Process for removing by-products from diurethanes

US5646328A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Ludwig Deibele · Neunburg vorm Wald, DE
• Oswald Wilmes · Recklinghausen, DE
• Jurgen Dahmer · Krefeld, DE

Key dates

• Filing date: Jun 20, 1996
• Grant date: Jul 8, 1997
• Expiry date: Jun 20, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C269/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Low-boiling by-products are removed from diurethanes prepared by a phosgene-free process by carrier vapor distillation using alcohol vapor, preferably the vapor of the basic alcohol found in the diurethane, as the carrier vapor. The diurethanes freed of low-boiling by-products in this manner may be thermally decomposed to produce diisocyanates.