| 摘要 |
PURPOSE:To obtain a toner capable of providing picture having high quality with respect to high density and high resolution for a long period by constituting a toner compsn. by admixing externally added particles having a particle size distribution within a specified range to toner particles having almost completely spherical shape, particle size within a specified range, and a small degree of dispersion. CONSTITUTION:The title toner is constituted of at least toner particles having 0.96-1 the out of roundness(D), 6-11mum volume median diameter(D50) of particles, and 1.55 degree of dispersion of particle size expressed by D25/D75, and externally added particles having 1/200-1/10 average particle size basing on the particle size of the toner particles, wherein a loosened apparent density is regulated to 0.31-0.5g/cc. The out of roundness(D) is expressed by D = sq. rt. r1 X sq. rt. r2/r1, wherein r1 is a major diameter of the particle and r2 is a minor diameter of the particle. Thus, developing effect of a toner can be improved without generating inferior cleaning, and picture images having superior quality with respect to high density, and high resolution can be obtd. for a long time. |
