| 摘要 |
The impact resistance of rigid polymeric resins (e.g. PVC, SAN, PMMA, etc.,) is enhanced by the incorporation therein of an improved toughener. This toughener comprises three distinct phases: (a) a core of thermoplastic or thermoset resin having a Tg below room temperature, (b) a rubber-like layer overpolymerized on the core, and (c) a relatively hard polymer layer overpolymerized on the rubber layer. The utilization of a "soft" core, or seed, apparently enhances the efficiency of the toughener in the rigid polymer. In one of the preferred embodiments of this invention, the improved toughener comprises a seed derived from a partially corss-linked poly(n-butylacrylate), a rubber-like (or intermediate) layer derived from a monomer mixture containing n-butylacrylate and an addition monomer and an outer layer (or shell) derived from a monomer mixture containing styrene and methylmethacrylate. |
