Color-stable superabsorbent polymer composition

A method of preventing discoloration of superabsorbent polymer particles comprising applying about 0.5 to about 5 mole % of an inorganic reducing agent selected from the group consisting of a hypophosphite salt, a phosphite salt, and mixtures thereof and 0 to about 5 mole % of a water-soluble metal salt selected from the group consisting of an alkali metal salt, an alkaline earth metal salt, a metal salt having a polyvalent cation of valence II, III, or IV, and mixtures thereof to a surface of the particles, to prevent an observable change in color of the particles after six months of storage at 60° C. and 75% humidity, wherein said superabsorbent polymer particles comprise a polymerized α,β-unsaturated carboxylic acid or salt thereof.

A color-stable superabsorbent polymer composition comprising (a) a superabsorbent polymer, (b) about 0.5 to about 5 mole % of an inorganic reducing agent selected from the group consisting of a hypophosphite salt, a phosphite salt, and mixtures thereof, and (c) 0 to about 5 mole % of a water-soluble metal salt selected from the group consisting of an alkali metal salt, an alkaline earth metal salt, a metal salt having a polyvalent cation of valence II, III, and IV, and mixtures thereof, based on the amount of superabsorbent polymer in the composition,

• said superabsorbent polymer selected from the group consisting of a poly(vinylamine), a poly(dialkylaminoalkyl (meth)acrylamide), a polyethylenimine, a poly(allylamine), a poly(allylguanidine), a poly(dimethyldiallylammonium hydroxide), a quaternized polystyrene derivative, a guanidine-modified polystyrene, a quaternized poly((meth)acrylamide), a poly(vinylguanidine), and salts and mixtures thereof.