| 摘要 |
<p>PURPOSE:To obtain good dispersion stability and a sharp copy with a high coloring degree or image density by using a coloring agent formed by coating the surface of pigment particles with a polyolefin/maleic anhydride copolymer. CONSTITUTION:A hydrous paste of the pigment particle is kneaded with a resin or resin soln. to substitute the water surrounding the surface of the pigment particle with the resin or resin soln. and thereafter, the water and/or solvent is removed by a reduced pressure, drying, etc. so that the pigments are dispersed in the state of primary particles. The polyolefin/maleic anhydride copolymer is extremely effective to improve the dispersibility and coloring power of the pigments. the improvement of the dispersibility is contributed by the affinity of the maleic anhydride component in the copolymer to the pigments and the improvement of the coloring power is contributed by the coloring power of the reactive pigment polymer generated by the reaction of the maleic anhydride component and the basic component in the pigments. The polyolefin/maleic anhydride copolymer is obtainable by a process for producing an ordinary graft copolymer and commercially markated copolymers are also available.</p> |
