EP0072659A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Continuous polymerization process
Assignee: EIDP Inc
•
Filing: 1982-08-10
•
Granted: —
•
Expires: 2002-08-10
Abstract
Abstract A process for polymerizing tetrafluoroethylene alone or with selected comonomers in an aqueous polymerization medium is rendered continuous by the use of a perfluoroalkyl ethane sulfonic acid or salt thereof or a perfluoroalkyl ethane sulfate salt as dispersing agent.
Inventors
- 👤 Ausat Ali Khan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:00
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
142 words
A process for polymerizing tetrafluoroethylene, optionally with at least one copolymerizable fluorinated ethylenically unsaturated comonomer, in the presence of a dispersing agent, characterised in that polymerization is carried out continuously by feeding tetrafluoroethylene alone or with at least one said comonomer into an aqueous polymerization medium containing a free radical initiator and 0.5 to 3.0 percent, based on the weight of aqueous medium, of, as dispersing agent, 1) a mixture of compounds of the formula wherein n is a cardinal number of 2 to 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 from 2 to 6; and Y is -S0 3 M or -OSO 3 M' wherein M is a cation having a valence of 1 and M' is an alkali metal cation or ammonium.
Claim 2
Dependent Claim
142 words
A process for polymerizing tetrafluoroethylene, optionally with at least one copolymerizable fluorinated ethylenically unsaturated comonomer, in the presence of a dispersing agent, characterised in that polymerization is carried out continuously by feeding tetrafluoroethylene alone or with at least one said comonomer into an aqueous polymerization medium containing a free radical initiator and 0.5 to 3.0 percent, based on the weight of aqueous medium, of, as dispersing agent, 1) a mixture of compounds of the formula wherein n is a cardinal number of 2 to 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 from 2 to 6; and Y is -S0 3 M or -OSO 3 M' wherein M is a cation having a valence of 1 and M' is an alkali metal cation or ammonium.
Claim 3
Dependent Claim
97 words
A process according to claim 1 wherein the at least one copolymerizable comonomer comprises a fluorinated ethylenically unsaturated comonomer of the formula wherein R 1 is -R f , -R f ,X, -0-R f , or -0-R f ,X in which R f is a perfluoroalkyl radical of 1 to 12 carbon atoms, -R f , is a linear perfluoroalkylene diradical of 1 to 12 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
15 words
A process according to claim 2 wherein the unsaturated comonomer is a perfluoro(alkyl vinyl ether).
Claim 5
Dependent Claim
13 words
A process according to claim 3 wherein the comonomer is perfluoro(propyl vinyl ether).
Claim 6
Dependent Claim
16 words
'5. A process according to claim 2 wherein the unsaturated comonomer is a perfluoro(terminally unsaturated olefin).
Claim 7
Dependent Claim
13 words
A process according to claim 2 wherein the comonomer is a perfluoroalkyl ethylene.
Claim 8
Dependent Claim
11 words
A process according to claim 2 wherein the comonomer is hexafluoropropylene.
Claim 9
Dependent Claim
18 words
A process according to claim 2 wherein the comonomer is a mixture of hexafluoropropylene and perfluoro(propyl vinyl ether).
Claim 10
Dependent Claim
26 words
A process according to any one of the preceding claims wherein M is H + , NH4, Na + , Li + or K + .
Claim 11
Dependent Claim
23 words
A process according to any one of the preceding claims wherein the aqueous medium contains 0.5 to 2.0 percent by weight dispersing agent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.