US3668110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pitch treatment means
Assignee: LOUIS A JOE
•
Filing: 1970-10-28
•
Granted: 1972-06-06
•
Expires: 1990-10-28
Abstract
Abstract A spinnable pitch, useful in the manufacture of carbon filaments of continuous lengths, is prepared by the multiple solvent extraction of pitch, first by trituration of pitch particles with a low-boiling, aromatic solvent in which the bulk of pitch particles is essentially insoluble - then by dissolution of the pitch in a solubilizing solvent, filtration, and evaporation of the solvent.
Inventors
- 👤 Frederick L Shea
- 👤 Louis A Joe
- 👤 Thomas W Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:17
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; C; C01; C01B; C01B32/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
35 words
The process of claim 1 wherein the contacting step, b, is carried out at from about the freezing point of the solvent to about the softening point of the pitch in contact with the solvent.
Claim 2
Dependent Claim
30 words
The process of claim 1 wherein the extracting step, d, is carried out at from about the freezing point of the solvent to about the reflux temperature of the solvent.
Claim 3
Independent Claim
88 words
A method for the preparation of a spinnable pitch which comprises a. extracting the pitch with a solubilizing solvent in sufficient quantity to dissolve at least 45 percent of the pitch; b. filtering the mixture; c. evaporating the solvent from the resulting filtrate; d. grinding the resulting pitch into small particles; e. contacting the particles with an essentially aromatic or equivalent solvent to remove a total of about 10 to 30 percent based upon the original quantity of starting pitch therefrom; f. separating the solvent and the particles.
Claim 4
Dependent Claim
34 words
The process of claim 4 wherein the contacting step is carried out at from about the freezing point of the solvent to about the softening point of the pitch in contact with the solvent.
Claim 5
Dependent Claim
29 words
The process of claim 4 wherein the extracting step is carried out at from about the freezing point of the solvent to about the reflux temperature of the solvent.
References Cited (Backward Citations)
US2871181A
Cited
US2953501A
Cited
US3079326A
Cited
US3200062A
Cited
US3278415A
Cited
US3373101A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |