Nihon Parkerizing Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Kazuhiro Ishikura

Kentaro Nagano

Yasunobu Matsushima

Eisaku Okada

Hiroyuki Sato

Takaomi Nakayama

Tadashi Matsushita

Ryuji Kojima

Fumiya Yoshida

Katsuhiro Shiota

Michiro Kurosawa

Yoshio Moriya

Yasuo Imai

A composition for surface treatment of aluminium, aluminum alloys, magnesium or magnesium alloys and the treating solutions being diluted to the desired concentration are defined. The composition contains (1) compound A containing at least one metal element selected from the group consisting of Hf(IV), Ti(IV) and Zr(IV), (2) a fluorine-containing compound of sufficient amount to make fluorine exist in the composition in an amount of at least 5 times the molarity of the total molarity of the metal contained in the above-mentioned compound A, (3) at least one metal ion B selected from the group of alkaline earth metals, (4) at least one metal ion C selected from the group consisting of Al, Zn, Mg, Mn and Cu, and (5) nitric ion and the mol concentration of compound A is 0.1-50 mmol/L as the metal element of Hf(IV), Ti(IV) and Zr(IV). A metal treated with the treating method of the present invention solution has an excellent resistance to various corrosive environments.

Surface treating solution for surface treatment of aluminum or magnesium metal and a method for surface treatment

This invention concerns a humidity sensor wherein a chemical conversion coating, giving attention to the property that it undergoes an impedance decrease with adsorption of moisture, is used as humidity sensing element which is characterizied by an extremely short electrode distance, greatly improved sensitivity, high speed response, stable performance over a long period of time, high reliability and cheaper production cost. The principal point that characterizes the humidity sensor in this invention is that the chemical conversion coating deposited on the metal surface with or without an electrolysis application, is made usable as a humidity sensing element. For the chemical conversion coating, such coatings as phosphate, oxalate, titanium fluoro-complex, chromium phosphate and non-chromium types are used. On top of this chemical conversion coating, application of a humidity sensing film is effected to further improve humidity sensing performance.

Humidity sensor

Growing community of inventors

Tokyo, Japan

Kazuhiro Ishikura