| 摘要 |
PURPOSE:To obtain a carrier for development which has excellent surface smoothness and high-speed developability, has good resistance to surface staining and prevents the decrease in electric charge during running and the early generation of fogging by melting a mixture composed of a resin and magnetic powder as essential components then spraying and cooling the melt so that the magnetic powder is dispersed and incorporated into the prepd. resin. CONSTITUTION:A carrier material essentially consisting of the resin and magnetic powder is mixed and heated; thereafter, the material is directly sprayed in the molten state and is cooled by relatively low-temp. air flow to obtain the carrier for development in which the magnetic powder is dispersed and incorporated. All of general thermoplastic resins 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. The content of the magnetic particles is 30-95pts. wt., more preferably 45-90pts.wt. by the weight of the binder resin. An electric charge controlling and dispersion improving agents, strength reinforcing agent, coupling agent, etc., may be added in addition to the binder resin and pulverized magnetic particles to the carrier. |
