JP3686890B2 - Container stopper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stopper for needle stick used in a mouth of a container such as a medical or medicinal bottle or bag containing an infusion such as an amino acid or an electrolyte or a solution of a freeze-dried preparation.
[0002]
[Prior art]
This type of stopcock is mainly made of rubber such as butyl rubber, isoprene rubber, butadiene rubber, natural rubber, etc., but this requires a vulcanization and cleaning process, and is expensive to process. Since the stopper main body and the outer cap surrounding the stopper main body are made of different materials, there is also a difficulty in separating and disposal.
[0003]
In recent years, in order to eliminate such drawbacks of rubber stoppers, many medical and medical stoppers made of thermoplastic elastomer have been developed. For example, there is a stopper that prevents liquid leakage by molding a plug body with a thermoplastic elastomer and then insert molding an outer cap to increase the internal pressure of the thermoplastic elastomer plug body. Also, there is a method of manufacturing a needle stick stopper by molding an outer cap of a stopper and injection molding a needle stick portion of a thermoplastic synthetic resin elastic body with an injection pressure of 500 kg / cm 2 or more (Japanese Patent Laid-Open No. 2000). -140068). There is also a stopcock in which a plug body made of a thermoplastic elastomer and an outer cap are separately molded and assembled.
[0004]
[Problems to be solved by the invention]
However, any of the above-mentioned thermoplastic elastomer stoppers must be sterilized at a high temperature and high pressure before being used for injection or infusion needles. May leak after needle sticking, and may lose the needle holding force during needle sticking.
[0005]
In addition, when a chemical solution is administered to the human body in a medicinal container using this kind of stopper, the chemical solution is connected to the human body through a connecting tube from a resin needle stuck in the medicinal container such as an infusion set or catheter, but between the human body and the chemical solution container. From the distance, importance is attached to the needle holding force when a plastic needle is inserted into a stopcock by its own weight such as a connecting tube and a connector. Conventional stopper plugs made of thermoplastic elastomer increase the hardness of the plug body to increase the needle holding force, or increase the holding force of the needle by making the plug body thicker than necessary. If the wall thickness of the plug body is increased, the manufacturing time and the material cost of the plug body are increased, and the cost is increased.
[0006]
Therefore, the object of the present invention is to prevent needle leakage even when a needle is inserted or removed after sterilization at high temperature and high pressure, and even if the resistance of needle insertion is reduced without increasing the wall thickness of the stopper body. An object of the present invention is to provide a stopper for a container that can sufficiently secure a holding force.
[0007]
[Means for Solving the Problems]
Stopcock of the container of the present invention, needle sticks can plug body made has thermoplastic elastomer inner diameter larger than the outer diameter of the outer cap ring shape are press-fitted to the inside of the outer cap, before Kigai cap stopper ring is fitted on the lower surface side of the plug body of the inner, the open top surface of the stopper ring, the two 50~350μm thick film are insert-molded or welded, one film is the plug of which It is characterized in that it is welded to the lower surface of the main body and an air layer is formed between the second film .
[0008]
[0009]
When a plug body made of a thermoplastic elastomer having an outer diameter larger than the inner diameter of the outer cap is press-fitted into the outer cap as in the above configuration, the plug body has an internal stress that is constantly compressed by the outer cap. It is in. Therefore, even after sterilization at high temperature and high pressure, when the needle is inserted into the stopper body, even if the pierced part is cut and opened, it is closed by the elastic restoring force due to the compressed internal stress. Does not leak, and the needle holding force increases. Further, even after the needle is removed from the stopper body, this portion is closed by the elastic restoring force due to the compressed internal stress, so that the liquid inside does not leak.
[0010]
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a stopper plug according to one embodiment, FIG. 2 is a sectional view showing an outer cap and a stopper body of the stopper stopper of FIG. 1 in a separated state, and FIG. 3 is a sectional view of a stopper body according to another embodiment. .
[0012]
1 and 2, the stopper of the container of the present invention is made of a thermoplastic elastomer having an outer diameter b larger than an inner diameter a of the outer cap 1 in a free state on an outer cap 1 formed in an annular shape. It is formed by press-fitting a plug body 2 that can be needle-punctured.
[0013]
As the thermoplastic elastomer that is the material of the plug body 2, at least one of a styrene elastomer, an olefin elastomer, and a polyester elastomer is selected and used alone, in combination, or mixed. The plug body 2 made of a thermoplastic elastomer is molded from a thermoplastic elastomer having an elastomer hardness (JISK6301) of 15 to 70 degrees, more preferably 25 to 45 degrees.
[0014]
In FIG. 2, the ratio of the inner diameter a of the outer cap 1 to the outer diameter b of the plug body 2 is preferably a: b = 1: 1.05-1.25. When the outer diameter b of the plug body 2 exceeds 1.25 times the inner diameter a of the outer cap 1, it is difficult to press-fit the plug body 2 into the outer cap 1. Specifically, for example, the inner diameter a of the outer cap 1 is 23.18 mm, and the outer diameter b of the plug body 2 is 27.0 mm.
[0015]
In FIG. 2, the plug body 2 is formed in a biconcave lens shape having a cross section that is thicker at the outer peripheral portion of the needle stick region than the thickness t2 of the central portion and gradually becomes thinner from the outer peripheral portion toward the central portion. ing. An appropriate number of needle puncture designating portions 8 for setting a needle puncture position are recessed in the central portion of the upper surface of the needle puncture region of the stopper body 2 and in the vicinity of the central portion. A concave portion 9 is formed on the lower surface of the stopper body 2 so as to face the needle puncture designation portion 8.
The ratio between the outer peripheral wall thickness t1 and the central wall thickness t2 of the needle stick region of the stopper main body 2 in the free state is preferably 1: 0.3 to 0.95. Specifically, for example, the outer peripheral wall thickness t1 of the needle stick region of the stopper main body 2 is set to 5.5 to 6.5 mm, and the central wall thickness t2 is set to 2.4 to 5.2 mm. In this case, the thickness t3 of the needle stick designation portion 8 is set to 0.25 to 0.45 mm.
[0016]
The top opening of the outer cap 1 is closed by a top plate (pull top) 3 with a pull tab 5 so that it can be pulled open. The top plate 3 is integrally formed with the outer cap 1 through a thin tear-off part (score) 4, and a ring-shaped pull tab 5 is integrally formed on the top surface of the top plate 3. By pulling the pull tab 5 with a finger, the tearing portion 4 of the top plate 3 is torn off and the top surface of the outer cap 1 can be pulled open. In this case, the tearing force applied to the pull tab 5 is 4.5 kg or less, more preferably 3.5 kg (20 mm / 60 seconds movement), and the top plate 3 is set to be easily torn.
[0017]
A stopper ring 7 having a film (membrane) 6 having a thickness of 50 to 350 μm as shown in FIG. 1 is fitted on the lower surface side of the plug body 2 in the outer cap 1. In this case, as shown in FIG. The stopper ring 7 having a film 6 having a thickness of 50 to 350 μm is integrally formed on the lower surface of the plug body 2 by insert molding, and then fitted to the outer cap 1 together with the plug body 2 from the open bottom thereof. At that time, if vertical grooves 10 are provided at several locations on the inner surface of the outer cap 1 so that the inner air can be removed from the grooves 10 when the plug body 2 is press-fitted, the plug body 2 is press-fitted. Easy to do. When the stopper ring 7 is fitted, an annular ridge 11 is provided on the outer periphery of the stopper ring 7, and the ridge 11 is fitted in a groove 12 provided on the lower inner circumference of the outer cap 1.
[0018]
The stopper having the above structure is used by welding the lower end of the outer cap 1 to the mouth of a container such as a medical or medicinal bottle or bag. In this case, the same kind of resin material as the outer cap 1 of the stopper, the stopper body 2 and the stopper ring 7 is used as the material of the container so that there is no need for separate disposal and it is advantageous for recycling.
[0019]
As the film 6 to be attached to the stopper ring 7, it is preferable to select a thin film having a thickness of 50 to 350 μm for the following reason.
