| 摘要 |
PROBLEM TO BE SOLVED: To provide a toner having two kinds of titania having different average particle sizes externally added, wherein the add amounts and isolation rates of the titania are evaluated and preferable image quality can be obtained even after long-term use. SOLUTION: In the toner containing two kinds of titania having different average particle sizes as external additives, it is specified that: the first titania has a 10 to 50 nm average particle size; the second titania has a 100 to 200 nm average particle size; the total amount of the first and second titania is 0.2 to 1.5 parts by mass; the addition ratio of the first to second titania is 50/50 to 80/20; and the proportion of the isolated amount of the second titania to the total isolation amount of the first and second titania is 30/100 to 55/100. COPYRIGHT: (C)2006,JPO&NCIPI |
