Medical cap and method for manufacturing the same

Abstract

The present invention provides a medical cap that prevents leakage during needle sticks, has excellent retention against needle dislodgement, and prevents the elastic stopper from falling off the outer frame, as well as a method for manufacturing the same. [Solution] The medical cap 1 of the present invention comprises an elastic plug body 20 and an outer frame body 10 having an annular body portion 11 and a support portion 12. The annular body portion 11 has an inner wall 11b that closely surrounds the side circumference 23 of the elastic plug body 20, an outer wall 11a that surrounds the inner wall 11b, and a slit portion 11d that longitudinally intersects the inner wall 11b. The inner wall 11b is a downward-sloping wall spaced apart from the outer wall 11a. The support portion 12 has an upper support portion 12a that supports the side circumference 23 of the elastic plug body 20 from the upper side, a lower support portion 12b that supports it from the lower side, and a connecting portion 12d that connects them. The connecting portion 12d has the slit portion 11d embedded in it, the lower support portion 12b is embedded between the inner wall 11b and the outer wall 11a, and the support portion 12 is welded to the elastic plug body 20 and the annular body portion 11.

Description

Technical Field

[0001] The present invention relates to a medical cap used for drug containers such as infusion containers, blood collection tubes, vial bottles, etc., and a method for manufacturing the same. In particular, in the medical field, the present invention relates to a medical cap that does not leak liquid during needle puncture and has excellent holding force against needle removal, and a method for manufacturing the same.

Background Art

[0002] For drug containers such as chemical solution bottles and infusion bottles for intravenous drip used in the medical field, in order to be able to take out the chemical solution with an injection needle, as the medical cap, a rubber stopper or a cap in which an elastic stopper (for example, rubber, elastomer resin, etc.) is accommodated inside an outer frame body is used. In the latter medical cap, the outer frame body is attached by welding or the like to the mouth portion of the drug container. And at the time of use, an injection needle provided with a extraction tube is pierced into the elastic stopper, the drug container is placed on the upper side, and the medical cap is placed on the lower side, so that the infusion in the container is taken out through the extraction tube. Further, such a medical cap is required to have airtightness in order to prevent leakage of chemical solutions or infusions and to prevent deterioration due to contact with air.

[0003] As the above-mentioned medical cap, for example, a cap including a substantially cylindrical stopper and an outer frame body that houses the stopper inside is disclosed (Patent Document 1). In this medical cap, the lower bottom portion of the stopper and the upper portion of the bottom surface holding portion of the outer frame body are welded to each other, and the side surface portion of the stopper and the inner wall of the side peripheral portion of the outer frame body are in contact with each other in a non-welded state. And according to Patent Document 1, it is said that it is possible to prevent the needle of the puncture needle punctured into the stopper from coming out and to ensure re-sealing property and airtightness.

[0004] Furthermore, Patent Document 2 discloses a medical cap comprising a stopper and an outer frame that houses the stopper, wherein the outer frame has at least an upper side circumferential portion and a lower leg portion that has a welded portion with the side circumferential portion. In addition, in this medical cap, the side circumferential portion of the stopper holds the stopper by contacting the side portion of the stopper from the side direction in a non-welded state at its inner wall, and the leg portion has a structure in which at least a part of its upper portion is welded to the peripheral edge of the liquid-contacting surface of the stopper. According to Patent Document 2, this makes it possible to improve resealability and prevent needle detachment.

[0005] However, in the medical caps described in these patent documents, the side portion of the stopper body is in contact with the inner wall of the outer frame body in a non-welded state. Therefore, when using a large-diameter needle, such as a spiked needle used to transfer drugs like anticancer agents from one container to another, there is a problem that the peripheral edge of the needle-piercing surface of the stopper body will detach from the outer frame body. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2001-130614 [Patent Document 2] Japanese Patent Publication No. 2001-212204 [Patent Document 3] Japanese Patent Publication No. 2001-212845 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a medical cap and a method for manufacturing the same that prevents liquid leakage when a needle is stuck, has excellent retention force against needle dislodgement, and prevents the elastic stopper from falling off the outer frame. [Means for solving the problem]

[0008] The medical cap according to the present invention, in order to solve the above problems, is a medical cap comprising an elastic plug and an outer frame that holds the elastic plug inside, wherein the outer frame has an annular portion and a support portion, the annular portion has an inner wall that surrounds the side circumference of the elastic plug in a tightly fitted state, an outer wall that surrounds the inner wall, and at least one slit portion that longitudinally intersects the inner wall, and the support portion has an upper support portion that supports the side circumference of the elastic plug from the upper side, and a lower support portion that supports the side circumference of the elastic plug from the lower side, and The device has an upper support portion and at least one connecting portion that connects the lower support portion, the inner wall is a downward-hanging wall that is connected to the inner surface of the outer wall at its upper end and whose wall surface is spaced apart from the outer wall, the lower support portion is embedded between the inner wall and the outer wall and presses the side circumference of the elastic plug body through the inner wall, the connecting portion embeds the slit portion, the elastic plug body is in close contact with the contact surface of the annular body portion, and the support portion is welded to the contact surface of the elastic plug body and the annular body portion.

[0009] In the above configuration, it is preferable that a notch is provided at the lower end of the inner wall.

[0010] Furthermore, in the above configuration, it is preferable that the lower surface side of the circumferential portion of the elastic plug body is provided with a male tapered portion that gradually decreases in diameter towards the lower surface of the elastic plug body.

[0011] Furthermore, in the above configuration, when the lower support portion is not embedded between the inner wall and the outer wall, it is preferable that the inner wall protrudes downward from the lower end surface of the outer wall.

[0012] Furthermore, in the above configuration, it is preferable that the inner wall surface is provided with a locking portion for locking the side periphery of the elastic plug body housed inside the inner wall.

[0013] The present invention provides a method for manufacturing a medical cap in order to solve the above problems, and is characterized by including: an annular body molding step of molding the annular body using a common mold and a first mold; a placement step of placing the elastic plug inside the annular body with its upper surface facing downward; and a support part molding step of molding the support part using the common mold and a second mold having a ring-shaped projection having a diameter smaller than the lower surface of the elastic plug, while pressing the peripheral edge of the lower surface of the elastic plug placed inside the annular body with the ring-shaped projection.

[0014] In the above configuration, it is preferable that the support molding step involves injecting molten resin for molding the support between the inner wall and the outer wall of the annular body to form the support.

[0015] Furthermore, in the above configuration, it is preferable that the support part molding process involves injecting the molten resin between the inner wall and the outer wall of the annular part at the central position of the inner wall to form the support part.

[0016] Furthermore, in a configuration in which a notch is provided at the lower end of the inner wall, it is preferable that the support molding process involves injecting molten resin for molding the support between the inner wall and the outer wall of the annular body at the location where the notch is provided to mold the support. [Effects of the Invention]

