Honda Motor Co., Ltd.

Dipsol Chemicals Co., Ltd.

Toshiyasu Nagai

Hiroyuki Yoshida

Shinsuke Mochizuki

Hiroshi Hirayama

Manabu Inoue

Kenichi Nishikawa

Toshiki Inomata

Daisuke Sadohara

Yasutake Nemichi

Katsumi Shimoda

Yasuhiro Kato

Provided is a black coupling member for vehicles, comprising a trivalent chromium black chemical conversion film and a black coating film upon the trivalent chromium black chemical conversion film, on the surface of a zinc-plated metal substrate. The trivalent chromium black chemical conversion film is formed using a hexavalent chromium-free trivalent chromium black chemical conversion treatment solution having a Zn ion concentration of no more than 20 g/L. The lightness (L) of the trivalent chromium black chemical conversion film is no more than 33. The black coating film includes a black chemical conversion component, a modified organopolysiloxane, and a friction coefficient-adjustment component. The black chemical conversion component content is 2-25 wt % relative to 100 wt % of the black coating film. The lightness (L) is no more than 28.

Black coupling member for vehicles, having excellent corrosion resistance and black appearance

An object is to provide a technique capable of forming a film having a dark black appearance and high corrosion resistance on a zinc plated component in a simple process, and a black coating film-forming vehicle component and/or fastening component that is obtained by: treating a surface of a zinc plated metal substrate with a black chemical conversion treatment agent containing trivalent chromium as an active ingredient, to form a black chemical conversion treatment film having an L value (brightness) of from 33 to 30; coating a black coating composition containing a black pigment in an amount of from 25 to 65% by weight in a thermosetting film-forming component and an alkoxysilane oligomer, on the black chemical conversion treatment film; and heat-curing the black coating composition thus coated.

Black coating film-forming vehicle component and/or fastening component, and manufacturing method thereof

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Wako, Japan

Toshiyasu Nagai