JP4511575B2 - Manufacturing method of medical cap - Google Patents

Description

The present invention is an infusion container, a method of manufacturing a medical cap such as blood collection tubes. In particular, a method of manufacturing a medical cap having a needle stick can plug body in medical.

  For medical solution bottles used in the medical field and infusion bottles used for infusions, rubber caps or rubber or elastomer for needle pointing on the inner side of the outer frame body are used as caps so that the chemicals can be taken out with a needle. What provided the plug body which consists of resin is used. This outer frame is attached to the infusion container by a method such as welding. In use, the infusion solution in the container is taken out by inserting a needle into the stopper and lowering the cap. Therefore, such a medical cap is required to have hermetic properties in order to prevent leakage of chemicals and infusions and to prevent deterioration due to contact with air.

  For example, in the structure of the medical cap, the liquid contact surface of the plug body and the upper portion of the bottom surface holding portion of the outer frame body are fused, and the side wall of the plug body and the inner wall of the side periphery of the outer frame body Has been proposed to provide a medical cap that is improved in rubber characteristics and excellent in resealability by being brought into contact in a non-fused state (see Patent Document 1 below).

  However, in the case of a conventional medical cap, the close contact between the plug body and the outer frame body may not be sufficient. In such a medical cap, the position of the plug body and the outer frame body shifts during needle sticking, and a gap is created between them, or the second needle is stuck for that purpose, or needle sticking is performed again. There is a problem that it becomes difficult.

JP-A-2005-118185

The present invention has been made in view of the above-mentioned problems, and the object thereof is excellent in adhesiveness between the elastic plug body and the outer frame body holding the peripheral edge portion thereof by the inner wall, and the elastic plug body and the outer frame body by needle stick. no positional deviation of is to provide a method for producing superior medical cap to ensure tightness.

The present inventors have, to solve the above conventional problems, and studied the manufacturing method of a medical cap. As a result, the inventors have found that the object can be achieved by adopting the following configuration, and have completed the present invention.

In order to solve the above-described problems, the medical cap manufacturing method according to the present invention includes an elastic plug body, a lower frame portion that holds the peripheral edge portion of the elastic plug body from the lower surface side and the inner wall from the upper surface side. A method for manufacturing a medical cap having an outer frame body having an upper frame portion to hold, wherein the elastic plug body can be mounted using a first upper mold and a common lower mold A lower frame portion having an inner wall is molded, and the elastic plug body is placed on the placement portion of the lower frame portion with its upper surface facing upward, and the diameter is smaller than the diameter of the elastic plug body. A second upper die that has a projection portion and has a molding cavity for forming the upper frame portion when combined with the common lower die, and the projection portion is the elastic plug body. Close the common lower mold so that the center part of the mold is pushed down and push the molten resin into the cavity. And molding the upper frame portion, and forming the outer frame body.

  In the manufacturing method of the present invention, after forming the lower frame portion that holds the peripheral edge portion of the elastic plug body from the lower surface side by the inner wall, the upper frame portion that is held from the upper surface side by the inner wall is formed to form the outer frame body It is a method to do. The lower frame portion is formed using a first upper mold and a common lower mold. At this time, a mounting portion on which the elastic plug body can be mounted is also formed on the inner wall of the lower frame portion.

  Next, the elastic plug body is placed on the placement portion of the lower frame portion so that the upper surface thereof faces upward, and the upper frame portion is molded using the second upper mold and the common lower mold. The second upper mold includes a protrusion capable of pressing the central part of the elastic plug when combined with the common lower mold. At this time, the lower peripheral portion of the elastic plug is supported by the mounting portion described above, but there is nothing to support this in the central portion. For this reason, the central portion pressed by the protrusion is pushed downward. In such a state, the molten resin is injected into a cavity formed between the second upper mold and the common lower mold to mold the upper frame portion.

  The upper frame portion formed by the above method has a structure fused at the contact surface with the elastic plug. Thereby, for example, when needle sticking is performed from the upper surface side, it is possible to prevent a gap from being generated due to the displacement of the elastic plug body and the upper frame portion, and as a result, it is possible to ensure the sealing property of the chemical solution. Further, since the upper frame portion is molded in a state where the elastic plug is pressed downward, the central portion on the upper surface side of the elastic plug body swells upward after the upper frame portion is molded. Can be suppressed.

  In the said method, it is preferable to use what is comprised including a thermoplastic elastomer as said elastic plug. Thereby, a restoring force improves and it can provide the medical cap excellent in the needle holding force during infusion treatment and the resealability after needle removal.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts that are not necessary for the description are omitted, and there are parts that are illustrated in an enlarged or reduced manner for ease of explanation. FIG. 1 is a cross-sectional view for explaining a method for manufacturing a medical cap according to the present embodiment. FIG. 2 is a cross-sectional view showing a state of injection molding of the upper frame portion in the manufacturing method.

  As shown in FIG. 1A, the lower frame portion is injection molded using the first upper mold 13 and the common lower mold 11. In the present embodiment, the first upper mold 13 is a fixed mold, and the common lower mold 11 is a movable mold. The first upper mold 13 and the common lower mold 11 have a structure in which a cavity capable of forming a cylindrical lower frame portion is formed when the mold is closed.

  The molten resin 12 obtained by melting the resin as the constituent material of the lower frame portion passes through the sprue and runner in the first upper mold 13 and is injected into the cavity. The injection pressure is not particularly limited, and can be set as necessary. The injected molten resin 12 is cooled for a predetermined time. After the mold opening, as shown in FIG. 1B, the lower frame portion 15 is formed. On the inner wall of the lower frame portion 15, a mounting portion 14 for mounting an elastic plug body to be described later is provided.

  Next, as shown in FIGS. 1 (c) to 1 (e), the elastic stopper 17 is placed on the mounting portion 14 of the lower frame portion 15 so that the needle piercing surface (upper surface) 18 faces upward. Place and perform injection molding of the upper frame. Only the peripheral edge portion 17 a of the elastic plug body 17 is supported by the mounting portion 14 from below. Moreover, the diameter of the elastic plug body 17 is not specifically limited, Usually, it sets within the range of 12-30 mm. The diameter of the elastic plug 17 is preferably set to be smaller by about 0.1 mm to 0.5 mm than the inner diameter R1 at the opening of the lower frame portion 15. Thereby, the ease of insertion of the elastic plug 17 into the lower frame portion 15 is ensured. Furthermore, the thickness of the elastic plug 17 is not particularly limited, and is usually set within a range of 3 to 10 mm.

  Here, the details of the injection molding of the upper frame part are shown in FIGS. The second upper mold 16 and the common lower mold 11 are used for molding the upper frame portion. The second upper mold 16 and the common lower mold 11 have a structure in which a cavity capable of molding the upper frame portion is formed when the mold is closed. Further, since the central portion of the elastic plug 17 is not supported by the lower frame portion 15 when the mold is closed, it is pressed by a protrusion described later and pushed downward (FIG. 2). (See (b)). In addition, as the elastic plug body 17, one having a flat needle stick surface 18 and a stepped portion 17 b for preventing dropout only on the liquid contact surface 20 is used. However, the elastic plug body of the present invention is not limited to the shape. Other aspects will be described in detail later.

The second upper mold 16 is provided with a caulking insert 19, and the insert 19 includes a columnar protrusion 22 a and a step 22 b. The diameter r of the protrusion 22a is not particularly limited as long as it is smaller than the diameter of the elastic plug body 17, and is appropriately set according to the shape and size of the outer frame body to be molded. Usually, it is preferably within a range of 10.5 to 29 mm, and more preferably within a range of 11 to 28 mm. The inner diameter R ₂ exceeds 80% of the diameter of the elastic plug member 17, there is a case where the lower frame portion 15 at the time of mold clamping is unlikely to hold the elastic stopper 17. Meanwhile, if the inner diameter R ₂ is less than 45% of the diameter of the elastic plug member 17, deformation of the elastic stopper 17 at the time of mold clamping is locally, generation of compressive stress towards the center of the elastic stopper 17 It may not be seen.

  Further, the height h of the protrusion 22a is not particularly limited, and is appropriately set according to the size of the elastic plug 17 and the shape of the outer frame to be molded. Usually, it is preferably within a range of 1 to 5 mm, and more preferably within a range of 1.5 to 2.5 mm. If the height h exceeds 5 mm, it may be difficult to close the mold between the second upper mold 16 and the common lower mold 11. On the other hand, when the height h is less than 1 mm, it is insufficient to push down the central portion of the elastic plug body 17 downward, and there is a case where the generation of compressive stress toward the center of the elastic plug body 17 is not observed. .

  In addition, as a shape of a projection part, this invention is not limited to the said cylindrical projection part 22a. For example, various protrusions shown in FIGS. 3A to 3E can be employed. That is, a concave-shaped projection 23 having a depressed central portion (FIG. 5A), a convex-shaped projection 24 having a curved central portion with a predetermined curvature (FIG. 5B), a ring shape Projection part 25 (FIG. (C)), two-stage projection part (FIG. (D)), and cylindrical projection part (FIG. (E)) chamfered so that the corners are curved. It can be illustrated.

  Subsequently, as shown in FIG. 2B, the second upper mold 16 and the common lower mold 11 are closed. At this time, the central portion of the needle plug surface 18 of the elastic plug 17 is pressed by the protrusion 22a, and the liquid contact surface (lower surface) 20 is pressed downward. Further, a part of the peripheral edge portion of the needle piercing surface 18 of the elastic plug 17 is in contact with the stepped portion 22b.

  Next, a molten resin 31 in which a resin as a constituent material of the upper frame portion is melted is injected into the cavity 28 formed by mold closing. The injection pressure is not particularly limited, and can be set as necessary. The injected molten resin 31 is cooled for a predetermined time. After the mold opening, as shown in FIG. 2C, the upper frame portion 32 is formed. The contact portion between the elastic plug 17 and the upper frame portion 32 is in a fused state.

  As described above, the outer frame body 27 in which the upper frame portion 32 and the lower frame portion 15 are integrated is formed, and the medical cap 30 according to the present embodiment is obtained (FIGS. 1 (e) and 1 (f). )reference).

  In the medical cap 30 obtained by the manufacturing method, the elastic plug body 17 is compressed by the upper frame portion 32 toward the direction indicated by the arrow in FIG. 2C, that is, below the central portion of the elastic plug body 17. Stress (caulking force) is working. Due to the action of the compressive stress, the restoring force of the elastic plug body 17 itself acts in the direction of the side peripheral portion of the elastic plug body 17 and attempts to expand, so that the sealing performance with the lower frame section 15 is improved. As a result, the holding force and the restoring force against needle removal are improved, and the resealability after needle removal can be improved.

  Moreover, it can suppress that the center part of the needle stab surface 18 in the elastic plug body 17 bulges upwards by the effect | action of compression pressing force. More specifically, the height of the central portion of the elastic plug body 17 can be suppressed to 1.5 mm or less with reference to the peripheral edge portion. Thereby, when the peel film 29 for sealing the elastic plug body is attached to the upper frame portion 32, the peel film 29 can be prevented from coming into contact with the elastic plug body 17. Further, since the gap between the elastic plug 17 and the peel film 29 can be reduced and the volume of the air sealed by the peel film 29 can be reduced, for example, the peel film 29 due to the volume change of the sealed air during sterilization. Can be prevented from being deformed. Further, as a result of preventing the elastic stopper body 17 from bulging on the needle piercing surface 18, the step difference between the affixing portion 26a and the central portion in the upper frame portion 32 can be suppressed to 2 mm or less. The needle can be inserted without being hindered by this, and workability is improved.

  The contact portion between the elastic plug 17 and the lower frame portion 15 is in a non-fused state. Thereby, needle omission and liquid leakage during use can be prevented. That is, the side surface portion of the elastic plug body is not fixed to the lower frame portion 15 and is in a free state, so that it is possible to absorb the force that the elastic plug body 17 is pushed outward when a needle is stabbed. At this time, a force that holds the needle through the elastic plug 17 from the lower frame portion 15 is generated in the pierced needle as a reaction, so that needle removal can be prevented. Further, when the needle is pulled out, the elastic plug body 17 receives a force pushed inward from the lower frame portion 15, so that the hole generated by the needle can be closed and the resealability can be improved. The liquid contact surface 20 of the elastic plug body 17 is convex toward the lower side of the lower frame portion (see FIG. 2C). The distance s between the top of the liquid contact surface 20 that is convex and the surface including the stepped surface of the stepped portion 17b is preferably 0.1 mm to 3 mm, and preferably 0.1 mm to 2.5 mm. It is more preferable.

  In addition, as a material used for the lower frame part 15 and the upper frame part 32 which comprise the said outer frame body 27, the safety | security for medical use is sufficient among synthetic resins. Of these, a thermoplastic resin is generally used. Specifically, resins conventionally used for medical use such as polyethylene, polypropylene, and PET (polyethylene terephthalate) resin are preferable, but are not limited thereto. Since the lower frame portion 15 and the upper frame portion 32 are fused together to form the outer frame body 27, the components used are preferably the same component or compatible components. Moreover, you may add arbitrary components, such as a coloring agent, to one or both of the lower frame part 15 or the upper frame part 32. FIG.

  Examples of the material used for the elastic plug body 17 include rubber and thermoplastic elastomer. The rubber is not particularly limited, and examples thereof include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, and isoprene-isobutylene rubber. Moreover, it does not specifically limit as a thermoplastic elastomer, For example, an olefin type, a styrene type, a polyurethane type, a polyester type, a polyvinyl chloride type, a polybutadiene type etc. can be illustrated. Among them, thermoplastic elastomers (SEBS, SEPS, HSBR, SEBR, CEBC) obtained by hydrogenating conjugated diene-based thermoplastic elastomers are preferable.

  The thermoplastic elastomer material is an extremely hygienic material compared to the rubber material. However, depending on the chemical solution used, the liquid contact surface 20 of the elastic plug body 17 may be laminated. For laminating, the same type of resin as the lower frame portion 15 or the container body to be attached is generally used. Thereby, it can be set as the material of the same or similar property in the container which a chemical | medical solution contacts, and the liquid-contacting surface 20 of the elastic plug body 17.

  In addition, the cross-sectional shape of the elastic plug body 17 can be appropriately modified as necessary. Specifically, for example, as shown in FIG. 4A, there is an elastic plug body 41 in which a stepped portion 41c is provided on both the needle stick surface 41a and the liquid contact surface 41b to prevent the dropout. Further, as shown in FIG. 4B, both the needle stick surface 42a and the liquid contact surface 42b may be flat elastic plugs 42. Further, as shown in FIG. 4C, an annular groove 46c having a diameter larger than the diameter of the protrusion 22a of the second upper mold 16 is provided on the needle puncture surface 46a side, and the liquid contact surface 46b is flat. The elastic plug 46 may be configured. Further, as shown in FIG. 4 (d), an annular groove 47c having a diameter larger than the diameter of the protrusion 22a of the second upper mold 16 is provided on the needle puncture surface 47a side, and is prevented from falling off on the liquid contact surface 47b side. The elastic plug body 47 provided with the level | step-difference part 47d for this may be sufficient. Further, as shown in FIG. 4 (e), an elastic plug body 44 is provided with an annular protrusion 44c on the needle puncture surface 44a side and a stepped portion 44d for preventing the dropout on the liquid contact surface 42b side. It may be. Further, as shown in FIG. 4 (f), a stepped portion 45c may be provided only on the needle puncture surface 45a, and the liquid contact surface 45b may be a flat elastic plug 45.

  The method for producing the elastic plug body 17 is not particularly limited, and for example, it can be produced by compression molding or injection molding performed while crushing the thermoplastic elastomer.

(Other matters)
The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the effects of the present invention. For example, in the above-described embodiment, an example has been described in which the inner diameter increases as the lower frame portion approaches the elastic plug body. However, for example, as illustrated in FIG. Below the position, it is also applicable to a port-integrated cap having a lower frame portion 52 having a uniform inner diameter. Moreover, as shown in FIG.5 (b), it is the lower frame part 53 which has a flange, Comprising: It is applicable also to the cap of the type which the container opening part and the flange welded. Furthermore, as shown in FIG.5 (c), it may be an insert type cap that is used by dropping into the container mouth and welding the upper outer periphery thereof. Furthermore, as shown in FIG. 5D, the insert type is the same as the insert type shown in FIG. A cap having an outer frame body formed with the upper frame portion 56 may be used. In this case, the diameter of the elastic plug body 57 is smaller than usual, specifically, within a range of 12 to 24 mm.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to them, but are merely illustrative examples, unless otherwise specified.

