Particle size control of supported chromium catalysts in loop slurry polymerization reactors
US11325997B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2021 |
| Grant date | May 10, 2022 |
| Priority date | — |
| Expiry date | Dec 7, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2410/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.