JP4269456B2 - Method for manufacturing catheter tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a catheter tube used in a medical institution such as a hospital.
[0002]
[Prior art]
Conventionally, in a medical institution such as a hospital, a tube-like medical instrument called a catheter tube is used to inject a drug solution or a contrast medium from outside into a predetermined part of a patient's living body, or to take out a body fluid or the like in the living body. It is used.
[0003]
In general, since this catheter tube is inserted into a living body using blood vessels, urethra, etc., particularly during insertion, the catheter tube can be accurately inserted in the living body without damaging the blood vessel wall or organs on the way. High operability and safety are required to reach a predetermined location.
[0004]
Therefore, the conventional catheter tube does not damage the blood vessel wall or organ during insertion, and it is easy to bend and has a flexible tube insertion tip, and the insertion tip is pushed into the living body to ensure a certain location. It is comprised from the tube-shaped torque transmission part reinforced in order to make it reach | attain.
[0005]
And as an example of the manufacturing method of such a catheter tube, the braiding which consists of wires, such as a corrosion-resistant metal wire and a fiber, is carried out to the whole outer periphery of the inner-layer tube of length dozens to several hundreds of meters in which the metal core wire was inserted. After continuously forming with a braiding machine to form a tube body with a reinforcing layer around the tube body, the tube body is cut to the actual length of the catheter tube (for example, 2 to 3 m) and the end of the reinforcing layer Is removed over a certain length, and then the outer layer resin is extruded over the entire tube body to cover it all at once, and then the metal core wire is stretched and pulled out from the tube body.
[0006]
[Problems to be solved by the invention]
By the way, such a catheter tube is required to have excellent operability and safety as described above, as well as excellent injectability with respect to a drug solution and a contrast medium and smooth insertion property when a guide wire is inserted.
[0007]
For this reason, recently, an inner layer tube made of a fluororesin having excellent lubricity (low friction resistance) such as polytetrafluoroethylene (PTFE) has been developed to improve the lubricity of the tube inner surface. .
[0008]
However, when the inner layer tube is formed of a fluororesin having excellent lubricity in this way, the adhesion of the reinforcing layer and the outer layer resin to the inner layer tube is reduced and peels off from the inner layer tube, resulting in excellent torque transmission. In addition, there is a drawback that operability is difficult to obtain.
[0009]
In addition, a method of imparting lubricity to the inner surface of the tube by coating the inner surface of the inner tube with a silicone-based paint has also been proposed. However, in this method, the paint flows into the living body together with a chemical solution or the like. There is a problem that when another catheter, guide wire, or the like is inserted therein, the function (lubricity) cannot be maintained for a long time because it is scraped off from its inner surface.
[0010]
Therefore, the present invention has been devised to effectively solve such problems, and its purpose is to improve torque transmission and operability while maintaining excellent injection performance and insertion performance. A novel method for producing a catheter tube is provided.
[0011]
[Means for Solving the Problems]
The present invention, after coating forming the reinforcing layer on the inner tube made of fluororesin, its length outer layer of the two or more different hardnesses on the reinforcing layer of the thermoplastic resin in order to solve the above problems In the catheter tube manufacturing method in which the coating is formed in multiple stages sequentially in the direction, the outer surface of the inner tube is previously defluorinated before or after the reinforcing layer is coated on the inner tube. The surface treatment is performed with a treatment liquid to remove the fluorine component in the surface layer portion, and the treatment degree is sequentially changed in multiple stages in the length direction of the inner layer tube .
[0012]
That is, as described above, when the inner layer tube is formed of a fluororesin excellent in lubricity, if the reinforcing layer or the outer layer is directly coated thereon, the adhesion of the reinforcing layer and the outer layer to the inner layer tube is reduced, Torque transmission and operability are greatly reduced. Therefore, in the present invention, the outer surface of the inner tube is pre-treated with a defluorination treatment liquid before the reinforcing layer is coated on the inner tube or after the reinforcing layer is coated. By removing in advance the fluorine component of the surface layer portion to be lowered, the adhesion of the reinforcing layer and the outer layer to the inner tube is greatly improved.
[0013]
As a result, the reinforcing layer and the outer layer with respect to the inner tube are not easily peeled off, so that it is possible to obtain a catheter tube excellent in torque transmission and operability while maintaining the original injection property and insertion property of the fluororesin. it can.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment for carrying out the present invention will be described with reference to the accompanying drawings.
[0015]
FIG. 1 is a partially cutaway side view showing an embodiment of a catheter tube 1 according to the present invention, FIG. 2A is a sectional view taken along line AA, and FIG. 2B is a sectional view taken along line BB. is there.
[0016]
As shown in the figure, this catheter tube 1 has a structure in which an insertion tip 3 having high elasticity is continuously formed at the tip of a reinforced tube-shaped torque transmitting portion 2.
[0017]
As shown in FIG. 1 and FIG. 2 (A), the torque transmission portion 2 is formed by coating a reinforcing layer (braid) 6 made of a wire 5 such as a metal wire or fiber on the outside of an inner layer tube 4 made of a fluororesin. In addition, an outer layer 7 made of a thermoplastic resin is also formed on the outer side, and the reinforcing layer 6 improves the crushing and bending resistance, and exhibits good torque transmission. Yes.
[0018]
On the other hand, as shown in FIGS. 1 and 2B, the insertion tip portion 3 has a two-layer structure that does not have the reinforcing layer 6 like the torque transmission portion 2, and thereby the resin has good elasticity. And flexibility is exhibited.
[0019]
Next, a method for manufacturing the catheter tube 1 of the present invention having such a structure will be described.
[0020]
First, as shown in FIG. 3, on a metal core wire 8 having a length of several tens to several hundreds of meters, a fluorine-based resin rich in lubricity (low friction resistance), for example, polytetrafluoroethylene (PTFE), One inner-layer tube that is continuously coated in the length direction with a fluorine resin such as ethylenetetrafluoroethylene (ETFE), polyfluoroalkoxy fluororesin (PFA), and tetrafluoroethylene hexafluoropropylene copolymer (FEP). 4, the surface of the inner layer tube 4 is defluorinated as shown in FIG. 4, for example, a mixed solution of sodium metal and ammonia, a mixed solution of sodium metal and tetrahydrofuran, or a mixed solution of sodium metal and naphthalene. Only the outer surface is treated with a solution containing an alkali metal such as. As a result, the fluorine component in the surface layer portion of the inner tube 4 that exhibits lubricity is forcibly removed, so that the lubricity of the outer surface is lowered. The surface treatment method is not particularly limited. For example, the inner layer tube 4 is directly immersed in a treatment tank in which the defluorination treatment liquid is stored, or the inner layer tube 4 is directly applied. Or the like can be easily adopted.
[0021]
Next, when the surface treatment of the inner layer tube 4 is performed in this way, the reinforcing layer is used by using a braiding machine (not shown) over the entire outer surface side of the inner layer tube 4 as shown in FIG. After forming the braid 6, as shown in FIG. 6, a part of the reinforcing layer 6 is fixed to a certain length by a conventionally known removal technique such as a chemical removal method, a mechanical removal method, or a laser removal method. That is, it is removed intermittently by the length of the insertion tip 3 described above. Here, the wire 5 constituting the reinforcing layer 6 is not particularly limited, and a metal wire such as stainless steel, a titanium-nickel alloy wire, platinum, or a hard fiber such as polyimide can be used. . Further, the diameter of the diameter of the metal core wire 8 is not particularly limited as long as the cross-sectional shape is circular, and the diameter varies depending on the size of the catheter tube to be obtained. Further, the thicknesses of the inner layer tube 4 and the reinforcing layer 6 are the same. The reinforcing layer 6 may be formed by winding the wire 5 around the inner tube 4 in a coil shape.
[0022]
After that, if the reinforcing layer 6 is intermittently removed in this way, a thermoplastic resin that becomes the outer layer 7 on the inner layer tube 4 as shown in FIG. Then, after extruding a polyethylene-based, polyvinyl chloride-based, fluororesin-based, or silicon-based thermoplastic resin to form a multilayer structure by further coating the outer layer 7 therearound, a reinforcing layer 6 is formed as shown in FIG. The catheter tube 1 as described above is obtained by dividing the actual catheter tube into a length of, for example, about 2 to 3 m at the removed position, and then drawing the metal core wire 8 and drawing it out. In the thermoplastic resin forming the outer layer 7, fine particles such as barium sulfate, bismuth oxide, tungsten carbide and the like may be appropriately added as a contrast agent.
[0023]
And in the catheter tube 1 of the present invention thus obtained, the inner layer tube 4 is made of a fluororesin having excellent lubricity, so that it has excellent injectability with respect to a drug solution or a contrast medium. Of course, the outer surface of the inner tube 4, that is, the surface side on which the reinforcing layer 6 and the outer layer 7 are formed is preliminarily defluorinated as described above. Since the surface treatment is performed with the treatment liquid, excellent adhesion to the reinforcing layer 6 and the outer layer 7 can be exhibited. As a result, the reinforcing layer 6 and the outer layer 7 are not easily peeled from the inner layer tube 4, so that excellent torque transmission and operability can be maintained for a long time.
[0024]
Next, FIG. 9 and FIG. 10 show another embodiment of the present invention, and an embodiment for a catheter tube in which the tube hardness is changed in multiple stages over the length direction. It is shown.
[0025]
That is, in the catheter tube 1 shown in the above embodiment, the hardness is constant in each of the torque transmission part 2 and the insertion tip part 3, but in the conventional catheter tube, there is an outer layer. A plurality of resins having different hardnesses are used as the resin constituting the resin 7, and these are sequentially coated in the length direction, and the operability is further improved by changing the tube hardness in multiple steps in the length direction. Things have been proposed.
[0026]
However, when such a catheter tube is obtained, the entire outer surface of the inner layer tube 4 is uniformly treated as described above, and then the outer layer resins having different hardnesses are sequentially coated in multiple stages. However, the initial surface effect gradually decreases due to the heat history of the outer layer coated first, and the adhesion of the outer layer resin coated thereafter may decrease.
[0027]
For this reason, in this embodiment, the deterioration of the surface treatment effect due to the multi-stage coating of the outer layer resin is suppressed by performing the multi-stage surface treatment on the inner tube 4 with the length of the actual catheter tube as one unit. It is what you do.
[0028]
For example, when the actual length of the catheter tube is 1800 mm and three types of thermoplastic resins 7a, 7b, and 7c having different hardness are used as the outer layer resin coated on the inner layer tube 4, first, As shown in FIG. 9, the surface treatment range is divided into three ranges (100 mm, 200 mm, 1500 mm) from the tip (insertion tip) side, and the degree of treatment is gradually increased from the rear end side to the tip side. It should be noted that the level of the processing degree (strength) can be easily adjusted by changing the concentration of the processing liquid or changing the processing time.
[0029]
Then, as shown in FIG. 10 (1), after the necessary reinforcing layer 6 is formed on the inner tube 4, as shown in FIGS. When the outer layer resins 7a, 7b, and 7c having different thicknesses are coated, the surface effect in the adjacent range is somewhat reduced due to the thermal history during the previous outer layer resin coating process. The range is pre-treated to a higher degree than the coated range, so even if the surface effect of the adjacent range is somewhat reduced due to the thermal history, the surface treatment effect is not covered at the time of actual coating. It becomes possible to maintain at least the same as the surface treatment range.
[0030]
As a result, a sufficient surface treatment effect is maintained in any range and an excellent adhesion can be obtained. Therefore, even in a multi-stage covered catheter tube, excellent lubrication is achieved as in the above embodiment. Inconveniences such as a decrease in torque transmission force and operability due to peeling can be surely avoided while exhibiting performance.
[0031]
In the present embodiment, the example in which the reinforcing layer 6 is provided in the torque transmitting portion 2 has been described. However, the reinforcing layer 6 is omitted, and a configuration in which a necessary torque is exhibited only by a change in the hardness of the outer layer resin 7 is described. It is also good. Further, it goes without saying that the order and range of coating of the outer layer resin 7 or the number of outer layer resins 7 and processing ranges to be used are not limited to the present embodiment.
[0032]
【Example】
Hereinafter, specific examples will be described in order to demonstrate the method of the present invention.
[0033]
(Example)
First, a 0.03 mm-thick PTFE layer (inner tube) was formed on a 0.6 mm silver-plated annealed copper wire by repeating water-dispersed PTFE dispersion coating and baking, and then 16 SUS strands having a diameter of 0.03 mm ( One core) was braided at a pitch of 2.5 mm, and a core tube having a water dispersion type PTFE dispersion applied and baked from the braid (reinforcing layer) was manufactured to 200 mm.
[0034]
Next, the core tube is immersed in a treatment tank (each tank length 1500 mm, 200 mm, 100 mm) adjusted to a concentration of 30, 50, 60% using an alkali metal solution (manufactured by Junkosha; Tetra Etch A). After sequentially repeating the washing, three types of polyamide-based outer layer resins (Shore D80, 60, 40) having different hardness according to a predetermined length are divided into three times on the tube, and the entire length is sequentially increased from the lowest treatment level. Then, it was cut at intervals of 1800 mm in length, and a silver-plated annealed copper wire was drawn out to obtain a tube body having an outer diameter of 0.95 mm.
[0035]
And it cut | disconnected by sample length 50mm from each part from which the hardness of the tube body obtained in this way was divided, and when these were halved and the peeling force between a PTFE layer and an outer layer was measured, it peeled in any site | part A product with no difference in force was obtained.
