolymer 51.88 g of pyromellitic dianhydride and 48.12 g of 4,4′-diaminodiphenylmethane were added to N-methyl-2.
-Dissolved in 600 g of pyrrolidone, and reacted this solution at 20 ° C for 6 hours. Then, the obtained reaction solution is poured into a large excess of acetone to precipitate the reaction product, and the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln) of 1.4 dl / g. 95 g of a polyamic acid prepolymer (A-2) having an amino group at a molecular terminal was obtained.

<Step B> Preparation of Polyimide Prepolymer A polyimide prepolymer (B-1) was obtained in the same manner as in Step B of Synthesis Example 1. <Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
2) 80 g and 20 g of the polyimide prepolymer (B-1) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 5 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 18 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (7) was 1.55 dl / g.

Synthesis Example 8 <Step A> Preparation of Polyamic Acid Prepolymer In the same manner as in Step A of Synthesis Example 1, a polyamic acid prepolymer (A-1) was obtained. <Step B-1> Preparation of First Polyimide Prepolymer A polyimide prepolymer (B-1) was obtained in the same manner as in Step B of Synthesis Example 1. <Step B-2> Preparation of second polyimide prepolymer A polyimide prepolymer (B-4) was obtained in the same manner as in Step B of Synthesis Example 4.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
1) 80 g, 15 g of the polyimide prepolymer (B-1) obtained in the step B-1, and 5 g of the polyimide prepolymer (B-4) obtained in the step B-2 are dissolved in γ-butyrolactone. A solution having a solid concentration of 4% by weight was obtained. The viscosity of the solution was 16 mPa · s. At 40 ° C
For 24 hours to obtain a ternary block copolymer solution. The viscosity of the solution after the reaction was 19 mPa · s, and the logarithmic viscosity (ηl) of the obtained block copolymer (8) was
n) was 1.70 dl / g.

Synthesis Example 9 <Step A-1> Preparation of First Polyamic Acid Prepolymer A polyamic acid prepolymer (A-1) was obtained in the same manner as in Step A of Synthesis Example 1. <Step A-2> Preparation of second polyamic acid prepolymer 224.17 g of 2,3,5-tricarboxycyclopentylacetic dianhydride 422.5 g of bis [4- (4-aminophenoxy) phenyl] sulfone was converted to γ- The solution was dissolved in 6000 g of butyrolactone, and the solution was reacted at 60 ° C. for 6 hours. Then, the obtained reaction solution is poured into a large excess of acetone to precipitate the reaction product, and the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln).
650 g of a 1.5 dl / g polyamic acid prepolymer (A-3) having an amino group at the molecular terminal was obtained.

<Step B> Preparation of Polyimide Prepolymer A polyimide prepolymer (B-1) was obtained in the same manner as in Step B of Synthesis Example 1. <Step C> Production of Block Copolymer The polyamic acid prepolymer (A
-1) Dissolve 60 g, 20 g of the polyamic acid prepolymer (A-3) obtained in the step A-2, and 20 g of the polyimide prepolymer (B-1) obtained in the step B in γ-butyrolactone. A solution having a solid concentration of 4% by weight was obtained. The viscosity of the solution was 18 mPa · s. this,
The reaction was carried out at 40 ° C. for 24 hours to obtain a ternary block copolymer solution. The viscosity of the solution after the reaction is 20 mPa · s
The logarithmic viscosity number (ηln) of the obtained block copolymer (9) was 1.63 dl / g.

Synthesis Example 10 <Step A> Preparation of Polyamic Acid Prepolymer 26.37 g of pyromellitic dianhydride, 23.71 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 4,4′- 49.92 g of diaminodiphenyl ether was dissolved in 900 g of N-methyl-2-pyrrolidone, and this solution was reacted at 20 ° C. for 6 hours. Next, the obtained reaction solution is poured into a large excess of acetone to precipitate the reaction product, and the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηln) of 1.6 dl / g. Polyamic acid prepolymer having an amino group at the molecular terminal (A-
4) 96.3 g were obtained.

<Step B> Preparation of Polyimide Prepolymer 1,3,3a, 4,5,9b-Hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione 5
2.778 g, 2,3,5-tricarboxycyclopentylacetic acid dianhydride 6.64 g, p-phenylenediamine 1
2.44 g, 23.13 g of 4,4 ′-(p-phenylenediisopropylidene) dianiline and 5.01 g of the compound represented by the above formula (16) are dissolved in 800 g of N-methyl-2-pyrrolidone, and this solution is dissolved. Was reacted at 20 ° C. for 26 hours. Next, the obtained reaction solution is poured into a large excess of acetone to obtain a reaction product (polyamic acid prepolymer).
Was precipitated. Obtained polyamic acid prepolymer 1
0.0 g was dissolved in 900 g of γ-butyrolactone,
62 g of pyridine and 141 g of acetic anhydride are added to give 60 g.
Dehydration ring closure was performed at 2 ° C for 2 hours. Next, the reaction product is precipitated, separated, washed and dried to obtain a logarithmic viscosity (ηl).
n) 0.73 dl / g, imidization rate 90%, polyimide prepolymer having an acid anhydride group at a molecular terminal (B-
5) 97.2 g were obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
4) 75 g and 25 g of the polyimide prepolymer (B-5) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 2
It was 0 mPa · s. This was reacted at 30 ° C. for 48 hours to obtain a solution of a block copolymer. The viscosity of the solution after the reaction was 27 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (10) was 1.8 dl / g.

Synthesis Example 11 <Step A> Preparation of polyamic acid prepolymer 40.72 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 51.28 g of 4,4′-diaminodiphenyl ether were added to N-methyl- 900 g of 2-pyrrolidone
And the solution was reacted at 20 ° C. for 6 hours. Next, the obtained reaction solution is poured into a large excess of acetone to precipitate the reaction product, and the reaction product is precipitated, separated, washed,
By drying, logarithmic viscosity (ηln) 1.6 dl
/ G of 93 g of a polyamic acid prepolymer (A-5) having an amino group at the molecular terminal.

<Step B> Preparation of Polyimide Prepolymer 1,3,3a, 4,5,9b-Hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione 5
9.19 g, 4.69 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, p-phenylenediamine 13.
44 g, 2,2-bis (4-aminophenyl) -1,1,1,
10.39 g of 1,3,3,3-hexafluoropropane,
9.04 g of 4,4′-diaminodiphenylmethane and 3.25 g of the compound represented by the above formula (16) are dissolved in 300 g of N-methyl-2-pyrrolidone.
Reaction was performed at 26 ° C. for 26 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product (polyamic acid prepolymer). 100.0 g of the obtained polyamic acid prepolymer was mixed with γ-butyrolactone 900
g of pyridine, 65.2 g of pyridine and 84.2 g of acetic anhydride.
2 g was added and dehydration ring closure was performed at 60 ° C. for 2 hours. Next, the reaction product is precipitated, separated, washed and dried to obtain a polyimide prepolymer (B) having an acid viscosity of 0.58 dl / g and an imidization ratio of 95% and having an acid anhydride group at a molecular terminal (B). -6) 94 g was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
5) 75 g and 25 g of the polyimide prepolymer (B-6) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 4 mPa · s. This was reacted at 50 ° C. for 4 hours to obtain a solution of a block copolymer. The viscosity of the solution after the reaction was 21 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (11) was 1.6 dl / g.

Comparative Synthesis Example 1 1,3,3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3 -34.7 g of dione, p-
10.41 g of phenylenediamine, 3.84 g of 1-hexadecanoxy-2,4-diaminobenzene and 1.05 g of 3-aminopropylmethyldiethoxysilane were dissolved in 200 g of N-methyl-2-pyrrolidone, and the solution was dissolved at 20 ° C. The reaction was performed for 24 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product. 50.0 g of the obtained polymer was γ-butyrolactone 4
50 g, pyridine 5.0 g and acetic anhydride 1
0.8 g was added thereto, followed by dehydration ring closure at 50 ° C. for 3 hours. Then, the reaction product was precipitated, separated, washed and dried to obtain 47 g of a soluble polyimide polymer (b) having an logarithmic viscosity (ηln) of 0.72 dl / g and an imidation ratio of 90%.

Comparative Synthesis Example 2 <Step A> Preparation of Polyamic Acid Prepolymer A polyamic acid prepolymer (A-3) was obtained in the same manner as in Step A-2 of Synthesis Example 10. <Step B> Preparation of polyimide prepolymer In the same manner as in Step B of Synthesis Example 1, a polyimide prepolymer (B-1) was obtained.

<Step C> Production of Block Copolymer The polyamic acid prepolymer (A-
3) 80 g and 20 g of the polyimide prepolymer (B-1) obtained in the step B were dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight. The viscosity of the solution is 1
It was 5 mPa · s. This was reacted at 40 ° C. for 24 hours to obtain a block copolymer solution. The viscosity of the solution after the reaction was 18 mPa · s, and the logarithmic viscosity (ηln) of the obtained block copolymer (i) was 1.50 dl / g.

Example 1 The block copolymer (1) obtained in Synthesis Example 1 was dissolved in γ-butyrolactone to form a solution having a solid concentration of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm to obtain a liquid crystal. An alignment agent was prepared. When butyl cellosolve was added until precipitation occurred in 50 g of the liquid crystal aligning agent, the amount of butyl cellosolve that could be added was 20 g, and the resulting block copolymer was excellent in solubility.

Further, the obtained liquid crystal aligning agent was used at a solid concentration of 2
When diluted with an ink jet printer, the difference between the maximum film thickness and the minimum film thickness (film thickness uniformity) was 70%.
Angstrom and good. Next, when the continuous ink jet printability was tested, no coating failure was observed, and the difference in film thickness uniformity between the start and end of printing (continuous printability) was very stable at 30 Å.

A liquid crystal aligning agent was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a printing machine for coating a liquid crystal alignment film, dried on a hot plate at 180 ° C. for 10 minutes, and dried. A coating having a thickness of 600 Å was formed. A rubbing machine having a roll in which a rayon cloth was wound around the coating film was subjected to a rubbing treatment at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair foot pushing length of 0.4 mm. After immersing the substrate coated with the alignment film in isopropyl alcohol for 1 minute, both substrates were dried on a hot plate at 100 ° C. for 5 minutes.

Next, the outer edge of each of the pair of alignment-treated liquid crystal holding substrates having the liquid crystal alignment film has a diameter of 5.5 μm.
m, an epoxy resin adhesive containing aluminum oxide spheres is screen-printed and applied, and a pair of liquid crystal sandwiching substrates are overlapped with each other so that the liquid crystal alignment film surfaces face each other, and the rubbing direction is orthogonal, and then pressure-bonded. Cured. Next, a nematic type liquid crystal (MLC-5081 manufactured by Merck) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photocuring adhesive. The polarizing plates were adhered so that the polarizing direction of the polarizing plates coincided with the rubbing direction of the liquid crystal alignment films of the respective substrates, thereby producing a liquid crystal display device.

When the orientation of the liquid crystal, the pretilt angle, the voltage holding ratio and the elimination of an afterimage were evaluated for the obtained liquid crystal display device, the orientation of the liquid crystal was good and the afterimage erasing time was a small value of 1 minute. Thus, the characteristics required for a liquid crystal alignment film were satisfied. Tables 1 and 2 show these results.

Examples 2 to 12 and Comparative Examples 1 to 4 According to the formulations shown in Table 1, the polymers obtained in Synthesis Examples 2 to 11 and Comparative Synthesis Examples 1 to 2 and the liquid crystal aligning agents using additives were adjusted. Then, an alignment treatment was performed in the same manner as in Example 1 except that the liquid crystal was changed to MLC-2012 in Example 4, and a liquid crystal display element was manufactured in the same manner as in Example 1. Each of the obtained liquid crystal display elements was evaluated for the orientation of the liquid crystal, the afterimage erasing time, and the like. The results are shown in Tables 1 and 2.

[0107]

[Table 1]

[0108]

[Table 2]

[0109]

The following effects are recognized from Examples 1 to 12 and Comparative Examples 1 to 4. That is, a liquid crystal aligning agent that uses polyamic acid or polyimide alone or is simply mixed has problems such as poor coating, poor print quality, and performance as a liquid crystal display element during inkjet printing. According to the combination, both the ink-jet printability and various characteristics as a liquid crystal display element can be satisfied at a high level. Thus, according to the present invention,
TN-type and STN-type liquid crystal displays are compatible with inkjet printing, which is promising for liquid crystal panel yield improvement and cost reduction, and can satisfy the pretilt angle, voltage holding ratio, and afterimage characteristics required for liquid crystal display elements at a high level. By selecting a liquid crystal to be used in addition to being able to be suitably used for the element, SH (Super Homeotrop) can be obtained.
ic) type, IPS (In-Plane Switchin)
g) It can be suitably used for a type, ferroelectric and antiferroelectric liquid crystal display device and the like. In particular, the block copolymer (11) used in Example 12 is suitable for a reflective LCD or a projector because it has excellent transparency. Further, the liquid crystal display device having the liquid crystal alignment film prepared by the method of the present invention can be effectively used for various devices, for example, display devices such as a desk calculator, a wristwatch, a clock, a coefficient display plate, a word processor, a personal computer, and a liquid crystal television. Used for

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Claims (2)

[Claims] 1. A block copolymer comprising a first polyimide block and a second polyamic acid block in a molecule, wherein the first polyimide block comprises:
The following formula (1) Here, R ¹ represents a hydrogen atom or an alkyl group, R ² represents a divalent organic group, 1 represents an integer of 1 to 4, and n represents
Represents the number of repeating units and is a positive number, and a repeating unit represented by the following formula (2): Here, R ³ is a divalent organic group, and m represents the number of repeating units and is a positive number, containing at least one type of repeating unit selected from the group consisting of: And the second polyamic acid block is represented by the following formula (3): Here, R ⁶ represents a hydrogen atom or an alkyl group, R ⁷ represents a divalent organic group, and q represents the number of repeating units and is a positive number, and the following formula (4) ) Here, R ⁴ represents a hydrogen atom or an alkyl group, R ⁵ represents a divalent organic group, and p represents a repeating unit and is a positive number, and is selected from the group consisting of: A liquid crystal aligning agent comprising a block copolymer containing at least one type of repeating unit. 2. A liquid crystal display device comprising a liquid crystal alignment film obtained by using the liquid crystal alignment agent according to claim 1.