1997 Volume 70 Issue 5 Pages 308-314
Organic pigment molecules with conjugated >C=O and >NH groups, such as quinacridone and indigo, could be dissolved in a polar aprotic solvent, dimethyl sulfoxide, by interaction with a strong base, potassium alkoxide. A direct potentiometric titration in the polar aprotic solvent elucidated that those pigment molecules behaved as acid against the potassium alkoxide and were charged negatively. When an acrylic copolymer having a pendant electrophlic epoxide group was reacted with the pigment molecules, an acrylic polymer having a chromophore as the pendant group was found to be synthesized by the addition reaction.
The adsorption behavior of the above obtained polymer onto the organic pigment having the same chromophore structure was investigated. The polymer with a chromophore showed higher adsorption amount and affinity to the pigment than the polymer without chromophore. The chromophore pendant polymer seemed to be useful as a novel pigment dispersant.
