| 摘要 |
PURPOSE:To obtain a carrier which charges electrostatically always surely a toner, obviates sticking of the toner to the carrier and has excellent durability by combining the carrier formed by using spherical magnetite (Fe3O4) as a core and coating the surface thereof with a resin with the toner. CONSTITUTION:A slurry prepd. by dispersing Fe3O4 fined to about 0.6mu average grain size in an aq. soln. contg. PVA is made into spherical particles of 20-100mu by a spray drying method, etc. The particles are calcined at >=1,000 deg.C in an N2 atmosphere and cooled, then an acrylic resin soln. is spray-coated thereon to manufacture a resin-coated carrier. The carrier is mixed with a toner for magnetic brush development to prepare a developer. The carrier has the specific gravity smaller than the specific gravity of an iron powder carrier, is spherical to permit easy agitation and mixing, contributes to the sure electrostatic charging of the toner and yields always a good image without sticking of the toner to the carrier particles. |
