Patent · US Expired

Process for the preparation of di- and polyamines of the diphenylmethane series

US7186857B2 · kind B2 · utility

10Cited by

1References

5Claims

0Family size

Assignee

Bayer MaterialScience AG · DE

Inventors

Heinz Muller · Krefeld, DE
Stefan Wershofen · Mönchengladbach, DE
Stefan Peter Grabowski · Neuss, DE

Key dates

Filing date	Oct 25, 2005
Grant date	Mar 6, 2007
Priority date	—
Expiry date	Oct 25, 2025

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C209/78
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The present invention relates to a process for the preparation of di- and polyamines of the diphenylmethane series, and to the preparation of di- and poly-isocyanates of the diphenylmethane series from these di- and poly-amines. The di- and poly-amines of the diphenylmethane series are prepared by the reaction of aniline and formaldehyde in the presence of hydrochloric acid. In with the present invention, the hydrochloric acid employed contains less than 0.001 wt. % of metal ions which are divalent and/or more than divalent.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.