| 摘要 |
PURPOSE:To obtain a durable toner having sharp red, yellow, orange, or sepia, and each superior developing performance, transferability, and fiability, by incorporating in a magnetic color toner, gamma-Fe2O3 havng pH, oil absorptivity, and average particle diameter each in a specified range. CONSTITUTION:Water is added to a prescribed amt. or gamma-Fe2O3 and boiled, the supernatant liquid after boiling is adjusted to 4-7 in pH. A prescribed amt. of gamma-Fe2O3 is placed on a glass plate, boiled linseed oil is dropped on it, and the min. amt. of said oil necessary to form a paste is defined as oil absorptivity. A magnetic color toner is obtained by selecting said pH controlled gamma-Fe2O3 having 15-30ml/100g oil absorptivity and 0.1-1mum average particle diameter, and kneading it with a binder resin or immersing it into the resin soln. and spray drying it. gamma-Fe2O3 itself exhibits hues from reddish orange to reddish purple in accordance with its particle diameter, but when needed, dyes or pigments in a series of yellow, orange, red, and sepia may be used. |
