Medical cap and manufacturing method thereof

Abstract

To provide a medical cap having an elastic stopper and an outer frame body for holding the elastic stopper therein, and having no liquid leakage at the time of needle stick, and having an excellent holding force against needle pull-out, and a method for producing the same.SOLUTION: The present invention is a medical cap 10 which includes an elastic stopper 2, and an outer frame body 1 including at least an upper frame part 11 for supporting a peripheral edge part 26 of the elastic stopper 2 from an upper surface side and a lower frame part 12 for supporting the peripheral edge part 26 from a lower surface side. The lower frame part 12 has a flange part 12c protruding to the outside of the outer frame body 1, and a pressing part 12b for pressing the lower surface side of the peripheral edge part 26 of the elastic stopper 2, and a plurality of gate marks are formed on an outer surface of the pressing part 12b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a medical cap for use with pharmaceutical containers such as infusion containers, blood collection tubes, and vials, and a method for manufacturing the same, and more particularly to a medical cap for medical use that does not leak liquid when punctured with a needle and has excellent retention force against needle withdrawal, and a method for manufacturing the same. [Background technology]

[0002] Drug containers used in the medical field, such as liquid medicine bottles and infusion bottles for intravenous drips, often use caps that include rubber stoppers or elastic stoppers (e.g., rubber or elastomer resin) attached to the inside of an outer frame to allow the liquid medicine to be extracted with a needle. The latter type of cap is attached by welding the outer frame to the mouth of the drug container. During use, a syringe needle equipped with an extraction tube is pierced through the elastic stopper, and the drug container is placed on top and the cap on the bottom, allowing the liquid medicine inside the container to be extracted via the extraction tube. Furthermore, such medical caps are required to be airtight to prevent leakage of the liquid medicine or infusion and to prevent deterioration due to exposure to air.

[0003] An example of such a medical cap is a puncture stopper having a needle puncture portion made of a thermoplastic synthetic resin elastomer and an outer peripheral portion that defines the needle puncture portion (see Patent Document 1 below). This needle puncture stopper is capable of preventing leakage of liquid from a container even when the stopper is heat-treated by deforming the needle puncture portion by applying pressure in the direction of needle puncture.

[0004] Furthermore, Patent Documents 2 and 3 below disclose an infusion stopper comprised of a rubber stopper and a plastic support that forms the outer shell, in which the rubber stopper is set in an injection mold, and the support that forms the outer shell is integrated with the rubber stopper and the support by a one-step insert molding method. By adopting such a configuration, the infusion stoppers of Patent Documents 2 and 3 are said to be able to provide an infusion stopper that has excellent fit between the rubber stopper and the support and is highly safe.

[0005] In Patent Document 1, the gate for injecting molten resin into the mold when molding the stopper body corresponding to the outer periphery is provided at a position where a flange on the leg portion of the stopper body will be molded (see Figures 2 and 5 to 7 of Patent Document 1). Also, in Patent Documents 2 and 3, the gate for injecting molten plastic into the mold when molding the support body is provided at a position where a flange on the support body will be molded (see Figure 2 of Patent Document 2 and Figures 2 to 4 of Patent Document 3).

[0006] However, when a medical cap is manufactured by providing a gate at the position where the stopper body or the flange of the support is molded and injecting molten resin, etc., there are problems such as liquid leakage when a needle is inserted and weak holding power against needle withdrawal. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-130614 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-212204 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-212845 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a medical cap having an elastic stopper and an outer frame that holds the elastic stopper internally, which does not leak liquid when punctured with a needle and has excellent retention power against needle withdrawal, and a method for manufacturing the same. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the medical cap of the present invention is a medical cap comprising an elastic stopper and an outer frame body having at least an upper frame portion that supports the peripheral portion of the elastic stopper from the top side and a lower frame portion that supports it from the bottom side, and is characterized in that it has a flange portion that protrudes outward from the outer frame body and a pressing portion that presses the bottom side of the peripheral portion of the elastic stopper, and that multiple gate marks are formed on the outer surface of the pressing portion.

[0010] In the above-described configuration, at least a part of the outer surface of the pressing portion may be a tapered surface, and the gate mark may be provided on the tapered surface.

[0011] In the above configuration, at least a part of the outer surface of the pressing portion may be curved, and the gate mark may be provided on the curved surface.

[0012] In the above configuration, at least a part of the outer surface of the pressing portion may be a horizontal surface, and the gate mark may be provided on the horizontal surface.

[0013] In the above-mentioned configuration, it is preferable that the lower surface of the peripheral edge of the elastic stopper is pressed by the pressing portion, and at least the lower surface of the elastic stopper is deformed into a convex or concave shape.

[0014] In order to solve the above-mentioned problems, the manufacturing method of a medical cap according to the present invention is a manufacturing method of a medical cap comprising an elastic stopper and an outer frame body having at least an upper frame portion that supports the peripheral portion of the elastic stopper from the upper side and a lower frame portion that supports it from the lower side, wherein the lower frame portion of the medical cap has a flange portion that protrudes outward from the outer frame body and a pressing portion that presses the lower side of the peripheral portion of the elastic stopper, and is characterized in that using a common mold and a first mold, an upper frame portion having a mounting portion on its inner wall on which the elastic stopper can be placed, the elastic stopper is placed inside the upper frame portion with its upper surface facing downward, molten resin is injected through multiple molten resin injection gates of the second mold, the lower frame portion is molded so that multiple gate marks are formed on the outer surface of the pressing portion, and the outer frame body is formed.

[0015] In the above configuration, the second mold may have a draft angle to make at least a portion of the pressing portion of the lower frame portion into a tapered surface, and the molten resin injection gate may be provided at the draft angle.

[0016] In addition, in the above configuration, at least a portion of the molding surface that molds the pressing portion of the lower frame portion in the second mold is curved to make at least a portion of the pressing portion a curved surface, and the multiple molten resin injection gates may be provided on the curved molding surface of the second mold.

[0017] In addition, in the above configuration, at least a portion of the molding surface of the second mold that molds the pressing portion of the lower frame portion is flat to make at least a portion of the pressing portion a horizontal surface, and the multiple molten resin injection gates may be provided on the flat molding surface of the second mold.

[0018] In the above-described configuration, the molten resin injection gate is preferably provided on the outer peripheral edge of the ring-shaped protrusion in the vicinity of the ring-shaped protrusion. [Effects of the Invention]

[0019] The medical cap of the present invention comprises an elastic stopper and an outer frame having at least an upper frame supporting the peripheral edge of the elastic stopper from above and a lower frame supporting the peripheral edge from below. The lower frame has a flange protruding outward from the outer frame and a pressing portion pressing against the lower side of the peripheral edge of the elastic stopper, and a plurality of gate marks are formed on the outer surface of the pressing portion.

[0020] Here, the upper frame is formed in advance using a common mold and a first mold. The lower frame is formed using the common mold and a second mold after the elastic stopper is placed inside the upper frame. The second mold has a ring-shaped protrusion that can press against the peripheral portion on the underside of the elastic stopper, so that when the common mold and the second mold are closed, at least the underside of the elastic stopper can be deformed into a convex shape and placed in an extruded state. This allows a pressing portion to be formed in the lower frame that can continuously press against the underside of the peripheral portion of the elastic stopper.

[0021] With this method of molding the outer frame, the elastic stopper is held in place with compressive stress (crimping force) acting toward the center on the underside of the peripheral edge of the elastic stopper due to the pressure from the pressing portion. As a result, the adhesion between the elastic stopper and the inner wall of the outer frame is improved. Furthermore, since at least the underside of the elastic stopper is in a convex or concave bulge, a restoring force acts on the underside. As a result, the holding force and restoring force against needle withdrawal are improved, and resealability after needle withdrawal can also be improved.

[0022] Furthermore, in conventional medical caps, the molten resin injection gate is positioned in the second mold so that a gate mark is formed on the flange. In the present invention, however, the molten resin injection gate is positioned so that a gate mark is formed on the outer surface of the pressing portion. This allows the pressing portion to mold a lower frame portion that applies a stronger compressive stress (crimping force) to the elastic stopper than conventional methods. As a result, a medical cap and its manufacturing method can be provided that further prevents liquid leakage during needle puncture and has excellent retention against needle withdrawal. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1(a) is a schematic cross-sectional view illustrating a medical cap according to one embodiment of the present invention, and FIG. 1(b) is a plan view of the medical cap as viewed from the liquid-contacting surface side. [Figure 2] Figure 2 is a cross-sectional view showing a schematic representation of gate marks in the medical cap, where (a) shows a convex shape, and (b) shows a case where a burr is formed around a concave shape. [Figure 3] FIG. 3 is a cross-sectional view illustrating an elastic plug in the medical cap. [Figure 4] 10A and 10B are cross-sectional views for explaining the manufacturing method of the medical cap, in which FIG. 10A shows the state in which the upper frame portion is molded using the first upper mold and the common lower mold, FIG. 10B shows the state in which the first upper mold and the common lower mold are opened, and FIG. 10C shows the state in which the elastic stopper body is placed on the upper frame portion. [Figure 5] 10A and 10B are cross-sectional views for explaining the manufacturing method of the medical cap, in which FIG. 10A shows the second upper mold and the common lower mold to which the upper frame portion on which the elastic stopper is placed is fixed, FIG. 10B shows the state in which the lower frame portion is molded using the second upper mold and the common lower mold, and FIG. 10C shows the state in which the second upper mold and the common lower mold are opened after the lower frame portion has been molded. [Figure 6] FIG. 4 is an enlarged view of a main part showing a second upper mold. [Figure 7] 10 is a cross-sectional view for explaining the method for manufacturing a medical cap according to Comparative Example 1, showing a state in which a lower frame portion is formed using a second upper mold and a common lower mold. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] (Medical cap) A medical cap according to the present embodiment will be described below with reference to Figures 1 to 3. However, parts unnecessary for the description are omitted, and some parts are illustrated enlarged or reduced for ease of description. Figure 1(a) is a schematic cross-sectional view for explaining a medical cap according to one embodiment of the present invention, and Figure 1(b) is a plan view of the medical cap as viewed from the liquid-contacting surface side. Figure 2 is a cross-sectional view schematically showing gate marks in the medical cap, where Figure 2(a) shows a case where the gate marks are convex, and Figure 2(b) shows a case where a burr is formed around a concave. Figure 3 is a cross-sectional view schematically showing an elastic stopper in the medical cap.

[0025] As shown in FIG. 1(a), the medical cap 10 according to this embodiment comprises at least an outer frame 1 and an elastic stopper 2. The outer frame 1 is capable of holding the elastic stopper 2 therein and comprises an upper frame 11 that supports at least the peripheral edge 26 of the elastic stopper 2 from the needle insertion surface 21 (upper surface) and a lower frame 12 that supports it from the liquid contact surface 22 (lower surface). The elastic stopper 2 is held by the outer frame 1 with the needle insertion surface 21 deformed convexly and the liquid contact surface 22 deformed concavely. The degree of deformation of the needle insertion surface 21 and the liquid contact surface 22 is not particularly limited. For example, the needle insertion surface 21 may be deformed convexly overall or with only a central portion deformed convexly. The liquid contact surface 22 may be deformed concavely overall or with only a central portion deformed concavely.

[0026] The upper frame portion 11 and the lower frame portion 12 are welded together at their contact surfaces, and as a result, the upper frame portion 11 and the lower frame portion 12 form an integrated structure to form the outer frame body 1. Here, the term "welded" refers to a state in which the upper frame portion 11 and the lower frame portion 12 are joined together at their contact surfaces after molding of the lower frame portion 12, as will be described later, as a result of the surface of the upper frame portion 11 in contact with it being melted by the heat of the molten resin injected when molding the lower frame portion 12 by injection molding or the like.

[0027] The lower frame 12 includes a main body 12a, a pressing portion 12b, and a flange 12c. The lower frame 12 is preferably a rigid molded body, which allows the medical cap 10 to have excellent shape stability.

[0028] The main body 12a has an overall cylindrical shape. A flange 12c is provided at one end of the main body 12a, protruding outward from the main body 12a. A pressing portion 12b is provided inside the main body 12a, pressing against a stepped portion 25 (details of which will be described later) of the elastic stopper 2. The pressing portion 12b presses against the upper surface of the peripheral edge 26 of the elastic stopper 2 and the stepped portion 25, thereby maintaining the liquid-contacting surface 22 in a concave shape. This prevents liquid leakage during needle insertion and improves retention against needle withdrawal. The outer surface of the pressing portion 12b is provided with two tapered surfaces: a first tapered surface 13 and a second tapered surface 14, each with a different inclination angle. The first tapered surface 13 and the second tapered surface 14 are tapered away from the flange 12c (i.e., toward the liquid-contacting surface 22 of the elastic stopper 2).

[0029] The inclination angle of the first tapered surface 13 relative to the horizontal plane is set to be smaller than the inclination angle of the second tapered surface 14 relative to the horizontal plane. The inclination angles of the first tapered surface 13 and the second tapered surface 14 are preferably set so that the lower frame portion 12 can be easily released from the mold when the mold is opened in the molding process of the lower frame portion 12. More specifically, the inclination angle of the first tapered surface 13 is preferably in the range of more than 0 degrees and not more than 89 degrees, and more preferably in the range of not less than 70 degrees and not more than 85 degrees. Furthermore, the inclination angle of the second tapered surface 14 is preferably in the range of not less than 10 degrees and not more than 89 degrees, and more preferably in the range of not less than 70 degrees and not more than 85 degrees.

[0030] As shown in FIG. 1(b), four gate marks 19 are provided on the first tapered surface 13 so as to be equally spaced from one another. The number of gate marks 19 is not particularly limited, as long as a plurality of gate marks are provided. Here, in this specification, the term "gate mark" refers to a mark having an uneven shape formed on the molded body (in this embodiment, the lower frame portion 12) as a mark of a gate, which is an injection port for molten resin into the cavity of a mold. The shape of the gate mark 19 in a plan view is circular. Here, the shape and size of the gate mark 19 in a plan view, etc., are determined depending on the shape and area of ​​the gate opening, which will be described later.

[0031] More specifically, examples of gate marks 19 include those having the outer shapes shown in Figures 2(a) and 2(b). That is, for example, the gate mark 19' shown in Figure 2(a) has an outer shape that is a convex portion, such as a substantially conical shape. Gate marks 19' having such a shape can be formed, for example, in a cold runner system in which a runner is cooled in a mold and removed together with a molded product, when the gate is a pinpoint gate (or a pin gate). Gate marks 19' can also be formed in a hot runner system in which the sprue, runner, and gate are heated, when the gate is an open gate that does not have a mechanical opening and closing mechanism and is always open. On the other hand, the gate mark 19" shown in Figure 2(b) has a recess 19a that is generally circular or elliptical, and a burr 19b that surrounds the recess 19a. Uniform or non-uniform ripple-like fine lines (not shown) are also formed around the recess 19a and burr 19b. The height of the burr 19b may be either uniform or non-uniform. A gate mark 19" having such a shape can be formed, for example, in a hot runner system using a valve gate equipped with a mechanical opening and closing mechanism. The present invention is not limited to the shapes of the gate mark 19 shown in Figures 2(a) and 2(b), and may include various other shapes.

[0032] In this embodiment, the outer surface of the pressing portion 12b is provided with two tapered surfaces, the first tapered surface 13 and the second tapered surface 14, which have different inclination angles, but the present invention is not limited to this. For example, the outer surface of the pressing portion 12b may be formed with a single tapered surface.

[0033] The lower frame 12 is in contact with the elastic stopper 2 at the pressing portion 12b, and the two are welded together. This prevents gaps from being created due to misalignment between the elastic stopper 2 and the outer frame 1 when a needle is inserted into the needle insertion surface 21 of the elastic stopper 2. As a result, leakage is further prevented and airtightness is ensured. Note that "welded" here means that the surface of the elastic stopper 2 in contact with it is melted by the heat of the molten resin injected when molding the lower frame 12 by injection molding or the like, resulting in a bond between the elastic stopper 2 and the lower frame 12 at their contact surfaces after molding.

[0034] The upper frame 11 includes a cylindrical main body 11a and a mounting portion 17 provided at the bottom of the main body 11a. The mounting portion 17 allows the elastic stopper 2 to be mounted when the elastic stopper 2 is inserted into the preformed upper frame 11. The mounting portion 17 is provided so as to protrude in an annular shape from the main body 11a toward the center. This allows the elastic stopper 2 to support the peripheral edge 26 on the needle insertion surface 21 side of the elastic stopper 2. As a result, for example, the elastic stopper 2 can be prevented from being pushed out of the upper frame 11 during molding of the lower frame 12 (details will be described later). Note that, although the present embodiment illustrates a case in which the mounting portion 17 is annular, the present invention is not limited thereto. For example, multiple mounting portions may be provided at predetermined intervals. In this case, the distance between adjacent mounting portions is not particularly limited as long as it is possible to support the elastic plug 2 to such an extent that it is not pushed out from the upper frame portion 11 when the lower frame portion 12 is molded.

[0035] The mounting portion 17 is provided with an annular protrusion 17a. The protrusion 17a is provided so as to be able to fit into an annular groove provided on the needle piercing surface 21 side of the peripheral edge 26 of the elastic stopper 2. This prevents gaps from being generated due to misalignment between the elastic stopper 2 and the outer frame 1 when a needle is pierced on the needle piercing surface 21. As a result, liquid leakage is further prevented and airtightness is ensured.

[0036] The upper frame portion 11 is welded to the lower frame portion 12 at the contact surface, but is not welded to the contact surface with the elastic stopper 2. The upper frame portion 11 may also be of a pull-top type.

[0037] As the material for the outer frame 1 (upper frame portion 11 and lower frame portion 12), synthetic resins whose safety for medical use has been established can be suitably used. Among these, thermoplastic resins are generally used. Specifically, resins conventionally used for medical use, such as polyethylene, polypropylene, and PET (polyethylene terephthalate) resin, are preferred, but the present invention is not limited to these. Furthermore, since the upper frame portion 11 and the lower frame portion 12 are welded together to form the outer frame 1, it is preferable that the constituent materials used for each portion be the same material or compatible materials. Furthermore, optional components such as colorants may be added to one or both of the upper frame portion 11 and the lower frame portion 12.

[0038] The elastic stopper 2 is housed inside the outer frame 1 with the needle puncture surface 21 facing up and the liquid contact surface 22 facing down. Here, the "needle puncture surface" refers to the surface that is punctured by a puncture needle when the medical cap 10 according to this embodiment is attached to a medicine container and a medicinal solution or the like is dispensed. The "liquid contact surface" refers to the surface that comes into contact with the medicinal solution or the like stored in the medicine container. The needle puncture surface 21 is provided with a recess 21a that serves as a position indicator when the puncture needle is used to puncture the surface. There is no particular limitation on the number of recesses 21a, and it is sufficient that at least one recess 21a is provided.

[0039] The overall shape of the elastic stopper 2 is not particularly limited, but in this embodiment, it is substantially cylindrical as shown in Fig. 3. However, a step 25 is provided on the liquid-contacting surface 22 side of the peripheral edge 26. In addition, an annular groove 27 is provided on the needle-insertion surface 21 side, which enables the elastic stopper 2 to fit into the annular protrusion 17a on the mounting portion 17 of the upper frame 11. The shape of the elastic stopper 2 is not limited to the form shown in Fig. 3; for example, the elastic stopper may have a flat shape on both the needle-insertion surface and the liquid-contacting surface.

[0040] In the medical cap 10 according to this embodiment, the elastic stopper 2 is housed within the outer frame 1, with the step 25 on the liquid-contacting surface 22 side of the peripheral edge 26 of the elastic stopper 2 pressed by the pressing portion 12b of the lower frame 12. As a result, compressive stress (crimping force) acts on the elastic stopper 2 toward its center, causing the needle puncture surface 21 and the liquid-contacting surface 22 to deform concavely. Furthermore, the lower frame 12 is molded by positioning the molten resin injection gate in the second mold so that a gate mark 19 is formed on the outer surface of the pressing portion 12b. Therefore, compared to a lower frame molded with the molten resin injection gate positioned so that the gate mark 19 is formed on the flange 12c, for example, it is possible to mold a lower frame 12 that can apply greater compressive stress to the elastic stopper 2. As a result, the medical cap 10 according to this embodiment can better prevent fluid leakage during needlestick puncture and further improve retention against needle withdrawal than conventional medical caps.

[0041] (Manufacturing method of medical caps) Next, a method for manufacturing the medical cap according to this embodiment will be described with reference to FIGS. Fig. 4 is a cross-sectional view illustrating a method for manufacturing a medical cap according to an embodiment, in which Fig. 4(a) shows the molding of an upper frame using a first upper mold and a common lower mold, Fig. 4(b) shows the first upper mold and the common lower mold after they are opened, and Fig. 4(c) shows the placement of an elastic stopper on the upper frame. Fig. 5 is a cross-sectional view illustrating a method for manufacturing a medical cap, in which Fig. 5(a) shows the second upper mold and the common lower mold to which the upper frame with the elastic stopper placed is fixed, Fig. 5(b) shows the molding of a lower frame using the second upper mold and the common lower mold, and Fig. 5(c) shows the molding of the lower frame after the lower frame is molded and the second upper mold and the common lower mold after they are opened. Fig. 6 is an enlarged view of a main part of the second upper mold.

[0042] The method for manufacturing the medical cap 10 includes the steps of molding the upper frame portion 11, placing the elastic stopper 2 on the molded upper frame portion 11, and molding the lower frame portion 12.

[0043] As shown in FIG. 4(a), the molding process for the upper frame portion 11 is performed by injection molding the upper frame portion 11 using a first upper mold 32 and a common lower mold 31. The first upper mold 32 is a core (convex mold), and the common lower mold 31 is a cavity (concave mold). The first upper mold 32 and the common lower mold 31 are configured such that, when closed, a cavity capable of molding the upper frame portion 11 is formed. The common lower mold 31 also has a recess 34 that is circular in plan view to enable the needle insertion surface 21 side of the elastic stopper 2 to be deformed into a convex shape. The depth of the recess 34 is not particularly limited, but is typically 0.5 mm to 3 mm, preferably 0.5 mm to 1 mm. The diameter of the recess 34 is also not particularly limited, but is set to be smaller than the diameter of the needle insertion surface 21 of the elastic stopper 2.

[0044] Molten resin 33, which is the resin that forms the constituent material of the upper frame portion 11, passes through a sprue and a runner in the first upper mold 32 and is injected into the cavity from a gate. The injection pressure is not particularly limited and can be set as needed. The injected molten resin 33 is cooled for a predetermined time. The cooling time is not particularly limited and can be set as needed.

[0045] Next, as shown in Figure 4(b), the first upper mold 32 and the common lower mold 31 are opened, thereby forming the upper frame 11. The upper frame 11 is provided with a mounting portion 17 on which the elastic plug 2 is to be mounted.

[0046] 4(c), the elastic stopper 2 is placed on the mounting portion 17 of the upper frame portion 11 with its liquid-contacting surface (lower surface) 22 facing upward. There are no particular limitations on the method for manufacturing the elastic stopper 2, and it can be manufactured, for example, by compression molding or injection molding, in which a thermoplastic elastomer is crushed.

[0047] Next, as shown in Figure 5(a), the lower frame portion 12 is molded. A second upper mold 35 and a common lower mold 31 are used to mold the lower frame portion 12. The second upper mold 35 and the common lower mold 31 are structured so that when they are closed together, a cavity is formed in which the upper frame portion 11 can be molded.

[0048] 6, the second upper mold 35 is provided with a ring-shaped protrusion 36 for pressing the peripheral edge 26 of the liquid contact surface 22 of the elastic stopper 2. The ring-shaped protrusion 36 also has the function of preventing the molten resin from flowing into the gap between the liquid contact surface 22 of the elastic stopper 2 and the second upper mold 35 by bringing the ring-shaped protrusion 36 into contact with the peripheral edge 26 of the liquid contact surface 22.

[0049] The outer diameter r of the ring-shaped protrusion 36 is set appropriately depending on the shape and size of the upper frame 11 to be formed, but is preferably smaller than the diameter of the needle puncture surface 21 of the elastic stopper 2. However, if the outer diameter r is too small, the annular frame 18 of the upper frame 11 will be formed larger than necessary, which may result in the area that functions as the needle puncture surface becoming too small and reducing convenience during needle puncture.

[0050] The height h of the ring-shaped protrusion 36 is not particularly limited and is set appropriately depending on the size of the elastic stopper 2, the shape of the lower frame portion 12 to be molded, and other factors. It is generally preferable that the height be within a range of 0.3 to 6 mm, and more preferably within a range of 0.8 to 4 mm. Setting the height h to 6 mm or less can prevent difficulty in closing the second upper mold 35 and the common lower mold 31. On the other hand, setting the height h to 0.3 mm or more can prevent insufficient pressure being applied to the elastic stopper 2, preventing the occurrence of compressive stress directed toward the center of the elastic stopper 2.

[0051] The outer peripheral edge of the ring-shaped protrusion 36 is provided with a draft slope 37. The draft slope 37 is composed of a first draft slope 37a and a second draft slope 37b, which have different inclination angles relative to the horizontal plane. By providing the draft slope 37 on the outer peripheral edge of the ring-shaped protrusion 36, the second upper mold 35 can be easily released from the lower frame 12 when the second upper mold 35 and the common lower mold 31 are opened.

