| abstract |
(57) [Summary] [PROBLEMS] It is possible to more effectively exhibit required characteristics such as long-term stabilization of charging characteristics, further improvement of durability, further reduction of toner fog, and further improvement of transfer efficiency. Provided are a negatively chargeable toner and an image forming apparatus using the same. SOLUTION: Negatively chargeable silica 1 having a small particle size and a large particle size 3 and 14 adhere to the toner base particles 8a and then to the small externally charged negatively chargeable silica 13 which is the first external additive, the average primary particle diameter is larger than the negatively chargeable silica 13 and the second external additive. The rutile-anatase type titanium oxide 15, which is an additive, is attached to the toner base particles 8a in a form to which it is attached. As a result, the rutile anatase type titanium oxide 15 becomes negatively chargeable silica 13 The toner particles adhere to the toner base particles 8a via the toner particles and are hardly released from the toner base particles 8a. And negatively chargeable silica 1 The toner base particles 8a are negatively charged by 3, 14 and the toner base particles 8a are prevented from being overcharged by the rutile-anatase type titanium oxide 15. |