Patent US4656022A successfully refreshed from Google Patents.
US4656022A
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Process for producing pitch carbon fibers
Assignee: Eneos Corp
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Filing: 1986-01-17
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Granted: 1987-04-07
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Expires: 2006-01-17
Abstract
Abstract In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the pitch fibers are subjected to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25 DEG C. in the range between 0.5 and 500 cSt and removing said dimethyl polysiloxane by washing prior to the carbonization.
Inventors
- 👤 Seiichi Uemura
- 👤 Takao Hirose
- 👤 Yoshio Sohda
- 👤 Takayoshi Sakamoto
- 👤 Kenji Katoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:24
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the improvement which comprises subjecting the pitch fibers to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25° C. in the range between 0.5 and 500 cSt, then removing said dimethyl polysiloxane by washing, and subjecting the infusiblized fibers to application of a dimethyl polysiloxane having a viscosity at 25° C. in the range between 12,000 and 1,000,000 cSt prior to the carbonization.
Claim 2
Dependent Claim
94 words
In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the improvement which comprises subjecting the pitch fibers to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25° C. in the range between 0.5 and 500 cSt, then removing said dimethyl polysiloxane by washing, and subjecting the infusiblized fibers to application of a dimethyl polysiloxane having a viscosity at 25° C. in the range between 12,000 and 1,000,000 cSt prior to the carbonization.
Claim 3
Dependent Claim
22 words
Process according to claim 1 wherein the washing of the dimethyl polysiloxane is carried out by the use of an organic solvent.
Claim 4
Dependent Claim
63 words
Process according to claim 1 wherein the amount of the applied dimethyl polysiloxane at the first stage is in the range between 0.01 and 50% by weight on the basis of the pitch fibers and the amount of the applied dimethyl polysiloxane at the second stage is in the range between 0.5 and 30% by weight on the basis of the infusiblized fibers.
Claim 5
Dependent Claim
22 words
Process according to claim 1 wherein the second-stage dimethyl polysiloxane is applied in the form of a solution in a non-aqueous solvent.
References Cited (Backward Citations)
US3552922A
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JPS54134126A
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US4259307A
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US4460557A
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JPS59199872A
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JPS59223315A
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JPS6088124A
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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) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |