Patent US4240925A successfully refreshed from Google Patents.
US4240925A
Expired / Lapsed
US
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Inhibition of pitting corrosion
Assignee: Baker Hughes Holdings LLC
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Filing: 1978-08-02
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Granted: 1980-12-23
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Expires: 1998-08-02
Abstract
Abstract This invention relates to a process of inhibiting pitting corrosion which is characterized by the use of synergistic mixtures of organic anodic and cathodic corrosion inhibitors. These synergistic mixtures effectively inhibit pitting corrosion in highly oxygenated systems without the conventional use of heavy metals such as zinc (Zn) or chromium (Cr). This invention also relates to the use of alkoxysilyl alkylene polyamines as pitting corrosion inhibitors.
Inventors
- 👤 William S. Tait
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:36
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
56 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphoric acid ester, amide, amide-ester or combination thereof, and said anodic corrosion inhibitor being an organic compound containing at least one member of the class consisting of the carboxylic, sulfonic, sulfate and acidic SH groups.
Claim 2
Dependent Claim
56 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphoric acid ester, amide, amide-ester or combination thereof, and said anodic corrosion inhibitor being an organic compound containing at least one member of the class consisting of the carboxylic, sulfonic, sulfate and acidic SH groups.
Claim 3
Dependent Claim
53 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphoric acid ester, amide, amide-ester or combination thereof and said anodic corrosion inhibitor containing at least one of the following: 2-hydroxy-1,2,3-propanetricarboxylic acid 3,4,5-trihydroxy-benzoic acid 2-phosphono-butane-1,2,4-tricarboxylic acid 2-mercaptobenzothiazole 5,5'-indigosulfonic acid maleic acid 4-hydroxy-3-methoxy-benzaldehyde.
Claim 4
Dependent Claim
53 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphoric acid ester, amide, amide-ester or combination thereof and said anodic corrosion inhibitor containing at least one of the following: 2-hydroxy-1,2,3-propanetricarboxylic acid 3,4,5-trihydroxy-benzoic acid 2-phosphono-butane-1,2,4-tricarboxylic acid 2-mercaptobenzothiazole 5,5'-indigosulfonic acid maleic acid 4-hydroxy-3-methoxy-benzaldehyde.
Claim 5
Dependent Claim
13 words
The composition of claim 2 where the cathodic corrosion inhibitor is phosphorylated pentaerythritol.
Claim 6
Dependent Claim
10 words
The composition of claim 2 containing 4-hydroxy-3-methoxy-benzaldehyde and phosphorylated pentaerythritol.
Claim 7
Dependent Claim
11 words
The composition of claim 2 containing 3,4,5-trihydroxy-benzoic acid and phosphorylated pentaerythritol.
Claim 8
Dependent Claim
56 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphonic acid ester, amide, amide-ester or combination thereof, and said anodic corrosion inhibitor being an organic compound containing at least one member of the class consisting of the carboxylic, sulfonic, sulfate and acidic OH groups.
Claim 9
Dependent Claim
56 words
A pitting corrosion inhibiting composition comprising a cathodic corrosion inhibitor and an anodic corrosion inhibitor, said cathodic corrosion inhibitor being a phosphonic acid ester, amide, amide-ester or combination thereof, and said anodic corrosion inhibitor being an organic compound containing at least one member of the class consisting of the carboxylic, sulfonic, sulfate and acidic OH groups.
Claim 10
Dependent Claim
28 words
The composition of claim 6 where the anodic corrosion inhibitor contains at least one of the following: 2-hydroxy-1,2,3-propanetricarboxylic acid 3,4,5-trihydroxy-benzoic acid 2-phosphono-butane-1,2,4-tricarboxylic acid 5,5'-indigosulfonic acid maleic acid 4-hydroxy-3-methoxy-benzaldehyde.
Claim 11
Dependent Claim
51 words
A pitting corrosion inhibiting composition comprising an anodic corrosion inhibitor and a cathodic corrosion inhibitor, said anodic corrosion inhibitor containing at least one of the following: 2-hydroxy-1,2,3-propanetricarboxylic acid 3,4,5-trihydroxybenzoic acid 2-phosphono-butane-1,2,4-tricarboxylic acid 2-mercaptobenzothiazole 5,5'-indigosulfonic acid maleic acid 4-hydroxy-3-methoxybenzaldehyde; and said cathodic corrosion inhibitor is phosphonylated (trimethoxysilylpropyl) ethylene diamine or phosphonylated diethylenetriamine.
Claim 12
Dependent Claim
51 words
A pitting corrosion inhibiting composition comprising an anodic corrosion inhibitor and a cathodic corrosion inhibitor, said anodic corrosion inhibitor containing at least one of the following: 2-hydroxy-1,2,3-propanetricarboxylic acid 3,4,5-trihydroxybenzoic acid 2-phosphono-butane-1,2,4-tricarboxylic acid 2-mercaptobenzothiazole 5,5'-indigosulfonic acid maleic acid 4-hydroxy-3-methoxybenzaldehyde; and said cathodic corrosion inhibitor is phosphonylated (trimethoxysilylpropyl) ethylene diamine or phosphonylated diethylenetriamine.
Claim 13
Dependent Claim
31 words
A process of inhibiting pitting corrosion of metallic equipment in an oxygenated aqueous system conducive to such corrosion, which comprises treating such system with a phosphonylated alkylene polyamine containing alkoxysilyl groups.
Claim 14
Dependent Claim
31 words
A process of inhibiting pitting corrosion of metallic equipment in an oxygenated aqueous system conducive to such corrosion, which comprises treating such system with a phosphonylated alkylene polyamine containing alkoxysilyl groups.
Claim 15
Dependent Claim
15 words
The process of claim 9 where the treating material is a phosphonylated (trialkoxysilylalkyl) alkylene polyamine.
Claim 16
Dependent Claim
12 words
The process of claim 9 where the polyamine is (trimethoxysilylpropyl) ethylene diamine.
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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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |