Absorbent structures with integral layer of superabsorbent polymer particles

• US 6,403,857 B1
• Filed: 12/15/1998
• Issued: 06/11/2002
• Est. Priority Date: 06/08/1998
• Status: Expired due to Fees

• Current Assignee: Buckeye Technologies Incorporated (KOCH Industries Incorporated)
• Original Assignee: Buckeye Technologies Incorporated (KOCH Industries Incorporated)
• Inventors: Baer, Samuel C., Leptick, Steve, Gross, James R., Erspamer, John P.
• Primary Examiner(s): STEPHENS, JACQUELINE F
• Assistant Examiner(s): Shanoski, Paul
• Application Number:
  US09/211,935
• Time in Patent Office: 1,274 Days
• Field of Search: 604/368, 604/385.2, 604/366, 604/385.1, 604/365, 604/367, 604/370, 604/378, 604/375, 604/372, 604/376, 525/330.1, 206/440, 264/342
• US Class Current: 604/365
• CPC Class Codes: A61F 13/534 having an inhomogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence; homogeneous cores with tissue wrapping A61F13/53
• CPC Class Codes: A61F 2013/530547 positioned in a separate layer or layers
• CPC Class Codes: B32B 5/22 characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed layer formed of natural mineral fibres or particles next to a foam layer B32B19/047, next to a layer made of particles B32B19/048, or next to a fibrous or filamentary layer B32B19/06; paper layer or cardboard layer next to a paper layer or cardboard layer B32B29/005, next to a foam layer B32B29/007, next to a fibrous or filamentary layer B32B29/02, or next to a particulate layer B32B29/04
• CPC Class Codes: B32B 5/28 impregnated with or embedded in a plastic substance not used
• CPC Class Codes: D04H 1/407 containing absorbing substances, e.g. activated carbon
• CPC Class Codes: D04H 1/64 the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• CPC Class Codes: D06N 2201/02 Synthetic macromolecular fibres
• CPC Class Codes: D06N 2201/0254 Polyolefin fibres
• CPC Class Codes: D06N 2201/0263 Polyamide fibres
• CPC Class Codes: D06N 2201/042 Cellulose fibres, e.g. cotton
• CPC Class Codes: D06N 2205/023 Emulsion, aqueous dispersion, latex
• CPC Class Codes: D06N 2205/10 Particulate form, e.g. powder, granule
• CPC Class Codes: D06N 2211/24 Personal care
• CPC Class Codes: D06N 3/0034 Polyamide fibres for elastomeric fibres D06N3/0025
• CPC Class Codes: D06N 3/0036 Polyester fibres for elastomeric fibres D06N3/0025
• CPC Class Codes: D06N 3/0038 Polyolefin fibres for elastomeric fibres D06N3/0025
• CPC Class Codes: D06N 7/0055 Particulate material such as cork, rubber particles, reclaimed resin particles, magnetic particles, metal particles, glass beads

Abstract

A discrete superabsorbent layer is adhered to the lower surface of a fibrous absorbent structure using a water-based polymeric binder is disclosed. The advantages are that a superabsorbent roll good can be prepared for later conversion into disposable absorbent products. The use of the water-based polymeric binder prevents particles of superabsorbent from becoming dislodged from the structure during handling and processing.

Claims

1. an absorbent structure suitable for fabrication into disposable personal care articles comprising:

(A) a fibrous absorbent layer; and

(B) a discrete superabsorbent layer which is substantially free of fibers and includes superabsorbent polymer particles localized therein, wherein the discrete superabsorbent layer is integral with and inseparably bonded to the surface of the fibrous absorbent layer by a polymeric binder comprising a natural or synthetic latex having a minimum film-forming temperature at or below room temperature.

2. The absorbent structure of claim 1, wherein said superabsorbent layer is located on the side of the absorbent structure intended to be away from the wearer.

3. The absorbent structure of claim 1, wherein the superabsorbent layer comprises a granular carboxylic crosslinked polyelectrolyte.

4. The absorbent structure of claim 3, wherein the polyelectrolyte is selected from the group consisting of polymers and copolymers of poly(acrylic acid).

5. The absorbent structure of claim 1, further comprising an acquisition layer.

6. The absorbent structure of claim 5, further comprising a distribution layer.

7. The absorbent structure of claim 5, wherein the acquisition layer comprises synthetic fibers.

8. The absorbent structure of claim 7, wherein the synthetic fibers are polyester, polyamide, polyolefin, or a mixture thereof.

9. The absorbent structure of claim 7, wherein the synthetic fibers are bonded with a latex polymeric binder.

10. The absorbent structure of claim 7, wherein the synthetic fibers are bonded with a thermoplastic binder fiber or thermoplastic binder powder.

11. The absorbent structure of claim 10, wherein the synthetic fibers are bonded with a combination of a thermoplastic binder and a latex binder.

12. The absorbent structure of claim 5, wherein the acquisition layer comprises stiffened cellulosic fibers.

13. The absorbent structure of claim 12, wherein the stiffened cellulosic fibers are bonded with a latex polymeric binder.

14. The absorbent structure of claim 12, wherein the stiffened cellulosic fibers are bonded with a thermoplastic binder fiber or thermoplastic binder powder.

15. The absorbent structure of claim 5, wherein the acquisition layer comprises a combination of synthetic fibers and cellulosic fibers bonded with latex, thermally bonded, or bonded with latex and thermally bonded.

16. The absorbent structure of claim 1, wherein the superabsorbent polymer particles are deposited in a discontinuous manner in the superabsorbent layer.

17. A disposable absorbent hygiene article prepared from the absorbent structure of claim 1.

18. The disposable absorbent hygiene article of claim 17, wherein the article is a diaper.

19. The disposable absorbent hygiene article of claim 17, wherein the article is a article is a sanitary napkin.

20. The disposable absorbent hygiene article of claim 17, wherein the article is an adult incontinent product.

21. An absorbent structure suitable for fabrication into disposable personal care articles comprising:

(A) a fibrous absorbent layer; and

(B) a discrete superabsorbent layer which is substantially free of fibers and includes superabsorbent polymer particles localized therein, wherein the discrete superabsorbent layer is integral with and inseparably bonded to the surface of the fibrous absorbent layer by a polymeric binder comprising a mixture of a natural or synthetic latex having a minimum film-forming temperature at or below room temperature, a carboxylic polyelectrolyte, and a crosslinking agent having the property of reacting with carboxyl or carboxylate groups.

22. The absorbent structure of claim 21, wherein said crosslinking agent is a poly-functional crosslinking compound.