Patent ID: 6410659
Filing Date: 2002-06-25
Classification: C08F,Y10S

Abstract:
A process for preparing bimodal molecular weight distribution copolymers of ethylene with alpha-olefins having from 3 to 20 carbon atoms, said copolymers having:(a) a comonomer distribution wherein the comonomer level at the mid-position of the low molecular weight component is less than or equal to 1.6 times the level at the mid-position of the high molecular weight component, and (b) a total average comonomer content in the range from 0.5 to 20 short chain branches (SCB)/1000 carbon atoms wherein said process is carried out in the presence of a supported multisite catalyst, wherein all the catalyst components are supported on a single support, said catalyst comprising a Ziegler catalyst component and a metallocene component having any of the formulae:(C5R5)(C5R15)MY2â€ƒâ€ƒ(I) (C5R2H3)(C5R12H3)MY2â€ƒâ€ƒ(II) (C5R4)Z(C5R14)MY2;â€ƒâ€ƒ(III) or(C5RmH5âˆ’m)(C5R1nR5âˆ’n)MY2â€ƒâ€ƒ(IV) wherein:C5R5 and C5R15 represent a cyclopentadienyl ligand, R and R1 are alkyl, aryl, alkylaryl, alkenyl, or haloalkyl groups and may be the same or different, Z is a bridging group selected from the group consisting of CX2, SiX2, and GeX2, X is hydrogen or a group as defined by R and R1, M is Zr, Ti, or Hf, Y is a univalent anionic ligand and wherein in Formula (II) at least one of R and R1 has &gE;three carbon atoms, and in Formula (IV) m is 3 or 4 and n is 5 or less.