LIGHTWEIGHT THIN FLEXIBLE POLYMER COATED GLOVE AND A METHOD THEREFOR

• US 20070204381A1
• Filed: 02/21/2007
• Published: 09/06/2007
• Est. Priority Date: 02/23/2006
• Status: Active Grant

• Current Assignee: Ansell Healthcare Products LLC (Ansell Limited)
• Original Assignee: Ansell Healthcare Products LLC (Ansell Limited)
• Inventors: Narasimhan, Dave, Thompson, Eric, Ghazaly, Hafsah Mohd, Moreland, Jeffrey C.
• Granted Patent: US 7,814,571 B2
• Time in Patent Office: Days
• US Class Current: 2/159
• CPC Class Codes: A41D 19/0065 with a textile layer underneath
• CPC Class Codes: B29C 2059/028 Incorporating particles by impact in the surface, e.g. using fluid jets or explosive forces to implant particles
• CPC Class Codes: B29C 41/14 Dipping a core B29C41/10 takes precedence
• CPC Class Codes: B29C 59/02 by mechanical means, e.g. pressing B29C59/007 takes precedence; embossing expanded porous articles B29C44/5627
• CPC Class Codes: B29L 2031/4864 Gloves

Abstract

A lightweight thin flexible latex glove article having a polymeric latex coating that penetrates the front portion of a knitted liner half way or more through the liner thickness and for at least a portion of the knitted liner, not penetrating the entire thickness. For example, the liner can be knitted using an 18-gauge needle with 70 to 221 denier nylon 66 multi-filament yarn. The polymer latex coating can be 0.75 to 1.25 times the thickness of the knitted liner. Over 30% reduction of glove thickness is achieved resulting in three times greater flexibility. The polymer latex coating may be foamed with 5 to 50 vol % air content. Open celled foamed latex coating may be coated with a dispersion of fluorochemical dispersion to prevent liquid permeation into the glove. The process can include steps to gel the latex emulsion at interstices of the yarn to prevent further penetration of the emulsion into the liner.

Claims

1. A glove, comprising:

a knitted liner having a plurality of stitches made from a yarn having a denier 221 or less; and

a polymeric latex coating adhered to the knitted liner;

the polymeric latex coating penetrating half way or more through a thickness of the knitted liner, and for at least a portion of the knitted liner, the polymeric latex coating does not penetrate the entire thickness of the knitted liner; and

the polymeric latex coating having a thickness in a range of 0.75 to 1.25 times the thickness of the knitted liner.

2. The glove of claim 1, wherein a skin-contacting surface of the knitted liner is substantially free of the polymeric latex coating.

3. The glove of claim 2, wherein the skin-contacting surface of the knitted liner is approximately 75% or more free of the polymeric latex coating.

4. The glove of claim 1, wherein a spacing between the stitches is from approximately one to approximately three times the diameter of the yarn.

5. The glove of claim 1 wherein the yarn has a denier in a range from approximately 70 to approximately 221.

6. The glove of claim 1 wherein the polymeric latex coating has a plurality of cavities.

7. The glove of claim 6 wherein the plurality of cavities are uniformly distributed.

8. The glove of claim 6 wherein the plurality of cavities range have a size from approximately 225 μ

m to approximately 350 μ

m.

9. The glove of claim 1, wherein the stitches are formed by an 18-gauge needle.

10. The glove of claim 1, wherein the glove has a thickness in a range of from approximately 0.60 to approximately 1.14 mm.

11. The glove of claim 10, wherein the thickness is from approximately 0.70 to approximately 0.90 mm.

12. The glove of claim 1, wherein the glove is lightweight.

13. The glove of claim 1, wherein the glove is flexible.

14. The glove of claim 13, wherein the glove has a Clark stiffness number of less than approximately 5 cm.

15. The glove of claim 1, wherein the polymeric latex coating is selected from the group consisting of natural rubber, synthetic polyisoprene, styrene-butadiene, carboxylated or non-carboxylated acrylonitrile-butadiene, polychloroprene, polyacrylic, butyl rubber, a water-based polyester-based polyurethane, a water-based polyether-based polyurethane, or combinations thereof.

16. The glove of claim 15, wherein the polymeric latex coating comprises carboxylated acrylonitrile-butadiene.

17. The glove of claim 1, wherein the yarn comprises nylon 66.

18. The glove of claim 1, wherein the polymeric latex coating is foamed.

19. The glove of claim 18, wherein the polymeric latex coating has an air content in the range 5% to 50% on a volume basis.

20. The glove of claim 19, wherein the polymeric latex coating is a closed cell foam with an air content in the range 5% to 15% on a volume basis.

21. The glove of claim 18, wherein the polymeric latex coating is an open cell foam with an air content in the range 15% to 50% on a volume basis.

22. The glove of claim 1, wherein the polymeric latex coating is coated with an aqueous fluorochemical dispersion coating on the surface distal from the knitted liner adherent surface.

23. The glove of claim 22 wherein the latex coating is unfoamed and the fluorochemical dispersion is applied to the unfoamed latex coating.

24. The glove of claim 22 wherein the latex coating is foamed and the fluorochemical dispersion is applied to the foamed latex coating.

25. The glove of claim 22, wherein the coating of aqueous fluorochemical dispersion has a thickness in a range of from approximately 0.5 to approximately 2 micron.

26. A process for making a lightweight flexible glove, comprising:

a) creating a glove shaped knitted liner knitted with the spacing between yarns being one to three times the diameter of the yarn, the yarn having a denier of approximately 221 or less;

b) placing the knitted liner on a hand shaped ceramic or metallic former;

c) dipping the former and the knitted liner in a coagulant solution;

d) withdrawing the former and the coagulant coated knitted liner;

e) dipping the former and the coagulant coated liner into a tank containing an aqueous polymeric latex emulsion so that the polymeric latex emulsion penetrates half way or more through a thickness of the knitted liner and for at least a portion of the knitter liner, the polymeric latex emulsion not penetrating the entire thickness of the knitted liner;

f) gelling the polymeric latex emulsion on a surface of the coagulant coated knitted liner and at interstices between yarns of the knitted liner, creating blockage to prevent further penetration of polymeric latex emulsion;

g) withdrawing the former and the knitted liner coated with gelled polymer latex coating; and

h) heating the former and the knitted liner coated with gelled polymer latex coating to a temperature to vulcanize the latex coating to form a cured glove with knitted liner adhered to polymer latex cured coating.

27. The process of claim 26, further comprising i) washing the cured glove.

28. The process of claim 26, wherein the step of creating the glove-shaped knitted liner includes using a knitting machine with an 18-gauge needle.

29. The process of claim 26, wherein the coagulant solution is a 2-10 wt % calcium nitrate coagulant solution.

30. The process of claim 26, wherein the aqueous polymeric latex emulsion is stabilized by potassium hydroxide, ammonia or sulfonates.

31. The process of claim 26, wherein the aqueous polymeric latex emulsion has a viscosity in the range of 250-5000 centipoise.

32. The process of claim 26, wherein the dipping depth of the former and the coagulant coated liner into a tank containing the aqueous polymeric latex emulsion is in a range of from approximately 0.2 cm to approximately 5 cm.

33. The process of claim 26, further comprising foaming the aqueous polymeric latex emulsion to produce a foamed polymer latex coating.

34. The process of claim 26, wherein the polymeric latex coating is unfoamed, and further comprising coating an aqueous fluorochemical dispersion coating onto the unfoamed gelled polymeric latex coating.

35. The process of claim 33, further comprising coating an aqueous fluorochemical dispersion coating onto the foamed polymeric latex coating.

36. The process of claim 26, wherein an aqueous fluorochemical composition is applied to the gelled polymeric latex prior to vulcanization.

37. The process of claim 34, wherein the aqueous fluorochemical composition is applied to the gelled foamed polymeric latex prior to vulcanization.

38. The process of claim 26, further comprising applying a coating of a blocking material to the knitted liner to block interstices between yarns of the knitted liner prior to the step of dipping the former and the knitted liner in a coagulant solution.

39. The process of claim 38, wherein the blocking agent is selected from a group consisting PVA, wax, and solvent-based polyurethane.

40. The process of claim 26, wherein the latex layer gelled after step f) is dipped in an aqueous latex emulsion to form a second latex layer and is subjected to fluidized salt bath treatment to create cavities and gel the second layer, which is washed to remove salt, creating the cavities in the second layer of latex.