Process for the preparation of a flame retardant styrenic resin

Abstract

The present invention provides a process for preparing a flame retardant styrenic resin which comprises: (1) an initiation step wherein 3 to 10 parts by weight of a bromostyrene compound, 10 to 25 parts by weight of styrene, 5 to 10 parts by weight of an unsaturated nitrile, 0.01 to 0.5 part by weight of a chain transfer agent and 0.01 to 1.0 part by weight of an initiator are introduced to a polymerization reactor and polymerized until the conversion reaches 30 to 50%; (2) a control step wherein 10 to 35 parts by weight of a bromostyrene compound, 20 to 50 parts by weight of styrene, 5 to 20 parts by weight of an unsaturated nitrile, 0.01 to 1.0 part by weight of an initiator and 0.01 to 0.5 part by weight of a chain transfer agent are introduced to the reactor in one or more divisions in accordance with the progress of said polymerization until the conversion reaches 80 to 90%; and (3) an optimization step wherein 3 to 10 parts by weight of styrene, 5 parts by weight or less of an unsaturated nitrile, 0.01 to 0.3 part by weight of a chain transfer agent and 0.01 to 0.5 part by weight of an initiator are introduced to the reactor until the polymerization is completed.

Dependencies are inferred from the claim text.