JPH0212113B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical tube and a method for manufacturing the same. More specifically, the present invention relates to a medical tube used in an infusion set, an infusion bag, a blood transfusion set, a blood bag, a blood circuit, a continuous ambulatory peritoneal dialysis (CAPD) device, etc., and a method for manufacturing the same.

Prior Art Infusion fluids consisting of sugars, aminos and electrolytes are
If the solution is stored in an infusion bag in advance, a Maillard reaction may occur during autoclave sterilization and discoloration may occur. For this reason, it is necessary to aseptically mix the necessary component liquids at the time of use into a previously sterilized infusion bag and then administer the mixture to the patient. A closed system is usually employed to aseptically mix such component liquids. For example, a medical container is used which is equipped with a container liquid guide tube, etc., in which a discharge port, a mixed injection port, a bottle needle are attached to the tip, and a plurality of liquid collection tubes are connected via a branch pipe. Component liquids are sampled, introduced into the container body through a liquid guide tube, and mixed. After the liquid sample is completed, the liquid guide tube is tied and hermetically sealed.

On the other hand, medical containers that are to be incorporated into such closed systems need to transport the liquid to be treated using the difference in gravity and the flexibility of the container material, and are made of flexible synthetic resin. There is. Synthetic resin materials with excellent flexibility include soft vinyl chloride resin and ethylene-vinyl acetate copolymer. Ethylene-vinyl acetate copolymer is preferred.

However, the closed system medical container has a problem in that when the liquid guide tube is tied and sealed after the liquid collection is completed, the outer surfaces of the liquid guide tubes are in close contact with each other, making it difficult to tie a knot easily. Ta. Therefore, if an attempt is made to forcefully pull the tube into a knot, the liquid guiding tube may break.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to provide a novel medical tube and a method for manufacturing the same. Another object of the present invention is to provide a medical tube that can extremely easily form a knot to seal the channel, and a method for manufacturing the same.

These purposes are to have a fluid flow path inside;
A large number of ribs are formed on the entire outer surface of a flexible synthetic resin tube extending in the axial direction of the tube,
A large number of fine protrusions are formed almost uniformly on the tube surface between the tops of each rib, and the height from the concave bottom to the convex top of the cross section of the rib is
This can be achieved by a medical tube capable of blocking fluid flow by tying, characterized in that the distance between the tops of the cross-section of each rib is 0.2-0.8 mm.

Further, in the present invention, the distance between the protrusions is 5
The medical tube is ~100 μm, preferably 5-30 μm. In the present invention, the height of the protrusion is 1 to
It is a medical tube with a diameter of 10 μm. The present invention also provides a medical tube in which the flexible synthetic resin is a soft vinyl chloride resin or an ethylene-vinyl acetate copolymer, preferably an ethylene-vinyl acetate copolymer.

The above objects are also achieved by setting the temperature of the tip of the die 10 to 70 degrees Celsius lower than the temperature of the center of the die in a method of manufacturing a medical tube having a fluid flow path therein, and forming a tube on the surface of the tube. By extruding flexible resin from an annular outlet having grooves corresponding to the shape of the ribs, the entire outer surface of the tube has a height from the concave bottom to the convex top.
A large number of ribs having a diameter of 0.08 to 0.8 mm are formed extending in the axial direction of the tube, and a large number of fine protrusions are formed almost uniformly on the surface of the tube between the tops of each rib. The present invention is also achieved by a method for manufacturing a medical tube capable of blocking fluid flow by tying the tube.

Further, the present invention is a method for manufacturing a medical tube in which the temperature difference between the center portion of the die and the tip portion of the die is 30 to 50°C.

Specific Configuration of the Invention Next, one embodiment of the present invention will be described with reference to the drawings. That is, as shown in FIGS. 1 to 3, a large number of ribs 3 are formed on the entire outer surface 2 of a tube 1 made of flexible synthetic resin, extending in the axial direction of the tube 1. A large number of even finer protrusions 4 are formed almost uniformly on the tube surface between the tops of the ribs 3 and the tops of the adjacent ribs 3. For example, an electron microscope (magnification: 1000x)
By using , you can see the formation approximately as shown.

In such a tube 1, the distance d between the tops of the cross section of each rib is 0.2 to 0.8 mm, preferably 0.3 mm.
~0.5mm. Also, the height h from the concave bottom to the convex top is 0.08 to 0.8 mm, preferably 0.1 to 0.6 mm.
It is. Furthermore, the distance p between the protrusions 4 is 5 to 100 μm, preferably 5 to 30 μm,
Its height a is 1-10 μm, preferably 2-5 μm.

The reason for providing a large number of ribs is to reduce the contact area between tube surfaces in order to easily form a knot and seal the flow path, which is the objective of the present invention. Further, the height from the concave bottom to the convex top of the cross section of the rib needs to be 0.08 to 0.8 mm. If it is outside this range, the contact area between the tube surfaces will be too large when tying.
Undesirable.

The reason for providing the protrusions is to improve the sliding between the tube surfaces, and the effect of the present invention can be obtained by providing both the ribs and protrusions, and if either of them is missing, the desired effect will not be achieved. I can't get it. Further, the various numerical limitations described above indicate more preferable ranges for achieving the effects of the present invention, and the ranges are averages of preferable values taking into consideration manufacturing errors and the like.

These dimensions can be determined, for example, by so-called universal projectors [e.g.
It can be measured by using a projector (projetor) V-12; manufactured by Nikon Corporation. The number of ribs is 70 to 95 in the circumferential direction.
The number of books, preferably 60 to 90, is more preferable in terms of achieving the effects of the present invention.

As the flexible synthetic resin constituting the medical tube according to the present invention, soft vinyl chloride resin, ethylene-vinyl acetate copolymer, etc. are preferred, and ethylene-vinyl acetate copolymer is particularly preferred.

In addition to vinyl chloride homopolymers, soft vinyl chloride resins include vinyl acetate, vinylidene chloride,
There are copolymers with comonomers such as acrylonitrile and styrene, and the average degree of polymerization is 700 to 3000, preferably 1000 to 2500, and 30 to 80% by weight, preferably 40 to 70% by weight of plasticizer. is blended.
As a plasticizer, dibutyl phthalate (DBP),
Di-2-ethylhexyl phthalate (DOP), diheptyl phthalate (DHP), didodecyl terephthalate (DDP), di-2-ethylhexyl adipate (DOA), di-2-ethylhexyl sebatate (DOS), etc. 2-ethylhexyl phthalate is preferred.

The ethylene-vinyl acetate copolymer has a vinyl acetate content of 3 to 35% by weight, preferably 6 to 30% by weight, and has an average molecular weight of 14,000 to 30% by weight.
25,000, preferably 20,000 to 25,000.

Such a medical tube is obtained by extrusion molding using an extrusion molding machine equipped with a die. For example, as shown in FIG. 4, the die 10 is made of a flexible synthetic resin extruded from an extrusion molding machine (not shown) to which the die 10 is connected. The melt 13 passes through the resin passage 14 of the die body 11 and is extruded from an annular outlet 15 formed in the die tip 12 which communicates with the resin passage 14 . The cross-sectional shape of this annular discharge port 15 is almost the same as the cross-sectional shape of the obtained tube, and grooves are formed on the outer edge according to the shape of the ribs 3 formed on the outer surface 2 of the tube 1. . Therefore, in the present invention, it is necessary to perform extrusion molding by setting the temperature of the die tip 12 to be 10 to 70 degrees Celsius lower than the temperature of the die body 11, which is the central portion of the die, and in particular, to set the temperature to be 30 to 50 degrees Celsius lower. It is preferable to set As a result, a large number of smaller protrusions 4 are formed on the surface between the tops of each rib 1. The reason why minute protrusions are formed on the tube surface under such conditions is that the synthetic resin, which is molten in the die body 11 and has high fluidity, passes through the low temperature section before being extruded into the air from the discharge port. Since it is slowly cooled at the die tip 12, the fluidity deteriorates and fine protrusions (embosses) 4 are formed. Note that temperature control of each part of the die can be performed electrically or by other methods.
For example, when using ethylene-vinyl acetate copolymer as the synthetic resin, the temperature of the die body is
The temperature is 170~190℃, but the temperature at the die tip is 140℃.
By performing extrusion molding at a temperature of ~160℃,
The protrusion is formed.

The surface of the tube thus formed can be coated with silicone if necessary. For example, the coating can be applied by spraying silicone evenly and non-stickly onto the surface of the tube. The coating does not have to completely uniformly cover the entire surface of the tube, but may instead have dots of silicone. This makes knot formation easier. The medical tube according to the invention obtained in this way is easy to tie and thereby easily prevents fluid flow;
It can be used for infusion sets, infusion bags, blood transfusion sets, blood bags, blood circuits, continuous ambulatory peritoneal dialysis (CAPD) equipment, etc. For example, as shown in FIG. In a container equipped with a mixed injection spout 25 with a mixed injection spout rubber stopper 24 connected to the inside of the container liquid introduction tube 29, a liquid collection tube 27 with a bottle needle 26 attached to the tip is connected via a branch pipe 28. Used by connecting to a container. Note that the reference numeral 30 is a cap of the bottle needle 26. In such an infusion set, the cap 30 is removed, each component liquid of the infusion is collected from the bottle needle 26, and after the liquid has been collected from the container liquid guide tube 29 into the liquid main body 21, the container liquid guide tube 29 is removed. are tied as shown in FIG. 6 to close the flow path and prevent the flow of liquid.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 An ethylene-vinyl acetate copolymer (vinyl acetate content 28% by weight) with an average molecular weight of about 25,000 was prepared using a die shown in Figure 4, with the die body temperature set at 180°C and the die tip temperature set at 150°C. A tube with an outer diameter of 7.5 mm and an inner diameter of 5 mm was extruded, and the number of ribs in the axial direction of the tube thus obtained was 89.
The distance d between the tops of the ribs is 0.3 mm, the height h of the ribs is 150 μm, the height a of the protrusion formed on the surface between the tops is 3 μm, and the distance p between the protrusions is It was 20μm.

Example 2 The surface of the tube obtained in Example 1 was coated with silicone (dimethyl silicone) to a non-sticky extent.

Comparative Example 1 When the same method as in Example 1 was carried out except that the temperature of both the die body and the die tip were set to 180°C, a tube having the same rib spacing d and rib height h was obtained. was obtained, but no fine protrusions were formed on the surface between the tops.

Comparative Example 2 The surface of the tube obtained in Comparative Example 1 was coated with silicone (dimethyl silicone) to the extent that it did not become sticky.

Test Example The tubes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were sterilized with ethylene oxide gas,
After cutting it to a length of 150cm, tie a knot,
I chucked both ends of the tube into a strograph. When a knot with a total length of 100 mm was pulled for a length of 500 mm at a pulling speed of 200 mm/min and the dimension w of the widest part of the knot was measured as shown in Figure 6, the graph shown in Figure 7 was obtained. .

Moreover, the fracture rate of the tube at this time was as shown in Table 1.

Table 1 Sample tube rupture rate Example 1 4/20 (20%) Example 2 2/20 (10%) Comparative example 1 14/20 (70%) Comparative example 2 12/20 (60%) The relationship between tube tensile length and tensile force was as shown in FIG. In the figure, curve A is for the tube of Example 1, curve B is for Example 2, curve C is for Comparative Example 1, and curve D is for Comparative Example 2.

Specific Effects of the Invention As described above, the present invention forms a large number of ribs extending in the axial direction of the tube on the entire outer surface of the tube made of flexible synthetic resin, and the top and top of each rib. This is a medical tube that can prevent fluid flow by tying a medical tube, which is characterized by having a large number of evenly finer protrusions formed almost uniformly on the surface between the tube and the tube. Ten
It used to require about 15 kg of force, but it is possible to make a knot that can prevent fluid flow with about 5 to 10 kg of force. Also, while tying the tube knot,
Conventionally, the tube was prone to breakage, but the tube according to the present invention does not break with this level of force, and its strength has been improved.

In addition, in such a tube, the temperature at the tip of the die is set 10 to 70 degrees Celsius lower than the temperature at the center of the die, and the flexible resin is extruded from an annular outlet having grooves that correspond to the shape of the ribs. Since the molten flexible resin is slowly cooled and extruded into the air, fine protrusions (embosses) are formed on its surface, and this causes the molecules to be oriented in a certain direction. Therefore, mechanical strength such as tensile strength is improved.

Therefore, it is suitable as a medical tube for use in infusion sets, infusion bags, blood transfusion sets, infusion bags, blood circuits, continuous peritoneal dialysis (CAPD) devices, and the like. Particularly when using ethylene-vinyl acetate copolymer as a flexible synthetic resin, it was difficult to prevent the flow of fluid by knotting with conventional products, or the tensile strength was insufficient, so the present invention Medical tubes are highly effective.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a medical tube according to the present invention, FIG. 2 is an enlarged view of the X portion in FIG. 5 is a front view showing an example of the use of the medical tube according to the present invention; FIG. 6 is a front view showing a tied state of the medical tube; FIG. 7 is a graph showing the size of a knot in a medical tube, and FIG. 8 is a graph showing the relationship between tube pulling length and pulling force. 1...tube, 2...outer surface, 3...rib,
4...Protrusion, 10...Dice, 11...Dice body, 12...Die tip, 13...Resin melt, 14...Resin passage, 15...Annular discharge port, 2
0... Outlet tube, 21... Container body, 27
...Liquid collection tube, 28... Branch pipe, 29... Container liquid guide tube.

Claims (1)

[Scope of Claims] 1. A tube made of flexible synthetic resin having a fluid flow path therein, with a large number of ribs extending in the axial direction of the tube formed on the entire outer surface of the tube, and a top portion of each rib. A large number of fine protrusions are formed almost uniformly on the tube surface between the ribs and the top, and the height from the concave bottom to the convex top of the cross section of the rib is 0.08 to 0.8 mm, and the cross section of each rib is 0.08 to 0.8 mm. The distance between each top of is 0.2~
A medical tube that is 0.8 mm in diameter and can be tied to prevent fluid flow. 2. The medical tube according to claim 1, wherein the distance between the protrusions is 5 to 100 μm. 3. The medical tube according to claim 1, wherein the distance between the protrusions is 5 to 30 μm. 4. The medical tube according to claim 2 or 3, wherein the protrusion has a height of 1 to 10 μm. 5. The medical tube according to any one of claims 1 to 4, wherein the flexible synthetic resin is a soft vinyl chloride resin or an ethylene-vinyl acetate copolymer. 6. The medical tube according to any one of claims 1 to 4, wherein the flexible synthetic resin is an ethylene-vinyl acetate copolymer. 7 In a method for manufacturing a medical tube having a fluid flow path inside, the temperature of the tip of the die is set 10 to 70°C lower than the temperature of the center of the die, and the shape of the rib formed on the surface of the tube is adjusted. By extruding flexible resin from an annular outlet with corresponding grooves, a large number of ribs with a height of 0.08 to 0.8 mm in cross section from the concave bottom to the convex top are formed on the entire outer surface of the tube. The tube is formed to extend in the axial direction of the tube, and a large number of fine protrusions are formed almost uniformly on the surface of the tube between the tops of the respective ribs. A method for manufacturing a medical tube that can prevent 8 The temperature difference between the center of the die and the tip of the die is 30~
The method for manufacturing a medical tube according to claim 7, wherein the temperature is 50°C.