US4637899A
Expired / Lapsed
US
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Corrosion inhibitors for cleaning solutions
Assignee: Hydrochem LLC
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Filing: 1984-01-30
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Granted: 1987-01-20
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Expires: 2004-01-30
Abstract
Abstract A corrosion inhibitor composition comprising: (1) at least one of an aliphatic pyridinium salt or an aliphatic quinolinium salt; and (2) a sulfur-containing compound. The compositions are useful in inhibiting the corrosion of metals during the cleaning of process equipment using industrial aqueous cleaning solutions.
Inventors
- 👤 Weldon C. Kennedy, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:39
CPC Classifications
C; C11; C11D; C11D7/00; C11D7/22; C11D7/26; C11D7/265; C11D3/00; C11D3/0005; C11D3/0073; C11D7/261; C11D7/34; C23; C23G; C23G1/00; C23G1/02; C23G1/04; C23G1/06
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
92 words
An aqueous cleaning solution composition having a pH of from about 1 to about 10, consisting essentially of at least one organic acid, selected from the group consisting of alkylene polyamine polyacetic acid, hydroxyacetic acid, formic acid, and citric acid, or a salt thereof, and further having dissolved or dispersed therein, in at least an amount sufficient to inhibit the corrosion of metals in contact with said solution, a corrosion inhibitor composition comprising: (1) at least one of an aliphatic pyridinium salt or an aliphatic quinolinium salt; and (2) a sulfur-containing compound.
Claim 2
Dependent Claim
92 words
An aqueous cleaning solution composition having a pH of from about 1 to about 10, consisting essentially of at least one organic acid, selected from the group consisting of alkylene polyamine polyacetic acid, hydroxyacetic acid, formic acid, and citric acid, or a salt thereof, and further having dissolved or dispersed therein, in at least an amount sufficient to inhibit the corrosion of metals in contact with said solution, a corrosion inhibitor composition comprising: (1) at least one of an aliphatic pyridinium salt or an aliphatic quinolinium salt; and (2) a sulfur-containing compound.
Claim 3
Dependent Claim
42 words
The composition of claim 1 wherein the salt of (1) is an alkyl pyridinium salt represented by the formula: ##STR2## wherein R is alkyl; A.sup.⊖ is an anion; and each R' independently is H, --OH, --OR, --OROH, halo, alkyl, alkenyl, or alkynyl.
Claim 4
Dependent Claim
23 words
The composition of claim 2 wherein R is alkyl of from about 8 to about 18 carbon atoms and each R' is H.
Claim 5
Dependent Claim
9 words
The composition of claim 3 wherein R is dodecyl.
Claim 6
Dependent Claim
11 words
The composition of claim 1 further comprising at least one alcohol.
Claim 7
Dependent Claim
12 words
The composition of claim 1 wherein the sulfur-containing compound comprises ammonium thiocyanate.
Claim 8
Dependent Claim
19 words
The composition of claim 1 wherein the sulfur-containing compound comprises a compound having a thioamide moiety --CSNH 2 .
Claim 9
Dependent Claim
11 words
The composition of claim 7 wherein the sulfur-containing compound comprises thiourea.
Claim 10
Dependent Claim
19 words
The composition of claim 1 wherein the pH of the cleaning solution ranges from about 2 to about 10.
Claim 11
Dependent Claim
23 words
The composition of claim 1 wherein said at least one organic acid includes at least one alklene polyamine polyacetic acid or salt thereof.
Claim 12
Dependent Claim
35 words
The composition of claim 1 wherein said at least one organic acid includes at least one alklene polyamine polyacetic acid or salt thereof selected from the group consisting of HEDTA, tetraammonium EDTA, and diammonium EDTA.
Claim 13
Dependent Claim
14 words
The composition of claim 1 wherein said at least one organic acid is HEDTA.
Claim 14
Dependent Claim
30 words
The composition of claim 1 wherein said at least one organic acid comprises at least one compound selected from the group consisting of citric acid, hydroxyacetic acid, and formic acid.
Claim 15
Dependent Claim
50 words
A process for removing hardness scale and one or more iron oxide-containing deposits from a metal surface containing one or more of said deposits and scale by contacting said metal surface with an aqueous cleaning solution composition of claim 1 for a time sufficient to dissolve said deposits and scale.
Claim 16
Dependent Claim
22 words
The composition of claim 2 further comprising at least one alcohol, and at least one alkylene polyamine polyacetic acid or salt thereof.
Claim 17
Dependent Claim
18 words
The composition of claim 15 wherein the sulfur-containing compound comprises at least one of thiourea or ammonium thiocyanate.
Claim 18
Dependent Claim
111 words
An inhibited aqueous cleaning solution composition having a pH of from about 1.2 to about 10 consisting essentially of: (1) a cleaning agent comprising at least one organic acid, selected from the group consisting of alkylene polyamine polyacetic acid, hydroacetic acid, formic acid, and citric acid, or a salt thereof and, in at least an amount sufficient to inhibit the corrosion of metals which are in contact with said solution, (2) a corrosion inhibitor composition comprising a sulfur-containing compound and an alkyl pyridinium salt represented by the formula: ##STR3## wherein R is alkyl; A.sup.⊖ is an anion; and each R' independently is H, --OH, --OR, --OROH, halo, alkyl, alkenyl, or alkynyl.
Claim 19
Dependent Claim
111 words
An inhibited aqueous cleaning solution composition having a pH of from about 1.2 to about 10 consisting essentially of: (1) a cleaning agent comprising at least one organic acid, selected from the group consisting of alkylene polyamine polyacetic acid, hydroacetic acid, formic acid, and citric acid, or a salt thereof and, in at least an amount sufficient to inhibit the corrosion of metals which are in contact with said solution, (2) a corrosion inhibitor composition comprising a sulfur-containing compound and an alkyl pyridinium salt represented by the formula: ##STR3## wherein R is alkyl; A.sup.⊖ is an anion; and each R' independently is H, --OH, --OR, --OROH, halo, alkyl, alkenyl, or alkynyl.
Claim 20
Dependent Claim
19 words
A composition of claim 17 wherein the cleaning agent comprises an alkylene polyamine polyacetic acid or a salt thereof.
Claim 21
Dependent Claim
12 words
A composition of claim 17 further comprising an alcohol, and a surfactant.
Claim 22
Dependent Claim
43 words
A composition of claim 19 containing from about 145 to about 2900 mg/l of corrosion inhibitor, measured as the sum of the weight of the aliphatic pyridinium salt and the sulfur-containing compound, based on the total volume of the final inhibited cleaning solution.
Claim 23
Dependent Claim
32 words
The composition of claim 17 wherein the cleaning agent includes at least one alkylene polyamine polyacetic acid or salt thereof selected from the group consisting of HEDTA, tetraammonium EDTA, and diammonium EDTA.
Claim 24
Dependent Claim
11 words
The composition of claim 17 wherein the cleaning agent is HEDTA.
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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) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |