Title:
TREATMENT SOLUTION FOR FORMING BLACK, HEXAVALENT CHROMIUM-FREE CHEMICAL CONVERSION COATING ON GALVANIZING AND GALVANNEALING, AND METHOD FOR FORMING BLACK, HEXAVALENT CHROMIUM-FREE CHEMICAL CONVERSION COATING ON GALVANIZING AND GALVANNEALING
Document Type and Number:
Japanese Patent JP3774415
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a treatment method for forming a black, hexavalent chromium- free chemical conversion coating having corrosion resistance equal to or larger than that of the conventional hexavalent chromium-containing coating on galvanizing and galvannealing.
SOLUTION: The treatment solution is used for forming a black, hexavalanet chromium-free coating on galvanizing and galvannealing. In the treatment solution, the molar ratio between nitric ions and tervalent chromium (NO3-/Cr3+) is <0.5, and the tervalent chromium is present in the form of a water soluble complex with a chelating agent. The treatment solution contains cobalt ions and/or nickel ions, and the cobalt ions and/or nickel ions form a hardly soluble metal salt with the chelating agent, and are stably present in the treatment solution without undergoing precipitation. When galvanizing and galvannealing are brought into contact with the treatment solution, the treatment solution is reacted with zinc, so that a black, hexavalent chromium-free chemical conversion coating containing the zinc, chromium, cobalt and/or nickel, and chelating agent is formed on the galvanizing and galvannealing.
Inventors:
Manabu Inoue
Ryo Nakashima
Kazuhiro Watanabe
Kimitaka Watanabe
Ryo Nakashima
Kazuhiro Watanabe
Kimitaka Watanabe
Application Number:
JP2002070175A
Publication Date:
May 17, 2006
Filing Date:
March 14, 2002
Export Citation:
Assignee:
Dip sole Co., Ltd.
International Classes:
C23C22/13; C23C22/10; C23C22/46; C23C22/47; C23C22/53; C23C28/00; (IPC1-7): C23C22/13; C23C22/53; C23C28/00
Domestic Patent References:
| JP2000509434A | ||||
| JP2000017451A | ||||
| JP11335865A | ||||
| JP9202977A | ||||
| JP61048574A | ||||
| JP2000054157A |
Attorney, Agent or Firm:
Minoru Nakamura
Fumiaki Otsuka
Sadao Kumakura
Shishido Kaichi
Hideto Takeuchi
Toshio Imajo
Nobuo Ogawa
Village shrine Atsuo
Takaki Nishijima
Atsushi Hakoda
Fumiaki Otsuka
Sadao Kumakura
Shishido Kaichi
Hideto Takeuchi
Toshio Imajo
Nobuo Ogawa
Village shrine Atsuo
Takaki Nishijima
Atsushi Hakoda