| 摘要 |
PROBLEM TO BE SOLVED: To decrease changes in the charge amt. of toner particles depending on the environment and to improve hot offset resistance and fixing performance by incorporating resin particles having different mol.wts. each locally present in toner particles and specifying the amts. of carboxyl groups on each surface. SOLUTION: The amt. A [mol/g] of carboxy groups present on the surface of a low mol.wt. component resin, the amt. B [mol/g] of carboxy groups on the surface of a medium mol.wt. component resin, and the amt. C [mol/g] of carboxy groups on the surface of a high mol.wt. component resin satisfy the relation of formulae. These resin components are incorporated in such a manner that from the surface of the toner particle, the medium mol.wt. component resin, the low mol.wt. component resin and the high mol.wt. component resin are successively oriented in this order. Thereby, a three-layer structure of core/intermediate layer/shell is preferably formed, and the effect of each mol.wt. resin on the fixing performance can be effectively used. The amt. of carboxyl groups on the latex surface is controlled by changing the ratio of monomers having carboxyl groups in the monomers added in the polymn. process. |
