JP2009254836A - Balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical balloon and a balloon catheter which have high pressure resistance and are excellent in peripheral accessibility so as to be easily advanced into a peripheral blood vessel. <P>SOLUTION: The balloon 800 is formed of a composite material comprising high modulus short fiber 801 for reinforcement and matrix resin 802. Each fiber of the high modulus short fiber 801 is arranged in a nonaligned state into the balloon 800, and almost uniformly dispersed in the balloon 800. At least most short fiber 801a of the short fiber 801 is oriented in an almost definite oblique direction with respect to the longer axis direction. Partial short fiber 801b of the short fiber 801 is oriented in a direction different from that of the most short fiber 801a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a medical balloon catheter. In particular, the present invention can be inserted very easily into dilation balloon catheters, that is, into body cavities such as blood vessels, and into narrow stenosis, eccentric or meandering stenosis, or intra-body cavity bifurcations. The present invention relates to a dilatation catheter for dilating a stenosis.

  The balloon catheter for dilatation has a catheter inner / outer tube inserted into a body cavity and a cylindrical balloon joined to the catheter tube. This cylindrical balloon has a pressure resistance sufficient for expansion, and a balance with high permeability in blood vessels continues to be required. That is, it is desired to have a characteristic that can be easily inserted without damaging the narrowed portion, an eccentric narrowed portion, or a meandering narrowed portion without damaging the narrowed portion while being high withstand voltage. A balloon has been proposed.

First, balloon catheters made of various thermoplastic polymers can be mentioned. These thermoplastic polymers include polyethylene and ionomers, ethylene-butylene-styrene block copolymers mixed with low molecular weight polystyrene and optionally polypropylene, ethylene and butylenes of the aforementioned polymers. Similar compounds in which is substituted with butadiene or isoprene, polyvinyl chloride, polyurethane, (co) polyesters, polyamides and polyamide elastomers, thermoplastic rubbers, silicone polycarbonate copolymers, ethylene vinyl acetate copolymers. In recent years, a balloon made of thermoplastic polyimide has also been proposed as one of the options for forming the catheter (for example, Patent Document 1).
However, in recent years, a balloon catheter having higher balloon pressure resistance has been demanded.

  It is also known to use a material obtained by combining a long fiber (filament) with a resin as it is or using a structure such as weaving or knitting for the purpose of increasing the strength of the balloon, and hence the high pressure resistance.

  For example, Patent Document 1 proposes a plain fabric, satin fabric, twill fabric, basket fabric, braided body (blade), and winding in addition to the yarn form. However, in such a long fiber and its structure, the resin impregnation between the single fibers inside the yarn is generally unstable, and the unimpregnated portion often becomes defective. In particular, when multifilaments are used, unimpregnated defects often occur. In addition, a process for forming a fiber structure in the form of a balloon is necessary, and in the case of a small-diameter balloon, there are often drawbacks such as low production uniformity and low yield.

  On the other hand, Patent Document 2 discloses a balloon catheter including a balloon in which a short fiber-like reinforcing body is disposed and reinforced in a matrix polymer. This is because the reinforcing resin such as wholly aromatic polyester that forms liquid crystal in the molten state is melted in the extrusion cylinder while blending with the matrix resin, and is used for reinforcing the molten state by shearing orientation when extruded from the die discharge nozzle. By making the resin elongated in the extrusion direction, etc., and solidifying by water bath cooling, the reinforcing resin that was in the form of particles before melting is distributed in the matrix resin in the form of a cocoon (pulp) by shearing in the molten state. It proposes a method to set up. This dispersion form of the cage-like polymer can be achieved by increasing the draft ratio of ordinary extrusion, but can also be oriented in the tube circumferential direction by rotating the mandrel or out die of the die. This is also disclosed.

  However, according to the extrusion method disclosed in this publication, the matrix is formed in the form of a cocoon (pulp) by applying a rotational force and a shearing force while discharging the reinforcing resin from a predetermined number of die discharge nozzles. Since the reinforcing resin is disposed in the resin, these bowl-like (pulp-like) reinforcements are aligned with a number of rows corresponding to the number of die discharge nozzles. Therefore, there is a problem that the reinforcing body is not disposed at all between the rows, so that the reinforcing effect is poor and pinholes and tears can easily occur. In addition, as those skilled in the art who are familiar with the technology in the field can easily conceive, it is often impossible to expect a sufficient effect as a reinforcing material only by discharging from the molten state as described above. On the other hand, in order to increase the crystallinity of the reinforcing material by heat treatment, a high processing temperature is required, and the matrix resin side often deteriorates or melts and deforms. A liquid crystal polymer having a chemical structure in which the temperature at which the liquid crystal polymer can be molded and crystallized is reduced to a temperature that can withstand the matrix resin is often no longer sufficient as a reinforcing material.

JP-T 9-507148 US Patent Publication No. 2001/43998

  An object of the present invention is to provide a medical balloon catheter having a high reinforcing effect. Another object of the present invention is to provide a medical balloon and a balloon catheter having high pressure resistance and excellent peripheral reachability that can be easily advanced into peripheral blood vessels.

The above-described problems are achieved by the present inventions (1) to (6) below.
(1) In a balloon catheter having a balloon formed of a composite material composed of a high modulus short fiber for reinforcement and a matrix resin,
Each fiber of the high modulus short fiber is arranged in a non-aligned state in the balloon, and is distributed almost evenly in the balloon.
The composite catheter is characterized in that the high modulus short fibers are dispersed in the matrix resin by applying ultrasonic vibration when mixing the high modulus short fibers and the matrix material.
(2) The balloon catheter according to (1) above, wherein at least most of the high modulus short fibers are inclined obliquely in a substantially constant direction with respect to the major axis direction of the balloon. .
(3) The balloon catheter according to (2), wherein a part of the high modulus short fiber is obliquely inclined in a direction different from the direction.
(4) The composite material in which the high modulus short fiber is reinforced with at least one short fiber selected from the group consisting of carbon fiber, high modulus organic fiber, high modulus whisker, carbon nanotube, high modulus inorganic fiber or metal fiber. The balloon catheter according to any one of (1) to (3).
(5) The balloon catheter according to (4), wherein the high modulus short fiber is a nanocarbon tube.
(6) The balloon catheter according to any one of (1) to (5), wherein the high-modulus short fibers are subjected to a surface modification treatment that improves adhesion to the matrix material.

  The balloon catheter of the present invention is a catheter having a balloon formed of a composite material composed of a high modulus short fiber for reinforcement and a matrix resin, and each fiber of the high modulus short fiber is not aligned in the balloon. It is arrange | positioned in the state, It distribute | circulates substantially uniformly in the said balloon, It is characterized by the above-mentioned.

Therefore, since the balloon is reinforced by the high modulus short fibers throughout, the strength of the entire balloon is improved, and a balloon and a balloon catheter with less pressure holes and excellent pressure resistance are obtained. And the softness | flexibility (flexibility) of a balloon is sufficient, and the balloon catheter excellent also in the permeability (peripheral reachability) in the blood vessel can be provided.

  In addition, when at least most of the high modulus short fibers are oriented obliquely in a substantially constant direction with respect to the major axis direction of the balloon, the reinforcing short fibers are arranged in the longitudinal and circumferential directions of the balloon. Both forms are oriented, and both the hoop strength of the balloon and the strength in the longitudinal direction (long axis direction) are improved.

  Furthermore, when some of the high modulus short fibers are oriented obliquely with respect to the major axis direction of the balloon in a direction different from that of most of the short fibers, most of the short fibers are Since the balloon is reinforced by some short fibers in a direction different from the direction in which the short fibers are reinforced, the pressure resistance of the balloon can be further improved.

  In addition, when the high modulus short fiber is subjected to a surface modification treatment for improving adhesion with the matrix resin, the matrix resin can be sufficiently impregnated between the short fibers, and the reinforcing effect of the balloon Will increase.

  In particular, when the composite material is made of a material in which the high modulus short fibers are dispersed in the matrix resin by applying ultrasonic vibration when mixing the high modulus short fibers and the matrix resin, The short fibers are more evenly dispersed in the matrix resin, so that the reinforcing effect over the entire balloon becomes higher and the strength of the balloon is further improved.

It is a top view which shows the example of the aspect of the balloon in the balloon catheter of this invention. It is a schematic sectional drawing which shows the example of the aspect | mode of the laminated tubular body coextrusion die of this invention. It is a figure which illustrates typically the example of a laminated tubular body extrusion line containing the extrusion die of the present invention. It is drawing which shows an example of the manufacturing apparatus of the balloon of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  A catheter generally used in angioplasty to dilate and open a stenosis formed in the vascular system using a balloon-tip catheter is an over-the- There are wire-type (Over-the-wire) or non-over-the-wire type. Similar catheters can be used for stent placement. In the present specification, all these catheters are collectively referred to as balloon catheters.

  FIG. 1 is a plan view showing an example of a balloon in the balloon catheter of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of an embodiment of the laminated tubular body coextrusion die of the present invention. FIG. 3 is a diagram schematically illustrating an example of a laminated tubular body extrusion line including the extrusion die of the present invention. FIG. 4 is a drawing showing an example of a balloon manufacturing apparatus according to the present invention.

  As shown in FIG. 1, a balloon 800 in the balloon catheter of the present invention is a balloon made of a composite material composed of reinforcing high modulus short fibers 801 and a matrix resin 802. Each fiber of the high modulus short fiber 801 is almost uniformly dispersed in the balloon 800. The fibers of the high modulus short fibers 801 are not arranged in an aligned state throughout the balloon 800 but are arranged in an unaligned state. For this reason, a high pressure-resistant balloon that is sufficiently reinforced in any part of the balloon and does not easily cause pinholes or tears without forming a specific weak part can be obtained.

  The fiber length of the reinforcing short fibers 801 is not particularly limited, but is preferably 5 mm or less, more preferably 3 mm or less from the viewpoint of sufficient impregnation of the matrix resin 802 between the fibers. Particularly preferably, it is 1 mm or less. Further, the aspect ratio of each short fiber 801 (the ratio of the fiber length to the fiber diameter) is not particularly limited, but is preferably 10 times or more from the viewpoint of obtaining a sufficient reinforcing effect. Preferably it is 30 times or more, More preferably, it is 100 times or more.

  As shown in FIG. 1, the high modulus short fibers 801 are preferably oriented such that at least most of the fibers 2a are inclined obliquely in a substantially constant direction with respect to the major axis direction of the balloon. Accordingly, the reinforcing short fibers 801 are oriented in both the longitudinal direction and the circumferential direction of the balloon, and both the hoop strength and the longitudinal (long axis direction) strength of the balloon are improved.

  Further, in the configuration shown in FIG. 1, some of the short fibers 801b among the high modulus short fibers 801 are oriented obliquely with respect to the major axis direction of the balloon 800 in a direction different from that of the short fibers 801a. is doing. Thereby, since the balloon 800 is reinforced by the short fiber 801b in a direction different from the reinforcing direction by the short fiber 801a, the pressure resistance of the balloon 800 can be further improved. In addition, this invention is not limited to what the above-mentioned short fiber 801b exists, It does not interfere even if all the short fibers 801a orientate in the substantially same direction. The short fibers 801 may be substantially oriented only in the major axis direction (longitudinal direction) of the balloon. Due to this vertical orientation, even if the balloon is torn, it is torn in the vertical direction, so that the broken balloon can be prevented from falling into the blood vessel.

Examples of the short fibers 801 used in the present invention include the following.
(1) Carbon fiber system: carbon short fiber, carbon whisker, nanocarbon tube, etc. (2) Other inorganic short fiber system: potassium titanate short fiber, silicon carbide, short fiber (SiC fiber) and its whisker, alumina short Fibers, short glass fibers, etc. (3) Organic fiber: Liquid crystalline polyester short fibers such as poly-p-hydroxybenzoate copolymer, products known as “Econol”, “Vectra”, “XYDAR”, “NOVACCURATE” Aramid short fibers such as poly-p-phenylene terephthalamide or copolymers thereof, or pulp thereof, poly-p-phenylene benzobisoxazole, poly-p-phenylene benzobis, known as “Kevlar”, “Alenka”, “Technola” Fully aromatic polymer short fibers such as thiazole or copolymers thereof, trade name “ High modulus polyethylene short fiber known as “Tekmylon”, “Dyneema”, “Spectra”, polyoxymethylene short fiber (polyacetal fiber) known as “Tenac SD” or its whisker, polyvinyl alcohol short fiber, etc. (4) Short metal fibers: Boron short fibers, titanium alloy short fibers, steel short fibers, aluminum alloy short fibers, etc. Carbon nanotubes are the new form of carbon after graphite / graphite, diamond, and fullerene, with carbon atoms bonded to hexagons. It is a new material with a structure in which the mesh is rounded into a cylindrical shape. There are single-walled nanotubes with a single cylinder (diameter of about 1 nanometer) and multi-walled nanotubes with several cylinders (diameters of several nanometers to several tens of nanometers). The length is several tens of micrometers, and the aspect ratio as a reinforcing fiber is a sufficient value. With regard to such carbon nanotubes, for example, research on mass synthesis technology is being promoted in the carbon-based high-functional material technology project of the Ministry of Economy, Trade and Industry, and nanotubes manufactured with the test apparatus of this project are available.

  As a constituent material of the matrix resin 802, a thermoplastic resin which is a general plastic having a certain degree of flexibility, a thermosetting resin such as rubber, or a thermally crosslinkable resin can be used. Specifically, for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyester elastomers using these as hard segments, polyolefins such as polyethylene and polypropylene, polyolefin elastomers, copolymer polyolefins using metallocene catalysts, polychlorinated Vinyl-based polymers such as vinyl, PVDC, PVDF, polyamides and polyamide elastomers (PAE) including nylon, polyimide, polystyrene, SEBS resin, polyurethane, polyurethane elastomer, ABS resin, acrylic resin, polyarylate, polycarbonate, polyoxymethylene (POM) ), Polyvinyl alcohol (PVA), fluororesin (ETFE, PFA, PTFE), ethylene-vinyl acetate Saponified product, ethylene-copoly-vinyl alcohol, ethylene vinyl acetate, carboxymethyl cellulose, methyl cellulose, cellulose acetate, vinyl polysulfone, liquid crystal polymer (LCP), polyethersulfone (PES), polyetheretherketone (PEEK), polyphenylene oxide In addition to various thermoplastic resins such as (PPO) and polyphenylene sulfide (PPS) and polymer derivatives thereof, thermosetting or cross-linkable resins such as vulcanized rubber, silicon resin, epoxy resin, and two-component reactive polyurethane resin are exemplified. . Furthermore, a polymer alloy containing any one of the above thermoplastic resins and thermosetting / crosslinking resins can also be used, and a resin solution in which a resin is dissolved in a solvent may be used as a molding material.

  Furthermore, in order to improve the adhesion between the short fibers 801 and the matrix resin 802, it is preferable to physically / physicochemically / chemically modify the surface structure. Examples of typical surface treatment (surface modification) include surface treatment with a silane coupling agent of glass fiber and surface treatment with a titanium coupling agent.

In addition to the two types of coupling agents, various surface treatment agents listed below can be used alone or in combination to improve the adhesion and adhesion between the fiber surface and the matrix resin.
(1) Higher fatty acids: stearic acid, oleic acid, etc. (2) Higher fatty acid esters, amides (3) Higher fatty acid metal salts: calcium stearate, magnesium, zinc, etc. (4) Higher alcohols (5) Various waxes: Low molecular weight Polyethylene, Polypropylene, etc. (6) Polar polyolefin: Maleic anhydride grafted polyolefin, acid-propylene copolymer, chlorosulfonated polyolefin, etc. When these surface modifiers are pre-treated on the fiber surface and then dispersed in the matrix resin In some cases, the short fiber and the matrix resin may be added at the same time. By combining the reinforced short fibers 801 and the matrix resin 802, an expert in the technical field can propose a highly effective surface modifier.

  In the present invention, a composite material in which the short fibers 801 are dispersed almost uniformly in the matrix resin 802 can be manufactured as follows.

  When the matrix resin 802 is a meltable thermoplastic resin, a method according to the purpose can be selected from known compounding methods. Examples of the kneader include a uniaxial and biaxial screw type kneader, a rubber roll, and a stone mill type kneader.

  In recent years, in situ polymerization has been favorably used as a method for mixing reinforcing fibers and a matrix resin. It can be particularly preferably used for fine reinforcing short fibers such as nanocarbon tubes.

  Specifically, the reinforcing short fibers 801 are in a state where the viscosity of the matrix resin (or its precursor: monomer, main component / curing agent of thermosetting resin) 3 is low even before the polymerization reaction of the matrix resin 802 or during the polymerization. Dispersion can greatly improve dispersibility. This method is particularly effective when the dispersibility is insufficient only by compounding in the molten state.

  In order to further improve the dispersibility of the short fibers 801 in the matrix resin 802, it is preferable to use the following ultrasonic shaking method. That is, in the process of mixing the reinforced short fibers and the matrix resin, ultrasonic vibration is applied to these mixtures for a certain period of time to loosen and expand the partially agglomerated reinforced short fibers while spreading the matrix resin. This is a method of infiltrating between short fibers.

  This method is applicable even when the matrix resin is in a molten state. However, more preferably, the matrix resin is dissolved in a suitable solvent, the reinforcing short fibers are mixed with the resin solution, and the resin solution is permeated and dispersed between the reinforcing short fibers by using a stirring blade or only by ultrasonic vibration. A method can be mentioned.

  In addition, when the matrix resin is produced by solution polymerization, a method of adding reinforcing short fibers and applying ultrasonic waves before, during, or after polymerization can be preferably carried out.

  By applying the method as described above, a composite material in which short fibers 801 are almost uniformly dispersed in a matrix resin 802 can be obtained. As shown in FIG. 1, a balloon in which short fibers are randomly dispersed in a balloon. Can be obtained. Moreover, the interfacial adhesive force between the reinforcing short fibers 801 and the matrix resin 802 is improved by dispersing almost uniformly in this way. Therefore, the reinforcing effect of the balloon becomes higher.

  After dispersing the reinforcing short fibers in the matrix resin solution, a composite in which the reinforcing short fibers 801 are well dispersed in the matrix resin 802 through extraction steps such as solvent removal, washing, drying, and granulation according to a normal process. Resin pellets or powder of the material can be obtained.

