Electrically conductive emulsion ink and method for producing electrically conductive thin film using the same

摘要

An electrically conductive emulsion ink is provided, which can form an electrically conductive thin film from metal nanoparticles on various substrates at a relatively low temperature in short time with simple procedures. The emulsion ink comprises an oil phase containing metal nanoparticles and a water phase containing a reducing agent for the metal nanoparticles and/or a photocatalyst. An electrically conductive film can be formed by coating or patterning the emulsion ink on a substrate surface, and then subjecting the coated ink to heat treatment and/or ultraviolet irradiation so as to reduce the metal nanoparticles. Heat treatment is preferably conducted at 40-100°C. Ultraviolet irradiation can be performed at room temperature. Preferably, the oil phase comprises a non-aqueous dispersion medium and metal nanoparticles dispersed in the medium, and the metal nanoparticle are obtained by amine reduction method and coated with a protecting agent having a linear or branched alkyl group with 10-20 carbon atoms.