| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve troubles by placing a necessary and sufficient lipophilic layer on the particle surface of an organic pigment, because an offset ink is always brought into contact with water on a printing machine, emulsified in a W/O emulsion state larger or smaller, printed in the emulsified state imperfect in the lipophilicity of the particle surfaces of the pigment and thereby exposed to the troubles caused by the emulsion state. SOLUTION: This organic pigment is obtained by, if necessary, preliminarily treating the particle surface of the organic pigment with a water-soluble silane coupling agent and subsequently treating the preliminarily treated particle surface with the stable O/W emulsion of a resin solution containing a petroleum resin or a modified petroleum resin to place the lipophilic layer of the petroleum resin on the particle surface of the pigment, thus forming the lipophilic pigment particles. The emulsion resistance of the pigment can thereby be improved, and an offset ink using the pigment can markedly reduce the emulsification troubles.</p> |
