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:
Mar. 01, 2005
Filed:
May. 21, 2001
Jacek Malisz, Grenzach-Wyhlen, DE;
Adolf Käser, Bottmingen, CH;
Rainer Kaufel, Hartheim, DE;
Holger Lautenbach, Grenzach-Wyhlen, DE;
Elke Polley, Grenzach-Wyhlen, DE;
Martina Hoffmann, Hausen, DE;
Jacek Malisz, Grenzach-Wyhlen, DE;
Adolf Käser, Bottmingen, CH;
Rainer Kaufel, Hartheim, DE;
Holger Lautenbach, Grenzach-Wyhlen, DE;
Elke Polley, Grenzach-Wyhlen, DE;
Martina Hoffmann, Hausen, DE;
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Abstract
Described is a process for preparing concentrated solutions or suspensions of anionic organic compounds which comprises a) acidifying an aqueous solution or suspension of an anionic organic compound containing salts and/or impurities to a pH of 4.5 or less, if the pH is above this value, so that b) the anionic organic compound is water-insoluble and precipitates in the form of the free acid, c) bringing the suspension to a salt content below 2% by weight, based on the total weight of the retentate, by means of ultrafiltration with a membrane having pore diameters of from 0.001 to 0.02 μm, and d) optionally washing out the salts with water having a pH below 4,5, e) optionally carrying out acid-free washing with water thereafter, and then f) concentrating, so that the amount of anionic organic compound is 5-50% by weight, and g) if desired, bringing the anionic organic compound into solution by adding an appropriate base.