Blends of fluoroeleastomer interpolymers with thermo fluoroplastic interpolymers and the use of such blends in hoses

Abstract

A compostion having improved fuel vapor barrier properties comprising a blend of about 20 to 80 weight percent of a first fluorointerpolymer with about 80 to 20 weight percent of a second fluorointerpolymer, the first fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrafluoroethylene, and the second fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrafluorotheylene, wherein the first fluorointerpolymer exhibits elastomer characteristics and the second fluorointerpolymer exhibits thermoplstic characteristics.

What is claimed is:  
     
         1 . A composition having improved fuel vapor barrier properties comprising a blend of about 20 to 80 weight percent of a first fluorointerpolymer with about 80 to 20 weight percent of a second fluorointerpolymer, said first fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrafluoroethylene, and said second fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrafluorotheylene, wherein said first fluorointerpolymer exhibits elastomer characteristics and said second fluorointerpolymer exhibits thermoplastic characteristics.  
     
     
         2 . The composition of  claim 1  wherein said first fluorointerpolymer has a fluorine content of about 65 to 73 weight percent and said second fluorointerpolymer has a fluorine content of about 70 to 75 weight percent.  
     
     
         3 . The composition of  claim 2  wherein said first fluorointerpolymer is a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer having elastomeric characteristics and said second fluorointerpolymer in a hexafluoropropylene-tetrafluoroethylene-vinylidene fluoride terpolymer having thermoplastic characteristics.  
     
     
         4 . The composition of  claim 1  further comprising a conductive material.  
     
     
         5 . The composition of  claim 4  wherein said conductive agent is carbon black.  
     
     
         6 . A fuel hose having improved fuel vapor barrier properties comprising: 
 a barrier layer comprising a blend of about 20 to 80 weight percent of a first fluorointerpolymer with about 80 to 20 weight percent of a second fluorointerpolymer, said first fluorointerpolymer comprising a copolymer, terpolymer or a mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride, and tetrafluoroethylene, and said second fluorointerpolymer comprises a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrofluororethylene; and    a protective cover layer.    
     
     
         7 . The hose of  claim 6  further comprising a reinforcing layer.  
     
     
         8 . The hose of  claim 7  further comprising one or more elastomeric layers.  
     
     
         9 . The hose of  claim 8  wherein one of said one or more elastomeric layers resides between said barrier layer and said reinforcing layer, and said reinforcing layer resides between said elastomeric layer and said protective cover layer.  
     
     
         10 . The hose of  claim 6  wherein said barrier layer is about 5 to 25 mils thick.  
     
     
         11 . The hose of  claim 7  wherein said reinforcing layer is a layer of fibers selected from the group consisting of polyamide fibers, polyester fibers, rayon fibers, glass fibers and cotton fibers.  
     
     
         12 . The hose of  claim 13  wherein said fibers are aromatic polyamide fibers.  
     
     
         13 . The hose of  claim 12  wherein said fibers are knitted, braided or spiraled in the construction of said hose.  
     
     
         14 . The hose of  claim 6  wherein said protective cover layer is a layer of synthetic elastomer selected from the group consisting of styrene-butadiene rubber, nitrile-butadiene rubber, chloroprene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, epichlorohydrin ethylene oxide, polyvinyl chloride, and blends thereof.  
     
     
         15 . The hose of  claim 14  wherein said protective cover is chlorinated polyethylene.  
     
     
         16 . The hose of  claim 8  wherein barrier layer or one of said one or more elastomeric layers forms an inner tubular layer of said hose.  
     
     
         17 . The hose of  claim 16  wherein said inner tubular layer further comprises a conductive material.  
     
     
         18 . The hose of  claim 17  wherein said conductive material is carbon black.  
     
     
         19 . The hose of  claim 9  wherein said elastomeric layer is acrylonitrile-butadiene rubber  
     
     
         20 . In a hose for transporting fuels, the improvement which comprises employing, as a barrier layer, a blend of about 20 to 80 weight percent of a first fluorointerpolymer with about 80 to 20 weight percent of a second fluorointerpolymer, said first fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene vinylidene fluoride, and tetrafluoroethylene, and a second fluorointerpolymer comprising a copolymer, terpolymer or mixture thereof formed by the copolymerization of two or more monomers selected from the group consisting of hexafluoropropylene, vinylidene fluoride and tetrofluorethylene, wherein said first fluorointerpolymer exhibits elastomer characteristics and said second fluorointerpolymer exhibits thermoplastic characteristics.