US3799355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dialysis membranes and manufacture
Assignee: United States Department of Health and Human Services
•
Filing: 1970-12-28
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Granted: 1974-03-26
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Expires: 1990-12-28
Abstract
Abstract Non-thrombogenic hemodialysis flat membranes useful in artificial kidneys are prepared from quaternized membranes of polymers made from monomeric substances of which at least a sufficient amount of a vinylpyridine is included to provide membranes which on heparinization are non-thrombogenic particularly polymers made from monomeric substances of which from 2 to 10 percent by weight of the total monomer is a vinylpyridine and at least 80 percent by weight is acrylonitrile. Both copolymers and blends of polymers can be used. A novel process is described for making the quaternized membranes.
Inventors
- 👤 I Salyer
- 👤 D Bump
- 👤 W Weesner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:53
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/08; B01D71/00; B01D71/06; B01D71/40; B01D71/42; B01D71/421
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
11 words
A process of claim 1 wherein the solvent is dimethyl acetamide.
Claim 2
Dependent Claim
10 words
A process of claim 1 wherein the non-solvent is water.
Claim 3
Dependent Claim
12 words
A process of claim 1 wherein the quaternizing agent is benzyl chloride.
Claim 4
Dependent Claim
10 words
The hemodialysis membrane produced by the process of claim 1.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |