TWI710585B - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element. The liquid crystal alignment agent includes a polymer (A) and a solvent (B). The polymer (A) is synthesized by a tetracarboxylic dianhydride compound (a) and a diamine compound (b). The aforementioned liquid crystal alignment agent has a specific viscosity, so as to fabricate the liquid crystal alignment film with high Young's Modulus and the liquid crystal display element including the liquid crystal alignment film. There are no defects of Particle-Galaxy in the liquid crystal display element.

Description

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element, and particularly provides a liquid crystal alignment agent with a specific viscosity, and a liquid crystal alignment film with high Young's modulus formed thereon, and the liquid crystal alignment film The liquid crystal display element.

In recent years, the development of new liquid crystal display elements has been vigorously developed. For example, the industry has developed a liquid crystal display element that drives the liquid crystal by arranging two electrodes on a single-sided substrate in a comb-tooth manner to generate a parallel electric field on the surface of the substrate. , To control the liquid crystal molecules. The above-mentioned liquid crystal display element is generally called a lateral electric field effect type (IPS type), and it is known that it has excellent wide viewing angle characteristics. However, the aforementioned IPS type liquid crystal display element still has the problem of image retention due to excessively high ion density.

Japanese Patent Laid-Open No. 2009-175684 discloses a low ion density liquid crystal alignment film and a piperazine structure-containing diamine compound for preparing the liquid crystal alignment film. By using a diamine compound containing a piperazine structure, the resulting alignment film can improve the problem of excessive ion density.

However, the Young's Modulus of the liquid crystal alignment film prepared by the above liquid crystal alignment agent is too low. When it is applied to a liquid crystal display device, the liquid crystal display device prepared is prone to defects caused by a large number of broken bright spots. Reduce its display quality.

It can be seen from the above that in order to meet the requirements of the current IPS type liquid crystal display industry, how to improve the Young's modulus of the liquid crystal alignment film to eliminate the liquid crystal display element with broken bright spots is the goal of the technical field.

Therefore, one aspect of the present invention is to provide a liquid crystal alignment agent. The liquid crystal alignment agent includes a polymer (A) and a solvent (B).

Another aspect of the present invention is to provide a liquid crystal alignment film comprising the above-mentioned liquid crystal alignment agent.

Another aspect of the present invention is to provide a liquid crystal display element having the above-mentioned liquid crystal alignment film, and the liquid crystal display element has no defects caused by broken bright spots.

According to the above aspect of the present invention, a liquid crystal alignment agent is proposed. The liquid crystal alignment agent includes polymer (A) and solvent (B), which will be analyzed below.

Polymer (A)

The polymer (A) of the present invention is obtained by reacting a tetracarboxylic dianhydride compound (a) with a diamine compound (b).

Preferable specific examples of the above-mentioned polymer (A) are polyimide polymers, polyimide polymers, polyimine-based block copolymers, or a combination of these. Among them, preferred specific examples of polyimide block copolymers are polyimide block copolymers, polyimide block copolymers, polyimide-polyimide block copolymers, and polyimide block copolymers. Polymer, or a combination of them.

Tetracarboxylic dianhydride compound (a)

The tetracarboxylic dianhydride compound (a) of the present invention may include the tetracarboxylic dianhydride compound (a-1) represented by the following formula (I). Second, the tetracarboxylic dianhydride compound (a) may optionally contain other tetracarboxylic dianhydride compounds (a-2).

Tetracarboxylic dianhydride compound (a-1)

The tetracarboxylic dianhydride compound (a-1) has a structure as shown in formula (I):

In the formula (I), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen atoms, substituted or unsubstituted alkyl groups, and substituted or unsubstituted alkyl groups. At least one of a group consisting of an oxy group and a substituted or unsubstituted aromatic group; Z each independently represents -CONH-, -NHCO-, -NHCO ₂ -, -OCONH- or -NHCONH-; h, i, j and k each independently represent an integer from 0 to 4; m and n each independently represent an integer from 0 to 3.

The aforementioned halogen atom may be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Preferably, the halogen atom may be a fluorine atom, a chlorine atom or a bromine atom. The substituted or unsubstituted alkyl group may be an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl or trifluoromethyl. Preferably, the substituted or unsubstituted alkyl group may be methyl, trifluoromethyl or isopropyl. The substituted or unsubstituted alkoxy group may be an alkoxy group having 1 to 8 carbon atoms such as methoxy, ethoxy or phenoxy. Preferably, the substituted or unsubstituted alkoxy group may be a methoxy group or a phenoxy group. The substituted or unsubstituted aromatic group may be a monocyclic or condensed polycyclic aromatic having a carbon number of 6 to 14 such as phenyl, naphthyl or p-methoxyphenyl. Preferably, the substituted or unsubstituted aromatic group may be a phenyl group. Preferably, the Z can be -CONH- or -NHCO-.

The foregoing m and n preferably each independently represent an integer from 0 to 2, and the foregoing h, i, j, and k preferably each independently represent an integer from 0 to 2.

In an embodiment, the tetracarboxylic dianhydride compound (a-1) may include the tetracarboxylic dianhydride compound represented by the following formula (I-1) to formula (I-8).

The aforementioned tetracarboxylic dianhydride compound (a-1) may be used singly or in combination of plural kinds.

Based on the total usage amount of the tetracarboxylic dianhydride compound (a) is 100 mol, the usage amount of the tetracarboxylic dianhydride compound (a-1) is 5 mol to 60 mol, preferably 10 mol to 55 Mol, and more preferably 15 mol to 50 mol.

If the tetracarboxylic dianhydride compound (a) of the liquid crystal alignment agent does not contain the tetracarboxylic dianhydride compound (a-1), the Young's modulus of the resulting liquid crystal alignment film is too low, and the performance of the liquid crystal display element cannot be improved. It is difficult to improve the display quality due to broken bright spots.

Wherein, when Z in the tetracarboxylic dianhydride compound (a-1) represented by formula (I) represents -CONH- or -NHCO-, the resulting liquid crystal alignment film has a higher Young's modulus, It can further improve the defect of broken bright spots of liquid crystal display elements.

Other tetracarboxylic dianhydride compounds (a-2)

In addition to the aforementioned tetracarboxylic dianhydride compound (a-1), the tetracarboxylic dianhydride compound (a) of the present invention may optionally contain other tetracarboxylic dianhydride compounds ( a-2).

Preferred specific examples of other tetracarboxylic dianhydride compounds (a-2) are (1) aliphatic tetracarboxylic dianhydride compound, (2) alicyclic tetracarboxylic dianhydride compound, (3) aromatic tetracarboxylic acid An acid dianhydride compound or (4) a tetracarboxylic dianhydride compound having the structure shown in formula (IV-1) to (IV-6), etc.

The (1) aliphatic tetracarboxylic dianhydride compound of the present invention may include, but is not limited to, aliphatic tetracarboxylic dianhydride compounds such as ethane tetracarboxylic dianhydride or butane tetracarboxylic dianhydride.

The (2) alicyclic tetracarboxylic dianhydride compound of the present invention can include but is not limited to 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2-dimethyl-1,2,3 ,4-Cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dichloro-1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopenta Alkyltetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-di Butylcycloheptyl-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride or bicyclo[2.2.2]- Alicyclic tetracarboxylic dianhydride compounds such as oct-7-ene-2,3,5,6-tetracarboxylic dianhydride.

Specific examples of the (3) aromatic tetracarboxylic dianhydride compound of the present invention may include, but are not limited to, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic dianhydride, benzene Tetracarboxylic dianhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3' ,4,4'-Biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3'- 4,4'-Diphenylethane tetracarboxylic dianhydride, 3,3',4,4'-Dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetra Phenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4, 4'-diphenyl ether tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 2,3,3',4'-diphenyl sulfide Tetracarboxylic dianhydride, 3,3',4,4'-diphenyl sulfide tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy) diphenyl dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic dianhydride, 2,2' ,3,3'-Diphenyltetracarboxylic dianhydride, 2,3,3',4'-Diphenyltetracarboxylic dianhydride, 3,3',4,4'-Diphenyltetracarboxylic acid Dianhydride, bis(phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) bis Anhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol- Bis (anhydro trimellitate), propylene glycol-bis (anhydro trimellitate), 1,4-butanediol-bis (anhydro trimellitate), 1,6-hexanediol-bis ( Dehydrated trimellitate), 1,8-octanediol-bis(dehydrated trimellitate), 2,2-bis(4-hydroxyphenyl)propane-bis(dehydrated trimellitate), 2,3,4,5-Tetrahydrofurantetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-diside oxy-3-furanyl) -Naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5- (Di-side oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl- 5-(Tetrahydro-2,5-diside oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5, 9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-c] -Furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxy-3-furanyl) -Naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5- Di-side oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-di Methyl-5-(tetrahydro-2,5-diside oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 5-(2,5- Di-side oxytetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride and the like.

The (4) tetracarboxylic dianhydride compounds having the structures shown in formulas (IV-1) to (IV-6) of the present invention are as follows, respectively.

In formula (IV-5), X ₁ represents a divalent group having an aromatic ring, X ₂ and X ₃ may be the same or different, and X ₂ and X ₃ may each independently represent a hydrogen atom or an alkyl group, and r represents an integer from 1 to 2. The tetracarboxylic dianhydride compound having the structure shown in formula (IV-5) is preferably a compound having the structure shown in the following formulas (IV-5-1) to (IV-5-3).

In formula (IV-6), X ₄ represents a divalent group having an aromatic ring, X ₅ and X ₆ may be the same or different, and X ₅ and X ₆ may each independently represent a hydrogen atom or an alkyl group. The tetracarboxylic dianhydride compound having the structure shown in formula (IV-6) is preferably a compound having the structure shown in the following formula (IV-6-1).

Preferably, the tetracarboxylic dianhydride compound (a-2) may include, but is not limited to, 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride (1,2,3,4-cyclobutane tetracarboxylic acid dianhydride) ), 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tri carboxycyclopentylacetic acid dianhydride (2,3,5-tri carboxycyclopentylacetic acid dianhydride), 1,2, 4,5-Cyclohexanetetracarboxylic dianhydride, 3,4-Dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic dianhydride, pyromellitic dianhydride , 3,3',4,4'-benzophenone tetracarboxylic dianhydride or 3,3',4,4'-biphenyl tetracarboxylic dianhydride, etc. The aforementioned tetracarboxylic dianhydride compound (a-2) may be used singly or in combination of plural kinds.

Based on the total usage amount of the diamine compound (b) being 100 mol, the usage amount of the tetracarboxylic dianhydride compound (a) is 20 mol to 200 mol, and preferably 30 mol to 120 mol.

Diamine compound (b)

The diamine compound (b) of the present invention includes a diamine compound (b-1) represented by the following formula (II) and/or a diamine compound (b-2) represented by the following formula (III). Second, the diamine compound (b) may optionally contain other diamine compounds (b-3).

Diamine compound (b-1)

The diamine compound (b-1) has a structure represented by the following formula (II):

In the formula (II), W ₁ represents a cycloalkylene group with a carbon number of 4 to 6 substituted by a tertiary nitrogen atom, and W ₂ represents an alkylene group with a carbon number of 1 to 5.

Among them, the tertiary nitrogen atom refers to the three bonds of nitrogen atoms that are bonded to atoms other than hydrogen atoms. Preferably, the tertiary nitrogen atom represents a nitrogen atom bonded to a carbon atom.

或

，且W₂代表碳數為1至5之伸烷基。 Preferably, in formula (II), the W ₁ represents

or

, And W ₂ represents an alkylene group having a carbon number of 1 to 5.

In a specific example, the diamine compound (b-1) represented by the formula (II) has a diamine compound having the structure represented by the following formula (II-1) to formula (II-5):

The aforementioned diamine compound (b-1) may be used singly or in combination of plural kinds.

Based on the total usage amount of the diamine compound (b) is 100 mol, the usage amount of the diamine compound (b-1) is 3 mol to 45 mol, preferably 6 mol to 40 mol, and more preferably It is 9 mol to 35 mol.

If the diamine compound (b) of the liquid crystal alignment agent contains the diamine compound (b-1) represented by formula (II), the resulting liquid crystal alignment film has a higher Young's modulus, which can further improve the liquid crystal Broken bright spots of display components.

Diamine compound (b-2)

The diamine compound (b-2) has a structure represented by the following formula (III):

In formula (III), the y represents an integer of 1-12.

In one embodiment, the diamine compound (b-2) having the structure shown in formula (III) may include the diamine compound having the structure shown in the following formula (III-1) to formula (III-3) :

In formula (III-1) to formula (III-3), y may represent an integer of 1-12.

Specific examples of the aforementioned diamine compound having the structure shown in formula (III-1) can be bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane , 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane , 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane Alkane, 1,9-bis(4-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, or any mixture of the above compounds.

Specific examples of the aforementioned diamine compound having the structure shown in formula (III-2) can be bis(2-aminophenoxy)methane, 1,2-bis(2-aminophenoxy)ethane , 1,3-bis(2-aminophenoxy)propane, 1,4-bis(2-aminophenoxy)butane, 1,5-bis(2-aminophenoxy)pentane , 1,6-bis(2-aminophenoxy)hexane, 1,7-bis(2-aminophenoxy)heptane, 1,8-bis(2-aminophenoxy)octane Alkane, 1,9-bis(2-aminophenoxy)nonane, 1,10-bis(2-aminophenoxy)decane, or any mixture of the above compounds.

Specific examples of the aforementioned diamine compound having the structure shown in formula (III-3) can be bis(3-aminophenoxy)methane, 1,2-bis(3-aminophenoxy)ethane , 1,3-bis(3-aminophenoxy)propane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(3-aminophenoxy)pentane , 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(3-aminophenoxy)octane Alkane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(3-aminophenoxy)decane, or any mixture of the above compounds.

Preferably, specific examples of the diamine compound (b-2) having the structure shown in formula (III) may be 1,3-bis(4-aminophenoxy)propane, 1,4-bis( 4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis (4-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,3-bis(2-aminophenoxy)propane, 1,4-bis (2-aminophenoxy)butane, 1,5-bis(2-aminophenoxy)pentane, 1,6-bis(2-aminophenoxy)hexane, 1,7- Bis(2-aminophenoxy)heptane, 1,8-bis(2-aminophenoxy)octane, 1,3-bis(3-aminophenoxy)propane, 1,4- Bis(3-aminophenoxy)butane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(3-aminophenoxy)hexane, 1,7 -Di(3-aminophenoxy)heptane or 1,8-bis(3-aminophenoxy)octane, etc. The aforementioned diamine compound (b-2) can be used singly or as a mixture of multiple types.

Based on the total usage amount of the diamine compound (b) being 100 mol, the usage amount of the diamine compound (b-2) is 10 mol to 95 mol, preferably 15 mol to 90 mol, and more preferably From 20 mol to 85 mol.

If the diamine compound (b) of the liquid crystal alignment agent contains the diamine compound (b-2) represented by the formula (III), the resulting liquid crystal alignment film has a higher Young's modulus, which can further improve the liquid crystal Broken bright spots of display components.

If the diamine compound (b) of the liquid crystal alignment agent contains both the diamine compound (b-1) represented by formula (II) and the diamine compound (b-2) represented by formula (III), the prepared The obtained liquid crystal alignment film can have a higher Young's modulus, and can further improve the broken bright spot defects of the liquid crystal display element.

Other diamine compounds (b-3)

In addition to the aforementioned diamine compound (b-1) and/or diamine compound (b-2), the diamine compound (b) of the present invention may optionally contain other diamines within the range that does not affect the efficacy Compound (b-3).

Other diamine compounds (b-3) may include, but are not limited to, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminobutane Pentane, 1,6-Diaminohexane, 1,7-Diaminoheptane, 1,8-Diaminooctane, 1,9-Diaminononane, 1,10-Diamino Decane, 4,4'-diaminoheptane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1 ,7-diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylnonane, 2,11-diaminododecane, 1,12-diaminooctadecane, 1,2-bis(3-aminopropoxy ) Ethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylamine, 1,3-diaminocyclohexane, 1,4-Diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene diamine, tricyclic (6.2.1.0 ^2,7 )-undecene dimethyl Diamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'- Diaminodiphenyl sulfide, 4,4'-diaminobenzaniline, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,5 -Diaminonaphthalene, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydroindene, 6-amino-1-(4'-aminophenyl) )-1,3,3-trimethylindenyl, hexahydro-4,7-methane-bridged indenyldimethylene diamine, 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)hexafluoropropane, 2,2-bis[4-(4-aminobenzene) (Oxy) phenyl) chrysene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-amino) Phenoxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroanthracene, 9,10-bis(4-aminophenyl)anthracene [9,10-bis(4-aminophenyl) anthracene], 2,7-diaminopyridine, 9,9-bis(4-aminophenyl)pyridine, 4,4'-methylene-bis(2-chloroaniline), 4,4'-( P-phenylene isopropylidene) bisaniline, 4,4'-(m-phenylene isopropylidene) bisaniline, 2,2'-bis[4-(4-amino-2-tri Fluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 5-[4-( 4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene {5-[4-(4-n-pentylcycloh exyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene}, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane{1, 1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethyl phenyl)cyclohexane} or other diamine compounds represented by the following formulas (V-1) to (V-29).

、

、

、

或

，且Y₂代表含甾基團、三氟甲基、氟基、碳數為2至30之烷基或衍生自吡啶、嘧啶、三嗪、哌啶及哌嗪等含氮原子環狀結構的一價基團。 In formula (V-1), Y ₁ represents -o-,

,

,

,

or

, And Y ₂ represents a steroid-containing group, a trifluoromethyl group, a fluoro group, an alkyl group with a carbon number of 2 to 30 or those derived from pyridine, pyrimidine, triazine, piperidine and piperazine and other nitrogen-containing ring structures Monovalent group.

The other diamine compound represented by the above formula (V-1) may preferably be 2,4-diaminophenyl ethyl formate (2,4-diaminophenyl ethyl formate), 3,5-diaminophenyl ethyl formate Ethyl (3,5-diaminophenyl ethyl formate), 2,4-diaminophenyl propyl formate (2,4-diaminophenyl propyl formate), 3,5-diaminophenyl propyl formate (3,5 -diaminophenyl propyl formate), 1-dodecoxy-2,4-diamino-benzene (1-dodecoxy-2,4-diamino-benzene), 1-hexadecoxy-2,4-diamine Benzene (1-hexadecoxy-2,4-diaminobenzene), 1-octadecoxy-2,4-diaminobenzene (1-octadecoxy-2,4-diaminobenzene) or the following formula (V-1-1 ) To other diamine compounds represented by formula (V-1-6).

、

、

、

或

，Y₄及Y₅表示伸脂肪族環、伸芳香族環或伸雜環基團，且Y₆代表碳數為3至18之烷基、碳數為3至18之烷氧基、碳數為1至5之氟烷基、碳數為1至5之氟烷氧基、氰基或鹵素原子。 In formula (V-2), Y ₃ represents -o-,

,

,

,

or

, Y ₄ and Y ₅ represent an aliphatic ring, an aromatic ring or a heterocyclic ring group, and Y ₆ represents an alkyl group with a carbon number of 3 to 18, an alkoxy group with a carbon number of 3 to 18, and a carbon number It is a fluoroalkyl group of 1 to 5, a fluoroalkoxy group of 1 to 5 carbon atoms, a cyano group or a halogen atom.

The other diamine compound represented by the above formula (V-2) may preferably be the diamine compound represented by the following formula (V-2-1) to formula (V-2-13):

In formulas (V-2-10) to (V-2-13), s may represent an integer from 3 to 12.

In formula (V-3), Y ₇ represents a hydrogen atom, an acyl group having 1 to 5 carbons, an alkyl group having 1 to 5 carbons, an alkoxy group having 1 to 5 carbons, or halogen. Y ₈ is an integer from 1 to 3. When Y _{8 is} greater than 1, a plurality of Y ₇ may be the same or different.

The diamine compound represented by the above formula (V-3) is preferably selected from (1) Y ₈ is 1: p-diaminobenzene, m-diaminobenzene, o-diaminobenzene or 2,5-diaminobenzene Aminotoluene, etc.; (2) Y ₈ is 2:4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl -4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino Biphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-Dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl or 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, etc.; (3) Y ₈ is 3: 1,4-bis(4'-aminophenyl)benzene, etc., more preferably selected from p-diaminobenzene, 2,5-diaminotoluene, 4,4'- Diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl or 1,4-bis(4'-aminophenyl)benzene.

In the formula (V-4), Y ₉ represents an integer of 1 to 5. The formula (V-4) is preferably selected from 4,4'-diaminodiphenyl sulfide.

In formula (V-5), Y ₁₀ and Y ₁₂ can be the same or different, and represent a divalent organic group, respectively, and Y ₁₁ represents a nitrogen-containing atom derived from pyridine, pyrimidine, triazine, piperidine, and piperazine A divalent group in a cyclic structure.

The diamine compound represented by the formula (V-5) may preferably be a diamine compound represented by the following formula (V-5-1):

In formula (V-6), Y ₁₃ , Y ₁₄ , Y ₁₅ and Y ₁₆ may be the same or different, respectively, and may represent a hydrocarbon group having 1 to 12 carbon atoms. Y ₁₇ represents an integer from 1 to 3, and Y ₁₈ represents an integer from 1 to 20.

In the formula (V-7), Y ₁₉ represents -o- or cyclohexylene, Y ₂₀ represents -CH ₂ -, Y ₂₁ represents phenylene or cyclohexylene, and Y ₂₂ represents a hydrogen atom or Heptyl.

The diamine compound represented by the above formula (V-7) is preferably selected from the diamine compounds represented by the following formula (V-7-1) and formula (V-7-2).

Other diamine compounds (b-3) represented by formula (V-8) to formula (V-29) are as follows:

In formulas (V-16) to (V-19), Y ₂₃ is preferably an alkyl group having 1 to 10 carbons or an alkoxy group having 1 to 10 carbons. In formulas (V-20) to (V-24), Y _{24 is} preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

Other diamine compounds (b-3) may preferably include but are not limited to 1,2-diaminoethane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenyl Methane, 4,4'-diaminodiphenyl ether, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene, 1, 1-Bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane, ethyl 2,4-diaminophenylcarboxylate, p-diamine Benzene, m-diaminobenzene, o-diaminobenzene, formula (V-1-1), formula (V-1-2), formula (V-1-5), formula (V-2-1), A compound represented by formula (V-2-11), formula (V-7-1), formula (V-25), or formula (V-28).

The aforementioned other diamine compound (b-3) may be used alone or in combination of plural kinds.

Based on the total usage amount of the diamine compound (b) being 100 mol, the usage amount of other diamine compounds (b-3) is 0 mol to 97 mol, preferably 0 mol to 94 mol, and more Preferably, it is 0 mol to 91 mol.

Manufacturing method of polymer (A)

The preparation of the polyamide acid polymer according to the present invention can be a general method. Preferably, the preparation method of the polyamide acid polymer comprises the following steps: a tetracarboxylic dianhydride compound (a) and a diamine The mixture of compound (b) is dissolved in a solvent, and the polycondensation reaction is carried out at a temperature of 0°C to 100°C and reacted for 1 hour to 24 hours, and then the above reaction solution is subjected to reduced pressure distillation with an evaporator, namely Polyamide acid polymer can be obtained, or the above reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and then the precipitate is dried by a vacuum drying method to obtain polyamide acid polymerization Things.

The solvent used in the polycondensation reaction may be the same as or different from the solvent in the following liquid crystal alignment agent, and the solvent used in the polycondensation reaction is not particularly limited, as long as it can dissolve the reactants and products. Preferably, the solvent includes but is not limited to (1) aprotic polar solvent, for example: N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide , N,N-dimethylformamide, dimethyl sulfide, γ-butyrolactone, tetramethylurea or hexamethyltriamine phosphate and other aprotic polar solvents; (2) Phenolic solvents, For example: phenolic solvents such as m-cresol, xylenol, phenol or halogenated phenols. Based on 100 parts by weight of the mixture, the solvent used in the polycondensation reaction is preferably 200 parts by weight to 2000 parts by weight, and more preferably 300 parts by weight to 1800 parts by weight.

In particular, in the polycondensation reaction, the solvent can be used in combination with an appropriate amount of poor solvent, where the poor solvent will not cause the precipitation of the polyamide acid polymer. The poor solvent can be used alone or in a mixture of multiple, and it includes but is not limited to (1) alcohols, for example: methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanedi Alcohols such as alcohols or triethylene glycol; (2) Ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone; (3) Esters, such as: Esters such as methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate or ethylene glycol ethyl ether acetate; (4) ethers, such as diethyl ether, Ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether (5) Halogenated hydrocarbons, such as dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichloro Halogenated hydrocarbons such as benzene; (6) Hydrocarbons, such as hydrocarbons such as tetrahydrofuran, hexane, heptane, octane, benzene, toluene or xylene, or any combination of the above solvents. Based on the usage amount of the diamine compound (b) being 100 parts by weight, the usage amount of the poor solvent is preferably 0 parts by weight to 60 parts by weight, and more preferably 0 parts by weight to 50 parts by weight.

The preparation of the polyimide polymer of the present invention can be a general method. Preferably, the preparation method of the polyimide polymer first dissolves a mixture in a solution, wherein the mixture contains a tetracarboxylic dianhydride compound (a ) And the diamine compound (b), and carry out a polymerization reaction to form a polyamide acid polymer. Then, in the presence of a dehydrating agent and a catalyst, further heating and dehydration and ring-closing reaction are carried out, so that the amide functional group in the polyamide acid polymer is converted into an amide functional group (ie, amide Amination) to obtain polyimide polymer.

The solvent used in the dehydration ring-closing reaction can be the same as the solvent in the following liquid crystal alignment agent, so it will not be repeated. Based on the usage amount of the polyamide acid polymer being 100 parts by weight, the usage amount of the solvent used in the dehydration ring-closure reaction is preferably 200 parts by weight to 2000 parts by weight, and more preferably 300 parts by weight to 1800 parts by weight.

In order to obtain a better degree of imidization of the polyamide acid polymer, the operating temperature of the dehydration and ring-closure reaction is preferably 40°C to 200°C, and more preferably 40°C to 150°C. If the operating temperature of the dehydration ring-closing reaction is lower than 40°C, the imidization reaction is incomplete, and the degree of imidization of the polyamide acid polymer is reduced. However, if the operating temperature of the dehydration and ring-closure reaction is higher than 200°C, the weight average molecular weight of the obtained polyimide polymer is low.

The dehydrating agent used in the dehydration ring-closing reaction may be selected from acid anhydride compounds, specifically such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. Based on 1 mol of the polyamide acid polymer, the amount of the dehydrating agent used is 0.01 mol to 20 mol. The catalyst used in the dehydration ring-closure reaction can be selected from (1) pyridine compounds, such as pyridine, collidine or lutidine; (2) tertiary amine compounds, such as: Tertiary amine compounds such as triethylamine. Based on the usage amount of the dehydrating agent is 1 mol, the usage amount of the catalyst is 0.5 mol to 10 mol.

Preferred specific examples of the polyimide block copolymer of the present invention are polyimide block copolymer, polyimide block copolymer, polyimide-polyimide block Copolymer, or any combination of these.

The preparation of the polyimine-based block copolymer of the present invention can be a general method. Preferably, the preparation method of the polyimine-based block copolymer is first to dissolve a starting material in a solvent and proceed A polycondensation reaction, wherein the starting material includes the above-mentioned at least one polyamide acid polymer and/or the above-mentioned at least one polyimide polymer, and may further include a tetracarboxylic dianhydride compound (a) and Diamine compound (b).

The tetracarboxylic dianhydride compound (a) and diamine compound (b) in the starting material are the same as the tetracarboxylic dianhydride compound (a) and diamine compound used in the preparation of polyamide acid polymers. (b) It is the same, and the solvent used in the polycondensation reaction can be the same as the solvent in the following liquid crystal alignment agent, which will not be repeated here.

Based on 100 parts by weight of the starting material, the solvent used in the polycondensation reaction is preferably 200 parts by weight to 2000 parts by weight, and more preferably 300 parts by weight to 1800 parts by weight. The operating temperature of the polycondensation reaction is preferably 0°C to 200°C, and more preferably 0°C to 100°C.

Preferably, the starting material includes but not limited to (1) two kinds of polyimide polymers with different end groups and different structures; (2) two kinds of polyimide polymers with different end groups and different structures Polymers; (3) Polyamide polymers and polyimide polymers with different end groups and different structures; (4) Polyamide polymers, tetracarboxylic dianhydride compounds and diamine compounds, Wherein, at least one of the tetracarboxylic dianhydride compound and the diamine compound has a different structure from the tetracarboxylic dianhydride compound (a) and the diamine compound (b) used to form the polyamide acid polymer; 5) Polyimide polymer, tetracarboxylic dianhydride compound and diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and diamine compound is combined with the tetracarboxylic acid dianhydride compound used to form the polyimide polymer The structure of the carboxylic dianhydride compound (a) and the diamine compound (b) is different; (6) polyamide acid polymer, polyimide polymer, tetracarboxylic dianhydride compound and diamine compound, of which, At least one of the tetracarboxylic dianhydride compound and the diamine is in phase with the tetracarboxylic dianhydride compound (a) and the diamine compound (b) used to form the polyamide acid polymer or the polyimide polymer Different; (7) Two kinds of structurally different polyamide acid polymers, tetracarboxylic dianhydride compounds and diamine compounds; (8) Two kinds of structurally different polyimide polymers, tetracarboxylic dianhydride Compounds and diamine compounds; (9) Two kinds of polyamide acid polymers and diamine compounds whose end groups are acid anhydride groups and have different structures; (10) Two kinds of polyamides whose end groups are amine groups and have different structures Acid polymers and tetracarboxylic dianhydride compounds; (11) Two kinds of polyimide polymers and diamine compounds with acid anhydride groups and different structures; (12) Two kinds of end groups are amine groups and have the same structure Heteropolyimide polymers and tetracarboxylic dianhydride compounds.

In the range that does not affect the efficacy of the present invention, preferably, the polyimide polymer, the polyimide polymer and the polyimine-based block copolymer may be the terminal after the molecular weight is adjusted first. Modified polymer. By using end-modified polymers, the coating performance of the liquid crystal alignment agent can be improved. The method of preparing the terminal modified polymer can be prepared by adding a monofunctional compound while the polycondensation reaction of the polyamide acid polymer is carried out. The monofunctional compound may include but is not limited to (1) monobasic anhydride , Such as: maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride or n-hexadecyl succinic anhydride, etc. (2) Monoamine compounds, such as: aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n- Monoamines such as dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine or n-eicosylamine Compound; (3) Monoisocyanate compounds, such as monoisocyanate compounds such as phenyl isocyanate or naphthyl isocyanate.

The polymer (A) of the present invention has a weight average molecular weight of 10,000 to 90,000, preferably 12,000 to 75,000, and more preferably 15,000 to 60,000 in terms of polystyrene as measured by gel permeation chromatography.

Solvent (B)

The preferred specific examples of the solvent (B) according to the present invention are nitrogen-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl Base ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl Ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, nitrogen, nitrogen-dimethylformamide , Nitrogen, Nitrogen-Dimethylacetamide. The solvent can be used singly or in a mixture of plural kinds.

