The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 30, 1998
Filed:
May. 14, 1997
Hoechst Aktiengesellschaft, , DE;
Abstract
A process for preparing aldehydes comprising hydroformylating olefinically unsaturated compounds with hydrogen and carbon monoxide in a homogeneous phase in the presence of a catalyst system comprising rhodium complex compounds and aromatic phosphines in a molar excess and separating off the catalyst system from the hydroformylation reaction mixture by pressure filtration on a semipermeable membrane of an aromatic polyamide by carrying out the hydroformylation at a pH of 2.5 to 4.3 using a molar ratio of phosphine:rhodium of at least 60 and at a rhodium concentration of at least 10 ppm by weight, based on the olefinically unsaturated compound used, and using, as aromatic phosphines, special alkylammonium and/or arylammonium salts of sulfonated or carboxylated triarylphosphines which process leads to excellent activities and selectivities in the hydroformylation step itself and also to high retention values in the membrane filtration step.