US4051086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorption rate of absorbent polymers by treating with glyoxal
Assignee: Hercules LLC
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Filing: 1976-03-25
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Granted: 1977-09-27
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Expires: 1996-03-25
Abstract
Abstract Water-absorbent crosslinked polymers are improved in their wicking capacity by treatment of their surface with glyoxal. The polymer can be a polysaccharide-acrylamide graft copolymer or a polymer or copolymer of acrylamide and/or sodium acrylate or sodium methacrylate.
Inventors
- 👤 Albert Richard Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:23
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; A61L15/22; A61L15/24; C; C08; C08F; C08F251/00; C08F8/00; C08F8/28; Y; Y10; Y10S; Y10S47/00; Y10S47/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
76 words
A method of increasing the water or saline solution absorption rate of a water-insoluble, crosslinked polymer selected from the class consisting of acrylamide homopolymer, copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, homopolymers of sodium acrylate, homopolymers of sodium methacrylate, and polysaccharides grafted with copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, which method comprises applying to the surface of particles of said polymer about 0.2 to 5% by weight of glyoxal.
Claim 2
Independent Claim
76 words
A method of increasing the water or saline solution absorption rate of a water-insoluble, crosslinked polymer selected from the class consisting of acrylamide homopolymer, copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, homopolymers of sodium acrylate, homopolymers of sodium methacrylate, and polysaccharides grafted with copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, which method comprises applying to the surface of particles of said polymer about 0.2 to 5% by weight of glyoxal.
Claim 3
Dependent Claim
33 words
A method according to claim 1 wherein the water-insoluble crosslinked polymer is cellulose having grafted thereto a copolymer of about 10 to 50% acrylamide and 50 to 90% sodium acrylate crosslinked with bis-methylene-bis-acrylamide.
Claim 4
Dependent Claim
22 words
A method according to claim 1 wherein the water-insoluble crosslinked polymer is a copolymer of acrylamide and sodium acrylate crosslinked with methylene-bis-acrylamide.
Claim 5
Independent Claim
121 words
A method of increasing the water or saline solution absorption rate of a water-insoluble, crosslinked polymer selected from the class consisting of acrylamide hompolymer, copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, homopolymers of sodium acrylate, homopolymers of sodium methacrylate, and polysaccharides grafted with copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, which method comprises forming a slurry of particles of the crosslinked polymer in a nonsolvent liquid, adding to said slurry glyoxal in an amount equal to about 0.2 to 2% by weight of the polymer, adjusting the pH of the slurry to about 5.5 to 5.6, removing the polymer from the slurry and drying at about 50 to 75° C. to remove residual slurrying liquid.
Claim 6
Independent Claim
121 words
A method of increasing the water or saline solution absorption rate of a water-insoluble, crosslinked polymer selected from the class consisting of acrylamide hompolymer, copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, homopolymers of sodium acrylate, homopolymers of sodium methacrylate, and polysaccharides grafted with copolymers of acrylamide and a second vinyl monomer copolymerizable therewith, which method comprises forming a slurry of particles of the crosslinked polymer in a nonsolvent liquid, adding to said slurry glyoxal in an amount equal to about 0.2 to 2% by weight of the polymer, adjusting the pH of the slurry to about 5.5 to 5.6, removing the polymer from the slurry and drying at about 50 to 75° C. to remove residual slurrying liquid.
Claim 7
Dependent Claim
33 words
A method according to claim 4 wherein the water-insoluble crosslinked polymer is cellulose having grafted thereto a copolymer of about 10 to 50% acrylamide and 50 to 90% sodium acrylate crosslinked with bis-methylene-bis-acrylamide.
Claim 8
Dependent Claim
22 words
A method according to claim 4 wherein the water-insoluble crosslinked polymer is a copolymer of acrylamide and sodium acrylate crosslinked with methylene-bis-acrylamide.
Claim 9
Dependent Claim
34 words
A method according to claim 4 wherein the water-insoluble crosslinked polymer is guar gum having grafted thereto a copolymer of about 10 to 50% acrylamide and 50 to 90% sodium acrylate crosslinked with methylene-bis-acrylamide.
Claim 10
Dependent Claim
33 words
A method according to claim 4 wherein the water-insoluble crosslinked polymer is starch having grafted thereto a copolymer of about 10 to 50% acrylamide and 50 to 90% sodium acrylate crosslinked with methylene-bis-acrylamide.
Claim 11
Dependent Claim
91 words
An acrylic polymer selected from the class consisting of a. homopolymers of water-soluble acrylic acid salts, b. homopolymers of water-soluble methacrylic acid salts, c. homopolymers of acrylamide, d. copolymers of acrylamide and one of the salts specified in (a) and (b) in any proportion, and e. graft copolymers of a water-insoluble, water wettable polysaccharide, acrylamide and a second vinyl polymer copolymerizable therewith, said acrylic polymer being crosslinked via a divinyl monomer and being in particulate form and having its particle surfaces treated with about 0.2 to 5% by weight of glyoxal.
Claim 12
Dependent Claim
91 words
An acrylic polymer selected from the class consisting of a. homopolymers of water-soluble acrylic acid salts, b. homopolymers of water-soluble methacrylic acid salts, c. homopolymers of acrylamide, d. copolymers of acrylamide and one of the salts specified in (a) and (b) in any proportion, and e. graft copolymers of a water-insoluble, water wettable polysaccharide, acrylamide and a second vinyl polymer copolymerizable therewith, said acrylic polymer being crosslinked via a divinyl monomer and being in particulate form and having its particle surfaces treated with about 0.2 to 5% by weight of glyoxal.
Claim 13
Dependent Claim
46 words
A graft copolymer of cellulose, acrylamide and an acrylic acid salt crosslinked via methylene bis-acrylamide and comprising about 10 to 90% by weight of cellulose, said copolymer being in particulate form and having its particle surfaces treated with about 0.2 to 2% by weight of glyoxal.
Claim 14
Dependent Claim
46 words
A graft copolymer of cellulose, acrylamide and an acrylic acid salt crosslinked via methylene bis-acrylamide and comprising about 10 to 90% by weight of cellulose, said copolymer being in particulate form and having its particle surfaces treated with about 0.2 to 2% by weight of glyoxal.
Claim 15
Dependent Claim
39 words
A copolymer of acrylamide and a water-soluble acrylic acid salt in any proportion, said copolymer being crosslinked via methylene bis-acrylamide, being in particulate form and having its particle surfaces treated with about 0.2 to 2% by weight of glyoxal.
Claim 16
Dependent Claim
39 words
A copolymer of acrylamide and a water-soluble acrylic acid salt in any proportion, said copolymer being crosslinked via methylene bis-acrylamide, being in particulate form and having its particle surfaces treated with about 0.2 to 2% by weight of glyoxal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |