Catheter having a coextruded fluoropolymer layer

Abstract

A catheter shaft including an elongate tubular member including a first polymeric layer and a second polymeric layer bonded to the first polymeric layer. The first polymeric layer is formed of a polymer generally not bondable to fluoropolymers, and the second polymeric layer is formed of a fluoropolymer bonded to the polymer of the first polymeric layer. The fluoropolymer of the second polymeric layer is a functionalized polyvinylidene fluoride which has a bonding affinity to the polymer of the first polymeric layer. The functionalized polyvinylidene fluoride includes reactive functional groups chemically bonded to a polymer chain of a polyvinylidene fluoride which readily bond to the polymer chain of the polymer of the first polymeric layer.

1 . A method of forming a catheter shaft, the method comprising:
 disposing a first polymer in a molten state onto a mandrel, forming a first molten layer of the first polymer;   disposing a second polymer in a molten state over the first molten layer of the first polymer, forming a second molten layer of the second polymer over the first molten layer of the first polymer; and   allowing the first molten layer of the first polymer and the second molten layer of the second polymer to cool;   wherein one of the first polymer and the second polymer is a functionalized polyvinylidene fluoride, while the other of the first polymer and the second polymer is a polymer generally not compatible with polyvinylidene fluoride.   
     
     
         2 . The method of  claim 1 , further comprising passing the first molten layer of the first polymer and the second molten layer of the second polymer through an extrusion die while the first molten layer and the second molten layer remain in their molten state. 
     
     
         3 . The method of  claim 1 , wherein a bilayer polymer tube is formed having an inner layer formed of the first polymer bonded to an outer layer formed of the second polymer without any intervening layer positioned between the inner layer and the outer layer of the bilayer polymeric tube. 
     
     
         4 . The method of  claim 1 , wherein the functionalized polyvinylidene fluoride includes reactive functional groups chemically bonded to a polymer chain of a polyvinylidene fluoride. 
     
     
         5 . The method of  claim 4 , wherein the first polymer is a functionalized polyvinylidene fluoride, and wherein the functionalized polyvinylidene fluoride is covalently bonded to the second polymer. 
     
     
         6 . The method of  claim 5 , wherein the second polymer is one of the group of polyamide, polyether block amide, polyurethane, polyethylene and polyether. 
     
     
         7 . The method of  claim 4 , wherein the second polymer is a functionalized polyvinylidene fluoride, and wherein the functionalized polyvinylidene fluoride is covalently bonded to the first polymer. 
     
     
         8 . The method of  claim 7 , wherein the first polymer is one of the group of polyamide, polyether block amide, polyurethane, polyethylene and polyether. 
     
     
         9 . A method of forming a catheter shaft, the method comprising:
 extruding a first polymer in a molten state onto a mandrel, forming a first molten layer of the first polymer;   extruding a second polymer in a molten state over the first molten layer of the first polymer, forming a second molten layer of the second polymer over the first molten layer of the first polymer;   passing the first molten layer of the first polymer and the second molten layer of the second polymer through an extrusion die while the first molten layer and the second molten layer remain in their molten state; and   allowing the first molten layer of the first polymer and the second molten layer of the second polymer to cool;   wherein one of the first polymer and the second polymer is a functionalized polyvinylidene fluoride.   
     
     
         10 . The method of  claim 9 , wherein a bilayer polymer tube is formed having an inner layer formed of the first polymer bonded to an outer layer formed of the second polymer without any intervening layer positioned between the inner layer and the outer layer of the bilayer polymeric tube. 
     
     
         11 . The method of  claim 9 , wherein one of the first polymer and the second polymer is a polymer generally not compatible with polyvinylidene fluoride. 
     
     
         12 . The method of  claim 9 , wherein the functionalized polyvinylidene fluoride includes reactive functional groups chemically bonded to a polymer chain of a polyvinylidene fluoride. 
     
     
         13 . The method of  claim 12 , wherein the first polymer is a functionalized polyvinylidene fluoride, and wherein the functionalized polyvinylidene fluoride is covalently bonded to the second polymer. 
     
     
         14 . The method of  claim 10 , wherein the second polymer is one of the group of polyamide, polyether block amide, polyurethane, polyethylene and polyether. 
     
     
         15 . The method of  claim 12 , wherein the reactive functional groups include maleic anhydride. 
     
     
         16 . The catheter shaft of  claim 9 , wherein the functionalized polyvinylidene fluoride includes radiation-grafted reactive functional groups. 
     
     
         17 . The catheter shaft of  claim 16 , wherein the radiation-grafted reactive functional groups include a compound including a carboxylic acid or a derivative of a carboxylic acid. 
     
     
         18 . The method of  claim 12 , wherein the second polymer is a functionalized polyvinylidene fluoride, and wherein the functionalized polyvinylidene fluoride is covalently bonded to the first polymer. 
     
     
         19 . The method of  claim 18 , wherein the first polymer is one of the group of polyamide, polyether block amide, polyurethane, polyethylene and polyether. 
     
     
         20 . A method of forming a catheter shaft, the method comprising:
 extruding a first polymer in a molten state onto a mandrel, forming a first molten layer of the first polymer;   extruding a second polymer in a molten state over the first molten layer of the first polymer, forming a second molten layer of the second polymer over the first molten layer of the first polymer;   passing the first molten layer of the first polymer and the second molten layer of the second polymer through an extrusion die while the first molten layer and the second molten layer remain in their molten state; and   allowing the first molten layer of the first polymer and the second molten layer of the second polymer to cool, wherein one of the first polymer and the second polymer is a functionalized polyvinylidene fluoride, wherein a bilayer polymer tube is formed having an inner layer formed of the first polymer bonded to an outer layer formed of the second polymer without any intervening layer positioned between the inner layer and the outer layer of the bilayer polymeric tube;   wherein one of the first polymer and the second polymer is a functionalized polyvinylidene fluoride including reactive functional groups chemically bonded to a polymer chain of a polyvinylidene fluoride, while the other of the first polymer and the second polymer is a polymer generally not compatible with polyvinylidene fluoride.