US4366206A
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Novel water-swellable fibers having a high degree of water-swellability and excellent physical properties and process for producing the same
Assignee: Japan Exlan Co Ltd
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Filing: 1981-08-24
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Granted: 1982-12-28
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Expires: 2001-08-24
Abstract
Abstract Novel water-swellable fibers having a multiple layer structure consisting of an hydrogel outer layer and an inner layer of an acrylonitrile polymer and/or another polymer, which combine a high degree of water-swellability with excellent physical properties, and a process for producing the same.
Inventors
- 👤 Koji Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:37
CPC Classifications
D; D01; D01F; D01F11/00; D01F11/04; D01F11/06; A; A61; A61C; A61C9/00; A61C9/0033; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; A61F; A61F13/00; A61F13/15; A61F13/51; A61F2013/51002; A61F13/53; A61F2013/530481; A61F2013/530489; A61F2013/530496; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2929; Y10T428/2933; Y10T428/2964; Y10T428/2967; Y10T428/2973; Y10T428/2978
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
109 words
Water-swellable fibers with a high degree of swellability composed of an outer layer of a hydrophilic crosslinked polymer and an inner layer of an acrylonitrile polymer, such fiber being produced by contacting acrylonitrile fibers with an aqueous solution of an alkali-metal hydroxide of a high concentration not less than 6.0 mol/1000 g, or an aqueous solution of an alkali-metal hydroxide of a low concentration coexisting with an electrolytic salt of a concentration not less than 0.5 mol/1000 g for a sufficient time to cross-link and render the outer layer of the fibers hydrophilic, thereby producing fibers having said hydrophilic cross-linked outer layer and a non-cross-linked, non-hydrophilic acrylonitrile inner layer.
Claim 2
Dependent Claim
109 words
Water-swellable fibers with a high degree of swellability composed of an outer layer of a hydrophilic crosslinked polymer and an inner layer of an acrylonitrile polymer, such fiber being produced by contacting acrylonitrile fibers with an aqueous solution of an alkali-metal hydroxide of a high concentration not less than 6.0 mol/1000 g, or an aqueous solution of an alkali-metal hydroxide of a low concentration coexisting with an electrolytic salt of a concentration not less than 0.5 mol/1000 g for a sufficient time to cross-link and render the outer layer of the fibers hydrophilic, thereby producing fibers having said hydrophilic cross-linked outer layer and a non-cross-linked, non-hydrophilic acrylonitrile inner layer.
Claim 3
Dependent Claim
18 words
The fibers as claimed in claim 1 having a degree of water-swellability of from 3 to 300 cc/g.
Claim 4
Dependent Claim
32 words
The fibers as claimed in claim 1 wherein the outer layer composed of a hydrophilic cross-linked polymer constitutes a volume not more than 55% based on the total volume of the fibers.
Claim 5
Dependent Claim
53 words
The fibers as claimed in claim 1 characterized by using, as the aqueous solution of an alkali-metal hydroxide of a low concentration, an aqueous solution of an alkali-metal hydroxide of a concentration of 0.25 to 6.0 mol/1000 g in which an electrolytic salt of a concentration not less than 0.5 mol/1000 g coexists.
Claim 6
Dependent Claim
34 words
The fibers as claimed in claim 1 wherein 0.1 to 4.0 m mol/g of salt-type carboxyl groups represented by --COOX, wherein x is an alkali-metal or NH 4 , is introduced into the fibers.
Claim 7
Dependent Claim
28 words
The fibers as claimed in claim 1 wherein as the electrolytic salt, a salt of which the cationic component is an alkali-metal or NH 4 , is used.
Claim 8
Dependent Claim
29 words
The fibers as claimed in claim 1 wherein an aqueous solution of an alkali-metal hydroxide is contacted within the acrylonitrile fibers at a temperature not lower than 50° C.
Claim 9
Dependent Claim
29 words
The fibers as claimed in claim 1 wherein an aqueous solution of an alkali-metal hydroxide is contacted within the acrylonitrile fibers for a time not more than 40 minutes.
Claim 10
Dependent Claim
61 words
Water-swellable fibers with a high degree of swellability of from 3 to 300 cc/g which consists essentially of an outer layer of a hydrophilic carbon-carbon covalent bonded cross-linked acrylonitrile polymer containing 0.1 to 4.0 m mol/g fiber of salt-type carboxyl groups represented by --COOX, wherein X is an alkali-metal or NH 4 , and an inner layer of an acrylonitrile polymer.
Claim 11
Dependent Claim
61 words
Water-swellable fibers with a high degree of swellability of from 3 to 300 cc/g which consists essentially of an outer layer of a hydrophilic carbon-carbon covalent bonded cross-linked acrylonitrile polymer containing 0.1 to 4.0 m mol/g fiber of salt-type carboxyl groups represented by --COOX, wherein X is an alkali-metal or NH 4 , and an inner layer of an acrylonitrile polymer.
Claim 12
Dependent Claim
31 words
The fibers as in claim 9 wherein the outer layer composed of a hydrophilic cross-linked polymer constitutes a volume not more than 55% based on the total volume of the fibers.
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) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |