Flame-retarded thermoplastic compositions of high thermomechanical strength, in particular for electric cables

摘要

A flame-retarded thermoplastic composition including a graft copolymer containing polyamide blocks and composed of a polyolefin backbone and on average at least one polyamide graft, in which the grafts are attached to the backbone by the residues of an unsaturated monomer (X) having a function capable of reacting with a polyamide, the residues of the unsaturated monomer (X) are attached to the backbone by grafting or copolymerization from its double bond, wherein the composition includes: —between 60% and 70% by weight of the graft copolymer containing polyamide blocks, —between 22% and 28% by weight of poly(pentabromobenzyl acrylate), —between 4% and 8% by weight of a synergistic flame retardant chosen from antimony trioxide, derivatives of tin, of molybdenum and/or bismuth and also boron and zinc oxides, calcium borates, calcium sulphate and/or zinc stannate, between 0.5% and 5% by weight of organophilic treated clay.

主权项

1. A flame-retardant thermoplastic composition comprising a polyamide-block graft copolymer consisting of a polyolefin backbone and, on average, at least one polyamide graft wherein the grafts are attached to the backbone by the residues of an unsaturated monomer (X) having a function capable of reacting with a polyamide, the residues of the unsaturated monomer (X) are attached to the backbone by grafting or copolymerization via its double bond, wherein the composition comprises:
between 60% and 70% by weight of the polyamide-block graft copolymer, between 22% and 28% by weight of poly(pentabromobenzyl acrylate), between 4% and 8% by weight of a synergistic flame retardant selected from the group consisting of at least one of antimony trioxide, antimony oxide, antimony sulfide, derivatives of tin, derivatives of molybdenum, derivatives of bismuth, boron, zinc oxides, calcium borates, calcium sulfate and zinc stannate, between 0.5% and 5% by weight of a clay intercalated by a swelling agent.