KR100792939B1 - Composition for photoinduced liquid crystal alignment comprising silica, the film for photoinduced liquid crystal alignment thereby, manufacturing method of the same and the liguid crystal cell comprising the film - Google Patents

Abstract

In this invention, the liquid crystal aligning agent composition characterized by including a silica in a liquid crystal aligning agent composition is disclosed. And it is preferable that the said silica is 500 nm or less in diameter, and the mixing ratio with respect to a liquid crystal aligning agent composition is 0.001-5 wt%. The present invention improves the problem of adjusting the pretilt angle of the existing alignment agent, thereby improving the electro-optic characteristics, and in particular, there is no problem of deteriorating the characteristics of the liquid crystal device, and one alignment layer can be appropriately adjusted according to the driving mode. As a result, the fixed compatibility is improved.

Silica, liquid crystal, alignment agent, alignment film, liquid crystal element, pretilt angle, electro-optical characteristics

Description

A liquid crystal aligning composition comprising silica, a liquid crystal aligning film using the same, a method for manufacturing the same, and a liquid crystal device comprising the liquid crystal aligning film TECHNICAL FIELD AND THE LIGUID CRYSTAL CELL COMPRISING THE FILM}

1 is a schematic view showing an alignment step of a liquid crystal alignment film by a conventional rubbing method,

FIG. 2A is a schematic diagram illustrating a method of driving a TN mode liquid crystal device, the case in which no electric field is applied; FIG.

FIG. 2B is a schematic view showing a method of driving a TN mode liquid crystal device, the case in which an electric field is applied; FIG.

Figure 3 is a schematic diagram showing the irradiation step of the alignment process of the liquid crystal alignment film using the photosensitive polymer liquid crystal aligning agent composition according to an embodiment of the present invention.

* A brief description of the major reference marks *

10: photo-alignment film 20: substrate

70: polarizer 71: analyzer

72: electrode 73: voltage applied electrode

80: ultraviolet rays

The present invention relates to a liquid crystal aligning agent composition containing silica, a liquid crystal aligning film using the same, a method for producing the same, and a liquid crystal device including the liquid crystal aligning film.

The photosensitive polymer liquid crystal aligning agent of the present invention is used as a liquid crystal aligning agent of a device using optical properties. In general, a liquid crystal is oriented by applying an alignment agent on a substrate and irradiating ultraviolet light to the surface to form anisotropy on the surface thereof. Combinations and their constituent materials.

The liquid crystal device of the present invention is applied to various fields such as a liquid crystal display (LCD), a compensator and an optical part. In the present invention, in particular, the application to the liquid crystal display device (LCD) is mainly described, but is not limited thereto, and all applications within the scope encompassing the technical idea of the present invention are included.

The liquid crystal display device is leading the flat panel display market because it has the advantages of easy portability and low power consumption. As the usage is gradually expanded to applications such as calculator notebooks and wall-mounted TVs and high-definition TVs, high-definition, high-quality and optical Viewing angle is required.

Such liquid crystal display devices are generally filled with liquid crystals oriented between two glass substrates coated with an alignment layer, and rearrangement (switching) of liquid crystal molecules occurs by an externally applied electric field to form a desired image. In this case, in order to obtain uniform brightness and high contrast ratio, it is essential to orient the liquid crystal uniformly in a specific direction.

Currently, rubbing process and non-rubbing process, such as silicon oxide oblique deposition method, liquid crystal alignment induction method using ion beam, photo-alignment method and the like are known as a method of orienting the liquid crystal.

1 is a schematic view showing an alignment step of a liquid crystal alignment film by a conventional rubbing method.

In the rubbing method, as shown in FIG. 1, the rubbing drum 7 which apply | coated high molecular compounds, such as a polyimide, to the board | substrate 2 by the printing method etc., and wound the cloth which planted this surface into the nylon and polyester rayon fiber. It is a method of forming a very fine groove on the surface of the polymer by rubbing by rotating at a high speed.

While the rubbing process is carried out, the liquid crystal molecules are aligned with a constant pretilt angle (θ) on the surface of the alignment agent. This rubbing method is widely used industrially because the process is simple, large-area and high-speed treatment is possible.

However, the shape of the microgrooves formed in the alignment layer varies according to the friction strength between the alignment cloth and the alignment layer, resulting in non-uniform arrangement of liquid crystal molecules, resulting in phase distortion and light scattering. In addition, there is a problem in that the production yield is reduced by damage to the substrate 2 due to electrostatic discharge (ESD) generated by rubbing the polymer surface and fine dust generated in the rubbing drum 7.

In addition, in order to make a multi-domain display that widens the viewing angle by dividing one pixel into small pixels and changing the liquid crystal alignment state of each divided pixel, the alignment film coating, rubbing, coating of photoresist and exposure ( Complex lithographic processes such as exposure and development, rubbing, removal of photoresist, etc. are required, which is undesirable in terms of productivity.

On the other hand, as the non-rubbing method, the silicon oxide oblique direction deposition method is a method of depositing silicon oxide in an oblique direction with respect to a substrate, and it is difficult to maintain uniformity of deposition angle and film thickness with respect to the substrate, and the process is large in scale. There is a problem.

As a non-rubbing method, the photo-alignment method inclines or vertically irradiates linearly polarized ultraviolet light onto a substrate coated with a photosensitive polymer, and induces photo-dimerization or photo-isomerization. As a result, it is a method of non-contact treatment with respect to the orientation surface which forms anisotropy in a surface.

The possibility of this photoalignment method has been found using azobenzene compounds (K. lchimura et al., Langmuir, 4, 1214, 1988), followed by polymaleimide (HJChoi et al., US Patent 6218501), polyolefins (RH). Herr et al. US Patent 6201087) have been developed as photo-alignment materials.

In the photoalignment method using the liquid crystal aligning agent, the liquid crystal aligning agent has a certain 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 varies with the incident direction of irradiated ultraviolet rays, and the pretilt angle varies with the irradiation energy and the incident angle. As the polymer mainly used up to now, for example, there are some containing an ethene group having a photosensitive property. Examples of the photosensitive portion include chalcone, cinnamoyl, and coumarin.

A method of inducing liquid crystal alignment by using an ion beam as a non-rubbing method is a method of inducing liquid crystal alignment by applying an ion beam after applying a polymer aligning agent. An ion beam is an electromagnetic beam of gas molecules such as argon, helium, oxygen, and nitrogen. Method For example, it refers to a flow state of ions that are energized by applying an electron gun or ionizing using RF electromagnetic waves and applying a voltage of 100 to 3000 eV.

When the ion beam having the energy is irradiated on the surface of the polymer material, the surface atoms are scraped off and redeposited to form characteristic surface curvatures for each polymer. Surface curvature varies in shape and size depending on the type of ions to be irradiated, the energy, the amount of radiation, and the type of polymer, and ranges from a few nanometers to hundreds of micrometers. When the surface is curved has a certain direction, which acts as a micro groove by rubbing.

Since the liquid crystal alignment induction method using the optical alignment method or the ion beam is a non-contact method, problems due to the introduction of impurities and the generation of static electricity can be basically eliminated. Therefore, the cleanliness is maintained and the alignment process is easy to improve the yield and is suitable for mass production. It has advantages

In the case of the photo-alignment method, since the multi-domain can be formed by a relatively simple process of irradiating ultraviolet rays with different polarization directions depending on the region using the photomask, it is advantageous to improve the viewing angle.

However, the photo-alignment method or the method using the ion beam has a weak physical bonding force between the liquid crystal aligning agent formed with anisotropy and the liquid crystal, poor thermal mechanical stability such as weakening of the alignment due to heat, and satisfactory electro-optic properties. There is a limit to this.

In particular, the electro-optic properties of the liquid crystal aligning agent are greatly influenced by the response speed according to the pretilt angle and driving mode of the liquid crystal, such as STN (Super Twisted Nematic), TN (Twisted Nematic), IPS (In Plane Switching), and VATN (Vertically Alligned). In the various driving methods such as twisted nematic mode, the optimum pretilt angle is a method for maximizing the performance of the liquid crystal device. However, it is very difficult to make the pretilt angle have the optimal angle. At the moment, the problem is that you can't adjust the pretilt angle.

2A and 2B are schematic views showing a method of driving a TN mode liquid crystal device.

As shown in FIGS. 2A and 2B, electrodes 72 and 73 are interposed between polarizer 70 and analyzer 71, and as shown in FIG. 2A, no voltage is applied to electrode 72. Therefore, before the electric field is formed (E = 0), the liquid crystal and the alignment layer are arranged at an appropriate pretilt angle. However, as shown in FIG. 2B, when an electric field is formed by applying a voltage to the electrode 73 (E) Are arranged in the direction of the electric field.

Therefore, the higher the pretilt angle, the smaller the moving range of the liquid crystal when the electric field is applied or removed, thereby increasing the response speed.However, the pretilt angle of the liquid crystal cannot be infinitely large. In connection with the present invention, there is a limit value and an optimum value of the pretilt angle, and it is very difficult to adjust the optimum value.

In order to solve such a pretilt angle control problem, there have been conventional methods of changing the chemical structure or adjusting the irradiation angle and time in the light irradiation process.

However, there is a problem that the method of changing the chemical structure of the alignment agent requires a lot of time and effort, and also there is a problem in that it is not possible to predict whether or not the pretilt angle changes according to the changed chemical structure.

In addition, the method of changing the irradiation angle and time in the light irradiation process has a problem that the change range of the pretilt angle is extremely small.

Thus, there has been a demand for a method for optimizing the change range while easily adjusting the pretilt angle within a relatively fast time.

On the other hand, in the related art liquid crystal device, a technique for removing afterimages by removing ionic impurities by mixing silica in the liquid crystal rather than the alignment agent or the alignment film has been proposed.

However, this method merely suggests that the silica is mixed with the liquid crystal to remove the ionic impurities, so that the adjustment of the pretilt angle does not provide the effect of improving the electro-optic characteristics, but rather the liquid crystal interposed between the alignment layers. There is a problem that the characteristics of the liquid crystal device are inhibited by the silica to be mixed.

Therefore, the present invention has been made to solve the above problems,

An object of the present invention is a liquid crystal comprising a silica that is not mixed with the liquid crystal, but by the alignment agent, there is no degradation of the characteristics of the liquid crystal device, and at the same time can easily adjust the pretilt angle to improve the electro-optic properties It is to provide an alignment agent composition.

Another object of the present invention is to provide a liquid crystal alignment film in which electro-optic properties are improved as the pretilt angle can be adjusted using the liquid crystal alignment agent composition.

Another object of the present invention is to provide a method for producing a liquid crystal alignment film using the liquid crystal aligning agent composition.

Still another object of the present invention is to provide a liquid crystal device comprising the liquid crystal alignment film.

The above object of the present invention is achieved by a liquid crystal aligning agent composition containing silica in the liquid crystal aligning agent composition.

And the said liquid crystal aligning agent composition is a polyisocyanurate type polymer; Polyimide-based polymers; Polyamide-based polymers; Polyester-based polymer; Polyether polymers; Polythioether polymers; Polyurethane-based polymers; Poly (amide-imide) based polymers; Poly (amide-ester) -based polymers; Poly (ether-thioether) -based polymers; Poly (imide-urethane) -based polymers; Poly (amide-urethane) -based polymers; Acrylic polymers including polymethyl methacrylate; Polyolefin-based polymers including polyethylene and polypropylene series; Polystyrene-based polymers; Polyacetal polymers; Phenolic polymers; Epoxide-based polymers; And it is preferable to use at least one polymer selected from the group consisting of polysiloxane-based polymer, wherein the polymer is light of cinnamate, chalcone, azo compound, imide, cinnamildene malonate or styryl acrylate It is preferable to include the reactor in the main chain or the side chain.

Moreover, it is preferable that the said silica is 500 nm or less in diameter, and the mixing ratio with respect to a liquid crystal aligning agent composition is 0.001-5 wt%.

The other object of this invention as mentioned above is achieved by the liquid crystal aligning film 10 containing the said liquid crystal aligning agent composition.

Another object of the present invention as described above, the step of dissolving the liquid crystal aligning agent composition in an organic solvent (S1); Mixing silica in the solution (S2); Applying the solution onto the substrate (2) by spin coating or printing to form an alignment layer (S3); And aligning the liquid crystal by inclining or vertically irradiating the ultraviolet ray 80 linearly polarized using the polarizer on the surface of the alignment layer 10 or the unpolarized ultraviolet ray 80 not using the polarizer (S4). It is achieved by the manufacturing method of the liquid crystal aligning film 10 containing.

Another object as described above is achieved by a liquid crystal device comprising a liquid crystal alignment film 1 using a liquid crystal aligning agent composition containing silica in a liquid crystal device.

Hereinafter, the liquid crystal aligning agent composition containing silica which concerns on this invention, the liquid crystal aligning film using the same, the manufacturing method, and the liquid crystal element containing the said liquid crystal aligning film are demonstrated in detail.

In the present invention, in order to control the pretilt angle by adjusting the interaction between the alignment film and the liquid crystal used for the purpose of liquid crystal alignment, in response to the change of the pretilt angle, an alignment agent composition other than the liquid crystal, for example, triazine, acrylic, It is based on the technical idea of containing a predetermined amount of silica in the liquid crystal aligning agent of polymers, such as a polyolefin type, and deactivating a cation.

As a polymer used as the said liquid crystal aligning agent, a polyisocyanurate type polymer, a polyimide type polymer, a polyamide type polymer, a polyester type polymer, a polyether type polymer, a polythioether type polymer, a polyurethane type polymer, poly (Amide-imide) polymer, poly (amide-ester) polymer, poly (ether-thioether) polymer, poly (imide-urethane) polymer, poly (amide-urethane) polymer, In addition, acrylic polymers containing polymethyl methacrylate, polyolefin polymers including polyethylene, polypropylene series, polystyrene polymers, polyacetal polymers, phenolic polymers, epoxide polymers and polysiloxane polymers are used alone. Or two or more thereof are preferable.

At this time, for the optical orientation as described below, the polymer is a cinnamate of the following [structure 1], a chalcone of the following [structure 2], an azo compound of the following [structure 3], an imide of the following [structure 4], The photoactive unit of any one of cinnamildene malonate of [structure 5] and styryl acrylate of [structure 6] below is included in the main chain or side chain as a photosensitive functional group.

[Structure 1]

Structure 2

Structure 3

[Structure 4]

[Structure 5]

[Structure 6]

It is preferable that the diameters of the silica mixed with the said liquid crystal aligning agent are 500 nm or less, and the mixing ratio with respect to a liquid crystal aligning agent composition is 0.001-5 wt%.

When the diameter of the silica exceeds 500 nm, it may act as a foreign material to the optical system of the liquid crystal.

Moreover, when the mixing ratio with respect to a liquid crystal aligning agent composition becomes less than 0.001 wt%, there is no addition effect, and when it exceeds 5 wt%, there exists a possibility that brightness may be reduced by light scattering, reflection, etc.

The liquid crystal aligning film which concerns on this invention is produced using the liquid crystal aligning agent in which silica was mixed as mentioned above.

Hereinafter, the manufacturing method of the liquid crystal aligning film which concerns on this invention is explained in full detail.

First, for example, chlorobenzene, N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N, N-dimethylimidazolidinone (DMI), N, N-dipropylimidazolidinone (DPI), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), cyclopentanone, cyclohexanone, dichloroethane, butylcellulose, gamma butyrolactone and tetrahydrofuran (THF In the organic solvent consisting of any one or at least any two or more mixed solvents selected from the group consisting of), the polymer liquid crystal aligning agent is dissolved so that the concentration of the polymer liquid crystal aligning agent with respect to the organic solvent is 1 to 20wt%, the organic solvent Make the viscosity of the mixed solution of the polymer liquid crystal aligning agent with 1 ~ 100cps (S1).

Next, silica is mixed into the solution at a predetermined concentration (S2).

Next, the mixed solution is applied onto the substrate 2, for example, the ITO glass substrate 2, by a spin coating or printing method to form a alignment layer 10 (S3).

At this time, if necessary to remove the impurity particles not dissolved in the organic solvent between the step S2 and S3, the step of passing the mixed solution through the filtration membrane may be further performed.

In the production of the liquid crystal alignment film according to the present invention, the method of forming the alignment is performed by the optical alignment method, and when the optical alignment method is used, the thickness applied to the substrate is preferably 50 to 500 nm.

In the case of less than 50 nm, the alignment film is difficult to form, and in the case of more than 500 nm, the formation of the photo alignment is not easy.

Next, the liquid crystal aligning agent having the photosensitive functional group is subjected to a step of aligning the liquid crystal by inclining or vertically irradiating ultraviolet rays linearly polarized using a polarizer or non-polarized ultraviolet rays not using a polarizer on a surface of the alignment layer. (S4).

3 is a schematic view showing an irradiation step in the alignment process of the liquid crystal alignment film 10 using the photosensitive polymer liquid crystal aligning agent composition according to the present invention.

As shown in FIG. 3, the surface of the alignment layer 10 is inclined or vertically irradiated with the linearly polarized ultraviolet ray 80 using the polarizer or the unpolarized ultraviolet ray 80 without using the polarizer for 2 seconds to 10 minutes. Irradiation produces a liquid crystal aligning film 10 on the substrate 20.

The irradiation time depends on the power of the lamp. The larger the power, the shorter the irradiation time. The smaller the power, the larger the irradiation time. For lamps of approximately 500W, tilt or level for 2 seconds to 10 minutes.

The manufacturing method of the liquid crystal element by which the orientation is formed by the liquid crystal aligning film 10 using the liquid crystal aligning agent composition containing a silica which concerns on this invention is as follows.

After spraying a spacer having a predetermined size on the two photoreacted substrates having the liquid crystal alignment film 10 prepared according to the above, and then attached by using an adhesive to have a constant thickness between the two substrates, it was 1 hour at 130 ℃ After the curing process, the adhesive is cured so that the two substrates are completely bonded to fabricate the device. Thereafter, the liquid crystal is injected into the device, heat is applied at 100 to 130 ° C. for about 1 hour, and then a heat treatment step of dropping the temperature back to room temperature is performed once.

Unlike the conventional method of incorporating silica into the liquid crystal placed between the alignment films, the present invention mixes the silica in the alignment film manufacturing step, so that the characteristics of the liquid crystal device are not deteriorated, and in particular, the pretilt angle can be adjusted.

The liquid crystal display device according to the present invention may be applied to various modes such as super twisted nematic (STN), twisted nematic (TN), in plane switching (IPS), and vertically alligned twisted nematic (VATN) mode.

In this application to various drive modes, it is possible to adjust the pretilt angle appropriately according to one drive mode without using the replacement method of the alignment agent model according to the drive mode, which is a limitation of the conventional alignment agent, thus providing fixed compatibility. This rises.

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 to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only common to those skilled in the art to complete the present disclosure. It is intended to facilitate the implementation of the invention to those with knowledge.

Example 1

Embodiment 1 relates to a liquid crystal aligning agent composition in which a polyamide photosensitive polymer having a chalcon photosensitive functional group and silica is mixed, a method of manufacturing a liquid crystal aligning film using the same, and a liquid crystal device including the liquid crystal aligning film.

(1) Synthesis of Chalcone Photosensitive Functional Group

10 g of 4-methoxychalcone and 2.05 g of sodium cyanide were dissolved in 100 ml of dimethyl sulfoxide and allowed to react for 24 hours. After completion of the reaction, the reaction solution was mixed with chloroform and stirred with distilled water to extract impurities. After removing the aqueous phase, chloroform was removed under reduced pressure at room temperature. The remaining solid phase was recrystallized in methanol and then dried in vacuo at 40 ° C. to obtain side chain 4-hydroxychalcone for photoreaction.

(2) Introduction of Chalcone Photosensitive Functional Groups into Triazine Rings

23.8 g of the obtained 4-hydroxychalcone was placed in a round bottom flask filled with nitrogen and dissolved in 240 ml of tetrahydrofuran from which moisture was removed. 2.4 g of sodium hydride (NaH) was added thereto and allowed to react at room temperature for 6 hours. 18.4 g of cyanuric chloride was added to a round bottom flask, and the solution was dissolved in 200 ml of tetrahydrofuran from which water was removed. The solution was reacted vigorously with vigorous stirring at −5 ° C. for 24 hours. After completion of the reaction, distillation under reduced pressure was carried out to remove tetrahydrofuran, and the obtained solid was dissolved in chloroform again. The solution was washed three times with distilled water in a separatory funnel to extract impurities, and then water was removed with calcium chloride. The solution was distilled under reduced pressure again to remove chloroform and recrystallized with a mixed solvent of methylene chloride and normal nucleic acid. The obtained material was filtered under reduced pressure and then vacuum dried to obtain triazine having a chalcone photosensitive functional group.

(3) Synthesis of Triazine Monomer Having Two Amine Functions

38.6 g of the triazine having the above-described chalcone photosensitive functional group was dissolved in 300 ml of distilled water in which 32.8 g of 4-aminophenol and 12 g of sodium hydroxide were dissolved in 3 g of cetyltrimethylammonium bromide, followed by a vigorous reaction 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 chloride. The water-removed solution was distilled under reduced pressure to remove chloroform, which is an organic solvent, and then recrystallized in a mixed solvent of methylene chloride and normal nucleic acid. The precipitated crystals were filtered under reduced pressure and dried in vacuo to obtain a triazine monomer.

(4) Polymerization of a polyamide photosensitive polymer liquid crystal aligning agent having a chalcone photosensitive functional group

53.15 g of the obtained triazine monomer was placed in a round bottom flask filled with nitrogen and dissolved in 400 ml of tetrahydrofuran from which moisture was removed. 20.24 g of triethylamine was added to this solution. After dissolving 20.3 g of terephthaloyl chloride in 100 ml of tetrahydrofuran from which water was removed, the mixture was stirred vigorously while slowly dropping into the solution in which the triazine monomer and triethylamine were dissolved, followed by reaction for 12 hours. After completion of the reaction, the reaction solution was slowly poured into methanol to precipitate and filtered, and the precipitate was dried in vacuo. The obtained precipitate was again dissolved in tetrahydrofuran and then precipitated in methanol twice. After vacuum drying, a polyamide photosensitive polymer liquid crystal aligning agent having a chalcon photosensitive functional group was finally polymerized using a triazine ring.

(5) Preparation of liquid crystal display element

The obtained polyamide photosensitive polymer liquid crystal aligning agent was dissolved in a solvent (1: 1 mixed solvent of NMP and butyl cellussolve) at 8wt% to make a solution. Silica having a diameter of 500 nm or less was mixed with the sample at 0 wt%, 0.5 wt%, and 1 wt%, respectively, 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. The substrate was then heat treated at 180 ° C. for about 1 hour to remove the solvent. The glass substrates were prepared by inducing a complex photoreaction such as photopolymerization of chalcone groups and photolysis of polymer chains through a single irradiation of light for 2 seconds to 10 minutes at an angle of 20 ° to ultraviolet light of a 500W mercury lamp. It was.

Subsequently, a spacer having a size of 4˜5 μm was sprinkled on the photoreacted two glass substrates, and then attached so that the thickness (cell gap) between the two glass substrates was 4˜5 μm using an epoxy adhesive. The cell was subjected to a curing process at 130 ° C. for 1 hour to cure the epoxy adhesive so that the two glass substrates were completely bonded to complete the manufacture of the cell. After injecting the liquid crystal into the finished cell at room temperature, the crystals were treated at a clearing temperature, that is, at 100 to 130 ° C. for 5 minutes, to evenly orient and cool to complete the device.

Example 2

This Example 2 relates to a liquid crystal aligning agent composition in which a polyacrylic polymer having a cinnamate photosensitive functional group and silica is mixed, a method of manufacturing a liquid crystal aligning film using the same, and a liquid crystal device including the liquid crystal aligning film.

(1) Introduction of cinnamate functional group

14.8 g of cinnamic acid was placed in a round bottom flask filled with nitrogen, and 17.8 g of thionyl chloride (SOCl ₂ ) was added thereto, followed by stirring. Then, 0.5 ml of dimethylformamide (DMF) was further added to the flask, followed by reaction at room temperature for 24 hours. After the reaction was completed, distillation under reduced pressure was carried out to obtain 16 g of cinnamoyl chloride.

(2) formation of amide linkages

7 g of aminophenol was placed in a round bottom flask filled with nitrogen, and 16 g of cinnamoyl chloride diluted in 10 ml of methylene chloride (MC) was slowly added dropwise while keeping 50 ml of pyridine at 0 ° C. After stirring for 1 hour, the reaction product formed a precipitate in 3N aqueous hydrochloric acid solution. The precipitate was filtered, the water was completely removed, recrystallized from methanol, and filtered under reduced pressure. The obtained solid substance was decompressed in vacuum to obtain 18 g of 4-hydroxyphenylcinamide.

(3) an acrylic monomer having a cinnamate photosensitive functional group

15 g of the 4-hydroxyphenyl cinnamid obtained was placed in a round bottom flask filled with nitrogen, 80 ml of tetrahydrofuran (THF) and 30 ml of triethylamine (TEA) were added thereto, dissolved at 0 ° C., and 7 g of methacryloyl chloride. Was slowly added dropwise. After the dropping was completed, the reaction was carried out for 1 hour, and the reactant was formed into a precipitate in 3N aqueous hydrochloric acid solution. . The obtained solid substance was decompressed in vacuum to obtain 10 g of an acrylic monomer having a cinnamate photosensitive functional group.

(4) Polymerization of Acrylic Photoalignment Agent

After dissolving 10 g of the obtained acrylic monomer in 100 ml of tetrahydrofuran, the temperature was maintained at 80 ° C., and then 0.1 g of 2,2 ^and -azobisisobutyronitrile as a radical initiator was slowly added dropwise. After reacting for 12 hours, the reactant formed a precipitate in methanol, and the precipitate was filtered under reduced pressure and dried in vacuo. After dissolving the obtained polymer in tetrahydrofuran and precipitating in methanol twice, vacuum drying was performed to obtain an acrylic polymer liquid crystal aligning agent having low polarity and high light efficiency.

(5) Preparation of liquid crystal display element

The obtained acrylic photosensitive polymer liquid crystal aligning agent was dissolved in a solvent (1: 1 mixed solvent of NMP and butyl cellussolve) at 8wt% to make a solution. Silica having a diameter of 500 nm or less was mixed with the sample at 0 wt%, 0.5 wt%, and 1 wt%, 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 to a thickness of 50 to 500 nm to apply a photoalignment agent. The substrate was then heat treated at 180 ° C. for about 1 hour to remove the solvent. The glass substrates were prepared by inducing a complex photoreaction such as photopolymerization of chalcone groups and photolysis of polymer chains through a single irradiation of light for 2 seconds to 10 minutes at an angle of 20 ° to ultraviolet light of a 500W mercury lamp. It was.

Subsequently, a spacer having a size of 4˜5 μm was sprinkled on the photoreacted two glass substrates, and then attached using a epoxy adhesive such that the cell gap between the two glass substrates was 4˜5 μm. The cell was subjected to a curing process at 130 ° C. for 1 hour to cure the epoxy adhesive so that the two glass substrates were completely bonded to complete the manufacture of the cell. After injecting the liquid crystal into the finished cell at room temperature, the crystals were treated at a clearing temperature, that is, at 100 to 130 ° C. for 5 minutes, to evenly orient and cool to complete the device.

Electro-optical characteristics were measured using the devices of Examples 1 and 2.

Pretilt angle was measured using the crystal rotation method. The apparatus used for the measurement was measured by using the TBA 105 model of Autronics, the change of the pretilt angle according to the silica mixing ratio.

Response time was measured by the change in transmittance (TV-curve) according to the applied voltage using the DMS of Autronics, the response time was the time when the transmittance is changed from 10% to 90%.

Table 1 shows the result of measuring the liquid crystal element of Example 1. FIG.

Silica (wt%) 0 0.5 One Pretilt angle 20 ℃ 5 degrees 8 degrees 11 degrees 60 ℃ 4.8 degrees 7.7 degrees 10.6 degrees Response speed 20 ℃ 25 ms 23 ms 19 ms 60 ℃ 21 ms 19 ms 16 ms

Table 2 shows the results of measuring the liquid crystal device of Example 2. FIG.

Silica (wt%) 0 0.5 One Pretilt angle 20 ℃ 4 degree 7 degrees 9 degrees 60 ℃ 3.9 degrees 6.9 degrees 8.8 degrees Response speed 20 ℃ 25 ms 23 ms 19 ms 60 ℃ 21 ms 19 ms 16 ms

As can be seen in Table 1 and Table 2, it can be seen that the pretilt angle can be adjusted according to the control of the silica ratio, it was confirmed that the response speed also changes depending on the addition ratio of silica.

The present invention improves the problem of adjusting the pretilt angle of the existing alignment agent, and can improve the electro-optical characteristics, and in particular, there is no problem of deterioration of the characteristics of the liquid crystal device, and one alignment film can be appropriately adjusted according to the driving mode. As a result, the fixed compatibility is improved.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (12)

