Patent US3047789A successfully refreshed from Google Patents.
US4018951A
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Absorbent articles and methods for their preparation
Assignee: Dow Chemical Co
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Filing: 1975-05-09
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Granted: 1977-04-19
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Expires: 1995-05-09
Abstract
Abstract Water swellable absorbent articles, made from carboxylic polyelectrolytes, together with methods for their preparation, and a composition useful to make said articles are disclosed. The articles are crosslinked by heating and/or removing substantially all of the water from the precursor composition.
Inventors
- 👤 James R. Gross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:43
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/16; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
110 words
A method of preparing a substantially dry, water swellable polyelectrolyte film which comprises the steps of A. applying a coating on an impervious substrate wherein the coating comprises 1. a solution of a carboxylic synthetic polyelectrolyte wherein the solution consists of water, lower alcohols, or mixtures thereof and about 5 to about 60% by weight of a carboxylic polyelectrolyte, and 2. at least about 0.1% by weight based on the polyelectrolyte of a crosslinking agent reactive with carboxylate groups B. heating said coated substrate to a temperature greater than about 30° C. to crosslink said polyelectrolyte to form a film, and C. separating said crosslinked polyelectrolyte film from said substrate.
Claim 2
Independent Claim
110 words
A method of preparing a substantially dry, water swellable polyelectrolyte film which comprises the steps of A. applying a coating on an impervious substrate wherein the coating comprises 1. a solution of a carboxylic synthetic polyelectrolyte wherein the solution consists of water, lower alcohols, or mixtures thereof and about 5 to about 60% by weight of a carboxylic polyelectrolyte, and 2. at least about 0.1% by weight based on the polyelectrolyte of a crosslinking agent reactive with carboxylate groups B. heating said coated substrate to a temperature greater than about 30° C. to crosslink said polyelectrolyte to form a film, and C. separating said crosslinked polyelectrolyte film from said substrate.
Claim 3
Dependent Claim
68 words
The method as set forth in claim 1 wherein the solution used comprises 1. water, lower alcohols, and mixtures, thereof, 2. about 5 to about 60% by weight based on the amount of (1) of a carboxylic polyelectrolyte or mixtures thereof, and 3. at least about 0.1% by weight based on the polyelectrolyte of a crosslinking agent selected from polyhaloalkanols, sulfonium zwitterions, haloepoxyalkanes, polyglycidyl ethers, and mixtures thereof.
Claim 4
Dependent Claim
59 words
The method as set forth in claim 1 wherein the solution used comprises 1. water, lower alcohols, and mixtures thereof, 2. about 5 to about 60% by weight based on the amount of (1) of a carboxylic polyelectrolyte or mixtures thereof, and 3. at least about 0.1% by weight based on the polyelectrolyte of a polyglycidyl ether crosslinking agent.
Claim 5
Dependent Claim
32 words
The method as set forth in claim 3 wherein the polyglycidyl ether crosslinking agent is a polypropylene glycol diglycidyl ether having an epoxy equivalent weight range from about 175 to about 380.
Claim 6
Dependent Claim
9 words
The film prepared by the method of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |