JP7432360B2 - Balloon catheter manufacturing method and mold - Google Patents

Description

The present invention relates to a method for manufacturing a balloon catheter having a balloon provided with a protrusion, and a mold used for manufacturing a balloon catheter having a balloon provided with a protrusion.

It is known that various diseases occur due to stenosis of blood vessels, which are the channels through which blood circulates within the body, resulting in stagnation of blood circulation. In particular, when stenosis occurs in the coronary arteries that supply blood to the heart, there is a risk of serious diseases such as angina pectoris and myocardial infarction. As a method for treating such a narrowed portion of a blood vessel, there are techniques such as angioplasty such as PTA and PTCA that dilate the narrowed portion using a balloon catheter. Angioplasty is a minimally invasive therapy that does not require open heart surgery like bypass surgery, and is widely practiced.

A hardened narrowed portion may be formed on the inner wall of a blood vessel due to calcification or the like. In such calcified lesions, it is difficult to dilate the hardened stenosis using a general balloon catheter. Another method used is to dilate the narrowed area by placing an indwelling dilation device called a stent in the narrowed area of the blood vessel, but after this treatment, the neointima of the blood vessel grows excessively and the blood vessel becomes dilated again. ISR (In-Stent-Restenosis) lesions may occur in which stenosis occurs. In ISR lesions, the neointima is soft and the surface is slippery, so when using a general balloon catheter, the position of the balloon may shift from the lesion area when the balloon is expanded, which may damage the blood vessel.

As balloon catheters that can dilate stenotic areas even in calcified lesions and ISR lesions, there are balloon catheters in which the balloon has a scoring element (for example, Patent Documents 1 to 6).

Special table 2014-506140 publication Japanese Patent Application Publication No. 2015-104671 Japanese Patent Application Publication No. 2015-163219 JP2016-221313A Special Publication No. 2007-518448 Special Publication No. 2005-518842

Normally, in order to manufacture a balloon equipped with a scoring element as disclosed in Patent Documents 1 to 6, a parison having a protrusion is used, and a mold having a groove into which the protrusion is inserted is prepared. Then, the parison is placed inside this mold and blow molding is performed. When attempting to manufacture a balloon by so-called one-stage molding, in which the parison is expanded in one blow molding process using a mold with a lumen of the same shape as the balloon, the outside diameter of the parison before expansion is It is necessary to use a mold with a fairly large internal diameter, and the large difference in size between the outside diameter of the parison and the inside diameter of the mold causes the position of the protrusion to change as the parison expands. Because of the change in the radial direction and circumferential direction, the phase between the protrusion and the mold groove tends to shift. Therefore, when the parison is expanded, the protruding part of the balloon may be crushed or deformed due to being pressed against a part of the inner surface of the mold other than the groove, or the protruding part may be pressed against a part of the mold other than the groove. Expansion of the parison causes defects in balloon molding, such as thinning of the balloon near the protrusion, resulting in a decrease in yield. Therefore, it was necessary to expand the parison in multiple stages and mold the balloon using a plurality of molds each having a lumen shape in which the outer diameter of the balloon gradually increases. However, the balloon molding time is longer because it is necessary to prepare multiple molds with different lumen shapes, and the number of molding steps increases due to the stepwise expansion of the parison using multiple molds. In addition, there was a problem that the molding cost increased.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a method for manufacturing a balloon catheter that is unlikely to cause a phase shift of the protruding portion of the parison before and after expansion of the parison, and that allows one-step molding. Another object of the present invention is to provide a mold for use in manufacturing balloon catheters.

A method for manufacturing a balloon catheter that can solve the above problem includes: a shaft extending in the far-to-near direction; and a balloon provided on the distal side of the shaft and having a protrusion on the outer surface. A method for manufacturing a balloon catheter comprising the steps of: preparing a cylindrical parison having a protrusion on its outer surface; a mold body into which the parison is inserted; a step of preparing a mold having a movable part that is movable in a direction; a step of arranging a protrusion part in the inner part of the movable part; and a step of pressurizing the inside of the parison to expand the parison. It is characterized by containing.

In the method for manufacturing a balloon catheter of the present invention, it is preferable that the movable part be located outward from a straight line passing through the root of the protrusion in a cross section perpendicular to the distance direction of the parison at the end of expansion of the parison.

The method for manufacturing a balloon catheter of the present invention preferably includes a step of maintaining the position of the movable part after the step of pressurizing the inside of the parison and expanding the parison.

In the method for manufacturing a balloon catheter of the present invention, after the step of arranging the protrusion in the inner part of the movable part, the protrusion comes into contact with the inner part of the movable part, so that It is preferable that the movable member has a proximal end region that closes the movable portion, and a distal end region that is radially outward of the parison from the proximal end region and is separated from the inner portion of the movable portion.

In the method for manufacturing a balloon catheter of the present invention, after the step of arranging the protrusion in the inner part of the movable part, the movable part has a step of pressing the protrusion towards the inside of the mold. is preferred.

The method for manufacturing a balloon catheter of the present invention preferably includes a step of heating the movable part in the step of pressurizing the inside of the parison and expanding the parison.

The method for manufacturing a balloon catheter of the present invention preferably includes a step of cooling the movable part after the step of pressurizing the inside of the parison and expanding the parison.

The method for manufacturing a balloon catheter of the present invention preferably includes a step of coating the protrusion after the step of arranging the protrusion inside the movable part.

The mold that has been able to solve the above problem is a hollow mold into which a cylindrical parison having a protrusion on the outer surface is inserted, and includes a mold body and the inserted parison. and a movable part that is movable in the radial direction.

In the mold of the present invention, the movable part has a protruding part disposed inside the movable part, and when the movable part is disposed at the outermost position in the movable range of the movable part, the movable part is disposed in the distance direction of the parison. It is preferable that the protrusion be located outward from a straight line passing through the base of the protrusion in a cross section perpendicular to .

The mold of the present invention preferably has a holding mechanism that holds the position of the movable part.

The mold of the present invention preferably includes a pressing mechanism that presses the movable portion inward of the mold body.

In the mold of the present invention, it is preferable that a movable mechanism is disposed outside the movable portion in the radial direction of the mold body, and that a spring is disposed in the movable mechanism.

In the mold of the present invention, the movable mechanism is disposed outside the movable part in the radial direction of the mold body, and the movable mechanism preferably contains fluid.

In the mold of the present invention, the movable part has a groove, and the depth of the groove is preferably smaller than the height of the protrusion.

In the mold of the present invention, the average surface roughness Rz of the inner part of the movable part is preferably larger than the average surface roughness Rz of the inner surface of the mold body.

In the mold of the present invention, the average surface roughness Rz of the inner part of the movable part is preferably smaller than the average surface roughness Rz of the inner surface of the mold body.

In the mold of the present invention, it is preferable that the movable part has a groove, and the groove has portions with different groove depths in the axial direction of the mold body.

In the mold of the present invention, the movable portion preferably has a groove, and the groove preferably has an interrupted portion in the axial direction of the mold body.

In the mold of the present invention, it is preferable that a plurality of movable parts exist in the axial direction of the mold body.

In the mold body of the present invention, in the axial direction of the mold body, the mold body has a straight pipe part and tapered parts on both sides of the straight pipe part, and the movable part is arranged in the straight pipe part. It is preferable that the movable part is not disposed in the tapered part.

According to the method and mold for manufacturing a balloon catheter of the present invention, a mold having a movable part that is movable in the radial direction of the parison is used, and the protruding part of the parison is placed in the inner part of the movable part. Phase shift of the protruding portion of the parison before and after expansion of the parison is unlikely to occur, and the balloon can be molded in one step, making it possible to improve the manufacturing efficiency of the balloon catheter.

FIG. 4 is a cross-sectional view perpendicular to the perspective direction of the mold in the step of arranging the protrusion in the inner part of the movable part in the embodiment of the present invention. FIG. 3 is a cross-sectional view perpendicular to the perspective direction of the mold at the end of expansion of the parison in the embodiment of the present invention. FIG. 7 is a sectional view perpendicular to the perspective direction of the mold after the step of arranging the protrusion in the inner part of the movable part in another embodiment of the present invention.

Hereinafter, the present invention will be explained in more detail based on the following embodiments. However, the present invention is not limited by the following embodiments, and modifications may be made as appropriate within the scope that fits the spirit of the above and below. Of course, additional implementations are also possible, and all of these are included within the technical scope of the present invention. In addition, in each drawing, hatching, member codes, etc. may be omitted for convenience, but in such cases, the specification and other drawings shall be referred to. Further, the dimensions of various members in the drawings are given priority to help understanding the features of the present invention, and therefore may differ from actual dimensions.

FIG. 1 shows a sectional view perpendicular to the perspective direction of the mold in the process of arranging the protrusion inside the movable part in the embodiment of the present invention, and FIG. 2 shows the mold at the end of expansion of the parison. represents a cross-sectional view perpendicular to the perspective direction. The method for manufacturing a balloon catheter of the present invention includes a balloon catheter having a shaft extending in the far-to-near direction and a balloon 100 provided on the distal side of the shaft and having a protrusion 50 on the outer surface. The manufacturing method includes the steps of preparing a cylindrical parison 10 having a protruding portion 50 on the outer surface, a mold body 2 into which the parison 10 is inserted, and a mold body 2 provided in the mold body 2, and a parison 10 provided in the mold body 2. A process of preparing a mold 1 having a movable part 3 that is movable in the radial direction, a process of arranging a protrusion part 50 in the inner part of the movable part 3, and pressurizing the inside of the parison 10, 10.

In the present invention, the distal side refers to the direction toward the treatment target with respect to the extending direction of the balloon 100, and the proximal side refers to the opposite side of the distal side, that is, the direction in which the balloon 100 extends. In other words, it points toward the user's hand. Further, the direction from the proximal side to the distal side of the balloon 100 is referred to as the far-near direction.

The balloon catheter is configured such that fluid is supplied to the inside of the balloon 100 through a shaft, and the expansion and contraction of the balloon 100 can be controlled using an indeflator (balloon pressurizer). The fluid may be a pressurized fluid pressurized by a pump or the like.

The shaft extends in the distance direction and has a fluid flow path provided therein. Moreover, it is preferable that the shaft has an insertion passage for a guide wire inside. In order for the shaft to have a fluid flow path and a guidewire insertion path therein, for example, the shaft has an outer tube and an inner tube, the inner tube functions as a guidewire insertion path, It is mentioned that the space between the inner tube and the outer tube functions as a fluid flow path. If the shaft has an outer tube and an inner tube, the inner tube extends from the distal end of the outer tube and extends distally through the balloon 100, the distal side of the balloon 100 is joined to the inner tube, and the balloon Preferably, the proximal side of 100 is joined to the outer tube.

The present invention relates to a so-called over-the-wire type balloon catheter in which a wire is inserted from the distal side to the proximal side of the shaft, and a so-called rapid exchange type balloon catheter in which the wire is inserted halfway from the distal side to the proximal side of the shaft. Can be applied to any of the following balloon catheters. Although not shown, if the balloon catheter is over-the-wire, it may have a hub proximal to the shaft for directing fluid into the shaft. Preferably, the hub has a fluid inlet communicating with a flow path for fluid supplied to the inside of the balloon 100. Since the balloon catheter has a hub having a fluid injection part, it becomes easy to supply fluid to the inside of the balloon 100 to inflate and deflate the balloon 100. Further, when the balloon catheter is of an over-the-wire type, it is preferable to have a guide wire insertion portion communicating with a guide wire insertion path. Since the over-the-wire balloon catheter has a hub equipped with a guidewire insertion portion, it becomes easier to send the balloon catheter along the guidewire to the treatment target site.

Examples of joining the shaft and the hub include bonding with an adhesive, welding, and the like. Among these, it is preferable that the shaft and the hub are joined by adhesive. By bonding the shaft and the hub, for example, the shaft is made of a highly flexible material and the hub is made of a highly rigid material. Even if they are different, it is possible to increase the bonding strength between the shaft and the hub and increase the durability of the balloon catheter.

Examples of the material constituting the shaft include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, fluorine resin, vinyl chloride resin, silicone resin, and natural rubber. These may be used alone or in combination of two or more. Among these, the material constituting the shaft is preferably at least one of polyamide resin, polyolefin resin, and fluororesin. By using at least one of a polyamide resin, a polyolefin resin, and a fluorine resin as the material constituting the shaft, it is possible to increase the slipperiness of the surface of the shaft and improve the ability to insert the balloon catheter into a blood vessel. .

Balloon 100 is provided on the distal side of the shaft. Examples of joining the balloon 100 and the shaft include bonding with an adhesive, welding, and attaching a ring-shaped member to a portion where the balloon 100 and the shaft overlap and caulking. Among these, it is preferable that the balloon 100 and the shaft be joined by welding. By welding the balloon 100 and the shaft, the strength of the bond between the balloon 100 and the shaft can be increased, and even if the balloon 100 is repeatedly expanded and deflated, the bond between the balloon 100 and the shaft becomes difficult to come off.

Balloon 100 preferably has a straight tube section, a proximal tapered section connected to the proximal side of the straight tube section, and a distal tapered section connected to the distal side of the straight tube section. Preferably, the proximal tapered portion and the distal tapered portion are formed so that their diameters decrease as they move away from the straight pipe portion. Since the balloon 100 has a straight tube portion, the straight tube portion comes into sufficient contact with the stenosis, making it easier to dilate the stenosis. Furthermore, since the balloon 100 has a proximal tapered part and a distal tapered part whose outer diameter decreases as it moves away from the straight tube part, when the balloon 100 is deflated and wound around the shaft, the balloon 100 By making the outer diameters of the distal and proximal ends of the shaft smaller, the difference in level between the shaft and the balloon 100 can be reduced, making it easier to insert the balloon 100 in the distance direction. Note that in the present invention, the inflatable portion is considered to be the balloon 100.

Materials constituting the balloon 100 include, for example, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyester resins such as polyethylene terephthalate and polyester elastomers, polyurethane resins such as polyurethane and polyurethane elastomers, and polyphenylene sulfide resins. Examples include resins, polyamide elastomers, polyamide resins such as nylon 6, nylon 6/6, nylon 6/10, and nylon 12, fluorine resins, silicone resins, and natural rubbers such as latex rubber. These may be used alone or in combination of two or more. The material constituting the balloon 100 is preferably polyamide resin, and more preferably nylon 12. By using polyamide resin as the material constituting the balloon 100, it is possible to increase the flexibility of the balloon 100.

The outer diameter of the balloon 100 is preferably 0.5 mm or more, more preferably 1 mm or more, and even more preferably 1.5 mm or more. By setting the lower limit of the outer diameter of the balloon 100 within the above-mentioned range, it is possible to sufficiently dilate the narrowed portion within the blood vessel. Further, the outer diameter of the balloon 100 is preferably 35 mm or less, more preferably 30 mm or less, and even more preferably 25 mm or less. By setting the upper limit of the outer diameter of the balloon 100 within the above range, it is possible to prevent the outer diameter of the balloon 100 from increasing.

The length of the balloon 100 in the distance direction is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 15 mm or more. By setting the lower limit of the length of the balloon 100 in the far and near directions within the above range, it is possible to increase the area of the stenosis that can be expanded at one time, thereby shortening the time required for the procedure. Further, the length of the balloon 100 in the far and near directions is preferably 300 mm or less, more preferably 200 mm or less, and even more preferably 100 mm or less. By setting the upper limit of the length of the balloon 100 in the far and near directions within the above range, the amount of fluid sent into the inside of the balloon 100 for dilating the stenosis can be reduced, which is necessary for sufficiently dilating the balloon 100. time can be shortened.

The thickness of the balloon 100 is preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more. By setting the lower limit of the thickness of the balloon 100 within the above range, the strength of the balloon 100 can be increased and the stenotic region can be sufficiently dilated. Further, the upper limit of the thickness of the balloon 100 can be set depending on the use of the balloon catheter, and can be, for example, 100 μm or less, 90 μm or less, or 80 μm or less.

As shown in FIG. 2, the balloon 100 is provided with a protrusion 50 on the outer surface. Since the balloon 100 has the protrusion 50 on the outer surface, the protrusion 50 can crack a calcified and hardened lesion, and even if the lesion is calcified, the balloon 100 can sufficiently penetrate the lesion. can be expanded. Furthermore, by expanding the balloon 100 in an ISR lesion, the protrusion 50 is likely to catch on the neointima, which is soft and has a slippery surface, and the balloon 100 is less likely to be displaced when the ISR lesion is expanded.

The number of protrusions 50 may be one, but preferably a plurality. That is, it is preferable that a plurality of protrusions 50 be provided on the outer surface of the balloon 100. By having a plurality of protrusions 50, it becomes easier to crack a lesion hardened by calcification, and the balloon 100 is less likely to be misaligned with respect to an ISR lesion.

The protrusion 50 extends in the far and near directions. The length of the protrusion 50 in the distance direction is preferably shorter than the length of the balloon 100 in the distance direction. Since the length of the protrusion 50 in the distance direction is shorter than the length of the balloon 100 in the distance direction, the balloon 100 tends to bend because there is a part of the balloon 100 in the distance direction where the protrusion 50 is not provided. , it is possible to improve the insertability of the balloon catheter through curved blood vessels and the like.

The material constituting the protrusion 50 is, for example, polyolefin resin such as polyvinyl chloride, polyethylene, polypropylene, or cyclic polyolefin, polystyrene resin, polymethylpentene resin such as poly-(4-methylpentene-1), or polycarbonate. based resins, acrylic resins, ABS resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, butadiene-styrene copolymers, polyamide elastomers, nylon 6, nylon 6/6, nylon 6/10, nylon 12, etc. Examples include synthetic resins such as metals such as polyamide resins, stainless steel, aluminum, aluminum alloys, titanium, titanium alloys, copper, copper alloys, tantalum, and cobalt alloys. These materials may be used alone or in combination of two or more.

Preferably, the protrusion 50 is made of the same material as the balloon 100. Since the material forming the protrusion 50 is the same as the material forming the balloon 100, it is possible to increase the bonding strength between the balloon 100 and the protrusion 50.

Further, it is preferable that the balloon 100 and the protrusion 50 are integrally molded. Since the balloon 100 and the protrusion 50 are integrally molded, the process of joining the protrusion 50 to the balloon 100 is not necessary, so the time required to mold the balloon 100 can be shortened and manufacturing efficiency can be increased. .

The method for manufacturing a balloon catheter includes the step of preparing a cylindrical parison 10 having a protrusion 50 on its outer surface. The parison 10 is a cylindrical object made of synthetic resin, and the balloon 100 can be formed by pressurizing the inside of the parison 10 and expanding it.

In the step of preparing the parison 10, the parison 10 may be created by injection molding, but it is preferably created by extrusion molding. That is, it is preferable to include a step of preparing a cylindrical parison 10 having a protrusion 50 on the outer surface by extrusion molding. By creating the parison 10 by extrusion molding, it is possible to improve the efficiency of molding the parison 10, which is a cylindrical body having a protrusion 50 on the outer surface, and to improve the manufacturing efficiency of the balloon 100.

A method for manufacturing a balloon catheter includes preparing a mold 1 having a mold body 2 into which a parison 10 is inserted, and a movable part 3 provided in the mold body 2 and movable in the radial direction of the parison 10. Contains processes. The mold body 2 has a space inside, and the parison 10 can be placed in this internal space.

The method for manufacturing a balloon catheter includes the steps of arranging a protrusion 50 inside the movable part 3, as shown in FIG. 1, and expanding the parison 10 by pressurizing the inside of the parison 10, as shown in FIG. The process includes a step of causing In conventional manufacturing methods, as the parison expands, the position of the protrusion changes in the radial and circumferential directions of the parison, and the position of the protrusion becomes misaligned with the groove of the mold in which the protrusion is placed inside. This may cause the protruding part to be pressed against the inner surface of the mold, resulting in molding defects such as crushing or deformation of the protruding part of the balloon, or thinning of the balloon film near the protruding part. Ta. In the manufacturing method of the present invention, the mold 1 has the movable part 3 and includes the step of arranging the protruding part 50 of the parison 10 inside the movable part 3, thereby expanding the parison 10 and forming a balloon. When molding the parison 100, the protrusion 50 is disposed in the movable part 3 that is movable in the radial direction of the parison 10. Accordingly, the movable part 3 also moves in the radial direction of the parison 10, and since the inner part of the movable part 3 suppresses the movement of the protrusion part 50 in the circumferential direction of the parison 10, the protrusion part 50 moves inside the mold 1. phase shift is less likely to occur. Therefore, it becomes possible to mold the balloon 100 having the protrusion 50 with one mold 1.

Examples of methods for pressurizing the inside of the parison 10 include supplying a fluid such as a gas such as air or nitrogen gas, or a liquid such as pure water or physiological saline into the inside of the parison 10. For example, a pump or the like can be used to pressurize the fluid. Among the methods for pressurizing the inside of the parison 10, it is preferable to use compressed gas. That is, it is preferable to manufacture the balloon 100 by blow molding using the parison 10. By manufacturing the balloon 100 by feeding compressed gas into the parison 10 and pressurizing the inside thereof, the manufacturing efficiency of the balloon 100 can be increased.

The step of expanding the parison 10 may be performed at the same time as the step of arranging the protrusion 50 in the inner part of the movable part 3, but it should be performed after the step of arranging the protrusion 50 in the inner part of the movable part 3. is preferred. By performing the step of expanding the parison 10 after the step of arranging the protrusion 50 in the inner part of the movable part 3, the protrusion 50 expands into the movable part 3 of the mold 1 when pressurizing the inside of the parison 10. It can be made difficult to come off from the inner part.

As shown in FIG. 2, when the parison 10 has finished expanding, the movable part 3 is preferably positioned outward from the straight line L1 passing through the root of the protrusion 50 in a cross section perpendicular to the perspective direction of the parison 10. . Since the movable part 3 is located outward from the straight line L1 at the end of the expansion of the parison 10, the movable part 3 is difficult to bite into the root part of the protruding part 50, and the balloon 100 is not deformed or the balloon 100 is It is possible to prevent the thickness of the base portion of the protrusion 50 from becoming thinner due to the deformation of the protrusion 50, and to ensure a sufficient film thickness of the balloon 100 at the base portion of the protrusion 50. As a result, the pressure resistance of the balloon 100 can be improved. In addition, parts of the balloon 100 where the film thickness is thinner than other parts stretch more easily than other parts when the balloon 100 is expanded, so the balloon 100 may expand more than expected. It becomes difficult to adjust the outer diameter. By positioning the movable part 3 outward from the straight line L1 at the end of the expansion of the parison 10, it is possible to ensure a sufficient film thickness of the balloon 100 at the root portion of the protruding part 50, and the entire balloon 100 is becomes easier to expand uniformly.

When the parison 10 finishes expanding, the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 in a cross section perpendicular to the near and far direction of the parison 10 is the same as the thickness of the balloon 100, or The thickness is preferably less than 100 mm. By making the shortest distance between the movable part 3 and the straight line L1 passing through the base of the protruding part 50 at the end of the expansion of the parison 10 equal to or less than the film thickness of the balloon 100, the protruding part 50 of the molded balloon 100 is The movable part 3 is difficult to bite into the root part, and the root part of the protruding part 50 is prevented from extending too much outward when the parison 10 is expanded, and the film thickness at the root part of the protruding part 50 is made sufficient. 100 can be reduced and the manufacturing efficiency of the balloon 100 can be increased.

When the expansion of the parison 10 is completed, the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 in a cross section perpendicular to the distance direction of the parison 10 is less than or equal to one time the film thickness of the balloon 100. It is preferably 0.95 times or less, more preferably 0.9 times or less. By setting the upper limit of the ratio between the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 and the film thickness of the balloon 100 within the above range, the root of the protruding part 50 is The durability of the balloon 100 can be increased by preventing the portion from extending too far outward in the radial direction of the parison 10 and by making the base portion of the protruding portion 50 of the molded balloon 100 sufficiently thick. Furthermore, when the parison 10 finishes expanding, the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 in a cross section perpendicular to the near and far direction of the parison 10 is 0.5 times or more the film thickness of the balloon 100. It is preferably 0.55 times or more, more preferably 0.6 times or more. By setting the lower limit of the ratio of the shortest distance between the movable part 3 and the straight line L1 passing through the base of the protruding part 50 and the film thickness of the balloon 100 to the above range, the base part of the movable part 3 and the protruding part 50 is This makes it possible to maintain a sufficient distance between the balloon 100 and the protruding portion 50 of the balloon 100. As a result, it is possible to manufacture a balloon 100 with small deformation of the root portion of the protrusion 50 and sufficient pressure resistance.

It is preferable to include a step of holding the position of the movable part 3 after the step of pressurizing the inside of the parison 10 and expanding the parison 10. When the inside of the parison 10 is pressurized, the protruding portion 50 pushes the movable portion 3 outward in the radial direction of the parison 10 and moves it as the parison 10 expands. By holding the position of the movable part 3 at the time when the expansion of the parison 10 is completed, the movable part 3 is prevented from moving inward in the radial direction of the parison 10, and the protrusion of the balloon 100 after molding is prevented. It is possible to prevent the movable part 3 from unintentionally coming into contact with the parts 50 and the like, thereby preventing damage to the balloon 100 and deformation of the protruding part 50.

After the step of holding the position of the movable part 3, it is preferable to perform a step of expanding the parison 10 and taking out the molded balloon 100 from the mold 1. By performing the step of holding the position of the movable part 3 before taking out the balloon 100 from the mold 1, the protruding part 50 of the balloon 100 is less likely to get caught in the movable part 3, and the balloon 100 after molding can be easily taken out from the mold 1. Become.

FIG. 3 shows a sectional view perpendicular to the perspective direction of the mold 1 after the step of arranging the protrusion 50 in the inner part of the movable part 3 in another embodiment of the present invention. After the process of arranging the protruding part 50 in the inner part of the movable part 3, the protruding part 50 contacts the inner part of the movable part 3, thereby blocking the entrance of the inner part of the movable part 3. It is preferable to have an end region 51 and a distal end region 52 which is radially outward of the parison 10 from the base end region 51 and is separated from the inner part of the movable part 3. Since the protruding part 50 has the proximal region 51 and the distal end region 52, the protruding part 50 is not displaced from the movable part 3 because the proximal region 51 is in contact with the inner part of the movable part 3. Since the tip region 52 is not in contact with the inner part of the movable portion 3, the tip portion of the protrusion 50 is not easily crushed. Therefore, it is possible to mold the balloon 100 while protecting the tip shape of the protrusion 50 of the parison 10 before molding.

Since the base end region 51 is a portion that was in contact with the inner part of the movable part 3, the shape of the surface of the inner part of the movable part 3 is transferred to the surface of the base end region 51. On the other hand, since the tip region 52 is a portion separated from and not in contact with the inner portion of the movable portion 3, the shape of the surface of the inner portion of the movable portion 3 is not transferred to the surface of the tip region 52. Therefore, by observing the cross-section of the balloon 100 perpendicular to the far and near direction of the balloon 100 after molding using a microscope, the proximal region 51, the distal region 52, and the boundary between the proximal region 51 and the distal region 52 can be confirmed. can do.

It is also preferable that, after the step of arranging the protrusion 50 in the inner part of the movable part 3, the movable part 3 has a step of pressing the protrusion 50 inward of the mold 1. Since the movable part 3 has the step of pressing the protruding part 50 inward of the mold 1, when molding the balloon 100, the protruding part 50 is pressed against the movable part 3 and pressure is applied to the protruding part 50 from the outside. This makes it possible to increase the hardness of the protrusion 50. As a result, a balloon catheter with high expansion power for calcified lesions and the like can be obtained.

It is preferable that the process in which the movable part 3 presses the protruding part 50 toward the inside of the mold 1 is performed at the same time as the process in which the inside of the parison 10 is pressurized and the parison 10 is expanded. That is, when the inside of the parison 10 is pressurized to expand the parison 10, the force of the parison 10 trying to expand outward in the radial direction is used to press the protruding part 50 against the movable part 3 and press the mold 1. It is preferable to press inward. By simultaneously carrying out the process in which the movable part 3 presses the protruding part 50 inward into the mold 1 and the process in which the inside of the parison 10 is pressurized to expand the parison 10, the time required to form the balloon 100 is shortened. This increases production efficiency.

In the step of pressurizing the inside of the parison 10 and expanding the parison 10, it is preferable to include a step of heating the movable part 3. By heating the movable part 3 in the step of pressurizing the inside of the parison 10 to expand the parison 10, heat is applied to the protruding part 50 of the parison 10 to soften it, and the protruding part is brought into contact with the inner surface of the movable part 3. Since the shape of the protruding portion 50 can be made close to the shape of the inner surface of the movable portion 3, it is possible to make the protruding portion 50 have a shape suitable for the lesion.

In the step of heating the movable part 3, the temperature of the movable part 3 is preferably higher than the temperature of the mold body 2. Since the temperature of the movable part 3 is higher than the temperature of the mold body 2, the temperature of the movable part 3 in contact with the protruding part 50, which is thicker than the membrane part of the balloon 100, is higher than that of the mold body 2 in contact with the membrane part of the balloon 100. can be made high, and the protruding portion 50 can be heated efficiently.

It is preferable that the process of heating the movable part 3 is performed at the same time as the process of the movable part 3 pressing the protruding part 50 toward the inside of the mold 1. By simultaneously performing the process of heating the movable part 3 and the process of causing the movable part 3 to press the protruding part 50, the protruding part 50 is heated and softened while being pressed against the inner surface of the movable part 3. The shape of the movable part 3 can be easily molded to match the shape of the inner surface of the movable part 3.

In the process of pressurizing the inside of the parison 10 and expanding the parison 10, it is also preferable that the temperature of the movable part 3 is lower than the temperature of the mold body 2. Since the temperature of the movable part 3 is lower than the temperature of the mold body 2, it is possible to press the protrusion part 50 against the movable part 3 and apply pressure from the outside, thereby further increasing the hardness of the protrusion part 50.

It is preferable to include a step of cooling the movable part 3 after the step of pressurizing the inside of the parison 10 and expanding the parison 10. By cooling the movable part 3 after the step of pressurizing the inside of the parison 10 to expand the parison 10, the hardness of the protruding part 50 is increased, and a balloon catheter that can easily incise a calcified lesion can be obtained.

The process of cooling the movable part 3 is preferably performed after the process of the movable part 3 pressing the protruding part 50 toward the inside of the mold 1 and the process of heating the movable part 3. After the movable part 3 performs the process of pressing the protrusion part 50 inward of the mold 1 and the process of heating the movable part 3, the movable part 3 is cooled to produce a heated and softened protrusion. After the part 50 is pressed against the inner surface of the movable part 3 and molded, the molded protrusion part 50 can be immediately cooled and solidified by the cooled movable part 3.

Preferably, after the step of arranging the protrusion 50 in the inner part of the movable part 3, there is a step of coating the protrusion 50. By applying a coating to the protrusion 50, it is possible to improve the slidability and hardness of the protrusion 50.

Examples of the coating applied to the protrusion 50 include a hydrophilic coating, a diamond coating to which diamond particles are attached, and the like. When the protrusion 50 is coated with a hydrophilic coating, the slipperiness of the protrusion 50 of the balloon 100 is improved, and the balloon catheter can be easily passed through a narrowed lesion. Further, when the protrusion 50 is coated with diamond, the hardness of the protrusion 50 of the balloon 100 increases, making it easier to scrape off calcified lesions, thereby increasing the expansion force of the balloon catheter even in calcified lesions. Can be done.

It is preferable that the step of coating the protruding portion 50 is performed after the step of the movable portion 3 pressing the protruding portion 50 toward the inside of the mold 1. By coating the protruding part 50 after the movable part 3 presses the protruding part 50 toward the inside of the mold 1, the coated protruding part 50 and the movable part 3 are unlikely to come into contact with each other. becomes difficult to peel off from the protruding portion 50.

Further, it is preferable that the step of coating the protruding portion 50 is performed after the step of pressurizing the inside of the parison 10 and expanding the parison 10. By coating the protrusion 50 after expanding the parison 10, the coating applied to the protrusion 50 is less affected by changes in the shape of the parison 10 when the parison 10 is expanded, and the coating is removed from the protrusion 50. It becomes difficult to peel off.

Next, the mold 1 of the present invention will be explained. In addition, in the description of the mold 1, the description of parts that overlap with the description of the method for manufacturing the balloon catheter described above will be omitted.

As shown in FIGS. 1 and 2, the mold 1 of the present invention is a hollow mold 1 into which a cylindrical parison 10 having a protrusion 50 on the outer surface is inserted, and the mold body 2, and a movable part 3 that is movable in the radial direction of the parison 10 inserted.

The mold 1 is hollow, and a cylindrical parison 10 having a protrusion 50 on the outer surface is placed in the internal space of the mold 1. A balloon catheter can be molded by placing the parison 10 inside the mold 1 and expanding the parison 10.

The mold 1 has a mold body 2 and a movable part 3. The movable part 3 is provided in the mold body 2 and can move in the radial direction of the cylindrical parison 10 inserted into the mold 1. Since the mold 1 has a mold body 2 and a movable part 3 that is a separate part from the mold body 2, the movable part 3 can be processed as a separate part from the mold body 2. For example, the movable part 3 can be manufactured by cutting the movable part 3 in a cutting direction suitable for machining the inner part of the movable part 3, and the protruding part 50 can be formed into a desired shape according to the purpose. It becomes easier to do so.

As for the movable part 3, it is preferable that the protrusion part 50 is arrange|positioned at the inner part of the movable part 3. Since the movable part 3 is movable in the radial direction of the parison 10 and the protruding part 50 is disposed inside the movable part 3, when pressurizing the inside of the parison 10 in the mold 1, The movable part 3 moves in the radial direction of the parison 10 as the parison 10 expands. Therefore, a phase shift of the protruding portion 50 before and after the expansion of the parison 10 is unlikely to occur, and the balloon 100 can be molded with one mold 1, thereby increasing the manufacturing efficiency of the balloon catheter.

As shown in FIG. 2, in the movable range of the movable part 3, when the movable part 3 is placed at the outermost position, the movable part 3 is a straight line passing through the root of the protruding part 50 in a cross section perpendicular to the perspective direction of the parison 10. It is preferable that it be located outward from L1. Since the movable part 3 is located outward from the straight line L1 passing through the base of the protrusion 50, the movable part 3 is difficult to bite into the base of the protrusion 50 when the parison 10 is expanded, and the balloon 100 Since it is possible to prevent the balloon 100 from being deformed and the thickness of the base portion of the protrusion 50 from becoming thinner due to the deformation of the balloon 100, the film thickness of the balloon 100 at the base portion of the protrusion 50 can be ensured. It becomes possible to improve the pressure resistance of the balloon 100.

In the movable range of the movable part 3, when the movable part 3 is placed at the outermost position, the shortest distance between the movable part 3 in a cross section perpendicular to the perspective direction of the parison 10 and the straight line L1 passing through the root of the protrusion 50 is , is preferably the same as the film thickness of the balloon 100 or smaller than the film thickness of the balloon 100. By making the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 equal to or less than the film thickness of the balloon 100, it is possible to prevent the movable part 3 from digging into the root part of the protruding part 50 and the possibility of the parison 10 This prevents the root portion of the protrusion 50 from extending too far outward during expansion, and ensures a sufficient film thickness of the balloon 100 at the root portion of the protrusion 50. The defective rate due to insufficient film thickness of the balloon 100 can be reduced, and the manufacturing efficiency of the balloon 100 can be increased.

In the movable range of the movable part 3, when the movable part 3 is placed at the outermost position, the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 in a cross section perpendicular to the perspective direction of the parison 10 is as follows: It is preferably at most 1 time the film thickness of the balloon 100, more preferably at most 0.95 times, even more preferably at most 0.9 times. By setting the upper limit of the ratio between the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 and the film thickness of the balloon 100 within the above range, the root of the protruding part 50 is The durability of the balloon 100 can be increased by preventing the portion from extending too far outward in the radial direction of the parison 10 and by making the base portion of the protruding portion 50 of the molded balloon 100 sufficiently thick. In addition, in the movable range of the movable part 3, when the movable part 3 is placed at the outermost position, the shortest distance between the movable part 3 and the straight line L1 passing through the root of the protruding part 50 in a cross section perpendicular to the perspective direction of the parison 10. is preferably 0.5 times or more, more preferably 0.55 times or more, and even more preferably 0.6 times or more the film thickness of the balloon 100. By setting the lower limit of the ratio between the shortest distance between the movable part 3 and the straight line L1 passing through the base of the protruding part 50 and the film thickness of the balloon 100 within the above range, the movable part 3 and the protruding part can be prevented when the parison 10 is expanded. A sufficient distance can be provided between the protruding portion 50 and the root portion of the balloon 100, and a sufficient film thickness can be ensured at the root portion of the protruding portion 50 of the balloon 100. Therefore, it is possible to manufacture a balloon 100 that has sufficient pressure resistance and that deforms little at the root portion of the protrusion 50 when the balloon catheter is used.

Although not shown, it is preferable that the mold 1 has a holding mechanism for holding the position of the movable part 3. Since the mold 1 has a holding mechanism, for example, by holding the position of the movable part 3 with the movable part 3 disposed at the outermost position in the movable range of the movable part 3, the movable part 3 can be prevented from moving inward in the radial direction of the parison 10, and the movable part 3 can be prevented from coming into contact with the balloon 100 after molding and damaging the balloon 100. Examples of the holding mechanism for holding the position of the movable part 3 include those that fix the movable part 3 with parts such as screws and pins.

