Mechanically strong absorbent non-woven fibrous mats

• US 20060246798A1
• Filed: 05/16/2006
• Published: 11/02/2006
• Est. Priority Date: 04/04/2002
• Status: Active Grant

• Current Assignee: University of Akron
• Original Assignee: University of Akron
• Inventors: Smith, Daniel J., Reneker, Darrell H.
• Granted Patent: US 8,367,570 B2
• Time in Patent Office: Days
• US Class Current: 442/59
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 13/531 having a homogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence
• CPC Class Codes: A61F 2013/530299 being hydrophilic fibres
• CPC Class Codes: A61F 2013/53791 being resilient or elastic
• CPC Class Codes: A61L 15/225 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 26/0052 Mixtures of macromolecular compounds
• CPC Class Codes: B01J 20/261 obtained by reactions only involving carbon to carbon unsaturated bonds macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F
• CPC Class Codes: D01D 5/0038 the fibre formed by solvent evaporation, i.e. dry electro-spinning
• CPC Class Codes: D01F 1/10 Other agents for modifying properties
• CPC Class Codes: D01F 6/88 from mixtures of polycondensation products as major constituent with other polymers or low-molecular-weight compounds
• CPC Class Codes: D01F 6/94 of other polycondensation products
• CPC Class Codes: D04H 1/728 by electro-spinning electro-spinning methods and apparatus D01D5/0007
• CPC Class Codes: D04H 3/02 characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
• CPC Class Codes: Y10T 442/20 Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/602 Nonwoven fabric comprises an elastic strand or fiber material
• CPC Class Codes: Y10T 442/609 Cross-sectional configuration of strand or fiber material is specified
• CPC Class Codes: Y10T 442/614 Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/653 Including particulate material other than fiber
• CPC Class Codes: Y10T 442/659 Including an additional nonwoven fabric
• CPC Class Codes: Y10T 442/666 : Mechanically interengaged by needling or impingement of fluid [e.g., gas or liquid stream, etc.]
• CPC Class Codes: Y10T 442/696 : Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]

Abstract

The present invention is generally directed to a liquid entrapping device having the capacity to absorb liquids. More particularly, the present invention is directed to a liquid entrapping device comprising an absorbent component, hydrophilic elastomeric fibrous component in fluid communication therewith, and optionally an adhesive component. The present invention is also directed to a liquid entrapping device having the capacity to absorb liquids while maintaining a suitable degree of mechanical strength. Furthermore, the present invention is generally directed to methods for making and using the foregoing devices and materials.

Claims

1. A liquid entrapping device comprising:

an absorbent component; and

a hydrophilic elastomeric fibrous component, wherein the absorbent component and the hydrophilic elastomeric fibrous component are in physical proximity thereby resulting in fluid communication, and wherein the absorbent component is more absorbent than the hydrophilic elastomeric fibrous component.

2. The liquid entrapping device of claim 1, wherein the absorbent component is distributed in a manner selected from coated on the surface of the hydrophilic elastomeric fibrous component, embedded in the hydrophilic elastomeric fibrous component, mechanically entangled by the hydrophilic elastomeric fibrous component, and any combination thereof.

3. The liquid entrapping device of claim 1, wherein the absorbent component is selected from polyesters, polyethers, polyester-polyethers, polymers having pendant carboxylic acids or pendant hydroxyls, polysiloxanes, polyacrylamides, kaolins, serpentines, smectites, glauconite, chlorites, vermiculites, attapulgite, sepiolite, allophane and imogolite, sodium polyacrylates, 2-propenamide-co-2-propenoic acid, and any combination thereof.

4. The liquid entrapping device of claim 1, wherein the absorbent component is selected from zein protein, polyester elastomers, polydimethylsiloxane, hydrophilic poly(ether-co-ester) elastomers, silicone-co-polyethyleneglycol elastomers, polyacrylates, thermoplastic polyurethanes, poly(ether-co-urethanes), and any combination thereof.

5. The liquid entrapping device of claim 1, wherein the absorbent component is present in an amount from about 1% (w/w) to about 85% (w/w).

6. The liquid entrapping device of claim 1, wherein the absorbent component is present in an amount from about 5% (w/w) to about 50% (w/w).

7. The liquid entrapping device of claim 1, wherein the absorbent component is present in an amount from about 30% (w/w) to about 50% (w/w).

8. The liquid entrapping device of claim 1, wherein the hydrophilic elastomeric fibrous component is selected from polyurethanes, poly ether-co-urethanes, and any combination thereof.

9. The liquid entrapping device of claim 1, wherein the liquid entrapping device comprises a device selected from a diaper, a tampon, a sanitary napkin, a sanitary wipe, a spill absorbing device, a mop head, and a floor waxing device.

10. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises an absorbency of water from about 400% to about 6000%, wherein absorbency is defined as Q=(W₂−

W₁)/W₁.

11. The liquid entrapping device of claim 10, wherein the liquid entrapping device further comprises an absorbency of water from about 500% to about 5500%.

12. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises an absorbency of urine from about 500% to about 1250%, wherein absorbency is defined as Q=(W₂−

W₁)W₁.

13. The liquid entrapping device of claim 12, wherein the liquid entrapping device further comprises an absorbency of urine from about 500% to about 1000%.

14. The liquid entrapping device of claim 13, wherein the liquid entrapping device further comprises an absorbency of urine from about 600% to about 1000%, wherein absorbency is defined as Q=(W₂−

W₁)/W₁.

15. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises a capacity to absorb about 100% of its equilibrium capacity in about 5 seconds.

16. The liquid entrapping device of claim 15, wherein the liquid entrapping device further comprises a capacity to absorb greater than about 73% of its equilibrium capacity in about 5 seconds.

17. The liquid entrapping device of claim 16, wherein the liquid entrapping device further comprises a capacity to absorb greater than about 75% of its equilibrium capacity in about two minutes.

18. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises a tensile strength from about 0 to about 3.0 MPa when the device is wetted with water.

19. The liquid entrapping device of claim 18, wherein the liquid entrapping device further comprises a tensile strength from about 0.25 to about 3.0 MPa when the device is wetted with water.

20. The liquid entrapping device of claim 19, wherein the liquid entrapping device further comprises a tensile strength from about 0 to about 2.8 MPa when the device is wetted with water.

21. The liquid entrapping device of claim 20, wherein the liquid entrapping device further comprises a tensile strength from about 0.25 to about 2.8 MPa when the device is wetted with water.

22. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises a breaking point at about 850% to about 900% strain.

23. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises a breaking point at about 600% strain.

24. The liquid entrapping device of claim 1, wherein the liquid entrapping device further comprises from about 1% (w/w) to about 5% (w/w) leachable matter.

25. The liquid entrapping device of claim 24, wherein the liquid entrapping device further comprises from about 1.6% (w/w) to about 4.5% (w/w) leachable matter.

26. The liquid entrapping device of claim 25, wherein the liquid entrapping device further comprises from about 1% (w/w) to about 4% (w/w) leachable matter.

27. A process for making a liquid entrapping device comprising:

spinning at least one fiber from a solution comprising a hydrophilogenic elastomerogenic component and an absorbent component, wherein the fiber includes an absorbent component in physical proximity to the hydrophilogenic elastomerogenic component, thereby resulting in fluid communication therewith.

28. The process of claim 27, wherein the product thereof comprises a product selected from a diaper, a bandage, a device for absorbing chemical spills, a device for absorbing biohazardous spills, a mop head, a dish rag, a sanitary wipe, a floor waxing device, a sanitary napkin, a tampon, and a sponge.

29. A process for using a liquid entrapping device made according to claim 28 comprising:

placing a liquid entrapping device in contact with at least one absorbable liquid.

30. A product made according to the process of claim 27.

31. A means for absorbing liquids comprising:

a fluid conductive means; and

an absorbent means, wherein the means for absorbing remains resistant to tensile stress after absorbing one or more liquids.

32. A non-woven fiber assembly comprising one or more fibers wherein the fibers comprise:

an adhesive component;

an elastomeric; and

a hydrophilic component.

33. The non-woven fiber assembly of claim 32, wherein the assembly is capable of adhering to a dry substrate and is not capable of adhering to a wet substrate.

34. The non-woven fiber assembly of claim 32, wherein the assembly forms a component of a medical dressing.

35. The non-woven fiber assembly of claim 32, wherein the adhesive component is selected from homo- and co-polymers of acrylates, silicones, polyvinylpyrrolidones and mixtures thereof.

36. The non-woven fiber assembly of claim 32, wherein the elastomeric component is selected from polyurethanes, polyesters, polyanhydrides, polyamides, polyimides and mixtures and co-polymers thereof.

37. The non-woven fiber assembly of claim 32, wherein the hydrophilic component is selected from linear poly(ethylenimine), grafted cellulosics, poly(ethyleneoxide), poly vinylpyrrolidone, polypropyleneoxides, polyurethanes, poly(hydroxyethylmethacrylate), and mixtures and co-polymers thereof.

38. The non-woven fiber assembly of claim 32, wherein the composition of the one or more fibers at a first surface of the assembly is different from the composition of the one or more fibers at a second surface of the assembly.

39. The non-woven fiber assembly of claim 32, wherein the at least one fiber has a diameter of between about 3 nanometers and about 3000 nanometers.

40. A method of making a non-woven fiber assembly, the method comprising:

providing at least one fiber-forming material; and

forming at least one fiber from the at least one fiber-forming material, wherein the at least one fiber forming material comprises an adhesive component, an elastomeric component, and a hydrophilic component.

41. The method of making a non-woven fiber assembly according to claim 40, wherein the one or more fiber-forming materials is provided in a solvent, and wherein the solvent is selected from alcohols, ethyl acetate, and tetrahydrofuran.

42. The method of making a non-woven fiber assembly according to claim 40, wherein the relative amounts of the adhesive component, the elastomeric component, and the hydrophilic component varies over time, thereby producing a fiber assembly in which the composition of the one or more fibers at a first surface of the dressing differs from the composition of the one or more fibers at a second surface of the dressing.

43. A method of treating a patient comprising:

applying a non-woven fiber assembly to a predetermined area of the patient, wherein the non-woven fiber assembly contains one or more fibers comprising an adhesive component, an elastomeric component, and a hydrophilic component.

44. An apparatus for forming at least one composite fiber, the fiber comprising a hydrophilic component, an elastomeric component and an adhesive component, wherein the apparatus comprises:

a plurality of reservoirs for containing a plurality of fiber-forming materials;

a plurality of valves, each independently in communication with a reservoir; and

a fiber-forming device selected from a spinnerette, a NGJ nozzle, and an electrospinning device, in communication with the valves.

45. The apparatus according to claim 44, additionally comprising a mixing chamber in communication with the valves and the fiber-forming device.

46. The apparatus according to claim 44, wherein the fiber-forming device is an electrospinning device, additionally comprising a power source in electrical communication with the electrospinning device.