Union Carbide Chemicals & Plastics Technology Corporation

Michael William Tilston

Thomas Edward Spriggs

Burkhard Eric Wagner

Mark Bradley Davis

George E Ealer

Arakalgud V Ramamurthy

Paul T Daniell

Sandra A Kupperblatt

James Daniel Madden

Vinayak Maheshwari

Bimodal resin products are produced in a single reactor by using two bicomponent catalyst compositions, each having a high molecular weight and a low molecular weight component, in different ratios. The HMW/LMW split of the final resin product is controlled accurately by controlling the ratio of the feed of the two bicomponent catalyst compositions. Bimodal or polymodal effects are also achieved for properties or characteristics other than molecular weight. More complex results can be achieved with more than two components. The invention is applicable to a wide variety of polymer products, particularly polyolefins and polyethylene.

Control of resin split in single-reactor manufacture of bimodal polyolefins

A process comprising contacting ethylene and at least one alpha-olefin comonomer having with a transition metal based catalyst system in two fluidized bed reactors connected in series, in the gas phase, under polymerization conditions, with the proviso that a hydrocarbyl aluminum cocatalyst is introduced into the first reactor and a different hydrocarbyl aluminum cocatalyst or no cocatalyst is introduced into the second reactor.

Staged reactor process

A blend comprising a mixture of two ethylene/alpha-olefin copolymers, said blend having a flow index in the range of about 5 to about 50 grams per 10 minutes; a melt flow ratio in the range of about 10 to about 50; a density in the range of 0.900 to 0.940 gram per cubic centimeter; a molecular weight in the range of about 98,000 to about 190,000; and an Mw/Mn ratio in the range of about 2 to about 8, said blend having been prepared by mixing first and second copolymers having about equal molecular weights, each copolymer being a copolymer of ethylene and an alpha-olefin having 3 to 8 carbon atoms, the first copolymer having a flow index in the range of about 5 to about 75 grams per 10 minutes; a melt flow ratio in the range of about 10 to about 50; a density in the range of 0.860 to 0.930 gram per cubic centimeter; a molecular weight in the range of about 87,000 to about 190,000; and an Mw/Mn ratio in the range of about 2 to about 4 and the second copolymer having a flow index in the range of about 5 to about 75 grams per 10 minutes; a melt flow ration in the range of about 10 to about 50; a density in the range of 0.935 to 0.970 gram per cubic centimeter; a molecular weight in the range of about 87,000 to about 190,000; and an Mw/Mn ratio in the range of about 2 to about 4, the weight ratio of the first copolymer to the second copolymer being in the range of about 70:30 to about 30:70.

High strength polyethylene film

A process comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a transition metal based catalyst system in two fluidized bed reactors connected in series, in the gas phase, under polymerization conditions, with the provisos that: (a) the first reactor is operated at a temperature at or above the dew point of the mixture of monomers, but no higher than about 5 degrees C. above said dew point; (b) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series; (c) other than the active catalyst referred to in proviso (b), no additional catalyst is introduced into the second reactor; (d) in the reactor in which a low melt index copolymer is made:

High activity staged reactor process

A gas phase process for the production of a polyethylene blend comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a magnesium/titanium based catalyst system including an activator and a cocatalyst in each of two fluidized bed reactors connected in series, under polymerization conditions, with the provisos that:

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St. Albans, WV, United States of America

Michael William Tilston