Patent ID: 8011913

Claim:
A method of melt blending comprising: (a) providing a screw-type extruder possessing addition points from a zero point to a 100 point the length of the extruder, where the extruder has an L/D within the range of from 50 to 35 and an output within the range of from 60 to 80 kg/hr; (b) adding at least one thermoplastic and ethylene-propylene-diene rubber at the zero to 10 point of the extruder, where the thermoplastic is selected from polypropylene comprising from 0 to 20 wt % of C 2 or C 4 to C 10 α-olefins, by weight of the polypropylene; (c) melt blending the thermoplastic and the rubber at a temperature of from 180° C. to 290° C. and at a shear rate in the range of 2,000 to 8,000 s −1; (d) adding at least one silicone hydride at the 5 to 30 point of the extruder; (e) adding at least one metal catalyst at the 20 to 60 point of the extruder, where the silicone hydride has the formula: wherein H is hydrogen, and each R′ is independently selected from C 1 to C 3 alkyl groups, R″ is selected from C 1 to C 3 alkyl groups, n is 0 or 7, m is 17 with the proviso that the metal catalyst is added at least 5 points farther down the extruder than the silicone hydride; and (f) isolating a thermoplastic vulcanizate from the 90 to 100 point of the extruder.