| abstract |
The present invention provides a water-based ink that is used in ink jet printer printing, with a writing instrument, or the like, that has a low settling rate and for which clogging is not prone to occurring, that can be stored stably for a long period without the viscosity or the carbon black particle diameter increasing, and for which printing with a deep black color and a high print density is possible, and a modified carbon black dispersion used for preparing this water-based ink. The present invention is a liquid having dispersed therein a modified carbon black obtained by subjecting a carbon black raw material powder to oxidation treatment, wherein the modified carbon black has on the surface thereof (a) carboxyl groups, and (b) lactone groups in a molar amount of at least 500 µmol/g relative to the weight of the modified carbon black and a molar ratio of 0.8 to 1.1 times the amount of the carboxyl groups. |