PURPOSE: The titled composition, prepared by incorporating a hydrate of an inorganic metallic oxide and an inorganic metallic borate with a polyolefin resin modified with a silane, and crosslinking the resultant mixture without causing noxious gases, dripping in combustion nor deforming nor melting even at a high temperature in a short time, and suitable for electric wires, etc.
CONSTITUTION: A flame-retardant resin composition prepared by incorporating 100pts.wt. polyolefin resin modified with a silane, obtained by grafting 1W 100pts.wt. organosilane expressed by the formula RR'SiY2 (R is monofunctional olefinically unsaturated hydrocarbon or hydrocarboxyl; Y is hydrolyzable organic group; T' is monofunctional hydrocarbon other than aliphatic unsaturated hydrocarbons or the same as Y) and 0.0002W0.002 mole, based on 100g regin, compound capable of forming free radicals onto 100pts.wt. polyolefin with 20W 100pts.wt. hydrate of an inorganic metallic oxide, 1W50pts.wt. inorganic metallic borate and if necessary 2W50pts.wt. red phosphorus type flame retardant, and bringing the resultant mixture into contact with water to crosslink (10W50% crosslinking degree) without using a silanol condensation catalyst.