Abstract: 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—CF2-0-(CF20) n(CF2CF20)m-CF2—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 —N(R?n)4, wherein R?n, equal or different at each occurrence, is a hydrogen atom or a C1-C6hydrocarbon group, preferably an alkyl group; n? and m? are independently integers >0 such that the number average molecular weight of the surfactant (PFPE) is of

Abstract: 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.

Abstract: 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—CF2-0-(CF20) n(CF2CF20)m-CF2—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 —N(R?n)4, wherein R?n, equal or different at each occurrence, is a hydrogen atom or a C1-C6hydrocarbon group, preferably an alkyl group; n? and m? are independently integers >0 such that the number average molecular weight of the surfactant (PFPE) is of

Abstract: The invention pertains to a tetrafluoroethylene (TFE) copolymer comprising recurring units derived from at least one perfluoroalkyl(oxy)vinylether of formula CF2?CF—O—Rf, wherein Rf is a C1-C6 perfluoroalkyl 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.

Abstract: The invention pertains to a tetrafluoroethylene (TFE) copolymer comprising recurring units derived from at least one perfluoroalkyl(oxy)vinylether of formula CF2?CF—O—Rf, wherein Rf is a C1-C6 perfluoroalkyl 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.

Abstract: 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.

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

Abstract: A process to substantially remove fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps: a) addition to the fluoropolymer dispersion of one or more non fluorinated surfactants; b) contact of the dispersion with an anionic exchanger; c) separation of the dispersion from the anionic exchanger and recovery of the dispersion substantially fluorinated anionic surfactant free.

Abstract: 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?-(P1)n-CH(Y)-(P2)n?-Y???(1) wherein: Y, Y? and Y? are anionic or nonionic groups, with the proviso that at least one of Y, Y? or Y? is an anionic group and at least one of the remaining of Y, Y? or Y? is a nonionic group; p1 and p2, equal or different, are linear or branched alkylene groups, optionally containing one or more unsaturations, having a number of carbon atoms from 1 to 10, preferably from 1 to 6; n and n? equal or different, are zero or 1.

Abstract: A process for preparing fluoropolymer dispersions, substantially free from anionic fluorinated surfactants, and with a coagulum amount <0.1% by weight, comprising: a) step a1) addition of: a non ionic surfactant having cloud point (CP) between 40° and 80° C., in an amount from 1.5% to 50% by weight on the dispersion fluoropolymer; and optionally an electrolyte to bring the specific conductivity of the dispersion to values in the range 130-8,000 ?S/cm; optionally a buffer agent to have a pH between 2 and 12 to a fluoropolymer dispersion obtainable by an emulsion polymerization process; step a2): heating of the dispersion obtained in a1) up to a temperature Tc in the range CP±10° C.; decantation without stirring, at the temperature Tc, until obtaining the dispersion separation in two aqueous phases, of which the lower one containing the fluoropolymer is discharged; b) step b1): the dispersion obtained in step a2) is optionally additioned of an electrolyte and of a non ionic surfactant as in a1).

Abstract: A process to substantially remove the fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps: a) addition to the fluoropolymer dispersion of an anionic polyelectrolyte; b) contact of the dispersion with an anionic exchanger; c) separation of the dispersion from the anionic exchanger and recovery of the dispersion substantially fluorinated anionic surfactant free.

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

Abstract: A process to substantially remove the fluorinated anionic surfactants comprising the following steps: a) addition to a fluoropolymer dispersion of a nonionic surfactant, in an amount in the range 1.5%–25% by weight, referred to the fluoropolymer weight; b) addition to the dispersion of a salt, soluble in water and not giving precipitates in the dispersion under the use conditions; c) contact of the dispersion with a basic anionic exchanger; d) separation of the dispersion from the basic anionic exchanger; before step d) the dispersion being filterable on a 180 micrometer net and successively on a 10 micrometer net.

Abstract: A process to substantially remove fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps: a) addition to the fluoropolymer dispersion of one or more non fluorinated surfactants; b) contact of the dispersion with an anionic exchanger; c) separation of the dispersion from the anionic exchanger and recovery of the dispersion substantially fluorinated anionic surfactant free.

Abstract: A process to substantially remove the fluorinated anionic surfactants from fluoropolymer dispersions comprising the following steps: a) addition to the fluoropolymer dispersion of an anionic polyelectrolyte; b) contact of the dispersion with an anionic exchanger; c) separation of the dispersion from the anionic exchanger and recovery of the dispersion substantially fluorinated anionic surfactant free.

Abstract: Mixtures of fluoropolymer dispersion, wherein: a) a dispersion is formed by TFE (co)polymers with average particle sizes in the range 180–400 nm; b) another dispersion selected from: 1) (co)polymer dispersion of TFE; 2) thermoplastic copolymers of TFE; the average particle sizes of dispersion b) range from 20 to 60 nm; the ratio between the particle sizes of dispersion b) compared with those of dispersion a) is lower than 0.3.

Abstract: A process to substantially remove the fluorinated anionic surfactants comprising the following steps: a) addition to a fluoropolymer dispersion of a nonionic surfactant, in an amount in the range 1.5%-25% by weight, referred to the fluoropolymer weight; b) addition to the dispersion of a salt, soluble in water and not giving precipitates in the dispersion under the use conditions; c) contact of the dispersion with a basic anionic exchanger; d) separation of the dispersion from the basic anionic exchanger; before step d) the dispersion being filterable on a 180 micrometer net and successively on a 10 micrometer net.

Abstract: 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?—(P1)n—CH(Y)—(P2)n?—Y? ??(1) wherein: Y, Y? and Y? are anionic or nonionic groups, with the proviso that at least one of Y, Y? or Y? is an anionic group and at least one of the remaining of Y, Y? or Y? is a nonionic group; p1 and p2, equal or different, are linear or branched alkylene groups, optionally containing one or more unsaturations, having a number of carbon atoms from 1 to 10, preferably from 1 to 6; n and n? equal or different, are zero or 1.

Abstract: A process for preparing fluoropolymer dispersions, substantially free from anionic fluorinated surfactants, and with a coagulum amount <0.1% by weight, comprising: a) step a1) addition of: a non ionic surfactant having cloud point (CP) between 40° and 80° C., in an amount from 1.5% to 50% by weight on the dispersion fluoropolymer; and optionally an electrolyte to bring the specific conductivity of the dispersion to values in the range 130-8,000 ?S/cm; optionally a buffer agent to have a pH between 2 and 12 to a fluoropolymer dispersion obtainable by an emulsion polymerization process; step a2): heating of the dispersion obtained in a1) up to a temperature Tc in the range CP±10° C.; decantation without stirring, at the temperature Tc, until obtaining the dispersion separation in two aqueous phases, of which the lower one containing the fluoropolymer is discharged; b) step b1): the dispersion obtained in step a2) is optionally additioned of an electrolyte and of a non ionic surfactant as in a1).

Abstract: Fluoropolymer aqueous dispersions having particles with average diameters from 150 to 400 nm, comprising bifunctional fluorinated surfactants having formula: A-Rf—B??(I) wherein: A and B, equal to or different from each other, are: —(O)pCFX—COOM; M=NH4, alkaline metal, H; X=F, CF3; p is an integer equal to 0 or 1; Rf is a linear or branched perfluoroalkyl chain, or a (per)fluoropolyether chain such that the number average molecular weight of (I) is in the range 300-1,800.