Medical balloon

Abstract

A medical balloon for a balloon catheter is described. The balloon has at least a first layer made from a first material and a second layer made from a second material, said first and second layers being in overlying relationship with one another and being integral with one another; wherein the first layer has a softening or melting temperature which is higher than a softening or melting temperature of the second layer. A method of forming the medical balloon is also described, including locating a raw tubing in a mold; preheating and inflating the raw tubing so as to cause it to stretch; heating the raw tubing to soften or melt the second layer; setting the inflated raw tubing to form the medical balloon; and cooling the set balloon.

We claim: 
     
         1 . A medical balloon comprising:
 an inner layer comprising a first expandable material having a first softening or melting temperature;   an outer layer comprising a second expandable material having a second softening or melting temperature that is lower than the first softening or melting temperature;
 wherein the inner and outer layers are disposed in an overlying and integral or otherwise bonded relationship with one another; and 
   a woven material that is at least partially embedded in the outer layer;
 wherein the inner layer has a heat-set temperature higher than a heat-set temperature of the outer layer, and the inner layer is free of the woven material. 
   
     
     
         2 . The medical balloon of  claim 1 , where the outer layer comprises material selected from a group consisting of a polyolefin resin, a polyurethane resin, an anhydride-modified ethylene elastomer-based adhesive resin, an anhydride-modified linear low-density polyethylene, a polyolefin modified with hydroxyl groups, and a polyolefin modified with anhydride groups. 
     
     
         3 . The medical balloon of  claim 1 , where the outer layer comprises a functionalized polyolefin. 
     
     
         4 . The medical balloon of  claim 1 , where the inner layer comprises a material selected from a polyamide, a polyether block amide, a polyurethane, a polyethylene, polyethylene terephthalate (PET), and silicone. 
     
     
         5 . The medical balloon of  claim 1 , where the first layer comprises nylon. 
     
     
         6 . The medical balloon of  claim 1 , where the woven material is fully embedded within the outer layer. 
     
     
         7 . A medical balloon comprising:
 an inner layer comprising a first expandable material having a first softening or melting temperature;   an outer layer comprising a second expandable material
 including a functionalized polymer, and 
 having a second softening or melting temperature that is lower than the first softening or melting temperature; 
 wherein the inner and outer layers are disposed in an overlying and integral or otherwise bonded relationship with one another; and 
   a woven material or braided mesh that is at least partially embedded in the outer layer;   wherein the inner layer has a heat-set temperature higher than a heat-set temperature of the outer layer, and the inner layer is free of the woven material or braided mesh.   
     
     
         8 . The medical balloon of  claim 7 , where the functionalized polymer comprises a functionalized polyolefin, and the first expandable material comprises nylon. 
     
     
         9 . The medical balloon of  claim 7 , where the outer layer comprises material selected from a group consisting of polyolefin resin, polyurethane resin, anhydride-modified ethylene elastomer-based adhesive resin, anhydride-modified linear low-density polyethylene, a polyolefin modified with hydroxyl groups, a polyolefin modified with anhydride groups. 
     
     
         10 . The medical balloon of  claim 7 , where the second melting temperature is in a range selected from 115° C. to 140° C., 115° C. to 125° C., below 100° C., below 120° C., and below 140° C. 
     
     
         11 . The medical balloon of  claim 7 , where a thickness of the outer layer is in a range selected from no more than 20% of a thickness of the inner layer and no more than 40% of a thickness of the inner layer. 
     
     
         12 . The medical balloon of  claim 7 , where the first melting temperature is in a range from 165° C. to 205° C. 
     
     
         13 . The medical balloon of  claim 7 , where the heat-set temperature of the outer layer is no more than about 80% of the heat-set temperature of the inner layer. 
     
     
         14 . The medical balloon of  claim 7 , where the heat-set temperature of the outer layer is at least 20° C. less than the heat-set temperature of the inner layer, or is at least 10° C. less than the heat-set temperature of the inner layer. 
     
     
         15 . The medical balloon of  claim 7 , where the inner layer comprises a material selected from a polyamide, a polyether block amide, a polyurethane, a polyethylene, polyethylene terephthalate (PET), and silicone.