| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a pigment ink retaining fine dispersion of the pigment in fine open-cell foams and excellent in fluidity in an impregnated state and when stamped, by compounding a color pigment, a resin-based dispersant and a specific vehicle. SOLUTION: This pigment ink comprises (A) a color pigment, (B) a resin- based dispersant, and (C) a vehicle comprising (i) a polypropylene glycol having an average molecular weight of 200-800 or (ii) a compound of the formula: R[(OA)mOH]n [A is -CH2CH2- or -CH2CH(CH3)-; R is a residue formed by eliminating OH groups from (n)-valent polyol; (n) is 2-6; (m) is an integer so determined as to give the compound an average molecular weight of 200-1,500]. The component A preferably comprises an organic color pigment satisfying the conditions that the pigment particles in the prepared ink have an average particle diameter of 0.1-0.7μm, and that not less than 90 wt.% of the particles in the prepared ink have particle diameters of 0.03-1.0μm. The component B preferably comprises a polybutyral resin, especially preferably a polyvinyl butyral having an average molecular weight of 25,000-200,000 and a butyralization degree of 58-75 mol%.</p> |
