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:
Aug. 21, 1984
Filed:
Sep. 13, 1982
Paul Horlacher, Mohlin, CH;
Heinz Pfenninger, Lupsingen, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
A process is described for the preparation of concentrated liquid formulations, stable on storage, of anionic fluorescent brighteners, which process consists in passing a crude (for example obtained from synthesis) aqueous solution or dispersion of a fluorescent brightener containing sulfo groups, in particular a stilbene fluorescent brightener belonging to the group comprising bistriazinylaminostilbenedisulfonic acids, bis-styrylbiphenyls, bis-styrylbenzenes and bis-triazolylstilbenedisulfonic acids, is passed through a semipermeable membrane which contains ionic groups and has a pore diameter of 1-500 .ANG. in order to remove salts and by-products from the synthesis having molecular weights below 500 and in order to remove part of the water. The resulting concentrated preparation can, if desired, be concentrated further and/or treated with formulation assistants and, if desired, further additives.