US4045387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Highly absorbent polymeric compositions derived from flour
Assignee: United States Department of Agriculture
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Filing: 1976-07-26
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Granted: 1977-08-30
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Expires: 1996-07-26
Abstract
Abstract Absorbent polymeric compositions are prepared by graft polymerizing acrylonitrile onto flour or other starch-containing substrates and then subjecting the flour-polyacrylonitrile graft copolymers to alkaline saponification. Compositions prepared from gelatinized flour absorb from 1800-3000 times their weight of deionized water.
Inventors
- 👤 George F. Fanta
- 👤 William M. Doane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:44
CPC Classifications
F; F16; F16H; F16H55/00; F16H55/02; F16H55/08; F16H55/0886; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; C; C08; C08F; C08F251/00; C08F8/00; C08F8/44; Y; Y10; Y10S; Y10S47/00; Y10S47/10; Y10S524/00; Y10S524/922
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
141 words
A method of preparing water-insoluble, aqueous fluid-absorbing compositions comprising the following steps: a. graft polymerizing acrylontrile onto a starch-containing substrate to form a starch-containing substrate-polyacrylonitrile (SCS-PAN) graft copolymer, wherein said starch-containing substrate is selected from the group consisting of flours and meals, and wherein the weight ratio of said substrate to said acrylonitrile is in the range of 75:25 to 25:75; b. saponifying the SCS-PAN graft copolymer from step (a) in an aqueous slurry with an alkali in amounts such that the molar ratio of alkali to the acrylonitrile repeating unit of said SCS-PAN graft copolymer is from about 0.1:1 to about 7:1 to form a water-soluble saponified graft copolymer (SCS-HPAN); and c. drying said water-soluble SCS-HPAN from step (b) to a moisture level in the range of about 1 to 15% water by weight, whereby said SCS-HPAN is rendered water-insoluble.
Claim 2
Independent Claim
141 words
A method of preparing water-insoluble, aqueous fluid-absorbing compositions comprising the following steps: a. graft polymerizing acrylontrile onto a starch-containing substrate to form a starch-containing substrate-polyacrylonitrile (SCS-PAN) graft copolymer, wherein said starch-containing substrate is selected from the group consisting of flours and meals, and wherein the weight ratio of said substrate to said acrylonitrile is in the range of 75:25 to 25:75; b. saponifying the SCS-PAN graft copolymer from step (a) in an aqueous slurry with an alkali in amounts such that the molar ratio of alkali to the acrylonitrile repeating unit of said SCS-PAN graft copolymer is from about 0.1:1 to about 7:1 to form a water-soluble saponified graft copolymer (SCS-HPAN); and c. drying said water-soluble SCS-HPAN from step (b) to a moisture level in the range of about 1 to 15% water by weight, whereby said SCS-HPAN is rendered water-insoluble.
Claim 3
Dependent Claim
26 words
The method as defined in claim 1 wherein the weight ratio of said starch-containing substrate to said acrylonitrile is in the range of 60:40 to 40:60.
Claim 4
Dependent Claim
23 words
The method as defined in claim 1 wherein said starch-containing substrate selected from the group consisting of flours and meals comprises granular starch.
Claim 5
Dependent Claim
23 words
The method as defined in claim 1 wherein said starch-containing substrate selected from the group consisting of flours and meals comprises gelatinized starch.
Claim 6
Dependent Claim
33 words
The method as defined in claim 1 wherein said starch-containing substrate is selected from the group consisting of yellow corn flour, bleached pregelatinized corn flour, soft wheat flour, and whole ground corn meal.
Claim 7
Dependent Claim
75 words
Aqueous fluid-absorbing compositions comprising water-insoluble alkali salts of saponified starch-containing substrate-polyacrylonitrile (SCS-HPAN) graft copolymers, wherein said starch-containing substrate is selected from the group consisting of flours and meals, and wherein the weight ratio of said substrate to said acrylonitrile is in the range of 75:25 to 25:75, said SCS-HPAN graft copolymers being further characterized as water-insoluble solids capable of absorbing up to about 3000 parts of water by weight per part of said water-insoluble solids.
Claim 8
Dependent Claim
75 words
Aqueous fluid-absorbing compositions comprising water-insoluble alkali salts of saponified starch-containing substrate-polyacrylonitrile (SCS-HPAN) graft copolymers, wherein said starch-containing substrate is selected from the group consisting of flours and meals, and wherein the weight ratio of said substrate to said acrylonitrile is in the range of 75:25 to 25:75, said SCS-HPAN graft copolymers being further characterized as water-insoluble solids capable of absorbing up to about 3000 parts of water by weight per part of said water-insoluble solids.
Claim 9
Dependent Claim
26 words
The composition as defined in claim 6 wherein the weight ratio of said starch-containing substrate to said acrylonitrile is in the range of 60:40 to 40:60.
Claim 10
Dependent Claim
23 words
The composition as defined in claim 6 wherein said starch-containing substrate selected from the group consisting of flours and meals comprises granular starch.
Claim 11
Dependent Claim
23 words
The composition as defined in claim 6 wherein said starch-containing substrate selected from the group consisting of flours and meals. comprises gelatinized starch.
Claim 12
Dependent Claim
33 words
The composition as defined in claim 6 wherein said starch-containing substrate is selected from the group consisting of yellow corn flour, bleached pregelatinized corn flour, soft wheat flour, and whole ground corn meal.
References Cited (Backward Citations)
US3661815A
Cited
US3935099A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |