| 摘要 |
PURPOSE:To obtain a toner of superior transfer characteristics, gradation characteristics, developability, etc. by mixing insulation characteristic resin particles contg. magnetic powder and an electrostatic charging controlling agent consisting of insulation characteristic non-magnetic resin particles which are electrostatically charged to the same polarity as that of electrostatic latent images by friction with said particles at specific ratios. CONSTITUTION:Insulation characteristic magnetic resin particles 1 having 1-30mu average grain sizes of insulation characteristic resin particles contg. magnetic powder and insulation characteristic non-magnetic resin particles of <=30mu average grain sizes which are electrostatically charged to the same polarity as that of electrostatic latent images by friction with these (particles prepd. by adding nigrosine dyes, etc. to the resin to provide chargeability to said polarity) as an electrostatic charging controlling agent 2 are mixed and the mixture wherein the agent 2 is contained at 0.5-25wt% of the total weight of both particles is used as a toner. Both particles 1, 2 are provided with >=10<11>OMEGA.cm volume resistivity. The toner which yields always stable and sharp images on plain paper as well irrespectively of atmospheric humidity and which does not require controlling, replenishing, etc. as the agent 2 is consumed together with the particles 1 is obtained. |
