FLAME-RETARDANT EXPANDABLE STYRENE RESIN PARTICLES AND METHOD FOR PRODUCING SAME

摘要

Flame-retarded foamable styrene-based resin beads and a process for producing the resin beads are provided in which a combination of two organic bromine-containing compounds is used in order to accomplish a high flame retardancy level with a small amount of addition and decreased level of residual monomer. The flame-retarded foamable resin beads comprises a blowing agent added to resin beads by impregnating with the blowing agent during or after polymerization. The beads are produced by suspension polymerizing a monomer composition containing 0.5 to 5.0 parts by weight per 100 parts by weight of the monomer of a bromine-containing flame retardant comprising (a) an organic bromine-containing compound having 2,3-dibromo-2-alkylpropyl group and (b) an organic bromine-containing compound having a bromine content greater than 50 wt% and free of any bromine atom attached to a tertiary carbon atom.