After the polypropylene regin preexpansion grain null polypropylene regin grain where

摘要

PROBLEM TO BE SOLVED: To stably provide prefoamed polypropylene resin particles free from the generation of harsh high-frequency friction noise (squeaky noise) in the case of generating friction between prefoamed particles, foamed articles, or a foamed article and other plastic articles, metallic articles, etc.;SOLUTION: The prefoamed polypropylene resin particle is produced from polypropylene resin particle containing 0.1-5 pts.wt. of a fatty acid bisamide based on 100 pts.wt. of a polypropylene resin having a prescribed flexural modulus, by charging the resin particle together with a dispersing agent, a dispersion assistant and a foaming agent to a pressure vessel, heating the content of the vessel and discharging the content to an atmosphere having pressure lower than the pressure in the pressure vessel. The fusion of the foamed article obtained by in-mold forming can be improved by the use of a polyvalent anion as the dispersion assistant because the dispersion of the resin particles in the pressure vessel is stabilized and the amount of the dispersion left on the surface of the prefoamed particle is decreased.;COPYRIGHT: (C)2008,JPO&INPIT