Black toner including a kesinous component for forming an image and imaging process

摘要

A method for forming an image with a copying machine capable of both color copying and black-and-white copying is disclosed, in which a black toner contains at least a colorant and a resinous component having a weight average molecular weight (Mw) of from 25,000 to 80,000 and a number average molecular weight (Mn) of from 2,000 to 8,000, with a Mw/Mn ratio being not less than 10, and having an apparent melt viscosity of 1x104 poise at a temperature between 115 DEG C. and 140 DEG C. as measured by a flow tester method, and the quantity of heat of fixing is varied between a B/W mode and a color mode.