US4291069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rendering porous structures impermeable by treatment with gellable amine polymers
Assignee: Dow Chemical Co
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Filing: 1977-07-20
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Granted: 1981-09-22
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Expires: 1997-07-20
Abstract
Abstract Aqueous solutions of amide polymers such as polyacrylamide when treated with small amounts of a water-soluble polyaldehyde at an alkaline pH react to form film gels within a short time at ambient temperature. Such gels are usefully employed to plug porous subterranean formations, for grouting of leaking soil pipes or wells, and to otherwise render porous structures impermeable to the passage of liquids such as water.
Inventors
- 👤 Richard J. Pilny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:34
CPC Classifications
C; C09; C09K; C09K17/00; C09K17/14; C09K17/18; C09K17/20; C09K17/22; C09K8/00; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/512
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
79 words
A method for rendering a porous structure impermeable which comprises treating the porous structure with a gellable aqueous composition comprising an aqueous medium having dispersed therein an amide polymer and an aliphatic polyaldehyde in proportions such that under ambient temperatures and at an alkaline pH greater than 7.5 the gellable composition upon being forced into and over the porosities of the structure reacts to form a gel capable of rendering said structure impermeable to the passage of aqueous liquids.
Claim 2
Independent Claim
79 words
A method for rendering a porous structure impermeable which comprises treating the porous structure with a gellable aqueous composition comprising an aqueous medium having dispersed therein an amide polymer and an aliphatic polyaldehyde in proportions such that under ambient temperatures and at an alkaline pH greater than 7.5 the gellable composition upon being forced into and over the porosities of the structure reacts to form a gel capable of rendering said structure impermeable to the passage of aqueous liquids.
Claim 3
Dependent Claim
42 words
A method according to claim 1 wherein the gellable composition is prepared by mixing an aqueous solution of amide polymer and an aqueous solution or dispersion of a polyaldehyde at a pH greater than 7.5 in or immediately adjacent to said porosities.
Claim 4
Dependent Claim
21 words
A method according to claim 2 wherein the mixing takes place in aqueous medium at a pH of 11.5 to 12.
Claim 5
Dependent Claim
18 words
A method according to claim 1 wherein the amide polymer is a homo polymer or copolymer of acrylamide.
Claim 6
Dependent Claim
12 words
A method according to claim 1 wherein the polyaldehyde is a dialdehyde.
Claim 7
Dependent Claim
11 words
A method according to claim 5 wherein the dialdehyde is glyoxal.
Claim 8
Dependent Claim
97 words
A method according to claim 1 wherein the gellable composition is prepared by forming a first aqueous solution of an amide polymer at a pH of about 4 to about 5, adding to said first solution an aqueous solution or dispersion of a polyaldehyde in an amount to provide the equivalent of from 0.01 to about 0.067 mole of dialdehyde per mole of amide monomer combined in the polymer and admixing the resulting modified first solution with a second aqueous solution containing sufficient inorganic alkaline agent to bring the resulting composition to a pH greater than 7.5.
Claim 9
Dependent Claim
30 words
A method according to claim 7 wherein said second solution is an aqueous solution of an alkali metal hydroxide, carbonate or phosphate having a pH of from 11 to 12.
Claim 10
Dependent Claim
20 words
A method according to claim 8 wherein the amide polymer is a polymer of acrylamide and the polyaldehyde is glyoxal.
Claim 11
Dependent Claim
40 words
A method according to claim 9 wherein the amide polymer is a polyacrylamide having a molecular weight such that an aqueous 20 percent by weight solution of said polymer has a viscosity of from about 100 to about 10,000 centipoises.
Claim 12
Dependent Claim
107 words
In a method for grouting sewers and water wells which comprises locating a leaking area in a subterranean conduit, isolating said leaking area with packing devices and pumping a gellable composition into and over said area, the improvement which comprises preparing said gellable composition by admixing an aqueous solution of at least five weight percent of a water-soluble amide polymer with sufficient of an aqueous solution of a water-soluble aliphatic dialdehyde to provide from about 0.01 to about 0.067 mole of dialdehyde per mole of amide monomer combined in said polymer and with sufficient of an inorganic alkaline reagent to produce a pH of greater than 7.5.
Claim 13
Dependent Claim
107 words
In a method for grouting sewers and water wells which comprises locating a leaking area in a subterranean conduit, isolating said leaking area with packing devices and pumping a gellable composition into and over said area, the improvement which comprises preparing said gellable composition by admixing an aqueous solution of at least five weight percent of a water-soluble amide polymer with sufficient of an aqueous solution of a water-soluble aliphatic dialdehyde to provide from about 0.01 to about 0.067 mole of dialdehyde per mole of amide monomer combined in said polymer and with sufficient of an inorganic alkaline reagent to produce a pH of greater than 7.5.
Claim 14
Dependent Claim
24 words
A method according to claim 11 wherein the gellable composition is brought to a pH of about 11.5 to 12 to initiate rapid gelation.
Claim 15
Dependent Claim
18 words
A method according to claim 12 wherein the amide polymer is a polyacrylamide and the dialdehyde is glyoxal.
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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) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |