Patent US4381384A successfully refreshed from Google Patents.
US4381384A
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Continuous polymerization process
Assignee: EIDP Inc
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Filing: 1981-08-17
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Granted: 1983-04-26
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Expires: 2001-08-17
Abstract
Abstract A continuous process for polymerizing tetrafluoroethylene alone or with selected comonomers to prepare a polymer which employs a perfluoroalkyl ethane sulfonic acid or its salt or a perfluoroalkyl ethane sulfate salt as dispersing agent.
Inventors
- 👤 Ausat A. Khan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:43
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
160 words
A continuous process for preparing tetrafluoroethylene homopolymer or copolymers of tetrafluoroethylene and at least one copolymerizable fluorinated ethylenically unsaturated comonomer which comprises feeding tetrafluoroethylene alone or with at least one said comonomer present in an amount sufficient to produce a comonomer unit content in the copolymer of between 0.005 mole percent and 20 mole percent, into an aqueous polymerization medium containing a free radical initiator and 0.5-3.0 percent dispersing agent, based on weight of aqueous medium, in which the dispersing agent is (1) a mixture of compounds of the formula F--CF.sub.2 --CF.sub.n CH.sub.2 --CH.sub.2 --Y wherein n is a cardinal number of 2-8 and the average value of n is between 3 and 6, or (2) a compound of said formula wherein n is a cardinal number selected from between 2-6; and Y is --SO 3 M or --OSO 3 M' wherein M is a cation having the valence of 1 and M' is an alkali metal cation or ammonium.
Claim 2
Dependent Claim
160 words
A continuous process for preparing tetrafluoroethylene homopolymer or copolymers of tetrafluoroethylene and at least one copolymerizable fluorinated ethylenically unsaturated comonomer which comprises feeding tetrafluoroethylene alone or with at least one said comonomer present in an amount sufficient to produce a comonomer unit content in the copolymer of between 0.005 mole percent and 20 mole percent, into an aqueous polymerization medium containing a free radical initiator and 0.5-3.0 percent dispersing agent, based on weight of aqueous medium, in which the dispersing agent is (1) a mixture of compounds of the formula F--CF.sub.2 --CF.sub.n CH.sub.2 --CH.sub.2 --Y wherein n is a cardinal number of 2-8 and the average value of n is between 3 and 6, or (2) a compound of said formula wherein n is a cardinal number selected from between 2-6; and Y is --SO 3 M or --OSO 3 M' wherein M is a cation having the valence of 1 and M' is an alkali metal cation or ammonium.
Claim 3
Dependent Claim
77 words
The process of claim 1 wherein the copolymerizable comonomer is a fluorinated ethylenically unsaturated comonomer of the formula ##STR2## wherein R 1 is --R f , --R f 'X, --O--R f or --O--R f 'X in which R f is a perfluoroalkyl radical of 1-12 carbon carbon atoms in which the attaching valences are at each end of the linear chain, and X is H or Cl; and R 2 is R f or --R f' X.
Claim 4
Dependent Claim
13 words
The process of claim 1 or 2 wherein Y is --OSO 3 M'.
Claim 5
Dependent Claim
13 words
The process of claim 1 or 2 wherein Y is --SO 3 M.
Claim 6
Dependent Claim
24 words
The process of claim 4 wherein M is H + , NH 4 + , Na + , Li + or K + .
Claim 7
Dependent Claim
20 words
The process of claim 2 wherein the unsaturated comonomer has the formula ##STR3## wherein R 1 is --OR f .
Claim 8
Dependent Claim
20 words
The process of claim 2 wherein the unsaturated comonomer has the formula ##STR4## wherein R 1 is R f .
Claim 9
Dependent Claim
19 words
The process of claim 2 wherein the comonomer has the formula ##STR5## wherein R 1 is R f .
Claim 10
Dependent Claim
12 words
The process of claim 1 or 2 wherein the comonomer is hexafluoropropylene.
Claim 11
Dependent Claim
14 words
The process of claim 1 or 2 wherein the comonomer is perfluoro(propyl vinyl ether).
Claim 12
Dependent Claim
19 words
The process of claim 1 or 2 wherein the comonomer is a mixture of hexafluoropropylene and perfluoro(propyl vinyl ether).
Claim 13
Dependent Claim
16 words
The process of claim 1 wherein the aqueous medium contains 0.5-2.0 percent by weight dispersing weight.
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) | 1986-04-25 | 1986-10-25 | 1987-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-25 | 1990-10-25 | 1991-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-25 | 1994-10-25 | 1995-04-26 | $7700.00 | Window Closed / Lapsed |