Whitford Corporation

3m Innovative Properties Company

Ici Americas, Inc.

Whitford Plastics Limited

Lenford, Inc.

Leonard W Harvey

Michael Coates

Helen L Brain

Julie K Wright

Michael C Dadalas

Lawrence D Leech

Friedrich Kloos

Michael J Lindstrom

Thomas James Bate

Rebekka Epsch

Susan J Roberts-Bleming

Andrew J Melville

Daniel C Chung

Anita K Peacock

Joel Ginies

Eric N Martin

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 that, in one exemplary application, may be applied as a coating to a flexible substrate and, optionally, to a flexible substrate that has been previously coated with a primer or basecoat and/or a midcoat. In one embodiment, the composition is a blend of at least one low molecular weight polytetrafluoroethyelene (LPTFE) and at least one melt-processible fluoropolymer (MPF). In another embodiment, the composition includes a fluoropolymer base component including at least one fluoropolymer such as high molecular weight polytetrafluoroethylene (HPTFE), and additionally includes the LPTFE/MPF blended fluoropolymer composition. After being applied to the flexible substrate, optionally over a primer or basecoat and/or midcoat, and then cured, the present compositions form coatings that demonstrate improved abrasion resistance and/or improved release characteristics and/or increased translucency/transparency and/or improved impermeability. The present compositions may also be used to produce films having a high degree of clarity and impermeability. The present compositions in powder form may be melt or paste extruded to form articles with improved impermeability.

Blended fluoropolymer compositions and coatings for flexible substrates

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.

Fluoropolymer compositions that include multiple fluoropolymer components and, in exemplary applications, may be applied as coatings to either rigid or flexible substrates. The compositions may themselves be applied as basecoats or overcoats, or may be combined with other components to formulate basecoats or overcoats. In one embodiment, the compositions include at least one low molecular weight polytetrafluoroethylene (LPTFE) and at least two chemically different melt processible fluoropolymers (MPF). In another embodiment, the compositions include at least one high molecular weight polytetrafluoroethylene (HPTFE), at least one low molecular weight polytetrafluoroethylene (LPTFE), and at least two chemically different melt processible fluoropolymers (MPF). After being applied to a substrate, optionally over a basecoat and/or a midcoat and then cured, the present compositions form coatings that demonstrate improved characteristics, such as improved release characteristics, abrasion resistance, translucency/transparency, and permeability, for example.

Blended fluoropolymer compositions having multiple melt processible 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.

The present invention provides a fluoropolymer dispersion comprising fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water whereby the dispersion is free of fluorinated surfactant having a molecular weight of less than 1000 g/mol or contains the fluorinated surfactant having a molecular weight of less than 1000 g/mol in an amount of not more than 0.025% by weight based on the total weight of solids in the dispersion. The dispersion further comprises a non-ionic surfactant and an anionic surfactant selected from fluorinated anionic surfactants having a molecular weight of at least 1000 g/mol, non-fluorinated anionic surfactants and mixtures thereof.

Fluoropolymer dispersion containing no or little low molecular weight fluorinated surfactant

Blended fluoropolymer compositions that, in one exemplary application, may be applied as a coating to a substrate and, optionally, may be applied to a substrate that has been previously coated with a primer or basecoat and/or a midcoat. In one embodiment, the composition is a blend of at least one high molecular weight trace modified polytetrafluoroethyelene (TMHPTFE) and at least one melt-processible fluoropolymer (MPF). After being applied to the substrate, optionally over a primer or basecoat and/or midcoat, and then cured, the present compositions form coatings that demonstrate improved abrasion resistance and/or improved release characteristics and/or increased translucency/transparency and/or improved impermeability. The present compositions may also be used to produce films having a high degree of clarity and impermeability. The present compositions in powder form may be melt or paste extruded to form articles with improved impermeability.

Fluoropolymer coating compositions

Blended fluoropolymer compositions that may be applied as a coating to a flexible substrate. The compositions include at least one high molecular weight polytetrafluoroethylene (HPTFE), at least one a low molecular weight polytetrafluoroethylene (LPTFE) and at least one melt processible fluoropolymer (MPF). After being applied to the flexible substrate, optionally over a primer or basecoat and/or midcoat and then cured, the compositions form coatings that demonstrate improvement in one or more of abrasion resistance, release characteristics, translucency/transparency, and impermeability.

A fluoropolymer coating composition that may be applied over a primer and/or at least one midcoat in a non-stick coating system. The coating composition may be prepared and applied in the form of a liquid dispersion, and includes at least one fluoropolymer base component, such as polytetrafluoroethylene (PTFE) and, in particular, at least one high molecular weight PTFE (HPTFE). The coating composition additionally includes a blended fluoropolymer composition. The blended fluoropolymer composition is a blend of at least one low molecular weight PTFE (LPTFE) and at least one melt-processible fluoropolymer. After application directly to a substrate or over an underlying coating, the coating demonstrates improved abrasion and scratch resistance, as well as improved release characteristics, as compared to known coatings that include only HPTFE or HPTFE with a small amount of melt processible fluoropolymer.

Blended fluoropolymer coatings for rigid substrates

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.

Method for the preparation of fluoropolymer powdered materials

Devices and methods for applying vibrations to the iron sole of an ironing appliance to facilitate the movement of the iron sole over a fabric, thereby improving the effectiveness of the ironing appliance in removing wrinkles, especially on thicker fabrics.

Devices and methods of facilitating cooking and ironing using vibration pulses

Fluoropolymer dispersions containing no or little low molecular weight fluorinated surfactant

In an aspect of the invention, a fluoropolymer dispersion, preferably a PTFE dispersion, is provided that comprises fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water whereby the dispersion has an amount of solids between 35 and 70% by weight. The dispersion is free of fluorinated surfactant having a molecular weight of less than 1000 g/mol (hereinafter called low molecular weight fluorinated surfactant) or contains the low molecular weight fluorinated surfactant in an amount of not more than 0.05% by weight based on the total weight solids of the dispersion. The dispersion further comprises a non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants and one or more non-fluorinated anionic surfactants. Through the use of a non-fluorinated anionic surfactant, a dispersion is obtained that has a low viscosity at room temperature (20&#xb0; C.). The dispersion is further free of aromatic group containing non-ionic surfactants and is accordingly environmentally more friendly and can yield coatings that are less susceptible of discoloration. The amount and nature of the non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants is selected such that the Viscosity Transition Temperature (VTT) (measured as set forth in the examples) of the fluoropolymer dispersion is at least 26, preferably at least 28&#xb0; C. In a further aspect of the invention, a method is provided to obtain the aforementioned dispersion.

An improved process for preparing free flowing tetrafluoroethylene (TFE) polymer powders is disclosed in which a TFE polymer powder is (1) wetted with an aqueous solution containing a wetting agent selected from the group consisting of (a) ethylene glycol ethers, (b) propylene glycol ethers and (c) diols or triols, (2) agglomerated and (3) dried.

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Downingtown, PA, United States of America

Leonard W Harvey