Particle size control of metallocene catalyst systems in loop slurry polymerization reactors

US11326005B1 · kind B1 · utility

Assignee

• Chevron Phillips Chemical Company LP · US

Inventors

• Max P. McDaniel · Bartlesville, US
• Carlton E. Ash · Sugar Land, US
• Kathy S. Clear · Bartlesville, US
• Eric D. Schwerdtfeger · Bartlesville, US
• Carlos A. Cruz · Bartlesville, US
• Jeremy M. Praetorius · Bartlesville, US
• Youlu Yu · Bartlesville, US

Key dates

• Filing date: Jul 8, 2021
• Grant date: May 10, 2022
• Expiry date: Jul 8, 2041

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2323/20
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 μm and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.