JPH0956808A - Tube for medical treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube for medical treatment which consists of a non- polyvinyl chloride system and is highly practicable and soft by incorporating a compsn. consisting of an ethylene-vinyl acetate vinyl copolymer, ethylene- acrylate copolymer or ethylene methacrylate copolymer and low-molecular org. ester plasticizer into this tube. SOLUTION: This tube for medical treatment contains the compsn. consisting of the ethylene-vinyl acetate vinyl copolymer, the ethylene-acrylate copolymer or the ethylene methacrylate copolymer and the low-molecular org. ester plasticizer. Both components of the compsn. have excellent affinity and compatibility and the tube having the excellent transparency and softness is obtd. While the tube is produced by a known melt extrusion method by tubular dies, the extrusion temp. varies with compsn. and is generally 150 to 200 deg.C. The applications of the tube include transportation of blood or its components, culture media, buffers, transfuses, peritoneal dialysis liquids, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft tube (connection pipe) suitable for carrying a liquid handled in the medical field such as blood and infusion.

[0002]

2. Description of the Related Art In addition to safety and hygiene, materials for tubes used in medical fields such as blood sampling, blood transfusion, and liquid transfusion
Flexibility and transparency are required. Although the most general-purpose flexible polyvinyl chloride tubes currently satisfy these properties, the problem of waste disposal has been pointed out, and conversion to other materials is required. (1) Polyethylene, ethylene-based copolymers (ethylene-vinyl acetate copolymer, ethylene acrylate copolymer, etc.), crystalline polyolefins such as propylene-based copolymers, (2) styrene-based elastomers, olefin-based elastomers, polyester-based elastomers , A polyamide elastomer, a so-called thermoplastic elastomer such as polyurethane, and (3) a fluorine-based or silicone-based thermoplastic or thermosetting elastomer. However, (2) and (3) are both expensive and difficult to use as a substitute for polyvinyl chloride.
The item (1) has high rigidity, and has a problem that flexibility required for a medical tube is difficult to be exhibited. The fact is that even a relatively flexible ethylene-vinyl acetate copolymer is far inferior to soft polyvinyl chloride.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a flexible medical tubing which is a non-polyvinyl chloride type and is highly practical.

[0004]

Means for Solving the Problems The gist of the present invention is to use an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer or an ethylene-methacrylic acid ester copolymer (A) (hereinafter sometimes simply referred to as (A)). A medical tube containing a composition comprising a low molecular weight organic ester plasticizer (B) (hereinafter sometimes simply referred to as (B)). Affinity between (A) and (B)
(EN) It is possible to provide a tube having excellent compatibility (which is considered to have an ester group in each case), and having high transparency and flexibility.

First, (A) will be described. Ethylene
A vinyl acetate copolymer (hereinafter referred to as EVA) is a polymer usually produced by a known method, but considering the interaction (affinity / compatibility) with the plasticizer (B), the vinyl acetate component content is 10 to 40. Wt% More preferably 13-35
% By weight. Also, due to the moldability, processability, mechanical properties of the molded product, etc.
MFR (melt flow rate) in g is 0.2 to 2
0 and more preferably 0.5 to 10 is selected. Also, ethylene-acrylic acid ester copolymer,
As the ethylene-methacrylic acid ester copolymer,
Ethylene-methyl acrylate copolymer (hereinafter referred to as EMA), ethylene-ethyl acrylate copolymer (hereinafter referred to as EEA), ethylene-methyl methacrylate copolymer (hereinafter referred to as EMMA) and ethylene-ethyl methacrylate copolymer (hereinafter referred to as EEMA). ) Is a typical example. These copolymers have similar reasons to EVA,
The content of acrylic acid ester or methacrylic acid ester component is 10 to 40% by weight, more preferably 13 to 35.
It is appropriate that the content is% by weight and the MFR (measured under the same conditions as EVA) is 0.2 to 20 and more preferably 0.5 to 10.

Next, a low molecular weight organic ester plasticizer (B)
Will be described. (B) refers to a low molecular weight organic ester compound used for plasticizing ordinary polyvinyl chloride materials, and includes phthalic acid ester, trimellitic acid ester, adipic acid ester, sebacic acid ester, azelaic acid ester, tartaric acid ester, and quenching ester. Among acid esters and malic acid esters, those having a molecular weight of 200 to 800, preferably 250 to 600, are preferable. If the molecular weight is too low, there is a problem of volatility, and if the molecular weight is too high, it may be difficult to move between the molecules of the polymer.As a result, the adhesive strength with other resin molded products may not be effective, so inconvenience may occur. Because there is. This is because the effect of improving adhesive strength is not obtained. Considering safety and hygiene, specific examples of desirable plasticizers include di-2-ethylhexyl phthalate, di-n-decyl phthalate, di-n-hexyl adipate, and di-2-ethylhexyl adipate. , Acetyl citrate tri-n-butyl, acetyl citrate tri-n-
Hexyl, butyryl citrate tri-n-butyl, butyryl citrate tri-n-hexyl, acetylmalic acid di-
n-hexyl, di-n-octyl acetylmalate, di-n-hexyl butyrylmalate, di-n-butyl diacetyl tartrate, di-n-hexyl diacetyl tartrate, di-n-butyl dibutyryl tartrate, di-butyryl tartrate di-
n-hexyl etc. are mentioned. Of course, the invention is not limited to these compounds.

The medical tube of the present invention comprises the composition of (A) and (B) (1) the tube is a single layer composed of the composition of (A) and (B), 2) The tube may be a multilayer body having at least one layer composed of the composition of (A) and (B) and at least one other polymer. In the case of (2), the mechanical properties (strength, elongation, etc.) of the tube, moldability, and blocking resistance (the composition of (A) and (B) becomes sticky when the proportion of (B) increases. (It may be easier to block)
Polyethylene and EV are used as the above-mentioned "other polymer" that is adopted for adjusting and improving
A, EEA, EMA, EMMA, propylene-based copolymer and the like can be used. Of note here is the "other polymer" thickness. That is, it is important to thin the layer of "another polymer" in order to realize flexibility which is one of the objects of the present invention. The specific thickness will be described later. The composition of the composition depends on whether the structure of the tube is (1) (single layer) or (2) (multilayer), the type of (A) or (B), the thickness of the tube, the thickness, and the use of the tube. The weight ratio of the composition (A) to the plasticizer (B) is more preferably 95: 5 to 60:40, and more preferably 9, though it depends on the above.
It is preferable to set it to about 2: 8 to 65:35.

The tube generally has an outer diameter of 3 to 20 mm, preferably 5 to 15 mm, and a wall thickness of 0.3 to 2 mm, more preferably 0.5 to 1.5 mm. Is good. In the case of the multi-layer of the above (2), it is appropriate that the thickness of the "other polymer" layer is suppressed to half or less of the total thickness, more preferably 1/3 or less.

The medical tube of the present invention is used as:
Examples include delivery of blood or its components, medium, buffer, infusion, peritoneal dialysate, and the like. In some cases, a so-called aseptic joining or "a method of interconnecting the first and second thermoplastic tubes in a direction transverse to the axis of each tube, as described, for example, in Japanese Patent Publication No. Sho 61-30582, is used. Cutting the tube using a cutting means having a cutting surface to form a continuous melt seal between the heated cutting surface and the cross section of each of the tubes, thereby providing a seal between the tube and the exterior. , And joining the respective melted ends of the tubes together to form a connection between the tubes while holding the seal. It is preferable to take a layered structure.

The tube of the present invention can be manufactured by a commonly known melt extrusion method using a tubular die. The extrusion temperature varies depending on the composition, but is generally 150 to 200 ° C. A heat-resistant agent, a light-resistant agent, a light-shielding agent, a pigment, etc. may be added within a range that does not impair the gist of the present invention. Also, roughening (embossing) the inner or outer surface of the tube and adding antiblocking agents / slip agents for the purpose of suppressing blocking during processing or use and improving operability. And so on.

Although the tube of the present invention can sufficiently withstand low temperature sterilization such as ethylene oxide gas sterilization, it has insufficient heat resistance against high pressure steam sterilization which is usually carried out at 100 to 130 ° C. In some cases radiation (electron beam,
It is preferable to perform heat resistance improvement treatment such as γ-ray) crosslinking and chemical crosslinking.

[0012]

The present invention will be described more specifically with reference to the following examples.

[1] Examples 1 to 13 and Comparative Examples 1 to 3 (Experimental Method) (1) Preparation of Raw Polymer and Plasticizer: The polymers and plasticizers shown in Table 1 were prepared.

(2) Preparation of composition: Polymers / plasticizers shown in Table 1 are appropriately selected and fed to a twin-screw melt-mixing extruder.
The strands that have been kneaded and extruded at 0 to 190 ° C are cooled with water.
It was cut and dried to obtain a pelletized composition.

(3) Preparation of tube: A polymer or composition shown in Table 1 or Table 2 is appropriately selected, and extruded at 160 to 180 ° C. from a die for tube for single layer or for multilayer, and 10 m / after cooling with water. Winding at a speed of minute, inner diameter 3.0mm
A tube with Φ and an outer diameter of 4.4 mmΦ was used.

[0016]

[Table 1]

[0017]

[Table 2]

(4) Measurement of tube flexibility: The tube obtained in (3) was used as an autograph DSS- manufactured by Shimadzu Corporation.
100, chuck distance 50mm, pulling speed 5mm
The initial elastic modulus was measured under the condition of / min and used as a measure of flexibility. Further, a polyvinyl chloride tube containing 40% by weight of di-2-ethylhexyl phthalate was similarly measured (Comparative Example 3).

(5) Evaluation of tube transparency: By visual observation.

(6) Heavy metal and eluate test: The tube obtained in (3) was tested according to the Japanese Pharmacopoeia General Test Method Infusion Plastic Container Test Method.

(7) Sterilization test: The tube obtained in (3) was sterilized with ethylene oxide gas at a temperature of 60 ° C. for 8 hours, and the appearance of the tube before and after sterilization was observed. The initial elastic modulus of the tube after sterilization was also measured by the same method as (4).

(Experimental Results) (1) All the sheets were manufactured smoothly, and as shown in Table 3, a single-layer or multi-layer tube containing the composition of (A) and (B) was made of soft poly It can be seen that it is comparable to a vinyl chloride tube. It was also confirmed that the transparency observed with the naked eye was good, and that heavy metals and eluates also cleared the standard.

(2) Almost no change in flexibility was observed before and after ethylene oxide gas sterilization (Table 3), and neither deformation nor change in transparency was observed.

[0024]

[Table 3]

[2] Examples 14 to 15 (Experimental Method) (1) Preparation of Electron Beam Irradiation Tube: Each tube having the constitution shown in Table 4 prepared by selecting the polymer or composition shown in Table 1 or 2 On the other hand, an electron beam of about 7 Mrad was irradiated by an electron beam irradiation device EPS-750 manufactured by Nisshin High Voltage Co., Ltd.

(2) High-pressure steam sterilization treatment: The tube obtained in (1) was subjected to high-pressure steam sterilization treatment at a temperature of 115 ° C. for 30 minutes.

(3) Evaluation: The initial elastic modulus of the tube before and after electron beam irradiation and before and after high-pressure steam sterilization, observation of the state of transparency, and heavy metal / eluate test were carried out by the above-mentioned method.

(Experimental Results) (1) Almost no change was observed in the transparent appearance of the tube before and after electron beam irradiation and before and after high-pressure steam sterilization.

(2) As Table 4 shows the initial elastic modulus at each stage, it was confirmed that a tube having a high flexibility was obtained.

(3) It was also confirmed that the heavy metal / eluate test was cleared at any stage.

[0031]

[Table 4]

[0032]

As described above, the present invention skillfully applies the softening effect due to the affinity and compatibility of the ester group-containing polyethylene polymer and the low molecular weight organic ester plasticizer to produce soft polyvinyl chloride. It is an alternative medical tube that has been realized, and its industrial value is extremely high in combination with the ease of manufacturing.

Claims (8)

[Claims] 1. A medical tube containing a composition comprising an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer or an ethylene methacrylic acid ester copolymer and a low molecular weight organic ester plasticizer. 2. The content of vinyl acetate component in the ethylene-vinyl acetate copolymer, the content of acrylic acid ester component in the ethylene-acrylic acid ester copolymer, and the content of methacrylic acid ester component in the ethylene-methacrylic acid ester copolymer are 10 to 40% by weight, respectively. %, The medical tube according to claim 1. 3. The medical tube according to claim 1, wherein the content of the low molecular weight organic ester plasticizer in the composition is 5 to 40% by weight. 4. The ethylene-acrylic acid ester copolymer is an ethylene-methyl acrylate copolymer or an ethylene-ethyl acrylate copolymer,
The medical tube according to claim 1, wherein the methacrylic acid ester copolymer is an ethylene-methyl methacrylate copolymer or an ethylene-ethyl methacrylate copolymer. 5. The plasticizer is one or more selected from the group consisting of phthalic acid ester, trimellitic acid ester, adipic acid ester, sebacic acid ester, azelaic acid ester, tartaric acid ester, citric acid ester and malic acid ester. The medical tube according to claim 1, wherein: 6. The medical tube according to any one of claims 1 to 5, which is a multilayer body in which at least one layer of the tube is formed from the composition. 7. A polyethylene, EVA, EEA, E layer other than the layer which is not formed of the composition among the layers constituting the multilayer body.
The medical tube according to claim 6, which is formed of one kind or two or more kinds selected from the group of MA, EMMA and propylene-based copolymer. 8. The medical tube according to claim 6, wherein the tube has a three-layer structure including an inner layer, an intermediate layer and an outer layer, and the intermediate layer is formed of the composition.