Patent US3983095A successfully refreshed from Google Patents.
US3983095A
Expired / Lapsed
US
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Absorbent fibers and process for their preparation
Assignee: Dow Chemical Co
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Filing: 1973-02-12
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Granted: 1976-09-28
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Expires: 1993-02-12
Abstract
Abstract Water-insoluble, water-swellable fibers adapted to bind aqueous fluids such as body exudates are prepared by spinning fibers from an organic solvent solution of a copolymer of maleic anhydride with suitable vinyl monomers. The copolymer solution also contains a small amount of a polyfunctional cross-linking agent such as a glycol or alkylene diamine which reacts to cross-link the copolymer chains when the fibers are heated and dried. The cross-linked copolymer fibers are then rendered hydrophilic and water-swellable by reaction with ammonia or an alkali metal hydroxide.
Inventors
- 👤 Robert Niles Bashaw
- 👤 Bobby Leroy Atkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
C; C08; C08F; C08F8/00; D; D01; D01F; D01F6/00; D01F6/28; D01F6/36; D01F6/42
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
136 words
A method for the preparation of water-insoluble, water-swellable polymer products which comprises the steps of 1. forming a solution, in an organic solvent, of a copolymer of maleic anhydride with a vinyl monomer copolymerizable therewith, 2. adding to said solution from about 0.25 to 2.5 percent by weight, based on the weight of copolymer present, of a cross-linking agent consisting of a polyfunctional organic compound in which the functional groups are adapted to react with carboxylic acid anhydrides, 3. extruding the solution of copolymer and cross-linking agent into a shaped form, 4. drying and curing the resulting shaped form of copolymer at an elevated temperature of at least about 50 C. for a period of time sufficient to effectuate cross-linking of the copolymer, and 5. reacting the resulting cured product with ammonia or an alkali metal
Claim 2
Independent Claim
136 words
A method for the preparation of water-insoluble, water-swellable polymer products which comprises the steps of 1. forming a solution, in an organic solvent, of a copolymer of maleic anhydride with a vinyl monomer copolymerizable therewith, 2. adding to said solution from about 0.25 to 2.5 percent by weight, based on the weight of copolymer present, of a cross-linking agent consisting of a polyfunctional organic compound in which the functional groups are adapted to react with carboxylic acid anhydrides, 3. extruding the solution of copolymer and cross-linking agent into a shaped form, 4. drying and curing the resulting shaped form of copolymer at an elevated temperature of at least about 50 C. for a period of time sufficient to effectuate cross-linking of the copolymer, and 5. reacting the resulting cured product with ammonia or an alkali metal
Claim 3
Dependent Claim
8 words
A water-insoluble, water-swellable polymer product prepared by the
Claim 4
Dependent Claim
8 words
A water-insoluble, water-swellable polymer product prepared by the
Claim 5
Dependent Claim
25 words
A method according to claim 1 wherein the cross-linking agent is employed in the amount of from about 0.5 to about 2 percent by weight
Claim 6
Dependent Claim
24 words
A method according to claim 1 wherein the vinyl monomer is an olefin, a vinyl aromatic compound, an olefinic acid, a vinyl ether or
Claim 7
Dependent Claim
23 words
A method according to claim 1 wherein the cross-linking agent is an aliphatic polyol, an amino alcohol, an amino phenol or a polyamino
Claim 8
Dependent Claim
13 words
A method according to claim 1 wherein the cured product is reacted with
Claim 9
Dependent Claim
44 words
A method according to claim 1 wherein the cured product is reacted with a solution of alkali metal hydroxide in anhydrous alcohol or with an aqueous solution of alkali metal hydrodixe containing a sufficient concentration of said hydroxide to prevent substantial swelling of the
Claim 10
Dependent Claim
12 words
A method according to claim 1 wherein the cured product is reacted
Claim 11
Dependent Claim
12 words
A method according to claim 1 wherein the solution of copolymer and
Claim 12
Dependent Claim
12 words
A method according to claim 9 wherein the coagulation bath liquid is
Claim 13
Dependent Claim
13 words
A method according to claim 4 wherein the vinyl monomer is styrene or
Claim 14
Dependent Claim
12 words
A method according to claim 11 wherein the cross-linkg agent is an
Claim 15
Dependent Claim
13 words
A method according to claim 12 wherein the vinyl monomer is styrene and
Claim 16
Dependent Claim
12 words
A method according to claim 12 wherein the vinyl monomer is isobutylene
Claim 17
Dependent Claim
65 words
As an article of manufacture a water-insoluble, water-swellable polymeric fiber composed of the ammonium or alkali metal salt form of a copolymer of maleic anhydride with a vinyl monomer copolymerizable therewith, said copolymer having been cross-linked by reaction with from about 0.25 to 2.5 percent by weight of the copolymer of a polyfunctional organic compound in which the functional groups are adapted to react with
Claim 18
Dependent Claim
65 words
As an article of manufacture a water-insoluble, water-swellable polymeric fiber composed of the ammonium or alkali metal salt form of a copolymer of maleic anhydride with a vinyl monomer copolymerizable therewith, said copolymer having been cross-linked by reaction with from about 0.25 to 2.5 percent by weight of the copolymer of a polyfunctional organic compound in which the functional groups are adapted to react with
Claim 19
Dependent Claim
23 words
An article according to claim 15, wherein the copolymer is a copolymer of maleic anhydride and styrene cross-linked by reaction with an aliphatic
Claim 20
Dependent Claim
11 words
An article according to claim 16 wherein the aliphatic polyol is
Claim 21
Dependent Claim
22 words
An article according to claim 15 wherein the copolymer is a copolymer of maleic anhydride and isobutylene cross-linked by reaction with an
Claim 22
Dependent Claim
13 words
An article according to claim 18 wherein the aliphatic polyol is diethylene glycol.
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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) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |