Abstract: Modified polypropylene impact copolymer compositions containing a base polypropylene impact copolymer and a certain modifier have good impact strength, toughness and resistance to stress whitening. The modifier includes a hydrogenated block copolymer having at least one polymeric block of predominantly polymerized monoalkenyl aromatic hydrocarbon monomer units and at least one polymeric block of predominantly polymerized conjugated diolefin monomer units. The modifier may additionally contain a polyethyleneic ethylene-.alpha.-olefin copolymer.

Abstract: Polypropylene impact copolymer compositions are provided which contain a homopolymer phase of predominantly homopolymeric polypropylene, a copolymer phase of copolymerized ethylene and propylene, and a nucleating agent. The inventive compositions have a rubber content (Fc) in the range of 25 to 45% by weight, a crystallization temperature in the range of 122.degree. to 132.degree. C., a melt flow in the range of about 7 to about 60 dg/min, and a ratio of the intrinsic viscosity of the copolymer phase to the intrinsic viscosity of the homopolymer phase of 1.4 to about 1.9. The polypropylene impact copolymer compositions may be used to form cast films which preferably are soft, quiet, and suitable for use in products to be used next to the skin, such as diapers, adult incontinence pads and feminine hygiene products.

Abstract: A process is provided for preparing a shape-shifted catalyst component comprising (1) contacting a dihydrocarbyloxide magnesium compound with carbon dioxide in the presence of a slurrying agent to form a slurry of a carboxylated dihydrocarbyloxide magnesium compound; (2) adding a filler to the slurry either before or after the carboxylation of step (1); (3) spray drying the slurry of step (2) to evaporate the slurrying agent and to produce solid particles of the carboxylated dihydrocarbyloxide magnesium compound incorporating the filler; and, optionally, (4) heating the solid particles to remove carbon dioxide to produce a shape-shifted dihydrocarbyloxide magnesium compound component. A catalyst system using the component and a polymerization process employing the catalyst system are also provided.

Abstract: A process is provided for preparing a shape-shifted catalyst component comprising (1) contacting a dihydrocarbyloxide magnesium compound with carbon dioxide in the presence of a slurrying agent to form a slurry of a carboxylated dihydrocarbyloxide magnesium compound; (2) adding a filler to the slurry either before or after the carboxylation of step (1); (3) spray drying the slurry of step (2) to evaporate the slurrying agent and to produce solid particles of the carboxylated dihydrocarbyloxide magnesium compound incorporating the filler; and, optionally, (4) heating the solid particles to remove carbon dioxide to produce a shape-shifted dihydrocarbyloxide magnesium compound component. A catalyst system using the component and a polymerization process employing the catalyst system are also provided.