| 摘要 |
<p>PURPOSE:To obtain a toner with simplified structure which can be used for high picture quality and rapid process by constituting the magnetic toner of at least a specified binder resin, magnetic material and fluidizing agent. CONSTITUTION:The magnetic toner is used for an electrophotographic process using an electrostatic latent image holding body, developer reservoir and electrode roller. The toner consists of at least a binder resin, magnetic material, and fluidizing agent. The binder resin is a copolymer obtd. by coplymn. of at least monomers expressed by formulae I-IV. The weight average mol.wt. Mw of the binder resin is 100000-500000, and the ratio of the weight average mol.wt. Mw to the number average mol.wt. Mn (Mw/Mn) is 10-50. The BET specific surface area Sa of the magnetic toner before addition of the fluidizing agent and the BET specific surface area Sb after addition are in a relation of Sb/Sa=1.05-1.5. In formulae II-IV, R1 is H or CH3, R2 is an alkyl group of 1-10 carbon number, and R3 is an alkyl group of 16-25 carbon number.</p> |
