| 摘要 |
<p>PURPOSE: To surely remove an oxidized surface layer by grinding and to form a satisfactory image by using abrasive particles contg. calcium carbonate and having a specified Mohs hardness and a specified average particle diameter on volume basis. CONSTITUTION: Abrasive particles contg. at least calcium carbonate and having a Mohs hardness of >=3.5 and 0.1-10μm average particle diameter on volume basis and a silica additive are added by 0.1-3 pts.wt., in total, to 100 pts.wt. toner particles. The abrasive particles are blended with the silica additive preferably in a weight ratio of 0.1:10 to 3:10. Powdered marble is especially suitable for use as the abrasive particles. Since calcium carbonate as the principal component of the abrasive particles has low volume resistivity and no electrostatic chargeability, when the abrasive particles are used in combination with the silica additive, the quantity of electric charges on the resultant toner is easily controlled and the scattering of the toner is not caused. In the case where the Mohs hardness of the abrasive particles is <3.5, an oxidized surface layer cannot surely be removed by grinding.</p> |
