Abstract: A process for the production of a propylene based polymer, the process comprising the following steps: (a) a first polymerization stage comprising homopolymerizing propylene or copolymerizing propylene and at least one alpha-olefin in the presence of an alpha-olefin polymerization catalyst whereby to produce a polypropylene component; (b) a second polymerization stage comprising copolymerizing ethylene and at least one alpha-olefin in the presence of an alpha-olefin polymerization catalyst whereby to produce an ethylene/alpha-olefin copolymer component; and (c) blending the polymer components produced in steps (a) and (b) whereby to produce a polymer blend, wherein the first and second polymerization stages are effected in separate polymerization reactors connected in parallel.

Abstract: A polymer composition suitable for rotomoulding comprising I) An ethylene homopolymer or copolymer with at least one other C3-10 &agr; olefin, having a melt flow rate of 0.5 to 30, a molecular weight distribution (Mw/Mn) of less than 4, an Mw of 50,000 to 110,000, a density of 0.940 g/cm3 to 0.970 g/cm3 and a melting point of 100 to 145° C.; or I) a propylene homopolymer or copolymer with at least one other C2-10 &agr; olefin, having a melt flow rate 0.5 to 30, a molecular weight distribution (Mw/Mn) of less than 4, an Mw of 150,000 to 300,000, and a melting point of 100 to 170° C.; and II) an ethylene homo or copolymer with at least one other C3-10 &agr;-olefin, having a melt flow rate of within 40% of the melt flow rate of component (I), a molecular weight distribution of (Mw/Mn) of less than 4, an Mw of within 30% of the Mw of component (I), a density of 0.880 g/cm3 to 0.940 g/cm3 said density being at least 0.

Abstract: A supported titanium catalyst system comprising a titanium catalyst bound via at least one heteroatom, a function-alised support, said heteroatom being connected to said support via an organic group.

Abstract: This invention relates to a process for the preparation of olefin polymers, preferably a multi-stage process, in which hydrogen is used to control the molecular weight of the olefin polymer produced in a continuous reactor, in particular a process wherein a metallocene or other single site catalyst is present in the polymerization reaction mixture, as well as to olefin polymers produced thereby.

Abstract: The invention provides a process for the production of a propylene based polymer, said process comprising the following steps: (a) a first polymerization stage comprising homopolymerizing propylene or copolymerizing propylene and at least one &agr;-olefin in the presence of an &agr;-olefin polymerization catalyst whereby to produce a polypropylene component; (b) a second polymerization stage comprising copolymerizing ethylene and at least one &agr;-olefin in the presence of an &agr;-olefin polymerization catalyst whereby to produce an ethylene/&agr;-olefin copolymer component; and (c) blending the polymer components produced in steps (a) and (b) whereby to produce a polymer blend, wherein said first and second polymerization stages are effected in separate polymerization reactors connected in parallel.

Abstract: The invention provides a supported chromium catalyst system comprising a chromium catalyst precursor bound via at least one heteroatom to a functionalised support, said heteroatom being connected to said support via an organic group.

Abstract: A process for olefin polymerization in a reaction vessel, said process comprising polymerizing at least one &agr;-olefin in a polymerization stage employing a catalyst feed comprising 1) a first catalyst composition having at least two active catalytic sites capable of producing a first set of polymer components; 2) a second catalyst composition having at least two active catalytic sites capable of giving essentially the same set of polymer components as produced by the catalyst in feed (1) under the same polymerization conditions but these components in a different ratio to those produced by the catalyst composition of feed (1); wherein the amounts of catalyst compositions (1 and 2) fed into the reaction vessel are independently controlled.

Abstract: Olefin polymers are prepared in a plurality of polymerization stages, optionally in a plurality of polymerization reactors, in the presence of hydrogen and an olefin polymerization multisite catalyst, preferably a dualsite catalyst, having at least catalytic sites A and B, site A capable of yielding polymers of different molecular weights and differing MFR2 or MFR21 depending on the concentration of hydrogen in the polymerization reactor and site B capable of yielding polymers of certain molecular weight and MFR2 or MFR21 depending on the concentration of hydrogen in the polymerization reactor where the ratio between MFR2 or MFR21 of polymers produced by site B at two different selected hydrogen concentrations is less than ten and the ratio between MFR2 or MFR21 of polymers produced by site A at the same hydrogen concentrations is more than 50.

Abstract: The invention relates to a process for the preparation of an olefin polymer wherein olefin polymerization is effected in a plurality of polymerization reaction stages in the presence of an olefin polymerization catalyst material, characterized in that said catalyst material comprises at least two different types of active polymerization sites.

Abstract: A polyethylene produced by the homopolymerisation of ethylene or copolymerisation of ethylene with &agr;-olefins in the presence of a catalyst, characterized in that the fraction of low molecular weight polymers having MW<5000 g/mole is lower than 12% by weight of the produced polymer, and that the produced polyethylene has a measured melt strength expressed by a haul-off (HO) value satisfying the expression: HO>K1·&eegr;0.05+K2, wherein K1 is 9.10−5 and K2 is 0.4.

Abstract: A process for the polymerization of ethylene and optionally &agr;-olefins to form ethylene homopolymer or copolymers having a broad molecular weight distribution, comprising polymerization of 100-80 wt. % of ethylene and 0-20 wt. % of comonomer in the presence of two independent, simultaneously present catalysts A and B, wherein catalyst A, deposited on an inorganic support, comprises chromium in a predominantly oxidant state of 2 and catalyst B comprises a bis-cyclopentadienyl chromium compound reacted with an inorganic support.