TWI393811B - Rubbing cloth - Google Patents

Description

Rubbing cloth

The present invention relates to a rubbing cloth used in the process of controlling the alignment of liquid crystal molecules in a manufacturing process of a liquid crystal display device.

In a liquid crystal display device, liquid crystal molecules are aligned along a fine groove by generating fine grooves in an alignment film to define alignment of liquid crystal molecules. The process of forming the fine groove on the alignment film refers to a rubbing treatment process in which the alignment film is rubbed with a raised cloth attached to the rotary roll. The raised fabric used here is called a rubbing cloth, and the raw material is currently used as a thunder, cotton, or the like.

The Thunder friction cloth is a base yarn using a copper amine thunder, and a velvet fabric in which a general thunder is a raised yarn is used. After the weaving, we perform the shearing treatment, and after the desizing and scouring treatment, in order to ensure the stability of the raising, the cellulose-reactive resin is used for the resin processing, and the vinyl acetate-based resin or the acrylic resin is used to prevent the pilling from falling off. The coating processing is carried out inside.

Moreover, in the case of a cotton cloth, after removing the paraffin component or the inclusion contained in the cotton itself after the weaving, the scouring and bleaching treatment are performed, and the hair cutting treatment is performed. In the case of a cotton cloth, since it is not straight-like when it is recovered by a convolution action on a single fiber, it is not possible to carry out a resin processing treatment by a cellulose-reactive resin in order to stabilize the raising. In general, for the Thunder system, it is called W-wool yarn, and when the three weft yarns are clamped into the raised yarn, the cotton maker is called the V-pilling yarn, and since the one yarn is pushed into the pile yarn, the pile yarn is easily detached. The construction must be fully covered by the rear cover.

In general, the friction treatment of a general thunder or cotton rubbing cloth is used, and since the length, inclination angle or density of the fleece of the rubbing cloth is not uniform, the frictional force is inconsistent to the alignment film, so the alignment of the alignment film The force is not uniform, which causes the display quality of the liquid crystal display panel to decrease. In the case of a raised yarn formed of a general ultrafine fiber, there is a case where the repulsive force is lowered and the frictional force is insufficient and the alignment is difficult.

Further, in the rubbing treatment, when the alignment film is wiped by the rubbing roller rotating at a high speed, static electricity is generated when rubbing, contact, and peeling are repeated.

This static electricity causes damage to the circuit on the glass substrate, resulting in defective liquid crystal display. Further, the rubbing cloth is attached to the metallic roll via the double-sided tape, and when the base of the raised fabric is a cellulose-based fiber, it is stretched by humidity. In other words, stretching is performed under high humidity and shrinking is performed under low humidity. Therefore, the precise cutting, storage, and attachment of the rubbing cloth to the friction cloth must have strict humidity management problems.

In addition, in order to improve the liquid crystal display accuracy, it is proposed to use a rubbing cloth having a raised portion made of an ultrafine fiber of 1.1 dtex or less (see Patent Document 1). However, the ultrafine fiber specifically described in the patent document 1 is a microfiber having a fan-shaped cross section in which the composite spun fiber having a hollow-radial cross section is divided, and the inventors have found that the same ultrafine fiber is used for the rubbing treatment. Most of them produce poor alignment. The reason is the ultrafine fiber described in Patent Document 1, and the ultrafine fibers constituting the pile yarn are not sufficiently stiff and are easily collapsed. As a result, even if it has ultrafine fibers, it does not change, and the quality feeling by using the ultrafine fibers cannot be produced.

Further, during the rubbing treatment, friction, contact, and peeling treatment are repeatedly performed between the rubbing cloth and the alignment film which are rotated at a high speed, and static electricity is generated and the circuit on the glass substrate is damaged to cause a liquid crystal display. Therefore, in order to prevent the above, Patent Document 1 discloses that at least the raised layer of the felt is electrically conductive in order to prevent static electricity during the rubbing treatment. Next, a specific method of imparting electrical conductivity is proposed as a method of kneading an electroforming agent such as carbon black or a fine metal powder during spinning of ultrafine fibers. However, when the conductive fiber in which the electrification agent is kneaded in the raised yarn is used, the velvet fabric or the pile fabric may have an electric charge of carbon black or metal powder exposed on the surface or the cross section of the raised yarn. When the pulverizing yarn exposed by the electrification agent is subjected to the rubbing treatment of the alignment film, the cause of the contamination is formed, resulting in a poor liquid crystal display device.

In addition, in order to avoid the micro-dust caused by the above-mentioned conductive material wiping. In the case of foreign matter, the proposal consists of a sheath made of a conductive material and covered with a non-conductive material of the core. In the conjugate fiber of the core structure, the rubbing cloth of the conductive material is not substantially exposed on the rubbing surface (see Patent Document 2).

Secondly, the specific form is proposed to start the wool yarn from the above sheath. A composite fiber of a core structure is formed to form a rubbing cloth of an annular raised yarn in which the raised yarn is not cut.

However, the rubbing cloth described in Patent Document 2 uses a sheath. The conductive composite fiber of the core structure is not able to make the raised yarn extremely fine as the raised yarn, and it is difficult to perform fine alignment treatment on the alignment film. In other words, the sheath. When the conductive composite fiber of the core structure is used as a conductive material of a core, conductivity of a fiber such as a metal fiber, a surface metallized fiber, a carbon black fiber, or a conductive ceramic fiber, or a carbon black powder or a metal powder is used. The powder is kneaded in a resin to form a fiber or the like obtained by spinning, and a coating material made of a resin such as polyester, acrylic or polyamide is coated as an outer layer, and the single fiber fineness of the obtained conductive composite fiber is about 5~20dtex, which can't make fine fineness. It is a very thick raised yarn for the fineness of the general rubbing cloth (1.1~3.3dtex). Some parts will have friction spots and strips when used. It is impossible to form an unequal electric field and it is impossible to perform corona discharge treatment.

In addition, since the front end of the raised yarn has no acute angle and is an annular pilling yarn, the friction effect is reduced. Further, when there is no proposal that the conductive material is black, a shield layer which shields black and forms white or off-white is provided.

Further, in Patent Document 1, it is described that, in order to prevent the fluffing portion of the rubbing cloth from falling off, the vinyl acetate-based or acrylic-based resin is subjected to a coating process in the inside, but when a new process called coating processing is performed, the entire rubbing cloth is used. The manufacturing process becomes longer, which not only increases the cost, but also increases the processing disadvantages such as pollution during the process.

As described above, there has been no conventionally proposed structure for raising a very fine fineness of a liquid crystal display having a high frictional effect, or a rubbing cloth which can solve problems such as contamination by a conductive agent and high cost.

Patent Document 1: JP-A-2005-91899, Patent Document 2: JP-A-2007-232938

The present invention has been made in view of the above circumstances, and provides a fine yarn which is formed by the length of the raised yarn, the inclination angle, and the uniformity of the density, and which is composed of ultrafine fibers having a special cross section. The uniform alignment is not limited to the antistatic measures of the conductive fibers, the reduction of the contamination, and the excellent rubbing cloth which can omit the coating process.

In order to solve the above problems, the inventors of the present invention have further intensively studied and found that by using a very fine fiber having a special cross section as a raised yarn of a rubbing cloth, a display element having extremely poor alignment property can be obtained, and can be omitted by The present invention is completed by using a heat-fusible composite fiber to perform a substrate backing process by using a conductive composite fiber having no conductive layer to be exposed to obtain a friction cloth having improved yield.

In other words, the present invention provides (1) a rubbing cloth which is used for a rubbing cloth for aligning an alignment film of a liquid crystal display device, which is composed of a ground base and a raised yarn. The heat-fusible composite fiber is used for at least a part of the warp yarn and the weft yarn of the base, and the raised yarn is a flat ultrafine fiber of 1.1 dtex or less obtained by dividing the multi-layer laminated type composite fiber, that is, an aspect ratio (long diameter/short length) (2) The rubbing cloth according to the above 1, wherein the conductive composite fiber is contained in the base, and the conductive layer of the conductive composite fiber is not exposed from the surface of the fiber, and The conductive property is 10 ⁵ to 10 ⁹ Ω/cm per one single yarn, and (3) the rubbing cloth according to the above (2), which is formed by using a shielding polymer layer on the outer periphery of the conductive layer of the conductive composite fiber. Conductive composite fiber.

In the rubbing cloth of the present invention, the ultrafine fibers used in the fleece yarn of the rubbing fabric are the fiber-forming polymer (as defined in "polymer" and "polymer" in the present invention) A, and The flat ultrafine fiber obtained by the split type composite fiber having a multi-layer laminated special cross-sectional shape, which is an aggregate of the flat ultrafine fiber forming component formed of the fiber-forming polymer B which is incompatible with the polymer A, is formed after the division. Each is a flat ultrafine fiber of polymer A and polymer B. When the single fiber fineness of the flat ultrafine fiber is 1.1 dtex or less, it is preferable to obtain a uniform display element having no strip shape, preferably in the range of 0.1 to 1.1 dtex, more preferably in the range of 0.2 to 0.5 dtex. Further, in the case of a fine groove, the flatness of the ratio of the long diameter to the short diameter on the cross section of the flat ultrafine fiber must be 4 or more, and preferably a flatness of 5 or more and 15 or less. In particular, when the bristles are formed in a state in which the flatness is 4 or more and the flat faces are connected, an aligning film in which the bristles are not easily collapsed and the alignment property is excellent can be obtained. In order to prevent the raised yarn formed of the flat ultrafine fibers from collapsing, it is preferable to arrange the raised yarn so that the long diameter side of the flat surface of the flat ultrafine fibers is parallel to the rubbing direction. For example, a multi-layer laminated type composite fiber as shown in Fig. 1 is used as a split type composite fiber, and a low twist yarn having a number of turns of 0 to 500 T/M is used as a pile forming yarn formed of the same fiber (hereinafter also referred to as "Fleeting yarn", which causes the raising yarn to be wefted in parallel with the warp yarn and attached to the weft yarn, which is easy to flatten the raising yarn and make the flat surface of the split multi-layer composite fiber (long diameter) Side) parallel to the weft yarn. When the yarn is divided into a rubbing cloth and the winding process is performed in the warp direction in the circumferential direction of the rubbing roll, the flat surface of the flat ultrafine fiber is likely to be parallel to the rubbing direction. Of course, there is no need to specifically consider that the flat surface of the flat microfiber is parallel to the rubbing direction. Regardless of the number of flat microfibers, the flat surface will naturally be parallel to the rubbing direction, and the flat microfibers in this direction can work effectively to form a uniform fineness. ditch.

Further, in the multi-layer laminated type composite fiber before division in the present invention, the cross-sectional shape of the flat ultrafine fiber forming component of the lower layer of 5 to 20 layers (particularly 7 to 15 layers) is preferably connected to the flat surface, and then, before the division. The single fiber fineness of the multi-layer laminated type composite fiber is preferably from 1 to 10 dtex. The multi-layer laminated type composite fiber before the division is preferably a cross-sectional shape in which the flat cross-section fiber forming component is connected to a plurality of flat faces, and in particular, the cross-section of each flat ultrafine fiber forming component is about a rectangular groove. Preferably.

Moreover, the total fineness of the raised yarn is preferably 40 to 500 dtex, and the height of the raised yarn is 1.0 to 3.0 mm, particularly 1.5 to 2.6 mm, so that the yarn is not easily collapsed and the alignment film having excellent alignment property is obtained. good. Further, the raised yarn density is preferably in the state of having 100,000 to 400,000 raised yarns per 1 cm ^{2 of the} substrate texture.

The flat-type ultrafine fiber can be obtained by multi-layer laminated type composite fiber obtained by composite spinning of two or more kinds of incompatible polymers when they are observed in a cross section of the fiber, and is introduced into a spinning nozzle hole in a multi-layer laminated state. After the state or the formation of the raised fabric using the fiber, the enthalpy treatment, the water jet treatment, the air jet treatment, the kneading treatment, the shearing treatment, the alkali reduction treatment, the separation treatment by solvent treatment such as benzoic acid or benzyl alcohol are obtained. .

The incompatible polymer constituting the split type composite fiber is a polymer having a solubility parameter of 2 MJ/m ^-3 or more. Specifically, polyethylene terephthalate, polybutylene terephthalate or a polyester such as copolymerized polyester or polylactic acid mainly as the polymer A, and the dragon 6 and the nylon 66 are used. Polyamine, such as Nylon 610, semi-aromatic polyamine, as polymer B; or ethylene-vinyl alcohol copolymer having an ethylene content of 20 to 50 mol% as polymer A, in combination of two or three The polyolefin selected from the group consisting of polyethylene and polypropylene is preferably formed as the polymer B, and is preferably easily divided.

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

More specific specific examples of the polymer forming the multi-layer laminated type composite fiber, such as polyamine/polyester, polyester/ethylene-vinyl alcohol copolymer, polyester/polyolefin, polyamine/polyolefin, and the like. Among them, it is more preferable to combine polyamine/polyester. The dissolution parameter of the polymer constituting the composite fiber referred to herein refers to the parameter table of the polymer (SP value table) described on page 90 of the "Plastic Handbook" issued by the Industrial Investigation Association (issued on December 1, 1999). ) The value shown. Regarding the polymer not shown in the SP value table, the dissolution parameter can be obtained by calculating the density of the agglomerated energy.

Next, the heat-fusible composite fiber used in the base of the rubbing cloth of the present invention will be described. The heat-fusible composite fiber used in the present invention is a low-melting 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 component, and having a melting point of 200 ° C or higher. (better than 240 ° C or higher), the high melting point component is composed of two different polymers, and may have a side-by-side type, a core-sheath type (concentric core sheath type, eccentric core sheath type), A composite fiber having a composite cross-sectional structure such as an island type, a multi-layer laminate type or the like, wherein a core-sheath type is preferred.

The polymer which can be used for such a heat-fusible composite fiber is, for example, a polyamide-based polymer which is typically polyamine, polyester, polypropylene, polyethylene or the like which is typical of Nike. Among these, a combination of a low melting point component and a high melting point component, for example, a low melting point polyester/high melting point polyester, a polyethylene/polypropylene, a polyethylene/high melting point polyester, a polypropylene/polyester, and the like.

Further, in the present invention, it is important that the heat-fusible composite fiber has both thermal fusion properties, fiber properties after welding, tensile strength, and heat shrinkability. The purpose of the heat-fusible composite fiber is to prevent the pilling yarn from falling off. When the polyester yarn/resistant nylon composite fiber is suitable for the wool yarn, the low melting point polyester/high melting point is used for the compatibility of the wool yarn and the base yarn. Polyester is preferred. Next, in the case where polyhexamethylene terephthalate is used as the low-melting polyester component and polyethylene terephthalate is used as the high-melting component, the texture is hard to be hardened after the fusion, and therefore it is more preferable. The proportion of the above-mentioned low melting point polymer which is contained in the heat-fusible composite fiber is preferably from 20 to 80% by weight.

When the low-melting-point polymer is less than 20% by weight, it is difficult to obtain good thermal fusion properties, and when it is more than 80% by weight, the fiberizing processability such as spinning property and elongation may be lowered, which is not desirable.

The single-fiber thickness of the heat-fusible composite fiber is preferably from 1 to 10 dtex. In the present invention, the fibers constituting the entire base may be heat-fusible composite fibers, or the fibers constituting a part of the base may be heat-fusible composite fibers. When a fiber constituting a part of the base is used, and the warp yarn and the weft yarn are disposed at a predetermined interval, and 40% by weight or more of all the fibers constituting the base are heat-fusible composite fibers, it is preferable to prevent the pilling yarn from falling off.

Of course, in the present invention, when the wool yarn is detached from the upper layer, the base may be coated with an acrylic emulsion, a polyurethane emulsion, a rubber emulsion or a latex.

The present invention can use conductive composite fibers in a substrate. In general, the rubbing treatment is performed by rubbing the alignment film with the rubbing cloth attached to the rubbing roller which is rotated at a high speed, and the rubbing, contact, and peeling treatment are repeated between the alignment film and the rubbing cloth to generate static electricity and the glass substrate is generated. The circuit on the upper side is damaged, and at the same time, various dust generated during friction is absorbed.

Therefore, the antistatic countermeasures are extremely important. In the prior art, the rubbing cloth having a fusible layer (that is, the raised portion) having conductivity is used as a countermeasure against static electricity, and it is described that conductive fibers are added to the raised layer or the ultrafine fibers are subjected to The spinning electric agent (carbon black or metal powder) is spun at the time of spinning as a specific countermeasure. However, when the conductive fibers contained in the batt layer are not ultrafine fibers, the fusible layer (i.e., the raised surface) is mixed with the conductive fibers and the ultrafine fibers, and of course, the frictional force between the aligning films and the alignment film is different to form a rubbing spot. In addition, the ultrafine fibers having a chargeable agent are kneaded, and since it is impossible to have the fine fibers (for example, the core-sheath type composite fibers) after the division in the manufacturing process, the conductive ultrafine fibers of Patent Document 1 can be understood to have a uniform kneading. Very fine fiber of the electric charge agent. However, at this time, carbon black or metal fine powder is exposed on the surface of the ultrafine fibers. Further, even if it is assumed that the ultrafine fibers after the division are composited, since the raised yarn is cut after the weaving, the electric charge is exposed in the cross section of the raised yarn, and the fine fibers exposed by the electric charge are rubbed. When the alignment film is used, it causes contamination and reduces the quality of the liquid crystal display device.

The present inventors have found that the static elimination treatment of the accumulated static electricity is not performed by conduction, but can be treated by corona discharge, so that it is not necessary to use conductive fibers in the raised yarn, and it can be in a part of the substrate (ie, texture). use. When the conductive composite fiber is, for example, a conductive agent used in a fiber, 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. In order to remove electricity by corona discharge, the electric resistance of the electroconductive composite fiber is preferably in the range of 10 ⁵ Ω/cm or more and 10 ⁹ Ω/cm or less. It is preferable that the conductive carbon black contained in the conductive layer of the conductive composite fiber having electric resistance has a characteristic resistance of 10 ^-2 to 10 ^-3 Ω/cm. The electric resistance referred to here is that the fiber is cut into 10 cm and the conductive coating is coated on the cut surface (Dotite) )), after fixing the fiber end portion, the end portion was used as an electrode, and the electric resistance per one single yarn of the electric resistance of 1 KV was obtained.

Further, the conductive agent is the above-mentioned conductive carbon (carbon black), for example, carbon powder such as acetonitrile carbon black, ketjen black, PAN-based carbon, pitch-based carbon, aluminum, palladium, iron, copper, or the like. A metal powder or a fiber such as silver, a metal compound powder such as zinc oxide, tin oxide, titanium oxide, copper sulfide or zinc sulfide may be used alone or in combination of two or more.

When carbon black is used as the conductive agent, it is considered that the electric conduction mechanism of the resin containing the conductive carbon black is a contact by a carbon black chain, and a tunnel effect or the like is generally considered mainly. Therefore, in the case where the carbon black chain is long or is present in a resin at a high density, the contact accuracy is increased and high conductivity is imparted. As a result of the review by the present inventors, when the content of the conductive carbon black is less than 15% by weight, the conductive effect is almost completely absent, and when the content is 20% by weight, the conductivity rapidly increases, 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. 3. The conductive composite fiber 30 used in the rubbing cloth of the present invention shown in the figure is such that the conductive layer 31 is not exposed on the fiber surface (fiber side), that is, the conductive layer 31 is used as a plurality of layers of the non-conductive polymer layer. The sheath-type conductive composite fiber in which the shield polymer layer 32 and the protective polymer layer 33 are coated and has no conductive layer exposed on the side surface of the fiber can prevent the non-exposure type of the problem of contamination of the alignment film.

The thickness of the conductive composite fiber used in the rubbing cloth of the present invention is preferably in the range of 5 to 20 dtex, particularly 7 to 18 dtex.

In the rubbing cloth of the present invention, as shown in Fig. 3, the black color of the conductive layer such as carbon black is shielded, and the white (off-white) shielding polymer layer of the conductive layer is coated in the conductive composite. The appearance of the fiber is preferred. The barrier polymer layer contains inorganic fine particles in the fiber-forming polymer, such as titanium dioxide, zinc oxide, magnesium oxide, aluminum oxide, cerium oxide, barium sulfate, calcium carbonate, sodium carbonate, talc, kaolin, and the like. A white pigment or a white filler which is a barrier effect may be used alone or in combination of two or more. Titanium dioxide and/or zinc oxide are preferred in view of the shielding effect, the whiteness of the fabric, the yarn-making property, and the processing characteristics. The fiber-forming polymer forming the barrier polymer layer contains about 10 to 50% by weight of the above-mentioned inorganic fine particles, and when the thickness of the barrier polymer layer is adjusted, a shielding effect can be obtained. As the fiber-forming polymer, those which form the sheath-forming polymer described below can be used.

Further, in the conductive conjugate fiber of the rubbing cloth of the present invention, in addition to the above-mentioned barrier polymer layer, a protective polymer layer coated with a fiber-forming polymer (polymer) is preferably provided. The polymer which forms the protective polymer layer is, for example, polyamine, a polyester represented by Nail, etc., and a polyolefin-based polymer typified by polypropylene, polyethylene, or the like. In particular, when a polymer having compatibility with the low melting point component of the heat-fusible composite fiber is selected and the base is strongly thermally welded, the falling of the raised yarn can be further improved, which is more preferable.

As a function of protecting the polymer layer, in order to further protect the conductive layer and the shielding layer, and to be a conductive composite fiber when woven into a velour fabric or the like, and to have a fiber strength as a base yarn of the rubbing cloth, the black color of the conductive layer Wait for more shielding. Further, since the protective polymer layer is the outermost surface of the fiber, titanium dioxide or the like used for adding a general synthetic fiber to the formed polymer is preferred to improve the texture of the fiber. Further, various additives such as a thermal stabilizer, a photosetter, an antistatic agent, and the like which are generally added to the fiber, or a coloring pigment, etc., may be appropriately added to the barrier polymer layer and the protective polymer layer as needed.

When the conductive composite fiber is formed in three layers as shown in Fig. 3, the composite ratio of the fiber cross-section is the relative ratio of the longest diameter of the conductive polymer layer 31, the maximum thickness of each of the barrier polymer layer 32, and the protective polymer layer 33. In terms of conductivity, shielding property, surface protection property, and balance of fiber properties, when the maximum length of the conductive polymer layer 31 is 1, the ratio of 1:0.1 to 1:0.5-2 is preferable.

For reference, the exposed conductive composite fiber is as shown in Fig. 4. In the conductive composite fiber 40 shown in the same figure, a part of the conductive layer 31 made of the conductive layer 31 and the protective layer 41 is exposed on the side surface of the fiber. When the exposed conductive composite fiber is used, friction by a friction roller that rotates at a high speed may cause contamination of the conductive agent.

In the present invention, the conductive composite fiber is not used in the raised yarn, but is used in a part of the base yarn, but when it is considered to be rubbed by the friction roller which rotates at a high speed, in the case of preventing contamination, the use of FIG. 3 is adopted. A non-exposed sheath-type conductive composite fiber is shown.

Further, the conductive fibers are used in a state in which 2 to 6 bundles are bundled, and it is preferable to prevent the conductivity from disappearing by cutting the conductive composite fibers. Further, it is preferable that the conductive conjugate fiber is used as the coated yarn wound around the non-conductive yarn, and it is not necessary to apply tension to the conductive conjugate fiber as much as possible.

The above-mentioned conductive composite fiber is used in at least the warp direction or the weft direction of the texture structure. The yarn containing the conductive conjugate fiber is arranged in a plurality of bundled states (hereinafter referred to as "conductive yarn") as described above, and is spaced apart from each other by 1 cm or more and 5 cm or less (preferably 1 cm or more and 4 cm). The following) is used. The textured yarn formed of the conductive composite fiber may be used alone in the texture structure, or may be integrated with other reinforcing fibers by a method such as interlacing, and may be used as a covered yarn as described above. . It is preferable that one conductive yarn is woven in the warp direction or the weft direction at a ratio of 1 cm or more and 5 cm or less. When the woven fabric of the conductive yarn is less than 1 cm apart, the conductive composite fiber is expensive, which leads to an increase in cost, and in particular, does not improve the static elimination performance. Further, when the weaving interval is 5 cm or more, a sufficient static elimination effect cannot be obtained.

In the rubbing cloth of the present invention, the weaving density of the substrate is preferably 15 to 40 strips/cm of warp yarns and 20 to 50 strips/cm of weft yarns. The thickness of the warp and weft yarns is preferably in the range of 50 to 300 dtex.

Next, the best form of the rubbing cloth of the present invention will be explained. Fig. 2 is a view showing an enlarged cross-sectional view of the rubbing cloth 10 according to an embodiment of the present invention.

The rubbing cloth 10 is a fluffy fabric made of the raised yarn 21 and the base 22, and a part of the base 22 is woven with the heat-fusible composite fiber in at least one of the conductive composite fiber 23 and the warp and the weft of the base. Further, the raised yarn is a flat ultrafine fiber made of a microfiber of 1.1 dtez or less, a multi-layered laminated fiber having a flatness of 4 or more after division, and preferably 5 or more. When the thickness is greater than 1.1 dtex, one of the raised yarns in the rubbing treatment is greatly affected by the alignment film of the liquid crystal display element, and there is a problem in the length of the raising or the inclination angle, and it is difficult to obtain a uniform alignment effect.

The above-mentioned raised base fabric is preferably velvet, pile fabric or the like. The substrate of the raised yarn fabric is provided with a conductive composite fiber in at least a part of the warp direction or the weft direction, and at least a heat-fusible composite fiber is used in the warp or weft yarn, and the substrate is not limited, and can be used generally. Raw materials. However, when the base is a copper amine fiber, due to dimensional changes due to humidity changes, it is necessary to have strict humidity management for storage, precision cutting, and attachment to a friction roller. In terms of the required temperature and humidity management, it is particularly preferable to use a polyester fiber having a good dimensional stability for temperature and humidity.

In the rubbing cloth of the present invention, since the fleece yarn has a special cross section by the flat ultrafine fibers, the rubbing treatment can be performed uniformly and stably. Then, with the rubbing cloth, it is not always necessary to strictly manage the length or the inclination angle of the pile yarn as in the prior art, and the fine groove can be uniformly generated on the alignment film by a simple treatment.

Further, in the rubbing cloth of the present invention, since a conductive conjugate fiber is disposed on a part of the texture structure, static electricity generated by friction, contact, and peeling between the aligning film and the rubbing cloth during rubbing can be repeatedly performed, and the coring discharge is used to remove electricity. And reduce the damage of the circuit disposed on the alignment film, and reduce the phenomenon of dust adsorption generated during friction.

Further, when the heat-fusible composite fiber is used for at least the warp yarn or the weft yarn of the rubbing cloth of the present invention, the subsequent coating treatment can be omitted to prevent the fleece yarn from falling off, and the process can be shortened, and the cost can be reduced and the yield can be improved.

In the following, the invention will be specifically described by way of examples, but the invention is not limited by the following examples.

Further, the flatness referred to in the present invention refers to a microscope photograph of a cross section of a photographed fiber, which is enlarged and arbitrarily selected from 50 fibers, and the average value of the ratio of the long side to the short side is obtained.

[Examples]

Next, the invention will be described in more detail by way of examples, but the invention is not limited by the examples.

Example 1

Using the raised yarn, the warp yarn, and the weft yarn described below, the velvet fabric having a base density of 70 strips/twist (28 strips/cm) and 69 strips/twist (27 strips/cm) was center-cut and Rolling.

The raised yarn was subjected to a composite spinning treatment using a polyester (dissolving parameter = 22 MJ/m ³ ) and a nylon (dissolving parameter = 27 MJ/m ³ ) in a weight ratio of 2:1, and the obtained polymerization as shown in Fig. 1 was obtained. The polyester of the layer A and the layer of the polymer B layer are bonded to each other in the transverse direction and laminated in a multi-layered layer of 11 layers, and the number of turns of the multi-layer laminated type composite fiber 1 of the flat section shown in Fig. 1 A composite yarn of 250 T/M (84 dtex/24 single yarn) is used as a flat ultrafine fiber-forming raised yarn, and is beaten in parallel with the warp yarn.

Base warp yarn (1) Regular yarn polyester (84dtex/72 single yarn, number of turns S800T/M) (2) Conductive composite fiber The conductive composite fiber shown in Fig. 3 is made of 35 wt% conductive carbon black. As the conductive polymer layer 31, Nylon 6 containing 50% by weight of titanium dioxide fine particles (average particle diameter of 0.2 μm) was used as the barrier polymer layer 32, and polyester containing 0.5% by weight of titanium oxide was used as the protective polymer layer. 33, the ratio of the composite cross-section of the fiber is the ratio of the maximum length of the conductive polymer layer, the maximum thickness of the shielding polymer layer, and the protective polymer layer to a ratio of 1:0.27:1.03, in the conductive polymer layer, Conductive composite fiber yarn of 28dtex/2 single yarn obtained by composite spinning and stretching of the three-layer core-sheath composite cross section formed by shielding the polymer layer and the protective polymer layer (resistance 3×10 ⁷ Ω/cm.f ), weaving in the direction of the warp yarn from the rear of the loom in a ratio of 1.27 cm.

The base weft yarn is a heat-fusible composite fiber with a core sheath ratio of 80:20 obtained by using a polyhexamethylene phthalate having a melting point of 135 ° C as a low-melting sheath component and a general polyester as a high melting core component (220 dtex/48). The single yarn, the number of turns S500T/M) is woven into the weft yarn.

Next, the shearing treatment, the desizing, the scouring treatment, and the division of the flat ultrafine fiber-forming hair-creating yarn were carried out, and the alkali reduction processing was performed by the aqueous sodium hydroxide solution to achieve the target of a reduction rate of 7%. In addition, after the bristles are treated and dried, the heat-fusible composite fibers of the weft yarns are firmly adhered by the heat treatment at 180 ° C, so that the raised yarns formed of the flat ultrafine fibers are not easily cut into the cuts of the specified size. The surface is peeled off and the reinforcement treatment can be omitted. The obtained raised yarn of the rubbing cloth was composed of ultrafine fibers having a fineness of 0.3 dtex and a flatness of 6, and the length of the raised yarn was 2 mm, and the flat ultrafine fibers were connected to the divided surface. Next, there are 250,000 flat fine hair raising fibers in the texture of the substrate per 1 cm ² .

Using this rubbing cloth, rubbing treatment was carried out with a length of 0.2 mm and a turning speed of 1,500 rpm, and when the surface state was observed by an atomic force microscope image, grooves having no spots and being uniformly parallel were formed. In addition, a high-definition liquid crystal display device with reduced circuit damage and less scratches due to static electricity can be obtained.

<Comparative Example 1>

As the finely divided fiber, a composite yarn (84 dtex/24 single yarn) made of a composite fiber having a hollow radial shape, a polyester/Nylon interaction, and a total of 12 layers was used for the plucking yarn. In this comparative example, the conductive composite fiber was not woven into the substrate, and the heat-fusible composite fiber was not used, and the regular polyester fiber (84 dtex/72 single yarn, number of turns S800T/M) was used for the weaving of the warp yarn and the weft yarn. Then, the shearing treatment, the desizing, and the scouring treatment were carried out, and the division of the crepe yarn was subjected to alkali reduction processing by the aqueous sodium hydroxide solution, and the target of the reduction rate of 7% was achieved. Then, after the bristles were treated and dried, the acrylic coating was used for the back coating treatment to obtain a rubbing cloth.

When the rubbing treatment was carried out under the same conditions as in Example 1, a sufficient alignment effect could not be obtained. In addition, when the reinforcing work is performed, not only the special machine for the rubbing cloth but also various textures and various colors are processed, and as a result, there is a case where the contamination is slightly contaminated and the yield is not good.

The rubbing cloth was an ultrafine fiber having a fiber of 0.27 dtex constituting the pile yarn, and the average flatness was 1.8.

<Comparative Example 2>

In the conductive composite fiber, the conductive layer 31 containing the conductive carbon black shown in Fig. 4 is used as the conductive layer 31, and the same resistant nylon 6 is used as the protective polymer layer 41, and a part of the conductive layer 31 is exposed on the surface of the fiber. The conductive composite fiber 40 (resistance 2 × 10 ⁷ Ω/cm.f) of the exposed type 28 dtex/2 single yarn and the extremely finely divided fibers of the same radial cross section as in Comparative Example 1 were mixed, each of which was A rubbing cloth was produced in the same manner as in Comparative Example 1, except that the ratio of 1.27 cm was used for the raised yarn.

When the rubbing treatment was carried out in the same manner as in Example 1, the conductive composite fiber used in the raised yarn was 28 dtex/2 single yarn, which was too thick and scratched, and the conductive carbon black was exposed to electric conductivity by high-speed rotation. The conductive layer on the surface of the composite fiber woven fabric falls off, causing a contamination situation. Affected by the cleaning process for removing the object, the alignment performance is lowered, and the quality of the liquid crystal display device is lowered.

[Utilization value of industry]

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

Further, in the rubbing cloth of the present invention, since at least the heat-fusible composite fiber is used for the warp yarn or the weft yarn, the post-coating treatment for preventing the fleece yarn from falling off can be omitted, and the rubbing treatment can be utilized at a low cost and at a high yield.

Further, the rubbing cloth of the present invention in which a conductive composite fiber is blended in a part of the texture structure can be used to remove static electricity generated by repeated rubbing, contact, and peeling between the alignment film and the rubbing cloth by the corona discharge treatment. Further, the damage of the circuit provided in the alignment film can be reduced, and the friction treatment of the adsorption phenomenon of dust due to friction can be reduced.

1. . . Multilayer laminated composite fiber

10. . . Rubbing cloth

twenty one. . . Raised layer

twenty two. . . Base

twenty three. . . Conductive composite fiber

30,40. . . Conductive composite fiber

31. . . Conductive layer

32. . . Shielding polymer layer

33. . . Protective polymer layer

41. . . Protective polymer layer

A. . . Fibrous forming polymer A

B. . . Fiber-forming polymer B which is incompatible with polyester A

[Fig. 1] is a cross-sectional view showing an example of a multi-layer laminated type composite fiber used as a flat ultrafine fiber forming component of the raised yarn of the rubbing cloth of the present invention.

Fig. 2 is a typical cross-sectional view showing a configuration example of the rubbing cloth of the present invention.

[Fig. 3] is a typical cross-sectional view showing an example of the conductive composite fiber used in the present invention.

Fig. 4 is a typical cross-sectional view showing a conductive composite fiber used in a comparative example of the present invention.

10. . . Rubbing cloth

twenty one. . . Raised layer

twenty two. . . Base

twenty three. . . Conductive composite fiber

Claims (3)

A rubbing cloth for rubbing an alignment film of a liquid crystal display device, wherein the rubbing cloth is composed of a ground base and a raised yarn, and the warp and weft of the base are At least a part of the heat-fusible composite fiber is used, and the raised yarn is a flat ultrafine fiber of 1.1 dtex or less obtained by dividing a multi-layer laminated type composite fiber, that is, a flat ratio (longitudinal to short diameter ratio) of 4 or more is extremely fine. Made up of fibers. The friction cloth of claim 1, wherein the base layer comprises a conductive composite fiber, the conductive layer of the conductive composite fiber is not exposed from the surface of the fiber, and the conductive property is 10 ⁵ to 10 ⁹ per filament. Ω/cm. The rubbing cloth of the second aspect of the patent application is a conductive composite fiber obtained by applying a barrier polymer layer to the outer periphery of the conductive layer of the conductive composite fiber.