US4385094A
Expired / Lapsed
US
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Ethylene-vinyl alcohol hollow fiber membrane and method for the production thereof
Assignee: Kuraray Co Ltd
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Filing: 1980-04-21
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Granted: 1983-05-24
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Expires: 2000-04-21
Abstract
Abstract There is provided a hollow fiber membrane of ethylene-vinyl alcohol copolymer which is produced by a process comprising extruding a spinning solution of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethylsulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through a hollow fiber spinneret while a liquid coagulant is introduced into a central aperture of said spinneret, passing the spun fiber through a gaseous atmosphere in a manner such that the fiber is drawn 0.5 to 20 times its extrusion rate and then coagulating said fiber in a coagulating bath at a temperature within the range satisfying the following relationship: when 15</=C</=40, 1/4C+20</=T</=1/4C+57 wherein C denotes the copolymer concentration of the spinning solution (wt. %) and T denotes the coagulation temperature ( DEG C.). The coagulating liquid can be water or a mixture of the same solvent as that of said spinning solution with no less than 20 weight % of water.
Inventors
- 👤 Taku Tanaka
- 👤 Shuzo Yamashita
- 👤 Hirokuni Tanii
- 👤 Akira Kubotsu
- 👤 Syuji Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:42
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/08; B01D71/00; B01D71/06; B01D71/38; B01D71/381; D; D01; D01D; D01D5/00; D01D5/24; D01F; D01F6/00; D01F6/28; D01F6/30; D01F6/34; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
146 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane having a uniform microporous structure with an average pore diameter of 0.1 to 10 microns and a porosity of 60 to 90%, prepared by a process which comprises spinning a spinning solution of 15 to 40 weight percent of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethyl-sulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through an annular nozzle while introducing a coagulating liquid into the central aperture of said nozzle, passing the spun fiber through a gaseous atmosphere so that the fiber is drawn to 0.5 to 20 times its extrusion rate and then coagulating the spun fiber in a coagulation bath at a temperature within the range satisfying the following relationship: when 15≦C≦40, 1/4C+20≦T≦1/4C+57 wherein C is the polymer concentration (weight %) of the spinning solution and T is the coagulation temperature (°C.).
Claim 2
Dependent Claim
146 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane having a uniform microporous structure with an average pore diameter of 0.1 to 10 microns and a porosity of 60 to 90%, prepared by a process which comprises spinning a spinning solution of 15 to 40 weight percent of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethyl-sulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through an annular nozzle while introducing a coagulating liquid into the central aperture of said nozzle, passing the spun fiber through a gaseous atmosphere so that the fiber is drawn to 0.5 to 20 times its extrusion rate and then coagulating the spun fiber in a coagulation bath at a temperature within the range satisfying the following relationship: when 15≦C≦40, 1/4C+20≦T≦1/4C+57 wherein C is the polymer concentration (weight %) of the spinning solution and T is the coagulation temperature (°C.).
Claim 3
Dependent Claim
23 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 wherein the ethylene content ranges from 10 to 90 mole percent.
Claim 4
Dependent Claim
26 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 additionally containing less than about 15 mole percent of at least one copolymerizable monomer.
Claim 5
Dependent Claim
19 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 which is crosslinked before or after spinning.
Claim 6
Dependent Claim
31 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 wherein up to 30 mole percent of the functional hydroxyl groups in the vinyl alcohol units have been acetalized.
Claim 7
Dependent Claim
19 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 having a dense and active surface layer.
Claim 8
Dependent Claim
32 words
An ethylene-vinyl alcohol copolymer hollow fiber membrane as defined in claim 1 having an outside diameter of from about 40 to 3000μ and a membrane thickness of from about 10 to 1000μ.
Claim 9
Independent Claim
129 words
A method for producing an ethylene-vinyl alcohol copolymer uniform microporous hollow fiber membrane which comprises spinning a spinning solution of 15 to 40 weight % of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethyl sulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through an annular nozzle while introducing a coagulating liquid into the central aperture of said nozzle, passing the spun fiber vertically downward through a gaseous atmosphere so that the fiber is drawn to 0.5 to 20 times its extrusion rate and then coagulating the spun fiber in a coagulation bath at a temperature within the range satisfying the following relationship: when 15≦C≦40, 1/4C+20≦T≦1/4C+57 wherein C is the polymer concentration (weight %) of the spinning solution and T is the coagulation temperature (°C.).
Claim 10
Independent Claim
129 words
A method for producing an ethylene-vinyl alcohol copolymer uniform microporous hollow fiber membrane which comprises spinning a spinning solution of 15 to 40 weight % of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethyl sulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through an annular nozzle while introducing a coagulating liquid into the central aperture of said nozzle, passing the spun fiber vertically downward through a gaseous atmosphere so that the fiber is drawn to 0.5 to 20 times its extrusion rate and then coagulating the spun fiber in a coagulation bath at a temperature within the range satisfying the following relationship: when 15≦C≦40, 1/4C+20≦T≦1/4C+57 wherein C is the polymer concentration (weight %) of the spinning solution and T is the coagulation temperature (°C.).
Claim 11
Dependent Claim
50 words
A method as defined in claim 8, wherein said coagulating liquid to be introduced into the central aperture of said nozzle is a solution of water and the same solvent as that of said spinning solution and the water content of the solution is not less than 20 weight %.
Claim 12
Dependent Claim
23 words
A method as defined in claim 8 wherein the spinning solution is maintained at a temperature ranging from 0° C. to 120° C.
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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) | 1986-05-23 | 1986-11-22 | 1987-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-23 | 1990-11-22 | 1991-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-23 | 1994-11-22 | 1995-05-24 | $7700.00 | Window Closed / Lapsed |