Patent US4401795A successfully refreshed from Google Patents.
US4401795A
Expired / Lapsed
US
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Polymeric polyelectrolytes
Assignee: Elementis Specialties Inc
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Filing: 1981-01-08
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Granted: 1983-08-30
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Expires: 2001-01-08
Abstract
Abstract There is provided a polymer useful as a water absorbing agent. The polymer preferably contains the reaction product of an olefinically-unsaturated carboxylic acid, an alkyl acrylate and minor amounts of a crosslinking agent all in specified proportions.
Inventors
- 👤 Daniel F. Herman
- 👤 Uno Kruse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:00
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/12; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; C08F220/04; Y; Y10; Y10S; Y10S526/00; Y10S526/93
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
208 words
In an absorbent dressing comprising an absorbent layer containing a water-swellable, water-insoluble material, the improvement which comprises having at least a portion of the water-swellable, water-insoluble material being an alkaline salt of a polymer prepared by the reaction of (a) from about 15% to about 50% by weight of an olefinically-unsaturated carboxylic acid containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group; (b) from about 49.07% to about 82% by weight of an alkyl acrylate wherein the alkyl group has from 1 to 6 carbon atoms; and (c) from about 0.03% to about 3.0% by weight of a crosslinking agent which are polyunsaturated polymerizable vinyl monomers containing two or more free radical polymerizable ethylenic groups, said crosslinking agent being introduced directly into the carbon-carbon backbone of the polymer; and having the formula: ##STR2## wherein: x represents the relative number of alkyl acrylate groups with R being 1 to 6 carbon atoms as component (b); y represents the relative number of olefinically-unsaturated carboxylic acid groups with R' being the hydrocarbon portion of the carboxylic acid compounds of component (a); z represents the relative number of crosslinking agents of component (c) with R" being hydrogen or methyl and R"' comprising the remaining portion of component (c).
Claim 2
Dependent Claim
208 words
In an absorbent dressing comprising an absorbent layer containing a water-swellable, water-insoluble material, the improvement which comprises having at least a portion of the water-swellable, water-insoluble material being an alkaline salt of a polymer prepared by the reaction of (a) from about 15% to about 50% by weight of an olefinically-unsaturated carboxylic acid containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group; (b) from about 49.07% to about 82% by weight of an alkyl acrylate wherein the alkyl group has from 1 to 6 carbon atoms; and (c) from about 0.03% to about 3.0% by weight of a crosslinking agent which are polyunsaturated polymerizable vinyl monomers containing two or more free radical polymerizable ethylenic groups, said crosslinking agent being introduced directly into the carbon-carbon backbone of the polymer; and having the formula: ##STR2## wherein: x represents the relative number of alkyl acrylate groups with R being 1 to 6 carbon atoms as component (b); y represents the relative number of olefinically-unsaturated carboxylic acid groups with R' being the hydrocarbon portion of the carboxylic acid compounds of component (a); z represents the relative number of crosslinking agents of component (c) with R" being hydrogen or methyl and R"' comprising the remaining portion of component (c).
Claim 3
Dependent Claim
31 words
The absorbent dressing of claim 1 comprising from about 20% to about 40% by weight of the olefinically-unsaturated carboxylic acid selected from the group consisting of methacrylic acid and acrylic acid.
Claim 4
Dependent Claim
39 words
The absorbent dressing of claim 1 wherein up to 8% by weight of the total amount of olefinically-unsaturated carboxylic acid present is replaced with a material selected from the group consisting of itaconic acid, maleic acid and maleic anhydride.
Claim 5
Dependent Claim
32 words
The absorbent dressing of claim 1 comprising from about 59.02% to about 78% by weight of the alkyl acrylate selected from the group consisting of methyl acrylate, ethyl acrylate and n-butyl acrylate.
Claim 6
Dependent Claim
16 words
The absorbent dressing of claim 1 comprising about 0.08% to about 2% by weight crosslinking agent.
Claim 7
Dependent Claim
209 words
As an article of manufacture, a flexible support adapted for the absorption of water, said support containing a solid, water-swellable, water-insoluble polymer, said polymer comprising the alkaline salt of a polymer prepared from the reaction of materials consisting essentially of (a) from about 15% to about 50% by weight of an olefinically-unsaturated carboxylic acid containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group; (b) from about 49.07% to about 82% by weight of an alkyl acrylate wherein the alkyl group has from 1 to 6 carbon atoms; and (c) from about 0.03% to about 3.0% by weight of a crosslinking agent which are polyunsaturated polymerizable vinyl monomers containing two or more free radical polymerizable ethylenic groups, said crosslinking agent being introduced directly into the carbon-carbon backbone of the polymer; and having the formula: ##STR3## wherein: x represents the relative number of alkyl acrylate groups with R being 1 to 6 carbon atoms as component (b); y represents the relative number of olefinically-unsaturated carboxylic acid groups with R' being the hydrocarbon portion of the carboxylic acid compounds of component (a); z represents the relative number of crosslinking agents of component (c) with R" being hydrogen or methyl and R"' comprising the remaining portion of component (c).
Claim 8
Dependent Claim
209 words
As an article of manufacture, a flexible support adapted for the absorption of water, said support containing a solid, water-swellable, water-insoluble polymer, said polymer comprising the alkaline salt of a polymer prepared from the reaction of materials consisting essentially of (a) from about 15% to about 50% by weight of an olefinically-unsaturated carboxylic acid containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group; (b) from about 49.07% to about 82% by weight of an alkyl acrylate wherein the alkyl group has from 1 to 6 carbon atoms; and (c) from about 0.03% to about 3.0% by weight of a crosslinking agent which are polyunsaturated polymerizable vinyl monomers containing two or more free radical polymerizable ethylenic groups, said crosslinking agent being introduced directly into the carbon-carbon backbone of the polymer; and having the formula: ##STR3## wherein: x represents the relative number of alkyl acrylate groups with R being 1 to 6 carbon atoms as component (b); y represents the relative number of olefinically-unsaturated carboxylic acid groups with R' being the hydrocarbon portion of the carboxylic acid compounds of component (a); z represents the relative number of crosslinking agents of component (c) with R" being hydrogen or methyl and R"' comprising the remaining portion of component (c).
Claim 9
Dependent Claim
32 words
The article of manufacture of claim 6 comprising from about 20% to about 40% by weight of the olefinically-unsaturated carboxylic acid selected from the group consisting of methacrylic acid and acrylic acid.
Claim 10
Dependent Claim
40 words
The article of manufacture of claim 6 wherein up to 8% by weight of the total amount of olefinically-unsaturated carboxylic acid present is replaced with a material selected from the group consisting of itaconic acid, maleic acid and maleic anhydride.
Claim 11
Dependent Claim
32 words
The article of manufacture of claim 6 comprising from 59.02% to about 78% by weight of the alkyl acrylate selected from the group consisting of methyl acrylate, ethyl acrylate and n-butyl acrylate.
Claim 12
Dependent Claim
17 words
The article of manufacture of claim 6 comprising about 0.08% to about 2% by weight crosslinking agent.
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) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |