JP4426366B2 - Rubbing cloth material for LCD panel manufacturing - Google Patents

Description

  The present invention relates to a rubbing cloth material for manufacturing a liquid crystal panel. In the liquid crystal panel manufacturing process, alignment treatment is performed using a rubbing roller in which a rubbing cloth material having a raised pile is attached to the outer peripheral surface of a metal roller with a double-sided adhesive tape. This alignment treatment is a one-way operation on the surface of the alignment film by uniformly rubbing the surface of the alignment film formed on the surfaces of the two substrates constituting the liquid crystal panel with the pile on the surface of the rubbing roller that rotates at high speed. It is the process which provides the molecular orientation of. Such a process is called an alignment process or a rubbing process. The present invention relates to a rubbing cloth material used in a rubbing process essential for manufacturing a liquid crystal panel.

  The rubbing process will be described with reference to FIG. Rubbing is a process in which a cloth material 2 with a pile standing on its surface is attached to the outer peripheral surface of a metal roller 1 with a double-sided adhesive tape, and is rotated on the surface of the substrate 5 constituting the liquid crystal pile while rotating at high speed. This is an operation of rubbing the surface of the alignment film at a high speed with a pile of the cloth material 2. This rubbing step is intended to impart molecular orientation in one direction to the surface of the alignment film. The symbol d in FIG. 5 indicates the indentation depth of the fabric material 2 with respect to the surface of the base material 5, which is commonly referred to as the cut amount. The magnitude of the cut amount d has the strongest influence on the alignment performance.

  A liquid crystal display element used in a transmissive liquid crystal display panel is a TFT substrate on which a driving element (TFT) made of a thin film transistor is formed and a CF substrate on which a color filter (CF) is formed with a small gap therebetween. The liquid crystal is sealed in the gap. An ITO electrode patterned as a pixel electrode is disposed on the surface of the TFT substrate, and an alignment film is formed so as to cover the surface of the ITO electrode.

  The TFT substrate and the CF substrate are arranged so that the alignment films face each other, and the alignment films of both substrates are in contact with the sealed liquid crystal. The alignment film on the TFT substrate surface and the CF substrate surface is subjected to an alignment process using a rubbing cloth material to align liquid crystal molecules. The rubbing cloth material is usually attached to the outer peripheral surface of a roller made of a material such as aluminum or stainless steel via a double-sided adhesive tape. The alignment film surface is rubbed with the rubbing cloth material by bringing the rubbing cloth material on the outer peripheral surface into contact with the alignment film surface while rotating the roller. When such rubbing treatment is performed on the alignment film, ultrafine grooves are formed on the surface of the alignment film itself, or uniaxial alignment is imparted to polyimide molecules that are polymers forming the alignment film. When the liquid crystal comes into contact with the alignment film subjected to the rubbing treatment, liquid crystal molecules are aligned in the direction rubbed by the rubbing cloth material, and uniform switching characteristics of the liquid crystal by the electric field are realized. The performance of liquid crystal alignment by rubbing treatment affects the uniformity of display characteristics that are most important for a liquid crystal panel.

  As the rubbing cloth material, a velvet fabric composed of a ground cloth and a pile woven in a raised state on the ground cloth is generally used. As materials for piles, those using long fibers (filaments) such as rayon and nylon and those using short fibers such as cotton are known. As a velvet structure used for the rubbing cloth material, a fast pile velvet fabric as shown in FIG. 6 using cupra rayon for the warp and weft of the fabric structure and viscose rayon for the pile (see Patent Document 1) ) Is common. Further, a V-shaped pile (cut pile) velvet fabric (see Patent Document 2) using cotton as a pile is also used. However, it is not limited to these combinations. For example, even when cotton is used for the pile, it is possible to weave with a fast pile structure, and any structure can be applied to a velvet fabric of thermoplastic synthetic fibers such as acetate fibers and polyester fibers.

  In a rubbing cloth material using this kind of velvet fabric, it is known that the leading edge of the pile is inclined to the direction following the pile root, which is an effective means of avoiding uneven orientation due to uneven rubbing. (See Patent Document 3). However, in the velvet structure according to the above prior art, the pile cannot be inclined at an arbitrary angle only by the action of the fiber weaving structure.

  As a conventional method for inclining a pile of a rubbing cloth material, for example, a rubbing cloth material of a velvet fabric using rayon for the pile is described in detail in Patent Document 3. Specifically, a velvet cloth woven by a general method is immersed in a glyoxal-based cellulose-reactive resin, combed with a brush in a curing machine, and then the resin is heated and cured to maintain the pile slope. A method is described. This method is called resin impregnation. In addition, since a cellulose-reactive resin is used, it is effective for regenerated cellulose fibers such as cotton other than rayon, polynosic fibers, lyocell, and fibers (hereinafter referred to as cellulosic fibers) composed of cellulose derivatives. However, there are some problems in providing a slope of a pile by such resin processing, and this is a problem for future high definition and high yield of liquid crystal panels.

Moreover, in the rubbing cloth material using a cotton pile, there is no effective means for uniformly tilting the pile without using a method equivalent to the resin impregnation in the rayon described above.
Japanese Patent No. 3209328 Registered Utility Model No. 3045464 Registered Utility Model No. 3032820 H. Tabira and T. Inoue etal. "Precision Rubbing Supported by Fine Process Analysis" Journal of the SID Vol.10, No.4, 329-337 (2002)

  In the conventional resin processing method described above, there is a high possibility that the processing shape and the cloth characteristics vary for each processing lot. For this reason, in the manufacturing process of the liquid crystal display panel, the velvet fabric received is rubbed preliminarily to test the orientation quality, and after confirming whether the lot of velvet fabric can withstand use. Used in the manufacturing process. However, even if such an arrival check is executed, the variation in the cloth quality itself is not improved, and unexpected rubbing defects are constantly occurring.

  In addition, the conventional rayon velvet also has a problem related to the resin itself used for processing. That is, since the rubbing cloth material (velvet) is impregnated with the cellulose reaction type resin, the resin adheres to the surface of each single fiber constituting the pile of the velvet. This resin tends to be relatively hard and brittle. Therefore, during rubbing, the resin is worn and dropped to become foreign matter, which adheres to the alignment film surface and may cause defects such as display unevenness (see Non-Patent Document 1). Further, the foreign matter caught in the pile may cause scratches on the surface of the alignment film.

  Further, the cellulose-reactive resin is an aqueous emulsion, and a rubbing cloth material using cupra as a ground yarn is very easily deformed in a state containing moisture. For this reason, the weft of the rubbing cloth material is deformed into a bow shape (commonly referred to as “boeing”), so that a so-called cloth bend is easily generated in which the weft does not intersect the warp at a right angle.

  In view of the above, there is a need for a method for accurately giving a stable slope to a pile without impregnating with resin.

  As a method for forcibly inclining the pile without impregnating the resin, for example, the pile is made of thermoplastic synthetic fiber, and the pile on the surface is heated by contact heating from the back side of the velvet fabric with a heating cylinder. A method of combing in a direction with a brush and then cooling and fixing is known. However, this method is susceptible to the temperature and humidity of the outside air, and it is difficult to stably mass-produce the pile with a constant inclination angle. Further, even if this method is applied to a velvet fabric in which the pile is a cellulosic fiber such as cotton, it is difficult to impart a stable tilt angle to the pile because the cellulosic fiber is not thermoplastic.

  As described above, the conventional pile tilting method is limited in the applicable pile material, and even if it can be applied, the solution of other problems inherent in the method itself is not perfect.

Therefore, the object of the present invention is that there is no problem such as the occurrence of defects in resin impregnation, there is no limitation on the pile material, and a stable slope is imparted to the pile of the velvet structure, which makes it very good in the production of liquid crystal panels. The object is to provide a rubbing cloth that can be used.

  In order to obtain a rubbing cloth material in which a pile is erected while maintaining a stable inclination, the present inventor can change the warp feed amount for each predetermined number in a velvet fabric base fabric structure. I found it effective. Specifically, if the amount of warp sent out during weaving is increased / decreased by a predetermined number, the upper and lower steps of the weft entangled with this will be woven around the weft. The present invention has been completed by finding that an inclination in the warp direction is imparted to the pile yarn.

  That is, the present invention is a rubbing cloth material for manufacturing a liquid crystal panel of a velvet fabric having a ground fabric structure composed of warps and wefts, and a pile yarn woven in the warp direction of the ground fabric structure. A rubbing cloth material for manufacturing a liquid crystal panel, characterized in that it is constituted by a ground fabric structure structure in which warp yarns having different weaving yarn lengths are combined.

  In the present invention, the pile is tilted by devising the fabric structure itself without relying on resin processing, heat brushing, or the like. Therefore, there is no restriction on the pile material, and there is no occurrence of defects and other problems in the conventional resin impregnation. In the present invention, it is possible to give the pile an inclination in the direction of the warp with respect to the normal of the surface of the fabric by changing the weaving yarn length of the warp of the fabric. And if such a rubbing cloth material whose slope of pile is stably controlled is used for the manufacture of liquid crystal panels, the alignment state of the liquid crystal panels can be made extremely uniform, and a significant improvement in image quality as a display device is achieved. it can.

  FIG. 1 is a schematic view of a velvet structure according to an embodiment of the present invention. FIGS. 2 and 3 are velvet fabrics woven with the structure of FIG. 1 cut at different positions in a direction parallel to the warp. FIG.

  As shown to Fig.1 (a), the velvet structure | tissue is formed from the pile 12 woven in the state which stood up in the fabric structure 11 and the fabric structure 11. As shown in FIG. In this embodiment, the fabric structure 11 is woven by the warps 14a, 14b, 14b ′ and the weft 13 supplied from the double beam. At the time of velvet weaving, the warp yarn 14a is fed from one beam of the loom, and the feed amount is small. Therefore, a high tension is applied to the warp 14a during the beating. On the other hand, the warp yarn 14b and the warp yarn 14b ′ are fed from another beam of the loom, the feed amount is large, and the tension at the time of beating is low. Wefts a, c, d, and f are located on the side (front side) where the pile 12 stands from the warp yarn 14a, and the wefts b and ho are located on the back side from the warp yarn 14a. The warp yarn 14b and the warp yarn 14b 'are woven with the weft yarn 13 alternately in front and back.

  Note that the present invention is not limited to the velvet structure shown in FIG. For example, among the three warps 14a shown in FIG. 1A, one without the middle warp 14a can be used. Furthermore, it is possible to incline the pile 12 in the warp direction by devising the structure.

  A state in which the pile 12 is inclined by the velvet fabric (ground fabric structure 11) woven in this way will be described with reference to FIGS. 1 (a) and 1 (b). In the present embodiment, when the warp feed amount is increased / decreased for each predetermined number, upper and lower steps are generated in the wefts entangled therewith. Specifically, it is as follows.

The velvet weaving order will be described. First, as a result of the weaving machine up-and-down movement, the warps 14a, 14b, 14b 'are divided into upper and lower openings, and the weft I is driven into the open position. It is pushed into. Next, the weft yarn is driven into the opening by changing the vertical relation of the previous warp by the reverse movement of the kite, and the weft yarn is pushed between the warps by the beating operation. At this time, in the cross section of FIG. 1B, the weft thread B is located on the lower right side of the weft thread A in relation to the warp thread 14b. Furthermore, the weft yarn C that is driven after the next scissor movement is also pressed between the warps by the scissoring motion. At this time, since the feed amount of the warp yarn 14b ′ that holds the weft yarn C is large, the weft yarn C tends to be pushed up above the weft yarn B as shown in FIG. In some cases, as shown in FIG. 4B, the weft yarn C is pushed up onto the weft yarn A, and the weft yarns A to C overlap in a row. In this state, the pile 12 is pressed diagonally by the wefts A to C, and given a predetermined angle in the direction along the warp direction as shown. The same applies to the weft yarns D to F.

  FIG. 2 is a trace of a photomicrograph of a cross section of the velvet structure of the present invention woven in the state of FIG. 4B (a cross section where the warp yarn 14a with a small amount of feed is visible). This figure shows a state in which the wefts run over each other, and the pile is confirmed to be inclined by being pressed by these wefts. The inclination angle of the pile can be adjusted by, for example, a large / small warp feed amount, a weft density, and a weft thickness. This inclination is physically given by the structure of the woven fabric. If the woven fabric standard is constant, an inclination of a certain angle is always given, and even if subjected to heat treatment, washing, etc. after weaving, it will not return. Absent.

  FIG. 3 is a cross section at another position parallel to FIG. 2 (a cross section where the warp yarns 14b and 14b ′ having a large amount of feed are visible), and the warp yarns 14b and 14b ′ appear to have large undulations in the vertical direction. Observed.

  The material of the pile used in the present invention is not limited to natural fibers such as cotton, and any synthetic fiber or semi-synthetic fiber such as triacetate, nylon, vinylon, rayon, or polyester can be used.

  In the present invention, the pile of the rubbing cloth material is inclined in the warp direction with respect to the normal line of the surface of the cloth material. The inclination angle of the pile is preferably 5 degrees or more and 45 degrees or less, and more preferably 10 degrees or more and 45 degrees or less with respect to the normal of the surface of the cloth material.

  In the present invention, in order to configure a base fabric structure in which warp yarns having different weaving yarn lengths are combined, a predetermined number of warp yarns constituting the base fabric are used as in the embodiment described above. There is a method of sending and weaving warp yarns with a large / small feed amount every other number.

  As a means for adding / decreasing the warp feed amount at the time of weaving for each predetermined number, for example, supplying warp with a double beam, one beam increases the warp feed amount, and another The warp feed amount of the beam may be reduced. As a result, warp yarns with a small feed amount and warp yarns with a large feed amount can be arranged every predetermined number. The feed amount may be adjusted by, for example, so-called positive feed, in which a warp beam is rotated by a gear operation to feed a warp yarn in accordance with beating at the time of weaving. Further, it is also possible to perform so-called depolarization feeding, in which the warp beam is subjected to friction to control the rotation of the warp beam.

  In addition, using a high-shrinkage synthetic fiber as a warp with a small amount of feed, and shrinking the high-shrinkage synthetic fiber after weaving, a fabric structure that combines warp yarns with different warp weaving yarn lengths is combined. It can also be configured. Although it does not specifically limit as a highly shrinkable synthetic fiber, It is preferable to use the polyester fiber whose boiling water shrinkage rate is 8% or more.

  Hereinafter, the present invention will be described in more detail with reference to examples.

<Examples 1-4>
The rubbing cloth material of the present invention was produced under the weaving conditions shown in Table 1 as follows, and the pile inclination angle (angle with respect to the vertical direction of the fabric structure) was measured.

  In Examples 1 to 4, a polyester dwarf of 110 dtex was used as the ground warp, the ground warp density was 35 pcs / cm, and the yarn tension of the warp with the smaller feed amount was unified to 104 to 110 g, and the feed amount was Weaving was performed by changing the feed amount of the larger warp and the thickness and density of the weft yarn as shown in Table 1. As the pile yarn, a cotton No. 60 comber double yarn was used. After weaving, it was set at 150 ° C. and finished by ordinary processing steps such as desizing scouring, drying, and back resin processing. The pile length after finishing velvet cloth was unified to 2.4 mm.

About the rubbing cloth material of Examples 1-4 produced on the above weaving conditions, each pile inclination angle was measured. The measurement results are shown in Table 1. From these results, it was confirmed that different pile inclination angles can be obtained only by devising the weaving conditions. As for the inclination angle, the inclination angle with respect to the warp direction was measured with respect to the normal of the surface of the fabric. Specifically, the main factors that determine the angle of inclination are the amount of ground warp delivered and the resulting tension difference between the ground warp, the thickness of the weft, and the weft density (however, the upper limit of the weft density depends on the weft thickness) Is). By controlling these, it was confirmed that a fabric having the same pile inclination angle was always repeated and weaved stably.

  Furthermore, the expression state of the rubbing longitudinal muscle was evaluated by the method shown in FIG. That is, each of the rubbing cloth materials of Examples 1 to 4 was wound around a stainless steel rubbing roll 1 having a diameter of 50 mm using a double-sided tape, and the polyimide precursor solution was printed and applied to a 10 cm square glass substrate. The glass substrate 5 to which the polyimide alignment film prepared by heating was attached was fixed to the moving stage 6, the cutting amount d was set to 0.5 mm, and the moving stage 6 was moved in the direction of the arrow at a speed of 30 mm per second and rubbed. . The number of rotations of the rubbing roll 1 was 1500 rpm. As a result, a uniform alignment film with few vertical stripes was obtained for all rubbing cloth materials.

<Examples 5-7>
As described below, a rubbing cloth material of the present invention was prepared using triacetate or polyester fiber as a pile yarn, or using a high shrinkage yarn as a ground warp with a small amount of feed, and the pile inclination angle was measured.

  In Example 5, when a 56 dtex polyester twin yarn was used as the ground warp and the warp length of the warp with the smaller feed amount was 100, weaving was performed with the warp yarn length of 280 being the greater feed amount. The tension at that time was 104-110 g for the former and 65-70 g for the latter. As the pile yarn, 84 dtex double yarn of triacetate was used. After weaving, the cloth was set at 150 ° C. and finished by usual processing steps such as desizing refining, drying, and back resin processing to obtain a rubbing cloth material (velvet cloth material).

  In Example 6, a 56 dtex high-shrinkage polyester twin yarn (boiling water shrinkage 35%, JISL-1013) was used as the ground warp with the smaller delivery amount, and the shrinkage as the ground warp with the larger delivery amount was normal. Of 56 dtex polyester twine. The feed amount of the yarn was set to 100 for the former and 120 for the latter. The tension during weaving was 100 g to 110 g in both cases, and they were almost the same. As the pile yarn, 84 dtex double yarn of triacetate was used. After weaving, dry heat treatment was performed at 150 ° C. for 5 minutes. In this heat treatment, 12% overfeed in the length direction of the dough and 2% in the width direction were started, and then finished in a normal processing step to obtain a rubbing cloth material. In Example 6, the high shrinkage polyester twine was heat-treated and shrunk to change the yarn length ratio and to give the pile an inclination angle.

  In Example 7, a rubbing cloth material was prepared according to the same process as Example 5 except that 84 dtex double yarn of polyester was used for the pile.

About the rubbing cloth material of Examples 5-7 produced as mentioned above, each pile inclination angle was measured. The measurement results are shown in Table 1. From these results, it was confirmed that the pile material can give a stable inclination regardless of natural fiber, synthetic fiber, or semi-synthetic fiber. Moreover, in Example 6, it was also confirmed that the same effect as that obtained when the amount of feed was positively changed by shrinking with a fabric using high shrinkage fibers was obtained.

(A) is a velvet structure schematic diagram concerning the embodiment of the present invention, and (b) is the sectional view. It is the figure which traced the microscope picture of the cross section at the time of cut | disconnecting the velvet fabric woven with the structure | tissue of FIG. 1 in the direction parallel to a warp. FIG. 3 is a diagram obtained by tracing a micrograph of a cross section when the velvet fabric woven with the structure of FIG. 1 is cut at a position different from the cross section of FIG. 2 in a direction parallel to the warp. It is a figure for demonstrating the principle which a pile inclines in the structure | tissue of FIG. It is a figure which shows the state (rubbing condition) which the rubbing cloth material affixed on the roller contacted the board | substrate. It is an organization chart of the conventional fast pile velvet fabric. It is an organization chart of the velvet fabric of the V-shaped pile which uses cotton for the conventional pile.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal roller 2 Cloth material 5 Board | substrate 11 Base fabric structure 12 Pile 13 Weft 14a, 14b, 14b 'Warp

Claims (7)

A rubbing cloth material for producing a liquid crystal panel of a velvet woven fabric having a ground fabric composed of warps and wefts, and a pile yarn woven in the warp direction of the fabric structure,
A rubbing cloth material for manufacturing a liquid crystal panel, characterized in that it is composed of a ground fabric structure structure in which warps having different weaving yarn lengths are combined.   The rubbing for manufacturing a liquid crystal panel according to claim 1, wherein the pile yarn is inclined in the direction of the warp with respect to the normal of the surface of the fabric by changing the weaving yarn length of the warp of the fabric. Cloth material.   The pile yarn is inclined in the warp direction with respect to the normal of the surface of the fabric, and the inclination angle of the pile yarn with respect to the normal is not less than 5 degrees and not more than 45 degrees. The rubbing cloth material for liquid crystal panel manufacture as described.   The rubbing cloth for manufacturing a liquid crystal panel according to any one of claims 1 to 3, wherein a warp is sent out by a feeding amount larger than a predetermined number of the plurality of warps constituting the base cloth and woven. Wood.   5. The liquid crystal panel manufacturing method according to claim 4, wherein a plurality of warps constituting the base fabric are supplied by a double beam, and warps with a small amount of feed and warps with a large amount of feed are arranged at a predetermined number. Rubbing cloth material.   6. The rubbing cloth material for producing a liquid crystal panel according to claim 5, wherein the warp with a small amount of feed is a highly shrinkable synthetic fiber, and after weaving, the highly shrinkable synthetic fiber is shrunk.   The rubbing cloth material for producing a liquid crystal panel according to claim 6, wherein the highly shrinkable synthetic fiber is a polyester fiber having a boiling water shrinkage of 8% or more.

Images