CARBON BLACK AND RECORDING INK

摘要

PROBLEM TO BE SOLVED: To provide a carbon black improved in dispersion stability in an aq. medium and to provide a recording ink which is prepd. by using the carbon black, has an improved storage stability, and when used in an ink recording apparatus, does not cause nozzle clogging, is stably delivered, and stably gives a good image while hardly causing disorder of image, unevenness in concn., etc. SOLUTION: A recording ink is prepd. by chemically bonding functional groups formed by the decomposition of a free radical generator represented by the formula to the surface of a carbon black and dispersing the carbon black having the functional groups thus bonded to the surface, as the colorant, in an aq. medium. In the formula, A1 , A2 , A3 , and A4 are each independently an optionally susbtd. linear, branched, or cyclic hydrocarbon group).