Whitford Corporation

Whitford Plastics Limited

Julie K Wright

Leonard W Harvey

Michael Coates

Andrew J Melville

Joel Ginies

Joel Gines

Robert Iain Whitlow

Blended fluoropolymer compositions are provided. In one embodiment, a liquid dispersion of a first fluoropolymer is blended with a liquid dispersion of a second fluoropolymer. The first fluoropolymer may be polytetrafluoroethylene (PTFE), such as a low molecular weight PTFE (LPTFE) that has been polymerized via a dispersion or emulsion polymerization process, and which has not been agglomerated, irradiated, or thermally degraded. The LPTFE may be in the form of an aqueous dispersion, having a mean particle size of less than 1.0 microns (&#x3bc;m), with the LPTFE having a first melt temperature (T) of 332&#xb0; C. or less. The second fluoropolymer may be a melt processable fluoropolymer (MPF), such as fluorinated ethylene propylene (FEP), in the form of an aqueous dispersion, and having a mean particle size of less than 1.0 microns (&#x3bc;m). Blending of the dispersions facilitates interaction of the LPTFE and MPF on a submicron level to facilitate intimate blending such that, when the blended fluoropolymer composition is dried, a crystal structure representing a true alloy of the fluoropolymers is formed, having melt characteristics that differ from those of the individual fluoropolymers. The blended fluoropolymer composition may be used to provide a coating having improved impermeability, stain resistance, abrasion resistance, smoothness, and higher contact angles.

Blended fluoropolymer compositions

Blended fluoropolymer compositions are provided, in which a liquid dispersion of a first fluoropolymer is blended with a liquid dispersion of a second fluoropolymer. The first fluoropolymer may be polytetrafluoroethylene (PTFE), such as a low molecular weight PTFE (LPTFE) in the form of an aqueous dispersion having a mean particle size of less than 1.0 microns (&#x3bc;m) and a first melt temperature (T) of 332&#xb0; C. or less. The second fluoropolymer may be a melt processable fluoropolymer (MPF), such as methylfluoroalkoxy (MFA), fluorinated ethylene propylene (FEP), or perfluoroalkoxy (PFA), for example, in the form of an aqueous dispersion having a mean particle size of less than 1.0 microns (&#x3bc;m). When the blended fluoropolymer composition is dried, a crystal structure representing a true alloy of the fluoropolymers is formed, having melt characteristics that differ from those of the individual fluoropolymers.

Blended fluoropolymer compositions are provided. In one embodiment, a liquid dispersion of a first fluoropolymer is blended with a liquid dispersion of a second fluoropolymer. The first fluoropolymer may be polytetrafluoroethylene (PTFE), such as a low molecular weight PTFE (LPTFE) that has been polymerized via a dispersion or emulsion polymerization process, and which has not been agglomerated, irradiated, or thermally degraded. The LPTFE may be in the form of an aqueous dispersion, having a mean particle size of less than 1.0 microns (&#x3bc;m), with the LPTFE having a first melt temperature (T) of 332&#xb0; C. or less. The second fluoropolymer may be a melt processible fluoropolymer (MPF), such as methylfluoroalkoxy (MFA), fluorinated ethylene propylene (FEP), or perfluoroalkoxy (PFA), for example, in the form of an aqueous dispersion, and having a mean particle size of less than 1.0 microns (&#x3bc;m). Blending of the dispersions facilitates interaction of the LPTFE and MPF on a submicron level to facilitate intimate blending such that, when the blended fluoropolymer composition is dried, a crystal structure representing a true alloy of the fluoropolymers is formed, having melt characteristics that differ from those of the individual fluoropolymers. The blended fluoropolymer composition may be used to provide a coating having improved impermeability, stain resistance, abrasion resistance, smoothness, and higher contact angles.

A method for the preparation of a modified fluoropolymer powdered material is disclosed. A suspension of solid fluoropolymer particles together with PTFE particles in an aqueous carrier, is frozen and the frozen carrier is then removed by sublimation at sub-atmospheric pressure to produce a dry powder of modified fluoropolymer particles.

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Widnes, United Kingdom

Julie K Wright