PURPOSE: To form a liquid developer compsn. good in dispersibility and electrostatic controllability, and capable of obtaining a natural color copy superior in color reproducibility by using a specified composite azo type pigment as a colorant component and a fine silica powder as a core material.
CONSTITUTION: A composite azo type pigment used here is shown in the formula and obtained by treating a fine silica powder having an average particle diameter up to about 1μm, a surface OH density of ≥ about 0.01/(10nm)2, with an aminosilane coupling agent, such as (C2H5O)3Si-(CH2)3-NH2, and combining a mono- or polyazo dye with the surface of the fine silica powder with a coupling agent. Said composite azo type dye is coated with 20W500wt% (based on the dye) acrylic resin or silicone resin, or the like, and (A) 1pt.wt. of the obtained colorant is mixed with 80W500pts.wt. of an electrically insulating liquid, such as isoparaffin type hydrocarbon, contg. a fixing agent and dispersed uniformly.
NAKATANI KANAME
AZUMAGUCHI TERUAKI
