JP4752657B2 - Catheter balloon and manufacturing method thereof - Google Patents

Description

  The present invention relates to a catheter balloon and a method for manufacturing the same, and more particularly to a catheter balloon and a method for manufacturing the same that improve the passage of a lesioned part in a shape that allows the balloon part to be easily inflated and contracted.

2. Description of the Related Art Conventionally, dilatation catheters having a balloon that expands a blood vessel by being inserted into the blood vessel and inflated are known as medical instruments for treating occlusion and stenosis of a patient's blood vessel. Also, the desired size and physical properties of the balloon vary depending on the size of the patient's blood vessel and the balloon application.
Usually, as a method for forming a balloon used for a balloon catheter for dilatation, for example, a thin-walled tubular parison (preliminary product) of a stretchable semi-crystalline polymer is prepared, and the primary transition temperature is determined from the secondary transition temperature of the polymer. In the temperature range up to the above, a method has been proposed in which the parison is stretched in the axial direction and then the stretched parison is expanded in the radial direction and cooled to a temperature equal to or lower than the second order transition temperature to form a balloon (for example, , See Patent Document 1).
In addition, a method has been proposed in which a parison is preliminarily adjusted in a preconditioning mold, and a balloon is formed with a balloon mold having a balloon mold inner diameter larger than the inner diameter of the preconditioning mold (see, for example, Patent Document 2).

Japanese Examined Patent Publication No. 63-26655 (page 1-4, Fig. 1) Japanese Patent Laid-Open No. 10-314311 (page 1-7, FIG. 2)

However, the conventional balloon produced by expanding and expanding to a predetermined range in the temperature range from the second order transition temperature to the first order transition temperature of the polymer and cooling to the second order transition temperature or lower is more than the balloon body part. As a result, the connecting portion and the tapered portion become thick, and as a result, the tapered portion and the connecting portion become hard at the time of the balloon catheter.
Further, in the manufacturing method described in Patent Document 2 using a pre-adjustment mold and a balloon mold, after the parison is inflated and cooled in the pre-adjustment mold, an exchange operation is required to transfer to the balloon mold, and the balloon molding process is complicated. It becomes.

  An object of the present invention is to use a balloon catheter for dilatation which can form a catheter balloon by a simple manufacturing method and has a thin balloon connection part and a tapered part to improve the passage of a lesioned part in order to solve the above problems. It is to provide a possible catheter balloon and its manufacturing method.

In order to achieve the above object, the invention according to claim 1 is to attach a tube-shaped parison, which is a preformed product, to a mold having a balloon part mold having a predetermined inner diameter, a taper part mold, and small diameter hole molds at both ends. A balloon for catheter having a balloon portion and a small-diameter connecting portion extending through a tapered portion on both sides of the balloon portion, the both sides of the tubular parison being Stretching at a predetermined ratio, forming a prepared parison in a state where an unstretched portion of a predetermined width is left in the center, and mounting it in the mold, to a first molding temperature not lower than the secondary transition temperature and not higher than the primary transition temperature. Heating, allowing the pressurized fluid to flow into the preparatory parison and performing primary stretching to primarily form a balloon shape having a balloon portion, a taper portion, and a small-diameter connection portion matching the inner surface shape of the mold, Mold, A secondary molding is performed in which the tapered portion and the connecting portion are thinned by a step of heating to a second molding temperature not lower than the first molding temperature and not higher than the primary transition temperature and a step of re-stretching both sides of the parison. It is characterized by.
According to the invention according to claim 1 having the above-described configuration, after performing the primary molding in which the preparatory parison having an unstretched portion having a predetermined shape is heated and expanded and primarily stretched to mold the balloon portion, Since the secondary molding is performed to re-stretch the connecting part, it is possible to form a balloon with an accurate outer shape that matches the mold, and to manufacture a thin balloon for a catheter that can be used for an expansion balloon catheter with improved lesion passage. be able to.

The invention according to claim 2 is characterized in that the width of the unstretched portion remaining in the central portion is 0.3 to 0.7 times the length of the balloon portion.
According to the invention concerning Claim 2 which has the above-mentioned composition, it can be set as the preparation parison suitable for manufacturing the balloon catheter which has the balloon part and taper part of predetermined diameter and length.

The invention according to claim 3 is characterized in that, after the primary molding, the connecting portion and the tapered portion are heated to a third molding temperature that is higher than the first molding temperature and lower than the primary transition temperature.
According to the invention which concerns on Claim 3 which has said structure, a softened taper part and a connection part can be extended and made thin at the process of redrawing.

The invention according to claim 4 is characterized in that after the primary molding, the balloon part is cooled and then heated to the second molding temperature.
According to the invention according to claim 4 having the above-described configuration, it is possible to extend only the tapered portion and the connecting portion without softening the already thinned balloon portion. Thinly molded.

The invention according to claim 5 is manufactured by the method for manufacturing a catheter balloon according to any one of claims 1 to 4, and has a small-diameter connection extending through a tapered portion on both sides of the balloon portion and the balloon portion. A balloon for a catheter having a portion, wherein the thickness of the tapered portion and the connecting portion is as thin as the thickness of the balloon portion.
According to the invention which concerns on Claim 5 which has said structure, a taper part and a small diameter connection part are made thin about the same thickness as a thin balloon part, and the balloon for catheters which improved the lesioned part passage property can be obtained.

  According to the present invention, after heating to the first molding temperature and primary molding into a balloon shape having a balloon portion, a taper portion, and a small diameter connecting portion, the temperature is not less than the first molding temperature without replacing the mold. Since it is configured to perform secondary molding in which the connecting portion is thinned by the step of heating to a second molding temperature not higher than the primary transition temperature and the step of re-stretching both sides of the parison, it is easy to replace the mold. A catheter balloon can be formed by the production method, and the balloon connection portion and the taper portion are thinned to obtain a catheter balloon that can be used for an expansion balloon catheter with improved lesion passage ability, and a method for producing the same.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a catheter balloon and a method for producing the same according to the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a catheter balloon 1 according to the present invention includes a balloon part 11 that is a main body part that expands and contracts, a tapered part 12 that is connected to both sides of the balloon part 11, and a small-diameter connecting part 13. It is an inflatable / retractable hollow member having a shape. Therefore, as this balloon material, polyolefins such as polyethylene and polypropylene, thermoplastic elastomers such as polyvinyl chloride, polyurethane and polyamide elastomer, silicon rubber, racex rubber and the like can be used.

When the catheter balloon 1 is manufactured, a thin tube-shaped parison 1A, which is an extruded preform shown in FIG. 3, is inserted into the mold 2 shown in FIG. Manufactured through a stretching process. Moreover, when heating, it is preferable that it is more than the secondary transition temperature and below the first transition temperature of the resin polymer to be used. In this temperature range, the parison is in a softened state, and can be easily stretched in the axial direction or expanded in the radial direction with the internal pressure being high.
The mold 2 includes a balloon part mold 2a having a predetermined inner diameter and a predetermined length L2, a balloon part mold 2a, a taper part mold 2b, and small diameter hole molds 2c at both ends. The mold 2 may be divided so as to take out the molded catheter balloon (see FIG. 6).
When the parison is mounted on the mold 2, both ends of the parison 1A are stretched to form a narrow parison stretched portion 1Ba, and a prepared parison 1B having an unstretched portion 1Bb at the center (see FIG. 4). Is used.

  For example, the diameter of the parison stretched portion 1Ba is stretched to be about 0.3 to 0.9 times the diameter of the unstretched portion 1Bb. As described above, the film is heated to a temperature not lower than the first order transition temperature and not higher than the first order transition temperature of the resin polymer to be used, and only the part to be stretched needs to be heated. In addition, it is preferable to cool the unstretched portion because the length L of the unstretched portion can be easily controlled.

Although it is clear that the length L of the unstretched portion is shorter than the length L2 of the balloon mold 2a of the mold 2 shown in FIG. 2, when the unstretched portion 1Bb is heated and stretched, It is preferable that both ends of the unstretched portion have a length that contacts the tapered portions in the molds 22 and 23.
Therefore, in the present embodiment, the length L of the unstretched portion is 0 as the length L2 of the balloon mold 2a of the mold 2 (the same as the balloon portion length L1 of the catheter balloon 1 shown in FIG. 1). About 3 to 0.7 times.
After the preparation parison 1B is mounted on the mold 2, one end of the parison is closed. As the closing method, heat melting, high-frequency blocking, forceps blocking, or the like can be used. After one end is closed and heated, a pressurized fluid is introduced from the other end and expanded. Examples of the pressurized fluid include compressed air and compressed nitrogen.

The heating temperature of the mold is set to a first molding temperature which is not lower than the second order transition temperature of the parison and not higher than the first order transition temperature. That is, the prepared parison 1B is heated to a first molding temperature that is higher than the second order transition temperature and lower than the first order transition temperature, and a heated fluid is flowed into the prepared parison so that the balloon portion and the taper that match the inner surface shape of the mold Primary forming into a balloon shape having a portion and a small diameter connecting portion.
With this primary molding, a balloon for a catheter having a balloon portion having a predetermined inner diameter and a small-diameter connection portion extending on both sides of the balloon portion via a tapered portion can be formed. However, the balloon body part that is inflated to a large diameter can be formed as thin as it is, but the connection part and the taper part that are not inflated to a large diameter as the balloon body part are not sufficiently thin and remain thick. , May become stiff. Therefore, in this embodiment, after the primary molding, the mold is heated to a second molding temperature not lower than the first molding temperature and not higher than the primary transition temperature, and the both sides of the parison are stretched again. The taper part and the connection part are configured to be thinned.

  In other words, after preparing the parison having an unstretched portion in a mold, heating and pressurizing and primary stretching to form a balloon main body and a tapered portion, without cooling the parison, Without changing the mold, the parison is heated to the second molding temperature and subjected to secondary molding in which re-stretching is performed while maintaining the internal pressure, thereby thinning the connecting portion and the tapered portion. .

This manufacturing process will be described in more detail with reference to FIG.
FIG. 6A shows a state where the preparation parison 1 </ b> B having the unstretched portion 1 </ b> Bb at the center is attached to the mold 2. The mold 2 is configured by combining a balloon part mold 21 that forms a balloon mold having a predetermined inner diameter 21a, a tapered part mold, and end molds 22 and 23 having small diameter hole molds at both ends.
The diameters of the small-diameter hole mold 22a of the end mold 22 and the small-diameter hole mold 23a of the end mold 23 are set to a size corresponding to the diameter of the tube connected to the balloon catheter after the product.
The mold 2 is configured to be integrally heated from its periphery by the heating means 3 shown in FIG. As the heating means 3, for example, an electrically controllable heater can be used. Further, if the heating means 3 is divided into three parts and constituted by the balloon part heating means 3B and the end part heating means 3A, 3A, the temperature of the balloon part, the taper part and the connecting part of the parison can be controlled independently. It is.

While heating from the state shown in FIG. 6A to a first molding temperature not lower than the first transition temperature of the parison but lower than the first transition temperature, one end of the parison is closed, and a pressurized fluid is allowed to flow in to expand. It extends | stretches in the arrow A direction in a figure. Then, as shown in FIG. 6 (b), the balloon portion 11 and the tapered portion which are inflated to a predetermined inner diameter corresponding to the balloon portion die, the tapered portion die and the small diameter hole portion die, and the respective small diameter connecting portions. A primary molded parison 1C having 13A and 13B can be molded.
However, in the primary molded parison 1C, the taper portion and the connection portion shown in the region B in the figure remain thick and may not be thin enough to be easily deformed. In the primary molded product, it is difficult to form a dilatation balloon catheter with improved lesion passage ability.

For this purpose, as shown in FIG. 6 (c), after the primary molding, the mold 2 is heated to a second molding temperature not lower than the first molding temperature and not higher than the primary transition temperature, and both sides of the parison. In the step of re-stretching in the direction of arrow C, secondary forming is performed in which the connecting portion is thin.
By re-stretching while maintaining the internal pressure in this manner, a secondary balloon product having a predetermined shape corresponding to the balloon mold 21 of the mold 2, the tapered portion, and the small-diameter hole portions at both ends is obtained. Molded parison 1D (becomes a catheter balloon 1) can be molded.
Further, the taper portion and the connection portion in the region B are heated to a predetermined temperature and re-stretched in a state where the internal pressure is maintained, so that the balloon die 21 of the die 2 and the taper portion and the small-diameter hole portions at both ends are adapted. A secondary molded parison 1D (becomes a catheter balloon 1) that is a balloon secondary molded product having a predetermined shape can be molded.
Further, the taper portion and the connection portion in the region B described above can be thinned to a predetermined thickness even after re-stretching after heating to a second molding temperature equal to or higher than the first molding temperature, and the balloon body portion and the taper portion Therefore, it is possible to form a balloon catheter for dilatation with improved lesion pathability.
Preferably, after re-stretching both sides of the parison in the direction of arrow C, the mold 2 is heated to a second molding temperature not lower than the first molding temperature and not higher than the primary transition temperature.

At the time of re-stretching, since the balloon main body portion has already expanded and has a balloon shape with a predetermined thickness, it is only necessary to heat only the vicinity of the tapered portion and the connecting portion. This temperature control can be easily achieved by dividing the heating means 3 in advance into the balloon part heating means 3B and the end part heating means 3A, 3A so that each can be controlled.
In order to stabilize the balloon shape, after heating for a predetermined time at the second molding temperature, the mold is cooled to the second transition temperature or lower to obtain the catheter balloon 1 shown in FIG. By preparing a mold that matches the size of the balloon to be manufactured, balloons of various sizes can be manufactured. For example, the main body balloon diameter when expanded is 1.0 to 30 mm, and the length is 3.0 to 100 mm ones can be manufactured.

As described above, according to the present invention, after the primary molding into a balloon shape having a balloon portion, a taper portion, and a small-diameter connection portion, the primary molding temperature is not higher than the primary transition temperature without changing the mold. Since the secondary molding is performed by thinning the connecting portion by the step of heating to the second molding temperature and the step of re-stretching both sides of the parison, the balloon connecting portion and the tapered portion are thinned, and the lesion A balloon for catheter that can be used for an expansion balloon catheter with improved part-passability and a method for manufacturing the same can be obtained.
Furthermore, since it is a simple manufacturing method in which the mold is not exchanged, an exchange operation for transferring to the mold is unnecessary, and the balloon molding process is facilitated.

It is sectional drawing which shows an example of the balloon for catheters which concerns on this invention. It is sectional drawing which shows an example of the metal mold | die for balloon molding. It is sectional drawing of the parison after extrusion molding. It is sectional drawing of the preparation parison which has an unstretched part. It is sectional drawing which shows the place which shape | molded the balloon within a metal mold | die. The manufacturing process of the balloon for catheters which concerns on this invention is shown, (a) is sectional drawing which shows the place which mounted | wore the preparation parison to the metal mold | die, (b) performed the primary shaping | molding by expansion | swelling and primary extension. It is sectional drawing which shows a place, (c) is sectional drawing which shows the place which re-stretched and performed secondary shaping | molding.

Explanation of symbols

1 Balloon for catheter 1A Thin-walled tubular parison (preliminary product)
1B Preparatory parison 1C Primary molding parison 1D Secondary molding parison 2 Mold 3 Heating means

Claims (5)

A preformed tubular parison is attached to a mold having a balloon part mold with a predetermined inner diameter, a taper part mold, and small-diameter hole molds at both ends, and heated and pressurized to expand, and the balloon part and both sides of the balloon part A method for producing a balloon for a catheter having a small-diameter connecting portion extending through a tapered portion,
Stretching both sides of the tubular parison at a predetermined ratio, and forming a preparation parison in a state in which an unstretched portion having a predetermined width is left in the central portion,
The prepared parison is mounted in the mold, heated to a first molding temperature not lower than the secondary transition temperature and lower than the primary transition temperature, and a pressurized fluid is allowed to flow into the prepared parison and primary stretching is performed. A step of primary forming into a balloon shape having a balloon portion, a tapered portion, and a small-diameter connection portion that match the inner surface shape of the mold,
After the primary molding, in a state where the internal pressure was maintained in the preparation parison, the front Kikin type, heated to the first molded at a temperature or more of the following first order transition temperature second molding temperature, re-stretching the sides of the parison two The next molding step,
A method for producing a balloon for a catheter characterized by the above. The method for producing a balloon for a catheter according to claim 1, wherein the width of the unstretched portion remaining in the central portion is 0.3 to 0.7 times the length of the balloon portion. 3. The catheter according to claim 1, wherein, after the primary molding, the connection portion and the tapered portion are heated to a third molding temperature not lower than the first molding temperature and not higher than the primary transition temperature. Balloon manufacturing method. The method for manufacturing a catheter balloon according to any one of claims 1 to 3, wherein after the primary molding, the balloon portion is cooled and then heated to the second molding temperature. A catheter balloon manufactured by the method for manufacturing a catheter balloon according to any one of claims 1 to 4, and having a balloon portion and a small-diameter connection portion extending on both sides of the balloon portion via a tapered portion. The catheter balloon is characterized in that the thickness of the tapered portion and the connecting portion is as thin as the thickness of the balloon portion.

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