| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the developing toner by which an excellent picture excellent in environmental stability, fluidity and heat-resistant preservability and without any fogging or void in the solid picture and to furnish a developing toner suitable to form a full-color picture. SOLUTION: This toner contains a colored resin grain contg. a binder resin and a colorant, an anatase-structure titania fine grain made hydrophobic with a hydrophobe and a silica fine grain made hydrophobic with a hydrophobe. In this case, the average primary grain diameter of the silica fine grains is controlled to 5-25nm, the BET specific surface of the silica fine grain made hydrophobic to 80-250m<2> /g and the average primary grain diameter of the titania fine grains to 30-90nm, and the average primary grain diameter of the titania fine grains and the BET specific surface of the grain made hydrophobic are limited to conform to S=1125/D+k. In the formula, S is the BET specific surface (m<2> /g) of the titania fine grain made hydrophobic, and D is the average primary grain diameter of the titania fine grains.</p> |
