Patent US1839608A successfully refreshed from Google Patents.
US3968069A
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Positively charged aqueous dispersions of polytetrafluoroethylene and method for preparing the same
Assignee: Produits Chimiques Ugine Kuhlmann
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Filing: 1974-09-11
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Granted: 1976-07-06
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Expires: 1994-09-11
Abstract
Abstract This invention relates to aqueous dispersions of positively charged polytetrafluoroethylene. This inventon also relates to a process for preparing aqueous dispersions of positively charged polytetrafluoroethylene which comprises adding an aqueous dispersion of negatively charged polytetrafluoroethylene containing an anionic emulsifier to an aqueous solution of a cationic emulsifier kept under light agitation while maintaining a ratio of the molar concentration of cationic emulsifier to that of the anionic emulsifier greater than 1:1.
Inventors
- 👤 Edouard Grimaud
- 👤 Claude Tournut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:52
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/02; C08J3/03; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
37 words
A composition consisting essentially of a positively charged aqueous dispersion of solid polytetrafluoroethylene, anionic emulsifier and cationic emulsifier; said cationic emulsifier being present in a molar ratio to the anionic emulsifier that is substantially greater than 1:1.
Claim 2
Dependent Claim
37 words
A composition consisting essentially of a positively charged aqueous dispersion of solid polytetrafluoroethylene, anionic emulsifier and cationic emulsifier; said cationic emulsifier being present in a molar ratio to the anionic emulsifier that is substantially greater than 1:1.
Claim 3
Dependent Claim
46 words
A composition consisting essentially of an aqueous dispersion of solid polytetrafluoroethylene, anionic emulsifier and cationic emulsifier; said cationic emulsifier being present in a molar ratio to the anionic emulsifier that is substantially greater than 1:1 and characterized as non-coagulating upon the effective acidification of the dispersion.
Claim 4
Dependent Claim
46 words
A composition consisting essentially of an aqueous dispersion of solid polytetrafluoroethylene, anionic emulsifier and cationic emulsifier; said cationic emulsifier being present in a molar ratio to the anionic emulsifier that is substantially greater than 1:1 and characterized as non-coagulating upon the effective acidification of the dispersion.
Claim 5
Dependent Claim
15 words
A composition according to claim 1 wherein the pH of the dispersion is approximately neutral.
Claim 6
Independent Claim
66 words
A method for preparing a composition consisting essentially of a positively charged aqueous dispersion of solid polytetrafluoroethylene which comprises adding an aqueous dispersion of negatively charged polytetrafluoroethylene containing an anionic emulsifier to an aqueous solution of a cationic emulsifier kept under light agitation while maintaining a ratio of the molar concentration of cationic emulsifier to that of the anionic emulsifier that is substantially greater than 1:1.
Claim 7
Independent Claim
66 words
A method for preparing a composition consisting essentially of a positively charged aqueous dispersion of solid polytetrafluoroethylene which comprises adding an aqueous dispersion of negatively charged polytetrafluoroethylene containing an anionic emulsifier to an aqueous solution of a cationic emulsifier kept under light agitation while maintaining a ratio of the molar concentration of cationic emulsifier to that of the anionic emulsifier that is substantially greater than 1:1.
Claim 8
Dependent Claim
27 words
The method of claim 4 wherein the ratio of the molar concentration of cationic emulsifier to that of the anionic emulsifier is maintained at greater than 2:1.
Claim 9
Dependent Claim
33 words
The method of claim 4 wherein the cationic emulsifier is a salt of a primary, secondary or tertiary aliphatic amine, an aliphatic quaternary ammonium salt, an alkylbenzylammonium salt or acyclic quaternary ammonium compound.
Claim 10
Dependent Claim
13 words
The method of claim 4 wherein the cationic emulsifier is a dimethylbenzyllaurylammonium halide.
Claim 11
Dependent Claim
13 words
The method of claim 4 wherein the cationic emulsifier is a trimethylcetylammonium halide.
Claim 12
Dependent Claim
28 words
The method of claim 4 wherein the negatively charged aqueous dispersion of polytetrafluoroethylene is directly obtained from the polymerization of tetrafluoroethylene and does not contain a nonionic stabilizer.
Claim 13
Dependent Claim
18 words
The method of claim 4 in which the negatively charged aqueous dispersion of polytetrafluoroethylene contains a non-ionic stabilizer.
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) | 1979-07-06 | 1980-01-05 | 1980-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-06 | 1984-01-05 | 1984-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-06 | 1988-01-05 | 1988-07-06 | $7700.00 | Window Closed / Lapsed |