Based on 100 parts by weight of the polymer (A), the solvent (B) may be used in an amount of 500 to 3,000 parts by weight, preferably 800 to 2,500 parts by weight, and more preferably 1,000 to 2,000 parts by weight.

Additive (C)

In the range that does not affect the efficacy of the present invention, the liquid crystal alignment agent can be optionally added with the additive (C), and the additive (C) is an epoxy compound or a silane compound with a functional group. The function of the additive (C) is to improve the adhesion of the liquid crystal alignment film to the surface of the substrate. Additives (C) can be used alone or in combination of plural kinds.

The aforementioned epoxy compounds may include, but are not limited to, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl Glycol Diglycidyl Ether, 1,3,5,6-Tetraglycidyl-2,4-Hexanediol, N,N,N',N'-Tetraglycidyl-M-Di Toluene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraepoxypropyl-4,4'-di Amino diphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyl trimethoxysilane, 3-(N,N-diglycidyl)aminopropyl trimethyl Oxysilane, etc.

Based on the usage amount of the polymer (A) being 100 parts by weight, the usage amount of the epoxy compound is generally 40 parts by weight or less, and preferably 0.1 to 30 parts by weight.

The above-mentioned silane compounds with functional groups may include, but are not limited to, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2- Aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl 3-ureidopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane Triethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyl trimethylenetriamine, N-trimethoxysilylpropyl trimethylene Triamine, 10-trimethoxysilyl-1,4,7-triazedane, 10-triethoxysilyl-1,4,7-triazedane, 9-trimethoxysilyl- 3,6-Diazinonyl acetate, 9-triethoxysilyl-3,6-diazenonyl 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, etc.

Based on the usage amount of the polymer (A) being 100 parts by weight, the usage amount of the silane compound is generally 10 parts by weight or less, and preferably 0.5 to 10 parts by weight.

Based on the usage amount of the polymer (A) being 100 parts by weight, the usage amount of the additive (C) may generally be 50 parts by weight or less, and preferably 0.1 to 30 parts by weight.

Method for preparing liquid crystal alignment agent

The preparation method of the liquid crystal alignment agent of the present invention is not particularly limited, and general mixing methods can be used, such as first mixing the tetracarboxylic dianhydride compound (a) and the diamine compound (b) uniformly to react to form a polymer (A). Next, the polymer (A) is added to the solvent (B) at a temperature of 0°C to 200°C, and optionally the additive (C) is added, and the stirring device is used to continue stirring until it is dissolved. Preferably, the solvent (B) is added to the polymer composition at a temperature of 20°C to 60°C.

Generally speaking, at 25° C., the viscosity of the liquid crystal alignment agent of the present invention can be 10 cps to 90 cps, preferably 15 cps to 80 cps, and more preferably 20 cps to 70 cps.

Method for preparing liquid crystal alignment film

The present invention also provides a liquid crystal alignment film, which is manufactured from the aforementioned liquid crystal alignment agent.

Preferably, the preparation method of the liquid crystal alignment film includes: applying the above-mentioned liquid crystal alignment agent to a substrate by roll coating, spin coating, printing, ink-jet, etc. On the surface, a pre-coating layer is formed, and then the pre-coating layer is subjected to pre-bake treatment, post-bake treatment and alignment treatment to obtain the liquid crystal of the present invention Alignment film.

The purpose of the preheating treatment is to volatilize the organic solvent in the precoat. Preferably, the operating temperature range of the pre-heating treatment is 30°C to 120°C, more preferably 40°C to 110°C, and still more preferably 50°C to 100°C.

The above-mentioned alignment treatment is not particularly limited. It can be made of nylon, rayon, cotton and other fibers, wound on the drum and rubbed in a certain direction for alignment. The above-mentioned alignment processing is well known to those skilled in the art, so it will not be repeated.

The purpose of the post-heating treatment step is to make the polymer in the pre-coating layer undergo further dehydration and ring-closure (imidization) reaction. Preferably, the operating temperature range of the post-heating treatment is 150°C to 300°C, more preferably 180°C to 280°C, and more preferably 200°C to 250°C.

Method for preparing liquid crystal display element

The present invention also provides a liquid crystal display element, which includes the aforementioned liquid crystal alignment film.

The preparation method of the liquid crystal display element is well-known in the art, therefore, the following is only briefly described.

Please refer to FIG. 1, which shows a side view of a liquid crystal display device according to an embodiment of the present invention. A preferred embodiment of the liquid crystal display element 100 of the present invention includes a first cell 110, a second cell 120, and a liquid crystal cell 130. The second cell 120 is spaced apart from the first cell 110, and the liquid crystal cell 130 is disposed between the first cell 110 and the liquid crystal cell 130. Between the second unit 120.

The first unit 110 includes a first substrate 112, an electrode 114, and a first liquid crystal alignment film 116. The electrode 114 is formed on the surface of the first substrate 112 in a comb-tooth pattern, and the first liquid crystal alignment film 116 is formed on the electrode. The surface of 114.

The second unit 120 includes a second substrate 122 and a second liquid crystal alignment film 126, wherein the second liquid crystal alignment film 126 is formed on the surface of the second substrate 122.

The first substrate 112 and the second substrate 122 are selected from transparent materials and the like. Among them, the transparent material may include, but is not limited to, alkali-free glass, soda lime glass, hard glass (Pyles glass), quartz glass, polyethylene terephthalate, and polybutylene terephthalate used in liquid crystal display devices. Formate, polyether block, polycarbonate, etc. The material of the electrode 114 is a transparent electrode selected from tin oxide (SnO ₂ ), indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), etc.; or a metal electrode such as chromium.

The first liquid crystal alignment film 116 and the second liquid crystal alignment film 126 are the above-mentioned liquid crystal alignment films respectively, and their function is to make the liquid crystal cell 130 form a pretilt angle, and the liquid crystal cell 130 can be driven by the parallel electric field generated by the electrode 114.

The liquid crystal used in the liquid crystal unit 130 may be a single liquid crystal material or a mixture of multiple liquid crystal materials. The liquid crystals may include, but are not limited to, diaminobenzene-based liquid crystals, pyridazine-based liquid crystals, shiff base-based liquid crystals, azoxy-based liquid crystals, phenylcyclohexane-based liquid crystals, Biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, Dioxane type liquid crystal, bicyclooctane type liquid crystal, cubane type liquid crystal, etc., and can be added as required, such as cholesterol chloride and cholesterol nonanoate , Cholesterol-based liquid crystals such as cholesterol carbonate, or chiral agents with the trade names "C-15" and "CB-15" (manufactured by Merck), or decyloxy Strong ferroelectric liquid crystals such as benzyl-p-amino-2-methylbutyl cinnamate.

The liquid crystal display element produced by the liquid crystal alignment agent of the present invention is suitable for various types of nematic liquid crystals, such as liquid crystal display elements such as TN, STN, TFT, VA, and IPS. In addition, depending on the selected liquid crystal, it can also be used for liquid crystal display elements with different strong dielectric properties or anti-strong dielectric properties. Among the above-mentioned liquid crystal display elements, it is particularly suitable for IPS type liquid crystal display elements.

The following uses several embodiments to illustrate the application of the present invention, but they are not intended to limit the present invention. Those with ordinary knowledge in the technical field of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Retouch.

100‧‧‧LCD display element

110‧‧‧Unit 1

112‧‧‧First substrate

114‧‧‧electrode

116‧‧‧The first liquid crystal alignment film

120‧‧‧Unit 2

122‧‧‧Second substrate

126‧‧‧Second liquid crystal alignment film

130‧‧‧LCD unit

In order to have a more complete understanding of the embodiments of the present invention and its advantages, please refer to the above description and cooperate with the corresponding drawings. It must be emphasized that the various features are not drawn to scale and are for illustration purposes only. The contents of the related drawings are described as follows: [FIG. 1] shows a side view of a liquid crystal display device according to an embodiment of the present invention.

Preparation of polymer (A)

The following is a comparison of synthesis examples A-1-1 to A-1-20 and A-2-1 to A-2-4 and synthesis examples A'-1-1 to A'-1-4 according to Table 1 A'-2-1 to A'-2-2 polymer (A).

Synthesis Example A-1-1

A four-necked conical flask with a volume of 500 ml is equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer, and nitrogen is introduced. Then, 0.541 g (0.005 mol) of p-diaminobenzene (b-3-1), 8.922 g (0.045 mol) of 4,4'-diaminodiphenylmethane (b-3-2 ) And 80 grams of N-methyl-2-pyrrolidone (hereinafter referred to as NMP), and stir at room temperature until dissolved. Then, 1.815 g (0.0025 mol) of the tetracarboxylic dianhydride compound (a-1-1) represented by formula (I-5) and 10.361 g (0.0475 mol) of pyromellitic dianhydride were added (a-2-1) and 20 grams of NMP, and react at room temperature for 2 hours. After the reaction, the reaction solution was poured into 1500 ml of water to precipitate the polymer, the obtained polymer was filtered, and the steps of washing and filtering were repeated three times with methanol. After that, the product was placed in a vacuum oven and dried at a temperature of 60° C. to obtain the polymer (A-1-1) of Synthesis Example A-1-1.

Synthesis Examples A-1-2 to A-1-20 and Comparative Synthesis Examples A'-1-1 to A'-1-4

Synthesis Examples A-1-2 to A-1-20 and Comparative Synthesis Examples A'-1-1 to A'-1-4 use the same preparation method as the preparation method of the polymer of Synthesis Example A-1-1 , The difference is that Synthesis Examples A-1-2 to A-1-20 and Comparative Synthesis Examples A'-1-1 to A'-1-4 are based on changing the type and amount of raw materials in the polymer, and the formula is as As shown in Table 1, it will not be repeated here.

Synthesis Example A-2-1

A four-necked conical flask with a volume of 500 ml is equipped with a nitrogen inlet, agitator, heater, condenser and thermometer, and nitrogen is introduced. Then, 0.541 g (0.005 mol) of p-diaminobenzene (b-3-1), 8.922 g (0.045 mol) of 4,4'-diaminodiphenylmethane (b-3-2 ) And 80 grams of NMP, and stir at room temperature until dissolved. Then, 1.815 g (0.0025 mol) of the tetracarboxylic dianhydride compound (a-1-1) represented by formula (I-5) and 10.361 g (0.0475 mol) of pyromellitic dianhydride were added (a-2-1) and 20 grams of NMP. After reacting at room temperature for 6 hours, 97 g of NMP, 2.55 g of acetic anhydride and 19.75 g of pyridine were added, the temperature was raised to 60° C., and stirring was continued for 2 hours to proceed the imidization reaction. After the reaction, the reaction solution was poured into 1500 ml of water to precipitate the polymer, the obtained polymer was filtered, and the steps of washing and filtering were repeated three times with methanol. After that, the product was placed in a vacuum oven and dried at a temperature of 60° C. to obtain the polymer (A-2-1) of Synthesis Example A-2-1.

Synthesis Examples A-2-2 to A-2-4 and Comparative Synthesis Examples A'-2-1 to A'-2-2

Synthesis Examples A-2-2 to A-2-4 and Comparative Synthesis Examples A'-2-1 to A'-2-2 use the same preparation method as the preparation method of the polymer of Synthesis Example A-2-1 , The difference is that Synthesis Examples A-2-2 to A-2-4 and Comparative Synthesis Examples A'-2-1 to A'-2-2 are based on changing the types and usage of the raw materials in the polymer. The formula is as follows As shown in Table 1, it will not be repeated here.

Preparation of liquid crystal alignment agent

The following is the preparation of liquid crystal alignment agents of Examples 1 to 24 and Comparative Examples 1 to 8 according to Tables 2 and 3.

Example 1

100 parts by weight of the polymer (A-1-1) prepared in the aforementioned synthesis example A-1-1 was added to 800 parts by weight of N-methyl-2-pyrrolidone (hereinafter referred to as B-1), The liquid crystal alignment agent of Example 1 can be prepared by continuously stirring with a stirring device at room temperature to dissolve. The obtained liquid crystal alignment agent was evaluated by the following evaluation method, and the results are shown in Table 2, in which the detection method of viscosity and Young's modulus will be described later.

Examples 2 to 24 and Comparative Examples 1 to 8

Examples 2 to 24 and Comparative Examples 1 to 8 used the same preparation method as that of the liquid crystal alignment agent of Example 1, except that Examples 2 to 24 and Comparative Examples 1 to 8 changed the liquid crystal alignment agent The types and amounts of raw materials used, their formulations and evaluation results are shown in Tables 2 and 3, respectively.

Evaluation method 1. Viscosity

At 25°C, using a rotary viscometer (model DV-E, manufactured by BROOKFIELD) at 100 rpm, the liquid crystal alignment agent prepared in the foregoing Examples 1 to 24 and Comparative Examples 1 to 8 was measured Viscosity (in cps).

2. Young's modulus

Using the spin coating method, the liquid crystal alignment agents prepared in the foregoing Examples 1 to 24 and Comparative Examples 1 to 8 were coated on the glass substrate to form a coating layer. Next, the glass substrate was placed on a hot plate, and a pre-baking treatment was performed under the conditions of a temperature of 80°C and a time of 2 minutes. Next, in a circulating oven, a post-bake treatment was performed under the conditions of a temperature of 235°C and a time of 15 minutes. After the alignment treatment, a liquid crystal alignment film with a thickness of 100 nm can be prepared. Then, a nanoindenter (NanoIndenter, model: MTS NanoIndenter G200, manufactured by Agilent) was used to measure the Young's modulus (E, unit of GPa) of the prepared liquid crystal alignment film. Among them, the probe of the nanoindentation tester uses triangular pyramidal diamonds, and the measurement is performed under the conditions of a measurement frequency of 45MHz, a penetration depth of 20nm, and a measurement temperature of 23°C. The measured Young's modulus is evaluated based on the following criteria:

◎: E≧8GPa.

○: 8GPa>E≧6GPa.

△: 6GPa>E≧4GPa.

×: 4GPa>E.

Wherein, when the evaluation result of the Young's modulus of the liquid crystal alignment film is ⊚, the liquid crystal display element prepared by the liquid crystal alignment film does not have any broken bright spots; when the evaluation result of the Young's modulus of the liquid crystal alignment film is ○ , The liquid crystal display element made of this liquid crystal alignment film only has a few broken bright spots; when the evaluation result of the Young's modulus of the liquid crystal alignment film is △ or ×, the liquid crystal display element made of this liquid crystal alignment film has a lot of Broken bright spots are generated, and as the Young's modulus decreases, the number of broken bright spots is increased.

From the results in Tables 2 and 3, it can be seen that when the liquid crystal alignment agent of the present invention does not contain the tetracarboxylic dianhydride compound (a-1) represented by formula (I), the Young's mode of the liquid crystal alignment film produced The amount is too low, and the liquid crystal display element containing the liquid crystal alignment film has a large number of defects caused by broken bright spots.

When Z in the tetracarboxylic dianhydride compound (a-1) represented by formula (I) represents -CONH- or -NHCO-, the resulting liquid crystal alignment film has a higher Young's modulus, and can Further improve the broken bright spots of liquid crystal display elements.

Secondly, if the diamine compound (b) of the polymer (A) contains the diamine compound (b-1) represented by the formula (II), the liquid crystal alignment film prepared by the liquid crystal alignment agent has a higher Young’s Modulus, and can further improve the broken bright spots of liquid crystal display elements.

Furthermore, if the diamine compound (b) of the polymer (A) contains the diamine compound (b-2) represented by the formula (III), the liquid crystal alignment film prepared by the liquid crystal alignment agent has a higher The modulus of the liquid crystal display element can be further improved.

It should be added that although the present invention uses specific compounds, compositions, reaction conditions, manufacturing processes, analytical methods or specific instruments as examples to illustrate the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element of the present invention, the technical field of the present invention Anyone with ordinary knowledge in the invention can know that the present invention is not limited to this. Without departing from the spirit and scope of the present invention, the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element of the present invention can also use other compounds, compositions, and reactions. Conditions, processes, analytical methods or instrumentation.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Retouching, therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

Claims (12)

A liquid crystal alignment agent comprising: a polymer (A) obtained by reacting a tetracarboxylic dianhydride compound (a) and a diamine compound (b), wherein the tetracarboxylic dianhydride compound (a) comprises the following formula Tetracarboxylic dianhydride compound (a-1) shown in (I):

In the formula (I), the R ₁ , the R ₂ , the R ₃ , the R ₄ , the R ₅ and the R ₆ are each independently selected from halogen atoms, substituted or unsubstituted alkyl groups, and At least one of a group consisting of a substituted or unsubstituted alkoxy group and a substituted or unsubstituted aromatic group; the Z each independently represents -CONH-, -NHCO-, -NHCO ₂ -, -OCONH- or- NHCONH-; the h, the i, the j, and the k each independently represent an integer from 0 to 4; the m and the n each independently represent an integer from 0 to 3; and a solvent (B), where 25 At °C, one of the liquid crystal alignment agents has a viscosity of 10 cps to 90 cps. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the Z represents -CONH- or -NHCO-. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the diamine compound (b) comprises a diamine compound (b-1) represented by formula (II):

In the formula (II), the W ₁ represents a cycloalkylene group with a carbon number of 4 to 6 substituted by a tertiary nitrogen atom, and the W ₂ represents an alkylene group with a carbon number of 1 to 5. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the diamine compound (b) comprises a diamine compound (b-2) represented by formula (III):

In formula (III), the y represents an integer of 1-12. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the viscosity of the liquid crystal alignment agent is 15 cps to 80 cps. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the viscosity of the liquid crystal alignment agent is 20 cps to 70 cps. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein the total usage amount based on the polymer (A) is 100 parts by weight, and the usage amount of the solvent (B) is 500 parts by weight to 3000 parts by weight. The liquid crystal alignment agent described in item 1 of the scope of patent application, wherein based on the total usage amount of the tetracarboxylic dianhydride compound (a) is 100 mol, the usage amount of the tetracarboxylic dianhydride compound (a-1) It ranges from 5 mol to 60 mol. The liquid crystal alignment agent described in item 3 of the scope of patent application, wherein based on the total usage amount of the diamine compound (b) is 100 mol, the usage amount of the diamine compound (b-1) is 3 mol to 45 mol Mol. The liquid crystal alignment agent described in item 4 of the scope of patent application, wherein based on the total usage amount of the diamine compound (b) is 100 mol, the usage amount of the diamine compound (b-2) is 10 mol to 95 mol Mol. A liquid crystal alignment film, comprising the liquid crystal alignment agent described in any one of items 1 to 10 in the scope of the patent application. A liquid crystal display element includes the liquid crystal alignment film as described in item 11 of the scope of patent application.

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