Process for the distillation of a mixture of isomeric diisocyanatodiphenylmethanes

US7649108B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Hans-Peter Schal · Dormagen, DE
• Ulrich Wolf · Laax, CH
• Bernd Thelen · Leverkusen, DE

Key dates

• Filing date: May 4, 2004
• Grant date: Jan 19, 2010
• Expiry date: Jul 29, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C263/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A mixture of isomeric diisocyanatodiphenylmethanes composed of at least 2,2′-diisocyanato-diphenylmethane, 2,4′-diisocyanatodiphenylmethane and 4,4′-diisocyanatodiphenyl-methane is distilled in at least one stage and a divided-wall column is used in at least one distillation stage.