JP2014100332A - Catheter tube manufacturing method, continuous body of catheter tubes, and core wire for manufacturing catheter tubes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter tube manufacturing method capable of efficiently removing a core wire while manufacturing catheter tubes using the core wire, and also to provide a continuous body of catheter tubes, and the core wire for manufacturing catheter tubes.SOLUTION: A catheter tube manufacturing method comprises: an internal coat layer body forming step of forming an internal coat layer body 51 by applying a coat of a resin onto a core wire 40 which has a large diameter part 41 and a small diameter part 42 of different external diameters, and in which the ratio of the external diameter of the large diameter part 41 to the external diameter of the small diameter part 42 is 1.31 or less; a stretching step of stretching the core wire 40 in an axial line direction; and a core wire removing step of removing the core wire 40 from the internal coat layer body 51.

Description

  The present invention relates to a catheter tube used for a catheter used in a lumen such as a blood vessel or a body cavity, a continuous body of catheter tubes, and a method for manufacturing a core wire for manufacturing a catheter tube.

  In recent years, treatment in a lumen such as a blood vessel or a body cavity using a catheter has been actively performed for the reason that surgical invasion is very low. For example, a catheter used by being selectively introduced into a complex branching blood vessel in the body is generally pushed selectively along a guide wire introduced into the blood vessel in advance, and a therapeutic drug or A diagnostic contrast medium or the like is distributed from the proximal side (base end side) to the distal end side. For this reason, the long catheter tube that constitutes the catheter increases the rigidity of the proximal end by increasing the inner and outer diameters of the proximal end, and can inject drugs and contrast agents while maintaining sufficient pushability. By securing the characteristics and making the inner and outer diameters on the distal end side thinner than the proximal end side and making it flexible, the reachability to the peripheral blood vessels and the followability to the guide wire are enhanced.

  As a method for manufacturing such a catheter tube, for example, Patent Document 1 discloses that a covering is formed by coating a thermoplastic resin on a core wire in which a large diameter portion and a small diameter portion are continuous at a predetermined interval. A method is described in which a plurality of catheter tubes are formed as a continuous body on the same core wire, then the continuous body is cut together with the core wire for each catheter tube, and the core wire is pulled out and removed to obtain a catheter tube. ing.

JP 2008-183226 A

  However, in the method described in Patent Document 1 described above, depending on the shape of the core wire, it may be difficult to pull out the core wire from the covering.

  The present invention has been made to solve the above-described problems, and a catheter tube manufacturing method capable of efficiently removing a core wire while manufacturing the catheter tube using the core wire, and a catheter tube continuum. It is another object of the present invention to provide a core wire for manufacturing a catheter tube.

  A method of manufacturing a catheter tube that achieves the above object includes a large diameter portion and a small diameter portion having different outer diameters, and the ratio of the outer diameter of the large diameter portion to the outer diameter of the small diameter portion is 1.31 or less. A catheter having a covering body forming step of coating a resin on a core wire to form a covering body, a stretching step of extending the core wire in the axial direction, and a core wire removing step of removing the core wire from the covering body It is a manufacturing method of a tube.

  Since the ratio of the outer diameter of the large-diameter portion to the outer diameter of the small-diameter portion is 1.31 or less, the method for manufacturing the catheter tube configured as described above is effective for the large-diameter portion that is difficult to stretch the core wire. The core wire can be efficiently removed.

  The core wire is obtained by continuously forming the large-diameter portion and the small-diameter portion at a predetermined interval in advance and including the covering body on the core wire after the covering body forming step and before the stretching step. If the tubular continuous body is further cut at a predetermined position of the large-diameter portion and the small-diameter portion to further cut out a plurality of single tubes, the distal end portion and the proximal end portion have different diameters. A tube can be efficiently manufactured using a continuous tubular body. Moreover, even if it is a structure where removal of a core wire is difficult before cutting | disconnection by forming a large diameter part and a thin diameter part in a core wire, a core wire can be easily removed after a cutting process.

  If the core wire has a transition portion between which the outer diameter expands from the small diameter portion to the large diameter portion between the large diameter portion and the small diameter portion, stress is partially concentrated when the core wire is stretched. Without this, the core wire can be efficiently drawn and pulled out.

  If the shape of the outer peripheral surface of the transition portion in the cross section along the axis of the core wire is formed with a curve, the stress is not concentrated on a part when the core wire is stretched, and the core wire is more efficient. It can be drawn and pulled out.

  After the covering body forming step, before the stretching step, further comprising an outer layer covering body forming step of forming an outer layer covering body by coating the resin radially outside the covering body, A catheter tube having a multilayer structure composed of a plurality of layers can be efficiently produced.

  A catheter to be manufactured by further including a reinforcing body forming step of forming a reinforcing body made of a wire on the radially outer side of the covering body after the covering body forming step and before the stretching step. The tube can be reinforced according to the part, and the pushability and kink resistance can be improved.

  A single tube, which is an intermediate body of a catheter tube, is a continuous body of catheter tubes in which a plurality of continuous tubes are formed on the same core wire, and a large-diameter portion and a small-diameter portion having different outer diameters are spaced at predetermined intervals in advance. A core wire formed continuously and having a ratio of the outer diameter of the large diameter portion to the outer diameter of the small diameter portion of 1.31 or less, and a covering formed by coating a resin on the core wire; If the ratio of the outer diameter of the large-diameter portion to the outer diameter of the thin-diameter portion is 1.31 or less, the large-diameter portion that is difficult to extend the core wire can be effectively extended. The core wire can be efficiently removed from the single tube.

  If the core wire of the continuous body of the catheter tube has a transition portion between which the outer diameter expands from the small diameter portion toward the large diameter portion between the large diameter portion and the small diameter portion, the core wire is extended. At this time, the stress is not concentrated on a part, and the core wire can be efficiently drawn and pulled out.

  If the core wire of the continuous body of the catheter tube is formed so that the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire has a curve, stress is generated when the core wire is stretched. Without concentrating on a part, the core wire can be drawn out more efficiently.

  If the continuous body of the catheter tube further includes an outer layer covering body formed of a resin on the outer side in the radial direction than the covering body, a catheter tube having a multilayer structure composed of a plurality of layers can be efficiently obtained. Can be manufactured.

  If the continuous body of the catheter tube further includes a reinforcing body made of a wire on the outer side in the radial direction from the covering body, the manufactured catheter tube can be reinforced according to the part, and the pushability and resistance can be improved. Kink property can be improved.

  A core wire for manufacturing a catheter tube that is continuously formed by covering a single tube that is an intermediate body of a catheter tube, and a large diameter portion and a small diameter portion having different outer diameters are continuously provided at predetermined intervals. If the core wire is for manufacturing a catheter tube having a ratio of the outer diameter of the large diameter portion to the outer diameter of the small diameter portion of 1.31 or less, the large diameter portion with respect to the outer diameter of the small diameter portion When the ratio of the outer diameter is 1.31 or less, it is possible to effectively stretch the large-diameter portion where the core wire is difficult to stretch, and the core wire can be efficiently removed from the single tube.

  If the core wire has a transition portion between which the outer diameter expands from the small diameter portion to the large diameter portion between the large diameter portion and the small diameter portion, stress is partially concentrated when the core wire is stretched. Without this, the core wire can be efficiently drawn and pulled out.

  If the core wire is formed so that the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire has a curved line, the stress is not concentrated on a part of the core wire when the core wire is stretched. Can be drawn more efficiently.

It is a top view which shows a catheter. It is sectional drawing which shows the tube for catheters manufactured by the manufacturing method of the tube for catheters concerning embodiment. It is a figure for demonstrating the manufacturing method of the tube for catheters which concerns on embodiment to process order, (A) is a core wire preparation process, (B) is an inner layer covering body formation process, (C) is a reinforcement body formation process, (D ) Shows an outer layer covering formation step, (E) shows a hydrophilic covering formation step, (F) shows a cutting step, (G) shows a core wire stretching step, and (H) shows a core wire removing step. It is the schematic for demonstrating the method of forming a layer by extrusion molding. It is the schematic for demonstrating the method of forming a layer by dip molding. It is the schematic for demonstrating the method of coat | covering a hydrophilic coating body by dip molding. It is a top view which shows the modification of a core wire. It is a top view which shows the other modification of a core wire.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  A catheter tube 10 manufactured by the catheter tube manufacturing method according to the present embodiment is inserted into a blood vessel, bile duct, trachea, esophagus, urethra, or other living body lumen or body cavity as shown in FIG. It is used for the catheter 1 for performing treatment and diagnosis. The catheter 1 includes a long catheter tube 10, a hub 20 connected to the proximal end of the catheter tube 10, and a kink protector 30 provided at a connection portion between the catheter tube 10 and the hub 20. ing. In this specification, the side to be inserted into the lumen is referred to as “tip” or “tip side”, and the proximal side to be operated is referred to as “base end” or “base end side”.

  As shown in FIGS. 1 and 2, the catheter tube 10 is a tubular member having flexibility, a tube base end portion 11 having a predetermined outer diameter and an inner diameter, and an outer diameter smaller than the tube base end portion 11. And a tube transition portion 13 in which the outer diameter and the inner diameter gradually change in the axial direction between the tube proximal end portion 11 and the tube distal end portion 12. The catheter tube 10 has a lumen 14 formed from the proximal end to the distal end. The lumen 14 functions as a guide wire lumen, for example, and the guide wire is inserted when the catheter 1 is inserted into the living body lumen. The lumen 14 can also be used as a passage for a chemical solution, an embolic material, a contrast medium, or the like.

  The catheter tube 10 is composed of a plurality of layers, an inner layer 15 constituting the innermost layer, a reinforcing layer 16 formed outside the inner layer 15, and an outer layer formed outside the inner layer 15 and the reinforcing layer 16. 17 and a hydrophilic layer 18 coated on the outer side of the outer layer 17. In addition, the structure and material of the inner layer 15, the reinforcement layer 16, the outer layer 17, and the hydrophilic layer 18 are demonstrated in detail by the manufacturing method mentioned later.

  In the hub 20, the proximal end portion of the catheter tube 10 is fixed in a liquid-tight manner by an adhesive, heat fusion, a stopper (not shown) or the like. The hub 20 functions as an insertion port for a guide wire into the lumen 14, an injection port for a drug solution, an embolic material, a contrast medium, etc. into the lumen 14, and also functions as a grip portion when operating the catheter 1. To do. Although the material of the hub 20 is not particularly limited, for example, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer can be suitably used.

  The kink protector 30 is made of an elastic material provided so as to surround the circumference of the catheter tube 10, and suppresses kinking of the catheter tube 10 at a connection portion between the catheter tube 10 and the hub 20. As a material for the kink protector 30, for example, natural rubber, silicone resin, or the like can be preferably used.

  Next, a method for manufacturing the catheter tube 10 according to the present embodiment will be described. The catheter tube 10 includes a core wire preparation step (FIG. 3A) for preparing a long core wire 40, and an inner layer cover body formation step (cover body formation) for forming an inner layer cover body 51 (cover body) on the core wire 40. Step) (FIG. 3B), a reinforcing body forming step for forming the reinforcing body 52 on the inner layer covering body 51 (FIG. 3C), and a tubular continuous body obtained on the core wire 40 after the reinforcing body forming step The outer layer covering 53 is formed by integrally covering the reinforcing body 52 and the inner layer covering 51 with a cutting step (FIG. 3D) for cutting 60 at a predetermined position of the core wire 40 and cutting the single tube 61. The outer layer covering body forming step (FIG. 3E), the core wire extending step for extending the core wire 40 (FIG. 3F), and the core wire removing step for removing the core wire 40 from each single tube 61 (FIG. 3G) ) And a hydrophilic covering forming process for covering the hydrophilic covering 54 (FIG. And (H)), and a. The inner layer covering body 51, the reinforcing body 52, the outer layer covering body 53, and the hydrophilic covering body 54 formed on the core wire 40 are finally the inner layer 15, the reinforcing layer 16, the outer layer 17, and the hydrophilic layer 18 of the catheter tube 10. It becomes.

  As shown in FIG. 3 (A), the core wire preparation step is performed by mechanical processing such as drawing, drawing, or the like using a cutting die, cutting, polishing, grinding, forging, welding, split die, or chemical processing such as etching. , A step of processing to have the large-diameter portion 41, the small-diameter portion 42, and the transition portion 43, or a step of preparing the core wire 40 subjected to the above-described processing by purchase or the like.

  The core wire 40 prepared in the core wire preparation step includes a large diameter portion 41 having a predetermined outer diameter, a small diameter portion 42 having an outer diameter smaller than the large diameter portion 41, and between the large diameter portion 41 and the small diameter portion 42. A plurality of transition portions 43 whose outer diameters gradually change in the axial direction of the core wire 40 are arranged side by side. The ratio of the outer diameter D1 of the large diameter portion 41 to the outer diameter D2 of the small diameter portion 42 (D1 / D2) is preferably more than 1.00 and 1.31 or less, more preferably 1.30 or less. More preferably 1.22 or less. The ratio (D1 / D2) is greater than 1. When the ratio (D1 / D2) is 1.31 or less, not only the small-diameter portion 42 but also the large-diameter portion 41 is satisfactorily stretched in the core wire stretching step, and the thinning of only the small-diameter portion 42 is suppressed. The core wire 40 can be removed well in the removing step, and the catheter tube 10 that can withstand actual use can be manufactured. If the ratio (D1 / D2) is 1.22 or less, the thinning of only the small-diameter portion 42 is more reliably suppressed, and the core wire 40 can be more reliably removed in the core wire removing step. The catheter tube 10 can be manufactured. As an example, the length L1 of the large diameter portion 41 is 1800 mm, the length L2 of the small diameter portion 42 is 150 mm, the length L3 of the transition portion 43 is 50 mm, and the outer diameter D1 of the large diameter portion 41 is 0.55 to. Although the outer diameter D2 of 6 mm and the thin diameter part 42 can be 0.45-0.50 mm, a dimension is not limited to this.

  The material of the core wire 40 can be a metal such as a copper wire or a stainless steel soft wire, or a resin strand such as polyamide (PA), and the cross section is not limited to a circle, but can be any shape such as an ellipse, a semicircle, a polygon, etc. It can be made into the shape. The core wire 40 as described above can be easily prepared by purchase or the like.

  After the core wire preparation step, as shown in FIG. 3 (B), an inner layer covering 51 is formed on the core wire 40 (inner layer covering forming step). As the material of the inner layer covering 51, a thermoplastic resin, a thermosetting resin, or the like can be applied, and a low friction material such as a fluorine-based resin or high-density polyethylene (HDPE) is preferable.

  The inner layer covering 51 may be mixed with a radiopaque material. When the inner layer covering 51 is formed of a low friction material such as a fluororesin, the outer surface of the inner layer covering 51 is roughened by chemical etching or the like so that other materials can be covered on the outer side. It is preferable to perform the treatment.

  When a thermoplastic resin is used as the material of the inner layer covering 51, it can be extruded at a predetermined take-up speed at a predetermined molding temperature (die temperature) with an extruder. Thereby, the extrusion molding (inner layer covering 51) of substantially the same thickness can be obtained. As an example, the outer diameter of the inner layer covering 51 in the portion corresponding to the large diameter portion 41 is 0.57 to 0.76 mm, and the outer diameter of the inner layer covering 51 in the portion corresponding to the small diameter portion 42 is 0.47 to 0. 0.53 mm, but the dimensions are not limited to this. In addition, by adjusting the take-up speed, the wall thickness can be changed according to the part.

  An outline of the extrusion molding method is as follows. Using a general extrusion molding machine 100 as shown in FIG. 4, a thermoplastic resin layer (here, inner layer covering 51) on the core material W (here, the core wire 40). ). The extrusion molding machine 100 includes an extruder 101 for extruding the heated and melted material, a mold 103 for extruding the resin extruded from the extruder 101 from the extrusion port 102, and a position passing through the mold 103 at the center of the extrusion port 102. A take-up machine 105 for picking up the core material W to be wound, a supply roll 106 for supplying the core material W to the mold 103 while the core material W is wound and held, and a recovery for recovering the core material W that has been extruded. A roll 107. When extruding a material onto the core material W, the material heated and melted by the extruder 101 is supplied to the mold 103, and sent from the supply roll 106 to take out the core material W located at the extrusion port 102. The material is continuously supplied from the extrusion port 102 onto the core material W while being taken up by 105, and the material is coated on the core material W. The core material W coated with the material is wound around the collection roll 107 and collected after the coated material is solidified. By changing the take-up speed by the take-up machine 105, the outer diameter of the extruded product can be arbitrarily changed. If the core material W is directly received from the previous process and the core material W coated with the thermoplastic resin is directly transferred to the subsequent process, the supply roll 106 and the recovery roll 107 may not be provided. In the extrusion molding of the inner layer covering 51, when a fluororesin (such as PTFE) is used as the resin, it is possible to extrude a mixture of resin powder with a fluorolubricant as an auxiliary agent.

  In the inner layer covering body forming step, the inner layer covering body 51 may be formed by dip molding, not by extrusion molding.

  If the method by dip molding is outlined, first, in a container 200 as shown in FIG. 5, a solution R in which a resin as a material is dissolved in a solvent or a dispersion R in which a dispersion R is dispersed in a diluent is contained. Supply roll on which the core material W is wound and held via a flexible valve body 201 through which the core material W (here, the core wire 40) can be inserted while maintaining liquid tightness. The core material W is supplied from 202, and the core material W is inserted into the container 200 from below. Then, after the core material W is dipped (immersed) in the solution R or dispersion R in the container 200, the core 200 is pulled out above the container 200. As a result, the solution R or dispersion R is adhered to the outer peripheral surface of the core material W, and the solution R or dispersion R adhered to the core material W is heated and dried with hot air, a heater, etc. When the dispersion R is used, the inner layer covering 51 is formed by further sintering. The core material W coated with the material is wound around the collection roll 203 and collected after the coated material is solidified. As the solvent and diluent, those usually used can be applied. By changing the pulling speed from the container 200, the film thickness of the solution R or the dispersion R attached to the core material W can be arbitrarily changed, and the thickness of the inner layer covering 51 can be arbitrarily changed. The film thickness is determined by the interaction of the density, surface tension, viscosity, gravity and pulling speed of the solution R or dispersion R. When the pulling speed from the container 200 is decreased, the solution R attached to the core W is reduced. Alternatively, the film thickness of the dispersion R can be increased, and when the pulling rate is increased, the film thickness of the solution R or the dispersion R attached to the core material W can be decreased.

  Also, if the viscosity of the solution R or dispersion R is high, the coating thickness tends to be non-uniform, so the viscosity is set low enough to make the coating film thickness uniform, and dip molding is repeated multiple times. Thus, the coating thickness can be gradually increased, and the coating thickness can be controlled with high accuracy. When the dip molding is repeatedly performed, the recovery roll 203 from which the core material W coated with the material is recovered can be moved below the container 200 to be the supply roll 202, and the dip molding can be performed again. When the dip molding is repeated, it is preferable to dry and sinter the solution R or the dispersion R by heating with hot air or a heater every time.

  Further, when the dip molding is repeated a plurality of times, it is preferable that the dip molding is performed at least once in the opposite direction, rather than the dip molding by pulling up in the same direction of the core wire 40, more preferably once. It is preferable to perform dip molding while changing the direction one by one. By dipping from the opposite direction at least once, the film thickness can be made uniform by suppressing the unevenness of the film thickness depending on the pulling direction. The thickness deviation can be suppressed to the maximum and the film thickness can be made more uniform. In particular, in the core wire 40 whose outer diameter changes, the thickness 40 depending on the pulling direction is likely to occur in the portion where the outer diameter changes, so the core wire 40 in which the large diameter portion 41 and the small diameter portion 42 are formed. When the dip molding is performed, the dip molding is performed at least once from the opposite direction, so that a high effect can be achieved in making the film thickness uniform. In addition, although it can dry and sinter for every step of dip forming, it can also be dried and sintered after dip forming continuously several times without drying and sintering. Thus, the thickness in a desired part can be finely set by carrying out the dip molding continuously several times without drying and sintering.

  Further, when the dip molding is repeatedly performed, the number of repetitions can be changed according to the portion of the core wire 40. As an example of a method for this purpose, the portion where the number of repetitions is to be increased is pulled up, the solution R or dispersion R coated on the portion is dried and sintered, and then the core wire 40 that has moved upward is moved downward. And the part where the number of repetitions is to be increased is immersed in the solution R or the dispersion R. Thereafter, the core wire 40 is again moved upward, and the part where the number of repetitions is desired to be increased is again pulled up, so that the solution R or the dispersion R can be further coated. By repeating this, dip molding can be performed a desired number of repetitions according to the site. In this way, the number of repetitions of dip molding can be set as appropriate according to the site while switching the moving direction of the core wire 40. Therefore, for example, the number of repetitions of dip molding can be set so that transition portion> large diameter portion> small diameter portion or large diameter portion> transition portion> small diameter portion. A> B means that the number of repetitions in A is larger than the number of repetitions in B. Of these, it is preferable to perform dip molding so that the number of repetitions is maximized at the transition portion, because the thickness at the transition portion can be variably changed. Even in this method, drying and sintering can be performed for each step of dip molding, but drying and sintering may be performed after dip molding multiple times in succession without drying and sintering. .

  In addition, the core 40 is not moved, but the depth is changed by changing the amount H of the solution R or dispersion R shown in FIG. (Downward) can also be adjusted.

  In addition, the core material W is lifted from the container 200 while being rotated about the axis of the core material W, so that centrifugal force is applied to the solution R or dispersion R coated on the core material W to be coated. Can be changed arbitrarily. That is, the higher the rotational speed of the core material W, the greater the centrifugal force that acts, so that the film thickness of the solution R or dispersion R coated on the core material W can be reduced. The slower the centrifugal force acting, the more the film thickness of the solution R or dispersion R coated on the core material W can be increased. For example, the thickness of the fifth covering portion 70 </ b> E covered by the small diameter portion 42 is increased by increasing the rotational speed at the time of pulling up the small diameter portion 42 than when the large diameter portion 41 is pulled up. It can be made thinner than the film thickness of 70 A of 1st coating parts coat | covered by. When the transition portion 43 is pulled up, the rotational speed of the core wire 40 is gradually changed, so that the film thickness of the third covering portion 70C in the transition portion 43 is smooth between the large diameter portion 41 and the small diameter portion 42. And it can be changed in an inclined manner. Thereby, the distal end side of the manufactured catheter tube 10 can be made more flexible than the proximal end side. In addition, the larger the outer diameter of the core wire 40, the greater the centrifugal force that acts. Therefore, in order to make the film thickness of the solution R or dispersion R to be coated constant, the rotational speed is adjusted at the portion where the outer diameter changes. It is also possible to do.

  In the present embodiment, since the core material W is supplied from the supply roll 202 and is recovered by the recovery roll 203, the supply roll 202 and the recovery roll 203 can be rotated about the axis of the core material W in the container 200. However, the configuration of the apparatus is not limited as long as the core material W in the container 200 can be rotated.

  Further, when the core material W is pulled up from the container 200 while rotating, if a mixture of particles, fibers, and the like is mixed in the solution R or the dispersion R, the mixture can be oriented.

  When the dip forming is repeated a plurality of times while rotating, it is preferable to perform the dip forming while rotating the core wire 40 in the same direction each time instead of rotating at least once. It is preferable to perform dip molding while reversing the direction. By performing dip molding while rotating in reverse at least once, the film thickness can be made uniform by suppressing the deviation of film thickness depending on the rotation direction, and by rotating the rotation direction by changing the rotation direction one by one. The film thickness deviation depending on the thickness can be suppressed to the maximum, and the film thickness can be made more uniform.

  When it is desired to reduce the film thickness of the solution R or the dispersion R coated on the core material W, it is necessary to slow the pulling speed if it is controlled by the pulling speed. If it is controlled by speed, it can be adjusted by increasing the rotational speed without slowing the pulling speed, so that the manufacturing time can be shortened.

  Thus, the viscosity of the solution R or the dispersion R, the pulling speed, the pulling direction, the pulling site, the liquid amount of the solution R or the dispersion R (depth in the container 200), the number of repetitions of dip molding, the rotation speed, and By adjusting the rotation direction, the coating thickness and manufacturing time of the inner layer covering 51 to be coated can be controlled with high accuracy.

