TWI266130B - Rubbing cloth for liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

Disclosed is a rubbing cloth for a liquid crystal display device capable of forming finely aligned grooves in the rubbing process of a liquid crystal display device and that is capable of solving the problems of scratch, non-uniform rubbing, etc., and a method of manufacturing the same. The rubbing cloth of the present invention comprises a textile of warp and weft and a pile yarn aligned along the warp or weft of the textile with an inclination. 10 to 50% of all acetyl groups of the acetate fiber of the pile yarn are substituted by hydroxy groups.

Description

1266130 IX. Description of the Invention: [Technical Field] The present invention relates to a rubbing cloth for a liquid crystal display, and a precise alignment groove for aligning liquid crystal on a liquid crystal display glass substrate can be formed on the liquid crystal display, so that Can solve problems such as scratches and uneven friction. Additionally, the invention is also related to a method of making the friction cloth. [Prior Art] In a general LCD process, a substrate on which an alignment film has been formed is subjected to a rubbing process to obtain uniform liquid crystal molecules. The rubbing process is performed by winding a rubbing cloth made of tantalum or nylon onto a drum, and contacting the drum with an alignment film, so that the alignment film is rubbed to form a plurality of alignment grooves. Thereby providing some degree of unidirectional alignment and pretilt angles within a certain range. The alignment film is formed by applying an isotropic alignment film solution containing polyamic acid, soluble polyiimide or the like to a substrate at a temperature of about 60 to 80 ° C. The pre-curing process is carried out by performing a main curing process at a temperature of about 180 to 200 T. The friction means for forming the alignment groove includes a friction roller for winding the friction cloth, and a stage on which the substrate is placed. The stage is provided with a plurality of vacuum holes for fixing the substrate, and a plurality of lifting pins for removing the substrate. When the substrate is loaded onto the stage, the friction roller rotates while moving to contact the top of the substrate. As a result, an alignment groove is formed on the alignment film of the substrate because of the friction of the rubbing roller. If the friction is not uniform, the distribution of liquid crystal molecules will become uneven. 1266130 Even if the optical characteristics may be deviated or lining due to scratches on the surface of the alignment film. The success of the #friction process is determined by the friction time, the friction depth, the number of revolutions, the radius of the drum, and the moving speed of the stage. These 5 process conditions are set by the LCD manufacturer and cannot be easily changed. Therefore, an important factor that can be changed in the rubbing process is the length strength thickness, density, and the like of the rubbing fluff. However, since the woven wool yarn of the conventional rubbing cloth is mostly made of tantalum, the strength is so high that if the frictional strength is uneven, it is liable to cause scratches. In addition, since the thickness of the twisted yarn is changed by 1 ,, the improvement of the pile density is also limited, so that it is difficult to form a precisely aligned groove. Furthermore, because Zhai Rong is unstable when it comes into contact with water, the process becomes complicated and costly. Cellulose acetate (hereinafter referred to as "acetic acid") fiber is also widely used for fluff yarns. However, since 2.5 hydroxyl groups per cellulose molecule are taken up by the ethyl group, the moisture regain is low, so that problems such as static electricity and low fiber rigidity may occur. Therefore, it is not suitable for use in a rubbing cloth used for a liquid crystal display. SUMMARY OF THE INVENTION An aspect of the present invention is to provide a friction lining for a liquid crystal display and a method of manufacturing the same. Compared with the conventional crucible, the rubbing cloth has excellent directness, expansion and recovery characteristics, and can form a uniform and precisely aligned groove, and solves the problem of using modified cellulose acetate as a rubbing cloth. Problems such as scratches and uneven friction. Another aspect of the present invention is to provide a 1266130 liquid crystal display manufactured using the rubbing cloth. The present invention provides a rubbing cloth for a liquid crystal display comprising a fabric of warp and weft yarns and a pile yarn yam having an oblique angle direction along the warp or weft direction, the napkin yarn It is a type of modified cellulose acetate long fiber (m〇dified cdlul〇se-like filament fiber), and 10 to 50% of all ethyl sulfonate groups in the modified cellulose