| abstract |
A heat-foamable crosslinked propylene resin composition in the form of a melt-shaped structure comprising n (1) 100 parts by weight of a crosslinked propylene resin composition obtained by mixing at least four components composed of (A) a propylene resin containing 0 to 30 mole% of an alpha-olefin other than propylene and having a melt flow rate (MFR), determined by ASTM D1238L, of 0.1 to 50 g/10 min., (B) an olefin resin which is a propylene random copolymer resin (81) composed of 55 to 85 mole% of propylene and 15 to 45 mole% of an alpha-olefin with 4 to 20 carbon atoms and having an amount of heat of crystal fusion, determined by thermal analysis on a differential scanning calorimeter, of 25 to 70 joules/g and a melt flow rate (MFR), determined by ASTM D1238L, of 0.05 to 20 g/10 min. or a 1-butene homo-polymer or a 1-butene random copolymer resin (B2) composed of 70 to 100 mole% of 1-butene and 0 to 30 mole% of an alpha olefin having 2, 3 or 5 to 20 carbon atoms and having an amount of heat of crystal fusion, determined by thermal analysis on a differential scanning calorimeter of 20 to 70 joules/g and a melt flow rate (MFR), determined by ASTM D1238L, of 0.05 to 50 g/10 min., 0.05 to 0.5 parts by weight, per 100 parts by weight of the resins (A) and (B) combined, of a radical initiator (C) and 0.1 to 1 part by weight, per 100 parts by weight of the resins (A) and (B) combined, of (D) a crosslinking agent at a temperature at which the radical initiator decomposes to form the |