| 摘要 |
PURPOSE:To make improvement in electrostatic charge characteristics and cleaning characteristics at the time of continuous copying of many sheets by specifying the specific surface area actually measured by a BET method and the calculated value of the specific surface area derived from a sphere equiv. particle size to a specific relation. CONSTITUTION:The toner which is essentially composed of a resin and coloring agent and is constituted of a charge control agent and wax at need is so constituted that the ratio of the actually measured value of the specific surface area before mixing of post-additives, such as fluidizing agent and charge control fine particles, and the calculated value derived from the sphere equiv. particle size satisfies equation I. In the formula I, A denotes the specific surface area [m<2>/g] measured by a BET method and B denotes the specific surface area [m<2>/g] calculated from the sphere equiv. particle size measured by a Coulter counter method. The excellent electrostatic charge characteristics and cleaning characteristics are obtd. in this way even at the time of continuous copying of many sheets. |
