US4499249A
Expired / Lapsed
US
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Process for preparing tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer
Assignee: Daikin Industries Ltd
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Filing: 1983-04-28
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Granted: 1985-02-12
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Expires: 2003-04-28
Abstract
Abstract A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer comprising polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1:1 to 10:1 at a temperature of from 0 DEG to 25 DEG C. in the presence of a polymerization initiator of the formula: [Cl(CF2)n-COO]2 (I) wherein n is an integer of 1 to 10, the copolymer obtained by the process having a small number of unstable terminal groups and excellent flex life.
Inventors
- 👤 Shinichi Nakagawa
- 👤 Tsuneo Nakagawa
- 👤 Sadaatsu Yamaguchi
- 👤 Kiyohiko Ihara
- 👤 Toshihiko Amano
- 👤 Mitsugu Omori
- 👤 Kohzoh Asano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:12
CPC Classifications
C; C08; C08F; C08F214/00; C08F214/18; C08F214/26; C08F214/262
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer, comprising: polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), ##STR3## in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1:1 to 10:1 at a temperature of from 0° to 25° C. in the presence of a polymerization initiator of the formula: [Cl(CF.sub.2).sub.n --COO].sub.2 wherein n is an integer of 1 to 10.
Claim 2
Dependent Claim
89 words
A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer, comprising: polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), ##STR3## in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1:1 to 10:1 at a temperature of from 0° to 25° C. in the presence of a polymerization initiator of the formula: [Cl(CF.sub.2).sub.n --COO].sub.2 wherein n is an integer of 1 to 10.
Claim 3
Dependent Claim
26 words
The process according to claim 1, wherein the polymerization initiator is a compound of the formula (I) wherein n is an integer of 1 to 4.
Claim 4
Dependent Claim
19 words
The process according to claim 1, wherein the polymerization initiator is a compound of the formula: [ClCF.sub.2 CF.sub.2 COO].sub.2.
Claim 5
Dependent Claim
21 words
The process according to claim 1, wherein the weight ratio of tetrafluoroethylene and fluoro(alkyl vinyl ehter) is from 1:1 to 10:1.
Claim 6
Dependent Claim
21 words
The process according to claim 1, wherein the volume ratio of water and fluorohydrocarbon or chlorofluorohydrocarbon is from 1.5:1 to 5:1.
Claim 7
Dependent Claim
25 words
The process according to claim 1, wherein the fluorohydrocarbon or the chlorofluorohydrocarbon is selected from the group consisting of 1,1,2,-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, trichlorofluoromethane, dichlorodifluoromethane and perfluorocyclobutane.
Claim 8
Dependent Claim
16 words
The process according to claim 1, wherein the reaction temperature is from 5° to 15° C.
Claim 9
Dependent Claim
18 words
The process according to claim 1, wherein the reaction pressure is from 0.5 to 15 kg/cm 2 G.
Claim 10
Dependent Claim
26 words
The process according to claim 8, wherein the polymerization initiator is a compound of the formula (I) wherein n is an integer of 1 to 4.
Claim 11
Dependent Claim
21 words
The process according to claim 1, wherein the weight ratio of the produced copolymer to the solvent is 0.4 or more.
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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) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |