US5266197A
Expired / Lapsed
US
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Hollow fiber membrane for blood purification
Assignee: Toyobo Co Ltd
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Filing: 1993-04-06
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Granted: 1993-11-30
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Expires: 2013-04-06
Abstract
Abstract A hollow fiber membrane suitable for blood purification is provided, which is durable to γ-ray sterilization and steam sterilization and is not deteriorated by the heat sterilization and which has an excellent capacity for dialysis. The membrane is made of a polyamidimide having a particular structure and has micropores having a mean pore radius of from 10 Å to 200 Å.
Inventors
- 👤 Jitsumi Takata
- 👤 Isamu Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:43
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; B01D71/641
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
A membrane for blood purification, which has polyamidimide units of the following general formula (1), which has a mean molecular weight (Mn) of from 10000 to 80000 and which has micropores having a pore radius of from 10 Å to 200 Å: ##STR4## wherein R 1 and R 2 each represent a hydrogen atom and/or an alkyl group having from 1 to 4 carbon numbers; X represents a bonding group of O, CO, SO 2 or CR 3 .R 4 ; R 3 and R 4 each represent a hydrogen atom or a methyl group; and n represents 0 or 1.
Claim 2
Dependent Claim
101 words
A membrane for blood purification, which has polyamidimide units of the following general formula (1), which has a mean molecular weight (Mn) of from 10000 to 80000 and which has micropores having a pore radius of from 10 Å to 200 Å: ##STR4## wherein R 1 and R 2 each represent a hydrogen atom and/or an alkyl group having from 1 to 4 carbon numbers; X represents a bonding group of O, CO, SO 2 or CR 3 .R 4 ; R 3 and R 4 each represent a hydrogen atom or a methyl group; and n represents 0 or 1.
Claim 3
Dependent Claim
127 words
The membrane for blood purification as claimed in claim 1, which is obtained by reaction of an acid component containing a trimellitic anhydride of the following formula (2) in an amount of 60 mol% or more to the whole acid component and a diisocyanate component containing an isocyanate compound of the following general formula (3) in an amount of 60 mol% or more to the whole isocyanate components: ##STR5## wherein R 1 and R 2 each represent a hydrogen atom and/or an alkyl group having from 1 to 4 carbon numbers; X represents a bonding group of O, CO, SO 2 or CR 3 .R 4 ; R 3 and R 4 each represent a hydrogen atom or a methyl group; and n represents 0 or 1.
Claim 4
Dependent Claim
63 words
The membrane for blood purification as claimed in claim 2, in which the diisocyanate component of the formula (3) comprises bitolylene diisocyanate (Xn=O, R 1 and R 2 are CH 3 in formula (3)) and diphenylmethane diisocyanate (Xn=CH 2 , R 1 and R 2 are H in formula (3)) in a molar ratio of bitolylene diisocyanate/diphenylmethane diisocyanate being from 100/0 to 60/40.
Claim 5
Dependent Claim
31 words
The membrane for blood purification as claimed in claim 2, in which the diisocyanate component contains at most 30 mol% of tolylene diisocyanate to the diisocyanate component of the formula (3).
Claim 6
Dependent Claim
36 words
The membrane for blood purification as claimed in claim 1 or 2, which has a porosity of the micropores having a pore radius of from 10 Å to 200 Å of being from 70 to 90%.
Claim 7
Dependent Claim
78 words
The membrane for blood purification as claimed in claim 1 or 2, which has a ratio (α value) of the water permeation rate with blood to that with pure water of being 0.1 or more, preferably 0.2 or more, and has a percentage (C value) of the water permeation rate after dialysis of blood with it for 60 minutes to that after dialysis of blood with it for 15 minutes being 50% or more, preferably 70% or more.
Claim 8
Dependent Claim
37 words
The membrane for blood purification as claimed in claim 1 or 2, which has a variation of the water permeability being 40% or less before and after steaming treatment of it at 121° C. for 20 minutes.
Claim 9
Dependent Claim
20 words
The membrane for blood purification as claimed in anyone of claims 1 to 8, which is a hollow fiber membrane.
References Cited (Backward Citations)
US4326960A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-29 | 1997-05-31 | 1997-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-29 | 2001-05-31 | 2001-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-29 | 2005-05-31 | 2005-11-30 | $7700.00 | Window Closed / Lapsed |