CONTINUOUS BULK POLYMERIZATION PROCESS OF RUBBER-MODIFIED TRANSPARENT STYRENIC RESIN HAVING UNIFORM COMPOSITION, GOOD TRANSPARENCY AND HIGH IMPACT STRENGTH

摘要

A method for preparing a rubber modified styrene-based resin by continuous mass polymerization, and a transparent rubber modified styrene-based resin prepared by the method are provided to improve transparency and impact resistance and to enhance the uniformity of composition. A method for preparing a rubber modified styrene-based resin comprises the steps of injecting 100 parts by weight of a monomer mixture comprising 30-55 wt% of a styrene-based monomer and 45-70 wt% of a methyl methacrylate-based monomer, 5-14 parts by weight of a styrene-butadiene copolymer, and 10-30 parts by weight of a reaction medium into a first reactor and reacting it at 90-120 deg.C for 1-2 hours to prepare a first polymer product having a conversion rate of 20-40 %; injecting the first polymer product into a second reactor, and polymerizing it with adding 6 parts by weight or less of a styrene-based monomer or a methyl methacrylate-based monomer based on 100 parts by weight of the monomer mixture used in the first reactor at 110-140 deg.C for 1-3 hours to prepare a second polymer product having a conversion rate of 40-70 %; and injecting the second polymer product into a third reactor, and reacting it with adding 6 parts by weight or less of a styrene-based monomer or a methyl methacrylate-based monomer based on 100 parts by weight of the monomer mixture used in the first reactor and 0.005-0.03 parts by weight of the polydimethylsiloxane having a viscosity of 10-100 cSt at 25 deg.C based on 100 parts by weight of the final resin at 120-160 deg.C for 1-3 hours to prepare a second polymer product having a conversion rate of 70-95 %.