  When the matrix resin 802 is a thermoplastic resin, the resin pellet or powder of the composite material containing the short fibers 801 is prepared as described above, and then the balloon is formed by a conventional extrusion molding method or a rotational extrusion molding method described below. An original tube for molding can be produced. By pulling down during extrusion, an original tube in which short fibers 801 are oriented in the longitudinal direction can be produced. Moreover, the original tube which the short fiber 801 orientated to both the circumferential direction and the vertical direction can be produced by the rotation extrusion molding method. Then, the balloon 800 of the present invention can be manufactured by following the conventional biaxial stretch blow molding of the original tube.

  FIG. 2 is a schematic cross-sectional view showing a three-layer lamination example of the laminated tubular body coextrusion die 1 of the present invention.

  An extrusion die 1 of the present invention is for co-extrusion of a multilayer material to form a tubular body, and includes a die body 10, a mandrel 11 disposed through the die body 10, and a die. A die 13 disposed concentrically with the mandrel 11 at the downstream end in the extrusion direction of the main body 10, and at least one of the mandrel 11 and the die 13 is configured to be rotatable with the extrusion direction as an axial direction. It is a rotating circular die. In the present invention, either or both of the mandrel 11 and the die 13 may be rotated. However, in the following, an example in which only the mandrel 11 is simply rotated (hereinafter also referred to as a rotation point method in this specification) will be described as an example. I will explain to you.

  The die main body 10 shown in FIG. 2 has a polymer inlet 101a to 101c, a single joining portion 103 downstream in the extrusion direction, and expands into a tubular shape from each polymer inlet 101a to 101c, and then gradually shrinks to join. It has tubular branch paths 102 a to 102 c that communicate with the section 103 independently and merge at the merge section 103. The die body 10 having such a manifold structure inside can be configured by assembling a plurality of members 10a to 10d, for example.

  The mandrel 11 has a hollow structure having an axial internal gap 113, and a polymer contact portion (hereinafter also referred to as a rotation point) 111 having a cylindrical outer peripheral surface 111a projecting from the merging portion 103 toward the downstream end in the extrusion direction. Have

  The portion of the mandrel 11 that passes through the die body 10 and is connected to the drive unit 3 (FIG. 3) for rotating the mandrel 11 does not come into contact with the polymer flow except the point 111.

  The die 13 has a cylindrical space 130 formed by an inner peripheral surface 130 a having a diameter larger than that of the outer peripheral surface 111 a of the mandrel 11, and at least the upstream end 130 b in the extrusion direction of the cylindrical space 130 is the die body 10. It communicates with the merging portion end 103a with the same diameter.

  Due to the rotation point outer peripheral surface 111a of the mandrel 11 and the inner peripheral surface 130a of the die 13, the flow path 14 of the merged polymer consisting of voids formed in an annular cross section in the space 130 of the die 13, that is, a circular die. The dice-point polymer combined flow path is formed.

  The flow path 14 in the preferable die 13 of the present invention preferably has a tapered flow path 141 that gradually decreases in diameter at the merge portion 103 where the branch paths 102a to 102c merge while gradually decreasing in diameter.

  Specifically, the outer peripheral surface 111a of the mandrel 11 and / or the inner peripheral surface 130a of the die 13 are gradually reduced in diameter in the downstream direction from the joining portion 103 of the die body 10, that is, the mandrel tapered portion 111b and / or Alternatively, it is preferable that the taper channel 141 whose channel cross-sectional area is gradually reduced is formed by the die taper portion 130c and the extrusion channel 142 is downstream of the taper channel 141. The diameter of the extrusion channel 142 is approximately the inner diameter of the die 131, and has a size and shape close to the final target tubular body shape.

  The die 131 has its base 131 fixed to the die body 1 with a die holder 151.

  The shaft 112 of the mandrel 11 is held at the other end of the die body 10 by a shaft seal 152 that prevents polymer leakage.

  Next, a method for forming a laminated tubular body using the extrusion die of the present invention will be described. In addition, in each following figure, the same code | symbol as FIG. 1 or a mutual figure shows the same or an equivalent part, and the duplication description is abbreviate | omitted.

  FIG. 3 is a diagram schematically illustrating an extrusion line for producing a laminated tubular body using the die 1 of the above-described rotating point type aspect of the present invention, and is a three-layer laminated tube mainly made of a thermoplastic polymer material. A mode of manufacturing the will be described.

  For each device other than the die 1, commercial products can be used, and if necessary, the extruder cylinder, screw, etc. can be made of special metal materials / materials such as corrosion-resistant materials and wear-resistant materials. Forming is also within a range that can be appropriately changed. Moreover, what is necessary is just to select suitably specifications, such as the magnitude | size of an extruder or the capability of plasticization, according to the objective of tubular body production.

  In FIG. 3, the example of an aspect which manufactures a three-layer tubular body using the three extruders 2a, 2b, and 2c is shown. For example, when a three-layer laminated tubular body is manufactured by co-extrusion of three layers from two kinds of polymers, three extruders can be used, and each of the three layers can be formed from materials from separate extruders. When the inner and outer layers are made of the same material, two extruders can be used to supply the inner and outer layer materials from one extruder and the intermediate layer material from another extruder.

  Even when the inner and outer layer materials are formed of the same polymer, it is better to use three extruders and supply the material from separate extruders for each layer to distribute the desired amount of polymer and to form the inner and outer layers in the desired thickness. It is easy and easy to adjust.

  The materials in the extruders 2a to 2c are press-fitted into the die 1 from the polymer inlets 101a to 101c through the adapters 21a to 21c, respectively. Further, the gear pumps 22a, 22b, and 22c may or may not be provided, but it is preferable that the dimensional accuracy of the product is required.

  The base end of the shaft 112 of the mandrel 11 constituting the die 1 is connected to the drive unit 3.

  The polymer press-fitted into the die 1 is shaped into a laminated tubular body within the die 1 and is continuously extruded from the die 1. The laminated tubular body 4 extruded from the base 151 is solidified in the coagulation tank 5, continuously taken up by the take-up machine 6, measured by a laser outer diameter measuring device 61, and then taken up (or a cutting machine). 62 or the like.

  The method of the coagulation tank 5 differs depending on whether the material forming the extruded laminated tubular body is a thermoplastic polymer, a polymer solution using a solvent, or a thermosetting polymer, but solidification by cooling or solidification by chemicals. Alternatively, a solidification method by heating can be employed.

  In the case of a thermoplastic polymer, solidification by water cooling is common, and a water tank is used. When a water tank is used, an auxiliary device such as a low-pressure sizing or a vacuum water tank can be used to improve the roundness of the tubular body. Of these, the combined use of low-pressure sizing is preferable.

  Moreover, in the extrusion molding of a tubular body, a solid core material such as a copper wire, a liquid, a gas, or the like can be used as the core material 7.

  If the solid core material 7 is used, it is possible to easily maintain the inner diameter of the soft and easily deformed polymer that has been extruded from the base 151 and is shaped, but it is inexpensive and does not require the effort of removing the core metal. For this reason, air or nitrogen gas is often used for the core material.

  The core material supply method, the connection arrangement of the drive unit 3, and the method of transmitting rotation from the drive unit 3 to the rotation point 111 can be appropriately selected depending on the type of core material or the supply method.

  As a method of transmitting the rotation from the driving unit 3 to the rotation point 111, a normal direct coupling method or an offset coupling method can be adopted depending on the type of the core material.

  By the above-described rotary extrusion molding, the balloon material is extruded while at least most of the short fibers 801 are subjected to an external force in both the rotational direction and the long axis direction. Therefore, the obtained short fibers are impregnated in the original tube. 801 is oriented at least in the oblique direction with respect to the longitudinal direction of the original tube. By subjecting such an original tube to blow molding in a conventional manner, a balloon in which short fibers 801 are obliquely oriented as shown in FIG. 1 is obtained.

  On the other hand, when a thermosetting resin or a solution molding type resin is used as the matrix resin 802, the balloon 1 of the present invention can be manufactured using, for example, the balloon molding apparatus 9 shown in FIG.

  The balloon forming apparatus 9 includes an inner core 901 and a rotating shaft body 902. The inner core 901 has a shape corresponding to the shape of the balloon 1 to be manufactured. The balloon 1 is formed by applying a liquid composite material composed of the short fibers 2 and the matrix resin 3 to the outside of the inner core 901 and solidifying the material. The rotating shaft body 902 is provided coaxially with the inner core 901 and passes through the inner core 901.

  The inner core 901 needs to be removed from the balloon 1 without damaging the molded balloon 1. Therefore, as a material for forming the inner core 901, a water-soluble polymer (for example, polyvinyl alcohol resin) or a material that can be melted and removed at a temperature at which the molded balloon 1 is not damaged (for example, ethylene-vinyl acetate co-polymer). Polymer (EVA), polyethylene, polypropylene, etc.). Among these, the water-soluble polymer is particularly preferable.

  When the balloon 1 is manufactured using such a balloon molding apparatus 9, first, a thermosetting resin or a solution molding type liquid resin containing a necessary amount of reinforcing short fibers 801 is applied to the outer surface of the inner core 901. To do. In the case of adopting polyimide as a solution molding type resin, if the resin liquid is a polyamic acid, a subsequent ring closing reaction to the imide ring is necessary, so acetic anhydride containing a ring closing aid such as pyridine. Etc., the inner core 901 coated with the liquid resin is immersed for a predetermined time.

  Thereafter, as shown in FIG. 4, the balloon molding device 9 is held so that the long axis (center axis) direction of the inner core 902 coincides with the direction of gravity, and the long axis (center axis) of the inner core 901 is centered. Thus, the rotating shaft body 902 is rotated in the circumferential direction of the inner core 901. As a result, the short fibers 801 in the liquid resin applied to the inner core 901 are oriented in the major axis direction of the balloon by gravity, and are also oriented in the circumferential direction of the balloon by receiving the rotational force of the rotating shaft body 902. Note that the rotation speed and rotation time of the rotating shaft body 902 are appropriately set to such an extent that the short fibers 801 are sufficiently oriented in a predetermined direction.

Instead of gravity, after rotating the inner core 901 in the circumferential direction as described above and orienting the short fibers 801 in the circumferential direction of the balloon, the inner core 901 is centered on the axis perpendicular to the major axis direction. It is possible to orient the short fibers 801 in the major axis direction of the balloon by rotating.
After the short fibers 801 are oriented in a predetermined direction as described above, the balloon 1 is formed on the inner core 901 by solidifying the liquid resin applied to the outer surface of the inner core 901. Then, the inner core 901 is removed from the balloon 1 to obtain the balloon 1. When the inner core 901 is formed from a water-soluble polymer, the inner core 901 can be removed from the balloon 1 by washing with water.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples.

Example 1
<Preparation of fiber-blended polyamide elastomer resin>
Using a biaxial kneader, extrude and hot cut carbon short fibers (inner diameter: 7 μm, average length: 6 mm, aspect ratio: about 850) and polyamide elastomer resin surface-treated with a titanium coupling agent at 220 ° C. To obtain a compounded pellet. The blending amount of the short carbon fibers was 18% by weight with respect to the total amount of the polyamide elastomer. Although the fiber length was shortened by compounding, the average length was 400 to 500 μm and the aspect ratio was 60 or more.

<Extrusion of three-layer tube>
Using a rotary extrusion molding machine shown in FIG. 2, a balloon base tube was produced in which the outer layer and the inner layer were made of polyamide elastomer resin and the intermediate layer was made of the above-described fiber-blended polyamide elastomer resin. The above materials were respectively charged into three extruders, the extruder and die temperatures were set at a molding temperature of 200 ° C. ± 5 ° C., and press-fitted into the rotary die of the present invention to form a tubular body. Balloon source tube size: An outer diameter × inner diameter, 0.5 × 1.0 mm tube was molded. The dimensions of each layer were set such that outer diameter × inner diameter, outer layer thickness 0.1 mm, intermediate layer thickness 0.05 mm, and inner layer thickness 0.1 mm. The tube take-up speed at this time was 12 m / min, and the number of rotations at the time of extrusion was 100 rpm.
As described above, a tube having a very beautiful three-layer structure could be obtained.

<Balloon molding>
The obtained laminate tube was molded into a balloon (outer diameter: 3.0 mmφ) by a conventional biaxial stretch blow molding using a balloon molding die. This was assembled into a PTCA balloon catheter according to a standard method.

(Comparative Example 1)
For the purpose of comparison, a three-layer tube was formed in the same manner as in Example 1 above, except that a polyamide elastomer that was not compounded with carbon short fibers was used as the middle layer to produce a φ3.0 mm balloon. A PTCA balloon catheter was assembled.

<Balloon pressure resistance and properties>
When the balloon pressure resistance strength of Example 1 and Comparative Example 1 was measured, the balloon catheter of Comparative Example 1 had a pressure strength of 18 atmospheres, whereas the balloon catheter of Example 1 had 23 atmospheres or more. It withstands pressure. In addition, the flexibility of the balloon was sufficiently maintained. The pressure strength was measured by measuring the pressure at which the tube bursts by supplying the internal pressure from the nitrogen cylinder. Thereby, it was confirmed that the pressure resistance strength of the balloon was remarkably improved by the reinforcing effect by the short carbon fibers.

(Example 2)
<Preparation of fiber-containing polyimide resin>
Nanocarbon tubes (outer diameter: 7 μm, length: about 80 μm, multi-layer) were blended with thermoplastic polyimide [trade name: AURUM; Mitsui Toatsu Chemical Co., Ltd.] at 15% by weight. In the blending method, the nanocarbon tube was added and blended in the solution polymerization step of the polyamic acid which is a precursor of the polyimide, and after the formation of the polyimide ring, the resin was taken out as a resin blended with the nanocarbon tube in the polymerization stage.

An original tube for balloon molding having a wall thickness of 0.025 mm was produced by extrusion molding of this carbon nanotube-blended thermoplastic polyimide resin as usual. The die and tip cross-sectional area drawdown ratios during extrusion were 8: 1.
<Balloon molding>
The original tube obtained above was molded into a balloon (outer diameter: 3.0 mmφ) by a conventional biaxial stretch blow molding using a balloon molding die. This was assembled into a PTCA balloon catheter according to a standard method.

(Comparative Example 2)
For the purpose of comparison, except that a thermoplastic polyimide resin not containing carbon nanotubes was used, an original tube was formed in the same manner as in Example 2 above to produce a φ3.0 mm balloon, and a PTCA balloon A catheter was assembled.

<Balloon pressure resistance and properties>
When the balloon pressure resistance strength of Example 2 and Comparative Example 2 was measured, the balloon catheter of Comparative Example 2 had a pressure resistance of 25 atmospheres, whereas the balloon catheter of Example 2 had a pressure of 35 atmospheres or more. It withstands pressure. In addition, the flexibility of the balloon was sufficiently maintained. The pressure strength was measured by measuring the pressure at which the tube bursts by supplying the internal pressure from the nitrogen cylinder. Thereby, it was confirmed that the pressure-resistant strength of the balloon was remarkably improved by the reinforcing effect by the nanocarbon tube.

(Example 3)
<Preparation of fiber-containing polyurethane resin>
Polyurethane (trade name “Pandex”, manufactured by Dainippon Ink and Chemicals, Inc.) is dissolved in tetrahydrofuran at a concentration of 20%, and carbon short fibers (inner diameter: 7 μm, average length: 6 mm, aspect ratio: about) 850), and while stirring slowly at 30 ° C., using a commercially available ultrasonic oscillator (manufacturer: Ultrasonic Industry Co., Ltd., trade name: Model CM-121), the frequency is 38 KHz and the output is 600 W. The sound wave was irradiated for 60 minutes.

<Formation of balloon tube>
A metal wire having an outer diameter of 1 mm coated with polytetrafluoroethylene (PTFE) is immersed in a polyurethane solution containing short fibers subjected to ultrasonic shaking treatment as described above, and the metal wire is slowly pulled up at 60 ° C. Dry for 2 hours. After repeating this operation several times, the metal wire was pulled out to obtain a double-layer tube having a thickness of about 300 μm (PTFE layer thickness: 150 μm) and a length of about 200 mm.

<Balloon molding>
The obtained laminate tube was molded into a balloon (outer diameter: 3.0 mmφ) by a conventional biaxial stretch blow molding using a balloon molding die. This was assembled into a PTCA balloon catheter according to a standard method.

(Comparative Example 3)
For comparison purposes, a tube was formed in the same manner as in Example 3 except that a fiber-blended polyurethane that was not subjected to ultrasonic shaking treatment was used to produce a φ3.0 mm balloon, and a PTCA balloon catheter was assembled. It was.

<Balloon pressure resistance and properties>
When the balloon pressure resistance strength of Example 3 and Comparative Example 3 was measured, the balloon catheter of Comparative Example 3 had a pressure resistance of 18 atmospheres, whereas the balloon catheter of Example 3 had 23 atmospheres or more. It withstands pressure. In addition, the flexibility of the balloon was sufficiently maintained. The pressure strength was measured by measuring the pressure at which the tube bursts by supplying the internal pressure from the nitrogen cylinder. Thereby, it was confirmed that the pressure resistance strength of the balloon was remarkably improved by the reinforcing effect by the short carbon fibers.

800 Balloon 801, 801a, 801b Short fiber 802 Matrix resin

Claims (6)

In a balloon catheter having a balloon formed from a composite material composed of a high modulus short fiber for reinforcement and a matrix resin,
Each fiber of the high modulus short fiber is arranged in a non-aligned state in the balloon, and is distributed almost evenly in the balloon.
The composite catheter is characterized in that the high modulus short fibers are dispersed in the matrix resin by applying ultrasonic vibration when mixing the high modulus short fibers and the matrix material.   The balloon catheter according to claim 1, wherein at least most of the high modulus short fibers are oriented obliquely in a substantially constant direction with respect to the major axis direction of the balloon.   3. The balloon catheter according to claim 2, wherein a part of the high modulus short fiber is obliquely oriented in a direction different from the direction.   The high modulus short fiber is made of a composite material reinforced with at least one short fiber selected from the group consisting of carbon fiber, high modulus organic fiber, high modulus whisker, carbon nanotube, high modulus inorganic fiber or metal fiber. The balloon catheter in any one of 1-3.   The balloon catheter according to claim 4, wherein the high modulus short fiber is a nanocarbon tube.   The balloon catheter according to any one of claims 1 to 5, wherein the high modulus short fiber is subjected to a surface modification treatment for improving adhesion to the matrix material.

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