  In addition, if the inner layer covering 51 can be dip-molded, the container 200 does not have to be as described above. For example, the core material W is not inserted through the bottom of the container 200 but from above the container. May be dipped (immersed) in the solution R or the dispersion R, and the core material W may be curved and pulled up again. Further, after the solution R or the dispersion R is attached to the outer peripheral surface of the core material W, the amount of the solution R or the dispersion R to be attached is regulated by passing through a die (not shown) having a predetermined inner diameter. Thus, the outer diameter of the inner layer covering 51 can be adjusted. Further, if the core material W is directly received from the previous process and the core material W coated with the material is directly transferred to the subsequent process, the supply roll 202 and the recovery roll 203 around which the core material W is wound are not provided. May be.

  Further, the method for forming the inner layer covering 51 in the inner layer covering forming step is not limited to extrusion molding or dip molding. For example, a solution in which a resin is dissolved in a solvent or a dispersion in which a dispersion is dispersed in a diluent is sprayed. (Spray), application, printing, etc., after attaching to the core wire 40, the solution or dispersion attached to the core wire 40 is heated and dried with hot air or a heater, and depending on the material, it may be sintered. The inner layer covering 51 may be formed.

  After the inner layer covering body forming step, as shown in FIG. 3C, the reinforcing body 52 is formed so as to cover at least a part on the inner layer covering body 51 (reinforcing body forming step). Thereby, the tubular continuous body 60 including the inner layer covering body 51 and the reinforcing body 52 is formed on the core wire 40.

  The reinforcing body 52 is formed on the inner layer covering body 51 by continuously winding a strand with a braid having a predetermined interstitial distance. The reinforcing body 52 may be wound with strands while changing the winding direction, such as horizontal winding in the same direction, right-hand winding, left-hand winding, etc., and the winding pitch, interstitial distance, inclination angle with respect to the circumferential direction, etc. The configuration may be changed, and the configuration is not particularly limited.

  As the strands used for the reinforcing body 52, metal wires such as platinum (Pt) / tungsten (W), resin fibers, carbon fibers, glass fibers and the like can be applied, or a plurality of these strands may be used in combination. .

  After the reinforcing body forming step, as shown in FIG. 3D, the tubular continuous body 60 composed of the inner layer covering body 51 and the reinforcing body 52 is cut together with the core wire 40 at a predetermined position (cutting step). The tubular continuous body 60 includes a first cutting portion 63 close to one end of the large diameter portion 41 and a second cutting portion on the small diameter portion 42 close to the first cutting portion 63 across the transition portion 43. 64 and cut. Thereby, the single tube 61 from which the large diameter part 41 is cut long and the surplus tube 62 from which the large diameter part 41 is cut short are formed. The surplus tube 62 is removed as an unnecessary portion. As an example, in the single tube 61, the length of the portion corresponding to the large diameter portion 41 of the core wire 40 is 1600 mm, and the length of the portion corresponding to the small diameter portion 42 of the core wire 40 is 100 mm. In addition, the large diameter part 41 and the small diameter part 42 of the core wire 40 can be set long so that the surplus tube 62 has the same shape as the single tube 61, and the surplus tube 62 can also be used as the single tube 61.

  In the cutting step, for example, a cutting blade is used to cut with a shearing machine or the like, but any cutting method may be used as long as it can cut the core wire 40 and the covering (the inner layer covering 51 and the reinforcing body 52).

  After the cutting step, as shown in FIG. 3E, at least a part of the reinforcing body 52 is covered on the outer surface of the single tube 61 to form the outer layer covering 53 (outer layer covering forming step). . As an example, the outer diameter of the outer layer covering 53 in a portion corresponding to the large diameter portion 41 is 0.8 mm to 1.1 mm, and the outer diameter of the outer layer covering 53 in a portion corresponding to the small diameter portion 42 is 0.6 mm to 1. 0.0 mm. The outer diameter of the outer layer covering 53 at the portion corresponding to the transition portion 43 gradually changes and can be 0.6 mm to 1.1 mm.

  The material of the outer layer covering 53 is, for example, polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, Polymer materials such as polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture thereof can be applied. The outer layer covering 53 may be mixed with a radiopaque material.

  When a thermoplastic resin is used as the material of the outer layer covering 53, the outer layer covering 53 may be extruded using the above-described extrusion molding machine 100 as shown in FIG. it can.

  Further, in the outer layer covering body forming step, the outer layer covering body 53 is not formed by extrusion molding, but the outer layer covering body 53 is formed by using the container 200 as shown in FIG. Further, it can be formed by the dip forming described in the inner layer covering forming process. In the outer layer covering body forming step, the core material W is not a continuous body but is cut corresponding to one portion of the catheter tube 10, so that it is not inserted from the valve body 201, but is lowered from above. It can also be pulled up after dip molding.

  The method of forming the outer layer covering 53 in the outer layer covering forming step is not limited to extrusion molding or dip molding. For example, a solution in which a resin is dissolved in a solvent or a dispersion in which a resin is dispersed in a diluent is sprayed. (Spray), application, printing, and the like, after attaching to the outer peripheral surface of the reinforcing body 52, the attached solution or dispersion is heated and dried with hot air or a heater, and depending on the material, it may be sintered. Thus, the outer layer covering 53 may be formed.

  Moreover, in order to form the outer layer covering 53 in the outer layer covering forming step, it is also possible to use a heat-shrinkable tube that contracts into a memorized shape by heating. The heat shrinkable tube is, for example, a fluorine resin. When using a heat-shrinkable tube, first, as shown in FIG. 6A, a tube body 70 having an inner diameter larger than the outer diameter of the single tube 61 is prepared, and the tube body 70 is covered with the single tube 61. Thereafter, as shown in FIG. 6 (B), a heat-shrinkable tube 71 is placed on the outer side. The tube body 70 is a material that becomes the outer layer covering body 53. Next, as shown in FIG. 6C, the heat shrinkable tube 71 is contracted while being heated or heated by hot air or a heater to soften or melt the tube 70, and the tube 70 is contracted by the contraction force of the heat shrinkable tube 71. Can be formed as an outer layer covering 53 by pressing the outer periphery of the reinforcing body 52 and the inner layer covering 51. As shown in FIG. 6D, the heat-shrinkable heat-shrinkable tube 71 is removed after the tube body 70 is formed as the outer layer covering body 53 around the outer periphery of the reinforcing body 52 and the inner layer covering body 51. In FIG. 6, there is one tube body 70 to be the outer layer covering body 53, but it may be divided into a plurality of parts in the axial direction, and in this case, each is formed with different materials, characteristics, or dimensions. Various designs are possible.

  Thus, unlike the case where the outer layer covering 53 is formed on the tubular continuous body 60 that is not cut, the method of forming the outer layer covering 53 is limited because the outer layer covering forming step is performed after the cutting step. Not. In particular, the method of forming the outer layer covering 53 using the heat-shrinkable tube 71 by covering the tubular body 70 is because the tubular body 70 cannot be covered by the tubular continuous body 60 in which a plurality of single tubes 61 are connected. On the other hand, when the outer layer covering forming process is performed after the cutting process, the tube body 70 having various materials, characteristics, or shapes can be applied, and the design flexibility is improved.

  In addition, you may remove a part of reinforcement body 52 before an outer layer covering body formation process. For example, in order to ensure the flexibility of the tube distal end portion 12 of the catheter tube 10, a portion on the distal end side of the reinforcing body 52 corresponding to the small diameter portion 42 can be removed. Moreover, the outer layer covering body forming step may be performed before the cutting step.

  After the outer layer covering forming step, as shown in FIG. 3 (F), a part of the covering at both ends of the core wire 40 cut in the cutting step is removed, and a part of both ends of the core wire 40 is exposed. To the drawing machine and the whole core wire 40 is drawn (core wire drawing step). Thereafter, as shown in FIG. 3G, the core wire 40 is pulled out from the large diameter portion 41 side (core wire removing step). In addition, after extending | stretching until the core wire 40 fractures | ruptures in the small diameter part 42 with an extending | stretching machine, you may pull out the broken core wire 40 from the large diameter part 41 side and the both sides of the small diameter part 42. Further, the core wire 40 may be stretched and pulled out after the cutting step and before the outer layer covering body forming step.

  After the core wire removing step, as shown in FIG. 3 (H), a hydrophilic polymer substance (on the part corresponding to the small diameter part 42 and the part corresponding to the large diameter part 41 of the outer layer covering 53) is formed. A hydrophilic coating 54 is formed by coating the hydrophilic material (hydrophilic coating forming step). Thereby, manufacture of the tube 10 for catheters is completed. The hydrophilic covering 54 (hydrophilic layer 18) on the outer surface of the catheter tube 10 exhibits lubricity when in contact with a liquid such as blood or physiological saline, and the friction resistance of the catheter tube 10 is reduced. Further, the slidability is further improved. As a result, the operability of insertion is further improved, and the pushability, followability, kink resistance and safety are further improved.

  Further, when inserting the catheter tube 10 into a blood vessel, it is necessary to operate the catheter tube 10 by holding the proximal end side of the catheter tube 10 in a hand. For this reason, if the base end side of the catheter tube 10 slips when held by hand, the operability is lowered, which is not preferable. Therefore, the range in which the hydrophilic polymer substance in the longitudinal direction of the catheter tube 10 is applied is a predetermined length (for example, about 150 to 500 mm) from the proximal end of the catheter tube 10 toward the distal end. It is preferable to impart a hydrophilic polymer substance to the region excluding.

  Examples of the hydrophilic polymer substance include the following natural or synthetic polymer substances or derivatives thereof. In particular, cellulosic polymer materials (eg, hydroxypropyl cellulose), polyethylene oxide polymer materials (polyethylene glycol), maleic anhydride polymer materials (eg, maleic anhydride such as methyl vinyl ether maleic anhydride copolymer) Copolymers), acrylamide polymer substances (for example, polyacrylamide), and water-soluble nylon (for example, AQ-nylon P-70 manufactured by Toray Industries, Inc.) are preferable because a low friction coefficient can be stably obtained. Among these, a maleic anhydride polymer material is more preferably used. Further, the derivative of the polymer substance is not limited to a water-soluble derivative, and there is no particular limitation as long as the polymer substance has a basic configuration, and even if it is insolubilized, the molecular chain has a degree of freedom. As long as it has water and contains water.

  In order to fix such a hydrophilic polymer substance to the outer surface of the catheter tube 10, it is covalently bonded to a reactive functional group present or introduced in the outer layer covering 53 or on the surface of the outer layer covering 53. It is preferable to carry out. Thereby, a continuous lubricating surface can be obtained.

  The reactive functional group present in or introduced into the outer layer covering 53 or on the surface thereof may be any one that reacts with the hydrophilic polymer substance and is fixed by being bonded or cross-linked, such as a diazonium group. , Azide group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group, carboxyl group, epoxy group, hydroxyl group, aldehyde group, and the like. Among these, as the reactive functional group, an isocyanate group, an amino group, an aldehyde group, and an epoxy group are more preferable.

  The hydrophilic covering forming step may be performed after the outer layer covering forming step and before the core wire stretching step or the core wire removing step. The hydrophilic covering forming step may be performed after the hub 20 and the kink protector 30 are connected to the manufactured catheter tube 10.

  As described above, the manufacturing method of the catheter tube 10 according to the present embodiment includes the large diameter portion 41 and the small diameter portion 42 having different outer diameters, and the outer diameter of the large diameter portion 41 with respect to the outer diameter of the small diameter portion 42. An inner layer covering body forming step (covering body forming step) in which a resin is coated on the core wire 40 having a ratio of 1.31 or less to form an inner layer covering body 51 (covering body), and the core wire 40 is stretched in the axial direction. A stretching step and a core wire removing step of removing the core wire 40 from the inner layer covering body 51. Thus, since this manufacturing method uses the core wire 40 whose outer diameter ratio of the large-diameter portion 41 to the outer diameter of the small-diameter portion 42 is 1.31 or less, the large-diameter portion 41 in which the core wire 40 is difficult to stretch is also provided. It can be effectively stretched together with the small diameter portion 42, the core wire 40 can be efficiently removed, and the yield can be improved.

  In addition, as a method for producing the catheter tube 10, a hot stretching process is generally performed in which a tube body is subjected to a hot stretching process, and the inner and outer diameters are reduced from the proximal side to the distal side. When hot-stretching is performed, residual strain due to hot-stretching is affected during hot-melt processing, such as when attaching a soft tip or contrast marker, and the inner and outer diameters near the melted part become thicker, resulting in poor dimensional accuracy. As a result, there are problems such as a decrease in yield. On the other hand, according to the manufacturing method according to the present embodiment, since the hot stretching process is not performed, there is no distortion due to stretching, the workability is improved, and as a result, the cost is reduced. In addition, since the winding pitch of the reinforcing body 52 (interstitial distance in the case of braiding) does not increase due to stretching, the tip portion is excellent in flexibility and kink resistance.

  Further, the core wire 40 has a large-diameter portion 41 and a small-diameter portion 42 formed in advance continuously at a predetermined interval, and after the inner layer covering forming step and before the stretching step, the inner layer covering on the core wire 40. 51 is further provided with a cutting step of cutting the plurality of single tubes 61 by cutting the tubular continuous body 60 obtained by including the large diameter portion 41 and the small diameter portion 42 at predetermined positions. The catheter tube 10 having different diameters can be efficiently manufactured using the continuous tubular body 60 that is continuously connected. Further, the core wire 40 can be easily removed after the cutting process even if the core wire 40 is formed with the large diameter portion 41 and the small diameter portion 42 so that the core wire 40 is difficult to remove before cutting. The catheter tube 10 with the large-diameter tube proximal end portion 11 as the proximal end and the small-diameter tube distal end portion 12 as the distal end side has a flexible distal end portion without impairing the pushability and liquid feeding characteristics of the proximal end portion. The guide wire followability and kink resistance are excellent.

  Moreover, since the core wire 40 has the transition part 43 in which an outer diameter expands toward the large diameter part 41 from the small diameter part 42 between the large diameter part 41 and the small diameter part 42, when extending the core wire 40, stress is stretched. The core wire 40 can be efficiently stretched and pulled out without being concentrated in part.

  Further, since the outer layer covering body forming step of forming the outer layer covering body 53 by coating the resin radially outside the inner layer covering body 51 after the inner layer covering body forming step and before the stretching step, The catheter tube 10 having a multilayer structure composed of a plurality of layers can be efficiently manufactured using the core wire 40.

  In addition, the catheter is manufactured because it further includes a reinforcing body forming step of forming a reinforcing body 52 made of a wire material on the radially outer side of the inner layer covering body 51 before the stretching step after the inner layer covering body forming step. The tube 10 can be reinforced according to the site, and the pushability and kink resistance can be improved.

  Further, a continuous body 65 of catheter tubes in which a plurality of single tubes 61, which are intermediate bodies of the catheter tube 10, are continuously formed on the same core wire 40, includes a large diameter portion 41 and a small diameter portion 42 having different outer diameters. Are formed continuously in advance at a predetermined interval, and the ratio of the outer diameter of the large-diameter portion 41 to the outer diameter of the small-diameter portion 42 is 1.31 or less, and the core wire 40 is coated with a resin. Since the ratio of the outer diameter of the large-diameter portion 41 to the outer diameter of the small-diameter portion 42 is 1.31 or less, the core wire 40 is difficult to be stretched. The diameter portion 41 can be effectively extended together with the small diameter portion 42, and the core wire 40 can be efficiently removed from the single tube 61.

  In addition, a core tube 40 for manufacturing a catheter tube that is continuously formed by covering a single tube 61 that is an intermediate body of the catheter tube 10 has a large-diameter portion 41 and a small-diameter portion 42 having different outer diameters in advance. Since the ratio of the outer diameter of the large-diameter portion 41 to the outer diameter of the small-diameter portion 42 is 1.31 or less formed continuously at a predetermined interval, the large-diameter portion 41 of the core wire 40 that is difficult to be stretched is also small-diameter. It can be effectively stretched together with the portion 42, and the core wire 40 can be efficiently removed from the single tube 61.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, in the present embodiment, the large diameter portion 41 and the small diameter portion 42 are continuously formed on the core wire 40 at a predetermined interval. However, the core wire 40 may not be formed continuously. Only the catheter tube 10 may be manufactured.

  Further, a transition portion 83 between the large diameter portion 81 and the small diameter portion 82 may be provided only on one end side of the large diameter portion 81 as in a core wire 80 as a modified example shown in FIG. Thereby, the length of the surplus tube (see the surplus tube 62 in FIG. 3F) to be removed after cutting is shortened, and the cost can be reduced and the manufacturing area can be saved.

  Moreover, at least a part of the shape of the outer peripheral surface of the transition portion 93 in the cross section along the axis of the core wire 90 may be formed as a curve, like a core wire 90 as another modified example shown in FIG. Thereby, the rigidity of the manufactured catheter tube changes smoothly and in an inclined manner along the axis, local bending is suppressed, and a catheter tube excellent in pushability and kink resistance can be manufactured. Further, when the core wire 90 is stretched, stress is not concentrated on a part, and the core wire 90 can be efficiently stretched and pulled out. In FIG. 8, the inclination angle X of the outer peripheral surface of the transition portion 93 in the cross section along the axis of the core wire 90 gradually increases from the small diameter portion 92 toward the large diameter portion 91. It becomes the maximum, and gradually becomes smaller as it gets closer to the large-diameter portion 91. By setting it as such a shape, the rigidity along the axis line between the large diameter part 91 and the small diameter part 92 can be changed more smoothly and in an inclined manner, local bending is suppressed, pushability and A catheter tube excellent in kink resistance can be manufactured. Further, when the core wire 90 is stretched, the stress is further dispersed, and the core wire 90 can be efficiently stretched and pulled out.

  Further, the cross-sectional shape of the catheter tube in the cross section perpendicular to the axis may not be circular, and may be, for example, elliptical. Further, the lumen in the catheter tube may not have a circular cross-sectional shape in the cross section perpendicular to the axis, and may be, for example, an elliptical shape or a semicircular shape. The catheter tube may be provided with a plurality of lumens.

  Further, the reinforcing body 52 may not be provided between the inner layer covering body 51 and the outer layer covering body 53, and may be provided on the outer side in the radial direction of the outer layer covering body 53, for example. In addition, each of the reinforcing body 52, the outer layer covering body 53, and the hydrophilic covering body 54 may not be provided.

  Further, at least one of the inner layer covering 51 and the outer layer covering 53 may be irradiated with an electron beam or gamma ray to crosslink the material to increase the hardness. Further, at least one of the inner layer covering body 51 and the outer layer covering body 53 may be subjected to a softening process for reducing the hardness using an acid or an alkali.

  Further, a radiopaque marker is disposed between the inner layer covering 51 and the reinforcing body 52, between the reinforcing body 52 and the outer covering 53, or between the outer covering 53 and the hydrophilic covering 54. Also good.

  Example 1 in which the length L1 of the large diameter part is 1800 mm, the length L2 of the small diameter part is 150 mm, the length L3 of the transition part is 50 mm, and the large diameter part and the small diameter part are continuously formed Using the four types of core wires as Example 2, Example 3, and Comparative Example 1, an experiment was conducted in which the core wires were pulled out from the covering formed on the core wires. The core wire material was copper. The ratio of the outer diameter of the large-diameter portion to the outer diameter of the large-diameter portion, the outer diameter of the small-diameter portion, and the outer diameter of the small-diameter portion in Example 1, Example 2, Example 3, and Comparative Example 1 is shown in the table below. As shown.

  The inner layer covering to be covered with the core wire is formed by dipping using PTFE as a material, and the thickness of the portion corresponding to the large-diameter portion is 0.015 mm in any of the examples and comparative examples. The thickness of the portion corresponding to the small diameter portion was set to 0.01 mm.

  The reinforcing body provided on the inner layer covering was formed so as to cover the entire inner layer covering by using a strand made of stainless steel as a material.

  The outer layer covering body provided on the radially outer side of the inner layer covering body and the reinforcing body is formed by extrusion molding using a polyester elastomer as a material, and the thickness of the portion corresponding to the large diameter portion in any of the examples and the comparative examples. The thickness was 0.10 mm, and the thickness of the portion corresponding to the small diameter portion was 0.05 mm.

  After forming the inner layer covering body, the reinforcing body and the outer layer covering body on the core wire, it is cut together with the core wire at the large diameter portion and the small diameter portion, and the length of the portion corresponding to the large diameter portion is 1600 mm, corresponding to the small diameter portion A single tube having a length of 100 mm was cut out. Thereafter, a part of the covering at both ends of the core wire was removed to expose a part of both ends of the core wire, and then the entire core wire was stretched. Thereafter, an attempt was made to pull out the core wire from the large diameter portion side. The results are shown in the table below. As shown in the table below, Example 1 and Example 2 in which the ratio (outer diameter of the large diameter portion / outer diameter of the small diameter portion) is 1.22, the ratio (outer diameter of the large diameter portion / outer diameter of the small diameter portion). ) Was 1.31, the core wire could be satisfactorily pulled out, but in Comparative Example 1 where the ratio (outer diameter of the large diameter portion / outside diameter of the small diameter portion) was 1.38, the core wire was Could not be pulled out.

1 catheter,
10 Catheter tube,
40, 80, 90 core wires,
41, 81, 91 Large diameter part,
42, 82, 92 Small diameter part,
43, 83, 93 Transition section,
51 Inner layer covering (covering body),
52 reinforcements,
53 outer layer covering,
54 hydrophilic covering,
60 tubular continuum,
61 Single tube,
63 1st cutting part,
64 second cutting part,
65 A continuum of catheter tubes.

Claims (14)

A covering is formed by coating a resin on a core wire having a large diameter portion and a small diameter portion having different outer diameters, and the ratio of the outer diameter of the large diameter portion to the outer diameter of the small diameter portion being 1.31 or less. A covering body forming step,
A stretching step of stretching the core wire in the axial direction;
And a core wire removing step of removing the core wire from the covering. In the core wire, the large-diameter portion and the small-diameter portion are continuously formed at a predetermined interval in advance,
After the covering body forming step and before the stretching step, a tubular continuous body obtained by providing the covering body on the core wire is cut at a predetermined position of the large diameter portion and the small diameter portion, and a plurality of the continuous body is obtained. The manufacturing method of the tube for catheters of Claim 1 which further has the cutting process which cuts out a single tube.   The said core wire is a manufacturing method of the tube for catheters of Claim 1 or 2 which has the transition part which an outer diameter spreads toward a large diameter part from a small diameter part between the said large diameter part and a small diameter part.   The method for manufacturing a catheter tube according to claim 3, wherein the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire has a curve.   The outer layer covering body formation process which coat | covers resin on the radial direction outer side rather than the said covering body and forms an outer layer covering body after the said covering body formation process and before the said extending | stretching process is further included. The manufacturing method of the tube for catheters of any one of these.   Any one of Claims 1-5 which further has the reinforcement body formation process which forms the reinforcement body which consists of a wire material in the radial direction outer side rather than the said covering body before the said extending | stretching process after the said covering body formation process. The manufacturing method of the tube for catheters of claim | item. A single tube that is an intermediate body of a catheter tube is a continuous body of catheter tubes in which a plurality of continuous tubes are formed on the same core wire,
A core wire in which a large diameter portion and a small diameter portion having different outer diameters are continuously formed in advance at a predetermined interval, and a ratio of an outer diameter of the large diameter portion to an outer diameter of the small diameter portion is 1.31 or less;
A continuous body of a catheter tube having a covering formed by coating a resin on the core wire.   The said core wire is a continuous body of the catheter tube of Claim 7 which has the transition part which an outer diameter spreads toward a large diameter part from a small diameter part between the said large diameter part and a small diameter part.   The continuous body of the catheter tube according to claim 8, wherein the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire has a curve.   The continuous body of the tube for catheters of any one of Claims 7-9 which further has the outer-layer coating body formed with resin in the radial direction outer side rather than the said coating body.   The continuous body of the tube for catheters of any one of Claims 7-10 which further has the reinforcement body which consists of a wire on the radial direction outer side rather than the said coating | coated body. A core wire for manufacturing a catheter tube that is continuously formed by coating a single tube that is an intermediate body of a catheter tube,
A catheter tube in which a large-diameter portion and a small-diameter portion having different outer diameters are continuously formed in advance at predetermined intervals, and the ratio of the outer diameter of the large-diameter portion to the outer diameter of the small-diameter portion is 1.31 or less. Manufacturing core wire.   The said core wire is a core wire for manufacture of the tube for catheters of Claim 12 which has a transition part which an outer diameter expands toward a large diameter part from a small diameter part between the said large diameter part and a small diameter part.   The core wire for manufacturing a catheter tube according to claim 13, wherein the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire has a curve.

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