Absorbent members comprising a high surface area material for absorbing body liquids

• US 6,372,953 B1
• Filed: 03/01/1999
• Issued: 04/16/2002
• Est. Priority Date: 01/10/1995
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Ashraf, Arman, Horney, James C., Desmarais, Thomas A., Schmidt, Mattias, Young, Gerald A., Palumbo, Gianfranco, Goldman, Stephen A.
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): PLUCINSKI, JAMISUE A
• Application Number:
  US09/258,889
• Time in Patent Office: 1,142 Days
• Field of Search: 604/378, 604/369, 604/368, 604/385.01, 604/367, 442/347, 442/348, 428/299.4, 428/299.7
• US Class Current: 604/369
• CPC Class Codes: A43B 1/0036 with fluorescent or phosphorescent parts
• CPC Class Codes: A43B 17/102 Moisture absorbing socks; Moisture dissipating socks
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 2013/530328 being mineral fibres, e.g. glass
• 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 15/425 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents
• CPC Class Codes: C08F 2/32 Polymerisation in water-in-oil emulsions

Abstract

Described are absorbent members useful in the containment of body liquids such as urine. These absorbent members comprise at least one osmotic absorbent (preferably a hydrogel-forming absorbent polymer) and a high surface area material, and have a high capillary suction capacity. For purposes of the present disclosure, capillary suction capacity is measured in terms of the member'"'"'s ability to uptake liquid at high capillary heights, which are generally encountered when the member is positioned in an absorbent article. In particular, capillary suction capacity is measured in terms of a member'"'"'s capillary sorption absorbent capacity, which is measured in accordance with the Capillary Sorption method described in the Test Methods section.

Claims

1. A high capillary suction storage absorbent member comprising an osmotic absorbent and a high surface area open-celled, hydrophilic polymeric foam, wherein the polymeric foam has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g.

2. The storage absorbent member of claim 1 wherein the high surface area polymeric foam comprises high surface area polymeric foam particles having a dry particle size of less than about 1000 microns.

3. The storage absorbent member of claim 1 wherein the high surface area polymeric foam comprises high surface area polymeric foam particles having a mass median dry particle size of between about 50 microns and about 600 microns.

4. An absorbent article comprising the storage absorbent member of claim 1.

5. The storage absorbent member of claim 1 wherein the high surface area polymeric foam is in particulate form.

6. The storage absorbent member of claim 5 wherein the high surface area polymeric foam particles have been unidirectionally dewatered.

7. The storage absorbent member of claim 5 wherein the member comprises from about 1 to about 98%, by total weight of the member, of the high surface area polymeric foam.

8. The storage absorbent member of claim 7 wherein the member comprises from about 15 to about 85%, by total weight of the member, of the high surface area polymeric foam.

9. The storage absorbent member of claim 8 wherein the member comprises from about 20 to about 50%, by total weight of the member, of the high surface area polymeric foam.

10. The storage absorbent member of claim 1 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

11. The storage absorbent member of claim 10, wherein the high surface area polymeric foam is prepared by polymerizing a high internal phase water-in-oil emulsion and the polymeric foam has:

a) a capillary suction specific surface area of at least about 3 m²/g;

b) a resistance to compression deflection (RTCD) such that a confining pressure of 5.1 kPa produces a strain of from about 2 to about 10% compression of the polymeric foam when it has been saturated to its free absorbent capacity with synthetic urine having a surface tension of 65±

5 dynes/cm; and

c) an equilibrium 90% vertical hang sorption height (VHSH) of at least about 60 cm.

12. The storage absorbent member of claim 10, wherein the high surface area polymeric foam exhibits a resistance to compression deflection (RTCD) such that a confining pressure of 5.1 kPa produces a strain of from about 2 to about 10% compression of the polymeric foam when it has been saturated to its free absorbent capacity with synthetic urine having a surface tension of 65±

5 dynes/cm.

13. The storage absorbent member of claim 12, wherein the high surface area polymeric foam exhibits a resistance to compression deflection (RTCD) such that a confining pressure of 5.1 kPa produces a strain of from about 2 to about 5% compression of the polymeric foam when it has been saturated to its free absorbent capacity with synthetic urine having a surface tension of 65±

5 dynes/cm.

14. The storage absorbent member of claim 10, wherein the high surface area polymeric foam has an equilibrium 90% vertical hang sorption height (VHSH) of at least about 60 cm.

15. The storage absorbent member of claim 14, wherein the high surface area polymeric foam has an equilibrium 90% vertical hang sorption height of from about 60 to about 90 cm.

16. The storage absorbent member of claim 10, wherein the high surface area polymeric foam has a capillary suction specific surface area of at least about 3 m²/g.

17. The storage absorbent member of claim 16, wherein the high surface area polymeric foam has a capillary suction specific surface area of from about 3 m²/g to about 30 m²/g.

18. The storage absorbent member of claim 17, wherein the high surface area polymeric foam has a capillary suction specific surface area of from about 4 m²/g to about 17 m²/g.

19. A high capillary suction storage absorbent member comprising discrete osmotic absorbents and discrete high surface area hydrophilic fibers, wherein the high surface area fibers have one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g; and

the storage absorbent member comprises at least about 25%, by total weight of the member, of the high surface area fibers.

20. An absorbent article comprising the storage absorbent member of claim 19.

21. The storage absorbent member of claim 19 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

22. The storage absorbent member of claim 21 wherein the member comprises at least about 30%, by total weight of the member, of the high surface area fibers.

23. The storage absorbent member of claim 21 wherein the high surface area fibers are selected from the group consisting of glass microfibers, fibrillated cellulose acetate fibers, and mixtures thereof.

24. A high capillary suction storage absorbent member comprising osmotic absorbents and a discrete high surface area material, wherein the high surface area material has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g; and

the storage absorbent member has one or more of the following;

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 4 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 4 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 3 g/g.

25. The storage absorbent member of claim 24 having a capillary sorption absorbent capacity at a height of 0 cm of at least about 15 g/g.

26. An absorbent article comprising the storage absorbent member of claim 24.

27. The storage absorbent member of claim 30 wherein the high surface area material is selected from the group consisting of high surface area fibers, a high surface area open-celled, hydrophilic polymeric foam, and mixtures thereof.

28. The absorbent member of claim 27 wherein the high surface area material is a high surface area open-celled, hydrophilic polymeric foam having one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g.

29. The absorbent member of claim 27 wherein the high surface area material comprises high surface area fibers having one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g.

30. The storage absorbent member of claim 24 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

31. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 100 cm of from about 4 g/g to about 30 g/g.

32. The storage absorbent member of claim 31 having a capillary sorption absorbent capacity at a height of 100 cm of from about 8 g/g to about 20 g/g.

33. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 140 cm of from about 4 g/g to about 28 g/g.

34. The storage absorbent member of claim 33 having a capillary sorption absorbent capacity at a height of 140 cm of from about 7 g/g to about 18 g/g.

35. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 200 cm of from about 3 g/g to about 25 g/g.

36. The absorbent member of claim 35 having a capillary sorption absorbent capacity at a height of 200 cm of from about 6 g/g to about 15 g/g.

37. The storage absorbent member of claim 30 having an initial effective uptake rate at 200 cm of at least about 3 g/g/hr.

38. The storage absorbent member of claim 37 having an initial effective uptake rate at 200 cm of at least about 4 g/g/hr.

39. The storage absorbent member of claim 38 having an initial effective uptake rate at 200 cm of at least about 8 g/g/hr.

40. The storage absorbent member of claim 30 wherein the storage absorbent member has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 6 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 5 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 4 g/g.

41. The storage absorbent member of claim 40 wherein the storage absorbent member has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 8 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 7 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 6 g/g.

42. The storage absorbent member of claim 41 wherein the storage absorbent member has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 12 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 10 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 8 g/g.

43. The storage absorbent member of claim 42 wherein the storage absorbent member has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 100 cm of at least about 17 g/g;

b) a capillary sorption absorbent capacity at a height of 140 cm of at least about 14 g/g;

or

c) a capillary sorption absorbent capacity at a height of 200 cm of at least about 11 g/g.

44. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 100 cm of from about 4 g/g to about 50 g/g.

45. The storage absorbent member of claim 44 having a capillary sorption absorbent capacity at a height of 100 cm of from about 6 g/g to about 45 g/g.

46. The storage absorbent member of claim 45 having a capillary sorption absorbent capacity at a height of 100 cm of from about 8 g/g to about 40 g/g.

47. The storage absorbent member of claim 46 having a capillary sorption absorbent capacity at a height of 100 cm of from about 12 g/g to about 35 g/g.

48. The storage absorbent member of claim 47 having a capillary sorption absorbent capacity at a height of 100 cm of from about 17 g/g to about 30 g/g.

49. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 140 cm of from about 4 g/g to about 45 g/g.

50. The storage absorbent member of claim 49 having a capillary sorption absorbent capacity at a height of 140 cm of from about 5 g/g to about 40 g/g.

51. The storage absorbent member of claim 50 having a capillary sorption absorbent capacity at a height of 140 cm of from about 7 g/g to about 35 g/g.

52. The storage absorbent member of claim 51 having a capillary sorption absorbent capacity at a height of 140 cm of from about 10 g/g to about 30 g/g.

53. The storage absorbent member of claim 52 having a capillary sorption absorbent capacity at a height of 140 cm of from about 14 g/g to about 25 g/g.

54. The storage absorbent member of claim 30 having a capillary sorption absorbent capacity at a height of 200 cm of from about 3 g/g to about 40 g/g.

55. The storage absorbent member of claim 54 having a capillary sorption absorbent capacity at a height of 200 cm of from about 4 g/g to about 35 g/g.

56. The absorbent member of claim 55 having a capillary sorption absorbent capacity at a height of 200 cm of from about 6 g/g to about 30 g/g.

57. The absorbent member of claim 56 having a capillary sorption absorbent capacity at a height of 200 cm of from about 8 g/g to about 25 g/g.

58. The absorbent member of claim 57 having a capillary sorption absorbent capacity at a height of 200 cm of from about 11 g/g to about 23 g/g.

59. A high capillary suction storage absorbent member comprising an osmotic absorbent and a discrete high surface area material, wherein the high surface area material has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g; and

the storage absorbent member has a capillary sorption absorbent capacity at a height of 50 cm of at least about 7 g/g.

60. An absorbent article comprising the storage absorbent member of claim 59.

61. The storage absorbent member of claim 59 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

62. The storage absorbent member of claim 61 having a capillary sorption absorbent capacity at a height of 50 cm of from about 7 g/g to about 40 g/g.

63. The storage absorbent member of claim 62 having a capillary sorption absorbent capacity at a height of 50 cm of from about 12 g/g to about 30 g/g.

64. The storage absorbent member of claim 61 having a capillary sorption absorbent capacity at a height of 0 cm of at least about 15 g/g.

65. The storage absorbent member of claim 64 wherein the high surface area material is selected from the group consisting of high surface area fibers, a high surface area open-celled, hydrophilic polymeric foam, and mixtures thereof.

66. The storage absorbent member of claim 65 wherein the high surface area material is an open-celled, hydrophilic polymeric foam having a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g.

67. The absorbent member of claim 65 wherein the high surface area material comprises high surface area fibers having a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g.

68. The absorbent member of claim 61 having a capillary sorption absorbent capacity at a height of 50 cm of at least about 9 g/g.

69. The absorbent member of claim 68 having capillary sorption absorbent capacity at a height of 50 cm of at least about 12 g/g.

70. The absorbent member of claim 69 having capillary sorption absorbent capacity at a height of 50 cm of at least about 16 g/g.

71. The absorbent member of claim 70 having capillary sorption absorbent capacity at a height of 50 cm of at least about 21 g/g.

72. The storage absorbent member of claim 61 having a capillary sorption absorbent capacity at a height of 50 cm of from about 7 g/g to about 60 g/g.

73. The storage absorbent member of claim 72 having a capillary sorption absorbent capacity at a height of 50 cm of from about 9 g/g to about 50 g/g.

74. The storage absorbent member of claim 73 having a capillary sorption absorbent capacity at a height of 50 cm of from about 12 g/g to about 45 g/g.

75. The storage absorbent member of claim 74 having a capillary sorption absorbent capacity at a height of 50 cm of from about 16 g/g to about 40 g/g.

76. The storage absorbent member of claim 75 having a capillary sorption absorbent capacity at a height of 50 cm of from about 21 g/g to about 35 g/g.

77. A high capillary suction storage absorbent member comprising an osmotic absorbent and a discrete high surface area material, wherein the high surface area material has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g; and

the absorbent member has a capillary sorption absorbent capacity at a height of 35 cm of at least about 12 g/g.

78. An absorbent article comprising the storage absorbent member of claim 77.

79. The storage absorbent member of claim 77 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

80. The storage absorbent member of claim 79 having a capillary sorption absorbent capacity at a height of 35 cm of from about 12 g/g to about 60 g/g.

81. The storage absorbent member of claim 79 having a capillary sorption absorbent capacity at a height of 0 cm of at least about 15 g/g.

82. The storage absorbent member of claim 79 wherein the high surface area material is selected from the group consisting of high surface area fibers, a high surface area open-celled, hydrophilic polymeric foam, and mixtures thereof.

83. The absorbent member of claim 82 wherein the high surface area material is a high surface area open-celled, hydrophilic polymeric foam having a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g.

84. The absorbent member of claim 82 wherein the high surface area material comprises high surface area fibers having a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g.

85. The storage absorbent member of claim 79 having a capillary sorption absorbent capacity at a height of 35 cm of at least about 14 g/g.

86. The storage absorbent member of claim 85 having a capillary sorption absorbent capacity at a height of 35 cm of from about 16 g/g to about 40 g/g.

87. The storage absorbent member of claim 85 having a capillary sorption absorbent capacity at a height of 35 cm of at least about 16 g/g.

88. The storage absorbent member of claim 87 having a capillary sorption absorbent capacity at a height of 35 cm of at least about 20 g/g.

89. The storage absorbent member of claim 88 having a capillary sorption absorbent capacity at a height of 35 cm of at least about 22 g/g.

90. The storage absorbent member of claim 79 having a capillary sorption absorbent capacity at a height of 35 cm of from about 12 g/g to about 70 g/g.

91. The storage absorbent member of claim 90 having a capillary sorption absorbent capacity at a height of 35 cm of from about 14 g/g to about 60 g/g.

92. The storage absorbent member of claim 91 having a capillary sorption absorbent capacity at a height of 35 cm of from about 16 g/g to about 55 g/g.

93. The storage absorbent member of claim 92 having a capillary sorption absorbent capacity at a height of 35 cm of from about 20 g/g to about 50 g/g.

94. The storage absorbent member of claim 93 having a capillary sorption absorbent capacity at a height of 35 cm of from about 22 g/g to about 45 g/g.

95. A high capillary suction storage absorbent member comprising an osmotic absorbent and a discrete high surface area material, wherein the high surface area material has one or more of the following:

a) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

b) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

c) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

d) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

or

e) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g; and

the member has a capillary sorption absorbent capacity at a height of 0 cm of at least about 15 g/g and having one or more of the following;

(a) a capillary absorption efficiency at a height of 100 cm of at least about 25%;

(b) a capillary absorption efficiency at a height of 50 cm of at least about 30%;

(c) a capillary absorption efficiency at a height of 35 cm of at least about 50%.

96. An absorbent article comprising the storage absorbent member of claim 95.

97. The storage absorbent member of claim 95 wherein the osmotic absorbent is a hydrogel-forming absorbent polymer.

98. The storage absorbent member of claim 97 having a capillary absorption efficiency at a height of 100 cm of at least about 40%.

99. The absorbent member of claim 97 having a capillary absorption efficiency at a height of 50 cm of at least about 50%.

100. The absorbent member of claim 97 having a capillary absorption efficiency at a height of 35 cm of at least about 70%.

101. The storage absorbent member of claim 97 having a capillary absorption efficiency at a height of 100 cm of at least about 60%.

102. The absorbent member of claim 97 having a capillary absorption efficiency at a height of 50 cm of at least about 70%.

103. The absorbent member of claim 97 having a capillary absorption efficiency at a height of 35 cm of at least about 85%.

104. A high capillary suction storage absorbent member comprising an osmotic absorbent and a discrete high surface area material, the member having a capillary sorption absorbent capacity at a height of 0 cm of at least about 15 g/g and having a medium absorption height of at least about 35 cm.

105. An absorbent article comprising the storage absorbent member of claim 104.

106. The absorbent member of claim 104 having a medium absorption height of at least about 40 cm.

107. The absorbent member of claim 106 having a medium absorption height of at least about 50 cm.

108. The absorbent member of claim 107 having a medium absorption height of at least about 100 cm.

109. A method of forming an absorbent member comprising the steps of:

a) providing an osmotic absorbent;

b) providing high surface area fibers wherein the high surface area fibers have one or more of the following;

i) a capillary sorption absorbent capacity at a height of 35 cm of at least about 5 g/g;

ii) a capillary sorption absorbent capacity at a height of 50 cm of at least about 4 g/g;

iii) a capillary sorption absorbent capacity at a height of 100 cm of at least about 2 g/g;

iv) a capillary sorption absorbent capacity at a height of 140 cm of at least about 1 g/g;

v) a capillary sorption absorbent capacity at a height of 200 cm of at least about 1 g/g;

c) forming a suspension of the osmotic absorbent and the high surface area fibers in a liquid which is incapable of being absorbed to a significant extent by said osmotic absorbent;

d) combining the osmotic absorbent and the high surface area fibers in the suspension;

e) removing liquid from the suspension to thereby form a dry structure of uniform moisture content comprising the osmotic absorbent and the high surface area fibers.

110. A method according to claim 109 wherein the high surface area fibers are glass micro fibers.

111. A method according to claim 109 wherein the cosmotic material is a hydrogel-forming absorbent polymer.

112. A method according to claim 109 the liquid is selected from the group consisting of alcohol and isopropanol.