Catheter balloon

Abstract

To provide a catheter balloon which has a multilayer construction and in which excessive expansion beyond a proper expansion diameter of a balloon due to easier breaking of any layer easier than breaking of other layers, can be prevented.SOLUTION: A catheter balloon 200 has a first layer 310 and a second layer 320 arranged adjacently in a thickness direction of the balloon, the first and second layers are formed of different materials, and breaking strength of the first layer and breaking strength of the second layer are equal.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catheter balloon. [Background technology]

[0002] Balloon catheters are widely known as medical devices that dilate stenoses (lesions) formed in biological lumens such as blood vessels. The balloons of balloon catheters have been designed with various features to improve the therapeutic effect. For example, one of the properties required for a balloon is its pressure resistance (breakage resistance).

[0003] Generally, a balloon is manufactured by forming a cylindrical member (balloon material) made of a specific resin material into a desired shape by a molding method such as blow molding. Therefore, the performance derived from the physical properties of the balloon depends on the material of the balloon material used for the balloon. In view of this, for example, Patent Document 1 proposes a balloon catheter equipped with a balloon made of two layers with different physical properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2015-181772 Summary of the Invention [Problem to be solved by the invention]

[0005] The balloon catheter in Patent Document 1 aims to improve the shape recovery of the balloon after expansion by adopting a multi-layered balloon consisting of a shape memory layer with a predetermined glass transition temperature and a base layer with a higher strength (breaking strength) than the shape memory layer. However, the balloon catheter described in Patent Document 1 has the following problems.

[0006] In the multi-layered balloon used in Patent Document 1, the strength of the base layer is higher than that of the shape memory layer. Since each layer has a different strength, if the shape memory layer, which has a low strength, breaks (cracks), the balloon will be substantially composed of only the base layer. If the supply of fluid to the balloon continues in this state, high pressure will be applied only to the base layer, and the balloon may be over-expanded beyond the appropriate expansion diameter.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a catheter balloon that can prevent a balloon from being over-expanded beyond the appropriate expansion diameter due to one layer of a multi-layered balloon being more easily ruptured than the other layers. [Means for solving the problem]

[0008] The present invention can be achieved by any one of the following means (1) to (10).

[0009] (1) A catheter balloon having a first layer and a second layer arranged adjacent to each other in the thickness direction of the balloon, the first layer and the second layer being made of different materials, and the breaking strength of the first layer and the breaking strength of the second layer being the same.

[0010] (2) The catheter balloon described in (1) above, wherein the second layer is arranged to cover the first layer, and the elongation rate of the first layer is greater than the elongation rate of the second layer.

[0011] (3) The catheter balloon described in (2) above, wherein the hardness of the first layer is lower than the hardness of the second layer.

[0012] (4) The catheter balloon described in (2) or (3) above, wherein the tensile modulus of the first layer is smaller than the tensile modulus of the second layer.

[0013] (5) The catheter balloon according to any one of (1) to (4) above, wherein the first layer is any one of a polyamide elastomer, a polyurethane, and a polyurethane elastomer, and the second layer is a polyamide.

[0014] (6) The catheter balloon described in (1) above, further comprising a third layer adjacent to the second layer and arranged to cover the second layer, the breaking strength of the third layer being the same as the breaking strength of the first layer and the breaking strength of the second layer.

[0015] (7) The catheter balloon described in (6) above, wherein the elongation rate of the first layer and the elongation rate of the third layer are the same, and the elongation rate of the first layer and the elongation rate of the third layer are greater than the elongation rate of the second layer.

[0016] (8) The catheter balloon described in (7) above, wherein the hardness of the first layer and the hardness of the third layer are the same, and the hardness of the first layer and the hardness of the third layer are less than the hardness of the second layer.

[0017] (9) A catheter balloon as described in (7) or (8) above, wherein the tensile modulus of the first layer and the tensile modulus of the third layer are the same, and the tensile modulus of the first layer and the tensile modulus of the third layer are smaller than the tensile modulus of the second layer.

[0018] (10) The catheter balloon according to any one of (6) to (9) above, wherein the first layer is a polyamide elastomer, the second layer is a polyamide, and the third layer is a polyamide elastomer. Effect of the Invention

[0019] The catheter balloon of (1) above has a multi-layer structure consisting of a first layer and a second layer arranged adjacent to each other in the thickness direction of the balloon, and therefore the pressure resistance of the balloon can be effectively increased. In addition, since the breaking strength of the first layer and the breaking strength of the second layer of the catheter balloon are the same, it is possible to prevent the balloon from being over-expanded beyond the appropriate expansion diameter due to one layer breaking more easily than the other layer during a procedure. In addition, since the first layer and the second layer of the catheter balloon are made of different materials, the balloon can be provided with desired physical properties by selecting any different material for each layer. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing a balloon catheter according to an embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the tip of the balloon catheter. [Diagram 3] 3A is a cross-sectional view (axially orthogonal cross-sectional view) of a portion indicated by arrows 3A-3A in FIG. 2. [Figure 4] FIG. 11 is a cross-sectional view (cross-sectional view perpendicular to the axis) of a catheter balloon according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings (for example, the thicknesses of each layer of the balloon and the dimensional ratios of other members) are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0022] FIG. 1 is a diagram showing a balloon catheter 10 according to an embodiment, FIG. 2 is a partial cross-sectional view of the vicinity of the tip of the balloon catheter 10, and FIG. 3 is an orthogonal cross-sectional view taken along arrows 3A-3A shown in FIG.

[0023] In this embodiment, the catheter balloon according to the present invention will be described through a balloon catheter 10. Each part of the balloon catheter 10 may adopt any structure known in the medical field, and is not limited to the configuration described below. For example, the catheter balloon can be applied to a balloon of a catheter for stent delivery, etc.

[0024] <Balloon Catheter 10> As shown in FIG. 1, the balloon catheter 10 includes a shaft portion 100, a catheter balloon 200 that can expand and contract as a pressurized medium is injected and discharged, a distal tip 410, and a hub portion 420.

[0025] In this specification, the side of the balloon catheter 10 that is introduced into the living body (the side where the distal tip 410 is arranged) is referred to as the distal side, and the end portion of each member and component located on the distal side is referred to as the "distal portion." Additionally, the side of the balloon catheter 10 where the hub portion 420 is arranged is referred to as the proximal side, and the end portion of each member and component located on the proximal side is referred to as the "proximal portion." Additionally, the direction from the distal portion to the proximal portion (or from the proximal portion to the distal portion) is referred to as the "axial direction (longitudinal direction)." The above definitions of the distal side (distal portion), proximal side (proximal portion), and axial direction also apply to the positions and directions of each end portion of the catheter balloon 200.

[0026] The distal tip 410 is disposed for the purpose of preventing damage to a biological organ (such as the inner wall of a blood vessel) when the distal end of the balloon catheter 10 comes into contact with the biological organ.

[0027] 2, the distal tip 410 is disposed at the distal end of the shaft portion 100. Inside the distal tip 410, an inner cavity 415 is formed through which a guide wire (not shown) can be inserted.

[0028] The tip tip 410 can be made of, for example, a material that is more flexible than the shaft portion 100. The tip tip 410 can be made of, for example, a polymer material such as polyolefin (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture of these, or a multi-layer tube of two or more of the above polymer materials.

[0029] 1 and 2, the catheter balloon 200 is fixed near the tip of the shaft section 100. At the base end of the shaft section 100, a hub section 420 is arranged to which an indeflator can be connected for supplying various pressurized media to the catheter balloon 200 and discharging the pressurized media from the catheter balloon 200.

[0030] 2, the shaft portion 100 includes an outer shaft 110 and an inner shaft 120. The inner shaft 120 is inserted into the inner cavity 115 of the outer shaft 110.

[0031] The tip of the inner shaft 120 protrudes a predetermined length toward the tip side beyond the outer shaft 110. The catheter balloon 200 has a tip portion fixed to the tip portion of the inner shaft 120 and a base end portion fixed to the tip portion of the outer shaft 110.

[0032] The inner cavity 115 of the outer shaft 110 forms, between the inner shaft 120 and itself, an expansion lumen that communicates with the space 240 of the catheter balloon 200 .

[0033] As shown in Fig. 1, the base end of the inner shaft 120 forms a guidewire port 127 which serves as an entrance and exit for inserting a guidewire into the shaft portion 100. The inner cavity 125 of the inner shaft 120 forms a guidewire lumen through which a guidewire can be inserted. In other words, the balloon catheter 10 is configured as a so-called rapid exchange type catheter. The balloon catheter 10 may also be configured as a so-called over-the-wire type catheter.

[0034] A radiopaque marker 430 for indicating, for example, the axial center position of the straight portion 230 of the catheter balloon 200 can be disposed on the shaft portion 100. The radiopaque marker 430 can be made of, for example, a metal such as platinum, gold, silver, iridium, titanium, or tungsten, or an alloy thereof.

[0035] The outer shaft 110 and the inner shaft 120 can be formed from, for example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer; thermoplastic resins such as soft polyvinyl chloride; various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer; and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene.

[0036] <Catheter balloon 200> As shown in Fig. 2, the catheter balloon 200 has a distal tapered section 210 having a cross-sectional shape that is inclined toward the central axis of the shaft section 100 toward the distal end, a proximal tapered section 220 having a cross-sectional shape that is inclined toward the central axis of the shaft section 100 toward the proximal end, and a straight section 230 disposed between the distal tapered section 210 and the proximal tapered section 220. Note that, for the sake of simplicity in explaining the present invention, Fig. 2 shows the catheter balloon 200 in an expanded state.

[0037] The catheter balloon 200 is fixed to the shaft portion 100 so as to define a space 240 between the inner shaft 120 and the balloon 200 into which a pressurized medium (for example, a fluid such as physiological saline or a contrast agent) can be injected.

[0038] As shown in FIGS. 2 and 3, the catheter balloon 200 has a first layer 310 and a second layer 320 that are disposed adjacent to each other in the thickness direction of the balloon 200.

[0039] In this embodiment, the first layer 310 and the second layer 320 are made of different materials. Furthermore, the rupture strength of the first layer 310 and the rupture strength of the second layer 320 are the same.

[0040] The breaking strength of the first layer 310 and the breaking strength of the second layer 320 are, for example, 40 to 62 MPa. In this specification, the "breaking strength" is a value (tensile strength / breaking point) defined based on a tensile test specified by any one of ISO 527, ASTM D638, and JIS K 7311.

[0041] In addition, the above-mentioned "arranged adjacently in the thickness direction of the balloon 200" means that the first layer 310 and the second layer 320 are arranged adjacent to each other with the inner surface of the second layer 320 in contact (abutment) with the outer surface of the first layer 310.

[0042] 2 and 3, the second layer 320 is disposed so as to cover the first layer 310. In other words, the first layer 310 is an inner layer that constitutes the inner surface of the catheter balloon 200, and the second layer 320 is an outer layer that constitutes the outer surface of the catheter balloon 200.

[0043] For example, the extensibility of the first layer 310 can be configured to be greater than the extensibility of the second layer.

[0044] The elongation of the first layer 310 is, for example, 360 to 700%. The elongation of the second layer 320 is, for example, 50 to 360%. In this specification, the "elongation" is a value defined based on a tensile test specified by any one of ISO 527, ASTM D638, and JIS K 7311.

[0045] For example, the hardness of the first layer 310 can be configured to be less than the hardness of the second layer 320 .

[0046] The first layer 310 has a hardness of, for example, Shore D 62 to 78. The second layer 320 has a hardness of, for example, Shore D 52 to 70. In this specification, the "hardness" is a value defined based on a hardness test specified by any one of ISO 868, ASTM D785, and JIS K 7311.

[0047] For example, the tensile modulus of the first layer 310 can be configured to be less than the tensile modulus of the second layer.

[0048] The tensile modulus of the first layer 310 is, for example, 460 MPa. The tensile modulus of the second layer 320 is, for example, 1100 to 2700 MPa. In this specification, the "tensile modulus" is a value defined based on a tensile test specified by ISO 527 or ASTM D 638.

[0049] The first layer 310 may be composed of, for example, any one of a polyamide elastomer, a polyurethane, and a polyurethane elastomer.

[0050] The second layer 320 may be composed of, for example, polyamide.

[0051] The following are examples of suitable combinations of materials for the first layer 310 and the second layer 320. However, the materials used for the first layer 310 and the second layer 320 are not limited to only the examples below.

[0052] For example, a polyamide elastomer (manufactured by M-Chemie Japan, product name: ELG6260) having a breaking strength of 50 MPa (ISO 527), a tensile modulus of elasticity of 460 MPa (ISO 527), an elongation (at break) of 400% (ISO 527), and Shore D62 (ISO 868) can be suitably used for the first layer 310. When the above-mentioned material is used for the first layer 310, a polyamide (manufactured by M-Chemie Japan, product name: L25) having a breaking strength of 50 MPa (ISO 527), a tensile modulus of elasticity of 1100 MPa (ISO 527), an elongation (at break) of 360%>50% (ISO 527), and Shore D70 (ISO 868) can be suitably used for the second layer 320.

[0053] Also, for example, a polyamide elastomer (manufactured by ARKEMA, product name Pebax (registered trademark)) having a breaking strength of 62 MPa (ASTM D 638), an elongation (at break) of 360% (ASTM D 638), and Shore D72 (ISO 868) can be suitably used for the first layer 310. When the above-mentioned material is used for the first layer 310, a polyamide (manufactured by Mitsuboshi Belting, Nylon 6) having a breaking strength of 62 MPa (ISO 527), a tensile modulus of elasticity of 2700 MPa (ASTM D638), an elongation (at break) of 290% (ASTM D 638), and Shore D52 (ASTM D 785) can be suitably used for the second layer 320.

[0054] For example, a polyurethane elastomer (manufactured by BASF, product name: Elastone (registered trademark)) having a breaking strength of 40 MPa (JIS K 7311), an elongation (breaking point) of 700% (JIS K 7311), and Shore D72±3 (JIS K 7311) can be suitably used for the first layer 310. When the above-mentioned material is used for the first layer 310, a polyamide (manufactured by M-Chemie Japan, product name: L20LF) having a breaking strength of 50 MPa (ISO 527), a tensile modulus of elasticity of 1100 MPa (ISO 527), an elongation (breaking point) of 360%>50% (JIS K 7311), and Shore D52 (ISO 868) can be suitably used for the second layer 320.

[0055] The outer diameter φ1 of the catheter balloon 200 (outer diameter in an unexpanded state after molding) can be, for example, 3.0 to 7.0 mm.

[0056] The film thickness t1 of the first layer 310 can be set to, for example, 0.5 to 50.0 μm.

[0057] The film thickness t2 of the second layer 320 can be set to, for example, 0.5 to 50.0 μm.

[0058] The effects of this embodiment will be described below.

[0059] The catheter balloon 200 of this embodiment has a first layer 310 and a second layer 320 arranged adjacent to each other in the thickness direction of the balloon 200, and the first layer 310 and the second layer 320 are made of different materials, and the breaking strength of the first layer 310 and the breaking strength of the second layer 320 are the same.

[0060] The catheter balloon 200 configured as described above has a multi-layer structure consisting of the first layer 310 and the second layer 320 arranged adjacent to each other in the thickness direction of the balloon 200, and therefore the pressure resistance of the balloon 200 can be effectively improved. In addition, since the rupture strength of the first layer 310 and the rupture strength of the second layer 320 of the catheter balloon 200 are the same, it is possible to prevent the balloon 200 from being overexpanded beyond the appropriate expansion diameter due to one layer being more easily ruptured than the other layer during a procedure. In addition, since the catheter balloon 200 has the first layer 310 and the second layer 320 made of different materials, the balloon 200 can be provided with desired physical properties by selecting any different materials as the materials for the layers 310 and 320.

[0061] In addition, the second layer 320 is disposed so as to cover the first layer 310 , and the elongation rate of the first layer 310 can be configured to be greater than the elongation rate of the second layer 320 .

[0062] When fluid is supplied into the space 240, the catheter balloon 200 configured as described above starts to expand from the first layer 310 disposed inside the second layer 320. Since the elongation rate of the first layer 310 is greater than that of the second layer 320, the second layer 320 located on the outer surface side of the first layer 310 starts to expand to follow the expansion of the first layer 310 after the first layer 310 expands to a predetermined outer diameter. Therefore, when fluid is supplied into the space 240, the catheter balloon 200 expands in the order of the first layer 310 and the second layer 320, and can be smoothly expanded to a desired expansion diameter.

[0063] Additionally, the hardness of the first layer 310 can be configured to be less than the hardness of the second layer 320 .

[0064] In the catheter balloon 200 configured as described above, when the first layer 310 expands, the expansion diameter of the first layer 310 is controlled by the second layer 320 disposed on the outer surface side of the first layer 310. Therefore, the catheter balloon 200 can prevent overexpansion of the balloon 200 that would occur due to excessive expansion of the first layer 310, which has a larger elongation rate than the first layer 310.

[0065] Additionally, the tensile modulus of the first layer 310 may be configured to be less than the tensile modulus of the second layer 320 .

[0066] In the catheter balloon 200 configured as described above, the tensile modulus of the second layer 320 is greater than that of the first layer 310. Therefore, when a fluid flows into the space 240 and the same pressurized force is applied to the first layer 310 and the second layer 320, the second layer 320 is less likely to deform than the first layer 310. Therefore, the second layer 320 can prevent the catheter balloon 200 from being overexpanded. In addition, since the second layer 320 is less likely to deform than the first layer 310, the second layer 320 is less likely to stretch than the first layer 310 when the same pressurized force is applied. Therefore, the second layer 320 can also contribute to improving the pressure resistance of the catheter balloon 200.

[0067] Additionally, the first layer 310 may be made of any one of a polyamide elastomer, a polyurethane, and a polyurethane elastomer, and the second layer 320 may be made of a polyamide.

[0068] The catheter balloon 200 configured as described above can effectively increase the pressure resistance of the balloon 200 while making the breaking strength of the first layer 310 and the breaking strength of the second layer 320 the same.

[0069] Next, a modified example of the embodiment described above will be described. Explanations of the same configurations and members as those already described will be omitted as appropriate. Furthermore, contents that are not specifically described can be configured in the same way as the embodiment described above.

[0070] <Modification> FIG. 4 shows a cross-sectional view (cross-sectional view perpendicular to the axis corresponding to FIG. 3) of a catheter balloon 200A according to a modified example.

[0071] As shown in FIG. 4, the catheter balloon 200A has a third layer 330 disposed adjacent to the second layer 320 so as to cover the second layer 320.

[0072] The catheter balloon 200 has a multilayer structure consisting of three layers: a first layer 310, a second layer 320, and a third layer 330. The first layer 310 constitutes the inner layer (innermost layer) of the catheter balloon 200A, the second layer 320 arranged so as to cover the first layer 310 constitutes the middle layer of the catheter balloon 200A, and the third layer 330 arranged so as to cover the second layer 320 constitutes the outer layer (outermost layer) of the catheter balloon 200A.

[0073] The rupture strength of the third layer 330 is the same as the rupture strength of the first layer 310 and the rupture strength of the second layer 320 .

[0074] As described above, when the breaking strengths of the first layer 310 and the second layer 320 are 40 to 62 MPa, the breaking strength of the third layer 330 can be set to 40 to 62 MPa, similarly to these.

[0075] For example, the elongation rate of the first layer 310 and the elongation rate of the third layer 330 can be configured to be the same. For example, the elongation rate of the first layer 310 and the elongation rate of the third layer 330 can be configured to be greater than the elongation rate of the second layer 320.

[0076] As described above, when the elongation percentage of the first layer 310 is 360 to 700% and the elongation percentage of the second layer 320 is 50 to 360%, the elongation percentage of the third layer 330 can be 360 ​​to 700%, similar to that of the first layer 310.

[0077] For example, the hardness of the first layer 310 and the hardness of the third layer 330 can be configured to be the same. Also, the hardness of the first layer 310 and the hardness of the third layer 330 can be configured to be smaller than the hardness of the second layer 320.

[0078] As described above, when the hardness of the first layer 310 is Shore D62 to 78 and the hardness of the second layer 320 is Shore D52 to 70, the hardness of the third layer 330 can be Shore D62 to 78, similar to the hardness of the first layer 310.

[0079] For example, the tensile modulus of elasticity of the first layer 310 and the tensile modulus of elasticity of the third layer 330 can be configured to be the same. For example, the tensile modulus of elasticity of the first layer 310 and the tensile modulus of elasticity of the third layer 330 can be configured to be smaller than the tensile modulus of elasticity of the second layer 320.

[0080] As described above, when the tensile modulus of the first layer 310 is 460 MPa and the tensile modulus of the second layer 320 is 1100 to 2700 MPa, the tensile modulus of the third layer 330 can be set to 460 MPa, similar to that of the first layer 310.

[0081] The first layer 310 may be composed of, for example, a polyamide elastomer.

[0082] The second layer 320 may be composed of, for example, polyamide.

[0083] The third layer 330 may be composed of, for example, a polyamide elastomer.

[0084] The outer diameter φ2 of the catheter balloon 200A (outer diameter in an unexpanded state after molding) can be, for example, 4.0 to 8.0 mm.

[0085] The film thickness t1 of the first layer 310 can be set to, for example, 0.5 to 50.0 μm.

[0086] The film thickness t2 of the second layer 320 can be set to, for example, 0.5 to 50.0 μm.

[0087] The film thickness t3 of the third layer 330 can be set to, for example, 0.5 to 50.0 μm.

[0088] The effects of this modified example will be described below.

[0089] The catheter balloon 200A according to this modification has a third layer 330 disposed adjacent to the second layer 320 so as to cover the second layer 320. The breaking strength of the third layer 330 is the same as the breaking strength of the first layer 310 and the breaking strength of the second layer 320.

[0090] The catheter balloon 200A configured as described above has a multilayer structure consisting of three layers, the first layer 310, the second layer 320, and the third layer 330, and therefore can more effectively increase the pressure resistance of the balloon 200. In addition, since the first layer 310, the second layer 320, and the third layer 330 of the catheter balloon 200A have the same rupture strength, it is possible to prevent the balloon 200A from being over-expanded beyond the appropriate expansion diameter due to any layer rupturing more easily than the other layers during a procedure.

[0091] In addition, the elongation rate of the first layer 310 and the elongation rate of the third layer 330 can be configured to be the same, and the elongation rate of the first layer 310 and the elongation rate of the third layer 330 can be configured to be greater than the elongation rate of the second layer 320.

[0092] When a fluid is supplied into the space 240, the catheter balloon 200A configured as described above starts to expand from the first layer 310 arranged inside the second layer 320. Since the elongation rate of the first layer 310 is greater than that of the second layer 320, the second layer 320 located on the outer surface side of the first layer 310 starts to expand to follow the expansion of the first layer 310 after the first layer 310 expands to a predetermined outer diameter. Furthermore, since the elongation rate of the third layer 330 is greater than that of the second layer 320, the third layer 330 quickly expands to follow the expansion of the second layer 320 after the second layer 320 expands to a predetermined outer diameter. Therefore, the catheter balloon 200A can be smoothly expanded with the pressurizing force of the fluid flowing into the space 240.

[0093] In addition, the hardness of the first layer 310 and the hardness of the third layer 330 can be configured to be the same, and the hardness of the first layer 310 and the hardness of the third layer 330 can be configured to be smaller than the hardness of the second layer 320.

[0094] In the catheter balloon 200A configured as described above, when the first layer 310 expands, the expansion diameter of the first layer 310 is controlled by the second layer 320 arranged on the outer surface side of the first layer 310. Therefore, the catheter balloon 200 can prevent overexpansion of the balloon 200 caused by excessive expansion of the first layer 310, which has a higher elongation rate than the first layer 310. In addition, since the hardness of the second layer 320 is higher than the hardness of the third layer 330 arranged on the outer surface side of the second layer 320, the second layer 320 functions as a buffer layer that suppresses overexpansion of the catheter balloon 200A between the first layer 310 and the third layer 330. Therefore, the catheter balloon 200A can achieve both smooth expansion and prevention of overexpansion.

[0095] In addition, the tensile modulus of the first layer 310 and the tensile modulus of the third layer 330 can be configured to be the same, and the tensile modulus of the first layer 310 and the tensile modulus of the third layer 330 can be configured to be smaller than the tensile modulus of the second layer 320.

[0096] In the catheter balloon 200A configured as described above, the tensile modulus of the second layer 320 is greater than that of the first layer 310. Therefore, when a fluid flows into the space 240 and the same pressurized force is applied to the first layer 310 and the second layer 320, the second layer 320 is less likely to deform than the first layer 310. Therefore, the second layer 320 can prevent the catheter balloon 200 from being overexpanded. In addition, since the second layer 320 is less likely to deform than the first layer 310, the second layer 320 is less likely to stretch than the first layer 310 when the same pressurized force is applied. Therefore, the second layer 320 can also contribute to improving the pressure resistance of the catheter balloon 200A. In addition, since the tensile modulus of the third layer 330 is smaller than the tensile modulus of the second layer 320 disposed on the inner surface side of the third layer 330, when the second layer 320 expands, the third layer 330 can be rapidly expanded following the expansion of the second layer 320. Therefore, the catheter balloon 200A can realize improved pressure resistance, smooth expansion, and prevention of overexpansion.

[0097] Additionally, the first layer 310 can be comprised of a polyamide elastomer, the second layer 320 can be comprised of a polyamide, and the third layer 330 can be comprised of a polyamide elastomer.

[0098] The catheter balloon 200A configured as described above can effectively improve the pressure resistance of the balloon 200A while making the breaking strength of each of the layers 310, 320, 330 the same.

[0099] <Example> Next, examples of the present invention will be described. Note that the present invention is not limited to the contents described in the following examples.

[0100] In the examples, the following sample 1 (hereinafter referred to as the "catheter balloon of this example") and the following sample 2 (hereinafter referred to as the "catheter balloon of the comparative example") were prepared.

[0101] (Catheter balloon of this embodiment) It was configured with a three-layer structure consisting of a first layer 310, a second layer 320, and a third layer 330. The rupture strength of each of the layers 310, 320, and 330 was the same, being 50 MPa. The thickness of each of the layers 310, 320, and 330 was 37.6 μm, and the outer diameter Φ before expansion after blow molding was 5 mm.

[0102] (Catheter balloon of comparative example) It was configured with a three-layer structure consisting of a first layer 310, a second layer 320, and a third layer 330. The first layer 310 and the third layer 330 had a breaking strength of 18 MPa, and the second layer 320 had a breaking strength of 50 MPa. In other words, the first layer 310 and the third layer 330 had different breaking strengths from the second layer 320. The film thickness of each of the layers 310, 320, and 330 was 37.6 μm, and the outer diameter Φ before expansion after blow molding was 5 mm.

[0103] (Test Method) Five each of the "catheter balloon of this embodiment" and "catheter balloon of the comparative example" were prepared. A pressurizing device (fluid supply device) was connected to each catheter balloon, and the space was filled with liquid (water). The pressurizing device was operated to increase the pressure in the space by 1 atm at each time. At this time, the pressure was maintained for 60 seconds. The pressure was increased as described above, and the pressure at which each catheter balloon burst was recorded as the burst pressure.

[0104] From the above test, it was confirmed that the catheter balloon of this embodiment had a burst pressure of 29.2 atm (average value of five samples). On the other hand, it was confirmed that the catheter balloon of the comparative example had a burst pressure of 26.0 atm (average value of five samples). From this result, it was confirmed that the catheter balloon of this embodiment, in which the rupture strengths of the layers 310, 320, 330 are configured to be the same, has a higher pressure resistance than the catheter balloon of the comparative example.

[0105] The catheter balloon according to the present invention has been described above, but the present invention is not limited to the contents described in the specification and can be modified as appropriate based on the claims. [Explanation of symbols]

[0106] 10 Balloon Catheter 100 Shaft section 110 Outer shaft 120 Inner Shaft 200 Catheter balloon 210 Tip side tapered section 220 Base end taper 230 Straight section 240 Space section 310 First Layer 320 Second Layer 330 Third Layer

Claims

1. A catheter balloon, The balloon has a first layer and a second layer disposed adjacent to each other in a thickness direction of the balloon, the first layer and the second layer are made of different materials; A catheter balloon, wherein the first layer and the second layer have the same rupture strength.

2. the second layer is disposed so as to cover the first layer; The catheter balloon according to claim 1 , wherein the first layer has a greater elongation than the second layer.

3. The catheter balloon according to claim 2 , wherein the hardness of the first layer is less than the hardness of the second layer.

4. The catheter balloon according to claim 3 , wherein the first layer has a tensile modulus less than the second layer.

5. The first layer is any one of a polyamide elastomer, a polyurethane, and a polyurethane elastomer; The catheter balloon according to any one of claims 1 to 4, wherein the second layer is made of polyamide.

6. a third layer adjacent to the second layer and disposed so as to cover the second layer; The catheter balloon of claim 1 , wherein the rupture strength of the third layer is the same as the rupture strength of the first layer and the rupture strength of the second layer.

7. the elongation percentage of the first layer and the elongation percentage of the third layer are equal; The catheter balloon according to claim 6 , wherein the elongation rate of the first layer and the elongation rate of the third layer are greater than the elongation rate of the second layer.

8. the hardness of the first layer and the hardness of the third layer are the same; The catheter balloon according to claim 7 , wherein the hardness of the first layer and the hardness of the third layer are less than the hardness of the second layer.

9. the tensile modulus of the first layer and the tensile modulus of the third layer are the same; The catheter balloon according to claim 8 , wherein the tensile modulus of the first layer and the tensile modulus of the third layer are less than the tensile modulus of the second layer.

10. the first layer is a polyamide elastomer; the second layer is a polyamide; The catheter balloon according to any one of claims 6 to 9, wherein the third layer is a polyamide elastomer.

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