Patent US4545925A successfully refreshed from Google Patents.
US4545925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion inhibited freeze protected heat transfer fluid
Assignee: NORTHERN PETROCHEMICAL Co
•
Filing: 1984-05-07
•
Granted: 1985-10-08
•
Expires: 2004-05-07
Abstract
Abstract An improved corrosion inhibited, freeze protected, heat transfer fluid or antifreeze composition which is comprised of at least about 0.25 weight percent phosphate as PO 4 , greater than 0.025 weight percent nitrite as NO 2 , and the balance a polyhydroxy alcohol; with the proviso that nitrate not be present in the heat transfer fluid. When the heat transfer fluid is to be used as an antifreeze composition for internal combustion engines, it can also contain a corrosion inhibitor selected from the group consisting of 2-mercaptobenzotriazole, tolyltriazole, benzotriazole, and alkali metal salts thereof and a buffering agent.
Inventors
- 👤 Sidney F. Bosen
- 👤 Bruce D. Perlson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:09
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C09; C09K; C09K5/00; C09K5/20; C23F11/18; C23F11/187; C23F11/188
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
48 words
An improved corrosion inhibited, freeze protected, heat transfer fluid which is comprised of: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, and c. The balance a polyhydroxy alcohol; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 2
Dependent Claim
48 words
An improved corrosion inhibited, freeze protected, heat transfer fluid which is comprised of: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, and c. The balance a polyhydroxy alcohol; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 3
Independent Claim
50 words
A method for providing corrosion inhibition wherein a polyhydroxy alcohol based heat transfer fluid is utilized, comprising adding to said fluid: a. At least about 0.25 weight percent phosphate, and b. Greater than 0.025 weight percent nitrite; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 4
Independent Claim
50 words
A method for providing corrosion inhibition wherein a polyhydroxy alcohol based heat transfer fluid is utilized, comprising adding to said fluid: a. At least about 0.25 weight percent phosphate, and b. Greater than 0.025 weight percent nitrite; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 5
Dependent Claim
78 words
An improved corrosion inhibited, freeze protected, heat transfer fluid for internal combustion engines and other heat transfer systems, which comprises: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, c. A corrosion inhibitor selected from the group consisting of the 2-mercaptobenzotriazole, tolyltriazole, benzotriazole, and alkali metal salts thereof, d. A buffering agent, and e. The balance of polyhydroxy alcohol; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 6
Dependent Claim
78 words
An improved corrosion inhibited, freeze protected, heat transfer fluid for internal combustion engines and other heat transfer systems, which comprises: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, c. A corrosion inhibitor selected from the group consisting of the 2-mercaptobenzotriazole, tolyltriazole, benzotriazole, and alkali metal salts thereof, d. A buffering agent, and e. The balance of polyhydroxy alcohol; with the proviso that nitrate not be present in the heat transfer fluid.
Claim 7
Independent Claim
72 words
A method for providing corrosion inhibition wherein a polyhydroxy alcohol based heat transfer fluid is utilized, comprising adding to said fluid: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, c. A corrosion inhibitor selected from the group consisting of the 2-mercaptobenzotriazole, tolyltriazole, benzotriazole, and alkali metal salts thereof, and d. A buffering agent; with the proviso that nitrate not be present in the heat fluid.
Claim 8
Independent Claim
72 words
A method for providing corrosion inhibition wherein a polyhydroxy alcohol based heat transfer fluid is utilized, comprising adding to said fluid: a. At least about 0.25 weight percent phosphate, b. Greater than 0.025 weight percent nitrite, c. A corrosion inhibitor selected from the group consisting of the 2-mercaptobenzotriazole, tolyltriazole, benzotriazole, and alkali metal salts thereof, and d. A buffering agent; with the proviso that nitrate not be present in the heat fluid.
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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |