| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a positive charging toner of non-magnetic single component type which contains a polyester resin an acid value of 2.0 or less and a permittivity of 2.5 or less to serve as a binder resin for a colorant, can give a sufficient positive charging amount required of a toner by including an electric charge controlling agent of positive charging nature, and which can achieve a high image density. SOLUTION: A toner concerned contains a colorant, binder resin, and electric charge controlling agent, and a polyester resin having an acid value of 2.0 or less and a permittivity of 2.5 or less is used as the binder resin for colorant, and the electric charge controlling agent of positive charging nature is added. Accordingly the toner can bear a sufficient amount of positive charging while useful characteristics as binder resin inherent in polyester resin is exhibited against the negative charging nature originating from free carboxyl group existing in polyester resin molecules, and a high image density is achieved.</p> |
