JP2007232938A - Rubbing cloth - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of static electricity by making a conductive material constitute a rubbing cloth, and at the same time to additionally prevent the occurrence of fine dust/foreign matters caused by chafing and shaving of the conductive material constituting the rubbing cloth. <P>SOLUTION: The rubbing cloth for manufacturing a liquid crystal display panel is composed of woven fabric, and is characterized by containing composite fiber of a sheath/core structure composed of a core comprising the conductive material and a non-conductive material to coat the core, wherein the conductive material is substantially not exposed on the rubbing surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rubbing cloth made of a woven cloth used in a rubbing process when aligning the surface of an alignment film when manufacturing a liquid crystal display panel.

  The alignment process of the liquid crystal display panel is performed by winding a rubbing cloth dried on an insulating resin thin film made of polyimide resin, for example, an alignment film applied on an insulating substrate, around a rotating drum via a double-sided adhesive. Rub the alignment film while Thereby, micro grooves aligned in one direction are formed on the surface of the alignment film, and liquid crystal molecules in contact with the aligned micro grooves are arranged.

The fibers of the rubbing cloth are synthetic fibers such as polyester, polyamide, acrylic, and polypropylene, recycled fibers such as rayon, and natural fibers such as cotton.
The rubbing cloth is used after being dried, and a large amount of static electricity is generated due to friction and peeling electrification to rub the dry cloth. The amount generated varies depending on alignment film characteristics, rubbing cloth material, temperature, humidity and other environmental conditions, rubbing time, pressing pressure, and other processing conditions. It is inevitable that the insulating substrate is charged.
The degree of electrostatic charging is a high voltage of about 1 to 20 KV, and since it is a high voltage, it can cause various troubles.

  As the rubbing cloth material, for example, a velvet fabric composed of a ground cloth and a pile woven into the ground cloth in a raised state is used, and the rubbing is performed including the raised portion. Other than velvet woven fabrics are also used, all of which are woven fabrics raised with piles, and piles woven in a raised state on a base fabric are appropriately cut and raised.

Here, in order to reduce the static electricity, it has been proposed to use a conductive material such as a conductive fiber for the rubbing cloth.
For example, Patent Document 1 proposes that yarns made of conductive fibers are woven into a stripe shape or a lattice shape.
Further, Patent Document 2 discloses a rubbing cloth using fibers formed by kneading conductive fibers or antistatic agents in a raised layer.
In addition, not only rubbing cloth, but generally conductive fibers, such as metal fibers, surface metallized fibers, carbon fibers, conductive ceramic fibers, etc. are used as conductive fibers, or carbon powder, metal For example, a conductive powder such as a powder is kneaded into a resin and spun into fibers. The conductive fiber is further used as a blended yarn with cotton yarn or synthetic yarn.
JP-A-7-191321 JP 2005-91899 A

On the other hand, since the rubbing operation is a friction operation as described above, the rubbing portion of the rubbing cloth during the rubbing operation may be scraped and scraped to generate a certain amount of minute dust / foreign matter.
In particular, the conductive material is generally not resistant to stress such as friction, and therefore, if the conductive material is used for the rubbing cloth, the generation of static electricity can be suppressed, but it is caused by abrasion of the conductive material. The generation of minute dust and foreign matter is inevitable.
The fine dust / foreign matter generated in this way floats in the ambient atmosphere after the alignment treatment, and is attracted to and adhered to the alignment film, changing the cell gap as a foreign matter on the alignment film as dot-like white or A display defect occurs as a black spot defect, and when it is severe, the yield of the product is reduced as a defective product.

  In view of this, the present inventors have proposed the use of a composite fiber having a sheath / core structure, the core being made of a conductive material, and the sheath being a sheathing material covering the core as the sheath. Although such a composite fiber is covered with a core conductive material with a sheath, since the core is conductive, it can be expected to have a certain antistatic effect due to corona discharge into the air. Static electricity will not accumulate easily.

Furthermore, in order to be woven with a fiber having the above-described core / sheath structure and to be a rubbing cloth, as described above, as a woven fabric represented by a velvet woven fabric, rubbing is performed using the raised portion. . That is, all are woven fabrics raised by piles, and piles woven in a raised state in the ground fabric are woven fabrics that are appropriately cut and raised.
Therefore, if the sheath / core structure fiber is used, the pile is cut and eventually the conductive material constituting the core is exposed, and the pile portion corresponds to the rubbing portion. May lead to the occurrence of

  Although a rubbing cloth is composed of a conductive material to suppress the generation of static electricity, it is also desired to simultaneously suppress the generation of fine dust and foreign matters due to abrasion and scraping of the conductive material constituting the rubbing cloth.

That is, a first aspect of the present invention is a rubbing cloth for manufacturing a liquid crystal display panel made of a woven cloth, the cloth having a sheath / core structure made of a conductive material and a non-conductive material covering the core. The present invention provides a rubbing cloth for producing a liquid crystal display panel, comprising a composite fiber, wherein the conductive material is not substantially exposed on the rubbing surface.
A second aspect of the present invention has a ground fabric structure composed of warp and weft yarns, and a pile yarn woven into the ground fabric structure. The pile yarn is composed of a conductive material and a non-conductive coating for the core. The present invention provides a rubbing cloth for producing a liquid crystal display panel, characterized in that it comprises a composite fiber made of a functional material, and the pile forms an uncut circular pile.
A third aspect of the present invention relates to a rubbing cloth according to the second aspect of the present invention, wherein the warp and / or the weft of the fabric structure contains a conductive material.
According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the warp and / or the weft of the base fabric structure is composed of a core made of a conductive material and a non-conductive material covering the core. The present invention relates to a rubbing cloth characterized by being.
A fifth aspect of the present invention is the rubbing cloth according to the second or third aspect of the present invention, wherein the warp and / or the weft of the fabric structure is composed of a mixture of a conductive material and a non-conductive material. About.
A sixth aspect of the present invention is characterized in that in the second or third aspect of the present invention, the warp and / or the weft of the ground fabric is a mixture of fibers made of a conductive material and non-conductive fibers. It relates to rubbing cloth.
A seventh aspect of the present invention relates to the rubbing cloth according to any one of the first to sixth aspects of the present invention, wherein the conductive material is a carbon material or a conductive ceramic.
An eighth aspect of the present invention relates to the rubbing cloth according to any one of the first to seventh aspects of the present invention, wherein the nonconductive fiber is a synthetic fiber or a natural fiber.
9th of this invention is related with the rubbing cloth characterized by attaching to a rubbing roller in any one of 1st-7th of this invention with a conductive adhesive.

  By forming a rubbing cloth with a conductive material, it is possible to suppress the generation of static electricity and at the same time suppress the generation of fine dust and foreign matter due to the abrasion and scraping of the conductive material constituting the rubbing cloth.

In the present invention, a woven fabric woven with so-called sheath / core fibers is used as the rubbing fabric. The fiber employs a composite fiber having a sheath-core structure as shown in FIG.
Here, in FIG. 1, 111 indicates the core of the composite fiber and is made of a conductive material. As this conductive material, a metal fiber, a surface metallized fiber, a carbon fiber, a conductive ceramic fiber or the like itself, or a conductive powder such as carbon powder or metal powder is kneaded into a resin and spun. It is formed into a fiber or the like.

The entire outer layer 222 is covered with a covering material made of a resin such as polyester, acrylic, or polyamide. Since the type, thickness, and the like of the covering material are appropriately selected, the composite fiber shown in FIG. 1 has an effect of reducing the generation of static electricity due to the central conductive material.
Each of the middle core and the outer layer can be appropriately formed into a plurality of layers.

1 can be manufactured by extruding and spinning a covering material with a concentric die centering on the core of 111, for example.
The rabin cloth is formed by weaving at least a part of the above-mentioned composite fiber, and a cloth simply formed by weaving the above-mentioned composite fiber at at least a part of the weft can also be used. It is preferable to provide unevenness such as bumps, and more preferable is a cloth raised by so-called fluffing treatment, and the raised portion is rubbed.

  Explaining the above-mentioned raising treatment, as shown in FIG. 2 (a), fibers A and B are warp yarns of the fabric, and 1, 2, 4, 5, 7, 10, 11, 13, and 14 are fabrics of fabric. The pile 15 is formed by weaving the pile fibers C through the wires 3, 6, 9, 12 and the like. Next, when the wires 3, 6, 9, 12 are pulled out and the pile yarn 15 is cut with the blade 16 as shown in FIG. 2B, the fabric 17 shown in FIG. A fabric in which the piles 18 are raised is obtained.

  The conventional rabin cloth is a woven cloth that is raised by cutting a pile as described above, including a cloth made of conductive fibers proposed in the above-mentioned patent document.

However, when the fibers are cut, the conductive fibers shown as the core in the cross section are exposed to the outside, and there is a possibility that the exposed conductive material is contaminated.
Therefore, in the present invention, the raised portion is simply constituted by a ring pile that is a semicircular pile. This is preferable because exposure of the conductive fibers can be avoided and the rubbing effect can be further improved at the ring pile portion. Such a rubbing cloth is, for example, a rubbing cloth as shown in FIG. 3, and in the figure, the base cloth includes fibers A and B as warp yarns 19, 1, 2, 4, 5, 7, 10, 11, 13. , 14 are woven with wefts 20, and the pile yarn C woven in a warp shape remains as a ring pile 21 in a semicircular shape without being cut.

An appropriate manufacturing method is adopted for manufacturing a rubbing cloth in which the raised portions are formed of ring piles. For example, in FIG. 2A, the wires 3, 6, 9, and 12 are simply removed. Even if it manufactures by omitting the cutting process by the blade 16 shown in FIG. 2C, it can be easily obtained.
Here, in FIG. 3, only the circular pile yarn 21 is used as the composite fiber of the present invention having a sheath-core structure, and the other warp and weft yarns 18 and 19 are not composited (not having a sheath-core structure). It can also be conductive fibers or simply normal non-conductive fibers. Further, both the ring pile yarn 20 and the warp and weft yarns 18 and 19 can be the composite fiber of the present application. Preferably, the ring pile yarn is the composite fiber of the present application, and the other warp yarns are both conductive as the composite fiber of the present application or the conventional conductive fiber. Here, the conventional conductive fiber includes, for example, a fiber obtained by kneading a conductive powder such as a metal fiber itself, carbon powder, or metal powder into a resin and spinning it. This conductive fiber is also used as a blended yarn with cotton yarn or synthetic yarn.

For rubbing with the above-mentioned rubbing cloth, for example, as shown in FIG. 4, the conductive rubbing cloth 22 of the present application is wound around a rubbing roller 23 via an adhesive material 24 such as a double-sided adhesive material, and this is rotated. The alignment film 26 on the glass substrate 25 is rubbed while being rubbed. Corona discharge 28 is generated in the air from the surface of the conductive rubbing cloth 24. As a result, the rubbing cloth is less likely to accumulate static electricity, and the potential of the alignment film is hardly increased.
Here, if the adhesive material 24 is a conductive adhesive material, the rubbing roller 22 is made of metal such as stainless steel or aluminum, so that it is electrically connected. Then, ground discharge is performed from the ground 27. As a result, the rubbing cloth is less likely to accumulate static electricity.

A composite fiber having a sheath-core structure as shown in FIG. 1 having carbon as a core and an outer layer coated with a polyester clothing material was used.
A ground fabric was woven using the above-mentioned composite fiber as a warp and weft. At this time, pile yarns made of the same composite fiber were woven through a wire as shown in FIG.
Next, the pile yarn formed in a ring shape was left as it was, and the wire was pulled out to form a ring pile. Thus, a rubbing cloth in which a ring pile of the same composite fibers was formed on the base cloth woven with the composite fibers as shown in FIG. 3 was obtained.

As shown in FIG. 4, when obtained, the buffing cloth was adhered to a stainless rubbing roll 23 with a double-sided adhesive tape (commercially available) made of a conductive adhesive material containing conductive metal powder.
The rubbing cloth was attached as described above, this was rotated in the direction of the arrow in the figure, and the alignment film (film thickness 0.2 μm) made of polyimide on the glass substrate was rubbed in the direction of the arrow in the figure. At this time, the rubbing roll was grounded and grounded.
As a result, during the rubbing treatment, the electrostatic charge state was improved as compared with the case where a conventional rubbing cloth made of a synthetic fiber was used by corona discharge. The charged state was further improved by earth discharge.
In addition, minute dust and foreign matter due to the conductive material were hardly detected, and the product yield was not reduced.

The figure which shows the composite fiber of the sheath-core structure which uses the center core used for this invention as an electroconductive material, and coat | covers it with a coating | covering material. The figure which shows the process (c) which weaves a pile thread | yarn through the wire (a), cut | disconnects this pile thread | yarn (b), and raises the ground fabric woven with the warp and weft. The figure which shows the rubbing cloth by which the ring pile was woven in the ground fabric woven with the warp and weft which concerns on this invention. The figure which shows the state which winds a rubbing cloth around a rubbing roller and rubs an alignment film.

Explanation of symbols

111 Middle core 222 Covering material A, B Warp of fabric 1, 2, 4, 5, 7, 8, 10, 11, 13, 14 Weft of fabric 3, 6, 9, 12 Wire C Pile yarn 15 Pile 16 Cutting blade 17 Base cloth 18 Fluff 19 Base cloth warp 20 Base cloth weft 21 Ring pile warp 22 Conductive rubbing cloth 23 Rubbing roller 24 Adhesive material 25 Glass substrate 26 Orientation film 27 Earth 28 Corona discharge

Claims (9)

  A rubbing cloth for manufacturing a liquid crystal display panel comprising a woven cloth, the cloth comprising a core made of a conductive material and a composite fiber of a sheath / core structure made of a non-conductive material covering the core, and on the rubbing surface The rubbing cloth for manufacturing a liquid crystal display panel, wherein the conductive material is not substantially exposed.   A composite having a fabric structure composed of warps and wefts and a pile yarn woven into the fabric structure, the pile yarn comprising a core made of a conductive material and a non-conductive material covering the core A rubbing cloth for manufacturing a liquid crystal display panel, comprising a fiber, wherein the pile forms an uncut circular pile.   The rubbing cloth according to claim 2, wherein the warp and / or the weft of the fabric structure contains a conductive material.   The rubbing cloth according to claim 2 or 3, wherein the warp and / or the weft of the ground fabric structure is composed of a composite fiber composed of a core made of a conductive material and a non-conductive material covering the core.   The rubbing cloth according to claim 2 or 3, wherein the warp and / or the weft of the fabric structure is composed of a mixture of a conductive material and a non-conductive material.   The rubbing cloth according to claim 2 or 3, wherein the warp and / or the weft of the fabric structure are a mixture of fibers made of a conductive material and non-conductive fibers. The rubbing cloth according to claim 1, wherein the conductive material is a carbon material or a conductive ceramic.   The rubbing cloth according to any one of claims 1 to 7, wherein the nonconductive fibers are synthetic fibers or natural fibers.   The rubbing cloth according to any one of claims 1 to 8, wherein the rubbing cloth is attached to a rubbing roller via a conductive adhesive and subjected to a rubbing treatment.

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