Patent US4199625A successfully refreshed from Google Patents.
US4199625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rendering porous structures impermeable by treatment with pH insensitive gelable compositions of amide polymers
Assignee: Dow Chemical Co
•
Filing: 1978-06-02
•
Granted: 1980-04-22
•
Expires: 1998-06-02
Abstract
Abstract Aqueous solutions of amide polymers, such as polyacrylamide when treated with small amounts of a water-soluble polyaldehyde and a hypohalite salt at an alkaline pH, react to form firm gels within a short time at ambient temperature. Such gels, which are stable under alkaline as well as acidic conditions, 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
- 👤 Thomas W. Regulski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:50
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/50; C09K8/504; C09K8/506; C09K8/508; C09K8/512; C09K17/00; C09K17/40; C09K17/48
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
91 words
A method for rendering a porous structure impermeable which comprises treating the porous structure with a gelable aqueous reaction mixture comprising an aqueous medium having dispersed therein a water-soluble polymer derived from an ethylenically unsaturated amide, an aliphatic polyaldehyde and a metal salt of a hypohalite in proportions such that under conditions of temperature and alkaline pH greater than 7.5 the reaction mixture 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
91 words
A method for rendering a porous structure impermeable which comprises treating the porous structure with a gelable aqueous reaction mixture comprising an aqueous medium having dispersed therein a water-soluble polymer derived from an ethylenically unsaturated amide, an aliphatic polyaldehyde and a metal salt of a hypohalite in proportions such that under conditions of temperature and alkaline pH greater than 7.5 the reaction mixture 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
40 words
The method of claim 1 wherein the gelable reaction mixture is prepared by mixing in an aqueous medium the polyaldehyde with amide polymer, an alkali metal hypohalite at a pH greater than 7.5 in or immediately adjacent to said porosities.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the reaction mixture has an initial pH from about 10.5 to 12.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein the amide polymer is a homopolymer or copolymer of acrylamide.
Claim 6
Dependent Claim
12 words
The method according to claim 1 wherein the polyaldehyde is a dialdehyde.
Claim 7
Dependent Claim
10 words
The method of claim 5 wherein the dialdehyde is glyoxal.
Claim 8
Dependent Claim
13 words
The method of claim 2 wherein the alkali metal hypohalite is sodium hypochlorite.
Claim 9
Dependent Claim
62 words
A gelable aqueous reaction mixture comprising an aqueous medium having dispersed therein a water-soluble polymer derived from an ethylenically unsaturated amide, an aliphatic polyaldehyde and a metal salt of a hypohalite in proportions such that when the reaction mixture is subjected to an effective reaction temperature and an alkaline pH greater than 7.5 the reaction mixture reacts to form a water-insoluble gel.
Claim 10
Dependent Claim
62 words
A gelable aqueous reaction mixture comprising an aqueous medium having dispersed therein a water-soluble polymer derived from an ethylenically unsaturated amide, an aliphatic polyaldehyde and a metal salt of a hypohalite in proportions such that when the reaction mixture is subjected to an effective reaction temperature and an alkaline pH greater than 7.5 the reaction mixture reacts to form a water-insoluble gel.
Claim 11
Dependent Claim
27 words
The mixture of claim 8 wherein the amide polymer is a homopolymer or copolymer of acrylamide, the polyaldehyde is glyoxal and the hypohalite salt is sodium hypochlorite.
Claim 12
Dependent Claim
23 words
The gel made by subjecting the reaction mixture of claim 8 to an effective reaction temperature and an alkaline pH greater than 7.5.
Claim 13
Dependent Claim
24 words
The method of claim 1 wherein the polymer contains from about 50 to 100 mole percent of one or more ethylenically unsaturated carboxamide monomers.
Claim 14
Dependent Claim
29 words
The method of claim 1 wherein the polymer contains from about 90 to 100 mole percent of acrylamide, the polyaldehyde is glyoxal and the hypohalite salt is sodium hypohalite.
Claim 15
Dependent Claim
26 words
The method of claim 1 wherein a solution of polymer and polyaldehyde and an alkaline hypohalite solution are introduced into the porous structures via separate stream.
References Cited (Backward Citations)
US2856380A
Cited
US2940729A
Cited
US3244640A
Cited
US3437625A
Cited
US3520925A
Cited
US3810468A
Cited
US3556221A
Cited
US3759857A
Cited
US3759197A
Cited
US3953342A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |