JP2507747B2 - Liquid crystal rubbing material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystal rubbing material. More specifically, it relates to a liquid crystal rubbing material having an effect of removing static electricity.

(Prior art) In recent years, due to the rapid progress of the electronics industry, the display device market centering on display devices in the computer peripheral terminal device market has entered a period of full-scale diffusion such as office automation and factor automation It continues to grow.

Liquid crystal display devices are used as display devices for game computers, liquid crystal televisions, facsimiles, telephones, watches, cameras and the like. In manufacturing a liquid crystal display device, it is most important to make the liquid crystal alignment uniform. The most typical liquid crystal alignments are horizontal alignment and vertical alignment of N liquid crystal, and as a method for obtaining horizontal alignment, there are a rubbing method and an oblique vapor deposition method.

The rubbing method uses a polymer film such as SiO ₂ , polyimide, or PVA on a glass plate that is a liquid crystal cell and its substrate.
In addition, for the surface of polymer film, for example, for polyester etc., modified PVA, nylon-epoxy-organotitanium-based film, etc. is used as the alignment film, and the surface of the glass plate or each alignment film is unidirectionally rubbed with cloth etc. This is a method of obtaining orientation by doing (called rubbing).

Conventionally, synthetic cloth such as cotton cloth, absorbent cotton, polyester, nylon, etc. has been used as a liquid crystal rubbing material. In the case of cotton thread or absorbent cotton, however, the cotton thread adheres to the substrate of the liquid crystal cell during rubbing. In the case of synthetic fiber cloth such as polyester and nylon, static electricity is generated during rubbing, and dust, lint, and the like are attached to the substrate due to static electricity. As a result, disconnection or short circuit of the electrodes is induced, which causes factors such as uneven alignment of liquid crystal molecules, poor sealing, short circuit between the segment electrode and the common electrode, and causes abnormality of the liquid crystal display device. Furthermore, conventionally, the form of the cloth used for rubbing is a plain woven fabric, a twill woven fabric, and a satin woven fabric, which are not sufficient for uniform alignment of liquid crystals, and due to these defects, an abnormality of the liquid crystal display device is caused, As a result, the yield of the liquid crystal display device is very poor.

(Problems to be Solved by the Invention) In view of the drawbacks of the rubbing material, the present inventors have completed the present invention as a result of earnest research on the form of the liquid crystal rubbing material and the orientation of the liquid crystal.

An object of the present invention is to provide a liquid crystal rubbing material which can obtain uniform alignment of liquid crystals in liquid crystal rubbing, thereby eliminating defective products in liquid crystal display devices and the like.

(Means for Solving Problems) That is, the present invention is a pile fabric, wherein the pile is made of regenerated cellulose filament yarn, the warp of the fabric is made of twisted filament yarn, and the weft of the fabric is made of A liquid crystal rubbing material, which is a pile structure made of twisted filament yarn or spun yarn mixed with antistatic fibers or conductive fibers.

The pile structure referred to in the present invention is a structure having pile yarns and is, for example, a pile cloth such as velvet, velveteen, cordeloy and the like.

In the pile structure, the material of the pile yarn is a regenerated cellulose yarn fiber, and a viscose rayon fiber is particularly preferable.

In addition, the pile length (the length from the base cloth to the pile thread tip) is
It is preferably 0.5 to 30 mm. If it is less than 0.5 mm, the base cloth contacts the substrate during rubbing, which is not preferable. Also, 30 mm
If it exceeds the range, the static elimination performance is deteriorated, which is not preferable. The state of the pile thread is not uniform due to the type and orientation of the liquid crystal,
It may be in a napped state or in a bristled state since it is laid down in one direction.

The warp that constitutes the base fabric of the pile structure is a twisted cellulose-based filament yarn. In rubbing the substrate,
If the pile thread comes out of the rubbing material and adheres to the substrate,
Since the liquid crystal has uneven alignment, the warp yarns and the weft yarns of the base yarn constituting the base fabric are twisted to make it difficult for the pile yarn to come off. The twist number is preferably 100 to 1500 T / M. In order to prevent the pile yarn from coming off, use a thermoplastic resin or thermosetting resin.
Back coating.

In rubbing the substrate, in order to prevent static electricity generation, remove static electricity, and eliminate lint and dust adhering to the substrate due to static electricity, the weft yarns that constitute the base fabric of the pile structure are antistatic fibers or conductive fibers. It is a twisted filament yarn or spun yarn mixed.

The antistatic or conductive fiber may be any fiber having a specific resistance of 10 ⁹ ohm · cm or less, and examples thereof include metal fiber, carbon fiber, copper sulfide acrylic fiber, copper sulfide polyamide fiber, copper sulfide cellulose fiber and Metal-plated fibers and the like, but not limited to these. Particularly, an organic fiber containing copper sulfide is preferable in order to enhance the charge removal property. In addition, blending antistatic or conductive fibers with other fibers,
Mixed fibers and mixed twists may be used.

The fibers are used on the entire surface of the weft yarn of the base fabric or with a pitch. When using a pitch, the distance is preferably 20 mm or less.

The rubbing material of the present invention is a pile structure, and by rubbing the liquid crystal cell and its substrate on the side surface of the pile yarn, the orientation of the liquid crystal is made uniform, and the pile yarn uses filament yarn. As a result, the fibers of the liquid crystal cell and its substrate are prevented from adhering during rubbing. or,
If the pile length is 0.5 to 30 mm, rubbing can be performed by the side surface of the pile yarn, and uniform alignment of liquid crystal can be obtained.

Further, in the rubbing material of the present invention, in order to make the liquid crystal alignment more uniform, antistatic or conductive fibers are mixed into the base fabric of the pile structure.

(Example) Hereinafter, the present invention will be described with reference to an example.

The electrical characteristics of the examples are measured under the following conditions.

Measurement conditions: 20 ℃ × 20% RH Friction electrification: JIS-L-1094 B method (rubbing cloth, cotton cloth) The friction electrification voltage when rubbing the liquid crystal substrate is JIS- The frictional electrification voltage when rubbing according to the L-1094 B method is shown.

Half-life: JIS-L-1094 A method Example 1 As a pile structure shown in FIG. 1, viscose rayon yarn 120d / 40f is used for the pile yarn, and copper ammonia method is used for the warp of the ground yarn constituting the base fabric. Rayon yarn 100d / 60f, 300T / M was used, and the weft yarn was a velvet using various yarns shown in Table 1, and the pile length was 2.0 mm.

The electrical characteristics of the pile structure are shown in Table 1.

The weft metal fiber intertwisted yarn shown in No. 1 of Table 1 is made of copper-ammonia rayon yarn 100d / 60f and stainless fiber 8 μm.
It was used by twisting at 300 T / M. [Specific resistance: 10 ^-2 ohm-centimeter].

Copper sulfide cellulose fibers [Resistivity: 10 ⁰ ohm-cm] of the weft shown in No.2 of Table 1, the cellulose concentration of 10% by weight adjusted by a known method, Anmoa concentration of 7 wt%, copper concentration 3.6 wt % Of copper ammonium cellulose solution having a composition of 60% through a spinneret having 60 holes with a diameter of 0.5 mm into a spinning funnel filled with spinning water at a discharge rate of 5.8 m / min and flowing down in the spinning funnel. Coagulation was performed sufficiently while tensioning, and spinning was performed to obtain a yarn containing a coordination compound of copper and cellulose (hereinafter referred to as blue yarn). Spin water temperature at 37 ℃
And flow rate of 300 ml / min, 1.4% by weight of solidified blue thread
Was passed through the sulfuric acid aqueous solution for 0.1 seconds and then through water, and was wound in a ridge-like shape at a speed of 50 m / min. Then, after thoroughly washing with water, it was immersed in an aqueous solution having a sodium sulfide concentration of 5% by weight and a temperature of 80 ° C. for 20 minutes. Then, it was washed with water and dried to obtain copper sulfide cellulose fiber 100d / 60f.

The weft copper sulfide cellulose blended fiber [specific resistance: 10 ⁵ ohm cm] shown in No. 3 of Table 1 has a cellulose concentration of 10 wt% and an ammonia concentration of 7 prepared by a known method.
A copper ammonia cellulose solution having a composition of wt% and copper concentration of 3.6 wt% was spun through a spinneret having 2200 holes having a diameter of 0.6 mm, and coagulated sufficiently in a spinning funnel filled with spinning water. It was The temperature and flow rate of the spinning water used was 30 ° C, 15 l /
Minutes. Subsequently, the fiber surface was regenerated by passing it through a 1.4 wt% sulfuric acid aqueous solution for 0.3 seconds, then cut into a length of 51 mm with a cutter, thoroughly washed with water, and cotton containing a coordination compound of copper cellulose (hereinafter, I call it blue cotton). Next, it is immersed in an aqueous solution having a potassium sulfide concentration of 5% by weight and a temperature of 50 ° C. for 20 minutes, then washed with water and dried to obtain copper sulfide copper short fibers 2
A denier fiber length of 51 mm was obtained. 30% by weight of the fiber, 2 denier of viscose rayon fiber, 70% by weight of 51 mm fiber length
Was mixed at a ratio of 60 to obtain a copper sulfide-copper cellulose mixed-spun fiber having a cotton count of 60.

The copper sulfide polyamide fiber of the weft yarn shown in No. 4 of Table 1 [specific resistance: 10 ² ohm centimeter] is a polyamide-based synthetic fiber 70d / 24f in a 5% by weight aqueous solution of γ-mercaptopropyltrimethylmethoxysilane and tartaric acid 0.5. The mixture was added with wt% and treated at 60 ° C. for 30 minutes, dehydrated and dried, and then heat-treated at 160 ° C. for 3 minutes to carry out a demethanol reaction to introduce a mercapto group into the polyamide synthetic fiber. The fibers were mixed with copper sulfate (0.
(05 mol / l) and sodium thiosulfate (0.45 mol / l) were immersed in the solution, treated at 85 ° C for 30 minutes, washed with water and dried to obtain copper sulfide polyamide fibers 70d / 24f.

As is clear from Table 1, each pile structure exhibited excellent antistatic property, the alignment of the liquid crystal by rubbing was extremely uniform, and no adhesion of fibers to the liquid crystal and the substrate was observed.

Comparative Example Cotton broad and polyester satin fabrics were used as rubbing materials.

When rubbed broadly, cotton threads are remarkably attached to the liquid crystal substrate, the liquid crystal orientation is not uniform, and when rubbed with polyester satin fabric, static electricity (4000 V in friction electrification voltage) is generated, and the liquid crystal orientation is not uniform. An error occurred in the liquid crystal display device.

Example 2 As the pile structure shown in FIG. 1, viscose rayon yarn 120d / 40f was used for the pile yarn, and copper ammonia method rayon yarn 100d / 60f, 300T / M was used for the warp of the base yarn constituting the base fabric. Copper sulfate cellulose fiber used in Example 1 for the weft
A velvet made of 100d / 60F 300T / M and having each pile length shown in Table 2 was experimentally manufactured.

The electrical characteristics of the pile structure are shown in Table 2.

From Table 2, when the pile length is 0.2 mm, the liquid crystal has uneven alignment although the antistatic property is excellent. When the pile length was 50 mm, static electricity was generated, dust was attached to the liquid crystal substrate, and uneven alignment of the liquid crystal occurred. On the other hand, pile length 0.5 to 30 mm
In Example 1, the orientation of the liquid crystal by rubbing was extremely uniform, and no fiber was attached to the liquid crystal or the substrate.

(Effects of the Invention) According to the liquid crystal rubbing material of the present invention, it is possible to obtain uniform alignment of liquid crystal in rubbing of a liquid crystal cell and its substrate, and therefore, to the liquid crystal cell and its substrate that are generated during rubbing. It is possible to obtain stable liquid crystal alignment without the adhesion of fibers and with very little generation of static electricity.

[Brief description of drawings]

 FIG. 1 is a schematic view of the liquid crystal rubbing material of the present invention. 1 ... pile yarn 2 ... base fabric

Claims (2)

(57) [Claims] 1. A pile fabric, wherein the pile is made of regenerated cellulose filament yarn, the warp of the fabric is made of twisted filament yarn, and the weft of the fabric is mixed with antistatic fiber or conductive fiber. A liquid crystal rubbing material, which is a pile structure made of twisted filament yarn or spun yarn. 2. The liquid crystal rubbing material according to claim 1, wherein the pile length of the pile structure is 0.5 to 30 mm.