Patent US3591072A successfully refreshed from Google Patents.
US4079006A
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Methods of scale inhibition
Assignee: Monsanto Co
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Filing: 1976-08-02
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Granted: 1978-03-14
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Expires: 1996-08-02
Abstract
Abstract The precipitation of scale forming salts in an aqueous system is inhibited by adding either stoichiometric or substoichiometric, including threshold, amounts to said system of a phosphonomethylene amino carboxylate of the general formula ##STR1## wherein R 1 , R 2 , R 5 , Q and Z are hereinafter defined.
Inventors
- 👤 Robert S. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:20
CPC Classifications
D; D06; D06M; D06M13/00; D06M13/244; D06M13/282; D06M13/288; C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
A method of inhibiting the precipitation of scale forming salts in an aqueous system comprising adding to said system at least a precipitation inhibiting amount of a phosphonomethylene amino carboxylate having the general formula ##STR22## wherein R 1 , R 2 and R 5 are individually selected from the group consisting of hydrogen, alkali and alkaline earth metal ions, ammonium ions and alkyl ammonium ions containing up to about 18 carbon atoms; Z is selected from the group consisting of --CH 2 PO 3 R 1 R 2 , C 1-4 alkyl, C 1-4 alkenyl, C 1-4 alkanol, C 1-4 alkyl carboxylic acid, and C 2-10 alkaminomethylene phosphonic acid; and Q is selected from the group consisting of C 3-15 alkylene and alkenylene radicals and C 7-14 alkaryl radicals.
Claim 2
Independent Claim
129 words
A method of inhibiting the precipitation of scale forming salts in an aqueous system comprising adding to said system at least a precipitation inhibiting amount of a phosphonomethylene amino carboxylate having the general formula ##STR22## wherein R 1 , R 2 and R 5 are individually selected from the group consisting of hydrogen, alkali and alkaline earth metal ions, ammonium ions and alkyl ammonium ions containing up to about 18 carbon atoms; Z is selected from the group consisting of --CH 2 PO 3 R 1 R 2 , C 1-4 alkyl, C 1-4 alkenyl, C 1-4 alkanol, C 1-4 alkyl carboxylic acid, and C 2-10 alkaminomethylene phosphonic acid; and Q is selected from the group consisting of C 3-15 alkylene and alkenylene radicals and C 7-14 alkaryl radicals.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the scale forming salt is an alkaline earth metal carbonate, sulfate, oxalate, phosphate, fluoride or silicate.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein the mole ratio of precipitation inhibitor to scale forming salts is from about 1 to 1.5 to about 1 to 10,000.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the precipitation inhibitor is present in the system at a concentration of from about 0.05 to about 500 parts per million.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein each of R 1 , R 2 and R 5 is hydrogen.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein said carboxylate is an alkali metal salt.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein said carboxylate is an ammonium salt.
Claim 9
Dependent Claim
24 words
The method of claim 1 wherein each of R 1 and R 5 is an alkali metal ion and each R 2 is hydrogen.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein each of R 1 and R 5 is an ammonium ion and each R 2 is hydrogen.
Claim 11
Dependent Claim
13 words
The method of claim 1 wherein Q is a C 3-11 alkylene radical.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein said carboxylate is bis(phosphonomethylene)aminopropylene carboxylic acid.
Claim 13
Dependent Claim
12 words
The method of claim 1 wherein said carboxylate is bis(phosphonomethylene)aminopentylene carboxylic acid.
Claim 14
Dependent Claim
12 words
The method of claim 1 wherein said carboxylate is bis(phosphonomethylene)aminobenzylene carboxylic acid.
Claim 15
Dependent Claim
13 words
The method of claim 1 wherein the aqueous system contains an inorganic polyphosphate.
Claim 16
Dependent Claim
13 words
The method of claim 1 wherein the aqueous system contains a water-soluble polyacrylate.
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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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |