Transparent elastomeric thermoplastic polyolefin compositions

摘要

An elastomeric thermoplastic polyolefin composition comprising (I) a crystalline propylene polymer containing at least 80% by weight of a fraction insoluble in xylene at room temperature, the intrinsic viscosity being higher than 0.5 dL/g; (II) an atactic or amorphous propylene polymer having intrinsic viscosity higher than 0.5 dL/g; and (III) an elastomeric olefin polymer consisting of copolymers of ethylene with a comonomer selected from a C3-C8 alpha -olefin, the intrinsic viscosity ranging from 1 to 4 dL/g. In said polyolefin composition the density of the elastomeric olefin polymer (deOP) satisfies the following relation: deOP+/-0.005=ädcPP x ÄwcPP/(wcPP + waPP)Ü ü + ädaPP x ÄwaPP/(wcPP+ waPP)Üü wherein wcPP and waPP are the weight percentage content of components (I) and (II) respectively and dcPP and daPP are the density at room temperature of components (I) and (II) respectively.