EP0429112B1
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EP
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Absorbent structure containing individualized, polycarboxylic acid crosslinked fibers
Assignee: Procter and Gamble Co
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Filing: 1990-10-29
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Granted: 1996-02-28
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Expires: 2010-10-29
Abstract
Abstract Disclosed are absorbent structures containing individualized, crosslinked fibers. The individualized, crosslinked fibers preferably have a C2 - C9 polycarboxylic acid crosslinking agent reacted with the fibers in the form of intrafiber crosslink bonds. Preferably, the crosslinking agent is citric acid, and between about 0.5 mole % and about 10.0 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
- 👤 Carlisle Mitchell Herron
- 👤 David James Cooper
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 05:04
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/001; D21C9/002; D21C9/005; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28; D04; D04H; D04H1/00; D04H1/40; D04H1/58; D04H1/587; D04H1/64; D06; D06M; D06M13/00; D06M13/10; D06M13/184; D06M13/192
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
163 words
An absorbent structure characterized in that it comprises individualized, crosslinked cellulosic fibers having an effective amount of a C₂ - C₉ polycarboxylic acid crosslinking agent reacted with said fibers in an intrafiber crosslink bond form, wherein said C₂ - C₉ polycarboxylic acid crosslinking agent is selected from: (i) aliphatic and alicyclic C₂ - C₉ polycarboxylic acids either olefinically saturated or unsaturated and having at least three carboxyl groups per molecule; and (ii) aliphatic and alicyclic C₂ - C₉ polycarboxylic acids having two carboxyl groups per molecule and having a carbon-carbon double bond located alpha, beta to one or both of the carboxyl groups, if said carboxyl groups are separated by said double bond or if said carboxyl groups are connected to the same ring then said carboxyl groups are in the cis-configuration relative to each other; wherein one carboxyl group in said C₂ - C₉ polycarboxylic acid crosslinking agent is separated from a second carboxyl group by either two or three carbon atoms.
Claim 2
Dependent Claim
45 words
The absorbent structure of Claim 1 wherein said fibers have between 0.5 mole % and 10.0 mole %, preferably between 1.5 mole % and 6.0 mole % crosslinking agent, calculated on a cellulose anhydroglucose molar basis, reacted therewith in the form of intrafiber crosslink bonds.
Claim 3
Dependent Claim
25 words
The absorbent structure of Claim 2 wherein said crosslinked fibers have a water retention value of from 25 to 60, preferably from 28 to 50.
Claim 4
Dependent Claim
29 words
The absorbent structure of any of Claims 1-3 wherein said crosslinking agent is selected from citric acid, 1,2,3,4 butane tetracarboxylic acid, and 1,2,3 propane tricarboxylic acid, preferably citric acid.
Claim 5
Dependent Claim
33 words
The absorbent structure of any of Claims 1-3 wherein said crosslinking agent is selected from oxydisuccinic acid, tartrate monosuccinic acid having the formula and tartrate disuccinic acid having the formula preferably oxydisuccinic acid.
Claim 6
Dependent Claim
34 words
The absorbent structure of any of Claims 1-5 having a dry density and an equilibrium wet density calculated on a dry fiber weight basis, said dry density being greater than said equilibrium wet density.
Claim 7
Dependent Claim
21 words
The absorbent structure of any of Claims 1-6 wherein said absorbent structure has a dry density of less than 0.60 g/cc.
Claim 8
Dependent Claim
23 words
The absorbent structure of any of Claims 1-5 wherein said absorbent structure has a dry density of between 0.05 g/cc and 0.15 g/cc.
Claim 9
Dependent Claim
45 words
The absorbent structure of any of Claims 1-5 wherein said absorbent structure has a dry fiber density of between 0.12 g/cc and 0.60 g/cc and an equilibrium wet density, calculated on a dry fiber weight basis, which is less than said actual dry fiber density.
Claim 10
Dependent Claim
27 words
The absorbent structure of any of Claims 1-9 wherein said structure comprises between 70% and 95% individualized crosslinked fibers, and between 30% and 5% uncrosslinked cellulosic fibers.
Claim 11
Dependent Claim
20 words
The absorbent structure of Claim 10 wherein said uncrosslinked cellulosic fibers have a Canadian Standard Freeness of less than 300.
Claim 12
Dependent Claim
17 words
The absorbent structure of any of Claims 1-11 further comprising a hydrogel-forming material disposed upon said fibers.
Claim 13
Dependent Claim
18 words
The absorbent structure of any of Claims 1-11 further comprising a hydrogel-forming material disposed within said absorbent structure.
Claim 14
Dependent Claim
22 words
The absorbent structure of Claim 13 wherein said hydrogel-forming material is substantially homogeneously blended throughout at least part of said absorbent structure.
Claim 15
Dependent Claim
22 words
The absorbent structure of Claim 13 wherein said hydrogel-forming material is disposed upon a sheet, said sheet being juxtaposed against said fibers.
Claim 16
Dependent Claim
31 words
A disposable absorbent article comprising a topsheet, a backsheet connected to said topsheet, and an absorbent structure, as recited in any of Claims 1-15, disposed between said topsheet and said backsheet.
Claim 17
Dependent Claim
30 words
The absorbent structure of any of Claims 1-5 wherein said absorbent structure has a basis weight of less than 800 g/m², and a dry density of less than 0.60 g/cc.
References Cited (Backward Citations)
No citation records indexed.
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