High purity perfluoroelastomer composites and a processes to produce the same

Abstract

High purity perfluoroelastomer composites and processes for producing the same are provided. High purity composites may be formed from compositions comprising a crosslinkable fluoroelastomer terpolymer of TFE, PAVE, and CNVE, and functionalized PTFE, which may be crosslinked to form crosslinked composites having low metal content and low compression set. Emulsion mixtures for forming the high purity composites are also provided.

1 . An emulsion mixture comprising 
 i) a microemulsion of a composition comprising a crosslinkable fluoroelastomer terpolymer consisting essentially of tetrafluoroethylene (TFE), perfluoroalkyl vinyl ether (PAVE), and perfluorocyano vinyl ether (CNVE) monomer units, and    ii) a microemulsion comprising a functionalized polytetrafluoroethylene (PTFE) polymer comprising 0.1 to 3 mol % perfluorocyano vinyl ether (CNVE),    wherein the particle size of the functionalized PTFE polymer is about 10 nm to 100 nm and wherein a composite comprising functionalized PTFE-crosslinkable fluoroelastomer terpolymer isolated from this emulsion mixture contains less than 3000 ppb of metals.    
   
   
       2 . The emulsion mixture of  claim 1 , wherein CNVE in the crosslinkable fluoroelastomer terpolymer, is 8-CNVE.  
   
   
       3 . The emulsion mixture of  claim 1 , wherein the CNVE in the functionalized PTFE polymer is 8-CNVE.  
   
   
       4 . The emulsion mixture of  claim 1 , wherein PAVE is perfluoromethyl vinyl ether (PMVE).  
   
   
       5 . The emulsion mixture of  claim 1 , wherein PAVE is perfluoropropyl vinyl ether (PPVE).  
   
   
       6 . The emulsion mixture of  claim 1 , wherein PAVE is perfluoroethyl vinyl ether (PEVE).  
   
   
       7 . The emulsion mixture of  claim 1 , wherein the functionalized PTFE is about 1 to 20 wt % of a dried composite resulting from the emulsion mixture and the crosslinkable fluoroelastomer terpolymer is about 80 to 99 wt % of the dried composite resulting from the emulsion mixture.  
   
   
       8 . The emulsion mixture of  claim 1 , further comprising at least one additional material selected from fillers and additives.  
   
   
       9 . The emulsion mixture of  claim 1 , wherein at least one filler or additive is in the form of a dispersion.  
   
   
       10 . The emulsion mixture of  claim 1 , further comprising silica in the form of a dispersion.  
   
   
       11 . (canceled)  
   
   
       12 . The emulsion mixture of  claim 1 , wherein the crosslinkable fluoroelastomer composite has less than about 2000 ppb metal content.  
   
   
       13 . The emulsion mixture of  claim 1 , wherein the crosslinkable fluoroelastomer composite has less than about 1000 ppb metal content.  
   
   
       14 . The emulsion mixture of  claim 1 , wherein the crosslinkable fluoroelastomer composite has less than about 500 ppb metal content.  
   
   
       15 . The emulsion mixture of  claim 1 , wherein the crosslinkable fluoroelastomer composite has less than about 200 ppb metal content.  
   
   
       16 . An emulsion mixture comprising 
 i) a microemulsion of a composition comprising a crosslinkable fluoroelastomer terpolymer consisting essentially of tetrafluoroethylene (TFE), perfluoroalkyl vinyl ether (PAVE), and perfluorocyano vinyl ether (CNVE) monomer units, and    ii) a dispersion of at least one additional material selected from filler and additives.    
   
   
       17 . The emulsion of  claim 16 , wherein the at least one additional material comprises a dispersion of silica.  
   
   
       18 . The emulsion of  claim 16 , wherein CNVE is 8-CNVE.  
   
   
       19 . The emulsion mixture of  claim 16 , wherein a crosslinkable fluoroelastomer composite formed from the emulsion mixture has less than about 3000 ppb metal content.  
   
   
       20 . The emulsion mixture of  claim 16 , wherein a crosslinkable fluoroelastomer composite formed from the emulsion mixture has less than about 2000 ppb metal content.  
   
   
       21 . The emulsion mixture of  claim 16 , wherein a crosslinkable fluoroelastomer composite formed from the emulsion mixture has less than about 1000 ppb metal content.  
   
   
       22 . The emulsion mixture of  claim 16 , wherein a crosslinkable fluoroelastomer composite formed from the emulsion mixture has less than about 500 ppb metal content.  
   
   
       23 . The emulsion mixture of  claim 16 , wherein a crosslinkable fluoroelastomer composite formed from the emulsion mixture has less than about 200 ppb metal content.  
   
   
       24 . A crosslinkable composite comprising 
 i) a composition comprising a crosslinkable fluoroelastomer terpolymer consisting essentially of tetrafluoroethylene (TFE), perfluoromethyl vinyl ether (PMVE) and perfluorocyano vinyl ether (CNVE), and    ii) at least one additional material selected from fillers and additives,    wherein the crosslinkable composite has less than about 3000 ppb metal content, and    wherein the composite when crosslinked has a compression set of less than 50% when tested at 200° C.    
   
   
       25 . The composite of  claim 24  wherein the composition further comprises SiO 2 .  
   
   
       26 . The composite of  claim 24 , wherein the compression set is less than about 40%.  
   
   
       27 . The composite of  claim 24  wherein the compression set is less than about 30%.  
   
   
       28 . The composite of  claim 24  wherein the compression set is less than about 20%.  
   
   
       29 . The composite of  claim 24  wherein the at least one additional material is about 1 to 20 wt % of the composite.  
   
   
       30 . The composite of  claim 24  wherein the crosslinkable fluoroelastomer terpolymer comprises 8-CNVE.  
   
   
       31 . The composite of  claim 24  wherein the crosslinkable terpolymer has a metal content of less than about 2000 ppb.  
   
   
       32 . The composite of  claim 24  wherein the crosslinkable terpolymer has a metal content of less than about 1000 ppb.  
   
   
       33 . The composite of  claim 24  wherein the crosslinkable terpolymer has a metal content of less than about 500 ppb.  
   
   
       34 . The composite of  claim 24  wherein the crosslinkable terpolymer has a metal content of less than about 200 ppb.  
   
   
       35 . (canceled)  
   
   
       36 . The composite of  claim 24  wherein the composite has a metal content of less than about 2000 ppb.  
   
   
       37 . The composite of  claim 24  wherein the composite has a metal content of less than about 1000 ppb.  
   
   
       38 . The composite of  claim 24  wherein the composite has a metal content of less than about 500 ppb.  
   
   
       39 . The composite of  claim 24  wherein the crosslinkable terpolymer has a metal content of less than about 200 ppb.  
   
   
       40 . A crosslinkable composite comprising 
 i) a composition comprising a crosslinkable fluoroelastomer terpolymer consisting essentially of tetrafluoroethylene (TFE), perfluoromethyl vinyl ether (PMVE) and perfluorocyano vinyl ether (CNVE), and    ii) a composition comprising a functionalized polytetrafluoroethylene (PTFE) polymer comprising crosslinkable moieties having a particle size of 10 nm to 100 nm    wherein the crosslinkable composite has less than about 3000 ppb metal content, and further, wherein when the PTFE and the fluoroelastomer terpolymer are crosslinked to form a crosslinked composite, the crosslinked composite has a compression set of less than 50% when tested at 150° C.    
   
   
       41 . The composite of  claim 40  wherein the PTFE polymer is crosslinked with the crosslinkable fluoroelastomer terpolymer.  
   
   
       42 . The composite of  claim 40  wherein the crosslinkable moieties of the functionalized PTFE are perfluorocyano vinyl ether.  
   
   
       43 . The composite of  claim 40  wherein the crosslinkable moieties of the functionalized PTFE are 8-CNVE.  
   
   
       44 . The composite of  claim 40  wherein the crosslinkable fluoroelastomer terpolymer comprises 8-CNVE.  
   
   
       45 . The composite of  claim 40  wherein the composite further comprises at least one additional material selected from fillers and additives.  
   
   
       46 . The composite of  claim 40  wherein the composite further comprises SiO 2 .  
   
   
       47 . The composite of  claim 40  wherein the filler comprises about 1 to 20 wt % of the composite.  
   
   
       48 . (canceled)  
   
   
       49 . (canceled)  
   
   
       50 . (canceled)  
   
   
       51 . (canceled)  
   
   
       52 . (canceled)  
   
   
       53 . The composite of  claim 40  wherein the composite has a metal content of less than about 2000 ppb.  
   
   
       54 . The composite of  claim 40  wherein the composite has a metal content of less than about 1000 ppb.  
   
   
       55 . The composite of  claim 40  wherein the composite has a metal content of less than about 500 ppb.  
   
   
       56 . The composite of  claim 40  wherein the composite has a metal content of less than about 200 ppb.  
   
   
       57 . The emulsion mixture of  claim 1  wherein the fluoroelastomer composite has less than 2 ppm APFO.  
   
   
       58 . The composite of  claim 24  wherein the composite has an APFO concentration of less than 2 ppm.  
   
   
       59 . The composite of  claim 40  wherein the composite contains no more than 2.0 ppm APFO.