Patent ID: 8821706

Claim:
A method for producing a conductive polymer film at a constant film-forming speed, using an apparatus comprising a prism having a working electrode formed on its one surface, a light-emitting means and a light probe disposed on both sides of said prism, a container attached to said prism in a liquid-tight manner with its open side facing said working electrode, an electrolytic solution containing a conductive-polymer-forming monomer and a dopant, which is contained in said container, a counter electrode immersed in said electrolytic solution, a power supply means connected to said working electrode and said counter electrode, and a controller connected to said light probe and said power supply means, the method comprising (1) forming said conductive polymer film on said working electrode by supplying current from said power supply means to said working electrode and said counter electrode, while projecting light from said light-emitting means to said prism, (2) determining an absorption spectrum by said light probe from the light reflected by said conductive polymer film, which exits from said prism, (3) determining the relation between the time period of forming said conductive polymer film and the thickness of said conductive polymer film from the relation between the change of absorbance with time obtained from said absorption spectrum and the thickness of said conductive polymer film, at plural current levels, (4) determining the relation between current and the film-forming speed in a short time interval from the relation between the time period of forming said conductive polymer film and the thickness of said conductive polymer film at each current level, and storing it in said controller, and (5) controlling the current based on said relation of current and the film-forming speed, such that the speed of forming said conductive polymer film is constant.