| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve spectral reflection characteristic, brightness, chromaticness, transparency, light resistance and dispersion by making a composition contain a monoazo-based red pigment and a specific azonaphthoic acid component. SOLUTION: An azo-based red pigment (A) represented by formula I is mixed with one or not less than 2 of naphthoic acid components (B) selected from a compound represented by formula II and calcium, strontium, zinc, barium, manganese and aluminum salts thereof, the amount of the component (B) being 0.5-20 mol.%, preferably 3-15 mol.% of the component (A), to produce a monoazo red pigment composition having an average diameter D50 by an accumulation method of 0.05μm<=D50<=0.20μm (wherein R1, R4 and R5 are each a substituent group selected from OCmH2m+1, CmH2m+1 and H; R2 is a substituent group selected from OCmH2m+1, halogen and H; R3 is a substituent group selected from NO2, halogen, OCmH2m+1 and H; and (m) is 1-10). A magenta color toner having diameter of 1-20μm is obtained by mixing the azo-based red pigment composition with a resin, melting and kneading thereof followed by crushing and classification.</p> |
