PURPOSE: To suppress the deterioration of negative chargeability during operation over a long period of time as well as to ensure a sharp distribution of the amt. of electric charges by using polyester resin as resin for fixing and a benzidiene pigment as a colorant and incorporating an electric charge controlling aid having action in reverse polarity to an electric charge controlling agent for negative charging.
CONSTITUTION: Polyester resin is used as resin for fixing, a benzidiene pigment as a colorant and an electric charge controlling aid incompatible with the resin for fixing but dispersible in the resin and having electric charge controlling action in reverse polarity to an electric charge controlling agent for negative charging is incorporated. Since such a positive charge controlling substance as the electric charge controlling aid is combined with the electric charge controlling agent for negative charging, the distribution of the amt. of electric charges on the resulting toner can be made sharp. The benzidiene pigment has superior thermal stability and the sharp distribution can be maintained over a long period of time.
KUBO MASAHIKO
FUJI KAZUO
WATANABE AKIHIRO
KURAMAE YOSHIHISA
