Patent · US Active

Process for preparing methylenedi(phenyl isocyanate)

US8907124B2 · kind B2 · utility

0Cited by

5References

20Claims

0Family size

Assignee

BASF SE

Inventors

Michael Bock · Ruppertsberg, DE
Kai Thiele · Ekeren, BE
Heiner Schelling · Ludwigshafen, DE

Key dates

Filing date	Nov 17, 2011
Grant date	Dec 9, 2014
Priority date	—
Expiry date	Jun 1, 2032

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C263/20
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The invention relates to a process for preparing methylenedi(phenyl isocyanate), which comprises (a) the phosgenation of two-ring and/or multiring methylenedi(phenylamine), (b) the fractionation of the crude methylenedi(phenyl isocyanate) obtained to give two-ring and multiring isomers, (c) the purification and/or fractionation of the resulting mixture of two-ring isomers of methylenedi(phenyl isocyanate) and (d) the storage of the mixtures obtained in step (c) or in step (b), wherein part of the stored mixtures is reused by means of recirculation in at least one of steps (b) or (c).

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