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US3671447A Expired / Lapsed US ⏱️ 0.0 years remaining

Methods of scale inhibition using substoichiometric amounts of amino alchols

Assignee: Monsanto Co
•
Filing: 1970-07-27
•
Granted: 1972-06-20
•
Expires: 1990-07-27
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Abstract

Abstract The precipitation of scale-forming materials in an aqueous system is inhibited by adding substoichiometric amounts of an amino alcohol such as triethanolamine to said system.

Inventors

  • 👤 Xavier Kowalski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 15:19
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 31 words
The method of claim 1 wherein the scale-forming material is selected from the group consisting of alkaline earth metal carbonates, sulfates, oxalates, phosphates, fluorides, silicates, transition metal hydroxides, or mixtures thereof.
Claim 2
Dependent Claim 23 words
The method of claim 1 wherein the mole ratio of precipitation inhibitor to scale-forming cation material is from about 1:2.5 to about 1:10,000.
Claim 3
Dependent Claim 11 words
The method of claim 1 wherein the amino alcohol is triethanolamine.
Claim 4
Dependent Claim 14 words
The method of claim 4 wherein the scale-forming material is an iron hydroxy compound.
Claim 5
Dependent Claim 28 words
The method of claim 4 wherein the precipitation inhibitor is present in the system at concentrations from about 0.1 part per million to about 500 parts per million.
Claim 6
Independent Claim 29 words
A method of inhibiting the precipitation of iron hydroxy compounds in an alkaline aqueous system containing calcium and magnesium ions, comprising adding threshold amounts of triethanolamine to said system.
Claim 7
Dependent Claim 20 words
A method of claim 7 wherein the alkaline aqueous system has a pH of from about 6.5 to about 12.
Claim 8
Dependent Claim 22 words
The method of claim 8 wherein the mole ratio of triethanolamine to iron hydroxy compound is from about 1:2.5 to about 1:10,000.
Claim 9
Dependent Claim 27 words
The method of claim 8 wherein the triethanolamine is present in the system at concentrations from about 0.1 part per million to about 500 parts per million.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-20 1975-12-20 1976-06-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-20 1979-12-20 1980-06-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-20 1983-12-20 1984-06-20 $7700.00 Window Closed / Lapsed

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