Long medical device and method for manufacturing long medical device

Abstract

A long medical device (1) is provided with a long body (10) extending from the tip side toward the base end side, and a swelling coating layer (20) provided on at least a portion of the surface of the long body (10), the swelling coating layer (20) being provided with a first portion (21) and a second portion (22) disposed closer to the base end side than the first portion (21). The thickness of the first portion (21) after the swellable coating layer (20) is swelled by immersing the elongated medical device (1) in water at 37 DEG C for 120 minutes is thicker than the thickness of the second portion (22), and the degree of swelling of the swellable coating layer (20) as defined by formula (1) in the second portion (22) is smaller than the degree of swelling of the swellable coating layer (20) as defined by formula (1) in the first portion (21). Swelling degree = (thickness after swelling) / (thickness before swelling)... (1). This long medical device (1) exhibits excellent lubricity and is capable of suppressing the generation of microparticles.

Description

Technical Field

[0001] This invention relates to a long strip-shaped medical device and a method for manufacturing such a device. Background Technology

[0002] In long, thin medical devices such as guidewires, stents, and catheters that are inserted into the body, the biological tissues need to be lubricated in order to prevent damage to blood vessels and other biological tissues that they come into contact with within the body and to improve the operability of the long, thin medical device.

[0003] Therefore, a coating made of hydrophilic polymers or the like is formed on the surface of such elongated medical devices. For example, Patent Document 1 discloses an endoscope device having a lubricating coating material with a thickness on the front end side that is thicker than that on the base end side. Furthermore, Patent Document 2 discloses a guidewire having a lubricating resin coating layer with a density gradient of lubricating resin, where the frictional resistance decreases from the base end side to the front end side.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-150040

[0007] Patent Document 2: Japanese Patent Application Publication No. 2006-192294 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in conventional elongated medical devices with the aforementioned coating, friction occurs between the coating and the biological tissue when it is inserted into the body cavity, and a portion of the coating may be abraded, generating microparticles.

[0010] The purpose of this invention is to provide a strip-shaped medical device that exhibits excellent lubricity and is able to suppress the generation of microparticles.

[0011] Solution for solving the problem

[0012] To achieve the above objectives, firstly, the present invention provides a strip-shaped medical device comprising a strip extending from a front end to a base end and a swellable coating disposed on at least a portion of the surface of the strip, wherein the swellable coating comprises a first portion and a second portion disposed at a position closer to the base end than the first portion, wherein the thickness of the first portion after the swellable coating has swelled by immersing the strip-shaped medical device in water at 37°C for 120 minutes is greater than the thickness of the second portion, and the degree of swelling of the swellable coating of the second portion, as defined by the following formula (1), is smaller than the degree of swelling of the swellable coating of the first portion, as defined by the following formula (1) (Invention 1):

[0013] Swelling degree = (thickness after swelling) ÷ (thickness before swelling) ... (1).

[0014] In the above invention (Invention 1), it is preferred that the swelling coating has a third portion disposed at a position closer to the base end than the second portion, the thickness of the swollen second portion is greater than the thickness of the third portion, and the degree of swelling of the swelling coating of the third portion as defined by the formula (1) is smaller than the degree of swelling of the swelling coating of the second portion as defined by the formula (1) (Invention 2).

[0015] Second, the present invention provides a method for manufacturing a strip-shaped medical device, the strip-shaped medical device having a strip extending from a front end side to a base end side, wherein the manufacturing method includes: a step of preparing the strip formed by directly or indirectly connecting a first strip component I and a second strip component II, the first strip component I being made of a first resin I, the second strip component II being disposed at the base end side of the first strip component I and being made of a second resin II having a swelling degree relative to a first solvent A that is smaller than that of the first resin I; and a coating step of applying a coating containing a crosslinking agent and the first solvent A to at least a portion of the surfaces of the first strip component I and the second strip component II (Invention 3).

[0016] In the above invention (Invention 3), it is preferred that, in the coating process, a swelling coating is formed by applying a coating containing a hydrophilic polymer, a crosslinking agent and a first solvent A to at least a portion of the surfaces of the first elongated component I and the second elongated component II.

[0017] In the above invention (Invention 3), it is preferred that, in the coating process, a base layer is formed by applying a coating containing a base polymer, a crosslinking agent and a first solvent A to at least a portion of the surfaces of the first elongated component I and the second elongated component II. After the coating process, a step is further included in which a swelling coating is formed by applying a coating containing a hydrophilic polymer and a second solvent B to at least a portion of the side of the base layer opposite to the elongated component.

[0018] In the above invention (Invention 3), it is preferred that, in the coating process, an adhesive layer is formed by applying a coating containing a crosslinking agent and the first solvent A to at least a portion of the surfaces of the first elongated component I and the second elongated component II. After the coating process, a step is further included in which a swelling coating is formed by applying a coating containing a hydrophilic polymer and the second solvent B to at least a portion of the adhesive layer on the side opposite to the elongated component.

[0019] Invention Effects

[0020] The elongated medical device of the present invention exhibits excellent lubricity and is able to suppress the generation of microparticles. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view of an elongated medical device according to one embodiment of the present invention.

[0022] Figure 2 This is a schematic cross-sectional view of a long strip-shaped medical device according to another embodiment of the present invention.

[0023] Figure 3 This is a schematic cross-sectional view of a long strip-shaped medical device according to another embodiment of the present invention. Detailed Implementation

[0024] The embodiments of the present invention will be described below.

[0025] exist Figure 1 The figure shows a schematic cross-sectional view of an elongated medical device according to an embodiment of the present invention. Figure 1 The elongated medical device 1 shown includes an elongated body 10 extending from the front end side (left side of the paper) to the base end side (right side of the paper) and a swelling coating 20 disposed on at least a portion of the surface of the elongated body 10. Furthermore, the swelling coating 20 includes a first portion 21 and a second portion 22 disposed at a position closer to the base end side than the first portion 21. It should be noted that... Figure 1 In the elongated medical device 1 shown, the elongated body 10 is depicted as having a tubular shape.

[0026] In the elongated medical device 1 of this embodiment, the thickness of the first portion 21 after the swelling coating 20 is swollen is greater than the thickness of the second portion 22, achieved by immersing the elongated medical device 1 in water at 37°C for 120 minutes. It should be noted that... Figure 1 The elongated medical device 1 shown was immersed under the above conditions and is depicted as being in a state where the swelling coating 20 is fully expanded. (The following is a description of the process.) Figure 2 and Figure 3 The same applies.

[0027] In addition, the swelling degree of the swelling coating 20 of the second part 22, as defined by the following formula (1), is less than the swelling degree of the swelling coating 20 of the first part 21, as defined by the following formula (1).

[0028] Swelling degree = (thickness after swelling) ÷ (thickness before swelling) ... (1)

[0029] In the elongated medical device 1 of this embodiment, the thickness of the first part 21 located on the front end side is greater than the thickness of the second part 22 located on the base end side. As a result, more water is available for lubrication on the front end side, improving the lubricity of the front end side and enhancing the passage of the body cavity.

[0030] Furthermore, the second portion 22 is thinner than the first portion 21, thereby reducing the contact between the swollen coating 20 and the body cavity at locations where lubrication is not required compared to the front end side. Also, the second portion 22 has a smaller degree of swelling than the first portion 21, meaning it has a higher cross-linking density, resulting in greater strength and making wear of the swollen coating 20 at these locations less likely. Consequently, the generation of particles from the swollen coating 20 can be suppressed.

[0031] Furthermore, by making the thickness of the second part 22 thinner than that of the first part 21, the lubricity of the swelling coating 20 is reduced on the base side compared to the front end side. As a result, the long strip-shaped medical device 1 inserted into the body cavity is easily supported (support force is improved), and it has excellent operability.

[0032] As described above, the elongated medical device 1 of this embodiment has excellent lubricity on the front end side, making it less likely to damage the body cavity, and it is less likely to generate particles on the base end side.

[0033] The elongated medical device of the present invention is not limited to Figure 1 The structure shown can also have other forms or structures. For example, in Figure 2 The image shows another embodiment of the elongated medical device 2. Figure 2The elongated medical device 2 shown, like the elongated medical device 1, includes an elongated body 10 and a swelling coating 20, but a base layer 30 is also provided between the elongated body 10 and the swelling coating 20. As described later, the base layer 30 has the function of improving the adhesion of the swelling coating 20 to the elongated body 10. Alternatively, the elongated medical device of the present invention may also include an elongated body 10 and a swelling coating 20, and an adhesive layer disposed therebetween. This adhesive layer, like the base layer 30, also has the function of improving the adhesion of the swelling coating 20 to the elongated body 10.

[0034] In addition, Figure 3 The image shows another embodiment of the elongated medical device 3. Figure 3 The elongated medical device 3 shown has the same elongated body 10 and swelling coating 20 as the elongated medical device 1, but the swelling coating 20, in addition to the first part 21 and the second part 22, also has a third part 23 disposed at a position closer to the base end than the second part 22. The thickness of the third part 23 after swelling is thinner than the thickness of the second part 22 after swelling. In addition, the degree of swelling of the third part 23 as defined by the above formula (1) is smaller than that of the second part.

[0035] and Figure 1 The elongated medical device 1 shown is the same as the one shown. Figure 2 and Figure 3 The elongated medical devices 2 and 3 shown also exhibit excellent lubricity and are able to inhibit the generation of microparticles. It should be noted that... Figure 1 and Figure 2 The elongated medical devices 1 and 2 shown may also contain a third part 23. Additionally, Figure 3 The elongated medical device 3 shown may also have a base layer 30 or an adhesive layer. Furthermore, in these elongated medical devices, there may also be a fourth part (and then a fifth part or beyond) disposed at a position closer to the base end than the third part.

[0036] 1. Elongated body

[0037] In this embodiment, the elongated body 10 only needs to have a shape that extends from the front end side to the base end side, and there is no particular limitation. The internal structure of the elongated body 10 can be solid or hollow. Especially in the latter case, such as Figures 1-3 As shown, the elongated body 10 can be a tubular body with an internal structure having cavities extending along its length.

[0038] The material for the elongated body 10 is not particularly limited and can be appropriately selected according to the elongated medical devices 1, 2, and 3 to be manufactured. Examples of such materials include resin, metal, glass, and ceramics, with resin being preferred.

[0039] The resin constituting the elongated body 10 is not particularly limited, and examples include nylon resins such as polyamide, polyethylene, polypropylene, polyolefins such as ethylene-propylene copolymer, polyesters such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, thermoplastic resins such as polyurethane, polyamide elastomers, polyolefin elastomers, polyurethane elastomers, polystyrene elastomers, silicone rubber, latex rubber, etc.

[0040] In the elongated medical devices 1, 2, and 3 of this embodiment, as described later, the first part 21 and the second part 22 can also be manufactured separately by changing the resin constituting the elongated body 10 in the portion corresponding to the first part 21 and the portion corresponding to the second part 22. In this case, the elongated body 10 may have a first elongated body component disposed at the position where the first part 21 is provided and a second elongated body component disposed at the position where the second part 22 is provided. Furthermore, as... Figure 3 As shown in the elongated medical device 3, when the swelling coating 20 has a third portion 23, the elongated body 10 may also have a third elongated component disposed at the position where the third portion 23 is provided. It should be noted that these first elongated components, second elongated components, and third elongated components may be directly connected or indirectly connected.

[0041] Furthermore, the materials used for the first to third elongated components can be the same polymer or different types of polymers. For example, even when the same polymer is used for each elongated component, by adjusting the monomer composition ratio in the polymer, the swelling degree of each elongated component relative to the solvent can be made different. In this way, even when using the same polymer, it is possible to form elongated components with different swelling degrees relative to a specific solvent from the front end side to the base end side.

[0042] As described above, when the elongated body 10 is composed of the first elongated body component and the second elongated body component (and then the third elongated body component), the material used for the first elongated body component to the third elongated body component is not particularly limited, but is preferably a polyurethane elastomer, a polyolefin elastomer, a polyester elastomer, a polystyrene elastomer, a polyamide elastomer, etc., and is particularly preferably a polyurethane elastomer or a polyamide elastomer.

[0043] Furthermore, even when the first elongated component and the second elongated component (and the third elongated component) are made of the same type of resin, the first part 21 and the second part 22 (and the third part 23) can be manufactured separately by changing the composition ratio of the monomers constituting the resin.

[0044] 2. Swellable coating

[0045] The material constituting the swelling coating 20 in this embodiment is not particularly limited as long as it can exhibit swelling properties and can constitute the aforementioned first part 21 and second part 22.

[0046] In particular, the swelling coating 20 is preferably composed of a resin exhibiting swelling properties. Examples of such resins include polymers having reactive functional groups (hydroxyl, carboxyl, amino, epoxy, etc.), and particularly known hydrophilic substances composed of polysaccharide-based polymers (hyaluronic acid-based polymers, cellulose-based polymers, etc.), polyethylene oxide-based polymers, maleic acid-based polymers, acrylamide copolymers, water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone copolymers, hydroxyl-containing acrylic copolymers, and zwitterionic polymers with hydrophilic groups (polymers with betaine structures, etc.). Hydroxyl-containing acrylic copolymers are preferred. It should be noted that these polymers can be used alone or in combination of two or more.

[0047] It is also preferable to use a crosslinking agent in conjunction with the aforementioned resin. In particular, since the degree of swelling of the swellable coating 20 can be adjusted by the degree of crosslinking of the aforementioned polymer, the desired degree of swelling can be easily achieved by using a crosslinking agent.

[0048] Examples of the aforementioned crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. It should be noted that a single crosslinking agent can be used, or two or more can be used in combination.

[0049] In the case where the polymer has hydroxyl groups as reactive groups, isocyanate-based crosslinking agents with excellent reactivity with hydroxyl groups are preferably used as crosslinking agents.

[0050] Isocyanate-based crosslinking agents contain at least polyisocyanate compounds. Examples of polyisocyanate compounds include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and phenylene diisocyanate; aliphatic polyisocyanates such as pentamethylene diisocyanate and hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; as well as their biuret bodies, isocyanurate bodies, ureocarbamate bodies, and adducts as reactants with compounds containing low-molecular-weight active hydrogen such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Hexamethylene diisocyanate is preferred.

[0051] When a crosslinking agent is used, its amount relative to 100 parts by weight of the above-mentioned resin is preferably 1 to 100 parts by weight, particularly preferably 5 to 80 parts by weight, and even more preferably 10 to 50 parts by weight.

[0052] The method for forming the swelling coating 20 in this embodiment is not particularly limited. For example, the above-mentioned resin and a desired crosslinking agent can be mixed in a predetermined solvent to prepare a coating, which is then applied to the strip 10 (or, if a base layer 30 is present, applied to the base layer 30) and dried to form the coating. Examples of drying conditions include drying at a temperature of room temperature to 150°C, preferably 40 to 100°C, for 1 to 1440 minutes, preferably 20 to 800 minutes.

[0053] Examples of the solvents mentioned above include mixed solvents of water and ethanol, water monomers, ethanol monomers, isopropanol, etc., with mixed solvents of water and ethanol being preferred.

[0054] The thickness of the swelling coating 20 in this embodiment is preferably 0.1 to 100 μm before swelling, particularly preferably 0.5 to 20 μm, and even more preferably 1 to 10 μm. It should be noted that there may be no difference in thickness between the first portion 21 and the second portion 22 (and, if present, the second portion 23) before swelling.

[0055] On the other hand, after the swelling coating 20 of this embodiment is swollen, the thickness of the first portion 21 is preferably 1 to 200 μm, particularly preferably 5 to 100 μm, and even more preferably 10 to 50 μm. Furthermore, the thickness of the second portion 22 is preferably 0.5 to 100 μm, particularly preferably 2 to 80 μm, and even more preferably 3 to 30 μm. Moreover, when a third portion 23 is present, its thickness is preferably 0.1 to 80 μm, particularly preferably 1 to 50 μm, and even more preferably 1 to 30 μm.

[0056] In the swellable coating 20 of this embodiment, regarding the first part 21, the degree of swelling of the swellable coating 20, as defined by the following formula (1), is preferably 10 to 2000, particularly preferably 13 to 200, and even more preferably 15 to 100. Furthermore, regarding the second part 22, the degree of swelling of the swellable coating 20, as defined by the following formula (1), is preferably 5 to 1000, particularly preferably 7 to 800, and even more preferably 8 to 300. Moreover, in the presence of the third part 23, regarding the third part 23, the degree of swelling of the swellable coating 20, as defined by the following formula (1), is preferably 1 to 800, particularly preferably 2 to 500, and even more preferably 3 to 300.

[0057] Swelling degree = (thickness after swelling) ÷ (thickness before swelling) ... (1)

[0058] It should be noted that, in this specification, the conditions for swelling the swelling coating 20, unless otherwise specified, refer to fully swelling the strip-shaped medical devices 1, 2, and 3 by immersing them in water at 37°C for 2 hours.

[0059] 3. Basal layer

[0060] The material constituting the base layer 30 in this embodiment is not particularly limited as long as it allows the swelling coating 20 to adhere tightly to the strip 10. Preferred examples of such materials include (meth)acrylic resins, polyvinyl alcohol resins, poly(hydroxyethyl methacrylate) resins, polyethylene glycol resins, acrylic resins, and maleic acid resins. It should be noted that the aforementioned (meth)acrylic resin can be any resin having a polymer unit based on a monomer having an acryloyl group (H₂C=CH-C(=O)-) or a methacryloyl group (H₂C=C(CH₃)-C(=O)-).

[0061] A crosslinking agent may also be added to the resin used to form the base layer 30. This crosslinking agent can be used to crosslink the resin used to form the base layer 30, or it can be used to crosslink the resin used to form the swelling coating 20. In the latter case, when the coating used to form the swelling coating 20 is applied to the base layer 30, the crosslinking agent is transferred from the base layer 30 to the coating and used to crosslink the resin constituting the swelling coating 20.

[0062] As an example of the aforementioned crosslinking agent, the same crosslinking agent used as the crosslinking agent for the material of the swelling coating 20 can be used. When the crosslinking agent is added to the resin used to form the base layer 30, the amount used is preferably 1 to 100 parts by weight relative to 100 parts by weight of the resin, particularly preferably 5 to 80 parts by weight, and even more preferably 10 to 50 parts by weight.

[0063] The method for forming the base layer 30 in this embodiment is not particularly limited. For example, the above-mentioned resin and a desired crosslinking agent can be mixed in a predetermined solvent to prepare a coating, which is then applied to the strip 10 and dried to form the base layer. Examples of drying conditions include drying at a temperature of room temperature to 150°C, preferably 40 to 100°C, for 1 to 1440 minutes, preferably 20 to 800 minutes.

[0064] Examples of solvents mentioned above include propylene glycol methyl ether acetate (PGMEA), ethyl acetate, butyl acetate, toluene, etc., with propylene glycol methyl ether acetate (PGMEA) being the preferred choice.

[0065] In this embodiment, the thickness of the base layer 30 (before swelling) is preferably 0.1 to 100 μm, particularly preferably 0.5 to 50 μm, and even more preferably 1 to 10 μm.

[0066] 4. The material constituting the adhesive layer in this embodiment is not particularly limited as long as it can ensure close adhesion between the swelling coating 20 and the strip 10. However, the adhesive layer differs from the base layer 30 in that it contains a crosslinking agent as the main material and does not use a polymer component as the main material.

[0067] In a preferred example, the same crosslinking agent as the crosslinking agent used as the material for the swelling coating 20 can be used.

[0068] The method for forming the adhesive layer in this embodiment is not particularly limited. For example, a coating can be prepared by mixing a crosslinking agent in a predetermined solvent, and the coating can be applied to the strip 10 and dried to form the adhesive layer. As an example of the drying conditions, drying at a temperature of room temperature to 150°C, preferably 40 to 100°C, for 1 to 1440 minutes, preferably 20 to 800 minutes, is also possible.

[0069] As an example of the solvent mentioned above, the same solvent as the solvent used for the material of the substrate 30 can be used.

[0070] 5. Long, narrow medical devices

[0071] As for the types of elongated medical devices 1, 2, and 3 in this embodiment, there is no particular limitation as long as they are elongated medical devices that require lubrication for biological tissues. However, long elongated medical devices that are inserted into or placed in the body are generally preferred, and guide wires or catheters are particularly preferred.

[0072] Examples of the catheters described above are not particularly limited; for example, guiding catheters, penetrating catheters, microcatheters, balloon catheters, foreign body removal catheters, contrast catheters, bile duct catheters, urethral catheters, endoscopes, dilators, etc., can be included. Preferably, the catheters described above have a tubular elongated body made of resin extending from the tip to the base, and a swelling coating disposed on the outer periphery of the tubular elongated body. Alternatively, a base layer may be disposed between the tubular elongated body and the swelling coating. Furthermore, the resin used to form the swelling coating on the tubular elongated body with the first portion can be different from the resin used to form the tubular elongated body with the second portion.

[0073] Furthermore, there are no particular limitations on the examples of the guidewires mentioned above. For example, PCI guidewires used for coronary artery treatment, PTA guidewires used for lower extremity vascular treatment, IVR guidewires used for peripheral vascular treatment, INR guidewires used for cerebrovascular treatment, and CAG guidewires used for angiography can be cited.

[0074] 6. Manufacturing method of elongated medical devices

[0075] The elongated medical devices 1, 2, and 3 of this embodiment can be manufactured, for example, by preparing an elongated body 10 and sequentially layering a base layer 30 or an adhesive layer and a swelling coating 20 on at least a portion of the surface of the elongated body 10 as desired.

[0076] There is no particular limitation on the method of separately preparing the first part 21 and the second part 22 (and then the third part 23) of the swelling coating 20. For example, it can be formed by preparing coatings containing the materials of these parts separately and applying them separately to the surface of the strip 10 (or the base layer 30).

[0077] As described above, the thickness and degree of swelling of the first part 21 and the second part 22 (and then the third part 23) are different, but these differences can be generated by changing the crosslinking density of the resins that make up each part.

[0078] For example, when forming a swellable coating 20 using a coating made by mixing a hydrophilic polymer and a crosslinking agent in a solvent, increasing the amount of crosslinking agent relative to the hydrophilic polymer increases the number of crosslinking points, resulting in a reduction in the degree of swelling and a thinner thickness during swelling. Conversely, decreasing the amount of crosslinking agent relative to the hydrophilic polymer reduces the number of crosslinking points, resulting in an increase in the degree of swelling and a thicker thickness during swelling.

[0079] Therefore, in the coatings used to form the first part 21 and the second part 22, the same amount of hydrophilic polymer is added. On the other hand, the amount of crosslinking agent added is reduced in the coating used to form the first part 21, and the amount of crosslinking agent added is increased in the coating used to form the second part 22. As a result, the crosslinking density of the first part 21 is reduced compared to the second part 22. As a result, the swelling degree of the first part 21 can be formed to be greater and the thickness formed during swelling can be thicker.

[0080] The amount of the crosslinking agent can also be adjusted by adjusting the swelling (absorption) of the strip 10 (or the base layer 30) relative to the solvent.

[0081] For example, by using a resin that readily swells relative to the solvent of the aforementioned coating to form the portion of the elongated body 10 for forming the first portion 21 (first elongated body component), the crosslinking agent can be transferred from the coating applied thereto along with the solvent into the resin, thereby reducing the amount of crosslinking agent in the first portion 21. On the other hand, by using a resin that is difficult to swell relative to the solvent of the aforementioned coating to form the portion for forming the second portion 22 (second elongated body component), the aforementioned transfer of the crosslinking agent can be suppressed, thereby reducing the amount of crosslinking agent in the second portion 22.

[0082] From the viewpoint of easier manufacturing, the elongated medical devices 1, 2, and 3 of this embodiment are preferably manufactured by the method described above, which utilizes the adjustment of the amount of crosslinking agent by the elongated body 10. As a preferred example of such a manufacturing method, a manufacturing method including the following steps can be cited: a step of preparing the elongated body formed by directly or indirectly connecting a first elongated body component I and a second elongated body component II, wherein the first elongated body component I is made of a first resin I, and the second elongated body component II is disposed on the base end side of the first elongated body component I and is made of a second resin II with a swelling degree relative to the first solvent A that is smaller than that of the first resin I; and a coating step of applying a coating containing a crosslinking agent and the first solvent A to at least a portion of the surfaces of the first elongated body component I and the second elongated body component II.

[0083] Moreover, in the above manufacturing method, one preferred approach is to form a swelling coating by applying a coating containing a hydrophilic polymer, a crosslinking agent, and the first solvent A to at least a portion of the surfaces of the first elongated component I and the second elongated component II during the coating process.

[0084] In addition, for the elongated medical device 2 having a base layer 30, the crosslinking dosage in the swelling coating 20 can be adjusted by adding a crosslinking agent to the coating used to form the base layer 30 and transferring the crosslinking agent to the coating of the swelling coating 20.

[0085] In this case, the portion of the strip 10 used to form the first part 21 is formed of a resin that swells easily with respect to the solvent, while the portion used to form the second part 22 is formed of a resin that does not swell easily with respect to the solvent. As a result, the crosslinking agent used in the coating used to form the base layer 30 is transferred to these resins. Due to the difference in the amount of transfer at this time, the amount of crosslinking agent in the first part 21 and the second part 22 formed on the base layer 30 is different, resulting in a difference in crosslinking density.

[0086] As a preferred example of a manufacturing method for a strip-shaped medical device 2 having a base layer 30, a manufacturing method including the following steps can be described: a step of preparing the strip formed by directly or indirectly connecting a first strip component I and a second strip component II, wherein the first strip component I is made of a first resin I, and the second strip component II is disposed on the base end side of the first strip component I and is made of a second resin II having a swelling degree relative to the first solvent A that is smaller than that of the first resin I; a step of forming a base layer by applying a coating containing a base polymer, a crosslinking agent and the first solvent A to at least a portion of the surfaces of the first strip component I and the second strip component II; and a step of forming a swelling coating by applying a coating containing a hydrophilic polymer and a second solvent B to at least a portion of the surface of the base layer opposite to the strip.

[0087] Furthermore, for a strip-shaped medical device with an adhesive layer, a crosslinking agent can be added to the coating used to form the adhesive layer, similar to the strip-shaped medical device 2 with a base layer 30, so that the crosslinking agent is transferred to the coating of the swelling coating 20, thereby adjusting the crosslinking dosage in the swelling coating 20.

[0088] As a preferred example of a manufacturing method for a strip-shaped medical device having an adhesive layer, a manufacturing method including the following steps can be cited: a step of preparing a strip body formed by directly or indirectly connecting a first strip body component I and a second strip body component II, wherein the first strip body component I is made of a first resin I, and the second strip body component II is disposed on the base end side of the first strip body component I and is made of a second resin II having a swelling degree relative to a first solvent A that is smaller than that of the first resin I; a step of forming an adhesive layer by applying a coating containing a crosslinking agent and the first solvent A to at least a portion of the surfaces of the first strip body component I and the second strip body component II; and a step of forming a swelling coating by applying a coating containing a hydrophilic polymer and a second solvent B to at least a portion of the side of the adhesive layer opposite to the strip body.

[0089] It should be noted that the coatings used to form the swelling coating 20, the coatings used to form the base layer 30, and the coatings used to form the adhesive layer can be applied using conventional methods.

[0090] The embodiments described above are provided for ease of understanding of the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments also cover all design modifications or equivalents that fall within the technical scope of the present invention.

[0091] Example

[0092] The present invention will now be described in more detail through examples, etc., but the scope of the present invention is not limited to these examples, etc.

[0093] [Experimental Example 1]

[0094] (1) Confirmation of swelling property

[0095] A resin board of ether-based polyurethane elastomer was cut into dimensions of 10 mm in length, 10 mm in width, and 0.1 mm in thickness to serve as the first resin board. This first resin board was then impregnated overnight in propylene glycol methyl ether acetate (PGMEA) at 23°C, resulting in an increase in both longitudinal and transverse lengths of 1.4 times.

[0096] In addition, a polyamide elastomer resin sheet was cut into dimensions of 10 mm in length, 10 mm in width, and 0.1 mm in thickness to serve as a second resin sheet. This second resin sheet was then immersed in PGMEA overnight at 23°C, and no swelling was observed.

[0097] (2) Sample preparation

[0098] A base coat coating is prepared by mixing 10.58% by weight of a hydrophobic acrylic polyol resin and 3.63% by weight of hexamethylene diisocyanate as a crosslinking agent in 85.79% by weight of PGMEA as a solvent.

[0099] Alternatively, a coating for swelling coatings is prepared by dissolving 10% by mass of a water-soluble hydroxyl-containing acrylic resin in a mixed solvent of 90% by mass of water and ethanol.

[0100] Next, the base layer coating prepared as described above is applied to the resin tube made of the above-mentioned ether-based polyurethane elastomer resin, and then heated at 60°C for 30 minutes to dry it, forming a base layer with a thickness of 4 μm.

[0101] Then, the swelling coating material prepared as described above is applied to the formed substrate layer, and it is heated at 70°C for 90 minutes to dry it, forming a swelling coating with a thickness of 1 μm.

[0102] Thus, a first sample was obtained by sequentially stacking a base layer and a swelling coating on a resin tube made of ether-based polyurethane elastomer resin.

[0103] In addition, except that the resin tube made of ether-based polyurethane elastomer resin was changed to a resin tube made of the aforementioned polyamide elastomer resin, a base layer and a swelling coating were formed in the same manner as the first sample. Thus, a second sample was obtained by sequentially layering a base layer and a swelling coating on a resin tube made of polyamide elastomer resin.

[0104] [Experimental Example 1] (Determination of crosslinking dose on the surface of the substrate layer)

[0105] As described above, during the preparation of the first and second samples, immediately after the formation of the substrate layer, the crosslinking dose on the surface of the substrate layer was measured using Fourier transform infrared spectroscopy (FT-IR). The results showed that the crosslinking dose of the second sample was 1.2 times that of the first sample.

[0106] [Experimental Example 2] (Determination of the thickness of the swollen coating after swelling)

[0107] For the first and second samples prepared, the thickness of the swollen coating after swelling was measured. Specifically, the first and second samples were immersed in water at 27°C for 120 minutes, thereby allowing each swollen coating to fully swell. Then, the thickness of the swollen coating after swelling was measured.

[0108] As a result, in the first sample, the swollen coating had a thickness of 34 μm. In contrast, in the second sample, the swollen coating had a thickness of 12 μm. That is, the swollen coating of the first sample was approximately three times thicker than that of the second sample.

[0109] In addition, based on the following formula (1), the swelling degree of the swelling coating was calculated for the first sample and the second sample respectively. The result was 34 in the first sample and 12 in the second sample.

[0110] Swelling degree = (thickness after swelling) ÷ (thickness before swelling) ... (1)

[0111] The results of the above experiments show that by using different materials for the resin tube and changing the crosslinking dosage in the base layer, the thickness and degree of swelling of the swollen coating can be changed.

[0112] Therefore, it can be seen that by forming the first part in the same way as the first sample and the second part in the same way as the second sample, the elongated medical device of this embodiment can be manufactured.

[0113] Industrial utilization potential

[0114] The elongated medical device of the present invention is suitable, for example, as a guidewire, catheter, etc.

[0115] Symbol Explanation

[0116] 1, 2, 3—elongated medical devices; 10—elongated body; 20—swellable coating; 21—first part; 22—second part; 23—third part; 30—base layer.

Claims

1. A strip-shaped medical device comprising a strip extending from a front end to a base end and a swelling coating disposed on at least a portion of the surface of the strip, characterized in that, The swelling coating has a first portion and a second portion disposed at a position closer to the base end than the first portion. The thickness of the first portion of the swelling coating is greater than the thickness of the second portion after the elongated medical device is immersed in water at 37°C for 120 minutes to swell. The degree of swelling of the second part of the swellable coating, as defined by equation (1), is smaller than the degree of swelling of the first part of the swellable coating, as defined by equation (1): Swelling degree = (thickness after swelling) ÷ (thickness before swelling) ... (1).

2. The elongated medical device according to claim 1, characterized in that, The swelling coating includes a third portion disposed at a position closer to the base end than the second portion. The second part, after swelling, is thicker than the third part. The swelling degree of the swelling coating in the third part, as defined by formula (1), is smaller than that of the swelling degree of the swelling coating in the second part, as defined by formula (1).

3. A method for manufacturing an elongated medical device, the elongated medical device having an elongated body extending from a front end to a base end, the method for manufacturing the elongated medical device being characterized by comprising: The process of preparing the elongated body formed by directly or indirectly connecting the first elongated body component (I) and the second elongated body component (II), wherein the first elongated body component (I) is made of a first resin (I), and the second elongated body component (II) is disposed on the base end side of the first elongated body component (I) and is made of a second resin (II) with a swelling degree relative to the first solvent (A) that is smaller than that of the first resin (I); as well as A coating process of applying a coating containing a crosslinking agent and the first solvent (A) to at least a portion of the surfaces of the first elongated component (I) and the second elongated component (II).

4. The method for manufacturing the elongated medical device according to claim 3, characterized in that, In the coating process, a swelling coating is formed by applying a coating containing a hydrophilic polymer, a crosslinking agent and the first solvent (A) to at least a portion of the surface of the first elongated component (I) and the second elongated component (II).

5. The method for manufacturing the elongated medical device according to claim 3, characterized in that, In the coating process, a base layer is formed by applying a coating containing a base polymer, a crosslinking agent, and the first solvent (A) to at least a portion of the surfaces of the first elongated component (I) and the second elongated component (II). Following the coating process, the process further includes forming a swelling coating by applying a coating containing a hydrophilic polymer and a second solvent (B) to at least a portion of the side of the substrate opposite to the elongated body.

6. The method for manufacturing the elongated medical device according to claim 3, characterized in that, In the coating process, an adhesive layer is formed by applying a coating containing a crosslinking agent and the first solvent (A) to at least a portion of the surfaces of the first elongated component (I) and the second elongated component (II). Following the coating process, the process further includes forming a swelling coating by applying a coating containing a hydrophilic polymer and a second solvent (B) to at least a portion of the side of the adhesive layer opposite to the strip.

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