JPS5875553A - Medical tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION I. BACKGROUND OF THE INVENTION Technical Field The present invention relates to medical tubes. Furthermore, *L< is
This article relates to improvements in tubes used in various medical devices.

Prior art and its problems Conventionally, medical tubes made of soft polyvinyl chloride have been widely used, and are used in infusions, transfusion vessels, artificial kidney circuits, and catheter-free medical devices.

This is because soft polyvinyl chloride has excellent processability and adhesive properties, is easy to handle when assembling medical devices, and can be mixed with a plasticizer arbitrarily, making it easy to adjust the flexibility and properties.

However, when soft polyvinyl chloride contains a plasticizer and is used for medical tubes, there is a risk that the plasticizer will elute and migrate into blood, medical solutions, and the like.

Conventionally, in order to prevent such migration of plasticizer, a technique is known in which a polyvinyl chloride sheet is subjected to plasma treatment. However, such a technique cannot be practically applied to the inner surface of a tube.

Due to these circumstances, the materials used to form medical tubes are
It is necessary to replace it with one that does not contain additives.

In this case, excellent materials such as silicone tubes are known as materials that are highly flexible and do not require plasticizers. However, none of these materials can be extruded, resulting in high costs when molded into a tubular shape, and cannot be bonded with adhesives or high-frequency welding, making secondary processing impossible. Extremely difficult to assemble into tools.
In addition, it is expensive.

On the other hand, tubes made of various olefin polymers are known, but when used as medical tubes, K still lacks adhesiveness, has poor flexibility, is difficult to bend, and the tube itself The tube breaks when bent, resulting in fluid blockage.

■ Purpose of the Invention The present invention was made in view of the above-mentioned circumstances, and its main purpose is to improve the characteristics of conventional medical tubes made of soft polyvinyl chloride, especially flexibility, processability, and adhesive properties. Our goal is to provide medical tubes that do not contain any eluates, while having the same or better properties.More specifically, our objective is to provide medical tubes that do not contain any additives, are free of eluates, have excellent properties, and are resistant to tube breakage. It is an object of the present invention to provide a medical tube that has extremely good properties overall, such as extremely low amount, excellent recovery properties after deformation, extrusion processability, and excellent adhesiveness and secondary processability. .

The present inventors have conducted intensive research for this purpose, and as a result have come up with the present invention.

That is, the present invention is a medical tube characterized by being formed into a tubular shape and made of chlorinated polyethylene.

Embodiments of the present invention relate to specific configurations that more effectively achieve the above objects, and are as follows.

1) The chlorine content of chlorinated polyethylene is 25 to 25% by weight
45- The medical tube of the present invention.

II) The medical tube of the present invention or 1) above, which has an initial elastic modulus of 5 #/d or less.

Il) The medical tube of the present invention or the above-mentioned l) or If), which has an inner diameter of 1 to 20.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

The medical tube of the present invention is made of chlorinated polyethylene.

The chlorinated polyethylene used is polyethylene, especially medium-density to high-density polyethylene, which has been chlorinated according to a conventional method. Chlorine is bonded randomly on the polyethylene chain, and the degree of chlorination, that is, the chlorine content, is as follows: The weight ratio is preferably 25 to 45%, more preferably 30 to 40%.

With such a chlorine content, the elastic properties are further improved, tube bending is significantly reduced, and the restorability after deformation is significantly improved. Such flexibility and properties are superior to that of soft polyvinyl chloride. Furthermore, the removability and impact resistance at low temperatures are also much better than that of soft polyvinyl chloride.

The molecular weight of the chlorinated polyethylene to be used is not particularly limited, but a number average molecular weight of approximately 40,000 to 300,000 may be used.

Moreover, there is no particular restriction on its distribution.

Further, the density may normally be about 1.00 to 1.25.

The chlorinated polyethylene used may be a blend of two or more of them. Such chlorinated polyethylene is molded into a tubular tube.

In this case, the initial elastic modulus of the formed tube is 5 k
It is preferable that it is less than g/ml.

Here, the initial elastic modulus G is the value at the rising edge of the deformation-stress curve in the small deformation range, and is based on JIS K71.
According to 13, G=W-17Δ!・Calculated in mu. Here, W is load -1! is the original length, A is the cross-sectional area, and Δ is the elongation.

When the initial elastic modulus is 5#/- or less, the malleability is significantly reduced, tube bending is reduced, and restorability is improved.
Furthermore, the malleability and impact resistance at low temperatures are also improved.
In this case, the initial elastic modulus is 0.1-4.0 #/11
A range of 7 is most preferable in terms of flexibility.

In order to adjust the initial elastic modulus to 5#/- or less, the conditions can be easily determined experimentally by changing the chlorine content, molecular weight, crystallinity, etc. of the chlorinated polyethylene.

Furthermore, the absorbance of the tube is 500.
It is preferable that the amount is 0.18 to 0.65 per intestine thickness.

On the other hand, when molding KI is used, there is no need to add a plasticizer to the chlorinated polyethylene. Furthermore, even if it is necessary to add additives depending on the application, the amount added can be kept to a very small amount. Therefore, elution from the inner wall of the tube is extremely difficult.

On the other hand, shaping can be carried out by conventional extrusion processing. For this reason, molding becomes extremely easy and costs are low.

Tubes formed in this way usually have an inner diameter of 1 to 20
The thickness is approximately Mk, and the wall thickness is approximately 0.3 to 3.5 m.

With such dimensions, it exhibits extremely good townability.

Note that the cross-sectional yield, dimensions, etc. can be varied.

Such medical tubes of the present invention can be used as connection tubes for infusion sets and blood transfusion sets, tubes for body fluids or blood circuits in various extracorporeal circulation circuits such as dialysis machines and artificial kidneys, tubes for indwelling needles, various catheters, etc. Furthermore, K is used as an fx-p for a breathing circuit, etc.

These various medical devices are manufactured by subjecting the medical tube of the present invention to other components in a predetermined arrangement by high-frequency bonding, etc., or by performing other desired secondary processing.

厘Specific Effects of the Invention The medical tube of the present invention is made of chlorinated polyethylene and does not require the addition of a plasticizer, so there is very little elution from the inner wall into body fluids, blood, drug solutions, etc.

It also exhibits superior flexibility and low-temperature properties than soft polyvinyl chloride.

That is, tube bending is extremely rare, and the bending radius of curvature at which tube bending occurs is extremely small compared to polyvinyl chloride. It also has good recovery properties against deformation.
For example, when a stenosis occurs due to a cramp, it restores immediately after the stenosis is removed, has good followability and resistance to stenosis, and has excellent constant flow properties compared to polyvinyl chloride.

Furthermore, when stored at low temperatures for a long period of time or at low temperatures, polyvinyl chloride's flexibility decreases, but the tube of the present invention has less bending (and has good constant flow performance). It also has high impact resistance.

In addition, ethylene oxide gas sterilization is used as a sterilization process.
When this is done, the degassing rate of the ethylene oxide gas adsorbed after sterilization is faster than that of soft polyvinyl chloride. This is thought to be due to the fact that since it does not contain a plasticizer, the amount of ethylene oxide adsorbed by the plasticizer and remaining is reduced.

In addition, it is resistant to R-ray annihilation, and the changes in its physical properties or characteristic values are extremely small. It is possible to bond by induction heating or adhesive, and the bonding process is easy. In addition, secondary processing can be easily performed when assembling into medical devices.

According to the above embodiment 1) K, the chlorine content is 25 to 45
- If chlorinated polyethylene is used, the above-mentioned flexibility will be even better.

Further, according to the embodiment 1i), when the initial elastic modulus is set to 5#/- or less, the above-mentioned acceptability and 5 properties are further improved compared to the JP beam.

Furthermore, the inner diameter of the tube is 1 to 20 m! In No. 1, folds and several moving beds with constant flow characteristics are noticeable.

The present inventors conducted an experiment to confirm the effects of the present invention. An example is shown below.

Experimental Example 1 High-density polyethylene with a number average molecular weight of 300,000 o/density of 0.95 was chlorinated, and the chlorine content was 35 vt% and the density was 1.1.
A chlorinated polyethylene (PE-α) of No. 5 was obtained.

By extruding this chlorinated polyethylene, the inner diameter is 3
It was molded into a tubular shape with an outer diameter of 4 s.

Separately, an identical tube was produced by extrusion processing from flexible polyvinyl chloride (PVC; 103EP manufactured by Nippon Zeon Co., Ltd.) containing a plasticizer and a stabilizer.

Furthermore, ethylene-vinyl acetate copolymer (EVA; manufactured by Toyo Ichida Kogyo Co., Ltd.) with a vinyl acetate content of 15wt9 was added.
630), a tube was similarly produced.

For these three types of tubes, JI8 K7113v
e Accordingly, the initial elastic modulus G was measured.

The results are shown in Table 1.

Note that Table 1 also shows the absorbance of the three types of tubes at 500 nm and a thickness of 1 m111.

Table 1 Furthermore, the eluate test for these 3111 tubes was conducted.

That is, take the tube 15Ii, cut it into small pieces, and add about 1 liter of water.
After boiling at 50- for 30 minutes, water was added to bring the temperature to 150- and this was used as a test solution.

To this test solution 101, 20 MLt of 0.01N hydrium permanganate solution and 1.0 m of dilute sulfuric acid were added, and after boiling for 3 minutes, it was cooled. To this, 0.1 g of potassium iodide and 5 fk of starch test solution were added. Titrated with .0IN sodium thiosulfate solution. Reducing substance elution amount (ΔKMaO,) shown by the difference in the consumption amount of potassium permanganate solution from the blank test
are shown in Table 2.

In addition, when test liquid VcKα was added and pm measurement was performed according to the pharmacopoeia, the difference from the blank shown in Table 2 (49M
)was gotten.

Furthermore, using these tubes of 0.5 m, they were tied into a loop, shaken for 1 hour, and a hemolysis test was performed. The occurrence of hemolysis is indicated by + and - in the table.

Table 2 From the results shown in Table 2, it can be seen that the tube of the present invention has an extremely small amount of elution.

Separately, the following flexibility test was conducted.

First, three types of tubes were wound around cylinders having various diameters, and the radius of curvature at which breakage occurs was measured.

Table 3 shows the results at 0°C and 25°C.

Further, the tube was made 1 m long, a chamber and a bottle needle were attached to one end of the blade, a needle was attached to the other end via a rubber tube and an octopus tube, and a roller crease was attached to the center of the tube.
Pour tap water into this tube at 600 H,O,
Adjust the flow rate to about 5-7 minutes using a roller cremator,
The flow rate Q1 after 30 minutes was measured with respect to the flow rate Q0 at the beginning of the flow, and the constant flow performance was evaluated. The results are shown in Table 3.

Table 3 From the results in Table 3, the tube of the present invention has a very good
It can be seen that it has excellent properties in terms of temperature and low temperature properties.

Furthermore, apart from these, ethylene oxide gas sterilization was performed, and the residual amount of ethylene oxide after 1110 days was measured by gas chromatography method. tk4 the result
Shown below.

Further, R-ray sterilization was performed, and the rate of change in 49M after sterilization, the permanganate consumption test value ΔKMIIO4, and the amount of change in Shore D hardness were measured. The results are shown in Table 4.

Table 4 The results shown in Table 4 show that the tube of the present invention has very high compatibility and resistance to ethylene oxide gas and R-ray sterilization partners.

Experimental Example 2 As shown in Table 5 below, tubes with different initial elastic moduli were produced in the same manner as in Experimental Example 1 by changing the chlorine content of PE-α, the crystallinity, and the average molecular weight of polyethylene.

Table 5 shows the characteristics of each of these tubes.

The results of the ° test for each tube after sterilization with ethylene oxide gas and R-rays were the same as in Experimental Example 1.

From the results shown in Table 5, it can be seen that when the chlorine content of chlorinated polyethylene is 30 to 40% and the initial elastic modulus is 5 #/Peng or less, extremely excellent flexibility is exhibited.

Patent applicant: Chill Seven Co., Ltd. Representative Patent Attorney Yo Ishii -

Claims (1)

[Scope of Claims] 1. A medical tube made of chlorinated polyethylene formed into a tubular shape. 2. The chlorine content of chlorinated polyethylene is 25 in 1i ratio
45%. The medical tube according to claim 1. 3. The medical tube according to claim 1 or 2, which has an initial elastic modulus of 5 Jt9/ml or less. 4. The medical tube according to any one of claims 1 to 3, wherein the tube has an inner diameter of 1 to 2011i.