PURPOSE: To impart high flame retardance safely and easily, by blending a specified amount of a flame-retardant compsn. consisting of a styrene/acrylonitrile copolymer and red phosphorus powder which has been impregnated with a thermosetting resin and then cured, with a thermoplastic resin.
CONSTITUTION: Styrene and acrylonitrile are copolymerized in such an amount as to give an acrylonitrile content of 10W40wt%, to which is added, pref., a rubber component such as polybutadiene to obtain a styrene/acrylonitrile copolymer (A). Red phosphorus powder having an average particle size of 0.1W 100μ is impregnated with a thermosetting resin such as phenolic resin, which is then cured. Component A and the resulting red phosphorus powder are mixed together in such a proportion as to give a red phosphorus content of 20W70wt% in terms of elementary red phosphorus. The resulting flame-retardant compsn. is blended with a thermoplastic resin such as polyester or polyamide in such an amount as to give a phosphorus content of 0.5W20wt% in terms of elementary red phosphorus, whereby the thermoplastic resin is made flame-retardant.
KUBOTA YOSHIAKI
KISHIDA YASUO
KANEBO GOSEN KK