US4624990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Melt-shapeable fluoropolymer compositions
Assignee: Tyco International Ltd Bermuda
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Filing: 1985-04-04
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Granted: 1986-11-25
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Expires: 2005-04-04
Abstract
Abstract Melt-shapeable polymeric compositions comprising a first fluoropolymer of relatively low crystallinity, e.g. a copolymer of tetrafluoroethylene and a perfluorinated comonomer, and a second fluoropolymer of relatively high crystallinity, especially a fluoropolymer obtained by irradiating PTFE or another fluoropolymer which cannot be melt-shaped in the absence of other polymers. The weight ratio of the first to the second polymer is preferably 0.3:1 to 2.5:1. The compositions have a wide variety of uses, for example as insulating materials or, if they contain carbon black or another conductive filler, as PTC conductive polymers.
Inventors
- 👤 Hans E. Lunk
- 👤 Donald A. Reed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:57
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/02; H01C7/028; C; C08; C08L; C08L27/00; C08L27/02; C08L27/12; C08L27/18; H01B; H01B1/00; H01B1/20; H01B1/24; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/443; H01B3/445; C08L2205/00; C08L2205/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
71 words
A composition which can be melt-shaped and which comprises a mixture of (1) a first fluoropolymer which has a crystallinity less than 45% and which can be melt-shaped in the absence of other polymers, and (2) a second crystalline fluoropolymer which has a crystallinity of at least 50% and which has been obtained by irradiating a fluoropolymer which, prior to irradiation, could not be melt-extruded in the absence of other polymer.
Claim 2
Dependent Claim
71 words
A composition which can be melt-shaped and which comprises a mixture of (1) a first fluoropolymer which has a crystallinity less than 45% and which can be melt-shaped in the absence of other polymers, and (2) a second crystalline fluoropolymer which has a crystallinity of at least 50% and which has been obtained by irradiating a fluoropolymer which, prior to irradiation, could not be melt-extruded in the absence of other polymer.
Claim 3
Dependent Claim
41 words
A composition according to claim 1 wherein the first fluoropolymer has a melt viscosity at 380° C. of 5×10 3 to 1×10 6 poise, and the second fluoropolymer has a melt viscosity at 380° C. of less than 10 6 poise.
Claim 4
Dependent Claim
24 words
A composition according to claim 1 wherein the ratio by weight of the first fluoropolymer to the second fluoropolymer is from 0.3:1 to 0.7:1.
Claim 5
Dependent Claim
28 words
A composition according to claim 1 wherein the first fluoropolymer has a crystallinity of less than 20% and the second fluoropolymer has a crystallinity of more than 65%.
Claim 6
Dependent Claim
24 words
A composition according to claim 1 wherein the second fluoropolymer is polytetrafluoroethylene which has been irradiated to a dosage of 5 to 30 Mrad.
Claim 7
Dependent Claim
22 words
A composition according to claim 1 wherein the first fluoropolymer is a copolymer of tetrafluoroethylene and at least one other perfluorinated comonomer.
Claim 8
Dependent Claim
27 words
A composition according to claim 1 wherein the first fluoropolymer is a copolymer of tetrafluoroethylene and hexafluoropropylene, or a copolymer of tetrafluoroethylene and a perfluorinated vinyl ether.
Claim 9
Dependent Claim
74 words
A shaped article which is composed of a melt-shaped composition comprising a mixture of (1) a first fluoropolymer which has a crystallinity of less than 45% and which can be melt-shaped in the absence of other polymers, and (2) a second crystalline fluoropolymer which has a crystallinity of at least 50% and which has been obtained by irradiating a fluoropolymer which, prior to irradiation, could not be melt-extruded in the absence of other polymer.
Claim 10
Dependent Claim
74 words
A shaped article which is composed of a melt-shaped composition comprising a mixture of (1) a first fluoropolymer which has a crystallinity of less than 45% and which can be melt-shaped in the absence of other polymers, and (2) a second crystalline fluoropolymer which has a crystallinity of at least 50% and which has been obtained by irradiating a fluoropolymer which, prior to irradiation, could not be melt-extruded in the absence of other polymer.
Claim 11
Dependent Claim
23 words
An article according to claim 8 wherein the ratio by weight of the first fluoropolymer to the second fluoropolymer is 0.3:1 to 2.5:1.
Claim 12
Dependent Claim
42 words
An article according to claim 8 wherein the first fluoropolymer has a crystallinity of 5% to 30% and a melt viscosity at 380° C. of 5×10 3 to 10 6 poise, and the second fluoropolymer has a crystallinity of more than 60%.
Claim 13
Dependent Claim
24 words
An article according to claim 9 wherein the second fluoropolymer is polytetrafluoroethylene which has been irradiated to a dosage of 2.5 to 40 Mrad.
Claim 14
Dependent Claim
10 words
A composition according to claim 1 which is electrically insulating.
Claim 15
Dependent Claim
13 words
A shaped article according to claim 8 wherein the composition is electrically insulating.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |