PROCESS FOR PRODUCING A FINE METAL PARTICLE

摘要

A process for producing metallic fine particles having a superior reproducibility of a partice size and light absorption characteristics, metallic fine particles, a metallic fine particles-containing composition, and the use thereof, are provided. In the process for producing the metallic ions, the reduction of the metallic ions is performed in two steps using two types of reducing agents which significantly differ in reducing ability thereof, in which a reducing agent in which the reduction ability is strong is used in the first reduction step, and a reducing agent in which the reduction ability is weak is used in the second reduction step, and thereby the nano-sized metallic fine particles are produced. Preferably in the process, an aqueous metallic salt solution containing a surfactant is used and a two-step reduction is performed in the same vessel, in which as the reducing agent of the first reduction process, at least one selected from the group consisting of boron hydride, dimethylamine borane, hydrazine, and ascorbic acid is used, and as the reducing agent of the second reduction process, specific alkylamine or alkanolamine is used.