Patent US4477598A successfully refreshed from Google Patents.
US4477598A
Expired / Lapsed
US
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High strength nylon blend membranes
Assignee: Puropore Inc
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Filing: 1984-03-02
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Granted: 1984-10-16
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Expires: 2004-03-02
Abstract
Abstract A casting solution of two nylons in formic acid, e.g., high molecular weight extrusion grade Nylon 66 homopolymer [η] about 2 or higher, and nylon multipolymer 66, 610, 6 as a strengthening polymer and gelation promoter, when cast by either the dry or wet phase inversion processes, results in highly unexpected membranes of superior strength, flexibility, and uniformity, suitable for use in microfiltration and ultrafiltration.
Inventors
- 👤 Robert E. Kesting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:08
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/56; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08J3/095; C08L; C08L77/00; B01D2323/00; B01D2323/06; C08J2377/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A high void volume integral microporous membrane formed by the dry phase inversion process consisting essentially of a blend of two nylon polymers cast from a formic acid solution of said polymers, said polymers being in a ratio of from about 1:1 to about 9:1 of high molecular weight crystalline nylon homopolymer to amorphous nylon multipolymer.
Claim 2
Dependent Claim
56 words
A high void volume integral microporous membrane formed by the dry phase inversion process consisting essentially of a blend of two nylon polymers cast from a formic acid solution of said polymers, said polymers being in a ratio of from about 1:1 to about 9:1 of high molecular weight crystalline nylon homopolymer to amorphous nylon multipolymer.
Claim 3
Dependent Claim
11 words
The membrane of claim 1 wherein said ratio is about 4:1.
Claim 4
Dependent Claim
15 words
The membrane of claim 1 wherein said ratio is from about 1.5:1 to about 6:1.
Claim 5
Dependent Claim
49 words
Membrane formed by the dry phase inversion process consisting essentially of a blend of high molecular weight nylon homopolymer and nylon multipolymer in a ratio of from about 1:1 up to about 9:1 cast from a formic acid solution of said nylons followed by evaporation of the formic acid.
Claim 6
Dependent Claim
49 words
Membrane formed by the dry phase inversion process consisting essentially of a blend of high molecular weight nylon homopolymer and nylon multipolymer in a ratio of from about 1:1 up to about 9:1 cast from a formic acid solution of said nylons followed by evaporation of the formic acid.
Claim 7
Dependent Claim
18 words
Membrane according to claim 4 wherein the ratio is from greater than 1.5:1 to less than about 6:1.
Claim 8
Dependent Claim
11 words
Membrane according to claim 5 wherein the ratio is about 4:1.
Claim 9
Dependent Claim
41 words
The membranes of claims 4, 5 or 6 wherein the high molecular weight nylon is an extrusion grade nylon 66 having an intrinsic viscosity of approximately two or greater and the amorphous nylon is a multipolymer of type 66, 610, 6.
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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |