| 摘要 |
PURPOSE:To form a developer of which the carrier hardly sticks to a background part by using particles which are subjected to a heating treatment at the temp. lower than the spheroidization temp. for the same as dry carrier particles. CONSTITUTION:The carrier contg. a binder resin and magnetic powder is heated at the temp. lower than the temp. at which said carrier is subjected to the heating treatment for the purpose of spheroidization. More specifically, the carrier is subjected to the heating treatment at the temp. below the temp. near the m.p. of the binder resin, more preferably at the temp. near the glass transition point of the binder resin. The sticking of the carrier particles to the image background part is obviated when said particles are used as the developer. Polystyrene, etc., are usable for the binder resin of the carrier to be used. The magnetic powder of the carrier to be used is preferably the magnetic powder having 0.1-3mu average grain size, for which magnetite is more preferable. |
