Patent Application
20080021134
One embodiment of the present invention will be described hereinafter.
Glass paper having a thickness of 0.1 to 1.0 mm and formed of a fiber material is prepared. The glass paper is provided by forming a sheet using a glass fiber having a diameter of 3 μm to 15 μm and a length of 5 mm to 30 mm and formed by a wet papaermaking method. Such glass paper is available in the market as “Grabestos” (produced by Oribest Co., Ltd), “Cumulus” (produced by Japan Vilene Co., Ltd) and the like.
Then, the glass paper is permeated with unvulcanized fluoro rubber solution. The unvulcanized fluoro rubber solution can be adjusted by dissolving an unvulcanized fluoro rubber into a solvent such as ethyl acetate, n-butyl acetate and methyl ethyl ketone so that its solid content concentration may become 10% to 50%. The glass paper is permeated with the unvulcanized fluoro rubber solution sufficiently by coating the unvulcanized fluoro rubber solution on the glass paper or by immersing glass paper in the unvulcanized fluoro rubber solution. According to need, the glass paper permeated with the unvulcanized fluoro rubber solution is rolled by a roll to adjust an impregnated amount of the unvulcanized fluoro rubber solution.
Then, the glass paper permeated with the unvulcanized fluoro rubber solution is dried to remove the solvent of the fluoro rubber.
Then, the glass paper permeated with the unvulcanized fluoro rubber is heated at 160° C. to 250° C. for 15 minutes to 10 hours to vulcanize the fluoro rubber, whereby a hot-press cushion material is provided. The fluoro rubber is preferably vulcanized in a non-compressed condition to ensure a sufficient void in the hot-press cushion material.
In addition, the volume ratio between the fiber material and the rubber in the paper-rubber complex can be 1/1.5 to 1/7.5 and the void ratio can be 60% to 90% by appropriately selecting and adjusting the material quality and grade of the paper, the material quality of the rubber, the solid content concentration of the rubber solution, the roll amount before dried and the like. When the hot-press cushion material according to the present invention is used for the hot pressing of a laminated plate, only one sheet of the cushion material may be used or two to five laminated sheets of the cushion materials may be used. In another case, the hot-press cushion material may comprise the layer of the cushion material according to the present invention and another material layer such as a rubber or a surface detachment type film in a laminated structure.
Samples 1 to 22 were provided under various different conditions.
As the paper formed of the fiber material, the glass paper “grabestos” (produced by Oribest Co., Ltd) that was formed into a sheet with E glass fibers (its fiber diameter is 9 μm and fiber length is 13 mm) by the wetapapermaking method was used. Two kinds of glass paper, the one having a basis weight of 53 g/m2 and thickness of 0.46 mm (samples 1 to 9) and the one having a basis weight of 80 g/m2 and thickness of 0.64 mm (samples 10 to 22) were used.
Meanwhile, the unvulcanized fluoro rubber solution having a solid content ratio of 30.8% formed by dissolving an unvulcanized rubber in a solvent of butyl acetate was prepared.
Thus, each glass paper was immersed in the unvulcanized fluoro rubber solution and rolled by two rolls. Thus, the glass paper was permeated with the unvulcanized fluoro rubber solution so that the solid content amount of the unvulcanized fluoro rubber might have a volume ratio shown in Table 1. Then, the glass paper permeated with the unvulcanized fluoro rubber solution was sufficiently dried to remove the solvent. Then, the glass paper containing the unvulcanized fluoro rubber was heated in an oven under a non-compressed condition at 230° C. for five hours to vulcanize the unvulcanized fluoro rubber. The rubber/fiber volume ratio and the void ratio of each sample are as shown in Table 1.
Since each sample is formed of paper as a base material, its fiber is oriented in a surface direction and the thickness per sheet is small, so that it is clear in view of its structure that in-plane uniformity and heat conductivity that are in no way inferior to a paper cushion material such as the kraft paper can be provided.
The cushion characteristics were measured with respect to each sample. According to a method of measuring the cushion characteristics, the sample was put in between hot plates at a temperature of 200° C. and after preheated for two minutes, a pressure was applied to the sample from 0 MPa to 4 MPa at a pressure rising speed of 1 mm/minute. Thus, the amount of variation in thickness was measured and this was used as the indicator of the cushion characteristics.
In addition, the pressing is repeated under the same condition and the variations in cushion characteristics were measured. The initial cushion characteristics, the cushion characteristics after one press, the cushion characteristics after ten presses are shown with respect to each sample in Table 1.
The cushion characteristics of the kraft paper having a basis weight of 190 g/m2 and a thickness of 0.31 mm were measured for reference and shown in Table 1 also. According to the kraft paper, the material was fractured due to carbonization of the fiber at the third press and did not function as the cushion material any more.
According to the samples 1 to 22, the ratio between the fiber material and the rubber is ranged within 1/1.5 to 1/7.5. Among them, the samples 3 to 7 and 12 to 19 satisfy that the void ratio as a whole is within a range of 60% to 90% and each of them is preferable in initial cushion characteristics and cushion characteristics after repeatedly used.
In addition, the samples 4 to 6 and 14 to 17 satisfy that the volume ratio between the fiber material and the rubber is within a range of 1/2.5 to 1/6 and the void ratio as a whole is within a range of 60% to 90% and each of them is preferable in initial cushion characteristics and its lowering degree of the cushion characteristics is low after repeatedly used, so that they have superior material properties as the hot-press cushion material especially.
Although the embodiments of the present invention have been described with reference to the drawings in the above, the present invention is not limited to the above-illustrated embodiments. Various kinds of modifications and variations may be added to the illustrated embodiments within the same or equal scope of the present invention.
The present invention can be advantageously applied to the cushion material used when an object is press formed or hot pressed in a manufacturing process for a laminated plate such as a copper clad laminated plate, a flexible printed substrate, a multilayered printed substrate, an IC card, a liquid crystal display plate, and a ceramics laminated plate, and also advantageously applied to the manufacturing method of the above cushion material.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-195985 | Jul 2006 | JP | national |