[0017] The medical cap of the present invention comprises an elastic plug body and an outer frame body that holds the elastic plug body inside, the outer frame body having an annular portion and a support portion. Furthermore, the annular portion comprises an inner wall that surrounds the side circumference of the elastic plug body in close contact, an outer wall that surrounds it at a distance from the inner wall, and at least one slit portion that crosses the inner wall longitudinally. The support portion has a structure comprising an upper support portion that supports the side circumference of the elastic plug body from the top side, a lower support portion that supports the side circumference from the bottom side, and at least one connecting portion that connects the upper support portion and the lower support portion and embeds the slit portion. The lower support portion is also embedded between the inner wall and the outer wall, so that the lower support portion presses against the side circumference of the elastic plug body via the inner wall. The support portion is welded to the elastic plug body and the annular portion at the contact surface. Therefore, according to the present invention, even when a large-diameter puncture needle, such as a spiked needle, is inserted into the elastic stopper, it is possible to prevent the elastic stopper from falling off the outer frame. Furthermore, leakage of liquid during needle insertion can be effectively prevented. Moreover, since the elastic stopper is only in close contact with the annular portion at the inner wall, it is held inside the outer frame without being constrained by the annular portion, compared to the support portion which is welded at the contact surface. Therefore, it prevents the needle from coming out when a puncture needle is inserted into the elastic stopper, and the resealing properties of the elastic stopper can be effectively maintained even after repeated needle insertion and removal. In other words, according to the present invention, it is possible to provide a medical cap and a method for manufacturing the same that prevents liquid leakage during needle insertion, has excellent holding power against needle removal, and prevents the elastic stopper from falling off the outer frame. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1(a) is a perspective view of a medical cap according to one embodiment of the present invention, viewed from the needle-piercing side, and Figure 1(b) is a perspective view of the medical cap viewed from the liquid-contacting side. [Figure 2]FIG. 2(a) is a plan view of a medical cap according to an embodiment of the present invention as viewed from the puncture surface side, FIG. 2(b) is a plan view as viewed from the liquid contact surface side, and FIG. 2(c) is a sectional view taken along line A-A' in the medical cap shown in FIG. 2(a). [Figure 3] FIG. 3(a) is a perspective view of an annular body part before being incorporated into a medical cap according to an embodiment of the present invention as viewed from the lower side, FIG. 3(b) is a plan view of the annular body part as viewed from the lower side, and FIG. 3(c) is a plan view as viewed from the upper side. [Figure 4] FIG. 4(a) is a sectional view taken along line B-B' in the annular body part shown in FIG. 3(c), FIG. 4(b) is a side view of the annular body part, and FIG. 4(c) is an enlarged sectional view of a main part of the annular body part. [Figure 5] FIG. 5(a) is a perspective view schematically showing an elastic plug body according to an embodiment of the present invention, FIG. 5(b) is a plan view of the elastic plug body as viewed from the puncture surface side, FIG. 5(c) is a plan view of the elastic plug body as viewed from the liquid contact surface side, and FIG. 5(d) is a side view of the elastic plug body. [Figure 6] FIG. 6 is a sectional view for explaining a manufacturing method of a medical cap according to an embodiment of the present invention. FIG. 6(a) shows a state where an annular body part is formed using a first upper mold and a common lower mold, FIG. 6(b) shows a state where an elastic plug body is placed on the annular body part, and FIG. 6(c) shows a second upper mold and a common lower mold on which the annular body part with the elastic plug body placed thereon is fixed. [Figure 7] FIG. 7 is an enlarged sectional view showing a main part of the common lower mold. [Figure 8] FIG. 8 is a sectional view for explaining a manufacturing method of a medical cap according to an embodiment of the present invention. FIG. 8(a) shows a state where the second upper mold and the common lower mold are closed, FIG. 8(b) shows a state where a support part is formed using the second upper mold and the common lower mold, and FIG. 8(c) shows a state where the medical cap is manufactured and the second upper mold and the common lower mold are opened. [Figure 9]FIG. 9(a) is a perspective view of another annular body part before being incorporated into the medical cap according to an embodiment of the present invention, viewed from the lower side, FIG. 9(b) is a plan view of the other annular body part when viewed in plan from the lower side, FIG. 9(c) is a cross-sectional view taken along the line C-C' in the other annular body part shown in FIG. 9(b), and FIG. 9(b) is a side view of the annular body part. [Figure 10] FIG. 10(a) is a perspective view of another annular body part before being incorporated into the medical cap according to an embodiment of the present invention, viewed from the lower side, and FIG. 10(b) is a perspective view of the other annular body part viewed from the upper side. [Figure 11] FIG. 11(a) is a perspective view of another annular body part before being incorporated into the medical cap according to an embodiment of the present invention, viewed from the lower side, and FIG. 11(b) is a perspective view of the other annular body part viewed from the upper side. [Figure 12] FIG. 12(a) is an enlarged cross-sectional view of a main part of an annular body part provided with an engaging part formed by an annular groove on the inner peripheral surface of an outer wall, FIG. 12(b) is an enlarged cross-sectional view of a main part of an annular body part provided with an engaging part formed by an annular protrusion on the outer peripheral surface of the outer wall, and FIG. 12(c) is an enlarged cross-sectional view of a main part of an annular body part provided with an engaging part formed by an annular groove on the outer peripheral surface of the outer wall. [Figure 13] FIG. 13(a) is a perspective view of another elastic plug body according to an embodiment of the present invention, viewed from the needle-piercing surface side, FIG. 13(b) is a perspective view of the other elastic plug body viewed from the liquid-contact surface side, and FIG. 13(c) is a side view of the other elastic plug body. [Figure 14] FIG. 14(a) is a perspective view schematically showing a port member provided with a medical cap according to another embodiment of the present invention, and FIG. 14(b) is a cross-sectional view of the port member. [Figure 15] A cross-sectional view schematically showing a medical cap according to another embodiment of the present invention. [Figure 16] FIG. 16(a) is a cross-sectional view schematically showing a medical cap according to another embodiment of the present invention, and FIG. 16(b) is a cross-sectional view schematically showing another second upper mold that enables molding of a lower support part provided with an engaging part. [Figure 17] A cross-sectional view schematically showing a medical cap according to Comparative Example 1. [Modes for carrying out the invention]

[0019] (Medical cap) The medical cap according to this embodiment will be described below based on the drawings. Note that in each figure, parts unnecessary for explanation have been omitted, and parts have been enlarged or reduced to facilitate explanation.

[0020] As shown in Figures 1 and 2, the medical cap 1 according to this embodiment comprises at least an outer frame 10 and an elastic stopper 20 held inside the outer frame 10. Figure 1(a) is a perspective view of the medical cap 1 according to one embodiment of the present invention as seen from the needle-piercing surface 21 side, and Figure 1(b) shows the medical cap 1 as seen from the liquid-contacting surface 22 side. Figure 2(a) is a plan view of the medical cap 1 as seen from the needle-piercing surface 21 side, Figure 2(b) is a plan view as seen from the liquid-contacting surface 22 side, and Figure 2(c) is a cross-sectional view of the medical cap 1 shown in Figure 2(a) along the line A-A'. In this specification, "needle-piercing surface" means the surface on which the medical cap 1 according to this embodiment is attached to a drug container and is pierced by a puncture needle when dispensing a drug solution, etc. Also, in this specification, "liquid-contacting surface" means the surface that comes into contact with the drug solution, etc. stored in the drug container.

[0021] The outer frame 10 comprises an annular body portion 11 with an overall cylindrical shape and a support portion 12 that supports the side circumference 23 of the elastic plug 20 from the needle piercing surface 21 side and the liquid contact surface 22 side. The annular body portion 11 and the support portion 12 are welded to each other at their contact surfaces, thereby forming an integrated structure that constitutes the outer frame 10. The annular body portion 11 is in close contact with the contact surface of the elastic plug 20 without welding. The support portion 12 is welded to the contact surface of the elastic plug 20. In this specification, "welding" means, as described later, that when the support portion 12 is molded by injection molding or the like, the heat of the molten resin injected melts the surfaces of the annular body portion 11 and the elastic plug 20 that are in contact with it, resulting in a state where the support portion 12 is joined to the annular body portion 11 and the elastic plug 20 at their contact surfaces after molding.

[0022] As shown in Figures 2(a), 2(c), 3(a) to 3(c), and 4(a) to 4(c), the annular body portion 11 comprises an outer wall 11a and an inner wall 11b. Figure 3(a) is a perspective view of the annular body portion 11 from below before it is incorporated as a component material of the medical cap 1, Figure 3(b) is a plan view of the annular body portion 11 from below, and Figure 3(c) is a plan view of the annular body portion 11 from above. Furthermore, Figure 4(a) is a cross-sectional view of the annular body portion 11 taken along the line B-B' shown in Figure 3(c), Figure 4(b) is a side view of the annular body portion 11, and Figure 4(c) is an enlarged cross-sectional view of the main part of the annular body portion 11.

[0023] The outer wall 11a is provided so as to surround the inner wall 11b. The inner wall 11b is connected to the inner surface of the outer wall 11a at its upper end via an inner wall connecting portion 11e. As shown in Figures 4(a) and 4(c), the connection position by the inner wall connecting portion 11e is at a position a distance below the upper end surface of the outer wall 11a. Furthermore, the inner wall 11b hangs down with its wall surface separated from the outer wall 11a, forming a downward-sloping wall. The annular body portion 11 houses the elastic plug 20 such that the inner wall 11b surrounds it. The inner surface of the inner wall 11b is in close contact with the side circumference 23 of the elastic plug 20 without welding, thereby holding the elastic plug 20 inside the outer frame 10 without being constrained by the annular body portion 11. Therefore, it prevents the needle from coming out when the puncture needle is inserted into the elastic plug 20, and also ensures good resealability after the puncture needle is inserted and removed again.

