| 摘要 |
PURPOSE:To obtain a toner good in dispersibility into a toner binder resin and uniform in the content of fine magnetic particles by using, as a magnetic material, ZnO2-treated fine gamma-iron oxide particles obtained by treating fine alpha-iron oxide particles with a zinc compd. before heat reduction and oxidation treatment of fine alpha-iron oxide particles. CONSTITUTION:As the fine magnetic particles, the ZnO2-treated fine gamma-iron oxide particles obtained by executing the heat treatment of reduction and oxidation of the fine alpha-iron oxide particles after treating them with the zinc compd. are used, that is, the treatment with the zinc compd. lowers the agglomeration force of the agglomerates produced by the heat treatment and permits the heat treated magnetic product to be easily disintegrated into fine particles by ordinary disintegration process. As the treatment with the zinc compd., treatment with zinc hydroxide is typified, and it is executed by the widely known process. |
