JPH067428A - Catheter - Google Patents

Abstract

PURPOSE:To provide a balloon having improved flexibility without sacrificing the size stability by molding polyallylene sulfide (PAS) or PAS polymer alloy using PAS as a constituent to form the balloon for a balloon catheter. CONSTITUTION:PAS or PAS polymer alloy using PAS as a constituent is molded to form a balloon for a balloon catheter. This balloon is excellent in heat resistance due to the characteristic of the constituting material, it is not deformed under plasma treatment (corona treatment), and its adhesiveness can be improved by the reformation under plasma treatment. The balloon is not peeled during usage or storage. Surface treatment such as resin coating or chemical coating can be applied, it is excellent in persistence, and an anti-thrombogenic material can be easily coated on the outer surface of the balloon.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel balloon used for a balloon catheter.

[0002]

2. Description of the Related Art In recent years, a balloon catheter having a balloon (expansion body) at its distal end is applied to various body cavities such as blood vessels, and its usefulness is increasing in the medical field.

Among such balloon catheters, a vasodilating catheter is used for percutaneous transluminal coronary angioplasty (PTCA) for dilating a narrowed portion of a blood vessel such as a coronary artery or for dilating a narrowed portion of a peripheral blood vessel. It is applied to percutaneous transluminal coronary angioplasty (PTA). In this PTCA, for example, the femoral artery is secured by the Seldinger method, the tip of the guarding catheter is inserted from here to the entrance of the target coronary artery, and the balloon of the vasodilator catheter is positioned in the stenosis through this. After that, a dilating fluid is fed into the balloon through the lumen formed in the blood vessel dilatation catheter to dilate the balloon and dilate the stenosis.

[0004] In such a vasodilator catheter, it is required that it has a followability (trackerability) that allows it to easily pass through a guarding catheter and smoothly advance to a target lesion along a meandering blood vessel. It is preferable that the balloon has sufficient strength and flexibility, is excellent in dimensional stability, and does not excessively expand the narrowed portion.

By the way, as a conventional technique relating to a balloon of a balloon catheter, US Pat.
No. 3484, No. 4154244, No. 425477
No. 4, No. 4906244, No. 510812, and International Application PCT / JP88 / 00202.

As the constituent material of the balloons described therein, ethylene-butylene-styrene block copolymer is mixed with low molecular weight polystyrene and polypropylene is added at any time, and butadiene or isoprene is used in place of ethylene and butylene. Similar composition, polyvinyl chloride, polyurethane, polyester copolymer,
There are thermoplastic rubber, silicone, polycarbonate copolymer, ethylene-vinyl acetate copolymer, biaxially oriented nylon 12, biaxially oriented polyethylene terephthalate, polyethylene and cross-linking type ethylene-vinyl acetate copolymer.

Particularly, as a constituent material of a balloon in a catheter for vasodilation, polyvinyl chloride (hereinafter, referred to as PV
C), polyethylene (hereinafter also abbreviated as PE), biaxially oriented nylon 12 (hereinafter also abbreviated as N12), biaxially oriented polyethylene terephthalate (hereinafter,
(Abbreviated as PET) and the like are used.

Of these, aliphatic polymer materials such as PE, PVC, and N12 are rich in flexibility and have good catheter followability, but have the drawback of poor dimensional stability due to their low strength.

On the other hand, PET has high strength and excellent dimensional stability, but since it is biaxially oriented crystallized, it has a high elastic modulus.
It has drawbacks such as poor impact resistance and abrasion resistance, poor flexibility, and poor catheter followability.

Further, PET is inferior in coating property, adhesive property and heat sealing property, and therefore, there is a drawback that workability and secondary processability in manufacturing a balloon catheter are poor. In connection with this, it was difficult to apply various modifications to the PET balloon, which is originally poor in antithrombogenicity, to be a balloon particularly excellent in blood compatibility.

Further, since medical instruments are used directly on the human body, they must be sterilized and disinfected for safety. However, catheter balloons using PE, PVC, N12 and PET of the prior art are heat resistant and radiation resistant. Because it is inferior
High-pressure steam (autoclave) sterilization and γ-ray sterilization cannot be performed,
Ethylene oxide gas (hereinafter also abbreviated as EOG)
Has been sterilized. Residue of EOG in the product causes hemolysis, and therefore, for example, it takes one week to remove EOG, which is a problem in terms of safety and productivity.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a balloon used for a flexible balloon catheter having improved flexibility without sacrificing dimensional stability. What to do
An object of the present invention is to provide a balloon for a catheter for vasodilation, in which the inner surface of the blood vessel is prevented from being damaged by controlling the elastic modulus.

[0013]

These objects are achieved by the present invention described in (1) to (7) below.

(1) Polyarylene sulfide (hereinafter,
PAS) or PAS with PAS as one component
A balloon for a balloon catheter obtained by molding a polymer-based alloy.

(2) A balloon for a balloon catheter obtained by multi-layer extrusion molding of the PAS or the PAS-based polymer alloy and olefin.

(3) The PAS comprises polyphenylene sulfide (hereinafter referred to as PPS), polythioether ketone, polythioether thioether ketone, polythioether ketone ketone, polyether thioether, polythioether sulfone, polybiphenylene sulfide and polynaphthalene sulfide. The balloon for a balloon catheter according to (1) or (2), which is at least one selected from the group.

(4) The balloon for a balloon catheter according to (1) or (2), wherein the PAS is a high molecular weight PPS.

(5) Calculated elastic modulus is 70 to 200 kg / m
The balloon for a balloon catheter according to any one of (1) to (4), which is m ² .

(6) The balloon for a balloon catheter according to any one of (1) to (5), which has a breaking pressure of 10 kg / cm ² or more.

(7) The balloon for a balloon catheter according to any one of (1) to (6), wherein the PAS or PAS-based polymer alloy containing PAS as a constituent component is formed by biaxial stretching orientation.

[0021]

The PET has high strength, high elastic modulus and excellent dimensional stability, but lacks flexibility and absorbs water insufficiently to cause a decrease in molecular weight during molding, resulting in a decrease in strength and stretching. Balloon molding is difficult due to poor performance.
On the other hand, the aliphatic polymers such as PE, PVC and N12 are flexible and have good followability of the catheter for vasodilation, but have low strength and poor dimensional stability.
Strength deterioration and dimensional changes easily occur due to temperature changes and water content.

On the other hand, the balloon used in the balloon catheter of the present invention (hereinafter also simply referred to as a balloon)
Is a polyarylene sulfide having excellent dimensional stability or a polyphenylene sulfide obtained by copolymerizing a flexible component with or blending a flexible component with polyarylene sulfide, which is modified and polymerized into a polymer alloy, as the constituent material. An excellent, flexible and supple balloon can be obtained.

Such a supple balloon having excellent dimensional stability gives little shock to the inner surface of the blood vessel when the catheter is introduced into the blood vessel, and can prevent damage to the inner surface of the blood vessel.

Further, by suppressing the elastic modulus, the balloon becomes highly flexible and can be folded into a small size.
Since a material such as PET has a high elastic modulus and is hard, when the balloon is folded, a fluttering occurs, which makes the balloon small and difficult to fold.

On the other hand, the balloon of the present invention has
Due to the flexibility, it is possible to make a small fold when the folding is less likely to occur.

Further, the balloon of the present invention is excellent in the ability of the catheter to follow the target lesion. That is, the followability of the catheter is an important factor in that the folded balloon (shell) is flexible in addition to the fact that the balloon can be folded small. Although it has been clinically pointed out that the PET balloon has poor shell flexibility and poor catheter followability, the balloon of the present invention has sufficient shell flexibility and flexibility. Therefore, the followability of the catheter is good.

Since the balloon of the present invention is superior in heat resistance to PET due to the characteristics of its constituent material, it does not deform even when subjected to plasma treatment (corona treatment). Therefore, if necessary, it is also possible to improve the adhesiveness by modifying the plasma treatment. In particular, since the adhesive strength is improved as compared with PET, peeling of the balloon does not occur during use, storage, etc. Furthermore, since it has excellent adhesiveness to other resins and chemicals, surface treatment such as resin coating and application of chemicals is possible, and its durability is also excellent.

Therefore, for example, the outer surface of the balloon can be easily coated with an antithrombotic material or an antithrombotic agent, and excellent blood compatibility can be maintained for a long time. In addition, for other purposes, for example, surface treatment for smooth movement in viscous blood flow or for preventing damage to the inner surface of the blood vessel during movement can be performed.

Further, the balloon of the present invention is excellent in heat resistance and has a very low water absorption rate due to the characteristics of the constituent material of the balloon, so that high pressure steam sterilization is possible. Since conventional materials such as PET have low heat resistance and water absorbency, 121 ° C, 1.1 kg / c in steam, which is the condition for general high-pressure steam sterilization.
After the sterilization treatment of m ² for 20 minutes, the balloon is deformed and the strength is reduced. Even under such severe sterilization conditions, the balloon of the present invention does not change and its strength does not decrease due to repeated sterilization operations. Further, the balloon of the present invention is excellent in radiation resistance due to the characteristics of the constituent materials, so that γ-ray sterilization is possible.

Therefore, high-pressure steam sterilization or γ-ray sterilization other than ethylene oxide gas sterilization that may cause hemolysis can be performed, and is preferable when used as a balloon of a vasodilator catheter that comes into direct contact with blood.

The aliphatic polymers such as PE, PVC and N12 have flexibility, but have low calculated elastic modulus and low burst pressure. Further, although the PET balloon has a high burst pressure, it is difficult to collect the broken balloon fragments that have been shattered and shattered once they burst. On the other hand, the balloon of the present invention does not rupture even when a pressure of about 10 atm is applied for balloon expansion, and even if it ruptures in a living body, it causes linear rupture. Therefore, it is safe without being lost.

The balloon used in the balloon catheter of the present invention uses, as the constituent material, polyarylene sulfide having excellent dimensional stability, or uses this polyarylene sulfide as one constituent component, particularly a main constituent component. A polyarylene sulfide-based polymer alloy modified by blending a resin that imparts flexibility (elasticity) or copolymerizing a soft component is used. The calculated elastic modulus of the balloon is 70 to 200 depending on the composition ratio.
The desired physical properties are obtained by adjusting to the range of kg / mm ² .

In the present invention, polyarylene sulfide is a sulfur-containing aromatic polymer typified by polyphenylene sulfide (hereinafter abbreviated as PPS).
Other than S, polythioether ketone, polythioether thioether ketone, polythioether ketone ketone, polyether thioether, polythioether sulfone,
Polybiphenylene sulfide, polynaphthalene sulfide and the like are polymers characterized by having an aromatic compound as a repeating unit and having sulfur as a bonding group.
Of these, polyphenylene sulfide is particularly preferable.

The polymerization degree of such polyarylene sulfide is preferably about 50 to 5,000, particularly about 100 to 3,000, and the average molecular weight is preferably about 5,000 to 500,000, particularly preferably about 10,000 to 300,000. Crystallinity is 0-6
0, especially 5 to 40 is preferable.

In the present invention, such a polyarylene sulfide is used alone, and this polyarylene sulfide is used as a main constituent component, and a resin for imparting flexibility (elasticity) to a balloon is blended with this polyarylene sulfide, or a flexible component is used. A polyarylene sulfide-based alloy copolymerized into a polymer alloy is used. The polymer alloy is a concept including polymer blend, graft copolymerization, block copolymerization (micro phase separation structure) and random copolymerization. Further, when forming a polymer alloy, an alloying agent, a compatibilizing agent, a stabilizer or the like may be used, if necessary.

The modification of polyarylene sulfide by polymer blending includes, for example, various thermoplastic resins such as modified polyolefin, fluororesin, polyethylene, polyamide, polyester, polystyrene, polycarbonate, polyphenylene oxide, polyetherketone and polyetherimide. Among these, 1 type (s) or 2 or more types can be used. Also, a blend of polyarylene sulfides can be used. Of these, PPS polymer blends are preferable because they are easily available and have good processability.
Further, a polymer blend of high molecular weight linear PPS and polystyrene is particularly preferable in terms of improvement of flexibility and adhesion.

The blending amount of the resin which imparts such flexibility is preferably 50% by weight or less, and particularly preferably 0 to 40% by weight. If it exceeds 50% by weight, the elastic modulus and strength of the balloon become too low, and sufficient dimensional stability may not be obtained.

The modification of the polyarylene sulfide by copolymerization includes, for example, random copolymerization of polyarylene sulfides or reduction of crystallinity due to block copolymerization, block copolymerization of an elastomer component, and the like. From the viewpoint of easy availability and good processability, PPS in which the composition of the meta component is random copolymerized or block copolymerized is preferable, and the composition of the meta component is preferably less than 50%. In particular, the content of the meta component is 0 to 30.
It is preferably set to wt%. In order to reduce the crystallinity of PPS, suppress the elastic modulus to a low level, and maintain the dimensional stability, it is desirable that the crystallinity remains. When the content of the meta component exceeds 50% by weight, the random copolymerization becomes amorphous and it becomes difficult to mold the balloon by biaxial stretching.

The balloon of the present invention is fused to a balloon catheter made of a resin material such as polyvinyl chloride or polyethylene by a predetermined heating means, or an epoxy resin or a cyanoacrylate adhesive. Although it is adhered using an adhesive (solvent) such as, due to the nature of the constituent material of the balloon, it has excellent heat resistance,
The balloon does not deform even after corona treatment. Therefore, the adhesiveness (adhesiveness) with the balloon catheter can be improved, and in particular, the adhesive strength can be increased. Therefore, it is structurally advantageous and is safe without peeling of the balloon during use and storage.

The balloon of the present invention is obtained by molding the above polyarylene sulfide or a polyarylene sulfide-based polymer alloy containing the polyarylene sulfide as a main component, preferably by biaxial stretching orientation.

As one example, first, a tube (tubular body) made of the above polyarylene sulfide or a polyarylene sulfide-based alloy containing the polyarylene sulfide as a main component is prepared, and this tube is pulled or pulled in the axial direction of the tube, for example. To stretch. In addition, this stretching is
For example, it is preferably carried out under heating at 45 to 150 ° C.

In this case, it is preferable that the length of the tube after stretching is about 1.5 to 5 times that before stretching.

Next, in the vicinity of the central portion in the longitudinal direction of the tube,
A mold having a concave portion (cavity) in the expanded state of the balloon is fitted, and while heating at 45 to 150 ° C., the inside of the tube is pressurized to expand the tube in the heated portion in the radial direction. In this case, the tube radius after expansion is preferably about 2 to 8 times that before expansion. The balloon thus obtained has a thickness of 5 to 50 μm.
m, preferably 5 to 30 μm.

After a certain period of time (for example, 1 second to 5 minutes) in the above heating-pressurized state, the tube is cooled to near room temperature while maintaining the pressurized state. As a result, the tube is stretched in the radial direction and formed into a desired balloon shape. The heating and cooling may be repeated a plurality of times in order to remove the strain of the balloon.

After cooling to near room temperature, the pressurized state inside the tube is released, the mold is removed, and unnecessary portions of the tube are cut and removed to obtain the balloon of the present invention.

In the balloon of the present invention, a tube (tubular body) is prepared by multi-layer extrusion molding of the polyarylene sulfide and / or the polyarylene sulfide polymer alloy containing the polyarylene sulfide as a main component and an olefin.
This tube is biaxially stretched in the same manner as above to obtain a balloon.

As the above-mentioned olefin used here, almost any polyolefin which has been used for medical purposes can be used. For example, polypropylene, polyethylene, ethylene-propylene copolymer,
It is preferable to use ethylene-vinyl acetate copolymer, modified polyolefin such as modified polyethylene or modified polypropylene, or olefin elastomer.

Further, a balloon obtained by biaxially stretching a tube (tubular body) formed by multi-layer extrusion molding of the above polyarylene sulfide and / or a polyarylene sulfide-based polymer alloy containing the polyarylene sulfide as a main component and an olefin, Strictly PAS because it is a two-component non-uniform material
No distinction can be made between layers and / or PAS-based polymer alloy layers and olefin layers. As an embodiment of the balloon for the balloon catheter used in the present invention, FIG.
FIG. 1 is a schematic enlarged cross-sectional view of a balloon obtained by biaxially stretching a tube formed by multi-layer extrusion molding of AS, PAS-based polymer alloy (PAS / olefin 1: 1 (weight ratio) blend) and olefin. From FIG. 3, the cross-sectional structure of the balloon 21 has a PAS layer 22 as an inner layer and a PS layer as an intermediate layer.
It has a three-layer structure composed of a blend layer 23 of AS and olefin and an outer olefin layer 24.
The boundary between the layer 22 and the blend layer 23, and the boundary between the blend layer 23 and the olefin layer 24 are not clear, and the layers are integrated to such an extent that they cannot be peeled and separated. The preferred thickness of each layer in the configuration shown in FIG.
It is desirable that the layer 22 has a thickness of 5 to 7 μm, the blend layer 23 has a thickness of 1 to 2 μm, and the olefin layer 24 has a thickness of 5 to 7 μm, and the total thickness of the balloon 21 is in the range of 11 to 16 μm.

The balloon of the present invention molded as described above has a calculated elastic modulus of 70 to 200 kg / mm ² .

If the calculated elastic modulus is less than 70 kg / mm ² , the strength of the balloon will be low and the dimensional stability will be poor.
When it exceeds 00 kg / mm ² , the flexibility becomes poor, the followability of the catheter deteriorates, and the burr is liable to be generated, so that the balloon is easily damaged by the friction with the guide catheter.

The calculated elastic modulus E here is obtained from the calculated tensile strength Sc (tensile strength in the radial direction of the film equation) of the film shown in the following formula 1. Actually, the tensile strength and elastic modulus of the balloon in water are calculated.

[0052]

[Equation 1]

The calculated elastic modulus E is defined by the inclination of the straight line portion in which the strain (balloon expansion coefficient) is plotted against the strength (stress) Sc and the Hooke's law is satisfied. That is, it is the initial elastic modulus of the balloon and is represented by the following mathematical formula 2.

[0054]

[Equation 2]

Although the thickness of the balloon in the present invention is not particularly limited, it is preferably about 5 to 30 μm.

PE excellent in conventional strength and dimensional stability
The calculated elastic modulus of the T balloon is 200 to 250 kg / mm.
There were about ² balloons that were hard. In the present invention, by using a polyarylene sulfide or a polyarylene sulfide-based alloy containing the polyarylene sulfide as a main component, the calculated elastic modulus is set to 70 to 200 kg / mm ² , which makes it excellent in dimensional stability, and flexible and flexible. It becomes possible to obtain a balloon.

Even in the PET balloon, it is possible to control the elastic modulus by decreasing the draw ratio, but in that case, the stress-strain curve plotted in the pressure resistance test for calculating the calculated elastic modulus is used. At the yield point, the dimensional stability and strength are significantly reduced at the yield point. Pressurization beyond the yield point can no longer return to the original shape and size after expansion of the balloon, making recovery of the balloon difficult. Therefore, the expansion pressure of the balloon that can be actually used is greatly limited.

On the other hand, with the balloon of the present invention, a flexible and flexible balloon can be obtained while maintaining sufficient dimensional stability and strength. Therefore, when the balloon is used as a vasodilator catheter, It is possible to prevent the inner surface of the blood vessel from being damaged when it is inserted into the blood vessel.

The balloon of the present invention has a high glass transition temperature, is crystalline and has excellent heat resistance, has a very low water absorption rate, is excellent in chemical resistance, and is inert due to the characteristics of the constituent materials. Therefore, for example, sterilization with high-pressure steam or γ-rays is possible, and it is not necessary to sterilize with ethylene oxide gas. It is preferable because there is no fear of hemolysis due to residue. Furthermore, it is advantageous that a step that requires a long time for removing the ethylene oxide gas can be omitted.

The burst pressure of the balloon of the present invention is 1
It is preferably 0 kg / cm ² or more, and 13 to 20 k
More preferably, it is g / cm ² . In normal use, the pressure for expanding the balloon is about 7 to 8 atmospheres, but if the bursting pressure of the balloon is 10 kg / cm ² or more, not only in this range but also when a higher pressure is applied, The burst pressure can be prevented. Further, it can be applied to titided stenosis which requires high pressure.

As described above, the balloon used in the balloon catheter used in the present invention is not limited to the balloon used in the vasodilation catheter, and many balloons including insertion into various body cavities are used. It is useful as a balloon used in balloon catheters used for medical purposes.

[0062]

EXAMPLES Specific examples of the present invention will be described below.

Example 1 As the polyarylene sulfide (hereinafter abbreviated as PAS), ultra-high molecular weight linear poly-p-phenylene sulfide (hereinafter abbreviated as PPS) was used. As the PPS, grade E0780, MF manufactured by Toray PPS Co., Ltd. (former Toray Phillips Petroleum Co., Ltd.)
R = 7 [g / 10 min] (316 ° C.), melting point 280 ° C.
Was used. This PPS has an inner diameter of 0.5 mm and an outer diameter of 0.85.
It was extruded and molded into a mm-shaped tube. This tube was stretched 2.5 times in the axial direction of the tube in an atmosphere of 105 ° C., and then inserted into a metal cylindrical tube having a tapered portion and a cylindrical cavity having an inner diameter of 3 mm.

After heating the cylindrical tube to 105 ° C., nitrogen gas was introduced from both ends of the tube into the tube at 12 kg / cm ^2.
Was applied for 15 seconds, and then the pressure was maintained for 1 minute for cooling.

After that, while maintaining the pressure, the temperature of the cylindrical tube was again raised to 125 ° C., and heat setting was performed for 20 seconds.
Then, it cooled to room temperature over 1 minute and 30 seconds.

The pressure was released, the biaxially stretched and oriented balloon was taken out from the cylindrical tube, and unnecessary portions were cut and removed to obtain the balloon of the present invention. The outer diameter of the expanded part of this balloon is 3m
m, and the film thickness was 14.3 μm.

Example 2 As PPS, grade M2 manufactured by Toray PPS Co., Ltd. (former Toray Phillips Petroleum Co., Ltd.)
088, MFR = 94 [g / 10 min] (316
C.), melting point 280.degree. This PPS has an inner diameter of 0.5
mm, and an outer diameter of 0.90 mm was formed in a tubular shape. This tube was stretched 3 times in the axial direction of the tube in an atmosphere of 105 ° C., and then the tapered portion and the inner diameter of 3 mm
It was inserted into a metal cylindrical tube having a cylindrical cavity. Hereinafter, in the same manner as in Example 1, the outer diameter of the expanded portion is 3 m.
m and a film thickness of 15.0 μm were obtained.

Example 3 As a PAS alloy, PP manufactured by Kureha Chemical Industry Co., Ltd.
Using S-based polymer blend grade T-300,
As in Example 2, the outer diameter of the expanded portion was 3 mm, and the film thickness was 1
A balloon of 4.5 μm was obtained.

Example 4 As a PAS alloy, 10% meta-modified PPS (hereinafter abbreviated as M10PPS) was synthesized by the following method. That is, while stirring the otoclave, 63.6 g (0.5 mol) of sodium sulfide, 123.3 g of N-methyl-2-pyrrolidone and 51.0 g of lithium acetate dihydrate.
(0.5 mol) was charged. The reaction mixture was prepared by heating for 2 hours and 5 minutes and dehydrated. Water for dehydration 27.
This gave 31 ml of distillate containing 8 g. When the reaction mixture reached a temperature of 205 ° C., 74.95 g of 1,4-dichlorobenzene was charged, and 4.9 to 7.0 kg.
After maintaining at 245 ° C for 3 hours at a pressure in the range of / cm ² gauge pressure (75 to 100 psi), the reactor was cooled to room temperature to give a dark gray product. The product was obtained by synthesizing by washing with 1 liter of water 8 times and drying in a vacuum oven at 80 ° C.

The random copolymerized PPS thus obtained contained 90% of para-phenylene sulfide component and 10% of meta-phenylene sulfide component, and had a melting point of 253 ° C. and MF.
R = 15 [g / 10 min] (280 ° C.).

A balloon having an outer diameter of the expanded portion of 3 mm and a film thickness of 15.3 μm was obtained in the same manner as in Example 2 using M10PPS.

Example 5 PPS was used as PAS. As the PPS, grade E1880, MFR = 7 manufactured by Toray PPS Co., Ltd. (former Toray Philippe Petroleum Co., Ltd.)
0 [g / 10 min, 316 ° C.], melting point 280 ° C. were used.

A modified polyolefin (hereinafter abbreviated as MPP) was used as the polyolefin. As the MPP, polypropylene-based grade P-310H of Modic commercially available from Mitsubishi Petrochemical Co., Ltd. as a highly adhesive polyolefin resin was used.

Next, the original tube was extruded by a usual method using three extruders. Extrusion molding uses PPS for the inner layer
PPS / MPP = 1: 1 for the intermediate layer using pellets
(Weight ratio) hand blended pellets, MPP for outer layer
Pellets were used. The obtained original tube has an inner diameter of 0.4
The outer diameter was 8 mm and the outer diameter was 0.91 mm. When the cross section of the original tube was examined, the boundary between the PPS layer and the MPP layer was not clear, and the PPS layer and the MPP layer could not be peeled and separated.

The original tube was stretched 3 times in the axial direction of the tube at an ambient temperature of 105 ° C. and then inserted into a metal cylindrical tube having a tapered portion and a cylindrical cavity having an inner diameter of 2.5 mm.

After the temperature of the cylindrical tube was raised to 105 ° C., a pressure of 12 kg / cm ² was applied to the tube from both ends of the tube with nitrogen gas, and the tube was pressurized for 15 seconds, and then the pressure was maintained for 1 minute 30 seconds. Cooled down. Cooling temperature is 25 ℃
Met.

After that, the temperature of the cylindrical tube was again raised to 150 ° C. while maintaining the pressurization, and immediately after the temperature reached 150 ° C., it was cooled to room temperature for 1 minute and 50 seconds.

After releasing the pressure, the stretched and heat-fixed balloon was taken out from the cylindrical tube, and the unnecessary portion was cut off to obtain the balloon of the present invention. The outer diameter of the expanded portion of this balloon when pressurized at 1 kg / cm ² is 2.29 mm, and the film thickness is 16.3 μm.
Met. Also, the PPS layer and MPP layer of this balloon could not be distinguished and could not be peeled off.

Comparative Example 1 Commercially available PET balloon (expanded portion outer diameter 3 mm, film thickness 1
0 μm) was prepared.

Comparative Example 2 Commercially available nylon 12 balloon (expanded portion has an outer diameter of 3 mm,
A film thickness of 8 μm) was prepared.

Experiment FIG. 1 is a schematic diagram showing the structure of an experiment conducted by attaching a balloon to a commercially available triple-tube vascular dilatation catheter. FIG. 2 is an enlarged cross-sectional view showing the configuration of the distal end side in which a balloon is attached to the blood vessel dilation catheter of FIG.

As shown in FIG. 1, the balloons 3 obtained in Examples 1 to 5 and Comparative Examples 1 and 2 are heat-melted on the outer peripheral portion of the distal end of the tube 2 of the triple-tube vascular dilatation catheter 1. Attached by wearing. Subsequently, distilled water was injected from an injector 6 with a pressure gauge connected to an injection port 5 of a three-way adapter 4 attached to the catheter 1, and the balloon 3 was filled with distilled water. In this case
As shown in Figure 3, a triple-tube vasodilator catheter tube 2
Is an inner tube 7 forming a first channel A having an open tip, an intermediate tube 8 surrounding the inner tube 7 and forming a second channel B between the inner tube 7 and the inner tube 7. It is composed of an outer tube 9 which surrounds the tube 8 and forms a third flow path C between the tube 8 and the middle tube 8. The outer tube 9 is coaxial with the triple tube type catheter tube 2. A closed space D having a groove-like portion and necessarily including the respective openings of the second flow path B and the third flow path C and communicating with the second flow path B and the third flow path C.
So that one end 10 of the balloon 3 is fixed to the outer periphery of the outer tube 9 by heat fusion at the base end side of the side hole 11 of the outer tube 9 and the other end 12 of the balloon 3 is formed. The inner tube 7 is fixed and attached to the outer circumference of the inner tube 7 by heat fusion on the tip side of the side hole 13 of the middle tube 8 (note that when actually used as a vasodilator catheter, the first channel A is a blood flow). As a passage and a passage for the guide wire 13 (shown in FIG. 1), the second flow passage B acts as a residual air discharge flow passage, and the third flow passage C acts as a filling flow passage for a contrast agent or the like.
At the base end of the triple-tube catheter tube 2, the three-way adapter 4 shown in FIG.
Of the three-way adapter 4 are connected to the three flow passages of the triple-tube catheter tube 2, and the guide wire port 14 of the three-way adapter 4 has the first flow passage A.
The vent port 15 communicates with the second flow path B, and the injection port 5 communicates with the third flow path C). Therefore, by injecting distilled water from the injector 6 with a pressure gauge connected to the injection port 5, the third flow path C of the triple-tube catheter tube 2 can be obtained.
Distilled water is injected into the balloon 3 through the through hole, and the obturator (not shown) of the vent port 15 of the three-way adapter 4 of the other second flow path B is closed to close the closed space D of the balloon 3.
On the other hand, a rupture test was performed in which the pressure to the closed space D of the balloon and the deformation amount of the diameter of each balloon were recorded by gradually pressurizing at a rate of 1 kg / cm ² for 1 minute.

By this burst test, the burst pressure and the maximum expansion rate of the balloon were obtained, and the calculated tensile strength was calculated from the formulas 1 and 2 based on the data obtained in the test and the wall thickness and initial diameter of the balloon. And the calculated elastic modulus was obtained. The results are shown in Table 1 below.

[0084]

[Table 1]

As shown in Table 1, Examples 1 to 5 of the present invention
Each of the balloons obtained in step 1 has a calculated elastic modulus of 70.
~ 200kg / mm ² and burst pressure is 10k
It was as high as g / cm ² or more, and it was confirmed to have sufficient dimensional stability and flexibility.

Further, the balloon obtained in Example 5 of the present invention gave a soft feel of polyolefin, and had excellent pressure resistance and dimensional stability even though the balloon was very soft.

On the other hand, the calculated elastic modulus of the balloon obtained in Comparative Example 1 was as high as 232 kg / mm ^2, and the measured elastic modulus was 200 to 250 kg / mm ² as a result of measuring various PET balloon samples. Was in the range. Since the PET balloon has such a high elastic modulus, the PET balloon becomes poor in flexibility.

Therefore, in order to reduce the elastic modulus, a sample having a reduced draw ratio was prepared. That is, using a PET tube, a balloon having an outer diameter of the expanded portion of 3 mm and a diameter of 15.5 μm was obtained in the same manner as in Example 1 except that the stretching temperature was 85 ° C. and the stretching ratio in the tube axial direction was 2.67. Got

As a result of subjecting this balloon to the same burst test as described above, the calculated tensile strength was 16.8 kg / mm ² , and the calculated elastic modulus was 130 kg / mm ² . At this time, the burst pressure was 18.2 kg / cm ² , and the maximum expansion rate was 2
It was 2.5%.

However, the yield point remarkably appears in the stress-strain curve, and when this is seen as the correlation between the pressure and the diameter of the balloon (compliance of the balloon), the pressure of the balloon suddenly increases at a certain pressure (10 kg / cm ² ). There was a dimensional change. That is, after the yield point, the balloon was plastically deformed and expanded rapidly. In fact, the balloon did not return to its original size after depressurization.

As described above, even if the elastic modulus is simply lowered by adjusting the stretching ratio and the like, the yield point appears, so that it is not a desirable balloon, and the pressure that can actually be used is lower than the yield point. I don't get it. In addition, the balloon that has undergone such plastic deformation in the living body is not preferable because it does not return to the original shell size at the time of collection, and is easily crushed in the shape of a flap to make it difficult to pass through the guide catheter and difficult to collect.

Further, in the balloon obtained in Comparative Example 2,
The calculated elastic modulus is as low as 43.9 kg / mm ^2, and the burst pressure is also as low as 9.0 kg / cm ² . Even in normal use, the pressure to expand the balloon is 7-
The pressure is about 8 atm, but depending on the surgeon, there is an example in which a pressure of 10 atm or more is applied. Therefore, the burst pressure is 10 kg.
If it is less than / cm ² , the strength is insufficient.

The shape of the balloon at the time of bursting was such that the balloons obtained in Examples 1 to 5 of the present invention were in a state in which a tear was generated in the axial direction of the balloon, and the balloon could be easily recovered. Some of the PET balloons with a high rate had flying fragments, and it was difficult to collect the scattered balloon fragments.

If such a non-recoverable rupture occurs in a living body, it may cause clogging of coronary arteries and peripheral blood vessels and is very dangerous. Since the balloon of the present invention causes a linear rupture, it does not become uncollectible even if it ruptures in vivo.

[0095]

As described above, the balloon used in the balloon catheter of the present invention has excellent dimensional stability,
And a flexible and supple balloon can be obtained. as a result,
The followability of the catheter to the target lesion is improved, and the inner surface of the blood vessel is prevented from being damaged when the catheter is inserted.

Further, the balloon of the present invention has excellent adhesiveness to the catheter, is structurally advantageous, and does not cause peeling of the balloon.

The balloon of the present invention can be easily surface-treated by coating the outer surface of the balloon with an antithrombotic material or an antithrombotic agent.

Further, since the balloon of the present invention has a high bursting pressure and a low elastic modulus and high impact resistance, it has a safety that can withstand high pressure and rapid balloon expansion.

Further, the balloon of the present invention has a heat resistance and chemical resistance as its constituent materials, and a low water absorption rate, so that it can be sterilized by high-pressure steam sterilization, γ-ray sterilization, etc. And the efficiency of workability is improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration when a balloon was attached to a triple-tube type vasodilation catheter and an experiment was conducted in an example of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a configuration of a distal end side in which a balloon is attached to the blood vessel dilation catheter of FIG.

FIG. 3 is one embodiment of a balloon for a balloon catheter used in the present invention, which is made by multi-layer extrusion molding of PAS, PAS-based polymer alloy (PAS / olefin 1: 1 (weight ratio) blend) and olefin. It is a cross-sectional schematic enlarged view of the balloon obtained by biaxially stretching a tube.

[Explanation of symbols]

1 ... Triple-tube vasodilator catheter 2 ... Triple-tube vasodilator catheter tube 3, 21 ... Balloon 4 ... Three-way adapter 5 ... Injection port 6 ... Pressure gauge-equipped injector 7 ... Inner tube 8 ... Middle tube 9 ... Outer tube 10, 12 ... End part of balloon 11 ... Side hole of outer tube 13 ... Side hole of middle tube 14 ... Guide wire port 15 ... Vent port 22 ... PAS layer 23 ... Blend layer 24 ... Olefin layer

Claims (1)

[Claims] 1. A catheter provided with a balloon obtained by molding a polyarylene sulfide or a polyarylene sulfide-based alloy having polyarylene sulfide as one constituent.