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US4774132A
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Polyvinylidene difluoride structure
Assignee: Pall Corp
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Filing: 1986-05-01
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Granted: 1988-09-27
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Expires: 2006-05-01
Abstract
Abstract A polyvinylidene difluoride structure with a critical surface energy of at least about 80 dynes/cm and a method of making such a structure comprising the steps of contacting a polyvinylidene difluoride structure with an alkalized solution, such as potassium hydroxide, to form activated sites on the surface of the structure; rinsing the activated structure to remove residual alkali; contacting the rinsed, activated structure with a solution of a polymerization initiator, such as potassium peroxydisulfate, and a polymerizable vinylic monomer, such as acrylic acid; and polymerizing and grafting the monomer to the activated structure to form a polyvinylidene difluoride structure with a critical surface energy of at least about 80 dynes/cm.
Inventors
- 👤 Irving B. Joffee
- 👤 Peter J. Degen
- 👤 Frederick A. Baltusis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:50
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/34; C; C08; C08J; C08J7/00; C08J7/12; C08J7/16; B01D2323/00; B01D2323/38; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/16; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
142 words
A polyvinylidene difluoride structure with a high critical surface energy comprising a polyvinylidene difluoride porous membrane or fibrous web substrate having grafted thereto a polymer derived at least in part from polymerizable vinylic monomer having the formula: ##STR3## wherein R is H, an aminoalkyl or quaternized aminoalkyl group having 1 to 3 carbon atoms, or a hydroxy alkyl group having 1 to 3 carbon atoms; R', R" and R"' independently are H, and alkyl group having 1 to 3 carbon atoms, a carboxyl group (--COOH), a carboxyalkyl group having 1 to 3 carbon atoms, or a hydroxyalkyloxycarbonyl group having 1 to 3 carbon atoms, said polymer including functional groups sufficiently polar or ionic that said structure has a critical surface energy of at least about 80 dynes/cm and said polyvinylidene difluoride substrate prior to grafting having activated sites formed on the surface.
Claim 2
Dependent Claim
142 words
A polyvinylidene difluoride structure with a high critical surface energy comprising a polyvinylidene difluoride porous membrane or fibrous web substrate having grafted thereto a polymer derived at least in part from polymerizable vinylic monomer having the formula: ##STR3## wherein R is H, an aminoalkyl or quaternized aminoalkyl group having 1 to 3 carbon atoms, or a hydroxy alkyl group having 1 to 3 carbon atoms; R', R" and R"' independently are H, and alkyl group having 1 to 3 carbon atoms, a carboxyl group (--COOH), a carboxyalkyl group having 1 to 3 carbon atoms, or a hydroxyalkyloxycarbonyl group having 1 to 3 carbon atoms, said polymer including functional groups sufficiently polar or ionic that said structure has a critical surface energy of at least about 80 dynes/cm and said polyvinylidene difluoride substrate prior to grafting having activated sites formed on the surface.
Claim 3
Dependent Claim
24 words
The structure of claim 1 wherein said structure is a microporous membrane having a pore rating of from about 0.01 to about 2 micrometers.
Claim 4
Dependent Claim
24 words
The structure of claim 2 wherein said structure is a microporous membrane having a pore rating of from about 0.04 to about 1.5 micrometers.
Claim 5
Dependent Claim
31 words
The structure of claim 1 wherein said monomer is selected from the class consisting of acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-trimethylammonioethyl acrylate chloride, and mixtures thereof.
Claim 6
Dependent Claim
72 words
A microporous polyvinylidene difluoride membrane with a high critical surface energy comprising a polyvinylidene difluoride substrate having grafted thereto a polymer derived at least in part from acrylic acid, said membrane having a pore rating in the range of from about 0.04 to about 2 micrometers and a critical surface energy of at least about 80 dynes/cm and said polyvinylidene difluoride substrate prior to grafting having activated sites formed on the surface.
Claim 7
Dependent Claim
72 words
A microporous polyvinylidene difluoride membrane with a high critical surface energy comprising a polyvinylidene difluoride substrate having grafted thereto a polymer derived at least in part from acrylic acid, said membrane having a pore rating in the range of from about 0.04 to about 2 micrometers and a critical surface energy of at least about 80 dynes/cm and said polyvinylidene difluoride substrate prior to grafting having activated sites formed on the surface.
Claim 8
Dependent Claim
16 words
The membrane of claim 5 wherein said critical surface energy is at least about 85 dynes/cm.
Claim 9
Dependent Claim
17 words
The membrane of claim 6 wherein said membrane is in the form of a disc or cartridge.
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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) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |