| 摘要 |
PROBLEM TO BE SOLVED: To obtain low-density EPDM-based foam having small cell diameter, having small permanent compression set, excellent in restoring force of volume of thickness, etc., and as necessary, capable of readily carrying out foam- breaking treatment by carrying out crosslinking and foaming treatment using an organic peroxide and a foaming agent. SOLUTION: This EPDM-based foam comprises crosslinked foam of an EPDM-based composition obtained by compounding EPDM with at least an organic peroxide, a foaming agent and a softening agent, and has <=0.5 g/cm3 density and <=0.5 N/cm2 stress in 50% compression, and in the foam, a permanent compression set obtained when 50% compression state is continued for 22 hr at 100 deg.C and the compression state is released and allowed to stand for 3 day at room temperature is <=20%. This method for producing EPDM-based foam comprises heating the EPDM-based composition in which compounding amount of the softening agent is <=50 wt.% based on EPDM to carry out crosslinking and foaming treatment and further carrying out secondary crosslinking treatment of the treated composition at a higher temperature than temperature in the crosslinking and foaming treatment. |
