Superabsorbents Having Superior Permeability and Conveying Properties

• US 20100093949A1
• Filed: 11/07/2007
• Published: 04/15/2010
• Est. Priority Date: 11/10/2006
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Herfert, Norbert, Wendker, Martin, Chiang, Bill, Feise, Hermann Josef, Woodrum, Guy Thomas, Wolf, Hanno Rüdiger
• Granted Patent: US 8,017,549 B2
• Time in Patent Office: Days
• US Class Current: 525/451
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

A superabsorbent having superior permeability and conveying properties comprises a permeability enhancing agent and a cohesion control agent and has a free swell gel bed permeability of at least 15 Darcies and a Hausner ratio in the range of 1.18 to 1.34.

Claims

1. A superabsorbent comprising a permeability enhancing agent and a cohesion control agent and having a free swell gel bed permeability of at least 15 Darcies and a Hausner ratio in the range of 1.18 to 1.34.

2. The superabsorbent of claim 1, in which the permeability enhancing agent is at least one agent selected from the group consisting of particulate inorganic or organic solids, cationic polymers, and water-soluble polyvalent metal salts.

3. The superabsorbent of claim 2, in which the permeability enhancing agent comprises silica and/or aluminium sulphate.

4. The superabsorbent of claim 1, which comprises a permeability enhancing agent in an amount in the range of 0.05 wt.-% to 5 wt.-%, based on the total weight of the superabsorbent.

5. The superabsorbent of claim 1, in which the cohesion control agent is at least one non-aqueous liquid having a viscosity of at least 20 mPas which is selected from the group consisting of alcohols, polyglycols, silicon oils, hydrophilic modified silicon oils, and paraffin oils.

6. The superabsorbent of claim 5, in which the cohesion control agent is polyethylene glycol of an average molecular weight of less than 1,500 g/mol.

7. The superabsorbent of claim 6, which comprises a cohesion control agent in an amount in the range of 100 wt.-ppm to 5,000 wt.-ppm, based on the total weight of material superabsorbent.

8. A process for producing the superabsorbent defined in claim 1, in which 0.05 wt.-% to 5 wt.-% permeability enhancing agent, based on the total weight of the superabsorbent, and 100 wt.-ppm to 5,000 wt.-ppm cohesion control agent, based on the total weight of superabsorbent, are added during the production process.

9. A hygiene article comprising the superabsorbent of claim 1.

10. (canceled)