Liquid crystal aligning agent composition WHEREIN: The liquid crystal aligning agent composition containing silica characterized by including silica. The method of claim 1, wherein the silica, The diameter is 500 nm or less, and the mixing ratio with respect to a liquid crystal aligning agent composition is 0.001 wt%-5 wt%, The liquid crystal aligning agent composition containing silica characterized by the above-mentioned. The liquid crystal aligning agent composition of claim 2, Polyisocyanurate-based polymers; Polyimide-based polymers; Polyamide-based polymers; Polyester-based polymer; Polyether polymers; Polythioether polymers; Polyurethane-based polymers; Poly (amide-imide) based polymers; Poly (amide-ester) -based polymers; Poly (ether-thioether) -based polymers; Poly (imide-urethane) -based polymers; Poly (amide-urethane) -based polymers; Acrylic polymers including polymethyl methacrylate; Polyolefin-based polymers including polyethylene and polypropylene series; Polystyrene-based polymers; Polyacetal polymers; Phenolic polymers; Epoxide-based polymers; And polysiloxane-based polymer; Liquid crystal aligning agent composition comprising a silica, characterized in that at least one polymer selected from the group consisting of. The method of claim 2, wherein the polymer, Cinnamate of the following [Structure 1]; The chalcone of the following [Structure 2]; Azo compounds of the following [Structure 3]; The imide of the following [Structure 4]; Cinnamylidene malonate of the following [Structure 5]; And any photoactive unit selected from the group consisting of styryl acrylate of the following [Structure 6] in the side chain. [Structure 1]

Structure 2

Structure 3

[Structure 4]

[Structure 5]

[Structure 6]

The liquid crystal aligning film containing the liquid crystal aligning agent composition in any one of Claims 1-4. Dissolving the liquid crystal aligning agent composition in an organic solvent to prepare a mixed solution (S1); Mixing silica in the solution (S2); Applying the solution onto the substrate (2) by spin coating or printing to form an alignment layer (S3); And Orienting the liquid crystal by inclining or vertically irradiating linearly polarized ultraviolet rays 80 or non-polarized ultraviolet rays 80 without using polarizers on the surface of the alignment layer 10 (S4); The manufacturing method of the liquid crystal aligning film characterized by the above-mentioned. The method of claim 6, wherein the step S2, Silica whose diameter is 500 nm or less is used, and the mixing ratio of the silica with respect to a liquid crystal aligning agent composition is set to 0.001 wt%-5 wt%, The manufacturing method of the liquid crystal aligning film characterized by the above-mentioned. The method of claim 7, wherein the step S1, The liquid crystal aligning agent composition is melt | dissolved in the density | concentration of 1-20 wt% with respect to an organic solvent, and the viscosity of the mixed solution which consists of a liquid crystal aligning agent composition and an organic solvent becomes 1-100 cps, The manufacturing method of the liquid crystal aligning film characterized by the above-mentioned. The method of claim 8, wherein the step S1, As the organic solvent, chlorobenzene, N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N, N-dimethylimidazolidinone (DMI), N, N-dipropylimidazolidinone (DPI), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), cyclopentanone, cyclohexanone, dichloroethane, butylcellulose, gamma butyrolactone and tetrahydrofuran (THF Method for producing a liquid crystal aligning film, using any one or at least any two or more mixed solvents selected from the group consisting of The method of claim 8, wherein the step S1, As a liquid crystal aligning agent composition, Polyisocyanurate type polymer; Polyimide-based polymers; Polyamide-based polymers; Polyester-based polymer; Polyether polymers; Polythioether polymers; Polyurethane-based polymers; Poly (amide-imide) based polymers; Poly (amide-ester) -based polymers; Poly (ether-thioether) -based polymers; Poly (imide-urethane) -based polymers; Poly (amide-urethane) -based polymers; Acrylic polymers including polymethyl methacrylate; Polyolefin-based polymers including polyethylene and polypropylene series; Polystyrene-based polymers; Polyacetal polymers; Phenolic polymers; Epoxide-based polymers; And a polysiloxane polymer; and at least one polymer selected from the group consisting of: a method for producing a liquid crystal alignment film. The method of claim 8, wherein the polymer, Cinnamate of the following [Structure 1]; The chalcone of the following [Structure 2]; Azo compounds of the following [Structure 3]; The imide of the following [Structure 4]; Cinnamylidene malonate of the following [Structure 5]; And any photoreactive unit selected from the group consisting of styryl acrylate of the following [Structure 6] in the side chain. [Structure 1]

Structure 2

Structure 3

[Structure 4]

[Structure 5]

[Structure 6]

A liquid crystal element characterized by comprising a liquid crystal alignment film (10) prepared by any one of claims 6 to 11.

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