METHOD FOR PRODUCING EXPANDED OR EXPANDABLE POLYOLEFIN PARTICLES

摘要

The invention relates to a method for producing expanded or expandable polyolefin particles, by impregnating polyolefin granulate with a volatile propellant in suspension under pressure. A mixture of a water-insoluble inorganic compound and a surfactant is used as a suspending auxiliary agent and the impregnation takes place in the presence of a surface-active polymer which carries carboxyl or carboxylate groups.