Fluoropolymer blends with inorganic layered compounds

Abstract

Perfluoropolymer composites are provided which are obtained by dispersing layered-silicates having properties of swelling or cleaving in dispersion media in perfluoropolymers and having the ratio of the viscosity, V 0.1 , at 0.1 rad/sec by a parallel plate mode of a dynamic rheometer to the viscosity, V 1 , measured at 1 rad/sec is 1.5 or greater, viscosity being measured at 340° C. A method for making the perfluoropolymer composites is provided, and molded articles therefrom. And additionally, perfluoropolymer composites, where layered-silicates having properties of swelling or cleaving in dispersion media are dispersed in perfluoropolymers, with the storage elasticity of 2 times or higher than that of fluoropolymers, at temperatures greater than the glass transition temperature of perfluoropolymers.

1 . Perfluoropolymer composite obtained by dispersing layered-silicate having properties of swelling or cleaving in dispersion media, in perfluoropolymer wherein the layer thickness of said layered-silicate in said composite is less than about 100 nm. 
   
   
       2 . The composite of  claim 1  wherein the ratio of the storage elasticity (G′ S ) of the perfluoropolymer composite to the storage elasticity (G′ F ) of the perfluoropolymer, G′ S /G F ′, is 2 or greater at temperatures greater than the glass transition temperature of the perfluoropolymer. 
   
   
       3 . The composite of  claim 1  wherein the ratio (V 0.1 /V 1 ) of the viscosity (V 0.1 ) measured at 340° C. and 0.1 rad/sec by parallel plate mode of a dynamic rheometer to the viscosity (V 1 ) measured at 340° C. and 1 rad/sec is 1.5 or greater. 
   
   
       4 . The composite of  claim 1  wherein said perfluoropolymer is polymer of monomers selected from tetrafluoroethylene, hexafluoropropylene, and perfluoro(alkyl vinyl ether). 
   
   
       5 . The composite of  claim 1  wherein said layered-silicate having properties of swelling or cleaving in the said dispersion media is at least one layered-silicate selected from the group consisting of smectite-group clay minerals and swelling mica-group clay minerals. 
   
   
       6 . The composite of  claim 1  wherein the content of layered-silicate in said perfluoropolymer composite is 0.5-15% by weight with respect to the perfluoropolymer composite. 
   
   
       7 . The composite of  claim 1  wherein the thickness of layered-silicate dispersed in the perfluoropolymer composites is 100 nm or less. 
   
   
       8 . A method for producing perfluoropolymer composite by mixing a dispersion of perfluoropolymers with a dispersion containing layered-silicate having properties of swelling or cleaving in dispersion media under stirring to obtain mixed aqueous dispersion, agglomerating said mixed aqueous dispersion, separating the aqueous components from the agglomerates, and drying. 
   
   
       9 . The method of  claim 8  wherein the agglomerates are obtained by a method selected from the group consisting of agglomerating through freezing the said mixed aqueous dispersion at a temperature of 0° C. or lower, changing the ionic strength or the pH by adding electrolytes, and by applying shear. 
   
   
       10 . A method for producing perfluoropolymer composite by mixing a dispersion of perfluoropolymers with layered-silicate having properties of swelling or cleaving in dispersion media under stirring to obtain an aqueous dispersion of perfluoropolymer and layered-silicate, agglomerating the mixed aqueous dispersion, separating the aqueous components from the agglomerates, and drying. 
   
   
       11 . The method of  claim 10  wherein the agglomerates are obtained by a method selected from the group consisting of agglomerating through freezing said mixed aqueous dispersion at a temperature of 0° C. or lower, changing the ionic strength or the pH by adding electrolytes, and by applying shear. 
   
   
       12 . Pellets obtained by melt-extruding the perfluoropolymer composite of  claim 1 . 
   
   
       13 . Insulated conductor or jacket for insulated conductor made from the perfluoropolymer composite of  claim 1 . 
   
   
       14 . Tube, sheet, or film made from the perfluoropolymer composite of  claim 1 . 
   
   
       15 . Blow-molded articles from the perfluoropolymer composite of  claim 1 . 
   
   
       16 . Injection molded articles made from the perfluoropolymer composite of  claim 1 .