US4888115A
Expired / Lapsed
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Cross-flow filtration
Assignee: Specialty Materials Inc
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Filing: 1983-12-29
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Granted: 1989-12-19
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Expires: 2003-12-29
Abstract
Abstract A process for the cross-flow filtration of a liquid comprising circulating the liquid tangential to a charge modified organic polymeric microporous filter membrane. Preferably, the membrane comprises an organic polymeric microporous filter membrane which has a micro-structure throughout the membrane and an amount of a charge modifying agent bound to substantially all of the membrance micro-structure without substantial pore size reduction or pore blockage. The process may be used for the filtration of liquids, particularly parenteral or biological liquids contaminated with charged particulate and for plasmapheresis, particularly in the form of hollow fiber tubes.
Inventors
- 👤 Paul J. Marinaccio
- 👤 Ronald V. Repetti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:23
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/02; B01D61/00; B01D61/14; B01D61/147; B01D61/18; B01D67/00; B01D67/0081; B01D67/0093; B01D71/00; B01D71/06; B01D71/56; B01D2315/00; B01D2315/10; B01D2323/00; B01D2323/30
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
86 words
A process for the cross-flow filtration of a liquid containing particulate or suspended solid and dissolved solids comprising circulating the liquid tangential to and axially on one side of a charge modified organic polymeric skinless microporous hollow fiber filter membrane, substantially retaining the particulate or suspended solids on said one side, the dissolved solids passing through the membrane and the charge on the membrane repelling similarly charged particulate or suspended particles preventing clogging or blocking of pores through excessive adsorption of said particulate or suspended solids.
Claim 2
Dependent Claim
86 words
A process for the cross-flow filtration of a liquid containing particulate or suspended solid and dissolved solids comprising circulating the liquid tangential to and axially on one side of a charge modified organic polymeric skinless microporous hollow fiber filter membrane, substantially retaining the particulate or suspended solids on said one side, the dissolved solids passing through the membrane and the charge on the membrane repelling similarly charged particulate or suspended particles preventing clogging or blocking of pores through excessive adsorption of said particulate or suspended solids.
Claim 3
Dependent Claim
46 words
The process of claim 1, wherein the organic polymeric microporous filter membrane has an internal microstructure throughout said membrane and a charge modifying amount of a charge modifying agent is bonded to substantially all of the membrane microstructure without substantial pore size reduction or pore blockage.
Claim 4
Dependent Claim
12 words
The process of claim 1 or 2, wherein the liquid is blood.
Claim 5
Dependent Claim
18 words
The process of claim 1 or 2, wherein the organic polymeric microporous membrane is a hydrophilic polyvinylidene flouride.
Claim 6
Dependent Claim
19 words
The process of claim 1 or 2, wherein the organic polymeric microporous membrane is a hydrophilic ester of cellulose.
Claim 7
Dependent Claim
17 words
The process of claim 1 or 2, wherein the organic polymeric microporous membrane is a hydrophilic nylon.
Claim 8
Dependent Claim
18 words
The process of claim 1 or 2, wherein the organic polymeric microporous membrane is a hydrophilic polyhexamethylene adipamide.
Claim 9
Dependent Claim
34 words
The process of claim 1 or 2, wherein the charge modifying agent is a water soluble polymer having substituents thereon capable of bonding to the membrane and substituents thereon which are anionic or cationic.
Claim 10
Dependent Claim
32 words
The process of claim 1 or 2, wherein the charge modifying agent is anionic and a water soluble polymer having substituents thereon capable of bonding to the membrane and anionic functional groups.
Claim 11
Dependent Claim
26 words
The process of claim 9, wherein the anionic functional groups are selected from the group consisting of carboxyl, phosphonous, phosphonic and sulfonic groups or mixtures thereof.
Claim 12
Dependent Claim
12 words
The process of claim 9, wherein the anionic functional groups are carboxyl.
Claim 13
Dependent Claim
12 words
The process of claim 9, wherein the anionic functional groups are sulfonic.
Claim 14
Dependent Claim
26 words
The process of claim 9, wherein the anionic charge modifying agent is a water soluble organic polymer having a molecular weight of about 2,000 to 500,000.
Claim 15
Dependent Claim
20 words
The process of claim 9, wherein the anionic charge modifying agent is bonded to the membrane through a cross-linking agent.
Claim 16
Dependent Claim
24 words
The process of claim 9, wherein the anionic charge modifying agent is poly (styrene sulfonic) acid having a molecular weight between 2,000 and 300,000.
Claim 17
Dependent Claim
23 words
The process of claim 9, wherein the anionic charge modifying agent is poly (acrylic) acid having a molecular weight between 2,000 and 300,000.
Claim 18
Dependent Claim
22 words
The process of claim 14, wherein the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500.
Claim 19
Dependent Claim
13 words
The process of claim 17, wherein the polyepoxide is a di- or tri-epoxide.
Claim 20
Dependent Claim
19 words
The process of claim 17, wherein the polyepoxide has a molecular weight of from about 146 to about 300.
Claim 21
Dependent Claim
59 words
The process of claim 2, wherein the charge modifying agent is a primary charge modifying agent which is a water-soluble organic polymer having a molecular weight greater than about 1,000, wherein each monomer thereof has at least one epoxide group capable of bonding to the surface of the membrane and at least one tertiary amine or quaternary ammonium group.
Claim 22
Dependent Claim
65 words
The process of claim 20, wherein a portion of the epoxy groups on the charge modifying agent are bonded to a secondary charge modifying agent selected from the group consisting of: (i) aliphatic amines which are polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent.
Claim 23
Dependent Claim
18 words
The process of claim 20 or 21, wherein the primary charge modifying agent is a polyamido-polyamine epichlorohydrin resin.
Claim 24
Dependent Claim
41 words
The process of claim 21, wherein the secondary charge modifying agent is an amine of the formula: ##STR11## wherein R 1 and R 2 are alkyl of 1 and 4 carbon atoms and x is an integer from 0 to 4.
Claim 25
Dependent Claim
16 words
The process of claim 23, wherein the primary charge modifying agent is a polyamido-polyamine epichlorohydrin resin.
Claim 26
Dependent Claim
17 words
The process of claim 23 or 24, wherein the amine is tetraethylene pentamine of the formula: ##STR12##
Claim 27
Dependent Claim
82 words
The process of claim 2, wherein the charge modifying agent is a cationic charge modifying agent bonded to the membrane micro-structure through an aliphatic polyepoxide cross-linking agent having a molecular weight of less than about 500, wherein the charge modifying agent is selected from the group consisting of: (i) aliphatic amines which are polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent.
Claim 28
Dependent Claim
40 words
The process of claim 26, wherein the charge modifying agent is an amine of the formula: ##STR13## wherein R 1 and R 2 are alkyl of 1 and 4 carbon atoms and x is an integer from 0 to 4.
Claim 29
Dependent Claim
11 words
The process of claim 27, wherein R1 and R2 are ethyl.
Claim 30
Dependent Claim
15 words
The process of claim 27, wherein the amine is tetraethylene pentamine of the formula: ##STR14##
Claim 31
Dependent Claim
13 words
The process of claim 26, wherein the polyepoxide is a di- or tri-epoxide.
Claim 32
Dependent Claim
19 words
The process of claim 30, wherein the polyepoxide has a molecular weight of from about 146 to about 300.
Claim 33
Dependent Claim
33 words
The process of claim 26, wherein the polyepoxide has a formula: ##STR15## wherein the R is an alkyl of 1 to 6 carbon atoms and n is an integer from 2 to 5.
Claim 34
Dependent Claim
16 words
The process of claim 28, wherein the polyepoxide is 1,4-butanediol diglycidyl ether of the formula: ##STR16##
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) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |