JP2000033122A - Ptfe-lined composite catheter tube and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve lubricability by widening an inside diameter, and to improve contrast making property with thinning an external shape by forming an PTFE-lined composite catheter tube of a pure PTFE tube obtained by applying, baking and sintering a polytetrafluoroethylene (PTFE) resin dispersing liquid and a contract medium blending PTFE layer by applying, baking and sintering a contrast medium blending PTFE dispersing liquid on it. SOLUTION: A pure PTFE tube 2 is made by repeatedly applying, baking and sintering a PTFE dispersing liquid one time on a silver plating copper wire being a mandrel. Next, a contrast medium blending PTFE layer 3 is made by repeatedly applying, baking and sintering a barium sulfate blending PTFE dispersing liquid two times on it as a contrast medium to make a contrast medium blending PTFE overcoat pure PTFE tube. Next, an inner layer PTFE composite catheter tube is obtained by extruding/covering a polyamide elastomer layer 4 on this contrast medium blending PTFE overcoat pure PTFE tube by an extruder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an inner layer PTFE composite catheter tube and a method for producing the same. More specifically, the present invention relates to an inner-layer PTFE composite catheter tube suitable for a small-diameter microcatheter having excellent contrast and a method for producing the same.

[0002]

2. Description of the Related Art Catheters are widely used as medical devices for directly examining the trachea, stomach, intestine and the like. More recently,
In order to reduce the physical burden and time burden on patients, catheters have been used not only as diagnostic medical devices but also as therapeutic devices.

[0003] The catheter here comprises a catheter tube and an operation section. The intermediate layer of the catheter tube is provided with a braided layer formed by spirally winding or braiding a metal wire or a non-metallic striated body as needed to improve operability.

[0004] In such a catheter tube used as a medical examination and treatment device, the passage of a medicine and the operation member of a microtherapy device are inserted through the tube.

For this reason, it is required that the inner diameter of a catheter tube used as a treatment device be as large as possible and the inner layer be as lubricious as possible.

[0006] In addition, a catheter used as a treatment device is required to be able to monitor the position of the catheter when the catheter is inserted into the body. For this reason, a catheter used also as a treatment device is required to be negative when transmitted through X-rays.

[0007] As such a catheter tube having a negative and lubricating property, a fluorine resin having a good lubricating property in an inner layer,
For example, polytetrafluoroethylene resin (hereinafter, PTF)
E), and an intermediate blade layer is provided thereon if necessary, and the outer coating is made of a polyamide resin, a polyamide elastomer, a polyurethane resin, a polyurethane elastomer, etc. having excellent mechanical properties and end workability. Composite plastic catheter tubes have been used.

In a composite plastic catheter tube in which the inner layer is made of a PTFE tube and the outer layer is made of a polyamide resin, polyamide elastomer, polyurethane resin, polyurethane elastomer, etc., the outer diameter is required to be small, which is a unique requirement of the catheter tube. In addition, there is a demand that the inner diameter be made as large as possible from the viewpoint of the penetrability of the microtherapy instrument inserted through the tube. For this reason, the inner PTFE layer is made extremely thin.

[0009]

However, a composite plastic catheter tube having an inner PTFE tube on the inside, an intermediate braid layer on the middle, and an outer coating layer on the outside, particularly a small-diameter inner PTFE composite catheter tube having excellent contrast properties. It is difficult to balance the reduction in diameter with the contrast.

(1) A PTFE layer having an extremely thin PTFE layer
Since PTFE is a resin having a super-hardness, a high softening point and a high melt viscosity, its extrusion moldability is extremely poor. As a result, an extremely thin PTFE tube is continuously extruded as a tube by an extruder. Extremely difficult. With the current manufacturing technology, it is not possible to manufacture a PTFE tube having a thickness of 100 μm or less.

For this reason, since the inner layer PTFE tube cannot be made thinner in the inner layer PTFE composite catheter tube, it is necessary to make the outer coating layer thinner to reduce the outer diameter.

Now, in the inner layer PTFE composite catheter tube having an outer coating layer containing a contrast agent, when the outer coating layer is made thinner, the total amount of the contrast agent decreases,
As a result, the contrast is reduced.

A first method of improving the contrast of a catheter tube having a poor contrast is to form a metal tip for contrast at the distal end thereof. However, the work of embedding the metal tip for contrast is complicated and requires precision processing, so that there is a problem that a great increase in cost is caused.

A second method of improving the contrast is to use a platinum wire or the like having excellent contrast as the element wire of the blade layer.
However, this method uses an expensive platinum wire or the like, resulting in a significant cost increase.Moreover, the platinum wire has a lower mechanical strength than a stainless wire or the like. There is a drawback that frequently occurs.

[0015] A third method of improving contrast is a method in which a contrast agent is blended into the inner layer PTFE tube. However, the contrast agent-containing PTFE resin has a further problem that it becomes much harder, has a higher softening point, and has a higher melt viscosity, and as a result, it becomes more difficult to produce an extremely thin PTFE tube.

The present invention has been made in view of such a point, and an object of the present invention is to overcome the above-mentioned disadvantages of the prior art, and to manufacture an extremely thin PTFE tube at the time of manufacturing. It is an object of the present invention to provide an inner-layer PTFE composite catheter tube having a large inner diameter, excellent lubricity, a small outer diameter, and excellent contrast, and a method for producing the same.

[0017]

The gist of the present invention lies in the following two points.

(1) An inner-layer PTFE composite catheter tube in which an outer resin layer is coated directly or via a blade layer on an inner-layer polytetrafluoroethylene resin tube layer, wherein the inner-layer polytetrafluoroethylene resin tube is made of polytetrafluoroethylene. Pure PTFE obtained by applying, baking and sintering an ethylene resin dispersion
Tube and PTF containing contrast agent on the pure PTFE tube
E-dispersed liquid, baked, and sintered to obtain a PTFE layer containing a contrast agent.
An inner layer PTFE composite catheter tube, which is an overcoated pure PTFE tube.

(2) A pure PTFE tube is prepared by applying a polytetrafluoroethylene resin dispersion on a mandrel rod, baking and sintering the pure PTFE tube.
The contrast agent-containing PTFE dispersion is applied onto a tube, baked, and sintered to form a contrast agent-containing PTFE overcoated pure PTFE tube, and then the contrast agent-containing PT
A method for manufacturing an inner-layer PTFE composite catheter tube, comprising providing an outer coating layer on a FE overcoated pure PTFE tube, and finally pulling out the mandrel bar.

That is, the characteristics of the inner layer PTFE composite catheter tube of the present invention and the manufacturing method thereof are as follows.
An innermost tube made of a pure PTFE resin tube obtained by applying, baking, and sintering a PTFE resin dispersion as an E resin tube, and then applying, baking, and baking a PTFE resin dispersion containing a contrast agent. By forming an intermediate inner layer from the contrast agent-containing PTFE resin tube obtained by tying, and then providing a blade layer thereon as necessary, and further providing an outer coating layer on the upper layer, the thickness is thin and An object of the present invention is to obtain an inner layer PTFE composite catheter tube having excellent lubricity and excellent contrast.

The inner layer PTFE composite catheter tube of the present invention is a two-layer PTFE composite tube comprising an innermost layer of a pure PTFE resin tube and an intermediate inner layer of a PTFE resin tube containing a contrast agent.
The use of the TFE resin tube also exerts the following secondary effects.

The first secondary effect is that PTFE containing a contrast agent is used.
The abrasion resistance of the resin tube is improved. As a result, even if the metal layer is spirally wound or braided under a large tension on the PTFE resin tube containing the contrast agent, even if the blade layer is provided, the inner layer PTFE resin tube is damaged. Nothing.

The second side effect is that PTFE containing a contrast agent is used.
The surface energy of the resin tube is improved, and as a result, the adhesion to the blade layer and the outer coating layer can be improved.

[0024]

Next, an embodiment of the inner layer PTFE composite catheter tube of the present invention and a method for producing the same will be described.

In the present invention, the mandrel rod includes a metal wire, an alloy wire, and a plated metal wire. Examples of the metal wire include a copper wire, an aluminum wire, a silver wire, and a gold wire. In consideration of the low cost and safety to the human body, a silver plated copper wire or the like is appropriate as the mandrel bar.

The PTFE resin dispersion may be either an aqueous dispersion or a solvent dispersion, but is preferably an aqueous dispersion from the viewpoint of fire prevention and working environment.

The particle size and concentration of the PTFE resin particles are determined appropriately. Further, a dispersion stabilizer, a viscosity adjuster, a surfactant, a colorant, a pH adjuster, and the like can be appropriately compounded in the dispersion. It is desirable that the surfactant leaks a hydrophilic group such as an oxyethylene group.

The blade layer is provided as a layer for imparting rotational torque transmission, pressure resistance, elasticity, flexibility and the like to the catheter tube. The outer diameter of this blade is φ
There is a 30 to 70 μm stainless wire or the like.

In the present invention, the contrast agent may be any radiopaque powder substance that can be used medically.
It is not specified. Examples of such typical contrast agents include metal compounds such as barium sulfate and bismuth oxide,
Platinum powder and the like. The particle diameter of these contrast agent powders is 0.1 to 10 times, preferably about 0.3 to 5 times the particle diameter of the PTFE resin. That is, when the contrast agent powder is 0.1 times or less, the sinterability of the PTFE resin is hindered. On the contrary, when the contrast agent powder is 10 times or more, the stability of the PTFE resin dispersion liquid containing the contrast agent deteriorates.

[0030]

Next, examples of the inner layer PTFE composite catheter tube of the present invention and a method for producing the same will be described together with comparative examples.

The PTFE resin particles in the aqueous PTFE dispersion have an average particle diameter of 0.35 mm. The PTFE resin particles used in the ram extrusion method had an average particle diameter of φ4.
It is 50mm.

(Example 1) Outer diameter φ to be a mandrel rod
On a 0.55 mm silver-plated copper wire, add 1 aqueous PTFE dispersion
A pure PTFE tube having a thickness of 10 μm was prepared by repeatedly applying, baking, and sintering.

Next, an aqueous PTFE dispersion containing 20% barium sulfate as a contrast agent was placed on the pure PTFE tube.
By repeatedly applying, baking, and sintering, a PTFE overcoated pure PTFE tube having a thickness of 25 μm and an outer diameter of φ0.6 mm was prepared.

Next, an inner layer PTFE composite catheter tube having an outer diameter of 1.00 mm was obtained by extruding and coating a polyamide elastomer on the PTFE overcoated pure PTFE tube containing the contrast agent thus obtained by an extruder. Was.

Finally, the inner layer PTFE of Example 1 was cut off by cutting off the inner layer PTFE composite catheter tube at both ends, and then pulling out the silver-plated copper wire of the mandrel rod.
A composite catheter tube was obtained.

FIG. 1 is a cross-sectional view of the inner-layer PTFE composite catheter tube of Example 1 thus obtained.

In FIG. 1, 2 is a pure PTFE tube,
3 is a PTFE layer containing a contrast agent, and 4 is a polyamide elastomer layer.

(Example 2) Outer diameter φ to be a mandrel rod
On a 0.55 mm silver-plated copper wire, add 1 aqueous PTFE dispersion
A pure PTFE tube having a thickness of 10 μm was prepared by repeatedly applying, baking, and sintering.

Next, an aqueous dispersion of PTFE containing 20% barium sulfate as a contrast agent was placed on the pure PTFE tube.
By repeatedly applying, baking, and sintering, a PTFE overcoated pure PTFE tube having a thickness of 18 μm and an outer diameter of φ0.6 mm was prepared.

Next, an aqueous dispersion of PTFE containing 35% of barium sulfate as a contrast agent was repeatedly applied to the PTFE overcoated pure PTFE tube once, baked, and sintered to form a contrast medium having a thickness of 25 μm. A PTFE overcoated pure PTFE tube containing the agent was prepared.

Finally, the inner layer PTFE of Example 2 was removed by cutting off the inner layer PTFE composite catheter tube at both ends and then pulling out the silver-plated copper wire of the mandrel rod.
A composite catheter tube was obtained.

(Comparative Example 1) Outer diameter φ to be a mandrel bar
PTFE particles containing 5% of barium sulfate as a contrast agent were extruded on a 0.55 mm silver-plated copper wire by ram extrusion to obtain an outer diameter of φ.
A 0.75 mm PTFE tube containing a contrast agent was prepared.

Next, a polyamide elastomer having an outer diameter of φ1.2 was placed on the PTFE tube containing the contrast agent using an extruder.
A 0 mm inner layer PTFE composite catheter tube was obtained.

Finally, the inner layer PTFE of Comparative Example 1 was cut off by cutting off the inner layer PTFE composite catheter tube at both ends and then pulling out the silver-plated copper wire of the mandrel rod.
A composite catheter tube was obtained.

(Comparative Example 2) Outer diameter φ to be a mandrel bar
We tried ram extrusion of PTFE particles containing 10% of barium sulfate as a contrast agent on a 0.55 mm silver-plated copper wire, but the extrudability was poor due to the addition of 10% of barium sulfate. As a result, PTFE tubes containing a contrast agent were used. Was not obtained.

(Characteristic Test Method) Next, a characteristic test was performed on the inner-layer PTFE composite catheter tubes of Examples 1 and 2 and Comparative Examples 1 and 2 thus obtained.

A. The contrast was tested by the contrast test method for the contrast catheter tube. b. Adhesion between Inner Layer and Outer Layer The inner layer PTFE composite catheter tubes of Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to 90-degree bending resistance 20 times, and then the adhesion between the inner layer and the outer layer was examined. The results were indicated by ○ when there was no abnormality in the adhesion between the inner layer and the outer layer, and indicated by x when the inner layer and the outer layer were separated.

(Characteristic test results) Table 1 shows the characteristic test results.

[0049]

[Table 1]

As can be seen from Table 1, the inner-layer PTFE composite catheter tubes of Comparative Examples 1 and 2 had no drawback, and had a problem that the inner layer and the outer layer were separated.

On the other hand, the inner layer PT of Examples 1 and 2
The FE composite catheter tube had excellent contrast and the inner layer and the outer layer were completely adhered to each other, and as a result, the reliability was significantly improved.

Although the example without the blade layer has been described in the embodiment, the same result can be obtained with the blade layer.

[0053]

According to the inner layer PTFE composite catheter tube of the present invention and the method for producing the same, an inner layer PTFE composite catheter tube having excellent contrast properties and having an inner layer and an outer layer completely adhered to each other can be obtained, and is medically useful. It is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an inner-layer PTFE composite catheter tube according to Example 1 of the present invention.

[Explanation of symbols]

 2 Pure PTFE tube 3 PTFE layer containing contrast agent 4 Polyamide elastomer layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiharu Goto 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in Power Systems Research Laboratories, Hitachi Cable, Ltd. 4C081 AC08 BB03 BB05 BB09 CA131 CA132 CA212 CA232 CB052 CF112 CF21 CF22 CG07 DA03 DA13 DB02 DC03 DC04 DC06 DC13 EA02 EA03 EA04

Claims (4)

[Claims] 1. An inner-layer PTFE composite catheter tube in which an outer resin layer is coated directly or via a blade layer on an inner-layer polytetrafluoroethylene resin tube layer, wherein the inner-layer polytetrafluoroethylene resin tube is made of polytetrafluoroethylene. A pure PTFE tube obtained by applying, baking, and sintering a resin dispersion, and a contrast agent-containing PTFE layer obtained by applying, baking, and sintering a PTFE dispersion containing a contrast agent on the pure PTFE tube; An inner layer PTFE composite catheter tube, which is a PTFE overcoated pure PTFE tube containing a contrast agent comprising: 2. The inner layer PTFE composite catheter tube according to claim 1, wherein the contrast agent is a metal compound such as barium sulfate or bismuth oxide or platinum powder. 3. (Particle size of PTFE resin in polytetrafluoroethylene resin dispersion) and (particle size of metal compound)
The inner layer PTFE composite catheter tube according to claim 1, wherein the ratio is 1: 0.1 to 1:10. 4. A pure PTFE tube is prepared by coating, baking and sintering a polytetrafluoroethylene resin dispersion on a mandrel rod, and then coating and baking a PTFE dispersion containing a contrast agent on the pure PTFE tube. And sintering to form a contrast agent-containing PTFE overcoated pure PTFE tube, thereafter providing an outer coating layer on the contrast agent-containing PTFE overcoated pure PTFE tube, and finally pulling out the mandrel bar. For producing an inner layer PTFE composite catheter tube.