Nihon Parkerizing Co., Ltd.

Parker Chemical Company

Parker Netsushorikogyo K.k.

Ryuji Kojima

Yasunobu Matsushima

Kuniji Yashiro

Kentaro Nagano

Humihide Nakamura

Kazuhiro Ishikura

Yasuo Imai

Toshiko Totsuka

Akiko Yazaki

Yoshiyasu Yoneyama

Yoshio Moriya

A highly reliable detoxifying method of the cyano matters is provided. The waste-liquor, which contains at least one of free cyano material, a cyano complex and a reducing compound exhibiting volatility in alkaline aqueous solution, is heated under an alkaline condition to a temperature range, which lies within a range of from room temperature to the boiling point, and which includes a high temperature range of 80&#xb0; C. or more, followed by holding the temperature; oxidation-reduction potential of the waste liquor is measured from the room temperature; and, hypochlorite is intermittently or continuously added to the waste liquor from the room temperature, until the oxidation-reduction of the hypochlorite is detected.

Method for treating cyanide waste liquid

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

A method for determining the coating weight and composition of a zinc phosphate coating on a ferrous metal surface comprises stripping the coating from a known area using an aqueous solution of sodium hydroxide and triethanolamine, thereafter measuring the iron and phosphate contents by colorimetric analysis of the stripping solution and then determining the coating weight and composition based on such measurements.

Test method for phosphate coatings

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Tokyo, Japan

Ryuji Kojima