Abstract: The present invention provides a fluorinated surfactant having the general formula: [Rf—(O)t—CQH—CF2—O]n—R-G??(I) wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, Q is CF3 or F, R is an aliphatic or aromatic hydrocarbon group, G represents a carboxylic or sulphonic acid or salt thereof, t is 0 or 1 and n is 1, 2 or 3. The surfactant is particularly useful in polymerizing fluorinated monomers in an aqueous emulsion polymerization.

Abstract: A process for the recovery of fluorinated carboxylic acid or derivative thereof from adsorbent particles on which fluorinated carboxylic acid or a salt thereof is adsorbed. The process includes contacting the adsorbent particles with a liquid composition capable of removing at least part of the fluorinated carboxylic acid or salt thereof from the adsorbent particles. The fluorinated carboxylic acid or salt thereof is selected from the group consisting of fluorinated carboxylic acids or salts thereof that correspond to the general formula: [RfO-L-COO?]iXi+??(I) wherein L represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, Xi? represents a cation having the valence i and i is 1, 2 or 3.

Abstract: A method for removing a fluorinated carboxylic acid or salt thereof from an aqueous liquid by contacting the aqueous liquid with adsorbent particles.

Abstract: The invention relates to an aqueous emulsion polymerization of fluorinated monomers using perfluoropolyethers of the following formula (I) or (II). In particular, the perfluoropolyether surfactants correspond to formula (I) or (II) CF3—(OCF2)m—O—CF2—X??(I) wherein m has a value of 1 to 6 and X represents a carboxylic acid group or salt thereof, CF3—O—(CF2)3—(OCF(CF3)—CF2)z—O-L-Y??(II) wherein z has a value of 0, 1, 2 or 3, L represents a divalent linking group selected from —CF(CF3)—, —CF2— and —CF2CF2— and Y represents a carboxylic acid group or salt thereof. The invention further relates to an aqueous dispersion of a fluoropolymer having the aforementioned perfluoropolyether surfactant(s).

Abstract: A process for recovering a fluorinated carboxylic acid or salts thereof from exhaust gas streams. The process includes contacting the exhaust gas stream with a composition capable of at least partially removing the fluorinated carboxylic acid or salt thereof from the exhaust gas stream. The fluorinated carboxylic acid or salt thereof is selected from the group consisting of fluorinated carboxylic acids or salts thereof that correspond to the general formula: [Rf—O-L-COO?]iXi+??(I) wherein L represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, Xi+ represents a cation having the valence i and i is 1, 2 or 3.

Abstract: A method of making a fluoropolymer dispersion by first providing a fluoropolymer dispersion comprising fluoropolymer particles and one or more fluorinated surfactants selected from fluorinated carboxylic acids or salts thereof having the general formula: [Rf—O-L-COO?]iXi+??(I) wherein L represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, Xi+ represents a cation having the valence i and i is 1, 2 or 3; Then adding one or more non-fluorinated surfactants selected from anionic and non-ionic surfactants followed by reducing the total amount of the one or more fluorinated surfactants to an amount of not more than 500 ppm, for example not more than 250 ppm based on the total weight of the dispersion while maintaining or increasing the amount of solids in the dispersion.

Abstract: The present invention provides an aqueous emulsion polymerization of fluorinated monomers including gaseous fluorinated monomers using a perfluoro ether surfactant as an emulsifier. The perfluoro ether surfactants correspond to formula (I) Rf—O—CF2CF2—X ??(I) wherein Rf represents a linear or branched perfluoroalkyl group having 1, 2, 3 or 4 carbon atoms and X represents a carboxylic acid group or salt thereof. In a further aspect, the invention also provides an aqueous fluoropolymer dispersion comprising the perfluoro ether surfactant and the use of such dispersion in the coating or impregnation of substrates.

Abstract: The present invention relates to a method for making a fluoropolymer comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in the presence of an oligomer that comprises one or more ionic groups, has a partially fluorinated backbone, a number average molecular weight of not more than 2000 g/mol and that has a combination of repeating units different from that of the fluoropolymer that is being produced by the polymerization of said one or more fluorinated monomers. Since the polymerization of the one or more fluorinated monomers to produce the desired fluoropolymer is carried out in the presence of the oligomer, the resulting dispersion will contain the oligomer in addition to the fluoropolymer. Thus, in a further aspect, the invention relates to an aqueous dispersion of a fluoropolymer comprising the oligomer.

Abstract: The invention relates to high purity fluoropolymers and processes for making such materials. These polymers are particularly suited for applications in the semiconductor industry. The process comprises removal of unstable polymer end groups by fluorination and removal of heavy metal impurities by extraction with an aqueous acid medium.

Abstract: An aqueous non-melt processible polytetrafluoroethylene dispersion having non-melt processible polytetrafluoroethylene particles in an amount of 30 to 70% by weight and an amount of non-ionic surfactant between 2 and 15% by weight based on the weight of polytetrafluoroethylene solids. The dispersion is free of fluorinated surfactant or contains fluorinated surfactant in amounts of not more than 200 ppm based on the amount of polytetrafluoroethylene solids. At least part of the non-melt processible polytetrafluoroethylene particles comprise an effective amount of ionic end groups in the polytetrafluoroethylene polymer chains.

Abstract: The present invention provides a method of making an aqueous dispersion of non-melt processible polytetrafluoroethylene, the method comprising: (a) an aqueous emulsion polymerization of an amount of tetrafluoroethylene to produce a final amount of polytetrafluoroethylene solids and optionally up to 1% by weight based on the amount of tetrafluoroethylene of a perfluorinated comonomer, wherein said aqueous emulsion polymerization is initiated with a free radical initiator and the polymerization is carried out in the presence of a fluorinated surfactant, and wherein before completing the feeding of said amount of tetrafluoroethylene but after feeding at least 80% by weight of said amount of tetrafluoroethylene, free radicals capable of introducing ionic end groups or precursors thereof in the polytetrafluoroethylene polymer are caused to be formed at a rate that without counter measures would cause an increase in the polymerization rate of at least 20%; (b) reducing the amount of fluorinated surfactant in the th

Abstract: Provided is a fluoroplastic or latex comprising a nitrogen-containing cure site and units derived from a fluorinated monomer. Also provided is a curable blend comprising a fluoroplastic and a fluoroleastomer gum, wherein said fluoroplastic comprises a nitrogen-containing cure site and units derived from a fluorinated monomer. Also provided are cured, shaped articles, latex blends, and a process for preparing a fluoroplastic comprising: (a) introducing at least 60 weight percent of a first polymerizable composition comprising a fluorinated monomer into a polymerization reactor; (b) polymerizing said composition in said reactor; (c) introducing at least 70 weight percent of a second polymerizable composition comprising a nitrogen-containing cure site monomer into said reactor following addition of at least 80% by weight of said first polymerizable composition; and (d) copolymerizing said nitrogen-containing cure site monomer with said fluorinated monomer to form a fluoroplastic.

Abstract: The present invention provides an aqueous coating composition comprising (i) particles of a non-melt processible polymer of tetrafluoroethylene and (ii) a non-fluorinated polymer selected from the group consisting of a polysulfone, a polyamide, a polyimide, a polyamide-imide, a polybismaleimide and mixtures thereof, wherein said particles are core-shell particles whereby the shell comprises a copolymer of tetrafluoroethylene and a partially fluorinated or non-fluorinated comonomer. The aqueous coating composition may be used for providing a primer coating on a substrate such as a metal or glass substrate. Such primer coating may provide good or excellent non-stick coatings combined with good or excellent scratch and wear resistance of the coating. Also, such primer coating may provide for good to excellent PTFE coatings that can resist hot salt water. The aqueous coating composition may also be used to provide other coating layers of a multi-layer coating.

Abstract: The present invention provides a method of coating a substrate having a surface defined by a layer of fluoropolymer. The method utilizes an aqueous dispersion that includes: particles of melt-processible fluoropolymer in an amount of 30 to 70% by weight; a fluorinated surfactant in an amount of not more than 250 ppm based on fluoropolymer solids of the aqueous dispersion; and a non-ionic surfactant comprising an ethoxylated aliphatic alcohol in an amount of 2 to 15% by weight based on total solids of the aqueous dispersion. The aqueous dispersion is free or substantially free of aromatic group containing non-ionic surfactants. The aqueous dispersion may be optionally diluted and/or modified with additional components to obtain a coating composition. The coating composition may then be applied on at least part of the surface of the substrate to define the fluoropolymer layer.

Abstract: The present invention provides a fluoropolymer that is melt-processible and thermoplastic and that has a melting point between 100° C. and 320° C. The fluoropolymer is derived from (a) one or more gaseous fluorinated monomers, (b) one or more modifiers selected from (i) olefins having a bromine or iodine atom bonded to a carbon of the double bond of the olefin, (ii) olefins corresponding to formula (I): Xa2C?CXa—Rf—Br??(I) wherein each Xa independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rf is a perfluoroalkylene group, typically having 1 to 8 carbon atoms, a perfluorooxyalkylene group or a perfluoropolyether group and (iii) mixtures thereof; and (c) optionally one or more comonomers selected from non-gaseous fluorinated monomers and non-fluorinated monomers. The resulting fluoropolymer has long chain branches. The invention further provides a method for making these polymers.

Abstract: The present invention provides a method of making an aqueous dispersion of non-melt processible polytetrafluoroethylene, the method comprising: (a) an aqueous emulsion polymerization of an amount of tetrafluoroethylene to produce a final amount of polytetrafluoroethylene solids and optionally up to 1% by weight based on the amount of tetrafluoroethylene of a perfluorinated comonomer, wherein said aqueous emulsion polymerization is initiated with a free radical initiator and the polymerization is carried out in the presence of a fluorinated surfactant, and wherein before completing the feeding of said amount of tetrafluoroethylene but after feeding at least 80% by weight of said amount of tetrafluoroethylene, free radicals capable of introducing ionic end groups or precursors thereof in the polytetrafluoroethylene polymer are caused to be formed at a rate that without counter measures would cause an increase in the polymerization rate of at least 20%; (b) reducing the amount of fluorinated surfactant in the th

Abstract: The present invention provides an aqueous non-melt processible polytetrafluoroethylene dispersion comprising non-melt processible polytetrafluoroethylene particles in an amount between 30 and 70% by weight based on the total weight of the dispersion and one or more non-ionic surfactants and wherein at least a part of said non-melt processible polytetrafluoroethylene particles comprise polytetrafluoroethylene polymer chains having repeating units comprising ionic groups. The invention further provides a method for obtaining the dispersions.

Abstract: The present invention provides a fluoropolymer that is melt-processible and thermoplastic and that has a melting point between 100° C. and 320° C.

Abstract: The invention relates to high purity fluoropolymers and processes for making such materials. These polymers are particularly suited for applications in the semiconductor industry. The process comprises removal of unstable polymer end groups by fluorination and removal of heavy metal impurities by extraction with an aqueous acid medium.

Abstract: Provided is a fluoroplastic or latex comprising a nitrogen-containing cure site and units derived from a fluorinated monomer. Also provided is a curable blend comprising a fluoroplastic and a fluoroleastomer gum, wherein said fluoroplastic comprises a nitrogen-containing cure site and units derived from a fluorinated monomer. Also provided are cured, shaped articles, latex blends, and a process for preparing a fluoroplastic comprising: (a) introducing at least 60 weight percent of a first polymerizable composition comprising a fluorinated monomer into a polymerization reactor; (b) polymerizing said composition in said reactor; (c) introducing at least 70 weight percent of a second polymerizable composition comprising a nitrogen-containing cure site monomer into said reactor following addition of at least 80% by weight of said first polymerizable composition; and (d) copolymerizing said nitrogen-containing cure site monomer with said fluorinated monomer to form a fluoroplastic.