US4595707A
Expired / Lapsed
US
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Membranes comprising microporous structure
Assignee: Dow Chemical Co
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Filing: 1985-02-11
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Granted: 1986-06-17
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Expires: 2005-02-11
Abstract
Abstract Membrane compositions useful in filtration and distillation applications are prepared by providing a glassy polymer composition (e.g., polystyrene) optionally having an amount of crosslinking and crazing the polymer composition in the presence of a monomer (e.g., methyl methacrylate) which can graft to said polymer composition. The membrane compositions so prepared comprise a microporous structure wherein the micropores can contain polymeric material. Alternatively, the surface region of the membrane composition and/or the surface region of the micropores has a polymeric material grafted thereto.
Inventors
- 👤 Kathleen M. McCreedy
- 👤 Edward J. Kramer
- 👤 Lu H. Tung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:43
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D67/0002; B01D67/0023; B01D69/00; B01D69/02; C; C08; C08J; C08J7/00; C08J7/12; C08J7/16; B01D2323/00; B01D2323/08; B01D2323/081; B01D2323/30; B01D2325/00; B01D2325/02; B01D2325/022; B01D2325/0233
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
95 words
A process for providing a polymer composition suitable for use as a membrane composition, said polymer composition comprising at least one region having a microporous structure, said process comprising (a) providing a glassy polymer composition optionally having a functionally effective amount of crosslinking, and (b) providing said membrane composition by crazing the glassy polymer composition in an amount sufficient to provide to the glassy polymer composition at least one microporous domain, wherein (c) said glassy polymer composition is crazed in the presence of monomers which graft polymerize with said glassy polymer composition during said crazing.
Claim 2
Dependent Claim
95 words
A process for providing a polymer composition suitable for use as a membrane composition, said polymer composition comprising at least one region having a microporous structure, said process comprising (a) providing a glassy polymer composition optionally having a functionally effective amount of crosslinking, and (b) providing said membrane composition by crazing the glassy polymer composition in an amount sufficient to provide to the glassy polymer composition at least one microporous domain, wherein (c) said glassy polymer composition is crazed in the presence of monomers which graft polymerize with said glassy polymer composition during said crazing.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein said glassy polymer composition has a functionally effective amount of crosslinking.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein said crosslinking is provided by irradiating the glassy polymer composition.
Claim 5
Dependent Claim
23 words
The process of claim 3 wherein there is provided a sharp gradient of irradiated dosage across the thickness of the glassy polymer composition.
Claim 6
Dependent Claim
28 words
The process of claim 1 wherein said polymer composition comprises in addition to said microporous domain a dense domain which is in the form of a continuous layer.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein said glassy polymer composition comprises a glassy polymer phase and a rubbery phase.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein said glassy polymer composition comprises a slightly crystalline character.
Claim 9
Dependent Claim
13 words
The process of claim 1 wherein said glassy polymer composition is solvent crazed.
Claim 10
Dependent Claim
24 words
The process of claim 8 wherein said solvent is selected from the aliphatic hydrocarbons, the halocarbons, the aliphatic ethers, carbonyl containing solvents and alcohols.
Claim 11
Dependent Claim
13 words
The process of claim 1 wherein said membrane composition is an asymmetric membrane.
Claim 12
Dependent Claim
13 words
The process of claim 1 wherein said membrane composition is a porous membrane.
Claim 13
Dependent Claim
16 words
The process of claim 8 wherein said solvent comprises a mixture of monomer and another solvent.
Claim 14
Dependent Claim
17 words
The process of claim 12 wherein said solvent comprises a mixture of methyl methacrylate and an alcohol.
Claim 15
Dependent Claim
26 words
The process of claim 1 wherein said glassy polymer composition is selected from polystyrene, acrylonitrile butadiene styrene resins, styrene acrylonitrile copolymers and styrene acrylic acid copolymers.
Claim 16
Dependent Claim
47 words
A membrane composition comprising at least one microporous domain; said membrane composition being comprised of (a) a glassy polymer composition optionally comprising a functionally effective amount of crosslinking, and (b) a polymeric domain grafted to at least a portion of the microporous domain of said polymer composition.
Claim 17
Dependent Claim
47 words
A membrane composition comprising at least one microporous domain; said membrane composition being comprised of (a) a glassy polymer composition optionally comprising a functionally effective amount of crosslinking, and (b) a polymeric domain grafted to at least a portion of the microporous domain of said polymer composition.
Claim 18
Dependent Claim
18 words
The membrane composition of claim 15 wherein said glassy polymer composition has a functionally effective amount of crosslinking.
Claim 19
Dependent Claim
28 words
The membrane composition of claim 15 comprising in addition to said microporous domain a dense domain wherein said dense domain is in the form of a continuous layer.
Claim 20
Dependent Claim
20 words
The membrane composition of claim 15 wherein said glassy polymer composition comprises a glassy polymer phase and a rubbery phase.
Claim 21
Dependent Claim
16 words
The membrane composition of claim 15 wherein said glassy polymer composition comprises a slightly crystalline character.
Claim 22
Dependent Claim
14 words
The membrane composition of claim 15 wherein said membrane composition is an asymmetric membrane.
Claim 23
Dependent Claim
15 words
The membrane composition of claim 15 wherein said membrane composition is a hydrophobic porous membrane.
Claim 24
Dependent Claim
15 words
The membrane composition of claim 15 wherein said membrane composition is a hydrophilic porous membrane.
Claim 25
Dependent Claim
27 words
The membrane composition of claim 15 wherein said glassy polymer composition is selected from polystyrene, acrylonitrile butadiene styrene resins, styrene acrylonitrile copolymers and styrene acrylic acid copolymers.
Claim 26
Dependent Claim
28 words
The membrane composition of claim 17 wherein said dense domain is in the form of a layer having a thickness ranging from 0.1 μm to about 25 μm.
Claim 27
Dependent Claim
23 words
The membrane composition of claim 15 wherein said glassy polymer composition has a total thickness ranging from 5 μm to about 300 μm.
Claim 28
Dependent Claim
30 words
The membrane composition of claim 17 wherein the thickness of said dense domain(s) ranges from 0 to about 50 percent of the total thickness of the untreated glassy polymer composition.
Claim 29
Dependent Claim
34 words
The membrane composition of claim 15 wherein said polymeric domain grafted to at least a portion of the microporous domain provides functional groups to the surface region of the pores comprising said microporous domain.
Claim 30
Dependent Claim
39 words
The membrane composition of claim 15 wherein said polymeric domain grafted to at least a portion of the microporous domain comprises the polymerization product of alkyl esters of ethylenically unsaturated carboxylic acids, αβ-ethylenically unsaturated aromatic compounds and conjugated dienes.
Claim 31
Dependent Claim
27 words
The membrane composition of claim 15 wherein said polymeric domain grafted to at least a portion of the microporous domain comprises the polymerization product of methyl methacrylate.
References Cited (Backward Citations)
US3909463A
Cited
US4430807A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |