A medical catheter and a method of manufacturing the same

Abstract

The application discloses a medical catheter and a preparation method thereof, and belongs to the field of medical catheter technology. The medical catheter comprises an inner layer pipe material composed of polytetrafluoroethylene material, a coating layer composed of nylon elastomer material covering the outer surface of the inner layer pipe material, a metal braided layer arranged on the outside of the coating layer, a middle layer composed of nylon elastomer material covering the outside of the metal braided layer, and an outer layer composed of nylon material covering the outside of the middle layer. The preparation method comprises the following steps: preparing a solution, dissolving the nylon elastomer material in an organic solvent to obtain a uniform nylon elastomer solution; dip coating, dipping the inner layer pipe material composed of polytetrafluoroethylene material in a container containing the nylon elastomer solution so that the surface of the inner layer pipe material is attached with a solution layer; and drying, heating the inner layer pipe material after dip coating in a sintering furnace to volatilize the solvent and form a solid coating layer composed of nylon elastomer material on the surface of the inner layer pipe material. The medical catheter has the advantages that the interlayer bonding force can be enhanced, and the burst pressure resistance of the medical catheter can be improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a medical catheter and its preparation method. Background Technology

[0002] Microcatheters and sheaths are commonly used medical devices in interventional procedures, typically composed of multi-layered composite materials. In current technology, the inner layer of the catheter is often made of polytetrafluoroethylene (PTFE) due to its excellent lubrication properties, facilitating the passage of drugs or instruments. The outer PTFE layer usually has a metal braided layer, followed by an outer layer of nylon elastomer (such as Pebax) and nylon material. However, due to PTFE's low surface energy and high melting point, it exhibits poor adhesion to other materials, especially in the mesh area of ​​the metal braided layer, where the bond between PTFE and Pebax is weak. This makes the catheter prone to rupture or leakage under high pressure. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a medical catheter and its preparation method, which can enhance the interlayer bonding force and improve the burst pressure resistance of the medical catheter.

[0004] In a first aspect, the medical catheter according to an embodiment of the present invention comprises: The inner tubing is made of polytetrafluoroethylene (PTFE). The coating, covering the outer surface of the inner tubing, is made of nylon elastomer material; A metal braided layer is disposed on the outer side of the coating; The intermediate layer, made of nylon elastomer material, covers the outside of the metal braided layer; The outer layer, made of nylon material, covers the outside of the middle layer.

[0005] The medical catheter according to embodiments of the present invention has at least the following beneficial effects: by introducing a coating made of nylon elastomer material between the inner tubing (polytetrafluoroethylene PTFE tubing) and the outer metal braided layer, the coating is identical or compatible with the subsequent nylon elastomer intermediate layer material, and can achieve good fusion during the hot melt processing, thereby significantly improving the bonding strength between the layers; this structure effectively avoids the problem of reduced pressure resistance caused by poor interlayer bonding in the metal braided mesh area of ​​traditional catheters, enabling the medical catheter to maintain structural integrity and not rupture or leak under high pressure environment, significantly improving the explosion-proof pressure resistance and safety of the medical catheter.

[0006] According to some embodiments of the present invention, the coating and the intermediate layer are made of the same or compatible nylon elastomer material and are fused together after hot-melt processing.

[0007] According to some embodiments of the present invention, the nylon elastomer material is Pebax material.

[0008] According to some embodiments of the present invention, the Pebax material is Pebax 4033.

[0009] According to some embodiments of the invention, the thickness of the coating is from 0.0001 inches to 0.01 inches. Secondly, a method for preparing a medical catheter according to an embodiment of the present invention includes the following steps: Solution preparation: Dissolve the nylon elastomer material in an organic solvent to obtain a homogeneous nylon elastomer solution; Dip coating: The inner tube made of polytetrafluoroethylene is immersed in a container containing the nylon elastomer solution, so that a solution layer is attached to its surface; Drying: The dip-coated inner tube is heated in a sintering furnace to evaporate the solvent and form a solid coating made of nylon elastomer material on the surface of the inner tube.

[0010] The method for preparing medical catheters according to embodiments of the present invention has at least the following beneficial effects: by impregnating the surface of the polytetrafluoroethylene inner tube with a nylon elastomer solution and drying it to form a film, a uniform and stable coating is formed; the method is simple and easy to carry out continuous production, enabling the subsequent metal braided layer and the nylon elastomer intermediate layer to achieve thermal fusion under the same material system, effectively solving the technical problem that PTFE is difficult to directly bond with other materials, thus providing a reliable technical path for preparing high-performance, high-pressure-resistant medical catheters.

[0011] According to some embodiments of the present invention, the dip coating process adopts a continuous traction method, wherein the inner tube passes through the container and the sintering furnace at a set traction speed, wherein the traction speed is 1 m / min to 10 m / min.

[0012] According to some embodiments of the present invention, the sintering furnace is provided with a plurality of temperature control zones, and the temperature of each temperature control zone is independently controlled between 100°C and 200°C.

[0013] According to some embodiments of the present invention, the thickness of the coating is controlled by adjusting the concentration of the nylon elastomer solution and / or the traction speed.

[0014] According to some embodiments of the present invention, the dried inner tubing further includes a cleaning step for removing residual organic solvents from the surface.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a medical catheter according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a medical catheter in the prior art; Figure 3 This is a schematic diagram of the structure of the dip coating production line equipment according to an embodiment of the present invention; Figure 4 This is a flowchart of a medical catheter preparation method according to an embodiment of the present invention; Figure 5 These are comparative diagrams of embodiments of the present invention; Figure 6 This is another comparative diagram of an embodiment of the present invention.

[0018] The attached diagram is labeled as follows: Inner tube 100; Coating 200; Metal braided layer 300; Intermediate layer 400; Outer layer 500; Container 600; Sintering furnace 610; Alcohol tank 620; Pure water tank 630; Receiving platform 640. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0021] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" and "second" are mentioned, this is only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation, connection, and linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] The following describes a medical catheter and its preparation method according to an embodiment of the present invention, with reference to the accompanying drawings.

[0024] Firstly, referring to Figures 1-2 The medical catheter of this invention includes: The inner tube 100 is made of polytetrafluoroethylene. Coating 200, covering the outer surface of the inner tube 100, is made of nylon elastomer material; A metal braided layer 300 is disposed on the outside of the coating 200; The intermediate layer 400, made of nylon elastomer material, covers the outside of the metal braided layer 300; The outer layer 500, made of nylon material, covers the outside of the middle layer 400.

[0025] In this embodiment, a coating 200 made of nylon elastomer material is introduced between the inner tube 100 (PTFE tube) and the outer metal braided layer 300. This coating 200 is made of the same or compatible material as the subsequent nylon elastomer intermediate layer 400, and can achieve good fusion during the hot melt processing, thereby significantly improving the bonding strength between the layers. This structure effectively avoids the problem of reduced pressure resistance caused by poor interlayer bonding in the metal braided mesh area of ​​traditional catheters. It enables medical catheters to maintain structural integrity and prevent rupture or leakage under high pressure, significantly improving the explosion-proof pressure resistance and safety of medical catheters.

[0026] According to some embodiments of the present invention, for example, Figure 1 As shown, the coating 200 and the intermediate layer 400 are made of the same or compatible nylon elastomer materials and are fused together after hot-melt processing.

[0027] In this embodiment, the coating 200 and the intermediate layer 400 are made of the same or compatible nylon elastomer materials and are fused together after hot-melt processing. This ensures that the two layers form a molecular-level bond at the interface, eliminating the weak interfacial areas caused by material differences in traditional structures. This makes the stress transmission of the medical catheter more uniform when subjected to high pressure, and significantly improves the interlayer peel strength, thereby further enhancing the overall structural stability and pressure resistance of the catheter.

[0028] According to some embodiments of the present invention, the nylon elastomer material is Pebax material.

[0029] In this embodiment, the nylon elastomer material is Pebax material, which has excellent flexibility, low temperature resistance and processing stability. It has good compatibility with the polytetrafluoroethylene inner tube 100 and the nylon outer layer 500, and can achieve good interlayer fusion during hot melt processing. At the same time, its biocompatibility meets the medical implant-grade standard, providing a reliable guarantee for the safe application of medical catheters in interventional surgery.

[0030] According to some embodiments of the present invention, the Pebax material is Pebax 4033.

[0031] In this embodiment, Pebax 4033 material has suitable hardness and melting temperature, and can form a uniform and stable coating 200 in the dip coating process. It can achieve an ideal fusion effect with the subsequent intermediate layer 400 material during hot melt processing. At the same time, its excellent mechanical properties help to improve the burst pressure resistance of medical catheters. It is a proven and ideal material for the manufacture of medical catheters.

[0032] It should be further noted that the Pebax material used in this application is not limited to Pebax 4033, and other Pebax series models may be used.

[0033] According to some embodiments of the invention, the thickness of coating 200 is 0.0001 inches to 0.01 inches.

[0034] In this embodiment, the above-mentioned thickness range can ensure that the coating 200 plays an effective bonding and transition role between the metal braided layer 300 and the intermediate layer 400, and will not affect the flexibility and patency of the medical catheter due to excessive thickness of the coating 200. It is the optimal process parameter range optimized based on a large number of experiments, which can take into account both the mechanical properties and clinical operation performance of the medical catheter.

[0035] Secondly, referring to Figures 3-4 The method for preparing a medical catheter according to an embodiment of the present invention includes the following steps: S1: Solution preparation: Dissolve the nylon elastomer material in an organic solvent to obtain a homogeneous nylon elastomer solution; S2: Dip coating: The inner tube 100, made of polytetrafluoroethylene material, is immersed in a container 600 containing a nylon elastomer solution, so that a solution layer is attached to its surface. S3: Drying: The inner tube 100 after dipping is heated in a sintering furnace 610 to evaporate the solvent and form a solid coating 200 made of nylon elastomer material on the surface of the inner tube 100.

[0036] In this embodiment, a uniform and stable coating 200 is formed by impregnating the surface of the polytetrafluoroethylene inner tube 100 with a nylon elastomer solution and drying it to form a film. This method is simple and easy to carry out continuous production, which enables the subsequent metal braided layer 300 and the nylon elastomer intermediate layer 400 to achieve thermal fusion under the same material system. This effectively solves the technical problem that PTFE is difficult to bond directly with other materials, thus providing a reliable technical path for the preparation of high-performance, high-pressure-resistant medical catheters.

[0037] According to some embodiments of the present invention, for example, Figure 3 As shown, the dip coating process adopts a continuous traction method. The inner tube 100 passes through the container 600 and the sintering furnace 610 at a set traction speed of 1 m / min to 10 m / min.

[0038] In this embodiment, a continuous traction method is adopted, and the traction speed is controlled within the range of 1 m / min to 10 m / min. This range of process parameters can achieve efficient continuous production while ensuring the uniformity of the coating 200. The traction speed has a good linear relationship with the coating 200 thickness, which makes it easy to accurately control the coating 200 thickness by adjusting the speed, so as to meet the production needs of medical catheters of different specifications.

[0039] According to some embodiments of the present invention, for example, Figure 3 As shown, the sintering furnace 610 is equipped with several temperature control zones, and the temperature of each temperature control zone is independently controlled between 100°C and 200°C.

[0040] In this embodiment, the sintering furnace 610 is equipped with a gradient cooling drying method, which enables the organic solvent in the coating 200 to gradually evaporate, avoiding blistering, cracking or uneven thickness of the coating 200 caused by sudden temperature changes. At the same time, it ensures that the nylon elastomer material is fully melted within a suitable temperature range and forms a good bond with the PTFE inner layer, significantly improving the density and adhesion of the coating 200.

[0041] According to some embodiments of the present invention, the thickness of the coating 200 is controlled by adjusting the concentration of the nylon elastomer solution and / or the traction speed.

[0042] In this embodiment, the thickness of the coating 200 is controlled, which makes the production process highly flexible and designable. It can quickly adjust the process parameters to obtain the ideal coating 200 thickness according to different medical catheter specifications and performance requirements, which significantly improves the adaptability of the product and production efficiency.

[0043] According to some embodiments of the present invention, for example, Figure 3 As shown, the dried inner tube 100 also includes a cleaning step to remove residual organic solvents from the surface.

[0044] In this embodiment, the cleaning step can effectively eliminate the potential impact of residual solvent on the surface of coating 200 on the biosafety of medical catheters, ensuring that the purity and biocompatibility of the final product meet the medical implant-grade standards. At the same time, the cleaning process (such as alcohol bath 620 and pure water bath 630 treatment) will not damage the formed coating 200, ensuring the stability and reliability of product quality.

[0045] In addition, the present invention also has the following embodiments 1-6: Description of the selected raw materials: Solvent: Organic solvent; Solute: Pebax 4033, Manufacturer: Arkema, CAS No.: 9010-95-1; Inner tubing: polytetrafluoroethylene, CAS No.: 9002-84-0.

[0046] According to Embodiment 1 of the present invention, the preparation method of a medical catheter includes the following specific steps: (1) Solution preparation: Weigh an appropriate amount of Pebax 4033 granules into a beaker, add organic solvent, place the beaker in a water bath at an appropriate temperature and heat, and stir with a glass rod until the granules are completely dissolved to obtain a uniform and transparent Pebax solution (concentration of 4%, w / v); (2) Equipment preparation: Start the sintering furnace 610 of the dip coating production line equipment for preheating. The sintering furnace 610 has several temperature control zones from top to bottom. The temperature of each temperature control zone is independently controlled between 100°C and 200°C. (3) Filling the solution: Pour the Pebax solution prepared in step (1) into the dip coating container 600.

[0047] (4) Dip coating: The PTFE inner tube 100 is passed through the dip coating production line equipment. The traction speed is set to 1 m / min. The equipment is started for continuous dip coating. The inner tube 100 passes through the solution tank and sintering furnace 610 in sequence. After the solvent evaporates in the sintering furnace 610, a coating 200 is formed.

[0048] (5) Receiving: The receiving platform 640 at the end of the dip coating production line completes the receiving by laser cutting to obtain PTFE pipes with Pebax coating 200 on the surface. The thickness of the double-sided coating 200 is measured to be 0.0001 inches.

[0049] The difference between Embodiments 2-3 and Embodiment 1 lies in the traction speed during the dip coating process; other steps and parameters are the same as in Embodiment 1. Different coating thicknesses 200 can be obtained by adjusting the traction speed; specific parameters are detailed below. Figure 5 The table.

[0050] The difference between Examples 4-6 and Examples 1-3 lies in the concentration of the prepared Pebax solution. In Examples 4-6, the concentration of the Pebax solution is adjusted to 6% (w / v), while the other steps and parameters are the same as in Examples 1-3. By adjusting the concentration of the Pebax solution and the traction speed, coatings 200 of different thicknesses can be obtained; specific parameters are detailed in [link to relevant documentation]. Figure 5 The table.

[0051] Comparative Example 1 uses pure PTFE pipe without any coating treatment as a control group to compare the technical effects of the present invention. The pipe has not undergone dip coating treatment and has no Pebax coating 200 on its surface.

[0052] The PTFE pipes prepared in Examples 1-6 and Comparative Example 1 were braided to form composite conduit structures. Subsequently, burst pressure tests were performed on each group of samples. The test results are shown in [Figure number missing]. Figure 6 The table.

[0053] In the description of this specification, the references to terms such as "an embodiment, some embodiments, illustrative embodiments, example, specific example, or examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] The terms "first," "second," "third," "fourth," etc. (if applicable) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0055] It should also be noted that, in the description of this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0056] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may also include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or apparatus.

[0057] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A medical catheter, characterized in that, include: The inner tubing is made of polytetrafluoroethylene (PTFE). The coating, covering the outer surface of the inner tubing, is made of nylon elastomer material; A metal braided layer is disposed on the outer side of the coating; The intermediate layer, made of nylon elastomer material, covers the outside of the metal braided layer; The outer layer, made of nylon material, covers the outside of the middle layer.

2. The medical catheter according to claim 1, characterized in that, The coating and the intermediate layer are made of the same or compatible nylon elastomer material and are fused together after hot-melt processing.

3. The medical catheter according to claim 1 or 2, characterized in that, The nylon elastomer material is Pebax.

4. The medical catheter according to claim 3, characterized in that, The Pebax material is Pebax 4033.

5. The medical catheter according to claim 1, characterized in that, The coating thickness is from 0.0001 inches to 0.01 inches.

6. A method for preparing a medical catheter as described in any one of claims 1-5, characterized in that, Includes the following steps: Solution preparation: Dissolve the nylon elastomer material in an organic solvent to obtain a homogeneous nylon elastomer solution; Dip coating: The inner tube made of polytetrafluoroethylene is immersed in a container containing the nylon elastomer solution, so that a solution layer is attached to its surface; Drying: The dip-coated inner tube is heated in a sintering furnace to evaporate the solvent and form a solid coating made of nylon elastomer material on the surface of the inner tube.

7. The preparation method according to claim 6, characterized in that, The dip coating process employs a continuous traction method, with the inner tube passing through the container and the sintering furnace at a set traction speed of 1 m / min to 10 m / min.

8. The preparation method according to claim 6, characterized in that, The sintering furnace is equipped with several temperature control zones, and the temperature of each temperature control zone is independently controlled between 100°C and 200°C.

9. The preparation method according to claim 7, characterized in that, The thickness of the coating is controlled by adjusting the concentration of the nylon elastomer solution and / or the traction speed.

10. The preparation method according to claim 6, characterized in that, The dried inner tubing also includes a cleaning step to remove residual organic solvents from the surface.

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