US3930968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of phenylhydrazine
Assignee: Hoechst AG
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Filing: 1974-02-01
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Granted: 1976-01-06
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Expires: 1994-02-01
Abstract
Abstract A process for the manufacture of phenylhydrazine by cathodic reduction of diazoaminobenzene dissolved in an electrolyte on solid electrodes with separation of cathode and anode spaces by a diaphragm wherein the diazoaminobenzene solution is electrolyzed in a flow type diaphragm cell at a graphite cathode having a three dimensional surface.
Inventors
- 👤 Jurgen Cramer
- 👤 Hartmuth Wilhelm Alt, deceased
- 👤 heir by Ortwin Franz Felix Alt
- 👤 nee Alt heir by Gudrun Anneliese Beyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:38
CPC Classifications
C; C25; C25B; C25B3/00; C25B3/20; C25B3/25; C25B3/01; C25B3/09; C25B3/27; C25B3/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
In a process for producing phenylhydrazine by cathodic reduction of diazoaminobenzene in an electrolytic cell having a cathode zone with graphite cathode therein, an anode zone with an anode therein and a diaphragm separating said cathode zone from said anode zone, and in which process a catholyte comprising an alkali metal hydroxide, ammonium hydroxide, an organic base or mixtures thereof at a temperature of -20° to 90°C. is caused to flow through said cathode zone, a voltage is applied across said anode and cathode to reduce diazoaminobenzene to phenylhydrazine in said cell and phenylhydrazine is recovered from said catholyte, the improvement which comprises providing in said cell a graphite cathode having grooves or internal passages formed therein and causing said catholyte to flow through said grooves or passages to produce phenylhydrazine at an improved yield.
Claim 2
Dependent Claim
135 words
In a process for producing phenylhydrazine by cathodic reduction of diazoaminobenzene in an electrolytic cell having a cathode zone with graphite cathode therein, an anode zone with an anode therein and a diaphragm separating said cathode zone from said anode zone, and in which process a catholyte comprising an alkali metal hydroxide, ammonium hydroxide, an organic base or mixtures thereof at a temperature of -20° to 90°C. is caused to flow through said cathode zone, a voltage is applied across said anode and cathode to reduce diazoaminobenzene to phenylhydrazine in said cell and phenylhydrazine is recovered from said catholyte, the improvement which comprises providing in said cell a graphite cathode having grooves or internal passages formed therein and causing said catholyte to flow through said grooves or passages to produce phenylhydrazine at an improved yield.
Claim 3
Dependent Claim
23 words
The process as claimed in claim 1, wherein said graphite cathode material is of particles of mean diameters from 0.5 to 30 mm.
Claim 4
Dependent Claim
22 words
The process as claimed in claim 1, wherein said graphite cathode material is of mean diameters from 1.5 mm to 10 mm.
Claim 5
Dependent Claim
34 words
The process as claimed in claim 1, wherein as graphite cathode material one or more layers or nets of graphite or of mixtures of graphite fibers with fibers of inert non-conductive materials are used.
Claim 6
Dependent Claim
18 words
The process as claimed in claim 1, wherein as graphite cathode material, stacked, flow-through graphite plates are used.
Claim 7
Dependent Claim
23 words
The process as claimed in claim 1, wherein the diaphragm is supported by a net of inert non-conductive material from the cathode body.
References Cited (Backward Citations)
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Cited
US833513A
Cited
US2069206A
Cited
DE1961364A1
Cited
US3759812A
Cited
US3836440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-05 | 1979-07-07 | 1980-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-05 | 1983-07-07 | 1984-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-05 | 1987-07-07 | 1988-01-06 | $7700.00 | Window Closed / Lapsed |