JPH0117374B2 - - Google Patents

Description

〔Technical field〕

The present invention relates to a stopper for a medical container for airtightly closing the opening of the medical container. [Prior Art and Problems] Hard medical containers such as vacuum blood collection tubes and drug solution bottles are equipped with a stopper at the mouth in order to maintain the degree of internal vacuum or to isolate the contents from the external atmosphere. It is hermetically sealed. Conventionally, vulcanized butyl rubber has generally been used as a stopper for airtightly sealing this type of medical container. Vulcanized butyl rubber has excellent hermetic sealing properties due to its rubber elasticity. However, since vulcanized butyl rubber contains additives such as sulfur and vulcanization accelerators, these additives may be eluted into the blood when it comes into contact with the contents of medical containers, interfering with blood analysis. Something happened. This problem of elution of additives also occurs when the drug solution bottle is occluded. Therefore, the surface of the rubber stopper that comes into contact with the chemical solution is generally covered with plastic to prevent the additives contained in the rubber from transferring to the chemical solution during autoclave sterilization. In addition, when conventional vulcanized butyl rubber stoppers come into contact with blood, blood clots adhere to the stopper, which also interferes with accurate blood analysis and testing. Further, when collecting the solution in the container, a collection needle is pierced through the stopper. At this time, if a gap is created between the cap and the needle, the solution in the container may leak from there, so the stopper must have good sealing properties. Purpose of the Invention Therefore, the purpose of the present invention is to solve the above-mentioned conventional problems, to exhibit rubber-like elasticity, to contain no additives that may be leached, and to create a gap between the needle and the hour hand. It is an object of the present invention to provide a stopper for a medical container that does not require forming, has good resealability after needle removal, and exhibits thermoplasticity. According to this invention, the stopper is for airtightly closing the mouth of a medical container, and the stopper is made of butyl rubber.
30 to 90% by weight and thermoplastic elastomer 70
having a stopper body formed of an injection moldable polymeric material comprising a compound containing from 10% to 10% by weight;
A closure for a medical container is provided, characterized in that a sealing member is formed in a portion of the closure body into which the needle is to be pierced, so that no gap is formed between the closure and the needle. Generally, the stopper has a thin wall portion that can be penetrated by a needle,
A sealing member is formed within this thin walled portion. Such a sealing member is made of styrene elastomer or liquid rubber. Generally, butyl-based rubbers are selected from the group consisting of polyisobutylene, butyl rubber, partially crosslinked butyl rubber, and halogenated butyl rubber. Also,
Thermoplastic elastomers are usually selected from the group consisting of polyester elastomers, styrenic elastomers, polybutadiene and polyolefin elastomers. Furthermore, when the polymeric material contains up to 30% by weight of an olefinic polymer for improving moldability, molding becomes easier. Usually, the moldability-improving olefin polymer is selected from the group consisting of polypropylene, polyethylene, ethylene-ethyl acrylate copolymer, liquid paraffin, wax, and ethylene-vinyl acetate copolymer. Furthermore, it is preferred if the polymeric material contains filler in a proportion of up to 80% of the total weight of the filler and the weight of the formulation. This filler is generally selected from the group consisting of carbon black, clay, talc and white carbon. DETAILED DESCRIPTION OF THE INVENTION The present inventors have conducted various studies on materials suitable for medical container closures, that is, materials that exhibit rubber elasticity, do not contain additives that may be eluted, and have satisfactory gas barrier properties. It was discovered that a mixture of butyl rubber and a thermoplastic elastomer in a predetermined ratio can exhibit the desired performance of the plug body, and by forming a sealing member within the plug body, it is possible to prevent the needle from sticking when the needle is inserted. The present inventors have discovered that it is possible to provide a satisfactory plug without creating any gaps between them, and have completed the present invention. That is, the main body of the stopper of the present invention is basically formed of a blend consisting of 30 to 90% by weight of butyl rubber and 70 to 10% by weight of thermoplastic elastomer. Butyl-based rubber primarily provides gas barrier properties, and if its proportion is less than 30% by weight, it will not be possible to provide a closure with satisfactory gas barrier properties as a closure for medical containers. This butyl rubber alone has relatively large compression set and low rebound resilience and hardness, so it permanently deforms during use. Therefore, when used alone, it no longer functions as a stopper to airtightly close the medical container. Therefore, in this invention, a thermoplastic elastomer is blended to improve this.
If the proportion of butyl rubber exceeds 90% by weight, the effect of blending the thermoplastic elastomer cannot be obtained. Therefore, the proportion of thermoplastic elastomer is between 70 and
10% by weight, but if this amount exceeds 70% by weight, the effect of blending the butyl rubber will not be obtained, while if this amount is less than 10% by weight, the effect of improving the physical properties of the thermoplastic elastomer will not be obtained. It is only fully demonstrated. Examples of butyl rubber used in this invention include polyisobutylene, for example, viscosity average molecular weight
15,000 to 200,000, preferably 80,000 to 150,000 (available from Etsuo Kagaku under the trade names Vistanetx MML-100 and MML-140), butyl rubber, e.g. Mooney viscosity ML1+8 (100°C)
is 20 to 100, preferably 40 to 70, and the unsaturated content is 0.3 to
3.0 mol%, preferably from 0.7 to 1.5 mol% (under the trade names Etsuo Butyl 065 and 365 from Etsuo Kagaku Co., Ltd. and Polyservyl 100 from Polysar Co., Ltd.).
and 402), partially crosslinked butyl rubbers such as those with a cyclohexane soluble content of 50 wt. ) is 20 to 100, preferably 40 to 70, unsaturation is 0.1 to 3.0 mol%, preferably 0.7 to 2.0%, and halogen content is 0.5 to 3.0.
Weight% (Chlorobutyl 1066 from Etsuo Chemical)
Bromobutyl XZ (also available from Polycer under the trade name Bromobutyl Also, to give an example of thermoplastic elastomer,
Polyethylene elastomers such as those with a rebound modulus of 30% or more and a melting point of 220°C or less according to JISK6301 (Toray Polyester Elastomer Type S and Type H from Toray Industries, and Perprene P-150B and P-150M from Toyobo Co., Ltd.) ), polyolefin elastomers such as Mooney viscosity ML1+4 (at 100°C)
30-95, preferably 40-80 ethylene-propylene copolymer rubber and ethylene-propylene-
Non-conjugated diene copolymer and JISK6301 compression set (70℃ x 22 hours) is preferably 30 to 98%
Partially cross-linked ethylene-propylene rubber, propylene-grafted ethylene-propylene rubber and isobutylene-grafted polyethylene (from Sumitomo Chemical under the trade name Espren 301 and 505, from Mitsubishi Yuka under the trade name Thermolan 3600, and Milastomer from Mitsui Petrochemicals
5285), as well as styrene-based elastomers and polyamide-based elastomers. In the above blend of butyl rubber and thermoplastic elastomer, the proportion of butyl rubber is 50 to 70.
Preferably, it is % by weight. Although the above blend alone can form the plug body of the present invention, it is preferable to further blend a predetermined olefinic polymer in order to improve its moldability, especially its injection moldability. As this olefin polymer for improving moldability,
Melt index according to ASTMD1238 (g/
10 minutes) is 0.5 to 200 (for example, Idemitsu Polypro J-400M manufactured by Idemitsu Petrochemical Co., Ltd.),
Polyethylene (e.g. Yucalon LK manufactured by Mitsubishi Yuka)
-30), ethylene-ethyl acrylate copolymer (e.g., NVC copolymer manufactured by Nippon Unicar Co., Ltd.)
DPDJ-9169) Ethylene-vinyl acetate copolymer (for example, Ultracene UE633 manufactured by Toyo Soda Co., Ltd.), liquid paraffin, and wax. This moldability-improving olefinic polymer is blended in a proportion of up to 30%, preferably 10 to 20% of the total weight of the olefinic polymer and the weight of the blend. Polymer-based materials having the above compositions include carbon black (e.g., Asahi Carbon #55 manufactured by Asahi Carbon Co., Ltd.), clay (e.g., crown clay manufactured by Southeastern Clay Co., Ltd., hardtop clay manufactured by Shiraishi Calcium Co., Ltd.), talc, and white carbon. (For example, Fine Seal manufactured by Tokuyama Soda Co., Ltd.) may also be included. The filler is incorporated in a proportion of up to 80% of its weight plus the weight of the formulation, preferably 20-40%. This filler has the effect of increasing the strength of the plug and also improving its gas barrier properties. In order to form the stopper for a medical container of the present invention using the polymeric material described above, each component is heated preferably at 150 to 250°C using, for example, a Banbury mixer.
It is preferable to knead and pelletize at 170-190°C, and then injection mold at 120-250°C, preferably 200-220°C. The stopper for medical containers of the present invention does not create a gap between the needle and the stopper when a needle such as a blood collection needle is inserted into the main body formed of the polymeric material described above. A sealing member capable of holding the seal is embedded. To explain in more detail with reference to the attached FIG. 1, the main body of the plug of the present invention includes:
It has a cylindrical body 10 with a tapered tip surface 10a and a head 12 with a larger diameter than the cylindrical body 10. head 12
Recesses 14 and 16 are formed on the top surface of the body 10 and on the bottom surface of the body 10, respectively, and extend to face each other.
2a. In addition, the head 12 of the body 10
An annular groove 18 is formed in the vicinity to prevent the stopper from falling out of the container due to the pressure inside the container when the stopper is pushed into the container.
A sealing member 20 is embedded in the center of the bottom surface of the recess 14 (where the needle is inserted). This sealing member 20 is made of styrene-based elastomer, such as those available from Ciel Chemical Co. under the trade names TR2104 and G7705 (hardness 55 or less, according to JISA).
It is obtained by insert molding at the same time as the injection molding of the plug body. Alternatively, it can also be obtained by molding a plug body having a recess at the center of the bottom of the recess 14, and then pouring liquid rubber such as silicone sealant. The most preferred resin compound for molding the plug body (excluding the sealing member) in such a plug body is Vistanex MML.
-100 (35 parts by weight), PBXL-50 partially crosslinked butyl rubber (25 parts by weight), 1,2-polybutadiene (PB830 manufactured by Nippon Gosei Kagaku Co., Ltd.) (25 parts by weight), styrene elastomer (G1652 manufactured by Ciel Chemical Co., Ltd.) ( 10 parts by weight)
and liquid paraffin (10 parts by weight). The plug shown in FIG. 2 has the same structure as the plug shown in FIG. 1, except that the annular groove 22 is provided in the lower surface of the part where the head 12 protrudes from the body 10. are indicated with the same reference numerals. Annular groove 2
2 can prevent the stopper from falling into the container. The one shown in FIG. 3 is a so-called vial stopper, except that it is flatter overall than the stopper shown in FIG. 1, and the head 12 has a reversely tapered outer peripheral surface 12b. The configuration is similar to that shown in FIG. Note that after the plug is formed, the strength characteristics can be improved by irradiating it with gamma rays. Test examples showing the physical properties of the polymer-based material of the plug of the present invention will be shown below. Test Example 1 The ingredients shown in Table 1 below were kneaded using a Banbury mixer at 190°C for 10 minutes to obtain a molding material. Table 2 shows the test results of these molding materials in accordance with the 9th revised Japanese Pharmacopoeia test method for rubber stoppers for infusions.
and the physical property test results are shown in Table 3.

[Table] For sample 4, ⁶⁰ Coγ rays were applied after molding.
It was irradiated with 3.5 Mrad.

【table】

[Table] Note that the stopper of the present invention is suitable for use in a so-called vacuum blood collection tube as shown in FIG. In FIG. 4, a blood collection tube 52 whose interior has been depressurized to the extent that a predetermined amount of blood can be aspirated is hermetically closed by a stopper 51 as shown in FIG. 1, for example, to maintain the degree of internal decompression. ing. Specific Effects of the Invention The stopper for medical containers of the present invention as described above exhibits rubber-like elasticity, so it exhibits its closing function well over a long period of time, and also has good resealability after being pierced with a needle (pierced hole There is no problem with the sealing performance. In addition, it does not contain additives that may be leached, making it superior to conventional products in terms of safety and accurate analysis of contents. Furthermore, the stopper of the present invention has no problem in gas barrier properties, does not alter the contents, and can maintain the internal reduced pressure for a relatively long period of time, especially in the case of vacuum blood collection tubes. In addition, since the plug of this invention is made of a material that can be injection molded, its physical properties are the same before and after molding, compared to conventional materials that exhibit plasticity before molding and elasticity after molding. A plug body with desired physical properties can be easily obtained by selecting a desired material. Furthermore, since this plug is not vulcanized,
It is possible to reuse the runner and sprue, and it can be recycled without incineration, and it can be injection molded, which significantly shortens molding time compared to those that involve a conventional vulcanization process, and has good mold release properties. Therefore, it is suitable for mass production. In addition, the plug body of this invention is heat resistant and can be easily transported and
It can withstand temperatures well during storage and can also withstand gamma ray sterilization. Furthermore, since it is not vulcanized, no sulfur dioxide gas is generated even if it is incinerated, and since it does not contain metals such as zinc, it does not elute. Further, since the plug of the present invention has a sealing member, no gap is created between the needle and the plug when the needle is inserted, so that blood etc. will not spill and stain the plug.

[Brief explanation of drawings]

1 to 3 are partially sectional side views of a stopper for a medical container according to the present invention, and FIG. 4 is a sectional view showing a vacuum blood collection tube using the stopper of the present invention. DESCRIPTION OF SYMBOLS 10... Body part, 12... Head part, 12a... Thin wall part, 14, 16... Recessed part, 20... Seal member.

Claims (1)

[Scope of Claims] 1. A stopper for airtightly closing the mouth of a medical container, comprising 30 to 90% by weight of butyl rubber.
and a stopper body made of an injection-moldable polymeric material made of a compound containing 70 to 10% by weight of a thermoplastic elastomer; A stopper for a medical container characterized by forming a sealing member that does not form a gap therebetween. 2. The plug body according to claim 1, wherein the plug body has a thin wall portion through which a needle can penetrate, and the sealing member is formed within the thin wall portion. 3. The plug according to claim 1 or 2, wherein the sealing member is made of a styrene elastomer. 4. The plug according to claim 1 or 2, wherein the sealing member is made of liquid rubber. 5. The plug according to any one of claims 1 to 4, wherein the butyl rubber is selected from the group consisting of polyisobutylene, butyl rubber, partially crosslinked butyl rubber, and halogenated butyl rubber. 6. Claim 1, wherein the thermoplastic elastomer is selected from the group consisting of polyester elastomer, styrene elastomer, polybutadiene, and polyolefin elastomer.
The plug according to any one of Items 1 to 5. 7. The plug according to any one of claims 1 to 6, wherein the polymeric material contains up to 30% of an olefinic polymer for improving moldability. 8. A patent claim in which the olefinic polymer for improving moldability is selected from the group consisting of polypropylene, polyethylene, ethylene-ethyl acrylate copolymer, liquid paraffin, wax, and ethylene-vinyl acetate copolymer. The plug according to range 7. 9. A plug according to any one of claims 1 to 8, wherein the polymeric material contains a filler in a proportion of up to 80% of the total weight of the filler and the weight of the compound. 10. The plug according to claim 9, wherein the filler is selected from the group consisting of carbon black, clay, talc, and white carbon.