| 摘要 |
PURPOSE:To obtain an excellent dry process developer by constituting the developer of a toner formed by dispersing fine magnetic particles into a resin incorporated with N into the base material of a resin by amine modification or the like and having an average grain size of a specific value or below and a carrier formed by incorporating a magnetic material into the resin and having the average grain size of a specific value or below. CONSTITUTION:A homopolymer or copolymer or the like such as styrene, methyl (meth)acrylate or the like is incorporated therein with an N element by amine modification, etc. and is further preferably incorporated therein with a positive charge controlling agent such as nigrosine base, etc. Fine ferromagnetic particles are dispersed into such resin to prepare an insulating magnetic toner having <=30mu average grain size. On the other hand, carrier particles dispersed with magnetic particles in a binder resin and having <=100mu average grain size are prepd. The above-described toner on the surface of which pulverous silica powder such as ''Aerosil RA-200H'' or the like is coated and the carrier are mixed. The dry process developer with which the image having high density and excellent contrast without an edge effect even in low to high-temp. and high humidity environment is formed is thus obtd. |
