Patent US3754957A successfully refreshed from Google Patents.
US3754957A
Expired / Lapsed
US
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Enhancement of the surface characteristics of carbon fibers
Assignee: Celanese Corp
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Filing: 1970-08-20
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Granted: 1973-08-28
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Expires: 1990-08-20
Abstract
Abstract An improved process is provided for modifying the suface characteristics of a carbonaceous fibrous material (either amorphous carbon or graphitic carbon) and to thereby facilitate enhanced adhesion between the fibrous material and a matrix material. The fibrous material is continuously passed at a relatively rapid rate through a heating zone containing a minor quantity of gaseous molecular oxygen under conditions found suitable for bringing about the desired surface modification. Composite articles of enhanced interlaminar shear strength may be formed by incorporating the fibers modified in accordance with the present process in a resinous matrix material.
Inventors
- 👤 M Druin
- 👤 G Ferment
- 👤 V Rao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:26
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; C08J5/06; D; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/122; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/2973; Y10T428/2978
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
22 words
An improved process according to claim 1 wherein said carbonaceous fibrous material contains at least about 95 per cent carbon by weight.
Claim 2
Dependent Claim
19 words
An improved process according to claim 1 wherein said carbonaceous fibrous material includes a substantial quantity of graphitic carbon.
Claim 3
Dependent Claim
59 words
An improved process according to claim 1 wherein said carbonaceous fibrous material is derived from an acrylic fibrous material selected from the group consisting of an acrylonitrile homopolymer and acrylonitrile copolymers which contain at least about 85 mole per cent of acrylonitrile units and up to about 15 mole per cent Of one or more monovinyl units copolymerized therewith.
Claim 4
Dependent Claim
22 words
An improved process according to claim 1 wherein said continuous langth of carbonaceous fibrous material is one or more continuous multifilament yarn.
Claim 5
Dependent Claim
22 words
An improved process according to claim 1 wherein said inert gas is selected from the group consisting of nitrogen, argon, and helium.
Claim 6
Dependent Claim
54 words
An improved process according to claim 1 wherein said heating zone is provided at a temperature of about 1,000* to 1300* C. and a gaseous atmosphere consisting of about 0.4 to 2.0 per cent by volume molecular oxygen and about 98 to 99.6 per cent by volume of an inert gas is introduced therein.
Claim 7
Dependent Claim
35 words
An improved process according to claim 1 wherein said mole ratio of molecular oxygen provided in said heating zone to that of carbon present in said carbonaceous fibrous material ranges from about 0.02:1 to 0.25:1.
Claim 8
Dependent Claim
199 words
An improved process for the modification of the surface characteristics of a carbonaceous fibrous material containing at least about 95 per cent carbon by weight and exhibiting a predominantly graphitic X-ray diffraction pattern so as to improve its ability to bond to a resinous matrix material comprising: a. continuously introducing a continuous length of said carbonaceous fibrous material into a heating zone provided at a temperature of about 1,000* to 1800* C. b. continuously introducing a gaseous atmosphere consisting of about 0.2 to 4 per cent by volume molecular oxygen and about 96 to 99.8 per cent by volume of an inert gas into said heating zone with the mole ratio of said molecular oxygen provided in said heating zone to that of carbon present in said carbonaceous fibrous material ranging from about 0.02:1 to 0.25:1, c. continuously withdrawing a portion of the gaseous atmosphere from said heating zone, d. continuously passing in the direction of its length a continuous length of said carbonaceous fibrous material through said heating zone at said temperature for a residence time of about 5 to 60 seconds, and e. continuously withdrawing the resulting continuous length of carbonaceous fibrous material from said heating zone.
Claim 9
Dependent Claim
22 words
An improved process according to claim 9 wherein said carbonaceous fibrous material contains at least about 99 per cent carbon by weight.
Claim 10
Dependent Claim
59 words
An improved process according to claim 9 wherein said carbonaceous fibrous material is derived from an acrylic fibrous material selected from the group consisting of an acrylonitrile homopolymer and acrylonitrile copolymers which contain at least about 85 mole per cent of acrylonitrile units and up to about 15 mole per cent of one or more monovinyl units copolymerized therewith.
Claim 11
Dependent Claim
22 words
An improved process according to claim 9 wherein said continuous length of carbonaceous fibrous material is one or more continuous multifilament yarn.
Claim 12
Dependent Claim
55 words
An improved process according to claim 9 wherein said heating zone is provided at a temperature of about 1,000* to 1300* C. and a gaseous atmosphere consisting of about 0.4 to 2.0 per cent by volume molecular oxygen and about 98 to 99.6 per cent by volume of an inert gas is continuously introduced therein.
Claim 13
Dependent Claim
22 words
An improved process according to claim 9 wherein said inert gas is selected from the group consisting of nitrogen, argon, and helium.
Claim 14
Dependent Claim
22 words
An improved process according to claim 13 wherein said inert gas is selected from the group consisting of nitrogen, argon, and helium.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |