JPH0350914Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a composite rubber stopper for medical infusions.

[Conventional technology]

Nowadays, many infusion bottles are made of synthetic resin, so rather than using the rubber stopper independently, it is used as a cap inside a synthetic resin cap case, and this cap is integrated into the bottle mouth. Usually, it is heat sealed.

Conventionally, this type of rubber stopper has been made of highly elastic materials such as natural rubber (NR), isoprene rubber (IR), and butyl rubber (IIR), which have a so-called self-sealing property, because it is necessary to consider the possibility of contact with the liquid inside the container. Rubber stoppers such as butadiene rubber (BR), which have poor self-sealing properties but are good in terms of non-leaching properties, have been used instead of rubber stoppers that have excellent properties.

[The problem that the idea attempts to solve]

However, as mentioned above, rubber stoppers such as BR lack self-sealing properties, making them undesirable in terms of sealing performance.Especially, when a syringe needle is inserted directly through them, they tend to leak, and they are also undesirable in terms of cost. Therefore, it was not necessarily satisfactory as an infusion rubber stopper used for this type of medical treatment.

In this regard, an attempt was made to solve the elution problem by installing a rubber stopper such as NR inside the cap case and forming an elution-resistant synthetic resin thin film as part of the cap case on the parts that come into contact with the liquid. However, since the film is formed as a part of the cap case and is separate and independent from the rubber plug such as NR, it is not possible to achieve the preferable self-sealing characteristic of the rubber plug such as NR. However, it was not possible to effectively demonstrate its properties, and merely provided the effect of elution resistance, that is, hygiene. Furthermore, since the rubber stopper of NR etc. is independent of the cap case and does not come into close contact with it, contact between the rubber stopper and the liquid in the container is unavoidable during needle pricking, and mechanical production is also difficult due to its structure. There is also a method of integrally molding a rubber plug such as NR inside a synthetic resin cap case, but the self-sealing power of a rubber plug such as NR is effectively exerted because it is constrained by a rigid cap case. The problem was that it couldn't be done.

The purpose of this invention is to provide a rubber stopper for infusions that is highly hygienic, has excellent self-sealing properties, is resistant to leakage even if it is penetrated by a syringe needle, and is highly productive.

[Means to solve the problem]

As a result of intensive consideration of the above issues, we developed a composite rubber with a laminated structure in which the rubber stopper inside the synthetic resin cap case is coated with a thermoplastic elastomer film layer around a self-sealing rubber core. Developed a stopper.

In other words, a thermoplastic elastomer film layer with elution resistance and some elasticity is used on the outer side of the rubber stopper, which must be considered in contact with liquid, and a layer of thermoplastic elastomer with excellent self-sealing properties is used inside the stopper. By integrating the rubber core body of NR etc. by insert molding etc., we ensure elution resistance on the external side and
We adopted a configuration that ensures self-sealing on both the exterior and interior sides.

Therefore, in order to have good elution resistance and improve self-sealing properties, it is preferable that the thickness of the thermoplastic elastomer film layer be as thin as possible, and that the thickness of the rubber core such as NR be thick. If the thickness of the coating layer is made too thin, the rubber of the rubber core will be damaged when punctured by a needle, and the coating layer itself will also be prone to crack failure. On the other hand, if it is too thick, the thermoplastic elastomer, which is more rigid than rubber, will be affected and leak when punctured with a needle, so there is a certain limit to the thickness of the coating layer and the rubber core. Admitted. A preferable range is that, based on a rubber core having a thickness of 1 to 4 m/m, the thickness of the film layer on the liquid contact side is 0.5 m/m.
~1m/m. Although there is no particular limitation on the upper and side surfaces of the film layer, it is desirable that the thickness be 0.5 to 2 m/m.

Various thermoplastic elastomers can be used, such as styrene elastomers and olefin elastomers, but styrene elastomers are particularly preferred. In addition, the hardness of the film layer is JISA hardness, considering cracks during needle stick and liquid leakage due to rigidity.
A desirable range is 35-60.

As mentioned above, the rubber material that can be used for the rubber core has a structure in which the rubber core is surrounded by a film layer that is resistant to elution, so it can be used not only for butadiene rubber but also for rubbers with poor elution resistance. However, it is preferable to use rubber with excellent self-sealing properties such as NR, IR, and IIR.

Various methods can be used to cover the rubber core body with the coating layer according to this invention, but from the viewpoint of manufacturing efficiency, it is preferable to use insert molding or injection molding.

[Effect]

Since this idea is as described above, the thermoplastic elastomer film layer exhibits elution resistance, and the composite rubber as a whole exhibits excellent self-sealing properties due to the synthetic action of the rubber core and the film layer. .

Therefore, the composite rubber stopper according to this invention can be heat-sealed directly to the opening of a synthetic resin infusion container, and even if the internal rubber material of the rubber core part is easily eluted, there will be no elution. Furthermore, since the self-sealing property is good, the sealing property is good, and no liquid leakage occurs even when punctured with an injection needle.

Furthermore, since the rubber stopper of this invention is covered with a thermoplastic elastomer film layer, it can be easily molded and has excellent productivity even when it is installed inside a cap case.

Furthermore, whether it is integrally molded into the capsule case or heat-sealed directly to the container mouth, the rubber core is integrated with the outer elastomer film layer and is in close contact with it.
There is no risk that the internal rubber material will come into contact with the liquid in the container, and since the rubber core is joined to the cap case with an elastomer film layer interposed, the rubber core is elastic. This means that it is continuously connected to the rigid cap case through a slightly rigid film layer, and even if it is a rubber stopper that is integrated into this type of cap case,
The influence of the rigidity of the capsule case can be avoided as much as possible, and sufficient self-sealing performance can be ensured.

〔Example〕

FIG. 1 is an enlarged cross-sectional view of a main part showing a state in which a composite rubber stopper according to an embodiment of this invention is used.

In the figure, 1 is a styrene-based thermoplastic elastomer coating layer that constitutes the outer part of this composite rubber stopper, and 2 is a rubber core body made of NR material with high self-sealing properties and integrally molded inside this coating layer. It is.

The thickness of the rubber core body part 2 is 1 m/m, and the thickness of the coating layer 1 is 0.5 m/m on the liquid contact side, side side, and top side.
The thickness of the composite rubber stopper is 2 m/m. The JIS A hardness of film layer 1 is 40.

When the composite rubber stopper according to this example was directly fitted into the mouth of an infusion container into which liquid was injected,
It was observed that there was no liquid leakage and the sealing performance was good, and it was confirmed that no liquid leakage occurred even when punctured with a syringe needle. Even in the rubber elution test, the rubber core body part 2
No elution of NR material was confirmed.

[Effects of the invention] As described above, this invention has a laminated structure in which a rubber plug is housed inside a synthetic resin cap case and a thermoplastic elastomer film layer is coated around a rubber core body having self-sealing properties. This is a composite rubber stopper for infusions, which is characterized by high hygiene properties, and depending on the rubber material used for the rubber core, it is economical, and has excellent self-sealing properties. Even if the injection needle is penetrated, the liquid does not easily leak, and furthermore, it has extremely high productivity, which is an unprecedented effect.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of the composite rubber stopper according to the invention. 1... Film layer, 2... Rubber core body part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A rubber plug housed inside a synthetic resin cap case has a laminated structure in which a self-sealing rubber core body is covered with a thermoplastic elastomer film layer. A composite rubber stopper for infusions, which is characterized by: (2) The thickness of the coating layer is 0.5 to 1 m/m on the liquid contact side for the rubber core body having a thickness of 1 to 4 m/m.
2. The composite rubber stopper for infusion according to claim 1, wherein m. (3) The composite rubber stopper for infusion according to claim 1, wherein the film layer has a JIS A hardness of 35 to 60. (4) The composite rubber stopper for infusion according to claim 1, 2 or 3, wherein the rubber core portion is made of rubber having self-sealing properties such as NR, IR, IIR.