Bp Chemicals Limited

Christopher James Frye

Choon Kooi Chai

Teresa Plumley Karjala

David R Wilson

Deepak R Parikh

Lee Spencer

Ian M Munro

Philip Howard

William R Van Volkenburgh

Kevin P Peil

Larry Duane Cady

Brian Leslie Turtle

David George Gilbert

Peter J Maddox

S Roy Partington

Peter S Williams

Frederic Alarcon

J Mark Winter

Novel stretch and blown films are prepared based on copolymers of ethylene and alpha-olefins having (a) a density in the range 0.900 to 0.940 (b) an apparent Mw/Mn of 2&#x2013;3.4 (c) I/Ifrom 16 to 24 (d) activation energy of flow from 28 to 45 kJ/mol (e) a ratio Ea(HMW)/Ea(LMW)&#x3e;1.1, and (f) a ratio g'(HMW)/g&#x2032;(LMW) from 0.85 to 0.95. The films exhibit an excellent combination of strength and processability and are particularly suitable for use as either stretch films or blown films for use as heavy duty sacks. The preferred films show a dart impact of &#x3e;1100 g and MD elongations of &#x3e;500%.

Polyethylene films

Novel copolymers comprise ethylene and alpha olefins having from 3 to 10 carbon atoms and which have The copolymers are particularly useful in film applications showing an excellent balance of processing, optical and mechanical properties. The novel polymers may suitably be prepared in the gas phase in the presence of metallocene complexes.

Copolymers and films thereof

Low density copolymers of ethylene and alpha-olefins

The invention relates to a polyolefin copolymer composition produced with a catalyst having a metallocene, complex in a single reactor for the polymer of an &agr;-olefin monomer with one or more olefin comonomers, and a molecule weight maximum which occurs in that 50 percent by weight of the composition which has the highest weight percent comonomer content. Preferably, the composition has a comonomer partitioning fact C which is equal to or greater than 1.10 or molecule weight partitioning fact M which is equal to or greater than 1.15. Preferred composition also have at least 0.01 long chain branches per 1000 carbon atoms along the polymer backbone. These compositions with reverse molecular engineering have. superior properties and are easily processable due to the simultaneous presence of the association of high molecular weight with high comonomer content and of long chain branching.

Polyolefin composition with molecular weight maximum occurring in that part of the composition that has the highest comonomer content

Growing community of inventors

St Julien-Martigues, France

Christopher James Frye