| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous pigment ink, excellent in low temperature aptitude and storage stability to contribute to power saving and capable of suppressing strike-through and achieving high print density.SOLUTION: A nonaqueous solvent contains ≥50 mass% hydrocarbon-based nonpolar solvent based on the total amount of solvent. A nonaqueous resin is an acrylic polymer having a comb-shaped structure in which an 8-18C alkyl group and a urethane group constitute a side chain to a main chain of a (meth)acrylate. The acrylic polymer is formed by introducing a urethane group to a copolymer of a monomer mixture including an alkyl (meth)acrylate (A) having 8-18C alkyl group, a reactive (meth)acrylate (B) having a functional group that may react with an amino group and a monomer (C) having a &bgr;-diketone group or a &bgr;-keto acid ester group, by reaction of the functional group reacting with an amino group, an amino alcohol and a polyisocyanate compound. The mass ratio of the copolymer part to the urethane group part is specified to be 80:20 to 99:1. |
