TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE AND TWO-COMPONENT DEVELOPER

摘要

PROBLEM TO BE SOLVED: To obtain a developer preventing the lowering of image density and the increase of fog by stabilizing the quantity of electric charges on a toner independently of an environmental change over a long period of time and suppressing the charge-up of the toner especially in an environment at low temp. and humidity. SOLUTION: Colored resin particles contg. a colorant and a bonding resin are mixed with fine powder having a smaller average particle diameter than the colored resin particles to obtain the objective toner for developing an electrostatic charge image. The fine powder is obtd. by multistage soap-free polymn. In a stage before the final stage, alkyl acrylate and/or alkyl methacrylate is polymerized or copolymerized. In the final stage, polymerizable carboxylic acid or polymerizable carboxylate is polymerized. The fine powder ensures pH3.6-6.8.