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:
Sep. 14, 1993
Filed:
May. 15, 1992
Isao Kawasaki, Osaka, JP;
Minoru Ishida, Osaka, JP;
Asao Mochizuki, Aichi, JP;
Haruo Kojima, Aichi, JP;
Nippon Paint Co., Ltd., Osaka, JP;
Abstract
A method for treating a metal surface with zinc phosphate of this invention can treat an iron-based surface, a zinc-based surface, an aluminum-based surface as well as a metal surface having two kinds or more of these surfaces with the same zinc phosphate treating solution, and even if treating times increases, the method makes it possible to form a coating film having superior adhesion and high corrosion resistance under a stable condition, and also, it prevents a precipitate formed by a metal ion eluted from a metal surface to be treated, especially, by an aluminum ion. A complex fluoride compound contained in said zinc phosphate treating solution of coming in contact with a metal surface is added so that a concentration (unit: g/l) converted into at least one of a hexafluorosilicic acid group (SiF.sub.6.sup.2-) and a tetrafluoroboric acid group (BF.sub.4.sup.-), with an aluminum ion concentration (unit: g/l) contained in said treating solution, is satisfactory for the following equation (I). ##EQU1##