US5431817A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bleach resistant polysulfone/polyurethane composite membranes
Assignee: WR Grace and Co Conn
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Filing: 1993-09-13
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Granted: 1995-07-11
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Expires: 2013-09-13
Abstract
Abstract The resistance to an oxidizer of a biocompatible polysulfone membrane can be enhanced by the incorporation of a specific hydrophilic polyurethane polymer.
Inventors
- 👤 James A. Braatz
- 👤 Denise A. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:48
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/66; B01D71/68; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D67/00111; B01D67/00113; B01D69/00; B01D69/08; B01D69/087; B01D69/0871; B01D2323/00; B01D2323/12; B01D2323/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
88 words
A substantially protein non-adsorptive polysulfone membrane having enhanced resistance to an oxidizer comprising: (a) a polysulfone polymer; (b) a polyurethane polymer prepared by reacting water with a prepolymer prepared from (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units; (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole; and (iii) methylene bis (4,4'cyclohexyl isocyanate); and (c) a pore-forming agent.
Claim 2
Dependent Claim
88 words
A substantially protein non-adsorptive polysulfone membrane having enhanced resistance to an oxidizer comprising: (a) a polysulfone polymer; (b) a polyurethane polymer prepared by reacting water with a prepolymer prepared from (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units; (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole; and (iii) methylene bis (4,4'cyclohexyl isocyanate); and (c) a pore-forming agent.
Claim 3
Dependent Claim
15 words
The membrane of claim 1 wherein the diol contains at least 80% by weight polyoxyethylene.
Claim 4
Dependent Claim
14 words
The membrane of claim 1 wherein the diol contains substantially 100% by weight polyoxyethylene.
Claim 5
Dependent Claim
12 words
The membrane of claim 1 wherein the crosslinking agent is trimethylol propane.
Claim 6
Dependent Claim
9 words
The membrane of claim 1 further comprising polyethylene glycol.
Claim 7
Dependent Claim
18 words
The membrane of claim 1 in which said pore-forming component is selected from alkanols, polyols, polyglycols or cycloketones.
Claim 8
Dependent Claim
20 words
The membrane of claim 1 in which said pore-forming component is methanol, t-butanol, acetone, cyclododecanone, 4-hydroxybutyric acid or polyethylene glycol.
Claim 9
Dependent Claim
25 words
The membrane of claim 1 further comprising a non-solvent for polysulfone which comprises water, methanol, ethanol, propanol, butanol, ethylene glycol, acetone or methyl ethyl ketone.
Claim 10
Dependent Claim
15 words
The membrane of claim 1, which is a microporous or ultrafiltration polysulfone hollow fiber membrane.
Claim 11
Dependent Claim
18 words
The membrane of claim 1, wherein the oxidizer is hydrogen peroxide, peracetic acid, sodium hypochlorite, or mixtures thereof.
Claim 12
Independent Claim
87 words
A method of improving the oxidative degradation resistance of a substantially protein non-adsorptive polysulfone membrane, by incorporating into the membrane a prepolymer prepared from (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units; (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole; and (iii) methylene bis(4,4'cyclohexyl isocyanate), and reacting said prepolymer with water to form a polyurethane polymer.
Claim 13
Independent Claim
87 words
A method of improving the oxidative degradation resistance of a substantially protein non-adsorptive polysulfone membrane, by incorporating into the membrane a prepolymer prepared from (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units; (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole; and (iii) methylene bis(4,4'cyclohexyl isocyanate), and reacting said prepolymer with water to form a polyurethane polymer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-10 | 1999-01-09 | 1999-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-10 | 2003-01-09 | 2003-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-10 | 2007-01-09 | 2007-07-11 | $7700.00 | Window Closed / Lapsed |