| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foam capable of suppressing the retardation caused when allowing the foam to stand in a shrunk state, and excellent in delayed shape recovery properties. SOLUTION: This foam is obtained by heating and kneading 100 pts.wt. olefinic thermoplastic elastomer, 5 pts.wt. azodicarbonamide and 0.7 pts.wt. zinc oxide, forming the kneaded material into a sheet, cross-linking the obtained sheet by an electron beam irradiation to provide a raw sheet, which has 17% damping factor of a stress, heating and foaming the raw sheet to provide a raw foam, compressing a cut fragment of the raw foam and keeping the compressed state for 24 hr to provide the objective shape recovery foam. The shape recovery foam is allowed to stand in a state nipped between pressing plates at 40 deg.C for five days, thereafter taken out from the pressing plates and allowed to stand at the room temperature for 30 days to recover the shape. The shape recover rate is 68%. |
