A polymerization process includes contacting an olefin or a mixture of the olefin and one or more copolymerizable comonomers under polymerization conditions with a catalyst composition and forming a polymer with a total ash content of less than 15 ppm. The catalyst composition includes one or more polymerization catalysts; and a mixed external electron donor comprising a selectivity control agent comprising at least one silicon-containing compound containing at least one C1-C10 alkoxy group bonded to a silicon atom.

Disclosed is a polypropylene with an MFR of at least 20 g/10 min comprising a homopolypropylene and within a range from 2 wt % to 20 wt % of a propylene-α-olefin copolymer by weight of the polypropylene, where the homopolypropylene has a MFR within a range from 30 g/10 min to 200 g/10 min, where the propylene-α-olefin copolymer comprises within a range from 30 wt % to 50 wt % α-olefin derived units by weight of the propylene-α-olefin copolymer, and has an IV within a range from 4 to 9 dL/g. The polypropylene may be obtained by combining a Ziegler-Natta catalyst having two transition metals with propylene in reactors in series to produce the homopolypropylene followed by a gas phase reactor to produce a propylene-α-olefin copolymer blended with the homopolypropylene.

Disclosed is a polypropylene with an MFR of at least 20 g/10 min comprising a homopolypropylene and within a range from 2 wt % to 20 wt % of a propylene-α-olefin copolymer by weight of the polypropylene, where the homopolypropylene has a MFR within a range from 30 g/10 min to 200 g/10 min, where the propylene-α-olefin copolymer comprises within a range from 30 wt % to 50 wt % α-olefin derived units by weight of the propylene-α-olefin copolymer, and has an IV within a range from 4 to 9 dL/g. The polypropylene may be obtained by combining a Ziegler-Natta catalyst having two transition metals with propylene in reactors in series to produce the homopolypropylene followed by a gas phase reactor to produce a propylene-α-olefin copolymer blended with the homopolypropylene.

Provided is a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.

Provided is a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.

Cyclic organosilicon compounds having a structure represented by the general formula ##STR00001##
and a method for using thereof as a component of catalysts for producing propylene polymer having a very high melt-flowability are disclosed. The cyclic organosilicon compounds are employed as external electron donors in Ziegler-Natta catalyst systems to dramatically improve the hydrogen response, and therefore the catalyst systems can be used to prepare polymer having high melt-flowability and high isotacticity at high yield.

Cyclic organosilicon compounds having a structure represented by the general formula ##STR00001##
and a method for using thereof as a component of catalysts for producing propylene polymer having a very high melt-flowability are disclosed. The cyclic organosilicon compounds are employed as external electron donors in Ziegler-Natta catalyst systems to dramatically improve the hydrogen response, and therefore the catalyst systems can be used to prepare polymer having high melt-flowability and high isotacticity at high yield.

A propylene/1-hexene copolymer having i) the content of 1-hexene derived units, measured by C.sup.13-NMR, ranging from 1.5 wt % to 2.5 wt % and the content of propylene derived units ranging from 97.5 to 98.5 wt. %; ii) a melting temperature, measured by DSC, ranging from 148 to 153° C.; iii) an amount of fraction insoluble in xylene at 25° C. higher than 97.0%; and iv) a melt flow rate (MFR), measured according to ISO 1133, 230° C., 2.16 kg, ranging from 35 to 65 g/10 min.

A propylene/1-hexene copolymer having i) the content of 1-hexene derived units, measured by C.sup.13-NMR, ranging from 1.5 wt % to 2.5 wt % and the content of propylene derived units ranging from 97.5 to 98.5 wt. %; ii) a melting temperature, measured by DSC, ranging from 148 to 153° C.; iii) an amount of fraction insoluble in xylene at 25° C. higher than 97.0%; and iv) a melt flow rate (MFR), measured according to ISO 1133, 230° C., 2.16 kg, ranging from 35 to 65 g/10 min.

Provided is a production method that can produce an olefin resin composition having excellent long-term stability and providing a sufficient stabilization effect to the olefin resin composition. This production method is a method of producing an olefin resin composition that contains a polyolefin resin polymerized with, an addition of a mixture of a phenolic antioxidant represented by the following Formula (1) and a phosphite compound represented by the following Formula (2) or (3), and an organoaluminum compound or a mixed solvent of an organoaluminum compound and an organic solvent, to a catalyst system or a polymerization system before or during the polymerization of the olefin monomer.