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:
Oct. 05, 1976
Filed:
Dec. 21, 1973
Ernst Spietschka, Oberauroff, Taunus, DT;
Siegfried Schiebler, Frankfurt am Main, DT;
Wolfgang Tronich, Frankfurt am Main, DT;
Hoechst Aktiengesellschaft, Frankfurt am Main, DT;
Abstract
A process for preparing very pure copper phthalocyanine pigments of the .alpha.-modification, wherein substituted or unsubstituted copper phthalocyanines having different degrees of purity are converted into copper phthalocyanine salts capable of being isolated, with the aid of suitable acids which dissolve the impurities contained in the dyestuff, wherein these salts are separated from the acid, the copper phthalocyanines of the .alpha.-modification are set free in a pure form from the copper phthalocyanine salts by the action of water and wherein the isolated copper phthalocyanine is subject in an aqueous suspension to a mechanical fine division. This process yields copper phthalocyanines of the .alpha.-modification in a very pure form without causing problems with respect to the waste water.