[0052] The draft angle of the first draft slope 37a (the angle between the inclined surface of the first draft slope 37a and the perpendicular line) and the draft angle of the second draft slope 37b (the angle between the inclined surface of the second draft slope 37b and the perpendicular line) are not particularly limited and may be set appropriately depending on the constituent material of the lower frame portion 12, the presence or absence of a texturing process, etc. Typically, the draft angle of the first draft slope 37a is greater than 0 degrees and less than 89 degrees, and preferably is greater than 70 degrees and less than 95 degrees. Furthermore, the draft angle of the second draft slope 37b is greater than 10 degrees and less than 89 degrees, and preferably is greater than 70 degrees and less than 85 degrees. In this embodiment, the draft angle of the first draft slope 37a is set to be greater than the draft angle of the second draft slope 37b.

[0053] In this embodiment, the draft 37 is configured by two drafts, a first draft 37a and a second draft 37b, which have different draft angles, but the present invention is not limited to this. For example, the draft 37 may be configured by a single draft.

[0054] A plurality of molten resin injection gates 35a are provided at equal intervals on the first draft slope 37a of the second upper mold 35 for injecting molten resin, which is the constituent material of the lower frame portion 12. By providing the molten resin injection gates 35a on the first draft slope 37a, it is possible to form a pressing portion 12b that can apply a greater compressive stress (crimping force) to the elastic plug than conventionally. The molten resin injection gates 35a are not particularly limited, and for example, a pinpoint gate, an open gate, a valve gate, etc. can be used.

[0055] The second upper mold 35 is also provided with a sprue 35c through which molten resin injected from an injection molding machine or the like flows, and a runner 35b as a passageway for guiding the molten resin from the sprue 35c into the cavity.

[0056] As shown in FIG. 5(b), when the second upper mold 35 and the common lower mold 31 are closed, the ring-shaped protrusion 36 abuts against the peripheral edge 26 of the liquid-contacting surface 22 of the elastic stopper 2, deforming it. This causes the liquid-contacting surface 22 side to deform convexly. The common lower mold 31 also has a recess 34, which prevents the needle puncture surface 21 of the elastic stopper 2 from being supported when the second upper mold 35 and the common lower mold 31 are closed. Therefore, the needle puncture surface 21 side also deforms convexly when the molds are closed (see FIG. 5(b)). Furthermore, by abutting the ring-shaped protrusion 36 against the peripheral edge 26 of the liquid-contacting surface 22 of the elastic stopper 2, it is possible to prevent the molten resin from flowing into the gap between the liquid-contacting surface 22 of the elastic stopper 2 and the second upper mold 35.

[0057] Next, molten resin 38, which is the resin that will form the lower frame portion 12, is injected into the cavity formed by closing the mold. The molten resin 38 passes through the sprue 35c and runner 35b in the second upper mold 35 and is injected into the cavity through the molten resin injection gate 35a. Four molten resin injection gates 35a are provided, spaced equally apart from one another. While the present embodiment has been described with reference to an example in which four molten resin injection gates 35a are provided, the present invention is not limited to this configuration; at least a plurality of gates 35a may be provided. Therefore, for example, three molten resin injection gates 35a may be provided at equal intervals from one another. The injection pressure is not particularly limited and can be set as needed. The injected molten resin is cooled for a predetermined period of time. The cooling time is not particularly limited and can be set as needed. After the mold is opened, the lower frame portion 12 is formed as shown in FIG. 5(c).

[0058] Either a hot runner system or a cold runner system may be used in molding the second upper mold 35 using the common lower mold 31 and the second upper mold 35. Furthermore, when the hot runner system is used, either an internal heating system in which the sprue 35c, the runner 35b, and the molten resin injection gate 35a are heated from the inside, or an external heating system in which they are heated from the outside, may be used.

[0059] As a result of the above, the outer frame body 1 in which the upper frame portion 11 and the lower frame portion 12 are integrated is formed, and the medical cap 10 according to the present embodiment is obtained.

[0060] (Other matters) In the above-described embodiment, the outer surface of the pressing portion is provided with two tapered surfaces, a first tapered surface and a second tapered surface, each having a different inclination angle. However, the present invention is not limited to this embodiment. For example, the outer surface of the pressing portion may be provided with a curved surface, such as a rounded surface and / or a reverse rounded surface, at least in part.

[0061] In this case, at least a portion of the molding surface of the second upper mold that molds the pressing portion is curved so that at least a portion of the outer surface of the pressing portion is curved with an R-surface and / or an inverse R-surface. Furthermore, the molten resin injection gate position is provided on the curved molding surface of the second upper mold. As a result, a gate mark is formed on the curved R-surface and / or an inverse R-surface on the outer surface of the pressing portion.

[0062] The first tapered surface on the outer surface of the pressing portion may be a horizontal surface. In this case, at least a portion of the molding surface of the second upper mold that molds the pressing portion is horizontally flat so that part of the outer surface of the pressing portion is a horizontal surface. Furthermore, the molten resin injection gate position is provided on the flat molding surface of the second upper mold. As a result, a gate mark is formed on the horizontal surface of the outer surface of the pressing portion.

[0063] In these configurations, the lower frame can be formed so that the pressing portion can apply a stronger compressive stress (crimping force) to the elastic stopper than before, thereby further preventing liquid leakage in the event of needle stick and improving retention against needle withdrawal. [Example]

[0064] Preferred examples of the present invention are described in detail below. However, the materials and blending amounts described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0065] Example 1 In this example, the medical cap 10 shown in FIG. 1(a) was manufactured according to the method shown in FIGS. 4 to 6. The upper frame portion 11 of the outer frame 1 was made of high-density polyethylene, and the lower frame portion 12 was made of low-density polyethylene. The elastic stopper 2 was made of a thermoplastic elastomer resin. An injection molding machine (product name: DC100 / 200) manufactured by Nissei Plastic Industrial Co., Ltd. was used as the molding machine. The resulting medical cap had four convex (approximately conical) gate marks formed at equal intervals on the first tapered surface 13. Fifty samples of the medical cap 10 according to this example were prepared.

[0066] The molding conditions for the upper frame portion 11 are as follows. Injection molding temperature: 240℃ Injection pressure: 4.0 MPa Injection time: 3.5 seconds 1st upper mold temperature: 20℃ Common lower mold temperature: 25℃

[0067] The molding conditions for the lower frame portion 12 are as follows: The gate of the second upper mold 53 was a pinpoint gate. Injection molding temperature: 240℃ Injection pressure: 4.8MPa Injection time: 4.0 seconds Second upper mold temperature: 20℃ Common lower mold temperature: 25℃

[0068] (Comparative Example 1) In this comparative example, a second upper mold 35' shown in FIG. 7 was used instead of the second upper mold 35 shown in FIGS. 4 to 6. More specifically, a second upper mold 35' was used in which the molten resin injection gate 35a' was provided on the surface where the bottom surface of the flange portion 12c would be formed, rather than on the draft angle 37. Except for this, the medical cap according to this comparative example was produced in the same manner as in Example 1. In the obtained medical cap, four convex gate marks were formed at equal intervals on the bottom surface of the flange portion 12c. The number of samples of the medical cap according to this comparative example was 10.

[0069] (Lens needle leakage test) The medical caps obtained in Example 1 and Comparative Example 1 were sterilized in an autoclave at 106°C for 35 minutes. Next, each medical cap was attached to a test container containing 100cc of water and sealed using a sealing machine. After that, the test container was hung with the medical cap side facing downwards.

[0070] Next, a resin needle for an infusion set (outer diameter approximately 5 mm) was punctured into the center of the elastic stopper of the medical cap, and after leaving it in that state for 6 hours, the needle was removed. The medical cap of the hanging test container was visually observed for 2 minutes to determine whether or not liquid leakage occurred. Furthermore, the liquid leakage rate ((number of samples with liquid leakage) / (total number of samples) × 100) was calculated for each of the medical caps of Example 1 and Comparative Example 1. The results are shown in Tables 1 and 2.

[0071] The evaluation criteria in Tables 1 and 2 are as follows: ○: No leakage △: Drop ×: Leaking

[0072] As can be seen from Tables 1 and 2, the leakage rate was 30% when the medical cap of Comparative Example 1 was used. In contrast, the leakage rate was 0% when the medical cap of Example 1 was used.

[0073] [Table 1]

[0074] [Table 2]

[0075] (Puncture load (static load) test) The medical caps obtained in Example 1 and Comparative Example 1 were sterilized in an autoclave at 106°C for 35 minutes. Next, each medical cap was attached to a test container containing 100cc of water and sealed using a sealing machine. After that, a resin needle (outer diameter approximately φ3.8mm) for an infusion set was pierced into the center of the elastic stopper of the medical cap, and a weight was hung from it. A bottle filled with 1000g of water was used as the weight. After piercing, the container was left for 1 hour, and the number of needles that fell was counted.

[0076] The number of needles punctured was then gradually increased up to 10, and the number of needles that fell out after being left for 1 hour was counted for each case. The results are shown in Tables 3 and 4.

[0077] As can be seen from Tables 3 and 4, the weight did not fall off in either the medical cap of Example 1 or Comparative Example 1, demonstrating good puncture needle retention properties.

[0078] [Table 3]

[0079] [Table 4] [Explanation of symbols]

[0080] 1 Outer frame 2 Elastic plug 10 Medical Caps 11 Upper frame 11a Main body 12 Lower frame 12a Main body 12b Pressing part 12c Flange 13 First tapered surface 14 Second tapered surface 17 Placement section 17a Projection 18 Annular frame 19 Gate Remains 21 Needle surface 21a Recess 22 Wetted surface 25 Step 26 Periphery 27 Annular groove 31 Common lower mold (common mold) 32 First upper mold (first mold) 34 Depression 35 Second upper mold (second mold) 35a Molten resin injection gate 35b Runner 35c sprue 36 Ring-shaped protrusion 37 Draft angle 37a First draft angle 37b Second draft angle

Claims

1. A medical cap comprising an elastic stopper and an outer frame body having at least an upper frame portion that supports a peripheral edge portion of the elastic stopper from an upper surface side and a lower frame portion that supports the peripheral edge portion of the elastic stopper from a lower surface side, The lower frame portion is a flange portion protruding outward from the outer frame body; a pressing portion that presses the lower surface side of the peripheral edge portion of the elastic plug, At least a part of the outer surface of the pressing portion is a curved surface or a horizontal surface, A medical cap in which a compressive stress is applied toward the center of the elastic stopper by pressing with the pressing portion, and the upper and lower surfaces of the elastic stopper are deformed into a convex or concave shape so that the elastic stopper is held inside the outer frame, thereby forming multiple gate marks on the curved or horizontal surface.

2. A medical cap comprising an elastic stopper and an outer frame body having at least an upper frame portion that supports a peripheral edge portion of the elastic stopper from an upper surface side and a lower frame portion that supports the peripheral edge portion of the elastic stopper from a lower surface side, The lower frame portion is a flange portion protruding outward from the outer frame body; a pressing portion that presses the lower surface side of the peripheral edge portion of the elastic plug, an outer surface of the pressing portion is provided with a second tapered surface that is continuous with the flange portion and a first tapered surface that is continuous with the second tapered surface; an inclination angle of the first tapered surface with respect to a horizontal plane being smaller than an inclination angle of the second tapered surface with respect to the horizontal plane; A medical cap in which a plurality of gate marks are formed on the first tapered surface by applying compressive stress toward the center of the elastic stopper through pressing by the pressing portion, whereby the upper and lower surfaces of the elastic stopper are deformed into a convex or concave shape and the elastic stopper is held inside the outer frame.

3. A method for manufacturing a medical cap comprising an elastic stopper and an outer frame comprising at least an upper frame portion supporting a peripheral edge portion of the elastic stopper from an upper surface side and a lower frame portion supporting the peripheral edge portion of the elastic stopper from a lower surface side, The medical cap is configured such that the lower frame portion has a flange portion that protrudes outward from the outer frame body and a pressing portion that presses the lower surface side of the peripheral edge portion of the elastic stopper, using a common mold and a first mold, molding an upper frame portion having an inner wall with a mounting portion on which the elastic stopper can be mounted; The elastic plug is placed inside the upper frame portion with its upper surface facing downward, a second mold having a ring-shaped protrusion having a diameter smaller than that of the lower surface of the elastic stopper and capable of forming a cavity for molding the lower frame portion when combined with the common mold, and pressing the peripheral portion of the lower surface of the elastic stopper with the ring-shaped protrusion to close the common mold; injecting molten resin through a plurality of molten resin injection gates of the second mold, and molding the lower frame portion so that a plurality of gate marks are formed on an outer surface of the pressing portion, thereby molding the outer frame body; At least a part of a molding surface of the second mold that molds the pressing portion of the lower frame portion is curved so that at least a part of the pressing portion is a curved surface, or is flat so that at least a part of the pressing portion is a horizontal surface, the plurality of molten resin injection gates are provided on the curved molding surface or the flat molding surface of the second mold at outer peripheral portions of the ring-shaped protrusion in proximity to the ring-shaped protrusion, The plurality of gate marks are A method for manufacturing a medical cap in which the lower frame portion is formed on the curved surface or horizontal surface of the pressing portion by applying compressive stress toward the center of the elastic stopper due to the pressing by the pressing portion, thereby molding the elastic stopper so that the upper and lower surfaces of the elastic stopper are held inside the outer frame body in a convex or concave deformed state.

4. A method for manufacturing a medical cap comprising an elastic stopper and an outer frame comprising at least an upper frame portion supporting a peripheral edge portion of the elastic stopper from an upper surface side and a lower frame portion supporting the peripheral edge portion of the elastic stopper from a lower surface side, The medical cap comprises: the lower frame portion has a flange portion that protrudes outward from the outer frame body and a pressing portion that presses the lower surface side of the peripheral edge portion of the elastic plug, an outer surface of the pressing portion is provided with a second tapered surface that is continuous with the flange portion and a first tapered surface that is continuous with the second tapered surface; an inclination angle of the first tapered surface with respect to a horizontal plane being smaller than an inclination angle of the second tapered surface with respect to the horizontal plane, using a common mold and a first mold, molding an upper frame portion having an inner wall with a mounting portion on which the elastic stopper can be mounted; The elastic plug is placed inside the upper frame portion with its upper surface facing downward, a second mold having a ring-shaped protrusion having a diameter smaller than that of the lower surface of the elastic stopper and capable of forming a cavity for molding the lower frame portion when combined with the common mold, and pressing the peripheral portion of the lower surface of the elastic stopper with the ring-shaped protrusion to close the common mold; injecting molten resin through a plurality of molten resin injection gates of the second mold, and molding the lower frame portion so that a plurality of gate marks are formed on an outer surface of the pressing portion, thereby molding the outer frame body; the second mold has a first draft angle for forming the first tapered surface and a second draft angle for forming the second tapered surface; the plurality of molten resin injection gates are provided on an outer peripheral edge portion of the ring-shaped protrusion in proximity to the ring-shaped protrusion at the first draft angle, The plurality of gate marks are A method for manufacturing a medical cap in which the lower frame portion applies compressive stress toward the center of the elastic stopper by pressing with the pressing portion, thereby forming the first tapered surface of the pressing portion by molding the elastic stopper so that the upper and lower surfaces of the elastic stopper are held inside the outer frame body in a convex or concave deformed state.

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