Process for the preparation of polyurethanes containing uretdione rings

US4894429A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gerhard Grogler · Leverkusen, DE
• Heinrich Hess · Cologne, DE
• Richard Kopp · Cologne, DE

Key dates

• Filing date: Aug 26, 1988
• Grant date: Jan 16, 1990
• Expiry date: Aug 26, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/798
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Polyurethanes containing uretdione rings are produced by reacting a polyisocyanate containing a uretdione ring with a relatively high molecular weight dihydroxyl compound in the presence of a bismuth salt of an organic carboxylic acid and a low molecular weight aromatic diamine. The low molecular weight aromatic diamine is used in a quantity which is 5 to 10 times the quantity of bismuth salt used. These solid polyurethanes are formed in relatively short reaction times and possess outstanding mechanical properties.