| 摘要 |
<p>PURPOSE:To obtain a pigment dispersing agent capable of stably dispersing a pigment in a vehicle in a higher concentration, compared with conventional dispersing agent and useful for offset printing ink by reacting a free carboxyl- containing polyester with a polyalkylene imine at a specific ratio. CONSTITUTION:The objective dispersing agent is obtained by reacting (A) a free carboxyl-containing polyester having 10-16 acid value and preferably obtained by polycondensation through dehydration of 12-hydroxystearic acid with (B) a polyalkylene imine containing 3-6 nitrogen atoms (e.g. diethylenetriamine) in a range of 0.8-1.0 as an equivalent of amino group having active hydrogen of the component B based on 1 equivalent carboxyl group of the component A. Furthermore, the dispersing agent in a concentration of 0.1-100wt.% based on a pigment is blended with the pigment and a resin and an organic solvent as other components to provide the objective offset printing ink composition.</p> |
