Low by-product content polyphenylene polymethylene polyisocyanates

US10501406B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Michael Lorenz · Bad Zwischenahn, DE
• Axel Franzke · Goldkronach, DE
• Robert Baumann · Mannheim, DE
• Michael Bock · Ruppertsberg, DE
• Geert Janssens · Friedelsheim, DE

Key dates

• Filing date: Jan 22, 2016
• Grant date: Dec 10, 2019
• Expiry date: Mar 9, 2036

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/46
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to polyphenyl polymethylene polyisocyanates having an NCO number of at least 29% comprising less than 2% by weight ureas, less than 8% by weight carbodiimides or uretonimines and less than 1000 ppm organic chlorine compounds.The polyphenyl polymethylene polyisocyanates can be prepared according to the invention by reacting The polyphenyl polymethylene polyisocyanates can further be prepared according to the invention, prior to the thermal cleavage, by removing compounds having free amino groups or urea groups present in the carbamate crude mixture from the carbamate crude mixture by filtration of the carbamate crude mixture comprising the polyphenyl polymethylene polycarbamates over a solid acidic adsorbent in the presence of an acid dissolved in the carbamate crude mixture.