JP4796534B2 - Method for manufacturing catheter tube - Google Patents

Description

  The present invention relates to a method for manufacturing a catheter tube used in a blood vessel or a body cavity, and more particularly, to a method for manufacturing a catheter tube having a distal end inner diameter reduced compared to a proximal inner diameter.

  The catheter tube needs to be selectively advanced along a guide wire introduced in advance in a blood vessel or a body cavity branched in a complicated manner in the body. In addition, it is necessary to have excellent properties for injecting therapeutic drugs or injecting diagnostic contrast agents. For this reason, increase the inner and outer diameters on the proximal side, secure the drug and contrast agent injection characteristics while providing sufficient rigidity and pushability, and make the inner and outer diameters thinner and more flexible on the distal side than the proximal side. This improves the reachability to the peripheral blood vessels and the followability to the guide wire.

  In general, a catheter tube used in a blood vessel is reinforced with a metal wire, a resin fiber, or the like in order to improve pushability and kink resistance. Such a tube has a lumen that communicates from the proximal side to the distal end side and a tube that is configured to reduce rigidity by reducing the inner and outer diameters from the proximal side to the distal end side. Tube) or a tube in which an inner layer and a reinforcing layer continuous from the proximal side to the distal end and an outer layer composed of a resin whose rigidity decreases from the proximal side to the distal end side are integrated by hot stretching. Has been realized.

  As a conventional catheter tube, for example, nylon, which is a thermoplastic polyamide resin, is first temporarily extruded into a tube shape having an outer diameter of 0.75 mm and an inner diameter of 0.5 mm, and then the outer diameter is 0.46 mm. The stainless steel wire was inserted, and then passed through a die having an inner diameter of 0.56 mm heated to 150 ° C., and subjected to stretching. There is a catheter tube whose diameter is reduced by this hot drawing process (Patent Document 1). According to this configuration, a catheter tube having a smaller inner diameter on the distal end side than an inner and outer diameter on the proximal side and a more flexible distal end side can be obtained.

  On the other hand, the catheter tube that is inserted into the body must have sufficient strength, flexibility and elasticity, and as a conventional technique for realizing this, the original tube is set in a stretching device that can be heated and pulled. The original tube is heated, the heated portion is primarily stretched by hot stretching, and after the primary stretching, the stretched portion is secondarily stretched at room temperature, and the secondary stretched portion forms the small-diameter portion and is adjacent to the small-diameter portion. There is a stepped catheter in which the large-diameter portion is formed by an original tube of a non-heated non-stretched portion (Patent Document 2). According to this configuration, since the large-diameter portion and the small-diameter portion of the catheter tube are formed, there is no risk of separation or breakage due to the integral formation with the small-diameter portion, and a highly reliable catheter can be obtained.

  Also, in the operation of introducing into a complex meandering blood vessel or introducing a contrast / embolization substance, the tube is extended due to the sliding resistance when passing through the catheter lumen and the guide wire / embolization substance or pressurization during the contrast enhancement. There was a problem of impairing sex. As a conventional technique for suppressing the elongation in the axial direction, a reinforcing material layer is wound in a coil shape on an inner layer pipe at a rough pitch, and then the strand wound on this coarse pitch and the inner layer pipe are further combined. There is a catheter tube wound in a coil shape with a wire (Patent Document 3).

  Also, a shaft that is provided in parallel with the catheter tube between the intermediate layer and the outer wall of the inner layer is provided with a rigid body formed in a mesh shape by a linear body, or is embedded in the wall thickness. There is a catheter tube in which a reinforcing body formed of a metal wire extending in a direction is embedded and integrated in a catheter tube wall (Patent Document 4).

  In addition, there is a catheter tube having a structure in which an axial member is provided between a braided assembly and a braided assembly assembled in the opposite direction when the reinforcing layer is formed by braiding (Patent Document 5).

  According to these configurations, the axial extension of the catheter tube can be suppressed, and the operability of the catheter tube can be improved.

On the other hand, a PTFE resin dispersion is applied, baked and sintered on a mandrel rod, and then a solid particle-blended PTFE resin dispersion is coated, baked and sintered to form a solid particle-blended PTFE resin overcoat pure PTFE tube. There is a method for producing a tube directly or directly after providing a blade layer and extruding the outer covering layer, finally pulling out the mandrel rod, and taking out the inner layer PTFE composite catheter tube (Patent Document 6, etc.). According to this manufacturing method, a catheter tube can be manufactured by dip formation by pulling out the mandrel bar after applying, baking, and sintering the PTFE resin dispersion on the mandrel bar, regardless of extrusion formation.
JP 2000-296179 A JP 2001-299926 A JP 2006-158878 A JP-A-3-141958 Japanese translation of PCT publication No. 2002-535049 JP 2000-51365 A

  However, according to the catheter tubes of Patent Document 1 and Patent Document 2, the hot-stretched catheter tube retains strain due to residual stress at the time of stretching. At the time of hot melt processing, there is a problem that residual strain is affected and the inner and outer diameters in the vicinity of the melted portion become thick, so that the dimensional accuracy is deteriorated, resulting in a decrease in yield.

  In addition, according to the catheter tube of Patent Documents 3, 4, and 5, in the catheter tube in which horizontal winding or braiding with a metal wire, resin fiber, or the like is applied as a reinforcing layer, the reinforcing layer is formed by stretching. Therefore, there is a problem in that the winding pitch of the reinforcing layer (interstitial distance in the case of braiding) is increased, and the flexibility and kink resistance are impaired.

  Further, according to the catheter tube of Patent Document 6, a catheter tube having the same diameter is possible, but there is no disclosure of a catheter tube manufacturing method in which the inner and outer diameters on the distal end side are narrower than the proximal side.

  Therefore, the object of the present invention is to reduce the cost without stretching the integrated tube, to increase the rigidity on the proximal side, to have excellent liquid feeding characteristics, and to reduce the inner and outer diameters on the distal end side compared to the proximal side. Providing a method for manufacturing a catheter tube with excellent kink properties, and even in a small-diameter flexible portion of a tube having a reinforcing layer, the flexibility is impaired without changing the winding pitch of the reinforcing layer (interstitial distance in the case of braiding) The present invention provides a method for manufacturing a catheter tube, and further reduces the dimensional change in the length direction by suppressing elongation even at a thin and flexible distal end portion by the catheter tube having an axial reinforcing member. It aims at providing the manufacturing method of.

[1] In order to achieve the above object, the present invention provides a core wire preparation step of preparing a core wire having a large diameter portion and a thin diameter portion, and a covering formation for forming a covering by coating a synthetic resin on the core wire possess a step, and the coating forming step core removing step of removing the core wire buried in the covering member after the said coating formation step, dissolving or dispersing the synthetic resin the core wire in a predetermined solvent A method for producing a catheter tube is provided , wherein the synthetic resin is coated around the core wire by dipping in the coating liquid and pulling up at a predetermined speed .

[2] In order to achieve the above object, the present invention provides a core wire preparation step of preparing a core wire having a large-diameter portion and a thin-diameter portion, and a covering formation for forming a covering by coating a synthetic resin on the core wire Step , after the covering body forming step, at least part of the covering body, forming a reinforcing layer using a metal wire, a resin fiber, or a combination of these, and after the reinforcing layer forming step, An outer layer covering body forming step for forming an outer layer covering body integrally covering the covering body and the reinforcing layer with a thermoplastic resin, and a core wire removal for removing the core wire buried in the covering body after the outer layer covering body forming step. possess a step, wherein the coating forming step is immersed in the coating liquid obtained by dissolving or dispersing the synthetic resin the core wire in a predetermined solvent, by pulling at a predetermined speed, the surrounding of the core wire Synthetic resin It is coated to provide a method of manufacturing a catheter tube according to claim.

[ 3 ] The catheter according to [1] or [2], wherein in the core wire removing step, the core wire is removed from the covering body in the direction of the large diameter portion of the core wire. It may be a manufacturing method of a tube.

[ 4 ] In the above invention, in the reinforcing layer forming step, the catheter tube according to the above [2], wherein the covering body is braided with metal wires or resin fibers at a predetermined interstitial distance. It may be a manufacturing method.

[ 5 ] In the above invention, in the reinforcing layer forming step, a predetermined interstitial distance is formed on the covering and the metal wire or resin fiber while the metal wire or resin fiber is vertically aligned on the covering. The method for producing a catheter tube according to [2] above, wherein braiding is performed with a metal wire or resin fiber.

[ 6 ] In the above invention, in the outer layer covering body forming step, the reinforcing layer forming step is sequentially covered with a thermoplastic tube and a heat shrinkable tube formed of a thermoplastic resin on the covering body and the reinforcing layer, The method according to [2], wherein the thermoplastic tube is heated at a predetermined temperature to melt and integrate, and the heat-shrinkable tube is shrunk and then removed by peeling off the heat-shrinkable tube. The method for manufacturing a catheter tube may be used.

[1], according to the configuration of 及 beauty [3], the inner diameter of the distal end than the proximal side outer diameter is reduced, the pushing of the proximal portion, the distal end portion is flexible without impairing the liquid transfer property, Guide wire followability and kink resistance are improved. Furthermore, since there is no need to perform tube stretching, there is no distortion due to stretching, processability is improved, and as a result, a method for manufacturing a catheter tube can be provided at low cost.

According to the configuration of [2], [ 4 ] to [ 6 ], the inner diameter and outer diameter on the distal end side are smaller than the proximal side, and accordingly, the outer diameter on the distal end side is smaller than the proximal side, and the proximal portion is reduced. The tip portion becomes flexible without impairing the pushability and liquid feeding characteristics, and the guide wire followability and kink resistance are improved. In addition, since there is no need to perform tube stretching, there is no distortion due to stretching, and the processability is improved, resulting in lower costs. In addition, since the dimensional change in the length direction is small due to the reinforcing members arranged in the axial direction, and the winding pitch of the reinforcing layer (interstitial distance in the case of braiding) does not increase due to stretching, the tip portion is flexible. The manufacturing method of the tube for catheters excellent in property and kink resistance can be provided.

  According to the present invention, without stretching an integrated tube, the hand side has high rigidity and excellent liquid feeding characteristics, the tip side has a smaller inner and outer diameter than the hand side, and is flexible and kink resistant. To provide a superior catheter tube manufacturing method, and to prevent loss of flexibility in a thin flexible portion of a tube having a reinforcing layer without changing the winding pitch of the reinforcing layer (interstitial distance in the case of a braid) And a catheter tube having an axial reinforcing member, and the catheter tube having an axial reinforcing member suppresses elongation even at a thin and flexible distal end portion and manufactures a catheter tube with little dimensional change in the length direction. A method can be provided.

(Method for manufacturing catheter tube 10 according to the first embodiment)
FIG. 1 is a diagram illustrating a method of manufacturing a catheter tube 10 according to the first embodiment in the order of steps.

  The catheter tube manufacturing method according to the first embodiment includes a core wire preparation step (FIG. 1A) for preparing a core wire 2 having a large diameter portion 2 a and a small diameter portion 2 b, and a synthetic resin on the core wire 2. Covering body forming step (FIG. 1 (b)) and core wire removing step of removing core wire 2 buried in covering body 3 after forming covering body 3 (FIG. 1 (c)) And is configured.

  The core wire preparation step is performed by machining the core wire 2 by mechanical processing such as cutting, polishing, grinding, forging, drawing or drawing using a split die, or chemical processing such as etching, and the large diameter portion 2a having a predetermined outer diameter. Preparing the core wire 2 subjected to the diameter reduction process such that the small diameter part 2b having an outer diameter smaller than the large diameter part 2a has a predetermined length or the diameter reduction process as described above by purchase or the like It is a process to do.

  Here, as the core wire 2, a metal such as a copper wire or a stainless steel soft wire, or a resin strand such as polyamide (PA) can be used, and its cross section is not limited to a circle, but can be an ellipse, a semicircle, a polygon, and the like. .

  In the covering body forming step, the synthetic resin is immersed in a coating solution in a predetermined concentration at a predetermined concentration and pulled up at a predetermined speed to coat the periphery of the core wire 2 with the synthetic resin. A thick covering 3 is formed, that is, dip molding is performed.

  Synthetic resin can be used for the covering 3, and polyamide (PA), polyimide (PI), and fluorine resin are preferable. The covering 3 may have a laminated structure of not only one layer but also two or more layers. Further, a covering method in which the rigidity of the tube changes continuously or stepwise from the proximal side to the distal end side may be used.

  In the core wire removing step, the core wire 2 and the end portion 20 of the covering 3 are cut or removed with a predetermined dimension (for example, 20 mm) so that the core wire 2 is exposed, and then fixed to a drawing machine and fixed to the whole core wire 2. Is a step of drawing the core wire 2 from the large diameter portion 2a side to the large diameter portion 2a direction (A direction in FIG. 1).

(Effects of the first embodiment)
According to the manufacture of the catheter tube according to the first embodiment, it is possible to manufacture a catheter tube having the large-diameter portion 2a as the proximal side and the thin-diameter portion 2b as the distal end side. The tip portion becomes flexible without impairing the liquid feeding characteristics, and the guide wire followability and kink resistance are improved. Furthermore, since there is no need to stretch the tube, there is no distortion due to stretching, the workability is improved, and as a result, a low-cost catheter tube can be manufactured.

Example 1
Using a silver-plated copper wire with an outer diameter of 1.5 mm (or a metal strand that can be stretched, such as a stainless soft wire, or a resin strand such as polyamide (PA)), using a centerless grinder with a large diameter portion 2a having a length of 1800 mm and a length of 150 mm The core wire 2 having the small-diameter portion 2b that has been reduced to an outer diameter of 1.2 mm by cutting. The core wire may be reduced in diameter by drawing stretching using sandblasting or split dies or stretching by tension.

    This core wire 2 is dipped in a coating solution in which a Shore hardness 55D polyurethane (Pelecene made by Dow Chemical Japan Co., Ltd.) as a synthetic resin is dissolved in DMF (dimethylformamide), and dip-molded at a pulling speed of 2 m / min. Drying with hot air at 5 ° C. for 5 minutes is repeated twice, and the coated body is an extrusion molded body having substantially the same thickness, with the coating diameter of the large diameter portion 2a being 1.7 mm and the coating diameter of the small diameter portion 2b being 1.4 mm. Get 3.

  Next, about 20 mm of the coating on both ends is removed and the copper wire is exposed and fixed to a drawing machine. After the entire core wire 2 is drawn, the wire core 2 is pulled out from the large-diameter portion 2a side, and the large-diameter portion 2a The catheter tube having a predetermined length was manufactured by cutting so that the length of the narrow-diameter portion 2b was 100 mm.

(Comparative Example 1)
For example, on a copper wire with an outer diameter of 1.5 mm, a Shore hardness of 55D polyurethane (Peresen manufactured by Dow Chemical Japan Co., Ltd.) is used as a thermoplastic resin, and a molding temperature of about 200 ° C. (die temperature) is performed with a 32 mm extruder. By extrusion-molding at a take-up speed of 22 m / min, a molded body having a coating outer diameter of 1.7 mm is obtained.

  The raw tube which becomes a catheter tube was obtained by cutting at each predetermined position and drawing the whole of the core wire of the product obtained by cutting after drawing.

Next, a die having an inner diameter of 1.4 mm is heated to a temperature of 120 ° C., and a stainless steel core wire having an outer diameter of 1.2 mm is passed through the tube, and then the tip 200 mm is pulled out to obtain the normal diameter portion 1600 mm and the reduced diameter portion 100 mm. (The diameter and length of the normal diameter portion and the reduced diameter portion may be arbitrary) to obtain a catheter tube.
(Comparative Example 2)

  For example, on a copper wire having an outer diameter of 1.2 mm, a shore hardness of 55D polyurethane (Peresen manufactured by Dow Chemical Japan Co., Ltd.) is used as a thermoplastic resin, and the molding temperature is about 200 ° C. (die temperature) with a 32 mm extruder. By extruding at a take-up speed of 22 m / min, a molded body having a coating outer diameter of 1.4 mm is obtained.

  The tube for catheter was obtained by cut | disconnecting by the predetermined dimension and drawing the whole said core wire of the thing obtained by cutting | disconnection after extending | stretching.

  FIG. 2 is a diagram for explaining a method of measuring the three-point bending performance of a catheter tube. Three-point bending performance is evaluated by the maximum test force (N) required to push a distance of 15 mm between fulcrums at a speed of 100 mm / min by 20 mm. The maximum test force is three-point bending (N). It is excellent in. In addition, as a test apparatus, the strength tester generally used, an indentation tester, etc. can be used.

  FIG. 3 is a diagram for explaining a method for measuring the buckling performance of a catheter tube by the procedures of (a), (b), and (c). The buckling performance was evaluated by making a circle with a sample length of 200 mm (a), reducing the diameter of the circle (b), and evaluating the diameter (c) immediately before buckling as the buckling diameter (mm). The smaller the diameter (mm), the better the buckling characteristics.

FIG. 4 is a diagram showing an outline of an apparatus for measuring liquid feeding characteristics. The test solution (water) is fed to the catheter tube 10 supported by the stand 100 by a syringe 101 at a predetermined pushing speed (100 mm / min), and the maximum force at that time is measured by the digital force gauge 102 to send the solution. Measure force (N).

  From the comparison results in Table 1, the catheter tube manufactured by the catheter tube manufacturing method according to Example 1 has a small diameter portion with little heat shrinkage (low distortion) and excellent buckling characteristics and flexibility. From the comparison results of Table 2, it has excellent liquid feeding characteristics equivalent to those having no small diameter portion, although it has a small diameter portion.

(Second Embodiment)
FIG. 5 is a diagram showing a method of manufacturing the catheter tube 10 according to the second embodiment in the order of steps.

  The catheter tube manufacturing method according to the second embodiment includes a core wire preparation step (FIG. 5A) for preparing a core wire 2 having a large diameter portion 2 a and a small diameter portion 2 b, and a synthetic resin on the core wire 2. A covering body forming step (FIG. 5 (b)) for covering the surface and forming a covering body 3, and after the covering body forming step, at least part of the covering body 3 is made of a metal wire, a resin fiber, or a combination thereof. After the reinforcing layer forming step (FIG. 5C) for forming the reinforcing layer 5 and the reinforcing layer forming step, the outer layer covering body 4 that integrally covers the covering body 3 and the reinforcing layer 5 is formed with a thermoplastic resin. An outer layer covering body forming step (FIG. 5 (d)) and a core wire removing step (FIG. 5 (e)) for removing the core wire 2 buried in the covering body 3 after the outer layer covering body forming step are configured.

  Since the core wire preparation step, the covering body formation step, and the core wire removal step are the same as those in the first embodiment, the description thereof will be omitted, and the steps different from those in the first embodiment will be described below.

  In the reinforcing layer forming step, a metal wire such as platinum (Pt) / tungsten (W), a resin fiber, or a combination of these strands is used to continuously braid the covering 3 with a predetermined interstitial distance. This is a step of forming the reinforcing layer 5 by the above. The braid may be wound around the wire while changing the winding direction, such as horizontal winding, right-hand winding or left-hand winding in the same direction, and the winding pitch and interstitial distance are not particularly limited. In addition, when a fluorine resin is used as the covering 3, the surface is roughened by chemical etching in advance.

  In the outer layer covering body forming step, the covering body 3 and the reinforcing layer 5 are covered with a heat shrinkable tube and then melted and integrated at a predetermined temperature, and then the heat shrinkable tube is peeled off to cover the large diameter portion 2a and the small diameter portion 2b. Obtains a molded body on which the outer layer covering 4 having substantially the same thickness is formed.

(Effect of the second embodiment)
According to the manufacture of the catheter tube according to the second embodiment, it is possible to manufacture a catheter tube having the large-diameter portion 2a as the proximal side and the thin-diameter portion 2b as the distal end side, thereby pushing the proximal portion. The tip portion becomes flexible without impairing the liquid feeding characteristics, and the guide wire followability and kink resistance are improved. In addition, since there is no need to perform tube stretching, there is no distortion due to stretching, and the processability is improved, resulting in lower costs. Further, since the winding pitch of the reinforcing layer 5 (interstitial distance in the case of a braid) does not increase due to stretching, a method for manufacturing a catheter tube excellent in flexibility and kink resistance of the distal end portion becomes possible. Further, when the reinforcing layer 5 is braided on the covering 3, in addition to the above effects, it is possible to manufacture a catheter tube with a small dimensional change in the length direction.

(Example 2)
Core wire 2 is prepared by reducing the diameter of a silver-plated copper wire with an outer diameter of 0.8 mm to a length of 1800 mm of the large diameter portion 2 a and 150 mm at one end to a small diameter portion 2 b with an outer diameter of 0.7 mm by centerless polishing. To do. The core wire 2 is made of PTFE (Teflon (registered trademark) manufactured by Mitsui Dupont Fluorochemical Co., Ltd.), which is a fluororesin, as a synthetic resin. However, low-friction materials such as polyamide (PA) and polyimide (PI) in addition to PTFE, which is a fluororesin, are desirable) Dip-molded at a liquid temperature of 20 ° C. and a pulling rate of about 4 m / min. After drying for 2 minutes, it is sintered in a heating furnace at 400 ° C. for 2 minutes, and has a covering 3 having substantially the same thickness with a covering diameter of the large diameter portion 2a of 0.85 mm and a covering diameter of the thin diameter portion 2b of 0.75 mm. A molded body is obtained. After the surface of the covering 3 is roughened by chemical etching (this treatment is not necessary when the resin of the covering 3 is not a fluororesin), SUS304 having a diameter of 0.03 mm is used on the covering 3 (elementary). The wire may be a metal wire such as platinum (Pt) / tungsten (W) or resin fiber) and be braided with a 16-beat lattice distance of 0.18 mm (reinforcement method is horizontal winding, right-handed or left-handed in the same direction) The wire may be wound while changing the winding direction, and the winding pitch and interstitial distance are not particularly limited. Nylon (PEBAX manufactured by Arkema Co., Ltd.) is used as the thermoplastic resin (the outer cover 4 is also thermoplastic. There is no particular limitation as long as it is a resin, and a tube having an inner diameter of 0.86 mm and an outer diameter of 1.11 mm, and a heat-shrinkable tube having a contraction diameter of about 0.8 mm, which may be mixed with a thermoplastic resin and an X-ray opaque material. After melting and integrating in a 250 ° C. oven for about 3 minutes, the heat-shrinkable tube is peeled off and the coating diameter of the large diameter portion 2a is 1.1 mm and the coating diameter of the small diameter portion 2b is 1.0 mm. A thick molded body is obtained.

  Next, about 20 mm of the coating on both end portions 20 is removed to expose the copper wire, and then fixed to a drawing machine. After the entire core wire 2 is drawn, the wire core 2 is pulled out from the large diameter portion 2a side, and the large diameter portion A predetermined catheter tube was manufactured by cutting so that 2a was 1600 mm and the small diameter portion 2b was 100 mm.

(Third embodiment)
FIG. 6 is a diagram illustrating a method of manufacturing the catheter tube 10 according to the third embodiment in the order of steps.

  The catheter tube manufacturing method according to the third embodiment includes a core wire preparation step (FIG. 6A) for preparing a core wire 2 having a large diameter portion 2 a and a small diameter portion 2 b, and a synthetic resin on the core wire 2. A covering body forming step (FIG. 6 (b)) for covering the surface of the covering body 3 and a reinforcing body 6 made of metal wire or resin fiber are vertically disposed on at least a part of the covering body 3 after the covering body forming step. A reinforcing layer forming step (FIG. 6 (c)) in which the reinforcing layer 5 is formed on the covering 3 and the reinforcing body 6 by braiding with a metal wire or a resin fiber at a predetermined interstitial distance. After the reinforcing layer forming step, an outer layer covering body forming step (FIG. 6 (d)) for forming the outer layer covering body 4 integrally covering the covering body 3 and the reinforcing layer 5 with a thermoplastic resin, and an outer layer covering body forming step. A core wire removing step for removing the core wire 2 buried in the covering 3 later (FIG. 6). e)) and configured to have a.

  Since the core wire preparation step, the covering body formation step, and the core wire removal step are the same as those in the second embodiment, the description thereof will be omitted, and the steps different from those in the second embodiment will be described below.

  In the reinforcing layer forming step, a metal wire such as platinum (Pt) / tungsten (W), a resin fiber, or a material such as platinum (Pt) / tungsten (W) is provided so as to cover the reinforcement body 6 while vertically extending the reinforcement body 6 such as a resin fiber or a metal wire In this step, the reinforcing layer 5 is formed by continuously braiding the covering 3 with a predetermined interstitial distance using the strands together. The braid may be wound around the wire while changing the winding direction, such as horizontal winding, right-hand winding or left-hand winding in the same direction, and the winding pitch and interstitial distance are not particularly limited. In addition, when a fluorine resin is used as the covering 3, the surface is roughened by chemical etching in advance.

  The outer layer covering body forming step includes covering the covering body 3, the reinforcing layer 5 and the reinforcing body 6 with a heat-shrinkable tube and then fusing and integrating them at a predetermined temperature, and then peeling off the heat-shrinking tube to remove the large diameter portion 2a and the small diameter portion. A molded body is obtained in which the outer layer covering 4 having the same coating diameter 2b is formed.

(Effect of the third embodiment)
According to the manufacture of the catheter tube according to the third embodiment, it is possible to manufacture a catheter tube having the large diameter portion 2a as the proximal side and the small diameter portion 2b as the distal end side. The tip portion becomes flexible without impairing the liquid feeding characteristics, and the guide wire followability and kink resistance are improved. In addition, since there is no need to perform tube stretching, there is no distortion due to stretching, and the processability is improved, resulting in lower costs. Further, since the winding pitch of the reinforcing layer 5 (interstitial distance in the case of a braid) does not increase due to stretching, a method for manufacturing a catheter tube excellent in flexibility and kink resistance of the distal end portion becomes possible. Furthermore, since it has the reinforcement body 6 and the braided reinforcement layer 5 which were longitudinally arranged on the covering 3, in addition to the above effects, the dimensional change in the length direction is caused by the reinforcement body 6 arranged in the axial direction. A method for manufacturing a small catheter tube is possible.

(Example 3)
Core wire 2 is prepared by reducing the diameter of a silver-plated copper wire with an outer diameter of 0.8 mm to a length of 1800 mm of the large diameter portion 2 a and 150 mm at one end to a small diameter portion 2 b with an outer diameter of 0.7 mm by centerless polishing. To do. The core wire 2 is made of PTFE (Teflon (registered trademark) manufactured by Mitsui Dupont Fluorochemical Co., Ltd.), which is a fluororesin, as a synthetic resin. However, low-friction materials such as polyamide (PA) and polyimide (PI) in addition to PTFE, which is a fluororesin, are desirable) Dip-molded at a liquid temperature of 20 ° C. and a pulling rate of about 4 m / min. After drying for 2 minutes, it is sintered in a heating furnace at 400 ° C. for 2 minutes, and has a covering 3 having substantially the same thickness with a covering diameter of the large diameter portion 2a of 0.85 mm and a covering diameter of the thin diameter portion 2b of 0.75 mm. A molded body is obtained.

  After the surface of the covering 3 is roughened by chemical etching (this treatment is not necessary when the covering 3 is not a fluororesin), resin fibers (Kuraray Vectran, Inc.) having a diameter of about 0.03 mm are applied to the covering 3. The axial reinforcing member is made of SUS304 having a diameter of 0.03 mm so as to cover the reinforcing member 6 made of stainless steel, a metal such as NiTi alloy, or nylon / fluororesin fiber (longitudinal). (A metal wire such as (Pt) / tungsten (W) or a resin fiber may be used), and a reinforcing layer 5 is formed by braiding with 16 struts and a distance of 0.18 mm between lattices (the reinforcing method is horizontal winding in the same direction) The wire may be wound while changing the winding direction, such as right-handed or right-handed or left-handed, and the winding pitch and interstitial distance are not particularly limited. Nylon as a thermoplastic resin (PEBA manufactured by Arkema Co., Ltd.) (The outer layer cover 4 is not particularly limited as long as it is also a thermoplastic resin. In addition, a tube having an inner diameter of 0.86 mm and an outer diameter of 1.11 mm, which may be mixed with a thermoplastic resin) After covering with a heat shrinkable tube having a shrinkage diameter of about 0.8 mm, melting and integrating in an oven at 250 ° C. for about 3 minutes, the heat shrinkable tube is peeled off, and the coating diameter of the large diameter portion 2a is 1.1 mm, the small diameter portion A molded body having substantially the same thickness and a coating diameter of 2b of 1.0 mm is obtained.

  Next, about 20 mm of the coating on both ends is removed and the copper wire is exposed and fixed to a drawing machine. After the entire core wire 2 is drawn, the wire core 2 is pulled out from the large-diameter portion 2a side, and the large-diameter portion 2a Were cut so that the 1600 mm narrow diameter portion 2b was 100 mm, and a predetermined catheter tube was manufactured.

(Comparative Example 3)
On a copper wire having an outer diameter of 0.8 mm, PTFE (Teflon (registered trademark) manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) dispersion liquid, which is a fluororesin, is used as a synthetic resin, and the liquid temperature is 20 ° C., about 4 m / min. The inner layer having a coating outer diameter of 0.85 mm is obtained by dip-molding at a pulling rate, drying with hot air at 350 ° C. for 2 minutes, and sintering in a heating furnace at 400 ° C. for 2 minutes. Further, the inner layer surface is roughened by chemical etching.

  On this inner layer, SUS304 having a diameter of 0.03 mm was used, and a braid having a distance of 0.18 mm and 16 striking lattices was continuously applied. Nylon (PEBAX manufactured by Arkema Co., Ltd.) was used as a thermoplastic resin, and 30 mm The extrusion molding with a coating diameter of 1.1 mm is obtained by extrusion molding at a molding temperature of 220 ° C. (die temperature) and a take-up speed of about 14 m / min. After cutting at each predetermined position and extending the whole core wire of the product obtained by cutting, the core wire was pulled out to obtain a predetermined original tube for a catheter tube.

  Next, a stainless steel core wire having an outer diameter of 0.7 mm is inserted into the tube, a metal die having an inner diameter of 1.0 mm is heated to a temperature of 125 ° C., the tube tip is pulled out from the die, and heated and stretched for catheter use. A tube was obtained.

(Comparative Example 4)
On a copper wire having an outer diameter of 0.7 mm, PTFE (Teflon (registered trademark) manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), which is a fluororesin, is used as a synthetic resin. The liquid temperature is 20 ° C. and about 4 m / min. The inner layer having a coating outer diameter of 0.75 mm is obtained by dip-molding at a pulling rate, drying with hot air at 350 ° C. for 2 minutes and then sintering in a heating furnace at 400 ° C. for 2 minutes. Further, the inner layer surface is roughened by chemical etching.

  On this inner layer, SUS304 having a diameter of 0.03 mm was used, and a braid having a distance of 0.18 mm and 16 striking lattices was continuously applied. Nylon (PEBAX manufactured by Arkema Co., Ltd.) was used as a thermoplastic resin, and 30 mm The extrusion molding with a coating diameter of 0.99 mm is obtained by extrusion molding at a molding temperature of 220 ° C. (die temperature) and a take-up speed of about 14 m / min. After cutting at each predetermined position and extending the entire core wire of the product obtained by cutting, the core wire was pulled out to obtain a predetermined catheter tube.

  From the comparison results in Table 3, Examples 2 and 3 have a small diameter portion that is excellent in buckling characteristics and flexibility and has little heat shrinkage.

  Moreover, from the data of Table 4, although Example 2 and 3 have the thin diameter part 2b, while having the liquid feeding characteristic equivalent to the original tube of the comparative example 3 which does not have the small diameter part 2b, As shown by the data in FIG. 3, compared with Comparative Example 3 in which the interstitial distance of the braid is also extended by stretching, Examples 2 and 3 are small diameter portions having excellent buckling characteristics and flexibility and less heat shrinkage. It can be seen that a catheter tube having 2b can be manufactured.

Table 5 shows the results of comparing the yield strengths of the small diameter portions of Example 3 and Comparative Example 3. The maximum value of strength at which the shape was restored from the curve obtained by the tensile test was measured, and this was taken as the yield strength. Since Example 3 and Comparative Example 3 differ only in the presence or absence of the shaft reinforcing member, the difference in yield strength was compared and examined as difficulty in elongation.

  From the comparison result of Table 5, Example 3 characterized by having an axial reinforcing member has a characteristic that it is difficult to extend in the length direction as compared with Comparative Example 3. Moreover, from the comparison result of Table 4, although Example 3 has a thin diameter part, it has the liquid feeding characteristic equivalent to the original tube of the comparative example 3 which does not have a thin diameter part, and buckling characteristic, A catheter tube having a small diameter portion with excellent flexibility and less heat shrinkage can be provided.

Example 4
FIG. 7 shows a modification of the first embodiment. The catheter tube 10 may be made of a plurality of layers of coverings, and FIG. 7 shows the catheter tube 10 formed of a first covering 30a and a second covering 30b. That is, in the covering forming process, the manufacturing method includes two steps of performing dip forming of the first covering 30a and dip forming of the second covering 30b.

  Further, a coating method in which the rigidity of the tube changes continuously or stepwise from the proximal side to the distal end side may be employed. The first covering body 30a is thickly formed at the proximal side and thinly formed toward the distal end side, and the second covering body 30b is disposed at the proximal side. It is thinly formed on the side and thick on the tip side. That is, in the covering forming process, the thickness of the covering can be controlled by changing the pulling speed at the time of dip molding.

  Thereby, performance improvement, such as pushing property of a hand part and guide wire followability, can further be aimed at.

(Example 5)
FIG. 8 shows another modification of the first embodiment. There may be one or more lumens of the catheter tube 10, and in FIG. 8, there are two lumens 31a and 31b. This lumen is formed by a core wire having a reduced diameter, but it is sufficient that one or more core wires have a reduced diameter. The example of FIG. 8 shows an example in which the lumen 31a is formed by a core wire having a reduced diameter in the BB cross section, whereas the lumen 31b is formed by a core wire in which the diameter is not reduced in the CC cross section. ing. That is, only the lumen 31a is reduced in diameter. That is, the catheter tube 10 as described above can be manufactured by preparing the core wires corresponding to the lumens 31a and 31b in the core wire preparation step.

(Example 6)
FIG. 9 shows a modification of the catheter tube having the reinforcing layer of Example 2 or 3, wherein the inner diameter of the distal end portion is reduced, and the hardness and outer diameter of the covering are gradually increased from the proximal side to the distal end. It is a figure which shows the structure which is reducing.

  FIG. 9A shows braiding by forming the reinforcing body 5 only on the large-diameter portion 2a or covering the outer layer covering body 4 by removing a part of the reinforcing body 5 in the reinforcing layer forming step. It is manufactured to have a part and a non-braided part.

  FIG. 9B shows a catheter tube having a structure in which the outer layer laminate 7 is laminated on the catheter tube 10 of Example 2 or 3. That is, in the outer layer covering body forming step, a step of covering the large diameter portion 2a with a heat shrinkable tube and melting and integrating at a predetermined temperature is added.

(Example 7)
FIGS. 10A and 10B show a cross section of the catheter tube having the reinforcing layer of Example 2 or 3, and are an example showing another cross-sectional shape of Example 2 or 3. FIG. FIG. 10A shows an example of a cross-sectional shape having a different lumen shape (ellipse, semicircle, etc.), and FIG. 10B shows an example of a cross-sectional shape when the lumen shape is multi-lumen.

  That is, the catheter tube 10 as described above can be manufactured by preparing the core wires corresponding to the lumens 31c to 31h in the core wire preparation step.

(Example 8)
FIGS. 11A and 11B show a cross section of a catheter tube including a reinforcing body 6 in the reinforcing layer 5 of Example 3, and are embedded in the covering 3 or the outer covering 4. It is an example. In addition, the reinforcement body 6 as an axial direction reinforcement member should just be one or more.

  This is possible by controlling the temperature so that the reinforcing body 6 is embedded in the molten thermoplastic resin in the covering body forming step or the outer layer covering body forming step.

Example 9
12 (a) and 12 (b) show a catheter tube including a reinforcing body 6 in the reinforcing layer 5 of Example 3 and a right cross section thereof (the outer cover 4 is not shown). In this example, the positional relationship with the reinforcing body 6 is different from that of the third embodiment. FIG. 12A shows an example of a configuration in which the reinforcing body 6 is integrated with the reinforcing layer 5, that is, a configuration in which the reinforcing layer 5 and the reinforcing body 6 are braided together. That is, it becomes possible by braiding the reinforcing layer 5 and the reinforcing body 6 together in the reinforcing layer forming step.

  FIG. 12B shows a configuration in which the reinforcing body 6 is positioned between the reinforcing layer 5 and the outer layer covering body 4, that is, after the reinforcing layer 5 is formed on the covering body 3, the reinforcing body 6 is placed on the reinforcing layer 5. It is an example of the structure formed in. That is, in the reinforcing layer forming step, it is possible to provide the step of forming the reinforcing layer 5 on the covering 3 and then forming the reinforcing member 6 on the reinforcing layer 5.

FIG. 1 is a diagram illustrating a method of manufacturing a catheter tube 10 according to the first embodiment in the order of steps. FIG. 2 is a diagram for explaining a method of measuring the three-point bending performance of a catheter tube. FIG. 3 is a diagram for explaining a method for measuring the buckling performance of a catheter tube by the procedures of (a), (b), and (c). FIG. 4 is a diagram showing an outline of an apparatus for measuring liquid feeding characteristics. FIG. 5 is a diagram showing a method of manufacturing the catheter tube 10 according to the second embodiment in the order of steps. FIG. 6 is a diagram illustrating a method of manufacturing the catheter tube 10 according to the third embodiment in the order of steps. FIG. 7 shows a modification of the first embodiment. FIG. 8 shows another modification of the first embodiment. FIG. 9 shows a modification of the catheter tube having the reinforcing layer of Example 2 or 3, wherein the inner diameter of the distal end portion is reduced, and the hardness and outer diameter of the covering are gradually increased from the proximal side to the distal end. It is a figure which shows the structure which is reducing. FIGS. 10A and 10B show a cross section of the catheter tube having the reinforcing layer of Example 2 or 3, and are an example showing another cross-sectional shape of Example 2 or 3. FIG. FIGS. 11A and 11B show a cross section of a catheter tube including a reinforcing body 6 in the reinforcing layer 5 of Example 3, and are embedded in the covering 3 or the outer covering 4. It is an example. 12 (a) and 12 (b) show a catheter tube including a reinforcing body 6 in the reinforcing layer 5 of Example 3 and a right cross section thereof (the outer cover 4 is not shown). In this example, the positional relationship with the reinforcing body 6 is different from that of the third or fourth embodiment.

Explanation of symbols

2 Core wire 2a Large diameter part 2b Small diameter part 3 Cover body 4 Outer layer cover body 5 Reinforcement layer 6 Reinforcement body 7 Outer layer laminated body 10 Tube 20 for catheter End

Claims (6)

A core wire preparation step of preparing a core wire having a large diameter portion and a small diameter portion;
A covering forming step of forming a covering by coating a synthetic resin on the core wire;
Have a a core removing step of removing the core wire buried in the covering member after the coating formation step,
The covering body forming step includes coating the synthetic resin around the core wire by immersing the core wire in a coating solution in which the synthetic resin is dissolved or dispersed in a predetermined solvent and pulling it up at a predetermined speed. A method for producing a catheter tube as a feature. A core wire preparation step of preparing a core wire having a large diameter portion and a small diameter portion;
A coating forming step of forming a coating member by coating a synthetic resin on the core wire,
A reinforcing layer forming step of forming a reinforcing layer using a metal wire, a resin fiber, or a combination thereof, on at least a part of the covering after the covering forming step,
After the reinforcing layer forming step, an outer layer covering body forming step of forming an outer layer covering body integrally covering the covering body and the reinforcing layer with a thermoplastic resin;
Have a a core removing step of removing the core wire buried in the covering member after the outer cover member forming step,
The covering body forming step includes coating the synthetic resin around the core wire by immersing the core wire in a coating solution in which the synthetic resin is dissolved or dispersed in a predetermined solvent and pulling it up at a predetermined speed. A method for producing a catheter tube as a feature.   The method for manufacturing a catheter tube according to claim 1 or 2, wherein the core wire removing step extracts the core wire from the covering body in a direction of the large diameter portion of the core wire.   The method for producing a catheter tube according to claim 2, wherein the reinforcing layer forming step comprises braiding the covering with a metal wire or a resin fiber at a predetermined interstitial distance.   In the reinforcing layer forming step, a metal wire or a resin fiber is vertically aligned on the covering, and the metal wire or the resin fiber is formed on the covering and the metal wire or the resin fiber at a predetermined interstitial distance. The method for producing a catheter tube according to claim 2, wherein braiding is performed.   In the outer layer covering body forming step, the reinforcing layer forming step is sequentially covered with a thermoplastic tube and a heat shrinkable tube formed of a thermoplastic resin on the covering body and the reinforcing layer, and heated at a predetermined temperature. The method for manufacturing a catheter tube according to claim 2, wherein the thermoplastic tube is removed by peeling off the heat-shrinkable tube after the heat-shrinkable tube is shrunk together with the fusion integration.

Images