US4814083A
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US
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Altering pore size distributions
Assignee: Memtec Ltd
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Filing: 1986-03-06
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Granted: 1989-03-21
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Expires: 2006-03-06
Abstract
Abstract PCT No. PCT/AU86/00053 Sec. 371 Date Oct. 28, 1986 Sec. 102(e) Date Oct. 28, 1986 PCT Filed Mar. 6, 1986 PCT Pub. No. WO86/05117 PCT Pub. Date Sep. 12, 1986.Pores that are smaller than or larger than a predetermined range of pore sizes in a porous membrane barrier are blocked with a controlled porosity blocking agent. The pores are first filled with a liquid so as to remove any air therein and then subjected to a transmembrane gas blow at a pressure which will clear the larger pores of the liquid. The larger gas filled pores or the smaller liquid filled pores are then blocked by a blocking agent using a polymer-forming chemical reaction, a precipitate-forming chemical reaction or the physical deposition of solids.
Inventors
- 👤 Douglas L. Ford
- 👤 Richard D. Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:00
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
104 words
A micro-porous membrane having an original pore size distribution in which at least some of the pores are larger than or at least some of the pores are smaller than a predetermined size or both and wherein the larger pores or the smaller pores or both are blocked by a blocking agent deposited in said pores, the blocking agent being deposited by a method which comprises applying a gas transmembrane pressure to the membrane to substantially clear upper sizes of pores of wetting liquid therein, and then applying a controlled porosity blocking agent to either the liquid-filled smaller pores or the larger gas-filled pores.
Claim 2
Dependent Claim
104 words
A micro-porous membrane having an original pore size distribution in which at least some of the pores are larger than or at least some of the pores are smaller than a predetermined size or both and wherein the larger pores or the smaller pores or both are blocked by a blocking agent deposited in said pores, the blocking agent being deposited by a method which comprises applying a gas transmembrane pressure to the membrane to substantially clear upper sizes of pores of wetting liquid therein, and then applying a controlled porosity blocking agent to either the liquid-filled smaller pores or the larger gas-filled pores.
Claim 3
Dependent Claim
22 words
The membrane according to claim 1, wherein the porosity blocking agent is deposited in a controlled manner by a polymer-forming chemical reaction.
Claim 4
Dependent Claim
22 words
The membrane according to claim 1, wherein the porosity blocking agent is deposited in a controlled manner by a precipitate-forming chemical reaction.
Claim 5
Dependent Claim
23 words
The membrane according to claim 1, wherein the porosity blocking agent is deposited in a controlled manner by the physical deposition of solids.
Claim 6
Dependent Claim
37 words
The membrane according to claim 1, wherein the method of depositing the blocking agent further comprises temporarily blocking some of the larger holes, blowing and then blocking the remaining larger holes, and, unblocking the temporarily blocked holes.
Claim 7
Dependent Claim
19 words
The membrane according to claim 1, wherein the steps are repeated until a desired pore size distribution is obtained.
Claim 8
Dependent Claim
11 words
The membrane according to claim 1, wherein the liquid is hydrophilic.
Claim 9
Dependent Claim
11 words
The membrane according to claim 1, wherein the liquid is hydrophobic.
Claim 10
Dependent Claim
38 words
The membrane according to claim 1, wherein the blocking agent is selected from the group consisting of a zirconium compound, a polyamide, a urethane, a polyurethane, a urea, a polyurea, a melamine formaldehyde, and a phenol formaldehyde product.
Claim 11
Dependent Claim
80 words
The membrane according to claim 1, wherein the blocking agent is a reaction product of a compound selected from the group consisting of: (a) terephthaloyl chloride, (b) adipoyl chloride, (c) sebacoyl chloride, (d) resorcinol, and (e) hexamethylene diisocyanate with a compound, selected on chemnically reactive grounds, and being selected from the group consisting of: (f) N,N'-bis(3-aminopropyl)ethylenediamine, (g) an alkoxide diamine, (h) a polyalkoxide diamine, (i) 1,6-diaminohexane, (j) 4,4'-diaminodiphenylmethane, (k) diethylenetriamine, (l) 1,4-phenylenediamine, (m) bis(3-aminopropyl)amine, and (n) formaldehyde and an acid.
Claim 12
Dependent Claim
41 words
The membrane according to claim 1, wherein the blocking agent is a reaction product selected from the group consisting of: (a) polyvinylalcohol and hexamethylenediisocyanate, (b) melamine, formaldehyde and an acid, (c) urea-formaldehyde and an acid, and (d) terephthaloyl chloride and phenyldiamine.
Claim 13
Dependent Claim
124 words
A micro-porous membrane having an original pore size distribution in which at least some of the pores are larger than or at least some of the pores are smaller than a predetermined size or both and wherein the larger pores or the smaller pores or both are blocked by a blocking agent deposited in those pores, the blocking agent being deposited by a method comprising the steps of: (a) substantially filling the pores with a liquid, thereby substantially removing air therein, (b) subjecting the barrier to a transmembrane gas pressure at a pressure sufficient to substantially clear the larger pores of said liquid, and (c) blocking the gas-filled larger pores or the liquid-filled smaller pores in a controlled manner with a porosity blocking agent.
Claim 14
Dependent Claim
124 words
A micro-porous membrane having an original pore size distribution in which at least some of the pores are larger than or at least some of the pores are smaller than a predetermined size or both and wherein the larger pores or the smaller pores or both are blocked by a blocking agent deposited in those pores, the blocking agent being deposited by a method comprising the steps of: (a) substantially filling the pores with a liquid, thereby substantially removing air therein, (b) subjecting the barrier to a transmembrane gas pressure at a pressure sufficient to substantially clear the larger pores of said liquid, and (c) blocking the gas-filled larger pores or the liquid-filled smaller pores in a controlled manner with a porosity blocking agent.
Claim 15
Independent Claim
85 words
A method of selectively blocking pores in a porous membrane barrier, which are larger or smaller than pores of a pre-determined pore size range which are to remain unblocked, which comprises: (a) substantially clearing the pores which are larger than the pores which are to remain unblocked of a wetting liquid therein by applying a gas transmembrane pressure to said porous membrane, and then (b) blocking, in a controlled manner, either the liquid-filled smaller pores or the larger gas-filled pores with a porosity blocking agent.
Claim 16
Independent Claim
85 words
A method of selectively blocking pores in a porous membrane barrier, which are larger or smaller than pores of a pre-determined pore size range which are to remain unblocked, which comprises: (a) substantially clearing the pores which are larger than the pores which are to remain unblocked of a wetting liquid therein by applying a gas transmembrane pressure to said porous membrane, and then (b) blocking, in a controlled manner, either the liquid-filled smaller pores or the larger gas-filled pores with a porosity blocking agent.
Claim 17
Independent Claim
87 words
A method of selectively blocking pores in a porous membrane barrier, which are larger than or smaller than pores of a pre-determined pore size range which are to remain unblocked, which comprises: (a) substantially filling the pores with a liquid, thereby removing air therein, (b) subjecting the barrier to a transmembrane gas pressure at a pressure sufficient to substantially clear the larger pores of said liquid, and (c) blocking the gas-filled larger pores or the liquid-filled smaller pores, in a controlled manner, with a porosity blocking agent.
Claim 18
Independent Claim
87 words
A method of selectively blocking pores in a porous membrane barrier, which are larger than or smaller than pores of a pre-determined pore size range which are to remain unblocked, which comprises: (a) substantially filling the pores with a liquid, thereby removing air therein, (b) subjecting the barrier to a transmembrane gas pressure at a pressure sufficient to substantially clear the larger pores of said liquid, and (c) blocking the gas-filled larger pores or the liquid-filled smaller pores, in a controlled manner, with a porosity blocking agent.
Claim 19
Dependent Claim
25 words
The method according to claim 13 or claim 14, wherein the porosity blocking agent is provided in a controlled manner by a polymer-forming chemical reaction.
Claim 20
Dependent Claim
25 words
The method according to claim 13 or claim 14, wherein the porosity blocking agent is provided in a controlled manner by a precipitate-forming chemical reaction.
Claim 21
Dependent Claim
25 words
The method according to claim 13 or claim 14, wherein the porosity blocking agent is provided in a controlled manner by physical deposition of solids.
Claim 22
Dependent Claim
36 words
The method according to claim 13 or claim 14, which further comprises the steps of temporarily blocking some of the larger holes, blowing and then blocking the remaining larger holes, and unblocking the temporarily blocked holes.
Claim 23
Dependent Claim
22 words
The method according to claim 13 or claim 14, wherein the steps are repeated until a desired pore size distribution is obtained.
Claim 24
Dependent Claim
14 words
The method according to claim 13 or claim 14, wherein the liquid is hydrophilic.
Claim 25
Dependent Claim
14 words
The method according to claim 13 or claim 14, wherein the liquid is hydrophobic.
Claim 26
Dependent Claim
18 words
The method according to claim 13, wherein said gas transmembrane pressure is set by a bubble point determination.
Claim 27
Dependent Claim
38 words
The method according to claim 14, wherein the blocking agent is selected from the group consisting of a zirconium compound, a polyamide, a urethane, a polyurethane, a urea, a polyurea, a melamine formaldehyde, and a phenol formaldlehyde product.
Claim 28
Dependent Claim
80 words
The method according to claim 14, wherein the blocking agent is a reaction product of a compound selected from the group consisting of: (a) terephthaloyl chloride, (b) adipoyl chloride, (c) sebacoyl chloride, (d) resorcinol, and (e) hexamethylene diisocyanate with a compound, selected on chemically reactive grounds, and being selected from the group consisting of: (f) N,N'-bis(3-aminopropyl)ethylenediamine, (g) an alkoxide diamine, (h) a polyalkoxide diamine, (i) 1,6-diaminohexane, (j) 4,4'-diaminodiphenylmethane, (k) diethylenetriamine, (l) 1,4-phenylenediamine, (m) bis(3-aminopropyl)amine, and (n) formaldehyde and an acid.
Claim 29
Dependent Claim
41 words
The method acocrding to claim 14, wherein the blocking agent is a reaction product selected from the group consisting of: (a) polyvinylalcohol and hexamethylenediisocyanate, (b) melamine, formaldehyde and an acid, (c) urea-formaldehyde and an acid, and (d) terephthaloyl chloride and phenyldiamine.
Claim 30
Dependent Claim
18 words
The method according to claim 14, wherein said gas transmembrane pressure is set by a bubble point determination.
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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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |