| 摘要 |
PURPOSE:To obtain a developer having long life causing no scattering of toner, no fog, nor decrease of density of developed picture image by sticking fine powder of TiO2 to the surface of toner particles which are charged positively against carrier particles. CONSTITUTION:The title developer is constituted of a material which charges toner particles positively against carrier particles, and fine TiO2 particles are deposited to the surface of the toner particles. Particles having 0.02-0.04mum mean particle size are used for the TiO2 fine particles. The material for the toner is one being charged positively against the carrier before the deposition of TiO2 and being also charged positively against the carrier after the deposition of TiO2. Preferred carrier is one obtd. by dispersing magnetic powder in a resin having 30-80mum particle size. By this constitution, a developer having long life at high temp. and under high humidity is obtd. because of generation of less toner cloud and scarce fog, permitting copy of many sheets of picture image of satisfactory picture quality. |
