Superabsorbent polymer having improved absorption rate and absorption under pressure
AssigneeNalco Chemical Company
InventorsScott J. Smith, Eric J. Lind
Life of this patent
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Abstract
A carboxylic containing superabsorbent polymer having a swell rate of at least 0.3 g./g.sec., a gel strength of about 40,000 to about 150,000 dynes/cm.sup.2, a centrifuge capacity at 30 minutes of about 20 to about 50 g/g, an absorption permeability under pressure at 60 minutes of at least 5 g/g at wherein the ratio of the absorption permeability under pressure at 15 minutes is at least 25% of the absorption permeability under pressure at 60 minutes is disclosed. The superabsorbent polymer is prepared from a solution of carboxylic containing monomers, a cross linking agent, and a blowing agent. The polymer is subsequently treated with a surface crosslinking agent.
Claims12
A carboxylic containing superabsorbent polymer having a swell rate of at least 0.3 g./g.sec., a gel strength of about 40,000 to about 150,000 dynes/cm.sup.2, a centrifuge capacity at 30 minutes of about 20 to about 50 g/g, an absorption permeability under pressure at 60 minutes of at least 5 g/g at wherein the ratio of the absorption permeability under pressure at 15 minutes is at least 25% of the absorption permeability under pressure at 60 minutes.
The carboxylic containing superabsorbent polymer having a swell rate of from about 0.4 to about 1.5 g/g.sec., a gel strength of about 50,000 to about 124,000 dynes/cm.sup.2, a centrifuge capacity at 30 minutes of about 25 to about 45 g/g, an absorption permeability under pressure at 60 minutes of at least 15 g/g wherein the ratio of the absorption permeability under pressure at 15 minutes is at least 40% of the absorption permeability under pressure at 60 minutes.
A carboxylic containing superabsorbent polymer having a swell rate of from about 0.5 to about 1.0 g/g.sec., a gel strength of about 60,000 to about 100,000 dynes/cm.sup.2, a centrifuge capacity at 30 minutes of about 30 to about 40 g/g, an absorption permeability under pressure at 60 minutes of at least 15 g/g wherein the ratio of the absorption permeability under pressure at 15 minutes is at least 50% of the absorption permeability under pressure at 60 minutes.
Dependencies are inferred from the claim text.