Process for the prevention or reduction of discoloration of sodium pyrithione

摘要

Disclosed is a process for producing a zinc pyrithione product having an acceptable white or off-white color and preventing or reducing discoloration of sodium pyrithione solutions by treating said sodium pyrithione solutions (which are precursors to zinc pyrithione) with an effective amount of a selected reducing agent to prevent or reduce the discoloration, said reducing agent selected from the class consisting of alkali metal sulfites, alkali metal bisulfites, hydrazine, and mixtures thereof.