| 摘要 |
There is disclosed a monovinylidene aromatic polymer resin having a specific rubber particle size distribution that provides surprisingly improved combinations of product properties, such as gloss, impact resistance and tensile strength. Such resin has a first group of smaller particles having a volume average particle diameter of from 0.2 to 0.6 micrometers and a second group of larger particles having a volume average particle diameter of from 2.5 to 5 micrometers. In these resins it is further necessary in this specific rubber particle size distribution, based on 100 parts by weight rubber or rubber equivalent, that (a) particles constituting 20 to 60 parts by weight of the rubber have diameters of from 0.1 to 0.8 micrometers, (b) particles constituting 60 to 20 parts by weight of the rubber have diameters of from 2 to 6 micrometers, and (c) that there be a specific amount of intermediate size particles constituting from 10 to 30 parts by weight of the rubber -36- and having diameters between 0.8 and 2 micrometers. Also disclosed is a process for preparing such resins in a simplified production process wherein the rubber which is used has distinct high and low molecular weight components, the high molecular weight component having a weight average molecular weight at least twoand one half times greater than the weight average molecular weight of the low molecular weight component.
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