| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a water-base ink which can give a print improved in blotting resistance, water resistance, a printing density, and fretting resistance by using an emulsion of a specified polyester containing an adsorbed water- insoluble or difficultly water-soluble colorant. SOLUTION: One mol of a diol component of the formula (wherein R is an alkylene; and X and Y are each 0 or greater, provided that X+Y is 0-10 on the average) is copolycondensed with 0.05-0.7 mol of trimellitic anhydride and 0.3-1.2 mol of other polycarboxylic acid (derivatives) to obtain a polyester having an acid value of 3-100 mgKOH/g, a glass transition point of 20 deg.C or above, and a number-average molecular weight of 500-100,000. This polyester and a water-insoluble or difficultly water-soluble colorant are added to a solvent, a neutralizing agent is added to the mixture to ionize the carboxyl groups of the polyester, the solvent is distilled off after the addition of water to change the phase into a water phase to thereby obtain a water-base ink containing an emulsion of the polyester having the adsorbed colorant and having a surface tension of (20 deg.C) of 25-50 dyn/cm and a viscosity (20 deg.C) of 0.5-8 cP.</p> |
