| 摘要 |
PROBLEM TO BE SOLVED: To improve jetting stability by imparting an ink for an ink jet recording apparatus, which has a printer head equipped with a nozzle plate having an ink-repelling film formed on the surface thereof, with a dynamic contact angle in backward movement of a specific value or more. SOLUTION: An ink for an ink jet recording apparatus, which has a printer head equipped with a nozzle plate having an ink-repelling film uniformly formed on the surface thereof, has a dynamic contact angle in backward movement of at least 15 deg.. This ink comprises 0.1-10 wt.% of a colorant selected among inorganic and organic pigments having a cumulative average particle size of 20-250 nm and various kinds of dyes, 0.06-3 wt.%, per 1 wt.% of the pigment, of a dispersant, 0.5-40 wt.% of a wetting agent such as diethylene glycol or the like, 0.5-10 wt.% of a low boiling point organic solvent such as ethanol or the like, and the like. As the dispersant is employed a polymer dispersant such as gelatin, a styrene-acrylic acid copolymer or the like, or an anionic, cationic or nonionic surfactant. |
