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US 4,397,769 AGranted
Olefin polymerization catalyst
AssigneePhillips Petroleum Company
InventorsMax P. McDaniel, John A. Sanbrano, Marvin M. Johnson
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AssigneePhillips Petroleum Company
InventorsMax P. McDaniel, John A. Sanbrano, Marvin M. Johnson
Estimating the term…
A supported chromium oxide polymerization catalyst is prepared by a process which includes the steps of heating silica-supported chromium oxide or a substance oxidizable to chromium oxide in a nonoxidizing atmosphere in the presence of formaldehyde or a compound thermally decomposable to formaldehyde, and then heating the thus-treated catalyst in an oxygen-containing atmosphere. The temperatures of the respective heating steps can vary depending upon the properties desired in the polymer to be produced with the invention catalyst; however, the invention catalyst preparation method enables the production of a catalyst having a high melt index potential at relatively low treatment temperatures, e.g. no higher than about 600.degree. C.
A process for preparing a supported chromium oxide polymerization catalyst comprising the steps of
A process for activating a chromium oxide polymerization catalyst comprising the steps of
Dependencies are inferred from the claim text.