US4415455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reverse osmosis membranes based on hydroxyalkyl methacrylate and methacrylic acid copolymers
Assignee: Rohm and Haas Co
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Filing: 1982-11-09
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Granted: 1983-11-15
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Expires: 2002-11-09
Abstract
Abstract Good salt rejection, flux characteristics and resistance to degradation are obtained with semi-permeable reverse osmosis membranes made by coating a microporous substrate with a copolymer of a hydroxy containing methacrylic ester and methacrylic acid, and cross-linking the copolymer subsequent to deposition on the substrate.
Inventors
- 👤 Peter Osei-Gyimah
- 👤 Peter G. Cartier
- 👤 Paul E. Ellis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:27
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D71/00; B01D71/06; B01D71/40; B01D71/401; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975; Y10T428/31504; Y10T428/31855
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
78 words
A composite material suitable for use as a reverse osmosis membrane comprising a microporous substrate and, supported thereon, a thin, water-permeable desalinizing film, said desalinizing film comprising a copolymer of methacrylic acid and a hydroxy-containing monomer selected from ##STR3## wherein R is alkyl of 1 to 4 carbon atoms or BOH, A and B are alkylene having from 2 to about 4 carbon atoms, and x is 1 or 2, said film crosslinked by acid catalyzed ester formation.
Claim 2
Dependent Claim
78 words
A composite material suitable for use as a reverse osmosis membrane comprising a microporous substrate and, supported thereon, a thin, water-permeable desalinizing film, said desalinizing film comprising a copolymer of methacrylic acid and a hydroxy-containing monomer selected from ##STR3## wherein R is alkyl of 1 to 4 carbon atoms or BOH, A and B are alkylene having from 2 to about 4 carbon atoms, and x is 1 or 2, said film crosslinked by acid catalyzed ester formation.
Claim 3
Dependent Claim
18 words
A composite material as defined by claim 1 wherein the desalinizing film further contains a polyfunctional carboxylic acid.
Claim 4
Dependent Claim
15 words
A composite material as defined by claim 1, wherein said hydroxy-containing monomer is 2-hydroxyethyl methacrylate.
Claim 5
Dependent Claim
16 words
A composite material as defined by claim 1, wherein said microporous substrate is a polysulfone film.
Claim 6
Dependent Claim
17 words
A composite material as defined by claim 1, wherein said microporous substrate is a hollow fiber substrate.
Claim 7
Dependent Claim
108 words
A process for the production of a composite material suitable for use as a reverse osmosis membrane, which comprises applying to a microporous substrate a solution containing an acid catalyst and a copolymer of methacrylic acid and a monomer selected from ##STR4## wherein R is alkyl of from 1 to 4 carbon atoms or BOH, A and B are alkylene of from 2 to about 4 carbon atoms and x is 1 or 2; removing excess solution from said substrate; and heating the coated substrate at a temperature of from about 80° to about 135° C. for a period of at least about 5 minutes to effect cure.
Claim 8
Dependent Claim
108 words
A process for the production of a composite material suitable for use as a reverse osmosis membrane, which comprises applying to a microporous substrate a solution containing an acid catalyst and a copolymer of methacrylic acid and a monomer selected from ##STR4## wherein R is alkyl of from 1 to 4 carbon atoms or BOH, A and B are alkylene of from 2 to about 4 carbon atoms and x is 1 or 2; removing excess solution from said substrate; and heating the coated substrate at a temperature of from about 80° to about 135° C. for a period of at least about 5 minutes to effect cure.
Claim 9
Dependent Claim
29 words
A process as defined by claim 6, wherein said solution further contains a polyfunctional carboxylic acid in an amount of from about 0.05 to about 2 percent by weight.
Claim 10
Dependent Claim
15 words
A process as defined by claim 6, wherein said microporous substrate is a polysulfone film.
Claim 11
Dependent Claim
16 words
A process as defined by claim 6, wherein said microporous substrate is a hollow fiber substrate.
Claim 12
Dependent Claim
121 words
In a process for the purification of a liquid, said process comprising contacting said liquid with a reverse osmosis membrane, applying a pressure in excess of the osmotic pressure of said liquid, retaining impurities on said membrane, and recovering purified liquid, the improvement which comprises the utilization of, as said reverse osmosis membrane, a composite material comprising a microporous substrate and supported thereon a thin, liquid permeable film, said film comprising a copolymer of methacrylic acid and a hydroxy-containing monomer selected from ##STR5## wherein R is alkyl of 1 to 4 carbon atoms or BOH, A and B are alkylene having from 2 to 4 carbon atoms and X is 1 or 2, said film crosslinked by acid catalyzed ester formation.
Claim 13
Dependent Claim
121 words
In a process for the purification of a liquid, said process comprising contacting said liquid with a reverse osmosis membrane, applying a pressure in excess of the osmotic pressure of said liquid, retaining impurities on said membrane, and recovering purified liquid, the improvement which comprises the utilization of, as said reverse osmosis membrane, a composite material comprising a microporous substrate and supported thereon a thin, liquid permeable film, said film comprising a copolymer of methacrylic acid and a hydroxy-containing monomer selected from ##STR5## wherein R is alkyl of 1 to 4 carbon atoms or BOH, A and B are alkylene having from 2 to 4 carbon atoms and X is 1 or 2, said film crosslinked by acid catalyzed ester formation.
Claim 14
Dependent Claim
16 words
A process as defined by claim 10 wherein said film further contains a polyfunctinal carboxylic acid.
Claim 15
Dependent Claim
14 words
A process as defined by claim 10 wherein said hydroxy-containing monomer is 2-hydroxyethyl methacrylate.
Claim 16
Dependent Claim
14 words
A process as defined by claim 11 wherein said hydroxy-containing monomer is 2-hydroxyethyl methacrylate.
Claim 17
Dependent Claim
15 words
A process as defined by claim 10 wherein said microporous substrate is a polysulfone film.
Claim 18
Dependent Claim
15 words
A process as defined by claim 11 wherein said microporous substrate is a polysulfone film.
Claim 19
Dependent Claim
16 words
A process as defined by claim 10 wherein said microporous substrate is a hollow fiber substrate.
Claim 20
Dependent Claim
16 words
A process as defined by claim 11 wherein said microporous substrate is a hollow fiber structure.
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) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |