JP2014100333A - 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 improving a push-in property and kink resistance by smoothly changing the rigidity of catheter tubes in an axial line direction, 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: a coat 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 also has a first transition part 43 from the large diameter part 41 to the small diameter part 42 where the external diameter reduces, and the shape of a cross section of an outer peripheral surface of the first transition part 43 along an axial line of the core wire 40 exhibiting a curve whose inclination continuously changes from the large diameter part 41 and the small diameter part 42; 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 method for producing a catheter tube used in a catheter used in a lumen such as a blood vessel or a body cavity, a continuous catheter tube, and a core wire for producing 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 that is selectively introduced into a complicatedly branched blood vessel in the body is generally pushed selectively along a guide wire that is introduced into the blood vessel in advance, and is used for therapeutic drugs or diagnostics. The contrast medium or the like is circulated from the proximal side (base end side) to the distal end side. For this reason, the long catheter tube that constitutes the catheter has a large inner and outer diameter on the proximal side, thereby increasing the rigidity and providing sufficient pushability while maintaining the injection characteristics of drugs and contrast agents. And the inner and outer diameters on the distal end side are made thinner than the proximal end side, making it flexible, thereby improving the reachability to the peripheral blood vessels and the followability to the guide wire.

  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 of manufacturing a catheter tube by forming a plurality of catheter tubes as a continuous body on the same core wire, then cutting the continuous body together with the core wire for each catheter tube, and drawing and removing the core wire is described. Has been.

JP 2008-183226 A

  However, in the method described in Patent Document 1 described above, the diameter of the core wire greatly changes between the large diameter portion and the small diameter portion. For this reason, the rigidity of the catheter tube to be manufactured does not change smoothly in the axial direction, and is easily bent locally, which can be a factor of reducing pushability and kink resistance.

  The present invention has been made to solve the above-described problems, and can improve the pushability and kink resistance by smoothly changing the rigidity of the manufactured catheter tube in the axial direction. It aims at providing the manufacturing method of the tube for catheters, the continuous body of the tube for catheters, and the core wire for catheter tube manufacture.

  A method of manufacturing a catheter tube that achieves the above object is a core wire including a large diameter portion and a small diameter portion having different outer diameters, and a transition portion formed by reducing the diameter from the large diameter portion to the small diameter portion. The resin is coated on the core wire formed so that the shape of the outer peripheral surface of the transition portion in the cross section along the axis of the core wire has a curve in which the slope continuously changes from the large diameter portion and the small diameter portion. And a covering body forming step for forming a covering body, and a core wire removing step for removing the core wire from the covering body.

  The manufacturing method of the catheter tube configured as described above is formed so that the inclination of the outer peripheral surface of the transition portion that covers the resin has a curve that continuously changes from the large diameter portion and the small diameter portion. The rigidity of the manufactured catheter tube can be changed smoothly and inclined in the axial direction, and the ease of local bending is suppressed to improve the pushability and kink resistance of the manufactured catheter tube. be able to.

  If the shape of the core wire in the cross section along the axis of the outer peripheral surface of the transition portion is formed only by a curve, the rigidity of the manufactured catheter tube can be changed more smoothly than the axial direction. It is possible to suppress the local bending ease, and to further improve the pushability and kink resistance of the manufactured catheter tube.

  In the core wire, the large-diameter portion and the small-diameter portion are continuously formed in advance at a predetermined interval, and the tubular wire is formed on the core wire after the covering body forming step and before the core wire removing step. By further cutting a continuous body together with the core wire at predetermined positions of the small diameter portion and the large diameter portion to cut out a plurality of single tubes, the catheter has different diameters on the distal end side and the proximal end side. The tube can be efficiently manufactured by forming a continuous continuous tubular body on the core wire.

  After the covering body forming step, if it further comprises an outer layer covering body forming step for forming an outer layer covering body by coating a resin radially outward from the covering body, a multilayer structure composed of a plurality of layers is formed. A catheter tube can be efficiently manufactured using a core wire.

  After the covering body forming step, if it further includes a reinforcing body forming step for forming a reinforcing body made of a wire material on the radially outer side than on the covering body, the manufactured catheter tube according to the site. It can reinforce and can improve indentation property and kink resistance.

  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, the large diameter portion and the small diameter portion having different outer diameters, and the large diameter portion A unit structure including a transition portion formed by reducing the diameter from the narrow diameter portion to the small diameter portion is a core wire continuously formed at a predetermined interval in advance, and in a cross section along the axis of the core wire of the outer peripheral surface of the transition portion For a catheter having a core wire having a shape whose curve continuously changes from the large-diameter portion and the small-diameter portion, and a covering formed by coating the core wire with a resin If the tube is a continuous body, the inclination of the outer peripheral surface of the transition portion to be coated with the resin is formed with a curve that continuously changes from the large diameter portion and the small diameter portion. The rigidity of the RakaKatsu inclined manner can be varied, by suppressing the local bending ease, it is possible to improve the pushability and kink resistance of the catheter tube to be manufactured.

  If the shape of the core wire in the continuum is formed by only a curved line in the cross section along the axis of the outer peripheral surface of the transition portion, the rigidity of the manufactured catheter tube is smoother than in the axial direction. It is possible to reduce the local bending ease and further improve the pushability and kink resistance of the manufactured catheter tube.

  If the continuous body further includes an outer layer covering body formed of a resin on a radially outer side than the covering body, a multi-layered catheter tube composed of a plurality of layers is continuously connected to the tubular continuous body. It can be efficiently manufactured using the body.

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

  A core wire for manufacturing a catheter tube, which is continuously formed by covering a single tube, which is an intermediate body of a catheter tube, from a large diameter portion and a small diameter portion having different outer diameters, and from the large diameter portion A unit structure including a transition portion formed by reducing the diameter to the small diameter portion is continuously formed in advance at a predetermined interval, and the shape of the outer peripheral surface of the transition portion in the cross section along the axis of the core wire is the thick portion. If the core wire is formed with a curved line whose slope continuously changes from the diameter part and the small diameter part, the rigidity of the catheter tube to be manufactured can be smoothly and inclinedly changed in the axial direction. The ease of local bending can be suppressed, and the pushability and kink resistance of the manufactured catheter tube can be improved.

  If the shape of the outer circumference of the catheter tube manufacturing core wire in the cross section along the axis of the core wire is formed only by a curve, the catheter tube manufacturing core wire has a rigidity in the axial direction. It can be changed more smoothly, the local bending ease can be suppressed, and the pushability and kink resistance of the manufactured catheter tube can be further improved.

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 top view which expanded a part of core wire. 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 flexible tubular member, a tube base end portion 11 located on the base end side, and an outer diameter and an inner diameter smaller than the tube base end portion 11. And a tube transition portion 13 whose outer diameter and inner diameter gradually change in the axial direction between the tube base end portion 11 and the tube tip 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. The outer layer 17 includes an outer layer proximal end portion 17A located at the tube proximal end portion 11, an outer layer transition portion 17B located at the tube transition portion 13, and an outer layer distal end portion 17C located at the tube distal end portion 12. The outer layer base end portion 17A, the outer layer transition portion 17B, and the outer layer front end portion 17C are all formed so that the thickness decreases in the direction from the base end side toward the front end side. The outer layer base end portion 17A, the outer layer transition portion 17B, and a part of the outer layer tip end portion 17C may be formed so that the thickness decreases in the direction from the base end side toward the tip end side. In the end portion 17A, it is preferable that the thickness decreases in the direction from the proximal end side toward the distal end side. The outer layer 17 may be formed with a certain thickness. The configuration and materials of the inner layer 15, the reinforcing layer 16, the outer layer 17, and the hydrophilic layer 18 will be described in detail in the manufacturing method described 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 a catheter tube according to this 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 (FIG. 3C) for forming the reinforcing body 52 on at least part of the inner layer covering body 51, and the reinforcing body 52 and the inner layer covering body 51 are integrated. Outer layer covering body forming step (FIG. 3 (D)) for covering the surface and forming the outer layer covering body 53, hydrophilic covering body forming step (FIG. 3 (E)) for covering the hydrophilic covering body 54, core wire A cutting step (FIG. 3 (F)) for cutting the tubular continuous body 60 obtained on 40 at a predetermined position of the core wire 40 to cut the single tube 61, and a core wire stretching step for stretching the core wire 40 (FIG. 3 (G)). ) And a core wire removal step for removing the core wire 40 from each single tube 61 (FIG. 3). It has a H)), 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 unit structures 45 having first transition portions 43 and second transition portions 44 whose outer diameters gradually change in the axial direction of the core wire 40 are continuously arranged at predetermined intervals. . 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 shown in FIG. 4, the first transition portion 43 is a large-diameter curved surface portion formed by a curve in which the outer peripheral surface in the cross section along the axis of the core wire 40 continuously changes in inclination from the large-diameter portion 41. 43A and a small-diameter side curved surface portion 43B formed by a curve whose inclination continuously changes from the small-diameter portion 42. The large-diameter-side curved surface portion 43A is formed as a curved surface that is convex outward in the radial direction, and the small-diameter-side curved surface portion 43B is formed as a curved surface that is concave inward in the radial direction. The large-diameter-side curved surface portion 43A and the small-diameter-side curved surface portion 43B are connected so that the inclination is continuous at the curved-surface boundary portion 43C, and accordingly, a cross section along the axis of the core wire 40 on the outer peripheral surface in the first transition portion 43. The shape at is formed only by curves. The inclination angle X with respect to the axis of the first transition portion 43 is equal to the large diameter portion 41 at the connecting portion with the large diameter portion 41, gradually increases toward the small diameter portion 42, and has the maximum inclination at the curved boundary portion 43C. It becomes a corner. Further, the inclination angle X with respect to the axis of the first transition portion 43 gradually decreases from the curved boundary portion 43 </ b> C toward the small diameter portion 42, and becomes equal to the small diameter portion 42 at the connecting portion with the small diameter portion 42. Although the 2nd transition part 44 is formed in the symmetrical shape with the 1st transition part 43, since the part coat | covered with the 2nd transition part 44 is removed, a shape is not limited. In addition, the large diameter part 41 and the small diameter part 42 may also be comprised by the curve from which an inclination changes continuously with the transition part 43 (not shown).

  As an example of the dimension of the core wire 40, 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 first transition portion 43 is 50 mm, and the outer diameter D1 of the large diameter portion 41. Is 0.55 to 0.6 mm, the outer diameter D2 of the small diameter portion 42 is 0.45 to 0.50 mm, the inclination angle X at the connection portion of the first transition portion 43 with the large diameter portion 41 is 0 degree, the first The maximum inclination angle X of the transition part 43 can be 10 to 60 degrees, and the inclination angle X at the connection part of the first transition part 43 with the small diameter part 42 can be 0 degree, but the dimensions are not limited thereto.

  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.

  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 part corresponding to the large diameter part 41 is 0.57 to 0.76 mm, and the outer diameter of the inner layer covering 51 in the part corresponding to the small diameter part 42 is 0.47 to 0.53 mm. However, 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 extruder 100 as shown in FIG. 5, a thermoplastic resin layer (here, inner layer covering 51) is formed 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. It is wound around a collection roll 107 and collected. 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. The method by dip molding will be outlined. First, in a container 200 as shown in FIG. 6, 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 accommodated. 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. For example, the film thickness of the part corresponding to the small diameter part 42 can be made thinner than the large diameter part 41, and the film thickness of the part corresponding to the transition part 43 can be gradually changed.

  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 arbitrarily changed. 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, by increasing the rotational speed at the time of pulling up the small diameter portion 42 rather than at the time of pulling up the large diameter portion 41, the film thickness covered by the small diameter portion 42 is changed to the film thickness covered by the large diameter portion 41. Can be made thinner. And when pulling up the transition part 43, the film thickness in the transition part 43 is changed smoothly and incline between the large diameter part 41 and the small diameter part 42 by changing the rotational speed of the core wire 40 gradually. be able to. 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).

  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, at least a part of the inner layer covering body 51 and the reinforcing body 52 is covered to form an outer layer covering body 53 (outer layer covering body forming step). In the reinforcing body forming step, the outer periphery of the inner layer covering 51 and the reinforcing body 52, ie, the outer circumference in the radial direction of the inner layer covering 51 is coated with the thermoplastic resin as a material while changing the thickness by extrusion molding. A body 53 is formed. The outer layer covering 53 is covered such that the thickness decreases in the direction from the large diameter portion 41 of the core wire 40 toward the first transition portion 43. As an example, the thickness A1 on one side of the portion corresponding to the large diameter portion 41 of the outer layer covering 53 is 0.08 to 0.1 mm, and the thickness A2 on the other side of the portion corresponding to the large diameter portion 41 is 0. 0.06 to 0.08 mm, the thickness A3 on one side of the portion corresponding to the small diameter portion 42 is 0.04 to 0.06 mm, and the thickness A4 on the other side of the portion corresponding to the small diameter portion 42 is 0.02 ˜0.04 mm, and A1> A2> A3> A4. As specific numerical examples when A1> A2> A3> A4, A1 = 0.1 mm, A2 = 0.08 mm, A3 = 0.04 mm, and A4 = 0.02 mm. As another example, A1> A2> A3> A4 can be set, and as specific numerical examples in this case, A1 = 0.1 mm, A2 = 0.08 mm, A3 = 0.02 mm, A4 = 0 .04 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, etc. A thermoplastic resin such as a polymer material 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 the outer layer covering 53 is extruded, the above-described extrusion molding machine 100 as shown in FIG. 5 is used and the core wire 40 is covered with the inner layer covering 51 and the reinforcing member 52 (FIG. 3C). The outer layer covering 53 can be extruded using the core material W as a reference). In extrusion molding, the thickness of the outer layer covering 53 to be formed can be reduced by increasing the take-up speed, and the thickness of the outer layer covering 53 to be formed can be increased by reducing the take-off speed. By extruding while changing the take-up speed, the outer layer covering 53 having a different thickness in the axial direction of the core wire 40 can be formed.

  Further, in the outer layer covering body forming step, the outer layer covering body 53 is not formed by extrusion molding, but the container 200 as shown in FIG. 6 is used and the core wire 40 is covered with the inner layer covering body 51 and the reinforcing body 52. The outer layer covering 53 can be dip-molded using the core material W (see FIG. 3C).

  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.

  When the outer layer covering 53 is formed by a method other than extrusion molding, the material of the outer layer covering 53 is not limited to a thermoplastic resin, and for example, a thermosetting resin such as an epoxy resin can also be applied.

  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 distal end portion of the catheter tube 10, a part of the reinforcing body 52 corresponding to the small diameter portion 42 can be removed.

  After the outer layer covering body forming step, as shown in FIG. 3E, the hydrophilic polymer substance (hydrophilic material) is coated on the front end side of the outer layer covering body 53 to form the hydrophilic covering body 54. (Hydrophilic covering forming step). The hydrophilic covering 54 finally constitutes the hydrophilic layer 18 (see FIG. 2) on the outer surface of the catheter tube 10. The hydrophilic layer 18 exhibits lubricity when contacted with a liquid such as blood or physiological saline, reduces the frictional resistance of the catheter tube 10, and further improves the slidability. 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. For this reason, the range in which the hydrophilic layer 18 in the longitudinal direction of the catheter tube 10 is provided excludes 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 that it is a region. Therefore, the hydrophilic covering 54 covered on the outer peripheral surface of the outer covering 53 is covered on a part of the outer covering 53 so that the hydrophilic layer 18 is provided in the above range. Specifically, a plurality of coating ranges B corresponding to a part of the large-diameter portion 41 and the small-diameter portion 42 are provided at predetermined intervals along the axial direction of the core wire 40, and these coating ranges B are hydrophilicly coated. Form body 54. Thereby, a tubular continuous body 60 including the inner layer covering body 51, the reinforcing body 52, the outer layer covering body 53, and the hydrophilic covering body 54 is formed on the core wire 40. The configuration including the core wire 40 in the tubular continuous body 60 is referred to as a catheter tube continuous body 65.

  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.

  In the hydrophilic covering forming step, the hydrophilic covering 54 can be formed by dip molding using the core W as a structure in which the inner layer covering 51, the reinforcing body 52, and the outer covering 53 are coated on the core wire 40. . In dip molding, the apparatus 300 shown in FIG. 7 can be used. The apparatus 300 collects the container 301 containing a solution R2 in which a hydrophilic polymer material is dissolved in a solvent, the supply roll 302 for supplying the core W, and the core W coated with the hydrophilic covering 54. And a collection roll 303. The core material W extends downward from the supply roll 302, curves in a U shape at the lower end, extends upward, and reaches the recovery roll 303. Examples of the solvent that can be used include dimethylformamide, dimethyl sulfoxide, and tetrahydrofuran.

  When the core material W is coated with the hydrophilic coating 54, when the core material W is not immersed in the solution R 2 and the recovery roll 303 is stopped and the core material W is supplied from the supply roll 302, the coating range B After positioning the core material W at a position where only the core R is immersed in the solution R2, the supply by the supply roll 302 and the recovery by the recovery roll 303 are stopped and the core material W is fixed (see the one-dot chain line in FIG. 7). Next, the coating area B is immersed in the solution R2 by supplying the core material W from the supply roll 302 in a state where the collection roll 303 is stopped. After a predetermined time has passed, the supply roll 302 is stopped, the core material W is wound up by the collection roll 303, and the core material W is pulled up from the solution R2. The solution R2 attached to the core material W is naturally dried or dried by heating with hot air, a heater, or the like, and the hydrophilic covering 54 is covered only in the covering range B. Thereafter, in order to coat the hydrophilic coating 54 in the next coating range B provided at a predetermined interval, the supply roll 302 and the recovery roll 303 are operated so that only the coating range B can be immersed in the solution R2. After the core material W is moved to position the core material W, the supply by the supply roll 302 and the recovery by the recovery roll 303 are stopped to fix the core material W. Thereafter, by repeating the above steps, the core material W can be coated with the hydrophilic covering 54 at a predetermined interval. As long as the hydrophilic covering 54 can be formed, the forming method is not limited. For example, the hydrophilic covering 54 may be coated by a known method such as spraying, spraying, coating, printing, or the like.

  The hydrophilic covering forming step may be performed after 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.

  After the hydrophilic covering forming process, as shown in FIG. 3F, the tubular continuous body 60 is cut together with the core wire 40 at a predetermined position (cutting process). 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 single tube 61 corresponds to one catheter tube 10 and is an intermediate body before reaching the catheter tube 10. The surplus tube 62 is removed as an unnecessary portion. As described above, since the hydrophilic covering 54 is formed before the cutting step, it is not necessary to re-position the single tube 61 cut out to form the hydrophilic covering 54 after cutting, so that the work can be performed. The number of times of positioning can be reduced, and the catheter tube 10 can be manufactured efficiently. As an example, the length of the part corresponding to the large diameter part 41 of the core wire 40 is 1600 mm, and the length of the part corresponding to the small diameter part 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, the cutting is performed with a cutting blade by a shearing machine or the like, but any cutting method may be used as long as the core wire 40 and the tubular continuous body 60 can be cut.

  After the cutting step, as shown in FIG. 3 (G), 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 before stretching. And the entire core wire 40 is stretched (core wire stretching step). Thereafter, as shown in FIG. 3H, the core wire 40 is pulled out from the large diameter portion 41 side (core wire removing step). Thereby, manufacture of the tube 10 for catheters is completed. 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.

  As described above, in the method for manufacturing the catheter tube 10 according to this embodiment, the shape of the first transition portion 43 (transition portion) in the cross section along the axis of the core wire 40 on the outer peripheral surface is the large diameter portion 41 and the small diameter portion. Inner layer covering body forming step (covering body forming step) in which an inner layer covering body 51 (covering body) is formed by coating a resin on the core wire 40 having a curve whose inclination continuously changes from the portion 42. And a core wire removal step of removing the core wire 40 from the inner layer covering 51. Thus, since the inclination of the outer peripheral surface of the first transition portion 43 covering the resin is formed with a curve that continuously changes from the large diameter portion 41 and the small diameter portion 42, the manufactured catheter The rigidity of the tube 10 can be changed smoothly and in the axial direction, the local bending ease can be suppressed, and the pushability and kink resistance of the manufactured catheter tube 10 can be improved. .

  Moreover, since the inner layer covering body 51, the reinforcing body 52, the outer layer covering body 53, and the hydrophilic covering body 54 corresponding to the plurality of catheter tubes 10 are formed as the tubular continuous body 60 at a time, the productivity is excellent.

  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.

  Moreover, since the shape in the cross section in alignment with the axis line of the said core wire 40 of the outer peripheral surface in the 1st transition part 43 is formed only by the curve, the core wire 40 makes the rigidity of the manufactured catheter tube 10 smoother to an axial direction. Therefore, the pushability and kink resistance of the manufactured catheter tube 10 can be further improved.

  The core wire 40 has a large-diameter portion 41 and a small-diameter portion 42 that are continuously formed at a predetermined interval in advance, and after the inner layer covering body forming step (covering body forming step) and before the core wire removing step. In addition, a cutting step is performed in which the tubular continuous body 60 formed on the core wire 40 is cut together with the core wire 40 at predetermined positions of the small-diameter portion 42 and the large-diameter portion 41 to cut out a plurality of single tubes 61. And the catheter tube 10 having different diameters on the proximal end side can be efficiently manufactured using the continuous tubular body 60 that is continuously connected.

  In addition, since the outer layer covering body forming step is performed after the inner layer covering body forming step, in which the outer layer covering body 53 is formed by coating the resin radially outside the inner layer covering body 51, a multilayer structure composed of a plurality of layers The catheter tube 10 can be efficiently manufactured using the continuous tubular body 60 that is continuously connected.

  Moreover, since the reinforcement body formation process which forms the reinforcement body 52 which consists of a wire material in the radial direction outer side rather than the inner layer coating body 51 is performed after an inner layer coating body formation process, the manufactured tube 10 for catheters according to site | parts. Can be reinforced, and indentability and kink resistance can be improved.

  Moreover, the continuous body 65 of the catheter tube includes a large diameter portion 41 and a small diameter portion 42 having different outer diameters, and a first transition portion 43 formed by reducing the diameter from the large diameter portion 41 to the small diameter portion 42. The unit structure 45 is continuously formed at a predetermined interval in advance, and the shape of the cross section along the axis of the core wire 40 on the outer peripheral surface of the first transition portion 43 is continuously inclined from the large diameter portion 41 and the small diameter portion 42. It has the core wire 40 formed with the curve which changes, and the inner layer coating | coated body 51 (coating body) formed by coat | covering resin on the core wire 40. FIG. Thus, since the inclination of the outer peripheral surface of the first transition portion 43 covering the resin is formed with a curve that continuously changes from the large diameter portion 41 and the small diameter portion 42, the manufactured catheter The rigidity of the tube 10 can be changed smoothly and in the axial direction, the local bending ease can be suppressed, and the pushability and kink resistance of the manufactured catheter tube 10 can be improved. .

  Further, a core tube 40 for manufacturing a catheter tube, which 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, and A unit structure 45 including a first transition portion 43 formed by reducing the diameter from the large diameter portion 41 to the small diameter portion 42 is continuously formed in advance at a predetermined interval, and the core wire 40 on the outer peripheral surface of the first transition portion 43. The shape of the cross section along the axis of the catheter tube is formed to have a curve whose inclination continuously changes from the large diameter portion 41 and the small diameter portion 42, so that the catheter tube is manufactured by covering the core wire 40. The rigidity of the tube 10 can be changed smoothly and inclined in the axial direction, the local bending ease is suppressed, and the pushability and kink resistance of the manufactured catheter tube 10 can be improved. Can.

  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, like a core wire 80 as a modified example shown in FIG. 8, the second transition portion 84 between the large diameter portion 81 and the small diameter portion 82 is formed at an inclination angle of 90 degrees with respect to the axis line of the core wire 80. Also good. Thereby, the length of the surplus tube removed after cutting is shortened (refer to the surplus tube 62 in FIG. 3F), so that the cost can be reduced and the manufacturing area can be saved.

  Further, like a core wire 90 as another modified example shown in FIG. 9, the first transition portion 93 has a large-diameter side curved surface portion 93A formed by a curve whose inclination continuously changes from the large-diameter portion 91, and An intermediate portion 95 in which the shape of the outer peripheral surface in a cross section along the axis of the core wire 90 is linear is provided between the small diameter portion 92 and the small diameter side curved surface portion 93B formed by a curve whose inclination continuously changes. May be.

  Moreover, in this embodiment, although the large diameter part 41 and the small diameter part 42 are continuously formed in the core wire 40 by the predetermined space | interval, it does not need to be formed continuously and one core wire is one. Only the catheter tube 10 may be manufactured.

  Further, a radiopaque marker may be arranged between the inner layer covering body 51 and the reinforcing body 52, or between the outer layer covering body 53 and the reinforcing body 52, or on the outer layer covering body 53. In addition, each of the reinforcing body 52, the outer layer covering body 53, and the hydrophilic covering body 54 may not be formed.

  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, 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 core wire may be formed with a constant outer diameter without providing the small diameter portion and the large diameter portion. When the core wire has a constant outer diameter, the core wire removal step can be performed before the cutting step.

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 First transition part (transition part),
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,
B Covering range.

Claims (11)

A core wire having a large diameter portion and a small diameter portion having different outer diameters, and a transition portion formed by reducing the diameter from the large diameter portion to the small diameter portion, and the axis of the core wire on the outer peripheral surface of the transition portion A covering body forming step of forming a covering body by coating a resin on a core wire formed so that the shape in the cross section along the curved line whose inclination continuously changes from the large diameter portion and the small diameter portion;
And a core wire removing step of removing the core wire from the covering.   The said core wire is a manufacturing method of the catheter tube of Claim 1 in which the shape in the cross section in alignment with the axis line of the said core wire of the outer peripheral surface in the said transition part is formed. 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 core wire removing step, a tubular continuous body obtained on the core wire is cut together with the core wire at predetermined positions of the small diameter portion and the large diameter portion, and a plurality of single bodies The manufacturing method of the tube for catheters of Claim 1 or 2 which further has the cutting process which cuts out a tube.   The outer layer covering body formation process which coat | covers resin outside radial direction rather than the said covering body and forms an outer layer covering body after the said covering body formation process of any one of Claims 1-3. A method for producing a catheter tube.   The catheter tube according to any one of claims 1 to 4, further comprising a reinforcing body forming step of forming a reinforcing body made of a wire material on a radially outer side of the covering body after the covering body forming step. Production method. 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 unit structure including a large diameter portion and a small diameter portion having different outer diameters, and a transition portion formed by reducing the diameter from the large diameter portion to the small diameter portion is continuously formed in advance at a predetermined interval. There is a core wire formed in a shape in which a cross-section along the axis of the core wire of the outer peripheral surface of the transition portion has a curve whose inclination continuously changes from the large diameter portion and the small diameter portion,
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 6 in which the shape in the cross section in alignment with the axis line of the said core wire of the outer peripheral surface in the said transition part is formed only by a curve.   The continuous body of the catheter tube according to claim 6 or 7, further comprising an outer layer covering body formed of a resin on a radially outer side than the covering body.   The continuous body of the tube for catheters of any one of Claims 6-8 which further has the reinforcement body which consists of a wire in 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 unit structure comprising a large-diameter portion and a small-diameter portion having different outer diameters, and a transition portion formed by reducing the diameter from the large-diameter portion to the small-diameter portion is continuously formed in advance at a predetermined interval, and the transition The core wire formed in the shape in the cross section in alignment with the axis line of the said core wire of the outer peripheral surface in a part has a curve from which the inclination changes continuously from the said large diameter part and a small diameter part.   The core wire for manufacturing a catheter tube according to claim 10, wherein the shape of the outer peripheral surface of the transition portion in a cross section along the axis of the core wire is formed only by a curve.

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