US3961943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering palladium
Assignee: Dow Chemical Co
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Filing: 1975-04-18
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Granted: 1976-06-08
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Expires: 1995-04-18
Abstract
Abstract The inactive palladium-containing precipitate formed during the reaction of a carboxylic acid and an olefin to form an ester can be reactivated by the addition of a suitable reducing agent to a slurry of the precipitate in the ester.
Inventors
- 👤 Joseph G. Schell, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:19
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/006; C22B7/007; B; B01; B01J; B01J23/00; B01J23/90; B01J23/96; C22B11/00; C22B11/04; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
A method of converting an inactive palladium-containing complex, formed during the process of making an alkylene glycol monoester from a carboxylic acid and an olefin, to metallic palladium, said method comprising reducing at least a portion of said palladium-containing complex to metallic palladium by adding hydrazine or hydrogen to a slurry of said palladium-containing complex and an alkylene glycol ester.
Claim 2
Independent Claim
60 words
A method of converting an inactive palladium-containing complex, formed during the process of making an alkylene glycol monoester from a carboxylic acid and an olefin, to metallic palladium, said method comprising reducing at least a portion of said palladium-containing complex to metallic palladium by adding hydrazine or hydrogen to a slurry of said palladium-containing complex and an alkylene glycol ester.
Claim 3
Dependent Claim
39 words
The method of claim 1 in which the reducing agent is hydrazine in a molar ratio of from 1 to about 20 mols per mole of palladium, and in which the temperature ranges from about 0°C to about 300°C.
Claim 4
Dependent Claim
24 words
The method of claim 2 in which the temperature is about 70°C and the reaction time is from about 15 to about 120 minutes.
Claim 5
Dependent Claim
21 words
The method of claim 2 in which the mole ratio of hydrazine to palladium ranges from about 11 to about 18.
Claim 6
Dependent Claim
50 words
The method of claim 2 in which the mole ratio of hydrazine to palladium is about 18, the temperature is about 70°C, the reaction time is about 30 minutes and the liquid in the slurry, is propylene glycol monoacetate and recovering about 98 percent of the palladium in the complex.
Claim 7
Dependent Claim
22 words
The method of claim 1 in which the reducing agent is hydrogen and the temperature is from about 0°C to about 300°C.
Claim 8
Dependent Claim
16 words
The method of claim 6 in which the hydrogen pressure is at least about 100 psig.
Claim 9
Dependent Claim
16 words
The method of claim 7 in which the temperature ranges from about 90° to about 150°C.
Claim 10
Dependent Claim
20 words
The method of claim 8 in which the temperature is about 113°C and the reaction time is about 2 hours.
Claim 11
Dependent Claim
35 words
The method of claim 6 in which the reducing reaction is carried in propylene glycol monoacetate, the temperature is about 113°C, the hydrogen pressure is about 200 psig and reaction time is about 2 hours.
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) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |