Patent US4702947A successfully refreshed from Google Patents.
US4702947A
Expired / Lapsed
US
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Fibrous structure and method of manufacture
Assignee: Pall Corp
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Filing: 1986-04-01
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Granted: 1987-10-27
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Expires: 2006-04-01
Abstract
Abstract Polymeric microfibrous structures comprised of normally hydrophobic microfibers coated with a cured, precipitated, cationic, thermosetting binder resin or polymer and characterized by being hydrophilic and having a positive zeta potential with enhanced capability for the removal of negatively-charged particulate material in a fluid medium are prepared by a process comprising the steps: (1) combining in a controlled manner a first solution of a water-soluble, non-colloidal, cationic, thermosetting binder resin or polymer and a second solution or dispersion of a precipitating agent to form a stable emulsion or suspension; (2) impregnating the microfibrous structure of normally hydrophobic microfibers with the stable emulsion or suspension to form a fibrous structure wetted with the stable emulsion or suspension; and (3) drying the wetted microfibrous structure and curing the binder resin or polymer.
Inventors
- 👤 David B. Pall
- 👤 Peter J. Degen
- 👤 Thomas C. Gsell
- 👤 Eleni C. Yanakis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:40
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56; D04H1/58; D04H1/587; D04H1/64; Y; Y10; Y10S; Y10S261/00; Y10S261/72; Y10S428/00; Y10S428/903; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1372; Y10T442/00; Y10T442/60; Y10T442/608; Y10T442/614
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
139 words
A process for converting a hydrophobic, polymeric, microfibrous structure to a hydrophilic form exhibiting a positive zeta potential comprising: (1) combining in a controlled manner a first solution of a water-soluble, non-colloidal, cationic thermosetting binder resin or polymer and a second solution or dispersion of a precipitating agent to form a stable emulsion or suspension of the precipitating agent and the binder resin or polymer as co-precipitates; (2) impregnating the microfibrous structure with the stable emulsion or suspension to form a microfibrous structure wetted with the stable emulsion or suspension; and (3) drying the wetted microfibrous structure of step (2) and curing the binder resin or polymer to provide a hydrophilic, polymeric, microfibrous structure with a positive zeta potential, the surfaces of the microfibers of the structure being coated with a cured, precipitated, thermoset, cationic binder resin or polymer.
Claim 2
Dependent Claim
139 words
A process for converting a hydrophobic, polymeric, microfibrous structure to a hydrophilic form exhibiting a positive zeta potential comprising: (1) combining in a controlled manner a first solution of a water-soluble, non-colloidal, cationic thermosetting binder resin or polymer and a second solution or dispersion of a precipitating agent to form a stable emulsion or suspension of the precipitating agent and the binder resin or polymer as co-precipitates; (2) impregnating the microfibrous structure with the stable emulsion or suspension to form a microfibrous structure wetted with the stable emulsion or suspension; and (3) drying the wetted microfibrous structure of step (2) and curing the binder resin or polymer to provide a hydrophilic, polymeric, microfibrous structure with a positive zeta potential, the surfaces of the microfibers of the structure being coated with a cured, precipitated, thermoset, cationic binder resin or polymer.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the microfibers of the microfibrous structure comprise a polymer selected from the group consisting of polyolefins, polyamides, and polyesters.
Claim 4
Dependent Claim
84 words
The process of claim 2 wherein the concentration of the binder resin or polymer in the first solution is in the range of from about 0.2 to about 2 weight percent, the concentration of the precipitating agent in the second solution or dispersion is in the range of from about 0.05 to about 1 percent, and the weight ratio of binder resin or polymer to precipitating agent in the stable emulsion or suspension is in the range of from about 4:1 to about 1:1.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein the stable emulsion or suspension comprises a co-precipitate of precipitating agent and the binder resin or polymer, water, and a lower alcohol.
Claim 6
Dependent Claim
77 words
The process of claim 4 wherein the stable suspension is prepared by combining the first solution and the second solution or dispersion at mild shear rates provided by a stirrer operating at from about 20 to about 60 RPM and with the binder resin or polymer solution added to the second solution or dispersion of a precipitating agent by use of a multiplicity of capillary orifices located just above the level of the second solution or dispersion.
Claim 7
Dependent Claim
33 words
The process of claim 4 wherein the first solution comprises the binder resin or polymer, water, and t-butyl alcohol and the second solution or dispersion comprises the precipitating agent, water and t-butyl alcohol.
Claim 8
Dependent Claim
25 words
The process of claim 6 wherein the binder resin or polymer comprises an epoxide-based, water-soluble resin and the precipitating agent comprises an anionic precipitating agent.
Claim 9
Dependent Claim
14 words
The process of claim 7 wherein the binder resin or polymer comprises polyamido/polyamino-epichlorohydrin resin.
Claim 10
Dependent Claim
15 words
The process of claim 8 wherein the precipitating agent comprises a water-soluble, thermosetting acrylic resin.
Claim 11
Dependent Claim
19 words
The process of claim 1 wherein excess emulsion or suspension is removed prior to drying the wetted microfibrous structure.
Claim 12
Dependent Claim
18 words
The process of claim 1 wherein the microfibrous structure comprises an annular, cylindrical microfibrous structure with structural rigidity.
Claim 13
Dependent Claim
38 words
The process of claim 11 wherein the impregnating of the microfibrous structure is carried out by spinning the annular cylindrical microfibrous structrure in a substantially horizontal position and inserting the stable emulsion or suspension into the interior thereof.
Claim 14
Dependent Claim
155 words
A process for converting an annular, cylindrical, structurally rigid, hydrophobic, polymeric, microfibrous structure comprised of polypropylene microfibers to a hydrophilic form exhibiting a positive zeta potential comprising: (1) combining in a controlled manner (a) a first solution of a polyamido/polyamino-ephichlorohydrin binder resin in a solvent of t-butyl alcohol and water, and (b) a second solution of a water-soluble, thermosetting acrylic resin precipitating agent in a solvent of t-butyl alcohol and water to form a stable emulsion or suspension of the precipitating agent and the binder resin as co-precipitates; (2) impregnating the microfibrous structure with the stable emulsion or suspension to form a microfibrous structure wetted with the stable emulsion or suspension; and (3) drying the wetted microfibrous structure of step (2) and curing the binder resin to provide a hydrophilic, polymeric, microfibrous structure with a positive zeta potential, the surfaces of the microfibers of the structure being coated with a cured, precitated, thermoset polyamido/polyaminoepichlorohydrin resin.
Claim 15
Dependent Claim
155 words
A process for converting an annular, cylindrical, structurally rigid, hydrophobic, polymeric, microfibrous structure comprised of polypropylene microfibers to a hydrophilic form exhibiting a positive zeta potential comprising: (1) combining in a controlled manner (a) a first solution of a polyamido/polyamino-ephichlorohydrin binder resin in a solvent of t-butyl alcohol and water, and (b) a second solution of a water-soluble, thermosetting acrylic resin precipitating agent in a solvent of t-butyl alcohol and water to form a stable emulsion or suspension of the precipitating agent and the binder resin as co-precipitates; (2) impregnating the microfibrous structure with the stable emulsion or suspension to form a microfibrous structure wetted with the stable emulsion or suspension; and (3) drying the wetted microfibrous structure of step (2) and curing the binder resin to provide a hydrophilic, polymeric, microfibrous structure with a positive zeta potential, the surfaces of the microfibers of the structure being coated with a cured, precitated, thermoset polyamido/polyaminoepichlorohydrin resin.
Claim 16
Dependent Claim
38 words
The process of claim 13 wherein the impregnating of the microfibrous structure is carried out by spinning the annular, cylindrical microfibrous structure in a substantially horizontal position and inserting the stable emulsion or suspension into the interior thereof.
Claim 17
Dependent Claim
49 words
A three-dimensional, polymeric, microfibrous structure with structural rigidity comprising normally hydrophobic microfibers coated with a cured, precipitated, cationic, thermoset binder resin or polymer, said structure characterized by being hydrophilic and having a positive zeta potential and enhanced capability for the removal of negatively-charged particulate material in a fluid medium.
Claim 18
Dependent Claim
49 words
A three-dimensional, polymeric, microfibrous structure with structural rigidity comprising normally hydrophobic microfibers coated with a cured, precipitated, cationic, thermoset binder resin or polymer, said structure characterized by being hydrophilic and having a positive zeta potential and enhanced capability for the removal of negatively-charged particulate material in a fluid medium.
Claim 19
Dependent Claim
25 words
The structure of claim 15 wherein the microfibers of the microfibrous structure comprise a polymer selected from the group consisting of polyolefins, polyamides, and polyesters.
Claim 20
Dependent Claim
30 words
The structure of claim 16 wherein the binder resin is present in the hydrophilic structure in an amount in the range of from about 0.5 to about 4 weight percent.
Claim 21
Dependent Claim
30 words
The structure of claim 17 wherein the binder resin is present in the hydrophilic structure in an amount in the range of from about 0.8 to about 3 weight percent.
Claim 22
Dependent Claim
14 words
The structure of claim 16 wherein the microfibers of the microfibrous structure comprise polypropylene.
Claim 23
Dependent Claim
16 words
The structure of claim 19 wherein the binder resin or polymer comprises an epoxide-based, thermoset resin.
Claim 24
Dependent Claim
15 words
The structure of claim 20 wherein the binder resin or polymer comprises a thermoset polyamido/polyamino-epichlorohydrin.
Claim 25
Dependent Claim
15 words
The structure of claim 15 wherein said microfibrous structure comprises an annular, cylindrical microfibrous structure.
Claim 26
Dependent Claim
47 words
An annular, cylindrical microfibrous structure with structural rigidity comprising normally hydrophobic polypropylene microfibers coated with a cured, precipitated, cationic, thermoset, polyamido/polyamino-epichlorohydrin, said structure characterized by being hydrophilic and having a positive zeta potential and enhanced capability for the removal of negatively-charged particulate material in a fluid medium.
Claim 27
Dependent Claim
47 words
An annular, cylindrical microfibrous structure with structural rigidity comprising normally hydrophobic polypropylene microfibers coated with a cured, precipitated, cationic, thermoset, polyamido/polyamino-epichlorohydrin, said structure characterized by being hydrophilic and having a positive zeta potential and enhanced capability for the removal of negatively-charged particulate material in a fluid medium.
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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) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |