PURPOSE: To provide the toner having the electric characteristics approximate to the electric characteristics of color toners and to allow the reproduction of bright color images when the images are formed under the same conditions as the conditions for the color toners by incorporating a specific carbon black into a fixing resin.
CONSTITUTION: The carbon black having ≥4% volatile matter, ≥100 structure index and 20 to 35nm average particle size is incorporated into the fixing resin. The electrical conductivity of the carbon black itself increases if the volatile matter of the carbon black is <4%. The toner, then, has an easy tendency to flocculation and the dispersibility into the fixing resin degrades. The toner likewise has the easy tendency to flocculation and the dispersibility into the fixing resin degrades if the structure index is <100. A large amt. of the carbon black is needed to produce a satisfactory black color if the average grain size of the carbon black exceeds 35nm. The toner has the easy tendency to flocculation and the dispersibility into the fixing resin degrades if the average grain size is <20nm.
WATANABE AKIHIRO
NAGAI TAKAFUMI
MARUYAMA HIRONORI
PIGMENTRUSSE-PIGMENT BLACKS\\\9702428=1992