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:
Jul. 27, 1993
Filed:
Oct. 02, 1991
Yoshio Shindou, Chiba, JP;
Motoo Kabeya, Chiba, JP;
Shiro Fujii, Chiba, JP;
Makoto Yoshida, Fukuoka, JP;
Teruaki Izaki, Fukuoka, JP;
Takao Ogino, Tokyo, JP;
Arata Suda, Tokyo, JP;
Takayuki Aoki, Tokyo, JP;
Nihon Parkerizing Co., Ltd., Tokyo, JP;
Abstract
A chromating liquid for forming a chromate film on a Zn or Zn-alloy plated steel sheet, is prepared by adding and mixing a silane coupling agent in a molar ratio of from 0.05 to 0.3 relative to Cr.sup.6+ contained in an aqueous chromating liquid which contains 1-30 g/l of Cr.sup.6+ and 1-30 g/l of Cr.sup.3+ at a weight ratio of Cr.sup.6+ /Cr.sup.3+ ranging from 0.1 to 2.0; and further contains 1-59 g/l of hydrofluoric acid and 1-59 g/l of phosphoric acid at total of hydrofluoric acid and phosphoric acid ranging from 2 to 60 g/l and at a weight ratio of (fluoride ions+phosphate ions)/Cr.sup.3+ ranging from 0.5 to 3.5. and, further said chromating liquid is applied on a surface of the zinc-based plated steel sheet and is then dried, thereby forming the chromate film having a coating amount of from 10 to 150 mg/m.sup.2 in terms of the chromium.