Particle size control of silyl chromate catalysts and uses thereof in fluidized bed reactors

Abstract

Supported chromium (VI) catalysts containing a solid oxide, 0.05 to 5 wt. % chromium, and 0.2 to 20 wt. % carbon, in which the solid oxide or the 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 fluidized bed reactor or other suitable polymerization 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 0.5 to 3 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 (in diameter) per five grams of the ethylene polymer.

Dependencies are inferred from the claim text.