Method for producing oxidized carbon black aqueous dispersion, and method for producing oxidized carbon black aqueous dispersion for inkjet ink

Abstract

Provided is a method for easily producing an oxidized carbon black aqueous dispersion that can highly remove multivalent metal ions and exhibit excellent dispersion stability. A method for producing an oxidized carbon black aqueous dispersion by successively performing on an aqueous slurry of oxidized carbon black having one or more anionic functional groups on a surface thereof a neutralization step of mixing an alkali metal hydroxide and performing heating/neutralization in the presence of one or more selected from a water-soluble chelating agent and a salt thereof or after mixing an alkali metal hydroxide and performing heating/neutralization, mixing one or more selected from a water-soluble chelating agent and a salt thereof and a separation and removal step of separating and removing a multivalent metal ion chelate complex from a mixed solution obtained at the neutralization step using a separation membrane.

Dependencies are inferred from the claim text.