Patent · US Expired

Process for the preparation of polyisocyanates

US4405527A · kind A · utility

5Cited by

1References

7Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Gerhard Wegener · Mettmann, DE
Hartmut Knofel · Odenthal, DE
Gunther Ellendt · Krefeld, DE
Marcel Petinaux · Krefeld, DE

Key dates

Filing date	Jul 12, 1982
Grant date	Sep 20, 1983
Priority date	—
Expiry date	Jul 12, 2002

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C263/10
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Polyisocyanates are prepared by reacting a polyamine solution with a phosgene solution. Excess phosgene and hydrogen chloride formed during the reaction are removed from the reaction mixture. The solvent is subsequently removed from the reaction mixture (e.g., by evaporation and condensation) and treated with a compound containing isocyanate reactive hydrogen atoms to convert any isocyanates present into urethanes and/or ureas. The thus-treated solvent may then be reused, preferably after any urethanes and/or ureas present in the solvent have been removed.

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