Honda Motor Co., Ltd.

Nippon Paint Compnay, Ltd.

Nippon Steel Corporation

Nippon Paint Surf Chemicals Co., Ltd.

Basf Japan, Ltd.

Katsuyoshi Kaneko

Toshiyuki Ishii

Hiroyuki Morishita

Fumiaki Niisato

Koki Tanaka

Kazuhiko Honda

Keisuke Kojima

Kaoru Yamazaki

Takayuki Ueno

Yuki Kasahara

Yoshitaka Okitsu

Shigeyuki Mizuno

Kageki Fujimoto

Yoshikazu Umeno

Tatsumasa Hidaka

Toshiyuki Katsumi

Takahiro Tanae

Osamu Izumi

Yu Koganezawa

Yuji Ohtake

Yuya Kotani

Koichiro Izumi

Provided is a method of performing pre-paint treatment of an automobile body including a high-tensile steel sheet, in which desirable corrosion resistance can be obtained after painting. A method of performing pre-paint treatment of an automobile body, the method including performing an alkaline degreasing step, a first water-washing step, a chemical conversion treatment step, a second water-washing step, and a cationic electrodeposition painting step, in this order, wherein the chemical conversion treatment step is performed using an chemical conversion treatment agent including zirconium (A), free fluorine ions (B), an allylamine-diallylamine copolymer (C), aluminum ions (D), nitrate ions (E) each at a predetermined concentration; the allylamine-diallylamine copolymer (C) forms an acid addition salt having an anionic counter ion, and the pKa of an acid thereof falls within the range of &#x2212;3.7 to 4.8; and the content percentage of diallylamine is 80 mol % or more and 98 mol % or less.

Method of performing pre-paint treatment of automobile body and automobile body

Disclosed is a method for the formation of multi-layer paint films with the omission of a mid-coat paint coating process. The method comprises the use of a particular aqueous colored paint (A) comprising a prescribed amount of specified titanium oxide that has been compounded, The resulting multi-layer paint films have a very bright paint color, and especially a white or light-colored color, and have excellent concealing properties. The aqueous colored paint (A) is characterized by containing from 50 to 60 mass % with respect to the whole paint solid fraction of titanium oxide of specific surface area not more than 13 m/g.

Method for the formation of multi-layer paint films

The present invention: provides a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance to the extent of securing excellent resistance to salt warm water immersion which is a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance characterized in that: said steel sheet contains, in mass, 0.16 to 0.19% C, 1.10 to 1.30% Si, 1.50 to 1.60% Mn, not more than 0.1% P and 0.015 to 0.050% Al, with the balance consisting of Fe and unavoidable impurities; the average of the amount of Si incrassating on the surface of said steel sheet is not more than 20 times the Si concentration in said steel sheet; and the area percentage of the portions where the ratio of the Si concentration on the surface of said steel sheet to the Si concentration in said steel sheet is not less than 10 is not more than 95%.

Good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance

The present invention relates to a cationic electrodeposition coating composition substantially free of lead compounds, which is excellent in curability and can be finish-coated with a splendid appearance, and an article coated with the composition. The invention provides a lead-free electrodeposition coating composition excellent in curability and a coated article, the composition being capable of forming a coating film, which emits less tin compounds to have no influence on appearance of a finish coating film and film performances.

Lead-free electrodeposition coating composition and coated article

The present invention relates to a cationic electrodeposition coating composition substantially free of lead compounds, and more specifically to a method of coating an alloyed hot-dip galvanized steel plate with the composition and a coated article obtained by the method having edge portions and general surfaces excellent in corrosion resistance. The invention provides a method of coating an alloyed hotdip galvanized steel plate with a lead-free cationic electrodeposition coating composition containing a rust preventive pigment to form an electrodeposition coating film excellent in corrosion resistance, and a coated article obtained by the electrodeposition.

Method of coating with lead-free electrodeposition coating composition and coated article

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Saitama, Japan

Katsuyoshi Kaneko