JP3026880B2 - Rubbing cloth for aligning liquid crystal molecules and method for manufacturing liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubbing cloth for aligning liquid crystal molecules used for manufacturing a liquid crystal alignment film for aligning liquid crystal molecules, and a method for manufacturing a liquid crystal display device manufactured using the rubbing cloth. is there.

[0002]

2. Description of the Related Art In a liquid crystal display device, generally, a transparent electrode layer made of indium tin oxide (hereinafter abbreviated as ITO) is formed on a glass substrate, and a polymer resin such as polyimide is formed on the transparent electrode layer. A liquid crystal alignment film is formed, and then the liquid crystal alignment film is rubbed (rubbed) in a specific direction using a roller around which a rubbing cloth made of organic fibers is wound, and the liquid crystal alignment film is opposed to the liquid crystal. A method of enclosing is used.

[0003]

However, in such a rubbing treatment method, when a polymer resin film is rubbed with a textile fiber,
A considerable amount of heat is locally generated, and the fibers in the friction portion are gradually damaged, causing a change in shape and the like. Eventually, normal rubbing orientation treatment may not be performed. As a result, there has been a problem that rubbing scratches and rubbing streaks are generated and display quality is impaired.

When a rubbing treatment is performed on a polymer resin film which has been heated to a temperature around the glass transition point in advance,
Since the polymer chains are in an unstable state, alignment processing can be performed under weak rubbing conditions. Therefore, the generation of frictional heat is reduced by doing so, however, in this kind of rubbing orientation treatment, not only the polymer resin film but also the rubbing cloth is heated at the same time, so that the same deterioration as described above occurs.

Therefore, it has been difficult to achieve uniform orientation over a long period of time with the conventional rubbing cloth.

An object of the present invention is to provide a rubbing cloth for aligning liquid crystal molecules having excellent heat resistance and a method for manufacturing a liquid crystal display element using the rubbing cloth in consideration of the problems of the conventional rubbing cloth. I do.

[0007]

SUMMARY OF THE INVENTION The present invention provides a rubbing cloth for aligning liquid crystal molecules, in which the surface of a textile fiber is deformed by frictional heat.
It is a rubbing cloth for liquid crystal molecule alignment that has been heat-treated to such an extent that it can be prevented .

Further, in the present invention, the material for heat-treating the textile fiber is a rubbing cloth for liquid crystal molecule alignment, which is a paint containing silicone as a main component.

Further, according to the present invention, when a polymer resin film provided on a liquid crystal support plate having a transparent electrode layer is subjected to a rubbing alignment treatment, the surface of the textile fiber in contact with the polymer resin film contains silicone as a main component. This is a method for manufacturing a liquid crystal display element, in which a rubbing orientation treatment is performed using a rubbing cloth heat-treated with a paint to be manufactured to manufacture a liquid crystal display element.

[0010]

According to the present invention, the heat resistance of the rubbing cloth surface is improved by coating the surface of the textile fibers forming the rubbing cloth with a paint such as a varnish containing silicone as a main component. Therefore, by using a rubbing cloth treated in such a manner, the durability is remarkably improved as compared with a conventional rubbing cloth not treated with heat resistance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rubbing cloth for aligning liquid crystal molecules and a method of manufacturing a liquid crystal display device according to embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing a processing step of a rubbing cloth for liquid crystal molecule alignment of the present invention. As shown in FIG. 1A, a rubbing cloth 11 is mixed with a solvent 13 containing a silicone varnish.
For a certain period of time. After that, as shown in FIG.
Drying is carried out at a constant temperature for a constant time.

The rubbing alignment treatment is carried out by rubbing the surface of the polymer resin liquid crystal alignment film provided on the glass substrate having the ITO electrode layer using the rubbing cloth 11 thus heat-treated.

FIG. 2 is a cross-sectional view showing the structure of a liquid crystal display element manufactured using the alignment film 23 made of a polymer resin film subjected to the alignment treatment as described above. A transparent electrode layer (ITO layer) 22 is formed on a substrate 21 made of glass, plastic, or the like, and a polymer resin film is formed thereon.
Are prepared, a spacer / seal resin 24 is printed on one of the support plates 25, and the two liquid crystal support plates 25 are bonded together so that the alignment films 23 face each other. More nematic liquid crystal was injected. Thereafter, the opening was sealed to produce a liquid crystal display element. Subsequently, the liquid crystal was heated to a temperature at which the liquid crystal exhibited isotropic properties, annealed at that temperature for 1 hour, and then gradually cooled to complete a liquid crystal display device.

Next, this embodiment will be described more specifically.

Example 1 A silicone varnish was diluted with trichloroethane to prepare a treating agent containing 1.5% by weight of a silicone component. A rubbing cloth 11 made of rayon is immersed in the treating agent as shown in FIG. 1A, and then rubbed on a heater plate 15 which has been set at a predetermined temperature as shown in FIG. 1B. 16 were dried.
Drying conditions are 140 ° C. for 2 minutes.

Next, as shown in FIG. 3, a glass substrate 32 on which a pattern of a transparent electrode layer (ITO layer) 33 is formed by using a roller 35 around which a heat-treated rubbing cloth 36 is wound.
The surface of the polyimide-based alignment film 34 provided above was rubbed four times in the same direction, and a rubbing treatment was performed to complete a liquid crystal alignment film. This rubbing treatment step was continuously performed using the same rubbing cloth 36 to obtain 150 alignment films for liquid crystal. Reference numeral 31 denotes a rubbing stage.

A liquid crystal display device was manufactured by the following method by forming a set of two liquid crystal support plates on each of which a liquid crystal alignment film of polyimide was formed by such a treatment. Therefore, the number of completed liquid crystal display elements is 75. FIG. 4 is a view showing the structure of a liquid crystal display element. Glass fibers having a diameter of 6.0 μm are used as spacer / seal resin 45 on the surface of one support plate (for example, lower liquid crystal support plate 42) on which an alignment film is formed. After printing the dispersed acid anhydride-curable epoxy resin on the other side at a width of 0.2 mm, leaving a width of 5 mm at the center of only one side,
The rubbing directions 43 and 44 of the alignment films formed on the upper liquid crystal support plate 41 and the lower liquid crystal support plate 42 were parallel to each other, and the surfaces of the alignment films were opposed to each other. After bonding, a nematic liquid crystal (trade name: ZLI-2293, manufactured by Merck) was injected by vacuum injection, and after the injection, the opening 46 was sealed with a commercially available acid anhydride-curable epoxy resin. After sealing, the liquid crystal was heated to a temperature at which the liquid crystal exhibited isotropic properties, annealed at that temperature for 1 hour, and then gradually cooled to complete a liquid crystal display device.

The liquid crystal display device completed in this way is 75
A uniform display with almost no rubbing scratches or rubbing lines showed the display state.

(Comparative Example 1) As shown in FIG. 5, a transparent electrode layer (ITO layer) 53 was formed by using a roller 55 around which a rubbing cloth 51 made of the same rayon as in Example 1 not subjected to heat resistance treatment was wound. Patterned glass substrate 52
The surface of the polyimide-based alignment film 54 provided above was rubbed four times in the same direction, and a rubbing treatment was performed to complete a liquid crystal alignment film. This rubbing treatment step was continuously performed using the same rubbing cloth 51 to obtain 150 alignment films for liquid crystal.
Hereinafter, in the liquid crystal display devices manufactured by the same operation as in Example 1, 45 out of 75 liquid crystal display devices obtained a uniform display state.

The rubbing cloth for aligning liquid crystal molecules is not limited to rayon shown in the above embodiment, but various textile fibers such as nylon, cellulose and polyester can be used.

The polymer resin film is not limited to the above-mentioned polyimide, but may be used for various synthetic polymer films such as polyamide and polyvinyl alcohol, and also for natural polymer films such as polypeptides and proteins.

The heat-resistant treatment of the rubbing cloth of the present invention is as follows:
The heat treatment is not limited to the above-described treatment with silicone, and may be another heat treatment.

[0024]

As is apparent from the above description,
In the present invention, since the surface of the textile fibers of the rubbing cloth for liquid crystal molecule alignment is heat-treated, when a liquid crystal display element is manufactured using the rubbing cloth, a uniform display state without display defects such as rubbing streaks is exhibited. There is an advantage that a liquid crystal display element can be manufactured for a long time.

[Brief description of the drawings]

FIG. 1 is a view showing a heat treatment step of a rubbing cloth for liquid crystal molecule alignment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a liquid crystal display element manufactured using a polymer resin coating film subjected to a rubbing alignment treatment using the rubbing cloth for liquid crystal molecule alignment of the present invention.

FIG. 3 is a view showing a step of rubbing a polymer resin film using the rubbing cloth for liquid crystal molecule alignment of the present invention.

FIG. 4 is a diagram showing a configuration of a liquid crystal display element manufactured using a polymer resin coating film subjected to a rubbing alignment treatment using the rubbing cloth for liquid crystal molecule alignment of the present invention.

FIG. 5 is a diagram illustrating a process of rubbing a polymer resin film using a rubbing cloth for liquid crystal molecule alignment, for explaining a comparative example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 rubbing cloth 12 rubbing cloth support rod 13 heat-resistant treatment agent 14 rubbing cloth treatment tank 15 heater plate 16 heat-treated rubbing cloth 21 substrate 22 transparent electrode layer 23 alignment film 24 spacer / seal resin 25 liquid crystal support plate 31 rubbing stage 32 glass Substrate 33 Transparent electrode layer 34 Alignment film 35 Rubbing roller 36 Heat-treated rubbing cloth 41 Upper liquid crystal support plate 42 Lower liquid crystal support plate 43 Rubbing direction of upper liquid crystal support plate 44 Rubbing direction of lower liquid crystal support plate 45 Spacer Sealing resin 46 Opening 51 Rubbing stage 52 Glass substrate 53 Transparent electrode layer 54 Alignment film 55 Rubbing roller 56 Rubbing cloth

Claims (3)

(57) [Claims] 1. A rubbing cloth for aligning liquid crystal molecules, characterized in that the surface of the textile fibers of the rubbing cloth for aligning liquid crystal molecules is heat-treated to such an extent that deformation by frictional heat can be prevented . 2. The rubbing cloth for aligning liquid crystal molecules according to claim 1, wherein a material for performing the heat treatment of the textile fiber is a paint containing silicone as a main component. 3. A rubbing alignment treatment for a polymer resin film provided on a liquid crystal support plate having a transparent electrode layer, wherein the surface of the textile fibers in contact with the polymer resin film is coated with a paint containing silicone as a main component. A method for manufacturing a liquid crystal display element, comprising: performing a rubbing alignment treatment using a rubbing cloth subjected to heat treatment to manufacture a liquid crystal display element.