US3901810A
Expired / Lapsed
US
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Ultrafiltration membranes
Assignee: Calgon Corp
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Filing: 1972-09-21
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Granted: 1975-08-26
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Expires: 1992-09-21
Abstract
Abstract It is disclosed that ultrafiltration membranes may be made from solutions of segmented polymers having distinct hydrophilic portions and hydrophobic portions. A preferred segmented copolymer is one of poly(vinyl pyrrolidone) as the backbone segment with segments of poly (methyl methacrylate) grafted onto it. Other preferred membrane materials of this invention are condensation type random-block copolymers comprised of hydrophilic polyether glycols and hydrophobic dihydric phenol compounds. The membranes may be used in various membrane separation processes.
Inventors
- 👤 Thomas William Brooks
- 👤 David William Gaefke
- 👤 Lawrence James Guilbault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:55
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/76; B01D71/80; B01D71/78; C; C08; C08F; C08F271/00; C08F271/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
66 words
A SEMIPERMEABLE MEMBRANE COMPRISING A SEGMENTED POLYMER OF CHEMICALLY BONDED HYDROPHILIC SEGMENTS AND HYDROPHOBICS SEGMENTS WHEREIN THE HYDROPHILIC SEGMENTS CONSIST ESSENTIALLY OF A COPOLYMER OF POLYVINYL PYRROLIDONE WHICH HAS BEEN PREPARED IN NON-AQUEOUS MEDIUM AND AT LEAST ABOUT 5 MOLE PERCENT OF GRAFT-REACTIVE SITE CONTAINING HYDROPHILIC MONOMER CONSISTING ESSENTIALLY OF N-METHACROLYL-D-GLUCOSAMINE, AND WHEREIN THE HYDROPHOBIC SEGMENTS CONSIST ESSENTIALLY OF POLYMETHYL METHACRYLATE CHEMICALLY BONDED TO THE N-METHACROLYL-D-GLUCOSAMINE.
Claim 2
Dependent Claim
66 words
A SEMIPERMEABLE MEMBRANE COMPRISING A SEGMENTED POLYMER OF CHEMICALLY BONDED HYDROPHILIC SEGMENTS AND HYDROPHOBICS SEGMENTS WHEREIN THE HYDROPHILIC SEGMENTS CONSIST ESSENTIALLY OF A COPOLYMER OF POLYVINYL PYRROLIDONE WHICH HAS BEEN PREPARED IN NON-AQUEOUS MEDIUM AND AT LEAST ABOUT 5 MOLE PERCENT OF GRAFT-REACTIVE SITE CONTAINING HYDROPHILIC MONOMER CONSISTING ESSENTIALLY OF N-METHACROLYL-D-GLUCOSAMINE, AND WHEREIN THE HYDROPHOBIC SEGMENTS CONSIST ESSENTIALLY OF POLYMETHYL METHACRYLATE CHEMICALLY BONDED TO THE N-METHACROLYL-D-GLUCOSAMINE.
Claim 3
Dependent Claim
25 words
The semipermeable membrane of claim 1 wherein the polyvinyl pyrrolidone comprises from about 5 mole percent to about 40 mole percent of the segmented polymer.
Claim 4
Dependent Claim
25 words
The semipermeable membrane of claim 1 wherein the polyvinyl pyrrolidone comprises from about 10 mole percent to about 20 mole percent of the segmented polymer.
Claim 5
Dependent Claim
71 words
A semipermeable membrane comprising a segmented polymer of chemically bonded hydrophilic segments and hydrophobic segments wherein the hydrophilic segments consist essentially of a copolymer of polyvinyl pyrrolidone which has been prepared in aqueous medium and at least 5 mole percent of graft-reactive site containing hydrophilic monomer consisting essentially of N-methacrolyl-D-glucosamine; and wherein the hydrophobic segments consist essentially of polymethyl methacrylate chemically bonded to both the polyvinyl pyrrolidone and to the N-methacrolyl-D-glucosamine.
Claim 6
Dependent Claim
71 words
A semipermeable membrane comprising a segmented polymer of chemically bonded hydrophilic segments and hydrophobic segments wherein the hydrophilic segments consist essentially of a copolymer of polyvinyl pyrrolidone which has been prepared in aqueous medium and at least 5 mole percent of graft-reactive site containing hydrophilic monomer consisting essentially of N-methacrolyl-D-glucosamine; and wherein the hydrophobic segments consist essentially of polymethyl methacrylate chemically bonded to both the polyvinyl pyrrolidone and to the N-methacrolyl-D-glucosamine.
Claim 7
Dependent Claim
25 words
The semipermeable membrane of claim 4 wherein the polyvinyl pyrrolidone comprises from about 5 mole percent to about 40 mole percent of the segmented polymer.
Claim 8
Dependent Claim
25 words
The semipermeable membrane of claim 4 wherein the polyvinyl pyrrolidone comprises from about 10 mole percent to about 20 mole percent of the segmented polymer.
Claim 9
Dependent Claim
130 words
Method of forming a membrane comprising a segmented polymer of chemically bonded hydrophilic segments and hydrophobic segments comprising the following steps: a. forming a linear hydrophilic copolymer of a first hydrophilic monomer which will not itself chemically bond to the hydrophobic portion of the segmented polymer, and a least 5 mole percent of a second hydrophilic monomer having a graft-reactive site, comprising N-methacrolyl-D-glucosamine; b. grafting the hydrophobic polymer segments to the graft-reactive sites comprising N-methacrolyl-D-glucosamine; c. dissolving the segmented copolymer thus formed in a solvent which is a better solvent for the hydrophilic portion of the copolymer than it is for the hydrophobic portion; d. casting the solution on a surface; e. partially evaporating the solvent; and f. gelling the copolymer in a bath which leachs out the remaining solvent.
Claim 10
Dependent Claim
130 words
Method of forming a membrane comprising a segmented polymer of chemically bonded hydrophilic segments and hydrophobic segments comprising the following steps: a. forming a linear hydrophilic copolymer of a first hydrophilic monomer which will not itself chemically bond to the hydrophobic portion of the segmented polymer, and a least 5 mole percent of a second hydrophilic monomer having a graft-reactive site, comprising N-methacrolyl-D-glucosamine; b. grafting the hydrophobic polymer segments to the graft-reactive sites comprising N-methacrolyl-D-glucosamine; c. dissolving the segmented copolymer thus formed in a solvent which is a better solvent for the hydrophilic portion of the copolymer than it is for the hydrophobic portion; d. casting the solution on a surface; e. partially evaporating the solvent; and f. gelling the copolymer in a bath which leachs out the remaining solvent.
Claim 11
Dependent Claim
61 words
A semipermeable membrane comprising a block polymer of two hydrophobic segments chemically bonded to a single hydrophilic segment, wherein the hydrophilic segment consists essentially of poly(vinyl pyrrolidone) which has been prepared in aqueous medium, said segment comprising from about 5 mole percent to about 40 mole percent of the block polymer, and wherein the hydrophobic segments consist essentially of polymethyl methacrylate.
Claim 12
Dependent Claim
61 words
A semipermeable membrane comprising a block polymer of two hydrophobic segments chemically bonded to a single hydrophilic segment, wherein the hydrophilic segment consists essentially of poly(vinyl pyrrolidone) which has been prepared in aqueous medium, said segment comprising from about 5 mole percent to about 40 mole percent of the block polymer, and wherein the hydrophobic segments consist essentially of polymethyl methacrylate.
Claim 13
Dependent Claim
24 words
The membrane of claim 8 wherein the polyvinyl pyrrolidone comprises from about 10 mole percent to aBout 20 mole percent of the block polymer.
References Cited (Backward Citations)
US3723306A
Cited
US3386912A
Cited
US3497573A
Cited
US3719738A
Cited
US3607977A
Cited
US3652724A
Cited
US3675391A
Cited
US3786116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |