| 摘要 |
PURPOSE:To suppress leaking of charges in a toner image and to prevent decrease in the picture density of printed matter by adding carbon black having specified pH. CONSTITUTION:The carbon black having pH>=7, for example, 'Reagal 330(R)' (pH 8.5) manufactured by Cabbot, Co., 'Laben 2100(R)' (pH 8.9) of Columbian Co., etc., is used and added by 2 - 15 wt.% to the whole toner compsn., and more preferably, by 4 - 10 wt.%. By adding the carbon black having pH>=7, leaking of charge in a toner image can be suppressed, and good picture images with little reduction of picture density can be obtd. even for continuous printing. |
