Abstract:
Procatalyst comprising an inorganic support, a chlorine compound carried on said support, a magnesium compound carried on said support, a titanium compound carried on said support, and a C 1 to C 6 alkyl substituted tetrahydrofuran as electron donor.
Abstract:
The disclosure relates to à process for polymerising olefins in multi stage polymerisation process configuration, the process comprising a) polymerising in a first polymerisation step first olefin monomer, optionally in the presence of at least one other alpha olefin comonomer, in the presence of a metallocene polymerisation catalyst so as to form a first polymer component (A); and b) transferring the first polymer component (A) into a separation unit to remove low molecule penetrants and to obtain separated solid polyolefin particles of the first polymer component (A*) and c) polymerising in in gas phase in a second polymerisation step second olefin monomer, optionally in the presence of at least one other alpha olefin comonomer in the presence of the separated solid polyolefin particles (A*) of step b), so as to form a second polymer component (B). The disclosure further relates to a method for improving performance of a metallocene polymerisation catalyst in a multi-stage olefin polymerisation, wherein a first polymer component (A) produced in a first polymerisation step is transferred into a separation unit to remove low molecule penetrants and to obtain separated solid polyolefin particles of the first polymer component (A*) prior to transferring the obtained separated solid polyolefin particles of the first polymer component (A*) to a further polymerisation step.
Abstract:
The disclosure relates to a process for polymerising olefins in multi stage polymerisation process configuration, comprising a) polymerising in a first polymerisation step first olefin monomer, optionally in the presence of at least one other alpha olefin monomer, in the presence of a polymerisation catalyst so as to form a first polymer component (A), and b) polymerising in a second polymerisation step in gas phase second olefin monomer, optionally in the presence of at least one other alpha olefin comonomer, in the presence of the first polymer component (A) of step a) and an induced swelling agent, so as to for a second polymer component (B), wherein the first polymer component (A) and the second polymer component (B) are produced at production rates meeting a predetermined target weight ratio of the second polymer component (B) to the first polymer component (A), the process comprising the steps of: i) determining a first weight ratio of the second polymer component (B) to the first polymer component (A) in the second polymerisation step, and ii) increasing the concentration of the induced swelling agent in the second polymerisation step if the determined first weight ratio is less than the predetermined target weight ratio, or iii) decreasing the concentration of the induced swelling agent in the second polymerisation step if the determined first weight ratio is greater than the predetermined target weight ratio, or iv) maintaining the concentration of the induced swelling agent in the second polymerisation step if the determined first weight ratio equals the predetermined target weight ratio. The disclosure further relates to use of an induced swelling agent in a gas phase polymerisation step for improving gas phase production split in a multi-stage olefin polymerisation process.
Abstract:
A process for the offline deactivation of at least one single site catalyst comprising contacting said catalyst with a deactivating agent selected from an aprotic low molecular weight carbonyl group containing organic compound or an aprotic low molecular weight orthoester or an aprotic low molecular weight acetal compound.
Abstract:
Ziegler-Natta catalyzed linear low density polyethylene which satisfies the following conditions: a) a density, according to ISO 1183, of from 900 to 925 kg/m 3 , b) a C 4 -C 10 -comonomer content, determined by Fourier transform infrared spectroscopy, of 1 to 16 wt% c) a weight average molecular weight Mw, determined by gel permeation chromatography, of at least 200 000, d) wherein the linear low density polyethylene comprises, by Crystallisation Analysis Fractionation (CRYSTAF) an amorphous fraction soluble at a temperature below 30°C of at most 10 wt% and a fraction crystallising between 60 to 75°C of at least 35 wt% and e) by temperature rising elution fractionation (TREF) analysis, at least 70 wt% of a crystallising polymer component having an elution temperature range from 60°C to 94°C and less than 10 wt% of a crystallising polymer component having an elution temperature range from 30°C to 60° and, f) by Gel Permeation chromatography using an Fourier transform infrared spectroscopy detector (GPC-FTIR), a substantially constant short chain branching profile across the molecular weight distribution (MWD) or g) by Gel Permeation chromatography coupled with Fourier transform infrared spectroscopy instruments (GPC-FTIR), a revers short chain branching profile across the molecular weight distribution (MWD), the linear low density polyethylene being produced in the presence of a special Ziegler- Natta procatalyst and a halogenated aluminium alkyl cocatalyst of the formula (IV) (C 1 -C 4 - alkyl) m -AI-X 3-m1 , wherein X is chlorine, bromine, iodine or fluorine and m is 1 or 2.
Abstract:
Ziegler-Natta catalyst composition capable of producing ethylene/alpha-olefins copolymers, particularly linear low density polyethylene; the composition having an improved stability of its behaviour during polymerization in respect to time. The Ziegler-Natta catalyst composition comprises: 1. Ziegler-Natta catalyst composition for the production of ethylene copolymers comprising A) a procatalyst, which procatalyst comprises a) an Al compound having the formula Al(alkyl) x Cl 3-x (I), where alkyl is an alkyl group with 1 to 12 and 0 ≤ x ≤ 3, b) a magnesium hydrocarbyloxy compound of formula Mg(OR 1 ) 2-n (R 2 ) n (II), wherein each R 1 and R 2 is independently a C 1-20 hydrocarbon residue which may optionally be substituted with halogen and 0 ≤ n y Ti(OR 3 ) 4-y (III), wherein R 3 is a C 2-20 hydrocarbon residue and y is 1, 2, 3 or 4, with compounds a), b) and c) being supported on a particulate inorganic carrier and B) a halogenated aluminium alkyl cocatalyst of the formula (IV) (C 1 -C 4 -alkyl) m -Al-X 3-m , wherein X is chlorine, bromine, iodine or fluorine and m is 1 or 2.
Abstract:
A racemic metallocene complex of formula (I') wherein each X is a sigma donor ligand; L is a carbon, silicon or germanium based divalent bridge in which one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each Het is independently a monocyclic or multicyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; each R1 is the same or different and is a linear C1-10 alkyl group, or linear C1-10 alkoxy, each n is 0 to 3; each R2 is the same or different and is a -Si(RaRbRc) group; Ra is C1-10 alkyl or phenyl group optionally substituted by 1 to 3 C1-6 alkyl groups; Rb is C1-10 alkyl or phenyl group optionally substituted by 1 to 3 C1-6 alkyl groups; Rc is a phenyl group optionally substituted by 1 to 3 C1-6 alkyl groups; and each p is 1 to 3.
Abstract:
A process for the preparation of a propylene homopolymer comprising polymerising propylene in the presence of a catalyst comprising: (i) a metallocene complex of a group (IV) metal said metallocene comprising at least two cyclopentadienyl type ligands; (ii) a boron cocatalyst; and (iii) an aluminoxane cocatalyst; said catalyst being in solid form, preferably in solid particulate form, and being free from an external carrier; preferably wherein the melting point of the propylene polymer is controlled by adjusting the amount of or nature of the boron cocatalyst.
Abstract:
A process for the polymerisation of at least one olefin comprising reacting said at least one olefin with a catalyst comprising: (i) a metallocene complex said metallocene comprising at least two cyclopentadienyl type ligands; (ii) a boron cocatalyst; and (iii) an aluminoxane cocatalyst; said catalyst being in solid form, preferably in solid particulate form, and being free from an external carrier.
Abstract:
The disclosure relates to a process for polymerising olefins in multi stage polymerisation process configuration, the process comprising a) polymerising in a first polymerisation step ethylene, optionally in the presence of at least one other alpha olefin comonomer, in the presence of a polymerisation catalyst so as to form a first polymer component (A); and b) polymerising in a second polymerisation step in gas phase a predetermined monomer mixture comprising ethylene and 1-hexene, optionally in the presence of at least one other alpha olefin comonomer, in the presence of the first polymer component (A) of step a), so as to form a second polymer component (B), wherein the multimodal polyethylene polymer produced by the present process comprises 1-hexene comonomer and at least one further C4-10-comonomer, and wherein the predetermined monomer mixture comprising ethylene and 1-hexene is fed into the second polymerisation step from the beginning of its start up. The disclosure further relates to use of 1-hexene in a gas phase olefin polymerisation step for improving performance of single-site polymerisation catalyst in multi-stage olefin copolymerisation process. The disclosure still further relates to a method for improving performance of single-site polymerisation catalyst in a multi-stage olefin polymerisation comprising feeding a predetermined monomer mixture comprising ethylene and 1-hexene into the gas phase polymerisation step from the beginning of its start up.