Patent US4128692A successfully refreshed from Google Patents.
US4128692A
Expired / Lapsed
US
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Superabsorbent cellulosic fibers having a coating of a water insoluble, water absorbent polymer and method of making the same
Assignee: Hercules LLC
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Filing: 1977-05-25
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Granted: 1978-12-05
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Expires: 1997-05-25
Abstract
Abstract Products having high absorbency for use in absorbent dressings and the like are prepared by precipitating a water-insoluble but water-swellable superabsorbent polymer onto the surface of a long fiber cellulose from an aqueous slurry and drying the resulting coated fibers by dehydration with a water-miscible nonsolvent for the polymer.
Inventors
- 👤 Albert R. Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:43
CPC Classifications
D; D06; D06M; D06M14/00; D06M14/02; D06M14/04; D06M15/00; D06M15/01; D06M15/03; D21; D21C; D21C9/00; D21C9/001; D21C9/002; D21C9/005; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2938
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
77 words
Cellulosic fibers having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions comprising a long fiber cellulose having on its surfaces a coating of water-insoluble, water-absorbent polymer in an amount equal to 15 to 90% by weight based on the total weight of the coated fiber and being in the form of separate and discrete fibers, said coated fibers having a higher absorption capacity than the uncoated long fiber cellulose.
Claim 2
Dependent Claim
77 words
Cellulosic fibers having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions comprising a long fiber cellulose having on its surfaces a coating of water-insoluble, water-absorbent polymer in an amount equal to 15 to 90% by weight based on the total weight of the coated fiber and being in the form of separate and discrete fibers, said coated fibers having a higher absorption capacity than the uncoated long fiber cellulose.
Claim 3
Dependent Claim
109 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a long fiber cellulose in the form of separate and discrete fibers having on their surfaces a coating of water-insoluble, water-absorbent polymer in an amount equal to 15 to 90% by weight based on the total weight of the coated fiber, said water-absorbent polymer being selected from the class consisting of cross-linked sodium carboxymethyl cellulose, cross-linked partial free acid carboxymethyl cellulose, cross-linked hydroxyethyl cellulose, cross-linked cellulose-acrylamide-acrylic acid copolymers and cross-linked acrylamide-acrylic acid copolymer, said coated fiber having a higher absorption capacity than the uncoated long fiber cellulose.
Claim 4
Dependent Claim
109 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a long fiber cellulose in the form of separate and discrete fibers having on their surfaces a coating of water-insoluble, water-absorbent polymer in an amount equal to 15 to 90% by weight based on the total weight of the coated fiber, said water-absorbent polymer being selected from the class consisting of cross-linked sodium carboxymethyl cellulose, cross-linked partial free acid carboxymethyl cellulose, cross-linked hydroxyethyl cellulose, cross-linked cellulose-acrylamide-acrylic acid copolymers and cross-linked acrylamide-acrylic acid copolymer, said coated fiber having a higher absorption capacity than the uncoated long fiber cellulose.
Claim 5
Dependent Claim
15 words
A product according to claim 2 wherein the modified cellulose is an epihalohydrin cross-linked carboxymethylcellulose.
Claim 6
Dependent Claim
15 words
A product according to claim 2 wherein the modified cellulose is partial free acid carboxymethylcellulose.
Claim 7
Dependent Claim
25 words
The product according to claim 2 wherein the long fiber cellulose is selected from the class consisting of wood pulp, chemical cotton and cotton staple.
Claim 8
Dependent Claim
15 words
The product according to claim 2 wherein the long fiber cellulose is rayon staple fiber.
Claim 9
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete staple cotton fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fibers, said coated fiber having a higher absorption capacity than the uncoated staple cotton.
Claim 10
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete staple cotton fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fibers, said coated fiber having a higher absorption capacity than the uncoated staple cotton.
Claim 11
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete wood pulp fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fiber, said coated fiber having a higher absorption capacity than the uncoated wood pulp.
Claim 12
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete wood pulp fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fiber, said coated fiber having a higher absorption capacity than the uncoated wood pulp.
Claim 13
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete chemical cotton fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fiber, said coated fiber having a higher absorption capacity than the uncoated chemical cotton.
Claim 14
Dependent Claim
70 words
A cellulosic fiber having a rapid rate of absorption and a high absorption capacity for water or aqueous salt solutions which comprises a separate and discrete chemical cotton fiber having on its surfaces a coating comprising about 40 to 90% by weight of partial free acid carboxymethyl cellulose based on the total weight of the coated fiber, said coated fiber having a higher absorption capacity than the uncoated chemical cotton.
Claim 15
Dependent Claim
62 words
A blend of an untreated long fiber cellulose and a long fiber cellulose having a higher absorption capacity than said untreated long fiber cellulose comprised of separate and discrete fibers coated with a water-insoluble, water-absorbent polymer and having a ratio of coated to uncoated fibers such that the total concentration of water-insoluble, water-absorbent polymer in the blend is about 15 to 80%.
Claim 16
Dependent Claim
62 words
A blend of an untreated long fiber cellulose and a long fiber cellulose having a higher absorption capacity than said untreated long fiber cellulose comprised of separate and discrete fibers coated with a water-insoluble, water-absorbent polymer and having a ratio of coated to uncoated fibers such that the total concentration of water-insoluble, water-absorbent polymer in the blend is about 15 to 80%.
Claim 17
Independent Claim
117 words
A method of preparing cellulosic fibers having a rapid rate of absorption and a high capacity for water or aqueous salt solutions which comprises preparing an aqueous suspension of separate and discrete long fiber cellulose fibers containing a water-insoluble, water-absorbent polymer, stirring the suspension until the water-insoluble, water-absorbent polymer forms an aqueous gel, adding to the suspension an inert water-miscible diluent in which the polymer is neither soluble nor swellable to precipitate the polymer onto the surface of the long fiber cellulose and thereafter dehydrating the coated fibers by contacting them with a water-miscible diluent in which the polymer is neither soluble nor swellable, removing the diluent and recovering separate and discrete long fiber cellulose fibers therefrom.
Claim 18
Independent Claim
117 words
A method of preparing cellulosic fibers having a rapid rate of absorption and a high capacity for water or aqueous salt solutions which comprises preparing an aqueous suspension of separate and discrete long fiber cellulose fibers containing a water-insoluble, water-absorbent polymer, stirring the suspension until the water-insoluble, water-absorbent polymer forms an aqueous gel, adding to the suspension an inert water-miscible diluent in which the polymer is neither soluble nor swellable to precipitate the polymer onto the surface of the long fiber cellulose and thereafter dehydrating the coated fibers by contacting them with a water-miscible diluent in which the polymer is neither soluble nor swellable, removing the diluent and recovering separate and discrete long fiber cellulose fibers therefrom.
Claim 19
Dependent Claim
24 words
The process of claim 11 wherein the long fiber cellulose is selected from the group consisting of wood pulp, chemical cotton and cotton staple.
Claim 20
Dependent Claim
14 words
The process of claim 12 wherein the water-insoluble, water-absorbent polymer is a modified polysaccharide.
Claim 21
Dependent Claim
10 words
The process of claim 13 wherein the polysaccharide is cellulose.
Claim 22
Dependent Claim
24 words
The process of claim 14 wherein the modified cellulose is selected from the class consisting of epichlorohydrin cross-linked carboxymethylcellulose and partial free acid carboxymethylcellulose.
Claim 23
Dependent Claim
19 words
The process of claim 12 wherein the aqueous suspension is prepared in water containing up to about 50% acetone.
Claim 24
Dependent Claim
33 words
The process according to claim 12 wherein the water-miscible diluent employed to precipitate the polymer onto the cellulose fiber is acetone and water-miscible diluent employed to dehydrate the coated fibers is also acetone.
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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) | 1981-12-04 | 1982-06-05 | 1982-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-04 | 1986-06-05 | 1986-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-04 | 1990-06-05 | 1990-12-05 | $7700.00 | Window Closed / Lapsed |