| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing forming material for an automatic transmission having a little dependence on another metal surface roughness in terms of the self abrasion by mixing a prescribed quantity of graphite powder having a prescribed hardness to polytetrafluoroethylene resin. SOLUTION: Polytetrafluoroethylene(PTFE) resin composition composed of 60-97 pts.wt. PTFE resin and 3-40 pts.wt. graphite powder of Shore hardness 45 or more is used for a sealing forming material for an automatic transmission. The graphite of the mean grain size approximately 35μm or less, preferably 13-20μm is used. The composition is prepared by mixing the PTFE resin and the graphite powder using a mixer such as a Henschel mixer and a universal mixer, the mixture is held under the forming pressure approximately 49-88 MPa for approximately 1-3 minutes and preformed into, for example, a cylindrical shape, then burned at approximately 350-390 deg.C for approximately 1-6 hours, and the burned material is formed by being worked into a thin-wall sheet.
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