Superabsorbent polymer with slow absorption times

US7285614B2 · kind B2 · utility

Assignee

• Stockhausen GmbH · DE

Inventors

• Gerd Jonas · Kempen, DE
• Klaus Pflueger · Eberdingen, DE
• Rüdiger Gerlach · Bad Hersfeld, DE

Key dates

• Filing date: Sep 12, 2003
• Grant date: Oct 23, 2007
• Expiry date: Jul 11, 2024

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61L15/60
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

The invention relates to hydrophilic superabsorbent polymer comprising a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers; b) from about 0.001 to about 5.0 wt. % of internal crosslinking agent; c) from about 0.001 to about 5.0 wt. % of surface crosslinking agent applied to the particle surface; and d) wherein the composition has a degree of neutralization of more than about 20%, and from about 20 mole % to about 75 mole % of the unsaturated acid group containing monomers are neutralized with a first neutralizing agent, and from about 5 mole % to about 40 mole % of the unsaturated acid group containing monomers are neutralized with a second neutralizing agent; at a temperature of about 75° C. or less. Such hydrophilic superabsorbent polymers have an Absorption Time of about 5+10 a2 minutes or greater, where a is the mean particle size of the superabsorbent material in millimeters, a capacity of about 15 g/g or greater, a Drop Penetration Value of about 2 seconds or less, and a floatability of 50% or less.