Method for making polyolefins

US6908972B2 · kind B2 · utility

Assignee

• Equistar Chemicals, LP · US

Inventors

• Barbara M. Tsuie · Cincinnati, US
• Karen L. Neal-Hawkins · Cincinnati, US
• Sandor Nagy · Naperville, US
• Michael W. Lynch · Sharonville, US
• Mark P. Mack · Sharonville, US
• Shaotian Wang · Mason, US
• Jean A. Merrick-Mack · Sharonville, US
• Clifford C. Lee · Houston, US
• Joel A. Mutchler · Porter, US
• Kenneth W. Johnson · Sharonville, US

Key dates

• Filing date: Apr 16, 2002
• Grant date: Jun 21, 2005
• Expiry date: Jun 21, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F210/16
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A method for making ethylene polymers and copolymers is disclosed. The method uses a catalyst system comprising a low level of an aluminum-containing activator, a bridged indenoindolyl transition metal complex, and a treated silica support. The method enables economical preparation of ethylene copolymers having very low density. The silica-supported, bridged complexes incorporate comonomers efficiently and are valuable for a commercial slurry loop process. Use of a bridged indeno[2,1-b]indolyl complex provides exceptionally efficient comonomer incorporation, and gives polymers with a substantial and controlled level of long-chain branching. The method facilitates the production of a wide variety of polyolefins, from HDPE to plastomers.