KR100850630B1 - Composition for liquid crystal aligning layers and liquid crystal display - Google Patents

Abstract

The present invention provides a photoreactor comprising: (a) a photoreactor exhibiting at least one photoisotropy; And (b) a liquid crystal alignment agent comprising two or more photopolymerizable (meth) acryl group-containing substituents, a liquid crystal alignment film composition comprising the liquid crystal alignment agent, and a liquid crystal alignment film manufactured using the composition. To provide.

Since the low molecular type liquid crystal aligning agent according to the present invention includes an acrylic or methacryl group which can be polymerized by light energy in the molecule, it has excellent sensitivity to photoreaction and excellent thermal stability through formation of an alignment film having a solid network structure by light irradiation. And electro-optical properties.

Liquid crystal, alignment film, low molecular weight, photofunctionality, liquid crystal display element

Description

Composition for liquid crystal aligning film and liquid crystal display element using same TECHNICAL FIELD {COMPOSITION FOR LIQUID CRYSTAL ALIGNING LAYERS AND LIQUID CRYSTAL DISPLAY}

FIG. 1 is a view showing a correlation between an alignment state of an alignment film and an alignment property of a liquid crystal cell when the liquid crystal cell having a substrate coated with an alignment film is disposed between two polarizers having perpendicular polarization directions.

FIG. 2 is a photograph obtained by observing a liquid crystal cell manufactured using a liquid crystal aligning agent according to Examples 1 to 3 and Comparative Example 1 between two polarizers having polarization directions perpendicular to each other.

Figure 3 is a liquid crystal cell prepared using the liquid crystal aligning agent according to Examples 1 to 3 and Comparative Example 1 after the thermal stability test (left at 200 ℃) observed between two polarizers having a polarization direction orthogonal It is a photograph.

The present invention relates to a liquid crystal aligning agent having both excellent alignment and thermal stability at the same time, a composition for a liquid crystal alignment film containing the liquid crystal aligning agent and a liquid crystal display device using the same.

Liquid crystal display (LCD) uses an alignment film. The alignment layer mainly uses a polymer material, and acts as a director in the arrangement of the liquid crystal molecules, so that the liquid crystal is moved by an electric field to form an appropriate direction when forming an image. In general, in order to obtain uniform brightness and high contrast ratio in the liquid crystal display device, it is essential to orient the liquid crystal uniformly.

Conventional methods for orienting liquid crystals include a rubbing method in which a polymer film such as polyimide is applied to a substrate such as glass, and the surface is rubbed with a fiber such as nylon or polyester in a predetermined direction. However, the rubbing method may generate fine dust or electrostatic discharge (ESD) when the fiber and the polymer film are rubbed, and these may cause serious problems in manufacturing the liquid crystal panel.

In order to solve the problem of the rubbing method, a photo-alignment method for inducing anisotropy (anisotropy) to a polymer film by light irradiation instead of friction and arranging liquid crystals using the same has been studied. Materials that can be used in the photo-alignment method include polymers containing photofunctional functional groups such as azobenzene, cumarine, chalcone and cinnamate. As a result, a reaction such as photoisomerization or photocrosslinking occurs anisotropically, whereby anisotropy is generated on the surface of the polymer to align the liquid crystals in one direction. However, optical and thermal stability is indispensable for the practical use of such photo-orientation materials. Conventional polymer materials have many disadvantages in this respect.

On the other hand, the conventional liquid crystal photo-alignment film material is mostly of a polymer type, and has a photofunctional group capable of inducing optical anisotropy such as azobenzene or cinnamate as a side group in the polymer main chain. When using such a polymer liquid crystal photoalignment film material, not only a large amount of light energy is required to induce anisotropy, but also a large number of unreacted photofunctional groups that remain unreacted have a serious effect on thermal, light stability, and electro-optic properties in the future. Can have

The inventors of the present invention can solve the above-mentioned problems as well as solve the above-mentioned problems by using a low-molecular-type liquid crystal aligning agent including a substituent polymerizable by intramolecular light instead of the polymer type liquid crystal aligning agent used as a conventional liquid crystal aligning film material. It has been found to exhibit good orientation properties, excellent thermal stability and improved electro-optical properties for.

Accordingly, the present invention provides a liquid crystal display including a low molecular liquid crystal aligning agent having excellent liquid crystal alignment properties and thermal stability including a photopolymerization substituent, a composition for a liquid crystal aligning film including the liquid crystal aligning agent, and an alignment film prepared by using the composition. It is an object to provide an element.

The present invention provides a photoreactor comprising: (a) a photoreactor exhibiting at least one photoisotropy; And (b) a liquid crystal aligning agent comprising two or more photopolymerizable (meth) acryl group-containing substituents, a composition for a liquid crystal alignment film comprising the compound, and a liquid crystal alignment film prepared using the composition. do.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is characterized by using a low molecular type liquid crystal aligning agent including a substituent which can be polymerized by light energy instead of a photo-alignment polymer type used as a conventional liquid crystal aligning agent.

The low molecular type liquid crystal aligning agent includes a photoalignment moiety capable of arranging liquid crystal molecules by at least one photoreaction in one molecule, and a substituent which can be polymerized by at least two or more photoreactions such as an acrylic group and / or As a structure containing a methacryl group, such a characteristic can exhibit the following effects.

1) Since the liquid crystal aligning agent of the present invention can form a very rigid net structure film by optical energy due to photopolymerization substituents such as acrylic groups or methacryl groups included in the molecular structure, it can exhibit excellent thermal stability and electro-optical properties. have.

2) Also, since it is a low molecular type having a much higher sensitivity to photoreaction than a polymer type, it can easily implement anisotropy even at a small light energy.

3) Due to the excellent solubility, not only is the solvent selected for coating the film (coating) advantageous, but also there is an advantage that the fineness can be easily adjusted in terms of purity required as an electronic material.

The liquid crystal aligning compound according to the present invention is anisotropic in the molecular light anisotropy, that is, polarized light irradiation The compound containing the photoreactor shown and the photopolymerizable substituent, such as an acryl group and / or a methacryl group, can be used, It is especially preferable to have a photoreactor which shows one or more photo anisotropy, and two or more photopolymerizable substituents.

In addition to the acryl group and / or methacryl group mentioned above, the compound for liquid crystal aligning which has a substituent which can be superposed | polymerized by light energy also belongs to the scope of the present invention.

The liquid crystal aligning agent may include a basic structure represented by the following Chemical Formula 1.

(Ⅰ)

(Ⅰ)

Where

A is a part including an optical functional reactor capable of inducing anisotropy by light energy incident on polarized light,

C is a part which superposition | polymerizes by light energy, and it is a (meth) acryl group containing substituent,

B is a linking group of A and C,

n is an integer between 2 and 6.

At this time, the photoreactor (A) is preferably selected from the group consisting of azobenzene, stilbenzene, coumarin, chalcone and cinnamate, B is ether (ether) unsubstituted or substituted with nitrogen (N) or sulfur (S) At least one selected from the group consisting of alkyl having 1 to 20 carbon atoms, ester having 3 to 18 carbon atoms, cycloalkyl having 3 to 18 carbon atoms and aryl groups having 5 to 18 carbon atoms, More preferably, at least one to five carbons are substituted with N or S.

Specific examples of the compound having a basic structure represented by Formula 1 according to the present invention include, but are not limited to, the compounds of Formulas 2 to 4.

Each liquid crystal aligning agent represented by Chemical Formulas 2 to 4 is a novel compound, and an esterification reaction using alkylation and / or acid halide using hydroxy alkyl halide. ) And the like. However, it is not limited by the above-mentioned manufacturing method, and may be prepared according to conventional methods known in the art.

The molecular weight of the low molecular liquid crystal aligning agent according to the present invention is not particularly limited, but is preferably 10,000 or less, particularly preferably in the range of 300 to 5000. When the molecular weight is less than 300, the thin film is not formed well, and when the molecular weight is more than 5000, the polymer is close to the polymer, and thus the characteristics (photoreaction sensitivity) pursued by the present invention may be considerably deteriorated.

The liquid crystal aligning agent may form a liquid crystal aligning film as a single component to form a liquid crystal aligning film through photopolymerization, but if possible, includes a photo initiator, a multi-cross linker, or a combination thereof. It is preferable.

Here, the photo initiator is a radical that is generated by the light energy to cause a photopolymerization reaction, it is possible to use a conventional photoinitiator known in the art.

The content of the photoinitiator is not particularly limited, but if possible, it is appropriate to use in the range of 0 to 20% by weight per 100% by weight of the composition for liquid crystal alignment film, preferably about 5% by weight. When the content of photoinitiator exceeds 20% by weight While firm film formation can proceed more quickly, the content of the liquid crystal aligning agent may be reduced, which may be unsatisfactory and may adversely affect the liquid crystal orientation.

A multi-cross linker may be used to more effectively form a rigid film when the liquid crystal aligning agent causes a polymerization reaction by light energy, and may easily connect the aforementioned liquid crystal aligning molecule.

The multicross linker may be used a conventional one known in the art, it is particularly preferable to use those represented by the formula (5).

(Ⅱ)

(Ⅱ)

Where

D is a linking group, E is a polymerizable substituent, and m is an integer between 2 and 10.

In this case, the linking group (D) is alkyl having 1 to 20 carbon atoms having 3 to 20 carbon atoms, having 3 to 20 carbon atoms having a linking group of ether, ester, amide substituted or unsubstituted with nitrogen (N), sulfur (S) It is one or more selected from the group consisting of 18 cycloalkyls and aryl groups having 5 to 18 carbon atoms, particularly preferably at least 1 to 5 carbons substituted with N or S. Moreover, it is preferable that the substituent (E) which can superpose | polymerize is an acryl group and / or a methacryl group.

The content of the multicross linker is not particularly limited, but preferably 0 to 50% by weight per 100% by weight of the composition for the liquid crystal alignment film. If it is more than 50% by weight, it is easy to form a film of a rigid network structure, but may interfere with the liquid crystal alignment.

The composition for a liquid crystal alignment film of the present invention may further include conventional additives known in the art, in addition to the above components.

In addition, the present invention provides a liquid crystal alignment layer (liquid crystal alignment layer) prepared using the above-described composition for liquid crystal alignment film.

In this case, the liquid crystal alignment layer may be prepared according to a conventional method known in the art, for example, i) a photoreactor exhibiting one or more photoisotropy and two or more photopolymerizable substituents, preferably (meth) acrylic Preparing a solution by dissolving a composition for a liquid crystal alignment film containing a liquid crystal aligning agent having a group-containing substituent in an appropriate solvent; ii) applying the solution onto a substrate, removing the solvent, and then irradiating with light.

First, 1) The liquid crystal aligning film composition of this invention is dissolved in a solvent, and the liquid crystal aligning solution is manufactured.

Non-limiting examples of solvents that can be used include N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), dimethylformamide (DMF), butyl cellosolve, γ-butyrolactone, chlorobenzene, Dimethyl sulfoxide (DMSO), dimethylacetamide, cyclopentanone, cyclohexanone, tetrahydrofuran (THF), dichloroethane or mixtures thereof.

The concentration of the nonvolatile matter in the liquid crystal alignment solution is not particularly limited and may be appropriately adjusted according to the coating method to be used. If possible, a range of 1 to 30% by weight per 100% by weight of the total solution is preferred.

2) The liquid crystal alignment solution is applied to a substrate, such as a glass substrate, and then the solvent is removed and then irradiated with light.

As a method of coating the liquid crystal alignment solution on a substrate, methods such as roll coating, curtain coating, spin coating, slot die coating, various printing, deposition, and the like, which are known in the art, may be used. Can be used.

A substrate is a substrate normally used as a photo-alignment film, and a glass substrate is preferable. The thickness of the liquid crystal aligning agent applied on the substrate is not particularly limited and may be adjusted within a conventional range for aligning the liquid crystal, such as 30 to 150 nm. In addition, the method for removing the solvent is also not particularly limited, and may be performed by, for example, heating for about 10 minutes to 1 hour in a temperature range of 100 to 200 ° C.

By performing light irradiation on the surface of the applied liquid crystal aligning agent layer, the liquid crystal aligning film of this invention is manufactured.

The liquid crystal aligning film is a photopolymerization substituent, such as an acrylic group and / or a methacryl group, present in a molecule of the liquid crystal aligning agent by photoirradiation to cause a photopolymerization reaction to form a cross-linked polymer film and at the same time liquid crystal aligning molecule Photoreactors such as azobenzene, coumarin, chalcone, or cinnamate contained within show photoisotropy to express a photoalignment function.

Irradiation light is not particularly limited, but ultraviolet (UV) light is preferred. In addition, the light irradiation method is also not particularly limited, but may be inclined irradiation or vertical irradiation of ultraviolet rays linearly polarized using a polarizer or unpolarized ultraviolet rays not using a polarizer.

The inclination angle at the time of vertical irradiation is adjustable within the range normally performed in the art, among which 0 to 30 degrees is preferred, and the irradiation time depends on the power of the lamp, but preferably 1 second to 1 hour.

In addition, the present invention provides a liquid crystal display (liquid crystal display) having a liquid crystal alignment film prepared using the above-described composition for liquid crystal alignment film.

The liquid crystal display device may be manufactured according to a conventional method known in the art, and for example, two photoreacted substrates having a liquid crystal alignment layer prepared as described above may be formed to have a constant thickness by using an adhesive. (Iii) After adhering between the substrates, the liquid crystal layer is formed by injecting liquid crystal at room temperature, and then treated at a clearing temperature of the liquid crystal for a predetermined time to uniformly align and then cool.

In fact, it was confirmed that the liquid crystal display of the present invention having the liquid crystal alignment layer maintains an excellent alignment state even after undergoing thermal stability test for a long time as well as initial alignment.

Hereinafter, the present invention will be described in more detail by explaining preferred embodiments of the present invention. However, the present invention is not limited by the following examples.

Reference Example 1. Synthesis of 4,4 '-(sebacoyldioxy) dibenzaldehyde (4,4'-(sebacoyldioxy) dibenzaldehyde)

Dissolve 10.3 g of 4-hydroxybenzaldehyde and 12.8 ml of triethylamine in 300 ml of dichloromethane, and then slowly add 11.19 ml of sebacoyl chloride to the solution. Stirred at room temperature for 5 hours. After completion of the reaction, the reaction organic layer was washed with distilled water and concentrated to give 15 g of 4,4 '-(sebacoyldioxy) dibenzaldehyde.

REFERENCE EXAMPLE 2 Synthesis of 4,4 '-(sebacoyldioxy) dicinnamic acid

15 g of 4,4 '-(sebacoyldioxy) dibenzaldehyde, 13.7 g of malonic acid and 1 ml of piperidine were dissolved in 100 ml of pyridine, followed by a temperature of 100 ° C. for 15 hours. Stirred at. After completion of the reaction, the mixture was cooled to room temperature, and the resulting solid was filtered to obtain 14 g of 4,4 '-(sebacoyldioxy) discinnamic acid.

Reference Example 3. Synthesis of 4,4 '-(di ((6-hydroxyhexyl) oxy)) biphenyl (4,4'-(di (6-hydroxyhexyl) oxy)) biphenyl)

Add 0.02 g of potassium iodide (KI) to a methyl ethyl ketone (MEK) solution containing ₃ g of 4,4'-biphenol and 18 g of potassium carbonate (K ₂ CO ₃ ). 6.9 g of 6-bromo-1-hexanol (6-Bromo-1-hexanol) was slowly added dropwise and reacted at 80 ° C. for 24 hours. 100 ml of distilled water was added thereto to terminate the reaction, followed by cooling to room temperature, and the precipitate formed by adding 10% aqueous HCl solution was filtered to obtain 4,4 '-(di ((6-hydroxyhexyl) oxy)) biphenyl (4 3.8 g of, 4 '-(di (6-hydroxyhexyl) oxy)) biphenyl) was obtained (yield: 50%).

Reference Example 4. Synthesis of 4-((6-hydroxyhexyl) oxy) cinnamic acid (4-((6-hydroxyhexyl) oxy) cinnamic acid

A solution of 4.4 g of sodium hydroxide (NaOH) in 20 ml of distilled water was added to a methanol solution in which 7.5 g of 4-hydroxy cinnamic acid was dissolved, and 0.02 g of potassium iodide was added thereto. 10.0 g of 6-bromo-1-hexanol (6-Bromo-1-hexanol) was slowly added dropwise and reacted at 65 ° C. for 24 hours. 100 ml of distilled water was added to terminate the reaction. After cooling to room temperature, the precipitate formed by adding 10% aqueous HCl solution was filtered to obtain 9.5 g of 4-((6-hydroxyhexyl) oxy) cinnamic acid (yield: 60%).

Reference Example 5. Synthesis of 4-((6- (Methacroyl) oxyhexyl) oxy) cinnamic acid (4-((6- (Methacroyloxy) hexyl) oxy) cinnamic acid

5.9 ml of methacryloryl chloride was slowly added dropwise to 30 ml of dimethylformamide (DMF) containing 4.6 g of 4-((6-hydroxyhexyl) oxy) cinnamic acid and 4.4 ml of pyridine, followed by dimethylamino A small amount of pyridine (dimethyl aminopyridine) was added and stirred at room temperature for 24 hours. After completion of the reaction, the precipitate formed by adding 10% aqueous HCl solution was filtered and recrystallized in methanol to obtain 3 g of 4-((6- (methacryloyl) oxyhexyl) oxy) cinnamic acid (yield: 50%).

[Examples 1-3] Liquid crystal aligning agent synthesis, liquid crystal aligning solution, and liquid crystal cell manufacture

Example 1

1-1. Liquid crystal aligning agent synthesis

To 2.6 g of 4,4 '-(sebacoyldioxy) dicinnamic acid prepared in Reference Example 2, 5 ml of thionyl chloride and 0.5 ml of dimethyl formamide (DMF) were added thereto. Boil for an hour. Dionyl chloride remaining after the reaction was distilled under reduced pressure to obtain a solid 4,4 '-(sebacoyldioxy) diicinnamil chloride (4,4'-(sebacoyldioxy) -dicinnamoyl chloride). 20 ml of pyridine and 3.84 ml of 2-hydroxyethyl methacrylate were added thereto, followed by stirring at room temperature for 2 days. After completion of the reaction, excess pyridine was removed under reduced pressure, and the reaction product was dissolved in dichloromethane and washed with distilled water. The organic solution was concentrated and purified by chromatography using silica gel (silica-gel) to obtain 1.9 g of the compound represented by Chemical Formula 2.

1-2. Manufacture of liquid crystal aligning solution (1)

5 wt% of a photoinitiator (Irgacure 369) was added to the alignment material synthesized in Example 1-1, and then dissolved in a mixed solution of N-methylpyrrolidone and butyl cellosolve to adjust the concentration of non-volatile content to 5%. It was used by filtration through a 0.2 ㎛ filter.

1-3. Manufacture of liquid crystal aligning solution (2)

20 wt% of the orientation material synthesized in Example 1-1 and dipentaerythritol hexaacrylate, which is a multi-cross linker, are added thereto, and 5 wt% of the photoinitiator (Irgacure 369) is added thereto. After addition, the solution was dissolved in a mixed solution of N-methylpyrrolidone and butyl cellosolve, and the concentration of nonvolatile matter was 5%, which was used by filtration through a 0.2 µm filter.

1-4. Manufacture of liquid crystal cell using liquid crystal aligning solution (1), (2)

The liquid crystal alignment solutions prepared in Examples 1-2 and 1-3 were coated on a glass substrate coated with an indium tin oxide (ITO) electrode at a thickness of 80 nm, and the glass substrate coated with the alignment agent was then heated at 150 ° C. Drying for 30 minutes removes the solvent. The surface to which the liquid crystal aligning agent was applied was irradiated with ultraviolet rays for 5 seconds to 5 minutes at an inclination angle of 0 degrees and 30 degrees perpendicular to the ultraviolet rays to induce a photoreaction. One of the two glass substrates induced the photoreaction was applied to the end of the photoreactive adhesive containing the ball spacer, and then the other glass substrate was bonded to each other by irradiating UV light only to the portion where the adhesive was applied. After injecting the liquid crystal into the completed cell and heat treatment at 100 ℃ for 5 minutes to complete the liquid crystal cell.

Example 2

0.73 g of 4,4 '-(di ((6-hydroxyhexyl) oxy)) biphenyl prepared in Reference Example 3 and 1.5 g of 4-((6- (methacroyl) oxyhexyl) oxy) cinnamic acid Was dissolved in 25 ml of dimethylformamide, and then 1.15 g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 0.76 g of hydroxybenzootrizole were added thereto. Triethylamine (15.15 ml) was added thereto and reacted at room temperature for 24 hours. Distilled water was added to terminate the reaction, stirred for 30 minutes, and the precipitate was filtered and washed several times with methanol. The filtrate was recrystallized under methylene chloride / normal-hexane conditions to give the compound represented by Chemical Formula 3. 1.0 g was obtained (yield: 40%).

Except for using the liquid crystal aligning agent of Formula 3 prepared in Example 2 instead of the liquid crystal aligning agent prepared in Example 1-1, the same method as in Example 1-2 to Example 1-4 was performed A liquid crystal aligning solution and a liquid crystal cell were prepared.

Example 3

0.46 g of 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane and 4-((6- (methacryloyl) oxyhexyl) oxy prepared in Reference Example 5 above After dissolving 1 g of cinnamic acid in 20 ml of dimethylformamide, 0.77 g of dimethylaminopropylethylcarbodiimide and 0.51 g of hydroxybenzotriazole were added thereto, and 0.8 ml of triethylamine was added thereto at room temperature for 24 hours. Reacted. Distilled water was added to terminate the reaction, stirred for 30 minutes, and the precipitate was filtered and washed several times with methanol. This filtrate was recrystallized under methylene chloride / normal-hexane conditions to give 0.8 g of the compound represented by the formula (4) (yield: 70%).

Except for using the liquid crystal aligning agent of Formula 4 prepared in Example 3 instead of the liquid crystal aligning agent prepared in Example 1-1, the same method as in Example 1-2 to Example 1-4 A liquid crystal aligning solution and a liquid crystal cell were prepared.

Comparative Example 1

According to the same method as Example 1-2 to Example 1-4, except that polyvinyl cinnamate, which is a well-known polymer photoalignment agent, is used instead of the liquid crystal aligning agent prepared in Example 1 A liquid crystal aligning solution and a liquid crystal cell were prepared.

Experimental Example 1. Evaluation of the orientation of the liquid crystal cell

In order to confirm the evaluation of the alignment state of the liquid crystal cell manufactured using the liquid crystal aligning agent according to the present invention, the following experiment was performed.

The liquid crystal cells prepared in Examples 1 to 3 and Comparative Example 1 were used, and their alignment states were confirmed by distinguishing the contrast states between each liquid crystal cell between two polarizing plates having perpendicular polarization directions.

As a result of the experiment, both the liquid crystal cell using the liquid crystal aligning agent of this invention and the liquid crystal cell of the comparative example 1 using a polymeric material showed the excellent orientation state (refer FIG. 2).

Experimental Example 2 Evaluation of Thermal Stability of Liquid Crystal Cell

In order to confirm the thermal stability of the liquid crystal cell manufactured using the liquid crystal aligning agent according to the present invention, the following experiment was performed.

In the manufacturing process of the liquid crystal cell according to Examples 1 to 3 and Comparative Example 1, the mixture was left at 200 ° C. before cooling the liquid crystal, cooled at room temperature, and then injected with liquid crystal.

As a result, it was confirmed that the liquid crystal cell of Comparative Example 1 using the polymer material had an initial alignment state collapsed and hardly oriented (see FIG. 3). In contrast, the liquid crystal cells of Examples 1 to 3 using the liquid crystal aligning agent of the present invention showed an excellent alignment state as in the initial stage, and in particular, even after a long time thermal stability test, it was confirmed that the excellent alignment state was maintained ( 3).

The low molecular liquid crystal aligning agent of the present invention not only exhibits an excellent alignment state with respect to the liquid crystal, but can also realize excellent thermal stability at the same time.

Claims (14)

A liquid crystal aligning agent comprising a photoreactor (A) -linking group (B) -photopolymerization substituent (C) and containing a basic structure represented by the following general formula (I), The liquid crystal aligning agent is characterized in that the acrylic group, the methacryl group, or both of them are photopolymerized by light irradiation to form a cross-linked polymer film and the photoreactor expresses the photo-alignment function. Alignment agent:

(Ⅰ) (Wherein Photoreactor (A) is a photoreactor exhibiting at least one optical anisotropy, Photopolymerization substituent (C) is a substituent containing two or more photopolymerizable acrylic groups, methacryl groups, or both, The linking group (B) is alkyl having 1 to 20 carbon atoms having 3 to 18 carbon atoms and having 3 to 18 carbon atoms having a linking group of ether, ester or amide substituted or unsubstituted with nitrogen (N) or sulfur (S). At least one selected from the group consisting of cycloalkyl and allyl groups having 5 to 18 carbon atoms; n is an integer between 2 and 6). delete The liquid crystal alignment of claim 1, wherein the photoreactor A is a photoreactor selected from the group consisting of azobenzene, stilbenzene, cumarine, chalcone and cinnamate. My. The method of claim 1, wherein the linking group (B) is an alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 18 carbon atoms and carbon atoms having a linking group of ether, ester, and amide in which at least 1 to 5 carbons are substituted with N or S. A liquid crystal aligning agent which is an aryl group of 5-18. The method of claim 1, wherein the liquid crystal aligning agent

,

or

Phosphorus liquid crystal aligning agent. The liquid crystal aligning agent according to claim 1, wherein the molecular weight of the liquid crystal aligning agent is in the range of 300 to 5,000. delete The liquid aligning film composition containing the liquid crystal aligning agent of any one of Claims 1 and 3-6. The composition of claim 8, wherein the liquid crystal alignment film composition comprises a photo initiator, a multi-cross linker, or a photoinitiator and a multicross linker. The composition of claim 9, wherein the content of the photoinitiator is in a range of 0 to 20 wt% per 100 wt% of the liquid crystal alignment film composition. The composition of claim 9, wherein the multi-cross linker is represented by the following general formula (II):

(Ⅱ) Where D is alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 18 carbon atoms and aryl having 5 to 18 carbon atoms having a linkage of ether, ester, amide substituted or unsubstituted with nitrogen or sulfur with an aryl group At least one linker selected from the group consisting of; E is an acryl group or a methacryl group, m is an integer between 2 and 10. The composition of claim 9, wherein the content of the multicross linker is in the range of 0 to 50 wt% per 100 wt% of the liquid crystal alignment film composition. A liquid crystal display device comprising a liquid crystal alignment film manufactured using the composition for liquid crystal alignment film of claim 8. The compound represented by the following formula (2), (3) or (4). [Formula 2]

, [Formula 3]

[Formula 4]

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