US4338209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal corrosion inhibitor
Assignee: Otsuka Chemical Co Ltd
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Filing: 1980-03-31
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Granted: 1982-07-06
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Expires: 2000-03-31
Abstract
Abstract Metal corrosion inhibitor comprising (a) benzoic acid and/or a benzoate, (b) nitrous acid and/or a nitrite, (c) phosphoric acid and/or a phosphate, and (d) at least one selected from mercaptobenzothiazole, its salts, benzotriazole and tolyltriazole, which can exhibit excellent anti-corrosive property to various metals for a long term and can be diluted with an aqueous liquor and can be employed in combination with usual anti-freezing agents.
Inventors
- 👤 Isao Manabe
- 👤 Akiyoshi Inubushi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:12
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
163 words
A metal corrosion inhibitor consisting essentially of per 100 parts by weight of a compound (a) selected from the group consisting of benzoic acid, sodium benzoate, and potassium benzoate, 1.3 to 20 parts by weight of a compound (b) selected from the group consisting of nitrous acid, sodium nitrite and potassium nitrite, 3.8 to 120 parts by weight of a compound (c) selected from the group consisting of phosphoric acid, sodium dihydrogenphosphate, disodium hydrogenphosphate, trisodium phosphate, potassium dihydrogenphosphate, dipotassium hydrogenphosphate and tripotassium phosphate, and 1 to 20 parts by weight of a compound (d) selected from the group consisting of mercaptobenzothiazole, its salts, benzotriazole and tolyltriazole, the amount of sodium benzoate and potassium benzoate being calculated as benzoic acid, the amount of sodium nitrite and potassium nitriate being calculated as nitrous acid, the amount of sodium dihydrogenphosphate, disodium hydrogenphosphate, trisodium phosphate, potassium dihydrogenphosphate, dipotassium hydrogenphosphate and tripotassium phosphate being calculated as phosphoric acid, and the amount of mercaptobenzothiazole salts being calculated as mercaptobenzothiazole.
Claim 2
Dependent Claim
163 words
A metal corrosion inhibitor consisting essentially of per 100 parts by weight of a compound (a) selected from the group consisting of benzoic acid, sodium benzoate, and potassium benzoate, 1.3 to 20 parts by weight of a compound (b) selected from the group consisting of nitrous acid, sodium nitrite and potassium nitrite, 3.8 to 120 parts by weight of a compound (c) selected from the group consisting of phosphoric acid, sodium dihydrogenphosphate, disodium hydrogenphosphate, trisodium phosphate, potassium dihydrogenphosphate, dipotassium hydrogenphosphate and tripotassium phosphate, and 1 to 20 parts by weight of a compound (d) selected from the group consisting of mercaptobenzothiazole, its salts, benzotriazole and tolyltriazole, the amount of sodium benzoate and potassium benzoate being calculated as benzoic acid, the amount of sodium nitrite and potassium nitriate being calculated as nitrous acid, the amount of sodium dihydrogenphosphate, disodium hydrogenphosphate, trisodium phosphate, potassium dihydrogenphosphate, dipotassium hydrogenphosphate and tripotassium phosphate being calculated as phosphoric acid, and the amount of mercaptobenzothiazole salts being calculated as mercaptobenzothiazole.
Claim 3
Dependent Claim
29 words
The metal corrosion inhibitor of claim 1, wherein the metal corrosion inhibitor is contained in concentration of 6,000 to 70,000 p.p.m. in water or water containing an anti-freezing agent.
Claim 4
Dependent Claim
23 words
The metal corrosion inhibitor of claim 2, wherein said water or water containing an anti-freezing agent is maintained at pH 6.5 to 9.5.
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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) | 1985-07-05 | 1986-01-04 | 1986-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-05 | 1990-01-04 | 1990-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-05 | 1994-01-04 | 1994-07-06 | $7700.00 | Window Closed / Lapsed |