| 摘要 |
PCT No. PCT/EP94/01321 Sec. 371 Date Dec. 14, 1994 Sec. 102(e) Date Dec. 14, 1994 PCT Filed Apr. 25, 1994 PCT Pub. No. WO94/27192 PCT Pub. Date Nov. 24, 1994A dry toner powder the toner particles of which are triboelectrically negatively charged and are suited for development of an electrostatic charge pattern, wherein said toner particles contain: (1) one or more triboelectrically negatively chargeable thermoplastic resins serving as binder having a volume resistivity of at least 1013 OMEGA -cm, and (2) at least one substance having a volume resistivity lower than the volume resistivity of said binder, and wherein said substance(s) (2) is (are) capable of lowering the volume resistivity of said binder by a factor of at least 3.3 when present in said binder in a concentration of 5% by weight relative to the weight of said binder, and wherein said toner powder containing particles including a mixture of said ingredients (1) and (2) under triboelectric charging conditions is capable of obtaining an absolute median (q/d) charge/diameter value (x) lower than 10 fC/10 mu m but not lower than 1 fC/10 mu m, and said toner powder under the same triboelectric charging conditions but free from said substance(s) (2) then has an absolute median q/d value (x) at least 50% higher than when said substance(s) (2) is (are) present, and wherein the distribution of the charge/diameter values of the individual toner particles is characterized by a coefficient of variation nu </=0.33.
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