Medical rubber stoppers

Abstract

To provide a medical rubber plug body in which an amount of leakage of residual liquid in a medical container is small even when an injection needle is pulled out.SOLUTION: A medical rubber plug body according to the present disclosure comprises a cap part, and a leg part extending downward from the cap part. The medical rubber plug body comprises a first part on the side of the leg part, and a second part located on the side of a top surface of the first part, in a puncture part. The first part and the second part are not bonded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a medical rubber stopper, and more particularly to a medical rubber stopper for sealing or plugging an intravenous bag or a vial. [Background technology]

[0002] Medical rubber products used in pharmaceutical containers require high quality and physical properties. For example, the quality characteristics required for medical rubber stoppers, which seal or stop the openings of vials containing antibiotics and other preparations, should conform to the rubber closure test for infusions in the 17th revision of the Japanese Pharmacopoeia, due to their intended use. Furthermore, medical rubber stoppers used to seal the openings of vials must meet many requirements, including gas permeability resistance, non-elution, high cleanliness, chemical resistance, needle resistance, and self-sealing properties.

[0003] Patent Document 1 discloses a medical rubber stopper that is applied to the opening of a medical container and has a puncture part that can be punctured with the needle of a syringe, and that has a nylon film layer with a thickness of 20 to 200 μm provided on the top surface of the medical rubber stopper.

[0004] Patent Document 2 discloses a method for manufacturing a stopper using a two-stage molding method, in which a leg is molded and then a cap is molded while adhering to the leg, and the method is characterized in that a film made of a polymer alloy consisting of at least one selected from the group consisting of olefin-based plastics and synthetic rubbers and at least one selected from thermoplastic elastomers is sandwiched between the leg and cap.

[0005] Patent Document 3 discloses a medical rubber stopper that includes a disk-shaped flange and legs connected to the underside of the flange, the underside region of the flange and the legs being made of nitrile rubber, the top side region of the flange being made of butyl rubber, and the legs being laminated with a coating layer made of a fluorine-based resin film.

[0006] Patent Document 4 discloses a rubber molded product for cryogenic storage containers, which is formed by laminating a silicone rubber containing an elastomer and a silicone rubber or butyl-based rubber containing an elastomer via a polyethylene film having a molecular weight of 1,000,000 to 7,000,000.

[0007] Patent Document 5 discloses a rubber stopper for a reduced-pressure blood collection tube, which requires maintaining a reduced pressure inside, and which is characterized in that the rubber stopper is made of a gas barrier material membrane and a thermoplastic elastomer rubber stopper body, and is designed to substantially prevent air from diffusing into the reduced-pressure blood collection tube through the rubber stopper. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-340425 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-297432 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-5947 [Patent Document 4] International Publication No. WO2009 / 151129 [Patent Document 5] Japanese Patent Application Publication No. 57-59536 Summary of the Invention [Problem to be solved by the invention]

[0009] When inserting a syringe needle into a medical rubber stopper of a medical container such as a vial, the drug is drawn from the medical container into a syringe, and then the needle is removed. When the needle is removed, there is a problem that the remaining liquid in the medical container leaks out from the gap where the needle was inserted and splashes around.

[0010] The present disclosure has been made in consideration of the above circumstances, and aims to provide a medical rubber stopper that reduces leakage of residual liquid from a medical container even when the injection needle is pulled out. [Means for solving the problem]

[0011] The medical rubber stopper of the present disclosure is a medical stopper having a cap portion and a leg portion extending downward from the cap portion, and is characterized in that the medical rubber stopper has, at the puncture portion, a first portion on the leg portion side and a second portion located on the top surface side of the first portion, and the first portion and the second portion are non-adhered. [Effects of the Invention]

[0012] By using the medical plug of the present disclosure, residual liquid in the medical container will not leak even when the injection needle is pulled out. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an explanatory view of one embodiment of a medical rubber stopper of the present disclosure. FIG. [Figure 2] 1 is an explanatory view of one embodiment of a medical rubber stopper of the present disclosure. FIG. [Figure 3] 1 is an explanatory view of one embodiment of a medical rubber stopper of the present disclosure. FIG. [Figure 4] 1 is an explanatory view of one embodiment of a medical rubber stopper of the present disclosure. FIG. [Figure 5] 1A to 1C are explanatory diagrams illustrating a manufacturing process for the medical rubber stopper of the present disclosure. [Figure 6] 1A to 1C are explanatory diagrams illustrating a manufacturing process for the medical rubber stopper of the present disclosure. [Figure 7] FIG. 2 is a cross-sectional view for schematically explaining the function of the medical rubber stopper of the present disclosure. [Figure 8] FIG. 2 is a cross-sectional view for schematically explaining the function of the medical rubber stopper of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] (1) Medical rubber stoppers The medical rubber stopper of the present disclosure is a medical rubber stopper having a cap portion and a leg portion extending downward from the cap portion, and is characterized in that the medical rubber stopper has, at the puncture portion, a first portion on the leg portion side and a second portion located on the top surface side of the first portion, and the first portion and the second portion are non-adhered.

[0015] The medical rubber stopper of the present disclosure has an up-down direction. The top surface side is the upper side, and the leg side is the lower side. The medical rubber stopper of the present disclosure has a cap portion and a leg portion extending downward from the cap portion.

[0016] The cap portion is preferably disk-shaped, and the diameter of the disk-shaped cap portion can be appropriately designed depending on the size of the medical container to be stoppered.

[0017] The cap portion has a puncture portion that can be punctured with the needle of a syringe, and a flange portion that contacts the upper edge surface of the opening of the medical container when the medical container is capped.

[0018] The puncture portion is preferably located at the center of the cap portion in a plan view of the medical rubber stopper. The puncture portion of the cap portion is preferably circular in a plan view. The puncture portion is preferably formed in a concave shape relative to the top surface of the cap portion.

[0019] It is also preferable to provide a protrusion on the top surface of the cap portion to prevent the rubber stoppers from sticking together when cleaning, sterilizing, and drying the medical rubber stopper body, and to prevent the rubber stopper from sticking together with a cap that is tightened onto the rubber stopper body.

[0020] The protrusions are preferably protrusions that partially protrude from the top surface of the flange. The planar shape of the protrusions is not particularly limited, and may be circular, elliptical, semicircular, fan-shaped, egg-shaped, or other roughly circular shapes, as well as a roughly rectangular track-shaped shape with semicircular edges on opposite sides of a rectangle. Considering transport in a parts feeder, close contact of the rubber stoppers with the wall surface during cleaning, and cases where multiple rubber stoppers are packed together in a bag, it is preferable that these protrusions have a small contact surface. When the rubber stopper is inverted, these protrusions preferably support the main body at points rather than across the entire periphery of the top surface. The number of protrusions is not particularly limited, but 4 to 12 is preferred. The arrangement is also not particularly limited, but it is preferable that they are arranged radially or along the circumference of the flange.

[0021] The medical rubber stopper of the present disclosure has a leg portion extending downward from the underside of the cap portion, and when a medical container is stoppered with the medical rubber stopper of the present disclosure, the leg portion fits into the opening of the medical container.

[0022] The leg portion is not particularly limited in shape as long as it can be fitted into the opening of the medical container. Examples of the leg portion include a leg portion having a continuous cylindrical shape and a multiple leg portion having two or more branches.

[0023] In a leg having a continuous cylindrical shape or multiple legs that are bifurcated or more, it is preferable that the opposing inner surfaces of the legs are tapered so that the distance between the inner surfaces of the legs gradually decreases from the bottom to the top (towards the top surface).

[0024] In one embodiment of the present disclosure, the medical rubber stopper has, at the puncture portion, a first portion on the leg side and a second portion located on the top surface side of the first portion, and the first portion and the second portion are not bonded together.

[0025] The first part is a part of the puncturing part that is located on the leg part side and includes a part of the puncturing part that is located below the cap part. The first part may include a leg part in addition to the part that is located below the cap part of the puncturing part.

[0026] The second part is a part located on the top surface of the first part and includes a part above the cap part at the puncture part. The second part may include a flange part of the cap part in addition to the part located above the cap part at the puncture part. The first and second parts of the medical rubber stopper of the present disclosure are preferably adjacent to each other in the vertical direction at the puncture part. In other words, the vertical boundary between the first and second parts is preferably present within the cap part at the puncture part.

[0027] The first and second parts may be unbonded at the puncture site but bonded in areas other than the puncture site. In this embodiment, when the injection needle is withdrawn, the second part elastically deforms, creating a space between the first and second parts. This space serves as a buffer space to accommodate medicinal liquid leaking from the medical container, thereby enabling the medical stopper of the present disclosure to reduce liquid leakage.

[0028] Methods for making the first and second parts non-bonded include, for example, a method in which the legs and cap are vulcanization molded separately, and when bonding the legs and cap with adhesive, the adhesive is not applied to the puncture areas of the legs and cap, but is applied to the areas outside the puncture areas; a method in which the legs are vulcanization molded, a release agent is applied only to the puncture areas on the top surface of the molded legs, an unvulcanized rubber sheet is laminated thereon, and the cap is vulcanization molded.

[0029] In another preferred embodiment of the present disclosure, the medical rubber stopper has a film between the first part and the second part, and at the puncture part, it is preferable that the film is adhered to one of the first part and the second part and not adhered to the other of the first part and the second part.

[0030] In this embodiment, when the injection needle is withdrawn, the second part elastically deforms, creating a space between the film and either the first or second part that is not adhered to the film. This space serves as a buffer space to accommodate medicinal liquid leaking from the medical container, thereby enabling the medical plug of the present disclosure to reduce liquid leakage.

[0031] It is also a preferred embodiment to use a film having a higher rigidity than the rubber material constituting the first or second part. The difference in rigidity between the film and the first or second part makes it easier for spaces to form.

[0032] It is preferable that the medical plug has at least two films between the first part and the second part, and that at the puncture part, the first film in contact with the first part is adhered to the first part, the second film in contact with the second part is adhered to the second part, and the first film and the second film are not adhered to each other.

[0033] In this embodiment, when the injection needle is withdrawn, the second part elastically deforms, creating a space between the first film and the second film that are not adhered to the film. This space serves as a buffer space to accommodate the medicinal solution leaking from the medical container, thereby enabling the medical plug of the present disclosure to reduce liquid leakage.

[0034] The number of films disposed between the first part and the second part is not particularly limited as long as it is two or more, but is preferably two.

[0035] In the puncture part, the shape of the film placed between the first and second parts in a plan view is preferably the same as or similar to the shape of the puncture part, and more preferably circular. The area of ​​the film is preferably 60% or more, more preferably 70% or more, and more preferably 80% or more, and preferably 120% or less, more preferably 110% or less, and even more preferably 100% or less of the area of ​​the puncture part.

[0036] The film and the puncturing part are preferably arranged so as to overlap in a plan view. When the film and the puncturing part have the same shape, the film and the puncturing part are preferably arranged so as to overlap. When the film and the puncturing part have similar shapes, the film and the puncturing part are preferably arranged so that the centers of similarity are present inside the film and the puncturing part.

[0037] The film disposed between the first and second parts in the puncture part is preferably a resin film, and the resin film is preferably at least one type of resin film selected from the group consisting of fluororesin, polyamide, and ultra-high molecular weight polyethylene (UHMWPE).

[0038] The fluororesin may be at least one selected from the group consisting of polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-peralkylvinyl ether copolymer (PFA), polychlorotetrafluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF).

[0039] Tetrafluoroethylene-ethylene copolymer (ETFE) is a copolymer of ethylene and tetrafluoroethylene in a molar ratio of 30 / 70 to 70 / 30. Modified ETFE can also be obtained by copolymerizing other components for the purpose of modification. These other components include fluorine-containing olefins and hydrocarbon olefins. Specifically, these include α-olefins such as propylene and butene; fluorine-containing olefins such as hexafluoropropylene, vinylidene fluoride, perfluorobutylethylene, and trifluorochloroethylene; vinyl ethers such as ethylene vinyl ether, perfluoromethyl vinyl ether, and perfluoropropyl vinyl ether; and fluorine-containing acrylates. These components are copolymerized at approximately 2 to 10 mol% to modify ETFE.

[0040] Examples of the polyamide include polyamide 6, polyamide 66, polyamide 610, polyamide 621, polyamide 11, polyamide 12, copolymer polyamide, monomer casting polyamide, polyamide MXD, and polyamide 46. The polyamide may contain fluorine.

[0041] The thickness of the film is preferably thin, specifically, preferably 5 μm or more, preferably 150 μm or less, preferably 100 μm or less, and more preferably 50 μm or less, because by keeping the film thickness within the above range, resistance during puncture is reduced.

[0042] Examples of methods for bonding the film to the first part or the second part include vulcanization bonding, bonding with an adhesive, and a method using an adhesive film.

[0043] When vulcanization bonding is performed, it is preferable to roughen the area of ​​the film to be bonded and leave the area of ​​the film not to be bonded unroughened. By roughening the surface of the film, the film and rubber can be firmly bonded by vulcanization molding without using adhesives, etc. This bonding is due to the anchor effect of the vulcanized rubber penetrating the inner surface of the roughened film.

[0044] The film surface can be roughened by, for example, irradiating it with an ion beam to destroy the internal molecular structure near the surface (see, for example, Japanese Patent No. 4908617). Examples of treatments for roughening the film surface include glow discharge treatment, plasma treatment (discharge treatment) under atmospheric pressure or in a vacuum, and excimer laser treatment (discharge treatment). In addition to roughening the film surface, treatments for improving the adhesion between the rubber and the film include chemical treatments such as surface treatment with an acid or alkali (e.g., sodium hydroxide), and in such cases, it is preferable to leave the non-adhesive areas of the film untreated.

[0045] The adhesive used to bond the film to the first or second part is not particularly limited, but examples that can be used include thermosetting resin adhesives containing at least one resin selected from phenolic resin, resorcinol resin, furan resin, polyurethane, epoxy resin, and silicone resin; thermoplastic resin adhesives containing at least one resin selected from polyvinyl acetate, polyvinyl chloride, and polyacrylic ester; and elastomer adhesives containing at least one of butadiene acrylonitrile rubber and neoprene.

[0046] One example of a method using an adhesive film having functional groups on its surface is the film. This adhesive film has adhesiveness to rubber due to the action of the functional groups present on its surface. In a method using an adhesive film in which both surfaces of the film have adhesiveness to rubber due to the action of functional groups, as described below, the functional groups on the first part side (leg side) are not deactivated during the first stage of vulcanization molding, but the functional groups on the second part side (top side) are deactivated. Therefore, the adhesive film adheres to the first part but does not adhere to the second part (top side). An adhesive film in which only one side has adhesiveness to rubber due to the action of functional groups may also be used.

[0047] An example of an adhesive film having a functional group is modified ETFE. Examples of the functional group include a carboxyl group, an anhydrous carboxyl group, an epoxy group, a hydroxyl group, an isocyanate group, an ester group, an amide group, an aldehyde group, an amino group, a cyano group, a carbon-carbon double bond, a sulfonic acid group, and an ether group. Commercially available modified ETFE products include Fluon AH-2000 manufactured by Asahi Glass Co., Ltd.

[0048] The legs of the medical rubber stoppers may be laminated with a resin film or coated with a silicone lubricant. Laminating or coating prevents the rubber stoppers from sticking together and allows for smooth transport by a parts feeder when the stoppers are in an inverted position with the top surface of the cap facing the transport surface. Laminating is also possible on the top surface of the cap, not just the legs, and a resin film can be used in the same way as for the legs.

[0049] The thickness of the resin film used for laminating the top surface or legs is preferably 25 μm to 150 μm, more preferably 50 μm to 100 μm. If it is less than 25 μm, the film tends to break frequently during molding, while if it exceeds 150 μm, the dimensional stability of the molded product and the cost increase tend to make it uneconomical.

[0050] Examples of resin films include films of inactive resins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer (ETFE), and modified versions of these, as well as ultra-high density polyethylene (UHMWPE). Among these, fluororesin films are preferred because they are inactive, have excellent heat resistance, chemical resistance, and non-stick properties, and have lower friction resistance than rubber.

[0051] The resin film may be press-molded in a state in which it is superimposed on a sheet-shaped rubber composition, and integrated with the medical rubber part formed after press-molding.

[0052] Sterilization methods for medical rubber stoppers include steam sterilization, ethylene oxide gas sterilization, and gamma ray sterilization, but PTFE has low resistance to gamma rays, so ETFE, modified ETFE, and PCTFE, which have high resistance to gamma ray sterilization, are particularly preferred.

[0053] A metal (e.g., aluminum) or resin cap can be placed on top of the cap, covering the open end of the medical container and the medical rubber stopper. The medical rubber stopper is sealed with a cap, including the open end of the medical container, to prevent mold from adhering to the puncture site where the syringe needle is inserted and then being transferred from the needle to the injectable liquid. Caps that can be used include flip-off caps, pull-top caps, and clean caps. When large amounts of injectable liquid are used, such as in hospitals, it is preferable to use a clean cap, which can be opened with one hand and is easy to operate.

[0054] The cap material can be a thermoplastic resin or a thermoplastic resin composition having a melting point of 100°C to 500°C as measured by ASTM-D2117. This is because it can be easily molded by injection molding. Specific examples include synthetic resins or compositions thereof selected from one or more of the following: polyacetal (POM), polyamide (PA), polyarylate (PAR), polyether-etherketone, ethylene-propylene copolymer, polypropylene (PP), polyethylene terephthalate (PET), liquid crystal polyester (LCP), polyphenylene ether (PPE) or modified polyphenylene ether, polycarbonate (PC), polymethylpentene (PMP), polyurethane (PU), polyethylene (PE), polybutylene phthalate, polysulfone (PS), polyethersulfone (PES), ultra-high molecular weight polyethylene, and copolymers containing cyclic olefin compounds or cross-linked polycyclic hydrocarbons as polymer components. Furthermore, if a thermoplastic resin in which an organic or inorganic reinforcing agent is blended with the thermoplastic elastomer that constitutes the plug is used, a cap with extremely high hardness and strength can be obtained.

[0055] (2) Medical rubber composition The medical rubber stopper of the present disclosure is preferably formed from a medical rubber composition containing (a) a rubber component. (a) The rubber component is preferably butyl rubber, more preferably halogenated butyl rubber, in terms of chemical resistance and gas permeability resistance. Examples of halogenated butyl rubber include chlorinated butyl rubber, brominated butyl rubber, and brominated copolymers of isobutylene and p-methylstyrene. The halogenated butyl rubber is preferably chlorinated butyl rubber or brominated butyl rubber. The chlorinated butyl rubber or brominated butyl rubber is, for example, obtained by adding or substituting chlorine or bromine to the isoprene structure of butyl rubber, specifically the double bond and / or the carbon atom adjacent to the double bond. Butyl rubber is a copolymer obtained by polymerizing isobutylene and a small amount of isoprene.

[0056] (a) The rubber component may contain a rubber component other than butyl rubber. Examples of other rubber components include isoprene rubber, butadiene rubber, styrene-butadiene rubber, natural rubber, nitrile rubbers such as chloroprene rubber and acrylonitrile-butadiene rubber, hydrogenated nitrile rubber, norbornene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylic rubber, ethylene-acrylate rubber, fluororubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, silicone rubber, urethane rubber, polysulfide rubber, phosphane rubber, and 1,2-polybutadiene. These may be used alone or in combination of two or more.

[0057] When other rubber components are used, the content of butyl rubber in the (a) rubber component is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more. In another preferred embodiment, the (a) rubber component consists solely of halogenated butyl rubber.

[0058] The medical rubber composition of the present disclosure preferably contains (b) a crosslinking agent. The (b) crosslinking agent is blended to crosslink the (a) rubber component. The (c) crosslinking agent is not particularly limited as long as it is capable of crosslinking the rubber. Examples of the (c) crosslinking agent include sulfur, metal oxides, resin crosslinking agents, organic peroxides, and triazine derivatives, which may be used alone or in combination of two or more.

[0059] The content of (b) the crosslinking agent in the medical rubber composition of the present disclosure is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more, and even more preferably 0.6 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the (a) rubber component. This is because, when the content of (b) the crosslinking agent is within the above range, a rubber with good rubber properties (hardness, tensile strength, Cset) and good processability (less discoloration) can be obtained.

[0060] The medical rubber composition of the present disclosure preferably does not contain a vulcanization accelerator. This is because the vulcanization accelerator may remain in the final rubber product and leach into the medicinal solution in the vial. Examples of the vulcanization accelerator include guanidine-based accelerators (e.g., diphenylguanidine), thiuram-based accelerators (e.g., tetramethylthiuram disulfide, tetramethylthiuram monosulfide), dithiocarbamate-based accelerators (e.g., zinc dimethyldithiocarbamate), thiazole-based accelerators (e.g., 2-mercaptobenzothiazole, dibenzothiazyl disulfide), and sulfenamide-based accelerators (N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide).

[0061] The medical rubber composition of the present disclosure may contain (c) hydrotalcite. (c) Hydrotalcite functions as a scorch inhibitor during crosslinking of halogenated butyl rubber and also functions to prevent the compression set of medical rubber parts from increasing. Furthermore, hydrotalcite functions as an acid acceptor, absorbing chlorine-based gases and bromine-based gases generated during crosslinking of halogenated butyl rubber and preventing crosslinking inhibition caused by these gases. Note that magnesium oxide, as mentioned above, can also function as an acid acceptor.

[0062] Examples of hydrotalcite include Mg 4.5 Al2(OH) 13 CO3·3.5H2O, Mg 4.5 Al2(OH) 13 CO3, Mg4Al2(OH) 12 CO3·3.5H2O, Mg6Al2(OH) 16 CO3·4H2O, Mg5Al2(OH) 14 CO3·4H2O, Mg3Al2(OH) 10 One or more of Mg-Al hydrotalcites such as CO3·1.7H2O can be used.

[0063] The medical rubber composition of the present disclosure may further contain a filler (d). Examples of the filler (d) include inorganic fillers such as clay and talc, and resin powders of olefin resins, styrene elastomers, and ultra-high molecular weight polyethylene (UHMWPE). Among these, inorganic fillers are preferred, with clay or talc being more preferred. The filler functions to adjust the rubber hardness of the medical rubber part and also functions as an extender to reduce the production cost of the medical rubber part.

[0064] The content of the (d) filler in the medical rubber composition of the present disclosure is preferably set appropriately depending on the rubber hardness, etc., of the intended medical rubber part. The content of the (d) filler in the medical rubber composition of the present disclosure is, for example, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, and preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and even more preferably 100 parts by mass or less, per 100 parts by mass of the (a) rubber component.

[0065] The medical rubber composition of the present disclosure may further contain, in appropriate proportions, colorants such as titanium oxide and carbon black, stearic acid, low-density polyethylene (LDPE) lubricants, processing aids, polyethylene glycol as a crosslinking activator, plasticizers (e.g., paraffin oil), and the like.

[0066] (3) Manufacturing method of medical rubber stopper The medical rubber stopper of the present disclosure is preferably produced by a two-stage molding method using the medical rubber composition. Specifically, the method for producing the medical rubber stopper of the present disclosure includes a step of producing a first part on the leg side and a step of producing a second part on the top side.

