This invention relates to polyolefin. More specifically, this invention relates to polyolefin that has small copolymer content, but exhibits excellent mechanical properties.

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.

The invention relates to a polypropylene composition comprising a propylene homopolymer or propylene-ethylene copolymer having an ethylene content of at most 1.0 wt % based on the propylene-ethylene copolymer, wherein the amount of propylene homopolymer or propylene-ethylene copolymer is at least 98 wt %, for example at least 98.5 wt %, preferably at least 99 wt %, more preferably at least 99.5, for example at least 99.75 wt % based on the polypropylene composition, wherein the polypropylene composition has a melt flow rate in the range of 0.70 to 2.4 dg/min as measured according to IS01 133 (2.16 kg/230° C.), an Mw/Mn in the range from 7.0 to 13.0, wherein Mw stands for the weight average molecular weight and Mn stands for the number average weight, an Mz/Mn is in the range from 20 to 50, wherein Mz stands for the z-average molecular weight and wherein Mw, Mn and Mz are measured according to ASTM D6474-12.

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900° C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900° C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

A metallocene complex of formula (I): each X is a sigma-ligand; in the group R.sub.2Si— at least one R is methyl or ethyl, and the other R is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, pentyl, hexyl, cyclohexyl and phenyl; each R.sup.1 independently is the same or can be different and are a CH.sub.2—R.sup.7 group, with R.sup.7 being H or linear or branched C.sub.1-6-alkyl group, C.sub.3-8 cycloalkyl group, or C.sub.6-10 aryl group; each R.sup.2 is independently a —CH═, —CY═, —CH.sub.2—, —CHY— or —CY.sub.2— group, wherein Y is a C.sub.1-6 hydrocarbyl group and where n is 2-6; each R.sup.3 and R.sup.4 are independently the same or can be different and are hydrogen, a linear or branched C.sub.1-6-alkyl group, a C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group, C.sub.6-20 aryl group, or an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group; R.sup.5 is a linear or branched C.sub.1-6-alkyl group, C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group or C.sub.6-20-aryl group; and R.sup.6 is a C(R.sup.8).sub.3 group, with R.sup.8 being a linear or branched C.sub.1-6 alkyl group; (A) wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is not hydrogen, and wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is hydrogen; or (B) wherein one R.sup.3 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4 position of each phenyl group and the two other R.sup.3 groups are tert-butyl groups; and/or (C) wherein one R.sup.4 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4-position of the phenyl ring and the two other R.sup.4 groups are tert-butyl groups.

##STR00001##

A metallocene complex of formula (I): each X is a sigma-ligand; in the group R.sub.2Si— at least one R is methyl or ethyl, and the other R is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, pentyl, hexyl, cyclohexyl and phenyl; each R.sup.1 independently is the same or can be different and are a CH.sub.2—R.sup.7 group, with R.sup.7 being H or linear or branched C.sub.1-6-alkyl group, C.sub.3-8 cycloalkyl group, or C.sub.6-10 aryl group; each R.sup.2 is independently a —CH═, —CY═, —CH.sub.2—, —CHY— or —CY.sub.2— group, wherein Y is a C.sub.1-6 hydrocarbyl group and where n is 2-6; each R.sup.3 and R.sup.4 are independently the same or can be different and are hydrogen, a linear or branched C.sub.1-6-alkyl group, a C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group, C.sub.6-20 aryl group, or an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group; R.sup.5 is a linear or branched C.sub.1-6-alkyl group, C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group or C.sub.6-20-aryl group; and R.sup.6 is a C(R.sup.8).sub.3 group, with R.sup.8 being a linear or branched C.sub.1-6 alkyl group; (A) wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is not hydrogen, and wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is hydrogen; or (B) wherein one R.sup.3 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4 position of each phenyl group and the two other R.sup.3 groups are tert-butyl groups; and/or (C) wherein one R.sup.4 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4-position of the phenyl ring and the two other R.sup.4 groups are tert-butyl groups.

##STR00001##

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) η.sub.0.02 from 80,000 to 300,000 Pa.Math.s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

The present invention relates to Ziegler-Natta catalyst components for olefin polymerization employing specific carbonate compounds as an element of solid catalyst composition in conjunction with at least one or more internal donor compounds, for producing polyolefins, particularly polypropylene and ethylene-propylene block co-polymer, which exhibits substantially high rubber content with higher stereo-regularity and hydrogen response.