WO2001005444A1

WO2001005444A1 - Balloon for balloon catheter and production method thereof

Info

Publication number: WO2001005444A1
Application number: PCT/JP2000/004729
Authority: WO
Inventors: Masaru Uchiyama; Shinichi Miyata
Original assignee: Zeon Corporation
Priority date: 1999-07-19
Filing date: 2000-07-14
Publication date: 2001-01-25
Also published as: JP2001029449A

Abstract

A balloon for a balloon catheter, which is formed by blow-molding a polyethylene resin tube, obtained through the irradiation of electron beams of 5 to 40 Mrad followed by electron cross-linking, at a primary blow pressure of 15 to 25 kgf/cm2 and at a secondary blow pressure of 5 to 8 kgf/cm2, the balloon having a film thickness of 10 to 40 νm and a break strength of 800 to 2000 kgf/cm2. A mono-rail type balloon catheter for percutaneous intravascular coronary artery plastic operation, which has this balloon for the balloon catheter, an outer tube consisting of a comparatively flexible first outer tube member and a comparatively rigid second outer tube member, and an inner tube passing through a tube wall positioned in the lengthwise middle of the first outer tube member and formed with a proximal-end opening on the outer side thereof.

Description

Specification

TECHNICAL FIELD The present invention relates to a balloon for a balloon catheter and a method for producing the balloon.

TECHNICAL FIELD The present invention relates to a balloon catheter having a thin and high-strength balloon, and in particular, percutaneous intravascular coronary angioplasty (Percutaneous Translumina 1 Coronary Angioplasty, hereinafter referred to as “b”, “PTCA”). The present invention relates to a balloon catheter suitable for use. Background art

For diseases caused by stenosis of blood vessels, the so-called PTCA catheter, which is easily treated and recovered with a balloon catheter, is frequently used.

In a PTCA catheter, for example, in the treatment of the coronary artery of the heart, a guiding catheter is first inserted to the entrance of the coronary artery, a guide wire is inserted beyond the stenosis, and a balloon catheter is pushed into the stenosis. Thus, the stenosis is expanded by expanding the balloon.

PTCA catheters are being used to take advantage of them to expand their application range, but their required characteristics are also becoming more sophisticated. For example, it is required to be able to treat peripheral coronary stenosis, to be easily inserted into a bent blood vessel, to have a strong dilatation pressure, and to be able to safely dilate a blood vessel. More specifically, there is a need for the ability to treat peripheral coronary artery stenosis using the PTCA force table. For this purpose, a balloon that is thinner and stronger than ever is required.

However, in the case of a polyethylene resin (for example, Japanese Patent Application Laid-Open No. 8-196620) which has been mainly used as a balloon material of a PTCA catheter, an electron beam is generally irradiated to reduce the gel fraction. A method of improving the stretching properties as a balloon material by improving the bursting pressure by cross-linking to about 0.9% is adopted.

In this case, since about 0.9% of the gel is formed in the cross-linked polyethylene resin, the balloon is inflated to about 300% and its thickness is reduced. The lower the strength of the balloon and the lower the pressure at which the balloon bursts, the lower the limit for obtaining a thin, high-strength balloon. Disclosure of the invention

An object of the present invention is to provide a thin and high-strength balloon for a balloon catheter suitable for PTCA use.

Another object of the present invention is to provide a method for producing the thin and high-strength polyolefin resin balloon.

A further object of the present invention is to provide a balloon catheter having the thin and high-strength polyolefin resin balloon.

Thus, the present inventors have conducted intensive studies and found that the polyethylene resin tube was cross-linked by irradiation with an electron beam so that a gel having a gel fraction of about 0.7% was formed. was blown with conditions at 80 ° C for a considerably lower temperature than the melting point of the polyethylene resin, it found that balloon stretching ratio is 600% and breaking strength is 1 1 00 kgfcm ² is obtained, on this finding Based on this, the present invention has been completed.

According to the present invention, the following (1), (2) and (3) are provided.

(1) A balloon formed by blow molding using a crosslinked tube made of a polyolefin resin, wherein the balloon has a film thickness of 10 to 40 m and a rupture strength of the balloon of 800 to 2000 kg.バル / cm ² , balloon for balloon catheter.

(2) a step of preparing a crosslinked tube having a gel content of 0.2 to 0.8% by electron beam cross-linking a tube made of polyolefin resin, and a temperature lower than the melting point of the polyolefin resin by 10 ° C or more. Then, a primary blow pressure is applied to the cross-linking tube, and then a secondary blow pressure, which is lower than the primary blow pressure, is applied to the cross-linking tube, whereby effective stretching from the cross-linking tube to the balloon is performed. Magnification 500 ~ 100

The method for producing a balloon for a balloon catheter according to the above (1), comprising a step of blow molding to prepare a balloon portion so that the balloon portion becomes 0%.

(3) At least one balloon expansion lumen is formed along the longitudinal direction An outer tube, a proximal end portion of a balloon portion joined to a distal end portion of the outer tube, a balloon portion communicating with the balloon expansion lumen, and an expansion portion sealed inside the balloon portion; The distal end of the balloon portion is joined to the distal end of the inner tube so as to form a space, and extends axially inside the balloon portion and inside the balloon expansion lumen of the outer tube. The balloon portion is a balloon formed by blow molding using a cross-linked tube made of a polyolefin resin, and the balloon has a film thickness of 10 to 40 μm. A balloon catheter, wherein the balloon has a breaking strength of 800 to 2000 kg kg / cm ² . In the method for producing a balloon for a balloon catheter of the present invention, a tube made of a polyolefin resin is irradiated with an electron beam of 5 to 4 OM rad, preferably 10 to 2 OM rad, and the tube is cross-linked with an electron beam. Thus, a crosslinked tube having a gel content of 0.2 to 0.7% is preferable. Further, the crosslinked tube is preferably heat-treated at least at 90 ° C.

In the method of manufacturing the balloon, when blow-molding the cross-linked tube, apply a primary opening pressure of 15 to 25 kg iZcm ² to the mold, and at least 1 second before opening the mold. preferably to create a balloon loaded with secondary blow pressure of 5 to 8 kgf Zc m ^2.

In the present invention, the thickness of the balloon for a balloon catheter made of a polyolefin resin is preferably 25 to 35 / m.

In the present invention, the balloon for a balloon catheter made of a polyolefin resin preferably has an effective stretching ratio from the crosslinked tube to the balloon of 500 to 700%. Further, the breaking strength of the balloon is preferably 1 000~2000 kgf Z cm ^2.

The balloon for a balloon catheter of the present invention can withstand high pressure for balloon inflation because the balloon has an extremely high breaking strength as compared with a balloon obtained by blow molding a polyethylene resin. For example, when used as a PTCA balloon catheter, the safety when dilating a vascular stenosis is extremely excellent.

In addition, the balloon for a balloon catheter of the present invention has an extremely thin film thickness. For example, when used as a balloon of a PTCA catheter, the diameter of the PTCA catheter can be reduced, so that peripheral coronary artery stenosis can be treated more than before. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is an overall configuration diagram of a balloon catheter according to an embodiment of the present invention.

FIG. IB is a cross-sectional view taken along the line IB-IB shown in FIG. 1A.

FIG. 1C is a cross-sectional view taken along line IC_IC shown in FIG. 1A.

FIG. ID is a cross-sectional view taken along the line ID_ID shown in FIG. 1A.

FIG. IE is a cross-sectional view taken along line IE—IE shown in FIG. 1A.

FIG.1F is a side view of the reinforcing pad inserted into the catheter tube of the balloon catheter.