[0036]
For torque transmission, a sample tube with a length of 1800 mm is inserted into a U-shaped tube bent at a radius of 50 mm by bending a polyethylene tube with an inner diameter of 3.0 mm, an outer diameter of 5.0 mm, and a length of 500 mm. Is projected 50mm from one end of the polyethylene tube, and the rotation angle of the tip is measured every 360 ° rotation on the hand side. The rotation is stable with a rotation delay of 90 ± 10 ° against the target within 90 ± 20 °. Transmitted to the tip.
[0037]
(Comparative example)
A tube body similar to that of the example was obtained except that the core tube obtained in the same manner as in the example was passed through a treatment tank of an alkali metal solution (Junkosha; Tetra Etch A) adjusted to a concentration of 30% to uniformly treat the surface. When manufacturing and evaluating the peel force and torque transferability by the same method, the difference in peel force of each part is large, and the torque transferability varies from 90 to 200 ° with respect to the target value of 90 ± 20 °. The rotation delay was very unstable.
[0038]
【The invention's effect】
In short, the present invention is excellent in lubricity because the surface of the inner layer tube is surface-treated with a defluorination treatment liquid in advance when the reinforcing layer and the outer layer resin are coated on the inner layer tube. It is possible to improve the adhesion of the reinforcing layer and the outer layer resin to the inner layer tube made of a fluororesin. As a result, peeling of the reinforcing layer and the outer layer resin can be prevented in advance, so that it is possible to reliably prevent a decrease in torque transmission performance, etc., and injection performance, insertion performance, torque transmission performance, operability, safety It is possible to provide a high-quality catheter tube excellent in all of the properties.
[Brief description of the drawings]
FIG. 1 is a partially broken side view showing an embodiment of a catheter tube according to the present invention.
FIG. 2A is an enlarged cross-sectional view taken along line AA in FIG.
(B) is the BB expanded sectional view in FIG.
FIG. 3 is an overall schematic view showing a state in which an inner layer tube is formed on a metal core wire.
4 is an overall schematic view showing a state where the outer surface of the inner layer tube shown in FIG. 3 is uniformly surface-treated with a defluorination treatment liquid.
5 is an overall schematic view showing a state in which a reinforcing layer is formed on the inner layer tube shown in FIG. 4; FIG.
6 is an overall schematic view showing a state in which a part of a reinforcing layer is intermittently removed at regular intervals on the inner layer tube shown in FIG. 5;
7 is an overall schematic view showing a state in which an outer layer resin is further formed on the inner layer tube body shown in FIG. 6. FIG.
8 is an overall schematic view showing a state in which the inner layer tube body shown in FIG. 6 is divided into a plurality at regular intervals. FIG.
FIG. 9 is a conceptual diagram showing a state in which multi-stage surface treatment is performed along the length direction of the outer surface of the inner layer tube.
FIG. 10 is an explanatory diagram showing a process of coating and forming outer layer resins having different hardnesses on the inner layer tube shown in FIG. 9 in multiple stages.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Catheter tube 2 Torque transmission part 3 Insertion tip part 4 Inner layer tube 5 Wire material 6 Reinforcement layer (braid)
7 Outer layer (resin)
8 Metal core wire

Claims (4)

  After a reinforcing layer is coated on the inner tube made of fluororesin, an outer layer made of two or more kinds of thermoplastic resins having different hardnesses is coated on the reinforcing layer in multiple steps in the length direction. In the catheter tube manufacturing method described above, the outer surface of the inner tube is subjected to surface treatment with a defluorination treatment liquid before or after the reinforcing layer is coated on the inner tube or after the reinforcing layer is coated. A method for producing a catheter tube, wherein the fluorine component is removed and the degree of treatment is sequentially changed in multiple stages in the length direction of the inner layer tube. The fluororesin constituting the inner tube is any one of polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), polyfluoroalkoxy fluororesin (PFA), and tetrafluoroethylene hexafluoropropylene copolymer (FEP). or the manufacturing process of the catheter tube according to claim 1 which comprises using a mixture of these resins.   3. The thermoplastic resin constituting the outer layer is any one of polyurethane, polyamide, polyimide, polyethylene, polyvinyl chloride, fluororesin, and silicon. The manufacturing method of the catheter tube of description. 4. The method according to claim 1, wherein any one of a mixed solution of sodium metal and ammonia, a mixed solution of sodium metal and tetrahydrofuran, or a mixed solution of sodium metal and naphthalene is used as the defluorination treatment liquid. The manufacturing method of the catheter tube of description.

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