KR20090079210A - Rubbing cloth - Google Patents

Abstract

A rubbing cloth for use in alignment treatment of an alignment film of liquid crystal display apparatus, characterized in that the rubbing cloth consists of a ground fabric and pile yarns, and that a heat-fusible composite fiber is used in at least some of warp and weft yarns of the ground fabric, and that the pile yarns consist of flat ultrafine fibers of 1.1 dtex or less obtained by splitting of a multilayer laminated conjugate fiber wherein the flatness (ratio of major axis/minor axis) is 4 or higher. Accordingly, there is provided a rubbing cloth that can form uniform fine channels on the alignment film for liquid crystal display apparatus, being easy in handling thereof.

Description

Loving cloth {RUBBING CLOTH}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubbing cloth used for a rubbing process for controlling the orientation of liquid crystal molecules in a manufacturing process of a liquid crystal display device.

In a liquid crystal display device, fine grooves are formed in the alignment film, and the alignment of the liquid crystal molecules is regulated by aligning the liquid crystal molecules along the fine grooves. The step of forming a fine groove in the alignment film is called a rubbing treatment step because of rubbing the alignment film with a pile cloth attached to a rotating roll. The pile cloth used here is called a rubbing cloth, and materials such as rayon and cotton are currently used.

A rayon rubbing cloth is a velvet fabric using cupra rayon for ground yarns and rayon usually for pile yarns. After weaving, shirring, firing and refining, resin processing is performed using fibrin-reactive resin to ensure the stability of the pile, and also vinyl acetate resin or acrylic resin to prevent the pile from falling out. Coating process is given to the back surface with resin.

On the other hand, in the case of the cotton cloth, after weaving, refining and bleaching are performed to remove the wax component and the impurities contained in the cotton itself, and hair shearing is performed. In the case of cotton, since the short fiber has a twist called convolution and is not a straight hair, resin processing by a fibrin reactive resin for stabilizing the pile is not performed. In general, the rayon agent is called a W file, and while it is pressed to sandwich the file between three weft yarns, it is called a V file in cotton. Sufficient back coating is needed.

In general, in a rubbing process using a conventional rayon or cotton rubbing cloth, if the length, inclination angle and density of the pile of the rubbing cloth are not uniform, frictional force on the alignment film becomes uneven, which causes variation in the alignment force of the alignment film. It becomes the cause of reducing the display quality of a liquid crystal panel. In the case of piles formed of general ultrafine fibers, the resilient elastic force is lowered, and the friction force is insufficient, making it difficult to be oriented.

In addition, since the rubbing treatment rubs the alignment film with a rubbing roller which rotates at a high speed, friction, contact, and peeling are repeated to generate static electricity.

This static electricity damages the circuit on the glass substrate, leading to the generation of defective liquid crystal displays. In addition, the rubbing cloth is attached to the metallic roll through the double-sided tape, when the ground of the pile fabric is a cellulosic fiber, it is stretched according to the humidity. That is, it expands at high humidity and contracts at low humidity. For this reason, there exists a problem that rigid humidity control should be performed when affixing a rubbing cloth to the precision cutting, storage, and a rubbing roll.

On the other hand, it is proposed to use the rubbing cross which has the raising part which consists of ultrafine fibers of 1.1 dtex or less for the purpose of improving the liquid crystal display precision (refer patent document 1). However, the microfine fibers specifically described in Patent Document 1 are microfibers having a linear cross section by dividing a composite spun fiber having a hollow radial cross section, and the present inventors rubbed using the same ultrafine fiber. As a result, it turned out that many orientation defects generate | occur | produce. As a reason, in the ultrafine fibers described in Patent Literature 1, the elasticity of the ultrafine fibers constituting the pile is easily lost, and as a result, the superiority of using the ultrafine fibers has not been sufficiently exerted, despite being the ultrafine fibers. I can think of it.

In the rubbing process, since friction, contact, and peeling are repeated between the rubbing cloth and the alignment film rotating at high speed, static electricity is generated, which damages the circuit on the glass substrate, leading to the generation of defective products of the liquid crystal display. In order to prevent this, Patent Document 1 discloses providing conductivity to at least the brushed layer of the brushed fabric in order to prevent charging at the time of rubbing treatment. And as a specific method of imparting antistatic property, the method of kneading antistatic agents, such as carbon black and the fine powder of metal, when spinning an ultrafine fiber is proposed. However, in the case of using the conductive fibers kneaded with the antistatic agent in the pile as described above, in the velvet fabric or the moquette fabric, the antistatic agent such as carbon black or metal powder is exposed on the surface or end surface of the pile yarn. Rubbing the alignment layer with the pile yarn exposed to the antistatic agent causes contamination, and leads to defects in the liquid crystal display device.

On the other hand, in order to avoid the generation of fine dust and foreign substances caused by abrasion and the like of the conductive material described above, the center is made of a conductive material and a super-sheath made of a non-conductive material covering the center. The rubbing cloth which contains the composite fiber of the core) structure, and is not exposed on the rubbing surface substantially the conductive material is proposed (refer patent document 2).

And as a specific aspect, the rubbing cloth which consists of the composite fiber of the said super-core structure mentioned above and which the pile is not cut | disconnected is proposed.

However, in the rubbing cloth described in Patent Document 2, since the conductive composite fiber having a super-core structure is used for the pile yarn, the pile yarn can not be miniaturized and it is difficult to give fine alignment to the alignment film. In other words, the conductive composite fiber having a super-core structure is formed of a conductive material such as metal fiber, surface metallized fiber, carbon fiber, conductive ceramic fiber, or conductive powder such as carbon powder or metal powder. In the form of a kneaded, spun fiber, or the like, and coated with a coating material made of a resin such as polyester, acrylic, polyamide, etc. as an outer layer, and the short fiber fineness of the conductive composite fiber obtained is 5 to 20 dtex. It is hard to obtain a fineness to an extent, and it becomes a remarkably thick pile compared with the pile fineness (1.1-3.3dtex) of a normal rubbing cloth, and it leads to rubbing stains and stripes in partial use, and an inequality electric field is not formed in full use, and it is corona discharge This is not obtained.

Moreover, since the tip of the pile yarn is not an acute angle but a ring pile, the rubbing effect is also attenuated. In addition, when the conductive material is black, no proposal has been made for concealing black to form a concealed layer of white to grayish white.

In addition, in Patent Document 1, in order to prevent the pile portion of the rubbing cloth from falling off, it is described that the vinyl acetate-based or acrylic acid-based resin is coated on the back side, and when a new process called coating is added, the entire rubbing cloth is manufactured. The process lengthens and the cost increases, and processing defects such as contamination in the process also increase.

As described above, a rubbing cloth that can solve problems such as the configuration of an ultrafine fine pile having a high rubbing effect that can improve the liquid crystal display accuracy, contamination by a conductive agent, an increase in cost, and the like has not been proposed.

[Patent Document 1]: Japanese Unexamined Patent Publication No. 2005-91899

[Patent Document 2] Japanese Unexamined Patent Publication No. 2007-232938

Disclosure of Invention

The present invention has been made in view of the above circumstances, and the uniformity of the length, the inclination angle and the density of the pile yarn is not a problem, and the fine and uniform orientation can be achieved by the pile yarn composed of ultrafine fibers having a special cross section. It is an object of the present invention to provide an excellent rubbing cloth which is less contaminated and can omit a coating process even though the antistatic measures are made by conductive fibers.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, as a result of using the microfiber of a special cross section for the pile of a rubbing cloth, the display element with very few orientation defects can be obtained, and also, by using a heat-sealing composite fiber, It was possible to omit the backing step of, and it was found that a rubbing cloth having an improved yield was obtained by using the conductive composite fiber not having the conductive layer exposed, thereby completing the present invention.

That is, this invention is (1) the rubbing cloth used for orientation-processing the alignment film of a liquid crystal display device, Comprising: The rubbing cloth consists of a ground paper and a pile yarn, and is heat-sealable composite to at least one part of the inclination and weft of the ground paper. A rubbing cloth, wherein fibers are used, and the pile yarn is a flat ultrafine fiber of 1.1 dtex or less obtained by dividing a multilayer laminated composite fiber, and is composed of ultrafine fibers having a flatness ratio (ratio of major diameters / short diameters) of 4 or more. , (2) The ground paper contains conductive composite fibers, wherein the conductive composite fibers do not expose the conductive layer on the fiber surface, and the conductive performance is 10 ⁵ to 10 ⁹ Ω / cm per filament described in 1 above. The conductive composite fiber formed by giving a concealed polymer layer to the outer periphery of the rubbing cloth and the conductive layer of (3) conductive composite fibers is used, as described in said (2). To provide ice cloth.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional view of an example of the multilayer laminated composite fiber used as the flat microfiber forming component of the pile yarn of the rubbing cloth of this invention.

It is a schematic cross section which shows an example of the rubbing cloth structure of this invention.

It is a schematic cross section which shows an example of the conductive composite fiber used for this invention.

It is a schematic cross section which shows the conductive composite fiber used for the comparative example of this invention.

<Explanation of symbols for main parts of drawing>

A: Fiber Formable Polymer A

B: Fiber-forming polymer B incompatible with polymer A

1: Multi-layer laminated composite fiber 10: Rubbing cloth

21: file layer 22: ground

23: conductive composite fiber 30, 40: conductive composite fiber

31 conductive layer 32 concealed polymer layer

33: protective polymer layer 41: protective polymer layer

Best Mode for Carrying Out the Invention

As for the rubbing cloth of this invention, the ultrafine fiber used for the pile of a rubbing cloth is a fiber forming polymer as shown in FIG. 1 (in this invention, "polymer" is synonymous with "polymer") A, A flat microfine fiber obtained by dividing a split composite fiber having a special cross-sectional shape of a multi-layer stacked type, which is a collection of flat ultrafine fiber forming components consisting of a fiber-forming polymer B which is incompatible with a polymer A. It becomes a flat ultrafine fiber. The short fiber fineness of the flat ultrafine fibers is preferably 1.1 dtex or less in terms of obtaining a uniform display element without streaks, preferably 0.1 to 1.1 dtex, and more preferably in the range of 0.2 to 0.5 dtex. In addition, the flatness which is a ratio of the long diameter / short diameter in the cross section of a flat ultrafine fiber is necessary in the point which obtains a fine groove | channel, Preferably it is 5 or more and 15 or less flatness. In particular, when the flatness is 4 or more and the pile is configured in a state where the flat surface is in contact with the pile, the pile yarn is hard to fall, thereby obtaining an alignment film having excellent orientation. In order to make it hard to fall the pile yarn formed of the flat ultrafine fiber, it is preferable to arrange | position a pile yarn so that the long diameter side of the flat surface of the flat ultrafine fiber may be parallel to a rubbing direction. For example, a multi-layer laminated composite fiber shown in FIG. 1 is used as a split composite fiber, and is a pile forming yarn (hereinafter also referred to as a "thread for pile") made of copper fiber, and has a twist number of 0 to 500 T / M. (Iii) Using a twisted yarn, such a pile thread is embedded in the fabric parallel to the warp yarn and pressed into the weft yarn to flatten the yarn for the pile, so that the flat surface (longer diameter side) of the split multi-layer laminated composite fiber is parallel to the weft yarn. Easy to lose When the yarn is divided and wound so that the circumferential direction of the rubbing roll becomes the inclined direction as the rubbing cloth, the flat surface of the flat ultrafine fibers tends to be parallel to the rubbing direction. Of course, even when the flat surface of the flat microfibers does not take special care to be parallel to the rubbing direction, the flat microfibers facing the rubbing direction of the flat microfibers to some extent are effectively effective. It acts to form a uniform micro groove.

Moreover, in this invention, the cross-sectional shape in which 5-20 layers, especially 7-15 layers of flat ultrafine fiber formation components are laminated | stacked is preferable so that the multilayer laminated composite fiber before division may contact a flat surface, and the multilayer laminated type before division | segmentation is preferable. As short fiber fineness of a composite fiber, 1-10 dtex is preferable. As the multilayer laminated composite fiber before the division, the cross-sectional shape in which the above flat cross-sectional fiber forming components are in contact with a plurality of flat surfaces is preferable, and in particular, the fact that the cross section of each flat ultrafine fiber forming component is substantially rectangular creates fine grooves. Preferred at

Moreover, as a pile, 40-500 dtex is preferable as a total fineness, and when pile height is 1.0-3.0 mm, especially 1.5-2.6 mm, a pile is hard to fall and it is preferable at the point that the alignment film excellent in the orientation is obtained. In addition, as pile density, the state in which 100,000-400,000 piles exist per 1 cm <2> of ground dough is preferable.

This flat ultrafine fiber is a multilayered composite fiber obtained by inducing two or more kinds of incompatible polymers into a multi-layer laminated state in a cross-sectional view of the fiber into a multi-layered lattice hole to form a multi-layer laminated composite fiber in a fiber state or as a pile fabric using the fiber. After that, it is obtained by performing division treatment by rubbing treatment, water jet treatment, air jet treatment, needle treatment, shirring treatment, alkali weight loss treatment, and solvent treatment such as benzoic acid or benzyl alcohol.

The incompatible polymer constituting the split composite fiber is a polymer having a dissolution parameter of 2 MJ / m ⁻³ or more. Specifically, as polymer A, polyethylene terephthalate, polybutylene terephthalate or copolyester mainly composed of these, polyester such as polylactic acid, and polymer B as nylon-6, nylon-66, nylon-610, semi-aromatic polyamide Polyamides such as ethylene or an ethylene-vinyl alcohol-based copolymer having an ethylene content of 20 to 50 mol% as the polymer A, and a polymer B formed by combining two or three or more selected from polyolefins such as polyethylene and polypropylene. It is preferable that it is easy to divide.

The weight ratio of the polymer A and the polymer B is preferably in the range of 4: 1 to 1: 4, and more preferably in the range of 3: 1 to 1: 3.

As a more preferable specific combination example of the polymer which forms a multilayer laminated composite fiber, a polyamide / polyester, polyester / ethylene-vinyl alcohol copolymer, polyester / polyolefin, polyamide / polyolefin, etc. are mentioned. Especially, the combination of polyamide / polyester is the most preferable. The dissolution parameter of the polymer constituting the composite fiber referred to herein is a parameter table (SP value table) of the polymer described on page 90 of the `` Plastic Data Book '' (issued December 1, 1999) issued by the Industrial Survey. Means the indicated value. About the polymer which is not shown in the SP value table, the dissolution parameter can be calculated | required from the calculated value of aggregation energy density.

Next, the heat-sealing composite fiber used for the ground paper of the rubbing cloth of this invention is demonstrated. The heat-sealing composite fiber used in the present invention is a polymer having a low melting point component containing a polymer having a melting point of 160 ° C. or lower and 80 ° C. or higher, and a polymer having a higher melting point than the low melting point component, and having a melting point of 200 ° C. or higher, and preferably a melting point of 240 ° C. It is composed of two kinds of different polymers of the above-mentioned high melting point components, and it can be set as the composite fiber which has a composite cross-sectional structure, such as a side-by-side type, a poncho type (concentric eccentric type, an eccentric eccentric type), an island-in-water type, a multilayer laminated type, Among them, the herbicidal type is preferable.

As a polymer which can be used for these heat-sealing composite fibers, the polyolefin type polymer represented by polyamide, polyester, and polypropylene, polyethylene, etc. which are represented by nylon etc. are mentioned, for example. Among these, as a combination of a low melting point component and a high melting point component, low melting point polyester / high melting point polyester, polyethylene / polypropylene, polyethylene / high melting point polyester, polypropylene / polyester, etc. are mentioned, for example.

In addition, in the present invention, it is important that the heat-sealing composite fiber has both heat-sealing properties and fiber properties such as strength, elongation and heat shrinkability even after fusion. Considering that the purpose of the heat-sealing composite fiber is to prevent the fall of the pile, and that the pile yarn is preferably a polyester / nylon composite fiber, from the viewpoint of the compatibility of the pile yarn and the ground yarn, low melting point polyester / high melting point polyester Is preferred. The use of polyhexamethylene terephthalate as the low melting point polyester component and polyethylene terephthalate as the high melting point component is particularly preferred because the texture hardens after fusion. As a ratio of the said low melting polymer which occupies for a heat-sealable composite fiber, 20 to 80 weight% is preferable.

If the low-melting polymer is less than 20% by weight, good heat sealability is hardly obtained. If the low-melting polymer is more than 80% by weight, it is not preferable because the fiberization processability such as radioactivity and stretchability is lowered.

As short fiber thickness of a heat-sealable composite fiber, 1-10 dtex is preferable. In the present invention, all of the fibers constituting the ground paper may be a heat sealable composite fiber, or a heat sealable composite fiber may be used as a part of the fiber constituting the ground paper. In the case of using as part of the fibers constituting the ground paper, in order to prevent omission of the pile yarn, at least 40% by weight of all the fibers constituting the ground paper are arranged at a predetermined interval on the warp and weft yarns. desirable.

Of course, in the present invention, if the pile yarn is to be further eliminated, an acrylic emulsion, a polyurethane emulsion, a rubber emulsion, a latex or the like may be coated on the ground paper.

In this invention, a conductive composite fiber can be used for ground paper. In the rubbing process, since the alignment film is rubbed with a rubbing cloth attached to a rubbing roller that rotates at a high speed, friction, contact, and peeling are repeated between the alignment film and the rubbing cloth, and static electricity is generated. Along with the damage, it absorbs various dusts generated during rubbing.

For this reason, the countermeasure against static electricity is very important. In Patent Document 1, as a countermeasure against static electricity, it is described to use a rubbing cross provided with conductivity to the brush layer (i.e., pile part). It is described to knead and spin an antistatic agent (carbon black or metal powder) when adding conductive fibers or spinning fine fibers. However, when the conductive fiber contained in the raising layer is not an ultrafine fiber, the conductive layer and the ultrafine fiber are mixed in the raising layer, that is, the pile surface, and of course, the frictional force between the alignment film is different, resulting in rubbing unevenness. On the other hand, in the ultrafine fiber in which the antistatic agent is kneaded, it is impossible in the manufacturing process to make the ultrafine fiber after the division into, for example, a core sheath-type composite fiber, so that the electrically conductive ultrafine fiber in Patent Document 1 means that the antistatic agent is uniformly kneaded. It is interpreted to mean ultrafine fibers. In this case, therefore, carbon black or fine metal powder is exposed to the surface of the ultrafine fibers. In addition, even if it is assumed that the fine fibers after division are composited, the pile yarn is cut after weaving, so that the cross-section of the pile yarn exposes the antistatic agent, and rubbing the alignment film with the fine fibers exposed to the antistatic agent causes contamination. This lowers the liquid crystal display quality.

The present inventors have found that the accumulated static electricity can be generated by corona discharge irrespective of conduction, so that it is not necessary to use the conductive fiber for the pile, but may be used for part of the ground, that is, the ground structure. As the conductive composite fiber, for example, a composite fiber in which a conductive layer made of a resin containing general conductive carbon (carbon black) is continuous in the longitudinal direction of the fiber can be used as the conductive agent used for the fiber. Since the neutralization by corona discharge, the electric resistance of the conductive composite fiber is preferably in the range of not more than 10 ⁵ Ω / ㎝ more than 10 ⁹ Ω / ㎝. It is preferable that the conductive carbon black contained in the conductive layer of the conductive composite fiber having such an electrical resistance has a specific resistance of 10 ⁻² to 10 ⁻³ Ω · cm. The electrical resistance referred to herein means that the fiber is cut into 10 cm, the conductive paint (dottite) is applied to the cut surface to fix the fiber end, and the end is used as an electrode to calculate the electric resistance at an applied voltage of 1 KV. The electrical resistance per one filament is.

In addition, as the conductive carbon (carbon black), as the conductive agent, carbon powder such as acetylene black, Ketjen black, PAN-based carbon, and pitch-based carbon, metallic powders such as aluminum, palladium, iron, copper, silver, fibers, and zinc oxide And metal compound powders such as tin oxide, titanium oxide, copper sulfide and zinc sulfide, and the like, and these may be used alone or in combination of two or more thereof.

When carbon black is used as the conductive agent, the electrical conduction mechanism of the resin containing the conductive carbon black may be due to the chain contact of the carbon black, the tunnel effect, or the like. You can think of it as Lord. Therefore, the longer the carbon chain and the higher the density of the carbon chain, the higher the contact probability is, thereby providing high conductivity. As a result of the present inventors' study, when the content of the conductive carbon black is less than 15% by weight, there is almost no conductive effect, and when the amount is 20% by weight, the conductivity is rapidly improved, and when it exceeds 30% by weight, the conductive effect is almost saturated. .

The conductive layer of the conductive composite fiber is composed of a conductive material such as conductive carbon black and a fiber-forming polymer.

An example of the cross section of the conductive composite fiber containing a conductive layer is shown in FIG. As for the conductive composite fiber 30 used for the rubbing cloth of this invention shown in the figure, the conductive layer 31 is not exposed to the fiber surface (fiber side), ie, the conductive layer 31 is a multilayer nonconductive polymer. A superconducting conductive composite fiber covered by a concealed polymer layer 32 and a protective polymer layer 33 as a layer, and in which no conductive layer is exposed on the fiber side, is a non-exposed type which can avoid the problem of contamination to the alignment film. .

As thickness of the electroconductive composite fiber used for the rubbing cloth of this invention, short fiber fineness is 5-20 dtex, Especially the range of 7-18 dtex is preferable.

In the rubbing cloth of this invention, as shown in FIG. 3, in order to conceal the black of conductive layers, such as carbon black, in aesthetics, it is set as the white (gray-white) concealed polymer layer which coats a conductive layer of a conductive composite fiber. It is preferable in appearance. The concealed polymer layer contains inorganic fine particles in the fiber-forming polymer, and the inorganic fine particles include concealed titanium dioxide, zinc oxide, magnesium oxide, aluminum oxide, silicon dioxide, barium sulfate, calcium carbonate, sodium carbonate, talc, kaolin, and the like. A white pigment or a white filler which has an effect is mentioned, These can be used 1 type or in combination or 2 or more types. Titanium dioxide and / or zinc oxide are preferable in consideration of the concealing effect, the whiteness as fabric, the sandability, and the processing characteristics. When the said inorganic fine particle is contained in about 10-50 weight% in the fiber forming polymer which forms a concealed polymer layer, and the thickness of a concealed polymer layer is adjusted, a concealment effect can be acquired. As a fiber forming polymer, what is illustrated as a polymer which forms an initial layer later can be used.

Moreover, it is preferable that the conductive composite fiber of the rubbing cloth of this invention coat | covers the said concealed polymer layer further with a fiber forming polymer (polymer), and forms a protective polymer layer. As a polymer which forms this protective polymer layer, the polyolefin type polymer represented by polyamide, polyester, and polypropylene, polyethylene, etc. which are represented by nylon etc. are mentioned, for example. In particular, it is preferable to select a polymer having compatibility with the low melting point component of the heat-sealable composite fiber so that the heat-sealing of the ground can be made firm, so that the pile yarn can be further improved.

The function of the protective polymer layer is to further protect the conductive layer and the concealment layer, and to further conceal the development of fiber strength as the ground yarn of the rubbing cloth, the blackness of the conductive layer, and the like for weaving into velvet fabric or the like as the conductive composite fiber. Etc. In addition, since the protective polymer layer is the outermost surface of the fiber, it is preferable to add titanium dioxide or the like used for ordinary synthetic fibers to the forming polymer to increase the texture of the fiber. In addition, various additives such as heat stabilizers, light stabilizers, antistatic agents, color pigments, and the like, which are usually used as addition of fibers, can be appropriately added to the concealed polymer layer and the protective polymer layer.

When the conductive composite fibers are formed in three layers as shown in Fig. 3, the composite ratio in the fiber cross section is determined by the maximum diameter of the conductive polymer layer 31, the concealed polymer layer 32, and the protective polymer layer 33, respectively. It is preferable that the relative ratio of the maximum thickness is a ratio of 1: 0.1 to 1: 0.5 to 2, with the maximum length of the conductive polymer layer 31 being 1 in view of the balance of conductivity, concealability, surface protection, and fiber performance.

For reference, the conductive composite fiber of the exposure type is shown in FIG. The conductive composite fiber 40 shown in the figure consists of the conductive layer 31 and the protective layer 41, and the conductive layer 31 is exposed to a part of fiber side surface. If such an exposure type conductive composite fiber is used, the conductive agent may be contaminated due to friction by the rubbing roll rotating at a high speed.

In the present invention, the conductive composite fibers are not used for pile yarns but are used for a part of ground yarns. In consideration of the friction caused by the rubbing roll rotating at high speed, the non-exposed type superconducting conductive composite fibers shown in FIG. It is to adopt.

Moreover, in order to prevent the loss of electroconductivity by the cutting | disconnection of electroconductive composite fiber, it is preferable to use conductive fibers in the state which bundled 2-6 pieces. Moreover, it is also preferable as a covering chamber which wound the conductive composite fiber in the circumference | surroundings of a nonelectroconductive yarn so that tension may not be applied to a conductive composite fiber as much as possible.

The conductive composite fiber is used in at least the radial direction or the upper direction of the paper tissue. 1 cm or more and 5 cm or less space | interval of ground paper in the state which collected the plurality of threads containing the said conductive composite fiber as mentioned above (it may be called "conductive yarn" hereafter), More preferably, 1 cm It is more than 4 cm and is used about one. The interwoven fabric into the branch structure may be used alone as a conductive yarn composed of only conductive composite fibers, may be integrated with other reinforcing fibers using a means such as interlacing, or may be a covering chamber as described above. It is suitable to weave 1 cm or more and 5 cm or less in the radial direction or the upper direction at the ratio of one conductive thread. If the interval between the conductive yarns to be incorporated is less than 1 cm, the cost is increased because the conductive composite fiber is expensive, and the antistatic performance is not particularly improved. On the other hand, when the intervening distance is 5 cm or more, sufficient antistatic effect is not obtained.

In the rubbing cloth of the present invention, the ground paper preferably has a density of 15 to 40 pieces / cm and a weft yarn of 20 to 50 pieces / cm. As thickness of a warp and a weft, the range of 50-300 dtex is preferable.

Next, the best form of the rubbing cloth of this invention is demonstrated. 2 is an enlarged cross-sectional schematic diagram of the rubbing cloth 10 according to the embodiment of the present invention.

The rubbing cloth 10 is a pile paper material composed of a pile 21 and a ground paper 22, and a part of the ground paper 22 is a conductive composite fiber 23, and the slope and weft of the ground paper. At least one of the heat-sealable composite fibers is incorporated. Further, the pile yarn is a flat ultrafine fiber made of a multilayer laminated split fiber having a flatness of 4 or more, preferably 5 or more, after the division into ultrafine fibers of 1.1 dtex or less. When the thickness exceeds 1.1 dtex, the effect of one file on the alignment film of the liquid crystal display element during the rubbing process is large, and the file length and the inclination angle become a problem, and it is difficult to obtain a uniform alignment effect.

As the pile paper material, a velvet, a moquette, or the like is preferable. There is no restriction on the ground yarn except that the conductive composite fibers are disposed at least in the radial direction or a part of the upper direction, and at least the heat-sealed composite fibers are used for the warp or weft yarns in the ground of the pile paper material. Can be used. However, when the ground yarn is cupline, there is a dimensional change due to the change in humidity, and therefore, exact humidity management is required when attaching it to storage, precision cutting, and rubbing roll. Since the required temperature-humidity management is easy, the polyester fiber which is good in dimensional stability with respect to temperature-humidity is especially preferable.

Since the rubbing cloth of this invention is a special cross section by a flat microfiber, a uniform and stable rubbing process can be performed. In addition, according to the rubbing cloth, it is not necessary to strictly manage the pile length and the inclination angle as in the prior art, so that handling is simple and uniform and fine grooves can be formed in the alignment film.

Further, in the rubbing cloth of the present invention, since the conductive composite fibers are disposed in part of the paper structure, static electricity caused by repeated friction, contact, and peeling between the alignment film and the rubbing cloth generated during rubbing is discharged by corona discharge. The damage of the circuit formed in the alignment film can be reduced, and the adsorption of dust generated by rubbing can be reduced.

In addition, when the heat-sealing composite fiber is used for at least the warp or weft of the rubbing cloth of the present invention, it is possible to omit the back coating for preventing the pile yarn from falling off, and the process is shortened, thus reducing the cost and yield. Is improved.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.

In addition, the flatness referred to in the present invention refers to the average value obtained by taking a photomicrograph of a fiber cross section, enlarging it, and determining the ratio of the long side to the short side for each of 50 fibers arbitrarily selected.

Example

Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.

Example 1

Using the pile yarns, warp yarns and weft yarns described below, the center paper cuts the velvet fabrics of the ground paper density of 70 pieces / inch (28 pieces / cm) and 69 pieces / inch (27 pieces / cm) respectively. I closed it.

File company

Of the polyester and the polymer B layer of the polymer A layer shown in FIG. 1 obtained by complex spinning using polyester (dissolution parameter = 22MJ / m 3) and nylon (dissolution parameter = 27MJ / m 3) in a weight ratio of 2: 1. A multi-filament (84dtex / 24 filament) having a twist number of 250 T / M made of a multi-layer laminated composite fiber (1) having a flat cross section shown in FIG. It was made into the form pile yarn, and it put in parallel with the inclination.

Ground slope

(1) Regular Polyester (84dtex / 72 Filament, Twist S800T / M)

(2) conductive composite fiber

As the conductive composite fiber shown in FIG. 3, nylon 6 containing 35% by weight of conductive carbon black was used as the conductive polymer layer 31, and 50 parts of titanium dioxide fine particles (average particle size 0.2 μm) were used as the concealed polymer layer 32. Nylon 6 containing% is used, and polyester containing 0.5 wt% of titanium dioxide is used as the protective polymer layer 33, and the composite ratio in the fiber cross section is the maximum diameter of the conductive polymer layer, the concealed polymer layer, and the protection. The ratio of the maximum thickness of each of the polymer layers was 1: 0.27: 1.03, and the 28 dtex / 2 filament obtained by complex spinning and stretching in a three-layered sheath type composite cross section consisting of a conductive polymer layer, a concealed polymer layer, and a protective polymer layer. The electroconductive composite fiber yarn (electrical resistance 3 * 10 <^{7> (} ohm) / cm * f) was woven in diagonally aligned from the rear of the loom in one ratio at 1.27 cm.

Ground weft

As a weft yarn, a heat-sealing composite fiber having a greeta ratio of 80: 20 obtained by using polyhexamethylene terephthalate having a melting point of 135 DEG C as a low melting ultrafine component and a polyester as a high melting core component (220dtex / 48 filament, twisting). Number S500T / M) was incorporated.

Subsequently, shirring was performed, and the division of the decanting, refining, and flat ultrafine fiber-forming pile yarns was carried out with an aim of a reduction ratio of 7% by alkali reduction processing with an aqueous sodium hydroxide solution. In addition, after brushing and drying, the heat-sealable composite fiber of the weft yarn is firmly fixed to the pile by heat treatment at 180 ° C, and the pile yarn by the flat microfiber is not easily detached from the cut surface cut to the designated size so that the baking process can be performed. Could be omitted. The pile of the obtained rubbing cloth was composed of ultrafine fibers having a fineness of 0.3 dtex and a flatness of 6, a pile length of 2 mm, and the flat ultrafine fibers were in contact with the divided surfaces. And 250,000 flat ultrafine pile fibers existed per 1 cm <2> of ground dough.

Using this rubbing cloth, rubbing was carried out at an indentation length of 0.2 mm and a rotational speed of 1500 rpm, and the surface state was observed using an atomic force microscope image. As a result, uniform and parallel grooves without irregularities were formed. Moreover, the high definition liquid crystal display device with few scratches by which the damage of the circuit by static electricity was reduced was obtained.

`` Comparative Example 1 ''

As the ultrafine split fibers, multifilament yarns (84dtex / 24 filaments) made of a composite fiber in which the cross section before the split was hollow radially and a total of 12 layers of polyester / nylon bonded alternately were used for the pile yarn. In this comparative example, the conductive polyester fibers are not woven into the ground paper and the heat-sealable composite fibers are not used. Instead, the regular polyester fibers (84 dtex / 72 filaments, twisted number S800T / M) are inclined and wefted. Weaving was carried out for use, followed by shearing, firing and refining, and the division of the pile yarn was carried out with an aim of a reduction rate of 7% by alkali reduction processing with an aqueous sodium hydroxide solution. Further, after brushing and drying, a back coating was performed using an acrylic emulsion to obtain a rubbing cloth.

As a result of rubbing under the same conditions as in Example 1, a sufficient orientation effect was not obtained. Moreover, in backing processing, since it is not a machine exclusively for a rubbing cloth, since various doughs and various colors are processed, some contamination was observed and the yield fell.

In this rubbing cloth, the fibers constituting the pile were ultrafine fibers of 0.27 dtex, with an average flatness of 1.8.

`` Comparative Example 2 ''

As the conductive composite fiber, as shown in Fig. 4, nylon 6 containing conductive carbon black is used as the conductive layer 31, nylon 6 is used as the protective polymer layer 41, and the conductive layer 31 is formed on the fiber surface. A partly exposed conductive composite fiber 40 (electrical resistance 2 × 10 ⁷ Ω / cm · f) of 28 dtex / 2 filaments of the so-called exposed type is mixed with the finely divided fibers having the same radial cross section as in Comparative Example 1, A rubbing cloth was produced in the same manner as in Comparative Example 1 except that the pile yarn was used at a ratio of 1.27 cm in one point.

As a result of the rubbing treatment as in Example 1, the conductive composite fiber used for the pile was thick with 28 dtex / 2 filament, causing scratches, and conductive carbon black from the conductive layer exposed on the surface of the conductive composite fiber due to the high speed rotation. The dropping out resulted in contamination. The orientation performance fell under the influence of the washing | cleaning process for removing this, and the quality of the liquid crystal display device fell.

The rubbing cloth of the present invention can be used for uniform and stable rubbing treatment for forming uniform and fine grooves in the alignment film.

In addition, since the rubbing cloth of the present invention uses a heat-sealed composite fiber at least for warp or weft yarn, the back coating for preventing the pile yarn from falling off can be omitted, and the rubbing can be reduced and the yield can be improved. It can be used for processing.

In addition, the rubbing cloth of the present invention in which conductive composite fibers are disposed on a part of the base structure has a static electricity generated by the corona discharge between the alignment film and the rubbing cloth generated at the time of rubbing, and the electrostatic discharge is removed by corona discharge. It can use for the rubbing process which can reduce the damage of the formed circuit and can reduce the adsorption | suction of the dust generate | occur | produced by rubbing.

Claims (3)

A rubbing cloth used to align an alignment film of a liquid crystal display device, wherein the rubbing cloth is composed of ground paper and pile yarns, and at least the slope and weft of the ground paper. The heat-sealing composite fiber is used in part, and the pile yarn is a flat ultrafine fiber of 1.1 dtex or less obtained by dividing the multilayer laminated composite fiber, and is composed of ultrafine fibers having a flatness ratio (long diameter / short diameter ratio) of 4 or more. A rubbing cloth characterized by the above-mentioned. The method of claim 1, The grounding paper contains the conductive composite fiber, and the conductive composite fiber has no conductive layer exposed on the fiber surface, and has a conductive performance of 10 ⁵ to 10 ⁹ Ω / cm per filament. The method of claim 2, A rubbing cloth in which conductive composite fibers formed by applying a concealed polymer layer to the outer circumference of the conductive layer of the conductive composite fibers are used.

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