EP0245863A2
Expired / Lapsed
EP
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Composite ultrafiltration membranes
Assignee: EMD Millipore Corp
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Filing: 1987-05-14
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Granted: —
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Expires: 2007-05-14
Abstract
Abstract Composite ultrafiltration membranes are disclosed which are produced by forming an ultrafiltration membrane structure on a preformed microporous membrane.
Inventors
- 👤 Anthony E. Allegrezza, Jr.
- 👤 Edmund T. Burke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 18:22
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
14 words
A composite ultrafiltration membrane consisting essentially of an ultrafiltration membrane and a microporous membrane.
Claim 2
Dependent Claim
14 words
A composite ultrafiltration membrane consisting essentially of an ultrafiltration membrane and a microporous membrane.
Claim 3
Dependent Claim
16 words
A composite ultrafiltration membrane of Claim 1 wherein said microporous membrane is formed from polyvinylidene difluoride.
Claim 4
Dependent Claim
16 words
A composite ultrafiltration membrane of Claim 2 wherein said ultrafiltration membrane is formed from polyvinylidene difluoride.
Claim 5
Dependent Claim
15 words
A composite ultrafiltration membrane of Claim 2 wherein said ultrafiltration membrane is formed from polysulfone.
Claim 6
Dependent Claim
30 words
A composite ultrafiltration membrane having a matrix with a microporous structure, a relatively thin skin and an area of elongated voids between the microporous structure to the relatively thin skin.
Claim 7
Dependent Claim
30 words
A composite ultrafiltration membrane having a matrix with a microporous structure, a relatively thin skin and an area of elongated voids between the microporous structure to the relatively thin skin.
Claim 8
Dependent Claim
35 words
A composite ultrafiltration membrane comprising a preformed microporous membrane upon which is formed an ultrafiltration membrane, said composite ultrafiltration membrane having a relatively thin dense skin, a microporous substrate and an intermediate area of voids.
Claim 9
Dependent Claim
35 words
A composite ultrafiltration membrane comprising a preformed microporous membrane upon which is formed an ultrafiltration membrane, said composite ultrafiltration membrane having a relatively thin dense skin, a microporous substrate and an intermediate area of voids.
Claim 10
Dependent Claim
33 words
A composite membrane of Claim 6 additionally having a transition zone of finer pore structure than the microporous membrane, said transition zone joining the area of voids to the area of microporous structure.
Claim 11
Dependent Claim
24 words
A composite ultrafiltration membrane comprising an ultrafiltration membrane integrally joined to a microporous membrane and having a higher bubble point than said microporous membrane.
Claim 12
Dependent Claim
24 words
A composite ultrafiltration membrane comprising an ultrafiltration membrane integrally joined to a microporous membrane and having a higher bubble point than said microporous membrane.
Claim 13
Independent Claim
41 words
A method of producing a composite ultrafiltration membrane, comprising: a. treating the surfaces of a preformed microporous membrane to thereby wet said surfaces; and thereafter, b. forming an ultrafiltration membrane upon said microporous membrane to form an integral composite ultrafiltration membrane.
Claim 14
Independent Claim
41 words
A method of producing a composite ultrafiltration membrane, comprising: a. treating the surfaces of a preformed microporous membrane to thereby wet said surfaces; and thereafter, b. forming an ultrafiltration membrane upon said microporous membrane to form an integral composite ultrafiltration membrane.
Claim 15
Dependent Claim
14 words
A method of Claim 9 wherein said microporous membrane is formed from polyvinylidene difluoride.
Claim 16
Dependent Claim
17 words
A method of Claim 10 wherein the surfaces of said preformed microporous membranes are treated with glycerine.
Claim 17
Dependent Claim
58 words
A method of Claim 11 wherein said ultrafiltration membrane is formed on the microporous membrane by: a. casting a solution of polymer and solvent for said polymer onto the treated microporous membrane; and, b. immersing the coated microporous membrane into a liquid which is miscible with the solvent for the polymer but is a nonsolvent for the polymer.
Claim 18
Dependent Claim
11 words
A method of Claim 12 wherein the polymer comprises polyvinylidene difluoride.
Claim 19
Dependent Claim
11 words
A composite ultrafiltration membrane formed by the process of Claim 9.
Claim 20
Dependent Claim
11 words
A composite ultrafiltration membrane formed by the process of Claim 13.
Claim 21
Dependent Claim
23 words
A composite ultrafiltration membrane consisting essentially of an ultrafiltration membrane and a microporous membrane, both said membranes being formed from the same polymer.
Claim 22
Dependent Claim
23 words
A composite ultrafiltration membrane consisting essentially of an ultrafiltration membrane and a microporous membrane, both said membranes being formed from the same polymer.
Claim 23
Dependent Claim
13 words
A composite ultrafiltration membrane of Claim 16 wherein said polymer is polyvinylidene difluoride.
References Cited (Backward Citations)
No citation records indexed.
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