US4181606A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lactam terpolymer membranes
Assignee: Monsanto Co
•
Filing: 1978-06-06
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Granted: 1980-01-01
•
Expires: 1998-06-06
Abstract
Abstract Permselective membranes are provided consisting of lactam-polyol-polyacyl lactam block terpolymers having from 35 to 75% by weight polylactam blocks and 25 to 65% by weight polyalkylene ether blocks. The membranes are particularly suitable as blood dialysis membranes having improved permeability to solutes in the medium range of molecular weights while maintaining acceptable ultrafiltration rates and permeability to low molecular weight solutes. The membranes are provided both as planar films and hollow fibers, have high hydrolytic stability under hot wet sterilization conditions and good mechanical properties under hemodialysis conditions.
Inventors
- 👤 Joseph A. Carden, Jr.
- 👤 Ray McKinney, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:39
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/44; B; B01; B01D; B01D71/00; B01D71/06; B01D71/56; B01D71/76; B01D71/80
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
125 words
In a process for dialyzing blood wherein whole venous blood is contacted in a hemodialysis apparatus with one surface of a blood dialysis membrane under dialysis conditions, physiological waste products in the blood are permeated through said membrane, and said waste products are taken up in a physiological dialyzate solution in contact with the second surface of said membrane, the improvement comprising using as said blood dialysis membrane a membrane comprising a caprolactam-polyalkylene ether-polyacyl lactam block terpolymer having from 35 to 75 percent by weight polycaprolactam blocks and from 25 to 65 percent by weight polyalkylene ether blocks and adaptable for use in hemodialysis apparatus to preferentially remove from blood medium molecular weight molecules having a molecular weight of from about 300 to about 5000.
Claim 2
Dependent Claim
125 words
In a process for dialyzing blood wherein whole venous blood is contacted in a hemodialysis apparatus with one surface of a blood dialysis membrane under dialysis conditions, physiological waste products in the blood are permeated through said membrane, and said waste products are taken up in a physiological dialyzate solution in contact with the second surface of said membrane, the improvement comprising using as said blood dialysis membrane a membrane comprising a caprolactam-polyalkylene ether-polyacyl lactam block terpolymer having from 35 to 75 percent by weight polycaprolactam blocks and from 25 to 65 percent by weight polyalkylene ether blocks and adaptable for use in hemodialysis apparatus to preferentially remove from blood medium molecular weight molecules having a molecular weight of from about 300 to about 5000.
Claim 3
Dependent Claim
39 words
The process of claim 1 wherein the said blood dialysis membrane comprises a caprolactam-polyalkylene ether-polyacyl lactam block terpolymer having from 40 to 70 percent by weight polycaprolactam blocks and from 30 to 60 percent by weight polyalkylene ether blocks.
Claim 4
Dependent Claim
37 words
The process of claim 1 wherein said polyalkylene ether blocks comprise the polymerized residue of a polyethylene glycol of from about 500 to 10,000 molecular weight from which the terminal hydrogen atoms have been abstracted by reaction.
Claim 5
Dependent Claim
35 words
The process of claim 1 wherein said block terpolymer is at least partially ester group terminated by the residue of a monohydric aliphatic alcohol from which the terminal hydrogen atom has been abstracted by reaction.
Claim 6
Dependent Claim
21 words
The process of claim 4 wherein said monohydric aliphatic alcohol is an end-terminated monohydric alcohol of 4 to 12 carbon atoms.
Claim 7
Dependent Claim
77 words
The process of claim 1 wherein the said polyalkylene ether blocks comprise the residue of polyethylene glycol of a molecular weight of about 1000 to about 8000, said terpolymer being fully ester group terminated and produced by the anhydrous anionic polymerization of caprolactam in the presence of a polyether-polyester prepolymer which is a reaction product of a polyethylene glycol of a molecular weight of from about 1000 to about 8000 and a di-lower alkyl dicarboxylic acid ester.
Claim 8
Dependent Claim
14 words
The process of claim 6 wherein the said di-loweralkyl dicarboxylic acid ester is dimethylterephthalate.
Claim 9
Dependent Claim
18 words
The process of claim 1 wherein the blood dialysis membrane is in the form of a planar film.
Claim 10
Dependent Claim
18 words
The process of claim 1 wherein the blood dialysis membrane is in the form of a hollow fiber.
Claim 11
Dependent Claim
22 words
The process of claim 1 wherein said medium molecular weight molecules have a molecular weight of from about 300 to about 1500.
Claim 12
Dependent Claim
62 words
A blood dialysis membrane comprising a caprolactam-polyalkylene ether-polyacyl lactam block terpolymer having from 35 to 75 percent by weight polycaprolactam blocks and from 25 to 65 percent by weight polyalkylene ether blocks, said membrane being adaptable for use in a hemodialysis apparatus to preferentially remove from blood medium molecular weight molecules having a molecular weight of from about 300 to about 5000.
Claim 13
Dependent Claim
62 words
A blood dialysis membrane comprising a caprolactam-polyalkylene ether-polyacyl lactam block terpolymer having from 35 to 75 percent by weight polycaprolactam blocks and from 25 to 65 percent by weight polyalkylene ether blocks, said membrane being adaptable for use in a hemodialysis apparatus to preferentially remove from blood medium molecular weight molecules having a molecular weight of from about 300 to about 5000.
Claim 14
Dependent Claim
22 words
The membrane of claim 11 wherein said medium molecular weight molecules have a molecular weight of from about 300 to about 1500.
Claim 15
Dependent Claim
37 words
The membrane of claim 11 wherein said polyalkylene ether blocks comprise the polymerized residue of a polyethylene glycol of from about 500 to 10,000 molecular weight from which the terminal hydrogen atoms have been abstracted by reaction.
Claim 16
Dependent Claim
35 words
The membrane of claim 11 wherein said block terpolymer is at least partially ester group terminated by the residue of a monohydric aliphatic alcohol from which the terminal hydrogen atom has been abstracted by reaction.
Claim 17
Dependent Claim
21 words
The membrane of claim 14 wherein said monohydric aliphatic alcohol is an end-terminated monohydric alcohol from 4 to 12 carbon atoms.
Claim 18
Dependent Claim
76 words
The membrane of claim 11 wherein the said polyalkylene ether blocks comprise the residue of a polyethylene glycol of molecular weight of about 1,000 to about 8,000, said terpolymer being fully ester group terminated and produced by the anhydrous anionic polymerization of caprolactam in the presence of a polyether-polyester prepolymer which is the reaction product of a polyethylene glycol of a molecular weight of from about 1,000 to about 8,000 and a di-loweralkyl dicarboxylic acid ester.
Claim 19
Dependent Claim
14 words
The membrane of claim 16 wherein the said di-loweralkyl dicarboxylic acid ester is dimethylterephthalate.
Claim 20
Dependent Claim
12 words
The membrane of claim 11 in the form of a planar film.
Claim 21
Dependent Claim
12 words
The membrane of claim 11 in the form of a hollow fiber.
Claim 22
Dependent Claim
31 words
The membrane of claim 11 wherein the said block terpolymer has from 40 to 70 percent by weight polycaprolactam blocks and from 30 to 60 percent by weight polyalkylene ether blocks.
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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) | 1982-12-31 | 1983-07-02 | 1984-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-31 | 1987-07-02 | 1988-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-31 | 1991-07-02 | 1992-01-01 | $7700.00 | Window Closed / Lapsed |