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. 07, 1989
Filed:
Sep. 30, 1987
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
Process for separation and purifying pigment suspensions and suspensions of pigment intermediates in a liquid by means of a membrane separation process, whereby the suspension to be treated is uniformly fed to and circulated through a microfiltration unit containing at least one semi-permeable membrane and the separated liquid flows off through the membrane as permeate which process comprises replacing the permeate gradually by a washing liquid that differs from the first liquid such that the total amount of washing liquid fed into the system is 1 to 15 times the total volume of the initial suspension, and separating the resultant suspension from the liquid by means of conventional filtration or drying apparatus. The process is particularly suitable for processing fine pigment suspensions often obtained in pigment synthesis.