JP2014100323A - Catheter tube manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter tube manufacturing method capable of more freely shaping a plurality of catheter tubes while continuously manufacturing the catheter tubes using the same core wire.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 resign onto a core wire 40; an external coat layer body forming step, following the internal coat layer body forming step, of forming an external coat layer body 53 by applying a coat of a thermoplastic resin radially outward of the internal coat layer body 51 by an extrusion molding process while changing the thickness of the coat in an axial direction of the core wire; a cutting step, following the external coat layer body forming step, of cutting at predetermined positions a tubular continuous body 60 obtained by forming the internal coat layer body 51 and the external coat layer body 53 on the core wire 40, into a plurality of discrete tubes 61; and a core wire removing step of removing the core wire 40 from the discrete tubes 61.

Description

  The present invention relates to a method for manufacturing a catheter tube used for a catheter used in a lumen such as a blood vessel or a body cavity.

  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, catheters that are selectively introduced into complex branched blood vessels in the body are typically selectively pushed along a guide wire that is pre-introduced into the blood vessel to provide therapeutic drugs and diagnostics. The contrast agent for use 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 inner and outer diameters on the proximal side, so that the injection characteristics of drugs and contrast agents are enhanced while maintaining sufficient rigidity and pushability. 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 producing such a catheter tube, for example, Patent Document 1 discloses that an inner layer is formed by coating a thermoplastic resin on a core wire in which a large diameter portion and a small diameter portion having different outer diameters are continuously provided at a predetermined interval. A covering body is formed, a reinforcing body such as a metal wire or a resin fiber is formed on the inner layer covering body, and an outer layer covering body made of a thermoplastic resin is coated on the reinforcing body by extrusion molding. A method is described in which after a tube is formed as a continuous body on the same core wire, the continuous body is cut together with the core wire for each catheter tube, and the core wire is pulled out and removed to produce a catheter tube.

JP 2008-183226 A

  However, in the method described in Patent Document 1 described above, changes in the outer diameter and inner diameter on the distal end side and the proximal end side of the catheter tube are set by providing a large diameter portion and a small diameter portion on the core wire, The shape applicable to the catheter tube is limited.

  The present invention has been made in order to solve the above-described problems, and while continuously manufacturing a plurality of catheter tubes using the same core wire, the shape of the manufactured catheter tube can be set more freely. An object of the present invention is to provide a method for manufacturing a catheter tube.

  A method for manufacturing a catheter tube that achieves the above object includes an inner layer covering forming step of forming an inner layer covering by coating a resin on a core wire, and extruding a thermoplastic resin after the inner layer covering forming step. The outer layer covering body forming step of forming an outer layer covering body by coating the outer side of the inner layer covering body in the radial direction while changing the thickness in the axial direction of the core wire, and the core after the outer layer covering body forming step A cutting step of cutting a tubular continuous body obtained by providing the inner layer covering body and the outer layer covering body on a line at a predetermined position to cut out a plurality of single tubes; and a core wire removing step of removing the core wires from the single tubes; , A method for producing a catheter tube.

  The method for manufacturing a catheter tube configured as described above covers the outer layer covering body while changing the thickness in the axial direction of the core wire by extrusion molding on the outer side in the radial direction from the inner layer covering body. The shape of the catheter tube can be set more freely.

  The core wire is formed by continuously forming catheter tubes having different diameters at the distal end side and the proximal end side by continuously forming a large diameter portion and a small diameter portion having different outer diameters at predetermined intervals. It can manufacture efficiently using a continuous tubular continuous body.

  In the cutting step, the tubular continuous body is cut at predetermined positions of the large diameter portion and the small diameter portion to cut out the plurality of single tubes, and the core wire removing step is performed after the cutting step. Then, even if it is difficult to remove the core wire before cutting because the large diameter portion and the small diameter portion are formed on the core wire, the core wire can be easily removed after the cutting step.

  In the outer layer covering body forming step, if the outer layer covering body is formed so that the thickness decreases in the direction from the large diameter portion toward the small diameter portion, the proximal end side of the manufactured catheter tube and The thickness of the outer covering can be reduced from the proximal end portion to the distal end portion inserted into the living body, and the rigidity of the catheter tube changes smoothly and in an inclined manner along the axis, and is locally Therefore, it is possible to manufacture a catheter tube excellent in indentability and kink resistance.

  If the core wire 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 rigidity of the catheter tube to be manufactured is along the axis. Therefore, it is possible to manufacture a catheter tube having excellent pushability and kink resistance.

  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 rigidity of the manufactured catheter tube changes smoothly and inclined along the axis. In addition, it is possible to manufacture a catheter tube that is suppressed in local bending and excellent in pushability and kink resistance.

  If the catheter further includes a reinforcing body forming step for forming a reinforcing body made of a wire on the radially outer side of the inner layer covering body after the inner layer covering body forming step, the manufactured catheter tube can be made according to the site. Can be reinforced, and indentability and kink resistance can be 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 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 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 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, an inner layer cover formation step for forming an inner layer cover 51 on the core wire 40 (FIG. 3B), and The reinforcing body forming step (FIG. 3C) for forming the reinforcing body 52 on the inner layer covering body 51, and the outer layer covering forming the outer layer covering body 53 by integrally covering the reinforcing body 52 and the inner layer covering body 51 A body forming step (FIG. 3D), a hydrophilic covering forming step for covering the hydrophilic covering 54 (FIG. 3E), and a tubular continuous body 60 obtained on the core wire 40. A cutting step (FIG. 3 (F)) for cutting the single tube 61 by cutting at the position, a core wire drawing step (FIG. 3 (G)) for drawing the core wire 40, and a core wire for removing the core wire 40 from each single tube 61 And a removal step (FIG. 3H). 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.

  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. 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. 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. . In addition, the reinforcement body 52 does not need to be provided.

  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. The body 53 is molded. The outer layer covering 53 is coated such that the thickness decreases in the direction from the large diameter portion 41 of the core wire 40 toward the one small diameter portion 42. 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 extruding the outer layer covering 53, the above-described extruder 100 as shown in FIG. 4 is used to coat the core wire 40 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 whose thickness changes in the axial direction of the core wire 40 can be formed.

  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 formation step, as shown in FIG. 3E, the outer layer covering 53 is coated with a hydrophilic polymer substance (hydrophilic material) to form a hydrophilic covering 54 (hydrophilicity). Cover body 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.

  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 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, 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, the manufacturing method of the catheter tube 10 according to the present embodiment includes the inner layer covering body forming step in which the core wire 40 is coated with the resin to form the inner layer covering body 51, and the inner layer covering body forming step. An outer layer covering body forming step in which an outer layer covering body 53 is formed by coating a thermoplastic resin in the radial direction outside the inner layer covering body 51 while changing the thickness in the axial direction of the core wire 40 by extrusion molding; A cutting step of cutting a plurality of single tubes 61 by cutting a tubular continuous body 60 obtained by including the inner layer covering 51 and the outer layer covering 53 on the core wire 40 after the forming step, and cutting the plurality of single tubes 61; A core wire removing step for removing the core wire 40 from the core wire. In this way, the outer layer covering 53 is coated on the outer side in the radial direction of the inner layer covering 51 while changing the thickness by extrusion, so that the shape of the catheter tube 10 composed of a plurality of layers can be set more freely. Become.

  Moreover, as a method of forming the outer layer covering 53, for example, a cylindrical body is covered on the outer side of the inner covering 51, and a heat shrinkable tube is further covered on the outer side of the cylindrical body, and the cylindrical body and the heat shrinkable tube are heated. There is a method in which the cylinder is formed as the outer layer covering 53 on the outer periphery of the inner layer covering 51 by the contraction force of the heat shrinkable tube while the tube is softened or melted. A tube is required and the manufacturing cost is high. On the other hand, the manufacturing method according to the present embodiment does not require an expensive heat-shrinkable tube, so that the manufacturing cost can be reduced.

  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 of manufacturing a catheter tube, a hot stretching process is generally performed in which a tube is subjected to a hot stretching process, and the inner and outer diameters are reduced from the proximal end side to the distal end 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.

  In addition, since the core wire 40 is formed with the large-diameter portion 41 and the small-diameter portion 42 having different outer diameters continuously at a predetermined interval, the catheter tube 10 having different diameters on the distal end side and the proximal end side is continuously connected. The tubular continuous body 60 that is continuously connected can be efficiently manufactured while being formed on the core wire 40. 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.

  Further, in the cutting step, the tubular continuous body 60 is cut at predetermined positions of the large diameter portion 41 and the small diameter portion 42 to cut out the plurality of single tubes 61, and the core wire removing step is performed after the cutting step. By forming the large diameter portion 41 and the small diameter portion 42 on the core wire 40, the core wire 40 can be easily removed after the cutting process even if it is difficult to remove the core wire 40 before cutting.

  Further, in the outer layer covering body forming step, the outer layer covering body 53 is formed so that the thickness decreases in the direction from the large diameter portion 41 to the small diameter portion 42. The thickness of the outer layer 17 can be reduced from the tube proximal end portion 11 to the tube distal end portion 12 inserted into the living body, and the rigidity of the catheter tube 10 changes smoothly and in an inclined manner along the axis. In addition, local bending is suppressed, and the catheter tube 10 having excellent pushability and kink resistance can be manufactured.

  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, the rigidity of the catheter tube 10 manufactured is manufactured. However, between the large-diameter portion 41 and the small-diameter portion 42 whose diameter changes greatly, it changes smoothly and in an inclined manner along the axis of the catheter tube 10, local bending is suppressed, and pushability and resistance are improved. The catheter tube 10 having excellent kink properties can be manufactured.

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

  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, 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. In FIG. 7, 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, 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.

  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. Further, each of the reinforcing body 52 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, 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 Transition section,
51 inner layer covering,
52 reinforcements,
53 outer layer covering,
54 hydrophilic covering,
60 tubular continuum,
61 Single tube,
63 1st cutting part,
64 second cutting part,
A1 Thickness of the outer layer covering on one end side of the large diameter portion,
A2 The thickness of the outer layer covering on the other end side of the large-diameter portion,
A3, the thickness of the outer layer covering at one end of the small diameter portion,
A4, the thickness of the outer layer covering on the other end side of the small diameter portion,
D1 Outer diameter of the large diameter part,
D2 Outer diameter of small diameter part,
X Tilt angle.

Claims (7)

An inner layer covering forming step of forming an inner layer covering by coating a resin on the core wire;
After the inner layer covering body forming step, an outer layer covering is formed by covering the outer side of the inner layer covering body in the radial direction while changing the thickness in the axial direction of the core wire by extrusion molding the thermoplastic resin. Body formation process,
A cutting step of cutting a plurality of single tubes by cutting a tubular continuous body obtained by providing the inner layer covering and the outer layer covering on the core wire after the outer layer covering forming step;
And a core wire removing step of removing the core wire from the single tube.   The method for producing a catheter tube according to claim 1, wherein the core wire is formed such that a large diameter portion and a small diameter portion having different outer diameters are continuously formed at a predetermined interval. In the cutting step, the tubular continuous body is cut at a predetermined position of the large diameter portion and the small diameter portion to cut out a plurality of single tubes,
The method for manufacturing a catheter tube according to claim 2, wherein the core wire removing step is performed after the cutting step.   The method for manufacturing a catheter tube according to claim 2 or 3, wherein, in the outer layer covering body forming step, the outer layer covering body is formed so that the thickness decreases in a direction from the large diameter portion toward the small diameter portion.   The catheter core according to any one of claims 2 to 4, wherein the core wire 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. Production method.   The method for manufacturing a catheter tube according to claim 5, 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 catheter use according to any one of claims 1 to 6, further comprising a reinforcing body forming step of forming a reinforcing body made of a wire on a radially outer side of the inner layer covering body after the inner layer covering body forming step. Tube manufacturing method.

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