US4076673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbent articles and methods for their preparation
Assignee: Dow Chemical Co
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Filing: 1976-09-27
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Granted: 1978-02-28
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Expires: 1996-09-27
Abstract
Abstract Water swellable absorbent articles, made from solutions of carboxylic polyelectrolytes, together with methods for their preparation, and a composition useful to make said articles are disclosed. The articles are cured and/or crosslinked with polyamide-polyamine epichlorohydrin adducts by heating and/or removing subsantially all of the solvent from the precursor composition. The absorbent articles are useful as surgical sponges, diapers, tampons, meat trays, bath mats and the like.
Inventors
- 👤 Nelson D. Burkholder, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:29
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; C; C08; C08L; C08L33/00; C08L35/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
106 words
A method of preparing a substantially dry, water-swellable polyelectrolyte film which comprises the steps of (1) preparing a solution of (A) a member selected from the group consisting of water, lower alcohols, and mixtures thereof, (B) about 5 to about 60% by weight based on the amount of (A) of a carboxylic polyelectrolyte or mixtures thereof, and (C) an amount of a water soluble polyamidopolyamine/epichlorohydrin adduct sufficient to cure said polyelectrolyte into a water swellable article, (2) spreading a coating of said solution on an impervious substrate, (3) drying said coated substrate to crosslink said polyelectrolyte and (4) separating said crosslinked polyelectrolyte film from said substrate.
Claim 2
Independent Claim
106 words
A method of preparing a substantially dry, water-swellable polyelectrolyte film which comprises the steps of (1) preparing a solution of (A) a member selected from the group consisting of water, lower alcohols, and mixtures thereof, (B) about 5 to about 60% by weight based on the amount of (A) of a carboxylic polyelectrolyte or mixtures thereof, and (C) an amount of a water soluble polyamidopolyamine/epichlorohydrin adduct sufficient to cure said polyelectrolyte into a water swellable article, (2) spreading a coating of said solution on an impervious substrate, (3) drying said coated substrate to crosslink said polyelectrolyte and (4) separating said crosslinked polyelectrolyte film from said substrate.
Claim 3
Independent Claim
108 words
A method of preparing substantially water swellable polyelectrolyte fibers which comprises (1) preparing a solution of (A) a member selected from the group consisting of water, lower alcohols, and mixtures thereof, (B) about 5 to about 60% by weight based on the amount of (A) of a carboxylic polyelectrolyte or mixtures thereof, and (C) an amount of a water soluble polyamidopolyamine/epichlorohydrin adduct sufficient to cure said polyelectrolyte into a water swellable article. (2) extruding said solution into a bath comprising lower alkyl ketones or chlorinated hydrocarbons to form an extruded fiber, (3) separating the extruded fiber from said bath, and (4) drying said fibers to crosslink said polyelectrolyte.
Claim 4
Independent Claim
108 words
A method of preparing substantially water swellable polyelectrolyte fibers which comprises (1) preparing a solution of (A) a member selected from the group consisting of water, lower alcohols, and mixtures thereof, (B) about 5 to about 60% by weight based on the amount of (A) of a carboxylic polyelectrolyte or mixtures thereof, and (C) an amount of a water soluble polyamidopolyamine/epichlorohydrin adduct sufficient to cure said polyelectrolyte into a water swellable article. (2) extruding said solution into a bath comprising lower alkyl ketones or chlorinated hydrocarbons to form an extruded fiber, (3) separating the extruded fiber from said bath, and (4) drying said fibers to crosslink said polyelectrolyte.
Claim 5
Dependent Claim
35 words
A method of preparing a substantially dry water swellable particulate polyelectrolyte which comprises (1) preparing a film as set forth in claim 1 and (2) disintegrating said film to form flakes, strips, or powders thereof.
Claim 6
Dependent Claim
9 words
The film prepared by the method of claim 1.
Claim 7
Dependent Claim
10 words
The particulate polyelectrolyte produced by the method of claim 3.
Claim 8
Dependent Claim
10 words
The polyelectrolyte fiber produced by the method of claim 2.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the amount of carboxylic polyelectrolyte is about 15 to about 40% by weight.
Claim 10
Dependent Claim
25 words
The method of claim 1 wherein the carboxylic polyelectrolyte is an ammonium or alkali metal salt of the homopolymers of acrylic acid or methacrylic acid.
Claim 11
Dependent Claim
18 words
The method of claim 8 wherein the amount of homopolymer is about 15 to about 40% by weight.
Claim 12
Dependent Claim
28 words
The method of claim 1 wherein the carboxylic polyelectrolyte is an ammonium or alkali metal salt of the copolymers of acrylic or methacrylic acid with monoethylenically unsaturated monomers.
Claim 13
Dependent Claim
18 words
The method of claim 10 wherein the amount of copolymer is about 15 to about 40% by weight.
Claim 14
Dependent Claim
28 words
The method of claim 10 wherein the carboxylic polyelectrolyte consists of a terpolymer of ethyl acrylate, sodium acrylate, and sodium methacrylate with 50 mole percent being ethyl acrylate.
Claim 15
Dependent Claim
13 words
The method of claim 8 wherein the carboxylic polyelectrolyte consists of polysodium acrylate.
Claim 16
Dependent Claim
19 words
The method of claim 2 wherein the amount of carboxylic polyelectrolyte is about 15 to about 40% by weight.
Claim 17
Dependent Claim
25 words
The method of claim 2 wherein the carboxylic polyelectrolyte is an ammonium or alkali metal salt of the homopolymers of acrylic acid or methacrylic acid.
Claim 18
Dependent Claim
18 words
The method of claim 15 wherein the amount of homopolymer is about 15 to about 40% by weight.
Claim 19
Dependent Claim
28 words
The method of claim 2 wherein the carboxylic polyelectrolyte is an ammonium or alkali metal salt of the copolymers of acrylic or methacrylic acid with monoethylenically unsaturated monomers.
Claim 20
Dependent Claim
18 words
The method of claim 17 wherein the amount of copolymer is about 15 to about 40% by weight.
Claim 21
Dependent Claim
28 words
The method of claim 17 wherein the carboxylic polyelectrolyte consists of a terpolymer of ethyl acrylate, sodium acrylate, and sodium methacrylate with 50 mole percent being ethyl acrylate.
Claim 22
Dependent Claim
13 words
The method of claim 15 wherein the carboxylic polyelectrolyte consists of polysodium acrylate.
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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) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |