TW201309751A - Photoactive crosslinking compound, method for preparing the same, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device - Google Patents

Abstract

The present invention relates to a photoactive crosslinker compound, to a method for preparing same, to a liquid crystal aligning agent, to a liquid crystal aligning film, and to a liquid crystal display device. More particularly, the present invention relates to the photoactive crosslinker compound having a novel structure, to the method for preparing same, to the liquid crystal aligning agent, to the liquid crystal aligning film, and to the liquid crystal display device. According to the present invention, the liquid crystal aligning agent has high vertical alignment performance, good storage stability, superior transparency, and excellent liquid crystal aligning properties, printability, and electrical characteristics. Further, the stability of a pretilt angle and strength of the film can be improved, and a pretilt of a liquid crystal can be formed by UV exposure alone.

Description

Photoactive crosslinking compound, preparation method thereof, liquid crystal alignment agent, liquid crystal alignment Film, and liquid crystal display device

The present invention relates to a photoactive crosslinking compound, a method for producing the same, a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device. More specifically, it relates to a photoactive crosslinking compound having a novel structure, a method for producing the same, a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device.

The present application claims priority to and the benefit of the Korean Patent Application No. 10-2011-0061213, filed on Jun.

In the structural material of the liquid crystal display, the liquid crystal alignment film is in contact with the liquid crystal molecules, thereby uniformly aligning the liquid crystal molecules. The liquid crystal alignment film is the core material for driving the liquid crystal, so that the liquid crystal is uniformly aligned toward one side, so that the liquid crystal can perform the switching function as the polarized light well, and the liquid crystal alignment characteristics of the liquid crystal alignment film and the electrical characteristics of the film determine the liquid crystal display. Display quality.

Representative methods for forming a liquid crystal alignment film include an oblique deposition method of an inorganic substance, a Langmuir-Blodgett (LB) method, a polymer stretching method, a rubbing method, etc., as a new alignment method. There are photo-alignment method and ion beam irradiation method. One of the most commonly used methods is the rubbing method of rubbing the surface of the substrate with a cloth. The rubbing method refers to a method in which paper is rubbed in a predetermined direction to rub the glass substrate so that the long axes of the liquid crystal molecules are aligned and aligned along the rubbing direction thereof. Because the friction method is easy to handle, it is suitable for mass production, and has an orientation stabilization and pretilt angle control. The advantage is therefore the most used alignment method in the industry.

As the material of the alignment film, the most used polyimine which has a low dielectric constant, high thermal stability, excellent mechanical strength, and excellent processability. However, the use of polyimine as an alignment film material has the following problems or disadvantages. First, since static electricity may damage thin film transistor (TFT) devices, production machines generally have countermeasures against electrostatic problems. However, the friction method has the disadvantage of not providing a complete solution to the static electricity generated during the alignment process. Second, dust may be generated during the alignment by the rubbing method, so a subsequent cleaning process is required, which may cause a problem of reduced efficiency during the process. Third, the flat portion having the alignment layer of the step portion is different from the friction condition of the step portion, so that the possibility of occurrence of alignment fixing force and uneven inclination is high. Fourth, since the process is only rubbed in one direction, the manufacturing process of the alignment layer having the separated alignment pixels becomes complicated. Moreover, in order to be able to uniformly rub a large substrate, special equipment is also required.

In order to overcome the shortcomings of the prior art, a light alignment technique is being developed in which a liquid crystal alignment film can be prepared by irradiating only a polarized ultraviolet (UV) light onto a polymer film in a frictionless state. The principle of light alignment technology is to produce optical anisotropy on the film by causing a photoreaction. Therefore, in order to utilize the liquid crystal light alignment control technology, it is necessary to use light having a linear polarization directivity, and a photoreaction process of a polymer film such as photoisomerization, photopolymerization or photolysis is required, and the polarization direction of the irradiated light is required. It is possible to control a plurality of conditions such as the direction of liquid crystal molecules.

Generally in vertical alignment liquid crystal mode (Vertical Alignment Liquid In Crystal Mode, in order to minimize the change in brightness caused by the angle of view, multi-domain should be formed. Therefore, multi-alignment processing is required, but the rubbing alignment method cannot adjust the alignment range in micrometer units, but must be utilized. It is solved by forming an electrode pattern on the upper and lower substrates or forming protrusions. However, the above two methods require an additional process, and there are disadvantages such as a response speed or an electro-optical characteristic problem of initial light leakage.

Therefore, there is a need for a solution that can solve the problems of poor economics of the existing optical pattern forming process, insufficient environmental affinity, poor stability, and reduced optical performance of the prepared optical pattern.

In order to solve the problems existing in the prior art liquid crystal alignment method, the object of the present invention is to provide a novel photoactive crosslinking compound for preparing a liquid crystal alignment agent, which is a method for aligning liquid crystal molecules in a frictionless state. That is, the photo-alignment technique has excellent thermal stability after it forms an alignment film, and can achieve high alignment and stability after irradiation of ultraviolet rays.

Further, it is an object of the present invention to provide a process for producing the photoactive crosslinking compound.

Further, it is an object of the present invention to provide a liquid crystal alignment agent comprising the photoactive crosslinking compound, and polylysine or polyimine.

Furthermore, it is an object of the present invention to provide a liquid crystal alignment film formed of the liquid crystal alignment agent.

Furthermore, it is an object of the present invention to provide a liquid crystal display device having the liquid crystal alignment film.

In order to achieve the above object, the present invention provides a photoactive crosslinking compound represented by the following Chemical Formula I.

In the chemical formula I, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20.

Further, the present invention provides a photoactive activity represented by the following Chemical Formula II Cross-linking compounds.

In the chemical formula II, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20.

Further, the present invention provides a liquid crystal alignment agent comprising the photoactive crosslinking compound, and polyamic acid or polyimine.

Further, the present invention provides a liquid crystal alignment film formed of the liquid crystal alignment agent.

Further, the present invention provides a liquid crystal display device having the liquid crystal alignment film.

In another aspect, the present invention provides a process for producing a photoactive crosslinking compound represented by the following Chemical Formula 20, which comprises the step of reacting a compound represented by the following Chemical Formula 19 with a compound represented by the following Chemical Formula 5.

In the chemical formulas 5, 19 and 20, R ₁ to R ₈ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, And any one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20.

Furthermore, the present invention provides a process for producing a photoactive crosslinking compound represented by the following Chemical Formula 40, which comprises the step of reacting a compound represented by the following Chemical Formula 39 with a compound represented by the following Chemical Formula 28.

In the chemical formulas 28, 39 and 40, R ₁ to R ₄ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, And any one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20.

Since the present invention utilizes a light alignment technique for aligning liquid crystal molecules in a frictionless state, it is possible to ensure the safety and economy of the process, and to provide an environmentally friendly process.

The liquid crystal alignment agent containing the photoactive crosslinking compound of the present invention can further improve the stability of the pretilt angle of the liquid crystal alignment film and the film strength, and can realize the pretilt of the liquid crystal only by UV exposure, thereby providing simplicity Process to reduce production costs and increase productivity.

Further, the present invention can provide a liquid crystal alignment agent which has high vertical alignment performance, good storage stability, excellent transparency, and excellent liquid crystal alignment, printability, and electrical characteristics.

[Simple description of the map]

Fig. 1 is a view showing a liquid crystal alignment photograph of a liquid crystal display device prepared in Example 3 of the present invention.

2 shows a liquid crystal alignment photograph of the liquid crystal display device prepared in Comparative Example 1.

The liquid crystal alignment agent prepared from the photoactive crosslinking compound of the present invention can prepare a liquid crystal alignment film by a light alignment technique of irradiating ultraviolet light (UV) on a polymer film without performing a rubbing treatment.

The principle of light alignment technology is to produce optical anisotropy on the film by causing a photoreaction. Therefore, in order to utilize the liquid crystal light alignment control technology, it is necessary to use light having a linear polarization directivity, and a photoreaction process of a polymer film such as photoisomerization, photopolymerization or photolysis is required, and polarization of the irradiated light is required. The direction can control a plurality of conditions such as the direction of the liquid crystal molecules.

The photoisomerization reaction has a disadvantage that it is affected by the reverse reaction, and there are disadvantages such as contamination of the liquid crystal layer by the decomposition product in the photolysis reaction. In the photopolymerization reaction, a poly(vinyl cinnamate) polymer was first explored. However, since the wavelength of the ultraviolet ray used is short, it is difficult to mass-produce it using a general-purpose large-scale exposure apparatus. problem.

Polyimide resin commonly used as a photo-aligning agent means After the polycondensation of the aromatic tetracarboxylic acid or its derivative with an aromatic diamine or an aromatic diisocyanate, the high heat resistant resin obtained by oxime imidization is further subjected.

Polyimine resins can have a variety of molecular structures depending on the type of monomer used. Generally, as the aromatic tetracarboxylic acid component, pyromellitic dianhydride (PMDA) or biphenyltetracarboxylic dianhydride (BPDA) is used; as the aromatic diamine component, p-phenylenediamine (p-) is used. PDA), m-phenylenediamine (m-PDA), 4,4'-diaminodiphenyl ether (ODA), 4,4'-diaminodiphenylmethane (MDA), 2,2'-double 2,2'-bisamino phenyl hexafluoropropane (HFDA), m-bisaminophenoxydiphenyl hydrazine (m-BAPS), p-diaminophenoxydiphenyl hydrazine (p- BAPS), 1,4-bis(4-aminophenoxy)benzene (TPE-Q), 1,3-bis(4-aminophenoxy)benzene (TPE-R), 2,2'- [4-(4-Diaminophenoxy)phenyl]propane (BAPP), and 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (HFBAPP), etc. .

Generally, in the Vertical Alignment Liquid Crystal Mode, in order to minimize the change in luminance caused by the viewing angle, a multi-domain should be formed, so that a multi-alignment processing method is required, but the friction alignment method cannot The alignment range is adjusted in micrometer units, and must be solved by forming an electrode pattern on the upper and lower substrates or forming protrusions. However, the above two methods require an additional process, and there are disadvantages such as a response speed or an electro-optic characteristic problem of initial light leakage.

An object of the present invention is to provide a photoactive crosslinking compound and a liquid crystal alignment agent comprising the same, which can realize alignment of liquid crystal molecules in a liquid crystal display device by using such a photoalignment technique, whereby after forming an alignment film, only Pretilt can be achieved with UV exposure.

The specific terms used in the specification are used to describe the invention to those skilled in the art, and are not intended to limit the scope of the invention or the scope of the invention described in the claims.

Hereinafter, the photoactive crosslinking compound of the present invention, a method for producing the same, a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device will be described in further detail with reference to examples. However, the various embodiments of the invention may be modified into other various forms, and the scope of the invention should not be construed as being limited to the embodiments described below. The various embodiments of the present invention are intended to provide a more complete description of the invention.

Photoactive crosslinking compound and preparation method thereof

According to an aspect of the invention, the photoactive crosslinking compound of the invention can be represented by the following chemical formula I.

In the chemical formula I, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20.

According to an embodiment of the present invention, in the formula I, R1 to R8 may be H, and n may be an integer of 1 to 5.

According to an embodiment of the present invention, the compound of the formula I may be, for example, a compound represented by the following Chemical Formula 20, Chemical Formula 22 or Chemical Formula 24.

In the formula 20, R ₁ to R ₈ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; n is an integer of 1 to 20.

According to another aspect of the present invention, there is provided a process for producing a photoactive crosslinking compound represented by the Chemical Formula 20.

The method for producing a photoactive crosslinking compound represented by the chemical formula 20 includes a step of reacting a compound represented by the following Chemical Formula 19 with a compound represented by the following Chemical Formula 5.

In the chemical formulas 5, 19 and 20, R ₁ to R ₈ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, and an alkyl group having 1 to 10 carbon atoms. And one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20.

More specifically, the preparation method of the photoactive crosslinking compound represented by the Chemical Formula 20 can be produced by gradually performing the following Reaction Formulas 1, 2, 3, 4 and 5, however, the present invention is not limited thereto.

In the reaction formulae 1 to 5, R ₁ to R ₈ and n are the same as those defined in the chemical formula I.

The starting compound, the intermediate compound, and the resulting compound used in the reaction formulae 1 to 5 can be represented by the following Chemical Formulas 1 to 24.

In the chemical formulae 1 to 24, R ₁ to R ₈ and n are the same as those defined in the chemical formula I.

Further, in the above Reaction Formulas 1 to 5, the compounds of Chemical Formulas 21 and 23 can be used instead of the compound of Chemical Formula 6, and the compounds of Chemical Formula 22 and Chemical Formula 24 can be separately produced by a method similar to the Reaction Formulas 1 to 5.

According to another aspect of the present invention, the photoactive crosslinking compound of the present invention can be represented by the following Chemical Formula II.

In the chemical formula II, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20.

According to an embodiment of the present invention, in the formula II, R ₁ to R ₈ are H, and n may be an integer of 1 to 5.

According to an embodiment of the present invention, the compound of the formula II can be represented by the following chemical formula 40.

In the formula 40, R ₁ to R ₄ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; n is an integer of 1 to 20.

According to another aspect of the present invention, there is provided a process for producing a photoactive crosslinking compound represented by the Chemical Formula 40.

The method for producing a photoactive crosslinking compound represented by the chemical formula 40 includes a step of reacting a compound represented by the following Chemical Formula 39 with a compound represented by the following Chemical Formula 28.

In the chemical formulas 28, 39 and 40, R ₁ to R ₄ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, and an alkyl group having 1 to 10 carbon atoms. And one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20.

More specifically, the method for producing the photoactive crosslinking compound represented by the chemical formula 40 can be produced by performing the following Reaction Formulas 6 and 7, but the present invention is not limited thereto.

In the reaction formulas 6 and 7, R ₁ to R ₄ and n are the same as those defined in the chemical formula II.

The starting compound, the intermediate compound, and the resulting compound used in the reaction formulas 6 and 7 can be represented by the following Chemical Formulas 25 to 40.

In the chemical formulae 25 to 40, R ₁ to R ₄ and n are the same as those defined in the chemical formula II.

The above novel photoactive crosslinking compound of the present invention can further improve the stability of the pretilt angle of the liquid crystal alignment film and the film strength. More specifically, When a liquid crystal alignment agent is prepared by adding the photoactive crosslinking compound of the present invention to polyacrylic acid or polyimine, the stability of the pretilt angle of the liquid crystal alignment film and the film strength can be further improved.

Liquid crystal alignment agent

The present invention provides a liquid crystal alignment agent comprising the above photoactive crosslinking compound; and polylysine or polyimine.

The polyperuric acid is obtained by allowing a diamine compound to react with a tetracarboxylic dianhydride, which is obtained by dehydrating a ring-shaped polyamic acid to carry out oxime imidization.

According to an embodiment of the present invention, the liquid crystal alignment agent may include 0.1 to 40 parts by weight of the photoactive crosslinking compound, and may preferably include 0.1 to 100 parts by weight of the polyamic acid or polyimine. 30 parts by weight of the photoactive crosslinking compound.

In the present invention, the diamine compound which can be used for obtaining polylysine is, for example, selected from p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4. '-Diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl hydrazine, 3,3'-dimethyl-4,4'-di Aminobiphenyl, 4,4'-diaminophenylbenzophenone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4, 4'-Diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 6-amino-1-(4'-amino group Benzene)-1,3,3-trimethylindan, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminodiphenyl Methyl ketone, 4,4'-diaminobenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-amine Phenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]indole, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9, 9-bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminopurine, 9,9-bis(4-aminophenyl)anthracene, 4,4'-methylene-bis ( 2-chloroaniline), 2,2',5,5'-tetrachloro-4,4' -diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4' -diaminobiphenyl, 1,4,4'-(p-phenylene isopropylidene)diphenylamine, 4,4'-(m-phenylene isopropylidene)diphenylamine, 2,2 '-Bis[4-(4-Amino-2-trifluoromethylphenoxy)benzene]hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl) Benzene, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, bis(4-aminophenyl)benzidine, 1-(4-amino group Benzene)-1,3,3-trimethyl-1H-indan-5-amine, 1,1-m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine , hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 1,4-cyclohexanediamine, isophoronediamine, tetrahydrobicyclopentadienyldiamine, tricyclic [6.2.1.0 ^2,7 ]-Decacenary dimethyldiamine, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane, etc. Or an alicyclic diamine; and 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamine Base-2,3-cyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-three Pyrazine, 1,4-bis(3-aminopropyl)piperazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6 -Methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s -triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-benzene Thiazole, 2,6-diaminoguanidine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9 -6,9-diamino-2-ethoxy-acridine Lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diamine Piperazine, 3,6-diamino acridine, bis(4-aminophenyl)aniline, 1-(3,5-diaminophenyl)-3-mercaptosuccinimide, 1- a group consisting of (3,5-diaminophenyl)-3-octylsuccinimide, etc., having a primary amine group in the molecule and having a nitrogen atom in addition to the primary amine group One or more kinds of diamine compounds.

The tetracarboxylic dianhydride used for synthesizing the polyamic acid or the polyimine in the liquid crystal alignment agent of the present invention may, for example, be an alicyclic tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride or an aromatic tetracarboxylic acid. Acid dianhydride.

Specific examples of the alicyclic tetracarboxylic dianhydride may be 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutane IV. Carboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutane tetracarboxylate Acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcyclooctane-1 , 5-diene-1,2,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentaneacetic acid dianhydride, 5-(2,5-dioxotetrahydro-3 -furyl)-3-methyl-3-cycloethylene-1,2-dicarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornene-2:3,5:6-di Anhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)- Naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5(tetrahydro-2,5-dioxo -3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5 (tetrahydrogen) -2,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7- Methyl-5 (tetrahydro-2,5-dioxo -3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl-5(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan- 1,3-diketone, 1,3,3a,4,5,9b-hexahydro-8-methyl-5(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1, 2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-ethyl-5(tetrahydro-2,5-dioxo-3-furanyl )-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5(tetrahydro-2 ,5-dioxo-3-furanyl)-naphtho[1,2-c]-furan-1,3-dione, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3 -cycloethylene-1,2-dicarboxylic anhydride, bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo[3 2,1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione) and the like.

Specific examples of the aliphatic tetracarboxylic dianhydride may be butane tetracarboxylic dianhydride or the like. Specific examples of the aromatic tetracarboxylic dianhydride may be pyromellitic dianhydride, 4,4'-biphthalic dianhydride, 3,3', 4,4. '-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-bisphenylindole tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3, 6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylnonane tetracarboxylic acid Anhydride, 3,3',4,4'-tetraphenylnonanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxybenzene Oxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl phthalic anhydride, 4,4'-bis(3,4-dicarboxyphenoxy) Diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, double (phthalic acid) phenyl phosphine oxide, bis-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic acid)-4,4'- Diphenyl Dianhydride, Ethylene glycol-bis(dehydrated trimellitate), propylene glycol-bis(hydrogen trimellitate), 1,4-butanediol-bis(hydrogen trimellitate), 1,6-hexane Alcohol-bis(hydrogen trimellitate), 1,8-octanediol-bis(anhydrotrimellitic acid ester), 2,2-bis(4-hydroxyphenyl)propane-bis(dehydrated trimellitate) Acid ester) and the like.

Polylysine can be obtained by reacting the diamine compound with the tetracarboxylic dianhydride.

The use ratio of the tetracarboxylic dianhydride and the diamine compound used for the synthesis reaction of the polyamic acid is as follows: an acid anhydride in the tetracarboxylic dianhydride relative to 1 equivalent of an amine group in the diamine compound It is preferably about 0.2 to 2 equivalents, more preferably about 0.7 to 1.2 equivalents.

The synthesis reaction of polylysine is carried out in an organic solvent at a temperature of from -20 ° C to 150 ° C, preferably from 0 ° C to 100 ° C, for a reaction time of from 1 hour to 72 hours, preferably 3 hours to 48 hours.

In this case, the organic solvent to be used is not particularly limited as long as it is capable of dissolving the produced polyamic acid, and may be, for example, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N. , N-dimethylformamide, 3-butoxy-N,N-dimethylpropane decylamine, 3-methoxy-N,N-dimethylpropane decylamine, 3-hexyloxy- a guanamine compound such as N,N-dimethylpropane decylamine; an aprotic compound such as dimethyl hydrazine, γ-butyrolactone, tetramethyl urea, hexamethylphosphonium triamine; and m-cresol, a phenol compound such as xylenol, phenol or phenol halide.

On the other hand, the organic solvent can simultaneously use a poor solvent of a polylysine such as an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon or a hydrocarbon in the range of the polyamic acid formed without precipitation. Solvent). This kind of not Specific examples of the good solvent may be methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, lactic acid Ester, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, Methyl methoxy propanoate, ethyl ethoxy propionate Ethylene propanoate), diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene Alcohol-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, two Glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, O-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamyl propionate, isoamyl butyrate, diisoamyl ether, and the like. Thus, a reaction solution which reacts by dissolving polylysine can be obtained. Thereafter, the reaction solution is added to a large amount of poor solvent to obtain a precipitate, and the precipitate is obtained by drying the precipitate under reduced pressure or by vacuum distillation with an evaporator and removing the reaction solution to obtain polylysine. Alternatively, the polylysine may be redissolved in an organic solvent, and then the poly-proline may be purified by performing one or more processes of precipitating with a poor solvent or by a process of decompressing, distilling and removing with an evaporator.

Polyimine is obtained by dehydrating the obtained polylysine by ring closure to carry out oxime imidization.

The method for performing the dehydration ring closure of the polyamic acid is preferably (i) a method of permeating the poly-proline acid, or (ii) dissolving the poly-proline in an organic solvent, and adding a dehydrating agent to the solution. After the catalyst for dehydration ring closure, It is carried out according to the method of heating required. The reaction temperature in the method of heating the polyamic acid of (i) is from 50 ° C to 200 ° C, preferably from 60 ° C to 170 ° C. The reaction time is from 1 hour to 8 hours, preferably from 3 hours to 5 hours. When the reaction temperature is lower than 50 ° C, the dehydration ring closure reaction cannot be sufficiently performed, and if the reaction temperature exceeds 200 ° C, the molecular weight of the obtained polyimine may be small.

On the other hand, in the method of (ii) adding a dehydrating agent and a dehydration ring-closure catalyst to a solvent of polyproline, the dehydrating agent may be an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride. The amount of the dehydrating agent used varies depending on the imidization ratio to be achieved, but is preferably 0.01 mol to 20 mol per mol of the proline structure of 1 mol of polylysine.

Further, as the dehydration ring-closure catalyst, for example, a tertiary amine such as pyridine, trimethylpyridine, dimethylpyridine or triethylamine can be used, but it is not limited thereto. The amount of the dehydration ring-closing catalyst used is selected from 0.01 mol to 10 mol with respect to the 1 mol dehydrating agent used. The more the amount of the dehydrating agent and the dehydration ring-closing agent used, the higher the yield of hydrazine. As the organic solvent used for the dehydration ring closure reaction, an organic solvent which has been enumerated for the synthesis of polyamic acid can be used.

The reaction temperature of the dehydration ring closure reaction is from 0 ° C to 180 ° C, preferably from 10 ° C to 150 ° C. The reaction time is from 1 hour to 8 hours, preferably from 3 hours to 5 hours. The polyimine obtained in the method (i) can be used directly for preparing a liquid crystal alignment agent, or the obtained polyimine can be purified before being used in the preparation of a liquid crystal alignment agent.

On the other hand, the polyimine-containing reaction solution obtained in the method (ii) is dissolved. The liquid can be directly used for preparing the liquid crystal alignment agent, and can also be used in the preparation of the liquid crystal alignment agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, and can also be separated in the liquid crystal alignment after the polyimine is separated. The preparation of the liquid crystal alignment agent is used after the preparation of the agent or the purification of the separated polyimine. As a method of removing the dehydrating agent and the dehydration ring-closure catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The separation and purification of the polyimine can be carried out in the same manner as the separation and purification of the above polyamic acid.

The liquid crystal alignment agent of the present invention comprises the above polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine compound or a polyamidamine obtained by dehydration ring closure of polyglycine, a photoactive crosslinking compound. And other additives added as needed, preferably, the plurality of components are contained in the liquid crystal alignment agent by being dissolved in an organic solvent.

The organic solvent which can be used in the liquid crystal alignment agent of the present invention may be, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethoxypropyl Ethyl acetate, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (Butyl Cellosolve, or ethylene glycol) Monobutyl 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, 3-butoxy-N,N-dimethylpropane decylamine, 3-methoxy-N,N-dimethylpropane decylamine, 3-hexyloxy-N,N-dimethylpropane decylamine and the like.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent in the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent), considering viscosity, volatility, etc. The factor must be appropriately selected, and may preferably range from 1% by weight (% by weight) to 10% by weight (% by weight). When the concentration of the solid matter is less than 1% by weight (wt%), the thickness of the film formed by coating the liquid crystal alignment agent is too thin to obtain a good liquid crystal alignment film, and on the other hand, when the solid concentration is When the content exceeds 10% by weight (wt%), the thickness of the formed film is too thick, and a good liquid crystal alignment film is not obtained as well, and the viscosity of the liquid crystal alignment agent is increased to lower the coating characteristics.

According to an embodiment of the present invention, a liquid crystal alignment agent can be prepared by adding the photoactive crosslinking compound of the present invention to the polyamic acid.

Further, according to another embodiment of the present invention, a liquid crystal alignment agent can also be prepared by adding the photoactive crosslinking compound to a polyimine obtained from polyamic acid.

When UV is applied to the liquid crystal alignment agent containing the photoactive crosslinking compound, a photoreactive group in the structure of the photoactive crosslinking compound forms a crosslinked structure, thereby guiding the liquid crystal alignment film to achieve effective vertical alignment.

The photoactive crosslinking compound can further improve the stability of the pretilt angle and the film strength of the formed liquid crystal alignment film, and can perform photoalignment by UV exposure in a frictionless state.

According to an embodiment of the present invention, the liquid crystal alignment agent may contain 0.1 part by weight to 40 parts by weight of the photoactive crosslinking compound, preferably may contain, relative to 100 parts by weight of the polyaminic acid or polyimine. 0.1 parts by weight to 30 parts by weight. If the content of the photoactive crosslinking compound is less than 0.1 weight However, there is no effect of improving the vertical alignment, and if the content of the photoactive crosslinking compound exceeds 40 parts by weight, the basic properties of the liquid crystal alignment agent are lowered.

Liquid crystal alignment film and liquid crystal display device

The liquid crystal alignment film can be formed by applying the liquid crystal alignment agent of the present invention to a substrate and heating it.

The liquid crystal alignment agent can be applied by, for example, a roll coating method, a spin method, a printing method, an inkjet method, or the like, and then the surface is coated by heating to form a liquid crystal alignment film.

After the liquid crystal alignment agent is applied, in order to prevent the flow of the applied alignment agent liquid, it is preferable to perform preheating (prebaking). The pre-bake temperature is preferably from about 30 ° C to about 300 ° C, more preferably from about 40 ° C to about 200 ° C, and most preferably from about 50 ° C to about 150 ° C.

Thereafter, the solvent is completely removed, and in order to thermally imidize the polyglycolic acid, a firing (post-baking) process can be performed. The firing (post-baking) temperature is preferably from about 80 ° C to about 300 ° C, more preferably from about 120 ° C to about 250 ° C. Thus, the liquid crystal alignment agent containing poly-proline can also be applied, and then the organic solvent is removed to form a coating film which is to be a liquid crystal alignment film, and dehydration ring closure is performed by heating to form an alignment film which is further imidized. . The film thickness of the formed liquid crystal alignment film is preferably from about 0.001 μm to about 1 μm, more preferably from about 0.005 μm to about 0.5 μm.

The alignment treatment may be performed by irradiating the surface of the dried coating film with ultraviolet rays having a wavelength ranging from about 150 nm to about 450 nm. At this time, an energy having an exposure intensity of about 50 mJ/cm ² to about 10 J/cm ² may be irradiated, preferably an energy of about 500 mJ/cm ² to about 5 J/cm ² .

Through the aforementioned light alignment and a series of processes, a liquid crystal alignment film having excellent thermal stability and high alignment property can be obtained.

Further, a liquid crystal display device having the liquid crystal alignment film can be prepared by a conventional method in the technical field to which the present invention pertains. For example, after the resin adhesive is applied to the outer edge portions of the two substrates on which the liquid crystal alignment film is formed, the liquid crystal alignment film is laminated in a face-to-face state, and the adhesive is cured, and then the liquid crystal is liquid crystal. The injection inlet is injected between the substrates, and the liquid crystal injection port is sealed to prepare a liquid crystal display device.

Hereinafter, the present invention will be described in more detail by way of examples. It should be understood by those skilled in the art that these examples are not intended to limit the scope of the invention.

<Example> Preparation of photoactive crosslinking compounds Example 1: Preparation of Chemical Formula 20 (n=1, R ₁ ~R ₈ Photoactive cross-linking compound at =H)

The starting material 4,4,4-trifluorobutan-1-ol (4,4,4-trifluorobutan-1-ol) (chemical formula 1) (95.0 g, 0.74 mol) was dissolved in triethylamine (TEA) (135 mL, 0.97 mol) and 1 L of dichloromethane (Methylene Chloride, MC) and cooled to 0 °C. Slowly add methanesulfonate chloride to the resulting material within 30 minutes (methanesulfonyl chloride, MsCl) (63.0 mL, 62.0 mol). The mixture was stirred at 0 ° C for 10 minutes and allowed to react at room temperature for 2 hours to prepare 4,4,4-trifluorobutyl methanesulfonate (Chemical Formula 2). ).

Methyl-hydroxybenzoate (Chemical Formula 3) (87.3 g, 0.57 mol), K ₂ CO ₃ (95.2 g, 0.69 mol) and 4,4,4-trifluoromethanesulfonate 4,4,4-trifluorobutyl methanesulfonate (Chemical Formula 2) (130.3 g, 0.63 mol) was added to 2 L of acetonitrile and refluxed for 12 hours. The reactant is cooled to normal temperature and subjected to extraction to prepare a compound of Chemical Formula 4. The compound of Chemical Formula 4 (160 g, 0.57 mol) was added to 1.5 L of methanol, and 370 mL of 25% sodium hydroxide (NaOH) was added thereto to carry out a reaction for 4 hours to prepare a compound of Chemical Formula 5.

In the autoclave, 4-nitrocinnamic acid (chemical formula 6) (110 g, 0.57 mol), 1.5 L of methanol, and humidity were added. 50% of 10% of Pd/C (11.0 g, 10% w/w) was reacted in a hydrogen (3 atm) atmosphere for 24 hours to prepare a compound of Chemical Formula 7.

The compound of formula 7 (95.0 g, 0.57 mol) was dissolved in 1,4-dioxane (1 L) / Na ₂ CO ₃ (120.6 g, at 1.2 L of H ₂ After adding Boc ₂ O (149 g, 0.68 mol) at 0 ° C, it was reacted at room temperature for 3 hours to prepare a compound of Chemical Formula 8 (145 g, 96%).

The compound of Chemical Formula 8 (61.0 g, 0.23 mol) and TEA (38.6 mL, 0.27 mol) were added to 700 mL of DME, and ethyl chloroformate (26.3 mL, 0.27 mol) was added at 0 °C. It was allowed to react for 24 hours. The reaction was cooled to 0 ℃, was added _{NaBH 4 (14.8 g, 0.39 mol} ). The mixture was allowed to react for 12 hours to obtain a compound of Chemical Formula 9.

The compound of Chemical Formula 9 (125 g) and PCC (196 g, 0.91 mol) and silica gel (100 g) were added to dichloromethane (Methylene Chloride) (1.7 L), and reacted at room temperature 3 The compound of Chemical Formula 10 (57.8 g) was prepared in an hour.

4-Hydroxyacetophenone (Chemical Formula 11) (100 g, 0.73 mol) was dissolved in EtOAc (1.5 L), and CuBr ₂ (328 g, 1.47 mol) was added at room temperature. It was then refluxed for 12 hours to prepare a compound of Chemical Formula 12. The compound of Chemical Formula 12 (116 g, 0.54 mol) and 3,4-dihydro-2H-pyran (200 mL, 2.16 mol) were added to contain PPTS (4.10 g, 0.016 mol) of 1.5 L of dichloromethane (Methylene Chloride) was allowed to react at room temperature for 4 hours to prepare a compound of Chemical Formula 13.

The compound of Chemical Formula 13 (175 g, 0.54 mol) and PPh ₃ (145 g, 0.55 mol) were added to acetonitrile (1.5 L), and allowed to react at room temperature for 6 hours to prepare Chemical Formula 14 Compound. After dissolving the compound of Chemical Formula 14 (290 g, 0.52 mol) in THF (2.5 L), 2 M of Na ₂ CO ₃ (2 L) was added and reacted for 12 hours to prepare a compound of Chemical Formula 15 (226 g, 91%).

A compound of Chemical Formula 10 (73.8 g, 0.29 mol) and a compound of Chemical Formula 15 (171 g, 0.36 mol) prepared in Reaction Scheme 4 were dissolved in toluene and refluxed for 7 hours to prepare a chemical formula. Compound of 16 (102 g, 76%).

The compound of Chemical Formula 16 (102 g, 0.22 mol) was dissolved in 2.0 L of dichloromethane (Methylene Chloride), and TFA (200 mL) was added at 0 ° C for 1 hour. This was reacted at room temperature for 4 hours to prepare a compound of Chemical Formula 17 (70.2 g, 91%).

The compound of Chemical Formula 17 (70.2 g, 0.20 mol) was dissolved in 200 mL of AcOH, and epichlorohydrin (20.3 g, 0.22 mol) was added and reacted for 12 hours to prepare a compound of Chemical Formula 18 (85.0 g, 92%). A compound of Chemical Formula 18 (85.0 g, 0.18 mol) and PPTS (5.67 g, 0.02 mol) were added to methanol, and reacted for 4 hours to prepare a compound of Chemical Formula 19 (60.0 g, 88%).

The compound of Chemical Formula 19 (60.0 g, 0.16 mol) was dissolved in 1 L of dichloromethane (Methylene Chloride), and the compound of Chemical Formula 5 (51.0 g, 0.20 mol) prepared by the reaction formula 2 was added at a temperature of 10 ° C, EDCI. (45.9 g, 0.25 mol), DMAP (10.4 g, 0.09 mol) and DIPEA (89.0 mL, 0.51 mol). After reacting for 12 hours at room temperature, the product was extracted and obtained, and the product was purified by column chromatography [MC / EtOAc (20:1)) to give the compound of formula 20 (91.4 g, 94). %).

Example 2: Preparation of Chemical Formula 40 (n=1, R ₁ ~R ₄ Photoactive cross-linking compound at =H)

4-Hydroxyacetophenone (Chemical Formula 25) (72.5 g, 0.53 mol) was dissolved in DMF (700 mL) to react with the methanesulfonic acid 4,4 prepared in Reaction Scheme 1 of Example 1. , 4,4,4-trifluorobutyl methanesulfonate (Chemical Formula 2) (152 g, 0.64 mol) and K ₂ CO ₃ (110 g, 0.80 mol) are reacted to prepare a compound of formula 26 ( 98.0 g, 75%).

The compound of Chemical Formula 26 (98.0 g, 0.4 mol) was dissolved in MC/MeOH (2:1, 1.2 L), and Bu ₄ NBr ₂ (192 g, 0.4 mol) was slowly added at a temperature of 10 °C. This was allowed to react for 12 hours to prepare a compound of the formula 27 (120 g, 93%).

The compound of the formula 27 (120 g, 0.4 mol) was added to triethylphosphite (193 mL, 1.11 mol), and refluxed for 4 hours to prepare a compound of the formula 28 (60 g, 43%) ).

Benzophenone (Chemical Formula 29) (100 g, 0.55 mol) and KOH (30.8 g, 0.55 mol) were added to acetonitrile (700 mL) and refluxed for 2 hours to prepare a chemical formula. 30 Compound (98.0 g, 87%). Slowly add a 2.5 M BuLi solution (2.5 M solution in hexane) in a mixture of acetonitrile (88.0 mL, 1.67 mol) and THF (900 mL) at a temperature of -78 ° C under a nitrogen atmosphere. Hexane) (480 mL, 1.19 mol), stirred for 3 hours, and then added a compound of formula 30 (98.0 g, 0.48 mol) and THF (600 mL), and allowed to react for 3 hours to prepare a compound of formula 31 (102 g , 87%).

Concentrated sulfuric acid (460 mL) and fuming nitric acid (69.1 mL) were cooled to between 0 and -5 ° C, and a compound of formula 31 (91.5 g, 0.37 mol) was added. This was reacted at 10 ° C for 5 hours to prepare a compound of Chemical Formula 32 (103 g, 83%). A compound of the formula 32 (109 g, 0.32 mol) was added to 50% H ₂ SO ₄ (2 L, v/v), and reacted at 150 ° C to lower the temperature to room temperature. The compound of Chemical Formula 33 is then prepared by extracting the reactants.

The compound of Chemical Formula 33 (143 g, 0.32 mol) was dissolved in EtOH (1 L), and HCl was added, and then refluxed for 12 hours to prepare a compound of formula 34 (129 g, 94%). The compound of formula 34 (129 g, 0.30 mol), methanol (1.5 L) and 10% Pd/C (20 g, 20% w/w) were added to the autoclave and reacted under a hydrogen (3 atm) atmosphere. The compound of Chemical Formula 35 was prepared for 24 hours.

The compound of the formula 35 (113 g, 0.30 mol) was dissolved in 300 mL of AcOH, and epichlorohydrine (33.3 g, 0.36 mol) was added and reacted for 12 hours to prepare a compound of the formula 36 (148). g, 83%). Compound of formula 36 (148.6 g, 0.25 mol) After dissolving in EtOH (1 L) and adding NaOH (20 g, 0.50 mol) aqueous solution, it was refluxed for 3 hours to prepare a compound of formula 37 (107.7 g, 80%).

The compound of the formula 37 (107.7 g, 0.20 mol) was dissolved in THF (1 L), and BH3SMe2 (45.5 g, 0.60 mol) was slowly added at 0 ° C, and then reacted at 50 ° C for 5 hours to prepare a chemical formula 38. Compound. Further, a compound of the formula 38 (91.9 g, 0.18 mol) was dissolved in an acetonitrile (1.5 L) solution, and 4-formylbenzoic acid (80.6 g, 0.54 mol), EDCI (148.4 g, 0.72) was added. Mol), DMAP (12.4 g, 0.11 mol) and DIPEA (78.3 mL, 0.45 mol) were reacted at 10 ° C to give the compound of formula 39 (77.4 g, 55%).

The compound of Chemical Formula 28 (93.5 g, 0.25 mol) prepared in the reaction formula 6 was dissolved in DMF (600 mL), and a solution of 60% NaOH (9.72 g, 0.25 mol) in DMF (400 mL) was added thereto. The reaction was carried out for 24 hours. This was mixed with a solution of the compound of formula 39 (77.4 g, 0.10 mol) in DMF (600 mL), and allowed to react at room temperature for 14 hours, then by column chromatography [hexane/acetic acid] Ethyl ester (2:1)] was purified to give the compound of formula 40 (86.1 g, 70%).

Preparation of liquid crystal alignment agent Example 3

0.75 g of 4,4-methylenediamine (MDA), 1.02 g of p-phenylenediamine (p-PDA) and 5.62 g of cholesteryl (3,5-diaminobenzoate) , CDB), dissolved in 69.0 g of N-methyl-2-pyrrolidone (NMP) under a nitrogen atmosphere, and then added 5.40 g of 2,3,5-tricarboxycyclopentyl group while maintaining 20 ° C 2,3,5-tricarboxy cyclopentyl hydride anhydride (TCAAH). Thereafter, 46.0 g of γ-butyrolactone (GBL) was added and allowed to react for 24 hours. After the reaction, 51.13 g of γ-butyrolactone (GBL), 3.83 g of N-methyl-2-pyrrolidone (NMP) and 72.9 g of ethylene glycol monobutyl ether (BC) were added to obtain a 5 wt% poly Proline solution. (viscosity 12 cP, 25 ° C)

The photoactive crosslinking compound of this Example 1 was added thereto so that the concentration of the photoactive crosslinking compound was 5 wt% to prepare a liquid crystal alignment agent.

Comparative example 1

A liquid crystal alignment agent was prepared by the same method as in Example 3 except that the aforementioned photoactive crosslinking compound was not added.

Preparation of liquid crystal alignment film and liquid crystal display device

The liquid crystal alignment agent obtained in Example 3 and Comparative Example 1 was separately filtered with a filter device having a pore size of 1 μm. Using a rotating device, at 500 rpm and a rotation time of 10 seconds, and a rotation speed of 1800 rpm and a rotation time of 20 seconds, the transparent conductive film having an ITO film disposed on one surface of the glass substrate was coated in two steps. The liquid crystal alignment agent was removed by pre-curing at 180 ° C for 60 seconds and main curing at 210 ° C for 20 minutes to form a coating film.

Thereafter, the substrate was exposed to an intensity of 300 mJ/cm ² and 10 mW for 30 seconds using an exposure apparatus to prepare two substrates having a liquid crystal alignment film. Then, after coating the outer edge portions of the two liquid crystal alignment films and the outer edge portions of the liquid crystal alignment film, an epoxy resin binder containing alumina balls having a diameter of 4 μm is applied, and the liquid crystal alignment film is faced to face to face. The two substrates are laminated and then the adhesive is cured. Then, the nematic liquid crystal (n _e 1.5601, n _o 1.4780) was filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to prepare a liquid crystal display device.

<Experimental example> Physical property evaluation of liquid crystal display device Evaluation method Stickiness

The dynamic viscosity was measured at 25 ° C using a cannon viscometer, and after measuring the specific gravity by a hydrometer, the two measured values were multiplied to calculate the viscosity.

2. Pretilt angle

According to the method described in the literature (T.J. Schffer et al., 1980 J., Appl., Phys., Journal, Vol. 19, p. 2013), it was measured by a crystal rotation method using a He-Ne laser.

3. The alignment of liquid crystal

When the voltage of the liquid crystal display device was turned on/off, the presence or absence of an abnormal liquid crystal region in the liquid crystal display device was observed with a microscope, and it was judged to be good when there was no abnormal liquid crystal region.

4. Voltage maintenance rate

After a voltage of 5 V was applied to the liquid crystal display device for 60 μsec, the voltage holding ratio after the application of the voltage of 16.67 msec was released was measured.

The physical property evaluation results of the liquid crystal display devices prepared in Example 3 and Comparative Example 1 of the present invention are shown in Table 1 below. Moreover, photos before and after exposure are shown in FIGS. 1 and 2.

Fig. 1 is a view showing a liquid crystal alignment photograph of a liquid crystal display device prepared in Example 3 of the present invention. In Fig. 1, the left side is before exposure and the right side is after exposure.

2 shows a liquid crystal alignment photograph of the liquid crystal display device prepared in Comparative Example 1. In Fig. 2, the left side is before exposure and the right side is after exposure.

With reference to the above Table 1, FIG. 1 and FIG. 2, the liquid crystal display device prepared according to the embodiment of the present invention can be confirmed to have better characteristics than the liquid crystal display device produced by the comparative example because of excellent post-exposure characteristics. Moreover, according to the liquid crystal display device prepared according to the embodiment of the present invention, no domain is observed after the exposure, and thus the alignment state is excellent. However, the crystal domain difference of the liquid crystal display device of the comparative example before and after the exposure is It is not so large that it is known that the alignment state is poor.

Fig. 1 is a view showing a liquid crystal alignment photograph of a liquid crystal display device prepared in Example 3 of the present invention.

2 shows a liquid crystal alignment photograph of the liquid crystal display device prepared in Comparative Example 1.

Claims (12)

A photoactive crosslinking compound represented by the following chemical formula I, In the chemical formula I, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20. The photoactive crosslinking compound according to claim 1, wherein the compound of the formula I is selected from the group consisting of the following compounds of the formula 20, the formula 22 and the compound of the formula 24: In the chemical formulas 20, 22 and 24, R ₁ to R ₈ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, And any one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20. A photoactive crosslinking compound represented by the following chemical formula II, In the chemical formula II, any one of X ₁ , X ₂ , X ₃ and X ₄ is And the rest are H; R ₁ to R ₈ are the same or different, and are independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; A is or B is or n is an integer from 1 to 20. The photoactive crosslinking compound according to claim 3, wherein the compound of the formula II is represented by the following chemical formula 40, In the formula 40, R ₁ to R ₄ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, and a carbon number. Any one of 1 to 10 alkoxy groups; n is an integer of 1 to 20. A liquid crystal alignment agent comprising the photoactive crosslinking compound according to any one of claims 1 to 4, and polylysine or polyimine. The liquid crystal alignment agent according to claim 5, wherein the photoactive crosslinking compound is contained in an amount of from 0.1 part by weight to 40 parts by weight per 100 parts by weight of the polyamic acid or polyimine. The liquid crystal alignment agent according to claim 5, wherein the polyamic acid is reacted by reacting a monoamine compound and a tetracarboxylic dianhydride. Prepared. The liquid crystal alignment agent according to claim 7, wherein the diamine compound comprises a compound selected from the group consisting of p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4, 4'-Diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl hydrazine, 3,3'-dimethyl-4,4'- Diaminobiphenyl, 4,4'-diaminophenyl benzophenone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4 , 4'-diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 6-amino-1-(4'-amine Benzo)-1,3,3-trimethylindan, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminodi Benzophenone, 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]indole , 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9 , 9-bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminopurine, 9,9-bis(4-aminophenyl)anthracene, 4,4'-methylene-bis (2-chloroaniline), 2, 2', 5, 5'-four -4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy -4,4'-diaminobiphenyl, 1,4,4'-(p-phenylene isopropylidene)diphenylamine, 4,4'-(m-phenylene isopropylidene) double Aniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)benzene]hexafluoropropane, 4,4'-diamino-2,2'-bis (three Fluoromethyl)biphenyl, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, bis(4-aminophenyl)benzidine, 1- (4-Aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1,1-m-xylylenediamine, 1,3-propanediamine, tetramethylene Amine, pentamethylenediamine, hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 1,4-cyclohexanediamine, isophoronediamine, tetrahydrobicyclopentadienyl Diamine, tricyclo[6.2.1.0 ^2,7 ]-undecene dimethyldiamine, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl) ring Hexane, 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3 - dicyanpyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4 -bis(3-aminopropyl)perazine Pyrazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2 ,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3 , 5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6 -diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxy acridine lactate, 3,8-Diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis(4-aminophenyl)aniline, 1-(3 And one or more of the group consisting of 5-(diaminophenyl)-3-mercaptosuccinimide and 1-(3,5-diaminophenyl)-3-octylsuccinimide Diamine compounds. A liquid crystal alignment film formed by the liquid crystal alignment agent described in claim 5 of the patent application. A liquid crystal display device having the liquid crystal alignment film according to claim 9 of the patent application. A method for producing a photoactive crosslinking compound, which is represented by the following Chemical Formula 20, which comprises the steps of reacting a compound represented by the following Chemical Formula 19 with a compound represented by the following Chemical Formula 5, In the chemical formulas 5, 19 and 20, R ₁ to R ₈ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, And any one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20. A method for producing a photoactive crosslinking compound, which is represented by the following Chemical Formula 40, which comprises the steps of reacting a compound represented by the following Chemical Formula 39 with a compound represented by the following Chemical Formula 28, In the chemical formulas 28, 39 and 40, R ₁ to R ₄ are the same or different, and are each independently selected from the group consisting of H, CN, NO ₂ , CF ₃ , halogen, an alkyl group having 1 to 10 carbon atoms, And any one of alkoxy groups having 1 to 10 carbon atoms; n is an integer of 1 to 20.