| 摘要 |
1,174,214. High impact polystyrene. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 5 April, 1968 [7 April, 1967], No. 16470/68. Heading C3G. A high impact polystyrene composition comprises (a) as the continuous phase, 70-99 parts by weight of polystyrene and (b) as a discontinuous elastomer gel phase dispersed therethrough, 30-1 parts by weight of a diene elastomer-styrene interpolymer phase wherein (1) 70-97% by weight of the dispersed phase have particle sizes of 1-3 microns diameter and (2) 30-3% by weight of the dispersed phase have particle sizes of 5-25 microns diameter. The composition may be prepared by blending together two high impact polystyrene compositions, one of which contains the dispersed elastomer phase having the smaller particles and the other of which contains the dispersed elastomer of larger particle size. In another embodiment, styrene is interpolymerized with two different elastomers to yield the two different particle size ranges in the dispersed phase. In addition styrene may be interpolymerized with a single elastomer under such conditions, e.g. of agitation as to yield the desired particle distribution in the elastomer-styrene interpolymer phase. Examples are given in which styrene is polymerized with polybutadiene and butadienestyrene block copolymer to yield a product in which the elastomer phase is of size 1 to 2 microns diameter and the product is blended with one obtained by polymerizing styrene with an SBR rubber to yield a product in which the elastomer phase is of size 15 to 20 microns. |
