FLAME RETARDANT AND FLAME-RETARDANT THERMOPLASTIC RESIN COMPOSITION CONTAINING THE FLAME RETARDANT

摘要

PROBLEM TO BE SOLVED: To provide a flame retardant having high thermal stability and excellent in flowability, and a thermoplastic resin composition having high flame retardancy and improved in thermal stability so that it undergoes little change in the molecular weight of polymer during extrusion or injection molding. SOLUTION: This flame retardant comprising a brominated epoxy resin has a structure obtained by reacting a diglycidyl ether of a brominated bisphenol compound by using a brominated bisphenol compound having an alkali metal ion content of at most 5 ppm, or reacting a brominated bisphenol compound with an epihalohydrin and subjecting the reaction product to sufficient water washing, or blocking 30-100 mol.% of the epoxy groups of the aforementioned brominated epoxy resin with tetrabromobisphenol(TBP). The electric conductivity of the water extract thereof is at most 5μS/cm. The flame-retardant resin composition is obtained by blending 100 pts.wt. thermoplastic resin containing carbonyl bond(s) in the main polymer chain with 1-40 pts.wt. flame retardant comprising the brominated epoxy resin.