Patent US3970542A successfully refreshed from Google Patents.
US3970542A
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Method of preparing electrode pitches
Assignee: Cindu NV
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Filing: 1974-11-15
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Granted: 1976-07-20
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Expires: 1994-11-15
Abstract
Abstract A method for the preparation of electrode pitch which includes mixing a highly aromatic residual fraction from petroleum raw materials with a coal tar pitch in a weight ratio of from 1:9 to 9:1 and heating the mixture at a temperature of above 350°C. until a pitch is produced with a softening point above 60°C., an insolubility in anthracene oil and toluene is over 30 percent and a coking value of at least 50 corresponding to binder pitch for the production of carbon, graphite electrodes and refractory material.
Inventors
- 👤 Pieter Jan Willem Bongertman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:25
CPC Classifications
C; C10; C10C; C10C3/00; C10C3/005; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528; C04B35/532
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
A method of preparing electrode pitch consisting essentially of mixing a. a highly aromatic residual fraction produced by steam cracking a gas oil or naphtha at a temperature in excess of 750°C and fractionating to separate said residual fractions with b. a coal tar pitch in a weight ratio of 1:9 to 9:1 and heating said mixture at a temperature of above 350° to 400°C for about 51/2 hours to about 17 hours.
Claim 2
Independent Claim
73 words
A method of preparing electrode pitch consisting essentially of mixing a. a highly aromatic residual fraction produced by steam cracking a gas oil or naphtha at a temperature in excess of 750°C and fractionating to separate said residual fractions with b. a coal tar pitch in a weight ratio of 1:9 to 9:1 and heating said mixture at a temperature of above 350° to 400°C for about 51/2 hours to about 17 hours.
Claim 3
Dependent Claim
44 words
The method of claim 1 in which the heat treatment is continued until a pitch is produced with a softening point, insolubility in anthracene oil and toluene and coking value corresponding to binder pitch for the production of carbon, graphite electrodes and refractory material.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein said highly aromatic residual fraction from petroleum raw material has a softening point above 60°C.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said coal tar pitch has a content insoluble in anthracene oil of over 3 percent.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein the ratio of petroleum residue to coal tar pitch is from 4:6 to 6:4.
Claim 7
Dependent Claim
52 words
The process of claim 2, wherein said electrode pitch has a softening point of at least 105° (ring and ball); a coke number of at least 50, fraction insoluble in anthracene oil of 8-16 percent; fraction insoluble in anthracene oil of from 30-38 percent, and a density at 20°C of above 1.27.
Claim 8
Dependent Claim
9 words
The product obtained by the process of claim 1.
Claim 9
Dependent Claim
9 words
The product obtained by the process of claim 2.
Claim 10
Dependent Claim
9 words
The product obtained by the process of claim 6.
References Cited (Backward Citations)
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US3775289A
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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) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |