The Dow Chemical Company

Buna Sow Leuna Olefinverbund Gmbh

Gerd Lohse

Otto J Berbee

Werner Zschoch

Juan Manuel Mezquita

Gerd Fritzsche

Heinz-J&uuml;rgen Kerrinnes

Harald Beer

J&uuml;rgen Schellenberg

The invention pertains to a method for producing ethylene homopolymerizates and ethylene copolymerizates exhibiting a lower mass density of up to 0.930 g/cm and a melt index ranging from 0.15 to 25 g/10 min (2.16 kg; 463 K). Said polymerizates exhibit an improved processing stability and improved availability in the installation at pressures greater than 1000 bar and at temperatures of up to 603 K. The polymerizates are produced in tubular reactors in the presence of radical-forming initiators, oxygen thereunder and chain transfer agents, of which at least one comprises an aldehydic structure. According to the inventive method, chemokinetic characteristics of the reactive feed materials (thermal half-life periods, concentrations, dosing quantities) are coupled with fluidically relevant characteristics of the tubular reactor (flow rate) while taking the target product quality (melt index, flow figure) into consideration. This coupling is carried out such that the interfering secondary reactions, especially polar-inductive substitution effects, which can lead to the formation and the enrichment of organic hydroperoxides are reduced to a minimum and, as a result, extraordinarily stable processing conditions can be obtained.

Method for producing ethylene homopolymerizates and ethylene copolymerizates of a lower mass density

The present invention relates to a process to produce polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst supported by an organic polymer material, for the production of moldings, such as through extrusion, injection molding, film blowing, sintering under pressure or ram extrusion. The catalyst according to the present invention contains a partially chloromethylated styrene divinyl benzene copolymer as the organic polymer material, a complex compound supported by it, which contains Mg, Al and Ti.

Production of polyethylene with a titanium amide catalyst

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Schkopau, Germany

Gerd Lohse