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:
May. 29, 1984
Filed:
Mar. 24, 1982
Joachim Kranz, Ludwigshafen, DE;
Wolfgang Habermann, Mainz, DE;
Harry Distler, Bobenheim, DE;
Helmut Knittel, Ludwigsburg, DE;
Karl-Ludwig Hock, Ludwigshafen, DE;
Fritz Brunnmueller, Limburgerhof, DE;
Rolf Schneider, Mannheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Blue iron hexacyanoferrate-III pigments (I) are prepared by anodic oxidation of metallic iron in hydrogen cyanide, or a reaction medium containing hydrogen cyanide, at pH<7 and at an anode potential of .ltoreq.0.76 V (measured against a standard hydrogen electrode) to complex iron-II hexacyanoferrate-II compounds (II), which are then oxidized to (I) in a conventional manner. The oxidation of (II) is advantageously carried out with air or oxygen at pH 0-4 and at from 70 to 95.degree. C., but can also be carried out at pH>8. The process gives readily dispersible pigments (I) which are of high color strength and give brilliant, glossy colorations.