US4728497A
Expired / Lapsed
US
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Use of aminophenol compounds as oxygen scavengers in an aqueous medium
Assignee: Veolia WTS USA Inc
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Filing: 1980-12-15
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Granted: 1988-03-01
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Expires: 2000-12-15
Abstract
Abstract A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to the medium an effective amount of a hydrazine-free aqueous solution of an aminophenol compound or acid salt thereof having the formula ##STR1## where a=1, 2, or 3; b is 0 or 1 and x=amino or alkylamino (C1-C4).
Inventors
- 👤 John A. Muccitelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:27
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/20; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/141; C23F11/142
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
63 words
A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to said medium an effective amount of a hydrazine-free aqueous solution of an aminophenol compound or acid addition salt thereof having the formula: ##STR6## wherein a=1, 2, or 3; b is 0 or 1; and X=amino or alkylamino wherein the alkyl group is C 1 -C 4 .
Claim 2
Independent Claim
63 words
A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to said medium an effective amount of a hydrazine-free aqueous solution of an aminophenol compound or acid addition salt thereof having the formula: ##STR6## wherein a=1, 2, or 3; b is 0 or 1; and X=amino or alkylamino wherein the alkyl group is C 1 -C 4 .
Claim 3
Dependent Claim
17 words
A method according to claim 1 wherein said aqueous medium is that of a water heating system.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein said aminophenol compound comprises p-aminophenol.
Claim 5
Dependent Claim
13 words
A method according to claim 1 wherein said aminophenol compound comprises 2,4-diaminophenol dihydrochloride.
Claim 6
Dependent Claim
12 words
A method according to claim 1 wherein said aminophenol compound comprises 5-methyl-o-aminophenol.
Claim 7
Dependent Claim
12 words
A method according to claim 1 wherein said aminophenol compound comprises o-aminophenol.
Claim 8
Dependent Claim
12 words
A method according to claim 1 wherein said aminophenol compound comprises 3-methyl-p-aminophenol.
Claim 9
Dependent Claim
37 words
A method according to claim 1 wherein said aminophenol compound or acid addition salt thereof is added to said aqueous medium in an amount of about 0.05 to 200 parts per million parts of said aqueous medium.
Claim 10
Dependent Claim
37 words
A method according to claim 8 wherein said aminophenol compound or acid addition salt thereof is added to said aqueous medium in an amount of about 0.2 to 35 parts per million parts of said aqueous medium.
Claim 11
Dependent Claim
18 words
A method according to claim 1 wherein said aqueous medium is condensed steam in a boiler condensate system.
Claim 12
Dependent Claim
14 words
A method according to claim 10 wherein said aqueous medium has an alkaline pH.
Claim 13
Independent Claim
66 words
A method for reducing the amount of oxygen in oxygen containing feedwater to a boiler comprising added to said feed-water an effective amount for the purpose of a hydrazine-free aqueous solution of an aminophenol compound or acid addition salt thereof having the formula: ##STR7## wherein a=1, 2, or 3; b=0 or 1; and X=amino or alkylamino, wherein the alkyl group is C 1 -C 4 .
Claim 14
Independent Claim
66 words
A method for reducing the amount of oxygen in oxygen containing feedwater to a boiler comprising added to said feed-water an effective amount for the purpose of a hydrazine-free aqueous solution of an aminophenol compound or acid addition salt thereof having the formula: ##STR7## wherein a=1, 2, or 3; b=0 or 1; and X=amino or alkylamino, wherein the alkyl group is C 1 -C 4 .
Claim 15
Dependent Claim
35 words
A method according to claim 12 wherein said aminophenol compound or acid addition salt thereof is added to said feedwater in an amount of about 0.05 to 200 parts per million parts of said feedwater.
Claim 16
Dependent Claim
35 words
A method according to claim 12 wherein said aminophenol compound or acid addition salt thereof is added to said feedwater in an amount of about 0.2 to 35 parts per million parts of said feedwater.
Claim 17
Dependent Claim
12 words
A method according to claim 12 wherein said aminophenol compound comprises p-aminophenol.
Claim 18
Dependent Claim
13 words
A method according to claim 12 wherein said aminophenol compound comprises 2,4-diaminophenol dihydrochloride.
Claim 19
Dependent Claim
12 words
A method according to claim 12 wherein said aminophenol compound comprises 5-methyl-o-aminophenol.
Claim 20
Dependent Claim
12 words
A method according to claim 12 wherein said aminophenol compound comprises o-aminophenol.
Claim 21
Dependent Claim
12 words
A method according to claim 12 wherein said aminophenol compound comprises 3-methyl-p-aminophenol.
Claim 22
Independent Claim
44 words
A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to said medium an effective amount of a hydrazine-free aqueous solution of a compound selected from the group consisting of p-aminophenol; 2,4-diaminophenol dihydrochloride; 5-Methyl-o-aminophenol; o-aminophenol; 3-Methyl-p-aminophenol; and mixtures thereof.
Claim 23
Independent Claim
44 words
A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to said medium an effective amount of a hydrazine-free aqueous solution of a compound selected from the group consisting of p-aminophenol; 2,4-diaminophenol dihydrochloride; 5-Methyl-o-aminophenol; o-aminophenol; 3-Methyl-p-aminophenol; and mixtures thereof.
Claim 24
Independent Claim
84 words
A method for control of corrosion of metal surfaces in a boiler system caused by dissolved oxygen in the water, which comprises adding to the said system an effective amount of an aminophenol compound or acid addition salt thereof having the formula: ##STR8## in which R is OH, R 1 is amino or lower alkyl amino wherein the alkyl group is C 1 -C 4 , and R 2 is methyl; said aminophenol compound or acid addition salt thereof being the sole scavenger present.
Claim 25
Independent Claim
84 words
A method for control of corrosion of metal surfaces in a boiler system caused by dissolved oxygen in the water, which comprises adding to the said system an effective amount of an aminophenol compound or acid addition salt thereof having the formula: ##STR8## in which R is OH, R 1 is amino or lower alkyl amino wherein the alkyl group is C 1 -C 4 , and R 2 is methyl; said aminophenol compound or acid addition salt thereof being the sole scavenger present.
Claim 26
Dependent Claim
21 words
The method according to claim 21 in which the pH of the water in the boiler system is maintained above 7.5.
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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) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |