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:
Jun. 05, 1990
Filed:
Mar. 30, 1989
Shizuo Shima, Kanagawa, JP;
Soei Koizumi, Kanagawa, JP;
Nihon Parkerizing Co., Ltd., Tokyo, JP;
Abstract
A deeply and uniformly black coating with excellent adhesion and corrosion resistance can be formed on a wide variety of substrates by coating them with an aqueous composition containing an amount of chromium trioxide to give a stoichiometric equivalent of from about 30 to about 150 g/L of Cr.sup.6+ ; from about 20 to about 100 g/L of Cr.sup.3+ ; a component to provide a stoichiometrically equivalent amount of from about 0.5 to about 50 g/L of total Fe, Co, and Ni ions; from about 5 to about 200 g/L of dispersed or dissolved organic film forming polymer; and the balance water, with a weight ratio of Cr.sup..alpha.6 to Cr+3 between about 5 and about 1; and heating the coated substrate to a temperature between 100.degree. and 350.degree. C. for 5 seconds to 10 minutes.