Patent US4301136A successfully refreshed from Google Patents.
US4301136A
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US
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Process for continuous graphitization of graphitizable precursor fibers
Assignee: Toray Industries Inc
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Filing: 1980-05-16
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Granted: 1981-11-17
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Expires: 2000-05-16
Abstract
Abstract An improved process for manufacturing high-grade and high-quality graphite fibers by the steps of (a) heating carbon fibers from acrylic fibers in an initial heating zone while exposed to an atmosphere of inert gas having a maximum temperature from about 1700 DEG C. to 1900 DEG C., and (b) then heating the resulting fibers in a subsequent heating zone while exposed to an atmosphere of inert gas having a maximum temperature from 2300 DEG C. to 2700 DEG C.
Inventors
- 👤 Ryuichi Yamamoto
- 👤 Shizuo Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:03
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/32; D01F9/20; D01F9/21; D01F9/22
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
148 words
A process for continuously graphitizing a carbon fiber obtained from an acrylic fiber consisting essentially of at least about 95 mol % of acrylonitrile and up to about 5 mol % of one or more ethylene-type vinyl compounds which are copolymerizable with acrylonitrile which comprises passing the fiber successively through a first and a separate second heating zone, each of said zones containing an inert atmosphere and having a temperature of at least 800° C., maintaining the maximum temperature of the first heating zone at about 1700° to about 1900° C., a heating rate which is a mean heating rate of from about 1300° C. to the maximum temperature minus 100° C. at about 300° C./min to 2000° C./min, and a heating time of about 10 seconds to 10 minutes, and maintaining the maximum temperature of the second heating zone at about 2300° C. to about 2700° C.
Claim 2
Dependent Claim
148 words
A process for continuously graphitizing a carbon fiber obtained from an acrylic fiber consisting essentially of at least about 95 mol % of acrylonitrile and up to about 5 mol % of one or more ethylene-type vinyl compounds which are copolymerizable with acrylonitrile which comprises passing the fiber successively through a first and a separate second heating zone, each of said zones containing an inert atmosphere and having a temperature of at least 800° C., maintaining the maximum temperature of the first heating zone at about 1700° to about 1900° C., a heating rate which is a mean heating rate of from about 1300° C. to the maximum temperature minus 100° C. at about 300° C./min to 2000° C./min, and a heating time of about 10 seconds to 10 minutes, and maintaining the maximum temperature of the second heating zone at about 2300° C. to about 2700° C.
Claim 3
Dependent Claim
59 words
The process according to claim 1, wherein the heating rate of said second zone is a mean heating rate of from 1900° C. to the maximum temperature minus 100° C. is at about 2000° C./min to 10000° C./min and the total heating time of the treated fiber in the heating zones is about 10 seconds to about 5 minutes.
Claim 4
Dependent Claim
22 words
The process according to claim 2, wherein the heating rate of said first heating zone is about 500° C./min to 1500° C./min.
Claim 5
Dependent Claim
27 words
The process according to claim 1, wherein said carbon fiber is obtained at the maximum temperature of about 800° C. to 1500° C. in an inert atmosphere.
Claim 6
Dependent Claim
23 words
The process according to claim 4, wherein said carbon fiber is obtained at the maximum temperature of about 1000° C. to 1500° C.
Claim 7
Dependent Claim
23 words
The process according to claim 3, wherein the heating time in said first heating zone is about 30 seconds to about 3 minutes.
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) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |