| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electrophotographic toner almost independent of temp. and humidity, having stable triboelectric chargeability and giving stable image quality in any environment by using fine alumina particles made hydrophobic by treatment so that the concn. of methanol to the beginning and end of settling of fine powder is regulated to specified range and difference and specifying the average particle diameter of the particles. SOLUTION: This electrophotographic toner contains toner particles contg. at least a binder resin and a colorant and fine alumina particles made hydrophobic by treatment so that the concn. (A) of methanol at the beginning of settling of fine powder in a method for measuring the hydrophobic degree of fine powder with methanol and the concn. (B) of methanol at the end of settling are regulated to >=20% and 30-90wt.%, respectively, and the difference (B-A) between the concns. A, B is regulated to 0-15%. The average particle diameter of the fine alumina particles is 0.001-0.1μm. The wt. average particle diameter of the toner is 3-9μm.</p> |
