Block copolymer elastomer catheter balloons

• US 5,830,182 A
• Filed: 02/25/1997
• Issued: 11/03/1998
• Est. Priority Date: 03/02/1994
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Wang, Lixiao, Chen, Jianhua
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): SADULA, JENNIFER R
• Application Number:
  US08/805,899
• Time in Patent Office: 616 Days
• Field of Search: 604/96-103, 604/264, 604/280-2, 606/191-6
• US Class Current: 604/96.01
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 29/14 Materials characterised by their function or physical properties , e.g. lubricating compositions
• CPC Class Codes: B29L 2031/7542 Catheters
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 77/12 Polyester-amides

Abstract

Balloons for medical devices, particularly balloon angioplasty catheters, are made from particular block copolymer thermoplastic elastomers in which the block copolymer is made up of hard segments of a polyester or polyamide and soft segments of polyether; the polyester hard segments are polyesters of an aromatic dicarboxylic acid and a C₂ -C₄ diol; the polyamide hard segments are polyamides of C₆ or higher carboxylic acids and C₆ or higher organic diamines or of C₆ or higher aliphatic ω-amino-α-acids, and the polyether soft segments are polyethers of C₂ -C₁₀, diols; the block copolymer has a low flexural modulus, namely less than 150,000 psi; the block copolymer has a hardness, Shore D scale, of greater than 60; and the percentage by weight of the block polymer attributable to the hard segments is between about 50% and about 95%. The polymers provide high strength, thin wall, compliant and semi-compliant balloons, which leads to a low profile catheter. The low profile catheters have very good initial crossing, good trackability, good recrossing after first inflation.

Claims

1. A balloon for a medical device formed from a length of tubing of a polymer material by radial expansion of the tubing under pressure, the polymer material comprising a block copolymer thermoplastic elastomer characterized as follows:

the block copolymer comprises two or more hard segments of a polyester or polyamide and two or more soft segments of polyether;

the polyester hard segments are polyesters of an aromatic dicarboxylic acid and a C₂ -C₄ diol,

the polyamide hard segments are polyamides of C₆ or higher carboxylic acids and C₆ or higher organic diamines or of C₆ or higher aliphatic ω

-amino-α

-acids, and

the polyether soft segments are polyethers of C₂ -C₁₀ diols,

the block copolymer has a flexural modulus of less than about 150,000 psi;

the block copolymer has a hardness, Shore D scale, of greater than 60; and

the percentage by weight of the block polymer attributable to the hard segments is between about 50% and about 95%.

2. A balloon as in claim 1 wherein the block copolymer has a Shore D hardness in the range of 65-75 and a flexural modulus in the range of 50,000-120,000 psi.

3. A balloon as in claim 1 wherein the hard segments of the block copolymer are polyamide segments.

4. A balloon as in claim 1 wherein said polyether segment, is selected from the group consisting of poly(tetramethylene ether), poly(pentaniethylene ether) and poly(hexamethylene ether).

5. A balloon as in claim 1 wherein the wall strength of the balloon is at least 15,000 psi.

6. A balloon as in claim 5 wherein the wall thickness, single wall basis, is no more than 0.0015 inches and said wall strength is greater than 18,000 psi.

7. A balloon as in claim 6 wherein said wall thickness is no more than 0.0009 inches.

8. A balloon as in claim 5 wherein said wall strength is greater than 20,000 psi.

9. A balloon as in claim 1 having a compliant to semi-compliant distension profile whereby as inflation pressure is increased from 6 atm to 12 atm, the balloon expands from a nominal diameter at the 6 atm pressure to an increased diameter at the 12 atm pressure which is at least 7% greater than said nominal diameter.

10. A balloon as in claim 9 wherein the increased diameter at 12 atm is at least 10% greater than said nominal diameter.

11. A balloon as in claim 9 wherein the increased diameter is at least 16% greater than said nominal diameter.

12. A balloon as in claim 9 having a nominal diameter of between 1.5 mm and 10.0 mm, the balloon having a burst pressure of at least 10 atm.

13. A balloon as in claim 1 having a nominal diameter of between 1.5 mm and 4.0 mm, the balloon having a burst pressure of at least 12 atm.

14. A balloon as in claim 1 wherein the hard segments of the block copolymer are polyester segments.

15. A balloon as in claim 14 wherein said polyester segments are polyesters of an acid selected from the group consisting of ortho-, meta- or para- phthalic acid, napthalenedicarboxylic acid and meta-terphenyl-4,4'"'"'-dicarboxylic acids and a diol selected from the group consisting of ethylene glycol, 1,3-propane diol and 1,4-butane diol.

16. A balloon as in claim 1 wherein the block copolymer is poly(butylene terephthalate-block-poly(tetramethylene oxide).

17. A balloon as in claim 1 wherein the block copolymer is further characterized by a ultimate tensile strength of at least 6,000 psi and an ultimate elongation of at least 300%.

18. A dilation catheter having a elongated tubular body, a balloon mounted on a distal end thereof and means for inflation of the balloon, wherein the balloon is a balloon as in claim 1.

19. A balloon as in claim 1 wherein the tubing polymer material consists of a single polymer.