| 摘要 |
PURPOSE: To provide expandable polypropylene resin particles which can give a foam which is prevented from causing chipping, cracking, etc., of the particles around the cut part by dispersing specified base resin particles in a dispersion medium in a sealed container, feeding a volatile blowing agent into the container, heating the entire mixture, and releasing the mixture into a low-pressure zone. CONSTITUTION: A propylene/2-8 Cα-olefin copolymer is mixed with at least one ethylene copolymer selected from among an ethylene/α-olefin copolymer resin of a density of 0.87-0.93g/cm<3> , an ethylene/α-olefin copolymer rubber of a Mooney viscosity of 15-90 and an ethylene copolymer containing 3-30wt.% unsaturated ester or ether as a comonomer to obtain a polypropylene resin having a bending rigidity (JIS-K7106) of 4000-8000kg/cm<2> . A base resin prepared by mixing this resin with 0.05-3.0wt.% metal salt of a fatty acid and 0.05-2.0wt.% fatty acid amide is dispersed in a dispersion medium, and the resulting dispersion is placed in a sealed container. A volatile blowing agent is fed to the container and the resulting mixture is heated to or above the softening point of the base resin and released into a low-pressure zone. |
