Solvay Solexis S.p.a.

Solvay Specialty Polymers Italy S.p.a.

Ausimont S.p.a.

Marco Malvasi

Valeri Kapeliouchko

Mario Visca

Valeriy Kapelyushko

Stefana Musio

Daria Lenti

Enrico Marchese

Stefano Vincenzo Radice

Alba Chittofrati

Tiziana Poggio

Stefano Ferrero

The invention pertains to a method for making a fluoropolymer dispersion, said method comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in an aqueous medium comprising a surfactant mixture [mixture (S)] comprising: at least one perfluorohexanoic acid or salt thereof [surfactant (C6)], in an amount of 1 to 5 g/I, with respect to said aqueous medium; and at least one linear bifunctional perfluoropolyether surfactant [surfactant (PFPE)] complying with formula (I) here below: XpOOC&#x2014;CF-0-(CF0)(CFCF0)-CF&#x2014;COOXp (I) wherein: Xp, equal to or different from each other, is a hydrogen atom, a monovalent metal, preferably an alkaline metal, or an ammonium group of formula &#x2014;N(R'), wherein R&#x2032;, equal or different at each occurrence, is a hydrogen atom or a C-Chydrocarbon group, preferably an alkyl group; n&#x2032; and m&#x2032; are independently integers &#x3e;0 such that the number average molecular weight of the surfactant (PFPE) is of 500 to 2500, said surfactant (PFPE) being used in an amount of 0.005 to 0.5 g/I, with respect to said aqueous medium.

Method of making fluoropolymer dispersion

The invention pertains to a tetrafluoroethylene (TFE) copolymer comprising recurring units derived from at least one per(halo)fluoroolefin different from TFE [monomer (F)] [monomer (F)], in an amount of 0.005 to 0.250% moles, with respect to the total moles of the copolymer, wherein a particular relation between monomer content and amorphous index is satisfied, and to a process for its manufacture by emulsion polymerization in the presence of certain cyclic surfactants.

Tetrafluoroethylene copolymers

The invention pertains to a tetrafluoroethylene (TFE) copolymer comprising recurring units derived from at least one perfluoroalkyl(oxy)vinylether of formula CF&#x2550;CF&#x2014;O&#x2014;R, wherein Ris a C-Cperfluoroalkyl radical possibly comprising one or more ethereal oxygen atoms [monomer (F)], in an amount of 0.005 to 0.025% moles, with respect to the total moles of the copolymer, wherein a particular relation between monomer content and amorphous index is satisfied, and to a process for its manufacture by emulsion polymerization in the presence of certain cyclic surfactants.

Fine fluoropolymer powders substantially fluorinated surfactant free, in particular fluorinated ionic surfactants, preferably perfluorooctanoic acid or its salts, comprising an anionic polyelectrolyte.

Fine fluoropolymer powders

A process to substantially remove fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps:

Process for preparing fluoropolymer dispersions

Dispersions of fluorinated polymers substantially free from fluorinated surfactants, having high stability to shear combined with high stability to segregation, said dispersions comprising one or more anionic surfactants having the following general formula (1):Y'-(P)-CH(Y)-(P)-Y&#x2033;&#x2003;&#x2003;(1)wherein:

TFE copolymers

A process for preparing fluoropolymer dispersions, substantially free from anionic fluorinated surfactants, and with a coagulum amount &#x3c;0.1% by weight, comprising: a) step a1) addition of: 

A process to substantially remove the fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps:

A process to substantially remove the fluorinated anionic surfactants comprising the following steps:

Mixtures of fluoropolymer dispersion, wherein:

Fluoropolymer dispersions

Fluoropolymer aqueous dispersions having particles with average diameters from 150 to 400 nm, comprising bifunctional fluorinated surfactants having formula:A-R&#x2014;B&#x2003;&#x2003;(I)wherein:

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Alessandria, Italy

Marco Malvasi