JPH0670982A - Catheter tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To dissolve the trouble of the generation of the step difference related to the extrusion covering by the second outer layer, by forming the first outer layer through the extrusion molding to a prescribed outside diameter, in the constitution having a body part which is formed by covering an inner layer, reinforcing layer and the first outer layer by the second outer layer. CONSTITUTION:In the manufacture of a catheter tube 9, an inner layer 4 made of the resin such as polyamide elastormer and polyurethane elastomer is extrusion-molded on a core member which is formed by extrusion-coating a molding releasing layer 2 on a copper wire. Then, on the periphery of the inner layer 4, a reinforcing layer 5 which is formed by braiding the high strength fiber, preferably the thin metal wire is formed, and then extrusion-coated by the first outer layer 6. The outer layer 6 is shaped to the outside diameter less than the value in addition of 0.1mm to the outside diameter of the reinforcing layer 5 in the original installation state. Then, after the molding releasing layer 2 is exposed by removing a part of the part L2 after the removal of the reinforcing layer 5, extrusion-coating with the second outer layer is carried out, and the shaped article is cut to a prescribed length and released from the core member, to obtain a finished article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter tube used by being inserted into a blood vessel for the purpose of administering a therapeutic agent directly to a lesion in the body, injecting a contrast agent for finding an abnormal portion of a blood vessel, and the like. It relates to a manufacturing method.

[0002]

2. Description of the Related Art It is well known that a catheter tube has been used to administer and inject a therapeutic agent, a contrast agent or the like into a lesion in the body. Since this catheter tube is used by inserting it into a target site while controlling the distal end located inside the blood vessel or organ by manipulating the part remaining outside the body, some ingenuity is required in terms of safety.

That is, the pressure resistance is high enough to withstand the injection of therapeutic agents and contrast agents, the followability of the tip to follow the operation of the remaining part outside the body, and the flexibility to prevent damage to the inner wall of the blood vessel. Need to meet at the same time. An example of a device for satisfying these characteristics is disclosed in Japanese Patent Publication No. 2-30691. The catheter tube described in the above publication is a catheter tube in which a main body portion and a distal end portion are integrally formed in the axial direction, and the main body portion has a reinforcing layer made of a metal wire such as stainless steel wire, It is of a type that does not have a reinforcing layer at its tip. With such a configuration, it becomes possible to provide the tip end with flexibility. In addition, according to the above publication, this catheter tube can be manufactured by a continuous manufacturing method.

Examples of further improved flexibility of the catheter tube disclosed in the above publication include those disclosed in Japanese Patent Publication No. 2-30265 and Japanese Patent Publication No. 3-32376. In the catheter tubes shown in these publications, a resin material having low flexibility (small flexibility) is used as an inner layer, and a resin material having high flexibility (large flexibility) is used as an outer layer. , The tip is formed only by the outer layer. With these measures, the flexibility of the tip portion of the catheter tube is considerably improved.

In addition to the above-mentioned catheter tube, there is also known one in which, for example, a highly flexible resin is adhered to the end surface of the distal end portion of the catheter tube with an adhesive or the like.

[0006]

However, the above-mentioned conventional catheter tube has the following problems. First, as for the catheter tube, it is desirable that the end face of the distal end portion is particularly excellent in flexibility so that the inner wall of the blood vessel is not damaged during insertion into the blood vessel.
-30265 and JP-B-3-32376 show that the outer layer has a flexibility of at most 1000 kg.
Since there was a limit of about / cm ^2, it was not so effective in preventing damage to the inner wall of the blood vessel by the end face of the tip. The reason why the flexibility of the outer layer is 1000 kg / cm ² is that when soft outer layer resin is used, air bubbles are generated from the reinforcing layer by simply bonding both ends of the reinforcing layer made of a metal wire to the inner layer. It is thought that this is because many defects occur. Further, it is considered that, due to the continuous manufacturing method, the deflection of the outer diameter of the reinforcing layer becomes sensitive, and a step may be formed at the boundary between the main body portion and the tip end portion, resulting in inconvenience of frequent defects.

On the other hand, a catheter tube made by adhering a highly flexible resin to the end surface of the distal end has no merit on the flexibility of the distal end and has an advantage that it can sufficiently prevent damage to blood vessels. In some cases, the outer diameter was increased by that much due to variations in adhesion, or the tip of the adhesive that had adhered inside the blood vessel fell off, causing an accident.

In view of the above circumstances, the inventors of the present invention have conducted various studies to obtain a catheter tube having a sufficiently flexible distal end by a continuous manufacturing method which is an integral molding method and has high productivity. I found it.

[0009]

That is, a catheter tube according to the present invention comprises an inner layer, a first outer layer, and a reinforcing layer formed between the inner layer and the first outer layer covered with a second outer layer. A catheter tube formed by integrally forming a main body portion and a distal end portion formed of only the second outer layer and having the same inner diameter as the main body portion,
The first outer layer is characterized by being extruded to have an outer diameter equal to or less than a value obtained by adding 0.1 mm to the outer diameter of the inner layer with the reinforcing layer provided. Further, in this case, the effect of the present invention becomes more clear when the bending elastic modulus of the second outer layer is less than 1000 kg / cm ² .

Further, in the method for manufacturing a catheter tube according to the present invention, the main body part is formed by covering the inner layer, the first outer layer, and the reinforcing layer formed between the inner layer and the first outer layer with the second outer layer. And a method of manufacturing a catheter tube in which a tip portion that is formed only by the second outer layer and that has the same inner diameter as the main body portion is integrally formed, after extruding the inner layer onto a core material. , A reinforcing layer is continuously formed on the inner layer with a predetermined interval so that a portion having a high braid density and a portion having a thin braid density alternately appear, and the portion having a low braid density of the reinforcing layer is cut off to remove the reinforcing layer. After forming the non-existing portion, the first outer layer is extrusion-coated to an outer diameter equal to or less than a value obtained by adding 0.1 mm to the outer diameter of the inner layer with the reinforcing layer provided, and then the first outer layer. And the inner layer is partially removed by the part without the reinforcement layer. And, and further the second outer layer extrusion coated on them, after cutting them in predetermined positions, characterized by prepared by pulling out the core. At this time, the bending elastic modulus of the second outer layer is 10
If it is less than 00 kg / cm ² , the effect of the present invention becomes clearer.

[0011]

According to the above-mentioned structure, the outer diameter of the first outer layer coated is improved in accuracy, and it is believed that the problems associated with the extrusion coating of the second outer layer are eliminated.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described in more detail below with reference to FIGS. In this example, first, as shown in FIG. 1, a release layer 2 made of ETFE (ethylene / tetrafluoroethylene copolymer resin) was extrusion-coated on a copper wire 1 having a diameter of 0.8 mm to give an outer diameter of 1 A core material 3 of 0.1 mm was obtained. Here, when the release layer is not used, the diameter is 1.
A 1 mm copper wire, a tin-plated copper wire, a nickel-plated copper wire, or the like may be used. The release layer may be made of a fluororesin other than ETFE, such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin), FEP (tetrafluoroethylene / hexafluoropropylene copolymer resin). You may coat. Of course, the fluororesin may be coated by a method other than extrusion molding.

Next, an inner layer 4 having an outer diameter of 1.
It was extruded to 4 mm. Examples of the resin used for the inner layer include polyamide elastomer, polyurethane elastomer, polyester elastomer, polyolefin elastomer and the like. Since those having various hardnesses are commercially available, these may be used. In this example, 100 parts by weight of polyamide 12-based polyamide elastomer having a Shore A hardness of 55 degrees was kneaded with 80 parts by weight of bismuth oxide.

Further, a reinforcing layer 5 was formed around them. The reinforcing layer is formed by braiding a high-strength fiber, preferably a thin wire of a metal wire. The metal wires may be in a multi-end form in which several wires are aligned and braided. In this example, two stainless steel wires having a diameter of 0.05 mm were drawn and aligned, and the reinforcing layer was formed by braiding at a braid density of 5. At this time, by changing the speed of the carrier, a portion with a high braid density (L ₁ ) and a portion with a low braid density (L ₂ ) are created, and the portion with a low braid density is cut and removed as shown in FIG. One end (P) of the portion was pressed and fixed with a heated iron. A portion with a reinforcing layer and a portion without a reinforcing layer were formed at 500 places, that is, for 500 products. Of these, 250 pieces were sent to the next step as the ones to be used in the examples. The remaining 250 pieces were manufactured by the conventional method for comparison. The braided portion may be fixed before removing the portion where the braid density is low, or may be fixed at the same time as the braiding. At this time, the outer diameter with the reinforcing layer provided was 1.60 mm.

Next, as shown in FIG. 3, the first outer layer 6 was extrusion-coated. The outer diameter of the coating of the first outer layer must be less than or equal to the value obtained by adding 0.1 mm to the outer diameter of the state in which the reinforcing layer is provided. When the value exceeds the above-mentioned value, the fixing of the reinforcing layer 5 to the inner layer 4 becomes insufficient, which is not preferable, and undesirably increases the outer diameter of the product. The extrusion temperature of the first outer layer is a temperature above the melting point of the inner layer,
The temperature is preferably about the same as the extrusion temperature of the inner layer. As the resin used as the first outer layer, any resin can be used as long as the extrusion temperature is equal to or higher than the melting point of the inner layer, preferably the temperature substantially equal to the extrusion temperature of the inner layer. In this example, a resin similar to the resin for the inner layer was extruded to an outer diameter of 1.55 mm at the same temperature to form the first outer layer.

Next, as shown in FIG. 4, the first outer layer 6 and the inner layer 4 are partially removed at a portion (L ₂ ) having no reinforcing layer,
The release layer 2 was exposed. As a removing method, there is a method using a cutter or fusing, and either method may be used. As the end surface for removal, it is preferable to cut diagonally or cut by cutting a part rather than cutting vertically, and the contact area between the second outer layer described below and the first outer layer and inner layer is large. Therefore, the adhesion is improved, which is preferable. In this example, a cutter was used to obliquely cut.

Next, as shown in FIG. 5, the second outer layer 7
Was extrusion coated. As the resin used as the second outer layer, the same type of resin is used in order to improve the adhesion to the first outer layer. Further, in order to obtain a catheter tube having a sufficiently flexible tip, the bending elastic modulus of the second outer layer needs to be less than 1000 kg / cm ² . With an elastic modulus of 1000 kg / cm ² or more,
Practically, it is not preferable because it has no blood vessel damage preventing effect. In this example, 100 parts by weight of a grade having a flexural modulus of 250 kg / cm ² of a polyamide elastomer of the same type as the inner layer,
A kneaded mixture of 50 parts by weight of bismuth oxide was used and extruded to an outer diameter of 1.6 mm. At this time, defects such as foaming from the reinforcing layer, generation of a step at the boundary between the second outer layer and the first outer layer and inner layer, and foaming were not observed, and all good products were obtained. Usually, this is cut into a predetermined length, and the finished product is obtained by pulling out the core material. However, in this embodiment, it is more preferable that the surface has a less sticky feeling. The third outer layer 8 is extruded to an outer diameter of 1.7 mm with a polyamide elastomer having a rate of 1200 kg / cm ² , and then the core material is cut out and the core material is pulled out.
A catheter tube 9 (completed product) in which ₁ ) and the tip (X ₂ ) were integrally formed was obtained. (Shown in Figure 6)

As a comparative example, the other end of the reinforcing layer of the remaining 250 intermediate products divided in the above was fixed with an adhesive basically according to JP-B-2-30691. A polyamide elastomer of the same type as the inner layer was kneaded with 50 parts by weight of bismuth oxide in 100 parts by weight of a flexural modulus of 250 kg / cm ² , and the outer diameter was 1.6 m.
Extruded with m. At this time, there are two foams from the reinforcing layer,
The number of step differences at the boundary between the first outer layer and the portion where the inner layer was removed was very large at 40 points, and three foamed points were also found.

[0019]

As described in detail above, according to the present invention, it is possible to obtain a catheter tube having a sufficiently flexible distal end portion by an integral molding method and a continuous manufacturing method with high productivity. Further, if the third outer layer is further formed, there is no sticky feeling, and it is practically excellent in safety and usability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of a catheter tube according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of a catheter tube according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the manufacturing process of the catheter tube according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the process of manufacturing a catheter tube according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing the manufacturing process of the catheter tube according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view of a catheter tube according to an embodiment of the present invention.

[Explanation of symbols]

 1 Copper Wire 2 Release Layer 3 Core Material 4 Inner Layer 5 Reinforcement Layer 6 First Outer Layer 7 Second Outer Layer 8 Third Outer Layer 9 Catheter Tube

Claims (4)

[Claims] 1. A main body formed by covering an inner layer, a first outer layer, and a reinforcing layer formed between the inner layer and the first outer layer with a second outer layer, and only the second outer layer. In the catheter tube integrally formed with the body portion and the distal end portion having the same inner diameter, the first outer layer has an outer diameter of 0.1 mm while the inner layer is provided with the reinforcing layer. A catheter tube characterized by being extruded to have an outer diameter equal to or less than the value obtained by adding. 2. The flexural modulus of the second outer layer is 1000.
The catheter tube according to claim 1, which is less than kg / cm ² . 3. A main body formed by covering an inner layer, a first outer layer, and a reinforcing layer formed between the inner layer and the first outer layer with a second outer layer, and only the second outer layer. In the method for manufacturing a catheter tube in which the body portion and a tip portion having the same inner diameter are integrally formed, an inner layer is extruded on a core material and then braided on the inner layer at a predetermined interval. The reinforcing layer is continuously formed so that the high density portion and the thin portion alternately appear, and the portion without the braiding density of the reinforcing layer is cut and removed to form a portion without the reinforcing layer. The outer layer is extrusion-coated to an outer diameter equal to or less than a value obtained by adding 0.1 mm to the outer diameter of the inner layer with the reinforcing layer provided, and then the first outer layer and the inner layer are covered with a portion having no reinforcing layer. Partly removed and then extrusion coated with a second outer layer on them, which A method for manufacturing a catheter tube, characterized in that the core material is manufactured by cutting them at a predetermined position. 4. The flexural modulus of the second outer layer is 1000.
It is less than kg / cm < ² >, The manufacturing method of the catheter tube of Claim 3 characterized by the above-mentioned.