Ultrafine particles prodn. and recovery by vapour deposition - where particle carrier is moved within gas phase in chamber and ultrafine particles are evaporated by heating vaporisable material

摘要

To produce and recover ultrafine particles by vapour deposn. such as organic ultrafine photo conductive particles for electrophotographic photoreceptors, the particle carrier is moved within a gas phase in a section of a chamber and the ultrafine particles are evaporated by heating the material which can be vapourised to be laid on the moving carrier. The laid particles are collected while further particles are deposited on another part of the carrier. The pref. material is an organic dyestuff suitable for use as an electrophotographic receptor, such as a pigment of the anthranthron type. The deposited particles are collected by a scraper blade, a brush, by suction, by stripping, through a blanket or roller. The material is evaporated at a temp. of more than 80 deg.C. and the particle-charged content is cooled at less than 10 deg.C. The chamber section is evacuated to 10-2-102 Torr. The ultrafine particle size is from 10 Angstroms to 1000 Angstroms or several times 20000 Angstroms. ADVANTAGE - The method gives a high prodn. and recovery rate of ultrafine particles, with high grade particle characteristics.