JP2005006777A - Tube for medical use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube for medical use which is easily adapted at the time of liquid feeding and to which air bubbles are not stuck easily by not containing a plasticizer harmful to a living body and improving the wettability of a surface, or to provide the tube for the medical use for which the air bubbles are removed by being easily detached and made to flow to the downstream even when the air bubbles are stuck to the surface. <P>SOLUTION: For the tube for the medical use, a base material composed of a synthetic high polymer has a reactive group at least in a part of the components and hydrophilicity is improved by introducing a hydroxyl group by utilizing at least a part of the reactive group. Further, for the tube for the medical use, the hydroxyl group is introduced more on a base material surface than inside the base material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２５】
【発明の効果】
上記構成の医療用チューブは、チューブ内腔に液体を流した際、速やかに濡れ、気泡が下流に流れることで、プライミングが容易となる。また、通液の際、液体中の溶存気体が気泡として発生しても、気泡が付着しにくくなっており、結果的に輸液・輸血ラインに接続した装置の気泡センサーや人体に影響を及ぼすような気泡の発生が認められない。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medical tube having appropriate flexibility in a circuit used for infusion or blood transfusion.
[0002]
[Prior art]
Conventionally, di-2 ethylhexyl phthalate (DEHP) plasticized PVC is often used in circuits used for transfusion and blood transfusion. However, PVC has a problem of elution of its plasticizer DEHP, and there are drugs that prohibit the use of DEHP plasticized PVC such as fat emulsion and taxol, and there are some products using soft polyolefins that do not contain plasticizer. The
[0003]
However, since these polyolefins are highly hydrophobic, once the liquid flows in the tube, once the bubbles generated from the dissolved gas in the liquid adhere to the tube, it becomes difficult for the bubbles to flow downstream. Difficulties and attached air bubbles may be detected by air bubble sensors such as infusion pumps, causing problems.
[0004]
[Patent Document 1]
JP-A-1-250265
[Problems to be solved by the invention]
An object of the present invention is to provide a medical tube that does not contain a plasticizer that suppresses the drawbacks of the above-described prior art, that is, the adhesion of bubbles.
[0006]
[Means for Solving the Problems]
In the present invention, the above-described problems can be solved by the method described below or a medical tube obtained by the method. That is, according to the first aspect of the present invention, a base material made of a synthetic polymer has a reactive group in at least a part of its constituent components, and a hydroxyl group is introduced using at least a part of the reactive group. It is related with the medical tube characterized by having improved hydrophilicity by.
[0007]
Furthermore, the second of the present invention is to treat at least a part of the reactive group by treating the surface of the base material of the synthetic polymer having a reactive group at least part of its constituents with an acid or alkali. The present invention also relates to a method for modifying the surface of a medical tube, wherein the surface is substituted with a hydroxyl group.
[0008]
In the present invention, the reactive group is hydrolyzed by treating the reactive group (carboxyl group, isocyanate group, amino group, amine, ester, and other reactive groups) with an acid or alkali, Substituted with a hydroxyl group. This substitution is particularly ubiquitous on the substrate surface and does not penetrate deep into the interior. Thereby, the hydrophilicity of the substrate surface is improved while maintaining (moderately) the physical properties of the substrate such as flexibility and transparency.
[0009]
By improving the hydrophilicity, bubbles are prevented from adhering when the tube is passed through. In addition, the improvement of wettability according to the present invention is that there is no additive bloom or bleed as in the method of adding a second component such as a low-molecular surfactant to the polymer in order to introduce a functional group chemically. As a medical application, safety is high.
[0010]
The present invention can take various embodiments as described below based on the above-described configuration, and can obtain unique effects.
[0011]
As one example, in the medical tube, introduction of the hydroxyl group is more on the surface of the base material than in the base material. Thereby, the physical property change of the base material as described above can be suppressed.
[0012]
Alternatively, in the medical tube, a reactive group of the synthetic polymer is a carboxyl group, and at least a part of the carboxyl group is substituted with a hydroxyl group. Hydrophilicity can be improved very easily by acid or alkali treatment. Moreover, the safety of the reactive group itself is high.
[0013]
Further, in the medical tube, the tube material is made of an ethylene-vinyl acetate copolymer (hereinafter also referred to as EVA), and the surface of the base material with improved hydrophilicity has a contact angle of 75 degrees or less. When used, the substrate is excellent in flexibility, processability, and transparency, and the tube surface (lumen) is easily wetted, so that bubbles are difficult to adhere.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The surface treatment method of the present invention is to convert the carboxyl group on the EVA surface into a hydroxyl group by hydrolyzing it. As the hydrolysis method, alkali hydrolysis is particularly desirable in view of its effect. The pH adjustment of the treatment solution is not particularly limited, such as KOH and NaOH, but the carboxyl group on the EVA surface is efficiently converted to a hydroxyl group at a pH of 7.0 to 12, a treatment temperature of 25 to 70 ° C., and a treatment time of 5 to 480 minutes. . Preferably, the pH is 7.5 to 9.5, the treatment temperature is 40 to 50 ° C., and the treatment time is 60 to 180 minutes.
[0015]
Under the above conditions, the substitution ratio of the carboxyl group to the hydroxyl group, that is, the saponification degree is 5 to 25%. Moreover, since the site | part to which saponification is performed will be about 8 to 15% of tube thickness by said conditions, hydrophilicity can be improved, maintaining the physical property of a base material.
[0016]
If the pH or the treatment temperature is lower than this and the treatment time is short, the conversion to a hydroxyl group is not sufficient, and appropriate wettability may not be obtained. In addition, when the pH and processing temperature are high and the processing time is long, the conversion to the hydroxyl group proceeds to the inside of the tube, and the tube becomes hard or the liquid penetrates to the inside of the tube when passing, impeding transparency of the tube To do.
[0017]
【Example】
1. Preparation of sample (1) Example EVA (Ultrasen YX11C, Tosoh Corporation) using a 30 mm extrusion molding machine (L / D = 26) at a molding temperature of 170 to 180 ° C., inner diameter × outer diameter = 2.5 A x3.8 mm tube was molded. An alcohol solution of potassium hydroxide (1M ethanolic potassium hydroxide, Wako Pure Chemical Industries, Ltd.) adjusted to 50 ° C. was circulated in the lumen of the obtained EVA tube for 1 hour and 3 hours. And Example (2).
[0018]
(2) Comparative Example The EVA tube molded in the example was treated for 24 hours in the same manner as in the example, and the tube was designated as comparative example (1). An untreated EVA tube was used as Comparative Example (2).
[0019]
2. Experiment (1) Measurement of degree of saponification The degree of saponification of the above tube was measured by the following method. Add 30 ml of 0.05 mol / L sulfuric acid aqueous solution to 1.0 gram of each tube and shake. Thereafter, a phenolphthalene solution was added as an indicator, and titration was performed with a 0.1 mol / L sodium hydroxide aqueous solution to measure the ratio of vinyl alcohol (Binyl-OH group) in the EVA tube, that is, the degree of saponification.
[0020]
(2) Hydrophilic evaluation 1
The introduction of hydroxyl groups in the tube, that is, water wettability was evaluated by measuring the contact angle of the lumen surface of the tubes prepared in Examples (1) and (2) and Comparative Examples (1) and (2). . It was suggested that the longer the treatment time with Examples (1) and (2) and Comparative Example (1), the smaller the contact angle and the better the water wettability. The untreated comparative example (2) had the highest contact angle.
[0021]
(3) Hydrophilic evaluation 2
The initial elastic modulus when the tubes prepared in Examples (1) and (2) and Comparative Examples (1) and (2) were pulled at a speed of 50 mm / h with a tensile tester was determined in Example (1). , (2) showed almost the same value as Comparative Example (2), which was untreated EVA, and maintained flexibility, but Comparative Example (1) showed a high value, and the tube was hard.
[0022]
(4) Hydrophilic evaluation 3
After constructing an infusion set with the tubes prepared in Example (1), (2) and Comparative Examples (1), (2), after sterilization with ethylene oxide gas, connect a saline bag by a conventional method to reduce the drop to 1 m Then, infusion was performed at a drip rate of 80 mL / h using a roller-type flow controller. When the tube was visually observed, almost no bubbles were observed in the tubes of Examples (1), (2) and Comparative Example (1), but the infusion time elapsed in the tube of Comparative Example (1). At the same time, the tube became cloudy.
[0023]
Further, when the infusion was stopped with a roller-type flow controller, in Comparative Example (1), the tube was too hard to be completely stopped. In the tube of Comparative Example (2), air bubbles were noticeably observed in the vicinity of the connecting portion of the drip tube and the tube and the lower part of the flow rate controller.
[0024]
[Table 1]

[0025]
【The invention's effect】
The medical tube having the above-described configuration is easily primed when a liquid is allowed to flow through the tube lumen, so that the air bubbles quickly flow downstream. In addition, even if dissolved gas in the liquid is generated as a bubble when liquid is passed, it is difficult for the bubble to adhere, and as a result, it may affect the bubble sensor of the device connected to the infusion / transfusion line and the human body. Generation of bubbles is not observed.

Claims (6)

The base material made of a synthetic polymer has a reactive group in at least a part of its constituent components, and has improved hydrophilicity by introducing a hydroxyl group using at least a part of the reactive group. A characteristic medical tube. The medical tube according to claim 1, wherein the introduction of the hydroxyl group is more on the surface of the base material than in the base material. The medical tube according to claim 1, wherein a reactive group of the synthetic polymer is a carboxyl group, and at least a part of the carboxyl group is substituted with a hydroxyl group. 4. The medical tube according to claim 3, wherein the tube material is a medical tube made of an ethylene-vinyl acetate copolymer, and the surface of the base material with improved hydrophilicity has a contact angle of 75 degrees or less. The substrate surface of a synthetic polymer having a reactive group in at least a part of its constituent components is treated with an acid or an alkali, and at least a part of the reactive group is hydrolyzed to be substituted with a hydroxyl group. To improve the surface of a medical tube. The method for modifying a surface of a medical tube according to claim 5, wherein the reactive group is a carboxyl group, and the medical tube is made of an ethylene-vinyl acetate copolymer, and the medical tube is alkali-treated.