| 摘要 |
PURPOSE:To obtain a coating carrier having good adhesive properties to an iron powder core material and sufficient mechanical strength, by providing a coating layer in which an epoxy resin contg. fine powder of silica is cured by a polyamide resin on the surface of the core material. CONSTITUTION:A carrier for electrophotographic dry type developer is obtained by dipping the iron powder serving as the core material in the resin solution in which silica fine powder, a epoxy resin and a polyamide resin and if necessary, other resin or an additive are dissolved in a solvent such as methyl isobutyl ketone, xyelen, n-butanol, methyl cyclohexanone and methyl ethyl ketone or those mixed solvent. The substance having 90-410m<2>/g surface area by a BET method is preferable as the silica fine powder. The iron powder having 30-200mu particle diameter is preferable as the core material, and the material in which the surfaces of reduced iron powder and atomized iron powder, etc. are subjected to oxidizing treatment is used. |
