| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive charge type magnetic toner excellent not only in offset resistance but in toner properties such as low-temperature fixability, sharp meltability, blocking resistance, charging characteristics and pulverizability and capable of forming good developed images over a prolonged period of time, without using bisphenol A or a derivative thereof as a component of a polyester resin in the toner. SOLUTION: The positive charge type magnetic toner contains a binder resin, a magnetic material and a charge control agent, wherein the binder resin is a linear polyester resin which comprises an acid component consisting of (1) disproportionated rosin and (2) terephthalic acid and/or isophthalic acid and an alcohol component consisting of (3) a glycidyl ester of a tertiary fatty acid and (4) a 2-10C aliphatic diol, and has an acid value of <10 mgKOH/g and a hydroxyl value of≤20 mgKOH/g, and wherein a BET specific surface area of the magnetic material by a nitrogen adsorption method is 3.0-9.0 m<SP>2</SP>/g. COPYRIGHT: (C)2006,JPO&NCIPI
|
