Polymer composition with uniformly distributed nano-sized inorganic particles

Abstract

The present invention provides a polymer composition wherein inorganic particles are uniformly dispersed at the nano level in the polymer without having said inorganic particles being surface-treated. It further provides a method for manufacturing a polymer composition wherein a co-aggregate which is obtained by uniformly mixing polymer dispersion with an inorganic particle colloidal solution and co-aggregating the polymer primary particles and inorganic particles which are heterogeneous particles, is separated from the solvent and dried so that the inorganic particles are uniformly dispersed at the nano level in the polymer; and the polymer composition which is obtained by said method.

1 . A method for making a polymer composition, comprising mixing aqueous polymer dispersion comprising polymer primary particles with an aqueous colloidal solution of spherical inorganic particles having an average diameter of 10 to 300 nm, said inorganic particles being hydrophilic and stably dispersed in said solution, the ratio (D inorganic/ D polymer ) of the average particle diameter (D inorganic ) of said inorganic particles to the average primary particle diameter (D polymer ) of said polymer primary particles being 0.1 to 2.0, wherein said inorganic particles are present in 0.1 to 40 wt % based on the combined weight of said polymer and said inorganic particles coagulating the resultant mixture to make a co-aggregate of the polymer primary particles with said inorganic particles, separating said co-aggregate, and drying said co-aggregate. 
   
   
       2 . The method  claim 1  wherein said coagulating is achieved by shearing, adding electrolyte to, or freezing the resultant mixture. 
   
   
       3 . The method of  claim 1  wherein said inorganic particles of said colloidal solution are selected from at least one of the group consisting of the silicon oxide, titanium oxide, aluminum oxide, and zinc antimonate. 
   
   
       4 . (canceled) 
   
   
       5 . The method of  claim 1  wherein the polymer of said polymer dispersion is a polymer or copolymer of monomers which are selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, perfluoro(alkyl vinyl ether), vinylidene fluoride and vinyl fluoride or a copolymer of ethylene or propylene with at least one of the monomers selected from the group consisting tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, perfluoro(alkyl vinyl ether), vinylidene fluoride and vinyl fluoride. 
   
   
       6 . A polymer composition made by the method, comprising mixing aqueous polymer dispersion comprising polymer primary particles with an aqueous colloidal solution of spherical inorganic particles having an average diameter of 10 to 300 nm, said inorganic particles being hydrophilic and stably dispersed in said solution, the ratio (D inorganic /D polymer ) of the average particle diameter (D inorganic ) of said inorganic particles to the average primary particle diameter (D polymer ) of said polymer primary particles being 0.1 to 2.0, wherein said inorganic particles are present in 0.1 to 40 wt % based on the combined weight of said polymer and said inorganic particles, coagulating the resultant mixture to make a co-aggregate of the polymer primary particles with said inorganic particles, separating said co-aggregate, and drying said co-aggregate. 
   
   
       7 . The polymer composition of  claim 6  wherein the ratio (V 0.1 /V 1 ) of the melt viscosity (V 0.1 ) at 0.1 rad/sec to the melt viscosity (V 1 ) at 1 rad/sec is 1.4 or greater, said melt viscosities being measured at 340° C. by the parallel-plate mode of a dynamic viscosity and elasticity measuring device. 
   
   
       8 . The polymer composition of  claim 6  wherein the storage elastic modulus at 200° C. is greater than 1.7 times than that of the polymer or copolymer by itself. 
   
   
       9 . (canceled) 
   
   
       10 . A granulated powder which is obtained by granulating the polymer composition of  claim 6 . 
   
   
       11 . A pellet which is obtained by melt-extruding the polymer composition of  claim 6 . 
   
   
       12 . A composition obtained by melt-mixing polymer composition derived from the method of  claim 1 . 
   
   
       13 . The method of  claim 1  further comprising melt processing said composition as said co-aggregate, or as granules or pellets of said co-aggregate. 
   
   
       14 . The method of  claim 1  further comprising compression molding said composition as said co-aggregate, or as granules of said co-aggregate. 
   
   
       15 . A transparent molded article of the composition of  claim 6 . 
   
   
       16 . (canceled) 
   
   
       17 . The polymer composition of  claim 6  wherein said aqueous colloidal solution of inorganic particles is a silica sol. 
   
   
       18 . (canceled)