| abstract |
A pre-polymerized catalyst component for the polymerization of olefins, characterized by comprising a non-stereospecific solid catalyst component, comprising Ti, Mg and a halogen and an amount of a (co)polymer of an alpha-olefin CH 2 =CHR1, wherein R is a C 1 C 12 hydrocarbon group, ranging from 0.1 up to 500g per g of said solid catalyst component, said (co)polymer being characterized by an isotacticity, expressed in terms isotactic pentads, of higher than 60% molar and by an intrinsic viscosity, measured in tetraline at 135°C, of at least 1.0 dL/g. |