Silver sol, preparation thereof, coating material for forming transparent conductive film and transparent conductive film

摘要

A silver sol comprises silver particles having a particle size ranging from 1 to 100 nm and a silver solid content ranging from 1 to 80% by weight. The silver sol can be prepared by a method comprising the steps of reacting a solution of a silver compound with a reducing agent at a temperature ranging from 5 to 50° C. and a stirring speed falling within the range of from 1,000 to 10,000 rpm to form silver fine particles; recovering the resulting silver fine particles using a centrifugal separator; and then dispersing the silver fine particles in a medium to give a silver sol having a silver solid content ranging from 1 to 80% by weight. The silver sol or a coating material obtained by diluting the sol to a desired silver solid content and, if desired, adding a binder permits the formation of a transparent conductive film on, for instance, a cathode-ray tube while reducing the production cost. The resulting transparent conductive film has high transparency suitably used for coating a cathode-ray tube, excellent conductivity, in particular, good electromagnetic shielding properties and a surface resistance of not more than 10.sup.3 &OHgr;/□.