US4148982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal modification method for fluoroelastomers
Assignee: AGC Inc
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Filing: 1977-07-06
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Granted: 1979-04-10
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Expires: 1997-07-06
Abstract
Abstract High molecular fluoroelastomers are thermally modified by heating the fluoroelastomer at its thermally degradable temperature in the presence of oxygen under maintaining elasticity. The modified fluoroelastomers have the improved adhesiveness and processability and are easily vulcanized.
Inventors
- 👤 Mituharu Morozumi
- 👤 Gen Kojima
- 👤 Takeshi Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:24
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/50; C08F214/00; C08F214/18; C08F214/22; C08F214/26; C08F214/265; C08F2810/00; C08F2810/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
A method for thermally modifying a fluoroelastomer, which comprises: heating a fluoroelastomer selected from the group consisting of propylene-tetrafluoroethylene based copolymers, vinylidene-fluoride-hexafluoropropylene based copolymers, vinylidenefluoride-pentafluoropropylene based copolymers, and vinylidenefluoride-trifluorochloroethylene based copolymers having a number average molecular weight of more than 30,000 at a temperature at which it thermally degrades ranging from 250° to 450° C. for more than 15 minutes in the presence of oxygen while maintaining the elasticity of said fluoroelastomer.
Claim 2
Independent Claim
72 words
A method for thermally modifying a fluoroelastomer, which comprises: heating a fluoroelastomer selected from the group consisting of propylene-tetrafluoroethylene based copolymers, vinylidene-fluoride-hexafluoropropylene based copolymers, vinylidenefluoride-pentafluoropropylene based copolymers, and vinylidenefluoride-trifluorochloroethylene based copolymers having a number average molecular weight of more than 30,000 at a temperature at which it thermally degrades ranging from 250° to 450° C. for more than 15 minutes in the presence of oxygen while maintaining the elasticity of said fluoroelastomer.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said fluoroelastomer is an addition polymer.
Claim 4
Dependent Claim
32 words
The method of claim 1, wherein said propylene-tetrafluoroethylene based copolymer is heated at a temperature at which it thermally degrades ranging from 250° to 450° C. for 15 minutes to 24 hours.
Claim 5
Dependent Claim
37 words
The method of claim 1, wherein said vinylidenefluoride-hexafluoropropylene base copolymer or said vinylidenefluoride-pentafluoropropylene based copolymer is heated at a temperature at which it thermally degrades ranging from 270° to 450° C. for 15 minutes to 24 hours.
Claim 6
Dependent Claim
32 words
The method of claim 1, wherein said vinylidenefluoride-trifluorochloroethylene based copolymer is heated at a temperature at which it thermally degrades ranging from 250° to 450° C. for 15 minutes to 24 hours.
Claim 7
Dependent Claim
27 words
The method of claim 1, wherein the thermal modification is conduted at a temperature of 250° to 450° C. for 5 minutes to 24 hours in air.
Claim 8
Dependent Claim
69 words
A thermally modified fluoroelastomer prepared by heating a fluoroelastomer selected from the group consisting of proplylene-tetrafluoroethylene based copolymers, vinylidene-fluoride-hexafluoroproplylene based copolymers, vinylidene-fluoride-pentafluoropropylene based copolymers, and vinylidene-fluoride-trifluorochloroethylene based copolymers having a number average molecular weight of more than 30,000 at a temperature at which it thermally degrades ranging from 250° to 450° C. for more than 15 minutes in the presence of oxygen while maintaining the elasticity of said fluoroelastomer.
Claim 9
Dependent Claim
69 words
A thermally modified fluoroelastomer prepared by heating a fluoroelastomer selected from the group consisting of proplylene-tetrafluoroethylene based copolymers, vinylidene-fluoride-hexafluoroproplylene based copolymers, vinylidene-fluoride-pentafluoropropylene based copolymers, and vinylidene-fluoride-trifluorochloroethylene based copolymers having a number average molecular weight of more than 30,000 at a temperature at which it thermally degrades ranging from 250° to 450° C. for more than 15 minutes in the presence of oxygen while maintaining the elasticity of said fluoroelastomer.
Claim 10
Dependent Claim
26 words
A material suitable for the preparation of a vulcanized product, which comprises: a mixture of the thermally modified fluoroelastomer of claim 7 with a cross-linking agent.
Claim 11
Dependent Claim
16 words
The material of claim 8, wherein said mixture further comprises the presence of an auxiliary agent.
Claim 12
Dependent Claim
24 words
A material suitable for the preparation of a molding composition, which comprises: the thermally modified fluoroelastomer of claim 7 in admixture with a filler.
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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) | 1982-04-09 | 1982-10-09 | 1983-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-09 | 1986-10-09 | 1987-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-09 | 1990-10-09 | 1991-04-10 | $7700.00 | Window Closed / Lapsed |