Abstract An improved process for the production of aqueous colloidal dispersions of tetrafluoroethylene polymer wherein tetrafluoroethylene monomer is polymerized in the presence of water, a catalyst and a dispersing agent. The improvement comprising progressively introducing tetrafluoroethylene monomer and a dispersing agent into a reaction vessel wherein a small concentration of dispersing agent is present prior to the beginning of polymerization, at a rate which provides a concentration of dispersing agent which at each instant does not exceed by more than 10 percent the theoretical concentration required to provide continuous coverage of the entire surface of the polymerized particles formed with dispersing agent but which is sufficient to provide continuous coverage of at least 60 percent of the surface of said particles with dispersing agent.
Inventors
👤 Edouard Grimaud
👤 Pierre Plurien
👤 Maurice Troussier
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-31 16:36
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
34 words
The process of claim 1 wherein the dispersing agent consists of an alkali or ammonium salt of a fluoric or chlorofluoric aliphatic carboxylic acid having a chain length of at least 6 carbon atoms.
Claim 2
Dependent Claim
19 words
The process of claim 1 wherein the polymerization is carried out at a pressure between 5 and 25 atmospheres.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the monomer and dispersing agent are added in successive doses.
Claim 4
Dependent Claim
32 words
The process of claim 1 wherein the dispersing agent is produced in situ from a compound present in the reaction vessel and a compound which is added in the course of polymerization.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein the catalyst is a mineral redox system comprising potassium persulfate and ferrous sulfate.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the the catalyst is an organic peroxide.
Claim 7
Dependent Claim
17 words
The process of claim 1 wherein the polymerization is carried out in the presence of paraffin oil.