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: 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 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 invention provides a layer of fluoropolymer having dispersed therein infrared absorbing particles as a low emissivity layer to reduce the amount of cooling or heating required to maintain a desired temperature for an interior space. The invention also provides a low emittance article comprising a substrate having on at least one major surface thereof at least two layers, the outermost layer of which comprises a fluoropolymer and IR-absorbing particles in the form of flakes distributed in the outermost layer. The invention further provides a composition for producing a low emissivity coating, the composition comprising a dispersion of a fluoropolymer and IR-absorbing particles in the form of flakes. The invention also provides a process for reducing the amount of cooling or heating that is required to maintain a desired temperature for an interior space.

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 invention provides a layer of fluoropolymer having dispersed therein infrared absorbing particles as a low emissivity layer to reduce the amount of cooling or heating required to maintain a desired temperature for an interior space. The invention also provides a low emittance article comprising a substrate having on at least one major surface thereof at least two layers, the outermost layer of which comprises a fluoropolymer and IR-absorbing particles in the form of flakes distributed in the outermost layer. The invention further provides a composition for producing a low emissivity coating, the composition comprising a dispersion of a fluoropolymer and IR-absorbing particles in the form of flakes.

Abstract: Sheet-like structures comprising rubber layers and fluoropolymer layers can be produced by employing, as adhesive layer, a mixture comprising a rubber and a thermoplastic fluoropolymer having a melting point <250.degree. C.