JP2011073762A - Container formed of resin and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To have a thermoplastic resin having low medicine adsorptivity at a container inner layer of a container body, join the container inner layer and the other layers without using a welding material, have container transparency and low temperature drop impact strength, and keep cleanliness inside a container. <P>SOLUTION: In a medical container, the container inner layer and a container outer layer are welded without using the welding material, the thickness of the container outer layer is formed to be thicker than that of the container inner layer, the container body has a flange 2 formed at a mouth outer circumference, the flange 2 is integrally welded to a stopper body formed of a rubber stopper and an external stopper through a welding assisting part 4 formed of the thermoplastic resin, and the welding assisting part 4 is welded to the outer layer of the container body to keep cleanliness inside the container. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin container having a main body and a plug made of materials having poor adhesion to each other, and a method for manufacturing the same.

  Medical containers are required to have high mechanical properties such as transparency, heat resistance, and barrier properties from the viewpoint of hygiene. Conventionally used resin medical containers include ampoules, vials, syringes, infusion bags, etc., and resins used in these resin medical containers include polyolefins such as polypropylene and polyethylene, and vinyl chloride resins. , Ethylene-vinyl acetate copolymer, and cyclic polyolefin.

  Among these resins, polypropylene is highly hygienic and flexible, and is suitably used for medical containers because it does not generate toxic gas when incinerated and can withstand sterilization. On the other hand, when polypropylene is used for the liquid contact portion with the chemical solution, the polypropylene in contact with the chemical solution adsorbs a specific drug such as a fat-soluble vitamin, which may reduce the concentration of the specific drug during storage.

  Therefore, a cyclic polyolefin known as a material that suppresses adsorption and absorption of a specific drug has been widely used. Further, the cyclic polyolefin is excellent in transparency, heat resistance, hygiene, and the like, and has a high barrier property such as low water vapor permeability, and is very useful as a medical container material.

  However, the cyclic polyolefin has a drawback of poor adhesion to the polyolefin resin. On the other hand, in the medical container, it is not preferable that the component derived from the welding material bleed out, and there is a problem that a commonly used welding material cannot be used.

  Thus, for example, Patent Document 1 describes a technique for bonding HDPE by bringing an L-LDPE having good adhesion to a cyclic polyolefin layer to an intermediate layer.

JP 2008-18063 A

  By the way, as a medical container, the adhesiveness between the plug and the main body is an important factor for hygienic reasons.

  FIG. 10 is a cross-sectional view after welding of a main body and a stopper of a conventional medical container. The container body 220 is welded to the stopper body 205 by the welding surface 207. By the way, for example, if the container body is a cyclic polyolefin and the stopper is made of a polyolefin resin, those resins are overlapped and welded on the welding surface 207. At that time, as described above, since the cyclic polyolefin container has poor adhesion to the polyolefin resin, there is a problem that the adhesion on the welding surface 207 is poor, and the adhesion strength is weak, so that the container is easily peeled off.

  Also, in the case of a low drug multi-layer container by blow molding, since the cyclic polyolefin used in the inner layer of the container body will be exposed on the welding surface, the cyclic polyolefin and the plug material will be welded, There is a problem that the adhesiveness is poor depending on the material of the plug. Hereinafter, it demonstrates, referring drawings.

  FIG. 11 is an enlarged cross-sectional view of the blowing portion of the low drug adsorption container 320 immediately after blow molding. The low drug absorption container 320 has a recessed portion 309 that is partially thinner than the other circumferential thickness as a cutting position for cutting at the same position on the flange portion 302 at all times.

  FIG. 12 is a cross-sectional view of the low drug adsorption container 220 after the blowing part is cut out by the indentation part 309, and FIG. 13 is a schematic diagram showing the positional relationship between the drug adsorption container 220 and the stopper 205. The flange portion 324 becomes thinner as it goes outward in the molding. Therefore, in order to keep the welding surface 271 smooth, it is cut out so as to leave the protruding portion 323. The protruding portion 323 is bent in the inner circumferential direction during welding so as to be in smooth contact with the welding surface 272 of the plug body 205, thereby smoothing the welding surface 271.

  As for the flange part 324 used as the welding surface 271 with the plug body 205, the inner layer 322 will be exposed to the welding surface side with the plug body 205, and an outer layer will come to the facing side. As described above, for low drug adsorption, cyclic polyolefin is often used for the inner layer, and materials having various mechanical properties are used for the outer layer.

  As described above, in the conventional production method by blow molding, the inner layer material of the container body and the plug body must be welded, and the material of the plug body is limited by the material of the inner layer from the viewpoint of adhesiveness. There was a problem. Further, the flange portion 324 could not be created smoothly from the beginning, the smoothness of the weld surface 271 was poor, and the adhesiveness was reduced.

  Therefore, the present invention is for solving the above problems. That is, the object is to satisfactorily weld the container body and the stopper in a resin container.

  The resin container of the present invention is a resin container in which a main body and a plug body are welded and sealed, and the main body has a thick flange portion in an outer peripheral direction, and the flange portion and the plug body are welded. It is provided with a welding auxiliary component made of a thermoplastic resin having good adhesion to the plug body on the outer periphery between the surface, and the plug body is welded by the main body and the welding auxiliary component. And

  The main body is a multi-layer container whose inner layer is made of a thermoplastic resin having a low drug adsorptivity.

  The plug is made of the same resin as the outermost layer of the main body.

  The resin container manufacturing method of the present invention is a resin container manufacturing method in which a main body and a plug body are welded and sealed, and the plug body and a heat having good adhesion to each of a pair of split molds. Holding a welding auxiliary component made of a plastic resin, clamping the injected parison with a split mold and blowing a pressure fluid into the parison, forming a flange portion around the welding auxiliary component, The welding auxiliary part is cut horizontally in the circumferential direction, and the plug is welded and sealed to the cut part.

  According to the present invention, it is possible to satisfactorily weld a container main body and a stopper having poor adhesion to each other.

It is a general-view figure of the resin-made containers which concern on embodiment of this invention. It is a neck enlarged view. It is a general-view figure of the container main body after blow molding. It is an annular part enlarged view. It is sectional drawing after the upper part cut of a container main body. It is sectional drawing which shows the positional relationship of the container main body which concerns on embodiment of this invention, and a stopper. It is a principal part enlarged view of a metal mold | die. It is a schematic diagram of the welding auxiliary component which concerns on embodiment of this invention. It is a figure which shows the multilayer container main body and stopper in other embodiment of this invention. It is a figure which shows the container main body and stopper after the welding in the past. It is a principal part enlarged view of the container main body by the conventional blow molding. It is a principal part enlarged view of the container main body after the blowing part cutting in the past. It is sectional drawing which shows the positional relationship of the container main body and the plug body in the past.

  Hereinafter, the resin container of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a resin container according to an embodiment of the present invention. The resin container includes a container body 20, a welding auxiliary part 4, and a plug body 5. The container body 20 includes a neck portion 1, a trunk portion 12, and a lifting tool portion 13. Note that the present invention is not limited to this shape.

  FIG. 2 is an enlarged view of the neck 1 of the resin container shown in FIG. A welding auxiliary component 4 is provided on the outer periphery of the container body 20 on the welding surface 7 between the stopper 5 and the container body 20. That is, the stopper 5 is in contact with the material of the container body 20 on the inner side at the welding surface 7 and is in contact with the welding auxiliary component 4 on the outer side.

  The welding auxiliary component 4 is made of a material having good adhesion to the plug body 5. For example, a well-known material etc. can be used suitably as a welding material.

  The plug body 5 includes an outer plug 51 and a rubber plug 52. When used as a medical container, since there is drug adsorption not only from the container body but also from the plug, a rubber plug with reduced drug adsorption is preferably used as the rubber plug 52.

  Examples of the rubber plug include a rubber plug made of butyl rubber, elastomer rubber, butadiene, isobrene rubber, fluorine rubber, or the like. In order to reduce drug adsorption, there is a rubber stopper in which a film made of cyclic polyolefin is laminated on the liquid contact surface.

  The thickness of the welding surface 7 in the container main body 20 is thinner than the thickness of the welding surface 7 in the plug body 5, and the flange portion 2 is provided below the welding surface 7. A welding auxiliary component 4 is provided between the flange portion 2 and the welding surface 7.

  Next, a method for molding a resin container in the embodiment of the present invention will be described in detail. The resin container can be made into a thin and complex container by blow molding. In addition, it is not limited to blow molding, The well-known technique which shape | molds a resin container can be used suitably.

  FIG. 3 is a schematic view of the container main body 120 obtained by blow molding. The container main body 120 includes a neck portion 101, a trunk portion 1012, a lifting tool portion 1013, and a welding auxiliary component 104. In addition, the blowing portion 3 is sealed in the neck portion 101 immediately after molding in order to prevent foreign matter and the like from entering the container after molding.

  FIG. 4 is an enlarged cross-sectional view of the neck 101. The neck portion 101 has a flange portion 102. A welding auxiliary component 104 is welded in the direction of the blowing portion 3 of the flange portion 102. The welding assisting part 104 is provided with a recessed part that is partly thinner than the other circumferential thickness as the cutting position 9 for always cutting at the same position. The cut position 9 does not necessarily need to be provided, and it is possible to increase the adhesion area without changing the plug body to a special shape, by reducing the indentation or by not providing it, thereby increasing the welding area with the plug body. Is possible.

Further, the welding auxiliary component 104 can be simultaneously molded together with the flange portion 102 so that the parison covers the welding auxiliary component by injecting the parison after being placed in the split mold and integrally molding by direct blow molding. is there. Further, by providing the welding auxiliary part 104 on the welding surface with the plug body, it becomes possible to easily obtain a desired thickness, and as a result, the cut surface can be used as it is as a welding surface, Smoothness can be maintained. In addition, the flange part 102 may be provided at the time of blow molding, and the welding auxiliary component 104 may be welded in a subsequent process.

  FIG. 5 is a cross-sectional view after the container body 120 is cut out at the cutting position 9. As shown in the drawing, the welding auxiliary part 4 and the container main body 120 are exposed on the welding surface 7 with the stopper.

  FIG. 6 is a schematic diagram showing the positional relationship between the stopper 5 and the container body 20. The rubber stopper 52 has a shape that fits with the inner layer of the container body 20. Further, the outer plug 51 can be sealed by welding the flange portion and the welding surface of the outer plug while the inner layer of the container and the rubber plug 52 are pressed. The rubber stopper 52 and the outer stopper 51 are integrated with each other by fitting the annular groove 62 and the annular protrusion 61. The outer plug is attached so as to cover the rubber plug 52 and has a welding surface 72 with the container body 20. At the time of welding, by fitting the annular protrusions of the outer plug 51 and the rubber plug 52 and pressing the outer plug 51 against the flange portion, the pressing force is concentrated on the line, and the outer plug 51 and the rubber plug 52 can be sealed. I can do it.

  Next, an integral molding method in this embodiment will be described. FIG. 7 is a cross-sectional view of the blow molding die 14. The mold 14 has a positioning pin 10 so that the welding auxiliary component 4 can be positioned and held. The positioning pin 10 is provided at one position perpendicular to the mold parting line. Further, the positioning pin 10 has a tapered shape with a thin tip so that the welding auxiliary component 4 having a positioning hole can be easily inserted and removed. Thereby, it is possible to easily press the welding auxiliary component to the base of the positioning pin 10, and it is possible to completely hold the welding auxiliary component 4 and the unevenness of the cutting position of the mold 14 by fitting. Then, the resin container which has a flange part can be easily produced by injecting parison and blow-molding.

  FIG. 8 is a schematic diagram of the welding auxiliary component 4. (A) shows a top view and (b) shows a front view. As shown in the figure, the welding auxiliary component 4 includes a positioning hole 11 for fitting to the positioning pin 10 on the side surface. The positioning hole 11 has a diameter slightly smaller than the root of the positioning pin 10. Moreover, in order to hold | maintain to each of a pair of division | segmentation metal mold | die, it has a semicircle shape. Moreover, it has the cut position 9 for always excising at the same position.

  FIG. 9 is a schematic diagram showing the multilayer container 200, the plug body 5, and the welding auxiliary part 4 by blow molding according to another embodiment of the present invention. The multilayer container 200 includes an inner layer 21 made of a low drug adsorptive material and an outer layer 22 that supplements the mechanical properties of the inner layer 21.

  In the multilayer container 200, the inner layer 21, the outer layer 22, and the welding auxiliary part 4 are exposed on the welding surface 70 with the plug body 5. With this configuration, since the outer layer 22 and the welding auxiliary component 4 maintain adhesion with the plug body 5, good adhesion can be maintained without being restricted by the material of the inner layer or the material of the plug body 5. At this time, for example, the plug body 5, the welding auxiliary component, and the outer layer 22 can maintain good adhesion by using the same resin.

  As the inner layer 21 of the thermoplastic resin having low drug adsorptivity, it is preferable to use a cyclic polyolefin resin that has a proven track record in drug low adsorptivity with a syringe or the like, has good blow moldability, and is highly transparent. Moreover, since a heat resistance is needed as a medical container, it is preferable that it is glass transition temperature 100 to 180 degreeC. In general, sterilization has a temperature range of 100 to 121 ° C., and particularly around 110 ° C. is used. If the glass transition temperature is 100 ° C. or lower, the resin is expected to melt at the time of sterilization, and if it is 140 ° C. or higher, sterilization is possible. It becomes difficult to form a uniform film, and the moldability of the container deteriorates. Therefore, the glass transition temperature is more preferably 100 ° C to 140 ° C.

  As the outer layer 22, it is preferable to use polypropylene which has a proven record in medical containers that are highly transparent and heat resistant and have a strong drop impact strength.

  In addition, the cyclic polyolefin has a good drug low adsorptivity, but has a hard and brittle material property. Therefore, it is preferable to set it as thin as possible for drainage, drop impact strength and the like. The flange surface has a lower blow ratio than the container body, so each layer is thick. Especially when the inner layer of the container is thick, the material strength difference from the outer layer of the container increases, and the delamination easily occurs. The insert moldability that integrates is deteriorated. Therefore, the membrane ratio of the container inner layer is preferably 10% or less of the entire container body, and more preferably 5% or less in view of the adhesive strength between the container inner layer and the container outer layer.

  Next, the present invention will be described in more detail by way of examples.

  Evaluation is performed in the medical container shown in FIG. 1 that can be filled with 500 mL of water.

(Evaluation methods)
The container body and the stopper are manually pulled and twisted repeatedly to visually check whether peeling occurs.

Example 1
This medical container is manufactured using a multi-layer blow molding machine, and has a two-layer structure in which the innermost container thickness of the thinnest part is about 20 μm and the outer layer thickness is about 180 μm. PP zerath (MFR: 3.7 (230 ° C)) manufactured by Mitsubishi Chemical is used for the outer layer of the container, and ZEONEX manufactured by ZEON (MFR: 17 g / 10 min) for the inner layer of the container. Measurement temperature: 280 ° C, glass transition temperature: 136 (In the Examples and Comparative Examples, the same material is used for the inner layer of the container). The welding auxiliary parts and the plugs were also made of parts based on the same Mitsubishi Chemical PP Zelas. The thickness of the welding auxiliary part is 2 mm.

(Example 2)
It was manufactured in the same manner as in Example 1 except that the thickness of the welding auxiliary part was 3 mm.

(Example 3)
A single-layer container having a thickness of about 200 μm was manufactured using ZEONEX (MFR: 17 g / 10 min, measurement temperature: 280 ° C., glass transition temperature: 136 ° C.) manufactured by Nippon Zeon. Further, a welding auxiliary part was manufactured by LLDPE with a thickness of 3 mm. HDPE was used for the stopper.

(Comparative Example 1)
It was manufactured in the same manner as in Example 1 except that the thickness of the welding auxiliary part was 1 mm.

(Comparative Example 2)
This was manufactured in the same manner as in Example 1 except that the thickness of the welding auxiliary part was 0.5 mm.

(Comparative Example 3)
It was manufactured in the same manner as in Example 2 except that a plug body was manufactured using ZEONEX manufactured by ZEON (MFR: 17 g / 10 minutes, measurement temperature: 280 ° C., glass transition temperature: 136 ° C.).

DESCRIPTION OF SYMBOLS 1 Neck part 2 Flange part 4 Welding auxiliary parts 5 Plug body 7 Welding surface 20 Container body

Claims (4)

In a resin container that welds and seals the main body and stopper,
The main body has a thick flange portion in the outer peripheral direction,
On the outer periphery between the flange portion and the welding surface of the plug body, provided with a welding auxiliary component composed of a thermoplastic resin with good adhesion to the plug body,
The plug body is welded by the main body and the welding auxiliary part.   2. The resin container according to claim 1, wherein the main body is a multi-layer container having an inner layer made of a thermoplastic resin having a low drug adsorptivity.   The resin container according to claim 1 or 2, wherein the stopper is made of the same resin as the outermost layer of the main body. In the manufacturing method of the resin container that welds and seals the main body and the stopper,
Each of the pair of split molds is held with a welding auxiliary component composed of a thermoplastic resin having good adhesiveness with the plug body,
By clamping the injected parison with a split mold and blowing a pressure fluid into the parison, a flange portion is formed around the welding auxiliary part,
Cutting the welding auxiliary part horizontally in the circumferential direction;
A method of manufacturing a resin container, wherein the stopper is welded and sealed to the cut portion.

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