Compositions comprising a thermoplastic component and superabsorbent polymer

• US 6,458,877 B1
• Filed: 08/31/2000
• Issued: 10/01/2002
• Est. Priority Date: 05/07/1998
• Status: Expired due to Term

• Current Assignee: HB Fuller Company
• Original Assignee: Andualem W. Emiru, Leslie J. Clapp, Mark S Kroll, Sharf U. Ahmed
• Inventors: Kroll, Mark S., Clapp, Leslie J., Ahmed, Sharf U., Emiru, Andualem W.
• Primary Examiner(s): Cain, Edward J.
• Assistant Examiner(s): WYROZEBSKI LEE, KATARZYNA I
• Application Number:
  US09/652,470
• Time in Patent Office: 761 Days
• Field of Search: 524/275, 524/500, 524/502, 524/272, 524/916, 428/467, 442/41, 442/84, 442/90
• US Class Current: 524/275
• CPC Class Codes: A61L 15/20 containing organic materials
• CPC Class Codes: A61L 15/225 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 15/24 Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof A61L15/225 takes precedence
• CPC Class Codes: A61L 15/34 Oils, fats, waxes or natural resins A61L15/225 takes precedence
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents
• CPC Class Codes: C08L 101/14 the macromolecular compounds being water soluble or water swellable, e.g. aqueous gels
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: Y10S 524/916 Hydrogel compositions
• CPC Class Codes: Y10T 428/31714 Next to natural gum, natural oil, rosin, lac or wax

Abstract

The present invention relates to a composition comprising a thermoplastic component and at least one superabsorbent polymer, methods of use for such composition, and articles comprising such composition. The composition may be formed into a film layer or applied to an article with various hot melt adhesive application techniques. The composition is useful for a variety of end-uses, particularly for use in disposable absorbent articles such as disposable diapers, feminine napkins and medical dressings.

Claims

1. A thermoplastic composition comprising a thermoplastic component comprising at least one thermoplastic polymer and at least one diluent having polar functionality and at least one superabsorbent polymer.

2. The thermoplastic composition of claim 1 wherein said thermoplastic component is water insensitive.

3. The thermoplastic composition of claim 1 wherein said diluent is a plasticizer.

4. The thermoplastic composition of claim 1 wherein said diluent is a wax.

5. The thermoplastic composition of claim 1 wherein the diluent is present in an amount ranging from about 5 wt-% to about 30 wt-%.

6. The thermoplastic composition of claim 1, wherein said superabsorbent polymer is in the form of particles having a particle size less than about 1000 microns.

7. The thermoplastic composition of claim 1, wherein said superabsorbent polymer is in the form of particles having a particle size less than about 500 microns.

8. The thermoplastic composition of claim 1, wherein said superabsorbent polymer is in the form of particles having a particle size less than about 300 microns.

9. The thermoplastic composition of claim 1, wherein said superabsorbent polymer is in the form of particles having a particle size less than about 200 microns.

10. The thermoplastic composition of claim 1 wherein the superabsorbent polymer is present in an amount ranging from about 30 wt-% to about 60 wt-%.

11. The thermoplastic composition of claim 1 wherein the thermoplastic component comprises at least one polymer selected from the group consisting of block copolymers, amorphous polyolefins, crystalline polyolefins, interpolymers of ethylene and mixtures thereof.

12. The thermoplastic composition of claim 1 wherein the composition gels at a rate substantially equal to or faster than that of the superabsorbent polymer alone.

13. The thermoplastic composition of claim 1 wherein the composition gels in less than 1 hour.

14. The thermoplastic composition of claim 1 wherein the composition gels in less than 30 minutes.

15. The thermoplastic composition of claim 1 wherein the thermoplastic component is a hot melt adhesive.

16. A film layer disposed on a substrate comprising the thermoplastic composition of claim 1.

17. The thermoplastic composition of claim 16 wherein superabsorbent polymer has a particle size equal to or greater than the thickness of the film.

18. A method of making a film comprising the steps of providing a molten mixture of a composition of claim 1 and forming a substantially continuous film from said molten mixture.

19. A method of applying superabsorbent polymer to a substrate comprising the steps of:

a) providing a molten mixture comprising the thermoplastic composition of claim 1; and

b) applying said mixture to a substrate.

20. The method of claim 19 wherein said substrate is selected from the group consisting of, film, paper, nonwoven, tissue, and an absorbent core.

21. A nonwoven web comprising the composition of claim 1.

22. A disposable article comprising a body fluid pervious topsheet and a body fluid impervious backsheet and the composition of claim 1 disposed between said topsheet and backsheet.

23. A thermoplastic composition comprising from about 25 wt-% to about 50 wt-% of a thermoplastic component and about 35 wt-% to about 75 wt-% superabsorbent polymer, said composition having a Brookfield viscosity of less than 30,000 cPs at about 180°

C.

24. The thermoplastic composition of claim 23 wherein the thermoplastic component consists essentially of:

a) about 10 wt-% to about 50 wt-% of at least one water insoluble polymer;

b) 0 wt-% to about 30 wt-% of a plasticizer having polar functionality; and

c) 0 wt-% to about 40 wt-% of a tackifier, wax, non-polar plasticizer, or a mixture thereof.

25. A thermoplastic composition comprising about 25 wt-% to about 75 wt-% of a continuous phase of thermoplastic component and about 25 wt-% to about 75 wt-% of a matrix of superabsorbent polymer wherein the superabsorbent gels in less than 3 hours.

26. A thermoplastic composition comprising:

a thermoplastic component comprising

at least one thermoplastic polymer, and

at least one diluent having polar functionality; and

at least one superabsorbent polymer,

wherein said composition gels at a rate substantially equal to or faster than that of the superabsorbent polymer alone.

27. A film layer disposed on a substrate, said film layer comprising a thermoplastic composition comprising

a thermoplastic component comprising

at least one thermoplastic polymer, and

at least one diluent having polar functionality;

and

at least one superabsorbent polymer having a particle size equal to or greater than the thickness of the film layer.

28. A film layer disposed on a substrate, said film layer comprising a thermoplastic composition comprising

a thermoplastic component comprising

at least one thermoplastic polymer, and

at least one diluent having polar functionality;

and

at least one superabsorbent polymer comprising particles having a particle size equal to or greater than the thickness of the thermoplastic component.

29. A thermoplastic composition comprising

a thermoplastic component comprising

at least one polymer and

at least one diluent having polar functionality;

and

at least one superabsorbent polymer, said composition comprising at least about 5 wt-% said diluent.