CARBON BLACK DISPERSED LIQUID, MANUFACTURE THEREOF AND INK COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a carbon black suitable for a black pigment which produces no clogging and deposit in an orifice or at an end point of a nozzle and keeps stable ink injection for a long term when used in ink for ink jet or writing by subjecting a dispersion liquid of the oxidization-treated carbon black to a membrane treatment such as ultrafiltration and dialysis and further to an ion exchange resin treatment. SOLUTION: A carbon black dispersion liquid is produced by subjecting a liquid containing a previously oxidization-treated carbon black having not less than 3 equ/m<2> of total acidic group to a membrane treatment and an ion exchange resin treatment. The carbon black is preferably oxidized before use.