Process for the production of light-colored isocyanates

US7368595B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Stefan Wershofen · Mönchengladbach, DE
• Torsten Hagen · Essen, DE
• Christian Steffens
• Jeffrey Bolton · Mülheim an der Ruhr, DE

Key dates

• Filing date: Jan 10, 2007
• Grant date: May 6, 2008
• Expiry date: Jan 10, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/14
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to an improved process for the production of isocyanates by the reaction of an amine or a mixture of two or more amines with phosgene, the improvement involving the phosgene containing less than about 100 ppm of sulfur in elemental or bound form. The inventive process yields light-colored isocyanates that are suitable for the production of polyurethanes or their precursors (e.g. prepolymers) without the treatment processes heretofore required.