METHOD FOR PREPARING FIRE RETARDANT MOLDING COMPOSITIONS

摘要

APPLICATION FOR LETTERS PATENT FOR A METHOD FOR PREPARING FIRE RETARDANT MOLDING COMPOSITIONS Disclosed herein is a method for preparing fire retardant styrenic polymer molding compositions with improved impact strength which compositions contain a metal oxide and a halogenated fire retardant additive. The method comprises dispersing the metal oxide into a minor portion of the styrene polymer component using high intensity mixing and temperatures at or above the fusion temperature of the styrene polymer in order to obtain a uniform dispersion. The metal oxide-polystyrene dispersion is then blended with the other ingredients of the polyblend. The resulting blend is compounded at temperatures greater than 255.degree.C. and then comminuted to form a molding composition.