[0067] The medical rubber composition of the present disclosure is obtained by kneading (a) the rubber component and other compounding materials added as needed. Kneading can be carried out using, for example, an open roll or an internal kneader. The kneaded product is preferably formed into a ribbon, sheet, or pellet shape, and more preferably formed into a sheet shape.

[0068] A medical rubber stopper having a desired shape can be obtained by press-molding the kneaded material in ribbon, sheet, or pellet form. The crosslinking reaction of the medical rubber composition proceeds during pressing. The molding temperature is, for example, preferably 130°C or higher, more preferably 140°C or higher, and preferably 200°C or lower, more preferably 190°C or lower. The molding time is preferably 2 minutes or longer, more preferably 3 minutes or longer, and preferably 60 minutes or shorter, more preferably 30 minutes or shorter. The molding pressure is preferably 0.1 MPa or higher, more preferably 0.2 MPa or higher, and preferably 10 MPa or lower, more preferably 8 MPa or lower.

[0069] The present disclosure will be described below with reference to the drawings, but the present disclosure is not limited to the embodiments shown in the drawings.

[0070] Figure 1 is an explanatory diagram illustrating an example of a medical plug of the present disclosure, in which Figure 1(a) is a plan view and Figure 1(b) is a cross-sectional view taken along line AA in Figure 1(a).

[0071] The medical plug 1 of the present disclosure has a cylindrical leg portion 5 extending downward from the underside of the cap portion 3. When a medical container is stoppered with the medical plug of the present disclosure, the leg portion 5 fits into the opening of the medical container. In Figure 1(b), the opposing inner surfaces of the cylindrical leg portion 5 are tapered so that the distance between the inner surfaces of the leg portions gradually decreases from the bottom to the top (toward the top surface).

[0072] The cap portion 3 has a circular shape in a plan view and includes a puncture portion 3a that can be punctured with the needle of a syringe, and a flange portion 3b that contacts the upper edge surface of the opening of the medical container when the medical container is capped.

[0073] A protrusion 10 is provided on the top surface of flange portion 3b to prevent it from coming into close contact with other rubber stoppers.

[0074] Puncture portion 3a is an area in cap portion 3 into which an injection needle is inserted to aspirate the liquid medicine inside the container. Puncture portion 3a is circular in plan view and is located in the center of cap portion 3. Puncture portion 3a is also formed in a concave shape extending from the top surface.

[0075] The medical rubber stopper 1 of the present disclosure has, at the puncture portion 3a, a first portion 7 located on the leg portion side and a second portion 9 located on the top surface side of the first portion 7. The first portion 7 and the second portion 9 are adjacent to each other in the vertical direction. In FIG. 1(b), a boundary line 13 indicates the boundary between the first portion 7 and the second portion 9. In the medical stopper 1 of the present disclosure, the first portion 7 and the second portion 9 are not bonded to each other at the puncture portion 3a.

[0076] With this configuration, when the injection needle is removed, the second part 9 elastically deforms, forming a space between the first part 7 and the second part 9. This space serves as a buffer space for accommodating the medicinal liquid leaking from the medical container, and the medical plug 1 of the present disclosure can reduce liquid leakage.

[0077] Figure 2 is an explanatory diagram showing another embodiment of the medical rubber stopper 1 of the present disclosure. Figure 2(a) is a plan view, and Figure 2(b) is a cross-sectional view taken along line AA in Figure 2(a). The medical rubber stopper 1 of this embodiment has one film 15 between the first part 7 and the second part 9. Descriptions of parts of the medical rubber stopper 1 in Figure 2 that are common in configuration to Figure 1 will be omitted.

[0078] In the puncturing portion 3a, the film 15 is adhered to one of the first portion 7 and the second portion 9, and is not adhered to the other of the first portion 7 and the second portion 9.

[0079] Even in this configuration, when the injection needle is removed, the second part 9 elastically deforms, forming a space between the film 15 and one of the first part 7 and second part 9 to which the film is not adhered. This space serves as a buffer space to accommodate medicinal liquid leaking from the medical container, and the medical plug 1 of the present disclosure can reduce liquid leakage.

[0080] The film 15 is disposed so as to span the entire horizontal direction of the puncturing part 3a. The film 15 and the puncturing part 3a are disposed so as to overlap each other in a plan view.

[0081] Figure 3 is an explanatory diagram showing another embodiment of the medical rubber stopper of the present disclosure. Figure 3(a) is a plan view, and Figure 3(b) is a cross-sectional view taken along line AA in Figure 3(a). Description of parts of the medical rubber stopper 1 in Figure 3 that are common in configuration to Figure 1 will be omitted.

[0082] The medical rubber stopper 1 of this embodiment has two films 15a, 15b between the first part 7 and the second part 9, and at the puncture part, the first film 15a in contact with the first part 7 is adhered to the first part 7, the second film 15b in contact with the second part 9 is adhered to the second part 9, and the first film 15a and the second film 15b are not adhered to each other.

[0083] Even in this configuration, when the injection needle is removed, the second part 9 elastically deforms, forming a space between the first part 7 and the second part 9. This space serves as a buffer space for accommodating medicinal liquid leaking from the medical container, and the medical plug 1 of the present disclosure can reduce liquid leakage.

[0084] Figure 4 is an explanatory diagram showing another embodiment of the medical rubber stopper 1 of the present disclosure. Figure 4(a) is a plan view, and Figure 4(b) is a cross-sectional view taken along line BB in Figure 4(a). Descriptions of parts of the medical rubber stopper 1 in Figure 4 that are common in configuration to Figure 1 will be omitted.

[0085] The medical rubber stopper 1 of this embodiment has bifurcated legs 5 extending from the underside of the cap 3. In Figure 4(b), the opposing inner surfaces of the bifurcated legs 5 are tapered so that the distance between the inner surfaces of the legs gradually decreases from the bottom to the top (towards the top surface).

[0086] The medical rubber stopper 1 of this embodiment has one film 15 between the first part 7 and the second part 9. In the puncture part, the film 15 is adhered to one of the first part 7 and the second part 9, and is not adhered to the other of the first part 7 and the second part 9.

[0087] Even in this configuration, when the injection needle is removed, the second part 9 elastically deforms, forming a space between the film 15 and one of the first part 7 and second part 9 to which the film is not adhered. This space serves as a buffer space to accommodate medicinal liquid leaking from the medical container, and the medical plug 1 of the present disclosure can reduce liquid leakage.

[0088] Figures 5 and 6 are explanatory diagrams for schematically illustrating a method for manufacturing a medical rubber stopper according to the present disclosure. Figures 5 and 6 illustrate an example of manufacturing a medical rubber stopper having a single film between the first and second parts, with the film being adhered to the first part at the puncture site but not to the second part, but the method for manufacturing a medical rubber stopper according to the present disclosure is not limited to the embodiment shown in the drawings.

[0089] 5 is an explanatory diagram for schematically illustrating the first step of manufacturing the first part on the stem side of the medical rubber stopper. First, an unvulcanized rubber sheet 21 that will form the first part on the stem side of the medical rubber stopper is prepared. The unvulcanized rubber sheet 21 can be prepared by blending cross-linking components such as cross-linking agents, accelerators, and accelerator assistants for vulcanizing (cross-linking) the rubber, fillers such as silica, clay, and talc for adjusting hardness, and various additives such as processing aids, softeners, and colorants in any desired ratios, kneading them, and forming them into a sheet.

[0090] A film 23 to be placed between the first and second parts of the medical rubber stopper of the present disclosure is prepared. The film 23 is laminated onto an unvulcanized rubber sheet 21. At this time, the side of the film 23 that comes into contact with the rubber sheet 21 is roughened in advance, while the side that does not come into contact with the rubber sheet 21 is not roughened.

[0091] The obtained laminated sheet is fed between lower die 25a and upper die 25b of primary molding die 25 heated to the vulcanization temperature of the rubber. Lower die 25a has a plurality of recesses 29 corresponding to the shape of leg portion 5 of the rubber stopper.

[0092] Next, the lower mold 25a and the upper mold 25b are clamped together to vulcanize and mold the laminated sheet, so that a plurality of leg portions 5 corresponding to the recesses 29 are connected by burrs 31, and a primary molded product 33 is formed in which the film 23 is laminated on the upper side including the entire surface of the connected leg portions 5. The surface of the film 23 that contacts the rubber sheet 21 has been roughened, so that the film 23 is vulcanized and bonded to the first portion formed on the leg side.

[0093] Then, individual leg portions 5 are punched out from the formed primary molded product 33 to produce blank plugs 35. In blank plugs 35, the film 23 is removed from the blank plugs 35 so that it remains only above the puncture portion.

[0094] 6 is an explanatory view for schematically illustrating the process of manufacturing the second part on the top surface side of the medical rubber stopper. An unvulcanized rubber sheet 37 that will form the second part of the medical rubber stopper is prepared.

[0095] The unvulcanized rubber sheet 37 can be the same as the rubber sheet 21 described above.

[0096] The blank plug 35 produced in the previous step is fed between a lower mold 39a having a plurality of recesses 41 corresponding to the shape of the leg portion 5 of a secondary molding mold 39 heated to the vulcanization temperature of the rubber and an upper mold 39b having a plurality of recesses 43 corresponding to the shape of the flange portion 3, and is set in the recesses 41 of the lower mold 39a.

[0097] A rubber sheet 37 is layered on top of the blank plug 35, and the lower mold 39a and upper mold 39b are clamped together to vulcanize and mold the sheet 37, so that a plurality of flange portions 3b corresponding to the recesses 43 are connected by flash 45, and blank plugs 35 (leg portions 5) are vulcanization-bonded to the undersides of the connected flange portions 3b, forming a secondary molded product 38. At this time, the top surface side of the film 23 has not been roughened, so the film 23 is not bonded to the second portion formed on the top surface side.

[0098] Individual cap portions were punched out from the formed secondary molded product 38 to form medical rubber stoppers 1. Thereafter, the manufactured medical rubber stoppers 1 can be commercialized through processes such as cleaning, sterilization, drying, visual inspection, and packaging.

[0099] In the embodiment shown in Figures 5 and 6, the method of adhering the film to the first part or the second part has been described based on a method of roughening the film, but the method of adhering the film to the first part or the second part can be appropriately changed to a method using an adhesive or a method using an adhesive film.

[0100] Figure 7 is a cross-sectional view that schematically illustrates the operation of a vial that has been stoppered with a medical rubber stopper according to one embodiment of the present disclosure. The figure shows a state in which the opening of a vial 50 filled with a pharmaceutical product is sealed with the medical rubber stopper 1. The medical rubber stopper 1 is comprised of a cap 3 and a leg 5. The cap 3 has a puncture portion 3a that can be punctured with the needle of a syringe, and a flange 3b that contacts the upper edge surface of the opening of the medical container 50. The leg 5 protrudes from the underside of the cap 3 (the upper surface in Figure 7) and is fitted into the opening of the medical container.

[0101] The medical rubber stopper 1 of this embodiment has one film 15 between the first part 7 and the second part 9, and in the puncture part 3a, the film 15 is adhered to the first part 7 and is not adhered to the second part 9.

[0102] FIG. 7(a) shows the state in which the needle 49 of the syringe is inserted into the puncture portion 3a to draw the medicinal solution 47 into the syringe, and FIG. 7(b) schematically shows the state in which the needle 49 is withdrawn after the medicinal solution 47 has been drawn into the syringe. When the needle 49 is withdrawn, the frictional force of withdrawing the needle 49 causes the second part 9 of the rubber stopper 1 to elastically deform, creating a space 51 between the film 15 adhered to the first part 7 and the second part 9. Residual liquid in the medical container leaking from the gap where the needle was inserted is contained in this space. As a result, the residual liquid is prevented from leaking out of the medical container.

[0103] In Figure 7, the film 15 is described as being adhered to the first part 7 and not to the second part 9. However, if the film 15 is not adhered to the first part 7 but is adhered to the second part 9, for example, a space 51 will be formed between the film 15 adhered to the second part 9 and the first part 7 when the injection needle 49 is pulled out.

[0104] 8 is a cross-sectional view illustrating the operation of a vial bottle stoppered with a medical rubber stopper according to another embodiment of the present disclosure. The medical rubber stopper 1 of this embodiment has two films 15a, 15b between the first portion 7 and the second portion 9. At the puncture portion 3a, the first film 15a in contact with the first portion 7 is bonded to the first portion 7, the second film 15b in contact with the second portion 9 is bonded to the second portion 9, and the first film 15a and the second film 15b are not bonded to each other.

[0105] FIG. 8(a) shows the state in which the injection needle 49 of the syringe is inserted into the puncture portion 3a to draw the medicinal solution 47 into the syringe, and FIG. 8(b) schematically shows the state in which the injection needle 49 is withdrawn after the medicinal solution 47 has been drawn into the syringe. When the injection needle 49 is withdrawn, the frictional force of withdrawing the injection needle 49 causes the second part 9 of the rubber stopper body 1 to elastically deform, creating a space 51 between the first film 15a adhered to the first part and the second film 15b adhered to the second part. Residual liquid in the medical container leaking from the gap where the injection needle 49 was inserted is contained in this space. As a result, the residual liquid is prevented from leaking out of the medical container. [Example]

[0106] The present disclosure will be described in detail below using examples, but the present disclosure is not limited to the following examples, and all modifications and embodiments that do not deviate from the spirit of the present disclosure are included within the scope of the present disclosure.

[0107] [Medical Rubber Stopper No.1] Butyl rubber was mixed with various additives such as cross-linking agents, fillers, and processing aids, and then kneaded to produce an unvulcanized rubber sheet that would form the first part of the leg portion of the medical plug.

[0108] An ETFE film with one surface roughened was prepared as a film to be provided between the first and second parts of the medical plug. As shown in Figure 5, the ETFE film 23 was laminated so that the roughened surface was in contact with an unvulcanized rubber sheet 21. The resulting laminated sheet was fed between the lower mold 25a and upper mold 25b of a primary molding die heated to the vulcanization temperature of the rubber. At this time, the laminated sheet was positioned so that the ETFE film 23 faced the upper mold 25b and the rubber sheet 21 faced the lower mold 25a.

[0109] The laminated sheet was vulcanized and molded by clamping the lower mold 25a and the upper mold 25b together to form a primary molded product in which a plurality of leg portions 5 were connected by flash 31. An ETFE film 23 was laminated on the entire upper surface of the connected leg portions 5 of the primary molded product.

[0110] Individual leg portions 5 were punched out from the formed primary molded article 33 to prepare blank plugs 35. In blank plug 35, the ETFE film 23 was removed from blank plug 35 so that it remained only above the puncture part.

[0111] As shown in Figure 6, an unvulcanized rubber sheet 37 was prepared to form the second part of the medical rubber stopper. This unvulcanized rubber sheet 37 had the same composition as the rubber sheet 21 that formed the first part.

[0112] The blank plug 35 produced in the previous step was fed into a secondary molding die 39 heated to the vulcanization temperature of the rubber, between a lower die 39a having a plurality of recesses 41 corresponding to the shape of the leg portion 5 and an upper die 39b having a plurality of recesses 43 corresponding to the shape of the flange portion 3, and was set in the recesses 41 of the lower die 39a.

[0113] A rubber sheet 37 is layered on the base plug 35, and the lower mold 39a and upper mold 39b are clamped together to vulcanize and mold the sheet 37, thereby forming a secondary molded product 38 in which multiple flange portions 3b corresponding to the recesses 43 are connected by flash 45 and the base plug 35 (leg portion 5) is vulcanization-bonded to the underside of the connected flange portions 3b.

[0114] Individual cap portions were punched out from the formed secondary molded product 38 to form medical rubber stoppers 1. These medical rubber stoppers 1 were washed, sterilized, dried, and used for testing. In medical rubber stopper No. 1, the film and the first part are bonded at the puncture site, but the film and the second part are not bonded.

[0115] [Medical Rubber Stopper No. 2] Medical rubber stopper No. 2 was prepared in the same manner as medical rubber stopper No. 1, except that a PTFE film was used instead of an ETFE film as the film placed between the first and second parts.

[0116] [Medical Rubber Stopper No. 3] Butyl rubber was mixed with various additives such as cross-linking agents, fillers, and processing aids, and then kneaded to produce an unvulcanized rubber sheet that would form the first part of the leg portion of the medical plug.

[0117] An ETFE film was prepared. The ETFE film was laminated on an unvulcanized rubber sheet. The resulting laminated sheet was fed between the lower mold 25a and the upper mold 25b of a primary molding die heated to the vulcanization temperature of the rubber. At this time, the laminated sheet was positioned so that the ETFE film faced the lower mold 25a and the rubber sheet faced the upper mold 25b.

[0118] The lower mold 25a and the upper mold 25b were clamped together to vulcanize and mold the laminated sheet, thereby forming a primary molded product in which a plurality of leg portions 5 were connected by flash 31. An ETFE film was laminated on the entire lower surface of the connected leg portions 5 of the primary molded product.

[0119] The individual leg portions 5 were punched out from the formed primary molded article 33 to prepare blank plugs 35 .

[0120] An unvulcanized rubber sheet 37 was prepared to form the second part of the medical rubber stopper. This unvulcanized rubber sheet 37 had the same composition as the rubber sheet 21 that formed the first part.

