| 摘要 |
<p>PROBLEM TO BE SOLVED: To stabilize antistatic characteristics such as frictional electricity, etc., and to improve environmental dependence, fluidity and caking resistance by including a specific amount of needle rutile titanium dioxide, forming an indeterminate particle structure and specifying a specific surface area. SOLUTION: This ultrafine particle titanium dioxide for an additive comprises 1-6 wt.% needle rutile titanium dioxide to form an indeterminate particle structure of agglomerated primary particles having 0.005-0.01μm particle diameters and to give 150-210 m2/g specific surface area and is useful for providing a toner having excellent characteristics. The ultrafine particles titanium dioxide has its particle surface coated with a layer containing Al, Si, Ti, Zr, Sn, etc., to adjust an amount of static electrification and is further treated with a silane coupling agent to improve dispersibility. The rutile type titanium dioxide is obtained by adding 2-10 wt.% colloidal sol seed of a rutile crystal structure to a hydrolyzate mother liquor, hydrolyzing it, deflocculating obtained metatitanic acid, washing, drying and baking.</p> |
