PREPARATION OF NOBLE METAL ORGANOSOL

摘要

PURPOSE:To efficiently convert a specific noble metal hydrosol to a noble metal organosol, by adding a nonionic surfactant to the specific noble metal hydrosol before or after the reducing treatment thereof to evaporate said hydrosol to dryness before adding an aprotic org. solvent thereto. CONSTITUTION:An aqueous solution containing a salt of a noble metal such as ruthenium, palladium and platinum is subjected to reducing treatment in the presence or absence of a protective agent to form a noble metal hydrosol and a nonionic surfactant is added to said hydrosol before and after the reducing treatment thereof to dissolve the same. Next, the resulting mixture is evaporated to dryness to remove water being a dispersing medium and an org. solvent is added to the dried one to again dissolve the same to prepare a noble metal organosol. In the reducing treatment of the noble metal, a reducing agent of an aqueous solution containing sodium borohydride or potassium borohydride is suitably used.