Patent US3210584A successfully refreshed from Google Patents.
US4468428A
Expired / Lapsed
US
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Hydrophilic microfibrous absorbent webs
Assignee: Procter and Gamble Co
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Filing: 1982-06-01
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Granted: 1984-08-28
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Expires: 2002-06-01
Abstract
Abstract Fibrous absorbent webs having a low density (about 0.01 g/cm3 to about 0.15 g/cm3) and comprising at least about 50% hydrophilic microfibers, such as cellulose microfibers, having a diameter of from about 0.01 microns to about 15 microns possess superior absorption properties, especially under typical usage conditions. Hydrophobic microfibers may also be used, provided such fibers are hydrophilized before or after web formation.
Inventors
- 👤 Allen D. Early
- 👤 David W. Cawlfield
- 👤 Trevor Walker
- 👤 Paul T. Weisman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:02
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/18; A61L15/22; A61L15/28; Y; Y10; Y10S; Y10S428/00; Y10S428/903; Y10S428/913; Y10T; Y10T428/00; Y10T428/249921; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2964; Y10T428/2965; Y10T428/298
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
41 words
A fibrous absorbent web comprising at least about 50% of hydrophilic microfibers having a diameter of from about 0.01 microns to about 15 microns, said web having a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 .
Claim 2
Dependent Claim
41 words
A fibrous absorbent web comprising at least about 50% of hydrophilic microfibers having a diameter of from about 0.01 microns to about 15 microns, said web having a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 .
Claim 3
Dependent Claim
23 words
The fibrous absorbent web of claim 1 wherein the hydrophilic microfibers have a diameter of from about 0.5 microns to about 10 microns.
Claim 4
Dependent Claim
23 words
The fibrous absorbent web of claim 1 which has a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 5
Dependent Claim
38 words
A fibrous absorbent web consisting essentially of hydrophillic microfibers having a diameter of from about 0.5 micron to about 10 microns said web having a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 6
Dependent Claim
38 words
A fibrous absorbent web consisting essentially of hydrophillic microfibers having a diameter of from about 0.5 micron to about 10 microns said web having a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 7
Dependent Claim
14 words
The fibrous absorbent web of claim 4 wherein the hydrophilic microfibers are cellulose fibers.
Claim 8
Dependent Claim
27 words
The fibrous absorbent web of claim 5 wherein the hydrophilic microfibers are selected from the group consisting of wheat fibers, rice fibers, abaca fibers and mixtures thereof.
Claim 9
Dependent Claim
48 words
A fibrous absorbent web comprising at least about 50% of hydrophilic microfibers of a thermoplastic material, said microfibers having a diameter of from about 0.5 microns to about 10 microns, and said web having a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 10
Dependent Claim
48 words
A fibrous absorbent web comprising at least about 50% of hydrophilic microfibers of a thermoplastic material, said microfibers having a diameter of from about 0.5 microns to about 10 microns, and said web having a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 11
Dependent Claim
22 words
The fibrous absorbent web of claim 7 wherein the thermoplastic material is glass; a polyolefin; a polyester; a polyamide; or a polyvinyl.
Claim 12
Dependent Claim
13 words
The fibrous absorbent web of claim 8 wherein the thermoplastic material is polypropylene.
Claim 13
Dependent Claim
14 words
The fibrous absorbent web of claim 8 wherein the thermoplastic polymer is poly(ethylene terephtalate).
Claim 14
Dependent Claim
74 words
A process for making a fibrous absorbent web comprising the steps of selecting a fiber mixture comprising at least about 50% of microfibers having a diameter of from about 0.01 microns to about 15 microns; forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 ; immersing the web in a solution of a cellulose ester; and hydrolyzing the cellulose ester to cellulose.
Claim 15
Dependent Claim
74 words
A process for making a fibrous absorbent web comprising the steps of selecting a fiber mixture comprising at least about 50% of microfibers having a diameter of from about 0.01 microns to about 15 microns; forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 ; immersing the web in a solution of a cellulose ester; and hydrolyzing the cellulose ester to cellulose.
Claim 16
Dependent Claim
94 words
A process for making a fibrous absorbent web comprising the steps of selecting a fiber mixture comprising at least about 50% of microfibers having a diameter of from about 0.01 microns to about 15 microns; forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 ; immersing the web in a colloidal silica solution; and immersing the web in a solution of a wet-strength resin selected from the group consisting of the melamine formaldehyde resins, the urea formaldehyde resins and the polyvinylamide resins.
Claim 17
Dependent Claim
94 words
A process for making a fibrous absorbent web comprising the steps of selecting a fiber mixture comprising at least about 50% of microfibers having a diameter of from about 0.01 microns to about 15 microns; forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 ; immersing the web in a colloidal silica solution; and immersing the web in a solution of a wet-strength resin selected from the group consisting of the melamine formaldehyde resins, the urea formaldehyde resins and the polyvinylamide resins.
Claim 18
Dependent Claim
59 words
A process for making a fibrous absorbent web comprising the steps of: selecting a fiber mixture comprising at least about 50% of cellulose microfibers having a diameter of from about 0.01 microns to about 15 microns; and forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 .
Claim 19
Dependent Claim
59 words
A process for making a fibrous absorbent web comprising the steps of: selecting a fiber mixture comprising at least about 50% of cellulose microfibers having a diameter of from about 0.01 microns to about 15 microns; and forming the fibers into a web which has a density of from about 0.01 g/cm 3 to about 0.15 g/cm 3 .
Claim 20
Dependent Claim
33 words
The process of claim 11 wherein the solution of the cellulose ester is a solution in acetone, and the hydrolyzing step is carried out with a solution of about 1% NaOH in methanol.
Claim 21
Dependent Claim
12 words
The process of claim 11 wherein the cellulose ester is cellulose acetate.
Claim 22
Dependent Claim
30 words
The process of claim 12 wherein the colloidal silica solution has a concentration of from about 0.05% to about 0.2% and a pH of from about 2 to about 5.
Claim 23
Dependent Claim
20 words
The process of claim 12 wherein the wet-strength resin solution has a concentration of from about 0.05% to about 0.2%.
Claim 24
Dependent Claim
27 words
The process of claim 11 wherein the fibers consist of a cellulose derivative selected from the group consisting of cellulose xanthate, cellulose acetate; cellulose triacetate; and rayon.
Claim 25
Dependent Claim
50 words
The process of claim 11 wherein the fiber mixture consists essentially of microfibers having a diameter of from about 0.5 micron to about 10 microns and wherein said fiber mixture is formed into a web having a density of from about 0.04 g/cm 3 to about 0.10 g/cm 3 .
Claim 26
Dependent Claim
11 words
A disposable diaper comprising the fibrous absorbent web of claim 1.
Claim 27
Dependent Claim
11 words
A sanitary napkin comprising the fibrous absorbent web of claim 1.
Claim 28
Dependent Claim
11 words
A towel sheet comprising the fibrous absorbent web of claim 1.
Claim 29
Dependent Claim
11 words
A surgical sponge comprising the fibrous absorbent web of claim 7.
Claim 30
Dependent Claim
11 words
A surgical gown comprising the fibrous absorbent web of claim 7.
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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) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |