JP2000225196A - Catheter tube and producing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a high quality catheter tube enriched in safety and lubricity. SOLUTION: In this producing method, a metallic strand 5 is interwoven or coiled around the outer periphery of an inner thin layered tube 4, whose thickness is less than 50 μm, formed on a metallic core wire 10, the inner layered tube is heated to be melted, and the inner layered tube is chilled, so that many hollows are produced along the metallic strand 5 on the inner surface of the inner layered tube body 4. Therefore, a number of fine inequalities are formed on the inner surface of the inner layered tube body 4, so that a high quality catheter tube enriched in safety and lubricity, can be easily produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catheter tube used in a medical institution such as a hospital and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, a catheter tube used in a medical institution such as a hospital is inserted into a living body by using blood vessels, urethra and the like, and a distal end thereof reaches an affected part. In addition to the high safety and operability, excellent lubricating properties are required especially on the inner surface side because of the insertion of a wire and a guide wire.

[0003] As a conventional method for improving the lubricity of the inner surface of such a catheter tube, a tube itself is formed of a fluorine-based resin having low frictional resistance such as PTFE (polytetrafluoroethylene), or the inner surface of the tube is formed. There has been known a method of reducing frictional resistance by reducing the contact area with a guide wire or the like to be formed with minute unevenness to improve lubricity.

Among the methods for forming minute irregularities on the inner surface of the tube, for example, when extruding a thermoplastic resin, a resin extruded by vibrating an inner die provided in the melting passage is used. (Japanese Patent Publication No. 1-16653), a method of increasing the rigidity of a tube, and coating and baking a paint composed of a silicone resin and an inorganic powder on a metal braid to increase the rigidity of the tube. After forming the resin, a resin for forming the tube is applied and baked, and thereafter, the elongation below the yield point is applied to the metal braid to temporarily separate the tube from the coating film, thereby forming minute irregularities on the inner surface ( After coating and forming a synthetic resin material constituting a tube on a core wire having a large number of minute concave portions formed on the outer surface by embossing, How to draw out the core wire (JP 8-
No. 24342) has been proposed.

[0005]

However, the above-described method has the following drawbacks.

(1) In the method described in Japanese Patent Publication No. 1-16653, the inner mold is vibrated to cause uneven thickness and the like, so that unnecessary irregularities are formed on the outer surface of the tube. There is a drawback that the property is reduced. In particular, it is difficult to apply it to a small-diameter or thin-walled catheter tube that requires high dimensional stability.

(2) In the method described in Japanese Patent Publication No. 6-4301, the inorganic powder drops off from the metal braid and remains in the tube during the manufacturing process, which is caused when the catheter tube is inserted into the body. May be adversely affected.

(3) Further, in the method described in Japanese Patent Application Laid-Open No. H8-24342, it is difficult to pull out the embossed core wire because the core wire cuts into the inner surface of the tube. There is a risk that it will.

Accordingly, the present invention has been devised in order to effectively solve such a problem, and an object of the present invention is to easily obtain a safe and lubricating high-quality catheter tube. The present invention provides a novel method for manufacturing a catheter tube.

[0010]

In order to solve the above problems, the present invention is to form a thin inner tube made of a thermoplastic resin and having a thickness of 50 μm or less on a metal core wire, After braiding or coiling the metal wire around the circumference, this inner layer tube is heated and melted,
By cooling this, a large number of depressions are generated on the inner surface of the tube along the trajectory of the metal wire, and a large number of minute irregularities are formed on the inner surface.

As a result, a large number of minute irregularities can be easily formed on the inner surface of the inner layer tube. A high quality catheter tube rich in lubricity can be easily obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an overall view showing an embodiment of a catheter tube 1 according to the present invention, FIG. 2 is a partially enlarged sectional view showing a portion A in FIG. 1, and FIG. 3 is a sectional view taken along line XX in FIG. FIG.

As shown in the figure, this catheter tube 1 has a structure in which a highly flexible insertion tip 3 is integrally formed at the tip of a tube body 2 having high rigidity to be inserted into a living body. It has become.

As shown in FIGS. 2 and 3, the tube body 2 is made of a metal braid 6 made of a plurality of metal wires 5 from a thermoplastic resin such as a fluororesin over the entire outside of the inner tube 4. The rigidity of the inner tube 4 is increased to prevent inconveniences such as crushing and breaking, and to provide good torque transmission at the time of insertion into a living body.

As shown in the figure, the inner surface of the inner layer tube 4 has a plurality of irregularities formed over the entire surface thereof to reduce a contact area with an inserted guide wire (not shown). As a result, frictional resistance can be reduced when a guide wire or the like is inserted or removed.

More specifically, in the inner tube 4 of the present invention, the unevenness is that the inner surface in the vicinity of each metal element wire 5 is continuously depressed radially outward along the track. Are formed, a plurality of linear concave portions 7 are formed, and a space between the linear concave portions 7 remains as it is to form a convex portion 8.

A coating layer 9 is formed around the braid 6 so as to overlap with the inner tube 4 to prevent the inner tube 4 and the metal braid 6 from being exposed on the outer surface of the tube. In FIG. 1, reference numeral 11 denotes a catheter connector connected to an end of the tube main body 2 via a reinforcing tube 12.

Next, a method for manufacturing the catheter tube 1 of the present invention having such a configuration will be described.

First, as shown in FIGS. 2 and 3, a 50 μm-thick thermoplastic resin such as a fluororesin is coated on a metal core 10 made of a continuous wire such as a copper wire to form a thin inner layer. After the tube 4 is formed, a braid 6 composed of a metal wire 5 such as a SUS wire is formed on the outer surface of the inner tube 4.

The fluororesin used here includes:
Although not particularly limited, for example, polytetrafluoroethylene (PTFE), polyethylene tetrafluoroethylene (ETFE), polyfluoroalkoxy fluororesin (PFA), and tetrafluoroethylene hexafluoropropylene copolymer (FEP) , Vinylidene fluoride (PVD
It is preferable to use one excellent in lubricity such as F).
The metal core wire 10 is not particularly limited as long as it has a higher melting point than the resin constituting the inner tube 4 and can be easily pulled out from the inner tube 4. In addition to the copper wire, a gold or silver plated copper wire or the like can be used. The thickness of the inner tube 4 is limited to 50 μm or less by 50 μm.
This is because if the thickness is larger, the effect of forming the concavities and convexities by the metal element wire 5 is hindered as described later. Further, as the metal wire 5 constituting the braid 6, a platinum wire or the like can be used in addition to the SUS wire. However, if the metal wire 5 is excellent in corrosion resistance and has a higher melting point than the resin constituting the inner layer tube, these metals are particularly suitable. The cross-sectional shape is not limited, and may be an elliptical shape in addition to a true circular shape. In addition, the structure of the braid 6 is not particularly limited, and any structure may be used as long as the braid is woven in a constant pattern with an arbitrary tension from a braiding machine, a loom, or the like, or is wound in a coil shape at equal intervals.

Next, when the braid 6 is formed on the outer surface of the inner tube 4 in this manner, the entire inner tube 4 is heated to a temperature equal to or higher than its melting point to melt the resin, and then cooled to room temperature. Then, at the same time that the braid 6 cuts into the outer surface of the inner tube 4, a part of the resin constituting the inner surface of the inner tube 4 is depressed radially outward along the trajectory of each of the metal wires 5, 5. By leaving the portion as it is, fine irregularities are continuously formed on the entire inner surface of the inner tube 4.

Thereafter, the outer surface of the inner tube 4 is extruded with nylon resin so as to cover the braid 6 together with the inner tube 4 to form a coating layer 9 to form an inner surface having excellent safety and lubricity. The catheter tube 1 of the present invention can be easily obtained.

[0024]

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

(Example 1) PTFE, which is one of fluorine-based resins, was placed on a metal wire consisting of a 0.6 mm silver-plated copper wire.
To form an inner tube having a thickness of 30 μm, and a braid metal braid made of a SUS wire having a wire diameter of 40 μm was braided on the outer periphery of the tube. Next, this inner layer tube is
After heating the inner tube to a temperature at which TFE is melted by using an electric furnace, the inner tube is melted, and then cooled to room temperature. Thereafter, a nylon resin is further extruded outside the inner tube to form a coating layer. As shown in FIG. 2, a tube body having minute irregularities on the inner surface of the inner layer tube was prepared.

Example 2 An inner tube having a thickness of 30 μm was formed by coating PTFE on a metal wire made of a 0.6 mm silver-plated copper wire, and a platinum wire having a wire diameter of 40 μm was formed on the outer periphery of the tube by a braiding machine. Was coiled. Next, the inner tube is melted by heating the inner tube to a temperature at which the PTFE is melted using an electric furnace, and then cooled to room temperature. Thereafter, a nylon resin is further applied to the outside of the inner tube. The tube was extruded to form a coating layer, and a tube body having minute irregularities on the inner surface of the inner layer tube was prepared.

(Comparative Example) An inner tube having a thickness of 30 μm was formed by coating PTFE on a metal element wire made of a 0.6 mm silver-plated copper wire, and a wire diameter of 4 mm was formed on the outer periphery thereof by a braiding machine.
After braiding a metal wire made of a 0 μm SUS wire, a nylon resin is extruded to the outside of the inner tube without any heat treatment as in the above embodiment to form a coating layer, and the inner surface of the inner tube becomes a surface. One tube was made.

Then, the tips of the tube bodies of Examples 1 and 2 and Comparative Example thus formed were each made to have a diameter of 1.
The wire is wound around a 5 mm cylinder so that the tip comes out by 20 mm, and a wire whose surface is treated with PTFE is inserted so that the tip of the wire and the tip of the tube body coincide with each other, and the wire is inserted and removed with a stroke of 40 mm. Each load was measured, and the lubricity of the inner surface was evaluated based on the sawtooth waveform amplitude of the load.

As a result, the amplitude of the waveform was 102
gf, whereas in Examples 1 and 2, they were 46 gf and 52 gf, respectively, which were about 1/2 of the comparative example. Therefore, it was confirmed that Examples 1 and 2 could be more easily inserted and removed than Comparative Examples, and exhibited excellent lubricity.

[0030]

In summary, according to the present invention, minute irregularities can be easily and reliably formed on the inner surface of the tube, so that a catheter tube having excellent safety and lubricity can be easily obtained. Excellent effects such as the above can be exhibited.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of a catheter tube according to the present invention.

FIG. 2 is a partially enlarged sectional view showing a portion A in FIG.

FIG. 3 is a sectional view taken along line XX in FIG. 2;

FIG. 4 is a partially enlarged cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catheter tube 2 Tube body 3 Insertion tip part 4 Inner tube 5 Metal strand 6 Braid 7 Recess 8 Convex part 9 Coating layer 10 Metal core wire 11 Catheter connector part 12 Reinforcement tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideyuki Suzuki 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Power Systems Research Laboratory, Hitachi Cable, Ltd. (72) Inventor Hiroyuki Ito 5 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Electric Cable Co., Ltd. Hidaka Factory 1-1 (72) Inventor Kenji Asano 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Power Systems Research Laboratory, Hitachi Cable, Ltd.

Claims (2)

[Claims] 1. A thin inner tube made of a thermoplastic resin and having a thickness of 50 μm or less is formed on a metal core wire, and a metal wire is braided or coiled around the outer periphery of the inner tube. By heating and melting the tube and cooling it, a large number of dents are generated on the inner surface of the tube along the trajectory of the metal wire, and a large number of minute irregularities are formed on the inner surface. A method for producing a catheter tube. 2. It is made of a thermoplastic resin and has a thickness of 50 μm.
m or less on the outer surface or inside the thin inner tube,
A catheter tube comprising a braided metal wire or a coiled metal wire and having a large number of irregularities on an inner surface of an inner tube thereof.