Patent · US Expired

Recovery of catalyst systems from diaryl carbonate-containing reaction solutions by suspension crystallization

US5965472A · kind A · utility

2Cited by

3References

7Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Hans-Josef Buysch · Krefeld, DE
Carsten Hesse · Krefeld, DE
Johann Rechner · Krefeld, DE
Hans-Peter Wirges · Krefeld, DE

Key dates

Filing date	Apr 1, 1997
Grant date	Oct 12, 1999
Priority date	—
Expiry date	Apr 1, 2017

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C68/01
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Catalyst systems with a content of a platinum-group-metal catalyst, a co-catalyst, a quaternary salt and a base for the oxidative carbonylation of aromatic hydroxy compounds to the corresponding diaryl carbonates are according to the invention obtained as a mother liquor by suspension crystallization and can be returned into the carbonylation reaction or worked up to valuable materials. The crystallizate, which consists predominantly of diaryl carbonate and the parent aromatic hydroxy compound, is worked up to pure diaryl carbonate and pure hydroxy compound.

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