COLOR DEVELOPER AND DEVELOPING METHOD

摘要

PURPOSE:To prevent the degradation in image density and the thinning thereof by specifying the grain size distribution and apparent viscosity of toner particles and the contents of negative chargeable hydrophobic inorg. oxide and hydrophilic inorg. oxide. CONSTITUTION:The toner particles having 6 to 10mum and 6.35 to 10.1mum volume average diameter of the toner has the grain size distribution satisfying equation I and the apparent viscosity of the toner is in a range of 10<4> to 5X10<5> poise at 100 deg.C and 5X10<4> to 5X10<6> poise at 90 deg.C. The negative chargeable hydrophobic inorg. oxide A having >=50muc/g absolute value of a triboelectric charge quantity with magnetic particles and 80 to 300m<2>/g specific surface area SA by a BET method is incorporated at (a) weight % of the resin particles into the above- mentioned toner. The hydrophilic inorg. oxide B having >=20muc/g absolute value of a triboelectric charge quantity with the magnetic particles and 30 to 200m<2>/g specific surface area SB by the BET method is incorporated at (b) weight % of the resin particles into the toner. The high image quality is maintained in this way and the good development is executable even in the case of high- density images.