FIG. 2A is a longitudinal sectional view of a main part of the balloon catheter shown in FIG. 1A. FIG. 3A is a cross-sectional view of a main part when a parison is fixed to a blow molding machine. FIG. 3B is a perspective view of the balloon obtained by blow molding. BEST MODE FOR CARRYING OUT THE INVENTION

The balloon for a balloon catheter of the present invention is prepared using a polyolefin resin. The polyolefin resin is produced by a polymerization reaction using an olefin having 2 to 40 carbon atoms as a monomer, and its density (JISK-7112) is usually 0.950 g / cm ³ or less. And preferably from 0.850 to 0.940 g / cm ³ , more preferably from 0.880 to 0.930 gZcm ³ . If the density is too low, problems such as blocking due to stickiness of the balloon surface are likely to occur, and if the density is too high, transparency is undesirably reduced.

Monoolefin monomers for obtaining polyolefin resin by polymerization reaction include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methylino-1-pentene, 4-methylene 1-Hexene, 4,4-dimethyl-11-pentene and the like. These monomers can be used alone or in combination of two or more. As the polyolefin resin, from the viewpoint of various properties as a balloon, polyethylene and an ethylene / _α -olefin copolymer are preferable, and an ethylene / α-olefin copolymer is particularly preferable. The ethylene .alpha.-olefin copolymer can be obtained by copolymerizing ethylene and _.alpha.- olefin by using a meta-mouth catalyst. As the comonomer, it is preferable to use α-olefin having 4 to 40 carbon atoms.

Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl_1-pentene, 4_methyl-1-hexene, 4, 4-dimethyl-11-pentene and the like. Among these, monoolefins having 4 to 12 carbon atoms are preferable, and monoolefins having 4 to 10 carbon atoms are more preferable. The copolymerization ratio of α-olefin is usually 2 to 50 weight. / ₀ , preferably 5-40 weight. / ₀ , more preferably 10 to 30% by weight.

Specific examples of the polyolefin resin include a polyethylene resin, a propylene resin, an ethylene-propylene copolymer resin, and a copolymer resin of ethylene and another α-olefin. Among them, polyethylene resin is preferable, and low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and the like are preferably used.

The melt flow rate (MFR; JISK-7210) of the polyolefin resin is usually 0 :! 0 to 30.0 gZl 0 min, preferably 1.0 to 20. O gZl O min, more preferably 1.0 to: 15 · O gZl O min, most preferably 1.5 to: 15.0 g / 10 minutes. If the MFR is too small, it is difficult to obtain sufficient strength, and if it is too large, the moldability will be reduced.

In the present invention, various additives can be blended with the polyolefin resin within a range that does not impair the object of the present invention. As the additives, for example, several kinds of antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, metal deactivators, pigments, dyes, and crystal nucleating agents can be added as necessary. 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.

The method for producing the balloon for a balloon catheter of the present invention will be described. First, the knot Using a crystalline polyolefin resin, mold the original tube for professional molding with pre-designed dimensions. The molding can be performed by, for example, an extrusion molding method. The die temperature during extrusion is, for example, 200 to 300 ° C. The extruded tube immediately after discharge from the die is cooled, for example, by passing it through a water tank (20 to 30 ° C).

Next, the extruded tube is irradiated with an electron beam to form a cross-linked tube made of polyolefin resin (hereinafter, referred to as “parison”). The irradiation amount of the electron beam is, for example, 5 to 40 Mrad, preferably 10 to 20 Mrad. Thereafter, the crosslinked tube is subjected to a heat treatment at, for example, about 90 to 110 ° C. for 30 minutes to several hours. This heat treatment step eliminates molding distortion due to extrusion.

The gel fraction of the tube crosslinked by the electron beam irradiation is 0.8% or less, and preferably 0.2 to 0.7. It is preferably about / ₀ . The gel fraction can be measured as the insoluble content of the crosslinked sample in heated xylene. Specifically, after heating 0.1 g of the crosslinked sample in 100 ml of xylene heated to 120 ° C for 6 hours, the soluble matter was filtered off, and the dry weight of the remaining crosslinked sample was measured. Then, calculate the ratio to the crosslinked sample before treatment.

The parison prepared through the above steps is shaped into a balloon by professional molding, for example, through the following steps. First, the upper and lower sides of the parison are fixed, as in FIG. 3A. The upper chuck seals completely so that pressure does not leak, and the lower chuck does not crush 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 that is the material of the parison. The temperature is, for example, at least 10 ° C. or more, preferably 30 ° C. or more lower than the melting point of the polyolefin resin, and more preferably 30 to 60 ° C. lower temperature. If the temperature is too high, blow molding becomes easier, but the breaking strength of the balloon decreases. On the other hand, if the temperature is excessively low, a very high blow pressure is required to shape the balloon, which is not preferable. Also, a balloon blow-molded on the low temperature side is not preferable because it extremely shrinks. Specifically, the professional molding is based on the following steps. In the present embodiment, the parison fixed at the top and bottom is heated, for example, in advance at about 50 to 90 ° C., preferably in the range of 75 to 85 ° C., for 30 to 180 minutes, preferably 100 to 150 minutes. After being done, 1 Stretched about 50-200%. Next, at the same time as the parison was stretched, the two halves of the mold (heated to the same extent as the parison) were closed so as to sandwich the parison, and then the first blow pressure was applied. And held for 10 to 60 seconds, preferably for about 20 to 40 seconds. Next, the pressure is maintained at a pressure of at least one-half or less, preferably one-third or less, of the first blow pressure (hereinafter, referred to as a “second pressure”) for 0.5 to 3 seconds. The mold can be opened.

The gas introduced into the parison is not particularly limited. For example, nitrogen gas or the like can be used. The first blow pressure for expanding the parison is, for example, 10 to 30 kgi / cm ² , preferably 15 to 25 kgf / cm ² . 2nd blow — the pressure is, for example, 3 ~ :! O kgfcm ² , preferably 5 to 8 kgf / cm ² .

By the above-mentioned pro-molding, the balloon is formed into a shape having a nozzle body portion 7e and a portion 7f for joining with the balloon catheter as shown in, for example, FIG. 3B. .

The outer diameter of the balloon formed by blow molding is measured by a laser

Measure the outer diameter when a pressure of 1 atm or 6 atm is applied. The thickness of the balloon is measured with a micro gauge.

The effective stretch ratio (cross-section tube cross-section area, Z-balloon cross-section area) of the balloon formed by the bubbling process from the crosslinked tube to the balloon is 400-1500%, preferably 500-10000. ° / ₀ is required. An excessively large effective stretching ratio is not preferable because the breaking strength of the balloon is extremely reduced. In the present invention, the extruded tube is irradiated with an electron beam under conditions of 5 to 4 OMrad to form a cross-linked tube made of polyethylene, whereby the effective stretching ratio is 400 to 1500%, and , the breaking strength of the balloon is 800 to 2000 kgf Zc m ^2, good Mashiku is 1 000: it is achieved 1 is 800 kgf Zc m ^2.

In the present invention, the thickness of the balloon formed by the blow molding is 5 to 40 μπι, preferably 25 to 35 μπι.

The rupture strength of the balloon was maintained at 37 ° C in water at a pressure of 15 psi on the balloon and held for 15 seconds, followed by an additional 15 psi and hold for 15 seconds. Repeat until the balloon ruptures, and measure the pressure at the time of rupture as the breaking strength.

Table 1 shows the breaking strength of the balloon blow-molded by the method described above. The irradiation strength of electron beam was adjusted to 4 OM rad and 6 OM rad, and the breaking strength of a balloon formed by blow molding using a gel having the same gel content as that of a conventional cross-linked tube was compared. Table 1 shows a comparative example. From the results in Table 1, it can be seen that the balloon for balloons of the present invention has a thin balloon thickness and significantly increased breaking strength at an effective stretching ratio of 500% or more.

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.

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

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

In the present embodiment, the proximal end opening of the inner tube penetrates a tube wall positioned halfway in the longitudinal direction of the first outer tube member 6a and opens to the outside, and the proximal end opening of the inner tube is formed. And the tube wall of the first outer tube member 6a is heat-sealed in a gas-tight manner, so that only the distal end of the balloon catheter has a so-called coaxial catheter tube structure. Things.

In the present embodiment, as shown in FIG. 1C, the cross-sectional outer shape of the second outer tube member 6b has an elongated elliptical shape in the Y-axis direction. The ratio (xmZym) between the maximum cross-sectional width xm of the catheter tube in the X-axis direction and the maximum cross-sectional width ym in the Y-axis direction (xmZym), which is in the range of 0.8 to 0.1, is the third lumen with a semicircular cross-section 24 and a 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 not particularly limited as long as it is a cross-sectional area sufficient for the flow of the balloon expansion pressure fluid, and is preferably 0.08 to 0.20 mm ² . The circular cross-sectional area of the fourth lumen 26 is not particularly limited as long as it is a sufficient area for inserting the reinforcing rod 28 therein, but is preferably in the range of 0.05 to 0.5 mm ² . , more preferably 0.5:! a ~ 0. 2mm ^2. In the present embodiment, in the cross section of the second outer tube member 6b, the maximum cross section width ym in the Y axis direction is preferably about 0.6 to 1.2 mm. Since the distal end of the second outer tube member 6b is joined to the proximal end of the first outer tube member 6a having a circular cross section, the cross-sectional shape near the joint 9 is the first outer tube member 6b. In order to match the circular cross-sectional shape with the tube member 6a, the cross-sectional shape gradually changes from the irregular cross-section to the circular cross-section toward the joint portion 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 passes through the balloon portion 4 The fluid is taken in and out of the expansion space. 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. The proximal end is closed at the connector 8 and no fluid enters or exits. Connector 8 has a second outer tube The proximal end of the valve member 6c is connected to form a port communicating 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. FI G. IB, FI G. 1C, and FI G. 1F is inserted into the fourth lumen 26 of the second outer tube member 6b over its entire length, and its distal end is The end portion of the first outer tube member 6a jumps out of the joint portion 9 with the first outer tube member 6a and protrudes into the first lumen 10 of the first outer tube member 6a. The proximal end of the reinforcing rod 28 has a circular cross-section, tapers from the middle toward the distal end, and has a gradually increasing cross-sectional shape at the distal end so as to have a flat cross-section. Has changed. The distal end of the stiffening rod 28 having a flat cross-section has a slight (preferably 1) opening at the proximal end opening 22 of the inner tube 12 as shown in FIG. ID and FIG. (About 10 cm) At the position where the vehicle has climbed over, it is joined to the inner wall of the first outer tube member 6 a by means of heat fusion or adhesion.

The maximum outer diameter of the reinforcing rod 28 is determined so as to be able to be inserted into the fourth lumen 26 of the second outer tube member 6b, and is not particularly limited, but is preferably 0.3 to 0.6. mm.

The balloon portion 4 shown in FI G.1A and FI G.2 is formed of a cylindrical film having both ends reduced in diameter, and has a film thickness of 10 to 40 // m, preferably 15 ~ 35 m. The balloon portion 4 is not particularly limited as long as it is cylindrical, and may be cylindrical or polygonal. The outer diameter of the balloon portion 4 when expanded is generally about 1.5 to 10 Omm, preferably 3 to 7 mm. Although the axial length of the balloon portion 4 is not particularly limited, it is 15 to 50 mm, preferably 20 to 40 mm. The balloon portion 4 before being expanded is folded and wound around the inner tube 12 so that the outer diameter is as small as possible.

As shown in FIG. 2, the proximal end 5 of the balloon 4 is joined to the outer periphery of the distal end of the first outer tube member 6 a by means such as heat fusion or adhesion. The first lumen 10 of the first outer tube member 6 a communicates with the space for internal expansion of the valve unit 4. The distal end portion 7 of the balloon portion 4 is joined to the outer periphery of the distal end portion of the inner tube 14 by means such as heat fusion or adhesion, and the internal expansion space of the balloon portion 4 is Except for the first lumen 10, it is sealed to the outside. The first lumen 10 of the first outer tube member 6 a sends fluid into the internal expansion space of the balloon section 4 to expand the balloon section 4, or draws fluid out of the expansion space of the balloon section 4, and removes the fluid from the balloon section 4. It is a passage for contracting.

