US4239722A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of hydrophilic fibres
Assignee: Bayer AG
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Filing: 1977-12-09
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Granted: 1980-12-16
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Expires: 1997-12-09
Abstract
Abstract The invention relates to a process for the production of hydrophilic filaments and fibers from filament-forming synthetic polymers by spinning a solution which, in addition to a suitable solvent, contains from 5 to 50% by weight, based on the solvent and solids, of a substance which is essentially a non-solvent for the polymer, has a higher boiling point than the solvent used and is readily miscible with the spinning solvent and with a liquid suitable as a washing liquid for the filaments, and subsequently washing this substance out of the filaments, wherein a suspension is initially prepared at room temperature from the solvent, the polymer and the substance, the suspension thus prepared is subsequently heated, left for at least one minute and at most 15 minutes at a temperature of at least 30° C. and of at most 60° C. above the temperature at which the suspension becomes optically homogeneous, spinning the solution to form filaments or fibers and washing the said substance out of the filaments or fibers.
Inventors
- 👤 Ulrich Reinehr
- 👤 Herman-Josef Jungverdorben
- 👤 Toni Herbertz
- 👤 Joachim Dross
- 👤 Rolf-Burkhard Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:44
CPC Classifications
D; D01; D01F; D01F1/00; D01F1/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
175 words
In the process of producing hydrophilic filaments or fibers by dry spinning a solution comprising a solvent consisting essentially of dimethyl formamide, 19 to 40 by weight of a filament forming synthetic polymer containing at least 50 percent acrylonitrile units and from 5 to 50 percent by weight based on the solvent and polymer, of a substance which is essentially a non-solvent for the polymer and has a higher boiling point than the solvent used and is readily miscible with the solvent and with a liquid suitable as a washing liquid for the filaments or fibers to form filaments or fibers, and washing the said substance out of the filaments or fibers; the improvement comprising preparing a suspension of said constituents of the spinning solution, heating the suspension and leaving it for a period of from 1 to 15 minutes at a temperature of from 30° C. to 60° C. above the temperature at which the suspension becomes optically homogeneous and thereafter dry-spinning the solution and washing said substance out of the filaments or fibers.
Claim 2
Dependent Claim
175 words
In the process of producing hydrophilic filaments or fibers by dry spinning a solution comprising a solvent consisting essentially of dimethyl formamide, 19 to 40 by weight of a filament forming synthetic polymer containing at least 50 percent acrylonitrile units and from 5 to 50 percent by weight based on the solvent and polymer, of a substance which is essentially a non-solvent for the polymer and has a higher boiling point than the solvent used and is readily miscible with the solvent and with a liquid suitable as a washing liquid for the filaments or fibers to form filaments or fibers, and washing the said substance out of the filaments or fibers; the improvement comprising preparing a suspension of said constituents of the spinning solution, heating the suspension and leaving it for a period of from 1 to 15 minutes at a temperature of from 30° C. to 60° C. above the temperature at which the suspension becomes optically homogeneous and thereafter dry-spinning the solution and washing said substance out of the filaments or fibers.
Claim 3
Dependent Claim
13 words
The process of claim 1, wherein said solution is spun without intermediate cooling.
Claim 4
Dependent Claim
14 words
The process of claim 1, wherein said substance added is glycerol or tetraethylene glycol.
Claim 5
Dependent Claim
21 words
The process of claim 1, wherein said polymer is an acrylonitrile polymer containing at least 50% by weight of acrylonitrile units.
Claim 6
Dependent Claim
21 words
A process according to claim 5 wherein said spinning solution consists essentially of said dimethyl formamide, said substance and said polymer.
Claim 7
Dependent Claim
12 words
A process according to claim 5 wherein said substance is a solid.
Claim 8
Dependent Claim
34 words
A process according to claim 6 wherein said solid is a monohydric, a polyhydric alcohol, an ester, a ketone, an inorganic acid, an organic acid, an inorganic salt, an organic salt or a sugar.
Claim 9
Dependent Claim
26 words
A process according claim 7 wherein said solid is 1,6-hexane diol, p-hydroxy benzoic acid methyl ester, isophthalic acid, pyromellitic acid, zinc chloride, magnesium chloride or DL-sorbose.
Claim 10
Dependent Claim
12 words
A process according to claim 5 wherein said substance is a liquid.
Claim 11
Dependent Claim
31 words
A process according to claim 9 wherein said liquid is a mono-substituted or poly-substituted alkyl ether or ester of a polyhydric alcohol an ester or a ketone or high boiling alcohol.
Claim 12
Dependent Claim
24 words
A process according to claim 10 wherein said liquid substance is glycerol, diethylene glycol, triethylene glycol, triethylene glycol diacetate, tetraethylene glycol, glycol ether acetate.
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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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |