Borealis Technology Oy

Norner Verdandi As

Evonik Degussa Gmbh

Indian Oil Corporation Limited

Evonik Oxeno Gmbh

Norner As

Jarmo Lindroos

Solveig Johansson

Thomas Garoff

Tore Dreng

Päivi Waldvogel

Michael Grass

Peter Denifl

Auli Nummila-Pakarinen

Ole Jan Myhre

Stefan Buchholz

Kari Pesonen

Ted M Pettijohn

P&auml;ivi Waldvogel

Gerhard Ellermann

Morten Lundquist

Timo V Laine

Gurpreet Singh Kapur

Ravinder Kumar Malhotra

Naresh Kumar

Gurmeet Singh

Sukhdeep Kaur

Mats Bäckman

Arild Follestad

Siw Bodil Fredriksen

Shashi Kant

Biswajit Basu

Paivi Waldvogel

Marja Ora

Arja Lehtinen

Jussi Laurell

Pal Christian Bentzrod

Elisabeth Ribarits

Anne Britt Bjåland

Mats B&auml;ckman

Eeva-Leena Heino

Teija Sihvonen

Jari Aaril&auml;

Pål Christian Bentzrød

Svein Nenseth

Solveig Johansonn

Peter Mann

Minna Stahlhammar

Young Ko Soo

Ted Pettijohn

Pal Bentzrod

Anne Brit Bjaland

The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerising ethylene and optionally an &#x3b1;-olefin comonomer in a first polymerisation stage to produce a first ethylene polymer; and (ii) polymerising ethylene and optionally an &#x3b1;-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerisation stage, wherein the first and second polymerisation stages are carried out in the presence of an unsupported metallocene catalyst and each polymerisation stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed. The present invention also provides a multimodal polyethylene, a process for preparing a pipe comprising preparing a multimodal polyethylene and extruding the multimodal polyethylene to produce a pipe, and a pipe obtained by such a process.

Polyethylene for pipes

The present invention provides a process for the preparation of a multimodal polyethylene comprising: (i) polymerizing ethylene and optionally an &#x3b1;-olefin comonomer in a first polymerization stage to produce a first ethylene polymer; and (ii) polymerizing ethylene and optionally an &#x3b1;-olefin comonomer, in the presence of said first ethylene polymer, in a second polymerization stage, wherein the first and second polymerization stages are carried out in the presence of an unsupported metallocene catalyst and each polymerization stage produces at least 5% wt of the multimodal polyethylene, and the multimodal polyethylene has a multimodal molecular weight distribution, a molecular weight of at least 50,000 g/mol and a bulk density of at least 250 g/dm, and wherein a solution of the unsupported metallocene catalyst in a solvent is employed. The present invention also provides a multimodal polyethylene, a process for preparing a pipe comprising preparing a multimodal polyethylene and extruding the multimodal recycle polyethylene to produce a pipe, and a pipe obtained by such a process.

The present invention provides a process for preparation of a solid titanium catalyst component for use as pro-catalyst for a Ziegler-Natta catalyst system. The solid titanium catalyst component comprises a combination of 15 to 20 wt % of a magnesium moiety, 1.0 to 6.0 wt % of a titanium moiety and 5.0 to 20 wt % of an internal donor, said solid titanium catalyst component has an average particle size in the range of 1 to 100 &#x3bc;m, characterized by a three point particle size distribution of D10 in the range of 1 to 10 &#x3bc;m; D50 in the range of to 25 &#x3bc;m and D90 in the range of 15 to 50 &#x3bc;m. The present invention also provides a 15 Ziegler-Natta catalyst system comprising the solid titanium catalyst component and the method of polymerizing and/or copolymerizing olefins by using the Ziegler-Natta catalyst system.

Catalyst for polymerization of olefins and process thereof

A film containing an interpolymer of ethylene and a 3-substituted Calkene is prepared using a catalyst system comprising a Ziegler Natta or chromium oxide catalyst.

Polyethylene/3-substituted alkene film made with Ziegler-Natta or chromium oxide catalyst

An alkene interpolymer is prepared by polymerizing at least one 3-substituted Calkene and at least one Calkene in a gas phase polymerization using a polymerization catalyst system.

Polyolefin gas phase polymerization with 3-substituted C4-10-alkene

The present invention relates to a process for the production of catalysts, particularly of Ziegler-Natta type of catalysts for olefin polymerisation, to the catalysts as such, and to their use in polymerising olefins.

Method for the preparation of olefin polymerization catalysts

The invention provides a process for producing an olefin polymerization catalyst comprising a catalyst component formed by contacting at least (a) a compound of Group 1 to 3 of the Periodic Table (IUPAC) with (b) a transition metal compound of Group 4 to 10 of the Periodic Table (IUPAC) or a compound of an actinide or lanthanide, in the form of solid catalyst particles, said process comprising: (1) preparing a solution from said compounds; (2) dispersing said solution to a solvent immiscible therewith and inert in relation to said compounds, to obtain an emulsion in which said solution forms the dispersed phase; and (3) solidifying the catalyst component in the dispersed droplets.

A process for the preparation of an olefin polymerisation catalyst comprising: a) reacting an aluminoxane and a Lewis base in an optionally halogenated hydrocarbon solvent to form a particulate suspension; b) reacting said suspension with a metallocene complex in an optionally halogenated hydrocarbon solvent; and optionally c) isolating the olefin polymerisation catalyst.

Process to prepare a particulated metallocene catalyst with a modified aluminoxane and use in polymerization of olefins

A process for polymerizing olefins using a high activity catalyst. The catalyst utilize in the present process has a good balance in activity and can be used to carry out ethylene polymerization at high and low melt flow rates to produce low gel or gel free product.

Olefin polymerization catalyst component, its preparation and use

High density polyethylene compositions, a process for the production thereof and films prepared

The present invention concerns a process for producing homogeneous polyethylene materials and processes for making high density, medium density and low density films therefrom. The process involves producing a polyethylene composition in a multistage reaction sequence of successive polymerization stages in the presence of an ethylene-polymerizing catalyst system. According to the invention, the process is carried out using an unsupported catalyst having magnesium and titanium as active constituents, in at least one loop polymerization stage and at least one gas phase polymerization stage and, operated with different amounts of hydrogen and comonomers to produce a high molecular weight portion in one of the polymerization stages and a low molecular weight portion in another so as to provide a polyethylene composition with the low molecular weight part having a MFR of 250 g/10 min or more. With this process it is possible to obtain homogeneous bimodal polyethylene material.

Process for producing a homogeneous polyethylene material in the presence of a catalyst

A multimodal polymer composition for pipes is disclosed as well as a pipes made thereof. The polymer is a multimodal polyethylene with a density of 0.930-0.965 g/cm , and a viscosity at a shear stress of 747 Pa of at least 650 Pa.s, said multimodal polyethylene comprising a low molecular weight (LMW) ethylene homopolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction, said HMW fraction having a weight ratio of the LMW fraction to the HMW fraction of (35-55):(65-45). Preferably, the multimodal polyethylene has a viscosity at a shear stress of 2.7 kPa of 260-450 kPa.s; and a shear thinning index (SHI) defined as the ratio of the viscosities at shear stresses of 2.7 and 210 kPa, respectively, of SHI &equals;50-150, and a storage modulus (G&prime;) at a loss modulus (G&Prime;) of 5 kPa, of G&prime; &gE;3000 Pa. The pipe is made of the multimodal polymer composition and withstands a stress of 8.0 MPa gauge during 50 years at 20&deg; C. (MRS8.0). Preferably, the pipe has a rapid crack propagation (RCP) S4-value, determined according to ISO 13477:1997(E), of &minus;5&deg; C. or lower and a slow crack propagation resistance, determined according to ISO 13479:1997, of at least 500 hrs at 4.6 MPa/80&deg; C. The polymer composition affords good non-sagging properties to pipe made thereof.

Polymer composition for pipes

Growing community of inventors

Stathelle, Norway

Jarmo Lindroos