TWI834894B - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

The present invention provides 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 manufactured by a specific diamine component (b). The liquid crystal alignment film is formed form the liquid crystal alignment agent, and the liquid crystal display element including the liquid crystal alignment film has a lower flicker level after the element is driven.

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. In particular, it relates to a liquid crystal display element that utilizes the liquid crystal alignment agent to produce a liquid crystal display element with a better degree of flickering immediately after driving.

Liquid crystal display elements used in LCD TVs, LCD monitors, etc. usually have a liquid crystal alignment film inside the element for controlling the alignment state of the liquid crystal. At present, the most common method in the industry is to rub cotton, nylon, polyester and other cloth materials in one direction to form on the electrode substrate, which is formed by polyamide acid and/or polyimide. The film surface is subjected to a so-called rubbing treatment to obtain the liquid crystal alignment film.

During the alignment process of the liquid crystal alignment film, rubbing the film surface is a method that is easier to produce in industry. However, as the requirements for high performance, high precision, and large size of liquid crystal display elements are getting higher and higher, during the rubbing treatment, the alignment film surface is damaged, flying dust, mechanical force and electrostatic force are affected. The resulting effects and various problems such as unevenness on the alignment surface have become more significant.

As a method that replaces the rubbing treatment, a photo-alignment method that uses polarized ultraviolet irradiation to impart alignment energy to liquid crystals is currently known. The so-called liquid crystal alignment treatment of the photoalignment method refers to substances that utilize photoisomerization reaction, photocrosslink reaction, photodecomposition reaction, etc. in the reaction mechanism. Furthermore, Japanese Patent Application Laid-Open No. 9-297313 proposes a photoalignment method using a polyimide film having an alicyclic structure such as cyclobutane or the like in the main chain. When using polyimide as an alignment film for photo-alignment, the applicability of this alignment film is promising because the heat resistance of this alignment film is higher than other types of alignment films.

The optical alignment method is a friction-free alignment treatment method. It not only has the advantage of being manufactured with a simple process in industry, but also has the advantages of in-plane-switching (IPS) driving mode and boundary electric field switching wide viewing angle technology (In-Plane-Switching; IPS). In liquid crystal display elements driven by Fringe Field Switching (FFS), compared with liquid crystal alignment films obtained by rubbing treatment, using the liquid crystal alignment film obtained by the above-mentioned photo alignment method is expected to improve the contrast and viewing angle characteristics of the liquid crystal display element. , so the photo-alignment method is a promising and attention-grabbing liquid crystal alignment treatment method.

However, when the liquid crystal alignment film produced by the photo-alignment method is applied to a liquid crystal display element, the produced liquid crystal display element still has a problem of poor flickering immediately after driving. From the above, it can be seen that in order to meet the current requirements of photo-aligned IPS LCD manufacturers, it is the goal of those in this technical field to provide a liquid crystal alignment agent that can form a liquid crystal display element with a better degree of flicker immediately after driving.

One aspect of the present invention provides a liquid crystal alignment agent, which includes a polymer (A) and a solvent (B). This liquid crystal alignment agent can improve the flickering degree of the produced liquid crystal display element immediately after driving. In addition, the liquid crystal alignment agent of the present invention may optionally contain additive (C).

Another aspect of the present invention is to provide a liquid crystal alignment film, which is formed using the above-mentioned liquid crystal alignment agent.

Another aspect of the present invention is to provide a liquid crystal display element, which includes the above-mentioned liquid crystal alignment film.

According to the above aspect of the present invention, a liquid crystal alignment agent is proposed, and the liquid crystal alignment agent includes a polymer (A) and a solvent (B). Polymer(A)

The polymer (A) of the present invention is prepared by reacting the tetracarboxylic dianhydride component (a) and the diamine component (b).

Preferable specific examples of the polymer (A) are polyamic acid polymers, polyimide polymers, polyimide block copolymers, or combinations thereof. Among them, preferred specific examples of polyamide block copolymers are polyamide acid block copolymers, polyamide block copolymers, and polyamide acid-polyamide block copolymers. polymer or any combination thereof. Tetracarboxylic dianhydride component (a) Tetracarboxylic dianhydride compound (a-1)

The tetracarboxylic dianhydride component (a) of the present invention contains at least one tetracarboxylic dianhydride compound (a-1), which has a structure represented by the following formula (1): (1) In formula (1), R ₁ to R ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. 6 alkynyl group, a monovalent organic group containing a fluorine atom and having a carbon number of 1 to 6, or a phenyl group, R ₁ to R ₄ may be the same or different, and at least one of R ₁ , R ₂ , R ₃ and R ₄ One is not a hydrogen atom.

In the case where R ₁ , R ₂ , R ₃ and R ₄ have a three-dimensional barrier structure, the prepared liquid crystal alignment agent will cause poor flickering of the formed liquid crystal display element immediately after driving. Therefore, R ₁ , R ₂ , R ₃ and R ₄ are preferably a hydrogen atom, a methyl group or an ethyl group, with a methyl group being more preferred.

Specific examples of the tetracarboxylic dianhydride compound (a-1) having a structure represented by formula (1) include compounds represented by the following formulas (1-1) to formula (1-8). Regarding the degree of flicker immediately after driving, formula (1-1) is the better one. (1-1) (1-2) (1-3) (1-4) (1-5) (1-6) (1-7) (1-8)

The above-mentioned tetracarboxylic dianhydride compound (a-1) can be used alone or in mixture of a plurality of types.

Based on the total usage amount of tetracarboxylic dianhydride component (a) being 100 moles, the usage amount of tetracarboxylic dianhydride compound (a-1) is 10 moles to 100 moles, preferably 20 moles to 80 moles, and more preferably 30 moles to 70 moles.

If the tetracarboxylic dianhydride component (a) contains the tetracarboxylic dianhydride compound (a-1), the degree of flickering of the formed liquid crystal display element immediately after driving can be further reduced. Other tetracarboxylic dianhydride compounds (a-2)

The tetracarboxylic dianhydride component (a) of the present invention may optionally contain other tetracarboxylic dianhydride compounds (a-2). Preferable specific examples of other tetracarboxylic dianhydride compounds (a-2) are (1) aliphatic tetracarboxylic dianhydride compounds, (2) alicyclic tetracarboxylic dianhydride compounds, (3) aromatic tetracarboxylic acids The dianhydride compound or (4) a tetracarboxylic dianhydride compound represented by formula (1-1) to formula (1-6), etc.

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

(2) Alicyclic tetracarboxylic dianhydride compounds of the present invention include but are not limited to 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2-dimethyl-1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic 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-cyclopentane Tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutyl Cycloheptyl-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride or bicyclo[2.2.2]-octyl -Alicyclic tetracarboxylic dianhydride compounds such as 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-tetralin-1-succinic dianhydride, benzene Tetracarboxylic dianhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3' ,4,4'-biphenyl tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3'- 4,4'-diphenylethane tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetracarboxylic dianhydride 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'-perfluoroisopropylidenediphthalic dianhydride, 2,2', 3,3'-diphenyltetracarboxylic dianhydride, 2,3,3',4'-diphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride Anhydride, 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(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis (dehydrated trimellitate), propylene glycol-bis(dehydrated trimellitate), 1,4-butanediol-bis(dehydrated 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-tetrahydrofuran tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dilateral oxy-3-furyl)- Naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dione Pendant oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5 -(Tetrahydro-2,5-dilateral oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b -Hexahydro-7-methyl-5-(tetrahydro-2,5-bisoxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1 ,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-bisoxy-3-furyl)-naphtho[1,2-c]- Furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-bisoxy-3-furyl)- Naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-dione Pendant oxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl Base-5-(tetrahydro-2,5-bisoxy-3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 5-(2,5-di Side oxygen group (tetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, etc.

(4) according to the present invention has a tetracarboxylic dianhydride compound represented by formula (2-1) to formula (2-6), which will be described in detail below. (2-1) (2-2) (2-3) (2-4) (2-5) (2-6)

In formula (2-5), R ₅ represents a divalent group containing an aromatic ring; r represents an integer from 1 to 2; R ₆ and R ₇ can be the same or different, and can respectively represent a hydrogen atom or an alkyl group. Preferably, the tetracarboxylic dianhydride compound represented by formula (2-5) can be selected from the compounds represented by the following formula (2-5-1) to formula (2-5-3). (2-5-1) (2-5-2) (2-5-3)

In formula (2-6), R ₈ represents a divalent group containing an aromatic ring; R ₉ and R ₁₀ can be the same or different, and represent a hydrogen atom or an alkyl group respectively. Preferably, the tetracarboxylic dianhydride compound represented by formula (2-6) can be selected from the compounds represented by the following formula (2-6-1). (2-6-1)

The above-mentioned other tetracarboxylic dianhydride compounds (a-2) can be used singly or in mixture of plural types.

Based on the total usage amount of tetracarboxylic dianhydride component (a) is 100 moles, the usage amount of other tetracarboxylic dianhydride compounds (a-2) is 0 moles to 90 moles, preferably 20 moles to 80 moles, and more preferably 30 moles to 70 moles.

Based on the usage amount of diamine component (b) being 100 moles, the usage amount of tetracarboxylic dianhydride component (a) ranges from 20 moles to 200 moles, and preferably from 30 moles to 120 moles. Diamine component (b) Diamine compound (b-1)

The diamine component (b) of the present invention includes at least one diamine compound (b-1), which has a structure represented by the following formula (I).

In formula (I), Z ₁ to Z ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and an alkyne having 2 to 6 carbon atoms. group, a monovalent organic group containing fluorine atoms and having a carbon number of 1 to 6, or a phenyl group containing a fluorine atom and having a carbon number of 6, Z ₁ to Z ₄ may be the same or different, and Z ₁ , Z ₂ , At least one of Z ₃ and Z ₄ is not a hydrogen atom; Y ₁ to Y ₄ each independently represents a single bond, -O-, -S-, -NZ ₅ -, ester group, amide group, thioester group, Urea group, carbonate group or carbamate group, in which Z ₅ represents a hydrogen atom or a methyl group, Y ₁ to Y ₄ can be the same or different; A ₁ and A ₂ represent extensions with a carbon number of 2 to 20. Alkyl group, wherein A ₁ and A ₂ can be the same or different; X ₁ to X ₄ each independently represent a divalent organic group selected from the structure shown in the following formula (II-1) to formula (II-6) Group, where X ₁ and X ₂ are not of the same structure, and X ₃ and X ₄ are not of the same structure.

In formula (II-1), Z ₆ represents a substituted or unsubstituted divalent cyclic group of benzene ring, cyclohexane ring or heterocyclic ring. The hydrogen atom on the divalent cyclic group can be replaced by a carbon number. Substituted by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having a carbon number of 1 to 3, an alkyl group containing a fluorine atom and having a carbon number of 1 to 3, or an alkoxy group containing a fluorine atom and having a carbon number of 1 to 3; m represents 1 to 5; and in formula (II-2), Z ₇ represents an alkylene group having 1 to 5 carbon atoms.

Specifically, the divalent organic group of the structure represented by the above formula (II-1) can be, for example, compounds represented by the following formula (II-1-1) to formula (II-1-11): (II-1-1) (II-1-2) (II-1-3) (II-1-4) (II-1-5) (II-1-6) (II-1-7) (II-1-8) (II-1-9) (II-1-10) (II-1-11) In the formula (II-1-11), R ₁₁ represents a hydrogen atom, a methyl group, a hydroxyl group or a methoxy group.

Secondly, in formula (I), Z ₁ to Z ₄ are preferably hydrogen atoms, methyl groups, and monovalent organic groups containing fluorine atoms and having a carbon number of 1 to 2, among which Z ₁ has a sterically hindered structure. The liquid crystal alignment agent prepared to Z ₄ will cause the formed liquid crystal display element to have poor flicker immediately after being driven. Therefore, more preferably, Z ₁ and Z ₄ are methyl groups and the remaining two are hydrogen atoms, or Z ₂ and Z ₃ are methyl groups and the remaining two are hydrogen atoms.

Furthermore, in formula (I), Y ₁ to Y ₄ are each preferably a single bond, -O-, -S-, -NZ ₅ -, ester group or amide group, and more preferably -O-. Secondly, based on the perspective of liquid crystal alignment, A ₁ and A ₂ preferably represent an alkylene group with a carbon number of 2 to 6, and more preferably an alkylene group with a carbon number of 2 to 4.

In formula (II-2), Z ₇ preferably represents an alkylene group with a carbon number of 1 to 3, and in formula (II-1-11), R ₁₁ preferably represents a hydrogen atom or a methyl group.

In the aforementioned formula (I), if X ₁ and X ₂ have the same structure, or X _{3 and} Not good.

In some embodiments, one of X ₁ and X ₂ and one of X ₃ and X ₄ respectively represent a structure shown in formula (II-1), and m is 1; and X ₁ and X ₂ The other one and the other one of X ₃ and X ₄ respectively represent the structures shown in formula (II-1) to formula (II-6), and m represents 2 to 5.

In the case where the diamine compound (b-1) has the structure shown in the above formula (I), in the aforementioned formula (I), when one of X ₁ and X ₂ and one of X ₃ and X ₄ has the structure shown in formula (II-1) that satisfies the condition that m is 1, and the other of X ₁ and X ₂ and the other of X ₃ and X ₄ have the structure that satisfies the condition that m is 2 to When the structure represented by formula (II-1) or the structure represented by formula (II-2) to formula (II-6) is obtained under the conditions of 5, the prepared liquid crystal alignment agent can further reduce the formation of liquid crystal display The degree of flicker immediately after the component is driven.

Specific examples of the diamine compound (b-1) represented by the aforementioned formula (I) may include, but are not limited to, diamine compounds represented by the following formulas (I-1-A) to formula (I-43).

Preferably, specific examples of the aforementioned diamine compound (b-1) having a structure represented by formula (I) may include but are not limited to those represented by the above formulas (I-1-A) to formula (I-39) compound.

The above-mentioned diamine compound (b-1) can be used alone or in mixture of a plurality of types.

Based on the total usage amount of diamine component (b) being 100 moles, the usage amount of diamine compound (b-1) is 3 moles to 30 moles, preferably 4 moles to 25 moles, and more The best value is 5 moles to 20 moles. If the diamine component (b) does not include the diamine compound (b-1), the prepared liquid crystal alignment agent will cause the formed liquid crystal display element to have poor flicker immediately after being driven. Diamine compound (b-2)

The diamine component (b) of the present invention may optionally include a diamine compound (b-2) represented by the following formula (III).

In formula (III), Z ₈ and Z ₁₄ each independently represent a single bond, -CH ₂ - or -CH ₂ CH ₂ -; Z ₁₀ and Z ₁₂ each independently represent -CH ₂ - or -CH ₂ CH ₂ -; Z ₁₁ represents an alkylene group with a carbon number of 1 to 6 or a cyclohexylene group with a carbon number of 6; Z ₉ and Z ₁₃ each independently represent a single bond, -O-, -NH-, -N( CH ₃ )-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C(=O)N(CH ₃ )-, -OC(=O) -, -NHC(=O)- or -N(CH ₃ )C(=O)-; Z ₁₅ represents a linear hydrocarbon group with a carbon number of 1 to 20, a branched chain hydrocarbon group with a carbon number of 3 to 20, or It has a cyclic hydrocarbon group with a carbon number of 3 to 20; and n represents 0 or 1.

In formula (III), Z ₈ and Z ₁₄ preferably represent a single bond or -CH ₂ -; Z ₁₀ and Z ₁₂ preferably represent -CH ₂ -. When Z ₈ and Z ₁₄ are identical, Z ₁₀ and Z ₁₂ are preferably different. When Z ₈ and Z ₁₄ are not identical, Z ₁₀ and Z ₁₂ are preferably identical.

In formula (III), Z ₉ and Z ₁₃ preferably represent single bonds, -O-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C (=O)N(CH ₃ )-, -OC(=O)-, -NHC(=O)- or N(CH ₃ )C(=O)-, Z ₉ and Z ₁₃ are preferably independently represents a single bond or -O-. When Z ₉ and Z ₁₃ independently represent a single bond or -O-, the prepared liquid crystal alignment agent can further reduce the degree of flickering of the formed liquid crystal display element immediately after driving.

From the viewpoint of raw material availability, Z ₁₅ may preferably be, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, benzyl, n- Hexadecyl or 9-benzoylmethyl. Based on the solubility and thermal dissociability of the polymer, Z ₁₅ is preferably, for example, t-butyl.

From the viewpoint of ease of synthesis, n is preferably 0.

Specific examples of the diamine compound (b-2) represented by the above formula (III) may include, but are not limited to, diamine compounds represented by the following formulas (III-1) to formula (III-46). In formulas (III-1) to formula (III-46), Me represents a methyl group; Et represents an ethyl group; i-Pr represents an i-propyl group; Bn represents a benzyl group; and Boc represents a tert-butoxycarbonyl group.

The aforementioned diamine compound (b-2) can be used alone or in mixture of a plurality of types.

Based on the total usage amount of diamine component (b) being 100 moles, the usage amount of diamine compound (b-2) is 1 mole to 10 moles, preferably 1 mole to 8 moles, and more The best value is 1 mol to 5 mol.

When the diamine component (b) includes the diamine compound (b-2), the prepared liquid crystal alignment agent can further reduce the degree of flickering of the formed liquid crystal display element immediately after driving. Other diamine compounds (b-3)

The diamine component (b) of the present invention may optionally contain other diamine compounds (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-diaminopropane Pentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminoheptane 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, isophoronediamine, tetrahydrodicyclopentadienediamine, tricyclo[6.2.1.0(2,7)]-undecenedimethyldiamine , 4,4'-methylenebis(cyclohexylamine), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diamine Diphenyl ester, 4,4'-diaminobenzoaniline, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,5-di Aminonaphthalene, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydrindane, 6-amino-1-(4'-aminophenyl)- 1,3,3-trimethylhydrindene, hexahydro-4,7-methylbenzoindenyldimethylenediamine, 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-aminophenoxy) )phenyl]trilane, 1,4-bis(4-aminophenoxy)cyclohexane, 1,5-bis(4-aminophenoxymethylene)adamantane, 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, 9,10-bis(4-aminophenyl)anthracene [9,10-bis(4-aminophenyl) anthracene], 2,7-diaminofluoride, 9, 9-Bis(4-aminophenyl)fluoride, 4,4'-methylene-bis(2-chloroaniline), 4,4'-(p-phenyleneisopropylidene)bisaniline, 4 ,4'-(m-phenyleneisopropylidene)bisaniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenyl Methylene-1,3-diaminobenzene{5-[4-(4-n-pentylcyclohexyl) cyclohexyl] phenylmethylene-1,3-diaminobenzene}, 1,1-bis[4-(4-aminobenzene) Oxy)phenyl]-4-(4-ethylphenyl)cyclohexane{1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane} or the following formula ( IV-1) to other diamine compounds represented by formula (IV-29).

In formula (IV-1), A ₃ represents , , , , or , and A ₄ represents a cyclic structure containing a sterol group, a trifluoromethyl group, a fluorine group, an alkyl group with 2 to 30 carbon atoms, or a nitrogen atom-containing ring structure derived from pyridine, pyrimidine, triazine, piperidine, piperazine, etc. Monovalent group.

Other diamine compounds represented by the above formula (IV-1) are preferably 2,4-diaminophenyl ethyl formate (2,4-diaminophenyl ethyl formate) and 3,5-diaminophenylcarboxylic acid. Ethyl ester (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-diaminobenzene (1-dodecoxy-2,4-diamino-benzene), 1-hexadecyloxy-2,4-diamine 1-hexadecoxy-2,4-diaminobenzene, 1-octadecoxy-2,4-diaminobenzene or the following formula (IV-1-1 ) to other diamine compounds represented by formula (IV-1-6). (IV-1-1) (IV-1-2) (IV-1-3) (IV-1-4) (IV-1-5) (IV-1-6)

In formula (IV-2), A ₅ represents , , , , or , A ₆ and A ₇ represent an aliphatic ring, an aromatic ring or a heterocyclic group, and A ₈ represents an alkyl group with a carbon number of 3 to 18, an alkoxy group with a carbon number of 3 to 18, a carbon number It is a fluoroalkyl group with 1 to 5 carbon atoms, a fluoroalkoxy group with 1 to 5 carbon atoms, a cyano group or a halogen atom.

Other diamine compounds represented by the above formula (IV-2) are preferably diamine compounds represented by the following formulas (IV-2-1) to formula (IV-2-13): (IV-2-1) (IV-2-2) (IV-2-3) (IV-2-4) (IV-2-5) (IV-2-6) (IV-2-7) (IV-2-8) (IV-2-9) (IV-2-10) (IV-2-11) (IV-2-12) (IV-2-13) In formula (IV-2-10) to formula (IV-2-13), s can represent an integer from 3 to 12.

In formula (IV-3), A ₉ represents a hydrogen atom, a hydroxyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen. P1 represents an integer from 1 to 3. When P1 is greater than 1, the plurality of A _9s may be the same or different.

The diamine compound represented by the above formula (IV-3) is preferably selected from (1) P1 is 1: p-diamine benzene, m-diamine benzene, o-diamine benzene or 2,5-diamine Toluene, etc.; (2) P1 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'-diaminobiphenyl , 3,3'-dichloro-4,4'-diaminobiphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-diamine Chloro-4,4'-diamino-5,5'-dimethoxybiphenyl or 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, etc.; (3 )P1 is 3: 1,4-bis(4'-aminophenyl)benzene, etc., preferably selected from p-diamine benzene, 2,5-diamine toluene, 4,4'-diamine Biphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl or 1,4-bis(4'-aminophenyl)benzene.

(IV-4) In the above formula (IV-4), P2 represents an integer from 1 to 5. The structure represented by formula (IV-4) is preferably selected from 4,4'-diaminodiphenyl sulfide.

(IV-5) In formula (IV-5), A ₁₀ and A ₁₂ can be the same or different, and respectively represent a divalent organic group. A ₁₁ represents a group derived from pyridine, pyrimidine, triazine, piperidine and piperidine. A bivalent group containing a nitrogen atom cyclic structure such as an azine.

(IV-6) In formula (IV-6), A ₁₃ , A ₁₄ , A ₁₅ and A ₁₆ may be the same or different respectively, and may represent a hydrocarbon group with a carbon number of 1 to 12. P3 represents an integer from 1 to 3, and P4 represents an integer from 1 to 20.

(IV-7) In formula (IV-7), A ₁₇ represents Or cyclohexyl, A ₁₈ represents , A ₁₉ represents a phenylene group or a cyclohexylene group, and A ₂₀ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

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

Other diamine compounds represented by formula (IV-8) to formula (IV-29) are as follows: (IV-8) (IV-9) (IV-10) (IV-11) (IV-12) (IV-13) (IV-14) (IV-15) (IV-16) (IV-17) (IV-18) (IV-19) (IV-20) (IV-21) (IV-22) (IV-23) (IV-24) (IV-25) (IV-26) (IV-27) (IV-28) (IV-29) In formulas (IV-16) to formula (IV-19), A ₂₁ is preferably an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. In formulas (IV-20) to formula (IV-24), A ₂₂ 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) preferably include but are not limited to 1,2-diaminoethane, 4,4'-diaminodicyclohexylmethane, and 4,4'-diaminodiphenyl Methane, 4,4'-diaminodiphenyl ether, 5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene, 1, 3-bis(3-aminophenoxy)benzene, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane, 2 , ethyl 4-diaminophenylformate, p-diaminebenzene, m-diaminebenzene, o-diaminebenzene, formula (IV-1-1), formula (IV-1-2), formula ( IV-1-5), formula (IV-2-1), formula (IV-2-11), formula (IV-7-1), formula (IV-25) or formula (IV-28) compound.

The aforementioned other diamine compounds (b-3) can be used alone or in combination of a plurality of them.

Based on the total usage amount of diamine component (b) being 100 moles, the usage amount of other diamine compounds (b-3) is 60 moles to 96 moles, preferably 67 moles to 95 moles, and More preferably, it is 75 moles to 94 moles. Preparation method of polymer (A)

The preparation of the polyamic acid polymer of the present invention can be a general method. Preferably, the preparation method of the aforementioned polyamic acid polymer includes the following steps: combining the tetracarboxylic dianhydride component (a) and the diamine The mixture of component (b) is dissolved in the solvent, and the polycondensation reaction is carried out at a temperature of 0°C to 100°C for 1 hour to 24 hours, and then the above reaction solution is distilled under reduced pressure using an evaporator. Polyamic 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 aforementioned precipitate is dried through reduced pressure drying to obtain polyamic acid. polymer.

The solvent used in the polycondensation reaction may be the same as or different from the solvent (B) 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. Can. Preferably, the solvent includes but is not limited to (1) aprotic polar solvent, such as: N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide , aprotic polar solvents such as N,N-dimethylformamide, dimethyltrisoxide, γ-butyrolactone, tetramethylurea or hexamethyltriamine phosphate; (2) phenolic solvents, For example: phenolic solvents such as m-cresol, xylenol, phenol or halogenated phenols. Based on the usage amount of the mixture being 100 parts by weight, the usage amount of the solvent used in the polycondensation reaction is preferably 200 to 2000 parts by weight, more preferably 300 to 1800 parts by weight.

In particular, in the polycondensation reaction, the solvent can be combined with an appropriate amount of a poor solvent, wherein the poor solvent will not cause the polyamide polymer to precipitate. Lean solvents can be used alone or in combination, and include but are not limited to (1) alcohols, such as: methanol, ethanol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, and 1,4-butanediol. Alcohols such as alcohol or triethylene glycol; (2) Ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; (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 Ethers such as base ethers; (5) Halogenated hydrocarbons, such as: methylene chloride, 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 mixture being 100 parts by weight, the usage amount of the lean solvent is preferably 0 to 60 parts by weight, more preferably 0 to 50 parts by weight.

The polyimide polymer of the present invention can be prepared by a general method. Preferably, the polyimide polymer is prepared by first dissolving a mixture in a solution, wherein the mixture includes a tetracarboxylic dianhydride component (a ) and diamine component (b), and undergo a polymerization reaction to form a polyamide polymer. Then, in the presence of a dehydrating agent and a catalyst, further heating is performed, and a dehydration ring-closure reaction is performed, so that the amide functional groups in the polyamide polymer are converted into amide imine functional groups (i.e., amide imine functional groups) through the dehydration ring-closure reaction. Amination) to obtain polyimide polymer.

The solvent used in the dehydration ring-closure reaction can be the same as the solvent in the liquid crystal alignment agent described below, so no further description is given. Based on the usage amount of the polyamide polymer being 100 parts by weight, the usage amount of the solvent used in the dehydration ring-closure reaction is preferably 200 to 2000 parts by weight, more preferably 300 to 1800 parts by weight.

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

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

Preferable specific examples of the polyamide block copolymer of the present invention are polyamide block copolymers, polyamide block copolymers, and polyamide-polyamide block copolymers. Copolymers, or any combination thereof.

The polyimide block copolymer of the present invention can be prepared by a general method. Preferably, the polyimide block copolymer is prepared by first dissolving the starting material in a solvent, and then Polycondensation reaction, wherein the starter includes the above-mentioned at least one polyamide polymer and/or the above-mentioned at least one polyamide polymer, and may further include the tetracarboxylic dianhydride component (a) and diamine component (b).

The tetracarboxylic dianhydride component (a) and diamine component (b) in the aforementioned starting material are the same as the tetracarboxylic dianhydride component (a) and diamine component (b) used in the preparation of the polyamide polymer. The amine component (b) is the same, and the solvent used in the polycondensation reaction can be the same as the solvent in the liquid crystal alignment agent described below, which will not be described again here.

Based on the usage amount of the aforementioned starting material being 100 parts by weight, the usage amount of the solvent used in the polycondensation reaction is preferably 200 to 2000 parts by weight, more preferably 300 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 materials include but are not limited to (1) two polyamide polymers with different end groups and different structures; (2) two types of polyimides with different end groups and different structures. Polymers; (3) polyamic acid polymers and polyimide polymers with different terminal groups and different structures; (4) polyamic acid 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 component (a) and the diamine component (b) used to form the polyamic acid polymer. ; (5) Polyimide polymer, tetracarboxylic dianhydride compound and diamine compound, wherein at least one of the tetracarboxylic dianhydride compound and diamine compound is used to form the polyimide polymer The structures of the tetracarboxylic dianhydride component (a) and the diamine component (b) are different; (6) polyamide polymers, polyimide polymers, tetracarboxylic dianhydride compounds and diamines Compound, wherein at least one of a tetracarboxylic dianhydride compound and a diamine is combined with the tetracarboxylic dianhydride component (a) and the diamine component used to form a polyamic acid polymer or a polyimide polymer (b) have different structures; (7) two types of polyamide polymers, tetracarboxylic dianhydride compounds and diamine compounds with different structures; (8) two types of polyimide polymers with different structures , tetracarboxylic dianhydride compounds and diamine compounds; (9) two types of polyamide polymers and diamine compounds whose terminal groups are acid anhydride groups and have different structures; (10) two types of terminal groups are amine groups and have different structures Different polyamide polymers and tetracarboxylic dianhydride compounds; (11) Two types of polyamide polymers and diamine compounds whose terminal groups are acid anhydride groups and have different structures; (12) Two types of terminal groups It is an amine-based and structurally different polyimide polymer and a tetracarboxylic dianhydride compound.

Within the scope that does not affect the efficacy of the present invention, preferably, the aforementioned polyamic acid polymer, the aforementioned polyimide polymer and the aforementioned polyimide-based block copolymer can be terminals whose molecular weight has been adjusted first. Modified polymers. By using end-modified polymers, the coating performance of the liquid crystal alignment agent can be improved. The aforementioned terminal-modified polymer can be prepared by adding a monofunctional compound while the polyamide polymer is undergoing a polycondensation reaction. The monofunctional compound includes but is not limited to (1) monobasic acid anhydride, such as : Monobasic anhydrides 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; ( 2) Monoamine compounds, such as: aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine Monoamine compounds such as alkylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecanylamine, n-octadecylamine or n-eicosylamine; (3) Monoisocyanate compounds, such as monoisocyanate compounds such as phenyl isocyanate or naphthyl isocyanate.

The polystyrene-converted weight average molecular weight of the polymer (A) of the present invention measured by gel permeation chromatography is 10,000 to 90,000, preferably 12,000 to 75,000, and more preferably 15,000 to 60,000. Solvent(B)

The solvent used in the liquid crystal alignment agent of the present invention is not particularly limited, as long as it can dissolve polymer (A) and any other components without reacting with them. Preferably, it is the same as that used in the aforementioned synthetic polyamide. The solvent used may also be combined with a poor solvent used in the synthesis of the aforementioned polyamide.

Specific examples of the solvent (B) include, but are not limited to, N-methyl-2-pyrrolidone (NMP), 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 ether ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl 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 or N,N-dimethylformamide or N,N-dimethylacetamide (N,N-dimethyl acetamide), etc.

The aforementioned solvent (B) can be used alone or in combination of a plurality of solvents.

Based on the usage amount of polymer (A) being 100 parts by weight, the usage amount of solvent (B) is 800 to 4000 parts by weight, preferably 900 to 3500 parts by weight, and more preferably 1000 to 3000 parts by weight. . Additive(C)

Within the scope that does not affect the efficacy of the present invention, the liquid crystal alignment agent of the present invention may optionally include an additive (C), and the additive (C) may be an epoxy compound or a silane compound with a functional group, etc. The function of the additive (C) is to improve the adhesion between the liquid crystal alignment film and the surface of the substrate. Additive (C) can be used individually by 1 type or in mixture of multiple types.

The aforementioned epoxy compounds may include, but are not limited to, ethylene glycol diepoxypropyl ether, polyethylene glycol diepoxypropyl ether, propylene glycol diepoxypropyl ether, tripropylene glycol diepoxypropyl ether, and polypropylene glycol. Diglycidyl ether, neopentyl glycol dialpoxypropyl ether, 1,6-hexanediol dialpoxypropyl ether, glycerol dialpoxypropyl ether, 2,2-dibromoneopentyl ether Glycol diglycidyl ether, 1,3,5,6-tetraepoxypropyl-2,4-hexanediol, N,N,N',N'-tetraepoxypropyl-m-diol Toluenediamine, 1,3-bis(N,N-diepoxypropylaminomethyl)cyclohexane, N,N,N',N'-tetraepoxypropyl-4,4'-bis Aminodiphenylmethane, N,N-epoxypropyl-p-glycidoxyaniline, 3-(N-allyl-N-epoxypropyl)aminopropyltrimethoxysilane, 3-(N,N-diepoxypropyl)aminopropyltrimethoxysilane, etc.

Based on the usage amount of polymer (A) being 100 parts by weight, the usage amount of the epoxy compound is generally less than 40 parts by weight, 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-aminopropyltrimethoxysilane, Aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl Dimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane Silane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine Triamine, 10-trimethoxysilyl-1,4,7-triazodecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl- 3,6-Diazenonyl 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(ethylene oxide)-3-aminopropyltrimethoxysilane, N-bis(ethylene oxide)-3-aminopropyltriethoxysilane, etc.

Based on the usage amount of 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 100 parts by weight of the polymer (A), the additive (C) may be used in an amount of 0.5 to 50 parts by weight, and preferably 1 to 45 parts by weight. Preparation method of liquid crystal alignment agent

The preparation method of the liquid crystal alignment agent of the present invention is not particularly limited. A general mixing method can be used. For example, the tetracarboxylic dianhydride component (a) and the diamine component (b) are first mixed evenly to react to form a polymer. Object (A). Then, add solvent (B) and additive (C) to polymer (A) at a temperature of 0°C to 200°C, and continue stirring with a stirring device until dissolved. Preferably, polymer (A) and additive (C) are added to solvent (B) at a temperature of 20°C to 60°C. Method for forming liquid crystal alignment film

The liquid crystal alignment film of the present invention is a film obtained by coating the liquid crystal alignment agent formed above on a substrate, drying and baking.

The substrate coated with the liquid crystal alignment agent of the present invention is selected from transparent materials. The transparent materials include but are not limited to alkali-free glass, soda-lime glass, hard glass (Pyles glass), and quartz glass used in liquid crystal display devices. , polyethylene terephthalate, polybutylene terephthalate, polyether terephthalate, polycarbonate, etc. It is better to use ITO electrodes for liquid crystal driving that have been formed on the substrate to simplify the manufacturing process. Furthermore, for a reflective liquid crystal display with only one side substrate, the substrate can be made of opaque material such as silicon wafer. In this case, the electrode can be formed of a light-reflecting material such as aluminum. The coating method of the liquid crystal alignment agent of the present invention can be, for example, spin coating method, printing method, inkjet method, etc.

The liquid crystal alignment agent of the present invention can select any temperature and time to perform the drying and baking process after coating. Generally speaking, in order to fully remove the organic solvent contained, drying at 50°C to 120°C is required for 1 minute to 10 minutes. After that, bake at 150°C to 300°C for 5 minutes to 120 minutes. There is no special limit on the thickness of the coating film after baking, but a coating film that is too thin will cause the reliability of the LCD to deteriorate. Therefore, the above-mentioned coating film thickness is preferably 5 nm to 300 nm, and 10 nm to 200 nm. For better.

Although the liquid crystal alignment agent of the present invention can be subjected to conventional rubbing alignment treatment, the effect is better when using a photo alignment treatment method.

Specific examples of the photo-alignment treatment method include: irradiating the surface of the coating film with radiation polarized in a specific direction, and then performing a heat treatment at a temperature of 150°C to 250°C, as appropriate, to impart liquid crystal alignment ability to the coating film. . Among them, ultraviolet rays or visible light with a wavelength of 100 nm to 800 nm can be used as the above-mentioned radiation, and ultraviolet rays with a wavelength of 100 nm to 400 nm are preferred, and those with a wavelength of 200 nm to 400 nm are even more preferred. Furthermore, in order to improve the alignment of the liquid crystal, the coating substrate can be irradiated with radiation while heating the coating substrate at 50°C to 250°C. The irradiation dose of the aforementioned radiation is preferably 1 mJ/cm ² to 10,000 mJ/cm ² , and more preferably 100 mJ/cm ² to 5,000 mJ/cm ² . The liquid crystal alignment film prepared in the above manner can stably align liquid crystal molecules in a certain direction.

The liquid crystal alignment agent of the present invention is subjected to pre-baking treatment, post-baking treatment and photo-alignment treatment to form a liquid crystal alignment film, wherein the pre-tilt angle of the liquid crystal alignment film is 0° to 3°. Method for manufacturing liquid crystal display element

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

The manufacturing method of liquid crystal display elements is well known to those in the art, and therefore, it is only briefly described below.

1 , a preferred embodiment of the liquid crystal display device 100 of the present invention comprises a first unit 110 , a second unit 120 and a liquid crystal unit 130 , wherein the second unit 120 is spaced apart from the first unit 110 , and the liquid crystal unit 130 is disposed between the first unit 110 and the second unit 120 .

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

The second unit 120 includes a second substrate 122 and a second liquid crystal alignment film 126, where 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. The transparent materials include but are not limited to alkali-free glass, soda-lime glass, hard glass (Pyles glass), and quartz glass used in liquid crystal display devices. , polyethylene terephthalate, polybutylene terephthalate, polyether terephthalate, 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 respectively the above-mentioned liquid crystal alignment films, and their function is to form a pretilt angle for the liquid crystal unit 130, and the liquid crystal unit 130 can be driven by the parallel electric field generated by the electrode 114.

The liquid crystals used in the liquid crystal unit 130 can be used alone or in combination. The liquid crystals include, but are not limited to, diaminobenzene-based liquid crystals, pyridazine-based liquid crystals, Schiff base-based liquid crystals, and azo-based liquid crystals. (azoxy) liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, biphenyl (biphenyl) liquid crystal, phenylcyclohexane (phenylcyclohexane) liquid crystal, ester (ester) liquid crystal, terphenyl (terphenyl) , biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, etc., and based on demand Then add cholesterol-type liquid crystals such as cholesteryl chloride, cholesteryl nonanoate, cholesteryl carbonate, etc., or use the trade names "C-15" and "CB-15" chiral agent (manufactured by Merck & Co., Ltd.), or ferroelectric liquid crystals such as p-decoxybenzylidene-p-amino-2-methylbutylcinnamate.

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

The following examples are used to illustrate the application of the present invention, but they are not intended to limit the present invention. Anyone familiar with this art can make various changes and modifications without departing from the spirit and scope of the present invention.

Preparation Example 1

Please refer to process (1), add 96.1 grams (0.3 mol) of the diamine compound (da-1-1) shown in formula (I-1-A-1) and 600g of THF, and in a water bath, 65.4g (0.3 mol) of di-tert-butyl dicarbonate (Boc ₂ O) was added dropwise and stirred at room temperature. After the reaction is completed, the reaction solution is concentrated, and the resulting residue is separated by silica gel column chromatography (ethyl acetate: n-hexane = 1:1 volume ratio) to obtain 50.4g of formula (I-1-A-2 ) the compound shown.

In a 3L four-necked flask, add 50.4g (0.12 mol) of the compound represented by formula (I-1-A-2) and 480g of NMP. In a water bath, add 13.4g (0.06 mol) of NMP. After preparing the compound represented by formula (1-1), it was stirred at room temperature for 6 hours. Next, 28.4 g (0.36 mol) of pyridine and 18.4 g (0.18 mol) of acetic anhydride (Ac ₂ O) were added to the reaction solution, and the mixture was stirred at 60°C. After the reaction is completed, 3 L of pure water is injected into the reaction system, and the precipitate is filtered out. 400 mL of MeOH was added to the obtained crude product, and repulping was performed at room temperature to obtain 44.2 g of the compound represented by formula (I-1-A-3).

Add 44.2g (0.043 mol) of the compound represented by formula (I-1-A-3) and 640g of CH ₂ Cl ₂ into a 3L four-necked flask. In a water bath, add 43.9g (0.43 mol) dropwise. After adding trifluoroacetic acid, stir at room temperature. After the reaction is completed, the reaction solution is concentrated, 2 L of pure water is added to the obtained crude product, and the mixture is neutralized with triethylamine. The precipitate was filtered, 100 g of MeOH was added to the obtained crude product, and reslurried and washed at room temperature to obtain 27.7 g of the diamine compound (b-1) represented by formula (I-1-A). -1). Preparation Examples 2 to 10

Preparation Examples 2 to 10 sequentially prepare diamine compounds (b-1-2) to (b-1-10) represented by formulas (I-2-A) to (I-10-A). Preparation Examples 2 to 10 use the same preparation method as Preparation Example 1, except that the types of reactants are changed in Preparation Examples 2 to 10. The formulas are as shown in Table 1 and will not be described again here. Preparation of polymer (A-1-1) Synthesis example A-1-1

Set up a nitrogen inlet, stirrer, condenser tube and thermometer on a four-necked conical flask with a volume of 500 ml, and introduce nitrogen gas. Then, 1.24 g (0.0015 mol) of the diamine compound (b-1-1) represented by the formula (I-1-A) and 0.235 g (0.0005 mol) of the diamine compound (b-1-1) represented by the formula (III-3) were added. Shown are diamine compound (b-2-1), 5.19 grams (0.048 mol) of p-diamine benzene (b-3-1) and 80 grams of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) , and stir at room temperature until dissolved. Next, 11.2 g (0.05 mol) of compound (a-1-1) represented by formula (1-1) and 20 g of NMP were added, and the mixture was reacted at room temperature for 2 hours. After the reaction is completed, pour the reaction solution into 1500 ml of water to precipitate the polymer, filter the obtained polymer, and repeat the steps of washing and filtering with methanol three times. Then, the product is placed in a vacuum oven and dried at a temperature of 60°C to prepare the polymer (A-1-1) of Synthesis Example A-1-1. The formula is shown in Table 2. Synthesis Example A-1-2 to Synthesis Example A-1-15 and Comparative Synthesis Example A'-1-1 to Comparative Synthesis Example A'-1-2

Synthesis Examples A-1-2 to A-1-15 and Comparative Synthesis Examples A'-1-1 to A'-1-2 use the same polymer (A-1-1) as in Synthesis Example A-1-1. The preparation method is the same, except that the types and uses of raw materials in the polymer are changed in Synthesis Examples A-1-2 to A-1-15 and Comparative Synthesis Examples A'-1-1 to A'-1-2. The formula is shown in Table 2 and will not be described again here. Preparation of polymer (A-2) Synthesis example A-2-1

Set up a nitrogen inlet, stirrer, condenser tube and thermometer on a four-necked conical flask with a volume of 500 ml, and introduce nitrogen gas. Then, 1.24 g (0.0015 mol) of the diamine compound (b-1-1) represented by the formula (I-1-A) and 0.235 g (0.0005 mol) of the diamine compound (b-1-1) represented by the formula (III-3) were added. Shown are diamine compound (b-2-1), 5.19 grams (0.048 mol) of p-diamine benzene (b-3-1) and 80 grams of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) , and stir at room temperature until dissolved. Next, 11.2 g (0.05 mol) of compound (a-1-1) represented by formula (1-1) and 20 g of NMP were added. After reacting at room temperature for 6 hours, 97 grams of NMP, 2.55 grams of acetic anhydride and 19.75 grams of pyridine were added, the temperature was raised to 60°C, and stirring was continued for 2 hours to carry out the imidization reaction. After the reaction is completed, pour the reaction solution into 1500 ml of water to precipitate the polymer. Then, filter the obtained polymer, repeat washing and filtering with methanol three times, place it in a vacuum oven, and dry it at a temperature of 60°C to obtain polymer (A-2-1). The formula is as shown in Table 2 shown. Synthesis Examples A-2-2 to A-2-5 and Comparative Synthesis Examples A'-2-1 to A'-2-2

Synthesis Examples A-2-2 to Synthesis Examples A-2-5 and Comparative Synthesis Examples A'-2-1 to A'-2-2 use the same polymer as Synthesis Example A-2-1 (A-2-1 ) is the same preparation method, except that the raw materials in the polymer are changed in Synthesis Examples A-2-2 to A-2-5 and Comparative Synthesis Examples A'-2-1 to A'-2-2. The type and usage amount, and its formula are shown in Table 2, which will not be described again here. Preparation of liquid crystal alignment agents, liquid crystal alignment films and liquid crystal display elements Example 1

Weigh 100 parts by weight of the polymer (A-1-1) prepared in Synthesis Example A-1-1 and 800 parts by weight of NMP (B-1), and stir and mix at room temperature to obtain the product. Liquid crystal alignment agent of Example 1.

The liquid crystal alignment agent prepared above is spin-coated on a glass substrate, and a pixel electrode is formed on the glass substrate, wherein the pixel electrode has a pair of ITO electrodes (electrode width: 10 μm, electrode spacing: 10 μm, Electrode height: 50 nm) for IPS driving electrodes, the pair of ITO electrodes each have a comb-tooth shape, and the comb-tooth portions of each other are arranged in a manner that they are separated and engaged. Then, the glass substrate coated with the liquid crystal alignment agent was dried on a hot plate at 80°C for 5 minutes, and then baked in a hot air circulation oven at 250°C for 60 minutes to form a coating film with a thickness of 100 nm.

Through a polarizing plate, the coating surface is irradiated with ultraviolet light with a wavelength of 254 nm to prepare a substrate with a liquid crystal alignment film. Next, in the same manner, a coating film was formed on the counter substrate, which was a glass substrate without an electrode formed but with a columnar spacer having a height of 4 μm, and an alignment process was performed.

The above two substrates are a set. Print sealant on one of them, and bond the other with the liquid crystal alignment film facing the alignment direction of 0°, and then harden the sealant to make an empty unit cell. Liquid crystal MLC-2041 (manufactured by Merck) was injected into this empty unit cell using a reduced pressure injection method, and the injection port was sealed. This was the liquid crystal display element of Example 1. The liquid crystal display element of Example 1 was evaluated in the following evaluation method. The formula and results are shown in Table 3. The method for detecting the degree of flicker immediately after driving will be described later. Example 2 to Example 20 and Comparative Example 1 to Comparative Example 4

Examples 2 to 20 and Comparative Examples 1 to 4 use the same preparation method as the liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element of Example 1. The difference is that Examples 2 to 20 and Comparative Examples 1 to 4 use the same preparation method. By changing the type and usage amount of raw materials in the liquid crystal alignment agent, the formula and evaluation results are shown in Table 3 and Table 4 respectively, which will not be described again here. Evaluation method Immediate flicker level after driving

The prepared liquid crystal display element is placed between two polarizing plates whose polarization axes are arranged in a vertically crossing manner. The LED backlight is lit without applying voltage, and the arrangement angle of the liquid crystal display element is adjusted to increase the brightness of the transmitted light. reach the minimum state. Next, an AC voltage with a frequency of 30 Hz was applied to the liquid crystal display element, and the V-T curve (voltage-transmittance curve) was measured at the same time, and the AC voltage with a relative transmittance of 23% was calculated as the driving voltage.

The method of measuring the flicker after driving is to turn off the lit LED backlight under the condition that the temperature of the liquid crystal display element is 23°C, and then light it up again after leaving it in shade for 72 hours, and then turn on the backlight. At the same time, an AC voltage of 30 Hz with a relative transmittance of 23% was applied to drive the liquid crystal display element for 60 minutes, and the amplitude of the flicker was tracked. The amplitude of the flicker is measured using a data acquisition/data recording switching device 34970A (manufactured by Agilent Technologies) connected to a photodiode and an IV conversion amplifier to read the brightness value passing through two polarizing plates and the liquid crystal display element between them. . The flicker degree (FL) is calculated according to the following formula (VII). The lower the flicker degree, the better the quality of the liquid crystal display element produced by the liquid crystal alignment agent. (V)

In formula (V), z is the brightness value read when using the above-mentioned device 34970A and driving it with an AC voltage of 30 Hz with a relative transmittance of 23%. ※：FL＜2% ◎：3%＞FL≧2% ○：4%＞FL≧3% △：5%＞FL≧4% ╳: FL≧5%.

According to the results in Table 3 and Table 4, it can be seen that if the diamine component (b) of the liquid crystal alignment agent of the present invention does not include the diamine compound (b-1) shown in formula (I), the liquid crystal display element formed The flickering level immediately after driving is not good.

If in formula (I), one of X ₁ and X ₂ and one of X ₃ and X ₄ have a structure shown in formula (II-1) that satisfies the condition that m is 1, and X The other one of ₁ and X ₂ and the other one of X _{3 and} With the structure shown in (II-6), the degree of flickering of the formed liquid crystal display element immediately after driving can be further reduced.

In addition, when the diamine component (b) of the liquid crystal alignment agent of the present invention includes the diamine compound (b-2) shown in formula (III), the degree of flickering of the formed liquid crystal display element immediately after driving can be further lowered.

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 to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended patent application scope.

Table 1

Table 2

table 3

Table 4

100:Liquid crystal display element 110:Unit 1 112: First substrate 114: First conductive film 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 following description together with the corresponding drawings. It must be emphasized that various features are not drawn to scale and are for illustration purposes only. The relevant diagram content is explained as follows: [Fig. 1] is a schematic structural diagram of a liquid crystal display element according to an embodiment of the present invention.

100:Liquid crystal display element

110:Unit 1

112: First substrate

114: First conductive film

116:The first liquid crystal alignment film

120:Unit 2

122:Second substrate

126: Second liquid crystal alignment film

130:LCD unit

Claims (10)

A liquid crystal alignment agent, including: a polymer (A), and the polymer (A) is prepared by reacting a tetracarboxylic dianhydride component (a) and a diamine component (b), wherein the diamine component Part (b) contains diamine compound (b-1) represented by the following formula (I):

In the formula (I), Z ₁ to Z ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. Alkynyl group, a monovalent organic group containing fluorine atoms and having a carbon number of 1 to 6, or a phenyl group containing a fluorine atom and having a carbon number of 6, Z ₁ to Z ₄ may be the same or different, and Z ₁ , Z ₂ , at least one of Z ₃ and Z ₄ is not a hydrogen atom; Y ₁ to Y ₄ each independently represents a single bond, -O-, -S-, -NZ ₅ -, ester group, amide group, thioester group , urea group, carbonate group or carbamate group, where Z ₅ represents a hydrogen atom or a methyl group, Y ₁ to Y ₄ can be the same or different; A ₁ and A ₂ represent carbon atoms with a carbon number of 2 to 20. Alkylene group, _wherein A ₁ and A ₂ may be the same or different; X ₁ to Groups where X ₁ and X ₂ are not of the same structure, and X ₃ and X ₄ are not of the same structure:

In the formula (II-1), Z ₆ represents a substituted or unsubstituted divalent cyclic group, and the divalent cyclic group is selected from the following formula (II-1-1) to formula ( II-1-11), the hydrogen atom on the bivalent cyclic group can be an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a fluorine atom and a carbon Substituted by an alkyl group with a number of 1 to 3 or an alkoxy group containing a fluorine atom and having a carbon number of 1 to 3; m represents 1 to 5;

In the formula (II-1-11), R ₁₁ represents a hydrogen atom, methyl, hydroxyl or methoxy group; and in the formula (II-2), Z ₇ represents an alkane with a carbon number of 1 to 5. base; and a solvent (B). The liquid crystal alignment agent as described in claim 1, wherein one of X ₁ and X ₂ and one of X ₃ and X ₄ respectively represent the structure shown in the formula (II-1), and m is 1 , and the other one of X ₁ and X ₂ and the other one of X ₃ and X ₄ respectively represent the structures shown in the formula (II-1) to the formula (II-6), and m represents 2 to 5. The liquid crystal alignment agent according to claim 1, wherein the diamine component (b) further includes a diamine compound (b-2) represented by the following formula (III):

In the formula (III), Z ₈ and Z ₁₄ each independently represent a single bond, -CH ₂ - or -CH ₂ CH ₂ -; Z ₁₀ and Z ₁₂ each independently represent -CH ₂ - or -CH ₂ CH ₂ -; Z ₁₁ represents an alkylene group with a carbon number of 1 to 6 or a cyclohexylene group with a carbon number of 6; Z ₉ and Z ₁₃ each independently represent a single bond, -O-, -NH-, -N (CH ₃ )-, -C(=O)-, -C(=O)O-, -C(=O)NH-, -C(=O)N(CH ₃ )-, -OC(=O )-, -NHC(=O)- or -N(CH ₃ )C(=O)-; Z ₁₅ represents a linear hydrocarbon group with a carbon number of 1 to 20, a branched chain hydrocarbon group with a carbon number of 3 to 20 Or a cyclic hydrocarbon group having a carbon number of 3 to 20; and n represents 0 or 1. The liquid crystal alignment agent as described in claim 3, wherein Z ₉ and Z ₁₃ each independently represent a single bond or -O-. The liquid crystal alignment agent as described in claim 4, wherein n is 0. The liquid crystal alignment agent as described in claim 1, wherein the total usage amount of the diamine component (b) is 100 moles, and the usage amount of the diamine compound (b-1) is 3 to 30 moles. . The liquid crystal alignment agent as described in claim 3, wherein the total usage amount of the diamine component (b) is 100 moles, and the usage amount of the diamine compound (b-2) is 1 to 10 moles. . The liquid crystal alignment agent as described in claim 1, wherein the total usage amount of the polymer (A) is 100 parts by weight, and the usage amount of the solvent (B) is 800 to 4000 parts by weight. A liquid crystal alignment film is formed by using the liquid crystal alignment agent described in any one of claims 1 to 8. A liquid crystal display element including the liquid crystal alignment film described in claim 9.