Oblon, Spivak, McClelland, Maier & Neustadt
Propylene resin foamed particles and foamed mold article
 Foamed particles of a propylene resin are described which comprises, as a base resin, a random copolymer of propylene and 1-butene, said random copolymer having a 1-butene content of from 3 to 12% by weight. A foamed mold article is also described which is composed of a random copolymer of propylene and 1-butene, and having a density of from 0.015 to 0.09 g/cm.sup.3. A bumper core material for use in automobile bumpers is also discribed which is composed of a foamed mold article of a random copolymer of propylene and 1-butene, said random copolymer having a 1-butene content of from 3 to 12% by weight, said foamed mold article having a density of from 0.02 to 0.08 g/cm.sup.3, a compression stress at 50% compression as measured at 20.degree. C. of 2.5 to 10 kg/cm.sup.2, and an energy absorption efficiency as measured at 20.degree. C. of 60 to 90% the ratio (E.sub.80 /E.sub.20) of the amount of the energy absorption of said foamed mold article as measured at 80.degree. C. (E.sub.80) to the amount of the energy absorption of said foamed mold article as measured at 20.degree. C. (E.sub.20) being 0.5 to 0.9. 
Mitsubishi Yuka Badische Co., Ltd.
Y C Y C B
Y10T C08J Y10T C08J B60R
additional additional additional inventional inventional
Masakazu Toshihiro Hiroshi Toshio Shigeki Masanori Masanori
Arai Gotoh Endo Yagi Mathuno Tanaka Saito