US3868217A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion inhibition
Assignee: Calgon Corp
•
Filing: 1974-05-09
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Granted: 1975-02-25
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Expires: 1994-05-09
Abstract
Abstract Use of mono-, di-, and triphosphoric acid esters of triethanol amine and mixtures thereof to inhibit the corrosion of metals by oxygen-bearing waters.
Inventors
- 👤 William Robert Hollingshad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:42
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
34 words
A METHOD OF INHIBITING THE CORROSION OF METALS IN A WATER SYSTEM WHICH COMPRISES MAINTAINING IN THE WATER OF SAID SYSTEM AT LEAST ABOUT 100 MG/L OF A PHOSPHORIC ACID ESTER OF TRIETHANOL AMINE.
Claim 2
Independent Claim
34 words
A METHOD OF INHIBITING THE CORROSION OF METALS IN A WATER SYSTEM WHICH COMPRISES MAINTAINING IN THE WATER OF SAID SYSTEM AT LEAST ABOUT 100 MG/L OF A PHOSPHORIC ACID ESTER OF TRIETHANOL AMINE.
Claim 3
Dependent Claim
30 words
A method as in claim 1 which further comprises maintaining in said system at least about 1 mg/l of a member selected from the group consisting of thiazoles and triazoles.
Claim 4
Dependent Claim
11 words
A method as in claim 2 wherein the thiazole is mercaptobenzothiazole.
Claim 5
Dependent Claim
11 words
A method as in claim 2 wherein the triazole is benzotriazole.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |