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:
Jan. 26, 1999
Filed:
Apr. 04, 1997
Mitsuo Shinomiya, Canton, MI (US);
Masashi Takahashi, Tokyo, JP;
Satoshi Miyamoto, Toyonaka, JP;
Tamotsu Sobata, Ibaraki, JP;
Nippon Paint Co., Ltd., Osaka, JP;
Abstract
Disclosed is a method for zinc phosphating a molded metal article wherein a treating bath composition comprises from 1.5 to 5.0 g/l of zinc ion, from 0.1 to 3.0 g/l of manganese ion, from 5 to 40 g/l of phosphate ion, from 0.05 to 3.0 g/l of a fluorine compound as HF and hydoxylamine as a chemical conversion accelerator. A concentration of hydroxylamine is maintained to satisfy the following relationship: 0.5.ltoreq.�hydroxylamine!(g/l)-2.0.times.�Fe.sup.2+ !(g/l).ltoreq.3.0 The treating bath is agitated by a vibratory agitating means provided in the treating vessel so that a mean acceleration a of a treating solution present within a bath region in which the molded metal article is immersed to be treated under fluid agitation is at least 8 cm/sec.sup.2. The mean acceleration is calculated from the following equation: ##EQU1## wherein values of X, Y and Z, each in unit of cm/sec.sup.2, indicate average acceleration values of treating solution in three respective X, Y and Z axial directions which are perpendicular to each other. The velocity changes of the treating solution in a flow state in respective X, Y and Z directions are synchronously measured at measuring locations for 60 seconds to be averaged to obtain the respective average acceleration values in X, Y and Z directions.