DE2226478

1389744 Coated particles for electrophotographic developer INTERNATIONAL BUSINESS MACHINES CORP 12 June 1972 [23 June 1971] 27302/72 Heading B2E An electrophotographic developer includes carrier particles and toner particles, the carrier particles each having an interior core portion and a surface layer which comprises at least a major portion of carboxylated polyethylene ionomer. The core may be of sand, glass, metal e.g. iron or steel, magnetic oxides and alloys, e.g. copper-nickel-iron. The coating may be applied to the particulate core material by dipping, spraying, tumbling the core material with a coating solution in a barrel, or by using a fluidised bed. The core material may be pre-treated with a primer, e.g. polyvinyl butyral resin, vinyl chloride terpolymer, polymethyl methacrylate. Other pre-treatments include cleaning, pickling and etching. Pigments and other polymers may be added to the ionomer coating to modify the triboelectric behaviour of the coating.