JP2001029448A - Balloon for balloon catheter and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon for a balloon catheter efficiently prepared from a polyolefinic resin polymerized by use of a metallocene catalyst. SOLUTION: An extruded tube made of a polyethylenic resin polymerized by use of a metallocene catalyst is irradiated with 40-100 Mrads of electron rays to form a crosslinked tube. Next, the crosslinked tube is exerted with a pressure of 15 kgf/cm2 (first blow pressure) for thirty seconds while being elongated vertically by 170% in a range of about 50 deg.C lower than the melting point of the polyethylene resin; then a pressure of 3 kgf/cm2 (second blow pressure) is maintained for one second and a balloon for a balloon catheter is blow molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a balloon for a balloon catheter having high strength, and more particularly to a balloon for a balloon catheter made of a polyolefin resin polymerized by using a metallocene catalyst.

[0002]

2. Description of the Related Art A so-called PTCA (percutaneous transluminal coronary artery dilatation) catheter, which is easily treated and recovered by a balloon catheter, is frequently used for diseases caused by stenosis of blood vessels.

[0003] The balloon catheter for PTCA is
In order to facilitate insertion into and removal from the body cavity such as blood vessels, the material of the balloon must have a certain shape when wound around a catheter tube, and have a certain shape retention during decompression. is necessary.

Polyolefins such as polyethylene or copolymers of ethylene and other α-olefins are known as materials for balloons satisfying such required performances (for example, Japanese Patent Application Laid-Open No. 8-196620). . In recent years, a balloon catheter using polyolefin polymerized using a metallocene catalyst has been reported, and is considered to exhibit excellent performance such as pressure resistance (for example, Japanese Patent Application Laid-Open No. 10-3).
No. 3658).

[0005] The present applicant has previously reported a balloon catheter using polyolefin polymerized using a metallocene catalyst (Japanese Patent Application Laid-Open No. 10-295801). According to this, the use of polyolefin polymerized using a metallocene catalyst as the material of the balloon portion is superior in flexibility and moldability compared to the case of using polyethylene polymerized using a conventional Ziegler-Natta catalyst. It was found that a balloon catheter was obtained.

[0006] However, as a result of further study, although a balloon prepared from polyolefin polymerized using a metallocene catalyst shows excellent flexibility and high breaking strength, the balloon is prepared by blow molding with a blow molding machine. Since the success rate in this case is low, it is difficult to perform stable blow molding, and it is also difficult to improve productivity.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a balloon for a balloon catheter which is efficiently prepared from polyolefin polymerized using a metallocene catalyst. Another object of the present invention is to provide a method for producing a polyolefin balloon polymerized using a metallocene catalyst. A further object of the present invention is to provide a PTCA catheter having a polyolefin balloon polymerized using a metallocene catalyst.

Accordingly, the present inventors have conducted intensive studies and as a result,
When preparing a balloon by blow molding using a polyethylene tube polymerized using a metallocene catalyst,
The polyethylene tube was previously irradiated with an electron beam under the conditions of 60 Mrad, which is about 4 times the amount of electron beam irradiation as compared with the normal conditions, to prepare a crosslinked tube. The success rate of blow molding was 10%. I found that it improved
Based on this finding, the present invention has been completed.

[0009]

According to the present invention, the following (1), (2) and (3) are provided. (1) A tube made of a polyolefin-based resin polymerized by using a metallocene catalyst is charged with an electron beam irradiation amount of 40 to 10.
A balloon for a balloon catheter, which is blow-molded using a cross-linking tube cross-linked by irradiation with an electron beam under 0 Mrad conditions.

(2) a step of preparing a cross-linked tube by cross-linking a tube made of a polyolefin-based resin polymerized using a metallocene catalyst under the conditions of an electron beam irradiation amount of 40 to 100 Mrad; A primary blow pressure is applied to the cross-linked tube at a temperature lower by at least 10 ° C. than the melting point, and then a secondary blow pressure, which is a pressure lower than the primary blow pressure, is applied to the cross-linked tube to cause the balloon to And a step of preparing.
4. The method for producing a balloon for a balloon catheter described in 1. above.

(3) an outer tube in which at least one balloon expansion lumen is formed along the longitudinal direction;
A proximal end portion of a balloon portion is joined to a distal end portion of the outer tube, and a balloon portion communicating with the balloon inflation lumen and an interior thereof is formed to form a sealed inflation space inside the balloon portion. A distal end of the balloon portion is joined to a distal end of the inner tube, and has an inner tube extending axially inside the balloon portion and inside the balloon expansion lumen of the outer tube. Then, the balloon portion is a tube made of a polyolefin resin polymerized using a metallocene catalyst, and the electron beam irradiation amount is 40 to 100.
A balloon catheter which is blow-molded using a cross-linked tube cross-linked by irradiation with an electron beam under Mrad conditions.

In the present invention, it is preferable to use an ethylene / α-olefin copolymer produced by a polymerization reaction using a metallocene catalyst as the material of the balloon for the balloon catheter.

In the present invention, when the balloon is blow-molded by a blow molding method, an electron beam is previously irradiated to a tube made of a polyolefin resin produced by a polymerization reaction using a metallocene catalyst under a condition of 50 M to 70 rad. Then, it is preferable that the tube is crosslinked with an electron beam to form a crosslinked tube. Further, it is preferable to heat-treat the crosslinked tube at least at 90 ° C.

In the present invention, when the crosslinked tube is blow-molded by a blow molding method, a primary blow pressure of 15 to 25 kgf / cm ^{2 is} applied to the mold, and at least one second before opening the mold, It is preferable to apply a secondary blow pressure of 5 to 8 kgf / cm ² .

The balloon for a balloon catheter of the present invention can be applied to any balloon catheter of the over-the-wire type or the monorail type. In the over-the-wire balloon catheter, a guide wire lumen is formed over the entire length of the catheter tube, a guide wire is inserted through the lumen, and the balloon is moved along the guide wire to the stenosis. (See, for example,
-26537, JP-A-8-38618, JP-A-9
No. 239035).

On the other hand, a monorail type balloon catheter has an opening formed in the middle of a catheter tube.
Through the guide wire insertion lumen from the opening,
It leads to the distal end of the balloon. Therefore, in this type of balloon catheter, the length of the guide wire extending outside the body for replacement of the balloon catheter is:
The length may be slightly longer than the length corresponding to the length from the opening to the balloon distal end, and can be shorter than that of the over-the-wire type. For this reason, it is said that the operability is excellent (for example, see JP-A-63-2630).
88167, JP-A-2-307479, etc.).

[0017]

When the balloon used in the balloon catheter of the present invention is formed by blow molding, it can be blow molded at a high success rate, and the productivity of the balloon catheter can be improved.

Since the balloon used in the balloon catheter of the present invention is prepared from a polyolefin resin polymerized using a metallocene catalyst, it is compared with a conventional case using polyethylene polymerized using a Ziegler-Natta catalyst. Thus, a balloon catheter having excellent flexibility and moldability can be obtained.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The balloon for a balloon catheter of the present invention is prepared using a polyolefin resin produced by a polymerization reaction using a metallocene catalyst. The polyolefin-based resin is produced by using olefin having 2 to 40 carbon atoms as a monomer and performing a polymerization reaction using a metallocene catalyst, and its density (JIS K-7112) is usually 0.1. 950g
/ Cm ³ or less, preferably 0.850 to 0.9.
40 g / cm ³ , more preferably 0.880 to 0.9
30 g / cm ³ . If the density is too low, inconveniences such as blocking due to stickiness of the balloon surface tend to occur, and if the density is too high, transparency is undesirably reduced.

A metallocene catalyst (also called a Kaminski catalyst or a single-site catalyst) is composed of a metallocene compound having a structure in which a transition metal is sandwiched between π-electron unsaturated compounds, and is combined with a co-catalyst such as methylaluminoxane or an organoaluminum compound. Used.

Examples of the metallocene compound include a transition metal of group IVB such as zirconium, titanium, and hafnium, a (substituted) cyclopentadienyl group, a (substituted) indenyl group, a (substituted) tetrahydroindenyl group, a (substituted)
One or two fluorenyl groups are bonded, or two of these groups are covalently cross-linked to form a bond. In addition, a hydrogen atom, an oxygen atom, a halogen atom, an alkyl group, an alkoxy group , Aryl group, acetylacetonate group, carbonyl group, nitrogen molecule, oxygen molecule,
Examples thereof include those having a ligand such as a Lewis base, a substituent containing a silicon atom, and an unsaturated hydrocarbon.

The cocatalyst is an ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, a compound which reacts with a metallocene compound to form a stable ion to form a polymerization active species; For example, tetrakis (pentafluorophenyl) boron or the like can be used.

The monomers of olefin for obtaining a polyolefin resin by a polymerization reaction using a metallocene catalyst include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene,
4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene and the like.
These monomers can be used alone or in combination of two or more.

As the polyolefin resin, polyethylene and ethylene / α-olefin copolymer are preferable from the viewpoint of various properties as a balloon, and ethylene / α-olefin copolymer is preferable.
Olefin copolymers are particularly preferred. The ethylene / α-olefin copolymer can be obtained by copolymerizing ethylene and α-olefin using a metallocene catalyst. As the comonomer, α having 4 to 40 carbon atoms
The use of olefins is preferred.

As the α-olefin, for example, 1
-Butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene and the like. Among these, the number of carbon atoms is 4 to
12 α-olefins are preferred and have 4 to 1 carbon atoms.
An α-olefin of 0 is more preferred. The copolymerization ratio of the α-olefin is usually 2 to 50% by weight, preferably 5 to 4% by weight.
0 wt%, more preferably 10 to 30 wt%.

The melt flow rate (MFR; JIS K-72) of a polyolefin resin such as an ethylene / α-olefin copolymer polymerized using the metallocene catalyst.
10) is usually 0.1 to 30.0 g / 10 min, preferably 1.0 to 20.0 g / 10 min, more preferably 1.0 to 30.0 g / 10 min.
１５15.0 g / 10 min, most preferably 1.5-15.
0 g / 10 minutes. If the MFR is too small, it is difficult to obtain a sufficient strength, and if the MFR is too large, the moldability decreases.

The polyolefin resin polymerized using a metallocene catalyst uses a metallocene catalyst having a uniform active site, so that not only has a narrow molecular weight distribution, but also a copolymer such as an ethylene / α-olefin copolymer. in case of,
When the α-olefin as a comonomer uniformly enters the main chain of ethylene, the composition distribution becomes narrow. Therefore, there are few components of low molecular weight and low density, and there are few components extracted with an organic solvent.

Many types of polyolefin resins such as ethylene / α-olefin copolymers using a metallocene catalyst have already been manufactured and sold, and thus commercially available products may be used.

In order to obtain a balloon having excellent moldability and various properties when molded into a balloon,
Among polyolefin resins polymerized using a metallocene catalyst, polyethylene resins such as polyethylene and ethylene / α-olefin copolymer are preferable, and ethylene / α-olefin copolymer is more preferable.

In the present invention, as the polymer material for forming the balloon, a polyolefin resin polymerized by using a metallocene catalyst, particularly preferably the above-mentioned specific ethylene-α-
Although the olefin copolymer can be used alone,
Various additives can be blended within a range that does not impair the object of the present invention. As additives, for example, several kinds of antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, metal deactivators, pigments, dyes, crystal nucleating agents and the like can be added as required. In this case, depending on the required properties, the amount of addition is usually 20 parts by weight or less, preferably 5 parts by weight or less based on 100 parts by weight of the polyolefin resin.

A method for manufacturing the balloon for a balloon catheter of the present invention will be described. First, a blow-molding original tube having dimensions designed in advance is formed using a polyolefin-based resin polymerized using a metallocene catalyst. The molding can be performed by, for example, an extrusion molding method, and the die temperature at the time of extrusion is, for example, 200 to 300 ° C. The extruded tube immediately after discharge from the die is, for example, a water tank (20
３０30 ° C.) for cooling.

Next, the extruded tube is irradiated with an electron beam, and a cross-linked tube made of polyolefin resin (hereinafter, referred to as “tube”).
Write "Parison". ) Is prepared. The irradiation amount of the electron beam is, for example, 40 to 100 Mrad, preferably 50 to 7 Mrad.
0 Mrad. In the present invention, the extruded tube is cross-linked with an electron beam within the above-mentioned range of the irradiation amount of the electron beam, and then the cross-linked tube is blow-molded to form a balloon at a success rate of 70% or more. be able to. If the irradiation amount of the electron beam is excessively small, the success rate when forming the balloon by blow molding is 60%.
% Is difficult to achieve. Further, the strength of the balloon is undesirably reduced. If the irradiation amount of the electron beam is excessively large, the flexibility of the balloon formed by blow molding is reduced, which is not preferable.

The cross-linked tube is then, for example, 90
The heat treatment is performed at about 110 ° C. for about 30 minutes to several hours. By this heat treatment step, molding distortion due to extrusion molding is eliminated, and the success rate of blow molding can be further increased.

The parison prepared through the above steps is shaped into a balloon by blow molding, for example, through the following steps. First, as shown in FIG. 7A, the upper and lower sides of the parison are fixed. The upper chuck seals completely to prevent pressure leakage, and the lower chuck does not collapse the lumen so that blow pressure is applied.

Next, the parison is blow-molded at a temperature lower than the melting point of the polyolefin resin polymerized using the metallocene catalyst, which is a material of the parison. The temperature is, for example, lower than the melting point of the polyolefin-based resin by 10 ° C. or more, preferably 20 ° C. or more, and more preferably 30 ° C. to 60 ° C. If the temperature is too high, blow molding becomes easier, but the breaking strength of the balloon decreases. If the temperature is excessively low, a high blow pressure is required to shape the balloon, which is not preferable. Also,
Balloons blow-molded on an excessively low temperature side are not preferred because of extreme shrinkage.

The blow molding is specifically performed by the following steps. The parison fixed up and down is, for example, 50 to
90 ° C., preferably in the range of 75-85 ° C., 30-18
After heating for 0 minutes, preferably 100-150 minutes,
The film is stretched in the vertical direction by about 150 to 200%. Next, at the same time as the parison was stretched, the mold was divided into two pieces from both sides (the parison was heated to the same temperature as the parison).
Is closed so as to sandwich the parison, and then the first blow pressure is applied for 10 to 60 seconds, preferably 20 to 40 seconds.
Hold for seconds.

Next, the pressure is maintained at a blow pressure lower than the first blow pressure (hereinafter referred to as "second blow pressure") for 0.5 to 3 seconds, and then the mold is opened.
If the mold is opened with the first blow pressure, the formed balloon will burst, so it is necessary to reduce the blow pressure to the second blow pressure immediately before the mold is opened. In the case of the present embodiment, the second blow pressure is equal to the first blow pressure.
This is performed at a pressure of one half or less, preferably one third or less of the blow pressure.

The gas introduced into the parison is not particularly limited, but for example, nitrogen gas or the like can be used. The first blow pressure for inflating the parison is
For example, 10 to 30 kgf / cm ² , preferably 15 to
It is 25 kgf / cm ² . The second blow pressure is, for example, 3 to 10 kgf / cm ² , preferably 5 to 8 kg.
f / cm ² .

By the blow molding described above, the balloon is
For example, as shown in FIG.
And a portion 7f for joining with the balloon catheter.

The outer diameter of the balloon formed by blow molding is 1 atm or 6 atm by a laser outer diameter measuring device.
The outer diameter when applying a pressure of atm is measured. The thickness of the balloon is measured with a micro gauge.

The balloon formed by blow molding
The effective stretching ratio (cross-sectional area of cross-linked tube / cross-sectional area of balloon) from the cross-linked tube to the balloon needs to be less than 500%, preferably 350% or less. An excessively large effective stretching ratio is not preferable because the breaking strength of the balloon is extremely reduced.

The balloon for a balloon catheter of the present invention is composed of a cylindrical film having both ends reduced in diameter, and the thickness thereof is not particularly limited, but is 15 to 300 μm, preferably 30 to 150 μm. The balloon portion 4 is not particularly limited as long as it is cylindrical, and may have a cylindrical or polygonal cylindrical shape. The outer diameter of the balloon portion 4 when expanded is usually 1.5
It is about 10.0 mm, preferably 3-7 mm.
The length of the balloon portion 4 in the axial direction is not particularly limited.
It is 5 to 50 mm, preferably 20 to 40 mm. The balloon portion 4 before being expanded is folded and wound around the inner tube 12, and has an outer diameter as small as possible.

Next, an embodiment of a balloon catheter using the balloon for a balloon catheter of the present invention will be described with reference to the drawings.

FIG. 1A is an overall configuration diagram of a balloon catheter using the balloon for a balloon catheter of the present invention, FIG. 1B is a cross-sectional view taken along the line IB-IB shown in FIG. 1C is a cross-sectional view taken along the line IC-IC shown in FIG. 1A, and FIG. 1D is an ID-ID shown in FIG.
1E is a cross-sectional view taken along a line, and FIG.
FIG. 3 shows a cross-sectional view along the IE line. FIG. 2 is a longitudinal sectional view of a main part of the balloon catheter shown in FIG.

The balloon catheter 2 according to the present embodiment shown in FIG. 1 includes, for example, percutaneous coronary angioplasty (PTCA),
It is used in methods such as dilation of blood vessels such as limbs, dilation of the upper ureter, and renal vasodilation, and is used to dilate stenosis formed in blood vessels or other body cavities. In the following description, the balloon catheter 2 of the present embodiment is referred to as PTC.
A case where A is used will be described as an example.

The dilatation balloon catheter 2 of the present embodiment
Is a so-called monorail type balloon catheter, which has a balloon portion 4, an outer tube 6 as a catheter tube, and a connector 8. The outer tube 6
The first outer tube member 6a is relatively flexible, and the second outer tube member 6b is relatively rigid and is joined to the first outer tube member 6a at the joint 9.

In this embodiment, the proximal end opening of the inner tube is opened to the outside through the tube wall located in the longitudinal direction of the first outer tube member 6a, and the proximal end opening of the inner tube is opened. By adopting a structure in which the portion and the tube wall of the first outer tube member 6a are heat-sealed in an airtight manner, only the distal end of the balloon catheter has a so-called coaxial catheter tube structure. is there.

In the present embodiment, as shown in FIG. 1C, the outer cross-sectional shape of the second outer tube member 6b has an elliptical shape elongated in the Y-axis direction. The ratio (xm) between the maximum cross-sectional width xm of the catheter tube in the X-axis direction perpendicular to the Y-axis and the maximum cross-sectional width ym in the Y-axis direction
/ Ym) is in the range of 0.8 to 0.1, and the third lumen 24 having a semicircular cross section and the fourth lumen 26 having a circular cross section
Are formed separately along the Y-axis direction.

The semicircular cross-sectional area of the third lumen 24 is
It is sufficient that the cross-sectional area is sufficient to allow the balloon expansion pressure fluid to flow, and is not particularly limited.
08 to 0.20 mm ² . Also, the fourth lumen 2
The circular cross-sectional area of No. ⁶ is not particularly limited as long as it is a sufficient area for inserting the reinforcing rod 28 therein, but is preferably 0.05 to 0.5 mm ² , and more preferably 0.1 to 0.5 mm ² . 0.2 mm ² .

In this embodiment, the second outer tube member 6b
, The maximum cross-sectional width ym in the Y-axis direction is 0.6
It is preferably about 1.2 mm. Second outer tube member 6b
Is joined to the proximal end of the first outer tube member 6a having a circular cross section, so that the cross-sectional shape near the joint 9 is the same as the circular cross-sectional shape with the first outer tube member 6a. In order to make them coincide with each other, the cross-sectional shape gradually changes from the deformed cross section to the circular cross section toward the joint 9.

The third lumen 24 formed along the longitudinal direction of the second outer tube member 6b communicates with the first lumen 10 of the first outer tube member 6a, and through these, the space for expansion of the balloon portion 4. To take fluid in and out. The fourth lumen 26 of the second outer tube 6b is a lumen for inserting the reinforcing rod 28, and communicates with the first lumen 10 of the first outer tube member 6a. It is closed at 8 and does not allow fluid to enter or exit. The proximal end of the second outer tube member 6c is connected to the connector 8, and a port is formed to communicate with the third lumen 24 of the second outer tube 6b. The port is a part that allows the pressure fluid to enter and exit, and does not communicate with the fourth lumen 26.

The reinforcing rod 28 shown in FIGS. 1B, 1C and 1F is inserted into the fourth lumen 26 of the second outer tube member 6b over its entire length, and its distal end is , Over the joint 9 with the first outer tube member 6a and protruding into the first lumen 10 of the first outer tube member 6a. The proximal end of the reinforcing rod 28 is circular in cross section, tapered from the middle toward the distal end, and further has a flat cross section at the distal end.
Its cross-sectional shape is gradually changing. The distal end of the reinforcing rod 28 having a flat cross section slightly crosses the proximal end opening 22 of the inner tube 12 slightly (preferably about 1 to 10 cm) as shown in FIGS. 1 (D) and 2. At the position, it is joined to the inner wall of the first outer tube member 6a by means such as heat fusion or adhesion.

The maximum outer diameter of the reinforcing rod 28 is the second outer diameter.
It is determined so that it can be inserted into the fourth lumen 26 of the outer tube member 6b, and is not particularly limited.
０．６0.6 mm.

As shown in FIG. 2, the first outer tube member 6
The proximal end 5 of the balloon portion 4 is joined to the outer periphery of the distal end of the balloon portion 4 by means such as heat fusion or adhesion, and the first lumen 10 of the first outer tube member 6a is It is designed to communicate with the internal expansion space. Balloon part 4
Is joined to the outer periphery of the distal end of the inner tube 14 by means such as heat fusion or adhesion, and the space for internal expansion of the balloon portion 4 is other than the first lumen 10. , Sealed to the outside. First outer tube member 6
The first lumen 10a is a passage for sending fluid into the internal expansion space of the balloon portion 4 to expand the balloon portion 4 or to extract fluid from the expansion space of the balloon portion 4 and to contract the balloon portion 4. is there.

As shown in FIG. 2, the inner tube 12 extends coaxially and axially in the expansion space of the balloon portion 4 and the inside of the distal end side first lumen 10 of the first outer tube member 6a. It has a catheter tube structure. Inner tube 12 located inside balloon portion 4
A contrast ring 15 is attached to the outer periphery of the body, and when the balloon catheter 2 is inserted into a living body, the position of the contrast ring 15 can be contrasted with X-rays or the like from outside the living body. Examples of the material of the contrast ring 15 include metals such as gold, platinum, and tungsten.

A second lumen 14 is formed inside the inner tube 12, and its distal end opening 20 opens at the distal end 7 of the balloon portion 4. The proximal end opening 22 of the inner tube 12 is opened to the outside through a through-hole 21 in the tube wall located in the longitudinal direction of the first outer tube member 6a. Proximal end opening 2 of inner tube 12
The peripheral edge of 2 and the peripheral edge of the through hole 21 in the tube wall of the first outer tube member 6a are hermetically joined by a heat fusion method described later. The shape of the proximal end opening 22 of the inner tube 12 is not particularly limited, and may take various shapes such as a circle and an ellipse. In the present embodiment, as shown in FIG. It is an elliptical shape with the part cut diagonally. The second lumen 14 of the inner tube 12 is a guidewire insertion lumen through which a guidewire 42 shown in FIG. 2 for guiding the balloon catheter 2 into a body cavity is inserted.

The inner tube 12 is connected to the first outer tube member 6.
The first outer tube member 6a may be made of a synthetic resin that is harder than the first outer tube member 6a. The position where the proximal end opening 22 of the inner tube 12 opens outside the first outer tube member 6a is preferably a position of a length L1 from the distal end of the first outer tube member 6a, and the length L1 Is preferably 150 to 350
mm, more preferably 200 to 300 mm.

The outer diameter of the first outer tube member 6a is not particularly limited, but is preferably 0.5 to 5 mm, and more preferably 0.5 to 1 mm. First outer tube member 6a
Is not particularly limited, but preferably 0.05 to
It is 0.5 mm, more preferably 0.1 to 0.2 mm.

The outer diameter of the inner tube 12 is determined so as to form a gap between the inner tube 12 and the first outer tube member 6a, and is not particularly limited, but is preferably 0.3 to 3 mm, and more preferably 0.3 to 3 mm. 0.8 mm. Inner tube 12
Is not particularly limited as long as it can penetrate the guide wire 42, and is, for example, 0.15 to 1.0 mm, and preferably 0.25 to 0.6 mm.

In this embodiment, in order to reinforce the strength of the first outer tube member 6a from the vicinity of the opening 22 to the proximal end side, as shown in FIG.
It may be disposed inside the first outer tube member 6a from the vicinity to the proximal end side. The proximal end of the reinforcing rod 28 has a circular cross-section, tapers from the middle toward the distal end, and has a cross-sectional shape at the distal end such that the reinforcing rod 28 has a flat cross-sectional shape. It is changing gradually. The distal end of the reinforcing rod 28, which has a flat cross-section, slightly (preferably 1) with the proximal end opening 22 of the inner tube 12, as shown in FIG.
(About 10 cm) at a position over the inner wall of the first outer tube member 6a by means of heat fusion or adhesion.

The reinforcing rod 28 is made of stainless steel,
It is made of a metal material such as copper, copper alloy, titanium, and titanium alloy, or a synthetic resin such as polyimide, polyamide, and polyethylene terephthalate. The maximum outer diameter of the reinforcing rod 28 is determined so as not to block the lumen 10 of the first outer tube member 6a, and is not particularly limited, but is preferably 0.3 to 0.6 mm.

The first outer tube member 6a may be made of, for example, the same material as the balloon portion 4, but is preferably made of a material having flexibility. For example, polyethylene, polyethylene terephthalate, polypropylene,
Ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, polytetrafluoroethylene resin , Ethylene tetrafluoride-hexafluoropropylene copolymer resin, ethylene tetrafluoride-
Perfluoroalkyl vinyl ether copolymer resin, ethylene trifluoride resin, ethylene tetrafluoroethylene-ethylene copolymer resin, vinylidene fluoride resin, polyvinyl fluoride resin, silicone rubber, natural rubber, and the like. Among them, polyethylene, polyamide and polyimide are preferred. The hardness of the first outer tube member 6a is J
Those having an IS hardness of about 50A to 90A can be used.

The second outer tube member 6b is made of the same material as the first outer tube member. As the hardness of the second outer tube member 6b, one having a JIS hardness of about 50D to 75D can be used.

In the present embodiment, the outer tube 6 composed of the first outer tube member 6a and the second outer tube member
Is preferably coated with a coating material made of a hydrophilic polymer substance having lubricity in a wet state.

[0065]

As described above, according to the present invention, a balloon for a balloon catheter using a polyolefin-based resin polymerized using a metallocene catalyst can be efficiently produced.

In the balloon catheter using the balloon for a balloon catheter of the present invention, the outer tube is made of a relatively flexible distal end side first outer tube member and a comparatively flexible first outer tube member joined to the first outer tube. In the case where the distal end side of the catheter tube is made of the second outer tube member made of the proximal end side having high target rigidity, the distal end side of the catheter tube becomes flexible, and the insertion characteristics in a body cavity such as a meandering blood vessel are further improved.

[Brief description of the drawings]

FIG. 1A is an overall configuration diagram of an embodiment of a balloon catheter using a balloon for a balloon catheter of the present invention, and FIG. 1B is an IB-IB shown in FIG. 1A.
FIG. 1C is a cross-sectional view along the line, and FIG.
1D is a cross-sectional view taken along the line IC, and FIG.
1 (E) is a cross-sectional view taken along a line IE-IE shown in FIG. 1 (A), and FIG. 1 (F) is a cross-sectional view of a reinforcing rod inserted into a catheter tube of a balloon catheter. It is a side view.

FIG. 2 is a longitudinal sectional view of a main part of the balloon catheter shown in FIG. 1 (A).

FIG. 3A is a cross-sectional view of a main part when a parison is fixed to a blow molding machine in the method for manufacturing a balloon for a balloon catheter of the present invention, and FIG. 3B is obtained by blow molding. FIG. 2 is a perspective view of a balloon.

[Explanation of symbols]

 2 balloon balloon 4 balloon portion 6 outer tube 6a first outer tube member 6b second outer tube member 8 connector 10 first lumen 12 inner tube 14 second lumen 20 distal end opening 21 ... Through-hole 22 ... Proximal end opening 24 ... Third lumen 26 ... Fourth lumen 28 ... Reinforcing rod 28a ... Reinforcing member 54, 56, 60 ... Mandrel 7a ... Parison 7b ... Upper chuck 7c ... Lower chuck 7d ... Heating Heater 7e: Balloon body 7f: Joint with balloon catheter body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 22:00

Claims (3)

[Claims] 1. A tube made of a polyolefin resin polymerized using a metallocene catalyst is exposed to an electron beam at a dose of 4
A balloon for a balloon catheter, which is blow-molded using a cross-linked tube cross-linked by performing electron beam irradiation under a condition of 0 to 100 Mrad. 2. A tube made of a polyolefin resin polymerized using a metallocene catalyst is charged with an electron beam irradiation amount of 4%.
A step of preparing a cross-linked tube by electron beam cross-linking under the conditions of 0 to 100 Mrad, and applying a primary blow pressure to the cross-linked tube at a temperature lower by at least 10 ° C. than the melting point of the polyolefin-based resin; 2. The method for producing a balloon for a balloon catheter according to claim 1, further comprising: applying a secondary blow pressure, which is lower than the primary blow pressure, to the cross-linking tube to prepare the balloon. 3. An outer tube having at least one balloon inflation lumen formed along a longitudinal direction thereof, and a proximal end of a balloon portion joined to a distal end of the outer tube. A balloon portion that communicates with the lumen, and a distal end portion of the balloon portion is joined to a distal end portion of the inner tube so as to form a sealed expansion space inside the balloon portion; And an inner tube extending in the axial direction inside the balloon-expanding lumen of the outer tube, wherein the balloon portion is a tube made of a polyolefin-based resin polymerized using a metallocene catalyst. A balloon catheter, which is blow-molded using a cross-linked tube cross-linked by irradiation with an electron beam under the conditions of an irradiation amount of 40 to 100 Mrad.