| 摘要 |
PROBLEM TO BE SOLVED: To readily and simply carry out both a reduction in friction on the surface of a molded product and a change of the surface thereof into a nontacky state by irradiating a vulcanized rubber molded product with electron beams at a specific value or below of acceleration voltage in an atmosphere at a specific oxygen concentration at the time of irradiation. SOLUTION: A vulcanized rubber molded product (e.g. a primary or secondarily vulcanized molded product of a synthetic rubber such as a fluororubber, an acrylic rubber or a silicone rubber or a natural rubber) is irradiated with electron beams at <=300 kV acceleration voltage in an atmosphere at 10-500 ppm (vol.) oxygen concentration at the time of irradiation to thereby carry out the surface treatment of the vulcanized rubber molded product. The regulation of the oxygen concentration at the time of irradiation is preferably carried out by simultaneously making an inert gas flow. For example, 100 pts.wt. of a fluororubber is kneaded with 20 pts.wt. of MT carbon black, 15 pts.wt. of magnesium oxide and 3 pts.wt. of a vulcanizing agent and the resultant kneaded material is then vulcanized and molded into a sheetlike form. The resultant molded product is subjected to irradiation treatment with electron beams under conditions of 250 kV acceleration voltage, 300 Mrad irradiation dose, about 10 s irradiation time and 100 ppm oxygen concentration at the time of irradiation.
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