acetate long fiber are replaced by hydroxyl groups. The invention also provides a method for manufacturing a rubbing cloth for a liquid crystal display, the method comprising the following steps: 〇a) weaving a cellulose acetate filament between two kinds of fabrics, thereby producing a pile yarn; b) cutting the fluff between the fabrics; c) modifying the fluff yarns into a basic shape to saponify 10 to 50% of all the ethyl acetate groups of the cellulose fibers into hydroxyl groups; 5 d) for alkaline modification The pile yarn is subjected to napping, brushing, sanding (san (jing) and resin treatment and pr〇cessing) so as to have an oblique angle direction toward the warp or weft direction of the fabric; e) Coating or laminating the fabric to secure the aligned fluff yarns. 〇 The present invention further includes a liquid crystal display fabricated using the rubbing cloth. [Embodiment] The present invention will be described in detail later. The acetic acid fiber is subjected to deacetylation using an alkali or an acid (hereinafter referred to as "Saponification of -8-1266130"). In one test, the cellulose acetate is gradually changed from the outer layer of the fiber to the inner layer. In this way, the fiber ratio has a rayon characteristic and the inner layer has an acetate characteristic layer having a snail 5 10 15 20 The Applicant has found that, if a fluff yarn with a cloth is used to woven a certain amount of acetate 曰, the friction of the device A method of forming a precisely aligned groove during the rubbing process and a method of solving a π-like cloth such as scratching, unevenness, etc. is to weave a plurality of cellulose acetate filaments to the two fabrics of warp and weft. As the woven wool V-line, the surface of the cellulose acetate filament is modified by the test, and the warp or weft yarn is inclined and parallel-aligned, so as to achieve a uniform distribution effect. Preferably, the friction fabric of the present invention forms a precisely aligned groove along the direction of increasing the density of the pile. Therefore, for the fabric (base fabric), it is preferable to use a viscous filature filament or a cupraammonium filament in the range of 50 to 2 den denier. Further, for the fluff yarn, cellulose acetate long fibers ranging from 5 to 24 angstroms are preferably used. The cellulose acetate long fiber preferably has a degree of substitution of from 2 Å to 2,75. The velvet yarn has a filament density of at least 24 Å per square centimeter. The pile yarn woven between the two fabrics should preferably be cut so as to change the length of the pile to 1.4 to 2.1 mm. After cutting off the thief hair, it is recommended to use 5 to 20 wt% per 100 wt% of cellulose acetate -9- 1266130. If the content of the base is less than $ wt%, the outer layer of the fiber does not have a glory property, so that it is difficult to form an alignment groove suitable for a liquid crystal display due to factors such as static electricity and low fiber strength. On the other hand, if it exceeds 20% by weight, even if the inner layer has a bismuth characteristic, so that static electricity, low fiber strength, and the like may occur, the stability in water is deteriorated, making it difficult to obtain a uniform pile. In the case of a base, it is preferred to use a separate aqueous test solution, or a reaction solution obtained by mixing an aqueous test solution with a reaction aid. After the base is modified, the cellulose acetate filament fiber has a degree of saponification of from 1 Torr to 5 % by weight. That is, the cellulose acetate having a degree of substitution in the range of 2.0 to 2.75 is modified to have 1 to 50%, but preferably 20 to 40%, of all the ethyl acetate groups of the acetic acid saponified by the hydroxyl group. As a result, the acetate fiber has a degree of substitution ranging from 1.27 to 1.91. If the degree of saponification of the cellulose acetate is less than 10%, the outer layer of the fiber does not have a bismuth characteristic, so that it is difficult to form an alignment groove of the liquid crystal display due to factors such as electric power and low fiber strength. On the other hand, if it exceeds 50%, even if the inner layer has a bismuth characteristic, so that problems such as static electricity and low fiber strength do not occur, the stability in water is lowered, making it difficult to obtain a uniform woven wool. For the test compound, a metal oxide such as sodium hydroxide, an alkaline earth metal hydroxide such as calcium hydroxide, an alkali metal carbonate such as sodium carbonate, or the like can be used. The aqueous alkaline solution may comprise a reaction auxiliary which is compatible with the base and which controls the reaction rate. The content of the reaction assistant is preferably from 0 001 to 2 . Examples of reaction auxiliaries sold in the market, respectively, belong to squamous compound > -10- 1266130

Neorate NCB (available from Hankook Fine Chemicals), KF Neorate NA_40 (available from Hankook Fine Chemicals) and Snogen PDS (available from Dae Young Chemical). The alkali-modified fluff yarn is subjected to flocking, brushing, sanding, and resin treatment, so that the fabric is angularly aligned along the warp or weft direction. In order to orient the pile yarn along the warp or weft direction of the fabric, the saponified pile fabric is transferred along the warp direction of the fabric on a tenter equipped with rotating brushes of various shapes and types. Brushing is carried out. The brushes are rotated in the warp or weft direction depending on the size and purpose of the 10 rubbing cloth used. The pile has a slope of 5 to 40 degrees with a vertical reference line on the fabric. If the angle of the fluff is less than 5 degrees, the alignment film may be scratched. On the other hand, if it exceeds 4 degrees, the alignment groove will not be formed correctly. During the brushing process, a shrink-proofing agent, a bismuth-based elastomer, or the like may be impregnated into the pile fabric to improve the mechanical stability of the pile yarn. In this treatment, the nature and concentration of the various agents added may vary depending on the purpose. These agents are not particularly limited as long as they are capable of improving the mechanical stability of the pile yarn. A coating agent is used to coat or laminate the inner fabric of the pile fabric to prevent the pile yarn from coming off the fabric or adhering to the alignment film during the alignment process. 20 In the case of a coating agent, at least one resin selected from the group consisting of polyurethane, polyvinyl acetate, polyacryl, polyamine can be used. (p〇lyamide), polyimide, polyester (p〇lyester), and polyurea (polyurea). If the coating on the inner fabric is too thick, the rubbing cloth will not stick to the -11- 1266130 to the friction roller, so that the friction becomes uneven. Conversely, if the coating is too thin, the fluff can be released from the fabric and allowed to adhere to the alignment film during the alignment process, resulting in insufficient friction. Therefore, the coating amount is preferably from 10 to 100 g/cm2. As described in uranium, the friction cloth of the present invention allows a cellulose acetate yarn to be easily modified, that is, it can form a precise alignment groove during the friction processing of the liquid crystal display, and solve the problem of unevenness of scratches and friction. . Accordingly, the present invention can provide a liquid crystal display having significantly improved optical characteristics. The invention will be described in detail by way of a few examples. However, the following examples are merely for understanding the invention and are not intended to limit the invention. 10 Example [Example 1] 120%/70f of cuprammonium filament (Japan's eight actor company for sale 15 20) and 75d/50f of cuprammonium filament (Japan _ company supply 隹) The warp and weft yarns are woven into a fabric having a warp density of 6 and a weft density of U7/忖. Then, as a kind of 12Qd/33f cellulose acetate (degree of substitution -2·55 'cool acid substitution degree = 56.5%) filament (sold by Korea SK company) as fluff =, weaving with ordinary fluff The machine weaves it into a fabric of fluff density and w shape. Cut the fluff between the two base fabrics:: Γ Γ 醋酸 acetate, fabric. The obtained V material was cleaned according to a general method and allowed to dry. Then, add the caustic soda solution of each vinegar ί Γ Wt% to the weight loss tank. The acetic acid fluff fabric was dipped in the solution under the armpit and heated at a rate of 2. After 3 G minutes of treatment at a temperature of 98 ° C, the temperature was cooled to 3 〇 〇 c at a rate of -12 to 1266130 at 2 T/min, and the solution was discarded. The fabric was then washed at room temperature to remove residual alkali. Finally, the fabric is taken out and allowed to dry. This saponification process is used to obtain a thief fabric having a starting weight of 5.2% (saponification degree = 125%) based on the cellulose acetate. Further, the obtained fabric was immersed in a solution of Snotex SF_8 〇〇 3% 〇ws, that is, a ruthenium-based elastomer prepared by Dae Young Chemical Co., Ltd. Then, on a tenter equipped with a brush, it is piled ten times in the direction of the warp and the weft so that the pile is inclined 26 along the warp direction. . The aligned fluff is then fixed with a polyvinyl acetate coating. The coating agent is impregnated into the inner base fabric and fixed by heat at a temperature of 140 to 16 ° C. The thus obtained pile fabric was cut, and the total thickness of the pile became 1·8 mm 〇 [Example 2] 1 g/L of Sn〇gen PDS produced by Dae Young Chemical Co., Ltd. Adding to 20 wt% of caustic copper solution, a reaction solution was obtained, and then the fabric of Example 5 was saponified with the reaction solution to obtain a pile fabric having a weight loss ratio of 198%, followed by 'subsequent entry A Snotex GR 6% 〇ws solution, namely Dae

In a glyoxal-based anti-shrinkage agent manufactured by Yo^ng Chemical Co., the process of brushing, coating, heat setting, and cutting is carried out as in Example 1. [Example 3] 120%/70f copper ammonium lanthanum filament (sold by Japan Asahi Co., Ltd.) and 75d/50f copper ammonium lanthanum filament (sold by Japan Asahi Co., Ltd.) are used as the yarn and weft yarn, respectively. Woven into a fabric with a warp density of 6 〇 / 吋 and a latitude of -13 - 1266130 (four). Then, with a kind of coffee 0f of cellulose octane = 2.55 'acetate substitution degree = 56.5%), the filament (Korea Jung == wool yarn) was woven into a velvet by a general pile weaving machine; it was 40,000/cm and W-shaped fabric. Like van, but m for cutting and pre-treatment. Then, with each ioow ::: ·, /〇ows solution, that is Dae Youns into = 丨 = a company produced by Shi Xiji In the elastic agent, as in the case of the example 1, the process of brushing, coating, heat setting, and cutting is carried out.

10 [Example 4J PDSY 叭-Y〇Ung ChemiCal company's Sn〇gen = 'Immediately - fresh lysine reaction _ added to 2G w 3 reaction complex, then called reaction solution (four) as Fan ^ ". 7 kinds of weight loss ratios are obtained by 195% _ wool woven, which will be sub-into saki x GR 6% 〇 ws solution (10) same = 丨? Tieal company produced - the second two peak defense, and then For example, the door is used for brushing, coating, heat setting, and cutting. [Comparative Example 1] = Do not use 70% copper ammonium snail filaments (Japan Asahi company for two:: copper coins 嫘萦Filament (曰仏二二Γ woven into a warp density of break and weft density of 98 / 2 =. Then with a kind of test of the mixed silk (German test = two) as a pile yarn] A fabric that is complementary to the sample of Example 1. The fluff fabric obtained is refining -14266130 as in Example i. Then, it is immersed in a Snotex GR 6% ows solution, manufactured by Dae Young Chemical. In a glyoxal-based anti-shrinkage agent, the process of brushing, coating, heat-fixing, and cutting is performed as in Example 1. [Comparative Example 2] 1 woven into one A fabric having a fluff density of 325,000/cm2 and a W shape is obtained. The obtained fluff fabric is refining as in Example 1. Then, it is immersed in a Snotex GR 6〇/〇0WS solution, that is, Dae Y〇ung Chemical Co. The system - the second type of anti-adhesive towel, and then the process of brushing, coating, heat-fixing, and cutting, etc. as in the case of i. 15 For each sample and comparison, the various fabrics are tested as follows. 120d/70f copper ammonium lanthanum filament (sold by Japan Asahi Co., Ltd.) and 75d/50f copper ammonium lanthanum filament (sold by Japan Asahi Co., Ltd.) are used as warp and weft yarns, which are woven into a warp density. It is a fabric of 6〇/吋 and a weft density of 114/吋. It is then treated with a 12〇d/4〇f viscous 嫘萦 filament (sold by Enka, Germany) as a pile yarn, using general pile weaving. Machine

The weight changes before and after. Weight loss ratio [Equation 1] Weight loss ratio = weight Weight loss ratio =

The sample was made into a 50 mm long sample with the fibers J used to make the fluff. Prepared. -15- 1266130 ◎ Friction voltage of fiber··In KS Κ 0555, 2〇%, Qing 5 (2〇°c, add 1 hour, please press the pressure, and then evaluate the velvet yarn to apply the list! Samples i through 4 are added, Μ, 减, and weight loss ratio. The ones listed in Table 2 below are:

A comparison of the physical properties of the St case. The following table 3 is the ones mentioned above: 切割, the cutting strength, friction voltage, and elastic recovery of the friction cloth of the comparative example, and the 瑕疵* rate of the IPS type liquid crystal display process using the rubbing cloth In total number of substrates). Table 1 •-—Test (Wt0/o) Reaction aid (g/1) — 5 - ^~—~--- 20 1 ~l9T^~ ---- 5 - 1----- 20 1 L9j^— 乂~~.__

-16- 1266130

As can be seen from Table 3, Examples i to 4 exhibited extremely excellent cutting strength, friction 5 voltage 'elastic recovery, and low defect rate during liquid crystal display manufacturing as compared with Comparative Examples i and 2. As described above, according to the present invention, a rubbing cloth for a liquid crystal display can be easily produced by modifying a cellulose acetate fluff fabric. The resulting friction cloth can form an alignment groove during the alignment process and solve problems such as scratches and unevenness in friction. The above embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention. All changes and modifications that are not inconsistent with the invention are within the scope of the invention. -17-

Claims (1)

1266130 X. Patent application garden: 1. A friction cloth for liquid crystal display, comprising a warp and weft fabric, and a pile yarn having an oblique angle direction along the warp or weft direction of the fabric; Wherein the fluff yarn is a modified cellulose acetate filament fiber, and 10 to 50% of all 5-ethylidene groups of the fiber are substituted by a trans group. 2. The friction cloth for a liquid crystal display according to claim 1, wherein the pile yarn has a filament density of at least 24,000 每3 per square centimeter, as described in claim 1 of the patent application. In the liquid crystal display, the pile yarn is maintained at an oblique angle of 5 to 40 degrees with a vertical line along the direction of the weft or warp yarn. 4. The rubbing cloth for a liquid crystal display according to claim 1, wherein the interior of the fabric is at least one coating or laminated resin selected from the group consisting of: polyurethane, Polyvinyl acetate, 15 polypropyl 'polyamide' ^ brewed imine 'polyacetate, and polyurea. 5. A method of manufacturing a rubbing cloth for a liquid crystal display, comprising the steps of: a) weaving a cellulose acetate filament between two fabrics to produce a pile fabric; 20 b) cutting two The fluff between the fabrics; c) the fluff yarn fabric is modified with a base so that 10 to 50% of all the ethyl acetate groups of the acetate fiber are saponified into hydroxyl groups; d) the modified fluff yarn is started Velvet, brushing, fine grinding, and resin processing so that the pile yarn has a -18- along the warp or weft direction of the fabric