Abstract: The invention relates to a process for producing free-flowing calcium fluoride particles from a diluted aqueous solution of hydrogen fluoride comprising the step of reacting the diluted aqueous solution of hydrogen fluoride with calcium carbonate particles at a temperature of less than 50° C. The invention further relates to the use of the free-flowing calcium fluoride particles for the manufacturing of anhydrous hydrogen fluoride.

Abstract: The invention relates to a process for producing free-flowing calcium fluoride particles from a diluted aqueous solution of hydrogen fluoride comprising the step of reacting the diluted aqueous solution of hydrogen fluoride with calcium carbonate particles at a temperature of less than 50° C. The invention further relates to the use of the free-flowing calcium fluoride particles for the manufacturing of anhydrous hydrogen fluoride.

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 fully fluorinated alkylene group, Rf represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one oxygen atom, 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: A method for preparing saturated partially fluorinated alkoxy carboxylic acids or salts thereof by treating a compound: (II), where Rf represents a fluorinated, linear or branched alkyl residue interruptible by one or more oxygen atoms, n is 0 or 1, with a Z-anion in a reaction medium comprising water and an organic solvent, where the Z-anion is selected from CN—, SCN— and OCN— or combinations thereof. A method of making partially fluorinated ethers of the general formula (I) wherein Rf is defined as above, n is 0 or 1, and Z is nitrile (—CN), azide (—N3), thiocyanate (—SCN) or cyanate (—OCN) group, said method comprising treating a fluorinated olefin of the general formula (II) wherein the Z-anion is CN—, OCN—, SCN— or N3?. A compound of the general formula (I) as previously described where Z is selected from SCN, OCN and N3.

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 fully fluorinated alkylene group, Rf represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one oxygen atom, 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: 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 fully fluorinated alkylene group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one oxygen atom, 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: A method for preparing saturated partially fluorinated alkoxy carboxylic acids or salts thereof by treating a compound: (II), where Rf represents a fluorinated, linear or branched alkyl residue interruptible by one or more oxygen atoms, n is 0 or 1, with a Z-anion in a reaction medium comprising water and an organic solvent, where the Z-anion is selected from CN—, SCN— and OCN— or combinations thereof. A method of making partially fluorinated ethers of the general formula (I) wherein Rf is defined as above, n is 0 or 1, and Z is nitrile (—CN), azide (—N3), thiocyanate (—SCN) or cyanate (—OCN) group, said method comprising treating a fluorinated olefin of the general formula (II) wherein the Z-anion is CN—, OCN—, SCN— or N3?. A compound of the general formula (I) as previously described where Z is selected from SCN, OCN and N3.

Abstract: A method for removing a fluorinated carboxylic acid or salt thereof from an aqueous liquid by contacting the aqueous liquid with adsorbent particles. The fluorinated carboxylic acid or salt thereof is selected from the group consisting of partially fluorinated carboxylic acids or salts thereof and fully fluorinated carboxylic acids or salts thereof.

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: A coating composition having (i) an aqueous dispersion of fluoropolymer particles comprising a non-melt processible polymer of tetrafluoroethylene, (ii) a fluorinated surfactant, (iii) a non-ionic non-fluorinated surfactant and (iv) a non-fluorinated polymer, wherein the fluorinated surfactant is selected from fluorinated carboxylic acids or salts thereof of the general formula (I): [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 for polymerizing, in an aqueous medium, at least one fluorinated monomer in the presence of a non-copolymerizable, non-fluorinated surfactant. The surfactant is generally selected from a non-ionic surfactant, a primary anionic surfactant, or a combination thereof. Fluorinated surfactants are not utilized. The resulting partially fluorinated polymer in the aqueous medium is either a semi-crystalline polymer or a crystalline polymer.

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 fully fluorinated alkylene group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one oxygen atom, 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: 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 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 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: Fluorinated ether carboxylic acid or acid derivatives, aqueous compositions comprising fluorinated surfactants, processes for preparing fluoropolymer dispersions, and methods for preparing layered articles.

Abstract: A coating composition having (i) an aqueous dispersion of fluoropolymer particles comprising a non-melt processible polymer of tetrafluoroethylene, (ii) a fluorinated surfactant, (iii) a non-ionic non-fluorinated surfactant and (iv) a non-fluorinated polymer, wherein the fluorinated surfactant is selected from fluorinated carboxylic acids or salts thereof of the general formula (I): [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: 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: A method for polymerizing, in an aqueous medium, at least one fluorinated monomer in the presence of a non-copolymerizable, non-fluorinated surfactant. The surfactant is generally selected from a non-ionic surfactant, a primary anionic surfactant, or a combination thereof. Fluorinated surfactants are not utilized. The resulting partially fluorinated polymer in the aqueous medium is either a semi-crystalline polymer or a crystalline polymer.

Abstract: The invention provides a fluorinated surfactant having the general formula: [Rf—(O)t—CHF—(CF2)n—COO—]iXi+??(I) wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, t is 0 or 1 and n is 0 or 1, Xi+ represents a cation having a valence i and i is 1, 2 or 3. The surfactant can be used in emulsion polymerization of fluoromonomers to prepare fluoropolymers.