As shown in FIG. 2, the inner tube 12 extends coaxially in the axial direction through the expansion space of the valve portion 4 and the inside of the first lumen 10 on the distal end side of the first outer tube member 6a. It has a so-called coaxial catheter tube structure. A contrast ring 15 is attached to the outer periphery of the inner tube 12 located inside the balloon part 4, and when the balloon force catheter 2 is inserted into the living body, it is exposed to X-rays from the outside of the living body. The position of the imaging ring 15 can be imaged. 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 a distal end opening 20 thereof is open at a distal end 7 of the ball portion 4. The proximal end opening portion 22 of the inner tube 12 is opened to the outside through a through hole 21 of a tube wall located in the longitudinal direction of the first outer tube member 6a.周 The periphery of the proximal end opening 22 of the tube 12 and the periphery of the through hole 21 of 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, the opening end of the inner tube 12 is formed obliquely. It is a cut elliptical shape. The second lumen 14 of the inner tube 12 is a guide wire insertion lumen through which a guide wire 42 shown in FIG. 2 for guiding the balloon catheter 2 into a body cavity is inserted.

The inner tube 12 can be made of a soft synthetic resin of the same material as the first outer tube member 6a, but may be made of a synthetic resin 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 may be a position of length L1 from the distal end of the first outer tube member 6a. Preferably, the length L1 is preferably between 150 and 35 Omm, more preferably between 200 and 30 Omm.

The outer diameter of the first outer tube member 6a is not particularly limited, but is preferably 0.5 to 5 mm, more preferably 0.5 to 1 mm. The thickness of the first outer tube member 6a is Although not particularly limited, it is preferably from 0.05 to 0.5 mm, more preferably from 0.1 to 0.2 mm.

The outer diameter of the inner tube 12 is determined so that a gap is formed 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. The inner diameter of the inner tube 12 is not particularly limited as long as it can pass through the guide wire 42, and is, for example, 0.15 to 1.0 mm, preferably 0.25 to 0.6 mm.

In the present embodiment, in order to reinforce the strength of the first outer tube member 6 a on the proximal end side from the vicinity of the opening 22, as shown in FIG. It may be arranged inside the first outer tube member 6a on the distal end side. The proximal end of the reinforcing mouthpiece 28 is circular in cross section, tapered from the middle toward the distal end side, and has a flat cross section at the distal end. The cross-sectional shape is gradually changing. As shown in FIG. 2, the distal end of the reinforcing tab 28 having a flat cross section rides the proximal end opening 22 of the inner tube 12 slightly (preferably about 1 to 10 cm). At the position beyond, it is joined to the inner wall of the first outer tube member 6a by means such as heat sealing or bonding.

The reinforcing rod 28 is made of a metal material such as stainless steel, copper, copper alloy, titanium, or titanium alloy, or a synthetic resin such as polyimide, polyamide, or 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.

3 to 0.6 mm.

The first outer tube member 6a may be made of, for example, a material similar to that of the balloon portion 4, and is preferably made of a material having flexibility. For example, polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polychlorinated vinyl (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide Elastomer, Polyimide, Polyimide elastomer, Polytetrafluoroethylene resin, Polytetrafluoroethylene 16-propylene copolymer resin, Polytetrafluoroethylene-fluoroalkylvinylether copolymer resin, Trifluoride Ethylene chloride resin, tetrafluoride ethylene-ethylene Synthetic resin, polyvinylidene fluoride resin, polyvinyl fluoride resin, silicone rubber, natural rubber, and the like. Of these, polyethylene, polyamide, and polyimide are preferred. As the hardness of the first outer tube member 6a, a member having a J13 hardness of about 508 to 90 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, a member having a JIS hardness of about 50D to 75D can be used.

In the present embodiment, the outer periphery of the outer tube 6 composed of the first outer tube member 6a and the second outer tube member made of fluororesin is coated with a hydrophilic polymer substance having lubricity in a wet state. Preferably, the material is coated. Industrial applications

The balloon for a balloon catheter of the present invention can be used, for example, as a balloon for a PTC A balloon force terminal. The balloon for balloon catheters of the present invention generally has a thinner balloon film thickness than a balloon obtained by blow molding a polyethylene resin near its melting point (110 ° C.). Because of its high breaking strength, the diameter of the PTCA balloon catheter can be reduced. Furthermore, it can withstand high pressure for balloon dilatation, and when used as a PTCA balloon catheter, it is extremely safe when dilating a vascular stenosis.

Claims

The scope of the claims

1. A balloon formed by professional molding using a crosslinked tube made of a polyolefin resin, wherein the balloon has a film thickness of 10 to 40 μm and the balloon has a breaking strength of 800 to Balloon force for a catheter characterized by a weight of 200 kg / cm ² .

2. A polyolefin resin produced by a polymerization reaction using olefins having 2 to 40 carbon atoms as a monomer and having a density of 0.95 g / cm ^{3 or} less. A balloon for a balloon catheter according to claim 1.

3. The polyolefin resin according to claim 1 or 2, wherein the polyolefin resin is selected from polyethylene and a copolymer of ethylene and α-olefin having 4 to 40 carbon atoms. For knowledge.

4. A step of preparing a cross-linked tube having a gel content of 0.2 to 0.8% by electron beam cross-linking a tube made of polyolefin resin, and a temperature lower than the melting point of the polyolefin resin by 10 ° C or more. By applying a primary professional pressure to the cross-linking tube, and then applying a secondary blow pressure, which is lower than the primary blow pressure, to the cross-linking tube, it is effective to reach the balloon from the cross-linking tube to the balloon. Blow molding to prepare a balloon portion so that the stretching ratio is 500 to 100%.

5. The method for producing a balloon for a balloon force tail according to claim 4, comprising irradiating the tube made of polyolefin resin with an electron beam of 5 to 4 OMrad to crosslink the tube with an electron beam.

6.1 Tsugibu opening one pressure is ^{1 5~2 5 kgf / "cm 2} , manufactured balloon catheter balloon according to claim 4 or 5 secondary blow pressure is 5 to 8 kgf / cm ² Construction method.

7. an outer tube in which at least one balloon inflation lumen is formed along a longitudinal direction; and a proximal end of a balloon portion joined to a distal end of the outer tube; A distal end portion of the balloon portion, the distal end portion of the inner tube being formed so as to form a sealed expansion space inside the balloon portion. An inner tube that is joined to the distal end, and has an inner tube extending in the axial direction inside the balloon portion and inside the balloon expansion lumen of the outer tube, wherein the balloon portion is formed of a polyolefin resin. A balloon formed by professional molding using a tube, wherein the balloon has a film thickness of 10 to 40 μm and the balloon has a breaking strength of 800 to 2000 kgί / cm ^2. A balloon catheter, characterized in that:

8. The balloon catheter according to claim 7, wherein the balloon catheter is a balloon catheter for percutaneous intravascular coronary angioplasty.

9. The balloon catheter according to claim 7, wherein the balloon catheter is a monorail balloon catheter for percutaneous intravascular coronary angioplasty.

10. The outer tube is composed of a relatively flexible first outer tube member and a relatively rigid second outer tube member 6b, and the inner tube has a proximal end opening, The first outer tube member is opened to the outside through a tube wall located in the middle of the longitudinal direction of the first outer tube member, and the proximal end opening of the inner tube and the tube wall of the first outer tube member are heat-sealed in an airtight manner. 10. The balloon catheter according to claim 7, wherein the balloon catheter has a structure.