US4176070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-permeable membranes of regenerated cuprammonium cellulose and method for heat sterilization thereof in physiological saline
Assignee: Kuraray Co Ltd
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Filing: 1978-03-15
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Granted: 1979-11-27
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Expires: 1998-03-15
Abstract
Abstract Semi-permeable membranes of regenerated cellulose are subjected to wet-heat sterilization at a temperature of 105° to 140° C. During the treatment, the membranes are maintained in contact with an aqueous medium such as water or physiological saline. For the dialysis of body fluids, hollow fiber, semi-permeable membranes so sterilized exhibit a sonic modulus of at least 6.5×10 10 dynes/cm 2 . Hollow fibers made of cuprammonium regenerated cellulose are particularly preferred for the above purpose.
Inventors
- 👤 Yutaka Sakurada
- 👤 Kimihisa Sunahara
- 👤 Kazuhisa Yamauchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:52
CPC Classifications
A; A61; A61L; A61L2/00; A61L2/02; A61L2/04; A61L2/06; A61L2/07; B; B01; B01D; B01D65/00; B01D65/02; B01D65/022; B01D2321/00; B01D2321/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
34 words
A method for sterilizing a semi-permeable membrane of regenerated cuprammonium cellulose which comprises subjecting said semi-permeable membrane to heat treatment at a temperature of 105° to 140° C. in the presence of physiological saline.
Claim 2
Independent Claim
34 words
A method for sterilizing a semi-permeable membrane of regenerated cuprammonium cellulose which comprises subjecting said semi-permeable membrane to heat treatment at a temperature of 105° to 140° C. in the presence of physiological saline.
Claim 3
Dependent Claim
25 words
A method as set forth in claim 1 wherein said heat treatment is conducted at a temperature in the range of 110° to 130° C.
Claim 4
Dependent Claim
17 words
A method as set forth in claim 2 wherein said semi-permeable membrane is a hollow fiber membrane.
Claim 5
Dependent Claim
27 words
A method as set forth in claim 1 wherein the membrane is preliminarily heat treated in physiological saline at a temperature of from 70° to 120° C.
Claim 6
Dependent Claim
23 words
A method as set forth in claim 4 wherein the second heat treatment is conducted at a temperature of 110° to 130° C.
Claim 7
Dependent Claim
38 words
A hollow fiber membrane of regenerated cuprammonium cellulose which has a sonic modulus of at least 6.5×10 10 dynes/cm 2 and has been sterilized at a temperature of 105° to 140° C. in the presence of physiological saline.
Claim 8
Dependent Claim
38 words
A hollow fiber membrane of regenerated cuprammonium cellulose which has a sonic modulus of at least 6.5×10 10 dynes/cm 2 and has been sterilized at a temperature of 105° to 140° C. in the presence of physiological saline.
Claim 9
Dependent Claim
19 words
A sterilized fiber membrane as set forth in claim 6 immersed in sterile physiological saline contained in a housing.
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) | 1982-11-26 | 1983-05-28 | 1983-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-26 | 1987-05-28 | 1987-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-26 | 1991-05-28 | 1991-11-27 | $7700.00 | Window Closed / Lapsed |