[0121] A rubber sheet 37 is layered on the base plug 35, and the lower mold 39a and upper mold 39b are clamped together to vulcanize and mold the sheet 37, thereby forming a secondary molded product 38 in which multiple flange portions 3b corresponding to the recesses 43 are connected by flash 45 and the base plug 35 (leg portion 5) is vulcanization-bonded to the underside of the connected flange portions 3b.

[0122] Individual cap portions were punched out from the formed secondary molded product 38 to form medical rubber stopper No. 3. This medical rubber stopper No. 3 was washed, sterilized, dried, and used for testing.

[0123] [Medical Rubber Stopper No. 4] An unvulcanized rubber sheet for forming the medical stopper was prepared by compounding and kneading various additives, such as crosslinking agents, fillers, and processing aids, with butyl rubber. This rubber sheet was clamped between upper and lower dies using a one-stage molding method to produce Medical Rubber Stopper No. 4. This Medical Rubber Stopper No. 4 was washed, sterilized, dried, and used for testing.

[0124] [Leakage evaluation test] 1) The injection needle used was a 21G needle manufactured by Terumo Corporation. 2) A medical rubber stopper for a 2 mL vial, a 2 mL vial, a syringe, a crimping tool, and UF water (purified water purified by an ultrafiltration membrane) were prepared. 3) Medical rubber stoppers No. 1 to No. 4 were attached to vials, and aluminum caps were then tightened. New aluminum caps were used each time. 4) 1 ml of UF water was placed in a syringe. 5) The vial bottle, syringe, and injection needle fitted with the medical rubber stopper were each weighed on a balance. 6) A needle was attached to the syringe, and the needle was inserted straight into the puncture portion of the medical rubber stopper, and UF water was poured into the vial. 7) With the needle still inserted, the syringe / vial was turned upside down, the needle was pulled out straight, and any water on the needle was wiped off with a Kimwipe. 8) The vial bottle, syringe, and injection needle fitted with the medical rubber stopper were each weighed on a balance. 9) The total weight of the vials, syringes, and needles measured in 5) was subtracted from the total weight of the vials, syringes, and needles measured in 8) to calculate the amount of liquid leakage. 10) The syringe needle was replaced and steps 2) to 9) were repeated five times, and the amount of leakage was expressed as the average of the five measurements. The amounts of liquid leakage from medical rubber stoppers No. 1 to No. 3 were expressed as index values, with the amount of liquid leakage from medical rubber stopper No. 4 set at 100.

[0125] The properties and leakage amounts of medical rubber stoppers No. 1 to No. 4 were evaluated and the results are shown in Table 1.

[0126] [Table 1]

[0127] Table 1 shows that when the medical rubber stopper formed from the medical rubber composition of the present disclosure is withdrawn, the amount of residual liquid in the medical container leaking from the gap where the injection needle was inserted is small. [Explanation of symbols]

[0128] 1: medical rubber stopper, 3: cap portion, 3a: puncture portion, 3b: flange portion, 5: leg portion, 7: first portion, 9: second portion, 15: film

[0129] The medical rubber stopper of the present disclosure (1) is a medical rubber stopper having a cap portion and a leg portion extending downward from the cap portion, and is characterized in that the medical rubber stopper has, at the puncture portion, a first portion on the leg portion side and a second portion located on the top surface side of the first portion, and the first portion and the second portion are non-adhesive.

[0130] The medical rubber stopper of the present disclosure (2) is the medical rubber stopper described in the present disclosure (1) in which the medical rubber stopper has one film between the first part and the second part, and in the puncture part, the film is adhered to one of the first part and the second part and is not adhered to the other of the first part and the second part.

[0131] The medical rubber stopper of the present disclosure (3) is a medical rubber stopper according to the present disclosure (1), which has at least two films between the first part and the second part, and in the puncture part, a first film in contact with the first part is bonded to the first part, a second film in contact with the second part is bonded to the second part, and the first film and the second film are not bonded to each other.

[0132] The medical rubber stopper of the present disclosure (4) is a medical rubber stopper described in any one of the present disclosures (1) to (3), wherein the cap portion is disk-shaped and has the puncture portion and a flange portion that contacts the upper edge surface of the mouth portion of the medical container.

[0133] The medical rubber stopper of the present disclosure (5) is the medical rubber stopper according to the present disclosure (4), wherein the leg portion is provided inside the flange portion of the cap portion.

Claims

1. A medical rubber stopper having a cap portion and a leg portion extending downward from the cap portion, The medical rubber stopper has, at the puncture portion, a first portion on the leg side and a second portion located on the top surface side of the first portion, the first portion and the second portion being non-adhered, and is formed from a medical rubber composition containing (a) a rubber component and (b) a crosslinking agent.

2. (a) A medical rubber stopper as described in claim 1, wherein the rubber component contains halogenated butyl rubber.

3. the medical rubber stopper has one film between the first part and the second part, 2. The medical rubber stopper according to claim 1, wherein the film is adhered to one of the first and second parts at the puncture portion and is not adhered to the other of the first and second parts.

4. The medical rubber stopper according to claim 1, wherein the medical rubber stopper has at least two films between the first part and the second part, and in the puncture part, a first film in contact with the first part is bonded to the first part, a second film in contact with the second part is bonded to the second part, and the first film and the second film are not bonded to each other.

5. A medical rubber stopper body as described in claim 1, wherein the first part and the second part are non-adhesive at the puncture site and adhesive in areas other than the puncture site.

6. A medical rubber stopper body as described in claim 1, wherein the puncture portion is located in the center of the cap portion when viewed in a plane.

7. 7. The medical rubber stopper according to claim 1, wherein the cap portion is disk-shaped and has the puncture portion and a flange portion that contacts the upper edge surface of the opening of the medical container.

8. 8. The medical rubber stopper according to claim 7, wherein the leg portion is provided inside a flange portion of the cap portion.

Images