| abstract |
[PROBLEMS] To improve the water resistance of a pigment-containing ink. A water resistance is improved by providing a functional group which binds to a long-chain amine oxide to at least a part of the pigment on the surface of the pigment. The present invention relates to the use of 0 to about 30% by weight of an organic solvent and 0 to about 30% by weight of a water-soluble surfactant, It contains about 0.1-20% by weight of a water-soluble macromolecular chromophore and water, consisting of a vehicle comprising 0% by weight of a zwitterionic surfactant and a pigment having covalently bonded functional groups. The presence of the zwitterionic surfactant improves water resistance and does not negatively affect other properties such as decapping, kogation, and edge sharpness. |