US3853828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for crosslinking fluorocarbon polymers
Assignee: United States Department of the Army
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Filing: 1973-11-21
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Granted: 1974-12-10
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Expires: 1993-11-21
Abstract
Abstract A method for crosslinking specified fluorocarbon polymers, such as Viton elastomers (copolymers of vinylidene fluoride and hexafluoropropene), by exposing the polymer to dilute fluorine gas, e.g., 5% fluorine in helium, preferably under ordinary temperature and pressure, using relatively small amounts of fluorine so that crosslinking of the polymer results with substantially no introduction of fluorine into the polymer molecule. The crosslinked polymers or vulcanizates thus obtained possess better thermal stability than vulcanizates produced from such fluorocarbon polymers by prior art crosslinking methods.
Inventors
- 👤 L Wall
- 👤 D Brown
- 👤 R Florin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:12
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/18; C08F8/20; C08F8/22; C08K; C08K3/00; C08K3/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
75 words
A PROCESS FOR CROSSLINKING FLUOROCARBON POLYMERS WITHOUT REQUIRING THE USE OF SOLID OR LIQUID ADDITIVES SELECTED FROM THE GROUP CONSISTING OF 3,3,3-TRIFLUOROPROPENE HOMOPOLYMERS A,B,B-TRIFLUOROSTYRENE HOMOPOLYMERS 1,2,3,4,5-TRIFLUOROSTYRENE HOMOPOLYMERS VINYLIDENE FLUORIDE-HEXAFLUOROPROPENE COPOLYMERS VINYLIDENE FLUORIDE-TETRAFLUOROETHYLENE COPOLYMERS 3,3,3-TRIFLUOROPENTENE-TETRAFLUOROETHYLENE COPOLYMERS 5,5,5,4,4,3,3-HEPTAFLUOROPENTENE-1-TETRAFLUOROETHYLENE COPOLYMERS WHICH COMPRISES CONTACTING THE POLYMER WITH GASEOUS FLUORINE DILUTED WITH AT LEAST ABOUT 5 TIMES ITS VOLUME OF AN INERT GAS SO THAT CROSSLINKING OF THE POLYMER IS ACCOMPLISHED WITH SUBSTANTIALLY NO INTRODUCTION OF FLUORINE INTO THE POLYMER.
Claim 2
Dependent Claim
75 words
A PROCESS FOR CROSSLINKING FLUOROCARBON POLYMERS WITHOUT REQUIRING THE USE OF SOLID OR LIQUID ADDITIVES SELECTED FROM THE GROUP CONSISTING OF 3,3,3-TRIFLUOROPROPENE HOMOPOLYMERS A,B,B-TRIFLUOROSTYRENE HOMOPOLYMERS 1,2,3,4,5-TRIFLUOROSTYRENE HOMOPOLYMERS VINYLIDENE FLUORIDE-HEXAFLUOROPROPENE COPOLYMERS VINYLIDENE FLUORIDE-TETRAFLUOROETHYLENE COPOLYMERS 3,3,3-TRIFLUOROPENTENE-TETRAFLUOROETHYLENE COPOLYMERS 5,5,5,4,4,3,3-HEPTAFLUOROPENTENE-1-TETRAFLUOROETHYLENE COPOLYMERS WHICH COMPRISES CONTACTING THE POLYMER WITH GASEOUS FLUORINE DILUTED WITH AT LEAST ABOUT 5 TIMES ITS VOLUME OF AN INERT GAS SO THAT CROSSLINKING OF THE POLYMER IS ACCOMPLISHED WITH SUBSTANTIALLY NO INTRODUCTION OF FLUORINE INTO THE POLYMER.
Claim 3
Dependent Claim
21 words
The process according to claim 1, wherein the fluorine is diluted with at least about 10 times its volume of helium.
Claim 4
Dependent Claim
24 words
The process according to claim 1, wherein the polymer is contacted with the diluted fluorine at a temperature between about 0*C. and about 50*C.
Claim 5
Dependent Claim
19 words
The process according to claim 1, wherein the polymer is contacted with the diluted fluorine under substantially atmospheric pressure.
Claim 6
Dependent Claim
38 words
The process according to claim 1, wherein the polymer is contacted with fluorine diluted with at least 10 times its volume of helium at a temperature between about 0*C. and about 50*C. under a pressure below 5 atmospheres.
Claim 7
Dependent Claim
13 words
The process of claim 1, wherein the polymer is a vinylidene fluoridehexafluoropropene copolymer.
Claim 8
Dependent Claim
19 words
The process of claim 6, wherein the copolymer contains about 4 vinylidene fluoride monomer units per hexafluoropropene monomer unit.
Claim 9
Dependent Claim
13 words
The process of claim 1, wherein the polymer is a vinylidene fluoridechlorotrifluoroethylene copolymer.
Claim 10
Dependent Claim
15 words
The process of claim 1, wherein the polymer is in the form of a film.
Claim 11
Dependent Claim
10 words
A crosslinked polymer obtained by the process of claim 1.
Claim 12
Dependent Claim
10 words
A crosslinked polymer obtained by the process of claim 6.
Claim 13
Dependent Claim
10 words
A crosslinked polymer obtained by the process of claim 7.
Claim 14
Dependent Claim
10 words
A crosslinked polymer obtained by the process of claim 8.
References Cited (Backward Citations)
US2497046A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |