| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject product excellent in dispersion stability thereof by using a carbon black specifying an oil absorption amount and a BET specific surface area. SOLUTION: This ink jet recording ink contains (A) a carbon black having 800-1000g/100g oil absorption amount based on DIN-ISO-787/5 and 250-500m<2> /g BET specific surface area (suitably 50-1000nm mean particle diameter) in a powdery state, (B) a dispersing agent [suitably a condensation product of β- naphthalenesulfonic acid (salt) with formalin] and (C) a water soluble medium. It is preferable to contain 2-10wt.% component (A), and 0.5-5wt.% component (B) in the ink. As the component (C), water and the water soluble solvent, etc., can be used, but it is preferable to blend 0.1-15wt.% water soluble solvent and 85-95wt.% water. Further, it is preferable to blend 1-5wt.% dispersion improving agent such as an anionic surfactant, etc., together with the component (B). The ink preferably has pH10-12, and 1-10cps viscosity at 25 deg.C. |