The purpose of attaching the film 6 to the stopper ring 7 is to prevent the missing piece from falling off due to a coring phenomenon in which a part of the plug body 2 is lost during needle sticking or needle removal, and to prevent leakage of chemicals due to an increase in internal pressure during high temperature sterilization. For. The film 6 is integrally formed on the upper end surface of the stopper ring 7 by insert molding. At this time, the material selected as the molding material for the film 6 is polypropylene (PP) having a thickness of 350 μm, or polyethylene (PE) having a thickness of 450 μm. The thickness is the minimum wall thickness that allows resin flow during film formation. However, in the film 6 having a thickness of more than 350 μm, when the stopper body 7 is integrally molded with the stopper body 7 in which the film 6 is integrally formed and assembled as a stopper, the needle stick strength becomes 6.0 kg or more. This has the disadvantage that a strong force is required when a plastic needle is stabbed at a medical site, making it difficult for nurses and other women to use.
[0020]
Further, when the plug body 2 is insert-molded in the stopper ring 7 with the film 6, the plug body made of thermoplastic elastomer after sterilization due to the difference between the shrinkage degree of the elastomer of the stopper body 2 and the shrinkage degree of the molding resin of the stopper ring 7 2 is pulled by the molding resin of the stopper ring 7 to cause liquid leakage. For example, the shrinkage rate of the styrene elastomer that is the molding material of the plug body 2 is 25 to 35/1000%, and the shrinkage rate of the polypropylene resin that is the molding resin of the stopper ring is 8 to 16/1000%. When the stopper main body 2 is torn by needle puncture, the torn portion is pulled outward by a film 6 thicker than 350 μm thick attached to the upper end surface of the stopper ring 7 and causes liquid leakage from the portion.
[0021]
However, when the film 6 having a thickness of 50 to 350 μm is used as the film 6 to be insert-molded or welded to the stopper ring 7, the needle stick resistance is suppressed to 4.5 kg or less, and the entire thin film 6 is made of the thermoplastic elastomer plug body 2. Since it is integrated along the lower surface, it is advantageous for preventing liquid leakage.
[0022]
The thermoplastic elastomer of the material of the plug body 2 contains additives such as a softening agent. However, when the plug body 2 is press-fitted to the outer cap 1, the additive oozes out or has elapsed after the press-fitting. The range of selection of the thermoplastic elastomer material is limited. Therefore, as shown in FIG. 3, two first and second films 6a and 6b are used as the film 6 having a thickness of 50 to 350 μm to be attached to the stopper ring 7 in order to give a degree of freedom in selecting the material of the thermoplastic elastomer. Is used. The second film 6b is integrally welded to the lower surface of the plug body 2 to form an air layer 13 between the second film 6b and the first film 6a. When the air layer 13 is formed between the first and second films 6a and 6b as described above, the barrier function that the air layer 13 effectively blocks the additive that oozes or elutes from the plug body 2 is obtained. Demonstrated and can be prevented from mixing into chemicals. Therefore, the degree of freedom in selecting the material of the thermoplastic elastomer can be obtained. The film 6 may be three or more.
[0023]
The material selection of the thermoplastic elastomer plug body 2 and the outer cap 1 also greatly affects the liquid leakage during the high temperature sterilization treatment and the needle stick holding force after sterilization.
A stopper formed by press-fitting a stopper body 2 having an outer diameter larger than the inner diameter of the outer cap 1 is welded to the mouth of a container such as a bottle or a bag, and this is subjected to high-temperature and high-pressure sterilization treatment (121 ° C for 30 minutes). Then, the outer cap 1 expands against the expansion pressure of the plug body 2, and then the plug body 2 contracts to eliminate the dimensional difference between the outer diameter of the plug body and the inner diameter of the outer cap. . Therefore, it is necessary to mold the outer cap 1 with a resin material having a bending elastic modulus that does not lose the expansion pressure of the plug body 2 during high temperature sterilization.
[0024]
Therefore, the present invention makes it possible to prevent liquid leakage and secure the needle holding force by defining the correlation between the elastomer hardness (JISK6301) of the thermoplastic elastomer plug body 2 and the bending elastic modulus (K7203) of the outer cap 1. . That is, the relationship between the elastomer hardness of the plug body 2 (use of Lavalon (registered trademark) manufactured by Mitsubishi Chemical Corporation as a styrene elastomer) and the flexural modulus of the outer cap 2 made of polypropylene is shown in the table of FIG. Thus, the flexural modulus (K7203) is 300 Mpa or more, more preferably 350 to 700 Mpa. This will be clearly understood from the situation of liquid leakage during high temperature sterilization as shown in the table of FIG.
[0025]
When the outer cap 1 is a cap with a pull tab 5, the tear strength of the top plate 3 becomes a problem. Usually, the tearing strength of the pull tab 5 is preferably 3.5 kg (20 mm / l movement) or less so that women and girls can easily pull it apart. However, the thickness of the thin tearing portion 4 of the molded product of the outer cap 1 with the pull tab 5 requires a minimum thickness of 0.35 mm for molding. This is because when the thickness of the molded product is 0.35 mm or less, the resin does not rotate around the entire molded product during molding, resulting in molding failure. If the outer cap 1 with a pull tab made of resin satisfying the above-mentioned bending elastic modulus (K7203) of 350 Mpa when the thickness of the tearing portion 4 is 0.35 mm or more, the tearing strength is 6 kg or more, and the tearing portion 4 It becomes difficult to tear off.
[0026]
Therefore, using a resin having a flexural modulus (K7203) of 350 MPa or more and reducing the tear strength of the top plate 3 with the pull tab 5, the thickness of the tear portion 4 should be 0.1 to 0.25 mm. preferable. In order to obtain the outer cap 1 with the pull tab 5 in which the thickness of the tear-off portion 4 is 0.1 to 0.25 mm, as shown in FIG. Compress to 1 to 0.25 mm to form the outer cap 1 with the pull tab 5. At that time, the entire top surface 14a of the protruding core 14 is formed in a convex arcuate surface, so that the resin on the top surface side in the outer cap molding cavity is protruded when the protruding core 14 is protruded. Therefore, the outer cap 1 can be easily molded.
[0027]
Moreover, the inner surface of the top plate 3 with the pull tab 5 formed in this way is formed in a concave arc surface 3a, and between the concave arc surface 3a and the concave arc surface 2a of the needle stick region of the stopper body 2, A space 15 is formed as shown in FIG. This space 15 prevents the needle stick region of the thermoplastic elastomer plug body 2 and the inner surface 3a of the top plate 3 with the pull tab 5 from being melted and integrated due to the sterilization temperature even during high temperature and high pressure sterilization. This is useful for easily tearing the attached top plate 3 with a small pulling operation force.
[0028]
When molding the plug body 2 made of thermoplastic elastomer, air bubbles are often involved in the plug body 2 due to the fluidity of the thick elastomer. If a needle is pierced into the bubble, liquid leakage may occur when the needle is removed. Therefore, in the present invention, as shown in FIG. 6, when the stopper body 7 with the thin film 6 previously attached is held on the core 16 and the plug body 2 is simultaneously formed in the cavity 20, as shown in FIG. 7 is provided with a gas vent hole 18 of 0.05 mm or less between the outer periphery of the die 7 and the die 17 at a predetermined interval in the circumferential direction, so that only air gas is released. Is obtained.
[0029]
According to the stopper of the present invention in which the plug body 2 made of a thermoplastic elastomer having an outer diameter larger than the inner diameter of the cap is press-fitted into the outer cap 7 with a pull tab obtained as described above, the resin needle after high-temperature sterilization is A sufficient needle holding force was obtained even when stabbed, and a good result was obtained that no liquid leakage occurred even when the needle was removed after 1 hour or more had elapsed.
[0030]
In the present invention, the outer cap 1 is not limited to the one having the pull tab as described above, and has an easy peel film in which the top surface opening of the outer cap 1 is closed by an external airtight film 19 as shown in FIG. The same applies to the outer cap. In this case, the outer airtight film 19 is welded to the outer cap 1 so as to close the opening on the top surface.
[0031]
【Example】
Example 1
The outer diameter of the outer cap 1 made of polypropylene is 23.18 mm, and the maximum outer diameter in the free state of the plug body 2 made of styrene-based elastomer (manufactured by Mitsubishi Chemical Corporation, Lavalon (registered trademark) T331C 28 hardness (JISK6301)) is 27. 0.02 mm, the outer peripheral wall thickness t1 of the needle stick region of the stopper body 2 is 5.8 mm, the central wall thickness t2 is 3.8 mm, and the cross-concave biconcave lens gradually becomes thinner from the outer peripheral portion toward the central portion. The stopper body 7 was press-fitted and assembled into the outer cap 1 and assembled with the stopper ring 7.
[0032]
Comparative Example 1
The inner diameter of the outer cap and the outer diameter of the plug body in the free state are both the same as in the case of Example 1 except that the inner diameter is 23.18 mm.
[0033]
Comparative Example 2
The same as in the case of Example 1, except that the plug body has a uniform overall thickness of 5.8 mm and a flat cross-sectional shape in which the upper and lower surfaces are parallel.
[0034]
(Test method)
A bottle or bag container capable of storing a full capacity of 600 ml is filled with 500 ml of electrolyzed water (chemical solution), and the stoppers of Example 1, Comparative Example 1 and Comparative Example 2 are thermally welded to the mouths of the containers, respectively. Measure the total weight. The containers in which the stoppers of Example 1, Comparative Example 1 and Comparative Example 2 were welded were sterilized with steam heat of 121 ° C. for 30 minutes, and a Φ4.5 resin needle was stabbed into the needle stab designation portion 8. After the elapse of time, the needle was removed, and after pressurizing at 4.5 kg for 3 minutes, the total weight of the container was measured again, and the amount of liquid leakage was examined by comparing the weight before needle penetration and after needle penetration. .
[0035]
(Test results)
The results of the comparative test are as shown in the chart of FIG. Occurrence of liquid leakage from the stoppers of containers sterilized at high temperature using the stopper of Example 1 was 0.003 g (one drop was 0.035 g) on average, and no one drop was leaked. That is, even if sterilized with steam heat at 121 ° C. for 30 minutes, it was found that there was no problem in the leak test of the stopper plug of Example 1.
In contrast, the stoppers of Comparative Example 1 averaged 31.61 g, the maximum was 80.31 g, the minimum was 3.0 g, and the leakage was severe, and the stoppers of Comparative Example 2 were 9.27 g on average and 21 at maximum. .26 g and a minimum of 1.03 g, neither of which could prevent liquid leakage.
[0036]
【The invention's effect】
According to the stopper of the container of the present invention, it is possible to well prevent liquid leakage at the time of needle sticking and needle withdrawal even after high temperature and high pressure sterilization, and even if the thickness of the stopper body is not so thick, the needle stick resistance can be reduced. There is an advantage that a sufficient needle-stick holding force can be secured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a stopcock according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an outer cap and a plug body of the stopper plug of FIG. 1 in a separated state.
FIG. 3 is a cross-sectional view of a plug body of another embodiment.
FIG. 4 is a cross-sectional view showing a molding aspect of an outer cap with a pull tab.
FIG. 5 is a half cutaway cross-sectional view of a mold showing an embodiment in which a stopper ring is held in a molding die of a stopper main body.
6 is a cross-sectional view taken along line AA in FIG.
FIG. 7 is a cross-sectional view of a stopper plug according to another embodiment.
FIG. 8 is a chart showing the correlation between the elastomer hardness of the thermoplastic elastomer plug body and the bending elastic modulus of the outer cap.
FIG. 9 is a chart showing a comparison result of a liquid leakage test between Example 1 and Comparative Examples 1 and 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer cap 2 Plug body 3 Top plate 4 Tearing part 5 Pull tab 6 Film 6a 1st film 6b 2nd film 7 Stopper ring 8 Needle stick designation | designated part 13 Air layer 15 Space 19 Film

Claims (1)

A needle pierceable stopper body made of a thermoplastic elastomer having an outer diameter larger than the inner diameter of the ring-shaped outer cap is press-fitted into the outer cap, and a stopper ring is provided on the lower surface side of the stopper body inside the outer cap. Are inserted and welded to the upper end surface of the opening of the stopper ring, and one of the films is welded to the lower surface of the stopper body, and 2 A stopper for a container, wherein an air layer is formed between the first film and the film .

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