US3901238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disposable diaper having a resin treated absorbent pad to improve integrity, softness and dryness
Assignee: Procter and Gamble Co
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Filing: 1974-03-18
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Granted: 1975-08-26
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Expires: 1994-03-18
Abstract
Abstract A disposable diaper combining improved softness and sufficient strength to resist in use tearing and shredding in a single structure, thereby producing better compliance and fit when the structure is applied to the wearer, and hence improved comfort as well as better containment of waste fluids deposited thereon. In a preferred embodiment, a disposable diaper of the present invention employs an air laid absorbent cellulosic core reinforced by the application of a hydrophobic resin at relatively low levels of solids addition to one side thereof with subsequent drying, curing and calendering to the desired overall density. With sufficient strength built into the resin treated surface of the absorbent core structure, the unreinforced surface of the absorbent core can be adhered directly to a soft, waterproof backsheet, thereby producing a unique softness, texture and hand. In addition to improved strength and softness, a resin-stabilized absorbent core of the present invention exhibits improved surface dryness due to favorable density and capillary gradients which provide improved liquid penetration from the resin treated surface of the core to the non-resin treated portions of the core. By combining the resin-stabilized absorbent core with a fast strike-through topsheet in a disposable diaper structure, the gasket-like waterproof side flaps normally required to prevent liquid run-off can be eliminated.
Inventors
- 👤 Dale A Gellert
- 👤 Kendall L Harden
- 👤 John R Noel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:50
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/15577; A61F13/15585; A61F13/15666; A61F13/15674; A61F13/53; A61F13/534; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/425; A61F13/537; A61F13/539; A61F2013/15821; A61F13/51; A61F2013/51059; A61F2013/51061; A61F13/514; A61F13/51401; A61F2013/51409; A61F2013/53445; A61F13/53708; A61F2013/53721; A61F2013/53908
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
162 words
A method of producing a soft, reinforced body fluid absorbent fibrous web having sufficient strength to resist tearing and shredding when used as an body fluid absorbent core, comprising the steps of: a. treating one surface of an uncompacted absorbent web of hydrophilic fibers having a basis weight between about 80 grams per square meter and about 500 grams per square meter and a density between about 0.03 grams per cubic centimeter and about 0.05 grams per cubic centimeter by applying a hydrophobic, film-forming material thereto to a depth not exceeding 50 percent of the total thickness of said web in the uncompacted state; b. drying the film-forming material applied to the surface of said web while said web is in the uncompacted state so that the material is non-tacky and will not self-adhere upon compaction of the web; and c. compacting said web to an overall density between about 0.09 grams per cubic centimeter and about 0.13 grams per cubic centimeter.
Claim 2
Independent Claim
162 words
A method of producing a soft, reinforced body fluid absorbent fibrous web having sufficient strength to resist tearing and shredding when used as an body fluid absorbent core, comprising the steps of: a. treating one surface of an uncompacted absorbent web of hydrophilic fibers having a basis weight between about 80 grams per square meter and about 500 grams per square meter and a density between about 0.03 grams per cubic centimeter and about 0.05 grams per cubic centimeter by applying a hydrophobic, film-forming material thereto to a depth not exceeding 50 percent of the total thickness of said web in the uncompacted state; b. drying the film-forming material applied to the surface of said web while said web is in the uncompacted state so that the material is non-tacky and will not self-adhere upon compaction of the web; and c. compacting said web to an overall density between about 0.09 grams per cubic centimeter and about 0.13 grams per cubic centimeter.
Claim 3
Dependent Claim
50 words
The method of claim 1, wherein the hydrophobic, film-forming material is comprised of a resin having a glass transition temperature between about -15*C and about +35*C, said resin being applied at a level between about 5 grams and about 16 grams of resin solids per square meter of absorbent web.
Claim 4
Independent Claim
167 words
A method of producing a soft, reinforced absorbent fibrous web having improved dryness characteristics on one surface thereof, comprising the steps of: a. treating one surface of an uncompacted absorbent web of hydrophilic fibers having a basis weight between about 80 grams per square meter and about 500 grams per square meter and a density between about 0.03 grams per cubic centimeter and about 0.05 grams per cubic centimeter by applying a hydrophobic, film-forming material thereto; b. drying and curing the film-forming material applied to the surface of said web while said web is in the uncompacted state; c. compacting said web to an overall density between about 0.07 grams per cubic centimeter and about 0.15 grams per cubic centimeter, whereby the resulting density of the treated surface of said web is lower than the resulting density of the untreated portions thereof to provide a capillary size gradient favorable to the transmission of liquid from the treated surface of said absorbent web to the untreated portions thereof.
Claim 5
Independent Claim
167 words
A method of producing a soft, reinforced absorbent fibrous web having improved dryness characteristics on one surface thereof, comprising the steps of: a. treating one surface of an uncompacted absorbent web of hydrophilic fibers having a basis weight between about 80 grams per square meter and about 500 grams per square meter and a density between about 0.03 grams per cubic centimeter and about 0.05 grams per cubic centimeter by applying a hydrophobic, film-forming material thereto; b. drying and curing the film-forming material applied to the surface of said web while said web is in the uncompacted state; c. compacting said web to an overall density between about 0.07 grams per cubic centimeter and about 0.15 grams per cubic centimeter, whereby the resulting density of the treated surface of said web is lower than the resulting density of the untreated portions thereof to provide a capillary size gradient favorable to the transmission of liquid from the treated surface of said absorbent web to the untreated portions thereof.
Claim 6
Dependent Claim
50 words
The method of claim 3, wherein the hydrophobic, film-forming material is comprised of a resin having a glass transition temperature between about -15*C and about +35*C, said resin being applied at a level between about 5 grams and about 16 grams of resin solids per square meter of absorbent web.
Claim 7
Dependent Claim
16 words
The method of claim 4, wherein said hydrophobic film-forming material is comprised of a styrene-butadiene resin.
Claim 8
Dependent Claim
22 words
The method of claim 4, wherein said resin is applied at a solids content between about 10 percent and about 55 percent.
Claim 9
Dependent Claim
52 words
The method of claim 3, wherein drying and curing of the treated surface of said absorbent web is accomplished by subjecting said web to a forced convection of warm, dry air for a period of time sufficient to reduce the total Moisture content of said absorbent web to below about 5 percent.
Claim 10
Dependent Claim
18 words
The method of claim 7, wherein the temperature of said warm, dry air is at least about 270*F.
Claim 11
Dependent Claim
38 words
The method of claim 3, wherein said hydrophobic, film-forming material is applied to one surface of said uncompacted absorbent web to a depth not exceeding 50 percent of the total thickness of said web in the uncompacted state.
Claim 12
Dependent Claim
239 words
A disposable diaper having improved softness, texture and hand as well as sufficient strength to resist in use tearing and shredding, said diaper including a unitary absorbent pad of varying density and having means for promoting rapid transmission of liquids from the surface receiving said liquids into the interior of said pad, said diaper comprising: a. an absorbent pad of entangled, hydrophilic fibers, the fibers on one surface thereof having a coating of a hydrophobic film-forming material thereon, the surface of said absorbent pad containing said coated hydrophilic fibers exhibiting a lower density than the portions of said pad containing uncoated hydrophilic fibers, thereby providing a capillary size gradient favorable to the transmission of liquid from the surface of said absorbent pad containing said coated fibers to the portions of said pad containing said uncoated fibers, said absorbent pad having an overall density between about 0.09 and about 0.13 grams per cubic centimeter as measured under a load of 20 grams per square centimeter and a wet tensile strength of at least about 0.5 pounds per inch of pad width; and b. a soft, waterproof backsheet adhered directly to the surface of said absorbent pad containing said uncoated hydrophilic fibers, whereby improved containment of waste fluids deposited on the surface of said absorbent pad containing said coated hydrophilic fibers and improved wearer comfort are provided due to better compliance and fit when said diaper is applied to the wearer.
Claim 13
Dependent Claim
239 words
A disposable diaper having improved softness, texture and hand as well as sufficient strength to resist in use tearing and shredding, said diaper including a unitary absorbent pad of varying density and having means for promoting rapid transmission of liquids from the surface receiving said liquids into the interior of said pad, said diaper comprising: a. an absorbent pad of entangled, hydrophilic fibers, the fibers on one surface thereof having a coating of a hydrophobic film-forming material thereon, the surface of said absorbent pad containing said coated hydrophilic fibers exhibiting a lower density than the portions of said pad containing uncoated hydrophilic fibers, thereby providing a capillary size gradient favorable to the transmission of liquid from the surface of said absorbent pad containing said coated fibers to the portions of said pad containing said uncoated fibers, said absorbent pad having an overall density between about 0.09 and about 0.13 grams per cubic centimeter as measured under a load of 20 grams per square centimeter and a wet tensile strength of at least about 0.5 pounds per inch of pad width; and b. a soft, waterproof backsheet adhered directly to the surface of said absorbent pad containing said uncoated hydrophilic fibers, whereby improved containment of waste fluids deposited on the surface of said absorbent pad containing said coated hydrophilic fibers and improved wearer comfort are provided due to better compliance and fit when said diaper is applied to the wearer.
Claim 14
Dependent Claim
22 words
The disposable diaper of claim 10, including a liquid-pervious topsheet secured in superposed relation to the treated surface of said absorbent pad.
Claim 15
Dependent Claim
16 words
The disposable diaper of claim 10, wherein said waterproof backsheet is comprised of matte finish polyethylene.
Claim 16
Dependent Claim
261 words
A disposable diaper exhibiting improved strike-through and surface dryness characteristics, said diaper including a unitary absorbent pad of varying density and having means for promoting rapid transmission of liquids from the surface receiving said liquids into the interior of said pad, said diaper comprising: a. an absorbent pad of compressed, entangled, hydrophilic fibers, the fibers on one surface of said absorbent pad having a coating of a cured, hydrophobic, film-forming material thereon, the surface of said absorbent pad containing said coated hydrophilic fibers exhibiting a lower density than the portions of said pad containing uncoated hydrophilic fibers, thereby providing a capillary size gradient favorable to the transmission of liquid from the surface of said absorbent pad containing said coated fibers to the portions of said pad containing said uncoated fibers, said absorbent pad having an overall density between about 0.09 grams per cubic centimeter and about 0.13 grams per cubic centimeter as measured under a load of 20 grams per square centimeter; b. a soft, waterproof backsheet secured to the surface of said absorbent pad containing said uncoated hydrophilic fibers; and c. a liquid-pervious topsheet having a strike-through time of less than about 5 seconds, as measured with said topsheet in adjacent contact with the surface of said absorbent pad containing said coated hydrophilic fibers, secured in superposed relation to the surface of said absorbent pad containing said coated hydrophilic fibers, whereby waste fluids deposited on said topsheet pass rapidly through said topsheet and are absorbed by and partitioned within the portions of said absorbent pad containing said uncoaTed hydrophilic fibers.
Claim 17
Dependent Claim
261 words
A disposable diaper exhibiting improved strike-through and surface dryness characteristics, said diaper including a unitary absorbent pad of varying density and having means for promoting rapid transmission of liquids from the surface receiving said liquids into the interior of said pad, said diaper comprising: a. an absorbent pad of compressed, entangled, hydrophilic fibers, the fibers on one surface of said absorbent pad having a coating of a cured, hydrophobic, film-forming material thereon, the surface of said absorbent pad containing said coated hydrophilic fibers exhibiting a lower density than the portions of said pad containing uncoated hydrophilic fibers, thereby providing a capillary size gradient favorable to the transmission of liquid from the surface of said absorbent pad containing said coated fibers to the portions of said pad containing said uncoated fibers, said absorbent pad having an overall density between about 0.09 grams per cubic centimeter and about 0.13 grams per cubic centimeter as measured under a load of 20 grams per square centimeter; b. a soft, waterproof backsheet secured to the surface of said absorbent pad containing said uncoated hydrophilic fibers; and c. a liquid-pervious topsheet having a strike-through time of less than about 5 seconds, as measured with said topsheet in adjacent contact with the surface of said absorbent pad containing said coated hydrophilic fibers, secured in superposed relation to the surface of said absorbent pad containing said coated hydrophilic fibers, whereby waste fluids deposited on said topsheet pass rapidly through said topsheet and are absorbed by and partitioned within the portions of said absorbent pad containing said uncoaTed hydrophilic fibers.
Claim 18
Dependent Claim
19 words
The disposable diaper of claim 13, wherein said topsheet is comprised of a low density, high loft, hydrophobic material.
Claim 19
Dependent Claim
37 words
The disposable diaper of claim 14, wherein said topsheet is comprised of non-woven, needle-punched polyester fabric having a density of about 0.05 grams per cubic centimeter, as measured under a load of 20 grams per square centimeter.
Claim 20
Dependent Claim
27 words
The disposable diaper of claim 13, wherein said absorbent pad has a minimum wet tensile strength of at least about 0.5 pounds per inch of pad width.
Claim 21
Dependent Claim
50 words
The disposable diaper of claim 13, wherein said waterproof backsheet is adhered directly to the surface of said absorbent pad containing said uncoated hydrophilic fibers and said liquid-pervious topsheet is secured at its periphery to the overlapping portions of said waterproof backsheet to form an envelope about said absorbent pad.
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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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |