Patent US4587168A successfully refreshed from Google Patents.
US4587168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hollow fiber membrane for dialysis
Assignee: Toyobo Co Ltd
•
Filing: 1984-04-05
•
Granted: 1986-05-06
•
Expires: 2004-04-05
Abstract
Abstract A hollow fiber membrane of a cellulose ester for dialysis which has a membrane thickness of less than 20μ, and a yield strength S b (g/filament) after heat-treatment at 80° C. for 20 hours satisfying the following formula (I): 0.90≦S.sub.b /S.sub.a ≦1.10 (I) wherein S a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment, which is suitable for dialysis of body liquids, particularly for dialysis of blood, because it has excellent dialysis performance while keeping excellent storage stability and excellent UFR retention during storage and during the hemodialysis.
Inventors
- 👤 Morio Miyagi
- 👤 Makoto Ohno
- 👤 Masaru Kanaizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:37
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/02; B01D69/08; B01D69/084; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2922; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
A hollow fiber membrane of a cellulose ester for dialysis, said hollow fiber membrane having a membrane thickness of less than 20 ct, and a yield strength S b (g/filament) after heat-treatment at 80° C. for 20 hours satisfying the following formula (I): 0.90≦S b /S a ≦1.10 (I) wherein S a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment, and further wherein the membrane has crimps of a crimp number of 10 to 35 per 10 cm length of the membrane and a crimp amplitude in the range of from 65% of the outer diameter of the hollow fiber membrane to 50μ plus the outer diameter of the hollow fiber membrane.
Claim 2
Dependent Claim
120 words
A hollow fiber membrane of a cellulose ester for dialysis, said hollow fiber membrane having a membrane thickness of less than 20 ct, and a yield strength S b (g/filament) after heat-treatment at 80° C. for 20 hours satisfying the following formula (I): 0.90≦S b /S a ≦1.10 (I) wherein S a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment, and further wherein the membrane has crimps of a crimp number of 10 to 35 per 10 cm length of the membrane and a crimp amplitude in the range of from 65% of the outer diameter of the hollow fiber membrane to 50μ plus the outer diameter of the hollow fiber membrane.
Claim 3
Dependent Claim
29 words
The hollow fiber membrane according to claim 1, wherein the membrane has a membrane thickness of 5 to less than 20μ, and an inner diameter of 100 to 400μ.
References Cited (Backward Citations)
US3057038A
Cited
US3888771A
Cited
US4035459A
Cited
US4322381A
Cited
US4371487A
Cited
US4242411A
Cited
US4297407A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |