KR20090058994A - Polyimide polymer liquid crystal alignment material, method for fabricating liquid crystal alignment layer and liquid crystal display device using the same - Google Patents

Abstract

A polyimide-based photosensitive polymer liquid crystal aligning agent composition, a method for fabricating a liquid crystal alignment layer and a liquid crystal display device using the same are provided to resolve the problems concerning low thermal stability, low orientation force, and light stability. A polyimide-based photosensitive polymer liquid crystal aligning agent composition comprises a structure of chemical formula 1 which has at least one optically active group to a side chain and uses a triazine ring as a main chain; and a polyimide-based photosensitive polymer using a triazine ring having at least one optically active group. Any one of the active groups can pass through photolysis, others can pass through Fries rearrangement, and the others can pass through photo-dimerization, photo-isomerization or photoisomerization.

Description

Polyimide photosensitive polymer liquid crystal alignment agent composition having at least one photoactive group using a triazine ring, a method for producing a photosensitive polymer liquid crystal alignment layer using the same and a liquid crystal display device comprising the liquid crystal alignment layer (Polyimide polymer liquid crystal alignment material, Method for fabricating liquid crystal alignment layer and Liquid crystal display device using the same}

The present invention relates to a polyimide photosensitive polymer liquid crystal aligning agent composition having one or more photoactive groups using a triazine ring, a method of manufacturing a photosensitive polymer liquid crystal aligning film using the same, and a liquid crystal display device including the liquid crystal aligning film.

In the present specification, the photosensitive polymer liquid crystal aligning agent is used as a liquid crystal aligning agent of a device using optical properties of a liquid crystal, and in general, an alignment agent is coated on a substrate, and the surface is irradiated with ultraviolet light to form anisotropy on the surface. It means a combination of a material orienting materials and constituent materials thereof.

The liquid crystal display device using the photosensitive polymer liquid crystal aligning agent has various application fields such as a liquid crystal display (LCD), a compensation plate, and an optical component. It is described, but not limited to.

Liquid crystal display devices are leading the flat panel display market because they have the advantages of easy portability and low power consumption, and as they are gradually expanded to applications such as calculators and laptops, such as wall-mounted TVs and high definition TVs, High quality and wide viewing angles are required.

Generally, a liquid crystal display device is filled with an oriented liquid crystal between two glass substrates coated with an alignment layer, and a desired image is obtained by rearranging (switching) of liquid crystal molecules by an electric field applied from the outside. To form. At this time, in order to obtain uniform brightness and high contrast ratio, it is essential to orient the liquid crystal uniformly in a specific direction, and the degree of uniformity of this alignment is determined by the anchoring energy of the alignment layer.

At present, it is necessary to orient the liquid crystal, and the degree of uniformity of this alignment is determined by the anchoring energy of the alignment film.

Currently, as a method of aligning the liquid crystal, techniques such as a rubbing process and a non-rubbing process, such as a silicon oxide gradient deposition method and a photoalignment method, are known.

A method of aligning a liquid crystal by an existing rubbing method among the methods of aligning such liquid crystal will be described with reference to FIG. 1.

1 is a schematic view showing an alignment process of a liquid crystal alignment film by a rubbing method according to the prior art.

In the liquid crystal alignment method according to the related art, as shown in FIG. 1, an alignment film 13 is formed by coating a polymer compound such as polyimide on a substrate 11 by a printing method or the like, and the surface of the alignment film 13. It is rotated at high speed with a rubbing drum 31 wound with a fabric of nylon, polyester, and rayon fibers, and rubbed to form a very fine flaw on the surface of the polymer.

At this time, the liquid crystal molecules are oriented with a predetermined pretilt angle (θ) on the surface of the alignment agent while the rubbing process is performed. Such a rubbing method has been widely used industrially because the process is simple and the large area and the high speed treatment are possible.

However, since the shape of the microgrooves formed in the alignment layer 13 varies according to the friction strength between the alignment cloth and the alignment layer, the arrangement of liquid crystal molecules becomes nonuniform, resulting in phase distortion and light scattering. In addition, there is a problem that the acid yield is lowered due to damage of the substrate 11 due to electrostatic discharge (ESD) generated by rubbing the polymer surface and fine dust generated in the rubbing drum 21.

In addition, as one of the methods for achieving a wide viewing angle, an alignment film is coated to make a multi-domain display that widens the viewing angle by dividing one pixel into small pixels so that the liquid crystal alignment state of each divided pixel is changed. Complex lithographic processes such as rubbing, coating of photoresist, exposure and development, rubbing, removal of photoresist and the like are required and are undesirable in terms of productivity.

The silicon oxide gradient deposition method as a non-rubbing method is a method of depositing silicon oxide in a gradient direction with respect to the substrate 11, as shown in FIG. It is difficult to maintain uniformity of deposition angle and film thickness, and there is a problem that the process becomes large.

As such a non-rubbing method, the photo-alignment method inclines or vertically irradiates linearly polarized ultraviolet rays to a substrate coated with a photosensitive polymer, such as photo-dimerization or photo-isomerization. It is a method of inductively processing a non-contact process with respect to the orientation surface which induces anisotropy to a surface as a result.

The possibility of such a photoalignment method has been found using azobenzene compounds, and then various polymer compounds such as polymaleimide and polyolefin have been developed as photoalignment materials.

Polymers mainly used to date include, for example, a photosensitive ethene group, and chalcone, cinnamoyl, coumarin and the like are typical photosensitive portions. The orientation direction has a constant direction with respect to the polarization direction of the linearly polarized ultraviolet light, which is determined by the structure of the photosensitive polymer used.

In addition, the pretilt direction is changed by the incident direction of irradiated ultraviolet rays, and the pretilt angle is changed by the incident angle and irradiation energy.

Since the photo-alignment method is a non-contact method, problems due to the introduction of impurities and the generation of static electricity can be basically excluded, so that the cleanness is maintained and the alignment treatment is easy, improving the yield and suitable for mass production.

In addition, since a multi-domain can be formed by a relatively simple process of irradiating ultraviolet rays with different polarization directions depending on regions, it is an advantageous method for improving the viewing angle.

However, the conventional photo-alignment method does not uniformly align the liquid crystal due to the low photosensitivity of the photo-alignment material and its weak anisotropy, and has a problem in that fairness is deteriorated because a long irradiation time is required to solve this problem.

In addition, the physically coupled force between the photosensitive polymer liquid crystal aligning agent and the liquid crystal in which the anisotropy is formed is weak, unstable to light, and weak in orientation due to heat.

Therefore, for the practical use of the photo-alignment method, there have been demands for the improvement of the photochemical and thermal stability, the improvement of the electro-optic properties, and the problem of requiring a large amount of ultraviolet rays.

Accordingly, the present invention has been made to solve the above problems according to the prior art, an object of the present invention is at least one optical alignment material having excellent photochemical and thermal stability, good electro-optic properties and excellent alignment properties for the liquid crystal The present invention provides a polyimide or poly (imide-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having a photoactive group.

In addition, another object of the present invention to provide a method for producing a liquid crystal alignment film using the photosensitive polymer liquid crystal alignment agent composition.

Another object of the present invention is to provide a liquid crystal display device including the liquid crystal alignment layer.

In order to achieve the above object,

The present invention is a polymer having one or more photoactive groups in the side chain and including a triazine ring, consisting of the structure of Formula 1

One of the photoactive groups may undergo photolysis, the other may undergo a fleece photolocation shift, and the remaining sites may be photodimerized, photoisomerized or photocrosslinked to enhance, modify and preserve the resulting orientation. It provides a polyimide-based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group that can be subjected to oxidation.

For other purposes as above,

The present invention comprises the steps of dissolving a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group in an organic solvent; Applying the solution to the substrate by spin coating or printing to form an alignment layer; And obliquely irradiating and vertically irradiating ultraviolet rays linearly polarized using a polarizer on the surface of the alignment layer or unpolarized ultraviolet rays not using a polarizer.

In addition, the ultraviolet irradiation step preferably further comprises the step of forming a multi-domain using a photomask.

In order to achieve another object as described above,

The present invention provides a liquid crystal display device comprising a liquid crystal alignment film and a substrate using a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups.

In order to achieve another object as described above,

It has a structure of the following [Formula 1] having at least one photoactive group in the side chain and a triazine ring as a main chain,

[Formula 1]

One or more photoactive groups, characterized in that any one of the photoactive groups may undergo photolysis, the other may undergo a free fleece shift, and the remaining sites may undergo photodimerization, photoisomerization or photocrosslinking. Provided is a poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having a group.

Polyimide or poly (imide-urea) -based photosensitive polymer liquid crystal aligning composition using a triazine ring having at least one photoactive group according to the present invention, a method of manufacturing a liquid crystal alignment film using the same and a liquid crystal display device comprising the liquid crystal alignment layer According to the following effects.

In the present invention, unlike the photopolymer polymer alignment layer having a triazine derivative as a main chain of a polymer and having a side chain of a photoreactor such as a sanamate-based, coumarin-based, chalcone-based or maleimide-based photodegradable polyimide-based or poly (imide- Urea) photosensitive polymer liquid crystal aligning agent is prepared and used as an alignment layer, low thermal stability, which is a problem of the conventional photo alignment agent having a photopolymerizable polymer as a main chain, and low alignment force due to weak physical bonding force between the liquid crystal and the alignment layer. The problem of being affected by light stability in the cell manufacturing process can be overcome.

In addition, the present invention has a combination of high mechanical properties, heat resistance and the like, optical transparency, chemical resistance, and the like, which are characteristic of polyimide-based or poly (imide-urea) polymers, and are compatible with existing polyimide-based alignment agents. Therefore, the liquid crystal display devices manufactured using the polyimide photosensitive polymer liquid crystal aligning agent of the present invention can realize high quality and high quality display image quality.

Hereinafter, a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups according to an exemplary embodiment of the present invention, a method of manufacturing a liquid crystal alignment layer using the same, and a liquid crystal display device including the liquid crystal alignment layer It will be described in detail with reference to the accompanying drawings.

The polyimide-based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group according to the present invention has a structure of [Formula 1] having at least one photoactive group in a side chain and having a triazine ring as a main chain. ,

In Formula 1, R ₁ is composed of -XY, and X is one of the following formulas.

(Wherein m and n are each 0 to 10)

      In the above formula, Y is one selected from the following.

1, 2, 3, 4, 5, 6, 7, 8, and 9 are each one selected from the following.

Wherein m and n are each 0 to 10, and A and B are H, F, Cl, CN, CF ₃ , or CH ₃ to be.)

The imide bond connecting R ₂ and R ₃ in [Formula 1] is obtained by the reaction of an amine and an acid dianhydride, and the general form of the reaction is shown in the following [Scheme 1],

[Scheme 1]

R ₂ and R ₃ in Chemical Formula 1 Is attributable to the amine of [Scheme 1], each obtained from one selected from the following.

(Wherein m and n are each 0 to 10)

In addition, in the above [Reaction Scheme 1], R 'is attributed to an acid dianhydride, and each of them is obtained from one selected from the following. It is derived from the cyclobutane dianhydride (CBDA) in Figure 1 below, and similar structures can be obtained using the materials in Figure 2 plus CBDA.

Figure 2 is a schematic diagram showing the irradiation step of the alignment process of the liquid crystal alignment film using the photosensitive polymer liquid crystal alignment agent composition according to the present invention.

The method for producing a liquid crystal alignment film using a polyimide-based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group according to the present invention, first, a polyimide system using a triazine ring having at least one photoactive group. The photosensitive polymer liquid crystal aligning agent composition was selected from colobenzene, N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N, N-dimethylimidazolidinone (DMI), and N, N-dipropyl. Imidazolidinone (DPI), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), cyclopentanone, cyclohexanone, dichloroethane, butylcellulsolve, gammabutyrolactone and tetra It is dissolved in an organic solvent consisting of any one or at least any two or more mixed solvents selected from the group consisting of hydrofuran (THF) at a concentration of 1 to 20 wt% to a viscosity of 1 to 1000 cps.

The concentration of the solvent depends on the molecular weight, and if the viscosity is less than 1 wt% and more than 20 wt%, the desired viscosity and thickness cannot be obtained, and if the viscosity is less than 1 cps and 1000 cps, the desired thickness cannot be obtained.

Next, the solution is applied to a substrate 101, for example, an ITO glass substrate, by a spin coating or printing method with a thickness of 50 to 100 nm to form an alignment layer 103.

If less than 50 nm and more than 100 nm, it is difficult to be applied to the liquid crystal display device.

The surface of the alignment layer 103 is inclined or vertically irradiated with the ultraviolet ray 121 linearly polarized using the polarizer or the unpolarized ultraviolet ray 121 without the polarizer for 2 seconds to 10 minutes, thereby forming the image on the substrate 101. The liquid crystal aligning film 103 is formed in this.

In this case, it is preferable to form a multi-domain by using a photomask in the ultraviolet irradiation process.

The irradiation time depends on the power of the lamp. The larger the power, the shorter the irradiation time, and the smaller the power, the larger the irradiation time. For lamps of approximately 20 mW, incline or level irradiation for 2 seconds to 10 minutes. If less than 2 seconds or more than 10 minutes, the desired orientation may not be obtained.

As shown in Figure 2, the polyimide-based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group according to the present invention is a pretilt angle of the liquid crystal oriented in accordance with the inclination angle of the ultraviolet rays 121 for oblique irradiation The angle of change may be varied, and the pretilt angle may be set to 0 ° by changing the chemical structure or the ultraviolet ray 121.

Therefore, a driving mode of a liquid crystal display device manufactured using a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups according to the present invention is STN (Super Twisted Nematic), TN (Twisted Nematic) It can be applied to various modes such as In Plane Switching (IPS) and Vertically Alligned Twisted Nematic (VATN) mode.

The liquid crystal display device including the liquid crystal alignment layer 103 using the polyimide photosensitive polymer liquid crystal alignment agent composition using a triazine ring having one or more photoactive groups according to the present invention is a liquid crystal prepared on the substrate 101 as described above. Liquid crystal alignment is imparted by the alignment film 103.

If the liquid crystal display device manufacturing method according to the invention of the liquid crystal display device will be described.

As described above, after spraying a spacer having a predetermined size on the photoreacted two substrates 101 having the liquid crystal alignment film 103, and attaching the cell between the two substrates 101 with a certain thickness using an adhesive. After the curing process for about 1 hour at about 130 ℃ and the adhesive to cure the two substrates are completely bonded to prepare a cell.

Thereafter, the liquid crystal is injected into the cell, heat is applied at 100 to 130 ° C. for about 1 hour, and a heat treatment step of lowering the temperature to room temperature is performed once. At this time, the heat treatment is to crystallize the liquid crystal, it is crystallized only when heated to 100 ℃ or more, it is heated to 130 ℃ clearing temperature (clearing temperature).

Hereinafter, a preferred embodiment of the present invention will be described in more detail below.

However, the present invention is not limited to the following examples and various forms of embodiments can be implemented within the appended claims, and only the following examples are used in the art to make the disclosure of the present invention complete. It is intended to facilitate the practice of the invention to those skilled in the art.

Example 1

Embodiment 1 relates to a polyimide photosensitive polymer liquid crystal alignment agent having a photosensitive functional group, a liquid crystal alignment film manufacturing method using the same, and a liquid crystal display device manufacturing method including the liquid crystal alignment film.

(1) Introduction of phenyl group

15.7 g of phenylbolamide was placed in a round-bottomed flask filled with nitrogen and dissolved in 150 ml of tetrahydrofuran from which moisture was removed. 5 g of magnesium was added to the solution to prepare a Grignard reagent.

After dissolving 18.4 g of triazine in 200 ml of dehydrogenated tetrahydrofuran, the Grignard reagent prepared above was transferred to the dropping funnel by using a double tip needle. After setting the environment at -20 ° C, the Grignard reagent was slowly added dropwise to the triazine solution for 6 hours to prepare triazine substituted with one phenyl group.

Purification was carried out to remove the remaining Grignard reagent in 1 ml of methanol in the reaction solution, distilled off tetrahydrofuran, dissolved in methylene chloride and passed through a filter paper to remove salts. In a separatory funnel, a solution of the reactant and 0.1 N aqueous sodium hydroxide solution were added and mixed to remove a small amount of salt, and only a methylene chloride solution was removed to remove a solvent and recrystallized from normal hexane to obtain a reaction product.

(2) Synthesis of Triazine Monomer Having Two Amine Functions

22.6 g of 2-phenyl-4,6-dichloro-1,3,5-triazine obtained by the method of Example 1 (1) was placed in a round bottom flask and dissolved in 300 ml of chloroform. 32.8 g of 4-aminophenol and 12 g of sodium hydroxide were dissolved in 300 ml of distilled water dissolved in 3 g of cetyltrimethylammonium bromide, mixed with the previous triazine solution, and reacted vigorously for 24 hours.

After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloroide. The water-removed solution was distilled under reduced pressure to remove chloroform, an organic solvent, and then recrystallized from a mixed solvent of methylene chloride and normal hexane. The precipitated crystals were filtered under reduced pressure and dried in vacuo to obtain a triazine monomer.

(3) Polymerization of polyimide photosensitive polymer liquid crystal aligning agent

37.139 g of the triazine monomer obtained by the method of Example 1 (2) was placed in a round bottom flask filled with nitrogen and dissolved in 300 ml of N-methylpyrrolidone. After dissolving 19.611 g of cyclobutanetetracarboxylic dianhydride in 100 ml of N-methylpyrrolidone, the mixture was stirred vigorously while slowly dropping into the solution in which the previous triazine monomer was dissolved, and allowed to react for 24 hours. Using a triazine ring, a polyamic acid, which is a preliminary material of a polyimide polymer liquid crystal aligning agent having a cinnamate photosensitive functional group, was synthesized.

(4) Fabrication of liquid crystal display device

The obtained photo-alignment agent was dissolved in a mixed solvent of NMP and butyl cellussolve at a concentration of 6wt%, and the solution was passed through a filtration membrane having a micropore size of 0.1 μm to remove undissolved impurity particles. The solution is printed on a glass substrate coated with a transparent electrode with a thickness of 50 to 500 nm to apply a photoalignment agent, and the glass substrate is dried at 150 to 250 ° C. for about 1 to 2 hours to remove the solvent and imidization reaction. Was done. The glass substrate was used to induce a complex photoreaction such as photolysis of polymer chains to ultraviolet light of a 4mW / cm ² (@ 254nm) mercury lamp to prepare a polymer liquid crystal alignment film. The alignment film induced by anisotropy by UV irradiation was further baked at 100 to 250 ° C. for 0.5 to 2 hours to complete the alignment film. The properties of the alignment film and the properties of the liquid crystal cell were measured and the results are shown in the following table in comparison with the existing alignment films.

Here, Comparative Example 1 is an R / B alignment film, Comparative Example 2 is a photopolymerization type UV alignment film, and Example 1 is a photolysis type UV alignment film.

Meanwhile, a poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups according to another embodiment of the present invention, and a liquid crystal aligning film using the same A manufacturing method and a liquid crystal display device including the liquid crystal alignment layer will be described in detail with reference to the accompanying drawings.

Poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups according to the present invention has one or more photoactive groups in the side chain and has a triazine ring Consists of the structure of the following [Formula 1] to the main chain,

[Formula 1]

R1 in [Formula 1] is composed of -X-Y or [Formula 2], X is one of the following formula,

(Wherein m and n are each 0 to 10)

      In the above formula, Y is one selected from the following.

1, 2, 3, 4, 5, 6, 7, 8, and 9 are each one selected from the following.

Wherein m and n are each 0 to 10, and A and B are H, F, Cl, CN, CF ₃ , or CH ₃ to be.)

[Formula 2] has the following structure, in the following [Formula 2] Y is one selected from the following.

(Where n is 0 to 10)

In the formula (4a), 1 and 2 are each one selected from the following.

Where A is H, F, CH ₃ , CF ₃ or CN.

The imide bond connecting R ₂ , R _{3 , and} R ₄ in [Formula 1] is obtained by the reaction of an amine and an acid dianhydride, and the general form of the reaction is shown in the following [Scheme 1],

[Scheme 1]

In Formula 1, R ₂ , R ₃ , The urea bond connecting R ₅ is formed by the reaction of an isocyanate and an amine, and the reaction is shown in [Scheme 2]. Here, the isocyanate may again react with the urea bond to form a non-uret bond, and the reaction is shown in [Scheme 3].

Although the polyurea of the present invention has a urea bond and a non-uret bond together, only the urea bond is shown in [Formula 1] showing a general structure. Therefore, it should not be concluded that the polyurea of the present invention is free of non-uret bonds.

Therefore, the amide bond and the urea bond, which are the linking moieties of [Formula 1], are obtained by the reaction of amine, carboxylic acid, and isocyanate, and are mainly composed of a reaction of reaction of Scheme 1 and Scheme 2.

R ₂ and R ₃ in the above [Formula 1] are due to the amines of [Scheme 1] and [Scheme 2] is one selected from the following.

(Where m and n are each 0 to 10)

And, in [Formula 1] R ₄ is due to the acid dianhydride of [Scheme 1] is each one selected from the following.

In addition, in [Formula 1], R ₅ is due to the isocyanate of [Scheme 2] is one selected from the following.

Where 1, 2, 3, 4, 5, 6, 7, 8 are H, F, Cl, CN, CF ₃ , (CH ₂ ) _n CH ₃ , O (CH ₂ ) _n CH ₃ , and A and B is also H, F, Cl, CN, CF ₃ , (CH ₂ ) _n CH ₃ , O (CH ₂ ) _n CH _3, respectively. N is 0 to 10.

In addition, the benzene ring included in the photosensitive polymer of Formula 1 has an ortho- or meta- structure in addition to the para- structure, or a mixture of ortho-, meta- and para. It may have a structure.

 Example 2

Embodiment 2 relates to a poly (imide-co-urea) -based photosensitive polymer liquid crystal alignment agent having a maleimide side chain, a liquid crystal alignment film manufacturing method using the same, and a liquid crystal display device manufacturing method including the liquid crystal alignment film.

(1) Preparation of N-hydroxymaleimide

42.26 g of N- (phenyloxycarbonyloxy) maleimide (II) is taken, dissolved in 500 ml of methanol and refluxed for 3 hours. After the reaction, methanol was evaporated to remove the residue, and the remaining liquid was poured into benzene to obtain a solid. This solid was recrystallized using a mixed solvent of tetrahydrofuran (THF) and hexane to give 12.60 g of N-hydroxymaleimide in a yield of 62%. The crystal melting point was measured at 125 ° C., consistent with the values reported in 125-126 ° C. (Akiyama, M., et al., J. Chem. Soc., Perkin 1 1980, 2122).

(2) Preparation of triazine substituted with maleimide

11.3 g of N-hydroxymaleimide was dissolved in 100 ml of THF. Here, after adding NaH 3g, the reaction was carried out for 2 hours, and the reaction solution was slowly added dropwise at -20 ° C to a solution of 18.4 g of triazine dissolved in THF. Proceeded. The THF was removed from the solution after the reaction was completed, the salt component was removed from the solid reaction product, and recrystallized from a mixed solution of methylene chloride and normal hexane to prepare a triazine compound substituted with maleimide. The yield was 15.7 g as 60%. .

(3) Preparation of Triazine Monomer

Dissolve 26.1 g of the maleimide-substituted triazine compound in 200 ml of chloroform, dissolve 32.8 g of 4-aminophenol and 12 g of sodium hydroxide in 300 ml of distilled water dissolved in 3 g of cetyltrimethylammonium bromide, and mix with triazine solution to reflux. The reaction was carried out for 24 hours. After completion of the reaction, the organic solution phase was separated, transferred to a separatory funnel, washed three times with distilled water to extract impurities, and then water was removed with calcium chloroide. The water-removed solution was distilled under reduced pressure to remove chloroform, an organic solvent, and then recrystallized from a mixed solvent of THF and normal hexane. The precipitated crystals were filtered under reduced pressure and dried in vacuo to obtain a triazine monomer. The yield was 25.8g as 64% of yield.

(4) Polymerization of Poly (imide-co-urea) with Maleimide Side Chain

40.24 g of the triazine monomer prepared above is placed in a round bottom flask filled with nitrogen and dissolved in 300 ml of N-methylpyrrolidone. A solution in which 8.71 g of toluene diisocyanate was dissolved in 80 ml of N-methylpyrrolidone and 10.9 g of 1,2,4,5-benzenetetracarboxylic dianhydride in 100 ml of N-methylpyrrolidone were dissolved in this solution. The reaction was carried out for 6 hours with each dropwise added to prepare a poly (imide-co-urea) copolymer.

(5) Fabrication of liquid crystal display device

The obtained photo-alignment agent was dissolved in a mixed solvent of NMP and butyl cellussolve at a concentration of 6wt%, and the solution was passed through a filtration membrane having a micropore size of 0.1 μm to remove undissolved impurity particles. The solution is printed on a glass substrate coated with a transparent electrode with a thickness of 50 to 500 nm to apply a photoalignment agent, and the glass substrate is dried at 150 to 250 ° C. for about 1 to 2 hours to remove the solvent and imidization reaction. Was done. The glass substrate was used to induce a complex photoreaction such as photolysis of polymer chains to ultraviolet light of a 4mW / cm ² (@ 254nm) mercury lamp to prepare a polymer liquid crystal alignment film. The alignment film induced by anisotropy by UV irradiation was further baked at 100 to 250 ° C. for 0.5 to 2 hours to complete the alignment film. The properties of the alignment film and the properties of the liquid crystal cell were measured and the results are shown in comparison with the conventional alignment film in the following table.

Here, Comparative Example 1 is an R / B alignment film, Comparative Example 2 is a photopolymerization type UV alignment film, and Example 2 is a photolysis type UV alignment film.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

Accordingly, the scope of the present invention is not limited thereto, but various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims are also within the scope of the present invention.

1 is a schematic view showing an alignment process of a liquid crystal alignment film by a rubbing method according to the prior art.

Figure 2 is a schematic diagram showing the irradiation step of the alignment process of the liquid crystal alignment film using the photosensitive polymer liquid crystal alignment agent composition according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

101: substrate 103: alignment film

121: UV

Claims (35)

It has a structure of the following [Formula 1] having at least one photoactive group in the side chain and a triazine ring as a main chain,

One or more photoactive groups, characterized in that any one of the photoactive groups may undergo photolysis, the other may undergo a free fleece shift, and the remaining sites may undergo photodimerization, photoisomerization or photocrosslinking. Polyimide-type photosensitive polymer liquid crystal aligning agent composition using the triazine ring which has a group. The method of claim 1, R1 of [Formula 1] is composed of -X-Y, X is a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups, characterized in that one of the following formula.

(Wherein m and n are each 0 to 10) The method of claim 2, Wherein Y is one selected from the following: polyimide photosensitive polymer liquid crystal aligning agent composition using triazine ring having at least one photoactive group.

Wherein 1, 2, 3, 4, 5, 6, 7, 8, and 9 are each one selected from

Wherein m and n are each 0 to 10, and A and B are H, F, Cl, CN, CF ₃ , or CH ₃ to be.) The method of claim 1, The imide bond connecting R ₂ and R ₃ in [Formula 1] is obtained by the reaction of an amine and an acid dianhydride, and the general form of the reaction is represented by the following [Scheme 1]. The polyimide type photosensitive polymer liquid crystal aligning agent composition using the triazine ring which has. [Scheme 1]

The method of claim 4, wherein R ₂ and R ₃ in Chemical Formula 1 Is a polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group, each of which is derived from an amine of [Scheme 1].

(Wherein m and n are each 0 to 10) The method of claim 5, R 'in [Scheme 1] is due to an acid dianhydride, each obtained from one selected from the following, which is derived from cyclobutane dianhydride (CBDA) of Figure 1 below, and CBDA and other materials of Figure 2 Polyimide-based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group, characterized in that to obtain a similar structure using.

According to claim 1, wherein the benzene ring contained in the photosensitive polymer of [Chemical Formula 1] comprises an ortho- or meta-structure or a mixed structure of two or more of the ortho-, meta-, para- structure A polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group. The method of claim 1, wherein the first step (S1) of dissolving the polyimide photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group in an organic solvent; A second step (S2) of forming the alignment layer by applying the solution onto the substrate by spin coating or printing; And And a third step (S3) of obliquely or vertically irradiating ultraviolet rays linearly polarized using a polarizer on the surface of the alignment layer or non-polarized ultraviolet rays not using the polarizers (S3). . The method of claim 8, wherein the concentration of the organic solvent in the first step (S1) is 1 to 20 wt%, the viscosity is 1 to 1000 cps method of producing a photosensitive polymer liquid crystal alignment film. The method of claim 8, wherein the concentration of the organic solvent in the first step (S1) is 1 to 20 wt%, the viscosity is 1 to 1000 cps method of producing a photosensitive polymer liquid crystal alignment film. 9. The method of claim 8, wherein the thickness of the alignment layer applied on the substrate in the second step (S2) is 50 to 100 nm. The method of claim 8, The organic solvent is colobenzene, N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N, N-dimethylimidazolidinone (DMI), N, N-dipropylimidazoli Dinon (DPI), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), cyclopentanone, cyclohexanone, dichloroethane, butylcellulsolve, gammabutyrolactone and tetrahydrofuran ( THF) any one or at least two or more mixed solvents selected from the group consisting of a method for producing a photosensitive polymer liquid crystal alignment film. The method of claim 8, wherein the third step (S3) further comprises forming a multi-domain by using a photomask during ultraviolet irradiation. 10. A liquid crystal display device comprising a liquid crystal alignment film and a substrate manufactured by claim 8. The method of claim 14, The liquid crystal display device is used in one of a liquid crystal display (liquid crystal display), a compensator (compensator), an optical component. The liquid crystal display device of claim 15, wherein the liquid crystal display device is configured to drive one of a super twisted nematic (STN), twisted nematic (TN), in plane switch (IPS), vertical alignment (VA), and vertically aligned twisted nematic (VATN). It has a liquid crystal display element characterized by the above-mentioned. It has a structure of the following [Formula 1] having at least one photoactive group in the side chain and a triazine ring as a main chain, [Formula 1]

One or more photoactive groups, characterized in that any one of the photoactive groups may undergo photolysis, the other may undergo a free fleece shift, and the remaining sites may undergo photodimerization, photoisomerization or photocrosslinking. Poly (imide-co-urea) type photosensitive polymer liquid crystal aligning agent composition using the triazine ring which has a group. The method of claim 17, In Formula [1], R1 is composed of -XY or Formula 2, and X is a poly (imide-co-urea) system using a triazine ring having one or more photoactive groups, wherein X is one of the following formulas. Photosensitive polymer liquid crystal aligning agent composition.

