FLAME-RETARDANT STYRENE RESIN PARTICLE AND METHOD FOR PRODUCING THE SAME, FOAMABLE PARTICLE, FOAMING PARTICLE, AND FORMED-MOLDED BODY

摘要

PROBLEM TO BE SOLVED: To provide flame-retardant styrene resin particles which provide a foamed-molded body that highly achieves both flame retardancy and internal fusion.SOLUTION: Flame-retardant styrene resin particles are constituted by at least a styrene resin and a phenoxyphosphazene compound as a flame retardant. The phenoxyphosphazene compound is (i) a compound in which a phenoxy group is bonded to a substitutable binding site of a phosphorus atom constituting the phenoxyphosphazene compound; (ii) when the amount of the phenoxyphosphazene compound contained in all the flame-retardant styrene resin particles is represented by X mass%, and the amount of the phenoxyphosphazene compound contained in the surface layer is represented by Y mass% with respect to the total amount of the styrene resin particles and the phenoxyphosphazene compound, the phenoxyphosphazene compound is contained in the flame-retardant styrene resin particles so as to satisfy a relationship of Y>X; and (iii) X mass% of 0.3 to 40 mass% of the phenoxyphosphazene compound is contained in the flame-retardant styrene resin particles.