Flame retardant pre-expanded polymer material, in-mold or extruded foamed article and process for producing the material

摘要

This invention provides a flame retardant pre-expanded polymer material comprising:
(A) a thermoplastic polymer material;
(B) an organic phosphorus-containing compound; and
(C) a hindered amine having an OR group substituted directly on its N-atom, wherein R is a saturated or unsaturated hydrocarbyl group;
wherein the phosphorus-containing compound (B) is not a phosphoric ester or a phosphate, and wherein the weight ratio (B)/(C) is from 1.9 to 10. This invention also provides a process for producing the material, and a foamed article prepared by in-mold foaming or extrusion-foaming the material.