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:
Aug. 09, 1994
Filed:
Apr. 30, 1992
Shigeki Matsuda, Okazaki, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A process for a chemical treatment with a phosphate by bringing a steel material into contact with a phosphate chemical treatment bath maintained at 40.degree. C. or less and containing a phosphate ion, a nitrate ion, a chemical film formable metal ion and an oxidizing agent, to cause a film formation reaction between the phosphate chemical treatment bath and the steel material, whereby a phosphate chemical film is formed on the surface of the steel, wherein a circulation path for withdrawing a portion of the phosphate chemical treatment bath and returning the withdrawn phosphate chemical treatment bath to the bath is provided, and a filter comprising an inorganic material composed of SiO.sub.2 and Al.sub.2 O.sub.3 is provided in the circulation path, of which filter not only enables sludge from the phosphate chemical treating solution to be physically removed but also prevents changes the chemical structure in the form of a solution.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile