Masking member and formation method of coat layer

Abstract

To provide a masking member capable of suppressing excessive influence of an electron beam on a masked non-coat region of a balloon due to electron beam irradiation, and a formation method of a coat layer using the masking member.SOLUTION: A masking member 100 is used for masking a predetermined position of a balloon 20 when a coating agent 210 to be cured by electron beam is applied. The masking member includes an inner cavity 115 continuously extending with a predetermined length along an extension direction of the balloon and has a thickness of equal to or greater than 50 μm.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a masking member and a method for forming a coating layer. [Background technology]

[0002] In order to allow the balloon catheter to move smoothly within the patient's body, a coating agent (e.g., a coating liquid containing a hydrophilic polymer that forms a lubricating coating layer) may be applied to the surface of the balloon catheter, forming a coating layer on the surface of the balloon catheter.

[0003] There are various methods for curing the coating applied to a balloon catheter, but one method that uses electron beam irradiation is one that can shorten the time required to cure the coating.

[0004] The coating layer formed on a balloon catheter is required to exhibit excellent durability and coating performance in order to improve the balloon's reach and passability to the lesion. However, for example, in products with a relatively short balloon length, if the balloon slips during dilation of a lesion such as a stenosis, it becomes difficult to effectively dilate the lesion. Therefore, when applying a coating agent to the balloon portion of such a balloon catheter, a masking member is sometimes placed on the balloon to provide a non-coated area where no coating layer is formed in a predetermined position on the balloon.

[0005] For example, Patent Document 1 discloses a masking member that is placed so as to cover a predetermined portion of a medical device such as a guidewire in order to form a surface lubricating layer (coating layer) with a predetermined pattern on the medical device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2017 / 18360 Summary of the Invention [Problem to be solved by the invention]

[0007] One of the considerations when selecting a masking material to be used to form a coating layer on a balloon is its electron beam transmittance. For example, when forming a coating layer using a masking material, as described above, the masking material is fixed to the balloon to define a non-coated area where the coating material will not be applied. Then, with the masking material fixed to the balloon, the coating material is applied to the target area of the balloon catheter, including the balloon, by dipping or other methods. After the coating material is applied, the masking material is fixed to the non-coated area of the balloon, and the balloon catheter is irradiated with electron beams to cure the coating material. If the electron beam penetrates the masking material too much and reaches the non-coated area of the balloon, the electron beam can cause oxidation reactions or molecular chain scission, degrading the resin that makes up the balloon, potentially resulting in product defects such as changes in the balloon's inflation behavior or reduced pressure resistance.

[0008] In order to solve the above-mentioned problems, the inventors of the present invention have invented a masking member that can prevent the excessive influence of electron beams on the masked, uncoated areas of a balloon when irradiated with electron beams, and a method for forming a coating layer using the masking member.

[0009] The present invention aims to provide a masking member that can prevent the excessive influence of electron beams on masked, uncoated areas of a balloon when irradiated with electron beams, and a method for forming a coating layer using the masking member. [Means for solving the problem]

[0010] The present invention is achieved by any one of the following means (1) to (10).

[0011] (1) A masking member used to mask a predetermined position on a balloon when applying a coating agent that is cured by electron beam irradiation, a lumen extending continuously for a predetermined length along the extension direction of the balloon; A masking material having a thickness of 50 μm or more.

[0012] (2) Density is 0.90g / cm 3 More than 1.39g / cm 3 The following resin materials or materials with a density of 7.75 g / cm 3 More than 21.45g / cm 3 The masking member according to (1) above, which is made of the following metal material:

[0013] (3) The masking member according to (2) above, wherein the resin material is made of an aromatic resin.

[0014] (4) the resin material is any one of polystyrene, polyether ether ketone, and polyethylene terephthalate; The masking member according to (2) or (3) above, wherein the metal material is any one of lead, stainless steel, iron, platinum, and gold.

[0015] (5) The masking member according to any one of (1) to (4) above, wherein the thickness is 350 μm or less.

[0016] (6) The inner diameter is 0.7 mm or more and 6.0 mm or less. The outer diameter is between 0.8mm and 6.7mm. The masking member according to any one of (1) to (5) above, which is configured in a cylindrical shape having a length along the extension direction of the balloon of 5.0 mm or more and 50 mm or less.

[0017] (7) The masking member according to any one of (1) to (6) above, wherein the length along the extending direction of the balloon is equal to or less than the length of the straight portion of the balloon.

[0018] (8) A method for forming a coating layer at a predetermined position of a balloon catheter using the masking member according to any one of (1) to (7) above, The masking member is fixed to at least a portion of a balloon of a balloon catheter, thereby masking at least a portion of the balloon; a predetermined position of the balloon catheter is covered with the coating agent; A method for forming a coating layer, comprising irradiating a predetermined position of the balloon catheter covered with the coating agent with an electron beam while the masking member is fixed to the balloon.

[0019] (9) The method for forming a coating layer according to (8) above, wherein the masking member is fixed to the balloon in a state where it covers at least the straight portion of the balloon.

[0020] (10) The masking member is disposed on the outer periphery of the balloon in a deflated state. Fixing the masking member to the balloon by expanding and deforming the balloon to a diameter smaller than the maximum expanded diameter; The method for forming a coating layer according to (8) or (9) above, wherein after the electron beam irradiation, the balloon is deflated and removed from the masking member. [Effects of the Invention]

[0021] The masking member and coating layer forming method according to the present invention can prevent the electron beam irradiated onto the balloon catheter when curing the coating applied to the balloon catheter from reaching the masked uncoated areas of the balloon, thereby preventing the electron beam from excessively affecting the uncoated areas of the balloon and preventing a deterioration in the product quality of the balloon catheter. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram showing a balloon catheter according to an embodiment. FIG. [Figure 2] 1 is an axial cross-sectional view of the vicinity of the tip of a balloon catheter according to an embodiment. FIG. [Figure 3] 10A to 10C are cross-sectional views for explaining a method for forming a coating layer using a masking member according to an embodiment. [Figure 4] 10A to 10C are cross-sectional views for explaining a method for forming a coating layer using a masking member according to an embodiment. [Figure 5] 10A to 10C are diagrams for explaining a method for forming a coating layer using a masking member according to an embodiment. [Figure 6] 10A to 10C are cross-sectional views for explaining a method for forming a coating layer using a masking member according to an embodiment. [Figure 7] 10A to 10C are cross-sectional views for explaining a method for forming a coating layer using a masking member according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0024] FIG. 1 is a diagram showing the overall configuration of a balloon catheter 1 according to an embodiment, FIG. 2 is a cross-sectional view of the vicinity of the tip of the balloon catheter 1 according to an embodiment, and FIGS. 3 to 7 are diagrams for explaining a method of forming a coating layer 80 using a masking member 100 according to an embodiment.

[0025] <Balloon catheter 1> 1 and 2 show a balloon catheter 1 according to this embodiment. The balloon catheter 1 can be configured as a medical device used, for example, in PCI (Percutaneous Coronary Intervention). However, the uses of the balloon catheter 1 are not limited to the above, and it can also be configured as a medical device intended to treat lesions such as strictures formed in biological organs, such as other blood vessels, bile ducts, tracheas, esophagus, other digestive tracts, urethras, ear and nose cavities, and other organs.

[0026] As shown in FIG. 1, the balloon catheter 1 comprises a balloon 20 that can expand and contract as fluid is injected and discharged, a distal tip 30 disposed at the distal end of the balloon 20, a flexible, elongated shaft portion 50 to which the balloon 20 and the distal tip 30 are fixed, a hub portion 90 disposed at the proximal end of the shaft portion 50, and a coating layer 80 disposed at a predetermined position on the balloon catheter 1.

[0027] In this specification, the side of the balloon catheter 1 that is introduced into the living body (the side where the distal tip 30 is located) is referred to as the distal side, and the end of each member and component located on the distal side is referred to as the "distal portion." Furthermore, the side of the balloon catheter 1 where the hub portion 90 is located is referred to as the proximal side, and the end of each member and component located on the proximal side is referred to as the "proximal portion." Furthermore, the direction from the distal portion toward the proximal portion (or from the proximal portion toward the distal portion) is referred to as the "axial direction (longitudinal direction)."

[0028] As shown in Figures 1 and 2, the balloon 20 comprises a tip fixing portion 26 and a base end fixing portion 27 fixed to the shaft portion 50, a straight portion 21 which has a substantially linear cross-sectional shape along the axial direction when expanded, a tip tapered portion 22 which has a cross-sectional shape in which the outer diameter gradually decreases from the tip of the straight portion 21 toward the tip fixing portion 26, and a base end tapered portion 23 which has a cross-sectional shape in which the outer diameter gradually decreases from the base end of the straight portion 21 toward the base end fixing portion 27.

[0029] The balloon 20 is made of a flexible membrane-like member and is fixed to the shaft portion 50 so as to define an internal space 25 into which a fluid can flow between the balloon 20 and an inner shaft 70 provided in the shaft portion 50.

[0030] The straight portion 21 of the balloon 20 is placed at a lesion such as a stenosis in a procedure using the balloon catheter 1, and applies pressure to the lesion as the balloon 20 expands.

[0031] For the sake of simplicity in explaining the present invention, the present specification illustrates the balloon 20 in an expanded state. However, in reality, the balloon 20 is folded into a predetermined shape before expansion and is prepared in a state where it is wrapped around the shaft portion 50. The folded shape of the balloon 20 and the shape when wrapped around the shaft portion 50 may be any suitable configuration known in the field of balloon catheters.

[0032] The balloon 20 can be formed from, for example, polyethylene, polypropylene, polyolefins such as ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers, thermoplastic resins such as polyurethane, polyamide, polyamide elastomer, polystyrene elastomer, silicone rubber, latex rubber, etc.

[0033] An indeflator can be connected to the hub portion 90 disposed at the base end of the shaft portion 50 to supply various fluids (pressurized media) to the internal space 25 of the balloon 20 or to discharge fluids from the internal space 25 of the balloon 20. The hub portion 90 can be configured using a device known in the field of medical devices such as catheters.

[0034] The distal tip 30 is fixed to an inner shaft 70 provided in the shaft portion 50. The distal tip 30 is positioned to prevent damage to a biological organ (such as the inner wall of a blood vessel) when the distal end of the balloon catheter 1 comes into contact with the biological organ.

[0035] The distal tip 30 can be configured as a hollow member having an inner cavity 31 through which a guide wire can be inserted.

[0036] The distal tip 30 can be made of, for example, a material that is more flexible than the shaft portion 50. Materials that can be used to make the distal tip 30 include, for example, polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, and the like.

[0037] As shown in FIGS. 1 and 2, the shaft portion 50 includes an outer shaft 60 and an inner shaft 70 .

[0038] The inner shaft 70 is positioned so as to pass through the lumen 65 of the outer shaft 60. The distal end of the inner shaft 70 protrudes a predetermined length toward the distal side beyond the outer shaft 60. The distal end fixing portion 26 of the balloon 20 is fixed to the distal end of the inner shaft 70, and the proximal end fixing portion 27 of the balloon 20 is fixed to the distal end of the outer shaft 60.

[0039] The inner cavity 65 of the outer shaft 60 communicates with the internal space 25 of the balloon 20 and constitutes a pressurized medium lumen through which the fluid supplied via the hub portion 90 flows.

[0040] The balloon catheter 1 is configured as a rapid exchange catheter. As shown in Figure 1, the base end of the inner shaft 70 forms a guidewire port 55, which serves as an entrance and exit for inserting a guidewire into the shaft portion 50. The inner cavity 75 of the inner shaft 70 forms a guidewire lumen through which a guidewire can be inserted. The balloon catheter 1 can also be configured as an over-the-wire catheter.

[0041] The outer shaft 60 and the inner shaft 70 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.

[0042] 1, a radiopaque marker 40 having radiopaque properties can be placed at any position of the shaft portion 50 (inner shaft 70) that overlaps with the balloon 20. The radiopaque marker 40 can be made of, for example, a known metallic material that is radiopaque.

[0043] The coating layer 80 is provided at a predetermined position on the balloon catheter 1. In this embodiment, as shown in Figures 1 and 2, the coating layer 80 is provided between the distal end of the balloon catheter 1 (the position where the distal tip 30 is disposed) and the distal end of the straight section 21 of the balloon 20 (near the boundary between the straight section 21 and the distal tapered section 22), and between the proximal end of the straight section 21 of the balloon 20 (near the boundary between the straight section 21 and the proximal tapered section 23) and near the distal end of the guidewire port 55. In other words, as shown in Figure 2, the straight section 21 of the balloon 20 forms an "uncoated region N" where the coating layer 80 hardened by electron beam irradiation is not provided.

[0044] Hereinafter, in this embodiment, the coating layer 80 formed between the tip of the balloon catheter 1 and the tip of the straight section 21 of the balloon 20 will be referred to as the "first coating layer 81." Furthermore, the coating layer 80 formed between the base end of the straight section 21 of the balloon 20 and near the tip of the guidewire port 55 will be referred to as the "second coating layer 82." Note that, although the above two regions are exemplified as regions where the coating layer 80 is to be provided in this embodiment, the position where the coating layer 80 is to be provided can be set arbitrarily depending on the product specifications of the balloon catheter 1, etc.

[0045] The above "non-coated area N" means an area where the coating agent 210 described below is not applied (an area where the coating layer 80 is not formed), and does not define that other coating layers, such as a drug layer, are not provided.

[0046] The coating layer 80 is formed by irradiating a coating agent 210 (see FIG. 5) applied to the balloon catheter 1 with an electron beam to harden it (see FIGS. 5 and 6). As will be described later, a masking member 100 (see FIGS. 3, 5, etc.) is used in the method of forming the coating layer 80 to configure the straight portion 21 as a non-coated region N.

[0047] The coating agent 210 constituting the coating layer 80 (first coating layer 81, second coating layer 82) may be any material that absorbs water and exhibits lubricity. Examples of the coating agent 210 include hydrophilic materials. Specific examples are shown below. In the specific examples, the term "(meth)acrylic" encompasses both acrylic and methacrylic. Thus, for example, the term "(meth)acrylic acid" encompasses both acrylic acid and methacrylic acid. Similarly, the term "(meth)acryloyl" encompasses both acryloyl and methacryloyl. Thus, for example, the term "(meth)acryloyl group" encompasses both acryloyl and methacryloyl groups.

[0048] Examples of hydrophilic materials that make up the coating agent 210 include hydrophilic polymers such as polyvinylpyrrolidone, polyvinyl alcohol, polyethylene oxide-based polymers, cellulose-based polymers such as carboxymethyl cellulose, acrylamide-based polymers such as polyacrylamide and polydimethylacrylamide, hyaluronic acid, polyacrylic acid, maleic anhydride-based polymers such as maleic anhydride-methyl vinyl ether copolymer, water-soluble nylon (registered trademark), and derivatives thereof.

[0049] The hydrophilic material constituting the coating agent 210 may be a hydrophilic copolymer containing a monomer having a reactive functional group (hereinafter also referred to as a "reactive monomer") and a hydrophilic monomer, in order to firmly fix the hydrophilic polymer to a predetermined portion of the balloon catheter 1 (for example, a portion of the balloon 20 other than the straight portion 21 or the shaft portion 50). The "reactive functional group" here refers to a functional group that can undergo a crosslinking reaction with other monomers or can react (bond) with the surface of the balloon catheter 1 by electron beam irradiation or the like.

[0050] The reactive functional group is not particularly limited, and may be a functional group such as an epoxy group, an acid halide group, an aldehyde group, an isocyanate group, an acid anhydride group, a vinyl group, a (meth)acryloyl group, etc. These reactive functional groups may be present alone or in combination in the reactive monomer.

[0051] The reactive monomer used in the present invention preferably has a reactive functional group and exhibits hydrophobicity in body fluids or aqueous solvents at least greater than that of the hydrophilic monomer used in producing the copolymer. Specific examples of such reactive monomers include monomers having an epoxy group in the molecule, such as glycidyl acrylate, glycidyl methacrylate (GMA), methyl glycidyl methacrylate, and allyl glycidyl ether; monomers having an acid halide group in the molecule, such as (meth)acrylic acid chloride, (meth)acrylic acid bromide, and (meth)acrylic acid iodide; monomers having an aldehyde group in the molecule, such as (meth)acrylic aldehyde, crotonaldehyde, acrolein, and methacrolein; (meth)acryloyloxymethyl isocyanate; Examples of reactive monomers include monomers having an isocyanate group in the molecule, such as (meth)acryloyloxyethyl isocyanate, (meth)acryloyloxypropyl isocyanate, and (meth)acryloyl isocyanate; monomers having an acid anhydride group in the molecule, such as maleic anhydride, itaconic anhydride, and citraconic anhydride; and monomers having a vinyl group in the molecule, such as vinyl chloride. Preferred are monomers having an epoxy group in the molecule, such as glycidyl acrylate, glycidyl methacrylate (GMA), methyl glycidyl methacrylate, and allyl glycidyl ether. These reactive monomers can be used alone or in combination of two or more.

[0052] The hydrophilic monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, N-methylacrylamide, N,N-dimethylacrylamide (DMAA), acrylamide, acryloylmorpholine, N,N-dimethylaminoethyl acrylate, vinylpyrrolidone, 2-methacryloyloxyethyl phosphorylcholine, 2-methacryloyloxyethyl-D-glycoside, 2-methacryloyloxyethyl-D-mannoside, vinyl methyl ether, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 1-chloro-2-hydroxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, Examples of hydrophilic monomers include acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, 2-hydroxy-3-phenyloxypropyl(meth)acrylate, 4-hydroxycyclohexyl(meth)acrylate, 2-hydroxy-3-phenyloxy(meth)acrylate, 4-hydroxycyclohexyl(meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, poly(ethylene glycol) methyl ether acrylate, and poly(ethylene glycol) methyl ether methacrylate. Preferred are N,N-dimethylacrylamide, acrylamide, acrylic acid, methacrylic acid, N,N-dimethylaminoethyl acrylate, 2-hydroxyethyl acrylate, and vinylpyrrolidone. These hydrophilic monomers can be used alone or in combination of two or more.

[0053] The hydrophilic material constituting the coating agent 210 may be a material containing only a hydrophilic monomer in order to easily and firmly fix the hydrophilic polymer to the balloon catheter 1. In this case, the hydrophilic monomer contains a (meth)acryloyl group that can undergo a crosslinking reaction with other hydrophilic monomers or react (bond) with the surface of each part of the balloon catheter 1 upon electron beam irradiation. For example, such a hydrophilic monomer is a hydrophilic monomer containing a (meth)acryloyl group among the hydrophilic monomers described above. The material containing only a hydrophilic monomer is preferably a material containing a single or a combination of two or more of the hydrophilic monomers containing a (meth)acryloyl group among the hydrophilic monomers described above.

[0054] The viscosity of the coating agent 210 can be set at any value depending on the materials used and the environment in which the method for forming the coating layer 80 is carried out, but can be, for example, 15 mPa·s or more and 25 Pa·s or less.

[0055] <Masking member 100> As shown in FIGS. 3 to 7, the masking member 100 is used to mask predetermined positions of the balloon 20 when applying a coating agent 210 that is cured by electron beam irradiation.

[0056] In this embodiment, an example of application of the masking member 100 to a method for forming a coating layer 80 for forming a non-coated region N where the coating layer 80 is not formed on the straight portion 21 of the balloon 20 will be described (see FIGS. 3 to 7). That is, in the method for forming the coating layer 80 described below, the masking member 100 is fixed to the balloon 20 so as to cover all or at least a part of the straight portion 21.

[0057] As shown in FIG. 3, the masking member 100 has a lumen 115 that extends continuously for a predetermined length along the extension direction of the balloon 20 (the same direction as the axial direction of the shaft portion 50).

[0058] The masking member 100 is configured as a hollow member having a substantially constant inner diameter d and outer diameter D in the axial direction. A distal end portion 116 of the masking member 100 in the axial direction is provided with a distal end opening 116a that communicates with the lumen 115. In addition, a proximal end portion 117 of the masking member 100 in the axial direction is provided with a proximal end opening 117a that communicates with the lumen 115.

[0059] As described above, the masking member 100 has the lumen 115 that extends continuously for a predetermined length along the axial direction, and therefore, when fixed to the balloon 20, it can continuously cover any range along the axial direction of the balloon 20. Therefore, by using the masking member 100, it is possible to form an uncoated region N that extends continuously along any range along the axial direction of the balloon 20.

[0060] The thickness t of the masking member 100 can be set to 50 μm or more. When the thickness t of the masking member 100 is set to 50 μm or more, when the masking member 100 is fixed to the straight portion 21 of the balloon 20 and an electron beam of a predetermined energy is irradiated from the outer surface side of the masking member 100 (see FIG. 6), the electron beam can cause an oxidation reaction or molecular chain scission, which can deteriorate the resin that makes up the balloon and cause changes in the way the balloon expands or a decrease in pressure resistance, thereby preventing product defects.

[0061] As described above, the thickness t of the masking member 100 is preferably 50 μm or greater, taking into consideration the effect of the electron beam on the balloon 20. However, if the thickness t is excessively large, as described below, when the coating agent 210 is applied to the balloon catheter 1, the thickness t of the masking member 100 will cause a step due to a pool of coating agent 210 to form near the boundary between the uncoated region N and the coated region to which the coating agent 210 is applied. If such a step occurs, peeling of the coating layer 80 and scattering of fine particles of the material that makes up the coating layer 80 may occur during use of the balloon catheter 1. The thickness of the masking member 100 is preferably 80 μm or less to prevent the formation of a step due to the pool of coating agent 210.

[0062] From the viewpoint of both reducing the effect of the electron beam on the balloon 20 and preventing the occurrence of liquid pools, the masking member 100 is preferably, for example, greater than 50 μm and smaller than 350 μm, and more preferably 50 μm to 150 μm.

[0063] The masking member 100 has a density of, for example, 0.90 g / cm 3 More than 1.39g / cm 3 It can be made of the following resin materials.

[0064] By forming the masking member 100 from a resin material having the above density, it is possible to effectively prevent the electron beam from passing through the masking member 100 and from affecting the non-coated region N excessively.

[0065] The resin material is preferably a material that is highly resistant to radiation such as electron beams, and more specifically, a material that is unlikely to generate radicals and is highly stable (low reactivity), and is unlikely to crosslink or decompose. More specifically, the resin material is preferably one that contains a benzene ring in its structure, and an aromatic resin is one example that can be suitably used.

[0066] The aromatic resin may have a density of 1.04 g / cm 3More than 1.07g / cm 3 Polystyrene with a density of 1.38 g / cm 3 More than 1.39g / cm 3 Polyethylene terephthalate with a density of 1.3 g / cm 3 Any of the polyether ether ketones listed above can be suitably selected.

[0067] The masking member 100 has a density of, for example, 7.75 g / cm 3 More than 21.45g / cm 3 It can also be made of the following metal materials:

[0068] By being made of a metal material having the density described above, the masking member 100 can effectively prevent the electron beam from passing through the masking member 100 and having an excessive effect on the non-coated area N, similar to the resin material having the predetermined density described above.

[0069] For example, a metal material with a density of 21.45 g / cm 3 of platinum, density is 11.35g / cm 3 of lead, density is 19.32 g / cm 3 and gold with a density of 7.75 to 7.93 g / cm 3 Any of the following stainless steels (SUS303, SUS304, SUS316, SUS430, SUS444, SUS403, SUS410, SUS440) can be suitably selected.

[0070] In addition, when the masking member 100 is made of a metal material, it is preferable that the tip end 116 and base end 117 of the masking member 100 are chamfered to prevent damage to the balloon 20 when the masking member 100 is positioned and fixed to the balloon 20.

[0071] The masking member 100 can be configured in a cylindrical shape, for example, with an inner diameter d of 0.7 mm or more and 6.0 mm or less, an outer diameter D of 0.8 mm or more and 6.7 mm or less, and a length (axial length) L along the extension direction of the balloon 20 of 5.0 mm or more and 50 mm or less.

[0072] The masking member 100 has the dimensions of each part configured as described above, so that it is possible to form a non-coated region N in any desired area of the balloon 20 of the balloon catheter 1.

[0073] When an uncoated region N is formed in the straight portion 21 of the balloon 20, the length L of the masking member 100 can be equal to or less than the length of the straight portion 21 of the balloon 20. The length of the straight portion 21 of the balloon 20 can vary depending on the product type of the balloon catheter 1, but in this embodiment, it is, for example, 5 mm or more and 50 mm or less. Therefore, when an uncoated region N is formed in the entire axial direction of the straight portion 21 of the balloon 20 or in part of the axial direction of the straight portion 21, it is more preferable that the length L of the masking member 100 be, for example, 50 mm or less.

[0074] <Method of forming a coating layer> Next, a method for forming the coating layer 80 according to this embodiment will be described.

[0075] In the method for forming the coating layer 80 according to this embodiment, the masking member 100 is used to form the coating layer 80 at a predetermined position on the balloon catheter 1. As described above, this embodiment describes a method for forming the coating layer 80 that forms the first coating layer 81 and the second coating layer 82 (see FIGS. 1 and 2) on the balloon catheter 1 and also forms the non-coated region N over the entire axial direction (full length) of the straight portion 21 of the balloon 20.

[0076] 3, when the balloon 20 is in a deflated state, the masking member 100 is placed on the outer periphery of the balloon 20. At this time, the straight portion 21 of the balloon 20 is inserted into the lumen 115 of the masking member 100 through the proximal opening 117a of the masking member 100, and the straight portion 21 is covered with the masking member 100.

[0077] Next, as shown in FIG. 4 , the masking member 100 is secured to the balloon 20 by expanding and deforming the balloon 20 to a diameter smaller than its maximum expansion diameter (RBP: Rated Burst Pressure). The expansion of the balloon 20 can be performed by connecting a predetermined injection tool to the hub portion 90. By expanding the balloon 20 disposed in the lumen 115 of the masking member 100, the expansion force of the balloon 20 can be utilized to secure the masking member 100 to the straight portion 21. By securing the masking member 100 to the straight portion 21, the straight portion 21 can be masked. By expanding the balloon 20 and securing the masking member 100 to the balloon 20 in this manner, there is no need to separately prepare or use a jig or the like for securing the masking member 100 to the balloon 20. This improves work efficiency and reduces manufacturing costs. The maximum expansion diameter of the balloon 20 can be set to any size depending on the type of balloon catheter 1, but in this embodiment, it is set to, for example, 0.75 mm to 6.00 mm.

[0078] Next, a coating agent 210 is applied to any area on the distal end of the balloon catheter 1, excluding the non-coated region N (straight portion 21). There are no particular limitations on the method for applying the coating agent 210; for example, dip coating can be used. As shown in FIG. 5, a preparatory item 1A (an intermediate product prior to the completion of the coating layer 80) for the balloon catheter 1 is immersed from the distal end into the coating agent 210 stored in a reservoir 200, and the coating agent 210 is applied to the first coated area 81a corresponding to the first coating layer 81 and the second coated area 82a corresponding to the second coating layer 82. A masking member 100 is fixed to the straight portion 21 of the balloon 20 of the preparatory item 1A, preventing the coating agent 210 from being applied to the straight portion 21 of the balloon 20 when the preparatory item 1A is immersed in the coating agent 210.

[0079] After the coating agent 210 is applied to a predetermined area of the preparation 1A, the preparation 1A is removed from the storage tank 200.

[0080] Next, as shown in FIG. 6, to harden the coating agent 210 applied to the preparatory item 1A, an electron beam is irradiated onto the preparatory item 1A from an electron beam irradiation unit 300 provided in a known electron beam irradiation device (the irradiation of the electron beam is indicated by arrow e in the figure). When the preparatory item 1A is irradiated with an electron beam, the masking member 100 remains fixed to the straight portion 21 of the balloon 20. When the preparatory item 1A is irradiated with an electron beam, the coating agent 210 irradiated with the electron beam hardens. As the coating agent 210 hardens, a first coating layer 81 and a second coating layer 82 can be formed at predetermined positions on the balloon catheter 1. When the balloon catheter 1 is irradiated with an electron beam, the masking member 100 is fixed to the straight portion 21 of the balloon 20, effectively preventing the straight portion 21 of the balloon 20 from being excessively affected by the electron beam.

[0081] Furthermore, since the masking member 100 can prevent the electron beam from reaching the straight portion 21 of the balloon 20, the masking prevents the coating agent 210 from being applied to the straight portion 21 in the process of applying the coating agent 210 to the preparation 1A (dipping process), and further prevents the straight portion 21 from being excessively affected by the electron beam irradiation in the subsequent process of irradiating the preparation 1A. Therefore, in the method of forming the coating layer 80 using the masking member 100, after completing the process of applying the coating agent 210 to the preparation 1A, by maintaining the masking member 100 fixed to the straight portion 21, the process of irradiating the electron beam can be started without performing work such as replacing the masking member 100 with another protective member to protect the straight portion 21 from the electron beam irradiation. Therefore, the number of jigs used in the method of forming the coating layer 80 can be reduced and the manufacturing process can be simplified.

[0082] There are no particular limitations on the various conditions for curing the coating agent 210 by electron beam irradiation, as long as the coating layer 80 can be formed by curing the coating agent 210 made of the above-mentioned materials at predetermined positions (in this embodiment, positions corresponding to the areas where the first coating layer 81 and the second coating layer 82 are to be formed) of the balloon catheter 1. As an example, the energy of the electron beam irradiated from the electron beam irradiator 300 can be set to 50 keV or more and 70 keV or less, and the irradiation distance (the distance from the emission end of the electron beam irradiator 300 to the surface of the coating agent 210 located at the irradiation target position) can be set to 10 mm.

[0083] Next, as shown in FIG. 7, after the electron beam is irradiated, the balloon 20 is deflated and removed from the masking member 100.

[0084] By using the above-described procedure, any desired position on the balloon 20 of the balloon catheter 1 (for example, the entire axial direction of the straight section 21 or a portion thereof) can be masked with the masking member 100, thereby providing a non-coated region N at the desired position where the coating layer 80 is not formed. Furthermore, by using the masking member 100, the effects of the electron beams irradiated onto the non-coated region N can be effectively prevented, thereby preventing a decrease in the product quality of the balloon catheter 1.

[0085] In the above-mentioned method of forming the coating layer 80, a method of providing a non-coated area N over the entire axial direction (extension direction) of the straight section 21 and a masking member 100 used in such a method have been exemplified, but the range in which the non-coated area N is provided on the balloon 20 only needs to be at least a part of the axial direction of the balloon 20, and is not limited to only the entire straight section 21 as described above.

[0086] As described above, the masking member 100 according to this embodiment is a masking member 100 used to mask a predetermined position of the balloon 20 when applying a coating agent 210 that is cured by electron beam irradiation, and has an inner cavity 115 that extends continuously for a predetermined length along the extension direction of the balloon 20, and has a wall thickness of 50 μm or more.

[0087] Furthermore, the method for forming the coating layer 80 according to this embodiment is a method for forming the coating layer 80 at a predetermined position on the balloon catheter 1 using a masking member 100, and includes fixing the masking member 100 to at least a portion of the balloon 20 of the balloon catheter 1, masking at least a portion of the balloon 20, covering the predetermined position on the balloon catheter 1 with a coating agent 210, and, with the masking member 100 fixed to the balloon 20, irradiating the predetermined position on the balloon catheter 1 covered with the coating agent 210 with an electron beam.

[0088] The masking member 100 and the method for forming the coating layer 80 according to this embodiment can prevent the electron beam irradiated onto the balloon catheter 1 when curing the coating agent 210 applied to the balloon catheter 1 from reaching the masked uncoated region N of the balloon 20. This prevents the electron beam from causing oxidation reactions or molecular chain scission, which could degrade the resin constituting the balloon 20 and cause changes in the inflation behavior of the balloon 20 or a decrease in pressure resistance. Furthermore, because the uncoated region N can be provided on at least a portion of the balloon 20 (for example, the entire or part of the straight portion 21), excessive slippage of the balloon 20 can be prevented when the balloon 20 is used to dilate a lesion.

[0089] Although the masking member and coating layer forming method according to the present invention have been described through the embodiments, the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the claims.

[0090] The balloon catheter can also be configured as a stent delivery catheter, for example, with a stent mounted on the straight portion of the balloon. When the balloon catheter is configured as a stent delivery catheter, the stent can be crimped and held in place on the straight portion of the balloon, which has an uncoated region. A stent delivery catheter configured in this manner can prevent the stent from falling off the balloon while maintaining its passability to lesions and the like due to the coating layer provided at a predetermined position on the balloon catheter, allowing the stent to be more appropriately placed at the lesion. The stent can also be configured as a DES (Drug-Eluting Stent) with a drug layer. When the stent is configured as a DES, the efficacy of the drug on the lesion can be effectively exerted.

[0091] The balloon catheter can also be configured as a DCB (Drug Coated Balloon), in which a drug layer is placed on the uncoated area of the balloon. A DCB configured in this way can prevent the drug layer placed on the balloon from peeling off while maintaining permeability to the lesion, etc., thanks to the coating layer provided at a predetermined location on the balloon catheter, allowing the balloon to be delivered to the lesion more appropriately. This allows the efficacy of the drug layer to be exerted more effectively. [Explanation of symbols]

[0092] 1 balloon catheter 1A Prepared items 20 Balloon 21 Straight section 22 Tapered tip 23 Base end tapered section 25 Interior Space 50 shaft section 55 Guidewire port 60 outer shaft 70 Inner shaft 80 coat layers 81 First Coat Layer 81a Second court area 82 Second Coat Layer 82a Second Court Area 90 Hub 100 Masking material 115 Lumen 116 Tip 116a Tip opening 117 Proximal end 117a Proximal opening N Uncoated area D Outer diameter of masking material d Inner diameter of masking material t Masking material thickness 200 Reservoir 210 Coating agent 300 Electron beam irradiation unit

Claims

1. A masking member used to mask a predetermined position on a balloon when applying a coating agent that is cured by electron beam irradiation, a lumen extending continuously for a predetermined length along the extension direction of the balloon; A masking member having a thickness of 50 μm or more.

2. Density is 0.90 g / cm ３ 1.39g / cm or more ３ The following resin materials or materials with a density of 7.75 g / cm ３ 21.45g / cm or more ３ The masking member according to claim 1, which is made of the following metal material:

3. The masking member according to claim 2 , wherein the resin material is an aromatic resin.

4. the resin material is any one of polystyrene, polyether ether ketone, and polyethylene terephthalate; 4. The masking member according to claim 2, wherein the metal material is any one of lead, stainless steel, iron, platinum, and gold.

5. The masking member according to claim 1 , wherein the thickness is 350 μm or less.

6. An inner diameter of 0.7 mm or more and 6.0 mm or less; An outer diameter of 0.8 mm or more and 6.7 mm or less; The masking member according to claim 1 , which is configured in a cylindrical shape having a length along the extension direction of the balloon of 5.0 mm or more and 50 mm or less.

7. The masking member according to claim 6 , wherein the length of the masking member along the extension direction of the balloon is equal to or less than the length of a straight portion of the balloon.

8. 10. A method for forming a coating layer at a predetermined position on a balloon catheter using the masking member according to claim 1, comprising: The masking member is fixed to at least a portion of the balloon of the balloon catheter, thereby masking at least a portion of the balloon; a predetermined position of the balloon catheter is covered with the coating agent; A method for forming a coating layer, comprising irradiating a predetermined position of the balloon catheter covered with the coating agent with an electron beam while the masking member is fixed to the balloon.

9. The method for forming a coating layer according to claim 8 , wherein the masking member is fixed to the balloon in a state where it covers at least a straight portion of the balloon.

10. The masking member is disposed on the outer periphery of the balloon in a deflated state. Fixing the masking member to the balloon by expanding and deforming the balloon to a diameter smaller than the maximum expanded diameter; 10. The method for forming a coating layer according to claim 8, wherein after the electron beam irradiation, the balloon is deflated and removed from the masking member.

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