US4822453A
Expired / Lapsed
US
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Absorbent structure containing individualized, crosslinked fibers
Assignee: Procter and Gamble Co
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Filing: 1986-06-27
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Granted: 1989-04-18
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Expires: 2006-06-27
Abstract
Abstract Absorbent structures containing individualized, crosslinked fibers. The individualized, crosslinked fibers preferably have between about 0.5 mole % and about 3.5 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted with the fibers in the form of intrafiber crosslink bonds, wherein the crosslinking agent is selected from the group consisting of C2-C8 dialdehydes, C2-C8 dialdehyde acid analogues having at least one aldehyde functionality, and oligomers of such C2-C8 dialdehydes and dialdehyde acid analogues. More preferably, the crosslinking agent is glutaraldehyde, and between about 0.75 mole % and about 2.5 mole % crosslinking agent react to form the intrafiber crosslink bonds. Also preferably, the absorbent structures have actual dry densities greater than their corresponding equilibrium wet densities, and expand upon wetting. The absorbent structures may also contain hydrogel-forming material.
Inventors
- 👤 Walter L. Dean
- 👤 Danny R. Moore
- 👤 James W. Owens
- 👤 Howard L. Schoggen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:48
CPC Classifications
D; D01; D01F; D01F8/00; D21; D21C; D21C9/00; D21C9/001; D21C9/002; D21C9/005; A; A61; A61F; A61F13/00; A61F13/15; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28; D06; D06M; D06M11/00; D06M11/32; D06M11/36; D06M11/38; D06M13/00; D06M13/322; D06M13/395
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
137 words
An absorbent structure comprising individualized, twisted and curled, crosslinked cellulosic fibers having between about 0.5 mole % and about 3.5 mole % crosslinking agent, calculated on a cellulosic anhydroglucose molar basis, reacted with said fibers in an intrafiber crosslink bond form, wherein said crosslinking agent is selected from the group consisting of C 2 -C 8 dialdehydes, C 2 -C 8 dialdehyde acid analogues having at least one aldehyde group, and oligomers of said aldehyde and dialdehyde acid analogues, said fibers having been maintained in substantially individual form during drying and crosslinking, said fibers having a WRV of from about 25 to about 60, and said fibers having the property of enabling said absorbent structure to have a wet equilibrium density less than its dry density, said wet equilibrium density being calculated on a dry fiber basis.
Claim 2
Dependent Claim
137 words
An absorbent structure comprising individualized, twisted and curled, crosslinked cellulosic fibers having between about 0.5 mole % and about 3.5 mole % crosslinking agent, calculated on a cellulosic anhydroglucose molar basis, reacted with said fibers in an intrafiber crosslink bond form, wherein said crosslinking agent is selected from the group consisting of C 2 -C 8 dialdehydes, C 2 -C 8 dialdehyde acid analogues having at least one aldehyde group, and oligomers of said aldehyde and dialdehyde acid analogues, said fibers having been maintained in substantially individual form during drying and crosslinking, said fibers having a WRV of from about 25 to about 60, and said fibers having the property of enabling said absorbent structure to have a wet equilibrium density less than its dry density, said wet equilibrium density being calculated on a dry fiber basis.
Claim 3
Dependent Claim
38 words
The absorbent structure of claim 1 wherein said fibers have between about 0.75 mole % and about 2.5 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the form of intrafiber crosslink bonds.
Claim 4
Dependent Claim
22 words
The absorbent structure of claim 1 wherein said crosslinking agent is selected from the group consisting of glutaraldehyde, glyoxal, and glyoxylic acid.
Claim 5
Dependent Claim
12 words
The absorbent structure of claim 3 wherein said crosslinking agent is glutaraldehyde.
Claim 6
Dependent Claim
22 words
The absorbent structure of claim 2 wherein said crosslinking agent is selected from the group consisting of glutaraldehyde, glyoxal, and glyoxylic acid.
Claim 7
Dependent Claim
12 words
The absorbent structure of claim 5 wherein said crosslinking agent is glutaraldehyde.
Claim 8
Dependent Claim
16 words
The absorbent structure of claim 2 wherein said WRV is between about 28 and about 45.
Claim 9
Dependent Claim
16 words
The absorbent structure of claim 3 wherein said WRV is between about 28 and about 45.
Claim 10
Dependent Claim
16 words
The absorbent structure of claim 6 wherein said WRV is between about 28 and about 45.
Claim 11
Dependent Claim
22 words
The absorbent structure of claim 1, 3, 5, 6, or 9 wherein said equilibrium wet density is less than said dry density.
Claim 12
Dependent Claim
20 words
The absorbent structure of claim 1 wherein said absorbent structure has a dry density of less than about 0.60 g/cc.
Claim 13
Dependent Claim
20 words
The absorbent structure of claim 5 wherein said absorbent structure has a dry density of less than about 0.60 g/cc.
Claim 14
Dependent Claim
57 words
The absorbent structure of claim 7 wherein said absorbent structure has a dry density of between about 0.06 g/cc and about 0.15 g/cc and said individualized, crosslinked fibers have between about 2.0 mole % and about 2.5 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the form of intrafiber crosslink bonds.
Claim 15
Dependent Claim
78 words
The absorbent structure of claim 7 wherein said absorbent structure has a dry fiber density of between about 0.12 g/cc and about 0.60 g/cc and an equilibrium wet density, calculated on a dry fiber basis, which is less than said actual dry fiber density, and said individualized, crosslinked fibers have between about 0.75 mole % and about 1.25 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the form of intrafiber crosslink bonds.
Claim 16
Dependent Claim
29 words
The absorbent structure of claim 1 wherein said structure comprises between about 10% and about 95% individualized crosslinked fibers, and between about 5% and about 90% uncrosslinked cellulosic fibers.
Claim 17
Dependent Claim
21 words
The absorbent structure of claim 15 wherein said uncrosslinked, cellulosic fibers have a Canadian Standard Freeness of less than about 300.
Claim 18
Dependent Claim
15 words
The absorbent structure of claim 1 further comprising a hydrogel-forming material disposed upon said fibers.
Claim 19
Dependent Claim
22 words
The absorbent structure of claim 17 wherein said hydrogel-forming material is substantially homogeneously blended throughout as least part of said absorbent structure.
Claim 20
Dependent Claim
22 words
The absorbent structure of claim 1 wherein said hydrogel-forming material is disposed upon a sheet, said sheet being juxtaposed against said fibers.
Claim 21
Dependent Claim
15 words
The absorbent structure of claim 15 further comprising a hydrogel-forming material disposed upon said fibers.
Claim 22
Dependent Claim
15 words
The absorbent structure of claim 16 further comprising a hydrogel-forming material disposed upon said fibers.
Claim 23
Dependent Claim
18 words
The absorbent structure of claim 13 or 14 further comprising a hydrogel-forming material disposed within said absorbent structure.
Claim 24
Dependent Claim
16 words
The absorbent structure of claim 20 further comprising a hydrogel-forming material disposed within said absorbent structure.
Claim 25
Dependent Claim
16 words
The absorbent structure of claim 21 further comprising a hydrogel-forming material disposed within said absorbent structure.
Claim 26
Dependent Claim
40 words
A disposable absorbent article comprising a topsheet, a backsheet connected to said topsheet, and an absorbent structure as recited in claim 1, 11, 13, 14, 15, 16, 17, 18, 19, 23, or 24 disposed between said topsheet and said backsheet.
Claim 27
Dependent Claim
37 words
The absorbent structure of claim 1, 2, 3, 4, or 5 wherein said absorbent structure has a basis weight of less than about 800 g/m 2 , and a dry density of less than about 0.60 g/cc.
Claim 28
Dependent Claim
14 words
The absorbent structure of claim 1 further comprising hydrogel-forming material disposed within said structure.
Claim 29
Dependent Claim
23 words
The absorbent structure of claim 27 wherein said hydrogel-forming material is substantially homogeneously blended throughout at least a part of said absorbent structure.
Claim 30
Dependent Claim
22 words
The absorbent structure of claim 27 wherein said hydrogel-forming material is disposed upon a sheet, said sheet being juxtaposed against said fibers.
Claim 31
Dependent Claim
59 words
The absorbent structure of claim 20 or 21, wherein said absorbent structure has a dry density of between about 0.06 g/cc and about 0.15 g/cc, and said individualized crosslinked fibers have between about 2.0 mole % and about 2.5 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the from of intrafiber crosslink bonds.
Claim 32
Dependent Claim
77 words
The absorbent structure of claim 20 or 21, wherein said absorbent structure has a dry density of between about 0.12 g/cc and about 0.60 g/cc, and an equilibrium wet density, calculated on a dry fiber basis, which is less than said dry density, and said individualized crosslinked fibers have between about 0.75 mole % and about 1.25 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the form of intrafiber crosslink bonds.
Claim 33
Dependent Claim
37 words
The absorbent structure of claim 20 or 21 wherein said absorbent structure has a dry density and an equilibrium wet density, calculated on a dry fiber basis, said equilibrium wet density being less than said dry density.
References Cited (Backward Citations)
US3046079A
Cited
US3069311A
Cited
US3224926A
Cited
US3241553A
Cited
US3455778A
Cited
US3440135A
Cited
US3434918A
Cited
US3932209A
Cited
US3756913A
Cited
US3819470A
Cited
US4035147A
Cited
CA993618A
Cited
US4204054A
Cited
EP0122042A2
Cited
US4689118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |