US5149334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbent articles containing interparticle crosslinked aggregates
Assignee: Procter and Gamble Co
•
Filing: 1990-04-02
•
Granted: 1992-09-22
•
Expires: 2010-04-02
Abstract
Abstract Absorbent articles such as diapers or sanitary napkins incorporating particulate, absorbent, polymeric compositions comprising interparticle crosslinked aggregates. The interparticle crosslinked aggregates comprise precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material; and an interparticle crosslinking agent reacted with the polymer material of the precursor particles to form crosslink bonds between the precursor particles. The polymeric compositions of the present invention may be incorporated into absorbent articles as the sole absorbent material; as an absorbent core comprising a mixture of fiber material and discrete particles of the polymeric composition; or as a laminate (a layered absorbent core) containing such polymeric compositions. The performance of absorbent articles is enhanced by the use of such polymeric compositions due to the high rate of fluid uptake and minimal gel blocking properties of the interparticle crosslinked aggregates.
Inventors
- 👤 Frank H. Lahrman
- 👤 Charles J. Berg
- 👤 Donald C. Roe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:52
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/53; A61F13/534; A61F13/535; A61F13/537; A61F13/53708; A61F13/53717; A61F13/53743; A61F13/53747; A61F13/53752; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; A61F13/45; A61F13/49; A61F13/51; A61F13/531; A61F13/532; A61F13/533; A61F13/15203; A61F2013/15284; A61F2013/15365; A61F2013/15487; A61F2013/15536; A61F13/15577; A61F2013/15821; A61F13/49007; A61F13/49009; A61F13/4902; A61F2013/49031; A61F2013/49033; A61F2013/51002; A61F2013/51023; A61F2013/5103; A61F13/514; A61F13/51401; A61F2013/51409; A61F2013/51411; A61F13/51474; A61F2013/51486; A61F2013/5149; A61F2013/530007; A61F2013/530131; A61F2013/530226; A61F2013/530299; A61F2013/530481; A61F2013/530489; A61F2013/530496; A61F2013/53051; A61F2013/530518; A61F2013/530532; A61F2013/53054; A61F2013/530547; A61F2013/530569; A61F2013/530583; A61F2013/530591; A61F2013/530598; A61F2013/530671; A61F2013/5307; A61F2013/530708; A61F2013/530737; A61F2013/530766; A61F2013/53445; A61F2013/53795; A61F13/84; A61F2013/8488; A61F2013/8491
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
216 words
A disposable absorbent article comprising: a liquid pervious topsheet; a liquid impervious backsheet joined with said topsheet; and an absorbent core positioned between said topsheet and said backsheet, said absorbent core comprising a particulate, absorbent, polymeric composition comprising interparticle covalently crosslinked aggregates, said interparticle crosslinked aggregates comprising (i) substantially dry precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material; said polymer material of said precursor particles being selected from the group consisting of hydrolyzed starch-acrylonitrile graft copolymer, partially neutralized starch-acrylonitrile acid graft copolymer, starch-acrylic acid graft copolymer, partially neutralized starch-acrylic acid graft copolymer, saponified vinyl acetate-acrylic ester copolymers, hydrolyzed acrylonitrile or acrylamide copolymers, slightly network crosslinked products of any of the foregoing copolymers, partially neutralized polyacrylic acid, and slightly network crosslinked products of partially neutralized polyacrylic acid; and (ii) an interparticle crosslinking agent reacted with said polymer material of said precursor particles to form crosslink bonds between said precursor particles; said interparticle crosslinking agent being selected from the group consisting of polyhydric alcohol compounds, polyglycidyl ether compounds, polyfunctional aziridine compounds, polyfunctional amine compounds, and polyfunctional isocyanate compounds; said interparticle crosslinked aggregates being present in said polymeric composition in an amount such that said polymeric composition has a mass average particle size at least about 30% greater than the mass average particle size of said precursor particles.
Claim 2
Dependent Claim
216 words
A disposable absorbent article comprising: a liquid pervious topsheet; a liquid impervious backsheet joined with said topsheet; and an absorbent core positioned between said topsheet and said backsheet, said absorbent core comprising a particulate, absorbent, polymeric composition comprising interparticle covalently crosslinked aggregates, said interparticle crosslinked aggregates comprising (i) substantially dry precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material; said polymer material of said precursor particles being selected from the group consisting of hydrolyzed starch-acrylonitrile graft copolymer, partially neutralized starch-acrylonitrile acid graft copolymer, starch-acrylic acid graft copolymer, partially neutralized starch-acrylic acid graft copolymer, saponified vinyl acetate-acrylic ester copolymers, hydrolyzed acrylonitrile or acrylamide copolymers, slightly network crosslinked products of any of the foregoing copolymers, partially neutralized polyacrylic acid, and slightly network crosslinked products of partially neutralized polyacrylic acid; and (ii) an interparticle crosslinking agent reacted with said polymer material of said precursor particles to form crosslink bonds between said precursor particles; said interparticle crosslinking agent being selected from the group consisting of polyhydric alcohol compounds, polyglycidyl ether compounds, polyfunctional aziridine compounds, polyfunctional amine compounds, and polyfunctional isocyanate compounds; said interparticle crosslinked aggregates being present in said polymeric composition in an amount such that said polymeric composition has a mass average particle size at least about 30% greater than the mass average particle size of said precursor particles.
Claim 3
Dependent Claim
31 words
The absorbent article of claim 1 wherein said polymeric composition has a mass average particle size at least about 50% greater than the mass average particle size of said precursor particles.
Claim 4
Dependent Claim
24 words
The absorbent article of claim 1 wherein said absorbent core comprises an absorbent member comprising a mixture of fiber material and said polymeric composition.
Claim 5
Dependent Claim
69 words
The absorbent article of claim 3 wherein said absorbent member comprises a storage zone and an acquisition zone having a lower average density and a lower average basis weight per unit area than said storage zone, said storage at least partially laterally surrounding the perimeter of said acquisition zone so as to be in liquid communication with at least a portion of the lateral area of said acquisition zone.
Claim 6
Dependent Claim
24 words
The absorbent article of claim 3 wherein said absorbent core additionally comprises an absorbent acquisition layer positioned between said topsheet and said absorbent member.
Claim 7
Dependent Claim
30 words
The absorbent article of claim 5 wherein said absorbent member has a top surface area that is from about 0.25 to about 1.0 times that of said absorbent acquisition layer.
Claim 8
Dependent Claim
17 words
The absorbent article of claim 6 wherein said absorbent acquisition layer consists essentially of hydrophilic fiber material.
Claim 9
Dependent Claim
30 words
The absorbent article of claim 5 wherein said absorbent acquisition layer has a top surface area that is from about 0.25 to about 1.0 times that of said absorbent member.
Claim 10
Dependent Claim
16 words
The absorbent article of claim 8 wherein said absorbent acquisition layer comprises chemically stiffened cellulosic fibers.
Claim 11
Dependent Claim
32 words
The absorbent article of claim 3 wherein said absorbent core additionally comprises a dusting layer positioned between said backsheet and said absorbent member, said dusting layer consisting essentially of hydrophilic fiber material.
Claim 12
Dependent Claim
19 words
The absorbent article of claim 10 wherein said dusting layer is relatively thinner in thickness than said absorbent member.
Claim 13
Dependent Claim
17 words
The absorbent article of claim 3 wherein said polymeric composition is uniformly distributed throughout said absorbent member.
Claim 14
Dependent Claim
24 words
The absorbent article of claim 12 wherein said absorbent member has a density between about 0.06 g/cm 3 and about 0.3 g/cm 3 .
Claim 15
Dependent Claim
20 words
The absorbent article of claim 1 additionally comprising an absorbent acquisition layer juxtaposed between said polymeric composition and said topsheet.
Claim 16
Dependent Claim
74 words
The absorbent article of claim 1 wherein said absorbent core comprises a layered absorbent member comprising (a) n webs of fibrous materials, n being an integer of two or more, said webs being layered such that there is an uppermost web, a lowermost web, n-2 intermediate webs, and n-1 interfaces of two opposed adjacent contacting surfaces of adjacent webs; and (b) said polymeric composition forming a layer at one or more of said interfaces.
Claim 17
Dependent Claim
31 words
The absorbent article of claim 15 wherein the particles of said polymeric composition are discretely spaced from each other, said webs comprise absorbent tissue, and n is between 2 and 12.
Claim 18
Dependent Claim
19 words
The absorbent article of claim 16 wherein said polymeric composition is bonded to one or more of said webs.
Claim 19
Dependent Claim
27 words
The absorbent article of claim 15 wherein n equals 2 and the edges of said webs are joined together around the periphery of the layered absorbent member.
Claim 20
Dependent Claim
12 words
The absorbent article of claim 1, 3, or 15 comprising a diaper.
Claim 21
Dependent Claim
13 words
The absorbent article of claim 1, 3, or 15 comprising a sanitary napkin.
Claim 22
Dependent Claim
165 words
A disposable diaper comprising: a liquid pervious topsheet; a liquid impervious backsheet joined with said topsheet; and an absorbent core positioned between said topsheet and said backsheet, said absorbent core comprising a mixture of hydrophilic fiber material and a particulate, absorbent, polymeric composition comprising interparticle covalently crosslinked aggregates, said interparticle crosslinked aggregates comprising (i) substantially dry precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material, said polymer material of said precursor particles consisting essentially of slightly network crosslinked products of partially neutralized polyacrylic acid, and (ii) an interparticle crosslinking agent reacted with said polymer material of said precursor particles to form crosslink bonds between said precursor particles; said interparticle crosslinking agent being selected from the group consisting of glycerol, trimethylol propane, 1,2-propanediol, 1,3-propanediol, or ethylene glycol; said interparticle crosslinked aggregates being present in said polymeric composition in an amount such that said polymeric composition has a mass average particle size at least about 30% greater than the mass average particle size of said precursor particles.
Claim 23
Dependent Claim
165 words
A disposable diaper comprising: a liquid pervious topsheet; a liquid impervious backsheet joined with said topsheet; and an absorbent core positioned between said topsheet and said backsheet, said absorbent core comprising a mixture of hydrophilic fiber material and a particulate, absorbent, polymeric composition comprising interparticle covalently crosslinked aggregates, said interparticle crosslinked aggregates comprising (i) substantially dry precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material, said polymer material of said precursor particles consisting essentially of slightly network crosslinked products of partially neutralized polyacrylic acid, and (ii) an interparticle crosslinking agent reacted with said polymer material of said precursor particles to form crosslink bonds between said precursor particles; said interparticle crosslinking agent being selected from the group consisting of glycerol, trimethylol propane, 1,2-propanediol, 1,3-propanediol, or ethylene glycol; said interparticle crosslinked aggregates being present in said polymeric composition in an amount such that said polymeric composition has a mass average particle size at least about 30% greater than the mass average particle size of said precursor particles.
Claim 24
Dependent Claim
16 words
The absorbent article of claim 21 wherein at least said interparticle crosslinked aggregates are surface crosslinked.
Claim 25
Dependent Claim
15 words
The absorbent article of claim 22 wherein said hydrophilic fiber material comprises wood pulp fibers.
Claim 26
Dependent Claim
70 words
The absorbent article of claim 23 wherein said absorbent core comprises a storage zone and an acquisition zone having a lower average density and a lower average basis weight per unit area than said storage zone, said storage zone at least partially laterally surrounding the perimeter of said acquisition zone so as to be in liquid communication with at least a portion of the lateral area of said acquisition zone.
Claim 27
Dependent Claim
37 words
The absorbent article of claim 1, 3, 15, 21, 22, or 24 wherein said polymeric composition has a mass average particle size at least about 50% greater than the mass average particle size of said precursor particles.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-22 | 2004-03-23 | 2004-09-22 | $7700.00 | Window Closed / Lapsed |