JPH067851B2 - Liquid container and method of manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a medical liquid container and a manufacturing method thereof. In particular, the present invention relates to a liquid container for medical use that can withstand high-pressure steam sterilization used in a closed medical system and can be easily crushed (flexible), and a manufacturing method thereof.

[Prior Art] In recent years, in medical treatment such as infusion, a closed system has been used in order to prevent the content liquid from coming into contact with the outside world. The medical liquid container used in this closed system is required to discharge the content liquid due to gravity, the structure of the container, and the flexibility of the material of the container. In addition, this type of medical liquid container needs to have heat resistance to withstand high-pressure steam sterilization in order to sterilize the content liquid. Further, it is preferably made of a transparent material so that the content liquid can be monitored from the outside. For this purpose, soft polyvinyl chloride and ethylene-vinyl acetate copolymers have been mainly used as materials for medical liquid containers. In addition, the present inventor is
There is also a medical liquid container using a polyolefin resin by the method disclosed in JP-A No. 63-287728.

[Problems to be Solved by the Invention] Since soft polyvinyl chloride contains a large amount of plasticizer, the plasticizer may be eluted in the content liquid, and is regarded as a problem in terms of safety. The ethylene-vinyl acetate copolymer may be deacetic acid during molding and may be eluted in the content liquid, and as it is, does not have heat resistance that can withstand high-pressure steam sterilization. Therefore, the ethylene-vinyl acetate copolymer has to be crosslinked by irradiation of radiation so as to have a predetermined heat resistance, and there is a problem that an additional step is required for manufacturing the container. Therefore, a polyolefin-based resin, which has high safety and excellent physical properties and is inexpensive, is considered promising.

However, it has been extremely difficult to produce a desired medical liquid container using such a polyolefin resin. Generally, polyolefin resins do not generate enough heat to be fused even when a high-frequency electric field is applied because of their low dielectric loss, so unlike vinyl chloride resins, high-frequency sealing is not possible. Therefore, for example, when a medical liquid container is to be formed from two polyolefin sheets, the sheets are overlapped and a predetermined portion is welded by impulse sealing or heat sealing. However, unlike high frequency seals, impulse seals
Since it is difficult to weld in a complicated shape, and because heat sealing is external heating, it is difficult to weld materials with different wall thicknesses on the outer circumference of a cylinder, etc. The small-diameter opening provided at the upper end could not be formed successfully.

On the other hand, a method of manufacturing a polyolefin medical liquid container by a hollow molding method capable of integrally forming such a small-diameter opening portion and a container portion is also conceivable. However, the conventional medical liquid container obtained in this way is obtained. Is less flexible, is less likely to be crushed because the container part has a cylindrical shape and the container peripheral part is likely to have a three-dimensional structure, and the wall thickness in the vicinity of the lower peripheral part of the container part is less than that of the central part. Also, the thickening hinders the action of discharging the liquid content filled in the liquid container. Therefore, in the conventional liquid container for medical use by the hollow molding method, the content liquid is not discharged quickly and completely in the closed system.

[Means for Solving Problems] An object of the present invention is to provide a medical liquid container made of a polyolefin resin, which is suitable as an infusion bag or the like. As a result of various studies on the shape and manufacturing method of a medical liquid container, an opening of a predetermined shape at the upper end, followed by a flat-shaped container and a suspension opening at the lower end, The inventors have found that a suitable liquid container for medical use can be obtained by hollow molding so that the thickness of the wall is thinner in the vicinity of the lateral peripheral portion and the lower peripheral portion than in the central portion, and the present invention has been achieved. Is.

That is, the present invention has a density of 0.915 to 0.930 g / cm ³ and an Orzens rigidity is formed of a polyolefin resin of 4000 kg / cm ² or less, an opening at the container part and its upper end and a suspension opening at the lower end. A medical flexible liquid container having a feature that it is formed by hollow molding, the container portion is flat, and the thickness of the wall of the container portion is thinner in the vicinity of the side peripheral edge portion and the lower peripheral edge portion than the central portion. Is a medical flexible liquid container used in a closed system. By hollow molding using a specific polyolefin resin, the container part is flat and the thickness of the side peripheral edge and the lower peripheral edge is thinner than the thickness of the central part.
While maintaining the excellent moldability (especially the integral moldability of the opening and the container), which is an advantage of the hollow molded container, the problem of structural collapse, which was the problem, has been largely resolved, and the container has been drained. Since the liquid is easily crushed, the drainage speed is fast and constant, and the residual liquid amount can be significantly reduced. That is, it is desired that the air portion in the container is as small as possible,
In a closed system such as an infusion container that discharges the liquid from a sealed and sealed medical container to the outside of the container, drainage with a minimum amount of air (a level that can read the liquid level) Can be done quickly and completely. Further, by using the polyolefin resin, it is possible to secure sufficient heat resistance and flexibility and to secure excellent safety.

Further, the present invention, a polyolefin resin having a density of 0.915 to 0.930 g / cm ³ and an Orzens rigidity of 4000 kg / cm ² or less,
Using a mold that has an opening at the upper end, followed by a flat-shaped container part, and a suspension port at its lower end, the thickness of the container wall is near the side peripheral edge and the lower peripheral edge from the central part. This is a method for manufacturing a medical flexible liquid container used in a closed system, which is characterized in that hollow molding is performed so that the portion becomes thinner. By the hollow molding method, it becomes possible to integrally form the container part such as the opening part of the container,
Also, by adjusting the thickness of the wall of the container so that the peripheral portion is thinner than the central portion, the medical container having excellent drainage characteristics can be manufactured.

[Operation] Next, the present invention will be specifically described with reference to the drawings.

As shown in FIGS. 1 and 2 (a) and (b),
The medical liquid container 1 of the present invention is a blow-molded product of a polyolefin-based resin having a small-diameter opening 2 at its upper end, a container part 3 following it, and a suspension port 4 at its lower end. As shown in FIG. 2 (b), by making the shape of the cross section of the container 3 when cut along a plane perpendicular to the central axis of the opening 2 oval, the container 3 is easily collapsed. .
Further, by making the thickness of the wall of the container portion 3 thinner in the vicinity of the side peripheral edge portion 6 and the lower peripheral edge portion 7 than in the central portion 5, the container portion 3 is more likely to be crushed and the content liquid The discharge can be smoothed and the residual liquid amount can be reduced.

The material forming the medical liquid container 1 of the present invention has a density
It is a polyolefin resin with 0.915 to 0.930 g / cm ³ and Orzen's rigidity of 4000 kg / cm ² or less. Density is 0.930g / c
When polyolefin resin with m ³ or more or Olsen rigidity of 4000 kg / cm ² or more is used, the liquid container is hard and difficult to be crushed, so that the content liquid cannot be discharged smoothly. In addition, polyolefin resins with a density of 0.915 g / cm ³ or less have poor heat resistance and cannot withstand high-pressure steam sterilization. As a polyolefin resin, linear low density polyethylene (LLDP
E) is preferred. LLDPE is a copolymer of ethylene and α-olefin, where α-olefin is butene-1 having 4 carbon atoms, 4-methylpentene-1 having 6 carbon atoms, and 8 carbon atoms.
Octene-1 and so on. Further, a liquid container using LLDPE in which α-olefin is 4-methylpentene-1 and octene-1 is preferable. That is, LLDPE having α-olefins of 4-methylpentene-1 and octene-1 is flexible and has good transparency among LLDPEs having the same heat resistance, and is suitable for a liquid container for medical use.

The thickness of the container wall of the medical liquid container 1 of the present invention can be 0.05 to 0.35 mm, preferably 0.1 to 0.3 mm. More specifically, it is preferable that the thickness in the vicinity of the side peripheral portion 6 and the lower peripheral portion 7 is 0.1 to 0.15 mm, and the thickness in the vicinity of the central portion 5 is 0.2 to 0.3 mm. The conventional soft polyvinyl chloride container or ethylene-vinyl acetate copolymer container has a wall thickness of 0.35 to 0.45 mm in order to obtain sufficient water vapor permeation resistance and strength. Is
Since it has excellent resistance to water vapor permeation and strength, it can be thinned in this way.

