Catheter balloon formed of ePTFE and a diene polymer

Abstract

A catheter balloon formed of a polymeric material such as expanded polytetrafluoroethylene (ePTFE) bonded to a second layer formed of a low tensile set polymer and/or impregnated with a low tensile set polymer. In a presently preferred embodiment, the low tensile set polymer is an elastomer selected from the group consisting of a silicone-polyurethane copolymer and a diene polymer. The low tensile set polymer has high strength, low modulus, high elongation, and low tensile set, to provide improved balloon performance. The diene or silicone-polyurethane has a low tensile set, which facilitates deflation of the balloon to a low profile deflated configuration. One aspect of the invention provides improved attachment of the diene to the ePTFE. In one embodiment, the second layer is formed of a diene mixed with a bonding promoter such as a vulcanizing agent which is covalently bonded to the diene.

1 - 45 . (canceled)  
     
     
         46 . A method of making a balloon for a catheter, comprising: 
 a) providing a first layer formed of expanded polytetrafluoroethylene coated or impregnated with a bondable material against a second layer formed of a mixture of a diene polymer and a bonding promoter which covalently bonds to the diene polymer and bonds to the bondable material of the first layer;    b) positioning the layers together; and    c) heat fusion bonding the layers together by heating the layers.    
     
     
         47 . The method of  claim 46  wherein the bonding promoter is a vulcanizing agent and (c) comprises heating the layers to vulcanize the diene of the second layer and hydrogen-bond the bondable material of the first layer to a functionality of the bonding promoter vulcanized with the diene.  
     
     
         48 . The method of  claim 47  wherein the second layer is heated prior to (b) to vulcanize the diene of the second layer, so that (c) comprises heating the layers to cause the bondable material of the first layer to hydrogen-bond to a functionality of the bonding promoter covalently bonded to the vulcanized diene.  
     
     
         49 . A method of making a balloon for a catheter, comprising: 
 a) providing a first layer formed of expanded polytetrafluoroethylene; and    b) exposing the first layer to a solution of a low tensile set polymer selected from the group consisting of a silicone-polyurethane copolymer and a diene polymer, so that the low tensile set polymer impregnates the expanded polytetrafluoroethylene.    
     
     
         50 . The method of  claim 49  wherein the expanded polytetrafluoroethylene layer is a tube and (b) comprises reversibly closing one end of the expanded polytetrafluoroethylene tube and injecting the low tensile set polymer solution into a lumen of the expanded polytetrafluoroethylene tube, and evaporating solvent from the injected low tensile set polymer solution, so that the low tensile set polymer impregnates the expanded polytetrafluoroethylene and coats an inner surface of the expanded polytetrafluoroethylene tube.  
     
     
         51 . The method of  claim 49  wherein the expanded polytetrafluoroethylene layer is a tube and (b) comprises inserting the expanded polytetrafluoroethylene tube inside a container with the low tensile set polymer solution in the container, and applying a vacuum to a lumen of the expanded polytetrafluoroethylene tube to introduce the low tensile set polymer solution into the expanded polytetrafluoroethylene lumen, and evaporating solvent from the introduced low tensile set polymer solution, so that the low tensile set polymer impregnates the expanded polytetrafluoroethylene and coats an inner surface of the expanded polytetrafluoroethylene tube