JP3050166U - Cushion material for liquid crystal cell assembly - Google Patents

Abstract

(57) [PROBLEMS] To provide a cushion material capable of uniformly pressing a substrate without contaminating the substrate in a liquid crystal cell assembling step such as a glass substrate bonding step. SOLUTION: Fluororesin fine particles 12 are formed on a sheet 16 made of an elastomer such as fluororubber or silicone rubber.
Cushioning material 10 having a structure bonded by a latex adhesive 14. The surface to which the fine particles 12 of the fluororesin are adhered becomes an operating surface when applying pressure to the substrate in the liquid crystal cell assembling step.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a cushioning material used in a liquid crystal cell assembling process, and more particularly to a cushioning material used for performing a necessary process while appropriately pressing a substrate such as a substrate bonding process in a liquid crystal cell manufacturing process. .

[0002]

[Prior art]

 In the manufacture of a liquid crystal display, a liquid crystal cell such as a color TFT cell is formed by (1) a step of forming an alignment film on each of two glass substrates on which a TFT element and a color filter are formed, and (2) a rubbing roll. Rubbing the surface of the alignment film in a certain direction, (3) Spraying spacers on the substrates to keep the distance between the two substrates constituting the liquid crystal cell constant, (4) Attach transfer electrodes (5) a step of printing a sealant for bonding the substrates around the substrate, (5) a step of bonding two substrates with the sealant printed face-to-face, and (6) a scribe-break process (7) a step of injecting a liquid crystal material into an empty cell and sealing the injection port, and (8) a step of attaching a polarizing film to the outside of the cell into which the liquid crystal material has been injected. Assembled through the communicating processes.

In such an assembling process, in a process of proceeding while appropriately pressing a substrate, an appropriate cushion is required at the time of pressing, and a rubber cushion material is generally used. In particular, in the substrate bonding process, where two substrates are faced to each other and aligned and bonded, a uniform force is applied to the substrate surface and the scattered spacers in order to keep the distance between the substrates constant throughout the cell. Therefore, a moderate press is required. Such pressurization of the substrate is usually performed via a rubber cushion material provided in a portion for holding the substrate to be bonded in the liquid crystal cell bonding device.

[0004] Recent liquid crystal cells such as color TFT cells are following an ultra-thin direction, and glass substrates having a thickness of 0.7 mm are becoming mainstream. It is important to press uniformly on such a thin glass substrate with a relatively large surface area without bending. Normally, the rubber surface has extremely high frictional resistance, and therefore, when pressure is applied to such a rubber surface, the glass substrate is likely to bend. Therefore, it is necessary to cause slight slippage in the shearing direction during pressurization and absorb bending. In order to meet such a demand, for example, a method of providing a thin film of polyethylene, polyester or the like on the surface of the rubber cushion material when applying pressure to the substrate, and taking a method of buffering the frictional resistance of rubber can be adopted. However, the process of providing such a film at the time of pressurization is a complicated operation, and wrinkles are easily generated in the film. If the film is wrinkled on the rubber cushion material, uniform pressing may not be possible.

Further, it is necessary to assemble the liquid crystal cell in an extremely clean environment. Therefore, it is desirable that the cushion material used when pressing the substrate is also made of a material and a structure that does not generate contaminants.

[0006]

[Problems to be solved by the invention]

 An object of the present invention is to provide an unprecedented cushioning material for assembling a liquid crystal cell having a pressurized surface with a remarkably low coefficient of friction and suitable for uniform pressurization.

A further object of the present invention is to provide a cushioning material for assembling a liquid crystal cell having a structure and a material capable of effectively suppressing the generation of contaminants.

[0008]

[Means for Solving the Problems]

 The inventor of the present invention has applied a fluororesin-based material with a remarkably low coefficient of friction to the surface of a rubber cushion material that comes into contact with a glass substrate during processes such as a substrate bonding process involving pressing and a polarizing film bonding process in the production of liquid crystal cells. It has been found that by coating, the generation of contaminants from rubber can be remarkably prevented, and that the uneven pressurization of the press can be eliminated by the low friction coefficient of the fluororesin-based material.

That is, the cushioning material for assembling a liquid crystal cell according to the present invention is a cushioning material used when pressure is applied to a substrate constituting a liquid crystal cell in a process of assembling the liquid crystal cell, and a fluororesin is formed on a sheet made of an elastomer. The particles have a structure in which the fine particles are bonded by a latex adhesive, and the surface to which the fine particles of the fluororesin are bonded is an operating surface when pressure is applied to the substrate. In such a cushion material, the fluororesin comprises polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and tetrafluoroethylene-perfluoroalkylvinyl ether copolymer. The elastomer is preferably at least one selected from the group, and the elastomer is preferably at least one selected from the group consisting of fluororubber, silicone rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber and butyl rubber.

Further, according to the present invention, a cushion material used when applying pressure to a substrate constituting a liquid crystal cell in a process of assembling the liquid crystal cell, the surface of which is made of an elastomer and has fine irregularities almost uniformly distributed on the surface. It has a structure in which fluororesin microparticles are bonded by a latex adhesive on the attached sheet, and the surface on which the fluororesin microparticles are bonded is an operating surface when applying pressure to the substrate. Cushioning material is provided. In such a cushioning material, the fluororesin is a group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer and tetrafluoroethylene-perfluoroalkylvinyl ether copolymer. It is preferable that at least one selected from the group consisting of fluorine rubber, silicone rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber and butyl rubber is used. .

[0011]

[Embodiment of the invention]

 In the present invention, a sheet made of an elastomer is used as the base material. This sheet is a sheet having a predetermined size and a predetermined thickness so that it can be formed into a shape suitable for a head for holding a substrate in an apparatus such as a liquid crystal cell bonding apparatus. The sheet preferably has a certain thickness in the range of, for example, 1 to 3 mm. However, the size, shape, and thickness of the sheet are not particularly limited in the present invention. Examples of the elastomer constituting the sheet include synthetic rubbers such as acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPM, EPDM), fluorine rubber, silicone rubber and butyl rubber, and thermoplastic elastomers such as fluorine-based thermoplastic elastomers. Is included. In particular, fluororubber and silicone rubber are more preferable elastomer materials because they do not generate contaminants and have excellent wear resistance.

In the present invention, a fluororesin is coated on the surface of the sheet made of the elastomer. When the fluororesin itself is melt-coated, a temperature of about 400 ° C. is required, but usually, a sheet made of an elastomer cannot withstand such a high temperature. Therefore, in the present invention, a coating having a low friction coefficient is formed by fixing fine particles of a fluororesin on a sheet made of an elastomer with a latex adhesive. Fluororesins include, for example, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and the like. It is. The polytetrafluoroethylene dispersion produced by the emulsion polymerization method is a more preferred source of fine fluororesin particles in the present invention. The average particle size of the fluororesin in this dispersion is, for example, about 0.2 to 0.3 μm. Further, a fluororesin powder such as a fine powder may be used as a supply source of the fluororesin fine particles. Latex adhesives include, for example, synthetic rubber latex adhesives, vinylpyridin latex adhesives, and the like. The latex adhesive easily adheres to an elastomer material such as rubber, and firmly bonds the fine particles of the fluororesin to the sheet made of the elastomer.

The coating composed of the fluororesin fine particles and the latex adhesive is formed by coating a mixture of the fluororesin dispersion or the fluororesin powder and the latex adhesive with a sheet made of a clean elastomer by a spray method or the like. It can be formed by coating on the surface and baking. Such a mixture can include an organic solvent such as methyl ethyl ketone, a stabilizer such as a surfactant, and the like. If necessary, a pigment may be added to such a mixture. Pigments help to enhance the aesthetics of the coating. The baking after the coating can be performed at a temperature at which the sheet made of the elastomer is not denatured, for example, at a temperature of 100 ° C to 220 ° C. The baking time may be appropriately set according to the baking temperature. If the baking temperature is low, the baking time will be relatively long. During baking, the latex adhesive bonds and aggregates to the underlying sheet. Along with this, the fine particles of fluororesin gather on the outermost surface of the coating. As a result, the fine particles of the fluororesin are exposed on the surface of the coating, and a coating firmly adhered by the latex adhesive can be formed. The surface of the coating has a small friction coefficient due to the fine particles of fluororesin. The thickness of such a coating can be, for example, 1-100 μm, preferably 10-30 μm.

FIG. 1 shows a specific example of the thus-coated elastomer sheet. In the cushioning material 10 for assembling a liquid crystal cell, fine particles 12 of a fluororesin are adhered to a sheet 16 made of an elastomer such as fluororubber or silicone rubber via a layer of a latex adhesive 14. The fluororesin fine particles 12 are exposed on the surface of the cushion material 10. In the cushioning material 10, the function as a cushioning material is provided by the sheet 16 made of an elastomer, while the surface of the cushioning material 10 has a small friction coefficient due to the fine particles 12 of the fluororesin. Further, such a coating effectively prevents the surface of the sheet 16 made of the elastomer from being scraped, and effectively suppresses the generation of contaminants from the cushion material.

In the present invention, fine irregularities may be provided on the surface of the sheet made of the elastomer. Such irregularities are caused by pressing a woven fabric such as a nylon woven fabric or a polyester woven fabric or a wire mesh of, for example, 100 to 400 mesh onto the sheet surface at the time of vulcanization and pressing in the production of a sheet made of an elastomer. It can be formed by attaching a wire mesh. In this case, irregularities regularly and uniformly arranged in a mesh or cloth shape can be formed on the surface of the sheet made of the elastomer. Also, the surface may be roughened by surface treatment such as sand blasting to make the sheet uneven. The fine irregularities are provided almost uniformly over the surface on which the substrate is pressed. The average surface roughness of the sheet surface provided with such irregularities can be, for example, 10 to 20 μm. Therefore, when forming irregularities on an elastomer sheet using a woven fabric or a wire mesh, the difference in height of the irregularities formed by the molding can be set to, for example, 10 to 20 μm. The same coating as described above is applied to the surface of the sheet having the irregularities. As described above, a fluororesin dispersion or a mixture of a fluororesin powder and a latex adhesive is applied to the surface of the sheet having irregularities by a spray method or the like, and by baking, the fluororesin fine particles are removed. A coating adhered to the surface of the sheet via a latex adhesive can be obtained.

FIG. 2 shows a specific example of a cushion material in which a coating is formed on a sheet provided with irregularities. In the liquid crystal cell assembling cushion material 20 shown in FIG. 2, irregularities are formed on the surface of a sheet 26 made of an elastomer. The fine particles 22 of the fluororesin are adhered via a latex adhesive layer 24 to the surface of the sheet 26 on which the irregularities are formed substantially uniformly. The fine particles 22 of the fluororesin are exposed on the surface of the cushion material 20. In the cushioning material coated on the sheet with the unevenness as described above, the generation of contaminants is effectively suppressed by the coating, and the surface has a small friction coefficient. In addition, the surface of the cushioning material has irregularities distributed almost uniformly. The area where the uneven surface comes into contact with the substrate is smaller than the area where the surface without unevenness comes into contact with the substrate, and therefore the surface with the unevenness has a smaller frictional resistance to the substrate. ing. With such irregularities and the fluororesin, the coefficient of friction can be made smaller.

[0017]

【Example】

 Example 1 A molded and vulcanized fluororubber sheet having a thickness of 2 mm was cut into a predetermined size so as to fit a glass substrate holding portion of a liquid crystal cell bonding apparatus, and the surface was cleaned by cleaning and dried. . A mixture of a polytetrafluoroethylene dispersion having an average particle size of about 0.2 μm, a synthetic rubber latex adhesive, and a pigment is prepared, and the resulting mixture is uniformly applied to one of the main surfaces of a fluororubber sheet by a spray method. Was. Next, baking was performed at a temperature of 200 ° C. to obtain a coating in which polytetrafluoroethylene fine particles having an average particle size of about 0.2 μm were adhered with a synthetic rubber latex adhesive. The thickness of the coating firmly adhered to the fluororubber sheet was about 20 μm. In this way, a cushion material for assembling a liquid crystal cell having a small friction coefficient of the working surface was obtained by the fine particles of fluororesin. The obtained cushioning material was cut into an appropriate shape, mounted on a liquid crystal cell bonding device, and the glass substrate bonding process was performed.The cushioning material did not contaminate the glass substrate and the glass substrate surface was not contaminated. It was confirmed that the pressure between the two glass substrates could be kept uniform by applying a uniform pressure, which could contribute to the improvement of the quality of the liquid crystal cell and the workability of the assembling process.

Example 2 A 2 mm-thick fluororubber sheet having a textured uniform unevenness formed on its surface by pressing a nylon woven fabric during vulcanization and pressing is fitted to the glass substrate holding portion of the liquid crystal cell bonding apparatus. It was cut into a predetermined size, and its surface was washed and dried. Average particle size about 0. A mixture of a 2 μm polytetrafluoroethylene dispersion, a synthetic rubber latex adhesive, and a pigment was prepared, and the resulting mixture was applied to the surface of a fluororubber sheet having irregularities by a spray method. Baking was performed at a temperature of 200 ° C. to obtain a coating in which fine particles of fluororesin were adhered by a latex adhesive. The thickness of the coating was about 25 μm. In this way, a cushion material for assembling a liquid crystal cell having a uniform cloth-like unevenness on the surface and a reduced friction coefficient on the surface was obtained. FIG. 3 schematically shows a sectional structure of the obtained cushion material. In FIG. 3, the thickness of the fluororesin particles and the thickness of the coating are larger than the actual ones in order to facilitate understanding of the structure, and the dimensions are different from the actual ones. In the cushioning material 30 for assembling the liquid crystal cell, the fluororubber sheet 36 is formed with irregularities uniformly distributed. Polytetrafluoroethylene fine particles 32 are adhered to the surface on which the irregularities are formed via a latex adhesive layer 34. The fine particles 32 of the fluororesin are exposed on the surface of the cushion material 30 having the unevenness. FIG. 4 shows the overall appearance of the cushioning material. The cushion material 30 has a size suitable for the substrate holding part of the liquid crystal cell bonding apparatus. When such a cushion material is used in a liquid crystal cell bonding apparatus or the like, it can be cut into a more appropriate shape and used. The obtained cushioning material was cut into an appropriate shape, mounted on a liquid crystal cell bonding device, and the glass substrate bonding process was performed.The cushioning material was pressed uniformly without contaminating the glass substrate. As a result, it was confirmed that the thickness between the two glass substrates could be kept uniform, which could contribute to the improvement of the quality of the obtained liquid crystal cell and the workability of the assembling process.

[0019]

[Effect of the invention]

 According to the present invention, there is provided a cushioning material for assembling a liquid crystal cell capable of uniformly applying a force to a substrate without contaminating the substrate in a process involving pressing the substrate, such as a substrate bonding process and a film bonding process. can do. The cushioning material according to the present invention can contribute to quality improvement and workability improvement in a liquid crystal cell manufacturing process.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a cross-sectional structure of a specific example according to the present invention.

FIG. 2 is a diagram schematically illustrating a cross-sectional structure of another specific example according to the present invention.

FIG. 3 is a diagram schematically illustrating a cross-sectional structure of a cushion material obtained in an example.

FIG. 4 is a perspective view showing an appearance of a cushion material obtained in an example.

[Explanation of symbols]

 10, 20, 30 Cushion material for liquid crystal cell assembly 12, 22, 32 Fine particles of fluororesin 14, 24, 34 Latex adhesive layer 16, 26, 36 Sheet made of elastomer

Claims (5)

[Utility model registration claims] 1. A cushioning material used when applying pressure to a substrate constituting a liquid crystal cell in a process of assembling the liquid crystal cell, wherein a fine particle of a fluororesin is bonded to a sheet made of an elastomer by a latex adhesive. Wherein the surface to which the fine particles of the fluororesin are adhered is an operating surface when applying pressure to the substrate, wherein the cushioning material is used for assembling a liquid crystal cell. 2. The fluororesin is selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer and tetrafluoroethylene-perfluoroalkylvinyl ether copolymer. 2. The method according to claim 1, wherein the at least one elastomer is at least one selected from the group consisting of fluoro rubber, silicone rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber and butyl rubber. The cushioning material for assembling a liquid crystal cell according to the above. 3. A cushioning material used when applying pressure to a substrate constituting a liquid crystal cell in a process of assembling the liquid crystal cell, wherein the surface is provided with fine irregularities made of an elastomer and distributed almost uniformly. The sheet has a structure in which fine particles of fluororesin are bonded by a latex adhesive, and the surface to which the fine particles of fluororesin are bonded is an operating surface when applying pressure to the substrate. , Liquid crystal cell assembly cushion material. 4. The fluororesin is selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer and tetrafluoroethylene-perfluoroalkylvinyl ether copolymer. 4. The method according to claim 3, wherein said at least one elastomer is at least one selected from the group consisting of fluoro rubber, silicone rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber and butyl rubber. 3. The cushioning material for assembling a liquid crystal cell according to item 1. 5. The cushion material for assembling a liquid crystal cell according to claim 3, wherein the unevenness is provided in a mesh shape or a cloth shape.