Fluid handling layers made from foam and absorbent articles containing same

• US 6,852,905 B2
• Filed: 11/15/2001
• Issued: 02/08/2005
• Est. Priority Date: 11/15/2001
• Status: Expired due to Term

• Current Assignee: Paragon Trade Brands, LLC
• Original Assignee: Paragon Trade Brands Inc. (Johnson Controls International plc)
• Inventors: Baker, Andrew
• Primary Examiner(s): Schwartz, Larry I.
• Assistant Examiner(s): ANDERSON, CATHARINE L
• Application Number:
  US09/987,762
• Publication Number:
  US 20030093050A1
• Time in Patent Office: 1,181 Days
• Field of Search: 604/369, 604/378
• US Class Current: 604/369
• CPC Class Codes: A61F 13/15203 Properties of the article, e.g. stiffness or absorbency chemical aspects A61L15/00
• CPC Class Codes: A61F 13/53747 the layer is facing the topsheet layer is part of the topsheet A61F13/511
• CPC Class Codes: A61F 2013/530802 characterized by the foam or sponge other than superabsorbent A61F2013/530649 takes precedence
• CPC Class Codes: A61L 15/26 Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof A61L15/225 takes precedence
• CPC Class Codes: A61L 15/425 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 75/04 Polyurethanes

Abstract

The Invention relates to absorbent articles, such as diapers, incontinence products, training pants, sanitary napkins, and the like, providing superior strikethrough and rewet characteristics, and methods of preparing the absorbent articles. The absorbent articles comprise at least a topsheet, backsheet, absorbent core, and fluid handling layer, and the article has a third insult Strikethrough of less than about 45 seconds, and a third insult Rewet of less than about 35 grams.

Claims

1. An absorbent article comprising:

a substantially impermeable backsheet;

a permeable topsheet;

an absorbent core disposed between the substantially impermeable backsheet and permeable topsheet; and

a foam fluid handling layer,

whereby the foam fluid handling layer is disposed between the permeable topsheet and the absorbent core, and

wherein the absorbent article has a third insult Strikethrough of less than about 45 seconds, and a third insult Rewet of less than about 35 grams; and

wherein the fluid handling layer is comprised of a polyurethane foam made from at least an aliphatic isocyanate.

2. The absorbent article of claim 1, wherein the absorbent article is selected from the group consisting of a diaper, an incontinent brief, a training pant, a diaper holder, a diaper liner, a sanitary napkin, a hygienic garment, a swimming diaper, or combinations thereof.

3. The absorbent article of claim 1, wherein the third insult Strikethrough is less than about 40 seconds.

4. The absorbent article of claim 3, wherein the third insult Strikethrough is less than about 35 seconds.

5. The absorbent article of claim 1, wherein the third insult Rewet is less than about 30 grams.

6. The absorbent article of claim 5, wherein the third insult Rewet is less than about 25 grams.

7. The absorbent article of claim 1, wherein the aliphatic isocyanate is at least one isocyanate selected from the group consisting of hexamethylene diisocyanate, hexamethylene triisocyanate, bicycloheptane triisocyanate, undecanetriisocyanate, lysine ester triisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, dimethylcyclohexane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, their dimers, their trimers, and mixtures thereof.

8. The absorbent article of claim 7, wherein the aliphatic isocyanate is hexamethylene diisocyanate.

9. The absorbent article of claim 1, wherein the aliphatic isocyanate is reacted with a polyester alcohol.

10. The absorbent article of claim 9, wherein the polyester alcohol is a polyetherol having a molecular weight within the range of from about 1,000 to about 6,000 g/mol, and a functionality of from about 2 to about 8.

11. The absorbent article of claim 9, wherein the polyurethane is complexed with a complexing agent selected from the group consisting of ethylenimine, polyethylenimine, polyvinylamine, carboxy-methylated polyethylenimines, phosphono-methylated polyethylenimines, quaternized polyethylenimines and/or dithiocarbamitized polyethylenimines.

12. The absorbent article of claim 11, wherein the complexing agent is a polyethylenimine having a molecular weight within the range of from about 500 to about 30,000 g/mol.

13. The absorbent article of claim 9, wherein the polyester alcohol is selected from the group consisting of polyether polyols, ethylene glycol, propylene glycol, glycerol, hexanetriol, triethanolamine, ethylene oxide, propylene oxide, butylene oxide, polytetramethylene ether glycol, lactone-type polyester polyols, polyol compounds obtained by condensing a dihydric or trihydric alcohol with s hydroxycarboxylic acid, polyol compounds obtained by condensing dicarboxylic acids with diols, condensed polyester polyols obtained by adding acid anhydrides with diols, and mixtures thereof.

14. The absorbent article of claim 9, wherein the aliphatic isocyanate and polyester alcohol are reacted in the presence of a catalyst selected from the group consisting of tin diacetate, tin dioctoate, dialkyltin dilaurate, triethylamine, pentamethyldiethylenetriamine, bis(dimethylaminoethyl) ether, 1,2-dimethylimidazole, dimethylcyclohexylamine, dimethylbenzylamine, triethylenediamine, and mixtures thereof.

15. The absorbent article as claimed in claim 1, wherein the foam has a sink time of more than 20 seconds.

16. The absorbent article as claimed in claim 1, wherein the foam has a liquid up-take of from about 10 to about 30 grams.

17. The absorbent article as claimed in claim 1, wherein the foam has a tensile strength of from about 25 to about 100 kPa.

18. The absorbent article as claimed in claim 1, wherein the foam has a cell size from the top surface of the foam (cell size A) of from about 400 to about 1,000 μ

m.

19. The absorbent article as claimed in claim 1, wherein the foam has a cell size from the side surface of the foam (cell size B) of from about 300 to about 550 μ

m.

20. The absorbent article as claimed in claim 1, wherein the foam has a hole diameter within the range of from about 125 to about 400 μ

m.

21. The absorbent article as claimed in claim 1, wherein the foam as an absolute value change in basis weight from dry basis weight to wet basis weight of less than about 20 g/m².

22. An absorbent garment comprising:

a substantially impermeable backsheet and a permeable topsheet defining a front waist portion and a rear waist portion, said front waist portion and said rear waist portion cooperating to form a waist opening;

a crotch region formed between the front waist portion and the rear waist portion;

a pair of leg openings on opposed sides of the crotch region;

an absorbent core;

disposed between the substantially impermeable backsheet and the permeable topsheet at the crotch region; and

a foam fluid handling layer comprising a foam made from at least an aliphatic isocyanate,

whereby the foam fluid handling layer is disposed between the permeable topsheet and the absorbent core, and

wherein the absorbent article has a third insult Strikethrough of less than about 45 seconds, and a third insult Rewet of less than about 35 grams.

23. The absorbent article of claim 22, wherein the foam fluid handling layer is a polyurethane foam fluid handling layer made from at least an aliphatic isocyanate.

24. The absorbent article of claim 22, wherein the foam fluid handling layer is made from at least one polymer selected from the group consisting of a polyurethane, a polyethylene, a polypropylene, a polyacrylic, a polyamide, a polyvinyl chloride, an epoxy, a polystyrene, a melamine-formaldehyde polymer, and combinations thereof.

25. The absorbent article of claim 22, wherein the foam fluid handling layer is comprised of at least a polyurethane polymer or a melamine-formaldehyde polymer.

26. The absorbent article of claim 24, wherein the polymer is a melamine-formaldehyde polymer.

27. The absorbent article of claim 22, wherein the foam has a density within the range of from about 20 to about 700 grams/liter.

28. The absorbent article of claim 22, wherein the foam additionally comprises a stabilizing agent.

29. The absorbent article of claim 22, wherein the foam additionally comprises at least one additive selected from the group consisting of surfactants, fillers, additives, or combinations thereof.

30. The absorbent article of claim 29, wherein the additive is selected from the group consisting of a flame retardant, a reinforcing agent, an auxiliary blowing agent, a medicament, a fragrance, a colorant, a cleaner, an abrasive, and combinations thereof.

31. The absorbent article of claim 22, wherein the absorbent article is selected from the group consisting of a diaper, an incontinent brief, a training pant, a diaper holder, a diaper liner, a sanitary napkin, a hygienic garment, a swimming diaper, or combinations thereof.

32. The absorbent article of claim 22, wherein the third insult Strikethrough is less than about 40 seconds.

33. The absorbent article of claim 32, wherein the third insult Strikethrough is less than about 35 seconds.

34. The absorbent article of claim 22, wherein the third insult Rewet is less than about 30 grams.

35. The absorbent article of claim 34, wherein the third insult Rewet is less than about 25 grams.

36. The absorbent article of claim 23, wherein the aliphatic isocyanate is at least one isocyanate selected from the group consisting of hexamethylene diisocyanate, hexamethylene triisocyanate, bicycloheptane triisocyanate, undecanetriisocyanate, lysine ester triisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, dimethylcyclohexane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, their dimers, their trimers, and mixtures thereof.

37. The absorbent article of claim 36, wherein the aliphatic isocyanate is hexamethylene diisocyanate.

38. The absorbent article of claim 23, wherein the aliphatic isocyanate is reacted with a polyester alcohol.

39. The absorbent article of claim 38, wherein the polyester alcohol is a polyetherol having a molecular weight within the range of from about 1,000 to about 6,000 g/mol, and a functionality of from about 2 to about 8.

40. The absorbent article of claim 38, wherein the polyurethane is complexed with a complexing agent selected from the group consisting of ethylenimine, polyethylenimine, polyvinylamine, carboxy-methylated polyethylenimines, phosphono-methylated polyethylenimines, quaternized polyethylenimines and/or dithiocarbamitized polyethylenimines.

41. The absorbent article of claim 40, wherein the complexing agent is a polyethylenimine having a molecular weight within the range of from about 500 to about 30,000 g/mol.

42. The absorbent article of claim 38, wherein the polyester alcohol is selected from the group consisting of polyether polyols, ethylene glycol, propylene glycol, glycerol, hexanetriol, triethanolamine, ethylene oxide, propylene oxide, butylene oxide, polytetramethylene ether glycol, lactone-type polyester polyols, polyol compounds obtained by condensing a dihydric or trihydric alcohol with s hydroxycarboxylic acid, polyol compounds obtained by condensing dicarboxylic acids with diols, condensed polyester polyols obtained by adding acid anhydrides with diols, and mixtures thereof.

43. The absorbent article of claim 38, wherein the aliphatic isocyanate and polyester alcohol are reacted in the presence of a catalyst selected from the group consisting of tin diacetate, tin dioctoate, dialkyltin dilaurate, triethylamine, pentamethyldiethylenetriamine, bis(dimethylaminoethyl) ether, 1,2-dimethylimidazole, dimethylcyclohexylamine, dimethylbenzylamine, triethylenediamine, and mixtures thereof.

44. The absorbent article as claimed in claim 23, wherein the foam has a sink time of more than 20 seconds.

45. The absorbent article as claimed in claim 23, wherein the foam has a liquid up-take of from about 10 to about 30 grams.

46. The absorbent article as claimed in claim 23, wherein the foam has a tensile strength of from about 25 to about 100 kPa.

47. The absorbent article as claimed in claim 23, wherein the foam has a cell size from the top surface of the foam (cell size A) of from about 400 to about 1,000 μ

m.

48. The absorbent article as claimed in claim 23, wherein the foam has a cell size from the side surface of the foam (cell size B) of from about 300 to about 550 μ

m.

49. The absorbent article as claimed in claim 23, wherein the foam has a hole diameter within the range of from about 125 to about 400 μ

m.

50. The absorbent article as claimed in claim 23, wherein the foam as an absolute value change in basis weight from dry basis weight to wet basis weight of less than about 20 g/m².

51. A method of preparing an absorbent article comprising:

providing a topsheet material and a backsheet material;

disposing between the topsheet and backsheet materials an absorbent core;

disposing between the topsheet and the absorbent core a foam fluid transport layer,

whereby the absorbent article has a third insult Strikethrough of less than about 45 seconds, and a third insult Rewet of less than about 35 grams; and

wherein the fluid handling layer is a polyurethane foam fluid handling layer made from at least an aliphatic isocyanate.

52. The method of claim 51, wherein the absorbent article is selected from the group consisting of a diaper, an incontinent brief, a training pant, a diaper holder, a diaper liner, a sanitary napkin, a hygienic garment, a swimming diaper, or combinations thereof.

53. The method of claim 51, wherein the third insult Strikethrough is less than about 40 seconds.

54. The method of claim 53, wherein the third insult Strikethrough is less than about 35 seconds.

55. The method of claim 51, wherein the third insult Rewet is less than about 30 grams.

56. The method of claim 55, wherein the third insult Rewet is less than about 25 grams.

57. The method of claim 51, wherein the aliphatic isocyanate is at least one isocyanate selected from the group consisting of hexamethylene diisocyanate, hexamethylene triisocyanate, bicycloheptane triisocyanate, undecanetriisocyanate, lysine ester triisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, dimethylcyclohexane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, their dimers, their trimers, and mixtures thereof.

58. The method of claim 57, wherein the aliphatic isocyanate is hexamethylene diisocyanate.

59. The method of claim 51, wherein the aliphatic isocyanate is reacted with a polyester alcohol.

60. The method of claim 59, wherein the polyester alcohol is a polyetherol having a molecular weight within the range of from about 1,000 to about 6,000 g/mol, and a functionality of from about 2 to about 8.

61. The method of claim 59, wherein the polyurethane is complexed with a complexing agent selected from the group consisting of ethylenimine, polyethylenimine, polyvinylamine, carboxy-methylated polyethylenimines, phosphono-methylated polyethylenimines, quaternized polyethylenimines and/or dithiocarbamitized polyethylenimines.

62. The method of claim 61, wherein the complexing agent is a polyethylenimine having a molecular weight within the range of from about 500 to about 30,000 g/mol.

63. The absorbent article of claim 59, wherein the polyester alcohol is selected from the group consisting of polyether polyols, ethylene glycol, propylene glycol, glycerol, hexanetriol, triethanolamine, ethylene oxide, propylene oxide, butylene oxide, polytetramethylene ether glycol, lactone-type polyester polyols, polyol compounds obtained by condensing a dihydric or trihydric alcohol with s hydroxycarboxylic acid, polyol compounds obtained by condensing dicarboxylic acids with diols, condensed polyester polyols obtained by adding acid anhydrides with diols, and mixtures thereof.

64. The method of claim 59, wherein the aliphatic isocyanate and polyester alcohol are reacted in the presence of a catalyst selected from the group consisting of tin diacetate, tin dioctoate, dialkyltin dilaurate, triethylamine, pentamethyldiethylenetriamine, bis(dimethylaminoethyl) ether, 1,2-dimethylimidazole, dimethylcyclohexylamine, dimethylbenzylamine, triethylenediamine, and mixtures thereof.

65. The method as claimed in claim 51, wherein the foam has a sink time of more than 20 seconds.

66. The method as claimed in claim 51, wherein the foam has a liquid up-take of from about 10 to about 30 grams.

67. The method as claimed in claim 51, wherein the foam has a tensile strength of from about 25 to about 100 kPa.

68. The method as claimed in claim 51, wherein the foam has a cell size from the top surface of the foam (cell size A) of from about 400 to about 1,000 μ

m.

69. The method as claimed in claim 51, wherein the foam has a cell size from the side surface of the foam (cell size B) of from about 300 to about 550 μ

m.

70. The method as claimed in claim 51, wherein the foam has a hole diameter within the range of from about 125 to about 400 μ

m.

71. The method as claimed in claim 51, wherein the foam as an absolute value change in basis weight from dry basis weight to wet basis weight of less than about 20 g/m².