OIL-BASED INK-JET RECORDING INK

摘要

An oil-based ink-jet recording ink which has satisfactory pigment dispersion in the beginning of storage and even in long-term storage and has excellent delivery stability which is not influenced by a variation of the ambient temperature during printing. The ink comprises; a pigment; a dispersant comprising a product of the reaction of a polyamine compound with a product of self-condensation of 12-hydroxystearic acid; a saturated hydrocarbon solvent consisting mainly of a liquid paraffin; and a vegetable oil. It is characterized by having a surface tension at 25 DEG C of 26 to 30 dyne/cm and a contact angle as measured at 25 DEG C on a polytetrafluoroethylene plate of 40 to 50 DEG and by satisfying the relationship WHC/WVO > 10 wherein WHC is the weight of the saturated hydrocarbon solvent and WVO is the weight of the vegetable oil.