US3944494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilization of trichlorodifluoro benzenes
Assignee: EIDP Inc
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Filing: 1974-05-16
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Granted: 1976-03-16
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Expires: 1994-05-16
Abstract
Abstract Trichlorodifluorobenzene is thermally stabilized particularly in the presence of engineering metals by contacting it, especially when at temperatures greater than about 200°C, with solid alkaline earth carbonates or with alkali or alkaline earth borates in a sufficient amount. The method is particularly useful in Rankine-cycle engines using trichlorodifluorobenzene as the working fluid, when the stabilizer is contained in the boiler.
Inventors
- 👤 Walter Mahler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:02
CPC Classifications
F; F01; F01K; F01K25/00; F01K25/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
61 words
In a method of heat transfer wherein trichlorodifluorobenzenes are cycled through a thermal gradient including temperatures above about 200°C, the improvement which comprises contacting said trichlorodifluorobenzenes with a thermally stabilizing amount of a solid acid acceptor selected from the group consisting of alkali metal borates, alkali metal phosphates, alkaline earth metal carbonates, alkaline earth metal borates and alkaline earth metal phosphates.
Claim 2
Dependent Claim
61 words
In a method of heat transfer wherein trichlorodifluorobenzenes are cycled through a thermal gradient including temperatures above about 200°C, the improvement which comprises contacting said trichlorodifluorobenzenes with a thermally stabilizing amount of a solid acid acceptor selected from the group consisting of alkali metal borates, alkali metal phosphates, alkaline earth metal carbonates, alkaline earth metal borates and alkaline earth metal phosphates.
Claim 3
Dependent Claim
18 words
The method of claim 1 in which the trichlorodifluorobenzenes are in contact with steel, aluminum- or nickel-base alloys.
Claim 4
Dependent Claim
21 words
The method of claim 2 wherein the trichlorodifluorobenzenes are contacted with said acid acceptor at a temperature between 300°C and 430°C.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein said acid acceptor is sodium borate.
Claim 6
Dependent Claim
12 words
The method of claim 3 wherein said acid acceptor is calcium carbonate.
Claim 7
Dependent Claim
17 words
The method of claim 3 wherein said acid acceptor is Na 5 P 3 O 10 .
Claim 8
Dependent Claim
17 words
The method of claim 3 wherein said acid acceptor is Na 6 P 6 O 13 .
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |