catheter

Abstract

To provide a catheter that achieves a small diameter and superior antifouling properties while offering excellent sliding and bending properties.SOLUTION: A catheter according to the present invention is provided with a tubular member and a covering layer that covers at least a portion of the surface of the tubular member, wherein the tubular member contains one selected from the group consisting of polyamide resin, polyurethane resin, polyolefin resin, polyester resin, and chlorinated polyethylene resin, and the covering layer contains an organic polysilazane.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Tubular medical devices commonly called catheters are capable of providing necessary treatment without making large incisions in the body, and also place a light burden on patients and doctors, making them an indispensable medical device in hospitals and other medical institutions.

[0003] Because such catheters are inserted into a predetermined location in the body, for example, via a blood vessel, they are required to be small in diameter, bendable, and have excellent sliding properties. One known method for improving sliding properties is to provide a hydrophilic coating on the tip to form a hydrophilic layer (see, for example, Patent Document 1). However, conventional hydrophilic coatings are not optimal from the perspective of antifouling properties. Meanwhile, polytetrafluoroethylene (PTFE) is known as a chemical substance with antifouling properties, and one method for obtaining an antifouling catheter is to coat the tip with PTFE. However, PTFE coatings must be formed via a binder (adhesive), which reduces bending properties and increases the diameter. Furthermore, PTFE coatings require a baking process, which is problematic from the perspective of manufacturing efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 7-507599 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned conventional problems, and its object is to provide a catheter that has excellent sliding properties and bendability, is small in diameter, and has excellent anti-fouling properties. [Means for solving the problem]

[0006] The catheter of the present invention comprises a tubular member and a coating layer covering at least a portion of the surface of the tubular member, the coating layer comprising an organic polysilazane. In one embodiment, the organic polysilazane includes a constitutional unit represented by general formula (1). [ka] In formula (1), R 1 , R 2 and R 3 each independently represents a hydrogen atom, an unsubstituted or substituted alkyl group, or an unsubstituted or substituted alkenyl group; R 1 , R 2 , R 3 is other than a hydrogen atom, and n is a positive integer. In one embodiment, the length of the portion where the coating layer is formed is 0.1 mm to 100 mm. In one embodiment, the coating layer has a thickness of 50 μm or less. In one embodiment, the coating layer is laminated directly onto the tubular member. In one embodiment, the coating layer is formed on a part of the tubular member, and a hydrophilic layer is formed on the part where the coating layer is not formed. [Effects of the Invention]

[0007] According to the present invention, by forming a coating layer containing an organic polysilazane, it is possible to provide a catheter that has excellent sliding properties, a small diameter, and excellent bendability. The catheter of the present invention is also advantageous in that it has excellent antifouling properties, for example, in that it prevents adhesion of adhesives discharged from the catheter. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a catheter according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view of the catheter shown in FIG. 1 taken along line IIa. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Overview of catheters Fig. 1 is a schematic diagram of a catheter according to one embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of a catheter according to one embodiment of the present invention taken along line IIa. A catheter 100 according to this embodiment includes a tubular member 10 and a coating layer 20 that covers at least a portion of the tubular member 10. Generally, the tubular member is thin, elongated, and hollow. The coating layer 20 contains an organic polysilazane.

[0010] The tubular member 10 has a base end (proximal end) 11 and a tip (distal end) 12. In one embodiment, the coating layer 20 is formed on the tip portion of the tubular member 10. In this specification, the tip means the end that reaches the treatment area in the body cavity, and the base end means the end opposite to the tip.

[0011] The coating layer 20 may be formed on the outer surface of the tubular member 10 as in the illustrated example, on the inner surface of the tubular member, or on both the outer and inner surfaces of the tubular member.

[0012] In the present invention, by providing a coating layer containing organic polysilazane, a catheter having excellent slidability can be obtained. In addition, the portion of the catheter having the coating layer is advantageously excellent in bendability.

[0013] In one embodiment, the coating layer is laminated directly onto the tubular member. The coating layer containing organic polysilazane can be laminated directly onto the tubular member without the use of a binder (adhesive, primer layer, etc.). By directly forming the coating layer, a catheter with a small diameter can be obtained. Furthermore, since a layer that increases rigidity can be omitted, a catheter with excellent flexibility can be obtained.

[0014] Furthermore, by forming a coating layer, a catheter with excellent antifouling properties can be obtained. For example, it is possible to prevent materials injected into the catheter from adhering to the surface of the catheter. In particular, when a coating layer is formed on the tip of a tubular member, materials expelled from the catheter are prevented from adhering to the catheter. The catheter of the present invention having such characteristics is particularly useful when injecting adhesives.

[0015] In one embodiment, the coating layer is formed on a portion of the surface of the tubular member, and a hydrophilic layer is formed on the portion where the coating layer is not formed.

[0016] The catheter may further include other known components, such as various ports, various connectors, operating components, a mandrel, a ball tip, a marker, a balloon, etc. These components are well known in the art, and therefore will not be described in detail.

[0017] The catheter is not particularly limited, and examples thereof include guiding catheters, angiography catheters, various balloon catheters for PTCA, PTA, IABP, etc., ultrasound catheters, atherectomy catheters, endoscopic catheters, indwelling catheters, drug solution administration catheters, microcatheters, etc.

[0018] B. Tubular members As described above, the tubular member is a long member having a small diameter and a hollow interior. The tubular member may be branched.

[0019] The length of the tubular member can be any appropriate length depending on the application, and is, for example, 20 cm to 200 cm.

[0020] The thickness of the tubular member can be any appropriate thickness depending on the application, and is, for example, 0.01 mm to 0.8 mm, and preferably 0.05 mm to 0.5 mm.

[0021] The cross-sectional shape of the tubular member may be any appropriate shape. Preferably, it is a substantially circular shape. The inner diameter of the tubular member may be any appropriate inner diameter depending on the application. The inner diameter of the tubular member is, for example, 0.3 mm to 4 mm.

[0022] The tubular member 10 may have a single-layer structure (FIG. 2) or a multi-layer structure. Any appropriate material may be used as the material for the tubular member as long as the effects of the present invention can be obtained. In one embodiment, the tubular member is made of a polymeric material. A material that can exhibit flexibility is preferred as the polymeric material. Examples of polymeric materials include styrene-based resins, acrylic-based resins, polyolefin-based resins, polyurethane-based resins, polyester-based resins, polyamide-based resins, epoxy-based resins, polycarbonate-based resins, polybutadiene-based resins, transisoprene-based resins, fluororubber-based resins, and chlorinated polyethylene-based resins. These polymeric materials may be used alone or in combination of two or more. When the tubular member has a multi-layer structure, the tubular member may have multiple layers formed from different polymeric materials, or multiple layers formed from the same polymeric material. Furthermore, the tubular member may be made of different polymeric materials for each longitudinal segment. In one embodiment, a polyamide-based resin is used as the polymeric material from the viewpoint of affinity with the coating layer. If such a polymer material is used, a coating layer can be formed with good adhesion.

[0023] The tubular member may be subjected to any appropriate treatment, such as reinforcement treatment with thin metal wires, surface modification treatment such as plasma treatment or corona treatment, or coupling treatment.

[0024] C. Covering layer As described above, the coating layer is made of an organic polysilazane, which is a polymer having —Si—N— as a basic structural unit and having an organic group in the structural unit.

[0025] An example of the organic polysilazane is a polymer containing a structural unit represented by general formula (1). [ka] In formula (1), R 1 , R 2 and R 3 each independently represents a hydrogen atom, an unsubstituted or substituted alkyl group, or an unsubstituted or substituted alkenyl group; R 1 , R 2 , R 3 is a positive integer.

[0026] Examples of the alkyl group of the unsubstituted or substituted alkyl group include alkyl groups having 1 to 10 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-heptyl group, and n-octyl group.

[0027] Examples of the alkenyl group of the unsubstituted or substituted alkenyl group include alkenyl groups having 2 to 10 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, and 3-butenyl.

[0028] Examples of the substituent on the alkyl group and alkenyl group include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkoxysilyl group, a hydroxyl group, a thiol group, an epoxy group, a glycidoxy group, a (meth)acryloyloxy group, a phenyl group, a 4-methylphenyl group, and a 4-chlorophenyl group.

[0029] In one embodiment, the organic polysilazane contains a constitutional unit represented by general formula (2-1), a constitutional unit represented by general formula (2-2), and a constitutional unit represented by general formula (2-3). [ka] In formula (2-1), R 1-2 is an unsubstituted or substituted alkyl group. In formula (2-2), R 2-1 and R 2-2 are each independently an unsubstituted or substituted alkyl group. In formula (2-3), R 3-1 R is a hydrogen atom or an unsubstituted or substituted alkyl group. 3-2 is an unsubstituted or substituted alkyl group. 3-3 is an unsubstituted or substituted alkyl group, and may contain an alkoxysilyl group (R is 1 to 20) represented by -Si(OR)3 as a substituent to obtain good adhesion. These functional groups can be appropriately selected according to the metal material that constitutes the core material.

[0030] In the formulas (2-1) to (2-3), x, y, and z are positive integers, and the ratio of x, y, and z is (5 to 90):(5 to 90):(5 to 90).

[0031] The organic polysilazane may be a random copolymer or a block copolymer.

[0032] The number average molecular weight of the organic polysilazane is preferably 500 to 4500. Within this range, a catheter with excellent slidability and bendability can be obtained.

[0033] The thickness of the coating layer is preferably 50 μm or less, more preferably 20 μm or less, and even more preferably 1 μm to 10 μm. Within this range, the increase in rigidity due to the coating layer is small, and a catheter with excellent flexibility and bendability can be obtained. From the viewpoint of flexibility and bendability, the thinner the thickness of the coating layer, the better.

[0034] The length of the portion where the coating layer is formed is preferably 0.1 mm to 100 mm, more preferably 1 mm to 80 mm. Within this range, a catheter can be obtained that is preferably prevented from adhesion of the discharged adhesive. In the portion where the coating layer is formed, it is preferable that the coating layer is formed over the entire circumference of the tubular member. In addition, in the portion where the coating layer is not formed, a hydrophilic layer may be formed on the surface of the coating layer. Details of the hydrophilic layer will be described later.

[0035] The coating layer can be formed by any suitable method. In one embodiment, the coating layer is formed by applying a coating layer-forming composition containing an organic polysilazane to a predetermined region of the tubular member. The coating layer-forming composition can be prepared by dissolving the organic polysilazane in a predetermined solvent.

[0036] Any suitable solvent can be used as long as it can dissolve the organic polysilazane, such as propane, butane, isobutane, pentane, 2-methylbutane, neopentane, cyclopentane, hexane, 2-methylpentane, 3-methylpentane, heptane, 2-methylhexane, 3-methylhexane, cyclohexane, octane, isooctane, nonane, isononane, and decane.

[0037] The concentration of the organic polysilazane in the coating layer-forming composition is preferably 5% by weight to 40% by weight, and within this range, a coating layer of a desirable thickness can be formed with good uniformity.

[0038] The viscosity of the composition for forming a coating layer is not particularly limited as long as it is a viscosity that allows coating. By appropriately adjusting the viscosity of the composition for forming a coating layer, a good coating layer can be formed.

[0039] The coating layer-forming composition may be applied by any suitable method, typically by dip coating, spray coating, flow coating, or the like.

[0040] Preferably, after the coating layer-forming composition is applied to the tubular member, a heat treatment is carried out, which volatilizes the solvent and hardens the coating layer, forming a coating layer that adheres closely to the tubular member.

[0041] The coating layer formed as described above can adhere to the tubular member by, for example, a dehydration reaction between the OH groups of the tubular member and the SiH groups of the organic polysilazane; a deammonia reaction between the OH groups of the tubular member and the NH groups of the organic polysilazane; or, after the SiN groups of the organic polysilazane are hydrolyzed (for example, by moisture in the atmosphere), a dehydration reaction between the OH groups of the tubular member and the silanol groups generated by hydrolysis.

[0042] When the coating layer is formed by applying the above-mentioned coating layer-forming composition to a SUS304 plate, the contact angle of the coating layer with pure water is preferably 100° to 120°, more preferably 105° to 115°. If a coating layer is formed using a coating layer-forming composition capable of forming such a coating layer, a catheter with excellent slidability can be obtained.

[0043] When the coating layer is formed by applying the above-mentioned coating layer-forming composition to a SUS304 plate, the coating layer preferably has a static friction coefficient of 0.05 to 0.15. If a coating layer is formed using a coating layer-forming composition capable of forming such a coating layer, a catheter with excellent slidability can be obtained.

[0044] When the coating layer is formed by applying the above-mentioned composition for forming a coating layer to a SUS304 plate, the coating layer preferably has a dynamic friction coefficient of 0.01 to 0.12. If a coating layer is formed using a composition for forming a coating layer capable of forming such a coating layer, a catheter with excellent slidability can be obtained.

[0045] D. Hydrophilic layer In one embodiment, as described above, a hydrophilic layer is formed on the surface of the core material in the portion of the tubular member where no coating layer is formed (the outer surface and / or the inner surface). By forming a hydrophilic layer, a catheter with excellent slidability within a body cavity can be obtained.

[0046] The hydrophilic layer can be formed by coating the tubular member with any suitable hydrophilic material, such as polymeric materials based on cellulose, polyethylene oxide, maleic anhydride, and acrylamide.

[0047] The length of the portion where the hydrophilic layer is formed is preferably 100 mm to 1500 mm, more preferably 200 mm to 1200 mm, and is preferably 15% to 92% of the length of the tubular member, more preferably 50% to 90%, and even more preferably 60% to 85%. [Example]

[0048] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are by weight unless otherwise specified.

[0049] [Example 1] The tip of a tubular member (thickness: 0.09 mm, inner diameter: 0.4 mm) made of polyamide resin was immersed in a coating layer-forming composition A (organic polysilazane concentration: approximately 20 wt %) prepared by dissolving an organic polysilazane having structural units represented by the following structural formulas (3-1) to (3-3) in a hydrocarbon solvent. The coating layer-forming composition A was then applied to the surface of the tubular member (length: 60 mm). The tubular member was then left to stand at room temperature for at least 72 hours, forming a coating layer approximately 2 μm thick on the surface (outside and inside) of the tubular member, thereby producing evaluation sample (1) intended for use as a catheter. Evaluation sample (1) was evaluated for antifouling properties, adhesive resistance, and bendability using the following evaluation methods. The results are shown in Table 1. [ka]

[0050] <Stain resistance> The antifouling properties of the coating layer of the evaluation sample (1) obtained in Example 1 were evaluated by the following method. The catheter was immersed in oil-based ink (vermilion oil, manufactured by Shachihata Co., Ltd.) and the ink repellency was checked. Regarding repellency, if the catheter surface was exposed as a result of the ink being repelled after 5 minutes of immersion in the oil-based ink, it was evaluated as ◯, and if the catheter surface was not exposed, it was evaluated as ×. After the immersion, it was confirmed whether the ink could be wiped off with a paper towel or the like (for example, Kuraray Kuraclean Wiper). <Anti-adhesive resistance> The evaluation sample (1) obtained in Example 1 was evaluated for adhesive resistance by the following method. A 1:1 mixture of adhesive (Aron Alpha, manufactured by Toagosei) and oil-based contrast agent (Lipiodol, manufactured by Guerbet Japan) and simulated blood were injected at a 4:1 ratio into a 30mm long hard resin pipe made of ABS resin or other material, and the tip of the catheter (30mm) was inserted into the pipe. After the liquid inside the pipe was thoroughly mixed, the catheter was left inserted until it hardened. After hardening, a specified impact load was repeatedly applied to the part of the catheter that was not inserted into the pipe until the catheter came out of the pipe, and the number of impact loads applied until the catheter came out of the pipe was counted. The anti-adhesive resistance was evaluated based on the average number of times an impact load was applied until the catheter came out of the pipe. <Bendability> The bending property of the evaluation sample (1) obtained in Example 1 was evaluated by the following method. The evaluation sample (1) was folded at a random location once at approximately 180° so as to fold in half. After leaving it in the folded state, the coating condition of the folded portion was magnified with a commercially available microscope and visually observed for cracks or peeling of the coating.

[0051] In addition, the coating layer-forming composition A used in Example 1 was applied to a SUS plate (commercially available) to form a coating similar to that for evaluation sample (1), thereby obtaining evaluation sample (2). The contact angle (pure water) and friction coefficient of the obtained evaluation sample (2) were measured using the following evaluation methods. The results are shown in Table 2. <Contact angle (pure water)> The contact angle of pure water (liquid volume 2 μL) was measured using a product called "DropMaster500" manufactured by Kyowa Interface Science Co., Ltd. <Coefficient of friction> The static and dynamic friction coefficients of the coating layer were measured under the following conditions using a "Surface Property Measuring Instrument Tribostation TYPE:32" manufactured by Shinto Chemical Co., Ltd. (Friction coefficient measurement conditions) Load: 100g Indenter: Flat indenter (10mm x 10mm) Travel speed: 30mm / min (static friction coefficient), 600mm / min (dynamic friction coefficient)

[0052] [Comparative Example 1] A commercially available catheter having a hydrophilic coating layer was obtained and evaluated for antifouling properties, anti-adhesive resistance, and bendability in the same manner as in evaluation sample (1). The results are shown in Table 1.

[0053] [Table 1]

[0054] [Table 2]

[0055] [result] As shown in Table 1, after 5 minutes of immersion in oil-based ink, the catheter surface of evaluation sample (1) obtained in Example 1 was exposed, the ink could be wiped off, and the catheter had good stain resistance. The average number of impacts required before the catheter was removed from the pipe was 6.6, demonstrating excellent anti-adhesive resistance. In contrast, as shown in Table 1, after 5 minutes of immersion in oil-based ink, the catheter surface of Comparative Example 1 was not exposed, the ink could not be wiped off, and the average number of impacts required before the catheter was removed from the pipe was 21.2. Furthermore, there was no difference in bendability between Example 1 and Comparative Example 1, and evaluation sample (1) obtained in Example 1 was observed to have bendability equivalent to that of Comparative Example 1. The coating layer-forming composition A of Example 1 had excellent water repellency with a contact angle (pure water) of 108° for evaluation sample (2), and had excellent sliding properties with a static friction coefficient of 0.095 and a dynamic friction coefficient of 0.057. This indicates that the catheter obtained from the coating layer-forming composition A of Example 1 has excellent insertability into a body cavity. By forming a coating layer using such a composition for forming a coating layer, a catheter having excellent antifouling properties, anti-adhesive resistance, and bending properties can be obtained. The catheter of the present invention has the advantage that it has excellent antifouling properties and anti-adhesive resistance, as shown in Example 1, while having the same slidability and bending properties as a catheter coated with a hydrophilic coating. [Explanation of symbols]

[0056] 10 Tubular member 20 Covering layer 100 catheters

Claims

1. a tubular member and a coating layer covering at least a portion of the surface of the tubular member; the tubular member contains one resin selected from the group consisting of polyamide-based resin, polyurethane-based resin, polyolefin-based resin, polyester-based resin, and chlorinated polyethylene-based resin; the coating layer is made of organic polysilazane, The coating layer is formed on the distal end portion of the tubular member. catheter.

2. A catheter as described in claim 1, in which a hydrophilic layer is formed in the area where the coating layer is not formed.

3. A method for injecting adhesive, The catheter of claim 1 , wherein the coating layer is formed on an outer surface of the tubular member.

4. The catheter according to any one of claims 1 to 3, wherein the organic polysilazane contains a structural unit represented by general formula (1): 【Chemistry 1】 In formula (1), R １ , R ２ and R ３ each independently represents a hydrogen atom, an unsubstituted or substituted alkyl group, or an unsubstituted or substituted alkenyl group; R １ , R ２ , R ３ is other than a hydrogen atom, and n is a positive integer.

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