US3607059A
Expired / Lapsed
US
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Process for the manufacture of filamentary carbon products
Assignee: Akzo NV
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Filing: 1969-04-02
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Granted: 1971-09-21
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Expires: 1989-04-02
Abstract
Abstract Process for the manufacture of carbon and graphite filamentary products from polyacrylonitrile filamentary material wherein said filamentary material is subjected to a preliminary tension-free noncombustive partial oxidation and thereafter stretched to introduce or restore orientation in the polymer strands prior to being oxidized under tension followed by carbonization in a nonoxidizing atmosphere at a temperature of at least 700* C.
Inventors
- 👤 Louis A Joo
- 👤 Frank E Snodgrass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:00
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; D01F9/225; D01F9/32; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
129 words
In a process for the manufacture of carbon and graphite filament and yarn which comprises subjecting a precursor polyacrylonitrile filamentary material (a) to a noncumbustive oxidation process consisting of a continuous phase carried out under tension and a secondary batch phase carried out without tension, and (b) to a carbonization stage in a nonoxidizing atmosphere at a temperature of at least 700* C., the improvement which consists in first subjecting the filamentary material to a preliminary substantially tension-free noncombustive partial oxIdation in air at a temperature within the range of about 200*-250* C. for a duration within the range of about 1 to 8 hours followed by stretching of the partially oxidized filamentary material by up to about 200 percent of its original length in a boiling water environment.
Claim 2
Dependent Claim
37 words
The process of claim 1 wherein the entire sequence of operations is preceded by the stretching of the original filamentary material in an H2O environment at about 100* C. to about 150 percent of its original length.
Claim 3
Dependent Claim
31 words
The process of claim 1 wherein the preliminary tension-free noncombustive oxidation process is carried out in air at a temperature of about 220* C. during a period of about 4 hours.
Claim 4
Dependent Claim
31 words
The process of claim 2 wherein the preliminary tension-free noncombustive oxidation process is carried out in air at a temperature of about 220* C. during a period of about 4 hours.
Claim 5
Dependent Claim
37 words
The process of claim 2 wherein the entire sequence of operations is preceded by the stretching of the original filamentary material in an H2O environment at about 100* C. to about 150 percent of its original length.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |