| 摘要 |
The present invention relates to a process for producing a polystyrene, in particular a process for producing a high impact polystyrene, which process comprises:
1) introducing into a pre-inversion reactor a styrene monomer, a rubber polymer and a grafting promoter, and polymerising the styrene monomer to form a polystyrene, said polymerisation being performed to a conversion of between 70 and 100% of the phase inversion start point of the styrene/polystyrene/rubber polymer mixture formed,
2) splitting the formed styrene/polystyrene/rubber polymer mixture to produce a first stream comprising 70 to 95% by weight of the formed mixture and a second stream comprising the balance of the formed mixture,
3) introducing the first stream into a second reactor wherein further styrene polymerisation is performed to cause phase inversion the first stream,
4) mixing the phase inverted first stream from step (3) with the second stream from step (2) at a shear rate of 5 to 30 s -1 in a static in-line mixer to cause a second phase inversion and produce a high impact polystyrene with a bimodal distribution of rubber particles.
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