METHOD FOR PREPARING FLAME-RETARDANT PROPYLENE-BASED RESIN COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing a composition which hardly causes a burnt mark on a molded article molded by an injection molding machine.SOLUTION: A method for preparing a flame-retardant propylene-based resin composition comprises the steps of: melting and kneading a mixture of 80-98.9 mass% of a flame-retardant component (on condition that hydrotalcite is excluded) (a) containing tetrabromobisphenol S-bis(2,3-dibromopropyl ether), 0.1-10 mass% of hydrotalcite (b) and 1-10 mass% of a thermoplastic resin (c) (on condition that a propylene-based resin to be used at the following step is excluded) having 60-160°C melting point, cooling the melted and kneaded mixture, and cutting the cooled mixture to obtain a mixture pellet; melting and kneading 100 pts.mass of the propylene-based resin and 5-30 pts.mass of the mixture pellet; and cooling an obtained melted and kneaded material and cutting an obtained cooled material to obtain a pellet of the objective flame-retardant propylene-based resin composition.