Michael M. Azad, Reidsville, NC; Scott J. Smith, Greensboro, NC; Mark Joy, Reidsville, NC; Geoffrey Wyatt Blake, Kernersville, NC; and Michael S. Jarman, High Point, NC. Assigned to Evonik Corporation, Parsippany, NJ.
Filed: 7/6/12
Issued: 2/24/15
Patented is a superabsorbent polymer containing hydrous kaolin particulate comprising: a) a superabsorbent polymer particulate comprising an intimately admixed blend of from about 95 wt % to about 99.5 wt % of a neutralized superabsorbent polymer hydrogel and from about 5 wt % to about 10 wt % of a hydrous kaolin; wherein the admixed blend is dried and comminuted into superabsorbent polymer particulate wherein the superabsorbent polymer hydrogel is neutralized to from about 50 mol % to about 80 mol %; b) wherein the superabsorbent polymer particulate of a) is surface treated with from about 0.001 wt % to about 5 wt % of a surface crosslinking agent to form a surface crosslinked superabsorbent polymer particulate; and c) wherein the surface crosslinked particulate composition of b) is surface treated with from about 0.01 wt % to about 5 wt % of a multivalent salt to form the superabsorbent polymer containing hydrous kaolin particulate.

Wherein the superabsorbent polymer containing hydrous kaolin particulate has a Centrifuge Retention Capacity of from about 25 g/g to about 40 g/g as measured by the Centrifuge Retention Capacity Test, and wherein, after surface crosslinking, the superabsorbent polymer particulate is dried at a temperature of 195°C for 18 minutes such that the superabsorbent polymer particulate exhibits a Centrifuge Retention Capacity about 3 g/g greater than if the superabsorbent polymer particulate had been dried at 185° C. for 18 minutes.