| 摘要 |
PURPOSE:To obtain a sponge having excellent processing stability and good surface skin by vulcanizing a specified sponge composition based on an ethylene/alpha-olefin/nonconjugated diene rubber by irradiation with electron beams. CONSTITUTION:A molding of a sponge composition based on an ethylene/alpha-olefin/nonconjugated diene rubber of a scorch time >=5min is irradiated with electron beams. This molding is vulcanized and expanded by heating. According to the above process, a sponge of a high expansion ratio and a good surface skin can be obtained because a crosslinked layer which is the same in appearance as the surface layer of the rubber molding is formed by electron beam crosslinking before the vulcanization and expansion of its inside layer proceed. Said sponge composition contains said rubber as a principal component and may further contain a relatively small amount of another synthetic rubber, natural rubber, synthetic resins, fillers, processing aids, softeners, antioxidants, etc. |
