US3940469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming hollow fibers
Assignee: Standard Oil Co
•
Filing: 1973-11-26
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Granted: 1976-02-24
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Expires: 1993-11-26
Abstract
Abstract Hollow membrane fibers are formed from a mixture of N-alkoxyalkyl polyamide, polyvinyl alcohol, di(lower alkyl) sulfoxide and water. The fibers are useful for separating chemicals, e.g., aliphatically-unsaturated hydrocarbons, from mixtures containing them.
Inventors
- 👤 Edward F. Steigelmann
- 👤 Robert D. Hughes
- 👤 Joseph Gabor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:37
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; B; B01; B01D; B01D69/00; B01D69/08; B01D71/00; B01D71/06; B01D71/56; C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08J3/097; C08K; C08K5/00; C08K5/36; C08K5/41; C08L; C08L29/00; C08L29/02; C08L29/04; C08L77/00; Y; Y10; Y10S; Y10S524/00; Y10S524/909; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
74 words
A process for forming hollow, semi-permeable membrane fibers which comprises extruding a composition through an annular die at an elevated temperature to from said fibers, said composition consisting essentially of hydrophilic polymer and di(lower alkyl) sulfoxide solvent, said polymer consisting essentially of N-alkoxyalkyl polyamide and sufficient water-soluble polyvinyl alcohol to enhance the hydrophilic properties of the polyamide, said composition having a sufficient amount of water to inhibit degradation of the polymer at elevated temperature.
Claim 2
Dependent Claim
74 words
A process for forming hollow, semi-permeable membrane fibers which comprises extruding a composition through an annular die at an elevated temperature to from said fibers, said composition consisting essentially of hydrophilic polymer and di(lower alkyl) sulfoxide solvent, said polymer consisting essentially of N-alkoxyalkyl polyamide and sufficient water-soluble polyvinyl alcohol to enhance the hydrophilic properties of the polyamide, said composition having a sufficient amount of water to inhibit degradation of the polymer at elevated temperature.
Claim 3
Dependent Claim
28 words
A process for forming hollow, semi-permeable membrane fibers of claim 1 in which the extruding through an annular die is at a temperature of about 60° to 125°C.
Claim 4
Dependent Claim
37 words
A process of claim 2 in which the di(lower alkyl) sulfoxide is dimethyl sulfoxide and the amount of water is about 1 to 30 weight % based on the total weight of the dimethyl sulfoxide and water.
Claim 5
Dependent Claim
32 words
A process of claim 3 in which the polymer has about 30 to 85 weight % of said polyamide and about 15 to 70 weight % polyvinyl alcohol based on their total.
Claim 6
Dependent Claim
25 words
A process of claim 4 in which the dimethyl sulfoxide is about 70 to 400 weight % based on the total polyamide and polyvinyl alcohol.
Claim 7
Dependent Claim
13 words
A process of claim 5 in which the polyamide is an N-methoxymethyl polyamide.
Claim 8
Dependent Claim
96 words
A process for forming hollow, semi-permeable membrane fibers which comprises extruding a composition through an annular die at an elevated temperature to form said fibers, said composition comprising polymer having about 30 to 85 weight percent of N-alkoxyalkyl polyamide and about 15 to 70 weight percent of water-soluble polyvinyl alcohol based on their total, about 70 to 400 weight percent of di(lower alkyl) sulfoxide based on the total weight of the polyamide and polyvinyl alcohol, and about 1 to 30 weight percent of water based on the total weight of the water and di(lower alkyl) sulfoxide.
Claim 9
Dependent Claim
96 words
A process for forming hollow, semi-permeable membrane fibers which comprises extruding a composition through an annular die at an elevated temperature to form said fibers, said composition comprising polymer having about 30 to 85 weight percent of N-alkoxyalkyl polyamide and about 15 to 70 weight percent of water-soluble polyvinyl alcohol based on their total, about 70 to 400 weight percent of di(lower alkyl) sulfoxide based on the total weight of the polyamide and polyvinyl alcohol, and about 1 to 30 weight percent of water based on the total weight of the water and di(lower alkyl) sulfoxide.
Claim 10
Dependent Claim
28 words
A process for forming hollow, semipermeable membrane fibers of claim 7 in which the extruding through an annular die is at a temperature of about 70° to 110°C.
Claim 11
Dependent Claim
14 words
A process of claim 8 in which the di(lower alkyl) sulfoxide is dimethyl sulfoxide.
Claim 12
Dependent Claim
32 words
A process of claim 9 in which the polymer has about 40 to 70 weight % of said polyamide and about 30 to 60 weight % polyvinyl alcohol based on their total.
Claim 13
Dependent Claim
48 words
A process of claim 10 in which there is about 90 to 250 weight % dimethyl sulfoxide based on the total weight % of the polyamide and polyvinyl alcohol, and about 2 to 20 weight % water based on the total weight of the water and dimethyl sulfoxide.
Claim 14
Dependent Claim
13 words
A process of claim 11 in which the polyamide is an N-methoxymethyl polyamide.
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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) | 1979-02-23 | 1979-08-25 | 1980-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-23 | 1983-08-25 | 1984-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-23 | 1987-08-25 | 1988-02-24 | $7700.00 | Window Closed / Lapsed |