JP2004330775A - Method for producing gas barrier plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a gas barrier plug, which has the following characteristics; 1st: opening and re-sealing are possible and a single color injection molding device can be used, 2nd: a molding time can be shortened and a required amount of molded articles can be produced with using a small number of dies, 3rd: a gas barrier film can stably be fixed to a die, and 4th: no lubricant oil is necessary to be coated after molding and an inexpensive soft resin can be used. <P>SOLUTION: The plug 5 has a gas barrier or water barrier property, comprising a soft resin and a gas barrier film, which is installed with a removable foot part 5b at the mouth position and a cap part 5a for easily moving. The plug is molded by injection molding, and a gas barrier film is inserted between a movable site of a die and a fixed site thereof, and a resin is filled simultaneously from the movable site and the fixed site so as to place the gas barrier film in the inner part of the plug. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a container requiring gas barrier properties, particularly a gas barrier plug for sealing a vacuum blood collection tube.

  2. Description of the Related Art Conventionally, as a plug for sealing a container requiring a cas-barrier such as a vacuum blood collection tube, a plug itself having a gas barrier property has been used. In particular, a plug used for a vacuum blood collection tube is required to have not only a gas barrier property but also a needle that can be pierced at the time of blood collection. As conventional plugs for vacuum blood collection tubes, for example, a plug made of butyl rubber, a plug obtained by bonding a sealing member such as isoprene to an aluminum film (Patent Document 1), a two-color molded plug made of a hard resin and a soft resin. (Patent Document 2), and a plug (Patent Document 3) in which a gas barrier film and a soft resin are combined are disclosed.

JP-A-2-174835 JP-A-10-201742 JP-A-7-255821

However, the conventional plug has the following problems.
In the case of butyl rubber stoppers, it takes 10 to 20 minutes to crosslink the butyl rubber, so that the production efficiency is low. There is a problem that it is necessary to increase the number of devices and the device becomes larger than necessary. Also, in order to insert the plug into the mouth of the container, the plug needs to have a certain degree of lubricity, but butyl rubber has a large coefficient of friction and is inferior in lubricity. It is necessary to apply oil. As described above, the butyl rubber plug has a drawback that it takes a long time to manufacture and inevitably increases the manufacturing cost.

  In the case of a plug body in which a sealing member such as isoprene is bonded to an aluminum film, the aluminum film is sealed by bonding or welding to a container opening such as a polyethylene terephthalate (PET) tube, and the container is sealed. However, once the plug is opened, the plug cannot be resealed. Therefore, when the plug is resealed, there is a disadvantage that a plug for resealing must be separately prepared.

  In the case of a two-color molded plug made of a hard resin and a soft resin, a dedicated molding machine is required to perform two-color molding, but generally a two-color molding machine is expensive, and in addition, a two-color molding machine is a single-color molding. Since the apparatus is larger than the machine, there is a drawback that a larger installation space is required than a single-color molding machine.

  That is, when the two-color molded plug is molded by a two-color molding machine, the cap or the foot of the plug is molded with the primary resin, and then the remaining foot or the cap is molded with the secondary resin. After shaping the primary resin, it is necessary to shape the secondary resin after rotating the mold on which the primary resin is shaped to face the mold for shaping the secondary resin. In other words, it requires twice as many steps as in the case of single-color molding, and the number of batches per batch is halved compared to a normal mold of the same size. Therefore, in order to obtain the required quantity, there is a disadvantage that the number of molds is increased or a large mold is required, and there is also a disadvantage that a special device such as a mold rotating device is required. .

  Furthermore, since a soft resin is generally inferior in gas barrier property to a hard resin, it is necessary to select and use a specific soft resin having an excellent gas barrier property in order to improve the gas barrier property of the obtained plug. In addition, a soft resin having excellent gas barrier properties is expensive, and thus has the disadvantage of increasing the manufacturing cost. Further, if other resins such as inexpensive polyethylene and polypropylene are mixed in order to lower the production cost, the hardness of the obtained plug increases, and it is difficult to pierce the plug with a needle during blood collection.

In the case of a plug obtained by combining a gas barrier film and a soft resin, for example, when a gas barrier film is laminated on the outer surface of a plug made of a soft resin, the outer diameter of the foot of the plug inserted into the container mouth Since the container cannot be sealed and held unless it is larger than the inner diameter of the container mouth, the outer diameter of the foot of the stopper is made slightly larger than the inner diameter of the container mouth, and when the stopper is inserted into the container mouth, Although the feet of the plug are compressed and deformed, the gas barrier film laminated on the outer surface tends to wrinkle when the feet of the plug are compressed and deformed, so that the gas barrier property of the plug is reduced. There were drawbacks.
In the case of a plug in which a gas barrier film is embedded in a soft resin, in order to manufacture the plug in a single step, as shown in FIG. After the gas barrier film 4 is positioned on the foot-side mold 12 for forming the portion so as to be supported by the film supporting portion 12b, the resin is injected and filled into the mold 10 from the resin injection port 11b. The gas barrier film 4 flows from a predetermined position due to the flow (see FIG. 7 (b)), so that the gas barrier film 4 is wrinkled, and it is possible to impart desired gas barrier performance to the obtained plug. There was a disadvantage that it could not be done.

  On the other hand, the above-described plug can be formed twice and the gas barrier film can be embedded in the resin to prevent the occurrence of wrinkles as described above, but the molding time is twice as long. That is, when the plug is formed twice, the mold 15 is separated from the foot-side mold 16, the fixed mold 17, and the cap-side mold 18 as shown in FIGS. 8A to 8F. First, in a state where the gas barrier film 4 is fixed to the fixed mold 17, the fixed mold 17 and the foot-side mold 16 are opposed to each other (FIG. 8A). The resin is filled to form the foot 5b. At this time, the gas barrier film 4 is adhered to the surface of the foot 5b (FIG. 8B). After molding the foot 5b, the foot 5b is taken out of the molding die 16a (FIG. 8 (c)), and the foot-side mold 16 is rotated to face the cap-side mold 18 (FIG. 8 (d)). The foot 5b is inserted again into the molding die 16a (FIG. 8E). Thereafter, the resin is filled into the molding die 18a through the resin injection port 18b, and the molding is performed in a state where the cap 5a is joined to the foot 5b (FIG. 8 (f)). In this way, the plug 5 in which the gas barrier film 4 is embedded between the foot 5b and the cap 5a can be obtained. However, in such a two-part molding, it is necessary to rotate the foot-side mold 16 in the molding process or to remove the foot 5b from the mold and insert it again in the mold. There are drawbacks in that the number of steps increases, the efficiency becomes poor, and the cost of the mold 15 increases because the configuration of the mold 15 is complicated and expensive.

The present invention has been made to solve the conventional problems as described above, the purpose of which is removable in the container mouth, and can be resealed even after opening, In the method for manufacturing a gas barrier plug attached to a container such as a vacuum blood collection tube, for example, even when a soft resin is used to ensure needle penetration required for the plug of the vacuum blood collection tube It is possible to obtain a gas-barrier plug which can impart excellent gas-barrier properties, does not cause wrinkles or the like in the gas-barrier film during use, and does not impair gas-barrier properties. It is an object of the present invention to provide a production method which can obtain a gas-barrier plug using a general single-color injection molding machine without using a special molding machine.
Another object of the present invention is to provide a manufacturing method capable of efficiently obtaining the gas barrier plug as described above.
Still another object of the present invention is to provide a method for producing a gas-barrier plug in which the gas-barrier film can be fixed to a mold in a stable state without causing wrinkles. To provide a manufacturing method that can reliably obtain a plug body,
Still another object of the present invention is that even when a soft resin having poor lubricity is used, there is no need to apply a lubricating oil to the obtained plug body in a later step, that is, detachability to a container, re-installation. An object of the present invention is to provide a manufacturing method capable of efficiently obtaining a gas barrier plug having excellent sealing properties and the like.

In order to achieve the above object, a method for producing a gas barrier plug according to the present invention comprises a soft resin and a gas barrier film, and a detachable foot portion for a container mouth, and a method for sealing a container mouth and attaching and detaching a foot. A method for molding a plug comprising a cap portion for facilitating the injection molding by injection molding, comprising a foot-side mold and a cap-side mold of a mold comprising a foot-side mold and a cap-side mold. The gas barrier film is positioned between the mold, and by simultaneously injecting and filling the soft resin into the mold from the foot side mold and the cap side mold, the gas barrier film is embedded in the soft resin and molded. It is characterized by the following.
In addition, the simultaneous injection and filling of the soft resin into the mold from the foot-side mold and the cap-side mold referred to above means that in the mold, near the barrier film surface, the resin is injected and filled from both molds. Means that the soft resin is filled at such a timing that the soft resins meet.

  As described above, the gas barrier film is positioned between the foot-side mold and the cap-side mold, and the soft resin is injected and filled from both molds to form a plug, thereby forming a gas barrier film in the soft resin. A plug with the film embedded therein can be obtained.

  In the production method of the present invention, the gas barrier film located between the foot-side mold and the shade-side mold may be a continuous gas barrier film that is continuous, and the gas barrier film having the gas barrier property is formed during or after molding. By cutting according to the shape of the plug, a gas barrier plug is obtained. In this case, for example, by making the continuous gas barrier film into a winding type, the continuous gas barrier film can be quickly supplied into the mold, that is, the production of the gas barrier plug is performed continuously and quickly. be able to.

  Further, in the manufacturing method of the present invention, the foot-side mold and the cap-side mold are closed while the gas barrier film is sucked by the suction hole provided in the foot-side mold and / or the cap-side mold of the mold. The gas barrier film may be sandwiched between the two molds, and the gas barrier film may be positioned while being fixed between the two molds. In this case, the gas barrier film can be stably fixed in the mold without causing wrinkles. That is, gas barrier properties can be reliably and stably provided to the obtained gas barrier plug.

  Further, in the production method of the present invention, a lubricating oil may be mixed in advance with the soft resin constituting the gas barrier plug. As a result, even when a resin having a large friction coefficient such as butyl rubber is selected as the soft resin, the lubrication required for the plug body is not applied to the obtained gas barrier plug body without applying a lubricating oil or the like in a later process. Properties can be imparted.

  Since the production method of the present invention has the above-described configuration, it is detachable from the container mouth, and has excellent resealability, and furthermore, easily and reliably provides a gas barrier plug having excellent gas barrier properties. Obtainable. In addition, since the foot portion and the cap portion of the plug can be formed simultaneously, the production time is short and the number of steps is small, so that the production efficiency is very good. Further, since a soft resin is used as the resin constituting the gas barrier plug, not only the gas barrier property is excellent, but also the gas barrier plug having excellent needle piercing properties can be obtained. The sex plug can be suitably used particularly for a vacuum blood collection tube.

  In the production method of the present invention, the gas barrier film to be supplied between the foot-side mold and the shade-side mold is a continuous gas barrier film, so that the gas barrier film can be efficiently supplied into the mold. Therefore, the gas barrier plug can be obtained efficiently. For example, since the continuous gas barrier film can be quickly supplied into the mold by making the continuous gas barrier film a roll-up type, the production of the gas barrier plug can be performed continuously and quickly. . Unnecessary portions of the continuous gas barrier film can be easily cut with a cutting blade or the like according to the shape of the gas barrier plug during or after molding.

  In the manufacturing method of the present invention, when the gas barrier film is located between the foot-side mold and the cap-side mold, the gas-barrier film is sucked from at least one of the foot-side mold and the cap-side mold. By closing the foot-side mold and the cap-side mold, and fixing the gas barrier film between both molds, the gas barrier film can be easily fixed without wrinkles. In addition, the gas barrier film does not shift or wrinkle during molding, and the gas barrier property of the obtained gas barrier plug can be ensured.

  Furthermore, in the production method of the present invention, by blending a lubricating oil in advance in the soft resin constituting the gas barrier plug, even when a resin having poor lubricity is selected as the soft resin, it is obtained. Lubricity required as a plug can be maintained without applying lubricating oil or the like to the gas barrier plug in a later step. That is, a gas-barrier plug excellent in lubricity can be easily obtained with high production efficiency.

Hereinafter, embodiments of the manufacturing method according to the present invention will be described in detail.
As shown in FIG. 1, a mold 1 composed of a cap side mold 2 having a cap mold 2a and a foot mold 3 having a foot mold 3a is used. Is supplied with a gas barrier film 4. Thereafter, the end portion of the gas barrier film 4 is sandwiched between the molds 2 and 3 to fix the gas barrier film 4 in the mold 1, and a soft resin is simultaneously injected and injected from the resin injection ports 2b and 3b. By doing so, the gas barrier plug 5 shown in FIG. 2 can be obtained. 5a is a cap of the gas barrier plug 5, 5b is a foot of the gas barrier plug 5, 5c is a recess provided on the foot, and 5d is a recess provided on the cap. The recess 5c is formed so that when the foot 5b is inserted into the mouth of the container, the foot 5b is compressed and deformed so that the mouth of the container can be sealed. When the plug 5 is used for a vacuum blood collection tube, it is formed to reduce the thickness of the needle piercing portion of the gas barrier plug 5 to improve the needle piercing property.

  Further, the above manufacturing method describes a case where one mold is formed in the mold 1, but as shown in FIG. 4 described later, the number of the gas barrier plugs 5 to be formed by one molding is increased. However, in order to increase the production efficiency, a mold 1 having a plurality of molds may be used. The molding method in this case can be performed in the same manner as described above.

  The method of supplying the gas barrier film 4 into the mold 1 is not particularly limited, and various methods may be adopted. For example, as shown in FIGS. It is supplied continuously between the cap side mold 2 and the foot mold 3, and the continuous gas barrier film 6 is sandwiched between the cap mold 2 and the foot mold 3 simultaneously with or during molding or It is preferable to cut and trim the continuous gas barrier film 6 according to the shape of the gas barrier plug 5 at a desired time after molding.

  At this time, as shown in FIG. 3, an introduction path 2c for introducing the cutting blade into the cap side mold 2 is formed in advance, and the cutting blade is appropriately introduced into the introduction path 2c. Since the cutting and trimming of the continuous gas barrier film 6 can be easily performed simultaneously with the insertion, or during or after the molding, it is not necessary to separately provide a step of cutting the continuous gas barrier film 6 in a subsequent step.

  In addition, as shown in FIG. 4, when using a mold 1 having a plurality of molds, a method of supplying the gas barrier film 4 into the mold 1 includes, for example, a method in which the continuous gas barrier film 6 includes a plurality of molds. The continuous gas barrier film 6 is supplied between the cap-side mold 2 having a mold and the foot mold 3, and when the molds 2 and 3 are closed, the continuous gas barrier film 6 is cut with a cutting blade. A plurality of gas barrier plugs may be formed without cutting the continuous gas barrier film 6, and the continuous gas barrier film 6 may be cut by a cutting blade at an appropriate time during the forming. You may cut it. In addition, the continuous gas barrier film 6 may be cut by a cutting blade when the obtained gas barrier plugs 5 are protruded from the mold 1 after molding without cutting the continuous gas barrier film 6 during molding. Alternatively, after the molding is completed, the continuous gas barrier film 6 may be cut by protruding only the obtained gas barrier plug 5 without using a cutting blade.

  Naturally, as shown in FIG. 5, the gas barrier films 4 punched from the continuous gas barrier film 6 in advance are fixed to the molds in the mold 1, respectively, and the remaining continuous gas barrier film 6 is wound up. For example, cutting and trimming may be performed simultaneously. Reference numeral 6b denotes a winding portion of the continuous gas barrier film 6. In this case, after punching out the gas barrier film 4 from the continuous gas barrier film 6, the unnecessary continuous gas barrier film 6 that has become unnecessary can be wound up. It is also possible to automate such as transferring the punched gas barrier film 4 to a molding die by a robot or the like (see FIG. 5).

Further, when the gas barrier film is positioned between the foot-side mold and the cap-side mold, it is preferable to fix the film so that the position does not shift. For example, as shown in FIG. 6, when the gas barrier film 4 is positioned between the cap side mold 2 and the foot mold 3 and is fixed, suction holes 3 c provided in the foot mold 3 are provided. The gas barrier film 4 is sucked in advance, and the cap side mold 2 and the foot mold 3 are closed to fix the film between both molds. Thereby, the gas barrier film 4 can be reliably fixed in the mold 1, and the gas barrier film 4 can be prevented from flowing due to the flow of the resin and being wrinkled from a predetermined position.
In the above description, the suction hole 3c is provided in the foot-side mold 3, but may be provided in the cap-side mold 2, or may be provided in both molds. Further, in FIG. 6, the gas barrier film 4 is not continuous, but the continuous gas barrier film can be fixed in the same manner.

The soft resin is not particularly limited, and may be appropriately selected according to a desired use or the like. For example, when obtaining a gas-barrier plug for a vacuum blood collection tube, it is preferable to select a soft resin in consideration of needle piercing properties and the like. For example, in addition to elastomers such as olefin-based elastomers and styrene-based elastomers, soft vinyl chloride and the like can be mentioned.
Further, the gas barrier property of the obtained gas barrier plug is mainly provided by a gas barrier film described later, and therefore, the soft resin may be inferior to the gas barrier property. That is, an inexpensive soft resin can be selected, and the manufacturing cost of the gas barrier plug can be reduced.

  It is preferable that a lubricant is previously added to the soft resin as needed. By doing so, even if the soft resin used is inferior in lubricity, after obtaining the gas barrier plug by the above manufacturing method, it is not necessary to further apply a lubricant in a subsequent step, and the A gas-barrier plug that can be easily inserted and detached easily can be obtained with high production efficiency.

  The gas barrier film is not particularly limited as long as it has gas barrier properties and can be integrated with the soft resin. For example, ethylene-vinyl alcohol copolymer (EVOH) and the like And a gas barrier film in which a layer made of an olefin-based elastomer is laminated on both sides of a biaxially stretched film made of Furthermore, for example, in order to further improve the gas barrier properties of the obtained gas barrier plug, a film laminated with aluminum may be used, or using a nanocomposite technique, a gas barrier property film having improved gas barrier properties may be used. You may.

  The thickness of the gas barrier film is not particularly limited, and may be appropriately adjusted. For example, when the obtained gas barrier plug is used for a vacuum blood collection tube, it is preferable that the thickness be such that the needle piercing property is not impaired.

FIG. 4 is a longitudinal sectional view illustrating a state in which a gas barrier film is positioned in a mold in the method for producing a gas barrier plug of the present invention. FIG. 2 is a central longitudinal sectional view showing a plug obtained by the method for producing a gas barrier plug of the present invention. FIG. 4 is a longitudinal sectional view illustrating a method for cutting a continuous gas barrier film in the method for producing a gas barrier plug of the present invention. FIG. 4 is a perspective view illustrating a means for supplying a continuous gas barrier film into a mold in the method for producing a gas barrier plug of the present invention. FIG. 4 is a perspective view illustrating a state in which a gas barrier film punched from a continuous gas barrier film is supplied to a molding die in the method for producing a gas barrier plug of the present invention. FIG. 4 is a longitudinal sectional view illustrating a state in which the gas barrier film is suction-fixed to a mold in the method for producing a gas barrier plug according to the present invention. FIG. 4 is a longitudinal sectional view for explaining a conventional method for manufacturing a plug body in which a gas barrier film and a soft resin are combined. (A) A longitudinal cross-sectional view illustrating a state in which a gas barrier film is positioned in a mold before resin is injected and filled. (B) A longitudinal cross-sectional view illustrating a state in which the gas barrier film flows when the resin is injected and filled in the mold. FIG. 5 is a longitudinal sectional view for explaining a conventional manufacturing method of forming a plug body, which is a combination of a gas barrier film and a soft resin, twice. (A) The longitudinal cross-sectional view explaining the state which located the gas barrier film in the metal mold | die. (B) The longitudinal section explaining the state where the foot of the plug was formed. (C) The longitudinal section explaining the state where the foot of the plug body after molding was taken out. (D) A longitudinal cross-sectional view illustrating a state in which the foot-side mold and the cap-side mold are faced to each other, and a state in which the molded foot is inserted into the foot-side mold again. (E) A longitudinal cross-sectional view illustrating a state where the foot after molding is inserted again into the foot-side mold. (F) A longitudinal sectional view illustrating a state in which the cap is joined to the foot and molded to form a plug.

Explanation of reference numerals

REFERENCE SIGNS LIST 1 mold 2 cap side mold 2a molding die 2b resin injection port 2c introduction path 3 foot side mold 3a molding die 3b resin injection port 3c suction hole 4 gas barrier film 5 gas barrier plug 5a cap section 5b foot 5c, 5d recess 6 continuous gas barrier film 6a punched hole 6b winding section

Claims (4)

  A plug made of a soft resin and a gas barrier film, which can be attached to and detached from the mouth of the container, and a cap that seals the mouth of the container and a cap that makes it easy to attach and detach the feet, by injection molding A gas barrier film is located between the foot-side mold and the cap-side mold of the mold comprising the foot-side mold and the cap-side mold, and the foot-side mold and the cap are provided. A method for producing a gas-barrier plug, wherein a gas-barrier film is embedded in a soft resin and molded by simultaneously injecting and filling a soft resin into a mold from a part side mold.   The gas barrier film located between the foot-side mold and the cap-side mold is a continuous gas barrier film that is continuous, and cuts the continuous gas barrier film during or after molding according to the shape of the gas barrier plug. A method for producing the gas barrier plug according to claim 1.   While sucking the gas barrier film with the suction holes provided in the foot side mold and / or the shade side mold of the mold, the foot side mold and the shade side mold are closed and the gas barrier film is placed between both molds. The method for producing a gas-barrier plug according to claim 1, wherein the gas-barrier film is sandwiched between the molds, and is positioned between the molds. 4. The method for producing a gas barrier plug according to claim 1, wherein a lubricating oil is blended in advance with the soft resin.

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