Patent ID: 7528291

Claim:
A method of manufacturing color-stable superabsorbent polymer particles comprising the steps of: (a) forming a monomer mixture comprising: (i) at least one monomer capable of forming a superabsorbent polymer, (ii) a crosslinking agent, (iii) an initiator system that contains 0 to 300 ppm of a persulfate; (iv) a photoinitiator, and (v) optionally water; (b) polymerizing the monomer and the crosslinking agent in the monomer mixture to form a superabsorbent polymer hydrogel having a water content of 25 wt.% or less; (c) subjecting the superabsorbent polymer hydrogel to a UV radiation of 2000 milliwatt/cm 2 or less; (d) then comminuting the superabsorbent polymer hydrogel to provide superabsorbent hydrogel particles; and (e) drying the superabsorbent polymer hydrogel particles for a sufficient time at a sufficient temperature to provide the color-stable superabsorbent polymer particles.