Nissan Motor Company Limited

Hitoshi Kunimi

Mikio Kawai

Teruko Yoshimoto

A method of electrodepositing a hexacyano-cobalt iron complex of the general formula Fe.sub.x [Co(CN).sub.6 ].sub.y, where 3.ltoreq.x.ltoreq.4 and 2.ltoreq.y.ltoreq.3, which serves as an electrochromic material high in memory effects and quick in response. A film of the cyano-complex is electrodeposited from an aqueous mixed solution of K.sub.3 [Co(CN).sub.6 ] and an iron(III) salt such as FeCl.sub.3. During the electrolytic reduction process the cathode potential is periodically increased and decreased over a predetermined range, preferably from -0.2 to +1.2 V, to stably accomplish electrodeposition to thereby obtain an electrochromic film which is uniform in physical properties and even in the tone and tint of the color. The sweep of the cathode potential may be made in the manner of a saw-tooth wave, rectangular wave or sinusoidal wave.

Growing community of inventors

Yokosuka, Japan

Hitoshi Kunimi