| 摘要 |
PURPOSE:To improve durability by thermally oxidizing a mixture of zinc ferrite and Fe3O4 to allow it to have a specified proportion of iron ions and incorporating a magnetic mixture of the obtained magnetic material and alpha-Fe2O3 in a binder resin in a specified amt. CONSTITUTION:Hundred pts.wt. of a binder resin contain 20-100pts.wt. of magnetic mixture of alpha-Fe2O3 and a magnetic material obtained by subjecting a mixture of 7-50mol% zinc ferrite composed of (ZnO)x(FeO)1-xFe2O3 (x=1.00- 0.90) and 93-50mol% Fe3O4 to thermal oxidation treatment to convert the constituent atomic ratio of iron into Fe<3+>/(Fe<3+>+Fe<2+>)>=0.95. The toner using this magnetic material has high lightness as compared with a sepia colored toner using only alpha-Fe2O3 magnetic material, and it can form an image high in density. Said obtained magnetic material is made extremely stable against light and heat by heat oxidizing Fe3O4 and ZnOFe2O3 and blending alpha-Fe2O3 to them. |
