| abstract |
Amorphous propylene/1-butene and ethylene/propylene copolymers having increased tensile properties produced by the process comprising: reacting propylene and 1-butene monomers or ethylene and propylene monomers in the presence of a catalyst system comprising: (a) a solid supported catalyst component is prepared by the method comprising: (i) co-comminuting magnesium halide support base and aluminum trihalide in a molar ratio from about 8:0.5 to about 8:3 in the absence of added electron donor; and (ii) then co-comminuting the product of step (i) in the absence of added electron donor with sufficient titanium tetrahalide to provide a molar ratio of magnesium halide to titanium tetrahalide from about 8:0.1 to about 8:1.0; (b) a trialkylaluminum co-catalyst, having from 1 to 9 carbon atoms in each alkyl group in an amount such that the Al/Ti ratio is between about 50:1 and about 500:1; and (c) an alkoxy silane component of the formula RnSi(OR')4-n where n=1-3, R=aryl or alkyl and R'=C1-3 alkyl. |