Another embodiment of the medical liquid container of the present invention is shown in FIGS. 3 and 4 (a) and (b). A blow molded product is produced in the same manner as in the first embodiment, and the side peripheral edge portion 36 of the container portion 33 is heat-welded. That is, as shown in FIG. 4 (b), by making the shape of the cross section of the container 33 when cut along a plane perpendicular to the central axis of the opening 32 into a boat shape, It is easy to collapse. Side peripheral edge 36
By heat-sealing, the container portion 33 is likely to be crushed, the inner surfaces of the central portion 35 are easily brought into contact with each other, and the residual liquid amount can be further reduced.

Furthermore, another embodiment of the medical liquid container of the present invention is
Shown in the figure. A blow-molded product is produced in the same manner as in the first embodiment, and the shoulder peripheral portion 48 of the container portion 43 is pressed and heat-welded. The opening 42 of the medical liquid container 41 needs a certain degree of hardness so that the rubber stopper attached to the container can easily and accurately penetrate the bottle needle of the infusion set. It is also necessary to increase the wall thickness.
Therefore, the wall of the blow-molded product near the shoulder portion becomes thicker and harder to be crushed. Therefore, the amount of residual liquid after discharging the content liquid increases. By pressing and heat-welding the shoulder peripheral portion 48, the container portion 43 is easily crushed, and the amount of residual liquid can be reduced.

The medical liquid container of the present invention having such a configuration,
It is manufactured as follows. As shown in FIG. 6, it has a small diameter opening 52 at the upper end, a flat container portion 53 following it, and a suspension opening 54 at the lower end, and the wall thickness of the container portion 53 is closer to the center than the central portion. A blow-molded product 51 of a polyolefin resin having a density of 0.915 to 0.930 g / cm ³ and an Orsen rigidity of 4000 kg / cm ² or less is molded so that the peripheral edge portion and the lower peripheral edge portion are thinner. That is, a hollow molten polyolefin-based resin is taken out from a die and loaded into a mold having an opening at the upper end, a flat-shaped container part following it, and a suspension opening part at the lower end, and subsequently the mold. When air is blown from the upper part of the container to form a container, the thickness of the hollow molten resin discharged from the die is adjusted so that the thickness of the wall of the container part is closer to the side peripheral part than the central part and the lower peripheral part. It can be molded so that it becomes thinner. This blow-molded product 51 can be used as the medical liquid container 1 of the present invention. Further, a portion 56 near the side peripheral edge of the container portion 53 of this blow-molded product is welded by an external heating device. After welding, the outside portion of the side peripheral edge portion 56, which is an unnecessary portion, is cut off to manufacture the medical liquid container 31 of the present invention.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 A linear low-density polyethylene (trade name: Moretec, manufactured by Idemitsu Petrochemical Co., Ltd., density: 0.920 g / cm ³ , Olsen rigidity: 2400 kg / cm ² ) has an opening of a predetermined shape and a flat container part. A blow molded article having a suspension opening and a suspension opening was obtained. The wall thickness near the center of the container of this blow molded product is 300 μm.
The wall thickness in the vicinity of the side peripheral edge and the lower peripheral edge was 150 μm. The shape of the cross section of the container is
The ellipse had a major axis of 120 mm and a minor axis of 15 mm. This blow molded product was used as an infusion container.

550 ml of water (the amount of air in the container was 25 ml) was poured into this container, the opening was sealed with a linear low-density polyethylene film, and a rubber stopper was attached.

This infusion container was autoclaved at 115 ° C for 40 minutes.
No significant deformation was observed after sterilization.

In addition, the bottle needle of the infusion set is pierced through the opening according to the usual infusion procedure, and the height from the opening to the infusion needle is 70
It was set to cm and adjusted with a clamp so that the amount dropped was about 50 ml / min. When the relationship between the amount of drainage and time was measured, the amount of drainage was almost proportional to time. In addition, the amount of residual liquid after drainage was 7 ml, which was very small.

Example 2 Linear low-density polyethylene (trade name: Ultozex,
A blow molded product having an opening of a predetermined shape, a flat container portion and a suspended opening portion was obtained from Mitsui Petrochemical Co., Ltd., density: 0.930 g / cm ³ , Olsen rigidity: 3500 kg / cm ² . The thickness of the wall near the center of the container of this blow molded product is 200
In μm, the wall thickness in the vicinity of the side peripheral edge and the lower peripheral edge was 100 μm. The shape of the cross section of the container was elliptical with the major axis 120 mm and the minor axis 15 mm. This blow molded product was used as an infusion container.

550 ml of water (the amount of air in the container was 25 ml) was poured into this container, the opening was sealed with a linear low-density polyethylene film, and a rubber stopper was attached.

This infusion container was autoclaved at 115 ° C for 40 minutes.
No significant deformation was observed after sterilization.

In addition, the bottle needle of the infusion set is pierced through the opening according to the usual infusion procedure, and the height from the opening to the infusion needle is 70
It was set to cm and adjusted with a clamp so that the amount dropped was about 50 ml / min. When the relationship between the amount of drainage and time was measured, the amount of drainage was almost proportional to time. Also, the amount of residual liquid after the completion of drainage was very small at 5 ml.

Comparative Example 1 Linear low-density polyethylene (trade name: Moretech, manufactured by Idemitsu Petrochemical Co., Ltd., density 0.935 g / cm ³ , Olsen rigidity:
A container for infusion was prepared in the same manner as in Example 1 at 4600 kg / cm ² ).

550 ml of water (the amount of air in the container was 25 ml) was poured into this container, the opening was sealed with a linear low-density polyethylene film, and a rubber stopper was attached.

This infusion container was autoclaved at 115 ° C for 40 minutes.
No significant deformation was observed after sterilization.

However, according to the usual infusion procedure, the bottle needle of the infusion set is penetrated into the opening, and the height from the opening to the infusion needle is adjusted.
It was 70 cm, adjusted with a clamp so that the amount dropped was about 50 ml / min, and the relationship between the amount of drainage and time was measured.
The drainage volume decreased with time. Furthermore, the residual liquid volume after the drainage was large at 60 ml.

Comparative Example 2 Linear low density polyethylene (trade name: Moretec, manufactured by Idemitsu Petrochemical Co., Ltd., density 0.920 g / cm ³ , Olsen rigidity:
2400 kg / cm ³ ) was obtained as a blow-molded product having an opening of a predetermined shape, a substantially cylindrical container part, and a suspension port. The wall thickness of the container part of this blow molded product is almost uniform over the entire 300
μm, and the wall thickness near the lower peripheral edge is 400 μm
It was m. The shape of the cross section of the container is 85 mm in diameter.
The shape was close to a circle of mm. This blow molded product was used as an infusion container.

550 ml of water (the amount of air in the container was 25 ml) was poured into this container, the opening was sealed with a linear low-density polyethylene film, and a rubber stopper was attached.

This infusion container was autoclaved at 115 ° C for 40 minutes.
No significant deformation was observed after sterilization.

However, according to the usual infusion procedure, the bottle needle of the infusion set is penetrated into the opening, and the height from the opening to the infusion needle is adjusted.
It was 70 cm, adjusted with a clamp so that the amount dropped was about 50 ml / min, and the relationship between the amount of drainage and time was measured.
The drainage volume decreased with time. Furthermore, the amount of residual liquid after drainage was very large at 150 ml.

[Effects of the Invention] As described above, the liquid container of the present invention has the following advantages.

Since the opening portion, the container portion, and the suspension opening portion can be formed by integral molding, manufacturing is easy.

Since the material is a polyolefin resin, it does not contain components with high elution properties such as plasticizers, and is highly safe.

Has heat resistance to withstand high-pressure steam sterilization.

Despite being a hollow molded container, it is a container that can be easily crushed, so it can be suitably used for a closed system. That is, in a closed system such as an infusion container that discharges the liquid from a container filled with a liquid and sealed while keeping the closed state, even if the air part inside the container is small, Since it is easily crushed, the drainage speed is constant and the residual liquid amount can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a medical liquid container of the present invention, FIG. 2 (a) is a vertical sectional view taken along the line IIa-IIa of the same embodiment, and FIG. 2 (b) is the same embodiment. IIb-IIb cross-sectional view, FIG. 3 is a front view showing a second embodiment of the medical liquid container of the present invention, FIG. 4 (a) is a vertical cross-sectional view of IVa-IVa of the same embodiment,
FIG. 4 (b) is a transverse sectional view taken along the line IVb-IVb of the same embodiment, FIG. 5 is a front view showing a third embodiment of the medical liquid container of the present invention, and FIG. 6 is a medical view of the second embodiment. FIG. 8 is a front view showing a state in which the vicinity of the side peripheral edge portion of the blow-molded product for producing the liquid container for welding is welded. 1, 31, 41 ... Liquid container, 2, 32, 42, 52 ... Opening part, 3, 33, 43 ... Container part, 4, 34, 44, 54
... Suspension port parts 5, 35 ... Central part of liquid container, 6, 36, 4
6 ... Side peripheral edge of liquid container, 7, 37, 47 ... Lower peripheral edge of liquid container, 48 ... Perimeter edge of liquid container, 51 ... Blow-molded article, 53 ... Blow-molded article container section, 56 ... Side edge of blow molded product

Claims (10)

[Claims] 1. A container part formed of a polyolefin resin having a density of 0.915 to 0.930 g / cm ³ and an Orzene rigidity of 4000 kg / cm ² or less, having an opening at the upper end and a suspension opening at the lower end. A flexible liquid container for medical use, characterized in that it is formed by hollow molding, the container portion is flat, and the thickness of the wall of the container portion is thinner in the vicinity of the side peripheral edge portion and the lower peripheral edge portion than the central portion. Flexible liquid container for medical use used in closed system. 2. The liquid container according to claim 1, wherein the polyolefin-based resin is mainly composed of linear low-density polyethylene. 3. The liquid container according to claim 1 or 2, wherein the thickness of the container wall is in the range of 0.05 to 0.35 mm. 4. The container has a thickness of 0.1 to 0.15 mm near the side peripheral edge and the lower peripheral edge and 0.2 to 0.3 m near the central area.
The liquid container according to claim 3, wherein m is m. 5. The liquid container according to any one of claims 1 to 4, wherein the side peripheral edge portion and / or the shoulder peripheral edge portion of the container portion are heat-welded. . 6. A polyolefin resin having a density of 0.915 to 0.930 g / cm ³ and an Orsen rigidity of 4000 kg / cm ² or less is suspended on an opening at the upper end, followed by a flat-shaped container and the lower end thereof. Used in a closed system characterized by hollow molding using a mold having a mouth part such that the thickness of the wall of the container part is thinner in the vicinity of the side peripheral part and the lower peripheral part than in the central part. For producing a flexible medical liquid container. 7. The method for producing a liquid container according to claim 6, wherein the polyolefin-based resin has a linear low-density polyethylene as a main component. 8. The method for producing a liquid container according to claim 6 or 7, wherein the thickness of the container wall is in the range of 0.05 to 0.35 mm. 9. The container has a thickness of 0.1 to 0.15 mm near the side peripheral edge and the lower peripheral edge, and 0.2 to 0.3 m near the central area.
The method for manufacturing a liquid container according to claim 8, wherein the liquid container is m. 10. The container according to claim 6, wherein the side peripheral edge and / or the shoulder peripheral edge of the container is heat-welded by an external heating method. Liquid container manufacturing method.