Patent ID: 8361926

Claim:
A polysaccharide superabsorbent polymer particulate comprising: a. a polysaccharide polymer crosslinked with a polyphosphate or polyphosphoric acid as a crosslinking agent to form a polysaccharide polymer gel which is formed into a polysaccharide polymer particulate having a particle size ranging from about 150 μm to about 850 μm; b. a surface crosslinking agent selected from a polyphosphate or polyphosphoric acid forming crosslinks of the surface crosslinking agent and the polysaccharide superabsorbent polymer particulate resulting in a surface crosslinked polysaccharide superabsorbent polymer particulate wherein the level of functional cross links in the vicinity of the surface of the polysaccharide superabsorbent polymer particulate is greater than the level of functional cross links in the interior of the polysaccharide superabsorbent polymer particulate; and c. a post-crosslinking agent selected from a water soluble multivalent metal salt or an acid wherein the water soluble multivalent metal salt includes a metal cation selected from Al, Fe, Zr, Mg, or Zn and the acid is selected from phosphoric acid, acetic acid, lactic acid, citric acid, glyconic acid and gluconic acid wherein the post-crosslinking agent is applied to the surface of the surface crosslinked polysaccharide superabsorbent polymer particulate to form polysaccharide superabsorbent polymer particulate; wherein the polysaccharide superabsorbent polymer particulate has a permeability half life of about 30 days or more.