Non-aqueous pigment ink

Abstract

[Problem to be solved] A non-aqueous pigment ink is disclosed, which can eliminate or reduce striking through while ensuring pigment dispersion stability and ejection stability, and achieve high print density. Also, a non-aqueous inkjet ink is disclosed, which can reduce the time required for warming up the ink while ensuring the pigment dispersion stability and the ejection stability. [Solution] As the first aspect, the non-aqueous pigment ink contains at least a non-aqueous solvent and a pigment that is self-dispersed in the solvent, wherein the self-dispersed pigment is treated with a compound represented by R1—X or R2—Y—R3, where X is any of —SH, —NCO, —NH2 and —NHR (where R is an alkyl group), Y is any of —CO—O—O—CO— and —CO—O—O—, R1, R2 and R3 are alkyl groups with a carbon number of 8-22, the alkyl groups may be linear or branched, and R2 and R3 may be the same with or different from each other. As the second aspect, the non-aqueous inkjet ink contains at least a non-aqueous solvent and a pigment that is self-dispersed in the solvent, wherein a content of a polymer component in the ink is 20 mass % or less relative to the pigment, and the ink has a specific heat of 3.0 J/(g·K) or less.

Dependencies are inferred from the claim text.