摘要 |
In a process for producing a high impact polystyrene comprising the radical polymerization of styrene in the presence of a butadiene rubber, the improvement which comprises, the butadiene rubber being a highly branched polymer prepared by homopolymerizing 1,3-butadiene or copolymerizing 1,3-butadiene and styrene in the presence of an organolithium compound and a Lewis base compound, followed by further reacting the resulting polymer with a multifunctional halogen compound; in the butadiene rubber, the average content of 1,2-bonds being 18 to 32 mole % based on the total bonded butadiene, the content of bonded styrene being up to 10% by weight, and the content of branched polymer chains being at least 60% by weight; the butadiene rubber exhibiting a Mooney viscosity of 40 to 90 at 100 DEG C. and a solution viscosity in styrene of 60 to 90 cps at 25 DEG C. and at a concentration of 5% by weight; and the styrene polymerization being carried out so that the content of the butadiene rubber in the product polystyrene lies between 3 and 20% by weight.
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