Patent · US Expired

Ethylene polymerization

US6632896B1 · kind B1 · utility

5Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 29, 1999
Grant dateOct 14, 2003
Priority date
Expiry dateNov 29, 2019

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08F2410/04
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

Ths invention provides a process for the preparation of a polyethylene, in particular an HDPE suitable for blow moulding of HIC, which comprises polymerizing ethylene and, optionally an ethylenically unsaturated comonomer copolymerizable therewith, in the presence of a catalyst comprising a first silica-supported chromium catalyst having a pore volume of at least 2 mL/g, a surface area of at least 350 m2/g and a chromium content of 0.1 to 1.0% by weight and a second silica-supported chromium catalyst having a pore volume of at least 2 mL/g, a surface area of at least 450 m2/g and a chromium content of 0.1 to 1.0% by weight, wherein the silica support of said first catalyst also comprises alumina and the silica support of said second catalyst also comprises titanium, and preferably a co-catalyst.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.