The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 2021
Filed:
Sep. 20, 2019
Chevron Phillips Chemical Company Lp, The Woodlands, TX (US);
Max P. McDaniel, Bartlesville, OK (US);
Kathy S. Clear, Bartlesville, OK (US);
William C. Ellis, Bartlesville, OK (US);
Deloris R. Gagan, Ramona, OK (US);
Ted H. Cymbaluk, Seabrook, TX (US);
Chevron Phillips Chemical Company LP, The Woodlands, TX (US);
Abstract
Processes for activating chromium polymerization catalysts, which can use lower maximum activation temperatures and shorter activation times than conventional activation methods, and provide polyethylenes with high melt indices, broader molecular weight distributions, and lower long chain branching content. The activation process can comprise heating a supported chromium catalyst in an inert atmosphere to a first temperature (T) for a first hold time (t), followed by allowing the chromium catalyst to attain a second temperature (T) in the inert atmosphere, then contacting the chromium catalyst with an oxidative atmosphere for a second hold time (t), in which Tcan be less than or equal to T. Additional activation treatments and conditioning steps are disclosed which can be used to enhance the melt index potential of Phillips (Cr/silica) catalysts.