Patent EP0094543A2 successfully refreshed from Google Patents.
US5085784A
Expired / Lapsed
US
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Use of cationic charge modified filter media
Assignee: 3M Innovative Properties Co
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Filing: 1990-11-27
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Granted: 1992-02-04
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Expires: 2010-11-27
Abstract
Abstract A process for removing particulate contaminants from a fluid is disclosed, the fluid being passed through a filter media comprising cellulose fiber and silica based particulate or fiber filter elements and a charge modifying amount of a cationic charge modifying system bonded to the surfaces thereof. One component of the charge modifying system is a primary charge modifying agent characterized as a water soluble organic polymer capable of being adsorbed into the filter elements and having a molecular weight greater than about 1000. Each monomer of the polymer can have at least one epoxide group capable of bonding to the surface of the filter elements and at least one quaternary ammonium group. A portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent.
Inventors
- 👤 Eugene A. Ostreicher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:01
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/18; D; D21; D21H; D21H27/00; D21H27/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
144 words
A process for removing particulate contaminants from a fluid containing said contaminants comprising passing the fluid through a filter media comprising filter elements of cellulose fiber and silica based particulate or fiber and a charge modifying amount of a cationic charge modifying system bonded to surfaces to said elements, the system comprising: a primary charge modifying agent which is a water soluble organic polymer capable of being adsorbed onto elements and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to the surfaces of the elements and quaternary ammonium groups; and a secondary charge modifying agent bonded to a portion of the epoxy groups on the organic polymer, wherein said secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
Claim 2
Dependent Claim
144 words
A process for removing particulate contaminants from a fluid containing said contaminants comprising passing the fluid through a filter media comprising filter elements of cellulose fiber and silica based particulate or fiber and a charge modifying amount of a cationic charge modifying system bonded to surfaces to said elements, the system comprising: a primary charge modifying agent which is a water soluble organic polymer capable of being adsorbed onto elements and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to the surfaces of the elements and quaternary ammonium groups; and a secondary charge modifying agent bonded to a portion of the epoxy groups on the organic polymer, wherein said secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
Claim 3
Dependent Claim
10 words
The process of claim 1, wherein the fluid is aqueous.
Claim 4
Dependent Claim
10 words
The process of claim 2, wherein the contaminant is pyrogen.
Claim 5
Dependent Claim
16 words
The process of claim 2, wherein the pH of the fluid is up to about 12.
Claim 6
Dependent Claim
10 words
The process of claim 1, wherein the fluid comprises proteins.
Claim 7
Dependent Claim
10 words
The process of claim 5, wherein the contaminant is pyrogen.
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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) | 1995-02-03 | 1995-08-05 | 1996-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-03 | 1999-08-05 | 2000-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-03 | 2003-08-05 | 2004-02-04 | $7700.00 | Window Closed / Lapsed |