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:
Apr. 14, 1987
Filed:
May. 07, 1985
Shigeki Matsuda, Okazaki, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A method of forming a chemical phosphate coating on the surface of steel with a treatment bath made without directly adding any oxidizing agent such as nitrite ions or hydrogen peroxide, and maintaining its temperature in a range not exceeding 40.degree. C., its pH in the range of 2.5 to 4.5 and its oxidation-reduction potential (ORP in terms of the normal hydrogen electrode potential) in the range of 150 to 550 mV. The bath is formed from an aqueous solution of the two components, i.e. the first component, an acidic solution consisting mainly of oxo acid ions, such as, NO.sub.3.sup.-, phosphoric ions (H.sub.3 PO.sub.4 or H.sub.2 PO.sub.4.sup.-), and metal ions, such as Zn.sup.2+, and the second component, an alkaline solution containing hydroxide ions (OH.sup.-). Preferably, the bath has a temperature of 20.degree. C. to 30.degree. C., a pH value of 3.0 to 4.0 and an ORP of 350 to 450 mV.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile