| 摘要 |
PURPOSE:To improve electrifiability of a developer having positive chargeability and to stabilize an image by adding a relatively small amt. of colloidal silicon oxide having negative chargeability to a toner in addition to colloidal silicon oxide having positive chargeability. CONSTITUTION:Colloidal silicon oxides having positive chargeability and negative chargeability are added in combination to a toner and the colloidal silicon oxide is preferably used at about 0.01-1pt. by 100pts. toner. The colloidal silicon oxide having negative chargeability is preferably used at a ratio of about 0.005-0.5pt. by 100pts. toner. The positive chargeable developer having a stable electrifying characteristic is obtd. by adding the colloidal silicon oxides having positive and negative chargeability in combination even in the case of the toner having a relatively wide grain size distribution. The developer is therefore particularly suitable for a developing method in which application of electrification is execute by a toner carrying body (sleeve) having a relatively narrow area. |