[0024] Furthermore, the outer wall 11a and the inner wall 11b are spaced apart, except for the connecting portion (i.e., the inner wall connecting portion 11e). The spacing between the outer wall 11a and the inner wall 11b may be narrower towards the bottom of the outer wall 11a and the inner wall 11b, or they may be equidistant, before the annular body portion 11 is incorporated as a component of the medical cap 1. In the former case, it facilitates the flow of molten resin for molding the support portion 12 between the outer wall 11a and the inner wall 11b.

[0025] An engaging portion 11f is provided on the inner circumferential surface of the outer wall 11a, above the inner wall connecting portion 11e (i.e., in the direction opposite to the direction in which the inner wall 11b hangs down) (Figures 4(a) and 4(c)). The engaging portion 11f consists of a protruding portion that is provided in an annular shape in the circumferential direction of the annular body portion 11. The engaging portion 11f also has the function of engaging the molded annular body portion 11 with the mold and temporarily fixing it in place when the mold is opened after the annular body portion 11 has been molded. The vertical cross-sectional shape of the engaging portion 11f is not particularly limited as long as it is able to engage with the mold and does not result in excessive mold release failure when the annular body portion 11 is released from the mold. Specifically, the vertical cross-sectional shape of the engaging portion 11f may be triangular as shown in Figure 4(c), or it may be semicircular, etc. Furthermore, it is preferable that the vertical cross-sectional shape of the engaging portion 11f is substantially uniform over the entire circumference of the inner circumferential surface of the outer wall 11a. Furthermore, the "vertical cross-sectional shape" of the engaging portion 11f refers to the cross-sectional shape obtained by cutting with a plane that passes through the center point of the annular body portion 11 and includes the vertical direction of the outer wall 11a.

[0026] As shown in Figure 2(b), the lower support portion 12b of the support portion 12 is embedded between the outer wall 11a and the inner wall 11b (details of the support portion 12 will be described later). When the lower support portion 12b is embedded, the inner wall 11b is deformed in a direction that reduces its diameter. As a result, the lower support portion 12b can press against the side circumference 23 of the elastic plug body 20 housed inside the inner wall 11b via the inner wall 11b, and as a result the elastic plug body 20 is held inside the outer frame 10 in a state in which the wetted surface 22 side is deformed into a concave shape. By holding the elastic plug body 20 in a deformed state, it is possible to improve the holding force against needle removal, the restoring force, and the resealability after needle removal.

[0027] Before the annular portion 11 is incorporated as a component of the medical cap 1, the inner wall 11b protrudes downward from the lower end surface of the outer wall 11a, as shown in Figure 4(b). By adopting this configuration, the inner wall 11b can be pressed so as to sufficiently cover the side circumference 23 of the elastic plug 20. However, the present invention is not limited to this embodiment. For example, the lower end surface of the inner wall 11b may be at the same height as the lower end surface of the outer wall 11a, or the lower end surface of the outer wall 11a may be lower than the lower end surface of the inner wall 11b.

[0028] The inner wall 11b is provided with four slits 11d. The slits 11d sectionalize the elastic plug body 20 vertically between the needle-piercing surface 21 and the liquid-contacting surface 22, and as a result, the inner wall 11b is composed of four inner walls, from the first inner wall 11b1 to the fourth inner wall 11b4. The four slits 11d are also provided at equal intervals from each other. Furthermore, in a plan view, each slit 11d virtually forms the same arc shape with respect to the center point O of the annular body 11 (see Figure 3(c)). The slits 11d with this configuration function as a flow path for the molten resin, which is the constituent material of the support part 12, when the support part 12 is molded (details will be described later). The slits 11d also enable the embedding of the connecting part 12d that connects the upper support part 12a and the lower support part 12b of the support part 12, which will be described later.

[0029] The width of the slit portion 11d (or the length of the virtual arc in a plan view) can be appropriately set according to the number of slit portions 11d and the width (or length) of the connecting portion 12d in a plan view. Furthermore, as described above, since each slit portion 11d virtually forms an arc shape in its plan view, the central angle θ1 at the center point O of the annular body portion 11 can also be set according to the number of slit portions 11d and the width of the connecting portion 12d. The central angle θ1 is usually 45° or less, preferably in the range of 5° or more and 45° or less, and more preferably in the range of 10° or more and 40° or less. By setting the central angle θ1 to 45° or less, the width of the inner wall 11b (or the length of the arc in a plan view) is prevented from becoming excessively narrow. This prevents the contact surface area between the inner wall 11b and the side circumference 23 of the elastic plug 20 from becoming too small, thereby preventing a decrease in the pressure of the inner wall 11b on the elastic plug 20. As a result, it is possible to hold the elastic plug 20 in a sufficiently deformed state, and good retention force against needle removal, restorative force, and resealability after needle removal can be maintained. Furthermore, if the central angle θ1 is 5° or more, a good flow path for the molten resin, which is the constituent material of the support part 12, can be secured. As a result, it becomes possible to fill with a sufficient amount of molten resin to form the upper support part 12a, and the upper support part 12a can be molded well. In addition, it prevents the connecting part 12d that connects the upper support part 12a and the lower support part 12b from becoming excessively small, and good connection between the upper support part 12a and the lower support part 12b can be maintained. Furthermore, the central angle θ1 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, or 45°, or it may be within the range of any two of the values ​​exemplified here.

[0030] Furthermore, the number of slit portions 11d in the present invention is not particularly limited, and may be, for example, 1, 2, 3, 4, 6, or 8. When multiple slit portions 11d are provided, it is preferable that each slit portion 11d be provided at equal intervals from one another.

[0031] Furthermore, as shown in Figures 3(a) and 4(a), notches 11c are provided in the center of the lower ends of the first inner wall 11b1 to the fourth inner wall 11b4 that constitute the inner wall 11b. The notches 11c are rectangular in shape, which prevents the molten resin injection gate from coming into contact with the first inner wall 11b1 to the fourth inner wall 11b4 when molding the support part 12. The notches 11c can also function as a flow path for the molten resin that is the constituent material of the support part 12 (details will be described later). The size of the notches 11c can be appropriately set according to the position and size of the molten resin injection gate, the flow rate of the molten resin, etc. Also, the shape of the notches 11c is not limited to rectangular. For example, they may be trapezoidal, triangular, etc.

[0032] Furthermore, the first inner wall 11b1 to the fourth inner wall 11b4 are each formed in an arc shape with respect to the center point O of the annular body portion 11. The central angle θ2 of the first inner wall 11b1 to the fourth inner wall 11b4 can be appropriately set according to the number of slit portions 11d and the value of the central angle θ1 of the slit portions 11d. The central angle θ2 is usually 115° or less, preferably in the range of 18° or more and 115° or less, more preferably in the range of 45° or more and 115° or less, and even more preferably in the range of 50° or more and 110° or less. By setting the central angle θ2 to 115° or less, the width of the slit portion 11d (or the length of the virtual arc in a plan view) is prevented from becoming excessively narrow. This ensures a good flow path for the molten resin, which is the constituent material of the support portion 12. As a result, a sufficient amount of molten resin can be filled to form the upper support portion 12a, and the upper support portion 12a can be molded well. Furthermore, this prevents the connecting portion 12d that connects the upper support portion 12a and the lower support portion 12b from becoming excessively small, thereby maintaining a good connection between the upper support portion 12a and the lower support portion 12b. Additionally, if the central angle θ2 is 20° or greater, it suppresses the width of the inner wall 11b (or the length of the arc in plan view) from becoming excessively narrow. This prevents the contact surface area between the inner wall 11b and the circumferential portion 23 of the elastic plug 20 from becoming too small, thus preventing a decrease in the pressure of the inner wall 11b on the elastic plug 20. As a result, it enables the elastic plug 20 to be held in a sufficiently deformed state, maintaining good holding force against needle removal, restoring force, and resealability after needle removal. Furthermore, the central angle θ2 can be 18, 20, 23, 30, 34, 38, 40, 45, 49, 50, 55, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 75, 79, 80, 85, 90, 95, 98, 100, 105, 109, 110, or 115°, or it may be within the range of any two of the values ​​exemplified here.

[0033] The thickness of the outer wall 11a is not particularly limited as long as it is sufficient to maintain the mechanical strength of the outer frame 10. Furthermore, it is preferable that the thickness of the outer wall 11a be uniform. The thickness of the inner wall 11b is not particularly limited as long as it is within a range in which the pressure from the lower support portion 12b to the elastic plug 20 can be transmitted. Furthermore, the thickness of the inner wall 11b may be uniform, or it may be configured to become thinner towards the lower end surface.

[0034] Here, the thickness w1 of the outer wall 11a shown in Figure 4(c) is preferably equal to or greater than the thickness t of the inner wall connecting portion 11e that connects the inner wall 11b to the outer wall 11a. This prevents or suppresses the occurrence of sink marks in the outer wall 11a in the areas A to C enclosed by the dashed lines shown in Figure 4(c). Furthermore, the thickness w2 of the inner wall 11b is preferably substantially the same as or less than the thickness t of the inner wall connecting portion 11e. This prevents or suppresses the collapse of the inner wall 11b during the molding of the annular body portion 11.

[0035] As shown in Figures 1 and 2, the support portion 12 has an upper support portion 12a, a lower support portion 12b, and four connecting portions 12d.

[0036] As shown in Figures 2(a) and 2(c), the upper support portion 12a supports the side circumference 23 of the elastic plug body 20 from the needle puncture surface 21 side. Specifically, the upper support portion 12a is annular and supports the elastic plug body 20 by welding it to a stepped portion (details will be described later) provided on the needle puncture surface 21 side of the side circumference 23 of the elastic plug body 20. By welding the upper support portion 12a to the stepped portion of the elastic plug body 20, it is possible to prevent the elastic plug body 20 from detaching from the outer frame body 10 even when a large-diameter puncture needle, such as a spiked needle, is inserted into the needle puncture surface 21.

[0037] As shown in Figures 2(a) and 2(c), the lower support portion 12b supports the side circumference 23 of the elastic plug body 20 from the wetted surface 22 side. Specifically, the lower support portion 12b is annular and supports the elastic plug body 20 by welding it to a male tapered portion (details will be described later) provided on the wetted surface 22 side of the side circumference 23 of the elastic plug body 20. By welding the lower support portion 12b to the male tapered portion of the elastic plug body 20, it is possible to prevent the elastic plug body 20 from falling off the outer frame body 10, similar to the case of the upper support portion 12a. In addition, the lower support portion 12b is also embedded between the outer wall 11a and the inner wall 11b (hereinafter, the part of the lower support portion 12b that is embedded between the outer wall 11a and the inner wall 11b will be called the embedded portion 12c). The embedded portion 12c presses against the side circumference 23 of the elastic plug body 20 via the inner wall 11b of the annular portion 11. As a result, the elastic plug body 20 is held inside the outer frame 10 in a deformed state, with the needle-piercing surface 21 being convex and the liquid-contacting surface 22 being concave. The shape of the embedded portion 12c is not particularly limited and is determined as appropriate by the shape of the space between the outer wall 11a and the inner wall 11b, the amount of molten resin flowing into the space during the molding of the support portion 12, and the injection pressure.

[0038] Furthermore, in the lower support portion 12b, an annular wall 12f is provided around the periphery of the opening where the liquid-contacting surface 22 of the elastic stopper 20 is exposed (see Figures 1(b) and 2(c)). The annular wall 12f hangs down in the direction opposite to the needle-piercing surface 21. This annular wall 12f has the function of fitting and connecting with the mouth of the drug container when the medical cap 1 is attached to the drug container.

[0039] As shown in Figures 1(b) and 2(b), four gate marks 12e are provided on the peripheral edge of the outer surface of the lower support portion 12b at equal intervals from one another. Here, "gate marks" refer to the traces of the gate, which is the injection port for molten resin into the cavity of the mold, and have an uneven shape formed on the molded body (in this embodiment, the lower support portion 12b). When molding the support portion 12, the molten resin injection gate is positioned to correspond to the formation positions of the notches 11c provided in the first inner wall 11b1 to the fourth inner wall 11b4. Therefore, the gate marks 12e are formed to correspond to the formation positions of the notches 11c provided in the first inner wall 11b1 to the fourth inner wall 11b4. The gate marks 12e are approximately circular in shape in plan view. The shape and size of the gate marks 12e in plan view are determined according to the opening shape and area of ​​the molten resin injection gate, the type of runner, etc., and are not particularly limited.

[0040] As shown in Figure 2(a), the connecting portion 12d connects the upper support portion 12a and the lower support portion 12b. The connecting portion 12d is columnar and is provided to fill the four slit portions 11d provided in the inner wall 11b. Since the connecting portion 12d is welded to the contact surface with the side circumference 23 of the elastic plug body 20, it serves to prevent the elastic plug body 20 from falling off the outer frame body 10, similar to the case of the upper support portion 12a and the lower support portion 12b.

[0041] As the material constituting the outer frame 10 (annular body portion 11 and support 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 in medical applications such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and PET (polyethylene terephthalate) resin are preferred, but the present invention is not limited to these. Furthermore, since the annular body portion 11 and the support portion 12 are welded together to constitute the outer frame 10, it is preferable that the constituent materials used for each are the same material or compatible materials. In addition, any component such as a coloring agent may be added to either the annular body portion 11 or the support portion 12, or to both.

[0042] As shown in Figures 1(a) and 1(b), the elastic stopper body 20 is housed inside the outer frame body 10 with the needle-piercing surface 21 facing upwards and the liquid-contacting surface 22 facing downwards. The needle-piercing surface 21 is provided with a recess 21a that serves as a position indicator when piercing with a puncture needle. The recess 21a is circular in plan view, but the present invention is not limited to this embodiment. Furthermore, the number and size of the recesses 21a (or its diameter if the recess 21a is circular in plan view) are not particularly limited, and it is sufficient to provide at least one recess 21a.

[0043] Furthermore, as shown in Figure 2(c), the elastic stopper 20 is held inside the outer frame 10 with the needle-piercing surface 21 deformed into a convex shape and the liquid-contacting surface 22 deformed into a concave shape. The degree to which the needle-piercing surface 21 and the liquid-contacting surface 22 are deformed is not particularly limited. For example, the entire structure may be deformed into a convex or concave shape, or the central part may be deformed into a convex or concave shape. Alternatively, the elastic stopper 20 may be held in the outer frame 10 with the needle-piercing surface 21 deformed into a concave shape and the liquid-contacting surface 22 deformed into a convex shape. Or, both the needle-piercing surface 21 and the liquid-contacting surface 22 may be deformed into a convex shape.

[0044] The overall shape of the elastic plug 20 is not particularly limited, but in this embodiment, as shown in Figures 5(a) to 5(d), it is substantially cylindrical. A stepped portion 23b is provided on the needle-piercing surface 21 side of the circumferential portion 23. Since the stepped portion 23b engages with the upper support portion 12a of the support portion 12, it is possible to further prevent the elastic plug 20 from detaching from the outer frame 10 when, for example, removing a puncture needle that has been pierced into the elastic plug 20. Preferably, the entire surface of the stepped portion 23b is welded to the upper support portion 12a. If the needle-piercing surface 21 is at a higher position than the upper support portion 12a, and a part of the stepped portion 23b is exposed without being welded to the upper support portion 12a, when a puncture needle is pierced into the needle-piercing surface 21 of the elastic plug 20, the deformation of the elastic plug 20 at the needle-piercing position will be greater, and the contact area between the puncture needle and the elastic plug 20 will increase. As a result, the penetration resistance of the puncture needle increases, which is undesirable.

[0045] Furthermore, a male tapered portion 23a is provided on the side of the circumferential portion 23 that is in contact with the liquid surface 22, and the diameter gradually decreases as it approaches the liquid surface 22 of the elastic plug body 20. By providing the male tapered portion 23a, compared to the case where it is not provided, it is possible to prevent the circumferential portion 23 on the liquid surface 22 side of the elastic plug body 20 from being excessively heated and melted by the molten resin during the molding of the support portion 12 (details of the molding method of the support portion 12 will be described later). The inclination angle α of the tapered surface of the male tapered portion 23a with respect to the horizontal plane (see Figure 5(d)) should be set to an extent that prevents excessive heating and melting by the molten resin, depending on the molding conditions of the support portion 12. Figure 5(a) is a schematic perspective view of the elastic stopper 20, Figure 5(b) is a plan view of the elastic stopper 20 viewed from the needle-piercing surface 21 side, Figure 5(c) is a plan view of the elastic stopper 20 viewed from the liquid-contacting surface 22 side, and Figure 5(d) is a side view of the elastic stopper 20.

[0046] In the medical cap 1 according to this embodiment, the elastic plug 20 is housed inside the outer frame 10, pressed from the male tapered portion 23a side by the embedded portion 12c via the inner wall 11b. As a result, compressive stress (crimping force) acts on the elastic plug 20 toward its center, causing the needle-piercing surface 21 to deform into a convex shape and the liquid-contacting surface 22 to deform into a concave shape. The elastic plug 20 is not welded to the annular portion 11 that constitutes the outer frame 10. Here, the annular portion 11 is welded to the support portion 12 at the contact surface, so even when a large-diameter puncture needle, such as a spike needle, is inserted into the elastic plug 20, it is possible to prevent the elastic plug 20 from detaching from the support portion 12. As a result, leakage of liquid during needle-piercing can be effectively prevented. Furthermore, the elastic plug 20 is in close contact with the annular portion 11 without being welded to it at the contact surface. Therefore, it prevents the needle from coming out when the puncture needle is inserted into the elastic plug 20, and also allows the elastic plug 20 to exhibit good resealing properties even after the puncture needle has been inserted and removed again.

[0047] (Method of manufacturing medical caps) Next, the manufacturing method of the medical cap 1 according to this embodiment will be described with reference to Figures 6 to 8. Figure 6 is a cross-sectional view illustrating the manufacturing method of the medical cap 1, where Figure (a) shows the process of forming the annular body portion 11 using the first upper mold (first mold) 31 and the common lower mold (common mold) 32, Figure (b) shows the elastic plug 20 placed on the annular body portion 11, and Figure (c) shows the second upper mold (second mold) 33 and the common lower mold 32 to which the annular body portion 11 with the elastic plug 20 placed on it is fixed. Figure 7 is an enlarged cross-sectional view showing the main part of the common lower mold 32. Figure 8 is a cross-sectional view illustrating the manufacturing method of the medical cap 1. Figure (a) shows the second upper mold 33 and the common lower mold 32 in a closed state, Figure (b) shows the process of forming the support part 12 using the second upper mold 33 and the common lower mold 32, and Figure (c) shows the medical cap 1 after it has been manufactured and the second upper mold 33 and the common lower mold 32 have been opened. Note that in each figure, parts that are not necessary for the explanation have been omitted, and parts have been enlarged or reduced to facilitate explanation.

[0048] The manufacturing method for the medical cap 1 includes an annular body molding step for molding an annular body portion 11, a placement step for placing an elastic plug 20 on the molded annular body portion 11, and a support portion molding step for molding a support portion 12.

[0049] The annular body molding process is carried out by injection molding the annular body 11 using a first upper mold 31 and a common lower mold 32, as shown in Figure 6(a). The first upper mold 31 is a core (convex mold), and the common lower mold 32 is a cavity (concave mold). The first upper mold 31 and the common lower mold 32 are structured so that when both are closed, a cavity is formed in which the annular body 11 can be molded. The first upper mold 31 is also provided with a spool (not shown) through which molten resin injected from an injection molding machine flows, a runner 31a as a passage for guiding the molten resin from the spool into the cavity, and a molten resin injection gate 31b for injecting molten resin into the cavity. The molten resin injection gate 31b is positioned so that its position is at the lower end surface of the outer wall 11a of the annular body 11 to be molded. As shown in Figures 6(a) and 7, the common lower mold 32 is provided with an annular groove 32a on the inner circumferential surface of the outer wall 11a of the annular body portion 11 for forming the aforementioned engaging portion 11f. The groove 32a is provided in an annular shape on the inner wall surface of the common lower mold 32, corresponding to the position where the engaging portion 11f is formed above the inner wall connecting portion 11e on the inner circumferential surface of the outer wall 11a of the annular body portion 11. This makes it possible to form the engaging portion 11f, which consists of an annular projection, on the inner circumferential surface of the outer wall 11a.

[0050] In molding the annular body portion 11, the molten resin, which is the constituent material of the annular body portion 11, passes through a spool (not shown) and a runner 31a in the first upper mold 31 and is injected into the cavity through the molten resin injection gate 31b. The injection pressure is not particularly limited and can be set as appropriate. The injected molten resin is cooled in the cavity for a predetermined time. This forms the annular body portion 11. The cooling time is not particularly limited and can be set as appropriate. There may be multiple molten resin injection gates 31b. In this case, it is preferable that each molten resin injection gate 31b is provided at equal intervals from one another.

[0051] As shown in Figure 6(b), the placement process involves opening the first upper mold 31 and the common lower mold 32, and then placing the elastic plug 20 inside the annular body portion 11. Here, the engaging portion 11f provided on the inner circumferential surface of the outer wall 11a of the annular body portion 11 and the groove portion 32a provided on the inner surface of the common lower mold 32 are engaged. Therefore, when opening the first upper mold 31 and the common lower mold 32, the annular body portion 11 adheres tightly to the first upper mold 31, preventing mold release defects. As a result, a decrease in manufacturing efficiency can be prevented. Furthermore, the elastic plug 20 is placed so that the needle-piercing surface (upper surface) 21 faces downward. The manufacturing method of the elastic plug 20 is not particularly limited; for example, it can be manufactured by compression molding or injection molding, which involves crushing a thermoplastic elastomer.

[0052] The support part molding process is carried out by injection molding the support part 12 using a second upper mold 33 and a common lower mold 32, as shown in Figure 6(c). The second upper mold 33 is a core (convex mold). The second upper mold 33 and the common lower mold 32 are structured such that when both are closed, a cavity is formed into which the support part 12 can be molded. The second upper mold 33 is also provided with a spool (not shown) through which molten resin injected from an injection molding machine flows, a runner 33a as a passage for guiding the molten resin from the spool into the cavity, and four molten resin injection gates 33b for injecting molten resin into the cavity. The four molten resin injection gates 33b are positioned at equal intervals from each other and are arranged to correspond to the formation positions of the notches 11c provided on the first inner wall 11b1 to the fourth inner wall 11b4 of the annular body part 11. Furthermore, as shown in Figure 6(c), the second upper mold 33 is provided with a ring-shaped projection 33c for pressing against the peripheral edge of the wetted surface 22 of the elastic stopper 20. The ring-shaped projection 33c also has the function of preventing molten resin from flowing between the wetted surface 22 of the elastic stopper 20 and the inside of the ring-shaped projection 33c by bringing the ring-shaped projection 33c into contact with the peripheral edge of the wetted surface 22.

[0053] The outer diameter r of the ring-shaped projection 33c is set appropriately according to the shape and size of the support portion 12 to be molded, but it is preferable that it be smaller than the diameter of the wetted surface 22 of the elastic plug body 20. However, if the outer diameter r is too small, the lower support portion 12b of the support portion 12 will be molded to be larger than necessary, resulting in a smaller area through which a puncture needle can penetrate, which may reduce the convenience of needle insertion.

[0054] Furthermore, the height h of the ring-shaped projection 33c is not particularly limited and is set appropriately according to the size of the elastic plug 20 and the shape of the support part 12 to be molded. Usually, it is preferably in the range of 0.3 mm to 8 mm, and more preferably in the range of 0.8 mm to 6 mm. By setting the height h to 8 mm or less, it is possible to prevent difficulty in closing the mold between the second upper mold 33 and the common lower mold 32. On the other hand, by setting the height h to 0.3 mm or more, it is possible to prevent insufficient pressing on the elastic plug 20, which would prevent the generation of compressive stress toward the center of the elastic plug 20.

[0055] As shown in Figure 8(a), when the second upper mold 33 and the common lower mold 32 are closed, the ring-shaped projection 33c contacts and deforms the peripheral edge of the wetted surface 22 of the elastic stopper 20. This causes the wetted surface 22 to deform into a convex shape. In addition, by contacting the ring-shaped projection 33c with the peripheral edge of the wetted surface 22 of the elastic stopper 20, it prevents molten resin from flowing into the gap between the wetted surface 22 of the elastic stopper 20 and the second upper mold 33.

[0056] Next, as shown in Figure 8(b), molten resin, which is the material that will make up the support part 12, is injected into the cavity formed by closing the mold. The molten resin passes through the spool and runner 33a in the second upper mold 33 and is injected into the cavity from the molten resin injection gate 33b. Here, the molten resin injected into the cavity first flows between the outer wall 11a and the inner wall 11b of the annular body part 11, and then, after being guided by the inner wall 11b, it heads towards the slits 11d provided on both sides of the inner wall 11b. The molten resin that reaches the slits 11d then flows further toward the male tapered part 23a of the elastic plug 20. In addition, a portion of the molten resin injected between the outer wall 11a and the inner wall 11b also flows toward the male tapered part 23a of the elastic plug 20 from the notch 11c provided in the inner wall 11b. This enables the molding of the lower support portion 12b, which is welded to the male tapered portion 23a of the elastic plug body 20. Furthermore, since a space is formed between the slit portion 11d and the side circumference portion 23 of the elastic plug body 20, which is not in close contact with the inner wall 11b, some of the molten resin that reaches the slit portion 11d flows through this space as a flow path to the needle-piercing surface 21 side of the elastic plug body 20. This enables the molding of the upper support portion 12a, which is welded to the stepped portion 23b of the elastic plug body 20. In addition, the molten resin that fills this space forms a connecting portion 12d that connects the upper support portion 12a and the lower support portion 12b. The injected molten resin is cooled in the cavity for a predetermined time. The injection pressure is not particularly limited and can be set as appropriate. Similarly, the cooling time is not particularly limited and can be set as appropriate. After the mold is opened, the support portion 12 is formed as shown in Figure 8(c). Here, after the mold is opened, the wetted surface 22 of the elastic stopper body 20 becomes concave as a result of the release of pressure from the ring-shaped projection 33c.

[0057] As a result, an outer frame 10 is formed in which the annular body portion 11 and the support portion 12 are integrated, and a medical cap 1 according to this embodiment is obtained.

[0058] (Other matters) In the embodiments described above, the medical cap of the present invention was explained using as an example an annular body of the outer frame in which a notch is provided in the inner wall. However, the present invention is not limited to this embodiment. For example, as shown in Figures 9(a) to 9(c), the annular body 41 may have an inner wall 42 composed of a first inner wall 42a to a fourth inner wall 42d that does not have a notch. Figure 9(a) is a perspective view from below of another annular body before it is incorporated into a medical cap according to another embodiment of the present invention, Figure 9(b) is a plan view of the other annular body when viewed from below, Figure 9(c) is a cross-sectional view taken along the line C-C' in the other annular body shown in Figure 9(b), and Figure 9(b) is a side view of the annular body. In this case, the four molten resin injection gates for injecting molten resin into the cavity to injection mold the support portion 12 are arranged so that the molten resin can be injected between each of the first inner wall 42a to the fourth inner wall 42d and the outer wall 11a, at the central portion of each of the first inner wall 42a to the fourth inner wall 42d.

[0059] Furthermore, the annular portion of the outer frame may be one which has a locking portion on the inner surface of the inner wall for locking the side circumference of the elastic plug. Examples of the locking portion include the protruding portion 45 shown in Figures 10(a) and 10(b). Figure 10(a) is a perspective view from below of another annular portion before it is incorporated into a medical cap according to another embodiment of the present invention, and Figure 10(b) is a perspective view from above of the other annular portion. The protruding portions 45 shown in these figures each extend vertically through the central part of each wall surface from the first inner wall 44a to the fourth inner wall 44d and protrude from the wall surface. As a result, the annular portion 43 shown in Figures 10(a) and 10(b) can properly support the elastic plug 20 when it is placed inside the inner wall 44. Alternatively, the locking portion may be a projection 48 as shown in Figures 11(a) and 11(b). The projections 48 shown in these figures extend horizontally across the central portion of each wall surface from the first inner wall 47a to the fourth inner wall 47d, and protrude from the wall surface. As a result, even in the annular body portion 46 shown in Figures 11(a) and 11(b), the elastic plug 20 can be well supported when the elastic plug 20 is placed inside the inner wall 47.

[0060] Furthermore, in the above-described embodiment, the medical cap of the present invention was described using as an example an embodiment in which the rod-shaped portion is provided with an engaging portion consisting of a protruding portion of an annular part on the inner circumferential surface of the outer wall and above the inner wall connecting portion. However, the present invention is not limited to this embodiment. For example, the engaging portions 11g to 11i shown in Figures 12(a) to 12(c), respectively, may also be used. Figure 12(a) is an enlarged cross-sectional view of the main part of an annular body portion 11 having an engaging portion 11g consisting of an annular groove on the inner circumferential surface of the outer wall 11a, Figure 12(b) is an enlarged cross-sectional view of the main part of an annular body portion 11 having an engaging portion 11h consisting of an annular protruding portion on the outer circumferential surface of the outer wall 11a, and Figure 12(c) is an enlarged cross-sectional view of the main part of an annular body portion 11 having an engaging portion 11i consisting of an annular groove on the outer circumferential surface of the outer wall 11a.

[0061] The engaging portion 11g shown in Figure 12(a) is located on the inner circumferential surface of the outer wall 11a and is provided above the inner wall connecting portion 11e. The engaging portion 11g consists of an annular groove in the circumferential direction of the annular body portion 11. In this case, the common lower mold is provided with an annular projection on the inner circumferential surface of the outer wall 11a of the annular body portion 11 for forming the engaging portion 11g. The projection is provided in an annular shape on the inner wall surface of the common lower mold, corresponding to the position where the engaging portion 11g is formed on the inner circumferential surface of the outer wall 11a of the annular body portion 11 and above the inner wall connecting portion 11e. This makes it possible to form the engaging portion 11g, which consists of an annular groove, on the inner circumferential surface of the outer wall 11a.

[0062] The engaging portion 11h shown in Figure 12(b) is located on the outer circumferential surface of the outer wall 11a and is provided above the inner wall connecting portion 11e. The engaging portion 11h consists of an annular projection in the circumferential direction of the annular body portion 11. In this case, the common lower mold is provided with an annular groove for forming the engaging portion 11h on the outer circumferential surface of the outer wall 11a of the annular body portion 11. The groove is provided in an annular shape on the inner wall surface of the common lower mold, corresponding to the position where the engaging portion 11h is formed on the outer circumferential surface of the outer wall 11a of the annular body portion 11 and above the inner wall connecting portion 11e. This makes it possible to form the engaging portion 11h, consisting of an annular projection, on the outer circumferential surface of the outer wall 11a.

[0063] The engaging portion 11i shown in Figure 12(c) is located on the outer circumferential surface of the outer wall 11a and is provided above the inner wall connecting portion 11e. The engaging portion 11i consists of an annular groove in the circumferential direction of the annular body portion 11. In this case, the common lower mold is provided with an annular projection on the outer circumferential surface of the outer wall 11a of the annular body portion 11 for forming the engaging portion 11i. The projection is provided in an annular shape on the inner wall surface of the common lower mold, corresponding to the position where the engaging portion 11i is formed on the outer circumferential surface of the outer wall 11a of the annular body portion 11 and above the inner wall connecting portion 11e. This makes it possible to form the engaging portion 11i, which consists of an annular groove, on the outer circumferential surface of the outer wall 11a.

[0064] Furthermore, the vertical cross-sectional shape of the engaging portions 11g to 11i (the cross-sectional shape obtained by cutting with a plane that passes through the center point of the annular body portion 11 and includes the vertical direction of the outer wall 11a) is not particularly limited as long as it allows the lower support portion 12b to be temporarily fixed to the common lower mold and does not result in excessive mold release defects when releasing the medical cap 3 from the common lower mold. In addition, it is preferable that the vertical cross-sectional shape of the engaging portions 11g to 11i is substantially uniform over the entire circumference of the inner surface of the outer wall 11a.

[0065] Furthermore, in the embodiments described above, the medical cap of the present invention was explained using as an example an elastic plug body in which a male tapered portion is provided on the fluid-contacting surface side of the circumferential portion. However, the present invention is not limited to this embodiment. For example, as shown in Figures 13(a) to 13(c), a stepped portion 26 may be provided on the fluid-contacting surface 22 side of the circumferential portion 25. Figure 13(a) is a perspective view of the elastic plug body 24 as seen from the needle-insertion surface side, Figure 13(b) is a perspective view of the elastic plug body 24 as seen from the fluid-contacting surface side, and Figure 13(c) is a side view of the elastic plug body 24. By providing a stepped portion 26 on the fluid-contacting surface 22 side of the circumferential portion 25, it can be engaged with the lower support portion 12b of the support portion 12, thereby further preventing the elastic plug body 24 from detaching from the outer frame body 10 when a puncture needle is inserted into the elastic plug body 24.

[0066] Furthermore, the medical cap of the present invention can also be applied to ports used in infusion bags and the like. An example of an infusion bag is one that comprises a rectangular bag body (not shown) capable of containing contents such as infusion fluids, and a cylindrical port member that is inserted through and fixed to an opening provided in the center of one end of the bag body. For an infusion bag with such a configuration, the medical cap 2 of the present invention can be incorporated into its tip, for example, as shown in Figures 14(a) and 14(b) of the port member 51. Figure 14(a) is a schematic perspective view of a port member 51 equipped with the medical cap 2, and Figure 14(b) is a cross-sectional view of the port member 51.

[0067] The medical cap 2 differs from the medical cap 1 according to the previously described embodiment in that its inner wall 11b' is a downward-sloping wall whose upper end is joined to the upper end surface of the outer wall 11a'. The port member 51 has a hollow cylindrical body 52 and a housing portion 53 provided at the tip of the cylindrical body 52 and housing the medical cap 2. The housing portion 53 is provided in an annular shape so as to protrude outward from the cylindrical body 52 and is formed coaxially with the cylindrical body 52. ​​In the medical cap 2 housed in the housing portion 53, only the needle-piercing surface 21 of the elastic plug 20 is exposed to the outside. The outer frame 10' is housed inside the housing portion 53 and is not visible from the outside. The outer frame 10' is welded to the contact surface of the housing portion 53.

[0068] Furthermore, the present invention can also adopt the embodiments of the medical cap 3 shown in Figure 15 and the medical cap 4 shown in Figure 16(a). Figures 15 and 16(a) are schematic cross-sectional views of medical caps according to other embodiments of the present invention. The medical cap 3 shown in Figure 15 differs from the medical cap 1 according to the above-described embodiment in that the lower support portion 12b has a flange portion 12g instead of an annular wall 12f. The flange portion 12g protrudes outward from the lower support portion 12b, enabling connection to the opening of a drug container or the like. This makes it possible to attach the medical cap 3 to the opening of a drug container or the like. In addition, an annular groove portion 12i is provided at any position on the outer circumferential surface of the flange portion 12g, as shown in Figure 15. As a result, for example, by providing an annular projection on the second upper mold that allows for the formation of a groove 12i, the molded lower support portion 12b can be engaged with the second upper mold and temporarily fixed in place when the common lower mold and the second upper mold are opened after the lower support portion 12b has been molded. The vertical cross-sectional shape of the groove 12i (the cross-sectional shape obtained by cutting with a plane that passes through the center point of the support portion 12 and includes the vertical direction of the outer wall 11a) is not particularly limited as long as it allows the lower support portion 12b to be temporarily fixed to the second upper mold and does not result in excessive mold release defects when releasing the medical cap 3 from the second upper mold. Furthermore, it is preferable that the vertical cross-sectional shape of the groove 12i is substantially uniform around the entire circumference of the flange portion 12g.

[0069] The medical cap 4 shown in Figure 16(a) differs in that an engaging portion 12h is provided on the inner surface of the annular wall 12f of the lower support portion 12b. The engaging portion 12h consists of a protruding portion that is provided in an annular shape in the circumferential direction of the annular wall 12f. For a medical cap 4 having such a form, it is preferable to provide an annular groove on the outer surface of the opening of a drug container, etc., which is connected by inserting the cylindrical opening into the annular wall 12f, so that it can engage with the engaging portion 12h. This allows the medical cap 4 to be firmly connected to the opening of the drug container, etc. The vertical cross-sectional shape of the engaging portion 12h (the cross-sectional shape cut by a plane that passes through the center point of the support portion 12 and includes the vertical direction of the annular wall 12f) is not particularly limited as long as it is capable of engaging with the opening to the extent that the drug container, etc. does not detach. Furthermore, it is preferable that the vertical cross-sectional shape of the engaging portion 12h is substantially uniform over the entire circumference of the inner surface of the annular wall 12f.

[0070] The engaging portion 12h can be formed by using the second upper mold (second mold) 33' shown in Figure 16(b). Figure 16(b) is a schematic cross-sectional view of another second upper mold that enables the molding of the lower support portion 12b equipped with the engaging portion 12h. The second upper mold 33' shown in Figure 16(b) differs from the aforementioned second upper mold 33 in that it has an annular groove 33d on the outer circumferential surface of the ring-shaped projection 33c. In the molding of the lower support portion 12b, when the second upper mold 33 and the common lower mold 32 are opened, the engaging portion 12h and the groove 33d are engaged, so the medical cap 4 can adhere tightly to the common lower mold 32, preventing mold release defects. As a result, a decrease in manufacturing efficiency can be prevented. [Examples]

[0071] Preferred embodiments of this invention will be described in detail below. However, unless otherwise specified, the materials and proportions described in the embodiments are not intended to limit the scope of this invention to those materials alone.

[0072] (Example 1) In this embodiment, a medical cap 1 having the same structure as shown in Figures 1 and 2 was manufactured according to the method shown in Figures 6 and 7. High-density polyethylene was used as the material for the annular body portion 11 and the support portion 12 that constitute the outer frame 10. Thermoplastic elastomer resin was used as the material for the elastic stopper 20. An injection molding machine (product name: DC100 / 200, manufactured by Nissei Plastic Industrial Co., Ltd.) was used as the molding machine. Ten samples of the medical cap 1 according to this embodiment were produced. The central angle θ1 of the slit portion 11d (the central angle of the arc virtually formed in a plan view with respect to the center point O of the annular body portion 11) was set to 27°, and the central angle θ2 of the first inner wall 11b1 to the fourth inner wall 11b4 with respect to the center point O of the annular body portion 11 was set to 63°.

[0073] The molding conditions for the annular body portion 11 are as follows. Injection molding temperature: 240℃ Injection pressure: 4.0 MPa Ejection time: 3.5 seconds 1st upper mold temperature: 20℃ Common lower mold temperature: 25℃

[0074] The molding conditions for the support portion 12 are as follows. Injection molding temperature: 240℃ Injection pressure: 4.8 MPa Ejection time: 4.0 seconds Second upper mold temperature: 20℃ Common lower mold temperature: 25℃

[0075] (Comparative Example 1) In this comparative example, the medical cap 100 shown in Figure 17 was used. Figure 17 is a schematic cross-sectional view of the medical cap 100. The medical cap 100 shown in the figure comprises an elastic stopper 120 and an outer frame 110 that holds the elastic stopper 120 inside. An annular stepped portion 123b is provided on the needle-piercing surface 121 side of the side circumference 123 of the elastic stopper 120, and an annular stepped portion 123a is also provided on the liquid-contacting surface 122 side of the side circumference 123. The outer frame 110 comprises an annular portion 111 that supports the side circumference 123 of the elastic stopper 120 from the needle-piercing surface 121 side, and a support portion 112 that supports the side circumference 123 of the elastic stopper 120 from the liquid-contacting surface 122 side.

[0076] The annular portion 111 comprises an inner wall 111b that surrounds the side circumference 123 of the elastic plug 120 in a tightly fitted state, an outer wall 111a that surrounds the inner wall 111b, and an engaging portion 111c that engages with the stepped portion 123b of the elastic plug 120. The inner wall 111b is connected to the inner surface of the outer wall 111a at its upper end and is a downward-hanging wall with its wall surface separated from the outer wall 111a. The inner wall 111b does not have notches or slits like the medical cap 1 of Embodiment 1.

[0077] The support portion 112 supports the side circumference 123 of the elastic plug body 120 from the liquid contact surface 122 side. Furthermore, by embedding the support portion 112 between the inner wall 111b and the outer wall 111a, it presses against the side circumference 123 of the elastic plug body 120 via the inner wall 111b. Note that the support portion 112 does not have a connecting portion for embedding the slit portion, as in the medical cap 1 of Embodiment 1.

[0078] The elastic plug 120 is in close contact with the annular body portion 111 at their contact surfaces. The support portion 112 is welded to the elastic plug 120 and the annular body portion 111 at their contact surfaces.

[0079] Furthermore, high-density polyethylene was used as the material for the annular portion 111 and the support portion 112 that constitute the outer frame 110. Thermoplastic elastomer resin was used as the material for the elastic stopper 120. The number of medical cap samples used in this comparative example was 10.

[0080] (Sterilization) Medical cap 1 of Example 1 and medical cap 100 of Comparative Example 1 were each sterilized by autoclaving at 105°C for 25 minutes.

[0081] (Leverage test of the puncture needle) The medical cap 1 of Example 1 and the medical cap 100 of Comparative Example 1 (hereinafter sometimes referred to as "medical cap 1, etc.") were attached to a test pressure vessel after sterilization. The test pressure vessel used was one in which the opening with the medical cap 1, etc. attached could be fixed in either the up or down direction.

[0082] Next, the opening of the test pressure vessel, to which a medical cap 1 or the like was attached, was positioned downwards (i.e., the liquid-contacting surface of the elastic stopper faced upwards and the needle-piercing surface faced downwards), and a resin needle for an infusion set (outer diameter approximately φ5 mm, length approximately 26 mm) was inserted into the injection hole of the elastic stopper. After standing for 24 hours with the needle inserted, the needle was removed, and the system was visually observed for 2 minutes to see if any leakage occurred from the downward-facing medical cap or the like. If leakage was observed, the amount of leakage (g) was also measured.

[0083] Puncture tests were performed on all medical caps, and the leakage rate (%) was calculated for each ((number of samples with leakage) / (total number of samples) × 100). The results are shown in Tables 1 and 2. The evaluation criteria in Tables 1 and 2 were as follows. ○: No leakage △: Droplet present ×: Leakage present

[0084] [Table 1]

[0085] [Table 2]

[0086] As can be seen from Tables 1 and 2, the leakage rate was 100% when using medical cap 100 of Comparative Example 1. In contrast, the leakage rate was 0% for medical cap 1 of Example 1.

[0087] (Puncture test with a spiked needle) Ten medical caps 1 from Example 1 and ten medical caps 100 from Comparative Example 1 were prepared and fixed to a dedicated jig. The dedicated jig used was one that could fix the elastic stopper body in a state where the needle-piercing surface and the liquid-contacting surface were exposed.

[0088] Next, a resin spiked needle was inserted into the recess of the needle-piercing surface of an elastic stopper body such as a medical cap 1, which was fixed with a special jig. The spiked needle used had blade surfaces that intersect the direction of extension of the spiked needle and a sharply pointed tip, with an outer diameter of approximately 5.5 mm, a length of approximately 20 mm, and a blade surface angle of approximately 36°. The puncture test was performed by checking whether the entire blade surface of the spiked needle protruded from the wetted surface of the elastic stopper body and was visible. If the entire blade surface was visible, it was considered puncture possible, and if the entire blade surface was not visible, it was considered puncture impossible. The puncture rate (%) ((number of punctureable samples) / (total number of samples) × 100) was calculated for each case. The results are shown in Tables 3 and 4. The evaluation criteria in Tables 3 and 4 were as follows. ○: Puncture possible ×: Puncture not possible

[0089] [Table 3]

[0090] [Table 4]

[0091] As can be seen from Tables 3 and 4, the puncture success rate was 100% when using medical cap 1 of Example 1. In contrast, the puncture success rate was 0% when using medical cap 100 of Comparative Example 1. [Explanation of symbols]

[0092] 1, 1', 2, 3, 4... Medical cap, 10, 10'... Outer frame, 11, 41, 43, 46... Annular body, 11a... Outer wall, 11b... Inner wall, 11c... Notch, 11d... Slit, 11e... Connecting part, 11f, 11g, 11h, 11i... Engaging part, 12... Support part, 12a... Upper support part, 12b... Lower support part, 12c... Embedded part, 12d... Connecting part, 12e... Gate mark, 12f... Annular wall, 12g... Flange part, 12h... Engaging part, 12i... Groove, 20, 24... Elastic plug, 21... Needle puncture surface, 21a... Recess, 22... Fluid contact surface, 23, 25... Side circumference, 23a... Male tapered part, 23b... Stepped part, 26...Stepped section, 31...First upper mold (first mold), 31a, 33a...Runner, 31b...Molten resin injection gate, 32...Common lower mold (common mold), 32a...Groove section, 33...Second upper mold (second mold), 33b...Molten resin injection gate, 33c...Ring-shaped projection, 33d...Groove section, 42, 44, 47...Inner wall, 42a, 44a, 47a...First inner wall, 42b, 44b, 47b...Second inner wall, 42c, 44c, 47c...Third inner wall, 42d, 44d, 47d...Fourth inner wall, 45...Protruding section (locking section), 48...Protrusion (locking section), 51...Port member, 52...Cylindrical body, 53...Housing section, θ1, θ2...Central angle

Claims

1. A medical cap comprising an elastic stopper and an outer frame that holds the elastic stopper inside, The aforementioned outer frame has an annular portion and a support portion. The aforementioned annular portion is, The inner wall surrounding the side circumference of the elastic plug body in a tightly fitted state, The outer wall surrounding the aforementioned inner wall, The inner wall has at least one slit portion that crosses it longitudinally, The aforementioned support portion is An upper support portion that supports the side circumference of the elastic plug body from the upper side, A lower support portion that supports the side circumference of the elastic plug body from the lower side, It has at least one connecting portion that connects the upper support portion and the lower support portion, The aforementioned inner wall is a downward-hanging wall that is connected to the inner surface of the outer wall at its upper end and whose wall surface is spaced apart from the outer wall. The lower support portion is embedded between the inner wall and the outer wall, thereby pressing the side circumference of the elastic plug body through the inner wall. The aforementioned connecting portion embeds the aforementioned slit portion, A medical cap in which the elastic plug is in close contact with the contact surface of the annular body, and the support portion is welded to the contact surface of the elastic plug and the annular body.

2. The medical cap according to claim 1, wherein a notch is provided at the lower end of the inner wall.

3. The medical cap according to claim 1, wherein the lower surface side of the circumferential portion of the elastic plug is provided with a male tapered portion that gradually decreases in diameter towards the lower surface of the elastic plug.

4. The medical cap according to claim 1, wherein, when the lower support portion is not embedded between the inner wall and the outer wall, the inner wall protrudes downward from the lower end surface of the outer wall.

5. The medical cap according to claim 1, wherein the inner wall surface is provided with a locking portion for locking the side circumference of the elastic plug body housed inside the inner wall.

6. A method for manufacturing a medical cap according to any one of claims 1 to 5, An annular body molding step in which the annular body portion is formed using a common mold and a first mold, The process of placing the elastic plug inside the annular body portion with its upper surface facing downwards, A method for manufacturing a medical cap, comprising a support molding step of forming the support portion using the common mold and a second mold having a ring-shaped projection having a diameter smaller than the lower surface of the elastic plug, while pressing the peripheral edge of the lower surface of the elastic plug, which is placed inside the annular portion, with the ring-shaped projection.

7. The method for manufacturing a medical cap according to claim 6, wherein the support part molding step involves injecting molten resin for molding the support part between the inner wall and the outer wall of the annular body to mold the support part.

8. The medical cap according to claim 7, wherein the support molding step involves injecting the molten resin between the inner wall and the outer wall of the annular portion at the central position of the inner wall to form the support portion.

9. The method for manufacturing a medical cap according to claim 6, as dependent on claim 2, wherein the support molding step involves injecting molten resin for molding the support between the inner wall and the outer wall of the annular body at the position where the notch is provided to mold the support.

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