| 摘要 |
PROBLEM TO BE SOLVED: To provide a negatively charged toner excellent in charge stability in printing on a large number of sheets and so excellent in durability as not to cause unevenness to printed images, which is a negatively charged toner comprising anionic self-water-dispersive polyester resin particles formed by phase inversion emulsification after adding a dispersion stabilizer and an electrolyte. SOLUTION: The negatively charged type toner is obtained by externally addingα-alumina fine particles having a number average primary particle diameter of 100-600 nm and/or hydrophobic silica fine particles having the number average primary particle diameter of 100-600 nm, in combination with hydrophobic silica fine particles having the number average primary particle diameter of 7-16 nm and titanium oxide fine particles having the number average primary particle diameter of 10-30 nm, to anionic self-water-dispersive polyester resin particles formed by phase inversion emulsification after adding a dispersion stabilizer and an electrolyte. COPYRIGHT: (C)2007,JPO&INPIT
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