US3881977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of graphite fibers
Assignee: United States Department of the Air Force
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Filing: 1972-11-15
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Granted: 1975-05-06
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Expires: 1992-11-15
Abstract
Abstract A method of fabricating a composite reinforced with graphite yarn that comprises heating the yarn in an oxidizing atmosphere and then coating the yarn with a thermoplastic polymer. Thereafter, the treated yarn is coated with a thermosetting resin prior to fabrication of composites having greatly enhanced interlaminar shear strength.
Inventors
- 👤 Richard J Dauksys
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:16
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; C08J5/06; Y; Y10; Y10S; Y10S273/00; Y10S273/23; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/31504; Y10T428/31511
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
61 words
A method for treating graphite yarn which comprises heating the yarn in air at a temperature in the range of 1000* to 4500*F for a period ranging from about 0.10 to 12 seconds; passing the heated yarn through a sOlution of a thermoplastic polymer, thereby coating the yarn with the polymer; and evaporating solvent from the coating on the graphite yarn.
Claim 2
Independent Claim
61 words
A method for treating graphite yarn which comprises heating the yarn in air at a temperature in the range of 1000* to 4500*F for a period ranging from about 0.10 to 12 seconds; passing the heated yarn through a sOlution of a thermoplastic polymer, thereby coating the yarn with the polymer; and evaporating solvent from the coating on the graphite yarn.
Claim 3
Dependent Claim
17 words
A method according to claim 1 in which the yarn is passed through an oxidizing gas flame.
Claim 4
Dependent Claim
15 words
The method according to claim 2 in which the gas flame is a propane-generated flame.
Claim 5
Dependent Claim
24 words
The method according to claim 1 in which the solution contains in the range of about 0.5 to 25 weight percent of thermoplastic polymer.
Claim 6
Dependent Claim
33 words
The method according to claim 4 in which the amount of thermoplastic polymer coated on the graphite yarn is in the range of about 5 to 30 percent by weight of the yarn.
Claim 7
Dependent Claim
33 words
The method according to claim 5 in which the thermoplastic polymer is selected from the group consisting of a polyhydroxy ether, a polyphenylene oxide, a polysulfone, a polyarylsulfone, a polycarbonate and a polyamide.
Claim 8
Independent Claim
106 words
A METHOD FOR FABRICATING A COMPOSITE REINFORCED WITH GRAPHITE YARN WHICH COMPRISES HEATING THE YARN IN 1000* AT A TEMPERATURE IN THE RANGE OF 100* TO 4500*F FOR A PERIOD RANGING FROM ABOUT 0.10 TO 12 SECONDS; PASSING THE HEATED YARN THROUGH A SOLUTION OF A THERMOPLASTIC POLYMER, THEREBY COATING THE YARN WITH THE POLYMER; EVAPORATING SOLVENT FROM THE COATING ON THE GRAPHITE YARN; PASSING THE COATED YARN THROUGH A SOLUTION OF A THERMOSETTING RESIN; THEREBY COATING THE THERMOPLASTIC POLYMER COATED YARN WITH THERMOSETTING RESIN; EVAPORATING SOLVENT FROM THE COATED YARN; AND MOLDING PORTIONS OF THE COATED YARN UNDER HEAT AND PRESSURE TO FORM A COMPOSITE.
Claim 9
Independent Claim
106 words
A METHOD FOR FABRICATING A COMPOSITE REINFORCED WITH GRAPHITE YARN WHICH COMPRISES HEATING THE YARN IN 1000* AT A TEMPERATURE IN THE RANGE OF 100* TO 4500*F FOR A PERIOD RANGING FROM ABOUT 0.10 TO 12 SECONDS; PASSING THE HEATED YARN THROUGH A SOLUTION OF A THERMOPLASTIC POLYMER, THEREBY COATING THE YARN WITH THE POLYMER; EVAPORATING SOLVENT FROM THE COATING ON THE GRAPHITE YARN; PASSING THE COATED YARN THROUGH A SOLUTION OF A THERMOSETTING RESIN; THEREBY COATING THE THERMOPLASTIC POLYMER COATED YARN WITH THERMOSETTING RESIN; EVAPORATING SOLVENT FROM THE COATED YARN; AND MOLDING PORTIONS OF THE COATED YARN UNDER HEAT AND PRESSURE TO FORM A COMPOSITE.
Claim 10
Dependent Claim
103 words
A method according to claim 7 in which the first mentioned solution contains in the range of about 0.5 to 25 weight percent of thermoplastic polymer; the amount of thermoplastic polymer coated on the graphite yarn is in the range of about 5 to 30 percent by weight of the yarn; the second mentioned solution contains in the range of about 30 to 80 weight percent of thermosetting resin; and the amount of thermosetting resin coated on the thermoplastic polymer coated yarn is in the range of about 25 to 60 weight percent, based upon the weight of the thermoplastic polymer coated yarn.
Claim 11
Dependent Claim
60 words
The method according to claim 8 in which the thermoplastic polymer is selected from the group consisting of a polyhydroxy ether, a polyphenylene oxide, a polysulfone, a polyarylsulfone, a polycarbonate and a polyamide and the thermosetting resin is selected from the group consisting of an epoxy resin, a phenolic resin, a polyimide resin, a polybenzimidazole resin, and a pyrrone resin.
Claim 12
Dependent Claim
20 words
THE METHOD ACCORDING TO CLAIM 9 IN WHICH THE THERMOPLASTIC POLYMER IS A POLYHYDROXY ETHER HAVING THE FOLLOWING STRUCTURAL FORMULA:
Claim 13
Dependent Claim
58 words
The method according to claim 9 in which the thermosplastic polymer is poly(2,6-diphenyl-1,4-phenylene oxide); the thermosetting resin is an epoxy resin; stacked plies of the coated yarn are molded at a temperature in the range of about 175* to 450*F under a pressure of about 100 to 1000 psi for a period of about 1 to 8 hours.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |