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US 10,246,528 B2Granted
Chromium (III) catalyst systems with activator-supports
AssigneeChevron Phillips Chemical Company LP
InventorsMax P. McDaniel, Mark L. Hlavinka, Kathy S. Collins
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Abstract
Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.
Claims24
An olefin polymerization process, the process comprising:
- (i) combining a chromium (III) compound with an activator-support comprising a solid oxide treated with an electron-withdrawing anion to form a mixture;
- (ii) subjecting the mixture to a non-oxidizing atmosphere at a peak temperature to produce a supported chromium catalyst;
- and
- (iii) contacting the supported chromium catalyst and a co-catalyst with ethylene and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an ethylene polymer, wherein a molar ratio of co-catalyst:chromium is in a range from about 50:1 to about 500:1;
- and
- wherein the ethylene polymer has a melt index in a range from 0 to about 0.5 g/10 min, and a Mw in a range from about 400,000 to about 900,000 g/mol.
3 more elements
An olefin polymerization process, the process comprising:
- (i) combining a chromium (III) compound with an activator-support comprising a solid oxide treated with an electron-withdrawing anion to form a mixture;
- (ii) subjecting the mixture to a non-oxidizing atmosphere at a peak temperature in a range from about 25° C. to about 250° C. to produce a supported chromium catalyst;
- and
- (iii) contacting the supported chromium catalyst and a co-catalyst with ethylene and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce from about 2000 to about 10,000 grams of the ethylene polymer per gram of the supported chromium catalyst per hour;
- wherein the ethylene polymer has a melt index in a range from 0 to about 0.5 g/10 min.
2 more elements
An olefin polymerization process, the process comprising:
- (i) combining chromium (III) acetylacetonate with an activator-support comprising a fluorided solid oxide and/or a sulfated solid oxide to form a mixture;
- (ii) subjecting the mixture to an inert atmosphere at a peak temperature to produce a supported chromium catalyst;
- and
- (iii) contacting the supported chromium catalyst and a co-catalyst with ethylene and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an ethylene polymer;
- wherein
- the molar ratio of co-catalyst:chromium is in a range from about 50:1 to about 500:1;
- the polymerization reactor system comprises a loop slurry reactor, gas-phase reactor, solution reactor, or a combination thereof;
- and
- the ethylene polymer has a melt index in a range from 0 to about 0.5 g/10 min, and a ratio of Mw/Mn in a range from about 35 to about 150.
6 more elements
Dependencies are inferred from the claim text.