Process for producing a chemically blended propylene polymer composition and the composition produced by said process

Claim 1

A process for producing a chemically blended propylene polymer composition having an ethylene content ranging from 3 to 40% by weight and being greater than the weight of the rubbery propylene copolymer formed in stage (II) below, which comprises the following stages (I) and (II): (I) a first stage of polymerizing propylene containing 0 to 5 mole% of another olefin, at a temperature of about 20° C. to about 200° C. and a pressure of atmospheric pressure to about 100 kg/cm 2 , in the presence of a catalyst composed of (A) a solid titanium catalyst component consisting essentially of titanium, magnesium, halogen, and an electron donor, the amount of (A) being from about 0.0005 to about 0.5 millimole, as the titanium atom, per liter of the polymerization volume, (B) an organoaluminum compound, and (C) an organic silicon compound having an Si--O--C bond in which the atomic ratio of Al in the component (B) to Ti in the component (A) is from about 1 to about 2000 and the mole ratio of the component (C) to Ti in the component (A) is from about 0.05 to about 200, to thereby form a crystalline propylene polymer or copolymer; and (II) a second stage of polymerizing propylene and ethylene, or propylene, ethylene and another olefin in the presence of the reaction product of the first stage and the same catalyst as used in the first stage, at a temperature of about 20° C. to about 200° C. and a pressure of atmospheric pressure to about 100 kg/cm 2 , to form a rubbery propylene copolymer and a crystalline ethylene polymer or copolymer.