(Wherein m and n are each 0 to 10)

The method of claim 18, Wherein Y is one selected from the following: poly (imide-co-urea) photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups.

Wherein 1, 2, 3, 4, 5, 6, 7, 8, and 9 are each one selected from

Wherein m and n are each 0 to 10, and A and B are H, F, Cl, CN, CF ₃ , or CH ₃ to be.) The method of claim 18, In Formula 2, Y is a poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having one or more photoactive groups, wherein one is selected from the following.

The method of claim 17, The imide bond connecting R ₂ , R ₃ , and R ₄ in [Formula 1] is obtained by the reaction of an amine and an acid dianhydride, and the general form of the reaction is represented by the following [Scheme 1]. Poly (imide-co-urea) type photosensitive polymer liquid crystal aligning agent composition using the triazine ring which has a photoactive group. [Scheme 1]

The method of claim 17, In Formula 1, R ₂ , R ₃ , The urea bond connecting R ₅ is formed by the reaction of an isocyanate with an amine, and the reaction is shown in [Scheme 2], and the isocyanate reacts with the urea bond again to form a non-uret bond as shown in [Scheme 3]. A poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using a triazine ring having at least one photoactive group.

The method of claim 22, The amide bond and the urea bond, which are the linking moieties of [Formula 1], are obtained by the reaction of amine, carboxylic acid, and isocyanate. Poly (imide-co-urea) type photosensitive polymer liquid crystal aligning agent composition. The method of claim 22, In Formula [1], R ₂ , R ₃ are attributable to the amines of [Scheme 1] and [Scheme 2], each of which is selected from the following poly (3) using a triazine ring having one or more photoactive groups Imide-co-urea) type photosensitive polymer liquid crystal aligning agent composition.

(Where m and n are each 0 to 10) The method of claim 21, R ₄ in [Formula 1] is due to the acid dianhydride of [Scheme 1] is a poly (imide-co-urea) using a triazine ring having at least one photoactive group, characterized in that each one selected from the following System photosensitive polymer liquid crystal aligning agent composition.

The method of claim 22, In Formula [1], R ₅ is due to the isocyanate of [Scheme 2], each of which is a poly (imide-co-urea) system using a triazine ring having at least one photoactive group Photosensitive polymer liquid crystal aligning agent composition.

Where 1, 2, 3, 4, 5, 6, 7, 8 are H, F, Cl, CN, CF ₃ , (CH ₂ ) _n CH ₃ , O (CH ₂ ) _n CH ₃ , and A and B is also H, F, Cl, CN, CF 3 , _{respectively, (CH 2) n CH 3} , O (CH 2) and _n CH _{3, n} is 0 to 10. 18. The method of claim 17, wherein the benzene ring contained in the photosensitive polymer of [Formula 1] Trees with one or more photoactive groups characterized by having an ortho- or meta- structure in addition to the para- structure, or a mixture of ortho-, meta- and para structures Poly (imide-co-urea) type photosensitive polymer liquid crystal aligning agent composition using a azine ring. 18. The method of claim 17, further comprising: dissolving the poly (imide-co-urea) -based photosensitive polymer liquid crystal aligning agent composition using the triazine ring having at least one photoactive group in an organic solvent; A second step (S2) of forming the alignment layer by applying the solution onto the substrate by spin coating or printing; And And a third step (S3) of obliquely or vertically irradiating ultraviolet rays linearly polarized using a polarizer on the surface of the alignment layer or unpolarized ultraviolet rays not using a polarizer. . 29. The method of claim 28, wherein the concentration of the organic solvent in the first step S1 is 1-20 wt%, and the viscosity is 1-1000 cps. 29. The method of claim 28, wherein the concentration of the organic solvent in the first step S1 is 1-20 wt%, and the viscosity is 1-1000 cps. 29. The method of claim 28, wherein the thickness of the alignment layer applied on the substrate in the second step (S2) is 50 to 500 nm. The method of claim 28, 29. The method of claim 28, wherein the third step (S3) further comprises forming a multi-domain using a photomask during ultraviolet irradiation. A liquid crystal display device comprising a liquid crystal alignment film and a substrate manufactured by claim 28. The method of claim 33, wherein The liquid crystal display device is used in one of a liquid crystal display (liquid crystal display), a compensator (compensator), an optical component. The liquid crystal display device of claim 34, wherein the liquid crystal display device is configured to drive one of a super twisted nematic (STN), twisted nematic (TN), in plane switch (IPS), vertical alignment (VA), and vertically aligned twisted nematic (VATN). It has a liquid crystal display element characterized by the above-mentioned.

Images