Further, although not shown, it is preferable that the mold 1 has a pressing mechanism that presses the movable part 3 toward the inside of the mold body 2. Since the mold 1 has a pressing mechanism, when molding the balloon 100, pressure can be applied from the outside to the part where the parison 10 and the movable part 3 contact, for example, while pressing the protruding part 50. By performing molding to increase the hardness of the protrusion 50, it is possible to manufacture a balloon catheter with a high expansion force into a calcified lesion.

As shown in FIG. 1, the mold 1 includes a movable mechanism 4 disposed outside the movable part 3 in the radial direction of the mold body 2, and the movable mechanism 4 has a spring 4a disposed therein. is preferred. The movable mechanism 4 is a mechanism for moving the movable part 3 in the radial direction of the parison 10. Since the mold 1 has the movable mechanism 4 in which the spring 4a is arranged, the protrusion 50 contacts the movable part 3 due to the expansion of the parison 10, and the movable part 3 moves outward in the radial direction of the parison 10. When pressed, the movable part 3 can smoothly move outward in the radial direction of the parison 10 due to the contraction of the spring 4a. Further, since the movable part 3 presses the protrusion 50 by the repulsive force of the spring 4a, the balloon 100 can be molded while applying pressure to the protrusion 50, and the hardness of the protrusion 50 can be easily increased.

When the movable mechanism 4 has a spring 4a, as shown in FIG. 1, the movable mechanism 4 has a cylindrical member 4b, and the spring 4a is arranged in the inner cavity of the cylindrical member 4b. is preferred. By disposing the spring 4a in the inner cavity of the cylindrical member 4b, the cylindrical member 4b prevents the position of the spring 4a from shifting, and when the spring 4a contracts, the position of the movable part 3 becomes difficult to shift. It becomes possible to make it difficult for the protruding part 50 to come off from the inner part of the part 3.

Moreover, it is also preferable that the movable mechanism 4 has fluid. That is, in the mold 1, the movable mechanism 4 is disposed outside the movable part 3 in the radial direction of the mold body 2, and it is preferable that the movable mechanism 4 is disposed with a fluid. Examples of the fluid include air, water, oil, etc., and may be compressed. Since the movable mechanism 4 has fluid, the speed at which the movable part 3 is moved radially outward and radially inward of the parison 10 can be easily adjusted, and the movable part 3 can be smoothly moved. Can be done. In addition, by increasing the pressure of the fluid in the movable mechanism 4, the movable part 3 can press the protrusion 50 and apply pressure to the protrusion 50 during molding of the balloon 100, and the hardness of the protrusion 50 can also be increased. It is possible.

As shown in FIG. 1, the movable part 3 has a groove 20, and the depth d1 of the groove 20 is preferably smaller than the height H1 of the protrusion 50. Since the depth d1 of the groove 20 of the movable part 3 is smaller than the height H1 of the protrusion 50, when the protrusion 50 is disposed inward of the movable part 3, the movable part 3 is located at the base of the protrusion 50. becomes less likely to interfere with As a result, it is possible to ensure a sufficient film thickness at the root portion of the protrusion 50, where the film thickness of the balloon 100 tends to be thin, and it is possible to improve the pressure resistance performance of the balloon 100.

The depth d1 of the groove 20 is preferably 90% or less of the height H1 of the protrusion 50, more preferably 85% or less of the height H1 of the protrusion 50, and preferably 80% or less. More preferred. By setting the upper limit of the ratio between the depth d1 of the groove 20 and the height H1 of the protrusion 50 within the above range, the groove 20 of the movable part 3 can sufficiently hold the protrusion 50 while The movable portion 3 is less likely to interfere with the root portion of the protruding portion 50, and the thickness of the balloon 100 at the root portion of the protruding portion 50 can be made sufficient. Furthermore, the depth d1 of the groove 20 is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more of the height H1 of the protrusion 50. By setting the lower limit of the ratio of the depth d1 of the groove portion 20 to the height H1 of the protruding portion 50 within the above range, the protruding portion 50 can be easily arranged inside the movable portion 3, and the parison 10 can be easily disposed. A phase shift of the protruding portion 50 is less likely to occur during expansion.

The average surface roughness Rz of the inner part of the movable part 3 is preferably larger than the average surface roughness Rz of the inner surface of the mold body 2. Since the average surface roughness Rz of the inner part of the movable part 3 is larger than the average surface roughness Rz of the inner surface of the mold body 2, the surface of the protrusion 50 in contact with the surface of the inner part of the movable part 3 is The surface of the balloon 100 can be made rougher than other parts of the balloon 100. Therefore, it is possible to manufacture a balloon catheter in which the surface of the protrusion 50 has a high frictional force and the protrusion 50 does not easily slip from the lesion.

It is also preferable that the average surface roughness Rz of the inner part of the movable part 3 is smaller than the average surface roughness Rz of the inner surface of the mold body 2. Since the average surface roughness Rz of the inner part of the movable part 3 is smaller than the average surface roughness Rz of the inner surface of the mold body 2, the protrusion 50 is smaller than the outer surface of the other parts of the balloon 100. The outer surface of the balloon catheter can be smoothed, and the balloon catheter can be easily inserted into a lumen in a living body such as a blood vessel.

The movable part 3 has a groove 20, and it is preferable that the groove 20 has portions with different groove depths in the axial direction of the mold body 2. That is, it is preferable that the depth of the groove portion 20 is not constant in the axial direction of the parison 10. Since the movable portion 3 has the groove portion 20 having portions with different groove depths, the height of the protrusion portion 50 can be changed according to the depth of the groove portion 20. Since the protruding part 50 is configured to have portions with different heights, the protruding part 50 easily bites into the lesion, resulting in a balloon catheter that is difficult to come off from the lesion and easily cracks the calcified lesion.

The movable part 3 has a groove part 20, and it is preferable that the groove part 20 has an interrupted part in the axial direction of the mold body 2. Since the groove portion 20 has the discontinuous portion, the protruding portion 50 located at the discontinuous portion is crushed and becomes lower in height, or the protruding portion 50 is partially eliminated. Therefore, in the axial direction of the mold body 2, it is possible to manufacture a balloon 100 having a configuration in which the protrusion portions 50 have different heights or a plurality of protrusion portions 50.

In the axial direction of the mold body 2, it is preferable that a plurality of movable parts 3 exist. That is, it is preferable that the mold 1 has a plurality of movable parts 3 in the axial direction of the mold body 2. Since there are a plurality of movable parts 3 in the axial direction of the mold body 2, the protrusion part 50 of the parison 10 is crushed during molding in the part of the mold 1 where the movable part 3 is not present, and the axis of the mold body 2 Balloons 100 can be manufactured with multiple protrusions 50 in the direction.

Although not shown, in the axial direction of the mold body 2, the mold body 2 has a straight pipe part and tapered parts on both sides of the straight pipe part, and the straight pipe part has a movable part 3. It is preferable that the movable part 3 is not arranged in the tapered part. Since the mold body 2 has a straight tube part and a tapered part, it is possible to manufacture a balloon 100 whose both ends are tapered in the far and near directions. Furthermore, since the straight pipe part of the mold body 2 has the movable part 3 and the tapered part does not have the movable part 3, the balloon 100 has a straight pipe part which has the protrusion part 50, The tapered portion of the balloon 100 is not provided with the protruding portion 50, making it possible to provide the balloon 100 with high insertion performance and a high ability to expand the lesion area.

As described above, the method for manufacturing a balloon catheter includes a shaft extending in the far-to-near direction, and a balloon provided on the distal side of the shaft and having a protrusion on the outer surface. The manufacturing method includes the steps of preparing a cylindrical parison having a protrusion on the outer surface, a mold body into which the parison is inserted, and a mold body provided on the mold body and movable in the radial direction of the parison. A process of preparing a mold having a movable part, a process of arranging a protrusion part inside the movable part, and a process of pressurizing the inside of the parison to expand the parison. The mold is a hollow mold into which a cylindrical parison having a protrusion on the outer surface is inserted, and the mold body and the inserted parison are movable in the radial direction. The movable part has a protruding part disposed inside the movable part. By using a mold that has a movable part that is movable in the radial direction of the parison and arranging the protruding part of the parison inside the movable part, a phase shift of the protruding part of the parison occurs before and after the expansion of the parison. This makes it possible to mold the balloon in one step, thereby improving the manufacturing efficiency of the balloon catheter.

1: Mold 2: Mold body 3: Movable part 4: Movable mechanism 4a: Spring 4b: Cylindrical member 10: Parison 20: Groove 50: Projection 51: Base region 52: Tip region 100: Balloon L1: Movable A straight line passing through the base of the part and the protruding part d1: Depth of the groove H1: Height of the protruding part

Claims (20)

A method for manufacturing a balloon catheter having a shaft extending in a distance direction, and a balloon provided on a distal side of the shaft and having a protrusion on an outer surface, the method comprising:
preparing a cylindrical parison having a protrusion on its outer surface;
preparing a mold having a mold body into which the parison is inserted; and a movable part provided in the mold body and movable in a radial direction of the parison;
arranging the protrusion in the inner part of the movable part;
pressurizing the inside of the parison to expand the parison ;
After the step of arranging the protrusion in the inner part of the movable part, the protrusion has a base that blocks the entrance of the inner part of the movable part by contacting the inner part of the movable part. A method for manufacturing a balloon catheter , the balloon catheter having an end region, and a distal end region that is radially outward of the parison from the proximal end region and is separated from the inner part of the movable part . 2. The method for manufacturing a balloon catheter according to claim 1, wherein when the parison finishes expanding, the movable part is located outward from a straight line passing through the root of the protrusion in a cross section perpendicular to the far and near direction of the parison. . 3. The method for manufacturing a balloon catheter according to claim 1, further comprising the step of maintaining the position of the movable part after the step of pressurizing the inside of the parison and expanding the parison. Any one of claims 1 to 3, wherein the movable part has a step of pressing the protrusion inward of the mold after the step of arranging the protrusion in the inner part of the movable part. 2. The method for manufacturing a balloon catheter according to item 1. 5. The method for manufacturing a balloon catheter according to claim 1, further comprising the step of heating the movable part in the step of pressurizing the inside of the parison and expanding the parison. 6. The method for manufacturing a balloon catheter according to claim 1, further comprising the step of cooling the movable part after the step of pressurizing the inside of the parison and expanding the parison. The method for manufacturing a balloon catheter according to any one of claims 1 to 6 , further comprising the step of applying a coating to the protrusion after the step of arranging the protrusion in the inner part of the movable part. A hollow mold into which a cylindrical parison having a protrusion on the outer surface is inserted,
The mold body,
a movable part that is movable in the radial direction of the parison inserted ,
The protrusion is arranged in an inner part of the movable part,
When the protruding part is arranged in the inner part of the movable part, the protruding part has a proximal end that blocks the entrance of the inner part of the movable part by abutting against the inner part of the movable part. and a distal end region that is radially outward of the parison from the proximal end region and is spaced apart from the inner part of the movable part . In the movable range of the movable part, when the movable part is placed at the outermost position, the movable part is located further outward than a straight line passing through the root of the protrusion in a cross section perpendicular to the distance direction of the parison. 9. The mold according to claim 8 , wherein: The mold according to claim 8 or 9, further comprising a holding mechanism that holds the position of the movable part. The mold according to any one of claims 8 to 10, further comprising a pressing mechanism that presses the movable portion inward of the mold body. A movable mechanism is disposed outside the movable part in the radial direction of the mold body,
The mold according to any one of claims 8 to 11 , wherein the movable mechanism is provided with a spring. A movable mechanism is disposed outside the movable part in the radial direction of the mold body,
The mold according to any one of claims 8 to 11 , wherein the movable mechanism contains a fluid. The movable part has a groove,
The mold according to any one of claims 8 to 13 , wherein the depth of the groove is smaller than the height of the protrusion. The mold according to any one of claims 8 to 14 , wherein the average surface roughness Rz of the inner part of the movable part is larger than the average surface roughness Rz of the inner surface of the mold body. The mold according to any one of claims 8 to 14 , wherein the average surface roughness Rz of the inner part of the movable part is smaller than the average surface roughness Rz of the inner surface of the mold body. The movable part has a groove,
The mold according to any one of claims 8 to 16 , wherein the groove portion has portions with different groove depths in the axial direction of the mold body. The movable part has a groove,
The mold according to any one of claims 8 to 17 , wherein the groove portion has a discontinuous portion in the axial direction of the mold body. The mold according to any one of claims 8 to 18 , wherein a plurality of the movable parts exist in the axial direction of the mold body. In the axial direction of the mold body, the mold body has a straight pipe part and tapered parts on both sides of the straight pipe part,
The movable part is arranged in the straight pipe part,
The mold according to any one of claims 8 to 19 , wherein the movable part is not arranged in the tapered part.

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