| 摘要 |
PURPOSE:To obtain a long-life carrier for development which is spherical, has excellent surface smoothness and high-speed developability, has good resistant to surface staining, obviates the decrease in electric charge quantity during running and prevents the early generation of fogging and machine interior staining by melting a mixture composed of a resin and magnetic powder as essential components then spraying and cooling the melt. CONSTITUTION:The carrier for development is prepd. by mixing and heating a carrier material essentially consisting of the resin and magnetic powder without using a solvent, then directly spraying the material in the molten state and cooling the same by relatively low-temp. air flow. All of general thermoplastic resin groups are usable as the resin which is one of the essential components. All of pulverized particles of ferromagnetic materials which are ordinarily used are usable as the magnetic particles which are the essential component. An electric charge controlling and dispersion improving agent, strength reinforcing agent, coupling agent, etc., may be added in addition to the binder resin and magnetic particles to the inside part of the carrier. The content of the magnetic particles is 30-95pts.wt., more preferably 45-90pts.wt. by the weight of the binder resin. |
