Yttrium and rare earth compounds catalyzed lactone polymerization

• US 5,095,098 A
• Filed: 04/03/1991
• Issued: 03/10/1992
• Est. Priority Date: 09/29/1989
• Status: Expired due to Term

• Current Assignee: NatureWorks LLC (Cargill, Inc. (Agricultural Services Division))
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: McLain, Stephan J., Drysdale, Neville E.
• Primary Examiner(s): Stoll, Robert L.
• Assistant Examiner(s): SAYALA, CHHAYA D
• Application Number:
  US07/680,165
• Time in Patent Office: 342 Days
• Field of Search: 534/15
• US Class Current: 534/15
• CPC Class Codes: C08G 63/08 Lactones or lactides
• CPC Class Codes: C08G 63/823 for the preparation of polylactones or polylactides

Abstract

Process for yttrium and rare earth compound catalyzed polymerization of lactones and the living polymer compositions of such polymerizations, novel polyester products of such polymerizations and novel yttrium and rare earth metal compounds useful as catalysts in the polymerization of biodegradable polymers for medical uses and flexible films for packaging.

Claims

1. A compound of the formula MZ₃, wherein M is yttrium or a rare earth metal, two of the Z groups are 2,2,6,6,-tetramethylhepta-3,5-dionate and the other Z group is --OCR¹₃, --NR¹₂, or --CR¹₃ wherein R¹ is hydrogen, hydrocarbyl or substituted hydrocarbyl.

2. A compound of claim 1 wherein M is yttrium or a rare earth metal, two of the Z groups are 2,2,6,6-tetramethylhepta-3,5-dionate, and the third Z group is isopropoxide.