Patent · US Expired

Ethylene polymerization catalyst and method

US4173548A · kind A · utility

22Cited by
8References
26Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 12, 1978
Grant dateNov 6, 1979
Priority date
Expiry dateJun 12, 1998

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S502/506
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

A highly active catalyst for polymerizing ethylene to polyethylene and copolymers of ethylene with alpha-olefins having a narrow molecular weight distribution, a method of making the catalyst and a method of polymerizing in which the catalyst is prepared by forming a mixture of a porous support of silica, alumina, zirconia, thoria or mixtures and a chromium compound and an alkyl ester of boron containing 1-7 carbon atoms in the alkyl group or a halide of boron capable of reacting with the chromium compound and activating this mixture at an elevated temperature in a fluidized bed with a substantially dry reducing gas followed by fluidizing with an oxidizing gas at an elevated temperature.

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