Patent attributes
The ultrafine particle producing process introduces materials for producing ultrafine particles into a thermal plasma flame under reduced pressure to form a vapor-phase mixture, introduces a reactive gas and a cooling gas toward an end portion of the thermal plasma flame in supply amounts sufficient for quenching the vapor-phase mixture to generate the ultrafine particles and allows the resultant ultrafine particles to come into contact with the reactive gas so as to produce the ultrafine particles whose surfaces are coated with a thin film including one or more components compound derived from decomposition and/or reaction of the reactive gas, for example, an elementary carbon substance and/or a carbon. According to the process, thin film-coated ultrafine particles having high level uniformity in particle size and shape can be produced.
