Semi-compliant catheter balloons and methods of manufacture thereof

Abstract

The present invention relates to catheter balloons for medical devices. In particular, the present invention provides biaxially oriented semi-compliant catheter balloons comprising acrylonitrile polymers, acrylonitrile copolymers, and acrylonitrile blends, and methods of making same. The catheter balloons provided herein exhibit relatively high tensile strength, controlled compliance, reduced tendency for pinholing, ease of coating with and of bonding to other compounds, as well as resistance to moisture.

1 . A catheter balloon comprising biaxially oriented acrylonitrile polymer.  
     
     
         2 . The catheter balloon of  claim 1 , wherein said balloon is within its glass transition state at approximately human body temperature.  
     
     
         3 . The catheter balloon of  claim 1 , wherein said acrylonitrile polymer catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         4 . The catheter balloon of  claim 3 , wherein the tailored compliance of said acrylonitrile polymer catheter balloon is from approximately 5% to approximately 15%.  
     
     
         5 . The catheter balloon of  claim 1 , wherein said acrylonitrile polymer catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0015 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         6 . A catheter balloon comprising biaxially oriented acrylonitrile copolymer.  
     
     
         7 . The catheter balloon of  claim 6 , wherein said acrylonitrile copolymer comprises acrylonitrile and methyl acrylate.  
     
     
         8 . The catheter balloon of  claim 7 , wherein said acrylonitrile copolymer comprises from approximately 73 to approximately 77 parts by weight of acrylonitrile and from approximately 23 to approximately 27 parts by weight of methyl acrylate, said acrylonitrile copolymer being BAREX 210™.  
     
     
         9 . The catheter balloon of  claim 8 , wherein said BAREX 210™ balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0012 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         10 . The catheter balloon of  claim 9 , wherein the tailored compliance of said acrylonitrile copolymer catheter balloon is from approximately 5% to approximately 15%.  
     
     
         11 . The catheter balloon of  claim 10 , wherein the intrinsic viscosity of said acrylonitrile copolymer catheter balloon is from approximately 0.8 to approximately 1.3.  
     
     
         12 . The catheter balloon of  claim 7 , wherein said acrylonitrile and methyl acrylate copolymer catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0012 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         13 . The catheter balloon of  claim 6 , wherein said acrylonitrile copolymer comprises from approximately 73 to approximately 77 parts by weight of acrylonitrile and from approximately 23 to approximately 27 parts by weight of methyl acrylate, said acrylonitrile copolymer being BAREX 218™.  
     
     
         14 . The catheter balloon of  claim 13 , wherein said BAREX 218™ catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         15 . The catheter balloon of  claim 14 , wherein the tailored compliance of said acrylonitrile copolymer catheter balloon is from approximately 5% to approximately 15%.  
     
     
         16 . The catheter balloon of  claim 15 , wherein the intrinsic viscosity of said acrylonitrile copolymer catheter balloon is from approximately 0.8 to approximately 1.3.  
     
     
         17 . The catheter balloon of  claim 13 , wherein said BAREX 218™ catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         18 . A catheter balloon comprising biaxially oriented acrylonitrile blend.  
     
     
         19 . The catheter balloon of  claim 18 , wherein said acrylonitrile blend comprises acrylonitrile and polyethylene elastomer.  
     
     
         20 . The catheter balloon of  claim 19 , wherein said acrylonitrile blend comprises approximately 70 parts by weight of acrylonitrile and approximately 30 parts by weight of polyethylene elastomer.  
     
     
         21 . The catheter balloon of  claim 20 , wherein said polyethylene elastomer catheter balloon has a mean wall thickness of from approximately 0.00065 inches to approximately 0.0015 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         22 . The catheter balloon of  claim 21 , wherein the tailored compliance of said acrylonitrile blend catheter balloon is from approximately 5% to approximately 15%.  
     
     
         23 . The catheter balloon of  claim 22 , wherein the intrinsic viscosity of said acrylonitrile blend catheter balloon is from approximately 0.8 to approximately 1.3.  
     
     
         24 . The catheter balloon of  claim 19 , wherein said acrylonitrile and polyethylene elastomer blend catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0012 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         25 . The catheter balloon of  claim 18 , wherein said acrylonitrile blend comprises acrylonitrile and a block copolymer comprising crystalline polybutylene terephthalate and amorphous long chain glycols, said block copolymer is HYTREL™.  
     
     
         26 . The catheter balloon of  claim 25 , wherein said acrylonitrile blend comprises approximately 70 parts by weight of acrylonitrile and approximately 30 parts by weight of HYTREL™.  
     
     
         27 . The catheter balloon of  claim 26 , wherein said acrylonitrile and HYTREL™ blend catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         28 . The catheter balloon of  claim 27 , wherein the tailored compliance of said acrylonitrile blend catheter balloon is from approximately 5% to approximately 15%.  
     
     
         29 . The catheter balloon of  claim 28 , wherein the intrinsic viscosity of said acrylonitrile blend catheter balloon is from approximately 0.8 to approximately 1.3.  
     
     
         30 . The catheter balloon of  claim 26 , wherein said acrylonitrile and HYTREL™ blend catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         31 . The catheter balloon of  claim 18 , wherein said acrylonitrile blend comprises acrylonitrile and polyether block amide.  
     
     
         32 . The catheter balloon of  claim 31 , wherein said acrylonitrile blend comprises approximately 60 parts by weight of acrylonitrile and approximately 40 parts by weight of polyether block amide.  
     
     
         33 . The catheter balloon of  claim 32 , wherein said acrylonitrile and polyether block amide blend catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches and a tensile strength of at least approximately 15000 psi.  
     
     
         34 . The catheter balloon of  claim 33 , wherein the tailored compliance of said acrylonitrile blend catheter balloon is from approximately 5% to approximately 15%.  
     
     
         35 . The catheter balloon of  claim 34 , wherein the intrinsic viscosity of said acrylonitrile blend catheter balloon is from approximately 0.8 to and approximately 1.3.  
     
     
         36 . The catheter balloon of  claim 32 , wherein said acrylonitrile and polyether bloc amide blend catheter balloon has a mean wall thickness of from approximately 0.0006 inches to approximately 0.0013 inches, reaches approximately quarter size at a pressure from approximately 12 atmospheres to approximately 14 atmospheres, reaches nominal size at a pressure of from approximately 4 atmospheres to approximately 6 atmospheres, and has a rated burst pressure of at least approximately 1 atmosphere greater than said pressure from approximately 12 atmospheres to approximately 14 atmospheres.  
     
     
         37 . A method for making a biaxially oriented catheter balloon, comprising: 
 a) providing a material selected from the group consisting of acrylonitrile, acrylonitrile copolymer, and acrylonitrile blend;    b) extruding said material to form an extruded tube;    c) heat setting said extruded tube to form a heat set tube;    d) longitudinally drawing said heat set tube to form a drawn tube;    e) radially expanding said drawn tube to form a balloon member; and    f) heat setting said balloon member to form a heat set balloon member.    
     
     
         38 . The method of  claim 37 , wherein said extruding is performed in a die comprising a barrel zone, and wherein said die is at a temperature of from approximately 500° F. to approximately 560° F. and said barrel zone is at a temperature of from approximately 400° F. to approximately 470° F.  
     
     
         39 . The method of  claim 38 , further comprising after step b) quenching said extruded tube in a water bath at approximately 22° C.  
     
     
         40 . The method of  claim 39 , wherein the distance between said water bath and said die is from approximately 0.2 inches to approximately 1.0 inches.  
     
     
         41 . The method of  claim 37 , wherein said tube is extruded at a drawdown ratio of less than 3:1.  
     
     
         42 . The method of  claim 41 , wherein said drawdown ratio is approximately 2:1.  
     
     
         43 . The method of  claim 37 , wherein said heat setting is at a temperature of from approximately 60° C. to approximately 80° C.  
     
     
         44 . The method of  claim 37 , wherein said heat setting is for a period of at least approximately two hours.  
     
     
         45 . The method of  claim 37 , wherein the time between said heat setting and said extruding is less than approximately eight hours.  
     
     
         46 . The method of  claim 37 , wherein said drawing is at a tube draw temperature between the first order glass transition temperature and the second order glass transition temperature of said material.  
     
     
         47 . The method of  claim 46 , wherein said tube draw temperature is from approximately 300° C. to approximately 450° C.  
     
     
         48 . The method of  claim 46 , wherein the length of said drawn tube is from approximately 2 times to approximately 5 times the length of said extruded tube.  
     
     
         49 . The method of  claim 37 , wherein said radially expanding is at a blow up ratio of from approximately 5.25:1 to approximately 7.25:1.  
     
     
         50 . The method of  claim 37 , wherein the ratio of mean wall thickness of said heat set tube to said heat set balloon is from approximately 15:1 to approximately 20:1.  
     
     
         51 . The method of  claim 37 , wherein said heat setting of said balloon member comprises raising the temperature of said balloon member to a heat setting temperature greater than the glass transition temperature of said material to form a heated balloon member, followed by cooling said heated balloon member to a temperature below the glass transition temperature of said material.  
     
     
         52 . The method of claim  51 , wherein said heat setting temperature is from approximately 90° C. to approximately 180° C.  
     
     
         53 . The method of claim  51 , wherein said glass transition temperature is from approximately 180° C. to approximately 240° C.  
     
     
         54 . The method of claim  51 , wherein said temperature below the glass transition temperature is from approximately 20° C. to approximately 25° C.