Example 1
In this example, the medical cap 60 shown in FIG. 7A was manufactured according to the method shown in FIGS. 1A to 1F described above. LDPE (low density polyethylene, MFR = 1) was used as the material of the outer frame body, and styrene thermoplastic elastomer was used as the material of the elastic plug body 61. As a molding machine, a two-color injection molding machine (trade name; DC100-200) manufactured by Nissei Plastic Industry Co., Ltd. was used.

The molding conditions for the lower frame portion 62 are as follows.
Injection molding temperature: 240 ° C
Injection pressure: 40 kgf / cm ²
Injection time: 3.2 seconds First upper mold temperature and common lower mold temperature: 43 ° C

The molding conditions for the upper frame portion 63 are as follows.
Injection molding temperature: 240 ° C
Injection pressure: 39kgf / cm ²
Injection time: 2.8 seconds Second upper mold temperature and common lower mold temperature: 43 ° C

(Comparative Example 1)
First, the elastic plug body 102 was placed on the pre-formed upper frame portion 101 so that the liquid contact surface faced upward (see FIG. 6A). Next, the upper mold 103 and the lower mold 104 were used to close the mold (see FIG. 6B), and molten resin was injected into the cavity to perform injection molding (FIG. 6C). This manufactured the medical cap 100 which concerns on this comparative example (refer FIG.7 (b)). LDPE (low density polyethylene, MFR = 1) was used as the material of the outer frame body, and styrene thermoplastic elastomer was used as the material of the elastic plug body 102. As a molding machine, a two-color injection molding machine (trade name; DC100-200) manufactured by Nissei Plastic Industry Co., Ltd. was used.

The molding conditions for the upper frame portion 101 are as follows.
Injection molding temperature: 240 ° C
Injection pressure: 42 kgf / cm ²
Injection time: 3.2 seconds First upper mold temperature and common lower mold temperature: 43 ° C

The molding conditions for the lower frame part are as follows.
Injection molding temperature: 240 ° C
Injection pressure: 50 kgf / cm ²
Injection time: 3.4 seconds Second upper mold temperature and common lower mold temperature: 43 ° C

(Puncture test of puncture needle)
Each of the medical caps obtained in Example 1 and Comparative Example 1 was prepared, and the state of the outer frame when the plastic infusion needle was inserted into the elastic stopper was examined. As a result, with respect to the medical cap 60 according to the first embodiment, as shown in FIG. 7A, the elastic plug body 61 is fused and fixed at the upper frame portion 63 and its contact surface, so that the positional displacement occurs. In addition, no voids were formed. On the other hand, in the medical cap according to Comparative Example 1, as shown in FIG. 7B, the contact portion between the upper frame portion 101 and the elastic plug body 102 is not fused. Even if the rib 104 was provided, turning occurred.

(Puncture needle holding force test)
The medical caps obtained in the examples and comparative examples were sterilized at 106 ° C. for 25 minutes using an autoclave. Forty samples of such medical caps were prepared, and the holding force when each of the metal needle (16G metal needle) and the resin needle (400 resin needle) was stabbed into the elastic stopper was examined. Each medical cap was pulled and set in a compression tester, and the following puncture needle attached to the tester was vertically punctured in the center of the elastic stopper, and then the puncture needle was raised at a speed of 200 mm / min. The force (unit: kgf) when the puncture needle was removed from the elastic plug was measured. As the puncture needle, the two kinds of needles were used, and the maximum value, the minimum value, the average value, and the standard deviation were obtained, respectively. The results are shown in Table 1 below.

(Puncture needle leak test)
The medical caps obtained in the examples and comparative examples were sterilized at 106 ° C. for 25 minutes using an autoclave. Next, each medical cap was attached to a test pressure can body, and a connection tube (trade name: TC-00503B) manufactured by Terumo Corporation was punctured at the drip site, and left for 4 hours. Thereafter, the needle was removed and checked for liquid leakage. The number of specimens was 200.

  Next, each medical cap sterilized in the same manner as described above is attached to a test pressure can body, and an infusion set (trade name; TK-A400LK) manufactured by Terumo Corporation is punctured at the drip site and left for 4 hours. did. Thereafter, the needle was removed and checked for liquid leakage. The number of specimens was 200.

  Furthermore, each medical cap sterilized in the same manner as described above was attached to a test pressure can body, and an 18G metal needle was set in a syringe at the mixed injection site, and 10 ml of water was added and punctured vertically. Thereafter, the 18G metal needle was inclined with respect to the needle puncture surface, and water was injected and sucked into the test pressure can body three times. Subsequently, the second 18G metal needle was punctured and the operation of injecting and sucking water was repeated. Furthermore, the amount of liquid leakage after 1 hour was measured. The results are shown in Table 2 below. The number of specimens was 200.

It is sectional drawing for demonstrating the manufacturing method of the medical cap which concerns on one Embodiment of this invention. It is sectional drawing which shows the mode of injection molding of the upper side frame part in the said manufacturing method. It is sectional drawing which shows the various 2nd upper metal mold | die used for the said manufacturing method. It is sectional drawing which shows the various elastic stoppers used for the said medical cap. It is sectional drawing which shows the medical cap which concerns on other embodiment of this invention. 6 is a cross-sectional view for explaining a method for manufacturing the medical cap of Comparative Example 1. FIG. It is sectional drawing which shows the mode of the puncture test of a puncture needle.

DESCRIPTION OF SYMBOLS 11 Common lower metal mold | die 12 Molten resin 13 Upper metal mold | die 14 Mounting part 15 Lower frame part 16 Upper metal mold | die 17 Elastic plug 17a Peripheral part 17b Step part 18 Needle stick surface 19 Nesting 20 Liquid contact surface 22a Protrusion part 22b Level difference Part 23 Projection part 24 Projection part 25 Projection part 26 Projection part 26a Adhering part 27 Outer frame body 28 Cavity 29 Peel film 30 Medical cap 31 Molten resin 32 Upper frame part 41 Elastic plug body 41a Needle stick surface 41b Liquid contact surface 41c Step Portion 42 Elastic stopper 42a Needle stick surface 42b Liquid contact surface 44 Elastic stopper body 44a Needle stick surface 44c Projection 44d Stepped portion 45 Elastic stopper body 45a Needle stick surface 45b Liquid contact surface 45c Step portion 46 Elastic stopper 46a Needle stick Surface 46b Liquid contact surface 46c Annular groove 47 Elastic stopper 47a Needle stick surface 47b Liquid contact surface 47c Annular groove 47d Stepped portion 52 Lower frame portion 53 Side frame 55 the lower frame portion 55a an annular recess 55a the annular recess 56 upper frame section 57 elastic plug body 60 medical cap 61 elastic plug body 62 the lower frame portion 63 upper frame section

Claims (2)

A method for producing a medical cap having an elastic plug body, and an outer frame body having a lower frame portion that holds the peripheral edge portion of the elastic plug body from the lower surface side with the inner wall and an upper frame portion that holds the peripheral edge portion from the upper surface side with the inner wall. And
Using a first upper mold and a common lower mold, a lower frame part having a mounting part on the inner wall on which the elastic plug body can be mounted is molded,
On the mounting portion of the lower frame portion, the elastic plug body is placed with its upper surface facing upward,
A second upper mold having a protrusion having a diameter smaller than the diameter of the elastic plug body and capable of forming a molding cavity of the upper frame when combined with the common lower mold; Using, closing the common lower mold and the mold so that the protruding portion presses the central portion of the elastic plug body and pushes downward,
A method for manufacturing a medical cap, comprising injecting molten resin into the cavity to form an upper frame portion to form the outer frame body. The method for manufacturing a medical cap according to claim 1 , wherein the elastic plug body includes a thermoplastic elastomer.

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