Absorbent articles comprising fluid acquisition zones with superabsorbent polymers

• US 20050070867A1
• Filed: 09/15/2004
• Published: 03/31/2005
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Schmidt, Mattias, Beruda, Holger, Nakagawa, Yasue, Link, Andrea Lieselotte
• Granted Patent: US 7,847,144 B2
• Time in Patent Office: Days
• US Class Current: 604/367
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents

Abstract

The present invention relates to absorbent articles comprising superabsorbent polymer particles especially suitable for use in the fluid acquisition zone of the absorbent core. The superabsorbent polymer particles are coated with cationic polymers having 1 to 25 mol/kg, referring to the total weight of the cationic polymers, of cationic groups, which can be protonated. The cationic polymers are not substantially covalently bound to the superabsorbent polymer particles.

Claims

1. An absorbent article comprising a substantially liquid pervious topsheet, a substantially liquid impervious backsheet and an absorbent core between said topsheet and said backsheet, wherein said topsheet and said backsheet are at least partially joined together, and wherein said absorbent core comprises at least one fluid acquisition zone wherein said fluid acquisition zone comprises superabsorbent polymer particles, characterized in that:

a) said superabsorbent polymer particles further are surface coated with cationic polymers, wherein said cationic polymers have 1 to 25 mol/kg, referring to the total weight of the cationic polymers, of cationic groups, which can be protonated, wherein said cationic polymers are not substantially covalently bound to said superabsorbent polymer particles, and

b) said superabsorbent polymer particles have a Cylinder Centrifuge Retention Capacity (CCRC) of less than 25 g/g.

3. Absorbent article according to claim 1, wherein said fluid acquisition zone comprises said superabsorbent polymer particles in a concentration of at least 50% by weight of said fluid acquisition zone.

5. Absorbent article according to claim 1, wherein said fluid acquisition zone comprises at least one layer and wherein said superabsorbent particles are comprised by said at least one layer in a concentration of at least 70% by weight of said acquisition layer.

6. Absorbent article according to claim 1, wherein said cationic polymers are substantially non-covalently cross-linked to each other.

7. Absorbent article according to claim 1, wherein said cationic polymers are nitrogen-containing cationic polymers.

8. Absorbent article according to claim 7, wherein said nitrogen-containing cationic polymers are partially hydrolyzed.

9. Absorbent article according to claim 8, wherein said nitrogen-containing cationic polymers are hydrolyzed in the range of 30% to 80%.

10. Absorbent article according to claim 1, wherein said cationic polymers are primary amines, secondary amines or tertiary amines.

11. Absorbent article according to claim 1, wherein said superabsorbent polymer particles have a permeability of at least 400×

10<sup>−

7</sup> cm³ sec/g.

12. Absorbent article according to claim 1, wherein said superabsorbent polymer particles have a Wet Porosity of at least 0.20.

13. Absorbent article according to claim 1, wherein said superabsorbent polymer particles are substantially free of covalent surface cross-links.

2. An absorbent article comprising a substantially liquid pervious topsheet, a substantially liquid impervious backsheet and an absorbent core between said topsheet and said backsheet, wherein said topsheet and said backsheet are at least partially joined together, and wherein said absorbent core comprises at least one fluid acquisition zone wherein said fluid acquisition zone comprises superabsorbent polymer particles, characterized in that:

a) said superabsorbent polymer particles further are surface coated with cationic polymers, wherein said cationic polymers have 1 to 25 mol/kg, referring to the total weight of the cationic polymers, of cationic groups, which can be protonated, wherein said cationic polymers are not substantially covalently bound to said superabsorbent polymer particles, and

b) said fluid acquisition zone comprises said superabsorbent polymer particles in a concentration of at least 50% by weight of said fluid acquisition zone.

4. Absorbent article according to claim 2, wherein said superabsorbent polymer particles have a Cylinder Centrifuge Retention Capacity (CCRC) of less than 25 g/g, preferably less than 20 g/g.