| 摘要 |
PURPOSE: To decrease influences of thermal expansion during vulcanization molding, to reduce the amount of inverse crown and to obtain stable dimensional accuracy by using t-butylperoxy-2-ethylhexalate as a vulcanizing agent for silicone rubber. CONSTITUTION: This pressure roller has 50mm outer diameter and consists of a metal core, 5-mm thick rubber layer around the core metal and a fluorocarbon resin tube of 50μm thickness covering the rubber layer. The roller is formed by using a cylindrical mold with a straight inner shape. By using t-butylperoxy-2-ethylhexalate as a vulcanizing agent, the vulcanizing temp. to obtain 90% vulcanization can be decreased by 30 to 40 deg.C compared to a method using a conventional vulcanizing agent. Further, the obtd. rubber has comparable physical properties as a rubber although it has low hardness than a rubber using a conventional vulcanizing agent. Namely, since vulcanization can be performed at lower temp. than a conventional method, the shrinkage ratio of the product can be decreased and influences of thermal expansion during vulcanization molding can be reduced.
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